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2.
J Neurol Sci ; 457: 122896, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38290377

RESUMO

BACKGROUND: Information on the incidence and risk factors of deep vein thrombosis (DVT) in neurodegenerative diseases is limited. We aimed to determine the incidence of DVT among neurodegenerative disorders (amyotrophic lateral sclerosis [ALS], Parkinson's disease [PD], multiple system atrophy [MSA], and progressive supranuclear palsy [PSP]-corticobasal syndrome [CBS]) and the risk factors for the development of DVT. METHODS: Overall, 229 hospitalized patients with neurodegenerative diseases (65 patients with ALS, 61 with PD, 53 with MSA, and 50 with PSP-CBS) were included in this study. D-dimer value and ultrasonography of the leg vein were assessed to determine the presence or absence of leg DVT. We compared the DVT incidence among each disease group. To identify the risk factors for DVT, a multivariate analysis was performed. RESULTS: Of 229 patients, 34 had leg DVT; the incidence was significantly higher in patients with PD (38%) than in those with ALS (2%), MSA (5%), or PSP-CBS (4%). Patients with DVT were older, had a smaller waist circumference, had a longer disease duration, and had a high blood pressure (BP) variability. Multivariate analysis revealed that a PD diagnosis and female sex, with a high BP variability were predictive of leg DVT. CONCLUSIONS: Among the neurodegenerative diseases, the DVT incidence was markedly higher in PD than in ALS, MSA, and PSP-CBS. Several risk factors have been identified in patients with leg DVT. Recognition of these risk factors will improve patient care and guide the appropriate use of anticoagulants.


Assuntos
Esclerose Lateral Amiotrófica , Atrofia de Múltiplos Sistemas , Doença de Parkinson , Paralisia Supranuclear Progressiva , Trombose Venosa , Humanos , Feminino , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/epidemiologia , Incidência , Fatores de Risco , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/epidemiologia
3.
Clin Ther ; 45(12): 1251-1258, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37953075

RESUMO

PURPOSE: Edaravone is a neuroprotective agent approved as an intravenous treatment for amyotrophic lateral sclerosis (ALS). The intravenous administration of edaravone places a burden on patients and there is a clinical need for oral agents for the treatment of ALS. This report aimed to assess the pharmacokinetics and safety of an edaravone oral suspension in patients with ALS after oral and percutaneous endoscopic gastrostomy (PEG) tube administration. METHODS: Two single-dose, open-label phase 1 clinical studies were conducted. Edaravone oral suspension (105 mg of edaravone in 5 mL aqueous suspension) was administered orally and via PEG tube to 9 and 6 Japanese patients with ALS, respectively. Plasma and urinary pharmacokinetics of unchanged edaravone and its metabolites (sulfate and glucuronide conjugates) were determined. Safety was also evaluated. FINDINGS: After reaching maximum plasma concentration, the mean plasma concentration-time of unchanged edaravone showed a triphasic elimination. Mean plasma concentration-time profiles of the metabolites were higher than those of unchanged edaravone. The mean urinary excretion ratios were higher for the glucuronide conjugate than for either unchanged edaravone or the sulfate conjugate. In patients administered edaravone orally, a single adverse event occurred (blood urine present), which was mild and improved without medical intervention. No adverse drug reactions or serious adverse events were reported. In patients administered edaravone via PEG tube, 5 treatment-emergent adverse events were reported in 3 patients; none were related to the study drug. No adverse drug reactions were reported. IMPLICATIONS: In patients with ALS, a single dose of edaravone oral suspension was well absorbed and mainly eliminated in urine as the glucuronide conjugate. No safety concerns emerged. Pharmacokinetics were similar to those previously reported in healthy participants following oral administration. This indicates that effective drug concentrations were achieved and edaravone can be successfully administered both orally and via a PEG tube in patients with ALS. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT04176224 (oral administration) and NCT04254913 (PEG tube administration), www. CLINICALTRIALS: gov.


