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Biomedical subjects

T Kudo

Publications and source records attributed to T Kudo.

At least 235 records · Page 13Linked to original sources
PubMed1998

Effects of thiopental on airway calibre in dogs: direct visualization method using a superfine fibreoptic bronchoscope.

Induction of anaesthesia with thiopental sometimes causes bronchospasm. Although the mechanism by which thiopental induces bronchospasm may involve cholinergic stimulation, direct spastic effect and histamine release, the spastic effects of thiopental have not been comprehensively defined. In this study, we have assessed the effect of thiopental on in vivo airway smooth muscle tone using direct visualization method with a superfine fibreoptic bronchoscope as previously reported. Twenty-one mongrel dogs were anaesthetized with pentobarbital (30 mg kg-1) and paralysed with pancuronium (200 micrograms kg-1 h-1). The trachea was intubated with a tube that had a second lumen for insertion of the bronchoscope (od: 2.2 mm) to continuously measure bronchial cross-sectional area. The tip of the bronchoscope was placed between the second and third bronchial bifurcation of the right lung. The dogs were allocated to three groups of seven: group T, A+T, H+T. In group T, thiopental 0 (saline), 0.1, 1.0 and 10 mg kg-1 was given i.v. In group A+T, saline i.v., 5 min later atropine 0.1 mg kg-1 i.v., and 5 min later thiopental 10 mg kg-1 was administered. In group H+T, bronchoconstriction was produced with histamine 10 micrograms kg-1 i.v. followed by infusion at 500 micrograms kg-1 h-1. Thirty minutes later, thiopental 0, 1.0 and 10 mg kg-1 were given. Arterial blood sampling was performed for measurement of plasma catecholamines and histamine. In group T, thiopental significantly reduced bronchial cross-sectional area (maximally by 28.7 (5.6% at 0.5 min after thiopental 10 mg kg-1), which returned to the baseline in 3 min, while any changes in plasma concentrations of catecholamines and histamine were not observed except norepinephrine level at 1 min following thiopental 10 mg kg-1 i.v. Atropine pretreatment completely prevented thiopental-induced bronchospasm in group A+T. In group H+T, thiopental 10 mg kg-1 transiently but significantly decreases bronchial cross-sectional area. Therefore, the present study indicates that the mechanism of thiopental bronchospasm may result from cholinergic nerve stimulation.

Anesthetics, Intravenous↗
PubMed1998

Description of four new species of the genus Kineosporia: Kineosporia succinea sp. nov., Kineosporia rhizophila sp. nov., Kineosporia mikuniensis sp. nov. and Kineosporia rhamnosa sp. nov., isolated from plant samples, and amended description of the genus Kineosporia.

Eleven motile spore-bearing actinomycetes were isolated from various plant samples and were studied to determine their taxonomic positions. The isolates showed colony appearance and morphology similar to those of the 'sporedome actinomycetes' previously described by L. G. Willoughby in 1969. Although the isolates showed variety in composition of isomers of 2,6-diaminopimelic acid in the cell walls and in whole-cell sugar patterns, all of the isolates were classified in the genus Kineosporia Pagani and Parenti 1978 emend. Itoh et al. 1989 on the basis of their morphological and other chemotaxonomic characteristics, i.e., menaquinone, phospholipid and cellular fatty acid compositions. This assignment to the genus was also supported by a phylogenetic analysis using the 16S rRNA gene sequences. By DNA-DNA hybridization experiment, five genospecies were recognized among the isolates, and one of them showed high levels with the type strain of the type species, Kineosporia aurantiaca, which is the sole member of the genus. These genospecies can be distinguished from each other by their cultural, physiological and biochemical characteristics, and the other four genospecies should be placed into four new species for which the names Kineosporia succinea (type strain I-273T = JCM 9957T), Kineosporia rhizophila (type strain I-449T = JCM 9960T), Kineosporia mikuniensis (type strain I-463T = JCM 9961T) and Kineosporia rhamnosa (type strain I-132T = JCM 9954T) are proposed.

