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Biomedical subjects

K Fukui

Publications and source records attributed to K Fukui.

At least 55 records · Page 3Linked to original sources
PubMed2001

Relationship between regional cerebral blood flow and verbal fluency in Alzheimer's disease.

Category and letter verbal fluency tests are widely used for dementia detection and severity measure. Performances of these tasks have been regarded to be mainly associated with the left frontal lobe function. However, some recent studies suggest that there are different neuropsychological bases between these two tasks, and the brain region which contributes to these performances still remains unclear in Alzheimer's disease (AD). To clarify the neural basis of verbal fluency in AD, we examined the relationship between performances of these tasks and regional cerebral blood flow (rCBF). Twenty-five AD patients were administered verbal fluency tasks and single photon emission computed tomography (SPECT) scans. Thirteen cortical regions of interest were symmetrically defined in each hemisphere. Letter fluency scores were correlated significantly only with the left prefrontal (Brodmann's area (BA) 10-46) regional cerebral blood flow (rCBF). In contrast, category fluency scores were correlated most strongly with the left temporal rCBF and also with the left prefrontal (BA 10-46) rCBF. In conclusion, the present study suggests that left prefrontal (BA 10-46) dysfunction contributes to decline in both letter and category fluency scores in AD, while typical posterior dysfunction of AD has a closer relationship with decline in category fluency scores.

Aged↗
PubMed2001

Qualitative analyses of clock drawings in Alzheimer's disease and vascular dementia.

Although quantitative analyses of clock drawings (CD) have achieved widespread clinical use as a cognitive screening, little is known about the qualitative profiles of CD in Alzheimer's disease (AD) and vascular dementia (VD). To address this issue, the present study examined the significance of qualitative analyses of CD in AD and VD. Sixty-seven AD patients, 44 VD patients and eight controls underwent a clock drawing test and took the Mini-Mental State Examinations (MMSE). In the dementia groups, quantitative scores significantly decreased compared with controls and were significantly correlated with MMSE scores. Qualitative analysis demonstrated that in AD patients qualitative error patterns were stable and independent of severity. In contrast, in VD patients the frequency of graphic difficulties and conceptual deficit increased, while the frequency of spatial and/or planning deficit decreased, as severity worsened. In mild dementia groups the frequency of spatial and/or planning deficit was significantly higher in VD. In moderate dementia groups, the frequency of graphic difficulties was significantly higher in VD and the difference in the frequency of spatial and/or planning deficit seen in mild dementia disappeared. The present study suggests that qualitative analyses of clock drawings could demonstrate the neuropsychological profiles of AD and VD and their differences between these dementias.

Aged↗
PubMed2001

Corpora amylacea replace the hippocampal pyramidal cell layer in a patient with temporal lobe epilepsy.

A 39-year-old woman, with a 23-year history of medically intractable seizures of the complex partial type, underwent a left anterior temporal lobectomy and hippocampectomy. Histologic examinations revealed a massive occurrence of corpora amylacea, neuronal loss, and gliosis in the pyramidal cell layer of the hippocampus. The distribution of corpora amylacea in this case was quite distinctive and unlike the patterns of "nonspecific" corpora amylacea formation seen in aging or other neurodegenerative conditions. The pathogenetic aspects of the accumulation of these peculiar bodies are discussed in relation to hippocampal sclerosis.

Adult↗
PubMed2001

Effects of sevoflurane and isoflurane on electrocorticographic activities in patients with temporal lobe epilepsy.

To compare the neuroexcitatory effects of sevoflurane and isoflurane, we recorded electrocorticograms (ECoG) during wakefulness and during sevoflurane and isoflurane anesthesia in six patients with temporal lobe epilepsy (TLE). These patients had subdural grid electrodes chronically implanted in the temporal region. During sevoflurane anesthesia at 1.5 minimum alveolar concentration (MAC) of the combination with 67% nitrous oxide (N2O), a marked increase in interictal paroxysmal activities was observed in four patients. Two patients had a slight increase in paroxysmal activities. Activated areas were widely distributed, not being confined to the ictal onset zone of spontaneous seizures. However, isoflurane anesthesia at 1.5 MAC of the combination with 67% N2O was associated with less increased paroxysmal activity. While the neuroexcitatory properties of sevoflurane proved greater than those of isoflurane, the widespread irritative response to sevoflurane administration was not helpful in localizing the epileptogenic area.

Adolescent↗
PubMed2001

Pretreatment with a deleted form of hepatocyte growth factor (dHGF) prevents the mortality of plasma-loss-induced hypovolemic shock in rats.

