Gene therapy for glycogen storage diseases.

Glycogen storage disorders (GSDs) are inherited disorders of metabolism resulting from the deficiency of individual enzymes involved in the synthesis, transport, and degradation of glycogen. This literature review summarizes the development of gene therapy for the GSDs. The abnormal accumulation of glycogen and deficiency of glucose production in GSDs lead to unique symptoms based upon the enzyme step and tissues involved, such as liver and kidney involvement associated with severe hypoglycemia during fasting and the risk of long-term complications including hepatic adenoma/carcinoma and end stage kidney disease in GSD Ia from glucose-6-phosphatase deficiency, and cardiac/skeletal/smooth muscle involvement associated with myopathy +/- cardiomyopathy and the risk for cardiorespiratory failure in Pompe disease. These symptoms are present to a variable degree in animal models for the GSDs, which have been utilized to evaluate new therapies including gene therapy and genome editing. Gene therapy for Pompe disease and GSD Ia has progressed to Phase I and Phase III clinical trials, respectively, and are evaluating the safety and bioactivity of adeno-associated virus vectors. Clinical research to understand the natural history and progression of the GSDs provides invaluable outcome measures that serve as endpoints to evaluate benefits in clinical trials. While promising, gene therapy and genome editing face challenges with regard to clinical implementation, including immune responses and toxicities that have been revealed during clinical trials of gene therapy that are underway. Gene therapy for the glycogen storage diseases is under development, addressing an unmet need for specific, stable therapy for these conditions.

Phenotypically driven subgroups of ASD display distinct metabolomic profiles.

Autism Spectrum Disorder (ASD) is a heterogeneous condition that includes a broad range of characteristics and associated comorbidities; however, the biology underlying the variability in phenotypes is not well understood. As ASD impacts approximately 1 in 100 children globally, there is an urgent need to better understand the biological mechanisms that contribute to features of ASD. In this study, we leveraged rich phenotypic and diagnostic information related to ASD in 2001 individuals aged 4 to 17 years from the Simons Simplex Collection to derive phenotypically driven subgroups and investigate their respective metabolomes. We performed hierarchical clustering on 40 phenotypes spanning four ASD clinical domains, resulting in three subgroups with distinct phenotype patterns. Using global plasma metabolomic profiling generated by ultrahigh-performance liquid chromatography mass spectrometry, we characterized the metabolome of individuals in each subgroup to interrogate underlying biology related to the subgroups. Subgroup 1 included children with the least maladaptive behavioral traits (N = 862); global decreases in lipid metabolites and concomitant increases in amino acid and nucleotide pathways were observed for children in this subgroup. Subgroup 2 included children with the highest degree of challenges across all phenotype domains (N = 631), and their metabolome profiles demonstrated aberrant metabolism of membrane lipids and increases in lipid oxidation products. Subgroup 3 included children with maladaptive behaviors and co-occurring conditions that showed the highest IQ scores (N = 508); these individuals had increases in sphingolipid metabolites and fatty acid byproducts. Overall, these findings indicated distinct metabolic patterns within ASD subgroups, which may reflect the biological mechanisms giving rise to specific patterns of ASD characteristics. Our results may have important clinical applications relevant to personalized medicine approaches towards managing ASD symptoms.

Neurodevelopmental phenotypes associated with pathogenic variants in SLC6A1.

BACKGROUND: SLC6A1 encodes GAT-1, a major gamma-aminobutyric acid (GABA) transporter in the brain. GAT-1 maintains neurotransmitter homeostasis by removing excess GABA from the synaptic cleft. Pathogenic variants in SLC6A1 disrupt the reuptake of GABA and are associated with a neurobehavioural phenotype. METHODS: Medical history interviews, seizure surveys, Vineland Adaptive Behavior Scales Second Edition and other behavioural surveys were completed by primary care givers of 28 participants in Simons Searchlight. All participants underwent clinical whole exome sequencing or gene panel sequencing. Additional cases from the medical literature with comparable data were included. RESULTS: We identified 28 individuals with largely de novo pathogenic/likely pathogenic variants including missense (15/21 or 71%) and truncating variants (6/21 or 29%). Missense variants were largely clustered around the sixth and seventh transmembrane domains, which functions as a GABA binding pocket. The phenotype of individuals with pathogenic variants in SLC6A1 includes hypotonia, intellectual disability/developmental delay, language disorder/speech delay, autism spectrum disorder, sleep issues and seizures. CONCLUSION: Pathogenic variants in SLC6A1 are associated with a clinical phenotype of developmental delay, behaviour problems and seizures. Understanding of the genotype-phenotype correlation within SLC6A1 may provide opportunities to develop new treatments for GABA-related conditions.

