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1.
Rheumatol Adv Pract ; 8(2): rkae046, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38690291

RESUMO

Objectives: Therapeutic advances in the management of osteoporosis and sarcopenia have occurred at different rates over the last 2 decades. Here we examine associations between grip strength and BMD with subsequent all-cause and cause-specific mortality in a UK community-dwelling cohort. Methods: Data from 495 men and 414 women from the Hertfordshire Cohort Study were analysed. Grip strength was assessed by grip dynamometry, femoral neck BMD was ascertained using DXA and deaths were recorded from baseline (1998-2004) until 31 December 2018. Grip strength and BMD in relation to mortality outcomes (all-cause, cardiovascular-related, cancer-related and mortality due to other causes) were examined using Cox regression with adjustment for age and sex. Results: The mean baseline age of participants was 64.3 years (s.d. 2.5) and 65.9 years (s.d. 2.6) in men and women, respectively. Lower grip strength was associated with increased risk of all-cause mortality [hazard ratio (HR) 1.30 (95% CI 1.06, 1.58), P = 0.010] and cardiovascular-related mortality [HR 1.75 (95% CI 1.20, 2.55), P = 0.004]. In contrast, BMD was not associated with any of the mortality outcomes (P > 0.1 for all associations). Conclusion: We report strong relationships between grip strength and mortality compared with BMD. We hypothesize that this may reflect better recognition and treatment of low BMD in this cohort.

2.
J Cachexia Sarcopenia Muscle ; 14(4): 1762-1774, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37199333

RESUMO

BACKGROUND: Amongst healthy older people, a number of correlates of impaired skeletal muscle mass and function have been defined. Although the prevalence of obesity is increasing markedly in this age group, information is sparse about the particular impacts of obesity on ageing skeletal muscle or the molecular mechanisms that underlie this and associated disease risk. METHODS: Here, we examined genome-wide transcriptional changes using RNA sequencing in muscle biopsies from 40 older community-dwelling men from the Hertfordshire Sarcopenia Study with regard to obesity (body mass index [BMI] >30 kg/m2 , n = 7), overweight (BMI 25-30, n = 19), normal weight (BMI < 25, n = 14), and per cent and total fat mass. In addition, we used EPIC DNA methylation array data to investigate correlations between DNA methylation and gene expression in aged skeletal muscle tissue and investigated the relationship between genes within altered regulatory pathways and muscle histological parameters. RESULTS: Individuals with obesity demonstrated a prominent modified transcriptional signature in muscle tissue, with a total of 542 differentially expressed genes associated with obesity (false discovery rate ≤0.05), of which 425 genes were upregulated when compared with normal weight. Upregulated genes were enriched in immune response (P = 3.18 × 10-41 ) and inflammation (leucocyte activation, P = 1.47 × 10-41 ; tumour necrosis factor, P = 2.75 × 10-15 ) signalling pathways and downregulated genes enriched in longevity (P = 1.5 × 10-3 ) and AMP-activated protein kinase (AMPK) (P = 4.5 × 10-3 ) signalling pathways. Furthermore, differentially expressed genes in both longevity and AMPK signalling pathways were associated with a change in DNA methylation, with a total of 256 and 360 significant cytosine-phosphate-guanine-gene correlations identified, respectively. Similar changes in the muscle transcriptome were observed with respect to per cent fat mass and total fat mass. Obesity was further associated with a significant increase in type II fast-fibre area (P = 0.026), of which key regulatory genes within both longevity and AMPK pathways were significantly associated. CONCLUSIONS: We provide for the first time a global transcriptomic profile of skeletal muscle in older people with and without obesity, demonstrating modulation of key genes and pathways implicated in the regulation of muscle function, changes in DNA methylation associated with such pathways and associations between genes within the modified pathways implicated in muscle regulation and changes in muscle fibre type.


Assuntos
Proteínas Quinases Ativadas por AMP , Adiposidade , Masculino , Humanos , Idoso , Adiposidade/genética , Regulação para Baixo , Proteínas Quinases Ativadas por AMP/metabolismo , Obesidade/complicações , Músculo Esquelético/metabolismo
3.
J Cachexia Sarcopenia Muscle ; 13(2): 858-871, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35174663

