Construction of a grpE-based plasmid addiction system in Escherichia coli and its application in phloroglucinol biosynthesis.

AIM: Biotechnical processes in Escherichia coli often operate with artificial plasmids. However, these bioprocesses frequently encounter plasmid loss. To ensure stable expression of heterologous genes in E. coli BL21(DE3), a novel plasmid addiction system (PAS) was developed. METHODS AND RESULTS: This PAS employed an essential gene grpE encoding a cochaperone in the DnaK-DnaJ-GrpE chaperone system as the selection marker, which represented a chromosomal ΔgrpE mutant harboring episomal expression plasmids that carry supplementary grpE alleles to restore the deficiency. To demonstrate the feasibility of this system, it was implemented in phloroglucinol (PG) biosynthesis, manifesting improved host tolerance to PG and increased PG production. Specifically, PG titer significantly improved from 0.78 ± 0.02 to 1.34 ± 0.04 g l-1, representing a 71.8% increase in shake-flask fermentation. In fed-batch fermentation, the titer increased from 3.71 ± 0.11 to 4.54 ± 0.10 g l-1, showing a 22.4% increase. RNA sequencing and transcriptome analysis revealed that the improvements were attributed to grpE overexpression and upregulation of various protective chaperones and the biotin acetyl-CoA carboxylase ligase coding gene birA. CONCLUSION: This novel PAS could be regarded as a typical example of nonanabolite- and nonmetabolite-related PAS. It effectively promoted plasmid maintenance in the host, improved tolerance to PG, and increased the titer of this compound.

Anti-adipogenic Effects of Sulforaphane-rich Ingredient with Broccoli Sprout and Mustard Seed in 3T3-L1 Preadipocytes.

Glucoraphanin (GRA) is a precursor of sulforaphane (SFN), which can be synthesized by the enzyme myrosinase. In this study, we developed and validated HPLC analytical methods for the determination of GRA and SFN in mustard seed powder (MSP), broccoli sprout powder (BSP), and the MSP-BSP mixture powder (MBP), and evaluated their anti-adipogenic effects in 3T3-L1 adipocytes. We found that the analysis methods were suitable for the determination of GRA and SFN in MSP, BSP, and MBP. The content of GRA in BSP was 131.11 ± 1.84 µmol/g, and the content of SFN in MBP was 162.29 ± 1.24 µmol/g. In addition, BSP and MBP effectively decreased lipid accumulation content without any cytotoxicity. Both BSP and MBP significantly inhibited the expression of adipogenic proteins and increased the expression of proteins related to lipolysis and lipid metabolism. BSP and MBP inhibited the expression of adipocyte protein 2 (aP2), CCAAT/enhancer-binding protein-α (C/EBP-α), and peroxisome proliferator-activated receptor-γ (PPAR-γ) in 3T3-L1 adipocytes, and inhibited the expression of fatty acid synthase (FAS) through AMP-activated protein kinase (AMPK). Meanwhile, BSP and MBP also increased the expression of the lipolysis-related proteins, uncoupling protein-1 (UCP-1) and carnitine palmitoyltransferase-1 (CPT-1). Moreover, MBP exerted anti-adipogenic to a greater extent than BSP in 3T3-L1 preadipocytes.

Phyllofenones F-M, Scalarane Sesterterpenes from the Marine Sponge Phyllospongia foliascens.

Eight new scalarane sesterterpenes, phyllofenones F-M (1-8), together with two known analogues, carteriofenones B and A (9-10), were isolated from the marine sponge Phyllospongia foliascens collected from the South China Sea. The structures of these compounds were determined based on extensive spectroscopic and quantum chemical calculation analysis. The antibacterial and cytotoxic activity of these compounds was evaluated. Among them, only compounds 4 and 6 displayed weak inhibitory activity against Staphylococcus aureus and Escherichia coli, with MIC values of 16 µg/mL and 8 µg/mL, respectively. Compounds 1-10 exhibited cytotoxic activity against the HeLa, HCT-116, H460, and SW1990 cancer cell lines, with IC50 values ranging from 3.4 to 19.8 µM.

In-Depth Understanding of Ecklonia stolonifera Okamura: A Review of Its Bioactivities and Bioactive Compounds.

