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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 289 records · Page 16Linked to original sources
PubMed1996

Effects of lecithinized superoxide dismutase on rat spinal cord injury.

Although superoxide dismutase (SOD) has been reported to promote functional recovery in ischemic spinal cord injury, it presents many difficulties in practical use primarily due to its short half-life in vivo and low tissue affinity. In this study, we investigated the effects of a new type of SOD, a lecithinized superoxide dismutase (PC-SOD), on motor disturbances, spinal cord edema, levels of myeloperoxidase (MPO), and spinal cord blood flow (SCBF) after spinal cord injury (SCI) in rats. PC-SOD is reported to show a delayed plasma disappearance in vivo in rats and has a higher affinity for vascular endothelium cells, neutrophils, and other cells than unmodified SOD. PC-SOD (4000 units/kg), unmodified SOD (4000 units/kg), or vehicle was injected intravenously 30 min after SCI. Four hours after SCI, SOD activities in spinal cord tissue and plasma were significantly higher in the PC-SOD group than in the unmodified SOD group. In the PC-SOD-treated rats, motor function was significantly better than in the other 2 groups of rats. PC-SOD significantly suppressed MPO activity, an indicator of neutrophils infiltration, in the spinal cord, at 4, 8, and 24 h after SCI, and spinal cord edema at 24 h after SCI. Moreover, the decrease of SCBF after SCI was less marked in the PC-SOD group. The present results suggest that lecithinization can improve the drug delivery of SOD to the spinal cord and PC-SOD may be an alternative pharmacological treatment for SCI.

Animals↗
PubMed1996

Endothelium-dependent relaxation of rat thoracic aorta by amrinone-induced nitric oxide release.

To determine whether amrinone and its induced increase of cyclic AMP releases nitric oxide and enhances endothelium-dependent vascular relaxation, we studied nitric oxide production and vascular relaxation of rat thoracic aorta on treatment with amrinone and forskolin, an activator of adenylate cyclase. When 20 microM amrinone was applied to ring segments of aorta previously contracted with phenylephrine, relaxation was greater in segments with endothelium than in those without (% relaxation 94 +/- 4 vs 37 +/- 7%, P < 0.01). However, a higher concentration of amrinone (> 50 microM) induced the same degree of relaxation in ring segments with or without endothelium, probably due to its direct effect on vascular smooth muscle. The maximal relaxant concentration (100 microM) of amrinone induced an increase (2.5 fold) in cyclic GMP in ring segments. Forskolin also induced concentration-dependent relaxation, but removal of the endothelium attenuated the relaxation induced by forskolin about seven-fold. NG-nitro L-arginine reversed the relaxation induced by amrinone or forskolin in ring segments with, but not without, endothelium. Nitric oxide production in ring segments of aorta, following application of amrinone or forskolin, was detected by nitric oxide-selective electrode and electron paramagnetic resonance spin trapping methods. Pre-treatment with NG-nitro L-arginine or removal of the endothelium suppressed nitric oxide production by amrinone or forskolin. These data showed that amrinone enhances the release of nitric oxide from rat aortic endothelial cells, and induces endothelium-derived relaxing factor/nitric oxide-mediated vasodilation.

Amrinone↗
PubMed1996

Endotoxin-induced L-arginine pathway produces nitric oxide and modulates the Ca2+-activated K+ channel in cultured human dermal papilla cells.

Endotoxin includes an enzyme that synthesizes nitric oxide (NO) from l-arginine (NO synthase) in vascular smooth muscles cells, macrophages, and fibroblasts, leading to the release of NO. We evaluated the release of NO and its intracellular action on the Ca2+-activated K+ channel (KCa channel) in cultured human dermal papilla cells by use of the electron paramagnetic response (EPR) spin trapping method and the patch clamp technique. In dermal papilla cells pretreated for 24 h with endotoxin (1 microgram/microliter), application of 1 microM L-arginine generated NO, although no measurable release of NO was observed in cells without endotoxin pretreatment, as determined by the EPR spin trapping method. With the patch clamp technique, we found that the KCa channel of dermal papilla cells had high conductance and was voltage dependent. In addition, after endotoxin pretreatment, the extracellular application of 100 microM l-arginine modulated the KCa channel in the cell-attached patch configurations. In inside-out patch configuration, however, NO produced by L-arginine itself did not modulate the Kca channel. The modulation of the KCa channel was suppressed by pretreatment with 100 microM N omega-nitro-L arginine methyl ester, and inhibitor of inducible and constitutive NO synthases. Methylene blue, a blocker of guanylate cyclase, inhibited the L-arginine-induced activation of the Kca channel. Theses results indicate that the endotoxin-induced L-arginine pathway cell generates No, which consequently modulated the KCa channel in cultured human dermal papilla cells by increasing of cyclic GMP-dependent phosphorylation.

