Normative reference of short-term heart rate variability and estimation of cardiovascular autonomic neuropathy prevalence in Chinese people

BACKGROUND

The cardiovascular autonomic neuropathy (CAN) prevalence is rapidly growing in all populations worldwide. This study aimed to evaluate the reference values for the short-term heart rate variable (HRV) and estimate CAN prevalence in our cross-sectional dataset.

METHODS

We conducted a large-scale, community-based, cross-sectional study in a Chinese population. Of 2,092 subjects available for data analysis, 371 healthy subjects were selected to reference the values for the short-term HRV. The short-term HRV analysis was performed for all subjects using a computer-aided examination and evaluation system for spectral analysis to investigate changes in autonomic regulation.

RESULTS

In the total sample, the reference value for total power was more than 356.13 ms(2). The cutoff points of 55.45 and 36.64 ms(2) were set for low frequency (LF) and high frequency (HF), respectively. The cutoff points of LFn and HFn were 6.40 and 4.83 ν, respectively. The normative reference of LF/HF ranged from 0.3 to 6.5. Using HRV test (model 1), the estimated age-adjusted CAN prevalence in the total sample was 16.83 %. The estimated age-adjusted CAN prevalence values were 31.07, 21.97 and 20.81 % in DM, HT, and MS patients, respectively.

CONCLUSION

Our findings provided reference values for short-term HRV. The estimated CAN prevalence was high in the Chinese population.

Clinical study of exercise on improvement of β-cell function and insulin resistance in non-diabetic young offsprings of diabetic patients

BACKGROUND

Previous studies have shown that exercise could improve β-cell function in humans or animal models of type 2 diabetes. However, whether it can prevent the progression of pre-diabetes to diabetes remains unclear.

AIM

To study the effects of exercise on glycolipid metabolism, β-cell function, and insulin resistance in the non-diabetic young offsprings of diabetic patients.

METHODS

One hundred and eighty-two normal glucose tolerance young offsprings of type 2 diabetic parents were enrolled. Individuals with fasting insulin ≥ 12.0 mU/L were assigned to hyperinsulinemia group (n = 72) and those with fasting insulin <12.0 mU/L were assigned to normal group (n = 110). The subjects in hyperinsulinemia group received 12-week exercise intervention. A 75-g oral glucose tolerance test and insulin release test were conducted before and after intervention. The area under curve of glucose (AUCglu), area under curve of insulin (AUCINS), HOMA insulin resistance index (HOMA-IR), HOMA β-cell function (HOMA-β), and early insulin secretion index (ΔI 30/ΔG 30) were calculated. Body composition was measured by dual energy X-ray absorptiometry.

RESULTS

At baseline, AUCINS and HOMA-β in hyperinsulinemia group were significantly higher compared with the normal group (P < 0.05). After the 12-week exercise intervention, no significant changes in blood pressure, body mass index, blood glucose, serum lipids, and percentage of body fat were found in hyperinsulinemia group; however, AUCINS, HOMA-β, HOMA-IR (P < 0.05) and ΔI 30/ΔG 30 (P < 0.01) were significantly decreased.

CONCLUSIONS

Exercise is effective for preventing pre-diabetic insulin resistance and β-cell dysfunction in non-diabetic young offsprings of diabetic patients.

Identification and characterization of the free fatty acid receptor 2 (FFA2) and a novel functional FFA2-like receptor (FFA2L) for short-chain fatty acids in pigs: evidence for the existence of a duplicated FFA2 gene (FFA2L) in some mammalian species

