PubMed HealthSearch

Biomedical subjects

J Lake

Publications and source records attributed to J Lake.

At least 19 recordsLinked to original sources

Liver transplantation for sclerosing cholangitis.

The clinical course of 37 patients who underwent 46 liver transplantations for primary (n = 33) and secondary (n = 4) sclerosing cholangitis was reviewed. The median follow-up was 37 months. The patient and graft survivals for patients with primary sclerosing cholangitis at 1, 2, and 5 years were 96.9%, 91.6%, 87.9%, and 83.1%, 74.2%, 65.2%, respectively. In the patients with primary sclerosing cholangitis (PSC), prior surgery except for simple cholecystectomy was associated with significantly greater operative time and blood loss. No cholangiocarcinoma was identified at the time of transplantation. Human leukocyte antigen typing for PSC patients was heavily weighed toward B8 (58.8%) compared with control (11.8%). Sixty-two percent of patients with PSC also had inflammatory bowel disease. Moderate or severe rejection requiring OKT3, "rescue therapy" with FK506, or retransplantation was relatively higher in patients with inflammatory bowel disease (70%) versus patients without inflammatory bowel disease (36.4%) and a matched control group (37.5%). Progressive inflammatory bowel disease was seen in 6 of 19 patients, with 3 developing cancer and a dysplasia. Two patients in the entire group died of sepsis and 3 of colon cancer (2 recurrent and 1 primary). These data demonstrate that excellent survival results can be achieved in this group of patients. Rejection is frequent and often severe and steroid refractory. Colon cancer represents the most frequent cause of death in PSC patients after liver transplantation and demands constant attention.

Adenocarcinoma

Localization of Saccharomyces cerevisiae ribosomal protein L16 on the surface of 60 S ribosomal subunits by immunoelectron microscopy.

Antibodies raised against a trpE-L16 fusion protein expressed in Escherichia coli were used to examine immunological relatedness between Saccharomyces cerevisiae ribosomal protein L16 and ribosomal proteins from eubacteria, halobacteria, methanogens, eocytes, and other eukaryotes. Homologues of L16 also were identified by searches of sequence data bases. Among the bacterial proteins that are immunologically related and similar in sequence to L16 are ribosomal proteins that bind 5 S rRNA. L16 protein fused near its carboxyl terminus to E. coli beta-galactosidase could assemble into functional yeast 60 S ribosomal subunits. The RPL16A-lacZ gene fusion partially complemented the slow growth or lethality of mutants containing null alleles of one or both RPL16 genes, respectively. L16-beta-galactosidase fusion protein cosedimented with ribosomes and polyribosomes, and remained associated with high salt-washed ribosomes. Monoclonal antibodies against beta-galactosidase were used to map the location of L16-beta-galactosidase on the surface of the 60 S subunit by immunoelectron microscopy. L16 was localized near the top surface of the central protuberance, where the 60 S subunit potentially contacts the 40 S subunit. This is similar to the location of the bacterial homologues of L16 in 50 S ribosomal subunits.

Amino Acid Sequence

Immunogenicity of two recombinant hepatitis B vaccines in older individuals.

PURPOSE: Currently available hepatitis B vaccines are recombinant, yeast-derived preparations given in 10-micrograms or 20-micrograms doses. The optimum dose remains controversial. We sought to assess the relative immunogenicity of two hepatitis B vaccines, given in different doses, in older individuals. PATIENTS AND METHODS: In a multicenter, double-blind, randomized clinical trial, a total of 460 healthy subjects between 39 and 70 years of age were screened and immunized with either Engerix-B 20 micrograms or Recombivax HB 10 micrograms in standard, intramuscular, 3-dose regimens. Of these, 397 subjects were eligible to continue vaccination. Immunogenicity was measured by determination of antibody to hepatitis B surface antigen (anti-HBs). Seroconversion and seroprotection rates, and geometric mean titers of anti-HBs were calculated at 1, 3, 6, and 8 months after the initial dose of vaccine. RESULTS: Seroprotection rates for subjects receiving the 20-micrograms dose of vaccine were slightly, but not significantly, greater than for subjects receiving the 10-micrograms dose, at each time point. However, at 3 months, males receiving the higher dose had significantly higher seroprotection rates than males receiving the lower dose: 63% versus 37% (p < 0.001). At 8 months, geometric mean titers for the group receiving Engerix-B 20 micrograms were significantly greater than that for the group receiving Recombivax HB 10 micrograms: 840 mIU/mL versus 340 mIU/mL (p = 0.001). CONCLUSIONS: Immunization with the 20-micrograms dose of recombinant hepatitis B virus vaccine appeared to result in more rapid development of seroprotective anti-HBs titers in older men and in higher titers of anti-HBs at the completion of vaccination when compared to the 10-micrograms dose. The latter data suggest that the 20-micrograms dose may result in a longer duration of seroprotective anti-HBs titers.

Adult

Hepatitis C--its prevalence in end-stage renal failure patients and clinical course after kidney transplantation.

