Uncovering Flat and Hierarchical Topics by Community Discovery on Word Co-occurrence Network

Topic modeling aims to discover latent themes in collections of text documents. It has various applications across fields such as sociology, opinion analysis, and media studies. In such areas, it is essential to have easily interpretable, diverse, and coherent topics. An efficient topic modeling technique should accurately identify flat and hierarchical topics, especially useful in disciplines where topics can be logically arranged into a tree format. In this paper, we propose Community Topic, a novel algorithm that exploits word co-occurrence networks to mine communities and produces topics. We also evaluate the proposed approach using several metrics and compare it with usual baselines, confirming its good performances. Community Topic enables quick identification of flat topics and topic hierarchy, facilitating the on-demand exploration of sub- and super-topics. It also obtains good results on datasets in different languages.

Actigraphy methodology in the Kids Mod PAH trial: Physical activity as a functional endpoint in pediatric clinical trials

Pulmonary vasodilator treatment can improve hemodynamics, right ventricular function, symptoms, and survival in pediatric pulmonary hypertension (PH). However, clinical trial data are lacking due to many constraints. One major limitation is the lack of relevant trial endpoints reflective of hemodynamics or functional status in patients in whom standard exercise testing is impractical, unreliable, or not reproducible. The Kids Mod PAH trial (Mono- vs. Duo Therapy for Pediatric Pulmonary Arterial Hypertension) is an ongoing multicenter, Phase III, randomized, open-label, pragmatic trial to compare the safety and efficacy of first-line combination therapy (sildenafil and bosentan) to first-line monotherapy (sildenafil alone) in 100 pediatric patients with PH across North America. Investigators will measure participants' physical activity with a research-grade, wrist-worn actigraphy device at multiple time points as an exploratory secondary outcome. Vector magnitude counts per minute and activity intensity will be compared between the treatment arms. By directly and noninvasively measuring physical activity in the ambulatory setting, we aim to identify a novel, simple, inexpensive, and highly reproducible approach for quantitative assessment of exercise tolerance in pediatric PH. These data will increase the field's understanding of the effect of pulmonary vasodilator treatment on daily activity - a quantitative measure of functional status and wellbeing in pediatric PH and a potential primary outcome for future clinical trials in children with cardiopulmonary disorders.

Measurement of Physical Activity by Actigraphy in Infants and Young Children with Pulmonary Arterial Hypertension

OBJECTIVE

To evaluate the feasibility, tolerability, and adherence with wearable actigraphy devices among infants and children with pulmonary arterial hypertension (PAH).

STUDY DESIGN

This multicenter, prospective, observational study included children ages 0-6 years with and without PAH. Participants wore the ActiGraph wGT3X-BT on the hip and FitBit Inspire on the wrist during waking hours for 14 days. Steps, vector magnitude counts per minute, activity intensity, heart rate, and heart rate variability were compared between groups.

RESULTS

Forty-seven participants (18 PAH, 29 control) were enrolled from 10 North American sites. PAH patients were mostly functional class II (n = 16, 89%) and treated with oral medications at the time of enrollment. The number of wear days was not significantly different between the groups (ActiGraph: 10 [95% CI: 5.5, 12.2] in PAH vs 8 [4, 12] in control, P = .20; FitBit 13 [10, 13.8] in PAH vs 12 [8, 14] in control, P = .87). Complete data were obtained in 81% of eligible ActiGraph participants and 72% of FitBit participants. PAH participants demonstrated fewer steps, lower vector magnitude counts per minute, more sedentary activity, and less intense physical activity at all levels compared with control participants. No statistically significant differences in heart rate variability were demonstrated between the 2 groups.

CONCLUSIONS

Measurement of physical activity and other end points using wearable actigraphy devices was feasible in young children with PAH. Larger studies should determine associations between physical activity and disease severity in young patients with PAH to identify relevant end points for pediatric clinical trials.

Predictors of Dairy Worker Pre-Test and Post-Test Performance on a Dairy Safety Knowledge Test: Impact of Education Level and Native Language

BACKGROUND

Efficacy-driven assessments of linguistically appropriate occupational health and safety training (OHS) for dairy workers remain uncommon. This study analyzes predictors of performance on a dairy safety knowledge test using pre-and-post knowledge assessments. The safety training course was delivered by iPad™ to Idahoan dairy workers, managers, and owners.

OBJECTIVE

To determine the predictors of safety knowledge scores among dairy worker course participants.

