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Biomedical subjects

B Nielsen

Publications and source records attributed to B Nielsen.

At least 307 records · Page 17Linked to original sources
PubMed1982

Mechanisms of G6PD isozyme pattern changes at fertilization.

The electrophoretic pattern of G6PD changes in sea urchin egg supernatants, gels, and pellets (homogenized in 0.01 M MgCl2, 0.01 M Tris, pH8, and centrifuged at 4 X 10(4)g) within the first minute following sperm penetration. Therefore, the changes in pattern are an early event of egg activation and are not changes in gene activity. Calcium ionophore activation causes similar changes in G6PD in unfertilized eggs, so calcium is probably involved directly or indirectly. Treatment with 1 mg/ml of G6P and/or NADP, DTT, or papain also causes changes in the isozyme patterns, but the resulting patterns are different from patterns obtained from the fertilized fractions, and each treatment produces a unique pattern. The results lead to the conclusion that the different patterns of unfertilized and fertilized eggs are due to enzyme posttranslational modification. Different patterns may result from intrinsic differences in 1) -SH reduction or levels of glutathione, 2) substrate and cofactor levels, or 3) proteolytic enzymes released naturally or as a result of homogenization.

Animals↗
PubMed1982

Vitamin D metabolites in diabetic patients: decreased serum concentration of 24,25-dihydroxyvitamin D.

In order to elucidate if changes in vitamin D metabolism play a role for diabetic bone loss, the serum concentrations of the major vitamin D metabolites were studied in 26 adult male ambulatory insulin-treated diabetics, selected to have normal renal function and a duration of diabetes below 11 years. The patients were studied during usual metabolic control and exhibited wide ranges of hyperglycaemia and glycosuria. The serum concentrations of the major metabolites of vitamin D, 25-hydroxyvitamin D(2 + 3) (25OHD), 24,25-dihydroxyvitamin D(2 + 3) (24,25(OH)2D), and 1,25-dihydroxyvitamin D(2 + 3) (1,25(OH)2D), were measured in diabetics, and in age and sex matched controls. The diabetics had slightly decreased serum levels of 25OHD (42.0 nmol/l versus 55.5 nmol/l in normals, P less than 0.05), markedly decreased serum levels of 24,25(OH)2D (2.98 nmol/l versus 5.91 nmol/l, P less than 0.01), but serum levels of 1,25(OH)2D were virtually normal (64.2 pmol/l versus 68.3 pmol/l, ns). The close correlation between serum concentrations of 25OHD and 24,25(OH)2D observed in the normal subjects, was absent in the diabetics. There were no correlations between the serum levels of any of the vitamin D metabolites and the measured indices of glucose and calcium metabolism. It is concluded that insulin-dependent diabetic patients demonstrate definite alterations in serum levels of vitamin D metabolites, the significance of which remains unknown at present.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

Agencies fill a need but are not the answer.

Although supplemental staffing agencies answer certain needs of both the hospital and the nurse, continued reliance on agency personnel can be detrimental to patient care and staff morale.

Morale↗
PubMed1980

A urodynamic study of cauda equina syndrome due to lumbar disc herniation.

Among 1,972 patients operated upon because of lumbar disc herniation in a 7-year period (1971-1978), cauda equina syndrome was diagnosed in 26 patients. 22 patients had follow-ups 4-72 months postoperatively (average 37 months). At follow-up half of the patients had histories of normal micturition and only 6 patients made serious micturition complaints. One third were free from lumbar or sciatic pain, two thirds complained of distressing pain and neurological symptoms. The urodynamic investigation revealed complete bladder emptying in all but 1 patient. In half of the patients normal detrusor contraction was demonstrated, while one third of the patients voided by straining only. Preoperative micturition symptoms exceeded 2 days in almost all patients voiding by straining. This finding indicates a connection between early diagnosis and treatment, and the degree of detrusor damage.

Acute Disease↗
PubMed1980

Mutual pro-drugs of beta-lactam antibiotics and beta-lactamase inhibitors.

The principle of combining a beta-lactam antibiotic with a beta-lactamase inhibitor in a single molecule functioning as pro-drug for the two active components is illustrated by the linked esters 3 and 4 in which ampicillin and mecillinam, respectively, are combined with the beta-lactamase inhibitor penicillanic acid sulfone. It is shown that in man these esters are excellently absorbed from the gastro-intestinal tract and after absorption hydrolyzed with simultaneous liberation of the active components. As a result high blood and tissue levels of antibiotic and beta-lactamase inhibitor in a balanced ratio are attained. The advantages of "mutual pro-drugs" over simple combinations are discussed.

Anti-Bacterial Agents↗
PubMed1979

Effect of alprenolol on mortality among patients with definite or suspected acute myocardial infarction. Preliminary results.

A double-blind study of alprenolol versus placebo was done in patients with definite or suspected myocardial infarction to show the effect of the drug on mortality-rate after a year of treatment in patients aged less than or equal to 65 and to study the tolerance of the drug by patients greater than 65 years of age. The dose given was 5--10 mg intravenously, followed by 200 mg twice a day, orally. Patients in whom beta-blockade was contraindicated were excluded. All deaths, side-effects, and dropouts were recorded. Of the 480 patients in the study, 238 patients received alprenolol and 242 placebo. During the year of follow-up 108 patients dropped out from the study. Mortality was not reduced in patients greater than 65 years of age. In those less than or equal to 65 years alprenolol significantly reduced mortality-rate (20% mortality in placebo group vs 9% in treated group). There was also a significant reduction in mortality-rate among those with definite infarction (28% in the placebo vs 15% in the treated group).

Acute Disease↗