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Biomedical subjects

M Honda

Publications and source records attributed to M Honda.

At least 271 records · Page 15Linked to original sources
PubMed1998

Immunohistological study in sixteen children with acute tubulointerstitial nephritis.

Sixteen children (7 boys and 9 girls, aged 1.9 to 14.8 years) diagnosed with acute tubulointerstitial nephritis [ATIN: 4 drug-induced, 6 infection, 2 tubulointerstitial nephritis and uveitis syndrome (TINU), and 4 unclassified] were studied to characterize the nature of the interstitial mononuclear cells involved in each clinical picture of the disease Six children with asymptomatic microscopic hematuria whose histology was a minimal change in renal biopsy were studied as controls. The enzyme immunoassay was carried out using the biopsy specimen obtained from 4 to 42 days after the onset of illness. In ATIN, the number of renal interstitial infiltrating CD3, CD4, and CD8 T lymphocytes, respectively, was significant larger than that in the minimal change kidneys [CD3 T cells; median 94 (range 3.2-330)/mm2 interstitial area vs. median 7.8 (range 1.1-23), p = 0.003, CD4 T cells; 11 (range 0.5-78) vs. 1.5 (range 0-7.7), p = 0.018, CD8 T cells; 22 (range 1.0-150) vs. 2.9 (range 0-14), p = 0.047]. In addition, a positive correlation was found between the CD3 and CD4 T cells. On the other hand, in regard to the relationship between the CD3 and CD8 T cells, CD8/CD3 was extremely low in 3 cases in the infection-induced group, but the other 3 groups included no extremely low CD8/CD3 cases. Although interstitial monocytes/macrophages were smaller than the T lymphocytes in number, a positive correlation was revealed between the T lymphocytes and monocytes/macrophages (CD3 T cells vs. monocytes/macrophages; r = 0.53, p = 0.039). No relationship was found between the duration from the onset of illness to renal biopsy and mononuclear cell involvement. These findings suggest that cellular immunity, mainly T lymphocytes, may play a role in the pathogenesis of ATIN in children.

Acute Disease↗
PubMed1998

[A case of autosomal dominant, pure form spastic paraplegia with thinning of the corpus callosum].

Autosomal dominant hereditary spastic paraplegia (HSP) is genetically classified into three types, all of which are characterized by insidiously progressive spasticity of the lower extremities. Patients with a complicated form of autosomal recessive HSP associated with hypoplasia of the corpus callosum have been reported by Iwabuchi et al. Here we report a 64-year-old patient with a pure form of autosomal dominant HSP with thinning of the corpus callosum. He had been well until 12 years of age, when spasticity and weakness of the lower extremities began to develop. His symptoms gradually worsened and he had difficulty in walking at the age of 44. When he was 56 years old, he visited our hospital. Eleven family members over five generations have been affected, and anticipation, i.e., an apparent decrease in age of onset, has been observed. On admission, he had mild cataracts, equinovarus and pes cavus, and neurological examination revealed spastic paraplegia. However, the intelligence test was normal, and nystagmus, ataxia of the extremities, involuntary movement, orthostatic hypotension or urinary disturbance was not observed. Trinucleotide repeat diseases, such as Huntington's disease, spinocerebellar ataxia type 1, spinocerebellar ataxia type 2, Machado-Joseph disease and dentatorubral-pallidoluysian atrophy, were excluded by DNA analysis. Brain MRI at the age of 64 revealed marked thinning of the corpus callosum. We considered this patient had a pure form of HSP. However, thinning of the corpus callosum has never been reported in autosomal dominant HSP.

Adolescent↗
PubMed1998

Vertical transmission of human immunodeficiency virus type 1 in Japan, 1989-1997: presence of two subtypes B and E with subtype E predominance. National Cooperative Study Investigators on Vertical Transmission of HIV-1.

