46 research outputs found

    Association between fertilin beta, protamines 1 and 2 and spermatid-specific linker histone H1-like protein mRNA levels, fertilization ability of human spermatozoa, and quality of preimplantation embryos.

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    Fertilization involves a series of cellular interactions culminating in the fusion of gamete membranes, creating a zygote and then an embryo. During the process of human fertilization in vivo or in conventional in vitro fertilization (IVF), sperm must be capable of undergoing the acrosome reaction, binding to the zona pellucida (ZP), and penetrating the ZP to fuse with the oolema. The key role in this process is played by fertilin beta. Protamines and histones are the proteins that bind to sperm chromatin and contribute in chromatin remodeling during early spermiogenesis. It has been suggested that these proteins may also participate in successful fertilization and embryo development. Using reverse transcription and real-time quantitative PCR reaction (QR-PCR) methods and zygote and embryo scoring, we compared fertilin beta, protamine 1 (PRM1), protamine 2 (PRM2), spermatid-specific linker histone 1 (HILS1) mRNAs levels, in vitro fertilization ability of mature spermatozoa, and quality of embryos obtained from in vitro fertilization (IVF). We found significantly lower contents of fertilin beta transcript in spermatozoa from patients in which IVF fertilization failed (

    Evaluation of protamines 1 and 2 transcript contents in spermatozoa from asthenozoospermic men.

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    During mammalian spermatogenesis, the chromatin structure undergoes substantial condensation. The key role in this process is played by protamines 1 and 2 (PRM1, PRM2). We attempted to compare the levels of PRM1 and PRM2 transcripts in mature spermatozoa of normospermic and asthenozoospermic men. Human ejaculates from normozoospermic (n=70) and asthenozoospermic (n=100) donors were purified by centrifugation through discontinuous Percoll density gradient. RNA was isolated from spermatozoa according to the Chomczy膫膮ski and Sacchi method, treated with DNase I, and reverse-transcribed into cDNA. Using reverse transcription and real-time quantitative polymerase chain reaction analysis, we found a reduction in the levels of PRM1 and PRM2 transcripts in spermatozoa from asthenozoospermic men, as compared to controls (

    DNA barcoding and a precise morphological comparison revealed a cryptic species in the Nippolachnus piri complex (Hemiptera: Aphididae: Lachninae)

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    Nippolachnus is a small Palaearctic-Oriental genus of very characteristic aphids that live on the leaves of woody Rosaceae. One species, N. piri, has hitherto been regarded to be widely distributed and relatively polyphagous. Members of this genus are considered to be easy to recognize due to the absence of the ocular tubercle and triommatidia on the head. We conducted research on the morphology and generic characters of Nippolachnus piri complex using scanning electron microscopy (for the first time) and DNA barcoding. We analyzed N. piri populations on Pyrus and other plants (Eriobotrya, Rhaphiolepis and Sorbus) in Japan and the Republic of Korea. Specifically, a high genetic divergence value was found between the N. piri populations associated with different host plants. SEM investigation of the head capsule revealed that a triommatidium is present under the compound eye, despite their lack of an ocular tubercle. We propose Nippolachnus micromeli Shinji, 1924 stat. nov. as a cryptic species in the N. piri complex based on a morphological comparison, DNA barcoding and different host-plant associations. Illustrations and descriptions of studied species are given. Morphological keys to the apterae and alatae of all known species of the genus Nippolachnus are also provided

    Impact of GnRH analogues on oocyte/embryo quality and embryo development in in vitro fertilization/intracytoplasmic sperm injection cycles: a case control study

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    <p>Abstract</p> <p>Background</p> <p>Despite the clinical outcomes of ovarian stimulation with either GnRH-agonist or GnRH-antagonist analogues for in vitro fertilization (IVF) being well analysed, the effect of analogues on oocyte/embryo quality and embryo development is still not known in detail. The aim of this case-control study was to compare the efficacy of a multiple-dose GnRH antagonist protocol with that of the GnRH agonist long protocol with a view to oocyte and embryo quality, embryo development and IVF treatment outcome.</p> <p>Methods</p> <p>Between October 2001 and December 2008, 100 patients were stimulated with human menopausal gonadotrophin (HMG) and GnRH antagonist in their first treatment cycle for IVF or intracytoplasmic sperm injection (ICSI). One hundred combined GnRH agonist + HMG (long protocol) cycles were matched to the GnRH antagonist + HMG cycles by age, BMI, baseline FSH levels and by cause of infertility. We determined the number and quality of retrieved oocytes, the rate of early-cleavage embryos, the morphology and development of embryos, as well as clinical pregnancy rates. Statistical analysis was performed using Wilcoxon's matched pairs rank sum test and McNemar's chi-square test. P < 0.05 was considered statistically significant.</p> <p>Results</p> <p>The rate of cytoplasmic abnormalities in retrieved oocytes was significantly higher with the use of GnRH antagonist than in GnRH agonist cycles (62.1% vs. 49.9%; P < 0.01). We observed lower rate of zygotes showing normal pronuclear morphology (49.3% vs. 58.0%; P < 0.01), and higher cell-number of preembryos on day 2 after fertilization (4.28 vs. 4.03; P < 0.01) with the use of GnRH antagonist analogues. The rate of mature oocytes, rate of presence of multinucleated blastomers, amount of fragmentation in embryos and rate of early-cleaved embryos was similar in the two groups. Clinical pregnancy rate per embryo transfer was lower in the antagonist group than in the agonist group (30.8% vs. 40.4%) although this difference did not reach statistical significance (P = 0.17).</p> <p>Conclusion</p> <p>Antagonist seemed to influence favourably some parameters of early embryo development dynamics, while other morphological parameters seemed not to be altered according to GnRH analogue used for ovarian stimulation in IVF cycles.</p

    A Geometric terrain methodology for global optimization

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    Global optimization remains an important area of active research. Many macroscopic and microscopic applications in science and engineering still present formidable challenges to current global optimization techniques. In this work, a completely different, novel and general geometric framework for continuous global optimization is described. The proposed methodology is based on intelligent movement along the valleys and ridges of an appropriate objective function using downhill, local minimization calculations defined in terms of a trust region method and uphill integration of the Newton-like vector field combined with intermittent SQP corrector steps. The novel features of the proposed methodology include new rigorous mathematical definitions of valleys and ridges, the combined use of objective function and gradient surfaces to guide movement, and techniques to assist both exploration and termination. Collisions with boundaries of the feasible region, integral curve bifurcations, and the presence of non-differentiabilities are also discussed. A variety of examples are used to make key concepts clear and to demonstrate the reliability, efficiency and robustness of terrain methods for global optimization

    Update on epidemiology and control of Foot and Mouth Disease - A menace to international trade and global animal enterprise

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    Foot and mouth disease (FMD) is one of the most economically and socially devastating disease affecting animal agriculture throughout the world. This review describes economic impact of disease outbreaks, an update of recent findings in epidemiology of FMD both at International and national level and control of this disease. The etiological agent (FMD virus) is examined in detail at genetic and molecular characterization level and in terms of antigenic diversity. [Vet World 2012; 5(11.000): 694-704
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