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Biomedical subjects

K Wada

Publications and source records attributed to K Wada.

At least 91 records · Page 5Linked to original sources
PubMed2001

Preferential conditions for and possible mechanisms of induction of ischemic tolerance by repeated hyperbaric oxygenation in gerbil hippocampus.

OBJECTIVE: We reported previously that repeated hyperbaric oxygenation (HBO) as pretreatment induced ischemic tolerance in the gerbil hippocampus. This study was conducted to determine the preferential conditions for induction of ischemic tolerance by HBO and the mechanism of this induction through immunohistochemical analysis of Bcl-2, Bax, and manganese superoxide dismutase expression. METHODS: Five-minute forebrain ischemia was produced in gerbils after pretreatment with 2 atmospheres absolute (ATA) HBO once every other day for one, three, or five sessions, 2 ATA hyperbaric air once every other day for five sessions, or 3 ATA HBO once daily for 10 sessions. Histological examinations were then performed. Two days after pretreatment with 2 ATA HBO once every other day for five sessions or with 3 ATA HBO once daily for 10 sessions, sections were analyzed immunohistochemically. RESULTS: Pretreatment with 2 ATA HBO once every other day for three or five sessions induced ischemic tolerance; however, pretreatment with 2 ATA HBO for one session, 2 ATA hyperbaric air once every other day for five sessions, or 3 ATA HBO once daily for 10 sessions did not. Pretreatment with 2 ATA HBO once every other day for five sessions, but not with 3 ATA HBO once daily for 10 sessions, significantly increased Bcl-2 and manganese superoxide dismutase immunoreactivity in the CA1 sector. CONCLUSION: These results suggest that protection against mitochondrial alterations after ischemia through manganese superoxide dismutase and/or Bcl-2 expression may be related to induction of ischemic tolerance by repeated HBO pretreatment.

Animals↗
PubMed2001

Crystallization and preliminary X-ray analysis of a novel pectolytic enzyme, polymethoxygalacturonase SX1 from Trichosporon penicillatum.

A novel pectolytic enzyme, polymethoxygalacturonase SX1 from Trichosporon penicillatum, with a molecular weight of 36 kDa was crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 1000 as a precipitant. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 165.6, b = 61.0, c = 48.7 A, beta = 93.1 degrees. The calculated V(M) based on one molecule per asymmetric unit was 3.40 A(3) Da(-1). A native data set was collected to 2.08 A resolution from a crystal on a Cu Kalpha rotating-anode X-ray source. A molecular-replacement solution was obtained using the program AMoRe and the structure of endopolygalacturonase II from Aspergillus niger as a model.

Crystallization↗
PubMed2001

Purification, crystallization and preliminary X-ray diffraction analysis of the fructose-1,6-/sedoheptulose-1,7-bisphosphatase of Synechococcus PCC 7942.

Fructose-1,6-/sedoheptulose-1,7-bisphosphatase of Synechococcus PCC 7942, overexpressed from Escherichia coli, has been purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. The crystals were monoclinic, with unit-cell parameters a = 80.1, b = 84.2, c = 104.3 A, beta = 101.7 degrees. They belonged to space group P2(1) and diffracted to at least 2.2 A resolution. The calculated V(M) value, based on a tetramer in the asymmetric unit, was 2.2 A(3) Da(-1).

Crystallization↗
PubMed2001

A new method to catheterize a femoral artery in mice using a nylon suture as a 'guide wire'.

Mice are commonly used in laboratory experiments. Their femoral arteries are so tiny that catheterization is quite difficult. We describe a new method to catheterize the femoral artery in mice. The key feature of this new method is the use of a nylon suture as a 'guide wire'. The full catheterization system consists of two sizes of polyethylene tubes (PE-10, PE-50) and a 4-0 nylon suture. We have been able to repeatedly catheterize mouse femoral arteries (n = 57) successfully and easily with this new system. We believe that this new method can facilitate vascular catheterization in small animals such as mice.

Animals↗
PubMed2001

[Amotivational syndrome in organic solvent abusers].

