Arginine Supplementation in MELAS Syndrome: What Do We Know about the Mechanisms?

MELAS syndrome, characterized by mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes, represents a devastating mitochondrial disease, with the stroke-like episodes being its primary manifestation. Arginine supplementation has been used and recommended as a treatment for these acute attacks; however, insufficient evidence exists to support this treatment for MELAS. The mechanisms underlying the effect of arginine on MELAS pathophysiology remain unclear, although it is hypothesized that arginine could increase nitric oxide availability and, consequently, enhance blood supply to the brain. A more comprehensive understanding of these mechanisms is necessary to improve treatment strategies, such as dose and regimen adjustments; identify which patients could benefit the most; and establish potential markers for follow-up. This review aims to analyze the existing evidence concerning the mechanisms through which arginine supplementation impacts MELAS pathophysiology and provide the current scenario and perspectives for future investigations.

Impact of mind-body intervention on proinflammatory cytokines interleukin 6 and 1ß: A three-arm randomized controlled trial for persons with sleep disturbance and depression.

Depressed people are prone to sleep disturbance, which may in return perpetuate the depression. Both depression and sleep disturbance influence proinflammatory cytokines interleukin (IL) 6 and 1ß. Thus interventions for depression should consider the effect on sleep disturbance, and vice versa. Integrative Body-Mind-Spirit (IBMS) and Qigong interventions have been applied in a wide range of health and mental health conditions, including depression and sleep disturbance. This study aimed to evaluate the effect of these two mind-body therapies for persons with both depressive symptoms and sleep disturbance. A three-arm randomized controlled trial was conducted among 281 participants, who were randomly assigned to either IBMS, Qigong or wait list control group. Participants in IBMS and Qigong groups received eight weekly sessions of intervention. Outcome measures were plasma concentrations of IL-6 and IL-1ß, and a questionnaire containing Pittsburgh Sleep Quality Index, Center for Epidemiologic Studies Depression Scale, Somatic Symptom Inventory, Perceived Stress Scale and Body-Mind-Spirit Holistic Well-being Scale. Outcomes were assessed at baseline (T0), immediate post-intervention (T1) and at three-months post-intervention (T2). Besides intervention efficacy analysis, path analysis was performed to explore the relations among perceived stress, depression, sleep disturbance, and IL-6 and IL-1ß values. The study found both IBMS and Qigong reduced depression, sleep disturbance, painful and painless somatic symptoms, IL-6 and IL-1ß levels, and increased holistic well-being. The effect sizes of IBMS and Qigong, mostly in the medium magnitude range, were approximatively equivalent. Path analysis models revealed a predictive role of perceived stress in depression and sleep disturbance, a bidirectional relationship between depression and sleep disturbance, and significant influence of depression and sleep disturbance on IL-6 and IL-1ß. Compared with control, the findings support the efficacy of IBMS and Qigong interventions in relieving depression and sleep disturbance, and in reducing IL-6 and IL-1ß levels.

The Suicide Prevention, Depression Awareness, and Clinical Engagement Program for Faculty and Residents at the University of California, Davis Health.

OBJECTIVE: The objective of the study is to present results of a depression and suicide screening and treatment referral program for physicians at an academic medical center. METHODS: An anonymous web-based screening questionnaire was sent to all physicians at a large academic center. Responses were classified as indicating either high, moderate, or low risk for depression and suicide. Physicians at high and moderate risk were contacted by a counselor through a messaging system. The counselor's message contained information on risk level and an invitation to meet in person. High-risk respondents who did not reply to the message or declined to meet received mental health resources. Respondents who met with the counselor were offered individualized treatment referrals and to participate in a 1-year follow-up of self-reports every 3 months. RESULTS: The questionnaire was sent to approximately 1800 residents, fellows, and faculty from February 2013 through March 2019. A total of 639 questionnaires were received, 100 were excluded for various reasons, and 539 were used to conduct analyses (14.4% response rate). The majority of respondents were classified at moderate (333 [62%]) or high (193 [36%]) risk for depression or suicide. Eighty-three respondents were referred for mental health care, and 14 provided data for the follow-up study. CONCLUSIONS: Results of screening physicians for depression and suicide at one academic medical center highlight the challenges of engaging most of them in this activity and the satisfaction of the minority who successfully engaged in a treatment referral program.