RESUMO

BACKGROUND: This trial aimed to determine the efficacy of leucine and/or perindopril in improving physical function in older people with sarcopenia. METHODS: Placebo-controlled, parallel group, double-blind, randomized two-by-two factorial trial. We recruited adults aged ≥ 70 years with sarcopenia, defined as low gait speed (<0.8 m/s on 4 m walk) and/or low handgrip strength (women < 20 kg, men < 30 kg) plus low muscle mass (using sex and body mass index category-specific thresholds derived from normative UK BioBank data) from 14 UK centres. Eligible participants were randomized to perindopril 4 mg or placebo, and to oral leucine powder 2.5 g or placebo thrice daily. The primary outcome was the between-group difference in the short physical performance battery (SPPB) score over 12-month follow-up by repeated-measures mixed models. Results were combined with existing systematic reviews using random-effects meta-analysis to derive summary estimates of treatment efficacy. RESULTS: We screened 320 people and randomized 145 participants compared with an original target of 440 participants. For perindopril [n = 73, mean age 79 (SD 6), female sex 39 (53%), mean SPPB 7.1 (SD 2.3)] versus no perindopril [n = 72, mean age 79 (SD 6), female sex 39 (54%), mean SPPB 6.9 (SD 2.4)], median adherence to perindopril was lower (76% vs. 96%; P < 0.001). Perindopril did not improve the primary outcome [adjusted treatment effect -0.1 points (95%CI -1.2 to 1.0), P = 0.89]. No significant treatment benefit was seen for any secondary outcome including muscle mass [adjusted treatment effect -0.4 kg (95%CI -1.1 to 0.3), P = 0.27]. More adverse events occurred in the perindopril group (218 vs. 165), but falls rates were similar. For leucine [n = 72, mean age 78 (SD 6), female sex 38 (53%), mean SPPB 7.0 (SD 2.1)] versus no leucine [n = 72, mean age 79 (SD 6), female sex 40 (55%), mean SPPB 7.0 (SD 2.5)], median adherence was the same in both groups (76% vs. 76%; P = 0.99). Leucine did not improve the primary outcome [adjusted treatment effect 0.1 point (95%CI -1.0 to 1.1), P = 0.90]. No significant treatment benefit was seen for any secondary outcome including muscle mass [adjusted treatment effect -0.3 kg (95%CI -1.0 to 0.4), P = 0.47]. Meta-analysis of angiotensin converting enzyme inhibitor/angiotensin receptor blocker trials showed no clinically important treatment effect for the SPPB [between-group difference -0.1 points (95%CI -0.4 to 0.2)]. CONCLUSIONS: Neither perindopril nor leucine improved physical performance or muscle mass in this trial; meta-analysis did not find evidence of efficacy of either ACE inhibitors or leucine as treatments to improve physical performance.


Assuntos
Leucina , Perindopril , Desempenho Físico Funcional , Sarcopenia , Idoso , Feminino , Força da Mão/fisiologia , Humanos , Leucina/uso terapêutico , Masculino , Metanálise como Assunto , Perindopril/uso terapêutico , Sarcopenia/tratamento farmacológico , Sarcopenia/fisiopatologia , Resultado do Tratamento
4.
J Cachexia Sarcopenia Muscle ; 13(1): 220-229, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34873876

RESUMO

BACKGROUND: Ageing is commonly associated with sarcopenia (SP) and osteoporosis (OP), both of which are associated with disability, impaired quality of life, and mortality. The aims of this study were to explore the relationships between SP, OP, frailty, and multimorbidity in community-dwelling older adults participating in the Hertfordshire Cohort Study (HCS) and to determine whether coexistence of OP and SP was associated with a significantly heavier health burden. METHODS: At baseline, 405 participants self-reported their comorbidities. Cut-offs for low grip strength and appendicular lean mass index were used according to the EWSGOP2 criteria to define SP. OP was diagnosed when T-scores of < -2.5 were present at the femoral neck or the participant reported use of the anti-OP medications including hormone replacement therapy (HRT), raloxifene, or bisphosphonates. Frailty was defined using the standard Fried definition. RESULTS: One hundred ninety-nine men and 206 women were included in the study. Baseline median (interquartile range) age of participants was 75.5 (73.4-77.9) years. Twenty-six (8%) and 66 (21.4%) of the participants had SP and OP, respectively. Eighty-three (20.5%) reported three or more comorbidities. The prevalence of pre-frailty and frailty in the study sample was 57.5% and 8.1%, respectively. Having SP only was strongly associated with frailty [odds ratio (OR) 8.28, 95% confidence interval (CI) 1.27, 54.03; P = 0.027] while the association between having OP alone and frailty was weaker (OR 2.57, 95% CI 0.61, 10.78; P = 0.196). The likelihood of being frail was substantially higher in the presence of coexisting SP and OP (OR 26.15, 95% CI 3.13, 218.76; P = 0.003). SP alone and OP alone were both associated with having three or more comorbidities (OR 4.71, 95% CI 1.50, 14.76; P = 0.008 and OR 2.86, 95% CI 1.32, 6.22; P = 0.008, respectively) although the coexistence of SP and OP was not significantly associated with multimorbidity (OR 3.45, 95% CI 0.59, 20.26; P = 0.171). CONCLUSIONS: Individuals living with frailty were often osteosarcopenic. Multimorbidity was common in individuals with either SP or OP. Early identification of SP and OP not only allows implementation of treatment strategies but also presents an opportunity to mitigate frailty risk.


