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1.
Mol Biol Rep ; 47(7): 5587-5620, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32564227

RESUMO

Nitro-oxidative stress and lowered antioxidant defences play a key role in neuropsychiatric disorders such as major depression, bipolar disorder and schizophrenia. The first part of this paper details mitochondrial antioxidant mechanisms and their importance in reactive oxygen species (ROS) detoxification, including details of NO networks, the roles of H2O2 and the thioredoxin/peroxiredoxin system, and the relationship between mitochondrial respiration and NADPH production. The second part highlights and identifies the causes of the multiple pathological sequelae arising from self-amplifying increases in mitochondrial ROS production and bioenergetic failure. Particular attention is paid to NAD+ depletion as a core cause of pathology; detrimental effects of raised ROS and reactive nitrogen species on ATP and NADPH generation; detrimental effects of oxidative and nitrosative stress on the glutathione and thioredoxin systems; and the NAD+-induced signalling cascade, including the roles of SIRT1, SIRT3, PGC-1α, the FOXO family of transcription factors, Nrf1 and Nrf2. The third part discusses proposed therapeutic interventions aimed at mitigating such pathology, including the use of the NAD+ precursors nicotinamide mononucleotide and nicotinamide riboside, both of which rapidly elevate levels of NAD+ in the brain and periphery following oral administration; coenzyme Q10 which, when given with the aim of improving mitochondrial function and reducing nitro-oxidative stress in the brain, may be administered via the use of mitoquinone, which is in essence ubiquinone with an attached triphenylphosphonium cation; and N-acetylcysteine, which is associated with improved mitochondrial function in the brain and produces significant decreases in oxidative and nitrosative stress in a dose-dependent manner.


Assuntos
Metabolismo Energético/fisiologia , Transtornos Mentais/fisiopatologia , Estresse Oxidativo/fisiologia , Antioxidantes/metabolismo , Glutationa/metabolismo , Humanos , Mitocôndrias/metabolismo , Doenças do Sistema Nervoso/psicologia , Niacinamida/farmacologia , Oxirredução , Estresse Oxidativo/genética , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxinas/metabolismo , Ubiquinona/análogos & derivados , Ubiquinona/farmacologia
2.
J Intellect Disabil Res ; 56(9): 895-901, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21883600

RESUMO

BACKGROUND: Previous studies in adults with intellectual disabilities (ID) have reported a higher prevalence of obesity than in the general population, and a trend to an increase in the prevalence of excess weight. However, little information is available on body weight status and lipids levels of adults with ID and co-existing mental illness. The aim of this study was to address this information gap, by conducting a stepwise multiple regression analysis to predict BMI, thereby allowing the investigation of (semi-)partial correlations, which assess the extent to which a particular predictor variable is associated with BMI over and above the other predictors. METHODS: A study of the patients with ID and psychiatric illness registered in the service. Collected data included body mass index (BMI), age, gender, the presence of additional physical conditions, residential status, mental illness and use the psychotropic medication. We analysed the lipid profile including serum cholesterol together with low-density lipoprotein, high-density lipoprotein (HDL), triglycerides and the serum cholesterol/HDL ratio. Data for these variables were entered into a stepwise multiple linear regression to predict BMI. RESULTS: 28% of the participants were overweight and 41% obese. Most of the obese patients were men with mild ID (P = 0.039). Level of ID (P = 0.003), gender (P = 0.001) and serum triglycerides (P = 0.026) had significant predictive value in the regression model. There were no significant differences in either the mean serum cholesterol levels or the mean triglyceride levels between those taking and those not taking first-generation antipsychotics, second-generation antipsychotics or anti-epileptic medication. CONCLUSIONS: The rate of obesity in our sample was higher than in previous studies. The most predictive combination of predictors to predict BMI was ID level, gender and serum triglyceride levels. Serum triglyceride and cholesterol levels did not appear to be unduly affected by first- or second-generation antipsychotic medication or by antiepileptic medication.


