Cloning, chromosomal organization and expression analysis of Neurl, the mouse homolog of Drosophila melanogaster neuralized gene

The Drosophila neuralized (neur) gene belongs to the neurogenic group of genes involved in regulating cell-cell interactions required for neural precursor development. neur mutant phenotypes include strong overcommitment to neural fates at the expense of epidermal fates. The human neuralized homolog (NEURL) has been recently determined and found to map to chromosome 10q25.1 within the region frequently deleted in malignant astrocytomas. Because of its potential importance in developmental processes, we analyzed the structure of the mouse homolog, Neurl, and its expression pattern in embryonic tissues. Neurl activity is detected from early developmental stages in several tissues and organs including neural tissues, limbs, the skeletal system, sense organs and internal organs undergoing epithelial-mesenchymal interactions. Neurl encodes a polypeptide associated with the plasma membrane but also detected in the cytoplasm. Similarly to the Drosophila gene, mammalian neuralized may code for an important regulatory factor.     

14-3-3 proteins and survival kinases cooperate to inactivate BAD by BH3 domain phosphorylation

The Bcl-2 homology 3 (BH3) domain of prodeath Bcl-2 family members mediates their interaction with prosurvival Bcl-2 family members and promotes apoptosis. We report that survival factors trigger the phosphorylation of the proapoptotic Bcl-2 family member BAD at a site (Ser-155) within the BAD BH3 domain. When BAD is bound to prosurvival Bcl-2 family members, BAD Ser-155 phosphorylation requires the prior phosphorylation of Ser-136, which recruits 14-3-3 proteins that then function to increase the accessibility of Ser-155 to survival-promoting kinases. Ser-155 phosphorylation disrupts the binding of BAD to prosurvival Bcl-2 proteins and thereby promotes cell survival. These findings define a mechanism by which survival signals inactivate a proapoptotic Bcl-2 family member, and suggest a role for 14-3-3 proteins as cofactors that regulate sequential protein phosphorylation events.     

Iron overload in paediatrics undergoing cardiopulmonary bypass

Pathological changes in iron status are known to occur during bypass and will be superimposed upon physiological abnormalities in iron distribution, characteristic of the neonatal period. We have sought to define the severity of iron overload in these patients. Plasma samples from 65 paediatric patients undergoing cardiopulmonary bypass (CPB) were analysed for non-haem iron, total iron binding capacity, transferrin and bleomycin-detectable iron. Patients were divided into four age groups for analysis. Within each age group, patients who were in iron overload at any time point were statistically compared to those who were not. The most significant changes in iron chemistry were seen in the plasma of neonates, with 25% in a state of plasma iron overload. 18.5% of infants and 14.3% of children at 1-5 years were also in iron overload at some time point during CPB. No children over 5 years, however, went into iron overload. Increased iron saturation of transferrin eliminates its ability to bind reactive forms of iron and to act as an antioxidant. When transferrin is fully saturated with iron, reactive forms of iron are present in the plasma which can stimulate iron-driven oxidative reactions. Our data suggest that paediatric patients are at greater risk of iron overload during CPB, and that some form of iron chelation therapy may be advantageous to decrease oxidative stress.     

Genetic skeletal disorders of the fetus and infant: Pathologic and molecular findings in a series of 41 cases

BACKGROUND: Genetic skeletal disorders of the fetus and infant are a large group of genetic disorders, comprising the groups formerly assigned as skeletal dysplasias (osteochondrodysplasias), dysostoses, and malformation syndromes with a skeletal component. Genetic skeletal disorders may be prenatally detected by ultrasonography or result in intrauterine or early postnatal death, constituting one difficult diagnostic field met by the pathologist who performs the perinatal autopsy. METHODS: In this retrospective study, we have gathered radiologic, physical, histopathologic, and molecular data regarding 41 cases of genetic skeletal disorders diagnosed among 1980 fetal and perinatal autopsies over a 10‐year period. RESULTS: Our series of cases were classified according to the 2006 Nosology and Classification of Genetic Skeletal Disorders. The overall frequency of genetic skeletal disorders was 1:48 autopsies. The FGFR3 group and osteogenesis imperfecta type 2 were the more frequently encountered disorders. The mean gestational age at autopsy was 21.9 weeks (range, 12–37 weeks). A final diagnosis was obtained in 95% of cases. Genetic skeletal disorders were detected by prenatal ultrasound in 90% of cases, with a correct typing of the disorder achieved in only 34%. Molecular analysis was confirmative in 5 cases. CONCLUSIONS: The central role of the perinatal pathologist in collaboration with specialized services is essential for the correct interpretation of the radiologic, physical, and histopathologic findings, to accurately classify specific types of genetic skeletal disorders and enable genetic counseling. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.     

