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Biomedical subjects

J Beyer

Publications and source records attributed to J Beyer.

At least 361 records · Page 20Linked to original sources
PubMed1987

The neurologic examination in patients with probable Alzheimer's disease.

Abnormal findings on a standardized neurologic examination were compared between patients with a clinical diagnosis of probable Alzheimer's disease (AD) and healthy control subjects. Aside from mental status findings, the most useful examination findings for differentiating AD from control subjects were the presence of release signs, olfactory deficit, impaired stereognosis or graphesthesia, gait disorder, tremor, and abnormalities on cerebellar testing. These abnormalities probably reflect the different areas of the central nervous system that are affected pathologically in AD. In the clinical diagnosis of AD, particular attention should be given to these aspects of the neurologic examination.

Aged↗
PubMed1987

HIV-specific antibody among voluntary blood donors in Lower Saxony (FRG).

Anti-HIV test results of the Red Cross Blood Transfusion Service of Lower Saxony from 1 June 1985 to 31 July 1986 inclusive were analysed retrospectively. Nine out of 70,936 donors who had not donated blood before 1 June 1985 (first-time donors) and 9 out of 261,231 donors who had donated blood before this date (repeating donors) were found anti-HIV confirmed positive at the time of the first blood donation during the study period. The prevalence of HIV antibody in first-time donors was significantly higher than in repeating donors (p less than 0.01). It was concluded that some members of risk groups used blood donation to obtain an anti-HIV test result. One out of 30,300 blood donations was confirmed anti-HIV positive. The results of this study justify the transfusion of blood donations that are reactive only in the initial ELISA test.

Antibodies, Viral↗
PubMed1987

Naloxone increases the response of growth hormone and prolactin to stimuli in obese humans.

Opiates stimulate the growth hormone and prolactin responses to stimuli in non-obese humans. Obese patients, however, show lowered growth hormone and prolactin responses and raised beta-endorphin levels. We therefore investigated the effect of the opiate antagonist naloxone on the stimulated growth hormone and prolactin secretions in a controlled double-blind study in obese patients. All patients received 200 micrograms TRH and 0.5 g/kg b.w. arginine together with 2 mg of naloxone or placebo i.v. in a randomized sequence. The TRH- and arginine-induced increases in prolactin and growth hormone were significantly greater after administration of naloxone (p less than 0.05). Naloxone also produced a significant increase in ACTH, cortisol and beta-endorphin when compared with placebo. TSH, triiodothyronine, thyroxine, insulin, glucagon and blood glucose showed no significant differences between both days of the trial. The effect of naloxone on growth hormone and prolactin secretions in obese humans can thus be regarded as a partial normalization. We therefore conclude that the hypothalamic regulatory disturbance of growth hormone and prolactin secretions in the obese could be caused by raised opiate levels.

Adrenocorticotropic Hormone↗
PubMed1987

The influence of parathyroid hormone and its fragments on results from midregion and C-terminal specific radioimmunoassays.

We compared a midregion (44-68) human parathyroid hormone (hPTH) specific radioimmunoassay (M-RIA) with a C-terminal (65-84) hPTH specific radioimmunoassay (C-RIA). The M-RIA discriminated 21 of 23 patients with primary hyperparathyroidism from 95 normals (normal range: 22.4-106.5 pmol/l). With the C-RIA 12 patients including the 2 patients not discriminated by the M-RIA had immunoreactive PTH (iPTH) values within the normal range of this assay (normal range: undetectable to 88.6 pmol/l). To investigate the reasons for these different abilities of separation, hyperparathyroid sera were subjected to gel-filtration and analyzed using the two assays. Intact PTH appeared to have a major influence on the immunoreactivity of circulating PTH in the M-RIA. In contrast, the C-RIA showed the highest immunoreactivity with midregion-C-terminal PTH fragments. Hyperparathyroid sera not discriminated by the C-RIA but with elevated iPTH in the M-RIA showed decreased amounts of midregion-C-terminal PTH fragments, while intact PTH comprised the highest amount of total circulating PTH immunoreactivity in the M-RIA. From the present results we conclude that the superiority of the M-RIA is due to the determination of intact PTH which is preferable for clinical measurements with relation to the diagnosis of primary hyperparathyroidism.

Adolescent↗
PubMed1987

The effect of high parathyroid hormone concentration on calcitonin in patients with primary hyperparathyroidism.

Serum calcitonin (CT), parathyroid hormone (PTH), and calcium levels were measured in 23 patients with primary hyperparathyroidism. PTH was determined by a midregion (M-RIA) and a carboxyl-terminal (C-RIA) specific PTH-RIA. Only 2 patients had elevated CT levels. In contrast to the findings in 46 healthy controls, the CT levels did not correlate with calcium levels. Patients who had the highest iPTH values showed a negative correlation between CT and iPTH (M-RIA (n = 7): R = -1.0000, p less than 0.001; C-RIA (n = 13): R = -0.5604, p less than 0.05). The results of the C-RIA were subtracted from those of the M-RIA. In 12 patients with the highest levels of intact PTH (M-RIA - C-RIA), serum PTH concentration was inversely correlated with serum CT concentration (R = -0.7343, p less than 0.01). In the same patients a negative correlation between CT and calcium was found (R = -0.6783, p less than 0.02). These findings suggest that high PTH levels may have a direct suppressive effect on CT concentration and this may be, at least in part, responsible for failure of CT concentrations to rise in many patients with primary hyperparathyroidism.

