Effect of cyclodextrin-loaded cholesterol conjugates on plasma membrane viability of Piau swine breed frozen/thawed spermatozoa.

The objective of this study was to investigate the effect of cyclodextrin-loaded cholesterol conjugates addition to freezing extenders on plasma membrane viability of frozen-thawed spermatozoa of the Piau swine breed. Twenty semen samples were used from five males. The freezing extender was based on lactose-egg yolk extender, added to 2% glycerol, 3% dimethylacetamide. The addition of cyclodextrin-loaded cholesterol conjugates was performed after centrifugation, when semen was diluted with the cooling extender. Four groups were subjected to the following treatment: without addition (group 1); 1.5 mg of cyclodextrin-loaded cholesterol/120 × 10(6) sperm (group 2); 1.5 mg of cyclodextrin-loaded cholestanol/120 × 10(6) sperm (group 3); 1.5 mg of cyclodextrin-loaded desmosterol/120 × 10(6) sperm (group 4). To check post-thawing sperm quality sperm motility and sperm morphology evaluation were used. Additionally, to check sperm viability the hypoosmotic swelling test, supravital staining, and fluorescent assay were used. The mean values recorded for total sperm motility of semen immediately after thawing were 54.5 ± 5.8, 55.5 ± 5.3, 53.7 ± 6.7, and 52.5 ± 6.6% respectively for groups one to four, without difference between themselves (p > 0.05). Regarding fluorescent assay the results were 28.3 ± 13.2, 26.9 ± 12.2, 22.2 ± 11.4, and 32.0 ± 15.3% respectively for groups one to four, also without difference between groups (p > 0,05). Similarly, complementary tests for evaluating the integrity and functionality of the plasma membrane showed no difference between treatments (p > 0.05). In conclusion, use of cyclodextrin-loaded cholesterol conjugates added to the plasma membrane of sperm did not demonstrate any additive effect on increasing and/or maintaining sperm motility.

Optimization performance of an AnSBBR applied to biohydrogen production treating whey.

The present study investigated the influence of the influent concentration of substrate, feeding time and temperature on the production of biohydrogen from cheese whey in an AnSBBR with liquid phase recirculation. The highest hydrogen yield (0.80 molH2.molLactose(-1)) and productivity (660 mLH2 L(-1) d(-1)) were achieved for influent concentrations of 5400 mgDQO L(-1). No significant difference was noted in the biological hydrogen production for the feeding time conditions analyzed. The lowest temperature tested (15 °C) promoted the highest hydrogen yield and productivity (1.12 molH2 molLactose(-1) and 1080 mLH2 L(-1) d(-1)), and for the highest temperature (45 °C), hydrogen production did not occur. The indicator values for the hydrogen production obtained with this configuration were higher than those obtained in other studies using traditional configurations such as UASBr and CSTR. A phylogenetic analysis showed that the majority of the analyzed clones were similar to Clostridium. In addition, clones phylogenetically similar to the Lactobacilaceae family, notably Lactobacillus rhamnosus, and clones with similar sequences to Acetobacter indonesiensis were observed in small proportion in the reactor.

Evaluation of antimicrobial consumption in the neonatal population undergoing antimicrobial stewardship programmes: a systematic review.

BACKGROUND: Indiscriminate use of antimicrobials in neonatal sepsis treatment contributes to consumption misuse, and the optimization of prescription programmes is encouraged as a way of reducing this inappropriate use. AIM: To evaluate the impact of intervention programmes for adequate antimicrobial use (antimicrobial stewardship programmes) in consumption measurements of such drugs in neonatology. METHODS: The search for articles was performed in electronic databases and by manual search for citations in publications initially identified. Electronic databases searched were BVS (Virtual Health Library), Cochrane Library, Embase, MEDLINE/PubMed, SciELO, Scopus, and Web of Science. There was no date or period limit for inclusion of articles. The PICO question was defined as populations of neonates admitted to neonatal intensive care units undergoing an intervention programme to optimize antimicrobial therapy in relation to neonates not exposed to the programme and the outcome obtained in antimicrobials consumption. FINDINGS: The initial search in databases resulted in 1223 articles. Articles were screened and 16 original studies related to subject were selected, which conducted a quantitative approach to antimicrobials consumption for the population of interest. Most articles used days of therapy (DOT) as the main measure of antimicrobial consumption and have had a high-quality rating by Newcastle-Ottawa Scale. All studies were carried out in local hospitals at a single centre and most were in high-income countries. CONCLUSION: Of all studies identified by the search, few evaluated antimicrobial consumption in neonatology. New studies are needed, and DOT was shown to be the most adequate metric to measure consumption.

