Obtención, evaluación y manipulación del semen de verraco en una unidad de producción mexicana

Córdova Izquierdo, A.; Pérez Gutiérrez, J.F.; Méndez Hernández, W.; Villa Mancera, A.E.; Huerta Crispín, R.: Obtención, evaluación y manipulación del semen de verraco en una unidad de producción mexicana. Rev. vet. 26: 1, 69-74, 201

Can bovine embryos be successfully transferred after 40 years of cryopreservation?

ABSTRACT Global advances in reproductive biotechnology have allowed for the transfer of embryos from donor females with high genetic merit to recipients using the cryopreservation technique, which preserves an embryo of excellent quality and viability, thereby achieving a feasible pregnancy rate. The objective of this study was to evaluate the quality and viability of Holstein embryos that have been cryopreserved for more than 40 years under glycerol freezing. The embryos were transferred to the recipient heifers using a non-surgical method. Two 17-month-old Holstein heifers (360 kg live weights) which were clinically healthy and reproductively active were used as the recipients. Two bovine embryos of Grade 1 quality were thawed and evaluated for their morphology. Of the two embryo transfers, one pregnancy was achieved, resulting in the birth of a calf. Therefore, embryos frozen in liquid nitrogen and glycerol as a cryopreservative for more than 40 years maintained their quality and viability to produce a live calf

Consecuencias del estrés calórico sobre la reproducción del ganado vacuno

Heat stress represents one of the major environmental factors that adversely affect the reproductive performance of cattle. In this paper the behavioral adjustments, physical mechanisms and physiological responses to heat loss are described; bos indicus adaptive advantages with respect to bos Taurus, pathophysiology of heat stress and heat stress effects in animal reproduction, both the male and the female.El estrés calórico representa unos de los principales factores del medio ambiente que repercuten negativamente en el desempeño reproductivo del ganado vacuno. En este trabajo se describen los ajustes conductuales, mecanismos físicos y respuestas fisiológicas para la pérdida calórica; ventajas adaptativas del bos indicus con respecto al bos Taurus, fisiopatología del estrés calórico y repercusiones del estrés calórico en la reproducción animal, tanto en el macho como en la hembra

Mimotopes selected with a neutralizing antibody against urease B from Helicobacter pylori induce enzyme inhibitory antibodies in mice upon vaccination

<p>Abstract</p> <p>Background</p> <p>Urease B is an important virulence factor that is required for <it>Helicobacter pylori </it>to colonise the gastric mucosa. Mouse monoclonal antibodies (mAbs) that inhibit urease B enzymatic activity will be useful as vaccines for the prevention and treatment of <it>H. pylori </it>infection. Here, we produced murine mAbs against urease B that neutralize the enzyme's activity. We mapped their epitopes by phage display libraries and investigated the immunogenicity of the selected mimotopes <it>in vivo</it>.</p> <p>Results</p> <p>The urease B gene was obtained (GenBank accession No. <ext-link ext-link-id="DQ141576" ext-link-type="gen">DQ141576</ext-link>) and the recombinant pGEX-4T-1/UreaseB protein was expressed in <it>Escherichia coli </it>as a 92-kDa recombinant fusion protein with glutathione-S-transferase (GST). Five mAbs U001-U005 were produced by a hybridoma-based technique with urease B-GST as an immunogen. Only U001 could inhibit urease B enzymatic activity. Immunoscreening via phage display libraries revealed two different mimotopes of urease B protein; EXXXHDM from ph.D.12-library and EXXXHSM from ph.D.C7C that matched the urease B proteins at 347-353 aa. The antiserum induced by selected phage clones clearly recognised the urease B protein and inhibited its enzymatic activity, which indicated that the phagotope-induced immune responses were antigen specific.</p> <p>Conclusions</p> <p>The present work demonstrated that phage-displayed mimotopes were accessible to the mouse immune system and triggered a humoral response. The urease B mimotope could provide a novel and promising approach for the development of a vaccine for the diagnosis and treatment of <it>H. pylori </it>infection.</p

Mimotopes selected with neutralizing antibodies against multiple subtypes of influenza A

<p>Abstract</p> <p>Background</p> <p>The mimotopes of viruses are considered as the good targets for vaccine design. We prepared mimotopes against multiple subtypes of influenza A and evaluate their immune responses in flu virus challenged Balb/c mice.</p> <p>Methods</p> <p>The mimotopes of influenza A including pandemic H1N1, H3N2, H2N2 and H1N1 swine-origin influenza virus were screened by peptide phage display libraries, respectively. These mimotopes were engineered in one protein as multi- epitopes in Escherichia coli (E. coli) and purified. Balb/c mice were immunized using the multi-mimotopes protein and specific antibody responses were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). The lung inflammation level was evaluated by hematoxylin and eosin (HE).</p> <p>Results</p> <p>Linear heptopeptide and dodecapeptide mimotopes were obtained for these influenza virus. The recombinant multi-mimotopes protein was a 73 kDa fusion protein. Comparing immunized infected groups with unimmunized infected subsets, significant differences were observed in the body weight loss and survival rate. The antiserum contained higher HI Ab titer against H1N1 virus and the lung inflammation level were significantly decreased in immunized infected groups.</p> <p>Conclusions</p> <p>Phage-displayed mimotopes against multiple subtypes of influenza A were accessible to the mouse immune system and triggered a humoral response to above virus.</p

Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia.