Characterization of phenotypic range in DYRK1A haploinsufficiency syndrome using standardized behavioral measures.

DYRK1A haploinsufficiency syndrome is a well-established neurodevelopmental disorder, but detailed information on the range of cognitive and behavioral issues associated with the condition is limited. We studied 24 participants with likely pathogenic or pathogenic variants in DYRK1A through the Simons Searchlight study and systematically assessed their medical history and development using standardized instruments: Vineland Adaptive Behavior Scale II (VABS-II) and Child Behavior Checklists/1.5-5 and 6-18 (CBCL/1.5-5, CBCL/6-18). All of the individuals in the cohort had neurological manifestations including intellectual disability or developmental delay, microcephaly, autism spectrum disorder, and/or seizures. The severity of the neurodevelopmental disorder was variable with a few children scoring in the moderately low range on the adaptive behavior composite score on the VABS-II. This study confirms the association of DYRK1A haploinsufficiency with neurodevelopmental disabilities, microcephaly, autism spectrum disorder, and epilepsy and quantifies the range of adaptive behaviors.

Bezafibrate induces autophagy and improves hepatic lipid metabolism in glycogen storage disease type Ia.

Glucose-6-phosphatase α (G6Pase) deficiency, also known as von Gierke's Disease or Glycogen storage disease type Ia (GSD Ia), is characterized by decreased ability of the liver to convert glucose-6-phosphate to glucose leading to glycogen accumulation and hepatosteatosis. Long-term complications of GSD Ia include hepatic adenomas and carcinomas, in association with the suppression of autophagy in the liver. The G6pc-/- mouse and canine models for GSD Ia were treated with the pan-peroxisomal proliferator-activated receptor agonist, bezafibrate, to determine the drug's effect on liver metabolism and function. Hepatic glycogen and triglyceride concentrations were measured and western blotting was performed to investigate pathways affected by the treatment. Bezafibrate decreased liver triglyceride and glycogen concentrations and partially reversed the autophagy defect previously demonstrated in GSD Ia models. Changes in medium-chain acyl-CoA dehydrogenase expression and acylcarnintine flux suggested that fatty acid oxidation was increased and fatty acid synthase expression associated with lipogenesis was decreased in G6pc-/- mice treated with bezafibrate. In summary, bezafibrate induced autophagy in the liver while increasing fatty acid oxidation and decreasing lipogenesis in G6pc-/- mice. It represents a potential therapy for glycogen overload and hepatosteatosis associated with GSD Ia, with beneficial effects that have implications for non-alcoholic fatty liver disease.

To contemplate or not to contemplate evaluating a preliminary intervention proposal in an outpatient setting: the contemplation therapy group.

PURPOSE: The concept for the contemplation group intervention was derived from motivational interviewing (MI) to support people suffering from an eating disorder who are reluctant to engage with treatment. This evaluation focuses on the contemplation group run by the eating disorder services in the Cardiff and Vale area between 2012 and 2016 to investigate the outcomes for participants and implications for working with people suffering from an eating disorder who are ambivalent about change. METHOD: Quantitative measures were used to assess eating disorder symptomatology, motivation to change and location within the stages of change model. A brief qualitative evaluation of client experiences was also included. RESULTS: While dropout was high, a number of patients displayed increased readiness for treatment at the end of the group or even started to engage in change-focussed therapy. Participants who completed the group described it as challenging but helpful. CONCLUSIONS: This evaluation shows that explorative contemplation of their ambivalence towards their eating disorder and treatment was helpful for the participants of the group and supported them in achieving more clarity and decisiveness regarding whether to engage in treatment or not. Further research is needed to evaluate long-term outcomes for patients who feel ambivalent towards treatment, and to explore what interventions can be used to help them. EVIDENCE LEVEL: Level IV: Evidence obtained from multiple time series with or without the intervention.