METHODS

Predictors of pre-test (baseline) scores and change in test scores of n = 1,336 participants were compared, and multivariate iterative linear regressions were used to predict test performance, adjusting for variables such as occupation, years of formal education, native language, and years in dairy work.

RESULTS

Test scores for Spanish and English speakers improved between pre-test and post-test. Years of formal education was the most predictive variable of higher baseline scores and change in test scores among dairy safety course participants, regardless of language.

CONCLUSION

Dairy worker safety training course results showed improvements in safety knowledge and test scores. Years of formal education of participants appears to be a key determinant of increases in safety knowledge, and therefore safety training programs need to address the learning needs of less educated workers.

The scope for adaptive capacity in emergency departments: modelling performance constraints using control task analysis and social organisational cooperation analysis

Patient flow between the emergency department (ED) and hospital wards becomes problematic when bed availability is limited. To better understand the constraints that shape patient flow and everyday work in the ED, we applied Control Task Analysis (i.e. Contextual Activities Template, CAT) and Social Organisational Cooperation Analysis (SOCA) phases from the Cognitive Work Analysis framework to identify ways in which to optimise patient flow. The model and analysis were created through observations in the ED of clinicians (e.g. nurses, doctors), and professional staff (e.g. ward personnel, clerks). The CAT and SOCA-CAT models illustrate workspaces, patient journey phases, and patient volume within the department that are heavily loaded with tasks and human and non-human agents performing these tasks, while others are underutilised. The findings suggest that an ED's adaptive capacity could be strengthened through the integration of additional human and non-human agents allowing the redistribution of clinical and non-clinical tasks. Practitioner Summary: Workflow in EDs is constrained by uneven geographical distribution of activities, insufficient adaptive support during critical patient journey phases and periods of high patient volume. Adaptive capacity could be strengthened by additional human and non-human agents in combination with a redistribution of tasks, supporting seamless successful structural and behavioural adaptation in ED.

Disability glare and nighttime driving performance among commercial drivers in Ghana

OBJECTIVE

Glare caused by the headlights of on-coming vehicles risk safe driving at night. The study aimed to determine the relationship between glare exposure and nighttime driving performance among commercial drivers in Ghana.

METHODS

This cross-sectional study involved commercial drivers with complaints of nighttime driving difficulties (N = 80; mean age = 41.5 ± 11.1 years). A questionnaire was used to investigate nighttime driving performance following glare exposure. We measured contrast sensitivity and visual acuity under photopic conditions. With an experimental setup in a mesopic setting, we measured visual acuity with and without glare exposure. The difference between the two mesopic visual acuities was quantified as disability glare index. With the same setup, photostress recovery time was also measured. Regression analyses were used to determine the relationship between nighttime driving performance score and the measures taken in both photopic and mesopic settings.

RESULTS

The average nighttime driving performance score was 47.8 ± 17.5. Driving performance was negatively correlated with all variables (R = -0.87 to -0.30, all p < .01), except contrast sensitivity (R = 0.74, p < .01). A multiple linear regression showed that the model with all variables explained 83.8% of the variance, but only disability glare index was a significant predictor of nighttime driving performance following glare exposure (standardized B = -0.61, p < .01).

CONCLUSION

Our results show that the change in mesopic visual acuities following glare can predict nighttime driving performance. This measure can be incorporated into the assessment of driving fitness by licensing departments to evaluate whether a person can drive safely at night amidst glare exposure.

Non-invasive imaging reveals conditions that impact distribution and persistence of cells after in vivo administration

Background

Cell-based regenerative medicine therapies are now frequently tested in clinical trials. In many conditions, cell therapies are administered systemically, but there is little understanding of their fate, and adverse events are often under-reported. Currently, it is only possible to assess safety and fate of cell therapies in preclinical studies, specifically by monitoring animals longitudinally using multi-modal imaging approaches. Here, using a suite of in vivo imaging modalities to explore the fate of a range of human and murine cells, we investigate how route of administration, cell type and host immune status affect the fate of administered cells.

Methods

We applied a unique imaging platform combining bioluminescence, optoacoustic and magnetic resonance imaging modalities to assess the safety of different human and murine cell types by following their biodistribution and persistence in mice following administration into the venous or arterial system.

Results

Longitudinal imaging analyses (i) suggested that the intra-arterial route may be more hazardous than intravenous administration for certain cell types, (ii) revealed that the potential of a mouse mesenchymal stem/stromal cell (MSC) line to form tumours depended on administration route and mouse strain and (iii) indicated that clinically tested human umbilical cord (hUC)-derived MSCs can transiently and unexpectedly proliferate when administered intravenously to mice.

