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T Nakao

Publications and source records attributed to T Nakao.

At least 19 recordsLinked to original sources
PubMed1992

Structural characterization of a novel cholinergic neuron-specific ganglioside in bovine brain.

A new ganglioside antigen, termed Chol-1 alpha-b, recognized by cholinergic neuron-specific antibody, Chol-1 alpha, was isolated from bovine brain ganglioside mixture using Q-Sepharose. The yield was approximately 1.3 mg from 5 g of the total ganglioside. The chemical structure was characterized as a novel ganglioside by means of gas-liquid chromatography, a permethylation study, mild acid hydrolysis, thin layer chromatography-enzyme immunostaining, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The ganglioside has the following unique structure. [formula: see text] When examined by thin layer chromatography immunostaining and enzyme-linked immunosorbant assays, this ganglioside has the most intense immunoreactivity with Chol-1 alpha antibody among bovine brain gangliosides. As combined with our previous results (Hirabayashi, Y., Hyogo, A., Nakao, T., Tsuchiya, K., Suzuki, Y., Matsumoto, M., Kon, K., and Ando, S. (1990) J. Biol. Chem. 265, 8144-8151; Ando, S., Hirabayashi, Y., Kon, K., Inagaki, F., Tate, S., and Whittaker, X. (1992) J. Biochem. (Tokyo), 111, 287-290), the present study indicates the occurrence of a new series of gangliosides containing N-acetylneuraminic acid residue attaching to N-acetylgalactosamine as cholinergic specific antigens.

Animals↗
PubMed1992

Structural determination of gangliosides that bind to influenza A, B, and C viruses by an improved binding assay: strain-specific receptor epitopes in sialo-sugar chains.

An improved binding assay for detection of ganglioside receptors for influenza A, B, and C viruses was developed. In this system, the virions bound to gangliosides that were developed on a silica gel thin-layer plate were detected by mouse monoclonal antibody against viral hemagglutinin and peroxidase-conjugated anti-mouse immunoglobin. No hydrolysis of the gangliosides by viral receptor-destroying enzyme was detected in the present condition. The reactivity of the viruses to gangliosides depended on the amount of developed gangliosides (10 pmols-10 nmols), the molecular species of sialic acid, and their sugar sequences. Human influenza A (PR/8/34), B (Lee/40), and C (Ann Arbor/1/50) viruses bound different receptor epitopes of sialo-sugar chains of gangliosides. The A/PR/8 virus bound most effectively to Neu5Ac-containing lacto-series gangliosides carrying type I and type II sugar chains, followed by ganglio-series and hematoside-series gangliosides. The A/PR/8 virus weakly bound to Neu5Ac alpha 2,6lactotetraosylceramide [IV6(Neu5Ac)Lc4Cer] and Neu5Ac alpha 2,6paragloboside [IV6(Neu5Ac)nLc4Cer] carrying Neu5Ac alpha 2,6Gal sequence, although their Neu5Ac alpha 2,3Gal derivatives were the most potent gangliosides tested. B/Lee/40 bound restrictively to IV6(Neu5Ac)Lc4Cer and IV6(Neu5Ac)nLc4Cer, which carry Neu5Ac alpha 2,6Gal sequence, and type I and type II lacto-series sugar chain, respectively. C/Ann Arbor/1/50 reacted only with 9-O-Ac-Neu5Ac-carrying sugar chains in all the gangliosides tested. This method also allowed the microanalysis of receptor gangliosides of unknown samples. ESK cells, sensitive to the influenza A viruses infection, expressed several kinds of receptor active gangliosides, while those from ESK-R cells, resistant to the virus infection, were undetectable.

Binding Sites↗
PubMed1992

Synthesis and biological activities of optical isomers of 2-(4-chlorophenyl)-5,6-dihydro-(1)benzothiepino[5,4-c]pyridazin-3(2H)-o ne 7-oxide.

Two enantiomers of 2-(4-chlorophenyl)-5,6-dihydro-(1)benzothiepino[5,4- c]pyridazin-3(2H)-one 7-oxide ((+/-)-1: Y-23684) were synthesized in high yields by asymmetric oxidation of the synthetic precursor (2) using modified Sharpless reagent. Among the oxidants tested, cumene hydroperoxide (CHP) gave the highest optical and chemical yields, while tert-butyl, tert-amyl, and 1,1,3,3-tetramethylbutyl hydroperoxides did not show such high enantio-selectivities. The absolute configuration of (+)-1 enantiomer synthesized from 2, Ti(O-iso-Pr)4, (-)-diethyl tartarate, and CHP was determined to be S by X-ray crystallographic analysis. Both enantiomers, S-(+)-1 and R-(-)-1, and (+/-)-1 had approximately equivalent in vivo activities to antibicuculline test in mice and anticonflict test in rats, although S-( + )-1 showed about three times higher affinity to benzodiazepine receptor than R-(-)-1 in [3H]diazepam binding assay.

