Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 973 records · Page 54Linked to original sources

PubMed1989

Bottle-feeding can prevent transmission of HTLV-I from mothers to their babies.

Breast-feeding is a major factor in the vertical transmission of human T-lymphotropic virus type I (HTLV-I). We studied whether such transmission may be prevented by bottle-feeding. HTLV-I infection was detected by both HTLV-I antigen and antibody tests. Thirty bottle-fed babies were examined 24 months after birth; only one was found to be HTLV-I antigen-positive. This infection rate was lower than that for breast-fed babies in whom HTLV-I antigen was detected in 24 of the 31 24-month-old babies born to HTLV-I positive mothers in a previous study. These results suggest that most vertical transmission of HTLV-I is attributable to breast-feeding and can be prevented by bottle-feeding.

Bottle Feeding↗

PubMed1989

Disappearance and appearance of isoenzymes of creatine kinase, lactate dehydrogenase and aspartate aminotransferase in the myocardium undergoing infarction.

Recent investigations have shown that cardiac isoenzymes change with mechanical overload and possibly with myocardial ischaemia. This complicates the interpretation of serum enzyme changes in acute myocardial infarction. We have therefore investigated the rate of release of isoenzymes from necrosing myocardium and the effect of ischaemia per se. Discrete myocardial infarction was produced in 35 male Wistar rats by ligation of left coronary artery. Six (n = 7), 12 (n = 6), 24 (n = 9), 72 (n = 7) h and 3 weeks (n = 6) after surgery, total and isoenzyme activities of creatine kinase (CK), lactate dehydrogenase (LD) and aspartate aminotransferase (AST) were measured in the infarcted myocardium. Untreated rats (n = 12) were used as the control (time 0). Sham operation was performed in 36 rats. During the early period (0 to 12 or 24 h) of infarction, each (iso)enzyme disappeared monoexponentially from the myocardium (mean r = 0.88) with different disappearance rates. Cytosolic isoenzyme fractions decreased more rapidly than mitochondrial fractions. CK MB and the LD-H subunit decreased faster than CK MM and the LD-M subunit. Such differences in the disappearance rate may be related to subcellular localisation of each isoenzyme. In the late period (72 h and 3 weeks), CK BB and the LD-M subunit showed significant reaccumulation in the infarcted myocardium. Although inflammatory cells can be responsible for the reaccumulation of LD-M subunit, the origin of CK BB is unknown.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Properties of L-lysine epsilon-dehydrogenase from Agrobacterium tumefaciens.

Lysine epsilon-dehydrogenase, which has been purified to homogeneity from the extract of Agrobacterium tumefaciens ICR 1600, had a molecular weight of approximately 78,000 and consisted of two subunits identical in molecular weight (about 39,000). The enzyme showed a high substrate specificity. In addition to L-lysine, S-(beta-aminoethyl)-L-cysteine was deaminated by the enzyme, but to a far lesser extent. NAD+ and some NAD+ analogs (deamino-NAD+ and 3-acetylpyridine-NAD+) served as a cofactor. The pH optimum was at about 9.7 for the deamination of L-lysine. Although the NAD+ saturation curve was hyperbolic, a sigmoid saturation curve for L-lysine was obtained with the diluted enzyme solution, in which the dimeric enzyme was predominant. The reversible association of the enzyme to the tetramer was induced either by increasing the enzyme concentration or by addition of L-lysine. The preincubation of the enzyme with 5 mM L-lysine resulted in a 2-fold increase in the activity and gave a hyperbolic saturation curve for L-lysine. Upon modification of SH groups of the enzyme with DTNB, neither the interconversion between the dimer and the tetramer nor the activation by L-lysine occurred. These results indicated that the dimeric enzyme was activated by L-lysine and the activation resulted from the association of two dimeric enzymes to form a tetramer.

Amino Acids↗

PubMed1989

Activation of L-lysine epsilon-dehydrogenase from Agrobacterium tumefaciens by several amino acids and monocarboxylates.

