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Biomedical subjects

W Jeske

Publications and source records attributed to W Jeske.

At least 73 records · Page 4Linked to original sources
PubMed1993

Antithrombin III- and heparin cofactor II-mediated anticoagulant and antiprotease actions of heparin and its synthetic analogues.

A chemically synthesized pentasaccharide, a specific ligand for AT III, and a synthetic, sulfated bis-lactobionic acid amide, a ligand for HC-II, were studied along with heparin to determine the relative contribution of AT III and HC II in the inhibition of protease activation in plasma. The global clotting assays (PT, APTT, Heptest, TT), amidolytic anti-IIa and anti-Xa assays, and defined biochemical systems supplemented with purified AT III and HC II were used in this study. In the plasma-based assays, heparin exhibited strong inhibition in both thrombin and Factor Xa-based assays, whereas pentasaccharide was only active in Factor Xa-based assays and lactobionic acid was only active in thrombin-based assays. In the AT III supplemented systems, heparin was able to inhibit strongly both Factor Xa and thrombin, while pentasaccharide could only inhibit Factor Xa. Lactobionic acid was ineffective at mediating its actions through AT III. In the HC II-mediated inhibition of thrombin, heparin and lactobionic acid both had strong inhibitory actions. Pentasaccharide was ineffective in this assay. All three agents failed to inhibit Factor Xa via HC II. These studies suggest that specific synthetic analogues of heparin such as the pentasaccharide and lactobionic acid can be used to study the relative contributions of AT III and HC II in the control of protease activation during thrombogenesis.

Antithrombin III↗
PubMed1993

Biochemical and pharmacologic profile of low molecular weight heparin (LU 47311, Clivarin).

1. Clivarin is a homogeneous LMWH as determined by the data obtained in molecular profiling studies. 2. The limited biochemical studies carried out indicated that this LMWH has a specific potency of 124 anti-Xa IU/mg and a weaker APTT activity of approximately 30 U/mg. 3. Assay-dependent neutralization of the in vitro effects of Clivarin was noted. Protamine preparations at equigravimetric concentrations effectively neutralized the APTT and TT effects; however, Heptest and anti-Xa effects were only partially neutralized. In contrast, heparin's effects were completely neutralized by this agent. 4. PF 4 only partially neutralized the effects of Clivarin. Assay-dependent variations were noted in this study. 5. In comparison to heparin, the hemorrhagic effects of Clivarin were much weaker. 6. Clivarin produced a dosage-dependent antithrombotic action in both the intravenous and subcutaneous studies. This agent also showed sustained activity and better bioavailability characteristics than heparin. 7. Clivarin exhibited a distinct biochemical and pharmacologic profile that may be useful in the optimization of this agent.

Animals↗
PubMed1992

An abnormality of the growth hormone/insulin-like growth factor-I axis in women with polycystic ovary syndrome due to coexistent obesity.

In order to evaluate the GH/insulin-like growth factor-I (IGF-I) axis in the polycystic ovary syndrome (PCO), 21 women aged 18-38 yr were studied. The GH responses to the GH-releasing hormone (GHRH), and plasma concentrations of IGF-I were measured in seven obese women with PCO, seven obese healthy controls without PCO, and in seven nonobese subjects. Total GH secretion, as expressed by the integrated GH response to GHRH, in PCO obese women (617.4 +/- 150 micrograms/L.min) and in obese women without PCO (327.1 +/- 161.4 micrograms/L.min) were lower than that in nonobese healthy controls (3181.4 +/- 644.3 micrograms/L.min, P less than 0.001 and P less than 0.001, respectively). Plasma concentrations of IGF-I in obese PCO women (199.5 +/- 39.1 micrograms/L), and in obese women without PCO (192.4 +/- 36.8 micrograms/L) were similar to the IGF-I levels in nonobese controls (224.3 +/- 33.2 micrograms/L). In obese women with and without PCO, a negative correlation was found between the body mass index and the peak GH responses to GHRH (r = -0.639, P less than 0.02) and between age and IGF-I levels (r = -0.520, P less than 0.05). These findings suggest that an abnormality of the GH/IGF-I axis in PCO women may be due to coexistent obesity.

17-alpha-Hydroxyprogesterone↗
PubMed1992

Clinical applications of radioimmunoassay of the alpha-subunit of glycoprotein hormones.

