A novel hollow CuMn-PBA@NiCo-LDH nanobox for efficient detection of glucose in food

Designing a rapid and sensitive glucose detection method is of great significance to public health. Herein, hollow CuMn-PBA@NiCo-LDH nanoboxes (CuMn-PBA@NiCo-LDH NBs) were prepared using acid etching, cation exchange, and reflux method. The modified electrode exhibited outstanding electrocatalytic performance for glucose oxidation due to the unique hollow nanostructure and synergistic effects. The CuMn-PBA@NiCo-LDH NBs electrode displayed excellent electrocatalytic oxidation activity for glucose in an alkaline solution. Under optimal conditions, the electrode achieved a wide linear range (0.0005-1 mmol L-1, and 1-7 mmol L-1) and high sensitivity (10,300 μA L/mmol cm-2 and 5310 μA L/mmol cm-2), with a limit of detection (LOD) of 19 nmol L-1. The feasibility of the sensor applied to the detection of glucose was verified in real food samples through spiked recovery experiments. This electrode material offers an alternative method for the non-enzymatic glucose sensors.

NiCo-LDH coupled with 2D ZIF-derived Co nitrogen doped carbon nanosheet arrays as a self-supporting electrocatalyst for detection of formaldehyde

Formaldehyde is susceptible to illegal addition to foodstuffs to extend their shelf life due to its antimicrobial, preservative and bleaching properties. In this study, a self-supporting "nanosheet on nanosheet" arrays electrocatalyst with core-shell heterostructure was prepared in situ by coupling NiCo layer double hydroxide with 2D ZIF derived Co-nitrogen-doped porous carbon on carbon cloth (Co-N/C@NiCo-LDH NSAs/CC). Co-N/C nanosheet arrays act as a scaffold core with good electrical conductivity, providing more NiCo-LDH nucleation sites to avoid NiCo-LDH agglomeration, thus having fast mass/charge transfer performance. While the NiCo-LDH nanosheet arrays shell with high specific surface area provide more active sites for electrochemical reactions. As an electrocatalytic sensing electrode, Co-N/C@NiCo-LDH NSAs/CC has a wide linear range of 1 μM to 13 mM for formaldehyde detection, and the detection limit is 82 nM. Besides, the sensor has been applied to the detection of formaldehyde in food samples with satisfactory results.

Construction of prediction model for fetal growth restriction during first trimester in an Asian population

OBJECTIVE

To construct a prediction model for fetal growth restriction (FGR) during the first trimester of pregnancy and evaluate its screening performance.

METHODS

This was a prospective cohort study of singleton pregnancies that underwent routine ultrasound screening at 11 to 13 + 6 weeks at the Affiliated Suzhou Hospital of Nanjing Medical University between January 2019 and April 2022. Basic clinical information, ultrasound indicators and serum biomarkers of pregnant women were collected. Fetal weight assessment was based on the fetal growth curve for the Southern Chinese population. FGR was diagnosed according to Delphi consensus criteria. Least absolute shrinkage and selection operator (lasso) regression was used to select variables for inclusion in the model. Discrimination, calibration and clinical effectiveness of the model were evaluated in training and validation cohorts.

RESULTS

A total of 1188 pregnant women were included, of whom 108 had FGR. Lasso regression identified seven predictive features, including history of maternal hypertension, maternal smoking or passive smoking, gravidity, uterine artery pulsatility index, ductus venosus pulsatility index and multiples of the median values of placental growth factor and soluble fms-like tyrosine kinase-1. The nomogram prediction model constructed from these seven variables accurately predicted FGR, and the area under the receiver-operating-characteristics curve in the validation cohort was 0.82 (95% CI, 0.74-0.90). The calibration curve and Hosmer-Lemeshow test demonstrated good calibration, and the clinical decision curve and clinical impact curve supported its practical value in a clinical setting.

CONCLUSION

The multi-index prediction model for FGR has good predictive value during the first trimester. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

One-step rapid synthesis of Ni0.5Co0.5-CPO-27 nanorod array with oxygen vacancies based on DBD microplasma: As an effective non-enzymatic glucose sensor for beverage and human serum

The rational design of high-efficiency catalysts for non-enzymatic glucose sensing is extremely important for the timely and effective monitoring of glucose content in beverages and human blood. A 3D bimetallic organic framework (Coordination Polymer of Oslo, CPO) nanorod array with oxygen vacancies was green fabricated on carbon cloth (Ni_0.5Co_0.5-CPO-27 NRA/CC) using dielectric barrier discharge (DBD) microplasma for the first time. Density functional theory (DFT) calculations demonstrated that the oxygen vacancy of Ni_0.5Co_0.5-CPO-27 can be effectively induced under DBD microplasma conditions. Based on the 3D nanorod arrays with rich oxygen vacancies and bimetallic synergistic effects, as a non-enzyme glucose sensor, the Ni_0.5Co_0.5-CPO-27 electrode exhibited a sensitivity of 8499.5 μA L/mmol cm^-2 and 3239.2 μA L/mmol cm^-2 and a limit of detection (LOD) of 0.16 μmol/L (S/N = 3). It has been successfully applied to the determination of glucose levels in real samples such as cola, green tea and human serum.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Is location of urethral kinking a confounder of association between urethral closure pressure and stress urinary incontinence?