Animals↗
PubMed1992

Use of a beta 2-adrenergic stimulant (clenbuterol) for eliminating night-time calving.

To determine whether beta 2-adrenergic stimulant (clenbuterol) would exhibit beneficial effects upon the elimination of night-time calving, 42 Holstein Friesian cows and heifers at the first stage of labour were injected intramuscularly twice with clenbuterol; 300 micrograms at 18:00 and 210 micrograms at 22:00. Other 26 cows and heifers of the same breed at the first stage of labour at 18:00 were not treated and served as controls. All of the treated animals, but one, calved after 5:00 in the next morning, showing a peak of parturition between 5:00 and 10:00. In contrast to this, 42% of the control animals calved at night between 22:00 and 5:00. Thus, the double administrations of clenbuterol were shown to be effective for eliminating night-time calving. The cows treated with clenbuterol tended to show lower incidences of dystocia and retained placenta and a higher first insemination conception rate than the control animals. No adverse effects of the treatment on the viability of newborn calves and milk yields were observed.

Animals↗
PubMed1992

[Distribution of myocardial damage in patients with hypertrophic cardiomyopathy: evaluation by exercise thallium-201 scintigraphy].

The characteristic of myocardial damage in hypertrophic cardiomyopathy (HCM) was evaluated as to whether the damage is limited to the hypertrophied wall or extends throughout the entire wall. The myocardial damage was detected by exercise thallium-201 (Tl-201) scintigraphy and was evaluated using circumferential profile analysis, calculation of initial uptake and washout rate. Eleven patients with asymmetrical hypertrophy (ASH), whose septal and posterior wall thickness ratio exceeded 1.3 on left ventriculography and biventriculography, and 13 age-matched control subjects without heart disease were studied. The mean values of initial uptake in both groups did not differ significantly, but the washout rate for the entire heart was significantly decreased only in the HCM group (p < 0.05). All of the regional washout rates (antero-septal, apical and postero-lateral) were significantly decreased in the HCM group (p < 0.05), without any difference between the hypertrophied wall and the non-thickened free wall being noted. These results demonstrated that the analysis of myocardial damage by exercise Tl-201 scintigraphy using calculation of the washout rate is a very sensitive means of detecting myocardial damage in HCM, and that such myocardial damage is not restricted to the hypertrophied wall, but rather extends to the entire wall, including the free wall which is not thickened.

Aged↗
PubMed1992

[Coronary revascularization with arterial graft alone].

In the period from December 1989 until July 1991, coronary revascularization were performed on 56 patients using arterial grafts and no venous grafts. The ages of the patients ranged from 43 to 85 years (average; 66.8 years), and there were 33 males and 23 females. Twenty-four patients had angina pectoris, 23 had old myocardial infarction and 9 had acute infarction. There were 3 patients with single-vessel coronary disease, 19 with double-vessel, 31 with triple-vessel and 9 with left main coronary disease. The bypass grafts used were 58 left internal thoracic artery (LITA) grafts, 29 right internal thoracic artery (RITA) grafts, and 56 right gastroepiploic artery (RGEA) grafts. Thus, 143 grafts were used and an average of 2.6 bypasses were created per patient. There were two operative deaths. One of these patients had acute myocardial infarct. Investigation of postoperative graft patency was performed in the 122 grafts that could be examined angiographically after surgery. Only 7 were obstructed, yielding a patency rate of 94.3%. By using both the ITA and RGEA, in situ anastomoses with all the coronary arteries could be performed. Also in emergency surgery arterial grafting was possible. This operative form is considered to be a useful technique and may be expected to produce favorable long-term results.

Adult↗
PubMed1992

[Coronary revascularization with arterial bypass graft as a routine].