Free fatty acid receptor 2 (FFA2, also called GPR43) is reported to play a critical role in mediating the actions of short-chain fatty acids (SCFAs) in humans and mice. However, little is known about the structure, functionality, and tissue expression of FFA2 in other mammalian species, including pigs. In the present study, the full-length cDNAs of FFA2 (pFFA2) and a novel FFA2-like gene (named pFFA2L) were cloned from pig intestines by reverse transcription PCR. Both cloned pFFA2 and pFFA2L are predicted to encode 2 receptors of remarkable structural similarity and share high amino acid sequence identities with FFA2 from other mammalian species. Interestingly, the novel FFA2L could also be identified in 9 other mammalian species, suggesting that FFA2L was likely duplicated from FFA2 in the last common ancestor of these species. With the use of a pGL4-SRE-luciferase reporter assay, we demonstrated that pFFA2 expressed in human embryonic kidney 293 cells could be activated by acetate, propionate, and butyrate equipotently, whereas pFFA2L could be activated only by acetate and propionate, indicating that both pFFA2 and pFFA2L are functional receptors for SCFAs with nonidentical pharmacologic properties. Reverse transcription PCR found that pFFA2 mRNA was widely expressed in nearly all tissues examined, including adipose tissue and gastrointestinal (GI) tract, whereas pFFA2L expression was mainly restricted to the GI tract. Taken together, our findings raise a novel concept that the actions of SCFAs are likely mediated by 2 FFA2s (FFA2 and FFA2L) in target tissues of some mammalian species, such as the GI tract of pigs.

Genetic variants of 17q21 are associated with childhood-onset asthma and related phenotypes in a northeastern Han Chinese population: a case-control study

A genome-wide association study (GWAS) suggested that variants on chromosome 17q21 were associated with childhood-onset asthma in white populations. Two replication studies had been conducted in southern Han Chinese population in 2009 and 2012. However, these two Chinese replication results were inconsistent. To further confirm the role of 17q21 common variants, an association study of 17q21 single nucleotide polymorphisms (SNPs) with the risk of childhood-onset asthma was performed in a Han population from northeastern China. In this study, rs3894194, rs12603332 and rs11650680 were genotyped in 435 asthmatic children and 601 healthy controls by using a SNaPshot method. Our data showed that the allelic frequency of rs12603332 and rs11650680 showed significant differences between asthmatic cases and healthy controls, with an odds ratio (OR) of 1.36 [95% confidence interval (CI) 1.12-1.65, P=0.002] and an OR of 1.36 (95% CI 1.07-1.74, P=0.01). Genotype distribution analysis also showed the significant associations of the above two loci with childhood asthma under dominant, recessive and additive model (dominant OR=1.57, 95% CI 1.04-2.36, P=0.032; recessive OR=1.41, 95% CI 1.09-1.83, P=0.009; additive OR=1.97, 95% CI 1.24-3.14, P=0.004; recessive OR=1.50, 95% CI 1.13-1.98, P=0.005). Besides, linear regression analysis showed that rs3894194 and rs12603332 were also significantly associated with asthma phenotypes such as log10 -transformed immunoglobulin E (IgE) level (IU/ml) and log10 -transformed eosinophil percentage (dominant, P=0.04; additive, P=0.01; recessive, P=0.04; recessive, P=0.03; additive, P=0.02). Collectively, our findings suggest that orosomucoid 1-like 3 (ORMDL3) locus on chromosome 17q21 is a risk factor for childhood-onset asthma in northeastern Han Chinese population. Further studies will be needed to elucidate the pathogenesis that ORMDL3 locus predisposes to childhood-onset asthma.

Production and repair of implant-induced microdamage in the cortical bone of goats after long-term estrogen deficiency

SUMMARY

By using an ovariectomized goat model, we found that estrogen depletion decreases bone quality and makes it susceptible to screw-induced mechanical microdamage. Both diffuse microdamage and linear cracks accumulated up to 3 weeks after screw implantation, and the microdamage was repaired gradually after 4-8 months.

INTRODUCTION

The aim of this study was to observe the effect of long-term estrogen deficiency on the creation and repair of microdamage in cortical bone adjacent to bone screw.

METHODS

Cortical bone screws were placed in the tibial diaphyses 28 months after ovariectomy (OVX) or sham operation (Sham-Op) in female goats. The goats were euthanized at 0 day, 21 days, 4 months, and 8 months after screw implantation. Microdamage morphology and repair were examined in peri-screw bone using histomorphometric method, and the nanomechanical properties of peri-screw bone were examined with nanoindentation testing.

