Restricted physical activity after volumetric muscle loss alters whole-body and local muscle metabolism.

Volumetric muscle loss (VML) is the traumatic loss of skeletal muscle, resulting in chronic functional deficits and pathological comorbidities, including altered whole-body metabolic rate and respiratory exchange ratio (RER), despite no change in physical activity in animal models. In other injury models, treatment with ß2 receptor agonists (e.g. formoterol) improves metabolic and skeletal muscle function. We aimed first to examine if restricting physical activity following injury affects metabolic and skeletal muscle function, and second, to enhance the metabolic and contractile function of the muscle remaining following VML injury through treatment with formoterol. Adult male C57Bl/6J mice (n = 32) underwent VML injury to the posterior hindlimb compartment and were randomly assigned to unrestricted or restricted activity and formoterol treatment or no treatment; age-matched injury naïve mice (n = 4) were controls for biochemical analyses. Longitudinal 24 h evaluations of physical activity and whole-body metabolism were conducted following VML. In vivo muscle function was assessed terminally, and muscles were biochemically evaluated for protein expression, mitochondrial enzyme activity and untargeted metabolomics. Restricting activity chronically after VML had the greatest effect on physical activity and RER, reflected in reduced lipid oxidation, although changes were attenuated by formoterol treatment. Formoterol enhanced injured muscle mass, while mitigating functional deficits. These novel findings indicate physical activity restriction may recapitulate following VML clinically, and adjunctive oxidative treatment may create a metabolically beneficial intramuscular environment while enhancing the injured muscle's mass and force-producing capacity. Further investigation is needed to evaluate adjunctive oxidative treatment with rehabilitation, which may augment the muscle's regenerative and functional capacity following VML. KEY POINTS: The natural ability of skeletal muscle to regenerate and recover function is lost following complex traumatic musculoskeletal injury, such as volumetric muscle loss (VML), and physical inactivity following VML may incur additional deleterious consequences for muscle and metabolic health. Modelling VML injury-induced physical activity restriction altered whole-body metabolism, primarily by decreasing lipid oxidation, while preserving local skeletal muscle metabolic activity. The ß2 adrenergic receptor agonist formoterol has shown promise in other severe injury models to improve regeneration, recover function and enhance metabolism. Treatment with formoterol enhanced mass of the injured muscle and whole-body metabolism while mitigating functional deficits resulting from injury. Understanding of chronic effects of the clinically available and FDA-approved pharmaceutical formoterol could be a translational option to support muscle function after VML injury.

Resistance wheel running improves contractile strength, but not metabolic capacity, in a murine model of volumetric muscle loss injury.

The primary objective of this study was to determine if low- or high-resistance voluntary wheel running leads to functional improvements in muscle strength (i.e., isometric and isokinetic torque) and metabolic function (i.e., permeabilized fibre bundle mitochondrial respiration) after a volumetric muscle loss (VML) injury. C57BL/6J mice were randomized into one of four experimental groups at age 12 weeks: uninjured control, VML untreated (VML), low-resistance wheel running (VML-LR) and high-resistance wheel running (VML-HR). All mice, excluding the uninjured, were subject to a unilateral VML injury to the plantar flexor muscles and wheel running began 3 days post-VML. At 8 weeks post-VML, peak isometric torque was greater in uninjured compared to all VML-injured groups, but both VML-LR and VML-HR had greater (∼32%) peak isometric torque compared to VML. All VML-injured groups had less isokinetic torque compared to uninjured, and there was no statistical difference among VML, VML-LR and VML-HR. No differences in cumulative running distance were observed between VML-LR and VML-HR groups. Because adaptations in VML-HR peak isometric torque were attributed to greater gastrocnemius muscle mass, atrophy- and hypertrophy-related protein content and post-translational modifications were explored via immunoblot; however, results were inconclusive. Permeabilized fibre bundle mitochondrial oxygen consumption was 22% greater in uninjured compared to VML, but there was no statistical difference among VML, VML-LR and VML-HR. Furthermore, neither wheel running group demonstrated a change in the relative protein content of the mitochondrial biogenesis transcription factor, peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α). These results indicate that resistance wheel running alone only has modest benefits in the VML-injured muscle. NEW FINDINGS: What is the central question of the study? Does initiation of a resistance wheel running regimen following volumetric muscle loss (VML) improve the functional capacity of skeletal muscle? What is the main finding and its importance? Resistance wheel running led to greater muscle mass and strength in mice with a VML injury but did not result in a full recovery. Neither low- nor high-resistance wheel running was associated with a change in permeabilized muscle fibre respiration despite runners having greater whole-body treadmill endurance capacity, suggesting resilience to metabolic adaptations in VML-injured muscle. Resistance wheel running may be a suitable adjuvant rehabilitation strategy, but alone does not fully mitigate VML pathology.

