This review focuses on the initial presentation of women who suspect that they are infertile, and how best to assess the anatomy of their uterus and ovaries in order to investigate the cause of their ...infertility, and potentially improve desired fertility outcomes. This review was undertaken as part of a World Health Organization initiative to assess the evidence available to address guidance for the diagnosis and treatment of infertility within a global context. Providing access to care for infertile women will help to ease the psycho-social burdens, such as ostracization, intimate partner violence and other negative consequences of being involuntarily childless or unable to become pregnant despite desiring a biological child or children.
The aim of this paper was to present an evidence base for the diagnostic and prognostic value of various investigations used for detecting uterine and/or ovarian pathology in women presenting at fertility clinics for their initial assessment.
We performed a comprehensive search of relevant studies on 28 August and 10 September 2014. A further search was performed on 6 June 2016 to ensure all possible studies were captured. These strategies were not limited by date or language. The search returned 3968 publications in total; 63 full text articles were retrieved and 10 additional studies were found through hand-searching. After excluding 54, a total of 19 studies were analysed. We extracted and tabulated data on the characteristics, quality and results of each eligible study and combined the findings in a narrative synthesis. Risk of bias was assessed according to article type using tools such as assessment of the methodological quality of systematic reviews, Newcastle Ottawa Scale, Cochrane risk of bias tool, quality assessment tool for diagnostic accuracy studies and quality in prognostic studies. Nineteen studies were selected as being the best evidence available. A narrative synthesis of the data was undertaken. Discussion of the data, and resultant consensus for best practice were accomplished in a consensus expert consultation in Geneva, October 2015. An independent expert review process concerning this work and outcomes was conducted during 2016.
The draft recommendations presented here apply to infertile women whether or not they are undergoing fertility treatment. Transvaginal ultrasound (TVUS) should be offered to all infertile women with symptoms or signs of anatomic pelvic pathology. TVUS should not be offered routinely to women without symptoms of pelvic pathology. Hysteroscopy should be offered if intrauterine pathology is suspected by TVUS. Hysteroscopy should not be routinely offered to infertile women who have normal TVUS findings. In women who have normal TVUS findings and are undergoing IVF, hysteroscopy does not improve the outcome. Good practice points recommend that providers of fertility care should confirm that all infertile women have a recent pelvic examination, recent cervical screening and well-woman screening in line with local guidelines. Additionally, hystero-contrast salpingography in infertile women does not improve clinical pregnancy rates with expectant management in heterosexual couples and should not be offered as a therapeutic procedure. Most of the findings of this review on diagnosis are based on a low, or very low, quality of evidence, according to GRADE Working Group (grading of recommendations, assessment, development and evaluation) criteria. A low quality grading indicates that further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate, while a very low grade indicates that any estimate of effect is very uncertain.
This review provides the most reliable evidence available to guide clinicians worldwide in the initial, evidence-based investigation of women with fertility problems in order to undertake the most useful investigation and avoid the burden of unnecessary tests.
New Horizons Mission Design Guo, Yanping; Farquhar, Robert W.
Space science reviews,
10/2008, Letnik:
140, Številka:
1-4
Journal Article
Recenzirano
In the first mission to Pluto, the New Horizons spacecraft was launched on January 19, 2006, and flew by Jupiter on February 28, 2007, gaining a significant speed boost from Jupiter’s gravity assist. ...After a 9.5-year journey, the spacecraft will encounter Pluto on July 14, 2015, followed by an extended mission to the Kuiper Belt objects for the first time. The mission design for New Horizons went through more than five years of numerous revisions and updates, as various mission scenarios regarding routes to Pluto and launch opportunities were investigated in order to meet the New Horizons mission’s objectives, requirements, and goals. Great efforts have been made to optimize the mission design under various constraints in each of the key aspects, including launch window, interplanetary trajectory, Jupiter gravity-assist flyby, Pluto–Charon encounter with science measurement requirements, and extended mission to the Kuiper Belt and beyond. Favorable encounter geometry, flyby trajectory, and arrival time for the Pluto–Charon encounter were found in the baseline design to enable all of the desired science measurements for the mission. The New Horizons mission trajectory was designed as a ballistic flight from Earth to Pluto, and all energy and the associated orbit state required for arriving at Pluto at the desired time and encounter geometry were computed and specified in the launch targets. The spacecraft’s flight thus far has been extremely efficient, with the actual trajectory error correction Δ
V
being much less than the budgeted amount.
