Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P<0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.     

The primary structure and the functional domains of an elongation factor-1 alpha from Mucor racemosus

We have determined the complete nucleotide sequence for TEF-1, one of three genes coding for elongation factor (EF)-1 alpha in Mucor racemosus. The deduced EF-1 alpha protein contains 458 amino acids encoded by two exons. The presence of an intervening sequence located near the 3' end of the gene was predicted by the nucleotide sequence data and confirmed by alkaline S1 nuclease mapping. The amino acid sequence of EF-1 alpha was compared to the published amino acid sequences of EF-1 alpha proteins from Saccharomyces cerevisiae and Artemia salina. These proteins shared nearly 85% homology. A similar comparison to the functionally analogous EF-Tu from Escherichia coli revealed several regions of amino acid homology suggesting that the functional domains are conserved in elongation factors from these diverse organisms. Secondary structure predictions indicated that alpha helix and beta sheet conformations associated with the functional domains in EF-Tu are present in the same relative location in EF-1 alpha from M. racemosus. Through this comparative structural analysis we have predicted the general location of functional domains in EF-1 alpha which interact with GTP and tRNA.     

Whole-genome sequence of Stenotrophomonas maltophilia D457, a clinical isolate and a model strain

Stenotrophomonas maltophilia is an opportunistic pathogen with an environmental origin, and it is an increasingly relevant cause of nosocomial infections. Here we present the whole-genome sequence of S. maltophilia strain D457, a clinical isolate that is being used as a model for studying antibiotic resistance in this bacterial species.     

Design and synthesis of dihydrobenzofuran amides as orally bioavailable, centrally active γ-secretase modulators

We report the discovery and optimization of a novel series of dihydrobenzofuran amides as γ-secretase modulators (GSMs). Strategies for aligning in vitro potency with drug-like physicochemical properties and good microsomal stability while avoiding P-gp mediated efflux are discussed. Lead compounds such as 35 and 43 have moderate to good in vitro potency and excellent selectivity against Notch. Good oral bioavailability was achieved as well as robust brain Aβ42 lowering activity at 100 mg/kg po dose.     

A novel model of demyelinating encephalomyelitis induced by monocytes and dendritic cells

Local inflammation may be a precipitating event in autoimmune processes. In this study, we demonstrate that regulated influx of monocytes and dendritic cells (DC) into the CNS causes an acute neurological syndrome that results in a demyelinating encephalomyelitis. Expansion of monocytes and DC by conditional expression of Flt3 ligand in animals expressing CCL2 in the CNS promoted parenchymal cell infiltration and ascending paralysis in 100% of the mice within 9 days of Flt3 ligand induction. Depletion of circulating monocytes and DC reduced disease incidence and severity. Unlike the classical models of experimental autoimmune encephalomyelitis, depletion of CD4+ and CD8+ T cells did not affect disease induction. T cells and demyelinating lesions were observed in the CNS at a later stage as a result of organ-specific inflammation. We propose that alterations in the numbers or function of monocytes and DC coupled to dysregulated expression of chemokines in the neural tissues, favors development of CNS autoimmune disease.     

Traditional Management and Morphological Patterns of <Emphasis Type="Italic">Myrtillocactus schenckii</Emphasis> (Cactaceae) in the Tehuacán Valley,Central Mexico<Superscript>1</Superscript>

Traditional Management and Morphological Patterns of Myrtillocactus schenckii (Cactaceae) in the Tehuacán Valley, Central Mexico Myrtillocactus schenckii is a columnar cactus endemic to central México and appreciated for its edible fruit. In the Tehuacán Valley it occurs wild in thorn-scrub forests, but it is also under silviculture management—tolerate in agroforestry systems and cultivated in home gardens. Ethnobotanical and morphometric studies were conducted to document its use and management forms, as well as consequences of artificial selection on morphological patterns in managed populations. In silviculture populations artificial selection occurs through selective tolerance of the phenotypes producing more, larger, and sweeter fruits, whereas in home gardens people plant branches of the preferred phenotypes. Morphological differences were found especially in fruit size and production, the main targets of artificial selection. The highest average values of fruit size and production were found in cultivated populations (0.993 cm³ and 204.45 fruits per branch, respectively), intermediate in silviculture populations (0.819 cm³ and 70.63 fruits per branch), and the lowest in the wild (0.68 cm³ and 59.75 fruits per branch). Multivariate statistical analyses differentiated populations according to their management type. Morphological diversity was higher in managed populations (0.703 ± 0.029 and 0.679 ± 0.019 in silviculture and cultivated populations, respectively) than in the wild (0.652 ± 0.016). Managed plants of M. schenckii do not show signs of depending on humans for survival and reproduction and, therefore, domestication should be considered incipient.