Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic disorder caused by mutation of the NF1 tumor suppressor gene. Spinal deformities are common skeletal manifestations in patients with NF1. To date, the mechanism of vertebral abnormalities remains unclear because of the lack of appropriate animal models for the skeletal manifestations of NF1. In the present study, we report a novel murine NF1 model, Nf1flox/−;Col2.3Cre+ mice. These mice display short vertebral segments. In addition, a significant reduction in cortical and trabecular bone mass of the vertebrae was observed in Nf1flox/−;Col2.3Cre+ mice as measured by dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT). Peak stress and peak load were also significantly reduced in Nf1flox/−;Col2.3Cre+ mice as compared to controls. Furthermore, the lumbar vertebrae showed enlargement of the inter-vertebral canal, a characteristic feature of lumbar vertebrae in NF1 patients. Finally, histologic analysis demonstrated increased numbers of osteoclasts and decreased numbers of osteoblasts in the vertebrae of Nf1flox/−;Col2.3Cre+ mice in comparison to controls. In summary, Nf1flox/−;Col2.3Cre+ mice demonstrate multiple structural and functional abnormalities in the lumbar vertebrae which recapitulate the dystrophic vertebral changes in NF1 patients. This novel murine model provides a platform to understand the cellular and molecular mechanisms underlying the pathogenesis of spinal deficits in NF1 patients.

Background

Previous reports on the prevalence of neural tube defects (NTDs) in China did not include cases of NTDs that were less than 28 weeks of gestational age (GA) and hence did not accurately reflect the total prevalence of NTDs or the geographic and urban–rural disparities in their prevalence. This article includes cases of NTDs that were less than 28 weeks of GA.

Methods

Data used in this study were collected from 2006 to 2008 using a nationwide hospital-based registry, the Chinese Birth Defects Monitoring Network. The total prevalence ratio (PR) of NTDs and their subtypes, the ratios of PR (PRR), and 95% confidence intervals (CI) were used to analyse geographic disparities at both the regional (north, south) and provincial levels and to analyse disparities between rural and urban areas.

Results

Overall, the total PR of NTDs was 14.0 per 10,000 births. The PRR of NTDs of rural women between the north and south region was 2.26 (95% CI: 2.04-2.52), which was much higher than that of urban women (PRR: 1.56, 95% CI: 1.41-1.72). The three subtypes of NTDs had different geographic distribution at the level of province. The urban–rural PRR of NTDs was 2.14 (95% CI: 1.94-2.34) in the north but only 1.47 (95% CI: 1.31-1.66) in the south.

Conclusions

There is a high total prevalence of NTDs, which remains one of the major public health concerns in China. Eliminating the geographic and urban–rural disparities in the disease burden is a priority for future intervention.

The chloromethylation of activated carbon is described. Chloromethylation was found to produce a carbon derivative with a surface area of 1310 m2/g and no significant change in the pore structure. The product was found to contain ~1.5 mmole of –CH2Cl groups per g of material, similar to the functional density reported in the original Merrifield resin synthesis. Displacement of the benzylic chloride was achieved by treating this material with an excess of sodium thiosulfate in refluxing aqueous methanol. The resulting Bunte salt was then hydrolyzed by treatment with warm 3 M HCl to afford the corresponding thiol (“AC-CH2-SH”) cleanly and in high yield. AC-CH2-SH was found to be an effective heavy metal sorbent, efficiently capturing Hg, Pb, Ag, and Cu. Sorption kinetics were rapid, with equilibrium achieved in less than 30 minutes.

Background

The human paraoxonase (PON) gene family has three isoforms: PON1, PON2 and PON3. These genes are implicated as potential risk factors of cerebrovascular disease and can prevent oxidative modification of low-density lipoproteins and atherosclerosis. This study evaluated the association between the genetic variants of all three PON genes and the risks of total stroke, ischemic stroke and hemorrhagic stroke in the Han Chinese population.

Methods

A total of 1016 subjects were recruited, including 508 healthy controls and 498 patients (328 with ischemic stroke and 170 with hemorrhagic stroke). A total of 11 single nucleotide polymorphisms (SNPs) covering the PON genes were genotyped for statistical analysis. Two of the 11 SNPs (rs662 and rs854560) were contextualized in a meta-analysis of ischemic stroke.

Results

The presence of rs705381 (−162) in the promoter region of PON1 was significantly associated with total stroke (Padjusted = 0.0007, OR = 0.57 [95% CI = 0.41-0.79]) and ischemic stroke (Padjusted = 0.0017, OR = 0.54 [95% CI = 0.37-0.79]) when analyzed using a dominant model, but was not associated with hemorrhagic stroke. There was also a nominal association between rs854571 (−824) and total stroke. Meta-analysis demonstrated a significant nominal association between rs662 and ischemic stroke, but there was no evidence of an association between rs662 and ischemic stroke risk in a single site association study.