RESULTS

Tibiae from ovariectomized goats in which screws had been placed had significantly higher levels of diffuse microdamage and significantly more linear cracks than those from sham goats, and the diffuse microdamage was more obvious than linear cracks in the region adjacent to the implant. Both diffuse microdamage and linear cracks accumulated up to day 21 and then gradually repaired at 4 and 8 months after surgery. The trend for bone remodeling in each group was consistent with changes in the level of microdamage. Nanoindentation testing showed that both elastic modulus and hardness in peri-screw bone were significantly decreased in OVX group compared to Sham-Op group. The hardness and elastic modulus also showed a downward trend up to 4 months after screw implantation and then exhibited some recovery after 8 months.

CONCLUSIONS

Estrogen depletion decreases bone quality and makes it vulnerable to screw-induced mechanical damage, which may compromise the initial stability of an orthopedic implant.

Outcomes of SARS survivors in China: not only physical and psychiatric co-morbidities

The year 2013 marks the 10th anniversary of the outbreak of the severe acute respiratory syndrome (SARS). We present a comprehensive introduction to the current situation of surviving SARS victims in China where the disease originated and spread across the world 10 years ago.

Liver retraction using n-butyl-2-cyanoacrylate glue during single-incision laparoscopic upper abdominal surgery

BACKGROUND

Liver retraction is critical in single-incision laparoscopic upper abdominal surgery. Several techniques have been reported. Some need an additional port, whereas others are complicated and time-consuming.

METHODS

n-Butyl-2-cyanoacrylate (NBCA) glue was applied to bond the left lateral lobe of the liver to the diaphragm in different single-incision laparoscopic upper abdominal procedures. Liver adhesion time and duration of operation were recorded, and preoperative and postoperative liver function tests carried out.

RESULTS

All procedures were completed successfully without additional ports or special instruments. The technique provided adequate workspace and a clear view. Mean liver adhesion time was 1·5 min. The maximum operating time was 310 min. Levels of alanine and aspartate aminotransferases were raised on day 1 after surgery but had returned to normal by day 7.

CONCLUSION

Creating adhesion between the left lateral lobe of the liver and the diaphragm using NBCA glue is a simple, safe and effective way of achieving liver retraction in single-incision laparoscopic upper abdominal surgery.

α₁ adrenoceptor activation by norepinephrine inhibits LPS-induced cardiomyocyte TNF-α production via modulating ERK1/2 and NF-κB pathway

Cardiomyocyte tumour necrosis factor α (TNF-α) production contributes to myocardial depression during sepsis. This study was designed to observe the effect of norepinephrine (NE) on lipopolysaccharide (LPS)-induced cardiomyocyte TNF-α expression and to further investigate the underlying mechanisms in neonatal rat cardiomyocytes and endotoxaemic mice. In cultured neonatal rat cardiomyocytes, NE inhibited LPS-induced TNF-α production in a dose-dependent manner. α₁- adrenoceptor (AR) antagonist (prazosin), but neither β₁- nor β₂-AR antagonist, abrogated the inhibitory effect of NE on LPS-stimulated TNF-α production. Furthermore, phenylephrine (PE), an α₁-AR agonist, also suppressed LPS-induced TNF-α production. NE inhibited p38 phosphorylation and NF-κB activation, but enhanced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and c-Fos expression in LPS-treated cardiomyocytes, all of which were reversed by prazosin pre-treatment. To determine whether ERK1/2 regulates c-Fos expression, p38 phosphorylation, NF-κB activation and TNF-α production, cardiomyocytes were also treated with U0126, a selective ERK1/2 inhibitor. Treatment with U0126 reversed the effects of NE on c-Fos expression, p38 mitogen-activated protein kinase (MAPK) phosphorylation and TNF-α production, but not NF-κB activation in LPS-challenged cardiomyocytes. In addition, pre-treatment with SB202190, a p38 MAPK inhibitor, partly inhibited LPS-induced TNF-α production in cardiomyocytes. In endotoxaemic mice, PE promoted myocardial ERK1/2 phosphorylation and c-Fos expression, inhibited p38 phosphorylation and IκBα degradation, reduced myocardial TNF-α production and prevented LPS-provoked cardiac dysfunction. Altogether, these findings indicate that activation of α₁-AR by NE suppresses LPS-induced cardiomyocyte TNF-α expression and improves cardiac dysfunction during endotoxaemia via promoting myocardial ERK phosphorylation and suppressing NF-κB activation.

