Time interleaved optical sampling for ultra-high speed A/D conversion

A scheme is proposed for increasing the sampling rate of analogue-to-digital conversion by more than an order of magnitude by combining state-of-the-art A/D converters with photonic technology. Ultra-high speed sampling is performed optically by a multiwavelength pulse train. Wavelength demultiplexers convert the high repetition rate data stream of samples into parallel data streams that can be handled by available electronic A/D converters

Hybrid mode-lock InGaAsP/InP MQW laser as a multiwavelength source for WDM

A hybrid mode-locked semiconductor laser was demonstrated as a multi-wavelength light source for WDM networks. The laser simultaneously provides over 50 WDM channels spaced at 21.8 GHz (0.17 nm). Channel spacing is temperature independent and is determined by the modulating frequency applied to the absorber section of the laser, thus is very stable. The wavelength of the channels can be slightly tuned by injection current and/or temperature. We demonstrate dropping a WDM channel at a network node by using a Fiber Bragg Grating combined with a fiber coupler

Hybrid mode-lock InGaAsP/InP MQW laser as a multiwavelength source for WDM

A hybrid mode-locked semiconductor laser was demonstrated as a multi-wavelength light source for WDM networks. The laser simultaneously provides over 50 WDM channels spaced at 21.8 GHz (0.17 nm). Channel spacing is temperature independent and is determined by the modulating frequency applied to the absorber section of the laser, thus is very stable. The wavelength of the channels can be slightly tuned by injection current and/or temperature. We demonstrate dropping a WDM channel at a network node by using a Fiber Bragg Grating combined with a fiber coupler

Comparison of oral and vaginal metronidazole for treatment of bacterial vaginosis in pregnancy: impact on fastidious bacteria

<p>Abstract</p> <p>Background</p> <p>Bacterial vaginosis (BV) is a common condition that is associated with preterm birth and acquisition of complex communities of vaginal bacteria that include several fastidious species. Treatment of BV in pregnancy has mixed effects on the risk of preterm delivery, which some hypothesize is due to variable antibiotic efficacy for the fastidious bacteria. Both oral and intravaginal metronidazole can be used to treat bacterial vaginosis in pregnancy, but little is known about the impact of different routes of antibiotic administration on concentrations of fastidious vaginal bacteria.</p> <p>Methods</p> <p>This was a sub-study of a larger randomized trial of oral versus vaginal metronidazole for treatment of BV in pregnancy. Fifty-three women were evaluated, including 30 women who received oral metronidazole and 23 who received intravaginal metronidazole. Bacterial taxon-specific quantitative PCR assays were used to measure concentrations of bacterial vaginosis associated bacterium (BVAB) 1, 2, and 3, <it>Gardnerella vaginalis, Atopobium </it>species, <it>Leptotrichia/Sneathia </it>species, <it>Megasphaera </it>species, and <it>Lactobacillus crispatus </it>before and after antibiotic treatment.</p> <p>Results</p> <p>Concentrations of <it>Leptotrichia </it>and <it>Sneathia </it>spp. and the fastidious Clostridia-like bacterium designated BVAB1 decreased significantly with oral (p = .002, p = .02) but not vaginal therapy (p = .141, p = .126). The fastidious bacterium BVAB3 did not significantly decrease with either treatment. Concentrations of <it>Atopobium </it>spp., reportedly resistant to metronidazole <it>in vitro</it>, dropped significantly with oral (p = .002) and vaginal (p = .001) treatment. There was no significant difference in the magnitude of change in bacterial concentrations between oral and vaginal treatment arms for any of the bacterial species. <it>Lactobacillus crispatus </it>concentrations did not change.</p> <p>Conclusion</p> <p>Both oral and vaginal metronidazole therapy in pregnant women result in a significant decrease in concentrations of most BV-associated anaerobic bacteria, with the exception that <it>Leptotrichia, Sneathia </it>and BVAB1 do not significantly decrease with vaginal metronidazole therapy. These data suggest that the route of antibiotic administration has a minor impact on bacterial eradication in pregnant women with BV.</p> <p>Trail Registration</p> <p>This trial is registered with ClinicalTrials.gov, number NCT00153517</p

Antiseptics and disinfectants for the treatment of bacterial vaginosis: a systematic review

