Hepatitis B virus infection in hospital staff: epidemiology and persistence of vaccine-induced antibodies

To establish the epidemiology of viral hepatitis B (HBV) infection in hospital staff the sera of 2462 workers and 176 professional nursing students were examined. The prevalences of HBsAg and anti-HBs among the workers were 4.5 and 42.2% and among the students were 2.3 and 15.3%, respectively. The risk of infection showed a correlation with the profession of the hospital workers, the various jobs carried out in different departments, age, and the number of working years. The anti-hepatitis vaccination with HBVax and HEVAC-B vaccines was used on 142 professional students and 996 hospital workers. Five years after the beginning of the vaccine cycle the percentage of responders observed among the students was 75 (HBVax) and 79% (HEVAC-B). Among the hospital staff the response registered was 66 and 71%, respectively. The best recorded response among the youngest subjects suggests that the anti-hepatitis vaccination should be obligatory for hospital workers at the beginning of their working period or professional training.

Jejunal and ileal absorption of oxprenolol in man: influence of nutrients and digestive secretions on jejunal absorption and systemic availability

1 Study I evaluated the absorption of oxprenolol in the ileum, compared to jejunum, in healthy volunteers by an intestinal perfusion technique. Around 80 mg of drug were delivered as a saline solution directly in the small bowel. 2 Samples taken 30 cm distally to the site of perfusion showed that 63% of perfused oxprenolol was absorbed in the jejunum and 48% in the ileum; the differences were significant. 3 The plasma concentration-time profiles were similar for the two perfusions. The AUC and Cmax values of free and conjugated oxprenolol for the jejunal perfusion were significantly lower than those of ileum. They showed large but consistent intersubject variations in the two treatments. 4 Study II investigated, using the same technique, the influence of nutrients and digestive secretions on jejunal absorption and systemic availability of this drug. A saline (in treatments A and B) or a nutrient (in treatment C) solution containing oxprenolol was perfused into the jejunum below a balloon either inflated (A) or deflated (B and C). 5 The disappearance rate of oxprenolol from the jejunum was unaffected by endogenous secretions. The mean amount of drug absorbed along a 30-cm jejunal segment accounted for 52 (A) and 57% (B) of the total amount perfused. The intestinal absorption rate was markedly increased in the presence of nutrients (mean amount absorbed 96% for C). 6 The change in the rate of disappearance from the intestine had no effect on the systemic availability of oxprenolol (mean AUC values 8740, 8250 and 8020 nmol l-1 h for A, B and C, respectively) or its elimination from plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric and intestinal absorption of oxprenolol in humans

The gastrointestinal absorption of the beta blocker oxprenolol was investigated in four healthy subjects by an intubation technique. Oxprenolol was introduced into the stomach, dissolved in a homogenized meal containing the marker 14C-polyethylene glycol (PEG) 4000. Unlabeled PEG 4000 was perfused during the whole experiment into the duodenum at the ampulla of Vater. Samples of luminal contents were collected at regular intervals over four hours in the stomach, at the angle of Treitz, and 30 cm below this point. Blood was also collected. Oxprenolol was not absorbed in the stomach. About 80% of the drug emptied from the stomach was absorbed in the duodenum, and 80% of that released from the duodenum was absorbed in a 30-cm segment of the jejunum. The amounts absorbed in these two intestinal segments were directly proportional to the amounts delivered. The areas under the plasma concentration-time curves were not related to the amounts absorbed. A single dose of oxprenolol taken with an homogenized meal did not modify the gastric emptying and secretory response.

Influence of bile salts and lipids on intestinal absorption of griseofulvin in man

The influence of bile salts and lipids on the intestinal absorption of griseofulvin has been studied in 11 healthy male volunteers by the intestinal perfusion technique. The drug in a nutrient solution (Realmentyl) was perfused into the second part of duodenum at 5 ml/min. Intestinal samples were taken continuously at 1 ml/min, 20 cm (at the angle of Treitz) and 45 cm distal to the perfusion point. To study the effect of lipids on griseofulvin absorption, the drug was perfused with solutions A and B, of which B contained a total lipid and caloric load three times that of A. The influence of bile salts on griseofulvin absorption was examined by perfusing the drug on Day 1 with bile salts and again on the following day after bile salt depletion. Bile salts and a varying quantity of lipid perfusate had no significant influence on the duodeno-jejunal griseofulvin absorption rate per cm of intestine. Lipids, however, may still play a role in griseofulvin absorption along the entire intestine.

