Mutations in the perform gene in children with hemophagocytic lymphohistiocytosis

Background Recent studies have reported germline mutations in the perforin gene (PRF1) in some types of hemophagocytic lymphohistiocytosis (HLH). However, the prevalence of PRF1 mutations in HLH in Chinese pediatric patients has not been extensively studied. The aim of this study was to investigate the prevalence of mutations and sequence variations in the PRF1 gene in Chinese pediatric patients with HLH.Methods Polymerase chain reaction (PCR) was performed with five pairs of primers for the coding exons and the flanking intron sequences of PRF1. Sequencing of PCR products was subsequently applied in 30 pediatric patients with HLH and in 50 controls.Results Three heterozygous mutations in a coding region were found, which resulted in amino acid changes (C102F, S108N and T450M) in three patients. These mutations were not detected in control subjects. One patient had compound heterozygous mutations (S108N and T450M) in PRF1 as the background defect, and documented familial HLH type 2 (FHL2). One synonymous sequence variant (Q540Q) was observed in one patient but not in the controls. Two SNPs (A274A, H300H) in the coding region were detected in HLH patients and controls, but without differences in the heterozygosity rate between the two groups (P＞0.05 for all comparisons).Conclusions We have identified three patients with three heterozygous missense mutations in PRF1; two of those three mutations (C102F and S108N) have so far been found only from Chinese patients. These findings are useful in evaluating the prevalence of PRF1 mutations in Chinese pediatric patients with HLH, and to correlate their genotype with phenotype. Some patients without familial history probably have primary HLH, which should be suspected even beyond the usual age range.     

Compound mutations (R237X and L375P) in the fumarylacetoacetate hydrolase gene causing tyrosinemia type I in a Chinese patient

Background  Mutations in fumarylacetoacetate hydrolase (FAH) gene can lead to tyrosinemia type 1 (HT1), a relatively rare autosomal recessive disorder. To date, no molecular genetic defects of HT1 in China have been described. We investigated a Chinese family with a HT1 child to identify mutations in FAH.

Methods  DNA sequencing was used for mutations screening in FAH gene. Real-time polymerase chain reaction (PCR) was performed to determine the FAH gene expression level. To confirm the presence of degradation by the nonsense-mediated mRNA decay pathway (NMD), the fragments containing R237X mutations were analyzed by primer introduced restriction analysis-polymerase chain reaction (PIRA-PCR) and cDNA sequencing. Finally, the effects of the mutations reported in this study were predicted by online softwares.

Results  A boy aged 3 years and 8 months was diagnosed clinically with HT1 based on his manifestations and biochemical abnormalities. Screening of FAH gene revealed two heterozygous mutations R237X and L375P transmitted from his mother and father respectively. In this pedigree, the amount of FAH mRNA relative to a healthy control was 0.44 for the patient, 0.77 for his mother and 1.07 for his father. Moreover, both PIRA-PCR and cDNA sequencing showed significant reduction of the FAH mRNA with R237X nonsense mutation. The missense mutation of L375P was not reported previously and prediction software showed that this mutation decreased the stability of protein structure and affected protein function.

Conclusions  This is the first case of HT1 analyzed by molecular genetics in China. The R237X mutation in FAH down- regulates the FAH gene expression, and the L375P mutation perhaps interrupts the secondary structure of FAH protein.

     

Association of NFATc1 gene polymorphism with ventricular septal defect in the Chinese Han population

Background Congenital heart disease (CHD) is a diverse group of diseases determined by genetic and environmental factors.Considerable research has been done on genes associated with the development of ...     

Exome sequencing identifies compound heterozygous PKHD1 mutations as a cause of autosomal recessive polycystic kidney disease

Background  Autosomal recessive polycystic kidney disease (ARPKD) is a rare inherited disease, which is a disorder with multiple organ involvement, mainly the kidney and liver. It is caused by mutations in the PKHD1 gene. Here, we reported the clinical characteristics of a case with ARPKD and analyze the genetic features of this patient as well as of his father using targeted exome sequencing and Sanger sequencing.

Methods  Genomic DNA was extracted from peripheral blood leukocytes obtained from a patient with ARPKD. The mutations were identified using exome sequencing and confirmed by Sanger sequencing.

