Clinical Efficacy and Safety of Acupressure on Low Back Pain: A Systematic Review and Meta-Analysis

OBJECTIVES

To evaluate the effectiveness and safety of acupressure on low back pain (LBP).

METHODS

We searched 7 electronic databases and 2 trial registries through December 28, 2020. Randomized controlled trials (RCTs) of acupressure on LBP were considered for meta-analysis with Revman 5.3 and Stata 15.0 software. Methodological quality was evaluated using the Cochrane Collaboration's tool. Trial sequential analysis (TSA) was used to quantify the statistical reliability. HETRED analysis and GRADE were used to determine the heterogeneity and quality of the results, respectively.

RESULTS

Twenty-three RCTs representing 2400 participants were included. Acupressure was superior to tuina massage on response rate (RR 1.25; 95% CI, 1.16 to 1.35; P < 0.00001) and in the standardized mean difference (SMD) for pain reduction [SMD -1.92; 95% CI, -3.09 to -0.76; P=0.001]. Likewise, acupressure was superior to physical therapy [SMD, -0.88; 95% CI, -1.10 to -0.65; P < 0.00001] and to usual care [SMD, -0.32; 95% CI, -0.61 to -0.02; P=0.04] in pain reduction. The Oswestry Disability Index was significantly improved by acupressure compared with usual care [SMD, -0.55; 95% CI, -0.84 to -0.25; P=0.0003]. The combination of acupressure with either manual acupuncture or electro-acupuncture showed significant improvements over the adjuvant therapies alone in response rate [RR 1.19; 95% CI, 1.13 to 1.26; P < 0.00001], pain reduction, and the Japanese Orthopedic Association score (JOA). However, each study displayed substantial heterogeneity. Through subgroup sensitivity analysis and -HETRED analysis, the heterogeneity of acupressure compared with manual acupuncture decreased while the results maintained significance with respect to pain reduction [SMD -0.9; 95% CI, -1.21 to -0.6; P < 0.00001] and JOA [SMD, 0.66; 95% CI, 0.33 to 0.98; P < 0.00001]. Similar results were obtained comparing acupressure with electro-acupuncture with respect to pain [SMD, -1.07; 95% CI, -1.33 to -0.81; P < 0.00001] and JOA [SMD, 0.89; 95% CI, 0.51 to 1.27, P < 0.00001]. TSA demonstrated the effectiveness of acupressure as a standalone or as a combinative treatment (with manual acupuncture or electro-acupuncture) for LBP.

CONCLUSION

Acupressure is an effective treatment for LBP. However, GRADE assessments downgraded the evidence in the trials, indicating that additional investigations are needed to confirm these observations.

A quantum dot fluorescent microsphere based immunochromatographic strip for detection of brucellosis

BACKGROUND

Brucellosis is a serious zoonosis disease that frequently causes significant economic loss in animal husbandry and threatens human health. Therefore, we established a rapid, accurate, simple and sensitive fluorescent immunochromatographic strip test (ICST) based on quantum dots (QDs) for detection the antibodies of Brucella infection animals serum.

RESULTS

The test strips were successfully prepared by quantum dot fluorescent microspheres (QDFM) as tracers, which were covalently coupled to an outer membrane protein of Brucella OMP22. The outer membrane protein OMP28 and monoclonal antibodies of OMP22 were separately dispensed onto a nitrocellulose membrane as test and quality control lines, respectively. The critical threshold for determining negative or positive through the ratio of the fluorescent signal of the test line and the control line (H_T / H_C) is 0.0492. The repeatability was excellent with an overall average CV of 8.78%. Under optimum conditions, the limit of detection was 1.05 ng/mL (1:512 dilution). With regard to the detection of brucellosis in 150 clinical samples, the total coincidence rate of ICST and Rose Bengal plate test (RBPT) was 97.3%, the coincidence rate of positive samples was 98.8%, the coincidence rate of negative samples was 95.3%, the sensitivity of RBPT is 1:32, and no cross reaction with the sera of other related diseases was observed.

CONCLUSION

In our present study, the QDFM has promising application for on-site screening of brucellosis owing to its high detection speed, high sensitivity, high specificity and low cost.

