Biomedical subjects

K James

Publications and source records attributed to K James.

At least 19 recordsLinked to original sources

PubMed1992

Expression of interferon-gamma receptors on bladder cancer cells: does it correlate with biological response?

Previously we have shown a differential biological response of three human bladder cancer cell lines (RT4, RT112 and MGH-U1) to gamma interferon (IFN-gamma). The present study examines the relationship between the biological response and the expression of the interferon-gamma receptor on the tumour cell surface. Using a competitive radioligand binding assay and Scatchard analysis, we measured the number and affinity of the IFN-gamma receptors on each of the above cell lines. Individual cells from each line expressed large numbers (29,100-41,800) of high-affinity receptors (kd = 2.4-3.9 x 10(10) M). There was no statistically significant difference in either of these parameters between the three lines. We therefore conclude that the biological response of these bladder lines to IFN-gamma does not relate to the number or affinity of its receptor on the plasma membrane of these tumour cells.

Carcinoma, Transitional Cell↗

PubMed1992

Retained mucosa after double-stapled ileal reservoir and ileoanal anastomosis.

A study was undertaken to assess the incidence of inflammation and dysplasia in retained mucosa after double-stapled ileoanal reservoir (IAR) for mucosal ulcerative colitis (MUC). Between September 1988 and February 1992, 56 patients with MUC underwent an IAR. Forty-five patients had a double-stapled IAR (DS-IAR), seven patients had a transanal pursestring stapled IAR (PS-IAR), and four patients had a PS-IAR with mucosectomy. Distal donuts obtained from the stapled IAR were submitted for pathologic review in 55 patients. Nine patients had only small bowel, connective tissue, and/or muscle noted on review. Mucosa was qualified as squamous epithelium (SE), transitional epithelium (TE), or columnar epithelium (CE). All samples were examined for evidence of inflammation and dysplasia. Four patients had SE only, one patient had TE, and 18 had CE. In addition, three patients had SE and CE, seven patients had SE and TE, two patients had CE and TE, and nine patients had all three types. The distance from the dentate line to the anastomosis ranged from 0 to 2.5 cm (mean, 1 cm). In 19 patients (35 percent), the distal donut revealed MUC. Of these 19 patients, six had persistent MUC (43 percent) at the time of subsequent biopsy. An additional four patients had MUC evident on follow-up biopsy but not on distal donuts; two of these four patients had no mucosa in their distal donuts. Only one of the patients with evidence of MUC on donuts and/or biopsy experienced any symptoms referable to active MUC (1.8 percent). None of the specimens examined had any evidence of dysplasia. In 31 patients, no MUC was present in the initial donuts or follow-up biopsies. Although the double-stapled technique appears safe, periodic monitoring is suggested.

Adolescent↗

PubMed1992

Relative immunosuppressive activity of human seminal prostaglandins.

Human seminal plasma contains uniquely high concentrations of prostaglandins of the E series which are believed to contribute to its immunosuppressive effects in vivo. In order to obtain further insight into their activity we have compared the immunosuppressive properties in vitro of PGE1, PGE2 and 19-OH PGE using three immunological systems known to be modulated by prostaglandins, namely, mitogen induced lymphocyte proliferation, IL-2 and transferrin receptor expression and NK-cell mediated cytotoxicity. These studies revealed that PGE1 and PGE2 exerted a greater immunosuppressive effect than 19-OH PGE, but considerably higher levels of 19-OH PGE in semen might contribute the majority of immunosuppressive activity in vivo. Our studies also show that the lower stability of 19-OH PGE in culture media may be responsible for its lower immunosuppressive effect observed in vitro.

Alprostadil↗

PubMed1992

Preliminary studies on the interaction of TNF alpha and IFN gamma with alpha 2-macroglobulin.

The binding of 125I-labelled recombinant human TNF alpha and IFN gamma to isolated human blood alpha 2-macroglobulin has been investigated using molecular sieving procedures and non-denaturing PA gel electrophoresis in combination with autoradiography. These studies revealed that both cytokines readily bind to the electrophoretically fast form of alpha 2M generated by methylamine or protease treatment of this protein. PAGE/SDS gel investigations indicated that TNF alpha bound non-covalently while the IFN gamma interaction was covalent in nature. Preliminary competition studies also indicate that cold TNF alpha and IL-2 are more effective than cold IFN gamma at inhibiting the binding of labelled IFN gamma to alpha 2M. Bioassays revealed that "native" alpha 2M or its derivatives at 2 mg/ml concentration did not impair the antiproliferative effects of TNF alpha and IFN gamma on susceptible bladder tumour cell lines. Furthermore they did not interfere in the induction of Class II antigen expression by IFN gamma on inducible cell lines or in a 2-site ELISA assay for TNF.

