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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 631 records · Page 35Linked to original sources
PubMed1994

Influence of daily drinking habits on ethanol-induced hyperuricemia.

We examined the influence of alcohol drinking habits on the serum uric acid level after the ingestion of a small amount of ethanol. Subjects were divided into two groups according to their alcohol drinking habits--regular drinkers, who consume more than 60 g ethanol every day, and nondrinkers/occasional drinkers, who consume less than 20 g ethanol occasionally. Drinking 0.5 g ethanol/kg increased serum uric acid levels in regular drinkers by 52.6 +/- 26.3 mumol/L (0.8 +/- 0.4 mg/dL), whereas it did not in nondrinkers/occasional drinkers. Urinary excretion of uric acid was unaltered in both groups. Hypoxanthine and xanthine in both plasma and urine and serum acetate were increased more in regular drinkers than in nondrinkers/occasional drinkers. Accelerated adenine nucleotide degradation secondary to enhanced ethanol oxidation likely explains the ethanol-induced hyperuricemia in regular drinkers.

Acetates↗
PubMed1994

Distribution of cocaine recognition sites in rat brain: in vitro and ex vivo autoradiography with [125I]RTI-55.

The distribution of binding sites of [125I]RTI-55 (3 beta-(4-iodophenyl)tropan-2 beta-carboxylic acid methyl ester), a phenyl tropane analog of cocaine, and the selective labeling of the dopamine transporter (DAT) were studied by in vitro and ex vivo autoradiography in the rat whole brain. Recent evidence has shown that RTI-55 binds to not only DAT but also serotonin transporter (5HTT). In the present study, in vitro autoradiography revealed that [125I]RTI-55 bound to the olfactory tubercle, the caudate putamen, the accumbens nucleus, the midline and lateral geniculate nuclei of the thalamus, the hypothalamic nuclei, the substantia nigra compact part, the subthalamic nucleus, the ventral tegmental area, the superior colliculus, the dorsal raphe nucleus, and the facial nucleus. Further, in the presence of clomipramine, a selective ligand for 5HTT, [125I]RTI-55 binding was remarkably inhibited in the midline and lateral geniculate nuclei of the thalamus, the hypothalamic nuclei, the superior colliculus, the dorsal raphe nucleus, and the facial nucleus, while [125I]RTI-55 binding remained in the olfactory tubercle, the caudate putamen, the accumbens nucleus, the substantia nigra compact part, the subthalamic nucleus, and the ventral tegmental area. These findings suggest that [125I]RTI-55 binds to 5HTT in the former areas and to DAT in the latter areas. It is therefore concluded that RTI-55 is a suitable ligand for studying the action of cocaine in whole brain regions, including the thalamus, the hypothalamus and the dorsal raphe nucleus, regions in which cocaine is thought to act evoking several neurological effects, e.g., analgesia and elevation of adrenocorticotropic hormone. DAT was also labelled selectively both in vitro and in vivo using [125I]RTI-55 combined with clomipramine. Therefore, radiolabelled RTI-55, combined with unlabelled clomipramine, which displaces its binding to 5HTT, also appears to be suitable for the selective imaging of DAT in vivo.

Animals↗
PubMed1994

Effect of etodolac on prostaglandin E2 biosynthesis, active oxygen generation and bradykinin formation.

