The Reduced Gut Lachnospira Species Is Linked to Liver Enzyme Elevation and Insulin Resistance in Pediatric Fatty Liver Disease

The objective of this study was to investigate gut dysbiosis and its metabolic and inflammatory implications in pediatric metabolic dysfunction-associated fatty liver disease (MAFLD). This study included 105 children and utilized anthropometric measurements, blood tests, the Ultrasound Fatty Liver Index, and fecal DNA sequencing to assess the relationship between gut microbiota and pediatric MAFLD. Notable decreases in Lachnospira spp., Faecalibacterium spp., Oscillospira spp., and Akkermansia spp. were found in the MAFLD group. Lachnospira spp. was particularly reduced in children with MAFLD and hepatitis compared to controls. Both MAFLD groups showed a reduction in flavone and flavonol biosynthesis sequences. Lachnospira spp. correlated positively with flavone and flavonol biosynthesis and negatively with insulin levels and insulin resistance. Body weight, body mass index (BMI), and total cholesterol levels were inversely correlated with flavone and flavonol biosynthesis. Reduced Lachnospira spp. in children with MAFLD may exacerbate insulin resistance and inflammation through reduced flavone and flavonol biosynthesis, offering potential therapeutic targets.

The novel roles of YULINK in the migration, proliferation and glycolysis of pulmonary arterial smooth muscle cells: implications for pulmonary arterial hypertension

BACKGROUND

Abnormal remodeling of the pulmonary vasculature, characterized by the proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) along with dysregulated glycolysis, is a pathognomonic feature of pulmonary arterial hypertension (PAH). YULINK (MIOS, Entrez Gene: 54468), a newly identified gene, has been recently shown to possess pleiotropic physiologic functions. This study aims to determine novel roles of YULINK in the regulation of PAH-related pathogenesis, including PASMC migration, proliferation and glycolysis.

RESULTS

Our results utilized two PAH-related cell models: PASMCs treated with platelet-derived growth factor (PDGF) and PASMCs harvested from monocrotaline (MCT)-induced PAH rats (PAH-PASMCs). YULINK modulation, either by knockdown or overexpression, was found to influence PASMC migration and proliferation in both models. Additionally, YULINK was implicated in glycolytic processes, impacting glucose uptake, glucose transporter 1 (GLUT1) expression, hexokinase II (HK-2) expression, and pyruvate production in PASMCs. Notably, YULINK and GLUT1 were observed to colocalize on PASMC membranes under PAH-related pathogenic conditions. Indeed, increased YULINK expression was also detected in the pulmonary artery of human PAH specimen. Furthermore, YULINK inhibition led to the suppression of platelet-derived growth factor receptor (PDGFR) and the phosphorylation of focal adhesion kinase (FAK), phosphoinositide 3-kinase (PI3K), and protein kinase B (AKT) in both cell models. These findings suggest that the effects of YULINK are potentially mediated through the PI3K-AKT signaling pathway.

CONCLUSIONS

Our findings indicate that YULINK appears to play a crucial role in the migration, proliferation, and glycolysis in PASMCs and therefore positioning it as a novel promising therapeutic target for PAH.

Early-Term Neonates Demonstrate a Higher Likelihood of Requiring Phototherapy Compared to Those Born Full-Term

Early-term neonates (with a gestational age (GA) of 37 and 0/7 weeks to 38 and 6/7 weeks) face higher morbidities, including respiratory and neurodevelopmental issues, than full-term (39 and 0/7 weeks to 40 and 6/7 weeks) infants. This study explores whether hyperbilirubinemia necessitating phototherapy also differs between these groups. A retrospective study was conducted on neonates born from January 2021-June 2022, excluding those with specific conditions. Evaluated factors included GA, birth weight, bilirubin levels, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and feeding type, with phototherapy given as per AAP guidelines. Of 1085 neonates, 356 met the criteria. When stratifying the neonates based on the need for phototherapy, a higher proportion of early-term neonates required phototherapy compared to full-term (p < 0.05). After factoring in various risks (GA; birth weight; gender; feeding type; G6PD deficiency; transcutaneous bilirubin levels at 24 h and 24-48 h postpartum; maternal diabetes; and the presence of caput succedaneum or cephalohematoma), early-term neonates were more likely to need phototherapy than full-term babies (OR: 2.15, 95% CI: 1.21 to 3.80). The optimal cut-off for transcutaneous bilirubin levels 24-48 h postpartum that were used to predict phototherapy need was 9.85 mg/dl. In conclusion, early-term neonates are at a greater risk for developing jaundice and requiring phototherapy than full-term neonates. Monitoring bilirubin 24-48 h postpartum enhances early prediction and intervention.

Kawasaki disease in children with Bacillus Calmette-Guérin scar reactivity: Focus on coronary outcomes

BACKGROUND

/Purpose: Reactivity at the Bacillus Calmette-Guérin (BCG) scar is a pathognomonic feature of Kawasaki disease (KD). However, its value in predicting KD outcomes has not been emphasized. This study explored the clinical significance of BCG scar redness with respect to coronary artery outcomes.

METHODS

This retrospective study collected data on children with KD from 13 hospitals in Taiwan during 2019-2021. Children with KD were categorized into four groups based on the KD type and BCG scar reactivity. Risk factors of coronary artery abnormalities (CAA) were analyzed in all groups.

RESULTS

BCG scar redness occurred in 49% of 388 children with KD. BCG scar redness was associated with younger age, early intravenous immunoglobulin (IVIG) treatment, hypoalbuminemia, and CAA at the first echocardiogram (p < 0.01). BCG scar redness (RR 0.56) and pyuria (RR 2.61) were independent predictors of any CAA within 1 month (p < 0.05). Moreover, pyuria (RR 5.85, p < 0.05) in children with complete KD plus BCG scar redness was associated with CAA at 2-3 months; first IVIG resistance (RR 15.2) and neutrophil levels ≥80% (RR 8.37) in children with complete KD plus BCG scar non-redness were associated with CAA at 2-3 months (p < 0.05). We failed to detect any significant risk factors of CAA at 2-3 months in children with incomplete KD.

CONCLUSION

BCG scar reactivity contributes to diverse clinical features in KD. It can be effectively applied to determine the risk factors of any CAA within 1 month and CAA at 2-3 months.

The joint effect of gestational diabetes mellitus and hypertension contribute to higher risk of diabetes mellitus after delivery: a nationwide population-based study

BACKGROUND

Gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH) are known risk factors for postpartum diabetes mellitus (DM) and hypertension, respectively. This study aimed to examine the association between the co-occurrence of GDM and PIH and the subsequent development of diabetes mellitus (DM), hypertension, and metabolic syndrome.

