Derivation of factors for estimating the scatter of diagnostic x-rays from walls and ceiling slabs.

Computed tomography (CT) scanning rooms and interventional x-ray facilities with heavy workloads may require the installation of shielding to protect against radiation scattered from walls or ceiling slabs. This is particularly important for the protection of those operating x-ray equipment from within control cubicles who may be exposed to radiation scattered from the ceiling over the top of the protective barrier and round the side if a cubicle door is not included. Data available on the magnitude of this tertiary scatter from concrete slabs are limited.

Temporal changes in PTEN and mTORC2 regulation of hematopoietic stem cell self-renewal and leukemia suppression.

Pten deletion from adult mouse hematopoietic cells activates the PI3-kinase pathway, inducing hematopoietic stem cell (HSC) proliferation, HSC depletion, and leukemogenesis. Pten is also mutated in human leukemias, but rarely in early childhood leukemias. We hypothesized that this reflects developmental changes in PI3-kinase pathway regulation.

Portal hypertension in children and young adults with biliary atresia.

Objective: Biliary atresia (BA) frequently results in portal hypertension (PHT), complications of which lead to significant morbidity and mortality. The Childhood Liver Disease Research and Education Network was used to perform a cross-sectional multicentered analysis of PHT in children with BA.

Methods: Subjects with BA receiving medical management at a Childhood Liver Disease Research and Education Network site were enrolled.

Efficacy of fat-soluble vitamin supplementation in infants with biliary atresia.

Objective: Cholestasis predisposes to fat-soluble vitamin (FSV) deficiencies. A liquid multiple FSV preparation made with tocopheryl polyethylene glycol-1000 succinate (TPGS) is frequently used in infants with biliary atresia (BA) because of ease of administration and presumed efficacy. In this prospective multicenter study, we assessed the prevalence of FSV deficiency in infants with BA who received this FSV/TPGS preparation.

Reducing pediatric liver transplant complications: a potential roadmap for transplant quality improvement initiatives within North America.

Though robust clinical data are available within transplantation, these data are not used for broad-based, multicentered quality improvement initiates. This article describes a targeted quality improvement initiative within the Studies of Pediatric Liver Transplantation (SPLIT) Registry. Using standard statistical techniques and clinical expertise to adjust for data and statistical reliability, we identified the pediatric liver transplant centers in North America with the lowest hepatic artery thrombosis rate and biliary complication rates.

Increasing donor designation through black churches: results of a randomized trial.

Context: African Americans are disproportionately represented among those awaiting a transplant, but many are reluctant to donate their organs.

Objective: To test the effectiveness of using lay health advisors to increase organ donation among church members.

Design: Churches were pair-matched by average estimated income and size and then randomized to 1 of 2 interventions: one addressing organ donation and the other addressing increasing consumption of fruits and vegetables.

Reprogramming IgH isotype-switched B cells to functional-grade induced pluripotent stem cells.

Induced pluripotent stem cells (iPSCs) can be formed from somatic cells by a defined set of genetic factors; however, aberrant epigenetic silencing of the imprinted Dlk1-Dio3 gene cluster often hinders their developmental potency and ability to contribute to high-grade chimerism in mice. Here, we describe an approach that allows splenic B cells activated to undergo Ig heavy-chain (IgH) class-switch recombination (CSR) to be reprogrammed into iPSCs that contribute to high-grade chimerism in mice. Treatment of naïve splenic B cells in culture with anti-CD40 plus IL-4 induces IgH CSR from IgM to IgG1 and IgE.

Efficacy of and advocacy for postural screening in public schools.

Purpose: To investigate the efficacy of and advocacy for postural screening in public schools.

Methods: The results of postural screenings in 120 primary and secondary schools throughout one representative northeastern U.S.

Changing epidemiology of Clostridium difficile infection following the introduction of a national ribotyping-based surveillance scheme in England.

