Associations of GATA4 genetic mutations with the risk of congenital heart disease: A meta-analysis

BACKGROUND

GATA4 gene is a cardiac transcriptional factor playing important role in cardiac formation and development. Three GATA4 gene mutations, 99 G>T, 487 C>T, and 354 A>C, have been reported in congenital heart disease (CHD). Therefore, a meta-analysis was performed to explore the associations between 99 G>T, 487 C>T, or 354 A>C mutations and the risk of CHD.

METHODS

We searched the relevant studies in electronic databases, including ISI Science Citation Index, Embase, PubMed, CNKI, and Wan fang, from January 2006 to March 2016. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the associations between 99 G>T, 487 C>T, or 354 A>C mutations and the risk of CHD.

RESULTS

A total of 11 studies including 2878 CHD cases and 3339 controls were evaluated. There was no significant association between GATA4 99 G>T (OR = 1.22, 95% CI = 0.74-2.01, P = .43) or 487 C>T (OR = 1.16, 95% CI = 0.48-2.78, P = .74) mutations and the risk of CHD, whereas GATA4 354 A>C (OR = 1.49, 95% CI = 1.15-1.93, P = .003) mutation was significantly associated with CHD risk. Subgroup analysis was further performed for GATA4 99 G>T, 487 C>T, and 354 A>C mutations based on sample size and ethnicity, and no significant association between GATA4 99 G>T or 487 C>T mutations and the risk of CHD was found in all subgroups, whereas GATA4 354 A>C mutation was significantly associated with CHD risk in large-sample-size and Asian subgroups. However, subgroup analysis by types of CHD indicated that there was no significant association between GATA4 354 A>C mutation and the risk of ventricular septal defects.

CONCLUSIONS

Our findings suggested that GATA4 99 G>T and 487 C>T mutations may not be related to the incidence of CHD. However, GATA4 354 A>C mutation was significantly associated with CHD risk.

CRISPR/Cas9-loxP-Mediated Gene Editing as a Novel Site-Specific Genetic Manipulation Tool

Cre-loxP, as one of the site-specific genetic manipulation tools, offers a method to study the spatial and temporal regulation of gene expression/inactivation in order to decipher gene function. CRISPR/Cas9-mediated targeted genome engineering technologies are sparking a new revolution in biological research. Whether the traditional site-specific genetic manipulation tool and CRISPR/Cas9 could be combined to create a novel genetic tool for highly specific gene editing is not clear. Here, we successfully generated a CRISPR/Cas9-loxP system to perform gene editing in human cells, providing the proof of principle that these two technologies can be used together for the first time. We also showed that distinct non-homologous end-joining (NHEJ) patterns from CRISPR/Cas9-mediated gene editing of the targeting sequence locates at the level of plasmids (episomal) and chromosomes. Specially, the CRISPR/Cas9-mediated NHEJ pattern in the nuclear genome favors deletions (64%–68% at the human AAVS1 locus versus 4%–28% plasmid DNA). CRISPR/Cas9-loxP, a novel site-specific genetic manipulation tool, offers a platform for the dissection of gene function and molecular insights into DNA-repair pathways.

Clinical features and genetic diagnosis of hereditary spinocerebellar ataxia 3

Spinocerebellar ataxia type 3 (SCA3) is a rare inherited autosomal dominant progressive neurological disorder, which results from a CAG‑repeat expansion in the gene encoding the deubiquitinating enzyme, ataxin‑3. At present, no effective treatment is available for this fatal disorder; however, certain studies have suggested that reducing the levels of mutant ataxin‑3 protein may reverse or halt the progression of disease in patients with SCA3. In the present study, clinical examinations were performed on a patient with SCA3 who exhibited disease features including coughing, expectoration and was bedridden with mobility limitation. CAG repetitions at SCA‑associated genes were detected in the patient's family by performing standard polymerase chain reaction (PCR) and triple‑repeat primed PCR. The numbers of CAG‑repeats within the two alleles of the gene of interest in the patient were 15 and 78. Notably, the patient's brother, who harbored 76 CAG‑repeats in one allele of the gene of interest, did not exhibit severe disease symptoms. These results suggest that the number of CAG‑repeats is a critical for determination of SCA3 disease severity and time of onset. In addition, the defined phenotypic characteristics of the patient in the present study provide useful insight for more accurate clinical diagnosis and genotyping of future patients.

