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Sadao Suga

Publications and source records attributed to Sadao Suga.

27 records · Page 2Linked to original sources
PubMed2002

Neuroprotection role of adenosine under hypothermia in the rat global ischemia involves inhibition of not dopamine release but delayed postischemic hypoperfusion.

Adenosine (ADO) has an important role in the ischemic brain as an endogenous neuroprotective factor. On the other hand, intraischemic hypothermia ameliorates ischemic neuronal injury. To investigate the effect of ADO during intraischemic mild hypothermia, the extracellular concentration of ADO, its metabolites, dopamine (DA), and local cerebral blood flow were measured in rat striatum during and after 20 min of global ischemia. Additionally, the histopathological outcome was estimated after 48 h of recirculation. Three experimental groups were used: (1) a normothermic group (NT) maintained at 37 degrees C during and after ischemia; (2) a hypothermic group (HT), exposed to intraischemic hypothermia (32.0 degrees C) and postischemic normothermia; and (3) a hypothermia plus theophylline group (HT+T), with the same temperature conditions as in the HT group, combined with intravenously administration of theophylline (10 mg/kg), an antagonist of adenosine receptor, which was given 10 min before ischemia. The level of ADO in HT was significantly higher than ADO levels in NT. In contrast, ischemic DA release was significantly inhibited in HT compared with NT. Theophylline administration had no effect on intraischemic hypothermia induced modulation of extracellular ADO and DA concentration. The postischemic delayed hypoperfusion was ameliorated in HT, and theophylline eliminated this effect in HT+T. A protective effect on histopathological outcome was observed in HT and HT+T. These results suggest that ADO plays an essential role in the inhibition of postischemic delayed hypoperfusion, but this effect is not crucial role in the protective effect induced by intraischemic hypothermia.

Adenosine↗
PubMed2002

Transient forebrain ischemia induces expression of serine/threonine protein phosphatase 1 mRNA in the vulnerable regions of gerbil brain.

Apoptosis is thought to be implicated in delayed neuronal cell death following transient forebrain ischemia. Recently, apoptosis in neurons induced by an inhibitor of serine/threonine (ser/thr) protein phosphatases (PPs) has been reported. In this study, we investigated the effect of transient forebrain ischemia on the expression of ser/thr PPs in the brain of Mongolian gerbils. At 24 h after 5-min bilateral carotid artery occlusion, Northern blotting analysis revealed the increase of PP1 mRNA expression in the vulnerable CA1 region of the hippocampus and striatum, but not in the cortex and CA3 region. In contrast, the protein level of PP1 detected by Western blotting analysis decreased in all regions. We conclude that the inhibition in PPs expression in the vulnerable regions may affect cell death after transient forebrain ischemia.

Animals↗
PubMed2002

Human herpesvirus 6 viremia in bone marrow transplant recipients: clinical features and risk factors.

Human herpesvirus 6 (HHV-6) infection was studied in 82 bone marrow transplant (BMT) recipients (72 allogeneic, 10 autologous). All recipients and 30 donors were seropositive for HHV-6 antibody at the time of bone marrow transplantation. Thirty-one recipients (37.8%) had HHV-6 viremia 2-4 weeks after transplantation. The incidence of HHV-6 viremia was significantly higher among allogeneic BMT recipients than in autologous BMT recipients (P=.011). Therefore, the following analyses of allogeneic BMT recipients were carried out (n=72). Geometric mean antibody titers (log(10)) were significantly higher in recipients without viremia than in those with viremia (1.84+/-0.39 vs. 1.61+/-0.42; P=.022). Logistic regression analysis demonstrated that leukemia or lymphoma is an independent risk factor (P=.031) for HHV-6 viremia. Rash occurring within 1 month after transplantation was observed in 17 (54.8%) of 31 recipients with HHV-6 viremia but in only 8 (19.5%) of 41 recipients without HHV-6 viremia (P=.001).

Adolescent↗
PubMed2002

Reactivation of human herpesvirus 6 and 7 in pregnant women.

To elucidate the roles of human herpesvirus (HHV)-6 and -7 in pregnant women, peripheral blood samples and genital tract secretions were collected serially from pregnant women, and both serological testing and polymerase chain reaction (PCR) were carried out to detect viral DNA in the secretions. HHV-6 or HHV-7 Immunoglobulin(Ig)M antibodies were not detected in 432 plasma samples collected from pregnant women and cord blood, but IgG antibodies against both viruses were detected in all plasma samples. Significant increases in HHV-6 and HHV-7 IgG antibodies were observed in two (1.6%) and three (2.4%) pregnant women respectively of a total of 123 cases. HHV-6 DNA was detected in the genital tract in three (3.7%) of 82 pregnant women at the first trimester, and in 10 (12.2%) of the same women in the third trimester. The detection rate in the third trimester was significantly higher than that in the first trimester (P = 0.043). Although HHV-7 DNA was detected in the genital tract of two (2.7%) and seven (9.6%) pregnant women of a total of 73 during the first and third trimesters respectively, there was no statistical difference in the detection rate of the viral DNA between the trimesters. Because a significant increase in HHV-6 IgG antibodies was detected in only two pregnant women, it was not possible to carry out statistical analysis to determine the relationship between HHV-6 infection and associated clinical features. Although there was a significant increase in HHV-7 antibody titers in three pregnant women, a positive correlation between the virus infection and the clinical features was not demonstrated. There was no statistical association between virus shedding in the genital tract and the clinical features examined in this study.

