Biomedical subjects

M Honda

Publications and source records attributed to M Honda.

At least 163 records · Page 9Linked to original sources

PubMed2000

[A case of ammonium urate urinary stones with anorexia nervosa].

A 27-year-old woman had been suffering from bulimia and habitual vomiting for about 7 years and was incidentally found to have right renal stones by computed tomography. She was referred to our hospital for the treatment of these caluculi. On admission, she presented with hypokalemia, hypochloremia and metabolic alkalosis and was diagnosed with anorexia nervosa. Following successful removal by percutaneous nephrolithotripsy and extracorporeal shockwave lithotripsy the stones were found to consist of pure ammonium urate. Since the urine of an anorexia nervosa patient tends to be rich in uric acid and ammonium, anorexia nervosa seems to be associated with ammonium urate urinary stones.

Adult↗

PubMed2000

Rapid detection of homologously integrated DNA fragments and accurate quantitation of their copy number in transgenic Aspergillus oryzae by PCR.

A simple and rapid method for the analysis of artificially introduced DNA fragments has been developed using competitive PCR and long and accurate PCR. The locus and the copy number of the DNA fragments in each Aspergillus oryzae transformant could be detected more rapidly and accurately by this method than by the conventional Southern hybridization method.

Journal Article↗

PubMed1999

Fas-resistance in ATL cell lines not associated with HTLV-I or FAP-1 production.

A preventive role for human T-cell leukemia virus type-I (HTLV-I) and Fas-associated phosphatase-1 (FAP-1) in Fas-mediated apoptosis has been reported in HTLV-I-infected cells. In the present study, we examined whether these molecules increased during the acquisition of Fas-resistance in adult T-cell leukemia (ATL) cell lines. SO4, ST1 and KK1 are Fas-sensitive ATL cell lines, and produce small amounts of HTLV-I in vitro. Although their subclones RSO4 and RST1 are completely Fas-resistant, they produced an equivalent amount of HTLV-I to SO4 and ST1. Moreover, FAP-1 mRNA was not detected in these cell lines irrespective of Fas sensitivity. Thus, Fas resistance in ATL cells was not directly associated with the increased production of HTLV-I or FAP-1.

Antibodies, Monoclonal↗

PubMed1999

Structure and distribution of rat menin mRNA.

Menin is a protein product of a tumor suppressor gene MEN1, mutations of which are responsible for multiple endocrine neoplasia type 1, an autosomal dominant familial cancer syndrome. We isolated rat menin cDNA clones from a fetal rat brain cDNA library. We also determined the nucleotide sequence of the protein coding region of mouse menin cDNA, which was partly registered in the expressed sequence tag (EST) database. Deduced amino acid sequences of rat and mouse menin are highly homologous to human menin. All of the previously reported disease-associated missense mutations and single amino acid deletions were observed at the residues that are conserved among these three species. Rat MEN1 transcripts were detected not only in the endocrine tissues but also in the tissues of the nervous, digestive, reproductive and immune systems. The MEN1 transcripts were abundantly expressed in the developing rat brain on day 14-18 of gestation. Immunoblotting and immunocytochemical analysis of the COS-7 cells transfected with a rat menin-expression vector revealed that the translated product has a molecular mass of approximately 70 kDa, and is localized mainly in the nucleus. These findings are consistent with those reported on human menin.

Amino Acid Sequence↗

PubMed1999

Genetic similarity of HIV type 1 subtype E in a recent outbreak among injecting drug users in northern Vietnam to strains in Guangxi Province of southern China.

To investigate the molecular epidemiology of a recent HIV-1 outbreak in northern Vietnam and its relation to the epidemic in surrounding areas, we analyzed 17 HIV-positive blood specimens from 3 heterosexuals, 2 sexually transmitted disease patients, and 12 injecting drug users (IDUs), collected in 4 provinces near Hanoi in 1998. These were compared with the specimens from Ho Chi Minh City (n = 10) and An Giang Province (n = 10) in southern Vietnam and with published sequences from neighboring countries. Genetic subtyping based on the env C2/V3 sequences revealed that HIV-1 subtype E predominated throughout Vietnam in all risk populations; the exception was one typical United States-European-type HIV-1 subtype B detected in a patient in Ho Chi Minh City, the first case of HIV infection identified in Vietnam in 1990. The HIV-1 subtype E sequences identified in 9 of the 12 IDUs from northern provinces were closely related phylogenetically to those in IDUs in nearby Guangxi Province of China, and also shared a common amino acid signature downstream of the env V3 loop region. The low interperson nucleotide diversity among IDUs in northern Vietnam supports the view that HIV-1 subtype E was introduced recently among IDUs in northern Vietnam. These data indicate a linkage between HIV-1 circulating among IDUs in northern Vietnam and southern China, and suggest recent transborder introductions as the likely source of HIV-1 subtype E in northern Vietnam.