Compromised Muscle Properties in a Severe Hypophosphatasia Murine Model.

Hypophosphatasia (HPP) is a rare metabolic bone disorder characterized by low levels of tissue non-specific alkaline phosphatase (TNAP) that causes under-mineralization of the bone, leading to bone deformity and fractures. In addition, patients often present with chronic muscle pain, reduced muscle strength, and an altered gait. In this work, we explored dynamic muscle function in a homozygous TNAP knockout mouse model of severe juvenile onset HPP. We found a reduction in skeletal muscle size and impairment in a range of isolated muscle contractile properties. Using histological methods, we found that the structure of HPP muscles was similar to healthy muscles in fiber size, actin and myosin structures, as well as the α-tubulin and mitochondria networks. However, HPP mice had significantly fewer embryonic and type I fibers than wild type mice, and fewer metabolically active NADH+ muscle fibers. We then used oxygen respirometry to evaluate mitochondrial function and found that complex I and complex II leak respiration were reduced in HPP mice, but that there was no disruption in efficiency of electron transport in complex I or complex II. In summary, the severe HPP mouse model recapitulates the muscle strength impairment phenotypes observed in human patients. Further exploration of the role of alkaline phosphatase in skeletal muscle could provide insight into mechanisms of muscle weakness in HPP.

Lifelong Ulk1-Mediated Autophagy Deficiency in Muscle Induces Mitochondrial Dysfunction and Contractile Weakness.

The accumulation of damaged mitochondria due to insufficient autophagy has been implicated in the pathophysiology of skeletal muscle aging. Ulk1 is an autophagy-related kinase that initiates autophagosome assembly and may also play a role in autophagosome degradation (i.e., autophagy flux), but the contribution of Ulk1 to healthy muscle aging is unclear. Therefore, the purpose of this study was to investigate the role of Ulk1-mediated autophagy in skeletal muscle aging. At age 22 months (80% survival rate), muscle contractile and metabolic function were assessed using electrophysiology in muscle-specific Ulk1 knockout mice (MKO) and their littermate controls (LM). Specific peak-isometric torque of the ankle dorsiflexors (normalized by tibialis anterior muscle cross-sectional area) and specific force of the fast-twitch extensor digitorum longus muscles was reduced in MKO mice compared to LM mice (p < 0.03). Permeabilized muscle fibers from MKO mice had greater mitochondrial content, yet lower mitochondrial oxygen consumption and greater reactive oxygen species production compared to fibers from LM mice (p ≤ 0.04). Alterations in neuromuscular junction innervation patterns as well as changes to autophagosome assembly and flux were explored as possible contributors to the pathological features in Ulk1 deficiency. Of primary interest, we found that Ulk1 phosphorylation (activation) to total Ulk1 protein content was reduced in older muscles compared to young muscles from both human and mouse, which may contribute to decreased autophagy flux and an accumulation of dysfunctional mitochondria. Results from this study support the role of Ulk1-mediated autophagy in aging skeletal muscle, reflecting Ulk1's dual role in maintaining mitochondrial integrity through autophagosome assembly and degradation.

Timing of shoot development transitions affects degree of perenniality in Arabidopsis lyrata (Brassicaceae).