Comparing dyadic cognitive behavioral therapy (CBT) with dyadic integrative body-mind-spirit intervention (I-BMS) for Chinese family caregivers of lung cancer patients: a randomized controlled trial.

PURPOSE: The study adopted a randomized controlled trial to compare the effect of culturally compatible psychosocial interventions on multiple aspects of quality of life (QoL) for family caregivers of lung cancer patients. METHODS: 157 Chinese informal caregivers of lung cancer patients were recruited together with the family members for whom they were providing care, and randomly assigned to either integrative body-mind-spirit intervention (I-BMS) or cognitive behavioral therapy (CBT). Patient-caregiver dyads attended the same arm of intervention in separate groups for 8 weeks. Assessments of generic QoL, anxiety, depression, perceived stress, insomnia, and caregiving burden were measured before intervention (T0), within 1-week (T1), 8-week (T2), and 16-week (T3) post-intervention. RESULTS: Adopting the intention-to-treat analysis, family caregivers in receipt of both I-BMS and CBT exhibited a statistically significant improvement in generic QoL immediately following intervention and at follow-up assessments, with moderate effect size. Improvement of insomnia was found at T1 for both modes, which deteriorated at follow-up; both modes reduced anxiety and perceived stress at follow-up. No intervention effect was observed in depression and domains of caregiving burden. There was no significant interaction effect between intervention type and time. No main or interaction effect between sample background variables and intervention type was found to predict symptomatic changes at T1 and T3. CONCLUSIONS: Culturally attuned I-BMS and CBT exhibited equivalent effectiveness in improving psychological distress and generic QoL for family caregivers of lung cancer patients. To improve the evaluation of outcomes, future study could benefit from incorporating a usual care control.

Comparing the efficacy of integrative body-mind-spirit intervention with cognitive behavioral therapy in patient-caregiver parallel groups for lung cancer patients using a randomized controlled trial.

Purposes/objectives: This paper reports the comparative efficacies of integrative body-mind-spirit intervention (I-BMS) and cognitive behavioral therapy (CBT) in patient-caregiver parallel groups for Chinese patients with lung cancer.Design: Randomized controlled trial (RCT).Methods: One hundred and fifty-seven patient-caregiver dyads with no marked functional impairment were randomized into one of the two interventions with eight weekly patient-caregiver parallel groups. Assessments were conducted at baseline, within one, eight- and sixteen-weeks post-intervention. Effects of treatment group across time were analyzed by multilevel modeling.Findings: CBT led to greater reduction in emotional vulnerability than I-BMS. I-BMS resulted in greater increase in overall QoL and spiritual self-care, and more reduction in depression than CBT. Patients in both interventions experienced improvement in physical, emotional and spiritual, except social, domains of QoL.Conclusion: I-BMS was more efficacious for diverse domains of QoL, and CBT was more effective for emotional well-being, despite the relatively small between-group effect sizes.Implications for psychosocial providers/policy: (1) With the expanding repertoire of psychosocial interventions for families facing lung cancer, it has become imperative to investigate the comparative efficacies of empirically supported and culturally adapted interventions. (2) Our findings show that I-BMS was more effective for diverse domains of QoL, while CBT was more efficacious with emotional well-being, although both interventions led to significant improvements in physical, emotional and spiritual domains of patient QoL. (3) Patient-caregiver parallel groups have been shown to be effective for enhancing QoL of Chinese lung cancer patients. (4) Care professionals are encouraged to dispense interventions based on the idiosyncratic needs and preferences of the patients to maximize the treatment effects.

Stress and psychosomatic symptoms in Chinese adults with sleep complaints: mediation effect of self-compassion.

Although stress has been widely acknowledged to link to psychosomatic dysfunctioning, the underlying mechanism that transmits the impact is not adequately investigated. This study examined self-compassion as a potential mediator that may explain the pathway from stress to depressive and somatic symptoms. Data in the present study were drawn from a baseline survey of 998 Chinese participants who enrolled in an intervention study on sleep disturbance in Hong Kong. Participants completed measures of perceived stress, self-compassion, depressive symptoms, and somatic symptoms. The results showed that stress was associated with depressive symptoms (r = .79, p < .01) and somatic symptoms (r = .47, p < .01). The path analyses showed that low levels of self-compassion mediated the association between stress and psychosomatic symptoms. Our findings provide insight into the pathway how stress affects psychosomatic symptoms. The intervention programs for stress management to improve psychological and physical functioning are recommended to consider self-compassion as a promising component in practice.

