Cost of Care for Patients With Cirrhosis.

INTRODUCTION: There are limited longitudinal data on the cost of treating patients with cirrhosis, which hampers value-based improvement initiatives. METHODS: We conducted a retrospective cohort study of patients with cirrhosis seen in the Veterans Affairs health care system from 2011 to 2015. Patients were followed up through 2019. We identified a sex-matched and age-matched control cohort without cirrhosis. We estimated incremental annual health care costs attributable to cirrhosis for 4 years overall and in subgroups based on severity (compensated, decompensated), cirrhosis complications (ascites, encephalopathy, varices, hepatocellular cancer, acute kidney injury), and comorbidity (Deyo index). RESULTS: We compared 39,361 patients with cirrhosis with 138,964 controls. The incremental adjusted costs for caring of patients with cirrhosis were $35,029 (95% confidence interval $32,473-$37,585) during the first year and ranged from $14,216 to $17,629 in the subsequent 3 years. Cirrhosis complications accounted for most of these costs. Costs of managing patients with hepatic encephalopathy (year 1 cost, $50,080) or ascites ($50,364) were higher than the costs of managing patients with varices ($20,488) or hepatocellular cancer ($37,639) in the first year. Patients with acute kidney injury or those who had multimorbidity were the most costly at $64,413 and $66,653 in the first year, respectively. DISCUSSION: Patients with cirrhosis had substantially higher health care costs than matched controls and multimorbid patients had even higher costs. Cirrhosis complications accounted for most of the excess cost, so preventing complications has the largest potential for cost saving and could serve as targets for improvement.

U.S. Primary Care Provider Needs: An Analysis of Workforce Projections and Policy Implications.

The primary care (PC) physician workforce has consistently been projected as requiring additional numbers to meet the needs of the U.S. The Health Resources and Service Administration (HRSA) has reported the PC nurse practitioner (NP) workforce to be 90,000 NPs more than required to meet the PC needs of the U.S. With both clinician types contributing to the PC workforce in the country, it is difficult to understand such an oversupply of NPs with continued deficit in PC physicians. The purpose of this study was to investigate results and methods used for HRSAs current PC workforce projections and compare those with the same used for Bureau of Labor Statistics (BLS) and American Association of Medical Colleges (AAMC) projections. Methods included a review of technical documents, dashboards, and published reports. Interviews with subject matter experts were also completed. Projections were found to differ significantly, as did data and assumptions. Two of the three projections modeled physicians as the sole provider of PC. An integrated model gives the most comprehensive and accurate picture of PC workforce needs. The utilization of NPs as PC providers has been demonstrated to be safe and effective, with the potential to alleviate predicted shortages, improve patient care outcomes, reduce cost, and address PC inequities. Implications include improving workforce data, creating projections that mirror clinical integration in PC, adjusting workforce preparation funding, incentivizing interprofessional collaboration in research, addressing barriers to practice among non-physician providers, and leveraging growth in the NP workforce.

Longitudinal Associations of Risk Factors and Hepatocellular Carcinoma in Patients With Cured Hepatitis C Virus Infection.

INTRODUCTION: There are limited data on the effect and evolution of risk factors for hepatocellular carcinoma (HCC) in patients with virologically cured hepatitis C virus (HCV) infection. METHODS: We conducted a retrospective cohort study of patients with HCV who achieved sustained virological response with direct-acting antivirals from 130 Veterans Administration hospitals during 2014-2018, followed through 2021. Cox proportional hazards models were constructed at 3 landmark times (baseline and 12 and 24 months after sustained virological response) to examine associations between demographic, clinical, and behavioral factors and HCC risk, stratified by cirrhosis status. RESULTS: Among 92,567 patients (32% cirrhosis), 3,247 cases of HCC were diagnosed during a mean follow-up of 2.5 years. In patients with cirrhosis, male sex (hazard ratios [HR]: 1.89, 1.93, and 1.99), cirrhosis duration ≥5 years (HR: 1.71, 1.79, and 1.34), varices (HR: 1.73, 1.60, and 1.56), baseline albumin (HR: 0.48, 0.47, and 0.49), and change in albumin (HR: 0.82 and 0.90) predicted HCC risk at each landmark time. HCV genotype 3, previous treatment, bilirubin, smoking, and race influenced HCC risk at baseline, but their effects attenuated over time. In patients without cirrhosis, diabetes (HR: 1.54, 1.42, and 1.47) and hypertension (HR: 1.59, 1.65, and 1.74) were associated with HCC risk at all landmark times. Changes in fibrosis-4 scores over time were associated with HCC risk both in patients with and without cirrhosis. DISCUSSION: Risk factors for HCC were different in patients with and without cirrhosis and some also evolved during follow-up. These factors can help with risk stratification and HCC surveillance decisions in patients with cured HCV.