Severe trauma, infection, burn, pancreatitis and major surgery often induce circulatory collapse leading to multiple organ failure and death. It is hypothesized that therapy for the attenuation of circulatory collapse may improve the prognosis in these diseases. Previous work has documented that pretreatment with a deleted form of hepatocyte growth factor (dHGF) in normal rats increases the circulating plasma volume that reflects its accelerating action of hepatic protein synthesis. Therefore, the effects of pretreatment with dHGF on hypovolemic shock models were studied in rats. Rats were intravenously administered dHGF (1 mg/kg, twice daily for 5-6 days) or vehicle, and subjected to a 25% total body surface area full-thickness burn or a trypsin-induced acute pancreatitis. In rats that were receiving vehicle, survival rates on day 7 after injury induction were 12% in the burn model and 5% in the pancreatitis model, respectively. In both models, hematocrit values were apparently increased and circulating plasma volumes were decreased compared to sham-operated rats at 6 h after injury induction. The pretreatment of animals with dHGF increased the survival rates on day 7 to 40% in the burn model and 29% in the pancreatitis model. dHGF-treatment in normal rats decreased the hematocrit values and increased the circulating plasma volumes, and these changes of hematocrit value and circulating plasma volume were also maintained after injury induction. These findings suggest that dHGF pretreatment prevents the mortality in the severe burn and acute pancreatitis, and that its effect may contribute to ameliorating the progressing of plasma-loss-induced hypovolemia.

Acute Disease↗
PubMed2001

Impairment of learning and memory in rats caused by oxidative stress and aging, and changes in antioxidative defense systems.

To elucidate the influence of oxidative stress on the brain functions during aging, the cognitive performance ability of rats was assessed by using the water-maze test as an oxidative stress before and after hyperoxia. Young rats showed significantly greater learning ability than both old rats and vitamin-E-deficient rats. Although the memory functions of all rats were Impaired after oxidative stress, the memory retention of young rats was greater than those of other groups. After the stress, none of the rats recovered their learning ability. During aging and through hyperoxia, the release of acetylcholine from nerve terminals was remarkably decreased. Instead, thiobarbituric acid reactive substance (TBARS) contents in rat hippocampus and cebral cortex, and their synaptic membranes, were significantly increased during aging and by oxidative stress. The antioxidative defense system in rat brain was also changed by the stress. These results suggest that oxidative stress may contribute to learning and memory deficits following oxidative brain damage during aging.

Acetylcholine↗
PubMed2001

Incomplete decapitation of a motorcyclist from hyperextension by inertia: a case report.

This is a rare case involving a motorcyclist. A 57 year old motorcycle rider wearing a full face type helmet, suffered incomplete decapitation. The autopsy findings revealed a wide lacerated wound accompanied by extension marks in the front neck, atlanto-occipital dislocation and complete transection of the brainstem. According to the police traffic report, the man's head was stationary at the moment of impact and the remainder of the body continued in a backward motion. We concluded that the inertia of the torso caused hyperextension of the neck and subsequent incomplete decapitation.

Accidents, Traffic↗
PubMed2001

Improving glucose metabolism and/or sarcoplasmic reticulum Ca2+-ATPase function is warranted for immature pressure overload hypertrophied myocardium.

The cellular mechanisms of abnormal calcium regulation and excitation-contraction coupling in relation to glucose metabolism in the hypertrophied heart are not well understood. The present study evaluated the myocardial mechanics of 6-7-week-old pressure overload hypertrophied rabbit hearts in response to dobutamine by (1) serial echocardiograms in vivo and (2) isolated Langendorff perfusion. Cytosolic Ca2+([Ca2+]i) and sarcoplasmic reticulum Ca2+-ATPase (SERCA2) expression were measured by fluorescence spectroscopy and Western immunoblotting, respectively. The effect of glycolytic inhibition by 2-deoxy-D-glucose +/- pyruvate was also evaluated. Both systolic and diastolic [Ca2+]i tended to be higher and diastolic calcium removal (tauCa) significantly slower in the hypertrophied heart. The myocardial response to dobutamine was blunted and dobutamine insignificantly improved tauCa. The SERCA2 protein level was higher in early hypertrophy, but was significantly reduced by 6 weeks of age, with progressive contractile failure. Inhibition of glycolysis or SERCA2 caused an increase in [Ca2+]i as well as a slower tauCa. Pyruvate completely preserved myocardial function and [Ca2+]i handling during glycolytic inhibition. It was concluded that in this model of advanced pressure overload hypertrophy, contractile failure and inotrope insensitivity are associated with increased [Ca2+]i, slower tauCa and reduced sensitivity of the contractile proteins to Ca2+. These changes occur in association with downregulation of the SERCA2, probably caused by impaired glucose metabolism.

Animals↗
PubMed2001

Enhanced signal transduction by a directly fused protein of interleukin-6 and its receptor.

