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Biomedical subjects

M Honda

Publications and source records attributed to M Honda.

At least 289 records · Page 16Linked to original sources
PubMed1997

Expression of Fas ligand and its receptor in cutaneous lupus: implication in tissue injury.

Fas ligand (FasL) is a type II membrane protein which belongs to the tumor necrosis factor family. Ligation of its receptor (Fas/APO-1/CD95) by FasL induces apoptosis of Fas-expressing cells. However, the in vivo function of these molecules in cutaneous immunity is presently unknown. In the present study, we investigated the involvement of Fas and FasL in the pathogenesis of cutaneous lupus by immunohistochemical methods. In normal skin, expression of Fas was observed on keratinocytes in the basal to granular layers. Unexpectedly, FasL was constitutively expressed on histiocytes in the dermis. In specimens of cutaneous lupus, Fas was expressed on infiltrating lymphocytes, as well as on keratinocytes as observed in normal skin. FasL was expressed on a portion of infiltrating CD4+ T cells and on histiocytes more frequently than those in normal skin. Double staining indicated that these FasL-expressing histiocytes were CD68 positive macrophages. Especially, FasL-expressing macrophages were distributed around appendages such as hair follicles. These results suggest the Fas/FasL interaction may be involved in the destruction of hair follicles which is a characteristic feature of cutaneous lupus.

Apoptosis↗
PubMed1997

Characterization of protein components of human urinary crystal surface binding substance.

We previously extracted crystal surface binding substance (CSBS) from human urine and showed that it appeared to constitute a substantial proportion of urinary macromolecular inhibitors of calcium oxalate crystallization. CSBS was isolated from human urine and fractionated by three consecutive chromatography procedures in order to characterize protein inhibitors of calcium oxalate crystallization. Sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and NH2-terminal amino acid sequencing revealed that inhibitory fractions eluted from a final, hydroxyapatite column contained prothrombin and osteopontin. Hydroxyapatite column fractions also contained other, unidentified protein inhibitors of calcium oxalate crystallization. CSBS contained also human serum albumin, alpha 1-acid glycoprotein, alpha 1-microglobulin, alpha 2-HS glycoprotein, retinol-binding protein, transferrin, and Tamm-Horsfall protein, but these proteins seemed to play no direct role in inhibitory activity.

Adult↗
PubMed1997

Precision of the gallbladder ejection fraction obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy as compared with the contraction ratio in three-dimensional computed tomography.

UNLABELLED: The gallbladder ejection fraction (GBEF) obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy has been used as a parameter of gallbladder function. To determine the accuracy of GBEF, the relationship with the contraction ratio of the gallbladder (GBCR) obtained with three-dimensional helical computed tomography (3D-CT) was studied. PATIENTS AND METHODS: A normal volunteer, 8 patients suffering from cholecystolithiasis and a patient with gallbladder dyskinesia were examined. The percent initial dose (%ID) for the gallbladder and GBEF with hepatobiliary scintigraphy were used to compare the volume of the gallbladder and GBCR which was measured by 3D-CT. RESULTS: The %ID of the gallbladder was correlated with the volume of the gallbladder by 3D-CT (Y = 1.000X - 1.818, r = 0.928). GBEF was correlated well with GBCR by 3D-CT (Y = 0.916X + 6.296, r = 0.975). CONCLUSIONS: The %ID of the gallbladder obtained with hepatobiliary scintigraphy may be a good indicator of the volume of the gallbladder. The accuracy of GBEF was confirmed by comparison with 3D-CT examination. GBEF is considered a useful parameter of pathophysiological gallbladder function.

Adult↗
PubMed1997

Pharmacokinetics of nicardipine enantiomers in healthy young volunteers.

OBJECTIVES: The present study was conducted to compare pharmacokinetic behaviors of nicardipine enantiomers given in different doses with different formulations of racemic nicardipine in healthy volunteers. METHODS: One or two 20-mg racemic nicardipine tablets, and a 40-mg sustained-release capsule of nicardipine were administered to eight healthy volunteers in a crossover fashion and pharmacokinetic parameters were evaluated. Enantiomer concentrations were determined by GC-MS combined with chiral stationary phase HPLC. RESULTS AND CONCLUSIONS: Serum concentration of (+)-nicardipine was approximately 2-3 times higher than that of (-)-nicardipine in 20- and 40-mg doses of conventional formulations and a non-linear increase in bioavailability with dose was demonstrated. The value for AUC of (+)-nicardipine was approximately 2.3-2.8 times greater than that of the (-)-nicardipine (P < 0.05) when 20 and 40 mg racemic nicardipine were administered in a conventional preparation. Relative bioavailability of the sustained-release preparation vs the conventional preparation was 28% and 44% for (+)- and (-)-nicardipine, respectively, for the 40-mg dose.