Influence of Nitrite on Formation of Tobacco-Specific Nitrosamines in Electronic Cigarette Liquids and Aerosols.

Tobacco-specific nitrosamine (TSNA) formation occurred during aerosol generation from select commercial cig-a-like e-cigarette products. To understand the drivers behind the potential formation of TSNAs in electronic cigarette (e-cigarette) aerosols and e-liquids, model e-liquid systems were generated in the lab to demonstrate that nitrite can react with nicotine and minor alkaloids to form TSNAs in e-liquids. In the presence of nitrite and nicotine, TSNA levels in e-liquids increased over time and the process was accelerated by elevated temperature. Additionally, TSNAs formed during aerosol generation when nitrite was present in the corresponding e-liquids. The commercial e-cigarette products that showed higher levels and formation of TSNAs were observed to contain nitrite and minor alkaloid impurities in the corresponding e-liquids. This study provides valuable information about drivers for TSNA formation in e-liquids and e-cigarette aerosols that may be applied to the evaluation and quality assurance of e-cigarette products.

Implementation fidelity of a nurse-led RCT-tested complex intervention, care coordination for health promotion and activities in Parkinson's disease (CHAPS) in meeting challenges in care management.

BACKGROUND: Parkinson's disease (PD) complexity poses challenges for individuals with Parkinson's, providers, and researchers. A recent multisite randomized trial of a proactive, telephone-based, nurse-led care management intervention - Care Coordination for Health Promotion and Activities in Parkinson's Disease (CHAPS) - demonstrated improved PD care quality. Implementation details and supportive stakeholder feedback were subsequently published. To inform decisions on dissemination, CHAPS Model components require evaluations of their fidelity to the Chronic Care Model and to their implementation. Additionally, assessment is needed on whether CHAPS addresses care challenges cited in recent literature. METHODS: These analyses are based on data from a subset of 140 intervention arm participants and other CHAPS data. To examine CHAPS Model fidelity, we identified CHAPS components corresponding to the Chronic Care Model's six essential elements. To assess implementation fidelity of these components, we examined data corresponding to Hasson's modified implementation fidelity framework. Finally, we identified challenges cited in current Parkinson's care management literature, grouped these into themes using open card sorting techniques, and examined CHAPS data for evidence that CHAPS met these challenges. RESULTS: All Chronic Care Model essential elements were addressed by 17 CHAPS components, thus achieving CHAPS Model fidelity. CHAPS implementation fidelity was demonstrated by adherence to content, frequency, and duration with partial fidelity to telephone encounter frequency. We identified potential fidelity moderators for all six of Hasson's moderator types. Through card sorting, four Parkinson's care management challenge themes emerged: unmet needs and suggestions for providers (by patient and/or care partner), patient characteristics needing consideration, and standardizing models for Parkinson's care management. CHAPS activities and stakeholder perceptions addressed all these themes. CONCLUSIONS: CHAPS, a supportive nurse-led proactive Parkinson's care management program, improved care quality and is designed to be reproducible and supportive to clinicians. Findings indicated CHAPS Model fidelity occurred to the Chronic Care Model and fidelity to implementation of the CHAPS components was demonstrated. Current Parkinson's care management challenges were met through CHAPS activities. Thus, dissemination of CHAPS merits consideration by those responsible for implementing changes in clinical practice and reaching people in need. TRIAL REGISTRATION: ClinicalTrials.gov as NCT01532986 , registered on January 13, 2012.

