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Biomedical subjects

P Svendsen

Publications and source records attributed to P Svendsen.

At least 55 records · Page 3Linked to original sources
PubMed1994

Endovascular treatment of a spinal arteriovenous malformation in a 21-month-old boy.

Reports of spinal arteriovenous malformations in children are rare. This case report describes a 21-month-old boy whose first symptom was attacks of abdominal pain, followed gradually by neurological symptoms. The diagnosis was made using magnetic resonance imaging and spinal angiography, and the patient was successfully treated with embolization.

Aortography↗
PubMed1994

The effect of gastrin-releasing peptide on porcine pancreaticobiliary bicarbonate secretion is mediated by secretin.

The effect of gastrin-releasing peptide (GRP) (250, 500, 1000 pmol/kg.h) on the pancreaticobiliary bicarbonate secretion, the pancreatic protein secretion, and the plasma concentrations of secretin and cholecystokinin (CCK) was studied in the anaesthetized pig. Infusion of GRP (1000 pmol/kg.h) increased the portal plasma concentrations of secretin from 0.9 to 13.6 pmol/l and CCK from 1.2 to 38.4 pmol/l, the pancreatic bicarbonate secretion from 0.01 to 5.6 mmol/h, the hepatic bicarbonate secretion from 0.5 to 4.1 mmol/h, and the pancreatic protein secretion from 3 to 680 mg/h. Blocking of CCK-A receptors by MK-329 did not significantly change the effect of GRP, whereas prevention of secretin release by removal of the small intestine caused a 13-fold reduction in the GRP-induced pancreatic bicarbonate secretion and completely abolished the effect on hepatic bicarbonate secretion but did not change the effect on pancreatic protein secretion. We conclude that the effect of GRP on pancreaticobiliary bicarbonate secretion is not mediated through the release of CCK but more likely through the release of secretin and that the effect on pancreatic protein secretion is possibly a direct effect of GRP.

Animals↗
PubMed1994

Duodenal mucosal bicarbonate secretion in pigs is accompanied by compensatory changes in pancreatic and biliary HCO3- secretion.

BACKGROUND: The purpose of the study was to examine the effect of stimulation and inhibition of duodenal mucosal bicarbonate secretion on pancreatic and hepatic bicarbonate secretion in response to acid. METHODS: The effect of inhibition (indomethacin) or stimulation (misoprostol) of duodenal mucosal bicarbonate secretion on pancreatic and biliary bicarbonate secretion in response to intraduodenal infusion of HCl or intravenous infusion of secretin was studied in anaesthetized pigs. RESULTS: The hepatic and pancreatic response to exogenous secretin was not significantly altered by stimulation/inhibition of duodenal bicarbonate secretion. However, pancreatic and biliary bicarbonate secretion in response to duodenal acidification was significantly augmented by inhibition of duodenal mucosal bicarbonate secretion; conversely, it was reduced by stimulation of duodenal bicarbonate secretion. The increase in plasma secretin levels in response to duodenal acidification was reduced by stimulation and augmented by inhibition of duodenal mucosal bicarbonate secretion. CONCLUSIONS: Duodenal mucosal bicarbonate secretion can serve as a modulator of both pancreatic and biliary bicarbonate secretion in response to luminal acidification, possibly through regulation of the release of secretin.

Acid-Base Equilibrium↗
PubMed1994

Superselective transarterial embolization of renal arteriovenous malformations of cryptogenic origin.

Renal arteriovenous (AV) shunts of unknown origin are rare clinical findings. When symptomatic they can as other renal AV shunts and malformations cause hypertension, congestive heart failure and hematuria. During the last few years the treatment has tended to go from surgery to the more gentle and renal parenchyma sparing but yet effective endovacular embolization techniques. Two cases of renal vascular malformations with severe clinical symptoms necessitating treatment are presented. Treatment was successfully performed with tissue adhesive and coils.

Adult↗
PubMed1994

Instillation of alcohol into venous malformations of the head and neck.

Vascular malformations are errors of vascular morphogenesis, and must be differentiated from vascular tumours such as haemangiomas, because the natural history and treatment are different. Vascular malformations may be arteriovenous with high blood flow, or venous with low blood flow. Venous vascular malformations grow among soft tissues and are difficult to delineate at operation. Direct puncture under fluoroscopy with injection of contrast medium is one method of visualising the cavities of a venous malformation. Instillation of concentrated alcohol directly into such cavities is a possible treatment. Forty-four patients with venous malformations of the head or neck have been treated since 1984, of whom 31 responded to a follow up questionnaire. Twenty-three responded to injection of ethanol alone, and eight also required reconstructive surgery; 26 of the 31 described the result as "good" or "excellent" (84%).

Adolescent↗
PubMed1994

Spinal arteriovenous malformations. Health-related quality of life after embolization.

