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Heat-shock protein 70 (HSP70) plays a crucial role as intracellular cytoprotectant and molecular chaperone. A phenomenon of heat stress (HS) leads to production of these proteins that could be beneficial to cells during cryopreservation, which is also a stressful process for the cell. This study aimed to evaluate the protective effect of exposure of bovine oocytes to moderate HS during in vitro maturation (IVM) prior vitrification. First, oocytes were subjected to HS (41.5°C for 1 hr) at 0, 4, 8, 12 or 16 of IVM. Oocytes in vitro matured for 20 hr served as control group. Presence of HSP70 was detected at 20 hr by immunofluorescence. HSP70 expression was significantly higher when oocytes were subjected to HS at 8 hr of IVM. Next, oocytes were distributed into four groups: Control: IVM oocytes; VIT: oocytes vitrified/warmed at 20 hr of IVM; HS: oocytes subjected to HS at 8 hr of IVM; HS-VIT: oocytes subjected to HS at 8 hr of IVM and vitrified/warmed at 20 hr of IVM. Oocytes were fertilized at 24 hr of IVM, and cleavage and blastocyst yield were assessed. No significant differences were observed among treatments when cleavage rate was evaluated. However, fresh control and HS oocytes resulted in a significantly higher (p < .05) blastocyst rate when compared to VIT and HS-VIT groups, although no significant differences within fresh or vitrified groups were observed. In conclusion, HS did not have a negative impact on the oocyte competence but HS applied before vitrification, offered no benefits for embryo development.

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An intestinal permeability test analyzing the differential urinary elimination of lactulose and mannitol orally ingested at the same dosage allowed us to establish a significant correlation between alterations of intestinal permeability and ingestion of reputedly hypoallergenic foods, breast milk, and hydrolyzed protein formulas in some infants with cow's milk allergy. In all, clinical disappearance of symptoms was observed after removal of milk from the mother's diet and/or elimination from the child's diet of any cow's-milk-based hypoallergenic formula.

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The effect of diosmectite on intestinal permeability changes in acute diarrhea was measured during a double-blind placebo-controlled trial carried out in 59 Gabonese children aged 5-35 months. Intestinal permeability tests (IPTs), measuring the urinary elimination of orally administered lactulose and mannitol at a dosage of 1 g/10 kg each, were performed during the morning following admission and repeated 2 days later after treatment by diosmectite or placebo. During the first IPT, urine volume and lactulose and mannitol urinary recoveries were comparable in the diosmectite and in the placebo groups: 50 vs. 35.5 ml (median; p = 0.21), 1.01 vs. 1.27% (p = 0.35), and 2.20 vs. 2.87% (p = 0.12). As a result, the lactulose/mannitol (L/M) ratio was similar in the two groups: 44.44 vs. 35.33% (p = 0.98). During the second IPT, the urinary lactulose recovery decreased similarly in both groups (-0.18 vs. -0.29%; p = 0.76), whereas the urinary mannitol recovery exhibited opposite variations, the increase in the diosmectite group (+ 1.43%) contrasting significantly with the decrease in the placebo group (-0.47%; p = 0.01). When comparing the first and the second IPT, the decrease of the L/M ratio was significant in the diosmectite group (44.44 vs. 28.32%; p = 0.02) and not in the placebo group (35.33 vs. 48.23%; p = 0.91). During gastroenteritis, diosmectite appears to enhance absorption of mannitol, a marker of intestinal absorptive area.

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In infants, food allergies are usually manifested by digestive symptoms and the most commonly involved antigens are cow's milk proteins. Although the full range of clinical manifestations of cow's milk protein sensitivity may occur as soon as birth, enteropathy is the most common pattern. As the infant grows, cow's milk antigens lose their predominance as the causative agents of adverse reactions to foods. All foods may be involved, and consequently diagnostic evaluation is more difficult. The gastrointestinal tract is no longer the preferred target organ and symptoms of food allergy may be systemic, cutaneous or, in a smaller number of cases, respiratory. History taking is the first step of the diagnostic process and provides very valuable data. Skin tests and in vitro detection of specific IgE antibodies are then performed. Results of the skin tests may help select the most appropriate in vitro tests. Diagnosis is always established by diet modifications using diets free of the suspected offending food, followed by challenge tests. Intestinal permeability tests provide a noninvasive means for demonstrating intestinal reactivity.

