Task-shifting in asthma and chronic obstructive pulmonary disease management: A review of the obstructive lung disease program.

Objective: Task shifting, an approach to address physician shortage through redistribution of clinical tasks, may help address the high burden of chronic respiratory diseases like asthma and COPD. We aimed to measure its utility and impact in the Obstructive Lung Disease program (OLD). Methods: A retrospective, cross-sectional study was conducted at five integrated outpatient departments of Primary Care Program within Indus Hospital & Health Network, Pakistan, from January 2018 to March 2023. After a formative evaluation, registered nurses were trained as Lung Health Nurses (LHNs) to perform spirometry, collect Patient Reported Outcome Measures (PROMs) including Asthma Control Test (ACT), modified Medical Research Council (mMRC) dyspnea score and COPD Assessment Test (CAT), counsel on inhaler use and tobacco cessation, and refer to pulmonary rehabilitation (PR). Data was collected online contemporaneously on REDCap and later analyzed using Excel and STATA 14. Results: Pre-implementation, a monthly average of 126 asthmatics and 33 COPD patients visited primary care centers. Medical records of 147 OLD patients showed 8% received inhaler education, 3% completed ACT and 2% had mMRC documented. Implementation included capacity building of nine LHNs. Of 7427 referrals to the program, 86% underwent nurse-led assessments. LHNs performed spirometry (92%), PROMs assessments [ACT (89%), CAT (91%), mMRC (85%)], inhaler education (97%), tobacco cessation advice (85%) and made PR referrals (94%). Conclusion: Trained nurses can play a role in providing holistic and timely care for patients with CRDs and strengthen existing healthcare systems. Future directions may include expanding nurse clinical counselling roles through telehealth monitoring and home management.

Perceptions of students regarding innovative approaches introduced in nutrition and metabolism module at Shifa college of medicine.

Objective: To assess the perceptions of 2nd year medical students regarding certain approaches introduced in the course of Nutrition and Metabolism module. METHODS: The descriptive study was conducted at the Shifa College of Medicine, Islamabad, Pakistan, in December 2020, and comprised all 2nd year medical students who completed the Nutrition and Metabolism module in which new components had been added, including introduction to community nutrition, school visits, Islamic perspective of nutrition, journal club and e-posters. Data was collected using a questionnaire based on the modified Dundee Ready Education Environment Measure, and had 5 categories with a total of 25 questions that were scored on a 5-point Likert scale. Data was analysed using SPSS 22. RESULTS: Of the 100 students, 65(65%) were females and 35(35%) were males. The overall mean age was 20.5 ± 0.5 years. The total mean score was 74.68±2.53. Mean score for student's perception of learning was 38.17±0.17, student's perception of teachers 9.27±0.18, student's academic self-perceptions 12.1±0.11, student's perceptions of atmosphere 9.03±0.03 and student's social self-perceptions 6.11± 0.01. Conclusion: The perceptions medical students about innovations were positive, showing an encouraging attitude in terms of learning approach and outcome.

The Obstructive Lung Diseases Program: Integrated obstructive lung disease services within primary care in Pakistan.

Objective: To assess the learning impact of e-curriculums on healthcare professionals (HCPs). The second objective was to report the screening, detection and clinical features of patients with obstructive lung diseases (OLD) through an integrated care program at The Indus Hospital & Health Network (IHHN), Karachi, Pakistan. Methods: A retrospective, observational study was conducted in the Family Medicine outpatient department from January 2019 till July 2021. HCPs were trained on the diagnosis and management of OLD through e-learning. Patients were screened clinically for OLD and had spirometry performed if suspect. Baseline characteristics, patient-reported outcome measures (PROMs), spirometry and treatment modalities were collected. Univariate analysis was done on Excel and paired t-testing was performed on Stata 16. Results: Online training on clinical aspects of OLD was completed by 33 HCPs, amongst whom 77.9% demonstrated improved post-test evaluations of 26.8% (p=0.000). Of 1896 patients screened, 60.8% were diagnosed as OLD. Asthmatics accounted for 66.5% (60.9% females, median age 39 years). In 84.5% of patients who completed PROMs, poor control of symptoms was reported. Inhaler technique was taught in 66.5%. Breathless patients, with a high modified Medical Research Council score (mMRC ≥ 2, n=234), were referred for pulmonary rehabilitation in 92% of cases. Tobacco cessation advice was delivered to 61.1% of all current users (n=229). Conclusion: The OLD program uses capacity building, gold standard diagnostics and updated management strategies in primary care, allowing earlier diagnosis of suspected patients and implementation of evidence-based interventions, aiming to improve their morbidity and mortality.

