[Comparison of four-coagulation-tests values in normal pregnant women during early and late pregnancy and the influence of age]

Objective: To explore and compare the reference ranges of four coagulation tests in normal pregnant women during early and late pregnancy and the influence of age. Methods: Values of four coagulation tests from 4 974 pregnant women, who gave single birth at Peking University First Hospital, Obstetrics and Gynecology Hospital of Fudan University, West China Second University Hospital, Peking University Third Hospital and Shengjing Hospital of China Medical University from February 2017 to July 2020, were measured and analyzed in this study, including prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and thrombin time (TT). The four normal reference ranges of coagulation during early and late pregnancy phases were expressed as P_2.5-P_97.5. The difference of two pregnancy phases was compared by non-parametric test of two related samples. And the difference between pregnant women of advanced and non-advanced age in the same pregnancy phase was compared by independent sample non-parametric test. Chi-square test was used to compare the incidence of pregnancy complications in different coagulation reference ranges. Results: The reference ranges of PT of normal pregnant women's early and late pregnancy were 10.0-13.9 s and 9.6-12.3 s, the reference ranges of APTT were 22.6-35.3 s and 22.4-30.9 s, the reference ranges of Fib were 2.4-5.0 g/L and 3.0-5.7 g/L, the reference ranges of TT were 12.0-19.0 s and 11.5-18.4 s. Compared with early pregnancy, PT, APTT and TT shortened significantly, while the Fib significantly increased in late pregnancy (all P<0.001). PT, APTT and TT of advanced and non-advanced age pregnant women were significantly different (all P<0.01). Compared with the ranges of non-pregnant population, more pregnant women were included in the normal pregnant reference ranges of PT in early pregnancy and APTT in the early and late pregnancy, while the incidence of pregnancy complications had no significant differences (all P>0.05). The incidence of fetal distress was higher and the incidence of preterm birth was lower in the reference range of PT in late pregnancy. The incidence of gestational diabetes mellitus was higher in the early and late gestational Fib reference ranges, and the incidence of hypertensive disorders in pregnancy was higher in the late gestational Fib reference range (all P<0.05). Conclusions: The coagulation function of pregnant women increases significantly with the growth of pregnancy, and there is a significant difference between advanced significantly and non-advanced age pregnant women. The recommended ranges of normal pregnant women's early and late pregnancy PT are 10.0-13.9 s and 9.6-12.3 s, the recommended ranges of APTT are 22.6-35.3 s and 22.4-30.9 s, the recommended ranges of TT are 12.0-19.0 s and 11.5-18.4 s. The appropriate ranges of normal pregnant women's early and late pregnancy Fib still need further exploration.

[Clinicopathological features of intestinal mucosal lesions in AIDS patients and their relation with CD4+ T lymphocytes]

Objective: To observe the histopathological features of different opportunistic infections and tumors of the intestinal mucosa in AIDS patients, and to explore the correlation between different lesions and CD4+ T lymphocyte levels. Methods: Colonic mucosal biopsy specimens of 263 patients with clinically diagnosed AIDS and abdominal pain, diarrhea, blood in the stool and other gastrointestinal symptoms were collected from Beijing Ditan Hospital from 2010 to 2018. There were 232 males and 31 females, with age range 10-81 (mean 40±13) years. HE staining, histochemical special staining, immunohistochemical staining, and in-situ hybridization were used to detect the expression of different opportunistic infection pathogens, tumors and CD4+ T lymphocytes. Peripheral blood was also taken for CD4+ T lymphocytes, CD8+ T lymphocytes, HIV viral load and routine indicators. Results: The cohort included 263 intestinal mucosal biopsy specimens. There were 175 cases (66.5%) of non-specific inflammation, and pathogens were detected in 41 cases (15.6%), including 20 cases(7.6%) of cytomegalovirus (CMV) infection, 12 cases (4.6%) of mycobacterial infection, eight cases (3.0%) of amoeba infestation, and one case (0.3%) of talaromycesmarneffei infection; there were also 41 (15.6%) neoplastic lesions including 25 cases (9.5%) of intraepithelial neoplasia, 10 cases (3.8%) of adenocarcinoma and squamous cell carcinoma, six cases (2.3%) of lymphoma; and six cases (2.3%) of ulcerative colitis. The peripheral blood CD4+T lymphocyte levels of patients with CMV, mycobacteria and talaromycesmarneffei were less than 200/μL; the peripheral blood CD4+ T lymphocyte level (P<0.01) and intestinal mucosa CD4+T lymphocytes (P<0.01) were all significantly lower than those in patients with non-specific inflammation. The peripheral red blood cells and hemoglobin levels of patients with CMV and mycobacterial infection (P<0.01), adenocarcinoma and squamous cell carcinoma (P<0.05) were significantly lower than those of non-specific inflammation patients. Conclusions: Pathologic examination of intestinal mucosa can identify specific infections and neoplastic lesions in AIDS patients; the most common lesions are non-specific inflammation, and CMV infection is the most common opportunistic infections; CMV, mycobacteria and talaromycesmarneffei infections are associated with decreased levels of CD4+ T lymphocytes in peripheral blood and intestinal mucosa; entamoeba histolytica infestation and non-HIV-related neoplastic lesions such as intraepithelial neoplasia, adenocarcinoma and squamous cell carcinoma are not associated with changes in AIDS immune function.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

[Inflammatory myofibroblastic tumour of thyroid: a case report]

A elderly woman patient，with a unclear boundary,solid,smooth surface,moderately active mass that estimated 0.4 cm at its greatest diameter in the left lobe of thyroid. Ultrasonography revealed a hypoechoic mass in the left lobe and Computed Tomography showed a 38 mm×25 mm×23 mm oval lesion with uniform density in the left lobe also. The surgical findings revealed tumor located in the inner side of left thyroid lobe near the isthmus,with unclear boundary. Pathological examination showed unclear boundaries between thyroid and tumor,the tumor cells attack into the muscle tissue,braided/ fascicles spindle shaped or star shaped myofibroblasts cells in the tumor area with myxedema inflammatory background and the lesion did not have any mitotic figures. Immunohistochemical analysis indicated that the spindle cells were positive for Vim,ACT,SMA,Bcl2 and ClyD1,and focal lesion histiocytes showed focal positive for CD68,CK and S-100,but negative for DES,Mgo,CD99,CD34,CD117,IgG4,ALK-1.The pathological diagnosis supports inflammatory myofibroblastic tumor of thyroid. Imaging and immunohistochemistry and others are useful in differential diagnosis.