Assuntos
Esclerose Lateral Amiotrófica , Fármacos Neuroprotetores , Humanos , Esclerose Lateral Amiotrófica/tratamento farmacológico , Edaravone/farmacocinética , Glucuronídeos/uso terapêutico , Fármacos Neuroprotetores/farmacocinética , Sulfatos/uso terapêutico
4.
Neurology ; 99(16): 699-702, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36253132

RESUMO

OBJECTIVES: Currently, no established biomarkers exist for presymptomatic sporadic Creutzfeldt-Jakob disease (sCJD). The purpose of this study was to raise awareness about sCJD cases showing abnormalities on brain MRI diffusion-weighted imaging (DWI) before symptom onset and demonstrate temporal changes in DWI abnormalities during the preclinical period. METHODS: We described the clinical presentation including the results of MRI-performed multiple times in the preclinical period-and the diagnostic workup of a middle-aged man with sCJD. RESULTS: MRI of the brain performed 27 months before symptom onset revealed an extremely localized lesion on DWI in the right occipital cortex. Follow-up MRI scans showed propagation of DWI abnormalities along the cortices without the appearance of neurologic symptoms/signs. After symptom onset, the patient's neuropsychiatric condition rapidly deteriorated. Elevated total tau protein levels and positive 14-3-3 protein were observed in the CSF, and periodic synchronous discharges using electroencephalography resulted in the diagnosis of sCJD. DISCUSSION: CJD should be considered in differential diagnoses when localized DWI signal abnormalities propagate along the cortices over time, even in the absence of typical CJD symptoms. DWI signal abnormalities on brain MRI scans may be highly sensitive diagnostic markers for CJD, even in the preclinical stage.


Assuntos
Síndrome de Creutzfeldt-Jakob , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas 14-3-3 , Biomarcadores , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Síndrome de Creutzfeldt-Jakob/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Eletroencefalografia , Proteínas tau
5.
J Neurol ; 269(10): 5497-5509, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35708789

RESUMO

OBJECTIVE: This study aimed to clarify the relationship between progressive medial temporal atrophy and onset subtype in patients with amyotrophic lateral sclerosis (ALS). METHODS: Medial temporal atrophy, ALS functional rating scale (ALSFRS), and cognitive function were assessed in 119 patients who were grouped into three ALS subtypes: bulbar, upper limb, and lower limb onset. Medial temporal atrophy, represented by a Z-score, was determined using an analysis software of magnetic resonance images known as the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD). Among 119 patients, 60 underwent follow-up VSRAD, ALSFRS, and cognitive testing. The sequential data were compared among onset subtypes. Furthermore, TDP-43 pathology was assessed in 20 autopsied patients (including seven who underwent VSRAD before death) to examine the relationships among medial temporal atrophy, onset subtypes, and severity of the hippocampal TDP-43 pathology. RESULTS: Multiple regression analysis revealed that the Z-score at baseline was associated with the age of onset and duration of illness. A high Z-score at baseline and the bulbar/upper limb subtypes affected the progression rate of Z-score. Pathological examination revealed increased hippocampal TDP-43 pathology score associated with bulbar and upper limb subtypes. Moreover, the Z-score before death correlated with the hippocampal TDP-43 pathology score. CONCLUSION: Medial temporal atrophy in ALS is associated with bulbar and upper limb onset subtypes. This progression may be related to the extent of TDP-43 pathology.


Assuntos
Esclerose Lateral Amiotrófica , Proteínas de Ligação a DNA/metabolismo , Esclerose Lateral Amiotrófica/complicações , Esclerose Lateral Amiotrófica/diagnóstico por imagem , Esclerose Lateral Amiotrófica/patologia , Atrofia/patologia , Humanos , Imageamento por Ressonância Magnética , Extremidade Superior
6.
BMC Neurol ; 21(1): 273, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34243731

