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Biomedical subjects

K Kruse

Publications and source records attributed to K Kruse.

At least 19 recordsLinked to original sources

Calcium metabolism in Williams-Beuren syndrome.

Increased 1,25-dihydroxyvitamin D levels and decreased basal and calcium-stimulated calcitonin serum levels have been found in children with Williams-Beuren syndrome (WBS). To determine whether isolated or combined disturbances of secretion or action of the calcium-regulating hormones may cause the tendency to hypercalcemia in WBS, we investigated several aspects of calcium metabolism in 27 normocalcemic children and adults, aged 2 to 47 years, with WBS. With the exception of slightly decreased 25-hydroxyvitamin D and slightly increased calcitonin in serum, all measured basal indexes of calcium and bone metabolism, including the serum levels of intact parathyroid hormone and 1,25-dihydroxyvitamin D, were comparable to control values. Total and extractable calcitonin, the latter representing the monomeric and biologically important form of the hormone, showed the same relative increase after a low-dose calcium infusion in patients and control subjects, indicating a normal capacity of the calcitonin-producing C cells of the thyroid gland in WBS. Furthermore, exogenous parathyroid hormone induced a normal response of 1,25-dihydroxyvitamin D, cyclic adenosine monophosphate, and phosphate excretion, indicating a normal response of the renal 25-hydroxyvitamin D-1 alpha-hydroxylase and the renal receptor-adenylate cyclase system to parathyroid hormone. These findings suggest that neither deficient calcitonin secretion nor increased renal sensitivity to parathyroid hormone is a feature of WBS in normocalcemic patients.

Adolescent

Assessing health care delivery to male versus female veterans.

The study reported was undertaken to explore allegations that women veterans have not received the quality of care in the Department of Veterans Affairs (VA) that is typical of that being received by their male counterparts. The study consisted of a chart review of male and female inpatients (n = 114) and telephone interviews with a subsample of these veterans (n = 55) treated at a large metropolitan VA hospital. Overall, chart documentation was poor, regardless of gender. On average, two-thirds of males and females receive regular gender-specific examinations, although the number is somewhat lower for females. Both women and men were quite satisfied with the care they received. Future studies should focus on the evaluation of workable solutions to providing equitable health care to women veterans that are already in operation.

Female

[Perinatal calcium metabolism. Physiology and pathophysiology].

During pregnancy, calcium is continuously transferred directly from the maternal intestine to the fetal bone, a transfer that is mainly induced by the interrelated actions of the calcium-regulating hormones parathyroid hormone (PTH), 1,25-dihydroxyvitamin D (1,25(OH)2D) and calcitonin. It has recently been demonstrated in animals that PTH-related protein (PTHrP) is the fetal equivalent of PTH. Human PTHrP, originally described as a product of a human lung cancer cell line and implicated in the pathogenesis of humoral hypercalcemia of malignancy, is a protein with 141 amino acids, and it has biochemical actions similar to PTH. It is believed that fetal PTHrP is mainly derived from the placenta during early gestation and from the fetal parathyroid glands during further development and that this protein has the role of maintaining the maternal-fetal calcium gradient either alone or in concert with 1,25(OH)2D. With birth, the placental supply of calcium ceases abruptly, stimulating the increase of PTH and 1,25(OH)2D, which are the main regulators of postnatal calcium metabolism. Alterations in the placental calcium (and phosphate) gradient may be caused by maternal hypo- or hypercalcemia and placental insufficiency and may be followed by transient disorders of calcium metabolism in the newborn. Due to abrupt cessation of the calcium and phosphate supply after delivery at a time when mineral demands are the highest, preterm infants are especially prone to hypocalcemia and osteopathy. If bone disease of prematurity is to be prevented, the amounts of calcium and phosphate must be adequate, as demonstrated by laboratory tests, the most important being calcium and phosphate in urine and alkaline phosphatase activity in serum.

Animals

Vitamin D dependent rickets type II with myelofibrosis and immune dysfunction.