The activation of lysine epsilon-dehydrogenase [EC 1.4.1.] by L-lysine was dependent on lysine concentration and was accompanied by association of the dimeric enzymes to a tetramer. The lysine concentration required for the half-maximal activation was 0.28 mM, which was lower than the Km value for L-lysine. In addition to L-lysine, several compounds, which were neither substrates nor inhibitors, activated the enzyme. The compounds which activated the enzyme have common structural characteristics: they have both a carboxyl group and a hydrophobic side chain. These activators also induced the association of the enzyme. The activation of the enzyme occurred well over the pH range 5.0 to 7.5, and the maximal activation was obtained by preincubation for 5 min at 30 degrees C and pH 7.4, when 5 mM L-lysine or 6-aminocaproate was used as an activator. NADH binding experiments indicated that about 2 mol of NADH bind to 1 mol of the tetrameric enzyme: the dimeric enzyme has one catalytic site. Binding experiments with n-[1-14C]heptanoate and L-[U-14C]lysine showed that approximately 2 mol of ligands bind to 1 mol of the dimeric enzyme and L-lysine could not bind to the catalytic site of the enzyme in the absence of NAD+. These results indicate the presence of one catalytic site and two activator binding binding sites in the dimeric enzyme.

Amino Acid Oxidoreductases↗

PubMed1989

Myofibromatosis in adults (adult counterpart of infantile myofibromatosis).

Five solitary, benign, soft-tissue tumors histologically resembling infantile myofibromatosis but which occurred in adults were found among more than 5,000 benign soft-tissue tumors from a tumor registry. The tumors clinically presented as superficial, painless, and slowly enlarging nodules, usually of more than 10 years' duration, that occurred in the upper (two cases) and lower (two cases) extremities or the buccal mucosa (one case). They developed in the dermis and subcutis as well-circumscribed nodules with an average diameter of 1.2 cm. They were composed of discrete and confluent fibrous tissue with a mixture of bundles of smooth muscle-like cells and a hemangiopericytoma-like area of immature mesenchymal cells. Immunostaining for actin and intermediate filaments revealed the myofibroblastic nature of the tumor cells. The tumors were surgically excised, and there has been no recurrence. Clinicians and pathologists should note that the lesion of infantile myofibromatosis can and does occur in adults.

Actins↗

PubMed1989

Effect of light on the chloroplast division cycle and DNA synthesis in cultured leaf discs of spinach.

The effects of light on both the division cycle of chloroplasts and the synthesis of chloroplast DNA were investigated in cultured discs taken from the distal end of 2-centimeter spinach (Spinacia oleracea) leaves. Comparisons were made of discs cultured for a maximum of 4 days in a shaking liquid medium under continuous white light, darkness, and of discs cultured for 1 day in light following 3 days in darkness. In continuous white light the shortest generation time of chloroplasts observed in this study was 19.4 hours and the duration of spherical, ovoid, and dumbbell-shaped stages in the division cycle were 13.4, 2.8, and 3.1 hours, respectively. In darkness the generation times of chloroplasts extended to 51.5 hours. Under these conditions the duration of spherical, ovoid, and dumbbell-shaped stages were 22.8, 8.4, and 20.2 hours, respectively, suggesting that in darkness the separation of dumbbell-shaped chloroplasts may be the rate limiting step. When discs cultured in the dark were transferred to light, most dumbbell-shaped chloroplasts separated into daughter chloroplasts in less than an hour. Measurements of chloroplast DNA established that the cellular level of chloroplast DNA increased 10-fold over the 4 days of culture in continuous white light. Comparisons of the plastids of dark and light grown discs showed that the synthesis of chloroplast DNA was enhanced by light. Observations of DAPI stained dividing chloroplasts indicate that DNA partitioning can take place during the final stage of chloroplast division and that it does not precede plastid division.

Journal Article↗

PubMed1989

Effect of freeze-thawing breast milk on vertical HTLV-I transmission from seropositive mothers to children.

Breast feeding is known to be a major cause of vertical transmission of HTLV-I from mothers to her children. The infectiousness of HTLV-I in breast milk was reported to be lost during freezing and thawing processes. We therefore administered frozen-and-thawed breast milk of HTLV-I carriers to their babies. Among the 13 babies given the frozen-and-thawed breast milk (now 12 months of age), no infection has been found yet. This result suggests that freezing and thawing of breast milk is a promising method for the prevention of vertical HTLV-I infection to breast-fed babies.