OBJECTIVES

Intact urethral support and normal sphincter function are deemed important for urinary continence. We aimed to test whether the location of urethral kinking (as the probable anatomical correlate of maximal pressure transmission) is associated with stress urinary incontinence and/or urodynamic stress incontinence.

METHODS

This was a retrospective study of women seen at a tertiary urogynecological center in 2017. Patients had undergone an interview, multichannel urodynamic testing and four-dimensional translabial ultrasound examination. Those with a history of anti-incontinence surgery, absence of urethral kinking on ultrasound and/or missing or inadequate ultrasound volume data were excluded. Volume data were used to assess urethral mobility using a semi-automated Excel® urethral motion profile program. Mobility vectors were calculated using the formula √((x _valsalva  - x _rest )² + (y _valsalva  - y _rest )² ), where x and y are the coordinates of six equidistant points along the length of the urethra from the bladder neck to the external urethral meatus. The location of urethral kinking was identified as a concave contour of the urethra on the vaginal side in the midsagittal plane on maximum Valsalva maneuver. The distance between the center of the kink and the bladder neck was measured and expressed as a centile in relation to the total length of the urethra, using the formula: (distance from bladder neck/total length of urethra) × 100. Univariate and multivariate analyses were performed to test the associations of stress urinary incontinence and urodynamic stress incontinence with age, maximum urethral pressure, urethral mobility vectors and location of urethral kinking.

RESULTS

Of 450 women seen during the study period, 61 were excluded owing to previous incontinence surgery and 82 owing to absence of urethral kinking, inadequate volume data or missing data, leaving 307 women included, of whom 227 (74%) complained of stress urinary incontinence and 211 (69%) complained of urgency urinary incontinence. 190 (62%) of the women were diagnosed with urodynamic stress incontinence. On multivariate analysis, maximum urethral pressure (36 vs 50 cmH₂ O; P < 0.001), mid-urethral mobility (2.27 vs 2.03 cm; P = 0.003) and location of urethral kinking (63.1^st vs 59.7^th centile; P = 0.002) were associated significantly with urodynamic stress incontinence. The location of urethral kinking was associated with stress urinary incontinence on univariate analysis (P = 0.026) but not on multivariate analysis (P = 0.21).

CONCLUSIONS

The location of urethral kinking is associated with urodynamic stress incontinence. The further urethral kinking is from the mid urethra, the more likely is urodynamic stress incontinence. This provides circumstantial evidence for the pressure-transmission theory of stress urinary continence. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Epigenetic regulation of insulin action and secretion - role in the pathogenesis of type 2 diabetes

The prevalence of type 2 diabetes (T2D) is rapidly increasing worldwide. Obesity, physical inactivity and ageing increase the risk of T2D. Epigenetic modifications can change due to environmental exposures and may thereby predispose to disease. This review aims at summarizing recent advances in epigenetics related to T2D, with a special focus on impaired insulin action and secretion in humans. There will be an emphasis on analyses in human tissues; both from T2D case-control cohorts and intervention studies. Current data support an important role for epigenetics in the pathogenesis of T2D. Numerous studies have found differential DNA methylation and gene expression in skeletal muscle, adipose tissue, the liver and pancreatic islets from subjects with T2D compared with nondiabetic controls. For example, PDX1 has increased DNA methylation and decreased expression in pancreatic islets from patients with T2D compared with nondiabetic controls. Nongenetic risk factors for T2D such as ageing, unhealthy diets and physical activity do also impact the epigenome in human tissues. Interestingly, physical activity altered DNA methylation of candidate genes for T2D such as THADA in muscle and FTO, KCNQ1 and TCF7L2 in adipose tissue. There is also a strong interaction between genetic and epigenetic factors that together seem to affect T2D. mQTL studies in human adipose tissue and pancreatic islets showed that SNPs associated with DNA methylation levels in numerous sites. Several of these SNPs are also associated with T2D. Recent data also support that DNA methylation of some sites in blood may be developed into biomarkers that predict T2D since methylation of, for example TXNIP, ABCG1 and SREBF1 associated with future T2D. Future studies should use this information for development of new therapies and biomarkers and thereby improve prediction, prevention and treatment of T2D and its complications.

Brachybacterium nesterenkovii isolated from a human blood culture-a first report

Brachybacterium is a genus of Gram-positive bacteria that rarely causes infections in humans. Here we report the case of an 8-month-old infant who presented with an acute febrile illness. During the diagnostic process, a blood culture was positive with Gram-positive cocci that were identified as Brachybacterium nesterenkovii by MALDI-TOF. As a result of the unclear clinical significance of this isolate and the continuous febrile state, a second blood culture was taken and returned B. nesterenkovii once more. To our knowledge this is the first time that B. nesterenkovii has been isolated from human blood cultures during the course of a systemic infection.

