Bronchogenic cysts with infection in the chest wall skin of a 64-year-old asymptomatic patient: A case report.

BACKGROUND: Skin bronchogenic cysts are extremely rare congenital bronchocystic changes caused by the abnormal development of the trachea, bronchial trees or lung buds during the embryonic period. The first case of skin bronchogenic cysts was reported in 1945. Since then, this disease has attracted increasing attention, but due to the low incidence, its pathogenesis is still not clear. CASE SUMMARY: Here, we report another case of skin bronchogenic cysts with infection in a 64-year-old female patient. The patient had no symptoms for more than 60 years until her chest wall was recently found to be swollen, and she felt pain and discomfort. At the same time, secretions were found on the surface of the swelling. Color Doppler ultrasound examination showed abnormal echoes in the soft tissue under the frontal chest wall, suggesting the presence of cysts. Cytological puncture resulted in about 2 mL of pus and showed the presence of more acute inflammatory cells. The final clinical diagnosis was skin cyst with infection, and surgery was carried out. The pathological results obtained after surgery showed that the cystic wall was covered with column-like cilia epithelial cells, and the interstitial structure was partially inundated with inflammatory cells. After a variety of examinations and clinical diagnoses, we finally confirmed that the patient was suffering from bronchogenic cyst. CONCLUSION: This article not only describes the case of an elderly patient with rare skin bronchogenic cysts with infection but also provides a detailed and correct diagnosis and a successful treatment process, which is of great value for the diagnosis and treatment of the disease.

Hepatoprotective Constituents of Total Dibenzocyclooctadiene Lignans from Schisandra chinensis Based on the Spectrum-Effect Relationship.

To scientifically clarify the hepatoprotective constituents of Fructus Schizandrae chinensis, eleven batches samples of total dibenzocyclooctadiene lignans (TDL) from Schisandra chinensis were prepared by using the optimum extraction technique. Characteristic high-performance liquid chromatography (HPLC) chromatograms were obtained through HPLC analysis technology, and the hepatoprotective effects of the eleven batches of TDL were evaluated by MTT assay. Based on the chemical and biological activity results, the spectrum-effect relationship between the characteristic HPLC fingerprints and the hepatoprotective effect of TDL was established using Minitab 16.0 data analysis software. On the basis of the spectrum-effect relationship, thirteen compounds (1-13) were obtained from the TDL by chemical natural product chemical separation and purification technology, and their structures were identified on the basis of the spectral data and the literature. Based on these compounds, thirteen common peaks among the thirty-three chromatographic peaks in the above HPLC fingerprints were identified. Our findings showed that some components, including, schisandrin B (2), schisandrin A (3), and schisandrol B (7) had significant roles in promoting hepatoprotective activity. Preliminary verification of the spectrum-effect relationship of TDL from S. chinensis was carried out, and the results confirmed that the activity of a composite of these three key components in optimal ratios was better than that of any individual compound, which potentially confirmed the reliability of the spectrum-effect relationship and the synergistic effects of traditional Chinese medicine.

Dynamic changes in coagulation parameters and correlation with disease severity and mortality in patients with COVID-19.

OBJECTIVE: This study aimed to describe the dynamic changes of coagulation parameters and evaluate the relationship between longitudinal coagulation parameters abnormalities and prognosis of COVID-19 patients. METHODS: We performed a retrospective study of 1131 COVID-19 patients. Longitudinal coagulation parameters and clinical outcomes were analyzed. RESULTS: Abnormal coagulation parameters were observed in patients with COVID-19, both at hospital admission (INR 2.3%, PT 7.9%, APTT 15.4%, TT 0.9%, FDP 2.3%, D-dimer 19.7%) and peak hospitalization (INR 4.8%, PT 13.4%, APTT 25.6%, TT 2.7%, FDP 10.4%, D-dimer 31.5%). Compared with non-severe patients with COVID-19, severe patients had a slightly higher INR, PT, APTT, whereas remarkably higher FDP and D-dimer (p < 0.05). On multivariate analysis, age > 60 years, male, obesity, comorbidity, abnormal D-dimer on hospital admission, and abnormal peak hospitalization PT, APTT, FDP and D-dimer were associated with COVID-19 severity. The extreme coagulation parameters abnormalities (PT > 16s, FDP > 50 ug/ml, and D-dimer > 5 ug/ml) were associated with a significantly higher mortality. CONCLUSION: Longitudinal coagulation parameters abnormalities are common in patients with COVID-19, and associated with disease severity and mortality. Monitoring coagulation parameters is advisable to improve the management of patients with COVID-19.

