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Biomedical subjects

H Isler

Publications and source records attributed to H Isler.

At least 55 records · Page 3Linked to original sources
PubMed1984

Salicylate prophylaxis in migraine.

46 migraine patients and 4 patients suffering from "nonmigrainous" vascular headache were treated with 250 mg salicylate daily for 2 months. Platelet aggregability before and under treatment was measured in all patients and in 10 controls. The results confirm platelet hyperaggregability in migraine patients and a reduction of aggregability under salicylate out provide no evidence of any significant clinical improvement, thus falsifying the hypothesis of migraine as a platelet aggregation disorder.

Adolescent↗
PubMed1983

The effects of human myelin basic protein (HMBP) on the bioelectrical activity of the frog spinal cord.

The effects of human myelin basic protein (HMBP) and its individual microheterogeneous components on the electrical activity of the frog spinal cord are compared with those of bovine MBP (BMBP) and glutamate (Glu). HMBP causes a dose-dependent depolarization of the ventral (VR) and dorsal (DR) roots with a reduction of the evoked root potentials. The amplitude of the depolarization induced by 0.01 mM HMBP corresponds to that observed with application of 1 mM Glu. A weaker depolarization persists during blockade of synaptic transmission by MgSO4 or tetrodotoxin, suggesting a direct depolarizing effect on motoneurones and primary afferents. HMBP causes a long-lasting tachyphylaxis. The individual microheterogeneous components of HMBP (peaks 1, 2 and 3), and a mixture of smaller myelin basic proteins elicit similar responses, whereas BMBP and its microheterogeneous components are slightly less active.

Animals↗
PubMed1982

Sites of aldosterone-induced hyperplasia along the nephron and collecting ducts.

Sites of aldosterone-induced hyperplasia along the nephron and collecting ducts. The mitotic activity was separately measured in 12 segments of the nephron and collecting ducts in intact and adrenalectomized rats, injected with aldosterone for two or five days, with daily doses of 0, 10, 20, 40 and 80 micrograms. Stimulation of the mitotic activity was observed in the proximal convoluted tubules, the deep straight distal tubules and in the collecting ducts in the same layer as that containing deep straight tubules (medulla externa interna). Adrenalectomy depressed the mitotic activity in the straight distal tubules and, after 6 days, stimulated it in the proximal convoluted tubules. Adrenalectomy also induced morphological change in these two segments. Apart from the collecting ducts, which have already been recognized as a target for aldosterone, this paper points to another probable target for this hormone: namely the straight distal tubule.

Adrenalectomy↗
PubMed1981

Scanning electron microscopy of the juxtaglomerular apparatus in the freeze-fractured rat kidney.

The morphology of the juxtaglomerular apparatus of the rat kidney was investigated by scanning electron microscopy of the freeze-fractured tissue. The macula densa cells have a dome-shaped apical surface abundantly provided with short microvilli. Their basal and lateral aspects may show labyrinthine spaces which are consistently more developed than in the epithelium across the tubular lumen. The Goormaghtigh cells display the well known complex pattern of cytoplasmic extensions forming the lacis. Fractured juxtaglomerular cells show distinct nuclei and well defined secretory granules. The well developed labyrinth of the macula densa suggest a considerable trans-epithelial fluid transfer at this level.

Animals↗
PubMed1979

[Recurring loss of conciousness with middle brain symptoms in migraine].

A 49-year-old woman subject to frequent migraine attacks since childhood was seen for repeated episodes of confusion followed by loss of consciousness lasting for several hours. EEG during the acute stages showed marked slowing with bifrontal monorhythmic delta waves. After each episode, both the clinical and EEG findings subsided within hours. A similar course is described in a man who died at the age of 69 after preterminal mental deterioration. Autopsy showed evidence of bilateral damage to the hippocampal regions, apparently due to frequent impairment of perfusion in the last years of life. Atherosclerotic changes were within the normal range for his age. In both cases, the ischemic episodes are interpreted as consequences of constriction of the basilar artery, and it is assumed that the underlying mechanism is at least akin to that of migraine.

Aged↗
PubMed1979

Role of the hypophysis in thyroid regeneration after partial thyroidectomy.

The role of the hypophysis in thyroid regeneration was investigated by measuring the mitotic activity of the thyroid remnant in hemithyroidectomized rats as well as the blood levels of thyroid hormone at various time-intervals after hemithyroidectomy. Mitotic activity underwent a significant increase to reach a peak (a 5- to 8- fold increase) 2 days after hemithyroidectomy. The thyroid hormone level in blood was lower than in controls. Histologically, the thyroid gland showed signs of an elevated rate of functional activity, as indicated by losses of colloid and cell hypertrophy. In a second approach, the mitotic activity of the thyroid remnant was estimated in hypophysectomized and in thyroxine treated rats. Both hypophysectomy and thyroxine injection prevented occurrence of the mitotic peak at 2 days. The regeneration of the thyroid after hemithyroidectomy, as it occurred in the present work, may be explained by a release of thyroid stimulating hormone from the pituitary, brought about by the low level of circulating thyroid hormone, itself resulting from a loss of thyroid tissue.

Animals↗
PubMed1976

Adrenal glomerulosa mitotic stimulation by posterior pituitary hormones.

Injection of posterior pituitary powder induces an intense mitotic stimulation in the zona glomerulosa of the adrenal gland of young rats. This effect is much more pronounced in females than in males. It is maximal at two days treatment. Longer periods result in a hypertrophied zona glomerulosa and lower mitotic activity. A search for the hormone responsible for the stimulation shows that vasopressin, and to a lesser extent oxytocin, are mitogenic. ACTH, alpha-MSH, beta-MSH and the pineal hormones have no effect. Renin (but not angiotensin) induces a significant stimulation. It is concluded that vasopressin exerts a potent influence on the glomerulosa. This is in contrast with the prevalent view that the glomerulosa is little affected by the hypophysis.

Adrenal Cortex↗
PubMed1976

Fine structure of chicken thymic epithelial vesicles.

This paper describes the fine structure of epithelial vesicles as observed in the thymus of the chicken. Three types of vesicles are found. The largest is made up of a stratified columnar epithelium containing lymphoid cells. The lumen contains a fairly light material and cell debris. The lumen-bordering cells are columnar and their microvilli are sometimes developed to such an extent as to appear as a brush border. The wall of the vesicles contains lymphocytes and granular cells with dense granules 100-500 nm in diameter. Smaller vesicles are found which contain no lymphoid cells. They are made of a simple or stratified epithelium containing typical mucous cells, and columnar cells similar to the bordering cells of the large vesicles. The third type is an intracytoplasmic vesicle in epithelial reticular cells, which differs from usual vacuoles by the presence of microvilli and its often unusually large size. The morphology of the first 2 types of vesicles indicates a secretory capability, the function of which is unknown. Data from the literature suggest that the third type produces the factor(s) conferring cellular immunological competence.

Animals↗