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An intestinal permeability test (IPT) analysing the mannitol (M) and lactulose (L) clearances and the L/M ratios was performed in 15 children followed for celiac disease, before the onset of exclusion diet, during the gluten-free diet and after the reintroduction of gluten. The results showed a significant increase of the L/M ratios under normal diet, with respect to a control population. This increase was related to an increased L urinary excretion and to a decrease in M excretion. During gluten-free diet a normalization of the L/M ratios was observed. Reintroducing gluten altered the L/M ratios by increasing the L intestinal permeability and decreasing the M intestinal permeability. This study shows the value of the non invasive L/M IPT for the screening and monitoring of celiac disease in children.

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The intestinal mucosa has a certain degree of "porosity", which allows some molecules and macromolecules that are not subject to active transport, to cross the intestinal wall and enter the blood circulation. This permeability of the intestinal mucosa, which depends mostly on the size of the molecule and the state of the mucosa, can be studied with the assistance of protein macromolecules in an allergy-immunological investigation, or with inert markers, so permitting evaluation of the state of integrity of the small intestine. The markers used are polyethylene glycols (PEG) of various molecular weights, Cr EDTA, the monosaccharide sugars mannitol or rhamnose and the disaccharide sugars lactulose or cellobiose. Study of the intestinal permeability to inert markers allows detection of coeliac or Crohn's disease. It can be repeated, especially at the time of food provocation tests needed in the diagnosis of food intolerances in pediatrics in the enteropathology to cows milk proteins, atopic dermatitis and irritable colon in children.

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An intestinal permeability test analyzing the differential urinary elimination of lactulose and mannitol orally ingested at the same dosage was carried out first in fasting condition, then combined with specific food ingestion, in 17 children with clinical symptoms of irritable bowel syndrome (IBS). Foods were selected based on a suggestive clinical history or on a positive radioallergosorbent or prick test. Comparison of the results with those of a control population reported in a previous study showed that in nine IBS patients, specific food ingestion was associated with a modification of intestinal permeability. The nine children all had a personal and/or familial history of allergy and/or raised total IgE. The symptoms disappeared in the nine patients after food exclusion either alone (seven patients) or together with further treatment by cromolyn (two patients). We conclude that, at least in some children, symptoms of IBS may be related to food hypersensitivity.

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Intestinal permeability was evaluated by measuring the excretion of two orally absorbed (0.1 g/kg of weight) nonmetabolizable markers, mannitol and lactulose. In 39 controls, the lactulose/mannitol urinary ratio (L/M ratio) was 2.45 +/- 1.01% during fasting and remained stable after food ingestion. In 12 children with cow's milk-sensitive enteropathy under an exclusion diet, the L/M ratio was comparable with that of controls during fasting and exhibited a threefold rise during a provocation intestinal permeability test (IPT) with milk. In 28 children with atopic dermatitis (AD), the fasting IPT L/M ratio was significantly higher than in controls (3.60 +/- 3.31%). This rise was related to an increase of lactulose urinary clearance. A provocation IPT with food induced significant L/M ratio changes only in the group in which the food was proved to be responsible for the exacerbation of skin lesions. We concluded that in cow's milk-sensitive enteropathy, an IPT allows a good evaluation of mucosal reactivity to milk, and in AD, permeability changes are present in at least some cases with cutaneous lesions clearly related to food ingestion.

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Intestinal permeability to macromolecules was studied by measuring differential urinary elimination of two orally ingested non-metabolizable sugars of different molecular size, mannitol and lactulose. In 25 control children, mannitol and lactulose urinary elimination were 16.30 +/- 5.77% and 0.33 +/- 0.10% of ingested dose, respectively, with a mean lactulose/mannitol (M/M) urinary ratio of 2.73 +/- 0.70%. In 7 celiac children, L/M ratio exhibited a significant rise: 8.53 +/- 2.54% (p less than 0.001). In 7 children with cow's milk sensitive enteropathy under exclusion diet, L/M ratio was normal in fasting condition: 2.63 +/- 1.28% and raised significantly during provocation test with milk: 7.22 +/- 3.88% (p less than 0.01). Intestinal permeability test is a reliable index of villous atrophy and cow's milk sensitive enteropathy.

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