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31.
32.
Berhooz Rajabalitabar Hung Anh Nguyen Herv Cheradame 《Macromolecular chemistry and physics.》1995,196(11):3597-3604
Polymerizations of 2-methylpropene (MP) initiated by the system 1,4-bis(1-azido-1-methylethyl)benzene (DAMEB)/BCl3 in the presence of DMSO were carried out by “all monomer in” (AMI) technique at ?70°C in CH2Cl2 solution. FT-IR, 1H NMR and SEC analyses of polymers (PMP) showed that the M n versus weight of PMP plot is a straight line without intercept and azide Fn3 and aromatic ring F? functionalities are close to the theoretical values of 2 and 1, respectively. A polymerization of MP initiated by the system α,ω-diazido-PMP/BCl3/DMSO led to a final poly(2-methylpropene) (PMP) with an increase of M n corresponding to the amount of MP introduced and presenting the same functionalities FN3 and F? as the starting PMP. These results indicate that the polymerization system MP/DAMEB/BCl3/DMSO is a “living” one, because in an acceptably large range of molecular weight (M n < 50000) the Mayo plot 1/DP versus 1/DP 0 is a straight line. The intercept gives ktrM/kp = 4 · 10?5, showing the transfer reaction proceeds at very low rate. 相似文献
33.
Calcium ionophore-induced acrosome reaction correlates with fertilization rates in vitro in patients with teratozoospermic semen 总被引:5,自引:3,他引:5
The aim of this study was to determine the relationship between calcium
ionophore A23187-induced acrosome reaction (AR) and sperm fertilizing
ability. Semen samples remaining after preparation for standard IVF were
studied in 109 patients who had sperm concentrations > or =20 x
10(6)/ml. Ionophore-induced AR was performed on motile spermatozoa selected
by centrifugation on a Percoll gradient. Semen analysis was performed using
standard methods. Patients with higher (>50%, n = 76) fertilization
rates had significantly higher ionophore-induced AR than patients with
lower (<50%, n = 33) fertilization rates (49 +/- 14 versus 38 +/- 21%, P
< 0.05). When the data from all patients were analysed by logistic
regression, only the percentage sperm motility in insemination medium and
ionophore-induced AR were significantly related to fertilization rates.
Similar results were also obtained when the data from a subgroup of
patients with poor (<15% normal) sperm morphology were analysed.
However, when patients with normal sperm morphology > or =15% were
analysed separately, only sperm count and the percentage of spermatozoa
with progressive motility in semen were significantly related to
fertilization rates. In conclusion, ionophore- induced AR was significantly
related to fertilization rates in vitro mainly in patients with
teratozoospermic semen. Tests for ionophore- induced AR may provide
additional information about sperm fertilizing ability but may not indicate
specific defects of the physiological AR.
相似文献
34.
Naoki Utoguchi Tetsushi Nakata Hsien Hung Cheng Kenji Ikeda Hiroo Makimoto Yu Mu Shinsaku Nakagawa Motomasa Kobayashi Isao Kitagawa Tadanori Mayumi 《Inflammation》1997,21(2):223-233
Leukocyte adhesion to vascular endothelial cells is an essential step in the development of inflammatory diseases. We have searched for inhibitors of leukocyte-endothelial cell adhesion that could be used as anti-inflammatory drugs and found that bruceine B (0.2 g/ml; 0.44 M) inhibited human neutrophil or T cell adhesion to tumor necrosis factor- (TNF) stimulated human umbilical vein endothelial cells (HUVEC). The inhibition of neutrophil adhesion to TNF-stimulated HUVEC by bruceine B was not derived from cytotoxic effects, as determined by measurement of the level of lactate dehydrogenase (LDH) activity in conditioned medium. The effect of bruceine B on neutrophil adhesion to HUVEC was not seen when the neutrophils were preincubated with bruceine B. However, inhibitory effects were evident when the HUVEC were preincubated with bruceine B. Bruceine B also inhibited neutrophil adhesion to lipopolysaccharide-stimulated HUVEC and T cell adhesion to TNF-stimulated HUVEC. These findings suggest that bruceine B may have anti-inflammatory activity. 相似文献
35.