Integrative body-mind-spirit intervention for concurrent sleep and mood disturbances: sleep-specific daytime functioning mediates sleep and mood improvements.

Sleep disturbances and depressive symptoms are associated closely with daytime dysfunctions, yet few studies have investigated their temporal relationship in a randomized controlled trial. We investigated the inter-relationships among sleep, depressive symptoms and daytime functioning following an integrative body-mind-spirit (I-BMS) intervention. One hundred and eighty-five participants (mean age 55.28 years, 75.1% female) with co-existing sleep and depressive symptoms were randomized to I-BMS or waiting-list. Daytime functioning variables included the daytime dysfunction items of the Pittsburg Sleep Quality Index (PSQI-day), Somatic Symptom Inventory, Hospital Anxiety Depression Scale and Short Form Health Survey collected at baseline, post-treatment and 3-month follow-up. Sleep and depressive symptoms were measured by the sleep items of the PSQI (PSQI-night) and Center for Epidemiological Studies Depression Scale (excluding the sleep item) (CESD-M). Regression and path analyses were used to understand the role of daytime functioning in sleep and depressive symptoms. We found significant group and time effects on almost all daytime variables and significant group × time interactions on PSQI-day and somatic symptoms. The adjusted regression model showed that CESD-M was associated with all daytime variables. However, PSQI-night was associated only with PSQI-day. Path analyses indicated that PSQI-day bridged PSQI-night and CESD-M in a two-way direction after the I-BMS intervention. The conclusion was that, following I-BMS intervention, improvement in daytime functioning was related predominantly to improvement in depressive symptoms. Night-time sleep related only to daytime dysfunction that was specific to sleep disturbances. Therefore, 'sleep-specific daytime impairment' could be regarded as a major link from night-time sleep to depressive symptoms. More studies are required to understand the concept of 'sleep-specific daytime impairment'.

Identification of compounds from Palicourea rigida leaves with topical anti-inflammatory potential using experimental models.

Palicourea rigida Kunth is traditionally used for the treatment of skin diseases, kidney pains and ovarian inflammation. Based on these traditional uses, this study evaluated the topical anti-inflammatory activity of the ethanol extract from P. rigida leaves (EEPR) and identified bioactive compounds. Ear edema was induced in Swiss mice by the topical application of Croton oil, arachidonic acid, phenol and capsaicin. Histopathological analysis and myeloperoxidase and N-acetyl-ß-D-glucosaminidase activities were determined. EEPR was characterized by UHPLC-UV-MS HPLC and the isolated compound was identified through 1H and 13C nuclear magnetic resonance and mass fragmentation. Interaction profiles between quercetin 3-O-ß-D-glucoside and cyclooxygenase-1 and -2 were established by molecular docking. EEPR significantly inhibited ear edema induced by Croton oil (p < 0.001), arachidonic acid (p < 0.01), phenol (p < 0.001) and capsaicin (p < 0.01 or p < 0.001). Histopathological analysis showed a reduction of edema, inflammatory cell infiltration and vasodilation. Additionally, the myeloperoxidase and N-acetyl-ß-D-glucosaminidase activities were decreased (p < 0.001). From spectroscopic data, quercetin 3-O-ß-D-glucoside was the identified compound. This compound can to interact with cyclooxygenase-1 and -2 through van der Waals interactions and dipole-dipole and hydrogen bonding's, demonstrating inhibition of these enzymes. The results indicate that EEPR is a source of active compounds with topical anti-inflammatory activity, justifying the traditional use of P. rigida and showing that this species has a therapeutic potential to treat skin inflammatory processes.

NO control of mitochondrial function in normal and transformed cells.

Nitric oxide (NO) is a signaling molecule with multiple facets and involved in numerous pathological process, including cancer. Among the different pathways where NO has a functionally relevant participation, is the control of mitochondrial respiration and biogenesis. NO is able to inhibit the electron transport chain, mainly at Complex IV, regulating oxygen consumption and ATP generation, but at the same time, can also induce increase in reactive oxygen and nitrogen species. The presence of reactive species can induce oxidative damage or participate in redox signaling. In this review, we discuss how NO affects mitochondrial respiration and mitochondrial biogenesis, and how it influences the development of mitochondrial deficiency and cancer. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux.