The overall function, pain and mood disturbances of 19 patients with spinal arteriovenous malformations (AVM), treated by embolization between 1983 and 1988, were studied. The after-care had taken place in different hospitals and clinics. The patients demonstrated markedly poorer physical function (Sickness Impact Profile) and poorer psychological well-being (Mood Adjective Check List) than control population samples and a comparison group of traumatic incomplete paraplegics. The degree of decrease of mood levels implied possible depressive disorder (Hospital Anxiety and Depression scale) in 16% of the patients and differed from that of the paraplegic comparison group. Furthermore, the AVM patients reported more disturbance of their family and social life than the paraplegics and they were more seldom gainfully employed. Patients recorded a wide range of pain scores, significantly worse than the paraplegics, and their pain was closely linked to overall quality of life (QL) perception. The QL scores were consistently related to all measures of functional and emotional status, but no connection with neurological lesion levels or medical complications was found. Specialised programmes after embolization, such as those offered in spinal injury units, would appear appropriate for AVM patients to improve their physical functioning and to provide a more rewarding social life.

Activities of Daily Living↗
PubMed1993

An animal model of focal, subacute, viral retinitis.

To study local intravitreal therapies for retinitis due to herpes viruses, an animal model of focal, subacute, relatively nonlethal herpes family retinitis is needed. Herpes simplex virus type 1 (HSV-1) was injected into the subretinal space of 33 Dutch pigmented rabbit eyes. The animals were observed for up to 42 days after the inoculation. All inoculated eyes developed a focal, enlarging area of retinitis in a predictable manner, showing focal enlarging areas of retinal opacification and necrosis with variable retinal hemorrhage. In the inoculated eyes, retinal detachment developed in all animals within 21 days; 33% of the animals developed focal retinitis in the uninoculated eye. Histologic examination showed encephalitis to be present in 11 (73%) of the 15 animals studied after 1 week. This model may be used to evaluate the therapeutic efficacy of new antiviral agents and modalities in the treatment of herpes family viral retinitis. The model is most similar to herpes simplex or zoster retinitis in humans, but also shares some similarities (and differences) with cytomegalovirus (CMV) retinitis in humans.

Acute Disease↗
PubMed1993

Redistribution of lymphocytes following E. coli sepsis.

Infusion of endotoxin elicits lymphopenia and a transient granulocytopenia followed by granulocytosis in peripheral blood. The purpose of this study was to investigate which tissues the lymphocytes are redistributed to in response to endotoxaemia. Lymphocytes were isolated from the peripheral blood of 20 rabbits, labelled with 111Indium-tropolene and reinjected intravenously into the rabbits. Ten rabbits received an infusion of Escherichia coli endotoxin 2 micrograms/kg-1, while 10 rabbits received isotonic saline and served as a control group. The redistribution of lymphocytes was imaged with a gamma camera, and calculated with an interfaced computer before, and 2, 4 and 6 h after infusion of endotoxin or saline. Interleukin-1 beta and serum cortisol were measured. Following endotoxaemia the lymphocytes in peripheral blood decreased from 1.95 10(9)/l to 0.83 6 h later. Interleukin-1 beta and serum cortisol increased significantly. The radioactivity of labelled cells in the spleen and in the heart and lungs decreased to 83.3% and 87.8% of initial values respectively, 6 h after infusion of endotoxin. The radioactivity of the lymphatic tissue in and around the intestine increased to 128.8% of initial values. The results indicate that endotoxaemia induces redistribution of lymphocytes from peripheral blood and spleen to lymphatic tissue.

Animals↗
PubMed1993

Redistribution of lymphocytes after major surgical stress.

Major surgery evokes an endocrine stress response, characterized by increased serum cortisol, plasma adrenaline and noradrenaline. Furthermore, surgical stress is accompanied by lymphopenia and granulocytosis in peripheral blood. The changes in peripheral white blood cells have been demonstrated after surgery as well as after cortisol infusion. The aim of the present study was to investigate to which tissues/organs peripheral blood lymphocytes are redistributed after major surgery. From 20 rabbits lymphocytes were isolated from peripheral blood, labelled with indium-111-tropolene and reinjected intravenously into the rabbits. Ten of the rabbits underwent major surgery (upper laparatomy) during general anaesthesia, while the control group (n = 10) was anaesthetized without surgery. The endocrine stress response to surgery was measured as serum cortisol, plasma adrenaline and noradrenaline. The redistribution of lymphocytes was imaged with a gamma camera and calculated with a connected computer before, 2, 4, and 7 h after the skin incision. Compared to preoperative values, laparotomy resulted in an increase in serum cortisol from 116.6 to 461.9 nmol/l (mean) and a decrease in the fraction/percentage of lymphocytes in peripheral blood from 43.8% to 14.7% 7 h after surgery. Simultaneously, the activity of the heart and lungs together decreased to 76.1% of initial values, while the spleen activity was unaffected. The radioactivity of the lymphatic tissue increased to 137.8% and 134.7%, respectively, 4 and 7 h after the start of surgery. The results indicate that major surgery induces a redistribution of lymphocytes from peripheral blood to lymphatic tissue. It is suggested that the endocrine stress response may be of major importance.

