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Biomedical subjects

M Yoshida

Publications and source records attributed to M Yoshida.

At least 1,297 records · Page 72Linked to original sources
PubMed1995

Structures of cDNAs encoding the muscle-type and non-muscle-type isozymes of lamprey fructose bisphosphate aldolases and the evolution of aldolase genes.

Nearly full-length cDNA clones for muscle-type and non-muscle-type aldolase mRNAs were cloned from lambda gt10 cDNA libraries constructed from skeletal muscle and liver mRNAs of lamprey (Entosphenus japonicus). The cDNA-M8 has 2,240 bp carrying an open reading frame of 1,089 bp which encodes 362 amino acids without the amino terminal methionine, while the cDNA-L3 is 1,761 bp in length and has an open reading frame of 1,092 bp, which encodes 363 amino acids without the methionine. We designated the cDNA clones M8 and L3 as the muscle-type and non-muscle-type aldolase cDNAs, respectively. The entire amino acid sequences deduced from cDNA-M8 and -L3 show a high degree of identity to one another (76%) and also to vertebrate aldolases A (74-76%), B (68-70%), and C (71-76%) and Drosophila melanogaster aldolases alpha, beta, and gamma (66-67%). Northern blot analyses using the 3'-noncoding sequences of cDNA-M8 and -L3 as hybridization probes indicated that the muscle-type mRNA is expressed mainly in the skeletal muscle, heart muscle, brain, and some other tissues, but probably not in liver, while the non-muscle-type mRNA is expressed mainly in the liver and also in brain and other tissues, except for the heart muscle. Phylogenetic analyses showed that both muscle-type and non-muscle-type aldolases of lamprey resemble one another and might share a common ancestor with vertebrate aldolases A and C, but they are not direct ancestors of vertebrate aldolases.

Amino Acid Sequence↗
PubMed1995

Morphology of ras-transformed cells becomes apparently normal again with tyrosine kinase inhibitors without a decrease in the ras-GTP complex.

Radicicol, an inhibitor of protein-tyrosine kinase, was found to cause morphological reversion of v-Ha-ras-transformed NIH3T3 fibroblasts and T24 human urinary bladder carcinoma cells that contain an activated ras mutation. The network of actin stress fibers was restored during the treatment with radicicol. A similar morphological change was observed with another protein-tyrosine kinase inhibitor, herbimycin A. Radicicol did not cause any changes in the proportion of the active GTP binding form of p21ras or its subcellular localization. These results rule out the possibility that the morphological reversion by radicicol is due to direct or indirect inhibition of the p21ras function. Cycloheximide and actinomycin D inhibited the morphological change by radicicol, suggesting that the induced transcription of a gene(s) followed by de novo protein synthesis is required for suppression of the transformed phenotype in ras-transformed cells by tyrosine kinase inhibitors.

Animals↗
PubMed1995

Molecular cloning, expression, and characterization of chaperonin-60 and chaperonin-10 from a thermophilic bacterium, Thermus thermophilus HB8.

The gene coding a chaperonin from a thermophilic bacterium, Thermus thermophilus HB8, was cloned and sequenced. The operon structure was the same as those of other bacterial chaperonins and the deduced amino acid sequences of both subunits were highly homologous to those of other chaperonins. The cloned genes of chaperonin subunits, chaperonin-10 (T.th cpn10) and chaperonin-60 (T.th cpn60), were separately expressed in Escherichia coli cells. The expressed subunits were easily purified from other host proteins including GroE, a chaperonin of E. coli. T.th cpn60 was expressed as a tetradecameric form, like GroEL of E. coli. Since chaperonin from T. thermophilus HB8 is purified as a holochaperonin, a complex of tetradecameric T.th cpn60 and heptameric T.th cpn10, a tetradecamer of T.th cpn60 without T.th cpn10 has not been obtained before. T.th cpn60 tetradecamer tended to dissociate into monomers during storage. T.th cpn10 expressed in E. coli was purified as a stable oligomer, most likely a heptamer. The activity as holo-chaperonin was reconstituted by mixing both subunits. T.th cpn60 tetradecamer itself arrested refolding of other proteins. The monomerized T.th cpn60 was easily purified from T.th cpn60 oligomer by gel permeation chromatography. Thus-obtained T.th cpn60 monomer had an ATP-independent chaperone activity, as shown for T.th cpn60 monomer isolated from authentic holo-chaperonin.