BACKGROUND: Perenniality is best understood in quantitative terms, involving the relationship between production vs. turnover of meristems, biomass, or energy reserves. Previous quantitative trait locus (QTL) studies using divergent populations of the perennial rock cress Arabidopsis lyrata have shown that trade-offs in vegetative growth vs. reproduction are due to cascading effects of differences in early vegetative development, which contribute to local adaptation. However, details of the developmental differences and how they affect perenniality remained unclear. In this study, we investigated in detail the developmental differences in perenniality between populations. A. lyrata from Norway and North Carolina populations, representing contrasting environments and degrees of perenniality, were grown under controlled conditions, and data were collected on plant phenology and shoot-level development. We tested hypotheses that differences in perenniality involve strict allocation of lateral meristems to vegetative vs. reproductive fates, or alternatively quantitative effects of pre-reproductive vegetative development. RESULTS: The two populations showed large differences in the degree of vegetative development on individual shoots prior to reproductive transitions. The number of leaves produced on shoots prior to bolting, and not strict meristem allocation or variation in apical dominance, was able to explain variation in the number of inflorescences on individual plants. These results suggested that allocation of time to shoot vegetative vs. reproductive development could be a major factor in resource allocation differences between the populations. CONCLUSIONS: Based on these results and those of previous QTL studies, we propose a model in which the degree of shoot vegetative development shapes the developmental context for reproduction and subsequent vegetative growth in different environments. Climate-specific effects of shoot development patterns on reproductive output and survival may result in divergent evolutionary trajectories along a perenniality continuum, which may have broader relevance for plant life history evolution.

The bioenergetic "CK Clamp" technique detects substrate-specific changes in mitochondrial respiration and membrane potential during early VML injury pathology.

Volumetric muscle loss (VML) injuries are characterized by non-recoverable loss of tissue resulting in contractile and metabolic dysfunction. The characterization of metabolic dysfunction in volumetric muscle loss-injured muscle has been interpreted from permeabilized myofiber respiration experiments involving saturating ADP levels and non-physiologic ATP:ADP concentration ratios. The extent to which this testing condition obscures the analysis of mitochondrial (dys) function after volumetric muscle loss injury is unclear. An alternative approach is described that leverages the enzymatic reaction of creatine kinase and phosphocreatine to assess mitochondrial respiration and membrane potential at clamped physiologic ATP:ADP ratios, "CK Clamp." The objective of this study was to validate the CK Clamp in volumetric muscle loss-injured muscle and to detect differences that may exist between volumetric muscle loss-injured and uninjured muscles at 1, 3, 5, 7, 10, and 14 days post-injury. Volumetric muscle loss-injured muscle maintains bioenergetic features of the CK Clamp approach, i.e., mitochondrial respiration rate (JO2) titters down and mitochondrial membrane potential is more polarized with increasing ATP:ADP ratios. Pyruvate/malate/succinate-supported JO2 was significantly less in volumetric muscle loss-injured muscle at all timepoints compared to uninjured controls (-26% to -84%, p < 0.001) and electron conductance was less at day 1 (-60%), 5 (-52%), 7 (-35%), 10 (-59%), and 14 (-41%) (p < 0.001). Palmitoyl-carnitine/malate-supported JO2 and electron conductance were less affected following volumetric muscle loss injury. volumetric muscle loss-injury also corresponded with a more polarized mitochondrial membrane potential across the clamped ATP:ADP ratios at day 1 and 10 (pyruvate and palmitoyl-carnitine, respectively) (+5%, p < 0.001). This study supports previous characterizations of metabolic dysfunction and validates the CK Clamp as a tool to investigate bioenergetics in traumatically-injured muscle.

Differential effects of Western diet and traumatic muscle injury on skeletal muscle metabolic regulation in male and female mice.