METHODS

A cohort study was conducted using data from the Taiwan National Health Insurance Research Database (TNHIRD). The study population included 2,297,613 pregnant women with no history of certain medical conditions who gave birth between 2004 and 2015. The women were classified into four cohorts based on their medical history: GDM cohort, PIH cohort, both GDM and PIH cohort, and normal cohort (without GDM and PIH).

RESULTS

The GDM cohort had a higher risk of developing DM, hypertension, and metabolic syndrome than the normal cohort, with hazard ratios of 7.07, 1.54, and 2.51, respectively. The PIH cohort also had an increased risk for these conditions compared with the normal cohort, with hazard ratios of 3.41, 7.26, and 2.68, respectively. The cohort with both GDM and PIH had the highest risk of developing postpartum DM, hypertension, and metabolic syndrome, with hazard ratios of 21.47, 8.02, and 5.04, respectively, compared with the normal cohort.

CONCLUSION

The cohort of patients with both GDM and PIH had the highest impact on developing postpartum DM compared with either condition alone cohort. Furthermore, the co-occurrence of both conditions increases the risk, with a higher likelihood of developing postpartum DM than hypertension or metabolic syndrome.

Changing patterns of infectious diseases in children during the COVID-19 pandemic

Each infectious disease has had its own epidemic pattern and seasonality for decades. However, public health mitigation measures during the coronavirus disease 2019 (COVID-19) pandemic have resulted in changing epidemic patterns of infectious diseases. Stringent measures resulted in low incidences of various infectious diseases during the outbreak of COVID-19, including influenza, respiratory syncytial virus, pneumococcus, enterovirus, and parainfluenza. Owing to the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and subsequent immunity development, decreasing virulence of SARS-CoV-2, and worldwide immunization against SARS-CoV-2 in children beyond 6 months of age, mitigation measures are lifted country by country. Consequently, the immunity debt to infectious respiratory viruses other than SARS-CoV-2 contributed to the "off-season," "see-saw," and "upsurge" patterns of various infectious diseases in children. Moreover, apart from the persistence of SARS-CoV-2, the coexistence of other circulating viruses or bacterial outbreaks may lead to twindemics or tripledemics during the following years. Therefore, it is necessary to maintain hand hygiene and immunization policies against various pathogens to alleviate the ongoing impact of infectious diseases on children.

Cross-protective humoral immunity to coronaviruses from SARS coronavirus 2-naïve sera of children with Kawasaki disease

OBJECTIVES

SARS coronavirus 2 (SARS-CoV-2)-associated multi-system inflammatory syndrome in children indicates that viruses can trigger a Kawasaki disease (KD)-like hyperinflammation. A plausible hypothesis was that coronavirus-specific 'holes' in humoral immunity could cause both diseases.

METHODS

To determine whether SARS-CoV-2-naïve patients with KD have inferior humoral immunity for the novel coronavirus, sera of children with KD and control children from year 2015 to 2021 were subjected to ELISA, microwestern, and neutralization assays to evaluate the capabilities in recognizing the receptor-binding domain of SARS-CoV-2, spotting spike proteins of three respiratory syndromic coronaviruses, and blocking SARS-CoV-2 from binding to angiotensin-converting enzyme 2 receptors in vitro, respectively.

RESULTS

29 patients with KD before 2019, 74 patients with KD in 2019 or 2020, 54 non-febrile controls, and 24 febrile controls were included in the study. SARS-CoV-2 was recognized on ELISA for both patients with KD in 2016 and those with KD in 2020. Microwestern demonstrated cross-reactive IgG in an all-or-none manner towards three spike proteins of syndromic coronaviruses regardless of sample year or KD status. The ratio between the sera that recognized all spike proteins and those that recognized none (51 vs. 47) was significantly higher from patients with KD than from non-febrile controls (17 vs. 32; p 0.047) but not from febrile controls (13 vs. 11; p 0.85). Most positive sera (12 of 17 controls, 5 of 8 patients with KD before 2019, and 28 of 33 patients with KD in 2019 or 2020) offered protection comparable to low-titre sera from the WHO reference panel.

DISCUSSION

Humoral immunity of SARS-CoV-2-naïve children with KD was not inferior to that of controls in offering cross-protection against the novel coronavirus.

Augmented detection of septal defects using advanced optical coherence tomography network-processed phonocardiogram

BACKGROUND

Cardiac auscultation is a traditional method that is most frequently used for identifying congenital heart disease (CHD). Failure to diagnose CHD may occur in patients with faint murmurs or obesity. We aimed to develop an intelligent diagnostic method of detecting heart murmurs in patients with ventricular septal defects (VSDs) and atrial septal defects (ASDs).

MATERIALS AND METHODS

Digital recordings of heart sounds and phonocardiograms of 184 participants were obtained. All participants underwent echocardiography by pediatric cardiologists to determine the type of CHD. The phonocardiogram data were classified as normal, ASD, or VSD. Then, the phonocardiogram signal was used to extract features to construct diagnostic models for disease classification using an advanced optical coherence tomography network (AOCT-NET). Cardiologists were asked to distinguish normal heart sounds from ASD/VSD murmurs after listening to the electronic sound recordings. Comparisons of the cardiologists' assessment and AOCT-NET performance were performed.

RESULTS

Echocardiography results revealed 88 healthy participants, 50 with ASDs, and 46 with VSDs. The AOCT-NET had no advantage in detecting VSD compared with cardiologist assessment. However, AOCT-NET performance was better than that of cardiologists in detecting ASD (sensitivity, 76.4 vs. 27.8%, respectively; specificity, 90 vs. 98.5%, respectively).

CONCLUSION

The proposed method has the potential to improve the ASD detection rate and could be an important screening tool for patients without symptoms.

Epicardial Adipose Tissue Was Highly Associated with Reduction in Left Ventricular Diastolic Function as Early as in Adolescence

BACKGROUND

Epicardial adipose tissue (EAT) is increased in adolescents with obesity and may play a role in early cardiovascular pathophysiological changes. There is a lack of evidence focusing on the association between EAT and cardiac function in adolescents. This study explored associations between EAT, left ventricle (LV) geometric, and LV functional changes in adolescents.

METHODS

Adolescent volunteers between 10 and 20 years of age were included. Body mass index (BMI) was presented as age- and sex-specific BMI z-scores. Blood samples for glucose metabolism, lipid profiles, and high-sensitivity C-reactive protein (hs-CRP) were obtained. EAT thickness, LV hypertrophy, and LV diastolic function were measured by echocardiography.

RESULTS

The mean age of the 276 adolescents was 13.51 ± 2.44 years. BMI z-score was strongly associated with EAT thickness (r = 0.77; p < 0.001). Multivariable analysis revealed that age, insulin resistance, total cholesterol to high-density lipoprotein cholesterol ratio, and hs-CRP were independent predictors of increased EAT thickness. After adjusting for sex, age, and BMI z-score by multivariable analysis, EAT thickness was a strong predictor of higher LV mass indexed to height^2.7, higher relative wall thickness, lower mitral annulus e'/a', and higher E/e' of the mitral annulus. There was no association between EAT and LV ejection fraction.