There is a high incidence of chronic liver disease in end-stage renal failure patients on dialysis. Hepatitis C virus appears responsible for 80% of posttransfusion hepatitis, and up to 80% of sporadic hepatitis and cryptogenic cirrhosis. Anti-HCV antibodies correlate highly with the presence of active infection. The clinical implications of HCV infection in patients undergoing renal transplantation is unknown. Part I: We undertook a descriptive cross-sectional study of all renal failure patients admitted for kidney transplant between 1/84 and 12/88. Pretransplant sera were assayed for anti-HCV using an ELISA. Patients were divided into anti-HCV-positive (study group) and anti-HCV-negative (controls). Part II: A cohort study was performed with both groups followed from the time of transplantation to the present. Comparisons were made by t tests, chi-square analysis with Yates correction, Mann Whitney test for nonparametric results and multiple regression analysis. Part I: Anti-HCV was present in 76 of 716 sera assayed. There were no differences in sex, age, number of previous transplants, and underlying renal disease. Four variables predicted the presence of anti-HCV: number of blood transfusions; duration on dialysis; i.v. drug abuse, and nonwhite race. Part II: A group of 596 patients was further analyzed. The mean duration of follow-up was not different between the two groups. There were no differences in graft survival, overall mortality, or mortality secondary to liver disease or sepsis. Based on these results, the presence of anti-HCV should not be a contraindication for kidney transplantation.

Adolescent

Use of Prograf (FK 506) as rescue therapy for refractory rejection after liver transplantation. US Multicenter FK 506 Liver Study Group.

This report describes the clinical characteristics and demographics of patients enrolled into this rescue trial for patients experiencing refractory rejection after liver transplantation. Actuarial graft and patient survival at 12 months postconversion was 50% and 72%, respectively. Actual treatment success at 3 months postconversion was 70%. Karnofsky scores and liver function tests were significantly improved for patients continuing on therapy indicating clinical benefit in these patients. The safety profile of FK 506 is acceptable for such a high-risk group of patients. These preliminary clinical results support the conclusion that FK 506 can effectively control and reverse refractory rejection in a majority of liver transplantation patients.

Acute Disease

Hepatitis B virus and apparent fulminant non-A, non-B hepatitis.

While there is evidence that hepatitis C virus (HCV) does not cause fulminant non-A, non-B hepatitis, the causal agent remains unknown. To evaluate the role of hepatitis B virus (HBV) in this disease, we used a two-step polymerase chain reaction (PCR) to amplify the surface and core regions of HBV DNA in serum and liver samples taken prospectively from twenty-six patients (mean age 36 years, range 1 to 64) with acute hepatic failure undergoing liver transplantation. HBV DNA was absent from the serum of all patients before transplantation. Seventeen patients were diagnosed as having non-A, non-B hepatitis because they lacked serological evidence of hepatitis A virus or HBV infection. Liver samples were taken from twelve of these patients, and six samples were positive for HBV DNA. By contrast HBV DNA was not detected in liver from three patients with acute liver failure caused by hepatitis A or toxins. HCV RNA was not found in pretransplant samples by PCR. Four of the six patients with detectable HBV DNA in liver and presumptive non-A, non-B hepatitis had detectable HBV DNA in serum after transplantation. One additional patient who did not donate pretransplant liver had HBV DNA in a post-transplant serum sample. Thus, HBV DNA was present before or after transplantation in seven of seventeen patients with apparent non-A, non-B hepatitis. Three of five patients with detectable post-transplant serum HBV DNA were serologically positive for HBV surface antigen. These findings indicate that HBV may be a common cause of fulminant hepatic failure in patients lacking serological evidence of HBV infection.

Acute Disease

Hepatitis C viral infection in liver transplant recipients.

In this study we examined multiple serial liver biopsy specimens from liver transplant recipients to determine the pathological features of hepatitis C virus-induced hepatitis. Hepatitis C virus infections acquired after transplantation and previous infections that recurred in patients after transplantation were confirmed by the results of the polymerase chain reaction. Of 43 patients infected with the hepatitis C virus, 18 had a mild form of chronic hepatitis. Four patients had hepatitis that progressed to focal bridging fibrosis or cirrhosis. There were no significant clinical or pathological differences between infections acquired after transplantation and recurrent infections (as determined by polymerase chain reaction) except that acquired infections more often developed into hepatitis. Findings indicative of hepatitis C infection included portal and parenchymal mononuclear infiltrates of varying degrees, acidophilic necrosis and swollen hepatocytes. Other common findings included lymphoid aggregates, bile duct damage and fatty change. Atypical pathological conditions included extensive hepatocyte swelling or acidophilic necrosis with minimal inflammation mimicking ischemia and ductal or ductular damage and proliferation with mixed portal infiltrates mimicking rejection or obstruction. We conclude that in transplant recipients infection by the hepatitis C virus usually produces a mild disease state, but the diagnosis of hepatitis can be difficult to make because indicators of hepatitis may mimic those of rejection, ischemia, obstruction or other hepatic infections. Serial biopsy specimens with persistent pathology and polymerase chain reaction may be necessary to define the presence of a hepatitis C virus lesion.