Conclusions

These findings indicate that polymorphisms of PON1 gene may be a risk factor of stroke.

Background

We present a compendium of N-ethyl-N-nitrosourea (ENU)-induced mouse mutations, identified in our laboratory over a period of 10 years either on the basis of phenotype or whole genome and/or whole exome sequencing, and archived in the Mutagenetix database. Our purpose is threefold: 1) to formally describe many point mutations, including those that were not previously disclosed in peer-reviewed publications; 2) to assess the characteristics of these mutations; and 3) to estimate the likelihood that a missense mutation induced by ENU will create a detectable phenotype.

Findings

In the context of an ENU mutagenesis program for C57BL/6J mice, a total of 185 phenotypes were tracked to mutations in 129 genes. In addition, 402 incidental mutations were identified and predicted to affect 390 genes. As previously reported, ENU shows strand asymmetry in its induction of mutations, particularly favoring T to A rather than A to T in the sense strand of coding regions and splice junctions. Some amino acid substitutions are far more likely to be damaging than others, and some are far more likely to be observed. Indeed, from among a total of 494 non-synonymous coding mutations, ENU was observed to create only 114 of the 182 possible amino acid substitutions that single base changes can achieve. Based on differences in overt null allele frequencies observed in phenotypic vs. non-phenotypic mutation sets, we infer that ENU-induced missense mutations create detectable phenotype only about 1 in 4.7 times. While the remaining mutations may not be functionally neutral, they are, on average, beneath the limits of detection of the phenotypic assays we applied.

Conclusions

Collectively, these mutations add to our understanding of the chemical specificity of ENU, the types of amino acid substitutions it creates, and its efficiency in causing phenovariance. Our data support the validity of computational algorithms for the prediction of damage caused by amino acid substitutions, and may lead to refined predictions as to whether specific amino acid changes are responsible for observed phenotypes. These data form the basis for closer in silico estimations of the number of genes mutated to a state of phenovariance by ENU within a population of G3 mice.

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutation of PKD1 and PKD2 that encode polycystin-1 and polycystin-2. Polycystin-1 is tyrosine phosphorylated and modulates multiple signaling pathways including AP-1, but the identity of the phosphatases regulating polycystin-1 are previously uncharacterized. Here we identify members of the LAR protein tyrosine phosphatase (RPTP) superfamily as members of the polycystin-1complex mediated through extra- and intracellular interactions. The first extracellular PKD1 domain of polycystin-1 interacts with the first Ig domain of RPTPσ, while the polycystin-1 C-terminus of polycystin-1 interacts with the regulatory D2 phosphatase domain of RPTPγ. Additional homo- and heterotypic interactions between RPTPs recruit RPTPδ The multimeric polycystin protein complex is found localised in cilia. RPTPσ and RPTPδ are also part of a polycystin-1/E-cadherin complex known to be important for early events in adherens junction stabilisation. The interaction between polycystin-1 and RPTPγ is disrupted in ADPKD cells, while RPTPσ and RPTPδ remain closely associated with E-cadherin, largely in an intracellular location. The polycystin-1 C-terminus is an in vitro substrate of RPTPγ, which dephosphorylates the c-Src phosphorylated Y4237 residue and activates AP1-mediated transcription. The data identify RPTPs as novel interacting partners of the polycystins both in cilia and at adhesion complexes and demonstrate RPTPγ phosphatase activity is central to the molecular mechanisms governing polycystin-dependent signaling.

The intricately regulated Ras pathway coordinates multiple kit-ligand induced mast cell functions, including chemotaxis, proliferation and degranulation. However, the intracellular proteins that modulate the intensity and duration of SCF-induced signals and the consequent cellular response are incompletely understood. Scaffolding proteins coordinate the spatial organization of MAPK proteins that may potentiate and/or inhibit cell functions. The Kinase Suppressor of Ras (KSR1) protein is known to function as a molecular scaffold and coordinates the organization of Raf/Mek/Erk in response to receptor tyrosine kinases. However, the impact of KSR1 in myeloid mast cell functions and in response to stem cell factor remains unknown. In the present study, we investigated the role of KSR1 in regulating cellular functions of bone marrow derived mast cells (BMMCs) of KSR1 deficient (−/−) mice. Genetic disruption of KSR1 resulted in both striking reductions in kit-ligand mediated proliferation and degranulation that are commonly attributed to MAPK signals. Surprisingly, disruption of the KSR1 scaffold also resulted in a decline in migration that is generally not linked to Raf-Erk signals. We found that loss of KSR1 does impact the biochemical activation of Pak kinase, a kinase that is known to modulate Raf-Erk signals and also F-actin polymerization key to mast cell migration. Collectively, these studies demonstrate that the scaffolding protein KSR1 has an important role in multiple kit-ligand mediated mast cell functions. This study elucidates varied mast cell physiological functions for KSR1, including those related to cytoskeletal organization, and it suggests a novel molecular target for attenuating mast cell-mediated inflammation.