Conclusions

In order to perform an adequate safety assessment of potential cell-based therapies, a thorough understanding of cell biodistribution and fate post administration is required. The non-invasive imaging platform used here can expose not only the general organ distribution of these therapies, but also a detailed view of their presence within different organs and, importantly, tumourigenic potential. Our observation that the hUC-MSCs but not the human bone marrow (hBM)-derived MSCs persisted for a period in some animals suggests that therapies with these cells should proceed with caution.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1076-x) contains supplementary material, which is available to authorized users.

Yield and Viability of Human Limbal Stem Cells From Fresh and Stored Tissue

PURPOSE

We compared cell number, putative stem cell markers, and clonogenic ability in fresh uncultured human limbal epithelial cells to that obtained from stored organ-cultured tissue.

METHODS

Cell suspensions were formed from fresh and organ culture-stored human limbal epithelium. Expression of putative stem cell markers ΔNp63 and TrkA was performed using immunofluorescent staining before culture. Colony-forming efficiency (CFE) assays were performed at first passage. The effects of tissue storage, age, and postmortem/culture times were analyzed in a general linear model.

RESULTS

Limbal tissue from 94 donors (34 fresh and 60 stored) was compared. Three times more cells were obtained per eye from fresh (35.34 × 104; SD, 17.39) than stored (11.24 × 104; SD, 11.57; P < 0.01) tissue. A higher proportion of cells from fresh tissue were viable (91.9%; SD, 5.7 vs. 85%; SD, 10.8) P < 0.01. Higher total cell expression of ΔNp63 (20.19 × 104; SD, 15.5 vs. 3.28 104; SD, 4.33) and TrkA (59.24 × 104; SD, 13.21 vs. 7.65 × 104; SD, 1.05) was observed in fresh than stored tissue (P < 0.01). Colony-forming efficiency was higher for fresh (1.42; SD, 0.12) than stored (0.43; SD, 0.15; P < 0.01) cells. For stored tissue only, there was a significant inverse relationship between donor age and total number of cells isolated (R2 = 0.27, P < 0.001).

CONCLUSIONS

Storage of corneoscleral discs in organ culture medium leads to significant reduction in limbal epithelial cell number, expression of ΔNp63 and TrkA, and viability compared to fresh tissue. There is a smaller basal stem cell population in stored compared to fresh tissue.

Repair of Torn Avascular Meniscal Cartilage Using Undifferentiated Autologous Mesenchymal Stem Cells: From In Vitro Optimization to a First-in-Human Study

Meniscal cartilage tears are common and predispose to osteoarthritis (OA). Most occur in the avascular portion of the meniscus where current repair techniques usually fail. We described previously the use of undifferentiated autologous mesenchymal stem cells (MSCs) seeded onto a collagen scaffold (MSC/collagen‐scaffold) to integrate meniscal tissues in vitro. Our objective was to translate this method into a cell therapy for patients with torn meniscus, with the long‐term goal of delaying or preventing the onset of OA. After in vitro optimization, we tested an ovine‐MSC/collagen‐scaffold in a sheep meniscal cartilage tear model with promising results after 13 weeks, although repair was not sustained over 6 months. We then conducted a single center, prospective, open‐label first‐in‐human safety study of patients with an avascular meniscal tear. Autologous MSCs were isolated from an iliac crest bone marrow biopsy, expanded and seeded into the collagen scaffold. The resulting human‐MSC/collagen‐scaffold implant was placed into the meniscal tear prior to repair with vertical mattress sutures and the patients were followed for 2 years. Five patients were treated and there was significant clinical improvement on repeated measures analysis. Three were asymptomatic at 24 months with no magnetic resonance imaging evidence of recurrent tear and clinical improvement in knee function scores. Two required subsequent meniscectomy due to retear or nonhealing of the meniscal tear at approximately 15 months after implantation. No other adverse events occurred. We conclude that undifferentiated MSCs could provide a safe way to augment avascular meniscal repair in some patients. Registration: EU Clinical Trials Register, 2010‐024162‐22. Stem Cells Translational Medicine2017;6:1237–1248

Bone Marrow-derived Cells Contribute to the Pathogenesis of Pulmonary Arterial Hypertension

RATIONALE

Pulmonary arterial hypertension (PAH) is a progressive lung disease of the pulmonary microvasculature. Studies suggest that bone marrow (BM)-derived circulating cells may play an important role in its pathogenesis.

OBJECTIVES

We used a genetic model of PAH, the Bmpr2 mutant mouse, to study the role of BM-derived circulating cells in its pathogenesis.

