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Biomedical subjects

J B Zeldis

Publications and source records attributed to J B Zeldis.

At least 37 records · Page 2Linked to original sources
PubMed1993

Infection of a leukemic cell line (K562) by hepatitis B virus induces cell growth inhibition.

Hepatitis B virus inhibits the in vitro growth of the human leukemic cell line K562; however, the mechanism of this growth inhibition is not understood. One to 12 days after exposure, viral DNA and RNA were detected in K562 cells by Southern blot and reverse-transcriptase polymerase chain reaction analyses. Virus-containing serum that was heat-inactivated failed to inhibit cell growth and no viral DNA or RNA was detected in these cells. In addition, murine monoclonal antibodies directed to hepatitis B virus surface epitopes neutralized the virus-induced growth inhibition whereas antibodies to hepatitis B virus core epitopes failed to suppress the inhibition. These results indicate that in vitro infection of K562 cells by hepatitis B virus causes inhibition of hematopoietic cell line growth.

Antibodies, Monoclonal↗
PubMed1993

Significance of antibody to hepatitis B core antigen in blood donors as determined by their serologic response to hepatitis B vaccine.

Because large numbers of volunteer blood donors may be disqualified for "false-positive" results on tests for antibody to hepatitis B core antigen (anti-HBc), a more specific definition of anti-HBc enzyme immunoassay (EIA)-reactive was evaluated, including only those donor samples that were "strongly" reactive (sample-to-cutoff absorbance ratio, < 0.45). Results using this definition and other anti-HBc test methods were compared to the serologic response (antibody to hepatitis B surface antigen [anti-HBsAg]) to hepatitis B vaccination. Fifty-eight volunteer blood donors who had previously been deferred as donors, because of reactive anti-HBc tests (all other blood screening tests were negative, including those for HBsAg and anti-HBsAg) on two occasions, were vaccinated for hepatitis B. It was assumed that an anamnestic response to vaccine indicated past infection with hepatitis B, while a primary response to vaccine indicated lack of past infection. One (2%) of 43 donors with a historically "weak" anti-HBc (reactive absorbance ratio, > or = 0.45) had an anamnestic response to vaccine, compared to 8 (53%) of 15 with historically "strong" anti-HBc (reactive absorbance ratio, < 0.45) (p < 0.005). Anti-HBc testing using the microparticle EIA method also correlated well with hepatitis B vaccination results. The use of a narrower definition of "reactive" for anti-HBc EIA testing yielded much more specific, but slightly less sensitive, results.

Blood Donors↗
PubMed1993

Variation in antibody reactivity to the hepatitis C virus by comparative immunoscreening and enzyme immunoassay.

The detection of antibody to the hepatitis C virus C100-3 antigen from the nonstructural region (NS3/NS4) of the viral genome was the first useful marker developed to detect past or potentially active infection with the hepatitis C virus. A systematic epitope survey of the nonstructural region has uncovered other immunogenic antigens. In order to assess the possible diagnostic utility of these antigens, their reactivity against a limited panel of sera from patients with chronic liver disease due to hepatitis C virus and other etiologies was tested. Antibody assays were performed using an immunoblot plaque assay and an enzyme-linked immunosorbent assay (ELISA). In a study of 16 C100-3-reactive individuals, all 16 patients were reactive using the plaque assay for the NS3 3' (409-1-1) and NS3 5' (C33u). In this same group of patients, antibodies by ELISA were reactive to NS3 3' in 12 of 16 patients (75%), NS3 5' in 15 of 16 patients (93%), and a capsid antigen (NC450) in 14 of 16 patients. In a group of five patients who were diagnosed with cryptogenic liver disease (C100-3 negative), 4 of 5 patients were reactive for antibody to all of the above epitopes. In a survey of 23 patients with other forms of chronic liver disease (nonviral liver disease, hepatitis B, alcoholic liver disease, cholestatic liver disease, and autoimmune hepatitis), only 1 of 23 patients was reactive for antibody to the C100-3 and 4 of 23 patients were reactive for antibodies to structural and nonstructural regions of the virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Polymerase chain reaction in gastroenterology.

Polymerase chain reaction (PCR) has had a major impact on molecular biology and is beginning to change our perception of certain disease processes and diagnostic tests. PCR allows the identification and amplification of very rare nucleic acid sequences. This is resulting in our identification of previously elusive infectious agents and of mutations that may affect the course of viral infections or carcinogenesis. PCR can now analyze the expression of genes from single cells or single molecules of nucleic acid from a sample source. Once pitfalls in contamination are overcome and more probes for genes of biological and medical interest become available, PCR technology will become universally employed in the clinical laboratory.