Background

Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. To date the etiology of this disorder is poorly understood. Studies suggest that astrocytes play critical roles in neural plasticity by detecting neuronal activity and modulating neuronal networks. Recently, a number of studies suggested that an abnormal function of glia/astrocytes may be involved in the development of autism. However, there is yet no direct evidence showing how astrocytes develop in the brain of autistic individuals.

Methods

Study subjects include brain tissue from autistic subjects, BTBR T + tfJ (BTBR) and Neuroligin (NL)-3 knock-down mice. Western blot analysis, Immunohistochemistry and confocal microscopy studies have be used to examine the density and morphology of astrocytes, as well as Wnt and β-catenin protein expression.

Results

In this study, we demonstrate that the astrocytes in autisitcsubjects exhibit significantly reduced branching processes, total branching length and cell body sizes. We also detected an astrocytosis in the frontal cortex of autistic subjects. In addition, we found that the astrocytes in the brain of an NL3 knockdown mouse exhibited similar alterations to what we found in the autistic brain. Furthermore, we detected that both Wnt and β-catenin proteins are decreased in the frontal cortex of autistic subjects. Wnt/β-catenin pathway has been suggested to be involved in the regulation of astrocyte development.

Conclusions

Our findings imply that defects in astrocytes could impair neuronal plasticity and partially contribute to the development of autistic-like behaviors in both humans and mice. The alteration of Wnt/β-catenin pathway in the brain of autistic subjects may contribute to the changes of astrocytes.

An improved synthesis of a 3,4 hydroxypyridinone (HOPO) functionalized mesoporous silica is described. Higher 3,4-HOPO monolayer ligand loadings have been achieved, resulting in better performance. Performance improvements were demonstrated with the capture of U(VI) from human blood, plasma and filtered river water.

People living in endemic areas often habour several malaria infections at once. High-resolution genotyping can distinguish between infections by detecting the presence of different alleles at a polymorphic locus. However the number of infections may not be accurately counted since parasites from multiple infections may carry the same allele. We use simulation to determine the circumstances under which the number of observed genotypes are likely to be substantially less than the number of infections present and investigate the performance of two methods for estimating the numbers of infections from high-resolution genotyping data.

The simulations suggest that the problem is not substantial in most datasets: the disparity between the mean numbers of infections and of observed genotypes was small when there was 20 or more alleles, 20 or more blood samples, a mean number of infections of 6 or less and where the frequency of the most common allele was no greater than 20%. The issue of multiple infections carrying the same allele is unlikely to be a major component of the errors in PCR-based genotyping.

Simulations also showed that, with heterogeneity in allele frequencies, the observed frequencies are not a good approximation of the true allele frequencies. The first method that we proposed to estimate the numbers of infections assumes that they are a good approximation and hence did poorly in the presence of heterogeneity. In contrast, the second method by Li et al estimates both the numbers of infections and the true allele frequencies simultaneously and produced accurate estimates of the mean number of infections.

ZBTB1, a BTB-ZF family member, is essential for T cell development and for complete B and NK cell differentiation.

In this study, we describe a chemically induced mouse mutation that caused a complete and cell-intrinsic T cell deficiency. Development of other lymphoid lineages was also partially impaired and was severely compromised under competitive conditions. Positional cloning, retroviral transduction, and a somatic reversion event revealed that the causative mutation lay within Zbtb1 (zinc finger and BTB domain containing 1), a gene conserved throughout vertebrate evolution. Our data establish ZBTB1 as a critical determinant of T cell development and lymphopoiesis in general, most likely by acting as a transcriptional regulator.

In order to produce petroleum alternatives from biomass, a significant amount of research has been focused on oils from microalgae due to their origin, which would not affect food availability. Nanoporous hybrid catalysts composed of ns Al2O3 and zeolites have been proven to be very useful compared to traditional catalysts in hydrotreating (HT), hydrocracking (HC), and catalytic cracking (CC) of large molecules. To evaluate the reaction scheme and products from model isoprenoid compounds of microalgae oil, nanoporous hybrid catalyst technologies (CC: ns Al2O3/H-USY and ns Al2O3/H-GaAlMFI; HC: [Ni-Mo/γ-Al2O3]/ns Al2O3/H-beta) were studied. The major product from CC on ns Al2O3/H-USY was highly aromatic gasoline, while the product from HC was half-isoparaffinic/olefinic kerosene. Although more than 50 wt% of the products from HT/CC on the USY catalyst was liquefied petroleum gas due to overcracking, the product from HT/CC on the MFI catalyst was high-octane-number gasoline. Delightfully, the product from HT/HC was kerosene and its average number was 11, with more than 80 wt% being isoparaffinic. As a result, it was demonstrated that hydrotreating may convert isoprenoid oil from microalgae over nanoporous hybrid catalysts into a variety of products.

