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1.
Front Neurol ; 14: 1229681, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37941576

RESUMO

The aim of this prospective observational longitudinal study was to explore and decipher the predictive value of prospective MRI biomarkers in the brain and lower limb muscles for 3-month lower limb motor recovery following stroke. In the brain, we measured the integrity of the corticospinal tract (fractional anisotropy/"FA"). In the muscles, we measured volume, fatty replacement (fat fraction analysis and proton spectroscopy) and oedema. Measurements were taken at two time points: (1) within 4 weeks of stroke (baseline measurement, clinical and imaging) and (2) 3 months following stroke (follow up measurement, clinical only). Clinical measurements consisted of assessments of functional ability and strength (Fugl-Meyer score, motor NIHSS, Functional Ambulation Category/"FAC", and muscle dynamometry). Twenty-three patients completed imaging and clinical assessments at baseline and follow-up; five patients had partial imaging assessment. The results provided some evidence that damage to the corticospinal tract would result in less motor recovery: recovery of the Fugl-Meyer score and dynamometric ankle plantarflexion, ankle dorsiflexion, and knee extension correlated positively and significantly with fractional anisotropy (0.406-0.457; p = 0.034-p = 0.016). However, fractional anisotropy demonstrated a negative correlation with recovery of the Functional Ambulation Category (-0.359, p = 0.046). For the muscle imaging, significant inverse correlation was observed between vastus lateralis fat fraction vs. NIHSS recovery (-0.401, p = 0.04), and a strong positive correlation was observed between ratio of intra- to extra-myocellular lipid concentrations and the recovery of knee flexion (0.709, p = 0.007). This study supports previous literature indicating a positive correlation between the integrity of the corticospinal tract and motor recovery post-stroke, expanding the limited available literature describing this relationship specifically for the lower limb. However, recovery of functional ambulation behaved differently to other clinical recovery markers by demonstrating an inverse relationship with corticospinal tract integrity. The study also introduces some muscle imaging biomarkers as potentially valuable in the prediction of 3-month lower limb motor recovery following stroke.

2.
J Cachexia Sarcopenia Muscle ; 13(6): 2888-2897, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36058852

RESUMO

BACKGROUND: Water T2 (T2H2O ) mapping is increasingly being used in muscular dystrophies to assess active muscle damage. It has been suggested as a surrogate outcome measure for clinical trials. Here, we investigated the prognostic utility of T2H2O to identify changes in muscle function over time in limb girdle muscular dystrophies. METHODS: Patients with genetically confirmed dysferlinopathy were assessed as part of the Jain Foundation Clinical Outcomes Study in dysferlinopathy. The cohort included 18 patients from two sites, both equipped with 3-tesla magnetic resonance imaging (MRI) systems from the same vendor. T2H2O value was defined as higher or lower than the median in each muscle bilaterally. The degree of deterioration on four functional tests over 3 years was assessed in a linear model against covariates of high or low T2H2O at baseline, age, disease duration, and baseline function. RESULTS: A higher T2H2O at baseline significantly correlated with a greater decline on functional tests in 21 out of 35 muscles and was never associated with slower decline. Higher baseline T2H2O in adductor magnus, vastus intermedius, vastus lateralis, and vastus medialis were the most sensitive, being associated bilaterally with greater decline in multiple timed tests. Patients with a higher than median baseline T2H2O (>40.6 ms) in the right vastus medialis deteriorated 11 points more on the North Star Ambulatory Assessment for Dysferlinopathy and lost an additional 86 m on the 6-min walk than those with a lower T2H2O (<40.6 ms). Optimum sensitivity and specificity thresholds for predicting decline were 39.0 ms in adductor magnus and vastus intermedius, 40.0 ms in vastus medialis, and 40.5 ms in vastus lateralis from different sites equipped with different MRI systems. CONCLUSIONS: In dysferlinopathy, T2H2O did not correlate with current functional ability. However, T2H2O at baseline was higher in patients who worsened more rapidly on functional tests. This suggests that inter-patient differences in functional decline over time may be, in part, explained by different severities of the active muscle damage, assessed by T2H2O measure at baseline. Significant challenges remain in standardizing T2H2O values across sites to allow determining globally applicable thresholds. The results from the present work are encouraging and suggest that T2H2O could be used to improve prognostication, patient selection, and disease modelling for clinical trials.


Assuntos
Distrofia Muscular do Cíngulo dos Membros , Distrofias Musculares , Humanos , Água , Distrofia Muscular do Cíngulo dos Membros/diagnóstico , Distrofia Muscular do Cíngulo dos Membros/patologia , Músculo Esquelético/patologia , Distrofias Musculares/patologia
3.
J Cachexia Sarcopenia Muscle ; 13(3): 1850-1863, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35373496