CONCLUSIONS

EAT was highly associated with LV hypertrophy and reduction in LV diastolic function, independent of BMI z-score in the enrolled adolescents. Of note, the negative impacts of EAT on LV geometry and diastolic function occurred as early as in adolescence. This highlights the importance of preventing obesity and EAT deposition early in life.

A Metabolic Plasticity-Based Signature for Molecular Classification and Prognosis of Lower-Grade Glioma

Background: Glioma is one of the major health problems worldwide. Biomarkers for predicting the prognosis of Glioma are still needed. Methods: The transcriptome data and clinic information on Glioma were obtained from the CGGA, TCGA, GDC, and GEO databases. The immune infiltration status in the clusters was compared. The genes with differential expression were identified, and a prognostic model was developed. Several assays were used to detect RPH3A’s role in Glioma cells, including CCK-8, colony formation, wound healing, and transwell migration assay. Results: Lower Grade Glioma (LGG) was divided into two clusters. The immune infiltration difference was observed between the two clusters. We screened for genes that differed between the two groups. WGCNA was used to construct a co-expressed network using the DEGs, and four co-expressed modules were identified, which are blue, green, grey, and yellow modules. High-risk patients have a lower overall survival rate than low-risk patients. In addition, the risk score is associated with histological subtypes. Finally, the role of RPH3A was detected. The overexpression of RPH3A in LGG cells can significantly inhibit cell proliferation and migration and regulate EMT-regulated proteins. Conclusion: Our study developed a metabolic-related model for the prognosis of Glioma cells. RPH3A is a potential therapeutic target for Glioma.

Exercise Capacity and Ventricular Remodeling After Transcatheter Ventricular Septal Defect Closure in Asymptomatic or Minimally Symptomatic Adolescents and Adults

BACKGROUND

Transcatheter ventricular septal defect (VSD) closure is a safe and efficacious alternative to surgery. However, its benefits in asymptomatic or minimally symptomatic patients remain unknown.

METHODS

Sixty patients with VSD aged 12 to 60 years underwent cardiopulmonary exercise test and echocardiography 1 day before transcatheter VSD closure and 6 months after intervention (closure group). Thirty patients who did not receive the intervention underwent the same evaluations over 6 months (observation group).

RESULTS

No significant change in exercise function was observed after VSD closure, except for increased peak oxygen (O₂) pulse (absolute increase: 0.4±1.4 mL/beat). Left ventricular end-diastolic dimension and mitral peak early filling velocity-to-early diastolic annular velocity ratio decreased (absolute decrease: 0.3±0.6 cm and 0.7±1.9, respectively). Despite unchanged overall peak O₂ consumption, 33% of closure group patients exhibited clinically significant improvements in peak O₂ consumption (>10% increase relative to baseline). This was not related to the pulmonary flow-to-systemic flow ratio or baseline exercise capacity. By contrast, all exercise function parameters deteriorated significantly in the observation group. Subgroup analysis revealed that patients with a baseline left ventricular end-diastolic dimension Z score of >2 exhibited a significantly greater improvement in peak O₂ consumption, peak O₂ pulse, and oxygen uptake efficiency slope than did the observation group.

CONCLUSIONS

Compared with conservative management, transcatheter VSD closure prevents deterioration in exercise capacity and promotes left ventricular reverse remodeling in asymptomatic or minimally symptomatic patients. These benefits are most prominent in patients whose left ventricular end-diastolic dimension Z score before intervention is >2, irrespective of baseline peak O₂ consumption and pulmonary flow/systemic flow ratio. Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03127748.

Initial Experience With Patent Ductus Arteriosus Ligation in Pre-term Infants With Bidirectional Shunt Pattern

Background: Patent ductus arteriosus (PDA) with a bidirectional shunt reflects critical clinical conditions. The operability of PDA with a bidirectional shunt in pre-term infants is still not clearly clarified. This study aimed to investigate the feasibility and the outcomes of PDA ligation in pre-term infants with a bidirectional shunt PDA. Methods: All pre-term infants receiving PDA ligation between 2013 and 2019 were enrolled in this prospective study. Patients were allocated into two groups based on the shunting direction of PDA, which were the left-to-right group (group A) and the bidirectional group (group B). Clinical characteristics and pre-op comorbidities were analyzed. Intraoperative complications, post-op neurological sequelae, necrotizing enterocolitis, survival, and mortality were compared between these two groups. Results: Thirty-seven pre-term infants were enrolled (18 in group A, 19 in group B). The mean post-menstrual age at PDA surgery was 32.0 ± 1.3 and 32.8 ± 1.5 weeks, respectively. Before surgery, 44.4 and 89.5% (group A vs. B) of the patients were using invasive mechanical ventilator (p < 0.01). The requirement of high-frequency oscillatory ventilatory support was significantly higher in group B. PDA rupture-related bleeding during exposing PDA or ligating PDA occurred in four infants, and all were all in group B, including one with delayed hemothorax. Early surgical mortality within 30 days of surgery was higher in group B (0 vs. 21.1%, p < 0.05), but only one death could be attributed to the surgery, which was caused by a pain-induced pulmonary hypertension crisis. The 5-year survival was 100% in group A, and 73.7% in group B (p < 0.05). Conclusion: We did not recommend routine PDA ligation in pre-term infants with a bidirectional shunt. However, a bidirectional shunt should not be an absolute contraindication if they fulfill indications of PDA closure. Unexpected intraoperative PDA rupture and delayed hemothorax in a bidirectional shunt PDA should be carefully monitored. Aggressive post-op pain control is also warranted to avoid pulmonary hypertension crisis. The post-op early mortality rate was higher in the bidirectional group, which could be inherent to their poor pre-operative lung condition. Only one death was directly related to the surgery.

Serum apoptotic marker M30 is positively correlated with early diastolic dysfunction in adolescent obesity

Purpose

Obesity in adolescence has been shown to be related to cardiac geometric and functional changes. Cardiac dysfunction in adults with obesity could be attributed to chronic low-grade inflammation, apoptosis of cardiomyocyte, and glucose metabolic disorder. The aforementioned association in adolescents with obesity have never been well studied. Our aim was to determine the types of cardiac dysfunction in adolescents with obesity and survey the association between cardiac dysfunction and chronic low-grade inflammation, apoptosis, and glucose dysregulation in adolescents with obesity.

Methods

Adolescents aged between 10 and 20 years were enrolled in this study. Body mass index, waist-to-hip ratio, blood pressure, glucose metabolism, and high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-a (TNF-α), and apoptosis marker M30 levels were measured. Echocardiographic indices were also measured. The association between serum biomarkers and echocardiographic function parameters was analyzed.

