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Biomedical subjects

J H Herman

Publications and source records attributed to J H Herman.

At least 73 records · Page 4Linked to original sources

Modifying oculomotor activity in awake subjects increases the amplitude of eye movements during REM sleep.

The eye movements of human subjects were experimentally modified while they were awake to determine the effect of waking experience on electroculographic activity during rapid eye movement (REM) sleep. After normal eye movements were monitored under controlled conditions, subjects spent 5 days wearing goggles that contained minification lenses and that curtailed vision to a 5 degree field. The amplitude and frequency of eye movements decreased when subjects were awake and increased during REM sleep; sleep stage durations and distributions were unaffected. Values returned to normal in the first 24 hours of recovery.

Adult↗

A bitter cure.

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Condiments↗

Lymphokine-mediated suppression of chondrocyte glycosaminoglycan and protein synthesis.

Spontaneously released and T cell mitogen augmented lymphokine produced by human mononuclear cells has been shown to induce a concentration dependent reversible suppression of chondrocyte glycosaminoglycan and protein synthesis without significantly enhancing chondrocyte catabolic activity. The modulatory factor(s) is of T cell origin and is trypsin, pronase, and heat sensitive. Prostaglandin inhibitors failed to influence factor formation or activity. Although eluting from Sephadex G-100 over a wide range, peak activity had an approximate molecular weight of 53,000 and appeared distinct from recognized forms of lymphotoxin.

Amino Acids↗

Histologic assessment of lymphokine-mediated suppression of chondrocyte glycosaminoglycan synthesis.

An experimental model has been developed to histologically assess the effect of T cell mitogen-induced lymphokines derived from rabbit splenocytes on proteoglycan matrix depleted auricular cartilage explant glycosaminoglycan synthesis. Explant exposure to lymphokine was shown by light and electron microscopy to significantly suppress chondrocyte glycosaminoglycan regenerative capacity. This inhibitory effect was reversible in that synthetic activity could be restored by placement of explants in control media after as long as 12 days of lymphokine exposure.

Animals↗

In vitro studies in reproductive immunology. - 2. Demonstration of the inhibitory effect of male genital tract constituents on PHA-stimulated mitogenesis and E-rosette formation of human lymphocytes.

The effect of male genital tract components (human spermatozoa, intact and chromatographed seminal plasma fractions) on in vitro cell-mediated immune reactions was examined. Their addition to PHA-containing lymphocyte cultures resulted in a marked degree of inhibition of DNA synthesis, the response varying with the fractions employed. The interference by such components with a terminal cell event during blast transformation was suggested by the failure of stimulated cultures to incorporate thymidine irrespective of the time during the incubation period at which the constituents were added. Seminal plasma and sperm extracts were also shown to inhibit T-cell associated E-rosette formation. The inhibitory properties of genital fractions remained unaltered after repetitive freeze-thaw cycling when tested in the transformation and E-rosette assays. Heating to 100 degrees C modified the response with some of the fractions.

Humans↗

The effect of human spermatozoa on antigen and mitogen induced blastogenesis.

In an attempt to identify factors capable of specifically or nonspecifically modulating results in an in vitro blastogenic assay system, studies were performed evaluating cell mediated immune response to human spermatozoa. Spermatozoa were capable, on a dose dependent basis, of both inhibiting and stimulating normal lymphocyte DNA synthesis as well as suppressing mitogen-induced response. Pretreatment of spermatozoa with neuraminidase and alpha-methyl-D-mannoside abrogated suppressive properties on spontaneous and/or mitogen-induced stimulation. Such suppressive activity on mitogen-induced response was observed using B and T-cell enriched populations. Inhibitory properties were not evident using intact cell populations stimulated by specific antigen. It is suggested that: (1) receptors on spermatozoa bind lectin; and (2) such receptors can be inactivated by enzymes having glycoprotein specificity.

Humans↗

Phytomitogen-induced, lymphokine-mediated cartilage proteoglycan degradation.

The significance of T-cell activation in the immunopathogenesis of articular disease has been studied in an in vitro model to assess the capacity of phytomitogen-induced lymphokines to degrade cartilage matrix proteoglycans. Supernatants derived from T-cell activation of normal human peripheral blood lymphocytes were shown to contain a monocyte-dependent, serum-inhibitable, dialyzable factor or factors capable of inducing significant proteoglycan degradation, as assessed by release of macroprecipitable 35S-labeled proteoglycan from heterologous cartilage substrates.

Animals↗

Polydispersity of human articular cartilage proteoglycan antigens.

Studies were undertaken to define more fully the antigenic properties of human articular cartilage proteoglycans, in anticipation of its potential contribution to alterations arising in diseased states and following cartilage transplantation. Proteoglycans, extracted from normal, adult articular cartilage by dissociative measures, were subjected to purification by cesium density gradient ultracentrifugation, under conditions facilitating both molecular aggregation and dissociation. A polydisperse population of reactive determinants was observed in immunodiffusion and hemagglutination inhibition systems, employing proteoglycan specific antisera on gradient fractions. Highly aggregated proteoglycan species appeared to contain potentially masked antigenic determinants, which were revealed after guanidine dissociation but not hyaluronidase digestion. Polyacrilamide disc gel electrophoresis in sodium dodecyl sulfate, in conjunction with disc elution experiments, confirmed proteoglycan antigenic polydispersity.

Adult↗

Immunopathologic studies in relapsing polychondritis.

Serial studies have been performed on three patients with relapsing polychondritis in an attempt to define a potential immunopathologic role for degradation constituents of cartilage in the causation and/or perpetuation of the inflammation observed. Crude proteoglycan preparations derived by disruptive and differential centrifugation techniques from human costal cartilage, intact chondrocytes grown as monolayers, their homogenates and products of synthesis provided antigenic material for investigation. Circulating antibody to such antigens could not be detected by immunodiffusion, hemagglutination, immunofluorescence or complement mediated chondrocyte cytotoxicity as assessed by (51)Cr release. Similarly, radiolabeled incorporation studies attempting to detect de novo synthesis of such antibody by circulating peripheral blood lymphocytes as assessed by radioimmunodiffusion, immune absorption to neuraminidase treated and untreated chondrocytes and immune coprecipitation were negative. Delayed hypersensitivity to cartilage constituents was studied by peripheral lymphocyte transformation employing [(3)H]thymidine incorporation and the release of macrophage aggregation factor. Positive results were obtained which correlated with periods of overt disease activity. Similar results were observed in patients with classical rheumatoid arthritis manifesting destructive articular changes. This study suggests that cartilage antigenic components may facilitate perpetuation of cartilage inflammation by cellular immune mechanisms.

Adult↗