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51.
French AR Sjölin H Kim S Koka R Yang L Young DA Cerboni C Tomasello E Ma A Vivier E Kärre K Yokoyama WM 《Journal of immunology (Baltimore, Md. : 1950)》2006,177(8):4981-4990
NK cells vigorously proliferate during viral infections. During the course of murine CMV infection, this response becomes dominated by the preferential proliferation of NK cells that express the activation receptor Ly49H. The factors driving such selective NK cell proliferation have not been characterized. In this study, we demonstrate that preferential NK cell proliferation is dependent on DAP12-mediated signaling following the binding of Ly49H to its virally encoded ligand, m157. Ly49H signaling through DAP12 appears to directly augment NK cell sensitivity to low concentrations of proproliferative cytokines such as IL-15. The impact of Ly49H-mediated signaling on NK cell proliferation is masked in the presence of high concentrations of proproliferative cytokines that nonselectively drive all NK cells to proliferate. 相似文献
52.
Cytogenetic and molecular analysis of male infertility 总被引:1,自引:0,他引:1
Reduced male fertility and subfertility can be caused by genetic factors that affect both germ cell development, differentiation, and function; in particular, chromosome abnormalities and Yq microdeletions are a possible cause of spermatogenetic impairment in males as shown by their higher frequency in infertile men than in the general male population. Microdeletion of the long arm of the Y chromosome (Yq) are associated with spermatogenic failure and have been used to define three regions on Yq (AZFa, AZFb, and AZFc) that are critical for germ cell development. With the advent of assisted reproductive technology and intracytoplasmic sperm injection, knowledge about the various factors leading to spermatogenic impairment is one of the most important aspects of scientific research. Therefore, this study was designed to identify the frequency of cytogenetic and submicroscopic interstitial deletions in azoospermia factor loci in infertile Indian males. One hundred and eighty males with nonobstructive oligozoospermia and azoospermia were included in this study. Semen analysis was done in each case to determine the spermatogenic status. Individuals were subjected to detailed clinical examination, family history, and endocrinological and cytogenetic study after consent from the patient. Peripheral blood cultures were set up according to standard protocols and 30 G-banded metaphases were analyzed in each case. Numerical and structural chromosomal abnormalities were detected in 40 infertile cases. Fluorescence in situ hybridization analysis was done in some cases to identify the percentage of mosaic cell lines and any cryptic or low-level mosaicism. Polymerase chain reaction microdeletion analysis was done in 140 cytogenetically normal cases. Of the 140 cases, 8 showed deletion of at least one of the sequence-tagged site markers. Review of literature has shown that the overall frequency of microdeletions varies from 1 to 55%. In the present study, the frequency of microdeletion was 5.8%, and deletions were identified in cases with undescended testis and varicocele and cases with bilateral severe testiculopathy. 相似文献
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R Klimaviciute J Bendoraitiene R Rutkaite J Siugzdaite A Zemaitaitis 《International journal of biological macromolecules》2012,51(5):800-807
Cationic cross-linked starch (CCS)-iodine complexes containing different amounts of quaternary ammonium groups (different degrees of substitution (DS)) and iodine have been obtained by iodine adsorption on CCS from aqueous iodine potassium iodide solution. Equilibrium adsorption studies showed that with an increase of DS the amount of iodine adsorbed on CCS and the affinity of iodine to CCS increased linearly. The influences of the DS of CCS and the amount of adsorbed iodine on the stability of CCS-iodine complexes in a solution of 0.02M sodium acetate and reactivity toward l-tyrosine have been investigated. At the same DS, the stability of CCS-iodine complexes decreased with an increase of the amount of adsorbed iodine. With increasing the DS, the stability of CCS-iodine complexes increased. The iodine consumption in the reaction with l-tyrosine increased significantly with an increase of the amount of adsorbed iodine. The influence of DS on iodine consumption was lower and depended on the amount of adsorbed iodine. The antibacterial activity of CCS-iodine complexes against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli was determined by the broth-dilution and spread-plate methods. The obtained results have demonstrated that an appropriate selection of the CCS-iodine complex composition (the DS of CCS and the amount of adsorbed iodine) could ensure good antimicrobial properties by keeping a low concentration of free iodine in the system. The main advantage of using CCS-iodine complexes as antimicrobial agents is the biodegradability of the polymeric matrix. 相似文献