Results  The patient was diagnosed as ARPKD based on ultrasonography and abdominal computed tomography which showed polycystic changes, multiple calcinosis of both kidneys, and multiple dilated bile ducts of the liver. Compound heterozygous PKHD1 gene mutations A979G and G5935A, which lead to substitution of an asparagine for an aspartate at amino acid 327 (N327D) and a glycine for an arginine at amino acid 1979 (G1979R) respectively, were identified using targeted exome sequencing and confirmed by Sanger sequencing for the patient. In addition, the father of the patient was identified to be a carrier of heterozygous A979G mutation of this gene.

Conclusions  We identified that the compound heterozygous PKHD1 gene mutations are the molecular basis of the patient with ARPKD. Targeted exome sequencing is suitable for genetic diagnosis of single-gene inherited diseases like ARPKD in which the pathogenic gene is a large.     

Evaluation of global and regional left ventricular systolic function in patients with frequent isolated premature ventricular complexes from the right ventricular outflow tract

Background  Frequent premature ventricular complexes from the right ventricular outflow tract (RVOT-PVCs) are associated with left ventricular dysfunction. This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.
Methods  This study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects. Aortic systolic velocity-time integral (AoVTI) and myocardium strain in circumferential (CS), radial (RS) and longitudinal (LS) directions were evaluated by conventional echocardiography and speckle tracking imaging. All values of patients with RVOT-PVCs were recorded during sinus (PVC-S) and PVC beats (PVC-V).
Results  Significant differences were demonstrated in global CS, RS and LS between the control subjects and the PVC-V (CS: (17.46±2.48)% vs. (11.52±3.28)%, RS: (48.26±10.20)% vs. (20.92±9.78)%, LS: (19.89±2.62)% vs. (11.79±3.66)%, P <0.01), and in segmental RS and LS of nearly all the left ventricular segments. Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior, anteroseptal and septal segments (only seen in anteroseptal and septal segments at apex). Furthermore, V/S AoVTI (AoVTI during the PVC beat divided by AoVTI during the sinus beat, then multiplied by 100%) correlated with coupling interval (r=0.67, P <0.001) and global strain (CS: r=0.48, P=0.007; RS: r=0.65, P <0.001; LS: r=0.65, P <0.001).
Conclusions  Frequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction. The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.

     

Genetic characterization of a Chinese family with familial idiopathic pulmonary fibrosis

Background  Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory interstitial lung disease with an unknown cause. Recent studies have shown that genetic factors play an important role in the pathogenesis of IPF.

Methods  To explore the genetic background of patients with IPF, a candidate gene approach was employed to screen for mutations in seven genes among members with familial IPF in mainland of China.

Results  Within six of the candidate genes, a total of 31 point mutations were identified. Among the missense mutations, the SFTPA1 exon 6 CAG>AAG (Gln238Lys) and SFTPB exon 2 CAC>CCC (His2Pro) mutations caused changes in the physical and chemical properties of amino acids. Each sequence alteration was identified in sporadic IPF patients, control specimens (pneumonia patients and healthy persons). Genotype frequencies and allele frequencies of codon 238 in exon 6 of SFTPA1 were noted significantly higher in patients with IPF than those in other two control subjects. The computational protein structure prediction by protein homology modeling confirmed differences in three-dimensional structure between mutant SFTPA1 and original SFTPA1.     

Conclusions  Although the functions of the mutant candidate genes vary, these genes may ultimately result in damage to alveolar epithelial cells, initiating the progress of pulmonary fibrosis. In particular, while pathophysiological mechanisms need to be illustrated, the Gln238Lys missense variant of exon 6 in the SFTPA1 may have potential susceptibility in the development of IPF, which was shown in patients with sporadic IPF with a statistically higher frequency.

     

Endoscopic thyroidectomy: an evidence-based research on feasibility, safety and clinical effectiveness