METHODS

Recipient mice, either Bmpr2(R899X) mutant or controls, were lethally irradiated and transplanted with either control or Bmpr2(R899X) BM cells. Donor cells were traced in female recipient mice by Y chromosome painting. Molecular and function insights were provided by expression and cytokine arrays combined with flow cytometry, colony-forming assays, and competitive transplant assays.

MEASUREMENTS AND MAIN RESULTS

We found that mutant BM cells caused PAH with remodeling and inflammation when transplanted into control mice, whereas control BM cells had a protective effect against the development of disease, when transplanted into mutant mice. Donor BM-derived cells were present in the lungs of recipient mice. Functional and molecular analysis identified mutant BM cell dysfunction suggestive of a PAH phenotype soon after activation of the transgene and long before the development of lung pathology.

CONCLUSIONS

Our data show that BM cells played a key role in PAH pathogenesis and that the transplanted BM cells were able to drive the lung phenotype in a myeloablative transplant model. Furthermore, the specific cell types involved were derived from hematopoietic stem cells and exhibit dysfunction long before the development of lung pathology.

De novo deletions and duplications of 17q25.3 cause susceptibility to cardiovascular malformations

Background

Genomic disorders resulting from deletion or duplication of genomic segments are known to be an important cause of cardiovascular malformations (CVMs). In our previous study, we identified a unique individual with a de novo 17q25.3 deletion from a study of 714 individuals with CVM.

Methods

To understand the contribution of this locus to cardiac malformations, we reviewed the data on 60,000 samples submitted for array comparative genomic hybridization (CGH) studies to Medical Genetics Laboratories at Baylor College of Medicine, and ascertained seven individuals with segmental aneusomy of 17q25. We validated our findings by studying another individual with a de novo submicroscopic deletion of this region from Cytogenetics Laboratory at Cincinnati Children’s Hospital. Using bioinformatic analyses including protein-protein interaction network, human tissue expression patterns, haploinsufficiency scores, and other annotation systems, including a training set of 251 genes known to be linked to human cardiac disease, we constructed a pathogenicity score for cardiac phenotype for each of the 57 genes within the terminal 2.0 Mb of 17q25.3.

Results

We found relatively high penetrance of cardiovascular defects (~60 %) with five deletions and three duplications, observed in eight unrelated individuals. Distinct cardiac phenotypes were present in four of these subjects with non-recurrent de novo deletions (range 0.08 Mb–1.4 Mb) in the subtelomeric region of 17q25.3. These included coarctation of the aorta (CoA), total anomalous pulmonary venous return (TAPVR), ventricular septal defect (VSD) and atrial septal defect (ASD). Amongst the three individuals with variable size duplications of this region, one had patent ductus arteriosus (PDA) at 8 months of age.

Conclusion

The distinct cardiac lesions observed in the affected patients and the bioinformatics analyses suggest that multiple genes may be plausible drivers of the cardiac phenotype within this gene-rich critical interval of 17q25.3.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-015-0291-0) contains supplementary material, which is available to authorized users.

ABCG2pos lung mesenchymal stem cells are a novel pericyte subpopulation that contributes to fibrotic remodeling

Genesis of myofibroblasts is obligatory for the development of pathology in many adult lung diseases. Adult lung tissue contains a population of perivascular ABCG2(pos) mesenchymal stem cells (MSC) that are precursors of myofibroblasts and distinct from NG2 pericytes. We hypothesized that these MSC participate in deleterious remodeling associated with pulmonary fibrosis (PF) and associated hypertension (PH). To test this hypothesis, resident lung MSC were quantified in lung samples from control subjects and PF patients. ABCG2(pos) cell numbers were decreased in human PF and interstitial lung disease compared with control samples. Genetic labeling of lung MSC in mice enabled determination of terminal lineage and localization of ABCG2 cells following intratracheal administration of bleomycin to elicit fibrotic lung injury. Fourteen days following bleomycin injury enhanced green fluorescent protein (eGFP)-labeled lung MSC-derived cells were increased in number and localized to interstitial areas of fibrotic and microvessel remodeling. Finally, gene expression analysis was evaluated to define the response of MSC to bleomycin injury in vivo using ABCG2(pos) MSC isolated during the inflammatory phase postinjury and in vitro bleomycin or transforming growth factor-β1 (TGF-β1)-treated cells. MSC responded to bleomycin treatment in vivo with a profibrotic gene program that was not recapitulated in vitro with bleomycin treatment. However, TGF-β1 treatment induced the appearance of a profibrotic myofibroblast phenotype in vitro. Additionally, when exposed to the profibrotic stimulus, TGF-β1, ABCG2, and NG2 pericytes demonstrated distinct responses. Our data highlight ABCG2(pos) lung MSC as a novel cell population that contributes to detrimental myofibroblast-mediated remodeling during PF.

