Biomedical subjects

K Kotzampassi

Publications and source records attributed to K Kotzampassi.

42 records · Page 3Linked to original sources

PubMedDate not supplied

Hemodynamic events in the peritoneal environment during pneumoperitoneum in dogs.

The purpose of this experimental study was to determine the hemodynamic conditions of intraperitoneal viscera during pneumoperitoneum by using either CO2 gas or helium (He) for insufflation. In 16 mongrel dogs (divided into a CO2 group and an He group) subjected to 14 mmHg pneumoperitoneum for 60 min, the following parameters were assessed at times before and 1, 2, 5, 15, 30, 45, and 60 min thereafter: (1) intestinal mucosal blood flow, by means of a laser-Doppler probe inplanted into a jejunal loop; (2) portal pressure and portal blood pCO2, through a catheter inserted via a mesenteric jejunal vein; (3) intramural jejunal pH (pHi), by means of a Tonometer, which expresses the degree of tissue ischemia; (4) inferior vena cava pressure and blood pCO2, through a catheter inserted via a femoral vein; and (5) from the systemic circulation pulse rate, arterial blood pressure, CO, CVP, PVP, SaO2, pCO2, and paO2 were measured through a catheter placed into a femoral artery and a Swan-Ganz thermodilution catheter inserted via external jugular vein: CI and SVR were then calculated. Jejunal mucosal blood flow was found decreased (P < 0.0001) and pHi revealed gut mucosal ischemia. Portal and inferior vena cava pressures were found to be elevated (P < 0.0001), as was blood pCO2 of these vessels (P < 0.001), in only the CO2 group. From the systemic circulation, arterial blood pressure, CO, CI, SaO2, and paO2 revealed a decrease (P < 0.001) while arterial pCO2 (only CO2 group), CVP, SVR, and PVP revealed an increase (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

The 'mosaic-like' pattern of portal hypertensive gastric mucosa after variceal eradication by sclerotherapy.

The 'mosaic-like' pattern of portal hypertensive gastric mucosa has been evaluated endoscopically in 38 patients referred for elective sclerotherapy, before the first session, after the complete eradication of varices and six months later. Of 38 patients studied, 18 patients exhibited mild, and 20 patients exhibited negative, findings of congestive gastropathy prior to sclerotherapy. Seventeen and 18 patients, respectively, developed aggravated changes of congestive gastropathy after the completion of sclerotherapy (P = 0.003). We consider that obliteration of varices by means of endoscopic sclerotherapy influences the development of gastric congestion changes in the majority of patients. However, further studies are required to relate the direction of blood flow in the portal system as well as the level of portal pressure with the congestive gastropathy findings in such patients.

Esophageal and Gastric Varices↗

PubMedDate not supplied

The implication of nitric oxide in the process of bacterial translocation.

Since there is increasing evidence indicating nitric oxide [NO] would play a role in sepsis, we decided to investigate whether this multifaceted mediator is directly implicated in the process of bacterial translocation. A total of 48 rats received intraperitoneal either Zymosan A (group Z) for systemic inflammation production or sodium chloride solution (controls); they were then further subdivided into three groups of eight animals each, being given, through the tail vein: L-NAME (N-nitro-L-arginine] for inhibition of NO production; SNP (sodium nitroprusside) as NO donor; or sodium chloride as control. After 2 h, the mesenteric lymph node complex was excised, under sterile conditions, and, using standard bacteriological techniques, bacterial translocation was assessed as colony forming units per gram of tissue (CFU/g). Statistical evaluation of the bacteriological data revealed a significant increase of bacterial translocation in all rats subjected to systemic inflammation (group Z) versus controls (P = 0.01) Control rats that were subjected to L-NAME treatment exhibited a statistically significant increase (P = 0.001) in CFU/g compared to sodium chloride treated rats, while SNP treatment revealed no difference in relation to sodium chloride treated rats. Group Z rats, subjected to L-NAME treatment, similarly exhibited a statistically significant increase (P = 0.01) in CFU/g compared to sodium chloride treated rats, while SNP treatment led to a statistical increase of bacterial translocation in relation to sodium chloride treated rats (P = 0.05). The results of this study lead us to suggest that NO appears to participate in the process of bacterial translocation.