A collaborative group for studying vertical transmission of human immunodeficiency virus (HIV)-1 in pregnant women and their babies was established in Japan in 1989. Forty-two infants, including 13 HIV-1-infected, 25 uninfected and four of undetermined status and 15 control children born to HIV-1 negative mothers were diagnosed and followed from birth to 1.5 years. All strains from HIV-positive infants were either clade E (eight infants, 61.5%) or B (five infants, 38.5%) according to DNA sequencing specific for the HIV-1 C2-V3 region. The 42 mothers with HIV-1 were women with sexual-risk behavior from all regions, but were concentrated in the Kanto District. In this group of HIV-infected children, there was no significant difference between the transmissibility of their mother's clade E and B viruses. Eight (61.5%) of the 13 virus-infected babies were Japanese and five (62.5%) of the eight were positive for HIV-1 clade E. The V3 loop region of the clade E virus of the babies was conserved but approximately 60% of the sequences which showed a substitution of aspartic acid by asparagine at position 29. The results suggest that HIV-1 clade E may be predominant in vertical transmissions and are phenotypically different from HIV-1 in persons with various other risk behaviors in Japan.

Consensus Sequence↗
PubMed1998

Alteration of the GABAergic neuronal system of the retina and superior colliculus in streptozotocin-induced diabetic rat.

Diabetes mellitus (DM) often causes neural dysfunctions, including visual disorders. To investigate the effect of hyperglycemia on the visual system, we studied the metabolism of gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter that has an important role in visual functions. We determined the GABA content and activities of glutamate decarboxylase (GAD) and GABA transaminase (GABA-T) in the retina and superior colliculus (SC) in streptozotocin (STZ)-induced DM rats. The GABA content and activities of GAD and GABA-T were decreased in the retinas of STZ-treated rats. The GABA content and GAD activity were reduced in the SC of STZ-treated rats, whereas GABA-T activity showed no marked change. This GABA reduction in the diabetes may be correlated with visual dysfunctions.

4-Aminobutyrate Transaminase↗
PubMed1998

[Standard versus long-term prednisolone with sairei-to for initial therapy in childhood steroid-responsive nephrotic syndrome: a prospective controlled study].

The most appropriate initial treatment for children with steroid-responsive nephrotic syndrome is controversial. Initial treatment with 18-week prednisolone and the Chinese herbal medicine. Sairei-to, may prevent subsequent relapse. To determine whether similar results can be obtained with a combination of just initial 8-week prednisolone and Sairei-to, we compared the effects of such treatment with those of treatment with 18-week prednisolone and Sairei-to in 196 children with steroid-responsive nephrotic syndrome. The patients were randomly assigned to receive 8-week (group 1) or 18-week (group 2) prednisolone for the initial therapy. All patients received Sairei-to for 2 years in addition to prednisolone. Eighty-eight of the 98 patients in group 1 and 83 of the 98 patients in group 2 completed their trial. At entry, the two groups of patients did not differ in their clinical and laboratory findings. During the 2-year trial, 62 group 1 patients (70%) and 54 group 2 patients (65%) had relapses, and 19 group 1 patients (21%) and 20 group 2 patients (24%) had frequent relapses. The present study demonstrates that a combination of initial 8-week prednisolone and 2-year Sairei-to is effective in children with steroid-responsive nephrotic syndrome.

Anti-Inflammatory Agents↗
PubMed1997

Serum concentration of type I collagen metabolites as a quantitative marker of bone metastases in patients with prostate carcinoma.

BACKGROUND: Bone scans, widely used for the detection of bone metastases from prostate carcinoma, can neither quantitate metastatic lesions nor detect osteolytic lesions. METHODS: Serum concentrations of the carboxyterminal propeptide of Type I procollagen (PICP), the carboxyterminal pyridinoline cross-linked telopeptide of Type I collagen (ICTP), and prostate specific antigen (PSA) were measured by radioimmunoassays in 48 patients with benign prostatic hyperplasia (BPH), 25 patients with prostate carcinoma (PCA) without bone metastases, and 36 patients with PCA and bone metastases. RESULTS: Serum concentrations of PICP were significantly higher in patients with PCA with bone metastases than in patients with BPH or PCA without bone metastases. No significant differences were observed between patients with BPH and those with PCA without bone metastases. Serum ICTP concentrations were significantly higher in patients with PCA than in patients with BPH regardless of the presence or absence of bone metastases. Serum concentrations of PICP, ICTP, and PSA correlated significantly with Soloway's grading system for bone scans. The serum concentrations of PICP and ICTP in patients without bone metastases showed a significant downward trend in response to antiandrogen therapy. CONCLUSIONS: These observations suggest that the serum concentrations of PICP and ICTP are quantitative markers of bone metastases from PCA when followed serially in individual patients.