Rescuing the BMPR2 signaling axis in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a lethal disorder characterized by pulmonary arterial remodeling, increased right ventricular systolic pressure (RVSP), vasoconstriction and inflammation. The heritable form of PAH (HPAH) is usually (>80%) caused by mutations in the bone morphogenic protein receptor 2 (BMPR2) gene. Existing treatments for PAH typically focus on the end-stage sequelae of the disease, but do not address underlying mechanisms of vascular obstruction and blood flow and thus, in the long run, have limited effect because they treat the symptoms rather than the cause. Over the past decade, improved understanding of the molecular mechanisms behind the disease has enabled us to consider several novel therapeutic pathways. These include approaches directed toward BMPR2 gene expression, alternative splicing, downstream BMP signaling, metabolic pathways and the role of estrogens and estrogenic compounds in BMP signaling. It is likely that, ultimately, only one or two of these pathways will generate meaningful treatment options, however the potential benefits to PAH patients are still likely to be significant.

Definition and application of good manufacturing process-compliant production of CEA-specific chimeric antigen receptor expressing T-cells for phase I/II clinical trial

Adoptive cell therapy employing gene-modified T-cells expressing chimeric antigen receptors (CARs) has shown promising preclinical activity in a range of model systems and is now being tested in the clinical setting. The manufacture of CAR T-cells requires compliance with national and European regulations for the production of medicinal products. We established such a compliant process to produce T-cells armed with a first-generation CAR specific for carcinoembryonic antigen (CEA). CAR T-cells were successfully generated for 14 patients with advanced CEA(+) malignancy. Of note, in the majority of patients, the defined procedure generated predominantly CD4(+) CAR T-cells with the general T-cell population bearing an effector-memory phenotype and high in vitro effector function. Thus, improving the process to generate less-differentiated T-cells would be more desirable in the future for effective adoptive gene-modified T-cell therapy. However, these results confirm that CAR T-cells can be generated in a manner compliant with regulations governing medicinal products in the European Union.

Interaction between bone morphogenetic protein receptor type 2 and estrogenic compounds in pulmonary arterial hypertension

Abstract The majority of heritable pulmonary arterial hypertension (HPAH) cases are associated with mutations in bone morphogenetic protein receptor type 2 (BMPR2). BMPR2 mutation carries about a 20% lifetime risk of PAH development, but penetrance is approximately three times higher in females. Previous studies have shown a correlation between estrogen metabolism and penetrance, with increased levels of the estrogen metabolite 16α-hydroxyestrone (16αOHE) and reduced levels of the metabolite 2-methoxyestrogen (2ME) associated with increased risk of disease. The goal of this study was to determine whether 16αOHE increased and 2ME decreased penetrance of disease in Bmpr2 mutant mice and, if so, by what mechanism. We found that 16αOHE∶2ME ratio was high in male human HPAH patients. Bmpr2 mutant male mice receiving chronic 16αOHE had doubled disease penetrance, associated with reduced cardiac output. 2ME did not have a significant protective effect, either alone or in combination with 16αOHE. In control mice but not in Bmpr2 mutant mice, 16αOHE suppressed bone morphogenetic protein signaling, probably directly through suppression of Bmpr2 protein. Bmpr2 mutant pulmonary microvascular endothelial cells were insensitive to estrogen signaling through canonical pathways, associated with aberrant intracellular localization of estrogen receptor α. In both control and Bmpr2 mutant mice, 16αOHE was associated with suppression of cytokine expression but with increased alternate markers of injury, including alterations in genes related to thrombotic function, angiogenesis, planar polarity, and metabolism. These data support a causal relationship between increased 16αOHE and increased PAH penetrance, with the likely molecular mechanisms including suppression of BMPR2, alterations in estrogen receptor translocation, and induction of vascular injury and insulin resistance-related pathways.

Outcomes of congenital diaphragmatic hernia in the modern era of management

OBJECTIVE

To identify clinical factors associated with pulmonary hypertension (PH) and mortality in patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

A prospective cohort of neonates with a diaphragm defect identified at 1 of 7 collaborating medical centers was studied. Echocardiograms were performed at 1 month and 3 months of age and analyzed at a central core by 2 cardiologists independently. Degree of PH and survival were tested for association with clinical variables using Fischer exact test, χ(2), and regression analysis.