Results

Diastolic dysfunction was the major finding in the cardiac functional assessment. The main changes in glucose metabolism were elevated C-peptide level and insulin resistance. Hs-CRP, IL-6, and M30 levels also increased with adolescent obesity. M30 was the major biomarker that was highly correlated to diastolic dysfunction indices in adolescents with obesity.

Conclusions

Diastolic dysfunction was the main change in adolescent obesity. Insulin resistance, apoptotic marker M30, hs-CRP, and IL-6 were all elevated in adolescents with obesity. Only M30 was related to indices of left ventricular diastolic dysfunction among adolescents with obesity, rather than inflammation or insulin resistance.

High correlation between human rhinovirus type C and children with asthma exacerbations in Taiwan

BACKGROUND/PURPOSES

Human rhinovirus type C (HRV-C) has been associated with asthma exacerbation (AE) in children in several countries. However, in Taiwan the association between HRV, especially HRV-C, and AE in children has yet to be elucidated. We sought to investigate the prevalence of respiratory viruses in children with acute lower respiratory tract infection (ALRTI) in Taiwan and the association between different types of HRV and AE in children.

METHODS

This prospective study was conducted from 2011 to 2013, and enrolled children with ALRTI, including an asthma exacerbation group (AE; n = 28) and a Non-asthma group (n = 66). Viruses were detected by culture, reverse transcription-polymerase chain reaction, and molecular sequencing of nasopharyngeal swabs.

RESULTS

The prevalence of identified respiratory viruses was 78.6% in the AE group and 65.2% in the Non-asthma group. The prevalence rates of HRV and HRV-C were significantly higher in the AE group than in the Non-asthma group (67.9% vs. 33.3% in HRV, p = 0.002; and 50% vs. 15.2% in HRV-C, p < 0.001). Among the children with HRV, the prevalence of HRV-C (68.4%) was higher than that of the other types of HRV (31.6%, including HRV-A 26.3%, and HRV-B 5.3%) in the AE group but not in the Non-asthma group (40.9% vs. 59.1%).

CONCLUSIONS

HRV is the most predominant viral infection responsible for pediatric AE in Taiwan, and HRV-C is responsible for more of these exacerbations than HRV-A or HRV-B.

P68 RNA helicase promotes invasion of glioma cells through negatively regulating DUSP5

Gliomas are the most common central nervous system tumors. They show malignant characteristics indicating rapid proliferation and a high invasive capacity and are associated with a poor prognosis. In our previous study, p68 was overexpressed in glioma cells and correlated with both the degree of glioma differentiation and poor overall survival. Downregulating p68 significantly suppressed proliferation in glioma cells. Moreover, we found that the p68 gene promoted glioma cell growth by activating the nuclear factor‐κB signaling pathway by a downstream molecular mechanism that remains incompletely understood. In this study, we found that dual specificity phosphatase 5 (DUSP5) is a downstream target of p68, using microarray analysis, and that p68 negatively regulates DUSP5. Upregulating DUSP5 in stably expressing cell lines (U87 and LN‐229) suppressed proliferation, invasion, and migration in glioma cells in vitro, consistent with the downregulation of p68. Furthermore, upregulating DUSP5 inhibited ERK phosphorylation, whereas downregulating DUSP5 rescued the level of ERK phosphorylation, indicating that DUSP5 might negatively regulate ERK signaling. Additionally, we show that DUSP5 levels were lower in high‐grade glioma than in low‐grade glioma. These results suggest that the p68‐induced negative regulation of DUSP5 promoted invasion by glioma cells and mediated the activation of the ERK signaling pathway.

Recent review of transcatheter closure of atrial septal defect

Atrial septal defect (ASD) is one of the two most common congenital heart diseases in children and adult. After the application of catheter intervention for ASD, this became an alternative treatment other than surgery from late 1990. In 2001, the procedure was further approved by the US Food and Drug Administration (FDA), and become the first choice for most cases of secundum type of ASD worldwide. The success rate is more than 98% in literature reviews, with low complication rates in percutaneous ASD closure. Major complications are around 1%, including device embolization, cardiac erosions, new-onset atrial arrhythmia, and other comorbidities. We reviewed indications for percutaneous secundum type ASD closure, technique, successful rate and major complications in this article. To complete the catheter intervention with difficult ASD conditions, various procedural techniques have been developed recently. We also report a challenging case by a current balloon-assisted technique for huge ASD closure.

Neonatal gastric perforation: a report of two cases and a systematic review

RATIONALE

Neonatal gastric perforation is a rare and life-threatening disorder in neonates and is associated with high morbidity and mortality. However, the exact mechanisms of neonatal gastric perforation remain unknown.

PATIENT CONCERNS

In this study, we reported 2 cases of neonatal gastric perforation and conducted a systematic review to analyze the prognostic factors for mortality.

DIAGNOSES

Two neonates received a diagnosis of gastric perforation based on clinical presentation and imaging studies. The 2 patients underwent emergent surgery, which yielded favorable outcomes.

INTERVENTIONS

We reviewed 168 cases from the literature as well as our 2 cases to analyze whether mortality in neonatal gastric perforation is associated with sex, gestational age, operation type, perforation location, or timing of perforation.

OUTCOMES

The results revealed that mortality was significantly higher in preterm neonates (n = 80, P < .01) and the mortality group had a lower birth weight (n = 73, P < .05). The timing of perforation in the preterm subgroup was significantly earlier than that in the full-term subgroup (n = 90, P < .05). The outcomes about mortality of gastric perforation were significantly associated with preterm neonates (adjusted odds ratio: 4.21, 95% confidence interval: 1.28-13.88, P < .05).

LESSONS

This study shows the prognostic factor of gastric perforation was significantly associated with preterm neonates. Furthermore, low-birth-weight full-term neonates had a relatively higher mortality rate than the normal-birth-weight full-term neonates. In addition, preterm neonates have an earlier timing of perforation.