Assuntos
Deficiência Intelectual/metabolismo , Lipídeos/sangue , Transtornos Mentais/metabolismo , Obesidade/metabolismo , Sobrepeso/metabolismo , Adolescente , Adulto , Idoso , Anticonvulsivantes/uso terapêutico , Antipsicóticos/uso terapêutico , Índice de Massa Corporal , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Humanos , Deficiência Intelectual/tratamento farmacológico , Deficiência Intelectual/epidemiologia , Masculino , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Valor Preditivo dos Testes , Prevalência , Triglicerídeos/sangue , Adulto Jovem
3.
Mol Neurobiol ; 58(5): 2158-2182, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33411248

RESUMO

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor encoded by NFE2L2. Under oxidative stress, Nrf2 does not undergo its normal cytoplasmic degradation but instead travels to the nucleus, where it binds to a DNA promoter and initiates transcription of anti-oxidative genes. Nrf2 upregulation is associated with increased cellular levels of glutathione disulfide, glutathione peroxidase, glutathione transferases, thioredoxin and thioredoxin reductase. Given its key role in governing the cellular antioxidant response, upregulation of Nrf2 has been suggested as a common therapeutic target in neuropsychiatric illnesses such as major depressive disorder, bipolar disorder and schizophrenia, which are associated with chronic oxidative and nitrosative stress, characterised by elevated levels of reactive oxygen species, nitric oxide and peroxynitrite. These processes lead to extensive lipid peroxidation, protein oxidation and carbonylation, and oxidative damage to nuclear and mitochondrial DNA. Intake of N-acetylcysteine, coenzyme Q10 and melatonin is accompanied by increased Nrf2 activity. N-acetylcysteine intake is associated with improved cerebral mitochondrial function, decreased central oxidative and nitrosative stress, reduced neuroinflammation, alleviation of endoplasmic reticular stress and suppression of the unfolded protein response. Coenzyme Q10, which acts as a superoxide scavenger in neuroglial mitochondria, instigates mitohormesis, ameliorates lipid peroxidation in the inner mitochondrial membrane, activates uncoupling proteins, promotes mitochondrial biogenesis and has positive effects on the plasma membrane redox system. Melatonin, which scavenges mitochondrial free radicals, inhibits mitochondrial nitric oxide synthase, restores mitochondrial calcium homeostasis, deacetylates and activates mitochondrial SIRT3, ameliorates increased permeability of the blood-brain barrier and intestine and counters neuroinflammation and glutamate excitotoxicity.


Assuntos
Encéfalo/metabolismo , Transtornos Mentais/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Humanos , Transtornos Mentais/metabolismo , Mitocôndrias/metabolismo , Neuropsiquiatria
4.
J Int Med Res ; 38(4): 1468-72, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20926020

RESUMO

This study aimed to test the hypothesis that structural grey matter brain changes might occur in the chronic intractable pain disorder fibromyalgia when this is associated with marked fatigue in the absence of a DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision) diagnosis of affective disorder. High-resolution 3-T cerebral magnetic resonance imaging scans were acquired in 10 female, right-handed, non-smoking, white Caucasian subjects: five patients with fibromyalgia associated with marked fatigue and five age-matched healthy women. Voxel-wise generalized linear modelling of the processed neuroanatomical data using permutation-based non-parametric testing, forming clusters at t > 2.3 and testing clusters for significance at P < 0.05, corrected for multiple comparisons across space, revealed significantly lower grey matter density in the patients with fibromyalgia and marked fatigue in the left supplementary motor area. This brain region plays an important role in cognitive or executive control and in the translation of painful cognition; these functions are impaired in fibromyalgia associated with marked fatigue.


Assuntos
Encéfalo/patologia , Fadiga/complicações , Fadiga/patologia , Fibromialgia/complicações , Fibromialgia/patologia , Imageamento por Ressonância Magnética , Transtornos do Humor/complicações , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Projetos Piloto
5.
Med Hypotheses ; 124: 40-41, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30798914

