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During pregnancy, assessment of cardiac output (𝑄̇), a fundamental measure of cardiovascular function, provides important insight into maternal adaptation. However, methods for dynamic 𝑄̇ measurement require validation. The purpose of this study was to estimate the agreement of 𝑄̇ measured by echocardiography and Modelflow® at rest and during submaximal exercise in non-pregnant (n = 18), pregnant (n = 15, 22-26 weeks gestation) and postpartum women (n = 12, 12-16 weeks post-delivery). Simultaneous measurements of 𝑄̇ derived from echocardiography [criterion] and Modelflow® were obtained at rest and during low-moderate intensity (25% and 50% peak power output) cycling exercise and compared using Bland-Altman analysis and limits of agreement. Agreement between echocardiography and Modelflow® was poor in non-pregnant, pregnant and postpartum women at rest (mean difference ± SD: -1.1 ± 3.4; -1.2 ± 2.9; -1.9 ± 3.2 L.min-1), and this remained evident during exercise. The Modelflow® method is not recommended for 𝑄̇ determination in research involving young, healthy non-pregnant and pregnant women at rest or during dynamic challenge. Previously published 𝑄̇ data from studies utilising this method should be interpreted with caution.

Alzheimer’s disease (AD) is a neurodegenerative disorder, accounting for at least two-thirds of dementia cases. A combination of genetic, epigenetic and environmental triggers is widely accepted to be responsible for the onset and development of AD. Accumulating evidence shows that oxidative stress and dysregulation of energy metabolism play an important role in AD pathogenesis, leading to neuronal dysfunction and death. Redox-induced protein modifications have been reported in the brain of AD patients, indicating excessive oxidative damage. Coenzyme A (CoA) is essential for diverse metabolic pathways, regulation of gene expression and biosynthesis of neurotransmitters. Dysregulation of CoA biosynthesis in animal models and inborn mutations in human genes involved in the CoA biosynthetic pathway have been associated with neurodegeneration. Recent studies have uncovered the antioxidant function of CoA, involving covalent protein modification by this cofactor (CoAlation) in cellular response to oxidative or metabolic stress. Protein CoAlation has been shown to both modulate the activity of modified proteins and protect cysteine residues from irreversible overoxidation. In this study, immunohistochemistry analysis with highly specific anti-CoA monoclonal antibody was used to reveal protein CoAlation across numerous neurodegenerative diseases, which appeared particularly frequent in AD. Furthermore, protein CoAlation consistently co-localized with tau-positive neurofibrillary tangles, underpinning one of the key pathological hallmarks of AD. Double immunihistochemical staining with tau and CoA antibodies in AD brain tissue revealed co-localization of the two immunoreactive signals. Further, recombinant 2N3R and 2N4R tau isoforms were found to be CoAlated in vitro and the site of CoAlation mapped by mass spectrometry to conserved cysteine 322, located in the microtubule binding region. We also report the reversible H2O2-induced dimerization of recombinant 2N3R, which is inhibited by CoAlation. Moreover, CoAlation of transiently expressed 2N4R tau was observed in diamide-treated HEK293/Pank1β cells. Taken together, this study demonstrates for the first time extensive anti-CoA immunoreactivity in AD brain samples, which occurs in structures resembling neurofibrillary tangles and neuropil threads. Covalent modification of recombinant tau at cysteine 322 suggests that CoAlation may play an important role in protecting redox-sensitive tau cysteine from irreversible overoxidation and may modulate its acetyltransferase activity and functional interactions.

Background: Early warning scores (EWS) have been widely used to aid in the detection of deterioration. The use of technology, alongside EWS, may improve patient safety and lead to improvements in the accuracy of documentation. Aim: The aim of this service evaluation was to understand nurses' and healthcare support worker views around the implementation of handheld electronic devices for documenting care related to the deteriorating patient. Methods: Before the implementation of an electronic handheld device, in-depth semi-structured interviews with nursing staff and healthcare support workers were undertaken to explore the context for improvement. The Consolidated Framework for Implementation Research was used to analyse, organise and present data, to ensure systematic inquiry across the range of potential facilitators and challenges perceived by staff. In all, 11 interviews were undertaken across three speciality areas (four wards). Findings: Challenges to the use of new technology included staff apprehension around training and education needs and the uncertainty of technological reliability in the clinical setting. Potential facilitators to support the implementation of this technology were: the potential for improved communication across the individual ward and hospital setting and the potential for more streamlined processes for escalation of concerns. Conclusion: Three main recommendations for practice emerged. First, nurses should be involved in the development of the systems. Appropriate time is required to embed the technology in practice. Finally, thought must be given not just to the absolute number of devices required and their reliability, but also how new technology interacts in each individual context.

Some epidemiological studies with different levels of evidence have pointed to a higher risk of Parkinson’s disease (PD) after exposure to environmental toxicants. A practically unexplored potential etiological factor is a group of naturally-occurring fungal secondary metabolites called mycotoxins. The mycotoxin ochratoxin A (OTA) has been reported to be neurotoxic in mice. To further identify if OTA exposure could have a role in PD pathology, Balb/c mice were orally treated with OTA (0.21, 0.5 mg/kg bw) four weeks and left for six months under normal diet. Effects of OTA on the onset, progression of alpha-synuclein pathology and development of motor deficits were evaluated. Immunohistochemical and biochemical analyses showed that oral subchronic OTA treatment induced loss of striatal dopaminergic innervation and dopaminergic cell dysfunction responsible for motor impairments. Phosphorylated alpha-synuclein levels were increased in gut and brain. LAMP-2A protein was decreased in tissues showing alpha-synuclein pathology. Cell cultures exposed to OTA exhibited decreased LAMP-2A protein, impairment of chaperone-mediated autophagy and decreased alpha-synuclein turnover which was linked to miRNAs deregulation, all reminiscent of PD. These results support the hypothesis that oral exposure to low OTA doses in mice can lead to biochemical and pathological changes reported in PD