BACKGROUND: This study was designed to develop an understanding of the pathophysiology of traumatic muscle injury in the context of Western diet (WD; high fat and high sugar) and obesity. The objective was to interrogate the combination of WD and injury on skeletal muscle mass and contractile and metabolic function. METHODS: Male and female C57BL/6J mice were randomized into four groups based on a two-factor study design: (1) injury (uninjured vs. volumetric muscle loss [VML]) and (2) diet (WD vs. normal chow [NC]). Electrophysiology was used to test muscle strength and metabolic function in cohorts of uninjured + NC, uninjured + WD, VML + NC and VML + WD at 8 weeks of intervention. RESULTS: VML-injured male and female mice both exhibited decrements in muscle mass (-17%, P < 0.001) and muscle strength (-28%, P < 0.001); however, VML + WD females had a 28% greater muscle mass compared to VML + NC females (P = 0.034), a compensatory response not detected in males. VML-injured male and female mice both had lower carbohydrate- and fat-supported muscle mitochondrial respiration (JO2 ) and less electron conductance through the electron transport system (ETS); however, male VML-WD had 48% lower carbohydrate-supported JO2 (P = 0.014) and 47% less carbohydrate-supported electron conductance (P = 0.026) compared to male VML + NC, and this diet-injury phenotype was not present in females. ETS electron conductance starts with complex I and complex II dehydrogenase enzymes at the inner mitochondrial membrane, and male VML + WD had 31% less complex I activity (P = 0.004) and 43% less complex II activity (P = 0.005) compared to male VML + NC. This was a diet-injury phenotype not present in females. Pyruvate dehydrogenase (PDH), ß-hydroxyacyl-CoA dehydrogenase, citrate synthase, α-ketoglutarate dehydrogenase and malate dehydrogenase metabolic enzyme activities were evaluated as potential drivers of impaired JO2 in the context of diet and injury. There were notable male and female differential effects in the enzyme activity and post-translational regulation of PDH. PDH enzyme activity was 24% less in VML-injured males, independent of diet (P < 0.001), but PDH enzyme activity was not influenced by injury in females. PDH enzyme activity is inhibited by phosphorylation at serine-293 by PDH kinase 4 (PDK4). In males, there was greater total PDH, phospho-PDHser293 and phospho-PDH-to-total PDH ratio in WD mice compared to NC, independent of injury (P ≤ 0.041). In females, PDK4 was 51% greater in WD compared to NC, independent of injury (P = 0.025), and was complemented by greater phospho-PDHser293 (P = 0.001). CONCLUSIONS: Males are more susceptible to muscle metabolic dysfunction in the context of combined WD and traumatic injury compared to females, and this may be due to impaired metabolic enzyme functions.

Using a Socio-Ecological Framework to Understand Romantic Relationship Satisfaction Among Emerging Adults During the COVID-19 Pandemic.

The formation and maintenance of satisfying romantic relationships, a developmental milestone for many emerging adults, has been challenged by the negative impact of the COVID-19 pandemic. Yet, the impact of COVID-19 stress on relationship satisfaction has not been explored within the context of individual and relationship factors. Guided by a socio-ecological framework, this study used a longitudinal design to investigate the impact of individual-level (i.e., growth beliefs, destiny beliefs), couple-level (i.e., daily criticism), and societal-level (i.e., COVID-19 stress) factors on relationship satisfaction during Fall 2021. We also explored the moderating effects of destiny beliefs and growth beliefs. Results revealed relationship satisfaction was negatively associated with daily criticism, but not directly associated with destiny beliefs, growth beliefs, or COVID-19 stress. However, growth beliefs buffered against the negative impact of criticism on relationship satisfaction. These findings are consistent with the notion that growth beliefs may play a protective role in relationship processes.

Pharmaceutical Agents for Contractile-Metabolic Dysfunction After Volumetric Muscle Loss.

