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Biomedical subjects

T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 595 records · Page 33Linked to original sources
PubMed1989

[Causalgia in the upper limbs following neck trauma: existence of widespread dysfunction of sympathetic postganglionic fibers].

The functions of autonomic nervous system were systematically evaluated in a case of causalgia in the upper limbs after neck trauma. A 14-year-old boy had had hard blow on his nucha in a rough fight. After one week, a sustained burning pain, swelling and skin color change developed in the left upper limb. These symptoms also appeared in the right upper limb after 6 weeks. The physical examinations disclosed edema, reddish moist skin, and atrophic nail in the upper limbs. The neurological examinations showed a radiating pain to the upper limbs caused by the neck movement or pressure on the supraclavicular fossae, weakness of the upper limbs and left lower limb, and loss of sensation in the 5th to 8th cervical and first thoracic dermatomal segments. Deep tendon reflexes were diminished in the upper limbs and exaggerated in the lower limbs. Neither Horner syndrome nor sphincter disturbance was observed. He was diagnosed as being the cervicothoracic radiculopathy and cervical myelopathy due to the mechanical force. The burning pain disappeared with oral administration of guanethidine. On the examinations of the autonomic functions, the sweating response to the thermal stimulation was absent above the 5th thoracic dermatomal segment. The sweating response to the intradermal acetylcholine was decreased in the second and third thoracic dermatomal segments. The systolic hypotension with increasing pulse rate occurred on standing. The reactive elevation of the blood pressure to the intravenous tyramine was absent. The excessive elevation of the systolic blood pressure was induced by the subcutaneous injection of epinephrine. These results indicated the dysfunction of the sympathetic postganglionic sudomotor and vasomotor fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Clinical studies on cefixime in pediatrics].

Clinical usefulness of cefixime (CFIX), a new oral cephalosporin antibiotic, in pediatric field was investigated. The results obtained were summarized as follows. 1. The clinical efficacy of CFIX was investigated in a total of 138 children including 49 with upper respiratory tract infections (RTI), 22 with acute bronchitis, 18 with pneumonia, 19 with scarlet fever and 21 with urinary tract infections (UTI). 2. Clinical effectiveness was excellent in 58, good in 60, fair in 14 and poor in 3, with an overall efficacy rate of 87.4%. The efficacy rate classified according to types of infection were 85.7% in upper RTI, 89.5% in acute bronchitis, 94.4% in pneumonia, 78.9% in scarlet fever, and 90.5% in UTI. 3. Out of the suspected causative organisms, 43 strains of a total of 50 strains isolated were eradicated. The bacteriological eradication rate was 86.0%. (Haemophilus influenzae 100%, Haemophilus parainfluenzae 100%, Streptococcus pyogenes 88.5%, Escherichia coli 85.7%). 4. One hundred forty four children were analyzed for side effect. Side effects were observed in 2 children (1.4%) with diarrhea in 1 and anorexia in another. Abnormal laboratory test results were recorded in 4 children (3.3%). The above results suggest that CFIX is a very useful new oral cephalosporin for the treatment of bacterial infections in children.

Adolescent↗
PubMed1989

[Flexion myelopathy due to tic of neck].

A 22-year-old male developed a tic of neck-flexion at the age of 14. The tic occurred 40 to 50 times per minute on its peak at age 16. Since then he noticed the atrophy and weakness of his both upper limbs. His right leg became weak at age 22. On admission, neurological examination revealed tic of lip and neck, severe muscle atrophy and weakness of bilateral upper limbs, mild muscle weakness and spasticity of right lower limb and hyperreflexia in four limbs. Needle EMG studies revealed fibrillation, positive sharp wave and giant MUP in the biceps, triceps and first interossei muscles. There were no abnormal findings suggesting cervical spondylosis or disc herniation on neck roentgenogram and neck MRI in neutral position. Neck MRI in the ventro-flexed position showed a flattening of the lower cervical cord and a band-like isointensity lesion in the posterior epidural space at C4-6. This isointensity lesion was considered to represent a congestion of the internal vertebral venous plexus. These findings suggest that frequent neck flexion by itself causes the injury of the lower cervical cord through (1) over-stretching of the cord, (2) compression of the cord by dural sac, (3) arterior ischemia, and/or (4) stagnant hypoxia due to venous congestion. Flexion myelopathy may represent one of the most important mechanisms of cervical cord injury accompanied with involuntary movement of neck.

