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971.
Valérie Mitchell Marie-Claire Peers Carole Marchetti Maryse Leroy Jean -Marc Rigot Jean -Jacques Lafitte Alexandre Moerman Denise Escalier 《Andrologie》2008,18(1):35-45
Conventional semen analysis (sperm count) is limited to examination of spermatozoa at a magnification of x1,000, which may be insufficient in rare situations. Electron microscopy sperm examination allows high-power (x 100,000) analysis of sperm organelles and quantification of abnormalities of the constituents involved in sperm mobility and fertility potential. Electron microscopy sperm morphology examination is rarely indicated and is reserved to: 1) severe monomorphic and stable teratospermia (globozoospermia = spermatozoa with a round head and no acrosome, pinheads = decapitated spermatozoa), 2) partial (asthenospermia) or total (akinetospermia) alteration of sperm mobility and/or quality of sperm movement. All of these anomalies are associated with primary infertility. Globozoospermia and pinheads can be detected by light microscopy. Electron microscopy sperm morphology examination precisely identifies and quantifies sperm abnormalities. Pathological phenotypes have a heterogeneous expression. The organelles of spermatozoa other than those primarily involved in the pathological phenotype may also present alterations. Globozoospermia is generally characterized by the absence of elongation of the nucleus, and absence of the acrosome and the post-acrosomal region. The implantation fossa and basal plate are generally missing in decapitated spermatozoa. Asthenospermia may be an indication for electron microscopy sperm examination when it is not associated with necrospermia. Sperm with fibrous sheath dysplasia (FSD) generally present a short flagella and very low overall mobility, less than 5%. The various phenotypes are characterized by abnormal arrangements of the constituents of the fibrous sheath and 20% of patients also present respiratory tract disease. In primary ciliary dyskinesia (PCD), spermatozoa are often immobile and present a normal morphology on light microscopy. Apart from the complete form with absent axoneme, incomplete forms are also observed with absence of the dynein arms, peripheral doublets, microtubules. These phenotypes have a low prevalence in the population of infertile men. A familial incidence, parental consanguinity, and a high incidence in certain geographical regions are frequently reported, suggesting the existence of one or several genetic mechanisms. Despite the limited state of knowledge at the present time, couples must be informed about the possible transmission of the phenotype to their descendants. All men with these phenotypes are spontaneously infertile. The only alternative fertilization technique is intracytoplasmic sperm injection (ICSI). According to the literature and our own experience, the results of ICSI with sperm presenting these phenotypes are poorer than those of ICSI in general. Electron microscopy is not only a diagnostic tool in severe male infertility, but also a prognostic indicator of the success of management by ICSI, which must be evaluated for each case. 相似文献
972.
Hyewon Youn - Current address: Institute of Biomedical Sciences School of Medicine Inha University Jungsuck B/D - rd St. ShinHeung-Dong Choong-Gu Inchon - Korea Keejong Hong Jin-Wook Yoo Chi H. Lee 《Biomarkers》2008,13(3):257-269
This study aimed to elucidate the mechanisms that may lead to an efficient strategy to induce a suitable host response of the vaginal mucosa upon exposure to intravaginally delivered exogenous compounds. It was hypothesized that the upregulation of intercellular adhesion molecule (ICAM)-1 gene expression may reflect the inflammatory response evoked by exogenous compounds. Major emphasis was placed on ethylenediamine tetraacetic acid (EDTA) which was added as a synergistic agent to conventional spermicidal agents or anti-HIV drugs. The levels of ICAM-1 mRNA were examined as a surrogate marker for inflammatory response in human vaginal epithelial cells upon exposure to EDTA or interleukin (IL)-1β (i.e. positive control, 25 mM). The effects of estrogen on EDTA-induced ICAM-1 expression were also evaluated for the estrogen involvement in the inflammatory process of the vaginal mucosa. ICAM-1 expression in human vaginal cells (VK2/E6E7 cells) increased as EDTA concentration added to human vaginal cell lines increased. The effects of estrogen on EDTA-induced ICAM-1 expression in human vaginal epithelial cells were estrogen-concentration dependent; estrogen at lower concentrations (∼1-10 nM) did not affect ICAM-1 expression, whereas estrogen at higher concentrations (∼100 nM-1 µM) attenuated ICAM-1 expression. The influence of estrogen in ICAM-1 expression suggests the beneficial effects of estrogen on the regulation of vaginal homeostasis. Identification and quantification of specific surrogate markers for the inflammatory response evoked by exogenous compounds and their regulation by estrogen will lead to an efficient strategy against sexually transmitted diseases including AIDS. 相似文献
973.
