Key points
Mitochondria are frequently implicated in the ageing of skeletal muscle, although the role of denervation in modulating mitochondrial function in ageing muscle is unknown.
We show that ...increased sensitivity to apoptosis initiation occurs prior to evidence of persistent denervation and is thus a primary mitochondrial defect in ageing muscle worthy of therapeutic targeting.
However, at more advanced age, mitochondrial function changes are markedly impacted by persistent sporadic myofibre denervation, suggesting the mitochondrion may be a less viable therapeutic target.
Experimental denervation modulates mitochondrial function, where changes in both reactive oxygen species (ROS) and sensitivity to permeability transition are implicated in the resultant muscle atrophy. Notably, although denervation occurs sporadically in ageing muscle, its impact on ageing muscle mitochondria is unknown. Because this information has important therapeutic implications concerning targeting the mitochondrion in ageing muscle, we examined mitochondrial function in skeletal muscle from four groups of humans, comprising two active (mean ± SD age: 23.7 ± 2.7 years and 71.2 ± 4.9 years) and two inactive groups (64.8 ± 3.1 years and 82.5 ± 4.8 years), and compared this with a murine model of sporadic denervation. We tested the hypothesis that, although some alterations of mitochondrial function in aged muscle are attributable to a primary organelle defect, mitochondrial dysfunction would be impacted by persistent denervation in advanced age. Both ageing in humans and sporadic denervation in mice increased mitochondrial sensitivity to permeability transition (humans, P = 0.004; mice, P = 0.01). To determine the contribution of sporadic denervation to mitochondrial function, we pharmacologically inhibited the denervation‐induced ROS response. This reduced ROS emission by 60% (P = 0.02) in sporadically denervated mouse muscle, which is similar to that seen in humans older than 75 years (–66%, P = 0.02) but not those younger than 75 years. We conclude that an increased sensitivity to permeability transition is a primary mitochondrial defect in ageing muscle. However, at more advanced age, when muscle atrophy becomes more clinically severe, mitochondrial function changes are markedly impacted by persistent sporadic denervation, making the mitochondrion a less viable therapeutic target.
Key points
Mitochondria are frequently implicated in the ageing of skeletal muscle, although the role of denervation in modulating mitochondrial function in ageing muscle is unknown.
We show that increased sensitivity to apoptosis initiation occurs prior to evidence of persistent denervation and is thus a primary mitochondrial defect in ageing muscle worthy of therapeutic targeting.
However, at more advanced age, mitochondrial function changes are markedly impacted by persistent sporadic myofibre denervation, suggesting the mitochondrion may be a less viable therapeutic target.
Health facility stock-outs of life saving malaria medicines are common across Africa. Innovative ways of addressing this problem are urgently required. We evaluated whether SMS based reporting of ...stocks of artemether-lumefantrine (AL) and rapid diagnostic tests (RDT) can result in reduction of stock-outs at peripheral facilities in Kenya.
All 87 public health facilities in five Kenyan districts were included in a 26 week project. Weekly facility stock counts of four AL packs and RDTs were sent via structured incentivized SMS communication process from health workers' personal mobile phones to a web-based system accessed by district managers. The mean health facility response rate was 97% with a mean formatting error rate of 3%. Accuracy of stock count reports was 79% while accuracy of stock-out reports was 93%. District managers accessed the system 1,037 times at an average of eight times per week. The system was accessed in 82% of the study weeks. Comparing weeks 1 and 26, stock-out of one or more AL packs declined by 38 percentage-points. Total AL stock-out declined by 5 percentage-points and was eliminated by the end of the project. Stock-out declines of individual AL packs ranged from 14 to 32 percentage-points while decline in RDT stock-outs was 24 percentage-points. District managers responded to 44% of AL and 73% of RDT stock-out signals by redistributing commodities between facilities. In comparison with national trends, stock-out declines in study areas were greater, sharper and more sustained.
Use of simple SMS technology ensured high reporting rates of reasonably accurate, real-time facility stock data that were used by district managers to undertake corrective actions to reduce stock-outs. Future work on stock monitoring via SMS should focus on assessing response rates without use of incentives and demonstrating effectiveness of such interventions on a larger scale.