RESULTS

Two hundred twenty patients met inclusion criteria. Worse PH measured at 1 month of life was associated with higher mortality. Other factors associated with mortality were need for extracorporeal membrane oxygenation, patients inborn at the treating center, and patients with a prenatal diagnosis of CDH. Interestingly, patients with right sided CDH did not have worse outcomes.

CONCLUSIONS

Severity of PH is associated with mortality in CDH. Other factors associated with mortality were birth weight, gestational age at birth, inborn status, and need for extracorporeal membrane oxygenation.

Role of BMPR2 alternative splicing in heritable pulmonary arterial hypertension penetrance

BACKGROUND

Bone morphogenic protein receptor 2 (BMPR2) gene mutations are the most common cause of heritable pulmonary arterial hypertension. However, only 20% of mutation carriers get clinical disease. Here, we explored the hypothesis that this reduced penetrance is due in part to an alteration in BMPR2 alternative splicing.

METHODS AND RESULTS

Our data showed that BMPR2 has multiple alternative spliced variants. Two of these, isoform-A (full length) and isoform-B (missing exon 12), were expressed in all tissues analyzed. Analysis of cultured lymphocytes of 47 BMPR2 mutation-positive heritable pulmonary arterial hypertension patients and 35 BMPR2 mutation-positive unaffected carriers showed that patients had higher levels of isoform-B compared with isoform-A (B/A ratio) than carriers (P=0.002). Furthermore, compared with cells with a low B/A ratio, cells with a high B/A ratio had lower levels of unphosphorylated cofilin after BMP stimulation. Analysis of exon 12 sequences identified an exonic splice enhancer that binds serine arginine splicing factor 2 (SRSF2). Because SRSF2 promotes exon inclusion, reduced SRSF2 expression would mean that exon 12 would not be included in final BMPR2 mRNA (thus promoting increased isoform-B formation). Western blot analysis showed that SRSF2 expression was lower in cells from patients compared with cells from carriers and that siRNA-mediated knockdown of SRSF2 in pulmonary microvascular endothelial cells resulted in elevated levels of isoform-B compared with isoform-A, ie, an elevated B/A ratio.

CONCLUSIONS

Alterations in BMPR2 isoform ratios may provide an explanation of the reduced penetrance among BMPR2 mutation carriers. This ratio is controlled by an exonic splice enhancer in exon 12 and its associated splicing factor, SRSF2.

Connectivity map analysis of nonsense-mediated decay-positive BMPR2-related hereditary pulmonary arterial hypertension provides insights into disease penetrance

The molecular mechanisms underlying the reduced penetrance seen in the nonsense-mediated decay-positive (NMD+) BMPR2 mutation-associated hereditary pulmonary arterial hypertension (HPAH) remain unknown. We reasoned that the cellular and genetic mechanisms behind this phenomenon could be uncovered by combining expression profiling with Connectivity Map (cMap) analysis. Cultured lymphocytes from 10 patients with HPAH and 10 matched familial control subjects, all with NMD+ BMPR2 mutations, were subjected to expression analysis. For each group, the expression data were combined before analysis. This generated a signature of 23 up-regulated and 12 down-regulated genes in patients with HPAH compared with control subjects (the "PAH penetrance signature"). Although gene set enrichment analysis of this signature was not uniquely informative, cMap analysis identified drugs with expression signatures similar to the PAH penetrance signature. Several of these drugs were predicted to influence reactive oxygen species (ROS) formation. This hypothesis was tested and confirmed in the same cells initially subjected to the expression analysis using quantitative biochemical detection of ROS concentration. We conclude that expression of the PAH penetrance signature represents an increased risk of developing clinical HPAH and that ROS formation may play a role in pathogenesis of HPAH. These results provide the first molecular insights into NMD+ BMPR2 related HPAH penetrance and highlight the potential utility of cMap analyses in pulmonary research.

