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 Archives
depuis le 01/09/00 |
March 2002 · Volume 35 · Number 3
Liver Biology and Pathobiology
Independent and overlapping transcriptional activation during
liver development and regeneration in mice
Nancy Kelley-Loughnane, Gregg E. Sabla, Catherine Ley-Ebert, Bruce
J. Aronow, Jorge A. Bezerra
Liver development and regeneration share the requirement for
simultaneous proliferation and acquisition of highly specialized
cellular functions. However, little is known about molecules with
regulatory roles in both processes. We hypothesized that transcriptional
reprogramming induced by regeneration recapitulates that of developing
liver. To address this hypothesis, we determined global hepatic
gene expression at embryonic day 14.5, postnatal day 14, and 6
to 24 hours following partial hepatectomy using microarrays containing
8,635 cDNAs. Analysis of genes overexpressed during these conditions
revealed 3 unique expression patterns. The first was predominantly
signature gene clusters specific for each growth phase.
Major groups were hematopoiesis-related genes in embryonic livers,
metabolic genes during postnatal liver development, and growth/inflammation
and metabolic genes during regeneration. The second pattern consisted
of dual overexpression during regeneration and at least one phase
of development. Consistent with potential regulatory roles in
liver growth, most of these transcripts control cell-cell contact,
membrane trafficking, cell growth, metabolism, and inflammatory
response. The third pattern, revealed by surveying their expression
across 76 hepatic and extra-hepatic tissues, uncovered a restricted
temporospatial pattern of liver overexpression for CD14, orosomucoid
1, hepcidin, Spi 2.1, Ith3, and Tim-44. In conclusion, these results
provide a basis for the identification of gene and gene groups
that play critical roles at different phases of liver development
and regeneration, and underscore the importance of maintaining
metabolic demands during organ growth. (HEPATOLOGY 2002;35:525-534.)
A20 protects mice from D-galactosamine/lipopolysaccharide acute
toxic lethal hepatitis
Maria B. Arvelo, Jeffrey T. Cooper, Christopher Longo, Soizic
Daniel, Shane T. Grey, Jerome Mahiou, Eva Czismadia, Graziella
Abu-Jawdeh, Christiane Ferran
Apoptosis of hepatocytes is a seminal feature of fulminant
hepatic failure. We show that the anti-apoptotic protein A20 is
upregulated in hepatocytes by pro-inflammatory stimuli and functions
to protect from apoptosis and limit inflammation by inhibiting
NF-B. Adenoviral mediated hepatic expression of A20 in BALB/c
mice yields an 85% survival rate in the D-galactosamine (D-gal)/lipolysaccharide
(LPS) model of acute toxic hepatitis compared with 15% to 20 %
in control mice. Expression of A20 preserves normal liver function
as assessed by prothrombin time. The protective effect of A20
is independent of tumor necrosis factor (TNF) inhibition. Maintaining
high circulating TNF levels may be advantageous for liver regeneration.
Our data supports this hypothesis as evidenced by increased proliferating
cell nuclear antigen (PCNA) expression in the livers of mice expressing
A20 compared with a dominant negative mutant of the TNF receptor
(TNF-R), 6 hours following D-gal/LPS administration. In conclusion,
these results qualify A20 as part of a physiologic, protective
response of hepatocytes to injury and a promising gene therapy
candidate for clinical applications aimed at preventing and treating
viral and toxic fulminant hepatic failure. (HEPATOLOGY 2002;35:535-543.)
Role of mitochondrial permeability transition in diclofenac-induced
hepatocyte injury in rats
Yasuhiro Masubuchi, Shintaro Nakayama, Toshiharu Horie
Hepatotoxicity of diclofenac has been known in experimental
animals and humans but its mechanism has not been fully understood.
The present study examined the role of mitochondrial permeability
transition (MPT) in the pathogenesis of diclofenac-induced hepatocyte
injury by using isolated mitochondria and primary culture hepatocytes
from rats. Incubation of energized mitochondria with succinate
in the presence of Ca2+ and diclofenac resulted in mitochondrial
swelling, leakage of accumulated Ca2+, membrane depolarization,
and oxidation of nicotinamide adenine dinucleotide phosphate and
protein thiol. All of these phenomena were suppressed by coincubation
of the mitochondria with cyclosporin A, a typical inhibitor of
MPT, showing that diclofenac opened the MPT pore. It was also
suggested that reactive oxygen species probably generated during
mitochondrial respiration and/or voltage-dependent mechanism was
involved in MPT, which are proposed as mechanisms of MPT by uncouplers
of mitochondrial oxidative phosphorylation. Culture of hepatocytes
for 24 hours with diclofenac caused a decrease in cellular ATP,
leakage of lactate dehydrogenase and membrane depolarization.
The hepatocyte toxicity thus observed was attenuated by coincubation
of the hepatocytes with cyclosporin A and verapamil, a Ca2+ channel
blocker. In conclusion, these results showed the important role
of MPT in pathogenesis of hepatocyte injury induced by diclofenac
and its possible contribution to human idiosyncratic hepatotoxicity.
(HEPATOLOGY 2002;35:544-551.)
COX-2 inhibits Fas-mediated apoptosis in cholangiocarcinoma
cells
Ugochukwu C. Nzeako, Maria Eugenia Guicciardi, Jung-Hwan Yoon,
Steven F. Bronk, Gregory J. Gores
Fas expression has been shown to negatively regulate the progression
of cholangiocarcinoma cells in xenografts. However, many human
cholangiocarcinomas express Fas, suggesting these cancers have
developed mechanisms to inhibit Fas-mediated apoptosis. Cyclooxygenase-2
(COX-2), which generates prostanoids, is expressed by many cholangiocarcinomas.
Therefore, our aim was to determine whether COX-2 expression inhibits
death receptormediated apoptosis in KMBC cells, a cholangiocarcinoma
cell line. These cells express messenger RNA for the death receptors
Fas, tumor necrosis factor receptor 1 (TNF-R1), death receptor
4 (DR4), and DR5. Agonists for these death receptors, CH-11, TNF-,
and TRAIL all induced apoptosis. However, COX-2, whether induced
by proinflammatory cytokines or transient transfection, only significantly
inhibited Fas-mediated apoptosis. The COX-2 inhibitor NS-398 restored
Fas-mediated apoptosis in COX-2 transfected cells. Prostaglandin
E2 reduced apoptosis and mitochondrial depolarization after treatment
with the Fas agonist CH-11. Of a variety of antiapoptotic proteins
examined, COX-2/prostaglandin E2 only increased expression of
Mcl-1, an antiapoptotic member of the Bcl-2 family. In conclusion,
these data suggest that prostanoid generation by COX-2 specifically
inhibits Fas-mediated apoptosis, likely by up-regulating Mcl-1
expression. Pharmacologic inhibition of COX-2 may be useful in
augmenting Fas-mediated apoptosis of cholangiocarcinoma cells.
(HEPATOLOGY 2002;35:552-559.)
Cold-induced apoptosis of rat liver cells in University of
Wisconsin solution: The central role of chelatable iron
Uta Kerkweg, Tongju Li, Herbert de Groot, Ursula Rauen
Although University of Wisconsin (UW) solution aims at the
prevention of cold-induced cell injury, it failed to protect against
cold-induced apoptosis of hepatocytes and liver endothelial cells:
when incubated in UW solution at 4°C for 24 hours and subsequently
rewarmed at 37°C, 72% ± 8% of rat hepatocytes and 81%
± 5% of liver endothelial cells lost viability. In both
cell types, the observed cell damage occurred under an apoptotic
morphology; it appeared to be mediated by a rapid increase in
the cellular chelatable iron pool by a factor 2 (as determined
in hepatocytes) and subsequent formation of reactive oxygen species
(ROS). Consequently, this cell injury was decreased by iron chelators
to 6 to 25% (hepatocytes) and 4% ± 2% (liver endothelial
cells). Deferoxamine nearly completely inhibited the occurrence
of apoptotic morphology in both cell types. In liver endothelial
cells, cold-induced apoptosis occurring during rewarming after
24 hours of cold incubation in UW solution was far more pronounced
than in cell culture medium (loss of viability: 81% ± 5%
vs. 28% ± 13%), but viability could even be maintained
for 2 weeks of cold incubation by use of deferoxamine. In conclusion,
this pathological mechanism might be an explanation for the strong
endothelial cell injury known to occur after cold preservation.
With regard to the extent of this iron-mediated injury, addition
of a suitable iron chelator to UW solution might markedly improve
the outcome of liver preservation. (HEPATOLOGY 2002;35:560-567.)
Differentiation-dependent and subset-specific recruitment of
T-helper cells into murine liver
Katja Klugewitz, Stefan Andreas Topp, Uta Dahmen, Toralf Kaiser,
Sabine Sommer, Evelyn Kury, Alf Hamann
It has been suggested that the liver traps and deletes activated
and potentially harmful T cells, especially of the CD8+ subset,
providing mechanisms to limit systemic immune responses. It is
unknown whether this also applies to CD4+ T cells. In this study,
we show that activated stages of CD4+ T cells were trapped in
the liver on intraportal injection. Intravital microscopy showed
an immediate adhesion of activated CD4+ T cells within periportal
sinusoids after intraportal injection. Furthermore, we detected
high frequencies of interferon gamma (IFN-) (Th1) and interleukin
4 (IL-4) (Th2) synthesizing effector cells in the liver.
Transfer experiments were performed to identify those phenotypes
showing specific retention in the liver. Our data show that effector
stages and activated cells in general are more efficiently recruited
into the liver than resting CD4+ T cells, similar to what has
previously been shown for CD45RBlow memory cells. In addition,
we observed a certain preference for Th1-polarized cells to be
trapped by the liver. However, the actual cytokine-producing cells
did not specifically enrich among the total population. In conclusion,
these data indicate that the liver acts as a filter for activated
and memory/effector cells. Cells trapped in the liver might subsequently
undergo modulatory influences exerted by the postulated specific
microenvironment of the liver. (HEPATOLOGY 2002;35:568-578.)
The cyclooxygenase system participates in functional mdr1b
overexpression in primary rat hepatocyte cultures
Christina Ziemann, Dirk Schäfer, Gudrun Rüdell, Georg
F. Kahl, Karen I. Hirsch-Ernst
Overexpression of mdr1-type P-glycoproteins (P-gps) is thought
to contribute to primary chemotherapy resistance of untreated
hepatocellular carcinoma. However, mechanisms of endogenous multidrug
resistance 1 (mdr1) gene activation still remain unclear.
Because recent studies have demonstrated overexpression of cyclooxygenase-2
(COX-2) in hepatocytes during early stages of hepatocarcinogenesis,
we investigated whether the COX system, which catalyzes the rate-limiting
step in prostaglandin synthesis, participates in mdr1 gene
regulation. In the present study, primary rat hepatocyte cultures,
exhibiting time-dependent mdr1b overexpression, demonstrated basal
COX-2 and COX-1 mRNA expression and liberation of prostaglandin
E2 (PGE2), indicative of an active COX-dependent arachidonic acid
metabolism. PGE2 accumulation in culture supernatants was further
enhanced by arachidonic acid (1µmol/L) and epidermal growth
factor (EGF) (16 nmol/L). PGE2 and prostaglandin F2 (PGF2) (3-6µg/mL),
added directly to the culture medium, significantly up-regulated
intrinsic mdr1b mRNA overexpression and mdr1-dependent transport
activity. Up-regulation was maximal after 3 days of culture. Like
prostaglandins, the COX substrate, arachidonic acid, also induced
mdr1b gene expression. Apart from this, structurally different
COX inhibitors (indomethacin, meloxicam, NS-398) mediated significant
inhibition of time-dependent and EGF-induced mdr1b mRNA overexpression,
resulting in enhanced intracellular accumulation of the mdr1 substrate,
rhodamine 123 (Rho123). Thus, the present data support the conclusion
that the release of prostaglandins through activation of the COX
system participates in endogenous mdr1b gene regulation.