Introduction: Previous studies of microtia epidemiology globally have demonstrated significant geographical and ethnic variation, cited broadly as affecting 3–5 in 10,000 live births. The aim of this study was to determine the incidence of microtia in a largely homogeneous ethnic population in the United Kingdom (Wales) and to identify factors, such as distance and socioeconomic status, which may influence the access to surgical intervention.Materials and Methods: A retrospective cohort study was conducted using data linkage to identify patients born between 2000 and 2018 with a diagnosis of microtia. Microtia incidence was calculated using annual and geographic birth rates. Surgical operation codes were used to classify patients into those that had no surgery, autologous reconstruction or prosthetic reconstruction. Sociodemographic attributes were compared using descriptive statistics to determine differences in access to each type of surgical intervention.Results: A total of 101 patients were identified, 64.4% were male and the median age was 12 (8–16). The mean annual incidence was 2.13 microtia cases per 10,000 births over the 19-year study period. Both temporal and geographic variation was noted. The majority of patients undergoing surgery opted for autologous reconstruction (72.9%) at a median age of 9 (7–10) compared to 7 (5–8) for prosthetic reconstruction. Autologous reconstruction had a higher median number of surgeries (2, 1–3) than prosthetic (1.5, 1–2) and a higher median socioeconomic status of 3 (2–4) compared to 2 (1–4) for the prosthetic cohort. There were no statistically significant differences in the distance traveled for surgery.Discussion: This study highlights a role for data linkage in epidemiological analyses and provides a revised incidence of microtia in Wales. Although the majority of patients opted for autologous reconstruction, demographic disparities in socioeconomic status warrant further investigation, emphasizing the importance of striving for equity in accessibility to surgical intervention.

Neuroinflammation is increasingly recognized as an important feature in the pathogenesis of Parkinson's disease (PD). However, it remains unclear whether neuroinflammation contributes to nigral degeneration in PD or is merely a secondary marker of neurodegeneration. We aimed to investigate the temporal relationship between synucleopathy, neuroinflammation and nigrostriatal degeneration in a mouse model of PD. Mice received unilateral intrastriatal injection of alpha-synuclein pre-formed fibrils, alpha-synuclein monomer or vehicle and were sacrificed at 15, 30 and 90 days post-injection. Intrastriatal inoculation of alpha-synuclein fibrils led to significant alpha-synuclein aggregation in the substantia nigra peaking at 30 days after injection while the significant increase in Iba-1 cells, GFAP cells and IL-1β expression peaked earlier at 15 days. At 90 days, the striatal dopaminergic denervation was associated with astroglial activation. Alpha-synuclein monomer did not result in long-term glia activation or increase in inflammatory markers. The spread of alpha-synuclein aggregates into the cortex was not associated with any changes to neuroinflammatory markers. Our results demonstrate that in the substantia nigra glial activation is an early event that precedes alpha-synuclein inclusion formation, suggesting neuroinflammation could play an important early role in the pathogenesis of PD.

KEY POINTS: We sought to determine the isolated and combined influence of hypovolaemia and hypoxic pulmonary vasoconstriction on the decrease in left ventricular (LV) function and maximal exercise capacity observed under hypobaric hypoxia. We performed echocardiography and maximal exercise tests at sea level (344 m), and following 5–10 days at the Barcroft Laboratory (3800 m; White Mountain, California) with and without (i) plasma volume expansion to sea level values and (ii) administration of the pulmonary vasodilatator sildenafil in a double‐blinded and placebo‐controlled trial. The high altitude‐induced reduction in LV filling and ejection was abolished by plasma volume expansion but to a lesser extent by sildenafil administration; however, neither intervention had a positive effect on maximal exercise capacity. Both hypovolaemia and hypoxic pulmonary vasoconstriction play a role in the reduction of LV filling at 3800 m, but the increase in LV filling does not influence exercise capacity at this moderate altitude. ABSTRACT: We aimed to determine the isolated and combined contribution of hypovolaemia and hypoxic pulmonary vasoconstriction in limiting left ventricular (LV) function and exercise capacity under chronic hypoxaemia at high altitude. In a double‐blinded, randomised and placebo‐controlled design, 12 healthy participants underwent echocardiography at rest and during submaximal exercise before completing a maximal test to exhaustion at sea level (SL; 344 m) and after 5–10 days at 3800 m. Plasma volume was normalised to SL values, and hypoxic pulmonary vasoconstriction was reversed by administration of sildenafil (50 mg) to create four unique experimental conditions that were compared with SL values: high altitude (HA), Plasma Volume Expansion (HA‐PVX), Sildenafil (HA‐SIL) and Plasma Volume Expansion with Sildenafil (HA‐PVX‐SIL). High altitude exposure reduced plasma volume by 11% (P