Volumetric muscle loss (VML) injuries represent a majority of military service member casualties and are common in civilian populations following blunt and/or penetrating traumas. Characterized as a skeletal muscle injury with permanent functional impairments, there is currently no standard for rehabilitation, leading to lifelong disability. Toward developing rehabilitative strategies, previous research demonstrates that the remaining muscle after a VML injury lacks similar levels of plasticity or adaptability as healthy, uninjured skeletal muscle. This may be due, in part, to impaired innervation and vascularization of the remaining muscle, as well as disrupted molecular signaling cascades commonly associated with muscle adaptation. The primary objective of this study was to assess the ability of four pharmacological agents with a strong record of modulating muscle contractile and metabolic function to improve functional deficits in a murine model of VML injury. Male C57BL/6 mice underwent a 15% multimuscle VML injury of the posterior hindlimb and were randomized into drug treatment groups (formoterol [FOR], 5-aminoimidazole-4-carboxamide riboside [AICAR], pioglitazone [PIO], or sildenafil [SIL]) or untreated VML group. At the end of 60 days, the injury model was first validated by comparison to age-matched injury-naive mice. Untreated VML mice had 22% less gastrocnemius muscle mass, 36% less peak-isometric torque, and 27% less maximal mitochondrial oxygen consumption rate compared to uninjured mice (p < 0.01). Experimental drug groups were, then, compared to VML untreated, and there was minimal evidence of efficacy for AICAR, PIO, or SIL in improving contractile and metabolic functional outcomes. However, FOR-treated VML mice had 18% greater peak isometric torque (p < 0.01) and permeabilized muscle fibers had 36% greater State III mitochondrial oxygen consumption rate (p < 0.01) compared to VML untreated mice, suggesting an overall improvement in muscle condition. There was minimal evidence that these benefits came from greater mitochondrial biogenesis and/or mitochondrial complex protein content, but could be due to greater enzyme activity levels for complex I and complex II. These findings suggest that FOR treatment is candidate to pair with a rehabilitative approach to maximize functional improvements in VML-injured muscle. Impact statement Volumetric muscle loss (VML) injuries result in deficiencies in strength and mobility, which have a severe impact on patient quality of life. Despite breakthroughs in tissue engineering, there are currently no treatments available that can restore function to the affected limb. Our data show that treatment of VML injuries with clinically available and FDA-approved formoterol (FOR), a beta-agonist, significantly improves strength and metabolism of VML-injured muscle. FOR is therefore a promising candidate for combined therapeutic approaches (i.e., regenerative rehabilitation) such as pairing FOR with structured rehabilitation or cell-seeded biomaterials as it may provide greater functional improvements than either strategy alone.

Independent of physical activity, volumetric muscle loss injury in a murine model impairs whole-body metabolism.

Volumetric muscle loss (VML) injuries result in a non-recoverable loss of muscle tissue and function due to trauma or surgery. Reductions in physical activity increase the risk of metabolic comorbidities over time, and it is likely that VML may reduce whole-body activity. However, these aspects remain uncharacterized following injury. Our goal was to characterize the impact of VML on whole-body physical activity and metabolism, and to further investigate possible muscle-specific metabolic changes. Adult male C57Bl/6J (n = 28) mice underwent a standardized VML injury to the posterior compartment of the hind limb, or served as injury naïve controls. Mice underwent longitudinal evaluation of whole-body physical activity and metabolism in specialized cages up to three times over the course of 8 weeks. At terminal time points of 4- and 8-weeks post-VML in vivo muscle function of the posterior compartment was evaluated. Additionally, the gastrocnemius muscle was collected to understand histological and biochemical changes in the muscle remaining after VML. The VML injury did not alter the physical activity of mice. However, there was a noted reduction in whole-body metabolism and diurnal fluctuations between lipid and carbohydrate oxidation were also reduced, largely driven by lower carbohydrate utilization during active hours. Following VML, muscle-specific changes indicate a decreased proportion of fast (i.e., type IIb and IIx) and a greater proportion of slow (i.e., type I and IIa) fibers. However, there were minimal changes in the capillarity and metabolic biochemical activity properties of the gastrocnemius muscle, suggesting a miss-match in capacity to support the physiologic needs of the fibers. These novel findings indicate that following VML, independent of changes in physical activity, there is whole-body diurnal metabolic inflexibility. Supporting future investigations into the chronic and overlooked co-morbidities of VML injury.

Full-thickness rotator cuff tear in rat results in distinct temporal expression of multiple proteases in tendon, muscle, and cartilage.