COX-2 inhibition might constitute a new strategy to counteract
primary mdr1-dependent chemotherapy resistance. (HEPATOLOGY 2002;35:579-588.)
Farnesoid X receptor and bile salts are involved in transcriptional
regulation of the gene encoding the human bile salt export pump
(*Human Study*)
Jacqueline R. M. Plass, Olaf Mol, Janette Heegsma, Mariska Geuken,
Klaas Nico Faber, Peter L. M. Jansen, Michael Müller
The bile salt export pump (BSEP or ABCB11) mediates the adenosine
triphosphatedependent transport of bile salts across the
canalicular membrane of the hepatocyte. Mutations in the corresponding
ABCB11 gene cause progressive familial intrahepatic cholestasis
type 2. The aim of this study was to investigate the regulation
of human ABCB11 gene transcription by bile salts. First,
a 1.7-kilobase human ABCB11 promoter region was cloned.
Sequence analysis for possible regulatory elements showed a farnesoid
X receptor responsive element (FXRE) at position 180. The
farnesoid X receptor (FXR) functions as a heterodimer with the
retinoid X receptor (RXR) and can be activated by the bile salt
chenodeoxycholic acid (CDCA). Luciferase reporter gene assays
showed that the ABCB11 promoter is positively controlled
by FXR, RXR, and bile salts in a concentration-dependent manner.
Mutation of the FXRE strongly represses the FXR-dependent induction.
Second, endogenous ABCB11 transcription regulation was
studied in HepG2 cells, stably expressing the rat sodium-dependent
taurocholate transporter (rNtcp) cells. ABCB11 expression
was induced by adding bile salts to the culture medium, and this
effect was maximized by combining it with cotransfection of rFxr
and hRXR. Reducing endogenous FXR levels using RNA interference
fully repressed the bile saltinduced ABCB11 expression.
In conclusion, these results show that FXR is required for the
bile saltdependent transcriptional control of the human ABCB11
gene and that the cellular amount of FXR is critical for the level
of activation of ABCB11 transcription. (HEPATOLOGY 2002;35:589-596.)
Dissolution of cholesterol gallstones in mice by the oral administration
of a fatty acid bile acid conjugate
Tuvia Gilat, Alicia Leikin-Frenkel, Ilana Goldiner, Zamir Halpern,
Fred M. Konikoff
Gallstones, mostly cholesterol stones, affect some 15% of the
population. Oral bile salts dissolve human cholesterol gallstones,
but with low efficacy, and surgery remains the main therapeutic
option. Fatty acid bile acid conjugates (FABACs) were shown to
prevent formation of cholesterol gallstones in experimental animals.
The aim of this study was to test whether these compounds could
dissolve preexisting cholesterol gallstones via oral administration.
Inbred, gallstone-susceptible C57J/L mice were given a lithogenic
diet for 2 months, and the presence of gallstones was ascertained.
The mice were then switched to a regular diet while part of them
were given in addition C20-FABAC, by gavage, at a dose of 0.5
or 3 mg per animal per day. All mice tested had cholesterol gallstones
after 2 months on the lithogenic diet. In study I, after 2 months
on the regular diet, 3 of 4 (75%) of the controls had gallstones,
whereas none of the 6 FABAC-fed animals (3 mg/d) had stones (P
= .033). In study II, evaluating 2 FABAC doses, after 2 months
on the regular diet, 8 of 8 (100%) of the controls had gallstones,
which were found in 2 of 7 (28%) and 1 of 8 (12%) of the mice
supplemented with 0.5 mg/d (P = .007) or 3 mg/d (P
= .001) FABAC, respectively. On a molar basis, the dose of 0.5
mg FABAC is equivalent to 14 mg/kg/d of a bile acid. In conclusion,
FABACs given orally can dissolve preexisting cholesterol gallstones
in mice. This was accomplished with a dose of FABAC equivalent
to the dose of bile acids used in human gallstone dissolution.
(HEPATOLOGY 2002;35:597-600.)
Liver Failure and Liver Disease
Change in portal flow after liver transplantation: Effect
on hepatic arterial resistance indices and role of spleen size
(*Human Study*)
Massimo Bolognesi, David Sacerdoti, Giancarlo Bombonato, Carlo
Merkel, Giovanni Sartori, Roberto Merenda, Valeria Nava, Paolo
Angeli, Paolo Feltracco, Angelo Gatta
Information on changes in splanchnic hemodynamics after liver
transplantation is incomplete. In particular, data on long-term
changes are lacking, and the relationship between changes in arterial
and portal parameters is still under debate. The effect of liver
transplantation on splanchnic hemodynamics was analyzed with echo-Doppler
in 41 patients with cirrhosis who were followed for up to 4 years.
Doppler parameters were also evaluated in 7 patients transplanted
for acute liver failure and in 35 controls. In cirrhotics, portal
blood velocity and flow increased immediately after transplantation
(from 9.1 ± 3.7 cm/sec to 38.3 ± 14.6 and from 808
± 479 mL/min to 2,817 ± 1,153, respectively, P
< .001). Hepatic arterial resistance index (pulsatility index)
also augmented (from 1.36 ± 0.32 to 2.34 ± 1.29,
P < .001) and was correlated with portal blood velocity
and flow. The early changes in these parameters were related,
in agreement with the hepatic buffer response theory. Portal flow
returned to normal values after 2 years. Superior mesenteric artery
flow normalized after 3 to 6 months. Splenomegaly persisted after
4 years, when spleen size was related to portal blood flow. In
7 patients transplanted for acute liver failure, portal flow,
and hepatic arterial resistance index were normal after transplantation.
In conclusion, a high portal flow was present in cirrhotics until
2 years after transplantation, probably because of maintenance
of elevated splenic flow. An early increase in hepatic arterial
resistance indices is a common finding, but it is transient and
is related to the increase in portal blood flow. A normal time
course of portal-hepatic hemodynamics was detected in patients
transplanted for acute liver failure. (HEPATOLOGY 2002;35:601-608.)
Endoscopic treatment versus endoscopic plus pharmacologic treatment
for acute variceal bleeding: A meta-analysis (*Human Study*)
Rafael Bañares, Agustín Albillos, Diego Rincón,
Sonia Alonso, Mónica González, Luis Ruiz-del-Arbol,
Magdalena Salcedo, Luis-Miguel Molinero
Endoscopic therapy, involving either injection sclerosis or
band ligation, is considered the intervention of first choice
for acute variceal bleeding (AVB). Pharmacologic agents have also
been shown to be highly effective in the control of the bleeding
episode. The purpose of this meta-analysis was to assess whether
vasoactive drugs may improve the efficacy of endoscopic therapy
(injection sclerosis or band ligation) in the control of AVB and
thus increase survival rates. Computer databases and scientific
meeting abstracts from 1994 to 2001 were used to search for randomized
trials that compared the combined use of endoscopic and drug therapy
with endoscopic therapy alone in the control of AVB. Eight trials
involving 939 patients fulfilled the selection criteria and the
following evaluated by standard meta-analysis methods: initial
hemostasis, 5-day hemostasis, 5-day mortality, and adverse events.
Combined treatment improved initial control of bleeding (relative
risk [RR], 1.12; 95% confidence interval (CI), 1.02-1.23), and
5-day hemostasis (RR, 1.28; 95% CI, 1.18-1.39), with numbers of
patients needed to treat (NNT) of 8 and 5, respectively. The difference
in favor of combined treatment remained significant when trials
that used drugs other than octreotide or that included a low proportion
of alcoholic patients (<40%) or high-risk cirrhotic patients
(<35%) were excluded. Mortality was not significantly decreased
by combined therapy (RR, 0.73; 95% CI, 0.45-1.18). Severe adverse
events were similar in both groups. In conclusion, in patients
with AVB, pharmacologic agents improve the efficacy of endoscopic
therapy to achieve initial control of bleeding and 5-day hemostasis,
yet fail to affect mortality. (HEPATOLOGY 2002;35:609-615.)
Recombinant factor VIIa improves clot formation but not fibrinolytic
potential in patients with cirrhosis and during liver transplantation
(*Human Study*)
Ton Lisman, Frank W. G. Leebeek, Karina Meijer, Jan Van Der Meer,
H. Karel Nieuwenhuis, Philip G. De Groot
Cirrhosis is associated with a bleeding tendency, which is
particularly pronounced during orthotopic liver transplantation
(OLT). A novel approach to treating the bleeding diathesis of
patients with cirrhosis is administration of recombinant factor
VIIa (rFVIIa). This study examined whether the efficacy of rFVIIa
in cirrhosis might be explained in part by enhanced down-regulation
of fibrinolysis by thrombin-activatable fibrinolysis inhibitor
(TAFI). Addition of therapeutic or supratherapeutic doses of rFVIIa
to plasma of 12 patients with stable cirrhosis did not result
in a prolongation of clot lysis time, though clotting times were
significantly reduced. Also, clot lysis assays of plasma samples
taken during and after OLT, which was performed with or without
a single bolus dose of rFVIIa, did not show any effect of rFVIIa
on plasma fibrinolytic potential. In conclusion, this study shows
no evidence for an antifibrinolytic effect of rFVIIa in cirrhotic
patients or in patients undergoing OLT. (HEPATOLOGY 2002;35:616-621.)
Intestinal mucosal alterations in experimental cirrhosis in
the rat: Role of oxygen free radicals
Anup Ramachandran, Ramamoorthy Prabhu, Simmy Thomas, Jayasree
Basivi Reddy, Anna Pulimood, Kunissery A. Balasubramanian
Cirrhosis is associated with altered gastrointestinal function,
and bacterial translocation from the gut plays an important role
in the etiology of spontaneous bacterial peritonitis (SBP) seen
in this condition. Although alterations in gut motility and intestinal
permeability are recognized in cirrhosis, the intestinal damage
at the cellular and subcellular levels is not well understood.
This study looked at the mucosal alterations in experimental cirrhosis
and the role of oxygen free radicals in this process. It was shown
that cirrhosis results in oxidative stress in the intestine, as
seen by increased xanthine oxidase (XO) activity and altered antioxidant
status. Cirrhosis also affects enterocyte mitochondrial function,
as assessed by respiratory control ratio, swelling, and calcium
flux. Increased lipid peroxidation of the brush border membranes
(BBMs) was seen along with altered intestinal transport. In conclusion,
this study shows that intestinal mucosal alterations are seen
in experimental cirrhosis and are possibly mediated by oxidative
stress. (HEPATOLOGY 2002;35:622-629.)
Hepatic arterial buffer response in patients with advanced
cirrhosis (*Human Study*)
Veit Gülberg, Klaus Haag, Martin Rössle, Alexander L.
