1,150 research outputs found
The HIV Genomic Incidence Assay Meets False Recency Rate and Mean Duration of Recency Infection Performance Standards.
HIV incidence is a primary metric for epidemic surveillance and prevention efficacy assessment. HIV incidence assay performance is evaluated via false recency rate (FRR) and mean duration of recent infection (MDRI). We conducted a meta-analysis of 438 incident and 305 chronic specimens' HIV envelope genes from a diverse global cohort. The genome similarity index (GSI) accurately characterized infection stage across diverse host and viral factors. All except one chronic specimen had GSIs below 0.67, yielding a FRR of 0.33 [0-0.98] %. We modeled the incidence assay biomarker dynamics with a logistic link function assuming individual variabilities in a Beta distribution. The GSI probability density function peaked close to 1 in early infection and 0 around two years post infection, yielding MDRI of 420 [361, 467] days. We tested the assay by newly sequencing 744 envelope genes from 59 specimens of 21 subjects who followed from HIV negative status. Both standardized residuals and Anderson-Darling tests showed that the test dataset was statistically consistent with the model biomarker dynamics. This is the first reported incidence assay meeting the optimal FRR and MDRI performance standards. Signatures of HIV gene diversification can allow precise cross-sectional surveillance with a desirable temporal range of incidence detection
Daily HIV pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate-emtricitabine reduced Streptococcus and increased Erysipelotrichaceae in rectal microbiota.
Daily PrEP is highly effective at preventing HIV-1 acquisition, but risks of long-term tenofovir disoproxil fumarate plus emtricitabine (TDF-FTC) include renal decline and bone mineral density decrease in addition to initial gastrointestinal side effects. We investigated the impact of TDF-FTC on the enteric microbiome using rectal swabs collected from healthy MSM before PrEP initiation and after 48 to 72 weeks of adherent PrEP use. The V4 region of the 16S ribosomal RNA gene sequencing showed that Streptococcus was significantly reduced from 12.0% to 1.2% (p = 0.036) and Erysipelotrichaceae family was significantly increased from 0.79% to 3.3% (p = 0.028) after 48-72 weeks of daily PrEP. Catenibacterium mitsuokai, Holdemanella biformis and Turicibacter sanguinis were increased within the Erysipelotrichaceae family and Streptococcus agalactiae, Streptococcus oralis, Streptococcus mitis were reduced. These changes were not associated with host factors including PrEP duration, age, race, tenofovir diphosphate blood level, any drug use and drug abuse, suggesting that the observed microbiome shifts were likely induced by daily PrEP use. Long-term PrEP resulted in increases of Catenibacterium mitsuokai and Holdemanella biformis, which have been associated with gut microbiome dysbiosis. Our observations can aid in characterizing PrEP's side effects, which is likely to improve PrEP adherence, and thus HIV-1 prevention
Use of a porous membrane for gas bubble removal in microfluidic channels: physical mechanisms and design criteria
We demonstrate and explain a simple and efficient way to remove gas bubbles
from liquid-filled microchannels, by integrating a hydrophobic porous membrane
on top of the microchannel. A prototype chip is manufactured in hard,
transparent polymer with the ability to completely filter gas plugs out of a
segmented flow at rates up to 7.4 microliter/s per mm2 of membrane area. The
device involves a bubble generation section and a gas removal section. In the
bubble generation section, a T-junction is used to generate a train of gas
plugs into a water stream. These gas plugs are then transported towards the gas
removal section, where they slide along a hydrophobic membrane until complete
removal. The system has been successfully modeled and four necessary operating
criteria have been determined to achieve a complete separation of the gas from
the liquid. The first criterion is that the bubble length needs to be larger
than the channel diameter. The second criterion is that the gas plug should
stay on the membrane for a time sufficient to transport all the gas through the
membrane. The third criterion is that the gas plug travel speed should be lower
than a critical value: otherwise a stable liquid film between the bubble and
the membrane prevents mass transfer. The fourth criterion is that the pressure
difference across the membrane should not be larger than the Laplace pressure
to prevent water from leaking through the membrane
Electric Field-Tuned Topological Phase Transition in Ultra-Thin Na3Bi - Towards a Topological Transistor
The electric field induced quantum phase transition from topological to
conventional insulator has been proposed as the basis of a topological field
effect transistor [1-4]. In this scheme an electric field can switch 'on' the
ballistic flow of charge and spin along dissipationless edges of the
two-dimensional (2D) quantum spin Hall insulator [5-9], and when 'off' is a
conventional insulator with no conductive channels. Such as topological
transistor is promising for low-energy logic circuits [4], which would
necessitate electric field-switched materials with conventional and topological
bandgaps much greater than room temperature, significantly greater than
proposed to date [6-8]. Topological Dirac semimetals(TDS) are promising systems
in which to look for topological field-effect switching, as they lie at the
boundary between conventional and topological phases [3,10-16]. Here we use
scanning probe microscopy/spectroscopy (STM/STS) and angle-resolved
photoelectron spectroscopy (ARPES) to show that mono- and bilayer films of TDS
Na3Bi [3,17] are 2D topological insulators with bulk bandgaps >400 meV in the
absence of electric field. Upon application of electric field by doping with
potassium or by close approach of the STM tip, the bandgap can be completely
closed then re-opened with conventional gap greater than 100 meV. The large
bandgaps in both the conventional and quantum spin Hall phases, much greater
than the thermal energy kT = 25 meV at room temperature, suggest that ultrathin
Na3Bi is suitable for room temperature topological transistor operation
Variation of health-related quality of life assessed by caregivers and patients affected by severe childhood infections.
