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Biomedical subjects

M Hamamoto

Publications and source records attributed to M Hamamoto.

At least 37 records · Page 2Linked to original sources
PubMed1999

Susceptibility to neuroleptic malignant syndrome in Parkinson's disease.

OBJECTIVE: To determine susceptibility to neuroleptic malignant syndrome (NMS) in patients with PD in relation to central monoamine metabolism. METHODS: CSF levels of homovanillic acid (HVA), 3-methoxy-4-hydroxy phenyletilene glycol (MHPG), and 5-hydroxyindole acetic acid (5-HIAA) were assayed in 98 PD patients (mean age, 77.2 years), including 11 patients with a prior NMS-like episode, by high-performance liquid chromatography with electrochemical detection. RESULTS: Patients with a previous NMS-like episode had worse parkinsonian disability as measured by Hoehn & Yahr scale (3.7 +/- 0.8 versus 3.0 +/- 1.1; p = 0.038) and lower CSF HVA levels (20.9 +/- 17.3 versus 44.7 +/- 22.2 ng/mL; p = 0.001) compared to those without, despite similar age, disease duration, and daily dosages of antiparkinsonian drugs between groups. Logistic regression analysis showed that the CSF HVA level (p = 0.008), but not 5-HIAA level (p = 0.621), was significantly and independently related to NMS, and that the MHPG level (p = 0.070) was tendentially associated with the disorder. Odds ratios (95% confidence intervals) corresponding to 10 ng/mL increment in CSF HVA, MHPG, and 5-HIAA levels were 0.30 (0.13 to 0.73), 4.03 (0.89 to 18.2) and 1.29 (0.47 to 3.58), respectively. CONCLUSIONS: Central dopaminergic and possible noradrenergic activity contributes to NMS development in an elderly population of PD patients. Measuring CSF levels of monoamine metabolites may provide a means for identifying NMS susceptibility in PD patients.

Aged↗
PubMed1999

Kluyveromyces nonfermentans sp. nov., a new yeast species isolated from the deep sea.

Eleven strains of a new species of the genus Kluyveromyces, characterized as having evanescent asci and Q-6 as the major ubiquinone, were isolated from sediments, a clam and a crab collected at depths of 1000-2000 m in Suruga Bay and Sagami Bay, Japan. A phylogenetic tree based on small-subunit (18S) rRNA gene sequences placed these isolates into a cluster of Kluyveromyces. DNA complementarity and phylogenetic trees of internal transcribed spacer (ITS) regions and 5.8S rRNA genes showed that the isolates are closely related to Kluyveromyces aestuarii, but that these two species are genetically distinct. The isolates are described as Kluyveromyces nonfermentans sp. nov. Because this species lacks the fermentative ability considered to be an important criterion for the genus Kluyveromyces, the definition of the genus has been emended. The type strain of K. nonfermentans is strain SY-33T (= JCM 10232T).

Animals↗
PubMed1999

[Surgical anatomy of the facial nerve and chorda tympani with special reference to cochlear implantation].

The surgical anatomy of the facial nerve (FN), chorda tympani nerve (CT) and round window (RW) in 26 Japanese temporal bone specimens was analyzed. The relationships were classified according to the relative position of these structures and the posterior wall of the external auditory canal (EAC). Most frequently, the widest approach route through the facial recess did not point directly at the RW, but rather at the basal turn. Moreover, the approach route crossed the FN-RW line in a posterior to anterior direction (76.9%) and the CT-RW line frequently crossed the posterior wall of the EAC (92.3%). The latter seemed to provide a critical landmark for avoiding damage to the CT during cochlear implant surgery. Therefore, we recommend inserting the electrode into the basal turn at the promontory. Several other anatomical indices were measured and we extracted the index which was related to the maximum approach amplitude and direction. Preoperative diagnosis may be possible using these indices.

Adolescent↗
PubMed1998

Denitrification by yeasts and occurrence of cytochrome P450nor in Trichosporon cutaneum.

Yeasts of various genera were screened for denitrifying activity, and several yeast strains such as Trichosporon cutaneum, Fellomyces fuzhouensis, and Candida sp. were found to exhibit distinct activities to convert nitrite to nitrous oxide. Dissimilatory nitrite reductase (Nir) or nitric oxide reductase (Nor) activities were detected in the cell-free extracts of these yeasts. Spectrophotometric as well as Western blot analyses showed that T. cutaneum contains Nor of the cytochrome P450 type. This is the first report that shows that denitrification is also distributed among yeasts although their systems are incomplete, only capable of reducing nitrite to nitrous oxide.

