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Biomedical subjects

D Katz

Publications and source records attributed to D Katz.

At least 145 records · Page 8Linked to original sources
PubMed1986

Implementation and evaluation of control strategies for individualizing dosage regimens, with application to the aminoglycoside antibiotics.

Three strategies are implemented for controlling serum concentrations by determining individualized dosage regimens. The methods incorporate, respectively, nonlinear least squares parameter estimation, Bayesian maximum a posteriori probability estimation, and a stochastic control procedure that minimizes the expected value of an appropriate therapeutic cost. The performance of the three dose regimen calculation strategies was evaluated using Monte Carlo simulations of a typical therapeutic protocol for tobramycin.

Adolescent↗
PubMed1986

ELISA for detection of IgG and IgM antibodies to HSV-1 and HSV-2 in human sera.

A rapid, enzyme-linked immunoassay (ELISA) was applied to identify and measure specific IgG and IgM antibodies to herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2). Detergent solubilized infected cells and mock-infected cells were used as antigens in the assay. Identification of type-specific antibodies was achieved by a competition assay in which clinical sera mixed with HSV-1 or HSV-2 antigens were assayed for reactivity to identical antigens coating wells of polystyrene microtiter plates. Reactivity and the specificity of the reactive immunoglobulin class was quantitated using biotinylated goat anti-IgG and biotinylated goat anti-IgM. Five paired sera from patients with diagnosed herpes simplex genital infections and one human anti-HSV-1 reference serum were tested with this assay and results were compared to results previously obtained using a complement fixation test and micro-SPRIA. The results indicate that the ELISA is a specific, sensitive and simple test which confirms the herpes simplex virus infection history of patients.

Animals↗
PubMed1986

ELISA for detection of group-common and virus-specific antibodies in human and simian sera induced by herpes simplex and related simian viruses.

A rapid (3.5 h) enzyme-linked immunosorbent assay (ELISA) was developed for the detection of serum antibodies to herpes simplex virus type 1 (HSV-1) and to two antigenically related monkey viruses, simian agent 8 (SA8) and Herpesvirus simiae (B virus). Crude preparations of detergent solubilized infected cells and similarly treated control mock-infected cells served as antigens for coating wells in microplates. Biotinylated protein A and avidin-conjugated alkaline phosphatase were used to detect antibodies in sera from different species (humans, monkeys and rabbits). Three prototype assays are described with three degrees of specificity. Common or specific determinants on the viral antigens could be assayed in simple competition tests using similar antigen preparations to those coating the wells. The specific assays permitted rapid differential serodiagnosis of antibodies to human and simian herpesviruses.

Animals↗
PubMed1986

Genetic control of HLA-linked immune responsiveness to (H,G)-A-L.

Fifty-three donors belonging to seven families were tested for their immune response potential to (H,G)-A-L. Most of these donors had been previously tested for their ability to respond to (T,G)-A-L and were all HLA typed as well. The heredity of the ability to respond to (H,G)-A-L by the production of an antigen-specific helper T cell factor is compatible with an autosomal dominant trait linked to HLA. The genotype of an HLA-A/B recombinant individual suggested that a gene controlling the immune response to (H,G)-A-L is linked to HLA-A. Lod scores also suggested a linkage between immune response potential to (H,G)-A-L and HLA-A. The different patterns of responses to (T,G)-A-L and (H,G)-A-L observed in many individuals are compatible with the notion that separate loci are governing the immune responses to the two synthetic polypeptides.

Female↗
PubMed1986

Antigen specific immune response potential and HLA typing of Israeli patients with thyroid autoimmune diseases (TAD).

The immune response potential to the synthetic polypeptide antigen (T,G)-A--L was studied in 35 patients with thyroid autoimmune diseases (TAD). For this purpose the ability of their antigen activated peripheral blood lymphocytes (PBL) to generate a (T,G)-A--L specific helper factor was tested. In addition, the patients were typed for their HLA determinants. The results of the study have shown that 20/35 (57%) patients responded to (T,G)-A--L, a similar proportion to that found among healthy donors that were tested as control. No significant difference was found in the rate of responses between patients with Graves' disease and Hashimoto's thyroiditis. The responses in these groups of patients were shown to be 13/22 (59%) and 7/13 (54%) respectively. HLA typing of 26 patients with TAD did not demonstrate any association of the disease or the immune response potential with any specific HLA determinant. It is proposed that unlike the general lack of regulation that we have previously observed in patients with systemic lupus erythematosus, the abnormal autoimmune reaction in TAD and probably in other organ-specific autoimmune diseases, is towards a specific organ without affecting other arms and functions of the immune system.