Prognostic significance of latent membrane protein 1 expression in non-Hodgkin lymphoma: A meta-analysis

BACKGROUND

The prognostic value of latent membrane protein 1 (LMP1) in non-Hodgkin lymphoma (NHL) has been evaluated in several studies. However, the conclusions remain controversial.

METHODS

We searched relevant literatures from Embase, PubMed, and China National Knowledge Infrastructure Platform databases and performed a meta-analysis to evaluate the prognostic significance of LMP1 expression in NHL. Pooled hazard ratio (HR), 95% confidence interval (CI), and P value were calculated. Nine relevant studies were analyzed in this meta-analysis. We performed a pooled analysis to assess the association between LMP1 expression and overall survival of NHL patients.

RESULTS

Our results revealed that LMP1-positive NHL patients had significantly poorer outcomes than LMP1-negative patients (HR = 2.13, 95% CI = 1.31-3.46, Pheterogeneity = 0.005, I = 63.5%). Furthermore, in the subgroup analysis stratified by country, a statistically significant association was found among Chinese (HR = 2.80, 95% CI = 1.53-5.15, Pheterogeneity = 0.342, I = 6.9%); however, no statistically significant relations were found among Japanese (HR = 1.55, 95% CI = 0.74-3.24, Pheterogeneity = 0.020, I = 65.7%).

CONCLUSION

The expression of LMP1 can be considered a poor predictor of survival in patients with NHL. In addition, LMP1 expression assessment could provide more detailed information for patients with NHL and could be used to optimize therapeutic schemes.

KRAS and BRAF mutations in serum exosomes from patients with colorectal cancer in a Chinese population

The efficacy of epidermal growth factor receptor- targeted therapy is significantly associated with Kirsten rat sarcoma viral oncogene homolog (KRAS) and B-raf serine/threonine kinase proto-oncogene (BRAF) mutation in patients with colorectal cancer (CRC), for which the standard gene testing is currently performed using tumor tissue DNA. The aim of the present study was to compare the presence of KRAS and BRAF mutations in the serum exosome and primary tumor tissue from patients with CRC. Genomic DNA were extracted from the tumor tissues of 35 patients with histologically-confirmed CRC and exosomal mRNA were obtained from peripheral blood, which were collected from the corresponding patients prior to surgery. Three mutations in the KRAS gene (codons 12, 13 and 61) and a mutation in the BRAF gene (codon 600) were detected using a polymerase chain reaction-based sequencing method and their presence were compared between tumor tissues and the matched serum exosomes. The KRAS mutation rates in tumor tissues and the matched serum exosomes were 57.6 and 42.4%, respectively, which was not significantly different (P=0.063). The detection rate of the BRAF mutation was 24.2 and 18.2% in tumor tissues and the matched serum exosomes, respectively, and there was no significant difference (P=0.500). The patients with CRC that had a KRAS mutation of codon 12 in exon 2 in their tumor tissues and serum exosomes were significantly older compared with those without this mutation (tumor tissue, P=0.002; serum exosome, P=0.022). The sensitivity of KRAS and BRAF mutation detection using exosomal mRNA was 73.7 and 75%, respectively. The specificity of the detected mutations exhibited an efficiency of 100%, and the total consistency rate was 94.9 and 93.9% for KRAS and BRAF mutations, respectively. These results suggested that serum exosomal mRNA may be used as a novel source for the rapid and non-invasive genotyping of patients with CRC.

Discovery of potent human lactate dehydrogenase A (LDHA) inhibitors with antiproliferative activity against lung cancer cells: virtual screening and biological evaluation

Human lactate dehydrogenase A (LDHA) plays a crucial role in the promotion of glycolysis in invasive tumor cells, and recently, it has been considered as a vital therapeutic target in the field of oncology. Herein, by combining docking-based virtual screening with in vitro biochemical evaluation, we report the discovery of a potent LDHA inhibitor with antiproliferative activity. The enzymatic assay suggested that the identified compound 7 has a good inhibitory activity (IC50 = 0.36 μM) against LDHA. The in vitro cytotoxicity assay demonstrated that compound 7 reduces the growth of A549 and NCI-H1975 lung cancer cells, with EC50 values of 5.5 and 3.0 μM, respectively. These findings indicate that compound 7 could be employed as a useful probe to explore the pharmacology of LDHA.

Effectiveness of circulating tumor DNA for detection of KRAS gene mutations in colorectal cancer patients: a meta-analysis

Circulating tumor DNA (ctDNA) can be identified in the peripheral blood of patients and harbors the genomic alterations found in tumor tissues, which provides a noninvasive approach for detection of gene mutations. We conducted this meta-analysis to investigate whether ctDNA can be used for monitoring KRAS gene mutations in colorectal cancer (CRC) patients. Medline, Embase, Cochrane Library and Web of Science were searched for the included eligible studies in English, and data were extracted for statistical analysis according to the numbers of true-positive (TP), true-negative (TN), false-positive (FP) and false-negative (FN) cases. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated, and the area under the receiver operating characteristic curve (AUROC) was used to evaluate the diagnostic performance. After independent searching and reviewing, 21 studies involving 1,812 cancer patients were analyzed. The overall sensitivity, specificity and DOR were 0.67 (95% confidence interval [CI] =0.55-0.78), 0.96 (95% CI =0.93-0.98) and 53.95 (95% CI =26.24-110.92), respectively. The AUROC was 0.95 (95% CI =0.92-0.96), which indicated the high diagnostic accuracy of ctDNA. After stratified analysis, we found the higher diagnostic accuracy in subgroup of patients detected in blood sample of plasma. The ctDNA may be an ideal source for detection of KRAS gene mutations in CRC patients with high specificity and diagnostic value.

