Prostasomes as potential modulators of tyrosine phosphorylation in human spermatozoa

Prostasomes, vesicles present in human semen, are known to play a role in male fertility. However, the mechanisms involved are still poorly understood. The present study looks at the direct influence of different concentrations of prostasomes on human sperm function in conditions supporting capacitation in vitro. Five million Percoll selected spermatozoa were incubated for 3?h at 37°C under an atmosphere of 5% CO? in air, in 100?μl Biggers Whitten Whittingham's medium (BWW) containing polyvinyl alcohol (PVA, 1?mg/ml) and bovine serum albumin (BSA; 3 mg/ml) in the absence or presence of increasing concentrations of prostasomes (expressed in terms of their cholesterol content: 15; 30; 45 nmoles per 100 μL of incubation medium). After in vitro exposure of spermatozoa to prostasomes, our data indicate that i) tyrosine phosphorylation intensity of the 107 KDa protein band was dose dependently lower and ii) the percentage of viable and progressive motile spermatozoa was unchanged and the percentage of non-progressive motility decreased. In addition, the incubation of prostasomes with spermatozoa resulted in an enrichment of their lipid content. Our experiments suggest that adhesion of prostasomes to spermatozoa could be responsible for the decrease in Tyrosine phosphorylation and the alteration of the mean curvilinear velocity (VCL) and the average path velocity (VAP).     

Vacuum-assisted closure as a surgical assistant in life-threatening necrotizing fasciitis in children

Necrotizing fasciitis is a severe soft tissue infection that can involve skin, subcutaneous fat, fascia and muscle. It can result in devastating sequelae including tissue necrosis, sepsis, toxic shock syndrome, cardiopulmonary collapse and death. To control rapidly spreading necrosis, early diagnosis and aggressive surgical treatment with extensive radical debridement of the affected areas is necessary, as well as systemic administration of broad-spectrum antimicrobials and, very often, intensive care support.The subatmospheric negative pressure dressing has been previously used in acute and complex wounds management. The concept of using vacuum-assisted closure dressing as another management component is presented in the current article.     

Effects of a school-based, theory-driven HIV and pregnancy prevention curriculum

CONTEXT: Although a number of interventions are effective at reducing risky adolescent sexual behavior, it may be possible to make them even more effective by addressing adolescents' approaches to risk-taking. METHODS: Schools were assigned to teach one of three curricula in a quasi-experimental intervention study: the school's standard pregnancy and HIV prevention curriculum; the Reducing the Risk curriculum; or a modified Reducing the Risk curriculum, adapted for high sensation seekers and impulsive decision makers. A sample of 1,944 students from 17 schools was surveyed at three time points between 1995 and 1997. Mixed models regression and logistic regression were used to examine the difference in impact among curricula. RESULTS: Differences in the impact of the original and modified Reducing the Risk interventions were not significant for the total sample or for high sensation seekers and impulsive decision makers separately. Students from both intervention groups demonstrated short-term improvements in knowledge; students who received their schools' standard curriculum were significantly more likely than those assigned to either intervention to have initiated sexual intercourse by the third time point (odds ratio, 2.4). CONCLUSION: More work is necessary to understand the best ways to design classroom messages that will be effective in reducing the risk behaviors of high sensation seekers and impulsive decision makers.     

Quality and functionality of human ovarian tissue after cryopreservation using an original slow freezing procedure

Purpose

To evaluate the efficiency of an original slow freezing protocol on the quality and function of human ovarian cortex.

Methods

Human ovarian tissues were cryopreserved using a freezing medium supplemented with propanediol and raffinose as cryoprotectants and antioxidants (L-glutamine, taurine). Samples were then frozen using a faster cooling rate than the usual one. Viability and morphology of follicles, DNA fragmentation in follicles and stroma as well as histology of the vascular endothelium were analyzed before and after freezing/thawing. Moreover, a functional analysis was performed based on the evaluation of follicular growth and development in thawed ovarian tissues that were cultured in vitro.

Results

Our freezing/thawing protocol allows preservation of a high proportion of viable follicles and the preservation of the different follicle developmental stages (p > 0.05 versus fresh control). 70.5 ± 5.2 % of follicles retained an intact morphology after cryopreservation (p = 0.04). Stroma cells but not follicles exhibited a slight increase of DNA fragmentation after thawing (p < 0.05). Microvessel endothelium within thawed tissues appeared to be preserved. Granulosa cells showed signs of proliferation in follicles cultured for 12 days. Secretion of 17β-oestradiol significantly increased during in vitro culture.

Conclusions

This protocol leads to good preservation of ovarian integrity and functionality post-thawing and thus appears as a suitable technique of ovarian tissue cryopreservation in clinical settings. Further research could be extended to optimize conditions of in vitro culture.     

Psychosocial correlates of adolescents' worry about STD versus HIV infection: similarities and differences

BACKGROUND: Adolescents' worry (perceived threat) of sexually transmitted diseases (STDs) and HIV infection may have different correlates. This study examined associations between selected psychosocial and behavioral constructs and adolescents' worry about STD and HIV infection. GOAL: To assess levels and correlates of worry about STD and HIV among a high-risk sample of black adolescent females. STUDY DESIGN: High-risk black females (n = 522), enrolled in a randomized, controlled HIV and STD prevention trial, completed a questionnaire and structured interview at baseline. Worry about STD and HIV infection, recent risk behaviors, and several measures potentially related to worry were assessed. RESULTS: Levels of worry for both STD and HIV were low. Recent history of STD infection was associated with STD worry (OR, 4.6) and HIV worry (OR, 2.0). Infrequent communication about sex (OR, 2.0) and low perceived ability to negotiate condom use (OR, 2.0) were related to STD worry; whereas, only partner-specific barriers were related to HIV worry (OR, 1.9). CONCLUSIONS: Despite high risk, adolescents were generally complacent about the threat of infection with STD and HIV. Adolescents' worry about STD and HIV infection had different sets of correlates.     

