Biomedical subjects

T Aoyagi

Publications and source records attributed to T Aoyagi.

At least 127 records · Page 7Linked to original sources

PubMed1996

Piperastatin B: a new selective serine carboxypeptidase inhibitor from Streptomyces lavendofoliae MJ908-WF13.

Piperastatin B, a new inhibitor of serine carboxypeptidase was purified from a culture broth of Streptomyces lavendofoliae MJ908-WF13 as a minor component by monitoring its inhibitory activity against carboxypeptidase Y (CP-Y). Its structure was determined to be N-formyl-Val-Thr-Leu-Val-Pip-Leu-Pip (pip: piperazic acid, hexahydropyridadine-3-carboxylic acid). Piperastatin B is a highly specific competitive inhibitor of CP-Y (Ki = 55 nM) with little effect on related enzymes and resembles the major component, piperastatin A, in these respects.

Amino Acids↗

PubMed1996

Poststatin, a new inhibitor of prolyl endopeptidase. VIII. Endopeptidase inhibitory activity of non-peptidyl poststatin analogues.

Non-peptidyl postatin analogues, (S)-N-substituted-2-[2-(1-acylpyrrolidinyl)]-2-oxoacetamides were synthesized and examined for their inhibitory activity against prolyl endopeptidase and cathepsin B in vitro. Many compounds showed stronger activity than natural poststatin, a pentapeptide. Among them, (S)-N-cyclohexyl-2-oxo-2-[2-(1-(3-phenoxybenzoyl)pyrrolidinyl)]ace tamide (22) and (S)-N-cyclohexyl-2-[2-(1-(2-naphthoyl)pyrrolidinyl)]-2-oxoacetamide++ + (19) indicated IC50 value of 5.8 and 8.2 ng/ml for prolyl endopeptidase inhibition respectively. None of these compounds possess significant inhibitory activities against cathepsin B, a cysteine protease. These results indicate that these compounds are more selective inhibitors against prolyl endopeptidase than is natural poststatin.

Magnetic Resonance Spectroscopy↗

PubMed1996

Poststatin, a new inhibitor of prolyl endopeptidase. III. Optical resolution of 3-amino-2-hydroxyvaleric acid and absolute configuration of poststatin.

3-Amino-2-hydroxyvaleric acid was prepared, and separated into its diastereomers. The relative stereochemistry was determined by 1H NMR in their oxazolidone derivatives. The threo-isomer was resolved by (S)-1-(1-naphthyl) ethylamine in the N-(p-methoxybenzyloxycarbonyl) derivative. The absolute configuration of (--)-threo-3-(p-methoxybenzyloxycarbonyl)amino-2-hydroxyvaleric acid was confirmed to be 2R, 3S. The absolute configuration of 3-amino-2- oxovaleric acid in poststatin was confirmed to be S by comparison of the four stereoisomers of methyl N, O-bis(3,5-dinitrobenzoyl)-3-amino-2-hydroxyvalerate derived from 3-amino-2-hydroxyvaleric acid and that derived from 3-amino-2-oxovaleryl moiety of poststatin by means of HPLC with chiral column.

Amino Acid Sequence↗

PubMed1996

Poststatin, a new inhibitor of prolyl endopeptidase. IV. The chemical synthesis of poststain.

Total synthesis of poststatin was achieved by both liquid phase and solid phase methods. In both methods, the (2R,3S)-3-amino-2-hydroxyvaleric acid moiety was incorporated into protected pentapeptides, and was oxidized to (S)-3-amino-2-oxovaleric acid (postine). Deprotection of the oxidized pentapeptides gave a specimen identical with natural poststatin in physico-chemical properties and prolyl endopeptidase inhibitory activity.

Amino Acid Sequence↗

PubMed1996

Poststatin, a new inhibitor of prolyl endopeptidase. V. Endopeptidase inhibitory activity of poststatin analogues.

Thirty analogues of poststatin were synthesized, and their inhibitory activities against prolyl endopeptidase, human leukocyte elastase and cathepsin B were measured. The alpha-ketone was essential and the S configuration was preferable to the R configuration in the beta-substituted-beta-amino-alpha-oxopropionic acid moiety of poststatin analogues for endopeptidase inhibitory activity. The analogue in which the D-leucine residue of poststatin was replaced by L-leucine showed strong inhibitory activity to cathepsin B. Introduction of an aromatic group into the P4 position and proline into the P2 position increased inhibitory activity to elastase. Benzyloxycarbonyl-L-homophenylalanyl-(RS)- 3-amino-2-oxovaleryl-D-leucyl-L-valine was about 6 times more active to prolyl endopeptidase than natural poststatin.