Maturation of mononuclear phagocytes in the lungs of young calves--in vitro study.

The influences of age in calves' immune system are described in their first phase of life. We hypothesized that variations that occur in the main mechanisms of lung innate response can help to identify periods of greater susceptibility to the respiratory diseases that affect calves in the first stage of their life. This study aimed to evaluate the innate immune system. Nine healthy calves were monitored for 3 mo and 8 immunologic evaluations were performed. Bronchoalveolar lavage samples were recovered by bronchoscopy. The alveolar macrophages in samples were identified by protein expression of cluster of differentiation 14 (CD14) and underwent functional evaluation of phagocytosis (Staphylococcus aureus stained with propidium iodide and Escherichia coli). Data was assessed by one-way ANOVA (unstacked and parametric) and the Mann-Whitney test (nonparametric). Functional alterations in CD14-positive phagocytes were observed, with punctual higher intensity of phagocytosis in the third week and its decrease starting at 45 d of life. A gradual increase in phagocytosis rate was observed starting at this date. It is concluded that from 45 d of life on, alveolar macrophages have less phagocytic capacity but more cells perform this function. We suggest that this occurs because lung macrophages of calves start to maintain their immune response without passive immunity influence. Until 90 d of life, calves did not achieve the stability to conclude the maturation of local innate immune response.

Richness of endophytic fungi isolated from Opuntia ficus-indica Mill. (Cactaceae) and preliminary screening for enzyme production.

Opuntia ficus-indica Mill. (forage cactus) is farmed with relative success in the semi-arid region of the Brazilian northeast for commercial purposes, particularly as forage and food. Endophytic microorganisms are those that can be isolated inside plant tissues and can be a new source to production of enzymes with different potentialities. The objective of this study was to describe the richness of endophytic fungi from O. ficus-indica and to detect the capacity of these species to produce extracellular hydrolytic enzymes. Forty-four endophytic fungi species were isolated. Among them, the most commonly found were Cladosporium cladosporioides (20.43%) and C. sphaerospermum (15.99%). Acremonium terricola, Monodictys castaneae, Penicillium glandicola, Phoma tropica and Tetraploa aristata are being reported for the first time as endophytic fungi for Brazil. The majority of isolated fungi exhibited enzymatic potential. Aspergillus japonicus and P. glandicola presented pectinolytic activity. Xylaria sp. was the most important among the other 14 species with positive cellulase activity. All 24 isolates analysed were xylanase-positive. Protease was best produced by isolate PF103. The results indicate that there is a significant richness of endophytic fungi in O. ficus-indica, and that these isolates indicate promising potential for deployment in biotechnological processes involving production of pectinases, cellulases, xylanases and proteases.

Isolation of cellulolytic fungi from waste of castor (Ricinus communis L.).

