诺氟沙星缓释片的初步研究

本文初步研究了诺氟沙星缓释片的处方组成。并对不同处方进行了体外溶出试验,实验结果表明：本品的体外释药可维持12h以上且体外溶出符合一级动力学过程。     

对硝基苯乙醚的合成

目的：研究对硝基苯乙醚的合成方法。方法：以三乙胺-氯苄为相转移催化剂催化合成对硝基苯乙醚。结果：采用本方法简化工艺流程。缩短了生产周期,节约了能源,降低了生产成本。结论：有利于工业化生产,具有良好的应用前景。     

Functional significance of the signal transduction pathways Akt and Erk in ovarian follicles: in vitro and in vivo studies in cattle and sheep

Background

The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell function in vitro, and on follicle development in vivo.

Methods

Bovine granulosa and theca cells were cultured for six days and stimulated with FSH and/or IGF, or LH in combination with PD98059 (Erk inhibitor) and/or LY294002 (Akt inhibitor) and their effect on cell number and hormone secretion (estradiol, activin-A, inhibin-A, follistatin, progesterone and androstenedione) determined. In addition, ovarian follicles were treated in vivo with PD98059 and/or LY294002 in ewes on Day 3 of the cycle and follicles were recovered 48 hours later.

Results

We have shown that gonadotropin- and IGF-stimulated hormone production by granulosa and theca cells is reduced by treatment with PD98059 and LY294002 in vitro. Furthermore, treatment with PD98059 and LY294002 reduced follicle growth and oestradiol production in vivo.

Conclusion

These results demonstrate an important functional role for the Akt and Erk signalling pathways in follicle function, growth and development.     

The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

Background  

Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists.     

HPLC法测定加替沙星注射液的含量

采用HPLC法测定加替沙星注射液含量。方法精密，准确度高，重现性好。在4.4μg/ml-21.4μg/ml浓度范围内线性关系好。回收率为99.8%，RSD为0.7%。操作简便，结果准确。     

Prevalence of transfusion-transmitted Chagas disease among multitransfused patients in Brazil

Background

Prevalence and risk factors for Chlamydia trachomatis infection among young men in Switzerland is still unknown. The objective of the present study was to assess prevalence and risk factors for C. trachomatis infection in young Swiss men.

Methods

517 young Swiss men were enrolled in this cross-sectional study during their compulsory military recruitment. Participants completed a questionnaire and gave urine samples which were screened for C. trachomatis DNA by PCR. Genotyping of positive samples was done by amplification and sequencing the ompA gene.

Results

The prevalence of chlamydial infection among young Swiss male was 1.2% (95% confidence interval [95%CI], 0.4–2.5%). C. trachomatis infection was only identified among the 306 men having multiple sexual partner. Although frequent, neither unprotected sex (absence of condom use), nor alcohol and drug abuse were associated with chlamydial infection. Men living in cities were more frequently infected (2.9%, 95%CI 0.8–7.4%) than men living in rural areas (0.5%, 95%CI 0.1–1.9%, p = 0.046). Moreover, naturalised Swiss citizens were more often positive (4.9%, 95%CI 1.3–12.5%) than native-born Swiss men (0.5%, 95%CI 0.1–1.7%, p = 0.003).

Conclusion

In comparison with other countries, the prevalence of chlamydial infection in men is extremely low in Switzerland, despite a significant prevalence of risky sexual behaviour. C. trachomatis infection was especially prevalent in men with multiple sexual partners. Further research is required (i) to define which subgroup of the general population should be routinely screened, and (ii) to test whether such a targeted screening strategy will be effective to reduce the prevalence of chlamydial infection among this population.     