Antigens, Neoplasm↗

PubMed1992

Expression of adhesion molecules by bladder cancer cells: modulation by interferon-gamma and tumour necrosis factor-alpha.

The constitutive expression by eight human bladder cancer cell lines of the cell adhesion molecules intercellular adhesion molecule-1 and intercellular adhesion molecule-2 was studied using monoclonal antibody probes in conjunction with flow-cytometry. Tumour lines of low grade (G1) did not constitutively express intercellular adhesion molecule-1, rather they were found to express intercellular adhesion molecule-2. The G2 cells expressed no intercellular adhesion molecule-2, however, a low percentage did express intercellular adhesion molecule-1. High grade cells (G3) only expressed intercellular adhesion molecule-1 on their cell surface but at higher levels than the G2 cell line. Exposure of the bladder cancer cell lines to interferon-gamma induced and augmented the expression of intercellular adhesion molecule-1 by all except one of the cell lines (UMUC3). Intercellular adhesion molecule-2 expression remained unaltered. The modulation of intercellular adhesion molecule-1 expression was dependent on the concentration of interferon-gamma and the duration of stimulus. De novo intercellular adhesion molecule-1 expression, induced by interferon-gamma, was rapid (< 4 hours) with only a short period of stimulation being required (< 10 seconds). The rapid increase in expression of intercellular adhesion molecule-1 required de novo protein synthesis and was not the result of release of intercellular adhesion molecule-1 from an intracellular pool. Interferon-gamma and tumour necrosis factor-alpha were found to act synergistically in the induction and augmentation of intercellular adhesion molecule-1 expression. Optimal induction occurred with 10 Uml-1 of both molecules. These results suggest a correlation between constitutive adhesion molecule expression and the histopathological grade of the tumour. The implications of these findings for Bacillus Calmette Guerin and interferon-gamma immunotherapy of bladder cancer is discussed.

Carcinoma, Transitional Cell↗

PubMed1992

An investigation of factors influencing the in vitro induction of LAK activity against a variety of human bladder cancer cell lines.

We investigated the sensitivity of transitional cell carcinoma cells, derived from the human bladder, to lymphokine activated killer cells. Recombinant interleukin-2 activated peripheral blood mononuclear cells were studied for their ability to mediate the cytolysis of a panel of four established human bladder transitional cell carcinoma cell lines. Lymphokine activated killer activity was assessed using a standard four hour chromium release assay. All four bladder cancer cell lines proved to be susceptible to lymphokine activated killer mediated cytolysis. This was found to be dependent upon the dose of cytokine and upon the duration of the activation period. The four cell lines were differentially susceptible to lysis (specific cytotoxicity at effector to target ratio of 40:1; RT112 = 22.9%, RT4 = 49.2%, MGH-U1 = 49.1%, EJ18 = 62.3%). The varying susceptibility of lymphokine activated killer mediated cytotoxicity was found to be independent of the histological grade of the parent tumour or the donor of effector cells. Both interferon-alpha and tumour necrosis factor-alpha also elicited lymphokine activated killer cell activity, although the maximum specific cytotoxicity achieved was considerably lower than that obtained with interleukin-2 alone. Interleukin-2, at optimal concentration, and tumour necrosis factor-alpha were found to behave synergistically in the generation of lymphokine activated killer effectors. However, concentrations of tumour necrosis factor-alpha higher than 100 Uml.-1 resulted in a decrease in specific cytotoxicity. These findings suggest a possible use of adoptive immunotherapy in human bladder cancer and indicate the optimum conditions for the generation of such effector cells.

Carcinoma, Transitional Cell↗

PubMed1992

The inhibitory effects of interferon gamma on the growth of bladder cancer cells.

