Rising School Enrollment and Declining HIV and Pregnancy Risk Among Adolescents in Rakai District, Uganda, 1994-2013

BACKGROUND

Poverty, family stability, and social policies influence the ability of adolescents to attend school. Likewise, being enrolled in school may shape an adolescent's risk for HIV and pregnancy. We identified trends in school enrollment, factors predicting school enrollment (antecedents), and health risks associated with staying in or leaving school (consequences).

METHODS

Data from the Rakai Community Cohort Study (RCCS) were examined for adolescents 15-19 years (n=21,735 person-rounds) from 1994 to 2013. Trends, antecedents, and consequences were assessed using logistic and linear regression with robust variance estimation. Qualitative data were used to explore school leaving among HIV+ and HIV- youth (15-24 years).

RESULTS

School enrollment and socioeconomic status (SES) rose steadily from 1994 to 2013 among adolescents; orphanhood declined after availability of antiretroviral therapy. Antecedent factors associated with school enrollment included age, SES, orphanhood, marriage, family size, and the percent of family members <20 years. In qualitative interviews, youth reported lack of money, death of parents, and pregnancy as primary reasons for school dropout. Among adolescents, consequences associated with school enrollment included lower HIV prevalence, prevalence of sexual experience, and rates of alcohol use and increases in consistent condom use. Young women in school were more likely to report use of modern contraception and never being pregnant. Young men in school reported fewer recent sexual partners and lower rates of sexual concurrency.

CONCLUSIONS

Rising SES and declining orphanhood were associated with rising school enrollment in Rakai. Increasing school enrollment was associated with declining risk for HIV and pregnancy.

DNA methylation, its mediators and genome integrity

DNA methylation regulates many cellular processes, including embryonic development, transcription, chromatin structure, X-chromosome inactivation, genomic imprinting and chromosome stability. DNA methyltransferases establish and maintain the presence of 5-methylcytosine (5mC), and ten-eleven translocation cytosine dioxygenases (TETs) oxidise 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC), which can be removed by base excision repair (BER) proteins. Multiple forms of DNA methylation are recognised by methyl-CpG binding proteins (MeCPs), which play vital roles in chromatin-based transcriptional regulation, DNA repair and replication. Accordingly, defects in DNA methylation and its mediators may cause silencing of tumour suppressor genes and misregulation of multiple cell cycles, DNA repair and chromosome stability genes, and hence contribute to genome instability in various human diseases, including cancer. Thus, understanding functional genetic mutations and aberrant expression of these DNA methylation mediators is critical to deciphering the crosstalk between concurrent genetic and epigenetic alterations in specific cancer types and to the development of new therapeutic strategies.

Polyunsaturated fatty acids in relation to incident mobility disability and decline in gait speed; the Age, Gene/Environment Susceptibility-Reykjavik Study

BACKGROUND/OBJECTIVES

Low intake of long chain polyunsaturated fatty acids (PUFAs) are associated with physical disability; however, prospective studies of circulating PUFAs are scarce. We examined associations between plasma phospholipid n-3 and n-6 PUFAs with risk of incident mobility disability and gait speed decline.

SUBJECTS/METHODS

Data are from a subgroup of the Age, Gene/Environment Susceptibility-Reykjavik Study, a population-based study of risk factors for disease and disability in old age. In this subgroup (n = 556, mean age 75.1 ± 5.0 years, 47.5% men), plasma phospholipid PUFAs were assessed at baseline using gas chromatography. Mobility disability and usual gait speed were assessed at baseline and after 5.2 ± 0.2 years. Mobility disability was defined as the following: having much difficulty, or being unable to walk 500 m or climb up 10 steps; decline in gait speed was defined as change ⩾ 0.10 m/s. Logistic regression analyses were performed to determine associations between sex-specific s.d. increments in PUFAs with risk of incident mobility disability and gait speed decline. Odds ratios (95% confidence intervals) adjusted for demographics, follow-up time, risk factors and serum vitamin D were reported.

