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Biomedical subjects

L Hyldstrup

Publications and source records attributed to L Hyldstrup.

51 records · Page 3Linked to original sources
PubMed1987

Plasma tetranectin in healthy male and female individuals, measured by enzyme-linked immunosorbent assay.

Tetranectin is a novel protein recently isolated from human plasma. It is a tetramer, composed of four identical, non-covalently bound, 181-amino-acid polypeptide chains (Mr = 20,100). We report here the quantification of plasma tetranectin in 457 healthy individuals, aged from birth to 85 years, using a newly developed sensitive and reproducible enzyme-linked immunosorbent assay (ELISA). Tetranectin was demonstrable in all subjects investigated, and within each sex and defined age group the concentration was well controlled within a relatively narrow range. The mean plasma tetranectin level in newborn infants (cord plasma) was about 8 mg/L. This was significantly less than in later life, during which mean plasma tetranectin level varied between 10 and 12 mg/L. After the age of 9 years, tetranectin level was continuously higher in males than in females, but the variations through the span of life were almost identical. Thus, a transitory increase in plasma tetranectin was observed in early puberty, reaching its climax about the age of 11 to 12 in girls and 14 to 15 in boys. A quantitatively similar, additional peak was observed during the period of 50 to 59 years of age in both sexes, whereupon the tetranectin concentration gradually decreased. The biologic function of tetranectin remains to be elucidated. Recently, we have reported that tetranectin is contained within hepatocytes and various endocrine cells, all known to process peptide hormones or glucoproteins. We propose that tetranectin may be involved in intracellular and extracellular serine protease-mediated proteolysis.

Adolescent↗
PubMed1986

Increased parathyroid hormone as a consequence of changed complex binding of plasma calcium in morbid obesity.

To evaluate whether changed plasma calcium binding might lead to a secondary increase of parathyroid hormone in morbid obesity, fasting measurements of serum ionized, ultrafiltrable and total calcium, calcium binding substances, and parathyroid hormone were undertaken in age- and sex-matched groups of obese (n = 44) and normal weight subjects (n = 52). The 24-hour urinary calcium excretion and clearance of creatine were also measured. Calcium binding to proteins was changed. Serum total proteins and protein-bound calcium did not differ, but serum albumin was decreased in obesity. Consequently, obese subjects did not reveal the normal dependency of protein-bound calcium upon albumin. Calcium binding to other substances was also changed. Serum phosphate and bicarbonate were decreased, while the concentrations of citrate, lactate, acetoacetate, 3-hydroxybutyrate, free fatty acids, and urate were all increased, leaving the total concentration of plasma complex-bound calcium unchanged. Nevertheless, these reciprocal changes increase the concentrations of less readily reabsorbable anions in the renal ultrafiltrate. The changed pattern of calcium binding in serum of the obese subjects may serve to explain our findings of increased urinary calcium excretion, lowering of serum ionized calcium and increased parathyroid hormone levels, changes being significantly correlated with degree of overweight.

Adult↗
PubMed1986

Seasonal variations in indices of bone formation precede appropriate bone mineral changes in normal men.

In 10 normal males aged 23-50 years measurements of serum alkaline phosphatase (s-AP) and the 24-h whole body retention of 99mTc-diphosphonate (WBR), as indices of bone formation, and the fasting urinary hydroxyproline:creatinine ratio (OHPr:Cr), as an index of bone resorption, were performed monthly from January 1983 to May 1984. Bone mineral content of the distal forearm (BMC) was measured in the middle of each quarter. From January to May BMC exhibited a reproducible, significant average increase of 2.5%, returning to baseline level between May and August. During the first quarter of both 1983 and 1984 a significant increase in s-AP and WBR was seen. Subsequently, during the second quarter of 1983, these variables fell below the mean of the year. Confirming their interrelationship, the deviations of s-AP and WBR were positively correlated throughout the study period (r = 0.51, P less than 0.05). Since the urinary OHPr:Cr ratio remained constant, the reported seasonal changes in bone mass of normal, adult males appear to result from primary changes in bone formation.

Adult↗
PubMed1984

Bone mass as referent for urinary hydroxyproline excretion: age and sex-related changes in 125 normals and in primary hyperparathyroidism.

Fasting urinary hydroxyproline: creatinine ratio (OHPr:Cr) and bone mineral content of the forearm (BMC) were measured in 125 normals, 67 females and 58 males, aged 20-79 years, and in 15 patients with primary hyperparathyroidism. In normals, both variables were significantly correlated to age and sex. The interrelation of OHPr:Cr and BMC was studied in subgroups of normals who were supposedly in metabolic balance, that is, females aged 20-39 years (n = 24) and males aged 20-49 years (n = 29). In both sexes OHPr:Cr and BMC were positively correlated: r = 0.60 and 0.58, respectively (P less than 0.001). On this basis, BMC correction of all OHPr:Cr values was undertaken now revealing a stable increased level of bone resorption per unit of bone mass in postmenopausal females. In males OHPr:Cr per unit of BMC remained unaltered throughout life. In primary hyperparathyroidism, in which increased bone resorption is inherent, the discriminatory power of OHPr:Cr was significantly improved when calculated per unit of BMC (P less than 0.001). These observations suggest that estimation of bone resorption by use of OHPr:Cr requires adjustment for differences in bone mass.

Adult↗
PubMed1984

Measurements of whole body retention of diphosphonate and other indices of bone metabolism in 125 normals: dependency on age, sex and glomerular filtration.

