Biomedical subjects

A Avgerinos

Publications and source records attributed to A Avgerinos.

46 records · Page 3Linked to original sources

PubMed1984

Bowel preparation and the risk of explosion during colonoscopic polypectomy.

Concentration of oxygen, methane, and hydrogen were measured in intracolonic gas samples aspirated through the colonoscope at the time of colonoscopy from 46 patients. Of the above patients 20 prepared either with mannitol (n = 10) or with castor oil (n = 10) had the instrument passed to the caecum without air insufflation or suction. After mannitol, mean intracolonic hydrogen concentration (4.07%) was significantly higher (p less than 0.001) than after castor oil (0.51%). Mean oxygen and methane concentrations were approximately similar. Potentially explosive concentrations of hydrogen (greater than 4.1%) and or methane (greater than 5%) were present in 6/10 patients given mannitol and 2/10 patients given castor oil. Nevertheless only one patient from each group had coexisting oxygen concentrations of more than 5% producing thus a combustile mixture. Routine colonoscopy (using air insufflation and suction) was performed in 26 patients prepared with mannitol. Mean intracolonic hydrogen and methane was 0.63% and 0.88% respectively. The highest recorded concentration of hydrogen was 2.6%, and of methane 2.1%, while all patients had oxygen concentrations of more than 5%. It is suggested, therefore, that routine insufflation and suction before colonoscopic electrosurgical polypectomy should result in safe levels of these gases. The remote possibility of pockets of undiluted gas in explosive concentration, however, indicates the use of an inert gas such as carbon dioxide if mannitol preparation is used before electrosurgery.

Adult↗

PubMed1984

Plasma alpha-lipoprotein pattern and LCAT activity in acute viral hepatitis in children.

The alpha-lipoprotein (a-Lp) electrophoretic pattern on agarose gel was studied serially in 65 children with acute viral hepatitis. In seven cases the high-density lipoprotein fractions (HDL) were also separated by ultracentrifugation and studied in relation to lecithin: cholesterol acyltransferase activity (LCAT) during the acute phase and recovery. The a-Lp band was initially absent on electrophoresis in 36 cases and never appeared in 3 of the children who died. In those who survived a-Lp reappeared with clinical improvement even before a definite increase in S-ASAT and bilirubin was evident. In the seven children in whom it was measured LCAT activity ranged during the acute phase from 17.4 to 57 nmol h-1 ml-1. In patients with initially 'normal' LCAT activity (group I, no. = 3) HDL was normal both in amount and composition. In patients with 'low' LCAT (group II, no. = 4) HDL was reduced and of abnormal composition. In both groups the a-Lp band was absent or considerably reduced on electrophoresis. In the latter group LCAT activity increased significantly on recovery, as did the amount of HDL which became normal in composition. These results suggest that in acute viral hepatitis in children changes in composition and concentration of HDL depend on the degree of hepatic functional disturbance, as judged by plasma LCAT activity. Nevertheless, it appears that HDL electrophoretic behaviour may be abnormal during the early stage of the disease while plasma LCAT activity is not significantly affected.

Acute Disease↗

PubMed1982

Plasma lipoprotein pattern in relation to liver histology after toxic hepatitis and experimental biliary obstruction in rabbits.

Plasma lipoproteins were studied in relation to liver histology in rabbits in the course of toxic hepatitis and compared to those after experimental biliary obstruction. The lipoprotein electrophoretic pattern became deeply abnormal during the acute phase of toxic hepatitis and correlated with the degree of liver injury, improving during recovery. Liver damage was more severe after carbon tetrachloride than after alcohol and milder after allylo-isopropyl-acetamide, a porphyrinogenic substance. Lipoprotein abnormalities were not followed by significantly reduced levels of cholesterol esters in the plasma. In comparison, animals with biliary obstruction developed milder liver damage presented gross abnormalities of plasma lipids and lipoproteins, followed by relative deficiency of cholesterol esterification. It is concluded that lipoprotein changes in acute liver injury, although non-specific, are a sensitive index of liver damage and recovery. Serious acute liver injury can exist without significant fall in cholesterol esters.

Alanine Transaminase↗

PubMed1981

Potentially explosive colonic concentrations of hydrogen after bowel preparation with mannitol.

Hydrogen (H2) concentrations were measured in undiluted samples of intracolonic gas and in expired air in twenty patients undergoing colonoscopy after preparation with either mannitol or castor oil. Potentially explosive intracolonic H2 concentrations were present in six out of ten patients given mannitol, but in none given castor oil. This has important implications for colonoscopic, as well as for surgical, electrosurgery. H2 concentrations in expired air sampled preoperatively did not identify patients with potentially explosive intracolonic hydrogen levels.

Adult↗

PubMed1981

Investigations on the penetration of ranitidine into the cerebrospinal fluid and a comparison of the effects of ranitidine and cimetidine on male sex hormones.