Assuntos
Fragilidade , Osteoporose , Sarcopenia , Idoso , Estudos de Coortes , Feminino , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Humanos , Masculino , Multimorbidade , Osteoporose/epidemiologia , Qualidade de Vida , Sarcopenia/diagnóstico
5.
J Cachexia Sarcopenia Muscle ; 13(1): 240-253, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34862756

RESUMO

BACKGROUND: Sarcopenia is the age-related loss of muscle mass, strength, and function. Epigenetic processes such as DNA methylation, which integrate both genetic and environmental exposures, have been suggested to contribute to the development of sarcopenia. This study aimed to determine whether differences in the muscle methylome are associated with sarcopenia and its component measures: grip strength, appendicular lean mass index (ALMi), and gait speed. METHODS: Using the Infinium Human MethylationEPIC BeadChip, we measured DNA methylation in vastus lateralis muscle biopsies of 83 male participants (12 with sarcopenia) with a mean (standard deviation) age of 75.7 (3.6) years from the Hertfordshire Sarcopenia Study (HSS) and Hertfordshire Sarcopenia Study extension (HSSe) and examined associations with sarcopenia and its components. Pathway, histone mark, and transcription factor enrichment of the differentially methylated CpGs (dmCpGs) were determined, and sodium bisulfite pyrosequencing was used to validate the sarcopenia-associated dmCpGs. Human primary myoblasts (n = 6) isolated from vastus lateralis muscle biopsies from male individuals from HSSe were treated with the EZH2 inhibitor GSK343 to assess how perturbations in epigenetic processes may impact myoblast differentiation and fusion, measured by PAX7 and MYHC immunocytochemistry, and mitochondrial bioenergetics determined using the Seahorse XF96. RESULTS: Sarcopenia was associated with differential methylation at 176 dmCpGs (false discovery rate ≤ 0.05) and 141 differentially methylated regions (Stouffer ≤ 0.05). The sarcopenia-associated dmCpGs were enriched in genes associated with myotube fusion (P = 1.40E-03), oxidative phosphorylation (P = 2.78E-02), and voltage-gated calcium channels (P = 1.59E-04). ALMi was associated with 71 dmCpGs, grip strength with 49 dmCpGs, and gait speed with 23 dmCpGs (false discovery rate ≤ 0.05). There was significant overlap between the dmCpGs associated with sarcopenia and ALMi (P = 3.4E-35), sarcopenia and gait speed (P = 4.78E-03), and sarcopenia and grip strength (P = 7.55E-06). There was also an over-representation of the sarcopenia, ALMi, grip strength, and gait speed-associated dmCpGs with sites of H3K27 trimethylation (all P ≤ 0.05) and amongst EZH2 target genes (all P ≤ 0.05). Furthermore, treatment of human primary myoblasts with the EZH2 inhibitor GSK343 inhibitor led to an increase in PAX7 expression (P ≤ 0.05), decreased myotube fusion (P = 0.043), and an increase in ATP production (P = 0.008), with alterations in the DNA methylation of genes involved in oxidative phosphorylation and myogenesis. CONCLUSIONS: These findings show that differences in the muscle methylome are associated with sarcopenia and individual measures of muscle mass, strength, and function in older individuals. This suggests that changes in the epigenetic regulation of genes may contribute to impaired muscle function in later life.


Assuntos
Epigenoma , Sarcopenia , Idoso , Metilação de DNA , Epigênese Genética , Força da Mão/fisiologia , Humanos , Masculino , Sarcopenia/genética
6.
Geriatrics (Basel) ; 5(4)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33126470

RESUMO

Multi-morbidity and polypharmacy are common in older people and pose a challenge for health and social care systems, especially in the context of global population ageing. They are complex and interrelated concepts in the care of older people that require early detection and patient-centred shared decision making underpinned by multi-disciplinary team-led comprehensive geriatric assessment (CGA) across all health and social care settings. Personalised care plans need to remain responsive and adaptable to the needs and wishes of the patient, enabling the individual to maintain their independence. In this review, we aim to give an up-to-date account of the recognition and management of multi-morbidity and polypharmacy in the older person.