[Study on purification effect of formaldehyde in cleanroom by new return air device]

Objective: To effectively reduce the concentration of poisons in cleanroom, protect the health of workers, realize the optimization and automatic control of the new return air device. And the influence of initial concentration, air volume, temperature and relative humidity of formaldehyde on the purification effect of the new return air device was explored. Methods: The purification effect of the new return air device installed with the activated carbon and the photocatalyst purification net or ordinary activated carbon purification network was tested in a 60 m(3) simulated cleanroom. The concentration of formaldehyde was determined by solution absorption-phenol reagent spectrophotometry. Based on the single factor experiment to determine the combination of two purification nets. The effects of air volume, initial formaldehyde concentration, temperature and relative humidity on the purification effect of the new return air device were investigated by orthogonal test. Then, the performance parameters of the return air device to purify formaldehyde were determined. Results: The formaldehyde purification efficiency of the two types of purification nets in the new return air device was higher than that of the ordinary activated carbon purification network (P<0.05) . The combination of activated carbon and photocatalyst purification net has no effect on the formaldehyde purification efficiency of the return air device (P>0.05) . According to the direct analysis and variance analysis, air volume was the most sensitive factor (F value is 18.894, P<0.05) , followed by initial concentration (F value is 16.128, P<0.05) , while temperature and relative humidity have little effect (F value is 0.041 and 0.599, respectively, P>0.05) . LSD analysis showed that there was no significant difference in the purification efficiency of formaldehyde between 475 m(3)/h and 626 m(3)/h (P>0.05) . From the perspective of formaldehyde purification efficiency and energy saving, when the air volume is set to 475 m(3)/h, the new return air device has higher purification efficiency for high concentration of formaldehyde. Conclusion: The new return air device consisting of activated carbon and photocatalyst purification net can play a good purification role in cleanroom with different temperatures and different humidity. Its formaldehyde purification efficiency is affected by air volume and initial concentration.

Triptolide induces mitochondrial apoptosis through modulating dual specificity phosphatase 1/mitogen-activated protein kinases cascade in osteosarcoma cells

Due to chemoresistance and metastasis, the overall prognosis of osteosarcoma (OS) has not improved over the last two decades. Exploring novel therapeutic agents that can circumvent theses malignant phenotypes of OS would be essential to improve the survival of OS patients. Triptolide is a unique diterpene triepoxide that possesses potent antitumor activities.However, the effects and mechanism of triptolide on OS cells remain unknown. The effects of triptolide on viability, apoptosis, cell cycle distribution and migratory ability of OS cells were measured using MTT, flow cytometry and wound healing and transwell invasion assays. And an OS tumor xenograft mouse model was produced to further study the in vivo antitumor effects of triptolide. The expression of DUSP1 at the protein and mRNA level in OS cells was detected by western blot and qPCR. We report that triptolide exhibits multidimensional antitumor activities in OS cells, including the induction of apoptosis and G1 phase accumulation, inhibition of cell viability, migration, and invasion. We further demonstrate that triptolide inhibits the expression of dual-specificity protein phosphatase1 (DUSP1) through inhibiting its promoter activity, which causes sustained activation of three subfamilies of mitogen-activated protein kinase (MAPK). And the modulation of DUSP1/MAPK cascade is associated with the apoptosis of OS cells, since the ectopic expression of DUSP1 or the inhibition of MAPK using specific inhibitors can counteract triptolide-induced apoptosis. In addition, triptolide enhances doxorubicin-induced apoptosis. In summary, our study suggests that DUSP1 is an important cellular target of triptolide, and triptolide may be a promising treatment option for OS as a single agent or combined with other chemotherapeutics.

Column-integrated aerosol optical properties of coarse- and fine-mode particles over the Pearl River Delta region in China

The sun-photometer data from 2011 to 2013 at Panyu site (Panyu) and from 2007 to 2013 at Dongguan site (Dg) in the Pearl River Delta region, were used for the retrieving of the aerosol optical depth (AOD), single scattering albedo (SSA), Ångström exponent (AE) and volume size distribution of coarse- and fine-mode particles. The coarse-mode particles presented low AOD (ranging from 0.05±0.03 to 0.08±0.05) but a strong absorption property (SSA ranged from 0.70±0.03 to 0.90±0.02) for the wavelengths between 440 and 1020nm. However, these coarse particles accounted for <10% of the total particles. The AOD of fine particles (AODf) was over 3 times as large as that of coarse particles (AODc). The fine particles SSA (SSAf) generally decreased as a function of wavelength, and the relatively lower SSAf value in summer was likely to be due to the stronger solar radiation and higher temperature. More than 70% of the aerosols at Panyu site were dominated by fine-mode absorbing particles, whereas about 70% of the particles at Dg site were attributed to fine-mode scattering particles. The differences of the aerosol optical properties between the two sites are likely associated with local emissions of the light-absorbing carbonaceous aerosols and the scattering aerosols (e.g., sulfate and nitrate particles) caused by the gas-phase oxidation of gaseous precursors (e.g., SO₂ and NO₂). The size distribution exhibited bimodal structures in which the accumulation mode was predominant. The fine-mode volume showed positive dependence on AOD (500nm), and the growth of peak value of the fine-mode volume was higher than that of the coarse volume. Both the AOD and SSA increased with increasing relative humidity (RH), while the AE decreased with increasing RH. These correlations imply that the aerosol properties are greatly modified by condensation growth.