Actinomycetales↗
PubMed1998

Increased tau protein level in postmortem cerebrospinal fluid.

Microtubule-associated protein tau has been reported to be significantly increased in cerebrospinal fluid (CSF) of the patients with Alzheimer's disease (AD), which suggests that it is possibly a biological marker for the diagnosis of AD. The underlying mechanism of the increased tau level in CSF, however, is not known. In this study, the tau levels were compared between antemortem and postmortem CSF. The postmortem tau levels in CSF were significantly increased in all groups including AD, neurological control, and nondemented control. A striking elevation of CSF tau was observed during the postmortem change with the nondemented subjects. These findings may offer some insight into the understanding of the mechanism of the increased tau level in CSF with AD and other related disorders.

Aged↗
PubMed1998

White matter changes in the gerbil brain under chronic cerebral hypoperfusion.

BACKGROUND AND PURPOSE: An animal model of chronic cerebral hypoperfusion was developed with coiled clips applied to both carotid arteries of adult Mongolian gerbils for between 1 week and 2 months. In the brain of this animal model, rarefaction of white matter with dilatation of the ventricles was frequently observed. To better understand the mechanism of white matter alteration under cerebral hypoperfusion, the chronological sequence of molecular changes in the cerebral white matter of the animal model was determined. METHODS: Specially designed coiled clips were placed around both carotid arteries of Mongolian gerbils to create stenosis without occlusion. Changes in levels of myelin basic protein (MBP) as a marker of myelin, neurofilament H (NFH) as a marker of axonal proteins, and glial fibrillary acidic protein (GFAP) in astroglia after 2 months of cerebral hypoperfusion were analyzed with Western blotting and enzyme-linked immunosorbent assay. RESULTS: Western blotting of the white matter after 2 months of hypoperfusion showed that the levels of MBP and NFH decreased, whereas that of GFAP increased. The time course of MBP and NFH changes determined with enzyme-linked immunosorbent assay revealed that the change of MBP preceded that of NFH. CONCLUSIONS: In the present study it was shown that the damage to myelin precedes that to the axon in the white matter in a chronic cerebral hypoperfusion animal model, suggesting that the change in myelin is the primary pathological event in the cerebral white matter under chronic hypoperfusion. The present study may help in understanding the mechanisms of white matter pathology in leukoaraiosis.

Animals↗
PubMed1998

Cardiac sympathetic stimulation increases cardiac contractility but decreases contractile efficiency in canine hearts in vivo.

The effect of cardiac sympathetic stimulation on cardiac contractile efficiency was studied in dogs. In 19 anesthetized and open-chest dogs, left ventricular (LV) pressure, LV volume, coronary blood flow and coronary venous oxygen saturation were measured simultaneously. The LV end-systolic pressure volume relations (ESPVR) and the relation between myocardial oxygen consumption (VO2)-pressure volume area (PVA) were obtained during a transient occlusion of the inferior vena cava before and after sympathetic stimulation (9V, 6 Hz, 40 sec) both with and without 50 mg/kg of 2,3-butanedione monoxime (BDM). Without BDM, sympathetic stimulation increased the slope of ESPVR by 62% (p<0.05), the slope of the VO2-PVA line by 19% (p<0.05) and the y-axis intercept of the VO2-PVA by 65% (p<0.05). With BDM, the increase in the slope of the VO2-PVA line became insignificant although other responses were similarly preserved. These data imply that cardiac sympathetic stimulation decreases cardiac contractile efficiency through mechanisms by which norepinephrine-induced beta-adrenergic activation enhances myosin ATPase-operating ATP hydrolysis in crossbridge formation.

Animals↗
PubMed1998

Cloning and characterization of the azurin iso-1 gene, concerned with the electron transport chain involved in methylamine/methanol oxidation in the obligate methylotroph Methylomonas sp. strain J.