RESUMO

BACKGROUND: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease. Pathologically, it is characterized by eosinophilic hyaline intranuclear inclusions in the cells of the visceral organs as well as central, peripheral, and autonomic nervous system cells. Recently, a GGC repeat expansion in the NOTCH2NLC gene has been identified as the etiopathological agent of NIID. Interestingly, this GGC repeat expansion was also reported in some patients with a clinical diagnosis of amyotrophic lateral sclerosis (ALS). However, there are no autopsy-confirmed cases of concurrent NIID and ALS. CASE PRESENTATION: A 60-year-old Taiwanese woman reported a four-month history of progressive weakness beginning in the right foot that spread to all four extremities. She was diagnosed with ALS because she met the revised El Escorial diagnostic criteria for definite ALS with upper and lower motor neuron involvement in the cervical, thoracic, and lumbosacral regions. She died of respiratory failure at 22 months from ALS onset, at the age of 62 years. Brain magnetic resonance imaging (MRI) revealed lesions in the medial part of the cerebellar hemisphere, right beside the vermis (paravermal lesions). The subclinical neuropathy, indicated by a nerve conduction study (NCS), prompted a potential diagnosis of NIID. Antemortem skin biopsy and autopsy confirmed the coexistence of pathology consistent with both ALS and NIID. We observed neither eccentric distribution of p62-positive intranuclear inclusions in the areas with abundant large motor neurons nor cytopathological coexistence of ALS and NIID pathology in motor neurons. This finding suggested that ALS and NIID developed independently in this patient. CONCLUSIONS: We describe a case of concurrent NIID and ALS discovered during an autopsy. Abnormal brain MRI findings, including paravermal lesions, could indicate the coexistence of NIID even in patients with ALS showing characteristic clinical phenotypes.


Assuntos
Esclerose Lateral Amiotrófica , Doenças Neurodegenerativas , Esclerose Lateral Amiotrófica/complicações , Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Feminino , Humanos , Corpos de Inclusão Intranuclear/patologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Doenças Neurodegenerativas/complicações , Doenças Neurodegenerativas/diagnóstico , Doenças Neurodegenerativas/patologia
7.
Intern Med ; 60(16): 2671-2675, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33642484

RESUMO

We herein report a case of seronegative immune-mediated necrotizing myopathy (IMNM) concurrent with anti-Kv1.4 and anti-titin antibodies. A 72-year-old Japanese woman presented with a 29-year history of fluctuating high serum creatine kinase (CK) levels followed by intermittent ptosis and respiratory muscle weakness. This case highlights the fact that marked respiratory muscle weakness requiring intubation can be seen in an ambulant patient with IMNM. Marked respiratory muscle weakness, rhabdomyolysis-like acute elevation of CK levels, and anti-striational muscle antibodies may be a characteristic constellation of findings in a distinct subgroup of patients with inflammatory myopathy with myasthenia gravis or similar symptoms.


Assuntos
Doenças Musculares , Miastenia Gravis , Miosite , Insuficiência Respiratória , Idoso , Autoanticorpos , Feminino , Humanos , Debilidade Muscular/etiologia , Miastenia Gravis/complicações , Insuficiência Respiratória/etiologia
8.
Aliment Pharmacol Ther ; 53(1): 103-113, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33159485

RESUMO

BACKGROUND: Although 5-aminosalicylate (5-ASA) is the therapy of first choice in ulcerative colitis (UC), some patients cannot tolerate it because of side effects. Previous reports have not investigated whether 5-ASA intolerance is associated with the risk of colectomy. AIM: To investigate the associations between 5-ASA tolerance and colectomy among UC patients METHODS: The data of UC patients who visited any of three hospitals during 2014-2018 in and around Tokyo, Japan, were retrospectively obtained from the medical records. Patients were categorized as (a) tolerant to any 5-ASA compounds ("tolerant to 5-ASA") and (b) patients who were intolerant to one or more 5-ASA compounds leading to refrainment from their further use ("intolerant to 5-ASA"). The association between 5-ASA tolerance and colectomy was examined by Cox proportional hazards model adjusted for sex, age, smoking and extent of colitis. RESULTS: Of 1788 patients, 1684 were "tolerant to 5-ASA" while 104 were "intolerant to 5-ASA". Colectomy was performed in 43 (2.6%) of the patients tolerant to 5-ASA and 12 (11.5%) of the patients intolerant to 5-ASA. After adjusting for all covariates, the risk of undergoing colectomy was higher in the "intolerant to 5-ASA" group than in the "tolerant to 5-ASA" group (hazard ratio: 4.92; 95% confidence interval: 2.58-9.38). CONCLUSION: Patients in whom 5-ASA was discontinued due to intolerance had a higher risk of undergoing colectomy than patients tolerant to their first, second or third 5-ASA compounds.