The radioimmunoassay of alpha-subunit adapted in our laboratory was widely evaluated. Three different antisera (anti-pituitary alpha-subunit, anti-alpha-TSH and anti-alpha-hCG), the labelled preparations of pituitary alpha-subunit and alpha-hCG, and cross-reactivity with intact glycoprotein hormones (MRC standards of LH, FSH, hCG and TSH) were tested for their potential influence on the results of the assay. The basal levels of alpha-subunit were measured in 48 healthy young men, 48 normally menstruating women, 33 menopausal women, 37 pregnant women and 70 patients with pituitary adenoma. In addition a possibility of pulsatile secretion of alpha-subunit was investigated in 9 healthy young women, the ranges of alpha-subunit concentrations found were as follow (means +/- SD): 1.2 +/- 0.4 micrograms/l--in young men, 1.1 +/- 0.4 micrograms/l--in young women, 3.2 +/- 0.7 micrograms/l--in postmenopausal women, 1-54 micrograms/l--in pregnant women, and between 2.6 and 44.0 micrograms/l in 14 of 70 patients with pituitary adenoma. There were good correlations of results for 3 different antisera and their cross-reactivity with LH, FSH, hCG and TSH were just as low. In conclusion, the alpha-subunit assay appears clinically useful and should be widely applied in routine endocrinological diagnostics.

Adenoma↗
PubMed1992

[Alcohol decreases the alpha subunit, LH and testosterone secretion in response to LH-RH].

UNLABELLED: In our previous study we showed that alcohol disturbed the circadian rhythms of LH, testosterone and its conversion to DHT. To determine the effect of LH-RH on pituitary-gonadal function before and after alcohol, 11 male volunteers aged 24-29 years (mean 25.5) were investigated. Blood for hormonal estimations was withdrawn before and 20, 30, 60, and 120 min after LH-RH. In every case, the LH-RH test was performed twice: 6 hours after placebo and, a week later, 6 hours after alcohol administered orally, in dose of 1.0 g/kg bw. The LH, FSH, alpha-subunit and testosterone concentrations were measured with radioimmunological methods. RESULTS: It was shown that alcohol significantly inhibited LH (p < 0.05), alpha-subunit (p < 0.02) and testosterone (p < 0.001) response to LH-RH stimulation, but not that of FSH.

Adult↗
PubMed1992

New long-acting bromocriptine (Parlodel MR and Parlodel LAR) in the treatment of pituitary tumours with hyperprolactinemia.

In order to assess the efficacy and tolerability of new long acting bromocriptine: Parlodel MR (oral form) and Parlodel LAR (injectable form suitable for repeatable administration) 40 patients (29 women and 11 men) with pituitary tumours with hyperprolactinemia (PRL 70 micrograms/l) were investigated in a double blind study. Patients were divided into 2 groups of 20. In the first group Parlodel R or Parlodel MR in equivalent doses was given, the other group was administered Parlodel R or Parlodel LAR. During the next 6 months 20 patients were treated with Parlodel MR and the other 20 with Parlodel LAR. In all patients pituitary and peripheral hormones, CT scan and visual fields were examined before and after 28 days of bromocriptine treatment. During the next six months 20 patients were treated with Parlodel MR while the other 20 with Parlodel LAR. Serum PRL fell in all patients and values in the normal range were obtained in 36 patients. In 30 out of 35 patients with signs of pituitary tumour in CT scan, a significant tumour shrinkage was observed. Most patients achieved considerable clinical improvement: disappearance of galactorrhoea, resumed menses in women, increased potency in men. There were no difference in efficacy in Parlodel R, Parlodel MR and Parlodel LAR, but in the case of Parlodel LAR the least number of side effects was found. Treatment with long acting bromocriptine-Parlodel MR and LAR of patients with pituitary tumours with hyperprolactinemia is an efficacious, safe and better tolerated method than Parlodel R treatment.

Adult↗
PubMed1992

Mixed pituitary tumours--effects of bromocriptine treatment: Parlodel MR and Parlodel LAR.