Integrated Model for Patient-Centered Advanced Liver Disease Care.

Advanced liver disease (AdvLD) is a high-risk common condition with a progressive, highly morbid, and often fatal course. Despite effective treatments, there are substantial shortfalls in access to and use of evidence-based supportive and palliative care for AdvLD. Although patient-centered, chronic illness models that integrate early supportive and palliative care with curative treatments hold promise, there are several knowledge gaps that hinder development of an integrated model for AdvLD. We review these evidence gaps. We also describe a conceptual framework for a patient-centered approach that explicates key elements needed to improve integrated care. An integrated model of AdvLD would allow clinicians, patients, and caregivers to work collaboratively to identify treatments and other healthcare that best align with patients' priorities.

Stakeholder perceptions of components of a Parkinson disease care management intervention, care coordination for health promotion and activities in Parkinson's disease (CHAPS).

BACKGROUND: A recent nurse-led proactive care management intervention, Care Coordination for Health Promotion and Activities in Parkinson Disease (CHAPS), improved care quality when compared to usual care in a randomized controlled trial. Therefore, stakeholder (patient participants, nurse care managers, and Parkinson disease (PD) specialists) perceptions of key intervention components merit evaluation to inform decisions about dissemination. METHODS: This multi-site study occurred in five southwest United States Veterans Health Administration medical centers. Stakeholders were surveyed on their perceptions of CHAPS including the CHAPS Assessment, CHAPS nurse care managers, the Siebens Domain Management Model™ (a practical clinical model), and the Siebens Health Care Notebook (Notebook) (self-care tool). Participants' electronic medical records were abstracted for perceptions of the Notebook. Statistical analysis software was used to provide summary statistics; open card sorting methodology was used to identify themes and attributes in qualitative data including usability of some components. RESULTS: Participants, overall, highly rated their medication self-management, acknowledged some challenges with the CHAPS self-care tools, reported knowledge of PD specialist follow-up and PD red flags, and rated CHAPS nurse care managers as helpful. Nurse care manager responses indicated the CHAPS Assessment and Program highly facilitated care of their patients. Most all PD specialists would refer other patients to CHAPS. Nurse care manager and PD specialist responses indicated improved participant management of their PD. Three themes emerged in participant perceptions of the Notebook: Notebook Assets (e.g., benefits and features-liked); Deferring Notebook Review (e.g., no time to review); and Reasons for Not Using (e.g., participant preference). Shared attributes regarding the Siebens Domain Management Model and Notebook usability, reported by nurse care managers, were user-friendly, person/patient-centered, and organized. Some challenges to their use were also reported. CONCLUSIONS: Overall, stakeholder perceptions of the proactive nurse-led CHAPS intervention indicated its value in the care of individuals with PD. Responses about the CHAPS Assessment, Siebens Domain Management Model, and Notebook self-care tool signified their usefulness. Stakeholders' constructive suggestions indicated their engagement in CHAPS. These findings support CHAPS dissemination and contribute to research in care management. TRIAL REGISTRATION: ClinicalTrials.gov as NCT01532986 , registered on January 13, 2012.

Quality and extent of implementation of a nurse-led care management intervention: care coordination for health promotion and activities in Parkinson's disease (CHAPS).

