169,901 research outputs found
The Impact of GB Virus C co-infection on Mother to Child transmission of Human Immunodeficiency Virus
No full textBhanich Supapol W, Remis RS, Raboud J, Millson M, Tappero J, Kaul R, Kulkarni P, McConnell MS, Mock PA, Culnane M, McNicholl J, Roongpisuthipong A, Chotpitayasunondh T, Shaffer N, Butera S. 2008. Reduced mother-to-child transmission of HIV associated with infant but not maternal GB virus C infection. J Infect Dis 197(10):1369-1377.
Bhanich Supapol W, Remis RS, Raboud J, Millson M, Tappero JW, Kaul R, Kulkarni P, McConnell MS, Mock PA, McNicholl JM, Vanprarar N, Asavapiriayanont S, Shaffer N, Butera ST. 2009. Mother-to-child transmission of GB virus C in a cohort of women coinfected with GB virus C and HIV in Bangkok, Thailand. J Infect Dis 200:227-235.GB virus C (GBV-C) is a common, apathogenic virus that can inhibit human immunodeficiency virus (HIV) replication in vitro. Persistent coinfection with GBV-C
has been associated with improved survival among HIV-infected adults while loss of
GBV-C viremia has been associated with poor survival. If GBV-C does inhibit HIV
replication, it is possible that GBV-C infection may reduce mother-to-child-transmission (MTCT) of HIV. This study investigated whether maternal or infant GBV-C infection was associated with reduced MTCT of HIV infection. The study population consisted of 1,783 pregnant women from three Bangkok perinatal HIV transmission studies (1992-94, 1996-7, 1999-2004). We tested plasma collected at delivery for GBV-C RNA, GBV-C antibody, and GBV-C viral genotype. If maternal GBV-C RNA was detected, the four- or six-month infant specimen was tested for GBV-C RNA. Rates of MTCT of HIV in GBV-C-infected and GBV-C-uninfected women and infants were compared using multiple logistic regression as were associations with MTCT of GBV-C and prevalence of GBV-C infection.
The prevalence of GBV-C infection (i.e. presence of RNA or antibody) was 33%
among HIV-infected women and 15% among HIV-uninfected women. Forty-one percent
of GBV-C-RNA-positive women transmitted GBV-C to their infants. Only two of 101
(2.0%) GBV-C-RNA-positive infants acquired HIV infection compared to 162 (13.2%)
of 1,232 of GBV-C-RNA-negative infants (RR 0.15, p<0.0001). This association
remained after adjustment for maternal HIV viral load, antiretroviral prophylaxis, CD4+
count and other covariates. MTCT of HIV was not associated with presence of maternal
GBV-C RNA or maternal GBV-C antibody. Maternal receipt of antiretroviral therapy
was associated with increased MTCT of GBV-C, as was high GBV-C viral load, vaginal
delivery and absence of infant HIV infection. GBV-C infection among women was
independently associated with more than one lifetime sexual partner, intravenous drug
use and HIV-infection.
We observed a higher prevalence of GBV-C infection among HIV-infected compared to HIV-uninfected pregnant women in Thailand, likely due to common risk factors. Antiretroviral therapy appears to increase MTCT of GBV-C. Infant GBV-C acquisition, but not maternal GBV-C infection, was significantly associated with reduced MTCT of HIV. Mechanisms for these later two associations are unknown.Ph
The Impact of GB Virus C co-infection on Mother to Child transmission of Human Immunodeficiency Virus
No full textBhanich Supapol W, Remis RS, Raboud J, Millson M, Tappero J, Kaul R, Kulkarni P, McConnell MS, Mock PA, Culnane M, McNicholl J, Roongpisuthipong A, Chotpitayasunondh T, Shaffer N, Butera S. 2008. Reduced mother-to-child transmission of HIV associated with infant but not maternal GB virus C infection. J Infect Dis 197(10):1369-1377.
Bhanich Supapol W, Remis RS, Raboud J, Millson M, Tappero JW, Kaul R, Kulkarni P, McConnell MS, Mock PA, McNicholl JM, Vanprarar N, Asavapiriayanont S, Shaffer N, Butera ST. 2009. Mother-to-child transmission of GB virus C in a cohort of women coinfected with GB virus C and HIV in Bangkok, Thailand. J Infect Dis 200:227-235.GB virus C (GBV-C) is a common, apathogenic virus that can inhibit human immunodeficiency virus (HIV) replication in vitro. Persistent coinfection with GBV-C
has been associated with improved survival among HIV-infected adults while loss of
GBV-C viremia has been associated with poor survival. If GBV-C does inhibit HIV
replication, it is possible that GBV-C infection may reduce mother-to-child-transmission (MTCT) of HIV. This study investigated whether maternal or infant GBV-C infection was associated with reduced MTCT of HIV infection. The study population consisted of 1,783 pregnant women from three Bangkok perinatal HIV transmission studies (1992-94, 1996-7, 1999-2004). We tested plasma collected at delivery for GBV-C RNA, GBV-C antibody, and GBV-C viral genotype. If maternal GBV-C RNA was detected, the four- or six-month infant specimen was tested for GBV-C RNA. Rates of MTCT of HIV in GBV-C-infected and GBV-C-uninfected women and infants were compared using multiple logistic regression as were associations with MTCT of GBV-C and prevalence of GBV-C infection.
