BACKGROUND Sexual and reproductive health among adolescents have become increasingly important and aroused international concerns. In this study, we investigate sexual knowledge, attitudes, sexual behaviors, the unwanted pregnancy and the abortion rate and to explore related determinants among college students in Beijing. METHODS This study is based on a cross-sectional survey of college students' knowledge, attitudes and behavior. Multistage cluster sampling was used to select subjects in Beijing. The self-questionnaire designed by our research group including general information, knowledge, attitude and behavior about sexuality was used to collect information. A total of 2003 questionnaires were collected from June to July 2010. RESULTS The data showed that most of the college students lacked knowledge about reproductive health. Only 17.9% of the respondents knew the appropriate time of abortion. Data also showed that the respondents had high-risk attitude about sex, 58.7% could accept premarital sex, and 29.7% had negative attitude towards contraception. Moreover, sexual activity of the respondents was active. Data showed that 18.5% of the respondents had had sexual activities. Significantly more boys than girls had sex (χ(2)= 73.374, P < 0.001). Among the boys and girls who reported sexual history, 43.1% of the boys had impregnated girlfriend and 49.3% of the girls among those people who have sex had unwanted pregnancies. Logistic regression analysis showed that the variables the gender (OR = 3.12, 95%CI: 2.39 - 4.11), grade (OR = 1.78, 95%CI: 1.40 - 2.26), specialty (OR = 1.35, 95%CI: 1.12 - 1.74), family situation (OR = 1.66, 95%CI: 1.15 - 2.38), score of knowledge (OR = 0.74, 95%CI: 0.58 - 0.95) and attitude to sex activity (OR = 0.09, 95%CI: 0.04 - 0.22) had a significant effect on having sexual behavior. CONCLUSIONS College students lack knowledge and methods to avoid risky sexual behaviors in Beijing. College students have high-risk sexual attitude and behaviors. Therefore, suitable and effective sex health measures to protect college students would be strongly recommended.

BACKGROUND Stenting strategies and clinical outcomes of bifurcation lesions in a chronic total occlusion (CTO) vessel after successful recanalization remain to be unknown. METHODS Between January 2001 and December 2009, 195 (41.1%) patients with 254 (47.0%) bifurcation lesions in CTO vessels from a pool of 564 patients with 659 CTO lesions were included and divided into proximal (n = 134) and distal (n = 120) groups, according to the location of the bifurcation lesions. The primary endpoint was the occurrence of major adverse cardiac events (MACE) at the end of clinical follow-up, including cardiac death, myocardial infarction, or target vessel revascularization (TVR). RESULTS Collaterals with Rentrop class 3 were seen more in distal group (100% and 68.3%), compared to proximal group (76.9% and 45.6%). Two-stent technique for proximal bifurcation lesions was used in 24.6%, significantly different from the distal group (6.7%, P < 0.001), without significant difference in composite MACE between proximal and distal groups, or between one- and two-stent subgroups in proximal group. The composite MACE after 1-year in complete revascularization subgroup was 17.9% relative to 29.6% in the incomplete revascularization group (P = 0.044). Stents in long false lumen in main vessel were mainly attributive to decreased TIMI grade flow, with resultant increased in-stent restenosis, total occlusion, TVR and coronary aneurysms. Imcomplete revasculzarization (HR 2.028, P = 0.049, 95%CI 1.002 - 4.105) and post-stenting TIMI flow (HR 6.122, P = 0.020, 95%CI 1.334 - 28.092) were two independent predictors of composite MACE at the 1-year follow-up. CONCLUSIONS Two-stent was more used for proximal bifurcation lesions. No significant difference was observed in MACE between proximal and distal, or between one- and two-stent subgroups in the proximal group. Placement of a safety wire was critical for proximal bifurcation lesions. Complete revascularization was mandatory to improve clinical outcomes.

