PubMed Health⌕ Search

Biomedical subjects

A Keiler

Publications and source records attributed to A Keiler.

At least 19 recordsLinked to original sources
PubMed1996

Intraperitoneal cholelithiasis after laparoscopic cholecystectomy--behavior of 'lost' concrements and their role in abscess formation.

UNLABELLED: In two experimental studies we sought preliminary information about the behavior of concrements lost in the peritoneal cavity during laparoscopic cholecystectomy. MATERIALS AND METHODS: In study 1, human gallstones were analyzed using X-ray diffraction, classified in three groups and examined with an ultramicroscope; then they were implanted in the peritoneal cavity of rats. After 8 weeks or 6 months, the animals were sacrificed and the concrements analyzed again as before. The tissues surrounding the calculi were also examined histologically. In study 2, human gallstones were examined with regard to bacterial contamination on the surface or in the middle of the calculi. The cholesterol content was analyzed, and the stones were divided into three groups and implantated in the rats as in the first study. After 8 weeks, the animals were sacrificed and areas with identifiable tissue reactions were examined histologically and microbiologically. RESULTS: The concrements lost their crystalline formation without any relation to their former cholesterol content, as shown by X-ray diffraction as well as ultramicroscopy. Mineralogically, these changes are a certain sign of structural dissolution. Cholesterol stones only caused abscess formations in association with gram-negative bowel germs. Sterile pigment concrements often led to a mesenchymal reaction such as granulomas. Contaminated pigment stones also resulted in extensive abscess formations.

Abscess↗
PubMed1995

Isradipine increases vascular prostaglandin I2-formation while the thromboxane B2-synthesis is diminished.

PGI2- and TXA2-synthesis from vascular tissue samples derived from cultured (endothelial and smooth muscle) cells, rabbit aorta and human bypass surgery were determined using specific radioimmunoassays for the stable derivatives (6-oxo-PGF1a and TXB2, respectively) of these compounds. Cultured cells were incubated in presence of isradipine, rabbits were pretreated for 4 weeks receiving 0.3 mg isradipine/kg*day, while patients were on isradipine (5-10 mg total dose/day, per os twice daily) since 6-19 weeks. In presence of isradipine, cultured cells produced significantly (p < 0.01) more 6-oxo-PGF1a and significantly less TXB2 (p < 0.05). 6-oxo-PGF1a-formation in rabbit aorta was significantly (p < 0.01) higher in isradipine treated normocholesterolemic animals while no significant changes were seen in isradipine treated hypercholesterolemic animals. TXB2 was significantly (p < 0.01) depressed in the abdominal and the thoracic aortic segment of isradipine treated hypercholesterolemic animals and was not significantly influenced in isradipine treated normocholesterolemic animals. Similarly, PGI2-synthesis in human arterial specimen was significantly (p < 0.01) enhanced as compared to the untreated controls. These findings indicate a beneficial behaviour of isradipine on vascular wall eicosanoid profile, which may contribute to a variety of antiatherosclerotic actions at the vascular wall level and to an improvement in hemostatic balance already described.

Aged↗
PubMed1995

Arterial wall rather than platelets is responsible for diminished thrombogenicity during isradipine therapy.

We investigated whether the vessel wall or platelets are primarily responsible for the decreased thrombogenicity induced by the calcium channel blocker isradipine after endothelium removal. In a cross-perfusion model, rabbit aorta and iliac artery endothelium of receiver animals were removed by balloon catheter before being perfused with the blood of the blood donor rabbits. Donor and/or receiver animals were treated with 0.3 mg/kg isradipine intravenously (i.v.) daily for 1 week or with 10 mg acetylsalicylic acid (ASA) in addition. The other animals received vehicle only or ASA. The animals were divided into four groups (I-IV, total n = 24) consisting of four subgroups of 6 animals each. In all, 96 rabbits were examined. Immediately after the last administration of the respective drug, native blood from a donor rabbit was circulated (30 ml/min) through a deendothelialized segment of a receiver rabbit. The contract (C) and spread (S) platelets as well as the denuded surface covered with platelet aggregates (> 5 microns high) were quantified by morphometry. Deposition of [111In]oxine-labeled platelets was quantitatively determined per surface unit. In addition, prostaglandin I2 (PGI2) formation by the denuded aortic and iliac artery segment was determined. In group I, receiver rabbit pretreatment with isradipine exhibited decreased adhesion and aggregation of platelets, even when the donor rabbit was treated with solvent or ASA. In group II, concomitant treatment of donor animals with ASA and isradipine had no significant effect, whereas ASA isradipine treatment of receiver animals enhanced thrombogenicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Isradipine decreases arterial thrombogenicity in rabbits. A morphometric and radioisotopic study.