In the period from December 1989 until December 1991, coronary revascularization were performed on 68 patients using arterial grafts as a routine. The ages of the patients ranged from 43 to 85 years (average: 67.1 years), and there were 38 males and 30 females. Twenty-seven patients had angina pectoris, 32 had old myocardial infarction and 9 had acute infarction. The bypass grafts used were 69 left internal thoracic artery (LITA) grafts, 39 right internal thoracic artery (RITA) grafts, 68 right gastroepiploic artery (RGEA) grafts and 3 saphenous vein (SV) grafts. Thus, 179 grafts were used and an average of 2.6 bypasses were created per patient. There was only one death in 57 elective operations. Investigation of postoperative graft patency was performed in the 167 grafts that could be examined angiographically after surgery. Only 7 were obstructed, yielding a patency rate of 95.9%. By using both the ITA and RGEA, in situ anastomoses with the most of the coronary arteries could be performed. This operative form is considered to be useful technique and may be expected to produce favorable long-term results.

Adult↗
PubMed1992

[Coronary revascularization using only arterial grafts in patients with left main coronary artery stenosis].

Although increasing use is being made of arterial grafts (internal thoracic arteries and right gastroepiploic artery) for coronary revascularization, application to left main coronary artery (LMT) patients is frequently not possible. During the period from December 1989 to July 1991, coronary revascularization was conducted on 9 LMT patients using only arterial grafts and no venous grafts. The bypass grafts were 6 left internal thoracic artery grafts, 9 right internal thoracic artery grafts and 9 right gastroepiploic artery grafts, a total of 24 grafts and an average of 2.7 bypasses per patient. There were no operated deaths, but five patients required IABP support after cardiopulmonary bypass. They had more than 90% stenotic lesions of left main coronary artery. In contrast, four patients with less than 90% stenotic lesion were uneventful. The cause of these catastrophic hemodynamics was considered reduced blood flow by graft spasm. All patients could be functionally placed in New York Heart Association Class I or II. Postoperative stress tests were made on eight patients and the results were normal in seven. Eight patients have had postoperative angiograms. Twenty-one of 22 grafts were patent. The present results demonstrate that an arterial bypass is possible even on LMT patients by IABP support.

Aged↗
PubMed1992

[Effect of coronary bypass using right gastroepiploic artery--with special reference to their comparative examination in the early stage of postoperative angiographic findings].

In recent years, right gastroepiploic artery (RGEA) has been attracting the attention as the second reliable arterial graft in clinical application. As regards to gastroepiploic artery (GEA), in this report the authors have made the measurement of postoperative graft diameter of RGEA and also demonstrated that postoperative thinning down phenomenon of the diameter of GEA. During the one year and three month-period from December 1989 to March 1991, we have shown coronary bypass (CABG) using GEA performed in 42 cases. The properties of GEA grafts were comparatively examined by postoperative angiographic findings. The results revealed that GEA grafts were satisfactory in patency ratio with the graft diameter measured 2.1 mm (1.2-3.5) as an average. So called string sign was not observed in these cases, but thinning down phenomenon of RGEA being noted in four cases. Then, the thinning down phenomenon of GEA was defined as graft diameter not more than the size of 5F and as not effectively functioning graft flow and was called slender sign. The development of slender sign was caused by good native coronary flow, narrowing of the perfused region and poor run off. Three cases of slender sign due to good native flow did not show any ischemic symptom in these perfused region which meant sufficient blood supply to the myocardium. The long-term patency ratio of RGEA graft should be further followed up.

Aged↗
PubMed1991

A NeuGc-containing trisialoganglioside of bovine brain.

A N-glycolyneuraminic acid containing trisialoganglioside was isolated from bovine brains ganglioside mixture using Q-Sepharose. Its chemical structure was characterized as IV3NeuAc, II3NeuAc-NeuGc, Gg4Cer by gas-liquid chromatography, a permethylation study, sialidase degradation, TLC/enzyme-immunostaining, fast atom bombardment-mass spectrometry, fluorometric HPLC and proton nuclear magnetic resonance spectroscopy. This was unique in the mixed sialic acid constituents. (formula; see text) This accounted for 0.78% of the gangliosides. The ceramide structure was almost identical with those of major bovine brain ganglioside, as mainly composed of 18:0 fatty acid (90.9%) and d20:0 sphingosine base.

Animals↗
PubMed1991

Typing of hepatitis C virus genomes by restriction fragment length polymorphism.