Abstract
Muscle atrophy arises because of many chronic illnesses, as well as from prolonged glucocorticoid treatment and nutrient deprivation. We previously demonstrated that the USP19 ...deubiquitinating enzyme plays an important role in chronic glucocorticoid- and denervation-induced muscle wasting. However, the mechanisms by which USP19 exerts its effects remain unknown. To explore this further, we fasted mice for 48 hours to try to identify early differences in the response of wild-type and USP19 knockout (KO) mice that could yield insights into the mechanisms of USP19 action. USP19 KO mice manifested less myofiber atrophy in response to fasting due to increased rates of protein synthesis. Insulin signaling was enhanced in the KO mice, as revealed by lower circulating insulin levels, increased insulin-stimulated glucose disposal and phosphorylation of Akt and S6K in muscle, and improved overall glucose tolerance. Glucocorticoid signaling, which is essential in many conditions of atrophy, was decreased in KO muscle, as revealed by decreased expression of glucocorticoid receptor (GR) target genes upon both fasting and glucocorticoid treatment. This decreased GR signaling was associated with lower GR protein levels in the USP19 KO muscle. Restoring the GR levels in USP19-deficient muscle was sufficient to abolish the protection from myofiber atrophy. Expression of GR target genes also correlated with that of USP19 in human muscle samples. Thus, USP19 modulates GR levels and in so doing may modulate both insulin and glucocorticoid signaling, two critical pathways that control protein turnover in muscle and overall glucose homeostasis.
USP19 deubiquitinating enzyme KO mice have enhanced insulin signaling and decreased glucocorticoid signaling that can explain the protection from muscle wasting seen in these mice.
Increasing numbers of cancer patients are using Chinese herbs (CHs). However, differences among prior studies make it difficult to draw firm conclusions about the clinical usefulness of any specific ...CH formula. The primary objective of this study was to establish the acceptability of taking a standardized CH formula for patients with advanced lung cancer. The secondary objective was to identify any toxicities attributable to this CH formula and to measure changes in quality of life.
A single-arm, prospective study of a 6-week intervention with a selected CH formula in 15 patients with stage 4 nonsmall-cell lung cancer (NSCLC, Seventh American Joint Committee on Cancer TNM staging system).
Patients with advanced lung cancer were interested in using the CH formula. Completion (93%) and adherence (98%) levels were very high and most patients perceived the CH treatment as easy to take and were willing to take the CHs used in the study again if it was available. About half of the patients reported adverse events, all of which were mild (Grade 1 or 2) and only a small minority (8%) were potentially related to CHs. No biochemical or hematological evidence of toxicity was observed. Overall, there were improvement in quality of life, and reduced feelings of tiredness and sleepiness.
This study provides preliminary evidence that short-term use of a carefully selected and prepared CH formula in patients with stage 4 NSCLC is acceptable and safe.
The explosion of the Chernobyl Nuclear Power Plant resulted in some of the most radioactively contaminated habitats on earth. Despite evacuation of all human inhabitants from the most contaminated ...areas, animals and plants continue to thrive in these areas. This study examines the levels of contamination and genetic damage associated with radiocesium in catfish (Ictalurus punctatus) from the cooling pond and a control site. In general, catfish from the cooling pond exhibit greater genetic damage, and the amount of damage is related to the concentration of radiocesium in individual fish. Genetic damage is primarily in the form of DNA strand breaks, with few micronuclei being observed in contaminated fish. The possible roles that acclimation and adaption play in the response to high levels of radiation exposure are discussed.
Patients infrequently present with advanced-stage cervical malignancy in the United States, where access to care and aggressive screening, detection, and treatment regimens are the standard. ...Neglected cancer is more likely in countries with underdeveloped healthcare delivery systems; yet in this new millennium, we foresee not only an aging population with modern medicine able to prolong life expectancy, but also attentive screening regimens even amid the older old. Taking into account common comorbid illness from which patients used to die, informed consent in making a treatment in the robust and frail elderly becomes a new challenge. Recognizing an ever-growing population in today's culture of patient-directed care, clinicians may find patients choosing alternative modalities or simply declining conventional therapies. The difficult dilemma then arises about how to inform a patient most accurately of her prognosis in an untreated condition. In the past, virtually all patients in the United States traditionally received some treatment for cervical cancer on diagnosis; thus, review was made of archival published literature to document survival of patients with untreated cervical cancer.
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