Background

Since 2000, the Chinese government has implemented an intervention program to reduce maternal mortality and eliminate neonatal tetanus in accordance with the Millennium Development Goals 5. To assess the effectiveness of this intervention program, we analyzed the level, trend and reasons defining the maternal mortality ratio (MMR) in the 1,000 priority counties before and after implementation of the intervention between 1999 and 2007.

Methodology/Principal Findings

The data was obtained from the National Maternal and Child Health Routine Reporting System. The intervention included providing basic and emergency obstetric equipment and supplies to local medical hospitals, and also included providing professional training to local obstetric doctors, development of obstetric emergency centers and “green channel” express referral networks, reducing or waiving the cost of hospital delivery, and conducting community health education. Based on the initiation time of the intervention and the level of poverty, 1,000 counties, containing a total population of 300 million, were categorized into three groups. MMR significantly decreased by about 50%, with an average reduction rate of 9.24%, 16.06%, and 18.61% per year in the three county groups, respectively. The hospital delivery rate significantly increased. Obstetric hemorrhage was the leading cause of maternal deaths and significantly declined, with an average decrease in the MMR of 11.25%, 18.03%, and 24.90% per year, respectively. The magnitude of the MMR, the average reduction rate of the MMR, and the occurrence of the leading causes of death were closely associated with the percentage of poverty.

Conclusions/Significance

The intervention program implemented by the Chinese government has significantly reduced the MMR in mid-western China, suggesting that well-targeted interventions could be an efficient strategy to reducing MMR in resource-poor areas. Reduction of the MMR not only depends on conducting proven interventions, but also relies on economic development in rural areas with a high burden of maternal death.

Background

Radiation-induced lung injury (RILI) is an important dose-limiting toxicity during thoracic radiotherapy. The purpose of this study is to investigate single photon emission computed tomography (SPECT) perfusion-weighted functional dose-volume histogram (FDVH) for predicting RILI in non-small cell lung cancer (NSCLC) patients treated with definitive chemoradiotherapy.

Methods

Fifty-seven locally advanced NSCLC patients receiving chemoradiotherapy were enrolled prospectively. Patients had treatment scans and dose calculations to provide a standard dose-volume histogram (DVH). Fusion of SPECT and computed tomography scans provided perfusion-weighted FDVH and associated functional dosimetric parameters (relative volumes of functional lung receiving more than a threshold dose of 5 – 60 Gy at increments of 5 Gy [FV5 – FV60]). The predictive abilities of FDVH and DVH were calculated and compared based on the area under receiver operating characteristic (ROC) curve (AUC).

Results

The accumulative incidence of ≥ 2 grade RILI was 19.3% with a median follow-up of 12 months. Univariate analysis showed that the functional (FV5 – FV60) and standard (V5 – V40) parameters were associated with RILI (all value of p < 0.05). Close correlations between a variety of functional and standard parameters were found. By ROC curve analysis, functional metrics (AUCs were 0.784 – 0.869) provided similarly (p value 0.233 – 1.000) predictive outcome to standard metrics (AUCs were 0.695 – 0.902) in lower – median dose level parameters (FV5 – FV40). However, FDVH seemed to add some predictive value in higher dose level, the best statistical significance for comparing FV60 with V60 was 0.693 vs. 0.511 (p = 0.055).

Conclusions

Functional metrics are identified as reliable predictors for RILI, however, this observation still needs to be further verified using a larger sample size.

Prostate cancer develops through a stochastic mechanism whereby pre-cancerous lesions on occasion progress to multifocal adenocarcinoma. Analysis of human benign and cancer prostate tissues revealed heterogeneous loss of TGF-β signaling in the cancer associated stromal fibroblastic cell compartment. To test the hypothesis that prostate cancer progression is dependent on the heterogeneous TGF-β responsive microenvironment, a tissue recombination experiment was designed where the ratio of TGF-β responsive and nonresponsive stromal cells were varied. While 100% TGF-β responsive stromal cells supported benign prostate growth and 100% TGF-β non-responsive stromal cells resulted in pre-cancerous lesions, only the mixture of TGF-β responsive and nonresponsive stromal cells resulted in adenocarcinoma. A computational model was used to resolve a mechanism of tumorigenic progression where proliferation and invasion occur in two independent steps mediated by distinct stromally derived paracrine signals produced by TGF-β non-responsive and responsive stromal cells. Complex spatial relationships of stromal and epithelial cells were incorporated into the model based on experimental data. Informed by incorporation of experimentally derived spatial parameters for complex stromal-epithelial relationships, the computational model indicated ranges for the relative production of paracrine factors by each cell type and provided bounds for the diffusive range of the molecules. Since SDF-1 satisfied model predictions for an invasion promoting paracrine factor, a more focused computational model was subsequently used to investigate if SDF-1 was the invasion signal. Simulations replicating SDF-1 expression data revealed the requirement for cooperative SDF-1 expression, a prediction supported biologically by heterotypic stromal IL-1β signaling between fibroblastic cell populations. The cancer stromal field effect supports a functional role for the unaltered fibroblasts as a cooperative mediator of cancer progression.

