Effect of breast feeding time on physiological, immunological and microbial parameters of weaned piglets in an intensive breeding farm.

The aim of this work was to study the long-lasting consequences of different weaning age on physiological, immunological and microbiological parameters of weaned piglets. Piglets were weaned at 14 days (14W) or 21 days (21W). Blood samples were taken for IgG and cortisol determination on preweaning day and at 4; 20 and 40 post-weaning days. Three animals of each group were sacrificed. Small intestines for morphometric studies and secretory-IgA determination in fluid were taken. The cecum was obtained for enterobacteria, lactobacilli and total anaerobes enumeration. A significant decrease in piglet's plasma IgG concentrations was observed immediately after weaning and no differences were found between 14W and 21W. An increase in intestinal S-IgA was observed according to piglet's age. This increase was significantly higher in piglets 14W compared to piglets 21W. Animals from 14W group showed a decrease in villus length and in the number of goblet cells and intraepithelial lymphocytes. Other parameters were not affected by the weaning age. A short-term increase in cortisol was observed after weaning in both experimental groups. Enterobacteria decreased significantly after weaning in both groups, reaching values of weaning after 40 days. Lactobacilli counts decreased in both groups after weaning; however their counts were always higher than those obtained for enterobacteria. No differences were observed between 14W and 21W with regards to counts of anaerobes. The shortening of breast feeding time would favor an early synthesis of intestinal S-IgA after weaning. The changes observed in the microbiota could decrease postweaning enteric infections. However, early weaning induced negative effects on the cells of gut innate immunity and villi atrophy. This work provides knowledge about advantages and disadvantages at different weaning and long-lasting consequences on pig health. It is critical that swine producers become aware of the biological impacts of weaning age, so as to be able to decide the appropriate management strategies according to their facilities and rearing environment.

Different responses of lymphocyte to human placenta conditioned medium in vitro.

Several cytokines appear to be implicated in peri-implantation events and in maternal-fetal interaction. The majority of these molecules appear in supernatants or in extracts of placental origin. The purpose of this study was to investigate the action of human placenta conditioned medium (HPCM) on peripheral lymphocytes in vitro. Peripheral lymphocytes of women with different numbers of deliveries, of nulliparous and pregnant women, as well as of men, were cultivated in their own plasma with and without HPCM at 5%, 10% and 20%. The index of lymphocyte blast transformation (ILBT) was determined (values of > or = 0.5 indicated stimulation). In women who had had children, the highest lymphocyte blastogenesis was observed with HPCM at 10%, this finding being correlated to the numbers of deliveries (r = 0.828). In pregnant women, even though the highest answer was also obtained with HPCM at 10%, the addition of suboptimal concentration of HPCM (5%) produced blastic transformation (IBLT: x = 0.54 +/- 0.05), which was not observed in women who had had children. Lymphocytes of men and nulliparous women did not respond to any of the HPCM concentrations tested. In conclusion, HPCM at 10% was still the best concentration to produce lymphocyte blastogenesis. In addition, in the plasma of pregnant women, there may be some substance that enhanced the action in vitro of the extract, thus permitting threshold reduction necessary for lymphocyte stimulation.

Human placenta conditioned medium as a source of lymphocyte blastogenesis in vitro.

The purpose of this work was to obtain placental extracts with the capacity of producing lymphocyte blastogenesis. Placental homogenates were incubated at 37 degrees C in McCoy's 5A supplemented with 5% fetal bovine serum and 25 mM Hepes. After a 6-day incubation period, the cultures were harvested and the sterility and cellular viability were controlled. The supernatant was centrifuged at 22,000g at 4 degrees C for 30 minutes. Sterilization was achieved by filtration (0.22 microns). This medium was denominated human placenta conditioned medium (HPCM-1). The other half of the original placenta was processed by the Burgess method and the extracts thus obtained were denominated HPCM-2. The activity of the extracts thus obtained was tested in peripheral lymphocyte cultures from women after the third pregnancy; 5, 10 and 20% HPCM-1 or HPCM-2 was added to these cultures and the index of lymphocyte blast transformation (ILBT) was determined. The highest stimulation occurred at 10% HPCM. The ILBT obtained with HPCM-1 at 10% was more constant than that obtained with HPCM-2 at the same concentration. In conclusion, it can be assumed that this methodology is appropriate to obtain conditioned media from human placenta with good blastogenic activity on peripheral lymphocytes in vitro.

