Atrial Arrhythmias in Patients with Severe COVID-19.

The number of confirmed COVID-19 cases has increased drastically; however, information regarding the impact of this disease on the occurrence of arrhythmias is scarce. The aim of this study was to determine the impact of COVID-19 on arrhythmia occurrence. This prospective study included patients with COVID-19 treated at the Leishenshan Temporary Hospital of Wuhan City, China, from February 24 to April 5, 2020. Demographic, comorbidity, and arrhythmias data were collected from patients with COVID-19 (n = 84) and compared with control data from patients with bacterial pneumonia (n = 84) infection. Furthermore, comparisons were made between patients with severe and nonsevere COVID-19 and between older and younger patients. Compared with patients with bacterial pneumonia, those with COVID-19 had higher total, mean, and minimum heart rates (all P < 0.01). Patients with severe COVID-19 (severe and critical type diseases) developed more atrial arrhythmias compared with those with nonsevere symptoms. Plasma creatine kinase isoenzyme (CKMB) levels (P=0.01) were higher in the severe group than in the nonsevere group, and there were more deaths in the severe group than in the nonsevere group (6 (15%) vs. 3 (2.30%); P=0.05). Premature atrial contractions (PAC) and nonsustained atrial tachycardia (NSAT) were significantly positively correlated with plasma CKMB levels but not with high-sensitive cardiac troponin I or myoglobin levels. Our data demonstrate that COVID-19 patients have higher total, mean, and minimum heart rates compared with those with bacterial pneumonia. Patients with severe or critical disease had more frequent atrial arrhythmias (including PAC and AF) and higher CKMB levels and mortality than those with nonsevere symptoms.

Prognostic value of free triiodothyronine in patients with dilated cardiomyopathy.

BACKGROUND: The association between free triiodothyronine (FT3) and long-term prognosis in dilated cardiomyopathy (DCM) patients has not been evaluated. The purpose of this study was to determine whether the level of FT3 could provide prognostic value in patients with DCM. METHODS: Data of consecutive patients diagnosed with DCM were collected from October 2009 to December 2014. FT3 was measured by fluoroimmunoassay. Other biochemical markers, such as free thyroxin (FT4), thyroid-stimulating hormone, red blood cell, hemoglobin, blood urea nitrogen, and serum creatinine, were tested at the same time. Follow-up was performed every 3 months. The primary endpoint was all-cause mortality. Pearson analysis was used to evaluate the correlation of FT3 and other lab metrics with DCM patients' prognosis. The association of long-term mortality in DCM and FT3 was compared using Cox hazards model. RESULTS: Data of 176 patients diagnosed with DCM were collected. Of them, 24 patients missed FT3 values and six patients were lost to follow-up. Altogether, data of 146 patients were analyzed. During the median follow-up time of 79.9 (53.5-159.6) months, nine patients lost, 61 patients died (non-survival group), and 85 patients survived (survival group). FT3 was significantly lower in non-survival group than that in survival group (3.65 ±â€Š0.83 pmol/L vs. 4.36 ±â€Š1.91 pmol/L; P = 0.003). FT3 also showed a significantly positive correlation with red blood cell and hemoglobin, negatively correlated with age, blood urea nitrogen and serum creatinine (P < 0.05), respectively. Patients in the group of lower FT3 levels (FT3 ≤3.49 pmol/L) suffered from a higher risk of all-cause mortality (P for log-rank = 0.001). In multivariate Cox regression analysis, FT3 level was significantly associated with all-cause mortality (hazard ratio: 0.70, 95% confidence interval 0.52-0.95, P for trend = 0.021). CONCLUSION: Low levels of FT3 were associated with increased all-cause mortality in patients with DCM.

Engineering cell wall synthesis mechanism for enhanced PHB accumulation in E. coli.