Although the pathogenic mechanisms that underlie autism are not well understood, there is evidence showing that metabotropic and ionotropic glutamate receptors are hyper-stimulated and the GABAergic system is hypo-stimulated in autism. Memantine is an uncompetitive antagonist of NMDA receptors and is widely prescribed for treatment of Alzheimer's disease treatment. Recently, it has been shown to improve language function, social behavior, and self-stimulatory behaviors of some autistic subjects. However the mechanism by which memantine exerts its effect remains to be elucidated. In this study, we used cultured cerebellar granule cells (CGCs) from Fmr1 knockout (KO) mice, a mouse model for fragile X syndrome (FXS) and syndromic autism, to examine the effects of memantine on dendritic spine development and synapse formation. Our results show that the maturation of dendritic spines is delayed in Fmr1-KO CGCs. We also detected reduced excitatory synapse formation in Fmr1-KO CGCs. Memantine treatment of Fmr1-KO CGCs promoted cell adhesion properties. Memantine also stimulated the development of mushroom-shaped mature dendritic spines and restored dendritic spine to normal levels in Fmr1-KO CGCs. Furthermore, we demonstrated that memantine treatment promoted synapse formation and restored the excitatory synapses to a normal range in Fmr1-KO CGCs. These findings suggest that memantine may exert its therapeutic capacity through a stimulatory effect on dendritic spine maturation and excitatory synapse formation, as well as promoting adhesion of CGCs.

Skeletal abnormalities including scoliosis, tibial dysplasia, sphenoid wing dysplasia, and decreased bone mineral density (BMD) are associated with neurofibromatosis type 1 (NF1). We report the cellular phenotype of NF1 human-derived osteoclasts and compare the in vitro findings with the clinical phenotype.

Functional characteristics (e.g. osteoclast formation, migration, adhesion, resorptive capacity) and cellular mechanistic alterations (e.g. F-actin polymerization, MAPK phosphorylation, RhoGTPase activity) from osteoclasts cultured from peripheral blood of individuals with NF1 (N=75) were assessed. Osteoclast formation was compared to phenotypic, radiologic, and biochemical data.

NF1 osteoprogenitor cells demonstrated increased osteoclast forming capacity. Human NF1-derived osteoclasts demonstrated increased migration, adhesion, and in vitro bone resorption. These activities coincided with increased actin belt formation and hyperactivity in MAPK and RhoGTPase pathways. Although osteoclast formation was increased, no direct correlation of osteoclast formation with BMD, markers of bone resorption, or the clinical skeletal phenotype was observed suggesting that osteoclast formation in vitro cannot directly predict NF1 skeletal phenotypes.

While NF1 haploinsufficiency produces a generalized osteoclast gain-in-function and may contribute to increased bone resorption, reduced BMD, and focal skeletal defects associated with NF1, additional and perhaps local modifiers are likely required for the development of skeletal abnormalities in NF1.

Background

Spinal Muscular Atrophy (SMA) is a neurodegenerative motor neuron disorder resulting from a homozygous mutation of the survival of motor neuron 1 (SMN1) gene. The gene product, SMN protein, functions in RNA biosynthesis in all tissues. In humans, a nearly identical gene, SMN2, rescues an otherwise lethal phenotype by producing a small amount of full-length SMN protein. SMN2 copy number inversely correlates with disease severity. Identifying other novel biomarkers could inform clinical trial design and identify novel therapeutic targets.

Objective:

To identify novel candidate biomarkers associated with disease severity in SMA using unbiased proteomic, metabolomic and transcriptomic approaches.

Materials and Methods:

A cross-sectional single evaluation was performed in 108 children with genetically confirmed SMA, aged 2–12 years, manifesting a broad range of disease severity and selected to distinguish factors associated with SMA type and present functional ability independent of age. Blood and urine specimens from these and 22 age-matched healthy controls were interrogated using proteomic, metabolomic and transcriptomic discovery platforms. Analyte associations were evaluated against a primary measure of disease severity, the Modified Hammersmith Functional Motor Scale (MHFMS) and to a number of secondary clinical measures.

Results

A total of 200 candidate biomarkers correlate with MHFMS scores: 97 plasma proteins, 59 plasma metabolites (9 amino acids, 10 free fatty acids, 12 lipids and 28 GC/MS metabolites) and 44 urine metabolites. No transcripts correlated with MHFMS.