RESULTS

In women, but not men, every s.d. increment increase of total n-3 PUFAs and docosahexaenoic acid (DHA) was associated with lower mobility disability risk, odds ratio 0.48 (0.25; 0.93) and odds ratio 0.45 (0.24; 0.83), respectively. There was no association between n-6 PUFAs and the risk of incident mobility disability or gait speed decline.

CONCLUSIONS

Higher concentrations of n-3 PUFAs and, particularly, DHA may protect women from impaired mobility but does not appear to have such an effect in men.

Genome-wide association study of myelosuppression in non-small-cell lung cancer patients with platinum-based chemotherapy

Platinum-induced myelosuppression severely impedes successful chemotherapy in non-small-cell lung cancer (NSCLC) patients. Hence, it is clinically important to identify the patients who are at high risk for severe toxicity to certain chemotherapy. We first carried out a genome-wide scan of 906 703 single-nucleotide polymorphisms (SNPs) to identify genetic variants associated with platinum-induced myelosuppression risk in 333 NSCLC patients with chemotherapy. Then, we replicated 24 SNPs that had P<1 × 10(-4) in another independent cohort of 876 NSCLC patients. With P<0.05 as the criterion of statistical significance, we found that rs13014982 at 2q24.3 and rs9909179 at 17p12 exhibited consistently significant associations with myelosuppression risk in both the genome-wide association studies (GWAS) scan and the replication stage (rs13014982: odds ratio (OR)=0.55, 95% confidence intervals (CIs): 0.41-0.74, P=7.29 × 10(-5) for GWAS scan and OR=0.77, 95% CI: 0.65-0.93, P=0.006 for replication stage; rs9909179: OR=0.51, 95% CI: 0.37-0.70, P=4.60 × 10(-5) for GWAS scan and OR=0.82, 95% CI: 0.68-0.99, P=0.040 for replication stage; both in additive model). In combined samples of genome-wide scan and replication samples, the minor alleles of rs13014982 and rs9909179 remained significant associations with the decreased risk of myelosuppression (rs13014982: OR=0.71, 95% CI: 0.61-0.83, P =1.36 × 10(-5); rs9909179: OR=0.76, 95% CI: 0.65-0.89, P=0.001). Rs13014982 at 2q24.3 and rs9909179 at 17p12 might be independent susceptibility markers for platinum-induced myelosuppression risk in NSCLC patients.

Cardiovascular and all-cause mortality in relation to various anthropometric measures of obesity in Europeans

BACKGROUND AND AIMS

Cardiovascular and all-cause mortality in relation to various anthropometric measures of obesity is still controversial.

METHODS AND RESULTS

Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), A Body Shape Index (ABSI) and waist-to-hip-to-height ratio (WHHR) were measured at baseline in a cohort of 46,651 European men and women aged 24-99 years. The relationship between anthropometric measures of obesity and mortality was evaluated by the Cox proportional hazards model with age as a time-scale and with threshold detected by a piecewise regression model. Over a median follow-up of 7.9 years, 2381 men and 1055 women died, 1071 men (45.0%) and 339 women (32.1%) from cardiovascular disease (CVD). BMI had a J-shaped relationship with CVD mortality, whereas anthropometric measures of abdominal obesity had positive linear relationships. BMI, WC and WHtR showed J-shaped associations with all-cause mortality, whereas WHR, ABSI and WHHR demonstrated positive linear relationships. Accordingly, a threshold value was detected at 29.29 and 30.98 kg/m(2) for BMI, 96.4 and 93.3 cm for WC, 0.57 and 0.60 for WHtR, 0.0848 and 0.0813 m(11/6) kg(-2/3) for ABSI with CVD mortality in men and women, respectively; 29.88 and 29.50 kg/m(2) for BMI, 104.3 and 105.6 for WC, 0.61 and 0.67 for WHtR, 0.95 and 0.86 for WHR, 0.0807 and 0.0765 for ABSI in men and women, respectively, and 0.52 for WHHR in women with all-cause mortality.