Improved Anatomical Specificity of Non-invasive Neuro-stimulation by High Frequency (5 MHz) Ultrasound

Low frequency ultrasound (<1 MHz) has been demonstrated to be a promising approach for non-invasive neuro-stimulation. However, the focal width is limited to be half centimeter scale. Minimizing the stimulation region with higher frequency ultrasound will provide a great opportunity to expand its application. This study first time examines the feasibility of using high frequency (5 MHz) ultrasound to achieve neuro-stimulation in brain, and verifies the anatomical specificity of neuro-stimulation in vivo. 1 MHz and 5 MHz ultrasound stimulation were evaluated in the same group of mice. Electromyography (EMG) collected from tail muscles together with the motion response videos were analyzed for evaluating the stimulation effects. Our results indicate that 5 MHz ultrasound can successfully achieve neuro-stimulation. The equivalent diameter (ED) of the stimulation region with 5 MHz ultrasound (0.29 ± 0.08 mm) is significantly smaller than that with 1 MHz (0.83 ± 0.11 mm). The response latency of 5 MHz ultrasound (45 ± 31 ms) is also shorter than that of 1 MHz ultrasound (208 ± 111 ms). Consequently, high frequency (5 MHz) ultrasound can successfully activate the brain circuits in mice. It provides a smaller stimulation region, which offers improved anatomical specificity for neuro-stimulation in a non-invasive manner.

[NELL-1: a novel highly efficient and specific growth factor]

Regeneration of bone tissue, as well as other tissues, requires involvement and interaction of cells, scaffolds and relevant growth factors, among which growth factors play a crucial role in maintaining the stability of microenvironment. Nel-like-type 1 molecule (NELL-1), a novel growth factor in tissue engineering, has been studied intensively in recent years. Researches mainly covered gene and protein structure and their expression profiling, biological function, molecular mechanisms and disease relevance. NELL-1 expressed in embryonic tissue is essential for growth and development of bone tissue. NELL-1 presents excellent abilities of inducing bone and cartilage regeneration,especially with high specificity to chondrocyte lineage. Compared with classic osteogenic growth factor bone morphogenetic protein 2 (BMP-2), the process of osteogenesis interacted with NELL-1 exhibits stronger specificity, higher bone density and fewerside effects. Furthermore, a recent study shows synergistic effects of NELL-1 and BMP-2. NELL-1 enhances the osteogenic reaction induced by BMP-2 of cells and notably declines inflammation response caused by BMP-2. This review evaluates the current research progress of the function and application of NELL-1 by the systematic method of evidence-based medicine.

Global Methylation Patterns and Their Relationship with Gene Expression and Small RNA in Rice Lines with Different Ploidy

Whole genome duplication (WGD) is a major force in angiosperm evolution. Whether WGD is accompanied by the evolution of epigenetic regulators remains to be explored. Here we investigate whole genome methylation, gene expression, and miRNA regulation among monoploid, diploid, and triploid rice plants isolated from a twin-seedling population. The DNA methylation patterns in the three different ploidy plants were highly similar, with DNA methylation primarily enriched in the promoters. We examined the methylation of single genes and detected around 25,500 methylated genes, of which 22,751 were methylated in all three lines. Significantly divergent DNA methylation patterns between each pair of three lines were only detected in 64 genes, though more genes were found to exhibit differential expression. Analysis of DNA methylation and expression patterns showed that higher DNA methylation levels upstream of the transcription start sites are correlated with higher levels of expression of related genes; whereas higher DNA methylation levels in gene body regions are correlated with lower levels of expression. We also carried out high-throughput sequencing of small RNA libraries and identified 36 new miRNAs. These miRNAs have different expression levels depending on the ploidy.

Identification of commonly dysregulated genes in colorectal cancer by integrating analysis of RNA-Seq data and qRT-PCR validation

The progression of colorectal cancer (CRC) is a multistep process and metastatic CRC is always incurable; consequently, CRC is the leading cause of cancer-related deaths. There is therefore an urgent need for identifying useful biomarkers with enough sensitivity and specificity to detect this disease at early stages, which will significantly reduce the mortality for this malignancy. In this study, we performed an integrating analysis of different RNA-Seq data sets to find new candidate biomarkers for diagnosis, prognosis and as therapeutic targets for this malignancy, as well as to elucidate the molecular mechanisms of CRC carcinogenesis. We identified 883 differentially expressed genes (DEGs) across the studies between CRC and normal control (NC) tissues by combining five RNA-Seq data sets. Gene function analysis revealed high correlation with carcinogenesis. The top 10 most significantly DEGs were further evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) in both rectal cancer (RC) and colon cancer (CC), and the results matched well with integrating data, suggesting that the method of integrating analysis of different RNA-seq data sets is acceptable. Therefore, integrating analysis of different RNA-seq data sets may be a useful way to overcome the limitation of small sample size in a single RNA-seq study. In addition, our study showed that some genes, such as SIM2, ADAMTS6, FOXD4L4 and DNAH5, may have an important role in the development of CRC, which could be applied for diagnosis, prognosis and as therapy for this malignancy. Our findings would also help to understand the pathology of CRC.

Identification of the man-made barium copper silicate pigments among some ancient Chinese artifacts through spectroscopic analysis

This article describes the complementary application of non-invasive micro-Raman spectroscopy and energy dispersive X-ray fluorescence spectrometry to the characterization of some ancient Chinese silicate artifacts. A total of 28 samples dated from fourth century BC to third century AD were analyzed. The results of chemical analysis showed that the vitreous PbO-BaO-SiO2 material was used to sinter these silicate artifacts. The barium copper silicate pigments including BaCuSi4O10, BaCuSi2O6 and BaCu2Si2O7 were widely identified from colorful areas of the samples by Raman spectroscopy. In addition, other crystalline phases such as Fe2O3, BaSi2O5, BaSO4, PbCO3 and quartz were also identified. The present study provides very valuable information to trace the technical evolution of man-made barium copper silicate pigments and their close relationship with the making of ancient PbO-BaO-SiO2 glaze and glass.

HIV and aging: insights from the Asia Pacific HIV Observational Database (APHOD)

OBJECTIVES

The proportion of people living with HIV/AIDS in the ageing population (>50 years old) is increasing. We aimed to explore the relationship between older age and treatment outcomes in HIV-positive persons from the Asia Pacific region.

METHODS

Patients from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD) were included in the analysis. We used survival methods to assess the association between older age and all-cause mortality, as well as time to treatment modification. We used regression analyses to evaluate changes in CD4 counts after combination antiretroviral therapy (cART) initiation and determined the odds of detectable viral load, up to 24 months of treatment.