Gerbes
Hepatic arterial buffer response (HABR) is considered an important
compensatory mechanism to maintain perfusion of the liver by hepatic
arterial vasodilation on reduction of portal venous perfusion.
HABR has been suggested to be impaired in patients with advanced
cirrhosis. In patients with hepatopetal portal flow, placement
of a transjugular intrahepatic portosystemic shunt (TIPS) reduces
portal venous liver perfusion. Accordingly, patients with severe
cirrhosis should have impaired HABR after TIPS implantation. Therefore,
the aim of this study was to investigate the effect of TIPS on
HABR as reflected by changes in resistance index (RI) of the hepatic
artery. A total of 366 patients with cirrhosis (Child-Pugh class
A, 106; class B, 168; class C, 92) underwent duplex Doppler ultrasonographic
examination with determination of RI and maximal flow velocity
in the portal vein before and 1 month after TIPS placement. Portosystemic
pressure gradient was determined before and after TIPS placement.
In 29 patients with hepatofugal portal blood flow, RI was significantly
lower than in 337 patients with hepatopetal flow (0.63 ±
0.02 vs. 0.69 ± 0.01; P < .001). TIPS induced
a significant decrease of the RI in patients with hepatopetal
flow (RI, 0.69 ± 0.01 before vs. 0.64 ± 0.01 after
TIPS; P = .001) but not in patients with hepatofugal flow
(RI, 0.63 ± 0.02 before vs. 0.63 ± 0.02 after TIPS;
NS). This response was not dependent on the Child-Pugh class.
In conclusion, our results suggest that some degree of HABR is
preserved even in patients with advanced cirrhosis with significant
portal hypertension. (HEPATOLOGY 2002;35:630-634.)
Risk factors of fibrosis in alcohol-induced liver disease (*Human
Study*)
Bruno Raynard, Axel Balian, David Fallik, Frédérique
Capron, Pierre Bedossa, Jean-Claud Chaput, Sylvie Naveau
In patients with nonalcoholic steatohepatitis (NASH), age,
obesity, and diabetes mellitus are independent predictors of the
degree of fibrosis. The relative risk for fibrosis adjusted for
sex was also associated with increasing grade of Perls stain.
The aim of this study was to determine whether the risk factors
for fibrosis described in NASH are also risk factors in alcohol-induced
liver disease. A total of 268 alcoholic patients with negative
hepatitis B virus and hepatitis C virus serology underwent liver
biopsy. Fibrosis was assessed semiquantitatively by a score fluctuating
between 0 to 8. Liver iron overload was assessed by Perls staining
and graded in 4 classes. We have used multivariate regression
with partial correlation analysis to assess the variability of
fibrosis score according to the value of 7 variables: sex, age,
body mass index (BMI) in the past year before the hospitalization
when the patient was asymptomatic, daily alcohol intake over the
past 5 years, total duration of alcohol abuse, Perls grade, and
blood glucose level. In the multivariate regression, fibrosis
score was positively correlated with age (P = .001), BMI
(P = .002), female sex (P < .05), Perls grade
(P < .05), and blood glucose level (P < .05).
Twenty percent of the variability of fibrosis score was explained
by the 7 variables. In conclusion, after adjustment for daily
alcohol intake and total duration of alcohol abuse, BMI, Perls
grade, and blood glucose are also independent risk factors for
fibrosis in alcohol-induced liver disease, raising therapeutic
implications for the management of these patients. (HEPATOLOGY
2002;35:635-638.)
Histologic and biochemical changes during the evolution of
chronic rejection of liver allografts (*Human Study*)
Desley A. H. Neil, Stefan G. Hubscher
Criteria for histologic diagnosis of chronic rejection (CR)
are based on changes seen late in the disease process that are
likely to be irreversible and unresponsive to treatment. Changes
occurring during the evolution of CR are less clearly defined.
The serial biopsy specimens, failed allografts, and biochemical
profiles of 28 patients who underwent retransplantation for CR
were examined with the aim of identifying histologic and biochemical
features that were present during the early stages of CR. For
each case, a point of acute deterioration in liver function tests
(LFTs) was identified ("start time" [ST]) that subsequently
progressed to graft failure. Biopsy specimens before, at the time
of ("start biopsy" [SB]), and after the ST were assessed
histologically, and findings were correlated with the biochemical
changes. CR resulted from acute rejection (AR) that did not resolve.
Centrilobular necroinflammation (CLNI) associated with an elevated
aspartate transaminase (AST) level and portal tract features of
AR were present at the start. Portal AR features resolved, CLNI
persisted, AST level remained elevated, and bilirubin and alkaline
phosphatase levels progressively increased throughout the evolution
of CR. Portal tracts also showed a loss of small arterial and
bile duct branches, with arterial loss occurring early and bile
duct loss as a later progressive lesion. Foam cell arteriopathy
was rarely seen in needle biopsy specimens. In conclusion, findings
from this study may help identify patients at risk of progressing
to graft loss from CR at a stage when the disease process is potentially
reversible and amenable to treatment. (HEPATOLOGY 2002;35:639-651.)
Time-dependent Cox regression model is superior in prediction
of prognosis in primary sclerosing cholangitis (*Human Study*)
Kirsten Muri Boberg, Giuseppe Rocca, Thore Egeland, Annika Bergquist,
Ulrika Broomé, Llorenc Caballeria, Roger Chapman, Rolf
Hultcrantz, Stephen Mitchell, Albert Pares, Floriano Rosina, Erik
Schrumpf
More precise prognostic models are needed for prediction of
survival in patients with primary sclerosing cholangitis (PSC),
particularly for the selection of candidates for liver transplantation.
The aim of this study was to develop a time-dependent prognostic
model for the calculation of updated short-term survival probability
in PSC. Consecutive clinical and laboratory follow-up data from
the time of diagnosis were collected from the files of 330 PSC
patients from 5 European centers, followed for a median of 8.4
years since diagnosis. Time-fixed and time-dependent Cox regression
analyses, as well as the additive regression model, were applied.
The reliability of the models was tested by a cross-validation
procedure. Bilirubin (on a logarithmic scale), albumin, and age
at diagnosis of PSC were identified as independent prognostic
factors in multivariate analysis of both the time-fixed and the
time-dependent Cox regression models. The importance of bilirubin
was more pronounced in the time-dependent model (hazard ratio
[HR], 2.84) than in the time-fixed analysis (hazard ratio, 1.51).
The additive regression model indicated that once the patients
survive beyond the first 5 years, the impact on prognosis of albumin
at diagnosis ceases. The time-dependent prognostic model was superior
to the time-fixed variant in assigning low 1-year survival probabilities
to patients that actually survived less than 1 year. In conclusion,
a time-dependent Cox regression model has the potential to estimate
a more precise short-term prognosis in PSC compared with the traditional
time-fixed models. (HEPATOLOGY 2002;35:652-657.)
Antibodies to conformational epitopes of soluble liver antigen
define a severe form of autoimmune liver disease (*Human Study*)
Yun Ma, Manabu Okamoto, Mark G. Thomas, Dimitrios P. Bogdanos,
Agnel R. Lopes, Bernard Portmann, James Underhill, Ralf Dürr,
Giorgina Mieli-Vergani, Diego Vergani
Prevalence and clinical relevance of antibodies to soluble
liver antigen (tRNP(Ser)Sec/SLA) in autoimmune hepatitis (AIH)
have been investigated using partially purified or prokaryotically
expressed antigen. The aim of this study was to improve the detection
of anti-tRNP(Ser)Sec/SLA by establishing an immunoassay that was
able to identify antibodies directed to conformational epitopes
and to investigate the clinical implication of this autoantibody
in autoimmune liver disease. By using eukaryotically expressed
tRNP(Ser)Sec/SLA as target in a radioligand assay (RLA), 81 patients
with autoimmune liver disease (AILD) (33 type 1 AIH, 31 type 2
AIH, and 17 autoimmune sclerosing cholantitis [ASC]), 147 pathologic,
and 56 healthy controls were investigated. RLA results were compared
with those obtained using a commercial enzyme-linked immunosorbent
assay (ELISA) and immunoblot. Reactivity to tRNP(Ser)Sec/SLA was
present in 58% of patients with type 1 and type 2 AIH, 41% with
ASC, but in only 3 pathologic controls. RLA was similarly disease-specific
but remarkably more sensitive than ELISA and immunoblot. A prospective
study showed that anti-tRNP(Ser)Sec/SLApositive patients
run a severe clinical course, having worse histology, needing
longer to achieve remission, relapsing and requiring liver transplantation
or dying more frequently than anti-tRNP(Ser)Sec/SLA negative patients.
Anti-tRNP(Ser)Sec/SLA production was favored by the possession
of DR3 and A1-B8-DR3 in AIH type 1 and ASC, and prevented by the
possession of A2 in all 3 types of AILD, particularly in type
2 AIH. In conclusion, anticonformational tRNP(Ser)Sec/SLA reactivity
is frequent in type 1 and type 2 AIH and ASC, defining patients
with a worse prognosis. (HEPATOLOGY 2002;35:658-664.)
Viral Hepatitis
Varied assembly and RNA editing efficiencies between genotypes
I and II hepatitis D virus and their implications (*Human Study*)
Sheng-Chieh Hsu, Wan-Jr Syu, I-Jane Sheen, Hui-Ting Liu, King-Song
Jeng, Jaw-Ching Wu
The mechanisms that link genotypes of hepatitis D virus (HDV)
with clinical outcomes have not yet been elucidated. Genotypic
variations are unevenly distributed along the sequences of hepatitis
delta antigens (HDAgs). Of these variations, the packaging signal
at the C-terminus has a divergence of 74% between genotypes I
and II. In this report, we address the issue of whether these
high variations between genotypes affect assembly efficiency of
HDV particles and editing efficiency of RNA. Viral package systems
of transfection with expression plasmids of hepatitis B surface
antigen and HDAgs or whole genomes of HDV consistently indicate
that the package efficiency of genotype I HDV is higher than that
of genotype II. Segment swapping of large-form HDAg indicates
that the C-terminal 19-residue region plays a key role for the
varied assembly efficiencies. Also, the editing efficiency of
genotype I HDV is higher than that of genotype II. The nucleotide
and structural changes surrounding the editing site may explain
why genotype II HDV has a low RNA editing efficiency. The findings
of in vitro assembly systems were further supported by
the observations that patients infected with genotype II had significantly
lower alanine transaminase (ALT) levels, more favorable outcomes
(P < .05), and a trend to have lower serum HDV RNA levels
as compared with those infected with genotype I HDV (P
= .094). In conclusion, genotype II HDV secretes fewer viral particles
than genotype I HDV does, which in turn may reduce the extent
of infection of hepatocytes and result in less severe hepatic
inflammation. (HEPATOLOGY 2002;35:665-672.)
Clinical evaluation (phase I) of a combination of two human
monoclonal antibodies to HBV: Safety and antiviral properties
(*Human Study*)
Eithan Galun, Rachel Eren, Rifaat Safadi, Yaffa Ashour, Norah
Terrault, Emmet B. Keeffe, Edith Matot, Sara Mizrachi, Dov Terkieltaub,
Merav Zohar, Ido Lubin, Judith Gopher, Daniel Shouval, Shlomo
Dagan
Treatment of chronic hepatitis B virus (HBV) infection with
interferon alfa and lamivudine is characterized by lack of viral
clearance, loss of response, or emergence of drug-resistant mutants.
