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Biomedical subjects

O Leiss

Publications and source records attributed to O Leiss.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Traveler's diarrhea. Incidence--pathogens--pathophysiology--clinical aspects--prevention and therapy].

About one-third of travellers will be affected by travellers' diarrhoea. Regions with low risk are Northern Europe, the United States, Australia and New Zealand. Intermediate risk is found in Southern Europe, most islands of the Caribbean, Japan, Israel and Southern Africa and high risk in developing countries. Among the most commonly isolated pathogens are enterotoxigenic E. coli, Salmonella, Shigella, Campylobacter, G. lamblia, E. histolytica and viruses. The individual risk depends on the age and constitution of the traveller, on styles of travel and on previous expositure in developing countries. Travellers' diarrhoea is usually a short self-limited disease for 2-5 days. Nutritional prophylaxis along the principle "boil it, cook it, peel it, or forget it" is useful. Prophylaxis with non-antibiotic drugs is only justified in special cases.

Bacteria↗
PubMed1990

[Hygienic measures in endoscopy].

Risks of infection associated with endoscopy, sources of infection, relevant microorganisms (P. aeruginosa, Serratia, HIV, HB, Cryptosporidiosis), disinfection procedures and the steps of disinfection procedures and reasons for failing of disinfection procedures are discussed. Channel systems and rinsing solutions are relevant but until today underestimated sources of infection. In detail the contamination of the channel system in endoscopes, problems of good disinfection and the significance of mechanical cleaning are described. In cases of Pseudomonas aeruginosa infections after endoscopy an immediate investigation of the contamination of the endoscope and of rinsing solutions is necessary. Automatic disinfection systems are requested, because with such systems a higher security for patient and personal is achievable. A regular control of the efficacy of the disinfection process by a competent Hygiene-Institute is recommended.

Cross Infection↗
PubMed1989

Biliary lipid composition in patients with cystic fibrosis.

Lipid composition of gallbladder bile was determined in 20 patients with cystic fibrosis (CF) (9 females and 11 males, ranging in age from 3 to 18 years). The results were compared with 47 normal subjects matched for age, sex, and pubertal stage. In patients with CF, bile was undersaturated with cholesterol before puberty in both sexes and no differences with normal controls could be observed. After puberty, a similar increase in cholesterol saturation was noted in females with CF (85 +/- 15% vs. 130 +/- 38%, p less than 0.01) and normal controls (82 +/- 11% vs. 138 +/- 31%, p less than 0.01). No change in cholesterol saturation could be observed in male patients and controls after puberty. Molar percentage of chenodeoxycholic acid (CDCA) was lower (p less than 0.05) in postpubertal females (31 +/- 9%) and males (36 +/- 7%) with CF compared to controls (42 +/- 8% and 40 +/- 5%, respectively), while cholic acid (CA) was higher in all patients with CF. In females with CF, lithocholic acid (LCA) increased after puberty (2.2 +/- 0.8% vs. 5.3 +/- 2.6%, p less than 0.05) and was higher compared to controls (2.2 +/- 0.8%, p less than 0.001). An increase was also noted for deoxycholic acid (DCA) in postpubertal females with CF (1.7 +/- 2.6% vs. 10.8 +/- 7%, p less than 0.05), but it was lower in both sexes after puberty than in respective controls. The present results suggest that cholesterol saturation of bile in patients with CF is not different from respective controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Administration of a terpene mixture inhibits cholesterol nucleation in bile from patients with cholesterol gallstones.

Patients with cholesterol gallstones referred to elective cholecystectomy were randomly assigned prior to operation to no treatment (n = 14), treatment with one capsule t.d.s. (n = 12) or two capsules t.d.s. (n = 11) of a terpene mixture (Rowachol). Patients with pigment stones (n = 7) or no biliary tract disease (n = 5) were also studied. Lipid composition, presence of cholesterol monohydrate crystals, and nucleation time were determined in gallbladder bile aspirated during surgery. Cholesterol saturation was similar in the different groups. Crystals were present in all cholesterol gallstone patients without treatment and in none of the controls. In one of the patients treated with one capsule and four of the patients treated with two capsules crystals could not be detected. The terpenes prolonged nucleation time from 2.8 to 5.8 days (one capsule; P less than 0.05) and to 9.5 days (two capsules; P less than 0.001), respectively; but nucleation did not occur in seven controls. Although the mechanism by which the terpene mixture inhibits the formation of cholesterol crystals in bile was not determined, the findings suggest that the terpene mixture might be a useful agent for a clinical trial to test whether they will prevent recurrence of gallstones after medical dissolution.