Assuntos
Colite Ulcerativa , Mesalamina , Colectomia , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/cirurgia , Humanos , Japão/epidemiologia , Mesalamina/efeitos adversos , Estudos Retrospectivos , Fatores de Risco
9.
Thyroid ; 28(8): 1071-1073, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29882472

RESUMO

To date, >100 mutations in NKX2-1 have been described. Most NKX2-1 mutations are assumed to result in brain-lung-thyroid syndrome through haploinsufficiency, and only five NKX2-1 mutations with dominant-negative effects have been reported so far. In this case report, an additional patient with brain-lung-thyroid syndrome is reported, carrying a novel heterozygous mutation, c.533G>C (p.R178P), in the homeobox of NKX2-1. This mutation has been proven to be a dominant-negative mutation by an in vitro functional assay. Of note, the dominant-negative effect of R178P-NKX2-1 was shown only in the presence of PAX8.


Assuntos
Hipotireoidismo Congênito/genética , Mutação , Fator de Transcrição PAX8/genética , Fator Nuclear 1 de Tireoide/genética , Criança , Hipotireoidismo Congênito/sangue , Feminino , Humanos , Lactente , Recém-Nascido , Tireotropina/sangue
10.
Pediatr Int ; 57(6): 1192-5, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26542099

RESUMO

Mondini dysplasia is rare, but has an important association with recurrent bacterial meningitis. We herein describe the case of a 3-year-old girl with unilateral sensorineural hearing loss who presented with three independent episodes of bacterial meningitis within 8 months. Temporal bone computed tomography indicated the characteristic features of Mondini dysplasia in the right inner ear. This was treated by surgical closure of the inner ear defect via oval window and additional vaccination was administered. Appropriate vaccination might prevent the recurrent bacterial meningitis associated with Mondini dysplasia.


Assuntos
Bactérias/isolamento & purificação , Perda Auditiva Neurossensorial/complicações , Histiocitose de Células de Langerhans/complicações , Hospedeiro Imunocomprometido , Meningites Bacterianas/complicações , Pré-Escolar , Feminino , Perda Auditiva Neurossensorial/diagnóstico , Histiocitose de Células de Langerhans/diagnóstico , Humanos , Meningites Bacterianas/diagnóstico , Meningites Bacterianas/microbiologia , Tomografia Computadorizada por Raios X
11.
J Med Food ; 18(8): 835-40, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25607850

RESUMO

It remains unclear whether dietary supplementation with coenzyme Q10 (CoQ10) provides beneficial effects for healthy individuals, especially young subjects. This study investigated the effects of dietary supplementation with CoQ10 on oxidative stress in healthy young females. We performed a placebo-controlled trial using a crossover design (n=28) with 100 mg/day CoQ10 in reduced form or placebo, each lasting 2 weeks with a 2-week interval. The urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a biomarker of oxidative DNA damage, were determined by high-performance liquid chromatography (HPLC) coupled to an electrochemical detector. Levels of malondialdehyde (MDA), a biomarker of lipid peroxidation, and antioxidant vitamin C in urine were also measured using a thiobarbituric acid-reactive substance method with a commercial kit and by the 2,4-dinitrophenylhydrazine method with HPLC, respectively. Urinary 8-oxodG levels during supplementation with reduced form of CoQ10 (median [first and third quartiles]: 1.76 [1.24-2.08] nmol/mmol creatinine) were significantly lower than those with placebo (2.00 [1.34-2.49] nmol/mmol creatinine, P=.031 by Student's paired t-test using the logarithmically transformed values). In contrast, the urinary levels of MDA and vitamin C were not significantly affected (P=.094 and P=.247 by Student's paired t-test, respectively). There was no evidence of any side effects. Supplementation with CoQ10 in the reduced form showed a slightly protective effect against oxidative DNA damage even in healthy young subjects.