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D Coggon G Ntani KT Palmer VE Felli R Harari LH Barrero SA Felknor D Gimeno A Cattrell C Serra M Bonzini E Solidaki E Merisalu RR Habib F Sadeghian M Kadir SS Warnakulasuriya K Matsudaira B Nyantumbu MR Sim H Harcombe K Cox MH Marziale LM Sarquis F Harari R Freire N Harari MV Monroy LA Quintana M Rojas EJ Salazar Vega EC Harris S Vargas-Prada JM Martinez G Delclos FG Benavides M Carugno MM Ferrario AC Pesatori L Chatzi P Bitsios M Kogevinas K Oha T Sirk A Sadeghian RJ Peiris-John N Sathiakumar 《PloS one》2012,7(7):e39820
Background
The CUPID (Cultural and Psychosocial Influences on Disability) study was established to explore the hypothesis that common musculoskeletal disorders (MSDs) and associated disability are importantly influenced by culturally determined health beliefs and expectations. This paper describes the methods of data collection and various characteristics of the study sample.Methods/Principal Findings
A standardised questionnaire covering musculoskeletal symptoms, disability and potential risk factors, was used to collect information from 47 samples of nurses, office workers, and other (mostly manual) workers in 18 countries from six continents. In addition, local investigators provided data on economic aspects of employment for each occupational group. Participation exceeded 80% in 33 of the 47 occupational groups, and after pre-specified exclusions, analysis was based on 12,426 subjects (92 to 1018 per occupational group). As expected, there was high usage of computer keyboards by office workers, while nurses had the highest prevalence of heavy manual lifting in all but one country. There was substantial heterogeneity between occupational groups in economic and psychosocial aspects of work; three- to five-fold variation in awareness of someone outside work with musculoskeletal pain; and more than ten-fold variation in the prevalence of adverse health beliefs about back and arm pain, and in awareness of terms such as “repetitive strain injury” (RSI).Conclusions/Significance
The large differences in psychosocial risk factors (including knowledge and beliefs about MSDs) between occupational groups should allow the study hypothesis to be addressed effectively. 相似文献58.
K Zibara R Hamdan L Dib S Sindet-Pedersen M Kharfan-Dabaja A Bazarbachi M El-Sabban 《PloS one》2012,7(7):e40140
Hematopoietic stem cells (HSC) derived from cord blood (CB), bone marrow (BM), or mobilized peripheral blood (PBSC) can differentiate into multiple lineages such as lymphoid, myeloid, erythroid cells and platelets. The local microenvironment is critical to the differentiation of HSCs and to the preservation of their phenotype in vivo. This microenvironment comprises a physical support supplied by the organ matrix as well as tissue specific cytokines, chemokines and growth factors. We investigated the effects of acellular bovine bone marrow extracts (BME) on HSC in vitro and in vivo. We observed a significant increase in the number of myeloid and erythroid colonies in CB mononuclear cells (MNC) or CB CD34+ cells cultured in methylcellulose media supplemented with BME. Similarly, in xeno-transplantation experiments, pretreatment with BME during ex-vivo culture of HSCs induced a significant increase in HSC engraftment in vivo. Indeed, we observed both an increase in the number of differentiated myeloid, lymphoid and erythroid cells and an acceleration of engraftment. These results were obtained using CB MNCs, BM MNCs or CD34(+) cells, transplanted in immuno-compromised mice (NOD/SCID or NSG). These findings establish the basis for exploring the use of BME in the expansion of CB HSC prior to HSC Transplantation. This study stresses the importance of the mechanical structure and soluble mediators present in the surrounding niche for the proper activity and differentiation of stem cells. 相似文献
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Kondakova AN Bystrova OV Shaikhutdinova RZ Ivanov SA Dentovskaya SV Shashkov AS Knirel YA Anisimov AP 《Carbohydrate research》2008,343(14):2486-2488
Structures of the O-antigens of Yersinia pseudotuberculosis O2c and O3 were reinvestigated by NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, (1)H,(13)C HSQC, and HMBC experiments. The following revised structure of the O2c tetrasaccharide repeating unit was established, which differs from the structure proposed earlier in the glycosylation pattern of the mannose residue at the branching point: where Abe stands for 3,6-dideoxy-d-xylo-hexose. The structure of the Y. pseudotuberculosis O3 antigen reported earlier was confirmed. 相似文献