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Biomedical subjects

J Cohen

Publications and source records attributed to J Cohen.

At least 1,225 records · Page 68Linked to original sources
PubMed1986

Kainic acid depletes retinal phenylethanolamine-N-methyltransferase activity of rats.

Kainic acid, an excitotoxic agent to the retina as well as to neuronal cell bodies in the brain, was administered intraocularly to rats in order to study the sensitivity of phenylethanolamine-N-Methyltransferase (PNMT) containing amacrine cells to this agent. Results show that these cells are very sensitive to the toxic effects of kainate. A dose of 5 nmoles caused a significant reduction in retinal PNMT activity. Higher doses further depleted enzyme activity.

Animals↗
PubMed1986

Suramin antiviral therapy in the acquired immunodeficiency syndrome. Clinical, immunological, and virologic results.

The human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) requires reverse transcriptase for viral replication. We treated 12 patients who had acquired immunodeficiency syndrome and active HTLV-III/LAV viremia with suramin, a potent competitive inhibitor of reverse transcriptase, in six weekly induction doses of 1 g, followed by weekly maintenance doses of 500 mg. Three of eleven evaluable patients had complete inhibition of viral reverse transcriptase levels, lasting at least 18 weeks in each. Two additional patients had marked reduction in reverse transcriptase activity. Nadir serum suramin levels at the end of the induction phase correlated with the level of reverse transcriptase reduction. Toxicity included hepatic transaminase elevation, fever, malaise, rash, proteinuria, paresthesias, reversible neutropenia, and adrenal insufficiency. Objective clinical improvement was documented in 1 patient, but no patient had improvement in immune function and 7 patients had recurrent opportunistic infections. Although suramin may suppress HTLV-III/LAV viremia, its significant toxicity and lack of effect on immune variables indicate that alternative therapy will be required.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Primal repression: clinical and theoretical aspects.

Primal repression, long an obscure and unusable concept, has been given a precise place in a recent re-working of the theory of repression (Cohen & Kinston, 1984); and this paper specifically examines its properties and presentation. Primal repression refers to an absence of psychic structure which can be made good in the process of emotional growth. It is a part of the mind where trauma persists; and it has a close connexion to the unrepressed unconscious. Direct emergence of primal repression is a threat to life and its activation is therefore risky. During psychoanalysis, primal repression is normally avoided by object-narcissism buttressed by neurotic defences, but it may be reached and worked with in the presence of a non-internalizable valuing and nurturing relationship which we label 'primary relatedness'. This relation is therefore the interactional context for emotional growth. Numerous clinical examples are provided to demonstrate characteristic features of this region of the mind as seen in psychoanalyses. Vignettes illustrate the experiences of patient and analyst as primary relatedness is established; the consequent re-emergence of traumatic states and unmet needs, often initially in the form of severe physical and psychological deterioration; primitive forms of symbolization in the course of repairing primal repression; and the role of action in emotional growth.

Adult↗
PubMed1986

Differential expression of cell surface antigens and glial fibrillary acidic protein in human astrocytoma subsets.

We have characterized five distinct cell surface antigens of human astrocytomas and correlated their expression with the expression of glial fibrillary acidic protein (GFAP) and four previously defined cell surface markers of astrocytomas. One of the newly studied antigens, A4, which was originally detected on rat central nervous system (but not peripheral nervous system) neurons, is expressed on GFAP+ human astrocytoma cells, but not on GFAP- astrocytomas or a wide range of other neuroectodermal, epithelial, and hematopoietic cells. Antigens F19 (Mr 140,000/90,000 glycoprotein) and F24 (Mr 90,000 glycoprotein) also show restricted distribution and are expressed on subsets of neuroectodermal and mesenchymal cells. Antigens G253 (Mr 95,000 glycoprotein) and S5 (Mr 120,000 glycoprotein) are more widely distributed on the cultured cell panel. The distribution of these antigens was determined on a series of 22 astrocytoma cell lines and in normal brain tissue and the results were compared with the distribution of 5 additional glial cell markers: GFAP and cell surface antigens A010 (Mr 110,000 glycoprotein); AJ8 (Mr 100,000 glycoprotein); LK26 (Mr 35,000 glycoprotein); and Thy-1. Distinct patterns of expression on cultured astrocytomas and in neural tissues were identified for all antigenic systems studied, and cell surface expression of antigen A4 was found to correlate closely with GFAP phenotype of cultured astrocytomas. The antigens described in this study provide new markers to study normal glial differentiation and to correlate the phenotypes and biological behavior of distinct subsets of astrocytomas.

Animals↗
PubMed1986

An evaluation of current approaches to nursing home capital reimbursement.