Background The feasibility and safety of endoscopic thyroidectomy were evaluated by an approach of systematic review of published studies in the past decade.
Methods A database searching was performed on MEDLINE, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials. Both comparative and non-comparative studies about endoscopic thyroidectomy were selected and analyzed. For the comparative studies, RevMan 4.2 was used for statistical analysis; and for the non-comparative studies, data analysis was performed by SPSS 13.0.
Results Seven comparative studies involving 367 patients （video-assisted thyroidectomy （VAT）, 174 patients; conventional thyroidectomy （CT）, 193 patients） were included in VAT-CT group. Age, gender, operative types, and pathological diagnosis were similar. Compared with CT, the mean operative time for VAT was significantly longer （VAT, 80.0 minutes; CT, 61.9 minutes, P 〈0.01）, but the postoperative hospital stay was shorter （VAT, 1.7 days; CT, 2.5 days, P 〈0.01）. The complication rate for VAT was 6.9%, while that for CT was 9.3% （P=0.35）. Three studies analyzed the postoperative pain and cosmetic evaluation, and indicated that the VAT group was superior to the CT group, but there was no significant difference after a meta-analysis. Three comparative studies involving 273 patients （totally endoscopic thyroidectomy （TET）, 145 patients; CT, 128 patients） were included in TET-CT group and the results generally resembled that of VAT-CT group. There were 18 and 14 non-comparative studies reporting the results of VAT and TET, respectively. The mean operative time for VAT was 76.8 minutes compared with 135.8 minutes for TET. The postoperative hospital stay was 1.8 and 3.8 days for VAT and TET respectively. The rates of conversion to open surgery for VAT and TET were similar （VAT, 2.8%; TET, 3.9%, P=0.105）. The complication rate for VAT was 8.     

Endothelial progenitor cell mediates transport of hepatitis B

Health authorities in Shanghai said yesterday that investigations have found no contamination at the city＇s umbilical cord blood bank and gave the assurance that supplies remain safe for use.     

Effects of cloned tumstatin-related and angiogenesis-inhibitory peptides on proliferation and apoptosis of endothelial cells

Background Tumstatin is a recently developed endogenous vascular endothelial growth inhibitor that can be applied as an anti-angiogenesis and antineoplastic agent. The study aimed to design and synthesize the small molecular angiogenesis inhibition-related peptide （peptide 21）, to replicate the structural and functional features of the active zone of angiogenesis inhibition using tumstatin and to prove that synthesized peptide 21 has a similar activity： specifically inhibiting tumor angiogenesis like tumstatin. Methods Peptide 21 was designed and synthesized using biological engineering technology. To determine its biological action, the human umbilical vein endothelial cell line ECV304, the human ovarian cancer cell line SKOV-3 and the mouse embryo-derived NIH3T3 fibroblasts were used in in vitro experiments to determine the effect of peptide 21 on proliferation of the three cell lines using the MTT test and growth curves. Transmission electron microscopy （TEM） and flow cytometry （FCM） were applied to analyze the peptide 21-induced apoptosis of the three cell lines qualitatively and quantitatively. In animal experiments, tumor models in nude mice subcutaneously grafted with SKOV-3 were used to observe the effects of peptide 21 on tumor weight, size and microvessel density （MVD）. To initially investigate the role of peptide 21, the effect of peptide 21 on the expression of vascular endothelial growth factors （VEGFs） by tumor tissue was semi-quantitatively analyzed. Results The in vitro Ml-r test and growth curves all indicated that cloned peptide 21 could specifically inhibit ECV304 proliferation in a dose-dependent manner （P 〈0.01）; TEM and FCM showed that peptide 21 could specifically induce ECV304 apoptosis （P 〈0.01）. Results of in vivo experiments showed that tumors in the peptide 21 group grew more slowly. The weight and size of the tumors after 21 days of treatment were smaller than those in the control group （P 〈0.05）, with a mean tumor inhibition rate of 67.86%; MVD     

Steady-state pharmacokinetics of zidovudine in Chinese HIV-infected patients

Background  The pharmacokinetics of zidovudine (AZT) are possibly influenced by weight, age, sex, liver and renal functions, severity of disease, and ethnicity. Currently, little information is available on the steady-state pharmacokinetics of AZT in Chinese HIV-infected patients. The current study aimed to characterize the steady-state pharmacokinetics of AZT in a Chinese set-up.

Methods  Eleven Chinese HIV-infected patients were involved in the steady-state pharmacokinetic study. In total, 300 mg of AZT, as a part of combination therapy, was given to patients, and serial blood samples were collected for 12 hours. The samples were measured by a high-performance liquid chromatography (HPLC) assay, and the results were analyzed by both the non-compartment model and the one-compartment model.

Results  The C_max of AZT in Chinese patients was higher than that in non-Asian patients. The half-life of AZT, analyzed by the non-compartment model (P=0.02), in male patients ((1.02±0.22) hours) was shorter than that of AZT in female patients ((1.55±0.29) hours). The AZT clearance, analyzed by the one-compartment model (P=0.045), in male patients ((262.60±28.13) L/h) was higher than that in female patients ((195.85±60.51) L/h).