RESULTS

A total of 7142 patients were included in these analyses (60% in TAHOD and 40% in AHOD), of whom 25% were >50 years old. In multivariable analyses, those aged > 50 years were at least twice as likely to die as those aged 30-39 years [hazard ratio (HR) for 50-59 years: 2.27; 95% confidence interval (CI) 1.34-3.83; HR for > 60 years: 4.28; 95% CI 2.42-7.55]. The effect of older age on CD4 count changes was insignificant (p-trend=0.06). The odds of detectable viral load after cART initiation decreased with age (p-trend=< 0.0001). The effect of older age on time to first treatment modification was insignificant (p-trend=0.21). We found no statistically significant differences in outcomes between AHOD and TAHOD participants for all endpoints examined.

CONCLUSIONS

The associations between older age and typical patient outcomes in HIV-positive patients from the Asia Pacific region are similar in AHOD and TAHOD. Our data indicate that 'age effects' traverse the resource-rich and resource-limited divide and that future ageing-related findings might be applicable to each setting.

Clinical significance of detection of stool miR34b/c methylation by MDA-MSP in patients with colorectal cancer

AIM: To investigate the value of detection of stool miR34b/c methylation in the diagnosis of colorectal cancer.

METHODS: Multiple displacement amplification (MDA) was used to amplify bisulfite modified genomic DNA, and methylation-specific PCR (MSP) was used to analyze methylation of miR34b/c in colorectal cancer tissue and stool DNA from 126 patients with colorectal cancer and stool DNA in 64 patients with benign diseases.

RESULTS: In 126 cancer specimens and matched tumor-adjacent tissue specimens, 95.2% (120/126) and 11.9% (15/126) showed methylation of miR34b/c, and there is a significant difference in the rate of methylation between them (P < 0.01). There was no significant correlation between methylation of miR34b/c and clinicopathologic parameters (all P > 0.05). The rate of methylation of miR34b/c in stool DNA was significantly higher in cancer patients than in patients with benign disease (90.2% vs 7.8%, P < 0.01). The sensitivity and specificity of detection of miR34b/c methylation in diagnosis of colorectal cancer were 90.2% and 92.2%, respectively.

CONCLUSION: The hypermethylation of miR34b/c is frequent in colorectal cancer and may be used as a novel diagnostic biomarker for colorectal cancer. MDA and MSP techniques provide ideal tools for analysis of methylation in trace DNA samples.

Microarray-based gene expression profiles in rabbit retina due to negative pressure suction

We investigated a possible molecular pathogenesis involving retinal ganglion cell apoptosis following transient high intraocular pressure. Changes in the gene expression profiles of the retina were detected via gene chip methodology. Twelve New Zealand white rabbits were randomly assigned to control and 3-min negative pressure suction groups. The control group was treated only with a laser, and the experimental group was also treated with suction for 3 min, using a negative pressure generator. Total RNA was then extracted from the retinal tissue at different recovery stages to analyze gene expression profiles using the Agilent rabbit one-way gene chip. The groups were then compared. Immediately after negative pressure suction induction, 704 genes were differentially expressed. Among these, 485 genes were upregulated, and 219 were downregulated. Expression of the genes encoding CRYAA, CRYAB, and TLR3 genes, which are involved in apoptosis, was elevated. The KRT18 gene, which is involved in apoptosis, had reduced expression. Seven days after negative pressure suction, 482 genes were differentially expressed. Among these, 178 genes were upregulated, and 304 were downregulated. Expression of the genes encoding CRYAB, IL1-BETA and IL1R1, which are involved in apoptosis, was upregulated. Ten days after negative pressure suction, 402 genes were differentially expressed. Of these, 213 genes were upregulated, and 189 were downregulated. Apoptosis genes CRYAB, CRYBA3, CRYBB2, IL1- BETA, and IL1R1 showed higher expression levels. We concluded that negative pressure suction for long periods of time (for example, 3 min) results in changes in gene expression. Genes with higher fold changes help protect retinal ganglion cells from apoptosis. We suggest that promoting the expression of these genes should be considered as a new means for treating ischemic-hypoxic retinopathy.

Thermal Effects and Small Signal Modulation of 1.3-μm InAs/GaAs Self-Assembled Quantum-Dot Lasers

We investigate the influence of thermal effects on the high-speed performance of 1.3-μm InAs/GaAs quantum-dot lasers in a wide temperature range (5-50°C). Ridge waveguide devices with 1.1 mm cavity length exhibit small signal modulation bandwidths of 7.51 GHz at 5°C and 3.98 GHz at 50°C. Temperature-dependent K-factor, differential gain, and gain compression factor are studied. While the intrinsic damping-limited modulation bandwidth is as high as 23 GHz, the actual modulation bandwidth is limited by carrier thermalization under continuous wave operation. Saturation of the resonance frequency was found to be the result of thermal reduction in the differential gain, which may originate from carrier thermalization.

Identification of cytoplasm types in rapeseed (Brassica napus L.) accessions by a multiplex PCR assay

Cytoplasmic male sterility (CMS) has widely been used as an efficient pollination control system in rapeseed hybrid production. Identification of cytoplasm type of rapeseed accessions is becoming the most important basic work for hybrid-rapeseed breeding. In this study, we report a simple multiplex PCR method to distinguish the existing common cytoplasm resources, Pol, Nap, Cam, Ogu and Ogu-NWSUAF cytoplasm, in rapeseed. Cytoplasm type of 35 F(1) hybrids and 140 rapeseed open pollinated varieties or breeding lines in our rapeseed breeding programme were tested by this method. The results indicated that 10 of 35 F(1) hybrids are the Nap, and 25 the Pol cytoplasm type, which is consistent with the information provided by the breeders. Out of 140 accessions tested, 100 (71.4%), 21 (15%) and 19 (13.6%) accessions possess Nap, Cam and Pol cytoplasm, respectively. All 19 accessions with Pol cytoplasm are from China. Pedigree analysis indicated that these accessions with Pol cytoplasm were either restorers for Pol CMS, including Shaan 2C, Huiyehui, 220, etc. or derived from hybrids with Pol CMS as female parent. Our molecular results are consistent with those of the classical testcross, suggesting the reliability of this method. The multiplex PCR assay method can be applied to CMS "three-line" breeding, selection and validation of hybrid rapeseed.