The inhibitory effect of interferon-gamma on the growth of three human bladder cancer cell lines, RT4, RT112 and MGH-U1, representing tumour grades 1, 2 and 3 respectively, was studied. The effects of 10, 100 and 1000 Uml.-1 of interferon-gamma on cell numbers and thymidine incorporation were measured at 24 hour intervals up to a maximum of seven days. Morphological appearances were also studied. Each line was susceptible to the growth inhibitory effects of interferon-gamma and this was both dose and time dependent. The effects of interferon-gamma, on the RT4 and RT112 cells were apparent from 24 hours, and were both cytostatic and cytotoxic in nature, whereas the effects on MGH-U1 cells were seen from 48 hours onwards and were only cytostatic. Cytological changes occurred in all three cell lines, being most pronounced in RT112. The growth of bladder cancer cells was inhibited by interferon-gamma, and in this study high grade tumour cells were least sensitive.

Carcinoma, Transitional Cell↗

PubMed1992

Intravesical Evans strain BCG therapy: quantitative immunohistochemical analysis of the immune response within the bladder wall.

Previous studies have demonstrated that is is the local immune response which is of importance for the anti-tumour activity of BCG therapy. We have investigated this by quantitative immunohistochemical analysis of serial bladder mucosal biopsies taken before, during and after an eight week course of intravesical Evans strain BCG therapy and three monthly thereafter in 16 patients (15 extensive CIS and one extensive G2pTa papillary tumour). This particular group of patients had a 67% complete response rate at six months post-treatment. The main findings on immunohistochemical analysis were the universal induction of MHC Class II antigens by urothelial cells which was statistically significant up to 6 months after completion of therapy, coupled with a T cell dominated cystitis. Increases in CD3+ T cell infiltration of the lamina propria and that of the CD4+ "Helper" subset which predominated were significant up to 3 months post-therapy and these cells showed evidence of increased immunological activation as shown by increased interleukin-2 receptor and MHC Class II antigen expression. There were also significant increases in CD68+ macrophage and the incidence of CD22+ B cell aggregates but CD57+ NK cells were sparse both before and after therapy. The degree of mononuclear cell infiltration for all markers examined (except CD57) was significantly greater in those biopsies in which the urothelial cells expressed MHC Class II antigens than in those that did not. Also the degree of T cell infiltration (CD3, CD4 and CD8) was significantly greater in the eight patients deemed to have had a complete response compared to those seven with a partial response or treatment failure. These results are discussed in terms of possible mechanisms of action for BCG therapy and in particular the role of enhanced antigen presentation by tumour cells.

Administration, Intravesical↗

PubMed1992

Evaluation of commercial enzyme immunoassays compared to immunofluorescence and double diffusion for autoantibodies associated with autoimmune diseases.

A commercially available enzyme immunoassay system for detecting autoantibodies to double-stranded DNA, deoxyribonucleoprotein, Smith, ribonuclearprotein, Sjögren's syndrome-associated antigens A and B, and scleroderma-associated antigen 70 was compared to the conventional immunofluorescence assay for double-stranded DNA and double diffusion assays for extractable nuclear antigens. There was excellent correlation between methods, but it appears that the enzyme immunoassays are more sensitive. Based on the results of this study, the authors recommend performing anti-nuclear antibody screening at two dilutions, with enzyme immunoassay follow-up of appropriate patient sera that are positive on anti-nuclear antibody testing. Nucleolar and centromere pattern anti-nuclear antibodies are diagnostic for variants of scleroderma and need no further evaluation. Negative anti-nuclear antibody tests performed using HEp-2 tissue culture cells require no further evaluation.

Antibodies, Antinuclear↗

PubMed1992

B cell responses to HIV and the development of human monoclonal antibodies.