Conclusion  The present study provides valuable information for the clinical practice of AZT-based highly active antiretroviral therapy in a Chinese set-up.

     

Indoor mite allergen levels, specific IgE prevalence and IgE cross-inhibition pattern among asthmatic children in Haikou, southern China

Background  Haikou locates in tropical island with unique mite propagation. The aim of this stuy is to determine mite allergens levels in Haikou, and to investigate the prevalence of mite specific IgE-sensitization and IgE cross-reactivity between house dust mites. 

Methods  Allergen and antigen concentrations against six mite species were tested by enzyme-linked immunosorbent assay (ELISA). Specific IgE concentrations and cross-inhibitions were measured with ADVIA Centaur^®.

Results  Allergen or antigen Dermatophagoides pteronyssinus (Der p 1), Blomia tropicalis (Blo t ) and Tyrophagus putrescentia (Tyr p) were detected in dust samples. Dermatophagoides farinae (Der f 1), Lepidoglyphus destructor (Lep d 2), and Acarus siro (Aca s ) were found in very few samples. Specific IgE tests showed high prevalence of sensitizations against all tested mites with high IgE levels to Der p, Der f, and Blo t. Storage mites, Blo t, Tyr p, Lep d, and Aca s, could inhibit Der p from 0 to 50%. Storage mites could inhibit Der f between 30% and 100%. Der p IgE could be inhibited by Der f with up to 90%, and vice versa. Der p could inhibit Blo t from 40% to 80%. Blo t was able to fully inhibit IgE binding to Lep d, Tyr p, and Aca s compared to partial inhibition by Der p.

Conclusions  Der p is the dominating mite and has the highest specific IgE prevalence among asthmatic children. Blo t represents an important source of storage mite sensitization and some patients may be independently sensitized to both Der p and Blo t. High prevalence of sensitization to Der f may be due to IgE-mediated cross-reactivity with Der p and Blo t.

     

Downregulating activated epidermal growth factor receptor has no effect on RBM5 expression

Background  We were interested in determining how the tumor suppressor gene RBM5 is regulated in lung cancers. Previous studies suggested that the gene expression is related to histological subtype and smoking exposure, since in small cell lung cancers the RBM5 gene is deleted whereas in non-small cell lung carcinomas (NSCLC) RBM5 expression is reduced. Of particular interest was the recent finding that in lung adenocarcinomas, a histological subtype of NSCLC, smoking exposure correlated with mutational activity in the transforming growth factor alpha (TGF-a) signaling pathway. Lung adenocarcinomas from smokers were associated with activating KRAS mutations, whereas lung adenocarcinomas from never-smokers were associated with activating epidermal growth factor receptor (EGFR) mutations. We hypothesized that inhibition of RBM5 in lung adenocarcinomas is achieved indirectly via these activating mutations. The objective of the research described herein was to determine if EGFR activation and RBM5 expression are negatively correlated.

Methods  EGFR expression in the lung adenocarcinoma cell line NCI-H1975 was inhibited using small interfering RNA. RBM5 expression was examined by real-time quantitative polymerase chain reaction and Western blotting.

Results  Reduced EGFR expression did not correlate with any change in RBM5 expression at either the RNA or protein level.

Conclusion  These results suggest that RBM5 expression is not directly regulated by EGFR in non-smoker related lung adenocarinomas, and that some other mechanism operates to inhibit either the expression or function of this potential tumour suppressor in lung cancers that retain the RBM5 gene.

     

Frequency of Breast Cancer Attributable to BRCA1 in a Population-Based Series of American Women