7.
Nat Commun ; 10(1): 5808, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31862890

RESUMO

The causes of impaired skeletal muscle mass and strength during aging are well-studied in healthy populations. Less is known on pathological age-related muscle wasting and weakness termed sarcopenia, which directly impacts physical autonomy and survival. Here, we compare genome-wide transcriptional changes of sarcopenia versus age-matched controls in muscle biopsies from 119 older men from Singapore, Hertfordshire UK and Jamaica. Individuals with sarcopenia reproducibly demonstrate a prominent transcriptional signature of mitochondrial bioenergetic dysfunction in skeletal muscle, with low PGC-1α/ERRα signalling, and downregulation of oxidative phosphorylation and mitochondrial proteostasis genes. These changes translate functionally into fewer mitochondria, reduced mitochondrial respiratory complex expression and activity, and low NAD+ levels through perturbed NAD+ biosynthesis and salvage in sarcopenic muscle. We provide an integrated molecular profile of human sarcopenia across ethnicities, demonstrating a fundamental role of altered mitochondrial metabolism in the pathological loss of skeletal muscle mass and function in older people.


Assuntos
Envelhecimento/fisiologia , Mitocôndrias/patologia , Músculo Esquelético/patologia , NAD/biossíntese , Sarcopenia/patologia , Idoso , Idoso de 80 Anos ou mais , Biópsia , Estudos de Casos e Controles , Metabolismo Energético/fisiologia , Humanos , Jamaica , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Oxirredução , Fosforilação Oxidativa , Estresse Oxidativo/fisiologia , Proteostase , Sarcopenia/etnologia , Singapura , Reino Unido
8.
Geriatrics (Basel) ; 3(3)2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31011074

RESUMO

Background: Giant cell arteritis/temporal arteritis (GCA) is an inflammatory condition that affects large to medium vessels such as the aorta and its primary branches. Patients classically present with fatigue, fever, headache, jaw claudication and in severe cases, may suffer either transient (amaurosis fugax) or permanent visual loss. The reference standard for diagnosis is the temporal artery biopsy (TAB) and the mainstay of treatment is with immunosuppression. Our patient JG, presented with a range of non-specific symptoms that mimicked generalised sepsis, but was ultimately diagnosed with GCA through effective, methodical multi-disciplinary team (MDT) work. Clinical case: JG, an 81 year old gentleman, presented acutely with a 3-4 weeks history of fatigue, lethargy, pyrexia and a marked inflammatory response suggestive of a sepsis but without a clear primary source or clinical features of vasculitis. His inflammatory markers were markedly raised although his erythrocyte sedimentation rate (ESR) was not elevated. He was initially treated for sepsis of unknown origin however, body imaging after admission suggested a possible infection around a previous aortic graft site. This was refuted in subsequent 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET/CT) scanning. Microbiological, parasitic, as well as autoimmune assays were unremarkable. He underwent a TAB which was diagnostic for GCA and as a result, was started on oral corticosteroids with immediate symptom relief. He was discharged and followed up on an outpatient basis. Conclusions: This case highlights how a vasculitis can present with a range of non-specific symptoms that may resemble a fever of unknown origin (FUO)/sepsis that can lead to a delay in making the correct diagnosis. It also highlights the importance of considering a diagnosis of vasculitis in patients who present with a FUO where there is no clear focus of infection. Delays in diagnosis and management of these conditions can potentially lead to significant irreversible morbidity.

9.
J Cachexia Sarcopenia Muscle ; 9(2): 400-416, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29215200

RESUMO

BACKGROUND: A loss of muscle mass occurs as a consequence of a range of chronic and acute diseases as well as in older age. This wasting results from an imbalance of protein synthesis and degradation with a reduction in synthesis and resistance to anabolic stimulation often reported features. Ribosomes are required for protein synthesis, so changes in the control of ribosome synthesis are potential contributors to muscle wasting. MicroRNAs (miRNAs) are known regulators of muscle phenotype and have been shown to modulate components of the protein synthetic pathway. One miRNA that is predicted to target a number of components of protein synthetic pathway is miR-424-5p, which is elevated in the quadriceps of patients with chronic obstructive pulmonary disease (COPD). METHODS: Targets of miR-424-5p were identified by Argonaute2 pull down, and the effects of the miRNA on RNA and protein expression were determined by quantitative polymerase chain reaction and western blotting in muscle cells in vitro. Protein synthesis was determined by puromycin incorporation in vitro. The miRNA was over-expressed in the tibialis anterior muscle of mice by electroporation and the effects quantified. Finally, quadriceps expression of the miRNA was determined by quantitative polymerase chain reaction in patients with COPD and intensive care unit (ICU)-acquired weakness and in patients undergoing aortic surgery as well as in individuals from the Hertfordshire Sarcopenia Study. RESULTS: Pull-down assays showed that miR-424-5p bound to messenger RNAs encoding proteins associated with muscle protein synthesis. The most highly enriched messenger RNAs encoded proteins required for the Pol I RNA pre-initiation complex required for ribosomal RNA (rRNA) transcription, (PolR1A and upstream binding transcription factor). In vitro, miR-424-5p reduced the expression of these RNAs, reduced rRNA levels, and inhibited protein synthesis. In mice, over-expression of miR-322 (rodent miR-424 orthologue) caused fibre atrophy and reduced upstream binding transcription factor expression and rRNA levels. In humans, elevated miR-424-5p associated with markers of disease severity in COPD (FEV1 %), in patients undergoing aortic surgery (LVEF%), and in patients with ICU-acquired weakness (days in ICU). In patients undergoing aortic surgery, preoperative miR-424-5p expression in skeletal muscle was associated with muscle loss over the following 7 days. CONCLUSIONS: These data suggest that miR-424-5p regulates rRNA synthesis by inhibiting Pol I pre-initiation complex formation. Increased miR-424-5p expression in patients with conditions associated with muscle wasting is likely to contribute to the inhibition of protein synthesis and loss of muscle mass.