Cathepsin B↗

PubMed1996

Poststatin, a new inhibitor of prolyl endopeptidase. VI. Endopeptidase inhibitory activity of poststatin analogues containing pyrrolidine ring.

Several pyrrolidine-containing analogues of poststatin were synthesized and examined for their inhibitory activity against prolyl endopeptidase and cathepsin B in vitro. Replacement of the postine residue with 2-oxo-2-(2-pyrrolidinyl)acetic acid increased the selectivity and inhibitory activity against prolyl endopeptidase. Benzyloxycarbonyl-L-phenylalanyl-(S)-2-oxo-2- (2-pyrrolidinyl)acetyl-D-phenylalanine was about 46 times as active to propyl endopeptidase as natural poststatin.

Cathepsin B↗

PubMed1996

Poststatin, a new inhibitor of prolyl endopeptidase. VII. N-cycloalkylamide analogues.

Poststatin analogues containing (S)-2-oxo-2-(2-pyrrolidinyl)acetyl moiety in P1 were synthesized and examined for their inhibitory activity against prolyl endopeptidase and cathepsin B in vitro. Introduction of non-peptidyl cycloalkylamine component in P1, was effective and P3-acyl groups must be widely modifiable for prolyl endopeptidase inhibition. Acyl-L-phenylalanyl-(S)-2-oxo-2-(2-pyrrolidinyl)acetyl-cycloalkylamid e type compounds showed IC50 value of nano to subnano g/ml as prolyl endopeptidase inhibitor and were shown no significant inhibitory activities against cathepsin B, a cysteine protease.

Cathepsin B↗

PubMed1996

[A case of AIDS with bronchial tuberculosis].

A case is 48 years-old Japanese man who had a history of frequent sexual contact with prostitutes in Thailand and the Philippines. He presented with chief complaint of chest discomfort in April 1995. His chest X-ray film showed right mediastinal lymph node swelling in other hospital and the sputum smear was strongly positive for acid fast bacilli. In May 1995, he was admitted to our hospital and serological tests for HIV were positive both by EIA and Western blot methods. The CD4 lymphocyte count was 167/microliters. He was diagnosed as a case of AIDS according to the criteria proposed by the AIDS surveillance committee of the Japanese Ministry of Health and Welfare. Although numerous tubercule bacilli were detected in sputum, the chest X-ray did not show abnormal shadow in lung fields. So the diagnosis of bronchial tuberculosis was suspected by these apparently contradictory findings and the bronchoscopy was performed. Biopsy specimen of the bronchial mucous membrane obtained by bronchoscopy confirmed the presence of acid fast bacilli by Ziehl-Neelsen's staining method, however, histological findings were atypical of tuberculosis. A month after the initiation of treatment with isoniazid, rifampicin and ethambutol and AZT, his clinical symptoms improved and the sputum smear and the culture tests for tubercule bacilli converted to negative. Complications of AIDS, (Pneumocystis carinii infection, Cytomegalo virus infection, Kaposi's sarcoma, etc) other than tuberculosis have not developed to date. In the past reports, we could not find reports of bronchial tuberculosis with AIDS. Tuberculous granuloma formation was scarce in this case, and it was suspected that bronchial tuberculosis with AIDS would show characteristic sign as same as pulmonary tuberculosis with AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Effect of herbimycin A on renal cancer cell growth.

We investigated the effect of herbimycin A on the monolayer growth of 4 human renal cell carcinoma (RCC) cell lines and a normal renal tubular cell line (RTC 13) using MTT [3-(4,5-dimethylthiszol-2,5-diphenyl tetrazolium bromide)] assay. Herbimycin A induced remarkable growth inhibition in each RCC cell line tested, without any morphological changes of the cells. At the concentration of 500 ng/ml, herbimycin A caused more than a 30% growth inhibition in all RCC cells (p < 0.005 vs RTC 13), while less than 7% growth inhibition was observed in RTC 13 at the same herbimycin A concentration. The cell cycle was estimated by analysing DNA (deoxyribonucleic acid) content using a FACS. A DNA histogram of RCC cells treated at herbimycin A showed a block in the cell cycle at the S and G2M phases. However, little effect by herbimycin A on RTC 13 cells was observed. Our results suggest that protein tyrosine kinases inhibitors, like herbimycin A, may offer a new treatment option for RCC patients.

Antibiotics, Antineoplastic↗

PubMed1996

[Histopathological prognostic factors in 146 patients with renal cell carcinoma: comparison between incidental and non-incidental cases].