Autoimmune Diseases↗
PubMed1986

Analysis of antigen specific T cell helper function in first degree relatives of patients with systemic lupus erythematosus (SLE).

Fourteen families with first degree relatives of patients with systemic lupus erythematosus (SLE) were studied for the ability of their members to respond to the synthetic polypeptide antigen (T,G)-A-L. The family members were also tested for their HLA determinants. All SLE patients tested responded to (T,G)-A-L as measured by the production of (T,G)-A-L specific T cell helper factors by their antigen activated T cells, confirming our previous findings that 100% of SLE donors responded to (T,G)-A-L in contrast to 50% responders in a control population of healthy donors. The general defect in the regulation of immune responses in SLE patients was further indicated by the demonstration that an SLE patient who is a daughter of non-responder parents to (T,G)-A-L, responded to this genetically regulated antigen. In contrast to our observations with SLE patients, the genetic regulation of the ability to respond to (T,G)-A-L was shown not to be impaired in healthy first degree family members of SLE patients and the segregation of the immune response potential in these families was as expected from an inherited dominant trait.

Animals↗
PubMed1985

Familial mesothelioma: review and family study.

To date, with few exceptions, primary attention to the etiology of malignant mesothelioma has been focused on environmental factors. However, several reports of familial aggregations of mesothelioma strongly support the supposition that host factors, in concert with environmental exposure, particularly asbestos, may contribute etiologically to an as yet unknown fraction of occurrences of this disease. However, in evaluation of familial mesothelioma, it is important to consider the possibility of household exposure to asbestos. We report a family in which two brothers with prolonged occupational asbestos exposure manifested malignant pleural mesotheliomas of similar histology.

Aged↗
PubMed1985

Determination of human IgG and IgM class antibodies to West Nile virus by enzyme linked immunosorbent assay (ELISA).

An enzyme-linked immunosorbent assay (ELISA) was developed and used for the detection of IgG and IgM antibodies to West Nile virus in human sera. Thirteen paired sera of clinical cases and 24 control sera taken randomly from a blood bank repository were tested. The sera were reacted in microtiter plates coated with PEG-treated WNV antigen. IgG or IgM antibodies were quantitated by the use of alkaline-phosphatase-conjugated anti-human IgG or IgM antibodies. Of the 24 randomly collected serum samples, 7 were positive in the IgG-ELISA test. One positive by the IgM-ELISA was found to contain rheumatoid factor. In 12 of 13 paired sera of clinical cases, IgM as well as IgG antibodies were detected in the second serum sample taken about 3 wk after the onset of clinical signs. The IgM positive sera were screened for rheumatoid factor (RF) on IgG-coated plates. None of them contained RF. Antibody titers obtained by ELISA showed a good correlation with titers obtained by hemagglutination inhibition, complement fixation, and neutralization tests. The ELISA tests for detection of IgM and IgG antibodies to WNV therefore can replace the other serological methods for epidemiological surveillance and diagnostic purposes.

Antibodies, Viral↗
PubMed1985

Comments on mean residence time determination.

In a recent paper, D. O. Chanter challenged the applicability of the use of statistical moments in estimating mean residence time and proposed an alternative approach. Errors in that paper are pointed out which involve the improper equating of whole-body amount of drug with plasma amount of drug in a kinetic system. The theory for the two methods discussed by Chanter is presented in a pharmacokinetic context.

Body Burden↗
PubMed1985

Familial embryonal carcinoma in a cancer-prone kindred.

Familial testicular cancer is rare. This report describes a family with an unusual cancer spectrum that included the infantile form of embryonal carcinoma of the testis in the son of a cancer-free but putative obligate gene carrier mother, and the adult form of embryonal carcinoma in this women's maternal half-brother (their mutual mother had malignant melanoma and urinary bladder carcinoma). Hereditary syndrome designation remains elusive. Priority attention to biomarker research in families of this type for elucidation of cause and control is discussed.

Adult↗
PubMed1985

Interleukin-2 production in head and neck cancer patients.

