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111.
BackgroundWomen with obesity and infertility are counseled to lose weight prior to conception and infertility treatment to improve pregnancy rates and birth outcomes, although confirmatory evidence from randomized trials is lacking. We assessed whether a preconception intensive lifestyle intervention with acute weight loss is superior to a weight neutral intervention at achieving a healthy live birth.Methods and findingsIn this open-label, randomized controlled study (FIT-PLESE), 379 women with obesity (BMI ≥ 30 kg/m2) and unexplained infertility were randomly assigned in a 1:1 ratio to 2 preconception lifestyle modification groups lasting 16 weeks, between July 2015 and July 2018 (final follow-up September 2019) followed by infertility therapy. The primary outcome was the healthy live birth (term infant of normal weight without major anomalies) incidence. This was conducted at 9 academic health centers across the United States. The intensive group underwent increased physical activity and weight loss (target 7%) through meal replacements and medication (Orlistat) compared to a standard group with increased physical activity alone without weight loss. This was followed by standardized empiric infertility treatment consisting of 3 cycles of ovarian stimulation/intrauterine insemination. Outcomes of any resulting pregnancy were tracked. Among 191 women randomized to standard lifestyle group, 40 dropped out of the study before conception; among 188 women randomized to intensive lifestyle group, 31 dropped out of the study before conception. All the randomized women were included in the intent-to-treat analysis for primary outcome of a healthy live birth. There were no significant differences in the incidence of healthy live births [standard 29/191(15.2%), intensive 23/188(12.2%), rate ratio 0.81 (0.48 to 1.34), P = 0.40]. Intensive had significant weight loss compared to standard (−6.6 ± 5.4% versus −0.3 ± 3.2%, P < 0.001). There were improvements in metabolic health, including a marked decrease in incidence of the metabolic syndrome (baseline to 16 weeks: standard: 53.6% to 49.4%, intensive 52.8% to 32.2%, P = 0.003). Gastrointestinal side effects were significantly more common in intensive. There was a higher, but nonsignificant, first trimester pregnancy loss in the intensive group (33.3% versus 23.7% in standard, 95% rate ratio 1.40, 95% confidence interval [CI]: 0.79 to 2.50). The main limitations of the study are the limited power of the study to detect rare complications and the design difficulty in finding an adequate time matched control intervention, as the standard exercise intervention may have potentially been helpful or harmful.ConclusionsA preconception intensive lifestyle intervention for weight loss did not improve fertility or birth outcomes compared to an exercise intervention without targeted weight loss. Improvement in metabolic health may not translate into improved female fecundity.Trial registrationClinicalTrials.gov NCT02432209.