3D Pseudocontinuous Arterial Spin-Labeling MR Imaging in the Preoperative Evaluation of Gliomas

BACKGROUND AND PURPOSE

Previous studies showed conflicting results concerning the value of CBF maps obtained from arterial spin-labeling MR imaging in grading gliomas. This study was performed to investigate the effectiveness of CBF maps derived from 3D pseudocontinuous arterial spin-labeling in preoperatively assessing the grade, cellular proliferation, and prognosis of gliomas.

MATERIALS AND METHODS

Fifty-eight patients with pathologically confirmed gliomas underwent preoperative 3D pseudocontinuous arterial spin-labeling. The receiver operating characteristic curves for parameters to distinguish high-grade gliomas from low-grade gliomas were generated. Pearson correlation analysis was used to assess the correlation among parameters. Survival analysis was conducted with Cox regression.

RESULTS

Both maximum CBF and maximum relative CBF were significantly higher in high-grade gliomas than in low-grade gliomas (P < .001). The areas under the curve for maximum CBF and maximum relative CBF in distinguishing high-grade gliomas from low-grade gliomas were 0.828 and 0.863, respectively. Both maximum CBF and maximum relative CBF had no correlation with the Ki-67 index in all subjects and had a moderate negative correlation with the Ki-67 index in glioblastomas (r = -0.475, -0.534, respectively). After adjustment for age, a higher maximum CBF (P = .008) and higher maximum relative CBF (P = .005) were associated with worse progression-free survival in gliomas, while a higher maximum relative CBF (P = .033) was associated with better overall survival in glioblastomas.

CONCLUSIONS

3D pseudocontinuous arterial spin-labeling-derived CBF maps are effective in preoperative evaluation of gliomas. Although gliomas with a higher blood flow are more malignant, glioblastomas with a lower blood flow are likely to be more aggressive.

Fabrication and characterization of gels with integrated channels using 3D printing with microfluidic nozzle for tissue engineering applications

The lack of a simple and effective method to integrate vascular network with engineered scaffolds and tissue constructs remains one of the biggest challenges in true 3D tissue engineering. Here, we detail the use of a commercially available, low-cost, open-source 3D printer modified with a microfluidic print-head in order to develop a method for the generation of instantly perfusable vascular network integrated with gel scaffolds seeded with cells. The print-head features an integrated coaxial nozzle that allows the fabrication of hollow, calcium-polymerized alginate tubes that can be easily patterned using 3D printing techniques. The diameter of the hollow channel can be precisely controlled and varied between 500 μm - 2 mm by changing applied flow rates or print-head speed. These channels are integrated into gel layers with a thickness of 800 μm - 2.5 mm. The structural rigidity of these constructs allows the fabrication of multi-layered structures without causing the collapse of hollow channels in lower layers. The 3D printing method was fully characterized at a range of operating speeds (0-40 m/min) and corresponding flow rates (1-30 mL/min) were identified to produce precise definition. This microfluidic design also allows the incorporation of a wide range of scaffold materials as well as biological constituents such as cells, growth factors, and ECM material. Media perfusion of the channels causes a significant viability increase in the bulk of cell-laden structures over the long-term. With this setup, gel constructs with embedded arrays of hollow channels can be created and used as a potential substitute for blood vessel networks.

Quantitative candidate gene association studies of metabolic traits in Han Chinese type 2 diabetes patients

Recent genome-wide association studies have identified many loci associated with type 2 diabetes mellitus (T2DM), hyperuricemia, and obesity in various ethnic populations. However, quantitative traits have been less well investigated in Han Chinese T2DM populations. We investigated the association between candidate gene single nucleotide polymorphisms (SNPs) and metabolic syndrome-related quantitative traits in Han Chinese T2DM subjects. Unrelated Han Chinese T2DM patients (1975) were recruited. Eighty-six SNPs were genotyped and tested for association with quantitative traits including lipid profiles, blood pressure, body mass index (BMI), serum uric acid (SUA), glycated hemoglobin (HbA1c), plasma glucose [fasting plasma glucose (FPG)], plasma glucose 120 min post-OGTT (P2PG; OGTT = oral glucose tolerance test), and insulin resistance-related traits. We found that CAMTA1, ABI2, VHL, KAT2B, PKHD1, ESR1, TOX, SLC30A8, SFI1, and MYH9 polymorphisms were associated with HbA1c, FPG, and/or P2PG; GCK, HHEX, TCF7L2, KCNQ1, and TBX5 polymorphisms were associated with insulin resistance-related traits; ABCG2, SLC2A9, and PKHD1 polymorphisms were associated with SUA; CAMTA1, VHL, KAT2B, PON1, NUB1, SLITRK5, SMAD3, FTO, FANCA, and PCSK2 polymorphisms were associated with blood lipid traits; CAMTA1, SPAG16, TOX, KCNQ1, ACACB, and MYH9 polymorphisms were associated with blood pressure; and UBE2E3, SPAG16, SLC2A9, CDKAL1, CDKN2A/B, TCF7L2, SMAD3, and PNPLA3 polymorphisms were associated with BMI (all P values <0.05). Some of the candidate genes were associated with metabolic and anthropometric traits in T2DM in Han Chinese. Although none of these associations reached genome-wide significance (P < 5 x 10(-8)), genes and loci identified in this study are worthy of further replication and investigation.