Administration, Oral↗
PubMed1997

Rapid identification of Smith-Lemli-Opitz syndrome homozygotes and heterozygotes (carriers) by measurement of deficient 7-dehydrocholesterol-delta 7-reductase activity in fibroblasts.

To extend the enzyme deficiency in Smith-Lemli-Opitz syndrome (SLOS) to extrahepatic tissues, 7-dehydrocholesterol-delta 7-reductase activity was measured in fibroblasts from 10 controls, five SLOS homozygotes, and five obligate heterozygotes. In cells grown almost to confluence in cholesterol-containing medium (4 mg/dL), the conversion of [1,2-3H]7-dehydrocholesterol to cholesterol (7-dehydrocholesterol-delta 7-reductase activity) was 3.8 times higher in control than in homozygote cells and 2.2 times higher than in heterozygote cells. After 24 hours' exposure of the fibroblasts to cholesterol-deficient medium supplemented with lovastatin, 7-dehydrocholesterol-delta 7-reductase activity increased twofold in controls, but did not change significantly in either heterozygous or homozygous cells. In contrast, the activities of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and lathosterol 5-dehydrogenase, two key enzymes that precede 7-dehydrocholesterol-delta 7-reductase in the cholesterol biosynthetic pathway, and low-density lipoprotein (LDL) receptor-mediated binding were equal in control, homozygote, and heterozygote fibroblasts. Further, HMG-CoA reductase activity and LDL receptor-mediated binding increased after exposure of the cells to cholesterol-deficient medium. Fibroblast cholesterol concentrations were approximately equal, although homozygote cells contained 30 times more 7-dehydrocholesterol. Thus, markedly reduced 7-dehydrocholesterol-delta 7-reductase activity that cannot be upregulated after exposure of the cells to cholesterol-deficient medium is diagnostic for the biochemical defect in SLOS. Significantly reduced enzyme activity between the levels in controls and homozygotes without accumulation of 7-dehydrocholesterol in fibroblasts identified heterozygotes.

Fibroblasts↗
PubMed1997

Estimate of physiological variability of peak latency in single sweep P300.

Among single sweep records of event-related potentials (ERPs), the peak latency of P300, which is one of the most prominent positive peaks in the ERP obtained in the oddball paradigm, may vary depending on the conditions of the subject. In the analysis of characteristics of the variability in the peak latency, it is important to know to what extent the variability of the measured peak latency (measured variability) is actually caused by physiological factors (physiological variability). In our previous study, a method was developed for judging whether the physiological variability really exists or not, and if it does exist, the developed method extracts the physiological variability from the measured variability based on a limited number of single sweep records. In the present study, based on the P300 waveforms which were detected by blinded visual inspection of the ERP data obtained by an auditory oddball paradigm from 12 healthy adults, the physiological variability was shown to exist with a confidence level of 95% for all subjects. Furthermore, its interval estimate was calculated by subtracting noise variability from the measured variability with a confidence level of 80%, and it was found to range from 17 to 57 ms for all subjects.

Adult↗
PubMed1997

Dissociation between contingent negative variation (CNV) and Bereitschaftspotential (BP) in patients with parkinsonism.

In order to clarify the generator mechanism of the late component of contingent negative variation (CNV), we compared the late CNV with Bereitschaftspotential (BP) in patients with parkinsonism (Parkinson's disease and progressive supranuclear palsy). In patients with mild symptoms (Hoehn Yahr grade I and II) both the late CNV and BP were clearly seen. In patients with severe symptoms (Hoehn Yahr grade III, IV and V) the BP was normally seen, but the late CNV was significantly smaller or absent (P < 0.001 at Cz) and it was also significantly smaller than that obtained from age-matched normals. In one patient (H-Y grade II) who had normal BP, the late CNV was diminished selectively at the midline area. Since it was reported that the late CNV arises from at least the supplementary motor area (SMA), selective diminution of the late CNV at the midline could be explained by the decreased activity of the SMA in parkinsonism. It was also previously reported that the BP was absent but the late CNV was normally present in a patient with cerebellar efferent lesion (Ikeda et al., 1994). Taken together with the experimental results indicating that movement-related neurons in the putamen behave contingent on external stimuli, it is suggested that subcortical generating mechanism is different for the late CNV and BP although both commonly share at least some cortical generators, and that the basal ganglia are most likely responsible for the generation of the late CNV and the cerebellar efferent system for the generation of the BP.