Premature clopidogrel discontinuation is an important cause of stent thrombosis, myocardial infarction, and death after drug-eluting stent (DES) placement. Previous studies of clopidogrel nonadherence after DES placement have had short follow-up and have relied on self-reported adherence. All patients who underwent DES placement from January 2008 to December 2011 at a single safety-net hospital and received medications through the county-subsidized health plan were considered for inclusion; those with1-year follow-up were excluded. We retrospectively collected 1-year refill data from a large, closed pharmacy system. Our primary outcome was time to failure to obtain a clopidogrel refill, allowing a 5-day grace period. Our study cohort (n = 369) was 34% female, 39% Hispanic, 26% white, and 26% African-American; 26% identified Spanish as their primary language. The time to failure to obtain a clopidogrel refill was 153 days. Cumulative failure to obtain at least 1 refill was 23% for the first refill, increasing to 52% at 6 months and 68% at 1 year. Examining the proportion of days covered (PDC), 21% of patients had 100% coverage, whereas 34% had PDC80%. There were no independent predictors of nonadherence (PDC80%). In conclusion, we identified a high rate of clopidogrel nonadherence in a multiethnic urban poor patient population where clopidogrel was provided at discharge and at nominal cost thereafter. In this cohort, prediction models of nonadherence performed poorly. Novel strategies are needed to address this important problem.

The development of new therapies to slow down or halt the progression of Parkinson's disease is a health care priority. A key pathological feature is the presence of alpha-synuclein aggregates, and there is increasing evidence that alpha-synuclein propagation plays a central role in disease progression. Consequently, the downregulation of alpha-synuclein is a potential therapeutic target. As a chronic disease, the ideal treatment will be minimally invasive and effective in the long-term. Knockdown of gene expression has clear potential, and siRNAs specific to alpha-synuclein have been designed; however, the efficacy of siRNA treatment is limited by its short-term efficacy. To combat this, we designed shRNA minicircles (shRNA-MCs), with the potential for prolonged effectiveness, and used RVG-exosomes as the vehicle for specific delivery into the brain. We optimized this system using transgenic mice expressing GFP and demonstrated its ability to downregulate GFP protein expression in the brain for up to 6 weeks. RVG-exosomes were used to deliver anti-alpha-synuclein shRNA-MC therapy to the alpha-synuclein preformed-fibril-induced model of parkinsonism. This therapy decreased alpha-synuclein aggregation, reduced the loss of dopaminergic neurons, and improved the clinical symptoms. Our results confirm the therapeutic potential of shRNA-MCs delivered by RVG-exosomes for long-term treatment of neurodegenerative diseases.

Highlights ► Glucocerebrosidase gene mutations are a risk factor for Parkinson’s disease. ► Glucocerebrosidase inhibition causes mitochondrial dysfunction & oxidative stress. ► These changes parallel important pathogenetic of Parkinson’s disease., Mutations of the gene for glucocerebrosidase 1 (GBA) cause Gaucher disease (GD), an autosomal recessive lysosomal storage disorder. Individuals with homozygous or heterozygous (carrier) mutations of GBA have a significantly increased risk for the development of Parkinson’s disease (PD), with clinical and pathological features that mirror the sporadic disease. The mechanisms whereby GBA mutations induce dopaminergic cell death and Lewy body formation are unknown. There is evidence of mitochondrial dysfunction and oxidative stress in PD and so we have investigated the impact of glucocerebrosidase (GCase) inhibition on these parameters to determine if there may be a relationship of GBA loss-of-function mutations to the known pathogenetic pathways in PD. We have used exposure to a specific inhibitor (conduritol-β-epoxide, CβE) of GCase activity in a human dopaminergic cell line to identify the biochemical abnormalities that follow GCase inhibition. We show that GCase inhibition leads to decreased ADP phosphorylation, reduced mitochondrial membrane potential and increased free radical formation and damage, together with accumulation of alpha-synuclein. Taken together, inhibition of GCase by CβE induces abnormalities in mitochondrial function and oxidative stress in our cell culture model. We suggest that GBA mutations and reduced GCase activity may increase the risk for PD by inducing these same abnormalities in PD brain.

The lysosomal storage disorder Gaucher disease (GD) is caused by autosomal recessive mutations in the glucocerebrosidase (GBA) gene. GBA encodes a lysosomal enzyme (GCase) that catalyses the metabolism of the sphingolipid glucosylceramide to ceramide and glucose. Deficiency of GCase activity results in accumulation of substrate in the lysosomes of several tissues, including brain. Mutations in GBA result in 3 clinical manifestations. Type 1 GD occurs in both children and adults and predominantly impacts on the non-neuronal organs, whereas types 2 and 3 have an onset in childhood and adolescence, respectively, and exhibit neurological deficits.1 Parkinson disease (PD) is primarily characterized by the motor symptoms of resting tremor, bradykinesia, rigidity, and postural instability. Pathological hallmarks include loss of dopaminergic neurons from the substantia nigra (SN) and the presence of cytoplasmic inclusions known as Lewy bodies in the surviving cells of affected brain regions.2 Typical parkinsonism is among the neurological complications of GD (including type 1).3, 4 The neuropathology of GD brains includes the typical hallmarks of PD, such as cortical and brainstem Lewy bodies.5 Heterozygote carriers of GBA mutations also have an increased frequency of PD, and these mutations are the most common genetic risk factor for developing the disease.6–8 Although the pathogenesis of PD is still unknown, the accumulation of α-synuclein and other ubiquitinated proteins in Lewy bodies has implicated protein mishandling as a putative cause. The proteasome and lysosomes are the 2 principal mechanisms for degrading cellular constituents. Autophagy utilizes lysosomes to degrade long-lived proteins, misfolded/aggregated proteins, and organelles such as mitochondria.9 Defective autophagy and/or lysosomal depletion have been implicated in PD.10–13 Cellular or animal models of GCase deficiency have caused α-synuclein accumulation.14–18 GCase has also been suggested to bind directly with α-synuclein in lysosomes19 and the GCase substrate glucosylceramide stabilizes soluble oligomeric α-synuclein species.18 These observations have led to the notion that GCase deficiency might contribute to the α-synuclein aggregation characteristic of PD pathology. Despite the recognized association between GBA mutations and PD, it is unknown how heterozygous GBA mutations affect GCase activity in PD brains. In this paper, we provide the first report of the activity of GCase in several regions of PD brains from GBA mutation carriers and sporadic PD brains. GCase deficiency was greatest in the SN of PD brains with GBA mutations. This loss of activity was in part mediated by a decrease in GCase protein levels. GCase activity was also significantly decreased in the SN of sporadic PD brains.