BACKGROUND: A recent nurse-led, telephone-administered 18-month intervention, Care Coordination for Health Promotion and Activities in Parkinson's Disease (CHAPS), was tested in a randomized controlled trial and improved care quality. Therefore, intervention details on nurse care manager activity (types and frequencies) and participant actions are needed to support potential dissemination. Activities include nurse care manager use of a holistic organizing framework, identification of Parkinson's disease (PD)-related problems/topics, communication with PD specialists and care coordination, participant coaching, and participant self-care actions including use of a notebook self-care tool. METHODS: This article reports descriptive data on the CHAPS intervention. The study setting was five sites in the Veterans Affairs Healthcare System. Sociodemographic data were gathered from surveys of study participants (community-dwelling veterans with PD). Nurse care manager intervention activities were abstracted from electronic medical records and logbooks. Statistical analysis software was used to provide summary statistics; closed card sorting was used to group some data. RESULTS: Intervention participants (n = 140) were primarily men, mean age 69.4 years (standard deviation 10.3) and community-dwelling. All received the CHAPS Initial Assessment, which had algorithms designed to identify 31 unique CHAPS standard problems/topics. These were frequently documented (n = 4938), and 98.6% were grouped by assigned domain from the Organizing Framework (Siebens Domain Management Model™). Nurse care managers performed 27 unique activity types to address identified problems, collaborating with participants and PD specialists. The two most frequent unique activities were counseling/emotional support (n = 387) and medication management (n = 349). Both were among 2749 total performed activities in the category Implementing Interventions (coaching). Participants reported unique self-care action types (n = 23) including use of a new notebook self-care tool. CONCLUSIONS: CHAPS nurse care managers implemented multiple activities including participant coaching and care coordination per the CHAPS protocol. Participants reported various self-care actions including use of a personalized notebook. These findings indicate good quality and extent of implementation, contribute to ensuring reproducibility, and support CHAPS dissemination as a real-world approach to improve care quality. TRIAL REGISTRATION: ClinicalTrials.gov as NCT01532986 , registered on January 13, 2012.

Pathogenicity and a TaqMan Real-Time PCR for Specific Detection of Pantoea allii, a Bacterial Pathogen of Onions.

Bacterial diseases of onion are reported to cause significant economic losses. Pantoea allii Brady, one of the pathogens causing the center rot on onions, has not yet been reported in Canada. We report the pathogenicity of P. allii on commercially available Canadian green onions (scallions). All P. allii-inoculated plants, irrespective of the inoculum concentration, exhibited typical leaf chlorotic discoloration on green onion leaves, which can reduce their marketability. Reisolation of P. allii from infected scallion tissues and reidentification by sequencing and phylogenetic analyses of the leuS gene suggest that the pathogen can survive in infected tissues 21 days after inoculation. This is the first report of P. allii as a potential pathogen of green onions. This study also reports the development and validation of a TaqMan real-time PCR assay targeting the leuS gene for reliable detection of P. allii in pure cultures and in planta. A 642-bp leuS gene fragment was targeted because it showed high nucleotide diversity and positively correlated with genome-based average nucleotide identity with respect to percent similarity index and identity of Pantoea species. The assay specificity was validated using 61 bacterial and fungal strains. Under optimal conditions, the selected primers and FAM-labeled TaqMan probe were specific for the detection of nine reference P. allii strains by real-time PCR. The 52 strains of other Pantoea spp. (n = 25), non-Pantoea spp. (n = 20), and fungi/oomycetes (n = 7) tested negative (no detectable fluorescence). Onion tissues spiked with P. allii, naturally infested onion bulbs, greenhouse infected green onion leaf samples, as well as an interlaboratory blind test were used to validate the assay specificity. The sensitivities of a 1-pg DNA concentration and 30 CFU are comparable to previously reported real-time PCR assays of other bacterial pathogens. The TaqMan real-time PCR assay developed in this study will facilitate reliable detection of P. allii and could be a useful tool for screening onion imports or exports for the presence of this pathogen.

The linear mitochondrial genome of the quarantine chytrid Synchytrium endobioticum; insights into the evolution and recent history of an obligate biotrophic plant pathogen.

