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Biomedical subjects

W Penn

Publications and source records attributed to W Penn.

18 recordsLinked to original sources
PubMed1979

The role of vasopressin in blood pressure regulation immediately following acute haemorrhage in the rat.

1. The possible pressor effect of vasopressin immediately after acute haemorrhage has been studied using anaesthetized Brattleboro rats with diabetes insipidus and rats of the Long Evans parent strain.2. A blood loss of 0.5% of the body weight caused a significant decrease in mean arterial blood pressure, measured 10 min later, in Brattleboro rats, whereas this degree of haemorrhage was non-hypotensive in the control Long Evans rats. Following subsequent blood losses (each of 0.5% of the body weight), mean arterial blood pressure in Brattleboro rats was always significantly lower than in Long Evans rats.3. While no antidiuretic activity was at any time found in the plasma of Brattleboro rats, haemorrhages greater than 1% of the body weight were associated with marked increases in plasma arginine vasopressin (AVP) of Long Evans rats.4. When Brattleboro and Long Evans rats were subjected to a single haemorrhage of 2% of the body weight, the immediate decrease in arterial blood pressure was similar in the two groups. However, 5 and 10 min after the haemorrhage the arterial blood pressure was significantly higher in the Long Evans rats. When vasopressin was infused into Brattleboro rats so that plasma levels of the hormone approached those found in Long Evans rats, the mean arterial blood pressure 0, 5 and 10 min after haemorrhage was similar to that in the Long Evans animals.5. It is concluded that in the anaesthetized rat, vasopressin plays an important role in the regulation of arterial blood pressure during the period immediately following acute haemorrhage.

Animals↗
PubMed1977

[Renovascular hypertension in neurofibromatosis. Simultaneous occurrence of multiple abdominal and cerebral vascular abnormalities (author's transl)].

Vascular involvement in von Recklinghausen's neurofibromatosis has been known since the work of Reubi (1944, 1946). We found 72 cases of neurofibromatosis with renovascular hypertension reported in the literature. We have observed three female patients, of whom two had unilateral renal artery abnormalities consisting of stensoses and small aneurysms. The third patient, who had a right-sided nephrectomy for probable occlusion of the renal artery, had a coarctation of the abdominal aorta and complete occlusion of the left renal artery and of the coeliac-mesenteric trunk. There were, in addition, large, bilateral aneurysms in the circle of Willis.

Adult↗
PubMed1977

[Intrarenal localisation of renorenal collaterals in the dog. Observations on renal arteries as end-arteries (author's transl)].

One of the two main branches of the left renal artery was slowly occluded in four dogs. Repeated angiography was carried out from 45 to 61 days postoperatively; this made it possible to observe the development of collaterals between the normal and constricted branches of the renal artery, i.e. intrarenal renorenal collaterals. These collaterals developed predominantly from preexisting vessels of the extraglomerular system in the vicinity of the renal pelvis and calyces and, to a lesser extent, from medullary vessels and from forating capsular arteries.

Animals↗
PubMed1976

Female gonadal exposure dose in routine diagnostic radiology.

Measurements of gonad doses received by female patients during routine roentgenology are presented. LiF dosemeters were used to measure the exposure doses in the vagina. With the aid of phantom studies, the ovary doses were calculated from the doses determined in patients. Their relationships to skin doses are shown. The results are tabulated. A comparison with results by other authors is given.

Dose-Response Relationship, Radiation↗
PubMed1975

[Reno-coeliac steal phenomenon: the inferior phrenic and supra-renal arteries as collaterals for the coeliac trunk (author's transl)].

If the known collateral pathways for a stenosed or occluded coeliac trunk are not avialable whether for anatomical of haemodynamic reasons, a collateral circulation can be established through the suprarenal and inferior phrenic arteries to provide a significant flow. This is particularly so if the inferior phrenic artery arises from the coeliac trunk distal to the point of occlusion. The development of a reno-coeliac steal phenomenon or steal syndrome may then be expected, particularly if the main donor artery is a suprarenal branch arising from the renal artery.

Adrenal Glands↗
PubMed1974

Basis of nocturnal polyuria in patients with autonomic failure.

Five dysautonomic patients with the Shy-Drager syndrome were studied to determine the basis of their nocturnal polyuria. The results indicated excessive postural modification of renal function in dysautonomic patients. This may, in fact, relate to excessive release of ADH while these patients are up and about, and excessive inhibition while they are recumbent. Treatment with vasopressin produced an inconsistent response.

Aged↗