Adolescent↗

PubMed1999

Novel polymorphism in the promoter region of the tumor necrosis factor alpha gene: No association with narcolepsy.

The striking evidence of almost 100% association of narcolepsy with human leukocyte antigens (HLA) DR2(DR15) antigen is an important clue to elucidate the molecular basis of this sleep disorder. The gene for tumor necrosis factor alpha (TNF alpha) is located in the HLA class II gene cluster. Recent studies have indicated that TNF alpha plays an important role in the regulation of normal human sleep, and regulation of this cytokine may be disturbed in narcolepsy. We searched for a mutation associated with narcolepsy in the promoter region of the TNF alpha gene by single-strand conformation polymorphism analysis. A novel polymorphism, C-850T, was found in narcoleptic patients. Genotype frequency was examined by restriction fragment length polymorphism method. No significant difference of genotype distribution was found between 92 patients with narcolepsy and 91 normal controls. These results do not support our hypothesis that genetic abnormality of TNF alpha production is pathogenetic for narcolepsy.

Alleles↗

PubMed1999

Differential effects of (R)- and (S)-8-hydroxy-2-(di-n-propylamino)tetralin on the monosynaptic spinal reflex in rats.

We examined the effects of (R)- and (S)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT) on the monosynaptic spinal reflex in rats. In intact rats, (R)-8-OH-DPAT (10 microg/kg, i.v.) enhanced the amplitude of the monosynaptic reflex, whereas at 100 microg/kg, it reduced the amplitude. (S)-8-OH-DPAT enhanced the monosynaptic reflex dose-dependently. In spinalized rats, (R)-8-OH-DPAT produced dose-dependent inhibition, but the (S)-enantiomer did not affect the monosynaptic reflex. Pretreatment with spiroxatrine or 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl]-piperazine (NAN-190) inhibited (R)-8-OH-DPAT-induced monosynaptic reflex enhancement in intact rats, as did 5-hydroxytryptamine (5-HT) depletion. Ketanserin reduced the effect of (R)-8-OH-DPAT. These pretreatment regimens had no effect on the monosynaptic reflex depression produced by the (R)-enantiomer in intact and spinalized rats. Pretreatment with prazosin inhibited (S)-8-OH-DPAT-induced monosynaptic reflex enhancement in intact rats, as did noradrenaline and 5-HT depletion. These results suggest that supraspinal 5-HT1A receptors and the descending serotonergic system are involved in the stimulatory effect of (R)-8-OH-DPAT on the monosynaptic reflex, while both the descending serotonergic and noradrenergic systems, the latter acting via alpha1-adrenoceptors, are involved in the effect of the (S)-enantiomer on this reflex.

5,6-Dihydroxytryptamine↗

PubMed1999

Activities of the primary and supplementary motor areas increase in preparation and execution of voluntary muscle relaxation: an event-related fMRI study.

Brain activity associated with voluntary muscle relaxation was examined by applying event-related functional magnetic resonance imaging (fMRI) technique, which enables us to observe change of fMRI signals associated with a single motor trial. The subject voluntarily relaxed or contracted the right upper limb muscles. Each motor mode had two conditions; one required joint movement, and the other did not. Five axial images covering the primary motor area (M1) and supplementary motor area (SMA) were obtained once every second, using an echoplanar 1.5 tesla MRI scanner. One session consisted of 60 dynamic scans (i.e., 60 sec). The subject performed a single motor trial (i.e., relaxation or contraction) during one session in his own time. Ten sessions were done for each task. During fMRI scanning, electromyogram (EMG) was monitored from the right forearm muscles to identify the motor onset. We calculated the correlation between the obtained fMRI signal and the expected hemodynamic response. The muscle relaxation showed transient signal increase time-locked to the EMG offset in the M1 contralateral to the movement and bilateral SMAs, where activation was observed also in the muscle contraction. Activated volume in both the rostral and caudal parts of SMA was significantly larger for the muscle relaxation than for the muscle contraction (p < 0.05). The results suggest that voluntary muscle relaxation occurs as a consequence of excitation of corticospinal projection neurons or intracortical inhibitory interneurons, or both, in the M1 and SMA, and both pre-SMA and SMA proper play an important role in motor inhibition.

