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Biomedical subjects

R Lang

Publications and source records attributed to R Lang.

At least 19 recordsLinked to original sources
PubMed1979

[Hemodynamic and humoral changes during administration of a sympathomimetic and a sympatholytic drug with special notes on the regulation of renin release (author's transl)].

Studies in normal volunteers documented the positive inotropic effects of Etilefrin-HCL, a direct sympathomimetic drug, with increases of systolic blood pressure, renal blood flow and glomerular filtration rate. Sodium and potassium excretion as well as serum potassium decreased. After an additional injection of Metoprolol, a beta 1-sympatholytic drug, blood pressure, renal blood flow and glomerular filtration rate normalized, whereas electrolyte excretion decreased further. Renin release was decreased during administration of Etilefrin as well as during combined Etilefrin and Metoprolol application. Reziprocal to changes of blood pressure, plasma norepinephrine concentration decreased during Etilefrin and increased during combined administration of Etilefrin and Metoprolol. The results lead to the following interpretation: Changes of blood pressure and renal hemodynamics are mediated by beta 1-adrenergic effects of Etilefrin, whereas the electrolyte excretion is influenced by beta 2-adrenergic effects. Renin release seems to be influenced by beta 1 as well as beta 2-adrenergic receptors.

Adult↗
PubMed1979

Sympathetic activity and transcendental meditation.

Ten male advanced meditators and ten male long-term meditators subjected themselves four times to slight physical exercise following a period of rest, meditation or reading. Daily urine excretions of catecholamines and VMA were determined in both groups. On the experimental days 4-hour urine specimens, one before and one after the experiments, were again collected for analysis. During the experiments blood pressure and heart rate were measured continuously and blood samples were taken for plasma catecholamine levels immediately before and after the physical exercise. Daily catecholamine and VMA excretions showed to be higher in advanced meditators. During the experiments the pattern of noradrenaline, adrenaline and VMA excretions were different in both groups, long-term meditators showing a higher adrenaline excretion after exercise. After the resting period there was in both groups a similar increase of plasma catecholamine levels during exercise. However, after meditation the advanced meditators showed a significant increase in plasma noradrenaline and no further increase in plasma noradrenaline level during the following physical exercise. Also after the reading period differences between both groups in plasma catecholamine levels during exercise could be observed. In advanced meditators heart rate reduction after meditation was about 9% and diastolic blood pressure was slightly raised. The preceding conditions of rest, meditation or reading had a significant different influence on the behaviour of heart rate and blood pressure during the following physical exercise and this pattern was different for both groups.

Adult↗
PubMed1979

Differential and integral corticosteroid feedback effects on ACTH secretion in hypoadrenocorticism.

Recent work suggests the existence of a dual corticosteroid feedback mechanism of stress-induced ACTH secretion in the rat. This possibility led us to study the kinetics of suppression of ACTH levels by corticosteroid administration in patients with nonstress ACTH hypersecretion secondary to hypoadrenocorticism. Cortisol was administered according to different protocols, which were chosen to provide extreme variations of the input signal. By this means, two phases of suppression of ACTH levels could be differentiated. A first decrease occurred without latency whenever, and as long as, plasma cortisol levels were rising. There was a linear regression between the logarithm of the increments in cortisol concentrations and the decrease in ACTH levels per minute (r = 0.951) (differential or rate-sensitive feedback mechanism). Neither the absolute doses of cortisol, nor plasma cortisol concentrations were closely correlated with the degree of suppression of ACTH by this rapid mechanism. A second decrease in ACTH levels began congruent with30 min after corticosteroid administration. In this case there was a significant linear regression between the degree of inhibition of ACTH levels and the cortisol doses (r = 0.997) (integral or dose-sensitive feedback mechanism). The dose-sensitive feedback effects of dexamethasone were less than might have been predicted from its relative anti-inflammatory potency. No rate-sensitive effects were seen with dexamethasone doses of 1.0 or 1.25 mg.

Adrenal Cortex Hormones↗
PubMed1979

[Alveolysis in adolescents: prevalence and correlation with the DMF index, the OHI-S index and the PM index according to sex, age and occupation (Geneva 1970-1972)].