Semiconducting polymers with low-density side-chain carboxylic acid groups were synthesized to form stable, functionalized, and highly fluorescent polymer dots (Pdots). The influence of the molar fraction of hydrophilic side-chains on Pdot properties and performance was systematically investigated. Our results show that the density of side-chain carboxylic acid groups significantly affects Pdot stability, internal structure, fluorescence brightness, and nonspecific binding in cellular labeling. Fluorescence spectroscopy, single-particle imaging, and a dye-doping method were employed to investigate the fluorescence brightness and the internal structure of the Pdots. The results of these experiments indicate that semiconducting polymers with low density of side-chain functional groups can form stable, compact, and highly bright Pdots as compared to those with high density of hydrophilic side-chains. The functionalized polymer dots were conjugated to streptavidin (SA) by carbodiimide-catalyzed coupling and the Pdot-SA probes effectively and specifically labeled the cancer cell-surface marker Her2 in human breast cancer cells. The carboxylate-functionalized polymer could also be covalently modified with small functional molecules to generate Pdot probes for click chemistry-based bioorthogonal labeling. This study presents a promising approach for further developing functional Pdot probes for biological applications.

BACKGROUND: IgA nephropathy (IgAN) is prevalent among both children and adults. Illumination of the differences between them is important for clinical doctors. METHODS: We retrospectively compared clinicopathological features in 110 children and 908 adults with IgAN. RESULTS: The male to female ratio was 1.62:1 in children and 0.85:1 in adults. Most patients lacked triggers, but IgAN was preceded by upper respiratory infection (URI) in 45.5% of children and 20.2% of adults. Gross hematuria was the most common initial symptom in children (53.6%), especially in those associated with URI (82.0%), while other symptoms and abnormal laboratory parameters were more common in adults. Estimated glomerular filtration rate (eGFR) was higher in children than in adults. Co-deposition of IgA and C3 were found in 50.9% of children, while IgA deposit was often accompanied by two or more immune complexes in adults. The frequency of subclass I was significantly higher in children than in adults. Mild histological lesions were more common in pediatric IgAN patients associated with URI than other patients. CONCLUSIONS: Pediatric patients showed relatively mild clinical manifestations and histological lesions compared with adult patients. URI was the most important trigger for IgAN, particularly in children. IgAN associated with URI was relatively mild.

Noninvasive photoacoustic microscopy was developed to image intracellular gold nanorods with high optical-absorption contrast. The endocytosed gold nanorods in MCF7 cells can be detected and imaged with the home-made photoacoustic microscope. Cell nucleus and gold nanorods in cytoplasm were clearly identified after hematoxylin and eosin (H&E) staining with dual-wavelength excitation. The intracellular gold nanorods were successfully monitored, and that the time-dependent uptake and distribution of the gold nanorods in the cells were clearly shown. The result demonstrated an application of photoacoustic microscopy for complements to imaging of nonfluorescent nanoparticles, which will arm the in vivo microscopic imaging method to the nano-bio research.

Few pharmacogenomic dosing regimens of warfarin have been developed for Chinese patients with non valvular atrial fibrillation (NVAF). The objective of this study was to develop a new algorithm by polymorphisms of CYP2C9 , VKORC1 and CYP4F2 to predict daily stable dose of warfarin in Chinese patients with NVAF. A total of 325 Chinese NVAF patients on stable dose of warfarin with a target international normalised ratio of 1.5 to 3.0 were recruited and divided randomly into two cohorts. CYP2C9 *3, VKORC1 -1639, VKORC1 1173 and CYP4F2 were detected by ligase detection reaction method. The new algorithm was developed with multivariate linear regression in cohort 1 (260 patients) and assessed with Pearson Correlation Analysis (PCA) in cohort 2 (65 patients). From 260 enrolled patients, the model (R2 = 51.7%) was developed as: Dose = 3.47 - 0.022 (AGE)+ 0.017 (WT)+ 0.189 (PTE)- 0.283 (β-blocker)- 0.471 (AMIO)- 0.586 ( CYP2C9 *1/*3)- 0.296 ( VKORC1 CT)- 0.648 ( VKORC1 TT)+ 0.219 ( CYP4F2 TT). PCA displayed that the algorithm was good (r = 0.658). The residual plots revealed that predicted dose by the algorithm tend to be overestimated when lower doses were administered to patients and be underestimated in higher doses. The algorithm developed by us might predict warfarin dose used by Chinese NVAF patients.

