摘要:

The pulmonary vascular and systemic effects of PGE1 were studied in a canine model of pulmonary hypertension. Systemic arterial, central venous and pulmonary arterial pressures were monitored and an electromagnetic flow probe was placed around the ascending aorta for continuous cardiac index (CI) measurements. Through a laparotomy, an arteriovenous fistula was created between the abdominal aorta and inferior vena cava. Gradual opening of this fistula significantly affected CI and these values were used to generate pressure-flow curves (pulmonary arterial pressure (PAP)/Cl). Following PGF2α infusion (5–10 µg/kg/min) significant pulmonary hypertension was observed (2- to 3-fold increase in PAP). PGF2α infusion also resulted in a significant rise in heart rate and systemic vascular resistance (SVR) while CI was reduced. PGF2α significantly increased both the line slope (vascular resistance) and intercept (outflow pressure) of the pressure-flow curves. Intravenous PGE1 infusion in doses ranging from 40 to 320 ng/ml/min elicited a dose-dependent reduction of both pulmonary and systemic vascular resistances, the former being slightly more affected. With PGE1 infusions only the intercept of the pressure-flow curve was affected suggesting that specific components of the pulmonary vascular bed modulating the outflow pressure were involved. High doses of PGE1 significantly decreased arterial Po2, indicating that this prostaglandin derivative deteriorates pulmonary gas exch

ISSN:0014-312X    

DOI:10.1159/000129259

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The purpose of the present study is to ascertain the immunorestorative effect of two different drugs on immunodepression induced by small bowel surgical resection in an experimental model. The potential immunorestorative effect has been measured by the ability of the drug to avoid the delay of skin allograft rejection induced by surgery and the inhibition of CD4/CD8 index changes induced by surgery in spleen tissue. 120 Wistar-Furth rats (age 12–16 weeks) anesthetized with a single intramuscular dose of ketamine (25 mg), diazepine (4 mg) and atropine (0.1 mg) were allotted to two main groups. One group received a skin graft (SG) from Fisher 344 rats and was treated with placebo, Inmunoferón® (AM-3 polypeptidic drug) or TP-II (thymostimulin) before the experiment (groups I, II, III) or treated with placebo, Inmunoferón or TP-1 before the experiment and underwent enterectomy and anastomosis (groups IV, V, VI). On the 2nd, 5th and 8th postoperative days, biopsies of the SG were taken and the signs of rejection were microscopically studied and evaluated by a pathologist as zero, incipient, moderate or massive. The other group was treated similarly, but the animals did not receive a SG and were splenectomized 5 days later. CD4 and CD8 lymphocyte subpopulations were identified by means of immunoperoxidase technique and monoclonal antibodies. Thymostimulin is able to stimulate the presence of SG rejection signs on the 2nd postoperative day in nonenterectomized animals and on the 8th postoperative day in enterectomized rats and is able to avoid the decrease of the CD4/CD8 index in spleen tissue after surgical immunodepression. AM-3 has less effect on the presence of SG rejection signs and CD4/CD8 index than thymostim

ISSN:0014-312X    

DOI:10.1159/000129260

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Trauma favors the development of adult respiratory distress syndrome (ARDS). Adherence of polymorphonuclear leukocytes (PMN) to endothelial cells (EC) with subsequent EC damage by the respiratory burst products and proteases of the PMN is thought to be one of the basic mechanisms in the pathogenesis of ARDS. Recent studies have shown that there might also be PMN-independent mechanisms of EC damage. It would speak for PMN-independent EC damage if in the state of risk for this damage factors were found which decrease PMN activity or if EC damage appeared without PMN. Because in trauma and sepsis pathologic coagulation with high levels of fibrinogen degradation products (FDP) is often diagnosed, we investigated whether FDP-D and FDP-E might influence PMN adherence to EC. We also investigated whether serum of traumatized patients might provoke EC damage in a PMN-independent system in vitro. To achieve this we evaluated the viability of EC using a fluorescence staining method. We found that both FDP-D and FDP-E decreased PMN adherence to human EC significantly (p < 0.01) at a concentration of 50 µg/ml. Furthermore we found that EC membrane integrity can be disturbed by serum of trauma patients. These results suggest that in trauma also PMN-independent mechanisms are important for EC damage

