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Biomedical subjects

K James

Publications and source records attributed to K James.

At least 181 records · Page 10Linked to original sources
PubMed1988

Lymphocyte subsets and macrophages in the male genital tract in health and disease. A monoclonal antibody-based study.

The crucial role of the immune system in the defence against infection and malignancy and its intimate involvement in the pathogenesis of a wide variety of chronic diseases is well established. Although the male genital tract is particularly vulnerable to infection, malignancies and autoimmune disorders which may lead to infertility, our knowledge of the distribution of cells of the immune system in the genital tract is limited. We have therefore investigated this matter using monoclonal antibodies to lymphocyte subsets, macrophages and HLA-DR antigens. These studies have revealed a consistent pattern of distribution of the cells of the immune system within the tissues of the male genital tract. Of special interest were the predominance of the T-suppressor/cytotoxic cells in the lining epithelium of the genital tract, the demonstration of macrophages in testicular tissues and the preferential expression of HLA-DR antigens on the lining epithelium. Profound changes in this pattern were noted in clinical specimens examined. These observations throw light both on normal immune homeostatic mechanisms within the male genital tract and the pathogenicity and aetiology of certain genital tract disorders and highlight the potential value of further studies in this area.

Adult↗
PubMed1988

Human immunodeficiency virus: strategies for protection and therapy.

Never before has so much been learned about the molecular biology of a virus in such a short time since its discovery and yet effective strategies for fighting the human immunodeficiency virus that causes AIDS remain elusive. This review and the accompanying colour centrespread outline some of the options available at the present time. The centrespread illustrates areas within the complex virus infection cycle with potential for therapeutic intervention and lists other possible modes of treatment, while the review below concentrates on the identification and presentation of candidate vaccines and discusses the problems of evaluation that face investigators.

Acquired Immunodeficiency Syndrome↗
PubMed1987

The use of rat mixed-thymocyte culture-conditioned medium for hybridoma production, cloning and revival.

Allogeneic rat mixed-thymocyte 48 h culture-conditioned medium (MTM) was used successfully in place of feeder cells for hybridoma production with the NS-1 and NS-0 plasmacytoma lines. It permitted lower concentrations of fused cells to be seeded, and supported the transition from 96 to 24 well plates. MTM improved the performance of poor sera during cloning. It also assisted the survival of cells that were sensitive to thawing from liquid nitrogen storage, and cells that had inadvertently been allowed to overgrow. Two rats could produce the equivalent of 1500-5000 ml feeder cell suspension according to the dilution used; 150-500 mice would be required to produce such a quantity of cells. Thus use of MTM entailed a considerable saving in mice and provided a secure supply of 'reagent', since a batch could be prepared, checked for sterility, frozen and stored indefinitely.

Animals↗
PubMed1987

Activation of human monocyte tumoricidal activity by C-reactive protein.

We examined the effect of purified human C-reactive protein (CRP) on induction of human peripheral blood monocyte (Mo)-mediated cytotoxicity (CTX) and oxidative metabolism. Exposure of Mo to acute phase serum levels of CRP in vitro resulted in dose-dependent expression of CTX against human tumor cell lines. Nonneoplastic human fibroblasts and glial cells were not affected by CRP-exposed Mo, and treatment of Mo monolayers with anti-Leu 11b (a natural killer marker) and complement did not abrogate or diminish CTX. Tumoricidal activity was observed after 20-44 h of Mo exposure to CRP, and after 48-72 h of coculture with radiolabeled target tumor cells. Mo exposed to CRP for 48 h also demonstrated elevated superoxide anion production when challenged with phorbol myristate acetate. Unlike CTX induced by lipopolysaccharide, CRP-induced CTX was completely inhibited by preincubation of CRP with phosphorylcholine, a CRP ligand, at a concentration of 5.5 molecules phosphorylcholine per molecule CRP. Further, when Mo medium (which contained 5% human AB serum) was preincubated with immobilized CRP, exposure of Mo to CRP in such medium did not result in CTX. In contrast, LPS-induced CTX was not affected. CRP-induced Mo CTX was observed, however, when Mo were exposed to CRP in medium preincubated with phosphorylcholine-treated immobilized CRP, suggesting that an active serum component which complexed with CRP was not removed. These findings indicate that one of the functions of the acute phase protein, CRP, may be to active Mo and that the process may require a CRP-binding serum component.

Astrocytes↗
PubMed1987

The impact of the quality of laboratory staff on the accuracy of laboratory results.