The inhibitory actions of etodolac on prostaglandin (PG) E2 biosynthesis, active oxygen generation and bradykinin formation were compared with those of indomethacin, diclofenac Na, piroxicam, naproxen, ketoprofen and aspirin. The inhibitory action (IC50 5.35 x 10(-8) M) of etodolac on PGE2 biosynthesis in rabbit articular chondrocytes stimulated by interleukin-1 (IL-1) beta was about 1/5 that of indomethacin. The inhibitory action of etodolac on spontaneous PGE2 biosynthesis in rabbit gastric epithelial cells (RGEs) (IC50 2.27 x 10(-5) M) and Madin-Darby canine kidney cells (MDCKs) (IC50 4.54 x 10(-7) M) was much less than that in rabbit articular chondrocytes stimulated by IL-1 beta and about 1/19 and 1/9 that of indomethacin in rabbit gastric epithelial cells (RGEs) and Madin-Darby canine kidney cells (MDCKs), respectively. The inhibitory action of etodolac on active oxygen generation was similar to that of indomethacin and piroxicam, and more potent than that of naproxen, ketoprofen and aspirin. The inhibitory action of etodolac on bradykinin formation was the most potent among the seven anti-inflammatory drugs tested. Both etodolac and bromelain inhibited the inflammatory pain in concanavalin A-treated paws of rats in a dose-dependent manner, but indomethacin did not. These results indicate that etodolac is an anti-inflammatory drug which suppress IL-1 beta-stimulated PGE2 biosynthesis in rabbit articular chondrocytes, active oxygen generation and bradykinin formation. It has less suppressive action against spontaneous PGE2 biosynthesis in RGEs and MDCKs. Thus, etodolac is considered to be a safe anti-inflammatory drug for clinical use.

Animals↗
PubMed1994

Pleomorphic adenoma of parotid gland with cystic degeneration.

Pleomorphic adenoma is the most common tumour to arise in the parotid gland. Diagnosis becomes difficult when such a tumour undergoes degeneration and presents with unusual findings. This can lead to erroneous decisions concerning treatment. We present two patients with pleomorphic adenoma of the parotid gland with cystic degeneration, describe the pathological findings and discuss some pitfalls in diagnosis and treatment. Both patients recovered uneventfully after surgery.

Adenoma, Pleomorphic↗
PubMed1994

Implication of the common gamma chain of the IL-7 receptor in intrathymic development of pro-T cells.

The effects of IL-7 on the growth and differentiation of thymocytes were analyzed using murine fetal thymus organ cultures (FTOC) in the presence of mAbs specific for the conventional IL-7 receptor (IL-7R) and for the common gamma (gamma c) chain. In FTOC, the development of CD4-CD8- double-negative thymocytes to CD4+CD8+ double-positive (DP) and CD4+ or CD8+ single-positive (SP) cells was not completely blocked by adding these mAbs, although cell growth was reduced by the treatment. To define a developing stage sensitive to the mAbs, most immature thymocytes, Pgp-1+ c-kit+ cells, were cultured in 2-deoxyguanosine treated fetal thymus. In the presence of both mAbs in the culture, neither DP nor SP thymocytes developed whereas either of the mAbs partially blocked their development. These results indicate that the gamma c chain is involved in early T cell development as an indispensable subunit of the functional IL-7 receptor complex.

Animals↗
PubMed1994

Myocardial involvement in patients with sarcoidosis. An analysis of 75 patients.

The authors studied 75 nonselected patients (30 men and 45 women; mean age 48 years) with sarcoidosis retrospectively to assess the applicability of nuclear examinations for detecting myocardial involvement. All patients were studied with Tl-201 myocardial perfusion scan (TMPS), Ga-67 myocardial scan (GMS), and left ventricular ejection fraction (LVEF) using ECG-gated radionuclide ventriculography. The positive GMS group had a significantly higher occurrence of abnormality on TMPS (100%) than the negative GMS group (41%). Patients with TMPS abnormality and positive GMS showed significantly lower LVEF (36.3%) than those of normal perfusion or negative GMS. When LVEF decreased, occurrences of TMPS abnormality and positive GMS increased. The authors demonstrate that in patients with sarcoidosis LVEF was closely related to TMPS and GMS, and LVEF reflected the progression of sarcoid heart disease and can be considered a reliable indicator of cardiac function. Patients with sarcoidosis with TMPS abnormality and positive GMS should be thought to have myocardial sarcoidosis and their cardiac functions can be assessed by ECG-gated radionuclide ventriculography, while the remaining patients should be examined with TMPS and GMS periodically for detection of myocardial involvement.

Adult↗
PubMed1994

Clinical application of spontaneous red blood cell labeling with Tc-99m sodium pertechnetate.