To characterize the prognostic factors among pathological structural pattern, cell type, infiltration, and incidental or non-incidental renal cell carcinoma (RCC), we reviewed the records of 146 patients with RCC who underwent nephrectomy at our institute. The patients were 26 to 86 years old (mean age 58). The men-to-women ratio was 3.2:1. The tumor originated in the right kidney in 83 patients and in the left in 63. The solid pattern was associated with poorer survival than other patterns (p < 0.01). Spindle or pleomorphic cell type had poorer survival than common type (p < 0.01). The number of incidentally discovered RCC has increased since 1986, and survival is better than in non-incidental RCC, because of smaller tumor size, low stage tumor (stages 1, 2; 83.6%), and fewer papillary or solid type. In addition, there were no spindle or pleomorphic cell type, grade 3 or INF gamma-positive case. Survival is good even when the tumor is large.

Adult↗

PubMed1996

Increased circulating serum amyloid A protein derivatives in rheumatoid arthritis patients with secondary amyloidosis.

Secondary amyloidosis, a serious complication of chronic inflammatory diseases, is caused by the deposition of amyloid fibrils in various organs. The major component of amyloid fibrils is derived from serum amyloid A protein (SAA) by proteolysis. To explore the mechanisms of amyloidogenesis, we measured SAA concentrations in the sera of 38 patients with rheumatoid arthritis (RA) without secondary amyloidosis and in the sera of 18 RA patients with secondary amyloidosis, using the latex agglutination immunoassay. We also determined whether SAA was present as a full-length protein in the sera of RA patients by immunoblotting. Although SAA concentrations were elevated in the sera, there were no significant differences in these concentrations between RA patients without amyloidosis (128.2 +/- 145.4 micrograms/ml) and RA patients with amyloidosis (165.0 +/- 162.9 micrograms/ml). To test for qualitative abnormalities of SAA, the isolated SAA proteins from individual RA patients were analyzed by anti-SAA immunoblot. In addition to full-length SAA protein, 6-kd and 4.5-kd SAA-derived fragments were detected in the sera of RA patients, and the ratio of these fragments to total SAA proteins was significantly higher in RA patients with amyloidosis (37.0% +/- 0.7%) compared with that of RA patients without amyloidosis (15.0% +/- 5.5%). Although a high serum level of SAA is a predisposing condition for amyloid formation in RA patients, our data suggest that the increased circulating proteolytic cleavage of SAA may potentially contribute to the development of AA-amyloid deposition.

Adult↗

PubMed1996

[A study on prevalence of resistance to antituberculosis drugs in Japan: comparison of results in the local facilities and in the reference laboratory].

During five years since the last survey of drug-resistant tuberculosis in Japan, features of tuberculosis in Japan have been changed. A nationwide survey was conducted by the Tuberculosis Research Committee of Japan. A total of 38 hospitals in various districts of Japan participated in the cooperative study. Each collaborating laboratory sent all mycobacterial cultures isolated during 1 June to 30 November, 1992 to the reference laboratory of the Committee, where species of the isolates were identified and drug susceptibility of Mycobacterium tuberculosis isolates were reexamined. The reference laboratory received a total of 1,236 cultures. Among them, 290 cultures were excluded from further examination by various reasons, such as contamination (52 cultures), non-viability (53), growth of nontuberculous mycobacteria (182) and other reasons (3). Thus, drug susceptibility test results were available for 946 cultures, including 26 cultures from non-Japanese persons. In the local laboratories, two methods, the absolute concentration method using 1% Ogawa egg slant (standard method, 26 hospitals) and its modified method using a microwell plate (microtiter method, 12 hospitals), were used for drug susceptibility testing, and the standard method was used in the reference laboratory. The results in the local laboratories were compared with those in the reference laboratory. The overall coincidence rate between drug susceptibility results reported from the local laboratories and those from the reference laboratory was 92.5%. A high coincidence rate (94.3%) was seen when the standard method was used in both local and reference laboratories. On the other hand, the coincidence rates between the results with the microtiter method in the local laboratory and those with the standard method in the reference laboratory were lower (standard method vs microtiter method; P < 0.01). Out of 19 hospitals, when the isolates were tested by the standard method 17 (89.5%) showed high coincidence rates (over 85%). Three hospitals using the microtiter method showed the coincidence rate over 90%, while other three showed lower rate (less than 80%) with high overestimation rates (over 19%), indicating that there are variations among facilities in performing the microtiter test. A part of the results concerning the resistance patterns to five antituberculosis drugs will be reported elsewhere.