The etiology of joint tissue degeneration following rotator cuff tear remains unclear. Thus, the purpose of this study was to understand the timeline of protease activity in the soft tissues of the shoulder (tendon, muscle, and cartilage) that may lead to down-stream degeneration following rotator cuff tear. A well-established rat model involving suprascapular nerve denervation and supraspinatus/infraspinatus tendon transection was employed. Histological staining and/or micro-computed tomography (µCT) were used to observe structural damage in the supraspinatus tendon and muscle, humeral head cartilage, and subchondral bone. Multiplex gelatin zymography was utilized to assess protease activity in the supraspinatus tendon and muscle, and humeral head cartilage. Zymography analysis demonstrated that cathepsins were upregulated in the first week in all tissues, while MMP-2 maintained prolonged activity in supraspinatus tendon between 1 and 3 weeks and increased only at 3 weeks in supraspinatus muscle. In supraspinatus tendon, increased cathepsin L and MMP-2 activity in the first week was concurrent with matrix disorganization and infiltration of inflammatory cells. In contrast, significant upregulation of cathepsin L and K activity in supraspinatus muscle and humeral head cartilage did not correspond to any visible tissue damage at 1 week. However, focal defects developed in half of all animals' humeral head cartilage by 12 weeks (volume: 0.12 ± 0.09 mm3 ). This work provides a more comprehensive understanding of biochemical changes to joint tissue over time following rotator cuff tear. Overall, this provides insight into potential therapeutic targets and will better inform ideal intervention times and treatments for each tissue. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:490-502, 2019.

Dual Affinity Heparin-Based Hydrogels Achieve Pro-Regenerative Immunomodulation and Microvascular Remodeling.

The immune response to biomaterial implants critically regulates functional outcomes such as vascularization, transplant integration/survival, and fibrosis. To create "immunologically smart" materials, the host-material response may be engineered to optimize the recruitment of pro-regenerative leukocyte subsets which mature into corresponding wound-healing macrophages. We have recently identified a unique feature of pro-regenerative Ly6Clow monocytes that is a higher expression of both the bioactive lipid receptor sphingosine-1-phosphate receptor 3 (S1PR3) and the stromal derived factor-1α (SDF-1α) receptor CXCR4. Therefore, we designed a bifunctional hydrogel to harnesses a mechanistic synergy between these signaling axes to enhance the recruitment of endogenous pro-regenerative monocytes. To overcome the challenge of codelivering two physiochemically distinct molecules-a large hydrophilic protein and hydrophobic small molecule-we engineered a dual affinity hydrogel that exploits the growth factor affinity of a heparin derivative (Hep-N) and lipid chaperone activity of albumin. The sphingosine analog FTY720 and SDF-1α are successfully loaded and coreleased from the Hep-N-functionalized PEG-DA hydrogels while maintaining bioactivity. Placement of these hydrogels into a murine partial thickness skin wound demonstrates that corelease of FTY720 and SDF-1α yields superior recruitment of myeloid cells to the implant interface compared to either factor alone. Although in vivo delivery of FTY720 or SDF-1α individually promotes the enhanced recruitment of Ly-6Clow anti-inflammatory monocytes, codelivery enhances the early accumulation and persistence of the differentiated wound healing CD206+ macrophages in the tissue surrounding the gel. Co-delivery similarly promoted the synergistic expansion of vasculature adjacent to the implant, a key step in tissue healing. Taken together, these findings suggest that the combination of chemotactic molecules may provide additional maturation signals to the infiltrating leukocytes to facilitate macrophage transition and vascular network expansion, thus, ultimately, potentiating tissue repair. The coupling of multiple pro-regenerative biological cues provides a foundation for more fine-tuned immunoregenerative modulation to facilitate tissue repair.

Supraspinatus tendon overuse results in degenerative changes to tendon insertion region and adjacent humeral cartilage in a rat model.

