Chitosan/double-stranded RNA nanoparticle-mediated RNA interference to silence chitin synthase genes through larval feeding in the African malaria mosquito (Anopheles gambiae)

The purpose of this study was to examine whether the expression of two chitin synthase genes, AgCHS1 and AgCHS2, can be repressed by chitosan/AgCHS dsRNA-based nanoparticles through larval feeding in Anopheles gambiae. The AgCHS1 transcript level and chitin content were reduced by 62.8 and 33.8%, respectively, in the larvae fed on chitosan/AgCHS1 dsRNA nanoparticles compared with those of the control larvae fed on chitosan/GFP dsRNA nanoparticles. Our study suggested for the first time that RNA interference (RNAi) in mosquito larvae is systemic, and demonstrated that the larvae fed on the nanoparticles assembled from AgCHS1 and AgCHS2 dsRNA increased larval susceptibilities to diflubenzuron, and calcofluor white (CF) or dithiothreitol, respectively. These results suggest great potential for using such a nanoparticle-based RNAi technology for high-throughput screening of gene functions and for developing novel strategies for pest management.

Metabolic syndrome: prevalence and risk factors in southern China

This was a cross-sectional study to investigate the epidemiology of metabolic syndrome and the distribution of inter-related metabolic abnormalities in different population groups in Guangdong, southern China. Individuals were recruited according to the percentage of different occupational populations in southern China. The study cohort included 1206 subjects, and the prevalence and distribution of the components of metabolic syndrome were assessed using the National Cholesterol Education Program Adult Treatment Panel III 2005 criteria. The unadjusted rate of metabolic syndrome was 26.7%, and the prevalences of hypertension and diabetes were 38.0% and 4.3% respectively. Hypertension, diabetes, metabolic syndrome, abdominal obesity, elevated blood glucose and elevated blood pressure decreased significantly with increasing levels of life stress and anxiety. The prevalence of hypertension and metabolic syndrome in southern China is very high, and early identification and treatment of at-risk individuals may help target intervention to improve future cardiovascular health.

Search for new physics with a dijet plus missing E(T) signature in pp collisions at √s=1.96 TeV

We present results of a signature-based search for new physics using a dijet plus missing transverse energy (E(T)) data sample collected in 2  fb⁻¹ of pp collisions at √s=1.96  TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a nonstandard model process. The search is made by using novel, data-driven techniques for estimating backgrounds that are applicable to first searches at the LHC.

Signal transducer and activator of transcription 1 and matrix metalloproteinase 3 genetic expression and clinical significance on urothelial tumors after renal transplantation

OBJECTIVE

The objective of this study was investigate signal transducer and activator of transcription 1 and matrix metalloproteinase 3 genetic expression and clinical significance on urothelial carcinoma after renal transplantation.

METHODS

This study included 51 patients with histopathologically proven urothelial carcinoma, 16 of whom had undergone renal transplantation, and 35 others who had not and served as a control group. Human genome oligo-arrays were used to analyze the gene expression spectrum of the tumors. STAT1 and MMP3 expression in urothelial carcinoma was determined using real-time-polymerase chain reaction (RT-PCR) and immunohistochemistry staining. No prisoners or organs from prisoners were used in this study.

RESULTS

Among the transplantation group, 35 genes were up-regulated. The functions of 23 genes were known or partly known. Additionally, 76 genes were down-regulated in the transplantation group. The function of 46 genes was known or partly known. Pathway analysis of differences in gene expression between the groups revealed 23 groups of pathways that exhibited statistical significance (P < .05). The differences in the levels of expression of STAT1 and MMP3 were significant (P < .05).

CONCLUSIONS

Differences in gene expression profiles of STAT1 and MMP3 exist between patients who have and those who have not undergone renal transplantation. STAT1 and MMP3 may be potential targets for the chemoprevention of posttransplantation urothelial carcinoma.