Metabolic phenotype of skeletal muscle in early critical illness.

OBJECTIVES: To characterise the sketetal muscle metabolic phenotype during early critical illness. METHODS: Vastus lateralis muscle biopsies and serum samples (days 1 and 7) were obtained from 63 intensive care patients (59% male, 54.7±18.0 years, Acute Physiology and Chronic Health Evaluation II score 23.5±6.5). MEASUREMENTS AND MAIN RESULTS: From day 1 to 7, there was a reduction in mitochondrial beta-oxidation enzyme concentrations, mitochondrial biogenesis markers (PGC1α messenger mRNA expression (-27.4CN (95% CI -123.9 to 14.3); n=23; p=0.025) and mitochondrial DNA copy number (-1859CN (IQR -5557-1325); n=35; p=0.032). Intramuscular ATP content was reduced compared tocompared with controls on day 1 (17.7mmol/kg /dry weight (dw) (95% CI 15.3 to 20.0) vs. 21.7 mmol/kg /dw (95% CI 20.4 to 22.9); p<0.001) and decreased over 7 days (-4.8 mmol/kg dw (IQR -8.0-1.2); n=33; p=0.001). In addition, the ratio of phosphorylated:total AMP-K (the bioenergetic sensor) increased (0.52 (IQR -0.09-2.6); n=31; p<0.001). There was an increase in intramuscular phosphocholine (847.2AU (IQR 232.5-1672); n=15; p=0.022), intramuscular tumour necrosis factor receptor 1 (0.66 µg (IQR -0.44-3.33); n=29; p=0.041) and IL-10 (13.6 ng (IQR 3.4-39.0); n=29; p=0.004). Serum adiponectin (10.3 µg (95% CI 6.8 to 13.7); p<0.001) and ghrelin (16.0 ng/mL (IQR -7-100); p=0.028) increased. Network analysis revealed a close and direct relationship between bioenergetic impairment and reduction in muscle mass and between intramuscular inflammation and impaired anabolic signaling. ATP content and muscle mass were unrelated to lipids delivered. CONCLUSIONS: Decreased mitochondrial biogenesis and dysregulated lipid oxidation contribute to compromised skeletal muscle bioenergetic status. In addition, intramuscular inflammation was associated with impaired anabolic recovery with lipid delivery observed as bioenergetically inert. Future clinical work will focus on these key areas to ameliorate acute skeletal muscle wasting. TRIAL REGISTRATION NUMBER: NCT01106300.

Serum levels of leptin, zinc and tryptophan in obese subjects with sleep deficits.