The purpose of this study was to examine the effects of exercising at different intensities over 7 weeks on components of physical fitness and CVD risk factors. Forty-seven boys and 10 girls, (16.4±0.7 years of age) were divided into a moderate, high intensity, or a control group. All participants had indices of obesity and blood pressure recorded in addition to four physical performance measures pre- and post-intervention. In addition, the intervention groups repeated the physical performance measures at the 4th week phase of the intervention. Following the intervention, significant improvements (P

Background Hepatitis C virus (HCV) infection in Australia is predominantly transmitted through injecting drug use. A reduction in the heroin supply in Australia in late 2000 and early 2001 may have impacted the number of injecting drug users (IDUs) and consequently the number of new hepatitis C infections in Australia. This paper updates estimates of HCV incidence and prevalence between 1960 and 2005. Methods Simple mathematical models were used to estimate HCV incidence among IDUs, migrants to Australia from high HCV-prevalence countries, and other HCV exposure groups. Recent trends in numbers of IDUs were based on indicators of injecting drug use. A natural history of HCV model was applied to estimate the prevalence of HCV in the population. Results The modelled best estimate of past HCV incidence showed a consistent increasing rate of HCV infections to a peak of 14,000 new seroconversions in 1999, followed by a decline in 2001–2002 coincident with the decline in heroin availability. HCV incidence was estimated to be 9700 (lower and upper limits of 6600 and 13,200) in 2005. Of these, 88.7% were estimated to be through injecting drug use, 7.2% among migrants and 4.1% through other transmission routes. An estimated 264,000 (lower and upper limits of 206,000 and 318,000) people were HCV antibody positive in 2005. Conclusions Mathematical models suggest that HCV incidence in Australia decreased from a peak of 14,000 new infections in 1999 to 9700 new infections in 2005, largely attributable to a reduction in injecting drug use. The numbers of people living with HCV in Australia is, however, estimated to continue to increase.

The purpose of this study was to examine relationships between aerobic fitness (AF), fatness, and coronary-heart-disease (CHD) risk factors in 12- to 13-year-olds. The data were obtained from 208 schoolchildren (100 boys; 108 girls) ages 12.9 ± 0.3 years. Measurements included AF, indices of obesity, blood pressure, blood lipids and lipoproteins, fibrinogen, homocysteine, and C-reactive protein. An inverse relationship was found between AF and fatness (p < .05). Fatness was related to a greater number of CHD risk factors than fitness was (p < .05). Further analysis revealed fatness to be an independent predictor of triglyceride and blood-pressure levels (p < .05). Our findings indicate that, for young people, fatness rather than fitness is independently related to CHD risk factors.

Huntington's disease (HD) is caused by an abnormally expanded CAG repeat in the IT-15 gene, which encodes a widely expressed protein called huntingtin. Abnormalities of mitochondrial respiratory chain function, specifically complex II/III, have been identified in HD striatum and defects of energy metabolism have been demonstrated in vivo in skeletal muscle in both symptomatic and presymptomatic HD patients. We have investigated respiratory chain function using histochemical and biochemical methods in HD skeletal muscle from 12 patients and compared these with 12 age and sex-matched controls. The data from the HD patients were related to clinical parameters of HD including the Unified Huntington's Disease Rating Scale (UHDRS). There were positive correlations between CAG repeat years (a product of CAG repeat length and age) and both motor (P < 0.002) and cognitive (P < 0.01) scores of the UHDRS. There was no significant difference in the activities of complexes I to IV compared to age-matched controls. However, there were significant correlations for individual HD complex II/III activities with disease duration (P 0.017), repeat years (P = 0.032), and cognitive scores (P 0.019). There was also evidence from ultrastructural studies that inclusion formation may occur in HD muscle. These results provide additional evidence that mutant huntingtin influences mitochondrial complex II/III function in non-neuronal tissue (skeletal muscle) and suggest that muscle may be a potential marker of disease progression in HD. (C) 2007 Movement Disorder Society.

Friedreich ataxia (FRDA) is a neurodegenerative disorder caused by an unstable GAA repeat expansion mutation within intron 1 of the FXN gene. However, the origins of the GAA repeat expansion, its unstable dynamics within different cells and tissues, and its effects on frataxin expression are not yet completely understood. Therefore, we have chosen to generate representative FRDA mouse models by using the human FXN GAA repeat expansion itself as the genetically modified mutation. We have previously reported the establishment of two lines of human FXN YAC transgenic mice that contain unstable GAA repeat expansions within the appropriate genomic context. We now describe the generation of FRDA mouse models by crossbreeding of both lines of human FXN YAC transgenic mice with heterozygous Fxn knockout mice. The resultant FRDA mice that express only human-derived frataxin show comparatively reduced levels of frataxin mRNA and protein expression, decreased aconitase activity, and oxidative stress, leading to progressive neurodegenerative and cardiac pathological phenotypes. Coordination deficits are present, as measured by accelerating rotarod analysis, together with a progressive decrease in locomotor activity and increase in weight. Large vacuoles are detected within neurons of the dorsal root ganglia (DRG), predominantly within the lumbar regions in 6-month-old mice, but spreading to the cervical regions after 1 year of age. Secondary demyelination of large axons is also detected within the lumbar roots of older mice. Lipofuscin deposition is increased in both DRG neurons and cardiomyocytes, and iron deposition is detected in cardiomyocytes after 1 year of age. These mice represent the first GAA repeat expansion-based FRDA mouse models that exhibit progressive FRDA-like pathology and thus will be of use in testing potential therapeutic strategies, particularly GAA repeat-based strategies.