Bile↗
PubMed1987

Increased prevalence of apolipoprotein E2 in patients with retinitis pigmentosa.

Apolipoprotein E isoforms were determined in 139 unrelated patients with retinitis pigmentosa (RP). When compared to prevalence rates for the general population in Germany, an increased prevalence was observed for phenotypes E2/E2: 10.1 vs. 1.0% (p less than 0.001), E2/E3: 19.4 vs. 12.0% (p less than 0.05), and E2/E4: 5.8 vs. 1.5% (n.s.), while the prevalence appeared to be reduced for phenotypes E3/E3: 48.9 vs. 59.8% (n.s.) E3/E4: 13.7 vs. 22.9% (p less than 0.05), and E4/E4: 2.2 vs. 2.8% (n.s.). These findings suggest that genetically determined abnormalities of plasma lipoprotein metabolism may be associated with some forms of RP.

Apolipoprotein E2↗
PubMed1986

Effect of low-dose sitostanol on serum cholesterol in patients with hypercholesterolemia.

Sitostanol (24-ethyl-5 alpha-cholestan-3 beta-ol), a hydrogenated derivative of sitosterol, was administered in a low dose (1.5 g/day) for 4 weeks to 6 patients with hypercholesterolemia. Total cholesterol was reduced significantly after 3 and 4 weeks by 10 and 15%, respectively. The reduction of total cholesterol was entirely due to a fall in LDL cholesterol. Total triglycerides and HDL cholesterol were not altered. Two weeks after cessation of sitostanol administration serum cholesterol returned to pretreatment levels. No significant amounts of sitostanol could be detected in plasma during therapy. These results suggest that low-dose sitostanol might be a useful hypolipidemic agent for the treatment of mild hypercholesterolemia.

Adult↗
PubMed1986

Effect of gemfibrozil on lipids, apoproteins, and postheparin lipolytic activities in normolipidemic subjects.

The lipid lowering agent Gemfibrozil was tested in 8 normolipidemic subjects during a three-month intake. Plasma triglycerides decreased by 41% and Very Low Density Lipoprotein (VLDL) triglycerides decreased by 54%. The reduction of plasma cholesterol, less marked (by 10%), was due to a decrease of Low Density Lipoprotein by 20% while High Density Lipoprotein (HDL) increased up to 30%. The separation of HDL demonstrated that only HDL3 were increased. The determination of the apoproteins in plasma and lipoprotein fractions showed similar results with a decrease of apo B (by 20%) and an increase of apo A-I and apo A-II, mainly in the HDL3 fraction. Plasma postheparin lipolytic activities (PHLA) were not influenced by the therapy and no correlation was found between these activities and any of the plasma or lipoprotein lipids. The apo C-III/apo C-II ratio in VLDL decreased by 30%; however, no correlation was found between this ratio in plasma as well as VLDL and triglycerides. In addition, the Intra Venous Fat Tolerance Test did not demonstrate any improvement of the clearance of exogenous fat. The lipid lowering efficacy of Gemfibrozil, its collateral effects, and the possible mechanisms of action are discussed.

Adult↗
PubMed1986

Biliary cholesterol saturation in non-obese women and non-obese men before and after puberty.

The lipid composition of gallbladder bile was determined in forty-seven normal, non-obese subjects (twenty females and twenty-seven males) without gallstones ranging in age from seven months to twenty-nine years. Before puberty, bile was undersaturated with cholesterol in both sexes to the same extent. After puberty a marked increase in cholesterol saturation was observed in females but not in males (138% vs 88%; P less than 0.01). A significant correlation between age and cholesterol saturation could be observed in females (r = 0.546; P less than 0.05) but not in males. In addition a significant correlation between absolute weight and cholesterol saturation in all females (r = 0.827; P less than 0.001) and those after puberty (r = 0.659; P less than 0.05) could be demonstrated. In neither sex was saturation related to body mass index or ideal body weight. These findings suggest that saturation of bile raises in women during puberty but not in men, and this sex-related difference in cholesterol saturation probably contributes to the more common occurrence of gallstones in women than in men.