Animals↗
PubMed1993

Effect of stimulation of mucosal HCO3- secretion on acid-induced injury to porcine duodenal mucosa.

The effect of stimulation of duodenal mucosal bicarbonate secretion with vasoactive intestinal peptide (VIP) on acid-induced damage to the duodenal mucosa was studied in anaesthetized pigs in which bile and pancreatic juice were diverted from the duodenum. Mucosal damage was quantitatively assessed histologically, and mucosal blood flow was determined by means of radioactively labelled microspheres. Compared with placebo, intravenous infusion of VIP (500 pmol/kg/h) significantly stimulated duodenal mucosal bicarbonate secretion (47 +/- 13 versus 249 +/- 53 mumol/h) without concomitant changes in mucosal blood flow (51.5 +/- 7.8 versus 48.5 +/- 9.1 ml/min/100 g) or arterial bicarbonate concentration (24.2 +/- 1.1 versus 23.4 +/- 0.9 mM). The same dose of VIP increased the acid disappearance rate in the duodenum (2.2 +/- 0.14 versus 3.3 +/- 0.09 mmol/h) and reduced the extent of damage to the duodenal surface (16 +/- 2% versus 7 +/- 2%) during duodenal infusion of 0.03 M HCl but not 0.1 M HCl. We conclude that the protection offered by VIP against the small dose of acid is most likely secondary to the effect of VIP on mucosal bicarbonate secretion. Thus, this study suggests that duodenal mucosal bicarbonate secretion, independent of mucosal blood flow, is an integral factor in duodenal mucosal defence.

Analysis of Variance↗
PubMed1993

Combined embolization and gamma knife radiosurgery for cerebral arteriovenous malformations.

In a study of 46 patients with cerebral arteriovenous malformations (AVMs) the value of combining embolization and gamma knife radiosurgery was assessed. In 35 patients with large grade III to V AVMs (Spetzler-Martin system) staged combined treatment was planned. In 11 patients, radiosurgery complemented embolization for a residual AVM. The number of embolization sessions ranged from 1 to 7 (median 2). Twenty-six patients needed multiple embolization sessions. In 28 patients the grade of AVMs decreased as a result of embolization. In 16 patients collateral feeding vessels developed after embolization which made delineation of the residual nidus difficult. The time lag between the last embolization and radiosurgery ranged from 1 to 24 months (median 4). Nineteen of 35 large grade III to V AVMs were possible to treat by radiosurgery following embolization. In the 46 patients complications occurred in 9 from embolization and in 2 from radiosurgery. Two patients had transient and 9 had permanent neurologic deficits. It is concluded that embolization facilitates radiosurgery for some large AVMs and therefore this combined treatment has a role in the management of AVMs.

Adolescent↗
PubMed1992

Redistribution of lymphocytes after cortisol administration.

Major surgical procedures awake an endocrine metabolic stress response characterized by increased secretion of cortisol and lymphopenia. The purpose of this study was to clarify to which tissues the lymphocytes are redistributed after cortisol administration. Lymphocytes were isolated from 16 rabbits, labelled with indium-111-tropolone and reinjected into the rabbits. Eight of the rabbits received 25 mg of cortisol intravenously (group I), while eight received isotonic saline (group II). The redistribution of lymphocytes was imaged with a gamma camera and calculated by a connected computer before and two, four, and seven h after cortisol or saline administration. The radioactivity of cells from the spleen and bone marrow decreased to 84% and 56% of the initial values seven h after cortisol administration. The activity of the lymphatic tissues increased to 121% of initial values. It is concluded that during cortisol-induced lymphopenia the lymphocytes are redistributed from peripheral blood, spleen and bone marrow to lymphatic tissue.

Animals↗
PubMed1992

Relative importance of pancreatic, hepatic, and mucosal bicarbonate in duodenal neutralization of acid in anaesthetized pigs.

Pancreatic and hepatic bicarbonate secretion and the disappearance rate of acid during duodenal acidification were measured simultaneously in anaesthetized pigs. Perfusion of the duodenum with HCl resulted in an increase in both hepatic and pancreatic bicarbonate secretion. During all acid loads hepatic bicarbonate secretion was significantly greater than pancreatic secretion. Furthermore, the disappearance rate of acid in the duodenum during diversion of both bile and pancreatic juice was significantly greater than the amount of acid which could be neutralized by the concomitant pancreatic bicarbonate secretion. Diversion of pancreatic juice from the duodenum did not affect the disappearance rate of acid at any acid load, whereas diversion of bile caused a significant decrease. Thus, in the anaesthetized pig the liver and the duodenal mucosa are of greater importance than the pancreas for the neutralization of acid in the duodenum. It is suggested that the importance of the pancreatic contribution to duodenal neutralization should be reevaluated in other species, including man.

Animals↗