Comparative cost-effectiveness analysis of the subacromial spacer for irreparable and massive rotator cuff tears.

PURPOSE: There is ongoing debate regarding the optimal surgical treatment of irreparable rotator cuff tears (IRCT). This study aimed to assess within the Italian health care system the cost-effectiveness of subacromial spacer as a treatment modality for patients with IRCT. METHODS: An expected-value decision analysis was created comparing costs and outcomes of patients undergoing arthroscopic subacromial spacer implantation, rotator cuff repair (RCR), total shoulder arthroplasty, and conservative treatment for IRCTs. A broad literature search provided input data to extrapolate and inform treatment success and failure rates, costs, and health utility states for these outcomes. The primary outcome assessed was an incremental cost-effectiveness ratio (ICER) of subacromial spacer implantation versus shoulder arthroplasty, RCR, and conservative treatment. RESULTS: Subacromial spacer is favorable over both arthroscopic partial repair and shoulder arthroplasty since it costs less than both options and increases effectiveness by 0.06 and 0.10 quality-adjusted life years (QALYs), respectively. While conservative treatment is the least costly management strategy, subacromial spacer results in a gain of 0.05 QALYs for the additional cost of 522 €, resulting in an ICER of 10,440 €/QALY gain, which is below the standard willingness to pay ratio of $50,000 USD. Strategies with an ICER of less than 50,000 USD are considered to be cost-effective. CONCLUSIONS: Based on the available evidence and reasonably conservative assumptions, subacromial spacer is likely to provide a safe, effective, and cost-effective option for patients with massive IRCTs. Furthermore, this cost-effectiveness analysis may ultimately serve as a guide for development of health care system and insurer policy as well as clinical practice.

Meta-Analysis of Local Invasive Breast Cancer Recurrence After Electron Intraoperative Radiotherapy.

BACKGROUND: Electron intraoperative radiotherapy (IORT) can be used during breast conserving surgery to treat early-stage invasive breast cancer. Using data from current clinical and observational studies, this study aimed to assess the impact of single-fraction electron IORT on local recurrence rates. METHODS: Studies on single-fraction electron IORT during breast conserving surgery were identified through a search of PubMed and Google Scholar, as well as through secondary referencing. Local recurrence rate was the main outcome of interest. A meta-analysis of proportions using a binomial distribution to model the within-study variability and a random effects model was conducted to estimate a pooled local recurrence rate. To estimate a 5-year recurrence rate, a single-sample Poisson-normal model was applied to model the probability of events occurring during a fixed period (60 months). RESULTS: The study identified 13 publications. The analysis demonstrated a pooled monthly local recurrence rate of 0.02% per person-month (95% confidence interval CI 0.00-0.06%) for the studies with a follow-up period shorter than 5 years, 0.03% per person-month (95% CI 0.02-0.06%) for studies with a follow-up period of 5 years or longer, and 0.02% per person-month (95% CI 0.01-0.04%) overall. Based on this model, the predicted 5-year local recurrence rate was 2.7% (range 1.9-3.7%). CONCLUSIONS: According to the published literature, the rate of breast cancer local recurrence after electron IORT was 0.02% per person-month, with an adjusted 5-year recurrence rate of 2.7%. These findings support the recent guidelines from the American Society for Radiation Oncology (ASTRO) supporting the use of electron IORT for low-risk patients.

Long-term complications of glycogen storage disease type Ia in the canine model treated with gene replacement therapy.