Interleukin-2, a lymphocyte-produced hormone or lymphokine, is required to support proliferation of antigen-triggered T lymphocytes and cytotoxic T cells that are considered essential elements for host tumor control. We have addressed the question of whether interleukin-2 production is altered in head and neck cancer patients, a group that is frequently immunosuppressed. Interleukin-2 production was measured by the tritium-labeled thymidine CT6 assay on the supernatants of peripheral blood lymphocytes of head and neck cancer patients and controls after 24 hour stimulation with phytohemagglutinin. The mean levels of interleukin-2 produced were 127 units (range 3 to 336 units) in the head and neck cancer patients versus 125 units (range 26 to 307 units) in the control group (not statistically significant). There were no significant differences in mean interleukin-2 values between cancer patients with stages I and II or III and IV disease compared with the control subjects. Twenty-seven percent of the cancer patients had interleukin-2 levels below the 10th percentile cutoff point (p = 0.015). The lymphocyte proliferative response to phytohemagglutinin was significantly depressed in the head and neck cancer patients compared with the control subjects. This did not correlate with interleukin-2 production abnormalities, except in patients with advanced disease, in whom there was a borderline correlation between phytohemagglutinin response and interleukin-2 production (correlation coefficient 0.23, p = 0.05). We conclude that the commonly observed depressed T-cell proliferative response to phytohemagglutinin in head and neck cancer patients is not explained by impaired interleukin-2 production.

Adult↗
PubMed1985

Use of chicken and rabbit antibodies in a solid phase protein A radioimmunossay for virus detection.

A new rapid indirect solid phase radioimmunoassay was developed for the detection of Sindbis virus. Chicken antibodies were adsorbed onto wells in microplates to serve as 'capture antibodies' and rabbit antibodies were used as the second antibody. 125I-labelled protein A that does not bind to chicken antibodies, but binds firmly to rabbit antibodies was used as the tracer. All the steps necessary for the development of the assay are described. The minimal amount of Sindbis virus detectable was around 3 x 10(5) PFU/ml and the interassay reproducibility was about +/- 30%.

Animals↗
PubMed1985

HLA-linked immune responsiveness to (T,G)-A-L: a family study.

The heredity of the immune response potential to the synthetic polypeptide poly(LTyr,LGlu)-poly(DLAla)-poly(LLys) [(T,G)-A-L] and its possible linkage to the major histocompatibility complex of man were studied in 24 families. Peripheral blood lymphocytes (PBL) obtained from 174 donors belonging to 24 unrelated families were educated to (T,G)-A-L on autologous antigen-pulsed adherent cells. The supernatants obtained from these activated PBL were tested for their antigen-specific helper activity in an in vitro antibody production system. All donors were typed for their HLA haplotypes. The results obtained indicated that the ability to respond to (T,G)-A-L by production of an antigen-specific T cell helper factor is inherited as an autosomal dominant trait linked to the responder HLA haplotype.

Alleles↗
PubMed1985

[Growth potential of vascularized epiphyseal bone transplants. Experimental and clinical study].

The objectives of this work were to evaluate, in the light of experimental results, the growth potential of vascularized fertile epiphyseal bone transplants transferred with their surrounding soft tissues in children. Thirty-one toe transfers were available for analysis from the series performed in Trousseau hospital (Paris). The results were reviewed with the unique goal of the study of growth. Transferred toes grow in an almost identical fashion to normal toes. The slightly diminished growth difference found was in accordance with experimental results. Criteria for determining the growth of these transfers must be very strict from a clinical as well as from a radiological point of view. The possibility of transfer of an isolated epiphyseal growth cartilage implies previous elaborate studies of the anatomy of epiphyseal vascularity as well as the physiology of intraosseous blood flow. Restoration of this potential for growth in children should be attempted as early as possible.

Adolescent↗
PubMed1985

Intestinal absorption of thiamin from yeast-containing sorghum beer.

The rate of absorption of 14C-thiamin added to sorghum beer has been studied in isolated loops of rat duodenum and adjacent jejunum. Appreciable amounts of the vitamin were absorbed in spite of the presence in the beer of alcohol and live yeast cells avid for the vitamin. These results suggest that commercially brewed sorghum beer, a beverage consumed widely by Third World populations, can be fortified with thiamin to prevent the development of deficiency of the vitamin in habitual consumers of the beer.

Animals↗
PubMed1985

Cable television and health promotion: a feasibility study with arthritis patients.

Community access cable television channels can be used to provide low-cost health programming in many communities. This article describes a study undertaken to ascertain the extent to which arthritis patients could be targeted by arthritis-related programming over a local cable system. A number of publicity sources were used to advertise the programs to a preidentified group and the public at large. Telephone and written surveys revealed that the programming garnered a moderate viewing audience composed preponderantly of arthritis patients. Some conceptual and practical issues involved in targeting chronic patient groups for health programming are discussed.

Arthritis↗