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Biomedical subjects

M Petri

Publications and source records attributed to M Petri.

At least 199 records · Page 11Linked to original sources
PubMed1977

Surface staining of small intestinal biopsies.

Small intestinal biopsies are most often by routine examined under a stereo-microscope, prior to embedding for histological examination. This is done in order to get a view of the appearance of the mucosal pattern, especially villus configuration. The distinctness of the surface pattern however, is improved considerably if the biopsies are stained with Alcian Green and/or PAS before they are examined. In the present paper a detailed description is given of staining of small intestinal biopsies as whole mounts. The difference between the unstained and the stained biopsies is illustrated by a few examples.

Biopsy↗
PubMed1976

Is vasopressin involved in the pathogenesis of malignant desoxycorticosterone hypertension in rats?

Rats with unilateral nephrectomy were offered 1% sodium chloride as drinking fluid and were injected with desoxycorticosterone trimethylacetate (D.O.C.-T.M.A.) at weekly intervals. During the fourth to seventh week after the start of the experiment, malignant hypertension developed in most of the animals: body weight fell, reflecting volume depletion; serum osmolality and serum sodium and urea concentrations increased; in the kidneys malignant nephrosclerosis occurred. In such animals, plasma concentrations of arginine-vasopressin were increased ten-fold in comparison with control animals; intravenous injection of a specific vasopressin antibody resulted in a transient fall of blood-pressure (B.P.) to normal or subnormal levels, while the injection of an angiotensin-I or angiotensin-II antibody did not affect B.P. In control animals none of the antibodies had an effect on B.P. It is concluded that in the pathogenesis of malignant D.O.C. hypertension vasopressin plays a role similar to that of renin-angiotensin in malignant renal hypertension.

Angiotensin II↗
PubMed1976

Vasopressin and malignant deoxycorticosterone hypertension in rats.

1. The role of arginine-vasopressin in the pathogenesis of malignant deoxycorticosterone (DOC) hypertension of rats was investigated. 2. In rats with malignant DOC hypertension plasma arginine-vasopressin concentrations increased more than tenfold subsequent to volume depletion and a rise of serum osmolality. 3. The injection of a specific antibody serum for arginine-vasopressin caused a marked fall of blood pressure in rats with malignant DOC hypertension, whereas the injection of angiotensin II antiserum did not affect blood pressure. 4. In rats exhibiting a benign course of DOC hypertension plasma concentrations of arginine-vasopressin were increased threefold in comparison with normotensive control rats; the injection of an arginine-vasopressin antiserum induced a significant but small fall of blood pressure. 5. It is concluded that in the pathogenesis of malignant DOC hypertension arginine-vasopressin might play the role that the renin-angiotensin system plays in the pathogenesis of malignant renal hypertension.

Animals↗
PubMed1976

Effects of saline drinking on malignant course of renal hypertension in rats.

In rats with unilateral renal artery stenosis and an intact contralateral kidney, a malignant course of hypertension (MH) may develop, which is characterized by 1) high BP levels, 2) sodium and water loss and a polyuric-polydipsic syndrome, 3) marked activation of the renin-angiotensin system, 4) malignant nephrosclerosis in the contralateral kidney and high plasma urea concentrations, and 5) deterioration of the animals' general condition. (Some rats exhibit signs of a cerebral vascular crisis; some rats die). When such rats are offered in addition to water 0.9% NaCl, they compulsively drink the saline, BP falls for some days to levels found in the other hypertensive animals, and signs of MH nearly or completely disappear. It is concluded that high saline intake has, for a limited period, a beneficial effect on the malignant course of renal hypertension in rats. The observations made are consistent with the hypothesis that salt and water loss, which ensue subsequent to an increase of BP into a critical high range might trigger the onset of malignant hypertension.

Angiotensin II↗
PubMed1976

Jejunal morphology and mucosal enzyme activity following intestinal shunt operation for obesity.

Jejunal biopsy in 33 patients before and after intestinal shunt operation for obesity has demonstrated that neither surface nor volume of the villi increase after surgery. Specific disaccharidase activity remained unchanged, and specific alkaline phosphatase activity increased slightly. There was a significant decrease in protein content in the postoperative biopsies. It is concluded that weight stabilization after the shunt operation is due to adaptive compensation in the ileal remnant.

Adolescent↗
PubMed1975

Salt appetite during the early phase of renal hypertension in rats.

In male Sprague-Dawley rats the left renal artery was constricted by a 0.2mm silver clip while the contralateral kidney was left untouched. 10 days after clipping the animals were offered, in addition to water, 0.9% saline as drinking fluid for 6 days. Hypertensive animals drank twice as much saline as did control rats throughout the period of observation. In the hypertensive animals, 24-hrs saline intake during the first day of the self-selection study was quantitatively related to the actual height of blood pressure and to the preceding blood pressure increase. After 6 days on the self-selection regimen, plasma angiotensin II concentrations in the hypertensive rats were elevated by 50% when compared with control rats. On the basis of these and previously reported findings (i.e. an increased activity of the renin-angiotensin-aldosterone system and sodium retention) it is suggested: a) despite sodium retention salt appetite is enhanced, indicating a disordered regulation of sodium balance during the early phase of renal hypertension in rats; b) elevated plasma concentrations of angiotensin II and aldosterone could have enhanced salt appetite; c) despite greater salt intake than in control rats the activity of the renin-angiotensin system remains elevated in renal hypertensive rats, thereby possibly inducing a sustained high saline intake.

Aldosterone↗
PubMed1975

Liver morphology and liver function before and after intestinal shunt operation for obesity.

Liver biopsy and liver function tests were performed in 17 obese patients before and 14 months after intestinal shunt operation for obesity. In another 20 patients liver biopsy was performed postoperative only, in 12 patients preoperatively only. Steatosis was present in 85 per cent. of the patients before the operation. After the operation steatosis decreased in half the patients and increased in the other half. In patients with biopsy twice postoperatively there was a significant trend of decreasing steatosis up to 56 months after the operation. No patient developed cirrhosis during the time of observation. Within the first postoperative year there was a substantial and significant increase in serum alanine-aminotransferase and a minor increase in alkaline phosphatases and BSP. There was no correlation between the rate of weight loss and the change in steatosis or liver function.

Adolescent↗