Context.— Previous studies of BRCA1 mutation prevalence have been based on high-risk groups, yielding estimates that do not reflect the experience of the general population of US patients with breast cancer. Objective.— To determine prevalence of known disease-related mutations and other variants in BRCA1 and how it differs by race, age at diagnosis, and family history status in a population-based sample of white and black patients with breast cancer unselected for family history. Design.— Case-control study. Setting.— A 24-county area of central and eastern North Carolina. Participants.— Cases were women aged 20 to 74 years diagnosed as having a first invasive breast cancer between May 1993 and June 1996. Controls were frequency matched to cases by 5-year age range and race. The first 211 cases and 188 controls regardless of race and the subsequent 99 cases and 108 controls of African American ancestry are included in this report. Main Outcome Measure.— Germline variants at any site in the coding sequence, splice junctions, 5' untranslated region, or 3' untranslated region of the BRCA1 gene were analyzed in cases, and selected variants were analyzed in controls. Screening was performed using multiplex single-strand conformation analysis, with all potential variants confirmed using genomic sequencing. Results.— Three of 211 patients with breast cancer had disease-related variants at BRCA1, all of which were protein-truncating mutations. After adjustment for sampling probabilities, the proportion of patients with breast cancer with disease-related variants was 3.3% (95% confidence interval, 0%-7.2%) in white women and 0% in black women. Young age at diagnosis alone did not predict BRCA1 carrier status in this population. In white women, prevalence of inherited mutation was 23% for cases with family history of ovarian cancer, 13% for cases from families with at least 4 cases of breast cancer with or without ovarian cancer, and 33% for cases from families with both breast and ovarian cancer and at least 4 affected relatives. Because these results are based on few families at the highest levels of risk, confidence intervals around these estimates are wide. An additional 5 patients had rare missense mutations or a single amino acid deletion, the biological significance of which is unknown. In black women, a variant in the 3' untranslated region was statistically significantly more common in cases than in controls. Conclusions.— These data suggest that in the general US population, widespread screening of BRCA1 is not warranted. In contrast, BRCA1 mutations are sufficiently frequent in families with both breast and ovarian cancer, or at least 4 cases of breast cancer (at any age), that genotyping might be considered. The emerging picture of BRCA1 population genetics involves complex interactions of family history, age, and genetic ancestry, all of which should be taken into account when considering testing or interpreting results.      

Prevalence and risk factors of chronic post-thoracotomy pain in Chinese patients from Peking Union Medical College Hospital

Background  In clinical practice, the mechanisms underlying chronic post-surgical pain (CPSP) remain insufficiently understood. The primary goals of this study were to determine the incidence of chronic pain after thoracic surgery and to identify possible risk factors associated with the development of chronic post-thoracotomy pain in Chinese patients. The secondary goal was to determine whether the difference between pre- and post-operative white blood cell (WBC) counts could predict the prevalence of CPSP after thoracotomy. The impact of chronic pain on daily life was also investigated.

Methods  We contacted by phone 607 patients who had undergone thoracotomy at our hospital during the period February 2009 to May 2010. Statistical comparisons were made between patients with or without CPSP.

Results  Results were ultimately analyzed from 466 qualified patients. The overall incidence of CPSP was 64.5%. Difference between pre- and post-operative WBC counts differed significantly between patients with or without CPSP (P <0.001) and was considered as an independent risk factor for the development of CPSP following thoracotomy (P <0.001). Other predictive factors for chronic pain included younger age (<60 years, P <0.001), diabetes mellitus (P=0.023), acute post-operative pain (P=0.005) and the duration of chest tube drainage (P <0.001). At the time of interviews, the pain resulted in at least moderate restriction of daily activities in 15% of the patients, of which only 16 patients had paid a visit to the doctor and only three of them were satisfied with the therapeutic effects.

Conclusions  Chronic pain is common after thoracotomy. WBC count may be a new independent risk factoring surgical patients during peri-operative period. Besides, age, diabetes mellitus, acute post-operative pain, and duration of chest tube drainage may also play a role in chronic post-surgical pain occurrence.

     

Genetic testing in the long QT syndrome: development and validation of an efficient approach to genotyping in clinical practice

Context  In long QT syndrome (LQTS), disease severity and response to therapy vary according to the genetic loci. There exists a critical need to devise strategies to expedite genetic analysis. Objective  To perform genetic screening in patients with LQTS to determine the yield of genetic testing, as well as the type and the prevalence of mutations. Design, Patients, and Setting  We investigated whether the detection of a set of frequently mutated codons in the KCNQ1, KCNH2, and SCN5A genes may translate in a novel strategy for rapid efficient genetic testing of 430 consecutive patients referred to our center between June 1996 and June 2004. The entire coding regions of KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 were screened by denaturing high-performance liquid chromatography and DNA sequencing. The frequency and the type of mutations were defined to identify a set of recurring mutations. A separate cohort of 75 consecutive probands was used as a validation group to quantify prospectively the prevalence of the recurring mutations identified in the primary LQTS population. Main Outcome Measures  Development of a novel approach to LQTS genotyping. Results  We identified 235 different mutations, 138 of which were novel, in 310 (72%) of 430 probands (49% KCNQ1, 39% KCNH2, 10% SCN5A, 1.7% KCNE1, and 0.7% KCNE2). Fifty-eight percent of probands carried nonprivate mutations in 64 codons of KCNQ1, KCNH2, and SCN5A genes. A similar occurrence of mutations at these codons (52%) was confirmed in the prospective cohort of 75 probands and in previously published LQTS cohorts. Conclusions  We have developed an approach to improve the efficiency of genetic screening for LQTS. This novel method may facilitate wider access to genotyping resulting in better risk stratification and treatment of LQTS patients.      