Exclusion of an exotic top quark with -4/3 electric charge using soft lepton tagging

We present a measurement of the electric charge of the top quark using pp collisions corresponding to an integrated luminosity of 2.7 fb(-1) at the CDF II detector. We reconstruct tt events in the lepton + jets final state. We use soft lepton taggers to determine the flavor of the b jets, which we use to reconstruct the top quark's electric charge and exclude an exotic top quark with -4/3 charge at 95% confidence level. This is the strongest exclusion of the exotic charge scenario and the first to use soft leptons for this purpose.

Reduced birthweight in short or primiparous mothers: physiological or pathological?

OBJECTIVE

Customisation of birthweight-for-gestational-age standards for maternal characteristics assumes that variation in birth weight as a result of those characteristics is physiological, rather than pathological. Maternal height and parity are among the characteristics widely assumed to be physiological. Our objective was to test that assumption by using an association with perinatal mortality as evidence of a pathological effect.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

A total of 952 630 singletons born at > or =28 weeks of gestation in the period 1992-2001.

METHODS

We compared perinatal mortality among mothers of short stature (<160 cm) versus those of normal height (> or =160 cm), and primiparous versus multiparous mothers, using an internal reference of estimated fetal weight for gestational age. The total effects of maternal height and parity were estimated, as well as the effects of height and parity independent of birthweight (controlled direct effects). All analyses were based on fetuses at risk, using marginal structural Cox models for the estimation of total and controlled direct effects.

MAIN OUTCOME MEASURES

Perinatal mortality, stillbirth, and early neonatal mortality.

RESULTS

The estimated total effect (HR; 95% CI) of short stature on perinatal death among short mothers was 1.2 (95% CI 1.1-1.3) compared with women of normal height; the effect of short stature independent of birthweight (controlled direct effect) was 0.8 (95% CI 0.6-1.0) among small-for-gestational-age (SGA) births, but 1.1 (95% CI 1.0-1.3) among non-SGA births. Similar results were observed for primiparous mothers.

CONCLUSIONS

The effect of maternal short stature or primiparity on perinatal mortality is partly mediated through SGA birth. Thus, birthweight differences resulting from these maternal characteristics appear not only to be physiological, but also to have an important pathological component.

The effect of a high-fat meal on postprandial arterial stiffness in men with obesity and type 2 diabetes

CONTEXT

Postprandial dysmetabolism is emerging as an important cardiovascular risk factor. Augmentation index (AIx) is a measure of systemic arterial stiffness and independently predicts cardiovascular outcome.

OBJECTIVE

The objective of this study was to assess the effect of a standardized high-fat meal on metabolic parameters and AIx in 1) lean, 2) obese nondiabetic, and 3) subjects with type 2 diabetes mellitus (T2DM).

DESIGN AND SETTING

Male subjects (lean, n = 8; obese, n = 10; and T2DM, n = 10) were studied for 6 h after a high-fat meal and water control. Glucose, insulin, triglycerides, and AIx (radial applanation tonometry) were measured serially to determine the incremental area under the curve (iAUC).

RESULTS

AIx decreased in all three groups after a high-fat meal. A greater overall postprandial reduction in AIx was seen in lean and T2DM compared with obese subjects (iAUC, 2251 +/- 1204, 2764 +/- 1102, and 1187 +/- 429% . min, respectively; P < 0.05). The time to return to baseline AIx was significantly delayed in subjects with T2DM (297 +/- 68 min) compared with lean subjects (161 +/- 88 min; P < 0.05). There was a significant correlation between iAUC AIx and iAUC triglycerides (r = 0.50; P < 0.05).

CONCLUSIONS

Obesity is associated with an attenuated overall postprandial decrease in AIx. Subjects with T2DM have a preserved, but significantly prolonged, reduction in AIx after a high-fat meal. The correlation between AIx and triglycerides suggests that postprandial dysmetabolism may impact on vascular dynamics. The markedly different response observed in the obese subjects compared with those with T2DM was unexpected and warrants additional evaluation.