A Novel Prediction Model for Long-Term SARS-CoV-2 RNA Shedding in Non-Severe Adult Hospitalized Patients with COVID-19: A Retrospective Cohort Study.

INTRODUCTION: Due to the lack of clear direction (evidence) on the duration of viral shedding and thus potential for transmission, this retrospective study aimed to come up with a prediction model of prolonged coronavirus disease-19 (COVID-19) transmission or infection-spreading potential. METHODS: A total of 1211 non-severe patients with COVID-19 were retrospectively enrolled. Multivariate Cox regression was performed to identify the risk factors associated with long-term SARS-CoV-2 RNA shedding, and a prediction model was established. RESULTS: In the training set, 796 patients were divided into the long-term (> 21 days) group (n = 116, 14.6%) and the short-term (≤ 21 days) group (n = 680, 85.4%) based on their viral shedding duration. Multivariate analysis identified that age > 50 years, comorbidity, CD4-positive T-lymphocytes count (CD4 + T cell) ≤ 410 cells/ul, C-reactive protein (CRP) > 10 mg/L, and the corticosteroid use were independent risk factors for long-term SARS-CoV-2 RNA shedding. Incorporating the five risk factors, a prediction model, named as the CCCCA score, was established, and its area under the receiver operator characteristic curve (AUROC) was 0.87 in the training set and 0.83 in the validation set, respectively. In the validation set, using a cut-off of 8 points, we found sensitivity, specificity, positive predictive value, and negative predictive value of 51.7%, 92.2%, 33.3%, and 96.2%, respectively. Long-term SARS-CoV-2 RNA shedding increased from 14/370 (3.8%) in patients with CCCCA < 8 points to 15/45 (33.3%) in patients with CCCCA ≥ 8 points. CONCLUSION: Using the CCCCA score, clinicians can identify patients with long-term SARS-CoV-2 RNA shedding.

[Role of bone morphogenetic protein 1/tolloid proteinase family in the development of teeth and bone].

The bone morphogenetic protein (BMP) 1/tolloid (TLD) proteinase family is a group of important metalloproteinases, which play key roles in the growth and development of tissues and organs via regulating the biosynthetic processing of the extracellular matrix. Clinical reports have revealed that mutations in the genes encoding BMP1/TLD proteinases lead to dentinogenesis imperfecta type Ⅰ, accompanied with osteogenesis imperfecta. Therefore, this proteinase family is essential for the development of hard tissues. In this study, we review the research progress in the function and mechanism of the BMP1/TLD proteinase family in the development of teeth and bone.

[Temporal and spatial distribution of Gli1+ cells and their function during periodontal development].

OBJECTIVE: This study aimed to investigate the distribution of Gli1+ cells in the periodontal ligament (PDL) and to evaluate their contribution in the development of periodontal tissue by using transgenic mouse lines. METHODS: Gli1lacZ/+ mice were harvested at different ages (3, 6, and 8 weeks), and the temporal and spatial distribution patterns of Gli1+ PDL cells were revealed by X-gal staining. Afterward, 3-week-old Gli1-CreERT2/+;R26RtdTomato/+ mice were administered with tamoxifen, and the fates of Gli1+ cells and their descendants were traced during periodontal development. RESULTS: A large number of Gli1+ cells were detected in the PDL of the 3-week-old mice; however, their number significantly decreased from 3 weeks to 8 weeks (P<0.05). Cell lineage tracing data showed that the descendants of Gli1+ cells dramatically increased from 3 weeks to 8 weeks (P<0.05) and gradually differentiated into fibroblasts, cementocytes, and osteocytes. CONCLUSIONS: The multi-differentiation potential of Gli1+ PDL cells was revealed, indicating that Gli1+ cells are an important cell source for periodontal development.

Prevalence and Years Lived with Disability for Dental Caries among Children Aged 0-14 Years in China, 1990-2016.