CONCLUSION

All anthropometric measures of abdominal obesity had positive linear associations with CVD mortality, whereas some showed linear and the others J-shaped relationships with all-cause mortality. BMI had a J-shaped relationship with either CVD or all-cause mortality. Thresholds detected based on mortality may help with clinical definition of obesity in relation to mortality.

Comparison of extraction methods of total microbial DNA from freshwater

The demand for molecular analysis of aquatic microbial communities in freshwater has highlighted the need for efficient methods of DNA extraction. The centrifugation method and filtration-membrane method are 2 widely used methods for extracting DNA. The objective of this study was to compare the extraction efficiency of 3 methods, including the centrifugation method, filtration-membrane method, and modified filtration-membrane method, by evaluating the quantity and purity of DNA extracts obtained from water. DNA extraction was analyzed by agarose gel electrophoresis, ultraviolet-spectroscopy, restriction enzyme digestion, and polymerase chain reaction. The results showed that the modified filtration-membrane method was the most efficient for extracting microbial DNA from freshwater with high integrity and purity and is suitable for molecular applications.

An evaluation comparing Californium252 neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy assisted surgery effect for treating advanced cervical carcinoma patients

PURPOSE OF INVESTIGATION

To compare the therapeutic and side effects of using Californium252 (252Cf) neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy in combination with surgery for treating Stage Ib2-IIb cervical cancers (CCs).

MATERIALS AND METHODS

Thirty-two Stage Ib2-IIb CC patients were enrolled and randomly divided into two groups from January 2007 to April 2010 in the present Hospital. Prior to surgery within four weeks, a total of 17 cases were treated with 252Cf neutron brachytherapy (700-800 cGy doses at point A) once a week (Group A), and 15 cases were treated by neoadjuvant intra-arterial embolism chemotherapy using a combination of bleomycin, carboplatin, and cyclophosphamide twice (Group B). The clinical symptoms and signs, side effects, and relapse condition follow up until July 2013 were compared between the two groups for the perioperation.

RESULTS

Reductions in tumor mass and CR+PR were not significantly different between the groups before the surgery (p > 0.05). Abdominal pain and pelvic adhesions were significantly more severe in Group B (p < 0.05). There were no significant differences in surgical time, blood loss or the other side effects between Groups A and B (p > 0.05). The percentage of pelvic tumor recurrences in Group A was lower than that of the patients in Group B (11.8% vs 20.0%) although with no significant difference at present. No distant metastasis has been found in both two groups.

CONCLUSION

Except for less abdominal pain and pelvic adhesions, 252Cf neutron brachytherapy has perioperative effects similar to those of neoadjuvant intra-arterial embolism chemotherapy.

Obstructive sleep apnea and serious adverse outcomes in patients with cardiovascular or cerebrovascular disease: a PRISMA-compliant systematic review and meta-analysis

Obstructive sleep apnea (OSA) is seen in approximately 60% to 70% of patients with stroke or ischemic heart disease (IHD). The relationship between OSA and recurrent vascular events and all-cause mortality remains inconclusive. We aimed to systematically evaluate the associations between OSA and serious adverse outcomes following stroke or IHD by a meta-analysis of prospective cohort studies. We searched MEDLINE and EMBASE in August 2014 for studies that evaluated the prospective associations between OSA and the risk of stroke, IHD, and death among stroke or IHD patients. Outcome data were pooled using random effects meta-analysis. Subgroup, heterogeneity, and sensitivity analyses and publication bias were performed. Of 13 hospital-based cohort studies included, 5 reported results on stroke (n = 860), 6 reported on IHD (n = 1083), and 11 reported on all-cause death or cardiovascular death (n = 1930). OSA was significantly associated with the risk of stroke, IHD, and all-cause mortality after stroke or IHD. The pooled relative risks were 1.94 (95% confidence interval [CI], 1.29-2.92) for stroke, 1.83 (95% CI, 1.15-2.93) for IHD, and 1.59 (95% CI, 1.33-1.89) for all-cause mortality. There was no evidence of significant between-study heterogeneity. The results did not materially change in the sensitivity analyses for the outcomes of stroke and all-cause mortality. OSA may be a significant predictor of serious adverse outcomes following stroke or IHD. More high-quality studies are needed to determine if better treatment of OSA leads to fewer recurrent vascular events, especially a large-scale, multicenter randomized-controlled trial.