Two azurin-type blue copper proteins, which is concerned with the electron transport chain involved in methylamine/methanol oxidation, have been found in the obligate methylotroph Methylomonas sp. strain J. The azurin iso-1 gene was cloned and sequenced to analyze the role in the electron transport chain. PCR products synthesized with primers based on the N- and C-terminal amino acid sequences of azurin iso-1 were used as probes for cloning. One complete open reading frame (the azurin iso-1 gene) and one partial orf (orf1) were found in a cloned Eco105I-HindIII fragment, pMAZ3, with a total of 1066 bp. The gene encoded 148 amino acid residues. The amino acid sequence after Ala-21, deduced from the nucleotide sequence, was identical to that of the azurin iso-1 protein. The gene was in a region separate from the mau gene cluster in the chromosome. Escherichia coli expressed azurin iso-1. The results of northern blotting analysis suggested that expression of the azurin iso-1 gene is regulated by a complex regulatory network controlling oxidation of methylamine or methanol in this strain; for example, copper ions affected the expression of the azurin iso-1 gene.

Amino Acid Sequence↗
PubMed1998

Changes of hepatic tissue phospholipid peroxidation, malondialdehydes, and antioxidative enzyme activities in dogs with halothane inhalation.

To elucidate the pathogenesis of halothane-induced hepatopathy, the changes of hepatic tissue phospholipid peroxidation, malondialdehydes (MDAs), and antioxidative enzyme activities were examined in the portal vein arterialized dogs with halothane inhalation. In group A, which was given halothane inhalation under the hepatic blood flow volume less than 10% of pre-operation volume designated as a hypoxic condition, peroxidized phosphatidylcholine (PC), and free and protein-bound MDA levels significantly increased after inhalation. Although the level of protein bound MDA in group C, given hypoxic condition alone, also increased during the experimental period, the response of this was smaller than that in group A, suggesting that the halothane inhalation enhanced free radical generation under the hypoxic condition. In contrast, no significant changes of these levels were observed in groups B and D, both of which were supplied with sufficient hepatic oxygen as the normoxic condition. In addition, the significant negative correlations between hepatic oxygen supply and total or protein-bound MDA were observed in only halothane inhaled group. These findings suggested that the cause of halothane-induced hepatopathy is closely related to free radicals mainly generated from halothane anaerobic metabolism under the hypoxic condition.

Administration, Inhalation↗
PubMed1998

A case of basal cell adenocarcinoma of the parotid gland.

We present a 73-year-old female with an enlarged mass in the right parotid gland. Fine-needle aspiration cytology suggested pleomorphic adenoma. Diagnostic imaging revealed that the tumour had a well-defined margin arising from the deep lobe of the parotid gland. A total parotidectomy with preservation of the facial nerve was performed. The final histopathological diagnosis including immunohistochemical studies was basal cell adenocarcinoma, which is a recently defined entity and a rare epithelial neoplasm. No sign of local recurrence or metastasis 24 months postoperatively has been observed.

Adenocarcinoma↗
PubMed1998

Establishment of an activated macrophage cell line, A-THP-1, and its properties.

A new macrophage cell line with activated character and unique morphology was isolated by selecting adherent cells from the human monocytic cell line THP-1. The original THP-1 cells had been cultured for more than 9 years using 25 cm2 flasks, when cells with a different morphology appeared, adhering to the bottoms of the culture flasks. These were selected by discarding floating nonadherent cells at every subculture. Enrichment of adherent THP-1 cells with long processes proceeded during the cultivation. These adherent THP-1 showed remarkable phenotypic changes, not only morphologically, but also functionally. Namely, increased phagocytic activity, HLA-DR expression and MLR stimulator activity were remarkable. This adherent cell line was designated as activated-THP-1 (A-THP-1), since it demonstrated characteristics of activated macrophages continuously without exogenous stimulation. A cloned A-THP-1 cell line (A-THP-1 C1) also showed the same features and contained about 10% multinucleated giant cells probably caused by cell fusion. This A-THP-1 cell line, the first activated macrophage cell line to be established, provides a good model for understanding of activation mechanisms of macrophages and multinucleation. In this paper, morphological, immunological, and biological characters of this cell line are described.

Actins↗
PubMed1998

Organization of nitric oxide-producing nerves in the rat pyloric sphincter.