Cerebrospinal fluid (CSF) ranitidine concentrations were measured in 13 normal subjects undergoing routine myelography following either one, or two doses ranitidine 200 mg. Small amounts of the drug were detectable in the CSF. A separate investigation of duodenal ulcer patients compared the effects of ranitidine 150 mg twice-daily and cimetidine 1 g daily on basal and stimulated levels of male reproductive hormones in the plasma. Although cimetidine treatment resulted in a small rise in basal and stimulated testosterone, neither drug was associated with significant changes in basal or stimulated hormone levels.

Adult↗

PubMed1977

Abnormal lipoproteins in multiple myelomatosis.

In a study of the lipoprotein pattern in multiple myelomatosis electrophoresis on agarose gel showed abnormal lipoproteins, named paralipoproteins (p-Lp), in 24 out of 30 normolipidaemic patients. These paralipoproteins were grouped according to their mobility into one or another of the following types: (1) p-Lp1 with a mobility identical with that of gamma-globulin, (2) p-Lp2 with a mobility between that of beta- and gamma-globulin, (3) p-Lp3 with a mobility identical with that of beta-globulin. On ultracentrifugation the abnormal lipoproteins were found to have a density above 1-063 g/ml.

Aged↗

PubMedDate not supplied

Plasma lipid and lipoprotein response to fat feeding in alcoholic liver disease.

Serum lipids and lipoproteins were analyzed after an overnight fast, and following a fatty meal in 10 patients with cirrhosis, 5 with fatty liver, and 5 normal subjects. Cirrhotic patients were divided into two groups of five on the basis of serum lecithin-cholesterol acyltransferase activity. Fasting triglyceride levels were similar in all four groups. In all but cirrhotic patients with low lecithin-cholesterol acyltransferase activity, most fasting triglyceride was found in very low density lipoproteins; in the latter group, most of it was found in low density lipoproteins. We confirmed that patients with fatty liver have a higher serum triglyceride response to fat feeding than normal subjects, but we did not find higher levels in cirrhotic patients. Cirrhotic patients with "normal" lecithin-cholesterol acyltransferase activity had a normal triglyceride response to dietary fat. In patients with cirrhosis and low lecithin-cholesterol acyltransferase activity, the increase in triglyceride was less than in normal subjects. In this group, most of the extra triglyceride was carried in low density lipoprotein, and not in chylomicrons and very low density lipoprotein, as in the other groups.

Adult↗

PubMedDate not supplied

Determination of lansoprazole in biological fluids and pharmaceutical dosage by HPLC.

A simple and rapid (extractionless) high-performance liquid chromatographic method with UV detection at 230 nm was developed for the determination of lansoprazole in biological fluids and pharmaceutical dosage. Niflumic acid was added as internal standard. The separation was performed at ambient temperature on a C18 Spherisorb column with acetonitrile + 0.1 M sodium acetate (40:60, v/v, pH 7) as mobile phase. The retention time was 5.2 min for niflumic acid and 6.7 min for lansoprazole. The detection limit was 20 ng/ml using a 100 microl loop. The method was successfully applied to a pharmacokinetic study of lansoprazole in humans.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMedDate not supplied

Pharmacokinetics of nifedipine derived from a new retard tablet formulation.

A nifedipine retard tablet formation (Glopir, 20mg) was developed to reduce the number of daily doses required in the treatment of hypertension. The plasma pharmacokinetics of this oral formulation were examined, in a single study, on 12 healthy volunteers. Single 20 mg doses of nifedipine retard tablet (Glopir, GAP & Co. Athens, Greece) were given after an overnight fast and 10 blood samples were drawn during the first 24 h after administration. Plasma concentrations of nifedipine were measured by high performance liquid chromatography. The mean peak plasma nifedipine concentration was 27.6 ng/ml at a maximum time of 24 h, after tablet ingestion. The mean apparent nifedipine elimination half-life was 16.0 +/- 7.5 h and the mean area under the plasma concentration time curve (0-24 h) 404.1 +/- 134.0 ng/ml.h. The data suggest that the tablet form has properties of a sustained-release preparation, with slow accumulation and elimination phases and can appropriately be given in a twice-daily regimen.

Administration, Oral↗

PubMedDate not supplied

Diffuse idiopathic colonic varices presenting with lower gastrointestinal bleeding in an elderly patient: a case report and review of the literature.

We report a case of lower gastrointestinal bleeding caused by idiopathic colonic varices. A 74-year-old woman presented with rectal bleeding. Colonoscopy revealed numerous varices of the entire colon, which, after an extensive work-up, proved to be idiopathic. No specific therapy or transfusions were required and there has been no further bleeding to date (follow-up 10 months). Review of the literature demonstrates that diffuse idiopathic colonic varices are a rare cause of lower gastrointestinal bleeding, especially as the first presentation in an elderly patient.

Aged↗