Calcitonin↗
PubMed1987

Suppression of growth hormone and somatomedin C by long-acting somatostatin analog SMS 201-995 in type I diabetes mellitus.

The effect of a new long-acting somatostatin analog SMS 201-995 (SMS) on hormonal mechanisms controlling the glucose metabolism was tested in 8 type I diabetics over a 3-day period. In addition to dietary measures and conventional insulin therapy, the patients received a subcutaneous dose of 50 micrograms SMS three times daily for 3 days. Serum growth hormone (GH) was measured at various intervals throughout the investigational period. Glucagon, somatomedin C (SM-C), triiodothyronine, thyroxine, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were also determined before and at the end of the therapy with SMS. Basal GH and plasma SM-C had decreased significantly (p less than 0.05 and p less than 0.01, respectively) by the 3rd day. In all cases the insulin requirements could be reduced (mean 28%) without deterioration of the metabolic control. Moreover, blood glucose profiles showed a tendency to lower postprandial peaks after SMS treatment. Glucagon, triiodothyronine, thyroxine, LH, FSH and PRL showed no significant changes. No side effects or alterations in laboratory chemistries were recorded. Dampening of glucose oscillations and counterregulatory mechanisms, and reduction of insulin dosage by SMS may enable a better control of unstable diabetes. Its slow plasma clearance and long action compared to the native peptide will warrant the use of this analog as a additive to standard diabetes therapy in more prolonged trials.

Adult↗
PubMed1987

Effects of high and low doses of methimazole in patients with Graves' thyrotoxicosis.

In spite of the long-established use of antithyroid drugs, there are many unsettled questions connected with this treatment of Graves' disease. There is a lack of controlled prospective trials studying the results of antithyroid drug therapy while considering the many variables such as disease heterogeneity, regional differences, drug dosage and duration of treatment. Therefore, a multicenter study has been set up in order to compare the effects of two fixed doses of methimazole (10 vs 40 mg) with thyroid hormone supplementation on the clinical, biochemical and immunological course of Graves' disease and on remission rates. Experience accumulated so far suggests that treatment is safe using either 10 or 40 mg of methimazole. While there is a tendency for an advantage of the higher dose within the first weeks (higher effectiveness in controlling hyperthyroidism), this difference is not significant. The impact of dosage on remission rates remains to be shown.

Adult↗
PubMed1987

Excretion and metabolism of phenol, 4-nitrophenol and 2-methylphenol by the frogs Rana temporaria and Xenopus laevis.

1. Rana and Xenopus excrete 90-95% dose, and metabolize 50-65% dose of phenol, 4-nitrophenol and 2-methylphenol within 24 h, to about the same extent. 2. Kinetic data for the excretion of phenols from both species fit a two-compartment model. The elimination constants of Rana and Xenopus are not significantly different. 3. Metabolism is mostly conjugation by glucuronidation and sulphation of the original phenols. Additionally, oxidations leading to dihydroxyphenols and benzoic acid from 2-methylphenol, and reduction of 4-nitrophenol occur, followed by conjugation. 4. There is an important difference between the metabolite patterns of Rana and Xenopus in that the latter is unable to glucuronidate phenols. As the amount of metabolites produced is similar in both species. Xenopus compensates for its inability to glucuronidate by increasing other metabolites.

Animals↗
PubMed1986

Fine-needle biopsy of parathyroid adenomas.

High-resolution real-time sonography was performed in 15 cases of clinically and chemically suspected primary hyperparathyroidism and in 20 patients with different thyroid nodules. The suspected enlarged parathyroid glands and the thyroid nodules were percutaneously punctured under sonographic control. Concentrations of parathyroid hormone, human thyroglobulin, and human calcitonin were measured in the aspirate, and immunocytology was performed. The mean concentration of the aspirated parathyroid hormone in the parathyroid glands was 4,013.6 pmol/l +/- 4,519 (SD) as compared with 14.9 pmol/l +/- 8.7 in the thyroid nodules. Thyroglobulin was present in the aspirated fluid of parathyroid adenomas located behind the thyroid (mean +/- SD, 398.1 ng/ml +/- 317). In comparison, the aspirated thyroglobulin from the thyroid nodules averaged 9,689.7 ng/ml +/- 3,732. Immunocytology for parathyroid hormone was positive in 14 of the 15 biopsied specimens. Of 15 patients who were scanned for suspected hyperparathyroidism, six had concomitant thyroid nodules. It is concluded that the measurement of high concentrations of parathyroid hormone in the aspirate from a cervical mass, with sonographic control of needle position and/or positive immunocytology provides absolute localization of parathyroid tissue.