Adult↗
PubMed1997

Cortical mechanism underlying externally cued gait initiation studied by contingent negative variation.

In order to clarify the cortical mechanism underlying gait initiation, we examined the scalp distribution of the contingent negative variation (CNV) preceding externally cued gait initiation in a simple reaction-time paradigm in 10 healthy right-handed men, and compared the results with the CNV preceding simple foot dorsiflexion. A pair of auditory stimuli was given with an interstimulus (S1-S2) interval of 2 s and gait consisting of at least 3 steps was initiated with the right footstep as fast as possible in response to S2. Brisk dorsiflexion of the right foot was employed as a control task. It was found that the late CNV in the gait initiation task started about 1 s before S2, and was largest at Cz (-9.3 +/- 3.1 microV) without clear asymmetry over the scalp. However, it was ill defined in the parietal area. In the foot dorsiflexion task, the late CNV was maximal at Cz (-7.1 +/- 2.9 microV), and clearly seen also over the parietal area. The late CNV at Cz was significantly (P < 0.01) larger in the gait initiation than in the simple foot dorsiflexion. The amplitude of the late CNV preceding the foot dorsiflexion task was not significantly different between the sitting and the standing posture. In view of the results of previous invasive studies in both humans and animals which showed some frontal areas, including the supplementary motor area (SMA) and the primary motor cortex, as the generators of the late CNV, it is suggested that the cerebral cortex is active in initiation of externally triggered gait in a different way from the simple foot movement, and that bilateral SMAs may play a more important role in gait initiation than in simple foot movement.

Adolescent↗
PubMed1997

Experimental detection of canine haemoglobin (occult blood) in canine faeces by reversed passive latex agglutination.

A reversed passive latex agglutination test (RPLA) using anti-canine haemoglobin (Hb) antibody was developed for detecting bleeding in the lower digestive organs in dogs, and its applicability as a simple test for faecal occult blood was assessed. In Ouchterlony's gel immunodiffusion test, the anti-canine Hb antibody used to sensitize the latex reacted with canine Hb but not with Hbs, plasmas or meat extracts from pigs, goats, sheep, cattle, horses or chickens, or with fish extracts. Using latex sensitized with 50 micrograms/mg of anti-canine Hb IgG antibody, the lowest limit of detection for canine Hb was 21 micrograms/ml, and the latex reacted negatively with all test specimens other than canine Hb. In an in vitro experiment with a mixture of canine faeces and erythrocytes, the antigenicity of the Hb was found to undergo only very slight changes even when the specimens were allowed to stand for 12 h at room temperature. Hb could not be detected by RPLA in any of four successive faecal samples from three experimental dogs after infusion of autologous blood (5, 3 or 1 ml) into the stomach. In 3 other experimental dogs given an infusion of autologous blood (5, 3 or 1 ml) into the ascending colon, the presence of Hb was confirmed by RPLA in all four successive faecal samples obtained from those which received 5 or 3 ml of blood and in all except that obtained following the first defecation from the animal which had received 1 ml of blood.

Animals↗
PubMed1997

Glycosaminoglycans in crystal-surface binding substances and their role in calcium oxalate crystal growth.

OBJECTIVE: To clarify the role of glycosaminoglycans (GAGs) in crystal-surface binding substances (CSBS) on the growth of calcium oxalate crystals in urine. MATERIALS AND METHODS: Urine samples (24 h) were collected from healthy men (aged 25-42 years) and CSBS were obtained from the pooled urine samples. The CSBS were digested with heparitinase or proteinase and the inhibition of crystal growth assessed before and after enzyme digestion. Anion-exchange chromatography and high-performance liquid chromatography (HPLC) were used to determine the types of GAGs contained in the CSBS. RESULTS: The inhibitory activity of CSBS on crystal growth decreased with concentration when digested with heparitinase or proteinase. HPLC showed that CSBS contained a small amount of dermatan sulphate and abundant heparan sulphate, both of which inhibited crystal growth. CONCLUSION: Both heparan sulphate and dermatan sulphate may inhibit calcium oxalate crystallization, the former being the predominant GAG in CSBS.

Adult↗
PubMed1997

Event-related potentials associated with judgment: comparison of S1- and S2-choice conditions in a contingent negative variation (CNV) paradigm.