Majority of pituitary tumours secrete one of the named hormones: PRL, GH, ACTH, proopiomelanocortine, alpha and beta subunit of TSH, LH, and FSH. Some of those tumours secrete two or more hormones. The aim of this study was to determine the effect of bromocriptine (Parlodel MR and LAR) upon secretion of hormones and tumour size in 10 patients with mixed pituitary tumours. In all patients pituitary and peripheral hormones, CT scan and visual fields were examined before and after treatment with bromocriptine: Parlodel MR and LAR. Bromocriptine treatment decreased PRL secretion in all 10 patients; GH--in all 6 in whom it was increased; TSH--in 2, FSH--in 2 and alpha-subunit in all 6 in whom they were increased. In 5 patients treatment resulted in shrinkage of the tumour mass by 20 to 35%. In all examined subjects clinical improvement was achieved. Our results demonstrate that bromocriptine (Parlodel MR and LAR) is very effective and well tolerated in the treatment of patients with mixed pituitary tumours particularly those with hyperprolactinemia.

Adult↗
PubMed1992

The effect of oral ethanol ingestion on the diurnal neurotensin secretion in man.

Neurotensin is a tridecapeptide, present in the central nervous system and the gastrointestinal tract in man and animals. The affect of orally administered ethanol (1 g/kg body weight) on the neurotensin secretion over 24 hr period was studied in eight young healthy men. No significant circadian rhythm of neurotensin secretion was detected in the eight subjects studied. Ethanol produced a progressive rise in the plasma level of neurotensin reaching a maximum at 12:00 (13.8 +/- 8.6 pmol/l). At 12:00 and 14:00, the neurotensin concentrations were significantly higher than on the placebo day (p < 0.05). The secretion rate of neurotensin was determined approximately using the area under the curve method. Ethanol produced a transient rise in neurotensin secretion over the first 12 hrs period (08:00-20:00 h) after its administration (p < 0.02). The observation that ethanol increases transiently the neurotensin secretion in man supports the hypothesis that neurotensin may be involved in the biological effect of ethanol. The source of its secretion remains to be elucidated.

Adult↗
PubMed1992

A correlative study between cortisol and ACTH in Cushing's disease following bilateral adrenalectomy and in Nelson's syndrome.

Correlation analysis was used to investigate the interrelation between plasma ACTH and serum cortisol concentrations determined at 8:00, 12:00, 16:00 and 22:00 h in 48 patients bilaterally adrenalectomized for Cushing's disease, including 23 patients with a pituitary adenoma (Nelson's syndrome). In the patients without evidence of a pituitary adenoma a significant inverse correlation was found at 8:00, 16:00, 22:00 h and additionally when all the pairs of estimations were analyzed. In a full-blown Nelson's syndrome an inverse correlation was not proved (p = 0.05). During remission in Nelson's syndrome an inverse correlation between cortisol and ACTH concentrations was stated at 8:00 h and after the evaluation of all the pairs of estimations. The results of our studies have shown that exogenous cortisol exerts a partial inhibitory action on ACTH secretion in patients bilaterally adrenalectomized for Cushing's disease. In active Nelson's syndrome this influence is questionable, it comes however into prominence during remission.

Adrenalectomy↗
PubMed1992

Incidentally found adrenal tumours: results of investigation of the pituitary-adrenal axis.

In the last 7 years 64 patients (48 women, 16 men, aged 25-75 yrs) with incidentally found asymptomatic adrenal tumours have been observed in the Department of Endocrinology. In 11 patients a routine clinical investigations revealed metastatic tumours at the adrenal glands. In the remaining 53 patients the diameter of the adrenal tumours was < or = 3 cm. Only two of them were treated surgically; the rest has been observed regularly and ultrasonographic examinations have been repeated every 3 to 6 months. Twenty three patients with adrenal tumours < 3 cm of diameter were treated by surgery. The macroscopical examination revealed adrenal cortical adenoma in 11 cases, adrenocortical carcinoma in seven, and pheochromocytoma in 5 patients. The investigation of the pituitary-adrenal system (urinary excretion of 17-OHCS before and during dexamethasone administration, 17-KS, "free" corticosteroids, plasma ACTH, cortisol and S-DHA levels) did not reveal any abnormality except that in 10 patients the plasma ACTH concentration was low, especially in the morning. These values were significantly lower as compared with the remaining patients and with control group. One of the possible interpretations is a pituitary suppression by only periodically increased concentrations of the corticosteroids.

Adrenal Gland Neoplasms↗
PubMed1992

Lower 24-hour growth hormone levels in type I diabetics responding to thyrotropin-releasing hormone (TRH).

