Statins and PPARalpha agonists induce myotoxicity in differentiated rat skeletal muscle cultures but do not exhibit synergy with co-treatment

Statins and fibrates (weak PPARalpha agonists) are prescribed for the treatment of lipid disorders. Both drugs cause myopathy, but with a low incidence, 0.1-0.5%. However, combined statin and fibrate therapy can enhance myopathy risk. We tested the myotoxic potential of PPAR subtype selective agonists alone and in combination with statins in a differentiated rat myotube model. A pharmacologically potent experimental PPARalpha agonist, Compound A, induced myotoxicity as assessed by TUNEL staining at a minimum concentration of 1 nM, while other weaker PPARalpha compounds, for example, WY-14643, Gemfibrozil and Bezafibrate increased the percentage of TUNEL-positive nuclei at micromolar concentrations. In contrast, the PPARgamma agonist Rosiglitazone caused little or no cell death at up to 10 muM and the PPARdelta ligand GW-501516 exhibited comparatively less myotoxicity than that seen with Compound A. An experimental statin (Compound B) and Atorvastatin also increased the percentage of TUNEL-positive nuclei and co-treatment with WY-14643, Gemfibrozil or Bezafibrate had less than a full additive effect on statin-induced cell killing. The mechanism of PPARalpha agonist-induced cell death was different from that of statins. Unlike statins, Compound A and WY-14643 did not activate caspase 3/7. In addition, mevalonate and geranylgeraniol reversed the toxicity caused by statins, but did not prevent the cell killing induced by WY-14643. Furthermore, unlike statins, Compound A did not inhibit the isoprenylation of rab4 or rap1a. Interestingly, Compound A and Compound B had differential effects on ATP levels. Taken together, these observations support the hypothesis that in rat myotube cultures, PPARalpha agonism mediates in part the toxicity response to PPARalpha compounds. Furthermore, PPARalpha agonists and statins cause myotoxicity through distinct and independent pathways.     

Vital Signs: Fruit and Vegetable Intake Among Children — United States, 2003–2010

Background

Eating more fruits and vegetables adds underconsumed nutrients to diets, reduces the risks for leading causes of illness and death, and helps manage body weight. This report describes trends in the contributions of fruits and vegetables to the diets of children aged 2–18 years.

Methods

CDC analyzed 1 day of 24-hour dietary recalls from the National Health and Nutrition Examination Surveys from 2003 to 2010 to estimate trends in children’s fruit and vegetable intake in cup-equivalents per 1,000 calories (CEPC) and trends by sex, age, race/ethnicity, family income to poverty ratio, and obesity status. Total fruit includes whole fruit (all fruit excluding juice) and fruit juice (from 100% juice, foods, and other beverages). Total vegetables include those encouraged in the Dietary Guidelines for Americans, 2010 (i.e., dark green, orange, and red vegetables and legumes), white potatoes, and all other vegetables.

Results

Total fruit intake among children increased from 0.55 CEPC in 2003–2004 to 0.62 in 2009–2010 because of significant increases in whole fruit intake (0.24 to 0.40 CEPC). Over this period, fruit juice intake significantly decreased (0.31 to 0.22 CEPC). Total vegetable intake did not change (0.54 to 0.53 CEPC). No socio-demographic group met the Healthy People 2020 target of 1.1 CEPC vegetables, and only children aged 2–5 years met the target of 0.9 CEPC fruits.

Conclusions

Children’s total fruit intake increased because of increases in whole fruit consumption, but total vegetable intake remained unchanged.

Implications for Public Health Practice

Increased attention to the policies and food environments in multiple settings, including schools, early care and education, and homes might help continue the progress in fruit intake and improve vegetable intake.     

