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J R Wands

Publications and source records attributed to J R Wands.

At least 199 records · Page 11Linked to original sources
PubMed1984

Serum alpha-fetoprotein levels in human disease: perspective from a highly specific monoclonal radioimmunoassay.

A rapid multisite radioimmunoassay for measurement of human alpha-fetoprotein (AFP) that uses two high-affinity monoclonal antibodies directed against distinct and separate determinants on the protein was developed and designated M-RIA. The sensitivity of the "simultaneous-sandwich" M-RIA is approximately equal to 0.5 ng/ml of serum after a 1-hr incubation period. Serum AFP levels have been measured in 1747 individuals with hepatocellular carcinoma (HCC), acute and chronic hepatitis B virus infection, chronic hepatitis B surface antigen (HBsAg)-carrier states, cirrhosis, other malignant tumors, and normal and disease controls to determine the specificity of the assay. Eighty percent (68/85) of patients with HBsAg-positive HCC had AFP levels of greater than 200 ng/ml (range, 260 to greater than 200,000 ng/ml). In contrast, all 450 normal subjects and 477 chronic HBsAg-positive carriers had levels of less than 20 ng/ml. More importantly, in acute and chronic hepatitis B, cirrhosis, and other malignant tumors and in the remaining disease controls, AFP levels were less than 20 ng/ml in 99.3% of the subjects, the great majority (greater than 96%) being less than 5 ng/ml. Indeed only two of 1635 individuals, one with acute hepatitis and the other with carcinoma of the esophagus had AFP levels of greater than 100 ng/ml. These observations are at variance with previous studies with conventional polyvalent RIAs of AFP levels of greater than 20 ng/ml in approximately equal to 40% of acute and chronic hepatitis and in 30% of cirrhosis. This striking specificity of the M-RIA is probably due in part to recognition of epitopes unique to AFP and suggest that such an assay may be used in the detection, early identification, and monitoring of AFP-producing tumors in high-risk populations.

Antibodies, Monoclonal↗
PubMed1984

Hepatitis B viral antigenic structure: signature analysis by monoclonal radioimmunoassays.

An approach has been developed for the analysis of hepatitis B viral (HBV) antigenic structure that creates numerical "signatures" of HBV strains. This technique employs high-affinity IgM and IgG monoclonal antibodies (anti-HBsAg) directed toward distinct and separate determinants on hepatitis B surface antigen (HBsAg). Such antibodies have been used to develop sensitive and specific radioimmuno-assays for measurement of HBsAg-associated determinants in serum. In performing "signature" analysis separate binding curves for each monoclonal anti-HBsAg are generated by measuring immunoreactivity in serial dilutions of HBsAg-positive serum. Since the HBsAg concentration in serum is unknown, the binding profiles of groups of samples from the same "classic" HBV subtype are aligned by an iterative maximum likelihood procedure to give the numerical signature of that HBV subtype. By using this approach, HBsAg shows far more antigenic heterogeneity than previously recognized by polyvalent anti-HBsAg antibodies. Indeed, there are subgroups within the classic HBsAg subtypes. In addition, the a domain (common to all known subtypes or strains of HBV) has been shown to be multideterminant. Thus, these studies have demonstrated heretofore unrecognized differences in HBV subtypes. This approach also has broader significance for the study of subtle or major antigenic changes among other viral agents since it is not necessary to know the concentration of virus or viral protein in complex protein mixtures.

Antibodies, Monoclonal↗
PubMed1983

Quantitative removal of hepatitis B viral antigens from serum by a monoclonal IgM coupled to a biocompatible solid-phase support.