Novel Ultrasonographic Fatty Liver Indicator Can Predict Hepatitis in Children With Non-alcoholic Fatty Liver Disease

Background: Childhood non-alcoholic fatty liver disease (NAFLD) is a public health issue worldwide. To date, liver biopsy remains the gold standard for diagnosing the severity of NAFLD. However, this invasive procedure might contribute to complications. Owing to this reason, a good non-invasive tool to estimate NAFLD in children is urgently needed. We sought to investigate whether a non-invasive semi-quantitative ultrasonographic fatty liver indicator (US-FLI) can estimate NAFLD in children. Methods: Children aged between 10 and 18 years were enrolled prospectively. Abdominal ultrasonography was performed by a single experienced pediatric gastroenterologist and the non-invasive semi-quantitative US-FLI score were used. Patients were diagnosed with NAFLD if they had a US-FLI score ≥2. The anthropometric measures, obesity-related biochemical results, and levels of tumor necrosis factor-α, interleukin-6, caspase-cleaved cytokeratin fragment of cytokeratin 18 (M30), and adiponectin were also checked. Results: Overall, 117 children aged 10-18 years were enrolled. The anthropometric measures and obesity-related biochemical parameters (hsCRP, triglyceride, uric acid, AST, ALT, γ-GT, homeostatic model assessment insulin resistance (HOMA-IR), and M30) were significantly higher in the obesity group than in the non-obesity group (p < 0.05). Similarly, the US-FLI score was significantly higher in the obesity group than that in the non-obesity group (p < 0.001). Multiple linear regression showed that the US-FLI score was significantly associated with the waist-to-height ratio, uric acid, adiponectin, and M30 levels (all p < 0.05) in children with obesity. The US-FLI score ≥6 was the optimal cut-off point for predicting the hepatitis in children with NAFLD. The area under the receiver operating characteristic curve was 0.710 (95% CI: 0.572-0.847; p = 0.005). Conclusions: The non-invasive US-FLI score can predict hepatitis in children with NAFLD without mandatory liver biopsy. Moreover, the waist-to-height ratio, uric acid, adiponectin, and M30 levels were significantly associated with US-FLI score in children with obesity.

Pediatric types I and VI choledochal cysts complicated with acute pancreatitis and spontaneous perforation: A case report and literature review

RATIONALE

Choledochal cysts are a congenital disorder of the common bile duct that can cause progressive biliary obstruction and biliary cirrhosis. They were classified by Todani into five types. Of these, type VI choledochal cysts are rarely reported in the literature.

PATIENT CONCERNS

A 22-month-old girl presented with intermittent epigastralgia for approximately 10 days and fever for three days. Fasting and total parenteral nutrition were administered after admission. However, sudden onset of severe epigastric pain occurred. An abdominal sonogram showed turbid ascites and peritonitis was impressed.

DIAGNOSES

An emergent exploratory laparotomy was performed, and perforation of the posterior wall of types I and VI choledochal cysts was observed.

INTERVENTIONS

Intraoperative cholangiography revealed concomitant types I and VI choledochal cysts with stricture of the distal common bile duct. Definite surgery for resection of the choledochal cysts and gallbladder was performed with Roux-en-Y choledochojejunostomy.

OUTCOMES

The patient had no evidence of ascending cholangitis at three years after the operation.

LESSONS

Type VI choledochal cysts are rarely reported in the literature. To our knowledge, this is the first reported pediatric case of concomitant types I and VI choledochal cysts complicated with acute pancreatitis and spontaneous perforation.

Assessing utility of exercise test in determining exercise prescription in adolescent and adult patients with repaired tetralogy of fallot

Parameters from cardiopulmonary exercise test (CPET) are useful prognostic factors for patients with repaired tetralogy of fallot (TOF). Its application in exercise prescription remains unclear. This study sought to define its role. We made current exercise recommendations in repaired TOF patients according to European Society of Cardiology (ESC) guideline, which were based on ventricular function, pressure/volume load, pulmonary artery pressure, hypoxemia and arrhythmic burden both at rest and during exercise. CPET parameters (peak oxygen consumption, oxygen uptake efficiency plateau, and E/CO₂ slope), along with cardiothoracic ratio, ventricular arrhythmia, QRS duration and NYHA functional status, were used to calculate "score to exercise". 112 repaired TOF adolescent and adult aged 32.6 ± 10.8 (14.05- to 56.99-year-old, median 30.1) years received exercise recommendations by ESC guideline, which suggested high, moderate and low intensity sports for 45 (40.2 %), 45 (40.2 %), and 22 (19.6 %) patients, respectively. The optimal cut-off values were 67 and 77 % for peak VO₂, 86 and 100 % for OUEP, 22 and 28 for E/CO₂ slope to correlate to the exercise intensity recommendation. But, individual CPET parameter had low consistency (41-46 %) in making decisions of exercise intensity compared to ESC recommendations. Using the "score to exercise", the consistency rate could be increased to 74.1 %. With "score to exercise" recommended exercise intensity, follow-up result revealed no adverse event related to sports. Individual CPET parameter did not correlate well to the exercise recommendation from ESC. We proposed a scoring system, "score to exercise", which incorporates three CPET parameters with cardiothoracic ratio, ventricular arrhythmia, QRS duration and NYHA functional status. Score to exercise is easy to be assessed and provides useful information for exercise recommendation in patients with repaired TOF.

Assessing Late Cardiopulmonary Function in Patients with Repaired Tetralogy of Fallot Using Exercise Cardiopulmonary Function Test and Cardiac Magnetic Resonance

BACKGROUND

Patients with repaired tetralogy of Fallot (TOF) usually experience progressive right ventricle (RV) dysfunction due to pulmonary regurgitation (PR). This could further worsen the cardiopulmonary function. This study aimed to compare the changes in patient exercise cardiopulmonary test and cardiac magnetic resonance imaging, and consider the implication of these changes.

METHODS

Our study examined repaired TOF patients who underwent cardiopulmonary exercise test (CPET) to obtain maximal (peak oxygen consumption, peak VO2) and submaximal parameters (oxygen uptake efficiency plateau, oxygen uptake efficiency plateau (OUEP), and ratio of minute ventilation to carbon dioxide production, VE/VCO2 slope). Additionally, the hemodynamic status was assessed by using cardiac magnetic resonance. Criteria for exclusion included TOF patients with pulmonary atresia, atrioventricular septal defect, or absence of pulmonary valve syndrome.

RESULTS

We enrolled 158 patients whose mean age at repair was 7.8 ± 9.1 years (range 0.1-49.2 years) and the mean patient age at CPET was 29.5 ± 12.2 years (range 7.0-57.0 years). Severe PR (PR fraction ≥ 40%) in 53 patients, moderate in 55, and mild (PR fraction < 20%) in 50 patients were noted. The mean RV end-diastolic volume index (RVEDVi) was 113 ± 35 ml/m(2), with 7 patients observed to have a RVEDVi > 163 ml/m(2). The mean left ventricular ejection fraction (LVEF) was 63 ± 8%, left ventricular end-diastolic volume index (LVEDVi) was 65 ± 12 ml/m(2), and LVESVi was 25 ± 14 ml/m(2). CPET revealed significantly decreased peak VO2 (68.5 ± 14.4% of predicted), and fair OUEP (90.3 ± 14.1% of predicted) and VE/VCO2 slope (27.1 ± 5.3). PR fraction and age at repair were negatively correlated with maximal and submaximal exercise indicators (peak VO2 and OUEP). Left ventricular (LV) function and size were positively correlated with peak VO2 and OUEP.

CONCLUSIONS

The results of CPET showed that patients with repaired TOF had a low maximal exercise capacity (peak VO2), but a fair submaximal exercise capacity (OUEP and VE/VCO2 slope), suggesting limited exercise capability in high intensity circumstances. PR, LV function and age at total repair were the most important determinants of CPET performance.