Age Factors↗
PubMed1997

Functional relevance of cross-modal plasticity in blind humans.

Functional imaging studies of people who were blind from an early age have revealed that their primary visual cortex can be activated by Braille reading and other tactile discrimination tasks. Other studies have also shown that visual cortical areas can be activated by somatosensory input in blind subjects but not those with sight. The significance of this cross-modal plasticity is unclear, however, as it is not known whether the visual cortex can process somatosensory information in a functionally relevant way. To address this issue, we used transcranial magnetic stimulation to disrupt the function of different cortical areas in people who were blind from an early age as they identified Braille or embossed Roman letters. Transient stimulation of the occipital (visual) cortex induced errors in both tasks and distorted the tactile perceptions of blind subjects. In contrast, occipital stimulation had no effect on tactile performance in normal-sighted subjects, whereas similar stimulation is known to disrupt their visual performance. We conclude that blindness from an early age can cause the visual cortex to be recruited to a role in somatosensory processing. We propose that this cross-modal plasticity may account in part for the superior tactile perceptual abilities of blind subjects.

Adult↗
PubMed1997

Serial lectin affinity chromatography with concavalin A and wheat germ agglutinin demonstrates altered asparagine-linked sugar-chain structures of prostatic acid phosphatase in human prostate carcinoma.

Differences between human prostate carcinoma (PCA, five cases) and benign prostatic hyperplasia (BPH, five cases) in asparagine-linked (Asn) sugar-chain structure of prostatic acid phosphatase (PAP) were investigated using lectin affinity chromatography with concanavalin A (Con A) and wheat germ agglutinin (WGA). PAP activities were significantly decreased in PCA-derived PAP, while no significant differences between the two PAP preparations were observed in the enzymatic properties (Michaelis-Menten value, optimal pH, thermal stability, and inhibition study). In these PAP preparations, all activities were found only in the fractions which bound strongly to the Con A column and were undetectable in the Con A unbound fractions and in the fractions which bound weakly to the Con A column. The relative amounts of PAP which bound strongly to the Con A column but passed through the WGA column, were significantly greater in BPH-derived PAP than in PCA-derived PAP. In contrast, the relative amounts of PAP which bound strongly to the Con A column and bound to the WGA column, were significantly greater in PCA-derived PAP than in BPH-derived PAP. The findings suggest that Asn-linked sugar-chain structures are altered during oncogenesis in human prostate and also suggest that studies of qualitative differences of sugar-chain structures of PAP might lead to a useful diagnostic tool for PCA.

Acid Phosphatase↗
PubMed1997

Catalytic activity of the alpha3beta3gamma complex of F1-ATPase without noncatalytic nucleotide binding site.

A mutant alpha3beta3gamma complex of F1-ATPase from thermophilic Bacillus PS3 was generated in which noncatalytic nucleotide binding sites lost their ability to bind nucleotides. It hydrolyzed ATP at an initial rate with cooperative kinetics (Km(1), 4 microM; Km(2), 135 microM) similar to the wild-type complex. However, the initial rate decayed rapidly to an inactivated form. Since the inactivated mutant complex contained 1.5 mol of ADP/mol of complex, this inactivation seemed to be caused by entrapping inhibitory MgADP in a catalytic site. Indeed, the mutant complex was nearly completely inactivated by a 10 min prior incubation with equimolar MgADP. Analysis of the progress of inactivation after initiation of ATP hydrolysis as a function of ATP concentration indicated that the inactivation was optimal at ATP concentrations in the range of Km(1). In the presence of ATP, the wild-type complex dissociated the inhibitory [3H]ADP preloaded onto a catalytic site whereas the mutant complex did not. Lauryl dimethylamineoxide promoted release of preloaded inhibitory [3H]ADP in an ATP-dependent manner and partly restored the activity of the inactivated mutant complex. Addition of ATP promoted single-site hydrolysis of 2',3'-O-(2,4,6-trinitrophenyl)-ATP preloaded at a single catalytic site of the mutant complex. These results indicate that intact noncatalytic sites are essential for continuous catalytic turnover of the F1-ATPase but are not essential for catalytic cooperativity of F1-ATPase observed at ATP concentrations below approximately 300 microM.