The prevalence of GBV-C infection (i.e. presence of RNA or antibody) was 33%
among HIV-infected women and 15% among HIV-uninfected women. Forty-one percent
of GBV-C-RNA-positive women transmitted GBV-C to their infants. Only two of 101
(2.0%) GBV-C-RNA-positive infants acquired HIV infection compared to 162 (13.2%)
of 1,232 of GBV-C-RNA-negative infants (RR 0.15, p<0.0001). This association
remained after adjustment for maternal HIV viral load, antiretroviral prophylaxis, CD4+
count and other covariates. MTCT of HIV was not associated with presence of maternal
GBV-C RNA or maternal GBV-C antibody. Maternal receipt of antiretroviral therapy
was associated with increased MTCT of GBV-C, as was high GBV-C viral load, vaginal
delivery and absence of infant HIV infection. GBV-C infection among women was
independently associated with more than one lifetime sexual partner, intravenous drug
use and HIV-infection.
We observed a higher prevalence of GBV-C infection among HIV-infected compared to HIV-uninfected pregnant women in Thailand, likely due to common risk factors. Antiretroviral therapy appears to increase MTCT of GBV-C. Infant GBV-C acquisition, but not maternal GBV-C infection, was significantly associated with reduced MTCT of HIV. Mechanisms for these later two associations are unknown.Ph
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Treatment of histologically mild hepatitis C virus infection with interferon and ribavirin: a multicentre randomized controlled trial
No full textCurrent guidelines advocate no treatment for patients with histologically mild hepatitis C virus (HCV) infection. This was a UK multicentre randomized controlled trial comparing alpha-interferon (3 MU thrice weekly) + ribavirin (1000-1200 mg/day) for 48 weeks with no treatment in treatment naive, adult patients with histologically mild chronic HCV infection. The aim was to compare benefits, safety and efficacy of combination therapy with alpha-interferon 2b and ribavirin for 48 weeks with no treatment (current standard management) in this patient group. In the treatment group 32 of 98 (33%) patients achieved a sustained virological response (SVR). Patients infected with genotype 1 had a lower SVR than those infected with genotype non-1 (18% vs 49% P = 0.02). No patients who failed to achieve a 2-log drop in viral load at 12 weeks achieved SVR. Improvements in quality of life 24 weeks postcessation of therapy compared with baseline using the SF-36 questionnaire measures were observed in the treated group. For patients with mild HCV infection with viral genotype non-1, the results are sufficiently good to suggest that therapeutic decisions should no longer be biopsy-driven. For patients infected with genotype 1, a liver biopsy is still indicated as the low chance of SVR is outweighed by an unacceptable burden of side-effects. Patients who fail to respond by 12 weeks of therapy should have their treatment curtailed early.</p
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Ceramics of the Tyne-Forth Region, C. 3500-1500 BC.
No full textSince the beginnings of archaeology, the study of the past in the Tyne-Forth region has been shadowed by the influence of the political boundary that divides it. Although it has long been acknowledged by archaeologists that the modern polities of Scotland and England did not exist in the past, this divide has continued to affect research design, interpretation and publication. In addition to this, the focus on 'core areas', such as Wessex and Orkney, have long been used to interpret the findings in this region, although the remains found between the Tyne and Forth continue to demonstrate that this area was unique and did not necessarily adhere to the same lifeways as these distant lands. For too long this has caused the area to be seen as a periphery. This research has attempted to consider the Neolithic and Bronze Age of this area as a whole, by ignoring the Anglo-Scottish border and by considering the archaeological remains of the entire region using a single methodology and the data was evaluated to establish the norms for the region first, before relating it to what is known nationally. Experimental work was first carried out to learn more about the material and the ways ceramics can be studied in order to design the research so that it would yield the greatest amount of data. A provenance study of the archaeological remains was then carried out. A total of 333 vessels from the Middle Neolithic to the Middle Bronze Age, including: Impressed Ware, Grooved Ware, Beaker, Food Vessel, Vase Urns, Collared Urns, Cordoned Urns and Bucket Urns were examined. The resulting data were statistically analysed and evidence for cultural interaction, particularly during the introduction of Beakers, was found. The presence local influence on some pottery (previously identified as Neolithic-derived pottery by Millson et al. 2012 in the Milfield Basin, Northumberland) was also recorded throughout the region. Both of these important findings were considered in-depth and a better understanding of the Late Neolithic/Bronze Age transition is proposed for this region
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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