Recently, we reported that hepatitis C virus (HCV) can be classified genetically into two types, HCV-K1 and HCV-K2, which show 67% and 71% identity at the nucleotide and amino acid sequence levels in a 340 bp region which encodes the NS5 gene Gly-Asp-Asp motif. To develop a rapid method to classify the genomes of HCV isolates, we identified restriction fragment length polymorphisms (RFLPs) in reverse transcriptase-polymerase chain reaction products encoding a portion of the NS5 gene. AluI and AccII enabled HCV to be classified into the K1 and K2 types, and Sau96I enabled classification into the K1 type, and the K2a and K2b subtypes. These RFLPs also generally allow Japanese isolates to be distinguished from the prototype (PT, an isolate from the U.S.A.), which is a K1 type. Sequence analysis of the 5'-untranslated regions of Japanese isolates revealed near identity between the K1 type and PT, and 93 to 94% identity between the K1 and K2 types, indicating that there are type K1- and K2-specific RFLPs in this region. Our results suggest that the nucleotide sequences of the K1 and K2 types are different throughout the HCV genome. The incidence of HCV types K1, K2a and K2b, and PT in 50 samples was 74%, 16%, 8% and 2%, respectively.

Base Sequence↗
PubMed1991

[Seroepidemiological study of hepatitis B virus (HBV) infection in the rural community in Kenya--changing pattern of transmission model of HBV in Kenya].

The seroepidemiological study of HBV infection has been done against 9044 inhabitants in order to define a predominant transmission mode and a target population of HBV infection in Kenya. Results are as follows: 1) A total of 379 HBV carriers were identified. The prevalence of HBV carrier ranged from 4 to 9% in adults and 1 to 2% in children under 5 years of age. 2) The prevalences of HBs antigen and anti-HBc antibody in family members of carriers were 2 or 3 times higher than the other population. 3) 60 to 90% of the carrier children under 10 years old was positive for anti-HBe and 10 to 15% of the adult carrier and the pregnant carrier were found to be positive for e antigen. 4) Yearly infection ratio by horizontal route of transmission in the carrier family (1.4%) was 4 times higher than the control groups (0.3%). 5) 49% of the 96 carrier children was born to the carrier mother and in 40% the parent was negative for HBs antigen. 6) E antigen positive carrier mothers were highly infectious against their children than anti-HBe positive carrier mothers and fathers. These results suggest that HBV infection will happen more frequently within the family members of carriers either by horizontal and vertical infection. Marked reduction of carrier rate and infectivity observed in the children under 5 years of age infers that the improved way of mass immunization using disposable needles during infancy will deplete the incidence of horizontal mode of infection and that in the future mother to baby transmission appears to be the main route of HBV infection as in other developed countries.

Adolescent↗
PubMed1991

Studies on the synthesis of condensed pyridazine derivatives. IV. Synthesis and anxiolytic activity of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4- c]pyridazin-3(2H)-ones and related compound.

A series of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4-c]pyridazin-3(2H)- ones and related compounds were synthesized and evaluated for their ability to displace 3H-diazepam from rat brain membranes in vitro, and to prevent bicuculline induced convulsions in mice in vivo. Compounds with a 4'-methoxyphenyl (36) or 4'-chlorophenyl group (37, 39--42) as 2-aryl substituents showed prominent activities in both the in vitro and in vivo tests. Among them, 2-(4'-chlorophenyl)-5,6-dihydro- (37) and 2-(4'-chlorophenyl)-5,6-dihydro-10-fluoro-(1)benzothiepino[5,4-c]+ ++pyridazin- 3(2H)-one 7-oxides (41) showed activity twice as potent as diazepam in an anticonflict test (Vogel type, rats) while exhibiting less muscle relaxation (rotarod test, mice) and augmentation of gamma-aminobutyric acid-induced chloride current (Icl) in isolated frog sensory neurones than diazepam. Compound 37 (Y-23684) was selected from this series as a candidate for further development. The structure-activity relationships are discussed.

Animals↗
PubMed1991

Estimation of whole-body RNA catabolism based on the urinary modified nucleoside levels of cancer and AIDS patients.

From the relationship between the molar ratio of nucleosides calculated stoichiometrically from modified nucleoside occurrences in major RNA species and the proportion of rRNA to all of RNA contents in average tissues, the increase of rRNA contents in cancer tissues growing rapidly was found. Thus, we found that selected urinary modified nucleoside levels were very useful as a biological marker of cancer and AIDS, as well as a good indicator of whole-body metabolic conditions of RNAs.

Acquired Immunodeficiency Syndrome↗