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Biomedical subjects

K Kotzampassi

Publications and source records attributed to K Kotzampassi.

At least 19 recordsLinked to original sources
PubMed1992

Gastric mucosal blood flow distribution in the CCl4-induced cirrhotic rat--a model of portal hypertensive gastropathy?

Because the carbon tetrachloride-induced cirrhotic rat model is considered to be the closest to the clinical situation of the cirrhotic patient, the discovery of congestive gastropathy in such rats would enable the development of a useful research model. By the use of laser-Doppler technology, gastric mucosal blood flow was assessed on 14 defined points of the stomach in 16 cirrhotic and 16 matched healthy rats, in an effort at in vivo mapping of the gastric mucosal microcirculation. Our findings of mucosal congestion in the cirrhotic stomach (reduced mucosal blood flow in the gastric corpus) are well matched with the distribution of gastric mucosal blood flow in the cirrhotic patient. These findings suggest that a rat's gastric mucosa could be used for studies of portal hypertensive gastropathy.

Animals↗
PubMed1992

Experimental and clinical evaluation of capsular and parenchymal total liver perfusion. Liver microcirculation.

Liver blood flow measurements obtained from both the liver surface and deep within the parenchyma, were correlated in an effort to assess the usefulness of laser-Doppler flowmetry for non-invasive monitoring of total liver blood flow, the probe being positioned on either the surface or within the liver parenchyma. In 23 Wistar rats and 10 biliary surgery patients, anaesthetized prior to gallbladder removal, liver microcirculation was measured at 4 points on the capsular surface, and consequently at 4 points deep within the parenchyma, using probes connected to a laser-Doppler flowmeter. The findings revealed that laser-Doppler measurements on the liver surface and within the parenchyma were well correlated, as no statistically significant differences were found either in rats or humans. It is concluded that laser-Doppler flowmetry for monitoring of total liver perfusion can be applied either on the capsular surface or within the hepatic parenchyma.

Animals↗
PubMed1992

Gastric mucosal blood flow in portal hypertension patients--a laser Doppler flowmetry study.

Gastric mucosal blood flow was evaluated endoscopically by means of laser Doppler flowmetry in an attempt to explore microcirculatory changes in different areas of gastric mucosa in portal hypertension patients as compared with controls. Twenty male--Child B--cirrhotics and seven healthy subjects were assessed, the recordings being performed at ten defined points of the stomach. Statistical evaluation revealed that blood flow in the body of the stomach was decreased in cirrhotics. Bearing in mind that congestive gastropathy, found mainly in the gastric corpus, is due to changes in gastric vascularity leading to congestion and stasis, we consider that the decrease in gastric mucosal blood flow may be attributable to these vascular alterations.

Gastric Mucosa↗
PubMed1991

Colloidal bismuth subcitrate-induced changes on gastric mucosal hemodynamics in the rat: gastric mucosal blood flow after CBS treatment.

The belief that blood flow plays a central role in cytoprotection and there being no data available, at present, regarding the possible action of Colloidal bismuth subcitrate (CBS-DENOL) on the gastric mucosal blood flow (GMBF), led us to investigate its influence on mucosal hemodynamics in the rat stomach. Measurements of GMBF were performed in 32 male Wistar rats, treated by either CBS or placebo in drinking water for a 3-wk period, by the use of a laser-Doppler flowmeter, at 14 defined points of the stomach. CBS treated animals revealed a highly statistically significant increase (P less than 0.0005, upaired t-test) of GMBF in comparison with the placebo treated. These findings lead us to suggest that CBS exerts its antiulcer action via the mechanism of increased gastric mucosal blood flow. Additionally the increased blood flow may be associated with the previous findings of increased synthesis of prostaglandins, gastric mucus and bicarbonate secretion by CBS.

Animals↗
PubMed1990

Effects of famotidine on gastric mucus of the rat.

The influence of famotidine on the production of gastric mucus was studied at experimental level. We measured the quantity of the intracellular mucus, the surface adherent mucus gel thickness, and the biosynthesis of prostaglandin E2 (PGE2) by the rat gastric mucosa, in pretreated animals. Both the intracellular mucus accumulation and the adherent mucus gel thickness revealed a highly statistically significant increase (P less than 0.0002). PGE2 assay showed that famotidine also led to a statistically significant increase (P = 0.02) of PGE2 in treated versus control animals. These findings raise the question of whether despite its common antisecretory pathway of action this H2-receptor antagonist could play a role in the protection of gastric mucosa. Further research is necessary to determine this.