Mapping QTLs for drought tolerance in an F2:3 population from an inter-specific cross between Gossypium tomentosum and Gossypium hirsutum

Cotton is one of the most important natural fiber crops in the world. Its growth and yield is greatly limited by drought. A quantitative trait locus (QTL) analysis was therefore conducted to investigate the genetic basis of drought tolerance in cotton (Gossypium spp) using 188 F2:3 lines developed from an inter-specific cross between a wild cotton species, G. tomentosum, and an upland cotton, G. hirsutum (CRI-12). A genetic map was constructed using 1295 simple sequence repeat markers, which amplified 1342 loci, distributed on 26 chromosomes, covering 3328.24 cM. A field experiment was conducted in two consecutive years (2014 and 2015) and 11 morphological and physiological traits were recorded under water-limited (W1)/well-watered (W2) regimes at three growth stages (bud, flowering, and full boll). The traits measured included chlorophyll content, plant height, leaf area, leaf number, leaf fresh weight, leaf dry weight, boll weight, number of bolls per plant, and the number of fruiting branches. Sixty-seven and 35 QTLs were found under the W1 and W2 conditions, respectively. Of these, the majority exhibited partial dominance or over-dominance genetic effects for increasing the trait values. Four consistent QTLs were found under the W1 treatment on chromosomes 5, 8, 9, and 16, whereas no consistent QTL was found in W2. Thirteen QTL clusters were also identified on nine chromosomes (2, 3, 5, 6, 9, 14, 15, 16, and 21). These results will help to elucidate the genetic basis of drought tolerance in cotton.

[Transapical transcatheter aortic valve replacement for high risk elderly patients with predominant aortic incompetence]

OBJECTIVES

To introduce the application of the J-Valve™ system in elderly patients with predominant aortic incompetence without significant valve calcification, and to evaluate its feasibility.

METHODS

From April 2014 to July 2015, 33 cases of transapical implantation of J-Valve™ were performed in Department of Cardiac Surgery, Zhongshan Hospital, Fudan University. Sixteen of these patients were diagnosed as predominant aortic incompetence without significant valve calcification. There were 11 male and 5 female patients aged from 61 to 84 years, with a mean age of (76±6) years. All patients had symptoms of left ventricular dysfunction for at least 3 months. They were considered to be prohibitive for surgical valve replacement (logistic European system for cardiac operative risk evaluation: 22.2% to 44.4%, mean 27%±6% after evaluation by an interdisciplinary heart team. The J-Valve™ system was applied in transapical transcatheter aortic valve replacement for patients. The multi-slice CT was performed before discharge. Clinical evaluation including patients' history, symptoms and New York Heart Association classification and echocardiogram evaluation were performed before discharge, 1(st) month, 3(th) month and 12(th) month after the operation respectively.

RESULTS

Implantations were successful in all patients. One patient died from moderate paravalvular leak which led to multi-organ failure during the hospital stay. The mean time of postoperative hospital stay of the other 15 patients was (6.1±1.3) days. The 15 patients were followed by 174 to 410 days, with a median time of 188 days. Only two patients had trivial prosthetic valve incompetence, the other 13 patients had no prosthetic valve incompetence; two patients had no paravavular leak and the other 13 patients had paravavular leak of no more than moderate grade. There were no major complication or mortality during the follow-up.

CONCLUSIONS

The transapical implantation of the J-Valve™ system in high risk elderly patients with predominant aortic incompetence is feasible.The early postoperative outcome is satisfactory.