Richard Legro and colleagues investigate the impact of a preconception weight loss intervention on healthy live birth rates in women with obesity and unexplained infertility.  相似文献   
112.
端粒酶的研究进展   总被引:4,自引:0,他引:4  
端粒酶是由RNA模板和蛋白质催化亚基组成的核糖蛋白颗粒,它解决染色体的未端复制问题,归属于逆转录酶家族又和逆转录酶有一定的差别。端粒酶的缺失能在细胞和机体水平引起各种疾病的发生,且端粒的过度表达和细胞的永生化和癌变直接相关,其中端粒蛋白在此过程中可能起调控作用,端粒酶的结构和功能决定了它有广泛的应用前景。  相似文献   
113.
BackgroundHospitalized preterm infants with compromised skin barrier function treated topically with sunflower seed oil (SSO) have shown reductions in sepsis and neonatal mortality rate (NMR). Mustard oil and products commonly used in high-mortality settings may possibly harm skin barrier integrity and enhance risk of infection and mortality in newborn infants. We hypothesized that SSO therapy may reduce NMR in such settings.Methods and findingsThis was a population-based, cluster randomized, controlled trial in 276 clusters in rural Uttar Pradesh, India. All newborn infants identified through population-based surveillance in the study clusters within 7 days of delivery were enrolled from November 2014 to October 2016. Exclusive, 3 times daily, gentle applications of 10 ml of SSO to newborn infants by families throughout the neonatal period were recommended in intervention clusters (n = 138 clusters); infants in comparison clusters (n = 138 clusters) received usual care, such as massage practice typically with mustard oil. Primary analysis was by intention-to-treat with NMR and post-24-hour NMR as the primary outcomes. Secondary analysis included per-protocol analysis and subgroup analyses for NMR. Regression analysis was adjusted for caste, first-visit weight, delivery attendant, gravidity, maternal age, maternal education, sex of the infant, and multiple births. We enrolled 13,478 (52.2% male, mean weight: 2,575.0 grams ± standard deviation [SD] 521.0) and 13,109 (52.0% male, mean weight: 2,607.0 grams ± SD 509.0) newborn infants in the intervention and comparison clusters, respectively. We found no overall difference in NMR in the intervention versus the comparison clusters [adjusted odds ratio (aOR) 0.96, 95% confidence interval (CI) 0.84 to 1.11, p = 0.61]. Acceptance of SSO in the intervention arm was high at 89.3%, but adherence to exclusive applications of SSO was 30.4%. Per-protocol analysis showed a significant 58% (95% CI 42% to 69%, p < 0.01) reduction in mortality among infants in the intervention group who were treated exclusively with SSO as intended versus infants in the comparison group who received exclusive applications of mustard oil. A significant 52% (95% CI 12% to 74%, p = 0.02) reduction in NMR was observed in the subgroup of infants weighing ≤1,500 g (n = 589); there were no statistically significant differences in other prespecified subgroup comparisons by low birth weight (LBW), birthplace, and wealth. No severe adverse events (SAEs) were attributable to the intervention. The study was limited by inability to mask allocation to study workers or participants and by measurement of emollient use based on caregiver responses and not actual observation.ConclusionsIn this trial, we observed that promotion of SSO therapy universally for all newborn infants was not effective in reducing NMR. However, this result may not necessarily establish equivalence between SSO and mustard oil massage in light of our secondary findings. Mortality reduction in the subgroup of infants ≤1,500 g was consistent with previous hospital-based efficacy studies, potentially extending the applicability of emollient therapy in very low-birth-weight (VLBW) infants along the facility–community continuum. Further research is recommended to develop and evaluate therapeutic regimens and continuum of care delivery strategies for emollient therapy for newborn infants at highest risk of compromised skin barrier function.Trial registrationISRCTN Registry ISRCTN38965585 and Clinical Trials Registry—India (CTRI/2014/12/005282) with WHO UTN # U1111-1158-4665.

In a cluster randomized trial, Aarti Kumar and colleagues study the effectiveness of a topical sunflower seed oil therapy in reducing neonatal mortality in Uttar Pradesh, India.  相似文献   
114.
The synthesis of adrenal steroids requires molecular oxygen. Because arterial hypoxemia is a common clinical condition, the purpose of the present study was to examine steroidogenesis in vitro under physiological changes in O(2) tension (Po(2)) in cells from human adrenal glands with aldosterone-secreting adenomas (ASA; n=3) or with bilateral adrenal hyperplasia causing Cushing's syndrome (n=4). A decrease in Po(2) from 150 mmHg (mild hyperoxia) to 80 mmHg had minimal effect on steroid production. A reduction to 40 mmHg (still well within the physiological range) significantly inhibited cAMP- and ACTH-stimulated aldosterone, cortisol, and dehydroepiandrosterone (DHEA) production from ASA. Furthermore, cortisol and DHEA production in cells from histologically normal tissue, adjacent to ASA and from bilateral adrenal hyperplasias, was also inhibited under a Po(2) of 40 mmHg. We conclude that physiological decreases in Po(2) to levels typical for adrenal venous Po(2) under mild hypoxia inhibit steroidogenesis. These studies may have implications for oxygen therapy in critically ill patients with functional adrenal insufficiency, as well as for therapeutic options in patients with adrenal neoplasms.  相似文献   
115.

Background

Total serum immunoglobulin (IgE) test is usually performed to aid in the diagnosis of allergic diseases, but its reference values may vary among people of different ethnic backgrounds.

Objectives

To establish reference values of total IgE in Asian children and to assess their significance in the diagnosis of atopy and allergic diseases.

Study design

1321 Asian children aged 5-18 years in the Prediction of Allergies in Taiwanese CHildren (PATCH) study, a population-based cohort, were evaluated for total and specific IgE by ImmunoCAP and Phadiatop Infant, respectively.

Results

Male, atopy, allergic diseases, recent symptoms of upper respiratory infection, and lower FEV1/FVC, were associated with higher total IgE levels in univariate analyses. Multivariate analysis revealed that atopy was the single most important determinant explaining 66.1% of the variability of total IgE levels in this population. The area under the receiver-operator characteristic (ROC) curve of total IgE for diagnosing atopy, asthma, rhinitis, and eczema were 0.92, 0.72, 0.70, and 0.70, respectively. The sensitivity, specificity, and positive and negative predictive values of total IgE at the optimal cutoff of 77.7 kU/L on the ROC curve for diagnosing atopy were 82.3%, 87.1%, 89.5%, and 78.6%, respectively. The corresponding values using the upper 95% CI of total IgE (164.3 kU/L) in non-atopic children were 61.2%, 95.0%, 94.3%, and 64.6%, respectively; whereas a customary cutoff (100 kU/L) provided accuracy between that of the aforementioned two cutoffs. Total IgE at the cutoff of 77.7 kU/L provided modest sensitivity and specificity (49.0%-78.3%) for diagnosing allergic diseases, but had high negative predictive values (84.2%-97.9%).