Assuntos
Biomarcadores/urina , Dano ao DNA/efeitos dos fármacos , Desoxiguanosina/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Ubiquinona/análogos & derivados , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Antioxidantes/análise , Ácido Ascórbico/urina , Cromatografia Líquida de Alta Pressão , Estudos Cross-Over , Desoxiguanosina/urina , Suplementos Nutricionais , Feminino , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/urina , Resultado do Tratamento , Ubiquinona/administração & dosagem , Ubiquinona/farmacologia , Vitaminas/farmacologia , Adulto Jovem
12.
Exp Neurol ; 232(2): 149-53, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21906595

RESUMO

Fasciculations are characteristic features of amyotrophic lateral sclerosis (ALS), suggesting abnormally increased excitability of motor axons. Previous nerve excitability studies have shown reduced axonal potassium currents in ALS patients that may contribute to the hyperexcitability and thereby generation of fasciculations. To clarify changes in axonal ion channel expression in motor axons of ALS, we performed immunohistochemistry of potassium and sodium channels in the C7 and L5 ventral/dorsal roots obtained from five autopsy cases of sporadic ALS. Compared to controls, the immunoreactivity of potassium channels (Kv1.2) was markedly reduced in the ventral roots, but normal in the dorsal roots of all the ALS patients. Nodal sodium channel expression was not significantly different in ALS patients and control subjects. Our results show prominently reduced expression of axonal potassium channels, and provide the neuropathological and biological basis for decreased accommodative potassium currents in motor axons of ALS patients. The axonal hyperexcitability would lead to generation of fasciculations, and possibly enhances motor neuron death in ALS.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Axônios/metabolismo , Axônios/patologia , Canal de Potássio Kv1.2/metabolismo , Idoso , Idoso de 80 Anos ou mais , Fasciculação/metabolismo , Fasciculação/patologia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Agregação de Receptores/fisiologia , Canais de Sódio/metabolismo , Raízes Nervosas Espinhais/metabolismo
13.
Eur J Haematol ; 81(1): 70-4, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18462250

RESUMO

Neonatal alloimmune thrombocytopenia (NAIT) occurs because of transplacentally acquired maternal platelet alloantibodies. Most of the alloantibodies are against human platelet antigens, but the alloantibody against CD36 is rare. A full-term female baby was delivered by a mother who experienced two spontaneous abortions. The baby had thrombocytopenia with cephalhematoma. The platelet count increased by immunoglobulin therapy (400 mg/kg) for 3 d. Platelet antibody was detected in the postpartum maternal serum. The specificity of the antibody directed against platelets was identified as anti-Nak(a) (CD36). Flow cytometric analysis showed no expression of CD36 in both platelets and monocytes from mother. Mutation analysis revealed two different splicing isoforms of maternal CD36 mRNA. One allele was exon 4 skipping, another was exon 9 skipping, both of which led to a frameshift and produced a truncated CD36 protein. These results indicate that NAIT is caused by maternal CD36 deficiency having CD36 splicing abnormalities.


Assuntos
Antígenos CD36/genética , Trombocitopenia Neonatal Aloimune/etiologia , Feminino , Mutação da Fase de Leitura , Humanos , Lactente , Gravidez , Isoformas de Proteínas/genética , Splicing de RNA
14.
Acta Neuropathol ; 115(6): 623-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18427815

RESUMO

Tufted astrocytes (TAs) are considered reliable, specific markers for the neuropathologic diagnosis of progressive supranuclear palsy (PSP). It is known that neurofibrillary tangles (NFTs) may relate directly to neurodegeneration, but the role of glial tau pathology is not well determined. To examine the hypothesis that TAs are as pathogenic as NFTs and that both might have a common accumulation, we evaluated the topographic relationship between TAs and NFTs in 12 cases of PSP. The sections of 13 different parts of the brain were stained using the Gallyas-Braak method, and TAs and NFTs were counted and compared statistically. The number of TAs significantly correlated with that of NFTs in the central gray matter, pontine nuclei, and tegmentum, which are responsible for the main symptoms in PSP. In the examined allocortex, however, NFTs were abundant without accompanying TAs. Staining with the specific antibody for 4-repeat tau (RD4) and 3-repeat tau (RD3) was performed to clarify this discrepancy from the standpoint of tau isoforms. NFTs in the entorhinal cortex were stained with both RD3 and RD4, but NFTs in the premotor cortex were stained with only RD4. The nature of NFTs in the allocortical area was different from that of the isocortex in PSP. TAs in the isocortex may share the same pathologic cascade with NFTs stained only by RD4. These results suggest that TAs are part of the same pathologic process as NFTs in PSP.


