Background and purposeInvestigation of the relationship between mitochondrial DNA (mtDNA) variants and Parkinson disease (PD) remains an issue awaiting more supportive evidence. Moreover, an affirming cellular model study is also lacking.MethodsThe index mtDNA variants and their defining mitochondrial haplogroup were determined in 725 PD patients and 744 non-PD controls. Full-length mtDNA sequences were also conducted in 110 cases harboring various haplogroups. Cybrid cellular models, composed by fusion of mitochondria-depleted rho-zero cells and donor mitochondria, were used for a rotenone-induced PD simulation study.ResultsMultivariate logistic regression analysis revealed that subjects harboring the mitochondrial haplogroup B5 have resistance against PD (odds ratio 0.50, 95% confidence interval 0.32-0.78; P = 0.002). Furthermore, a composite mtDNA variant group consisting of A10398G and G8584A at the coding region was found to have resistance against PD (odds ratio 0.50, 95% confidence interval 0.33-0.78; P = 0.001). In cellular studies, B4 and B5 cybrids were selected according to their higher resistance to rotenone, in comparison with cybrids harboring other haplogroups. The B5 cybrid, containing G8584A/A10398G variants, showed more resistance to rotenone than the B4 cybrid not harboring these variants. This is supported by findings of low reactive oxygen species generation and a low apoptosis rate in the B5 cybrid, whereas a higher expression of autophagy was observed in the B4 cybrid particularly under medium dosage and longer treatment time with rotenone.ConclusionsOur studies, offering positive results from clinical investigations and cybrid experiments, provide data supporting the role of variant mtDNA in the risk of PD.
The role of high mobility group box 1 (HMGB1) has been demonstrated in stroke and coronary artery disease but not in peripheral arterial occlusive disease (PAOD). The pathogenesis of HMGB1 in acute and chronic vascular injury is also not well understood. We hypothesized that HMGB1 induces inflammatory markers in diabetic PAOD patients. We studied 36 diabetic patients, including 29 patients with PAOD, who had undergone amputation for diabetic foot and 7 nondiabetic patients who had undergone amputation after traumatic injury. Expression of HMGB1 and inflammatory markers were quantified using immunohistochemical staining. Mitochondrial DNA copy number was quantified using real-time polymerase chain reaction. Compared with that in the traumatic amputation group, HMGB1 expression in vessels was significantly higher in the diabetes and diabetic PAOD groups. In all subjects, arterial stenosis grade was positively correlated with the expression levels of HMGB1, 8-hydroxyguanosine, malondialdehyde, vascular cell adhesion molecule 1, and inflammatory markers CD3, and CD68 in both the intima and the media of vessels. Furthermore, HMGB1 expression level was positively correlated with 8-hydroxyguanosine, vascular cell adhesion molecule 1, nuclear factor-kB, CD3, and CD68 expression. Within the PAOD subgroup, subjects with HMGB1 expression had higher expression of the autophagy marker LC3A/B and higher mitochondrial DNA copy number. HMGB1 may be an inflammatory mediator with roles in oxidative damage and proinflammatory and inflammatory processes in diabetic atherogenesis. Moreover, it may have dual effects by compensating for increased mitochondrial DNA copy number and increased autophagy marker expression.
Hyperglycemia-induced reactive oxygen species production can cause diabetes and its complications, including atherosclerosis. The role of mitochondrial DNA variants and mitochondrial copy number in the pathogenesis of diabetic atherogenesis is not well understood. We examined 36 diabetic patients who had undergone amputation for diabetic foot and seven non-diabetic patients who had undergone amputation after traumatic injury. Mitochondrial DNA was extracted and used for sequencing. Single nucleotide polymorphisms (SNPs) relative to the Cambridge reference sequence were analyzed. Mitochondrial DNA copy number was quantified by real-time PCR. Twenty-one novel variants were detected in 29 diabetic patients with arterial stenosis; six of the variants were heteroplasmic, and most occurred in highly evolutionarily conserved residues. These variants were more prevalent in patients with arterial stenosis than in those without stenosis. The novel variants included four in complex I (ND1: C3477A/C, A3523A/G; ND5: C13028A/C, C13060A/C), one in complex IV (COX1: T6090A/T), and one in rRNA (12srRNA: G857G/T). Compared with non-diabetic patients, the diabetic patients had significantly less mitochondrial DNA. Furthermore, among diabetic patients with arterial stenosis, there was a significant positive correlation between mitochondrial DNA copy number and the number of total SNPs. In conclusion, we identified six novel heteroplasmic mitochondrial DNA variants among diabetic patients with arterial stenosis, and we found that diabetic atherogenesis is associated with decreased amounts of mitochondrial DNA.