Anaerobiosis↗
PubMed1998

Fellomyces ogasawarensis sp. nov. and Fellomyces distylii sp. nov., yeasts isolated from a plant in Japan.

Fellomyces ogasawarensis and Fellomyces distylii, new yeast species isolated from a dead leaf of a plant (Distylium-lepidotum Nakai, family Hamamelidaceae) collected in the Ogasawara Islands, isolated islands in the Pacific Ocean about 1000 km south of Japan, are described. The phylogenetic relationship of F. ogasawarensis and F. distylii with other members of the genus Fellomyces was estimated from 18S rRNA gene sequence analysis. The type strain of F. ogasawarensis is strain OK-81 (= JCM 9861) and that of F. distylii is strain OK-83 (= JCM 9862).

DNA, Fungal↗
PubMed1998

[Clinical study of hypopharyngeal carcinoma].

A clinical study was performed of 83 patients with hypopharyngeal cancer treated in the Sapporo Medical University Hospital from 1982 to 1995. Five-year cumulative survival rate was 34.9% in the whole group and 37.2% in the radical surgical and/or radiation treatment group. In the radiation treatment group, the patients with T1, T2, N0 or N1 stage disease, especially those whose original disease responded almost completely to 40Gy irradiation, showed high tumor control rates following full-dose irradiation with or without radical neck dissection. In the radical surgery group, the patients with T4 or N2 stage disease showed better prognosis than those in the radiation group. However, among the patients with N3 lymph node metastases, there were no long-term survivors in either the radiation or the surgery groups.

Adult↗
PubMed1998

Basic and clinical studies on ApoE gene typing by line probe assay (LiPA) as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan.

The fundamental reagent capability and clinical significance of ApoE gene typing has been investigated. The result of each test shows that the reagent capability satisfied the expected standard. Four-hundred thirty-nine samples classified into three groups (Alzheimer's disease (AD), other types of dementia and nondementia) were measured to examine the clinical significance. The rate of epsilon 4 genotype of each group was 31.5%, 14.6%, 10.4%, respectively. The AD group had a higher rate than the other groups (p < 0.001). The measurement of ApoE genotype is suggested to be useful as one of the guidelines in the diagnosis of AD.

Age Factors↗
PubMed1998

Basic and clinical studies on the measurement of tau protein in cerebrospinal fluid as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan.

The development of a diagnostic marker for earlier and more accurate clinical diagnosis of Alzheimer's disease (AD) is essential to identify AD patients during life unequivocally. The purpose of this study was to investigate the basic performance and clinical significance of tau level measurement in the cerebrospinal fluid (CSF) using an enzyme-linked immunosorbent assay (ELISA) developed by Innogenetics. The ELISA system showed reliable reproducibility and good linearity. For clinical studies, the CSF samples from a variety of patients (n = 332) were examined. They were classified into the four groups: Alzheimer's disease (AD); neurodegenerative disease (ND); cerebrovascular diseases (VD); and a neurological control (NC) group. The CSF-tau levels for AD, ND, VD and NC were 426 +/- 234 pg/ml, 239 +/- 157 pg/ml, 216 +/- 136 pg/ml, and 188 +/- 103 pg/ml, respectively. The CSF-tau level of the AD group was significantly higher than that of the other groups (p < 0.001). The CSF-tau levels increased during follow-up. The measurement of the tau level in CSF is shown to be a useful marker to confirm a clinical diagnosis of AD.

Aged↗
PubMed1997

Interaction of chicken gizzard smooth muscle calponin with brain microtubules.

