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Biomedical subjects

P Beck

Publications and source records attributed to P Beck.

At least 91 records · Page 5Linked to original sources
PubMed1983

Plasma levels of beta-thromboglobulin and factor VIII-related antigen in diabetic children and adults.

In order to investigate the relationship between the in vivo platelet activation in diabetes mellitus and the endothelial damage connected with the diabetic micro- and/or macroangiopathy, plasma levels of beta-thromboglobulin (B-TG) and of factor VIII-related antigen (VIII R:Ag) were studied (1) in juvenile-onset (Type I) diabetics without clinical signs of angiopathy (age under 12 years) and (2) in mostly maturity-onset (Type II) diabetics with and without overt angiopathy (age between 14 and 60 years). Normal controls and nondiabetics with atherosclerosis were also studied. Plasma levels of both proteins were found to be elevated in all the groups of diabetic and atherosclerotic patients in comparison with the controls. Highest levels were found in adult diabetics with angiopathy and in atherosclerotics even without diabetes, but values of the diabetic children were also elevated. The data suggest a causal relationship between the vascular damage and the enhanced platelet reactivity in which the former may play the primary role.

Adolescent↗
PubMed1982

Synergistic effect of human relaxin and progesterone on human myometrial contractions.

In an in vitro human myometrial strip system, both relaxin and progesterone can independently decrease the amplitude of spontaneous myometrial contractions. However, progesterone and relaxin synergize in this action. Doses of relaxin and progesterone which independently are ineffective, together inhibit myometrial contraction amplitude. Relaxin and progesterone are both products of the corpus luteum, a structure necessary for early pregnancy maintenance. The synergistic action of relaxin and progesterone in vitro suggests a similar in vivo physiologic effect in establishing uterine quiescence.

Adult↗
PubMed1981

Induction of a lymphotoxin-like mediator in peripheral blood and synovial fluid lymphocytes by incubation with synovial fluid from patients with rheumatoid arthritis.

A significantly increased spontaneous cell-mediated cytotoxicity (SCMC) has been reported in synovial fluid lymphocytes (SFL) as compared to peripheral blood lymphocytes (PBL) of patients with rheumatoid arthritis (RA) and that of normal controls [1-3]. To determine whether this increased SCMC activity is due to the production of a lymphokine and related to the production of a lymphotoxin(LT)-like mediator, PBL from normal controls and PBL and SFL from RA patients were incubated either with a human melanoma cell line (IGR 3) or with cell-free synovial fluid (SF) from RA patients. The SF and the cell-free supernatants of the different cultures were tested for LT activity by estimation of inhibition of DNA synthesis of HeLa cell monolayers and they were added to a SCMC assay system using normal PBL and IGR 3 as target. In the supernatants from cocultures of either PBL from controls or PBL and SFL from RA patients with IGR 3 cells, there was no significant difference in LT activity. An LT-like mediator was observed in the supernatants of all lymphocytes cocultured with SF, whereas SF alone and supernatants of lymphocytes alone exhibited little or no LT activity. In a control experiment, LT induction was not observed when normal lymphocytes were cultured with the serum of RA patients. Absorption of the culture supernatants with an insolubilised goat anti-human Ig did not remove LT activity. The demonstrated release of an LT-like mediator from lymphocytes incubated with SF might be one contributing mechanism to the inflammatory joint reaction in RA patients.

Arthritis, Rheumatoid↗
PubMed1981

Hormone secretion by monolayer cultures of human luteal cells.

To be able to study the control mechanisms for human luteal function, a system was designed to maintain human luteal cells in culture. Collagenase dispersed cells of human corpora lutea of the menstrual cycle and pregnancy were maintained as monolayer cultures for 26 days. Progesterone (P) and relaxin (R) in culture media were measured by radioimmunoassay. Both menstrual cycle and pregnancy luteal cells secreted P for 26 days. hCG increased P secretion by menstrual cycle luteal cells, but not by pregnancy luteal cells. R was not detected in media of menstrual cycle luteal cell controls, nor in media of cells incubated with hCG. R was detected in media of pregnancy luteal cells for 6 days. Addition of hCG caused a significant increase in media R levels only on day 2 of culture. These studies show that human luteal cells can be maintained as viable monolayer cultures for at least 26 days and these cultures can be used to study control of human luteal function.

Cells, Cultured↗
PubMed1981

Autologous and allogeneic MLC-reactivity in patients with rheumatoid arthritis.

In vitro interaction of autologous peripheral blood and synovial fluid lymphocytes was studied using isolated lymphocytes from 15 patients with rheumatoid arthritis. In the applied one way mixed lymphocyte cultures (MLC) a significant proliferative response was obtained when peripheral blood lymphocytes were cultured with mitomycin treated synovial fluid cells. In contrast, when the reverse situation was examined, only a marginal stimulation of synovial fluid lymphocytes by peripheral blood lymphocytes was recorded. Studies on the effect of macrophage depletion on the autologous MLC made in unlikely that the decreased proliferative response of SFL was due to the presence of a monocyte suppressor cell population in SFL. Likewise no evidence could be obtained that the decreased MLC response of SFL to autologous and allogeneic lymphocytes was caused by the predominance of short lived T-suppressor cells in the synovial fluid.

Arthritis, Rheumatoid↗
PubMed1980

Hypothalamic sarcoidosis and hypopituitarism.

4 patients with presumed pituitary hypothalamic sarcoidosis are described. 3 had histological diagnoses compatible with sarcoidosis and in the other this diagnosis was strongly suspected from chest X-rays. 2 patients presented with diabetes insipidus. ACTH reserve was diminished in 3 out of 4 and growth hormone reserve was diminished in the 3 who were tested. All 4 patients developed secondary amenorrhea. 3 patients had hypothalamic hypothyroidism. Prolactin dynamics were intact. Tomograms of the sella turcica in all 4 and computerized tomography of the hypothalamic area in 2 patients failed to reveal any abnormality.

17-Hydroxycorticosteroids↗
PubMed1979

Peripheral blood lymphocyte subpopulations in multiple myeloma.

Antisera raised against idiotypic determinants of myeloma proteins and macroglobulins have been used to differentiate peripheral blood lymphocytes populations from individual patients. I.D.-positive lymphocytes not resembling plasma cells have been regularly found in peripheral blood in these diseases. This lymphocyte population is heterogeneous with respect to non-tumor-specific surface markers, such as SRBC-, Fc- and C-receptors. Tumor specific idiotypic determinants will thus allow a more correct recognition of the total tumor cell compartment in these diseases.

Animals↗
PubMed1979

Environmental determinants of memory improvement in late adulthood.

Two studies were conducted with nursing home residents to determine whether memory could be improved. This was accomplished by increasing the cognitive demand of the environment and then varying the extent to which residents were motivated to attend to and remember these environmental factors. In Study 1, motivation to practice recommended cognitive activities was manipulated by varying the degree of reciprocal self-disclosure offered by interviewers in a series of dyadic interactions. In Study 2, motivation to practice recommended cognitive activities was manipulated by varying whether positive outcomes were contingent on attending to and remembering these activities, which increased in demand over time. Whether as a function of interpersonal (Study 1) or practical (Study 2) incentives, engaging in cognitive activity resulted in improvement on standard short-term memory tests, including probe recall and pattern recall, as well as in improvement on nurses' ratings of alertness, mental activity, and social adjustment for experimental groups relative to controls.

Aged↗