The effect of protein or amino acid provision on immobilization-induced muscle atrophy in healthy adults: A systematic review and meta-analysis.

Bed rest and limb immobilization are models of muscle disuse associated with skeletal muscle atrophy and reduced strength. The purpose of this systematic review was to examine the impact of protein or amino acid provision before and/or during a period of muscle disuse on muscle atrophy (primary outcome), strength and muscle protein synthesis (secondary outcomes) following a disuse period. We performed a systematic review of Embase, MEDLINE, Web of Science, PubMed and Clinical Trials in December 2022. Eligible studies were randomized controlled trials that combined a dietary protein or amino acid intervention versus control during an experimental model of disuse (bed rest or unilateral limb immobilization) in healthy individuals aged ≥18 years. Nine articles from eight independent trials were identified and rated for risk of bias by two authors. A meta-analysis of muscle mass data revealed no effect (standardized mean difference: 0.2; 95% confidence interval: -0.18 to 0.57, P = 0.31) of protein/amino acid intervention in preventing disuse-induced muscle atrophy. Although the meta-analysis was not conducted on strength or muscle protein synthesis data, there was insufficient evidence in the reviewed articles to support the use of protein/amino acid provision in mitigating the disuse-induced decline in either outcome measurement. Additional high-quality studies, including the reporting of randomization procedures and blinding procedures and the provision of statistical analysis plans, might be required to determine whether protein or amino acid provision serves as an effective strategy to attenuate muscle atrophy during periods of disuse.

Valproic acid disables the Nrf2 anti-oxidant response in acute myeloid leukaemia cells enhancing reactive oxygen species-mediated killing.

BACKGROUND: We previously demonstrated the in vitro killing of AML cells by the combination of the lipid-lowering agent bezafibrate (BEZ) and the contraceptive hormone medroxyprogesterone acetate (MPA). A phase II trial demonstrated in vivo safety and efficacy of BEZ and MPA (BaP) in elderly, relapsed/refractory AML and high-risk myelodysplastic syndrome (MDS) patients. However, we observed dose-limiting toxicities in a second trial that attempted to improve outcomes via escalation of BaP doses. Thus we sought to identify a third repurposed drug that potentiates activity of low dose BaP (BaP 0.1 mM). METHODS AND RESULTS: We demonstrate that addition of a commonly used anti-epileptic, valproic acid (VAL) to low dose BaP (BaP 0.1 mM)(VBaP) enhanced killing of AML cell lines/primary AML cells to levels similar to high dose BaP (BaP 0.5 mM). Similarly, addition of VAL to BaP 0.1 mM enhanced reactive oxygen species (ROS), lipid peroxidation and inhibition of de novo fatty acid synthesis. Overexpression of Nrf2 in K562 and KG1a completely inhibited ROS production and rescued cells from VAL/BaP 0.1 mM/VBaP killing. CONCLUSIONS: Given the good safety data of low-dose BaP in elderly/relapsed/refractory AML patients, and that VAL alone is well-tolerated, we propose VBaP as a novel therapeutic combination for AML.

The effect of combined ß-lactoglobulin supplementation and resistance exercise training prior to limb immobilisation on muscle protein synthesis rates in healthy young adults: study protocol for a randomised controlled trial.