Occupational Exposure to Crystalline Silica at Alberta Work Sites

Although crystalline silica has been recognized as a health hazard for many years, it is still encountered in many work environments. Numerous studies have revealed an association between exposure to respirable crystalline silica and the development of silicosis and other lung diseases including lung cancer. Alberta Jobs, Skills, Training and Labour conducted a project to evaluate exposure to crystalline silica at a total of 40 work sites across 13 industries. Total airborne respirable dust and respirable crystalline silica concentrations were quite variable, but there was a potential to exceed the Alberta Occupational Exposure Limit (OEL) of 0.025 mg/m³ for respirable crystalline silica at many of the work sites evaluated. The industries with the highest potentials for overexposure occurred in sand and mineral processing (GM 0.090 mg/m³), followed by new commercial building construction (GM 0.055 mg/m³), aggregate mining and crushing (GM 0.048 mg/m³), abrasive blasting (GM 0.027 mg/m³), and demolition (GM 0.027 mg/m³). For worker occupations, geometric mean exposure ranged from 0.105 mg/m³ (brick layer/mason/concrete cutting) to 0.008 mg/m³ (dispatcher/shipping, administration). Potential for GM exposure exceeding the OEL was identified in a number of occupations where it was not expected, such as electricians, carpenters and painters. These exposures were generally related to the specific task the worker was doing, or arose from incidental exposure from other activities at the work site. The results indicate that where there is a potential for activities producing airborne respirable crystalline silica, it is critical that the employer include all worker occupations at the work site in their hazard assessment. There appears to be a relationship between airborne total respirable dust concentration and total respirable dust concentrations, but further study is require to fully characterize this relationship. If this relationship holds true, it may provide a useful hazard assessment tool for employers by which the potential for exposure to airborne respirable silica at the work site can be more easily estimated.     

The Effect of Changes in Health Beliefs Among African-American and Rural White Church Congregants Enrolled in an Obesity Intervention: A Qualitative Evaluation

Church interventions can reduce obesity disparities by empowering participants with knowledge and skills within an established community. The purpose of this study was to evaluate the Biomedical/Obesity Reduction Trial (BMORe) and investigate changes in health beliefs among obese adult participants. Ten pre-/post-intervention focus groups applying the Health Belief Model conducted in two African-American churches in Tennessee (n = 20) and South Carolina (n = 20), and one rural Appalachian church in Kentucky (n = 21). Two independent coders using NVivo analyzed transcribed audio data and notes. Participants’ health status of being overweight/obese and having comorbidities of diabetes and high blood pressure motivated enrollment in BMORe. Initially participants voiced low self-efficacy in cooking healthy and reading food labels. BMORe made participants feel “empowered” after 12 weeks compared to initially feeling “out of control” with their weight. Participants reported improvements in emotional health, quality of life, and fewer medications. During post-intervention focus groups, participants reported increased self-efficacy through family support, sharing healthy eating strategies, and having accountability partners. Solidarity and common understanding among BMORe participants led focus group attendees to comment how their peers motivated them to stay in the program for 12 weeks. Long-term barriers include keeping the weight off by maintaining habits of exercise and healthy eating. Implementation of pre-/post-intervention focus groups is an innovative approach to evaluate an obesity intervention and track how changes in health beliefs facilitated behavior change. This novel approach shows promise for behavioral interventions that rely on participant engagement for sustained effectiveness.     

Collaborating toward equity in Pennsylvania: The Age-Friendly Care,PA project

Objective

To collaboratively implement the age-friendly health systems framework, known as the 4Ms: What Matters, Medication, Mentation, and Mobility, at The Primary Health Network (PHN), a federally qualified health center.

Data Sources

Data were collected from PHN electronic medical records (EMRs) for individuals over age 65 from December 30, 2019 to December 24, 2021 and from Project ECHO© attendance and evaluation surveys.

Study Design

The telementoring educational program, Project ECHO©, was used to engage PHN health care professionals working in rural areas of Pennsylvania to incorporate the 4Ms into their practice starting with the annual wellness visit (AWV). Project ECHO© was launched at three primary care sites. After 18 months, it was then disseminated to an additional 18 sites creating pilot and comparison groups. Outcomes included codesigned patient process metrics using EMR data and project ECHO© participant data.