Assuntos
Astrócitos/metabolismo , Emaranhados Neurofibrilares/patologia , Paralisia Supranuclear Progressiva/metabolismo , Paralisia Supranuclear Progressiva/patologia , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Free Radic Res ; 41(4): 461-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17454128

RESUMO

Increasing evidence reveals the carcinogenicity of UVA radiation. We demonstrated that UVA-irradiated NADH induced damage to (32)P-labeled DNA fragments obtained from the p53 gene in the presence of Cu(II). Formamidopyrimidine glycosylase (Fpg)-sensitive lesions were formed at guanine residues, whereas piperidine-labile lesions occurred frequently at thymine residues. Formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), upon UVA exposure in the presence of Cu(II), increased depending on NADH concentration. Catalase and bathocuproine, a Cu(I)-specific chelator, inhibited the DNA damage, suggesting the involvement of reactive species derived from H(2)O(2) and Cu(I). UVA-irradiated riboflavin induced DNA cleavage through electron transfer at 5' guanine of the 5'-GG-3' sequence with both Fpg and piperidine treatments; Fpg induced less cleavage at the guanine residues than piperidine. These results imply that NADH may participate as an endogenous photosensitizer in UVA carcinogenesis via H(2)O(2) generation, producing metal-mediated mutagenic lesions such as 8-oxodG.


Assuntos
Luz , NAD/química , Fármacos Fotossensibilizantes/farmacologia , 8-Hidroxi-2'-Desoxiguanosina , Animais , Bovinos , Dano ao DNA , Fragmentação do DNA , DNA-Formamidopirimidina Glicosilase/farmacologia , Desoxiguanosina/análogos & derivados , Desoxiguanosina/farmacologia , Genes p53 , Humanos , Peróxido de Hidrogênio/farmacologia , Riboflavina/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta
16.
Photochem Photobiol ; 83(1): 205-12, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16965181

RESUMO

UVA, which accounts for approximately 95% of solar UV radiation, can cause mutations and skin cancer. Based mainly on the results of our study, this paper summarizes the mechanisms of UVA-induced DNA damage in the presence of various photosensitizers, and also proposes a new mechanism for its chemoprevention. UVA radiation induces DNA damage at the 5'-G of 5'-GG-3' sequence in double-stranded DNA through Type I mechanism, which involves electron transfer from guanine to activated photosensitizers. Endogenous sensitizers such as riboflavin and pterin derivatives and an exogenous sensitizer nalidixic acid mediate DNA photodamage via this mechanism. The major Type II mechanism involves the generation of singlet oxygen from photoactivated sensitizers, including hematoporphyrin and a fluoroquinolone antibacterial lomefloxacin, resulting in damage to guanines without preference for consecutive guanines. UVA also produces superoxide anion radical by an electron transfer from photoexcited sensitizers to oxygen (minor Type II mechanism), and DNA damage is induced by reactive species generated through the interaction of hydrogen peroxide with metal ions. The involvement of these mechanisms in UVA carcinogenesis is discussed. In addition, we found that xanthone derivatives inhibited DNA damage caused by photoexcited riboflavin via the quenching of its excited triplet state. It is thus considered that naturally occurring quenchers including xanthone derivatives may act as novel chemopreventive agents against photocarcinogenesis.


