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Biomedical subjects

T Baba

Publications and source records attributed to T Baba.

At least 433 records · Page 24Linked to original sources
PubMed1988

Effect of cimetidine on the pharmacokinetics and pharmacodynamics of enalapril in normal volunteers.

The possible effects of cimetidine on the pharmacokinetics and pharmacodynamics of enalapril, a pro-drug requiring hepatic de-esterification to an active angiotensin-converting enzyme (ACE) inhibitor enalaprilat, were assessed in a randomized, crossover study. Cimetidine (400 mg) or placebo was administered orally every 12 h for 3 days and on the day of a single oral administration of enalapril maleate (10 mg) to seven healthy male subjects. Serum ACE, plasma renin activity (PRA), plasma aldosterone concentration (PAC), and alpha-human atrial natriuretic peptide (alpha-hANP) were measured before and 4 h after the enalapril dosing. There were no significant differences in any serum- and urine-derived kinetic parameters of enalapril and enalaprilat, nor in hemodynamics, PAC, or alpha-hANP between the two treatment trials. ACE decreased and PRA increased to a similar extent in the two trials. Serum enalaprilat concentration correlated significantly (p less than 0.001) with percentage of inhibition of ACE activity. The results suggest that the pharmacokinetics and pharmacodynamics of enalapril are unaffected by preadministration of cimetidine. Thus, cimetidine does not appear to alter hepatic esterase activity toward enalapril.

Adult↗
PubMed1988

Structure and molecular species composition of three homologous series of alpha-mycolic acids from Mycobacterium spp.

Three homologous series of alpha-mycolic acids (dicyclopropanoyl acids, monocyclopropanoyl monoenoic acids and dienoic acids) from 16 rapidly growing and 14 slowly growing mycobacteria were separated by argentation thin-layer chromatography and analysed by gas chromatography/mass spectrometry of their trimethylsilyl ether derivatives. Mycobacterial species were separated into five groups. Strains of group A contained similar amounts of even and odd carbon-numbered dienoic acids, with a methyl branch on the odd acids and a C24-alpha-unit, as typified by Mycobacterium fortuitum and M. chitae. Group B strains possessed similar amounts of even carbon-numbered dicyclopropanoyl alpha-mycolic acids and odd carbon-numbered unsaturated acids with C22- and C24-alpha-units, as found in M. phlei and M. diernhoferi. Group C strains contained mainly even carbon-numbered dicyclopropanoyl acids with C22- and C24-alpha-units, as shown by M. vaccae and M. aurum. Group D strains possessed mainly odd carbon-numbered dienoic acids with a methyl branch and a C24-alpha-unit, as seen in M. triviale and M. nonchromogenicum. Group E strains had mainly even carbon-numbered dicyclopropanoyl acids with C24- or C26-alpha-units, as found in M. avium and M. tuberculosis. Many rapidly growing mycobacteria also produced alpha'-mycolic acids which were shorter in the length of the main carbon chain but whose alpha-units were the same as those in alpha-mycolic acids from the same species. These alpha'-mycolic acids had either one or two double bonds and showed variations in both their unsaturation and overall size, which may be useful in taxonomic studies.

Carboxylic Acids↗
PubMed1988

Clinical, electrophysiological, and histopathological observations in supraventricular tachycardia.

Fifty patients with supraventricular tachycardia (SVT) underwent clinical electrophysiological studies (EPS), endomyocardial biopsies and cardiac catheterizations. EPS revealed AV nodal reentrant tachycardia (AVNRT) in seven patients, AV reentrant tachycardia utilizing concealed AV bypass tracts (AVR-CBT) in nine patients, AV reentrant tachycardia utilizing AV bypass tracts with ventricular preexcitation (manifest WPW) in 13 patients, sinus nodal or intra-atrial reentrant tachycardia (SNRT or IART) in three patients, atrial flutter (AF) in nine patients, automatic atrial tachycardia (AAT) in five patients, and multifocal atrial tachycardia (MAT) in four patients. According to the clinical observations, three patients with AVNRT (43%), six with AVR-CBT (67%), six with manifest WPW (46%), two with SNRT or IART (67%), eight with AF (89%), two with AAT (40%), and two with MAT (50%) showed other accompanying clinical abnormalities. In all patients who were studied histologically, changes in the myocardium were seen; myocarditic changes, postmyocarditic changes and nonspecific abnormalities were present in six (12%), 15 (30%), and nine (18%) respectively. Myocardial changes were observed in four out of seven cases with AVNRT (57%), in six out of nine with AVR-CBT (67%), in five out of 13 with manifest WPW (38%), in two out of three with SNRT or IART (67%), in six out of nine with AF (67%), in all five cases of AAT (100%), and in two out of four with MAT (50%). Nineteen out of 32 without clinical abnormalities except for arrhythmias (59%) had myocardial changes (six had myocarditic changes, ten had postmyocarditic changes, and three had nonspecific abnormalities). On the other hand, nine out of 21 with myocarditic or postmyocarditic changes were accompanied with various arrhythmias other than SVT (two had SSS, five had AV block or rBBB, and two had VT). Elevated LVEDP was present in 36% of the group with normal myocardium and in 53% of the group with myocardial changes. However, the low EF was shown in no patients with normal myocardium but in 21% of the group with myocardial changes. The low CI was also shown in only 9% of the group with normal myocardium but in 28% of the group with myocardial changes. These results suggest that patients with SVT may exhibit several histopathological changes in the myocardium, even in the absence of any clinical organic heart disease.