ISSN:0014-312X    

DOI:10.1159/000129261

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The activities of ATP-synthetase and ATPase in rabbit liver were evaluated by kinetic analysis of rapid changes in ATP during alteration of oxygen supply, and were compared between normal and hepatectomized rabbits. Velocity constants of ATP-synthetase and ATPase were computed on the assumption that ATP-synthetase and ATPase follow the pseudo-first order reaction of ADP and ATP, respectively. The velocity constant of ATPase increased from the control value of 0.21 to 0.48 (min–1) in the remnant rabbit liver at 24 h after 70% hepatectomy. The velocity constant of ATP-synthetase increased from the control value of 4.05 to 5.24 (min–1) after the hepatectomy. These results indicate that both ATP-synthetase and ATPase are accelerated due to liver regenerat

ISSN:0014-312X    

DOI:10.1159/000129262

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

We investigated the effect of portal hypertension over time on gastric epithelial proliferation in rats. Portal-vein ligation (PVL) was applied to fourteen Wistar rats to produce experimental portal hypertension: seven rats (PVL2) had histological analysis after 2 months and the remaining seven (PVL4) after 4. An additional group of seven was employed as a control. Each rat was injected with bromodeoxyuridine and killed an hour later to assess gastric epithelial proliferation by an immunohistochemical staining technique. The labeling index between PVL and control animals differed significantly (p < 0.05). Labeling indices in fundic mucosa were 5.7 ± 0.2% in controls, 3.9 ± 0.3% in PVL2 rats and 4.0 ± 0.3% in PVL4 rats, while in antral mucosa the corresponding figures were 7.5 ± 0.6, 4.6 ± 0.3 and 4.0 ± 0.3%. In neither fundic nor antral mucosa was the total mucosal thickness significantly different between the control and PVL rats. In the PVL2 group, the frequency distribution of labeled cells showed a shift toward the mucosal surface in fundic glands. No significant differences between the two PVL groups were observed in any of the studied parameters. This study suggests that portal hypertension may inhibit gastric epithelial proliferation in

ISSN:0014-312X    

DOI:10.1159/000129263

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Autologous hepatocellular transplantation using reflux into the spleen via the venous tributaries was compared in 65% hepatectomized dogs to direct injection into the splenic pulp. Transplantation into the spleen via the inferior terminal polar splenic vein led to a better survival rate (50 vs. 0%). Hepatocytes embolization to the intrahepatic portal vein system was observed. Although hepatocyte transplantation into the spleen can be accomplished either by direct punction of the spleen or by retrograde injection into a splenic vein, the second method decreases the frequency of cell embolization.

ISSN:0014-312X    

DOI:10.1159/000129264

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Cardiomyoplasty is a new surgical procedure using transformed skeletal muscle to reinforce or substitute for the myocardium. For the purpose of studying surgical technique and investigating basic questions, we have developed a model of reinforcement cardiomyoplasty. Herein, we describe anesthetic management, surgical technique, and the technique for iterative transthoracic biopsies. This model has proven to be valuable in several long-term studies involving more than 30 goats. Preliminar data to ascertain the efficacy of the proposed technique are provided.

ISSN:0014-312X    

DOI:10.1159/000129265

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Three types of colonic sphincter substitutes were placed at an abdominal colostomy in dogs. Simple valve construction (8) was based on orthograde intussusception of the colon over 3.5 cm. In calibrated valves (6) the intraluminal pressure was increased by reducing the diameter of the overlying muscle coat. Reverse smooth muscle plasties (5) and simple colostomies (5) served as controls. Immediately after construction highest pressure (50 ± 8.9 mm Hg) was obtained in calibrated valves. After 1 month the pressure dropped to 20 mm Hg, but remained stable thereafter. Although valvular constructions cannot maintain high pressure, they may be useful as substitutes for the internal anal sphincter by filling up the lumen so that the action of a surrounding striated muscle ring becomes more effective

ISSN:0014-312X    

DOI:10.1159/000129266

出版商:S. Karger AG    

年代:1993

数据来源: Karger