Animals↗

PubMedDate not supplied

Long-term results after esophagoplasty with colon. An endoscopic study.

Eight patients from a series of 13 having esophageal resection and colon interposition for benign disease have been evaluated by endoscopic testing, with special emphasis on the mucosal long-term changes of the colon segment and their histologic documentation. The average follow-up period was 7.2 years. All patients were in a satisfactory nutritional state but described problems associated with eating, such as regurgitation of undigested foods and substernal postprandial heartburn. No stricture was present but endoscopy confirmed the existence of food in the haustra. There was no gross evidence of colitis but the histological evaluation revealed inflammatory cell infiltration or fibrosis in all patients but one. It is believed that the main cause of mucosal damage is the prolonged cascading of food and delayed emptying, leading to digestion in the haustra.

Colon↗

PubMedDate not supplied

Hepatic tissue microcirculation, oxygenation and energy charge in ischemia-reperfusion subjected cirrhotic rat liver.

BACKGROUND/AIMS: The hemodynamic disturbances in the cirrhotic liver following severe variceal bleeding and subsequent restoration by blood transfusion is an ischemia/reperfusion injury event which represents the clinical situation of liver dysfunction. Therefore, the aim of this study was to evaluate the microcirculation, oxygenation and energy charge of the cirrhotic rat liver after ischemia/reperfusion. METHODOLOGY: In eight carbon tetrachloride-induced cirrhotic rats and an equal number of controls subjected to 30 minutes of ischemia and 60 minutes of reperfusion by hepatoduodenal ligament clamping, the following parameters were assessed: hepatic microcirculation by laser-Doppler fluxmetry, hepatic tissue oxygenation by a Clark-type electrode, hepatic energy charge by tissue sampling and adenine-nucleotides determination by means of high-performance liquid chromatography. RESULTS: At baseline, liver microcirculation was found to be significantly decreased in the cirrhotics versus controls groups. Ischemia led to a reduction in both groups, while reperfusion improved microcirculation, but not to the baseline level. Oxygenation was reduced during ischemia and restored after reperfusion in both groups. Hepatic energy charge was reduced in the cirrhotics versus controls at baseline, and significantly decreased during ischemia in both groups. At reperfusion, a further reduction was found in the cirrhotic group, while in the control group it was restored to baseline. CONCLUSION: Hepatic microcirculation, oxygenation and energy charge are subjected to different degrees of diminution after ischemia/reperfusion in the cirrhotic rat liver.

Adenine Nucleotides↗

PubMedDate not supplied

24-hr measurement of gastric mucosal perfusion in conscious humans.

BACKGROUND/AIMS: Gastric mucosal blood flow estimation in humans is obtained through an endoscope and the time of measurement lasts only a few minutes. Thinking that long-term monitoring of mucosal perfusion would be a significant contribution to the study of gastric physiology, we registered gastric mucosal blood flow continuously for 24 hours, using single fiber laser-Doppler technology. METHODOLOGY: The study was undertaken in 16 healthy subjects (8 of them had their gastric acidity inhibited with a proton pump inhibitor) and in 8 patients with an endoscopically proven, active duodenal ulcer. A 140 cm-long single fiber laser-Doppler microprobe was positioned through a gastrointestinal tube in the middle of the gastric corpus and the mucosal microcirculation was monitored from 14.00 h until 13.59 h the following day. Data were stored and processed to evaluate the probable circadian rhythms, using maximum entropy spectrum analysis. RESULTS: We found that the daily variations of gastric mucosal perfusion follow a circadian rhythm. The respective patterns with maximum and minimum values were: healthy controls, maximum at 02.00, 10.00, 18.00 h and minimum at 5.30, 14.00 and 22.00 h. Healthy controls treated by a proton pump inhibitor, maximum at 02.00, 07.00, 18.00 h and minimum at 04.00, 12.00 and 22.00 h. Ulcer patients, maximum 07.00 and 21.00 h and minimum at 17.00 and 24.00 h. CONCLUSIONS: It is concluded that long-term measurement of gastric mucosal blood flow in conscious humans is feasible and that this factor of gastric physiology follows a concrete circadian rhythm, which is not particularly influenced by acid inhibition, but is completely distorted in ulcer patients.

Adult↗