The estimate of dental caries among Chinese children at the microscale level using standard methodology remains unclear. In this study, we assessed and analyzed the disease burden of childhood dental caries in China by extracting data from the Global Burden of Disease, Injuries, and Risk Factors Study 2016 (GBD 2016). In 2016, the number of cases, prevalence, years lived with disability (YLD), and age-standardized YLD rate of dental caries was 93.0 million, 43.0%, 32,200 person years, and 14.8 per 100,000, respectively. Across 33 provincial units, the disease burden was highest in Hubei (YLD rate 28.6 per 100,000), lowest in Macao (9.1 per 100,000), while geographical clustering was not observed. Compared with 1990, the prevalence in 2016 decreased from 46.8% to 43.0%, and the YLD rate decreased from 16.5 per 100,000 to 14.8 per 100,000. Given the slight decrease in dental caries burden, the prevalence and disease burden remained high among Chinese children. Strategies for addressing the spatial inequity of childhood dental caries require geographical targeting.

α-adrenoceptor-mediated enhanced inducibility of atrial fibrillation in a canine system inflammation model.

The exact mechanism associated with inflammation and atrial fibrillation (AF) remains unknown. The aim of the present study was to investigate the roles of connexin 43 (Cx43) and a1­adrenergic receptor (α1­AR) activation in the pathogenesis of system inflammation­induced AF. A canine model of chronic low­grade system inflammation was established by administrating a low dose of lipopolysaccharide (LPS; 0.1 µg/kg) for 2 weeks. Programmed stimulation was applied on the right atrial appendage to determine the effective refractory periods (ERP) and the window of vulnerability (WOV). Tumor necrosis factor α (TNF­α) and interleukin 6 (IL­6) levels in plasma and atrial tissue were measured by ELISA. Cx43, Toll­like receptor 4 (TLR4) and nuclear factor κB (NF­κB) proteins were analyzed using western blotting or immunohistochemistry. Administration of LPS for 2 weeks increased the concentration of TNF­α and IL­6 in the plasma and right atrium. ERP was markedly shortened and cumulative WOV was significantly widened in the LPS group. Following treatment with LPS, the amount of Cx43 protein in the area of intercalated disk increased. In addition, a high­density of Cx43 in the lateral connection was identified. LPS also induced the activation of NF­κB in the canine atrium. Administration with the α1­AR blocker doxazosin prevented the production of LPS­induced inflammatory cytokine and reversed the enhanced vulnerability to atrial fibrillation. Doxazosin inhibited the LPS­induced increase in Cx43 protein and heterogeneous distribution, and prevented the activation of NF­κB. These results indicated that chronic low­grade system inflammation may increase the inducibility of AF in a canine model. The underlying mechanism may be involved in the LPS­induced activation of NF­κB, and the increase in Cx43 expression and lateral distribution via an α1-AR-dependent pathway.

c-Met identifies a population of matrix metalloproteinase 9-producing monocytes in peritumoural stroma of hepatocellular carcinoma.

Macrophages (Mϕ) are prominent components of solid tumours and exhibit distinct phenotypes in different microenvironments. Previously, we found that tumours could alter the normal developmental process of Mϕ to trigger transient activation of monocytes in the peritumoural stroma of human hepatocellular carcinoma (HCC). In the present study, we showed that a fraction of monocytes in the peritumoural stroma, but not in HCC cancer nests, expressed surface c-Met molecules. Monocytes exposed to tumours strongly expressed c-Met proteins with kinetics similar to their activation status, and significant correlations were found between c-Met levels and HLA-DR expression on tumour-infiltrating monocytes. NF-κB-mediated autocrine TNF-α stimulated the expression of c-Met on activated monocytes, and by interacting with its ligand hepatocyte growth factor (HGF), c-Met increased the motility and matrix metalloproteinase (MMP) 9-producing capacity of tumour-associated monocytes. The intensity of c-Met expression on tumour-infiltrating monocytes was associated with high mortality and reduced survival of patients with HCC. Therefore, the expression of c-Met on activated monocytes/Mϕ may represent a novel mechanism by which a tumour actively and precisely regulates the distribution and functions of these cells to facilitate disease progression.

A quantitative study of MC3T3-E1 cell adhesion, morphology and biomechanics on chitosan-collagen blend films at single cell level.