Oxidative injury is a common consequence of BMPR2 mutations

Hereditary pulmonary arterial hypertension (PAH) is usually caused by mutations in BMPR2. Mutations are found throughout the gene, and common molecular consequences of different types of mutation are not known. Knowledge of common molecular consequences would provide insight into the molecular etiology of the disease. The objective of this study was to determine the common molecular consequences across classes of BMPR2 mutation. Increased superoxide and peroxide production and alterations in genes associated with oxidative stress were a common consequence of stable transfection of the vascular smooth muscle cells, with three distinct classes of BMPR2 mutation, in the ligand binding domain, the kinase domain and the cytoplasmic tail domain. Measurement of oxidized lipids in whole lung from transgenic mice expressing a mutation in the BMPR2 cytoplasmic tail showed a 50% increase in isoprostanes and a two-fold increase in isofurans, suggesting increased reactive oxygen species (ROS) of mitochondrial origin. Immunohistochemistry on BMPR2 transgenic mouse lung showed that oxidative stress was vascular-specific. Electron microscopy showed decreased mitochondrial size and variability in the pulmonary vessels from BMPR2-mutant mice. Measurement of oxidized lipids in urine from humans with BMPR2 mutations demonstrated increased ROS, regardless of disease status. Immunohistochemistry on hereditary PAH patient lung confirmed oxidative stress specific to the vasculature. Increased oxidative stress, likely of mitochondrial origin, is a common consequence of BMPR2 mutation across mutation types in cell culture, mice and humans.

Transcripts from a novel BMPR2 termination mutation escape nonsense mediated decay by downstream translation re-initiation: implications for treating pulmonary hypertension

Bone morphogenetic protein receptor type 2 (BMPR2) gene mutations are a major risk factor for heritable pulmonary arterial hypertension (HPAH), an autosomal dominant fatal disease. We have previously shown that BMPR2 transcripts that contain premature termination codon (PTC) mutations are rapidly and nearly completely degraded through nonsense mediated decay (NMD). Here we report a unique PTC mutation (W13X) that did not behave in the predicted manner. We found that patient-derived cultured lymphocytes (CLs) contained readily detectable levels of the PTC-containing transcript. Further analysis suggested that this transcript escaped NMD by translational re-initiation at a downstream Kozak sequence, resulting in the omission of 173 amino acids. Treatment of CLs containing the PTC with an aminoglycoside decreased the truncated protein levels, with a reciprocal increase in full-length BMPR2 protein and, importantly, BMPR-II signaling. This is the first demonstration of aminoglycoside-mediated 'repair' of a BMPR2 mutation at the protein level in patient-derived cells and has obvious implications for treatment of HPAH where no disease-specific treatment options are available. Our data also suggest the need for a more thorough characterization of mutations prior to labeling them as haploinsufficient or dominant negative based simply on sequencing data.

Penetrance of pulmonary arterial hypertension is modulated by the expression of normal BMPR2 allele

Familial pulmonary arterial hypertension (FPAH) is a progressive, fatal disease caused by mutations in the bone morphogenetic protein receptor type 2 gene (BMPR2). FPAH is inherited as an autosomal dominant trait, and shows incomplete penetrance in that many with BMPR2 mutations do not develop FPAH, suggesting a role for, as yet unidentified, modifier genes in disease penetrance. We hypothesized that variable levels of expression of the wild-type (WT) BMPR2 allele could act as a modifier and influence penetrance of FPAH. WT BMPR2 levels were determined by real-time PCR analysis in lymphoblastoid (LB) cell lines derived from normal controls and individuals with FPAH. The FPAH kindreds analyzed carried mutations that result in the activation of nonsense-mediated decay (NMD) pathway, which leads to the degradation of the mutant RNA, thus ensuring that only the WT BMPR2 transcripts will be detected in the real-time assay. Our data show that WT and mutant BMPR2 levels can be reproducibly measured in patient-derived LB cell lines, and that unaffected mutation carrier-derived LB cell lines have higher levels of WT BMPR2 transcripts than FPAH patient-derived LB cell lines (p<or=0.005). Our findings suggest that the levels of expression of WT BMPR2 allele transcripts is important in the pathogenesis of FPAH caused by NMD(+) mutations. Furthermore, our study illustrates a novel application of lymphoblastoid cell lines in the study of PAH, especially important because the affected site, that is, the lung, is not available for unaffected mutation carriers.