Ecklonia stolonifera Okamura (ES) is mainly distributed in the coastal areas of the middle Pacific, around Korea and Japan, and has a long-standing edible value. It is rich in various compounds, such as polysaccharides, fatty acids, alginic acid, fucoxanthin, and phlorotannins, among which the polyphenol compound phlorotannins are the main active ingredients. Studies have shown that the extracts and active components of ES exhibit anti-cancer, antioxidant, anti-obesity, anti-diabetic, antibacterial, cardioprotective, immunomodulatory, and other pharmacological properties in vivo and in vitro. Although ES contains a variety of bioactive compounds, it is not widely known and has not been extensively studied. Based on its potential health benefits, it is expected to play an important role in improving the nutritional value of food both economically and medically. Therefore, ES needs to be better understood and developed so that it can be utilized in the development and application of marine medicines, functional foods, bioactive substances, and in many other fields. This review provides a comprehensive overview of the bioactivities and bioactive compounds of ES to promote in-depth research and a reference for the comprehensive utilization of ES in the future.

[Overview of systematic reviews on Kuntai Capsules in treatment of perimenopausal syndrome].

To evaluate the efficacy and safety of Kuntai Capsules in the treatment of perimenopausal syndrome. Systematic reviews on Kuntai Capsules in the treatment of perimenopausal syndrome were retrieved from Chinese and English databases from database establishment to August 31, 2020. AMSTER-2 scale, GRADE scale and ROBIS tools were used respectively to evaluate the methodological quality, evidence quality level and bias risk of the finally included systematic reviews. A total of 6 systematic reviews with 28 outcome indicators were included. The results of AMSTER-2 methodological quality assessment showed that one of the six systematic reviews was of low quality, and the other five were of extremely low quality. GRADE scale showed that 28 clinical outcome indicators were evaluated, three of which were intermediate-level ones, and the rest were low-level or very low-level ones. Two evidences of the three intermediate evidences were total efficiency, and the other intermediate evidence was Kupperman score. ROBIS bias risk assessment showed all the included studies were of high risk. The results showed that, Kuntai Capsules were effective in the treatment of perimenopausal symptoms, such as hot flashes and sweating. The improvement of E_2 level was not as good as that in the menopause hormone therapy group, but the incidence of adverse reactions was lower than that in the menopause hormone therapy group. However, the quality of evidence needs to be improved due to the low quality of methodology and high risk of bias. It is suggested that systematic review and reasonable design should be carried out in the future, and attention should be paid to the registration of research schemes. In addition, the research reports shall be prepared according to PRISMA statement.

Proteome sequencing and analysis of Ophiocordyceps sinensis at different culture periods.

BACKGROUND: Ophiocordyceps sinensis is an important traditional Chinese medicine for its comprehensive active ingredients, such as cordycepin, cordycepic acid, and Cordyceps polysaccharide. O. sinensis zjut, a special strain isolated from O. sinensis, has similar pharmacological functions to wild O. sinensis. Currently, O. sinensis with artificial cultivation has been widely studied, but systematic fundamental research at protein levels has not been determined. RESULTS: Proteomes of O. sinensis zjut at different culture periods (growth period, 3rd day; pre-stable period, 6th day; and stable period, 9th day) were relatively quantified by relative isotope markers and absolute quantitative technology. In total, 4005 proteins were obtained and further annotated with Gene Ontology, Kyoto Encyclopedia of Genes and Genomes database. Based on the result of the annotations, metabolic pathways of active ingredients, amino acids and fatty acid were constructed, and the related enzymes were exhibited. Subsequently, comparative proteomics of O. sinensis zjut identified the differentially expressed proteins (DEPs) by growth in different culture periods, to find the important proteins involved in metabolic pathways of active ingredients. 605 DEPs between 6d-VS-3d, 1188 DEPs between 9d-VS-3d, and 428 DEPs between 9d-VS-6d were obtained, respectively. CONCLUSION: This work provided scientific basis to study protein profile and comparison of protein expression levels of O. sinensis zjut, and it will be helpful for metabolic engineering works to active ingredients for exploration, application and improvement of this fungus.

Enhancement of protoplast preparation and regeneration of Hirsutella sinensis based on process optimization.