The interaction between cells and biomaterials plays a key role in cell proliferation and differentiation in tissue engineering. However, a quantitative analysis of those interactions has been less well studied. The objective of this study was to quantitative recapitulate the difference of MC3T3-E1 cell adhesion, morphological and biomechanical properties on chitosan-collagen films in terms of chemical composition. Here, the unbinding force between MC3T3-E1 cell and a series of chitosan-collagen films was probed by a real-time and in situ atomic force microscopy-single cell force spectroscopy (AFM-SCFS). Meanwhile, changes in cell morphology and Young's modulus on different chitosan-collagen films were detected by AFM. The cell area and CCK-8 results showed that cell spreading and proliferation increased with increasing collagen content. AFM observations clearly showed cell height decreased and pseudopod fusion with the collagen content increased. Cell adhesive force increased from 0.76±0.17 nN to 1.70±0.19 nN. On the contrary, cells Young's modulus, which reflected biophysical changes of cells decreased from 11.94±3.19 kPa to 1.81±0.52 kPa, respectively. It suggested that stronger cell-substrate interactions benefit cell adhesion, and better cell flexibility improve cell spreading. The findings indicate that cell morphology, adhesive force and Young's modulus are significant affected by various chitosan-collagen substrates. Those methods and quantitative results have guiding significance for investigating the mechanism of chitosan and/or collagen based cell-targeting drug carrier and the preparation of chitosan-collagen composite biomaterials.

Senescent endothelial progenitor cells from dogs with pulmonary arterial hypertension: a before-after self-controlled study.

Previous studies have underlined the importance of endothelial dysfunction and microvascular occlusion in the pathogenesis of pulmonary artery hypertension (PAH). Since the endothelial progenitor cells (EPCs) are involved in maintaining endothelial homeostasis, we observed the change of peripheral EPCs in canines before and after PAH onset. PAH was induced by intra-pulmonary artery injection of dehydromonocrotaline (DHMC) in nine beagles. Before and 48 h and 6 weeks after DHMC injection, 40 ml peripheral blood was obtained from the femoral vein. Circulating EPCs were identified as CD133 + KDR + cells and numerated by fluorescence-activated cell sorter; the EPCs functional capacity was determined by in vitro tubule-forming assay. The senescence of EPCs was determined by beta-galactosidase staining. At each time point, 2 ml blood from femoral artery was obtained for arterial oxygen pressure (PaO(2)). Forty-eight hours after DHMC injection, treated beagles suffered from hypoxemia; however, both the number and the tubule-forming capacity of EPCs were transiently raised. Six weeks later, PAH was confirmed by obviously high mean pulmonary arterial pressure (20.2 +/- 1.64 vs. 11.3 +/- 2.0 mmHg, p < 0.05) and low PaO(2) (69.30 +/- 9.15 vs. 95.94 +/- 1.43 mmHg, p < 0.01) in beagles after DHMC treatment, and their EPCs exhibited a predominant decrease in either the number (206.1 +/- 26.8 vs. 632.8 +/- 42.8 cells/ml blood, p < 0.01) or the tubule-forming capacity (21.1 +/- 2.8 vs. 11.2 +/- 2.8 tubules/x200 field, p < 0.01). Additionally, senescence-associated beta-galactosidase-positive EPCs were significantly increased. Our data suggested that, after the acute stage of DHMC injury to pulmonary vessels, the EPCs from PAH beagles suffered from exhaustion and senescence.

[Emission spectrum analysis of laser ablation on the silicon surface].

The free electron density and temperature of laser-induced plasma and the damage on the silicon surface were investigated. The results show that the volume and the free electron density of laser induced plasma, as well as the plasma temperature will determine the profile and the size of silicon superficial damage. It was also found that the volume of laser plasma will increase continuously and the temperature will increase slightly with the increase in the energy of laser pulse, while the density of free electrons will remain invariable. The free electron density and the temperature reduce gradually from centre to edge, so the damage appearance has the following features: The interior area of damage was melted so well that the periodic stripes were formed. The periodic stripes were quite irregular for the area not melted very well. The boundary of damage is apparent and sometimes color changes induced by plasma spattering were observed.

[Effects of angiotensin converting enzyme inhibitor on the expression of angiotensin converting enzyme 2 in atrium of patients with atrial fibrillation].