[Analysis of the association of human leukocyte antigen DQ gene polymorphisms with unexplained recurrent spontaneous abortion among ethnic Han Chinese from Wenzhou region]

OBJECTIVE

To assess the association of human leukocyte antigen DQ gene polymorphisms with unexplained recurrent spontaneous abortion (URSA) among ethnic Han Chinese from Wenzhou region.

METHODS

Fifty couples with URSA (URSA group) and 66 couples with normal pregnancy history (control group) were recruited. The alleles of HLA-DQA1 and HLA-DQB1 were analyzed by polymerase chain reaction with specific sequence primers (PCR-SSP) in all subjects. The frequency distribution of HLA-DQ alleles, odds ratios (OR) between each group and sharing of HLA-DQ alleles were calculated.

RESULTS

The frequency distribution of HLA-DQB1*03:03 allele in the females with URSA was significantly higher than that healthy females (21.00% vs. 9.85%, OR=2.433, 95%CI: 1.232-4.894, χ(2)=5.657, P<0.05). The HLA-DQB1*05:03 allele was present among the healthy females with a frequency of 3.03%, and was not detected among females with URSA. For both males and females, the HLA-DQB1*05:02 allele were only typed in control group with frequencies of 6.06% and 5.30%, respectively. The sharing of HLA-DQA1 alleles in couples with URSA was increased compared with the control group (70.27% vs. 44.64%, OR=2.931, 95%CI: 1.216-7.067, P<0.05).

CONCLUSION

The increased sharing of HLA-DQA1 alleles may contribute to the susceptibility of URSA among ethnic Han Chinese from Wenzhou region. The allele of HLA-DQB1*03:03 in the females may be predisposing factor for URSA. However, the HLA-DQB1*05:02 allele in both gender and HLA-DQB1*05:03 allele in females may confer a protective effect.

Successful ABO-incompatible living-related intestinal transplantation: a 2-year follow-up

ABO-incompatible intestinal transplantation has rarely been performed due to poor patient outcomes. Herein we present a case of successful ABO-incompatible intestinal transplantation with a 2-year follow-up. A 16-year-old female with a history of extensive bowel resection received an ABO-incompatible living donor bowel graft from her father (blood type AB graft into a type A recipient). Posttransplant immunosuppression consisted of an initial anti-CD20, plasmapheresis/intravenous immunoglobulin before transplantation, followed by an anti-thymocyte globulin (ATG) induction and splenectomy, and maintenance with tacrolimus and prednisone. Her postoperative course was remarkable for a single episode of rejection on day 14 which responded promptly to treatment with methyprednisolone and ATG. Three months after transplantation, the patient developed an abdominal abscess requiring open surgical drainage. No viral infections were encountered. Posttransplant anti-B antibody titers and anti-B7 donor-specific antibody levels remained low. At a 2-year follow-up, the patient showed a progressive weight gain of 5.0 kg. This case illustrates that ABO-incompatible living-related bowel transplantation is immunologically feasible and is associated with good outcomes for the recipient. The management of blood type antibodies and the use of adequate immunosuppression in the early period of the procedure may be the keys to the success of future cases.

The changes of platelet and platelet activation markers in acute coronary syndrome patients

BACKGROUND

To investigate the changes of platelet microparticle (PMPs), monocyte-platelet aggregation (MPAs), and the platelet membrane glycoprotein GPIIb/IIIa ligands (PAC-1) and P-hormone (CD62P) activation ratio changes in acute coronary syndrome (ACS) patients.

METHODS

92 patients were divided into ACS group (54 cases) and coronary angiography negative group (38 cases). 30 cases of age/gender matched healthy control group were recruited. The flow cytometry analysis in each group of PMPs, the MPAs expression of CD62P, GPIIb/IIIa activation ratio, and ROC curve were performed to evaluate the sensitivity and specificity of each parameter.