RESUMO

BACKGROUND: Natural history studies in neuromuscular disorders are vital to understand the disease evolution and to find sensitive outcome measures. We performed a longitudinal assessment of quantitative magnetic resonance imaging (MRI) and phosphorus magnetic resonance spectroscopy (31 P MRS) outcome measures and evaluated their relationship with function in lower limb skeletal muscle of dysferlinopathy patients. METHODS: Quantitative MRI/31 P MRS data were obtained at 3 T in two different sites in 54 patients and 12 controls, at baseline, and three annual follow-up visits. Fat fraction (FF), contractile cross-sectional area (cCSA), and muscle water T2 in both global leg and thigh segments and individual muscles and 31 P MRS indices in the anterior leg compartment were assessed. Analysis included comparisons between patients and controls, assessments of annual changes using a linear mixed model, standardized response means (SRM), and correlations between MRI and 31 P MRS markers and functional markers. RESULTS: Posterior muscles in thigh and leg showed the highest FF values. FF at baseline was highly heterogeneous across patients. In ambulant patients, median annual increases in global thigh and leg segment FF values were 4.1% and 3.0%, respectively (P < 0.001). After 3 years, global thigh and leg FF increases were 9.6% and 8.4%, respectively (P < 0.001). SRM values for global thigh FF were over 0.8 for all years. Vastus lateralis muscle showed the highest SRM values across all time points. cCSA decreased significantly after 3 years with median values of 11.0% and 12.8% in global thigh and global leg, respectively (P < 0.001). Water T2 values in ambulant patients were significantly increased, as compared with control values (P < 0.001). The highest water T2 values were found in the anterior part of thigh and leg. Almost all 31 P MRS indices were significantly different in patients as compared with controls (P < 0.006), except for pHw , and remained, similar as to water T2 , abnormal for the whole study duration. Global thigh water T2 at baseline was significantly correlated to the change in FF after 3 years (ρ = 0.52, P < 0.001). There was also a significant relationship between the change in functional score and change in FF after 3 years in ambulant patients (ρ = -0.55, P = 0.010). CONCLUSIONS: This multi-centre study has shown that quantitative MRI/31 P MRS measurements in a heterogeneous group of dysferlinopathy patients can measure significant changes over the course of 3 years. These data can be used as reference values in view of future clinical trials in dysferlinopathy or comparisons with quantitative MRI/S data obtained in other limb-girdle muscular dystrophy subtypes.


Assuntos
Distrofia Muscular do Cíngulo dos Membros , Fósforo , Humanos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Músculo Esquelético/patologia , Distrofia Muscular do Cíngulo dos Membros/diagnóstico por imagem , Distrofia Muscular do Cíngulo dos Membros/patologia , Coxa da Perna , Água
4.
Front Neurol ; 11: 613446, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33391171

RESUMO

Practice of sports during childhood or adolescence correlates with an earlier onset and more rapidly progressing phenotype in dysferlinopathies. To determine if this correlation relates to greater muscle pathology that persists into adulthood, we investigated the effect of exercise on the degree of muscle fatty replacement measured using muscle MRI. We reviewed pelvic, thigh and leg T1W MRI scans from 160 patients with genetically confirmed dysferlinopathy from the Jain Foundation International clinical outcomes study in dysferlinopathy. Two independent assessors used the Lamminen-Mercuri visual scale to score degree of fat replacement in each muscle. Exercise intensity for each individual was defined as no activity, minimal, moderate, or intensive activity by using metabolic equivalents and patient reported frequency of sports undertaken between the ages of 10 and 18. We used ANCOVA and linear modeling to compare the mean Lamminen-Mercuri score for the pelvis, thigh, and leg between exercise groups, controlling for age at assessment and symptom duration. Intensive exercisers showed greater fatty replacement in the muscles of the pelvis than moderate exercisers, but no significant differences of the thigh or leg. Within the pelvis, Psoas was the muscle most strongly associated with this exercise effect. In patients with a short symptom duration of <15 years there was a trend toward greater fatty replacement in the muscles of the thigh. These findings define key muscles involved in the exercise-phenotype effect that has previously been observed only clinically in dysferlinopathy and support recommendations that pre-symptomatic patients should avoid very intensive exercise.

5.
J Neurol Neurosurg Psychiatry ; 89(10): 1071-1081, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29735511

RESUMO

BACKGROUND AND OBJECTIVE: Dysferlinopathies are a group of muscle disorders caused by mutations in the DYSF gene. Previous muscle imaging studies describe a selective pattern of muscle involvement in smaller patient cohorts, but a large imaging study across the entire spectrum of the dysferlinopathies had not been performed and previous imaging findings were not correlated with functional tests. METHODS: We present cross-sectional T1-weighted muscle MRI data from 182 patients with genetically confirmed dysferlinopathies. We have analysed the pattern of muscles involved in the disease using hierarchical analysis and presented it as heatmaps. Results of the MRI scans have been correlated with relevant functional tests for each region of the body analysed. RESULTS: In 181 of the 182 patients scanned, we observed muscle pathology on T1-weighted images, with the gastrocnemius medialis and the soleus being the most commonly affected muscles. A similar pattern of involvement was identified in most patients regardless of their clinical presentation. Increased muscle pathology on MRI correlated positively with disease duration and functional impairment. CONCLUSIONS: The information generated by this study is of high diagnostic value and important for clinical trial development. We have been able to describe a pattern that can be considered as characteristic of dysferlinopathy. We have defined the natural history of the disease from a radiological point of view. These results enabled the identification of the most relevant regions of interest for quantitative MRI in longitudinal studies, such as clinical trials. CLINICAL TRIAL REGISTRATION: NCT01676077.