Thus, new and multiple drug approaches are needed. We have developed
two fully human monoclonal antibodies, directed against different
epitopes of hepatitis B surface antigen (HBsAg) that bind to all
major HBV subtypes. A phase I clinical study was conducted to
evaluate the safety, tolerability, and efficacy of a mixture of
these two monoclonal antibodies, HBV-ABXTL. A total of 27 chronic
HBV patients were enrolled. In part A of the study 15 patients
in 5 cohorts received a single intravenous infusion of antibodies
with doses ranging from 0.26 mg (260 IU) to 40 mg (40,000 IU).
All patients completed 16 weeks of follow-up. In the second part
of the study (part B), 12 patients in 4 cohorts received 4 weekly
infusions of 10, 20, 40, or 80 mg each of HBV-ABXTL and were followed
for 4 additional weeks. Administration of antibodies was well
tolerated. Patients administered doses at an Ab:Ag molar ratio
of 1:2 to 1:20 showed a rapid and significant decrease in HBsAg
to undetectable levels, with a corresponding reduction of HBV-DNA
levels. In part B, HBV-ABXTL induced a significant reduction in
both HBsAg and HBV-DNA levels repeatedly after administration.
In conclusion, these data suggest that HBV-ABXTL binds HBV particles
and reduces serum viral titers and HBsAg levels. HBV-ABXTL could
be combined with other monotherapies that are currently used to
treat HBV carriers. (HEPATOLOGY 2002;35:673-679.)
Hepatitis C virus kinetics during and immediately after liver
transplantation (*Human Study*)
Montserrat Garcia-Retortillo, Xavier Forns, Anna Feliu, Eduardo
Moitinho, Josep Costa, Miquel Navasa, Antoni Rimola, Juan Rodes
The study of hepatitis C virus (HCV) kinetics after liver transplantation
(LT) might be important to design strategies to prevent HCV infection
of the graft. We analyzed HCV kinetics during and immediately
after LT in 20 consecutive patients undergoing LT for HCV-related
cirrhosis. HCV RNA was quantified in blood samples obtained at
regular intervals before, during, and after transplantation. HCV-RNA
concentrations decreased in 18 of 20 patients during the anhepatic
phase (mean decay slope 0.92, mean HCV elimination half-life
2.2 hours). We found a significant correlation between the HCV
viral load decay and the blood loss during the anhepatic phase,
indicating that the observed HCV clearance rates are maximum estimates.
In fact, in 1 patient with an unusually long anhepatic phase of
20 hours and with minimum blood loss, the HCV elimination half-life
was 10.3 hours. Eight to 24 hours after graft reperfusion a sharp
decrease in HCV viral load occurred in 19 patients (mean decay
slope 0.34, mean HCV elimination half-life 3.44 hours). HCV
RNA became undetectable in only 1 patient. During the following
days, HCV-RNA concentrations increased rapidly in 10 patients
(mean HCV doubling time 13.8 hours), remained at similar levels
in 4, and continued to decrease in 6. The only variable associated
with a second-phase viral load decay was the absence of corticosteroids
as part of the immunosuppressive regimen. In conclusion, a sharp
decrease in HCV viral load occurs during the anhepatic phase and
immediately after graft reperfusion, most likely owing to a lack
of virion production and hepatic viral clearance. HCV infection
of the graft, however, is an extremely dynamic process and viral
replication begins a few hours after LT. (HEPATOLOGY 2002;35:680-687.)
Hepatic HCV RNA before and after treatment with interferon
alone or combined with ribavirin (*Human Study*)
John G. McHutchison, Thierry Poynard, Rafael Esteban-Mur, Gary
L. Davis, Zachary D. Goodman, Joann Harvey, Mei-Hsiu Ling, Jean
Jacques Garaud, Janice K. Albrecht, Keyur Patel, Jules L. Dienstag,
for the International Hepatitis Interventional Therapy Group
The clinical use of measuring hepatic hepatitis C virus (HCV) RNA before and after therapy in patients with chronic hepatitis C has been assessed in a number of small clinical trials. Viral clearance from the liver may be a better marker of long-term response than eradication of serum HCV RNA. The aim of this study was to evaluate quantitative hepatic HCV-RNA measurements before and after antiviral therapy. Two thousand eighty-nine chronic hepatitis C patients were enrolled in 3 published clinical trials evaluating interferon alfa-2b alone or with ribavirin either as initial therapy or for interferon relapse. Hepatic HCV-RNA quantitation was performed with a modified reverse-transcription polymerase chain reaction (RT-PCR) before and 24 weeks after therapy in 951 and 1,316 patients, respectively. Pretherapy hepatic HCV-RNA concentrations correlated best with serum HCV-RNA concentrations (R = .236, P = .0001) and negatively correlated with alanine transaminase (ALT) values (0.178, P = .0001), duration of infection (0.09, P = .02), parenchymal injury (0.135, P = .0001), histologic activity index (HAI) inflammatory score (0.085, P = .01), Knodell fibrosis score (0.072, P = .03), and body weight (0.078, P = .02). In paired liver biopsy specimens (n = 534), change in hepatic HCV RNA correlated with the change in the HAI (R = .346, P = .0001). Of 400 sustained virologic responders (SVR), 393 (98%) had undetectable hepatic HCV RNA, whereas 7 (2%) had detectable hepatic HCV RNA; 5 have been followed and 2 have had reappearance of serum HCV RNA 12 months after therapy. In conclusion, measurement of hepatic HCV RNA before or after therapy reflects changes observed in serum HCV RNA, and correlates inversely with hepatic inflammation and fibrosis, but otherwise has minimal clinical use. (HEPATOLOGY 2002;35:688-693.)
Interferon- inhibits replication of subgenomic and genomic
hepatitis C virus RNAs
Michael Frese, Verena Schwärzle, Kerstin Barth, Nicole Krieger,
Volker Lohmann, Sabine Mihm, Otto Haller, Ralf Bartenschlager
Persistent infection with hepatitis C virus (HCV) is a major
cause of chronic hepatitis, liver cirrhosis, and hepatocellular
carcinoma. All treatments known so far rely on the antiviral activity
of interferon alfa (IFN-) that is given alone or in combination
with ribavirin. Unfortunately, only a fraction of the patients
clear the virus during therapy and for those who do not respond
there is currently no alternative treatment. Selectable subgenomic
HCV RNAs (replicons) have been recently used to investigate the
effect of IFN- on HCV replication. However, it has not yet been
analyzed whether other cytokines also play a role in the innate
immune response against HCV. Here we show that IFN- inhibits protein
synthesis and RNA replication of subgenomic and genomic HCV replicons.
We further show that the inhibitory action of IFN- does not rely
on the production of nitric oxide or the depletion of tryptophan.
In conclusion, our results suggest that cytotoxic T cells and
natural killer cells may contribute to HCV clearance not only
by cell killing but also by producing IFN-, thereby enhancing
the intracellular inhibition of viral replication. (HEPATOLOGY
2002;35:694-703.)
Relationship of health-related quality of life to treatment
adherence and sustained response in chronic hepatitis C patients
(*Human Study*)
David Bernstein, Leah Kleinman, Chris M. Barker, Dennis A. Revicki,
Jesse Green
Interferon therapy may exacerbate health-related quality of
life (HRQL) deficits associated with hepatitis C virus (HCV) early
in the course of therapy. Treatment with polyethylene glycolmodified
interferon (peginterferon) alfa-2a (40 kd) provides improved sustained
response over interferon alfa-2a, but its effect on HRQL is unknown.
The objective of this study was to (1) evaluate the effect of
sustained virologic response on HRQL in patients with HCV and
(2) determine whether impairment of HRQL during treatment contributes
to early treatment discontinuation. Data consisted of a pooled
secondary analysis of patients (n = 1,441) across 3 international,
multicenter, open-label, randomized studies that compared peginterferon
alfa-2a (40 kd) with interferon alfa-2a. ANCOVA was used to examine
the effect of sustained virologic response on HRQL. Repeated-measures
mixed-models ANCOVA was used to compare Fatigue Severity Scale
(FSS) and SF-36 scores during treatment by treatment group. Logistic
regression analysis was used to examine the association between
changes at baseline in on-treatment HRQL and early treatment discontinuation.
Sustained virologic response was associated with marked improvements
from baseline to end of follow-up in all subjects, including patients
with cirrhosis. During treatment, patients receiving peginterferon
alfa-2a (40 kd) had statistically significantly better scores
on both the SF-36 and FSS. Baseline to 24-week changes in fatigue
and SF-36 mental and physical summary scores significantly predicted
treatment discontinuation. In conclusion, sustained virologic
response is associated with improvements in quality of life in
patients with or without advanced liver disease. This parameter
may be an important consideration in maximizing treatment adherence.
(HEPATOLOGY 2002;35:704-708.)
Modeling the hepatitis C virus epidemic in France using the
temporal pattern of hepatocellular carcinoma deaths (*Human
Study*)
Jenny Griffiths, Barry Nix
Deuffic et al. developed a compartmentalized model that characterized
the evolution and spread of the hepatitis C virus (HCV) within
France. There were various parameters defining the age- and sex-dependent
transition probabilities between chronic hepatitis and cirrhosis
in need of determination to completely specify their model. These
were estimated by means of a weighted least-squares procedure
that was executed numerically. The objective function used was
based on the distribution of the age at death from hepatocellular
carcinoma (HCC) rather than the temporal pattern of deaths due
to HCC from 1979 to 1995. In this report, we investigate the impact
of using an objective function based on the temporal pattern of
deaths. We show that the dynamics of the epidemic can be quite
different, in particular, short-term prediction of HCC deaths
by HCV infection and times to death from onset of disease. (HEPATOLOGY
2002;35:709-715.)
Hepatic encephalopathy-Definition, nomenclature, diagnosis,
and quantification: Final report of the Working Party at the 11th
World Congresses of Gastroenterology, Vienna, 1998
Peter Ferenci, Alan Lockwood, Kevin Mullen, Ralph Tarter, Karin
Weissenborn, Andres T. Blei, the Members of the Working Party
Research on hepatic encephalopathy is hampered by the imprecise definition of this disabling complication of liver disease. Under this light, the Organisation Mondiale de Gastroentérologie commissioned a Working Party to reach a consensus in this area and to present it at the 11th World Congress of Gastroenterology in Vienna (1998). The Working Party continued its work thereafter and now present their final report. In summary, the Working Party has suggested a modification of current nomenclature for clinical diagnosis of hepatic encephalopathy; proposed guidelines for the performance of future clinical trials in hepatic encephalopathy; and felt the need for a large study to redefine neuropsychiatric abnormalities in liver disease, which would allow the diagnosis of minimal (subclinical) encephalopathy to be made on firm statistical grounds. In the interim, it proposes the use of a psychometric hepatic encephalopathy score, based on the result of 5 neuropsychologic tests. Finally, the need for a careful evaluation of the newer neuroimaging modalities for the diagnosis of hepatic encephalopathy was stressed. (HEPATOLOGY 2002;35:716-721.)