Discussion

In this cross-sectional study, “BforSMA” (Biomarkers for SMA), candidate protein and metabolite markers were identified. No transcript biomarker candidates were identified. Additional mining of this rich dataset may yield important insights into relevant SMA-related pathophysiology and biological network associations. Additional prospective studies are needed to confirm these findings, demonstrate sensitivity to change with disease progression, and assess potential impact on clinical trial design.

Trial Registry

Clinicaltrials.gov NCT00756821.

Luis Montaner and colleagues retrospectively apply a potential capacity-saving CD4 count prediction tool to a cohort of HIV patients on antiretroviral therapy.

Background

Global programs of anti-HIV treatment depend on sustained laboratory capacity to assess treatment initiation thresholds and treatment response over time. Currently, there is no valid alternative to CD4 count testing for monitoring immunologic responses to treatment, but laboratory cost and capacity limit access to CD4 testing in resource-constrained settings. Thus, methods to prioritize patients for CD4 count testing could improve treatment monitoring by optimizing resource allocation.

Methods and Findings

Using a prospective cohort of HIV-infected patients (n = 1,956) monitored upon antiretroviral therapy initiation in seven clinical sites with distinct geographical and socio-economic settings, we retrospectively apply a novel prediction-based classification (PBC) modeling method. The model uses repeatedly measured biomarkers (white blood cell count and lymphocyte percent) to predict CD4+ T cell outcome through first-stage modeling and subsequent classification based on clinically relevant thresholds (CD4+ T cell count of 200 or 350 cells/µl). The algorithm correctly classified 90% (cross-validation estimate = 91.5%, standard deviation [SD] = 4.5%) of CD4 count measurements <200 cells/µl in the first year of follow-up; if laboratory testing is applied only to patients predicted to be below the 200-cells/µl threshold, we estimate a potential savings of 54.3% (SD = 4.2%) in CD4 testing capacity. A capacity savings of 34% (SD = 3.9%) is predicted using a CD4 threshold of 350 cells/µl. Similar results were obtained over the 3 y of follow-up available (n = 619). Limitations include a need for future economic healthcare outcome analysis, a need for assessment of extensibility beyond the 3-y observation time, and the need to assign a false positive threshold.

Conclusions

Our results support the use of PBC modeling as a triage point at the laboratory, lessening the need for laboratory-based CD4+ T cell count testing; implementation of this tool could help optimize the use of laboratory resources, directing CD4 testing towards higher-risk patients. However, further prospective studies and economic analyses are needed to demonstrate that the PBC model can be effectively applied in clinical settings.

Please see later in the article for the Editors' Summary

Editors' Summary

Background

AIDS has killed nearly 30 million people since 1981, and about 34 million people (most of them living in low- and middle-income countries) are now infected with HIV, the virus that causes AIDS. HIV destroys immune system cells (including CD4 cells, a type of lymphocyte and one of the body's white blood cell types), leaving infected individuals susceptible to other infections. Early in the AIDS epidemic, most HIV-infected people died within ten years of infection. Then, in 1996, antiretroviral therapy (ART) became available, and for people living in affluent countries, HIV/AIDS became a chronic condition. However, ART was expensive, and for people living in developing countries, HIV/AIDS remained a fatal illness. In 2003, HIV was declared a global health emergency, and in 2006, the international community set itself the target of achieving universal access to ART by 2010. By the end of 2010, only 6.6 million of the estimated 15 million people in need of ART in developing countries were receiving ART.

Why Was This Study Done?

One factor that has impeded progress towards universal ART coverage has been the limited availability of trained personnel and laboratory facilities in many developing countries. These resources are needed to determine when individuals should start ART—the World Health Organization currently recommends that people start ART when their CD4 count drops below 350 cells/µl—and to monitor treatment responses over time so that viral resistance to ART is quickly detected. Although a total lymphocyte count can be used as a surrogate measure to decide when to start treatment, repeated CD4 cell counts are the only way to monitor immunologic responses to treatment, a level of monitoring that is rarely sustainable in resource-constrained settings. A method that optimizes resource allocation by prioritizing who gets tested might be one way to improve treatment monitoring. In this study, the researchers applied a new tool for prioritizing laboratory-based CD4 cell count testing in resource-constrained settings to patient data that had been previously collected.

What Did the Researchers Do and Find?

The researchers fitted a mixed-effects statistical model to repeated CD4 count measurements from HIV-infected individuals from seven sites around the world (including some resource-limited sites). They then used model-derived estimates to apply a mathematical tool for predicting—from a CD4 count taken at the start of treatment, and white blood cell counts and lymphocyte percentage measurements taken later—whether CD4 counts would be above 200 cells/µl (the original threshold recommended for ART initiation) and 350 cells/µl (the current recommended threshold) for up to three years after ART initiation. The tool correctly classified 91.5% of the CD4 cell counts that were below 200 cells/µl in the first year of ART. With this threshold, the potential savings in CD4 testing capacity was 54.3%. With a CD4 count threshold of 350 cells/µl, the potential savings in testing capacity was 34%. The results over a three-year follow-up were similar. When applied to six representative HIV-positive individuals, the tool correctly predicted all the CD4 counts above 200 cells/µl, although some individuals who had a predicted CD4 count of less than 200 cells/µl actually had a CD4 count above this threshold. Thus, none of these individuals would have been exposed to an undetected dangerous CD4 count, but the application of the tool would have saved 57% of the CD4 laboratory tests done during the first year of ART.