The etiology of rotator cuff tendon overuse injuries is still not well understood. Furthermore, how this overuse injury impacts other components of the glenohumeral joint, including nearby articular cartilage, is also unclear. Therefore, this study sought to better understand the time course of tendon protease activity in a rat model of supraspinatus overuse, as well as determine effects of 10 weeks of overuse on humeral head articular cartilage. For these studies, multiplex gelatin zymography was used to characterize protease activity profiles in tendon and cartilage, while histological scoring/mechanical testing and micro-computed tomography (µCT) imaging were used to quantify structural damage in the supraspinatus tendon insertion and humeral articular cartilage, respectively. Histological scoring of supraspinatus tendon insertions revealed tendinopathic cellular and collagen fiber changes after 10 weeks of overuse when compared to controls, while mechanical testing revealed no significant differences between tensile moduli (overuse: 24.5 ± 11.5 MPa; control: 16.3 ± 8.7 MPa). EPIC-µCT imaging on humeral articular cartilage demonstrated significant cartilage thinning (overuse: 119.6 ± 6.34 µm; control: 195.4 ± 13.4µm), decreased proteoglycan content (overuse: 2.1 ± 0.18 cm-1 ; control: 1.65 ± 0.14 cm-1 ), and increased subchondral bone thickness (overuse: 216.2 ± 10.9 µm; control: 192 ± 17.8µm) in the overuse animals. Zymography results showed no significant upregulation of cathepsins or matrix metalloproteinases in tendon or cartilage at 2 or 10 weeks of overuse compared to controls. These results have further elucidated timing of protease activity over 10 weeks and suggest that damage occurs to other tissues in addition to the supraspinatus tendon in this overuse injury model. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1910-1918, 2017.

Exhaled volatile organic compounds in individuals with a history of high altitude pulmonary edema and varying hypoxia-induced responses.

With ascent to altitude, certain individuals are susceptible to high altitude pulmonary edema (HAPE), which in turn can cause disability and even death. The ability to identify individuals at risk of HAPE prior to ascent is poor. The present study examined the profile of volatile organic compounds (VOC) in exhaled breath condensate (EBC) and pulmonary artery systolic pressures (PASP) before and after exposure to normobaric hypoxia (12% O2) in healthy males with and without a history of HAPE (Hx HAPE, n = 5; Control, n = 11). In addition, hypoxic ventilatory response (HVR), and PASP response to normoxic exercise were also measured. Auto-regression/partial least square regression of whole gas chromatography/mass spectrometry (GC/MS) data and binary logistic regression (BLR) of individual GC peaks and physiologic parameters resulted in models that separate individual subjects into their groups with variable success. The result of BLR analysis highlights HVR, PASP response to hypoxia and the amount of benzyl alcohol and dimethylbenzaldehyde dimethyl in expired breath as markers of HAPE history. These findings indicate the utility of EBC VOC analysis to discriminate between individuals with and without a history of HAPE and identified potential novel biomarkers that correlated with physiological responses to hypoxia.

Analysis of volatile compounds in exhaled breath condensate in patients with severe pulmonary arterial hypertension.

BACKGROUND: An important challenge to pulmonary arterial hypertension (PAH) diagnosis and treatment is early detection of occult pulmonary vascular pathology. Symptoms are frequently confused with other disease entities that lead to inappropriate interventions and allow for progression to advanced states of disease. There is a significant need to develop new markers for early disease detection and management of PAH. METHODOLGY AND FINDINGS: Exhaled breath condensate (EBC) samples were compared from 30 age-matched normal healthy individuals and 27 New York Heart Association functional class III and IV idiopathic pulmonary arterial hypertenion (IPAH) patients, a subgroup of PAH. Volatile organic compounds (VOC) in EBC samples were analyzed using gas chromatography/mass spectrometry (GC/MS). Individual peaks in GC profiles were identified in both groups and correlated with pulmonary hemodynamic and clinical endpoints in the IPAH group. Additionally, GC/MS data were analyzed using autoregression followed by partial least squares regression (AR/PLSR) analysis to discriminate between the IPAH and control groups. After correcting for medicaitons, there were 62 unique compounds in the control group, 32 unique compounds in the IPAH group, and 14 in-common compounds between groups. Peak-by-peak analysis of GC profiles of IPAH group EBC samples identified 6 compounds significantly correlated with pulmonary hemodynamic variables important in IPAH diagnosis. AR/PLSR analysis of GC/MS data resulted in a distinct and identifiable metabolic signature for IPAH patients. CONCLUSIONS: These findings indicate the utility of EBC VOC analysis to discriminate between severe IPAH and a healthy population; additionally, we identified potential novel biomarkers that correlated with IPAH pulmonary hemodynamic variables that may be important in screening for less severe forms IPAH.

