Antiplatelet cilostazol is beneficial in diabetic and/or hypertensive ischemic stroke patients. Subgroup analysis of the cilostazol stroke prevention study.

BACKGROUND AND PURPOSE: Although antiplatelets are known to be effective for secondary prevention of cerebral infarction, the number needed to treat is rather large and the effects in stroke patients with complications such as hypertension or diabetes are inadequately defined. This study was conducted to examine the effect of such complications on recurrence of cerebral infarction, and to assess the effect of cilostazol, an antiplatelet agent, in these high-risk subjects. METHODS: A post hoc subgroup analysis of the already reported Cilostazol Stroke Prevention Study, which was a placebo-controlled double-blind trial, has been carried out to clarify the influence of various complications on recurrence in the placebo group and the effects of cilostazol in 1,095 patients with noncardioembolic ischemic cerebrovascular disease. Treatment continued for an average of 1.8 +/- 1.3 years (maximum 4.8 years). RESULTS: The recurrence rate of the diabetic stroke patients was significantly higher compared with the nondiabetics in the placebo group (9.4 vs. 4.7%/year, p = 0.01). Furthermore, our study showed that the relative risk reduction (RRR) for recurrence of infarction was 41.7% with cilostazol. This treatment provided a significant benefit in patients with lacunar infarction (RRR 43.4%, p = 0.04), with diabetes (RRR 64.4%, p = 0.008), or with hypertension (RRR 58.0%, p = 0.003). CONCLUSIONS: Diabetic patients are particularly at risk for recurrence of cerebral infarction. Cilostazol is useful for the prevention of the recurrence of vascular events in patients with lacunar infarction, and is probably effective in high-risk patients with diabetes and/or hypertension.

Sarpogrelate-Aspirin Comparative Clinical Study for Efficacy and Safety in Secondary Prevention of Cerebral Infarction (S-ACCESS): A randomized, double-blind, aspirin-controlled trial.

BACKGROUND AND PURPOSE: The antiplatelet agent sarpogrelate is a selective inhibitor of 5-hydroxytryptamine receptors. The purpose of this study was to compare the efficacy and safety of sarpogrelate with those of aspirin in Japanese ischemic stroke patients. METHODS: In total, 1510 patients with recent cerebral infarction (1 week to 6 months after onset) were randomly assigned to receive either sarpogrelate (100 mg TID) or aspirin (81 mg/d). Mean follow-up period was 1.59 years. The primary efficacy end point was recurrence of cerebral infarction. Clusters of serious vascular events (stroke, acute coronary syndrome, or vascular event-related death) were selected as secondary end points. The aim of the primary efficacy analysis was to demonstrate the noninferiority of sarpogrelate with respect to aspirin, with the criterion that the upper limit of the 95% CI of the hazard ratio (sarpogrelate vs aspirin) for recurrence of cerebral infarction should not exceed 1.33. RESULTS: Cerebral infarction recurred in 72 patients (6.09%/y) in the sarpogrelate group and in 58 (4.86%/y) in the aspirin group (hazard ratio=1.25; 95% CI, 0.89 to 1.77; P=0.19). A serious vascular event occurred in 90 (7.61%/y) and in 85 (7.12%/y) patients, respectively (hazard ratio=1.07; 95% CI, 0.80 to 1.44; P=0.65). The overall incidences of bleeding events were 89 (11.9%) and 131 (17.3%), respectively (P<0.01). CONCLUSIONS: Sarpogrelate was not noninferior to aspirin for prevention of recurrence of cerebral infarction. Bleeding events were significantly fewer with sarpogrelate than aspirin. The effect of aspirin in Japanese patients was similar to that in Western studies.

A randomized, double-blind study comparing the safety and efficacy of clopidogrel versus ticlopidine in Japanese patients with noncardioembolic cerebral infarction.