We covalently linked to regenerated cellulose filters a high-affinity monoclonal IgM produced against epitopes that reside on hepatitis B viral surface antigen (HBsAg). Conditions were established whereby as much as 250 micrograms of anti-HBsAg IgM could be linked to 2-4 mg of regenerated cellulose acetate by using cyanogen bromide and trichloro-s-triazine coupling agents. The immunoreactivity of the monoclonal anti-HBsAg IgM was preserved, and quantitative binding studies with HBsAg suggests that more than one functional binding site on the IgM molecule was operative. The specificity of the monoclonal anti-HBsAg IgM was established by demonstrating that a nonspecific monoclonal IgM (against influenza hemagglutinin), when coupled to the filters under identical conditions, had no effect on removal of HBsAg from serum. Most importantly, the monoclonal anti-HBsAg IgM-coupled filters quantitatively removed low levels of HBsAg from serum; after the third pass through the filter, HBsAg was undetectable in the perfusate. Further, the stability of the covalent bond between the anti-HBsAg IgM and regenerated cellulose acetate was shown by the lack of detectable murine monoclonal anti-HBsAg IgM in filtered serum despite 50 passages through the filter. Thus, we have demonstrated that monoclonal IgM antibodies with predefined specificity, when coupled to a biocompatible solid-phase support, may serve as a high-affinity and specific immunoabsorbant for quantitative removal and recovery of viral antigens from human serum. By using this approach, specific removal and recovery of many other substances from serum or plasma would seem possible.

Antibodies, Monoclonal↗
PubMed1982

Immunotherapy in nude mice of human hepatoma using monoclonal antibodies against hepatitis B virus.

The human hepatoma cell line PLC/PRF/5, which contains integrated hepatitis B virus DNA, synthesises and secretes hepatitis B virus surface antigen (HBsAg). When injected into BALB/c nude mice, these cells produce well-vascularized, encapsulated tumours in almost 100% of animals. HBsAg has been demonstrated on the surface and in the cytoplasm of PLC/PRF/5 cells using immunofluorescence techniques. Recently, we reported that monoclonal antibodies to HBsAg (IgG1, IgG2a and IgM isotypes) bind to HBsAg-associated viral determinants of PLC/PRF/5 cells in culture and immunoprecipitate HBsAg secreted into the growth medium. Also IgG2a and IgM antibodies to HBsAg (anti-HBs) produce specific lysis of PLC/PRF/5 cells in culture in the presence of complement, but have no lytic effect on human hepatoma cells which do not express HBsAg. In the present study, we demonstrate that IgM and IgG2a, but not IgG1, monoclonal anti-HBs specifically prevent or suppress tumour formation in a substantial number of athymic nude mice injected with PLC/PRF/5 cells.

Animals↗
PubMed1982

Demonstration of previously undetected hepatitis B viral determinants in an Australian Aboriginal population by monoclonal anti-hbs antibody radioimmunoassays.

High-affinity IgM and IgG monoclonal antibodies (anti-HBs) against hepatitis B surface antigen (HBsAg) determinants were used to study a confined Australian Aboriginal population, 51% of which showed evidence of exposure to hepatitis B virus (HBV). A conventional radioimmunoassay which uses polyvalent anti-HBs antisera indicated that 4.4% of the subjects were positive for HBsAg; a monoclonal IgM anti-HBs radioimmunoassay detected all these HBsAg-positive samples and showed enhanced binding activity in a further 5.4% of subjects. Detailed analysis of this binding activity in serum by different IgG and IgM monoclonal anti-HBs antibodies demonstrated additional HBsAg-associated determinants as well as remarkable homogeneity of the determinants in this population. It was concluded that there are HBV or HBV-like agents in this community not previously detected by conventional assays.

Adult↗
PubMed1982

Monoclonal radioimmunoassays for hepatitis B surface antigen: demonstration of hepatitis B virus DNA or related sequences in serum and viral epitopes in immune complexes.

High-affinity monoclonal IgM and IgG antibodies (anti-HBs) to hepatitis B surface antigen (HBsAg) have recently been developed and used by us in the construction of highly sensitive radioimmunoassays for the detection of HBsAg-associated determinants in serum. We now report that selected serum samples demonstrating monoclonal immunoreactive material also contain nucleic acid sequences complementary to hepatitis B virus (HBV) DNA by molecular hybridization analysis. In addition, monoclonal radioimmunoassays can detect viral determinants in HBsAg-anti-HBs immune complexes formed in anti-HBs excess; such determinants are undetectable by commercial radioimmunoassay. These and our previous studies suggest that there are HBV or "HBV-related" agents present in human serum that are detected by monoclonal antibodies but are not identified by conventional polyvalent antibodies.

