The Prognostic Value of Peak Cardiac Power Output in Chinese Patients with Chronic Heart Failure

Background

Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO₂) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the “true” measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO₂. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO₂ in Chinese patients with CHF.

Methods

Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1±11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7±3.7 kg/m² and LVEF 38±9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths.

Results

Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO₂,VE/VCO₂ slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO₂≤13.4 ml.kg^-1.min^-1, and VE/VCO₂ slope≥39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2≤13.4 ml.kg^-1.min^-1 those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05).

Conclusions

Peak CPO was not a predictor of cardiac death in Chinese CHF patients.     

Vitamin C Intake and Pancreatic Cancer Risk: A Meta-Analysis of Published Case-Control and Cohort Studies

Background

Observational studies inconsistently reported the relationship between vitamin C intake and risk of pancreatic cancer. We conducted a meta-analysis of published case-control and cohort studies to quantify the association.

Methods

Potentially eligible studies were found on PubMed and EMBASE databases through May 31, 2015. A random-effects model was assigned to compute summary point estimates with corresponding 95% confidence intervals (CIs). Subgroup and meta-regression analyses were also performed to explore sources of heterogeneity.

Results

Our final analyses included 20 observational studies comprising nearly 5 thousand cases of pancreatic cancer. When comparing the highest with the lowest categories of vitamin C intake, the summary odds ratio/relative risk for case-control studies (14 studies), cohort studies (6 studies) and all studies combined was 0.58 (95% CI: 0.52–0.66), 0.93 (95% CI: 0.78–1.11) and 0.66 (95% CI: 0.58–0.75), respectively. The difference in the findings between case-control and cohort studies was statistically significant (P < .001). Possible publication bias was shown in the meta-analysis of case-control studies.

Conclusion

There is insufficient evidence to conclude any relationship between vitamin C intake and risk of pancreatic cancer. The strong inverse association observed in case-control studies may be affected by biases (eg, recall and selection biases) that particularly affect case-control studies and/or potential publication bias. Future prospective studies of vitamin C intake and pancreatic cancer are needed.     

Interocular Difference of Peripheral Refraction in Anisomyopic Eyes of Schoolchildren

Purpose

Refraction in the peripheral visual field is believed to play an important role in the development of myopia. The purpose of this study was to investigate the differences in peripheral refraction among anisomyopia, isomyopia, and isoemmetropia for schoolchildren.

Methods

Thirty-eight anisomyopic children were recruited and divided into two groups: (1) both eyes were myopic (anisomyopic group, AM group) and (2) one eye was myopic and the contralateral eye was emmetropic (emmetropic anisomyopic group, EAM group). As controls, 45 isomyopic and isoemmetropic children were also recruited with age and central spherical equivalent (SE) matched to those of the AM and EAM groups. The controls were divided into three groups: (1) intermediate myopia group (SE matched to the more myopic eye of AM group), (2) low myopia group (SE matched to the less myopic eye of AM group and the more myopic eye of EAM group), and (3) emmetropia group (SE matched to the less myopic eye of EAM group). Peripheral refraction at 7 points across the central ±30° on the horizontal visual field with a 10° interval was measured with an autorefractor. Axial length (AL), corneal curvature (CC), and anterior chamber depth (ACD) were also determined by using the Zeiss IOL-Master.

Results

The relative peripheral spherical equivalent [RPR(M)] and relative peripheral spherical value [RPR(S)] of the more myopic eye was shifted more hyperopically than the contralateral eye in both the AM and the EAM groups (both p<0.0001). The RPR(M, S) of the less myopic eyes in the AM and EAM groups showed a relatively flat trend across the visual field and were not significantly different from the emmetropia group. The RPR(M, S) of less myopic eyes in the AM group were shifted less hyperopically than in the isomyopic low myopia group and the more myopic eye of the EAM group [RPR(M), p = 0.007; RPR(S), p = 0.001], although the central SEs of the three groups were not significantly different from each other. However, RPR(M, S) of the more myopic eyes were not different from the corresponding isomyopic groups. There was also no significant difference in the relative peripheral astigmatism [RPR(J0, J45)] between the more and the less myopic eyes in either the AM or the EAM group.

Conclusion

Refraction of anisomyopia differs between the two eyes not only at the central visual field but also at the off-axis periphery. The relative peripheral refraction of the more myopic eye of anisomyopia was shifted hyperopically, as occurs in isomyopia with similar central subjective SE values. Less myopic eyes were much less hyperopically shifted in relative peripheral refraction than the corresponding isomyopic eyes, but are comparable to emmetropic eyes. This emmetropia-like relative peripheral refraction in less myopic eyes might be a factor responsible for slowing down the progression of myopia.     