RESUMO

Modern diets have become increasingly rich in fructose, for example through the addition of high-fructose corn syrup to many foods and drinks. It has been suggested that this might lead to hepatotoxicity, including the development of non-alcoholic fatty liver disease. After entering hepatocytes via insulin-independent glucose transporter 2 transmembrane carrier proteins, fructose is phosphorylated to fructose-1-phosphate in a reaction catalysed by fructokinase (ketohexokinase). In turn, fructose-1-phosphate is hydrolysed by aldolase B to glyceraldehydes. Glyceraldehydes may enter gluconeogenesis via fructose-1,6-bisphosphate and fructose-6-phosphate; glyceraldehydes may also enter glycogenolysis via pyruvate. The last pathway involves conversion of pyruvate to acetyl-CoA. Alternatively, pyruvate may be converted, via the action of the hepatic lactate dehydrogenase isoenzyme LDH-5, into lactate. In liver damage, the LDH-5 isoenzyme becomes elevated, predominantly in serum/plasma. We therefore hypothesised that if dietary fructose is associated with hepatotoxicity, there should be a positive correlation between erythrocyte fructose-6-phosphate and plasma LDH-5. This hypothesis was tested by assaying venous blood samples taken from 39 patients at rest, three hours after eating. Quantitative Fourier transform infrared spectrometry following gel electrophoresis was used to assay erythrocyte fructose-6-phosphate levels. Similarly, plasma LDH-5 concentrations were spectrophotometrically analysed, using the pyruvate-lactate reaction, following electrophoretic separation of the LDH isoenzymes. A significant positive correlation was found between the two variables (r = 0.44, p = 0.0047). This result, which supports our hypothesis, is evidence in favour of the possibility that dietary fructose is associated with hepatotoxicity. In addition to being a marker of hepatic damage, LDH-5 may play a more direct epigenetic role in causing liver damage; acute hepatic injury is associated with nuclear translocation of LDH, causing the production of lactate from pyruvate in the nucleus; in turn, the lactate inhibits histone deacetylase and is associated with upregulation of genes associated with the damage response, leading to cell death.


Assuntos
Frutose/efeitos adversos , L-Lactato Desidrogenase/metabolismo , Fígado/efeitos dos fármacos , Adulto , Animais , Epigênese Genética , Eritrócitos/enzimologia , Feminino , Frutoquinases/metabolismo , Gluconeogênese , Xarope de Milho Rico em Frutose/efeitos adversos , Humanos , Isoenzimas/metabolismo , Lactato Desidrogenase 5 , Fígado/enzimologia , Masculino , Camundongos , Fosforilação , Projetos Piloto , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Med Hypotheses ; 127: 11-14, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31088632

RESUMO

DNA adducts are associated with a number of diseases, including cancer. Based on a recent report by our group, the aim of this study was to test the hypothesis that DNA adducts can be removed by means of one or more of the following three intervention programmes: intermittent whole-body hyperthermia; detoxification; and cell repair. The number of DNA adducts and total DNA adduct concentrations were measured in 104 patients who underwent one or more of the three intervention programmes. DNA adduct assessments were carried out on extracted genomic DNA by gas-liquid chromatography, with any DNA adducts found being localised using DNA microarrays. The baseline median number of DNA adducts was 2. The follow-up median number of adducts was highly significantly lower at 0 (p < 0.000000000000003). The mean total DNA adduct concentration at baseline was 9.308 ng/mL, and highly significantly lower at follow-up at 1.553 ng/mL (p < 0.000000000000006). Of the three intervention programmes, only the intermittent whole-body hyperthermia was associated with a significant reduction in DNA adducts. This study offers support for the hypothesis that DNA adducts can be removed by intermittent whole-body hyperthermia. The intermittent hyperthermia used involved infrared-A (wavelength 700-1400 nm, or, equivalently, a frequency of 215-430 THz) being preferentially delivered to the whole body, apart from the head, for up to one hour per session, with gradual core body temperature elevation usually occurring during the first 20-30 min. These results may offer an explanation at the molecular level for other reported clinical benefits of intermittent whole-body hyperthermia.


Assuntos
Adutos de DNA/isolamento & purificação , Hipertermia Induzida/métodos , Administração Intravenosa , Cromatografia Gasosa , Ácidos Graxos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Neoplasias/genética , Neoplasias/terapia , Análise de Sequência com Séries de Oligonucleotídeos , Doença de Parkinson/terapia , Fosfolipídeos/administração & dosagem , Reprodutibilidade dos Testes
8.
Artigo em Inglês | MEDLINE | ID: mdl-18842398

