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S Cohen

Publications and source records attributed to S Cohen.

At least 577 records · Page 32Linked to original sources
PubMed1988

Psychosocial models of the role of social support in the etiology of physical disease.

Although there has been a substantial effort to establish the beneficial effects of social support on health and well-being, relatively little work has focused on how social support influences physical health. This article outlines possible mechanisms through which support systems may influence the etiology of physical disease. I begin by reviewing research on the relations between social support and morbidity and between social support and mortality. I distinguish between various conceptualizations of social support used in the existing literature and provide alternative explanations of how each of these conceptualizations of the social environment could influence the etiology of physical disease. In each case, I address the psychological mediators (e.g., health relevant cognitions, affect, and health behaviors) as well as biologic links (e.g., neuroendocrine links to immune and cardiovascular function). I conclude by proposing conceptual and methodological guidelines for future research in this area, highlighting the unique contributions psychologists can make to this inherently interdisciplinary endeavor.

Adaptation, Psychological↗
PubMed1988

Expression of human epidermal growth factor precursor cDNA in transfected mouse NIH 3T3 cells.

Stable cell lines expressing the human epidermal growth factor (EGF) precursor have been prepared by transfection of mouse NIH 3T3 cells with a bovine papillomavirus-based vector in which the human kidney EGF precursor cDNA has been placed under the control of the inducible mouse metallothionein I promoter. Synthesis of the EGF precursor can be induced by culturing the cells in 5 mM butyric acid or 100 microM ZnCl2. The EGF precursor synthesized by these cells appears to be membrane associated; none is detectable in the cytoplasm. The size of the EGF precursor expressed by these cells is approximately 150-180 kDa, which is larger than expected from its amino acid sequence, suggesting that it is posttranslationally modified, presumably by glycosylation. The EGF precursor was also detected in the conditioned medium from these cells, indicating that some fraction of the EGF precursor synthesized by these transfected cells may be secreted. Preliminary data suggest that this soluble form of the EGF precursor may compete with 125I-labeled EGF for binding to the EGF receptor. These cell lines should be useful for studying the processing of the EGF precursor to EGF as well as determining the properties and possible functions of the EGF precursor itself.

Animals↗
PubMed1988

Vaccination trials in rhesus monkeys with a minor, invariant, Plasmodium knowlesi 66 kD merozoite antigen.

A minor Plasmodium knowlesi 66 kD antigen, which plays an essential role in merozoite invasion, has been shown to be stable in distinct variants and strains of the parasite, and in the face of a specific immune response from the host. Parasites were unable to produce novel molecule(s) to replace it functionally, even in the presence of specific immune pressure. Rhesus monkeys immunized with the purified 66 kD antigen, with saponin as adjuvant, produced antibody which inhibited merozoite invasion of red cells in vitro. Four out of six immunized rhesus monkeys demonstrated clinically effective immunity when challenged at a time of known or presumed high inhibitory antibody titre. When immunization failed to protect, it was ascribed to insufficient levels of specific antibody attributable either to a suboptimal dose of antigen or the use of an inadequate adjuvant.

Animals↗
PubMed1988

Kinetics of choline uptake into isolated rat forebrain microvessels: evidence of endocrine modulation.

The active uptake of [methyl-3H]choline into isolated rat brain microvessel suspension was studied as a likely guide to the transport of choline across the blood-brain barrier. The method consisted primarily of incubation of the suspension with a fixed concentration of labeled choline in the presence of increasing concentrations of unlabeled choline or any other inhibitor (I) of active uptake, defined as the difference in uptake at 37 degrees and 0 degrees C. From the linear regression of (1/V) against [I], the following values of Vmax (nmol g-1 min-1) and Km (microM) were obtained for choline: 2-month-old males, 10.6 +/- 3.8 and 6.1 +/- 0.9; 3-month old random females, 28.4 +/- 5.9 and 12.6 +/- 4.0; females at metaestrus, 17.8 +/- 10.3 and 8.3 +/- 5.0; at diestrus, 31.1 +/- 9.3 and 13.0 +/- 2.6; at proestrus, 54.9 +/- 2.2 and 14.0 +/- 1.5; at estrus, 19.2 +/- 2.2 and 2.6 +/- 1.7. The differences between males and random females (p less than 0.018) and between females at proestrus and estrus (p less than 0.005) are significant. It is suggested that these inter- and intrasex variations in choline uptake reflect a dynamic adjustment of supply in accordance with brain demand for choline at the time of assay. Hemicholinium-3 was an effective inhibitor of choline uptake, Ki = 14.0 +/- 8.5 microM; dimethylaminoethanol was much less effective; and imipramine had no measurable effect.

Animals↗
PubMed1988

Swallowing disorders.

Swallowing is a coordinated activity that enables solids and liquids to pass uninterruptedly from the mouth to the stomach. Dysphagia occurs when this process is disrupted by organic or functional alterations at the level of swallow initiation or esophageal emptying. The differential diagnosis includes obstructive lesions and motility disorders. Symptoms and clinical features help distinguish these diseases.