Yu-Li Liu Cathy Shen-Jang Fann Chih-Min Liu Jer-Yuarn Wu Shuen-Iu Hung Hung-Yu Chan Jiahn-Jyh Chen Chin-Yu Lin Shih-Kai Liu Ming H Hsieh Tzung-Jeng Hwang Wen-Chen Ouyang Chun-Ying Chen Jin-Jia Lin Frank Huang-Chih Chou Ching-Mo Chueh Wei-Ming Liu Ming-Min Tsuang Stephen V Faraone Ming T Tsuang Wei J Chen Hai-Gwo Hwu 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(4):418-420
Several studies have suggested that the regulator of G-protein signaling 4 (RGS4) may be a positional and functional candidate gene for schizophrenia. Three single nucleotide polymorphisms (SNP) located at the promoter region (SNP4 and SNP7) and the intron 1 (SNP18) of RGS4 have been verified in different ethnic groups. Positive results have been reported in these SNPs with different numbers of SNP combinatory haplotypes. In this study, these three SNP markers were genotyped in 218 schizophrenia pedigrees of Taiwan (864 individuals) for association analysis. Among these three SNPs, neither SNP4, SNP7, SNP18 has shown significant association with schizophrenia in single locus association analysis, nor any compositions of the three SNP haplotypes has shown significantly associations with the DSM-IV diagnosed schizophrenia. Our results fail to support the RGS4 as a candidate gene for schizophrenia when evaluated from these three SNP markers. 相似文献
36.
Isolation and characterization of proteins from Rous sarcoma virus 总被引:24,自引:0,他引:24
When the Bryan high-titer strain of Rous sarcoma virus RSV (RAV-1) labeled with a mixture of 14C amino acids was dissociated with a neutral detergent (Brij 35), mercaptoethanol, and urea and analyzed by isoelectric focusing in urea, seven radioactive peaks with pIs between 3.5 and 9.9 were found. The peaks were further analyzed by polyacrylamide gel electrophoresis in SDS to determine the number and molecular weight of the individual protein components in each peak. A total of eight amino acid-14C-labeled proteins were identified in RSV (RAV-1) with molecular weights between 14,000 and 96,000 daltons. When 3H-glucosamine labeled RSV (RAV-1) was dissociated with SDS and the viral components separated by SDS-gel electrophoresis, four radioactive components were observed. Analysis of glucosamine-3H-labeled virus together with amino acid-14C-labeled virus by dissociation with Brij 35, urea, and mercaptoethanol and separation of components by isoelectric focusing followed by electrophoresis in SDS-containing gels revealed that three of the glucosamine labeled components were glycoproteins corresponding to the three largest amino acid-labeled proteins. The fourth glucosamine-labeled component did did not contain radioactive amino acids suggesting that it was protein-free carbohydrate. Separation of virion components on Bio-Gel columns revealed that the glycoproteins were released from virus with Brij 35, urea, and mercaptoethanol in a large complex which was further dissociated into smaller units by SDS. Two of the eight protein components had high complement fixation titers and formed crossing precipitin lines in agar gel diffusion with hamster antiserum to the avian tumor virus group-specific antigen. 相似文献
37.
Shyh Ren Chiang Hung Jen Tang Ping Chin Chang Kuo Chen Cheng Wen Chien Ko Chung Hua Chen Yin Ching Chuang 《Journal of microbiology, immunology, and infection》2007,40(2):123-133
BACKGROUND AND PURPOSE: Vibrio vulnificus causes primary bacteremia and necrotizing wound infection, leading to high morbidity and mortality in humans. This study aimed to evaluate the antimicrobial effect of cefotaxime and minocycline on proinflammatory cytokine levels in a murine model of V. vulnificus infection. METHODS: We investigated the dynamics of proinflammatory cytokines and their modulation by antimicrobial agents using a murine model of V. vulnificus infection. The change in cytokine levels was followed over a time course to identify the antimicrobial activity of the drugs against V. vulnificus. BALB/c female mice were challenged with an intraperitoneal infection using a clinical invasive isolate of Vv05191, and their cytokine levels were assayed over various time points. RESULTS: Serum levels of tumor necrosis factor-alpha, interleukin (IL)-1 beta, and IL-6 post-infection were found to be inoculum dose-dependent and positively correlated to the subsequent fatality rate in the infected mice. With an inoculum of 6.6 x 10(6) colony-forming units and intraperitoneal administration of cefotaxime, minocycline, or both, the serum and peritoneal fluid cytokine levels increased and then declined gradually. Comparison of the 3 antimicrobial regimens revealed that the magnitude of reduction in cytokine levels was greatest in mice treated with cefotaxime-minocycline combination. Moreover, the peritoneal fluid cytokine level in the combination group was significantly lower than that in the groups treated with minocycline or cefotaxime alone. CONCLUSIONS: The current results support the superiority of the combination therapy in treating invasive V. vulnificus infections. 相似文献
38.