OBJECTIVE: To investigate the expression of angiotensin converting enzyme 2 (ACE2) and the changes treated with angiotensin converting enzyme inhibitor (ACEI), and its signal transduction pathway. METHODS: Atrial tissues were obtained from 47 patients with RHD undergoing cardiac surgery. The mRNA of ACE2 and ACE were semi-qualified by RT-PCR and normalized to the gene beta-actin. Western blot analysis was employed to examine the expressions of ACE2, ACE, ERK1/2 and phosphorylated ERK (pERK1/2). The atrial tissue angiotensin II (Ang II) content was determined by radioimmunoassay detection. RESULTS: The expression of ACE2 was significantly decreased (P < 0.05), the expression of ACE and pERK1/2 were significantly increased (P < 0.05), and the level of atrial tissue Ang II was significantly increased in patients with chronic atrial fibrillation group (CAF) compared with sinus rhythm group (SR) (P < 0.05). Compared with CAF patients treated without ACEI, the expression of ACE2 significantly increased (P < 0.01), and the relative activity of ERK1/2 significantly decreased (P < 0.05), whereas the expression of ACE and the level of atrial tissue Ang II remained unchanged in CAF patients treated with ACEI. CONCLUSIONS: The study suggested that the dysequilibrium of ACE/ACE2 might play an important role in the process of atrial fibrillation, which may be related to the activation of ERK1/2 pathway. The clinical effect of long-term treatment of ACEI maybe associated with elevated ACE2 expression but not ACE expression.

Transplantation of autologous endothelial progenitor cells may be beneficial in patients with idiopathic pulmonary arterial hypertension: a pilot randomized controlled trial.

OBJECTIVES: The goal of this study was to investigate the feasibility, safety, and initial clinical outcome of intravenous infusion of autologous endothelial progenitor cells (EPCs) in patients with idiopathic pulmonary arterial hypertension (IPAH). BACKGROUND: Experimental data suggest that transplantation of EPCs attenuates monocrotaline-induced pulmonary hypertension in rats and dogs. In addition, clinical studies suggest that autologous progenitor cell transplantation is feasible and safe in patients with ischemic diseases. METHODS: We conducted a prospective, randomized trial comparing the effects of EPC transplantation plus conventional therapy with those of conventional therapy alone in patients with IPAH. The primary end point was change in the 6-min walk distance using a standardized protocol. The secondary end points were changes in hemodynamic variables as assessed by right heart catheterization. RESULTS: After 12 weeks of follow-up, the mean distance walked in 6 min increased by 48.2 m in the cell infusion group (from 263 +/- 42 m to 312 +/- 34 m), and an increase of 5.7 m occurred in the conventional therapy group (from 264 +/- 42 m to 270 +/- 44 m). The mean difference between the 2 groups was 42.5 m (95% confidence interval 28.7 to 56.3 m, p < 0.001). The patients in the cell infusion group also had significant improvement in mean pulmonary artery pressure, pulmonary vascular resistance, and cardiac output. There were no severe adverse events with cell infusion. CONCLUSIONS: This preliminary study showed that intravenous infusion of autologous EPCs seemed to be feasible and safe, and might have beneficial effects on exercise capacity and pulmonary hemodynamics in patients with IPAH. (Safety and Efficacy Study of Transplantation of EPCs to Treat Idiopathic Pulmonary Arterial Hypertension; http://www.clinicaltrials.gov/ct/show/NCT00257413?order=1; NCT00257413).

Effects of aspirin on number, activity and inducible nitric oxide synthase of endothelial progenitor cells from peripheral blood.

AIM: To investigate whether aspirin has an influence on endothelial progenitor cells (EPC). METHODS: Total mononuclear cells (MNC) were isolated from peripheral blood by Ficoll density gradient centrifugation, then cells were plated on fibronectin-coated culture dishes. After 7 d of culture, attached cells were stimulated with aspirin (to achieve final concentrations of 1, 2, 5, and 10 mmol/L) for 3, 6, 12, and 24 h. EPC were characterized as adherent cells that were double positive for 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine low density lipoprotein (DiLDL) uptake and lectin binding by direct fluorescent staining. EPC proliferation and migration were assayed using a 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and a modified Boyden chamber assay, respectively. An EPC adhesion assay was performed by replating the EPC on fibronectin-coated dishes, and then adherent cells were counted. In vitro vasculogenesis activity was assayed by using an in vitro vasculogenesis kit. Inducible nitric oxide synthase (iNOS) was assayed by Western blotting. RESULTS: Incubation of isolated human MNC with aspirin decreased the number of EPC. Aspirin also decreased the proliferative, migratory, adhesive, and in vitro vasculogenesis capacity of EPC, and also their iNOS levels in a concentration- and time-dependent manner. CONCLUSION: Aspirin decreases (1) the number of EPC; (2) the proliferative, migratory, adhesive and in vitro vasculogenesis capacities of EPC; and (3) iNOS levels in EPC.

