Search PubMed⌕ Search

Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 973 records · Page 54Linked to original sources
PubMed1987

Complete nucleotide sequence of pTZ12, a chloramphenicol-resistance plasmid of Bacillus subtilis.

The complete nucleotide sequence of pTZ12, a chloramphenicol-resistance (CmR) plasmid (2517 bp) derived from Corynebacterium xerosis plasmid pTZ10, has been determined after propagation in Bacillus subtilis. The nucleotide sequence of pTZ12 suggests that a recombination event may have occurred naturally within the open reading frames for the Rep protein of pT181 (or a pT181-like plasmid) and pC221 (or a pC221-like plasmid).

Amino Acid Sequence↗
PubMed1987

The effect of ACTH on plastic synapses in the developing mouse brain.

We studied the effect of ACTH on plastic synapses in the hippocampal gyrus of the developing mouse brain. Examination of ethanolic phosphotungustic acid stained synaptic junctions revealed no obvious differences between the ACTH-treated brains and controls qualitatively and quantitatively. Therefore, ACTH may not adversely affect the plastic synapses in the developing mouse brain.

Adrenocorticotropic Hormone↗
PubMed1987

New tetracycline resistance determinant on R plasmids from Vibrio anguillarum.

Two classes of tetracycline resistance determinants on R plasmids were detected in Vibrio anguillarum strains isolated from ayu (sweat fish; Plecoglossus altivelis) farms in Japan. Tetracycline resistance genes categorized as class B were prevalent from 1973 to 1977; however, a new tetracycline resistance gene, which was not classified into tetracycline resistance determinant class A, B, C, or D, has been prevalent since 1981.

Chromosome Mapping↗
PubMed1987

A freeze-fracture study of the plasma membrane of the Ito cell in the normal rat liver.

The plasma membrane of the Ito cell in the normal rat liver was studied by freeze-fracture electron microscopy. Ito cells appeared to adhere to endothelial cells or to be embedded in the microvilli of hepatocytes. Ramified processes with a few microvilli of the cell extended along the endothelial cells. Caveolae were constantly seen on the plasma membrane, but their numbers varied among cells. Two different patterns of intramembranous particles were found on the plasma membrane of the Ito cells: most cells showed an even distribution of the particles, but the others, aggregates of them. Particle-free domains were seen on the plasma membrane in some Ito cells. Piles of concave or convex sheets were sometimes seen in the freeze-fractured lipid droplets.

Animals↗
PubMed1987

A local anesthetic, tetracaine, similarly inhibits Ag+ and K+ contractures in frog skeletal muscle.

To evaluate usefulness of Ag+ contracture as a tool for elucidating the mechanism underlying the excitation-contraction coupling, the effects of tetracaine on Ag+ contracture were compared with those on K+ and caffeine contractures in frog skeletal muscle. Tetracaine less than 100 microM shortened the duration of 120 mM K+ contracture, without affecting tension amplitude. At higher concentrations of tetracaine, K+ contracture was inhibited dose-dependently and the duration shortened. Treatment of the fibers with 20-500 microM tetracaine for 3 min did not block the contracture induced by 25 mM caffeine. Effects of tetracaine on Ag+ contracture were similar to those on K+ contracture. In the presence of 200 microM tetracaine, 41% inhibition was observed in 120 mM K+ contracture, while 43% in 100 microM Ag+ contracture. Also, 200 microM tetracaine completely inhibited the contractures induced by 40 mM K+ or 5 microM Ag+. These findings suggest that the Ag+ may induce contractures via its action on the T/SR junction, not a direct action on the SR. Therefore, understanding the mechanism involved in the development of Ag+ contracture would be helpful to elucidate the mechanism of excitation-contraction coupling.

Action Potentials↗
PubMed1987

Clinical benefits of intravenously administered famotidine in the treatment of upper gastrointestinal hemorrhage caused by peptic ulcer and stress ulcer disease.

Bleeding may stop spontaneously in mild or moderate cases of GI bleeding. Therefore, to prove that H2-receptor antagonists effectively stop GI bleeding, evaluation of the results of treatment in patients who are classified as severe cases by the Nagao taxonomy is needed. Data from the literature show that mortality is higher in patients with specific endoscopic findings, such as active bleeding, visible vessels, clot, or stain, than it is in patients without these findings. The criteria for establishing whether H2-receptor antagonists effectively control GI bleeding in severe cases include a reduction in mortality, in the rate of recurrent bleeding, or in the rate of emergency surgery. Data gathered from a current multicenter trial assessing the efficacy of 20 mg famotidine administered intravenously twice daily show that the rate of emergency surgery in patients with bleeding ulcer is 8.6%, which is substantially less than the 54.2% rate found in a retrospective review of patients treated before the introduction of H2-receptor antagonists. In addition, there were no deaths among famotidine-treated patients. Similarly, among patients with bleeding caused by stress ulcer, the percentage who were treated with famotidine and required emergency surgery was much less than that in the historical control group (15.8% versus 40.0%). Famotidine was effective in greater than or equal to 88% of patients with peptic ulcers and in 78.9% of patients with stress ulcers. Recurrent bleeding occurred more often in patients with exposed blood vessels. Intravenously administered famotidine is, therefore, effective for the control of GI bleeding caused by severe peptic ulcer and stress ulcer disease.