Calponin, a major actin-, tropomyosin-, and calmodulin-binding protein in smooth muscle, interacted with tubulin, a main constituent of microtubules, in a concentration-dependent fashion in vitro. The apparent K(d) value of calponin to tubulin was calculated to be 5.2 microM with 2 mol of calponin maximally bound per 1 mol of tubulin. At low ionic strength, tubulin bound to calponin immobilized on Sepharose 4B, and the bound protein was released at about 270 mM NaCl. Chemical cross-linking experiments showed that a 1:1 molar covalent complex of calponin and tubulin was produced. The amount of calponin bound to microtubules decreased with increasing ionic strength or Ca2+ concentration. The addition of calmodulin or S100 to the mixture of calponin and microtubule proteins caused the removal of calponin from microtubules in the presence of Ca2+, but not in the presence of EGTA. Calponin-related proteins including tropomyosin, SM22, and caldesmon had little effect on the calponin binding to microtubules, whereas MAP2 inhibited the binding. Interestingly, there was little, if any, effect of mycalolide B-treated actin on the binding of calponin to microtubules. Furthermore, only about 20% of calponin-F-actin interaction was inhibited in the presence of an excess amount of tubulin (4 mol per mol of calponin), indicating that tubulin binds to calponin at a different site from that of actin. Compared with MAP2, calponin had little effect on microtubule polymerization.

Actins↗
PubMed1996

Traumatic cervical tracheal disruption: report of two cases.

We report herein the cases of two patients who suffered tracheal disruption, both of whom underwent successful surgical treatment. The first patient was a 48-year-old truck driver who suffered severe dyspnea after jamming his neck in a truck door. An endotracheal tube was unable to be inserted due to bleeding and thus, an emergency tracheostomy was performed. On admission massive subcutaneous emphysema was noted in the neck and anterior chest, and tracheal disruption was confirmed by a lateral neck X-ray, computed tomography (CT), and fiberscopy. An emergency end-to-end anastomosis of the trachea with insertion of a T-type silicon tube into the lower trachea was performed. The second patient was a 36-year-old man who suffered severe dyspnea after having his neck caught in a chain while driving a motorcycle. On admission, marked subcutaneous emphysema in the neck and paradoxical movement of the trachea were noted. Tracheal disruption was confirmed by a lateral neck X-ray and CT, and a similar operation to that of the first patient was performed. This type of injury is rare; however, lateral neck X-ray, CT, and fiberscopy proved extremely useful for making an accurate diagnosis following which successful emergency surgery was able to be performed, achieving good long-term results.

Adult↗
PubMed1996

Ballistosporous yeasts found on the surface of plant materials collected in New Zealand. The genera Bensingtonia and Bullera with descriptions of five new species.

In the present study, strains from the surface of plant materials collected in New Zealand that belong to the genera Bensingtonia and Bullera are classified. One strain of Bensingtonia was assigned to Ben. ingoldii, while the remaining strain was assigned to Ben. naganoensis based on DNA-DNA reassociation experiment. Twenty-one of 28 Bullera strains were assigned to B. alba (11 strains), B. crocea (6 strains) and B. variabilis (4 strains). The remaining seven strains could not be assigned to any previously known species and were described as the new species, B. coprosmaensis (1 strain), B. hannae (1 strain), B. huiaensis (1 strain), B. mrakii (3 strains) and B. unica (1 strain).

Base Composition↗
PubMed1996

Spontaneous immunoglobulin production by adenoidal and tonsillar lymphocytes in relation to age and otitis media with effusion.

Spontaneous immunoglobulin (Ig) production by autologous adenoidal and tonsillar lymphocytes cultured without any mitogen was measured by an enzyme-linked immunosorbent assay (ELISA) in 18 children with or without otitis media with effusion (OME). Both IgG and IgA levels synthesized by adenoidal or tonsillar lymphocytes significantly increased with age. The average concentrations of IgG and IgA produced by adenoidal lymphocytes from children with OME were significantly lower than those from children without OME. Adenoidal lymphocytes produced IgG and IgM at significantly lower levels than autologous tonsillar lymphocytes did in children with OME. In contrast, no significant difference between adenoidal and tonsillar lymphocytes was seen on Ig production for any isotypes in children without OME. These results may indicate immunological impairment of the adenoids associated with OME.

Adenoids↗
PubMed1996

[Monoamine imbalance of the central nervous system in a case of Shy-Drager syndrome with recurrent attacks of a neuroleptic malignant syndrome].