Data Collection Methods

EMR data were generated by system reports created by PHN's quality assurance program manager. Project ECHO© data were collected and managed using REDCap electronic data capture tools. Outcomes were aggregated, analyzed for trends over time, and compared between groups.

Principal Findings

All nine process outcomes increased from baseline to follow-up at the three initial sites, ranging from 4% to 43% g. At year two, the three initial sites had higher rates on AWVs (pilot 24%, comparison 12%; p < 0.0001), Advance Care Planning (New on file, pilot 8%, comparison 2%; Discussed with patient, pilot 18%, comparison 13%; Patient declined, pilot 0%, comparison 0%; p = 0.0001), Dementia Screening (pilot 24%, comparison 12%; p < 0.0001), Fall Risk Management (pilot 43%, comparison 10%; p < 0.0001), and Mobility Goal (pilot 19%, comparison 9%; p < 0.0001); and lower rates on High-Risk Medication Elimination (pilot 54%, comparison, 63%, p < 0.02).

Conclusions

Access to high-quality geriatric care for rural older adults can be improved by increasing health care professionals' knowledge of the 4Ms, beginning with its incorporation into the AWV.     

The social vulnerability metric (SVM) as a new tool for public health

Objective

To derive and validate a new ecological measure of the social determinants of health (SDoH), calculable at the zip code or county level.

Data Sources and Study Setting

The most recent releases of secondary, publicly available data were collected from national U.S. health agencies as well as state and city public health departments.

Study Design

The Social Vulnerability Metric (SVM) was constructed from U.S. zip-code level measures (2018) from survey data using multidimensional Item Response Theory and validated using outcomes including all-cause mortality (2016), COVID-19 vaccination (2021), and emergency department visits for asthma (2018). The SVM was also compared with the existing Centers for Disease Control and Prevention's Social Vulnerability Index (SVI) to determine convergent validity and differential predictive validity.

Data Collection/Extraction Methods

The data were collected directly from published files available to the public online from national U.S. health agencies as well as state and city public health departments.

Principal Findings

The correlation between SVM scores and national age-adjusted county all-cause mortality was r = 0.68. This correlation demonstrated the SVM's robust validity and outperformed the SVI with an almost four-fold increase in explained variance (46% vs. 12%). The SVM was also highly correlated (r ≥ 0.60) to zip-code level health outcomes for the state of California and city of Chicago.

Conclusions

The SVM offers a measurement tool improving upon the performance of existing SDoH composite measures and has broad applicability to public health that may help in directing future policies and interventions. The SVM provides a single measure of SDoH that better quantifies associations with health outcomes.     

Accelerated in vitro release testing of implantable PLGA microsphere/PVA hydrogel composite coatings

Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, accelerated in vitro release testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug release kinetics were investigated under "real-time" and accelerated conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to "real-time" conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order release phase was slightly accelerated. Elevated temperatures resulted in a significant acceleration of dexamethasone release. The accelerated release data were able to predict "real-time" release when applying the Arrhenius equation. Microsphere batches with faster and slower release profiles were investigated under "real-time" and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro release testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems.     

Molecular and functional characterization of the human platelet Na(+) /Ca(2+) exchangers