Amotivational syndrome is a chronic psychiatric disorder characterized by a variety of changes in personality, emotions and cognitive functions such as lack of activity, inward-turning, avolition, apathy, incoherence, blunted affect, inability to concentrate and memory disturbance. The syndrome was first described among those patients with a history of longtime cannabis use in the 1960's. Since then, there have been several reports describing similar psychiatric disorders to amotivational syndrome among patients with the history of some other psychoactive substances use including solvents, methamphetamine and OTC cough syrups. Therefore, the syndrome has been recognized as one of the common psychiatric conditions that might develop in patients with a history of any psychoactive substance use. Recently, more attention has been paid to the biological basis of amotivational syndrome. Several studies using MRI, SPECT or neuropsychological measures have revealed white matter changes, hypoperfusion in the frontal cortex of the brain and impairment of frontal lobe function. Those findings suggest that amotivational syndrome might be related to "hypofrontality" of the brain. Although no specific treatments have been reported to be definitely effective for patients with amotivational syndrome, some neuroleptics with activating properties or antidepressants can be given appropriately to treat the chief symptoms of the patients.

Antidepressive Agents↗
PubMed2001

Peduncular hallucinosis due to a pineal meningioma. Case report.

The authors report the case of a 53-year-old woman who experienced visual hallucinations diagnosed as peduncular hallucinosis (PH). The cause of the PH was compression of the quadrigeminal plate and/or the splenium due to a meningioma originating from the falcotentorial junction (pineal meningioma). The nature of the visual hallucinations was depicted in drawings created by the patient herself. This is the first report of PH caused by a tumor located in the pineal region.

Female↗
PubMed2001

[Murine IgE antibody to recognize human major allergen, Mal f4].

To elucidate the specificity of murine IgE antibody against Malassezia furfur, the immunoblot patterns of IgE in sera obtained from mice inoculated repeatedly in the nasal cavity with M. f. cells, or injected intraperitoneally with M. f. cells mixed with Al (OH)3 gel were compared with those of IgE antibody detected in sera from patients with AD. Most of the murine IgE anti-Malassezia antibodies shared some antigenic bands with IgE in sera from patients with AD. The IgE antibody of murine also recognized Mal f4, one of the major allergens detected in patients with AD.

Allergens↗
PubMed2001

[Perspectives on postgenome medicine: Neurodegenerative disease].

The genes of the majority neurodegenerative disorders have been identified for the past decade. Diseases of early onset are usually transmitted as autosomal recessive trait and caused by the deficiency of the gene products, becoming good candidates for gene or protein transfers. Late onset diseases are usually transmitted dominantly where the gains of function by the mutant gene accumulate into specific lesion. The pathophysiology following gene mutation need to be clarified for the therapeutic approach. Recent progresses on neurodegenerative mechanism have specified crucial targets for the treatments. Stimulation to intrinsic mechanisms, i.e., chaperon, ubiquitin-proteasome system and stress response in endoplasmic reticulum and/or antagonize the toxic cascade by caspases, mitochondria insufficiency are argued as therapeutic targets, hoping that in this decade we can propose effective therapies for these devastating disorders.

Animals↗
PubMed2001

[Injectable quinolones].

Fluoroquinolones have been used worldwide against a variety of infections because of their potent antibacterial activity and good pharmacokinetics. In Europe and USA, ciprofloxacin and levofloxacin showed a good therapeutic efficacy for the past decade by sequential therapy for infections caused by Gram-negative bacteria including Pseudomonas aeruginosa and Gram-positive pathogens including penicillin-resistant Streptococcus pneumoniae. Recently, injection form of ciprofloxacin was launched in Japan, and pazufloxacin, gatifloxacin, and sitafloxacin are under development. Appropriate usage of these injectable quinolones in Japanese medical practice should be established from the potency of each drug, the surveillance data of drug-resistance, and the experience in Europe and USA.

Animals↗
PubMed2001

[Drinking behaviors of Japanese adolescents' problem drinker--report of 1996 national survey].

The first national survey of Japanese adolescent drinking behaviors was conducted in 1996. Based on the survey results, this study focused on high risk drinking behaviors of Japanese adolescent problem drinkers. The subjects were 42,183 junior high school students and 72,396 senior high school students who responded to questions on drinking frequency and drinking quantity among the national survey subjects. The subject students were divided into three groups: normal adolescents, drinkers and problem drinkers by the QF scale. The problem drinkers according to the QF scale accounted for 3% of the junior high school students and 14% of senior high school students. Problem drinkers among both junior and senior high school students had characteristic drinking behaviors such as various drinking occasions, obtaining alcoholic drinks by various methods, drinking hard liquor, and many instances of vomiting or blackouts due to drinking. Many problem drinkers considered that the national law prohibiting minors from drinking was unnecessary because they have the right to decide whether to drink. Both junior and senior high school problem drinkers showed high risk drinking behaviors.