The aim of the study was the evaluation of growth hormone secretion under physiologic conditions in two groups of type I diabetics: responding and nonresponding to TRH stimulation. Both groups matched for age and metabolic control of diabetes were studied during 24-hours and after GHRH stimulation. The whole diabetic group (n = 18) showed circadian rhythm of GH secretion with mesor value of 4.03 micrograms/l. TRH-responders had lower mesor GH value than TRH-nonresponders: 3.53 vs. 5.32, p < 0.05. GH response to GHRH was almost identical in both groups. C-peptide level was lower in TRH-responders: 0.16 vs. 0.56 microgram/l, p < 0.05. No correlation was found between growth hormone response and HbA1 and C-peptide levels. It is concluded that type I diabetics responding to TRH stimulation are characterized by lower mean 24-hour GH levels and lower C-peptide values.

Adult↗
PubMed1992

Thyrotropin-releasing hormone (TRH) does not suppress growth hormone response to L-dopa in insulin-dependent diabetes mellitus.

Thyrotropin-releasing hormone (TRH) blunts growth hormone (GH) response to various stimuli in normal subjects. We were interested if similar inhibitory effect of TRH could be demonstrated in diabetes mellitus where GH is abnormally regulated. In this study we compared the effect of TRH on GH response to L-dopa in normal and diabetic subjects. TRH 0.2 mg iv blunted GH response to L-dopa 0.5 g p.o. in normal subjects with peak GH values 13.1 and 7.3 micrograms/l, p < 0.05. In the diabetics no inhibitory effect of TRH was demonstrated and GH was even paradoxically increased after TRH: 14.9 and 21.9 micrograms/l, p = NS. Lack of inhibitory effect of TRH was more pronounced in patients with proliferative retinopathy. It is concluded that TRH has no inhibitory effect on L-dopa-induced GH response in diabetic subjects. This finding provides further evidence for disturbed GH regulation in diabetes mellitus.

Adult↗
PubMed1992

Measurement of bone mineral density (BMD) with quantitative computed tomography (QCT) in postmenopausal osteoporosis: effect of estrogen.

UNLABELLED: To determine the efficacy of the estrogen replacement therapy (ERT) on the bone mineral density (BMD) measured with quantitative computed tomography (QCT) in postmenopausal osteoporosis 16 women aged 46-72 were examined. They were divided into two groups: 8 women treated with conjugated estrogens (Group I) and 8 who did not received ERT (Group II). In all 16 patients the serum hormonal concentrations (LH, FSH and estradiol) were measured with radioimmunological methods. The bone densitometry was performed in all of them using the single-energy computed tomography (QCT) with the computer Picker 1200. Bone mineral density was measured in three lumbar vertebra (L1-L3) and expressed in milligrams K2HPO4 per ml. The bone mineral density (BMD) was statistically significantly higher in the estrogen treated group (Group I) in every vertebra compared with that of controls (Group II). The serum FSH concentration was statistically significantly lower in the ERT group (Group I) and a statistically significant correlation between FSH level and average BMD (Lmean) was present. IN CONCLUSION: 1. the ERT is very efficacious in preventing bone loss in postmenopausal women; 2. measurement of BMD in lumbar vertebra L1 or L3 may be a sufficiently reliable and accurate, cost-effective and time-saving method of screening for osteoporosis; 3. the serum FSH determination seems to be useful in monitoring of the estrogen therapy for postmenopausal osteoporosis.

Aged↗
PubMed1992

[Inhibition of growth hormone (GH) response to GHRH in diabetes mellitus type 1 after blockade of the cholinergic system with pirenzepine].

The effect of pirenzepine, a peripheric cholinergic antagonist, on GHRH-induced GH secretion was studied in 10 type I diabetic subjects and 8 healthy controls. GH response was significantly greater in diabetics than in the healthy controls (p < 0.02) with peak values of 59.6 and 15.9 ng/ml, respectively. Pirenzepine 20 mg in given 15 min before GHRH inhibited GH response in both groups. In diabetics GH response calculated as area under curve (AUC) was inhibited from 3666 to 260 ng/ml. min (p < 0.001) and in the controls from 831 to 255 ng/ml. min (p < 0.05). The great efficacy of pirenzepine in inhibiting GH hypersecretion in type I diabetes may find a clinical application in future.

Adult↗