Obesity is an important risk factor for sleep disorders. This study aimed to evaluate the association of leptin, zinc and tryptophan (TRP) in obese subjects with sleep deficits [sleep apnea (SA), insomnia (IN)]. In this cross sectional case control, with the verbal and written consent 206, obese with sleep deficits and 30, non-obese/normal identified from various areas of Karachi, Pakistan. The socio-demographic data including; age, body mass index (BMI), education and residence, of participants was collected. After providing informed consent, fasting blood samples were taken and serum was collected. The serum concentration of leptin, zinc and TRP were analyzed by ELISA (Enzyme-linked immunosorbent assay), FAAS (Flame atomic absorption spectrophotometer) and HPLC (High performance liquid chromatography) respectively. A significant correlation was found between BMI (body mass index) and leptin, BMI and zinc, BMI and TRP. The correlation between leptin consecutively was significantly associated with zinc and TRP in obese patients. Sleep deficits elevated circulatory levels of leptin while lower zinc and TRP levels compared to levels seen in non-obese (Normal) subjects with no sleep deficits. Obese subjects exhibited significantly higher levels of leptin with sleep deficits compared with non-obese subjects with normal sleep pattern, while obese subjects with SA had significantly high levels of leptin than obese subjects with IN and IN+SA. Patients with sleep deficits had significantly lower levels of serum TRP and zinc than non-obese subjects with normal sleep pattern. Obese subjects with SA had significantly lower levels of zinc and elevated levels of TRP than obese subjects with IN. Obese patients with IN+SA had significantly lower levels of leptin and zinc than IN and SA , while TRP levels were significantly lower in subjects with IN than obese subjects with IN+SA and IN. These results suggest that elevated levels of leptin which are possibly by adiposity and lessened levels of zinc and TRP have a great impact on progression of obesity and their association can contribute to tempt sleep disorders.

Detailed characterization of a long-term rodent model of critical illness and recovery.

OBJECTIVE: To characterize a long-term model of recovery from critical illness, with particular emphasis on cardiorespiratory, metabolic, and muscle function. DESIGN: Randomized controlled animal study. SETTING: University research laboratory. SUBJECTS: Male Wistar rats. INTERVENTIONS: Intraperitoneal injection of the fungal cell wall constituent, zymosan or n-saline. MEASUREMENTS AND MAIN RESULTS: Following intervention, rats were followed for up to 2 weeks. Animals with zymosan peritonitis reached a clinical and biochemical nadir on day 2. Initial reductions were seen in body weight, total body protein and fat, and muscle mass. Leg muscle fiber diameter remained subnormal at 14 days with evidence of persisting myonecrosis, even though gene expression of regulators of muscle mass (e.g., MAFbx, MURF1, and myostatin) had peaked on days 2-4 but normalized by day 7. Treadmill exercise capacity, forelimb grip strength, and in vivo maximum tetanic force were also reduced. Food intake was minimal until day 4 but increased thereafter. This did not relate to appetite hormone levels with early (6 hr) rises in plasma insulin and leptin followed by persisting subnormal levels; ghrelin levels did not change. Serum interleukin-6 level peaked at 6 hours but had normalized by day 2, whereas interleukin-10 remained persistently elevated and high-density lipoprotein cholesterol persistently depressed. There was an early myocardial depression and rise in core temperature, yet reduced oxygen consumption and respiratory exchange ratio with a loss of diurnal rhythmicity that showed a gradual but incomplete recovery by day 7. CONCLUSIONS: This detailed physiological, metabolic, hormonal, functional, and histological muscle characterization of a model of critical illness and recovery reproduces many of the findings reported in human critical illness. It can be used to assess putative therapies that may attenuate loss, or enhance recovery, of muscle mass and function.

The FRESHAIR4Life study: Global implementation research on non-communicable disease prevention targeting adolescents' exposure to tobacco and air pollution in disadvantaged populations.

The FRESHAIR4Life study aims to reduce the non-communicable disease (NCD) burden by implementing preventive interventions targeting adolescents' exposure to tobacco use and air pollution (AP) worldwide. This paper presents the FRESHAIR4Life methodology and initial rapid review results. The rapid review, using various databases and PubMed, aimed to guide decision-making on risk factor focus, target areas, and populations. It showed variable NCD mortality rates related to tobacco use and AP across the participating countries, with tobacco as the main risk factor in the Kyrgyz Republic, Greece, and Romania, and AP prevailing in Pakistan and Uganda. Adolescent exposure levels, sources, and correlates varied. The study will continue with an in-depth situational analysis to guide the selection, adaptation, and integration of evidence-based interventions into the FRESHAIR4Life prevention package. This package will be implemented, evaluated, assessed for cost-effectiveness, and iteratively refined. The research places a strong emphasis on co-creation, capacity building, and comprehensive communication and dissemination.