BACKGROUND: Glycogen storage disease type Ia (GSD Ia) in dogs closely resembles human GSD Ia. Untreated patients with GSD Ia develop complications associated with glucose-6-phosphatase (G6Pase) deficiency. Survival of human patients on intensive nutritional management has improved; however, long-term complications persist including renal failure, nephrolithiasis, hepatocellular adenomas (HCA), and a high risk for hepatocellular carcinoma (HCC). Affected dogs fail to thrive with dietary therapy alone. Treatment with gene replacement therapy using adeno-associated viral vectors (AAV) expressing G6Pase has greatly prolonged life and prevented hypoglycemia in affected dogs. However, long-term complications have not been described to date. METHODS: Five GSD Ia-affected dogs treated with AAV-G6Pase were evaluated. Dogs were euthanized due to reaching humane endpoints related to liver and/or kidney involvement, at 4 to 8 years of life. Necropsies were performed and tissues were analyzed. RESULTS: Four dogs had liver tumors consistent with HCA and HCC. Three dogs developed renal failure, but all dogs exhibited progressive kidney disease histologically. Urolithiasis was detected in two dogs; uroliths were composed of calcium oxalate and calcium phosphate. One affected and one carrier dog had polycystic ovarian disease. Bone mineral density was not significantly affected. CONCLUSIONS: Here, we show that the canine GSD Ia model demonstrates similar long-term complications as GSD Ia patients in spite of gene replacement therapy. Further development of gene therapy is needed to develop a more effective treatment to prevent long-term complications of GSD Ia.

Long-term quality of life improvement for chronic intractable back and leg pain patients using spinal cord stimulation: 12-month results from the SENZA-RCT.

PURPOSE: Chronic axial low-back pain is a debilitating disorder that impacts all aspects of an afflicted individual's life. Effective, durable treatments have historically been elusive. Interventional therapies, such as spinal cord stimulation (SCS), have shown limited efficacy at best. Recently, a novel treatment, 10 kHz SCS, has demonstrated superior pain relief compared with traditional SCS in a randomized controlled trial (RCT). In this manuscript, we report on the long-term improvements in quality of life (QoL) outcomes for subjects enrolled in this study. METHODS: A prospective, multicenter, randomized controlled trial (SENZA-RCT) was conducted. Patients with both chronic back and leg pain were enrolled and randomized (1:1) into 10 kHz SCS or traditional SCS treatment groups. A total of 171 subjects received a permanent SCS device implant. QoL and functionality measures were collected up to 12 months. The device remote control utilization, which is an indication of patient interaction with the device for adjustments, was collected at 24-month post-implantation. RESULTS: At 12 months, a higher proportion of 10 kHz SCS subjects had marked improvement of their disability (Oswestry Disability Index) to a "moderate" or "minimal" impact on their daily function versus the control group. The subjects also reported better improvement in the Global Assessment of Functioning, Clinician Global Impression of Change, Pittsburgh Sleep Quality Index, and short-form McGill Pain Questionnaire, compared to traditional SCS subjects. The 10 kHz SCS subjects also reported far higher rates of both driving and sleeping with their device turned on, as well as reduced reliance on their programmers to adjust therapy settings. CONCLUSIONS: In addition to superior pain relief, 10 kHz SCS provides long-term improvements in quality of life and functionality for subjects with chronic low-back and leg pain. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01609972).

Personal exposure of dairy workers to dust, endotoxin, muramic acid, ergosterol, and ammonia on large-scale dairies in the high plains Western United States.

Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological and chemical constituents, which have been tied to adverse health effects. A better understanding of the variation in the magnitude and composition of exposures by task is needed to inform worker protection strategies. To characterize the levels and types of exposures, 115 dairy workers grouped into three task categories on nine farms in the high plains Western United States underwent personal monitoring for inhalable dust, endotoxin, 3-hydroxy fatty acids (3-OHFA), muramic acid, ergosterol, and ammonia through one work shift. Eighty-nine percent of dairy workers were exposed to endotoxin at concentrations exceeding the recommended exposure guidelines (adjusted for a long work shift). The proportion of workers with exposures exceeding recommended guidelines was lower for inhalable dust (12%), and ammonia (1%). Ergosterol exposures were only measurable on 28% of samples, primarily among medical workers and feed handlers. Milking parlor workers were exposed to significantly higher inhalable dust, endotoxin, 3-OHFA, ammonia, and muramic acid concentrations compared to workers performing other tasks. Development of large modern dairies has successfully made progress in reducing worker exposures and lung disease prevalence. However, exposure to endotoxin, dust, and ammonia continues to present a significant risk to worker health on North American dairies, especially for workers in milking parlors. This study was among the first to concurrently evaluate occupational exposure to assayable endotoxin (lipid A), 3-hydroxy fatty acids or 3-OHFA (a chemical measure of cell bound and noncell-bound endotoxins), muramic acid, ergosterol, and ammonia among workers on Western U.S. dairies. There remains a need for cost-effective, culturally acceptable intervention strategies integrated in OHS Risk Management and production systems to further optimize worker health and farm productivity.