Han Chinese patients with dopa-responsive dystonia exhibit a low frequency of exonic deletion in the GCH1 gene

We identified three novel mutations of the GTP cyclohydrolase 1 (GCH1) gene in patients with familial dopa-responsive dystonia (DRD), but were unable to identify meaningful sporadic mutations in patients with no obvious family DRD background. To investigate whether GCH1 regional deletions account for the etiology of DRD, we screened for heterozygous exonic deletions in DRD families and in patients with sporadic DRD. Multiple ligation-dependent probe amplification analysis and quantitative real-time polymerase chain reaction amplification was performed in all members of our DRD cohort and in controls to detect exonic deletions in GCH1, tyrosine hydroxylase, and the epsilon-sarcoglycan-encoding (SGCE) genes. Using these techniques, we detected a GCH1 exon 1 heterozygous deletion in 1 of 10 patients with sporadic DRD. Therefore, we concluded that exonic deletion in the GCH1 gene only accounted for the etiology in a small percentage of patients with sporadic DRD in our Han Chinese cohort.

Less pronounced response to exercise in healthy relatives to type 2 diabetic subjects compared with controls

Healthy first-degree relatives with heredity of type 2 diabetes (FH+) are known to have metabolic inflexibility compared with subjects without heredity for diabetes (FH-). In this study, we aimed to test the hypothesis that FH+ individuals have an impaired response to exercise compared with FH-. Sixteen FH+ and 19 FH- insulin-sensitive men similar in age, peak oxygen consumption (V̇o2 peak), and body mass index completed an exercise intervention with heart rate monitored during exercise for 7 mo. Before and after the exercise intervention, the participants underwent a physical examination and tests for glucose tolerance and exercise capacity, and muscle biopsies were taken for expression analysis. The participants attended, on average, 39 training sessions during the intervention and spent 18.8 MJ on exercise. V̇o2 peak/kg increased by 14%, and the participants lost 1.2 kg of weight and 3 cm waist circumference. Given that the FH+ group expended 61% more energy during the intervention, we used regression analysis to analyze the response in the FH+ and FH- groups separately. Exercise volume had a significant effect on V̇o2 peak, weight, and waist circumference in the FH- group, but not in the FH+ group. After exercise, expression of genes involved in metabolism, oxidative phosphorylation, and cellular respiration increased more in the FH- compared with the FH+ group. This suggests that healthy, insulin-sensitive FH+ and FH- participants with similar age, V̇o2 peak, and body mass index may respond differently to an exercise intervention. The FH+ background might limit muscle adaptation to exercise, which may contribute to the increased susceptibility to type 2 diabetes in FH+ individuals.

MYH9 gene polymorphisms may be associated with cerebrovascular blood flow in patients with type 2 diabetes

Genetic factors play an important role in type 2 diabetes (T2D) complications. Alteration of cerebrovascular blood flow (CBF) is a direct result of cerebrovascular diseases. However, few studies have reported the role of genetics on CBF in patients with T2D. We investigated whether single-nucleotide polymorphisms (SNPs) in metabolic disease genes are associated with CBF in patients with T2D. CBF velocities of CBF were measured in 337 Han Chinese patients with T2D using transcranial Doppler sonography, with 54 cerebrovascular blood flow parameters documented. Fifty-two SNPs from 31 metabolic disease candidate genes were genotyped in patients. Quantitative allelic association and haplotype analyses were performed for candidate gene SNPs and CBF phenotypes. Spearman correlation was used to determine the relationship between CBF parameters and basic clinical characteristics, particularly, body mass index, lipids, fibrinogen, and GHbA1c. MYH9 gene SNPs (rs875726 and rs735853) may be associated with the peak velocity of the right-middle cerebral artery. SNPs rs875726, rs2009930, and rs375246 of the MYH9 gene may be associated with the mean velocity of the right-anterior and posterior cerebral artery. The haplotype G-C-A (rs2239782-rs3752462- rs2269532) of MYH9 may be associated with CBF. MYH9 gene polymorphisms may be associated with multiple CBF phenotypes in Chinese patients with T2D. However, whether MYH9 is a candidate gene for cerebrovascular diseases in Chinese patients with T2D remains unknown.

Extensive changes in the transcriptional profile of human adipose tissue including genes involved in oxidative phosphorylation after a 6-month exercise intervention

AIM

Adipose tissue has an important function in total energy homeostasis, and its dysregulation may contribute to lifestyle-related diseases such as type 2 diabetes, cancer and cardiovascular diseases. The aim of this study was to investigate genome-wide mRNA expression in adipose tissue in healthy men before and after an exercise intervention to identify genes or pathways that mediate the beneficial effect of regular exercise. We also investigated the difference in adipose tissue mRNA expression between individuals with or without a family history of type 2 diabetes.