[Evaluation of the method for early pregnancy factor detection (EPF) in swine. Significance in early pregnancy diagnosis]. / Evaluación del método de detección del factor precoz de preñez (EPF) en cerdos. Importancia en el diagnóstico temprano de gestación.

Early pregnancy factor (EPF) is a protein detected in the serum of pregnant females in most mammals, before implantation of the embryo; its activity is detected by the rosette inhibition test (RIT). After preincubation of lymphocytes in serum of non-pregnant pigs, the mean titre of RIT was 10.80 +/- 0.32. The upper limit of the 95% confidence interval was calculated to be 11.44. Therefore, all titres 12 were defined indicating the presence of EPF activity. The incubation of lymphocytes in serum of pregnancy caused a significant increase in the mean rosette inhibition titre, raising it to 19.88 +/- 1.13 (p < 0.001). False negative results were obtained for 10% of pregnant pigs. EPF positive activity was detected in only one non-pregnant pig (RIT = 20). This assay is not quantitative nor suitable for pregnancy diagnosis taking into account RIT values dispersion.

Evaluación del método de detección del factor precoz de preñez (EPF) en cerdos. Importancia en el diagnóstico temprano de gestación. / [Evaluation of the method for early pregnancy factor detection (EPF) in swine. Significance in early pregnancy diagnosis]

Early pregnancy factor (EPF) is a protein detected in the serum of pregnant females in most mammals, before implantation of the embryo; its activity is detected by the rosette inhibition test (RIT). After preincubation of lymphocytes in serum of non-pregnant pigs, the mean titre of RIT was 10.80 +/- 0.32. The upper limit of the 95

confidence interval was calculated to be 11.44. Therefore, all titres 12 were defined indicating the presence of EPF activity. The incubation of lymphocytes in serum of pregnancy caused a significant increase in the mean rosette inhibition titre, raising it to 19.88 +/- 1.13 (p < 0.001). False negative results were obtained for 10

of pregnant pigs. EPF positive activity was detected in only one non-pregnant pig (RIT = 20). This assay is not quantitative nor suitable for pregnancy diagnosis taking into account RIT values dispersion.

Evaluación del método de detección del factor precoz de preñez (EPF) en cerdos. Importancia en el diagnóstico temprano de gestación. / [Evaluation of the method for early pregnancy factor detection (EPF) in swine. Significance in early pregnancy diagnosis]

Early pregnancy factor (EPF) is a protein detected in the serum of pregnant females in most mammals, before implantation of the embryo; its activity is detected by the rosette inhibition test (RIT). After preincubation of lymphocytes in serum of non-pregnant pigs, the mean titre of RIT was 10.80 +/- 0.32. The upper limit of the 95

confidence interval was calculated to be 11.44. Therefore, all titres 12 were defined indicating the presence of EPF activity. The incubation of lymphocytes in serum of pregnancy caused a significant increase in the mean rosette inhibition titre, raising it to 19.88 +/- 1.13 (p < 0.001). False negative results were obtained for 10

of pregnant pigs. EPF positive activity was detected in only one non-pregnant pig (RIT = 20). This assay is not quantitative nor suitable for pregnancy diagnosis taking into account RIT values dispersion.

Lymphocyte blastogenesis in children with cow's milk hypersensitivity after its elimination from the diet.

The relationship between ingestion of cow's milk and lymphocyte transformation in cow's milk allergic children was studied. Fifty-six children were selected. Nineteen of them suffered from cow's milk hypersensitivity (HCM); 22 were allergic to several agents except to cow's milk (HOE) and 15 normal and healthy children composed the control group (NH). Lymphoblastogenesis was measured by tritiaded thymidine uptake and the cells were cultured with plasma from the same individual. The lymphoblastogenesis was indirectly estimated by the following equation: (formula; see text) where cpm I represents lymphoblastogenesis estimulated by PHA-M and cpm E represents lymphoblastic transformation with no antigen added to the culture medium. BTI was determined before and 30 days after the elimination of cow's milk from the diet. Lymphoblastogenesis, in the samples obtained before the elimination diet, was significantly increased (BTI decreased) in HCM group but not in the others (p less than 0.01). There was no difference in the lymphoblastogenesis behaviour of the three groups after 30 days of exclusion diet. The difference between the BTI values obtained before and after the elimination cow's milk from the diet would be helpful in the early diagnosis of cow's milk allergy.