[Expression of CD133 in bone marrow cells of patients with leukemia and myelodysplastic syndrome]

To explore the relationship between the expression of CD133 and pathogenesis of leukemia and MDS, immunocytochemistry method was used to examine the expression of CD133 in bone marrow cells of patients with leukemia and MDS. The results showed that the positive rate of CD133 in 41 acute leukemia patients was 51.2%. The expression of CD133 in AML patients (16/29, 55.2%) was significantly higher than that in control group (2/15, 13.3%). There was no significant difference in CD133 expression between CML and control group. The positive rate of CD133 in 9 patients with MDS was 55.56% (5/9). There was no significant difference between MDS and normal control. The expression of CD133 in all leukemia cells with CD34(+) was higher than that in leukemia cells with CD34(-), and there was significant difference in expression of CD133 between them (P < 0.05). The expression of CD133 had no relationship with the clinical prognostic factors such as sex, age, the percentage of leukemic cells in peripheral blood and in bone marrow, WBC counts, hemoglobin concentration, platelet counts and LDH level. It is concluded that the expression of CD133 in bone marrow cells of patients with AML is higher than that in control group. The expression of CD133 is significantly correlated with the expression of CD34. The high expression of CD133 may be an adverse prognostic factor in acute leukemia.

Functional properties of a new low-molecular-weight glutenin subunit gene from a bread wheat cultivar

Some allelic forms of low-molecular-weight glutenin subunit (LMW-GS) can greatly influence the end-use of wheat flours, understanding the function of each allele of LMW-GS is important to wheat quality breeding. A LMW-GS gene XYGluD3-LMWGS 1(AY263369) has been cloned from bread wheat cultivar Xiaoyan 6. The deduced protein contained nine cystine residues, one more than that in all other LMW-GSs reported previously, indicating that it is either a new gene or a new allele of a known LMW-GS gene. In this study, the gene was expressed in E. coil in large scale for the testing of its functional property. Reactive Red 120-Agarose resin was used efficiently to purify the expressed LMW-GS proteins from bacteria, with the lactic acid-sodium lactate buffer (pH 4.5) which contained low concentration SDS as elution solution. The purified protein (belonging to the LMW-m family, MW about 35 KDa) was supplemented into a base flour, the results of 10 g dough mixing test indicated that incorporation of the LMW-GS increased the strength of the dough, with significant increases in mixing time (MT) and peak width (PW), and decrease in breakdown in resistance (RBD) compared with the control. In addition, the dough with incorporation of the LMW-GS had more glutenin macropolyeric protein than the control, suggesting that the LMW-GS participated in forming larger glutenin polymers, and greatly contributed to dough strength. The changes in mixing parameters and the amount of glutenin macropolyeric protein were related to the quantity of incorporating subunits.

H22, a major resistance gene to the Hessian fly (Mayetiola destructor), is mapped to the distal region of wheat chromosome 1DS

H22 is a major resistance gene conferring high-level of antibiosis to Hessian fly [Mayetiola destructor (Say)] larvae. It was previously assigned to wheat chromosome 1D through monosomic analysis (Raupp et al. in J Hered 84:142-145, 1993). The objective of this study was to identify molecular markers that can be used for marker-assisted selection for wheat breeding, and to further map this gene toward map-based cloning. Forty-five simple sequence repeat (SSR) and sequence-tagged site (STS) markers specific to chromosome 1D were evaluated for linkage to H22 using a segregating population consisting of 192 F(2:3) families, which were derived from the cross Tugela-Dn1 x KS85WGRC01(H22). The STS Xhor2kv and SSR Xgdm33 are two flanking markers that are tightly linked to H22 at genetic distances of 0.3 and 1.0 cM, respectively. Five other SSR markers including Xgpw7082, Xwmc147, Xcfd15, Xwmc432 and Xwmc336 were also linked to H22 at the distance from 0.8 to 20.8 cM. Analysis of Chinese Spring (CS) deletion lines revealed that all the H22-linked markers are located distal to the breakpoint of del 1DS-5, indicating that the H22 gene is located at the distal 30% region on the short arm of wheat chromosome 1D. Genomic comparison suggested that the H22 gene is located in the same or similar chromosomal region as the leaf rust resistance genes Lr21 and Lr40 on 1DS, and orthologous to the H9 gene cluster of 1AS.

Analysis of MS2Bnap genomic DNA homologous to MS2 gene from Arabidopsis thaliana in two dominant digenic male sterile accessions of oilseed rape (Brassica napus L.)

PCR technique was employed to isolate gene homologous to the MS2Bnap (X99922.1) from two rapeseed (Brassica napus L.) dominant digenic male sterile lines, namely 220A (male sterile) and 220B (male fertile), 6A (male sterile) and 6C (male fertile). The isolated 2,581 bp sequences from 220A (named 220A-gDNA, GenBank accession number AY288778), 220B (220B-gDNA, AY257490), 6A (6A-gDNA, DQ060318) and 6C (6C-gDNA, DQ060319) all contained six introns. Forty-one single nucleotide polymorphism (SNP) sites were detected by alignment of these four sequences, seven of them dispersed in the exon regions. Two SNPs (1247, 1656) were detected between 220A-gDNA and 220B-gDNA, and the one at nucleotide 1247 of 220A-gDNA with A replaced by C was a missense mutation, which may be the putative male sterility site in 220A. All eight SNPs identified between 6A-gDNA and 6C-gDNA were located in the third intron, so the proteins encoded by them are the same. The one SNP between 6A-/6C-gDNA and 220A-/220B-gDNA at nucleotide 2474 of 220A-/220B-gDNA with C replaced by G was a missense mutation. Mutation site of BNMS2PROT (CAA68190.1) encoded by MS2Bnap in 220A(254) and 6A/6C(584) is different, which indicated dominant digenic male sterile line 220AB and 6CA have some difference in the molecular level. Comparison of structure of MS2Bnap in B. napus with that of MS2 in Arabidopsis thaliana revealed that the similarity of exons between these two genes is higher than that of introns.