RESUMO

This study directly assessed, for the first time, whether there was a change in brain cell motion-restricted membrane phospholipids in vivo in patients with schizophrenia with mild to moderate negative symptoms, by quantification of the underlying broad resonance signal of cerebral 31-phosphorus magnetic resonance scans. Cerebral 31-phosphorus magnetic resonance spectroscopy was carried out in 16 schizophrenia patients and 16 age- and gender-matched normal controls. Spectra were obtained from 70x70x70 mm3 voxels using an image-selected in vivo spectroscopy pulse sequence. There was no significant difference in the broad resonances between the two groups, with the mean (S.E.) percentage signal being 59.4 (5.6) for the patients and 53.5 (5.9) for the controls. The phosphomonoesters and phosphodiesters narrow signals also did not differ significantly, their ratio being 0.26 (0.01) in the patients and 0.25 (0.01) in the controls. These results appear to be at variance with the changes expected under the membrane phospholipid hypothesis of schizophrenia.


Assuntos
Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Fosfolipídeos/metabolismo , Esquizofrenia/metabolismo , Encéfalo/patologia , Humanos , Lipídeos de Membrana/metabolismo , Radioisótopos de Fósforo , Esquizofrenia/patologia
9.
J Int Med Res ; 36(2): 268-72, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18380936

RESUMO

A systematic, prospective observer-rated study was carried out to determine the prevalence of late luteal phase dysphoric disorder (premenstrual syndrome) in women with autism. A group of women with autism and learning disability (n = 26) was compared with a group of women with a non-autism learning disability (n = 36) matched for age, in-patient status, intelligence, marital status, parity, behavioural problems and ethnicity. Observers rated DSM-IV symptoms of late luteal phase dysphoric disorder every day from each subject over three consecutive menstrual cycles. Using a premenstrual increase in DSM-IV symptoms of >or= 30% as evidence of fulfilment of diagnostic criteria, the prevalence of late luteal phase dysphoric disorder was 92% in the autism group compared with 11% in the control group. This difference was highly statistically significant. The principal conclusion from this study is that there is a marked increase in premenstrual syndrome in women with autism compared with matched controls.


Assuntos
Transtorno Autístico/epidemiologia , Síndrome Pré-Menstrual/epidemiologia , Adolescente , Adulto , Transtorno Autístico/complicações , Transtorno Autístico/diagnóstico , Estudos Transversais , Inglaterra/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Síndrome Pré-Menstrual/complicações , Síndrome Pré-Menstrual/diagnóstico , Prevalência , Estudos Prospectivos
10.
J Int Med Res ; 36(5): 896-905, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18831882

RESUMO

Ultra-pure ethyl-eicosapentaenoic acid (ethyl-EPA), a semi-synthetic ethyl ester of eicosapentaenoic acid, is associated with clinical improvement in motor functioning in Huntington's disease. The aim was to determine the extent to which it might reduce the rate of progress of cerebral atrophy. High-resolution cerebral magnetic resonance imaging scans were acquired at baseline, 6 months and 1 year in up to 34 patients with stage I or II Huntington's disease who took part in a randomized, double-blind, placebo-controlled trial of ethyl-EPA. For each subject and each pair of structural images, the two-timepoint brain volume change was calculated in a double-blind manner. Significant group-level reductions in brain atrophy were observed in the head of the caudate nucleus and the posterior thalamus. These findings show that treatment with ethyl-EPA is associated with significant reduction in brain atrophy, particularly in the caudate and thalamus. No other drug tested in Huntington's disease has shown this effect.


Assuntos
Atrofia , Córtex Cerebral , Ácido Eicosapentaenoico/análogos & derivados , Doença de Huntington , Animais , Atrofia/tratamento farmacológico , Atrofia/patologia , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Método Duplo-Cego , Ácido Eicosapentaenoico/farmacologia , Ácido Eicosapentaenoico/uso terapêutico , Feminino , Humanos , Doença de Huntington/tratamento farmacológico , Doença de Huntington/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Placebos
11.
Med Hypotheses ; 112: 60-62, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29447940