G T Cole J M Xue C N Okeke E J Tarcha V Basrur R A Schaller R A Herr J J Yu C Y Hung 《Medical mycology》2004,42(3):189-216
Coccidioides is a fungal pathogen of humans which can cause a life-threatening respiratory disease in immunocompetent individuals. Recurrent epidemics of coccidioidal infections in Southwestern United States has raised the specter of awareness of this soil-borne microbe, particularly among residents of Arizona and Southern California, and has galvanized research efforts to develop a human vaccine against coccidioidomycosis. In this review, we discuss the rationale for such a vaccine, examine the features of host innate and acquired immune response to Coccidioides infection, describe strategies used to identify and evaluate vaccine candidates, and provide an update on progress toward development of a vaccine against this endemic pathogen. 相似文献
39.
Yeo GS Connie Hung CC Rochford J Keogh J Gray J Sivaramakrishnan S O'Rahilly S Farooqi IS 《Nature neuroscience》2004,7(11):1187-1189
An 8-year-old male with a complex developmental syndrome and severe obesity was heterozygous for a de novo missense mutation resulting in a Y722C substitution in the neurotrophin receptor TrkB. This mutation markedly impaired receptor autophosphorylation and signaling to MAP kinase. Mutation of NTRK2, which encodes TrkB, seems to result in a unique human syndrome of hyperphagic obesity. The associated impairment in memory, learning and nociception seen in the proband reflects the crucial role of TrkB in the human nervous system. 相似文献
40.
Neonatal sepsis in the neonatal intensive care unit: characteristics of early versus late onset. 总被引:1,自引:0,他引:1
Jia-Horng Jiang Nan-Chang Chiu Fu-Yang Huang Hsin-An Kao Chyong-Hsin Hsu Han-Yang Hung Jui-Hsing Chang Chun-Chih Peng 《Journal of microbiology, immunology, and infection》2004,37(5):301-306
Neonatal sepsis is a major cause of death in newborns despite sophisticated neonatal intensive care. This retrospective study reviewed the clinical characteristics of cases of culture-proven sepsis in a neonatal intensive care unit from January 1992 to December 2001. Patients were divided into those with onset of sepsis in the first 7 days of life (early-onset group) and those with onset after the seventh day of life (late-onset group). A total of 270 cases with 325 episodes of sepsis and 353 isolated pathogens were identified and included in the study. The male-to-female ratio was 1.4. The majority of cases of sepsis occurred in low birth weight (75.9%) and premature babies (76.7%). Late onset occurred in 71.9% of cases. Patients with late onset had a lower mortality rate than those with early onset (11.3% vs 28.9%). Coagulase-negative staphylococci (20.1%) was the most common organism isolated, but infection with Pseudomonas aeruginosa was associated with the highest morality rate (55.0%). Late-onset sepsis was significantly more common in very low birth weight and premature infants. The most frequently encountered pathogens in the early-onset group were group B streptococci (GBS) and Escherichia coli, while in the late-onset group, the organisms were coagulase-negative staphylococci and Enterobacteriaceae, including E. coli, Klebsiella pneumoniae, and Acinetobacter baumannii. GBS infection resulted in the highest mortality when the onset of sepsis was within the first 24 hours of life. 相似文献