Detection of Naturally occurring abortive transcripts by Base-Stacking Hybridization Assisted Ligation and PCR amplification.

Abortive transcripts (ATs) refer to nascent 2-10 nucleotides (nt) RNAs released by RNA polymerases before synthesizing productive RNAs. The quantitative detection of ATs is important for studying transcription initiation and the biological function of ATs; however, no method is available for the qualitative and quantitative assessment of such ultra-short oligonucleotides (typically shorter than 11 nt) in vivo at present, even with the LNA probes, the detection limit can only reach 11 nt. Here, we demonstrated the base stacking hybridization assisted ligation (BSHAL) technique, combined with TaqMan-MGB qPCR, can detect 4-10 nt ATs with a specificity of nucleotide resolution and a sensitivity of approximately 10 pM. By this technique, we detected endogenous ATs in cell lines, mice plasmas, and mice liver tissues, respectively, and proved that naturally occurring ATs do exist. We found that the 8 nt ATs of HMSB and Gapdh could be used as reference ATs for data normalization in Homo and mouse respectively, and 8 nt ATs of Afp and Gpc3 were suitable for use as plasma biomarkers of Hepatocellular carcinoma in mouse, indicate ATs are promising biomarkers. This study offers opportunities to study ATs and other ultra-short oligonucleotides in biological samples.

Monitoring of salicylic acid content in human saliva and its relationship with plasma concentrations.

Aspirin is a widely used anti-inflammatory drug. It is reported that a relationship may exist between salicylic acid content in plasma and saliva after taking aspirin. This study established a rapid, convenient, and safe method to assess salicylic acid concentration in human saliva. A novel HPLC-ultraviolet detector was used to measure salicylic acid concentrations in human saliva and plasma. A C18 reversed-phase column with an aqueous solution of 0.1% trifluoroacetic acid (TFA)-acetonitrile mobile phase was used, and drug peaks were recorded at 303 nm. Salicylic acid was completely separated in saliva and plasma. Excellent linearity and correlation (r2 ≥ 0.9999) was observed between 0.1 and 2.0 µg/mL. The detection limit (S/N = 3) was 33 ng/mL, and intra- and inter-day recoveries were 103.5-113.3% and 101.1-109.5%, respectively. Salicylic acid was measured within nine hours after administration of acetylsalicylic acid tablets. A positive correlation between salicylic acid content in saliva and plasma was found (r = 0.867, p < 0.001). The proposed method was used successfully to measure salicylic acid concentration in human saliva. Meanwhile, we explored the relationship between salicylic acid levels in plasma and saliva. Saliva might replace blood for monitoring aspirin treatment. In addition, the research provides a reference for application to saliva samples.

Energy-Efficient Data Collection Using Autonomous Underwater Glider: A Reinforcement Learning Formulation.

The autonomous underwater glider has attracted enormous interest for underwater activities, especially in long-term and large-scale underwater data collection. In this paper, we focus on the application of gliders gathering data from underwater sensor networks over underwater acoustic channels. However, this application suffers from a rapidly time-varying environment and limited energy. To optimize the performance of data collection and maximize the network lifetime, we propose a distributed, energy-efficient sensor scheduling algorithm based on the multi-armed bandit formulation. Besides, we design an indexable threshold policy to tradeoff between the data quality and the collection delay. Moreover, to reduce the computational complexity, we divide the proposed algorithm into off-line computation and on-line scheduling parts. Simulation results indicate that the proposed policy significantly improves the performance of the data collection and reduces the energy consumption. They prove the effectiveness of the threshold, which could reduce the collection delay by at least 10% while guaranteeing the data quality.

Family-based randomized trial to detect effects on blood pressure of a salt substitute containing potassium and calcium in hypertensive adolescents.