BACKGROUND: The agreement between self-reported and proxy measures of health status in ill children is not well established. This study aimed to quantify the variation in health-related quality of life (HRQOL) derived from young patients and their carers using different instruments. METHODS: A hospital-based cross-sectional survey was conducted between August 2010 and March 2011. Children with meningitis, bacteremia, pneumonia, acute otitis media, hearing loss, chronic lung disease, epilepsy, mild mental retardation, severe mental retardation, and mental retardation combined with epilepsy, aged between five to 14 years in seven tertiary hospitals were selected for participation in this study. The Health Utilities Index Mark 2 (HUI2), and Mark 3 (HUI3), and the EuroQoL Descriptive System (EQ-5D) and Visual Analogue Scale (EQ-VAS) were applied to both paediatric patients (self-assessment) and caregivers (proxy-assessment). RESULTS: The EQ-5D scores were lowest for acute conditions such as meningitis, bacteremia, and pneumonia, whereas the HUI3 scores were lowest for most chronic conditions such as hearing loss and severe mental retardation. Comparing patient and proxy scores (n = 74), the EQ-5D exhibited high correlation (r = 0.77) while in the HUI2 and HUI3 patient and caregiver scores were moderately correlated (r = 0.58 and 0.67 respectively). The mean difference between self and proxy-assessment using the HUI2, HUI3, EQ-5D and EQ-VAS scores were 0.03, 0.05, -0.03 and -0.02, respectively. In hearing-impaired and chronic lung patients the self-rated HRQOL differed significantly from their caregivers. CONCLUSIONS: The use of caregivers as proxies for measuring HRQOL in young patients affected by pneumococcal infection and its sequelae should be employed with caution. Given the high correlation between instruments, each of the HRQOL instruments appears acceptable apart from the EQ-VAS which exhibited low correlation with the others
How much do you know about benign, preneoplastic, non-invasive and invasive neoplastic lesions of the urinary bladder classified according to the 2004 WHO scheme?
The aim of this essay is the self assessment of the level of knowledge of the 2004 WHO classification of bladder neoplasms through a series of MCQs, each associated a short commentary. This paper is directed to all who are involved with the application of this classification at the anticancer research, diagnostic, prognostic and therapeutic levels, in particular to uropathologists, urologists and oncologists
Rewriting System for Profile-Guided Data Layout Transformations on Binaries
International audienceCareful data layout design is crucial for achieving high performance. However exploring data layouts is time-consuming and error-prone, and assessing the impact of a layout transformation on performance is difficult without performing it. We propose to guide application programmers through data layout restructuring by providing a comprehensive multidimensional description of the initial layout, built from trace analysis, and then by giving a performance evaluation of the transformations tested and an expression of each transformed layout. The programmer can limit the exploration to layouts matching some patterns. We apply this method to two multithreaded applications. The performance prediction of multiple transformations matches within 5% the performance of hand-transformed layout code
A new multicompartmental reaction-diffusion modeling method links transient membrane attachment of E. coli MinE to E-ring formation
Many important cellular processes are regulated by reaction-diffusion (RD) of molecules that takes place both in the cytoplasm and on the membrane. To model and analyze such multicompartmental processes, we developed a lattice-based Monte Carlo method, Spatiocyte that supports RD in volume and surface compartments at single molecule resolution. Stochasticity in RD and the excluded volume effect brought by intracellular molecular crowding, both of which can significantly affect RD and thus, cellular processes, are also supported. We verified the method by comparing simulation results of diffusion, irreversible and reversible reactions with the predicted analytical and best available numerical solutions. Moreover, to directly compare the localization patterns of molecules in fluorescence microscopy images with simulation, we devised a visualization method that mimics the microphotography process by showing the trajectory of