This is the first report of isolation of fungi present in fatty and defatted castor bean meal as well as the first of crop's selection to test the cellulolytic potential, in order to verify the diversity and potential of cellulolytic fungi in castor bean waste (Ricinus communis L.). For the screening on solid medium, it was used carboxymethylcellulose (CMC) as the sole carbon source. The microcrystalline cellulose (Avicel) was used as a substrate for submerged fermentation for production of cellobiohydrolase (FPase) and the CMC to produce endoglucanases (CMCase) and ß-glycosidases (BG). 189 cultures of fungi were isolated, including 40 species of filamentous fungi and three yeasts. The Aspergillus was the most frequent found genus. Regarding the distribution of isolated species from defatted castor bean meal, the A. niger was the most frequent one; and within the fatty castor bean meal, the Emericela variecolor prevailed among other species. Among the 67 fungal cultures tested in the initial screening on solid media to assess the cellulolytic potential, 54 disclosed Cellulolytic Index (CI) ranging from 1.04 to 6.00 mm. The isolates were selected for enzyme production in liquid medium with values above 2.0 CI. They were obtained with A. japonicus URM5620 FPase activity (4.99 U/ml) and BG (0.05 U/ml), and Rhodotorula glutinis URM5724 activity of CMCase 3.58 U/ml. These cases occurred after 168 h of submersion for both species of fungi. In our study, we could conclude that the castor bean is a promising source of fungi capable of producing cellulolytic enzymes.

Crude glycerin in the supplementation of crossbred heifers in tropical pastures.

Crude glycerin (CG) is a biodiesel byproduct that has been tested as an alternative feed additive for use in beef production. After being absorbed, it is used in the liver to produce glucose, an important precursor of intramuscular fat in ruminants. This study aimed to evaluate the effect of CG (439 g/kg glycerol) on the performance and meat quality of crossbred heifers finished in Urochloa brizantha cv. Marandu. Thirty-six heifers with an initial BW of 301.5 ±â€¯23.02 kg were used. They were supplemented for 154 days with the following levels of CG: mineral mixture (without CG), 33.3, 66.6 and 99.9 g/kg CG in the DM of the supplement. Supplement or pasture DM intakes, slaughter BW and carcass traits were not influenced (P > 0.05) by increasing levels of CG. The total fat content of the meat, the vaccenic (18:1 n-7t) and conjugated linoleic acid (18:2 c9-t11) increased with the addition of CG in the diet (P < 0.05). Crude glycerin can be included up to 99.9 g/kg of the total diet without changing the performance of crossbred heifers finished in the tropical pasture.

Haemophilus ducreyi detection by polymerase chain reaction in oesophageal lesions of HIV patients.

HIV patients frequently have opportunistic oesophageal infections. We report Haemophilus ducreyi genetic material detected by polymerase chain reaction in biopsies of oesophageal lesions in three HIV-1-infected patients. This finding may be an indication of its aetiopathological role in oesophageal lesions of HIV patients.

Developmental regulation of phospholipid secretion by fetal type II pneumocytes.

Surfactant sufficiency is dependent upon adequate synthesis and secretion of surfactant by the type II alveolar epithelium. Our laboratory has previously shown that basal secretion of surfactant phospholipid by differentiated fetal type II cells is lower than the basal secretion by adult cells. The purposes of this study were to determine if undifferentiated fetal type II cells can secrete phosphatidylcholine, to determine if terbutaline, a beta-adrenergic agonist, stimulates secretion of surfactant phospholipids by undifferentiated fetal cells and to examine the effects of differentiation on secretion of surfactant phospholipids by fetal cells. Constitutive (basal) secretion of phosphatidylcholine increased linearly as a function of time in both undifferentiated and differentiated cells, but the rate of secretion was greater in differentiated cells than the rate of secretion in undifferentiated cells. Terbutaline caused a concentration-dependent increase in secretion in both undifferentiated and differentiated cells. Maximal effective concentration and EC50 were similar for undifferentiated (10(-6) M, 0.2 microM) and differentiated (10(-5) M, 0.3 microM) cells. The relative stimulation of secretion above control values was greater for undifferentiated cells. The kinetics of terbutaline stimulation varied significantly with cellular differentiation. Terbutaline resulted in 230% stimulation of secretion in undifferentiated cells at 30 min followed by a decline in the response to terbutaline at 60 to 120 min. In contrast, terbutaline stimulated secretion by differentiated cells showed a sustained linear increase from 0 to 120 min. This regulation of stimulated secretion is not present in undifferentiated cells. We conclude that undifferentiated type II cells are capable of the secretion of phosphatidylcholine and that terbutaline stimulates secretion by undifferentiated cells. Furthermore, basal secretion increases as a function of differentiation of type II cells and the regulation of stimulated secretion seen in differentiated cells is not developed in undifferentiated cells. The developmental regulation of the secretion of surfactant is complex and probably involves both excitatory as well as inhibitory mechanisms which develop at different stages of differentiation of the type II cell.