Arginine↗
PubMed1996

Seroepidemiological survey of lymphocytic choriomeningitis virus in wild house mice in China with particular reference to their subspecies.

Serum samples from 337 wild house mice (Mus musculus) from 35 sites in China, collected in 1992 and 1993, were examined for antibodies against lymphocytic choriomeningitis virus (LCMV). Ten samples from eight sites were found to contain such antibodies. Six of the eight positive sites were located in the territory of M. m. gansuensis. One of the other two sites was located in the territory of M. m. castaneus in southern China and the other site was in a habitat of M. m. castaneus which had invaded into the western end of the territory of M. m. homourus. It seems likely that LCMV is distributed in the territories of M. m. gansuensis and M. m. castaneus in China. This is the first report of detection of these antibodies in wild house mice in China and specifically in the territories of M. m. gansuensis and M. m. castaneus.

Animals↗
PubMed1996

Aldosterone-dependent regulation of Na-K-ATPase subunit mRNA in the rat CCD: competitive PCR analysis.

In the cortical collecting duct (CCD), aldosterone increases the number of functionally active Na-K-adenosin-etriphosphatase (Na-K-ATPase) molecules by a mechanism involving an isoform-specific increase in the abundance of the Na-K-ATPase alpha 1- and beta 1-subunit protein. However, the molecular basis for the response, particularly in the mammalian CCD in vivo, has remained unclear. To resolve this issue, reverse transcription (RT) and a competitive polymerase chain reaction (PCR) were employed to study mineralocorticoid-dependent regulation of alpha 1- and beta 1-subunit mRNA in the rat CCD. Na-K-ATPase subunit-specific oligonucleotides primers were used in the PCR to amplify reverse-transcribed subunit mRNA (RT-mRNA) from single microdissected CCD. Control templates were constructed (84-bp deletion mutation of the rat Na-K-ATPase alpha 1-subunit cDNA and 70-bp deletion of the beta 1-subunit cDNA), serially diluted, and coamplified with the wild-type Na-K-ATPase subunit RT-mRNA from single CCD. PCR products of predicted size were observed by ethidium bromide staining. Southern blots with an internal subunit-specific oligonucleotide confirmed Na-K-ATPase alpha 1- and beta 1-subunit identity. The ratio of the amplified wild-type to mutant PCR products was found to be linear over the range of input control cDNA tested so that the amount of subunit mRNA could be determined. A chronic reduction in corticosteroid levels by bilateral adrenalectomy (7 days) reduced the apparent level of alpha 1-subunit transcript by 54.0 +/- 6.3% but not the beta 1-subunit. Administering aldosterone to physiological levels is sufficient to restore CCD alpha 1-subunit mRNA abundance toward control levels within 6 h. We conclude the following: 1) regulation of Na-K-ATPase of CCD in vivo can be attributed, at least in part, to mineralocorticoid-dependent control of Na-K-ATPase alpha 1-subunit mRNA abundance; and 2) competitive PCR may provide a sensitive and quantitative tool for determining hormone-dependent regulation of mRNA abundance in nephron segments.

Adrenalectomy↗
PubMed1996

Chondrocytes from osteoarthritic cartilage have increased expression of insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) and -5, but not IGF-II or IGFBP-4.

Osteoarthritis is a disease in which articular cartilage metabolism is altered, leading to cartilage destruction. As insulin-like growth factor-I (IGF-I) is the major anabolic mediator for articular cartilage, and the IGF-binding proteins (IGFBPs) are an integral part of the IGF axis, they may play a role in the pathophysiology of osteoarthritis. Chondrocytes isolated from fibrillated and normal appearing areas of osteoarthritic human cartilage and from normal cartilage were studied for IGF and IGFBP expression. IGF and IGFBP messenger ribonucleic acids were analyzed by a RT-quantitative PCR technique and Northern blotting. In osteoarthritic chondrocytes, IGF-I message was increased 3.5-fold, IGFBP-3 was increased 24-fold, and IGFBP-5 was increased 16-fold over normal chondrocytes. Chondrocytes from normal appearing areas of cartilage from osteoarthritic joints had intermediate levels. Message levels for beta-actin, IGF-II, and IGFBP-4 were unchanged between the cartilage types. IGF and IGFBP production were analyzed by Western ligand blots and RIAs of conditioned medium from cartilage cultured in serum-free conditions. IGF-I was undetectable in conditioned medium from normal cartilage and increased in that from osteoarthritic cartilage. Osteoarthritic cartilage samples produced IGFBP-2, -3, and -4; glycosylated IGFBP-4; and IGFBP-5. IGFBP-2, -3, and -5 production was increased in osteoarthritic cartilage. Proteases with activity against IGFBP-3 and -5 were also produced by osteoarthritic cartilage. The observation that IGFBP-3 and -5 expression and production are elevated in osteoarthritic cartilage suggests that they may be acting as a competitor for IGF-I in osteoarthritic cartilage, thus reducing the anabolic stimulation of this tissue and contributing to the net loss of cartilage in this disease.

