EFFECTS OF PROTEIN-DEFICIENCY AND NATURAL INTESTINAL INFECTION WITH GIARDIA-LAMBLIA ON JEJUNAL INTRAEPITHELIAL LYMPHOCYTES IN RATS OF DIFFERENT AGES

1. The interaction between experimental protein deprivation and natural intestinal infection by Giardia lamblia was studied in terms of its effects on the intraepithelial lymphocyte (IEL) population and morphology of the jejunal mucosa of rats of different ages.2. Young, adult and old male Wistar rats received a protein-deficient diet (2% casein) or a control diet (20% casein) for 42 days. Mucosal height and the number of lymphocytes located among 500 consecutive epithelial cells (EC) along the villi or crossing the basement membrane were determined in PAS-stained jejunal fragments.3. The number of IEL increased progressively with animal age, from 14 to 25 per 100 epithelial cells, with significant differences between age ranges. However, the number of IEL did not differ between control and protein-deficient rats in any of the age groups. The proportion of lymphocytes crossing the basement membrane was approximately two-fold greater in young (2.8/100 EC) and adult (5.8/100 EC) protein-deficient animals than in their respective controls (1.6 and 2.8/100 EC). The intensity of parasite colonization was moderate, from 3 to 5/100 EC and did not differ between groups. The pattern of morphologic changes of jejunal mucosa in protozoal infection did not differ between control and protein-deficient animals in any of the three age groups.4. We conclude that intestinal infection with Giardia lamblia probably stimulated the local immune response, masking the reduction of the IEL population induced by protein deficiency. The increase in lymphocyte numbers with age may be related to prolonged antigenic stimulation promoted by infection.

INTERFERENCE BETWEEN SALMONELLA SEROTYPES IN INTESTINAL COLONIZATION OF CHICKENS - CORRELATION WITH IN-VITRO BEHAVIOR

The effect of colonisation of the alimentary tract of newly hatched chicks by different Salmonella serotypes on the establishment in the gut by other Salmonella strains inoculated afterwards was assessed. Although profound inhibition of colonisation had been found previously to be genus-specific, considerable variation was found within the Salmonella genus. Some strains were found to be much more inhibitory than others and some were more easily inhibited than were others. There was not an absolute relationship between inhibitory activity and colonisation ability. No relationship was seen between inhibition and serotype or phage types within serotypes. There was no correlation between in vivo inhibition and the extent of inhibition that occurred in early stationary phase cultures in rich, undefined broth cultures.

Intestinal antiinflammatory activity of a lyophilized infusion of Turnera ulmifolia in TNBS rat colitis

Turnera ulmifolia is a plant popularly known in Brazil and South America as chanana. Some species of Turnera are widely used in folk medicine for different types of inflammatory diseases. In this study, the preventive intestinal antiinflammatory activity of a lyophilized infusion obtained from the aerial parts of T. ulmifolia was tested in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. The results obtained revealed that pretreatment to colitic rats with the extract, at 250 and 500 mg/kg, significantly attenuated the colonic damage induced by TNBS. This beneficial effect was associated with an improvement in the colonic oxidative status, since the infusion prevented the glutathione depletion that occurred as a consequence of the colonic inflammation. on the other hand, this antioxidant activity was confirmed in in vitro studies. In conclusion, the preventive effect exerted by the lyophilized infusion of T. ulmifolia in the TNBS model of rat colitis is probably related to its antioxidant properties, due to its flavonoids content. (c) 2006 Elsevier B.V. All rights reserved.