Antibodies, Monoclonal↗
PubMed1982

Selecting binding and complement-mediated lysis of human hepatoma cells (PLC/PRF/5) in culture by monoclonal antibodies to hepatitis B surface antigen.

High-affinity 125I-labelled monoclonal antibodies to hepatitis B virus surface antigen (HBsAg) bind to human hepatocellular carcinoma cell line, PLC/PRF/5, which synthesizes and secretes HBsAg. These monoclonal antibodies of the IgG1, IgG2a, and IgM isotypes are directed against different antigenic determinants on HBsAg and, in the presence of complement, both anti-HBs IgG2a and IgM, but not anti-HBs IgG1, lyse PLC/PRF/5 cells in culture. Although there is a low level of anti-HBs binding (especially with anti-HBs IgM) to human hepatoma cell lines which do not synthesize HBsAg (SK-Hep 1 and Mahlavu cells), this interaction does not lead to complement-mediated cell lysis and is thought to be nonspecific. Minimal binding of 125I-labeled anti-influenza HA antigen IgM binding to PLC/PRF/5 cells was also detected, but this likewise did not lead to complement-mediated cell lysis. These results indicate that a human hepatocellular carcinoma cell line, persistently infected with hepatitis B virus, can be recognized and lysed by monoclonal antibodies directed against specific determinants of HBsAg. Monoclonal antibodies to this viral envelope protein may prove to be useful immunodiagnostic and immunotherapeutic agents when such viral epitopes are expressed on the surface of infected cells.

Animals↗
PubMed1982

Detection and transmission in chimpanzees of hepatitis B virus-related agents formerly designated "non-A, non-B" hepatitis.

Four chimpanzees have been infected with three different inocula containing "non-A, non-B" hepatitis virus(es). After inoculation, serial studies established the presence of antigenemia or viremia (or both) by radioimmunoassay with high-affinity monoclonal antibodies directed toward separate and distinct determinants on hepatitis B surface antigen (HBsAg) and by molecular hybridization analysis using a cloned hepatitis B virus (HBV) DNA probe. In contrast to results observed during HBV infection, elevations in serum alanine aminotransferase values indicate that liver injury preceded antigenemia by several weeks. Thus, the time between inoculation and development of antigenemia (incubation period) varied from 64 to 190 days and, in some cases, single or multiple episodes of antigenemia or viremia occurred in the absence of elevated aminotransferase levels. In this study, two chimpanzees were high-titer positive for antibodies to HBsAg (anti-HBs) from previous infection with HBV, suggesting that the antigenic composition of HBV-related virus(es) is substantially different from that of HBV, since naturally occurring anti-HBs antibodies were not protective. Demonstration of HBV-related virus(es) by the methods used in this study of experimental hepatitis infection in chimpanzees should now permit detection, isolation, and characterization of these previously elusive agents.

Alanine Transaminase↗
PubMed1982

Monoclonal IgM radioimmunoassay for hepatitis B surface antigen: high binding activity in serum that is unreactive with conventional antibodies.

Using a monoclonal IgM antibody (anti-HBs) to hepatitis B surface antigen (HBsAg) in a radioimmunoassay for hepatitis B, we have detected high binding activity in human serum that was unreactive in assays employing conventional anti-HBs reagents. The binding material was isolated from serum by affinity chromatography on monoclonal IgM anti-HBs, and comparison of the material with HBsAg (by sodium dodecyl sulfate/polyacrylamide gel electrophoresis) demonstrated that the two shared several similar polypeptides. Furthermore, comparison of the binding properties of HBsAg and concentrated monoclonal immunoreactive material with conventional and monoclonal anti-HBs reagents demonstrated some antigenic crossreactivity. The molecular weight of the monoclonal immunoreactive material was approximately 2 X 10(6). Immunoprecipitation of the material with monoclonal IgM antibodies and examination by electron microscopy revealed clumped and "spiculated" particles that resembled 22-nm hepatitis B particles coated with the same antibody. Thus, this study suggests that the high-binding-activity material, detected in serum only by the monoclonal radioimmunoassay, is not identical with HBsAg, but it shares some common properties.