Adenosine Diphosphate↗
PubMed1997

A role for macrophage scavenger receptors in atherosclerosis and susceptibility to infection.

Macrophage type-I and type-II class-A scavenger receptors (MSR-A) are implicated in the pathological deposition of cholesterol during atherogenesis as a result of receptor-mediated uptake of modified low-density lipoproteins (mLDL). MSR-A can bind an extraordinarily wide range of ligands, including bacterial pathogens, and also mediates cation-independent macrophage adhesion in vitro. Here we show that targeted disruption of the MSR-A gene in mice results in a reduction in the size of atherosclerotic lesions in an animal deficient in apolipoprotein E. Macrophages from MSR-A-deficient mice show a marked decrease in mLDL uptake in vitro, whereas mLDL clearance from plasma occurs at a normal rate, indicating that there may be alternative mechanisms for removing mLDL from the circulation. In addition, MSR-A-knockout mice show an increased susceptibility to infection with Listeria monocytogenes or herpes simplex virus type-1, indicating that MSR-A may play a part in host defence against pathogens.

Animals↗
PubMed1997

Movement-related cortical potentials and regional cerebral blood flow change in patients with stroke after motor recovery.

We investigated brain activity during the self-initiated, simple, repetitive hand movement in two patients with hemiparesis due to stroke, who showed relatively good motor recovery, using movement-related cortical potential (MRCP) and regional cerebral blood flow (rCBF) measurements with positron emission tomography (PET). One patient had cortical lesions in the left premotor and left parietal cortices due to cerebral thrombosis, and the other had lesions in the right Rolandic area and several subcortical areas due to the occlusion of the right internal carotid artery. MRCPs in both patients showed lack of the contralateral predominance in amplitude of the late component of slow negative shift prior to the movement of the recovered hand. PET activation study showed increased rCBF in the ipsilateral hemisphere during the movement of the recovered hand. These findings suggest that the ipsilateral hemisphere to the recovered hand may play an important role in the process of motor recovery in patients with cortical infarction, especially within the time period of several hundred ms before the onset of each movement.

Aged↗
PubMed1997

Correlation of titer of antibody to principal neutralizing domain of HIVMN strain with disease progression in Japanese hemophiliacs seropositive for HIV type 1.

With the use of the principal neutralizing determinant (PND) peptide-based ELISA to measure anti-PND antibodies that specifically bound synthetic peptides derived from HIVIIIB, HIVMN, HIVRF, HIVSC, HIVWJM-2, HIVAf1l.con, or HIVAf2.con, type-specific antibodies to the HIVMN peptide were studied in 350 serum specimens from Japanese with hemophilia A who had been injected with known unheated factor VIII concentrates until 1985 and had been infected with HIV-1 subtype B. These antibodies were not found in any of the seronegative sera of hemophiliacs, patients with autoimmune diseases, or normal healthy controls. Further, all hemophiliacs rapidly progressing to AIDS and death among the 95 hemophiliacs in a restricted Nara area had antibody titers of less than 20 and their low levels preceded the rapid progression to the disease state. In contrast, slowly progressing hemophiliacs maintained an antibody titer of more than 100 from the initial stages of viral infection and remained asymptomatic. Sequence analysis of the V3 regions of HIV-1 indicated that the hemophiliacs who maintained a high anti-PNDMN antibody level showed a conserved MN sequence. In contrast, the HIV-infected hemophiliacs with nonreactivity in the ELISA showed sequence changes in the neutralizing epitopes of HIVMN. The dynamic of the serum anti-PNDMN antibody titer appear to be a characteristic indicator of the progression of the HIV-infected status in Japanese hemophiliacs seropositive for HIV-1.

Adult↗
PubMed1997

Sterol concentrations in cultured Smith-Lemli-Opitz syndrome skin fibroblasts: diagnosis of a biochemically atypical case of the syndrome.