Background: Marked increases in Clostridium difficile infection (CDI) incidence, driven by epidemic strain spread, is a global phenomenon.

Methods: The Clostridium difficile Ribotyping Network (CDRN) was established in 2007 as part of enhanced CDI surveillance in England, to facilitate the recognition and control of epidemic strains. We report on changes in CDI epidemiology in England in the first 3 years of CDRN.

Current issues with standards in the measurement and documentation of human skeletal anatomy.

Digital modeling of human anatomy has become increasingly important and relies on well-documented quantitative anatomy literature. This type of documentation is common for the spine and pelvis; however, significant issues exist due to the lack of standardization in measurement and technique. Existing literature on quantitative anatomy for the spine and pelvis of white adults (aged 18-65 years, separated into decadal categories) was reviewed from the disciplines of anatomy, manipulative therapy, anthropometrics, occupational ergonomics, biomechanics and forensic science.

Incisional hernia recurrence through genomic profiling: a pilot study.

Purpose: Although situational risk factors for incisional hernia formation are known, the methods used to determine who would be most susceptible to develop one are unreliable. We hypothesized that patients with recurrent incisional hernias may possess unique gene expression profiles.

Methods: Skin and intact fascia were collected from 15 normal control (NC) patients with no hernia history and 18 patients presenting for recurrent incisional hernia (RH) repair.

Epidemiological survey of Clostridium difficile ribotypes in the North East of England during an 18-month period.

During an 18-month period, 1606 stool specimens from laboratory-confirmed cases of Clostridium difficile infection in the North East of England were ribotyped using unrestricted polymerase chain reaction. Of these, 87.6% grew C.

Pancreatic insufficiency is not a prevalent problem in Alagille syndrome.

Alagille syndrome (ALGS) is an inherited multisystem disorder in which pancreatic insufficiency (PI) has been regarded a minor but important clinical manifestation. As part of a multicenter prospective study, 42 patients with ALGS underwent fecal elastase (FE) measurement to screen for exocrine PI. FE measurements were normal (>200  μg/g) in 40 (95%) and indeterminate (100-200  μg/g) in 2 (5%).

The interplay between online and offline explorations of identity, relationships, and sex: a mixed-methods study with LGBT youth.

Although the Internet is commonly used by lesbian, gay, bisexual, and transgender (LGBT) youth to explore aspects of sexual health, little is known about how this usage relates to offline explorations and experiences. This study used a mixed-methods approach to investigate the interplay between online and offline explorations of multiple dimensions of sexual health, which include sexually transmitted infections, sexual identities, romantic relationships, and sexual behaviors. A diverse community sample of 32 LGBT youth (ages 16-24) completed semi-structured interviews, which were transcribed and then qualitatively coded to identify themes.

Control of timing, rate and bursts of hippocampal place cells by dendritic and somatic inhibition.

A consortium of inhibitory neurons control the firing patterns of pyramidal cells, but their specific roles in the behaving animal are largely unknown. We performed simultaneous physiological recordings and optogenetic silencing of either perisomatic (parvalbumin (PV) expressing) or dendrite-targeting (somatostatin (SOM) expressing) interneurons in hippocampal area CA1 of head-fixed mice actively moving a treadmill belt rich with visual-tactile stimuli. Silencing of either PV or SOM interneurons increased the firing rates of pyramidal cells selectively in their place fields, with PV and SOM interneurons having their largest effect during the rising and decaying parts of the place field, respectively.

Cancer stem cells: impact, heterogeneity, and uncertainty.

The differentiation of tumorigenic cancer stem cells into nontumorigenic cancer cells confers heterogeneity to some cancers beyond that explained by clonal evolution or environmental differences. In such cancers, functional differences between tumorigenic and nontumorigenic cells influence response to therapy and prognosis. However, it remains uncertain whether the model applies to many, or few, cancers due to questions about the robustness of cancer stem cell markers and the extent to which existing assays underestimate the frequency of tumorigenic cells.