Adult↗
PubMed1988

Ultrastructural visualization of selective peanut agglutinin binding sites in rat osteoclasts.

We investigated the distribution of concanavalin A (ConA)-reactive alpha-D-mannosyl and alpha-D-glucosyl groups and peanut agglutinin (PNA)-reactive beta-D-galactose-(1----3)-N-acetyl-D-galactosamine residues on the surface of osteoclasts with pre-embedment ultrastructural lectin cytochemistry after aldehyde fixation of the metaphyses of the rat tibiae. By routine morphology, the plasma membrane of the ruffled border of the osteoclast was distinguished from the rest of the cell membrane, with the exception of the membrane of coated pits, by its characteristic thick coat at its cytoplasmic surface. Cytochemistry, using ConA in combination with horseradish peroxidase (ConA-HRP) and PNA conjugated to HRP, showed that binding of ConA was distributed over the entire cell surface of osteoclasts. In contrast, intense binding of PNA was limited to the membranes of the ruffled border and coated pits, whereas the remainder of the cell membrane stained weakly or not at all. These results demonstrate that preferential PNA binding sites of the cell surface correspond to coated membranes associated with osteoclastic endocytosis.

Animals↗
PubMed1988

Participation of cytochrome P-450 isozymes in N-demethylation, N-hydroxylation and aromatic hydroxylation of methamphetamine.

1. Five isozymes of cytochrome P-450 were purified from liver microsomes of phenobarbital-pretreated (P-450-SD-I and -II), 3-methylcholanthrene-pretreated (P-450-SD-III) and untreated rats (P-450-SD-IV and -V) to determine their catalytic activities in metabolic reactions of methamphetamine. 2. All the isozymes except P-450-SD-III showed considerably high N-hydroxylating activity of methamphetamine. The cytochromes P-450 initiate N-demethylation of this drug by two metabolic pathways, C-hydroxylation and N-hydroxylation. 3. Both N-demethylation and N-hydroxylation of methamphetamine were efficiently catalysed by the phenobarbital-inducible forms P-450-SD-I and -II and constitutive forms P-450-SD-IV and -V. 4. The constitutive forms P-450-SD-IV and -V revealed high catalytic activities of p-hydroxylation of methamphetamine, but phenobarbital- and 3-methylcholanthrene-inducible isozymes showed only low activities. 5. The present results indicate that the different extents of the metabolic intermediate complex formation with cytochrome P-450 (455 nm complex) in the microsomes from phenobarbital-, 3-methylcholanthrene-pretreated, and untreated rats is not attributable to the activities of the respective isozymes of cytochrome P-450 to form the precursor of the complex, N-hydroxymethamphetamine.

Animals↗
PubMed1988

[Screening for antagonistic agents to the lethal toxicity of neocarzinostatin. II. Effects of various drugs in inhibiting the toxicity of neocarzinostatin in vivo].

In clinical chemotherapy with neocarzinostatin (NCS) against cancers, side effects such as leukopenia, anorexia, vomiting and nausea were mainly observed when parenteral administration was used. To prevent these adverse side effects without changing the anticancer activity of the drug, we attempted to apply the two-route-infusion chemotherapy using NCS and antidotes for the NCS treatment devised by Baba. This report presents the results of our study on effects of some antidotes on the acute toxicity of NCS in mice and also on the antitumor activity of NCS against Sarcoma-180 in mice (ICR-JCL strain) when used with tiopronin. The results are summarized as follows. 1. LD50 values of NCS administered via intravenous route increased 2.3- to 3.2-fold when 150, 300, 500 or 1,000 mg/kg of tiopronin was administered subcutaneously together with NCS, 1.3- to 1.4-fold when 50 or 100 mg/kg of sodium thioglycolate was used. When antidotes were given prior to the administration of NCS, 1.8- to 5.4-fold increase in LD50 values of NCS resulted with 300, 500 or 1,000 mg/kg of tiopronin administered 1 hour prior to NCS, 2.3-fold increase resulted with 2,000 mg/kg reduced glutathione, 1.2-fold increase with 100 mg/kg of sodium thioglycolate and 1.9-fold increase with 1,000 mg/kg of L-cysteine monohydrochloride monohydrate. Furthermore, 4.8- to 13.1-fold increase in LD50 of NCS occurred when 150, 300, 500 or 1,000 mg/kg of tiopronin was administered 15 minutes prior to NCS. When these antidotes were administered 1 hour after the administration of NCS, however, no changes in the LD50 value occurred. 2. The LD50 value of NCS given intraperitoneally increased 1.6- to 5.8-fold when 150, 300, 500 or 1,000 mg/kg of tiopronin was administered intravenously at the same time as NCS, 1.4- to 1.6-fold when tiopronin was given 1 hour prior to NCS, intraperitoneally and 1.3- to 1.7-fold when it was given 1 hour after NCS. 3. It was recognized that the acute toxicity of NCS was the most effectively reduced by tiopronin, but only slightly by glutathione, sodium thioglycolate or L-cysteine monohydrochloride monohydrate. The action of tiopronin was the most effective when it was given subcutaneously 15 minutes prior to NCS administered intravenously. 4. The combination chemotherapy on Sarcoma-180 in mice using NCS intraperitoneally and tiopronin intravenously was markedly effective when these agents were given simultaneously.

