[Analysis of risk factors for hyperkalemia in hemodialysis patients and establishment and verification of risk assessment model of hyperkalemia].

Objective: To explore risk factors for hyperkalemia in hemodialysis (HD) patients, and establish and verify a risk assessment model of hyperkalemia in HD patients. Methods: The clinical data of HD patients who were admitted to the Department of Nephrology of the First Affiliated Hospital of Zhengzhou University between April 2020 and January 2021 were retrospectively collected and divided into training dataset and validation dataset by using the conversion-random number generator. In the training dataset, multivariate logistic regression analysis was used to screen the risk factors for hyperkalemia in HD patients and the factors were scored to establish the risk assessment model. The validation dataset was substituted into the model and the receiver operating characteristic (ROC) curve was drawn and the area under the curve (AUC) was calculated to verify the effectiveness of the risk prediction model in predicting hyperkalemia. Results: A total of 502 HD patients were enrolled and further divided into training dataset (n=372) and validation dataset (n=130). There were 268 males and 234 females, with a mean age of (54±13) years. Multivariate logistic regression analysis showed that metabolic acidosis, high potassium diet, history of hyperkalemia, the change of electrocardiogram (ECG), disfunction of vascular access and time interval from last dialysis were risk factors for causing hyperkalemia in patients undergoing HD. Risk assessment model was established based on these risk factors. The AUC of the ROC curve was 0.799. Using 5 as the cut-off value, the sensitivity and specificity for predicting hyperkalemia events was 61.4% and 86.3%, respectively. Conclusion: The current study preliminarily established a risk assessment model for hyperkalemia in HD patients, which can help clinicians manage the potassium level of HD patients.

Risk factors and prognosis for the primary intraosseous carcinoma of the jaw.

Primary intraosseous carcinoma (PIOC) is a rare but aggressive type of odontogenic tumour arising within the jawbone. Diagnosis criteria and treatment strategy remain difficult and controversial. The present study aimed to clarify the clinicopathological features and determine prognostic factors in management of PIOC. A retrospective study of 30 patients with PIOC, treated at the Hospital of Stomatology of Sun Yat-sen University between 2009 and 2017, was conducted. Clinical, histopathological and treatment modality data were collected. Follow-up data were recorded to determine prognostic factors. There were 19 males and 11 females with a mean age of 52.3 years. The most common location of the tumour was the mandible (90%). Having a history of tooth extraction or tooth mobility was the major characteristic symptom (63.3%), jaw swelling coming in second (53.3%). Half of the patients underwent surgery alone. The estimated 2-year overall survival rate (OS) and recurrence-free survival rate (RFS) were 61.3% and 40.1%, respectively. Higher histological grade was an independent risk factor for poor OS (hazard ratio (HR) 0.233 [0.059-0.915], P=0.037), while at pN+ stage for RFS, HR=5.627 [1.199-26.409], P=0.029. Because of its rarity and intrabony site, the classification, staging and treatment guidelines for PIOC should be further studied and established.

[Levels of calcaneus bone mineral density in adults from 10 regions of China].

Objective: To describe the regional and population-related differences in calcaneus bone mineral density (BMD) across ten regions of China. Methods: Based on the results: from the second Re-survey of China Kadoorie Biobank project, in which 5% of the surviving participants were interviewed during 2013-2014 and 24 677 participants aged 38-87 years were included in the study. We excluded those people with missing data for BMD and important variables. Calcaneus BMD was measured using the quantitative ultrasound bone densitometer. We analyzed four indexes, including broadband ultrasound attenuation (BUA), speed of sound (SOS), stiffness index (SI), and T score. Results The average calcaneus BMDs of the present population were: BUA (109.7±12.6) dB/MHz, SOS (1 554.7±45.6) m/s, SI (88.3±18.8), T score (-0.74±1.28). Urban residents showed higher calcaneus BMD, so as in men. The calcaneus BMD decreased by age, with a larger decline seen in women. Current smokers and postmenopausal women presented lower calcaneus BMD, while in those who frequently drank milk or yogurt or being physically more active, had higher calcaneus BMD. Conclusion: Calcaneus BMD varied greatly among people from the ten regions of CKB study and among participants having different demographic characteristics, lifestyle behaviors or health conditions.

