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Biomedical subjects

E Keck

Publications and source records attributed to E Keck.

66 records · Page 4Linked to original sources
PubMed1979

[Chronic occlusion of a renal artery with aneurysms in the para-aortic collateral circulation and multiple aneurysms in both kidneys (author's transl)].

Chronic occlusion of the main renal artery may be followed by the development of a collateral circulation through ureteric and para-aortic arteries, and through lumbar and suprarenal arteries. A patient with occlusion of the left main renal artery is described, who developed a collateral circulation between the common iliac artery and the distal portion of the renal artery. The para-aortic collateral vessel developed one large and several small aneurysms, and there were aneurysms in both kidneys.

Aneurysm↗
PubMed1978

[Symmetric cerebral calcification associated with disturbed parathyroid function (author's transl)].

Alteration of the metabolism of calcium and phosphate may be associated with symmetric cerebral calcification. Detailed investigations of the function of parathyroid glands including computer tomography of the brain are so far missing. In 6 patients with clinical and biochemical signs of altered function of the parathyroid glands symmetric cerebral calcification could be demonstrated by computer tomography. They are also visible by X-ray examination in one patient. Consequently, functional disturbances of the brain, cerebellum and of the extrapyramidal system may occur. Moreover, the combination of hypoparathyroidism and hypothyroidism also appears to result in the development of symmetric cerebral calcification. The pathogenesis of the calcification as well as therapeutic approaches will be discussed.

Adult↗
PubMed1976

Estrone and estradiol in patients with cirrhosis of the liver: effects of ACTH and dexamethasone.

To study the influence of the adrenal gland on plasma estrogen levels in male patients with hepatic cirrhosis, estrone and estradiol were measured under a variety of experimental conditions. Compared to controls, estradiol levels were moderately elevated by 26% (P is less than 0.05) in patients with hepatic cirrhosis (28.5 +/- 5.4 vs. 36.0 +/- 4.7 pg/ml plasma; n: 12), whereas estrone levels exhibited a two- to threefold increase under basal conditions (32.5 +/- 5.6 vs. 67.8 +/- 20.8 pg/ml; P is less than 0.01). ACTH application resulted in a striking increase in plasma estrone levels in both patients with hepatic cirrhosis and in normal subjects (61.8 +/- 27.5 vs. 27.3 +/- 7.8 pg/ml). During stimulation with ACTH, estradiol levels showed no significant changes. After suppression of the adrenal gland by dexamethasone administered for 5 days, plasma concentrations of estrone and estradiol were found to be reduced. The absolute decrease of estrone was significantly greater in patients with hepatic cirrhosis than in healthy male subjects (35.5 +/- 12.6 vs. 21.3 +/- 6.0 pg/ml; P is less than 0.05; n: 8). Estrogen values, however, were still high in patients with hepatic cirrhosis after 5 days of dexamethasone administration (37.1 +/- 17.6 pg estrone/ml and 23.9 +/- 3.6 pg estradiol/ml plasma). It is suggested that elevated plasma values of estrogens in this disorder may be derived predominantly from adrenal production. Peripheral conversion of androgens to estrone rather than to estradiol appears to be more effective in sustaining plasma levels of estrogens in patients with hepatic cirrhosis.

Adrenal Glands↗
PubMed1975

[The role of the hypophysis and the hypophyseal hormone prolactin in maintenance of the sexual specificity of the metabolism of testosterone and 5-alpha-dihydrotestosterone in rat liver slices].

