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Biomedical subjects

J Cohen

Publications and source records attributed to J Cohen.

At least 1,369 records · Page 76Linked to original sources
PubMed1982

Activation of retinal tyrosine hydroxylase: tolerance induced by chronic treatment with haloperidol does not modify response to light.

A single dose of haloperidol administered to rats in the dark increases the activity of retinal tyrosine hydroxylase. The ability of haloperidol to activate the enzyme is diminished 24 hr after terminating 22 to 30 days of treatment with haloperidol. The retinal enzyme is also tolerant to activation by treatment with chlorpromazine. In contrast, exposure of the animals to light activates the enzyme to the same extent in chronic haloperidol-treated and control animals. Thus, chronic haloperidol treatment does not modify the ability of the retinal enzyme system to respond to the physiological stimulus, light. Apparently, activation of retinol tyrosine hydroxylase by haloperidol and light occurs by independent mechanisms.

Animals↗
PubMed1982

Infection and immunosuppression. A study of the infective complications of 75 patients with immunologically-mediated disease.

We have studied the infective complications in a group of 75 patients with immunologically-mediated disease who required high dose immunosuppression. There were 22 patients with anti-glomerular basement membrane antibody disease, 19 patients with systemic lupus erythematosus, 18 with wegener's granulomatosis and 16 patients with other forms of systemic vasculitis. The infection rate was 3.69 infections/patient, or 0.74 infections/patient/week of immunosuppression. Bacteria were the commonest infecting organisms (76.1 per cent); serious opportunist viral and fungal infections were less frequent (10.7 per cent) but opportunist pneumonias were an important cause of death. Sixteen patients died (21 per cent) and in 10 of these (62.5 per cent) death was considered to be primarily due to infection. Analysis of six aspects of host susceptibility to infection (age, renal function, dose of prednisolone, cyclophosphamide and azathioprine, and number of plasma exchanges) revealed no single factor as predisposing to infection in the whole group, but in 23 patients who suffered severe infective complications, renal impairment and increasing doses of prednisolone were associated significantly, particularly in combination (p = 0.06). Cyclophosphamide was associated with infection only in the presence of neutropenia, which was rare (13 infections in nine patients). The duration of plasma exchange was not related to the frequency of infection. Fifty patients needed an arteriovenous shunt to provide vascular access for haemodialysis or plasma exchange, and septicaemia occurred in 13; only two episodes of septicaemia were seen in patients without a shunt.

Adolescent↗
PubMed1981

The role of the midbrain in courtship behavior of the female ring dove (Streptopelia risoria): evidence from radiofrequency lesion and hormone implant studies.

The involvement of the nucleus intercollicularis (ICo) region of the midbrain, an estrogen-sensitive area, in the expression of estrogen-dependent female courtship behavior was examined with radiofrequency lesion and intracranial hormone implant techniques. Bilateral lesions in the ICo region caused a reduction in the female's nest coos, and no reduction in other behaviors in response to male courtship. In addition, the follicles of the ICo lesioned females failed to grow in response to male courtship. A second experiment showed that the difference in follicular size between ICo-lesioned and sham-ICo-lesioned females was not observed if females were visually isolated from males, suggesting that tonic ovarian activity was not affected by ICo lesions. In the third experiment, unilateral 30-gauge implant containing estrogen (E) or estradiol benzoate (EB) in the ICo region of bilaterally ovariectomized females restored the nest-coo, though not to the level obtained with systemic EB injections. Other behaviors were not selectively affected by E or EB implants in the ICo region. Diffusion from the implant was probably not responsible for the elicitation of the nest-coo, since the oviduct weights of females implanted with E or EB and cholesterol did not differ. These data are consistent with the hypothesis that the ICo region is involved in the expression of vocal (cooing) courtship behavior in the female ring dove.

Animals↗
PubMed1981

Hamilton Depression Rating Scale. Extracted from Regular and Change Versions of the Schedule for Affective Disorders and Schizophrenia.

Investigators who wish to use new procedures usually wish to relate their results to those already in the literature. This often results in the use of both old and new measures. The Schedule for Affective Disorders and Schizophrenia Regular and Change Versions (SADS and SADS-C) have advantages over the widely used Hamilton Depression Rating Scale (HDRS). A procedure was developed to extract the HDRS score from the SADS and SADS-C. The comparative reliability and the validity of the extracted HDRS score as a substitute for a real HDRS score was established. The SADS-C and the HDRS were completed by the raters for 48 subjects. The correlation between the extracted and real HDRS scores was positive and large.

Adolescent↗
PubMed1981

A preliminary investigation on time perception and autonomic self-regulation.

This study sought to examine how perception of time duration was affected by two autonomic self-regulation treatment procedures: a biofeedback/self-regulation treatment program and a relaxation response treatment program. Time experience was assessed in two ways: time interval estimation during an actual treatment session (N = 5, in each of the two groups) and subjective reporting (all 10 subjects in each group were evaluated). During an actual relaxation/self-regulation session, patients overestimated time duration and, retrospectively, patients in the group that learned to reduce blood pressure experienced time as slowing, whereas participants in the other treatment program experienced time a passing "normally" during the treatment sessions. All subjects reported that they usually experienced time as passing "normally" or corresponding to clock time. These results raise the question as to whether the experience of temporal slowing may be an important component of the psychological experience of the patients that allows autonomic learning to occur. Further research in this area is recommended and briefly discussed.

Adult↗
PubMed1981

Monoclonal antibody with specificity for monocytes and neurons.

We have characterized a monoclonal antibody, called UC45, that reacts with both monocytes and neurons. It was derived from a fusion of the NS-1 plasmacytoma cell line with spleen cells from a mouse immunized with human acute monoblastic leukemia cells. The antibody reacts weakly with viable monocytes in suspension but has specificity for fibrous projections, which are found on monocytes that have adhered to substrate. Other hemopoietically derived cells such as granulocytes and lymphocytes, and many tissue-culture lines, do not react with UC45 by cell-surface immunofluorescence. Similarly, UC45 reacts with the processes of both viable CNS and PNS neurons in tissue culture but with no other neural-tissue-derived cells. The monoclonal antibody has interspecies reactivity, in that it reacts with human, rat and mouse monocytes and neurons. The monocytes and neuronal antigen is present predominantly on a protein of 45 kd. Attempts to identify this protein on monocytes with conventional heteroantisera directed against fibronectin, complement components, fibrinogen, collagen, tubulin and actin have failed. A monoclonal antibody has therefore allowed identification of an antigen, unexpectedly shared by monocytes and neurons. The fact that it is found on cell processes of both cell types suggests that it may be performing some similar function for these cells, whose other activities differ substantially.

Animals↗