Aged↗
PubMed1996

Short communication: MR imaging of fetal brain abnormalities using a HASTE sequence.

HASTE (half-Fourier acquisition single-shot turbo spin echo) is a sequence that enables T2 weighted magnetic resonance (MR) images to be obtained in a few seconds. The purpose of this study was to evaluate the usefulness of this sequence in the diagnosis of fetal cerebral abnormalities. Five fetuses suspected of having cerebral abnormalities on ultrasound examination were studied by MR imaging using the HASTE sequence in utero. We compared the images with post-natal MR images or computed tomography (CT) scans. In four fetuses, the abnormality was diagnosed correctly, and the diagnosis was almost correct in the remaining fetus. This sequence is useful because it provides images of diagnostic quality in a very short scanning time.

Brain↗
PubMed1996

Ludloff's medial approach for open reduction of congenital dislocation of the hip. A 20-year follow-up.

We reviewed 33 patients (35 hips) after open reduction of congenital dislocation of the hip using Ludloff's medial approach. The mean age at the time of operation was 14 months (5 to 29) and at the time of final follow-up 20.1 years (15 to 24) giving a mean duration of follow-up of 19.4 years (14 to 23). We evaluated the radiological results by the Severin classification and the extent of avascular necrosis using the criteria of Kalamchi. At the latest review 16 hips (45.7%) were in Severin groups I or II (acceptable results) and 19 (54.3%) in Severin groups III, IV or V (unacceptable results). There was evidence of avascular necrosis in 15 hips (42.9%). The radiological results began to become worse at about the age of ten years when type-II avascular changes presented. We conclude that Ludloff's medial approach for open reduction is unsatisfactory for the treatment of congenital dislocation since about half of our patients required additional operations.

Child, Preschool↗
PubMed1996

Sound stimulation-induced vasomotor reflex in the central artery of the rabbit ear.

Effects of sound stimulation on the central artery of the rabbit ear were studied as a somato-autonomic reflex. Vasoconstriction and dilatation, caused by metronome sound stimulation, were estimated from the temperature fluctuations in the central artery of the ear, measured by a thermistor. To enhance the detection of temperature rises, moderately high background levels of arterial tone were established by exposing the tips of the ears to water at a temperature of 10 degrees C or 5 degrees C, prior to sound stimulation. A fall in arterial temperature due to vasoconstriction was observed immediately after the start of the 1-min sound stimulation, with a subsequent temperature rise which overshot the original basal level due to vasodilatation. A positive correlation between the ear temperature before sound stimulation and the temperature fall (p < 0.01), and a negative correlation between the ear temperature and the temperature rise (p < 0.05) were obtained. The temperature fall was blocked by phenoxybenzamine (9 mg/kg, i.p., p < 0.01). The subsequent rise was not influenced by atropine (3 mg/kg, i.p.) or phenoxybenzamine, however, it was attenuated by hexamethonium (6 mg/kg, i.p., p < 0.05). The temperature fall at the beginning of sound stimulation was related to alpha-adrenergic mechanism. The subsequent temperature rise was thought to be related to parasympathetic mechanism, excluding cholinergic mechanism.

Acoustic Stimulation↗
PubMed1996

[A case of POEMS syndrome with various complications].

A 65-year old man presented with complaints of sclerosis of skin and numbness in the extremities. During last 10 year, he had developed monoclonal gammopathy, Raynaud's phenomenon, ischemic heart disease, sigmoid colon cancer, hyperkalemia, polyneuropathy and scleroderma-like skin changes. Laboratory examinations revealed a monoclonal protein (IgA-lambda) and an elevated serum level of IL-6. Subsequently a diagnosis of POEMS syndrome was made based on the clinical features and laboratory findings which were characteristic of this syndrome. Further examinations showed the presence of glomerulonephritis and brain tumor. These various complications are of great interest in understanding the pathogenesis of POEMS syndrome.

Aged↗
PubMed1996

RT-PCR analysis of MMP-9 expression in human articular cartilage chondrocytes and synovial fluid cells.

This report presents a method for analyzing matrix metalloproteinase-9 (92 kD gelatinase) MMP-9 mRNA expression using reverse transcription polymerase chain reaction (RT-PCR). With this method, chondrocytes isolated from small samples of osteoarthritic cartilage showed significantly elevated signal for MMP-9 mRNA compared to normal cartilage. In addition, cells of synovial fluid samples aspirated from osteoarthritic joints also exhibited MMP-9 expression using this technique. RT-PCR proved to be a sensitive method for assessing MMP-9 regulation in osteoarthritic and normal cartilage, and may provide a useful index of arthritic cartilage and synovial fluid cell metabolism when limited tissue is available.