KEY WORDS

Cardiac magnetic resonance; Cardiopulmonary exercise function; Pulmonary regurgitation; Surgical age; Tetralogy of Fallot.

Ventricular geometric characteristics and functional benefit of mild right ventricular outflow tract obstruction in patients with significant pulmonary regurgitation after repair of tetralogy of Fallot

BACKGROUND

Right ventricular (RV) outflow tract obstruction (RVOTO) might protect the RV from adverse remodeling caused by significant pulmonary regurgitation (PR) in patients with repaired tetralogy of Fallot (rTOF), but the underlying mechanisms and influences on exercise tolerance remain unclear. This study sought to investigate the impacts from mild RVOTO on ventricular remodeling and exercise capacity in rTOF.

METHODS

Eighty-five rTOF patients with a PR fraction ≥20% were assessed with cardiac magnetic resonance, cardiopulmonary exercise test, and echocardiography. Patients with a peak RVOT pressure gradient 20-50 mmHg were considered to have mild RVOTO (n = 29), while those with a gradient <20 mmHg had isolated PR (n = 56).

RESULTS

Comparing to patients with isolated PR, patients with combined PR and mild RVOTO had smaller RV and RVOT dimension, better RV and left ventricular (LV) ejection fraction (EF), and superior exercise capacity. PR severity and RV mass/volume ratio were similar between these 2 groups. LVEF coupled with RVEF only in patients with isolated PR. In multivariate analysis, smaller RVOT dimension was independently related to smaller RV dimension (P < .001) and higher RVEF (P = .005). Furthermore, mild RVOTO was independently associated with higher peak oxygen consumption (P = .014) and oxygen uptake efficiency slope (P = .005).

CONCLUSIONS

Patients with combined PR and mild RVOTO had better RV remodeling and exercise capacity compared to those with isolated PR. Our findings confirm the benefits from mild residual RVOTO support a policy of conservative RVOTO relief at repair.

Increased expression of ABCB6 enhances protoporphyrin IX accumulation and photodynamic effect in human glioma

BACKGROUND

Glioma recurrence usually occurs close to the tumor resection margins as a result of residual infiltrating glioma cells. 5-aminolevulinic acid (ALA) fluorescence-guided resection of gliomas has been demonstrated to enhance discrimination of tumor tissue and to improve survival. ALA-based photodynamic therapy is an effective albeit still experimental adjuvant treatment option for gliomas. However, insufficient protoporphyrin IX (PpIX) accumulation may limit the benefits of fluorescence-guided resection and photodynamic therapy.

METHODS

We investigated the expression of the ATP-binding cassette transporter ABCB6, which regulates porphyrin synthesis, in surgical specimens from human gliomas and manipulated ABCB6 in human glioma cell lines.

RESULTS

Our findings demonstrated that expression levels of ABCB6 were greatly elevated in human gliomas compared with normal brain tissues and correlated with World Health Organization histologic grade. A previously undescribed finding was that ABCB6 mRNA expression in solidly fluorescing tumor tissues was higher than that in vaguely fluorescing tumors, suggesting that ABCB6 may be at least in part responsible for PpIX accumulation in glioma cells. Accordingly, ABCB6 overexpression in glioma cell lines caused a marked increase in intracellular levels of PpIX, and was more sensitive to ALA-induced photodynamic therapy-events that could be prevented by silencing ABCB6 via siRNA treatment.

CONCLUSIONS

Our findings indicate a crucial role of ABCB6 in ALA metabolism and accumulation of PpIX in glioma. ABCB6 overexpression is a potential approach to enhance accumulation of PpIX for optimizing the subjective discrimination of vague fluorescence and improving the efficacy of ALA-based photodynamic therapy.

Implication of early-onset biliary atresia and extrahepatic congenital anomalies

BACKGROUND

The aim of the present study was to determine the rate of early-onset biliary atresia (BA) and its implications, for embryonic-type BA in Taiwan, a high-prevalence area for BA. The relationship between the timing of disease onset and congenital extrahepatic anomalies was also identified.

METHODS

Medical records of 130 infants born in Taiwan with biliary atresia between January 1996 and December 2005 were reviewed retrospectively. The gold standard for the diagnosis of biliary atresia was intraoperative cholangiography. As well as medical records review, abdominal imaging and echocardiograms were performed to determine other structural anomalies. Early-onset BA was defined as acholic stool and cholestatic jaundice observed before 2 weeks of age.

RESULTS

On review of onset of acholic stool and cholestatic jaundice before 2 weeks of age, 31 patients (23.8%) were defined as having early-onset BA. Twenty patients (15.4%) had major congenital extrahepatic anomalies. One (0.7%) had biliary atresia splenic malformation syndrome (BASM). Both early-onset and late-onset BA may be associated with other structural anomalies. Patients with early-onset BA had a higher probability of having major extrahepatic anomaly (9/31 vs 11/99, P = 0.046). Situs anomalies accompanying major gastrointestinal (GI) tract anomalies occurred only in early-onset BA patients.

CONCLUSIONS

After comprehensively investigating the timing of onset and associated congenital extrahepatic anomalies in BA patients in Taiwan, only one BASM with double spleen was detected. A total of 23.8% of patients had early-onset BA, and this group of patients is prone to extrahepatic anomalies. Situs anomalies accompanying major GI tract anomaly may be indicative of embryonic-type early-onset BA.

Phase contribution of image potential on empty quantum well States in pb islands on the cu(111) surface

We use scanning tunneling spectroscopy to explore the quantum well states in the Pb islands grown on a Cu(111) surface. Our observation demonstrates that the empty quantum well states, whose energy levels lie beyond 1.2 eV above the Fermi level, are significantly affected by the image potential. As the quantum number increases, the energy separation between adjacent states is shrinking rather than widening, contrary to the prediction for a square potential well. By simply introducing a phase factor to reckon the effect of the image potential, the shrinking behavior of the energy separation can be reasonably explained with the phase accumulation model. The model also reveals that there exists a quantum regime above the Pb surface in which the image potential is vanished. Moreover, the quasi-image-potential state in the tunneling gap is quenched because of the existence of the quantum well states.

Factors influencing the successful treatment of infectious pulmonary tuberculosis

SETTING

Achieving successful treatment of infectious pulmonary tuberculosis (PTB) could reduce the spread of tuberculosis (TB) and the emergence of multidrug resistance.

OBJECTIVE

To explore factors associated with successful treatment for sputum-positive PTB.

DESIGN

This study used a population-based retrospective cohort design. All PTB patients residing in southern Taiwan recorded in the tuberculosis registry from 1 January to 30 June 2003 were identified. Each patient's medical record was requested from treating hospitals and retrospectively reviewed for 15 months after the date PTB was confirmed.