Assuntos
Músculo Esquelético/diagnóstico por imagem , Distrofia Muscular do Cíngulo dos Membros/diagnóstico por imagem , Adulto , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
6.
Diabetologia ; 60(2): 306-313, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27817155

RESUMO

AIMS/HYPOTHESIS: Women with a history of gestational diabetes mellitus (GDM) have raised liver triacylglycerol. Restriction of energy intake in type 2 diabetes can normalise glucose control and liver triacylglycerol concentration but it is not known whether similar benefits could be achieved in GDM. The aim of this work was to examine liver triacylglycerol accumulation in women with GDM and the effect of modest energy restriction. METHODS: Sixteen women with GDM followed a 4 week diet (5 MJ [1200 kcal]/day). Liver triacylglycerol, before and after diet and postpartum, was measured by magnetic resonance. Insulin secretion and sensitivity were assessed before and after diet. Twenty-six women who underwent standard antenatal care for GDM (matched for age, BMI, parity and ethnicity) were used as a comparator group. RESULTS: Fourteen women, who completed the study, achieved a weight loss of 1.6 ± 1.7 kg over the 4 week dietary period. Mean weight change was -0.4 kg/week in the study group vs +0.3 kg/week in the comparator group (p = 0.002). Liver triacylglycerol level was normal but decreased following diet (3.7% [interquartile range, IQR 1.2-6.1%] vs 1.8% [IQR 0.7-3.1%], p = 0.004). There was no change in insulin sensitivity or production. Insulin was required in six comparator women vs none in the study group (eight vs two required metformin). Blood glucose control was similar for both groups. The hypo-energetic diet was well accepted. CONCLUSIONS/INTERPRETATION: Liver triacylglycerol in women with GDM was not elevated, unlike observations in non-pregnant women with a history of GDM. A 4 week hypo-energetic diet resulted in weight loss, reduced liver triacylglycerol and minimised pharmacotherapy. The underlying pathophysiology of glucose metabolism appeared unchanged.


Assuntos
Diabetes Gestacional/metabolismo , Fígado/metabolismo , Triglicerídeos/metabolismo , Ingestão de Energia/fisiologia , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Gravidez
7.
Neurol Genet ; 2(4): e89, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27602406

RESUMO

OBJECTIVE: To describe the baseline clinical and functional characteristics of an international cohort of 193 patients with dysferlinopathy. METHODS: The Clinical Outcome Study for dysferlinopathy (COS) is an international multicenter study of this disease, evaluating patients with genetically confirmed dysferlinopathy over 3 years. We present a cross-sectional analysis of 193 patients derived from their baseline clinical and functional assessments. RESULTS: There is a high degree of variability in disease onset, pattern of weakness, and rate of progression. No factor, such as mutation class, protein expression, or age at onset, accounted for this variability. Among patients with clinical diagnoses of Miyoshi myopathy or limb-girdle muscular dystrophy, clinical presentation and examination was not strikingly different. Respiratory impairment and cardiac dysfunction were observed in a minority of patients. A substantial delay in diagnosis was previously common but has been steadily reducing, suggesting increasing awareness of dysferlinopathies. CONCLUSIONS: These findings highlight crucial issues to be addressed for both optimizing clinical care and planning therapeutic trials in dysferlinopathy. This ongoing longitudinal study will provide an opportunity to further understand patterns and variability in disease progression and form the basis for trial design.

8.
J Appl Physiol (1985) ; 120(11): 1328-34, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27013608

RESUMO

The purpose of this study was to assess the effects of sucrose vs. glucose ingestion on postexercise liver and muscle glycogen repletion. Fifteen well-trained male cyclists completed two test days. Each test day started with glycogen-depleting exercise, followed by 5 h of recovery, during which subjects ingested 1.5 g·kg(-1)·h(-1) sucrose or glucose. Blood was sampled frequently and (13)C magnetic resonance spectroscopy and imaging were employed 0, 120, and 300 min postexercise to determine liver and muscle glycogen concentrations and liver volume. Results were as follows: Postexercise muscle glycogen concentrations increased significantly from 85 ± 27 (SD) vs. 86 ± 35 mmol/l to 140 ± 23 vs. 136 ± 26 mmol/l following sucrose and glucose ingestion, respectively (no differences between treatments: P = 0.673). Postexercise liver glycogen concentrations increased significantly from 183 ± 47 vs. 167 ± 65 mmol/l to 280 ± 72 vs. 234 ± 81 mmol/l following sucrose and glucose ingestion, respectively (time × treatment, P = 0.051). Liver volume increased significantly over the 300-min period after sucrose ingestion only (time × treatment, P = 0.001). As a result, total liver glycogen content increased during postexercise recovery to a greater extent in the sucrose treatment (from 53.6 ± 16.2 to 86.8 ± 29.0 g) compared with the glucose treatment (49.3 ± 25.5 to 65.7 ± 27.1 g; time × treatment, P < 0.001), equating to a 3.4 g/h (95% confidence interval: 1.6-5.1 g/h) greater repletion rate with sucrose vs. glucose ingestion. In conclusion, sucrose ingestion (1.5 g·kg(-1)·h(-1)) further accelerates postexercise liver, but not muscle glycogen repletion compared with glucose ingestion in trained athletes.


