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Biomedical subjects

A D Cohen

Publications and source records attributed to A D Cohen.

71 records · Page 4Linked to original sources

Lymphokine responses to concanavalin A stimulation: association with HLA DR antigens.

Stimulation of human lymphocytes with concanavalin A (Con A) resulted in variable lymphokine responses as indicated by factors inhibiting macrophage migration (MIF) or stimulating macrophage migration (MStF), or resulted in negligible responses. These responses were consistent for a given individual when repeated after several months. MIF responses were observed more frequently than MStF responses in patients with renal failure who had demonstrable alloantibodies. MStF responses were statistically associated with the presence of HLA DR1 antigens in patients with renal failure and two separate groups of healthy individuals, while MIF responses were associated with DR7 in the three groups studied. There was no correlation between immunoglobulin allotypes and lymphokine responses. These results suggest that lymphokine responses to Con A are indicators of nonspecific immunological responsiveness and are influenced by genes associated with the major histocompatibility complex.

Adolescent↗

Pneumonia in renal transplant patients.

Between January 1976 and March 1982, 28 episodes of pneumonia occurred in 26 renal transplant patients. The overall mortality rate was 46%. Of the 16 patients with nosocomial pneumonia 9 (56%) died, whereas of the 12 patients with community-acquired pneumonia 4 (33%) died. In all 9 cases of unknown cause the response to empiric treatment was prompt, whereas in 4 of the 10 cases of monomicrobial pneumonia and 8 of the 9 cases of polymicrobial pneumonia the patient died. Cytomegalovirus was the sole cause of the pneumonia in two patients and a contributing cause, along with aerobic gram-negative bacteria, in another five, four of whom also had a fungal infection. Two patients, both of whom survived, had nosocomial Legionnaires' disease.

Adult↗

Lymphokine responses to mitogenic and antigenic stimulation. Predictive value in renal transplantation.

Immune responsiveness of recipients of renal transplants from cadaver donors was monitored by measuring lymphokine responses to specific (donor antigen) and nonspecific (concanavalin A (Con A)) stimuli. Production of migration inhibition factor (MIF) in response to stimulation by Con A before and 3 days after transplantation correlated strongly with graft rejection and production of migration stimulation factor (MSTF) with graft acceptance. This pattern continued at later time intervals but was more variable. An initial vigorous MIF response to donor cell extract was associated with rejection but subsequent responses to donor extract in the 1st month after transplantation were variable and not predictive of the outcome. In some cases, there was clearly a dissociation of lymphokine responses to donor-specific and nonspecific stimuli.

Animals↗

Cardiac function in end-stage renal disease.

To assess cardiac status in end-stage renal disease, we compared clinical, ECG, and echocardiographic data from 37 patients on maintenance hemodialysis with data from 42 patients with functioning renal transplants. Cardiovascular symptoms and abnormal cardiovascular findings were more common in dialysis-maintained patients than in those with transplants. Follow-up studies indicated that despite a high prevalence of cardiac symptoms, abnormal physical signs, and dilated left ventricles among patients with end-stage renal disease, systolic left ventricular function was generally well preserved irrespective of renal failure therapy. Compared with maintenance hemodialysis, however, successful renal transplantation is associated with an overall enhancement of cardiac status, the majority of which is probably secondary to transplant-associated improvement in hemoglobin level and control of intravascular volume.

Adolescent↗

On the mechanism of lithium-induced diabetes insipidus in man and the rat.

The mechanism of lithium-induced diabetes insipidus was investigated in 96 patients and in a rat model. Polydipsia was reported by 40% and polyuria (more than 3 liter/day) by 12% of patients receiving lithium. Maximum concentrating ability after dehydration and vasopressin was markedly impaired in 10 polyuric patients and was reduced in 7 of 10 nonpolyuric patients studied before and during lithium therapy. Severe polyuria (more than 6 liter/day) was unresponsive to trials of vasopressin and chlorpropamide, but improved on chlorothiazide. Rats receiving lithium (3-4 meq/kg/day) developed massive polyuria that was resistant to vasopressin, in comparison to rats with comparable polyuria induced by drinking glucose. Analysis of renal tissue in rats with lithium polyuria showed progressive increase in the concentration of lithium from cortex to papilla with a 2.9-fold corticopapillary gradient for lithium. The normal corticopapillary gradient for sodium was not reduced by lithium treatment. The polyuria was not interrupted by brief intravenous doses of vasopressin (5-10 mU/kg) or dibutyryl cyclic AMP (10-15 mg/kg) capable of reversing water diuresis in normal and hypothalamic diabetes insipidus rats (Brattleboro strain). The present studies suggest that nephrogenic diabetes insipidus is a common finding after lithium treatment and results in part from interference with the mediation of vasopressin at a step distal to the formation of 3',5' cyclic AMP.

Animals↗

An artificial lung.

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Anesthesia, Inhalation↗

Calcium channel blockers intake and psoriasis: a case-control study.

In vitro evidence suggests that intracellular calcium metabolism influences keratinocyte differentiation. However, only a few reports have described exacerbation of psoriasis or psoriasiform eruptions due to intake of calcium channel blockers. We conducted a case-control study to evaluate the association between exposure to calcium channel blockers and psoriasis. Data were obtained through a retrospective assessment of the files of 150 patients hospitalized for psoriasis or psoriasiform eruptions and 150 matched control patients. Exposure to calcium channel blockers was recorded in case and control patients. It was found that 13/150 patients hospitalized for psoriasis consumed calcium channel blockers. Calcium channel blockers were associated with precipitation of new-onset psoriasis (n = 2), as well as with the exacerbation of psoriasis (n = 11). The calcium channel blockers were as follows: nifedipine (n = 10), felodipine (n = 2) and amlodipine (n = 1). The median latent period between the beginning of intake of calcium channel blockers and precipitation or exacerbation of psoriasis was 28 months (range 4-143 months). A stepwise multivariate logistic regression analysis demonstrated that intake of calcium channel blockers was significantly associated with psoriasis, as compared to the control group (p = 0.018). Our study implies a possible role of calcium channel blockers as precipitating or exacerbating factors in patients with psoriasis.

Acute Disease↗

CA 15-3, mucin-like carcinoma-associated antigen and tissue polypeptide-specific antigen: correlation to disease state and prognosis in breast cancer patients.

Serum testing for the tumor markers CA 15-3 and mucin-like carcinoma-associated antigen (MCA) was performed in 144 patients with breast cancer. Of those patients, 127 were also tested for a third tumor marker, tissue polypeptide-specific antigen (TPS). At the time of testing, 73 patients (51%) were without evidence of disease and 71 patients (49%) had active disease. Mean follow-up time was 16 months. Positivity rates were: 29.8% for CA 15-3, 47.2% for MCA, and 58.3% for TPS. Mean value for patients with no evidence of disease as compared to patients with active disease was 21 U/ml and 117 U/ml for CA 15-3 (P = 0.001), 10.2 kU/l and 22.6 kU/l for MCA (P = 0.001), and 148 U/l and 310 U/l for TPS (P = 0.02). Two year actuarial survival, according to values below and above an established cutoff for CA 15-3 were 80% and 31% (P < 0.001), 75% and 45% for MCA (P < 0.01), and 82% and 50% for TPS (P < 0.01). We conclude that CA 15-3, MCA and TPS values reflect disease state and prognosis in breast cancer patients.

Adult↗