OBJECTIVE: To explore the optimal methods for the protoplast preparation and regeneration of Hirsutella sinensis by optimizing the limiting factors. RESULTS: During the treatment of enzymatic protoplast preparation, mycelium cultured for 7 days was the optimal start material. The maximum protoplast preparation rate of 4.3 × 107 protoplasts/g fresh weight (FW) was obtained after 0.5 h treatment of 1 mg/ml mixed lytic enzymes in KH2PO4-K2HPO4 buffer (pH 5.5) with 0.6 M KCl at 18 °C. As for the protoplast regeneration, the maximum protoplast regeneration rate reached 12.32% through 5 × 103 protoplasts mL-1 cultivated for 20 days in the regeneration medium with 0.6 M mannitol and 1.5% agar. CONCLUSIONS: The preparation and regeneration of H. sinensis protoplasts was firstly established based on process optimization and it provided a foundation for the study of H. sinensis mutagenesis.

Tracheal Ultrasound for the Accurate Confirmation of the Endotracheal Tube Position in Obese Patients.

OBJECTIVES: Obesity is a serious disorder that may lead to numerous difficulties in endotracheal tube (ETT) management. This study investigated the potential of tracheal ultrasound (TUS) for the accurate confirmation of the ETT position in obese patients. METHODS: A total of 68 obese patients undergoing tracheal intubation were enrolled in this study from January 2017 to June 2018. All patients received auscultation and TUS to evaluate the ETT position, which was ultimately verified by bronchoscopy. A correct position of the ETT was defined as placement at the trachea, whereas placement at the right/left main bronchus was classified as an incorrect position. RESULTS: We found 58 correct placements of the ETT at the trachea, 8 incorrect placements at the right main bronchus, and 2 incorrect placements at the left main bronchus. Compared with auscultation, TUS showed higher accuracy (85.29% versus 67.65%; P = .005), sensitivity (84.48% versus 67.24%; P = .005), and specificity (90.00% versus 70.00%; P < .001), as well as lower rates of false-positive (10.00% versus 30.00%; P < .001) and false-negative (15.52% versus 32.76%; P = .005) results for detecting the correct placement of the ETT, defined as placement at the trachea. CONCLUSIONS: Tracheal ultrasound is highly sensitive and specific in confirming the ETT position in obese patients.

Species Diversity and Functional Prediction of Surface Bacterial Communities on Aging Flue-Cured Tobaccos.

Microbes on aging flue-cured tobaccos (ATFs) improve the aroma and other qualities desirable in products. Understanding the relevant organisms would picture microbial community diversity, metabolic potential, and their applications. However, limited efforts have been made on characterizing the microbial quality and functional profiling. Herein, we present our investigation of the bacterial diversity and predicted potential genetic capability of the bacteria from two AFTs using 16S rRNA gene sequences and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) software. The results show that dominant bacteria from AFT surfaces were classified into 48 genera, 36 families, and 7 phyla. In addition, Bacillus spp. was found prevalent on both ATFs. Furthermore, PICRUSt predictions of bacterial community functions revealed many attractive metabolic capacities in the AFT microbiota, including several involved in the biosynthesis of flavors and fragrances and the degradation of harmful compounds, such as nicotine and nitrite. These results provide insights into the importance of AFT bacteria in determining product qualities and indicate specific microbial species with predicted enzymatic capabilities for the production of high-efficiency flavors, the degradation of undesirable compounds, and the provision of nicotine and nitrite tolerance which suggest fruitful areas of investigation into the manipulation of AFT microbiota for AFT and other product improvements.

Biosynthesis of Natural Rubber: Current State and Perspectives.

Natural rubber is a kind of indispensable biopolymers with great use and strategic importance in human society. However, its production relies almost exclusively on rubber-producing plants Hevea brasiliensis, which have high requirements for growth conditions, and the mechanism of natural rubber biosynthesis remains largely unknown. In the past two decades, details of the rubber chain polymerization and proteins involved in natural rubber biosynthesis have been investigated intensively. Meanwhile, omics and other advanced biotechnologies bring new insight into rubber production and development of new rubber-producing plants. This review summarizes the achievements of the past two decades in understanding the biosynthesis of natural rubber, especially the massive information obtained from the omics analyses. Possibilities of natural rubber biosynthesis in vitro or in genetically engineered microorganisms are also discussed.

Glycerol-3-Phosphate Acyltransferase 3 (OsGPAT3) is required for anther development and male fertility in rice.