A 79-year-old male suffering from Shy-Drager syndrome was treated with a daily dosage of 300 mg of L-threo-3,4-dihydroxyphenylserine (L-DOPS). He developed a neuroleptic malignant syndrome (NMS) like state 1 month after teh initiation of L-DOPS therapy. And recurrent attacks of NMS occurred subsequently despite discontinuation of L-DOPS administration. We measured homovanillic acid (HVA), 3 methoxy 4 hydroxyphenylethylenglycol (MHPG), and 5-hydroxyindoleacetic acid (5-HIAA) in this corrected brospinal fluid (CSF), both during his 2 attacks of NMS and after recovery. The HVA and 5 HIAA levels after recovery were low compared with those in age-matched normal controls. However, his levels in the active phase were not different from those after recovery. In contrast, MHPG levels were elevated and his HVA/MHPG ratios decreased in the active phase compared with those in the recovery phase. The results indicate that his symptoms of NMS are attributed to the imbalance between dopamine and noradrenalin rather than the dopamine receptor blockade in the central nervous system. We suggest further evaluations of CSF monoamine metabolites in similar cases to determine the pathogenesis of NMS.

Aged↗
PubMed1995

Ballistosporous yeasts found on the surface of plant materials collected in New Zealand. 1. Six new species in the genus Sporobolomyces.

Six new species of ballistosporous yeast, the genus Sporobolomyces, were isolated from dead leaves and fruit of plants collected in New Zealand; Sp. novazealandicus, Sp. dimmenae, Sp. coprosmicola, Sp. coprosmae, Sp. dracophyllus, and Sp. taupoensis. These species differ from any hitherto known species of Sporobolomyces based on chemotaxonomic characteristics.

Base Composition↗
PubMed1995

Detection of varicella-zoster virus genome having a PstI site in the ocular sample from a patient with acute retinal necrosis.

We detected the virus genome in ocular samples from a 65-year-old woman with clinically diagnosed acute retinal necrosis using DNA amplification. She exhibited occlusive retinal vasculitis, confluent necrotizing retinitis, mainly peripheral, and iridocyclitis. For DNA amplification, we used recently published primers specific for varicella-zoster virus (VZV) and herpes simplex virus. Using VZV primers, we detected the VZV genome in the aqueous humor, but not in the vitreous, by amplifying a DNA fragment 642 base pairs in length. HSV DNA was not detected. After detecting the VZV genome, PstI restriction endonuclease was used because an epidemiological study found that about 25% of the VZV strains in Japan carry a mutation lacking a PstI recognition site. The VZV genome from the patient had a PstI cleavage pattern, while the positive control had a VZV genome that carried a PstI-site-less mutation. We considered our patient with acute retinal necrosis to be infected with VZV having a PstI site.

Aged↗
PubMed1995

Platelet activation is not involved in acceleration of the coagulation system in acute cardioembolic stroke with nonvalvular atrial fibrillation.

BACKGROUND AND PURPOSE: It is generally accepted that the coagulation system is activated in ischemic stroke and that platelet activation is involved in the pathogenesis of this disease. However, little is known about how and to what extent platelet activity participates in coagulation system enhancement. We evaluated the hemostatic condition, especially with regard to platelet function and the coagulation system, within 3 days of onset of acute stroke. The study participants were limited to elderly patients with cardioembolic stroke due to nonvalvular atrial fibrillation. METHODS: Seventeen elderly patients with acute cardioembolic stroke due to nonvalvular atrial fibrillation were investigated. Within 3 days of stroke onset, beta-thromboglobulin (BTG), platelet factor 4 (PF4), thrombin-antithrombin III complex (TAT), and D-dimer from arterial blood were carefully evaluated in these patients. Blood samples from 19 healthy age- and sex-matched control subjects were also examined. RESULTS: The two studied markers of platelet activity did not change in the patients or the control subjects, and the between-group differences between the stroke and control groups were not statistically significant (BTG, 43.8 versus 31.9 ng/mL; PF4, 9.06 versus 5.78 ng/mL; respectively). In contrast, the two studied coagulation-system indicators were markedly elevated in the patients compared with the control subjects (TAT, 13.8 versus 3.5 ng/mL, P < .01; D-dimer, 366.3 versus 147.2 ng/mL, P < .01; respectively). CONCLUSIONS: Platelet function was not enhanced in the acute stage of cardioembolic stroke with nonvalvular atrial fibrillation. This result indicates that enhancement of the coagulation system in cardioembolic stroke is not the result of platelet hyperfunction, ie, "platelet-fibrin" thrombi, but rather of "stasis-related" thrombi formation.

Aged↗