BACKGROUND: The decline in skeletal muscle mass experienced following a short-term period (days to weeks) of muscle disuse is mediated by impaired rates of muscle protein synthesis (MPS). Previous RCTs of exercise or nutrition prehabilitation interventions designed to mitigate disuse-induced muscle atrophy have reported limited efficacy. Hence, the aim of this study is to investigate the impact of a complex prehabilitation intervention that combines ß-lactoglobulin (a novel milk protein with a high leucine content) supplementation with resistance exercise training on disuse-induced changes in free-living integrated rates of MPS in healthy, young adults. METHODS/DESIGN: To address this aim, we will recruit 24 healthy young (18-45 years) males and females to conduct a parallel, double-blind, 2-arm, randomised placebo-controlled trial. The intervention group will combine a 7-day structured resistance exercise training programme with thrice daily dietary supplementation with 23 g of ß-lactoglobulin. The placebo group will combine the same training programme with an energy-matched carbohydrate (dextrose) control. The study protocol will last 16 days for each participant. Day 1 will be a familiarisation session and days 2-4 will be the baseline period. Days 5-11 represent the 'prehabilitation period' whereby participants will combine resistance training with their assigned dietary supplementation regimen. Days 12-16 represent the muscle disuse-induced 'immobilisation period' whereby participants will have a single leg immobilised in a brace and continue their assigned dietary supplementation regimen only (i.e. no resistance training). The primary endpoint of this study is the measurement of free-living integrated rates of MPS using deuterium oxide tracer methodology. Measurements of MPS will be calculated at baseline, over the 7-day prehabilitation period and over the 5-day immobilisation period separately. Secondary endpoints include measurements of muscle mass and strength that will be collected on days 4 (baseline), 11 (end of prehabilitation) and 16 (end of immobilisation). DISCUSSION: This novel study will establish the impact of a bimodal prehabilitation strategy that combines ß-lactoglobulin supplementation and resistance exercise training in modulating MPS following a short-term period of muscle disuse. If successful, this complex intervention may be translated to clinical practice with application to patients scheduled to undergo, for example, hip or knee replacement surgery. TRIAL REGISTRATION: NCT05496452. Registered on August 10, 2022. PROTOCOL VERSION: 16-12-2022/1.

The Epigenetic Regulatory Protein CBX2 Promotes mTORC1 Signalling and Inhibits DREAM Complex Activity to Drive Breast Cancer Cell Growth.

Chromobox 2 (CBX2) is a chromatin-binding component of polycomb repressive complex 1, which causes gene silencing. CBX2 expression is elevated in triple-negative breast cancer (TNBC), for which there are few therapeutic options. Here, we aimed to investigate the functional role of CBX2 in TNBC. CBX2 knockdown in TNBC models reduced cell numbers, which was rescued by ectopic expression of wild-type CBX2 but not a chromatin binding-deficient mutant. Blocking CBX2 chromatin interactions using the inhibitor SW2_152F also reduced cell growth, suggesting CBX2 chromatin binding is crucial for TNBC progression. RNA sequencing and gene set enrichment analysis of CBX2-depleted cells identified downregulation of oncogenic signalling pathways, including mTORC1 and E2F signalling. Subsequent analysis identified that CBX2 represses the expression of mTORC1 inhibitors and the tumour suppressor RBL2. RBL2 repression, in turn, inhibits DREAM complex activity. The DREAM complex inhibits E2F signalling, causing cell senescence; therefore, inhibition of the DREAM complex via CBX2 may be a key oncogenic driver. We observed similar effects in oestrogen receptor-positive breast cancer, and analysis of patient datasets suggested CBX2 inhibits RBL2 activity in other cancer types. Therapeutic inhibition of CBX2 could therefore repress mTORC1 activation and promote DREAM complex-mediated senescence in TNBC and could have similar effects in other cancer types.

An optimized metaproteomics protocol for a holistic taxonomic and functional characterization of microbial communities from marine particles.