BACKGROUND: Patients treated with ticlopidine require careful hematologic monitoring. Clopidogrel may have greater tolerability. However, no direct comparison of these two drugs has been reported and evidence of improved safety with clopidogrel is not yet established in the Japanese population. A comparison of both agents was therefore conducted in Japanese stroke patients. METHODS: Patients with noncardioembolic cerebral infarction were randomized to clopidogrel 75 mg or ticlopidine 200 mg once daily for 52 weeks. The primary endpoint was safety; the major secondary endpoint was the incidence of vascular events. RESULTS: Clopidogrel was associated with significantly fewer safety events than ticlopidine (7.0 versus 15.1%; p < 0.001) and no significant difference in efficacy between the two treatments was seen [hazard ratio 0.977 (95% confidence interval: 0.488-1.957)]. CONCLUSIONS: In Japanese stroke patients, clopidogrel 75 mg is better tolerated than ticlopidine 200 mg once daily.

Effect of the Ca antagonist nilvadipine on stroke occurrence or recurrence and extension of asymptomatic cerebral infarction in hypertensive patients with or without history of stroke (PICA Study). 1. Design and results at enrollment.

BACKGROUND: We examined the effect of a Ca antagonist (nilvadipine) on the occurrence or recurrence of symptomatic stroke in hypertensive patients with MRI-defined asymptomatic cerebral infarction (ACI), periventricular hyperintensity (PVH), and deep and subcortical white matter hyperintensity (DSWMH), with or without a history of stroke, and evaluated the effect of long-term treatment on the lesions. METHODS: Patients with hypertension and incidental ACI were divided into those with (group B, 235 patients) or without (group A, 181 patients) a history of symptomatic stroke, and were given nilvadipine 4-8 mg/day for 3 years. Primary evaluation points were occurrence of symptomatic ischemic stroke and development or extension of asymptomatic ischemic lesions. RESULTS: Male sex, hyperuricemia, diabetes, maximum diameter of infarction and PVH severity were stronger risk factors for group B. Numbers of cerebral infarctions were 31 +/- 28 (group A) and 42 +/- 32 (group B) at enrollment (p < 0.001). Infarctions were larger and located more frequently on the internal capsule, putamen, thalamus and brainstem in group B. The severity of PVH and DSWMH paralleled the number of cerebral infarctions in both groups. CONCLUSION: The study design and status of asymptomatic ischemic brain lesions in hypertensive subjects at enrollment are presented.

Biphasic effects of angiotensin II and receptor antagonism on aggregability and protein kinase C phosphorylation in human platelets.

In order to define the role of angiotensin II (AngII) receptor subtypes, AT1 and AT2, in platelet activation, we examined the effects of AngII and receptor antagonists on both aggregability and phosphorylation status of protein kinase C (PKC) isoforms in human platelets obtained from 56 healthy volunteers. AngII promoted both spontaneous and agonist (collagen and ADP) stimulated platelet aggregation at concentrations of 10 nM or less, but the promotion effects were lost at 100 nM. Antagonism of AT1 receptor inhibited the promotion effects of AngII at 10 nM or less. On the other hand, antagonism of AT2 receptor enhanced platelet aggregability modestly with AngII at 10 nM or less, and markedly with 100 nM AngII. Furthermore, with 10 nM AngII, phospho-PKCalpha/betaII expression in platelets was increased after collagen stimulation and was inhibited by antagonism of AT1 receptor. With 100 nM AngII, expression levels of phospho-PKCalpha/ betaII remained low even after collagen stimulation but were markedly enhanced by antagonism of AT2 receptor. These findings suggest that at 10 nM or below, AngII promotes aggregability and PKC phosphorylation in human platelets through the AT1 receptor, which can be inhibited by AT1 receptor antagonists, but at higher concentrations, the promotion effects were lost through the opposing action of the AT2 receptor. The present study may provide an additional mechanism for AT1 receptor antagonism, which would provide clinical benefit to patients with stroke or cardiovascular disease accompanied by hypertension.

Half pitch lower sound perception caused by carbamazepine.