Prevalence of pathogenic BRCA1 mutation carriers in 5 US racial/ethnic groups

Esther M. John, PhD; Alexander Miron, PhD; Gail Gong, PhD; Amanda I. Phipps, MPH; Anna Felberg, MS; Frederick P. Li, MD; Dee W. West, PhD; Alice S. Whittemore, PhD

JAMA. 2007;298(24):2869-2876.

Context  Information on the prevalence of pathogenic BRCA1 mutation carriers in racial/ethnic minority populations is limited.

Objective  To estimate BRCA1 carrier prevalence in Hispanic, African American, and Asian American female breast cancer patients compared with non-Hispanic white patients with and without Ashkenazi Jewish ancestry.

Design, Setting, and Participants  We estimated race/ethnicity-specific prevalence of BRCA1 in a population-based, multiethnic series of female breast cancer patients younger than 65 years at diagnosis who were enrolled at the Northern California site of the Breast Cancer Family Registry during the period 1996-2005. Race/ethnicity and religious ancestry were based on self-report. Weighted estimates of prevalence and 95% confidence intervals (CIs) were based on Horvitz-Thompson estimating equations.

Main Outcome Measure  Estimates of BRCA1 prevalence.

Results  Estimates of BRCA1 prevalence were 3.5% (95% CI, 2.1%-5.8%) in Hispanic patients (n = 393), 1.3% (95% CI, 0.6%-2.6%) in African American patients (n = 341), and 0.5% (95% CI, 0.1%-2.0%) in Asian American patients (n = 444), compared with 8.3% (95% CI, 3.1%-20.1%) in Ashkenazi Jewish patients (n = 41) and 2.2% (95% CI, 0.7%-6.9%) in other non-Hispanic white patients (n = 508). Prevalence was particularly high in young (<35 years) African American patients (5/30 patients [16.7%]; 95% CI, 7.1%-34.3%). 185delAG was the most common mutation in Hispanics, found in 5 of 21 carriers (24%).

Conclusions  Among African American, Asian American, and Hispanic patients in the Northern California Breast Cancer Family Registry, the prevalence of BRCA1 mutation carriers was highest in Hispanics and lowest in Asian Americans. The higher carrier prevalence in Hispanics may reflect the presence of unrecognized Jewish ancestry in this population.

     

Randomized study on the safety and efficacy of dual-axis rotational versus standard coronary angiography in

Background  Dual-axis rotational coronary angiography (DARCA) was developed as an innovative adaptation of rotational angiography (RA), but it requires a longer coronary injection compared to standard coronary angiography (SA). As the body of the average Chinese patient is smaller than that of most western patients, with the same contrast injection time, the risk of complications from the contrast agent is increased in this population. The purpose of this study was to assess the clinical safety and efficacy of DARCA in the diagnosis of coronary artery disease (CAD) in the Chinese population by directly comparing it to SA.

Methods  Two hundred Chinese patients were randomized to either the SA group (n=100) or DARCA group (n=100). Contrast utilization, radiation exposure and procedure time were recorded for each modalities. Blood pressure (BP), heart rate (HR) pre and post injection symptoms and any arrhythmias were recorded.

Results  Compared to the SA group, there was a 42% reduction in contrast utilization, 55% reduction in radiation exposure and a 31% shorter procedure time in the DARCA group. In both groups, there were slight declines in the systolic BP values in the left coronary artery (LCA) post injection (P <0.01). Moreover, post injection HRs for the LCA were also reduced in the DARCA group (P <0.01). But all of these changes were small, transient and without clinical importance. Only one patient (1%) in the DARCA group had an attack of ventricular tachycardia immediately post injection and it resolved by itself during LCA angiography. No arrhythmias occurred in the SA group.

Conclusion  DARCA is a safe, efficient, and clinically comparable alternative to SA in the diagnosis of coronary artery disease in the Chinese population with less contrast utilized, which is less radiation exposure and a shorter procedure time than SA.

