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Biomedical subjects

Sadao Suga

Publications and source records attributed to Sadao Suga.

At least 19 recordsLinked to original sources
PubMed2006

Usefulness of high-b-value diffusion-weighted imaging in acute cerebral infarction.

The aim of our study was to investigate the usefulness of high-b-value diffusion-weighted (DW) MR imaging in patients with acute cerebral infarction. DW images at b-values of 1,000, 2,000, and 3,000 s/mm(2) were performed for 32 patients 48 h after the onset of stroke using a 1.5 T clinical imager. The area of restricted diffusion became more distinct and extensive with increasing b-value in 19 of 32 patients, especially in patients with the atherothrombotic-type cerebral infarction. The visualized extent of infarction was almost the same among the area of restricted diffusion on the b=3,000 ADC map, b=3,000 DWI and final infarction in 12 of 15 patients. High-b-value DWI provided better identification of lesion extension in the cerebral ischemia. It is suggested that the size of the final infarction or irreversible cytotoxic edema is more predictable on high-b-value DWIs than on the usual b=1,000 DWI.

Acute Disease↗
PubMed2006

Intracarotid injection of granulocyte-macrophage colony-stimulating factor induces neuroprotection in a rat transient middle cerebral artery occlusion model.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) was found to promote collateral flow in patients with coronary artery disease and also to induce arteriogenesis in a rat hypoperfusion brain model. Activated macrophages have been shown to induce vascular proliferation and play an important role in ischemic stroke. In this study, we examined the therapeutic effect of GM-CSF on the ischemic brain by activating microglia/macrophages. Rats were subjected to 1-h intraluminal middle cerebral artery occlusion (MCAO) and received an intracarotid injection of GM-CSF (5 ng) or saline immediately after reperfusion. Infarct volume, neurological function and histological findings were assessed 48 h later. An intracarotid injection of GM-CSF reduced the infarct volume and improved neurological function at 48 h after reperfusion. Histological analysis revealed that the number of activated microglia/macrophages to be increased and the number of apoptotic cells to be decreased in the area of the penumbra. These results suggest that intracarotid injection of GM-CSF may have a therapeutic effect on brain ischemia via activation of microglia/macrophages.

Animals↗
PubMed2006

[Exanthem subitum].

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Exanthema Subitum↗
PubMed2005

Predicting the overall management outcome in patients with a subarachnoid hemorrhage accompanied by a massive intracerebral or full-packed intraventricular hemorrhage: a 15-year retrospective study.

BACKGROUND: Patients with a subarachnoid hemorrhage (SAH) accompanied by a massive intracerebral hemorrhage (ICH) or a full-packed intraventricular hemorrhage (IVH) have poor outcomes. We evaluated the clinical factors to predict the overall outcome in such patients. METHODS: Data on nontraumatic SAH patients were collected and classified into 3 groups: the pure SAH group (SAH accompanied with neither ICH nor IVH), the ICH group (SAH accompanied with a massive ICH; hematoma 30 mL), and the IVH group (SAH and all ventricles were full-packed with hematoma). One hundred seventy-nine patients were in the ICH group and 109 in the IVH group. We evaluated clinical factors, such as the Hunt & Hess (H&H) score on admission, age, sex, history, rebleeding ratio, and the computerized tomography findings (SAH score). RESULTS: The result of multivariate logistic regression analysis of clinical variables in the ICH group, good and intermediate H&H grades, younger age (<70), no rebleeding, and lower SAH score were associated with a favorable outcome. In the result of the multivariate logistic regression analysis of clinical variables in the IVH group, only a higher SAH score was associated with an unfavorable outcome. CONCLUSIONS: In the ICH group, factors that could be used to predict a favorable outcome included good and intermediate H&H scores (1, 2, and 3) on admission, younger age (<70), and a lower SAH score. In the IVH group, the main factor that could be used to predict a favorable outcome was a lower SAH score.

Adult↗
PubMed2005

Rapid diagnosis of herpes simplex virus infection by a loop-mediated isothermal amplification method.