Dyadic associations between psychological distress and sleep disturbance among Chinese patients with cancer and their spouses.

BACKGROUND: Patients with cancer and their spouses usually both suffer, but the dyadic effects have not been thoroughly investigated. This study examined the dyadic effects of psychological distress on sleep disturbance in Chinese couples affected by cancer. METHODS: Patients with cancer and their spouses (N = 135) participated in this study. The Hospital Anxiety and Depression Scale and Pittsburgh Sleep Quality Index were used to measure anxiety, depression, and sleep disturbance. RESULTS: There were significant patient-spouse associations on anxiety (r = 0.48, P < .01), depression (r = 0.55, P < .01), and sleep disturbance (r = 0.30, P < .01). Analyses using the actor-partner interdependence model showed that anxiety had significant actor effects, rather than partner effects, on sleep disturbance in both patients and their spouses, but depression had both actor and partner effects. In addition to providing evidence for the concordance in distress and sleep disturbance in patients with cancer and their spouses, the findings indicate a mutual influence of depression on sleep disturbance among the couples. CONCLUSIONS: Clinicians and health care providers are suggested to integrate depression management as a component of sleep therapies and involve both patients and their spouses in treatment programs.

Fate control and well-being in Chinese rural people living with HIV: mediation effect of resilience.

Fate control has been often misconceptualized as a superstitious belief and overlooked in health psychology. It is not known how this cultural belief might impact the well-being of Chinese people living with HIV. This study examined the protective role of fate control for well-being and the potential mediation effect of resilience. Participants in this study were rural patients who contracted HIV via commercial blood donation. In this cross-sectional survey, 250 participants completed measures of fate control, well-being, and resilience. The results showed that fate control and resilience were positively associated with well-being. Resilience mediated the association between fate control and well-being. Our findings provide insight into the adaptive function of fate control as a cognitive defensive mechanism and highlight the need to incorporate this cultural belief in developing culturally sensitive intervention programs for resilience enhancement tailored for this understudied population infected with HIV living in rural China.

Dimensionality of the Center for Epidemiologic Studies Depression Scale: an exploratory bi-factor analytic study.

OBJECTIVE: The Center for Epidemiologic Studies Depression Scale (CES-D) is a widely used instrument for measuring depressive symptoms. Though conventional factor analytic evaluations supported the use of four sub-scales for the CES-D, existing studies have yet to adopt the bi-factor analytic approach in psychometric assessment of the 20-item inventory. The present study aimed to apply both confirmatory factor analysis and exploratory bi-factor analysis to evaluate the dimensionality of the CES-D. METHODS: Current scoring practice of the CES-D (single-factor, four-factor, and second-order models) was tested using confirmatory factor analyses in a sample of 706 Chinese persons with insomnia and depressive symptoms. As an alternative, exploratory bi-factor analysis was conducted to examine the utility of the general depression factor and specific factors. RESULTS: Existing measurement models on the CES-D did not provide an adequate model fit to the data in terms of model fit indices and discriminant validity. The bi-factor model revealed a general depression factor that accounted for the majority of the item variance. The three specific factors (somatic symptoms, positive affect, and interpersonal problems) provided little unique information over and above the general factor and plausibly represent a methodological artifact rather than a substantive factor. CONCLUSION: The present study demonstrated empirical support for the bi-factor model as a realistic representation of the underlying structure of the CES-D. Researchers and clinicians are better served by simply using a single measure of depression.

Bioactivities of the ethanol extract from Ageratum fastigiatum branches: antioxidant, antinociceptive and anti-inflammatory.

