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Biomedical subjects

H Schmidt-Gayk

Publications and source records attributed to H Schmidt-Gayk.

At least 163 records · Page 9Linked to original sources
PubMed1978

Skeletal X-ray findings and bone histology in patients on hemodialysis.

X-ray films of the hand skeleton (mammography technique), serum chemistry, and quantitative bone histology (micromorphometry of undecalcified sections, iliac crest spongiosa) were compared in 25 patients on maintenance hemodialysis. The X-ray findings correlated better with serum PTH levels than with bone histology. Of all radiological signs of renal osteodystrophy, pronounced subperiosteal resorption (radial aspect, second finger, middle phalanx) and periosteal new bone formation (middle phalanx) correlated best with histological indicators of osteitis fibrosa. These signs were never seen in control patients. Acroosteolysis (endphalanx) and intracortical or endosteal resorption (middle phalanx) were less specific (i.e., seen even in the absence of metabolic bone disease) and correlated less with bone histology. Osteosclerosis in iliac cancellous bone was paralleled by abnormal texture of spongy bone in the proximal metaphysis of the middle phalanx (second finger).

Adult↗
PubMed1978

Radioimmunoassay for parathyrin. Characterization of six different antigens and antisera.

We studied six different antisera to bovine or porcine parathyrin (parathyroid hormone, PTH), produced in rabbit, guinea pigs, sheep or goat, two of which are commercially available. The antisera were characterized with regard to species specificity, affinity and their ability to identify patients with primary hyperparathyroidism. In this heterologous radioimmunoassay system in which [125I]parathyrin is used as a tracer, some cross-reactivity of the antisera to the hormone or hormone fragments present in human serum was demonstrated. However, there is some overlap of serum immunoreactive parathyrin in patients with or without primary hyperparathyroidism. The results of this and other studies illustrate the necessity for a homologous radioimmunoassay for human parathyrin.

Animals↗
PubMed1978

Does long term haemofiltration provoke secondary hyperparathyroidism?

One thousand nine hundred and forty-nine haemofiltration procedures have been performed since 1976; 4 different types of haemofilters have been tested in gravimetric and volumetric haemofiltration machines. Balance studies revealed a diminished calcium intake of about 1/3 of that found in conventional dialysis. Magnesium balance is negative and leads to decreasing serum Mg values. Inorganic phosphate is removed in similar quantity to dialysis. PTH levels increase during 3--18 months of treatment, whereas 25-OH-D3 levels rapidly fell, gc-globulin- and HCT-levels did not change markedly. g-c globulin could be detected in filtrate samples in remarkable amounts, 25-OH-D3 was found in traces. Radiologically no apparent alteration occurred. We recommend Vitamin D supplementation to compensate for the losses and thereby avoid development of secondary hyperparathyroidism.

Calcium↗
PubMed1977

[Diagnosis of anticonvulsant osteomalacia in adults (author's transl)].

In 100 epileptic patients under treatment with long-term anti-convulsants, radiographs of the hands and feet, and estimations of serum 25-hydroxycholecalciferol, parathormone, alkaline phosphatase, calcium, and inorganic phosphate were done to detect a medication-induced osteomalacia. The correlation between the individual parameters was investigated. It was shown that the serum 25-hydroxycholecalciferol level and the skeletal radiograph were the most valuable in the early detection of osteomalacia. One of these investigations in addition to routine serum chemistry is recommended for the future at the yearly follow-up examinations of adult epileptics so that early and adequate treatment with vitamin D can be started.

Adolescent↗
PubMed1977

[Paralysis in hypophosphataemia (author's transl)].

Neuromuscular syndromes and respiratory insufficiency may be caused by hypophosphataemia. This complication may occur particularly in patients with malnutrition who receive parenteral glucose, as two examples show.

Adult↗
PubMed1977

25-hydroxy-vitamin-D in nephrotic syndrome.

Serum-25-hydroxy-vitamin-D (25-OHD) nephrotic syndrome (N.S.) without renal insufficiency (urinary protein excretion greater than 3-5 g/24 h/1-73 m2; glomerular filtration-rate greater than 80 ml/min/1-73 m2). Serum-25-OHD levels were low in patients with N.S. (mean 19 nmol/1, range 4-41 nmol/1), compared with a normal range of 25-200 nmol/1. Serum-concentrations of Gc-globulin--the binding protein for vitamin D and its metabolites (D.B.P.)--were significantly (P less than 0-001) lower in patients with N.S. (mean 340 mg/1, range 190-480 mg/1) than in non-proteinuric controls (mean 440 mg/1, range 376-510 mg/1, measured by radial immunodiffusion). In contrast to non-proteinuric urine, urine of all N.S. patients contained a large amount of 25-OHD-binding capacity; D.B.P. could be detected in all N.S. urines after concentration. Scatchard analysis of the urine demonstrated the presence of a low-affinity and a high-affinity binding protein (tentatively identified as albumin and D.B.P.). These results suggest an acquired deficiency of circulating 25-OHD in N.S. secondary to urinary loss of protein-bound 25-OHD. The biological relevance of the low 25-OHD levels is unknown. There was no clinical evidence of osteomalacia (X-ray, serum-alkaline-phosphatase); however, slightly elevated serum-parathyroid-hormone (P.T.H.) levels would be compatible with borderline vitamin-D depletion.