Primers for herpes simplex virus type 1 (HSV 1)-specific loop-mediated isothermal amplification (LAMP) method amplified HSV-1 DNA, while HSV-2-specific primers amplified only HSV-2 DNA; no LAMP products were produced by reactions performed with other viral DNAs. The sensitivities of the HSV-1- and HSV-2-specific LAMP methods, determined by agarose gel electrophoresis, reached 500 and 1,000 copies/tube, respectively. The turbidity assay, however, determined the sensitivity of the HSV-1- and HSV-2-specific LAMP methods to be 1,000 and 10,000 copies/tube, respectively. After initial validation studies, 18 swab samples (in sterilized water) collected from patients with either gingivostomatitis or vesicular skin eruptions were examined. HSV-1 LAMP products were detected by agarose gel electrophoresis in the 10 samples that also demonstrated viral DNA detection by real-time PCR. Nine of these 10 samples exhibited HSV-1 LAMP products by turbidity assay. Furthermore, both the agarose gel electrophoresis and the turbidity assay directly detected HSV-1 LAMP products in 9 of the 10 swab samples collected in sterilized water. Next, we examined the reliability of HSV type-specific LAMP for the detection of viral DNA in clinical specimens (culture medium) collected from genital lesions. HSV-2 was isolated from all of the samples and visualized by either agarose gel electrophoresis or turbidity assay.

DNA, Viral↗
PubMed2004

Atypical clinical features of a human herpesvirus-6 infection in a neonate.

A case of neonatal human herpesvirus 6 (HHV-6) B infection is presented. Although HHV-6 B was isolated from peripheral blood at the onset of the illness, a significant increase in viral antibody titers was not observed. The patient had a slight fever with generalized maculopapular skin rash and an increased number of atypical lymphocytes, which is quite different from the typical clinical features of exanthem subitum.

Antibodies, Viral↗
PubMed2004

Rapid diagnosis of human herpesvirus 6 infection by a novel DNA amplification method, loop-mediated isothermal amplification.

A novel nucleic acid amplification method, termed loop-mediated isothermal amplification (LAMP), which amplifies DNA with high specificity, efficiency, and rapidity under isothermal conditions, may be a valuable tool for the rapid detection of infectious agents. LAMP was developed for human herpesvirus 6 (HHV-6), and its reliability was evaluated in this study. Although LAMP products were detected in HHV-6 B and HHV-6 A DNA, they were not detected in HHV-7 and human cytomegalovirus DNA. The sensitivity of the original HHV-6 LAMP protocol was 50 copies/tube. In order to increase the method's sensitivity, HHV-6 LAMP was modified by increasing the primer concentration. As a result of the modification, sensitivity increased to 25 copies/tube. After these initial validation studies, 13 patients with fever were tested for HHV-6 by viral isolation, serological analysis, and HHV-6 LAMP. In three of the eight patients with primary HHV-6 infection, HHV-6 DNA was detected in whole blood by the original HHV-6 LAMP protocol in not only the acute phase but also the convalescent phase. HHV-6 DNA was detected by modified HHV-6 LAMP in all eight plasma samples collected in the acute phase; however, no HHV-6 DNA was detected in plasma samples collected in the convalescent phase. Although HHV-6 DNA was detected in both the acute and convalescent phases of whole-blood samples in patients with past HHV-6 infection, it was not detected in plasma samples that did not contain latent viral DNA. Thus, detection of HHV-6 DNA in plasma by using this modified HHV-6 LAMP protocol is appropriate for diagnosis of active HHV-6 infection.

Base Sequence↗
PubMed2004

Detection of human herpesvirus 7 DNA by loop-mediated isothermal amplification.

The reliability of loop-mediated isothermal amplification (LAMP), initially developed for the detection of human herpesvirus 7 (HHV-7), was evaluated in this study. Although a LAMP product was detected in HHV-7 DNA, neither HHV-6 nor human cytomegalovirus DNA produced a product. When agarose gel electrophoresis was used for the detection of LAMP products, the sensitivity of a 30-min HHV-7 LAMP reaction reached 250 copies/tube. The use of turbidity for the detection of the LAMP products gave a sensitivity of 500 and 250 copies/tube for 30- and 60-min reactions, respectively. Following these initial validation studies, clinical samples collected from two patients with primary HHV-7 infections were examined by HHV-7 LAMP. By use of agarose gel electrophoresis, HHV-7 LAMP products could be detected in acute-phase plasma samples but no LAMP product was detectable in convalescent-phase plasma samples from either patient. Since a turbidity assay is less sensitive than agarose gel electrophoresis, no HHV-7 LAMP product could be detected in plasma samples after a 30-min LAMP reaction. After a 60-min LAMP reaction, HHV-7 LAMP product could be detected in acute-phase plasma samples.