Assuntos
Ingestão de Alimentos/fisiologia , Exercício Físico/fisiologia , Glucose/administração & dosagem , Glicogênio/metabolismo , Fígado/metabolismo , Músculo Esquelético/metabolismo , Sacarose/administração & dosagem , Atletas , Ciclismo/fisiologia , Carboidratos da Dieta/metabolismo , Humanos , Masculino , Resistência Física/fisiologia
9.
Top Magn Reson Imaging ; 24(5): 267-74, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26502308

RESUMO

Magnetic resonance spectroscopy (MRS) provides a noninvasive tool to assess metabolic change in the brain following head injury. Observable metabolites reflect neuronal density and viability, glial density, membrane injury, and hypoxia or ischemia. MRS has been used in traumatic brain injury (TBI) research for nearly 20 years and this article reviews the MRS findings in the adult TBI population.Although MRS observations are heterogeneous, there are consistent patterns in TBI with the neuronal metabolite N-acetyl-aspartate (NAA) significantly reduced in the vast majority of studies, while the membrane related choline signal (Cho) is almost equally found to be elevated. The glial metabolites myo-inositol is often observed to be increased postinjury and this elevation persists into the chronic phase, which is interpreted as revealing gliosis. Observation of elevated lactate levels are sporadic and mainly in acute studies in severely injured subjects. In general, these spectral changes show a dependency on injury severity and acute changes relate to both neuropsychological deficits and to long-term outcome.


Assuntos
Lesões Encefálicas/patologia , Espectroscopia de Ressonância Magnética , Encéfalo/patologia , Humanos
10.
Am J Physiol Endocrinol Metab ; 309(12): E1032-9, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26487008

RESUMO

The purpose of this study was to define the effect of glucose ingestion compared with sucrose ingestion on liver and muscle glycogen depletion during prolonged endurance-type exercise. Fourteen cyclists completed two 3-h bouts of cycling at 50% of peak power output while ingesting either glucose or sucrose at a rate of 1.7 g/min (102 g/h). Four cyclists performed an additional third test for reference in which only water was consumed. We employed (13)C magnetic resonance spectroscopy to determine liver and muscle glycogen concentrations before and after exercise. Expired breath was sampled during exercise to estimate whole body substrate use. After glucose and sucrose ingestion, liver glycogen levels did not show a significant decline after exercise (from 325 ± 168 to 345 ± 205 and 321 ± 177 to 348 ± 170 mmol/l, respectively; P > 0.05), with no differences between treatments. Muscle glycogen concentrations declined (from 101 ± 49 to 60 ± 34 and 114 ± 48 to 67 ± 34 mmol/l, respectively; P < 0.05), with no differences between treatments. Whole body carbohydrate utilization was greater with sucrose (2.03 ± 0.43 g/min) vs. glucose (1.66 ± 0.36 g/min; P < 0.05) ingestion. Both liver (from 454 ± 33 to 283 ± 82 mmol/l; P < 0.05) and muscle (from 111 ± 46 to 67 ± 31 mmol/l; P < 0.01) glycogen concentrations declined during exercise when only water was ingested. Both glucose and sucrose ingestion prevent liver glycogen depletion during prolonged endurance-type exercise. Sucrose ingestion does not preserve liver glycogen concentrations more than glucose ingestion. However, sucrose ingestion does increase whole body carbohydrate utilization compared with glucose ingestion. This trial was registered at https://www.clinicaltrials.gov as NCT02110836.


Assuntos
Ciclismo/fisiologia , Glucose/administração & dosagem , Glicogênio/metabolismo , Fígado/metabolismo , Resistência Física/fisiologia , Sacarose/administração & dosagem , Administração Oral , Adulto , Estudos Cross-Over , Método Duplo-Cego , Exercício Físico/fisiologia , Humanos , Fígado/efeitos dos fármacos , Masculino , Resistência Física/efeitos dos fármacos , Adulto Jovem
11.
J Clin Endocrinol Metab ; 100(4): 1578-85, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25664602

