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Biomedical subjects

G Kelly

Publications and source records attributed to G Kelly.

At least 127 records · Page 7Linked to original sources

Naloxone attenuates the hypotension induced by Hageman factor.

The hypotension induced in the pentobarbital anesthesized rat by the i.v. administration of an active Hageman factor fragment (Hff) is significantly attenuated by naloxone. This effect is specific because the opiate antagonist does not modify the hypotension elicited by rat urinary kallikrein, bradykinin or nitroglycerin. These results suggest that the contact activation of endogenous Hageman factor could result in the generation of vasoactive opioid peptides derived from circulating large molecular weight precursors.

Animals↗

Papilledema in two patients with acromegaly and intrasellar pituitary tumors.

Two patients had bilateral papilledema complicating acromegaly. Both patients had enlarged blind spots, but otherwise visual fields were normal. Suprasellar extension of the pituitary tumors was diligently sought with the use of visual field examination, pneumoencephalography, internal carotid arteriography, and computed axial tomography, and tumor extension did not exist. Transphenoidal and transethmoidal routes were used to perform partial hypophysectomies in these patients. The procedure was completely successful in one patient and partially successful in the other patient. After hypophysectomy, papilledema resolved in both patients. This beneficial effect may be the result of anatomical changes, the reduction in growth hormone levels, or both. These observations suggest that the acromegaly may be different from papilledema that occurs secondary to suprasellar expansion of pituitary tumors.

Acromegaly↗

Effect of prostacyclin (PGI2) on renal function and renin secretion in hypophysectomized dogs.

The effect of PGI2, the principal metabolite of arachidonic acid in mammalian arterial and venous tissues, on renal function and renin secretion was investigated in anesthetized, hypophysectomized dogs undergoing a maximal water diuresis. PGI2 in a concentration of 0.04 microgram/kg/min significantly increased urine flow and urinary sodium and potassium excretion in the absence of changes in glomerular filtration rate or blood pressure. The fact that PCI2 significantly increased free water clearance and distal delivery of sodium and inhibited distal fractional rea0sorption of glomerular filtrate is suggestive of an effect on proximal as well as distal sites of the nephron. PGI2 increased renin secretion rates threefold. This promotion of renin release may have been caused by an increase of ion flux across the macula densa or by an increase in renal blood flow. On a molar basis, PGI2 is about 10 times more potent than PGE2 with regard to natriuresis, diuresis and renin release when studied under identical conditions. Thus, PCI2 may be the major prostaglandin involved in the regulation of salt and water excretion.

Animals↗

Effect of indomethacin on renal function and plasma renin activity in dogs with chronic renovascular hypertension.

The effect of indomethacin on plasma renin activity (PRA) and renal function was examined in conscious dogs with chronic renovascular hypertension before or after volume expansion. PRA did not change following the infusion of indomethacin: PRA was 5.18 +/- 1.46 ng/ml/h during control periods and was 5.01 +/- 0.95 ng/ml/h (p greater than 0.1) after 80 min of infusion of indomethacin. Mean arterial blood pressure (MABP) was 121.6 +/- 7.4 mm Hg during control periods and was 122.0 +/- 4.6 mm Hg (p greater than 0.1) after 80 min of infusion of indomethacin. Infusion of indomethacin into these dogs undergoing diuresis did not change inulin or p-aminohippuric acid clearance. Sodium excretion (UNaV) showed slight but not signifcant decreases with the infusion of indomethacin. UNaV was 109.3 +/- 25.7 muEq/min during control periods and was 69.6 +/- 21.0 muEq/min (0.05 less than p less than 0.1) after 80 min of infusion of indomethacin. The results suggest that renin release, sodium excretion, and blood pressure in the dog with chronic renovascular hypertension in uninfluenced by indomethacin.

Animals↗

The continuing challenge of duodenal injuries.

Thirty-four cases of duodenal trauma, 23 caused by gunshot wounds, are reviewed. All but three patients had associated major organ injuries, a total of 97 injuries. Postoperative mortality was 14% for injuries into the duodenal lumen. Techniques for operative repair included simple primary closure, use of omental or serosal patches, controlled fistula with a duodenostomy tube, decompressive and feeding ostomies, "diverticulization", segmental duodenal resection and anastomosis, and total duodenectomy and pancreatectomy. It is emphasized that the surgeon finding duodenal injury must be familiar with all of these techniques, each of which has its indications. Treatment of duodenal injuries perhaps more than any other bowel trauma must be individualized.

Adult↗

Role of prostaglandins in the control of renin secretion in the dog.