Base Sequence↗
PubMed2003

Variation of human herpesvirus 7 shedding in saliva.

Sequential analysis of human herpesvirus 7 (HHV-7) shedding in saliva obtained from healthy adults was performed for 6 months; virus was isolated in 92 (34.1%) of the 270 saliva samples obtained. Frequency of HHV-7 shedding in serially obtained saliva samples varied among subjects. Associations between frequency of HHV-7 shedding and age, sex, and virus antibody titer were analyzed, and, although sex was not associated with frequency of shedding, young age (P=.031) and low antibody titer (P=.006) were correlated with frequent viral shedding (5 or 6 times/6 months).

Adult↗
PubMed2003

Effect of intra-ischemic hypothermia on the expression of c-Fos and c-Jun, and DNA binding activity of AP-1 after focal cerebral ischemia in rat brain.

It is unknown whether immediate early gene (IEG) induction and subsequent late gene regulation after ischemia is beneficial or deleterious. The aim of this study was to examine the effect of hypothermia on expression of c-Fos and c-Jun, and AP-1 DNA binding activity, after transient focal cerebral ischemia in rat brain, and clarify the role of IEGs and AP-1 after insults. Male Wistar rats underwent right middle cerebral artery occlusion for 1 h with the intraluminal suture method. During ischemia, animals were assigned to either normothermic (NT) or hypothermic (HT) groups. In the NT group, brain temperature was observed to spontaneously increase to 40 degrees C during ischemia. In the HT group, brain temperature decreased to 30 degrees C. Infarct volume in cortex was decreased in the HT group, compared with that in the NT group (P<0.001). Increased c-Fos immunoreactivity in the cortex was observed at 3 h after reperfusion in the HT, but not the NT group, while c-Jun expression was not affected by HT treatment. There was also a significant increase in AP-1 DNA binding activity at 3 h in the HT group when compared to the NT group (P<0.01). In conclusion, hypothermia decreased cerebral infarction in association with early increases in c-Fos expression and AP-1 DNA binding activity in peri-infarct cortex. It remains to be established whether such responses are a cause or consequence of cell survival, but these results clearly establish that altered transcription is a key feature of tissue spared following hypothermic focal ischemia.

Animals↗
PubMed2003

Evaluation of active human herpesvirus 6 infection by reverse transcription-PCR.

Monitoring of active human herpesvirus 6 (HHV-6) infection is important for distinguishing between reactivation and latency of the virus. The reverse transcription polymerase chain reaction (RT-PCR) may be a useful tool in order to distinguish active and latent HHV-6 infection. An RT-PCR assay detecting 4 different HHV-6 gene transcripts was established. Samples of peripheral blood mononuclear cells (PBMCs) were collected from patients with exanthem subitum and used to evaluate the reliability of the assay. After confirming the reliability of the assay, RT-PCR was used to determine whether HHV-6 reactivation occurs in children with hypercytokinemia. Three gene transcripts (U31, U39, and U94) were detected in 90-100% of the PBMC samples collected from febrile period of exanthem subitum patients, from which HHV-6 was isolated. The two gene transcripts encoding the late proteins U31 and U39, however, were not detected in samples collected during the convalescent period that contained no infectious virus. The putative latency associated gene transcript, U94, was detected in 2 (10%) of the 20 convalescent samples, and another immediate early gene transcript, U90, was also detected in 3 (15%) of the 20 convalescent samples. The frequency of HHV-6 reactivation in patients with hypercytokinemia, suggesting monocyte/macrophage activation, was studied. Only 9 of 17 patients diagnosed with Kawasaki disease and 1 patient diagnosed with juvenile rheumatoid arthritis were positive for HHV-6 DNA in their PBMCs samples. Neither the U31 gene nor the U94 gene transcript was detected in any of the 10 samples. An RT-PCR assay screening for both immediate early and late genes may be useful for monitoring active HHV-6 infection. No HHV-6 reactivation was found in patients with hypercytokinemia using the RT-PCR assay.