Hereditary spastic paraplegias (HSPs) are neurodegenerative diseases caused by mutations in more than 20 genes, which lead to progressive spasticity and weakness of the lower limbs. The most frequently mutated gene causing autosomal dominant HSP is SPG4, which encodes spastin, a protein that belongs to the family of ATPases associated with various cellular activities (AAAs). A number of studies have suggested that spastin regulates microtubule dynamics. We have studied the ATPase activity of recombinant human spastin and examined the effect of taxol-stabilized microtubules on this activity. We used spastin translated from the second ATG and provide evidence that this is the physiologically relevant form. We showed that microtubules enhance the ATPase activity of the protein, a property also described for katanin, an AAA of the same spastin subgroup. Furthermore, we demonstrated that human spastin has a microtubule-destabilizing activity and can bundle microtubules in vitro, providing new insights into the molecular pathogenesis of HSP.

This study determined the prevalence of coronary heart disease (CHD) risk factors in young people1of differing socio-economic status (SES). A cohort of 100 boys and 108 girls, aged 12.9, SD 0.3 years drawn of differing SES were assessed for CHD risk factors. Measurements included indices of obesity, blood pressure, aerobic fitness, diet, blood lipids and lipoproteins. Significant differences ( P ≤ 0.05) were detected with respect to SES, for systolic blood pressure, total cholesterol and low density lipopro tein cholesterol, but in boys only. Significant sex differences ( P ≤ 0.05) were identified for systolic blood pressure, diastolic blood pressure, aerobic fitness, waist to hip ratio, summation of four skinfold thicknesses, average daily kilocalorie intake, total choles terol and low density lipoprotein cholesterol. Moreover, increased body fatness, low aerobic fitness, a high fat diet and elevated lipoprotein (a), were the most frequently identified CHD risk factors in this cohort. This study reveals a high incidence of CHD risk factors in young people irrespective of SES and sex, and highlights the need for vigilance in identifying such risk factors from a young age.

The objective of the study was to examine medically managed secondary prevention at one year after coronary artery bypass grafting (CABG). In all, 214 consecutive patients undergoing isolated elective CABG seen four weeks preoperatively and one year post-operatively. Preoperative systolic blood pressure averaged 135±20 mmHg, which increased to 148±25 mmHg (P

Animal studies indicate that insulin resistance and glucose intolerance leading to dyslipidemia in uremic rats are associated with increased cytosolic calcium ([Ca++ i]). The resistance and intolerance are reversed with verapamil, but recur after its discontinuation. This finding suggests that hyperparathyroid-induced [Ca ++ i] increase is responsible for the metabolic derangement. We retrospectively examined, over a 12-year period, the effects of factors that lower [Ca ++ i] on total serum cholesterol and triglycerides in 332 hemodialysis (HD) patients. Because the study was retrospective, detailed lipid profiles were not available. We therefore relied on morbidity and mortality outcomes related to atherosclerotic vascular disease. Patients with diabetes mellitus were excluded, because their dyslipidemia and vascular disease are mediated via a different mechanism. Four groups emerged: group I [high parathormone (PTH) in the absence of calcium channel blockers (CCBs), n = 107], representing the highest [Ca++ i]; group II (high PTH in the presence of CCBs, n = 76) and group III (lower PTH in the absence of CCBs, n = 66), representing intermediate [Ca ++ i]; and group IV (lower PTH in the presence of CCBs, n = 83) representing the lowest [Ca ++ i]. The theoretically lower [Ca ++ i] was achieved via CCB therapy or lower PTH, or both. The mean serum cholesterol in group I was 322 ± 24 mg/dL and the level of triglycerides was 398 ± 34 mg/dL. Group II had mean serum cholesterol of 196 ± 16 mg/dL and triglycerides of 157 ± 17 mg/dL. Group III had a mean serum cholesterol of 202 ± 19 mg/dL and triglycerides of 160 ± 15 mg/dL. Group IV had a mean serum cholesterol of 183 ± 9 mg/dL and triglycerides of 94 ± 6 mg/dL. The differences in cholesterol and triglyceride levels among four groups were significant (p < 0.001) by one-way analysis of variance (ANOVA). The incidence of cardiovascular morbidity and mortality events was 61% in group I, 24% in group II, 28% in group III, and 18% in group IV (χ 2 = 47.7, p < 0.001). We conclude that, in non diabetic HD patients, hyperparathyroidism, especially in the absence of CCBs, is associated with severe dyslipidemia and increased risk of cardiovascular morbidity and mortality. Dyslipidemia may be related to a hyperparathyroid-induced increase in cytosolic calcium [Ca++ i]. Lowering [Ca++ i] by decreasing PTH or by blocking calcium entry into cells (via CCBs), or both, is associated with less dyslipidemia and improved long-term cardiovascular morbidity and mortality. Prospective randomized studies, with actual measurement of [Ca ++ i], are needed to verify the results of this study.