ABSTARCT: Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease. METHODS: Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique. RESULTS: In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X. CONCLUSIONS: This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis

CHEMICAL COMPOSITION OF LEGUMINOUS TREE FOLIAGE AND EFFECT OF POLYETHYLENE GLYCOL ON GAS PRODUCTION AND IN VITRO DIGESTION PARAMETERS

The objective was to determine the chemical composition, digestibility and in vitro digestion parameters in ten legume tree foliage using the in vitro gas-production method with and without polyethylene glycol (PEG). The foliages with higher protein content (P<0.001) (167.1 to 180.3 g/kg DM) were A. cochliacantha, L. esculenta, E. cyclocarpum and A. farnesiana; from the total phenols (P<0.001) (365.9 to 680.6 g/kg DM) L. divaricata, H. brasiletto and C. coriaria and condensed tannins (P<0.001) (35.4 to 88.0 g/kg DM) E. cyclocarpum, A. farnesiana, P. dulce, P. acatlense and G. sepium. The in vitro dry matter digestibility was different (P<0.001) among the foliages. The in vitro gas production (IVGP), in vitro organic matter digestibility, metabolizable energy (ME), gas yield (GY24h), short chain fatty acids (SCFA) and microbial mass production (PMM), were different (P<0.0001) among the foliage as a result of the species. The use of PEG increased (P<0.0001) IVGP, ME, GY24h and SCFA in H brasiletto, C. coriaria, L. esculenta and A. cochliacantha, but affect (P<0.0001) the partition factor and the PMM. The nutritional composition and fermentation parameters in vitro between foliages differ by effect of tree and use of PEG. It is concluded that chemical composition in the foliages affect the digestibility and fermentation parameters and use of PEG increased fermentation parameters in the foliages high in secondary compounds

Density and integral use evaluation of three leguminous trees in silvopastoral systems in the tropic of Guerrero, Mexico

ABSTRACT In the Tropic of Guerrero Mexico the distribution, the density and uses of trees Pithecellobium dulce Roxb Benth, Gliricidia sepium (Jacq) Steud, Haematoxilum brasiletto Karst were studied and its foliage was added to the diets of kids and productive response and apparent digestibility was measured. The livestock farmers have six complementary uses (firewood, poles, shade, medicinal, human consumption and artisanal). The species were identified in live fences and scattered in paddocks with densities of 4.87 trees per 100 linear meters and 1.79 trees ha-1; P. dulce was the largest size and identified from 250 to 1332 masl. The ashes (P<0.0001) and detergent fibre (P<0.01) of P. dulce (T1) had higher apparent digestibility. The feed conversion and daily weight gain of the kids were different due to the effect of foliage trees. The rectal temperature was only affected (P<0.0001) by the time of evaluation. The ruminal pH of kids was affected by time evaluation (P<0.0001) and the treatments (P<0.0003). It is concluded that the density of trees is low and could be of impact on soil fertility and the contribution of biomass for animal feed; the apparent digestibility of diets and productive response were more efficient in the animals fed with P. dulce (T1).RESUMEN En el Trópico Méxicano se estudió la distribución, densidad y usos de los árboles Pithecellobium dulce Roxb Benth, Gliricidia sepium (Jacq) Steud, Haematoxilum brasiletto Karst y se agregó su follaje a las dietas de cabritos y midió la respuesta productiva y la digestibilidad aparente. Los ganaderos dieron seis usos (leña, postes, sombra, medicinales, consumo humano y artesanal). Los árboles estuvieron en cercas vivas y dispersos en potreros con densidades de 4,87 árboles 100-1 metros lineales y 1,79 árboles ha-1; P. dulce Roxb Benth tuvo mayor talla y se localizó entre 250 a 1332 msnm. Las cenizas (P<0,0001) y fibras detergentes (P<0,01) del P. dulce (T1) fueron más digestibles. La CA y GDP entre los cabritos fueron diferentes entre tratamientos. La temperatura rectal sólo se afectó (P<0,0001) por la hora de evaluación. El pH ruminal de los cabritos fue diferente entre tiempos de evaluación (P<0,0001) y tratamientos (P<0,0003). Se concluye que la densidad de árboles es baja y podría tener un impacto sobre la fertilidad del suelo y la aportación de biomasa para la alimentación animal; La digestibilidad de las dietas y respuesta productiva fueron más eficientes en los animales alimentados con P. dulce Roxb Benth (T1)