Adolescent↗

PubMed1996

[Detection of Mycobacterium tuberculosis in clinical specimens other than sputum by the Mycobacterium Tuberculosis Direct Test (MTD)--assessment of sample preparation methods and clinical evaluation].

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) has been widely used as a rapid test for the identification of Mycobacterium tuberculosis complex in clinical samples, and several research groups have verified its clinical usefulness. However, most of the specimens they tested were sputum, and there have been few reports on other specimens. In particular, there have been no reports on assessments of methods of preparing samples other than sputum for the MTD. We assessed methods of preparing samples other than sputum and the influence of a local anesthetic and an anticoagulant that may be present in samples, and also evaluated the MTD as a means of detecting M. tuberculosis in pleural fluid, bronchial lavage cerebrospinal fluid, urine and ascitic fluid. 1. Assessment of three sample preparation methods, i.e., the NALC-NaOH method GuSCN-Diatom nucleic acid extraction method, and the ultrasonication method, revealed that the combination of the NALC-NaOH method and the ultrasonication method, widely used to prepare sputum samples, is also a valid method of preparing other samples. 2. The local anesthetic and the anticoagulant used clinically and remained in specimens did not affect the results of the MTD. 3. Seven (36.8%) of 19 pleural fluid samples from patients diagnosed as tuberculous pleurisy were positive of M. tuberculosis by the MTD, while five (27.8%) of 18 pleural fluid samples cultured for bacteria were positive for M. tuberculosis complex. None of the 20 pleural fluid samples from patients diagnosed as non-tuberculous pleurisy were positive for M. tuberculosis complex either by MTD or culture. 4. Eight (32.0%) of 25 bronchial lavage samples from patients diagnosed as pulmonary tuberculosis were positive for M. tuberculosis complex by the MTD, while 3 (12.0%) were positive by culture. None of the 18 bronchial lavage samples from patients diagnosed as non-tuberculous disease were positive for M. tuberculosis complex either by the MTD or culture. Based on these results, it is concluded that the MTD is a very useful method of detecting M. tuberculosis in clinical samples other than sputum because it is more sensitive than culture on Ogawa's egg medium in detecting M. tuberculosis complex in pleural fluid samples, bronchial lavage samples, and so on, with the same preparation method as used for sputum.

Bacteriological Techniques↗

PubMed1996

[Evaluation of a new detection method of Mycobacterium tuberculosis in clinical specimens by amplification of ribosomal RNA and its clinical application].

A new rapid M. tuberculosis detection method, the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD), which allows direct detection of M.tuberculosis in clinical specimens by amplification of M.tuberculosis ribosomal RNA (rRNA), was evaluated. In the present study, MTD and conventional smear and culture examinations were performed on 225 sputum, 36 pleural fluid (PF), nine cerebrospinal fluid (CSF) and 41 bronchoalveolar lavage fluid (BALF) specimens. Among 225 sputum specimens from 132 patients, 20 culture-negative specimens from 14 patients and one specimen which was culture-positive for M.fortuitum on Ogawa's egg medium were MTD-positive. On the other hand, there were 6 M.tuberculosis culture-positive but MTD-negative specimens from 6 patients. The amount of bacilli in all six cases, however, was very few. The sensitivity of M.tuberculosis detection by MTD, as compared with Ogawa's egg medium and MB-Check, was 93 and 92%, respectively, in sputum specimens, and the specificity of MTD was 80 and 85%, respectively. Taking into account not only culture-positive specimens but also MTD-positive specimens from patients clinically diagnosed as active tuberculosis, the sensitivity and specificity of MTD were 93% and 99%, respectively. Among 36 PF specimens from 31 patients, of which 20 specimens from 16 patients were clinically diagnosed as tuberculous, only 4 from 4 patients were culture-positive for M.tuberculosis while 7 from 5 patients were MTD-positive. The results of MTD in 9 CSF specimens coincided well with those of MB-Check, but one MTD-positive specimen yielded a false-negative result with Ogawa's egg medium. Among 41 BALF specimens from 39 patients, only one was culture-positive while one culture-positive and 7 culture-negative specimens were positive on MTD. All these MTD-positive patients were later verified as having pulmonary tuberculosis either by transbronchial lung biopsy and other examinations, or by the clinical course of the disease, particularly the response to anti-tuberculosis drugs. Inconsistent results were seen in 21 sputum specimens from 15 patients, 4 PF specimens from 3 patients and 7 BALF specimens from 7 patients, all of which were culture-negative for M.tuberculosis but MTD-positive. None of these patients had any clinical findings inconsistent with diagnosis as tuberculosis. It was noted that MTD was very useful for rapid detection of M.tuberculosis in sputum as well as other clinical specimens. We observed the clinical course of 20 pulmonary tuberculosis patients by monthly examinations of sputum, using smears, Ogawa's egg medium, MB-Check and MTD. MTD-positivity rates fell down in parallel with decreased pulmonary tuberculous activity. During the clinical course, out of 61 MTD-negative specimens only 4 (6.6%) were culture-positive for M.tuberculosis, while out of 63 smear-and-culture-negative specimens 6 (9.5%) were MTD-positive. These data suggest that MTD is useful to assess the clinical activity and course of tuberculosis.