The rigidity of bacterial cell walls synthesized by a complicated pathway limit the cell shapes as coccus, bar or ellipse or even fibers. A less rigid bacterium could be beneficial for intracellular accumulation of poly-3-hydroxybutyrate (PHB) as granular inclusion bodies. To understand how cell rigidity affects PHB accumulation, E. coli cell wall synthesis pathway was reinforced and weakened, respectively. Cell rigidity was achieved by thickening the cell walls via insertion of a constitutive gltA (encoding citrate synthase) promoter in front of a series of cell wall synthesis genes on the chromosome of several E. coli derivatives, resulting in 1.32-1.60 folds increase of Young's modulus in mechanical strength for longer E. coli cells over-expressing fission ring FtsZ protein inhibiting gene sulA. Cell rigidity was weakened by down regulating expressions of ten genes in the cell wall synthesis pathway using CRISPRi, leading to elastic cells with more spaces for PHB accumulation. The regulation on cell wall synthesis changes the cell rigidity: E. coli with thickened cell walls accumulated only 25% PHB while cell wall weakened E. coli produced 93% PHB. Manipulation on cell wall synthesis mechanism adds another possibility to morphology engineering of microorganisms.

The rs6817105 polymorphism on chromosome 4q25 is associated with the risk of atrial fibrillation in the Chinese Han population.

OBJECTIVE: Previous genome-wide association studies (GWASs) have identified rs6817105-a single nucleotide polymorphism (SNP) on chromosome 4q25-to be associated with the risk of atrial fibrillation (AF) in a European-descent population. We recently demonstrated this association in a large cohort of Japanese ancestry. Our present study was designed to determine this association in the Chinese Han population. METHODS: This case-control study included 597 AF cases and 996 AF-free controls, and rs6817105 SNPs were genotyped using the TaqMan allelic discrimination assay. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated in logistic regression models. RESULTS: The genotype distribution of rs6817105-CC was significantly more frequent in the AF patients than in the controls (p=3.24×10-32). In our study, logistic regression analysis showed a strong association between rs6817105 and the risk of AF (additive model: OR=2.22, 95%CI=1.89-2.61, p=2.33×10-22; dominant model: OR=2.96, 95%CI: 2.16-4.07, p=2.03×10-11; recessive model: OR=2.83, 95%CI=2.27-3.54, p=4.00×10-20). Stratification analyses showed a borderline statistical difference between subgroups of age for the association of rs6817105 with AF risk (p=0.049). However, further interactive analysis indicated no significant interaction between genotype of rs6817105 and age (p=0.178). CONCLUSION: Our finding suggested that SNP rs6817105 may be associated with a high significant risk of AF in the Chinese Han population, although more replicative studies of larger sample size are needed to confirm this finding.

Association of rs17042171 with chromosome 4q25 with atrial fibrillation in Chinese Han populations.

OBJECTIVE: A recent genome-wide association study (GWAS) identified a susceptibility single nucleotide polymorphism (SNP), rs17042171 on 4q25 for atrial fibrillation (AF). The aim of the present study was to investigate whether this association between rs17042171 and AF also exists in Chinese Han populations. METHODS: It was a case-control study. We enrolled a total of 1,593 Chinese Han origin individuals in the study, including 597 AF patients and 996 AF-free controls. Genotyping was performed using the TaqMan allelic discrimination Assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in logistic regression models. RESULTS: There was strongly significant difference between AF patients and control subjects regarding rs17042171 assumption of additive model (OR=2.20, 95% CI: 1.88-2.57, p=2.00 × 10(-22)), dominant model (OR=2.99; 95% CI: 2.19-4.09; p=6.47 × 10(-12)) and a recessive (OR=2.75; 95% CI: 2.21-3.43; p=1.30 × 10(-19)). In the stratification analysis based on age, gender, hypertension, diabetes and coronary artery disease, there was no significant difference of the associations for rs17042171 among the subgroups. CONCLUSION: Our results indicated that rs17042171 confers an increased risk of AF in Chinese Han Populations and expanded the association to non-European ancestry populations for the first time.

The rs3807989 G/A polymorphism in CAV1 is associated with the risk of atrial fibrillation in Chinese Han populations.