Artificial intelligence-reported chest X-ray findings of culture-confirmed pulmonary tuberculosis in people with and without diabetes.

Objectives: We applied computer-aided detection (CAD) software for chest X-ray (CXR) analysis to determine if diabetes affects the radiographic presentation of tuberculosis. Methods: From March 2017-July 2018, we consecutively enrolled adults being evaluated for pulmonary tuberculosis in Karachi, Pakistan. Participants had same-day CXR, two sputum mycobacterial cultures, and random blood glucose measurement. We identified diabetes through self-report or glucose >11.1mMol/L. We included participants with culture-confirmed tuberculosis for this analysis. We used linear regression to estimate associations between CAD-reported tuberculosis abnormality score (range 0.00 to 1.00) and diabetes, adjusting for age, body mass index, sputum smear-status, and prior tuberculosis. We also compared radiographic abnormalities between participants with and without diabetes. Results: 63/272 (23%) of included participants had diabetes. After adjustment, diabetes was associated with higher CAD tuberculosis abnormality scores (p < 0.001). Diabetes was not associated with frequency of CAD-reported radiographic abnormalities apart from cavitary disease; participants with diabetes were more likely to have cavitary disease (74.6% vs 61.2% p = 0.07), particularly non-upper zone cavitary disease (17% vs 7.8%, p = 0.09). Conclusions: CAD analysis of CXR suggests diabetes is associated with more extensive radiographic abnormalities and with greater likelihood of cavities outside upper lung zones.

Does the Implementation of Flipped Classroom Model Improve the Learning Outcomes of Medical College Students? A Single Centre Analysis.

OBJECTIVE: To assess the perspectives of the first year and second year MBBS students of College, regarding the effectiveness of flipped classroom learning as compared to the traditional mode of teaching. STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: Shifa College of Medicine, Islamabad, Pakistan, from August to September 2021. METHODOLOGY: This descriptive study was conducted on all first and second year MBBS students in College after informed consent. A self-developed questionnaire formulated after a thorough literature search, with 16 questions was given. Quantitative data was collected after ethical approval and was analysed using SPSS version 22. Percentages and mean were calculated for descriptive analysis whereas qualitative data was analysed through thematic analysis Results: Out of the 156 responders, 61% students believed that flipped classroom buttressed a better understanding of study objectives, 24% stated that it didn't make much of a difference whereas 15% had a negative response in this respect. The majority (90%) reckoned that learning beforehand fostered better discussions and made the whole learning process much easier. Seventy-five percent believed that it has improved their grades. Although, some students did point out that sometimes meandering through various study sources consumed a lot of their time but overall they held a satisfactory opinion of flipped pedagogy (85%). CONCLUSION: The students enrolled in the study asserted the usage of flipped classrooms as a likeable and preferable teaching method in medical institutions. Not only it engaged students in active learning and helped them improve their grades but also enabled them to sharpen cognitive and presentation skills, which are the prime objects of undergraduate pedagogy. KEY WORDS: Flipped classroom, Medical education, Medical students, e-learning.

Diagnostic accuracy of a commercially available, deep learning-based chest X-ray interpretation software for detecting culture-confirmed pulmonary tuberculosis.

