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Biomedical subjects

H Frandsen

Publications and source records attributed to H Frandsen.

43 records · Page 3Linked to original sources

Plasma glucagon and glucose recovery after hypoglycemia: the effect of total autonomic blockade.

The role of the autonomic nervous system in the glucagon response to hypoglycemia has not been fully clarified. We have studied the effect of total pharmacological blockade of the autonomic nervous system (concomitant alpha- and beta-adrenergic blockade with simultaneous atropine injection) and of isolated alpha-adrenergic blockade on hormonal responses to hypoglycemia and on blood glucose recovery after hypoglycemia in healthy subjects. Neither of the pharmacological blockades had any significant effects on plasma glucagon responses to hypoglycemia nor had they any effect on the rate of blood glucose recovery after hypoglycemia. We conclude that the autonomic nervous system has no major influence on the glucagon response to hypoglycemia in healthy man. Changes in autonomic nervous activity are not essential for blood glucose recovery after hypoglycemia in healthy man.

Adult↗

Plasma volume substitution does not inhibit plasma noradrenaline and muscle nerve sympathetic responses to insulin-induced hypoglycaemia in healthy humans.

Microelectrode recordings of muscle nerve sympathetic activity and measurements of venous plasma noradrenaline have indicated increased sympathetic outflow during acute hypoglycaemia. Plasma volume reduction during hypoglycaemia, as evidenced by increasing peripheral venous haematocrit might underly the sympathetic activation. To study the effect of prevention of plasma volume reduction during hypoglycaemia, saline containing albumin was infused intravenously in healthy adult volunteers during hypoglycaemia. Hypoglycaemia was induced by an intravenous injection of soluble insulin in a dose of 0.15 IU/kg body weight. Peripheral venous plasma noradrenaline concentrations were identical in experiments without and with plasma volume substitution. Muscle nerve sympathetic activity increased to the same extent during hypoglycaemia with and without plasma volume substitution. It is concluded that increased plasma noradrenaline concentrations and enhanced muscle nerve sympathetic activity during insulin-induced hypoglycaemia in man are not consequences of plasma volume reduction.

Adult↗

Dihydrotestosterone measured in core biopsies from prostatic tissues.

Dihydrotestosterone (DHT) levels were measured and related to the content of DNA in 10- to 15-mg tissue samples obtained by punch biopsies from the prostatic gland. The aim of the study was to provide an opportunity to detect the variation of dihydrotestosterone (DHT) in prostatic tissue on endocrine manipulations in phase III studies of metastatic prostatic cancer. DHT was assayed in ranges of 27.9 to 102.9 pg/ml or when related to DNA from 0.57 to 4.00 pg/micrograms DNA by modifying a commercial testosterone/dihydrotestosterone kit. Preliminary clinical results from nine patients with prostatic cancer and eight with benign hyperplasia showed a significantly lower DHT/DNA ratio in prostatic cancer. The predictive value of the histological grading was improved by estimates of the weighted mean nuclear volume. The trend that mean nuclear volume of prostatic cancer exceeded the mean nuclear volume of hyperplasia was clear, and a significantly larger nuclear variation was demonstrated in the malignant specimens. Neither the DHT/DNA ratio nor the mean nuclear volume appears to be sufficient to guide the handling of individual patients, but the described methods enable us by repeated measurements to follow the course of disease and response to treatment.

Aged↗

An effect of predilution on VIII:C determination by the one-stage assay.

Factor VIII concentrates are usually prediluted in Owrens buffer, before use of the one-stage assay for VIII:C determinations. We found that predilution of high purity Factor VIII concentrates in fresh VIII:C deficient plasma gave VIII:C estimates about 3 times higher than predilution in Owrens buffer. Predilution in reconstituted lyophilized VIII:C deficient plasma gave VIII:C estimates about 1.6 times higher. Likewise the VIII:C in a plasma sample can be estimated to e.g. 0.03, 0.06 or 0.10 IU/ml depending on whether the reference curve is established by predilution of the reference plasma in fresh VIII:C deficient plasma, in reconstituted lyophilized VIII:C deficient plasma or in Owrens buffer, respectively. It is shown that the major part of the differences between the effects of the various prediluents on the VIII:C determinations, can be accounted for by differences in the content of Factor V, Fibrinogen, and vitamin K dependent coagulation factors in the assay mixtures.

Citrates↗

In utero reproductive study in rats exposed to nonylphenol.

Alkylphenol ethoxylates are widely used non-ionic surfactants. Nonylphenol ethoxylate constitutes 82% of the production of all alkylphenol ethoxylates and the breakdown product of nonylphenol ethoxylate, nonylphenol (NP) has been shown to be estrogenic in both in vitro and in vivo screening assays. To determine the potential reproductive toxicity of NP, a one-generation in utero study was conducted. Rats were dosed from gestation day 11 through 18 with NP at 3, 15, or 75 mg/kg/day or diethylstilbestrol (DES) at 30 microg/kg/day. DES was used as a positive control. Both substances were given orally by gavage. Male offspring were sacrificed at postnatal day (PND) 11, 21, or 110 and reproductive parameters were evaluated. Pup birth weight and body weight and percent motile sperm at age of 110 day were significantly reduced by DES. The absolute weight of the right epididymis was significantly reduced in the DES group. The absolute weight of the right epididymis were also significantly decreased in the animals exposed to 75 or 15 mg/kg/day NP, effects which disappeared when organ weight was related to body weight. This study showed a dose-dependent effect of nonylphenol on male reproductive development at doses of 75 and 15 mg/kg bw/day based on absolute epididymal weight.

Animals↗