Cartilage, Articular↗
PubMed1996

[One stage operation for ischemic heart disease and abdominal aortic aneurysm with ascending aortic calcification].

A 69-year-old man was referred to us with the diagnosis of abdominal aortic aneurysm (7 cm in diameter). Additionally his coronary arteriogram showed severe stenosis (LMT 75% and #6 99% delay). Because his ascending aorta was calcified severely, double CABG (LITA to LAD and RGEA to PL) was carried out in hypothermic ventricular fibrillation. Abdominal aortic aneurysm was replaced thereafter while the patient was still on cardiopulmonary bypass. His postoperative courses was satisfactory. In cases requiring early operation for both myocardial ischemia and abdominal aortic aneurysm, one stage operation was recommended. When atherosclerotic changes in the ascending aorta were severe, in situ arterial bypass grafting for ischemic heart disease under hypothermic ventricular fibrillation was useful.

Aged↗
PubMed1996

[An unusual autopsy case of corticobasal degeneration--with special reference to clinicopathological differentiation from progressive supranuclear palsy and slowly progressive aphasia].

We report an unusual autopsy case of corticobasal degeneration. The patient was male who was 67 years old at the time of his death. He developed clumsiness of his right hand at age 65. Neurological examination at age 66 revealed supranuclear ophthalmoplegia of upward gaze and parkinsonism. Progressive supranuclear palsy was suspected. The patient's clinical course was rapidly progressive. Dementia developed nine months after the onset of the disease, and the patient manifested apallic syndrome at 21 months and died of pneumonia at about 25 months. At autopsy the brain weighed 1370g. Macroscopic examination revealed prominent atrophy of the anterior and parietal lobes, particularly of the pars opercularis in the left inferior frontal gyrus, and there was marked depigmentation of the substantia nigra. Histological examination showed neuronal loss, glial proliferation, spongy state, and ballooned neurons in the frontal and parietal lobes. Neuronal loss with glial proliferation was conspicuous in the striatum, pallidum, thalamus, and substantia nigra. There was slight neuronal loss in the dentate nucleus and locus ceruleus. Staining by Gallyas-Braak method revealed massive appearance of argyrophilic threads. This case is important in terms of the clinical differentiation from progressive supranuclear palsy, and is also interesting in regard to the pathological correlation with slowly progressive aphasia.

Aged↗
PubMed1996

Three-dimensional helical CT angiography of skull base meningiomas.

PURPOSE: To describe the findings of skull base meningiomas on three-dimensional CT angiograms obtained with helical scanning and to evaluate the usefulness of this method. METHODS: Fifteen patients who had a meningioma near the skull base were examined with helical CT after receiving an intravenous bolus injection of contrast material. RESULTS: All meningiomas had either a honeycomb (12 patients) or solid (3 patients) pattern of enhancement. Bony structures of the skull base and adjacent major arteries that were displaced or surrounded by tumor were also evident. CONCLUSION: Three-dimensional CT angiography depicts the relationship between skull base meningiomas and neighboring bony and vascular structures clearly, quickly, and with minimal risk to the patient.

Adult↗
PubMed1996

[Effects of topical application of isopropyl unoprostone on refraction and accommodation].

The effect of topical application of prostaglandin-related compound isopropyl unoprostone on refraction and accommodation were examined. Topical application of isopropyl unoprostone obviously reduced the intraocular pressure, but no significant change in refraction was observed. Amplitude of accommodation, i.e., near point and far point of accommodation, were kept unchanged, although isopropyl unoprostone produced a slight hyperopic shift in dark focus of accommodation. These findings suggest that the reduction of intraocular pressure needs to be explained by a mechanism other than the relaxation of ciliary muscles.

Accommodation, Ocular↗
PubMed1996

[A study of arterial infusion chemotherapy for gastric cancer patients with peritoneal metastasis].

We analyzed the clinical response, toxicities, out-patient and overall survival time among 41 gastric cancer patients with peritoneal metastasis to evaluate chemotherapies and drug delivery routes. Sixteen patients were treated by arterial infusion (AI) and 25 by systemic therapy (ST), with either 5-FU/MTX (FMTX) therapy or 5-FU/CDDP (FP) therapy. Partial response was observed in 8 patients (50%) among 16 with AI and in 6 (24%) among 25 with ST (p = 0.09). There were no differences in the incidence of side effects (> or = grade 2 according to WHO criteria) between AI and ST group, at 25% and 36%, respectively. No significant differences were observed in either survival time or home care duration among patients with AI chemotherapy and those with ST procedure.

Antineoplastic Combined Chemotherapy Protocols↗