Predicting gas chromatographic retention times of 209 polybrominated diphenyls (PBBs) for different temperature programs

A method has been developed to predict the retention times of 209 individual polybrominated diphenyl congeners for different temperature programs. The retention equations lnk'=A+B/T of five PBBs in gas chromatography (GC) were used to evaluate the properties of the regression coefficients A and B, which are widely accepted as being highly reliable chromatographic retentions. The quantitative relationships between the A and B values of PCBs and those of PBBs were found. The regression equations derived have coefficients of determination greater than 0.999. The A, B values of any PBB can be predicted by using the A, B values of the PCB according to these relationships. Using these predicted A and B values, the retention times of all PBBs can be predicted. This is an important advance in the identification of PBBs because at present there are only a few PBB standards available.

The discovery,genetic analysis and gene mapping of earliness rice (Oryza sativa L.) D64B

D64B, an achromatic early mutation, was discovered from indica rice preserver line D63B. D64B were crossed with inhomogeneous sterile lines, preserver lines and restorer lines, most of their F1 shared the same heading dates as D64B. The results indicated that D64B possessed the characteristic of dominant earliness. To analyze the earliness trait, positive and negative crosses F2 and BC1 from the cross of D64B and Shuhui 527 were cultivated. Their heading dates showed double apices distributing with same apex values. According to apex vale value -103 d, plants of the F2 and BC1 were separated into early plants and late plants, which were tested with Chi2 value. The results suggested that the segregation ratio of number of early to late plant fitted to 3:1 and 1:1 for positive and negative cross F2 and BC1, respectively, and that the earliness of D64B was controlled by a single dominant major gene. To map the gene, the polymorphisms between D64B and Shuhui 527 was analyzed with reported 356 SSR primers and 59 primers showed polymorphisms. The earliness-lateness near isogenic pools, early plants and late plants from F2 of Shuhui 527 x D64B were further amplified with the 59 primers. The results indicated that there were polymorphisms on both RM279 and RM71. Their results being analyzed with MAPMAKER/EXP3.0 software, the dominant major gene was located on the top arm of rice chromosome 2 and between the two SSR markers, RM279 and RM71, with genetic distance of 12.6 cM and 13.3 cM, respectively. According to reported data, the gene was first discovered and tentatively named as Ef-3(t). In breeding practice, sterile line D64A had been bred with D64B.

Genetic distances revealed by morphological characters, isozymes, proteins and RAPD markers and their relationships with hybrid performance in oilseed rape (Brassica napus L.)

Genetic distances (GDs) based on morphological characters, isozymes and storage proteins, and random amplified polymorphic DNAs (RAPD) were used to predict the performance and heterosis of crosses in oilseed rape (Brassica napus L.). Six male-sterile lines carrying the widely used Shaan2A cytoplasm were crossed with five restorer lines to produce 30 F1 hybrids. These 30 hybrids and their parents were evaluated for seven agronomically important traits and their mid-parent heterosis (MPH) at Yangling, Shaanxi province in Northwest China for 2 years. Genetic similarity among the parents based on 34 isozyme and seven protein markers was higher than that based on 136 RAPDs and/or 48 morphological markers. No significant correlation was detected among these three sets of data. Associations between the different estimates of GDs and F1 performance for some agronomic traits were significant, but not for seed yield. In order to enhance the predicting efficiency, we selected 114 significant markers and 43 favoring markers following statistical comparison of the mean values of the yield components between the heterozygous group (where the marker is present only in one parent of each hybrid) and the homozygous group (where the marker is either present or absent in both parents of each hybrid) of the 30 hybrids. Parental GD based on total polymorphic markers (GDtotal, indicating general heterozygosity), significant markers (GDsign, indicating specific heterozygosity) and favoring markers (GDfavor, indicating favoring-marker heterozygosity) were calculated. The correlation between GDfavor or GDsign and hybrid performance was higher than the correlation between GDtotal and hybrid performance. GDsign and GDfavor significantly correlated with plant height, seeds per silique and seed yield, but not with the MPH of the other six agronomic traits with the exception of plant height. The information obtained in this study on the genetic diversity of the parental lines does not appear to be reliable for predicting F1 yield and heterosis.

Space-time clustering of childhood Type 1 diabetes in Devon and Cornwall, England

AIMS

Several studies on space-time clustering have been reported in childhood diabetes, but the findings are conflicting. The present study was undertaken to examine whether such clustering could be detected at either birth or the time of diagnosis in the far South-west of England.

METHODS

A cohort of 518 children aged 0-15 years and diagnosed with Type 1 diabetes from 1975 to 1996 contained in the population-based Cornwall and Plymouth Children's Diabetes Register (CPCDR) were included in the analyses. The case ascertainment for this register is estimated to be 94.4% complete. Mantel's modification of Knox's method was employed. A method based on K-function was also used, for the first time, to investigate the space-time clustering of diabetes.

RESULTS

Significant space-time clustering at diagnosis was found by the Knox's test in the following combinations of critical cut-off thresholds: 25, 35 and 50 km and 90, 270 and 360 days (all P < 0.05), with the highest significance found at 35 km and 360 days (P = 0.0011). K-function analysis also confirmed the overall clustering (P = 0.013).

CONCLUSIONS

There is strong evidence of space-time clustering in the onset of childhood Type 1 diabetes in Devon and Cornwall, England. These results lend some support to the hypothesis that viral infections and some unknown localized environmental factors play a role in the development of childhood Type 1 diabetes.

Drinking water composition and childhood-onset Type 1 diabetes mellitus in Devon and Cornwall, England

AIMS

Previous studies have reported inconsistent results on the association between some compositions (e.g. nitrate) in domestic water and the risk of childhood-onset Type 1 diabetes mellitus. This study aimed to examine the relationship between nitrate, zinc and magnesium in drinking water and the risk of childhood-onset Type 1 diabetes mellitus.

METHODS

The study covers the Cornwall and the former Plymouth Health Authority Regions in the far south-west of England. Five hundred and seventeen children, aged 0-15 years, diagnosed with Type 1 diabetes mellitus between 1975 and 1996, were identified for inclusion in the study. Domestic water data (nitrate, Zn, Mg, Cu, Al, Ca, Fe and Mn) between 1993 and 1997 were provided by South-west Water Plc, UK, for each of the 40 Water Supply Zones in which the subjects had been resident at the time of diagnosis. The standardized incidence ratio (SIR) of the disease was calculated for each Water Supply Zone using the UK 1991 census population data. The relationship between the SIR of the disease and the water quality indicators in thirds (three strata of low, medium and high concentrations) was examined by chi2 test for trend and Poisson regression analysis.