PDK2 promotes chondrogenic differentiation of mesenchymal stem cells by upregulation of Sox6 and activation of JNK/MAPK/ERK pathway.

This study was undertaken to clarify the role and mechanism of pyruvate dehydrogenase kinase isoform 2 (PDK2) in chondrogenic differentiation of mesenchymal stem cells (MSCs). MSCs were isolated from femurs and tibias of Sprague-Dawley rats, weighing 300-400 g (5 females and 5 males). Overexpression and knockdown of PDK2 were transfected into MSCs and then cell viability, adhesion and migration were assessed. Additionally, the roles of aberrant PDK2 in chondrogenesis markers SRY-related high mobility group-box 6 (Sox6), type ΙΙ procollagen gene (COL2A1), cartilage oligomeric matrix protein (COMP), aggrecan (AGC1), type ΙX procollagen gene (COL9A2) and collagen type 1 alpha 1 (COL1A1) were measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The expressions of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK) and extracellular regulated protein kinase (ERK) were measured. Overexpressing PDK2 promoted cell viability, adhesion and inhibited cell migration in MSCs (all P<0.05). qRT-PCR assay showed a potent increase in the mRNA expressions of all chondrogenesis markers in response to overexpressing PDK2 (P<0.01 or P<0.05). PDK2 overexpression also induced a significant accumulation in mRNA and protein expressions of JNK, p38MAPK and ERK in MSCs compared to the control (P<0.01 or P<0.05). Meanwhile, silencing PDK2 exerted the opposite effects on MSCs. This study shows a preliminary positive role and potential mechanisms of PDK2 in chondrogenic differentiation of MSCs. It lays the theoretical groundwork for uncovering the functions of PDK2 and provides a promising basis for repairing cartilage lesions in osteoarthritis.

Association of AGTR1 gene A1166C polymorphism with the risk of heart failure: a meta-analysis.

The aim of this study was to investigate the correlation between the A1166C polymorphism in the angiotensin II type 1 receptor (AT1R) gene and heart failure (HF) risk using meta­analysis. The PubMed database was searched, and data were extracted independently by two reviewers. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the strength of the associations. Statistical analysis was performed using the STATA 12.0 software. The results of the meta­analysis showed no significant association between the AT1R A1166C polymorphism and HF risk (AA vs CC: OR = 0.72, 95%CI = 0.31-1.68; AA vs AC: OR = 0.78, 95%CI = 0.52-1.18; dominant model: OR = 1.37, 95%CI = 0.92-2.04; recessive model: OR = 0.73, 95%CI = 0.30-1.75). In the subgroup analysis by ethnicity, the results also showed no significant association between A1166C polymorphism and susceptibility to HF in both Caucasian and Asian populations. In conclusion, this meta-analysis suggests that the A1166C polymorphism in AT1R may not be associated with susceptibility to HF. Further large and well-designed studies are needed to confirm these conclusions.

The determinations of nucleosome positioning.