Infusion of indomethacin into anesthetized, salt-depleted dogs cuased an increase in mean arterial blood pressure (MABP), and decreases in heart rate (HR), urine flow rate (V), renal plasma flow (RPF), and renin secretion rate. MABP was 112.1 +/-5.4 mm Hg during control periods and was 147.7 +/- 5.6 mm Hg (P less than 0.005) 80 minutes after the infusion of indomethacin. V was 0.38 +/- 0.06 ml/min during control periods and was 0.08 +/- 0.01 ml/min (P less than 0.005) 80 minutes after the infusion of indomethacin. RPF was 126.3 +/- 13.3 ml/min and 41.5 +/- 7.5 ml/min, respectively (P less than 0.005), before and after 80 minutes of infusion. Renin secretion rate decreased from 1,194.1 +/- 353.9 U/min during control periods to reach 384.0 +/- 125.8 U/min (P less than 0.025) by 80 minutes of infusion of indomethacin. Subsequent infusion of prostaglandin E2 (PGE2) into the renal artery for 80 minutes caused increases of V to 0.53 +/- 0.13 ml/min (P less than 0.01), of RPF to 102.4 +/- 23.1 ml/min (P less than 0.01), and of renin secretion rate to 2,582.6 +/- 786.4 U/min (P less than 0.005). The decrease in renin secretion rate during the infusion of indomethacin persisted when renal perfusion pressure (RPP) was maintained relatively constant before and during the infusion of indomethacin. Furthermore, we found that infusion of prostaglandin E1 (PGE1) into the kidney gave the same pattern of response as PGE2. The data suggest that PGE1 and PGE2 play a role in the control of renin secretion.

Animals↗

Erythrocytes cultured from bone marrow.

The long-range objective of this study is in vitro tissue culture of bone marrow stem cells to produce erythroid cells of sufficient volume for clinical transfusion. Bone marrow from dogs and patients was cultured in 29 experiments lasting up to 15 weeks. Peripheral erythroid cells from dogs were cultured in three control experiments. Optimal tissue culture media was NCTC 109 augmented with vitamin B12, erythropoietin (EP), folic acid, and 9% fetal protein in 60 mm glass Petri dishes. Additional media and Step III EP was added at 2 to 4 day intervals. Peripheral erythroid cells in culture all were dead within 4 weeks. Marrow erythroic cells in culture proliferated as demonstrated by (1) Fe59 incorporation into cells during culture, (2) H3 thymidine uptake into cultured cells, (3) microscopic evidence of mitoses, and (4) total erythrocyte concentration in cultures far exceeding that of peripheral culture controls. For as yet unexplained reasons the total mature red blood cell concentration in the culture media remained essentially constant throughout the studies. This is a first step in achieving the ultimate goal of bulk erythrocyte production from tissue culture.

Animals↗

Management of small arterial injuries: clinical and experimental studies.

Twenty-five patients with 35 severed small arteries of the wrist, calf, or ankle are presented. Included are six cases of total ischemia of the wrist or ankle. Twenty-two repairs and thirteen ligations were performed. There was only one amputation from arterial insufficiency. We recommend repair both to preserve tissue and to restore optimum flow. By use of meticulous interrupted suture technique, optical magnification, and heparin and aspirin administration, a high degree of arterial patency can be achieved.

Aspirin↗

Increase in renin release after sionaortic denervation and cervical vagotomy.

The role of the vagi in the control of renin secretion was investigated in dogs maintained on a high-salt diet. Renal perfusion pressure was maintained relatively constant by the manipulation of a suprarenal aortic snare. Mean arterial blood pressure (MAP), plasma renin activity (PRA), and packed cell volume (PCV) increased after sinoaortic denervation and cervical vagotomy. Cooling of cervical vagi to 3-5 degrees C had the same effect as vagotomy. There was no change in MAP, PRA, and PCV in sham-operated animals. Propranolol prevented the increase in PRA following sinoaortic denervation and vagotomy, but not that in MAP or PCV. In splenectomized dogs, PCV still showed increases after sinoaortic denervation and vagotomy. It is suggested that the removal of sinoaortic and/or vagal inhibitory effects on the vasomotor center causes increases in sympathetic discharge to the adrenal medulla and the peripheral vessels, and that this in turn leads to the increase in MAP. The increase in sympathetic discharge to the adrenal medulla and the kidney causes the increases in PRA.

Animals↗

Ocular aspects of internal carotid stenosis.

Because extracranial atheromatous disease of the carotid arterial system is a common cause of 'stroke', ophthalmologists may be the first to see patients at risk who present with early signs of this condition. I. The history of previous observations of these signs and the anatomy and physiology of the structures involved are described. The physical and subjective signs and the significance of transient ischaemic attacks are discussed. Methods of diagnosis are reviewed with special reference to ophthalmodynamometry. II. A series of patients personally investigated and treated is analysed: (1)Endarterectomy was performed in seventy cases of internal carotid artery stenosis during a 15-year period (1959-73). (2) 36 cases from the years 1970-73 were studied in detail. (3) 50 per cent. of these presented with ocular symptoms, which were the only complaint in 22 per cent. (4) 95 per cent. of all patients with ocular symptoms experienced recurrent transient visual loss. (5) 61 per cent. of all patients with ocular symptoms showed significant fundus changes. (6) ODM enabled the haemodynamics of the carotid arterial systems to be evaluated in 79 per cent. of the patients studied. (7) The results of surgery suggest that patients who present with ocular symptoms have a better prognosis than those who present with neurological symptoms only.

Adult↗