A novel splice mutation of HERG in a Chinese family with long QT syndrome.

Congenital long QT syndrome (LQTS) is a genetically heterogeneous disease in which six ion-channel genes have been identified. The phenotype-genotype relationships of the HERG (human ether-a-go-go-related gene) mutations are not fully understood. The objective of this study is to identify the underlying genetic basis of a Chinese family with LQTS and to characterize the clinical manifestations properties of the mutation. Single strand conformation polymorphism (SSCP) analyses were conducted on DNA fragments amplified by polymerase chain reaction from five LQT-related genes. Aberrant conformers were analyzed by DNA sequencing. A novel splice mutation in C-terminus of HERG was identified in this Chinese LQTS family, leading to the deletion of 11-bp at the acceptor splice site of Exon9 [Exon9 IVS del (-12-->-2)]. The mutation might affect, through deficient splicing, the putative cyclic nucleotide binding domain (CNBD) of the HERG K(+) channel. This mutation resulted in a mildly affected phenotype. Only the proband had a history of syncopes, while the other three individuals with long QT interval had no symptoms. Two other mutation carriers displayed normal phenotype. No sudden death occurred in the family. The 4 affected individuals and the two silent mutation carriers were all heterozygous for the mutation. It is the first splice mutation of HERG reported in Chinese LQTS families. Clinical data suggest that the CNBD mutation may be less malignant than mutations occurring in the pore region and be partially dominant over wild-type function.

[Changes of endothelial progenitor cells from peripheral blood in patients with coronary heart diseases].

OBJECTIVE: To investigate alterations of endothelial progenitor cells (EPCs) from peripheral blood in patients with coronary heart diseases. METHODS: Twenty patients with coronary heart diseases (CHD) and 20 matched control subjects were included in the study. Total mononuclear cells (MNCs) were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After cultured for 7 days, attached cells were cytochemically analyzed. EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin-binding by laser scanning confocal microscope with direct fluorescent staining. EPCs proliferation and migration were measured by MTT assay and modified Boyden chamber assay, respectively. EPCs adhesion assay was performed by replating on fibronectin-coated dishes, then adherent cells were counted. RESULTS: The number of EPCs was significantly reduced in patients with CHD compared with that of age-matched control subjects (31.8+/-7.7 compared with 59.5 +/-10.6 EPCs/x 200 field; P<0.05). In addition, the functional activity of EPCs such as proliferation, migration and adhesive capacity was also impaired in patients with CHD. CONCLUSION: EPCs number and functional activity are significantly decreased in patients with CHD.

[Cloning, expression and sequence analysis and tissue distribution of angiotensin-converting enzyme 2 (ACE2) gene in adult mice].

OBJECTIVE: o clone angiotensin-converting enzyme 2(ACE2) gene, to analyze its amino acids and nucleotides sequence and to investigate tissue distribution of ACE2 in adult mice. METHODS: The full-length ACE2 encoding sequence was amplified from the RNA of mice kidney tissue by RT-PCR technique, cloned into plasmid pGEM-T easy, then subcloned into plasmid pcDNA3.1+. After identification of DNA sequence, the recombinant plasmid pmACE2 was transfected into Cos7 cells with lipofectin reagent. The transient expression of ACE2 molecule was detected by SDS-PAGE. Sequence analysis was conducted with CLUSTALX program. Tissue distribution of ACE2 in mice was detected by RT-PCR. RESULTS: A fragment about 2.6 kb was amplified and the recombinant plasmid pmACE2 was confirmed by two-enzyme digesting and DNA sequencing. The cloned DNA sequence was consistent with that previously reported, except for 3 variations: A701G, T1102C and T1330C. SDS-PAGE proved that expression of a soluble, truncated products form of ACE2 was a glycoprotein of approximately 80 kD in Cos7 cells. The predicted mice ACE2 sequence contained an N-terminal signal sequence (amino acid residues 1-18), a single HHEMGHIQ zinc-binding domain (amino acid residues 373-380) and C-terminal membrane anchor (amino acid residues 738-765). Mice ACE2 showed 84 % identity with that of human, and 90 % identity with that of rat. Expression of ACE2 was the greatest in lungs, hearts and kidneys, and moderate levels were also detected in testes and livers. CONCLUSION: Mice ACE2 gene has been cloned and successfully expressed in vitro. The tissue-specific expression of ACE2 in different species is not identical.