Conclusions

Total serum IgE discriminates Asian children with and without atopy independent of allergic symptoms, with an optimal cutoff of 77.7 kU/L. The study confirms the insufficient diagnostic accuracy of total IgE alone to detect allergic diseases, but low total IgE levels may help exclude allergic diseases.  相似文献   
116.
Identification of domains in IL-16 critical for biological activity.   总被引:5,自引:0,他引:5  
IL-16 is a proinflammatory cytokine implicated in the pathogenesis of asthma and other conditions characterized by recruitment of CD4+ T cells to sites of disease. It is postulated that CD4 is an IL-16 receptor, although other receptors or coreceptors may exist. Among several known functions, IL-16 is a chemoattractant factor for CD4+ T cells and it inhibits MLR. We previously reported that an oligopeptide corresponding to the 16 C-terminal residues of human IL-16 inhibits chemoattractant activity. To identify functional domains with greater precision, shorter oligonucleotides containing native or mutated C-terminal IL-16 sequences were tested for IL-16 inhibition. Within the 16 C-terminal residues, the minimal peptide RRKS (corresponding to Arg106 to Ser109) was shown to mediate inhibition of IL-16 chemoattractant activity. Inhibition was lost when either arginine was substituted with alanine. Point mutations in IL-16 revealed that Arg107 is critical for chemoattractant activity, but MLR inhibition was unaffected by mutation of Arg107 or even deletion of the C-terminal tail through Arg106. Deletion of 12 or 22 N-terminal residues of IL-16 had no impact on chemoattractant activity, but MLR inhibition was reduced. Deletion of 16 C-terminal plus 12 N-terminal residues abolished both chemoattractant and MLR-inhibitory activity of IL-16. These data indicate that receptor interactions with IL-16 that activate T cell migration are not identical with those required for MLR inhibition, and suggest that both N-terminal and C-terminal domains in IL-16 participate in receptor binding or activation.  相似文献   
117.
118.

Background

A set of nomograms based on the Dubbo Osteoporosis Epidemiology Study predicts the five- and ten-year absolute risk of fracture using age, bone mineral density and history of falls and low-trauma fracture. We assessed the discrimination and calibration of these nomograms among participants in the Canadian Multicentre Osteoporosis Study.

Methods

We included participants aged 55–95 years for whom bone mineral density measurement data and at least one year of follow-up data were available. Self-reported incident fractures were identified by yearly postal questionnaire or interview (years 3, 5 and 10). We included low-trauma fractures before year 10, except those of the skull, face, hands, ankles and feet. We used a Cox proportional hazards model.

Results

Among 4152 women, there were 583 fractures, with a mean follow-up time of 8.6 years. Among 1606 men, there were 116 fractures, with a mean follow-up time of 8.3 years. Increasing age, lower bone mineral density, prior fracture and prior falls were associated with increased risk of fracture. For low-trauma fractures, the concordance between predicted risk and fracture events (Harrell C) was 0.69 among women and 0.70 among men. For hip fractures, the concordance was 0.80 among women and 0.85 among men. The observed fracture risk was similar to the predicted risk in all quintiles of risk except the highest quintile of women, where it was lower. The net reclassification index (19.2%, 95% confidence interval [CI] 6.3% to 32.2%), favours the Dubbo nomogram over the current Canadian guidelines for men.