The Smith-Lemli-Opitz syndrome is a common birth defect syndrome caused by a deficiency of 7-dehydrocholesterol delta 7-reductase, an essential enzyme in the biosynthesis of cholesterol. The syndrome can usually be diagnosed easily from the plasma markers of markedly elevated 7-dehydrocholesterol and reduced cholesterol concentrations. However, atypical cases with normal plasma levels of cholesterol with only moderately elevated 7-dehydrocholesterol have been reported. To establish a sensitive method for the biochemical diagnosis of the atypical cases of the syndrome, we measured sterol concentrations of cultured skin fibroblasts. 7-Dehydrocholesterol concentrations in patients' fibroblasts grown in the presence of 10% fetal bovine serum were significantly higher than those in controls and parents (P < 0.0005), but they were not elevated proportionately as much as in plasma. To re-produce the accumulation of 7-dehydrocholesterol, the cells were exposed to delipidated medium to induce sterol biosynthesis. After 4 weeks, 7-dehydrocholesterol concentrations in patients' fibroblasts increased from 2.8 +/- 0.3% to 34 +/- 3% of total sterols (cholesterol + 7-dehydrocholesterol + 8-dehydrocholesterol). The increase was also observed in fibroblasts from an atypical patient who has a normal plasma cholesterol level and a 7-dehydrocholesterol concentration of only 0.15 mg/dl. In contrast, cells from parents and controls accumulated very little 7-dehydrocholesterol (< 1% of total sterols). These results demonstrate that cultured fibroblasts exhibit abnormally high accumulation of 7-dehydrocholesterol after cells are exposed to delipidated medium not only in typical patients, but also in an atypical case. The present method is a sensitive procedure for the biochemical diagnosis of this syndrome.

Adolescent↗
PubMed1997

Imidase, a dihydropyrimidinase-like enzyme involved in the metabolism of cyclic imides.

Imidase, which preferably hydrolyzed cyclic imides to monoamidated dicarboxylates, was purified to homogeneity from a cell-free extract of Blastobacter sp. A17p-4. Cyclic imides are known to be hydrolyzed by mammalian dihydropyrimidinases. However, imidase was quite different from known dihydropyrimidinases in structure and substrate specificity. The enzyme has a relative molecular mass of 105 000 and consists of three identical subunits. The purified enzyme showed higher activity and affinity toward cyclic imides, such as succinimide (Km = 0.94 mM; Vmax = 910 micromol x min(-1) x mg(-1)), glutarimide (Km = 4.5 mM; Vmax = 1000 micromol min (-1) x mg (-1) and maleimide (Km = 0.34 mM; Vmax = 5800 micromol x min(-1)x mg(-1)), than toward cyclic ureides, which are the substrates of dihydropyrimidinases, such as dihydrouracil and hydantoin. Sulfur-containing cyclic imides, such as 2,4-thiazolidinedione and rhodanine, were also hydrolyzed. The enzyme catalyzed the reverse reaction, cyclization, but with much lower activity and affinity. The enzyme was non-competitively inhibited by succinate, which was found to be a key compound in cyclic-imide transformation in relation with the tricarboxylic acid cycle in this bacterium, suggesting that the role of imidase is to catalyze the initial step of cyclic-imide degradation.

Amidohydrolases↗
PubMed1997

Hepatocytic phenotypes induced in sarcomatous cholangiocarcinoma cells treated with 5-azacytidine.

The sarcomatoid cells found in cholangiocarcinoma (CC) or hepatocellular carcinoma (HCC) are not well characterized. In this study, a human sarcomatoid CC cell line, ETK-1, was established from a patient, and then morphological and phenotypical characteristics of the ETK-1 cells were evaluated before and after treatment with differentiation-inducing 5-azacytidine (5-azaCR). Phenotypically, the ETK-1 cells appeared immature. Exposure to 5-azaCR induced morphological transformation; a converted cell line, MEK, was successfully established. The MEK cells expressed such hepatocyte-specific proteins as alpha-fetoprotein, albumin, integrin alpha1, and thrombopoietin, but lost such bile duct-specific proteins as integrin alpha3 and integrin beta4. The histopathology of MEK xenografts resembled that of HCC. The ETK-1 cells appeared to be converted into hepatocytes by exposure to 5-azaCR. On the other hand, ETK-1 xenografts were diagnosed as tubular adenocarcinoma, and the tumor cells had a ductal phenotype. This suggests the possibility that ETK-1 cells can differentiate along a biliary epithelial cell lineage. ETK-1 and MEK will be useful in studying hepatocytic differentiation and the transformation from a biliary epithelial cell to a hepatocytic lineage.

Animals↗