BACKGROUND:A T-to-C transition at mitochondrial DNA (mtDNA) nucleotide position 16189 can generate a variable length polycytosine tract (poly-C). This tract variance has been associated with disease. A suggested pathogenesis is that it interferes with the replication process of mtDNA, which in turn decreases the mtDNA copy number and generates disease.METHODS:In this study, 837 healthy adults' blood samples were collected and determined for their mtDNA D-loop sequence. The mtDNA copy number in the leucocytes and serum levels of oxidative thiobarbituric acid reactive substance (TBARS) and antioxidative thiols were measured. All subjects were then categorised into three groups: wild type or variant mtDNA with presence of an interrupted/uninterrupted poly-C at 16180-16195 segment.RESULTS:A step-wise multiple linear regression analysis identified factors affecting expression of mtDNA copy number including TBARS, thiols, age, body mass index and the mtDNA poly-C variant. Subjects harbouring a variant uninterrupted poly-C showed lowest mean (SD) mtDNA copy number (330 (178)), whereas an increased copy number was noted in subjects harbouring variant, interrupted poly-C (420 (273)) in comparison with wild type (358 (215)). The difference between the three groups and between the uninterrupted poly-C and the composite data from the interrupted poly-C and wild type remained consistent after adjustment for TBARS, thiols, age and body mass index (p=0.001 and p=0.011, respectively). A trend for decreased mtDNA copy number in association with increased number of continuous cytosine within the 16180-16195 segment was noted (p(trend)<0.006).CONCLUSIONS:Our results substantiate a previous suggestion that the mtDNA 16189 variant can cause alteration of mtDNA copy number in human blood cells.
AIM: To investigate the gender differences associated with a thinner intima-media thickness (IMT) of the common carotid artery (CCA) in women.MATERIALS AND METHODS: In a sample of 218 consecutive healthy volunteers comprising 110 men and 108 women, the IMT of the CCA was measured using B-mode ultrasonography. Blood pressure, fasting blood sugar, body mass index (BMI), blood lipid profile, homocysteine, folic acid, uric acid, high sensitive C-reactive protein, and thiobarbituric acid reactive substances (TBARS) levels were measured and compared with each other in both genders.RESULTS: The IMT of the CCA was significantly thinner in women than in men (p = 0.012). Blood pressure, fasting plasma glucose, BMI, tow-density lipoprotein cholesterol, triglycerides, homocysteine, uric acid, and TBARS were significantly (p < 0.05) tower, folic acid and high-density lipoprotein cholesterol (HDL-C) were significantly (p < 0.0001) higher in women compared with men. Multivariable logistic regression analysis revealed that higher serum levels of homocysteine, uric acid, and TBARS, and tower serum levels of HDL-C were significantly (p < 0.05) associated with mate sex. Multiple linear regression analysis further revealed that age, sex, and BMI were independently associated with CCA IMT.CONCLUSIONS: The IMT of the CCA was thinner in women than in men. Traditional vascular risk factors explain only a small amount of variance in multivariate regression models supporting the hypothesis that other behavioural, sex hormone-related or genetic factors, which have not been sufficiently explored so far, may play a rote in the gender differences of IMT. (C) 2009 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
BACKGROUND AND PURPOSE:Although a clear protocol for reduction of recurrent ischaemic stroke (RIS) has been established, few studies have compared the stroke subtype distribution and risk factors between RIS and first-ever stroke (FES). METHODS:This one-year hospital-based study enrolled 587 FES and 475 RIS patients. Patients were categorized into four stroke subtypes according to a modified TOAST stroke subtype classification system. Risk factor profiles were compared between the two major stroke groups and between the corresponding four subtypes to discriminate the significant risk factors for RIS. RESULTS:A multivariate regression analysis identified hypertension (OR, 1.87; 95% CI, 1.34-2.62), diabetes mellitus (DM) (OR, 1.57; 95% CI, 1.22-2.02), low high-density lipoprotein (LHDL) (OR, 1.43; 95% CI, 1.08-1.88) and older age as significant RIS risk factors. The significance of the former three RIS factors was further recognized in its large-vessel subtype. Moreover, metabolic syndrome was significantly more common in the recurrent stroke group (P = 0.01), including its large-vessel subtype (P = 0.04). Progressively increasing odds ratios from 1.49 to 2.02, in accordance with increased number of diagnostic components of metabolic syndrome for recurrent large-vessel ischaemic stroke, were noted. CONCLUSIONS:Metabolic syndrome likely plays a crucial role in the development of RIS, including large-vessel infarction in modern-day Taiwan.
