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Biomedical subjects

R J Ablin

Publications and source records attributed to R J Ablin.

At least 19 recordsLinked to original sources
PubMed1992

Immunosuppression by human seminal plasma as evaluated by effect on natural killer cell cytotoxicity.

Re-examination of earlier observations of the suppressive role of oxidized polyamines and their cytotoxic products, has suggested that immunosuppression by seminal plasma (SePl) observed in in vitro assays employing culture medium supplemented with serum containing amine oxidase is 'artefactual'. Investigation of the relevancy of this suggestion to immunosuppression of natural killer (NK) cell activity by SePl as related to NK cell viability was made. NK cells in various culture regimens were preincubated in SePl and medium supplemented with 10 per cent foetal bovine serum, a source of amine oxidase, without and with 0.2 mM hydroxylamine, an amine oxidase inhibitor, and 10 per cent normal human AB serum, virtually devoid of amine oxidase, and examined for viability up to 72 h by trypan blue dye exclusion and lytic activity in a 4 h 51chromium-release microcytotoxicity assay. Viability to NK cells varied with the concentration of SePl, culture medium and time of incubation. At 18 and 24 h, times corresponding to preincubation and completion of the NK cell assay, viability was greater than or equal to 75 per cent for the optimum inhibitory concentration of SePl, irrespective of the culture medium. Comparison of the lytic activity of NK cells preincubated with the optimum inhibitory concentration of SePl in the various culture regimens did not disclose significant (P less than 0.05) differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Survival↗
PubMed1991

Identification and possible biological relevance of spermatozoal transglutaminase.

Normal human spermatozoa were demonstrated by dot immunoblot analysis and immunohistochemistry to possess transglutaminase (TGase). The immunological identification of spermatozoal TGase is consistent with reports by others of its biochemical identification and suggested role in sperm motility, and provides, in view of the immunoregulatory properties of seminal plasma TGase, presumptive identification of a means whereby spermatozoa, under normal physiological conditions, may possibly be protected from immunological 'attack' within the female reproductive tract.

Fluorescent Antibody Technique↗
PubMed1991

Intracellular sequestration and transmission of HIV-1 in pregnancy.

30-50% of infants born to HIV-1 seropositive mothers are infected. Although a vertical transmission of the virus to the foetus via trophoblastic cells and mechanisms of its access thereof have been made, one of several questions which remains is: how do HIV-1 infected cells of monocyte/macrophage (MM) lineage, i.e. Hofbauer cells, which facilitate viral transmission, avoid cytolytic destruction vs. that which occurs in infected CD4+ T-cells and serve as a reservoir for virus, wherein it replicates? Recent studies of transglutaminases (TGases), a ubiquitous family of Ca(2+)-dependent peptide ligases catalyzing the post-translational covalent cross-linking of proteins and incorporation of amines into proteins have revealed a unique spectrum of immunoregulatory (IR) properties. In consonance with these studies, the biochemical and immunohistochemical identification of decidual and placental TGases, and their associated IR properties, and earlier studies of uterine and placental macrophages, a hypothesis is purposed to account for the intracellular assembly and accumulation of HIV-1 within cells of MM lineage, and transmission therefrom, in pregnancy.

Female↗
PubMed1991

The persisting enigma of AIDS-associated Kaposi's sarcoma: a hypothesis.

The widespread prevalence of Kaposi's sarcoma during the HIV/AIDS epidemic and its unique epidemiological predilection for select groups 'at risk' for AIDS relative to their 'life-style' orientation provide the rationale for etiologic agent(s) other than HIV. In keeping with the requisites for the development and progression of malignancy, i.e., the transformation of normal to aberrant cells and the failure of host defenses to control them, is the rationale, in view of their respective properties, for the hypothesized participation of spermatozoa and/or seminal fluid components as being contributory to the development of Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Increased density of histiocytes in uterine leiomyomas.

The histiocyte content of leiomyomata and adjacent, histologically normal myometrium has been quantified morphometrically with the help of recently developed immunostaining for tissue macrophages. Histiocytes identified by immunoreaction for Factor XII subunit A and by double immunofluorescent labelings were found to be identical with tissue macrophages present in normal uteri. Histiocyte counts were significantly higher in leiomyomatous areas than in adjacent normal myometrium, and the distribution of these cells was also changed. In the normal uterine wall, histiocytes could be detected only in the connective tissue septa separating smooth muscle bundles, while in the myomatous nodules they were diffusely scattered throughout the whole area. In addition to providing new information on the cellular composition of leiomyomas, the present observations also raise several questions concerning the possible pathogenetic role of FXIII-positive histiocytes in neoplastic proliferation of uterine smooth muscle.

Factor XIII↗
PubMed1990

Effect of human seminal plasma on the lytic activity of natural killer cells and presumptive identification of participant macromolecules.

Using the lytic activity of natural killer (NK) cells as an in vitro parameter, the immunoregulatory properties of human seminal plasma (SePl) and participant macromolecules have been investigated. Significant (P less than 0.05) suppression of NK cell activity by SePl and chromatographically separable fractions was demonstrated in association with high and low molecular weight (Mr) macromolecules. SePl suppression was retained after heating to 56 degrees C for 30 min, and appeared to function at the level of the effector, rather than target cell. Physicochemical characterization of high and low Mr fractions provided presumptive identification of the participation of transglutaminase and prostaglandins as the principal molecules contributory to SePl immunosuppression.

Humans↗
PubMed1988

Fibrinolysis resistant fibrin deposits in lymph nodes with Hodgkin's disease.

Extravasal fibrin deposition is frequently observed within and around tumorous tissues and has been implicated in various aspects of tumor growth. However, no adequate information has been available on the mechanism how intratumoral interstitial fibrin deposits escape a prompt elimination by the fibrinolytic system. In this study we provide immunomorphological evidence showing that fibrin deposits in lymph nodes with Hodgkin's disease are stabilized and made resistant to fibrinolysis by factor XIII (FXIII) of blood coagulation. By double immunofluorescent labelling systems fibrin deposits were simultaneously stained for alpha 2-antiplasmin (alpha 2-AP), the main physiological inhibitor of fibrinolysis and in a number of nodular areas they were also labelled for plasmin(ogen). The detection of alpha 2-antiplasmin-plasmin complex-neoantigen (alpha 2-AP-P-Neo) revealed that alpha 2-AP reacted with plasmin, i.e., alpha 2-AP covalently linked to fibrin indeed inhibited intratumoral fibrinolysis. In addition to fibrin deposits FXIII was also found in cellular elements characterized earlier as tumor associated macrophages. These cells were attached to fibrin strands suggesting that they are involved in the intratumoral fibrin formation and might be a source of fibrin stabilizing factor in the tumor stroma.

Fibrin↗