RAPID COMMUNICATIONS
Artificial Neural Networks Distinguish Among Subtypes of
Neoplastic Colorectal Lesions
FLORIN M. SELARU, YAN XU, JING YIN, TONG ZOU, THOMAS C. LIU, YURIKO
MORI, JOHN M. ABRAHAM, FUMIAKI SATO, SUNA WANG, CHARLIE TWIGG,
ANDREEA OLARU, VALENTINA SHUSTOVA, ANATOLY LEYTIN, PRODROMOS HYTIROGLOU,
DAVID SHIBATA, NOAM HARPAZ, and STEPHEN J. MELTZER
Gastroenterology 2002 122: 606-613. Published online Feb 13 2002.
Background & Aims: There is a subtle distinction
between sporadic colorectal adenomas and cancers (SAC) and inflammatory
bowel disease (IBD)-associated dysplasias and cancers. However,
this distinction is clinically important because sporadic adenomas
are usually managed by polypectomy alone, whereas IBD-related
high-grade dysplasias mandate subtotal colectomy. The current
study evaluated the ability of artificial neural networks (ANNs)
based on complementary DNA (cDNA) microarray data to discriminate
between these 2 types of colorectal lesions. Methods:
We hybridized cDNA microarrays, each containing 8064 cDNA
clones, to RNAs derived from 39 colorectal neoplastic specimens.
Hierarchical clustering was performed, and an ANN was constructed
and trained on a set of 5 IBD-related dysplasia or cancer
(IBDNs) and 22 SACs. Results: Hierarchical clustering
based on all 8064 clones failed to correctly categorize the
SACs and IBDNs. However, the ANN correctly diagnosed 12 of
12 blinded samples in a test set (3 IBDNs and 9 SACs).
Furthermore, using an iterative process based on the computer
programs GeneFinder, Cluster, and MATLAB, we reduced the number
of clones used for diagnosis from 8064 to 97. Even with
this reduced clone set, the ANN retained its capacity for correct
diagnosis. Moreover, cluster analysis performed with these 97 clones
now separated the 2 types of lesions. Conclusions:
Our results suggest that ANNs have the potential to discriminate
among subtly different clinical entities, such as IBDNs and SACs,
as well as to identify gene subsets having the power to make these
diagnostic distinctions.
CLINICAL RESEARCH:
Resolution of Chronic Hepatitis B and Anti-HBs Seroconversion
in Humans by Adoptive Transfer of Immunity to Hepatitis B Core
Antigen
GEORGE K. K. LAU, DEEPAK SURI, RAYMOND LIANG, EIRINI I. RIGOPOULOU,
MARK G. THOMAS, IVANA MULLEROVA, AMIN NANJI, SIU-TSAN YUEN, ROGER
WILLIAMS, and NIKOLAI V. NAOUMOV
Gastroenterology 2002 122: 614-624. Published online Mar 1 2002.
Background & Aims: Impaired T-cell reactivity
is believed to be the dominant cause of chronic hepatitis B virus
(HBV) infection. We characterized HBV-specific T-cell responses
in chronic hepatitis B surface antigen carriers who received bone
marrow from HLA-identical donors with natural immunity to HBV
and seroconverted to antibody to hepatitis B surface antigen.
Methods: T-cell reactivity to HBV antigens and peptides
was assessed in a proliferation assay, the frequency of HBV core-
and surface-specific T cells was quantified directly by ELISPOT
assays, and T-cell subsets were analyzed by flow cytometry. Results:
CD4+ T-cell reactivity to HBV core was common in bone marrow donors
and the corresponding recipients after hepatitis B surface antigen
clearance, whereas none reacted to surface, pre-S1, or pre-S2
antigens. Furthermore, CD4+ T cells from donor/recipient pairs
recognized similar epitopes on hepatitis B core antigen; using
polymerase chain reaction for the Y chromosome, the recipients'
CD4+ T lymphocytes were confirmed to be of donor origin. The frequency
of core-specific CD4+ and CD8+ T cells was several-fold higher
than those specific for surface antigen. Conclusions: This
study provides the first evidence in humans that transfer of hepatitis
B core antigen-reactive T cells is associated with resolution
of chronic HBV infection. Therapeutic immunization with HBV core
gene or protein deserves further investigation in patients with
chronic hepatitis B.
Long-term Effect of H2RA Therapy on Nocturnal Gastric
Acid Breakthrough
WILLIAM K. FACKLER, TINA M. OURS, MICHAEL F. VAEZI, and JOEL E.
RICHTER
Gastroenterology 2002 122: 625-632. Published online Mar 1 2002.
Background & Aims: : Adding histamine
2 receptor antagonists (H2RAs) to proton pump inhibitor (PPI)
therapy is a common practice to block nocturnal acid breakthrough
(NAB). Controversy exists over its efficacy because of H2RA intolerance.
No prospective study has addressed this issue. Methods:
Twenty-three healthy volunteers and 20 gastroesophageal reflux
disease (GERD) patients were studied. Ambulatory pH monitoring
was performed with one electrode in the gastric fundus and the
other 5 cm above the lower esophageal sphincter. Baseline
pH testing was performed and repeated after 2 weeks on PPI
twice daily before meals (omeprazole 20 mg). All subjects
then received 28 days of PPI plus H2RA Qhs (ranitidine 300 mg)
with repeat pH testing on days 1, 7, and 28. Results:
Eighteen controls and 16 GERD patients completed all 5 studies.
Compared with baseline, all 4 medication regimens decreased
supine % time pH < 4 (P = 0.001).
The administration of PPI + 1 day of H2RA was the
only therapy that significantly decreased % time gastric
pH < 4 for the supine period compared with PPI
twice daily alone (P < 0.001). There was no
difference in % time supine gastric pH < 4 between
2 weeks of PPI twice daily alone and either 1 week or
1 month of PPI + bedtime H2RA. Conclusions:
The combination of H2RA and PPI therapy reduced NAB only with
the introduction of therapy. Because of H2RA tolerance, there
is no difference in acid suppression between PPI twice daily and
PPI twice daily + H2RA after 1 week of combination
therapy.
Surveillance and Survival in Barrett's Adenocarcinomas:
A Population-Based Study
DOUGLAS A. CORLEY, THEODORE R. LEVIN, LAUREL A. HABEL, NOEL S.
WEISS, and PATRICIA A. BUFFLER
Gastroenterology 2002 122: 633-640. Published online Mar 1 2002.
Background & Aims: Guidelines recommend
periodic endoscopic surveillance of Barrett's esophagus (BE) patients
to detect and treat early esophageal adenocarcinomas; however,
no trials or population-based studies exist. We evaluated the
association between endoscopic surveillance of BE and survival
among esophageal/gastric cardia adenocarcinoma patients. Methods:
We studied a cohort of 23 BE patients, among 589 esophageal
or gastric cardia adenocarcinoma patients diagnosed between 1990-1998
at Northern California Kaiser Permanente (a large health maintenance
organization). We measured the presence of BE, detection of cancer
by endoscopic surveillance, cancer stage, mortality, and potential
confounders. Results: BE was diagnosed in 135 of 589 adenocarcinoma
patients, with 23 BE patients diagnosed greater than 6 months
before cancer was diagnosed. Among these 23 patients, 73%
of the surveillance-detected cancer patients (n = 15)
were alive at the end of follow-up, compared with none of the
patients without surveillance-detected cancers (n = 8;
P = 0.001). All surveillance-detected cancer
patients had low-stage disease and none died directly from cancer.
The surveillance/survival association was not substantially altered
by stratification for age at BE diagnosis or other potential confounders.
Conclusions: Surveillance-detected BE-associated adenocarcinomas
were associated with low-stage disease and improved survival.
Additional studies are needed to evaluate potential biases and
whether screening/surveillance programs decrease mortality among
all patients in surveillance. Few patients (3.9%) had a BE diagnosed
before their cancer. Thus, even if current surveillance techniques
are effective, they are unlikely to substantially impact the population's
mortality from esophageal cancer; better methods are needed to
identify at risk patients.
Long-term Treatment With Sulindac in Familial Adenomatous
Polyposis: A Prospective Cohort Study
MARCIA CRUZ-CORREA, LINDA M. HYLIND, KATHARINE E. ROMANS, SUSAN
V. BOOKER, and FRANCIS M. GIARDIELLO
Gastroenterology 2002 122: 641-645. Published online Mar 1 2002.
Background & Aims: Management of patients
with familial adenomatous polyposis (FAP) can consist of colectomy
with ileorectal anastomosis (IRA). Sulindac, a nonsteroidal anti-inflammatory
drug, causes regression of colorectal adenomas in the retained
rectal segment of FAP patients, although long-term use of this
therapy has not been studied. We evaluated the long-term effectiveness
and toxicity of sulindac in attempting to maintain retained rectal
segments free of adenomas. Methods: Twelve FAP patients
(5 women), mean age 37.1 years, with IRA received sulindac
(mean dosage, 158 mg/day) for a mean period of 63.4 ± 31.3 months
(range, 14-98 months). Number, size, and histologic grade of polyps,
side effects, and medication compliance were assessed every 4 months.
Results: Seven of 12 patients (58%) remained in the
study (6 of these polyp-free) for a mean of 76.9 ± 27.5 months.
Five of 12 patients (42%) withdrew from the trial after a
mean follow-up period of 44 ± 28 months
(range, 14-89 months). A significant regression of polyp number
was observed in all patients at 12 months (P = 0.039)
and at a mean of 63.4 ± 31.3 months (P = 0.006).
Prevention of recurrence of higher-grade adenomas (tubulovillous,
villous adenomas) was also observed (P = 0.004).
At 35 months of follow-up, 1 patient developed stage
III cancer in the rectal stump. The most common side effect was
rectal mucosal erosions in 6 patients. Conclusions:
Long-term use of sulindac seems to be effective in reducing polyp
number and preventing recurrence of higher-grade adenomas in the
retained rectal segment of most FAP patients. Erosions at the
IRA site can preclude adequate dose maintenance.
A Population-Based Study of the Biochemical and Clinical
Expression of the H63D Hemochromatosis Mutation
PETER A. GOCHEE, LAWRIE W. POWELL, DIGBY J. CULLEN, DESIRÉE
DU SART, ENRICO ROSSI, and JOHN K. OLYNYK
Gastroenterology 2002 122: 646-651. Published online Mar 1 2002.
Background & Aims: Two major mutations
are defined within the hemochromatosis gene, HFE. Although
the effects of the C282Y mutation have been well characterized,
the effects of the H63D mutation remain unclear. We accessed a
well-defined population in Busselton, Australia, and determined
the frequency of the H63D mutation and its influence on total
body iron stores. Methods: Serum transferrin saturation
and ferritin levels were correlated with the H63D mutation in
2531 unrelated white subjects who did not possess the C282Y
mutation. Results: Sixty-two subjects (2.1%) were homozygous
for the H63D mutation, 711 (23.6%) were heterozygous, and
1758 (58.4%) were wild-type for the H63D mutation. Serum
transferrin saturation was significantly increased in male and
female H63D homozygotes and heterozygotes compared with wild-types.
Serum ferritin levels within each gender were not influenced by
H63D genotypes. Elevated transferrin saturation 45% was observed
in a greater proportion of male H63D carriers than male wild-types.
Male H63D homozygotes (9%) and heterozygotes (3%) were more likely
to have both elevated transferrin saturation and elevated ferritin
300 ng/mL than male wild-types (0.7%). Homozygosity for H63D was
not associated with the development of clinically significant
iron overload. Conclusions: Presence of the H63D mutation
results in a significant increase in serum transferrin saturation
but does not result in significant iron overload. In the absence
of the C282Y mutation, the H63D mutation is not clinically significant.