The effects of RNAi-mediated gene silencing of LRlG1 on proliferation and invasion of the human glioma cell line U251-MG and the possible mechanisms were explored in this study. The plasmids pGenesil2-LRIG1-shRNA1 and pGenesil2-LRIG1-shRNA2 were transfected into U251-MG glioma cells respectively by using Lipofectamine 2000 and the transfected cells in which the LRIG1 expression was stably suppressed were selected by G418. The cells transfected with negative shRNA served as control. The expression levels of LRIG1 mRNA and protein were measured by qRT-PCR and Western blotting, respectively. The cell cycle was analyzed by flow cytometry. The results showed that LRIG1 mRNA expression was reduced by 70% and 58% and LRIG1 protein expression by 58% and 26% in U251-MG cells transfected with pGenesil2-LRIG1-shRNAl and pGenesil2-LRIG1-shRNA2 relative to the negative shRNA-transfected U251-MG cells. The proliferative capacity of the LRIG1 specific siRNA-transfected cells was stronger than that of control cells. Cell cycle analysis showed that silencing LRIG1 significantly increased the percentage of S phase cells and the proliferation index (P<0.01). Moreover, silencing LRIG1 could promote the invasion of U251-MG cells (P<0.05). These findings suggested that LRIG1-targeting siRNA can exert a dramatically inhibitory effect on RNA transcription and protein expression of LRIG1, and LRIG1 down-regulation could promote the proliferation of U251-MG cells, arrest U251-MG cells in S phase, and enhance the invasion of U251-MG cells.

This communication describes a new class of semiconducting polymer nanoparticle-quantum dot hybrid with high brightness, narrow emission, near-infrared fluorescence, and excellent cellular targeting capability. Using this approach, we circumvented the current difficulty with obtaining narrow-band emission and near-infrared fluorescing semiconducting polymer nanoparticles, while combining the advantages of both semiconducting polymer nanoparticles and quantum dots. We further demonstrated the use of this new class of hybrid nanomaterial for effective and specific cellular and subcellular labeling without any noticeable nonspecific binding. This hybrid nanomaterial is anticipated to find use in a variety of in vitro and in vivo biological applications.

Malignant transformation of human prostatic epithelium is associated with loss of androgen receptor (AR) in the surrounding stroma. However, the function and mechanisms of AR signaling in prostate cancer (PCa) stroma remain elusive. Here we report that androgen and its receptor inhibit proliferation of prostate stromal cells through transcriptional suppression of cyclin B1 by Proteomics Pathway Array Analysis (PPAA), confirmed at mRNA and protein levels using AR negative or positive primary prostate stromal cells. Furthermore, AR showed a negative correlation with cyclin B1 expression in stroma of human PCa samples in vivo. Mechanistically, we identify cyclin B1 as a bona fide AR target gene in prostate stromal cells. The negative regulation of cyclin B1 by AR is mediated through switching between E2F1 and E2F4 on the promoter of cyclin B1. E2F1 binds to cyclin B1 promoter and maintains its expression and subsequent cell cycle progression in AR negative stromal cells or AR positive stromal cells when androgens are depleted. Upon stimulation with androgen in AR positive stromal cells, E2F1 is displaced from the binding site by AR and replaced with E2F4, leading to recruitment of the SMRT/HDAC3 co-repressor complex and repression of cyclin B1 at chromatin level. The switch between E2F1 and E2F4 at the E2F binding site of the cyclin B1 promoter coincides with an androgen-dependent interaction between AR and E2F1 as well as cytoplasmic to nuclear translocation of E2F4. Thus, we identified a novel mechanism for E2F factors in the regulation of cell cycle gene expression and cell cycle progression under the control of AR signaling.

The World Health Organization reported that inappropriate feeding in children is responsible for one-third of the cases of malnutrition. This cross-sectional study aimed to determine the prevalence of malnutrition and identify the relationship between feeding practices and malnutrition in children below 5 years, in 7 remote and poor counties of China. A sample of 2201 children and 1978 caregivers were obtained with multistage cluster random sampling. A survey about feeding practices among the caregivers was implemented using a structured questionnaire, and the health status of children was evaluated using anthropometric measurements. We found 5 problems: first, high prevalence of stunting, underweight and wasting in children below 5 years old (19.3%, 13.1% and 5.5%); second, short duration of breastfeeding for children below 36 months; third, low prevalence of exclusive breastfeeding among children below 6 months of age and continued breastfeeding to 1 year (17.5% and 32.2%). Fourth, although most of the infants (81.1%) between 6 and 8 months of age were given complementary foods, some of the 6- to 8-month-old infants did not receive any complementary foods. Last, a higher prevalence of stunting among Chinese children who had never been breastfed, who had been breastfed for less than 1 year, or had been fed with semi-solid foods of poor quality. Therefore, we suggest that more programs to increase caregivers' feeding knowledge and practices be conducted, to improve the health of children in remote and poor areas in China.