RESUMO

The non-invasive assessment of chronic tissue hypoxia is difficult. Pulse oximetry only allows the peripheral oxygen saturation to be measured, while the detection of hyperlactataemia needs to take into account the fact that the accumulation of lactic acid may result from several causes other than prolonged tissue hypoxia. Arterial blood oxygen measurement is invasive and often does not give a good indication of the level of tissue hypoxia. Other suggested methods include the use of positron emission tomography, magnetic resonance T2∗ relaxation time measurement, photoacoustics and high-frequency ultrasound. Tissue hypoxia leads to increased levels of hypoxia-inducible factor-1α, which in turn upregulates VEGFA, leading to increased levels of vascular endothelial growth factor (VEGF), which promote angiogenesis. Hypoxia lasting for more than a few hours is associated with increased synthesis in erythrocytes of 2,3-bisphosphoglycerate (BPG), a powerful regulator of the allosteric properties of haemoglobin, via the Rapoport-Luebering phosphoglycerate cycle. We therefore hypothesised that plasma VEGF and erythrocyte BPG levels should be positively correlated. Venous blood samples from 34 patients (18 male, mean age (standard error) 43.4 (3.2) y) were analysed; plasma VEGF was measured using an enzyme-linked immunosorbent assay while the erythrocyte BPG was assessed by quantitative Fourier transform infrared spectrometry following gel electrophoresis. The Pearson product-moment correlation between the two variables was 0.622 (p < 0.0001). Based on our findings, we suggest that it may be useful to measure both erythrocyte BPG and plasma VEGF, together, when assessing chronic hypoxia; elevated levels of both are likely to indicate hypoxia.


Assuntos
2,3-Difosfoglicerato/sangue , Eritrócitos/metabolismo , Hipóxia/sangue , Modelos Biológicos , Fator A de Crescimento do Endotélio Vascular/sangue , Adulto , Regulação Alostérica , Biomarcadores , Doença Crônica , Ensaio de Imunoadsorção Enzimática , Feminino , Hemoglobinas/metabolismo , Humanos , Lactatos/sangue , Masculino , Pessoa de Meia-Idade , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Med Hypotheses ; 121: 164-166, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30396473

RESUMO

In muscle cells, fructose is initially metabolised to fructose-6-phosphate. In the liver, fructose is metabolised to fructose-1-phosphate and thence to glyceraldehydes, which in turn can either enter glycogenolysis via pyruvate or gluconeogenesis via fructose-1,6-bisphosphate and fructose-6-phosphate. High levels of fructose-1-phosphate inhibit both glycogenolysis and gluconeogenesis. We hypothesised that, if systemically absorbed short-chain fatty acids constitute a major metabolic fate of unabsorbed dietary fructose, then levels of erythrocyte fructose-6-phosphate would be inversely correlated with plasma levels of short-chain fatty acids. The aim of this study was to test this hypothesis in respect of the three main short-chain fatty acids acetate, propionate and butyrate. Venous blood samples from 39 patients (16 male, 23 female, mean (standard error) age 42.4 (3.3) years) were analysed. Erythrocyte fructose-6-phosphate was measured using quantitative Fourier transform infrared spectrometry following gel electrophoresis, while plasma acetate, propionate and butyrate levels were measured using gas-liquid chromatography. The erythrocyte fructose-6-phosphate level was inversely correlated with the plasma acetate (r = -0.30, p = 0.06), propionate (r = -0.31, p = 0.05) and butyrate (r = -0.40, p = 0.01). These results support our hypothesis. The conversion of unabsorbed dietary fructose into short-chain fatty acids may represent a protective mechanism against the adverse effects of hypoglycaemia.


Assuntos
Eritrócitos/metabolismo , Ácidos Graxos Voláteis/sangue , Frutosefosfatos/sangue , Adulto , Cromatografia Gasosa , Açúcares da Dieta , Feminino , Fermentação , Frutose/química , Gluconeogênese , Glucose/metabolismo , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Propionatos , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Med Hypotheses ; 110: 101-104, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29317050

RESUMO

Oxygen therapy, usually administered by a facemask or nasal cannulae, is the current default treatment of respiratory failure. Since respiration entails intake of oxygen and release of carbon dioxide from tissues as waste product, the notion of administering carbon dioxide in respiratory failure appears counter-intuitive. However, carbon dioxide stimulates the chemosensitive area of the medulla, known as the central respiratory chemoreceptor, which activates the respiratory groups of neurones in the brainstem and stimulates inspiration thereby initiating oxygen intake during normal breathing. This vital initiation of normal breathing is via a reduction in the pH of the cerebrospinal fluid and the medullary interstitial fluid. We hypothesise that in cases of type I respiratory failure in which the PaCO2 is low, administration of carbon dioxide by inhalation would stimulate the respiratory groups of brainstem neurones and facilitate breathing, which would be of therapeutic value. Preliminary clinical evidence in favour of this hypothesis is presented and we recommend that a formal randomised study be carried out.