Lipid molecules are key structural components of plant male reproductive organs, such as the anther and pollen. Although advances have been made in the understanding of acyl lipids in plant reproduction, the metabolic pathways of other lipid compounds, particularly glycerolipids, are not fully understood. Here we report that an endoplasmic reticulum-localized enzyme, Glycerol-3-Phosphate Acyltransferase 3 (OsGPAT3), plays an indispensable role in anther development and pollen formation in rice. OsGPAT3 is preferentially expressed in the tapetum and microspores of the anther. Compared with wild-type plants, the osgpat3 mutant displays smaller, pale yellow anthers with defective anther cuticle, degenerated pollen with defective exine, and abnormal tapetum development and degeneration. Anthers of the osgpat3 mutant have dramatic reductions of all aliphatic lipid contents. The defective cuticle and pollen phenotype coincide well with the down-regulation of sets of genes involved in lipid metabolism and regulation of anther development. Taking these findings together, this work reveals the indispensable role of a monocot-specific glycerol-3-phosphate acyltransferase in male reproduction in rice.

Incidence of deep venous thrombosis in Chinese patients undergoing arthroscopic knee surgery for cruciate ligament reconstruction.

PURPOSE: This study investigated the incidence of deep venous thrombosis (DVT) in patients undergoing arthroscopic cruciate ligament surgery. METHODS: A total of 282 patients were examined by color Doppler ultrasound preoperatively and 3 and 7 days postoperatively. RESULTS: DVT was present in 34 of 282 patients (12.1 %); of these, 11 (32.6 %) underwent reconstruction of the anterior cruciate ligament (ACL), alone or in conjunction with the medial or lateral collateral ligament (MCL or LCL, respectively; 17.6 %); eight (23.5 %) of the posterior cruciate ligament (PCL); four (11.8 %) of the PCL-MCL/LCL; and five (14.7 %) of the ACL-MCL. In patients with tourniquets applied for <90, 90-120, and >120 min, the incidence of DVT was 5.6, 12.8, and 17.4 %, respectively. CONCLUSION: The incidence of DVT in normal patients undergoing ACL surgery was 12.1 %. A higher incidence was observed among cases of multiligament reconstruction, especially those involving the PCL, as well as in patients with tourniquets applied for more than 2 h. Based on these findings, prophylactic measures for DVT may be considered after arthroscopic knee surgery in order to decrease the incidence of DVT if specific risk factors are present. LEVELS OF EVIDENCE: IV.

Angiosarcoma of the breast: A review.

Breast angiosarcoma is a rare and highly aggressive malignancy with a poor prognosis. It can occur spontaneously or be associated with factors such as radiation therapy or chronic lymphedema. The etiology and pathogenesis of this disease are still unclear, the clinical symptoms and imaging findings lack specificity, and the pathological morphology is diverse, which is easy to be confused with other diseases. There is no clear guideline for surgical treatment. Although the optimal surgical approach remains unclear, the ultimate goal is surgical excision with optimal margins, which remains the primary method of treatment. In clinical practice, the choice of the surgical approach should be made by considering the tumor size, pathological type, and patient preferences. In clinical practice, the selection of surgical methods should be carried out with comprehensive consideration of tumor size, pathological types and patients' wishes. There is no clear consensus on whether radiotherapy and chemotherapy should be carried out after surgery, and its optimal program and efficacy are uncertain. This article reviews the etiology, clinical manifestations, pathological features, imaging findings, treatment, prognosis and other aspects of breast angiosarcoma, so as to strengthen clinicians' overall understanding of this disease and avoid missed diagnosis and misdiagnosis.

Plant sources, extraction techniques, analytical methods, bioactivity, and bioavailability of sulforaphane: a review.

Sulforaphane (SFN) is an isothiocyanate commonly found in cruciferous vegetables. It is formed via the enzymatic hydrolysis of glucoraphanin by myrosinase. SFN exerts various biological effects, including anti-cancer, anti-oxidation, anti-obesity, and anti-inflammatory effects, and is widely used in functional foods and clinical medicine. However, the structure of SFN is unstable and easily degradable, and its production is easily affected by temperature, pH, and enzyme activity, which limit its application. Hence, several studies are investigating its physicochemical properties, stability, and biological activity to identify methods to increase its content. This article provides a comprehensive review of the plant sources, extraction and analysis techniques, in vitro and in vivo biological activities, and bioavailability of SFN. This article highlights the importance and provides a reference for the research and application of SFN in the future.