Structural characterization of closely related O-antigen lipopolysaccharide (LPS) chain length regulators.

The surface O-antigen polymers of gram-negative bacteria exhibit a modal length distribution that depends on dedicated chain length regulator periplasmic proteins (polysaccharide co-polymerases, PCPs) anchored in the inner membrane by two transmembrane helices. In an attempt to determine whether structural changes underlie the O-antigen modal length specification, we have determined the crystal structures of several closely related PCPs, namely two chimeric PCP-1 family members solved at 1.6 and 2.

The use of rpoB sequence analysis in the differentiation of Mycobacterium abscessus and Mycobacterium chelonae: a critical judgement in cystic fibrosis?

Individuals suffering from fibrocystic disease may acquire non-tuberculous mycobacteria as colonizing or infecting organisms. Mycobacterium abscessus is of particular concern because it may be very difficult to eradicate and may mitigate against lung transplantation. However, this species may be difficult to reliably differentiate from the closely related M.

A comparison of propofol and amobarbital for use in the Wada test.

129 Wada procedures were reviewed to examine the suitability of propofol (n=54) as a replacement to amobarbital (n=75) for use as an anaesthetic in the Wada test. Suitability was considered with respect to length of hemiplegia induced, the frequency of side effects and patient memory scores. Data was retrospectively collected from records of patients who had undergone the Wada procedure between 2004 and 2009 in Beaumont Hospital, Dublin.

Psychopathology and thought suppression: a quantitative review.

Recent theories of psychopathology have suggested that thought suppression intensifies the persistence of intrusive thoughts, and proposed that difficulty with thought suppression may differ between groups with and without psychopathology. The current meta-analytic review evaluates empirical evidence for difficulty with thought suppression as a function of the presence and specific type of psychopathology. Based on theoretical proposals from the psychopathology literature, diagnosed and analogue samples were expected to show greater recurrence of intrusive thoughts during thought suppression attempts than non-clinical samples.

Relationship between sleep problems and health-related quality of life among pediatric liver transplant recipients.

Among adult liver transplant recipients (LTRs), sleep disturbances and fatigue are common. Sleep problems following pediatric liver transplantation may contribute to daytime fatigue and lower health-related quality of life (HRQOL). The aim of this cross-sectional study was to determine the impact of sleep problems on the HRQOL of pediatric LTRs using validated measures.

Observations on clustered synaptic plasticity and highly structured input patterns.

In this issue of Neuron, Makino and Malinow and Kleindienst et al. present evidence of a behaviorally induced form of synaptic plasticity that would encourage the development of fine-scale structured input patterns and the binding of features within single neurons.

Health status of children alive 10 years after pediatric liver transplantation performed in the US and Canada: report of the studies of pediatric liver transplantation experience.

Objectives: To determine clinical and health-related quality of life outcomes, and to derive an "ideal" composite profile of children alive 10 years after pediatric liver transplantation (LT) performed in the US and Canada.

Study Design: This was a multicenter cross-sectional analysis characterizing patients enrolled in the Studies of Pediatric Liver Transplantation database registry who have survived >10 years from LT.

Results: A total of 167 10-year survivors were identified, all of whom received daily immunosuppression therapy.

Immature B cells preferentially switch to IgE with increased direct Sμ to Sε recombination.

Immunoglobulin heavy chain (IgH) class-switch recombination (CSR) replaces initially expressed Cμ (IgM) constant regions (C(H)) exons with downstream C(H) exons. Stimulation of B cells with anti-CD40 plus interleukin-4 induces CSR from Cμ to Cγ1 (IgG1) and Cε (IgE), the latter of which contributes to the pathogenesis of atopic diseases. Although Cε CSR can occur directly from Cμ, most mature peripheral B cells undergo CSR to Cε indirectly, namely from Cμ to Cγ1, and subsequently to Cε.