Red blood cells (RBC) may be labeled with Tc-99m after Tc-99m sodium pertechnetate is injected in the presence of a reducing agent, such as stannous chloride. Thus, spontaneous RBC labeling with Tc-99m is expected to be seen in patients with a high plasma concentration of tin. Spontaneous RBC labeling with Tc-99m was obtained in a 73-year-old woman who was clinically diagnosed with tin intoxication and proved to have a high concentration of plasma tin. The RBC labeling rate was calculated as 96% with blood sampling. Spontaneous RBC labeling with Tc-99m is a very simple method for proving a high plasma tin concentration and is adaptable to clinical diagnosis.

Aged↗
PubMed1994

Expression of tumor-associated glycoantigen, sialyl Lewis(a), in human head and neck squamous cell carcinoma and its application to tumor immunotherapy.

The glycoantigen sialyl Lewis(a) (sLe(a)) is widely expressed on a variety of gastrointestinal tumor cells. Here, we immunohistochemically demonstrated the expression of sLe(a) antigen in 54% (7 out of 13) of human head and neck squamous cell carcinoma (H-NSCC) samples. Frequent expression of sLe(a antigen was also demonstrated on a variety of H-NSCC cell lines using flow cytometry. Both CD4+ and CD8+ T cells, which were activated with immobilized OKT3 monoclonal antibody plus interleukin-2, showed augmented cytotoxicity against sLe(a)-positive H-NSCC, including autologous tumor cells, on targeting with anti-CD3 x anti-sLe(a) bispecific antibody, suggesting that sLe(a) antigen is a good target molecule for bispecific antibody-dependent adoptive tumor immunotherapy of human head and neck cancer.

Adult↗
PubMed1994

Abnormal factor VIII Hiroshima: defect in crucial proteolytic cleavage by thrombin at Arg1689 detected by a novel ELISA.

We have established an ELISA for detecting thrombin cleavage of the FVIII light chain at Arg1689. The method used a coating alloantibody which recognized amino acid residues 2248-2312 in the C2 domain, together with a second monoclonal antibody, NMC-VIII/10, which recognized residues 1675-1684 in the amino-terminal region of the light chain. FVIII antigen (FVIII:Ag) was measured after treatment of plasma with various concentrations of thrombin. The FVIII:Ag of normal plasma was reduced in a dose-dependent manner by the thrombin, falling to 28% in the presence of 100 U/ml enzyme. The concentration of thrombin that achieved 50% reduction (IC50) was approximately 1.0 U/ml. The plasma of four haemophilia A positive (A+) and two haemophilia A reduced (AR) patients were analysed. The IC50 of all patients was more than 1.0 U/ml, indicating that thrombin cleavage of the FVIII light chain was defective. One haemophilia A+ plasma did not respond to thrombin in this ELISA system. The patient (TI) was a haemophiliac with FVIII coagulant activity of 0.04 U/ml and FVIII:Ag of 1.78 U/ml. In addition, immunoblotting of the purified FVIII from TI showed that thrombin cleavage of the 80 kilodalton (kD) light chain was impaired. The patient's DNA was amplified using the polymerase chain reaction with a set of synthetic oligonucleotide primers spanning amino acid residues 1646-1714. Sequence analysis of the amplified DNA fragments revealed a cytosine to thymine transition, converting an arginine 1689 to cysteine. This abnormal FVIII was designated as FVIII Hiroshima. Our ELISA system is a simple and useful method of evaluating the proteolytic cleavage by thrombin at Arg1689.

Arginine↗
PubMed1994

Glial fibrillary acidic protein: dynamic property and regulation by phosphorylation.

Glial fibrillary acidic protein (GFAP) is an intermediate filament (IF) protein of astroglia, and belongs to the type III subclass of IF proteins. IF proteins are composed of an amino-terminal HEAD domain, a central ROD domain and a carboxyterminal TAIL domain. GFAP, with a molecular mass of approximately 50 KDa, has the smallest HEAD domain among type III IF proteins. Despite its insolubility, GFAP is in dynamic equilibrium between assembled filaments and unassembled subunits, as demonstrated using fluorescently labeled GFAP molecules. Like other IF proteins, assembly of GFAP is regulated by phosphorylation-dephosphorylation of the HEAD domain by altering its charge. This regulation of GFAP assembly contributes to extensive remodeling of glial frameworks in mitosis. Another type III IF protein, vimentin, colocalizes with GFAP in immature, reactive or radial glia, thereby indicating that vimentin has an important role in the build up of the glial architecture.