Posthatching water and feed deprivation affect the gastrointestinal tract and intestinal mucosa development of broiler chicks

We studied the effect of feed and water deprivation on gastrointestinal tract and intestinal mucosa development of chicks at 24, 48, and 72 h posthatching. The treatments were water and feed ad libitum, water ad libitum and no feed, no water but feed ad libitum, and no water and no feed. The relative weight of the yolk sac was not influenced by the treatments. However, at 48 and 72 h posthatching, the relative weight of the liver increased, and the gizzard + proventriculus weight decreased in birds receiving feed ad libitum. An increase in jejunum and ileum relative weights and lengths was observed when the birds were supplied with feed and water. The lack of water produced the same effect as the lack of feed, both causing a higher number of villi per area with reduction in villus size, when compared with feed and water ad libitum treatments. The results of this study revealed that feed and water are able to affect intestinal villus development after hatching, indicating that both feed and water must be supplied to the chicks immediately after hatching.

A phase III randomized double-blind placebo-controlled clinical trial to determine the efficacy of low level laser therapy for the prevention of oral mucositis in patients undergoing hematopoietic cell transplantation

Introduction Oral mucositis (OM) is a significant early complication of hematopoietic cell transplantation (HCT). This phase III randomized double-blind placebo-controlled study was designed to compare the ability of 2 different low level GaAlAs diode lasers (650 nm and 780 nm) to prevent oral mucositis in HCT patients conditioned with chemotherapy or chemoradiotherapy.Materials and methods Seventy patients were enrolled and randomized into 1 of 3 treatment groups: 650 nm laser, 780 nm laser or placebo. All active laser treatment patients received daily direct laser treatment to the lower labial mucosa, right and left buccal mucosa, lateral and ventral surfaces of the tongue, and floor of mouth with energy densities of 2 J/cm(2). Study treatment began on the first day of conditioning and continued through day +2 post HCT. Mucositis and oral pain was measured on days 0, 4, 7, 11, 14, 18, and 21 post HCT.Results the 650 nm wavelength reduced the severity of oral mucositis and pain scores. Low level laser therapy was well-tolerated and no adverse events were noted.Discussion While these results are encouraging, further study is needed to truly establish the efficacy of this mucositis prevention strategy. Future research needs to determine the effects of modification of laser parameters (e.g., wavelength, fluence, repetition rate of energy delivery, etc.) on the effectiveness of LLE laser to prevent OM.

Anti-inflammatory intestinal activity of Abarema cochliacarpos (Gomes) Barneby & Grimes in TNBS colitis model

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphometric study of the small intestinal mucosa in young, adult, and old rats submitted to protein deficiency and rehabilitation

Linear and stereological morphometric methods were applied to the jejunal and ileal mucosa of young, adult, and old male Wistar rats submitted to protein deficiency and rehabilitation. The animals were fed ad libitum a 2% casein diet during 42 days and then received a 20% casein diet for 30 days. Food intake, body weights, and plasma protein concentrations were recorded. In the young protein deficient rats values of mucosal height, surface area, and volume of the lamina propria were significantly lower than those of their age controls in both jejunum and ileum. In adults the differences were less marked and in the old rats all parameters were found to be unaltered by the protein deficient diet. The surface-to-volume ratio showed no significant differences between control and protein deficient in all three age groups, meaning that villus pattern did not change with protein deficiency. On rehabilitation, a striking difference between jejunum and ileum was observed in the young rats; all parameters returned to control levels in the jejunum, while they remained lower than those of their controls in the ileum.

Efeitos do tipo de ração inicial sobre a morfologia intestinal e digestibiliade dos nutrientes em leitões