What Do These Findings Mean?

These findings support the use of this new tool—the prediction-based classification (PBC) algorithm—for predicting a drop in CD4 count below a clinically meaningful threshold in HIV-infected individuals receiving ART. Further studies are now needed to demonstrate the feasibility, clinical effectiveness, and cost-effectiveness of this approach, to find out whether the tool can be used over extended periods of time, and to investigate whether the accuracy of its predictions can be improved by, for example, adding in periodic CD4 testing. Provided these studies confirm its early promise, the researchers suggest that the PBC algorithm could be used as a “triage” tool to direct available laboratory testing capacity to high-priority individuals (those likely to have a dangerously low CD4 count). By optimizing the use of limited laboratory resources in this and other ways, the PBC algorithm could therefore help to maintain and expand ART programs in low- and middle-income countries.

Additional Information

Please access these web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001207.

Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS

NAM/aidsmap provides basic information about HIV/AIDS and summaries of recent research findings on HIV care and treatment

Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including information on HIV/AIDS treatment and care and on universal access to AIDS treatment (in English and Spanish)

The World Health Organization provides information about universal access to AIDS treatment (in several languages)

More information about universal access to HIV treatment, prevention, care, and support is available from UNAIDS

Patient stories about living with HIV/AIDS are available through Avert and through the charity website Healthtalkonline

The site 1 protease, encoded by Mbtps1, mediates the initial cleavage of site 2 protease substrates, including sterol regulatory element binding proteins and CREB/ATF transcription factors. We demonstrate that a hypomorphic mutation of Mbtps1 called woodrat (wrt) caused hypocholesterolemia, as well as progressive hypopigmentation of the coat, that appears to be mechanistically unrelated. Hypopigmentation was rescued by transgenic expression of wild-type Mbtps1, and reciprocal grafting studies showed that normal pigmentation depended upon both cell-intrinsic or paracrine factors, as well as factors that act systemically, both of which are lacking in wrt homozygotes. Mbtps1 exhibited a maternal-zygotic effect characterized by fully penetrant embryonic lethality of maternal-zygotic wrt mutant offspring and partial embryonic lethality (~40%) of zygotic wrt mutant offspring. Mbtps1 is one of two maternal-zygotic effect genes identified in mammals to date. It functions nonredundantly in pigmentation and embryogenesis.

TGF-β is an important paracrine factor in tumorigenesis. Ligand binding of the type I and II TGF-β receptors initiate downstream signaling. The role of stromal TGF-β signaling in prostate cancer progression is unknown. In mice the conditional stromal knockout of the TGF-β receptor type II expression (Tgfbr2fspKO) resulted in the development of prostatic intraepithelial neoplasia and progression to adenocarcinoma within seven months. Clinically, we observed a loss of TGF-β receptor type II expression in 69% of human prostate cancer-associated stroma compared to 15% of stroma associated with benign tissues (n =140, p value < 0.0001). To investigate the mechanism of paracrine TGF-β signaling in prostate cancer progression, we compared the effect of the prostatic stromal cells from Tgfbr2fspKO and Tgfbr2floxE2/floxE2 mice on LNCaP human prostate cancer cells in vitro and tissue recombination xenografts. Induction of LNCaP cell proliferation and tumorigenesis was observed by Tgfbr2fspKO prostate stroma as a result of elevated Wnt3a expression. Neutralizing antibodies to Wnt3a reversed LNCaP tumorigenesis. The TGF-β inhibition of Wnt3a expression was in part through the suppression of Stat3 activity on the Wnt3a promoter. In conclusion, the frequent loss of stromal TβRII expression in human prostate cancer can relieve the paracrine suppression of Wnt3a expression.

Introduction

Yes-associated protein (YAP) is considered an oncogene found amplified in multiple tumors, including head and neck squamous cell carcinoma (HNSCC). However, the role for YAP expression in HNSCC is not understood. Based on the central role of YAP in the hippo pathway, we tested if YAP was associated with the stage of HNSCC progression and metastatic potential.

Methods

To determine the expression of YAP in human benign and HNSCC tissue specimens, immunohistochemical analyses were performed in whole tissue samples and tissue microarrays. The expression of YAP in tissues of microarray was first associated with clinic-pathologic factors and results verified in samples from whole tissue sections. To investigate the role of YAP and p63 in regulating HNSCC epithelial to mesenchymal transition, epithelial and mesenchymal markers were assayed in Fadu and SCC-25 cells, HNSCC cells with endogenously elevated YAP expression and siRNA-mediated expression knockdown.