Synthesis of Novel Thiopurine Pyranonucleosides: Evaluation of Their Bioactivity

We report the synthesis of novel thiopurine pyranonucleosides. Direct coupling of silylated 6-mercaptopurine and 6-thioguanine with the appropriate pyranoses 1a–e via Vorbrüggen nucleosidation, gave the N-9 linked mercaptopurine 2a–e and thioguanine 4a–e nucleosides, while their N-7 substituted congeners 10a–e and 7a–e, were obtained through condensation of the same acetates with 6-chloro and 2-amino-6-chloropurines, followed by subsequent thionation. Nucleosides 3a–e, 5a–e, 8a–e, and 11a–e were evaluated for their cytostatic activity in three different tumor cell proliferative assays.     

Effects of particulate matter exposure on blood 5-hydroxymethylation: results from the Beijing truck driver air pollution study

Previous studies have reported epigenetic changes induced by environmental exposures. However, previous investigations did not distinguish 5-methylcytosine (5mC) from a similar oxidative form with opposite functions, 5-hydroxymethylcytosine (5hmC). Here, we measured blood DNA global 5mC and 5hmC by ELISA and used adjusted mixed-effects regression models to evaluate the effects of ambient PM₁₀ and personal PM_2.5 and its elemental components—black carbon (BC), aluminum (Al), calcium (Ca), potassium (K), iron (Fe), sulfur (S), silicon (Si), titanium (Ti), and zinc (Zn)—on blood global 5mC and 5hmC levels. The study was conducted in 60 truck drivers and 60 office workers in Beijing, China from The Beijing Truck Driver Air Pollution Study at 2 exams separated by one to 2 weeks. Blood 5hmC level (0.08%) was ∼83-fold lower than 5mC (6.61%). An inter-quartile range (IQR) increase in same-day PM₁₀ was associated with increases in 5hmC of 26.1% in office workers (P = 0.004), 20.2% in truck drivers (P = 0.014), and 21.9% in all participants combined (P < 0.001). PM₁₀ effects on 5hmC were increasingly stronger when averaged over 4, 7, and 14 d preceding assessment (up to 132.6% for the 14-d average in all participants, P < 0.001). PM₁₀ effects were also significant after controlling for multiple testing (family-wise error rate; FWER < 0.05). 5hmC was not correlated with personal measures of PM_2.5 and elemental components (FWER > 0.05). 5mC showed no correlations with PM₁₀, PM_2.5, and elemental components measures (FWER > 0.05). Our study suggests that exposure to ambient PM₁₀ affects 5hmC over time, but not 5mC. This finding demonstrates the need to differentiate 5hmC and 5mC in environmental studies of DNA methylation.     

“They Know,They Agree,but They Don’t Do”- The Paradox of Tuberculosis Case Notification by Private Practitioners in Alappuzha District,Kerala, India

Background

Despite being a recognized standard of tuberculosis (TB) care internationally, mandatory TB case notification brings forth challenges from the private sector. Only three TB cases were notified in 2013 by private practitioners compared to 2000 TB cases notified yearly from the public sector in Alappuzha district. The study objective was to explore the knowledge, opinion and barriers regarding TB Notification among private practitioners offering TB services in Alappuzha, Kerala state, India.

Methods & Findings

This was a mixed-methods study with quantitative (survey) and qualitative components conducted between December 2013 and July 2014. The survey, using a structured questionnaire, among 169 private practitioners revealed that 88% were aware of mandatory notification. All patient-related details requested in the notification form (except government-issued identification number) were perceived to be important and easy to provide by more than 80% of practitioners. While more than 95% felt that notification should be mandatory, punitive action in case of failure to notify was considered unnecessary by almost two third. General practitioners (98%) were more likely to be aware of notification than specialists (84 %). (P<0.01). Qualitative purposive personal interviews (n=34) were carried out among private practitioners and public health providers. On thematic framework analysis of the responses, barriers to TB notification were grouped into three themes: ‘private provider misconceptions about notification’, ‘patient confidentiality, and stigma and discrimination ’and ‘lack of cohesion and coordination between public and private sector’. Private practitioners did not consider it necessary to notify TB cases treated with daily regimen.

Conclusion

Communication strategies like training, timely dissemination of information of policy changes and one-to-one dialogue with private practitioners to dispel misconceptions may enhance TB notification. Trust building strategies like providing feedback about referred cases from private sector, health personnel visit or a liaison private doctor may ensure compliance to public health activities.