Effect of increased amounts of pectin on a solid-liquid meal digestion in healthy man

The effect of three concentrations of high-methoxy apple pectin (5, 10, and 15 g), on solid-liquid meal digestion was studied in 12 healthy men by the gastrointestinal intubation technique. The gastric emptying of water and carbohydrates is significantly reduced only after 10 and 15 g pectin. The changes in gastric pH are similar for pectin-free and pectin-containing meals. Cumulative lipase and trypsin outputs are not significantly different with and without pectin. When gastric uronic acid concentration is above 6 g/l, the duodenal absorption of carbohydrates is significantly reduced (p less than 0.001). The mean blood glucose levels with 10 and 15 g pectin are significantly higher than the control values at 180 min (p less than 0.05). Pectin does not modify serum concentrations of secretin, cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP), gastric inhibitory polypeptide (GIP), and somatostatin but serum motilin and gastrin levels are below the control values after high fiber meal.

Jejunal secretory effect of intraduodenal food in humans. A comparison of mixed nutrients, proteins, lipids, and carbohydrates

The effect of the presence of food in the intestinal lumen on fluid transport by an intestinal loop isolated from nutrients is debatable and seems to be species dependent. The aim of the present study was to investigate this effect in humans. Fluid and ion transport by a 30-cm-long jejunal loop was measured by the perfusion of a plasmalike electrolyte solution below an occlusive balloon inflated at the angle of Treitz. At the same time, the duodenum was infused at the papilla by saline (control period) or one of the following solutions (test period): protein hydrolysate, starch hydrolysate, lipids, or mixed nutrients. The four solutions (pH 7; 300 mosmol/L; 540 kcal/L) were infused in 6 normal subjects in a randomized order. In 6 further subjects, two other loads of intraduodenal lipids (120 and 1080 kcal/L) were tested according to a similar protocol. Blood samples were taken serially for radioimmunoassays of gastrin, secretin, cholecystokinin, pancreatic polypeptide, gastric inhibitory polypeptide, vasoactive intestinal polypeptide, motilin, and somatostatin. Intraduodenal mixed nutrients, proteins, and lipids significantly reduced water and ion jejunal net absorption or induced a net secretion (without dose-effect relationship for lipids) and stimulated plasma cholecystokinin, pancreatic polypeptide, and gastric inhibitory polypeptide. Intraduodenal lipids also stimulated circulating levels of gastrin and vasoactive intestinal polypeptide. Intraduodenal sugars did not change jejunal fluid and ion transport and significantly increased plasma gastric inhibitory polypeptide. Covariance analysis showed transjejunal fluid movements to be linked with plasma levels of cholecystokinin. We conclude that an intraduodenal mixed meal exerts a secretory effect on a jejunal loop isolated from the nutrients and that this effect is due to the lipid and protein content of the meal; our data are compatible with a mediation of this phenomenon by cholecystokinin.

Maximal capacity for fluid absorption in human bowel

The intestinal handling of fluid has been studied in ten healthy volunteers while an isotonic saline solution (NaCl 140 mM, KC1 5 mM) was perfused into the stomach at rates of 5, 10, 15, and 20 ml/min. Polyethylene glycol 4000 (PEG-4000), as a nonabsorbable marker, was infused into the second portion of duodenum, and the intestinal contents were sampled continuously at a steady rate at 25, 50, 155, and 180 cm distally. Radiological assessment showed that the proximal sampling point was located at the angle of Treitz when the distal site was usually in the terminal ileum. Stools were collected for the following 12 hr. Volumes sampled from each site were used as a correction for volumes calculated at each distal site. The absorption rates of water (0.035 ml), sodium (4.72 muEq), and potassium ((0.18 183 muEq) per minute and per centimeter of bowel were constant along the small intestine and were independent of the perfusion rate. Stools only appeared when terminal ileal input to the colon was above 6 ml/min. When this occurred, the net absorption of water by the colon was 2.7 +/- 0.3 ml/min whatever the rate fluid entered the colon. A significant positive correlation was observed between ileal outputs and volume of stools.