RESULTS

The healthy control group showed MPAs 5.94 +/- 1.93%, PMPs 1.89 +/- 0.53%, and PAC-1 2.86 +/- 0.93%, the coronary angiography-negative group showed MPAs 11.97 +/- 4.92%, PMPs 3.08 +/- 1.38%, and PAC-1 3.38 +/- 0.92%, and the ACS group showed MPAs 46.27 +/- 17.74%, PMPs 5.28 +/- 2.44%, and PAC-1 5.34 +/- 2.44%. In the ACS group, the area under the ROC curve of each indicator for identifying suspected ACS patients were MPAs (0.952), PMPs (0.807), PAC-1 (0.770), and CD62p (0.656). MPAs showed the highest sensitivity (94.4%) and specificity (84.2%) for the diagnosis of ACS.

CONCLUSIONS

acute coronary syndrome, platelet microparticle, monocyte-platelet aggregation, CD62P, GPIIb/IIIa.

Establishing a conceptual model for photochemical ozone pollution in subtropical Hong Kong

Photochemical ozone (O₃) formation is related to its precursors and meteorological conditions. A conceptual model of O₃ air pollution is developed based on the analysis of data obtained at Tung Chung (TC) in Hong Kong. By comparing meteorological parameters between O₃ and non-O₃ episode days, it was found that high temperatures, strong solar radiation, low wind speeds and relative humidity, northeasterly and/or northwesterly prevailing winds were favorable for the O₃ formation, while tropical cyclones were most conducive to the occurrence of O₃ episodes. Backward trajectories simulation and graphical illustration of O₃ pollution suggested that super-regional (i.e. central and eastern China) and regional (i.e. Pearl River Delta, southern China) transport was another factor that contributed to high O₃ levels in Hong Kong. The photochemical O₃ formation, generally VOC-limited in Hong Kong, was controlled by a small number of volatile organic compounds (VOCs). Furthermore, the positive matrix factorization (PMF) simulation suggested that solvent usage and vehicular emissions are the major contributors to ambient VOCs in Hong Kong. Finally, this paper presents recommendations for further O₃ research and implementation of O₃ control strategies.

mirTools 2.0 for non-coding RNA discovery, profiling, and functional annotation based on high-throughput sequencing

Next-generation sequencing has been widely applied to understand the complexity of non-coding RNAs (ncRNAs) in a cost-effective way. In this study, we developed mirTools 2.0, an updated version of mirTools 1.0, which includes the following new features. (1) From miRNA discovery in mirTools 1.0, mirTools 2.0 allows users to detect and profile various types of ncRNAs, such as miRNA, tRNA, snRNA, snoRNA, rRNA, and piRNA. (2) From miRNA profiling in mirTools 1.0, mirTools 2.0 allows users to identify miRNA-targeted genes and performs detailed functional annotation of miRNA targets, including Gene Ontology, KEGG pathway and protein-protein interaction. (3) From comparison of two samples for differentially expressed miRNAs in mirTools 1.0, mirTools 2.0 allows users to detect differentially expressed ncRNAs between two experimental groups or among multiple samples. (4) Other significant improvements include strategies used to detect novel miRNAs and piRNAs, more taxonomy categories to discover more known miRNAs and a stand-alone version of mirTools 2.0. In conclusion, we believe that mirTools 2.0 (122.228.158.106/mr2_dev and centre.bioinformatics.zj.cn/mr2_dev) will provide researchers with more detailed insight into small RNA transcriptomes.