RESULTS

The initial analyses by chi2 test for trend on the relation of SIRs and drinking water compositions suggested that copper, magnesium and nitrate might have some protective effects, but Poisson regression analyses showed that only zinc and magnesium were significant factors. The data suggest that the incidence rate of childhood diabetes is significantly lower when the concentrations of zinc and magnesium in the domestic drinking water are in the range 22.27-27.00 microg/l (incidence rate ratio (IRR), 0.76; 95% CI, 0.59-0.97) and greater than 2.61 mg/l (IRR, 0.72; 95% CI, 0.58-0.91), respectively.

CONCLUSIONS

Our findings suggest evidence of a possible association between zinc and magnesium in the domestic drinking water and childhood diabetes in the far south-west of England. However, these possible protective effects of zinc and magnesium in domestic drinking water warrant further confirmation.

[Purification and biochemical characterization of high-molecular-weight-glutenin subunits 14 and 15]

The high molecular weight glutenin subunits 14 and 15 were purified from cultivars of bread wheat (Triticum aestivum) Xiaoyan 6 by preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) appled a new method for visualizing protein in gels. N-terminal amino acid sequences were homologous comparing with other High-Molecular-Weight glutenin subunits. The result suggested that they were basic protein analyzed by two-dimensional electrophoresis of IEF(Isoelectric Focussing) x SDS-PAGE and NEPHGE(Non-Equilibrium PI-gradient Electrophoresis) x SDS-PAGE.

Incidence of childhood-onset Type 1 diabetes mellitus in Devon and Cornwall, England, 1975-1996

AIMS

To determine the incidence of Type 1 diabetes mellitus (DM) in children aged 0-15 years in the far south-west of England between 1975 and 1996.

METHODS

Patient information was collected to set up the Cornwall and Plymouth Children's Diabetes Register (CPCDR) through two main data sources; hospitals and the general practitioners in all surgeries in the study region. All children under 16 years living within Cornwall and the Isles of Scilly, and the former Plymouth Health Authorities and diagnosed as having Type 1 DM during the study period were included. The case ascertainment was estimated by a capture-recapture method. Trends and differences in incidence of sex, age, time period and district of diagnosis were analysed by Poisson regression analysis. Roger's method was used to estimate the seasonal variations.

RESULTS

A total of 522 subjects aged between 0 and 15 years were identified from 01/01/1975 to 31/12/1996, giving an overall crude incidence of 14.9/ 100 000 population/year. The case ascertainment was 94.4% (95% confidence interval (CI) 91.4- 97.6%) for the whole register. Poisson regression analysis showed that a significant increase of incidence (2.49% per year) was observed throughout the 22-year study period, which was mainly a result of the significant increase in the 0-4 year age-group (6.29% per year). The incidence significantly differed among the 22-years (P = 0.007), the three age groups (0-4, 5-9 and 10-14 years, P<0.001) and different sexes (P=0.049). The significant seasonal variations were detected with peak incidence appearing in autumn and winter.

CONCLUSIONS

The first validated childhood-onset diabetes register has been set up in the far south-west of England. The incidence of childhood Type 1 DM in this region has increased significantly over the past two decades, especially in children under 5 years.

Constitutive expression of CD26/dipeptidylpeptidase IV on peripheral blood B lymphocytes of patients with B chronic lymphocytic leukaemia

We have investigated the expression of the ectoenzyme dipeptidylpeptidase IV (DPP IV)/CD26 on lymphocytes obtained from patients with B chronic lymphocytic leukaemia (B-CLL) and compared it with healthy subjects. Using two-colour immunofluorescence analysis with CD26 and CD20 or CD23 monoclonal antibodies, CD26 was found undetectable on peripheral resting B-cells (CD20+ CD23-) from normal donors whereas it was expressed on B-cells activated in vitro with interleukin (IL)-4 and Staphylococcus aureus strain cowan I (CD20+ CD23+). The expression of CD26 on leukaemic B-cells (CD20+ CD23+) was clearly induced in 22 out of 25 patients examined. Consequently, induced levels of CD26 cell surface expression on either normal activated and malignant B-cells coincided with the enhancement of DPP IV activity detected on the surface of these cells. Reverse transcription polymerase chain reaction analyses showed that the transcript levels of the CD26 gene was higher in normal activated B-cells and B-CLL cells than in resting B-cells, suggesting that CD26 was expressed at the level of transcriptional activation. These observations provide evidence of the abnormal expression of DPPIV/CD26 in B-CLL which, therefore, may be considered as a novel marker for B-CLL. Further investigation in relation to CD26 expression and other B malignancies needs to be defined.

A novel photosensitizer, 2-butylamino-2-demethoxy-hypocrellin A (2-BA-2-DMHA). 1. Synthesis of 2-BA-2-DMHA and its phototoxicity to MGC803 cells

The reaction of hypocrellin A (HA) with n-butylamine in pyridine under reflux leads to the formation of 2-butylamino-2-demethoxy-hypocrellin A (2-BA-2-DMHA), which is illustrated by ultraviolet-visible absorption spectra, proton nuclear magnetic resonance spectra, infrared spectra and mass spectra. The product exhibits stronger red-light absorption and has a much higher photopotentiation factor than HA (i.e., more than 200 versus four at a dose of 4 J cm-2 of red light on human gastric adenocarcinoma MGC803 cells). The mechanism of phototoxicity of 2-BA-2-DMHA on MGC803 cells irradiated with red light (lamada = 600-700 nm) has also been studied. An examination of extracted cellular DNA by agarose gel electrophoresis shows that the DNA has degraded into fragments with lengths which are multiples of approximately 180-190 base pairs (i.e., oligonucleosome size), a biochemical marker of apoptosis. Transmission electron microscopy reveals chromatin condensation around the periphery of the nucleus, which is also characteristic of apoptosis. This study suggests that 2-BA-2-DMHA is a potential photosensitizer and that its photoxicity to MGC803 cells proceeds via apoptosis.

