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Biomedical subjects

M Kawamoto

Publications and source records attributed to M Kawamoto.

At least 73 records · Page 4Linked to original sources
PubMed1998

Dissociation of adrenomedullin concentrations in plasma and cerebrospinal fluid in pregnant and non-pregnant women.

Adrenomedullin (AM), a potent vasodilator peptide, has been shown to act within the central nervous system to modulate fluid and electrolyte balance. AM-immunoreactive cells have been found in the anterior pituitary gland and the choroid plexus of humans. In addition, AM activity has been implicated in the regulation of maternal circulation during pregnancy. To determine the relationship between AM concentration in the cerebrospinal fluid (CSF) and plasma, we measured AM levels in CSF and plasma of pregnant (group P, n = 12) and non-pregnant (group NP, n = 10) women scheduled to undergo gynecologic or obstetric surgery. In both groups, the concentration of AM in the plasma exceeded that in the CSF. Plasma AM concentration was significantly higher in pregnant than non-pregnant women (17.3+/-5.8 vs 5.1+/-1.4 pmol/l, mean +/- S.D.; P<0.01), whereas CSF AM concentration did not differ between the two groups (1.3+/-0.9 and 0.9+/-0.4 pmol/l in groups P and NP respectively). No significant correlation was found between AM concentrations in the CSF and plasma. The present findings suggest that AM is present in the CSF and that its concentration in the CSF is regulated independently from that in the plasma.

Adrenomedullin↗
PubMed1998

Continuous monitoring of jugular bulb venous oxygen saturation for evaluation of cerebral perfusion during carotid endarterectomy.

In this study we examined whether continuous monitoring of jugular bulb venous oxygen saturation (SjO2) is applicable for the evaluation of cerebral hypoperfusion during carotid endarterectomy (CEA). The subjects were 25 patients who underwent elective CEA under general anaesthesia. After the carotid stump pressure (SP) was measured, SjO2 and the somatosensory evoked potentials (SEP) were monitored during the carotid test clamping for 10 min. There was no alteration in cardiovascular and respiratory status during the test clamping. No correlation was observed between SEP amplitude and SP (r = 0.16, p = 0.25). However, at clamping, SjO2 decreased from 70 to 64% (p < 0.01) with a reduction in SEP amplitude from 2.0 to 1.6 microV (p < 0.01). After declamping, SjO2 increased from 65 to 70% (p < 0.01) with a recovery in SEP from 1.6 to 1.9 microV (p < 0.01). The changes in SEP amplitude and SjO2 correlated (r = 0.66, p < 0.001). These results suggest that continuous monitoring of SjO2 is superior to SP measurement in the prediction of cerebral hypoperfusion caused by carotid clamping and applicable to CEA.

Cerebrovascular Circulation↗
PubMed1997

Human brain potentials observed using the line-motion method: the neurophysiological correlates of visual illusory motion perception.

This study shows the temporal dynamics of neurophysiological activities in illusory motion perception. Event-related brain potentials were recorded from 12 healthy subjects while they performed a two-alternative (motion/no motion), forced-choice task using the line motion method. Amplitudes of a late positive component at Fz, Cz, Pz, O1 and O2 increased as cue lead time (CLT) increased. At a CLT of 50 ms, the amplitudes of the late positive component (the peak latency at O1, O2: 310 ms; Fz, Cz, Pz: 360-390 ms) observed during illusory motion perception was larger than that observed during no motion perception, even though the physical stimuli were the same. These results suggest that the perception of illusory motion correlates to a relatively late stage of visual information processing.

Adult↗
PubMed1997

CD4+ hepatic cancer-specific cytotoxic T lymphocytes in patients with hepatocellular carcinoma.

We investigated T cell immunity against hepatocellular carcinoma (HCC), and showed that both peripheral blood mononuclear cells and tumor-infiltrating lymphocytes incubated with interleukin-2 alone displayed HLA-nonrestricted but hepatic cancer-specific cytotoxicity in a majority of patients with HCC. Namely, they lysed both HCC and cholangiocellular carcinomas in an HLA-nonrestricted manner, but they did not lyse any tumors with the other histological types tested, normal hepatocytes, or the cells transfected with hepatitis C virus or MUC1 gene. These CTL lines and clones were phenotypically CD3+CD4+CD8-. These unique CTL could play important roles in T cell immunity against HCC.

CD4-Positive T-Lymphocytes↗
PubMed1997

Pithedulosides A-G, oleanane glycosides from Pithecellobium dulce.