Adenoma↗
PubMed1986

Long-term treatment of acromegaly with the somatostatin analogue SMS 201-995 over 6 months.

This study examined the effects of the long-acting selective mini somatostatin analogue (SMS) 201-995 in two acromegalic patients who were treated for 3 and 6 months, respectively. During treatment the mean growth hormone levels (25.3 and 20.8 ng/ml vs 5.9 and 10.6 ng/ml) and somatomedin C levels (6.2 and 6.2 IU/ml vs 3.3 and 3.8 IU/ml) decreased and the patients reported an improvement in their symptoms. The main side effect was an increase in stool fat excretion which did exceed the normal range (less than 7 g/day) in one patient. Five acromegalics who received 2 X 50 micrograms SMS 201-995/day for 5 days showed a significant increase of stool fat excretion (1.7 vs 3.5 g/day; p less than 0.05). Fasting blood glucose levels, glucose tolerance, and glycosylated hemoglobin were not essentially effected. It is concluded that SMS 201-995 offers new possibilities in the treatment of acromegaly. The gastrointestinal and diabetogenic side effects of this substance, however, should be carefully monitored.

Acromegaly↗
PubMed1986

The secretion of parathyroid hormone and its fragments from dispersed cells of adenomatous parathyroid tissue at different calcium concentrations.

The effect of varying calcium concentrations on PTH release from dispersed cells of adenomatous parathyroid tissues (n = 15) was studied. During high calcium concentrations PTH secretion was inhibited up to 62.5% as compared to low calcium concentrations. There was no correlation between iPTH secretion rate and suppressibility. Each adenoma had a different iPTH secretion rate. Three adenomas showed a high suppressibility (28.0%, 53.8%, and 62.5%). The supernates of their media were chromatographed and examined by midregion and C-terminal specific PTH-RIAs. Carboxyl-terminal PTH fragments were found to be released by two adenomas. There was no evidence for the release of midregion PTH fragments. Comparison of incubation media revealed that the adenoma with the lowest suppressibility released the highest amount of intact PTH (per 100,000 cells/ml). This adenoma exclusively secreted intact PTH, whereas PTH fragments were only released from two adenomas with higher suppressibility. In these media the ratio of PTH fragments to intact PTH increased with the calcium content of the media. The ratio was also dependent on the suppressibility of the adenomas; i.e. the ratio was greater when the suppressibility was higher. This suggests that in adenomas the intracellular hormone degradation is responsible for the degree of PTH suppression. As the suppressibility of PTH secretion is reduced in hyperfunctioning parathyroid tissue, diminished intracellular hormone degradation seems to be involved in the pathogenesis of primary hyperparathyroidism.

Adenoma↗
PubMed1986

Fasting and feeding variations of insulin requirements and insulin binding to erythrocytes at different times of the day in insulin dependent diabetics--assessed under the condition of glucose-controlled insulin infusion.

Nine insulin-dependent diabetic patients were examined for insulin requirement, counterregulatory hormones, and receptor binding during their connection to glucose-controlled insulin infusion system. They were of 103% ideal body weight. A diet of 45% carbohydrate, 20% protein and 35% fat was divided into three meals and three snacks averaging the daily calorie intake of 1859 kcal. Following an equilibrating phase of 14 hours after the connection to the glucose-controlled insulin infusion system the blood samples were taken at 0800, 1200 and 1800. The insulin infusion rate increased at 0300 in the early morning from 0.128 mU/kg/min to 0.221 mU/kg/min (P less than 0.02). The postprandial insulin infusion rate jumped from 0.7 U/h (0700-0800) to 7.5 U/h (0800-0900). The calorie related and carbohydrate related insulin demands after breakfast were also highest and declined after lunch respectively (1.16 uU/kg/min kj vs. 0.61 uU/kg/min kj, P less than 0.05 and 236 mU/g CHO vs. 129 mU/g CHO and 143 mU/g CHO). Of the counterregulatory hormones the cortisol showed a significant diurnal rhythm to insulin demands. The insulin tracer binding was higher at 0800 before breakfast than that at 1200 before lunch (P less than 0.05). The increased binding could be better attributed to receptor concentration change than to affinity change. The cause of insulin relative insensitivity in the morning could be due to altered liver response to the cortisol peak in type 1 diabetics. The preserved variation of insulin binding in our patients might be referred to feeding.

Circadian Rhythm↗
PubMed1986

[Selective blood sampling from the inferior petrosal sinus using digital subtraction angiography].

Simultaneous bilateral venous sampling of blood from the inferior petrosal sinuses helps in the differentiation between peripheral and central ACTH hypersecretion. One can also locate the site of a hormonally active hypophyseal micro-adenoma that cannot be demonstrated by other methods. The authors have experience with fifteen patients and discuss the indications, technique and problems as well as the advantages of using digital subtraction angiography.

Adenoma↗