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Cirrhosis resulting from hepatitis C virus is presently the most common indication for liver transplantation (OLT) in the United States. A number of U.S. transplant centers require cirrhotics who are using methadone to discontinue it before proceeding with OLT. We sought to examine the outcomes of those patients who had undergone OLT at the Mount Sinai Medical Center. A retrospective chart review of 36 subjects on methadone maintenance treatment (MMT), and off heroin, at the time of OLT was performed. The median daily methadone dose pre-OLT was 50 mg. Post-OLT, there was an increase in methadone dose in 15 subjects, a decrease in four subjects, and no dose change in 17 subjects. Four subjects had documented single episodes of intravenous drug use post-OLT; only one subject had a dose change after the event. Patient and graft survival rates were comparable to the national average. There was no significant difference in post-OLT outcome in patients on MMT when compared with the general population. The few episodes of drug relapse were not related to changes in the methadone dose. Efforts should be made to allow methadone-using cirrhotics better access to OLT without regard to methadone dosage.

Weber-Christian disease is an idiopathic disorder characterized by nonsuppurative nodular panniculitis with a lobular distribution of acute inflammation in the subcutaneous fat with occasional systemic involvement. Although the histopathologic features of the liver disease in the syndrome are characterized by steatohepatitis, the clinical features have not been well defined. We report a case of hepatic Weber-Christian disease and discuss the clinical differences from steatohepatitis due to the more common disorders of obesity and diabetes mellitus.

The monoclonal antibody designated mAb Das-1, which was generated against a colon epithelial protein, reacts with the normal biliary epithelium and keratinocytes, which are among targets of tissue injury in ulcerative colitis. Moreover, mAb Das-1 reacts with abnormal cells in Barrett's esophagus and chronic cystitis profunda, as well as so-called 'oval cells' in the adult liver, which are considered oncogenic progenitor cells. To establish ontogenic regulation of mAb Das-1 reactivity, we studied 7- to 24-week-old human fetuses by immunohistochemistry. In liver, mAb Das-1 reactivity was further correlated with glycogen, dipeptidyl peptidase IV, glucose-6-phosphatase and gamma-glutamyl transpeptidase expression. mAb Das-1 reacted with cells in organs arising from the pharyngeal cleft (thymus), primitive gut (oral cavity, pharynx, lung, esophagus, stomach, biliary tree, pancreas, liver, colon), ureteric bud (renal tubules, collecting duct), mesonephros (kidney, testis), mesoderm (muscle) and elsewhere (skin, adrenal cortex). In distinction from the adult liver, mAb Das-1 staining was more pronounced in hepatoblasts compared with biliary cells. In adult tissues, however, mAb Das-1 reactivity was restricted to the colon, biliary epithelium, keratinocytes, and ciliary body. These data indicated that the mAb Das-1 recognized epitopes in fetal cells of diverse ectodermal, mesodermal and endodermal origin, compatible with sharing of lineage mechanisms in tissues. Reactivation of mAb Das-1 staining in epithelial precancerous conditions, including carcinomas arising in these organs, is compatible with oncofetal regulation of the antigen, which will facilitate analysis of cell subpopulations during organ development, regeneration and oncogenesis., (Copyright 2000 S. Karger AG, Basel)

In understanding mechanisms of liver repopulation with transplanted hepatocytes, we studied the consequences of hepatic polyploidization in the two-thirds partial hepatectomy model of liver regeneration. Liver repopulation studies using genetically marked rodent hepatocytes showed that the number of previously transplanted hepatocytes did not increase in the liver with subsequential partial hepatectomy. In contrast, recipients undergoing partial hepatectomy before cells were transplanted showed proliferation in transplanted hepatocytes, with kinetics of DNA synthesis differing in transplanted and host hepatocytes. Also, partial hepatectomy caused multiple changes in the rat liver, including accumulation of polyploid hepatocytes along with prolonged depletion of diploid hepatocytes, as well as increased senescence-associated beta-galactosidase and p21 expression. Remnant hepatocytes in the partially hepatectomized liver showed increased autofluorescence and cytoplasmic complexity on flow cytometry, which are associated with lipofuscin accumulation during cell aging, and underwent apoptosis more frequently. Moreover, hepatocytes from the partially hepatectomized liver showed attenuated proliferative capacity in cell culture. These findings were compatible with decreased proliferative potential of hepatocytes experiencing partial hepatectomy compared with hepatocytes from the unperturbed liver. Attenuation of proliferative capacity and other changes in hepatocytes experiencing partial hepatectomy offer novel perspectives concerning liver regeneration in the context of cell ploidy.