An overview on the veracity of intraoral digital scanning system and utilization of iTero scanner for analyzing orthodontic study models both In-Vivo and Ex-Vivo

In the domain of orthodontics, plaster models are contemplated as one of the important tools for diagnosis and treatment planning. In Dentistry, technological advancement has developed in the section of diagnostic devices, for example, the utilization of a 3D intraoral scanner, which can convert plaster models into digital models. With in-office utilization of this system, orthodontists can more meticulously and precisely construct custom braces, clear aligners, and orthodontic appliances. The digital data can be stored as a stereolithography file; it eliminates the disadvantages encountered with the storage of plaster models like breakage, space required, and distortion of the plaster models. ITero®element is the intraoral laser scanner (ILS) which utilizes parallel confocal scanning technology which maximizes the accuracy of the scan. By utilizing the iTero scanner, the dental measurement can be performed in OrthoCADTM software which is highly accurate. The objective of the contemporary study is to review the literature of studies on in-vivo and ex-vivo scanning with the iTero system.

Uric Acid Variability and All-Cause Mortality: A Prospective Cohort Study in Northern China

OBJECTIVES

Uric acid(UA) is related with cardiovascular disease, but the association of UA variability with all-cause mortality is rarely known. This study aimed to investigate the relationship between UA variability and all-cause mortality in Kailuan cohort study in northern China.

DESIGN

Cohort study.

SETTING

Kailuan community hospitals in Tangshan, Hebei province, Northern China.

PARTICIPANTS

A total of 55717 participants from Kailuan Study were enrolled, and our study followed up biennially from 2006 to 2010.

MEASUREMENTS

Clinical records of the participants enrolled were analyzed. UA variation independent of mean (UAVIM) values were calculated and all the participants were quartile grouped into four groups as: Q1(UAVIM<0.68), Q2(0.68≤UAVIM<1.10), Q3(1.10≤UAVIM<1.67) and Q4(UAVIM≥1.67). The endpoint event was all-cause death. Cox regression model was performed to evaluate the hazard ratios(HRs) of all-cause mortality based on UAVIM groups.

RESULTS

During a median follow-up of 6.83 years, 2926 deaths occurred. The accumulated mortality rates were 4.6%, 4.8%, 5.4% and 6.1% in group Q1, Q2, Q3 and Q4 respectively. When adjusted potential confounders, the highest risk for all-cause mortality was in group Q4 and the adjusted HRs and 95% confidence intervals(CIs) of group Q2-Q4 for all-cause death were 1.044(0.937, 1.164), 1.182(1.064, 1.314) and 1.353(1.220, 1.501) compared with group Q1, respectively. Further analysis showed that the risk for all-cause death increased as UAVIM value increased. Sensitive analysis still showed the similar results when excluding participants with hyperuricemia or severe chronic kidney diseases. Sub-group analysis by age, gender, BMI or hypertension history also indicated analogous results.

CONCLUSION

Elevated UAVIM was related with increased all-cause mortality and UAVIM was an independent risk factor for all-cause mortality in the community cohort study.

Validation of superior reference genes for qRT-PCR and Western blot analyses in marine Emiliania huxleyi-virus model system

AIMS

To search for a set of reference genes for reliable gene expression analysis in the globally important marine coccolithophore Emiliania huxleyi-virus model system.

METHODS AND RESULTS

Fifteen housekeeping genes (CDKA, CYP15, EFG3, POLAI, RPL30, RPL13, SAMS, COX1, GPB1-2, HSP90, TUA, TUB, UBA1, CAM3 and GAPDH) were evaluated for their stability as potential reference genes for qRT-PCR using ΔCt, geNorm, NormFinder, Bestkeeper and RefFinder software. CDKA, TUA and TUB genes were tested as loading controls for Western blot in the same sample panel. Additionally, target genes associated with cell apoptosis, that is metacaspase genes, were applied to validate the selection of reference genes. The analysis results demonstrated that putative housekeeping genes exhibited significant variations in both mRNA and protein content during virus infection. After a comprehensive analysis with all the algorithms, CDKA and GAPDH were recommended as the most stable reference genes for E huxleyi virus (EhV) infection treatments. For Western blot, significant variation was seen for TUA and TUB, whereas CDKA was stably expressed, consistent with the results of qRT-PCR.

CONCLUSIONS

CDKA and GAPDH are the best choice for gene and protein expression analysis than the other candidate reference genes under EhV infection conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

The stable internal control genes identified in this work will help to improve the accuracy and reliability of gene expression analysis and gain insight into complex E. huxleyi-EhV interaction regulatory networks.

