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Biomedical subjects

N Klein

Publications and source records attributed to N Klein.

126 records · Page 7Linked to original sources
PubMed1983

Acquired immunodeficiency with reversed T4/T8 ratios in infants born to promiscuous and drug-addicted mothers.

A new syndrome of acquired immunodeficiency has been identified in seven children who were small for gestational age at birth and subsequently have exhibited failure to thrive, lymphadenopathy, parotitis, hepatosplenomegaly, interstitial pneumonia, and recurrent infections. All have a profound cell-mediated immunodeficiency with reversed T4/T8 ratios. Six are hypergammaglobulinemic and one has low IgG levels. The mothers of five of the seven children are sexually promiscuous and/or drug addicts. Three mothers have an immunodeficiency similar to that found in their infants. One of them died at age 33 years with a diagnosis of acquired immunodeficiency syndrome. In five of the children and in three of their mothers, there is evidence of a persistent Epstein-Barr virus (EBV) infection. We speculate that a perinatal or in utero transmission of EBV can induce an "infectious immunodeficiency." The clinical, histopathologic, and immunologic features resemble those described in adult homosexuals and drug addicts.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Comparative effects of abrupt withdrawal of propranolol and verapamil in angina pectoris.

The potential hazards of abrupt withdrawal of propranolol have been described in patients with angina pectoris; however, the effects of abrupt withdrawal from long-term therapy with verapamil have not previously been investigated. The comparative effects of withdrawal from long-term treatment with propranolol and verapamil were assessed in a placebo-controlled double-blind randomized crossover study of 20 patients received placebo for 2 weeks, then increasing doses of propranolol (60 to 320 mg/day) or verapamil (240 to 480 mg/day) for 3 weeks. Patients were then abruptly withdrawn from drug onto placebo for 1 week, followed by crossover to the other drug treatment and a second withdrawal period. All 20 patients were withdrawn from verapamil without evidence of a rebound increase in frequency of anginal attacks, blood pressure, heart rate, or rate-pressure product and without a rebound deterioration in exercise tolerance. In contrast, with propranolol withdrawal, 2 patients (with the highest baseline angina attack rate) had a severe exacerbation of their anginal syndrome and could not undergo formal exercise testing; the other 18 patients were withdrawn from propranolol without incident. Plasma catecholamines were increased during exercise compared with rest during all treatments; however, the levels of catecholamines during exercise were significantly higher with propranolol than with verapamil and placebo (p less than 0.05). Levels of exercise catecholamines returned to placebo baseline values after withdrawal of propranolol.

Angina Pectoris↗
PubMed1981

Efficacy of sublingual nifedipine in the acute treatment of systemic hypertension.

The effects of sublingual nifedipine, a calcium antagonist vasodilator, were assessed in 43 patients with moderate to severe hypertension in an emergency room setting. Following a no-response placebo treatment period, the patients with supine diastolic blood pressure of less than 110 mm Hg (group A, n equals 17) received 10 mg of sublingual nifedipine, and the patients with supine diastolic blood pressure of much greater than or equal to 110 mm Hg (group B, n equals 26) received a 20-mg sublingual dose. In group A, systolic blood pressure decreased from 172.4 plus or minus 18.6 mm Hg to 140.0 plus or minus 14.6 mm Hg; diastolic pressure from 108.8 plus or minus 3.3 mm Hg to 87.6 plus or minus 9.9 mm Hg (P less than 0.001)., In group B, systolic blood pressure decreased from 203.8 plus or minus 22.1 mm Hg to 160.0 plus or minus 23.6 mm Hg; diastolic pressure from 127.7 plus or minus 11.3 mm Hg to 96.7 plus or minus 14.1 mm Hg (P less than 0.001). Heart rate increased significantly only in the 20-mg dose group, from 76 plus or minus 2 to 89 plus or minus 6 beats/min (P less than 0.005). Th effects of sublingual nifedipine were seen in one to five minutes, and the maximal effect in 20 to 30 minutes, with return to placebo baseline in four to five hours. Adverse reactions were minimal in both treatment groups. Nifedipine is an effective and safe hypotensive drug in the rapid management of moderate to severe hypertension and seems to be an effective nonparenteral agent for treatment of hypertensive emergencies.

Acute Disease↗
PubMed1981

Tarsal coalitions: an instructional review.

Tarsal coalitions, the majority of which are congenital, are abnormal unions between two or more tarsal bones. Acquired tarsal coalitions may result from trauma or from rheumatic conditions. Tarsal coalition may cause peroneal spastic flatfoot or rigid valgus foot without peroneal spasm. Surgery is not always essential in the treatment of tarsal coalitions; some patients will respond to conservative treatment.

Adult↗
PubMed1975

Human granulocyte lysosomal elastase activity using t-butyloxycarbonyl-L-alanine p-nitrophenyl ester and elastin-rhodamine as substrates.