Roles of Wnt/β-catenin signaling in the gastric cancer stem cells proliferation and salinomycin treatment

The Wnt1 protein, a secreted ligand that activates Wnt signaling pathways, contributes to the self-renewal of cancer stem cells (CSCs) and thus may be a major determinant of tumor progression and chemoresistance. In a series of gastric cancer specimens, we found strong correlations among Wnt1 expression, CD44 expression, and the grade of gastric cancer. Stable overexpression of Wnt1 increased AGS gastric cancer cells' proliferation rate and spheroids formation, which expressed CSC surface markers Oct4 and CD44. Subcutaneous injection of nude mice with Wnt1-overexpressing AGS cells resulted in larger tumors than injection of control AGS cells. Salinomycin, an antitumor agent, significantly reduced the volume of tumor caused by Wnt1-overexpressing AGS cells in vivo. This is achieved by inhibiting the proliferation of CD44+Oct4+ CSC subpopulation, at least partly through the suppression of Wnt1 and β-catenin expression. Taken together, activation of Wnt1 signaling accelerates the proliferation of gastric CSCs, whereas salinomycin acts to inhibit gastric tumor growth by suppressing Wnt signaling in CSCs. These results suggest that Wnt signaling might have a critical role in the self-renewal of gastric CSCs, and salinomycin targeting Wnt signaling may have important clinical applications in gastric cancer therapy.

Species and sex-dependent toxicokinetics of 1-bromopropane: the role of hepatic cytochrome P450 oxidation and glutathione (GSH)

1. The objectives of the current studies were to evaluate the factors influencing the toxicokinetics of 1-bromopropane (1-BP) in rodents after intravenous (IV) and inhalation exposure. 2. F-344 rats were administered 1-BP via IV bolus injection at 5 and 20 mg/kg and blood concentration determined versus time. F-344 rats and B6C3F1 mice were also exposed to starting inhalation concentrations 70, 240, 800 and 2700 ppm 1-BP in a closed gas uptake system and chamber 1-BP levels were monitored for 6 h. Plasma bromide concentrations were determined to estimate total metabolized dose. Rats were pretreated with chemical inhibitors of cytochrome P450 and glutathione (GSH) synthesis, prior to exposure to 1-BP at 800 ppm within inhalation chambers. 3. Systemic clearance of 1-BP in rat was rapid and decreased with increasing dose. As inhalation chamber concentration of 1-BP increased, the terminal elimination rates decreased. Half-life of 1-BP in rats following inhibition of P450 (9.6 h) or depletion of GSH (4.1 h) increased relative to controls (2.0 h) at 800 ppm. The percentage of 1-BP metabolized decreased with increasing inhalation exposure. Hepatic levels of GSH were significantly lowered regardless of the exposure level in both rats and mice. Chamber concentration-time curves were fit to a two compartment model which was used to estimate metabolic rate constants. 4. These data suggest that in rat, 1-BP clearance is saturable and that elimination is highly dependent on both P450 and GSH-dependent metabolism. This investigation in rodents may provide an understanding of interspecies differences in toxicokinetics and eventually aid translation of animal studies to human risk assessment.

Meta analysis of the association of rs7702187 SNP in SEMA5A gene with risk of Parkinson's disease

AIM

The aim of our study was to derive a more precise estimation of the association between the SEMA5A rs7702187 polymorphism and the susceptibility for PD by using meta-analysis.