We report a 16-year-old woman with secondary generalization of partial seizure, who complained of an auditory disturbance after carbamazepine (CBZ) administration. She had been taking sodium valproate (VPA) from the age of 15. However, her seizures remained poorly controlled. We changed her antiepileptic drug from VPA to CBZ. At 1 week after CBZ administration, she noticed that electone musical performances were heard as a semitone lower. When oral administration of CBZ was stopped, her pitch perception returned to normal. If she had not been able to discern absolute pitch, she might have been unable to recognize her lowered pitch perception. Auditory disturbance caused by CBZ is reversible and very rare.

[A case with hepatitis A-associated Guillain-Barre syndrome and elevated serum anti-sulfatide antibody].

A 59-year-old man developed progressive sensory dullness and muscle weakness in the extremities, facial palsy on the left side, and hoarseness 4 days after the onset of acute hepatitis A. Vibration and joint sensation in the extremities were severely affected. Anti-sulfatide IgM antibody level was initially elevated in serum, but diminished along with amelioration of the symptoms following intravenous immunoglobulin therapy. Anti-sulfatide antibody may be involved in the pathogenesis of the present patient with hepatitis A-associated Guillain-Barré syndrome. This is probably the first case of hepatitis A associated Guillain-Barré syndrome with which elevated serum anti-sulfatide antibody was found.

Dendritic cells in hyperplastic thymuses from patients with myasthenia gravis.

To investigate the role of dendritic cells (DCs) in the hyperplastic myasthenia gravis (MG) thymus, we studied the frequency and distribution of three mature DC phenotypes (CD83(+)CD11c(+), CD86(+)CD11c(+), and HLA-DR(+)CD11c(+)) in samples from patients with MG whose symptoms dramatically improved following thymectomy and in non-MG control thymuses. In hyperplastic MG thymuses, mature DCs were much more numerous in nonmedullary areas, such as the subcapsular/outer cortex; around the germinal centers; and in extralobular connective tissue, particularly around blood vessels. Mature DCs strongly coexpressed CD44 and appeared to be components of a CD44-highly positive (CD44(high)) cell population migrating from the vascular system. Furthermore, in the hyperplastic MG thymus, the expression of secondary lymphoid-tissue chemokine (SLC) markedly increased especially around extralobular blood vessels, where the CD44(high) cell population accumulated. These findings suggest that DCs may migrate into the hyperplastic thymus from the vascular system via mechanisms that involve CD44 and SLC. DCs may present self-antigens, thereby promoting the priming and/or boosting of potentially autoreactive T cells against the acetylcholine receptor.

Interleukin-2 production by peripheral blood mononuclear cells from patients with myasthenia gravis.

We examined interleukin-2 (IL-2) production by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMs) from 75 untreated myasthenia gravis (MG) patients and 48 control patients. Patients with MG consisted of those with elevated PBM IL-2 production (>1,250 pg/ml; mean + 2SD of the controls) (n = 29, 39%) and those with normal PBM IL-2 production (<1,250 pg/ml) (n = 46, 61%). Significant characteristics of patients with elevated PBM IL-2 production included elevated serum levels of anti-acetylcholine receptor antibodies, severe generalized symptoms, thymic hyperplasia, and marked effects of thymectomy (p < 0.05). These findings suggest that elevated PBM IL-2 production can reflect functional abnormalities of T cells in some patients with MG, and that PBM IL-2 production should be considered as a candidate target of therapy.

Effects of FK506 on myasthenia gravis patients with high interleukin-2 productivity in peripheral blood mononuclear cells.

We compared the early effects of FK506 on clinical severity, interleukin-2 (IL-2) production by phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMs), and serum levels of acetylcholine receptor antibodies between myasthenia gravis (MG) patients with elevated (>1250 pg/ml, n = 9) or normal (<1250 pg/mL, n = 10) levels of PBM IL-2 production. Reduction in clinical severity and PBM IL-2 production were significantly greater in the patients with elevated IL-2 production than those with normal PBM IL-2 production in the first month of treatment.