We present a new patient with vitamin D dependent rickets type II. A 20-month-old Arabian boy whose parents are first cousins showed florid rickets, myelofibrosis and recurrent septicaemia. In addition to absent specific binding for 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). 25-Hydroxyvitamin D3-24-hydroxylase activity could not be induced in cultured fibroblasts. The patient did not respond to 99 micrograms 1,25(OH)2D3 per day, but skeletal and haematological abnormalities improved with daily infusion of 100 mg/kg calcium, as serum parathyroid hormone levels fell to normal values. At the age of 7 years, he died from pneumonia. The improvement of haematological abnormalities with calcium infusions but not with 1.25(OH)2D3 suggests a pathogenetic relationship of myelofibrosis and hyperparathyroidism. Having anti-lipid A IgM antibody titres up to 1:10.000 after Gram negative septicaemias, the patient never produced corresponding IgG antibodies. His neutrophil chemotaxis was persistently reduced to 57% +/- 3% of age-matched controls (P less than 0.028). The patient showed two pathological immune functions considered to contribute to the well-known susceptibility to infection in rickets.

Calcium

Effect of calcitonin deficiency on bone density and bone turnover in totally thyroidectomized patients.

To investigate the influence of calcitonin deficiency on bone turnover and density we studied 25 premenopausal female and 12 male patients (age 23 to 49 years) who had undergone total thyroidectomy for differentiated thyroid cancer 1 to 15 years previously. Basal and calcium stimulated extractable calcitonin, representing the monomeric, biologically active form of the hormone, was lacking or markedly decreased in all patients. There was a relative increase of urine hydroxyproline excretion (an index of osteoclastic bone degradation) in relation to serum osteocalcin (an index of osteoblastic bone formation) indicating an imbalance of bone turnover with a tendency to increased degradation in all patients. Total and trabecular bone density, measured with quantitative computed tomography at the distal forearm were significantly decreased in the male and normal in the female patients, without a relation to the duration of the calcitonin deficiency. The study indicates that patients with calcitonin deficiency, suppressive thyroid hormone treatment, or both may have a higher risk of increased bone degradation and osteopenia. Whether the effect is more due to calcitonin deficiency or thyroid hormone therapy, cannot be concluded from this study design. The fact that only the male patients had a decreased bone density may be due to a lower parathyroid activity in our female patients and the greater thyroidectomy-induced decrement of monomeric calcitonin in our male patients compared with male controls.

Adult

Is a skull X-ray necessary after milder head trauma?

During the 2-year period 1985-86 a total of 1,876 patients were admitted to our hospital after milder head trauma including cerebral concussion. Two hundred and eighty four patients who had a skull X-ray were not selected from guidelines. In 1,592 patients without a skull X-ray, signs of an intracranial complication developed in six cases and were verified by CT. In the 284 patients with skull X-ray a fracture was demonstrated in 25, and of these 25 patients only one patient disclosed a cerebral contusion. In the 259 patients with skull X-ray, but without demonstration of fracture, there were subsequently seen one subdural haematoma and one cerebral contusion. The incidence of intracranial complications in patients without and with skull X-ray with or without fracture does not differ significantly. In these circumstances we do not find any justification for routine skull X-ray after milder head trauma.

Brain Concussion

Nephrogenic diabetes insipidus and intracerebral calcification.

Three children who presented with two rare conditions, nephrogenic diabetes insipidus and intracerebral calcification, were studied. The lack of evidence for the presence of a metabolic defect other than nephrogenic diabetes insipidus suggests that it can lead to the development of intracerebral calcification. Perhaps the main risk factor is inadequate fluid intake during early infancy.

Brain

Biochemical markers of bone turnover, intact serum parathyroid horn and renal calcium excretion in patients with pseudohypoparathyroidism and hypoparathyroidism before and during vitamin D treatment.

In addition to the well-documented hyporesponsiveness of the kidney, resistance to parathyroid hormone (PTH) has been postulated for bone in pseudohypoparathyroidism type I (PHP). In some of these patients reduced bone density and even frank osteitis fibrosa suggest osteoclastic overactivity. To address the possibility that the skeletal system of patients with PHP may be affected by their increased PTH secretion we measured intact serum PTH and three biochemical markers of bone turnover in a large number of patients with PHP (n = 20). The results were compared with subjects with low (hypoparathyroidism, HP n = 29), normal (controls, n = 31) and high (primary hyperparathyroidism, 1 degree HPT, n = 13) PTH secretion. Both markers of osteoblastic bone formation, alkaline phosphatase activity and osteocalcin concentration in serum, and one index of osteoclastic bone degradation, the urinary hydroxyproline/creatinine ratio (OH-P/Cr), were decreased in HP and increased in 1 degree HPT, whereas only OH-P/Cr was elevated in patients with PHP. Although intact serum PTH was significantly more increased in PHP than in 1 degree HPT, the markers of bone turnover were not significantly different in these two groups, suggesting some bone resistance in the patients with PHP. In these subjects intact serum PTH was elevated even at normocalcaemia during vitamin D treatment with a negative correlation with the respective serum calcium concentration (r = -0.69, P less than 0.001), indicating an elevated set-point for the suppression of their parathyroid glands. OH-P/Cr was negatively related to serum calcium in PHP, it normalized in most patients during normocalcaemia induced by vitamin D treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

DNA analysis in juvenile Huntington disease.