Characterization of Behavioral,Neuropathological, Brain Metabolic and Key Molecular Changes in zQ175 Knock-In Mouse Model of Huntington’s Disease

Huntington’s disease (HD) is caused by an expansion of the trinucleotide poly (CAG) tract located in exon 1 of the huntingtin (Htt) gene leading to progressive neurodegeneration in selected brain regions, and associated functional impairments in motor, cognitive, and psychiatric domains. Since the discovery of the gene mutation that causes the disease, mouse models have been developed by different strategies. Recently, a new model, the zQ175 knock-in (KI) line, was developed in an attempt to have the Htt gene in a context and causing a phenotype that more closely mimics HD in humans. The behavioral phenotype was characterized across the independent laboratories and important features reminiscent of human HD are observed in zQ175 mice. In the current study, we characterized the zQ175 model housed in an academic laboratory under reversed dark-light cycle, including motor function, in vivo longitudinal structural MRI imaging for brain volume, MRS for striatal metabolites, neuropathology, as well as a panel of key disease marker proteins in the striatum at different ages. Our results suggest that homozygous zQ175 mice exhibited significant brain atrophy before the motor deficits and brain metabolite changes. Altered striatal medium spiny neuronal marker, postsynaptic marker protein and complement component C1qC also characterized zQ175 mice. Our results confirmed that the zQ175 KI model is valuable in understanding of HD-like pathophysiology and evaluation of potential therapeutics. Our data also provide suggestions to select appropriate outcome measurements in preclinical studies using the zQ175 mice.     

Comparative Screening of Digestion Tract Toxic Genes in Proteus mirabilis

Proteus mirabilis is a common urinary tract pathogen, and may induce various inflammation symptoms. Its notorious ability to resist multiple antibiotics and to form urinary tract stones makes its treatment a long and painful process, which is further challenged by the frequent horizontal gene transferring events in P. mirabilis genomes. Three strains of P. mirabilis {"type":"entrez-nucleotide","attrs":{"text":"C02011","term_id":"1434241"}}C02011/{"type":"entrez-nucleotide","attrs":{"text":"C04010","term_id":"1467261"}}C04010/C04013 were isolated from a local outbreak of a food poisoning event in Shenzhen, China. Our hypothesis is that new genes may have been acquired horizontally to exert the digestion tract infection and toxicity. The functional characterization of these three genomes shows that each of them independently acquired dozens of virulent genes horizontally from the other microbial genomes. The representative strain {"type":"entrez-nucleotide","attrs":{"text":"C02011","term_id":"1434241"}}C02011 induces the symptoms of both vomit and diarrhea, and has recently acquired a complete type IV secretion system and digestion tract toxic genes from the other bacteria.     

Simultaneous Determination of Glass Transition Temperatures of Several Polymers

Aims

A simple and easy optical method is proposed for the determination of glass transition temperature (T_g) of polymers.

Methods & Results

T_g was determined using the technique of microsphere imaging to monitor the variation of the refractive index of polymer microsphere as a function of temperature. It was demonstrated that the method can eliminate most thermal lag and has sensitivity about six fold higher than the conventional method in T_g determination. So the determined T_g is more accurate and varies less with cooling/heating rate than that obtained by conventional methods. The most attractive character of the method is that it can simultaneously determine the T_g of several polymers in a single experiment, so it can greatly save experimental time and heating energy.

Conclusion

The method is not only applicable for polymer microspheres, but also for the materials with arbitrary shapes. Therefore, it is expected to be broadly applied to different fundamental researches and practical applications of polymers.     

Access to Bacteriologic-Based Diagnosis in Smear Positive Retreatment Tuberculosis Patients in Rural China: A Cross-Sectional Study in Three Geographic Varied Provinces

Objective

To determine factors influencing the utilization and accessibility to bacteriologic-based tuberculosis (TB) diagnosis among sputum smear positive (SS+) retreatment TB patients, and to develop strategies for improving the case detection rate of MDR-TB in rural China.

Study Design and Setting

A cross-sectional study of SS+ TB retreatment patients was conducted in eight counties from three provinces with different implementation period and strategy of MDR-TB program in China. Demographic and socioeconomic parameters were collected by self-reporting questionnaires. Sputum samples were collected and cultured by the laboratory of county-designated TB clinics and delivered to prefectural Centers for Disease Prevention and Control (CDC) labs for DST with 4 first-line anti-TB drugs.

Results

Among the 196 SS+ retreatment patients, 61.22% received culture tests during current treatment. Patients from more developed regions (OR = 24.0 and 3.6, 95% CI: 8.6–67.3 and 1.1–11.6), with better socio-economic status (OR = 3. 8, 95% CI: 1.3–10.7), who had multiple previous anti-TB treatments (OR = 5.0, 95% CI: 1.6–15.9), and who failed in the most recent anti-TB treatment (OR = 2.6, 95% CI: 1.0–6.4) were more likely to receive culture tests. The percentage of isolates resistant to any of first-line anti-TB drugs and MDR-TB were 50.0% (95% CI: 39.8%-60.2%) and 30.4% (95% CI: 21.0%-39.8%) respectively.

Conclusions

Retreatment SS+ TB patients, high risk MDR-TB population, had poor utilization of access to bacteriologic-based TB diagnosis, which is far from optimal. The next step of anti-TB strategy should be focused on how to make bacteriological-based diagnosis cheaper, safer and more maneuverable, and how to assure the DST-guided treatment for these high-risk TB patients.     

A Noise-Filtering Method for Link Prediction in Complex Networks

Link prediction plays an important role in both finding missing links in networked systems and complementing our understanding of the evolution of networks. Much attention from the network science community are paid to figure out how to efficiently predict the missing/future links based on the observed topology. Real-world information always contain noise, which is also the case in an observed network. This problem is rarely considered in existing methods. In this paper, we treat the existence of observed links as known information. By filtering out noises in this information, the underlying regularity of the connection information is retrieved and then used to predict missing or future links. Experiments on various empirical networks show that our method performs noticeably better than baseline algorithms.