Polymorphic microsatellite loci for the genetic analysis of Lycoris radiata (Amaryllidaceae) and cross-amplification in other congeneric species

Lycoris radiata is a perennial herb that has been used in traditional Chinese medicine for a long time and has two main medicinal components in its bulb, lycorine and galanthamine. However, the original microsatellite loci have not been developed for any species of Lycoris. Total genomic DNA was extracted from fresh bulbs using a modified CTAB protocol. We isolated 10 microsatellite loci from 21 L. radiata individuals of a natural population from Yellow Mountain in Anhui Province, China. The number of alleles ranged from two to nine. The observed and expected heterozygosities ranged from 0.238 to 0.952 and from 0.455 to 0.784, respectively. One locus significantly deviated from Hardy-Weinberg equilibrium and no significant linkage disequilibrium was found between pairs of loci. Cross-species amplification of these microsatellite loci was characterized in additional five species (L. sprengeri, L. anhuiensis, L. albiflora, L. longituba, and L. chinensis) of Lycoris. The results suggest that these microsatellite markers would contribute to the population genetic studies of L. radiata and other related species.

Identification of compound heterozygous mutations in the ITGA2B gene in a Chinese patient with Glanzmann thrombasthenia

BACKGROUND

Glanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder characterized by the tendency to hemorrhage and the inability of platelets to aggregate in response to agonists. GT is caused by a defect of the platelet glycoprotein IIb/IIIa complex. The objective of this study was to describe the clinical features and the genetic cause of GT in a 6-year-old girl from south China.

METHODS

A three-generation family was studied. The proband patient aged 6 years and her parents undertook examinations of platelet counts, blood film, bleeding time, platelet aggregation, and flow cytometry. All coding exons of the ITGA2B and ITGB3 genes were amplified by polymerase chain reaction (PCR), and direct sequencing was performed for mutational screening on the patient and normal controls consisted of 52 healthy blood donors. Reverse transcription PCR was conducted to test for exon skipping.

RESULTS

The proposita patient showed dispersing platelets, prolonged bleeding time, and severely reduced platelet aggregation in response to the physiological agonists adenosine diphosphate (ADP), epinephrine, collagen, and ristocetin. Flow cytometric measurements showed that the contents of alphaIIb and beta3 were significantly decreased. Sequencing results demonstrated two different types of heterozygous mutations existed in the alphaIIb gene (c.2930delG and IVS15-1delG). The compound mutations were also confirmed in the patient's mother and father separately.

CONCLUSIONS

The alphaIIbbeta3 deficiency of the proband was caused by two compound ITGA2B mutations, which were first reported in Chinese GT patients. The IVS15-1delG was first confirmed to cause an exon skipping.

[Hereditary hemorrhagic telangiectasia resulted from a nonsense mutation Arg479 Stop in the ALK-1 gene]

OBJECTIVE

To identify the gene mutations in a pedigree with hereditary hemorrhagic telangiectasia.

METHODS

Genomic DNA was extracted from the peripheral blood of the propositus. All of the exons, intron/exon boundaries and the 5' untranslation regions (UTR) of the ALK-1 and endoglin gene were amplified by polymerase chain reaction (PCR). The PCR products were screened by direct sequencing.

RESULTS

The mutation is a C1437T substitution in exon 10 of the ALK-1 gene, resulting in Arg 479 Stop.

CONCLUSION

The hereditary hemorrhagic telangiectasia propositus is caused by a heterozygous Arg 479 Stop mutation in the ALK-1 gene which has not been identified previously.

Pulmonary peptide delivery: effect of taste-masking excipients on leuprolide suspension metered-dose inhalers