We report a 6-year-old boy with a positive family history of Huntington disease (HD), who presented with ambiguous neurological and psychiatric symptoms. The suspected diagnosis of HD was confirmed by DNA analysis. This new method is very helpful when the first signs of HD cannot be clearly interpreted.

Child

Endocrine responses to growth hormone-releasing hormone, thyrotropin-releasing hormone and corticotropin-releasing hormone in depression.

To explore and to compare hypothalamic-pituitary-somatotropic (HPS), hypothalamic-pituitary-thyroid (HPT) and hypothalamic-pituitary-adrenocortical (HPA) axis function in depression, 30 subjects (15 patients with a major depressive episode and individually matched controls) received 50 micrograms growth hormone-releasing hormone-44 amide at 9:00, 200 micrograms thyrotropin-releasing hormone (TRH) at 9:00 and 100 micrograms human corticotropin-releasing hormone (CRH) at 18:00 on consecutive days as an i.v. bolus dose. Compared with controls, depressed patients showed blunted growth hormone (GH) responses to GHRH, decreased TRH-induced thyrotropin (TSH) release and reduced corticotropin (ACTH) but normal cortisol secretion following CRH. ACTH secretion following CRH and TRH-induced TSH release were positively correlated across depressed patients and controls but no significant correlations between GH responses to GHRH and TRH-induced TSH release or ACTH and cortisol secretion following CRH administration were demonstrated. Our findings suggest that altered HPT and HPA axis function associated with depression are triggered by factors that are at least partly different from those that cause HPS system dysfunction. We conclude that the pathophysiological process resulting in aberrant neuroendocrine secretory dynamics associated with depression may primarily occur at a suprapituitary site, and that HPS, HPT and HPA axis dysfunction may be precipitated by complex central and peripheral regulatory mechanisms involving largely independent factors.

Adrenocorticotropic Hormone

Spondyloenchondrodysplasia.

Spondyloenchondrodysplasia is a rare autosomal recessive skeletal dysplasia with vertebral dysplasia and enchondroma-like lesions in the pelvis and long bones. The vertebral bodies show dorsally accentuated platyspondyly with disturbance of ossification. Clinical abnormalities such as short stature, rhizomelic micromelia, increased lumbar lordosis, barrel chest, facial anomalies, and clumsy movements may be present. We report on four patients, three of them from one family, who showed a wide range of clinical and radiological changes to document considerable variability of expression of the mutated gene.

Abnormalities, Multiple

[The effect of maternal dexamethasone treatment after the 12th week of pregnancy on fetal genital development in adrenogenital syndrome with 21-hydroxylase deficiency].

Prenatal treatment with dexamethasone starting with gestation week 5 has been proposed to prevent virilization of female fetuses with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. We report dexamethasone treatment in a mother during her third pregnancy; this treatment could not be started before the 12th week of gestation. The second child (index case) had a simple virilizing 21-hydroxylase deficiency CAH and Prader IV genitalia. Because after amniocentesis a normal female karyotype and HLA identity with the index case were found, the dexamethasone treatment (3 x 0.5 mg/die) was continued until delivery.-In contrast to patients with salt-wasting CAH, the 17-alpha-hydroxyprogesterone level in the amniotic fluid was within the normal range. Decreased maternal plasma and urine estriol concentrations, as well as the plasma cortisol values, demonstrated adequate suppression of the fetal and maternal adrenal gland. No side effects were found in the mother as a result of the dexamethasone treatment. The newborn had virilization of the external genitalia according to Prader III but without hypertrophy of the clitoris. The degree of rugated scrotum was less marked in relation to the index case and the sinus urogenitalis was more distally shifted. Thus, surgery on the clitoris could be avoided. The conditions for further surgery (vaginoplasty) could probably be improved. Therefore, dexamethasone treatment of a mother with a female CAH fetus due to 21-hydroxylase deficiency seems to be justified starting at the 12th week of gestation. However, the optimal beginning of therapy is in early pregnancy.

Adrenal Hyperplasia, Congenital