3-Isopropylmalate Dehydrogenase↗
PubMed1995

Acquired von Willebrand disease associated with multiple myeloma; characterization of an inhibitor to von Willebrand factor.

Acquired von Willebrand disease (vWD) has been described in a few patients with multiple myeloma. The present study characterizes an inhibitor of von Willebrand factor (vWF) isolated from a patient with multiple myeloma (IgG-kappa). Multimeric analysis of vWF from this patient's plasma showed a reduction in multimers of all sizes. The inhibitor (IgG) detected only the vWF subunit from plasma of normal individuals. It reacted with intact vWF subunit and a 39/34kDa dispase-digested fragment of vWF (residues; Leu480/Val481-Gly718), but did not react with platelet membrane glycoproteins (GPs) or adhesive proteins. The binding of vWF to GPIb mediated by ristocetin and by botrocetin was inhibited by the patient's IgG with an IC50s of 0.3 mg/ml and 0.48 mg/ml, respectively. The platelet aggregation induced by ristocetin or botrocetin was also inhibited by the IgG. These results indicate that this inhibitor may recognize the binding region of vWF to GPIb. Therefore, the antibody to vWF appears to represent the likely pathophysiological mechanism responsible for the acquired vWD in this patient.

Autoantibodies↗
PubMed1995

A large-scale, hospital-based case-control study of risk factors of breast cancer according to menopausal status.

We conducted a large-scale, hospital-based case-control study to evaluate differences and similarities in the risk factors of female breast cancer according to menopausal status. This study is based on a questionnaire survey on life style routinely obtained from outpatients who first visited the Aichi Cancer Center Hospital between January 1, 1988 and December 31, 1992. Among 36,944 outpatients, 1,186 women with breast cancer detected by histological examination were taken as the case group (607 premenopausal women and 445 postmenopausal women) and 23,163 women confirmed to be free of cancer were selected as the control group. New findings and reconfirmed factors of breast cancer were as follows. 1) The risk of at least one breast cancer history among subjects' first-degree relatives was relatively high among pre- as well as post-menopausal women. 2) A protective effect of physical activity against breast cancer was observed among both pre- and post-menopausal women. 3) Dietary control decreased the risk of premenopausal breast cancer. 4) Current smoking and drinking elevated the risk of breast cancer in premenopausal women. 5) Decreasing trends of breast cancer risk were associated with intake of bean curd, green-yellow vegetables, potato or sweet potato, chicken and ham or sausage in premenopausal women, while in postmenopausal women a risk reduction was associated with a more frequent intake of boiled, broiled and/or raw fish (sashimi). Further study will be needed to clarify the age group- and/or birth cohort-specific risk factors for breast cancer among the young generation in Japan.

Adult↗
PubMed1995

Exanthem subitum (roseola infantum) with vesicular lesions.

We report a 7-month-old boy who developed vesicular lesions during the course of exanthem subitum. Human herpesvirus-6 (HHV-6) DNA was detected both in the skin lesions and in the throat, by polymerase chain reaction. IgG and IgM antibodies against HHV-6 were 1:10 and < 1:10, respectively on the tenth day of the illness, and > 1:640 and 1:10 on the twenty-second day, respectively. These results suggest that this was primary HHV-6 infection.

Antibodies, Viral↗
PubMed1995

Effect of renal nerve denervation on tissue catecholamine content in spontaneously hypertensive rats.