Objective: E. coli O157:H7 may cause hemorrhagic colitis resembling ischemic colitis. Diagnosis is usually made by finding sorbitol-negative colonies on MacConkey agar that react with O157 and H7 antisera. Most ischemic colitis is idiopathic, but some may be caused by E. coli O157:H7, inasmuch as this organism can produce fibrin thrombi in colon vasculature. The objectives of this study were to determine whether E. coli O157:H7 infection can be diagnosed retrospectively from paraffin blocks of colon sections and whether an association exists between E. coli O157:H7 infection and colonic ischemia., Methods: Paraffin-embedded sections of normal colon (n = 2) and various colitides [ischemic (n = 11), E. coli O157:H7 (n = 2), IBD (n = 8) and pseudomembranous (n = 3)] were used. Sections were deparaffinized, rehydrated, incubated with 3% peroxide in methanol, rinsed, and incubated with peroxidase-labeled antibody isolated from goats immunized with whole E. coli O157:H7. Sections were stained with peroxidase chromagen reagent and counterstained with hematoxylin. Coarse, granular, orange-brown staining was considered positive. To determine the localization of the chromagen deposits, three cases that stained positive, including one of the culture-proved E. coli O157:H7 colitis and two of colonic ischemia, were processed for electron microscopy., Results: Both cases (100%) of E. coli O157:H7 colitis and three of 11 (27.3%) cases of ischemic colitis stained positive by light microscopy. In one culture-proved case, electron microscopy demonstrated staining of bacillary structures; in two cases of colonic ischemia, extensive deposits of chromagen material were present that were associated neither with inflammatory cells nor with bacterial forms., Conclusions: Immunoperoxidase staining of archival sections may be used to diagnose E. coli O157:H7 infection. An etiological role for this organism is possible in some cases of colonic ischemia.

Objective: Elevated blood ammonia is an important pathogenic factor of hepatic encephalopathy. Although colonic bacteria are considered the main source of ammonia, the stomach in subjects with urease-producing Helicobacter pylori (H. pylori) is an alternative site. The objective of this study was to determine whether H. pylori is associated with this complication., Methods: After assessing liver function and portal hypertension, 55 cirrhotics were evaluated for encephalopathy and H. pylori infection. Response to 2 weeks of amoxicillin (2 g/day) and omeprazole (40 mg/day) was then assessed in 17 (13 H. pylori-positive, four H. pylori-negative) encephalopathic subjects., Results: H. pylori infection was more common (67 % vs 33%, p = 0.004) among encephalopathic patients. Additional factors associated with encephalopathy included older age (60.1 +/- 1.5 vs 49.8 +/- 2.4 yr, p = 0.001), lower albumin (3.17 +/- 0.08 vs 3.69 +/- 0.12 g/dl, p = 0.001), higher total bilirubin (2.24 +/- 0.20 vs 1.53 +/- 0.23 mg/dl, p = 0.034), greater ascites score (0.8 +/- 0.1 vs 0.3 +/- 0.1, p = 0.01), greater diuretic score (1.1 +/- 0.1 vs 0.3 +/- 0.1, p = 0.002), and greater modified Child score (6.7 +/- 0.3 vs 5.1 +/- 0.3, p = 0.001). When adjusted for severity of cirrhosis and age, H. pylori continued to demonstrate a statistical association (p = 0.039). After anti-H. pylori therapy, symptomatology in infected encephalopathic patients appeared to improve, whereas noninfected subjects were unaffected., Conclusion: In cirrhotic patients, H. pylori infection is associated with hepatic encephalopathy, especially in younger patients with decompensated liver disease.

Objective: An ideal assay (inexpensive, sensitive, specific, and readily available) for Helicobacter pylori is lacking. Urease activity is an important characteristic of the organism and is employed in the rapid urease and urea breath tests. In this study, we assessed whether a simpler test, namely, measurement of gastric juice urease activity, would provide comparable results., Methods: Gastric juice was analyzed for urea and ammonia in 57 patients evaluated with rapid urease test and histology. Urease activity was assessed by the fraction of urea hydrolyzed to ammonia., Results: Thirty-five subjects were H. pylori positive and 22 were H. pylori negative. Compared with noninfected subjects, H. pylori-positive patients had lower urea levels (0.52 +/- 0.10 vs. 2.77 +/- 0.48 mM, p < 0.01), higher ammonia concentrations (6.59 +/- 1.06 vs. 1.64 +/- 0.25 mM, p < 0.01), and higher gastric urease activity (0.83 +/- 0.03 vs. 0.24 +/- 0.14, p < 0.01). In H. pylori-negative patients, there was a correlation between blood and gastric urea (r = 0.61, p < 0.01). However, in H. pylori-positive patients, no such relationship existed (r = 0.30, p = 0.11). The ratio of gastric to blood urea was lower in infected patients (0.11 +/- 0.02 vs. 0.45+/- 0.04, p < 0.01). The sensitivity and specificity of gastric urease activity for diagnosis of H. pylori were 91% and 100%, respectively, and for the ratio of gastric to blood urea, 89% and 95%, respectively., Conclusion: Gastric juice urease activity is a simple, sensitive, and specific means to detect H. pylori.