This study aimed to establish a robust and reliable metaproteomics protocol for an in-depth characterization of marine particle-associated (PA) bacteria. To this end, we compared six well-established protein extraction protocols together with different MS-sample preparation techniques using particles sampled during a North Sea spring algae bloom in 2009. In the final optimized workflow, proteins are extracted using a combination of SDS-containing lysis buffer and cell disruption by bead-beating, separated by SDS-PAGE, in-gel digested and analysed by LC-MS/MS, before MASCOT search against a metagenome-based database and data processing/visualization with the in-house-developed bioinformatics tools Prophane and Paver. As an application example, free-living (FL) and particulate communities sampled in April 2009 were analysed, resulting in an as yet unprecedented number of 9354 and 5034 identified protein groups for FL and PA bacteria, respectively. Our data suggest that FL and PA communities appeared similar in their taxonomic distribution, with notable exceptions: eukaryotic proteins and proteins assigned to Flavobacteriia, Cyanobacteria, and some proteobacterial genera were found more abundant on particles, whilst overall proteins belonging to Proteobacteria were more dominant in the FL fraction. Furthermore, our data points to functional differences including proteins involved in polysaccharide degradation, sugar- and phosphorus uptake, adhesion, motility, and stress response.

Self-awareness of premalignant oral lesions among veterans attending six U.S. Veterans Affairs Medical Centers.

Early identification is key to reducing the morbidity and mortality of oropharyngeal cancer. This study identified factors associated with self-awareness among patients newly diagnosed with a premalignant oral lesion. Data describing sociodemographics, medical/dental histories, tobacco/alcohol use and oral health were obtained by questionnaire and clinical examination of 73 veterans at six U.S. Veterans Affairs Medical Centers. Lesion types included homogenous and non-homogenous leukoplakia, smokeless tobacco lesion (STL), papilloma, lichen planus and erythroplakia. Prior to diagnosis, 29 subjects (39.7%) were unaware of their lesion. In bivariate analyses, lesion self-awareness was associated with anatomic location, multifocal/generalized appearance, pain, oral sores, and cigar use (p<0.05). Awareness varied with lesion diagnosis and was more likely with STL and less likely with homogenous leukoplakia (p<0.05). In multivariate analyses, awareness was predicted by the presence of a lesion on easily visible mucosa (adjusted odds ratio, OR=11.2) and a history of mouth sores (OR= 11.2). These findings identified marked variations in patient self-awareness of oral premalignant conditions.

The association between oral health and general health and quality of life in older male cancer patients.

OBJECTIVES: To describe the long-term effects of oral health problems on quality of life (QoL), functional status, pain, and general health in older male cancer patients. DESIGN: Secondary analysis of a prospective observational study. SETTING: Community dwelling cancer patients served by a Department of Veterans Affairs hospital. PARTICIPANTS: One hundred fifty male cancer patients responded to the question "Do you have tooth or mouth problems making it hard to eat?" The relationship between patients answering "yes" and the following parameters was assessed: demographics, comorbid conditions, habits, activities of daily living, pain, anxiety, depression, social support, spirituality, QoL, and overall health ratings. MEASUREMENTS: Chi-square contingency tables for dichotomous variables, Cochran-Mantel-Haenszel for ordered categorical variables, and t tests for associations with continuous variables. RESULTS: The median age of respondents was 67. Those reporting tooth or mouth problems had had their cancer diagnosed on average 2.9 years before, and 83.3% were found clinically to be cancer free. Patients with these problems had significantly lower global (P=.003) and subscale scores on QoL analysis and higher levels of anxiety (P<.001) and depression (P=.01) than those without tooth or mouth problems; they also had significantly more pain (P<.001) and lower physical functioning (P<.001) and were more impaired in activities of daily living (P<.001). Those with tooth or mouth problems were more likely to describe their overall health as fair or poor (P=.01). Having cancer located in the head and neck region related significantly to having mouth or tooth problems (P=.005), but these problems were not associated with race, education, income, insurance coverage, age, comorbid conditions, alcohol consumption, tobacco or medication usage, type of cancer treatment, tumor stage at diagnosis or follow-up, perceived social support, or spirituality. CONCLUSION: Older male cancer patients with mouth or tooth problems making it hard to eat are more likely to have a lower QoL, poorer emotional health, lower levels of physical functioning, and greater pain than patients without these problems.

Inflammatory thyroid disorders.