Adult↗
PubMed1989

[Scimitar syndrome with left pulmonary hypertension and right pulmonary artery stenosis in childhood--report of a case of successful surgical repair].

An one-year old child with Scimitar syndrome (anomalous drainage of the right pulmonary vein to inferior vena cava with right lung hypoplasia) associated with left side pulmonary hypertension and right pulmonary artery stenosis underwent surgical repair. The anomalous pulmonary vein was anastomosed to right atrium with 10 mm PTFE graft interposition and drained to left atrium through equine pericardial intra-atrial baffle. The stenotic portion of right pulmonary artery was enlarged with porcine pericardial patch. To our knowledge, this is the first successful surgical case of Scimitar syndrome with pulmonary hypertension in childhood reported in literature. A repair of anomalous pulmonary venous drainage to inferior vena cava in childhood is difficult, and a meticulous selection of surgical procedure is necessary.

Blood Vessel Prosthesis↗
PubMed1989

[Myocardial infarctectomy in the acute stage].

Seven patients with ventricular septal perforation or left ventricular free-wall rupture underwent myocardial resection in the acute stage of myocardial infarction. One of them received direct closure of the left ventricle, and the others replacement of myocardium with a Dacron prosthesis. One patient died of cardiac failure 5 days after surgery, and 4 in the late-stage between 2 months and 4 years. The following conclusions are obtained in our patients: 1. Echocardiography is very important for the diagnosis of cardiac free-wall rupture and determination of emergency surgery. 2. An intra-aortic balloon should be inserted in patients with VSP as soon as possible. If general state of the patients had been improved by the procedure, surgery might be withheld until the recovery, otherwise emergency surgery should be considered. 3. Myocardial replacement with a prosthesis seems to be useful when the left ventricular cavity is predicted to be small after resection of the myocardium. 4. The development of assisted circulation would improve a survival rate after the surgery. 5. Systemic managements are also important because the patients sometimes become fatal by non-cardiac complications even if they have survived from circulatory failure.

Aged↗
PubMed1988

Proteasomes (multi-protease complexes) as 20 S ring-shaped particles in a variety of eukaryotic cells.

Latent multicatalytic protease complexes, named proteasomes, were purified to apparent homogeneity from various eukaryotic sources, such as human, rat, and chicken liver, Xenopus laevis ovary, and yeast (Saccharomyces cerevisiae), and their functional and structural properties were compared. They showed latency in breakdown of [methyl-3H]casein, but were greatly activated in various ways, such as by addition of polylysine. They all degraded three types of fluorogenic oligopeptides at the carboxyl side of basic, neutral, and acidic amino acids, and the three cleavage reactions showed different spectra for inhibition, suggesting that they had three distinct active sites. The proteasomes all seemed to be seryl endopeptidases with similar pH optima in the weakly alkaline region. Their physiochemical properties, such as their sedimentation coefficients (19 S to 22 S), diffusion coefficients (2.0-2.6 X 10(-7) cm2 s-1), molecular masses (700-900 kDa), and circular dichroic spectra, were similar. Their amino acid compositions were also very similar. Electron microscopy showed that they had similar well-defined symmetrical morphology, appearing to be ring-shaped particles with a small hole in the center. All the proteasomes seemed to be multisubunit complexes consisting of 15-20 polypeptides with molecular masses of 22-33 kDa and isoelectric points of pH 3-10, but they showed species-specific differences in subunit multiplicity. Moreover, they differed immunologically, as shown by Ouchterlony tests and immunoblotting analyses, although cross-immunoreactivities of some subunits or domains were observed. These results indicate that the sizes and shapes of these proteasomes have been highly conserved during evolution, but that they show species-specific differences in immunoreactivities and subunit structures. Thus proteasomes with similar structure and function seem to be ubiquitously distributed in eukaryotic organisms ranging from man to yeast. This distribution implies the general importance of these proteasomes for proteolysis.