Status epilepticus results in preferential neuronal cell loss in the hippocampus. We evaluated the hypothesis that the repertoire of intracellular events in the vulnerable hippocampal CA3 subfield after induction of experimental temporal lobe status epilepticus entails upregulation of nitric oxide synthase II (NOS II), followed by the release of mitochondrial cytochrome c that triggers the cytosolic caspase-3 cascade, leading to apoptotic cell death. In Sprague-Dawley rats, significant and temporally correlated upregulation of NOS II (3-24 h), but not NOS I or II expression, enhanced cytosolic translocation of cytochrome c (days 1 and 3), augmented activated caspase-3 in cytosol (days 1, 3 and 7) and DNA fragmentation (days 1, 3 and 7) was detected bilaterally in the hippocarripal CA3 subfield after elicitation of sustained seizure activity by microinjection of kainic acid into the unilweral CA3 sublield. Application bilaterally into the hippocampal CA3 subfield of a selective NOS II inhibitor, S-methylisothiourea, significantly blunted these apoptotic events; a selective NOS I inhibitor, N-omega-propyl-L-arginine or a potent NOS III inhibitor, N-5-(1-iminoethyl)-L-ornithine was ineffective. We conclude that upregulation of NOS II contributes to apoptotic cell death in the hippocampal CA3 subfield via a cytochrome c/caspase-3 signaling cascade following the induction of experimental temporal lobe status epilepticus. (c) 2007 Elsevier Ltd. All rights reserved.
We evaluated 22 patients with epileptic seizures in which the seizures were triggered by various games or game-related materials. Based on whether spontaneous seizure coexisted or not, these 22 patients were divided into two groups. Ten patients who experienced seizures exclusively while playing or watching specific games were referred to as Group I, while 12 patients that had both game-induced and spontaneous seizures were classified as Group II. The patients in Group I had a middle-age onset (39.1 years) with a male predominance (90%). The electroencephalogram (EEG) or brain magnetic resonance imaging revealed non-specific abnormalities in 60%, and the partial onset seizure was recognized in 30% of patients. Antiepileptic drugs had uncertain benefits in this group. In Group II, patients had a male predominance (67%), with onset during adolescence (16.3 years). Most of them had generalized tonic-clonic seizures, myoclonic seizures, and absences, and 42% showed epileptiform discharge on EEG. These 12 patients were categorized into idiopathic generalized epilepsies. Although photosensitivity was an important factor, higher mental activity seemed to be significant precipitants of seizures in Group II. Antiepileptic drugs were necessary and valproic acid alone or combined with clonazepam was effective in this group. The results showed that game-related seizures are not a unique and homogeneous syndrome and may consist of different mechanisms. Teenage onset, coexistent spontaneous seizure, and associated idiopathic generalized epilepsies were crucial factors in the determination of antiepileptic drug therapy. Moreover, avoiding the related games altogether may be a more productive preventive measure.
