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Biomedical subjects

J Kalk

Publications and source records attributed to J Kalk.

4 recordsLinked to original sources
PubMed1989

Incidence and causes of hyperthyroidism in blacks.

Between 1974 and 1984 688 black patients with hyperthyroidism were seen at one clinic. Graves' disease made up 88% of cases, with a female: male ratio of 7,9:1. The average annual incidence for females was 8,75/100,000 and for males 0,70/100,000. There appeared to be a progressive increase in incidence (60%) over the period. A bimodal age distribution was observed with peaks at 35-54 years (almost exclusively Graves' disease) and in those older than 64 years (Graves' disease 66%, nodular goitres 34%). Although hyperthyroidism seems rare in rural Africa, 59% of the patients surveyed (N = 88) had been born in such an area and were urban migrants. Moreover, some ethnic groups were disproportionately represented. In one of these (Tswana-speaking), 81% had migrated from rural areas of endemic goitre, usually as adults. It is concluded that hyperthyroidism remains relatively uncommon in the black population in this region. The incidence of Graves' disease, but not of toxic nodular goitre, appears to be increasing rapidly. The process of urbanisation, including possible increases in dietary iodide, may contribute to this apparent increase in Graves' disease in urban areas.

Adolescent↗
PubMed1979

Menstrual disturbances in chronic renal failure.

Twelve female patients undergoing intermittent hemodialysis (HD) and 5 females posttransplantation (PT) were studied. All the HD patients had menstrual disturbances and 5 had galactorrhea. The mean basal LH level was significantly elevated (p less than .05) in patients on HD compared to normal controls, but the mean LH response to luteinizing hormone releasing hormone (LRH) was not significantly different from the control group. Mean basal FSH and the FSH response to LRH was normal. In the PT pateints the LH response to LRH was significantly greater at 120 min when compared to normal females. In the HD group the serum 17B estradiol, progesterone and testosterone levels were significantly lower than in the controls but in the PT group only testosterone levels were significantly lower. These results differ from those previously found in uremic males. Elevated prolactin levels were found in the patients on hemodialysis and correlated well with the presence of galactorrhea. These was no correlation between the elevated prolactin levels and amenorrhea in the patients on hemodialysis but one PT patient with amenorrhea had elevated prolactin levels.

Adolescent↗
PubMed1975

Vascular interdependence in postmortem human lungs.

Interdependence of arteries and the surrounding lung was estimated in excised, postmortem human lungs. At low vascular pressures, vessel diameter increased as the lung was inflated. At high vascular pressures, vessel diameter decreased as the lung was inflated. Compared to the effects of interdependence in excised dog lobes, those in human lungs at low transpulmonary pressures were small. The following conclusions were reached: (1) the diameter of intrapulmonary arteries is stabilized (more constant with changes in intravascular pressure) when the lung has a high transpulmonary pressure; (2) increases in pulmonary vascular resistance at high lung volumes may be related to extra-alveolar, as well as intra-alveolar, vessel compression; (3) interdependence in human lungs differs markedly from interdependence in dog lungs.

Adolescent↗