The feasibility and clinical significance of lateral approach thyroidectomy.

BACKGROUND: By comparing the three lateral approaches to thyroidectomy, the feasibility and clinical effects were analyzed, and the advantages of the lateral approach were summarized. METHODS: From January 2022 to January 2023, 52 patients with thyroid cancer admitted to our department were selected and subjected to Lateral approach for thyroidectomy. Among them, 31 patients underwent thyroidectomy via the supraclavicular approach, 13 patients underwent endoscopic thyroidectomy via the subclavicular approach, and 8 patients underwent endoscopic thyroidectomy via the axillary approach. The basic conditions, surgical conditions, complications, postoperative pain scores and postoperative satisfaction of patients in the three approach surgery groups were recorded and analyzed. RESULTS: There were no significant differences among the three approach groups in terms of patient characteristics, number of central lymph node dissections, intraoperative blood loss, postoperative drainage volume, duration of drainage tube placement, length of hospital stay, postoperative pain, satisfaction, and complications. However, the operation time was longest in the subclavicular approach group, followed by the axillary approach group, and shortest in the supraclavicular approach group. The total hospitalization cost was highest in the axillary approach group, followed by the subclavicular approach group, and lowest in the supraclavicular approach group. CONCLUSION: The lateral approach for thyroidectomy is deemed a safe and effective method. The three different approach paths gradually increase in length, allowing for the accumulation of anatomical experience. This approach has a shorter learning curve for clinical doctors and is a favorable choice for patients seeking aesthetic benefits.

Identification of marker compounds in fermented Benincasa hispida and validation of the method for its analysis.

Fermentation is a process that improves health functionality by inducing the production and increase of bioactive compounds. In this study, to standardize the fermentation process for Benincasa hispida, marker compounds that are increased or produced during fermentation were identified based on UPLC-QTOF-MS/MS. Analysis method verification and content analysis were conducted using HPLC-PDA. The marker compounds produced or increased in content were identified as 2-furoic acid, 2,3-dihydroxybenzoic acid, and rubinaphthin A by comparing their retention times, UV and MS spectra, and molecular formulas with those reported in previous studies. In addition, the increase in the content of the marker compounds by fermentation was confirmed, and the analytical method was validated by measuring its specificity, linearity, limit of detection and quantitation, precision, and accuracy. These results suggest that the developed fermentation process, marker compound identification, and verified analysis method can be applied to develop potential functional food ingredients from fermented B. hispida.

The Mechanism of the Anti-Obesity Effects of a Standardized Brassica juncea Extract in 3T3-L1 Preadipocytes and High-Fat Diet-Induced Obese C57BL/6J Mice.

Obesity is a global health concern. Recent research has suggested that the development of anti-obesity ingredients and functional foods should focus on natural products without side effects. We examined the effectiveness and underlying mechanisms of Brassica juncea extract (BJE) in combating obesity via experiments conducted in both in vitro and in vivo obesity models. In in vitro experiments conducted in a controlled environment, the application of BJE demonstrated the ability to suppress the accumulation of lipids induced by MDI in 3T3-L1 adipocytes. Additionally, it downregulated adipogenic-related proteins peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), adipocyte protein 2 (aP2), and lipid synthesis-related protein acetyl-CoA carboxylase (ACC). It also upregulated the heat generation protein peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and fatty acid oxidation protein carnitine palmitoyltransferase-1 (CPT-1). The oral administration of BJE decreased body weight, alleviated liver damage, and inhibited the accumulation of lipids in mice with diet-induced obesity resulting from a high-fat diet. The inhibition of lipid accumulation by BJE in vivo was associated with a decreased expression of adipogenic and lipid synthesis proteins and an increased expression of heat generation and fatty acid oxidation proteins. BJE administration improved obesity by decreasing adipogenesis and activating heat generation and fatty acid oxidation in 3T3-L1 cells and in HFD-induced obese C57BL/6J mice. These results suggest that BJE shows potential as a natural method for preventing metabolic diseases associated with obesity.

Ginsenosides Rh1, Rg2, and Rg3 ameliorate dexamethasone-induced muscle atrophy in C2C12 myotubes.