BACKGROUND AND PURPOSE The Na(+) /Ca(2+) exchanger is a bi-directional transporter that plays an important role in maintaining the concentration of cytosolic Ca(2+) ([Ca(2+) ](i) ) of quiescent platelets and increasing it during activation with some, but not all, agonists. There are two classes of Na(+) /Ca(2+) exchangers: K(+) -independent Na(+) /Ca(2+) exchanger (NCX) and K(+) -dependent Na(+) /Ca(2+) exchanger (NCKX). Platelets have previously been shown to express NCKX1. However, initial studies from our laboratory suggest that NCX may also play a role in platelet activation. The objective of this study was to determine if the human platelet expresses functional NCXs. EXPERIMENTAL APPROACH RT-PCR, DNA sequencing and Western blot analysis were utilized to characterize the human platelet Na(+) /Ca(2+) exchangers. Their function during quiescence and collagen-induced activation was determined by measuring [Ca(2+) ](i) with calcium-green/fura-red in response to: changes in the Na(+) and K(+) gradient, NCX pharmacological inhibitors (CBDMB, KB-R7943 and SEA0400) and antibodies specific to extracellular epitopes of the exchangers. KEY RESULTS Human platelets express NCX1.3, NCX3.2 and NCX3.4. The NCXs operate in the Ca(2+) efflux mode in resting platelets and also during their activation with thrombin but not collagen. Collagen-induced increase in [Ca(2+) ](i) was reduced with the pharmacological inhibitors of NCX (CBDMB, KB-R7943 or SEA0400), anti-NCX1 and anti-NCX3. In contrast, anti-NCKX1 enhanced the collagen-induced increase in [Ca(2+) ](i) . CONCLUSIONS AND IMPLICATIONS Human platelets express K(+) -independent Na(+) /Ca(2+) exchangers NCX1.3, NCX3.2 and NCX3.4. During collagen activation, NCX1 and NCX3 transiently reverse to promote Ca(2+) influx, whereas NCKX1 continues to operate in the Ca(2+) efflux mode to reduce [Ca(2+) ](i) .     

Application of quality by design to formulation and processing of protein liposomes

Quality by design (QbD) principles were explored in the current study to gain a comprehensive understanding of the preparation of superoxide dismutase (SOD) containing liposome formulations prepared using freeze-and-thaw unilamellar vesicles (FAT-ULV). Risk analysis and D-optimal statistical design were performed. Of all the variables investigated, lipid concentration, cholesterol mol%, main lipid type and protein concentration were identified as critical parameters affecting SOD encapsulation efficiency, while the main lipid type was the only factor influencing liposome particle size. Using a model generated by the D-optimal design, a series of three-dimensional response spaces for SOD liposome encapsulation efficiency were established. The maximum values observed in the response surfaces indirectly confirmed the existence of a specific SOD-lipid interaction, which took place in the lipid bilayer under the following optimal conditions: (1) appropriate membrane thickness and curvature (DPPC liposomes); and (2) optimal "pocket size" generated by cholesterol content. With respect to storage stability, the prepared SOD liposomes remained stable for at least 6 months in aqueous dispersion state at 4°C. This research highlights the level of understanding that can be accomplished through a well-designed study based on the philosophy of QbD.     

Predictors of attrition with buprenorphine/naloxone treatment in opioid dependent youth

Background

In opioid dependent youth there is substantial attrition from medication-assisted treatment. If youth at risk for attrition can be identified at treatment entry or early in treatment, they can be targeted for interventions to help retain them in treatment.

Methods

Opioid dependent adolescents and young adults (n = 152), aged 15–21, were randomized to 12 weeks (BUP, n = 74) or 2 weeks of detoxification (DETOX, n = 78) with buprenorphine/naloxone (Bup/Nal), both in combination with 12 weeks of psychosocial treatment. Baseline and early treatment related predictors of treatment attrition were identified in each group using bivariate and multivariate logistic regression.

Results

In the DETOX group 36% left between weeks 2 and 4, at the end of the dose taper, while in the BUP group only 8% left by week 4. In the BUP group, early adherence to Bup/Nal, early opioid negative urines, use of any medications in the month prior to treatment entry, and lifetime non-heroin opioid use were associated with retention while prior 30-day hallucinogen use was associated with attrition. In the DETOX group, only use of sleep medications was associated with retention although not an independent predictor. A broad range of other pre-treatment characteristics was unrelated to attrition.

Conclusions

Prompt attention to those with early non-adherence to medication or an early opioid positive urine, markers available in the first 2 weeks of treatment, may improve treatment retention. Extended Bup/Nal treatment appeared effective in improving treatment retention for youth with opioid dependence across a wide range of demographics, and pre-treatment clinical characteristics.