Laura Toppino Giampiero Valè Giuseppe Leonardo Rotino 《Molecular breeding : new strategies in plant improvement》2008,22(2):237-250
The two eggplant relatives Solanum aethiopicum gr. Gilo and Solanum aethiopicum gr. Aculeatum (=Solanum integrifolium) carry resistance to the fungal wilt disease caused by Fusarium oxysporum f. sp. melongenae, a worldwide soil-borne disease of eggplant. To introgress the resistance trait into cultivated eggplant, the tetraploid
somatic hybrids S. melongena + S. aethiopicum and S. melongena + S.
integrifolium were used. An inheritance study of the resistance was performed on advanced anther culture-derived androgenetic backcross
progenies from the two somatic hybrids. The segregation fitted a 3 resistant (R): 1 susceptible (S) ratio in the selfed populations
and a 1R:1S ratio in the backcross progenies for the trait derived from S. aethiopicum and S. integrifolium. These ratios are consistent with a single gene, which we designated as Rfo-sa1, controlling the resistance to Fusarium oxysporum f. sp. melongenae. The allelic relationship between the resistance genes from S. aethiopicum and S. integrifolium indicate that these two genes are alleles of the same locus. Bulked Segregant Analysis (BSA) was performed with RAPD markers
on the BC3/BC5 resistant advanced backcross progenies, and three RAPD markers associated with the resistance trait were identified. Cleaved
Amplified Polymorphic Sequences (CAPSs) were subsequently obtained on the basis of the amplicon sequences. The evaluation
of the efficiency of these markers in predicting the resistant phenotype in segregating progenies revealed that they represent
useful tools for indirect selection of Fusarium resistance in eggplant. 相似文献
974.
Soares AR da Gama BA da Cunha AP Teixeira VL Pereira RC 《Marine biotechnology (New York, N.Y.)》2008,10(2):158-165
Marine invertebrates settle, attach, and/or metamorphose in response to signals from several sources, including seaweeds.
In response to the aquaculture challenge of producing constant numbers of juveniles from cultured species, natural inducers
have been screened for their ability to improve those processes. However, few chemical inducers of attachment of invertebrates
have been identified, and even less of these were secondary metabolites. The goal of this work was to isolate the natural
products responsible for induction activity using bioassay-guided fractionation of the organic extract of the brown seaweed
Stypopodium zonale and the attachment of juveniles of the common brown mussel, Perna perna, as a model. The meroditerpene epitaondiol, identified by comparison of spectral data with the literature, promoted as much
as 4.7 times more mussel attachment compared to controls at the natural concentration found in this alga (0.041% of the crude
extract or 0.012% of algal dry weight). This is the first report showing that a seaweed produces terpenoid compounds as cues
for invertebrate attachment, and future studies evaluating this action on settlement of mussels in the field are expected
to improve aquaculture technology by increasing mussel spat production. 相似文献
975.
Elena Simionato Pierre Kerner Nicolas Dray Martine Le Gouar Valérie Ledent Detlev Arendt Michel Vervoort 《BMC evolutionary biology》2008,8(1):170
Background
Functional studies in model organisms, such as vertebrates and Drosophila, have shown that basic Helix-loop-Helix (bHLH) proteins have important roles in different steps of neurogenesis, from the acquisition of neural fate to the differentiation into specific neural cell types. However, these studies highlighted many differences in the expression and function of orthologous bHLH proteins during neural development between vertebrates and Drosophila. To understand how the functions of neural bHLH genes have evolved among bilaterians, we have performed a detailed study of bHLH genes during nervous system development in the polychaete annelid, Platynereis dumerilii, an organism which is evolutionary distant from both Drosophila and vertebrates. 相似文献976.
977.
Loïc Le Cunff Alexandre Fournier-Level Valérie Laucou Silvia Vezzulli Thierry Lacombe Anne-Françoise Adam-Blondon Jean-Michel Boursiquot Patrice This 《BMC plant biology》2008,8(1):31
Background
The first high quality draft of the grape genome sequence has just been published. This is a critical step in accessing all the genes of this species and increases the chances of exploiting the natural genetic diversity through association genetics. However, our basic knowledge of the extent of allelic variation within the species is still not sufficient. Towards this goal, we constructed nested genetic core collections (G-cores) to capture the simple sequence repeat (SSR) diversity of the grape cultivated compartment (Vitis vinifera L. subsp. sativa) from the world's largest germplasm collection (Domaine de Vassal, INRA Hérault, France), containing 2262 unique genotypes. 相似文献978.