Correção de fratura Salter-Harris tipo I em porquinho-da-índia (Cavia porcellus) ˗ relato de caso

RESUMO Um filhote de porquinho-da-índia (Cavia porcellus) foi recebido para atendimento após histórico de ataque por cão. Na avaliação física, observou-se edema, dor e crepitação em membro pélvico direito, sugestivo de fratura. Na avaliação radiográfica, confirmou-se fratura Salter-Harris tipo I em epífise distal da tíbia. A resolução cirúrgica escolhida foi a associação de pino transarticular e coaptação externa com tala de Altman. O paciente teve acompanhamento radiográfico semanal e obteve alta médica no 35o dia de pós-cirúrgico, quando se observou consolidação com completo remodelamento ósseo.

Effect of Liposome-Encapsulated Zoledronic Acid on Microenvironment of Hepatocellular Carcinoma May Depend on the Ratio Between M1 and M2 Polarized Macrophages

We studied the effect of zoledronic acid encapsulated into liposomes (L-ZOL) on tumorassociated macrophages in the stroma of hepatocellular carcinoma xenograft. Liposomes were prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-snglycero-3-phospho-sn-1-glycerol, and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethylene glycol)-2000] using thin film method and loaded with zoledronic acid. It was shown that L-ZOL promoted apoptosis of RAW264.7 cells, eliminate much more protumoral M2 macrophages than antitumoral M1 macrophages in the tumor xenograft, and did not significantly reduce the size of xenograft in 6 days. Thus, the effect of treatment depends on the ratio between antitumoral M1 and protumoral M2 polarized macrophages in the tumor.

MicroRNA-489 promotes cardiomyocyte apoptosis induced by myocardial ischemia-reperfusion injury through inhibiting SPIN1

OBJECTIVE

To investigate whether microRNA-489 could promote cardiomyocyte apoptosis through targeting inhibition of SPIN1, thus participating in the development of myocardial ischemia-reperfusion injury.

MATERIALS AND METHODS

MicroRNA-489 expression in H9c2 cells induced with hypoxia/reoxygenation (H/R) was determined by quantitative real-time polymerase chain reaction (qRT-PCR). With microRNA-489 overexpression in H/R H9c2 cells, activities of lactate dehydrogenase (LDH), methane dicarboxylic aldehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were detected using relative commercial kits, respectively. The regulatory effect of microRNA-489 on the proliferation and apoptosis of H/R H9c2 cells was assessed through cell counting kit-8 (CCK-8) assay and flow cytometry (FCM), respectively. Through conducting a dual-luciferase reporter gene assay, we evaluated the binding condition between microRNA-489 and SPIN1. Protein expressions of apoptotic genes in H/R H9c2 cells with microRNA-489 overexpression were determined by Western blot. Finally, the regulatory role of microRNA-489 in PI3K/AKT pathway was detected through Western blot.

RESULTS

QRT-PCR data showed that microRNA-489 was highly expressed in H/R H9c2 cells than those in normoxic control. Overexpression of microRNA-489 in H/R H9c2 cells increased the activities of LDH, MDA and GSH-PX, while decreased the activities of SOD. MicroRNA-489 overexpression markedly inhibited the proliferative rate but accelerated apoptosis of H/R H9c2 cells. Western blot results indicated that protein expressions of pro-apoptotic genes Bax and cytochrome C upregulated, whereas anti-apoptotic gene Bcl-2 downregulated after overexpression of microRNA-489 in H/R H9c2 cells. We confirmed that microRNA-489 could target to SPIN1 and inhibit its expression. After overexpression of microRNA-489 in H/R H9c2 cells, PI3K/AKT pathway was inhibited, which was further reversed by PI3K/AKT pathway agonist SC79. Besides, SC79 treatment also reversed the regulatory effect of overexpressed microRNA-489 on cellular behaviors of H/R H9c2 cells.

CONCLUSIONS

MicroRNA-489 inhibits the proliferation and accelerates apoptosis of cardiomyocytes after MIRI by targeting inhibition of SPIN1 via inactivating PI3K/AKT pathway. MicroRNA-489 may be a potential therapeutic target for MIRI.

Down-regulation of miR-155 promotes apoptosis of nasopharyngeal carcinoma CNE-1 cells by targeting PI3K/AKT-FOXO3a signaling

OBJECTIVE

Nasopharyngeal carcinoma is one of the common malignant tumors of the ear, nose, and throat in China. Cell apoptosis is expected to be closely related to prognosis. In recent years, with the development of non-coding RNA function research, it is proposed that miRNA plays an important role in the pathogenesis of nasopharyngeal carcinoma. This study aimed to investigate the role of miR-155 in the apoptosis of nasopharyngeal carcinoma cells.