BACKGROUND: Chytridiomycota species (chytrids) belong to a basal lineage in the fungal kingdom. Inhabiting terrestrial and aquatic environments, most are free-living saprophytes but several species cause important diseases: e.g. Batrachochytrium dendrobatidis, responsible for worldwide amphibian decline; and Synchytrium endobioticum, causing potato wart disease. S. endobioticum has an obligate biotrophic lifestyle and isolates can be further characterized as pathotypes based on their virulence on a differential set of potato cultivars. Quarantine measures have been implemented globally to control the disease and prevent its spread. We used a comparative approach using chytrid mitogenomes to determine taxonomical relationships and to gain insights into the evolution and recent history of introductions of this plant pathogen. RESULTS: We assembled and annotated the complete mitochondrial genome of 30 S. endobioticum isolates and generated mitochondrial genomes for five additional chytrid species. The mitochondrial genome of S. endobioticum is linear with terminal inverted repeats which was validated by tailing and PCR amplifying the telomeric ends. Surprisingly, no conservation in organisation and orientation of mitochondrial genes was observed among the Chytridiomycota except for S. endobioticum and its sister species Synchytrium microbalum. However, the mitochondrial genome of S. microbalum is circular and comprises only a third of the 72.9 Kbp found for S. endobioticum suggesting recent linearization and expansion. Four mitochondrial lineages were identified in the S. endobioticum mitochondrial genomes. Several pathotypes occur in different lineages, suggesting that these have emerged independently. In addition, variations for polymorphic sites in the mitochondrial genome of individual isolates were observed demonstrating that S. endobioticum isolates represent a community of different genotypes. Such communities were shown to be complex and stable over time, but we also demonstrate that the use of semi-resistant potato cultivars triggers a rapid shift in the mitochondrial haplotype associated with increased virulence. CONCLUSIONS: Mitochondrial genomic variation shows that S. endobioticum has been introduced into Europe multiple times, that several pathotypes emerged multiple times, and that isolates represent communities of different genotypes. Our study represents the most comprehensive dataset of chytrid mitogenomes, which provides new insights into the extraordinary dynamics and evolution of mitochondrial genomes involving linearization, expansion and reshuffling.

A phase I trial of the γ-secretase inhibitor MK-0752 in combination with gemcitabine in patients with pancreatic ductal adenocarcinoma.

BACKGROUND: The Notch pathway is frequently activated in cancer. Pathway inhibition by γ-secretase inhibitors has been shown to be effective in pre-clinical models of pancreatic cancer, in combination with gemcitabine. METHODS: A multi-centre, non-randomised Bayesian adaptive design study of MK-0752, administered per os weekly, in combination with gemcitabine administered intravenously on days 1, 8 and 15 (28 day cycle) at 800 or 1000 mg m-2, was performed to determine the safety of combination treatment and the recommended phase 2 dose (RP2D). Secondary and tertiary objectives included tumour response, plasma and tumour MK-0752 concentration, and inhibition of the Notch pathway in hair follicles and tumour. RESULTS: Overall, 44 eligible patients (performance status 0 or 1 with adequate organ function) received gemcitabine and MK-0752 as first or second line treatment for pancreatic cancer. RP2Ds of MK-0752 and gemcitabine as single agents could be combined safely. The Bayesian algorithm allowed further dose escalation, but pharmacokinetic analysis showed no increase in MK-0752 AUC (area under the curve) beyond 1800 mg once weekly. Tumour response evaluation was available in 19 patients; 13 achieved stable disease and 1 patient achieved a confirmed partial response. CONCLUSIONS: Gemcitabine and a γ-secretase inhibitor (MK-0752) can be combined at their full, single-agent RP2Ds.

Frequency of nuclear mutant huntingtin inclusion formation in neurons and glia is cell-type-specific.