In rapidly renewing epithelia, such as skin and gut, as well as hemopoietic cells and stromal fibroblasts, the process of progenitor cell maturation, terminal differentiation and senescence from cells of a fetal phenotype is strikingly similar. To examine hepatocellular maturation, we studied embryonic, suckling and young adult rat liver cells with multiparametric fluorescence activated cell sorting (FACS), after exclusion of hemopoietic, endothelial, Kupffer, and nonviable cells. With maturation, cell granularity and autofluorescence exponentially increased from fetal liver to suckling and adult liver as the proportion of S phase cells progressively declined from 33.8% +/- 1.3% to 4.9% +/- 2.8% and 1.1% +/- 0.6% (P < 0.05), respectively. In liver from fetal and suckling rats, all hepatocytes were mononuclear and contained diploid DNA whereas 21.2% +/- 5.9% hepatocytes in adult liver were binucleated. Analysis of nuclear DNA content in adult hepatocytes demonstrated that 53.3% +/- 3.9% of the nuclei were diploid, 43.6% +/- 3.5% tetraploid and 0.5 +/- 0.6% octaploid. However, in the adult liver, small, mononuclear cells were also present with granularity and autofluorescence comparable to fetal hepatoblasts, as well as glucose-6-phosphatase activity, diploid DNA in 89.0% +/- 2.1% of the nuclei, and with increased granularity in culture. Since general features of terminal cellularity differentiation and senescence include cessation of mitotic activity, polyploidy and accumulation of autofluorescent secondary lysosomes, our data suggest that liver cells too undergo a process of terminal differentiation.

The presence of progenitor or stem cells in the adult liver and their potential roles in oncogenesis are unresolved issues. The study of hepatocyte progenitor cells has been limited by a lack of convenient in vivo systems allowing unequivocal cell localization and demonstration of differentiation into hepatocytes. To develop an in vivo progenitor bioassay, early (E14) fetal Fischer 344 rat hepatoblasts were transplanted into the spleen of syngeneic, weaning rats deficient in dipeptidyl peptidase IV (DPPIV) activity. The donor status of transplanted hepatoblasts was demonstrated by DPPIV expression. Localization of hepatoblasts was facilitated by the use of an ectopic site, as well as weanling recipients, which readily allowed identification of very small numbers of transplanted cells. Fetal rat hepatoblasts were demonstrated to undergo cellular differentiation along the hepatocyte lineage by acquiring glucose-6-phosphatase activity within 5 d of transplantation. A critical review of previous transplantation studies of hepatocyte progenitor cells and the role of the local microenvironment at inducing differentiation indicates that this novel bioassay should facilitate analysis of progenitor cells.

We developed methods for enriching fetal hepatoblasts by combining panning and multiparametric fluorescence-activated cell sorting. In unpurified, dissociated fetal liver cell suspensions of embryonic age day 15, 3.2% +/- 1.3% and 2.5% +/- 0.7% cells expressed albumin and alpha-fetoprotein, respectively. The remainder exhibited a hemopoietic, endothelial or stromal cell phenotype. Cells were panned first with an antibody to red blood cells to remove erythroid cells and then with monoclonal antibodies OX-43/OX-44 to remove hemopoietic and endothelial cells. This procedure eliminated 84% of fetal hepatic cells, with enrichment of the remainder for albumin or alpha-fetoprotein expression (up to sixfold increase). Flow cytometric analysis of unlabeled cells revealed two populations, which differed in granularity and autofluorescence. After panning, fluorescence-activated cell sorting for agranular cells yielded OX-43/44-positive cells that were essentially all hemopoietic precursor cells or OX-43/44-negative cells that were mostly hemopoietic precursor cells, along with 3.0% +/- 0.7% alpha-fetoprotein-positive cells. In contrast, sorting for granular, OX-43/44-negative cells enriched for predominantly alpha-fetoprotein-positive, parenchymal precursor cells (75.1% +/- 4.7%). Multiparametric flow cytometric analysis of the expression of an oval cell antigen, OC.3, which is a bile duct and putative liver stem cell marker, showed that most OC.3-positive cells coexpressed OX-43/OX-44 and morphologically were hemopoietic precursor cells. However, approximately 30% of the OX-43/44-negative, granular cells expressed OC.3. Although the physiological significance of OC.3-positive hepatoblasts remains to be determined, the ability to isolate distinct liver cell populations by means of fluorescence-activated cell sorting should facilitate further studies.(ABSTRACT TRUNCATED AT 250 WORDS)