PATIENTS AND METHODS

Cell transfection was performed to knockdown or overexpress the level of miR-155 or knockdown of the level of FOXO3a. The expression of the related protein was detected by immunoblotting. The Real Time quantitative-PCR was used to detect miR-155 expression. Cell proliferation was assessed by MTT assay. The changes of cell apoptosis were observed by flow cytometry using AV-PI staining and TUNEL staining.

RESULTS

The miR-155 inhibitor and mimics were successfully capable of knocking down or overexpressing miR-155 levels. After knocking down miR-155 level, cell proliferation was significantly attenuated, and apoptosis was significantly increased compared with the sham group (p < 0.05). After overexpression of miR-155, opposite results were observed. In addition, in the cells with the knockdown of miR-155 level, further knockdown of FOXO3a level significantly reduced the inhibitory effect of miR-155 on cell apoptosis compared with the control group (p < 0.05).

CONCLUSIONS

In nasopharyngeal carcinoma CNE-1 cell line, miR-155 can inhibit the proliferation and promote apoptosis of nasopharyngeal carcinoma cells by targeting PI3K/AKT-FOXO3a signaling. MiR-155 may be a novel target for the treatment of nasopharyngeal carcinoma.

Modeling Commodity Flow in the Context of Invasive Species Spread: Study of Tuta absoluta in Nepal

Trade and transport of goods is widely accepted as a primary pathway for the introduction and dispersal of invasive species. However, understanding commodity flows remains a challenge owing to its complex nature, unavailability of quality data, and lack of systematic modeling methods. A robust network-based approach is proposed to model seasonal flow of agricultural produce and examine its role in pest spread. It is applied to study the spread of Tuta absoluta, a devastating pest of tomato in Nepal. Further, the long-term establishment potential of the pest and its economic impact on the country are assessed. Our analysis indicates that regional trade plays an important role in the spread of T. absoluta. The economic impact of this invasion could range from USD 17-25 million. The proposed approach is generic and particularly suited for data-poor scenarios.

Genetically modified adipose-derived stem cells with matrix metalloproteinase 3 promote scarless cutaneous repair

Adipose-derived stem cells (ASCs) possess strong regenerative potencies and have been used to improve wound healing in animal models and clinical studies. However, the use of ASCs on scarless wound healing is not satisfactory. Matrix metalloproteinase 3 (MMP-3) is involved in extracellular matrix (ECM) remolding and scar formation. We aimed to investigate the effect of ASCs stable expressing MMP-3 (ASCs-MMP-3) on wound healing and scarring. A cutaneous wound healing animal model was used to assess the effect of ASCs and ASCs-MMP-3 on wound healing and scar formation. The target protein levels in the wound tissues were determined by western blot assay. Our results demonstrated that ASCs alone promoted wound healing but had a negligible effect on reducing scarring. ASCs-MMP-3 not only possessed the ability of ASCs to speed up wound healing, but also incorporated the capability of MMP-3 to reduce scaring. Overexpressing of MMP-3 decreased the collagen I, transforming growth factor (TGF)-β1, and α-smooth muscle actin (α-SMA) levels and enhanced collagen III and TGF-β3 levels which contributed to reducing scar formation. Our studies suggested that ASCs-MMP-3 is a potential candidate for developing effective therapeutic strategies for scarless wound healing.

[Application of Endo-GIA stapler in laparoscopic radicalcystectomy]