Assuntos
MicroRNAs/metabolismo , Atrofia Muscular/metabolismo , RNA Ribossômico/metabolismo , Animais , Linhagem Celular , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Atrofia Muscular/genética , Biossíntese de Proteínas , RNA Ribossômico/genética , Transfecção
10.
BMC Med Res Methodol ; 17(1): 167, 2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-29233101

RESUMO

BACKGROUND: Recruitment rates of older people in epidemiological studies, although relatively higher than in clinical trials, have declined in recent years. This study aimed to explore motivating factors and concerns among older participants in an intensive epidemiological study (Hertfordshire Sarcopenia Study - HSS) and identify those that could aid future recruitment to epidemiological studies and clinical trials. METHODS: Participants of the HSS fasted overnight and travelled several hours each way to the research facility at an English hospital for extensive diet/lifestyle questionnaires and investigations to assess muscle including blood tests and a muscle biopsy. We conducted semi-structured interviews with 13 participants (ten women) at the research facility in May-October 2015. The interviews were audio-taped, transcribed verbatim, coded and analysed thematically by three researchers. RESULTS: We identified personal motives for participation (potential health benefit for self and family; curiosity; comparing own fitness to others; socialising). Altruistic motives (benefit for other people; belief in importance of research) were also important. Participants voiced a number of external motives related to the study uniqueness, organisation and safety record; family support; and just 'being asked'. Anxiety about the biopsy and travel distance were the only concerns and were alleviated by smooth and efficient running of the study. CONCLUSIONS: Personal and altruistic reasons were important motivators for these older people to participate in demanding, intensive research. They valued belonging to a birth cohort with previous research experience, but personal contact with the research team before and after consent provided reassurance, aided recruitment to HSS and could be readily replicated by other researchers. Any fears or concerns related to certain aspects of a demanding, intensive study should ideally be explored at an early visit to establish a good relationship with the research team.


Assuntos
Estudos Epidemiológicos , Idoso , Idoso de 80 Anos ou mais , Tomada de Decisões , Feminino , Humanos , Masculino , Motivação , Participação do Paciente , Seleção de Pacientes , Pesquisa Qualitativa
11.
J Cachexia Sarcopenia Muscle ; 7(3): 330-44, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27239417

RESUMO

BACKGROUND: Loss of muscle mass and strength is a significant comorbidity in patients with chronic obstructive pulmonary disease (COPD) that limits their quality of life and has prognostic implications but does not affect everyone equally. To identify mechanisms that may contribute to the susceptibility to a low muscle mass, we investigated microRNA (miRNA) expression, methylation status, and regeneration in quadriceps muscle from COPD patients and the effect of miRNAs on myoblast proliferation in vitro. The relationships of miRNA expression with muscle mass and strength was also determined in a group of healthy older men. METHODS: We identified miRNAs associated with a low fat-free mass (FFM) phenotype in a small group of patients with COPD using a PCR screen of 750 miRNAs. The expression of two differentially expressed miRNAs (miR-675 and miR-519a) was determined in an expanded group of COPD patients and their associations with FFM and strength identified. The association of these miRNAs with FFM and strength was also explored in a group of healthy community-dwelling older men. As the expression of the miRNAs associated with FFM could be regulated by methylation, the relative methylation of the H19 ICR was determined. Furthermore, the proportion of myofibres with centralized nuclei, as a marker of muscle regeneration, in the muscle of COPD patients was identified by immunofluorescence. RESULTS: Imprinted miRNAs (miR-675 and from a cluster, C19MC which includes miR-519a) were differentially expressed in the quadriceps of patients with a low fat-free mass index (FFMI) compared to those with a normal FFMI. In larger cohorts, miR-675 and its host gene (H19) were higher in patients with a low FFMI and strength. The association of miR-519a expression with FFMI was present in male patients with severe COPD. Similar associations of miR expression with lean mass and strength were not observed in healthy community dwelling older men participating in the Hertfordshire Sarcopenia Study. Relative methylation of the H19 ICR was reduced in COPD patients with muscle weakness but was not associated with FFM. In vitro, miR-675 inhibited myoblast proliferation and patients with a low FFMI had fewer centralized nuclei suggesting miR-675 represses regeneration. CONCLUSIONS: The data suggest that increased expression of miR-675/H19 and altered methylation of the H19 imprinting control region are associated with a low FFMI in patients with COPD but not in healthy community dwelling older men suggesting that epigenetic control of this loci may contribute to a susceptibility to a low FFMI.