BACKGROUND: Potassium and calcium are important in blood pressure (BP) regulation. The aim of this study was to test the effects on BP of adding potassium and calcium to dietary salt. METHODS: A total of 325 adolescents selected with high BP (systolic BP (SBP) >or=90th percentile by age and sex) along with 978 family members. The adolescents were randomized into three groups by coin toss, and their families (300 total) were also allocated to the three groups: one in which 10 mmol of potassium and 10 mmol of calcium were added to the cooking salt, one encouraged to follow a salt-restricted diet, and a control group. In the salt-restricted group, salt intake was decreased gradually through health-behavior education to reach the goal of 50-100 mmol per person per day at 2 years. No intervention took place in for the control group. Salt sensitivity was determined by a volume expansion and contraction protocol at the beginning of the study. The three groups were followed up every 6 months for 2 years. RESULTS: At 2 years, systolic and diastolic blood pressure (SBP/DBP) had decreased by 5.9/2.8 mm Hg (4.7/3.6%) in the added-potassium-and-calcium group and by 5.8/1.0 mm Hg (4.8/1.4%) in the salt-restricted group; the values rose in the control group by 1.3/2.3 mm Hg (1.1/1.8%). There was no difference between the added-potassium-and-calcium group and the restricted-salt group (P = 0.24), but both differed significantly from the controls (P < 0.05). Similar changes in BP were found in family members. Subgroup analysis showed that the BP in salt-sensitive (SS) subjects decreased more than in the non-salt-sensitive (NSS) group (P < 0.05). CONCLUSION: A salt substitute containing potassium and calcium was as effective as sodium restriction in reducing BP in hypertensive adolescents and their families in a that rural Chinese community.

[Association between higher blood pressure level in children and adult blood pressure: 17 years follow-up results].

OBJECTIVE: Essential hypertension may begin at childhood. The aim of this study is to identify the risk factors of hypertension and detect the evolvement tracking of blood pressure in childhood. METHODS: In this study, we followed up blood pressure changes in 4623 school children (6 - 15 years-old) from 1987 to 2005 in Hanzhong rural area. A total of 152 children were grouped to higher blood pressure group [systolic blood pressure (P(SBP)) >or= 75(th) (P(75))] and 140 children grouped to normal blood pressure group [P(SBP) < 50(th) (P(50))] and their blood pressure were re-measure 18-years later. RESULTS: The total follow-up rate was 70.2%. Follow-up blood pressure was significantly higher in higher blood pressure group at baseline than that in normal blood pressure group at baseline (P < 0.05). The hypertension rate at follow up was significantly higher in higher blood pressure group at baseline than that in normal blood pressure group at baseline (28.0% vs. 4.1%, P < 0.01). The risk for hypertension was 6.88 greater in higher blood pressure group at baseline than that in normal blood pressure group at baseline. CONCLUSIONS: Higher blood pressure at childhood is a risk of developing hypertension at adulthood.

[Long term observation in effects of potassium and calcium supplementation on arterial blood pressure and sodium metabolism in adolescents with higher blood pressure].

OBJECTIVE: To investigate the effects of potassium and calcium supplementation in table salt on reduction of arterial blood pressure and sodium metabolism in adolescents with higher blood pressure. METHODS: A single blind placebo-controlled trial was carried out for two years in 220 adolescents with higher blood pressure, aged 18 - 22 years, who were randomly divided into supplementary group (n = 110) and control group (n = 110). Each of the subjects in the supplementary group and their family members was given 10 mmol of potassium and 10 mmol of calcium mixed in their table salt daily for 24 months. RESULTS: Night urinary sodium and potassium excretion increased (urinary Na(+), P < 0.05; urinary K(+), P < 0.01) and blood pressure lowered by 5.3 mm Hg/1.8 mm Hg in average from the baseline in the supplementary group two years after potassium and calcium supplementation, as compared with that in the control group increased by (1.3/1.7) mm Hg. CONCLUSIONS: Adequate supplement of potassium and calcium in daily table salt intake was an effective way to prevent form hypertension and could promote their urinary sodium excretion and reduction of arterial blood pressure in adolescents with higher blood pressure.