Skeletal Muscle Bioenergetics in Critical Limb Ischemia and Diabetes.

INTRODUCTION: Mitochondrial dysfunction is implicated in the metabolic myopathy accompanying peripheral artery disease (PAD) and critical limb ischemia (CLI). Type-2 diabetes mellitus (T2DM) is a major risk factor for PAD development and progression to CLI and may also independently be related to mitochondrial dysfunction. We set out to determine the effect of T2DM in the relationship between CLI and muscle mitochondrial respiratory capacity and coupling control. METHODS: We studied CLI patients undergoing revascularization procedures or amputation, and non-CLI patients with or without T2DM of similar age. Mitochondrial respiratory capacity and function were determined in lower limb permeabilized myofibers by high-resolution respirometry. RESULTS: Fourteen CLI patients (65 ± 10y) were stratified into CLI patients with (n = 8) or without (n = 6) T2DM and were compared to non-CLI patients with (n = 18; 69 ± 5y) or without (n = 19; 71 ± 6y) T2DM. Presence of CLI but not T2DM had a marked impact on all mitochondrial respiratory states in skeletal muscle, adjusted for the effects of sex. Leak respiration (State 2, P < 0.025 and State 4o, P < 0.01), phosphorylating respiration (P < 0.001), and maximal respiration in the uncoupled state (P < 0.001), were all suppressed in CLI patients, independent of T2DM. T2DM had no significant effect on mitochondrial respiratory capacity and function in adults without CLI. CONCLUSIONS: Skeletal muscle mitochondrial respiratory capacity was blunted by ∼35% in patients with CLI. T2DM was not associated with muscle oxidative capacity and did not moderate the relationship between muscle mitochondrial respiratory capacity and CLI.

Development of spirulina for the manufacture and oral delivery of protein therapeutics.

The use of the edible photosynthetic cyanobacterium Arthrospira platensis (spirulina) as a biomanufacturing platform has been limited by a lack of genetic tools. Here we report genetic engineering methods for stable, high-level expression of bioactive proteins in spirulina, including large-scale, indoor cultivation and downstream processing methods. Following targeted integration of exogenous genes into the spirulina chromosome (chr), encoded protein biopharmaceuticals can represent as much as 15% of total biomass, require no purification before oral delivery and are stable without refrigeration and protected during gastric transit when encapsulated within dry spirulina. Oral delivery of a spirulina-expressed antibody targeting campylobacter-a major cause of infant mortality in the developing world-prevents disease in mice, and a phase 1 clinical trial demonstrated safety for human administration. Spirulina provides an advantageous system for the manufacture of orally delivered therapeutic proteins by combining the safety of a food-based production host with the accessible genetic manipulation and high productivity of microbial platforms.

Parsonage-Turner Syndrome After SARS-CoV-2 BNT162b2 Vaccine: A Case Report.

CASE: Parsonage-Turner syndrome, also known as brachial neuritis or neuralgic amyotrophy, is characterized by sudden-onset pain and subsequent weakness of the shoulder. Known precipitating factors include viral and bacterial infections and certain immunizations. Isolated cases after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported. We report the case of a 66-year-old woman with right shoulder dysfunction and medial scapular winging after immunization with the SARS-CoV-2 BNT162b2 vaccine (Pfizer). CONCLUSION: After physical therapy, the patient resumed her normal activities of daily living. Findings from this case represent the first known documentation of Parsonage-Turner syndrome after SARS-CoV-2 BNT162b2 vaccination.

Rapid Emergency Department Physical Space Modifications for COVID-19: Keeping Patients and Health Care Workers Safe.

The COVID-19 pandemic has placed significant strain on emergency departments (EDs) that were not designed to care for many patients who may be highly contagious. This report outlines how a busy urban ED was adapted to prepare for COVID-19 via 3 primary interventions: (1) creating an open-air care space in the ambulance bay to cohort, triage, and rapidly test patients with suspected COVID-19, (2) quickly constructing temporary doors on all open treatment rooms, and (3) adapting and expanding the waiting room. This description serves as a model by which other EDs can repurpose their own care spaces to help ensure safety of their patients and health care workers.

Effect of essential amino acid supplementation and aerobic exercise on insulin sensitivity in healthy older adults: A randomized clinical trial.