Hypophysectomy of rats 55 days after birth causes profound changes in the sexually differentiated liver metabolism of testosterone and 5alpha-dihydrotestosterone, which were studied when the rats were 80 days old. 1. Metabolism of testosterone after hypophysectomy: The turnover of testosterone decreased significantly to the same level in both sexes. The effect was especially marked in the female, which normally has a high turnover of this compound. The sexual differences in the patterns of metabolites were also lost, owing to the following changes: In the male, the high level of metabolites of the 3beta-hydroxy-5alpha-androstane type falls to the low level found in the female controls. The low level of 4-androstene-3,17-dione in the female increases to the high level found in the male controls. The concentrations of testosterone increase and those of the metabolites of the 3-oxo- and 3alpha-hydroxy-5alpha-androstane decrease to values that are significantly much higher or lower, respectively, than the normal values found in the control animals. 2. Metabolism of 5alpha-dihydrotestosterone after hypophysectomy: In comparison with the controls, the turnover of this substrate is significantly decreased by the same factor in both sexes; thus the difference between the sexes persists. In the pattern of metabolites, the sexual differences are still apparent, but less marked. The levels of metabolites show two opposing changes: a significant increase in the concentration of 3beta-hydroxy metabolites, and a significant decrease in the concentration of 3alpha-hydroxy metabolites; although the activity of the microsomal 3alpha-hydroxysteroid dehydrogenase increases by a factor of 3 - 4 in both sexes after hypophysectomy[1]. This discrepancy indicates a compartmentalization of androgen metabolism in the liver cell, in which delta4-5alpha- and 3beta-hydrogenation occur on the membranes of the endoplasmic reticulum, whereas 3alpha-hydrogenation occurs in the cytosol. 3. Action of prolactin on the metabolism of testosterone in hypophysectomized animals: Prolactin (125 mug twice daily from the 70th to the 79th day of life) causes a significant acceleration of the delta4-5alpha-hydrogenation, which is recognized as a significant increase in the concentrations of 5alpha-androstane metabolites; the 3beta-hydroxy compounds in both sexes reach the normal level of male control animals. The significant increase in the concentration of 3alpha-hydroxy compounds is accompanied by a partial reestablishment of the sexual differences. The sex differences in androgen turnover and metabolite pattern are subject to a hypophyseal regulation, which is separate from the gonadotropic partial function. The hydroxylation activity of the liver, measured as the production of C19O3-steroids, is not significantly affected by hypophysectomy or by treatment with prolactin.

Androstanes↗
PubMedDate not supplied

Measurement of ascorbic acid and erythorbic acid in processed meat by HPLC.

A simple and efficient HPLC method is described to measure both ascorbic and erythorbic acid separately in processed meat products. The system used consisted of a reversed-phase column, a mobile phase containing an ion-pairing agent and ultraviolet detection. The procedure, which was checked on a variety of samples, was found to give reproducible and reliable results.

Animals↗
PubMedDate not supplied

[Immunocytochemical and biochemical studies of an Ewing sarcoma cell line: evidence for neural differentiation in vitro].

A cell line established from a Ewing's sarcoma removed from the fibula of a 19-year-old female was investigated for morphology and hormone sensitivity. Cells in culture expressed neurofilaments and showed positive immunostaining for neuron-specific enolase (NSE), Leu-7-antigen (HNK-1) and S-100 protein. The cells also contained PAS-positive, diastase-digestible cytoplasmic material, indicative of glycogen inclusions. Moreover, the cells responded to dopamine as well as to beta-adrenergic agonists and prostaglandins to stimulate cyclic AMP synthesis and 3H-glycogen hydrolysis. In conclusion, the morphological and biochemical data show evidence for a neural differentiation pattern of Ewing's sarcoma cells in vitro.

Antigens, Differentiation↗
PubMedDate not supplied

[Fracture incidence in 803 women with postmenopausal osteoporosis under drug treatment].

In a survey of cases of confirmed postmenopausal osteoporosis, 803 women were asked to complete a questionnaire on radiologically confirmed fractures sustained prior to and during drug therapy. Under monotherapy (fluoride or calcium, n = 92) the number of peripheral and central fractures was 54% and 49% lower, respectively. The corresponding figures with two substances (fluoride and calcium, n = 226) were 58% and 60%, with three substances (fluoride, calcium and estrogens or Vitamin D, n = 223) 83% and 72%, and with four substances (n = 254) 85% and 75%.

Aged↗
PubMedDate not supplied

[Regulation of in vitro metabolism of human spongiosa by parathyroid hormone and calcitonin].

A method was developed to investigate in vitro metabolism of human trabecular bone and its hormonal regulation. Human and bovine parathyroid hormone 1-34 caused an increase in the release of calcium and magnesium out of human bone. Human, salmon and porcine calcitonin caused a decrease in the release of calcium and magnesium and inhibited the effect of parathyroid hormone.

Aged↗
PubMedDate not supplied

[Osteocalcin and bone metabolism in rheumatoid arthritis and osteoarthritis].

