Beneficial effect of cyclooxygenase inhibition on adverse hemodynamic responses after protamine

The hypothesis that adverse effects observed when heparin is antagonized by protamine are mediated by metabolites of the arachidonic acid cascade was tested during general anesthesia (enflurane, fentanyl) in 16 pigs classified into two groups. In the first group (n = 9), effects of intravenously administered protamine on systemic hemodynamics, blood/gas tensions, and arterial and mixed-venous prostanoid levels were studied. The second group (n = 7) was pretreated with indomethacin 10 mg/kg, and the same measurements were made. All pigs received heparin 150 units/kg. When protamine 1.1 +/- 0.1 mg/kg was administered over 3 minutes, marked hemodynamic alterations were observed in group 1: pulmonary artery pressure and pulmonary vascular resistance increased, and left ventricular end-diastolic and systemic arterial pressures decreased. Arterial and mixed-venous PO2 values deteriorated in all pigs in group 1 at the end of protamine infusion. These alterations were accompanied by significantly elevated prostanoid levels in arterial and mixed-venous plasma samples: Thromboxane A2, prostaglandin F2 alpha, KH2-PGF2 alpha (a metabolite of prostaglandin F2 alpha), and prostacyclin were maximally elevated at completion of protamine and remained significantly above control values at 5 minutes but were not significantly different from control after 10 minutes. Blocking the cyclooxygenase cascade by pretreatment of the pigs with indomethacin (group 2) prevented hemodynamic and blood gas alterations. It is concluded that in pigs the detrimental side effects associated with the use of protamine to reverse heparin are mediated by metabolites of the cyclooxygenase cascade.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of Peyer's patches on the organ-specific distribution of IgA plasma cells

After the surgical removal of Peyer's patches (PP) in rats, the IgA-containing cells in the thoracic duct, mesenteric lymph nodes and lamina propria of the small intestine are decreased, as shown by immunohistology. The analysis of the immunoglobulin secretion in agar of single-cell suspensions confirmed these results. Using lipopolysaccharide (LPS) 055B5 as antigen, it could be demonstrated that this reduction may be the result of an inadequate presentation of antigen and/or impaired migration of locally primed antigen (AG)-specific cells. The oral application of heat-inactivated Escherichia coli 055B5 to PP-deprived rats resulted almost exclusively in anti-LPS-secreting cells in the mesenteric lymph nodes and spleen, whereas in control animals these cells were distributed along the intestine. Therefore, in rats PP have an important function in the regulation of the intestinal immune responses.

Passage of stone fragments from the gallbladders of dogs

The destruction of gallstones by shock waves leads to a considerable amount of stone fragments in the gallbladder. To test the ability of the stones fragments to leave the gallbladder, kidney stone fragments of 2 or 4 millimeters maximal diameter were implanted into the gallbladders of 16 dogs and passage was observed for five weeks. Independent of stone size, about 35 per cent of the fragments remained in the gallbladder. Transient elevations of enzymes of the liver or pancreas occurred significantly less often with 2 millimeter fragments and were less pronounced. Gross pathologic changes of the papilla of Vater, or dilation of the bile duct were observed with 4 millimeter fragments but not with those that were 2 millimeters. The results of this study suggest that the maximal fragment size after destruction of gallstones should be as small as possible, that is, in the range of 2 millimeters.

Shock-wave lithotripsy of gallbladder stones. The first 175 patients

To substantiate the early results of extracorporeal shock-wave fragmentation of gallstones, we used this nonsurgical procedure to treat 175 patients with radiolucent gallbladder calculi. Chenodeoxycholic acid and ursodeoxycholic acid were administered as adjuvant litholytic therapy. The gallstones disintegrated in all patients except one and completely disappeared in 30 percent of all patients within 2 months after lithotripsy, in 48 percent at 2 to 4 months, in 63 percent at 4 to 8 months, in 78 percent at 8 to 12 months, and in 91 percent at 12 to 18 months. In patients with solitary stones up to 20 mm in diameter, the corresponding values were 45, 69, 78, 86, and 95 percent, respectively. Shock-wave therapy had no adverse effects except cutaneous petechiae (14 percent) and transient gross hematuria (3 percent). One third of the patients had one or more episodes of biliary colic before all the fragments disappeared. Two patients had mild pancreatitis, which necessitated endoscopic sphincterotomy in one. The patient with insufficient stone fragmentation underwent elective cholecystectomy; no additional operations were necessary. Extracorporeal shock-wave lithotripsy combined with medical therapy for stone dissolution is a safe and effective treatment in selected patients with radiolucent gallbladder calculi.