Adult↗
PubMed1982

Alterations of T-cell subsets in primary biliary cirrhosis.

To determine whether abnormalities of immunoregulatory T cells are associated with primary biliary cirrhosis, we characterized peripheral blood mononuclear cells in 16 patients with primary biliary cirrhosis and compared them with 30 normal controls. For this analysis we used monoclonal antibodies to the surface antigens on helper/inducer (T4+) and suppressor (T8+) T cell subsets and to a common T cell antigen (T3+). In contrast to normal persons, patients with primary biliary cirrhosis had reduced percentages of T3+ cells. More importantly, there was a relative decrease in helper/inducer (T4+) cells in 9/16 patients and a decrease in suppressor (T8+) cells in 5/16 patients. Furthermore, clinical studies indicated that patients with a decreased suppressor cell population (increased T4+ : T8+ ratio) had more advanced disease, as reflected by serum bilirubin levels (P less than 0.05) and histological changes in the liver (P less than 0.001), than those patients with a reduced helper T cell population (decreased T4+ : T8+ ratio). These data suggest that abnormalities of immune responsiveness in primary biliary cirrhosis may have a more complex origin than a uniform alteration in one immunoregulatory T-cell subset and that these immunoregulatory cell changes vary according to the severity of the disease.

Adult↗
PubMed1982

Experimental murine hepatitis and inducible suppressor cell function.

We have investigated the changes in inducible suppressor activity in spleen cells of young BALB/c mice infected with A-59 strain of murine hepatitis virus. The peak histological and biochemical damage occurred four days after intraperitoneal inoculation of the virus. Before that, on day 2, there was a transient loss of suppressor activity inducible in splenic cells by in vitro incubation with the mitogen Con A. Sequential changes in the proliferative response of spleen cells to Con A also occurred, but did not account for the loss of inducible suppressor activity. This variation in activity of Con A-stimulated suppressor cells suggests an immunoregulatory role for these cells during experimental viral hepatitis.

Animals↗
PubMed1981

Immunodiagnosis of hepatitis B with high-affinity IgM monoclonal antibodies.

High-affinity monoclonal IgG and IgM antibodies to hepatitis B surface antigen (HBsAg) have been prepared and their functional capabilities explored by means of solid-phase radioimmunoassays. 125I-labeled HBsAg binding studies indicated that monoclonal IgM antibodies against HBsAg (anti-HBs) coupled to a solid-phase support quantitatively bound more HbsAg at a faster rate than conventionally prepared anti-HBs reagents or other high-affinity IgG monoclonal anti-HBs antibodies. Consequently, IgM anti-HBs was also radiolabeled, and an IgM-IgM radioimmunoassay was developed for the immunodiagnosis of hepatitis B. The lower limit of this assay was approximately 100 pg +/- 30 (SEM) of HBsAg per ml of serum. Compared to available commercial radioassays, preliminary studies have shown the IgM-IgM assay to have increased sensitivity, which improved the detection of a HBsAg-associated determinant in acute hepatitis and post transfusion hepatitis. It is probable that the multivalent interaction between monoclonal IgM anti-HBs and the polydeterminant HBsAg is important in augmenting the performance of this monoclonal assay.

Animals↗
PubMed1981

High affinity monoclonal antibodies to hepatitis B surface antigen (HBsAg) produced by somatic cell hybrids.

Somatic cell hybrids (hybridomas) have been established which produced antibodies to hepatitis B surface antigen (HBsAg) by immunizing BALB/c/mice with a highly purified preparation of HBsAg and fusing their splenocytes with the myeloma cell line P3-NSI/1-Ag4-1. The route of immunization, interval between primary and secondary immunizations, and immunizing antigen concentration appeared crucial for optimal establishment of the hybrid cell lines. From one cell fusion, described here in detail, we established 47 hybrid cell lines secreting antibody to HBsAg (anti-HBs). The resultant hybrids produced anti-HBs of sufficient affinity and concentration to yield values over 400 times background in a solid-phase radioimmunoassay. Three of the secreting hybrids have been cloned by dilutional techniques. The anti-HBs from such hybrids showed specificity for antigens present on HBsAg subtypes (adw and ayw). Monoclonal anti-HBs antibodies to various antigenic components of HBsAg may lead to refinement in the immunodiagnosis of hepatitis B infection and serve as potent probes in the characterization of this complex particle. Moreover, they offer the potential for the development of highly specific immunoprophylactic reagents.