In order to develop a new type of agonist for the interleukin 6 (IL-6) signal, the gene encoding a directly fused protein (DFP) was constructed by joining the N-terminal portion of IL-6 and the C-terminal (soluble) portion of IL-6R (sIL-6R) without using a flexible polypeptide linker. The biological activity if DFP from a recombinant Pichia pastoris was examined by growth stimulation of IL-6-dependent BAF130 cells expressing human gp130, a membrane receptor. The recombinant DFP exhibited a much stronger growth stimulation (10 times) than the independent IL-6 and sIL-6R (IL-6/sIL-6R), mainly because association of the IL-6 and IL-6R could be maintained even at lower concentrations of DFP. Surface plasmon resonance (SPR) analysis showed that DFP bound to the extracellular portion of gp130 in the biphasic mode, and the dissociation constants of DFP for two phases were the same as those of IL-6/sIL-6R. In cells treated with DFP, stimulation of Stat3 phosphorylation was maintained for a longer period (150 min) than in cells treated with IL6/Il-6R, suggesting that the signal mediated by the DFP was more durable than that mediated by IL-6/sIL-6R, although the signal transduction mechanisms are almost the same for both DFP and IL-6/IL-6R. Therefore, the stronger activity of DFP was attributed to the maintained association of its subunits and/or prolonged phosphorylation of Stat3.

Journal Article↗
PubMed2001

Utilization of immobilized archaeal chaperonin for enzyme stabilization.

CpkA and CpkB are thermostable chaperonins from hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. CpkA or CpkB was immobilized onto agarose beads by the carbodiimide coupling method. In order to investigate whether immobilized CpkA or CpkB stabilizes a foreign enzyme, their ability to stabilize enzyme was examined using beta-D-galactosidase from Escherichia coli as a model target. In the absence of chaperonin beads, 38.1% of the total soluble protein was precipitated by heat treatment at 53 degrees C for 30 min. The protein structure of the residual soluble fraction was examined by circular dichroism, indicating that beta-D-galactosidase exists as a mixture of the active folded form and the inactive unfolded form. The specific activity of the residual soluble fraction decreased to 85.1% that of the unheated level (from 149.0 U/mg to 127.0 U/mg), indicating that the active folded form in the heated soluble fraction was 85.2%. In the presence of CpkA- or CpkB-beads, 28.6% or 34.3% of beta-d-galactosidase was precipitated by the same heat treatment. However, the specific activity in the soluble fraction was almost maintained (CpkA, from 151.0 U/mg to 140.3 U/mg; CpkB, from 149.0 U/mg to 140.3 U/mg). These results indicated that CpkA- or CpkB-beads are useful for keeping the enzyme active.

Journal Article↗
PubMed2001

Unique nucleoid structure during cell division of Thermococcus kodakaraensis KOD1.

The nucleoid structure and the partition in the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 were observed by a combination of phase-contrast microscopy and fluorescence microscopy. The nucleoids occurred as rounded fluorescent foci centrally located in the cells and as differences in fluorescence intensity between exponential and stationary phases. The cellular space occupied by the nucleoid in the stationary phase was larger than that in the exponential phase. Various shapes of nucleoid in the exponential-phase cells were observed, indicating that nucleoid separation was processed under cell cycle control. The number of cells which showed distinctive division stages was counted and the proportions of dividing cells were determined. About half of the observed cells were in the replication stage. More than 40% of the counted cells possessed a fully replicated but not separated form of nucleoid. Only 8% of the total cells clearly showed visible constriction. These results suggested that the post-replication period before cell division was relatively as long as the eucaryal gap period (G2); however, the period of visible cell constriction was almost the same as that of the bacteria.

Journal Article↗
PubMed2001

Reduction by phytate-reduced soybean beta-conglycinin of plasma triglyceride level of young and adult rats.

This study examined the effects of soybean beta-conglycinin, from which phytate was mostly removed, on the plasma lipids in young and adult rats. Male Wistar young (6 week-old) and adult (21 week-old) rats were fed high cholesterol diets containing 20% casein, soy protein isolate (SPI), or soybean beta-conglycinin for 10 days. In young rats, although the food intake of the beta-conglycinin group was higher than those of the casein and SPI groups, the weight gain was significantly lower than those of the other groups. However, in adult rats, the weight gain was not different among the groups. In young and adult rats, relative liver weights of SPI and beta-conglycinin groups were significantly lower than that of the casein group, and the degree of the reduction was more marked in the beta-conglycinin group than in the SPI group. In young rats, the plasma triglyceride level was significantly lower in the SPI and beta-conglycinin groups than that in the casein group. In addition, the plasma triglyceride level of the beta-conglycinin group was significantly lower than that of the SPI group. Plasma total cholesterol levels of the SPI and beta-conglycinin groups were significantly lower than that of the casein group. However, there was little difference in the lowering effect between SPI and beta-conglycinin. These results indicate that soybean beta-conglycinin may have lowering functions not only on plasma total cholesterol level, but also on plasma triglyceride level.