BACKGROUND: Few evaluations of computer-aided detection (CAD) software for analyzing chest radiographs for tuberculosis have used mycobacterial culture as the reference standard. METHODS: Using data from a prospective study of symptomatic adults and household contacts of persons with tuberculosis who were seeking care in Karachi, we evaluated the accuracy of LUNIT INSIGHT version 3.1.0.0 (LUNIT, South Korea) for detecting pulmonary tuberculosis in the triage use case. The reference standard was liquid culture. We estimated the diagnostic accuracy using three developer-recommended threshold scores for tuberculosis: 15, 30, and 45. RESULTS: A total 269 of 2190 (12%) participants had culture-confirmed pulmonary tuberculosis. LUNIT-reported abnormalities of nodule, consolidation, fibrosis, and pleural effusion were more common with culture-confirmed tuberculosis. At the tuberculosis threshold score of 30, sensitivity and specificity were, respectively, 87.7% [95% CI: 83.2-91.4%] and 64.3% [62.1-66.4%]. Sensitivity was similar at scores of 15, 88.1% [95% CI: 83.6-91.7%] and 45, 86.6% [82.0 - 90.5%]; and specificity was 57.9% [55.7-60.2%] and 69.9% [67.8-71.9%], respectively. Sensitivity was lower for smear-negative disease, and specificity was lower with increasing age, previous tuberculosis, and decreasing body mass index. Diabetes and tobacco smoking did not modify accuracy. CONCLUSION: In a population where most tuberculosis was smear-positive, LUNIT-reported radiographic abnormalities were associated with culture-confirmed disease. Manufacturer-recommended threshold scores had limited sensitivity.

Neutralizing Antibody Response to BBIBP-CorV in Comparison with COVID-19 Recovered, Unvaccinated Individuals in a Sample of the Pakistani Population.

Fifty five percent of the Pakistani population is still unvaccinated with the two-dose protocol of COVID-19 vaccines. This study was undertaken to determine the seroconversion rate and antibody titers following the two-dose BBIBP-CorV protocol, and to compare these variables in unvaccinated, COVID-19 recovered individuals (total n = 180) at Indus Hospital and Health Network, Karachi. Pseudotyped lentivirus antibody neutralization assays and SARS-CoV-2 IgG Quant II (Abbott) immunoassays were performed 4-8 weeks following the second dose of the BBIBP-CorV or PCR positivity/onset of symptoms of COVID-19. Seroconversion rate, using neutralization assays, in vaccinated individuals was lower (78%) than that in unvaccinated, COVID-19-recovered individuals with moderate to severe infection (97%). Prior PCR positivity increased serocoversion rate to 98% in vaccinated individuals. Immunoassays did not, however, reveal significant inter-group differences in seroconversion rates (≥95% in all groups). Log10 mean antibody neutralizing titers following the two-dose BBIBP-CorV protocol (IC50 = 2.21) were found to be significantly less than those succeeding moderate to severe COVID-19 (IC50 = 2.94). Prior SARS-CoV-2 positivity significantly increased post-vaccination antibody titers (IC50 = 2.82). Similar inter-group titer differences were obtained using the immunoassay. BBIBP-CorV post-vaccination titers may, thus, be lower than those following natural, moderate to severe infection, while prior SARS-CoV-2 exposure increases these titers to more closely approximate the latter.

Measuring fidelity to delivery of a new smoking cessation intervention integrated into routine tuberculosis care in Pakistan and Bangladesh: Contextual differences and opportunities.