Alteration of 8-hydroxyguanosine concentrations in the cerebrospinal fluid and serum from patients with Parkinson's disease.

In order to investigate the possible role of oxidative RNA damage in the pathogenesis of Parkinson's disease (PD), the concentrations of the oxidative stress marker 8-hydroxyguanosine (8-OHG) were measured in the cerebrospinal fluid (CSF) and the serum of patients with PD and control subjects. The concentration of 8-OHG in CSF in PD patients was approximately three-fold that in controls (P < 0.001). The concentration of 8-OHG in CSF decreased significantly with the duration of disease (r(s) = -0.46, P < 0.05). However, the concentration of 8-OHG in serum was not significantly altered in PD patients compared to that in controls. In addition, the concentration of 8-OHG in CSF showed no correlation with that in serum in both the controls and PD patients suggesting that the 8-OHG concentrations in the CSF do not reflect those in serum and may be probably reflect those in brain tissue. These in vivo findings suggest a possible role of 8-OHG and increased oxidative RNA damage in the early stage of the development of PD.

Selective reduction of diffusion anisotropy in white matter of Alzheimer disease brains measured by 3.0 Tesla magnetic resonance imaging.

Alzheimer disease (AD) is pathologically characterized by cortical atrophy. Changes in the white matter and their relation to the pathogenesis of AD remain to be studied. To quantitatively investigate the integrity and organization of white matter fiber tracts in patients with AD, we used diffusion tensor (DT) imaging to study the diffusion anisotropy of white matter regions. DT imaging was performed using a 3.0 Tesla magnetic resonance scanner in ten probable AD patients with no or only mild changes in the white matter in T2 weighted magnetic resonance imagings and ten group-matched controls. The values of fractional anisotropy were significantly lower in the temporal subcortical white matter, posterior part of the corpus callosum, and anterior and posterior cingulate bundles in patients with AD compared with controls. Possible relationships of these selective impairments in the white matter with pathological changes in the posterior cerebral cortices and hippocampus were discussed.

Hypoxic condition interferes with phosphorylation of Akt at Thr(308) in cultured rat pheochromocytoma-12 cells.

Phosphorylation of Akt induced under hypoxic or ischemic conditions has been reported only for residue Ser(473). We examined whether Akt can be phosphorylated at Thr(308), another phosphorylation site on Akt, and can exhibit neuroprotective effects under conditions of hypoxia/reoxygenation, comparing pheochromocytoma-12 (PC12) cells transfected with constitutively active Akt (Myr-pCMV cells) and those transfected with pCMV vector only (pCMV cells). Expression levels of Akt phosphorylated at Ser(473) were 2.1-fold higher in Myr-pCMV cells compared with pCMV cells, before the onset of hypoxia, which were increased transiently during hypoxia, and then decreased gradually during reoxygenation. In contrast, Akt phosphorylated at Thr(308) was not detected in pCMV cells under any conditions but was expressed in Myr-pCMV cells prior to hypoxia, followed by an immediate decrease during hypoxia and a further decline during reoxygenation. However, G1-arrest of the cell cycle observed at 12 h after hypoxia in pCMV cells was prevented in Myr-pCMV cells. These findings suggest that hypoxia activates Akt by phosphorylation at Ser(473) only, which is sufficient to elicit a neuroprotective function against hypoxic neuronal damage.

Over-expression of alpha7 nicotinic acetylcholine receptor induces sustained ERK phosphorylation and N-cadherin expression in PC12 cells.