Aging↗
PubMed2001

Polymorphism in rice amylases at an early stage of seed germination.

A polymorphism in rice amylases at an early stage of seed germination is analyzed by zymogram. In non-glutinous cultivars of rice, alpha-amylase isozymes are mainly confirmed in germinating seeds. However, in glutinous cultivars, beta-amylase isozymes, which are not confirmed in nonglutinous cultivars, make up the major part of the total amylase activity and the expression of alpha-amylases are repressed.

Germination↗
PubMed2001

[An operated case of medial temporal lobe epilepsy associated with schizencephaly].

A 24-year-old male of medial temporal lobe epilepsy associated with schizencephaly was presented. He developed complex partial seizure after head trauma at the age of a year and 7 months, which became intractable at the age of 13 year. MRI demonstrated a schizencephalic cleft in the right peri-Rolandic area, cortical dysplasia in the right medical parietal and occipital lobes, and right hippocampal atrophy. Scalp-recorded EEG failed to localize the ictal onset zone. Interictal FDG-PET and ECD-SPECT indicated hypometabolism and hypoperfusion of the right entire temporal lobe, and ictal ECD-SPECT increased perfusion of this area. Chronic subdural electrode recording clearly demonstrated that ictal onset zone was located not on the schizencephalic cleft or its surrounding cortex but on the right medial temporal lobe. Following right anterior temporal lobectomy with hipppocampectomy, seizure control became easy. For the identification of the epileptogenic zone in patients with schizencephaly, chronic subdural electrode recording is mandatory.

Adult↗
PubMed2001

[Effects of topical prostaglandin analogues on the aqueous flare intensity in rabbit eyes at an early phase of endotoxin-induced uveitis].

PURPOSE: We examined the effects of prostaglandin analogues on the blood-aqueous barrier(BAB) permeability in rabbit eyes at an early phase of endotoxin-induced uveitis(EIU). SUBJECTS AND METHODS: One drop of 0.005% latanoprost or 0.12% unoprostone were applied to rabbit eyes. Escherichia coli lipopolysaccharides were injected to induce uveitis. The changes in flare intensity in normal eyes and EIU eyes after application of eye drops were evaluated. The effect of cyclooxygenase inhibitor on the flare intensity changes caused by the application of unoprostone was also examined. RESULTS: Flare intensity increased significantly after a single instillation of unoprostone, and the increase was not prevented by pretreatment with cyclooxygenase inhibitor. In eyes with EIU, unoprostone caused an additional increase of flare intensity to uveitis induced flare change. Latanoprost had no effects on BAB in eyes with normal and with uveitic conditions. CONCLUSION: Latanoprost and unoprostone did not cause an excessive inflammatory reaction in rabbit eyes at an early phase of EIU.

Animals↗
PubMed2001

[Non-invasive examinations successfully select patients with medial temporal lobe epilepsy for anterior temporal lobectomy].

We retrospectively analyzed 8 patients with intractable medial temporal lobe epilepsy (MTLE) who underwent the anterior temporal lobectomy with hippocampectomy (ATL) without invasive examinations such as chronic subdural electrode recording. Five patients had a history of febrile convulsion. While all 8 patients had oral automatism, automatism of ipsilateral limbs with dystonic posture of contralateral limbs was demonstrated in 2 patients. Bilateral temporal paroxysmal activities on interictal EEG was observed in 4 patients and all patients had clear ictal onset zone on unilateral anterior temporal region. MRI demonstrated unilateral hippocampal sclerosis in 5 cases. Interictal FDG-PET depicted hypometabolism of the unilateral temporal lobe in all cases, however, ECD-SPECT failed to reveal the hypoperfusion of the unilateral temporal lobe in a case. Postoperatively, 7 cases became seizure free, and one had rare seizure. Non-invasive examinations, especially ictal EEG and concordant FDG-PET findings, in patients with oral automatism in seizure semiology, successfully select patients with MTLE for ATL.

Adolescent↗
PubMed2001

[A case showing effective radiotherapy for a radiation-induced glioblastoma].

Radiation-induced glioblastoma is usually resistant to all treatments. We report a case with radiation-induced glioblastoma, in which radiotherapy was remarkably effective. A 14-year-old female with a history of acute lymphoblastic leukemia, at the age of 7, underwent 15 Gy of radiotherapy to the whole brain. She was admitted to our department due to the development of headache and nausea. Magnetic resonance imaging showed an irregularly enhanced mass in the left frontal lobe. Partial removal of the mass was performed and histological examination showed it to be glioblastoma with a high MIB-1 index. The patient underwent 40 Gy of local radiotherapy and chemotherapy with ACNU and Interferon-beta for 2 years. The residual tumor disappeared after the radiotherapy, and her status is still "complete remission", 29 months after the onset.

Adolescent↗