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Biomedical subjects

N Cohen

Publications and source records attributed to N Cohen.

At least 271 records · Page 15Linked to original sources
PubMed1986

Coexistence of sporadic multiple endocrine neoplasia and scapular ectopic breast. Coincidence or biologically associated?

We describe a patient who presented with sporadic pheochromocytoma and parathyroid adenoma in the absence of medullary thyroid carcinoma, which coexisted with fully developed scapular ectopic breast tissue. If not coincidental, this association might support the concept that all components of multiple endocrine neoplasia type IIA originate from embryonic ectodermal tissue, and that sporadic multiple endocrine neoplasia type IIA, as well as ectopic breast tissue, may result from a noxious event at a critical embryonic stage.

Adenoma↗
PubMed1986

The effects of uremic serum and 3'-5' cyclic AMP on blastogenesis of normal lymphocytes.

Phytohemagglutinin (PHA) induced lymphocyte blast transformation is impaired both in uremic lymphocytes and in normal lymphocytes exposed to uremic serum. Cyclic AMP is known to inhibit blast transformation in normal and uremic lymphocytes. This investigation was undertaken to assess quantitatively the effects of uremic serum and cyclic AMP on blastogenesis of normal lymphocytes. Uremic serum or cyclic AMP significantly inhibited blast transformation of normal lymphocytes. These effects were statistically similar and cumulative. We conclude that the inhibition imposed by uremic serum on normal lymphocyte blastogenesis is predominantly mediated by a mechanism(s) different from cyclic AMP.

Cells, Cultured↗
PubMed1986

Pneumaturia: need for diagnostic alertness.

Pneumaturia, an air-filled urinary bladder with or without passage of gas in the urine, is a rare phenomenon in the general population, but is more frequent in defined high-risk subgroups. Relevant symptomatology may be hardly noticeable for a relatively long period; however, the outcome may be serious and sometimes fatal. We present three such cases and discuss diagnostic and therapeutic aspects.

Adult↗
PubMed1986

An unusual case of POEMS syndrome.

A 58-year-old woman presented with a history of premature onset of menopause, longstanding hepatosplenomegaly, monoclonal gammopathy, lower limb polyneuropathy of recent onset, diabetes mellitus, excessive perspiration and leg edema. Polyneuropathy and excessive perspiration improved following a course of prednisone and melphalan. The clinical and pathophysiological features fit the rare entity known as POEMS syndrome.

Drug Therapy, Combination↗
PubMed1985

Immune responses of thymus/lymphocyte embryonic chimeras: studies on tolerance and major histocompatibility complex restriction in Xenopus.

A new model has been developed to address the question of whether T cells that traverse an allogeneic thymus during early and late life become restricted to interact, in vivo, with other leukocytes and target cells that display the major histocompatibility complex (MHC) antigens of the thymus haplotype. Chimeras were made microsurgically with pairs of 24-h-old Xenopus embryos such that the anterior region of an embryonic chimera contained the thymus anlagen and was of one MHC genotype, whereas the posterior region contained the anlagen of all hemopoietic cells and was of another genotype. Assays to determine the MHC haplotype restriction specificity of T cells in chimeras that had been reared through metamorphosis involved: specific antibody responses (IgM and IgG) to dinitrophenylated keyhole limpet hemocyanin; rejection of minor H locus disparate skin grafts that expressed the MHC antigens of either the thymus donor or the lymphocyte donor; and mixed leukocyte culture. MHC-mismatched chimeras displayed split tolerance since they accepted skin grafts of the thymus haplotype but had lymphocytes that proliferated in response to MHC antigens of the thymus donor strain as well as to MHC antigens of third-party donors. IgM responses of MHC-matched and MHC-mismatched chimeras and of nonchimeric controls did not differ. However, the IgG responses of MHC-mismatched thymus/lymphocyte chimeras peaked later than those of MHC-matched chimeras and normal controls. Data from skin grafting protocols were consistent with the proposition that there may be in vivo selection of T cells reactive to minor H antigens presented in association with the MHC antigens of the thymus rather than the MHC antigens of the lymphocytes themselves. These data suggest that although it is not absolute, there is thymic selection of the T cell repertoire in Xenopus.

Animals↗
PubMed1985

High thresholds for movement perception in schizophrenia may indicate abnormal extraneous noise levels of central vestibular activity.