Single nucleotide polymorphisms of the SCN5A gene in Han Chinese and their relation with Brugada syndrome.

BACKGROUND: Mutations in the cardiac sodium channel gene (SCN5A) may lead to a broad spectrum of familial arrhythmias, including long QT syndrome (LQTS), idiopathic ventricular fibrillation (IVF), and isolated cardiac conduction diseases. Recent studies have shown that polymorphisms in the SCN5A gene also play an important role in the manifestation of disorders involving cardiac excitability. In this study, we investigated the polymorphisms of the SCN5A gene in Han Chinese and its relation to Brugada syndrome (BS). METHODS: Genomic DNA was isolated from 120 unrelated healthy volunteers and 48 unrelated Brugada syndrome patients by means of standard procedures. All exons including the putative splicing sites of the SCN5A gene were amplified by PCR and sequenced directly or after subcloning using an ABI Prism 377 DNA sequencer. RESULTS: A total of 5 single nucleotide polymorphisms (SNPs) were identified in the Han Chinese population, including 3 novel ones: G87A(A29A), 4245 + 82A > G, and G6174A. The allele frequencies of each SNP in the Han Chinese population were as follows: G87A (A29A) 27.5%, A1673G (H558R) 10.4%, 4245 + 82A > G 32.8%, C5457T (D1819D) 41.3%, and G6174A 44.9%. S1102Y and 10 other SNPs identified in other ethnic populations were not detected in this study. There was no significant difference in the allele frequency of A1673G (H558R) between different ethnic populations (all P > 0.5). On the other hand, the allele frequency of C5457T (D1819D) among Han Chinese was similar to its frequency among Japanese (P > 0.5), but higher than that among Americans (P < 0.005). The allele G1673 (R558) was over-represented in BS patients compared to controls (P < 0.005), but there was no significant difference in genotype frequencies at this locus. There were also no differences in either the allele or genotype frequencies of the 4 other identified SNPs when comparing BS patients with healthy controls. CONCLUSIONS: The distribution of SCN5A SNPs may vary between different ethnicities. The polymorphism of A1673G might be associated with BS and may contribute to a susceptibility to BS in Han Chinese.

[Single nucleotide polymorphism in SCN5A and the distribution in Chinese Han ethnic group].

Mutations in voltage-gated sodium channel type (SCN5A) may evoke severe, life-threatening disturbances in cardiac rhythm, including long QT syndrome, idiopathic ventricular fibrillation (Brugada Syndrome), and isolated cardiac conduction disease. There is increasing awareness of the role of common polymorphisms in altering gene function and in susceptibility to diseases. The aim of the present study was to investigate single nucleotide polymorphism (SNP) in SCN5A gene and the distribution of these identified SNPs in Chinese Han nationality. SCN5A gene was sequenced by fluorescent labeling automatic sequencing method in 120 unrelated samples from Han nationality in South China. Allele frequency distribution was tested by Hardy-Weinberg equilibrium. The results showed that a total of 5 SNPs were identified in SCN5A gene, including three SNPs in code region, one SNP in regulatory region and the other in intron 23 adjacent to donor splicing site. The distribution of the SNPs in SCN5A gene was uneven. These allele frequencies in Han population of South China were as follows: G87A (A29A) 27.5%, A1673G (H588R) 10.4%, 4245+82A>G 32.8%, C5457T (D1819D) 41.3% and G6174A 44.9% respectively. The SNPs G87A (A29A), 4245+82A>G and G6174A were reported for the first time. There was no significant difference in the allele frequency of A1673G (H558R) within different ethical populations (P>0.05). C5457T (D1819D) allele frequency of Han population in South China was similar to that observed in Japanese (P>0.5), but higher than that in American (p<0.005). There was no significant difference in the distribution of the SNPs between male group and female group (all p>0.05). S1102Y and other 10 SNPs identified in other ethnic populations have not been detected in Chinese Han population. The allele distribution of SNPs was in good unity with the Hardy-Weinberg equilibrium. It is suggested that the SNP distribution of SCN5A gene varies within different nationalities. These data will be of use for genetic association studies of acquired arrythmias and investigation of sensitivity to drug therapy.