The purpose of this study was to evaluate the effect of taste-masking excipients on in vitro and in vivo performance of a leuprolide metered-dose inhaler (MDI) suspension formulation. Taste-masking excipients (aspartame and menthol) were added to a leuprolide suspension MDI formulation. The leuprolide MDI formulation with the taste-masking excipients was characterized in terms of milling time, particle size distribution, dose delivery and uniformity, and drug absorption in dogs. The data were compared with a formula that did not contain taste-masking excipients. It was found that the longer milling time for the leuprolide suspension with the taste-masking excipients was required to obtain a similar particle size distribution compared with the formula without taste-masking excipients using a fluid energy mill. Although measurable differences in mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) were not observed between the two formulations, the percent of particles < or = 5 microns and the actuator retention for the formula with the taste-masking excipients were significantly different from the formula without taste-masking excipients using the Marple-Miller cascade impactor. Taste-masking excipients did not show a significant effect on valve delivery and through-can dose uniformity. However, the mean ex-actuator dose was 150.4 mg for the formula with the taste-masking excipients and 162.2 mg for the reference formula, respectively, indicating a significant difference. In tracheostomized dogs, both formulations showed comparable pharmacokinetic parameters including Cmax, Tmax, AUC0-12 and bioavailability (F%), indicating that the taste-masking excipients do not have an effect on lung absorption of leuprolide acetate. Therefore, inclusion of taste-masking excipients in the leuprolide MDI suspension formulation showed a significant impact on drug micronization, exactuator dose, and particle deposition pattern. Mechanistically, the unfavorable performance of leuprolide MDI in the presence of taste-masking excipients could be due to modification of the properties of the suspension itself and alteration of propellant evaporation following actuation.

[Cloning of cancer-related genes of Rat6 fibroblasts by using an improved differential display method]

The p53 gene is the most frequently mutated gene identified so far in human cancers. When a mutant p53(135)-val gene was allowed to be over-expressed in Rat6(R6) cells, a high incidence of spontaneous transformation was observed in long-term culture of this cell line(R6 # 13-8). To identify genes involved in cell transformation, parental p53 over-expressing cell, R6 # 13-8, and its spontaneous transformant T2, were analyzed by an improved mRNA differential display technique, which was reproducible, simpler, and was able to clone cDNA longer than 500 bp, and was with less false positives. When 33 10-mer or 12-mer single primers with arbitrary but defined sequence were used for PCR, over 90 discrete cDNAs were obtained from R6 # 13-8 and T2 cells. Three differentially expressed cDNAs were identified, one of them is highly expressed in T2 cells, while the other two, 0.8 kb and 0.9 kb long, are highly expressed in R6 # 13-8 cells. The latter were cloned and confirmed by Northern hybridization. Both cloned fragment were not homologous with any published sequence. Our results suggest that the activation and inactivation of genes are involved in the process of the spontaneous transformation from R6 # 13-8 to T2.

Differentiating normal from abnormal inferior thoracic paravertebral soft tissues on chest radiography in children

OBJECTIVE

The purposes of this investigation were to define the normal appearances, define factors that have the potential to influence appearance, and establish defined criteria to differentiate normal from abnormal appearances of posteroinferior paravertebral soft tissues on chest radiography in children.

SUBJECTS AND METHODS

Paravertebral soft tissues were evaluated on frontal chest radiographs in 23 children with documented abnormalities and 275 children without abnormalities in the region. The frequency of visualization, course, width, and factors (patient positioning, age, and sex) potentially influencing the appearance of paravertebral soft tissues were determined. Inferolateral course and width greater than that of the adjacent pedicle were evaluated as criteria for abnormality.

RESULTS

Only 28% of the children without abnormalities had paravertebral soft tissues visualized, and the frequency of visualization directly increased with age (p = 0.001). For identification of abnormal cases on the left side, width greater than the adjacent pedicle had a sensitivity of 100% and a specificity of 98%, and inferolateral course had a sensitivity of 86% and a specificity of 95%. Visualization on the right side (n = 5) was always abnormal. Six normal cases had a width greater than that of the adjacent pedicle on the left side on initial radiographs obtained with supine positioning and met normal criteria on repeated radiographs with upright positioning.

CONCLUSION

Width greater than the adjacent pedicle is the best radiographic criterion for differentiation of abnormal from normal left-sided paravertebral soft tissues, particularly on radiographs obtained with upright positioning. Identifiable right-sided paravertebral soft tissue is always abnormal. These criteria are useful aids in determining the need for additional imaging, such as CT.