simulated molecules averaged according to the camera exposure time. In the rod-shaped bacterium _Escherichia coli_, the division site is suppressed at the cell poles by periodic pole-to-pole oscillations of the Min proteins (MinC, MinD and MinE) arising from carefully orchestrated RD in both cytoplasm and membrane compartments. Using Spatiocyte we could model and reproduce the _in vivo_ MinDE localization dynamics by accounting for the established properties of MinE. Our results suggest that the MinE ring, which is essential in preventing polar septation, is largely composed of MinE that is transiently attached to the membrane independently after recruited by MinD. Overall, Spatiocyte allows simulation and visualization of complex spatial and reaction-diffusion mediated cellular processes in volumes and surfaces. As we showed, it can potentially provide mechanistic insights otherwise difficult to obtain experimentally
Phase II Trial of Concurrent Sunitinib and Image-Guided Radiotherapy for Oligometastases
BACKGROUND: Preclinical data suggest that sunitinib enhances the efficacy of radiotherapy. We tested the combination of sunitinib and hypofractionated image-guided radiotherapy (IGRT) in a cohort of patients with historically incurable distant metastases. METHODS: Twenty five patients with oligometastases, defined as 1-5 sites of active disease on whole body imaging, were enrolled in a phase II trial from 2/08 to 9/10. The most common tumor types treated were head and neck, liver, lung, kidney and prostate cancers. Patients were treated with the recommended phase II dose of 37.5 mg daily sunitinib (days 1-28) and IGRT 50 Gy (days 8-12 and 15-19). Maintenance sunitinib was used in 33% of patients. Median follow up was 17.5 months (range, 0.7 to 37.4 months). RESULTS: The 18-month local control, distant control, progression-free survival (PFS) and overall survival (OS) were 75%, 52%, 56% and 71%, respectively. At last follow-up, 11 (44%) patients were alive without evidence of disease, 7 (28%) were alive with distant metastases, 3 (12%) were dead from distant metastases, 3 (12%) were dead from comorbid illness, and 1 (4%) was dead from treatment-related toxicities. The incidence of acute grade ≥ 3 toxicities was 28%, most commonly myelosuppression, bleeding and abnormal liver function tests. CONCLUSIONS: Concurrent sunitinib and IGRT achieves major clinical responses in a subset of patients with oligometastases. TRIAL REGISTRATION: ClinicalTrials.gov NCT00463060
Ectopic opening of the common bile duct and duodenal stenosis: an overlooked association
<p>Abstract</p> <p>Background</p> <p>Ectopic opening of the common bile duct into the duodenal bulb (EO-CBD-DB) is a rare disease that may be complicated by duodenal ulcer, deformity, stenosis and biliary stones. The aim of this study is to report clinical presentations, endoscopic diagnosis and treatment of this entity as well as to investigate its association with duodenal stenosis.</p> <p>Methods</p> <p>Gastroduodenoscopic findings and radiological imaging were evaluated for ectopic papilla and duodenal stenosis. Diagnostic methods, endoscopic procedures and long-term outcomes of the endoscopic treatment were presented.</p> <p>Results</p> <p>EO-CBD-DB was found in 74 (77.1%) of the 96 patients with duodenal deformity/stenosis (79 male, 17 female, mean age: 58.5, range: 30-87 years). The papilla with normal appearance was retracted to the bulb in 11 while it was at its usual location in the remaining 11. The history of biliodigestive surgery was more common in patients with EO-CBD-DB who were frequently presented with the common bile duct stone-related symptoms than the other patients. Thirteen (17.6%) of the patients with EO-CBD-DB were referred to surgery. Endoscopic treatment was completed in 60 (81.1%) patients after an average of 1.7 (range: 1-6) procedures. These patients were on follow-up for 24.8 (range: 2-46) months. Endoscopic intervention was required in 12 (20%) of them because of recurrent biliary problems. Treatment of the patient who had stricture due to biliary injury during laparoscopic cholecystectomy is still continued.</p> <p>Conclusions</p> <p>The presence of EO-CBD-DB should be considered particularly in middle-aged male patients who have duodenal deformity/stenosis. Endoscopic treatment is feasible in these patients. The long-term outcomes of endoscopic therapy need to be compared with surgical treatment.</p
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