The effect of isradipine, a calcium antagonist, on aortic and iliac wall thrombogenicity was examined in rabbits. After one week of dosing, the abdominal aortic and iliac artery endothelium was abraded using a Fogarthy catheter. One group of animals (n = 8) was dosed for one week with isradipine 0.3 mg/kg. A second group of animals received 10 mg acetylsalicylic acid (ASA)/kg daily in addition, while a third group received the vehicle only. Finally, a fourth group of animals (n = 8) was treated with ASA only. The percentage denuded surface covered with contact (unspread) platelets decreased significantly (p < 0.01) from 14.7 +/- 2.0 to 9.3 +/- 2.1 (6.2 +/- 0.8 to 3.7 +/- 0.4). The amount of contact and spread platelets was diminished from 84.9 +/- 5.6 to 71.4 +/- 4.4 (91.8 +/- 5.3 to 75.2 +/- 4.6). Platelet thrombi decreased from 7.4 +/- 0.9 to 4.6 +/- 1.4 (9.4 +/- 1.9 to 5.2 +/- 0.7) in the aortic and the iliac artery, respectively. In-platelet deposition decreased by 39.9 and 41.9%. Concomitant ASA therapy not only abolished the effect of isradipine but enhanced thrombogenicity, probably as a result of almost complete blockade of vascular PGI2-production.

Animals↗
PubMed1994

Isradipine inhibits mitotic and proliferative activity in the arterial wall.

The anti-mitotic (3H-thymidine uptake quantified using autoradiography) and anti-proliferative (counting of activated smooth muscle cells on semithin sections) effects of the dihydropyridine calcium channel blocker isradipine (0.3 mg/kg) have been assessed in a rabbit arterial stress model. Isradipine caused a significant drop in both mitotic and proliferative activity. These effects were more pronounced by pretreatment (6 hours before lesion induction with desoxycorticosterone) with isradipine as compared to posttreatment (6 hours after experimental lesioning). The benefit induced by isradipine was abolished by aspirin treatment. In-vitro vascular prostacyclin formation and cholesterol content were not affected. These findings suggest that the anti-atherosclerotic action of isradipine on mitotic activity and cellular proliferation is mediated by a cyclooxygenase product, most likely via enhanced local vascular PGI2-synthesis.

Animals↗
PubMed1994

[Laparoscopy-assisted reoperation after sigmoid resection and Hartman rectal occlusion].

The anastomosis between the descending colon an the rectal stump after sigma-resection and blind closure of the rectum according to Hartmann could be performed as well via an open laparotomy approach as via a laparoscopic procedure. By means of a first group of five laparoscopically reoperated patients the authors are demonstrating the good practicability of their laparoscopic method. Extended adhesions in the pelvic area could be detached in all cases. The advantages of this laparoscopic operation are obvious and in the authors opinion laparoscopic assisted reconnection between colon and rectal stump seems to be a serious alternative to open surgery by laparotomy.

Adult↗
PubMed1992

13,14-Dihydro-prostaglandin E1 decreases low-density lipoprotein influx into rabbit aorta.

The effect of 4-week daily administration of 13,14-dihydro-prostaglandin E1 (13,14-DH-PGE1; 2 micrograms/kg) on LDL influx into the rabbit aortic wall was examined versus the effect of the same dose of PGE1 and sham-treatment in 108 male animals fed an 1% cholesterol supplemented diet. Treatment was started after de-endothelialization of the abdominal aorta with a Fogarty catheter. After the 1-month treatment period the animals were injected with 10 microCi 125I-low-density lipoprotein (LDL; 0.5 mg protein/ml). Uptake of the radiolabelled LDL was measured in morphologically verified endothelialized, re-endothelialized and de-endothelialized abdominal aortic segments. The LDL influx into the aorta was significantly (P less than 0.001) lower in 13,14-DH-PGE1- and PGE1-treated rabbits than in the controls. This reduction was most pronounced in re- and de-endothelialized segments. No significant difference between effect of PGE1 and of its biologically active derivative, 13,14-DH-PGE1, on arterial LDL entry was found. These data demonstrate a comparable beneficial effect of 13,14-DH-PGE1 and PGE1 on vascular wall lipid metabolism by decreasing LDL entry into the aortic wall in vivo.