Endoscopy↗
PubMed1987

Low natural killer syndrome: clinical and immunologic features.

Twenty-three patients with low natural killer syndrome (LNKS), 7 males and 16 females, are reported here. These LNKS patients had an age range from 14 to 77 years, with a median of 36.5 years. LNKS is a newly proposed category of immune disorders, being characteristically diagnosed by lowered NK cell activity against K562 target cells as a definite laboratory abnormality, in association with general clinical symptoms of remittent fever and uncomfortable fatigue, persisting without explanation for more than 6 months. Other immune parameters, such as the DNA synthesis of peripheral blood mononuclear cells (PBMCs) in either the presence or absence of mitogens, the T4+/T8+ ratio and the number of Leu-11+ PBMCs, were usually within the normal range. Also, routine laboratory tests did not detect any abnormal findings. The LNKS patients responded well to the administration of an immunopotentiator called 'lentinan', a glucan extracted from the Japanese mushroom Lentinus edodes, despite no responses to conventional fever treatments such as the administration of antipyretics or antibiotics. All LNKS patients observed were universally free of antibodies in their sera to human T-lymphotropic retroviruses I and III, and lymphadenopathy was infrequent, indicating that the LNKS is a syndrome independent of acquired immunodeficiency syndrome (AIDS) or AIDS-related complex. Antibodies to other known viruses tested such as Epstein-Barr or measles virus, or cytomegalovirus were also negative or not significantly elevated in the sera before the initiation of lentinan administration. If a virus is the cause of LNKS, it may be a new, unknown virus or an unknown substrain of known viruses. None of the LNKS patients has died of this syndrome.

Adolescent↗
PubMed1987

[High-risk group--colorectal cancer].

The environmental factor, pathogenic factor, host factor and others can be assumed as high-risk factors of colon carcinoma. Histopathologically, in most cases, colon carcinoma is recognized as an adenoma-carcinoma sequence that originates based on the adenoma. In this study, in addition to the adenoma and adenomatosis (familial polyposis, Gardner syndrome, Turcot syndrome), the hamartoma (Peutz-Jeghers syndrome, juvenile polyp), inflammatory bowel diseases (ulcerative colitis, Crohn's disease, fistel ani and others) and the origin of the carcinoma were examined. The oncogenesis based on the tubular adenoma, tubulovillous adenoma, villous adenoma and genetic adenomatosis of the large intestine could be found in many cases, thereby requiring a wide range of examinations and treatments. Concerning the oncogenesis of several kinds of inflammatory bowel diseases, much attention should be paid to diseases such as ulcerative colitis, Crohn's diseases, and fistel ani extending over a period of 10 years. In addition, it is necessary to study the connection and promotion among factors of the environmental, pathogenic and host factors.

Adenomatous Polyposis Coli↗
PubMed1987

Induction of tumors in the liver, urinary bladder, esophagus and forestomach by short-term treatment with different doses of N,N'-dibutylnitrosamine in rats.

The multipotential carcinogen N,N'-dibutylnitrosamine (DBN) was given to F344 male rats for 2 weeks at three dose levels to study the concentration dependence of its organ specificity. Groups of 20 rats were given water containing 0.25, 0.125 or 0.063% DBN for 2 weeks and then tap water only to drink until they were killed 52 weeks after the start of the experiment. DBN induced preneoplastic lesions in the liver, esophagus, forestomach and urinary bladder. Carcinoma was found only in the liver. Induction of preneoplastic focal hepatocyte lesions positive for the P-form of glutathione S-transferase (GST-P) was quantitatively dependent on the dose of DBN. In the urinary bladder, the incidences of papillary or nodular hyperplasia (PNH) and papilloma of transitional cells tended to increase at higher doses. The incidence and number per unit length of basal cell-type hyperplasias of the esophageal epithelium were significantly higher in all DBN groups than in the control group, through the increase did not show a clear dose-dependency. The incidence of epithelial basal cell hyperplasia of the forestomach was significantly increased at all doses and the increase was apparently dose-related. These results indicate that even in a short-term experiment, DBN exerted multipotential carcinogenic effects. Thus, this system could be used for assay of the modifying effects of compounds administered subsequently on carcinogenesis in different organs.