Adolescent↗
PubMed1986

Identification of metabolic risk factors for posterior subcapsular cataract.

To determine the possible role of glucose and lipid metabolism in the formation of cataract in elderly people we studied 463 patients undergoing cataract extraction. Of 188 males, 35 (19%) had posterior subcapsular cataract (group 1), 27 (14%) had cortical cataract (group 2), and 24 (13%) had nuclear cataract (group 3). Of 275 females, 27 (10%) belonged to group 1, 44 (16%) to group 2, and 33 (12%) to group 3. Patients in group 1 were significantly younger than those of group 2 and 3. In addition, patients in group 1 had higher concentrations of fasting serum triglycerides than patients of group 2 or 3. No difference in mean concentrations of serum cholesterol was observed between the different groups. However, fasting plasma glucose concentrations were higher in group 1 patients than in those of group 2 or 3. Patients in group 1 had a higher 'Broca index' than those in group 2 or 3, with the exception of males in group 3. These results suggest that the association of hypertriglyceridemia, hyperglycemia and obesity favors the formation of a specific morphologic type of lens opacity, posterior subcapsular cataract, occurring at an early age. They imply the possibility of effective modes of preventive therapy for a subgroup of patients with 'senile' cataract.

Aged↗
PubMed1986

Biliary lipid secretion in patients with heterozygous familial hypercholesterolemia and combined hyperlipidemia. Influence of bezafibrate and fenofibrate.

Serum and biliary lipid metabolism were examined in 13 patients with different types of hyperlipoproteinemia before and after 4 weeks of treatment with either bezafibrate or fenofibrate. In patients with heterozygous familial hypercholesterolemia (FH), bezafibrate (n = 5) and fenofibrate (n = 7) produced a similar significant reduction of total cholesterol, LDL-cholesterol, and triglycerides by 21, 23, and 32%, respectively. In patients with familial combined hyperlipidemia (CHL), only triglycerides decreased markedly. Biliary lipid secretion rates in patients with heterozygous FH were not different from those of young male volunteers, indicating that a reduction of hepatic LDL receptors did not affect hepatic elimination of cholesterol or bile acids. Biliary cholesterol secretion increased significantly from 57 to 75 mg/hr during bezafibrate therapy (n = 8) and from 62 to 71 mg/hr during fenofibrate therapy (n = 9). No consistent change in bile acid or phospholipid secretion was observed. The elevated output of biliary cholesterol increased cholesterol saturation significantly from 147 to 185% and from 152 to 173% during administration of bezafibrate and fenofibrate, respectively. The present study indicates that treatment with bezafibrate or fenofibrate is effective in lowering LDL cholesterol in patients with heterozygous FH, but both drugs increase cholesterol saturation of bile, which might enhance the risk of cholesterol gallstone formation.

Adult↗
PubMed1985

Comparison of biliary lipid secretion in non-obese cholesterol gallstone patients with normal, young, male volunteers.

Measurements of biliary lipid secretion rates were performed in 14 non-obese patients with radiolucent gallstones (9 females, 5 males; mean age 48 years; mean body weight 65 kg) and in 14 healthy male volunteers (mean age 26 years, mean body weight 74 kg). The results in the gallstone patients differ in several respect from those obtained in the volunteers. Molar percentage of cholesterol was higher (5.8 versus 5.0 mol%; P less than 0.05) and molar percentage of bile acids lower (73.8 versus 76.9 mol%; P less than 0.05) in the gallstone patients. However, these changes were not followed by notable differences in cholesterol saturation of bile (94% vs 88%). Generally, hepatic secretion rates of cholesterol were significantly elevated in the gallstone patients (55 vs 46 mg/h; P less than 0.05) whereas outputs of bile acids and phospholipids did not differ between the two groups. Although patients with cholesterol gallstones tended to have a lower percentage of chenodeoxycholic acid (38 versus 42 mol%) and increased deoxycholic acid (23 versus 16 mol%) in their bile, these differences were not significant. Nevertheless, in patients with cholesterol gallstones a significant positive correlation between deoxycholic acid secretion and cholesterol output was observed. For the whole group of patients and volunteers a positive correlation between age and cholesterol secretion could be demonstrated. The higher hepatic cholesterol secretion in gallstone patients seems not be due to differences in body weight, but rather to the older age of the patients. These results suggest that age itself or age-related changes in deoxycholic acid metabolism contributes to biliary cholesterol output in non-obese patients with cholesterol gallstones.