Cost-Effectiveness Analysis of Monitoring Fractional Exhaled Nitric Oxide (FeNO) in the Management of Asthma.

PURPOSE: Current asthma guidelines combine treatment, follow-up, and reevaluation to manage asthma control, reduce impairment, and decrease risk of morbidity in patients. Clinical use of biomarkers, such as fractional exhaled nitric oxide (FeNO), along with standard management can provide clinicians with improved ability to recognize airway inflammation, optimize drug therapy, and potentially increase asthma control. Our objective is to examine the impact of FeNO monitoring on the cost effectiveness of asthma management compared with management without FeNO. Sensitivity analyses further examine the impact of FeNO monitoring on patients with varying levels of severity and exacerbations. DESIGN AND METHODS: A decision-tree analysis of estimated outcomes and costs associated with annual management of asthma was utilized to simulate asthma management and treatment cost scenarios, comparing estimated 12-month costs and outcomes using the following treatment alternatives: (1) current standard of care (SOC) or (2) FeNO utilized in conjunction with the current SOC. Costs were estimated from the perspective of the health care payer; cost effectiveness was estimated as cost per quality-adjusted life year (QALY). RESULTS: FeNO in conjunction with SOC guidelines has decreased expected per-patient annual expenditure ($2,228) and increased expected per-patient annual QALYs (0.844) compared with SOC alone ($2,637 and 0.767). FeNO monitoring with SOC resulted in decreased annual costs and increased annual QALYs compared with SOC alone, and this difference was consistent through all one-way sensitivity analyses. CONCLUSION: Our analysis revealed that FeNO monitoring to guide asthma management is cost effective and could result in increased QALYs and decreased health care costs associated with asthma management.

A Review of the Utility and Cost Effectiveness of Monitoring Fractional Exhaled Nitric Oxide (FeNO) in Asthma Management.

Asthma is a common chronic respiratory disease affecting nearly 8% of the U.S. POPULATION: It results in substantially higher direct and indirect costs as well as an increased mortality risk and poorer quality of life, particularly among patients with difficult-to-control asthma. While several physiologic tests, including spirometry, are typically used to diagnose and characterize asthma, they do not provide the sensitivity and specificity required to accurately reflect the underlying heterogeneous inflammatory pathways. Fractional exhaled nitric oxide (FeNO) is a validated, noninvasive biomarker for T2-driven (i.e., allergic) airway inflammation that correlates with sputum eosinophils at or greater than 3% across various asthma phenotypes. Its use as a biomarker in asthma is well supported by numerous peer-reviewed articles and guidelines. There is also evidence that its use in clinical settings for patients with uncontrolled asthma is cost effective, given its ability to improve the accurate diagnosis of asthma, monitor treatment response, optimize inhaled corticosteroid dosing, and identify patient nonadherence. It may also have a role in identifying patients who are possible candidates for treatment with biologics.

In Vivo Zinc Finger Nuclease-mediated Targeted Integration of a Glucose-6-phosphatase Transgene Promotes Survival in Mice With Glycogen Storage Disease Type IA.

Glycogen storage disease type Ia (GSD Ia) is caused by glucose-6-phosphatase (G6Pase) deficiency in association with severe, life-threatening hypoglycemia that necessitates lifelong dietary therapy. Here we show that use of a zinc-finger nuclease (ZFN) targeted to the ROSA26 safe harbor locus and a ROSA26-targeting vector containing a G6PC donor transgene, both delivered with adeno-associated virus (AAV) vectors, markedly improved survival of G6Pase knockout (G6Pase-KO) mice compared with mice receiving the donor vector alone (P < 0.04). Furthermore, transgene integration has been confirmed by sequencing in the majority of the mice treated with both vectors. Targeted alleles were 4.6-fold more common in livers of mice with GSD Ia, as compared with normal littermates, at 8 months following vector administration (P < 0.02). This suggests a selective advantage for vector-transduced hepatocytes following ZFN-mediated integration of the G6Pase vector. A short-term experiment also showed that 3-month-old mice receiving the ZFN had significantly-improved biochemical correction, in comparison with mice that received the donor vector alone. These data suggest that the use of ZFNs to drive integration of G6Pase at a safe harbor locus might improve vector persistence and efficacy, and lower mortality in GSD Ia.