To analyze the prognostic factors and therapeutic outcome of adult patients with isolated symptomatic stenosis of the middle cerebral artery (MCA). Forty-nine patients were retrospectively verified with isolated symptomatic stenosis of the MCA through both magnetic resonance angiogram and transcranial color-coded duplex sonography. Therapeutic outcome at 1 year or more was determined using a modified Barthel index (BI). For the purpose of analysis, the patients were divided into two groups: a good outcome group (BI > or = 12) and a poor outcome group (BI < 12 or recurrent stroke). The association between different therapeutic regimens and the percent free of recurrent stroke after the first event of cerebral infarction was assessed with Kaplan-Meier plots compared by a log-rank test. These patients accounted for 2.8% of all patients with the first event of cerebral infarction during the same period. At follow-up of 1 year or more, 63% had good outcomes whilst the other 37% had poor outcomes. Overall, 26.5% suffered from recurrent strokes during the follow-up period. According to the statistical analysis, the stepwise logistic regression revealed that only the National Institutes of Health Stroke Scale (NIHSS) at the time of admission was independently associated with a poor outcome. Furthermore, Kaplan-Meier analysis showed a significantly higher percentage of patients free of recurrent stroke events amongst those who were treated with warfarin. The NIHSS at the time of admission was a predictor of outcome amongst our patients, and stenosis of the MCA implies the danger of recurrent cerebral events. Our study also demonstrates the efficacy of oral anticoagulants in the secondary prevention in this specific group of patients. Therefore, we look forward to more prospective multicenter investigations in evaluating the efficiency of therapy in the future.
Objective: A common variant in mitochondrial DNA ( mtDNA) at bp 16189 ( T -> C transition) has been associated with small birth size, adulthood hyperglycemia, and insulin resistance in Caucasians. In this study, we investigated whether mtDNA 16189 variant is associated with metabolic syndrome in Chinese subjects.Methods: Six hundred fifteen Chinese adults, aged 40 yr or older, were recruited in this study. The 16189 variant of mtDNA was detected using PCR and restriction enzyme digestion. Metabolic syndrome was diagnosed on modified National Cholesterol Education Program Adult Treatment Panel III guidelines, using body mass index ( BMI) instead of waist circumference. An association study was performed with x(2) test and logistic regression analysis.Results: The prevalence of the 16189 variant was higher in patients with metabolic syndrome than in those without: 44% ( 125 of 284) vs. 33.2% ( 110 of 331) ( P = 0.006). The association between this 16189 variant of mtDNA and metabolic syndrome ( P = 0.021) remained significant even after correcting for age and BMI. As to the individual traits, the prevalence of fasting plasma glucose of at least 110 mg/ dl ( >= 6.1 mmol/ liter) [( 51.5% ( 121 of 235) vs. 42.1% ( 160 of 380); P = 0.023], type 2 diabetes mellitus [ 48.1% ( 113 of 235) vs. 39.2% ( 149 of 380); P = 0.031], and hypertriglyceridemia [ 44.3% ( 104 of 235) vs. 35.8% ( 136 of 380); P = 0.037] were significantly higher in subjects harboring the 16189 variant of mtDNA than those with the wild type. However, the prevalence of hypertension [ 53.2% ( 125 of 235) vs. 47.6% ( 181 of 380); P = 0.180], BMI greater than 25 kg/ m(2) [ 48.5% ( 114 of 235) vs. 43.9% ( 167 of 380); P = 0.270], and low high- density lipoprotein cholesterol [ 61.3% ( 144 of 235) vs. 54.7% ( 208 of 380); P = 0.111] did not reach a significant difference between the two groups. Furthermore, there was a trend of increasing frequency of occurrence of the 16189 variant in individuals having an increasing number of components of metabolic syndrome ( P(trend) < 0.005).Conclusion: Our data strongly suggest that mtDNA 16189 variant underlies susceptibility to metabolic syndrome in the Chinese population.
Abstract: A transition of T to C at nucleotide position 16189 in mitochondrial DNA (mtDNA) has attracted biomedical researchers for its probable correlation with the development of diabetes mellitus in adult life. In diabetes, persistent hyperglycemia may cause high production of free radicals. Reactive oxygen species are thought to play a role in a variety of physiologic and pathophysiologic processes in which increased oxidative stress may play an important role in disease mechanisms. The aim of the present study was to clarify the degree of oxidative damage and plasma antioxidant status in diabetic patients and to see the potential influence of the 16189 variant of mtDNA on the oxidative status in these patients. An indicative parameter of lipid peroxidation, malondialdehyde (MDA), and total free thiols were measured from plasma samples of 165 type 2 diabetic patients with or without this variant and 168 normal subjects. Here we report an increase in the plasma levels of MDA and total thiols in type 2 diabetic patients compared with control subjects. The levels of plasma thiols in diabetic patients with the 16189 variant of mtDNA were not different from those in controls. These results suggest an increase in the oxidative damage and a compensatory higher antioxidative status in patients with type 2 diabetes. Harboring the 16189 mtDNA variant may impair the ability of a cell to respond properly to oxidative stress and oxidative damage.