The present study was designed to investigate the antioxidant, antinociceptive and anti-inflammatory activities of the ethanol extract from Ageratum fastigiatum branches. Phytochemical screening and total phenol and flavonoid contents were determined. The antioxidant activity was assessed by 2,2-diphenyl-1-pycrilhydrazin (DPPH) and iron reducing power methods. The antinociceptive effect was evaluated using the acetic acid-induced writhing, formalin, hot plate and tail immersion assays; while the carrageenan-induced paw edema and pleurisy tests were performed to examine the anti-inflammatory activity against acute inflammation. The extract revealed the presence of flavonoids, tannins, coumarins, terpenes, sterols and saponins. Expressive levels of total phenols and flavonoids and a promising antioxidant effect were quantified. At the doses of 50, 100 and 200 mg/kg, the extract inhibited the writhing, reduced both phases of paw licking time and increased the reaction time on the hot plate. In the tail immersion test, the extract (50, 100 and 200 mg/kg) caused a significant inhibition of pain. In these doses, the paw edema, exudate volume and leucocyte mobilization were significantly reduced. These results suggest that A. fastigiatum can be an active source of substances with antioxidant, antinociceptive and anti-inflammatory activities, adding scientific support to the appropriate use in the Brazilian folk medicine.

The Suicide Prevention, Depression Awareness, and Clinical Engagement Program for Faculty and Residents at the University of California, Davis Health System.

OBJECTIVE: The authors replicated a program developed by UC San Diego, identified medical staff at risk for depression and suicide using a confidential online survey, and studied aspects of that program for 1 year. METHODS: The authors used a 35-item, online assessment of stress and depression depression developed and licensed by the American Foundation for Suicide Prevention that aims to identify and suicide risk and facilitate access to mental health services. RESULTS: During 2013/2014, all 1864 UC Davis residents/fellows and faculty physicians received an invitation to take the survey and 158 responded (8% response rate). Most respondents were classified at either moderate (86 [59%]) or high risk for depression or suicide (54 [37%]). Seventeen individuals (11%) were referred for further evaluation or mental health treatment. Ten respondents consented to participate in the follow-up portion of the program. Five of the six who completed follow-up surveys reported symptom improvement and indicated the program should continue. CONCLUSIONS: This program has led to continued funding and a plan to repeat the Wellness Survey annually. Medical staff will be regularly reminded of its existence through educational interventions, as the institutional and professional culture gradually changes to promptly recognize and seek help for physicians' psychological distress.

Choline Acetyltransferase Mutations Causing Congenital Myasthenic Syndrome: Molecular Findings and Genotype-Phenotype Correlations.

Choline acetyltransferase catalyzes the synthesis of acetylcholine at cholinergic nerves. Mutations in human CHAT cause a congenital myasthenic syndrome due to impaired synthesis of ACh; this severe variant of the disease is frequently associated with unexpected episodes of potentially fatal apnea. The severity of this condition varies remarkably, and the molecular factors determining this variability are poorly understood. Furthermore, genotype-phenotype correlations have been difficult to establish in patients with biallelic mutations. We analyzed the protein expression of phosphorylated ChAT of seven CHAT mutations, p.Val136Met, p.Arg207His, p.Arg186Trp, p.Val194Leu, p.Pro211Ala, p.Arg566Cys, and p.Ser694Cys, in HEK-293 cells to phosphorylated ChAT, determined their enzyme kinetics and thermal stability, and examined their structural changes. Three mutations, p.Arg207His, p.Arg186Trp, and p.Arg566Cys, are novel, and p.Val136Met and p.Arg207His are homozygous in three families and associated with severe disease. The characterization of mutants showed a decrease in the overall catalytic efficiency of ChAT; in particular, those located near the active-site tunnel produced the most seriously disruptive phenotypic effects. On the other hand, p.Val136Met, which is located far from both active and substrate-binding sites, produced the most drastic reduction of ChAT expression. Overall, CHAT mutations producing low enzyme expression and severe kinetic effects are associated with the most severe phenotypes.

Managing stress and anxiety through qigong exercise in healthy adults: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: An increasing number of studies have documented the effectiveness of qigong exercise in helping people reduce psychological stress and anxiety, but there is a scarcity of systematic reviews evaluating evidence from randomized controlled trials (RCTs) conducted among healthy subjects. METHODS: Thirteen databases were searched for RCTs from their inception through June 2013. Effects of qigong exercise were pooled across trials. Standardized mean differences (SMDs) were calculated for the pooled effects. Heterogeneity was assessed using the I2 test. The risk of bias was assessed using the Cochrane criteria. RESULTS: Seven RCTs met the inclusion criteria. Two RCTs suggested that qigong exercise immediately relieved anxiety among healthy adults, compared to lecture attendance and structured movements only. Four RCTs suggested qigong exercise relieved anxiety (pooled SMD = -0.75; 95% CI, -1.11 to -0.40), and three RCTs suggested that qigong exercise reduced stress (pooled SMD = -0.88; 95% CI, -1.22 to -0.55) among healthy subjects following one to three months of qigong practice, compared to wait-list controls. CONCLUSIONS: The available evidence suggests that qigong exercise reduces stress and anxiety in healthy adults. However, given the limited number of RCTs and their methodological flaws, further rigorously designed RCTs are needed.