This study tests the premise that laboratories employing medical technologists certified by the Board of Registry of the American Society of Clinical Pathologists (MT[ASCP]) produce more accurate laboratory test results, as measured by the College of American Pathologists proficiency tests. Licensed laboratories in Illinois provided the sample. An accuracy score on the College of American Pathologists proficiency tests was calculated for each laboratory. The accuracy score of a subgroup of laboratories employing all (100%) certified medical technologists was compared with the accuracy score of a subgroup of laboratories employing only noncertified medical technologists. Those laboratories employing only certified medical technologists had a mean accuracy score of 95% (SD = 4%), while laboratories employing only noncertified medical technologists had a mean accuracy score of 75% (SD = 30%). The Mann-Whitney U test was used to identify differences between the two groups of laboratories. A difference in the accuracy scores between the two groups of laboratories was statistically discernible. Since most laboratories employ some certified medical technologists, a second analysis considered the relationship of the proportion of certified medical technologists employed in the laboratory and accuracy on College of American Pathologists proficiency tests. A significant positive Spearman rs correlation confirmed a relationship between employing a higher proportion of certified medical technologists and accuracy of test results.

Certification↗
PubMed1987

Human seminal plasma suppresses lymphocyte responses in vitro in serum-free medium.

The in vitro immunosuppressive properties of human seminal plasma have been re-investigated in serum-free medium in view of recent suggestions that the previously observed effects might be dependent on the presence of exogenous serum co-factors present in the culture media. The present studies reveal that low concentrations of seminal plasma can inhibit the ability of peripheral blood leukocytes to lyse K562 target cells in the absence of fetal calf or new-born calf serum. These inhibitory effects could be achieved by pre-incubating the effector cells in seminal plasma at 37 degrees C prior to use in the natural killer cell assay or by incorporating it into the assay system. Additional studies revealed that human seminal plasma could also inhibit the proliferative response of peripheral blood lymphocytes to phytohaemagglutinin in serum-free HB103 medium. These effects were most marked and consistent if the seminal plasma was present throughout the period of culture. Overall, these studies indicate that the previously reported suppressive effects of human seminal plasma in these systems cannot be entirely attributable to cytotoxic factors generated by exogenous serum components.

Culture Media↗
PubMed1987

Immunocompetent cells in human testis in health and disease.

The authors have investigated lymphocyte subpopulations and macrophages in normal human testes and the testes of patients under investigation and treatment for subfertility. Specific monoclonal antibodies were used in an indirect immunoperoxidase technique. In normal tissues, T lymphocytes (Leu 4-positive cells) were present in the rete testis with a preponderance of cells of the suppressor/cytotoxic phenotype. In contrast, no lymphocytes were detected within the peripheral portions of the testis. Cells reacting with the anti-Leu M3 monoclonal antibody, which defines monocytes/macrophages, were detected in appreciable numbers in peripheral testis with a specific location around the seminiferous tubules. HLA-DR-positive cells (human leukocyte antigens--class II [DR] determinants of the major histocompatibility complex) also were identified and showed a similar pattern of distribution to that of the Leu-M3 positive cells. While no lymphocytes were seen in the normal peripheral testis, T lymphocytes were detected in testicular biopsies from subfertile patients. Suppressor/cytotoxic T cells (Leu 2a-positive) predominated in patients with oligozoospermia and obstructive azoospermia while T cells of the helper/inducer phenotype predominated in patients with unilateral testicular obstruction and in postvasectomy patients. Sperm antibody measurements correlated with these findings.

Adult↗
PubMed1987

Establishing a physician's office laboratory.

Practical approaches to setting up or expanding a physician's office laboratory, either independently or with the assistance of a laboratory consultant, are provided. Ways to assess the issues that may determine the success of an office laboratory are reviewed, including physical features, personnel training, methods or instruments, and the importance of documentation.

Calibration↗
PubMed1987

Pedunculated hepatocellular carcinoma. Is it an entity?

Two cases of pedunculated hepatocellular carcinoma are reported. One of these was known to have been present for 5 years. Both patients are alive 1 and 2 years after surgery though the former has developed a solitary bone metastasis. The literature on 30 previously published cases is reviewed and it is concluded that, minor differences apart, this tumour is not substantially different from hepatocellular carcinomas in general. The slow growth and good prognosis relate to its extrahepatic location which may be explained by an origin from accessory lobes of the liver.

Aged↗
PubMed1987

Local immune responses after intravesical BCG treatment for carcinoma in situ.

