University of Medicine and Dentistry of New Jersey

About: University of Medicine and Dentistry of New Jersey is a based out in . It is known for research contribution in the topics: Population & Poison control. The organization has 14634 authors who have published 19610 publications receiving 1041794 citations.

Activation of the Mammalian Target of Rapamycin (mTOR) is Essential for Oligodendrocyte Differentiation

Abstract: Although both extrinsic and intrinsic factors have been identified that orchestrate the differentiation and maturation of oligodendrocytes, less is known about the intracellular signaling pathways that control the overall commitment to differentiate. Here, we provide evidence that activation of the mammalian target of rapamycin (mTOR) is essential for oligodendrocyte differentiation. Specifically, mTOR regulates oligodendrocyte differentiation at the late progenitor to immature oligodendrocyte transition as assessed by the expression of stage specific antigens and myelin proteins including MBP and PLP. Furthermore, phosphorylation of mTOR on Ser 2448 correlates with myelination in the subcortical white matter of the developing brain. We demonstrate that mTOR exerts its effects on oligodendrocyte differentiation through two distinct signaling complexes, mTORC1 and mTORC2, defined by the presence of the adaptor proteins raptor and rictor, respectively. Disrupting mTOR complex formation via siRNA mediated knockdown of raptor or rictor significantly reduced myelin protein expression in vitro. However, mTORC2 alone controlled myelin gene expression at the mRNA level, whereas mTORC1 influenced MBP expression via an alternative mechanism. In addition, investigation of mTORC1 and mTORC2 targets revealed differential phosphorylation during oligodendrocyte differentiation. In OPC-DRG cocultures, inhibiting mTOR potently abrogated oligodendrocyte differentiation and reduced numbers of myelin segments. These data support the hypothesis that mTOR regulates commitment to oligodendrocyte differentiation before myelination.

Rheb is a Critical Regulator of Autophagy during Myocardial Ischemia: Pathophysiological Implications in Obesity and Metabolic Syndrome

Abstract: Background—Rheb is a GTP-binding protein that promotes cell survival and mediates the cellular response to energy deprivation (ED). The role of Rheb in the regulation of cell survival during ED has...

Peer Influences on Adolescent Cigarette Smoking: A Theoretical Review of the Literature

Abstract: This article reviews several classes of theories to elucidate the relationship between adolescent cigarette smoking and friends' cigarette smoking. Perceived influence theories hinge upon an adolescent's perception of friends' smoking behavior. External influence theories are those in which friends' smoking behavior overtly influences adolescent smoking. Group level theories examine how differences at the level of subculture, gender, and race/ethnicity influence the relationship under study. Network theories are also discussed. A model integrating relevant theories into a longitudinal model representing friend influences on adolescent smoking is presented, along with implications of the results presented for adolescent tobacco prevention programs.

Exposure to Di-(2-Ethylhexyl) Phthalate Among Premature Neonates in a Neonatal Intensive Care Unit

Abstract: Objective. Premature neonates who spend time in a neonatal intensive care unit may be at increased risk of adverse health effects from exposure to di-(2-ethylhexyl) phthalate (DEHP) because of their increased risk of high exposure, their small body size, and their physical condition. DEHP, a reproductive toxicant in animals, is a major component in polyvinyl chloride (PVC) plastics, which are frequently used in medical tubing and blood storage bags. DEHP is not covalently bound to PVC, and it may be easily released from the PVC medical devices. The objective of this study was to determine whether premature infants who undergo medical procedures, such as blood transfusions, intravenous therapy, enteral and parenteral nutrition support, and dialysis, are at increased risk of exposure to DEHP than the general population. Because of their smaller size, children and especially premature and small infants may receive a larger dose of DEHP on a milligram per kilogram basis than adults when the same-size medical device is used for all ages. Methods. Premature neonates who seemed to have the potential to be on intravenous infusion for >2 weeks and were expected to survive were eligible for enrollment in the study. We assessed exposure to DEHP in 6 premature newborns by measuring in 41 urine samples the levels of 3 DEHP metabolites: mono-(2-ethylhexyl) phthalate (mEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (mEOHP). Results. mEHHP and mEOHP were detected in all 41 urine samples, and mEHP was detected in 33. Because only 33 of the samples had detectable amounts for all 3 metabolites, statistical analyses were limited to those 33. The levels of all 3 DEHP metabolites varied widely, and the urinary mean and median concentrations of mEOHP and mEHHP were 1 order of magnitude higher than those for mEHP. Furthermore, the geometric mean urinary concentrations of mEOHP (1617 ng/mL), mEHHP (2003 ng/mL), and mEHP (100 ng/mL) in these 6 premature infants who underwent intensive therapeutic interventions were found to be severalfold higher than in the US general population (for mEHP, geometric mean in those 6 years and older was 3.43 ng/mL). Conclusions. This study provides the first quantitative evidence confirming that newborns who undergo intensive therapeutic medical interventions are exposed to higher concentrations of DEHP than the general population. Although the overall benefits of medical procedures using PVC devices outweigh the risks associated with exposure to DEHP, more research is needed to determine whether infants and children who undergo intensive therapeutic interventions using DEHP-containing devices are at higher risk for altered health outcomes than infants and children who undergo similar treatments but are not potentially exposed to DEHP.