Colonic Neoplasms↗
PubMed1993

Hepatitis C virus in blood samples from volunteer donors.

The specificities of four assays for hepatitis C virus (HCV) were compared by using units from volunteer blood donors. Upon Food and Drug Administration licensure of the first immunoassay for anti-HCV, EIA-1, units previously deemed acceptable for transfusion and all subsequent blood donations were screened. EIA-1 repeat-reactive (RR) units were tested for HCV by a second-generation enzyme-linked immunoassay (EIA-2) and by a four-antigen recombinant immunoblot assay (RIBA II) and for HCV RNA by reverse transcriptase polymerase chain reaction. All HCV RNA-positive samples were reactive by both RIBA II and EIA-2. All RIBA II-reactive sera were EIA-2 RR. In EIA-1, 0.45% of the prescreened units and 0.59% of the prospectively screened donors were RR. Of these, 52.5 and 54%, respectively, were EIA-2 RR, 71.4 and 69% of the EIA-2 RR units were reactive on RIBA II, and 93 and 88% of the RIBA II-reactive samples were HCV RNA positive. When the sample/cutoff ratio for EIA-2 was greater than 5, 91% of the samples were RIBA II reactive and 82% of the samples were HCV RNA positive. None of EIA-2 RR units with a sample/cutoff ratio of < 5 was RIBA II reactive or HCV RNA positive. In conclusion, RIBA II and RT PCR results are highly concordant. A sample/cutoff ratio of > 5 in EIA-2 is a good discriminator for the likelihood of a true HCV infection on the basis of RT PCR and RIBA II assays.

Base Sequence↗
PubMed1993

Peripheral-blood mononuclear cell responses to recombinant hepatitis C virus antigens in patients with chronic hepatitis C.

Peripheral blood mononuclear cell proliferative responses in vitro to recombinant yeast or Escherichia coli hepatitis C virus fusion proteins were evaluated in 20 patients with chronic hepatitis C who were reactive for antibody to hepatitis C virus (on enzyme immunoassay, version 2.0, and a four-antigen recombinant immunoblot assay). Twenty age-matched, healthy individuals negative for antibody to hepatitis C virus were used as a control group. Peripheral-blood mononuclear cells from all chronic hepatitis C patients with antibodies to hepatitis C virus antigens c22 and c100-3 proliferated in vitro in response to the corresponding recombinant hepatitis C virus fusion protein. Peripheral-blood mononuclear cells from 75% of patients infected with hepatitis C virus proliferated in response to cytidine monophosphate-keto-3-deoxyoctulosonic acid-core recombinant antigen but there was no proliferative response to cytidine monophosphate-keto-3-deoxyoctulosonic acid-EF (derived from the NS5 region). All hepatitis C virus-infected patients had 33c antibody, but peripheral-blood mononuclear cells from only 9 of 14 (64%) proliferated in vitro in response to 33c. Ninety-five percent of all hepatitis C virus-infected patients had peripheral-blood mononuclear cells that proliferated in response to at least one recombinant hepatitis C virus fusion protein. The numbers and percentages of CD3 T cells, CD19 B cells and natural killer cells from patients with chronic hepatitis C virus infection did not differ from those in the healthy control group. However, the number of non-major histocompatibility complex-restricted cytotoxic T cells (CD3-positive, CD56-positive, CD16-positive) was increased in patients with chronic hepatitis C virus infection (p < 0.05).

Adult↗
PubMed1993

Molecular biology of viral hepatitis and hepatocellular carcinoma.

Five viruses are the major causes of hepatitis. These viruses are totally unrelated to each other in structure and mode of replication despite the similarity in the acute syndrome produced by each virus. HAV is a single-stranded RNA virus that has a very stable capsid and whose proteins are derived from a single polyprotein. HBV is a DNA virus that replicates through an RNA intermediate. HCV is a labile single-stranded RNA virus whose proteins are derived from a polyprotein. HDV is a defective RNA virus related to viroids that encodes a capsid antigen, delta antigen, and requires the envelope protein of HBV (HBsAg) for its propagation. HEV is a labile RNA virus that is unrelated to other known viruses. Hepatitis B, C, and D can cause chronic hepatitis. Both chronic hepatitis B and C virus infections are associated with primary hepatocellular carcinoma. The most likely mechanism for hepatitis B and C promotion of primary hepatocellular carcinoma in that these viruses cause chronic inflammation and increased mitotic activity of the pluripotent oval cells of the liver. Most likely, primary hepatocellular carcinoma arises out of synergy between chronic viral infection and some other carcinogenic stimulus such as exposure to a hepatotoxin.