Adult↗
PubMed1985

Serum-cholesterol-lowering effect of metronidazole and possible mechanisms of action.

In five patients with Crohn's disease long-term therapy with metronidazole (400 mg b.i.d.) was followed by a significant reduction of total serum cholesterol from 179 mg/dl to 156 mg/dl, 134 mg/dl, and 143 mg/dl, after 2-4 months, 6 months, and 9-12 months, respectively. Lipoprotein analysis before and after 3 weeks of administration of metronidazole (400 mg/day) to five normolipemic volunteers revealed that LDL-cholesterol was reduced by 21% (P less than 0.05), whereas HDL-cholesterol remained unchanged. Biliary secretion of cholesterol and bile acids were reduced by 13% and 20% (P less than 0.05), respectively, which might suggest a decreased sterol synthesis. The amount and percentage of intestinal cholesterol absorption were decreased by 33% and 22% (P less than 0.05). Thus, a possible decrease in sterol synthesis and a reduction of cholesterol absorption might be responsible for the serum-cholesterol-lowering effect of metronidazole. However, caution should be taken when considering metronidazole for long-term treatment of patients with hypercholesterolemia due to possible side effects.

Bile↗
PubMed1985

Effect of gemfibrozil on biliary lipid metabolism in normolipemic subjects.

The mechanisms of the lipid-lowering agent gemfibrozil on biliary lipid metabolism were studied in eight normolipemic male volunteers. These measurements were performed before and after 3 months of administration. During administration of gemfibrozil, plasma cholesterol decreased by 19% (P less than 0.01) and triglycerides by 46% (P less than 0.01), and HDL cholesterol increased by 10% (P less than 0.01). The lithogenic index in gallbladder bile increased from 0.73 to 1.37 (P less than 0.05) and in hepatic bile from 0.86 to 1.42 (P less than 0.01). The increase in lithogenicity of gallbladder bile and hepatic bile was due to an increased biliary output of cholesterol from 47 to 70 mg/h (P less than 0.01) and a decreased output of bile acids from 943 to 694 mg/hr (P less than 0.01), whereas phospholipid output was not altered. The reduction in bile acid output was a result of a significant decrease in chenodeoxycholic acid secretion (r = 0.852; P less than 0.01). Cholic acid output was not affected by gemfibrozil. These results suggest that administration of gemfibrozil enhances the possible risk of gallstone formation like clofibrate.

Adult↗
PubMed1985

Effect of Rowachol on biliary lipid secretion and serum lipids in normal volunteers.

The effect of Rowachol (200 mg tid), an essential oil preparation, on biliary lipid secretion and serum lipids was measured in six healthy male volunteers before and after four weeks of treatment. Biliary cholesterol and phospholipid secretion increased significantly from 113 +/- 36 (SD) mumol/h to 155 +/- 52 mumol/h (p less than 0.05) and from 409 +/- 145 mumol/h to 587 +/- 185 mumol/h (p less than 0.05), respectively. Bile acid secretion increased from 1519 +/- 662 mumol/h to 2287 +/- 1175 mumol/h (p greater than 0.05 and greater than 0.10). This marked increase in biliary lipid secretion was not followed by a change in molar composition of biliary lipids and lithogenicity of bile. Serum cholesterol and triglycerides declined from 4.9 mmol/l to 4.1 mmol/l (p less than 0.05) and from 1.2 mmol/l to 0.9 mmol/l (p less than 0.05) respectively. The ratio of high-density-lipoprotein cholesterol to total cholesterol increased from 0.22 to 0.31 (p less than 0.05). Although it has been shown previously that Rowachol could dissolve cholesterol gall stones the present results indicate that Rowachol alone has only weak litholytic properties, at least in normal volunteers, but might have several advantages when combined with chenodeoxycholic or ursodeoxycholic acid.

Adult↗