RESULTS

There were 399 PTB patients included in the study. Factors significantly associated with successful treatment included treatment by pulmonologists (OR 1.93), receiving directly observed therapy (DOT) (OR 1.76) and receiving treatment at the chest hospital (OR 5.41). Patients of advanced age were less likely to achieve treatment success (OR 0.97). Among patients treated by pulmonologists, those treated at the chest hospital had a significantly higher treatment success rate than those treated at other institutions (94.1% vs. 69.9%).

CONCLUSIONS

Patients treated with DOT and by pulmonologists, especially at the chest hospital, had a higher treatment success rate. DOT and training of care professionals and institutions are therefore important factors that affect the successful treatment of TB.

A Novel Conformation-Dependent Monoclonal Antibody Specific to the Native Structure of β-Lactoglobulin and Its Application

Molten globules are thought to be general intermediates in protein folding and unfolding. beta-lactoglobulin (beta-LG) is one of the major bovine whey proteins, constituting approximately 10 to 15% of total milk proteins. We have recently identified beta-LG as a superior marker for evaluating thermally processed milk. Strand D of beta-LG participates in irreversible thermal unfolding as probed by a monoclonal antibody (mAb) specific to thermally denatured beta-LG. In the present study, we used native beta-LG as an immunogen to test the hypothesis that a specific mAb against the native beta-LG could be established. As result, a mAb (4H11E8) directed against the native structure of beta-LG was made. The antibody did not recognize the heat-denatured form of beta-LG, such as its dimer and aggregates. Immunoassay using this "native" mAb showed that the stability of beta-LG was at temperatures < or =70 degrees C. beta-Lactoglobulin began to deteriorate between 70 and 80 degrees C over time. The denaturation was correlated with the transition temperature of beta-LG. Further chemical modification of Cys (carboxymethylation) or positively charged residues (acetylation) of beta-LG totally abolished its immunoreactivity, confirming the conformation-dependent nature of this mAb. Using competitive ELISA, the 4H11E8 mAb could determine the native beta-LG content in commercially processed milks. Concentrations of native beta-LG varied significantly among the local brands tested. From a technological standpoint, the mAb prepared in this study is relevant to the design and operation of appropriate processes for thermal sanitation of milk and of other dairy products.

Smoking attributable medical expenditures, years of potential life lost, and the cost of premature death in Taiwan

OBJECTIVE

To estimate the smoking attributable medical expenditures and productivity loss of people aged 35 and over in Taiwan in 2001 from a societal viewpoint.

METHODS

A prevalence based approach was used to estimate smoking attributable costs. Epidemiological parameters were obtained from two follow up studies and government statistics. Data on medical care utilisation and expenditure were extracted from the National Health Insurance claim data.

RESULTS

Total smoking attributable medical expenditures (SAEs) amounted to USD 397.6 million, which accounted for 6.8% of the total medical expenditures for people aged 35 and over. Mean annual medical expenditures per smoker was USD 70 more than that of each non-smoker. Smoking attributable years of potential life lost (YPLL) totalled to 217,761 years for males and 15,462 years for females, and the corresponding productivity loss was USD 1371 million for males and USD 18.7 million for females.

CONCLUSION

Medical expenditures attributable to smoking accounted for 6.8% of the total medical expenditure of people aged 35 and over for the year 2001 in Taiwan. Corresponding YPLL and productivity loss also demand that actions be taken to fight cigarette smoking.

Acute mediastinitis resulting from an unsuspected fish bone--case report

Acute mediastinitis is a serious medical condition with a mortality rate from 30 to 40% or even higher. Early diagnosis with prompt and aggressive treatment is essential to prevent its rapid progression. Severe odynophagia and respiratory distress with positive neck or chest findings should raise suspicion of mediastinitis. We report a rare case of acute mediastinitis secondary to the unexpected migration of an impacted fish bone from the esophagus.

The use of air fuel cell cathodes to remove contaminants from spent chromium plating solutions

Results from experiments using an impregnation-reduction (I-R) Pt / Nafion membrane electrode assembly (MEA) in an air fuel cell cathode to remove contaminants (Cu(II), Ni(II), and Fe(III)) from spent chromium electroplating baths are presented in this study. A platinum-carbon (Pt-C) / Nafion MEA and a Pb planar cathode were also used for comparison. The average removal rates of Cu(II) and Ni(II) were almost the same (0.39 and 0.40 mM hr(-1) (or 0.117 and 0.12 mmol hr(-1)), respectively) but higher than that of Fe(III) (0.16 mM hr(-1), or 0.048 mmol hr(-1)) in accordance with the Nernst-Planck flux equation. The removal rates for the same cation were independent of the cathode used. The average removal rate of each impurity was approximately proportional to the product of its initial concentration and separator area/anolyte volume ratio using Pb cathodes. Under constant current conditions the system using the Pt-C / Nafion cathode needed the highest cell voltage, about 3 V more than needed for the system with the Pt / Nafion cathode. The cell voltage required using the Pt / Nafion cathode was similar to that using the conventional planar Pb cathode. Analyses of cathode deposits by SEM/EDS and XPS techniques indicated they were minimal on the Pb and Pt / Nafion cathode and more apparent on the Pt-C / Nafion cathode. The primary deposits on the Pb cathode were chromium oxides (e.g., Cr2O3) with minor amount of lead chromate (lead dichromate or lead trichromate) and other chromium solids (Cr black). As expected, the dominant deposit on the lead anode surface was PbO2.

Protein adsorption, fibroblast activity and antibacterial properties of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) grafted with chitosan and chitooligosaccharide after immobilized with hyaluronic acid

Poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) membrane was treated with ozone and grafted with acrylic acid. The resulting membranes were further grafted with chitosan (CS) or chitooligosaccharide (COS) via esterification. Afterward hyaluronic acid (HA) was immobilized onto CS- or COS-grafting membranes. The antibacterial activity of CS and COS against Staphylococus aureus, Escherichia coli, and Pseudomonas aeruginosa was preserved after HA immobilization. Among them, CS-grafted PHBV membrane showed higher antibacterial activity than COS-grafted PHBV membrane. In addition, after CS- or COS-grafting, the L929 fibroblasts attachment and protein adsorption were improved, while the cell number was decrease. After immobilizing HA, the cell proliferation was promoted, the protein adsorption was decreased, and the cell attachment was slightly lower than CS- or COS-grafting PHBV.