Carcinoma, Hepatocellular↗
PubMed1992

Detection of acute hepatitis C virus infection by ELISA using a synthetic peptide comprising a structural epitope.

An enzyme-linked immunosorbent assay (ELISA) was developed by using a synthetic polypeptide (SP) whose sequence was derived from the structural region of hepatitis C virus (HCV). Results of several coded panels of sera obtained from volunteer blood donors and patients with apparent non-A, non-B hepatitis and/or hepatitis B virus used in this ELISA were compared with those of a commercially available first-generation C-100 ELISA (using nonstructural HCV antigens), an experimental second-generation C-200/C-22 ELISA (using both structural and nonstructural HCV antigens), and recombinant immunoblot assays RIBA-I and RIBA-II. In the majority of cases, the results obtained with the HCV-SP ELISA correlated well with those obtained by RIBA-II and C-200/C-22 ELISA. In contrast, many samples that were repeatedly reactive in the C-100 ELISA results were nonreactive with RIBA and HCV-SP ELISA. In addition, HCV-SP detected HCV-specific antibody that appeared within a month of infection and coincided with the earliest increase in alanine aminotransferase. In summary, we have developed an ELISA based on a structural HCV synthetic polypeptide, HCV-SP, that has high specificity and sensitivity and is capable of detecting specific antibodies in the acute phase of HCV infection.

Acute Disease↗
PubMed1992

Chronic hepatitis B virus infection in an anti-HBc-nonreactive blood donor: variant virus or defective immune response?

Viral sequence and host immune response were investigated in an unusual, asymptomatic chronic hepatitis B virus carrier (human leukocyte antigen type A24, Bw61, Bw62, Bw6, DRw11, DRw52, DQw7) who was consistently nonreactive for antibody to HBc and had a normal ALT level over a 5-yr study period. The precore and core region DNA sequences of virus isolated from his serum had seven silent mutations that resulted in no changes in the amino acid sequence of the adr HBsAg subtype. He had no abnormalities in the number of peripheral blood T or B cells and no HBcAg-specific suppressor T cells. His lymphocytes proliferated in vitro in response to phytohemagglutinin, pokeweed mitogen, Staphylococcus aureus and tetanus toxoid but not to recombinant HBcAg. Unlike other HBsAg carriers and hepatitis B virus-immune individuals, his monocytes did not ingest beads coated with HBcAg. Failure to produce antibody to HBc was not due to an hepatitis B virus variant but to a selective immune system defect in this asymptomatic HBsAg carrier.

Amino Acid Sequence↗
PubMed1992

Hepatitis C virus is detected in a monocyte/macrophage subpopulation of peripheral blood mononuclear cells of infected patients.

Hepatitis C virus (HCV) is the primary agent of posttransfusion non-A, non-B hepatitis. HCV RNA was detected in peripheral blood mononuclear cells (PBMC) by polymerase chain reaction in 17 of 24 HCV-infected patients with chronic hepatitis with or without cirrhosis. One of 5 patients whose PBMC contained HCV RNA also had negative-stranded HCV RNA in the PBMC. In 3 of 11 patients whose PBMC contained HCV RNA, flow cytometry with a murine monoclonal antibody to HCV core epitope revealed cytoplasmic staining of peripheral blood monocytes. The monocyte surface and the peripheral blood lymphocytes did not stain for HCV core epitopes. No correlation could be made between the presence of HCV RNA or antigen in PBMC and any serologic markers of HCV infection. These results indicate that monocyte uptake of HCV by either phagocytosis or infection may be part of the pathophysiology of this chronic disease.

Adult↗
PubMed1992

Seroepidemiology of viral infections among intravenous drug users in northern California.