Seven saponins named pithedulosides A-G were isolated from the seeds of Pithecellobium dulce. Their structures were established through spectral analyses as echinocystic acid 3-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside, echinocystic acid and oleanolic acid 3-O-alpha-L-arabinopyranosyl- (1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosides and 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl -(1-->6)-beta-D-glucopyranosides, oleanolic acid 3-O-alpha-L-arabinopyranosy-(1-->2)-alpha-L- arabinopyranosyl-(1-->6)-[beta-D-glucopyranosyl-(1-->2)]-beta- D-glucopyranoside, and 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->2)]--beta-D-glucopyranoside.

Carbohydrate Sequence↗
PubMed1997

Selective migration of alpha-smooth muscle actin-positive myofibroblasts toward fibronectin in the Boyden's blindwell chamber.

1. In order to address the hypothesis that migrating fibroblasts have a different phenotype, human fetal lung fibroblasts (HFL-1) cells were evaluated in the Boyden blindwell chamber migration assay followed by immunoelectron microscopy. 2. HFL-1 cells were placed on nucleopore filters and incubated for 2 h using purified human plasma fibronectin (pFn) as a chemoattractant. Filters were then processed for immunoelectron microscopy using antibodies for alpha-smooth muscle (alpha-SM) actin as a marker for myofibroblasts, cellular fibronectin (cFn) and VLA-5. 3. Cells which had migrated to the bottom side of the filter were more likely to express alpha-SM actin, 29.1 +/- 3.4% of cells, compared with cells which did not migrate through the filter, 12.4 +/- 1.3% (P < 0.05). The total proportion of alpha-SM-actin-positive cells located on both sides of the filter showed no difference between those which had migrated toward pFn and controls (17.7 +/- 1.0% compared with 20.2 +/- 2.5%). 4. cFn-positive cells showed minimal differences compared with control cells, while perinuclear and endoplasmic reticulum staining of VLA-5 was observed only in the cells treated with pFn. 5. The results show that HFL-1 cells are heterogenous for alpha-SM actin expression. Short-term incubation with pFn did not change the proportion of alpha-SM-actin-positive HFL-1 cells. Cells which migrate, however, are enriched for alpha-SM actin expression. pFn-induced fibroblast chemotaxis can selectively recruit myofibroblasts with increased alpha-SM actin expression, a feature which may contribute to the altered population of cells at sites of fibrosis.

Actins↗
PubMed1997

Non-restricted T cell receptor (TCR)-V alpha and -V beta gene usage in patients with pulmonary sarcoidosis.

Sarcoidosis is a systemic granulomatous disease of unknown etiology characterized by the pronounced accumulation of CD4+ T cells and macrophages in the affected organs. TCR variable (V) alpha and V beta gene usage in patients with sarcoidosis is still a matter of discussion. In this investigation, we analysed TCR-V alpha and -V beta gene usage in bronchoalveolar lavage fluid (BALF) and peripheral blood mononuclear cells (PBMC) of 30 patients with active pulmonary sarcoidosis using an adapter ligation method, reverse transcriptase-polymerase chain reaction (RT-PCR), and sequence-specific oligonucleotide probe (SSOP) analyses. There was no significant difference in TCR-V alpha or -V beta gene usage between BALF (n = 12) or PBMC (n = 27) of patients and PBMC of healthy subjects (n = 10). Neither selective TCR-V alpha nor -V beta expansion was observed in the paired BALF and PBMC from seven of nine patients. However, selective expansions were observed in a few TCR-V alpha or -V beta subsets in the BALF or PBMC of some individuals. Although a modest increase in a few TCR-V alpha or -V beta subsets was observed in the BALF or PBMC of some individuals, the increased TCR-V alpha or -V beta subsets were not closely associated with the HLA-DRB1, DQA1, DQB1, and DPB1 alleles of these patients. These results suggest that TCR-V alpha or -V beta gene usage is not restricted in both lung and peripheral blood in the majority of patients with active pulmonary sarcoidosis.

Adult↗
PubMed1997

Detection of MAGE-4 protein in sera of lung cancer patients.

We investigated the level of MAGE-4 protein in sera of patients with primary lung cancer to understand better the biological roles of the MAGE proteins. MAGE-4 protein was detected as a non-degraded form in both the supernatant of a MAGE-4+ tumor cell line and in a patient's serum. Serum level of the MAGE-4 protein in lung cancer patients (n=100, mean=1.17 ng/ml) was significantly higher than that in either patients with benign pulmonary diseases (n=80, 0.33 ng/ml) or healthy donors (n=68, 0.32 ng/ml). It was higher than the cutoff level (1.15 ng/ml) in 34 of 100 cancer patients, but not in anyone in the other groups.

Adult↗
PubMed1997

[CT-assisted measurement of total and regional volumes of pneumatization in the temporal bone].