Results

Analysis of human HNSCC tissues suggested YAP expression was elevated in tumors compared to benign tissues and specifically localized at the tumor invasive front (p value <0.05). But, indexed YAP expression was lower with greater tumor grade (p value  = 0.02). In contrast, p63 expression was primarily elevated in high-grade tumors. Interestingly, both YAP and p63 was strongly expressed at the tumor invasive front and in metastatic HNSCC. Strikingly, we demonstrated YAP expression in the primary HNSCC tumor was associated with nodal metastasis in univariate analysis (p value  = 0.02). However, the knockdown of YAP in Fadu and SCC-25 cell lines was not associated with changes in epithelial to mesenchymal transdifferentiation or p63 expression.

Conclusion

Together, YAP expression, in combination with p63 can facilitate identification of HNSCC tumors from hyperplastic and benign tissues and the metastatic function of YAP in HNSCC may not be a result of epithelia to mesenchymal transdifferentiation.

Neoplastic progression is an evolutionary process driven by the generation of clonal diversity and natural selection on that diversity within a neoplasm. We hypothesized that clonal diversity is associated with the risk of progression to cancer. We obtained molecular data from a cohort of 239 participants with Barrett’s esophagus (BE), including microsatellite shifts and loss of heterozygosity, DNA content tetraploidy and aneuploidy, methylation and sequence mutations. Using these data, we tested all major diversity measurement methods, including genetic divergence and entropy based measures, to determine which measures are correlated with risk of progression to esophageal adenocarcinoma. We also tested whether the use of different sets of loci and alterations to define clones (e.g. selectively advantageous vs. evolutionarily neutral) improved the predictive value of the diversity indices. All diversity measures were strong and highly significant predictors of progression (Cox proportional hazards model, p<0.001). The type of alterations evaluated had little effect on the predictive value of most of the diversity measures. In summary, diversity measures are robust predictors of progression to cancer in this cohort.

Objectives

Bipolar disorder is a debilitating psychiatric illness presenting with recurrent mania and depression. The pathophysiology of bipolar disorder is poorly understood, and molecular targets in the treatment of bipolar disorder remain to be identified. Preclinical studies have suggested that glycogen synthase kinase-3 (GSK3) is a potential therapeutic target in bipolar disorder, but evidence of abnormal GSK3 in human bipolar disorder and its response to treatment is still lacking.

Methods

This study was conducted in acutely ill type I bipolar disorder subjects who were hospitalized for a manic episode. The protein level and the inhibitory serine phosphorylation of GSK3 in peripheral blood mononuclear cells of bipolar manic and healthy control subjects were compared, and the response of GSK3 to antimanic treatment was evaluated.

Results

The levels of GSK3α and GSK3β in this group of bipolar manic subjects were higher than healthy controls. Symptom improvement during an eight-week antimanic treatment with lithium, valproate, and atypical antipsychotics was accompanied by a significant increase in the inhibitory serine phosphorylation of GSK3, but not the total level of GSK3, whereas concomitant electroconvulsive therapy treatment during a manic episode appeared to dampen the response of GSK3 to pharmacological treatment.

Conclusions

Results of this study suggest that GSK3 can be modified during the treatment of bipolar mania. This finding in human bipolar disorder is in agreement with preclinical data suggesting that inhibition of GSK3 by increasing serine phosphorylation is a response of GSK3 to psychotropics used in bipolar disorder, supporting the notion that GSK3 is a promising molecular target in the pharmacological treatment of bipolar disorder.

Autism is a neurodevelopmental disorder characterized by problems in communication, social skills, and repetitive behavior. Recent studies suggest that apoptotic and inflammatory mechanisms may contribute to the pathogenesis of this disorder. Nuclear factor-κB (NF-κB) is an important gene transcriptional factor involved in the mediation of inflammation and apoptosis. This study examined the activities of the NF-κB signaling pathway in the brain of autistic subjects and their age-matched controls. The NF-κB activation is also determined in the brain of BTBR mice, which is a promising animal model for study of pathogenic mechanisms responsible for autism. Our results showed that the level of IKKα kinase, which phosphorylates the inhibitory subunit IκBα, is significantly increased in the cerebellum of autistic subjects. However, the expression and phosphorylation of IκBα are not altered. In addition, our results demonstrated that the expression of NF-κB (p65), and the phosphorylation/activation of NF-κB (p65) at Ser536 are not significantly changed in the cerebellum and cortex of both autistic subjects and BTBR mice. Our findings suggest that the NF-κB signaling pathway is not disregulated in the brain of autistic subjects and thus may not be significantly involved in the processes of abnormal inflammatory responses suggested in autistic brain.