     

Transitional cell carcinoma associated with aristolochic acid nephropathy: most common cancer in chronic hemodialysis patients in China

Background  The research of cancer in patients on hemodialysis (HD) in China has not been reported. The aim of this study was to investigate the clinical and histological features and outcomes of cancer in Chinese HD patients.

Methods  The study subjects were 49 cancer patients (1.4%) out of 3448 end stage renal disease (ESRD) patients maintained on HD at China-Japan Friendship Hospital from October 1997 to July 2011.

Results  Urinary tract cancer (74%) was the most common followed by gastrointestinal tract cancer (12%), breast cancer (6%), lung cancer (4%), thyroid cancer (2%), and hematologic cancer (2%). Thirty-three patients (67%) had urinary tract transitional cell carcinoma (TCC) and 29 of them had aristolochic acid nephropathy (AAN) as underlying disease. Death occurred in eight patients out of 49, and the survival rate of HD patients with cancer was similar to those without cancer (P=0.120).

Conclusion  The urinary tract TCC is the most common cancer in HD patients with AAN in one of the centers of northern China.

     

A single tube modified allele-specific-PCR for rapid detection of erythromycin-resistant Mycoplasma pneumoniae in Beijing

Background  Mycoplasma pneumoniae (M. pneumoniae) is one of the common pathogens causing atypical pneumonia. In recent years, resistance to macrolides has become more common, especially in China. Previous studies have confirmed that the mutation at position 2063 in domain V of the 23S rRNA is the most prevalent, followed by the mutation at position 2064. Reported molecular detection methods for the identification of these mutations include direct sequencing, restriction fragment length polymorphism analysis, real-time polymerase chain reaction (PCR) with high-resolution melt analysis, and nested PCR-linked with capillary electrophoresis, etc. The most commonly used method for monitoring resistance-conferring mutations in M. pneumoniae is direct DNA sequencing of PCR or nested PCR products. However, these methods are time-consuming, labor-intensive or need expensive equipments. Therefore the development of rapid and sensitive methods is very important for monitoring the resistance globally.

Methods  In this study, we reported a fast and cost-effective method for detecting 2063 and/or 2064 macrolide resistant mutations from specimens using a modified allele-specific PCR analysis, and all results were compared with the sequencing data. We also analyzed the clinical courses of these samples to confirm the modified allele-specific PCR results.

Results  Among 97 M. pneumoniae specimens, 88 were found to possess mutations by this method, and all modified allele-specific PCR analysis results were consistent with the sequencing data. The data of the clinical courses of these 97 cases showed that they suffered from severe pneumonia. Erythromycin showed better efficacy on cases from which no macrolide resistance mutation was found on their specimens. However, in some cases from which mutations were detected, erythromycin monotherapy had poor efficacy, and on these patients severe symptoms improved only when azithromycin was added to the treatment.

Conclusions  The drug-resistant M. pneumoniae is very common in Beijing, China. Our modified allele-specific PCR analysis can identify erythromycin resistant mutations more rapidly from specimens than any other method currently available. Erythromycin is still effective for treating patients infected with the mutation negative M. pneumoniae, but this treatment fails to work on mutant organisms. This method can facilitate clinicians in selecting appropriate therapy within short timescales.

     

中国先天性心脏病Nkx2.5基因突变筛查及关联研究

目的探讨Nkx2.5基因突变和单核苷酸多态性(SNPs)与中国先天性心脏病(CHD)患儿的相关性。方法应用聚合酶链反应结合DNA测序技术,对110例CHD患儿及110例正常对照者的Nkx2.5基因外显子1及其侧翼进行突变检测,并对其SNP进行基因分型,分析单个位点的等位基因和基因型频率是否与CHD有关。结果在Nkx2.5基因外显子1中,CHD组及对照组均未发现有任何突变位点,仅在CHD组找到1个新的SNPs;这个新的SNPs位于上游63碱基,其基因型频率在VSD组及TOF组和对照组之间的分布差异有统计学意义(χ2=34.021,df=2,P<0.01;χ2=15.233,df=2,P<0.01),等位基因频率在VSD组及TOF组和对照组之间的分布差异亦有统计学意义(χ2=24.813,df=1,P<0.01;χ2=7.146,df=1,P<0.01)。结论Nkx2.5基因突变与中国先天性心脏病之间无相关,Nkx2.5基因上的SNP与中国先天性心脏病中室间隔缺损和法洛四联症之间存在显著的相关性。