Reutilization of surfactant phosphatidylglycerol and lysophosphatidylcholine by adult rabbits.

Adult rabbits reutilize the phosphatidylcholine (PC) of surfactant much less efficiently than developing rabbits (22% vs. 95%). Comparisons of reutilization efficiency of other components of surfactant in adult rabbits have not been determined. We injected adult rabbits intratracheally with [3H]dipalmitoylphosphatidylcholine (DPPG) mixed with [14C]lysophosphatidylcholine (lysoPC) and natural surfactant or [14C]DPPC mixed with [3H]dipalmitoylphosphatidylglycerol (DPPG) and natural surfactant. Recovery in the alveolar wash and lamellar bodies of labelled DPPC, lysoPC and DPPG was determined at different times after injection. By plotting the ratio of [3H]DPPG to [14C]DPPC in the alveolar wash versus time after injection we found that phosphatidylglycerol was reutilized with an efficiency of only 0-7% which was much less than the reutilization of PC in these animals. At early times after injection, adult rabbits injected with [14C]lysoPC had a ratio of [14C]PC in their alveolar wash to lamellar bodies that was larger than 1.0. By comparison, 3-day old rabbits injected intratracheally with [14C]lysoPC had a ratio of [14C]PC in alveolar wash to lamellar bodies less than 1.0 at the earliest times measurable. Thus adult rabbits demonstrate a pathway for accumulation of PC in their alveolar space prior to its appearance in lamellar bodies. This was not detected in developing rabbits. As in developing rabbits, adult rabbits reutilize the phosphatidylglycerol of surfactant less efficiently than the PC of surfactant.

Molecular epidemiology of type 1 and 2 dengue viruses in Brazil from 1988 to 2001.

Dengue is a mosquito-borne viral infection that in recent decades has become a major international public health concern. Epidemic dengue fever reemerged in Brazil in 1981. Since 1990 more than one dengue virus serotype has been circulating in this tropical country and increasing rates of dengue hemorrhagic fever and dengue shock syndrome have been detected every year. Some evidence supports the association between the introduction of a new serotype and/or genotype in a region and the appearance of dengue hemorrhagic fever. In order to study the evolutionary relationships and possible detection of the introduction of new dengue virus genotypes in Brazil in the last years, we analyzed partial nucleotide sequences of 52 Brazilian samples of both dengue type 1 and dengue type 2 isolated from 1988 to 2001 from highly endemic regions. A 240-nucleotide-long sequence from the envelope/nonstructural protein 1 gene junction was used for phylogenetic analysis. After comparing the nucleotide sequences originally obtained in this study to those previously studied by others, and analyzing the phylogenetic trees, we conclude that, after the initial introduction of the currently circulating dengue-1 and dengue-2 genotypes in Brazil, there has been no evidence of introduction of new genotypes since 1988. The increasing number of dengue hemorrhagic fever cases seen in Brazil in the last years is probably associated with secondary infections or with the introduction of new serotypes but not with the introduction of new genotypes.

Surface tension and pulmonary compliance in premature rabbits.