Assuntos
Dano ao DNA , Fármacos Fotossensibilizantes/farmacologia , Riboflavina/farmacologia , Neoplasias Cutâneas/etiologia , Raios Ultravioleta/efeitos adversos , Xantonas/farmacologia , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/fisiologia , Dano ao DNA/efeitos da radiação , DNA-Formamidopirimidina Glicosilase/metabolismo , Transporte de Elétrons , Radicais Livres/metabolismo , Guanina/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Metais/metabolismo , Modelos Químicos , Oxigênio/metabolismo , Fármacos Fotossensibilizantes/antagonistas & inibidores , Fármacos Fotossensibilizantes/efeitos da radiação , Riboflavina/antagonistas & inibidores , Riboflavina/efeitos da radiação , Oxigênio Singlete/metabolismo , Neoplasias Cutâneas/patologia , Superóxidos/metabolismo , Xantonas/química
17.
Mutat Res ; 585(1-2): 60-70, 2005 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15923135

RESUMO

Ozone has been shown to induce lung tumors in mice. The reactivity of ozone with DNA in an aqueous solution was investigated by a DNA sequencing technique using 32P-labeled DNA fragments. Ozone induced cleavages in the deoxyribose-phosphate backbone of double-stranded DNA, which were reduced by hydroxyl radical scavengers, suggesting the participation of hydroxyl radicals in the cleavages. The ozone-induced DNA cleavages were enhanced with piperidine treatment, which induces cleavages at sites of base modification, but the inhibitory effect of hydroxyl radical scavengers on the piperidine-induced cleavages was limited. Main piperidine-labile sites were guanine and thymine residues. Cleavages at some guanine and thymine residues after piperidine treatment became more predominant with denatured single-stranded DNA. Exposure of calf thymus DNA to ozone resulted in a dose-dependent increase of the 8-oxo-7,8-dihydro-2'-deoxyguanosine formation, which was partially inhibited by hydroxyl radical scavengers. ESR studies using 5,5-dimethylpyrroline-N-oxide (DMPO) showed that aqueous ozone produced the hydroxyl radical adduct of DMPO. In addition, the fluorescein-dependent chemiluminescence was detected during the decomposition of ozone in a buffer solution and the enhancing effect of D2O was observed, suggesting the formation of singlet oxygen. However, no or little enhancing effect of D2O on the ozone-induced DNA damage was observed. These results suggest that DNA backbone cleavages were caused by ozone via the production of hydroxyl radicals, while DNA base modifications were mainly caused by ozone itself and the participation of hydroxyl radicals and/or singlet oxygen in base modifications is small, if any. A possible link of ozone-induced DNA damage to inflammation-associated carcinogenesis as well as air pollution-related carcinogenesis is discussed.


Assuntos
Dano ao DNA/fisiologia , Ozônio/metabolismo , 8-Hidroxi-2'-Desoxiguanosina , Animais , Catalase/química , Catalase/metabolismo , Bovinos , Cromatografia Líquida de Alta Pressão/métodos , DNA/química , DNA/metabolismo , Dano ao DNA/efeitos dos fármacos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/química , Desoxiguanosina/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/metabolismo , Genes ras , Humanos , Radical Hidroxila/metabolismo , Medições Luminescentes , Ozônio/efeitos adversos , Radioisótopos de Fósforo , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo
18.
Rinsho Shinkeigaku ; 42(2): 175-7, 2002 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-12424972

RESUMO

We reported different clinical phenotypes of siblings with familial amyotrophic lateral sclerosis (FALS) showing Cys146Arg point mutation of superoxide dismutase 1 (SOD1) gene. They showed differences in disease onset of age, progression and severity. The propositus, a 50-year old woman, had muscle wasting and weakness in right lower leg with dysesthesia at the onset, which showed slow progression without other neurological symptoms until 2 years after the onset when bulbar palsy appeared. She has been alive for 3.5 years after the onset. In contrast, a 61-year old man, elder brother of the propositus, had bulbar palsy at the onset, which showed rapid progression along with muscle weakness and wasting of upper extremities. Two years after the onset, he died due to respiratory failure. Detailed clinical features of FALS with Cys146Arg mutation of SOD1 have not been reported. Our cases suggest that FALS with the same SOD1 mutation could show variable clinical feature and course, and that some factors other than SOD1 mutation should be considered for the pathogenesis of FALS.


Assuntos
Esclerose Lateral Amiotrófica/genética , Mutação Puntual , Superóxido Dismutase/genética , Esclerose Lateral Amiotrófica/fisiopatologia , Saúde da Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Superóxido Dismutase-1
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