Biliary stones: treatment by shock-wave lithotripsy

Extracorporeal shock-wave lithotripsy has been introduced as a novel nonsurgical therapy for gallstone disease. To substantiate the initial results, more than 400 patients with biliary calculi have been treated. In selected patients with gallbladder stones, complete clearance of all stone fragments can be expected within 1 year in about 80%. In patients with bile-duct stones not amenable to endoscopic measures, sufficient stone fragmentation by extracorporeal shock waves was achieved in about 80%. Extracorporeal shock-wave lithotripsy is a safe and efficient therapy for selected patients with gallbladder calculi. For patients with bile-duct stones not amenable to endoscopic measures it offers a nonsurgical alternative.

Protective effect of an outer membrane vaccine against Pseudomonas aeruginosa infection

The outer membrane proteins, F, H2 and I, from PA12 strain of Pseudomonas aeruginosa, were purified and used successfully for immunization of Balb/c mice. The immunized mice were protected against challenge with a 2-26 fold LD50 of all known 19 serogroups of P. aeruginosa.

Influence of postdiabetic onset time and immunosuppressive treatment on islet grafts in the spontaneous diabetic BB/W rat

1000 islets from one donor, isolated with a modified neutral red method, were intraportally transplanted from BB/Wistar or Lewis (RT1) donors to short- and long-term diabetic BB/Wistar recipients. Recipients received immunosuppression with cyclosporine i.m.--either postoperative 4 X 25 mg/kg body weight or pre- and postoperative 3 X 10 mg and 4 X 25 mg/kg body weight. Graft survival in short-term diabetic recipients was significantly shorter than in long-term diabetics, whether they were immunosuppressed or not. Especially in recent onset recipients, the additional preoperative immunosuppression with cyclosporine provided longer graft survival than postoperative cyclosporine alone. Histological examinations of islet grafts showed eosinophilic cells in all transplanted islets, in both functioning and clinically rejected grafts of allogenic and "pseudoisogenic" transplanted recipients. a coincidence of eosinophilic cells with the reenactment of the original autoimmune disease in islet grafts seems possible.

Role of Peyer's patch in the intestinal immune response to cholera toxin in enterically immunized rats

Cholera toxin has been widely used to obtain insight into the cellular dynamics of the antigen-specific mucosal immune response. The present study was undertaken to clarify the influence of the organized intestinal lymphoid tissue (Peyer's patches [PP]) on the distribution of anti-cholera-toxin-containing cells (ACC) after intraperitoneal immunization and intraduodenal challenge with purified cholera toxin. This was done in rats which were surgically deprived of all visible PP. In comparison with sham-operated animals, each PP-deprived rat had nearly the same amount of ACC in the spleen, the mesenteric lymph nodes, and, surprisingly, the thoracic duct lymph. In contrast, the ACC in the duodenum, the jejunum, and the ileum of each PP-deprived animal were drastically reduced. Therefore the PP are suggested as an important organizing structure for the buildup of a local antigen-specific immune response.

The effectiveness of a fibrinogen-thrombin-collagen-based hemostatic agent in an experimental arterial bleeding model

The hemostyptic agent used in this study is a recently developed material that consists of a collagen fleece containing fibrinogen, thrombin, and aprotinin integrated into its surface (FTCH) with excellent topical hemostyptic properties. The potential use of this substance for cardiovascular surgery was evaluated in a canine arterial bleeding model, which allowed comparison of the new agent with previously used pure collagen (CHF) as well as study of the hemostyptic under elevated blood pressure conditions. The results revealed that FTCH induced reliable hemostasis in 10-mm injuries of the canine hypogastric artery up to a systolic blood pressure of 260 mmHg, whereas bleeding control by CHF alone was impossible. To assess the long-term reliability of FTCH, the dogs were re-explored at intervals of 14 and 31 days after operation. At relaparotomy, the arteries were patent and there was no evidence of recurrent bleeding, thrombosis formation, or aneurysmatic changes. Histologic examinations showed well-healed vascular lesions covered by cell-depleted collagen tissue and a partially resorped hemostyptic. FTCH will not replace adequate surgical techniques but could be useful as a quickly available and easily applicable hemostatic means in otherwise uncontrollable diffuse or acute bleeding in cardiovascular surgery.