The architecture of nitric oxide (NO)-producing nerves in the rat pylorus was studied in relation to the muscular structure. The musculature of the rat pylorus was observed to be composed of two discrete muscle loops (proximal and distal sphincters). Connective tissue septa containing neural elements divided the thick musculature of the distal sphincter into many bundles. The myenteric nerve plexus of the stomach with a subpopulation of NO-producing nerves was continuous with that of the duodenum. Nitrinergic nerve fibers which originated from the antral myenteric plexus ran through the connective tissue septa in the pyloric musculature and were densely distributed on the submucosal surface of the distal sphincter. The innermost portion of the distal sphincter consisted of smooth muscle cells showing many cytoplasmic processes and abundant nitrinergic nerve terminals. This particular architecture of the nitrinergic nerves in the sphincter would seem to account for the coordinate motor function of the rat pyloric sphincter.

Animals↗
PubMed1998

Lymphatic network and nerve plexus in the myenteric layer of the monkey jejunum: a topographic study using an enzyme-histochemical method.

The topographic relationship between the lymphatic network and the nerve plexus in the myenteric layer of the monkey jejunum was studied by an enzyme-histochemical method. Identification of the lymphatics was achieved by a 5'-nucleotidase staining method, and the enteric neural components were visualized by acetylcholinesterase staining. A well-developed lymphatic network and a dense nerve plexus were demonstrated throughout the myenteric layer. Numerous segments of the initial lymphatics, with their blind endings at the apical parts, tended to gather toward the ganglion and run along the primary nerve strands. Elements of the tissue interstitium separated the lymphatics from the enteric nerves. Nerve terminals were often located closely beneath the endothelium of the initial lymphatics and were exposed to the subendothelial tissue on the side facing the abluminal surface of the lymphatic endothelium. These findings suggest that the lymph flow in the initial lymphatics might be regulated by the enteric nervous system, and that the transport of tissue fluid by the lymphatics might serve as a suitable microenvironment for the enteric nerves.

Animals↗
PubMed1998

Developmental alterations of alpha-fetoprotein sugar chain in amniotic fluids analyzed by lectin affinity electrophoresis.

Affinity electrophoresis of human alpha-fetoprotein (AFP) in amniotic fluid from pregnant women between 6 to 42 weeks of gestation and in the serum of a yolk sac tumor was performed with concanavalin A (Con A), lentil lectin (LCA), erythroagglutinating phytohemagglutinin (E-PHA) and Allomyrina dichotoma lectin (allo A). Separated AFP bands were detected by sensitive antibody-affinity blotting. In the first trimester, amniotic fluid AFP showed elevated percentages of Con A-nonreacting AFP (AFP-C1) and LCA weakly-reacting AFP (AFP-L2) as previously reported. Additionally, high percentages of E-PHA strongly-reacting AFP (AFP-P5) and E-PHA-reacting AFP (AFP-P4) were observed. E-PHA-nonreacting AFP (AFP-P1), E-PHA weakly-reacting AFP (AFP-P3f), allo A-nonreacting AFP (AFP-A1) and asialo-AFP, AFP-A1 s, were present only in amniotic fluids from 6 to 17 weeks of gestation. With advancing gestation, percentages of AFP-C1, AFP-P4 and AFP-P5 decreased and AFP-L2, AFP-P3f, AFP-A1, and AFP-A1 s disappeared by the end of 18 weeks. The glycoforms of serum AFP of the yolk sac tumor resembled those of amniotic fluid AFP in the early gestational stages.

Amniotic Fluid↗
PubMed1998

[Clinical features in patients with delayed endolymphatic hydrops].