In vitro surface properties of pulmonary surfactant thought to be essential to its ability to increase pulmonary compliance include minimum surface tension less than 10 dyn/cm and large surface tension variability and hysteresis. We tested four surface-active agents (Tween 20, a detergent; and FC-100, FC-430, and FC-431, industrial fluorocarbons), all lacking these properties, for their ability to increase pulmonary compliance in surfactant-deficient premature rabbits. Fetal rabbits were delivered by cesarean section at 27 days (full term = 31 days) and injected via tracheostomy with 50% lactated Ringer solution, adult rabbit surfactant, or one of the four experimental agents. Dynamic compliance was measured using 1 h of mechanical ventilation followed by alveolar lavage. Each experimental agent produced a dynamic compliance significantly higher than 50% lactated Ringer solution and statistically equal to or greater than natural surfactant. Equilibrium surface tension of the agents and minimum and equilibrium surface tension of the alveolar washes each correlated with compliance (P less than 0.05). This suggests that some surface properties of pulmonary surfactant believed to be essential are not, although surface tension does seem to play a role in pulmonary compliance.

Comparison of techniques for extracting viral RNA from isolation-negative serum for dengue diagnosis by the polymerase chain reaction.

Aiming at the improvement of the molecular diagnosis of dengue, three well-established methods of RNA extraction from serum of patients with clinical symptoms of dengue were compared. The methods were based on the QIAamp Viral RNA kit, the Chomczynski-Sacchi technique and TRIzol. One hundred samples were examined using the same protocol for reverse transcription-polymerase chain reaction (RT-PCR). Out of the 100 samples tested, none was positive by either the Chomczynski-Sacchi technique or TRIzol, and six were positive using the QIAamp viral RNA kit. Of the six positive samples, only one was collected before 5 days of the beginning of the disease, and it was also positive for viral isolation. These results were confirmed later by serology (MAC-ELISA) that showed that 19 samples were positive for IgM antibodies against dengue. These data indicate that PCR is a useful method for detection of dengue virus infections in IgM-positive samples, and the best method of RNA extraction from clinical samples, to be used for dengue diagnosis by PCR is the QIAamp Viral RNA kit.

Evaluation of the enzyme-linked-immuno-electro-diffusion-assay (ELIEDA) for the diagnosis of Schistosoma mansoni infection with low worm burden.

An immunoprecipitation technique, ELIEDA (enzyme-linked-immuno-electro-diffusion assay), was evaluated for the diagnosis of Schistosoma mansoni infection with low worm burden. One hundred of serum samples from patients excreting less than 600 eggs per gram of feces (epg), with unrelated diseases and clinically healthy subjects were studied. In patients with egg counts higher than 200 epg, the sensitivities of IgM and IgG ELIEDA were 1,000 and 0.923, respectively, not differing from other serologic techniques, such as indirect hemaglutination (IHAT), immunofluorescence (IFT) tests and immuno-electrodiffusion assay (IEDA). However in patients with low egg counts (< 100 epg), the IgG ELIEDA provided better results (0.821) than IgM ELIEDA (0.679), showing sensitivity that did not differ from that of IgG IFT (0.929), but lower than that of IgM IFT (0.964). However, its sensitivity was higher than that found with IHAT (0.607) and IEDA (0.536). The specificity of IgG ELIEDA was comparable to that of other techniques. The data indicate that IgG ELIEDA might be useful for the diagnosis of slight S. mansoni infections, and the cellulose acetate membrane strips can be stored for further retrospective studies.

Decay of antibody isotypes against early developmental stages of Schistosoma mansoni after treatment of schistosomiasis patients.

Antibodies to a number of parasite antigens are found in schistosomiasis patients, and antibodies to early developmental stages were demonstrated to be efficient immunologic markers for the diagnosis of schistosomiasis. In the present study, decay patterns of IgM and IgG antibodies against cercariae and schistosomula were investigated, in comparison to antibodies against worms and eggs in schistosomiasis patients after chemotherapy, for an investigation of seroepidemiologic aspects. Data obtained in the study of 359 serum samples from patients with Schistosoma mansoni infection, noninfected individuals, and patients followed-up for a period of 12 to 15 months after treatment provided the basis to postulate a general pattern for the kinetics of antibody decay. Before treatment, the antibody pattern was represented by a unimodal curve, which shifted to a bimodal curve after treatment, and ended with a unimodal curve similar to that for the noninfected group. Different types of antibodies were classified into four categories according to their decay features, and anti-schistosomulum IgM was classified into the moderate-decay category, whereas other antibodies to early parasite stages were classified into the slow-decay category. The present methodology permits the identification of the most suitable antibodies to be detected in field control programs for schistosomiasis or other parasitoses.

