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Biomedical subjects

C Cohen

Publications and source records attributed to C Cohen.

At least 379 records · Page 21Linked to original sources
PubMed1981

Vitamin D nutrition in relation to season and occupation.

Seasonal variations in vitamin D nutrition were assessed by measurements of serum 25-hydroxycholecalciferol levels in outdoor workers, indoor workers and long-term hospital inpatients. All three groups showed seasonal changes and the outdoor workers had, as might be expected, the highest levels at all seasons. However, the highest levels of 25-hydroxycholecalciferol were found in October in the indoor workers and in November for the outdoor workers whereas the peak in ultraviolet exposure was in July. The possible reasons for this long lag are discussed; the most likely explanation is that vitamin D continues to be formed and stored during the autumn especially in outdoor workers.

Adult↗
PubMed1981

Pediatric total parenteral nutrition. Liver histopathology.

Correlation of clinical data with hepatic histopathology from 31 infants receiving total parenteral nutrition (TPN) suggest chronologic progression of liver disease with long-term TPN. Steatosis and a prominent eosinophil component in portal-tract extramedullary hematopoiesis appear during the first five days of TPN. The former persists for 90 days, the latter for three weeks. Canalicular cholestasis was present after ten days in 84.2% of the livers studied and bile duct proliferation in 63.6% after three weeks of TPN. Moderate to severe portal fibrosis only occurred after 90 days, whereas micronodular cirrhosis developed in one patient after five months of TPN. Lipofuscin-like pigment and hemosiderin were each demonstrated in 90.3% of the livers studied. Our findings suggest that with up to 90 days of TPN most changes should either be reversible or not severe enough to result in liver failure.

Amino Acids↗
PubMed1981

Psychosomatic disorders in a rural family practice in israel.

A survey carried out in the Shimshon family health centre in the rural area of Jerusalem revealed that 24 per cent of new patient-doctor contacts were for psychosomatic disorders.The three major. disorders-back pain, headache and abdominal pain-were present in almost 79 per cent of all psychosomatic contacts. Other common disorders were chest pains, palpitations, malaise and nocturnal enuresis. Classic illnesses such as peptic ulcer or asthma were less common. The incidence of peptic ulcer, asthma, atopic dermatitis and chest pains was higher among males than females; rates for headache, palpitations and malaise were higher for females than males. Back pain, headache and abdominal pains occurred differently among the five ethnic groups of the study population. Therapeutic care is carried out through assessment and study of the patient and his or her family.

Adolescent↗
PubMed1980

Epidemiologic and histologic patterns of Hodgkin's disease: comparison of the black and white populations of Johannesburg, South Africa.

Histologic patterns of Hodgkin's disease in black and white patients in Johannesburg, South Africa, were studied in relation to sex and age, and compared with each other and with published studies on American, Nigerian, and Ugandan black and American white patients. Pretreatment lymph node biospy specimens from 88 black and 54 white patients were reviewed and histologically subtyped according to the Rye classification. In Johannesburg, black patients have a high frequency of mixed cellular (MC) and lymphocyte depleted (LD) subtypes, and of childhood disease. Male patients predominate in all subtypes including nodular sclerosis (NS) which equals LD in frequency. White Johannesburg patients have a low frequency of childhood disease, an increased rate in young adults, and a relatively high frequency of NS with female patients predominating, although MC is the predominant subtype. Both population groups tend to fall into the intermediate epidemiologic Pattern II, with a bias to Pattern I in black patients, reflecting their poorer socioeconomic condition, and a bias to Pattern III in white patients, reflecting their improved socioeconomic situation.

Adolescent↗
PubMed1980

Motions of tropomyosin. Crystal as metaphor.