Alprostadil↗
PubMed1992

Concomitant aspirin treatment abolishes the antiatherosclerotic effects of the calcium channel blocker isradipine mediated by PGI2.

108 male rabbits, aged 6 months, with experimental hypercholesterolemia and experimental abdominal aortic lesioning received different regimen of antiatherosclerotic treatment; 36 of them were treated with isradipine, a dihydropyridine calcium antagonist (0.3 mg/kg/daily), 36 with isradipine in combination with aspirin whereas 36 animals received placebo. The entry of 125I-radiolabelled LDL into the aorta was demonstrated to be significantly diminished in isradipine-treated rabbits as well as positive Sudan-III-staining and aortic cholesterol content were in comparison to placebo. This benefit was almost completely abolished by concomitant aspirin-treatment. The notable increase in vascular prostacyclin (PGI2) is supposed to mediate the strong antiatherosclerotic effect of isradipine resulting in an inhibition of LDL-entry and vascular cholesterol accumulation. Aspirin almost totally blocked the raise in PGI2-synthesis by the inhibition of cyclooxygenase detected in isradipine-treated animals. It can be concluded, that aspirin-treatment may minimize the antiatherosclerotic actions of calcium antagonists which are mediated by the PG-system.

Animals↗
PubMed1992

The diminished extracellular matrix production induced by isradipine, a calcium channel blocker, is completely abolished by cyclooxygenase inhibition.

Collagen and glycosaminoglycan synthesis are well known to be enhanced during early atherogenesis. In this experimental study the synthesis of collagen was determined using 14C proline incorporation, the glycosaminoglycan production by means of 35S-sulphate incorporation and subsequent quantification by means of autoradiography. Isradipine, a new calcium channel blocker of the dihydropyridine family at a dose of 0.3 mg/kg significantly (p less than 0.01) decreased the incorporation of both the radioactive precursors. This effect was abolished by a concomitant aspirin treatment, while aspirin alone did not exert any significant effect on the precursor incorporation. These data suggest that isradipine, which is known to stimulate PGI2 synthesis, may exert this antiatherosclerotic inhibitory action on extracellular matrix production via the endogenous liberation of PGI2.

Animals↗
PubMed1992

[The cystic duct stump after laparoscopic cholecystectomy].

The aim of this study was to evaluate the length of cystic-duct stumps after laparoscopic cholecystectomy. 113 patients underwent intravenous cholangiography 2 to 3 months postoperatively, whereby a cystic-duct remnant of up to 1 cm was found in 34.5% (n = 39) and between 1 and 2 cm in 36.3% (n = 41). In 24.8% (n = 28) a stump measuring 2 to 3 cm was registered and in 4.4% (n = 5) the cystic-duct remnant was more than 3 cm. Possible consequences with regard to the development of the postcholecystectomy syndrome are discussed. In our experience laparoscopic cholangiography seems to be a useful procedure to detect cysticolithiasis and as preliminary measure to undertaking the correct therapeutic steps. Adherence of this strategy might avoid possible later complications by elimination of their principal cause.

Cholangiography↗
PubMed1992

Aspirin abolishes the decreased low-density lipoprotein (LDL) entry into the rabbit arterial wall induced by the calcium channel blocker isradipine.

After deendothelialization and experimentally induced hypercholesterolemia in rabbits, an increased LDL entry into the vascular wall can be monitored using radiolabelled LDL. In male rabbits aged 6 months the abdominal aortic endothelium was removed by a Fogarty catheter. The animals fed a 1% cholesterol supplemented diet were treated either with isradipine (0.3 mg/kg/daily) (n = 36) alone or in combination with aspirin (5 mg/kg/daily) (n = 36) for four weeks. Thirty-six animals served as controls. 1, 3, 6, 12, 24 and 48 hours prior to sacrificing, 10 microCi 125I-LDL was administered intravenously to six rabbits in each group. The LDL entry was quantified in the abdominal aorta according to morphologically assessed type of surface lining. Aortic cholesterol content was assessed by Sudan-III staining and quantitative determination. Endothelialized segments exhibited a significantly (p less than 0.05 - p less than 0.001) lower LDL uptake as compared to re- or deendothelialized segments. The LDL entry was significantly lower with isradipine treatment than in controls. In parallel the cholesterol content decreased and the Sudan-III-positive areas were smaller in size. This beneficial effect as well as that on aortic lipid content was abolished by a pretreatment with aspirin. While in the isradipine-treated animals PGI2 synthesis was significantly (p less than 0.01) enhanced, it was almost completely blocked by aspirin. These findings indicate that the benefit of reduced LDL entry caused by isradipine may be mediated by an increased endogenous PGI2 synthesis.