RESUMO

CONTEXT: Although dipeptidyl-peptidase-4 inhibitors exert their major action via an incretin mechanism, a favorable effect of vildagliptin on lipid metabolism remains unexplained. OBJECTIVE: The objective was to examine hepatic triglyceride levels and insulin sensitivity on vildagliptin. DESIGN: This was a 6-month, randomized, double-blind, placebo-controlled trial. SETTING: This was an outpatient study at a university clinical research center. PATIENTS: Individuals with type 2 diabetes (n = 44) and glycated hemoglobin ≤ 7.6% on stable metformin therapy were included. INTERVENTION: Intervention was vildagliptin 50 mg twice a day or placebo over 6 months. MAIN OUTCOME MEASURES: Main outcome measures were hepatic triglyceride levels and insulin sensitivity. RESULTS: Mean fasting liver triglyceride content decreased by 27% with vildagliptin, from 7.3 ± 1.0% (baseline) to 5.3 ± 0.9% (endpoint). There was no change in the placebo group. The between-group difference in change from baseline was significant (P = .013). Mean fasting plasma glucose concentration decreased over the study period with vildagliptin vs placebo by -1.0 mmol/L (P = .018), and there was a positive correlation between these decrements and liver triglyceride in the vildagliptin group at 3 months (r = 0.47; P = .02) and 6 months (r = 0.44; P = .03). Plasma alanine aminotransferase fell from 27.2 ± 2.8 to 20.3 ± 1.4 IU/L in the vildagliptin group (P = .0007), and there was a correlation between the decrements in alanine aminotransferase and liver triglyceride (r = 0.83; P < .0001). Insulin sensitivity during the euglycemic clamp was similar in each group at baseline (3.24 ± 0.30 vs 3.19 ± 0.38 mg/kg/min) and did not change (adjusted mean change of 0.26 ± 0.22 vs 0.32 ± 0.22 mg/kg/min; P = .86). Mean body weight decreased by 1.6 ± 0.5 vs 0.4 ± 0.5 kg in the vildagliptin and placebo groups, respectively (P = .08). CONCLUSIONS: This study demonstrates that the dipeptidyl-peptidase-4 inhibitor vildagliptin brings about a clinically significant decrease in hepatic triglyceride levels during 6 months of therapy unrelated to change in body weight. There was no change in peripheral insulin sensitivity.


Assuntos
Adamantano/análogos & derivados , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Fígado Gorduroso/tratamento farmacológico , Fígado/efeitos dos fármacos , Nitrilas/uso terapêutico , Pirrolidinas/uso terapêutico , Triglicerídeos/metabolismo , Adamantano/administração & dosagem , Adamantano/uso terapêutico , Idoso , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Esquema de Medicação , Fígado Gorduroso/metabolismo , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Fígado/metabolismo , Masculino , Metformina/uso terapêutico , Pessoa de Meia-Idade , Nitrilas/administração & dosagem , Pirrolidinas/administração & dosagem , Vildagliptina
12.
Clin Sci (Lond) ; 128(10): 707-13, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25583442

RESUMO

In health, food carbohydrate is stored as glycogen in muscle and liver, preventing a deleterious rise in osmotically active plasma glucose after eating. Glycogen concentrations increase sequentially after each meal to peak in the evening, and fall to fasting levels thereafter. Skeletal muscle accounts for the larger part of this diurnal buffering capacity with liver also contributing. The effectiveness of this diurnal mechanism has not been previously studied in Type 2 diabetes. We have quantified the changes in muscle and liver glycogen concentration with 13C magnetic resonance spectroscopy at 3.0 T before and after three meals consumed at 4 h intervals. We studied 40 (25 males; 15 females) well-controlled Type 2 diabetes subjects on metformin only (HbA1c (glycated haemoglobin) 6.4±0.07% or 47±0.8 mmol/mol) and 14 (8 males; 6 females) glucose-tolerant controls matched for age, weight and body mass index (BMI). Muscle glycogen concentration increased by 17% after day-long eating in the control group (68.1±4.8 to 79.7±4.2 mmol/l; P=0.006), and this change inversely correlated with homoeostatic model assessment of insulin resistance [HOMA-IR] (r=-0.56; P=0.02). There was no change in muscle glycogen in the Type 2 diabetes group after day-long eating (68.3±2.6 to 67.1±2.0 mmol/mol; P=0.62). Liver glycogen rose similarly in normal control (325.9±25.0 to 388.1±30.3 mmol/l; P=0.005) and Type 2 diabetes groups (296.1±16.0 to 350.5±6.7 mmol/l; P<0.0001). In early Type 2 diabetes, the major physiological mechanism for skeletal muscle postprandial glycogen storage is completely inactive. This is directly related to insulin resistance, although liver glycogen storage is normal.


Assuntos
Ritmo Circadiano/fisiologia , Diabetes Mellitus Tipo 2/metabolismo , Glicogênio/metabolismo , Resistência à Insulina/fisiologia , Fígado/metabolismo , Músculo Esquelético/metabolismo , Período Pós-Prandial/fisiologia , Isótopos de Carbono/metabolismo , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Metformina , Pessoa de Meia-Idade , Concentração Osmolar , Plasma/metabolismo , Estatísticas não Paramétricas , Triglicerídeos/metabolismo
13.
Neurology ; 83(6): 494-501, 2014 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-25031282

RESUMO

OBJECTIVE: To relate neurophysiologic changes after mild/moderate traumatic brain injury to cognitive deficit in a longitudinal diffusion tensor imaging investigation. METHODS: Fifty-three patients were scanned an average of 6 days postinjury (range = 1-14 days). Twenty-three patients were rescanned 1 year later. Thirty-three matched control subjects were recruited. At the time of scanning, participants completed cognitive testing. Tract-Based Spatial Statistics was used to conduct voxel-wise analysis on diffusion changes and to explore regressions between diffusion metrics and cognitive performance. RESULTS: Acutely, increased axial diffusivity drove a fractional anisotropy (FA) increase, while decreased radial diffusivity drove a negative regression between FA and Verbal Letter Fluency across widespread white matter regions, but particularly in the ascending fibers of the corpus callosum. Raised FA is hypothesized to be caused by astrogliosis and compaction of axonal neurofilament, which would also affect cognitive functioning. Chronically, FA was decreased, suggesting myelin sheath disintegration, but still regressed negatively with Verbal Letter Fluency in the anterior forceps. CONCLUSIONS: Acute mild/moderate traumatic brain injury is characterized by increased tissue FA, which represents a clear neurobiological link between cognitive dysfunction and white matter injury after mild/moderate injury.