The risk of sexual transmission of HIV-1 is strongly associated with the level of HIV-1 RNA in plasma making reduction in HIV-1 plasma levels an important target for HIV-1 prevention interventions. A ...quantitative understanding of the relationship of plasma HIV-1 RNA and HIV-1 transmission risk could help predict the impact of candidate HIV-1 prevention interventions that operate by reducing plasma HIV-1 levels, such as antiretroviral therapy (ART), therapeutic vaccines, and other non-ART interventions.
We use prospective data collected from 2004 to 2008 in East and Southern African HIV-1 serodiscordant couples to model the relationship of plasma HIV-1 RNA levels and heterosexual transmission risk with confirmation of HIV-1 transmission events by HIV-1 sequencing. The model is based on follow-up of 3381 HIV-1 serodiscordant couples over 5017 person-years encompassing 108 genetically-linked HIV-1 transmission events. HIV-1 transmission risk was 2.27 per 100 person-years with a log-linear relationship to log(10) plasma HIV-1 RNA. The model predicts that a decrease in average plasma HIV-1 RNA of 0.74 log(10) copies/mL (95% CI 0.60 to 0.97) reduces heterosexual transmission risk by 50%, regardless of the average starting plasma HIV-1 level in the population and independent of other HIV-1-related population characteristics. In a simulated population with a similar plasma HIV-1 RNA distribution the model estimates that 90% of overall HIV-1 infections averted by a 0.74 copies/mL reduction in plasma HIV-1 RNA could be achieved by targeting this reduction to the 58% of the cohort with plasma HIV-1 levels ≥4 log(10) copies/mL.
This log-linear model of plasma HIV-1 levels and risk of sexual HIV-1 transmission may help estimate the impact on HIV-1 transmission and infections averted from candidate interventions that reduce plasma HIV-1 RNA levels.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary Background Antiretroviral pre-exposure prophylaxis (PrEP), with daily oral tenofovir disoproxil fumarate or tenofovir disoproxil fumarate in combination with emtricitabine, has been shown to ...be efficacious for HIV-1 prevention. Although the use of more than one antiretroviral agent is essential for effective HIV-1 treatment, more than one agent might not be required for effective prophylaxis. We assessed the efficacy of single-agent tenofovir disoproxil fumarate relative to combination emtricitabine plus tenofovir disoproxil fumarate as PrEP. Methods We did a randomised, double-blind, placebo-controlled three-group phase 3 trial of daily oral tenofovir disoproxil fumarate and emtricitabine plus tenofovir disoproxil fumarate PrEP in HIV-1 uninfected individuals in heterosexual HIV-1 serodiscordant couples from Kenya and Uganda. After an interim review, the trial's placebo group was discontinued and thereafter the active groups were continued, and participants initially randomly assigned to placebo were offered rerandomisation in a 1:1 ratio to tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate as PrEP. The primary endpoints were HIV-1 seroconversion and safety. This trial is registered with ClinicalTrials.gov , number NCT00557245. Findings 4410 (99·6%) of 4427 couples received tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate and were followed up for HIV-1 acquisition. Of 52 incident HIV-1 infections, 31 occurred in individuals assigned tenofovir disoproxil fumarate (incidence 0·71 cases per 100 person-years) and 21 were in those assigned emtricitabine plus tenofovir disoproxil fumarate (0·48 cases per 100 person-years); HIV-1 incidence in the placebo group until discontinuation was two cases per 100 person-years. HIV-1 prevention efficacy with emtricitabine plus tenofovir disoproxil fumarate was not significantly different from that of tenofovir disoproxil fumarate alone (hazard ratio HR 0·67, 95% CI 0·39–1·17; p=0·16). Detection of tenofovir in plasma samples, compared with no detection and as measured in seroconverters and a subset of non-seroconverters, was associated with an 85% relative risk reduction in HIV-1 acquisition for the tenofovir disoproxil fumarate group (HR 0·15, 95% CI 0·06–0·37; p<0·0001) and 93% for the emtricitabine plus tenofovir disoproxil fumarate group (0·07, 0·02–0·23; p<0·0001). No significant differences were noted in the frequency of deaths, serious adverse events, or serum creatinine and phosphorus abnormalities between the two groups. Interpretation These results do not rule out the potential for a slight difference in HIV-1 protection with tenofovir disoproxil fumarate compared with emtricitabine plus tenofovir disoproxil fumarate, but show that once-daily oral tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate regimens both provide high protection against HIV-1 acquisition in heterosexual men and women. Funding Bill & Melinda Gates Foundation and US National Institutes of Health.