Movements of tropomyosin play an essential role in muscle regulation. This fibrous protein is a two-chain alpha-helical coiled coil that bonds head to tail to form cables wound in the two long grooves of the actin helix. The regulatory switch consists of tropomyosin and a "globular" Ca2+-sensitive protein complex called troponin. The structure of the tropomyosin filaments has now been determined by x-ray crystallography to approximately 15 A resolution. The complete sequence of alpha-tropomyosin is known; by using mercury markers on the cysteine residues the ends of the molecules in the filaments have been identified. Details of the coiled-coil structure have also been visualized by refinement of models against the diffraction data. The average pitch of the coiled coil is approximately 137 A, so that each tropomyosin molecule can make similar contacts with seven actin monomers. The electron density map also indicates that departures from the alpha-helical coiled coil occur in a few localized regions of the molecule, especially at the overlapping ends. Motions of tropomyosin in the crystal lattice are displaced by the character of the Bragg reflections and the strong diffuse scatter. These effects depend markedly on temperature. It appears that the molecular filaments fluctuate freely in a direction perpendicular to their axes. Moreover, the C-terminal half of the molecule "unfolds" to some degree at less than physiological temperatures. Crystallographic results on co-crystals of tropomyosin and a component of troponin (TnT) suggest that this subunit consists of structurally distinct domains, so that the troponin complex is not in fact simply "globular". The interactions of the extended alpha-helical region of TnT may "stiffen" tropomyosin and influence its motions. We picture the tropomyosin/troponin switch in muscle as a restless cable, perpetually making and breaking bonds as it vibrates on the thin filament. These movements of tropomyosin probably depend on two aspects of its design: the regular pattern of coiled-coil linkages with actin; and the aperiodic features that allow flexibility and motion.

Animals↗
PubMed1980

Dual task performance during bimanual coordination.

Right-handed men and women tapped two mechanical keys in time to an entraining metronome, using each hand alone and the two hands in alternation. Concurrently, they recited familiar nursery rhymes or read unfamiliar text out loud. The direction of interference from the language-based tasks on manual performance was measured relative to baseline performance. Magnitude and direction of interference from both language tasks were greater during bimanual alternation than unimanual performance. However, the direction of interference during bimanual alternation differed significantly between right-handed men and women, and the sex differences in direction of interference differed according to the characteristics of the language-based secondary task. Right-handed subjects with a family history of sinistrality showed less overall and less lateralized dual task interference than right-handed persons without a family history of sinistrality.

Adult↗
PubMed1980

Chemotherapy of recurrent ovarian carcinoma with cis-dichlorodiammine platinum II and adriamycin.

Forty-six patients with recurrent disseminated ovarian carcinoma were treated with a combination of cis-dichlorodiammine platinum II (DDP) 50 mg/m2 and adriamycin 50 mg/m2 given intravenously every 3 weeks. All patients had failed prior chemotherapy. The combination of adriamycin and DDP produced objective responses in 14 of 46 patients. Severe side effects were frequent, but no patient died as a result of treatment. Disease in 4 of 7 complete responders is currently in remission up to 4 years.

Adult↗
PubMed1980

Studies of orthotopic allografts of oral mucosa and skin across a histocompatibility barrier in a model system.

The mucosal allograft offers a reproducibile model for the characterization of the response of the oral mucosa to immunopathologic processes. Orthotopic allografts of oral mucosa or of skin were exchanged between pairs of unrelated rabbits known to be either matched or mismatched at the major histocompatibility locus (RLA). Rabbits with autografts of these tissues served as controls. The behavior of allografts of oral mucosa and of skin, although similar in many ways, showed marked differences in the morphology of the rejection reaction including more striking vascular damage and vascular occlusion in skin and in the longer persistence of granulocytes throughout the period of rejection in mucosal allografts. The rejection of matched allografts appeared morphologically similar to that of mismatched grafts but the time sequence was delayed. Morphological differences between the rejection reactions in allografts or oral mucosa and those of skin may result from differences in the expression of histocompatibility and tissue specific antigens in these tissues as well as other local factors such as the nature and distribution of mucosubstances of the connective tissue ground substance, the regional blood flow, and the absorption of salivary components including water in an oral wound.

Animals↗
PubMed1980

Multiple cutaneous carcinomas and lymphomas of the skin.

There is an increased risk of malignancy (particularly skin carcinomas and malignant lymphomas) in patients who have genetically determined and acquired immunosuppression. Multiple cutaneous squamous and basal cell carcinomas of the face and scalp with adjacent lymphomatous infiltration of the skin developed in a patient with stage IVA diffuse poorly differentiated lymphocytic lymphoma. He had had one cycle of vincristine sulfate, prednisone, and cyclophosphamide therapy for his lymphoma more than one year before. He showed impaired delayed hypersensitivity response on skin testing with common antigens and he had a low serum (IgG) level.

Aged↗