Background: The study objective was to assess the available data on efficacy and tolerability of antiseptics and disinfectants in treating bacterial vaginosis (BV). Methods: A systematic search was conducted by consulting PubMed (1966-2010), CINAHL (1982-2010), IPA (1970-2010), and the Cochrane CENTRAL databases. Clinical trials were searched for by the generic names of all antiseptics and disinfectants listed in the Anatomical Therapeutic Chemical (ATC) Classification System under the code D08A. Clinical trials were considered eligible if the efficacy of antiseptics and disinfectants in the treatment of BV was assessed in comparison to placebo or standard antibiotic treatment with metronidazole or clindamycin and if diagnosis of BV relied on standard criteria such as Amsel\u27s and Nugent\u27s criteria. Results: A total of 262 articles were found, of which 15 reports on clinical trials were assessed. Of these, four randomised controlled trials (RCTs) were withheld from analysis. Reasons for exclusion were primarily the lack of standard criteria to diagnose BV or to assess cure, and control treatment not involving placebo or standard antibiotic treatment. Risk of bias for the included studies was assessed with the Cochrane Collaboration\u27s tool for assessing risk of bias. Three studies showed non-inferiority of chlorhexidine and polyhexamethylene biguanide compared to metronidazole or clindamycin. One RCT found that a single vaginal douche with hydrogen peroxide was slightly, though significantly less effective than a single oral dose of metronidazole. Conclusion: The use of antiseptics and disinfectants for the treatment of BV has been poorly studied and most studies are somehow methodologically flawed. There is insufficient evidence at present to advocate the use of these agents, although some studies suggest that some antiseptics may have equal efficacy compared to clindamycin or metronidazole. Further study is warranted with special regard to the long-term efficacy and safety of antiseptics and disinfectants for vaginal use

Antibody-Based Detection and Inhibition of Vaginolysin, the Gardnerella vaginalis Cytolysin

Bacterial vaginosis (BV) is the most common vaginal infection worldwide and is associated with significant adverse sequelae. We have recently characterized vaginolysin (VLY), the human-specific cytotoxin produced by Gardnerella vaginalis and believed to play a critical role in the pathogenesis of BV and its associated morbidities. We hypothesize that novel antibody-based strategies may be useful for detection of VLY and for inhibition of its toxic effects on human cells. Using purified toxin as an immunogen, we generated polyclonal rabbit immune serum (IS) against VLY. A western blot of G. vaginalis lysate was probed with IS and a single band (57 kD) identified. Immunofluorescence techniques using IS detected VLY production by G. vaginalis. In addition, we have developed a sandwich ELISA assay capable of VLY quantification at ng/ml concentrations in the supernatant of growing G. vaginalis. To investigate the potential inhibitory role of IS on VLY-mediated cell lysis, we exposed human erythrocytes to VLY or VLY pretreated with IS and determined the percent hemolysis. Pretreatment with IS resulted in a significant reduction in VLY-mediated lysis. Similarly, both human cervical carcinoma cells and vaginal epithelial cells exhibited reduced cytolysis following exposure to VLY with IS compared to VLY alone. These results confirm that antibody-based techniques are an effective means of VLY detection. Furthermore, VLY antiserum functions as an inhibitor of VLY–CD59 interaction, mitigating cell lysis. These strategies may have a potential role in the diagnosis and treatment of BV

Bacterial vaginosis

Bacterial vaginosis is the most prevalent cause of abnormal vaginal discharge in women of childbearing age. It can have a major impact on quality of life and psychological wellbeing if frequently recurrent and strongly symptomatic. The use of molecular techniques to study the vaginal microbiome is increasing our understanding of the dynamic changes in flora that occur in health and disease. It might soon be possible to separate Gardnerella into different pathogenic and non-pathogenic species. Many groups are studying compounds that can disrupt the biofilm which is dominated by Gardnerella and Atopobium vaginae. Several studies in the last decade support the concept of bacterial vaginosis as a sexually transmitted infection

Risks for Acquisition of Bacterial Vaginosis Among Women Who Report Sex with Women: A Cohort Study

Bacterial vaginosis (BV) is common in women who have sex with women. While cross-sectional data support a role for sexual transmission, risks for incident BV have not been prospectively studied in this group. at enrollment conferred reduced risk for subsequent BV (HR 0.18 (0.08–0.4)). Detailed analysis of behavioral data suggested a direct dose-response relationship with increasing number of episodes of receptive oral-vulvovaginal sex (HR 1.02 (95% CI, 1.00–1.04).Vaginal detection of several BVAB in BV-negative women predicted subsequent BV, suggesting that changes in vaginal microbiota precede BV by weeks or months. BV acquisition was associated with report of new partner with BV; associations with sexual practices – specifically, receptive oral sex – require further investigation