The total volume of air cells in the temporal bone and the regional volumes (tympanic cavity, petrous apex and mastoid antrum) were measured by using a system which we developed for the measurement of air cells by computerized digital processing of high-resolution CT images. We examined a total of 41 normal ears in 25 subjects ranging in age from 12 to 82 years (mean age 46.2). The total volume of pneumatization was approximately 4.05 +/- 1.59 ml and the volume of air cells in the tympanic cavity was 0.45 +/- 0.07 ml. Alveolation of the petrous apex was detected in 15 (36.6%) of the 41 ears, and the volume of air cells in the petrous apex was approximately 0.24 +/- 0.26 ml. The volume of air cells in the mastoid antrum was approximately 0.53 +/- 0.20 ml. The ears were divided into two groups, one with petrous alveolation (15 ears) and the other without it (26 ears). The ratios of regional pneumatization to total pneumatization were studied in the two groups. Statistically significant differences were found in the total volume and the volume of air cells in the mastoid antrum between the groups with and without petrous pneumatization (p < 0.05). The total volume of air cells did not correlate to the volumes of air cells in the tympanic cavity, mastoid cavity and petrous apex.

Adolescent↗
PubMed1997

[Clinicopathological findings in 5 patients with acute eosinophilic pneumonia].

We studied 5 patients with acute eosinophilic pneumonia. Radiologic findings were Kerley's lines and pleural effusion on chest X-ray films, and interlobular septa on chest CT scans. Examination of transbronchial lung biopsy specimens revealed infiltration of eosinophils and lymphocytes into alveolar walls and edema of alveolar walls, interlobular septa, and perivascular connective tissue. The findings of interstitial edema were consistent with the radiological findings. Epithelial damage and bud-type intraluminal fibrosis were also seen, but residual alveolar structure was maintained. Bronchoalveolar lavage fluid contained abnormally high percentages of eosinophils and lympocytes. It also contained basophils and mast cells, which were not seen in fluid from normal subjects. Fluid from patients with chronic eosinophilic pneumonia had significantly fewer basophils than did fluid from those with acute eosinophilic pneumonia (p < 0.01). These findings suggest that release of chemical mediators from basophils plays a key role in interstitial edema in acute eosinophilic pneumonia.

Acute Disease↗
PubMed1997

[Clinical characteristics and muscle histopathology in polymyositis positive anti-hepatitis with C virus antibody].

In 14 patients with polymyositis (PM), 5 patients (2 males and 3 females) were positive for anti-hepatitis C virus (HCV) antibody measured by a second generation assay. We analysed the clinical characteristics and histopathological findings of the biopsied muscles from those 5 patients. They aged from 42 to 65 years averaging 53.6 years. Two asymptomatic patients visited our hospital due to elevated muscle enzyme levels, who had slight weakness in their orbicularis oculi and neck muscles on physical examination. The other 3 patients had moderate weakness of the proximal muscles. Anti-nuclear antibody was positive in 2 of the 5 patients and anti-Jo 1 antibody was negative in all patients. The serum enzymes elevated were creatine kinase (215-2, 207 (IU/l)) and glutamate oxaloacetate transaminase (40-119 (KU)). HCV-RNA was positive in the sera of 4 patients examined. All muscle biopsy specimens revealed variation in fiber size with inflammatory cellular infiltration and observed degenerating and regenerating fibers. The scant infiltration type was observed in 2 asymptomatic patients in whom the infiltrated cells were CD4 positive. The endomysial infiltration type was observed in 3 symptomatic patients; CD8 positive cells were found focally to diffusely in 2 patients examined. The expression of class 1 molecules from the major histocompatibility complex was detected mainly in infiltrated fibers to variable degrees. All of the patients showed a good response to the initial steroid therapy. The present study suggests that autoimmune reaction related to HCV infection causes myositis, therefore anti-HCV antibody should be checked in cases of PM.

Adult↗
PubMed1996

Pentacoordination of the heme iron of Arthromyces ramosus peroxidase shown by a 1.8 A resolution crystallographic study at pH 4.5.

In the presence of ammonium sulfate the absorption spectra of a peroxidase from the fungus Arthromyces ramosus (ARP) showed that the low-spin component increased as the pH increased from 6.0 to 9.0, whereas in its absence ARP remained in the high-spin state in the pH range investigated. The crystal structure of ARP at pH 4.5 in the presence of ammonium sulfate at 1.8 A resolution showed that the electron density at the 6th position of the heme iron seen at pH 7.5 had disappeared and that the iron atom deviated markedly from the heme plane. These observations strongly suggest that under physiological conditions the heme of ARP is in the pentacoordinated high-spin state and that at a high pH the heme iron is able to bind ammonia, forming the low-spin state. The location of the water molecule at the distal side of the heme in peroxidases is also discussed.