We present five patients of epilepsy in which seizures were triggered by playing or watching the traditional Chinese gambling game “Mah-Jong.” One patient also experienced seizures while playing a computer version of the Mah-Jong game. This condition appeared to have a predominance of males (80%) and middle-aged onset (39.4 years). Four patients had generalized tonic-clonic seizures and one patient had partial seizures with secondary generalization. No spontaneous seizure occurred in these patients. Three patients had been receiving antiepileptic drug therapy, but without effective control over their seizures. Mah-Jong-induced epilepsy is a very peculiar form of complex reflex epilepsy that involves the higher mental activities. This phenomenon may consist of distinct pathophysiologic mechanisms from other reflex epilepsy induced by thinking and spatial tasks in idiopathic generalized epilepsies. This unusual reflex epilepsy is relatively benign in nature and antiepileptic drug therapy has uncertain benefits. It may be necessary to avoid playing the Mah-Jong game in order to prevent seizures.
A number of previous studies indicated that ischemia–reperfusion injury causes two distinct types of cell death—necrosis and apoptosis—in the central nervous system. It was also implicated that the intensity of injury can somehow affect the cell death mechanisms. By occluding the descending thoracic aorta with or without simultaneously induced hypovolemic hypotension in rats, we established a model of experimental spinal cord ischemia–reperfusion (I/R) in which the injury severity can be controlled. Recordings of carotid blood pressure (CBP) and spinal cord blood flow (SCBF) showed that aortic occlusion induced dramatic CBP elevation but SCBF drop in both the normotensive (NT) and hypotensive (HT) groups of rats. However, the HT group demonstrated significantly lower SCBF during aortic occlusion, and much slower elevation of SCBF after reperfusion, and extremely poor neurological performance. Spinal cord lesions were characterized by infarction associated with extensive necrotic cell death, but little apoptosis and caspase-3 activity. In contrast, in the NT group, I/R injury resulted in minor tissue destruction associated with persistent abundant apoptosis, augmented caspase-3 activity, and favorable functional outcome. The relative sparing of motoneurons in the ventral horns from apoptosis might have accounted for the minor functional impairment in the NT group. The severity of I/R injury was found to have substantial impact on the histopathological changes and cell death mechanisms, which correlate with neurological performance. Our results implicate that injury severity and duration after injury are two critical factors to be considered in therapeutic intervention.
Intracranial tuberculoma is typically located in the parenchyma. Lesions limited to the ventricular system are uncommon. It is difficult to make a differential diagnosis from other lesions if no systemic tuberculosis is present.This study investigates a case of solitary intraventricular tuberculoma in a 19-year-old female patient with an initial clinical symptom of progressive headache. Cranial computed tomography revealed a strongly enhanced lesion in the lateral ventricle. Histopathology of the tumor demonstrated chronic inflammation, caseous necrosis, epithelioid cells and Langhans' giant cell. The culture study grew M. Tuberculosis.Solitary intraventricular tuberculoma in adults is extremely rare. Medical treatment is the preferred management method of this disease, and surgical intervention should be considered in certain situations.
We report a 41-year-old woman with complex reflex epilepsy in which seizures were induced exclusively by the act of tooth brushing. All the attacks occurred with a specific sensation of sexual arousal and orgasm-like euphoria that were followed by a period of impairment of consciousness. Ictal EEG demonstrated two events of epileptic seizure that were provoked after tooth brushing for 38 and 14 seconds, respectively. The interictal EEG showed epileptiform discharges over the right anterior temporal region and interictal single photon emission computed tomography (SPECT) scan showed relative hypoperfusion in the uncus of right temporal lobe. Brain magnetic resonance imaging (MRI) revealed right hippocampal atrophy. We suggest that tooth-brushing epilepsy, especially with sexual ictal manifestations, may provide insight into the cerebral pathophysiology at the right temporolimbic structure.
A case of intracranial hypotension with spontaneous cerebrospinal fluid (CSF) leak was reported. A Tc-99m diethyltriaminepentacetic acid radionuclide cisternography (RNC) showed the accumulation of radioactivity in the area of the subarachnoid space, the poor migration of the isotope over the convexities, and the early appearance of kidney and bladder activity. To localize the site of CSF leak, RNC will be the choice, and when the time comes, RNC will work well in the location of the leak.