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Biomedical subjects

A M Rokitansky

Publications and source records attributed to A M Rokitansky.

6 recordsLinked to original sources

Neovascularisation of the testes by experimental omentotesticulopexy.

With the currently used surgical procedures, surgical correction of extreme forms of high undescended testes is associated with an atrophy rate of 10% to 30%. In this experimental study in two groups of Sprague-Dawley rats of pubescent age, we examined whether fixation (pexy) of an omental flap on the testis (omentotesticulopexy = OMTX) permits preservation of the viability of the parenchyma. A left-sided OMTX was performed in group 1 with the animals under general anaesthesia. An omental flap was prepared. The tunica albuginea of the testis planned for OMTX was pierced with a needle (26 x 23 G) within an area with a diameter of 1 cm; a puncture distance of 2 mm was used. The omental flap was then fixed using absorbable monofilament 6-0 interrupted sutures. Six weeks later the spermatic vessel was transected at this site. The right testis was left untouched throughout the procedure; it remained in situ. In group 2 only the spermatic vessel on the left side was severed. The right testis was not manipulated and remained in situ. After a total of 10 weeks both testes were removed from all rats and fixed in formalin. Standardised haematoxylin and eosin staining was performed and histological sections were obtained. The size of the testicles, Leydig-cell count, viability, and calcified areas within the tissue were determined for all testicles. Student's t-test was used for statistical evaluation. The study showed that OMTX leads to neovascularisation in the area of fixation and that viability can be preserved within this area.

Animals↗

Special compression sutures: a new surgical technique to achieve a quick decrease in shunt volume caused by diffuse hemangiomatosis of the liver.

A new surgical technique for the management of shunting liver hemangiomas that otherwise would rapidly lead to intractable cardiac failure is presented. Rapid, significant reduction of shunt volume was achieved surgically by transhepatic compression sutures using PTFE pledgets and selective ligation of a large feeding vessel from the right hepatic artery.

Constriction↗

Influence of different conditioning methods on force and fatigue resistance in chronically stimulated skeletal muscles.

A study was undertaken to compare different conditioning methods for the transformation of latissimus dorsi muscle into a fatigue resistant one for application in circulatory assist. In ten sheep four electrodes were sutured to the epineurium of the left thoracodorsal nerve for indirect electrical stimulation of the latissimus dorsi muscle. In six sheep a "carousel stimulation," a special multichannel stimulation, in combination with a recently developed conditioning protocol was used for muscle conditioning (multichannel method). In four sheep, a conventional stimulation protocol using single channel stimulation was applied for transformation of the muscle (single channel method). The final experiments were carried out when fatigue resistance was obtained. The maximum tetanic forces at different preloads were determined and fatigue resistance was tested during 20 minutes of continuous stimulation. Both conditioning patterns led to fatigue-free chronic stimulation. Muscles conditioned by multichannel stimulation exhibited between 20% and 33% less force than the contralateral unconditioned muscles, whereas in the single channel group this loss was between 32% and 43%. Thus, the multichannel method revealed relatively superior in preserving muscle force for chronic stimulation.

Animals↗

Recent evaluation of prognostic risk factors in esophageal atresia--a multicenter review of 223 cases.

In this study, 223 cases of esophageal atresia (Type IIIb: 85.7%; Type II: 5.8%; Type IIIc: 4.0%; Type IIIa: 2.2%; Type IV: 2.2%) from 6 pediatric surgery centers of Austria, were retrospectively examined for the following parameters and their influence on the prognosis: Birth weight (2494.7 +/- 702.0 g), gestation week (range 27-42 weeks; mean 37.3 +/- 3.1 weeks), sex (male: n = 128; female: n = 95), long-gap atresia (> or = 2 cm: n = 33), Tracheomalacia (n = 16), associated malformations (n = 122; cardiac 27.4%, renal 17.9%, skeletal 17.0%, anal: 10.3%, intestinal 9.9%, mediastinal 7.6%, chromosomal 2.2%), preoperative aspiration (n = 92), pneumonia (n = 96), anastomotic insufficiency (n = 45), empyema (n = 5), mediastinitis (n = 8), sepsis (n = 32), other medical complications (n = 122, in 80 infants), other surgical complications (n = 57). The mortality rate was 41.3% overall, from 1975 to 1991; however, it was 25% from 1987 to 1991 and 0% in 1991. A statistically significant correlation was found between prognosis and the following factors: Cardiac malformations (p = 0.0001), medical complications except aspiration and pneumonia (p = 0.0001), empyema (p = 0.0081), mediastinitis (p = 0.0214), and sepsis (p = 0.0295). These 5 significant factors were given different points and a prognostic score was calculated by the addition of these points. This score was predictive for survival in 90.6% of cases and for mortality in 94% of cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Austria↗

Action of endogenous atrial natriuretic peptide in calves with experimental acute central venous congestion and low cardiac output.

STUDY OBJECTIVE: The aim of the study was to investigate plasma concentrations of atrial natriuretic peptide, aldosterone, and renin during experimentally induced acute central venous congestion. DESIGN: Two experimental calf models were used: (1) right heart failure due to pulmonary artery obstruction; (2) inferior vena cava syndrome produced by inferior vena caval obstruction. Hormonal responses and haemodynamic variables were measured over 6 h. SUBJECTS: Experiments were performed on three female "Schwarzbund" calves, age 3 months, weight 92 +/- 8 kg. MEASUREMENTS AND MAIN RESULTS: In the pulmonary artery obstructed group there was an increase of plasma aldosterone from 6.5(SEM 1.6) to 22.1(3.2) ng.dl-1 (p less than 0.05), of renin from 0.7(0.1) to 2.5(0.3) Goldblatt units x 10(-4).ml-1 (p less than 0.05), and of atrial natriuretic peptide from 22.1(4.5) to 141.4(27.8) pmol.litre-1 (p less than 0.05). During inferior vena caval obstruction, aldosterone increased from 2.4(0.4) to 20.9(2.0) ng.dl-1 (p less than 0.05), and renin increased from 0.4(0.05) to 2.0(0.20) Goldblatt units x 10(-4).ml-1 (p less than 0.05). In this experiment, atrial natriuretic peptide remained unchanged. Cardiac output decreased in both groups. There was significant fluid and electrolyte retention during both experiments, with urine volume decreasing from 87.7(11.6) to 35.0(1.2) ml-h-1 in experiment (1), and from 185(14) to 95.7(8.6) ml.h-1 in experiment (2). CONCLUSIONS: The study suggests (1) that in an experimental acute state of reduced cardiac output due to pulmonary artery stenosis with constantly increased right heart pressures, raised endogenous atrial natriuretic peptide failed to induce diuresis and natriuresis; (2) that in acute right heart failure, renin and aldosterone secretion could not be suppressed by raised atrial natriuretic peptide concentrations; and (3) atrial natriuretic peptide secretion seemed to be exhausted after 6 h continuous atrial distension.

Acute Disease↗