Adult↗

PubMed1999

Morphogenesis of liposomes encapsulating actin depends on the type of actin-crosslinking.

To study the morphogenesis of cells caused by the organization of their internal cytoskeletal network, we characterized the transformation of liposomes encapsulating actin and its crosslinking proteins, fascin, alpha-actinin, or filamin, using real-time high-intensity dark-field microscopy. With increasing temperature, the encapsulated G-actin polymerized into actin filaments and formed bundles or gels, depending on the type of actin-crosslinking protein that was co-encapsulated, causing various morphological changes of liposomes. The differences in morphology among transformed liposomes indicate that actin-crosslinking proteins determine liposome shape by organizing their specific actin networks. Morphological analysis reveals that the crosslinking manner, i.e. distance and angular flexibility between adjacent crosslinked actin filaments, is essential for the morphogenesis rather than their binding affinity and stoichiometry to actin filaments.

Actinin↗

PubMed1999

Mismatch negativity and N2b attenuation as an indicator for dysfunction of the preattentive and controlled processing for deviance detection in schizophrenia: a topographic event-related potential study.

The present study compares the amplitudes and topographic patterns of mismatch negativity (MMN) and N2b in schizophrenic patients and normal controls. Twenty-one schizophrenic outpatients and 19 normal volunteers participated in the study. Event-related potentials (ERPs) were recorded in a selective attention task. During the task, subjects were required to focus on one ear, counting deviant stimuli, those deviating in duration from a sequence of standard stimuli. MMN was significantly attenuated in the schizophrenics as compared with the normals in the frontocentral regions. In addition to MMN, the N2b amplitude was also reduced, which showed a significant correlation with the MMN amplitude in the schizophrenics. The late negativity elicited by the deviant stimuli in the unattended condition showed different topographical features between the groups. Whereas the normals showed a lateralized distribution with an ear-related asymmetry, similar to that of the N2b, the schizophrenics showed a frontal dominance, coinciding with the sustained negativity reported by Näätänen et al. (1982), which reflects the automatic preparation for detecting possible subsequent stimulus changes. The amplitude of the sustained negativity was significantly correlated with the performance level in the schizophrenics. The results indicated that although both preattentive and controlled processings are impaired, schizophrenic patients, presumably due to the deficient controlled processing, owe much to automatic processing in the deviant stimulus detection process.

Acoustic Stimulation↗

PubMed1999

Histologic effects of ruby laser hair removal in Japanese patients.

BACKGROUND AND OBJECTIVE: Hair removal by lasers has recently become a popular method to remove unwanted hair. However, histologic changes in human skin before and after exposure to lasers have not been thoroughly investigated. The aim of this study was to clarify the differences that occur immediately after laser exposure and 1 month after laser exposure. STUDY DESIGN/MATERIALS AND METHODS: Eight adult Japanese volunteers were recruited for this study. They were treated with a long pulsed ruby laser at 20 J/cm(2). A single 3-mm punch biopsy of the laser-treated sites was obtained immediately after laser irradiation and at the 1-month follow-up visit, and they were analyzed using hematoxylin and eosin, PAM, and immunohistological staining. RESULTS: Immediately after laser exposure, hair follicles were very damaged and had extensive eosinophilic degeneration. One month after laser therapy, one type of hair follicle showed cystlike formations with negative proliferating cell nuclear antigen reactions (PCNA). Another type of hair follicle showed follicular mitotic figures with cytoplasmic halos. Early anagen hair follicles were apparently not treated effectively by ruby laser. CONCLUSION: Ruby laser leads to extensive follicular damage, and hair follicles considered to be at early anagen phase were not effectively treated. This may be the reason several courses of laser therapy are required to obtain satisfactory results.