Osteocalcin is the most abundant noncollagenous protein of bone and is regarded as the best biochemical marker for bone formation. The synthesis of this protein in osteoblasts is stimulated by 1.25-Dihydroxyvitamin D3 (1.25(OH)2D3). The aim of this study was to examine the rate of bone formation measured by osteocalcin in patients (pts) with rheumatoid arthritis (RA) (n = 58) and osteoarthrosis (OA) (n = 14) and its dependence on various parameters of calcium and phosphate metabolism, especially vitamin D metabolites. Furthermore we compared the significance of alkaline phosphatase and osteocalcin as a parameter for bone turnover in these patients. According to treatment pts with RA were divided into four groups: one receiving gold salts (n = 14), one glucocorticoids (n = 13), one chloroquine (n = 14), and one nonsteroidal antiinflammatory drugs (NSAID) (n = 17). Pts with OA and RA treated with NSAID showed significantly lower values of osteocalcin than pts with RA treated with glucocorticoids or gold. In contrast to osteocalcin, alkaline phosphatase was significantly higher in all pts with RA than in pts with OA. 1.25(OH)2D, which was significantly (p less than 0.05) elevated in pts with RA treated with glucocorticoids, correlated significantly with parathyroid hormone (PTH). These data indicate that bone metabolism, at least in pts with OA and RA treated with NSAID is characterized by a decreased bone formation which is probably compensated in part in pts treated with glucocorticoids, as 1.25(OH)2D and PTH are significantly (p less than 0.05) elevated. Furthermore, the osteocalcin values were closely correlated with 1.25(OH)2D in pts with OA.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

[Effect of gold (III) on prostaglandin E2-stimulated adenyl cyclase in chick fibroblasts and osteoblasts].

Gold (III) (Au(III) up to 0.25 microM increased prostaglandin E2-sensitive chick osteoblast and fibroblast adenylate cyclase activity without affecting 5'-guanylylimidodiphosphate-stimulated enzyme activity. Au (III) at 5-50 microM inhibited hormone- and nucleotide-mediated activation of adenylate cyclase. This process is time-dependent, irreversible and can not be explained by desensitivation of the PGE2-receptor. Basal adenylate cyclase activity was not influenced by Au (III) in the given concentrations. Pretreatment of membranes with 5'-guanylylimidodiphosphate prior to incubation with Au (III) prevented the inhibitory effect of Au (III) on adenylate cyclase, similar to the incubation experiments with NEM instead of Au (III). Our data suggest that Au (III) at low concentrations unspecifically stimulates PGE2-sensitive adenylate cyclase by binding to sulfhydryl groups of the receptor protein and that Au (III) at high concentrations specifically inhibits PGE2-sensitive adenylate cyclase by binding to sulfhydryl groups of the N-Protein and/or of the catalytic unit.

Adenylyl Cyclases↗
PubMedDate not supplied

[Effect of prostaglandins on in vitro electrolyte metabolism in human spongiosa].

Prostaglandins seem to be involved in the pathogenesis of juxtaarticular osteopenia in rheumatoid arthritis. Therefore the influence of prostaglandins on in vitro electrolyte metabolism of human trabecular bone was tested. Trabecular bone was prepared from femoral heads of patients who had undergone hip replacement surgery for coxarthrosis. 500 mg samples of trabecular bone were incubated in modified Eagle's minimal essential medium. Net electrolyte movements between bone and incubation medium were measured. PGE2 caused an increase in the release of calcium (Ca) and magnesium (Mg) from bone into incubation medium as compared to controls (PGE2 1 micrograms/ml: Ca = 0.87 +/- 0.09 mmol/l*, Mg = 0.44 +/- 0.03 mmol/l*; controls: Ca = 0.81 +/- 0.09 mmol/l, Mg = 0.41 +/- 0.05 mmol/l; n = 15, *p less than 0.001). The effect of PGE2 was dose-dependent and comparable to the effect of human parathyroid hormone 1-34 (hPTH 1-34). PGE2 turned out to be the most potent prostaglandin on human trabecular bone. PGE1 and PGF2 alpha had about 50% and PGF1 alpha about 40% of the potency of PGE2. PGA1 and PGA2 had no effect. The effect of PGE2 could be completely inhibited by human calcitonin (hCT), similar to the inhibition of the effect of hPTH 1-34 by hCT. The effect of PGE2 was not further enhanced by hPTH 1-34. Magnesium metabolism was affected in all experiments in the same way as calcium metabolism. Phosphate metabolism, release of alkaline phosphatase and hydroxyproline from bone into incubation medium were not affected by prostaglandins.

Aged↗