Huntington's disease (HD) is an autosomal dominant inherited neurodegenerative disorder that is caused by a CAG expansion in the Huntingtin (HTT) gene, leading to HTT inclusion formation in the brain. The mutant huntingtin protein (mHTT) is ubiquitously expressed and therefore nuclear inclusions could be present in all brain cells. The effects of nuclear inclusion formation have been mainly studied in neurons, while the effect on glia has been comparatively disregarded. Astrocytes, microglia, and oligodendrocytes are glial cells that are essential for normal brain function and are implicated in several neurological diseases. Here we examined the number of nuclear mHTT inclusions in both neurons and various types of glia in the two brain areas that are the most affected in HD, frontal cortex, and striatum. We compared nuclear mHTT inclusion body formation in three HD mouse models that express either full-length HTT or an N-terminal exon1 fragment of mHTT, and we observed nuclear inclusions in neurons, astrocytes, oligodendrocytes, and microglia. When studying the frequency of cells with nuclear inclusions in mice, we found that half of the population of neurons contained nuclear inclusions at the disease end stage, whereas the proportion of GFAP-positive astrocytes and oligodendrocytes having a nuclear inclusion was much lower, while microglia hardly showed any nuclear inclusions. Nuclear inclusions were also present in neurons and all studied glial cell types in human patient material. This is the first report to compare nuclear mHTT inclusions in glia and neurons in different HD mouse models and HD patient brains. GLIA 2016;65:50-61.

Dysfunction of the CNS-heart axis in mouse models of Huntington's disease.

Cardiac remodelling and contractile dysfunction occur during both acute and chronic disease processes including the accumulation of insoluble aggregates of misfolded amyloid proteins that are typical features of Alzheimer's, Parkinson's and Huntington's disease (HD). While HD has been described mainly as a neurological disease, multiple epidemiological studies have shown that HD patients exhibit a high incidence of cardiovascular events leading to heart failure, and that this is the second highest cause of death. Given that huntingtin is ubiquitously expressed, cardiomyocytes may be at risk of an HD-related dysfunction. In mice, the forced expression of an expanded polyQ repeat under the control of a cardiac specific promoter led to severe heart failure followed by reduced lifespan. However the mechanism leading to cardiac dysfunction in the clinical and pre-clinical HD settings remains unknown. To unravel this mechanism, we employed the R6/2 transgenic and HdhQ150 knock-in mouse models of HD. We found that pre-symptomatic animals developed connexin-43 relocation and a significant deregulation of hypertrophic markers and Bdnf transcripts. In the symptomatic animals, pronounced functional changes were visualised by cardiac MRI revealing a contractile dysfunction, which might be a part of dilatated cardiomyopathy (DCM). This was accompanied by the re-expression of foetal genes, apoptotic cardiomyocyte loss and a moderate degree of interstitial fibrosis. To our surprise, we could identify neither mutant HTT aggregates in cardiac tissue nor a HD-specific transcriptional dysregulation, even at the end stage of disease. We postulate that the HD-related cardiomyopathy is caused by altered central autonomic pathways although the pathogenic effects of mutant HTT acting intrinsically in the heart may also be a contributing factor.

Race and Gender Differences in the Use of Direct Acting Antiviral Agents for Hepatitis C Virus.

BACKGROUND: Direct acting antiviral agents (DAA) are highly effective yet expensive. Disparities by race and/or gender often exist in the use of costly medical advances as they become available. METHODS: We examined a cohort of hepatitis C virus (HCV) patients who received care at the Veterans Administration facilities nationwide. We evaluated the effect of race and gender on DAA receipt after adjusting for socioeconomic status, liver disease severity, comorbidity, and propensity for healthcare use. To determine if disparities had changed over time, we conducted a similar analysis of HCV patients who were seen in the previous standard of care treatment era. RESULTS: Of the 145 596 patients seen in the current DAA era, 17 791 (10.2%) received treatment during the first 16 months of DAA approval. Black patients had 21% lower odds of receiving DAA than whites (odds ratio [OR] = 0.79; 95% confidence interval [CI], .75, .84). Overall, women were as likely to receive treatment as men (OR = 0.99; 95% CI, .90-1.09). However, the odds of receiving DAAs were 29% lower for younger women compared with younger men (OR = 0.71, 95% CI, .54-.93). Similar to the DAA cohort, black patients had significantly lower odds of receiving treatment than whites (OR = 0.74, 95% CI, .69-.79) in the previous treatment era. The racial difference between the 2 eras did not reach statistical significance. CONCLUSIONS: There were unexplained differences among HCV population subgroups in the receipt of new DAA treatment. Targeted interventions are needed for black patients and younger women.