MATERIALS AND METHODS

We searched and collected articles in English or Chinese from the databases of Medline, PubMed, Embase, and Web of Science (updated to September 31, 2010) by using the search terms "semaphorin gene", "Parkinson's disease", "SNPs" and "polymorphism".

RESULTS

All of these selected studies should meet all of the inclusion criterias such as "case-control studies", "similar study method", "sufficient published data for estimating an odds ratio (OR) with 95% confidence interval (CI)". As a result, 12 studies in different populations including 3539 cases and 3250 controls were selected.

CONCLUSIONS

Our meta-analysis suggests that the Single-Nucleotide Polymorphism (SNP) of rs7702187 within the SEMA5A gene would be a high-penetrant risk factor for PD development in western population (p = 0.20 for heterogeneity, OR = 0.87, 95% CI = [0.79, 0.96]).

Association between oxidative stress and telomere length in Type 1 and Type 2 diabetic patients

BACKGROUND

Increasing evidence showed that telomere length was shorter in age-related diseases, but the mechanism of this phenomenon is still unclear.

AIM

To determine whether telomere shortening occurs in Type 1 diabetes (T1D) and Type 2 diabetes (T2D), and explore the effect of antioxidant status on the telomere length.

SUBJECTS AND METHODS

T2D patients (no.=62), T1D patients (no.=34), and non-diabetic subjects used as control (CTL) (no.=40) were included in this study. Leukocyte telomere length ratio (T/S ratio) was measured using a quantitative PCR and analyzed. Antioxidant status was estimated by human 8-hydroxy-desoxyguanosine quantization. Other biomarkers, such as fasting plasma glucose, fasting insulin, glycated hemoglobin (HbA1c) and lipid profile were also measured.

RESULTS

Compared with CTL group [T/S ratio (mean ± SD), 2.39 ± 0.55], leukocyte telomere length was significantly shorter in T2D group (1.67 ± 0.50) and T1D group (1.77 ± 0.50). 8-OHdG that indicated oxidative stress was significantly higher in T2D (2.99 ± 0.85 ng/ml) and T1D (2.03 ± 0.92 ng/ml) group than in CTL group (0.90 ± 0.46 ng/ml). T/S ratio was significantly negatively correlated with age, waist circumference, waist-to-hip ratio, diastolic blood pressure, fasting plasma glucose, HbA1c, homeostasis model assessment of insulin resistance and 8- OHdG in the whole population. 8-OHdG was independent risk factor for telomere shortening in both T1D (p=0.018) and T2D group (p=0.022).

CONCLUSIONS

In our study, shorter telomere length and increased oxidative stress were observed in both T1D and T2D. Older people with central obesity, hyperglycemia, insulin resistance and severe antioxidant status tended to have shorter telomere length. In addition, 8- OHdG was an independent predictor for telomere length for both T1D and T2D patients.

The Changes of Muscle FGF-6 Expression at Different Time Points after Exercise-induced Muscle Damage

OBJECTIVE

To investigate the changes of fibroblast growth factor (FGF)-6 expression in the regeneration and repair process after exercise-induced muscle damage (EIMD) and the relationship with skeletal muscle regeneration and repair.

METHODS

The expression of FGF-6 at different time points was examined by reverse transcription-polymerase chain reaction (PCR) and immunohistochemistry staining after a downhill treadmill exercise. Skeletal muscle injury and regeneration at different times after EIMD was assessed by haematoxylin and eosin (H and E) staining.

RESULTS

The FGF-6 protein expression was initially elevated and followed by a gradual reduction, while the changes of FGF-6 mRNA were almost all raised after the treadmill exercise.

CONCLUSION

The results point out that FGF-6 is closely related to skeletal muscle regeneration and repair, probably implying a dual function in muscle regeneration.