Breast Feeding↗

PubMed1989

Clear cell chondrosarcoma. A case report with topographic analysis.

A case of clear cell chondrosarcoma located in the right proximal end of the femur is presented. Radiologically, the tumor appeared as a large osteolytic lesion with mottled calcification resembling chondroblastoma. Histologically, the greater portion was made up of tumor cells with abundant clear cytoplasm and usually distinct boundaries, associated with areas of conventional chondrosarcoma. The proportion of the clear cell areas was about 60%, and they were mainly distributed along the tumor periphery. Moreover, myxoid chondrosarcoma-like areas, a feature not previously mentioned in clear cell chondrosarcoma, were observed, occupying about 10% of the tumor area.

Adult↗

PubMed1989

Comparative study of neuroectodermal tumor and Ewing's sarcoma of the bone. Histopathologic, immunohistochemical and ultrastructural features.

We carried out a histologic, immunohistochemical and ultrastructural study of 19 tumors, previously classified as Ewing's sarcoma of the bone (ESB). The tumors were categorized histologically into four groups according to the presence or absence and the distribution of Homer-Wright rosettes, together with the immunohistochemical and ultrastructural features: 1) neuroectodermal tumor of bone (NTB) with diffusely dispersed rosettes (4 cases), 2) conventional ESB totally lacking the rosettes (9 cases), 3) intermediate-type tumor with characteristics of both NTB and ESB (4 cases), and 4) spindle cell-type tumor with focal rosettes (2 cases). Ultrastructurally, NTB contained neurotubules and neurosecretory granules, whereas ESB consisted of only undifferentiated cells. Immunoreactivity with antineural antibodies, such as Leu-7, and those against synaptophysin, NSE, neurofilament, and chromogranin, was detected in the majority of NTB, in intermediate- and spindle cell-type tumors and in two of the nine cases of ESB. In view of these findings, we propose that use of the term "neuroectodermal tumor of the bone" should be restricted to tumors with an extensive distribution of rosettes, and that those without unequivocal rosettes should be classified as ESB, although ESB may be the most undifferentiated form of NTB and some overlap may occur between the two tumor types.

Adolescent↗

PubMed1989

Two cases of cystic fibrosis in Japanese children: studies on the essential fatty acid and prostaglandin metabolism.

We describe the fatty acid (FA) and prostaglandin (PG) metabolism in two Japanese cases of cystic fibrosis (CF) with or without pancreatic insufficiency (PI). The diagnosis of CF was based on the elevated sweat chloride concentration by pilocarpine iontophoresis. A 1-month-old boy (case 1) showed poor weight gain, steatorrhea and scaly dermatitis, but no respiratory symptoms were noted. He had decreased levels of serum linoleate and arachidonate, and increased palmitoleate and oleate levels, indicating essential fatty acid (EFA) deficiency. Supplementation of fat-emulsion improved his skin lesions and the altered FA pattern within a few months, associated with the definite reduction of the urinary PG F2 alpha levels. Until two years of age, he has been free from respiratory symptoms. A 12-year-old girl (case 2) had had recurrent respiratory tract infections due to Pseudomonas aeruginosa and Staphylococcus aureus for several years, and her pancreatic functions were preserved. The FA patterns of her serum lipid were almost within the normal range. These results indicate that 1) the altered FA composition appeared to be a secondary consequence of PI commonly complicating CF and 2) the correction of the altered FA and PG metabolism might have a beneficial effect on the respiratory function of CF patients with EFA deficiency.

Child↗

PubMed1989

Differential antagonism of the negative inotropic effect of gentamicin by calcium ions, Bay K 8644 and isoprenaline in canine ventricular muscle: comparison with cobalt ions.