HDAC4 reduction: a novel therapeutic strategy to target cytoplasmic huntingtin and ameliorate neurodegeneration.

Histone deacetylase (HDAC) 4 is a transcriptional repressor that contains a glutamine-rich domain. We hypothesised that it may be involved in the molecular pathogenesis of Huntington's disease (HD), a protein-folding neurodegenerative disorder caused by an aggregation-prone polyglutamine expansion in the huntingtin protein. We found that HDAC4 associates with huntingtin in a polyglutamine-length-dependent manner and co-localises with cytoplasmic inclusions. We show that HDAC4 reduction delayed cytoplasmic aggregate formation, restored Bdnf transcript levels, and rescued neuronal and cortico-striatal synaptic function in HD mouse models. This was accompanied by an improvement in motor coordination, neurological phenotypes, and increased lifespan. Surprisingly, HDAC4 reduction had no effect on global transcriptional dysfunction and did not modulate nuclear huntingtin aggregation. Our results define a crucial role for the cytoplasmic aggregation process in the molecular pathology of HD. HDAC4 reduction presents a novel strategy for targeting huntingtin aggregation, which may be amenable to small-molecule therapeutics.

Development of Polymorphic Microsatellite Loci for Potato Wart from Next-Generation Sequence Data.

Synchytrium endobioticum is the fungal agent causing potato wart disease. Because of its severity and persistence, quarantine measures are enforced worldwide to avoid the spread of this disease. Molecular markers exist for species-specific detection of this pathogen, yet markers to study the intraspecific genetic diversity of S. endobioticum were not available. Whole-genome sequence data from Dutch pathotype 1 isolate MB42 of S. endobioticum were mined for perfect microsatellite motifs. Of the 62 selected microsatellites, 21 could be amplified successfully and displayed moderate levels of polymorphism in 22 S. endobioticum isolates from different countries. Nineteen multilocus genotypes were observed, with only three isolates from Canada displaying identical profiles. The majority of isolates from Canada clustered genetically. In contrast, most isolates collected in Europe show no genetic clustering associated with their geographic origin. S. endobioticum isolates with the same pathotype displayed highly variable genotypes and none of the microsatellite markers correlated with a specific pathotype. The markers developed in this study can be used to assess intraspecific genetic diversity of S. endobioticum and allow track and trace of genotypes that will generate a better understanding of the migration and spread of this important fungal pathogen and support management of this disease.

Toxicological assessment of a prototype e-cigaret device and three flavor formulations: a 90-day inhalation study in rats.

A prototype electronic cigaret device and three formulations were evaluated in a 90-day rat inhalation study followed by a 42-day recovery period. Animals were randomly assigned to groups for exposure to low-, mid- and high-dose levels of aerosols composed of vehicle (glycerin and propylene glycol mixture); vehicle and 2.0% nicotine; or vehicle, 2.0% nicotine and flavor mixture. Daily targeted aerosol total particulate matter (TPM) doses of 3.2, 9.6 and 32.0 mg/kg/day were achieved by exposure to 1 mg/L aerosol for 16, 48 and 160 min, respectively. Pre-study evaluations included indirect ophthalmoscopy, virology and bacteriological screening. Body weights, clinical observations and food consumption were monitored weekly. Plasma nicotine and cotinine and carboxyhemoglobin levels were measured at days 28 and 90. After days 28, 56 and 90, lung function measurements were obtained. Biological endpoints after 90-day exposure and 42-day recovery period included clinical pathology, urinalysis, bronchoalveolar fluid (BALF) analysis, necropsy and histopathology. Treatment-related effects following 90 days of exposure included changes in body weight, food consumption and respiratory rate. Dose-related decreases in thymus and spleen weights, and increased BALF lactate dehydrogenase, total protein, alveolar macrophages, neutrophils and lung weights were observed. Histopathology evaluations revealed sporadic increases in nasal section 1-4 epithelial hyperplasia and vacuolization. Following the recovery period, effects in the nose and BALF were persistent while other effects were resolved. The no observed effect level based upon body weight decreases is considered to be the mid-dose level for each formulation, equivalent to a daily TPM exposure dose of approximately 9.6 mg/kg/day.