INTRODUCTION: Tobacco smoking among tuberculosis (TB) patients leads to poorer treatment outcomes. Smoking cessation support should be integrated into routine TB care. We measured healthcare providers' fidelity to a smoking cessation intervention integrated into routine TB care, in Bangladesh and Pakistan. We aimed to understand the role of providers and settings in the implementation of behavior support (BS) messages for TB and smoking cessation. METHODS: The integrated BS intervention was implemented in TB clinics (24 public and 1 private). Cross-sectional data were collected on the fidelity of delivery of the BS intervention using a predefined fidelity index based on an existing validated method of measuring intervention fidelity. Audio-recordings of patient-provider BS sessions were coded using the fidelity index. Intervention fidelity was presented as the proportion of sessions that implemented BS messages. RESULTS: A total of 96 sessions were conducted, 37 in Bangladesh and 59 in Pakistan. In public settings, TB medication advice was offered in 91.9% (95% CI: 78.7- 97.2) of sessions in Bangladesh, and in 75.5% (95% CI: 62.4-85.1) of sessions in Pakistan; whilst it was offered in 83.3% (95% CI: 43.7-97.0) of sessions in the private setting in Pakistan. Patients' smoking status was assessed in 70.3% (95% CI: 54.2-82.5) of sessions in Bangladesh, and in 34.0% (95% CI: 22.7-47.4) of sessions in the public setting and in 66.7% (95% CI: 30.0-90.3) of sessions in the private setting in Pakistan. A quit date was set in 32.4% (95% CI: 19.6-48.5) of all sessions in Bangladesh, and in 33.3% (95% CI: 9.6-70.0) of all sessions in the public setting in Pakistan. CONCLUSIONS: Fidelity to the intended delivery of the intervention was found to be high for TB-related messages but not for smoking cessation messages. Clinic contexts may play a mediating role in health workers' opportunities to deliver the intervention as planned. TRIAL REGISTRATION: International Standard Randomized Clinical Trial Number (ISRCTN43811467). Registered 23 March 2016, https://doi.org/10.1186/ISRCTN43811467.

Effect of Drought Stress on Capsaicin and Antioxidant Contents in Pepper Genotypes at Reproductive Stage.

Pepper is one of the most important vegetables and spices in the world. Principal pungency is contributed by secondary metabolites called capsaicinoids, mainly synthesized in the placenta of pepper fruit. Various factors, including drought, limit pepper production. Flowering is one of the most sensitive stages affected by drought stress. The current study was conducted to determine the effect of drought on different pepper genotypes at the flowering and pod formation stages. Hot pepper (Pusajuala and Ghotki) and Bell pepper (Green Wonder and PPE-311) genotypes were subjected to drought (35% field capacity) at two different stages (flowering (DF) and pod formation (DP) stage). In comparison, control plants were maintained at 65% field capacity. The data regarding flowering survival rates, antioxidant protein activity, and proline content, were collected. Results indicated that parameters like flower survival percentage, number of fruits per plant, and fruit weight had significant differences among the genotypes in both treatments. A high proline level was observed in Green Wonder at the pod formation stage compared to other genotypes. Capsaicin contents of hot pepper genotypes were affected at the pod formation stage. Antioxidants like GPX were highly active (190 units) in Ghotki at pod formation. Bell pepper genotypes had a high APX activity, highly observed (100 units) in PPE-311 at pod formation, and significantly differ from hot pepper genotypes. In the catalase case, all the genotypes had the highest values in DP compared to control and DF, but Pusajuala (91 units) and Green Wonder (83 units) performed best compared to other genotypes. Overall, the results indicate that drought stress decreased reproductive growth parameters and pungency of pepper fruit as most of the plant energy was consumed in defense molecules (antioxidants). Therefore, water availability at the flowering and pod formation stage is critical to ensure good yield and pepper quality.

Chest x-ray analysis with deep learning-based software as a triage test for pulmonary tuberculosis: a prospective study of diagnostic accuracy for culture-confirmed disease.