Adolescent↗
PubMed2001

Lifetime prevalence of alcohol drinking, cigarette smoking, and solvent inhalation among junior high school students in Japan: tradition and urbanization.

To estimate the lifetime prevalence of alcohol drinking, cigarette smoking, and solvent inhalation among general junior high school students in Chiba prefecture, the author surveyed 6,115 students enrolled in 14 junior high schools in 1992. The lifetime prevalence of alcohol drinking was 78.4% of male subjects, 72.8% of female subjects, and 75.6% of all subjects. The lifetime prevalence of cigarette smoking was 30.7%, 14.9%, and 22.9%, respectively. The lifetime prevalence of solvent inhalation was 2.5%, 1.2%, and 1.9%, respectively. The past-year prevalence of solvent inhalation was 1.8%, 0.9%, and 1.4%, respectively. Furthermore, to reveal the relationship between the prevalence of drug use and the regional characteristics, multiple regression analysis was performed, using 7 indices that seemed to represent the regional characteristics. The multiple regression analysis revealed the following: 1) that the lifetime prevalence of alcohol drinking and cigarette smoking had a strong standardized partial regression coefficient with the percentage of owner occupants (Mochiieritsu in Japanese) and 2) that the lifetime and the past-year prevalence of solvent inhalation had a strong standardized partial regression coefficient with the ratio of daytime population to nighttime population (Chuyakanjinkouhi in Japanese). The author considered that these coefficients represented the relationship between traditional lifestyle and urbanization and drug use among junior high school students in Japan.

Adolescent↗
PubMed2001

Maxillary sinus floor augmentation in rabbits: a comparative histologic-histomorphometric study between rhBMP-2 and autogenous bone.

The present study was designed to compare recombinant human bone morphogenetic protein-2 (rhBMP-2) impregnated on an absorbable collagen sponge (ACS) with particulate cancellous bone and marrow (PCBM) harvested from the iliac crest in an animal model of maxillary sinus floor augmentation. Bilateral sinus floor augmentation procedures were performed in 30 adult Japanese white rabbits. rhBMP-2/ACS or PCBM was grafted to each maxillary sinus. Animals were sacrificed at 2, 4, or 8 weeks after grafting, and bone formation in response to each implant was evaluated histologically and histometrically. Histometric results compared by analysis of variance revealed no statistically significant difference in the bone volume at augmented areas between the two types of implant (P > 0.05). Histologic evaluation documented that the trabeculae with a lamellar structure were embedded in fatty marrow at 8 weeks in both implant sites. These results suggest that sinus floor augmentation with rhBMP-2/ACS or PCBM induces comparable histologic and histometric evidence of bone formation in rabbits.

Alveolar Ridge Augmentation↗
PubMed2001

[Determination of 4-O-methylpyridoxine (MPN) by HPLC with diode-array detector].

We have developed a simple and rapid method for measuring 4-O-methylpyridoxine (MPN) in the serum of an acute poisoning patient by high-performance liquid chromatograph (HPLC) with a diode-array detector. MPN, a poisonous ingredient of ginkgo seeds was extracted using an Isolute C18 solid-phase extraction column. Equal volumes of the extract were injected into a C18 HPLC column using acetonitrile-10 mM phosphate buffer (pH 3) as the mobile phase. Excellent linearity was obtained over the range of 1-1000 ng at a wavelength of 290 nm, and its detection limit of approximately 0.5 ng was considered to be satisfactory. The mean recovery of MPN in the serum was 92.9 +/- 6.1%. The method was used successfully in a case of acute poisoning.

Chromatography, High Pressure Liquid↗
PubMed2001

[Serological diagnosis of pulmonary tuberculosis and nontuberculous pulmonary mycobacteriosis].