Primary Biliary Cirrhosis: Incidence and Predictive Factors
of Cirrhosis Development in Ursodiol-Treated Patients
CHRISTOPHE CORPECHOT, FABRICE CARRAT, RAOUL POUPON, and RENEE-EUGENIE
POUPON
Gastroenterology 2002 122: 652-658. Published online Mar 1 2002.
Background & Aims: Ursodeoxycholic acid
(UDCA) slows the progression of primary biliary cirrhosis (PBC).
However, some UDCA-treated patients escape and progress toward
cirrhosis and end-stage disease. This study aimed to assess the
incidence of cirrhosis in UDCA-treated patients with PBC and to
determine the predictive factors of cirrhosis development under
this treatment. Methods: A Markov model was used to describe
the progression toward cirrhosis in 183 UDCA-treated patients
with PBC. A total of 254 pairs of liver biopsy specimens
collected during 655 patient-years were studied. Results:
The incidence of cirrhosis after 5 years of UDCA treatment
was 4%, 12%, and 59% among patients followed-up from stages I,
II, and III, respectively. At 10 years, the incidence was
17%, 27%, and 76%, respectively. The median time for developing
cirrhosis from stages I, II, and III was 25 years, 20 years,
and 4 years, respectively. The independent predictive factors
of cirrhosis development were serum bilirubin greater than 17 µmol/L,
serum albumin less than 38 g/L, and moderate to severe lymphocytic
piecemeal necrosis. Conclusions: This study provides new
data about the time course of PBC under UDCA and constitutes a
rationale for the design and evaluation of clinical trials aimed
to assess the efficacy of drugs associated with UDCA.
BASIC RESEARCH:
TRAIL and Its Receptors in the Colonic Epithelium: A Putative
Role in the Defense of Viral Infections
JÖRN STRÄTER, HENNING WALCZAK, TANJA PUKROP, LUTZ VON
MÜLLER, CORNELIA HASEL, MARKO KORNMANN, THOMAS MERTENS, and
PETER MÖLLER
Gastroenterology 2002 122: 659-666. Published online Mar 1 2002.
Background & Aims: Tumor necrosis factor-related
apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis
factor family and induces apoptosis by cross-linking either of
the 2 TRAIL receptors containing a death domain (TRAIL-R1
or TRAIL-R2). TRAIL-R3 and TRAIL-R4 are receptors that do not
transmit an apoptotic signal. The aim of this study was to investigate
the expression and function of TRAIL and its receptors in normal
colonic epithelium. Methods: TRAIL and TRAIL receptor expression
was studied by reverse-transcriptase polymerase chain reaction
and immunohistochemistry. TRAIL sensitivity of epithelial cells
was determined in vitro. Results: Normal colonic epithelial
cells express TRAIL, TRAIL-R1, TRAIL-R2, and TRAIL-R4. Interestingly,
TRAIL and TRAIL-R2 are coexpressed mostly in the luminal surface
epithelium. Despite the expression of apoptosis-mediating TRAIL
receptors, the normal colonic crypt epithelium is completely resistant
to TRAIL-induced apoptosis in vitro. Using an infection model
with restricted human cytomegalovirus gene expression or productive
adenovirus infection in the colon carcinoma cell line Caco-2,
we show that TRAIL sensitivity of colonic epithelial cells is
induced on virus infection along with an up-regulation of TRAIL-R1
and TRAIL-R2 on the cell surface. Conclusions: We conclude
that the TRAIL system may play a role in the early elimination
of virus-infected epithelial cells in the normal gut.
Ubiquitous Production of Macrophage Migration Inhibitory
Factor by Human Gastric and Intestinal Epithelium
CHRISTIAN MAASER, LARS ECKMANN, GÜNTHER PAESOLD, HYUN S.
KIM, and MARTIN F. KAGNOFF
Gastroenterology 2002 122: 667-680. Published online Mar 1 2002.
Background & Aims: Macrophage migration
inhibitory factor (MIF) inhibits macrophage migration and has
pleiotropic activities on immune and inflammatory responses, cell
growth, and glucose metabolism. MIF is produced by T cells, macrophages,
and endothelial cells. Because intestinal epithelial cells produce
mediators important for regulating mucosal immune and inflammatory
responses, we sought to determine if these cells produce MIF.
Methods: MIF expression was determined by immunostaining
of human intestinal mucosa, intestinal xenografts, and cultured
cells. MIF protein levels were quantitated by enzyme-linked immunosorbent
assay and immunoblot analysis, messenger RNA was assessed by real-time
reverse-transcription polymerase chain reaction, and functional
activity was assessed by enzymatic and migration assays. Results:
MIF was abundantly expressed in vivo in gastric, small intestinal,
and colonic epithelium and in epithelium lining human intestinal
xenografts. MIF was also constitutively expressed at the messenger
RNA and protein level by several cultured colon and gastric epithelial
cell lines, and its expression in those cells was not up-regulated
by the proinflammatory cytokines interleukin 1, tumor necrosis
factor , or interferon gamma. Epithelial MIF from cultured cells
was released predominantly from the apical side after Salmonella
infection, had tautomerase activity, and arrested macrophage migration.
Conclusions: Human intestinal epithelial cells are a major
source of MIF, a molecule that can regulate macrophage migration,
inflammation, and cell metabolism.
Increased Sensitivity to the Locomotor-Activating Effects
of Corticotropin-Releasing Hormone in Cholestatic Rats
KELLY W. BURAK, TAI LE, and MARK G. SWAIN
Gastroenterology 2002 122: 681-688. Published online Mar 1 2002.
Background & Aims: Fatigue is a common
complaint of patients with cholestatic liver disease. Defective
central corticotropin-releasing hormone (CRH) release has been
postulated as playing a role in the genesis of fatigue and decreased
hypothalamic CRH expression has been identified in an animal model
of cholestatic liver injury. Therefore, we hypothesized that reduced
central CRH release contributes to fatigue associated with cholestatic
liver disease and tested this hypothesis in cholestatic rats.
Methods: Locomotor activity during prolonged observation,
measured by using an infrared beam activity monitor, was used
as a surrogate marker of fatigue or fatigability. Rats with cholestasis
secondary to bile duct resection (BDR) had significantly lower
basal locomotor activity compared with sham controls. Results:
Intracerebroventricular injections of CRH (0.05, 0.1, 1.0 µg/rat)
caused significantly greater locomotor activation in BDR animals
than controls. In BDR rats, this locomotor activation was blocked
by the coadministration of the nonspecific CRH-receptor antagonist
astressin (25 µg/rat) and the specific CRH type 1-receptor
antagonist NBI-27941 (10 µg/rat). Immunoblotting showed
a dramatic increase in hypothalamic CRH type 1-receptor expression
in BDR rats compared with controls, which was paralleled by a
striking reduction in hypothalamic CRH levels. Conclusions:
These findings are consistent with defective central CRH neurotransmission
contributing to decreased locomotor activity in cholestatic rats
and have direct implications for cholestasis-associated fatigue.
Cdx2 Ectopic Expression Induces Gastric Intestinal Metaplasia
in Transgenic Mice
DEBRA G. SILBERG, JESSICA SULLIVAN, EUGENE KANG, GARY P. SWAIN,
JENNIFER MOFFETT, NEWMAN J. SUND, SARA D. SACKETT, and KLAUS H.
KAESTNER
Gastroenterology 2002 122: 689-696. Published online Mar 1 2002.
Background & Aims: Intestinal-type gastric
cancer is often preceded by intestinal metaplasia in humans. The
genetic events responsible for the transdifferentiation that occurs
in intestinal metaplasia are not well understood. Cdx2,
a transcription factor whose expression is normally limited to
the intestine, has been detected in gastric intestinal metaplasia.
Cdx2 induces differentiation of intestinal epithelial cells in
vitro; therefore, we sought to establish whether a causal relationship
exists between Cdx2 activation and intestinal metaplasia.
Methods: Cdx2 expression was directed to the gastric
mucosa in transgenic mice using cis-regulatory elements
of Foxa3 (Hnf3). Transgenic mice were analyzed for
histologic and gene expression changes. Results: Histologic
examination of the gastric mucosa of the Foxa3/Cdx2 mice
revealed the presence of alcian blue-positive intestinal-type
goblet cells, a hallmark of intestinal metaplasia. In addition,
Cdx2 induced the expression of intestine-specific genes.
Conclusions: Gastric expression of Cdx2 alone was
sufficient to induce intestinal metaplasia in mice. These mice
represent a powerful tool to investigate the molecular mechanisms
that promote intestinal metaplasia. Moreover, as gastric cancer
in humans is often preceded by intestinal metaplasia, the phenotype
described here strongly suggests involvement of Cdx2 in
the initiation of the process leading to intestinal neoplasia
of the gastric mucosa.
Induction of Anaphylatoxin C5a Receptors in Rat Hepatocytes
by Lipopolysaccharide In Vivo: Mediation by Interleukin-6 From
Kupffer Cells
MILENA KOLEVA, GERALD SCHLAF, REGINE LANDMANN, OTTO GÖTZE,
KURT JUNGERMANN, and HENRIKE L. SCHIEFERDECKER
Gastroenterology 2002 122: 697-708. Published online Mar 1 2002.
Background & Aims: In normal rat liver,
anaphylatoxin C5a induces glucose output from hepatocytes indirectly
via prostanoids released from Kupffer cells. Correspondingly,
it was found that hepatocytes, in contrast to Kupffer cells, did
not express C5a receptors. Lipopolysaccharide (LPS) has been reported
to enhance C5a receptor expression in murine livers. This might
be the result of de novo expression in hepatocytes. Methods:
C5a receptor expression was investigated in hepatocytes after
in vivo treatment of rats with LPS and in vitro stimulation of
isolated cells with LPS and proinflammatory cytokines on messenger
RNA (mRNA) and protein level, and functionally in isolated hepatocytes
and perfused liver. Results: In vivo treatment of rats
with LPS induced C5a receptor mRNA and protein in hepatocytes
with a maximum after 8-10 hours. At this time-point, C5a directly
activated glycogen phosphorylase in isolated hepatocytes and enhanced
glucose output in perfused livers without the involvement of prostanoids.
LPS failed to induce C5a receptors in cultured hepatocytes in
vitro, whereas interleukin (IL) 6 and IL-1, which are known
to be released from Kupffer cells on stimulation with LPS, did
so. In cocultures of hepatocytes with Kupffer cells, LPS induced
C5a receptors in hepatocytes in an IL-6-dependent manner. Conclusions:
Thus, IL-6 from Kupffer cells appears to be the main mediator
of LPS-induced de novo expression of C5a receptors in hepatocytes.
Down-regulated in Adenoma Mediates Apical Cl/HCO3
Exchange in Rabbit, Rat, and Human Duodenum
PETRA JACOB, HEIDI ROSSMANN, GEORG LAMPRECHT, ALEXANDRA KRETZ,
CHRISTINA NEFF, ELENA LIN-WU, MICHAEL GREGOR, DAVID A. GRONEBERG,
JUHA KERE, and URSULA SEIDLER
Gastroenterology 2002 122: 709-724. Published online Mar 1 2002.
