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Nobuo Sugo

Publications and source records attributed to Nobuo Sugo.

6 recordsLinked to original sources
PubMed2006

Early dynamic 201Tl SPECT in the evaluation of brain tumours.

OBJECTIVE: To estimate the usefulness of early dynamic 201Tl single photon emission computed tomography (SPECT) studies in distinguishing the histological malignancy of brain tumours. METHODS: Dynamic 201Tl SPECT was performed for 3 min per scan for 15 min immediately after the administration of 201TlCl in 110 patients with brain tumours (111 lesions). The data obtained each 3 min were used for dynamic SPECT, and the five sets of data obtained were added to acquire static SPECT data. For static SPECT, the static thallium index (STI) was calculated as the ratio of 201Tl uptake in the tumour to that of the contralateral normal brain. The ratio of the 201Tl uptake for each 3 min was defined as the dynamic thallium index (DTI). The dynamic thallium rate (DTR), as a per cent, was calculated as DTR=(DTI for every 3 min)/STI H 100. The five values were approximated as a linear function and the slope (%/min) was calculated. RESULTS: In static SPECT, there was no significant difference between the STI of malignant tumours (glioblastoma and anaplastic astrocytoma) and that of benign tumours (low-grade glioma, meningioma, pituitary adenoma, neurinoma and haemangioblastoma) (3.7+/-1.5, 5.0+/-3.5, respectively). On dynamic SPECT, DTI increased markedly over 15 min for malignant tumours. In contrast, the DTI of benign tumours increased slightly, steadily or decreased. The slope of the linear functions calculated from the DTRs was much higher in the malignant tumour group than in the benign tumour group (P<0.001). CONCLUSIONS: We suggest that the performance of 201Tl dynamic SPECT for 15 min is useful for distinguishing malignant brain tumours from benign brain tumours and reduces the examination stress of patients.

Adult↗
PubMed2005

Social interaction improves experimental stroke outcome.

BACKGROUND AND PURPOSE: Social interaction can have a profound effect on health. The purpose of the present study was to determine whether affiliative social interactions before and after stroke improve ischemic outcomes as assessed through histological analysis and behavioral assays. METHODS: Male and female C57BL/6 mice were housed individually or with an ovariectomized female. Behavioral assessments were made 24 hours before 60 or 90 minutes of transient intraluminal middle cerebral artery occlusion (MCAO) or SHAM surgery and after 7 days of reperfusion. Two hours after behavioral testing on day 7, infarct size was determined by 2,3,5-triphenyltetrazolium histology, and blood samples were collected for assessment of corticosterone and C-reactive protein (CRP) concentrations. RESULTS: Pair housing significantly decreased infarct size and improved contralateral paw use in 60-minute MCAO males and 90-minute MCAO females compared with socially isolated cohorts. Housing condition had no significant effect on infarct size in females that underwent 60 minutes of MCAO, but pair housing was associated with improved contralateral paw use relative to socially isolated mice. In a separate cohort of males, intraischemic CRP concentration was significantly reduced in pair-housed males relative to isolated males. CONCLUSIONS: Affiliative interaction during the peri-ischemic period reduces intraischemic CRP concentration, decreases ischemic damage in male and female mice, and improves behavioral outcome.

Animals↗
PubMed2002

Poly(ADP-ribose) polymerase impairs early and long-term experimental stroke recovery.