1. Gentamicin (10(-4)-10(-2) M) and Co2+ (10(-4)-10(-2) M) produced a decrease in developed tension of canine isolated ventricular muscles leading to near abolition at 10(-2) M. Their negative inotropic effects developed rapidly and wore off shortly after wash-out. 2. The concentration-negative inotropic effect curves for gentamicin were shifted to the right in a parallel manner by increasing external Ca2+, or by the presence of Bay K 8644 (10(-7)-10(-5) M) or isoprenaline (10(-7)-10(-5) M). IC50 values for gentamicin increased about 3-fold with about a 6 fold increase in external Ca2+. The Schild plot yielded a pA2 of 2.29 for Ca2+ and its slope was -1.17 (r = -0.79). 3. The concentration-negative inotropic effect curves for Co2+ were shifted to the right in a parallel manner by increasing external Ca2+, or by the presence of isoprenaline (10(-7)-10(-5) M). IC50 values for Co2+ increased about 5 fold with about a 6 fold increase in external Ca2+. The Schild plot gave a pA2 value of 2.60 for Ca2+ and its slope was -1.11 (r = -0.86). 4. The concentration-positive inotropic effect curves for Ca2+, which were computer-fitted to a logistic equation, gave 2.88 x 10(-3) M for EC50. This value was very close to the KCa calculated from pA2 values for Ca2+ based on antagonism between gentamicin or Co2+ and Ca2+ (5.13 x 10(-3) and 2.51 x 10(-3) M). 5. It is concluded that like Co2+, gentamicin molecules compete with Ca2+ for the same binding sites presumably located at the outer orifice of Ca-channels in the cardiac sarcolemma.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1989

Interaction of potassium channel openers and blockers in canine atrial muscle.

1. The possibility that the interaction between potassium channel openers, e.g. cromakalim, pinacidil and nicorandil, and some potassium channel blockers involves a common site was investigated in canine atrial muscle. 2. Cromakalim, pinacidil and nicorandil produced a negative inotropic effect, their pD2 (-log EC50) values being 6.11 +/- 0.07, 5.37 +/- 0.09 and 4.55 +/- 0.07, respectively. 3. The potassium channel blockers, tetraethylammonium (TEA), tetrabutylammonium (TBA), 3,4-diaminopyridine (DAP), CsCl and BaCl2 all produced a positive inotropic effect. 4. The concentration-effect curves for the negative inotropic actions of pinacidil were shifted in a parallel way to the right by low concentrations of TEA, TBA or BaCl2. Maximum responses to pinacidil were depressed by higher concentrations of the blockers. An analysis of the non-competitive antagonism by TEA yielded pKA (-log KA) values of 4.00-4.05 for pinacidil. 5. The concentration-effect curves for cromakalim and nicorandil were shifted by TEA similarly to those for pinacidil, and a similar analysis yielded pKA values of 4.47-4.68 for cromakalim and 3.47-3.74 for nicorandil. 6. The KA values of cromakalim, pinacidil and nicorandil were about 10-30 times greater than their EC50 values, indicating that there are non-linear stimulus-effect relationships between the binding of the three potassium channel openers to their binding sites at potassium channels and their negative inotropic effects. 7. The dissociation constants for TEA could also be estimated from pA2 and pKB values for antagonizing competitively and non-competitively the negative inotropic effects of the three potassium channel openers; they were 3.47-3.89, and did not differ between the potassium channel openers. 8. The concentration-effect curves for the three potassium channel openers were not affected by DAP or CsCl. 9. These results suggest the following: (i) quaternary ammonium compounds like TEA and TBA antagonize the negative inotropic effect of cromakalim, pinacidil and nicorandil by binding to potassium channels, thus preventing binding of the channel openers to the same sites or closely related sites in canine right atrial muscles.

Animals↗

PubMed1989

Electrophysiological abnormalities and enhanced reperfusion arrhythmias in the isolated hearts of hyperthyroid rats.