Background & Aims: Duodenal bicarbonate
secretion is in part mediated by an apical Cl/HCO3 exchanger of
unknown molecular nature. The recently discovered dra (down-regulated
in adenoma) gene encodes a transport protein (DRA) for SO42, Cl,
and HCO3. The aim of this study was to investigate whether DRA
may be the duodenal apical Cl/HCO3 exchanger. Methods:
DRA, Na+/H+ exchanger (NHE) isoform 3, and anion exchanger
isoform (AE) 2 messenger RNA expression levels were studied
in rat, rabbit, and human gastrointestinal tract by semiquantitative
reverse-transcription polymerase chain reaction and in situ hybridization
(DRA in human intestine). The subcellular localization of DRA
was determined by Western analysis and immunohistochemistry. Using
rabbit and rat duodenal brush border membrane vesicles, anion
exchange characteristics were investigated. Results: DRA
expression was high in duodenum and colon of all species, whereas
NHE3 messenger RNA expression was low in duodenum and high in
colon. Western analysis and immunohistochemistry showed an apical
localization for DRA. Rabbit and rat duodenal brush border membrane
vesicles showed 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid-sensitive
Cl/Cl, HCO3/Cl, SO42/Cl, and Cl/SO42 exchange, with evidence for
one major brush border membrane Cl/anion exchanger, an affinity
for Cl > HCO3, and a much higher affinity for SO42
in rat than rabbit. The strong predominance of DRA over NHE3 and
NHE2 expression in duodenum was paralleled by much higher Cl/HCO3
than Na+/H+ exchange rates in brush border membrane vesicles and
likely explains the high duodenalHCO3 secretory rates. Conclusions:
These data suggest that DRA is the major apical anion exchanger
in the duodenum as well as the colon and the likely transport
protein for duodenal electroneutral HCO3 secretion.
Genetic Deficiency in the Chemokine Receptor CCR1 Protects
Against Acute Clostridium difficile Toxin A Enteritis
in Mice
OLIVIER MORTEAU, IGNAZIO CASTAGLIUOLO, ANDREAS MYKONIATIS, JEFF
ZACKS, MICHAEL WLK, BAO LU, CHARALABOS POTHOULAKIS, NORMA P. GERARD,
and CRAIG GERARD
Gastroenterology 2002 122: 725-733. Published online Mar 1 2002.
Background & Aims: The role of the CC
chemokine receptor (CCR) 1 in acute enteritis was investigated
by subjecting CCR1 knockout mice to Clostridium difficile
toxin A treatment. Methods: Toxin A or vehicle was injected
into ileal loops in anesthetized wild-type, CCR1-/- and macrophage
inhibitory protein (MIP)-1/ mice. After 1-4 hours, fluid accumulation
was calculated, and the loops were processed for histology, myeloperoxidase
activity, regulated on activation, normal T cell expressed and
secreted (RANTES) production, and messenger RNA measurements.
Results: Toxin A induced in all mice a significant (P < 0.05)
increase in ileal fluid accumulation, epithelial damage, and neutrophil
infiltration, with all parameters being significantly (P < 0.01)
lower in CCR1/ and MIP-1 / mice. Ileal messenger RNA expression
of the CCR1 ligands MIP-1 and RANTES and RANTES synthesis were
increased in toxin A-treated wild-type mice. The RANTES antagonist
Met-RANTES significantly (P < 0.01) reduced
the toxin A-induced increases in ileal fluid accumulation and
myeloperoxidase activity in wild-type mice. Conclusions:
C. difficile toxin A-induced murine enteritis involves
CCR1 and its ligands MIP-1 and RANTES, which may be important
mediators of the neutrophil recruitment characterizing acute,
enterotoxin-mediated enteritis.
Intravital Observation of Adhesion of Lamina Propria Lymphocytes
to Microvessels of Small Intestine in Mice
HITOSHI FUJIMORI, SOICHIRO MIURA, SEIICHIRO KOSEKI, RYOTA HOKARI,
SHUNSUKE KOMOTO, YURIKO HARA, SATOSHI HACHIMURA, SHUICHI KAMINOGAWA,
and HIROMASA ISHII
Gastroenterology 2002 122: 734-744. Published online Mar 1 2002.
Background & Aims: Although the recirculation
of lymphocytes through the intestinal mucosa is important for
the specific immune defense, the homing of lamina propria lymphocytes
(LPLs) has not been clearly understood. The aim of this study
is to compare, under an intravital microscope, the dynamic process
of lymphocyte-endothelium recognition and binding in the murine
intestinal mucosa of T lymphocytes from the lamina propria of
intestine to that of T lymphocytes from the spleen. Methods:
LPLs isolated from nonlymphoid areas of the small intestine and
spleen (SPL) were fluorescence-labeled and injected into a jugular
vein of recipient mice. Microvessels of the villus mucosa and
ileal Peyer's patches were observed under an intravital fluorescence
microscope, and the effects of anti-adhesion-molecule antibodies
on lymphocyte-endothelial interaction were investigated. Results:
LPLs accumulated abundantly in the microvessels of villus tips
but not in the submucosal venules or postcapillary venules of
Peyer's patches, where SPLs migrated selectively. The accumulation
of LPLs in the villus tips was almost completely inhibited by
anti-7-integrin and was significantly inhibited by anti-mucosal
addressin cell-adhesion molecule 1 (MAdCAM-1) and anti-4-integrin.
Significant MAdCAM-1 expression was observed in the microvessels
of the villus mucosa. Some SPLs adhered to the nonlymphoid mucosa,
but most soon detached. Conclusions: It was shown in vivo
for the first time that T lymphocytes from the lamina propria
but not from the spleen adhere selectively, mostly via 47 and
MAdCAM-1, to the microvessels of villus tips of the intestine,
but not to the postcapillary venules of Peyer's patches.
Inactivation of the Hemochromatosis Gene Differentially
Regulates Duodenal Expression of Iron-Related mRNAs Between Mouse
Strains
FRANÇOISE DUPIC, SÉVERINE FRUCHON, MOUNIA BENSAID,
NICOLAS BOROT, MIRJANA RADOSAVLJEVIC, OLIVIER LOREAL, PIERRE BRISSOT,
SUSAN GILFILLAN, SIAMAK BAHRAM, HÉLÈNE COPPIN, and
MARIE-PAULE ROTH
Gastroenterology 2002 122: 745-751. Published online Mar 1 2002.
Background & Aims: Hfe knockout
mice, like patients with hereditary hemochromatosis, have augmented
duodenal iron absorption and increased iron deposition in hepatic
parenchymal cells. The goals of the present study were to gain
further insight into the control of iron absorption by comparing
the transcript levels of iron-related genes in the duodenum of
DBA/2 Hfe/ mice, susceptible to iron loading, and wild-type
controls, and to test whether variations in the duodenal expression
of these messengers contribute to the DBA/2 and C57BL/6 strain
differences in the severity of hepatic iron loading. Methods:
Expression of the different transcripts was quantified by real-time
polymerase chain reaction. Results: The 2 strains
differ strikingly, not only in the severity of hepatic iron loading,
but also in the duodenal expression of iron-related genes. In
DBA/2 Hfe/ mice, increased intestinal iron absorption results
from the concomitant up-regulation of the Dcytb, DMT1, and FPN1
messengers. No increase in the expression of these messengers
is seen in C57BL/6 Hfe/ mice. Conclusions: The up-regulation
of these transcripts suggests that an inappropriate iron-deficiency
signal is sensed by the duodenal enterocytes, leading to an enhanced
ferric reductase activity and the increase of duodenal iron uptake
and transfer to the circulation. The genes modifying the hemochromatosis
phenotype probably act by modifying the expression of these 3 messengers.
Mild Gastritis Alters Voltage-Sensitive Sodium Currents
in Gastric Sensory Neurons in Rats
KLAUS BIELEFELDT, NORIYUKI OZAKI, and GERALD F. GEBHART
Gastroenterology 2002 122: 752-761. Published online Mar 1 2002.
Background & Aims: Visceral hypersensitivity
can be found in more than one third of patients with dyspeptic
symptoms. We hypothesized that peripheral sensitization plays
an important role in the development of hypersensitivity. Methods:
We induced mild gastritis in Sprague-Dawley rats by adding 0.1%
iodoacetamide to the drinking water. The stomach was injected
with a retrograde label to identify gastric sensory neurons. Nodose
and T9, T10 dorsal root ganglia were removed 7 days after
initiation of iodoacetamide treatment. The cells were dissociated
and cultured for 3-8 hours before recording whole cell currents
using the patch-clamp technique. Results: Iodoacetamide
induced a mild gastritis. Although there were no changes in voltage-sensitive
inward and outward currents in nodose neurons, the inward currents
increased significantly in T9, T10 spinal neurons. A more detailed
analysis of sodium currents showed that this was caused by an
increase in the tetrodotoxin-resistant sodium current. Conclusions:
Mild gastritis increases the tetrodotoxin-resistant current in
gastric spinal sensory neurons. Considering the importance of
sodium currents as determinants of neuron excitability, this change
may contribute to peripheral sensitization and enhanced neuron
excitability.
CD40/CD154 Ligation Is Required for the Development of Acute
Ileitis Following Oral Infection With an Intracellular Pathogen
in Mice
WEN LI, DOMINIQUE BUZONI-GATEL, HAJER DEBBABI, MARK S. HU, FRANCK
J. D. MENNECHET, BRIGIT G. DURELL, RANDOLPH J. NOELLE, and LLOYD
H. KASPER
Gastroenterology 2002 122: 762-773. Published online Mar 1 2002.
Background & Aims: Acute inflammatory
ileitis occurs in C57BL/6 mice after oral infection with Toxoplasma
gondii. We evaluated the role of CD40/CD154 interaction in
the development of acute ileitis in this experimental model. Methods:
CD154/ and anti-CD154 antibody-treated mice as well as chimeric
mice, either C57BL/6 or CD40/ reconstituted with bone marrow from
C57BL/6 or CD40/ mice, were orally infected with cysts. Inflammation
was assessed by qualitative histologic and phenotypic analysis
of the intestinal compartment at day 7 after infection. Intestinal
chemokine and cytokine production was assayed by ribonuclease
protection assay. Results: CD154/ and anti-CD154 monoclonal
antibody-treated mice failed to develop an acute, lethal ileitis
after oral infection and survived. Chimeric mice reconstituted
with bone marrow from C57BL/6 mice developed ileitis and died,
whereas those recipient mice deficient in CD40 survived. CD40
expression in the intestine after infection was found principally
within the B-cell compartment. A modest increase in CD40 expression
in both the macrophage and dendritic cell compartments was also
observed. Both chemokine and cytokine expression was up-regulated
in those recipients of wild-type bone marrow. Impairment of CD40/CD154
interaction abrogated the production of these proinflammatory
productions. Conclusions: CD40/CD154 interaction is essential
to the development of inflammation in this pathogen-driven experimental
model of acute ileitis.
-Multiple Mechanisms in Indomethacin-Induced Impairment
of Hepatic Cytochrome P450 Enzymes in Rats
YASUHIRO MASUBUCHI, EMI MASUDA, and TOSHIHARU HORIE
Gastroenterology 2002 122: 774-783. Published online Mar 1 2002.