Deglutition Disorders↗
PubMed1988

Sites of action of mu-, kappa- and sigma-opiate receptor agonists at the feline ileocecal sphincter.

The sites of action of several opiate agonists at the feline ileocecal sphincter (ICS) were studied. Dose-response curves for the relatively specific ligands for the mu-, kappa-, and sigma-receptors were determined using morphine (mu-receptors), dynorphin-(1-13) (kappa-receptors), and N-allylnormetazocine (sigma-receptors). Each agonist results in a contractile ICS response. The ICS responded stereospecifically to the levo-isomer of N-allylnormetazocine. Atropine (30 micrograms/kg) or naloxone (100 micrograms/kg) antagonized the ICS response to morphine and to (-)-N-allylnormetazocine. Higher doses of naloxone were required to inhibit the ICS response to dynorphin. Neither atropine nor tetrodotoxin inhibited the ICS response to dynorphin. The ICS response to dynorphin was enhanced after tetrodotoxin. Morphine tachyphylaxis inhibited the ICS response to (-)-N-allylnormetazocine and vice versa. The ICS response to morphine was unaffected by vagotomy but inhibited by trimethaphan camsylate. This study suggests that dynorphin (kappa-receptor) acts at a smooth muscle receptor to mediate contraction and a neural receptor to mediate relaxation, while (-)-N-allylnormetazocine acts at the ICS via a mu-receptor. mu-Receptor activation causes ICS contraction via a cholinergic pathway.

Animals↗
PubMed1988

Neuropeptide responses and mechanics of the proximal and distal feline colon in vitro.

Mechanical properties and responses to neuropeptides were compared for proximal and distal feline colonic muscle. Proximal longitudinal (PL), proximal circular (PC), distal longitudinal (DL), and distal circular (DC) muscles were studied in vitro under isometric conditions. Total tension in DL [1.636 +/- 0.009 (SE) kg/cm2] was greater than in DC (0.699 +/- 0.004 kg/cm2) or PC (0.710 +/- 0.005 kg/cm2, P less than 0.05). Longitudinal muscle developed proportionately more active tension than circular muscle at each region (80.9% in DL vs. 54.1% in DC and 77.1% in PL vs. 52.3% in PC, P less than 0.01). Neuropeptides varied in potency and efficacy. Cholecystokinin octapeptide (CCK-8) was the most potent and efficacious in PL and substance P was the most efficacious in PC muscle (P less than 0.05). Substance P was more efficacious whereas CCK-8 and neurotensin were less efficacious in PC than PL muscle (P less than 0.01). DL muscle did not respond to CCK-8. DC muscle did not respond to CCK-8 or neurotensin. Isometric contractions to each neuropeptide were insensitive to tetrodotoxin. We conclude that 1) mechanical properties of circular and longitudinal colonic muscle differ and 2) responses to neuropeptides depend on anatomic region and intrinsic properties.

Acetylcholine↗
PubMed1988

DST results in nonpsychotic depressed outpatients.

In two studies using the dexamethasone suppression test (DST) to evaluate the efficacy of newer antidepressants in depressed outpatients, the authors found a DST nonsuppression rate of 13% (11 of 86 patients). Thirty-three of the DST suppressors received an antidepressant and 42 received placebo; the drug-treated group showed a significant therapeutic response. The low rate of DST nonsuppression in these depressed outpatients, a finding consistent with that of other investigators, does not confirm or refute reports that these patients are relatively resistant to placebo in comparison with active medication. The authors recommend that DST results not be used as selection criteria in studies assessing newer therapies for depressed outpatients.

Adult↗
PubMed1988

Interferon alfa-n1 (Wellferon) in juvenile onset recurrent respiratory papillomatosis: results of a randomized study in twelve collaborative institutions.

Sixty-six patients with clinically severe juvenile-onset recurrent respiratory papillomatosis (RRP) were entered into a 12-month randomized crossover study to evaluate interferon alpha-n1 Wellferon (WFN) as an adjuvant to CO2 laser surgical excision. Eligibility required disease onset to be before age 16, and an endoscopic excision requirement of at least three operations in the 6 months immediately prior to entry. Patients were randomized to Observation versus WFN at a dose of 5 MU/m2 daily for 28 days and three times weekly for 5 months. The patient groups were comparable in extent of disease at entry. Total extent of disease was determined by a composite score derived from the number of diseased anatomic sites and extent of surface area and lumen encroachment present at each site. Standard endoscopic excisions were performed every 2 months and clinical courses compared on a basis of composite scores determined at each endoscopy. Statistically significant improvement occurred in the patient group which received WFN. We conclude that interferon alpha n-1 is an effective adjuvant to surgery in RRP management.

Adolescent↗
PubMed1988

Detection of specific beta-globin mutations in Kurdish Jews with beta-thalassemia.

Patients with beta-thalassemia, of Kurdish extraction, were screened for the presence of two mutations, in the TATA box and in codon 44, previously discovered in this ethnic isolate. Of the 56 chromosomes analyzed, 13 were found to carry the TATA box mutation and 17 the codon 44 mutation. The result of this work provides a basis for a more efficient prenatal diagnosis program for this community.