Induction of autophagy improves hepatic lipid metabolism in glucose-6-phosphatase deficiency.

BACKGROUND & AIMS: Glucose-6-phosphatase (G6Pase α, G6PC) deficiency, also known as von Gierke's disease or GSDIa, is the most common glycogen storage disorder. It is characterized by a decreased ability of the liver to convert glucose-6-phosphate (G6P) to glucose leading to glycogen and lipid over-accumulation progressing to liver failure and/or hepatomas and carcinomas. Autophagy of intracellular lipid stores (lipophagy) has been shown to stimulate fatty acid ß-oxidation in hepatic cells. Thus, we examined autophagy and its effects on reducing hepatic lipid over-accumulation in several cell culture and animal models of GSDIa. METHODS: Autophagy in G6PC-deficient hepatic cell lines, mice, and dogs was measured by Western blotting for key autophagy markers. Pro-autophagic Unc51-like kinase 1 (ULK1/ATG1) was overexpressed in G6PC-deficient hepatic cells, and lipid clearance and oxidative phosphorylation measured. G6PC(-/-) mice and GSDIa dogs were treated with rapamycin and assessed for liver function. RESULTS: Autophagy was impaired in the cell culture, mouse, and canine models of GSDIa. Stimulation of the anti-autophagic mTOR, and inhibition of the pro-autophagic AMPK pathways occurred both in vitro and in vivo. Induction of autophagy by ULK1/ATG1 overexpression decreased lipid accumulation and increased oxidative phosphorylation in G6PC-deficient hepatic cells. Rapamycin treatment induced autophagy and decreased hepatic triglyceride and glycogen content in G6PC(-/-) mice, as well as reduced liver size and improved circulating markers of liver damage in GSDIa dogs. CONCLUSIONS: Autophagy is impaired in GSDIa. Pharmacological induction of autophagy corrects hepatic lipid over-accumulation and may represent a new therapeutic strategy for GSDIa.

Large animal models and new therapies for glycogen storage disease.

Glycogen storage diseases (GSD), a unique category of inherited metabolic disorders, were first described early in the twentieth century. Since then, the biochemical and genetic bases of these disorders have been determined, and an increasing number of animal models for GSD have become available. At least seven large mammalian models have been developed for laboratory research on GSDs. These models have facilitated the development of new therapies, including gene therapy, which are undergoing clinical translation. For example, gene therapy prolonged survival and prevented hypoglycemia during fasting for greater than one year in dogs with GSD type Ia, and the need for periodic re-administration to maintain efficacy was demonstrated in that dog model. The further development of gene therapy could provide curative therapy for patients with GSD and other inherited metabolic disorders.

Costs and benefits of bundled community-based screening for carotid artery stenosis, peripheral artery disease, and abdominal aortic aneurysm.

PURPOSE: Perform an initial formal assessment of the costs and benefits of bundled cardiovascular screening. Primarily, determine the relative importance of data uncertainties to the integrity ofmodeled outcomes associated with bundled screening for carotid artery stenosis (CAS), peripheral artery disease (PAD), and abdominal aortic aneurysm (AAA); secondarily, establish parameters around potential costs and outcomes benefits of this screening bundle. DESIGN: A decision-analysis framework composed of four decision tree submodels with transition probabilities specific to four age- and gender-specific subgroups. Model transition probabilities for each of the four submodels are based on the prevalence of all possible combinations of the presence or absence of moderate CAS, significant CAS, PAD, and AAA, and the likelihood of appropriate or inappropriate medical follow-up. METHODOLOGY: Evaluates a hypothetical self-funded employer with 10,000 beneficiaries and who is considering whether to provide bundled cardiovascular health screenings. Screenings would be performed in addition to any other medical screenings commonly performed by physicians to assess cardiovascular risk. Determine costs and catastrophic events (death, myocardial infarction, stroke, other cardiovascular-related events, amputation events) for these self-funded hypothetical beneficiaries aged ≥ 50 years and < 65 years. RESULTS: The model predicts approximately $54 million in health care costs over 10 years for the control cohort and $51 million for the screening cohort, representing a 5.2% reduction in 10-year health care spending due to screening. CONCLUSION: This initial analysis predicts robust cost and health benefits associated with the decision to provide bundled cardiovascular health screening to a self-funded employer's beneficiaries aged ≥ 50 years and < 65 years. Further analyses are necessary to better quantify the magnitude of the cost and health benefits.