Abstract
New tools are needed to support pre-exposure prophylaxis (PrEP) adherence for human immunodeficiency virus (HIV) prevention, including those that enable real-time feedback. In a large, ...completed PrEP trial, adequate urine tenofovir levels measured using a novel immunoassay predicted HIV protection and showed good sensitivity and specificity for detectable plasma tenofovir.
Stable heterosexual HIV-1 serodiscordant couples in Africa have high HIV-1 transmission rates and are a critical population for evaluation of new HIV-1 prevention strategies. The Partners PrEP Study ...is a randomized, double-blind, placebo-controlled trial of tenofovir and emtricitabine-tenofovir pre-exposure prophylaxis to decrease HIV-1 acquisition within heterosexual HIV-1 serodiscordant couples. We describe the trial design and characteristics of the study cohort.
HIV-1 serodiscordant couples, in which the HIV-1 infected partner did not meet national guidelines for initiation of antiretroviral therapy, were enrolled at 9 research sites in Kenya and Uganda. The HIV-1 susceptible partner was randomized to daily oral tenofovir, emtricitabine-tenofovir, or matching placebo with monthly follow-up for 24-36 months.
From July 2008 to November 2010, 7920 HIV-1 serodiscordant couples were screened and 4758 enrolled. For 62% (2966/4758) of enrolled couples, the HIV-1 susceptible partner was male. Median age was 33 years for HIV-1 susceptible and HIV-1 infected partners IQR (28-40) and (26-39) respectively. Most couples (98%) were married, with a median duration of partnership of 7.0 years (IQR 3.0-14.0) and recent knowledge of their serodiscordant status median 0.4 years (IQR 0.1-2.0). During the month prior to enrollment, couples reported a median of 4 sex acts (IQR 2-8); 27% reported unprotected sex and 14% of male and 1% of female HIV-1 susceptible partners reported sex with outside partners. Among HIV-1 infected partners, the median plasma HIV-1 level was 3.94 log(10) copies/mL (IQR 3.31-4.53) and median CD4 count was 496 cells/µL (IQR 375-662); the majority (64%) had WHO stage 1 HIV-1 disease.
Couples at high risk of HIV-1 transmission were rapidly recruited into the Partners PrEP Study, the largest efficacy trial of oral PrEP. (ClinicalTrials.gov NCT00557245).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A new dedicated PET scanner, microPET, was designed and developed at the University of California, Los Angeles, for imaging small laboratory animals. The goal was to provide a compact system with ...superior spatial resolution at a fraction of the cost of a clinical PET scanner.
The system uses fiberoptic readout of individually cut lutetium oxyorthosilicate (LSO) crystals to achieve high spatial resolution. Each microPET detector consists of an 8 x 8 array of 2 x 2 x 10-mm LSO scintillation crystals that are coupled to a 64-channel photomultiplier tube by optical fibers. The tomograph consists of 30 detectors in a continuous ring with a 17.2-cm diameter and fields of view (FOVs) of 11.25 cm in the transaxial direction and 1.8 cm in the axial direction. The system has eight crystal rings and no interplane septa. It operates exclusively in the three-dimensional mode and has an electronically controlled bed that is capable of wobbling with a radius of 300 microm. We describe the performance of the tomograph in terms of its spatial, energy and timing resolution, as well as its sensitivity and counting-rate performance. We also illustrate its overall imaging performance with phantom and animal studies that demonstrate the potential applications of this device to biomedical research.