Adolescent↗
PubMed1988

Peripheral retinal neovascularization and rubeosis iridis after a bilateral circular buckling operation.

This report describes a young high-myopic patient who developed rubeosis iridis with peripheral retinal neovascularization one year after a circular buckling operation. Subsequently, vitreous bleeding and exudation led to traction retinal detachment which was treated successfully by anterior vitrectomy and cryopexy. It is suggested that this case represents a mild form of anterior-segment ischemia, combined with peripheral retinal ischemia.

Child↗
PubMed1988

MRI and in vivo proton spectroscopy of the lesions of the globe.

MRI proved very valuable in the diagnosis of intraocular lesions. In this report, uveal melanomas, the most common intraocular tumors in adults, were seen as hyperintense lesions on T1W and PW images and as hypointense lesions on T2W images. MRI is not accurate for diagnosis when the melanoma is smaller than 3 mm. Associated retinal detachment as well as necrotic or hemorrhagic changes within the uveal melanoma can be identified by MRI. Choroidal metastasis may be difficult to differentiate from uveal melanoma. Choroidal hemangioma and hematoma often can be differentiated from uveal melanoma. Early experience with in vivo proton MR spectroscopy has the potential for obtaining biochemical information, thus enhancing the diagnostic sensitivity of MR studies. Future work on combined MRI with MR in vivo spectroscopy is needed to characterize abnormal conditions according to their patterns and for identification of tumor markers. A differential diagnosis list for ocular (globe) lesions can be found in the introduction to this issue. A discussion of the majority of the ocular lesions listed can be found in either this article or the article on congenital/pediatric lesions (Hopper et al) of the orbit, also in this issue.

Diagnosis, Differential↗
PubMed1988

Visual acuity, strabismus, and amblyopia in premature babies with and without retinopathy of prematurity.

One hundred eighty-seven premature babies, 48 of whom suffered from retinopathy of prematurity (ROP), were examined. A higher incidence of strabismus was found in the group with cicatricial ROP (23% vs. 9%). Amblyopia was present in 6% of the ROP group and in only 1.4% of babies without ROP. Myopia was found in 50% of the ROP group as compared with 15% in the nonROP group. Astigmatism and anisometropia were more common in the ROP group, but hypermetropia was equally represented in both groups.

Age Factors↗
PubMed1988

Personal experience with an alternate incision for parotidectomy.

The paramount consideration in incision for parotidectomy is adequate exposure to facilitate preservation of the facial nerve and complete excision of a tumor, if present. The classic incision passed through the anterior neck, leaving a scar which is readily apparent and of considerable concern to some patients. Presented here is a modification of the rhytidectomy incision to allow for wide and good exposure of the operative field, while at the same time leaving scars which are much more acceptable. Allowance is made to add to or modify the incision as necessary, depending on the position of tumor and extent of required resection. Examples of the use of the incision are presented, demonstrating both the degree of operative exposure and postoperative cosmetic appearance.

Cicatrix↗
PubMed1988

Psychotic and nonpsychotic depression: comparison of response to ECT.

The charts of 46 patients who underwent ECT in a teaching hospital between 1980 and 1986 were reviewed. All patients were suffering from major depression, with or without psychotic features, and were resistant to pharmacotherapy. Response to ECT was compared between those with psychotic features (N = 27) and those without psychotic features (N = 19). Both groups had equal and effective response to ECT. Therefore, the presence of psychotic features was not significant in predicting response to ECT.

Delusions↗
PubMed1987

Selective targeting of boronophenylalanine to melanoma in BALB/c mice for neutron capture therapy.

Melanoma cells actively accumulate aromatic amino acids for use as precursors in the synthesis of the pigment melanin. Using the Harding-Passey melanoma carried s.c. in BALB/c mice, we have demonstrated that p-boronophenylalanine (BPA) is taken up by melanoma tissue to a much greater extent than by normal tissues. Following a single i.p. injection, or a series of injections given over 1 h, the accumulation of boron in melanoma was found to be transient, reaching a maximum approximately 6 h postinjection. The concentrations of boron achieved in tumor ranged from 9-33 micrograms/g, and are within the range estimated to be necessary for successful application of the nuclear reaction 10B(n,alpha)7Li for neutron capture therapy. Boron concentrations in tumor and tissues were determined using either a prompt-gamma spectroscopic technique or by quantitative neutron capture radiography using whole-body sections. Distribution studies with the resolved stereoisomers of BPA indicated that the L isomer is preferentially accumulated in the melanoma compared to the D isomer. The L isomer of BPA was shown to be targeted to actively dividing tumor cells by simultaneously comparing the boron and [3H]thymidine distribution in tumor. Under conditions which selectively deliver high concentrations of boron to Harding-Passey melanomas in BALB/c mice, BPA did not deliver useful concentrations of boron to a mammary adenocarcinoma in Hale-Stoner mice. These results, along with the selectivity of the Harding-Passey melanoma for the L isomer of BPA, are consistent with our working hypothesis that BPA is actively transported into the melanomas as an analogue of natural melanin precursors.

Animals↗