Animals↗
PubMed1994

Ultrastructure of the intramuscular connective tissue in bovine skeletal muscle. A demonstration using the cell-maceration/scanning electron microscope method.

The three-dimensional arrangement of intramuscular connective tissues in bovine semitendinosus muscle was investigated using the cell-maceration method for scanning electron microscopy, by which cellular elements were eliminated and collagen fibrils and fibers were exposed. The 60-100 microns diameter honeycomb structures of the endomysium housing individual muscle fibers were clearly observed. The sheath of endomysium was membranous and consisted of tightly arranged collagen fibrils 30-70 nm in diameter. The perimysium was composed of several layers of 100-200 microns-thick sheets surrounding the sheaths of the endomysium. The sheets of the perimysium were wavy and consisted of collagen fibers made up of tightly bundled fibrils. The epimysium was composed of two distinct layers of thick sheets. The inner layer consisted of thousands of collagen fibers lying in an extremely regular wavy pattern parallel to the axis of the muscle fiber. The outer layer of epimysium was composed of several wavy sheets of collagen fibers which ran transversely to the axis of the muscle fiber. In a region of the epimysium, there was a thick wall of about 1 mm thickness, where fiber bundles of 200-300 microns in diameter ran longitudinally parallel to the axis of muscle fiber.

Animals↗
PubMed1994

Acute bilateral cerebellar infarction in the territory of the medial branches of posterior inferior cerebellar arteries.

BACKGROUND: We describe the first clinicoradiological report of acute bilateral cerebellar infarction confined to the territory of the medial branches of the posterior inferior cerebellar arteries. CASE DESCRIPTION: A 65-year-old man with atrial fibrillation and hypertension had sudden onset of vertigo, followed by brief loss of consciousness. Three days later a cranial computed tomographic scan showed acute hydrocephalus and low-density areas in the cerebellar vermis on both sides. On transfer the patient showed mild dysarthria, dysequilibrium with retropulsion, symmetrical bilateral horizontal gaze-evoked nystagmus on lateral gaze, and marked gait ataxia without brain stem signs, followed by marked vertigo that was induced by motion. Cranial magnetic resonance imaging revealed abnormalities consistent with fairly symmetrical bilateral cerebellar hemorrhagic infarction that was confined to the territory of the medial branches of the posterior inferior cerebellar arteries, in addition to minimal high-intensity areas in the pons on T2-weighted images. The patient improved with conservative therapy, including intravenous administration of glycerol. CONCLUSIONS: We speculate that our patient likely had initial transient occlusion of the right vertebral artery at the origin of the right posterior inferior cerebellar artery, which probably gave rise to the bilateral medial branches of posterior inferior cerebellar arteries. This caused infarction in the territory of the medial branches on both sides without remaining brain stem signs. Such an unusual pattern of cerebellar infarction accompanied by acute hydrocephalus posed a diagnostic challenge at the time of transfer to our care, and correct diagnosis was facilitated by cranial magnetic resonance imaging.

Aged↗
PubMed1994

Alveolar fluid clearance in the resected human lung.