BACKGROUND & AIMS: The combination of prolonged essential amino acid (EAA) supplementation and aerobic exercise training (Ex) improves muscle protein metabolism, strength and function in healthy older adults. However, excess EAA intake may worsen insulin sensitivity. Here we report the effects of EAA supplementation (EAA, n = 11), placebo (PLA, n = 10), aerobic exercise with placebo (Ex + PLA, n = 11) or Ex with EAA supplementation (Ex + EAA, n = 10) for 22 weeks on insulin sensitivity in non-diabetic older adults. METHODS: A 2 × 2 design with block randomization and double blinding for supplement or placebo was used. Subjects ingested EAA (15 g) or placebo daily. Exercising subjects participated in supervised progressive vigorous treadmill walking 3 times weekly. Measures of insulin sensitivity by oral glucose tolerance testing were collected at baseline and 22 weeks. Dietary intakes of protein and specific amino acids were determined in a subset of subjects. RESULTS: Overall, exercise improved insulin sensitivity, while EAA supplementation had no effect. In the dietary subset, post-intervention insulin sensitivity did not correlate significantly with the total intake of EAA, anti-angiogenic amino acids (cysteine, methionine), or branched-chain amino acids (isoleucine, leucine, valine). CONCLUSIONS: Overall, we conclude that in healthy older adults with moderate protein intake, EAA supplementation is metabolically safe as it does not decrease insulin sensitivity regardless of its combination with aerobic exercise. Thus, daily protein intake should be controlled for when modeling insulin sensitivity. Future studies should explore the role of increased blood flow as a potential explanatory factor for the observed interaction between aerobic exercise and supplementation. CLINICAL TRIAL REGISTRATION NUMBER: NCT00872911.

Tricyclic Antidepressant and/or γ-Aminobutyric Acid-Analog Use Is Associated With Fall Risk in Diabetic Peripheral Neuropathy.

BACKGROUND/OBJECTIVES: Peripheral neuropathy is a common diabetes complication that can increase fall risk. Regarding fall risk, the impact of pain management using tricyclic antidepressants (TCAs) or γ-aminobutyric acid (GABA) analogs is unclear because these medications can also cause falls. This study investigates the impact of these drugs on fall and fracture risk in older diabetic peripheral neuropathy (DPN) patients. DESIGN: Historical cohort study with 1-to-1 propensity matching of TCA/GABA-analog users and nonusers. SETTING: Nationally representative 5% Medicare sample between the years 2008 and 2010. PARTICIPANTS: After applying all selection criteria, 5,550 patients with prescription and 22,200 patients without prescription of TCAs/GABA-analogs were identified. Both patient groups were then stratified for fall history and matched based on propensity of receiving TCAs/GABA-analogs within each group. MEASUREMENTS: Patients were followed until the first incidence of fall or the first incidence of fracture during the follow-up period (for up to 5 years). RESULTS: After matching, users and nonusers were largely similar. After covariate adjustment, TCA/GABA-analog use was associated with a statistically significant increase in fall risk (adjusted hazard ratio [HR] = 1.11; 95% confidence interval [CI] = 1.03-1.20), but was not associated with fracture risk (adjusted HR = 1.09; 95% CI = 0.99-1.19) in the conventional analysis. Treating TCA/GABA-analog use as a time-dependent covariate resulted in statistically significant associations of TCA/GABA-analog use with both fall and fracture risk (HR = 1.26 [95% CI = 1.17-1.36]; and HR = 1.12 [95% CI = 1.02-1.24], respectively). CONCLUSION: Among older patients with DPN, GABA-analogs or TCAs increase fall risk and possibly fracture risk. Use of these medications is therefore a potentially modifiable risk factor for falls and fractures in this population.

Effect of Aerobic Exercise Training and Essential Amino Acid Supplementation for 24 Weeks on Physical Function, Body Composition, and Muscle Metabolism in Healthy, Independent Older Adults: A Randomized Clinical Trial.

BACKGROUND: Essential amino acids (EAA) and aerobic exercise (AE) acutely and independently stimulate skeletal muscle protein anabolism in older adults. OBJECTIVE: In this Phase 1, double-blind, placebo-controlled, randomized clinical trial, we determined if chronic EAA supplementation, AE training, or a combination of the two interventions could improve muscle mass and function by stimulating muscle protein synthesis. METHODS: We phone-screened 971, enrolled 109, and randomized 50 independent, low-active, nonfrail, and nondiabetic older adults (age 72 ± 1 years). We used a 2 × 2 factorial design. The interventions were: daily nutritional supplementation (15 g EAA or placebo) and physical activity (supervised AE training 3 days/week or monitored habitual activity) for 24 weeks. Muscle strength, physical function, body composition, and muscle protein synthesis were measured before and after the 24-week intervention. RESULTS: Forty-five subjects completed the 24-week intervention. VO2peak and walking speed increased (p < .05) in both AE groups, irrespective of supplementation type, but muscle strength increased only in the EAA + AE group (p < .05). EAA supplementation acutely increased (p < .05) muscle protein synthesis from basal both before and after the intervention, with a larger increase in the EAA + AE group after the intervention. Total and regional lean body mass did not change significantly with any intervention. CONCLUSIONS: In nonfrail, independent, healthy older adults AE training increased walking speed and aerobic fitness, and, when combined with EAA supplementation, it also increased muscle strength and EAA-stimulated muscle protein synthesis. These increases occurred without improvements in muscle mass.