High doses or prolonged use of the exogenous synthetic glucocorticoid dexamethasone (Dex) can lead to muscle atrophy. In this study, the anti-atrophic effects of ginsenosides Rh1, Rg2, and Rg3 on Dex-induced C2C12 myotube atrophy were assessed by XTT, myotube diameter, fusion index, and western blot analysis. The XTT assay results showed that treatment with Rh1, Rg2, and Rg3 enhanced cell viability in Dex-injured C2C12 myotubes. Compared with the control group, the myotube diameter and fusion index were both reduced in Dex-treated cells, but treatment with Rh1, Rg2, and Rg3 increased these parameters. Furthermore, Rh1, Rg2, and Rg3 significantly downregulated the protein expression of FoxO3a, MuRF1, and Fbx32, while also upregulating mitochondrial biogenesis through the SIRT1/PGC-1α pathway. It also prevents myotube atrophy by regulating the IGF-1/Akt/ mTOR signaling pathway. These findings indicate that Rh1, Rg2, and Rg3 have great potential as useful agents for the prevention and treatment of muscle atrophy.

Or mutation leads to photo-oxidative stress responses in cauliflower (Brassica oleracea) seedlings during de-etiolation.

The Orange (Or) gene is a gene mutation that can increase carotenoid content in plant tissues normally devoid of pigments. It affects plastid division and is involved in the differentiation of proplastids or non-colored plastids into chromoplasts. In this study, the de-etiolation process of the wild type (WT) cauliflower (Brassica oleracea L. var. botrytis) and Or mutant seedlings was investigated. We analyzed pigment content, plastid development, transcript abundance and protein levels of genes involved in the de-etiolation process. The results showed that Or can increase the carotenoid content in green tissues, although not as effectively as in non-green tissues, and this effect might be caused by the changes in biosynthetic pathway genes at both transcriptional and post-transcriptional levels. There was no significant difference in the plastid development process between the two lines. However, the increased content of antheraxanthin and anthocyanin, and higher expression levels of violaxanthin de-epoxidase gene (VDE) suggested a stress situation leading to photoinhibition and enhanced photoprotection in the Or mutant. The up-regulated expression levels of the reactive oxygen species (ROS)-induced genes, ZAT10 for salt tolerance zinc finger protein and ASCORBATE PEROXIDASE2 (APX2), suggested the existence of photo-oxidative stress in the Or mutant. In summary, abovementioned findings provide additional insight into the functions of the Or gene in different tissues and at different developmental stages.

[Nocturnal heart rhythm disorder in patients with obstructive sleep apnea syndrome].

OBJECTIVE: To explore the clinical characteristics of patients with obstructive sleep apnea syndrome (OSAS) and nocturnal arrhythmia. METHODS: During September 2010 to August 2011, a total of 446 subjects were recruited from Department of Sleep Breathing Disorder, Third Hospital, Hebei Medical University to receive polysomnography examination and electrocardiogram monitoring. According to the results, they were classified as mild (5 ≤ AHI < 15/h) or moderate (15 ≤ AHI < 40/h) or severe (AHI ≥ 40/h) OSAS. Then the incidence of different types of arrhythmias, risk factors and the relationship with OSAS severity were examined. RESULTS: Among 446 patients, the incidence of arrhythmia was 24.4% (109/446). The severity of OSAS (r = 1.857, P = 0.043) and age (r = 1.030, P = 0.003) had a positive relationship with the incidence of arrhythmias.Sinus bradycardia (79.8%, 87/109) and accidental ventricular premature beat (54.1%, 59/109) were most likely to occur than other types of arrhythmias (P < 0.01).In moderate and severity OSAS patients, the incidence of sinus bradycardia, frequent atrial premature beat, combined over two kinds of arrhythmias, atrial fibrillation and atrioventricular block were 50.0%, 0, 42.9%, 7.1%,0 and 90.9%, 14.8%, 57.9%, 4.5%, 5.7% respectively. And they were significantly higher than those of mild patients (all = 0) (all P < 0.05). CONCLUSIONS: Age and severity of OSAS have a positive relationship with the incidence of nocturnal arrhythmias.Sinus bradycardia and ventricular premature beat are the most likely to occur in OSAS patients.In moderate and severe group, sinus bradycardia, frequent atrial premature beat, combined over two kinds of arrhythmias, atrial fibrillation and atrioventricular block are more commonly encountered.