Animals↗
PubMed1992

[Laparoscopic cholecystectomy--current status].

Laparoscopic cholecystectomy (LCHE) is a safe and effective way to treat gall stones. The procedure was carried out for the first time in France in 1987 and since then it has spread rapidly all over the world, in view of the excellent results achieved. The major benefits are the low morbidity, the very short hospitalization, the early return to daily life and work and its excellent cosmetic results. LCHE is indicated in symptomatic non-complicated gall-bladder disease. The operative technique is standardized, the complication rate is low. Compared with other treatments such as litholysis, extracorporeal shock wave therapy and standard cholecystectomy it is a superior, definitive alternative, which is prognosed to become the therapy of choice in gallbladder disease.

Adolescent↗
PubMed1988

[Experimental bile duct replacement using deep seromuscular stomach wall grafts].

Numerous materials and experimental designs were tested hitherto concerning their usefulness as a substitute of the ductus choledochus. However, an ideal substitute to discover failed. We had tested a serous muscular stomach wall patch, flapped at the gastroepiploic vasa, in 6 pigs. Choledochus epithelium did not grow in every case. A scarred shrinking with following stenosis of the transplant resulted in all cases with a longer observation period. We concluded from that a serous muscularly flapped stomach wall transplant does not suit as a bile duct substitute.

Animals↗
PubMed1982

[Intralobar pulmonary sequestration].

14 cases of intralobar sequestration of the lung are reviewed. There are 3 different patterns of clinical and radiological symptoms. Angiography is of great value in establishing the diagnosis and defining the anatomic details of the anomalous blood supply, allowing careful planning of the surgical procedure, which was a lower lobectomy in 12 cases. Segmental resections were feasible in 2 cases. No significant complications were observed.

Adolescent↗
PubMed1980

[Carcino-embryonic antigen as screening protein in the follow-up of patients with surgically-treated gastrointestinal cancer (author's transl)].

Carcino-embryonic antigen (CEA) was determined in 206 patients with gastrointestinal cancer (131 colonic and 75 stomach) at the 2nd Department of Surgery of the University of Vienna. The value of CEA in predicting tumour recurrence and/or metastatic spread has been assessed within the framework of regular follow-up control examinations after surgery. A postoperative rise in CEA titre corresponded with cancer recurrence or metastasis both in patients with stomach (91%), as well as colonic cancer (86%), whilst low postoperative CEA values correlated with a negative clinical report only in patients with carcinome of the colon to any degree of accuracy (91%). The correspondence was much lower in patients with stomach cancer (67%).

Carcinoembryonic Antigen↗
PubMed1980

Collagenolytic activity in hyperacute lung allograft rejection.

Six mongrel dogs were presensitized by full thickness skin grafts followed by orthotopic lung homotransplantation. Tissue explants of the hyperacutely rejected lung grafts were placed on the surface of a gel of native collagen. Collagenase activity was found in each specimen. Lungs of 10 untreated dogs served as controls. The collagenolytic system of the transplanted lungs was inhibited by EDTA only. No inhibitory effect was obtained by the inhibitor of bacterial collagenase, cysteine, and normal serum containing protease inhibitors. By means of inhibition studies it was tried to determine the origin of the collagenolytic activity. It is suggested that the enzyme effect is derived from the lysosomes of polymorphonuclear leukocytes. Collagenase of granulocytic origin seems to participate as mediator in the immunological reaction of hyperacute lung graft rejection.

Animals↗
PubMed1979

[Modern functional and physiological techniques in abdominal surgery (author's transl)].

The increasing importance of physiological and functional surgical procedures in the surgical therapy of benign abdominal disease is implied. Positive results were achieved at the 2nd Department of Surgery of the University of Vienna following parietal cell vagotomy in hypersecretory gastroduodenal ulcer, latero-lateral pancreatico-jejunostomy according to Puestov-Mercadier in chronic relapsing pancreatitis, distal splenorenal shunt according to Warren in portal hypertension and following peritoneo-venous shunt according to Warren in portal hypertension and following peritoneo-venous shunt according to Le Veen in ascites and cirrhosis of the liver.

Abdomen↗