Adult↗

PubMed1999

Enhanced lateral premotor activity during paradoxical gait in Parkinson's disease.

Parkinson's disease (PD) patients often show marked improvement of hypokinetic gait when exposed to special stimuli. To investigate physiological mechanisms underlying this "paradoxical gait" induced by visual cues in PD patients, we examined regional cerebral blood flow changes during gait on a treadmill guided by two different visual cues, the lines oriented transversely to the direction of walk (TL) and the lines parallel to it (PL). Ten PD patients and 10 age-matched controls received injections of 99mTc-hexamethylpropyleneamine oxime twice, once during each walking condition. Brain perfusion images were obtained by single-photon emission computed tomography. When affected by TL, PD patients showed marked improvement of gait parameters, mainly reduction of cadence. In regional cerebral blood flow analysis, when TL was compared with PL, both groups had common activation in the posterior parietal cortex and cerebellar hemispheres. Especially in the right lateral premotor cortex, PD patients showed enhanced activation induced by TL to a significantly greater degree than the controls. The present study indicates that the network dedicated to visuomotor control, particularly the lateral premotor cortex, plays an important role in the development of the paradoxical gait induced by special visual stimuli in PD patients.

Aged↗

PubMed1999

An infectious molecular clone of a Japanese genotype 1b hepatitis C virus.

We describe an infectious molecular clone of a Japanese genotype 1b strain of hepatitis C virus (HCV-N). The molecularly cloned sequence of HCV-N was compared with alignments of other HCV sequences, leading to the identification of 15 unique, nonconservative amino acid substitutions within the HCV-N open reading frame (ORF). These were repaired to the consensus genotype 1b residue, and the infectivity of RNA transcribed from the repaired clone was assessed by intrahepatic inoculation of a chimpanzee. Viral RNA was first detected in the serum of this chimpanzee 3 weeks following inoculation, and was intermittently present over the next 14 weeks. A strong and persistent anti-HCV serological response developed 13 weeks following inoculation, with seroconversion in the recombinant immunoblot assay (RIBA). A weaker, transient serological response, characterized by seroconversion in a third-generation enzyme-linked immunosorbent assay (ELISA) but not RIBA, occurred between weeks 1 and 5. This may have represented an anamnestic response to HCV antigens translated directly from the intrahepatically inoculated RNA, because the animal previously had undergone 2 unsuccessful attempts at rescue of HCV by intrahepatic RNA inoculation. There was neither biochemical nor histological evidence of liver disease. Although this is within the range of expected outcomes in an HCV-naive chimpanzee, prior immunologic priming may have modified the infection in this animal. The HCV-N clone is the first infectious molecular clone of HCV that is comprised entirely of genotype 1b sequence, and it contains an ORF sequence that is significantly divergent from that of a previously described genotype 1a/1b chimera.

3' Untranslated Regions↗

PubMed1999

Quasispecies of hepatitis C virus in serum and in three different parts of the liver of patients with chronic hepatitis.

Hepatitis C virus (HCV) has been known to infect hosts as a quasispecies. Several reports have shown this using serum samples, but there is little information about quasispecies in the liver. In this study, we evaluated quasispecies in serum and in 3 different parts of the liver in 8 patients with varying severity of chronic hepatitis C by calculating nucleotide diversity, entropy, type of substitution and by phylogenetic analysis. Nucleotide diversity of HCV was different in each sample and ranged from 0.37% +/- 0.31% to 4.10% +/- 1.06%. However, the degree of HCV diversity in serum correlated with that in the liver in each patient (P <.01). Common HCV clones were found both in serum and liver samples in all 6 noncirrhotic patients, but all serum clones were different from the clones from the 2 cirrhotic livers. Phylogenetic analysis showed that the degree of genetic diversity of HCV among the 3 liver samples was significantly high in the 4 patients with fibrosis. These genetic compartmentalizations of HCV did not depend on the type of substitution or the viral load of each liver sample. HCV quasispecies within the liver may be closely related to the viral life cycle and the pathogenesis of persistent infection of HCV.

Adult↗

PubMed1999

Exogenous IL-10 and IL-4 down-regulate IL-6 production by SLE-derived PBMC.