Friedreich's ataxia (FA) is the most common form of autosomal recessive spinocerebellar ataxia and is often associated with a cardiomyopathy. The disease is caused by an expanded intronic GAA repeat, which results in deficiency of a mitochondrial protein called frataxin. In the yeast YFH1 knockout model of the disease there is evidence that frataxin deficiency leads to a severe defect of mitochondrial respiration, intramitochondrial iron accumulation, and associated production of oxygen free radicals. Recently, the analysis of FA cardiac and skeletal muscle samples and in vivo phosphorus magnetic resonance spectroscopy (31P-MRS) has confirmed the deficits of respiratory chain complexes in these tissues. The role of oxidative stress in FA is further supported by the accumulation of iron and decreased aconitase activities in cardiac muscle. We used 31P-MRS to evaluate the effect of 6 months of antioxidant treatment (Coenzyme Q10 400 mg/day, vitamin E 2,100 IU/day) on cardiac and calf muscle energy metabolism in 10 FA patients. After only 3 months of treatment, the cardiac phosphocreatine to ATP ratio showed a mean relative increase to 178% (p = 0.03) and the maximum rate of skeletal muscle mitochondrial ATP production increased to 139% (p = 0.01) of their respective baseline values in the FA patients. These improvements, greater in prehypertrophic hearts and in the muscle of patients with longer GAA repeats, were sustained after 6 months of therapy. The neurological and echocardiographic evaluations did not show any consistent benefits of the therapy after 6 months. This study demonstrates partial reversal of a surrogate biochemical marker in FA with antioxidant therapy and supports the evaluation of such therapy as a disease-modifying strategy in this neurodegenerative disorder.

To clarify the role of neuronal complex I activity in idiopathic Parkinson's disease (IPD), expression of mitochondrial mRNA encoding the ND1 subunit of mitochondrial complex I was examined by semiquantitative in situ hybridization histochemistry in melanized neurons of human substantia nigra in IPD cases and control subjects. Expression of mRNA encoding the glycolytic enzyme, aldolase C, was also examined in substantia nigra and other neurons of the midbrain and brain stem. ND1 mRNA expression was strong in melanized substantia nigra neurons but undetectable in nigral glia. Levels of expression in nigral neurons were higher than in neurons of the red nucleus or cranial nerve nuclei, but similar values were obtained in pontine neurons. ND1 mRNA expression was reduced by about 25% in melanized neurons in IPD. There was no relationship between ND1 expression per cell and disease duration or L-DOPA dosage in the IPD group. No change in ND1 expression was observed in pontine neurons in IPD, and ND1 expression in the locus ceruleus was also unchanged. Melanized nigral neurons expressed lower levels of aldolase C mRNA than other midbrain or brain stem populations in both control and IPD material. These findings suggest that dopamine neurons are more strongly dependent on mitochondrial energy metabolism and oxidative phosphorylation than other brain stem populations. Because mitochondrial complex I activity is significantly reduced in IPD, intrinsically low expression of glycolytic enzymes, together with disease-related reduction in complex I activity, may be a contributory factor predisposing nigral neurons to injury.

Mitochondrial DNA depletion syndrome is an autosomal inherited disease associated with grossly reduced cellular levels of mitochondrial DNA in infancy. Most patients are born after a full and uncomplicated pregnancy, are normal at birth, but develop symptoms in the early neonatal period. These observations have led to the suggestion that the patients have a defect affecting the control of mitochondrial DNA copy number after birth. Using immunocytochemical techniques, we demonstrated that the disease is already expressed in amniotic fluid cells. Detection of mitochondrial DNA depletion in these fetal cells indicates that the defect may already be expressed early in embryological development.

Purpose. This study investigates cardiovascular disease risk factor response in adolescents following introduction of brisk walking into curriculum lessons. Design. Quasi-experimental. Setting. School-based. Subjects. An intervention group consisted of 115 (aged 12.4 ± 0.5 y) year eight participants, and 77 (aged 12.1 ± 1.1 y) year seven and year nine participants formed a control. Intervention. An 18-week cross-curricular physical activity intervention was implemented in one secondary school. Measures. Adiposity variables, blood pressure, lipids, lipoproteins, glucose, insulin, high-sensitivity C-reactive protein, high-molecular-weight adiponectin, aerobic fitness, physical activity behavior, and diet were assessed preintervention and postintervention. Analysis. Dependent and independent t-tests. Results. Prevalence of elevated waist circumference (9.8% vs. 6.9%), systolic blood pressure (3.3% vs. 0%), triglycerides (2.5% vs. 1.2%), and reduced high density lipoprotein cholesterol (3.7% vs. 2.7%) decreased in the intervention group. Significant improvements in high density lipoprotein cholesterol to total cholesterol ratio (mean ± SD: 2% ± 4% [confidence interval (CI)0.05 = 1% to 2%], t80 = −3.5, p = .001) and glucose (−.1 ± .4 mmol/L [CI0.05 = −.2% to 0%], t79 = 3.2, p = .002) were evident for the intervention group. Conclusion. The Activity Knowledge Circuit may prove to be a sustainable, effective, and cost-effective strategy to engage schoolchildren in physical activity on a daily basis. A longer-duration intervention is required to fully understand risk factor response in adolescents.