Measurements of 24-h whole body retention of 99m-Tc-MDP (WBR) has been performed in 125 normal volunteers, together with determinations of serum alkaline phosphatase, urinary hydroxyproline excretion and creatinine clearance. WBR decreased slightly from the 3rd to the 4th decade, after which it increased gradually in the older age-groups. Serum alkaline phosphatase followed an identical pattern, while the urinary hydroxyproline excretion demonstrated a marked but temporary rise in the post-menopausal age-groups. Finally, the creatinine clearance decreased gradually in the older age groups. Analysis of variance demonstrated that WBR varied independently with serum alkaline phosphatase and creatinine clearance, while no relationship between WBR and the hydroxyproline excretion was found. It seems likely that the increasing retention of diphosphonate in elderly persons reflects rising osteoblastic activity as well as decreasing glomerular filtration.

Adult↗
PubMed1984

Testosterone treatment and arginine-induced growth hormone stimulation in male delayed puberty: effects on serum calcium, phosphate and vitamin D metabolites.

Hormonal changes after arginine-induced growth hormone stimulation and subsequent testosterone treatment were examined in 5 patients classified as having male delayed puberty. All the patients responded well to growth hormone stimulation and a significant negative correlation was found between the delay in height age and the maximal growth hormone response, r = 0.80, P less than 0.05. The testosterone treatment did not alter this pattern. Changes in PTH, 25OHD, 24.25(OH)2D, and 1.25(OH)2D were examined at 24 h after the infusion. The results showed significant reductions in PTH (P less than 0.05) and 24.25 (OH)2D (P less than 0.05) and a possible increase in 1.25(OH)2D, whereas 25OHD remained unchanged. These results may support the conception of growth hormone as a common denominator of growth and bone metabolism.

Adolescent↗
PubMed1984

Urinary 99m-Tc-diphosphonate excretion as a simple method to quantify bone metabolism.

Twenty-four-hour whole-body retention (WBR) of 99m-Tc-methylene-diphosphonate (an index of bone turnover) was determined by whole-body counting (WBRs) and complementarily by urine counting (WBRu) in nineteen subjects with normal to highly increased bone turnover. WBRs and WBRu correlated well (r = 0.94, P less than 0.001), and gave almost the same results. Both WBRs correlated equally well with serum alkaline phosphatase and urine hydroxyproline/creatinine (r = 0.82-0.93). Coefficient of variation in WBRu was 7.0%, determined by duplicate measurements in sixteen normals. The injected dose of diphosphonate did not influence WBRu. However, since almost 50% of the diphosphonate excreted in urine appeared during the first few hours after the i.v. injection, the method of WBRu requires careful urine collection. Thus, the simple WBRu determination provides the same information on bone metabolism as does the more cumbersome and expensive WBRs technique.

Adult↗
PubMed1983

Orthostatic response before and after nitroglycerin in metoprolol- and verapamil-treated angina pectoris.

The orthostatic changes in heart rate (HR) and blood pressure (BP) were recorded in ten patients with stable angina pectoris before and after simultaneous sublingual nitroglycerin administration. All patients were examined three times: without other medication, during chronic metoprolol treatment, and during chronic verapamil treatment. Under control conditions, only minor changes were found in systolic BP following vertical tilting, while diastolic BP increased by approximately 10%. Nitroglycerin augmented these changes to some extent, while neither metoprolol nor verapamil caused significant changes. The orthostatic HR increase was considerably augmented by nitroglycerin. Verapamil treatment did not influence this response, while metoprolol caused significant reductions. These findings seem to explain why some few patients have observed severe orthostatic symptoms while taking nitroglycerin during treatment with beta-adrenergic blocking agents.

Aged↗
PubMed1983

Formula diet in the treatment of moderate obesity.

To evaluate the effect of the popular use of formula diets in the treatment of moderate obesity two regimens have been standardized: (1) formula diet replacing three of five daily meals (partial meal replacement (PMR, 1000 kcal (4.19 MJ] and (2) formula diet taken as five pre-meals (pre-meal satiation, PMS greater than or equal to 565 kcal (greater than or equal to 2.37 MJ]. Weight loss and compliance have been evaluated in a prospective 12 weeks randomized clinical trial with allocation to one of the two regimens or to a control group treated with a 1000 kcal (4.19 MJ) conventional diet (CD). CD and PMR were supported by diethylpropion (Dobesin) individually dosaged by the patient. No anorexic drugs was given to the PMS-group. Of 136 consecutively admitted patients 120 were included. After 12 weeks the median weight loss was 7.0, 8.4 and 6.1 kg in the CD-, PMR- and PMS-group, respectively (no significant differences between the groups (P much greater than 0.02]. Thirteen percent dropped out. Consumption of diethylpropion was significantly lower in the PMR-group compared with the CD-group (median 0.15 and 0.60 tablets of 25 mg per d, respectively). Even among selected sub-groups only few subjects obtained a relevant weight loss through continued treatment after the initial 12 weeks. No serious side-effects to the treatments were observed.

Adult↗
PubMed1981

The Copenhagen PRODI project: preliminary results.

A randomized clinical trial concerning treatment of moderate obesity is described. The study compares: (a) conventional 1000 kcal (4.19 MJ) diet with diethylpropion permitted: (b) isocaloric partial meal replacement with protein powder, and diethylpropion permitted; and (c) pre-meal satiation with protein powder. Preliminary results indicate equally good weight losses by the three methods.

Body Weight↗