We report clinical features in patients with delayed endolymphatic hydrops (DEH) with juvenile unilateral deafness. Among 23 patients with DEH, 15 cases were diagnosed as ipsilateral DEH and 8 cases as contralateral DEH. The distribution of onset age showed two peaks at ages of < 30 years and > 40 years. In 80% of the ipsilateral DEH cases, the onset of episodic vertigo was at younger ages. On the other hand, in 75% of the contralateral DEH cases, the onset of fluctuation hearing loss of the contralateral ear was at older ages. Ispilateral DEH and Meniere's disease may show different pathophysiologies. The incidence of dominant negative summating potential in the better-hearing ear was 20% in the ispilateral DEH cases and 60% in the contralateral DEH cases. It is suggested that endolymphatic hydrops is in the better-hearing ear of contralateral DEH.

Adult↗
PubMed1998

[Predictive factors for speech perception in patients with cochlear implant].

Cochlear implant therapy is an epoch-making advance in artificial sensory organ transplants, but the positive effects on speech perception vary. Quantification theory type I, a multivariate analysis, was used to determine predictive factors for speech perception in patients with cochlear implants. Fifty-one postlingual deaf adults (18 male and 33 female, mean age, 53.4, mean duration of deafness, 8.6 years) were tested for speech perception three or more months after a Nucleus 22 channels cochlear implant. The cause of deafness in nine patients was labyrinthitis, ototoxicity in five, meningitis in three and unknown in the remaining 34. Speech perception was measured by vowel, consonant and word recognition using a live voice, and monosyllable, word and sentence recognition using a videodisc. All tests were administered in a sound only condition. Results of the univariate analysis indicated that age at implantation was correlated with monosyllable recognition, and duration of deafness was correlated with live voice word recognition. Residual hearing and coding strategy were both correlated with all outcome measures. The multivariate analysis revealed that coding strategy, duration of deafness, residual hearing and the number of electrodes were significant predictors of live voice word recognition in that order.

Adolescent↗
PubMed1998

[Molecular dynamics of human intrafollicular plasma kallikrein and the mechanism of activation of tissue-type plasminogen activator (tPA) in ovarian follicles].

Tissue-type plasminogen activator (tPA)/plasmin system is generally believed to play an important role in follicle wall degradation upon ovulation. For examination of the proteolytic activation of tPA within the follicle, human plasma kallikrein (hPK) was purified from preovulatory follicular fluid obtained from women hyperstimulated by GnRHa-hMG-hCG in in vitro fertilization procedures. After ammonium sulfate fractionation, three enzyme fractions were isolated in the DEAE-cellulose ionic exchange column chromatography. Each fraction was further purified by various column chromatographies using CM-cellulose, benzamidine-Sepharose 6B, heparin-Cellulofine, and Sephacryl S-300. Enzymatic (substrate specificity, susceptibility to various proteinase inhibitors), electrophoretic, and immunological characterization of the enzymes revealed that they were hPK in free form (Mr = 89,000-90,000), in complex with alpha 2-macroglobulin (Mr = 730,000), and a newly-found isoform of pPK (Mr = 80,000-87,000). Each fraction was capable to convert human single-chain tPA (sctPA) to its active two-chain form. The present data also demonstrates that the activation of tPA by the alpha 2-macroglobulin fraction is due to the action of a bound proteinase distinct from hPK, indicating the presence of an additional tPA activator. These proteinases are presumably involved in triggering of the tPA/plasmin system by activating tPA upon ovulation.

Cells, Cultured↗
PubMed1998

A close correlation between c-erbB-2 gene amplification and local progression in endometrial adenocarcinoma.

The c-erbB-2 proto-oncogene is a gene that encodes a growth factor receptor-like molecule with tyrosine kinase activity. The purpose of this study was to determine whether c-erbB-2 gene amplification measured by the simple and sensitive differential polymerase chain reaction (PCR) method correlates with clinicopathological factors in endometrial adenocarcinomas. Overall, 7 out of the 38 endometrial adenocarcinomas (18.4%) displayed amplified c-erbB-2 oncogene. No correlation between c-erbB-2 gene amplification and FIGO stage, histologic grade or existence of metastatic disease was found. There was a significant association between c-erbB-2 gene amplification and deep myometrial invasion. In the current study, it has been suggested that c-erbB-2 gene amplification is possibly involved in local progression but is not closely related to the loss of cell differentiation and metastasis.

Adenocarcinoma↗