OBJECTIVE: Nucleosomes are the basic packaging units of chromatin, determinants of nucleosome organization playing a major role in genome packaging. Although a wide variety of nucleosome organization factors have been considered separately across the whole or partial human genomic regions, it is unclarified that what the major determinants and their roles in scale are when being put all together. And it is also unknown that what the similarities and differences of determinants between different genomic features such as genes of different expression levels or genomic regions with different functions. MATERIALS AND METHODS: We detected commonalities and characteristics of nucleosome positioning determinants in different genes and regions with 1591486 nucleosomes identified by ourselves in human CD4+ cell. RESULTS: It was found that a distinct linear combination of about 20 nucleosome-positioning factors explained nucleosome occupancy for each genomic feature. In those linear combinations, 6 DNA sequence attributes (Roll stiffness and Twist stiffness, CT and AG, CG and shift stiffness) and a histone modification (H4R3me2) are shared. And other factors are varied. Roll stiffness and Twist stiffness are the most important features. They are dominant, alone explaining 96.61-98.45% of the positioning weight in each genomic feature. The characteristic factors in each combination are larger in number, but weaker in power. Numerous histone modifications play a subtle role for nucleosome positioning. CONCLUSIONS: The present study provides a more accurate positioning nucleosome-map with higher resolution and a dramatically simplified means to predict and understand intrinsic nucleosome occupancy in different genomic features in human CD4+ cell. Roll stiffness and Twist stiffness are the two most important determinants in all genomic features. They may dominate because they both determine the degree of DNA bending and correlates with many other DNA structural characteristics. Histone modifications play a role of subtle allocation for nucleosome occupancy.

Effect of GBOT on blood lipid and blood glucose metabolism in rats with atherosclerosis.

We observed the variation in in vivo blood lipid and blood glucose metabolism in rats with atherosclerosis after 5-(3,4-dihydroxy-phenyl)-1-piperidin-1-yl-penta-2,4-dien-1-one (GBOT) administration. Wistar rats aged 10 weeks received a high-fat diet to establish the atherosclerosis model. Metabolic indices related to blood lipid and blood glucose were measured before modeling and at 4 and 8 weeks after modeling. Liver fat levels in rats were measured at 8 weeks to analyze the relationship between liver fat and blood lipid levels. We examined the mechanism of blood lipid reduction. The levels of serum triglycerides, total cholesterol, and very-low-density lipoprotein cholesterol in rats in the control group were significantly decreased (P < 0.05) compared with those in the 4-week control group at 4 weeks and decreased significantly and continuously until the 8th week (P < 0.05). Compared with the 8-week control group, the blood glucose level in rats in the 8-week experimental group decreased significantly (P < 0.05), and the level of insulin sensitivity index decreased significantly (P < 0.05). Compared with the control group, triglyceride and total cholesterol levels per unit mass in rat liver tissue in the 8-week experimental group decreased significantly (P < 0.05). Western blotting indicated that GBOT significantly increased the expression of lecithin-cholesterol acyltransferase, low-density lipoprotein receptor, and cholesterol 7 alpha-hydroxylase proteins. GBOT can significantly decrease the levels of blood lipid and blood glucose in rat models of atherosclerosis, and its mechanism may be associated with the promotion of expression of lecithin-cholesterol acyltransferase, low-density lipoprotein receptor, and cholesterol 7 alpha-hydroxylase proteins.

QAM accommodated double-side band fast OFDM based on IDCT.

In this paper, we theoretically and experimentally prove that sub-carriers in double-side band fast orthogonal frequency division multiplexing (DSB-FOFDM) are orthogonal over a symbol interval independent of the signal phase and amplitude. Therefore, the commonly utilized DSB-FOFDM is quadrature amplitude modulation (QAM) accommodated; while previously DSB-FOFDM was usually modulated by amplitude shift keying (ASK) or binary phase shift keying (BPSK). In our proof-of-concept experiments, bit error ratio (BER) performance of 10 Gb/s quadrature phase shift keying (QPSK) modulated DSB-FOFDM was equivalent to that of 10 Gb/s QPSK modulated OFDM after 500 km standard single mode fiber (SSMF) transmission. 10 Gb/s QPSK modulated DSB-FOFDM largely outperformed the commonly utilized 4-ASK modulated DSB-FOFDM in BER performance. Additionally, BER performance of 10 Gb/s 16-QAM modulated DSB-FOFDM was equivalent to that of 10 Gb/s 16-QAM modulated OFDM after 500 km SSMF transmission.