In this review B cell responses in HIV-infected individuals are summarized together with the techniques used to date to produce human monoclonals to HIV and the properties of these antibodies. Profound disturbances in B cell responses are apparent both in vivo and in vitro. While there is evidence in vivo of marked polyclonal B cell activation, primary and secondary antibody responses are impaired. Similarly these cells exhibit spontaneous immunoglobulin secretion upon in vitro culture but do not readily respond to B cell mitogens and recall antigens including HIV. Furthermore, certain of these defects can be reproduced in normal B cells in vitro by incubation with HIV or HIV coded peptides. Individuals infected with HIV develop antibodies to HIV structural proteins (e.g. p17, p24, gp41 and gp120) and regulatory proteins (e.g. vif, nef, RT). Autoantibodies against a number of immunologically important molecules are also frequently observed. The anti-HIV antibodies are predominantly of the IgG1 isotype and exhibit a variety of effects on the virus in vitro. To date, using conventional immortalization strategies, an appreciable number of human monoclonals to HIV have been developed. These have been specific for gp41, gp120 and gag with antibodies of the former specificity predominating. The majority of these antibodies have been of the IgG1 isotype. Only a small number of the antibodies neutralize virus in vitro and most of these react with gp120. The neutralizing antibodies recognize conformational and carbohydrate epitopes or epitopes in amino acid positions 306-322. The predominant epitopes recognized by the anti-gp41 antibodies were in amino acid positions 579-620 and 644-662. A high percentage (congruent to 25%) of these antibodies enhance viral growth in vitro. The problems relating to the production of human monoclonals to HIV are discussed together with strategies that could be used in the future.

Animals↗

PubMed1992

Immunosuppression by human seminal plasma--extracellular organelles (prostasomes) modulate activity of phagocytic cells.

PROBLEM: Prostasomes are trilamellar to multilamellar vesicles produced by the acinar cells of the human prostate and are present in appreciable amounts in normal human semen. The aim of this work was to study the effect of prostasomes on human polymorphonuclear cell and monocyte function. METHODS: Functional activity of human neutrophils and monocytes was studied after incubation with prostasomes isolated from normal human seminal plasma. The following functional tests were employed: ability to ingest latex particles and opsonized bacteria (St. aureus) and ability to generate superoxide anion in response to PMA and FMLP. The latter was determined by measuring the superoxide-dismutase inhibitable reduction of ferricytochrome c to ferrocytochrome c at 550 nm. Expression of cell surface markers and interactions of prostasomes with cells were studied by cytofluorimetry. RESULTS: We show that prostasomes bind rapidly to the leukocyte cell membrane followed by internalization of adsorbed material. Interactions of prostasomes with neutrophils and monocytes inhibits their ability to phagocytose latex particles. The ability to ingest opsonized bacteria is, however, not impaired. Our results also show that incubation of leukocytes with prostasomes effectively inhibits superoxide anion generation in response to activation by PMA and FMLP. CONCLUSIONS: Prostasomes may play a complementary role to other immunosuppressive factors contained in the human semen. They may protect sperm cells from deleterious effects of phagocytosing cells, prolong their life, and consequently enhance the chance of conception. At the same time prostasomes may have a permissive effect on sexually transmitted diseases.

Cell Adhesion↗

PubMed1992

Susceptibility of human monoclonal antibody-producing B cell lines to infection by human immunodeficiency virus.

Seven immortalized B cell clones, five of which secreted specific human monoclonal antibodies (MAbs) against hepatitis B, tetanus toxoid, and Rhesus D antigens, were evaluated for their susceptibility to infection by human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2). Infection was confirmed in three human MAb-producing lines by detection of infectious virus and p24 antigen in culture supernates, by immunofluorescence, and by detection of viral DNA in cells by polymerase chain reaction. The infectable lines were as susceptible to HIV-1 infection as several T cell lines and remained persistently infected for several months, but in contrast to T cell controls, viral cytopathic effects were not observed. Levels of unintegrated viral DNA in the HB1 B cell line were significantly lower than in the HUT78 T cell line. Cell lines that were susceptible to HIV expressed HLA DR, CD20, and CD21, whereas the uninfectable cell lines did not express any of the markers tested. CD4 was undetectable or present on a small percentage of cells in two of the infectable cell lines. However, infection with HIV-1 was blocked more efficiently in B cells than in T cells by soluble CD4, anti-CD4 MAb, and dextran sulphate. The effect of HIV infection on human MAb secretion was variable, being reduced on a per-cell basis in one line, increased in another, and unchanged in a third.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

PubMed1992

DNA mutations associated with the human butyrylcholinesterase J-variant.