Low Frequency of CXCR4-Using Viruses in Patients at the Time of Primary Non-Subtype-B HIV-1 Infection

We used genotypic and phenotypic assays to estimate the frequency of X4/DM viruses in 131 patients infected with non-subtype-B viruses at the time of primary HIV-1 infection (PHI). All patients were enrolled in the French PRIMO Cohort from 1996 to 2007. Most strains belonged to CRF02_AG (51.1%) and subtype A (14.5%). Sixteen viruses (12.2%) were classified as CXCR4 tropic (“X4 strains”) by the combined criteria of amino acids 11 and 25 of the V3 loop (11/25) and net charge rules and/or the SVMgeno2pheno_10% algorithm: 6 strains by the combined genotypic rule, 7 by the SVMgeno2pheno_10% algorithm, and 3, clustering in subtype D, by both algorithms. However, only one strain (0.8%), belonging to subtype A, was defined as a dual-tropic (DM) virus by the phenotypic assay. The 67 CRF02_AG strains included 2 classified as X4 strains by the combined genotypic rule (3%) and 2 others classified as X4 strains by SVMgeno2pheno_10% (3%), but none of these 4 strains was an X4 or DM strain according to the phenotypic assay. These results suggest that the cellular virus reservoir was established with X4 strains in very few non-subtype-B-infected patients at the time of PHI. Genotypic predictions can overestimate the proportion of non-subtype-B X4 viruses at PHI.Human immunodeficiency virus type 1 (HIV-1) can be characterized by the host chemokine coreceptor that it uses to enter CD4-expressing cells. HIV-1 variants usually bind to the CCR5 chemokine coreceptor early in the course of disease. These are “R5” viruses (3, 31, 48). Viruses that use another chemokine coreceptor, CXCR4, are “X4” viruses, and they emerge later in HIV infection. They can account for up to 40 to 50% of all viruses in heavily treated patients with advanced disease (1, 32). The presence of X4 viruses has been associated with accelerated disease progression and a precipitous loss of CD4 T cells (27, 29, 40). A recent Swiss study suggested that the presence of X4 strains and the X4-specific virus load strongly predict clinical disease progression during combined antiretroviral therapy (cART), in addition to the CD4 T-cell count or viral load (44). This potential correlation between virus tropism and disease progression has important clinical implications. The development of coreceptor CCR5 antagonists for treating retroviruses and the lack of a virological response by patients infected with X4 or dual/mixed (X4/DM) viruses have increased the need to determine HIV-1 tropism.Recent studies have found the frequency of X4/DM dual-tropic strains in plasma samples from recently infected patients in the United States and Spain to be from 3.2% to 17.5% (14, 15, 16). Similarly, we found 15.9% (95% confidence interval [CI], 12.3% to 19.5%) strains of X4/DM viruses in 390 HIV-1 subtype B-infected patients diagnosed at the time of primary HIV-1 infection (PHI) in France from 1996 to 2007 (18).One of the major challenges of determining tropism is to select the best method for identifying coreceptor usage. HIV coreceptor usage is most commonly determined with a recombinant phenotype assay in clinical studies (28, 45). Bioinformatic tools based on the virus genotype may also be able to predict coreceptor usage. They are faster, less expensive, and more suitable for studies of a large number of patients than are phenotypic recombinant assays. Each available genotypic test is adequately specific but not very sensitive for detecting X4/DM or X4 variants. An overall concordance of 71.2 to 92% between genotypic and phenotypic assays has been reported (8, 15, 37, 41). However, most of these studies included HIV-1 subtype B strains. Genotypic algorithms may not be suitable for predicting the tropism of non-subtype-B HIV-1 strains (20). Two recent studies demonstrated that genotypic tests performed well for predicting the coreceptor usage of CRF02_AG and subtype C strains (36, 38), but no study has examined the correlation between genotypic and phenotypic tests for predicting the tropism of non-subtype-B HIV-1 at the time of PHI. The French PRIMO Cohort contained a large proportion of patients infected with a non-subtype-B virus (25.5% in 2005 to 2006) (6).We have therefore estimated the frequency of X4/DM viruses in 131 patients infected with non-subtype-B viruses at the time of PHI. All of them were enrolled in the French PRIMO Cohort from 1996 to 2007. We also studied the concordance between genotypic and phenotypic assays for predicting the tropism of non-subtype-B viruses in these patients.     

Virological characterization of an infection with a dual-tropic, multidrug-resistant HIV-1 and further evolution on antiretroviral therapy

We studied a case of recent infection with multidrug-resistant (MDR) HIV-1. Over 16 months off-therapy, the CD4 cell count decreased from 419 to 184 cells/mul. Antiretroviral therapy (ART) then led to an incomplete virological response but to an immunological benefit, concurrently with a shift to CCR5-only tropism and a reduction in replication capacity. ART, even if suboptimal, can be of interest in the case of MDR virus infection.