OBJECTIVE: The present study was undertaken to evaluate the utility of the serodiagnosis of pulmonary tuberculosis and nontuberculous pulmonary mycobacteriosis by ELISA using a Pathozyme-Myco kit (Myco kit) and a Pathozyme-TB complex kit (TB kit) (OMEGA Diagnostics Ltd.). STUDY POPULATION: The subjects comprised 256 healthy volunteers (HV, healthy hospital employees), 66 patients with sputum-positive active pulmonary tuberculosis (apTB), 14 patients with healed pulmonary tuberculosis (hpTB), 24 patients with nontuberculous pulmonary mycobacteriosis (NTM) and 32 patients with pulmonary diseases other than mycobacteriosis. RESULTS: 1) The serum IgG antibody titers determined with the Myco kit were significantly higher in the apTB group (p < 0.01), the hpTB group (p < 0.01), and the NTM group (p < 0.01) than those in the HV and the other pulmonary disease group. At a cut-off value of the mean + 2SD of the values obtained in the HV, the positive rate was 47.0% in patients with apTB, 50.0% in those with NTM, 21.4% in those with hpTB, 3.1% in those with other pulmonary diseases, and 1.6% in the HV. Analysis of ROC curves showed that the HV and the pulmonary mycobacteriosis group (apTB and NTM) were best distinguished by a cut-off value of -0.280 OD (log), with the sensitivity and the specificity being 83.3% and 78.5%, respectively. It was impossible to distinguish apTB from NTM. 2) The serum IgG antibody titers determined with the TB kit were significantly higher in the apTB group than those in the HV (p < 0.01), the NTM group (p < 0.05) and the other pulmonary disease group (p < 0.01). No significant difference was observed between the HV and the patients with NTM or those with other pulmonary diseases. Although the positive rate of the test was low in the apTB group (42.4%), there was a significant difference between apTB and NTM (12.5%) (p < 0.05), suggesting that apTB could be distinguished from NTM. 3) Since the serum antibody titers determined by the Myco kit showed no significant difference between apTB and NTM, and there was also no difference in the positivity between the two diseases, we performed serologic examination using the Myco kit to detect both diseases as pulmonary mycobacteriosis. After diagnosing pulmonary mycobacteriosis by the Myco kit, we then used the TB kit to separate apTB from NTM. In this case, the sensitivity and specificity of the test were 55.6% and 85.7%, respectively. Better methods should be developed to distinguish apTB from nontuberculous mycobacteriosis.

Adult↗
PubMed2001

[The ubiquitin-proteasome system and neurodegeneration].

Many studies have suggested the ubiquitin-proteasome system played an essential role in the pathogenesis of neurodegenerative disorders. In 1999, we provided evidence that a mutation of the system could directly cause neurodegeneration using the gad mouse. Namely, we identified the gad mutation was caused by an intragenic deletion of a gene encoding ubiquitin C-terminal hydrolase 1(UCH-L1), which is a member of de-ubiquitinating enzyme family. In human, missense mutation of UCH-L1 gene was reported in a German family with Parkinson's disease. As well, the parkin gene product was revealed to be an E3 ubiquitin ligase which recognize a form of alpha-synuclein as a substrate. Thus, the investigation of the ubiquitin-proteasome system should provide a clue for understanding neurodegeneration. We have characterized UCH-L1 and identified candidates of endogenous substrates as well as interacting proteins of UCH-L1. In addition, we found amount of monomeric ubiquitin was decreased in the brain of the gad mouse compared with wild type mice. We have also tried to develop "protein therapy" using UCH-L1 protein with TAT sequence. We observed the protein was delivered to brain after intraperitoneal injection in the wild type mouse. This approach would provide a new therapeutic strategy for neurodegeneration.

Animals↗
PubMed2000

Dysfunction of M-channel enhances propagation of neuronal excitability in rat hippocampus monitored by multielectrode dish and microdialysis systems.

To explore the pathogenesis of benign familial neonatal convulsions (BFNC), we determined effects of KCNQ-related M-channels (KCNQ-channels) on hippocampal glutamate (Glu) and gamma-aminobutyric acid (GABA) releases using microdialysis, and propagation of evoked field-potentials (FP) using multielectrode (64-ch)-dish system as two-dimensional monitoring. KCNQ-channel inhibitor, Dup996, enhanced hippocampal K(+)-evoked Glu and GABA releases without affecting basal releases of them. Dup996 unaffected FP-amplitude, but enhanced FP-propagation. The GABA(A)-receptor antagonist, bicuculline, enhanced the stimulatory effects of Dup996 on FP-propagation, however, this stimulatory effects of Dup996 were abolished by the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/glutamate-receptor antagonist, DNQX. These results suggest that the occurrence of BFNC cannot be produced by KCNQ-channel dysfunction alone, but by reciprocal action between impaired KCNQ-channel and other unknown elements (possibly dysfunction of inhibitory neurotransmission system).

Action Potentials↗