Although the mechanisms responsible for alveolar liquid clearance have been studied in several species, there has not been any information regarding the effect of ion transport agonists or antagonists on alveolar liquid clearance in the human lung. Therefore, we studied alveolar liquid clearance in the recently resected human lung from patients who underwent surgery for lung cancer. A test solution of 40 ml of isosmolar albumin solution was instilled into one segment of a resected lobe within 10 min of resection. Because protein leaves the air spaces very slowly, the concentration of alveolar protein over 4 h was used to quantify alveolar liquid clearance. Basal alveolar liquid clearance was 12 +/- 2% over 4 h. Amiloride (10(-5) M), an inhibitor of apical Na+ uptake, and ouabain (10(-3) M), an inhibitor of Na,K-ATPase activity, reduced alveolar liquid clearance by 40 and 49%, respectively (p < 0.005). Terbutaline (10(-3) or 10(-4) M) doubled alveolar liquid clearance to 28 +/- 9% over 4 h (p < 0.05). Propranolol (10(-4) M) and amiloride (10(-5) M) inhibited the terbutaline-induced increase in alveolar liquid clearance. In conclusion, (1) alveolar liquid clearance in the human lung can be markedly reduced by inhibition of apical sodium channel uptake or Na,K-ATPase activity, and (2) beta-adrenergic stimulation markedly increases the rate of alveolar liquid clearance in the resected human lung without pulmonary perfusion.

Aged↗
PubMed1994

Fungal metabolites. XIII. Isolation and structural elucidation of new peptaibols, trichodecenins-I and -II, from Trichoderma viride.

Three new groups of peptaibols, trichodecenins, trichorovins and trichocellins, have been isolated from conidia of the fungus, Trichoderma viride. The structures of trichodecenins-I and -II were established by positive-ion fast-atom bombardment, collision-induced dissociation mass spectrometry and two-dimensional NMR spectroscopy. Trichodecenins-I and -II have a (Z)-4-decenoyl group, six amino acid residues and a leucinol moiety in the molecules. Trichodecenin-II was synthesized by the solution-phase method.

Amino Acid Sequence↗
PubMed1994

Reduction of the mortality rate by imidapril in a small coronary artery disease model, (NZW x BXSB)F1 male mice.

For this study, we used (NZW x BXSB)F1 male mice as a model of myocardial infarction. The animals were kept on water containing imidapril or enalapril at 60 mg/kg/day from 10 to 27 weeks of age. Imidapril and enalapril significantly reduced the blood pressure. Imidapril reduced the mortality rate more significantly than enalapril did. In the second experiment where imidapril, enalapril and captopril were administered to the mice at 5 mg/kg/day, p.o., both imidapril and captopril significantly reduced the mortality, but enalapril did not. Blood pressure was slightly reduced by these ACE inhibitors. These data suggest that imidapril and captopril are efficacious for the treatment of myocardial infarction and blood pressure reduction hardly contributes to its mechanism of action.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

Atrial natriuretic polypeptide (ANP)-immunoreactivity and specific atrial granules in cardiac myocytes of stroke-prone spontaneously hypertensive rat (SHRSP).

The distribution of atrial natriuretic polypeptide (ANP) and atrial specific granules in the myocytes of the atria and ventricles of an experimental animal model, stroke-prone spontaneously hypertensive rats (SHRSP) and a control, Wistar Kyoto rats (WKY), was examined using immunocytochemical and electron microscopic techniques. In the atria of both SHRSP and WKY, ANP-immunoreactivity was recognized in the perinuclear regions of essentially all cardiac myocytes. In the ventricles of WKY, ANP-immunoreactivity was hardly seen except for the impulse-conducting system. However, in the ventricles of SHRSP, almost all cardiac myocytes possessed immunoreaction products which were scattered evenly throughout the cytoplasm; this distribution pattern differed from that of the atrial wall of this strain.

Animals↗
PubMed1994

Successful percutaneous transluminal angioplasty of the intracranial vertebral artery 1 month after total occlusion--case report.

A 51-year-old male suffering from recurrent cerebral ischemia due to total occlusion of the bilateral intracranial vertebral arteries more than 1 month old was successfully treated by percutaneous transluminal angioplasty (PTA). The totally occluded portion from the right intracranial vertebral artery to the basilar artery was adequately dilated. Follow-up angiography approximately 3 months after angioplasty demonstrated no evidence of restenosis. His symptoms have not recurred. PTA is potentially a much less invasive and safer reconstruction than bypass surgery for total occlusions of the intracranial vertebral arteries less than 3 months old.

Angioplasty, Balloon↗