Function of Semliki Forest virus E3 peptide in virus assembly: replacement of E3 with an artificial signal peptide abolishes spike heterodimerization and surface expression of E1

The Semliki Forest virus spike glycoproteins E1 and p62 form a heterodimeric complex in the endoplasmic reticulum (ER) and are transported as such to the cell surface. In the mature virus particle, the heterodimeric association of E1 and E2 (the cleavage product of p62) is maintained, but as a more labile and acid-sensitive oligomer than the E1-p62 complex. The E3 peptide forms the N-terminal part of the p62 precursor and carries the signal for the translocation of p62 into the lumen of the ER. The question of whether E3 is also important in the formation and stabilization of the E1-p62 heterodimer has been addressed here with the aid of an E3 deletion mutant cDNA. In this construct, the entire E3 was replaced with a cleavable, artificial signal sequence which preserved the membrane topology of an authentic E2. The E3 deletion, when expressed via a recombinant vaccinia virus, abolished heterodimerization of the spike proteins. It also resulted in the complete retention of E1 in the ER and almost total inhibition of E2 transport to the plasma membrane. The oligomerization and transport defect of E1 expressed from the E3 deletion mutant could be complemented with a wild-type p62 provided from a separate coding unit in double infections. These results point to a central role of E3 in complex formation and transport of the viral structural components to the site of budding. In conjunction with earlier work (M. Lobigs and H. Garoff, J. Virol. 64:1233-1240, 1990; J. Wahlberg, W. A. M. Boere, and H. Garoff, J. Virol. 63:4991-4997, 1989), the data support a model of spike protein oligomerization control of Semliki Forest virus assembly and disassembly which may be mediated by the presence of E3 in the uncleaved p62 precursor and release of E3 after cleavage.

Assignment of Clostridium bryantii to Syntrophospora bryantii gen. nov., comb. nov. on the basis of a 16S rRNA sequence analysis of its crotonate-grown pure culture

The Clostridium bryantii-Methanospirillum hungatei syntrophic coculture, grown on caproate, was adapted to grow on crotonate. Then, C. bryantii was isolated in pure culture from crotonate bottle plates. A 16S rRNA sequence analysis of the pure subculture revealed that, as a member of the gram-positive phylum, it was not closely related to any of the Clostridium species with which it was compared or to any of the other clusters in the gram-positive phylum with which it was compared. However, it was closely related to another syntrophic fatty acid-degrading bacterium, Syntrophomonas wolfei. On the basis of its phylogeny, physiology, and cell wall ultrastructure, we propose assignment of C. bryantii to Syntrophospora bryantii gen. nov., nov. comb.

Characteristics of methanogens isolated from bovine rumen

Six strains of methanogens were isolated from 10(-8) and 10(-9) ml of bovine rumen contents. All strains had the morphologic and physiologic characteristics of Methanobrevibacter spp. Four strains required coenzyme M; two did not. Growth of all strains either depended on or was stimulated by a mixture of isobutyric, isovaleric, 2-methylbutyric, and valeric acids. None of the strains reacted with antiserum against the type strain of Methanobrevibacter ruminantium.

Phrenic nerve injury complicating closed cardiovascular surgical procedures for congenital heart disease

Phrenic nerve injury (PNI) with resulting hemidiaphragmatic paralysis occurred in 19 (2.1 +/- 0.5%) of 891 closed cardiac surgical procedures during a twenty-three-year period. Diagnosis was confirmed by standard radiographic criteria. Phrenic nerve injury was most commonly noted following systemic-pulmonary artery anastomosis, ligation of persistent ductus arteriosus plus pulmonary artery banding, and atrial septectomy. Most patients were managed conservatively (nasotracheal or orotracheal intubation and positive end-expiratory pressure). Although no deaths were a direct result of PNI, major complications occurred in 15 of the 19 instances of PNI (79% +/- 10%). The serious morbidity and the hospital costs associated with this complication, however, underscore the cardinal importance of prevention. If injury does occur, early surgical intervention (diaphragmatic plication) in very young infants may reduce the attendant morbidity, but the complete role of diaphragmatic plication remains to be defined.

Surgical repair of tetralogy of Fallot. Long-term follow-up with particular emphasis on late death and reoperation

Early and late results in 309 patients undergoing repair of tetralogy of Fallot between 1960 and 1982 were analyzed with respect to independent determinants of operative mortality, late reoperation, and late death. Follow-up extended to 22 years and totaled 2,743 patient-years. The operative mortality rate was 4.9% +/- 1.3%. Multivariate logistic regression analysis revealed that only young age, long cardiopulmonary bypass time, and (probably) extent of right ventricular outflow tract patch were independent significant determinants of operative mortality. Patients who required a transannular right ventricular outflow tract patch and those who underwent repair without any outflow tract patch were at higher risk than those who received a separate right ventricular and/or pulmonary artery patch. The long-term results were highly satisfactory: Only 15% +/- 3% of patients required reoperation 13 years postoperatively, and 85% +/- 4% of discharged patients were alive 16 years later. Time-dependent linear stepwise multivariate discriminant analysis showed that extent of right ventricular outflow tract patch (transannular greater than none greater than right ventricular and/or [separate] pulmonary arterial), longer ischemic arrest time, previous palliative shunt, and primary suture closure of the ventricular septal defect were the only covariates that independently portended a higher likelihood of reoperation. Similarly, only older age, absence of hypoxic spells, and reoperation were significantly and independently related to the probability of late death. The results of these analyses demonstrate that intracardiac repair of tetralogy is a durable procedure for upwards of 20 years; however, high-risk subsets of patients can be identified in terms of operative mortality, reoperation, and late death. Thus, there is still a need for improvement, particularly future research devoted to better understanding of the electrophysiological mechanisms responsible for arrhythmias, electrosurgical and medical arrhythmia therapy, and right and left ventricular mechanics after repair of tetralogy of Fallot.

Aneurysmal degeneration of Blalock-Taussig shunts: identification and surgical treatment options

Many Blalock-Taussig shunts (subclavian to pulmonary artery anastomoses) have been created and a significant number are still being done. Two cases of aneurysmal degeneration of a Blalock-Taussig shunt and their management are described. Development of this rare complication may be related to large shunt flow and long duration. Large, symptomatic or enlarging aneurysms should be repaired and smaller ones studied by serial computed axial tomography. A simple and safe approach to correct this lesion is division and oversewing of the proximal subclavian artery through an anterior approach, assuming adequate pulmonary blood flow is already present or can be established concomitantly.