Assuntos
Lesões Encefálicas/complicações , Lesões Encefálicas/diagnóstico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Fibras Nervosas Mielinizadas/patologia , Adolescente , Adulto , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Hepatology ; 59(6): 2321-30, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24242936

RESUMO

UNLABELLED: Oxidative stress (OS) plays a central role in the progression of liver disease and in damage to liver by toxic xenobiotics. We have developed methods for noninvasive assessment of hepatic OS defenses by measuring flux through the glutathione (GSH) synthesis pathway. (13) C-labeled GSH is endogenously produced and detected by in vivo magnetic resonance after administration of [2-(13) C]-glycine. We report on a successful first-ever human demonstration of this approach as well as preclinical studies demonstrating perturbed GSH metabolism in models of acute and chronic OS. Human studies employed oral administration of [2-(13) C]-glycine and (13) C spectroscopy on a 3T clinical magnetic resonance (MR) imaging scanner and demonstrated detection and quantification of endogenously produced (13) C-GSH after labeled glycine ingestion. Plasma analysis demonstrated that glycine (13) C fractional enrichment achieved steady state during the 6-hour ingestion period. Mean rate of synthesis of hepatic (13) C-labeled GSH was 0.32 ± 0.18 mmole/kg/hour. Preclinical models of acute OS and nonalcoholic steatohepatitis (NASH) comprised CCl4 -treated and high-fat, high-carbohydrate diet-fed Sprague-Dawley rats, respectively, using intravenous administration of [2-(13) C]-glycine and observation of (13) C-label metabolism on a 7T preclinical MR system. Preclinical studies demonstrated a 54% elevation of GSH content and a 31% increase in flux through the GSH synthesis pathway at 12 hours after acute insult caused by CCl4 administration, as well as a 23% decrease in GSH content and evidence of early steatohepatitis in the model of NASH. CONCLUSION: Our data demonstrate in vivo (13) C-labeling and detection of GSH as a biomarker of tissue OS defenses, detecting chronic and acute OS insults. The methods are applicable to clinical research studies of hepatic OS in disease states over time as well as monitoring effects of therapeutic interventions.


Assuntos
Glutationa/biossíntese , Fígado/metabolismo , Estresse Oxidativo , Adulto , Animais , Biomarcadores/metabolismo , Isótopos de Carbono , Glicina , Humanos , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley , Pesquisa Translacional Biomédica
15.
PLoS One ; 8(9): e75048, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24086434

RESUMO

BACKGROUND: Chronic progressive external ophthalmoplegia (CPEO) is a classical mitochondrial ocular disorder characterised by bilateral progressive ptosis and ophthalmoplegia. These ocular features can develop either in isolation or in association with other prominent neurological deficits (CPEO+). Molecularly, CPEO can be classified into two distinct genetic subgroups depending on whether patients harbour single, large-scale mitochondrial DNA (mtDNA) deletions or multiple mtDNA deletions secondary to a nuclear mutation disrupting mtDNA replication or repair. The aim of this magnetic resonance imaging (MRI) study was to investigate whether the ophthalmoplegia in CPEO is primarily myopathic in origin or whether there is evidence of contributory supranuclear pathway dysfunction. METHODS: Ten age-matched normal controls and twenty patients with CPEO were recruited nine patients with single, large-scale mtDNA deletions and eleven patients with multiple mtDNA deletions secondary to mutations in POLG, PEO1, OPA1, and RRM2B. All subjects underwent a standardised brain and orbital MRI protocol, together with proton magnetic resonance spectroscopy in two voxels located within the parietal white matter and the brainstem. RESULTS: There was evidence of significant extraocular muscle atrophy in patients with single or multiple mtDNA deletions compared with controls. There was no significant difference in metabolite concentrations between the patient and control groups in both the parietal white matter and brainstem voxels. Volumetric brain measurements revealed marked cortical and cerebellar atrophy among patients with CPEO+ phenotypes. CONCLUSION: The results of this study support a primary myopathic aetiology for the progressive limitation of eye movements that develops in CPEO.