Patellar tendon reconstruction using an extended gastrocnemius flap following cryogenic injury to the knee.

Cryogenic thermal necrosis after knee surgery is rare. We describe a patient who presented with an anterior knee soft tissue defect in conjunction with an extensor mechanism deficiency secondary to a cold thermal injury after an anterior cruciate ligament reconstruction. We treated the patient with a single stage surgical procedure combining patellar tendon reconstruction and soft tissue coverage utilizing the superficial portion of the patient's vascularized Achilles tendon attached to a medial gastrocnemius flap. The patient returned to unrestricted activities and has demonstrated this through a five year follow-up.

Plasma protein biomarkers of the geriatric syndrome of frailty.

Frailty is a geriatric syndrome associated with physical decline with aging. Using a proteomics-based screening method to screen plasma for potential biomarkers, we previously found inflammatory glycoproteins to be increased with frailty. The purpose of this study was to confirm if plasma levels of these glycoproteins, as well as of interleukin-6, are increased with frailty in a larger sample (n = 65) of community-dwelling older adults. Plasma levels of transferrin, fibrinogen, haptoglobin, and interleukin-6 were determined with enzyme-linked immunosorbent assay. Differences in protein concentrations by frailty status were determined using analysis of variance. Higher levels of transferrin (p < .001), fibrinogen (p < .0001), and interleukin-6 (p = .0035) were associated with frailty status (nonfrail, prefrail, or frail) and frailty score (0-5) in this sample even after adjustment for age and sex. Haptoglobin did not differ by frailty status (p = .05). Our findings largely confirmed the findings of our nontargeted approach that inflammatory glycoproteins are increased with frailty. Future studies should include larger examinations of these associations and consider the potential usefulness of these glycoproteins as biomarkers for frailty.

Tris(3,5-di-tert-butylcatecholato)molybdenum(VI): Lewis acidity and nonclassical oxygen atom transfer reactions.

In the solid state, tris(3,5-di-tert-butylcatecholato)molybdenum(VI) forms a dimer with seven-coordinate molybdenum and bridging catecholates. NMR spectroscopy indicates that the dimeric structure is retained in solution. The molybdenum center has a high affinity for Lewis bases such as pyridine or pyridine-N-oxide, forming seven-coordinate monomers with a capped octahedral geometry, as illustrated by the solid-state structure of (3,5-(t)Bu2Cat)3Mo(py). Structural data indicate that the complexes are best considered as Mo(VI) with substantial π donation from the nonbridging catecholates to molybdenum. Both the dimeric and the monomeric tris(catecholates) react rapidly with water to form free catechol and oxomolybdenum bis(catecholate) complexes. Monooxomolybdenum complexes are also obtained, more slowly, on reaction with dioxygen, with organic products consisting mostly of 3,5-di-tert-butyl-1,2-benzoquinone with minor amounts of the extradiol oxidation product 4,6-di-tert-butyl-1-oxacyclohepta-4,6-diene-2,3-dione. The pyridine-N-oxide complex reacts on heating (with excess pyO) to form initially (3,5-(t)Bu2Cat)2MoO(Opy) and ultimately MoO3(Opy), with quinone and free pyridine as the only organic products. The decay of (3,5-(t)Bu2Cat)3Mo(Opy) shows an accelerated, autocatalytic profile because the oxidation of its product, (3,5-(t)Bu2Cat)2MoO(Opy), produces an oxo-rich, catecholate-poor intermediate which rapidly conproportionates with (3,5-(t)Bu2Cat)3Mo(Opy), providing an additional pathway for its conversion to the mono-oxo product. The tris(catecholate) fragment Mo(3,5-(t)Bu2Cat)3 deoxygenates Opy in this nonclassical oxygen atom transfer reaction slightly less rapidly than does its oxidized product, MoO(3,5-(t)Bu2Cat)2.