Cell membrane transport of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the liver and systemic bioavailability

Modulation of hepatic disposition of MPTP could influence susceptibility to its neurotoxicity. Therefore, we studied hepatocellular transport of MPTP in the perfused rat liver and isolated rat hepatocytes. The perfused liver extensively extracted MPTP. Amiloride and tubocurarine, inhibitors of OCT1, increased MPTP recovery (253 +/- 78 and 283 +/- 64%, respectively) and reduced PS(influx) (0.69 +/- 0.36 to 0.27 +/- 0.11, and 0.97 +/- 0.50 to 0.23 +/- 0.05 ml/s/g, respectively). P-glycoprotein inhibitor, daunomycin, and Oatp 1 & 2 inhibitor, rifamycin, had no effect. In isolated hepatocytes, amiloride and tubocurarine increased hepatic uptake of MPTP (23 +/- 12 and 6 +/- 2%, respectively). Daunomycin reduced MPTP uptake by 22 +/- 8% and rifamycin had no effect. Only a small proportion of MPTP is taken up into hepatocytes by transporters; however, modulation of these transport mechanisms will influence systemic bioavailability.

A multivalent pairing model of linkage analysis in autotetraploids

Polyploidy has been recognized as an important step in the evolutionary diversification of flowering plants and may have a significant impact on plant breeding. Statistical analyses for linkage mapping in polyploid species can be difficult due to considerable complexities in polysomic inheritance. In this article, we develop a novel statistical method for linkage analysis of polymorphic markers in a full-sib family of autotetraploids. This method is established on multivalent pairings of homologous chromosomes at meiosis and can provide a simultaneous maximum-likelihood estimation of the double reduction frequencies of and recombination fraction between two markers. The EM algorithm is implemented to provide a tractable way for estimating relative proportions of different modes of gamete formation that generate identical gamete genotypes due to multivalent pairings. Extensive simulation studies were performed to demonstrate the statistical properties of this method. The implications of the new method for understanding the genome structure and organization of polyploid species are discussed.

A statistical method for flagging weak spots improves normalization and ratio estimates in microarrays

Over the last few years, there has been a dramatic increase in the use of cDNA microarrays to monitor gene expression changes in biological systems. Data from these experiments are usually transformed into expression ratios between experimental samples and a common reference sample for subsequent data analysis. The accuracy of this critical transformation depends on two major parameters: the signal intensities and the normalization of the experiment vs. reference signal intensities. Here we describe and validate a new model for microarray signal intensity that has one multiplicative variation and one additive background variation. Using replicative experiments and simulated data, we found that the signal intensity is the most critical parameter that influences the performance of normalization, accuracy of ratio estimates, reproducibility, specificity, and sensitivity of microarray experiments. Therefore, we developed a statistical procedure to flag spots with weak signal intensity based on the standard deviation (delta(ij)) of background differences between a spot and the neighboring spots, i.e., a spot is considered as too weak if the signal is weaker than cdelta(ij). Our studies suggest that normalization and ratio estimates were unacceptable when this threshold (c) is small. We further showed that when a reasonable compromise of c (c = 6) is applied, normalization using trimmed mean of log ratios performed slightly better than global intensity and mean of ratios. These studies suggest that decreasing the background noise is critical to improve the quality of microarray experiments.

Cytological evidence for association of the ends of the linear chromosome in Streptomyces coelicolor

The chromosome of the filamentous bacterium Streptomyces coelicolor is linear, but the genetic map is circular. We present cytological evidence based on the use of fluorescence in situ hybridization showing that the ends of the chromosome frequently colocalize, in agreement with the idea that the ends are held together, effectively forming a circular chromosome. These observations provide a possible explanation for how a linear bacterial chromosome can exhibit a circular genetic map.

Clinical wear performance of eight experimental dental composites over three years determined by two measuring methods

The effect of matrix selection, filler composition, filler silanization, operator variations, and test site (dental clinic) on the wear rate of eight composites were evaluated. The wear was measured on replicas using both a microscopic and a laser scanning measuring method. The average wear rate on contact-free surfaces was 9.2 +/- 4.2 microm/month with the microscopic measurement and 8.5 +/- 3.7 microm/ month with the laser scanner over the 36-month period. The urethane-based composites performed significantly better than those which were bisGMA-based. Restorations placed at one dental clinic showed significantly lower initial wear. There was also a significant difference between the operators that was most pronounced during the first 6 months. The other variable (filler composition and silane treatment) did not affect the wear rate significantly.

Forkhead homologue in rhabdomyosarcoma functions as a bifunctional nuclear receptor-interacting protein with both coactivator and corepressor functions

In a search for novel transcriptional intermediary factors for the estrogen receptor (ER), we used the ligand-binding domain and hinge region of ER as bait in a yeast two-hybrid screen of a cDNA library derived from tamoxifen-resistant MCF-7 human breast tumors from an in vivo athymic nude mouse model. Here we report the isolation and characterization of the forkhead homologue in rhabdomyosarcoma (FKHR), a recently described member of the hepatocyte nuclear factor 3/forkhead homeotic gene family, as a nuclear hormone receptor (NR) intermediary protein. FKHR interacts with both steroid and nonsteroid NRs, although the effect of ligand on this interaction varies by receptor type. The interaction of FKHR with ER is enhanced by estrogen, whereas its interaction with thyroid hormone receptor and retinoic acid receptor is ligand-independent. In addition, FKHR differentially regulates the transactivation mediated by different NRs. Transient transfection of FKHR into mammalian cells dramatically represses transcription mediated by the ER, glucocorticoid receptor, and progesterone receptor. In contrast, FKHR stimulates rather than represses retinoic acid receptor- and thyroid hormone receptor-mediated transactivation. Most intriguingly, overexpression of FKHR dramatically inhibits the proliferation of ER-dependent MCF-7 breast cancer cells. Therefore, FKHR represents a bifunctional NR intermediary protein that can act as either a coactivator or corepressor, depending on the receptor type.

A localized GTPase exchange factor, Bud5, determines the orientation of division axes in yeast

GTPases are widespread in directing cytoskeletal rearrangements and affecting cellular organization. How they do so is not well understood. Yeast cells divide by budding, which occurs in two spatially programmed patterns, axial or bipolar [1-3]. Cytoskeletal polarization to form a bud is governed by the Ras-like GTPase, Bud1/Rsr1, in response to cortical landmarks. Bud1 is uniformly distributed on the plasma membrane, so presumably its regulators, Bud5 GTPase exchange factor and Bud2 GTPase activating protein, impart spatial specificity to Bud1 action [4]. We examined the localizations of Bud5 and Bud2. Both Bud1 regulators associate with cortical landmarks designating former division sites. In haploids, Bud5 forms double rings that encircle the mother-bud neck and split upon cytokinesis so that each progeny cell inherits Bud5 at the axial division remnant. Recruitment of Bud5 into these structures depends on known axial landmark components. In cells undergoing bipolar budding, Bud5 associates with multiple sites, in response to the bipolar landmarks. Like Bud5, Bud2 associates with the axial division remnant, but rather than being inherited, Bud2 transiently associates with the remnant in late G1, before condensing into a patch at the incipient bud site. The relative timing of Bud5 and Bud2 localizations suggests that both regulators contribute to the spatially specific control of Bud1 GTPase.