BACKGROUND AND PURPOSE: Poly(ADP-ribose) polymerase (PARP-1; Enzyme Commission 2.4.30) is a nuclear DNA repair enzyme that mediates early neuronal ischemic injury. Using novel 3-dimensional, fast spin-echo-based diffusion-weighted imaging, we compared acute (21 hours) and long-term (3 days) ischemic volume after middle cerebral artery (MCA) occlusion in PARP-1-null mutants (PARP-/-) versus genetically matched wild-type mice (WT mice). PARP-/- mice were also treated with viral transfection of wild-type PARP-1 to determine whether protection from MCA occlusion is lost with restoration of the gene product. METHODS: Halothane-anesthetized mice were treated with reversible MCA occlusion via intraluminal suture technique. Ischemic volumes were delineated by diffusion-weighted imaging with high spatial and temporal resolution during MCA occlusion and reperfusion. Recombinant Sindbis virus carrying beta-galactosidase (lacZ) or PARP-1 was injected into ipsilateral striatum, then animals underwent MCA occlusion 3 days later. Infarction volume was measured at 22 hours of reperfusion (2,3,5-triphenyltetrazolium chloride histology). RESULTS: Reduction in regional water apparent diffusion coefficient (ADC) during occlusion or secondary ADC decline during reperfusion was not different between groups. Ischemic volume was smaller early in occlusion in PARP-/- versus WT mice and remained less at 21 hours of reperfusion. Ischemic volume then increased from 1 to 2 days in all mice, then stabilized without further change. Ischemic damage was smaller in PARP-/- than in WT mice at 3 days. Transfection of PARP-1 into PARP-/- mice increased stroke damage relative to lacZ-injected PARP-/- and increased damage to that of the WT mice. Intraischemic laser-Doppler flowmetry and physiological variables were not different among groups. CONCLUSIONS: PARP-1 deficiency provides both early and prolonged protection from experimental focal stroke. The mechanism is not linked to preservation of ADC and mitigation of secondary energy depletion during early reperfusion.

Animals↗
PubMed2002

Social stress exacerbates focal cerebral ischemia in mice.

BACKGROUND AND PURPOSE: The purpose of the present study was to determine whether exposure to stress or elevated corticosterone concentrations in the days preceding cerebral ischemia exacerbates ischemic injury as assessed by histological and behavioral outcomes. METHODS: For 7 consecutive days, male C57/BL6 mice were exposed to social stress for 45 minutes or injected with 1 mg/kg corticosterone or vehicle. The animals exposed to social stress were injected with either 1 mg/kg mifepristone, a glucocorticoid receptor antagonist, or the vehicle 30 minutes before stress. On the seventh day, all animals were trained in a passive avoidance task. Twenty-four hours after training, the animals were subjected to 60 minutes of intraluminal middle cerebral artery occlusion (MCAO) or sham surgery. At 72 hours of reperfusion, the animals were tested for retention of the passive avoidance task, and infarction size was determined. RESULTS: Animals subjected to chronic social stress or treated with exogenous corticosterone before MCAO exhibited larger infarcts and reduced retention of passive avoidance compared with the nonstressed MCAO control. The effects of social stress on infarct volume and passive avoidance were reversed by pretreatment with mifepristone. There was no difference between stressed and control groups in physiological parameters or reduction of laser-Doppler flow signal during MCAO or reperfusion. CONCLUSIONS: Prior exposure to social stress increases infarction volume and exacerbates cognitive deficits associated with transient cerebral ischemia. The mechanism underlying the effects of stress on stroke outcome likely involves corticosterone acting through glucocorticoid receptors to increase subsequent ischemia-induced neuronal death.

Animals↗
PubMed2002

[Predicting of the period of recurrent for a post-operative glioblastoma after radiochemotherapy using 201TlCl SPECT].

After radiochemotherapy for a post-operative glioblastoma multiforme (GB), the majority of patients return at a later date with a recurrent. To assess whether 201TlCl uptake can be used as a prognostic indicator in patients with GB, we measured the ratio of 201TlCl uptake in tumor to 201TlCl uptake in normal brain (TL index) in 10 patients at the end of radiochemotherapy and followed all the patients until they returned with a recurrent. The TL indices at the end of radiochemotherapy indicated 1.36 to 6.82 (mean +/- SD; 3.59 +/- 1.84), and the terms of tumor recurrent were 3-12 months (5.55 +/- 3.10 month). There was a significant negative correlation between the TL indices and the terms of tumor recurrent (y = -1.28x + 10.14, r = 0.760, p < 0.01). Especially, three cases indicated less than 2.0 did not returned with a recurrent in 8 months and 7 cases more than 2.0 returned with a recurrent in 5 months. This study resulted that 201TlCl SPECT was clinically useful to predict the period of recurrent for GB.

Adult↗