12.
J Vis Exp ; (109): e53075, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26967381

RESUMO

Percutaneous muscle biopsy using the Weil-Blakesley conchotome is well established in both clinical and research practice. It is a safe, effective and well tolerated technique. The Weil-Blakesley conchotome has a sharp biting tip with a 4 - 6 mm wide hollow. It is inserted through a 5 - 10 mm skin incision and can be maneuvered for controlled tissue penetration. The tip is opened and closed within the tissue and then rotated through 90 -180° to cut the muscle. The amount of muscle obtained following repeated sampling can vary from 20 mg to 290 mg which can be processed for both histology and molecular studies. The wound needs to be kept dry and vigorous physical activity kept to a minimum for approximately 72 hr although normal levels of activity can restart immediately following the procedure. This procedure is safe and effective when close attention is paid to the selection of subjects, full asepsis and post procedure care.  Both right and left vastus lateralis are suitable for biopsy dependent on participant preference.


Assuntos
Biópsia/métodos , Músculo Quadríceps/cirurgia , Humanos
13.
Calcif Tissue Int ; 95(4): 308-16, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25055749

RESUMO

Sarcopenia is associated with adverse health outcomes. This study investigated whether skeletal muscle gene expression was associated with lean mass and grip strength in community-dwelling older men. Utilising a cross-sectional study design, lean muscle mass and grip strength were measured in 88 men aged 68-76 years. Expression profiles of 44 genes implicated in the cellular regulation of skeletal muscle were determined. Serum was analysed for circulating cytokines TNF (tumour necrosis factor), IL-6 (interleukin 6, IFNG (interferon gamma), IL1R1 (interleukin-1 receptor-1). Relationships between skeletal muscle gene expression, circulating cytokines, lean mass and grip strength were examined. Participant groups with higher and lower values of lean muscle mass (n = 18) and strength (n = 20) were used in the analysis of gene expression fold change. Expression of VDR (vitamin D receptor) [fold change (FC) 0.52, standard error for fold change (SE) ± 0.08, p = 0.01] and IFNG mRNA (FC 0.31; SE ± 0.19, p = 0.01) were lower in those with higher lean mass. Expression of IL-6 (FC 0.43; SE ± 0.13, p = 0.02), TNF (FC 0.52; SE ± 0.10, p = 0.02), IL1R1 (FC 0.63; SE ± 0.09, p = 0.04) and MSTN (myostatin) (FC 0.64; SE ± 0.11, p = 0.04) were lower in those with higher grip strength. No other significant changes were observed. Significant negative correlations between serum IL-6 (R = -0.29, p = 0.005), TNF (R = -0.24, p = 0.017) and grip strength were demonstrated. This novel skeletal muscle gene expression study carried out within a well-characterized epidemiological birth cohort has demonstrated that lower expression of VDR and IFNG is associated with higher lean mass, and lower expression of IL-6, TNF, IL1R1 and myostatin is associated with higher grip strength. These findings are consistent with a role of proinflammatory factors in mediating lower muscle strength in community-dwelling older men.


Assuntos
Regulação da Expressão Gênica , Sarcopenia/patologia , Idoso , Antropometria , Biópsia , Composição Corporal , Estudos de Coortes , Estudos Transversais , Inglaterra , Perfilação da Expressão Gênica , Humanos , Interferon gama/metabolismo , Interleucina-6/metabolismo , Masculino , Pessoa de Meia-Idade , Força Muscular , Músculo Esquelético/metabolismo , Miostatina/metabolismo , Reação em Cadeia da Polimerase , Receptores Tipo I de Interleucina-1/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
14.
J Bone Miner Res ; 28(11): 2295-304, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23633238