Identification and characterization of genes whose expressions are altered in rat 6 fibroblasts transformed by mutant p53(val135)

The wild-type tumor suppressor gene p53 is known as a transcription factor in activating or suppressing target genes that encode proteins in regulating genome stability, DNA damage, cell arrest, and apoptosis. However, the role of mutant p53 in the process of cell transformation is still unclear. Our recent work indicated that overexpression of mutant p53(val135) induced high incidence of spontaneous transformation in prolonged cultures of Rat 6 fibroblasts. In order to identify genes related to neoplastic transformation induced by the mutant p53, the p53(val135)-overexpressor R6#13-8 and its derived spontaneously transformed cell line T2 were analyzed by mRNA differential display. In a systematic screening with 80 primer sets of RT-PCR reactions, three genes were found to be differentially expressed between R6#13-8 and T2 cells. Two genes, identified as homologues of the growth factor inducible immediate-early gene Cyr61 and the human nonmuscle myosin heavy chain-B, were down-regulated in T2 cells. Interestingly, both genes were also suppressed in Rat 6 cells transformed by c-H-ras and v-myc, but not by v-src genes. The third gene is a homologue of the frizzled related protein, a gene family that acts, in some cases, as an antagonist to the Wnt signaling pathway. It is intriguing that the rat homologue of the frizzled related protein was only expressed in p53(val135)-overexpressing cells, but not in the parental Rat 6 cells. However, the same gene was also highly expressed in ras-transformed Rat 6 cells, and moderately expressed in v-src-transformed Rat 6 cells. This is the first study in which the association of mutant p53 to these three genes is revealed. Our current report may provide new clues to the role of mutant p53 in the process of cell transformation.

Optimizing contrast-enhanced abdominal CT in infants and children using bolus tracking

OBJECTIVE

Manual administration of IV contrast material results in unpredictable injection rates. Our purpose was to determine the effect of bolus tracking on overall abdominal helical CT scan quality, particularly on hepatic enhancement, in children with manually administered contrast media.

MATERIALS AND METHODS

We compared 33 abdominal helical CT scans of 29 children in whom bolus tracking was used with 22 CT scans of a control group of 21 children in whom bolus tracking was not used. All contrast material was administered by manual injection. Qualitative assessment was made of organ and vessel enhancement and overall scan appearance. Quantitative assessment using region-of-interest cursors was performed at three anatomic levels, and the results for the two groups of children were compared.

RESULTS

Qualitative comparison of enhancement parameters between the bolus tracking group (number given first) and the control group (number given second) yielded the following: splenic artifact in 9% versus 23% (p = .24); inferior vena cava flow artifact in 3% versus 27% (p = .01); scanning during the nephrographic phase in 89% versus 59% (p = .02); and good quality grade in 79% versus 64% (p = .23). Significantly greater hepatic enhancement (as measured in mean Hounsfield units) was achieved in the bolus tracking group than in the control group at the superior (48.5 versus 28.6; p < .001), middle (47.9 versus 32.3; p < .001), and inferior (48.2 versus 36.5; p = .01) levels. Hepatic enhancement increased significantly from the superior to the inferior level in the control group (p < .02), whereas enhancement was homogeneous in the bolus tracking group (p > .50).

CONCLUSION

Bolus tracking provides improved contrast enhancement, including significantly greater hepatic enhancement, during abdominal helical CT in children in whom the rate of injection of contrast material is unpredictable.

