Search results for "sperm"
showing 10 items of 658 documents
The p53 Tumor Suppressor Network Is a Key Responder to Microenvironmental Components of Chronic Inflammatory Stress
2005
Abstract Activation of the p53 network plays a central role in the inflammatory stress response associated with ulcerative colitis and may modulate cancer risk in patients afflicted with this chronic disease. Here, we describe the gene expression profiles associated with four microenvironmental components of the inflammatory response (NO•, H2O2, DNA replication arrest, and hypoxia) that result in p53 stabilization and activation. Isogenic HCT116 and HCT116 TP53−/− colon cancer cells were exposed to the NO• donor Sper/NO, H2O2, hypoxia, or hydroxyurea, and their mRNA was analyzed using oligonucleotide microarrays. Overall, 1,396 genes changed in a p53-dependent manner (P < 0.001), wit…
Dog sperm head morphometry: its diversity and evolution
2017
Dogs have been under strong artificial selection as a consequence of their relationship with man. Differences between breeds are evident that could be reflected in seminal characteristics. The present study was to evaluate differences in sperm head morphometry between seven well-defined breeds of dog: the British Bulldog, Chihuahua, German Shepherd, Labrador Retriever, Spanish Mastiff, Staffordshire Terrier, and Valencian Rat Hunting dog. Semen samples were obtained by masturbation and smears stained with Diff-Quik. Morphometric analysis (CASA-Morph) produced four size and four shape parameters. Length, Ellipticity, and Elongation showed higher differences between breeds. MANOVA revealed di…
Spermatocytes of the caddisfly Potamophylax rotundipennis (Trichoptera, Insecta): a fine structure study with emphasis on synaptonemal complex plates…
1996
Abstract Electron microscopy of ultrathin sections was used to study the restructuring of primary spermatocytes in a caddisfly, Potamophylax rotundipennis (Limnephilidae). Spindle structure was also examined using light microscopy of dividing spermatocytes lysed in a microtubule-stabilizing buffer. The bulk of pachytene spermatocytes was usual in that the nuclei contained tripartite synaptonemal complexes (SCs). The SCs were attached end-on to the inner face of the nuclear envelope and loosely surrounded by electron-dense chromatin. Cells of this type gave rise to late prophase I spermatocytes, where SCs were missing and chromatin condensation was advanced. By metaphase I, a conventional bi…
Cissampeloflavone, a chalcone-flavone dimer from Cissampelos pareira
2003
From the aerial parts of Cissampelos pareira L. (Menispermaceae), a chalcone-flavone dimer has been isolated which, mainly from NMR spectroscopic and MS data, was proved to be 2-(4-hydroxy-3-methoxyphenyl)-7-(4-methoxyphenyl)-6-(2-hydroxy-4,6-dimethoxybenzoyl)-furano[3,2-g]benzopyran-4-one. This has been assigned the trivial name cissampeloflavone. The compound has good activity against Trypanosoma cruzi and T. brucei rhodesiense and has a low toxicity to the human KB cell line.
Industrial and culinary practice effects on biologically active polyamines level in turkey meat
2021
Polyamines, including putrescine, spermidine, and spermine, are biological compounds present in nearly all food items. Their desirable physiological effects include cell division and growth. Hence, are undesirable in the diet of patients with tumor. This study aimed to assess the impact of curing agents (sodium chloride (0–2 g), sodium nitrite (0–200 ppm), sodium polyphosphate (0–0.5 g), and ascorbic acid (0–500 ppm)), cooking (frying (180°C), and boiling (100°C)) on polyamine contents in turkey breast meat using response surface methodology based on central composite design and dispersive liquid-liquid microextraction. Postprocessing changes were investigated using a high-performance liqui…
Enhancer blocking activity located near the 3′ end of the sea urchin early H2A histone gene
1997
The sea urchin early histone repeating unit contains one copy of each of the five histone genes whose coordinate expression during development is regulated by gene-specific elements. To learn how within the histone repeating unit a gene-specific activator can be prevented to communicate with the heterologous promoters, we searched for domain boundaries by using the enhancer blocking assay. We focused on the region near the 3′ end of the H2A gene where stage-specific nuclease cleavage sites appear upon silencing of the early histone genes. We demonstrated that a DNA fragment of 265 bp in length, defined as sns (for silencing nucleoprotein structure), blocked the enhancer activity of the H2A…
Lipid accumulation and metabolism in polychaete spermatogenesis: Role of the large discoidal lipoprotein
2010
In most oviparous animals, lipoprotein-mediated lipid transport plays an important role in the nutrient supply for the oocyte. In male gametes, lipids are used as energy substrates in spermatozoa but nothing is yet known about their origin and metabolism throughout spermatogenesis. The lipid profiles analyzed from different stages of male germ cell development in the marine annelid Nereis virens were found to undergo a dramatic change from primary triacylglycerides at the beginning of germ cell development to cholesterol and phospholipids at the end of development as demonstrated by HPLC with evaporative light scattering detection and mass spectrometry. The uptake of a large discoidal lipop…
PEMBEKUAN SEMEN LELE DUMBO (Clarias Gariepinus BURCHELL 1822) SEBAGAI MODEL KRIOPRESERVASI SEMEN IKAN
2010
<p><em>Effect of four types of diluents</em><em>s</em><em> and four concentration of DMSO (5%, 10%, 15% and 20%) against the motility of African catfish sperm were evaluated after storage at freezing temperatures. </em><em>The steps in preparation the 16 treatments combination of the diluents</em><em> </em><em>are </em><em>preparation of diluents, mixing </em><em>diluents </em><em>with DMSO, packing </em><em>of semen </em><em>in</em><em>to</em><em> 0.3-ml straw, equilibration of </em><em>semen </em><em>at 4 °C for…
Bioaccessibility and decomposition of cylindrospermopsin in vegetables matrices after the application of an in vitro digestion model.
2018
Research on the human exposure to Cylindrospermopsin (CYN) via consumption of contaminated food is of great interest for risk assessment purposes. The aim of this work is to evaluate for the first time the CYN bioaccessibility in contaminated vegetables (uncooked lettuce and spinach, and boiled spinach) after an in vitro digestion model, including the salivar, gastric and duodenal phases and, colonic fermentation under lactic acid bacteria. The results obtained showed that the digestion processes are able to diminish CYN levels, mainly in the colonic phase, especially in combination with the boiling treatment, decreasing CYN levels in a significant way. Moreover, the potential decomposition…
Structure of mammalian plasma fetuin-B and its mechanism of selective metallopeptidase inhibition
2018
The co-crystal structure of the metallopeptidase astacin with its specific protein inhibitor fetuin-B reveals a novel mechanism of inhibition.