Background & Aims: Indomethacin impairs
liver microsomal monooxygenase activities mediated by cytochrome
P450 (CYP). We investigated the inhibition mechanism and the isoform
selectivity in vitro and in vivo. Methods: In an in vitro
study, liver microsomes from male Wistar rats were preincubated
with indomethacin and a reduced nicotinamide adenine dinucleotide
phosphate-generating system, followed by assay of monooxygenase
activities indicative of several CYP isoforms. In an in vivo study,
rats were intraperitoneally treated with indomethacin, followed
by preparation of microsomes and the enzyme assays. Results:
The preincubation of microsomes with indomethacin and reduced
nicotinamide adenine dinucleotide phosphate decreased CYP3A2 activity
but not any other isoforms. Kinetic analysis showed the mechanism-based
inactivation of CYP3A2. The metabolism of [14C]indomethacin resulted
in covalent binding to microsomal protein, which was diminished
by inhibiting CYP3A enzyme. Administration of indomethacin caused
impairment of not only CYP3A2 but also other CYP isoforms. Rats
were protected from the impairment of the CYP enzymes except CYP3A2
by depleting macrophages and inhibiting inducible nitric oxide
synthase. Conclusions: Metabolism of indomethacin causes
inactivation of CYP3A2, which is the result of the covalent binding
of its metabolite, whereas partially selective in vivo impairment
of CYP isoforms is suggested to be indirect inhibition by inflammatory
mediators probably released from Kupffer cells.
CASE REPORTS:
Molecular Evidence for the Same Clonal Origin of Both Components
of an Adenosquamous Barrett Carcinoma
BASTIAAN P. van REES, REMIGIO W. ROUSE, MIREILLE J. de WIT, CAREL
J. M. van NOESEL, GUIDO N. J. TYTGAT, J. JAN B. van LANSCHOT,
and G. JOHAN A. OFFERHAUS
Gastroenterology 2002 122: 784-788. Published online Mar 1 2002.
We describe an uncommon case of adenosquamous carcinoma arising
in a Barrett esophagus in a 72-year-old white man who occasionally
used alcohol, and was a nonsmoker for 34 years. Polymerase
chain reaction-based microsatellite analysis was performed on
the adenocarcinoma component (AC) and squamous cell carcinoma
component (SC) of the tumor. The metaplastic Barrett epithelium
(BE), the AC and the SC all showed loss of the same allele at
4 markers on chromosome 9p. Furthermore, the AC and the SC
both showed loss of the same allele at all informative markers
tested on chromosomal arms 3p, 5q, 10q, 14q, and 18q. In addition,
both the SC and AC component contained the same missense mutation
in the p53 tumor-suppressor gene. The only observed difference
was a shift at a marker on chromosome 16q in the AC, whereas no
shift was found in the BE and the SC. These findings suggest that
this biphasic tumor has a monoclonal origin. The divergence presumably
occurred late in the tumorigenesis of this carcinoma.
A Homozygous HFE Gene Splice Site Mutation (IVS5+1
G/A) in a Hereditary Hemochromatosis Patient of Vietnamese Origin
MICHAEL STEINER, KENNETH OCRAN, JANINE GENSCHEL, PATRICK MEIER,
HELGA GERL, MICHAEL VENTZ, MARIE-LUISE SCHNEIDER, CARSTEN BÜTTNER,
KAMILLA WADOWSKA, WOLFGANG KERNER, PETER SCHUFF-WERNER, HERBERT
LOCHS, and HARTMUT SCHMIDT
Gastroenterology 2002 122: 789-795. Published online Mar 1 2002.
The vast majority of Caucasian patients presenting with hereditary
hemochromatosis demonstrate a single homozygous missense mutation
in the HFE gene (C282Y). The underlying genetic defects in hemochromatosis
patients of non-Caucasian origin are largely unknown. A 48-year-old
man of Vietnamese origin presented with insulin-dependent diabetes
mellitus, tertiary adrenocortical insufficiency, and laboratory
results highly indicative of hereditary hemochromatosis. Because
the patient was negative for the known HFE gene mutations C282Y,
H63D, and S65C HFE, the entire coding region and intron/exon boundaries
of the HFE gene was investigated. Sequencing studies identified
a homozygous G-to-A transition at position +1 of intron 5 (IVS5+1
G/A). This newly described mutation alters the invariant G at
position +1 of the 5' splice site causing altered mRNA splicing
and exon skipping with exon 4 being spliced to exon 6. Both
heterozygously affected children (age 19 and 20 years)
had moderately increased ferritin levels with normal serum iron
concentration and transferrin saturation. The newly described
mutation was not detected in a control group consisting of 220 Caucasian
individuals as verified by allele-specific polymerase chain reaction.
We describe for the first time a homozygous HFE splice site mutation
(IVS5+1 G/A) in a non-Caucasian patient with hereditary hemochromatosis.
Although the absence of this novel HFE gene mutation in Caucasian
subjects suggests that the mutation is exclusive to this family,
mutation screening in populations of different ethnic background
is recommended to precisely define its contribution to hereditary
hemochromatosis in non-Caucasian patients.
A Syndrome of Hereditary Pancreatic Adenocarcinoma and Cysts
of the Liver and Kidneys
LAWRENCE K. GATES, JR. and DAWN V. HOLLADAY
Gastroenterology 2002 122: 796-799. Published online Mar 1 2002.
Pancreatic adenocarcinoma is the fifth leading cause of cancer
death in developed countries. Several family and population studies
have suggested that there is a genetic predisposition in about
10% of cases. Despite this, pedigrees showing a definite Mendelian
inheritance pattern are quite rare. Recently, a family came to
our attention with several cases of pancreatic adenocarcinoma.
A detailed family medical history was obtained from the index
patient. Medical records, including death certificates, histopathology,
radiology, and laboratory reports from several family members
were reviewed. Computerized tomography scans and CA19-9 serum
assays were performed on selected family members. The family seems
to have a syndrome of autosomal dominant adenocarcinoma of the
pancreas, accompanied by multiple cysts of the liver and kidneys.
Affected family members without pancreatic cancer have elevated
serum CA19-9 levels. This seems to be a previously undescribed
syndrome. The family may be carrying a tumor suppressor gene mutation
specific for pancreatic adenocarcinoma.
Successful Infliximab Treatment for Steroid-Refractory Celiac
Disease: A Case Report
HELEN R. GILLETT, IAN D. R. ARNOTT, MARGARET McINTYRE, SIMON CAMPBELL,
ANNA DAHELE, MATTHEW PRIEST, ROBERT JACKSON, and SUBRATA GHOSH
Gastroenterology 2002 122: 800-805. Published online Mar 1 2002.
Celiac disease is a T cell-mediated enteropathy induced by
gluten in genetically predisposed individuals. The majority of
patients responds to a gluten-free diet but a small number do
not. After the exclusion of gluten in the diet, ulcerative jejunititis,
and an enteropathy-associated T-cell lymphoma, another treatment
modalities, such as systemic steroids and immunosuppressives,
may be necessary. This article reports the case of a 47-year-old
white woman with immunoglobulin A deficiency. She was diagnosed
with celiac disease with subtotal villous atrophy on jejunal biopsy
together with positive antiendomysium and antigliadin immunoglobulin
G antibodies. Despite close adherence to a gluten-free diet, her
weight continued to decrease, she had diarrhea, and her distal
duodenal histology showed no improvement. Some improvement in
her symptoms was observed with cyclosporine and systemic steroids,
but this was not sustained. Recent evidence has suggested that
anti-tumor necrosis factor antibodies have a role in the
amelioration of an animal model of villous atrophy, and after
careful consideration, she was treated with infliximab. There
was a dramatic improvement in her weight, symptoms, and distal
duodenal histology. The response has been maintained for 18 months
while on azathioprine therapy. It is concluded that infliximab
is an effective treatment that may be considered in a small number
of patients with refractory celiac disease, resistant to other
therapy.
Hepatocytes and Epithelial Cells of Donor Origin in Recipients
of Peripheral-Blood Stem Cells
Martin Körbling, M.D., Ruth L. Katz, M.D., Abha Khanna,
M.A., Arnout C. Ruifrok, Ph.D., Gabriela Rondon, M.D., Maher Albitar,
M.D., Richard E. Champlin, M.D., and Zeev Estrov, M.D.
Background : Bone marrow contains stem cells with the potential to differentiate into mature cells of various organs. We determined whether circulating stem cells have a similar potential.
Methods : Biopsy specimens from the liver, gastrointestinal tract, and skin were obtained from 12 patients who had undergone transplantation of hematopoietic stem cells from peripheral blood (11 patients) or bone marrow (1 patient). Six female patients had received transplants from a male donor. Five had received a sex-matched transplant, and one had received an autologous transplant. Hematopoietic stem-cell engraftment was verified by cytogenetic analysis or restriction-fragmentlength polymorphism analysis. The biopsies were studied for the presence of donor-derived epithelial cells or hepatocytes with the use of fluorescence in situ hybridization of interphase nuclei and immunohistochemical staining for cytokeratin, CD45 (leukocyte common antigen), and a hepatocyte-specific antigen.
Results : All six recipients of sex-mismatched transplants showed evidence of complete hematopoietic donor chimerism. XY-positive epithelial cells or hepatocytes accounted for 0 to 7 percent of the cells in histologic sections of the biopsy specimens. These cells were detected in liver tissue as early as day 13 and in skin tissue as late as day 354 after the transplantation of peripheral-blood stem cells. The presence of donor cells in the biopsy specimens did not seem to depend on the intensity of tissue damage induced by graft-versus-host disease.
Conclusions : Circulating stem cells can
differentiate into mature hepatocytes and epithelial cells of
the skin and gastrointestinal tract.
Age at acquisition of Helicobacter pylori infection: a follow-up
study from infancy to adulthood (Full
text)
Hoda M Malaty, Abdalla El-Kasabany,
David Y Graham, Charles C Miller, Sidd G Reddy, Sathanur R Srinivasan,
Yoshio Yamaoka, Gerald S Berenson
Background Helicobacter pylori infection is common worldwide, but the time of acquisition is unclear. We investigated this issue in a cohort of children selected retrospectively from a population followed up for 21 years. Methods We monitored 224 children (99 black, 125 white; 110 male, 114 female) from 1975-76 (ages 1-3 years) to 1995-96. H pylori status was assessed by presence of serum IgG antibodies. Findings 18 (8·0%) children at age 1-3 years had H pylori antibodies (13% black vs 4% white children, p=0·008). By age 18-23 years, the prevalence of the infection was 24·5% (43% black vs 8% white participants, p<0·0001). Of the 206 children not infected at baseline, 40 (19%) became infected by age 21-23. The crude incidence rate per year was 1·4% for the whole cohort, ranging from 2·1% at 4-5 years and 1·5% at age 7-9 years to 0·3% at 21-23 years. The seroconversion rate was higher among black than among white children (relative risk 3·3, 95% CI 1·8-6·2, p=0·001). The median age for seroconversion was 7·5 years for both races. Nine of the 58 seropositive children cleared the infection during follow-up. The rate of seroreversion per year was 1·1%; it was highest among children at age 4-5 years (2·2% vs 0·2% at ages 18-19). Interpretation Most newly acquired H pylori infections happened before age 10 years. Treatment and preventive strategies should be aimed at children in this age-group. Lancet 2002; 359: 931-35
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