Liver morphology with emphasis on bile ducts changes and survival analysis in mice submitted to multiple Schistosoma mansoni infections and chemotherapy.

In an attempt to be as close as possible to the infected and treated patients of the endemic areas of schistosomiasis (S. mansoni) and in order to achieve a long period of follow-up, mice were repeatedly infected with a low number of cercariae. Survival data and histological variables such as schistosomal granuloma, portal changes, hepatocellular necrosis, hepatocellular regeneration, schistosomotic pigment, periductal fibrosis and chiefly bile ducts changes were analysed in the infected treated and non treated mice. Oxamniquine chemotherapy in repeatedly infected mice prolonged survival significantly when compared to non-treated animals (chi-square 9.24, p = 0.0024), thus confirming previous results with a similar experimental model but with a shorter term follow-up. Furthermore, mortality decreased rapidly after treatment suggesting an abrupt reduction in the severity of hepatic lesions. A morphological and immunohistochemical study of the liver was carried out. Portal fibrosis, with a pattern resembling human Symmers fibrosis was present at a late phase in the infected animals. Bile duct lesions were quite close to those described in human Mansonian schistosomiasis. Schistosomal antigen was observed in one isolated altered bile duct cell. The pathogenesis of the bile duct changes and its relation to the parasite infection and/or their antigens are discussed.

[Immunodiagnosis of schistosomiasis mansoni with a low parasitic load]. / Imunodiagnóstico da esquistossomose mansônica com baixa carga parasitária.

Presently, the schistosomiasis mansoni with low worm burden is frequent, thus immunologic assays of interest for the field diagnosis of Schistosoma mansoni light infections were evaluated here. Assays not assessed before (group I) and those requiring better validation (group II) for the screening of light infections were included in this study. In the group I, the immunofluorescence assays for the detection of IgM antibodies to worm antigens (IgM IFAw) and IgG antibodies to egg antigens (IgG IFAe) gave high levels of sensitivity, specificity, efficiency and predictive value of positive. However, the immunoenzymatic assays for the detection of IgM antibodies to worm antigens (IgM ELISAw) and to egg antigens (IgM ELISAe) had lower levels than the former assays. The assays from the group II designed mostly for the detection of IgG antibodies to same parasite antigens showed good diagnostic performance. The data obtained here contributed to evidenciate at least three category of immunoassays, and we concluded that those from the category I are suitable for seroepidemiologic purposes by keeping their diagnostic features unchanged even varying significantly the intensity of S. mansoni infection.

Effect of organic loading rate and fill time on the biohydrogen production in a mechanically stirred AnSBBR treating synthetic sucrose-based wastewater.

This study investigated the feasibility to produce biohydrogen of a mechanically stirred anaerobic sequencing batch biofilm reactor (AnSBBR) treating sucrose-based synthetic wastewater. The bioreactor performance (30 °C) was evaluated as to the combined effect of fill time (2, 1.5, and 1 h), cycle length (4, 3, and 2 h), influent concentration (3,500 and 5,250 mg chemical oxygen demand (COD) L(-1)) and applied volumetric organic load (AVOLCT from 9.0 to 27.0 g COD L(-1) d(-1)). AVOLs were varied according to influent concentration and cycle length (t C). The results showed that increasing AVOLCT resulted in a decrease in sucrose removal from 99 to 86 % and in improvement of molar yield per removed load (MYRLS.n) from 1.02 mol H2 mol carbohydrate(-1) at AVOLCT of 9.0 g COD L(-1) d(-1) to maximum value of 1.48 mol H2 mol carbohydrate(-1), at AVOLCT of 18.0 g COD L(-1) d(-1), with subsequent decrease. Increasing AVOLCT improved the daily molar productivity of hydrogen (MPr) from 15.28 to 49.22 mol H2 m(-3) d(-1). The highest daily specific molar productivity of hydrogen (SMPr) obtained was 8.71 mol H2 kg TVS(-1) d(-1) at an AVOLCT of 18.0 g COD L(-1) d(-1). Decreasing t C from 4 to 3 h decreased sucrose removal, increased MPr, and improved SMPr. Increasing influent concentration decreased sucrose removal only at t C of 2 h, improved MYRLS,n and MPr at all t C, and also improved SMPr at t C of 4 and 3 h. Feeding strategy had a significant effect on biohydrogen production; increasing fill time improved sucrose removal, MPr, SMPr, and MYRLS,n for all investigated AVOLCT. At all operational conditions, the main intermediate metabolic was acetic acid followed by ethanol, butyric, and propionic acids. Increasing fill time resulted in a decrease in ethanol concentration.