[Molecular cloning of two Rab family proteins, S2 and S10]

Rab family proteins play important roles in vesicular transport. In mammals, more than 30 members of this family have been reported to date. I report here the cDNA cloning and analysis of the genomic organization of two Rab family proteins, S2 and S10. Mouse S2 cDNA was isolated from a spleen cDNA library. S2 encoded a novel Rab family protein with highest homology to human S10. Mouse S10 cDNA was isolated from a brain cDNA library. Mouse S10 was 92% homologous at the nucleotide level and 98% identical at the amino acid level to human S10. The amino acid sequences of mouse S2 and S10 were 55% identical, and these two proteins shared unique amino acid sequences at the effector domain. Mouse S2 and S10 genes were isolated from a genomic library. The genomic organization of these two genes was essentially identical, having two exons and a single intron. This structure was unique among reported rab family genes. These findings suggest that S2 and S10 would make a subgroup in Rab family. The phylogenetic tree made by a computer program was consistent to this idea. Northern blotting of mouse tissue RNAs indicated that S2 gene was expressed ubiquitously, whereas S10 gene was almost exclusively expressed in the brain. These results suggest that S2 and S10 play similar roles in vesicular transport, whereas S10 has more specialized function in the nervous system.

A novel Rab GTPase, Rab33B, is ubiquitously expressed and localized to the medial Golgi cisternae

Small GTP-binding proteins of the Rab family play important roles at defined steps of vesicular transport in protein secretion and the endocytosis pathway. In mammals, more than 30 proteins belonging to the Rab family have been reported to date. We report here the molecular cloning and characterization of a novel Rab protein, Rab33B. The amino acid sequence of Rab33B shows 55.3% identity to the Rab33A protein (previously called S10), and these two proteins share unique amino acid sequences at the effector domain. The genomic organization of rab33B was the same as rab33A: it consists of two exons. Thus, these two proteins make a subclass within the Rab family. Northern blot analysis showed that rab33B is expressed ubiquitously in mouse tissues, in contrast to rab33A whose expression is restricted to the brain and the immune system. A 26 kDa protein was detected by western blotting using a Rab33B-specific monoclonal antibody. Using immunofluorescence studies, Rab33B was shown to co-localize with (alpha)-mannosidase II, a Golgi-specific marker. Immunoelectron microscopy analysis further defined the localization of Rab33B to the medial Golgi cisternae. These results suggest Rab33B plays a role in intra-Golgi transport.

Structure and expression of the mouse S10 gene

We previously reported the cloning of a human S10 cDNA which encodes a small GTP-binding protein belonging to the Rab subfamily. Here we describe a mouse S10 cDNA and its genomic structure. Mouse S10 is 92.3% homologous at the nucleotide level and 98.3% identical at the amino acid level compared to human S10. The mouse S10 gene is comprised of two exons and a single intron. Northern blotting of tissue RNAs indicates that the S10 gene is predominantly expressed in brain.

Review of pneumatic reduction of intussusception: evolution not revolution

Pneumatic insufflation of the colon for reduction of pediatric intussusception has recently been recognized in the United States as an alternative method for the more traditional hydrostatic reduction with contrast material. The experience with pneumatic reduction in China is extensive; more than 14,000 cases have been reported in the English language literature. In this review, the general technique used in China is summarized, and the international experience with air insufflation is included in a comparison of hydrostatic and pneumatic reduction techniques.

Fluorescent banding pattern analysis of eight taxa of Phaseolus and Vigna in relation to their phylogenetic relationships

Phylogenetic relationships among eight taxa of seven species of Phaseolus and Vigna (Phaseolus angularis, P. aureus, P. calcaratus, P. coccineus, P. vulgaris, Vigna sesquipedalis and V. sinensis; 2n = 22 each) were studied by the fluorescent chromosome banding technique. Preparations of somatic metaphase chromosomes of each taxon were sequentially stained with Giemsa, GC-specific fluorochrome chromomycin A3 (CMA) and AT-specific fluorochrome 4'-6-diamidino-2-phenylindole (DAPI). On the basis of the fluorescent banding patterns of the 22 chromosomes of each taxon, P. angularis, P. coccineus (from China and Korea) and P. vulgaris were grouped into one group ("Phaseolus group"), P. aureus and two Vigna species were grouped into another ("Vigna group") and P. calcaratus was grouped in an independent group.