METHODS

The 6-month supervised exercise intervention was conducted in 47 healthy men (age 37.8 ± 4.3 years, BMI 28.5 ± 3.6 kg m(-2) ) with a previous low level of physical activity. RNA was analysed using GeneChip Human Gene 1.0 ST arrays (Affymetrix) before and after the exercise.

RESULTS

We identified 2,560 significant transcripts differentially expressed before vs. after exercise with a false discovery rate (FDR) < 0.1%, including genes encoding the respiratory chain, histone subunits, small nucleolar RNAs and ribosomal proteins. Additionally, pathways enriched in response to exercise include the ribosome, oxidative phosphorylation, proteasome and many metabolic pathways, whereas the WNT and MAPK signalling pathways were down-regulated (FDR < 5%) after exercise. There were no significant differences in mRNA expression between individuals with or without a family history of type 2 diabetes.

CONCLUSION

Exercise increased the expression of genes involved in oxidative phosphorylation, which is the opposite of what has been seen in adipose tissue from elderly or obese individuals with low physical fitness, and our study thereby demonstrates a mechanism for the beneficial effect of exercise.

A novel splicing site mutation of the GPR143 gene in a Chinese X-linked ocular albinism pedigree

Ocular albinism is an X-linked inherited disease characterized by hypopigmentation of the iris and nystagmus. To identify a new disease-causing mutation of ocular albinism, we collected a Han Chinese pedigree with 7 male congenital nystagmus patients over 3 generations. Slit-lamp photography and optical coherence tomography were performed for the proband. Genomic DNA was extracted from a whole blood sample from the proband using the high-salt method. Polymerase chain reaction (PCR) sequencing was carried out for GPR143 and FRMD7 genes. The three-dimensional structures of the wild-type and mutant GPR143 proteins were determined using SWISS-MODEL. The transmission of the disease in the pedigree clearly followed an X-linked pattern. The proband had significant iris and fundus hypopigmentation. Optical coherence tomography showed severe foveal hypoplasias in both eyes of the proband. A novel splicing site (G/C) mutation was found on the boundary of the 6th intron and the 7th exon of the GPR143 gene, resulting in a 9-amino-acid deletion (codons 257-265) in the 6th transmembrane domain of the GPR143 protein. In conclusion, a novel splicing site mutation of the GPR143 gene was found in a Han Chinese congenital ocular albinism pedigree.

Identification of CpG-SNPs associated with type 2 diabetes and differential DNA methylation in human pancreatic islets

AIMS/HYPOTHESIS

To date, the molecular function of most of the reported type 2 diabetes-associated loci remains unknown. The introduction or removal of cytosine-phosphate-guanine (CpG) dinucleotides, which are possible sites of DNA methylation, has been suggested as a potential mechanism through which single-nucleotide polymorphisms (SNPs) can affect gene function via epigenetics. The aim of this study was to examine if any of 40 SNPs previously associated with type 2 diabetes introduce or remove a CpG site and if these CpG-SNPs are associated with differential DNA methylation in pancreatic islets of 84 human donors.

METHODS

DNA methylation was analysed using pyrosequencing.

RESULTS

We found that 19 of 40 (48%) type 2 diabetes-associated SNPs introduce or remove a CpG site. Successful DNA methylation data were generated for 16 of these 19 CpG-SNP loci, representing the candidate genes TCF7L2, KCNQ1, PPARG, HHEX, CDKN2A, SLC30A8, DUSP9, CDKAL1, ADCY5, SRR, WFS1, IRS1, DUSP8, HMGA2, TSPAN8 and CHCHD9. All analysed CpG-SNPs were associated with differential DNA methylation of the CpG-SNP site in human islets. Moreover, six CpG-SNPs, representing TCF7L2, KCNQ1, CDKN2A, ADCY5, WFS1 and HMGA2, were also associated with DNA methylation of surrounding CpG sites. Some of the type 2 diabetes CpG-SNP sites that exhibit differential DNA methylation were further associated with gene expression, alternative splicing events determined by splice index, and hormone secretion in the human islets. The 19 type 2 diabetes-associated CpG-SNPs are in strong linkage disequilibrium (r² > 0.8) with a total of 295 SNPs, including 91 CpG-SNPs.

CONCLUSIONS/INTERPRETATION

Our results suggest that the introduction or removal of a CpG site may be a molecular mechanism through which some of the type 2 diabetes SNPs affect gene function via differential DNA methylation and consequently contributes to the phenotype of the disease.

Osteocalcin, glucose metabolism, lipid profile and chronic low-grade inflammation in middle-aged and elderly Chinese

AIM

To assess the relationship between serum total osteocalcin and measurements of adiposity, glucose tolerance, lipid profile, adipokine and chronic low-grade inflammation in middle-aged and elderly Chinese subjects.