Animals↗
PubMed1990

The influence of sclerotherapy on gastric mucosal blood flow distribution.

Hemodynamic events and structural vascular changes of the gastric mucosa in cirrhotics have caught the attention of investigators in the recent past, but as yet it is not known whether therapeutic interruption of variceal blood flow at gastroesophageal level alters such portal hypertensive mucosal features. The newly developed endoscopic laser-Doppler technique was used to assess whether variceal eradication by means of endoscopic sclerotherapy influences the gastric mucosal congestion in portal hypertension patients. Gastric mucosal blood flow was determined at ten defined sites of the stomach, before the first session of sclerotherapy and after complete variceal eradication had been achieved in 15 patients. A statistically significant decrease (P less than 0.01 to 0.05) in microcirculation was found at the gastric antrum and corpus, an increase at the pylorus (P less than 0.05), but no change in the fundic area. An important question following these findings is: What are the consequences of such aggravation of gastric congestion on the integrity of the gastric mucosa?

Adult↗
PubMed1990

Early endoscopic fibrin sealing of high-output postoperative enterocutaneous fistulas.

In seven patients with high-volume enterocutaneous fistula following gastric surgery, a new method of treatment was used. Fibrin tissue adhesive was applied transintestinally under endoscopic guidance, in one or multiple sessions, to occlude the anastomotic dehiscence and the perianastomotic cavity. Fistula output diminished rapidly in all cases, and complete closure was endoscopically confirmed. There were no complications related to the method. Because of the simplicity and safety of this procedure compared with the complexity of surgical treatment and the persistently high mortality associated with conservative management, interventional endoscopic approach is suggested as an option for treatment of high-volume alimentary fistula.

Adult↗
PubMed1989

Congestive gastropathy and antral varices: is there an association?

Gastric mucosal lesions are frequently observed during endoscopy in cirrhotics, but only recently has attention been paid to the gastric mucosal vessels themselves as the cause of such lesions. The presence - observed during endoscopy - of areas of erythema outlined by a yellow mosaic-like network, and the existence - ascertained by histology - of focal ectasia of mucosal vessels are termed "congestive gastropathy". In a prospective investigation of this entity, gastric mucosal biopsies have been obtained in 20 portal hypertensive patients with or without signs of congestive gastropathy at their initial sclerotherapy session. During the progress of the study two - Child's C - patients (having negative endoscopic and microscopic findings of congestive gastropathy) exhibited severe lesions of congestive gastropathy at the 2nd and 3rd session, respectively, and further biopsies were therefore obtained. Histologic examination after eosin-hematoxylin and Masson's trichrome staining revealed dilated mucosal vessels. At the 3rd and the 5th sclerotherapy session, respectively, - their esophageal varices having been obliterated - antral varices were prominent. We ascribe the endoscopic changes observed in the gastric mucosa to the alteration of gastric vascularity due to blood flow redistribution, but we pose the question as to whether there is any association between these progressive mucosal alterations and the formation of antral varices.

Adult↗
PubMed1989

Formalin-induced experimental sclerosing cholangitis in the rat.

The few reported cases of sclerosing cholangitis following removal of an echinococcus cyst are thought to be a consequence of the chemical action of formalin used for sterilization of the residual cavity. The aim of this study was to assess this hypothesis. We injected 0.15ml of 2% buffered formalin solution into the central hepatic lobe of five rats, after a midline laparotomy. At 6, 12, 18 and 24 weeks after formalin injection all rats were reoperated upon and a sample of hepatic parenchyma from both the central and the left hepatic lobe was obtained for microscopic evaluation. Our findings, dilatation of portal tracts and bile canaliculi, thickening of the pericanalicular cytoplasm, portal and periportal inflammatory cell infiltration and fibrosis and enlargement of the perisinusoidal space of Disse, suggest that 2% formalin solution leads to the development of essential phenomena of cholestasis and sclerosing cholangitis in the rat, so thus it should be avoided in liver hydatid disease surgery.