Animals↗
PubMed1987

Enhancing effects of N-ethyl-N'-nitro-N-nitrosoguanidine and sodium taurocholate on development of pepsinogen 1 decreased pyloric glands in rats initiated with N-methyl-N'-nitro-N-nitrosoguanidine.

Sequential quantitative analyses were made of pepsinogen 1 (Pg 1) decreased pyloric glands after treating male WKY rats first with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and then with N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) as a second gastric carcinogen or sodium taurocholate (Na-TC) as a gastric promoter. Animals received a single dose of MNNG (160 mg/kg body weight) by gastric intubation followed two weeks later by either ENNG in drinking water (100 micrograms/ml) (group 1), basal diet containing 0.25% Na-TC (group 2), or basal diet and tap water (group 3), from weeks 3 to 24. Animals were sacrificed at weeks 8, 12, 16, 20 and 24. Sections of the pyloric mucosa were investigated for Pg 1 immunostaining. In comparison with group 3, induction of Pg 1 decreased pyloric glands was significantly enhanced by ENNG from week 8 and by Na-TC from week 16. The former exerted a significantly stronger effect at each time point. The results suggest that Pg 1 decreased pyloric glands represent a good marker for early detection of gastric carcinogens and promoters in in vivo test systems.

Animals↗
PubMed1987

Patterns of epithelial proliferation revealed by continuous administration of bromodeoxyuridine during urinary bladder carcinogenesis in rats.

The patterns of epithelial proliferation in the urinary bladder during carcinogenesis were examined sequentially in rats given drinking water supplemented with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 12 weeks and then water without BBN for 18 weeks. Animals received 120 micrograms of bromodeoxyuridine (BrdU) per hour continuously via an osmotic minipump for 4 days before sacrifice and labeled cells were detected immunohistochemically using monoclonal antibody against BrdU. Two types of BBN-induced epithelial lesions were distinguishable: reversible changes characterized by proliferation of basal cells only, and irreversible changes with high and irregularly distributed incorporation of label throughout the epithelium. Simple hyperplasia, and papillary or nodular hyperplasia consisted of areas of reversible and/or irreversible changes, whereas papilloma and cancer consisted of areas of irreversible changes.

Animals↗
PubMed1987

[The diagnostic method of localization of cerebrospinal fluid rhinorrhea by digital video subtraction system].

Demonstration of the exact site of the dural fistula in cerebrospinal fluid rhinorrhea is difficult. Previous reports present the methods of metrizamide cisternography combined with both hypocycloid tomography and computed tomography. But in these methods, direct, dynamic, actual and real-time visualization of the fistula with minimal dose of metrizamide is rather difficult. By using digital video subtraction system (Philips DVI-2CV), we could visualize the direct, dynamic and actual site of fistula with small amount of metrizamide instilled into the suboccipital subarachnoid space with the patient prone position. We report a successful case of traumatic cerebrospinal fluid rhinorrhea drained through the bony defect at the planum sphenoid into the posterior ethmoid sinus. This is the first report to deal with the usefulness of digital video subtraction system for exact localization of cerebrospinal fluid rhinorrhea. We emphasize the usefulness of metrizamide cisternography by the digital video subtraction system combined with the metrizamide computed tomographic cisternography for the precise localization of dural fistula.

Adult↗
PubMed1987

[Bacteriological and clinical studies on flomoxef in the pediatric field].

Bacteriological and clinical studies on flomoxef (FMOX, 6315-S) were performed and the results obtained are summarized below. 1. The MIC values of FMOX against 307 clinically isolated strains of Staphylococcus aureus were 0.024 to 100 micrograms/ml with a peak MIC of 0.39 microgram/ml, and the MIC90 value was 1.56 micrograms/ml. The MIC90 against methicillin resistant S. aureus (MRSA) was 25 micrograms/ml. 2. FMOX was administered to 15 children with pediatric bacterial infections, and the effectiveness was rated excellent or good in all cases. 3. In bacteriological evaluation, 7 of 11 strains identified prior to the treatment were eliminated (63.6%). 4. As side effects, diarrhea or soft stool was found in 3 cases and eruption in 1 case. As abnormal laboratory values, eosinophilia and thrombocytosis were found in 1 case each. 5. On the intestinal bacterial flora, FMOX had a marked influence just as did other Group 4 and 5 cephems antibiotics. 6. FMOX interfered little with the coagulation system or platelet aggregation.

Age Factors↗