The elevated expression of IL-6 and IL-10 may have an important role in SLE pathogenesis. IL-6 production by normal monocytes can be inhibited by IL-10, and it has been suggested that SLE monocytes are refractory to this negative signal. To examine this possibility, the effects of regulatory factors on IL-6 expression by SLE PBMC (N = 51) were compared to effects on control PBMC (N = 21). We found that (1) exogenous rIL-10 and rIL-4 mediated reduction of constitutive and lectin-induced IL-6 in monocytes of SLE patients as effectively as that of controls; (2) IL-6 mRNA decay was significantly delayed in SLE with active disease (P < 0.001); (3) adding rIL-10 or neutralizing endogenous IL-1 beta and TNF-alpha down-regulated IL-6 mainly by destabilizing IL-6 transcripts, whereas exogenous IL-4 and TGF beta 1 down-regulated IL-6 transcriptionally; (4) time kinetics and levels of IL-10 were lower than those of IL-6 and IL-1 beta. Thus, contrary to a previous report, IL-6 production by SLE PBMC responds normally to regulatory signals, and the IL-6 overexpression in SLE may be due, at least in part, to the kinetics and availability of regulatory cytokines.

Adult↗

PubMed1999

Kinematic construction of the trajectory of sequential arm movements.

A kinematic construction rule determining the trajectory of human sequential movements is formulated using minimum-jerk and minimum-angular-jerk trajectories. The kinematic construction rule states that the observed trajectory of sequential movements coincides with a weighted average of the minimum-jerk trajectory and the segmented minimum-angular-jerk trajectory. This rule covers not only point-to-point movements but also simple sequential movements. Five kinds of experiments that measure the trajectories in planar, multijoint sequential arm movements were conducted. The measured trajectories coincide with the predictions made on the basis of the kinematic construction rule presented here. Moreover, predictions of previous models such as the minimum-jerk, the equilibrium-trajectory, and the minimum-torque-change models are shown to be incompatible with our observations of sequential movements.

Arm↗

PubMed1999

Nephrotic syndrome and end-stage renal disease with WT1 mutation detected at 3 years.

We report a boy who presented at 3 years with nephrotic syndrome and end-stage renal failure. Although histopathological findings showed end-stage kidney, isolated diffuse mesangial sclerosis (IDMS) was suspected because of his clinical course, and was confirmed by the presence of WT1 (Wilms tumor suppressor gene) mutation. He did not have ambiguous genitalia or Wilms tumor. The karyotype was 46:XY. A constitutional mutation in exon 7 (953G-->A, 312Arg-->Gin) was detected. A few cases of male IDMS, associated with WT1 mutations, have been reported. We believe that investigation for the WT1 mutation should be performed not only in Denys-Drash syndrome and IDMS, but also in end-stage renal disease with unexplained nephrotic syndrome of early onset. WT1 mutation-associated nephrotic syndrome has an increased risk of Wilms tumor. Careful ultrasound evaluations or bilateral nephrectomies are indicated.

Child, Preschool↗

PubMed1999

Levels of free prostate-specific antigen (PSA) can be selectively measured by heat treatment of serum: free/total-PSA ratios improve detection of prostate carcinoma.

We studied a simple heat treatment method for measuring free prostate-specific antigen (PSA). Samples were incubated at 56, 58, and 60 degrees C for 5, 15, 30, 45, and 60 min. Then, 1 ml samples were fractionated on a Sephacryl S-200 gel filtration column to separate alpha1-antichymotrypsin-complexed PSA (ACT-PSA) and free PSA. Values of ACT-PSA decreased with increasing incubation temperature and time, whereas free-PSA remained relatively constant. The optimal temperature and time for incubation were 58 degrees C and 30 min. Using free/total-PSA ratios, we were able to distinguish between benign prostatic hyperplasia and prostate carcinoma in patients whose PSA was in the diagnostic 'grey zone', i.e. 4.1 to 10.0 ng/ml. Through receiver operating characteristic curve analysis, the area under the curve increased from 0.675 to 0.871 when comparing the performance of total PSA to the free/total-PSA ratio. Thus, clinical application of our present methodology may reduce the need to obtain prostatic biopsies in patients whose PSA level is within the diagnostic 'grey zone'.

Chromatography, Gel↗