Intravenous drug users are frequently exposed to parenterally transmitted viral infections, and these infections can spread to the general population through sexual activity. We investigated the prevalence of serologic markers for human immunodeficiency virus type 1 (HIV-1), human T-cell lymphotropic virus type I/II (HTLV-I/II), hepatitis B virus (HBV), and hepatitis C virus (HCV) in intravenous drug users and their sexual contacts. Of 585 drug users from northern California tested for these serologic markers, 72% were reactive for the antibody to HCV, 71% for the antibody to hepatitis B core antigen, 12% for HTLV-I/II antibodies, and 1% for the HIV-1 antibody. The prevalence of serologic markers for these four viruses correlated with the duration of intravenous drug use, the ethnic group, and the drug of choice. More than 85% of subjects infected with either HCV or HBV were coinfected with the other virus. All persons reactive to HTLV-I/II antibodies had antibodies for either HBV or HCV. Of 81 sexual contacts tested, 17% had evidence of HBV infection while only 6% were reactive for HTLV-I/II antibodies and 4% for the antibody to HCV. None of this group was infected with HIV-1. We conclude that HTLV-I/II and HCV are inefficiently transmitted to sexual contacts while HBV is spread more readily. Programs designed to discourage the sharing of drug paraphernalia, such as needle and syringe exchanges, should decrease the risk of parenterally spread viral infections in intravenous drug users and thus slow the spread of these infections to the general population.

Adult↗
PubMed1991

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↗
PubMed1991

Prevalence of hepatitis C virus antibodies among patients infected with human immunodeficiency virus.

A study was undertaken to determine the prevalence and risk factors for serological evidence of hepatitis C virus (HCV) infection in patients infected with the human immunodeficiency virus (HIV). Tests for anti-HCV antibody were carried out by enzyme-linked immunoassay (EIA) on 101 HIV-infected patients from two university-based outpatient clinics. Anti-HCV antibody reactive samples were tested by using a recombinant immunoblot assay (RIBA) for HCV antibodies. Fourteen of 101 (13.9%) HIV-infected patients were anti-HCV reactive by EIA. Of these 14, only seven were reactive by RIBA: four were intravenous drug users as a sole risk factor for HIV infection; and the remaining three acquired HIV by blood transfusion, contaminated instrument exposure or IV drug use and sexual contact. Acquisition of HIV by sexual activity alone was not associated with HCV infection. It is concluded that HCV infection is found in approximately 7% of a university HIV clinic population. False-positive anti-HCV antibody serology may lead to overestimation of the prevalence of HCV infection. Female sex and intravenous drug use are significantly associated with HCV infection among HIV-infected individuals.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Serologic and DNA follow-up data from HBsAg-positive patients treated with orthotopic liver transplantation.

Fifteen hepatitis B surface antigen (HBsAg) positive patients treated with orthotopic liver transplantation were studied to determine whether any clinical, serologic, or histologic data were predictive for recurrent hepatitis B infection leading to graft failure. Six patients died early, one due to primary graft nonfunction and the remaining five due to septic complications. There were nine patients surviving longer than two months, eight of whom are alive at a mean follow-up of 556 days. HBsAg and hepatitis B core antibody (anti-HBc) reappeared in the sera of all survivors after a variable transient period of clearance. One patient died 3 months posttransplant of fungal sepsis and was found to have histologic evidence for recurrent hepatitis and positive immunoperoxidase staining postmortem. The remaining eight survivors are home and clinically well, with no histologic evidence of hepatitis. Seven of these eight patients have hepatitis B viral DNA in their sera. We conclude that while there is a high early mortality, usually from sepsis, none of the serologic, histologic, or DNA data analyzed can be used to predict graft loss from recurrent hepatitis. No grafts have been lost due to recurrent hepatitis B in this series, and therefore we believe that HBsAg positive patients should not be excluded from transplantation.

Adult↗
PubMed1991

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↗
PubMed1990

In vitro inhibition of hemopoietic cell line growth by hepatitis B virus.

The effects of hepatitis B virus (HBV) on established human cell lines of various tissue origins were evaluated by clonal or colorimetric assays in methylcellulose culture. HBV exposure inhibited the growth of six hemopoietic cell lines, while similar incubation did not affect the growth of seven nonhemopoietic carcinoma cell lines of breast, colon, liver, and stomach origin. The inhibition of hemopoietic cell line colony formation was dependent on the presence of intact viral (Dane) particles and the ratio of exposure of virions to cells and was reversible with antibodies to pre-S1, pre-S2, and S envelope protein epitopes. Purified HBV DNA, surface antigen pre-S antigens, and core antigen did not inhibit cell line growth. These results further demonstrate the tropism of HBV for cells of hemopoietic origin, confirming our previous findings on the effects of HBV on the growth of normal bone marrow progenitor cells in vitro. Established human tissue culture cell lines may be used to study the interactions of hemopoietic cells with HBV.

Cell Division↗