myo-Inositol uptake and conversion to phosphatidylinositol (PI) was studied in isolated rat hepatocytes. Uptake of myo-[2-3H]-inositol into the trichloroacetic acid (TCA)-soluble fraction showed no evidence of saturation, while incorporation into lipid had an apparent Km of 0.28 mmol/L for external myo-inositol. With 50 mumol/L myo-[2-3H]-inositol, approximately half of the radiolabel was found in lipid at 30 minutes. Glucose and galactose were weak inhibitors, while phlorizin at 1 mmol/L reduced uptake by 50%. Metabolic inhibitors reduced incorporation of myo-[2-3H]-inositol into lipid, but had no effect on uptake. Hepatocytes maintained myo-inositol levels of 0.4 mmol/L for 60 minutes when incubated with 50 mumol/L myo-inositol, but levels increased when incubated with 1 mmol/L myo-inositol. Efflux of label was studied in hepatocytes prelabeled for 20 minutes with myo-[2-3H]-inositol. Loss of label was initially rapid, but had slowed by 20 minutes, with much of the label remaining in the cells. Phlorizin inhibited the loss of myo-[2-3H]-inositol, while increasing myo-inositol concentration in the medium enhanced efflux. The effects of these agents on the rate of efflux was found in lipid rather than in the TCA-soluble myo-inositol fraction. These findings suggest that myo-inositol is compartmentalized within hepatocytes, with a bulk metabolically inert pool and a smaller active pool that equilibrates with extracellular myo-inositol via an energy-independent carrier-mediated mechanism, and is preferentially available for efflux or for synthesis of phosphoinositides.

Rectal mucosal biopsy specimens from 75 human immunodeficiency virus (HIV)-seropositive and 16 HIV-seronegative subjects were examined. The histopathologic changes were correlated with immunoperoxidase staining for UCHL-1 and HIV core protein p24, quantitative p24 enzyme-linked immunosorbent assay (ELISA) assay in homogenized rectal tissue and serum, and a modified Walter Reed clinical stage. Four phases were seen in the HIV-infected subjects: (1) early phase, in Walter Reed stage 1-2 subjects, with nearly normal histology and low p24; (2) inflammatory phase, typically in Walter Reed stage 3-4 subjects, with a superficial lamina propria infiltrate of lymphocytes, plasma cells, and eosinophils with degranulation, abundant UCHL-1 staining, and maximal p24 by both immunoperoxidase staining and ELISA; (3) transitional phase, in many Walter Reed 5 and some Walter Reed 6 subjects, with normal lymphocyte population density but with subtle inflammatory changes; and (4) lymphoid depletion phase, mainly in Walter Reed stage 6 subjects, with decreased lymphocytes but often with endothelial cell activation and apoptosis. These phases presumably result from effective HIV suppression by a relatively intact immune system, followed by maximal HIV infection and lymphocyte activation, then progressive lymphocyte depletion. The inflammation correlated with the presence and amount of HIV in rectal tissue determined by immunohistochemistry and ELISA and was maximal before overt immunodeficiency developed. Intestinal mucosa could be a preferred site of HIV proliferation and T-cell destruction.