Assuntos
Sistema Nervoso Central/patologia , Olho/patologia , Atrofia Muscular/patologia , Oftalmoplegia Externa Progressiva Crônica/patologia , Adulto , Idoso , Encéfalo/metabolismo , Encéfalo/patologia , Estudos de Casos e Controles , Compartimento Celular , Estudos de Coortes , DNA Mitocondrial/genética , Feminino , Humanos , Masculino , Metaboloma , Pessoa de Meia-Idade , Oftalmoplegia Externa Progressiva Crônica/genética , Tamanho do Órgão , Deleção de Sequência
16.
Med J Aust ; 199(1): 46-50, 2013 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-23829264

RESUMO

OBJECTIVE: To evaluate the impact of a fruit and vegetable subsidy program on short-term health outcomes of disadvantaged Aboriginal children. DESIGN, SETTING AND PARTICIPANTS: A before-and-after study involving clinical assessments, health record audits and blood testing of all children aged 0-17 2013s (n = 167) from 55 participating families at baseline and after 12 months at three Aboriginal community-controlled health services in New South Wales. All assessments were completed between December 2008 and September 2010. INTERVENTION: A weekly box of subsidised fruit and vegetables linked to preventive health services and nutrition promotion at an Aboriginal Medical Service. MAIN OUTCOME MEASURES: Change in episodes of illness, health service and emergency department attendances, antibiotic prescriptions and anthropometry. RESULTS: There was a significant decrease in oral antibiotics prescribed (- 0.5 prescriptions/2013; 95% CI, - 0.8 to - 0.2) during 12 months of participation in the program compared with the 12 months before the program. The proportion of children classified as overweight or obese at baseline was 28.3% (38/134) and the proportion in each weight category did not change (P = 0.721) after 12 months. A small but significant increase in mean haemoglobin level (3.1 g/L; 95% CI, 1.4-4.8 g/L) was shown, although the proportion with iron deficiency (baseline, 41%; follow-up, 37%; P = 0.440) and anaemia (baseline, 8%; follow-up, 5%; P = 0.453) did not change significantly. CONCLUSION: it and vegetable subsidy program was associated with improvements in some indicators of short-term health status among disadvantaged Aboriginal children. A controlled trial is warranted to investigate the sustainability and feasibility of healthy food subsidy programs in Australia.


Assuntos
Serviços de Saúde da Criança , Assistência Alimentar , Frutas , Serviços de Saúde do Indígena , Havaiano Nativo ou Outro Ilhéu do Pacífico , Verduras , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Nível de Saúde , Humanos , Lactente , Masculino , New South Wales , Avaliação de Programas e Projetos de Saúde , Fatores de Tempo
17.
J R Army Med Corps ; 159(1): 40-43, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23720559

RESUMO

Panic Disorder, with or without agoraphobia, is a common anxiety disorder found in patients presenting in the Primary Care setting, and there is some evidence to suggest that it may not be a rare phenomenon in military populations. This article aims to discuss recognition of the disorder, awareness of its differential diagnoses, and management in Primary Care, particularly if secondary care referrals are not readily available. The National Institute for Clinical Excellence (NICE) Guidelines, both pharmacological and psychological, will be considered. Finally, the impact of Panic Disorder in relation to the Armed Forces in the training and deployed environment will be considered.

18.
J Hepatol ; 59(3): 543-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23624251

RESUMO

BACKGROUND & AIMS: Lysosomal Acid Lipase (LAL) deficiency is a rare metabolic storage disease, caused by a marked reduction in activity of LAL, which leads to accumulation of cholesteryl esters (CE) and triglycerides (TG) in lysosomes in many tissues. We used (1)H magnetic resonance (MR) spectroscopy to characterize the abnormalities in hepatic lipid content and composition in patients with LAL deficiency, and in ex vivo liver tissue from a LAL deficiency rat model. Secondly, we used MR spectroscopy to monitor the effects of an enzyme replacement therapy (ERT), sebelipase alfa (a recombinant human lysosomal acid lipase), on hepatic TG and CE content in the preclinical model. METHODS: Human studies employed cohorts of LAL-deficient patients and NAFLD subjects. Rat experimental groups comprised ex vivo liver samples of wild type, NAFLD, LAL-deficient, and LAL-deficient rats receiving 4weeks of sebelipase alfa treatment. Hepatic (1)H MR spectroscopy was performed using 3T (human) and 7T (preclinical) MRI scanners to quantify hepatic cholesterol and triglyceride content. RESULTS: CE accumulation was identified in LAL deficiency in both human and preclinical studies. A significant decrease in hepatic CE was observed in LAL-deficient rats following treatment with sebelipase alfa. CONCLUSIONS: We demonstrate an entirely non-invasive method to identify and quantify the hepatic lipid signature associated with a rare genetic cause of fatty liver. The approach provides a more favorable alternative to repeated biopsy sampling for diagnosis and disease progression / treatment monitoring of patients with LAL deficiency and other disorders characterised by increased free cholesterol and/or cholesteryl esters.