1. To clarify the possible role of tissue catecholamines in the development of hypertension, we investigated the effect of bilateral renal denervation on the catecholamine contents of central and peripheral tissues in spontaneously hypertensive rats (SHR). 2. Norepinephrine (NE) content in renal cortex, renal medulla, and adrenal gland was higher in 7 week old SHR than age-matched Wistar-Kyoto rats (WKY). Dopamine (DA) content in the brainstem and hypothalamus was also higher in SHR, but NE and epinephrine (EPI) content in these areas were not different between strains. Similar differences in catecholamines were observed in 9 week old rats in which a sham operation of bilateral renal denervation was performed 2 weeks previously. 3. Bilateral renal denervation produced an almost complete reduction of NE content in the kidney in both strains and prevented the development of hypertension. DA content in the brainstem was also decreased by renal denervation in SHR but not in WKY. NE and EPI content in central tissues were not affected by renal denervation. 4. These results suggest that DA content in brainstem area, as well as NE content in the kidney, have a relationship in the development of hypertension in SHR.

Animals↗
PubMed1995

Application of a new perchloric acid treatment method to measure endotoxin by an endotoxin-specific chromogenic Limulus test in neonatal septicemia.

The endotoxin in blood was measured to establish both the cut-off value and to detect Gram-negative septicemia. We employed a new perchloric acid treatment method using an endotoxin-specific chromogenic Limulus test (Endospecy test). The cut-off value of endotoxin in blood was 11.2 pg/mL. All cases of septicemia (n = 7) showed high values of endotoxin. Three cases were Group B streptococci, and two cases were Escherichia coli. The others were showed to be negative in blood cultures. The paired values of endotoxin titers during a 48 h interval were useful to evaluate the effectiveness of antibiotics.

Bacteremia↗
PubMed1995

Methicillin-resistant Staphylococcus aureus: colonization and development of infection in patients with haematological disorders.

A retrospective study of 53 patients with haematological disorders whose bacterial cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA), was performed to analyse the risk factors for MRSA infection, and the prognostic factors. Sixteen patients showed colonization by MRSA but never developed infection(C), 16 showed colonization and subsequent infection(C-I), while 21 had MRSA infection at the time of first culture (I). Poor performance status, thrombocytopenia, increased serum urea nitrogen and decreased serum cholinesterase were more prominent in (I) than (C) + (C-I). The risk factors associated with the development of infection from colonization were age and serum cholinesterase. In addition, lower respiratory tract infection as a type of infection, non-remission status of the haematological malignancy and an inappropriate antibiotic therapy were associated with a poor prognosis for MRSA infection.

Blood Urea Nitrogen↗
PubMed1995

Characteristics of multimodal co-aggregation between Fusobacterium nucleatum and streptococci.

The co-aggregation characteristics between Fusobacterium nucleatum and streptococci were examined to clarify the adherence factors participating in the co-aggregation. Nineteen strains of F. nucleatum were classified into 8 groups according to co-aggregation titer and inhibition by L-arginine, L-lysine and N-acetyl-D-galactosamine (or lactose). The inhibition activity was, however, very different from strain to strain. With two fusobacterial strains, two inhibitors, which were both inhibition negative on their own, completely inhibited the co-aggregation when used together in a mixture. In some co-aggregation pairs, the protease treatment of F. nucleatum inactivated one of the adherence factors, and resulted in the change of inhibition characteristics. These results indicate the multimodal co-aggregation of F. nucleatum with streptococci mediated by L-arginine-sensitive, L-lysine-sensitive, N-acetyl-D-galactosamine-sensitive and in some resistant factors, and that the adherence factor or factors participating the co-aggregation change according to the co-aggregation partners.

Acetylgalactosamine↗
PubMed1995

Cardiovascular effects of NT-1, a new patch form of nitroglycerin, alone and in combination with nifedipine in conscious dogs.