We propose that the liver is a stem cell and lineage system with many parallels to lineages in the bone marrow, gut, and epidermis, varying from them only in kinetics. All are organized with three compartments: a slow cycling stem cell compartment with cells expressing a fetal phenotype and responding slowly to injury; an amplification compartment with cells of intermediate phenotype rapidly proliferating in response to regenerative stimuli or acute injuries; and a terminal differentiation compartment in which cells increasingly differentiate and gradually lose their ability to divide. In all systems, both those with slow or rapid kinetics, the various compartments are positioned in a polarized organization, are associated with a gradient in the chemistry of the extracellular matrix, and show lineage-position-dependent growth responses, gene expression, pharmacological and toxicological responses, and reaction to viruses and radiation. In general, known oncogens selectively kill cells in the differentiation compartment inducing chronic regenerative responses of the cells in stem cell and/or amplification compartment. Tumors arise by subsequent transformation of the activated stem cells or early precursor cells. The evidence for a lineage model consists of the data implicating gradients in cell size, ploidy, growth potential, and antigenic and gene expression in the liver parenchyma along the sinusoidal plates. The traditional explanation for this heterogeneity is that it represents adaption of cells to a changing sinusoidal microenvironment dictated by the direction of blood flow. However, we review the extant data and suggest that it more readily supports a lineage model involving a maturation process beginning with stem cells and precursors in the periportal zone and ending with sensescing parenchyma near the central vein. Support for this theory is provided by the studies on phenotypic heterogeneity in liver, investigations into the embryology of the liver, and analyses of the responses of liver to chemical and viral oncogens that induce rapid proliferation of small cells with oval-shaped nuclei, "oval cells," now thought to be closely related to liver stem cells. The lineage model provides clarity and insights into many aspects of liver biology and disease including the limited proliferative ability of in vitro parenchymal cultures, liver regeneration, gene expression, viral infection, hepatocellular carcinogenesis, liver cell transplantation, and aging.

Since the advent of long-term cyclophosphamide therapy, an association between this agent and the subsequent development of bladder neoplasms has been documented. Only six sarcomas have been reported, to our knowledge. This report describes the first case in which a leiomyosarcoma and an invasive transitional cell carcinoma (ie, carcinosarcoma) developed in a patient with non-Hodgkin's lymphoma treated with 240 g of cyclophosphamide over a 6.5-year period.

A 15-year (1973-1988) prospective study was conducted to determine the effectiveness of D-penicillamine (D-pen) in the treatment of rapidly progressive systemic sclerosis (SSc) of recent onset. Sixty-nine consecutive patients fulfilling strict criteria for rapidly progressive diffuse SSc of less than 18 months of duration were enrolled. Sixty received at least 750 mg/day of D-pen for at least 6 months, whereas 9 did not complete 6 months of treatment because of toxicity, noncompliance or death. In 58 of the 60 patients treated for longer than 6 months, there was an arrest in the progression of skin sclerosis followed by regression with softening, increased pliability and reappearance of sweating and hair. In these cases, the extent of sclerotic skin decreased from a maximum of 64.6 +/- 23.1% total body surface to 15.7 +/- 13.2%. In addition, in the group of patients that received D-pen for longer than 6 months, SSc renal disease was uncommon and pulmonary involvement was not progressive. The overall survival in this group was 88.3%. In conclusion, our prospective study showed that the administration of D-pen resulted in significant improvement of skin sclerosis and in prolonged survival of patients with early, rapidly progressive SSc with diffuse cutaneous involvement.

The nature of gastric infiltrates consisting primarily of benign-appearing small lymphocytes is at present a controversial issue. Earlier reports of gastric lymphoma developing in gastric pseudolymphoma and more recent immunohistochemical studies demonstrating monoclonal B-cell populations in pseudolymphoma suggest that at least some cases represent low-grade lymphomas or clonal precursor lesions that may develop into lymphoma. Observations of a small lymphocytic infiltrate arising in the region of a gastric ulcer that lacked definitive morphologic evidence of malignancy (lymphoma) but was clearly a monoclonal B-cell proliferation by immunohistochemical and gene rearrangement studies support the notion that some gastric lymphoproliferative lesions that histologically have been called pseudolymphomas may include one or more clonal lymphoid expansions. A histopathologic/molecular model suggesting a potential pathway for the development of morphologically recognizable lymphoma from benign-appearing small lymphocytic infiltrates is presented, and the concept that for a variety of lymphoid proliferations clonality and malignancy may not be synonymous is discussed.

A new quantitative assay for fibrinogen/fibrin degradation products (FDPs) was clinically evaluated in 123 tertiary-care patients for whom the standard semiquantitative FDP assay had previously been ordered. On the basis of a comprehensive chart review, 24 patients were categorized as having disseminated intravascular coagulation (DIC), 84 were considered not to have had DIC, ten had fibrinolysis (nine of ten streptokinase induced), and five had a complicated coagulopathy whose exact nature could not be determined. The quantitative and semiquantitative FDP values were significantly correlated. However, the FDP level indicative of DIC was lower by the quantitative assay than by the semiquantitative assay, approximately 18 mg/L vs 40 mg/L, respectively. The advantages of the quantitative over the semiquantitative assay included improved precision and ability to closely monitor changes in the severity of the coagulopathy.