1. The influence of hyperthyroidism on electrophysiological characteristics and on reperfusion arrhythmias was examined in rat hearts. 2. Electrophysiological studies were performed with glass microelectrodes, and the experiments on reperfusion arrhythmias were done in isolated perfused hearts. 3. Ventricular muscle from hyperthyroid rats was more prone than that from euthyroid rats to develop triggered activity under conditions believed to cause myoplasmic Ca2+ overload. 4. The severity of reperfusion arrhythmias was significantly enhanced in hyperthyroid preparations as compared with euthyroid ones. 5. The enhanced reperfusion arrhythmias in hyperthyroid rats were significantly reduced by propranolol (3 x 10(-7) M), lignocaine (1 x 10(-5) M) and verapamil (3 x 10(-8) M), but not by nadolol (3 x 10(-7) M) or prazosin (3 x 10(-7) M). 6. These results suggest that increased heart rate due to hyperthyroidism and responses mediated via either alpha- or beta-adrenoceptors were not dominant causes of enhanced reperfusion arrhythmias in hyperthyroid hearts. 7. The increased tendency to develop triggered activity which was observed in the electrophysiological study, may be one possible explanation of enhanced reperfusion arrhythmias in hyperthyroid hearts.

Action Potentials↗

PubMed1989

[Drug-resistance and its transferability of Shigella strains isolated in 1986 in Japan].

Two hundred and fifty Shigella strains isolated in Japan were examined for their drug-resistances and their conjugal transferability. Drugs used and the isolation frequency of resistant strains were: sulfanilamide (SA) 96%, streptomycin (SM) 85%, tetracycline (TC) 82%, fosfomycin (FOM) 76%, chloramphenicol (CP) 51%, trimethoprim (TMP) 46%, ampicillin (ABPC) 45%, nalidixic acid (NA) 6%, kanamycin (KM) 5%, cephaloridine (CER) 4%, gentamicin (GM) 0%, amikacin (AMK) 0%, colistin (CL) 0%, norfloxacin (NFLX) 0%. All of the KM-resistances and none of the FOM-resistances were transferable. Each 20 to 30% of CP, TC, SM, SA or ABPC-resistant isolates transferred each drug-resistance. Two thirds of the isolates were brought to Japan by travellers mostly from South-East Asia. The isolation frequency of resistant strains was not different between domestic and foreign strains except that NA-resistance was not found in foreign strains. The frequency of isolates carrying transferable R plasmids were higher in domestic strains than foreign strains. Most of the isolated had multiple drug-resistance. Major resistance types were: (CP, TC, SM, SA, ABPC) 22%; (TC, SM, SA, TMP) 20%; (CP, TC, SM, SA, ABPC, TMP) 16%; (TC, SM, SA) 8%. Strains showing different resistance types were different among each other in their serum type, conjugal transferability, and derived country. Stepwise evolution of multiple resistance in one country was not demonstrated. The resistance types of Shigella isolates in Japan have been influenced by yearly change of imported strains.

Anti-Bacterial Agents↗

PubMed1989

Characterization of toxigenic vibrios isolated from the freshwater environment of Hiroshima, Japan.

The occurrence and characterization of toxigenic vibrios in surface water and sediment samples of the fresh water environment of the Ohta River were studied. The membrane filter, pad preenrichment technique, followed by the placement of membranes onto thiosulfate citrate-bile salt-sucrose agar, was used for the enumeration of total vibrios. Qualitative examination of pathogenic vibrios was also attempted. In addition, a survey was conducted to determine the incidence of Clostridium botulinum in sediment samples of the Ohta River and the Hiroshima coast. In the identification of 361 strains, 12 species of Vibrio and two species of Listonella were observed. Non-01 Vibrio cholerae was prevalent among the members of the genus Vibrio. Vibrio parahaemolyticus (serotype 04:K34), isolated in fresh water, is significant and suggests that some still unknown conditions promote the survival of these organisms in fresh water. An estimated 132 strains were hemolytic by a simple agar method, and further characterization revealed that 82% of the hemolytic vibrios (107 strains) produced various toxins. About 71% (93 strains) elaborated cytotoxin, 55% (72 strains) produced hemolysin, and 44% (58 strains) responded for both cytotoxin and hemolysin in the crude toxin extracts. All the non-01 V. cholerae showed cytotoxic activity, and the virulent strains of Vibrio fluvialis and Vibrio spp. showed cytotonic responses in RK-13 cells. Of 36 sediment samples tested, 10 harbored C. botulinum spores (28%) and were isolated invariably in all the regions of the Hiroshima coast and in the Ohta River, except the upper region of the Ohta River.