RESUMO

Sarcopenia is associated with a greater fracture risk. This relationship was originally thought to be explained by an increased risk of falls in sarcopenic individuals. However, in addition, there is growing evidence of a functional muscle-bone unit in which bone health may be directly influenced by muscle function. Because a definition of sarcopenia encompasses muscle size, strength, and physical performance, we investigated relationships for each of these with bone size, bone density, and bone strength to interrogate these hypotheses further in participants from the Hertfordshire Cohort Study. A total of 313 men and 318 women underwent baseline assessment of health and detailed anthropometric measurements. Muscle strength was measured by grip strength, and physical performance was determined by gait speed. Peripheral quantitative computed tomography (pQCT) examination of the calf and forearm was performed to assess muscle cross-sectional area (mCSA) at the 66% level and bone structure (radius 4% and 66% levels; tibia 4% and 38% levels). Muscle size was positively associated with bone size (distal radius total bone area ß = 17.5 mm2 /SD [12.0, 22.9]) and strength (strength strain index (ß = 23.3 mm3 /SD [18.2, 28.4]) amongst women (p < 0.001). These associations were also seen in men and were maintained after adjustment for age, height, weight-adjusted-for-height, limb-length-adjusted-for-height, social class, smoking status, alcohol consumption, calcium intake, physical activity, diabetes mellitus, and in women, years since menopause and estrogen replacement therapy. Although grip strength showed similar associations with bone size and strength in both sexes, these were substantially attenuated after similar adjustment. Consistent relationships between gait speed and bone structure were not seen. We conclude that although muscle size and grip strength are associated with bone size and strength, relationships between gait speed and bone structure and strength were not apparent in this cohort, supporting a role for the muscle-bone unit.


Assuntos
Osso e Ossos/anatomia & histologia , Atividade Motora/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Idoso , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/fisiologia , Estudos de Coortes , Feminino , Marcha/fisiologia , Força da Mão/fisiologia , Humanos , Masculino , Músculo Esquelético/diagnóstico por imagem , Tamanho do Órgão , Tomografia Computadorizada por Raios X , Reino Unido
15.
J Nutr Health Aging ; 15(1): 10-5, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21267515

RESUMO

BACKGROUND: Sarcopenia, the loss of muscle mass and strength, is associated adversely with disability, morbidity and mortality. Epidemiological findings suggest influences operating across the life course may be important. Our aim was to ascertain the feasibility and acceptability of obtaining muscle tissue from healthy older people in order to ultimately identify cellular mechanisms underlying life course influences on sarcopenia. METHODS: 105 men with documented birth weight consented to detailed assessment of muscle mass and strength, and a biopsy of the vastus lateralis using the Weil-Blakesley conchotome. Acceptability was ascertained by questionnaire and a 100 mm pain Visual Analogue Scale (VAS). 100 mm indicated severe pain. RESULTS: Muscle biopsy was successfully carried out in 102 out of 105 participants, mean yield 107 mg (range 20-290 mg). There were no serious wound complications. Ninety-three participants completed feedback questionnaires. The median pain VAS score during the procedure was 7 mm (Interquartile range [IQR] 1-34), 4 mm (IQR 0-16) one day after the procedure and 1mm (IQR 0-4) 7 days after the procedure. 60 (65%) participants were back to their normal levels of activity one day after the procedure. 85 (91%) found this procedure acceptable and would have the procedure again. CONCLUSION: Muscle biopsy using a Weil-Blakesley conchotome is both feasible and acceptable in community dwelling older men participating in epidemiological research. The excellent yield of biopsy tissue will allow morphological and molecular studies of muscle to be integrated into an epidemiological study facilitating investigation of the mechanisms underpinning sarcopenia that could potentially be altered by life course influences.


Assuntos
Métodos Epidemiológicos , Dor/etiologia , Músculo Quadríceps/patologia , Sarcopenia/patologia , Idoso , Biópsia/efeitos adversos , Biópsia/instrumentação , Biópsia/métodos , Estudos de Viabilidade , Humanos , Masculino , Força Muscular , Medição da Dor , Aceitação pelo Paciente de Cuidados de Saúde , Valores de Referência , Sarcopenia/complicações , Inquéritos e Questionários
16.
Hosp Pract (1995) ; 38(3): 117-21, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20890060

RESUMO

Meningeal carcinomatosis (MC) from cervical cancer is rare. Diagnosis of this disease is often delayed due to variable presentation. We report an interesting case of MC from the uterine cervix and review general diagnostic and treatment considerations. The patient received chemotherapy and radiotherapy for stage IIB cervical cancer with resolution of symptoms for 3 years. Metastatic lesions were found in the right lung and paraaotic nodes on follow-up positron emission tomography scan, which completely resolved with subsequent chemotherapy. Unfortunately, the patient developed neurological symptoms consistent with MC, which was confirmed by cerebrospinal fluid cytology. Because of her poor cognition, available options were discussed with her family. She died peacefully in palliative care.