BACKGROUND: A recent meta-analysis of several genome-wide association studies identified six new susceptibility single nucleotide polymorphisms (SNPs) for atrial fibrillation (AF) in individuals of the European ancestry. We aimed to replicate the associations between these SNPs and the risk of AF in a Chinese Han population. METHODS: We genotyped six SNPs (rs3903239 in PRRX1, rs3807989 in CAV1, rs10821415 in C9orf3, rs10824026 in SYNPO2L, rs1152591 in SYNE2, and rs7164883 in HCN4) using the middle-throughput iPLEX Sequenom MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in logistic regression models. RESULTS: We enrolled a total of 1,593 Chinese Han origin individuals in the study, including 597 AF patients and 996 non-AF controls. Among the six SNPs analyzed in the study, the SNP rs3807989 in CAV1 on chromosome 7q31 was found to be significantly associated with a decreased risk of AF (crude OR = 0.76, 95% CI: 0.64-0.89, P = 0.001; adjusted OR = 0.75, 95% CI: 0.63-0.89, P = 0.001). There were no significant associations between the other five loci and AF risk. CONCLUSION: Our results confirmed that CAV1 rs3807989 may contribute to a decreased AF risk in Chinese Han populations. However, further validation studies with different ethnic backgrounds and biological function analyses are warranted to confirm our finding.

Genetic polymorphisms in ZFHX3 are associated with atrial fibrillation in a Chinese Han population.

BACKGROUND: The gene zinc finger homeobox 3 (ZFHX3) encodes a transcription factor with cardiac expression and its genetic variants are associated with atrial fibrillation (AF). We aimed to explore the associations between single nucleotide polymorphisms (SNPs) of ZFHX3 and the risk of AF in a Chinese Han population. METHODS: We genotyped eight SNPs, including seven potentially functional SNPs and one previously reported SNP by using the middle-throughput iPLEX Sequenom MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in logistic regression models. RESULTS: We enrolled a total of 1,593 Chinese Han origin individuals in the study, including 597 AF patients and 996 non-AF controls. Logistic regression analyses revealed that potentially functional SNPs rs6499600 and rs16971436 were associated with a decreased risk of AF (adjusted OR  = 0.73, 95% CI: 0.63-0.86, P = 1.07×10-4; adjusted OR  = 0.74, 95% CI: 0.56-0.98, P = 0.039, respectively). In addition, rs2106261 showed a robust association with an increased risk of AF (adjusted OR  = 1.71, 95% CI: 1.46-2.00, P = 1.85×10-11). After multiple comparisons, rs16971436 conferred a borderline significant association with the risk of AF. Stratification analysis indicated that the risks of AF were statistically different among subgroups of age for rs2106261, and the effect for rs16971436 was more evident in subgroups of patients with coronary artery disease. CONCLUSION: In summary, our study investigated the role of genetic variants of ZFHX3 in AF and two SNPs (rs2106261, rs6499600) showed significant associations while rs16971436 conferred a borderline significant association with AF risk in Chinese Han populations. However, further large and functional studies are warranted to confirm our findings.

[Characteristics of heat resource in mountainous region of northern Guangdong, South China based on three-dimensional climate observation].

Based on the 2009-2011 daily air temperature observation data from 11 automatic weather stations in the mountainous region of northern Guangdong, this paper calculated the heat factors in the region, including the beginning date of 10 degrees C, the ending date of 15 degrees C, the duration days of 10-15 degrees C, the accumulated temperature above 10 degrees C, the days of minimum temperature below 5 degrees C, and the mean monthly temperature, with the linear regression model of the heat factors and latitude established. In 2009-2011, the heat factors in the region had significant correlations with latitude, and the heat resource at the same latitudes differed apparently between south and north slopes. With the increase of latitude, the beginning date of 10 degrees C delayed, the ending date of 10 degrees C advanced, and the duration days of 10-15 degrees C, the accumulated temperature above 10 degrees C, the days of temperature above 10 degrees C, and the mean annual air temperature decreased. The vertical variation rates of the heat factors were larger on south slope than on north slope. The results of this study could be used for fitting the vertical distribution of heat resource in the areas with no weather station, and provide basis for the fine regionalization of agricultural climate.