[Effect of colonic distension on exocrine pancreatic secretion of the conscious rat]

In the conscious rat the increasing distension of the colon (from 2 to 6 ml) induced a slight decrease of exocrine pancreatic secretion which was more important for protein output than for volume. Nevertheless this inhibitory effect was never significant even with the important distension of 6 ml which induced a visible uneasiness in the animal.

[Endotoxin content of samples of pasteurized milk: preliminary findings]

By Limulus lysate assay, endotoxin was found in pasteurized milk samples from commercial source. The range was 32 to 128 microgram per ml, without any change when the samples were refrigerated. By contrast, the endotoxin content rose 512 to 2048 microgram per ml when milk was maintained at room temperature for 24 hours and 1024 to 6400 microgram per ml when samples were examined after 72 hours. These findings suggest a possible clinical implication, and support the concept that Limulus assay appears to be a rapid, reliable, and sensitive test for a quality control in commercial milk samples.

Secretion of biliary lipids in young Chilean women with cholesterol gallstones

The early appearance of cholesterol gallstones is very common in Chile. To elucidate the mechanisms involved in this phenomenon, the size of the bile acid pool and the secretion of biliary lipids were studied in two groups of young women with normal weights and radiologically functioning gallbladders: nine with cholesterol gallstones and 14 healthy volunteers. The bile acid pool was similar in control and gallstone patients. The secretory rates of bile acids and phospholipids were comparable and significantly correlated in both groups. On the other hand, cholesterol output was higher in gallstone patients. In controls there was a significant correlation between the output of bile acids and cholesterol, but no correlation was found in the gallstone group. This study suggests that cholesterol hypersecretion into the bile is a major factor in the pathogenesis of cholesterol gallstone disease in young Chilean women with normal weights.

[Endotoxic contamination of biological products (ribosomal vaccines, viral vaccines and interferon)]

The A.A. have examined by the Limulus assay the possible endotoxin contamination in some biological products (ribosomal vaccines, viral vaccines, interferon). While the preparations of influenza vaccines and a partially purified fraction of ribosomal vaccine from Pseudomonas aeruginosa exhibit a gelation of lysate with high levels of endotoxin, rubeola vaccines, interferon and a purified fraction of ribosomal vaccine, presented a negligible amount of endotoxin. The results are discussed with the aim to examine the possible role of contaminating endotoxin in the mediation of some adverse effects and of the unsuspected extrinsic adjuvant activities developed in clinical and experimental use of these preparations.

Planning a food and nutrition surveillance system: the example of Honduras

A description of the preliminary steps in establishing a food and nutrition surveillance system in a country of Central America is presented in outline. The system will provide the basis for policy formulation, program planning, and evaluation. It is organized on the basis of the participation and resources of seven national agencies and will operate at the local, regional, and central level.

Effect of aging on biliary lipid composition and bile acid metabolism in normal Chilean women

Biliary lipid composition was determined in fasting gallbladder bile of 12 young and 12 elderly asymptomatic Chilean women with normal weights and recent, normal cholecystograms. The proportion of biliary cholesterol and the lithogenic index were significantly higher in elderly females. Moreover, supersaturated bile was present in 8.3% of the young and in 41.7% of the older women studied. Obesity enhances the saturation of bile in older females: lithogenic bile was found in 100% of 4 elderly, obese women with radiologically normal gallbladders. The bile acid pool and cholic acid metabolism were studied in 5 young and 4 older normal females. Both groups showed similar values of bile acid pool, cholic acid synthesis, and turnover. These results indicate that aging per se modifies the proportions of biliary lipids in Chilean women, and provide a partial explanation for the frequency of gallstones observed among them. The increment in the lithogenic index of gallbladder bile with age takes place without significant changes in bile acid metabolism, suggesting that the canalicular secretion of cholesterol increases with aging.