Limited activity of clofazimine as a single drug in a mouse model of tuberculosis exhibiting caseous necrotic granulomas.

New drugs and drugs with a novel mechanism of action are desperately needed to shorten the duration of tuberculosis treatment, to prevent the emergence of drug resistance, and to treat multiple-drug-resistant strains of Mycobacterium tuberculosis. Recently, there has been renewed interest in clofazimine (CFZ). In this study, we utilized the C3HeB/FeJ mouse model, possessing highly organized, hypoxic pulmonary granulomas with caseous necrosis, to evaluate CFZ monotherapy in comparison to results with BALB/c mice, which form only multifocal, coalescing cellular aggregates devoid of caseous necrosis. While CFZ treatment was highly effective in BALB/c mice, its activity was attenuated in the lungs of C3HeB/FeJ mice. This lack of efficacy was directly related to the pathological progression of disease in these mice, since administration of CFZ prior to the formation of hypoxic, necrotic granulomas reconstituted bactericidal activity in this mouse strain. These results support the continued use of mouse models of tuberculosis infection which exhibit a granulomatous response in the lungs that more closely resembles the pathology found in human disease.

GM-CSF knockout mice for preclinical testing of agents with antimicrobial activity against Mycobacterium abscessus.

OBJECTIVES: Of the non-tuberculous mycobacteria, Mycobacterium abscessus is particularly refractory to antimicrobial therapy and new agents with activity against these pathogens are urgently needed. The screening of candidate antimicrobial agents against M. abscessus requires a relevant and reproducible animal model of chronic infection. Granulocyte-macrophage colony-stimulating factor knockout (GM-CSF KO) mice were used to develop a new animal model of chronic pulmonary M. abscessus infection that can be used for preclinical efficacy testing of antimicrobial drugs. METHODS: GM-CSF KO mice were infected with a clinical isolate of M. abscessus via intrapulmonary aerosol delivery using a microsprayer device. The clinical condition, histology and cfu of M. abscessus-infected GM-CSF KO mice were evaluated over a period of 4 months. Mice were treated with azithromycin (100 mg/kg) by oral gavage and the clinical condition, histology and bacterial burden was determined after 2 weeks of treatment. RESULTS: We show that pulmonary infection of GM-CSF KO mice with M. abscessus results in a chronic pulmonary infection that lends itself to preclinical testing of new antimicrobial drugs against this bacterium. Azithromycin treatment of M. abscessus-infected GM-CSF KO mice resulted in a lower bacterial burden in the lungs and spleen, weight gain and significant improvement in lung pathology. CONCLUSIONS: Intrapulmonary aerosol infection of GM-CSF KO mice with M. abscessus is a useful animal model for studying pathogenesis as well as pre-clinical testing of new compounds against M. abscessus in acute or chronic phases of infection.

Providing culturally competent services for American Indian and Alaska Native veterans to reduce health care disparities.

OBJECTIVES: We conducted an exploratory study to determine what organizational characteristics predict the provision of culturally competent services for American Indian and Alaska Native (AI/AN) veterans in Department of Veterans Affairs (VA) health facilities. METHODS: In 2011 to 2012, we adapted the Organizational Readiness to Change Assessment (ORCA) for a survey of 27 VA facilities in the Western Region to assess organizational readiness and capacity to adopt and implement native-specific services and to profile the availability of AI/AN veteran programs and interest in and resources for such programs. RESULTS: Several ORCA subscales (Program Needs, Leader's Practices, and Communication) statistically significantly predicted whether VA staff perceived that their facilities were meeting the needs of AI/AN veterans. However, none predicted greater implementation of native-specific services. CONCLUSIONS: Our findings may aid in developing strategies for adopting and implementing promising native-specific programs and services for AI/AN veterans, and may be generalizable for other veteran groups.