Adolescent↗
PubMed1977

Vascular calcifications under maintenance hemodialysis.

In a cross-sectional study X-rays of the forefoot and the pelvis of 101 adult dialysis patients were taken. Vascular calcifications (forefoot) were observed in 20 patients. The incidence was higher in patients who had been started on dialysis several years ago. However, in a longitudinal prospective study de novo appearance of vascular calcificaitons was observed only in 1 out of 50 dialysed patients, although hyperparathyreoidism and moderate hyperphosphatemia persisted. Vascular calcifications were seen only once in 138 uremic children (56 uremic children without dialysis; 82 uremic children on maintenance hemodialysis). However at autopsy visceral calcifications of the lung were found in three (out of 11) children who did not have vascular calcificaitons on X-rays.

Adolescent↗
PubMed1977

Hyperparathyoidism: influence of glomerular filtration rate on urinary excretion of cyclic AMP.

Urinary cyclic AMP excretion per 24 h or per g creatinine in primary hyperparathyroidism (1 degrees HPT) has been evaluated by several authors with conflicting results. In 50 patients with 1 degrees HPT, 25 patients with secondary (2 degrees) HPT and 35 healthy control persons we determined urinary cyclic AMP per 24 h or per g creatinine. These parameters did not satisfactorily discriminate patients from controls, especially when glomerular filtration rate (GFR) as determined by creatinine clearance was reduced. Since urinary cyclic AMP is derived from plasma by glomerular filtration and from kidney by tubular production-the amount of tubules is reflected by GFR-the cyclic nucleotide was related to GFR. In controls urinary cyclic AMP correlated better with GFR than with creatinine excretion. Additionally, in 45 of 50 patients with 1 degrees HPT and in all with 2 degrees HPT, urinary cyclic AMP/GFR was raised. In 1 degrees HPT serum levels of parathyroid hormone correlated closer with urinary cyclic AMP/GFR than with urinary cyclic AMP/g creatinine. The ratio cyclic AMP/GFR decreased to normal or subnormal values after removal of adenomatous or hyperplastic glands in 1 degrees HPT and during infusion of calcium in 2 degrees HPT. In 50 patients with renal lithiasis caused by diseases other than 1 degrees HPT (anatomical variations, pyelonephritis, immobilization after tetraplegia) the ratio cyclic AMP/GFR was not raised. Urinary cyclic AMP/GFR, therefore, reflects parathyroid hormone excess more reliably than cyclic AMP/g creatinine.

Adolescent↗
PubMed1977

Serum 25-hydroxycalciferol in myocardial infarction.

Oral intake of calciferol (vitamin D) was higher in patients with myocardial infarction than in controls. Having established an assay for 25-hydroxycalciferol (25-OH-D), the principal circulating form of the vitamin, we measured this compound in control subjects and patients with myocardial infarction. In controls, 25-OH-D varied with the season: levels were high in summer and low in winter. Furthermore, levels were low in control subjects above 60 years of age. In patients with myocardial infarction, normal and low values for 25-OH-D were found. It is concluded that in this region patients with myocardial infarction do not consume greater amounts of vitamin D.

Adolescent↗
PubMed1977

[Handskeleton studies with mammography technique in patients under antiepileptic medication (author's transl)].

An investigation with 114 epileptic patients under continuous treatment with anticonvulsiva was conducted in order to determine to what extent studies of the handskeleton with low-KV-technique will contribute to diagnosing osteopathy. The roentgenological findings of the hand were correlated with the x-ray findings of the remainder of the skeleton and with the results of biochemical studies. A control biopsy was performed in 8 cases. Definite and with all methods recognizable signs of osteomalacia were present in 7% of the cases, although only 2 patients developed a pathologic fracture. Another 32 patients (28%) showed suspicious changes in the handskeleton, which could not be confirmed by the comparative studies. No patient with normal findings of the handskeleton showed suspicious changes in the remainder of the skeleton or clinical and chemical indications of osteomalacia.

Adolescent↗
PubMed1977

Skeletal changes and growth in experimental uremia.

Longitudinal growth; bone and growth zone histology; growth cartilage and bone mineralization (tetracycline technique); bone Ca content (neutron activation analysis); bone radiology; serum and urine chemistry; urinary cAMP and serum 25-OH-vitamin D3 were studied in a long-term model of experimental uremia in the rat. Uremia was induced by two-stage subtotal nephrectomy with irradiation of the remaining parenchyma. Ccr in the experimental group was 113 +/- 5.8 micron1/min X 100 g (19.8% of controls) and serum creatinine 1.67 +/- 0.04 mg% (5.1 X control value). Uremic animals were pair-fed with sham-operated controls. In the proximal tibia delayed transformation of cartilage into primary spongiosa with appearance of chondro-osteoid and delayed transformation of primary spongiosa into secondary spongiosa was observed (rickets). Increased amounts of osteoid were present although 25-OH-vitamin D3-levels were high. There were only modest signs of secondary hyperparathyroidism (osteoclast counts; urinary cAMP). In spite of the presence of bone disease, longitudinal growth was not reduced in uremic animals as compared with pair-fed sham-operated animals, but was significantly reduced as compared with ad lib fed control animals. In contrast, weight gain was significantly diminished in uremic animals as compared with pair-fed sham-operated control animals. It is concluded that diminished intake of food is the major determinant of growth retardation in preterminal experimental renal failure.

Alkaline Phosphatase↗