Objective: To explore the application of Endo-GIA stapler in laparoscopic radical cystectomy, especially in the treatment of lateral bladder ligament, and to evaluate its clinical feasibility and practicability. Methods: A retrospective analysis of clinical data about 38 cases of laparoscopic radical cystectomy (LRC) treated in the Department of Urology, Chaoyang Hospital of Beijing and Cancer Hospital, Chinese Academy of Medical Sciences from July 2017 to June 2019 were conducted. The patients were divided into Endo-GIA stopler group(18 cases) and non-Endo-GIA stopler group (20 cases) according to whether Endo-GIA stapler were used. The basic clinical data, operation time of bladder lateral ligament, operation time of bladder lateral wall, operation time of bladder resection, amount of bleeding during operation, pathological data after operation and related indicators of recovery after operation were compared between the two groups. Results: All 38 patients underwent radical cystectomy (RC) successfully under 3-D laparoscopy without conversion to open surgery. The operation time of bladder lateral ligament in Endo-GIA stapler group was significantly shorter than that in non-Endo-GIA stapler group [(3.25±0.75) min vs (9.20±2.95) min, P=0.042]; the operation time of bladder lateral wall in Endo-GIA stapler group was significantly shorter than that in non-Endo-GIA stapler group [(8.06±1.66) min vs (14.30±3.37) min, P=0.016]. The operation time of cystectomy in the Endo-GIA stapler group was significantly shorter than that in the non-Endo-GIA stapler group [(47.06±4.70) min vs (61.60±14.91) min,P=0.003]. The amount of bleeding in the Endo-GIA stapler group was significantly shorter than that in the non-Endo-GIA stapler group [(37.77±21.30) ml vs (114.50±39.80) ml, P=0.015]. The time of drainage tube removal in Endo-GIA group was significantly shorter than that in the non-Endo-GIA group [(5.83±1.54) d vs (7.30±3.00) d, P=0.002]. The length of post-hospitalization in Endo-GIA group was significantly shorter than that in the non-Endo-GIA group [(7.67±1.78) d vs (9.60±3.25) d,P=0.036]. However, there was no significant difference in other basic clinical data, post-operative pathology and post-operative recovery related indicators. Conclusions: Laparoscopic radical cystectomy using Endo-GIA stapler device is safe and feasible. It is easy to operate, shorten the operation time significantly, and reduce the amount of bleeding. To a certain extent, it is conducive to the recovery of patients after operation to some extent, and worthy of clinical application.

Nanographene oxides carrying antisense walR RNA regulates the Enterococcus faecalis biofilm formation and its susceptibility to chlorhexidine

Enterococcus faecalis is the dominant pathogen for persistent periapical periodontitis. The chlorhexidine (CHX) is used as conversional irrigation agents during endodontic root canal therapy. It was reported that the antisense walR RNA (ASwalR) suppressed the biofilm organization. The aim of this study was to investigate the antimicrobial effects of novel graphene oxide (GO)-polyethylenimine (PEI)-based antisense walR (ASwalR) on the inhibition of E. faecalis biofilm and its susceptibility to chlorhexidine. The recombinant ASwalR plasmids were modified with a gene encoding enhanced green fluorescent protein (ASwalR-eGFP) as a reporter gene so that the transformation efficiency could be evaluated by the fluorescence intensity. The GO-PEI-based ASwalR vector transformation strategy was developed to be transformed into E. faecalis and to over-produce ASwalR in biofilms. Colony forming units (CFU) and confocal laser scanning microscopy were used to investigate whether the antibacterial properties of antisense walR interference strategy sensitize E. faecalis biofilm to the CHX. The results indicated that overexpression of ASwalR by GO-PEI-based transformation strategy could inhibit biofilm formation, decrease the EPS synthesis and increase the susceptibility of E. faecalis biofilms to CHX. Our reports demonstrated that antisense walR RNA will be a supplementary strategy in treating E. faecalis with irrigation agents.

Direct-write 3D printing and characterization of a GelMA-based biomaterial for intracorporeal tissue

We develop and characterize a biomaterial formulation and robotic methods tailored for intracorporeal tissue engineering (TE) via direct-write (DW) 3D printing. Intracorporeal TE is defined as the biofabrication of 3D TE scaffolds inside of a living patient, in a minimally invasive manner. A biomaterial for intracorporeal TE requires to be 3D printable and crosslinkable via mechanisms that are safe to native tissues and feasible at physiological temperature (37 °C). The cell-laden biomaterial (bioink) preparation and bioprinting methods must support cell viability. Additionally, the biomaterial and bioprinting method must enable the spatially accurate intracorporeal 3D delivery of the biomaterial, and the biomaterial must adhere to or integrate into the native tissue. Current biomaterial formulations do not meet all the presumed intracorporeal DW TE requirements. We demonstrate that a specific formulation of gelatin methacryloyl (GelMA)/Laponite^®/methylcellulose (GLM) biomaterial system can be 3D printed at physiological temperature and crosslinked using visible light to construct 3D TE scaffolds with clinically relevant dimensions and consistent structures. Cell viability of 71%-77% and consistent mechanical properties over 21 d are reported. Rheological modifiers, Laponite^® and methylcellulose, extend the degradation time of the scaffolds. The DW modality enables the piercing of the soft tissue and over-extrusion of the biomaterial into the tissue, creating a novel interlocking mechanism with soft, hydrated native tissue mimics and animal muscle with a 3.5-4 fold increase in the biomaterial/tissue adhesion strength compared to printing on top of the tissue. The developed GLM biomaterial and robotic interlocking mechanism pave the way towards intracorporeal TE.