Radioiodine therapy during the COVID-19 pandemic in a public reference hospital in Brazil: an experience report.

COVID-2019 has resulted in an emerging respiratory infection that has spread as a pandemic since January 2020. Nuclear Medicine Services and its workers experienced a dramatic change in their clinical routine. They were required to adjust protocols for this new health condition. Regarding radioiodine therapy (RIT), initial orientations were to postpone treatments. In Brazil, National Nuclear Energy Commission prepared guidelines. It authorized RIT to employ activities over 1850 MBq in an outpatient setting on an exceptional basis. This study reports the RIT experience of a Brazilian hospital during the COVID-19 pandemic, intending to evaluate the applicability of outpatient treatment employing over 1850 MBq of I-131 on a large scale. During referred period, 106 patients at our service had an indication for RIT, of which 58 agreed to participate in the research and provided informed consent. Majority of patients did not meet the minimum requirements for outpatient treatment using doses > 1850 MBq.

The relationships of social support, uncertainty, self-efficacy, and commitment to prenatal psychosocial adaptation.

AIMS: To report a study of the relations of prenatal psychosocial adaptation, social support, demographic and obstetric characteristics, uncertainty, information-seeking behaviour, motherhood normalization, self-efficacy, and commitment to pregnancy. BACKGROUND: Prenatal psychosocial assessment is recommended to identify psychosocial risk factors early to prevent psychiatric morbidities of mothers and children. However, knowledge on psychosocial adaptation and its explanatory variables is inconclusive. DESIGN: This study was non-experimental, with a cross-sectional, correlational, prospective design. METHODS: The study investigated Hong Kong Chinese women during late pregnancy. Convenience sampling methods were used, with 550 women recruited from the low-risk clinics of three public hospitals. Data was collected between January-April 2007. A self-reported questionnaire was used, consisting of a number of measurements derived from an integrated framework of the Life Transition Theory and Theory of Uncertainty in Illness. Explanatory variables of psychosocial adaptation were identified using a structural equation modelling programme. RESULTS: The four explanatory variables of the psychosocial adaptation were social support, uncertainty, self-efficacy, and commitment to pregnancy. In the established model, which had good fit indices, greater psychosocial adaptation was associated with higher social support, higher self-efficacy, higher commitment to pregnancy, and lower uncertainty. CONCLUSION: The findings give clinicians and midwives guidance in the aspects to focus on when providing psychosocial assessment in routine prenatal screening. Since there are insufficient reliable screening tools to assist that assessment, midwives should receive adequate training, and effective screening instruments have to be identified. The explanatory role of uncertainty found in this study should encourage inquiries into the relationship between uncertainty and psychosocial adaptation in pregnancy.

Nitric oxide synthesis is increased in cybrid cells with m.3243A>G mutation.

Nitric oxide (NO) is a free radical and a signaling molecule in several pathways, produced by nitric oxide synthase (NOS) from the conversion of L-arginine to citrulline. Supplementation of L-arginine has been used to treat MELAS (mitochondrial encephalopathy with lactic acidosis and stroke like syndrome), a mitochondrial disease caused by the m.3243A>G mutation. Low levels of serum arginine and endothelium dysfunction have been reported in MELAS and this treatment may increase NO in endothelial cells and promote vasodilation, decreasing cerebral ischemia and strokes. Although clinical benefits have been reported, little is known about NO synthesis in MELAS. In this study we found that osteosarcoma derived cybrid cells with high levels of m.3243A>G had increased nitrite, an NO metabolite, and increased intracellular NO, demonstrated by an NO fluorescent probe (DAF-FM). Muscle vessels from patients with the same mutation had increased staining in NADPH diaphorase, suggestive of increased NOS. These results indicate increased production of NO in cells harboring the m.3243A>G, however no nitrated protein was detected by Western blotting. Further studies are necessary to clarify the exact mechanisms of L-arginine effect to determine the appropriate clinical use of this drug therapy.