Animals↗
PubMed1988

Endoscopic observations of the residual cavity after liver hydatid disease surgery.

Endoscopic inspection of the residual cavity after liver hydatid disease surgery has the potential of determining the cause of delayed cavity obliteration by providing information about the inner surface condition. We therefore performed endoscopy whenever there was an unsatisfactory rate of reduction of the residual cavity size. Over the last 6 years, 72 patients have been operated upon for liver hydatid disease. Of these, 42 had wide-bore catheter drainage of the echinococcal cavity and 30 had primary surgical closure. In 17 of 42 patients, endoscopy was performed 3-14 months postoperatively, because the cavity showed no evidence of reduction in size. A flexible choledochoscope was passed through the transcutaneous drainage fistula. Silk sutures were found four times and residual parasitic elements were found 3 times. These were all removed. In 13 patients, the cavity was inspected within 6 months postoperatively; their inner cavity surfaces were covered with white soft areolar tissue. The other 4 patients' cavities were examined within 6-14 months; hard fibrous connective tissue was found. Two patients required reoperation, and in both cases the cavity collapsed within 3-12 months postoperatively. We conclude, that endoscopy of the residual cavity is a useful procedure for both recognition and removal of the cause of delay in the cavity obliteration and can lead to collapse of the cavity.

Echinococcosis, Hepatic↗
PubMed1988

Common bile-duct mucosa in choledochoduodenostomy patients--histological and histochemical study.

We describe the histological and histochemical changes of the common bile-duct mucosa in specimens obtained by means of peroral cholangioscopy, 1-12 years after choledochoduodenal anastomosis. Our findings--hyperplasia of the superficial epithelium, metaplastic goblet cells containing predominantly acid sialomucins, and pyloric-like gland formation containing neutral mucins--express a morphological and functional differentiation of the common bile-duct mucosa that probably facilitates its survival in a different environment. We consider that these adaptive changes may explain the uneventful long-term postoperative period of choledochoduodenostomized patients.

Choledochostomy↗
PubMed1988

Ultrastructural changes of the renal cortex after septic shock in rats.

The purpose of this study was to observe the ultrastructural changes of the renal cortex that occur in septic shock. Twenty male Wistar rats were used. They were divided into 4 groups of five animals each one. A septic shock was caused by intraperitoneal injection of 5 x 10(6) living E. Coli, in a dose of 2ml/100gr B. W., in four rats of each group. The fifth rat of each group was used as control, and was injected by an equal volume of normal saline. A small segment from the right kidney was excised from every rat of each group, respectively 1, 2, 4 and 6 hours after the onset of the shock. Morphologically, alterations of the endothelium of the peritubular and glomerular capillaries were found. The endothelial layer was thick with many cytoplasmic folds. In the glomeruli, the basal lamina as well as the overlying epithelial podocytes and their foot processes were swollen. The urinary space contained erythrocytes and cell debris. Lesions of the proximal and distal tubule epithelium were also observed. The basal infoldings of the cell membrane disappeared in many epithelial cells of the proximal tubule and the brush border showed varying degrees of disruption. Within the tubular lumen much cellular debris was found. The epithelium of the distal tubule was thinner in some portions and in others it was swollen. The lesions were focal during the first hour after the onset of shock, while at the fourth and sixth hours they were most extensive. In conclusion, the ultrastructural findings after septic shock were non-specific and indicated cellular injury.

Animals↗
PubMed1987

Choledochoscopy in intrabiliary rupture of hydatid cyst of the liver.

From 1981-1985, 62 patients have been operated upon for hydatid disease of the liver. Nine patients presented with hepatic colic, chill and fever; seven cases also showed obstructive jaundice, as their cysts had ruptured into the biliary tree. A large communication between the pericyst cavity and the bile ducts was confirmed at operation. The common bile duct was explored in all nine patients and laminated membranes and daughter cysts were found in three cases. Following this, choledochoscopy was performed. Retained membranes and a stone were revealed in one of these three patients. In two other cases from the remaining six negative explorations, laminated membranes were also found. We therefore recommend choledochoscopy not only in biliary lithiasis, but in every case of intrabiliary rupture of a hydatid cyst of the liver.

Adult↗