Inflammatory thyroid disorders encompass a broad spectrum of diseases that are generally self-limited, and relatively easy to diagnose and manage. Autoimmune subtypes are by far the most commonly encountered diagnoses and create the most confusion because of simultaneous overlap and the potential for interconversion among the subtypes. The otolaryngologist will frequently see these disorders and provide valued consultative care and surgical intervention as needed.

Lessons from history: morbidity of cold injury in the Royal Marines during the Falklands Conflict of 1982.

BACKGROUND: Environmental conditions in the Falklands Conflict of 1982 favoured the genesis of cold injuries. Immediately, post-war, cold injury morbidity and its contributory factors were assessed, in the personnel of UK 3 Commando Brigade (3 Cdo Bde). METHODS: A questionnaire survey of the 3,006 members of 3 Cdo Bde who landed on the islands was conducted within 6-10 weeks of the end of hostilities. Questions included those relating to features of cold injury, body morphology, age, symptoms experienced, past medical history and other possible contributory causes. Additionally, the unit medical team conducted a cursory examination. Data were sent to the Royal Navy Institute of Naval Medicine (INM), where the degree of likely cold injury was broadly classified ('asymptomatic' 'mild', 'moderate' or 'severe'). A sample (total 109) was then selected at random from each category and subsequently examined and tested at the INM (nerve conduction, photoplethysmography and thermography testing). Forty-seven non-cold exposed sailors acted as a control group. These contemporaneous records have now been identified and interrogated. RESULTS: Some 2,354 (78%) completed questionnaires were returned, revealing that 1,505 (64%) had experienced symptoms of non-freezing cold injury. The morbidity in the infantry units was significantly greater than that in the support troops (1,051 (76%) vs 454 (46%), p < 0.05). No evidence was found to support an influence of a number of factors, commonly believed to have an aetiological role in the production of cold injury. Whilst there was no significant relationship between past history and cold injury morbidity in the brigade as a whole, or within the infantry units alone, an association was identified in the collective infantry units (73%) and the support/headquarter units (59%) (p < 0.05).In comparison with uninjured sailors who acted as controls (n = 47), nerve conduction was impaired in 35% of those screened some months after returning to the UK, while the photoplethysmography and thermographic responses to a cold sensitivity test showed that most (including those classed by questionnaire as asymptomatic) had residual 'cold sensitivity'. CONCLUSIONS: Although the passage of time has made retrospective interrogation of historical documents hard, the available data do appear to offer valuable historical and clinical insights. Cold injury affected the majority of those fighting in the cold temperate climate of the Falklands. The overwhelming environmental conditions meant that, for most, a past history of cold injury did not appear to represent a risk factor for subsequent injury, as is the case for less severe conditions. Importantly, even asymptomatic individuals when tested often showed physiological evidence of cold injury-perhaps predisposing them to subsequent elevation in risk.

Prevention and early detection of oral and pharyngeal cancer in veterans.

OBJECTIVES: To assess knowledge of oral and pharyngeal cancer (OPC) clinical signs and risk factors, the association between the risk factors and OPC, and the experience with OPC screening between newly diagnosed OPC patients and controls among a population of veterans in North Carolina. STUDY DESIGN: A case-control study with 31 OPC cases and 30 frequency-matched controls recruited from 2003 to 2004. Bivariate analysis using chi-square statistics and multivariate logistic regression was implemented to estimate the association with OPC. RESULTS: Only 34% of respondents knew 1 clinical sign and 4 or 5 risk factors for OPC. The lifetime accumulation of tobacco had a significant relationship with OPC (>20 pack-years; OR, 3.2; 95% CI, 1.01-10.3). Many respondents had not had an oral cancer examination within 3 years, mostly through ignorance. Most VA OPC patients were diagnosed by physicians, rather than by dentists. CONCLUSIONS: A considerable knowledge deficit on OPC was found among North Carolina veterans. Use of tobacco was a risk factor for OPC in this population.