Bile Ducts

Incidence and diagnostic features of macroregenerative nodules vs. small hepatocellular carcinoma in cirrhotic livers.

In Japan, the presence of a large regenerative nodule within a cirrhotic liver, referred to as a macroregenerative nodule or adenomatous hyperplasia, is thought to play a role in the pathogenesis of hepatocellular carcinoma. These lesions, however, have received little attention outside of Japan. We examined 110 sequentially explanted cirrhotic livers for the presence of such nodules. By gross examination, 19 livers (17.3%) had 40 nodules (10 livers had more than one nodule) between 0.8 and 3.5 cm in diameter. By histological examination, 28 of these were macroregenerative nodules and 12 were hepatocellular carcinomas. Three of these hepatocellular carcinomas, however, appeared to have arisen in association with a macroregenerative nodule. We found that the architectural features of thickened cell plates, formation of trabeculae and loss of reticulin were usually very helpful in differentiating benign macroregenerative nodules from hepatocellular carcinoma. The incidence of macroregenerative nodules in our series was similar to that seen in the Japanese studies, and although we feel that they may play a role in the pathogenesis of carcinoma, we do not believe their presence is necessary for the development of hepatocellular carcinoma.

Adenoma

Intragraft cytokine profile during human liver allograft rejection.

Forty-three human liver allograft biopsies and normal liver were directly analyzed for inflammatory and immunoregulatory cytokine gene expression by polymerase chain reaction (PCR). IL-5 gene expression was predominantly present in biopsies from liver allografts with histopathological evidence of acute rejection. IL-2 gene expression was rarely observed in rejecting allografts or allografts without evidence of rejection. In contrast, IL-4 message was readily detectable in the majority of liver allografts regardless of clinical status. The inflammatory mediators IL-1 beta, TNF-alpha, and IL-6 were detected with similar frequency in rejecting allografts and allografts without evidence of rejection. These findings suggest that inflammatory and immunoregulatory cytokines are produced within the allograft. Moreover, IL-5 may play a role in the local mechanisms of liver allograft rejection.

Base Sequence

Hepatitis C in patients undergoing liver transplantation.

OBJECTIVE: To determine the prevalence of antibodies to hepatitis C virus (anti-HCV) among patients undergoing liver transplantation and the relation between anti-HCV and post-transplant hepatitis. DESIGN: Retrospective cohort. PATIENTS: Serum samples from 128 patients who underwent liver transplantation. Sixty-six patients who had 6 months of follow-up and for whom both pretransplant and post-transplant serum samples were available were included in a study to asses the relation between anti-HCV and post-transplant hepatitis. MEASUREMENTS: Sera were tested for anti-HCV using an enzyme-linked immunosorbent assay (ELISA) and, if positive, two confirmatory tests were done. Patients had a biopsy every week until two specimens showed no abnormal findings. MAIN RESULTS: Only patients with chronic non-A, non-B hepatitis (15 of 30; 50%), alcoholic cirrhosis (7 of 19; 37%), and chronic hepatitis B infection (3 of 11; 27%) were anti-HCV positive. No patient with another form of chronic liver disease or with acute liver failure due to non-A, non-B hepatitis was anti-HCV positive. After transplantation, loss of anti-HCV was frequent and acquisition rare. Hepatitis developed in the graft in 17% of patients, but the incidence was similar among anti-HCV negative and anti-HCV-positive patients. CONCLUSIONS: Hepatitis C virus is a common cause of chronic liver disease in patients requiring liver transplantation, but anti-HCV is rarely found in patients with acute liver failure. Previous HCV infection, based on detection of anti-HCV, is not an independent risk factor for post-transplant hepatitis.

Cohort Studies

Azathioprine hepatotoxicity after liver transplantation.

We report the first two cases of apparent azathioprine hepatotoxicity occurring after liver transplantation. The two patients exhibited jaundice, elevated serum transaminase activities and histopathological features of sinusoidal congestion and centrilobular hepatocellular degeneration 17 and 61 days after transplantation. After withdrawal of azathioprine, liver test results improved immediately in both patients. Recurrence of liver injury after another challenge with azathioprine was seen in the first case. Previously, fatal venoocclusive disease occurring after kidney transplantation had been attributed to azathioprine. Irreversible venoocclusive disease and the reversible hepatotoxicity described in this report (i.e., sinusoidal congestion with centrizonal necrosis) most likely represent different stages of hepatic endotheliitis caused by azathioprine. Thus early diagnosis of azathioprine hepatotoxicity is of great importance.

Adult

Hepatitis C in liver transplant recipients.

HCV infection is commonly found in patients with chronic liver disease undergoing liver transplantation. However, the presence of antibody to HCV does not appear to be associated with the development of hepatitis posttransplant. No other risk factors were identified that appear to predispose patients to development of hepatitis in the posttransplant period, including amount of blood product exposure. The role of immunosuppression in the acquisition and expression of liver disease caused by HCV remains to be determined.

Hepacivirus