Cryopreservation of hematopoietic stem/progenitor cells for therapeutic use

To date, more than 25,000 hematopoietic transplants have been carried out across Europe for hematological disorders, the majority being for hematological malignancies. At least 70% of these are autologous transplants, the remaining 30% being allogeneic, which are sourced from related (70% of the allogeneic) or unrelated donors. Peripheral blood mobilized with granulocyte colony stimulating factor is the major source of stem cells for transplantation, being used in approx 95% of autologous transplants and in approx 65% of allogeneic transplants. Other cell sources used for transplantation are bone marrow and umbilical cord blood. One crucial advance in the treatment of these disorders has been the development of the ability to cryopreserve hematopoietic stem cells for future transplantation. For bone marrow and mobilized peripheral blood, the majority of cryopreserved harvests come from autologous collections that are stored prior to a planned infusion following further treatment of the patient or at the time of a subsequent relapse. Other autologous harvests are stored as backup or "rainy day" harvests, the former specifically being intended to rescue patients who develop graft failure following an allogeneic transplant or who may require this transplant at a later date. Allogeneic bone marrow and mobilized peripheral blood are less often cryopreserved than autologous harvests. This is in contrast to umbilical cord blood that may be banked for directed or sibling (related) hematopoietic stem cell transplants, for allogeneic unrelated donations, and for autologous donations. Allogeneic unrelated donations are of particular use for providing a source of hematopoietic stem cells for ethnic minorities, patients with rare human leukocyte antigen types, or where the patient urgently requires a transplant and cannot wait for the weeks to months required to prepare a bone marrow donor. There are currently more than 200,000 banked umbilical cord blood units registered with the Bone Marrow Donors Worldwide registry. In this chapter, we describe several protocols that we have used to cryopreserve these different sources of hematopoietic stem/progenitor cells, keeping in mind that the protocols may vary among transplant processing centers.

Allergic contact dermatitis to proparacaine with subsequent cross-sensitization to tetracaine from ophthalmic preparations

We report 2 cases of allergic contact dermatitis (ACD) to proparacaine and tetracaine. Patient 1 is an ophthalmologist with chronic finger pad dermatitis sensitized to the topical anesthetic proparacaine. Despite discontinuance of proparacaine and substitution with a patch test negative agent, tetracaine, his hand dermatitis persisted. Follow up patch testing documented that acquisition of contact allergy to tetracaine as well as thiuram had taken place. Patient 2 had a periocular eczematous dermatitis with ACD to both proparacaine and tetracaine. Cross sensitization between related topical ophthalmologic anesthetics has been suggested to be a rare occurrence. We suggest that allergic sensitization and possible cross-reaction to topical anesthetics in ophthalmologists and ophthalmologic technicians is an occupational hazard. Chronically eczematized skin might result in increased exposure to contact allergens and result in concomitant allergic sensitization. ACD to topical anesthetic agents among ophthalmologists should be recognized as a potential hazard.

Use of the new IntraStent for treatment of transverse arch hypoplasia/coarctation of the aorta

We report the use of a new biliary stent (IntraStent Double Strut LD) adapted for use in a 16-year-old young man with moderate-severe transverse arch hypoplasia/coarctation of the aorta following two surgical attempts at correction/relief of the coarctation. The stent implantation procedure resulted in complete relief of the coarctation.

Transcatheter closure of large persistent left superior vena cava causing cyanosis in two patients post-Fontan operation utilizing the Gianturco Grifka vascular occlusion device

We report the successful transcatheter closure of a large persistent left superior vena cava draining into the pulmonary venous circulation causing cyanosis in two patients who had previously undergone the Fontan operation utilizing the Gianturco Grifka vascular occlusion device. Cathet Cardiovasc Intervent 2001;53:398-404.

Historical perspective of turnover of dominant follicles during the bovine estrous cycle: key concepts, studies, advancements, and terms

This review chronicles the key concepts, studies, advancements and terms that have led to our current understanding of turnover of dominant follicles (growth and atresia) during the bovine estrous cycle. The "two-wave" concept of follicular development was first proposed in 1960, but remained controversial for the next 28 yr. The concept of the "dominant" follicle was adapted to cattle in 1987. By 1988, ultrasound analysis of individual follicles had demonstrated that heifers usually had two or three distinct waves of turnover of dominant follicles during an estrous cycle. From 1992 to 1993, it was established that a transient rise in serum concentrations of FSH initiated each follicular wave, and a decreased episodic secretion of LH was associated with loss of dominance and the end of a nonovulatory follicular wave. In the past decade, numerous intrafollicular growth factors, such as inhibins, activins, and insulin-like growth factors and their binding proteins, have been identified in follicular fluid of individual bovine follicles. In addition, in vitro studies demonstrate that these growth factors could have endocrine, autocrine, or paracrine actions that modify gonadotropin-stimulated follicular growth and differentiation. However, the precise role of intrafollicular growth factors in turnover of dominant follicles has not been defined. We concluded that two or three FSH-stimulated waves of follicular growth usually occur during the bovine estrous cycle, and each follicular wave culminates in development of a single nonovulatory or ovulatory dominant follicle.