The pattern of thyroid function of subclinical hypothyroid women with levothyroxine treatment during pregnancy

In this study, we researched the pattern of thyroid function of subclinical hypothyroid (SCH) women with levothyroxine (LT4) throughout pregnancy and determined the optimal dosages of LT4 for such women. 56 SCH pregnant women were followed regularly prospectively. They were divided into three groups: group A (n = 29. Baseline TSH between 2.5 and 5.0 mIU/L) received 50 μg/day of LT4; group B (n = 17. Baseline TSH between 5.0 and 8.0 mIU/L) received 75 μg/day of L-T4; group C (n = 10. Baseline TSH >8.0 mIU/L) received 100 μg/day of LT4. All the patients started LT4 therapy around the 8th gestational week. Serum TSH, free T4, and free T3 were measured at 4-week intervals throughout pregnancy. Among the thyroid function indexes, serum TSH changed quickly and decreased significantly 4 weeks after LT4 therapy. The change of serum FT4 responded drastically at the 12th gestational week. We also found that serum FT3 did not change much after LT4 therapy. 50, 75, and 100 μg/day can maintain serum TSH level of 79.3, 82.4, and 90.0 % of SCH women in definitive therapeutic goal in group A, B, and C, respectively. The LT4 dose need to be adjusted one or more times in 20.7, 17.6, and 10.0 % of the SCH women in group A, B, and C, respectively. The different LT4 dose can be chosen according to the baseline TSH levels of SCH women. The constant LT4 dose can maintain serum TSH levels of 79.3-90 % patients in the ideal range. A small part of patients require adjust therapy also during the second and third trimester. Therefore, careful follow-up of SCH pregnant women should be taken, and thyroid function should be tested every month until the end of pregnancy.

Unprotected left main coronary artery disease after revascularization : effect of diabetes on patient outcomes

OBJECTIVE

It is unknown whether the effect of diabetes on patients with unprotected left main coronary artery (LMCA) disease differs according to the different revascularization strategies. This study was conducted to evaluate the impact of diabetes on patients with unprotected LMCA disease treated with either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

PATIENTS AND METHODS

We prospectively enrolled 823 consecutive patients with unprotected LMCA disease who had drug-eluting stent (DES; n = 331) implantation or underwent CABG (n = 492) in the study. We compared the effects of diabetes on clinical outcomes according to different revascularization strategies.

RESULTS

Among 823 eligible patients enrolled, 226 had diabetes. In the DES population, no significant differences were observed in occurrences of death, cardiac death, repeat revascularization, stroke, and major adverse cardiac and cerebrovascular events. However, the risks of the composite of death/myocardial infarction (MI)/stroke (21.5 % DM vs. 7.2 % non-DM; p = 0.001) and MI (15.4 % DM vs. 1.6 % non-DM; p = 0.000) were significantly higher in the diabetic patients than those without diabetes. In the CABG population, similar rates of all clinical endpoints were observed between the diabetic and nondiabetic group.

CONCLUSION

Diabetes was associated with worse outcome in patients undergoing DES implantation for the treatment of unprotected LMCA disease. However, its negative prognostic impact was not found among patients undergoing CABG.

DNA double-strand break repair is activated in carotid artery restenosis

Carotid stenosis is a narrowing or constriction of the inner surface of the carotid artery, usually caused by atherosclerosis. In the past decades, carotid angioplasty and stenting (CAS) has been developed into a credible option for the patients with carotid stenosis. However, restenosis remains a severe and unsolved issue after CAS treatment. Currently, the molecular mechanisms involved in the restenosis are still largely unclear. In this study, we found that the double-strand DNA breaks (DSBs) were induced by oxidative stress in the human carotid artery with restenosis by examining the level of γH2AX in the artery tissues. We further analyzed the activation of DNA damage repair pathways in the carotid restenosis. Our results suggest that non-homologues end joining (NHEJ), but not homologous recombination (HR), is mainly activated in the artery tissues with restenosis. Our results may provide clues to develop a new therapeutic strategy for carotid artery restenosis following CAS treatment.