METHODS

We performed a cross-sectional community-based study in central Shanghai. Serum total osteocalcin was measured by radioimmunoassay in 783 men and 946 post-menopausal women. Their associations with measurements of adiposity, glucose tolerance, lipid profile and chronic low-grade inflammation were examined.

RESULTS

Serum total osteocalcin levels revealed a sexual dimorphism, with post-menopausal women having significantly higher levels than men (P < 0.001). Serum osteocalcin levels of participants with self-reported cardiovascular disease were significantly lower (P = 0.044) than those without. In men, serum osteocalcin levels of participants with the metabolic syndrome were significantly lower than those without the metabolic syndrome (P = 0.036). Serum osteocalcin correlated negatively with fasting serum insulin, homeostasis model assessment of insulin resistance, alanine aminotransferase, triglycerides and total cholesterol, and positively with homeostasis model assessment of β-cell function in both men and post-menopausal women (all P < 0.05). In men, serum osteocalcin correlated negatively with BMI, diastolic blood pressure, fasting plasma glucose and 2-h oral glucose tolerance test glucose after adjustment for age (all P < 0.05). In post-menopausal women, serum osteocalcin correlated negatively with waist-hip ratio, LDL cholesterol and C-reactive protein, and positively with adiponectin (all P < 0.05). Serum osteocalcin was not associated with CXC chemokine ligand 5 level (P > 0.05). Alanine aminotransferase was an independent predictor of serum osteocalcin in both men and post-menopausal women (both P < 0.001). Adiponectin was an independent predictor of serum osteocalcin in post-menopausal women (P = 0.011). Serum osteocalcin was an independent predictor of homeostasis model assessment of β-cell function in both genders (both P < 0.05).

CONCLUSIONS

Serum total osteocalcin was closely associated with glucose and lipid metabolism in both Chinese men and post-menopausal women.

Effects of short-term high-fat overfeeding on genome-wide DNA methylation in the skeletal muscle of healthy young men

AIMS/HYPOTHESIS

Energy-dense diets that are high in fat are associated with a risk of metabolic diseases. The underlying molecular mechanisms could involve epigenetics, as recent data show altered DNA methylation of putative type 2 diabetes candidate genes in response to high-fat diets. We examined the effect of a short-term high-fat overfeeding (HFO) diet on genome-wide DNA methylation patterns in human skeletal muscle.

METHODS

Skeletal muscle biopsies were obtained from 21 healthy young men after ingestion of a short-term HFO diet and a control diet, in a randomised crossover setting. DNA methylation was measured in 27,578 CpG sites/14,475 genes using Illumina's Infinium Bead Array. Candidate gene expression was determined by quantitative real-time PCR.

RESULTS

HFO introduced widespread DNA methylation changes affecting 6,508 genes (45%), with a maximum methylation change of 13.0 percentage points. The HFO-induced methylation changes were only partly and non-significantly reversed after 6-8 weeks. Alterations in DNA methylation levels primarily affected genes involved in inflammation, the reproductive system and cancer. Few gene expression changes were observed and these had poor correlation to DNA methylation.

CONCLUSIONS/INTERPRETATION

The genome-wide DNA methylation changes induced by the short-term HFO diet could have implications for our understanding of transient epigenetic regulation in humans and its contribution to the development of metabolic diseases. The slow reversibility suggests a methylation build-up with HFO, which over time may influence gene expression levels.

First-degree relatives of type 2 diabetic patients have reduced expression of genes involved in fatty acid metabolism in skeletal muscle

CONTEXT

First-degree relatives of patients with type 2 diabetes (FH+) have been shown to have decreased energy expenditure and decreased expression of mitochondrial genes in skeletal muscle. In previous studies, it has been difficult to distinguish whether mitochondrial dysfunction and differential regulation of genes are primary (genetic) or due to reduced physical activity, obesity, or other correlated factors.

OBJECTIVE

The aim of this study was to investigate whether mitochondrial dysfunction is a primary defect or results from an altered metabolic state.

DESIGN

We compared gene expression in skeletal muscle from 24 male subjects with FH and 26 without FH matched for age, glucose tolerance, VO(2peak) (peak oxygen uptake), and body mass index using microarrays. Additionally, type fiber composition, mitochondrial DNA content, and citrate synthase activity were measured. The results were followed up in an additional cohort with measurements of in vivo metabolism.

RESULTS

FH+ vs. FH- subjects showed reduced expression of mitochondrial genes (P = 2.75 × 10(-6)), particularly genes involved in fatty acid metabolism (P = 4.08 × 10(-7)), despite similar mitochondrial DNA content. Strikingly, a 70% reduced expression of the monoamine oxidase A (MAOA) gene was found in FH+ vs. FH- individuals (P = 0.0009). Down-regulation of the genes involved in fat metabolism was associated with decreased in vivo fat oxidation and increased glucose oxidation examined in an additional cohort of elderly men.

CONCLUSIONS

These results suggest that genetically altered fatty acid metabolism predisposes to type 2 diabetes and propose a role for catecholamine-metabolizing enzymes like MAOA in the regulation of energy metabolism.