Assuntos
Dióxido de Carbono/uso terapêutico , Hipocapnia/terapia , Insuficiência Respiratória/terapia , Administração por Inalação , Adulto , Dióxido de Carbono/administração & dosagem , Dióxido de Carbono/sangue , Células Quimiorreceptoras/fisiologia , Feminino , Humanos , Hipocapnia/complicações , Hipocapnia/fisiopatologia , Modelos Biológicos , Oxigenoterapia , Centro Respiratório/fisiopatologia , Insuficiência Respiratória/complicações , Insuficiência Respiratória/fisiopatologia
14.
Mol Neurobiol ; 55(6): 4834-4856, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28733900

RESUMO

Exposure to organic forms of mercury has the theoretical capacity to generate a range of immune abnormalities coupled with chronic nitro-oxidative stress seen in children with autism spectrum disorder (ASD). The paper discusses possible mechanisms explaining the neurotoxic effects of mercury and possible associations between mercury exposure and ASD subtypes. Environmental mercury is neurotoxic at doses well below the current reference levels considered to be safe, with evidence of neurotoxicity in children exposed to environmental sources including fish consumption and ethylmercury-containing vaccines. Possible neurotoxic mechanisms of mercury include direct effects on sulfhydryl groups, pericytes and cerebral endothelial cells, accumulation within astrocytes, microglial activation, induction of chronic oxidative stress, activation of immune-inflammatory pathways and impairment of mitochondrial functioning. (Epi-)genetic factors which may increase susceptibility to the toxic effects of mercury in ASD include the following: a greater propensity of males to the long-term neurotoxic effects of postnatal exposure and genetic polymorphisms in glutathione transferases and other glutathione-related genes and in selenoproteins. Furthermore, immune and inflammatory responses to immunisations with mercury-containing adjuvants are strongly influenced by polymorphisms in the human leukocyte antigen (HLA) region and by genes encoding effector proteins such as cytokines and pattern recognition receptors. Some epidemiological studies investigating a possible relationship between high environmental exposure to methylmercury and impaired neurodevelopment have reported a positive dose-dependent effect. Retrospective studies, on the other hand, reported no relationship between a range of ethylmercury-containing vaccines and chronic neuropathology or ASD. On the basis of these results, we would argue that more clinically relevant research is required to examine whether environmental mercury is associated with ASD or subtypes. Specific recommendations for future research are discussed.


Assuntos
Transtorno do Espectro Autista/etiologia , Exposição Ambiental/efeitos adversos , Mercúrio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Humanos
15.
Mol Neurobiol ; 55(7): 5767-5786, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29052145

RESUMO

In the first part, the following mechanisms involved in different forms of cell death are considered, with a view to identifying potential therapeutic targets: tumour necrosis factor receptors (TNFRs) and their engagement by tumour necrosis factor-alpha (TNF-α); poly [ADP-ribose] polymerase (PARP)-1 cleavage; the apoptosis signalling kinase (ASK)-c-Jun N-terminal kinase (JNK) axis; lysosomal permeability; activation of programmed necrotic cell death; oxidative stress, caspase-3 inhibition and parthanatos; activation of inflammasomes by reactive oxygen species and the development of pyroptosis; oxidative stress, calcium dyshomeostasis and iron in the development of lysosomal-mediated necrosis and lysosomal membrane permeability; and oxidative stress, lipid peroxidation, iron dyshomeostasis and ferroptosis. In the second part, there is a consideration of the role of lethal and sub-lethal activation of these pathways in the pathogenesis and pathophysiology of neurodegenerative and neuroprogressive disorders, with particular reference to the TNF-α-TNFR signalling axis; dysregulation of ASK-1-JNK signalling; prolonged or chronic PARP-1 activation; the role of pyroptosis and chronic inflammasome activation; and the roles of lysosomal permeabilisation, necroptosis and ferroptosis. Finally, it is suggested that, in addition to targeting oxidative stress and inflammatory processes generally, neuropsychiatric disorders may respond to therapeutic targeting of TNF-α, PARP-1, the Nod-like receptor NLRP3 inflammasome and the necrosomal molecular switch receptor-interacting protein kinase-3, since their widespread activation can drive and/or exacerbate peripheral inflammation and neuroinflammation even in the absence of cell death. To this end, the use is proposed of a combination of the tetracycline derivative minocycline and N-acetylcysteine as adjunctive treatment for a range of neuropsychiatric disorders.