Amino Acids↗
PubMed1988

General kinetic model for protein-mediated phospholipid transfer between membranes.

Phospholipid transfer protein catalyzes the transfer of phospholipids between bilayer membranes. A general model is developed for describing the kinetics of this process. While previous models derive detailed expressions only for the initial rate of transfer from donor to acceptor membranes, this model takes into account donor-to-donor, acceptor-to-acceptor, and acceptor-to-donor transfers, in addition to the usual donor-to-acceptor transfer. The apparent rate of transfer along any of these specific routes is given as the product of the total rate of transfer (the sum of the rates of transfer along all four routes) and a probability function uniquely defined for each route. The model explains adequately the effects of membrane concentration on phospholipid transfer activity as well as the consequences of varying membrane surface charge and size. Using bovine liver phosphatidylcholine transfer protein, the model is applied to the kinetic analysis of phosphatidylcholine transfer between two populations of small unilamellar vesicles. Rates of protein-catalyzed phosphatidylcholine transfer between vesicles with identical phosphatidic acid content (2 or 6 mol%) are determined experimentally as a function of total vesicle concentration to calculate apparent dissociation constants and maximum rates of transfer; apparent rates of transfer between various combinations of vesicles containing 2 or 6 mol% phosphatidic acid are then deduced from the derived velocity expression. Reasonably good agreement is seen between theoretical apparent rate-vesicle concentration relationships and those measured experimentally. The results support the general treatment of the kinetics of protein-mediated phospholipid transfer and permit an estimation of useful kinetic parameters.

Animals↗
PubMed1988

Molecular organization of a high molecular weight multi-protease complex from rat liver.

A latent multifunctional protease with a molecular weight of 722,000 to 760,000 purified from rat liver cytosol has been reported. This paper reports on the structure and subunit composition of the enzyme. Electron microscopy showed that the enzyme was a ring-shaped particle of 160(+/- 7) A diameter and 110(+/- 10) A height with a small hole of 10 to 30 A diameter (1 A = 0.1 nm). Small-angle X-ray scattering analysis indicated that the enzyme had a prolate ellipsoidal structure with an ellipsoid cavity in the center. The maximum dimension of the enzyme was estimated to be 210 A from a pair-distance distribution function. The radius of gyration obtained from a Guinier plot and the Stokes radius based on the ellipsoidal model were 66 A and 76 A, respectively. On two-dimensional gel electrophoresis, the purified enzyme separated into 13 to 15 characteristic components with molecular weights of 22,000 to 33,000 and isoelectric points of 4 to 9. These multiple components were not artifacts produced by limited proteolysis during purification of the enzyme, because the cell-free translation products in a reticulocyte lysate with poly(A)-mRNA of rat liver consisted of multiple components of similar sizes, and because peptide mapping analyses with lysylendopeptidase and V8 protease demonstrated clear differences in the primary structures of these components. The 13 main components were isolated from the purified enzyme by reverse-phase high performance liquid chromatography and shown to be non-identical. A model of the enzyme is proposed on the basis of these observations and previous physicochemical studies. Interestingly, the morphology of this protease is similar to that of the 16 to 22 S ring-shaped particles found in a variety of eukaryotic organisms. The structural similarity between this multi-protease complex and various reported subcellular particles is discussed.

Animals↗
PubMed1988

Synthesis and biological characterization of monocyte-derived neutrophil chemotactic factor.

MDNCF is a human monocyte-derived, 72-residue chemotactic peptide, which has sequence similarity with members of a family of pro-inflammatory cytokines. The peptide was synthesized by the solid-phase method, and is identical to the natural peptide in amino acid composition, sequence and chemotactic potency. MDNCF forms two loops via a neighboring pair of disulfide bridges, the probable locations of which are residues 7-34 and 9-50. Reduction and alkylation eliminated chemotactic activity. MDNCF fragments 7-37, 30-72 and 17-72 were all biologically inactive. The data suggest that the region of the clustered pair of disulfide bridges is important for biological activity.

Alkylation↗
PubMed1988

A change in the heme stereochemistry of cytochrome c upon addition of sodium dodecyl sulfate: electron paramagnetic resonance and electronic absorption spectral study.