The J-variant of human serum butyrylcholinesterase (BChE) causes both an approximately two-thirds reduction of circulating enzyme molecules and a corresponding decrease in the level of BChE activity present in serum. Since the level of serum BChE activity and the duration of succinylcholine apnea are inversely correlated, this marked decrease in activity makes individuals with the J-variant more susceptible than usual subjects to prolonged apnea from succinylcholine. We reinvestigated the same family in which Garry et al. identified the J-variant phenotype. The atypical, fluoride, and K-variant mutations were also identified in members of the 47-person pedigree. DNA amplification by PCR, followed by direct sequencing of the amplified DNA, led to the finding that the J-variant phenotype of human serum BChE was associated with two DNA point mutations in the coding region. One of these was the mutation previously identified with the K-variant phenotype (GCA----ACA; Ala539----Thr). The other was an adenine-to-thymine transversion at nucleotide 1490, which changed amino acid 497 from glutamic acid to valine (GAA----GTA; Glu497----Val). This latter point mutation was named the J-variant mutation (formal name BCHE*497V). The J-variant mutation has not been identified without the K-variant mutation. The J-variant mutation created an RsaI-enzyme RFLP. Two additional point mutations, located in the noncoding regions of the gene, were also found to be linked with the J-variant and K-variant point mutations on the same allele. These noncoding polymorphic mutations had previously been found linked to the atypical and K-variant point mutations. A summary table shows dibucaine, fluoride, and Hoffmann-La Roche compound Ro 2-0683 inhibition numbers for 119 samples whose DNA has been sequenced. Eighteen BChE genotypes are represented.

Amino Acid Sequence↗

PubMed1992

Role of adhesion molecules in lymphokine-activated killer cell killing of bladder cancer cells: further evidence for a third ligand for leucocyte function-associated antigen-1.

The lysis of eight human bladder cancer cell lines by lymphokine-activated killer cells (LAK) was found to be partially dependent upon the expression by the target cell of either intercellular adhesion molecule-1 (ICAM-1) or intercellular adhesion molecule-2 (ICAM-2). Using adhesion blockade studies these molecules were found to contribute towards sensitivity to lysis. Tumour lines of low grade (G1) did not constitutively express ICAM-1, but were found to express ICAM-2. High grade cells (G2, G3), however, only constitutively expressed ICAM-1 on their cell surface. Interferon-gamma (IFN-gamma) induced and augmented the expression of ICAM-1 by all except one of the cell lines (UMUC3) in a dose- and time-dependent manner. This was accompanied by an increased susceptibility to lymphokine-activated killer mediated cytolysis. Anti-ICAM-1 antibodies partially inhibited the increase in cell lysis due to IFN-gamma. However, this inhibition was not complete. When effector cells were treated with antibodies to leucocyte function-associated antigen-1 (LFA-1) the inhibition of lysis was greater and ranged from 72 to 96% with a mean of 87% inhibition. These results suggest that the increased sensitivity of IFN-gamma-treated bladder cancer cell lines to LAK cells is partially attributable to the induction of ICAM-1. However, blocking of ICAM-1 with antibodies could only partially inhibit the increased LFA-1-dependent lysis. This supports recent evidence for the existence of an additional ligand for LFA-1, other than ICAM-1 and ICAM-2.

Antigens, CD↗

PubMed1992

Laboratory staff qualifications and accuracy of proficiency test results. A national study.

In the last quarter of 1988, laboratories from across the country that participated in the College of American Pathologists (Northbrook, Ill) proficiency testing program were asked to complete a questionnaire describing their staffing pattern and submit it with their test results. Laboratories were then divided into two groups, those employing 100% American Society of Clinical Pathologists (Chicago, Ill) certified technologists and those employing 0% American Society of Clinical Pathologists certified technologists. The nonparametric Wilcoxon significance test was used to determine differences in accuracy of test results for laboratories in each group. Significant differences were found for the basic laboratory survey, comprehensive diagnostic immunology, comprehensive blood banking, comprehensive hematology, and comprehensive chemistry. chi 2 Analysis revealed that laboratories employing 100% American Society of Clinical Pathologists certified technologists had a significantly higher probability of achieving 80% accuracy across all surveys. These results present a strong argument that staffing with qualified technologists contributes to maximizing the quality of laboratory services offered to the public.

Allergy and Immunology↗

PubMed1991

Does metoclopramide reduce the length of ileus after colorectal surgery? A prospective randomized trial.