This study examined the effects of high intensity exercise on physical fitness components and cardiovascular disease (CVD) risk factors in youth. Forty-one participants (15-17 years) were divided into a control and an intervention (high intensity exercise, HIT) group. The HIT group (15 boys, 2 girls) performed three weekly sessions over seven weeks consisting of either four to six repeats of maximal sprint running with 20-30 s recovery. The control group (20 boys, 4 girls) continued their normal activity patterns. All participants had indices of obesity and blood pressure (BP) recorded in addition to four physical performance measures pre-and post-intervention: cardiorespiratory fitness, muscular power, sprint speed and agility. In the HIT group, significant improvements in cardiorespiratory fitness (P

Objective: Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused in almost all cases by homozygosity for a GAA trinucleotide repeat expansion in the frataxin gene. Frataxin is a mitochondrial protein involved in iron homeostasis. FRDA patients have a high prevalence of diabetes, the pathogenesis of which is not known. We aimed to evaluate the relative contribution of insulin resistance and β-cell failure and the pathogenic mechanisms involved in FRDA diabetes. Methods: Forty-one FRDA patients, 26 heterozygous carriers of a GAA expansion, and 53 controls underwent oral and intravenous glucose tolerance tests. β-Cell proportion was quantified in postmortem pancreas sections from 9 unrelated FRDA patients. Using an in vitro disease model, we studied how frataxin deficiency affects β-cell function and survival. Results: FRDA patients had increased abdominal fat and were insulin resistant. This was not compensated for by increased insulin secretion, resulting in a markedly reduced disposition index, indicative of pancreatic β-cell failure. Loss of glucose tolerance was driven by β-cell dysfunction, which correlated with abdominal fatness. In postmortem pancreas sections, pancreatic islets of FRDA patients had a lower β-cell content. RNA interference–mediated frataxin knockdown impaired glucose-stimulated insulin secretion and induced apoptosis in rat β cells and human islets. Frataxin deficiency sensitized β cells to oleate-induced and endoplasmic reticulum stress-induced apoptosis, which could be prevented by the incretins glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. Interpretation: Pancreatic β-cell dysfunction is central to diabetes development in FRDA as a result of mitochondrial dysfunction and higher sensitivity to metabolic and endoplasmic reticulum stress-induced β-cell death. ANN NEUROL 2012;72:971–982

Objective: To investigate chaperone-mediated autophagy in the pathogenesis of Parkinson disease (PD).Design: Postmortem observational study.Setting: University Department of Clinical Neuroscience, Institute of Neurology, University College London.Subjects: Postmortem samples from 7 PD, 6 Alzheimer disease (AD), and 8 control brains.Main Outcome Measure: Lysosomal-associated membrane protein 2A (LAMP2A) and heat shock cognate 70 (hsc70) protein levels were compared in the substantia nigra pars compacta and amygdala of PD, AD, and control brain samples. To provide insight into the turnover of alpha-synuclein, degradation pathways for this protein were studied in a dopaminergic cell line.Results: The expression levels of the chaperone-mediated autophagy proteins LAMP2A and hsc70 were significantly reduced in the substantia nigra pars compacta and amygdala of PD brains compared with age-matched AD and control brain samples. Lewy bodies in these regions contained autophagy-related proteins. We demonstrated that decreased LAMP2A levels in dopaminergic cell lines reduced chaperone-mediated autophagy activity and increased the half-life of alpha-synuclein.Conclusions: These findings suggest that there is reduced chaperone-mediated autophagy activity in the PD brain, provide evidence for the role of autophagy in PD pathogenesis and Lewy body formation, and suggest that this pathway may be a suitable therapeutic target in PD.

Both genetic and environmental factors are thought to be involved in the aetiology of Parkinson's disease (PD). Oxidative damage, mitochondrial and proteasomal dysfunction, and inflammatory change are considered to participate in PD pathogenesis. Dopamine agonists are used in the symptomatic treatment of PD but attention has recently also been focussed on their potential for use in slowing disease progression. We have studied the protective actions of the D2 dopamine agonist cabergoline in toxin (paraquat) and genetic (wild-type and mutant [A53T] alpha-synuclein) models of PD using SHSY-5Y cells. Cabergoline increased glutathione content, reduced free radical production and caspase-3 activation, increased mitochondrial membrane potential and ameliorated cell death in SHSY-5Y cells exposed to paraquat and this action was inhibited in part by D2 receptor blockade. Cabergoline also reduced the toxicity of wild-type and mutant alpha-synuclein expression following paraquat exposure by similar mechanisms. These results confirm the protective action of cabergoline in reducing cell death in two separate genetic and environmental model systems of PD.

MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) is commonly associated with the A3243G mitochondrial DNA (mtDNA) mutation encoding the transfer RNA of leucine (UUR) (tRNA (Le(UUR))). The pathogenetic mechanisms of this mutation are not completely understood. Neuronal functions are particularly vulnerable to alterations in oxidative phosphorylation, which may affect the function of the neurotransmitter glutamate, leading to excitotoxicity. In order to investigate the possible effects of A3243G upon glutamate homeostasis, we assessed glutamate uptake in osteosarcoma-derived cytoplasmic hybrids (cybrids) expressing high levels of this mutation. High-affinity Na+-dependent glutamate uptake was assessed as radioactive [H-3]-glutamate influx mediated by specific excitatory amino acid transporters (EAATs). The maximal rate (V-max) of Na+-dependent glutamate uptake was significantly reduced in all the mutant clones. Although the defect did not relate to either the mutant load or magnitude of oxidative phosphorylation defect, we found an inverse relationship between A3243G mutation load and mitochondrial ATP synthesis, without any evidence of increased cellular or mitochondrial free radical production in these A3243G clones. These data suggest that a defect of glutamate transport in MELAS neurons may be due to decreased energy production and might be involved in mediating the pathogenic effects of the A3243G mtDNA mutation. (C) 2008 Elsevier Inc. All rights reserved.