Thirty piglets, weaned at an average age of 28 days, were used in experiment one. After weaning, 24 animals were transferred to the nursery in groups of two to each pen and fed simple or semi-complex diets ad libitum. On weaning day (day 0), six pigs were slaughtered. On days 7 and 21 post-weaning, one animal from each nursery pen was slaughtered to study mucosal thickness (MTD and MTJ) and villi heights (VHD and VHJ) in the duodenum and jejunum. The average values observed for MTD, VHD, MTJ, and VHJ were not influenced by type of diet. MTD, MTJ, and VHJ increased from days 7 to 21 post-weaning. Polynomial regression spanning days 0, 7, and 21 showed a linear effect for MTJ and a quadratic effect for VHD and VHJ. In experiment two, 16 piglets weaned at an average age of 28 days were used in two metabolic trials carried out during two periods of the initial phase (days 5 to 14 and days 19 to 28 postweaning), to determine the nutritional value of simple and semi-complex diets. There were no differences among treatments in apparent digestibility of crude protein and dry matter and the values for digestible or metabolizable energy of the diets. It was concluded that composition of the starter diet did not influence the intestinal morphology of piglets, the digestibilities of dry matter and crude protein, or the digestible and metabolizable energy contents of the diets.

Intestinal colonization of a human subject by vancomycin-resistant Enterococcus faecium

Objective: To study the ability of two strains of vancomycin-resistant Enterococcus faecium to colonize the human intestine. Methods: A single human subject ingested separately two strains of vancomycin-resistant E. faecium isolated from a pig and a chicken. The feces were cultured on selective medium. Prior to ingestion no vancomycin-resistant cocci were present in the feces. Ingestion of 10 4-10 5 CFU resulted in either no colonization or isolation only after enrichment. Ingestion of 10 7 CFU of one strain resulted in colonization for a period of nearly 3 weeks, with fecal counts at times in excess of 10 6 CFU/g. Ingestion of similar numbers of the other strain and reingestion of the first strain resulted in excretion in the feces for much shorter periods. When the fecal count of the ingested strains was greater than 10 4-10 5 CFU/g, the strains were isolated from swabs taken from perianal skin. Conclusions: Vancomycin-resistant E. faecium strains from pigs and poultry a re able to colonize the human gut and the perianal skin.

Refining the intestinal motility test in mice to reduce animal stress

A new protocol using 3-h fast animal for intestinal motility test was developed in our laboratory aiming the 3R's concept to reduce the stress of animals. Our results may aid in formulating recommendations that can be included in revised guidelines with regard to fasting time of mice.

The ultrastructure of the intestinal epithelium in Oreochromis niloticus on a diet with different concentrations of zinc

The effects of diets with variable zinc levels on the midgut epithelial cells were studied in Oreochromis niloticus L. One hundred and twenty fry of tilapia were apportioned into 4 experimental groups (I, II, III and IV groups), with 30 fish in each treatment, 5 replicate aquaria per treatment containing 6 fish each. The animals of the 4 groups were fed with isonitrogenous (30% crude protein) and isoenergetic (3000 Kcal/Kg of digestible energy) diets with increasing quantities of zinc (44.59; 149.17; 309.93; 599.67 mg Zn/kg of diet), twice a day, for 93 days. Three fish from each group were sacrificed at 36, 66 and 93 days and samples of midgut were removed for ultrastructural analysis. After 93 days of treatment, 3 animals of each experimental group were used for the analysis of zinc concentration by atomic absorption spectrophotometry. The comparative relative index (CRI) revealed that the animals in groups II, III and IV contained, respectively, 1.99%, 34.67% and 22.78% more zinc than the mean concentration in animals from group I. The ultrastructural analysis showed enterocytes with swelling of smooth surfaced endoplasmic reticulum and dilated mitochondria with variable matrix rarefaction and cristae number reduction in the fish exposed to 599.67 mg Zn/Kg of diet at 66 and 93 days of treatment.

Protocol to refine intestinal motility test in mice

We propose a new protocol intended to conform to the 3Rs (replacement, reduction, and refinement) principle, using animals fasted for 3 h to control intestinal motility, which reduced stress in the animals. In this new protocol, mice are deprived of food for a short time (3 h) and are not killed. The mice are observed until evacuation containing charcoal is observed, and the experimental results are based on the charcoal evacuation time. The present study may aid the formulation of recommendations that can be included in revised guidelines relating to the fasting time of mice. This new concept of an intestinal motility test conforms with respectful science.