Antibodies, Viral↗
PubMed2002

Serological examination of human herpesvirus 6 and 7 in patients with coronary artery disease.

Fifty-three (96%) of 55 patients with coronary artery stenosis were positive for serum anti-HHV-6 IgG, and 50 (91%) of these patients had anti-HHV-7 IgG. The number of cases sero-positive for HHV-6 and -7 in the 54 age matched control volunteers was 52 (96%) and 53 (98%), respectively. No statistical difference in the sero-prevalence of the viruses existed between the patients and the control group. The mean geometric titer (log10) of anti-HHV-6 IgG in both the patients and controls were the same (1.4) (P = 0.845), whereas anti-HHV-7 titers were 1.4 and 1.5, respectively (P = 0.161). Ten (18%) of the 55 patients had anti-HHV-6 IgM; eight (15%) of the 54 control volunteers were also positive (P = 0.636). Three (5%) of the 55 patients had anti-HHV-7 IgM, whereas 3 (6%) of the 54 control volunteers had detectable serum antibody (P = 0.691). Forty-seven of the 55 patients were examined by follow-up angiographic evaluation to clarify the association between viral infection and restenosis following balloon angioplasty. Fifteen of these patients developed restenosis, as determined by angiography. The mean geometric titer (log10) of anti-HHV-6 IgG were 1.3 and 1.4 in patients with restenosis and those without restenosis, respectively (P = 0.724). The mean geometric titer (log10) of anti-HHV-7 IgG in patients with restenosis was not significantly higher (1.5) than in patients without restenosis (1.3) (P = 0.099). Three (20%) of the 15 patients affected by restenosis had anti-HHV-6 IgM; five (16%) of the 32 control patients also had the antibody (P = 0.965). One (7%) of the 15 patients with restenosis and 2 (6%) of the 32 patients without restenosis had anti-HHV-7 IgM (P = 0.558). The present study demonstrates that HHV-6 and -7 reactivation is not associated with the establishment of coronary artery stenosis and restenosis following balloon angioplasty.

Adult↗
PubMed2002

Acute subdural hematoma caused by ruptured cerebral aneurysms: diagnostic and therapeutic pitfalls.

On rare occasions, rupture of a cerebral aneurysm causes acute subdural hematoma (SDH) in addition to subarachnoid hemorrhage (SAH). The frequency of SDH resulting from aneurysmal rupture is summarized, and its clinical and radiological characteristics, as well as potential pitfalls in the diagnosis and the management of this life-threatening condition are described. Among 641 patients with nontraumatic SAH treated between 1992 and 2000, 12 patients (1.9%) presented with SDH due to aneurysmal rupture. The SAH grade on admission was grade II in one patient, grade IV in three patients, and grade V in eight patients. Four underwent both hematoma evacuation and clipping of the aneurysm, four underwent hematoma evacuation alone, and the other four patients were treated conservatively. The outcome was good recovery in two patients, severe disability in one patient, and death in nine patients. Patients with a good outcome had a better SAH grade on admission, smaller midline shift, and smaller SDH volume on the initial CT scan, and they had been treated by both SDH evacuation and clipping of the aneurysm. Emergency one-stage operations may be beneficial for aneurysmal SDH patients who are in good SAH grade, or those who are in poor SAH grade but show some neurological recovery after resuscitation. It should also be mentioned that there are cases of aneurysmal SDH without recognizable SAH on the CT scans, and that a case of aneurysmal SDH may present as a case of 'head trauma' after an accident, because of the disturbance of consciousness resulting from aneurysmal rupture.

Adult↗
PubMed2002

Guillain-Barré syndrome after exanthem subitum.

A female infant developed Guillain-Barré syndrome 20 days after having exanthem subitum confirmed serologically as human herpesvirus 6 infection. DNA of human herpesvirus 6 was detected in peripheral blood mononuclear cells collected on admission.

Exanthema Subitum↗
PubMed2002

Monitoring of active HHV-6 infection in bone marrow transplant recipients by real time PCR; comparison to detection of viral DNA in plasma by qualitative PCR.

Twelve (46%) of the 26 patients had human herpesvirus 6 (HHV-6) viremia after bone marrow transplant (BMT). All isolates were recovered from the samples obtained at 2 weeks after BMT. The sensitivity and the specificity of detection of viral DNA in plasma by qualitative polymerase chain reaction (PCR) for monitoring active virus replication were 92% and 97% respectively. Moreover, the positive (85%) and negative (99%) predictive values were also high. The patients with HHV-6 viremia showed a clear peak in HHV-6 DNA in peripheral blood mononuclear cells (PBMCs) at 2 weeks after BMT, which was measured by real time PCR. The virus DNA level in PBMCs between the two groups (patients with viremia and patients without viremia) was statistically different at 2 weeks after BMT (P = 0.033). In patients with HHV-6 viremia, mean HHV-6 DNA copy number was higher in the samples collected at 2 weeks after BMT than the samples collected at any other time period.

Bone Marrow Transplantation↗