Cytokines↗
PubMed2003

Spread of varicella-zoster virus DNA to the environment from varicella patients who were treated with oral acyclovir.

OBJECTIVE: The purpose of the present study was to determine the degree of spread of varicella-zoster virus to the environment (VZV) from varicella patients who received oral acyclovir treatment. METHODS: Over a period of 8 months, seven healthy children (two girls and five boys, 23-64 months of age) with varicella who visited Fujita Health University School of Medicine were treated with routine doses of oral acyclovir (ACV) for 5 days, commencing within 24 h after onset of the disease. Swab samples from the throats of patients and their family members as well as from air purifier filters in their houses were collected for 7 days as frequently as possible after starting treatment for the disease. The VZV DNA in the samples was identified by a sensitive polymerase chain reaction amplification assay. RESULTS: The VZV DNA was detected in 33-100% of throat swab samples from varicella patients by day 7 of the disease, in 17-32% of throat swab samples from family members by day 4 and in 29% of filters from air purifiers by day 3. CONCLUSIONS: The results suggest a broad spread of VZV, probably by the airborne route, from the patients with varicella even after the administration of oral ACV.

Acyclovir↗
PubMed2003

Postischemic hypothermia inhibits the generation of hydroxyl radical following transient forebrain ischemia in rats.

A small reduction of body temperature during reperfusion following cerebral ischemia has been known to ameliorate neuronal injury. However, the mechanisms underlying postischemic hypothermia-induced neuroprotection are poorly understood. The burst of reactive oxygen species (ROS) formation that occurs during reperfusion has been documented to be involved in ischemic neuronal degeneration. In this study, we investigated the effect of postischemic hypothermia on ROS production following transient forebrain ischemia using an in vivo microdialysis technique. Forebrain ischemia was induced by bilateral carotid artery occlusion combined with hemorrhagic hypotension for 20 min in male Wistar rats. The body temperature was kept at 37 degrees C during ischemia and controlled at either 32 degrees C or 37 degrees C after reperfusion. The amount of hydroxyl radical produced in striatum was evaluated by measurement of 2,3- and 2,5-dihydroxybenzoic acid (DHBA), which is generated by salicylate hydroxylation. We also measured the extracellular concentration of xanthine, while determining striatal blood flow by the hydrogen clearance technique. In animals whose postischemic body temperature was maintained at 37 degrees C, the levels of 2,3- and 2,5-DHBA significantly increased after reperfusion. The peak levels of 2,3- and 2,5- DHBA were 2.9-fold and 2.7-fold increased above the corresponding baseline values, respectively. Postischemic hypothermia completely inhibited the hydroxyl radical formation. Likewise, xanthine formation was also inhibited by postischemic hypothermia. In contrast, striatal cerebral blood flow was not altered by temperature modulation during reperfusion. These results suggest that inhibition of ROS production accompanied with suppression of xanthine formation is implicated in the neuroprotection of postischemic hypothermia.

Animals↗
PubMed2003

A juvenile case of cerebellar arteriovenous malformation (AVM) with gradual onset of headache and ataxia.

An 11-year-old male was admitted because of frequent vomiting and truncal ataxia which had lasted for over one week. He had clear consciousness but slowly-progressive mild headache and ataxic gait. Cranial CT revealed a 4 cm hematoma in the right cerebellar hemisphere. Angiography showed a 2 x 2 cm nidus of a pial arteriovenous malformation (AVM) in the right hemisphere fed from the right posterior inferior cerebellar artery and draining into the inferior hemispheric vein. We performed a surgical resection of the AVM after decompression therapy to counteract the brain edema. He recovered completely without any neurological deficits. This case suggests that cerebellar hemorrhage caused by AVM should be considered as a possible diagnosis when mild symptoms of headache and ataxia proceed gradually.

Cerebellar Diseases↗