The cardiovascular effects of NT-1, a new patch form of nitroglycerin, alone and in combination with nifedipine in conscious dogs were examined. NT-1 (2.5 mg kg-1 nitroglycerin) decreased systolic blood pressure by 10-15%, while diastolic blood pressure and heart rate were not affected. Coronary blood flow and calculated rate-pressure product were decreased. These parameter changes occurred at 30 min after NT-1 application and remained constant for 8 h until NT-1 was removed. After administration of NT-1 in combination with nifedipine, systolic blood pressure was significantly decreased to a greater extent, and heart rate and coronary blood flow showed a tendency to increase compared with nifedipine alone. Rate-pressure product was not changed compared with that obtained on administration of nifedipine alone. These results suggest that NT-1 may be applicable as a transdermal sustained release medication, and show that in combination with nifedipine, NT-1 can induce a large increase in coronary blood flow without further increasing rate-pressure product.

Administration, Cutaneous↗
PubMed1995

[Usefulness of endotoxin-specific limulus test for the measurement of endotoxin in cerebrospinal fluid in diagnosis of bacterial meningitis].

Using a new endotoxin-specific chromogneic limulus assay (Endoscopy test), endotoxin concentrations were measured in 93 specimens of cerebrospinal fluid (CSF) from 66 pediatric patients. Eighteen patients were diagnosed as having menigitios. Of these, 6 cases (group A) with gram-negative meningitis proven by culture had high CSF endotoxin concentrations of 115.3, (82-133) (median, range) pg/ml. Ten cases (group B) with gram-positive or aseptic meningitis had endotoxin concentrations of 2.15 (0.1-3.6) pg ml. Other 2 cases with bacterial meningitis (group C), in whom no pathogen was detected, had CSF endotoxin concentrations of more than 100 pg/ml. Four cases with encephalitis (group D) and 45 cases with non-meningitis or non- encephalitis (group E), had CSF endotoxin concentrations of less than 5 pg/ml. Despite a negative culture after antibiotic treatment in group A patients, endotoxin was cleared slowly from the CSF. A clearing of endotoxin from CSF was followed by alleviation of fever with a more gradual decline in CRP values. In 2 cases of group C, the negative bacterial culture appeared to be attributable to the previous treatment with antibiotics. However, these patients had high CSF endotoxin levels, indicating gram negative bacterial meningitis. In 17 CSF specimens from 5 patients of group A, in whom Haemophilus influenzae was detected on admission, an additional a latex agglutination test for the detection of H. influenzae polysaccharide antigen was performed. Only 3 specimens from 3 patients with CSF endotoxin concentrations of more than 80 pg/ml had a positive agglutination test. These results suggest that quantitation of endotoxin concentrations is useful for the diagnosis of gram-negative meningitis. And also, the clearance of endotoxin from CSF during treatment appears to be useful in determining the timing of when antibiotic should be stopped.

Adolescent↗
PubMed1995

[Pathogenic bacteria isolated from the sputum of the patients with pulmonary emphysema].

Isolated pathogenic bacteria from sputum of the patients with pulmonary emphysema who were admitted in our hospital from 1984 to 1994 were examined to elucidate the relationship between isolated bacteria from sputum and pulmonary functions including vital capacity (VC), forced expiratory volume (FEV1.0), PaO2 and PaCO2. VC of the patients from whom MSSA (methicillin-sensitive Staphylococcus aureus) or Enterococcus faecalis (E. faecalis) were isolated was significantly lower than that of the patients from whom Streptococcus pneumoniae (S. pneumoniae), Branhamella catarrhalis (B. catarrhalis) or Haemophilus influenza (H. influenza) were isolated. FEV1.0 had a similar tendency as VC in terms of isolated organisms from the patients with emphysema. Similarly, PO2 of the patients from whom MSSA or E. cloacae were isolated was significantly lower than that of the patients from whom S. pneumoniae, B. catarrhalis or H. influenzae were isolated, and PCO2 of the patients from whom S. pneumoniae, B. catarrhalis or H. influenza were isolated. There was also impaired respiratory function in the patients from whom MSSA, Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Xanthomonas maltophilia (X. maltophilia) or Enterobacter cloacae (E. cloacae) were isolated, compared with those in the patients from whom S. pneumonia, B. catarrhalis or H. influenzae were isolated. These results suggest that isolated pathogenic bacteria are shifted from S. pneumoniae, B. catarrhalis or H. influenza to MSSA, E. coli, P. aeruginosa, X. maltophilia or E. cloacae in the course of impairment of respiratory function in pulmonary emphysema. The treatment and prophylaxis for acute exacerbation in pulmonary emphysema should be based on these results.