To elucidate the functional role of association cortex in judgment and decision-making about external stimuli, the scalp topography of contingent negative variation (CNV) recorded in 9 normal volunteers was compared in two settings; dichotomous S1- and S2-choice paradigms using right wrist extension or flexion movement upon S2 as the choice reaction task with an S1-S2 interstimulus interval of 2 s. Two main findings were obtained. First, early CNV in the S1-choice paradigm consisted of a frontal to frontopolar midline negative potential, most likely representing judgment more than orienting response, and a left-sided parietal positive potential, at least partially representing P3b, whereas in the S2-choice paradigm it consisted only of a smaller frontal negative potential shift, most likely representing merely an orienting response. This suggests that the prefrontal and left parietal association cortexes might be active in the judgment and decision-making process. Second, after S2, two positive peaks (334 and 545 ms after S2) were observed at the midline central to left parietal areas only in the S2-choice paradigm. In the S1-choice paradigm, one large negative peak (275 ms after S2) was observed. We postulate that the first peak of the S2-choice paradigm is related to decision making or judgment and that the second peak is related to the following cognitive process. We conclude that at least the prefrontal and parietal association cortexes generate transient potentials accompanying judgment, and possibly decision making.

Adult↗
PubMed1997

Nucleotide sequence variation of human T-lymphotropic virus type II in Vietnam.

A high rate of human T-lymphotropic virus type II (HTLV-II) infection has been documented in intravenous drug abusers (IVDAs) in South Vietnam. We have investigated the molecular characteristics of the virus and have shown that one HTLV-II subtype is predominant in Ho Chi Minh City. This molecular subtype, HTLV-IIb, was identified in a number of South Vietnamese by nucleotide sequence analysis of the long terminal repeat (LTR) region. HTLV-IIa was not found. These findings suggest that HTLV-IIb is endemic in IVDAs in South Vietnam, although IVDAs in urban areas in North America are predominantly infected with HTLV-IIa.

Adult↗
PubMed1997

Alpha-delta sleep in a case with non-24 h sleep-wake syndrome: quantitative electroencephalogram analysis of alpha and delta band waves.

Four all-night polysomnograms of a 39-year-old male patient with non-24 h sleep-wake syndrome were recorded. We analysed electroencephalograms (EEG) with the power spectrum method and the wave pattern recognition analysis of Fujimori. The EEG of the rest waking condition showed normal patterns. High-voltage diffuse alpha band waves were observed in sleep stages 2, 3 and 4. The integrated area of the alpha band waves in the analysis epochs showed a strong positive correlation to the delta band components in the power spectrum of the same epoch during sleep (correlation coefficients r = 0.762-0.815). Alpha band waves during sleep were clearly different from the alpha waves in the rest waking condition, with respect to slower peak frequency and the frontal dominant voltage distribution.

Adult↗
PubMed1997

[Colonization types of Escherichia coli in experimental urinary tract infection in compromised mice treated with hydrocortisone].

We studied the experimental urinary tract infections (UTIs) on compromised mice with Escherichia coli to elucidate the effects of three factors (bacterial strains, doses of hydrocortisone, infectious periods) on the bacterial colonization in the bladders. We selected three strains from the stock of E. coli isolated from the urine or feces of patients with lower UTI, because each of the three strains showed a tendency in colonization in previous experiments: One strain, which was named H70, showed a relative slight and intracellular colonization; the H99, an extracellular and the K88, both intracellular and extracellular growths which were large. The rate of bacterial microscopic recovery from the bladders of mice inoculated strains H70, H99 and K88 were 25.0, 41.7 and 79.2% respectively. And the recovery from the mice inoculated cortisone, 0, 2, 4 and 8 mg/mouse were 38.9, 55.6, 55.6 and 44.4% respectively. The detections of various colonizations at 3, 6 and 24 hr after the bacterial inoculation were that extracellular types were 45.8, 20.8 and 20.8%, intracellular types were 4.2, 16.7 and 12.5%, simultaneous colonizations were 4.2, 16.7 and 4.2% and the detections of at least one of them were 54.2, 54.2 and 37.5% respectively. Thus, the global findings were that extracellular growth of the bacteria were predominant at first, then the bacteria invaded the mucosal cells and the intracellular bacteria stayed after the voiding of extracellular bacteria. Intracellular colonizations seemed more strongly interacting with hosts than extracellular types, because cortisone enhanced the intracellular colonizations more strongly than the others. However, it seemed that urinary tract infections were not simple events but the results of the interactions of the bacterial strains and hosts, because the locations and degrees of the bacterial colonization and the effects of hydrocortisone on them were different in each bacterial strain and infectious period.

Animals↗