One of the more controversial issues in reimbursement policy is how to set the capital cost component of facilities rates. In this article we examine in detail the various approaches used by states to reimburse nursing homes for capital costs. We conclude that newer approaches that recognize the increasing value of nursing home assets over time, commonly called fair rental systems, are preferable to the methodologies that have been used historically in both the Medicare and the Medicaid programs to set capital rates. When properly designed, fair rental systems should provide more rational incentives and less encouragement of property manipulation than do more traditional systems, with little or no increase in state costs.

Capital Financing↗
PubMed1986

Epstein Barr virus-specific immune defects in patients with persistent symptoms following infectious mononucleosis.

In a number of patients recovery from infectious mononucleosis (IM) following primary Epstein Barr virus (EBV) infection, is complicated by the persistence of symptoms for months or years. Normally recovery from infectious mononucleosis is associated with the development of EBV-specific antibodies and memory cytotoxic T-cells, which are present in the peripheral blood of all normal seropositive individuals. We studied four patients who had persistent symptoms for more than two years after infectious mononucleosis to determine if this abnormality was associated with a defect in EBV-specific or non-specific immune responses. All four patients had normal immunoglobulin concentrations, T- and B-cell numbers, T-cell proliferative responses and natural killer cell activity. However three of the four had reduced or absent antibodies to the EBV nuclear antigen (EBNA) although other EBV-specific antibody titres were normal. All four also had reduced EBV-specific cytotoxic T-cell activity as measured by the EBV regression assay. This defect was probably EBV-specific as alloreactive cytotoxic T-cell responses were normal. In addition, three of three patients tested had reduced in vitro antibody synthesis following pokeweed mitogen stimulation. These studies indicate that the syndrome of persistent symptoms following EBV mononucleosis may be associated with a defect in EBV-specific immunity, and thus suggest a possible immunological basis for the syndrome.

Adolescent↗
PubMed1986

Impingement syndrome. A review of late stage II and early stage III lesions.

From 1980 to 1984, 72 patients with impingement syndrome were treated by anterior acromioplasty before they developed rotator cuff tears. Follow-up evaluations averaged 23 months (range, five to 48 months). The average age was 42 years (range, 23-61 years). Preoperatively, 80% of the patients had pain at rest; the other 20% complained of pain during moderate activity. At the time of follow-up examination, 89% showed significant improvement, while 11% remained unchanged. Thirty-seven percent of the patients had varying degrees of muscle weakness preoperatively; of these, 71% were improved, 21% were unchanged, and 8% had a further decrease in the range of motion postoperatively. The results indicate that anterior acromioplasty is an excellent procedure for relief of pain due to impingement. Additionally, beneficial results were obtained in range of motion and muscle strength. In only a few select cases was lateral clavicle excision or tenodesis of the long head of the biceps necessary. Caution is advised in allowing return to strenuous activity unless the patient has recovered adequate strength in the cuff musculature.

Acromion↗
PubMed1986

Small eyes (Sey): a homozygous lethal mutation on chromosome 2 which affects the differentiation of both lens and nasal placodes in the mouse.

Small eyes (Sey) is a semidominant, homozygous lethal mutation in the mouse (Roberts, 1967). It is allelic with SeyH, a radiation-induced homozygous prenatal lethal which has been mapped on chromosome 2. The effect of the Sey mutation is apparently limited to the growth and differentiation of the presumptive lens and nasal placodes. Homozygous Sey/Sey embryos can be distinguished as early as 10.5 days post coitum (p.c.); the optic vesicles grow out, but the ectoderm does not give rise to a lens and nasal pits never form. Immunohistochemical studies show that the distribution of the extracellular matrix glycoprotein laminin is not significantly different in the cephalic region of Sey/Sey versus Sey/+ or +/+ embryos. Sey/Sey embryos develop to term but without eyes or nose, and die soon after birth. Further analysis of Sey/Sey embryos may throw light on the mechanisms underlying morphogenesis of craniofacial structures in mammals.

Animals↗
PubMed1986

Femorofemoral bypass to relieve acute leg ischemia during intra-aortic balloon pump cardiac support.

This study reports our experience with 10 patients who underwent the emergent construction of a femorofemoral bypass graft to salvage an acutely ischemic lower extremity following the insertion of a transfemoral intra-aortic balloon pump catheter. All patients had excellent resolution of the ischemia and salvage of the extremity. Half of the procedures were done at the bedside with the remainder performed in the operating room. No long-term infections or ischemic sequelae resulted from the procedures in the nine patients available for long-term follow-up. The use of femorofemoral bypass grafting is, therefore, recommended in patients with severe ipsilateral limb ischemia who are dependent on an intra-aortic balloon pump to prevent extremity tissue loss as well as the systemic metabolic manifestations of ongoing tissue ischemia and necrosis. Patient selection, technical considerations, and postoperative management are discussed.

Adult↗