Assuntos
Ésteres do Colesterol/metabolismo , Fígado/metabolismo , Esterol Esterase/deficiência , Doença de Wolman/metabolismo , Animais , Modelos Animais de Doenças , Ácidos Graxos/metabolismo , Fígado Gorduroso/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Hepatopatia Gordurosa não Alcoólica , Estudos Prospectivos , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Proteínas Recombinantes/uso terapêutico , Esterol Esterase/genética , Esterol Esterase/uso terapêutico , Triglicerídeos/metabolismo , Doença de Wolman/tratamento farmacológico , Doença de Wolman/genética , Doença de Wolman
19.
Br J Nutr ; 110(5): 848-55, 2013 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-23388155

RESUMO

The present study evaluated whether the inclusion of protein (PRO) and amino acids (AA) within a maltodextrin (MD) and galactose (GAL) recovery drink enhanced post-exercise liver and muscle glycogen repletion. A total of seven trained male cyclists completed two trials, separated by 7 d. Each trial involved 2 h of standardised intermittent cycling, followed by 4 h recovery. During recovery, one of two isoenergetic formulations, MD-GAL (0.9 g MD/kg body mass (BM) per h and 0.3 g GAL/kg BM per h) or MD-GAL-PRO+AA (0.5 g MD/kg BM per h, 0.3 g GAL/kg BM per h, 0.4 g whey PRO hydrolysate plus l-leucine and l-phenylalanine/kg BM per h) was ingested at every 30 min. Liver and muscle glycogen were measured after depletion exercise and at the end of recovery using 1H-13C-magnetic resonance spectroscopy. Despite higher postprandial insulin concentations for MD-GAL-PRO+AA compared with MD-GAL (61.3 (se 6.2) v. 29.6 (se 3.0) mU/l, (425.8 (se 43.1) v. 205.6 (se 20.8) pmol/l) P= 0.03), there were no significant differences in post-recovery liver (195.3 (se 2.6) v. 213.8 (se 18.0) mmol/l) or muscle glycogen concentrations (49.7 (se 4.0) v. 51.1 (se 7.9) mmol/l). The rate of muscle glycogen repletion was significantly higher for MD-GAL compared with MD-GAL-PRO+AA (5.8 (se 0.7) v. 3.7 (se 0.6) mmol/l per h, P= 0.04), while there were no significant differences in the rate of liver glycogen repletion (15.0 (se 2.5) v. 13.0 (se 2.7) mmol/l per h). PRO and AA within a MD-GAL recovery drink, compared with an isoenergetic mix of MD-GAL, did not enhance but matched liver and muscle glycogen recovery. This suggests that the increased postprandial insulinaemia only compensated for the lower MD content in the MD-GAL-PRO+AA treatment.


Assuntos
Aminoácidos/farmacologia , Galactose/farmacologia , Fígado/metabolismo , Músculo Esquelético/metabolismo , Polissacarídeos/farmacologia , Proteínas/farmacologia , Adulto , Aminoácidos/administração & dosagem , Bebidas/análise , Ciclismo , Isótopos de Carbono , Método Duplo-Cego , Galactose/administração & dosagem , Glicogênio/metabolismo , Humanos , Fígado/química , Espectroscopia de Ressonância Magnética/métodos , Masculino , Músculo Esquelético/química , Polissacarídeos/administração & dosagem , Proteínas/administração & dosagem
20.
Am J Physiol Endocrinol Metab ; 301(6): E1155-62, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21917633

RESUMO

Mitochondrial dysfunction has been implicated in the pathogenesis of type 2 diabetes. We hypothesized that any impairment in insulin-stimulated muscle ATP production could merely reflect the lower rates of muscle glucose uptake and glycogen synthesis, rather than cause it. If this is correct, muscle ATP turnover rates in type 2 diabetes could be increased if glycogen synthesis rates were normalized by the mass-action effect of hyperglycemia. Isoglycemic- and hyperglycemic-hyperinsulinemic clamps were performed on type 2 diabetic subjects and matched controls, with muscle ATP turnover and glycogen synthesis rates measured using (31)P- and (13)C-magnetic resonance spectroscopy, respectively. In diabetic subjects, hyperglycemia increased muscle glycogen synthesis rates to the level observed in controls at isoglycemia [from 19 ± 9 to 41 ± 12 µmol·l(-1)·min(-1) (P = 0.012) vs. 40 ± 7 µmol·l(-1)·min(-1) in controls]. This was accompanied by a modest increase in muscle ATP turnover rates (7.1 ± 0.5 vs. 8.6 ± 0.7 µmol·l(-1)·min(-1), P = 0.04). In controls, hyperglycemia brought about a 2.5-fold increase in glycogen synthesis rates (100 ± 24 vs. 40 ± 7 µmol·l(-1)·min(-1), P = 0.028) and a 23% increase in ATP turnover rates (8.1 ± 0.9 vs. 10.0 ± 0.9 µmol·l(-1)·min(-1), P = 0.025) from basal state. Muscle ATP turnover rates correlated positively with glycogen synthesis rates (r(s) = 0.46, P = 0.005). Changing the rate of muscle glucose metabolism in type 2 diabetic subjects alters demand for ATP synthesis at rest. In type 2 diabetes, skeletal muscle ATP turnover rates reflect the rate of glucose uptake and glycogen synthesis, rather than any primary mitochondrial defect.


Assuntos
Trifosfato de Adenosina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glicogênio/biossíntese , Músculo Esquelético/metabolismo , Algoritmos , Glicemia/metabolismo , Testes Respiratórios , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/patologia , Metabolismo Energético/fisiologia , Feminino , Técnica Clamp de Glucose , Glicogênio/fisiologia , Humanos , Hiperglicemia/sangue , Hiperglicemia/metabolismo , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Regulação para Cima/fisiologia
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