Background: Decreased mitochondrial respiratory chain function and increased oxidative stress have been implicated in the pathogenesis of Friedreich ataxia (FRDA), raising the possibility that energy enhancement and antioxidant therapies may be an effective treatment.Objective: To evaluate the long-term efficacy of a combined antioxidant and mitochondrial enhancement therapy on the bioenergetics and clinical course of FRDA.Design: Open-labeled pilot trial over 47 months.Patients: Seventy-seven patients with clinical and genetically defined FRDA.Intervention: A combined coenzyme Q(10) (400 mg/d) and vitamin E (2100 IU/d) therapy of 10 patients with FRDA over 47 months.Main Outcome Measures: Clinical assessment using echocardiography and the International Cooperative Ataxia Rating Scale and cardiac and skeletal muscle bioenergetics, as assessed using phosphorus P 31 magnetic resonance spectroscopy.Results: There was a significant improvement in cardiac and skeletal muscle bioenergetics that was maintained throughout the 47 months of therapy. Echocardiographic data revealed significantly increased fractional shortening at the 35- and 47-month time points. Comparison with cross-sectional data from 77 patients with FRDA indicated the changes in total International Cooperative Ataxia Rating Scale and kinetic scores over the trial period were better than predicted for 7 patients, but the posture and gait and hand dexterity scores progressed as predicted.Conclusion: This therapy resulted in sustained improvement in mitochondrial energy synthesis that was associated with a slowing of the progression of certain clinical features and a significant improvement in cardiac function.

Background Dickkopf related protein 1 (DKK1) has been proposed as the master regulator of joint remodelling. This Wnt signalling pathway inhibitor is involved in osteoblast growth and differentiation. In rheumatoid arthritis, increased DKK1 plasma levels correlate with inflammation and bone erosions. Furthermore, patients with rheumatoid arthritis who carry genetic variants in the DKK1 gene have higher serum DKK1 levels and more progressive joint destruction, suggesting a fundamental role for DKK1 in rheumatoid arthritis. In the diseased joint, synovial fibroblasts are key mediators of bone and cartilage destruction via secretion of matrix metalloproteinases and regulation of monocyte to osteoclast differentiation. In this study we analysed whether DKK1 secretion might contribute to this effect. We hypothesised that synovial fibroblasts from patients with early rheumatoid arthritis would be characterised by high DKK1 expression compared with those from patients with resolving arthritis. Methods Synovial tissue samples were obtained by ultrasound-guided biopsy from patients with early synovitis within 12 weeks of symptom onset. 12 patients developed rheumatoid arthritis (according to 1987 American College of Rheumatology criteria) and eight had self-limiting disease within 18 months' follow-up. Synovial fibroblasts were cultured and expanded to passage three with established methods. mRNA expression was quantified with real-time quantitative PCR. DKK1 levels were measured in the supernatants of cultured cells with a commercial ELISA kit (RD p=0·07). Expression levels of DKK1 mRNA or protein did not correlate with disease duration, or with clinical indices. Analysis of DKK1 promoter methylation showed a trend towards promoter hypomethylation in samples from early rheumatoid arthritis compared with resolving samples (1·04-fold enrichment vs 1·52-fold enrichment, not significant). Further samples are being analysed to increase the power of the study. Interpretation DKK1 is an inhibitor of the Wnt signalling pathway that promotes cell invasion and a pro-destruction imbalance of osteoblast and osteoclast activity. Our data suggest that expression of DKK1 by fibroblasts cultured from treatment-naive patients discriminates between persistent and resolving disease, and occurs early in the disease process in rheumatoid arthritis. This difference in gene expression might be under epigenetic control at the level of DNA methylation. Current studies are focusing on validating these findings. Funding Wellcome Trust.

A 5 kilobase deletion in mitochondrial DNA (mtDNA) has been reported to be responsible for the specific complex I deficiency in the substantia nigra (SN) of the Parkinson's disease (PD) brain. We have studied mitochondrial respiratory chain function in the SN from control and PD subjects, and analysed mtDNA, extracted from the same tissues, by Southern biot and the polymerase chain reaction (PCR). Quantitation of the levels of the deletion indicate that it does not contribute to the pathogenesis of PD nor to a complex I deficiency but seems likely to be an age-related observation.

Summary We report the first missense mutation in the mtDNA gene for subunit II of cytochrome c oxidase (COX). The mutation was identified in a 14-year-old boy with a proximal myopathy and lactic acidosis. Muscle histochemistry and mitochondrial respiratory-chain enzymology demonstrated a marked reduction in COX activity. Immunohistochemistry and immunoblot analyses with COX subunit–specific monoclonal antibodies showed a pattern suggestive of a primary mtDNA defect, most likely involving CO II, for COX subunit II (COX II). mtDNA-sequence analysis demonstrated a novel heteroplasmic T→A transversion at nucleotide position 7,671 in CO II. This mutation changes a methionine to a lysine residue in the middle of the first N-terminal membrane-spanning region of COX II. The immunoblot studies demonstrated a severe reduction in cross-reactivity, not only for COX II but also for the mtDNA-encoded subunit COX III and for nuclear-encoded subunits Vb, VIa, VIb, and VIc. Steady-state levels of the mtDNA-encoded subunit COX I showed a mild reduction, but spectrophotometric analysis revealed a dramatic decrease in COX I–associated heme a3 levels. These observations suggest that, in the COX protein, a structural association of COX II with COX I is necessary to stabilize the binding of heme a3 to COX I.