Assuntos
Apoptose , Terapia de Alvo Molecular , Neurociências , Animais , Humanos , Doenças do Sistema Nervoso/patologia , Doenças do Sistema Nervoso/terapia , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
16.
Med Hypotheses ; 116: 30-32, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29857904

RESUMO

Systemic arterial hypertension, a well-known cause of morbidity, is associated with dysfunction of the autonomic nervous system. Neuromuscular taping (also known as kinesio taping, medical taping and Vendje neuromuscular) allows movement and muscle activity to treat pain, muscle disorders and lymphoedema, in which its mode of action may involve muscular stimulation leading to increased local blood circulation or stimulating dermatological, muscular and fascial structures with a form of passive massage. We hypothesised that neuromuscular taping may reduce blood pressure in systemic arterial hypertension. This hypothesis was tested by carrying out the first pilot study of its kind to determine whether the non-invasive technique of neuromuscular taping can reduce blood pressure in patients suffering from systemic arterial hypertension. Neuromuscular taping was symmetrically applied to the back, between C1 and T2, of seven hypertensive patients for 5-7 days. Cardiovascular autonomic parameters were assessed at baseline and at the end of the study. Taping was associated with falls in mean arterial blood pressure (p = .001), mean systolic blood pressure (p < .01), mean diastolic pressure (p < .01) and cardiac vagal tone at rest (p = .063). The beneficial effects on blood pressure appeared to last for at least five days post-neuromuscular taping. There is an indication, given the reduction in cardiac vagal tone at rest, that the mechanism of action of this intervention involves modulation of the brainstem parasympathetic system during cardiovascular control. Further studies are indicated to replicate the present findings, further investigate the effects of taping on autonomic functioning, and establish the optimum time-period and taping positioning.


Assuntos
Fita Atlética , Sistema Nervoso Autônomo , Dorso , Pressão Sanguínea , Hipertensão/terapia , Adulto , Determinação da Pressão Arterial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Projetos Piloto , Software , Sístole
17.
J Clin Pathol ; 60(2): 122-4, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16935966

RESUMO

Evidence is put forward to suggest that myalgic encephalomyelitis, also known as chronic fatigue syndrome, may be associated with persistent viral infection. In turn, such infections are likely to impair the ability of the body to biosynthesise n-3 and n-6 long-chain polyunsaturated fatty acids by inhibiting the delta-6 desaturation of the precursor essential fatty acids--namely, alpha-linolenic acid and linoleic acid. This would, in turn, impair the proper functioning of cell membranes, including cell signalling, and have an adverse effect on the biosynthesis of eicosanoids from the long-chain polyunsaturated fatty acids dihomo-gamma-linolenic acid, arachidonic acid and eicosapentaenoic acid. These actions might offer an explanation for some of the symptoms and signs of myalgic encephalomyelitis. A potential therapeutic avenue could be offered by bypassing the inhibition of the enzyme delta-6-desaturase by treatment with virgin cold-pressed non-raffinated evening primrose oil, which would supply gamma-linolenic acid and lipophilic pentacyclic triterpenes, and with eicosapentaenoic acid. The gamma-linolenic acid can readily be converted into dihomo-gamma-linolenic acid and thence arachidonic acid, while triterpenes have important free radical scavenging, cyclo-oxygenase and neutrophil elastase inhibitory activities. Furthermore, both arachidonic acid and eicosapentaenoic acid are, at relatively low concentrations, directly virucidal.