Polymorphonuclear leukocyte lysosomal esterolytic activity on the synthetic substrate, t-butyloxycarbonyl-L-alanine p-nitrophenyl ester was observed to correlate well with polymorphonuclear leukocyte granule elastase activity measured on the natural substrate, elastin, bound to rhodamine. In addition, the effect of highly specific, irreversible chloromethyl ketone elastase inhibitors on leukocyte lysosomal elastase activity was similar, using t-butyloxycarbonyl-L-alanine p-nitrophenyl ester or elastin-rhodamine as substrate. Whether polymorphonuclear leukocyte lysosomal granules contain two different enzymes, a true elastase with esterase activity and a similar esterase without elastase activity, as found in the human pancreas, is, as yet, unknown. Both enzyme activities have been identified in isoenzymes of purified human polymorphonuclear leukocyte lysosomal elastase. The correlations observed between the two enzymes, if present in polymorphonuclear leukocytes, are sufficiently strong to use the esterase assay for clinical purposes.

Alanine↗
PubMed1974

Then there is Suzie.

Explore the source record for details and available documents.

Abnormalities, Multiple↗
PubMedDate not supplied

Ageing and social rank effects on the reproductive system of free-ranging yellow baboons (Papio cynocephalus) at Mikumi National Park, Tanzania.

Ageing and social status effects on reproductive condition are examined in 106 wild female baboons from 1974 to 1997. The mean duration of each reproductive state (follicular and luteal phase components, pregnancy and lactation) was examined per female, using a repeated measures analysis of variance across each of four age classes (3-6, 7-10, 11-14, and 15-20+ year olds) and dominance rank quartiles. The sex-skin swelling portion of the follicular phase increased whereas the fully swollen portion decreased in duration with advancing age and with low dominance rank. The detumescing portion of the luteal phase increased with advancing age, being most pronounced in lowest ranking females. The number of cycles to conception decreased with age, with no dominance rank effect. However, owing to variation in lactation duration, the interbirth interval was unaffected by age but was shorter in high ranking females. The miscarriage rate was unaffected by age but increased as female rank declined. Age and rank effects became significantly more pronounced in response to a crash in the study population between 1987 and 1993. In conclusion, age- and rank-related reproductive changes in baboons, like those in humans, appear to represent attempts to compensate endocrinologically for accelerated ovarian atresia and increased environmental hardship.

Aging↗
PubMedDate not supplied

Middle-school-age outcomes in children with very low birthweight.

Most previous studies of children with birthweight <750 g have focused on early childhood sequelae. To evaluate later outcomes, a regional sample of 60 <750-g birthweight children was compared at middle school age (M = 11 years) to 55 children with birthweight 750-1,499 g and 49 term controls. The groups were matched on age, gender, and demographic variables at the time of an early-school-age assessment (mean age 7 years). The <750-g birthweight group fared less well at middle school age than the term group on measures of cognitive function, achievement, behavior, and academic performance. In many instances, outcomes were less favorable for the <750-g children than for the 750 to 1,499-g group. Children in the <750-g group who were free of neurosensory disorders and global cognitive impairment performed more poorly on several tests than their term counterparts. Group differences in this subsample on tests of motor skills, math, and the ability to copy and recall a complex drawing remained significant even after controlling for IQ. Disparities between the <750-g and term groups increased with age for some measures. Despite favorable outcomes for many children in the <750-g group, this population is at risk for long-term developmental problems.

Attention↗
PubMedDate not supplied

Glaucoma detection using the GDx nerve fiber analyzer and the retinal thickness analyzer (RTA).

PURPOSE: To compare the ability of the nerve fiber analyzer (GDx) and the retinal thickness analyzer (RTA) to discriminate between glaucomatous and healthy eyes. METHODS: Thirty-seven glaucoma patients (early to moderate severity) and 34 healthy controls were included. Glaucoma patients were defined as those with two repeatable abnormal visual fields by automated perimetry within 1 year. All subjects were examined with a GDx scanning laser polarimeter and RTA. Twelve GDx retinal nerve fiber layer parameters and 12 RTA optic disk topography parameters were obtained. GDx and RTA measurements were compared between both experimental groups using t-tests. Areas under the receiver operating characteristic curves (AUROC) for discriminating between healthy and glaucomatous eyes using GDx and RTA parameters were calculated and compared, and sensitivities at >or=80% and >or=95% specificity were reported. RESULTS: Statistically significant differences between glaucomatous and healthy eyes were found for most GDx and RTA parameters. For GDx, the parameter with the largest AUROC for discriminating between healthy and glaucomatous eyes was the number (AUROC = 0.91, sensitivity = 85% at specificity = 84%, sensitivity = 73% at specificity = 95%). For RTA, the parameter with the largest AUROC was mean cup depth (AUROC = 0.79, sensitivity = 61% at specificity = 82%, sensitivity = 33% at specificity = 95%). The AUROC for the GDx number was significantly larger than the AUROC for RTA mean cup depth (p<0.05). CONCLUSIONS: GDx showed better discrimination and better sensitivities at fixed specificities than RTA. The currently available RTA optic disk analysis software likely cannot replace GDx RNFL analysis software for successful glaucoma diagnosis.

Area Under Curve↗
PubMedDate not supplied

Insider-out: the health worker as researcher.

This article discusses two dimensions related to the insider-outsider dilemma in conducting anthropological research in the health setting. One dimension concerns advantages of the insider's special knowledge in selecting and conducting successful research in a health institution. The other dimension deals with the ambiguity and confusion of roles attributed by staff to the investigator who may be seen as practitioner as well as social scientist. The patient may also see the researcher as performing dual, and possibly conflicting, roles. The advantage gained in the first dimension may be negated, to some extent, by the disadvantages associated with the second.

Health Workforce↗