BACKGROUND: Deep learning-based radiological image analysis could facilitate use of chest x-rays as triage tests for pulmonary tuberculosis in resource-limited settings. We sought to determine whether commercially available chest x-ray analysis software meet WHO recommendations for minimal sensitivity and specificity as pulmonary tuberculosis triage tests. METHODS: We recruited symptomatic adults at the Indus Hospital, Karachi, Pakistan. We compared two software, qXR version 2.0 (qXRv2) and CAD4TB version 6.0 (CAD4TBv6), with a reference of mycobacterial culture of two sputa. We assessed qXRv2 using its manufacturer prespecified threshold score for chest x-ray classification as tuberculosis present versus not present. For CAD4TBv6, we used a data-derived threshold, because it does not have a prespecified one. We tested for non-inferiority to preset WHO recommendations (0·90 for sensitivity, 0·70 for specificity) using a non-inferiority limit of 0·05. We identified factors associated with accuracy by stratification and logistic regression. FINDINGS: We included 2198 (92·7%) of 2370 enrolled participants. 2187 (99·5%) of 2198 were HIV-negative, and 272 (12·4%) had culture-confirmed pulmonary tuberculosis. For both software, accuracy was non-inferior to WHO-recommended minimum values (qXRv2 sensitivity 0·93 [95% CI 0·89-0·95], non-inferiority p=0·0002; CAD4TBv6 sensitivity 0·93 [0·90-0·96], p<0·0001; qXRv2 specificity 0·75 [0·73-0·77], p<0·0001; CAD4TBv6 specificity 0·69 [0·67-0·71], p=0·0003). Sensitivity was lower in smear-negative pulmonary tuberculosis for both software, and in women for CAD4TBv6. Specificity was lower in men and in those with previous tuberculosis, and reduced with increasing age and decreasing body mass index. Smoking and diabetes did not affect accuracy. INTERPRETATION: In an HIV-negative population, these software met WHO-recommended minimal accuracy for pulmonary tuberculosis triage tests. Sensitivity will be lower when smear-negative pulmonary tuberculosis is more prevalent. FUNDING: Canadian Institutes of Health Research.

Impact of ghrelin on body composition and muscle function in a long-term rodent model of critical illness.

BACKGROUND: Patients with multiple injuries or sepsis requiring intensive care treatment invariably develop a catabolic state with resultant loss of lean body mass, for which there are currently no effective treatments. Recovery can take months and mortality is high. We hypothesise that treatment with the orexigenic and anti-inflammatory gastric hormone, ghrelin may attenuate the loss of body mass following critical illness and improve recovery. METHODS: Male Wistar rats received an intraperitoneal injection of the fungal cell wall derivative zymosan to induce a prolonged peritonitis and consequent critical illness. Commencing at 48h after zymosan, animals were randomised to receive a continuous infusion of ghrelin or vehicle control using a pre-implanted subcutaneous osmotic mini-pump, and continued for 10 days. RESULTS: Zymosan peritonitis induced significant weight loss and reduced food intake with a nadir at Day 2 and gradual recovery thereafter. Supra-physiologic plasma ghrelin levels were achieved in the treated animals. Ghrelin-treated rats ate more food and gained more body mass than controls. Ghrelin increased adiposity and promoted carbohydrate over fat metabolism, but did not alter total body protein, muscle strength nor muscle morphology. Muscle mass and strength remained significantly reduced in all zymosan-treated animals, even at ten days post-insult. CONCLUSIONS: Continuous infusion of ghrelin increased body mass and food intake, but did not increase muscle mass nor improve muscle function, in a long-term critical illness recovery model. Further studies with pulsatile ghrelin delivery or additional anabolic stimuli may further clarify the utility of ghrelin in survivors of critical illness.

Measurement of H2O2 within living Drosophila during aging using a ratiometric mass spectrometry probe targeted to the mitochondrial matrix.

Hydrogen peroxide (H(2)O(2)) is central to mitochondrial oxidative damage and redox signaling, but its roles are poorly understood due to the difficulty of measuring mitochondrial H(2)O(2) in vivo. Here we report a ratiometric mass spectrometry probe approach to assess mitochondrial matrix H(2)O(2) levels in vivo. The probe, MitoB, comprises a triphenylphosphonium (TPP) cation driving its accumulation within mitochondria, conjugated to an arylboronic acid that reacts with H(2)O(2) to form a phenol, MitoP. Quantifying the MitoP/MitoB ratio by liquid chromatography-tandem mass spectrometry enabled measurement of a weighted average of mitochondrial H(2)O(2) that predominantly reports on thoracic muscle mitochondria within living flies. There was an increase in mitochondrial H(2)O(2) with age in flies, which was not coordinately altered by interventions that modulated life span. Our findings provide approaches to investigate mitochondrial ROS in vivo and suggest that while an increase in overall mitochondrial H(2)O(2) correlates with aging, it may not be causative.