Role of AMP-activated protein kinase in cross-talk between apoptosis and autophagy in human colon cancer

Unresectable colorectal liver metastases remain a major unresolved issue and more effective novel regimens are urgently needed. While screening synergistic drug combinations for colon cancer therapy, we identified a novel multidrug treatment for colon cancer: chemotherapeutic agent melphalan in combination with proteasome inhibitor bortezomib and mTOR (mammalian target of rapamycin) inhibitor rapamycin. We investigated the mechanisms of synergistic antitumor efficacy during the multidrug treatment. All experiments were performed with highly metastatic human colon cancer CX-1 and HCT116 cells, and selected critical experiments were repeated with human colon cancer stem Tu-22 cells and mouse embryo fibroblast (MEF) cells. We used immunochemical techniques to investigate a cross-talk between apoptosis and autophagy during the multidrug treatment. We observed that melphalan triggered apoptosis, bortezomib induced apoptosis and autophagy, rapamycin caused autophagy and the combinatorial treatment-induced synergistic apoptosis, which was mediated through an increase in caspase activation. We also observed that mitochondrial dysfunction induced by the combination was linked with altered cellular metabolism, which induced adenosine monophosphate-activated protein kinase (AMPK) activation, resulting in Beclin-1 phosphorylated at Ser 93/96. Interestingly, Beclin-1 phosphorylated at Ser 93/96 is sufficient to induce Beclin-1 cleavage by caspase-8, which switches off autophagy to achieve the synergistic induction of apoptosis. Similar results were observed with the essential autophagy gene, autophagy-related protein 7, -deficient MEF cells. The multidrug treatment-induced Beclin-1 cleavage was abolished in Beclin-1 double-mutant (D133A/D146A) knock-in HCT116 cells, restoring the autophagy-promoting function of Beclin-1 and suppressing the apoptosis induced by the combination therapy. These observations identify a novel mechanism for AMPK-induced apoptosis through interplay between autophagy and apoptosis.

Superresolution imaging reveals structural features of EB1 in microtubule plus-end tracking

A method is introduced for optically imaging intracellular protein interactions at nanometer spatial resolution in live cells using photoactivatable complementary fluorescent (PACF) proteins. The PACF approach established here will enable the simultaneous visualization of homo- and heterodimeric interactions at the single live-cell level.

Visualization of specific molecules and their interactions in real time and space is essential to delineate how cellular dynamics and the signaling circuit are orchestrated. Spatial regulation of conformational dynamics and structural plasticity of protein interactions is required to rewire signaling circuitry in response to extracellular cues. We introduce a method for optically imaging intracellular protein interactions at nanometer spatial resolution in live cells, using photoactivatable complementary fluorescent (PACF) proteins. Subsets of complementary fluorescent protein molecules were activated, localized, and then bleached; this was followed by the assembly of superresolution images from aggregate position of sum interactive molecules. Using PACF, we obtained precise localization of dynamic microtubule plus-end hub protein EB1 dimers and their distinct distributions at the leading edges and in the cell bodies of migrating cells. We further delineated the structure–function relationship of EB1 by generating EB1-PACF dimers (EB1^wt:EB1^wt, EB1^wt:EB1^mt, and EB1^mt:EB1^mt) and imaging their precise localizations in culture cells. Surprisingly, our analyses revealed critical role of a previously uncharacterized EB1 linker region in tracking microtubule plus ends in live cells. Thus PACF provides a unique approach to delineating spatial dynamics of homo- or heterodimerized proteins at the nanometer scale and establishes a platform to report the precise regulation of protein interactions in space and time in live cells.