Bacterial Toxins↗

PubMed1989

Occurrence and distribution of Vibrio spp., Listonella spp., and Clostridium botulinum in the Seto Inland Sea of Japan.

The distribution of Vibrio species in samples of surface water, bottom water (water 2 m above the sediment), and sediment from the Seto Inland Sea was studied. A simple technique using a membrane filter and short preenrichment in alkaline peptone water was developed to resuscitate the injured cells, followed by plating them onto TCBS agar. In addition, a survey was conducted to determine the incidence of Clostridium botulinum in sediment samples. Large populations of heterotrophs were found in surface water, whereas large numbers of total vibrios were found in bottom water. In samples from various water sampling regions, high counts of all bacterial populations were found in the inner regions having little exchange of seawater when compared with those of the open region of the inland sea. In the identification of 463 isolates, 23 Vibrio spp. and 2 Listonella spp. were observed. V. harveyi was prevalent among the members of the Vibrio genus. Vibrio species were categorized into six groups; an estimated 20% of these species were in the so-called "pathogenic to humans" group. In addition, a significant proportion of this group was hemolytic and found in the Bisan Seto region. V. vulnificus, V. fluvialis, and V. cholerae non-O1 predominated in the constricted area of the inland sea, which is eutrophic as a result of riverine influence. It was concluded that salinity indirectly governs the distribution of total vibrios and analysis of variance revealed that all bacterial populations were distributed homogeneously and the variance values were found to be significant in some water sampling regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1989

Ecology of Vibrio cholerae non-O1 and Salmonella spp. and role of zooplankton in their seasonal distribution in Fukuyama coastal waters, Japan.

Seasonal variation of human pathogens such as Vibrio Cholerae non-01 and Salmonella spp. in Fukuyama coastal waters and the role of zooplankton in their distribution were studies for a period of 1 year. Comparison of two established methods, viz., the elevated temperature method and the two-step enrichment method of enumerating V. cholerae, showed that the former is superior in the recoveries of V. cholerae non-01. Isolation of this pathogen on a wider range of salinities (0.4 to 32.5%) revealed that these organisms are apparently an autochthonous component of the aquatic environment. Temperature appears to be the most crucial element in governing the distribution of V. cholerae non-01. Among the 69 isolates serotyped, 22 different serovars were identified, while one isolate failed to react with any of the known Louisiana State University antisera tested. Zooplankton samples did not harbor more V. Cholerae non-01 than the water column did. Better isolation of an allochthonous pathogen, viz., Salmonella spp., was noticed from the water samples when swabs were employed. Of the 251 isolates serotyped, 18 serotypes with three variants of Salmonella spp. were identified. A high amount of nutrients in the water column increased the survival rate of these pathogens in saline waters as evidenced by a higher incidence of various serotypes in polluted Fukuyama port than in clean marine waters. Salmonella spp. association between V. cholerae non-01 of Salmonella spp. with zooplankton could be noticed as influencing their seasonal distribution.

Animals↗

PubMed1989

Relation between soluble interleukin 2 receptor and clinical findings in patients with systemic lupus erythematosus.

The concentration of soluble interleukin 2 receptor (IL-2R) was determined in the serum of 54 patients with systemic lupus erythematosus (SLE) by an enzyme linked immunosorbent assay (ELISA) using two monoclonal antibodies with the IL-2R. Concentrations of soluble IL-2R in the serum of the patients with SLE (study group) were significantly higher than in 20 normal subjects (control group). The relation between concentrations of soluble IL-2R and clinical findings was investigated. The concentration of soluble IL-2R showed no particular relation with the clinical manifestations and did not correlate with the level of anti-DNA antibody or CH50. Significant correlation between the concentration of soluble IL-2R and disease activity did exist, however. Furthermore, the concentration of soluble IL-2R in some cases changed simultaneously with the disease activity. Thus the concentration of soluble IL-2R may serve as a new clinical indicator of disease activity in patients with SLE.

Adult↗