Didier Ménard Arsène Ratsimbasoa Milijaona Randrianarivelojosia Léon-Paul Rabarijaona Lucie Raharimalala Olivier Domarle Laurence Randrianasolo Arthur Randriamanantena Martial Jahevitra Valérie Andriantsoanirina Marie-Ange Rason Rogelin Raherinjafy Emma Rakotomalala Luciano Tuseo Andrianirina Raveloson 《Malaria journal》2008,7(1):55
Background
In order to improve the monitoring of the antimalarial drug resistance in Madagascar, a new national network based on eight sentinel sites was set up. In 2006/2007, a multi-site randomized clinical trial was designed to assess the therapeutic efficacy of chloroquine (CQ), sulphadoxine-pyrimethamine (SP), amodiaquine (AQ) and artesunate plus amodiaquine combination (ASAQ), the antimalarial therapies recommended by the National Malaria Control Programme (NMCP).Methods
Children between six months and 15 years of age, with uncomplicated falciparum malaria, were enrolled. Primary endpoints were the day-14 and day-28 risks of parasitological failure, either unadjusted or adjusted by genotyping. Risks of clinical and parasitological treatment failure after adjustment by genotyping were estimated using Kaplan-Meier survival analysis. Secondary outcomes included fever clearance, parasite clearance, change in haemoglobin levels between Day 0 and the last day of follow-up, and the incidence of adverse events.Results
A total of 1,347 of 1,434 patients (93.9%) completed treatment and follow-up to day 28. All treatment regimens, except for the chloroquine (CQ) treatment group, resulted in clinical cure rates above 97.6% by day-14 and 96.7% by day-28 (adjusted by genotyping). Parasite and fever clearance was more rapid with artesunate plus amodiaquine, but the extent of haematological recovery on day-28 did not differ significantly between the four groups. No severe side-effects were observed during the follow-up period.Conclusion
These findings (i) constitute an up-dated baseline data on the efficacy of antimalarial drugs recommended by the NMCP, (ii) show that antimalarial drug resistance remains low in Madagascar, except for CQ, compared to the bordering countries in the Indian Ocean region such as the Comoros Archipelago and (iii) support the current policy of ASAQ as the first-line treatment in uncomplicated falciparum malaria.979.
Serving as the primary conduit for communication between the nucleus and the cytoplasm, nuclear pore complexes (NPCs) impact nearly every cellular process. The extent to which NPC composition varies and the functional significance of such variation in mammalian development has not been investigated. Here we report that a null allele of mouse nucleoporin Nup133, a structural subunit of the NPC, disrupts neural differentiation. We find that expression of Nup133 is cell type and developmental stage restricted, with prominent expression in dividing progenitors. Nup133-deficient epiblast and ES cells abnormally maintain features of pluripotency and differentiate inefficiently along the neural lineage. Neural progenitors achieve correct spatial patterning in mutant embryos; however, they are impaired in generating terminally differentiated neurons, as are Nup133 null ES cells. Our results reveal a role for structural nucleoporins in coordinating cell differentiation events in the developing embryo. 相似文献
980.
Giraud A Arous S De Paepe M Gaboriau-Routhiau V Bambou JC Rakotobe S Lindner AB Taddei F Cerf-Bensussan N 《PLoS genetics》2008,4(1):e2
While pleiotropic adaptive mutations are thought to be central for evolution, little is known on the downstream molecular effects allowing adaptation to complex ecologically relevant environments. Here we show that Escherichia coli MG1655 adapts rapidly to the intestine of germ-free mice by single point mutations in EnvZ/OmpR two-component signal transduction system, which controls more than 100 genes. The selective advantage conferred by the mutations that modulate EnvZ/OmpR activities was the result of their independent and additive effects on flagellin expression and permeability. These results obtained in vivo thus suggest that global regulators may have evolved to coordinate activities that need to be fine-tuned simultaneously during adaptation to complex environments and that mutations in such regulators permit adjustment of the boundaries of physiological adaptation when switching between two very distinct environments. 相似文献