Assuntos
Carcinomatose Meníngea/secundário , Neoplasias de Células Escamosas/secundário , Neoplasias do Colo do Útero/patologia , Idoso , Feminino , Humanos , Carcinomatose Meníngea/terapia , Neoplasias de Células Escamosas/patologia
17.
BMC Geriatr ; 10: 43, 2010 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-20587018

RESUMO

BACKGROUND: Sarcopenia is defined as the loss of muscle mass and strength with age. Although a number of adult influences are recognised, there remains considerable unexplained variation in muscle mass and strength between older individuals. This has focused attention on influences operating earlier in life. Our objective for this study was to identify life course influences on muscle mass and strength in an established birth cohort and develop methodology for collection of muscle tissue suitable to investigate underlying cellular and molecular mechanisms. METHODS: One hundred and five men from the Hertfordshire Cohort Study (HCS), born between 1931 and 1939 who have historical records of birth weight and weight at one year took part in the Hertfordshire Sarcopenia Study (HSS). Each participant consented for detailed characterisation of muscle mass, muscle function and aerobic capacity. In addition, a muscle biopsy of the vastus lateralis using a Weil-Blakesley conchotome was performed. Data on muscle mass, function and aerobic capacity was collected on all 105 participants. Muscle biopsy was successfully carried out in 102 participants with high rates of acceptability. No adverse incidents occurred during the study. DISCUSSION: The novel approach of combining epidemiological and basic science characterisation of muscle in a well established birth cohort will allow the investigation of cellular and molecular mechanisms underlying life course influences on sarcopenia.


Assuntos
Envelhecimento/patologia , Músculo Esquelético/patologia , Sarcopenia/patologia , Idoso , Envelhecimento/fisiologia , Biópsia/métodos , Estudos de Coortes , Inglaterra/epidemiologia , Força da Mão/fisiologia , Humanos , Masculino , Músculo Esquelético/fisiologia , Estudos Retrospectivos , Sarcopenia/epidemiologia , Sarcopenia/fisiopatologia
18.
Am J Physiol Renal Physiol ; 294(6): F1354-65, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18385271

RESUMO

Erythropoietin (Epo) induces erythrocytosis by suppressing erythroid progenitor cell apoptosis through the Janus-activated kinase-signal transducers and activators of transcription (JAK-STAT) pathway. Since apoptosis contributes to cisplatin (CP)-induced nephrotoxicity and Epo receptors (EpoR) are expressed in the kidney, we examined the role of antiapoptosis in recombinant human erythropoietin (rHuEpo)-mediated renal protection. In human renal proximal tubular epithelial (RPTE) cells in culture, rHuEpo, but not inactive rHuEpo (I-rHuEpo), the receptor-binding sites of which are mutated, caused a significant reduction in CP-induced apoptosis at > or = 100 U/ml. rHuEpo, but not I-rHuEpo, increased STAT5 and Akt/PKB phosphorylation, demonstrating functional EpoR expression on RPTE cells. Furthermore, the JAK2 inhibitor tyrphostin AG-490 attenuated rHuEpo protection, suggesting a role of the JAK-STAT pathway in rHuEpo-mediated antiapoptosis. In rats, intravenous administration of 5,000 U/kg rHuEpo, but not an equivalent peptide mass of I-rHuEpo, before a single 5.5 mg/kg iv injection of CP, significantly increased hematocrit (Hct) and reduced the CP-induced increase in serum creatinine. Serum creatinine on day 4 was 3.4 +/- 0.3, 1.9 +/- 0.3, and 3.5 +/- 0.4 mg/dl in the CP, CP + rHuEpo, and CP + I-rHuEpo groups, respectively. Similarly, darbepoietin-alpha (DA), a hyperglycosylated analog of rHuEpo with prolonged in vivo activity when injected at 25 microg/kg iv before CP, significantly increased Hct and reduced serum creatinine. Renal clearance studies based on glomerular filtration rate and renal blood flow confirmed the significant renal protection by DA against CP. Tubular apoptosis and necrosis were significantly reduced in the kidneys of the CP + DA vs. the CP + saline group. Moreover, the equalization of Hct by venesection did not abrogate the DA-mediated renal protection. Administration of DA 48 h after CP injection also conferred significant renal protection. Thus our experiments confirm a role for erythropoiesis-stimulating proteins, including the new analog DA, in limiting CP-induced nephrotoxicity and suggest that antiapoptosis via the Epo-EpoR interaction is an important mechanism for renal protection.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Cisplatino/toxicidade , Eritropoetina/farmacologia , Injúria Renal Aguda/patologia , Animais , Células Cultivadas , Darbepoetina alfa , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Eritropoetina/análogos & derivados , Eritropoetina/metabolismo , Hematínicos/metabolismo , Hematínicos/farmacologia , Hematócrito , Humanos , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/metabolismo , Rim/citologia , Masculino , Necrose/metabolismo , Necrose/patologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores da Eritropoetina/metabolismo , Proteínas Recombinantes , Fator de Transcrição STAT5/metabolismo , Tirfostinas/farmacologia
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