A theoretical argument proposes that thresholds for visual perception of movement should be abnormally high in schizophrenia. This may reflect a central vestibular dysfunction, consisting of abnormally high levels of extraneous noise within the neural activity of the central vestibulo-cerebellar complex. Two experiments are reported with results that support the hypothesis. To some extent, the disorder may explain the smooth pursuit eye movement dysfunction in schizophrenia. Relations to the dopamine hypothesis in schizophrenia are discussed.

Cerebellum↗
PubMed1985

Landholding, wealth and risk of blinding malnutrition in rural Bangladeshi households.

The 1982-1983 Bangladesh nutritional blindness study visited 11,618 rural households and examined 18,660 preschool-age children in an effort to determine the prevalence and determinants of eye lesions and loss of sight due to vitamin A deficiency (xerophthalmia). Risk of xerophthalmia was significantly higher for children from households without any of the indicators of relative wealth used. Almost 80% of blind children from landless households, and even a very small garden reduced considerably the chances of a household having a xerophthalmic child. Poorer households with access to less than 0.3 acres land or no garden or without a tin roof, wristwatch, radio or cycle were at least twice as likely as their more fortunate neighbours to have a young child with any type of xerophthalmia. Taking account of such socio-environmental risk factor weightings would direct the scarce resources of intervention programmes to households and children who most need them.

Bangladesh↗
PubMed1985

Symptomatic renal artery stenosis superimposed on chronic glomerulonephritis.

We present two patients with proved chronic glomerulonephritis who had severe refractory hypertension and chronic renal failure. In both patients normal-sized kidneys were demonstrated in addition to vascular bruits and Grade III hypertensive retinopathy. These findings raised the suspicion of an etiological condition other than chronic glomerulonephritis underlying the hypertension and renal failure. Renal angiography revealed bilateral severe renal artery stenosis. In both cases renal revascularization was followed by a drop in blood pressure to normal or near normal levels. In selected cases with severe hypertension and chronic renal failure, renal artery stenosis should be considered, despite the coexistence of chronic glomerulonephritis.

Antihypertensive Agents↗
PubMed1985

Congenital afibrinogenemia: an unusual case.

We describe a congenitally afibrinogenemic young man who experienced massive spontaneous bleeding episodes at unusual sites, including the thigh muscles, lung and brain. Each of these life-threatening episodes raised theoretical and critical practical problems. A large local hematoma was responsible for an accelerated consumption of fibrinogen, which was relieved following evacuation. It is unusual for an afibrinogenemic patient to survive a number of potentially lethal bleeding episodes.

Adult↗
PubMed1985

Should acute gold overdose be invariably treated?

Acute gold overload is rare and its clinical and pathophysiological consequences are not well delineated. Consequently the therapeutic approach has not been formulated. We describe 2 patients with rheumatoid arthritis in whom an acute gold overload was inadvertently administered. Their subsequent course, without specific treatment, was benign and uneventful. We suggest that with similar cases a conservative approach of watchful expectancy be adopted.

Acute Disease↗
PubMed1984

Cimetidine, cigarette smoking, and recurrence of duodenal ulcer.

Three hundred seventy patients with recently healed duodenal ulcer entered into a one-year, double-blind, randomized multicenter trial comparing placebo with three different dose schedules of cimetidine (200 mg twice a day, 300 mg twice a day, and 400 mg at bedtime) for the prevention of recurrent duodenal ulcer. By the end of one year, the cumulative symptomatic recurrence rate as demonstrated by endoscopy was similar for the patients receiving the three dosages of cimetidine (19 per cent, 15 per cent, and 13 per cent, respectively; not significant), whereas the placebo-treated group had a 34.7 per cent symptomatic recurrence rate (P less than 0.01 as compared with each cimetidine group). Cigarette smoking was found to be an important variable; among the placebo recipients ulcer recurrence was significantly more likely in smokers (72 per cent) than in nonsmokers (21 per cent, P less than 0.001). The frequency of ulcer recurrence in smokers was significantly reduced by treatment with cimetidine (from 72 per cent to 34 per cent, P less than 0.). Smokers who received cimetidine were at least as likely to have a recurrence as were nonsmokers who received placebo (34 per cent vs. 21 per cent, not significant). Thus, smoking appears to be a major factor in recurrence of duodenal ulcer, and in smokers, giving up smoking may be more important in the prevention of ulcer recurrences than administration of cimetidine.

Cimetidine↗