Over-expression of alpha7 nicotinic acetylcholine receptor (alpha7nAChR) in PC12 cells, independent of agonistic stimulation, induces marked neurite outgrowth and high capacity for migration and adherence (differentiation-like transformation), and increases tolerance against cell damage. In the present study, we investigated the effects of alpha7nAChR over-expression and nicotine on ERK phosphorylation and N-cadherin expression by comparing 3 groups of cells: PC12 cells transfected with alpha7 subunit cDNA (alpha7pCMV cells); untransfected PC12 cells exposed to 50 microM nicotine (PC12 cells+nicotine); and PC12 cells transfected with vector only (pCMV cells). alpha7 subunit protein was detected in alpha7pCMV cells at 24 to 72 h after transfection. alpha7pCMV cells exhibited sustained expression of phospho-ERKs (p42 and p44) at 24 to 72 h after transfection, and differentiation-like transformation at 72 h after transfection. PC12 cells+nicotine exhibited transient expression of phospho-ERKs at 48 h after addition of nicotine, but did not exhibit differentiation-like transformation. Neither ERK phosphorylation nor differentiation-like transformation was observed in pCMV cells. Expression of surface N-cadherin increased at 72 h after transfection on alpha7pCMV cells, but did not increase on PC12 cells+nicotine or pCMV cells. These findings suggest that, in PC12 cells, over-expression of alpha7nAChR induces sustained activation of ERK, which probably promotes N-cadherin expression and differentiation-like transformation.

Remarkable increase in the concentration of 8-hydroxyguanosine in cerebrospinal fluid from patients with Alzheimer's disease.

To investigate the possible role of oxidative RNA damage in the pathogenesis of Alzheimer's disease (AD), the concentrations of the oxidative stress marker 8-hydroxyguanosine (8-OHG) were measured in the cerebrospinal fluid (CSF) and the serum of patients with AD and control subjects. The concentration of 8-OHG in CSF in AD patients was approximately fivefold that in controls (P < 0.001). The concentration of 8-OHG in CSF decreased significantly with the duration of illness (r(s) = -0.48, P < 0.05) and the progression of cognitive dysfunctions (r(s) = 0.67, P < 0.01). However, the concentration of 8-OHG in CSF showed no correlation with that in serum in both the controls and AD patients. In addition, the concentration of 8-OHG in serum was not significantly altered in AD patients compared to that in controls, suggesting that the 8-OHG concentrations in the CSF do not reflect those in serum and may be probably reflect those in brain tissue. These in vivo findings suggest a possible role of 8-OHG and increased oxidative RNA damage in the early stage of the development of AD.

Overexpression of alpha7 nicotinic acetylcholine receptor prevents G1-arrest and DNA fragmentation in PC12 cells after hypoxia.

We investigated the neuroprotective function of alpha7 nicotinic acetylcholine receptor (alpha7nAChR) after transient hypoxia (12 h) and reoxygenation (0-72 h), comparing rat pheochromocytoma (PC12) cells overexpressing FLAG-tagged alpha7nAChR (alpha7pCMV cells) and control PC12 cells (non-transfected or transfected with vector only) in medium with and without nicotine. Plasma membrane degradation in the early phase after hypoxia was inhibited in PC12 cells with nicotine, and more profoundly in alpha7pCMV cells with nicotine. Inhibition of DNA fragmentation in the late phase after hypoxia was most remarkable in alpha7pCMV cells with nicotine, but, surprisingly, it was more remarkable in alpha7pCMV cells without nicotine than in PC12 cells with nicotine. G1-arrest of the cell cycle, observed in control PC12 cells at 12 h after hypoxia, preceding DNA fragmentation, was not evident in alpha7pCMV cells, with or without nicotine. Furthermore, in alpha7pCMV cells with and without nicotine, the basal expression levels of total Akt were approximately 1.5-fold higher, and the up-regulation of Akt phosphorylated at Ser473 after hypoxia was strikingly enhanced, compared with control PC12 cells. These findings suggest that alpha7nAChR functions constitutively in PC12 cells, that its overexpression raises tolerance against G1-arrest and DNA fragmentation after hypoxia, and that it can be considered a candidate target for treatment against hypoxia-induced acute membrane degradation and delayed DNA fragmentation in neurons.