Images reconstructed with three-dimensional filtered backprojection show a spatial resolution of 1.8 mm at the center of the FOV (CFOV), which remains <2.5 mm for the central 5 cm of the transaxial FOV. The resulting volumetric resolution of the system is <8 microL. The absolute system sensitivity measured with a 0.74 MBq (20 microCi) 68Ge point source at the CFOV is 5.62 Hz/kBq. The maximum noise equivalent counting rate obtained with a 6.4-cm diameter cylinder spanning the central 56% of the FOV is 10 kcps, whereas the scatter fraction is 37% at the CFOV for an energy window of 250-650 keV and the same diameter cylinder.
This is the first PET scanner to use the new scintillator LSO and uses a novel detector design to achieve high volumetric spatial resolution. The combination of imaging characteristics of this prototype system (resolution, sensitivity, counting-rate performance and scatter fraction) opens up new possibilities in the study of animal models with PET.
A plan to use the Sun–Earth L2 libration point as the primary hub for future human space activities in the Earth's neighborhood is described. It is expected that the Sun–Earth L2 point will be the ...location of choice for a number of large astronomical observatories over the next 20 years. These observatories will probably require some level of servicing and/or repair by astronauts. To provide human access to the L2 point, the early development of a reusable vehicle called a Deep-Space Shuttle (DSS) is proposed. The DSS, based in low-Earth orbit, would be able to transport astronauts to and from the L2 point in about 35 days (including a 5-day stay time at L2). The Sun–Earth L2 point is also useful as a staging node for missions to near-Earth asteroids and Mars. For instance, a reusable interplanetary transfer vehicle (ITV) stationed at the L2 point could be used for the round-trip journey. The ITV would use lunar gravity-assists and a perigee Δ
V maneuver to enter the desired interplanetary transfer trajectory. Just prior to the Earth-escape maneuver, a DSS “taxi” would transfer the crew to the ITV. A reverse procedure would be used to return the ITV to the libration point with the crew leaving the ITV just before the Earth-capture maneuver, and returning directly to Earth via an Apollo-style re-entry capsule. Using this technique, the L2-based ITV would save approximately
6.3
km/
s
in Δ
V cost compared with an ITV stationed in low-Earth orbit.
Background. Intermittent shedding of human immunodeficiency virus type 1 (HIV) in semen occurs despite effective antiretroviral therapy (ART) and suppressed blood HIV-1 RNA levels. Methods. We ...assessed the frequency, magnitude, and correlates of seminal HIV-1 RNA shedding in HIV-1-infected African men initiating ART. Results. Seminal HIV-1 RNA was detected in 24% (37 of 155), 10% (5 of 49), and 11% (8 of 70) of samples collected 0-3, 4-6, and >6 months after ART initiation. When blood HIV-1 levels were suppressed, seminal HIV-1 RNA was detected in 8% (16 of 195), and 82% (13 of 16) had an HIV-1 RNA load of < 1000 copies/mL. Conclusions. Seminal HIV-1 RNA shedding was infrequent and present at low levels in HIV-1-infected African men with suppressed blood HIV-1 RNA.
Genital HIV shedding was infrequent among women on antiretroviral therapy (ART) with undetectable plasma viral load, and was associated with advanced disease, time on ART, and genital ulcers. ...Treating genital tract infections may further decrease HIV-1 shedding and potential transmission.
Abstract
Background
Genital human immunodeficiency virus (HIV) RNA shedding can continue despite HIV being undetectable in blood, and can be associated with transmission.
Methods
We included African women on antiretroviral therapy (ART). Linear and generalized linear mixed models were used to compare the magnitude and prevalence of genital shedding, respectively, by time since ART initiation. Multivariable logistic regression with generalized estimating equations was used to assess predictors of genital shedding among women with undetectable plasma viral load (VL).
Results
Among 1114 women, 5.8% of visits with undetectable plasma VL and 23.6% of visits with detectable VL had genital shedding. The proportion of visits with genital shedding decreased with time since ART initiation but the magnitude of shedding remained unchanged when plasma VL was undetectable (P = .032). Prevalence of shedding did not vary by time since ART initiation when plasma VL was detectable (P = .195), though the magnitude of shedding significantly increased (P = .04). Predictors of genital shedding were HIV disease stage, antiretroviral regimen, and genital ulcers or cervical tenderness.
Discussion
In addition to ART, reducing immune activation through prevention and treatment of HIV-related conditions and genital tract infections may decrease the risk of HIV-1 shedding and potential transmission.
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