Amino Acids, Sulfur↗
PubMed1988

[Controlled study of MQF-OK therapy with FT and with UFT on various advanced gastrointestinal cancers. Hirosaki Cooperative Study Group of Cancer Chemotherapy].

Our cooperative study group carried out a controlled study of MQF-OK therapy with tegafur (FT) (group A) and with UFT (group B), a compound of FT and uracil in the molar ratio of 1:4, on various advanced gastrointestinal cancers. From January 1985 to May 1987, 91 patients were entered into this study, and 11 cases were ineligible for the protocol (11%). Fifty of 80 cases had advanced gastric cancer, 30 had pancreatic cancer or other cancers, such as colon cancer, and biliary tract cancer. They were divided into group A or B at random. There was no difference in the patient characteristics between group A and B. In gastric cancer, 23 of 50 cases were randomized into group A and 27 cases into group B. Two cases in group A (8.7%) and 7 cases in group B (25.9%) showed PR. The response rate of group B was better than that of group A, but the value of P by Kruskal-Wallis test was 0.27. Thirteen of the 30 other cancers were randomized into group A and 17 cases into group B. Three cases in group A and B, respectively, showed PR. There was no significant difference between the two groups in terms of antitumor effect, prolongation of life or side effects. In conclusion, it was suggested that the MQF-OK therapy with UFT was beneficial for the Remission Induction Therapy in advanced gastric cancer.

Adult↗
PubMed1988

Harderian gland dependency of immunoglobulin A production in the lacrimal fluid of chicken.

Involvement of the Harderian gland (HG) in the production of lacrimal immunoglobulin (especially IgA) was investigated. The lacrimal concentration of each immunoglobulin class was not affected by surgical bursectomy but was reduced by cyclophosphamide (CY) and testosterone (TP) treatments. Surgical removal of the Harderian gland caused a remarkable reduction of both the lacrimal concentration of each immunoglobulin class and the specific antibody titre, and and IgA was almost undetectable. The lacrimal concentration of each immunoglobulin class, as well as the specific antibody titre, was not affected by surgical removal of the Lacrimal gland (LG). The route of antigen administration produced no difference in the class of lacrimal immunoglobulin produced. The results indicate that the production of immunoglobulin in chicken tears may be dependent on the HG and that lacrimal immunoglobulin may be synthesized and secreted locally in the HG. Lymphocytes of the HG are of bursa of Fabricius origin and are seeded into the HG prior to hatching and its lymphocytes do not appear to be involved in systemic immunity.

Aging↗
PubMed1988

[Relationship between angiographical manifestations and operative findings in 100 cases of hemifacial spasm].

Relationship between angiographical manifestations and operative findings of hemifacial spasm was studied in 100 cases. Vertebral angiography was performed, and Towne, straight AP, and lateral projections were routinely studied. The anterior inferior cerebellar artery (AICA) directly compressed the facial nerve root exit zone in 54 instances, the posterior inferior cerebellar artery (PICA) in 38, and the vertebral artery (VA) in 11. Compressions by multiple vessels were observed in 3 cases. Anatomical variations of the AICA and the PICA were classified into 3 groups according to their origins and their distributions of blood supply: Type I, normal distribution of AICA and PICA; Type II, common trunk anomaly with dominant AICA (basilar artery origin); and Type III, common trunk anomaly with dominant PICA (vertebral artery origin). In our cases, 35% of them showed normal distribution, 34% dominant AICA, and 35% dominant PICA. Analyses of the angiograms revealed significantly increased numbers of common trunk anomalies when compared with normal angiograms studied by Takahashi. In 60 of the 65 cases with common trunk anomalies, facial nerves were compressed by the main trunk or the branches of the dominant artery. There were 35 cases which belonged to Type I anatomical classification. They were subdivided into 2 groups according to the size of the AICA and PICA: 1. AICA greater than PICA, and, 2. PICA greater than AICA. In the AICA greater than PICA subgroup, the AICA was the offending artery in all but one case. In the PICA greater than AICA subgroup, the PICA was responsible in 9 of 17 cases. In 31 cases, angiograms showed a redundant VA with lateral elongation into the cerebellopontine angle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