Electron paramagnetic resonance and electronic absorption spectral changes upon addition of sodium dodecyl sulfate (SDS) to ferric and ferrous cytochrome c have been measured at 77 degrees K and at room temperature. The spectral changes upon addition of SDS to ferric cytochrome c were performed, in two steps, from native low-spin to another low-spin spectrum and subsequently to high-spin-like spectrum. On the other hand, the spectral changes upon addition of SDS to ferrous cytochrome c proceeded, in one step, from native low-spin to high-spin spectrum. The high-spin-like spectrum of ferric cytochrome c and the high-spin spectrum of ferrous cytochrome c in the presence of high concentrations of SDS are, respectively, apparently similar to those of ferric and ferrous cytochrome c' at physiological pH in spectral features. These spectral similarities suggest the similarities in the heme stereochemistry and the ground state of heme iron. Further, the spectra of cytochrome c in the presence of SDS varied with the change of pH values. The ferric high-spin-like and ferrous high-spin spectra were stable at neutral pH and below it. Conformational changes of cytochrome c upon addition of SDS are also discussed.

Cytochrome c Group↗
PubMed1988

The mechanism for the inhibitory action of N-(3',4'-dimethoxycinnamoyl)anthranilic acid (tranilast) on the release reaction in platelets.

The molecular basis for the inhibitory action of the antiatopic drug, N-(3',4'-dimethoxycinnamoyl)anthranilic acid (Tranilast), on the thrombin-induced release of a lysosomal enzyme, beta-N-acetylglucosaminidase, from washed rabbit platelets was investigated. Tranilast dose dependently increased cyclic AMP and cyclic GMP levels in thrombin-stimulated platelets, parallel with the inhibition of beta-N-acetylglucosaminidase release. There was no significant effect of Tranilast on adenylate or guanylate cyclase activity. Tranilast inhibited the activity of cyclic AMP and cyclic GMP phosphodiesterases in a cell-free system. The data suggest that the inhibitory action of Tranilast on the release reaction in platelets was due at least in part to inhibition of cyclic nucleotide phosphodiesterases followed by an elevation of cyclic AMP and cyclic GMP levels.

Acetylglucosaminidase↗
PubMed1988

Molecular cloning of a human monocyte-derived neutrophil chemotactic factor (MDNCF) and the induction of MDNCF mRNA by interleukin 1 and tumor necrosis factor.

The cDNA coding for human monocyte-derived neutrophil-specific chemotactic factor (MDNCF) was cloned from LPS-stimulated human monocyte mRNA. The cDNA sequence codes for a polypeptide consisting of 99 amino acids, including a putative signal sequence. Comparison of the deduced amino acid sequence with the NH2-terminal amino acid sequence of natural MDNCF shows that the mature functional protein comprises 72 amino acids, beginning with serine at residue 28. The deduced amino acid sequence shows striking similarity to several platelet-derived factors, a v-src-induced protein, a growth-regulated gene product (gro), and an IFN-gamma inducible protein. The availability of the MDNCF cDNA enabled us to use it as a probe to identify inducers of MDNCF mRNA expression in human PBMC. MDNCF mRNA was increased greater than 10-fold within 1 h after stimulation with LPS, IL-1, or TNF, but not by IFN-gamma, IFN-alpha, or IL-2. Furthermore, we also determined that LPS, IL-1, and TNF stimulated the mononuclear cells to produce biologically active MDNCF. This observation may account for the in vivo capacity of IL-1 and TNF to induce netrophil infiltrates.

Amino Acid Sequence↗
PubMed1988

[Epidemiological study on socio-psychological factors to affect the change in life style].

A cohort with the general population of 5698 was established to clarify the association between individual life style and health. This study investigated the association between life style and socio-psychological factors by means of a cross-sectional study of 1005 males aged 30 to 59 years. The health practice index consisted of 5 health practices, 1) smoking 2) drinking 3) physical activity 4) Quetelet's index, and 5) sleep. The subjects were divided into two groups, group I (aged 30 to 44 years) and group II (aged 45 to 59 years). Path analysis was used to clarify the relationship between various socio-psychological factors relating to the health practice index. In group I, the health locus of control and perceived daily life stress were directly related to the health practice index. In group II, the only health locus of control was directly related to the health practice index. It was found that the social support network formed the basis of these two factors. These results suggested that it is very important to consider individual socio-psychological factors when promoting good health practice.