Biorremediación de lodos contaminados con aceites lubricantes usados / Bioremediation of sludge contaminated with used lubricants

Los lodos contaminados con residuos de aceites lubricantes usados generan gran impacto ambiental negativo al no ser manejados adecuadamente. Se propuso la biorremediación para disminuir la concentración de dichos contaminantes. Los ensayos fueron realizados en las instalaciones de la planta de tratamiento de aguas residuales (PTAR) de Río Frío (Girón, Santander, Colombia), donde se evaluaron consorcios microbianos nativos, que posteriormente se adicionaron a las biopilas conformadas por lodos deshidratados provenientes del tratamiento primario de aguas residuales domésticas (usados como fuente de materia orgánica), lodos provenientes de lavaderos de carros y lodos de alcantarillado de la zona industrial de la ciudad de Bucaramanga (Colombia). Se aislaron, identificaron y conservaron cepas microbianas con capacidad degradadora de hidrocarburos totales de petróleo (TPH) como Pseudomonas spp., Acinetobacter spp, Enterobacter cloacae, Citrobacter spp., Bacillus brevis, Micrococcus spp y Nocardia spp. Se hizo una serie de pruebas piloto donde se inoculó cada montaje con un consorcio bacteriano a una concentración de 3x108 UFC/ml de bacterias y microorganismos fúngicos como Aspergillus spp., Fusarium spp., Trichoderma spp., a una concentración de 1x106 esporas/ml; se monitorearon parámetros de temperatura, pH, humedad y oxigenación. Se realizaron dos ensayos para verificar el comportamiento de dichos tratamientos; se analizó la variable continua TPH en ppm mediante el método de modelos mixtos lineares en bloques aleatorios completos, que revelaron diferencias significativas entre la biopila control y las biopilas bajo prueba; se obtuvieron porcentajes de remoción hasta de 94% de TPH en 120 días y 84% en 40 días, lo que reflejó un efecto positivo en la utilización de los consorcios de microorganismos bajo prueba en la descontaminación de lodos de alcantarillado industrial y lodos de lavaderos de carros.

The sludge contaminated with residues of used lubricating oils produce large negative environmental impact by not being handled properly. We proposed Biorremediation to decreasethe concentration of these polltants. The trials were conducted on the waste water treatment plant (WWTP) Río Frío (Girón, Santander, Colombia) ,we evaluate native microbial associations, and subsequently they were added to biopiles, made up of dried sludge the waste water treatment (source of organic mater) sludge from washing cars and sewage sludge from the industrial area of the city Bucaramanga (Colombia). Several pilot test were completed and we isolated, identified and retained microbial atrains with ability to degrading total petroleum hydrocarbons (TPH) such as Pseudomonas spp., Escherichia coli, Citrobacter spp., Bacillus brevis, Micrococcus spp., among others. We inoculated each pilot assembly with a bacterial concentration of 3x108 UFC/ml and fungal microorganisms like Aspergillus spp., Fusarium spp., Trichoderma spp. in a concentration of 1x106 Spores/ml. Parameters such as temperature, pH, humidity, oxygenation were monitoring frequently. Two trials were completed to verify the behabior and results of treatment, we analized continuously the concentration of TPH using linear mixed models approach in a randomized complete blocks, which revealed significant differences between control biopile (without microorganism consortia) and biopiles under test, obtaining removal percentages to 94% of TPH in 120 days, and 84% in 40 days, reflecting a positive effect on the use of consortia of microorganisms under test in the decontamination of domestic sewage sludge and industrial sludge and sludge the car wash.