Transcriptional profiling of Pseudomonas aeruginosa PAO1 in response to anti-biofilm and anti-infection agent exopolysaccharide EPS273

AIMS

Relatively, few anti-biofilm polysaccharides against Pseudomonas aeruginosa were done to investigate the underlying molecular mechanism. Exopolysaccharide EPS273 can clearly reduce biofilm formation and infection of P. aeruginosa. This study aims to investigate its anti-biofilm and anti-infection mechanism on transcriptional level.

METHODS AND RESULTS

Herein, we used an RNA-Seq transcriptomic approach to investigate the underlying anti-biofilm and anti-infection mechanism of EPS273. The expression levels of a large number of genes were changed after P. aeruginosa PAO1 was treated with EPS273. Especially, the genes related to biofilm formation, such as gene involved in production of extracellular matrix and virulence factor, genes involved in flagella and cell motility and genes involved in iron acquisition. Notably, the expression levels of genes involved in regulatory and signal transduction were markedly downregulated, such as two-component system PhoP-PhoQ and quorum sensing (QS) system LasI/LasR and RhlI/RhlR. Furthermore, when genes phoP and phoQ were disrupted, respectively, the reduction of biofilm formation and cell motility in mutant △phoP or △phoQ was also detected.

CONCLUSION

EPS273 may exert its anti-biofilm and anti-infection function by downregulating gene expression of two-component system PhoP-PhoQ and QS systems LasI/LasR and RhlI/RhlR of P. aeruginosa, which further regulated expression of genes involved in biofilm formation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our data will expand understanding of anti-biofilm mechanisms of polysaccharides on transcriptomic level.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

[Feasibility of the determination of plasma vardenafil level in rat by performance liquid chromatography-tandem mass spectrometry]

Objective: To develope and validate a reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of vardenafil concentration in plasma of rat. Methods: Plasma samples of normal Sprague-Dawley rats were collected. A Phenomenex Synergi Polar-RP 80A column (2.0 mm×50 mm, 4 µm) was used. Column temperature was set at 30 ℃. Mobile phase A was 0.1% formic acid in water; mobile phase B was 0.1% formic acid in acetonitrile. The flow rate was 0.4 ml/minutes. Quantitative determination was performed by electrospray ionization, operating in positive ion multiple reaction monitoring (MRM) mode. Cisapride was used as the internal standard. The feasibility of the method was evaluated by examining its specificity, linearity and quantitative range, precision and accuracy, matrix effects, and stability. Results: Under the selected chromatographic and mass spectrometry conditions, the monitoring ions of vardenafil and internal standard were mass-to-charge ratio（m/z) 489.3/151.2 and 466.4/234.2, the retention times of vardenafil and internal standard were 2.62 and 2.80 minutes, respectively, and the peak shape was satisfactory. The method has good linearity in the concentration range of 0.2-200 ng/ml. The intra-batch precision (%CV) and accuracy (%DEV) of vardenafil were 1.5%-9.7% and -6.8%-6.6%, respectively. The inter-batch precision and accuracy of vardenafil were 3.1% -8.4% and -3.7%-4.6%, respectively. In this sample processing method, the extraction recovery rate of vardenafil was obtained at range of 88.2%-104.6%, which met the requirements for the investigation of extraction recovery rate. In this sample processing method, the normalized matrix factor of each quality control concentration of vardenafil was 1.04, 0.85, and 1.04, and the coefficient of variation (%CV) was in the range of 1.7%-10.7%, which met the requirements for the investigation of matrix effects. Variations of short-term stability, long-term stability, and stability of 4 freeze-thaw cycles of vardenafil was within ±15%, and the coefficient of variation were within 5%. Conclusion: The high performance liquid chromatography-tandem mass spectrometry method established in this study is feasible for the measurement of concentration of vardenafil in rat plasma and this method has good specificity and high accuracy, and can be used to detect the concentration of vardenafil in rat plasma.