Home, school, and neighborhood environment factors and youth physical activity

This study examined the contributions of home, school, and neighborhood factors related to youth physical activity (PA). Adolescents (ages 12-18; N = 137) and parents of younger children (ages 5-11; N = 104) from three US metropolitan areas completed surveys. Youth PA was estimated from six items assessing overall physical activity. Bivariate analyses between environment factors and PA were significant correlations in each environmental setting for adolescents (r's:0.16-0.28), but for parents of children, only for the home and neighborhood settings (r's: 0.14-0.39). For adolescents, pieces of equipment at home, family recreation membership, equipment at school, and neighborhood aesthetics explained 15.8% of variance in PA. For younger children (based on parent report), pieces of equipment at home, neighborhood traffic safety, walking/cycling facilities, and street connectivity explained 21.4% of the variance in PA. Modifiable factors like increasing access to equipment at home and school, and improving neighborhood aesthetics may impact youth PA. To optimize explanation of youth PA, factors from multiple environments need to be considered.     

Inhibitory activity of xanthine oxidase by fractions Crateva adansonii

ObjectiveTo study the inhibitory effect of various extracts from Crateva adansonii (C. adansonii) used traditionally against several inflammatory diseases such as rheumatism, arthritis, and gout, was investigated on purified bovine milk xanthine oxidase (XO) activity.MethodsXanthine oxidase inhibitory activity was assayed spectrophotometrically and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295 nm associated with uric acid formation. Enzyme kinetics was carried out using Lineweaver-Burk plots using xanthine as the substrate.ResultsAmong the fractions tested, the chloroform fraction exhibited highest potency (IC₅₀ 20.2±1.6 μg/mL) followed by the petroleum ether (IC₅₀ 30.1±2.2 μg/mL), ethyl acetate (IC₅₀ 43.9±1.4 μg/mL) and residual (IC₅₀ 98.0±3.3 μg/mL) fractions. The IC₅₀ value of allopurinol used, as the standard was 5.7±0.3 μg/mL.ConclusionsEnzyme inhibition mechanism indicated that the mode of inhibition was of a mixed type. Our findings suggest that the therapeutic use of these plants may be due to the observed Xanthine oxidase inhibition, thereby supporting their use in traditional folk medicine against inflammatory-related diseases, in particular, gout.     

Electrical Performance and Automatic Capture Characteristics of a 3.5-mm2 Passive Fixation Lead during 1-Year Follow-Up

Background: Bipolar low polarization electrodes are recommended for a regular AutoCapture™ (St. Jude Medical, Inc., Sylmar, CA, USA) function in order to effectively detect the evoked response (ER) signal. The objective of this national multicenter registry was to evaluate the electrical performance and the AutoCapture™ characteristics of the bipolar ventricular pacing lead IsoFlex S, model 1636T or 1646T (St. Jude Medical), in combination with single- and dual-chamber pacemakers.
Methods: Ventricular pacing and sensing thresholds, lead impedance, ER amplitude, and polarization signals were measured at discharge and routine follow-up visits after 1, 3, 6, 9, and 12 months. AutoCapture™ activation was recommended based on the results of the ER sensitivity test.
Results: Of the 252 patients initially included, 109 (43%) have completed the follow-up. The mean ventricular pacing threshold was 0.43 ± 0.19 V at discharge and 0.68 ± 0.32 V at 12 months postimplant. The values for the ventricular sensing threshold were between 9.51 ± 4.12 and 9.99 ± 4.09 mV at discharge and at the 12-month follow-up. The unipolar lead impedance decreased from 533 ± 94 to 476 ± 73 ohms during the follow-up. The mean ER amplitude was 16.47 ± 6.70 mV at discharge and 17.42 ± 7.43 mV after 12 months, and the corresponding mean polarization signals were 0.59 ± 1.00 and 0.74 ± 1.24 mV, respectively. AutoCapture™ activation was recommended in at least 95% of the patients investigated over the 12-month follow-up.
Conclusion: The bipolar ventricular pacing lead IsoFlex S 1636/1646T shows a good electrical performance and is mostly compatible with the AutoCapture™ algorithm.     

细粒棘球蚴重组抗原B的表达提取及其血清学检测初探

用基因工程技术制备出的细粒棘球绦虫重组抗原B（rAgB）表达载体,经诱导表达、亲和层析纯化获得具生物活性的重组蛋白质rAgB,用Western-Blot法检测病人血清。结果显示rAgB敏感性为91．6％（44／48）,特异性为93．8％（30／32）,其中10例泡球蚴（AE）病人及10例肿瘤病人血清均无交叉反应。说明rAgB具有较高的敏感性及特异性,可用于包虫病的常规血清学诊断,rAgB在宿主菌JM109内稳定表达,因此可在实验室内大量制备用于血清学诊断的rAgB。