A randomized sample of 1392 girls and boys, 16 to 20 years old and living in the canton of Geneva have been studied through their own history, clinically and radiologically in 1970-72 during an epidemiological and socio-economical study. The rate of alveolar bone resorption (radiographic method of Marshall-Day and Shourie, with Schei grid), the degree of gingival inflammation (PM index), the oral health (OHI-S index) and the carious frequency (DMFS index) have been determined. For the same sample, an indication of the duration of caries prevention through fluoride tablets, the frequency of daily toothbrushing and the dento-facial anomalies (Angle classes) were known. Through statistical analysis, it was shown that the mean rate of alveolar resorption was 0.85 (standard deviation 1,99) for the whole sample, that 24,16% of the subjects had a zero rate, 90% of the children having a rate of no more than 3,74 and that the maximum observed rate was 20. On the other hand, this bone resorption rate was statistically significantly correlated with the PM index and the OHI-S index. However no significant correlation has been shown between alveolar resorption and the other oral characteristics such as carious attack, toothbrushing, duration of caries prevention, dento-facial anomalies.

Adolescent↗
PubMed1979

[Cystometric investigations of neurogenic bladder-dysfunction in children (author's transl)].

Clinical and cystometrical studies were performed in 48 patients with myelomeningocele. From the clinical point of view four of the patients were completely continent. Fiften patients showed a so called "social continence" with periods of continence lasting for more than two hours (40%). Cystomanometric evaluations, however, revealed that there was a complete continence only in one of the 48 patients. Twenty-one patients showed a spastic or reflex bladder (44%), twentysix (54%) an adynamic bladder. The so called "social continence" could be observed as well in spastic-as in adynamic bladders. The most important parameters to realize neurogenic disturbances of micturition is the dyssynergia of the contraction of the detrusor muscle and the relaxation of the external vesical sphincter. Considering this, Stark's classification of adynamic and spastic bladders according to amplitude of the contractions of the detrusor muscle is helpful only in combination with the cystometrical and myographical datas of the bladder outlet.

Adolescent↗
PubMed1978

[The importance of changes in whole-body balance of sodium and noradrenaline in essential hypertension (author's transl)].

In 22 patients with essential hypertension plasma levels and urine excretions of sodium and noradrenaline were studied before, during and after long-term beta-blockade with pindolol. The relation between mean blood pressure and the quotient of sodium-/noradrenaline-excretion changed during treatment (placebo r=-0.34; pindolol r=+0.31). During placebo there existed a significant (p is less than 0.03) correlation between blood pressure and sodium-excretion which disappeared during beta-blockade. No correlation between blood pressure and noradrenaline was seen during placebo, whereas during beta-blockade a significant (p is less than 0.003) correlation was observed. In contrast to the placebo period there was a significant positive correlation between sodium- and noradrenaline-excretion during long-term treatment with pindolol. It is concluded that whole-body balance of sodium and noradrenaline is an important factor in essential hypertension.

Adrenergic beta-Antagonists↗
PubMed1978

[A field study with the combination of Pindolol and Clopamid in antihpertensive therapy (author's transl)].

In a field study comprising 678 patients with arterial hypertension efficacy and tolerance of the stable combination VKB 105 consisting of 10 mg Pindolol (Visken) and 5 mg Clopamid (Brinaldix) were investigated. Treatment with 1--2 tablets of VKB per day resulted in a successful therapy in 94% of all patients corresponding on the average to a reduction in blood pressure to 145/85 mm Hg within 14 days. In mean arterial pressures ranging between 120 and 170 mm Hg a positive linear relationship between the individual initial value and the hypotensive effect of the combination could be observed. A controlled omission trial disclosed qualitatively the respective contribution to the effect of the two components Pindolol and Clopamid. With a systematic case control of the serum potassium under the combined therapy with VKB 105 and during a monotherapy with Clopamid and antihypokalaemic effect of Pindolol could be demonstrated diminishing the tendency for potassium loss. The result revealed a far-reaching potassium neutrality of diuresis-depending stimulation of renin by the beta-receptor blocker. In 61 patients altogether subjective side-effects could be recorded, such as vertigo (5%), palpitations (2.8%), fatigue (2%), insomina (1.9%), nausea (1.7%) and vomiting (0.8%). Laboratory controls gave no indication for clinically relevant changes.

Adrenergic beta-Antagonists↗
PubMed1978

Mammalian spot test with moxnidazole, a 5-nitroimidazole.

Moxnidazole [3-(5-nitrol-1-methyl-2-imidazolyl)-methyleneamino-5-morpholinomethyl-2-oxazolidinone, HCl], known to be mutagenic in microbial tests and Drosophila, induced genetic alterations in somatic cells of mice. Ethyl methanesulfonate (EMS) served as positive control.

Animals↗
PubMed1978

Strategies for detecting heritable translocations in male mice by fertility testing.

Data from a heritable translocation test were analysed to estimate the best rule for classification of F1 males in normals or partially sterile translocation carriers according to litter size or numbers of live and dead implants per mating. Six rules were compared for classification with up to three litter sizes per F1 male observed. The results indicate that a translocation rate of 2%, or at best of 1%, can be detected with reasonable cost.

Animals↗