Effect of progesterone on colonic motility and fecal output in mice with diarrhea

BACKGROUND

  Patients with diarrhea and slow transit constipation (STC) have high 5-HT levels. In STC, the high 5-HT levels have been difficult to explain, as 5-HT stimulates peristalsis. Over expression of progesterone (P4) receptors in epithelial and muscle cells of the colon may reconcile this contradiction because P4 decreases SERT and increases 5-HT levels, but their effects are rendered ineffective because of the impaired muscle contraction.

AIMS

  We examined whether P4 treatment could reduce the stool output in two mouse diarrheal models because of higher 5-HT levels, the SERT knock-out (KO), and the fluoxetine-treated mice.

METHODS

  Contractility of colon circular muscle strips from wild mice was studied. Fecal water and dry fecal output were measured daily over a 4-day period in wild and SERT-KO mice and in fluoxetine-treated mice treated with IM saline or P4. 5-HT levels were measured using ELISA.

KEY RESULTS

  Progesterone blocked the spontaneous and stimulated phasic contractions. Fecal water output measured in two consecutive 4-day periods was not different in wild and SERT-KO mice. The fecal output in the SERT-KO mice was higher than in wild mice. P4 treatment reduced the 4-day fecal output in both groups compared with saline treatment. Oral fluoxetine treatment increased 5-HT levels in wild mice and increased the 4-day fecal output compared with oral saline. P4 treatment caused a decrease in the fecal output in both groups.

CONCLUSIONS & INFERENCES

  Progesterone decreased the contractility of circular muscle strips, and reduced the fecal output in two diarrheal models, the SERT-KO and fluoxetine-treated mice.

Development of optimized AAV3 serotype vectors: mechanism of high-efficiency transduction of human liver cancer cells

Our recent studies have revealed that among the 10 different commonly used adeno-associated virus (AAV) serotypes, AAV3 vectors transduce human liver cancer cells extremely efficiently because these cells express high levels of human hepatocyte growth factor receptor (hHGFR), and AAV3 utilizes hHGFR as a cellular co-receptor for viral entry. In this report, we provide further evidence that both extracellular as well as intracellular kinase domains of hHGFR are involved in AAV3 vector entry and AAV3-mediated transgene expression. We also document that AAV3 vectors are targeted for degradation by the host cell proteasome machinery, and that site-directed mutagenesis of surface-exposed tyrosine (Y) to phenylalanine (F) residues on AAV3 capsids significantly improves the transduction efficiency of Y701F, Y705F and Y731F mutant AAV3 vectors. The transduction efficiency of the Y705+731F double-mutant vector is significantly higher than each of the single mutants in liver cancer cells in vitro. In immunodeficient mouse xenograft models, direct intratumoral injection of AAV3 vectors also led to high-efficiency transduction of human liver tumor cells in vivo. We also document here that the optimized tyrosine-mutant AAV3 vectors lead to increased transduction efficiency following both intratumoral and tail-vein injections in vivo. The optimized tyrosine-mutant AAV3 serotype vectors containing proapoptotic genes should prove useful for the potential gene therapy of human liver cancers.

Insulin promoter DNA methylation correlates negatively with insulin gene expression and positively with HbA(1c) levels in human pancreatic islets

AIMS/HYPOTHESIS

Although recent studies propose that epigenetic factors influence insulin expression, the regulation of the insulin gene in type 2 diabetic islets is still not fully understood. Here, we examined DNA methylation of the insulin gene promoter in pancreatic islets from patients with type 2 diabetes and non-diabetic human donors and related it to insulin expression, HbA(1c) levels, BMI and age.

METHODS

DNA methylation was analysed in 25 CpG sites of the insulin promoter and insulin mRNA expression was analysed using quantitative RT-PCR in pancreatic islets from nine donors with type 2 diabetes and 48 non-diabetic donors.

RESULTS

Insulin mRNA expression (p = 0.002), insulin content (p = 0.004) and glucose-stimulated insulin secretion (p = 0.04) were reduced in pancreatic islets from patients with type 2 diabetes compared with non-diabetic donors. Moreover, four CpG sites located 234 bp, 180 and 102 bp upstream and 63 bp downstream of the transcription start site (CpG -234, -180, -102 and +63, respectively), showed increased DNA methylation in type 2 diabetic compared with non-diabetic islets (7.8%, p = 0.03; 7.1%, p = 0.02; 4.4%, p = 0.03 and 9.3%, p = 0.03, respectively). While insulin mRNA expression correlated negatively (p < 1 × 10(-6)), the level of HbA(1c) correlated positively (p ≤ 0.01) with the degree of DNA methylation for CpG -234, -180 and +63. Furthermore, DNA methylation for nine additional CpG sites correlated negatively with insulin mRNA expression (p ≤ 0.01). Also, exposure to hyperglycaemia for 72 h increased insulin promoter DNA methylation in clonal rat beta cells (p = 0.005).

CONCLUSIONS/INTERPRETATIONS

This study demonstrates that DNA methylation of the insulin promoter is increased in patients with type 2 diabetes and correlates negatively with insulin gene expression in human pancreatic islets.