Between August 1988 and September 1989, 100 consecutive patients who underwent elective abdominal colorectal surgical procedures were prospectively randomized to receive or not to receive metoclopramide. Metoclopramide was intravenously administered every 8 hours from the completion of surgery until a solid food diet was able to be tolerated. Seven patients were not included in the final tabulations because of one death, one small bowel obstruction requiring laparotomy, one anastomotic leak requiring laparotomy, and four protocol violations. Ninety-three patients, 37 men and 56 women (mean age, 59.5; range, 14-89 years) underwent 40 segmental colectomies, 13 total abdominal colectomies, 8 abdominoperineal resections, 8 ileoanal pouch procedures, 7 small bowel resections, and 17 other colorectal procedures. The 40 patients who received postoperative metoclopramide were in Group 1, and the 53 who did not were in Group 2. The mean length of time between laparotomy and commencement of oral fluid and oral solid intake in Groups 1 and 2 were 3.5 and 4.8 days, and 3.5 and 5.0 days, respectively. These differences were not statistically significant (P greater than 0.05). Prolonged ileus was seen in seven patients in Group 1 and in eight patients in Group 2. These differences were also not statistically significant (P greater than 0.05). Prolonged ileus was defined as the need for nasogastric tube reinsertion or discontinuation of oral intake. We conclude that metoclopramide does not significantly alter the course of postoperative ileus.

Adolescent↗

PubMed1991

The double-stapled ileal reservoir and ileoanal anastomosis. A prospective review of sphincter function and clinical outcome.

Fifteen consecutive patients (nine males and six females) who underwent construction of a double-stapled ileoanal reservoir (DS-IAR) were prospectively evaluated. Mean and maximal resting pressures preoperatively, before ileostomy closure, and at 12 months, were 53 and 84 mm Hg, 39 and 62 mm Hg, and 62 and 81 mm Hg. Mean and maximal squeeze pressures at those same time periods were 96 and 153 mm Hg, 111 and 173 mm Hg, and 95 and 168 mm Hg. There were no significant decreases in either resting or squeeze pressure between preoperative values and those obtained 12 months after surgery. However, the length of the high pressure zone decreased from 3.8 cm preoperatively to 2.3 cm at 12 months. This reflects the sacrifice of the cephalad 1.5 cm of the internal anal sphincter necessary to effect this anastomosis at a mean of 1.4 cm from the dentate line. However, this maneuver did not result in poor continence. Eleven patients whose ileostomies were closed for a mean of 9 months, ranging from 3 to 15 months, were evaluated regarding functional outcome. Only one patient had any incontinence and this patient had incomplete circular-stapled tissue rings, which necessitated transanal suture repair of the anastomotic defect. Similarly, three of the four patients who sometimes or rarely use a pad at night had transanal-suture reinforcement. Ten of the 11 patients never wear a pad during the day. No pelvic or perianal sepsis occurred. Stratified squamous epithelium was found in 6 of the 13 distal stapler "donuts" that were examined. In addition, 10 patients underwent biopsy of the tissue immediately caudad to the circular staple line at the time of ileostomy closure; in five, only stratified squamous epithelium was noted. The DS-IAR is associated with excellent objective physiologic and subjective functional results.

Adenomatous Polyposis Coli↗

PubMed1991

Immunosuppression by seminal plasma from fertile and infertile men: inhibition of natural killer cell function correlates with seminal PG concentration.

Human seminal plasma has uniquely high concentrations of PGE and 19-hydroxy PGE but the function of these PGs has not been elucidated. PGs of the E series have been shown to be paracrine and autocrine regulators of the function of immune cells and high levels of PGE have been shown consistently to suppress function in such cells. Human seminal plasma has a potent immunosuppressive effect and evidence is accumulating that this is largely due to PG components. In this study the effects of human seminal plasma on the killing activity of natural killer (NK) cells as judged by 51Cr release from K562 cells have been studied in groups of fertile and infertile men. Although there was no significant difference in the PGE, 19-hydroxy PGE or the NK cell inhibitory activity in the two groups, the inhibition of NK cell activity was closely correlated with the PGE and the 19-OH PGE content of the seminal plasma in the fertile group. This finding is further evidence that the major contribution to the immunosuppressive properties of human semen is provide by the high concentration of PGs of the E series in this fluid.

Alprostadil↗