Bacteria↗
PubMed1995

[Efficacy of combination chemotherapy with miconazole and G-CSF in deep mycosis accompanying hematological diseases].

In order to examine the efficacy of the combination chemotherapy with miconazole and G-CSF, patients with deep mycosis and suspected deep mycosis were divided into 3 groups. Group I: miconazole and G-CSF were administered simultaneously. Group II: miconazole was administered later during G-CSF administration. Group III: only miconazole was administered. Of a total of 117 cases 105 cases were analyzed including group I 37 cases, group II 39 cases and group III 29 cases, excluding 12 dropout and inadequate cases. Of the 105 cases, deep mycosis were 31 and suspected deep mycosis were 74, and underlying diseases were hematological malignancies such as leukemias. Efficacy judged mainly by the change of fever was 62.2% (23/37) in group I, 43.6% (17/39) in group II, and 41.4% (12/29) in group III, respectively. Efficacy was better in the patients whose neutrophil counts increased from less than 500/microliters to more than 500/microliters (group I 75.0%, group II 72.7%) than in the patients whose neutrophil counts were less than 500/microliters throughout the time of miconazole administration (group I 33.3%, group II 33.3%). Adverse effects were minimal in 3 groups (group I 15.4%, group II 17.4%, group III 15.6%). It is concluded that the combination with miconazole and G-CSF is effective in the treatment of deep fungal infections.

Adult↗
PubMed1995

Insulin modulation of bronchial epithelial cell fibronectin in vitro.

Fibronectin (Fn) is involved in the migration of epithelial cells in re-epithelialization of wounds. Epithelial cell-derived Fn is particularly potent as a chemotactic factor for bronchial epithelial cells (BECs) in vitro. Thus modulation of airway epithelial cell Fn may be a key aspect of airway repair. Insulin is both an important growth factor and known chemotactic factor for cultured BECs. We postulated that insulin may modulate Fn production of cultured BECs. We examined this hypothesis utilizing bovine BECs in culture with serum-free media with and without insulin. BECs grown in media without insulin released more Fn into culture supernatants and contained more Fn in cell layers than cells grown with insulin. Labeling of cells with [35S]methionine demonstrated an increase in new protein production and Fn mRNA expression was increased. Increased Fn in BEC cultures without insulin was associated with an increase in active transforming growth factor-beta (TGF-beta) release as measured by a standard bioassay. Increased BEC Fn in cultures without insulin was partially inhibited by exposure of cultures to TGF-beta antibody. Thus insulin appears to modulate BEC Fn production in vitro in part through a TGF-beta-dependent mechanism. Insulin may be involved in airway repair mechanisms through modulation of epithelial cell Fn production.

Animals↗
PubMed1995

Utilization behavior after right thalamic infarction.

We report a patient who showed exaggerated responses to external cues (utilization behavior), motor impersistence, and a right-hand-predominant instinctive grasp reaction after right thalamic infarction. High-resolution computed tomography with stereotaxic lesion localization revealed almost complete destruction of the ventroanterior nucleus and intralaminar nuclei of the right thalamus; the dorsomedial nucleus was only partially involved. Single photon emission computed tomography revealed hypoperfusion in the right thalamus and over the entire right cerebral cortex with some prominence in the frontal area. From these observations, we believe that the utilization behavior in our case was caused by the disturbance in maintaining cortical tone of the right hemisphere as well as by the dysfunction of the right frontal lobe, both secondary to the damage to the right ventroanterior nucleus and intralaminar nuclei.

Aged↗