Crystallography, X-Ray↗
PubMed1996

An objective evaluation method for facial mimic motion.

This technique was designed to establish a simple, objective evaluation system for facial paralysis through the use of a personal computer. A total of 24 marks were placed on the faces of subjects for the following procedures. Movements of the face were photographed with a video-camera and fed continuously into the computer. Ten frames per movement representing facial movement from rest to maximum movement were selected for analysis. By means of a digital image-processing technique, only the marks placed on the face were extracted, and the movement of these marks was quantitatively analyzed. A total of 44 healthy subjects with no history of facial paralysis were used as a normal control group. The patients with facial paralysis consisted of nine subjects with Bell's palsy and three with Ramsay Hunt syndrome. In the eye-closing motions, no significant differences were found between the sum of the movement distances on the left and right sides in each normal subject. However, the patients with facial paralysis showed distinct differences from those obtained in the normal subjects. The improvement process was also evaluated with a ratio of affected- and normal-side facial movements.

Blinking↗
PubMed1996

Three-dimensional structure of bovine cytochrome bc1 complex by electron cryomicroscopy and helical image reconstruction.

Cytochrome bc1 complex from bovine heart has been reconstituted into tubular crystals. The three-dimensional structure of the complex in lipid bilayer has been obtained at an effective resolution of 16 angstrom by electron cryomicroscopy and helical image reconstruction. The complex is in a dimeric form, in which the monomers are associated closely in extramembrane domains on both sides of the membrane. The large inner domain is distinctively hollow and the small outer domain consists of a flat mass and two bulbous extrusions. These domains are connected by two narrow transmembrane columns. Locations of the subunits and the redox centres in the model are proposed.

Animals↗
PubMed1996

Atropine premedication attenuates heart rate variability during high thoracic epidural anesthesia.

BACKGROUND: Atropine premedication is used as it possesses an anticholinergic effect on the cardiac autonomic nervous system (CANS). The aim of this study was to investigate the effect of atropine premedication on the CANS during thoracic epidural anesthesia (TEA) by assessing power spectral analysis of heart rate (HR) variability. METHOD: Female patients (n = 28) undergoing elective mammary biopsy were randomly allocated into two groups; one received intramuscular premedication of 0.01 mg/kg of atropine 30 min before the procedure (group A: n = 14), and the other did not (group N: n = 14). Each electrocardiogram was digitally recorded before and during TEA, and played back off-line to detect R-R intervals. As a power spectrum required R-R intervals of 256 s, this was analysed before TEA and repeated thereafter for 25 min. The spectra were quantified by determining the peak areas of the spectral density by integrating low frequency (Lo: 0.04-0.15 Hz) and high frequency (Hi: 0.15-0.40 Hz) bands as they showed sympathetic and parasympathetic nervous activity in the CANS. The neural balance was assessed by calculating Hi:Lo ratio. RESULTS: Decreases in Lo and increases in Hi:Lo ratio were observed, suggesting sympathectomy and vagotonia with TEA in both groups. For 10 min after commencement, TEA maintained Hi:Lo ratios lower in group A than in group N, suggesting a vagolytic effect of premedication with atropine. With TEA, cardiac slowing was observed, which was dependent on the level of dermal analgesia. CONCLUSION: Power spectral analysis revealed that TEA had the effect of making CANS relatively vagotonic, and that atropine premedication would attenuate the effect of TEA.

Anesthesia, Epidural↗
PubMed1996

Heart rate variability during artificial ventilation and apnea in brain-damaged rabbits.

The effect of artificial ventilation, apnea, and norepinephrine administration on heart rate variability was determined in brain-damaged rabbits. Electrocardiographic R-R intervals and circulatory variables were measured for 5 min at three different ventilatory frequencies, including apnea under isoflurane general anesthesia. The same measurements were repeated after brain damage was inflicted by an inflated intracranial balloon. In control rabbits (n = 8) and in those receiving norepinephrine (n = 8), power spectral analysis of R-R intervals was repeated, and spectral components of low (LF: 0.04-0.09 Hz), mid (MF: 0.09-0.15 Hz), and high (HF: 0.15-0.40 Hz) frequency band areas were assessed. LF + MF (P < 0.05) increased during apnea, whereas HF did not change under general anesthesia. However, after brain damage in both groups LF + MF did not change, whereas HF was depressed (P < 0.05). There was no intergroup difference in decreases of HF/(LF + MF) (P < 0.05) during apnea under either condition. Norepinephrine increased heart rate and arterial pressure (P < 0.05) but did not produce any intergroup difference in the spectral components. We suggest that sympathovagal balance is apt to be sympathotonic during apnea under general anesthesia, whereas it is vagolytic with brain damage.

Animals↗