[Effectiveness of various immunoglobulin preparations administered by the intravenous route in peritonitis in the rat model]

Intraabdominal sepsis in rats was induced as a sublethal infection (mortality rate of controls: 60%-80%) and as a lethal infection (mortality rate of controls: 100%). The effectivity of different immunoglobulin (IgG) preparations alone or together with an antibiotic combination therapy (gentamicin + piperacillin) was then tested. In sublethal infection, 5 intravenous administrations of three 7S-IgG preparations and a plasmin-treated preparation at a dosage of 0.5 g/kg b.w. were able to reduce lethality only slightly, whereas a 5S-IgG preparation was able to reduce lethality by 30% significantly. Intraperitoneal administration of two 7S-IgG preparations (s-sulfitolysis, 42 degrees C/ammonium sulfate) and the 5S-IgG preparation reduced lethality to 27%, 37% and 47%, respectively, whereas another 7S-IgG (iodoacetamide/dithiothreitol) and a plasmin-treated preparation failed to reduce lethality significantly. The convincing results obtained with the 5S-IgG preparation are probably due to the fact that Fc-mediated side-effects could be avoided. The better effectivity of intraperitoneal compared to intravenous administration can be explained by much higher concentrations of specific antibodies at the site of infection. In the lethal infection model the mortality of animals treated with antibiotics only was 50%. The additional intravenous administration of 7S-IgG (42 degrees C/ammonium sulfate), a plasmin-treated preparation and a 5S-IgG was unable to reduce mortality any further. These findings are in contrast to several publications which postulate synergism of antibiotics and immunoglobulins.

A new model for hetero-orthotopic heart-lung transplantation in the dog

A method of hetero-orthotopic heart-lung transplantation is described in the dog. The model was developed to study patterns of rejection in the transplanted heart and lung, since the dog will not survive bilateral pneumonectomy and loss of the Hering-Breuer reflex. After removal of the recipient's left lung the donor heart and left lung are explanted en bloc. End-to-end connection is made of both left main bronchi, and the donor aorta is joined end-to-side with the recipient's descending aorta. An atrio-atrial anastomosis is performed between the recipient's left and the donor's right atrium. Four experiments were done to develop the surgical technique and 10 long-term studies were performed to investigate rejection patterns. The average survival rate of these animals was 28.5 +/- 8.3 days, ranging from 5 to 53 days. Causes of death were not due to operative complications. Heterotopic heart-lung transplantation is an uncomplicated surgical method which does not require cardiopulmonary bypass or anticoagulation and allows the investigator to study heart and lung grafts in dogs for long-term periods after surgery. Bronchoscopy, bronchoalveolar lavage, and heart and lung biopsies of both donor and recipient organs can be performed.

[Effects and side effects of taurolin in experimental peritonitis in the rat]

Taurolin (2%) was tested in a peritonitis in the rat. In a control group without treatment the mortality was 63% 80 h after infection. Intraperitoneal application of taurolin did not change this mortality rate but delayed the mortality by 8 h. Intravenous administration of taurolin increased mortality to 87%. In a second experimental protocol the dosis of bacteria was increased and 100% of the animals died within 16 h. Gentamicin-Piperacillin therapy reduced the mortality to 50%. With taurolin this effect of antibiotics could not be improved. In both groups taurolin was not able to reduce toxic lung edema. With these results and the knowledge of the literature taurolin cannot be recommended for clinical use.

Peripheral blood and intrarenal phagocytic chemiluminescence during acute kidney graft rejection

During organ graft rejection, soluble mediators of inflammation are released into the polymorphs (PMNs) and monocytes recruited from the blood. One functional capacity of polymorphs and monocytes/macrophages is the production of cytotoxic activated oxygen species upon stimulation, which may contribute to the rejection process. Nothing is known about the influence of allograft rejection on this inflammatory cell property. Chemiluminescence (CL) allows measurement of respiratory burst capacity in small cell samples. Zymosan-induced and luminol-amplified CL of diluted whole blood, separated PMNs, and mononuclear cells from peripheral venous blood, as well as of intragraft phagocytes was measured after allogeneic and autologous kidney transplantation in untreated dogs. CL of separated PMNs, mononuclear cells, and intragraft phagocytes was significantly elevated during allograft rejection. In autologous kidneys transplanted to recipients of allografts, CL was also increased in the autologous grafts during rejection of the allogeneic ones, indicating a systemic alteration in phagocyte function.

Induction of oral tolerance in rats without Peyer's patches

The induction of oral tolerance after ingestion of antigen has been reported in several animal models. The precise mechanisms responsible for this unresponsiveness are not well understood. As some investigations have suggested a key role of Peyer's patches suppressor T cells, an animal model was developed in which the PP were surgically removed. Using this model, the influence of the PP on the induction of oral tolerance against SRBC was investigated. In order to induce tolerance, the rats were fed SRBC on four consecutive days. On Day 5 they were i.p. challenged by injection of SRBC, and 5 days later the number of immunoglobulin-secreting cells against SRBC was determined within the spleen. Using this protocol, the oral tolerance induction could be shown very clearly in control animals as well as in rats without PP. Therefore, tolerance induction is possible in the absence of PP-T cells. Other mechanisms must be responsible for the tolerance induction in this model.