The lymphoid cellular infiltrates in the bladder biopsies from patients with carcinoma in situ before and after BCG intravesical therapy have been determined and characterised. This has been achieved using a panel of monoclonal antibody probes in an indirect immunoperoxidase technique. These studies have revealed the predominance of T-cells of the helper/inducer phenotype (T4+), beta-lymphocytes (B1+) and macrophages (Leu M3+, 3.9+) in bladder biopsies after BCG therapy. HLA.DR antigens were also expressed on the lymphoid cells infiltrate as well as the urothelial cells. These results suggest that the components of an active immune response were present and enhanced in the bladder wall after BCG therapy.

Administration, Intravesical↗
PubMed1987

Studies on the immunosuppressive effect of seminal plasma.

In vitro suppression of immune responses by seminal plasma is well documented, but the mechanism by which it exerts its effects remains to be established. Our studies on T-lymphocyte proliferation and natural killer cell target-cell lysis reveal that seminal plasma mediated suppression is dose-dependent and temperature-dependent, and that cells which have been activated are less susceptible to suppression. In the case of mitogen-induced T-cell responses this results in a decrease in the expression of the Interleukin-2 receptor whose generation is essential to T-cell proliferation. These studies provide further evidence about suppression of the immune response by seminal plasma. This may be a contributory factor in the aetiology of AIDS, other sexually transmitted diseases, infertility and malignancies of the urogenital tract including carcinoma of the cervix.

Cell Division↗
PubMed1986

Comparison of radioimmunoassay and immunoradiometric assay for serum prostatic acid phosphatase.

We have compared the laboratory performance of immunoradiometric (IRMA) and radioimmunoassay (RIA) methods developed in this laboratory for measurement of serum prostatic acid phosphatase (PAP). The IRMA utilizes a radiolabelled mouse monoclonal anti-PAP and a solid phased rabbit polyclonal anti-PAP. The same rabbit antibody is used in the RIA. The IRMA shows excellent precision over a much wider working range (0.25-1000 micrograms/l) than the RIA (0.73-14.0 micrograms/l), and can be completed in 5 h, while the RIA requires 3 days. Levels in healthy males and in patients with benign prostatic hypertrophy are similar in both assays, upper limits of normal being 1.8 micrograms/l (IRMA) and 4.7 micrograms/l (RIA). The two assay methods correlate very well (r = 0.97) when PAP is measured in serum from prostatic cancer patients, although IRMA results are generally lower than those obtained by RIA. About 20% of patients with non-metastatic prostatic carcinoma had elevated serum PAP, whereas about 80% of those with metastatic disease had raised levels. The diagnostic efficiencies of the RIA and IRMA appeared similar. The value of the IRMA in follow-up and staging remains to be determined.

Alkaline Phosphatase↗
PubMed1986

The production and characterisation of a panel of ten murine monoclonal antibodies to human procoagulant factor VIII.

A panel of 10 murine monoclonal antibodies to procoagulant FVIII has been developed from the fusion of a single spleen. Balb/c mice were injected with a purified preparation of FVIII: Ag, and antibody production in sera and hybrid culture supernatants was monitored using a specific radiometric screening assay. The antibodies all inhibit FVIII clotting activity in normal plasma, and when immobilised on agarose retain their ability to recognise and bind the FVIII procoagulant protein. Studies on protein A-purified immunoglobulins demonstrate a range of properties within the panel of antibodies with regard to species cross-reactivity, clotting inhibition and immunoadsorption. The panel of antibodies has been used to screen heat-treated FVIII concentrates for the occurrence of heat-induced neoantigens.

Animals↗
PubMed1986

Measurement of human and mouse anti-tetanus antibodies and isotype analysis by ELISA.

A rapid and sensitive enzyme immunoassay (ELISA) was developed for the quantitation of anti-tetanus antibodies. This technique was used to measure antibody levels in the plasma of immunized donors, in human anti-tetanus IgG preparations and in human and mouse hybridomas producing monoclonal antibodies to tetanus toxoid. The assay was capable of detecting antibody levels as low as 5 X 10(-4) IU/ml. By inclusion of an extra step involving antibodies to mouse Ig isotypes, a sandwich enzyme immunoassay (SEI) was developed which permitted determination of the Ig isotype of mouse anti-tetanus antibodies including tetanus-specific mouse monoclonal antibodies. SEI confirmed Protein A-Sepharose fractionation of mouse ascites fluid containing anti-tetanus antibody. The tetanus toxoid-coated plates have a shelf life of at least 1 year.

Animals↗