Assuntos
Síndrome de Fadiga Crônica/metabolismo , Ácidos Graxos Insaturados/biossíntese , Ácido Eicosapentaenoico/uso terapêutico , Síndrome de Fadiga Crônica/tratamento farmacológico , Síndrome de Fadiga Crônica/imunologia , Síndrome de Fadiga Crônica/virologia , Humanos , Ácidos Linoleicos/uso terapêutico , Lipídeos de Membrana/imunologia , Oenothera biennis , Fosfolipídeos/imunologia , Óleos de Plantas/uso terapêutico , Viroses/imunologia , Ácido gama-Linolênico/uso terapêutico
18.
Artigo em Inglês | MEDLINE | ID: mdl-17764919

RESUMO

The concern that evening primrose oil might cause epilepsy or seizures, or reduce the threshold for seizures, originated from two papers published in the early 1980s. These original reports are re-examined, and the association of evening primrose oil with seizures is shown to be spurious. Not only are linoleic acid and gamma-linolenic acid safe in epilepsy, with prolonged oral administration of linoleic acid and alpha-linolenic acid (in a 4:1 mixture) protecting rats from having seizures in four different epilepsy models, but the evening primrose oil-derived omega-6 fatty acid arachidonic acid inhibits sodium ion currents and synaptic transmission, while the evening primrose oil-derived eicosanoid prostaglandin E(1) appears to have anticonvulsant activity. In light of these findings, it is suggested that formularies should now remove seizures or epilepsy as a side-effect of evening primrose oil, and should remove a history of seizures or epilepsy as a contraindication to taking evening primrose oil.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Epilepsia/induzido quimicamente , Ácidos Linoleicos/efeitos adversos , Óleos de Plantas/efeitos adversos , Ácido gama-Linolênico/efeitos adversos , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Humanos , Ácidos Linoleicos/administração & dosagem , Oenothera biennis , Óleos de Plantas/administração & dosagem , Ratos , Ácido gama-Linolênico/administração & dosagem
19.
Artigo em Inglês | MEDLINE | ID: mdl-17761409

RESUMO

The aim of this study was to determine whether supplementation with the n-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid in patients with chronic refractory epilepsy is associated with beneficial changes in cerebral biochemistry. In a 3-month pilot randomized double-blind placebo-controlled study, three patients received eicosapentaenoic acid and docosahexaenoic acid daily and four received a placebo. 31-Phosphorus neurospectroscopy showed a decrease in phosphodiesters, an increase in gammaNTP and an increase in the broadband component in the active group over this period, while the opposite changes occurred in the placebo group. Therefore, in chronic refractory epilepsy, omega-3 supplementation may be associated with reduced membrane phospholipid breakdown in the brain, an improvement in brain energy metabolism, and an increased level of phospholipids in membranes and/or vesicle bilayers in cells in the brain. The unfavourable biochemical changes observed in the placebo group may be a feature of chronic intractable epilepsy.


Assuntos
Encéfalo/metabolismo , Ácidos Docosa-Hexaenoicos , Ácido Eicosapentaenoico , Epilepsia/tratamento farmacológico , Ácidos Graxos Ômega-3 , Adulto , Idoso , Encéfalo/anatomia & histologia , Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácido Eicosapentaenoico/metabolismo , Ácido Eicosapentaenoico/uso terapêutico , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Ômega-3/uso terapêutico , Humanos , Espectroscopia de Ressonância Magnética , Pessoa de Meia-Idade , Projetos Piloto , Placebos
20.
Artigo em Inglês | MEDLINE | ID: mdl-17765531

RESUMO

The aim of the study was to examine the association of arachidonic acid-related signal transduction with cerebral metabolism in patients with schizophrenia who have violently and dangerously offended while psychotic. Cerebral 31-phosphorus magnetic resonance spectroscopy was carried out in 11 male patients with schizophrenia who had violently offended (homicide, attempted murder, or wounding with intent to cause grievous bodily harm) while psychotic. Spectra were obtained from 70 x 70 x 70 mm(3) voxels using an image-selected in vivo spectroscopy pulse sequence. Niacin flush testing results were quantified as the volumetric niacin response. There was a strong, and negative, correlation between the volumetric niacin response and the metabolite concentration of inorganic phosphate expressed as a ratio of the total 31-phosphorus signal (p<0.005). Our results suggest that patients with schizophrenia who have violently offended and have poor phospholipid-related signal transduction may have higher levels of cerebral energy metabolism.


Assuntos
Córtex Cerebral/química , Niacina/metabolismo , Fosfatos/metabolismo , Esquizofrenia/metabolismo , Violência , Adulto , Córtex Cerebral/metabolismo , Rubor , Humanos , Imageamento por Ressonância Magnética , Masculino , Fosfatos/química , Testes Cutâneos , Estatística como Assunto
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