Effect of different cryo-protectants on the viability of frozen/thawed semen from boars of the Piau breed.

The objective of this study was to evaluate the effect of different cryo-protectants (glycerol, dimethylacetamide and dimethylformamide alone or combined and added to lactose-egg yolk extender) on the viability of frozen/thawed semen from the Piau breed as assessed by in vitro testing. Frozen semen samples (n=20) were used from five male swine. Five different freezing extenders, including 2% glycerol (Group 1 - G), 2% glycerol and 3% dimethylacetamide (Group 2 - GA), 2% glycerol and 3% dimethylformamide (Group 3 - GF), 5% dimethylacetamide (Group 4 - A) and 5% dimethylformamide (group 5 - F), were evaluated. To assess post-thawing sperm quality, sperm motility and morphology were evaluated. Sperm viability was determined using the hypoosmotic swelling test, supravital staining, and a fluorescent assay (carboxyfluorescein diacetate and propidium iodide). The mean total sperm motility of semen immediately after thawing was 46.2±1.3, 57.7±1.5, 53.2±2.1, 51.7±1.2, and 46.5±1.6% for groups 1-5, respectively. Groups 2 (GA) and 3 (GF) had greater motility values (P<0.05). Fluorescent assay values of 22.3±2.3%, 35.2±3.7%, 30.8±3.4%, 36.6±3.7%, and 26.5±3.8% were obtained for Groups 1-5, respectively, showing that Group 4 (A) sperm had greater viability than those from Group 1 (G), although there was no differences between the other treatments (P>0.05). The other complementary tests (hypoosmotic swelling test and supra-vital staining) demonstrated that sperm in Groups 2 (GA), 3 (GF) and 4 (A) had the greatest viability and there were no significant differences among these three groups (P>0.05). The most effective cryo-protectant combinations likely minimized and controlled the deleterious processes that occur in the sperm cell during freezing/thawing, thus improving post-thawing sperm viability. In conclusion, the combination of amides (3%) and glycerol (2%) or dimethylacetamide (5%) alone were more efficient at cryo-protection than glycerol alone for semen freezing in the Piau swine breed.

The role of the SLAM-SAP signaling pathway in the modulation of CD4+ T cell responses.

The signaling lymphocytic activation molecule (SLAM), present on the surface of hematopoietic cells, can regulate some events of the immune responses. This modulatory action is associated with the capacity of SLAM to interact with an intracytoplasmic adapter, such as SLAM-associated protein (SAP). SLAM is constitutively expressed in most of these cells, is rapidly induced after antigenic or inflammatory stimuli, and participates in the immunological synapse. Defects in the function of the SLAM-SAP pathway contribute to immunological abnormalities, resulting in autoimmune diseases, tumors of the lymphoid tissues and inadequate responses to infectious agents. Initially, the role of SLAM was investigated using an anti-SLAM monoclonal antibody (α-SLAM mAb) identified as an agonist of the SLAM-SAP pathway, which could induce the production of interferon-γ and could redirect the immune response to a T helper 1 (Th1) cell profile. However, in this review we postulate that the SLAM-SAP pathway primarily induces a Th2 response and secondarily suppresses the Th1 response.