Factors associated with incident HIV infection versus prevalent infection among youth in Rakai, Uganda

Factors associated with prevalent and incident HIV infection were compared among sexually experienced Ugandans aged 15–24. Most factors were similar. However, in women, older age and current marriage were associated with prevalent, but not incident, infection. It is important to recognize the limitations of prevalence analyses for identifying at-risk youth.

Self-adaptive image denoising based on bidimensional empirical mode decomposition (BEMD)

To better analyze images with the Gaussian white noise, it is necessary to remove the noise before image processing. In this paper, we propose a self-adaptive image denoising method based on bidimensional empirical mode decomposition (BEMD). Firstly, normal probability plot confirms that 2D-IMF of Gaussian white noise images decomposed by BEMD follow the normal distribution. Secondly, energy estimation equation of the ith 2D-IMF (i=2,3,4,......) is proposed referencing that of ith IMF (i=2,3,4,......) obtained by empirical mode decomposition (EMD). Thirdly, the self-adaptive threshold of each 2D-IMF is calculated. Eventually, the algorithm of the self-adaptive image denoising method based on BEMD is described. From the practical perspective, this is applied for denoising of the magnetic resonance images (MRI) of the brain. And the results show it has a better denoising performance compared with other methods.

Efficient inhibition of intraperitoneal human ovarian cancer growth by short hairpin RNA targeting CD44

CD44 is one member of a big glycoprotein family involved in adhesion of cells or cells and extracellular matrix (ECM). The heavily glycosylated CD44 has been proved to be a major receptor of hyaluronan and a marker of stem cells in ovarian cancer. Here, using short hairpin (shRNA) against CD44, we demonstrate that knockdown CD44 could inhibit cancer growth efficiently compared with controls. Plasmid targeting CD44 gene (pshCD44) or non-relative control sequences (pshHK) was constructed and delivered to ovarian cancer by biodegradable poly D, L-Lactide-co-glycolide acid nanoparticles (PLGANPs). Nude mice were utilized in an intraperitoneal model of ovarian carcinomatosis to assess antitumor efficacy in vivo. Antitumor efficacy was estimated by changes in tumor weights, proliferation (Ki-67), apoptosis (TUNEL) and angiogenesis (CD31 staining and alginate-encapsulated tumor beads assay) in tumor cells. As results, pshCD44 or pshHK could be effectively transfected into SKOV-3 cells by PLGANPs. Tumor weight in pshCD44/PLGANPs group was suppressed by 45% and 50% compared with those in pshHK/PLGANPs and untreated group, respectively (Ps < 0.001). Inhibition of cell proliferation, induction of apoptosis and reduction of angiogenesis in tumor cells of pshCD44/PLGANPs group also show significant difference compared with those in control groups (Ps < 0.05), respectively. These results indicate that pshCD44 delivered by PLGANPs might be a potential approach in ovarian cancer therapy, and point towards a mechanism involving the inhibition of angiogenesis, cellular proliferation and the induction of apoptosis.

Graphene optomechanics realized at microwave frequencies

Cavity optomechanics has served as a platform for studying the interaction between light and micromechanical motion via radiation pressure. Here we observe such phenomena with a graphene mechanical resonator coupled to an electromagnetic mode. We measure thermal motion and backaction cooling in a bilayer graphene resonator coupled to a microwave on-chip cavity. We detect the lowest flexural mode at 24 MHz down to 60 mK, corresponding to 50±6 mechanical quanta, which represents a phonon occupation that is nearly 3 orders of magnitude lower than that which has been recorded to date with graphene resonators.