Animals↗
PubMed1981

In vitro studies of enhanced IgG synthesis in severe alcoholic liver disease.

Elevated serum immunoglobulin levels are a frequent finding in patients with severe alcoholic liver disease. We measured in vitro peripheral blood lymphocyte IgA synthesis by radioimmunoassay in 13 patients with severe alcoholic liver disease and hypergammaglobulinaemia and in normal control subjects. We found an increase in spontaneous IgA synthesis compared to controls (P greater than 0.001). On the other hand, there was no difference between groups in percentage stimulation of IgG production by B cells exposed to pokeweed mitogen. We also searched for defects in concanavalin A (Con A) induced suppressor T cell activity. There was no difference between patients with alcoholic liver disease and controls in the capability of such suppressor T cells to inhibit the response of allogeneic cells to a T cell mitogen. Similarly, we examined the capability of Con A-induced suppressor T cells to inhibit pokeweed mitogen-stimulated IgG synthesis by both autologous and allogeneic responder cells and observed no difference between alcoholic patients and controls. Thus these measured suppressor T-T and T-B cell interactions appeared no different from those in control subjects. Our studies suggest, therefore, that B cell IgG synthesis in vitro is enhanced in alcoholic liver disease. Furthermore, the capability to induce suppressor T cells which affects both T and B cell function appears intact; a finding in contrast to our previous observation in chronic active hepatitis. The investigations suggest that enhanced spontaneous IgG synthesis in vitro may result from intense antigenic stimulation in vivo.

Concanavalin A↗
PubMed1981

Cutaneous vasculitis associated with acute and chronic hepatitis.

We encountered 11 patients who had rashes associated with hepatitis. Five of six acute hepatitis cases, but only one of five chronic hepatitis cases, were related to hepatitis B. Nine of the 11 patients had rash in the absence of clinically overt liver disease. Skin biopsy specimens showed histologic evidence of cutaneous vascular injury; specimens of urticarial and maculopapular rashes, which were seen in this series only with acute hepatitis, showed a primarily lymphocytic venulitis with focal necrosis, while palpable purpura, which was seen in this series only in chronic hepatitis, showed a primarily neutrophilic necrotizing vasculitis involving small vessels. One patient had lichen planus-like lesions. Demonstration of vascular deposits of immunoglobulins, complement, and fibrin in skin, as well as hypocomplementemia, circulating immune complexes, and mixed cryoglobulinemia, in these patients suggests that cutaneous lesions associated with liver disease resulted from immune complex-mediated vascular injury.

Adult↗
PubMed1980

Effect of acute and chronic ethanol intoxication on hepatic regeneration.

We studied the effects of acute and chronic ethanol feeding on hepatic regeneration in rats following partial hepatectomy and toxic liver injury produced by D-galactosamine. Ethanol, when administered as a single dose (6 gm/kg), inhibited 3H-thymidine incorporation into hepatic DNA; this effect depended in part on the time of ethanol feeding following partial hepatectomy. Multiple ethanol feedings produced an even greater inhibition, which persisted for at least 48 hr after partial hepatectomy. Rats chronically fed ethanol for 30 days also failed to achieve a hepatic proliferative response to either partial hepatectomy or D-galactosamine induced hepatitis comparable to isocaloric pair-fed controls. These investigations suggest that there may be a certain metabolic state in the hepatocyte cell cycle which is most susceptible to the action(s) of ethanol; inhibition of liver regeneration by acute or chronic ethanol consumption may result in delayed recovery from prior or coincident liver injury.

Alcoholic Intoxication↗