Adult↗
PubMed1988

Theoretical analysis of a site-specific chemiluminescence reaction and its application to quantitation of lipid hydroperoxides.

A system was designed for chemiluminescent measurement of lipid hydroperoxides by their site-specific reaction in sodium dodecylsulfate micelles. Ferrous ion-induced decomposition of lipid hydroperoxides in the sodium dodecylsulfate micelles resulted in strong chemiluminescence of the Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (CLA). After addition of ferrous sulfate to the micelles containing lipid hydroperoxide and luciferin, the chemiluminescence intensity reached a maximum rapidly and then decreased. The sequence of this reaction was elucidated by theoretical analysis, which demonstrated that the maximum chemiluminescence intensity is proportional to the initial concentration of hydroperoxide. Good linear relationships were observed between the maximum counts of chemiluminescence and the amounts of hydroperoxides of linoleic acid, phosphatidylcholine, choresterol (5 alpha), cumene and tert-butyl and hydrogen peroxide. This chemiluminescence method was simple and sensitive enough to detect picomole levels of linoleic acid and phosphatidylcholine hydroperoxides.

Binding Sites↗
PubMed1988

Serum lactic dehydrogenase and its isoenzymes in patients with ovarian dysgerminoma.

Lactic dehydrogenase (LDH) is a glycolytic enzyme that may be elevated in the serum of patients with gonadal and extragonadal germinomas. In this report, a case of unilateral ovarian pure dysgerminoma with remarkably elevated levels of serum LDH is presented. After complete excision of the tumor, serum LDH levels promptly returned to normal levels. Although an electrophoretic pattern of serum LDH isoenzymes was within normal limits pre-operatively, an increase in LDH-1 and 2 was found 1 week after operation. Seventeen additional examples of ovarian dysgerminomas with elevated serum LDH levels have been reported in the English literature including five cases who had high levels of two fast fractions of LDH. These data suggest that serum LDH levels and its isoenzymes pattern are useful tumor markers for diagnosis and post-therapy surveillance in patients with ovarian dysgerminomas.

Adolescent↗
PubMed1988

Effects of pregnancy and hormone treatments on pressor response to angiotensin II in conscious rats.

Pressor responses to graded doses of angiotensin II in conscious rats were significantly reduced on days 13 and 19 of pregnancy compared with those in nonpregnant rats. To study the hormonal regulation of this altered pressor response to angiotensin II during pregnancy, we administered estradiol, progesterone, and human chorionic gonadotropin to nonpregnant rats. In ovariectomized rats no effect of estradiol on the pressor response to angiotensin II was found, but injections of progesterone with or without estradiol pretreatment significantly reduced the pressor response to angiotensin II. In intact rats human chorionic gonadotropin induced elevation of endogenous progesterone levels, followed by a significant decrease in the pressor response to angiotensin II. Injection of estradiol after human chorionic gonadotropin pretreatment produced a significant elevation in the pressor response to angiotensin II. These findings indicate that the decrease in angiotensin pressor response in pregnant rats is mediated mainly by progesterone rather than by estrogen.

Angiotensin II↗
PubMed1988

Nitric oxide complex of cytochrome c' in cells of denitrifying bacteria.

Electron paramagnetic resonance (EPR) spectra at 77K have been measured for the dried cells of three groups of chemoheterotrophic bacteria cultured in the presence of nitrate: I, denitrifying bacteria containing cytochrome c' (Alcaligenes sp. NCIB 11015, Achromobacter xylosoxidans GIFU 543); II, denitrifying bacteria in which cytochrome c' has not been found (Alcaligenes faecalis IAM 1015, Bacillus firmus NIAS 237, Pseudomonas stutzeri ATCC 17641); III, non-denitrifying bacterium containing cytochrome c' (A. xylosoxidans GIFU 1055). A characteristic three-line EPR signal was detected only in the dried cells of group I, and was assigned to NO-cytochrome c' complex. The probable physiological role of the cytochrome c' in denitrifying bacteria is discussed.

Bacteria↗