Characterization of potential impurities and degradation products in electronic cigarette formulations and aerosols.

E-cigarettes are gaining popularity in the U.S. as well as in other global markets. Currently, limited published analytical data characterizing e-cigarette formulations (e-liquids) and aerosols exist. While FDA has not published a harmful and potentially harmful constituent (HPHC) list for e-cigarettes, the HPHC list for currently regulated tobacco products may be useful to analytically characterize e-cigarette aerosols. For example, most e-cigarette formulations contain propylene glycol and glycerin, which may produce aldehydes when heated. In addition, nicotine-related chemicals have been previously reported as potential e-cigarette formulation impurities. This study determined e-liquid formulation impurities and potentially harmful chemicals in aerosols of select commercial MarkTen(®) e-cigarettes manufactured by NuMark LLC. The potential hazard of the identified formulation impurities and aerosol chemicals was also estimated. E-cigarettes were machine puffed (4-s duration, 55-mL volume, 30-s intervals) to battery exhaustion to maximize aerosol collection. Aerosols analyzed for carbonyls were collected in 20-puff increments to account for analyte instability. Tobacco specific nitrosamines were measured at levels observed in pharmaceutical grade nicotine. Nicotine-related impurities in the e-cigarette formulations were below the identification and qualification thresholds proposed in ICH Guideline Q3B(R2). Levels of potentially harmful chemicals detected in the aerosols were determined to be below published occupational exposure limits.

Aberrant splicing of HTT generates the pathogenic exon 1 protein in Huntington disease.

Huntington disease (HD) is a devastating, late-onset, inherited neurodegenerative disorder that manifests with personality changes, movement disorders, and cognitive decline. It is caused by a CAG repeat expansion in exon 1 of the HTT gene that translates to a polyglutamine tract in the huntingtin protein (HTT). The formation of HTT fragments has been implicated as an essential step in the molecular pathogenesis of HD and several proteases that cleave HTT have been identified. However, the importance of smaller N-terminal fragments has been highlighted by their presence in HD postmortem brains and by the fact that nuclear inclusions are only detected by antibodies to the N terminus of HTT. Despite an intense research effort, the precise length of these fragments and the mechanism by which they are generated remains unknown. Here we show that CAG repeat length-dependent aberrant splicing of exon 1 HTT results in a short polyadenylated mRNA that is translated into an exon 1 HTT protein. Given that mutant exon 1 HTT proteins have consistently been shown to be highly pathogenic in HD mouse models, the aberrant splicing of HTT mRNA provides a mechanistic basis for the molecular pathogenesis of HD. RNA-targeted therapeutic strategies designed to lower the levels of HTT are under development. Many of these approaches would not prevent the production of exon 1 HTT and should be reviewed in light of our findings.

Characterisation of immune cell function in fragment and full-length Huntington's disease mouse models.

Inflammation is a growing area of research in neurodegeneration. In Huntington's disease (HD), a fatal inherited neurodegenerative disease caused by a CAG-repeat expansion in the gene encoding huntingtin, patients have increased plasma levels of inflammatory cytokines and circulating monocytes that are hyper-responsive to immune stimuli. Several mouse models of HD also show elevated plasma levels of inflammatory cytokines. To further determine the degree to which these models recapitulate observations in HD patients, we evaluated various myeloid cell populations from different HD mouse models to determine whether they are similarly hyper-responsive, as well as measuring other aspects of myeloid cell function. Myeloid cells from each of the three mouse models studied, R6/2, HdhQ150 knock-in and YAC128, showed increased cytokine production when stimulated. However, bone marrow CD11b(+) cells did not show the same hyper-responsive phenotype as spleen and blood cells. Furthermore, macrophages isolated from R6/2 mice show increased levels of phagocytosis, similar to findings in HD patients. Taken together, these results show significant promise for these mouse models to be used to study targeting innate immune pathways identified in human cells, thereby helping to understand the role the peripheral immune system plays in HD progression.