Interpretation

The published nomograms provide good fracture-risk discrimination in a representative sample of the Canadian population.Current recommendations for the treatment of osteoporosis are in transition. The T-score-based definition of osteoporosis and osteopenia by the expert committee of the World Health Organization on bone mineral density has been used in many guidelines to set intervention thresholds for treatment. However, studies have consistently reported that the highest number of fractures in a given population occurs in those with osteopenic or normal bone mineral density.1,2 In fact, the National Osteoporosis Foundation has singled out people with osteopenic bone mineral density as a population in which assessment for fracture risk is merited.3Nevertheless, appropriate prevention and treatment strategies for such people are uncertain.4 Recent developments include the assessment of absolute fracture risk based on bone mineral density and other risk factors. Current Canadian methodology determines categorical risk based on age, sex, T-score, fracture history and glucocorticoid use.5 These criteria were derived from Swedish data, but have been assessed and validated in a cohort of Manitoba women.6 Newer nomograms based on the Australian cohort of the Dubbo Osteoporosis Epidemiology Study7 are now available for the calculation of low-trauma hip fracture8 and any fracture.9 These nomograms provide continuous estimates for five- and 10-year absolute fracture risk in both men and women (available at http://fractureriskcalculator.com). The use of factors in addition to bone mineral density may provide a better assessment of fracture risk for people who are near the T-score thresholds and facilitate decisions regarding therapeutic intervention.A key step in the development of any prediction model is the assessment of its validity.10 The aim of our study was to assess the performance of the Australian-derived nomogram among community-dwelling Canadians aged 55–95 years old. The first part of this assessment was a comparison of the nomogram model using the same variables, but using data from a Canadian population — participants in the Canadian Multicentre Osteoporosis Study (www.camos.org). The second part involved computing the calibration and discrimination of the nomogram in a Canadian cohort. The final part was comparison of the new assessments with the existing Canadian risk classification system.  相似文献   
119.
The mechanisms that cause T cell recruitment into inflamed airways of asthmatic individuals are poorly understood. It has been shown previously that both natural exposure to allergen and challenge in the laboratory induce T cell accumulation in the bronchial mucosa of sensitized asthmatics. To study the mechanisms involved in this process, we have used an explant model in which bronchial biopsies taken from mild atopic asthmatic volunteers during fiberoptic bronchoscopy were stimulated in culture for 24 h by the common aeroallergen house dust mite (Dermatophagoides pteronyssinus (Der p)). Analysis of culture supernatants showed that stimulation with Der p significantly enhanced both the generation of T cell chemotactic activity by the mucosal tissue, as assayed in microchemotaxis chambers, and the production of IL-16 and RANTES. Neutralization experiments showed that IL-16 contributed more to the chemotactic activity than RANTES. The fusion protein CTLA-4-Ig, blocking B7:CD28 costimulation, and dexamethasone both significantly reduced the ex vivo production of chemotactic activity and release of IL-16 and RANTES. The proteasome inhibitor Cbz-Ile-Glu(OtBu)-Ala-leucinal also had a significant inhibitory effect on T cell chemotactic activity and IL-16 but not RANTES generation, indicating a role for nuclear factor NF kappa B activation. These results indicate that allergen stimulates cells within the bronchial mucosa to increase IL-16 and RANTES release, both of which contribute to T cell accumulation in asthmatic airways. The allergen-induced chemotactic activity is dependent on cell activation via CD28 and involves, at least partly, NF-kappa B.  相似文献   
120.

Background

HIV-1 RNA plasma concentration at viral set-point is associated not only with disease outcome but also with the transmission dynamics of HIV-1. We investigated whether plasma HIV-1 RNA concentration and CD4 cell count at viral set-point have changed over time in the HIV epidemic in the Netherlands.

Methodology/Principal Findings

We selected 906 therapy-naïve patients with at least one plasma HIV-1 RNA concentration measured 9 to 27 months after estimated seroconversion. Changes in HIV-1 RNA and CD4 cell count at viral set-point over time were analysed using linear regression models. The ATHENA national observational cohort contributed all patients who seroconverted in or after 1996; the Amsterdam Cohort Studies (ACS) contributed seroconverters before 1996. The mean of the first HIV-1 RNA concentration measured 9–27 months after seroconversion was 4.30 log10 copies/ml (95% CI 4.17–4.42) for seroconverters from 1984 through 1995 (n = 163); 4.27 (4.16–4.37) for seroconverters 1996–2002 (n = 232), and 4.59 (4.52–4.66) for seroconverters 2003–2007 (n = 511). Compared to patients seroconverting between 2003–2007, the adjusted mean HIV-1 RNA concentration at set-point was 0.28 log10 copies/ml (95% CI 0.16–0.40; p<0.0001) and 0.26 (0.11–0.41; p = 0.0006) lower for those seroconverting between 1996–2002 and 1984–1995, respectively. Results were robust regardless of type of HIV-1 RNA assay, HIV-1 subtype, and interval between measurement and seroconversion. CD4 cell count at viral set-point declined over calendar time at approximately 5 cells/mm3/year.

Conclusion

The HIV-1 RNA plasma concentration at viral set-point has increased over the last decade of the HIV epidemic in the Netherlands. This is accompanied by a decreasing CD4 cell count over the period 1984–2007 and may have implications for both the course of the HIV infection and the epidemic.  相似文献   
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