Adult↗

PubMed1996

Increased population of high fluorescence 1F7 (CD26) antigen on T cells in synovial fluid of patients with rheumatoid arthritis.

OBJECTIVE: To investigate the activation of T cells in peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA). METHODS: The expression of CD26 (Ta1 and 1F7) antigen on T cells was analyzed in 7 women with RA and 7 healthy control subjects by immunofluorescence. RESULTS: The percentage of CD3+ CD26+ cells was significantly higher in PB of patients with RA compared with healthy subjects. The IF7+ cell population was divided into high (1F7+high cells) and low fluorescence populations (1F7+low cells), based on 1F7 antigen density. The percentage of 1F7+high cells in SF of RA was markedly increased compared with PB of patients and healthy subjects. However, RA SF contained lower percentages of whole 1F7+ cells compared with PB. CONCLUSION: Our results indicate that SF of patients with RA contains activated T cells, and suggest that T cells with high levels of CD26 antigen may preferentially migrate into the rheumatoid synovium to induce inflammation and tissue destruction.

Adult↗

PubMed1996

[Two cases of pulmonary disease caused by Mycobacterium chelonae subsp. abscessus].

We encountered two-cases of pulmonary disease caused by M. chelonae subsp. abscessus, [Case 1] A 72-year-old man was admitted to the hospital because of fever. He had been observed for one year after being given a diagnosis of pulmonary disease caused by Myocobacterium avium complex. Sputum examination revealed acid-fast bacilli (Gaffky 9). He recovered after administration of clarithromycin (CAM) and other drugs. [Case 2] A 61-year-old man was admitted to the hospital because of coughing and sputum production. He had been observed for 4 years after being given a diagnosis of pulmonary M. fortuitum disease. Sputum examination revealed acid-fast bacilli (Gaffky 7). His symptoms deteriorated even though he received anti-tuberculosis agents and CAM. After measurement of minimal inhibitory concentration (MIC), he was given amikacin (AMK). In both cases, the bacilli found in sputum obtained on admission were identified as M. chelonae subsp. abscessus by DNA hybridization. They were completely resistant to all anti-tuberculosis agents. However, the disk method show that they were sensitive to AMK, imipenem and CAM. The MIC value of those strains to CAM was 0.78 microgram/ml in case I and more than 100 micrograms/ml in case 2. The results obtained by MIC measurement were consistent with the clinical outcome. AMK, cefoxitin (CFX), and CAM had been used to treat M. chelouae subsp. abscessus in Europe, but the MIC value differed from strain to strain within a species. Thus the present data suggest that measurement of the MIC value of CAM would be necessary to predict its therapeutic effect.

Aged↗

PubMed1996

[Serodiagnosis of tuberculosis by detection of antituberculous glycolipid antigen (TBGL antigen) antibodies in serum using enzyme-linked immunosorbent assay: clinical evaluation of anti-TBGL antibodies assay kit].

Kyowa Medex Co., Ltd. developed the kit for the sero-diagnosis of tuberculosis, which detects IgG antibodies against tuberculous glycolipids antigen containing cord factor (TBGL antigen) prepared from M. tuberculosis using the enzyme-linked immunosorbent assay technique. We evaluated the kit using clinical specimens and the results are as follows: 1) In total, 34 out of 39 cases (87.2%) with active pulmonary tuberculosis showed positive anti-TBGL antibody. 2) Patients with cavity, patients with extensive lesions and patients excreting large amount of acid fast bacilli tended to show high positivity rates. 3) The antibody titers increased in 7 out of 11 cases after starting the antituberculous chemotherapy. 4) The use of the antibody is unsuitable for the determination of the activity of tuberculosis since the antibody titers only slightly decreased even after chemotherapy for two years. 5) Two out of four nontuberculous mycobacteriosis cases showed high antibody titers 6) All three AIDS patients with tuberculosis showed low antibody titers. 7) The antibody was negative in almost all healthy controls showing a positive PPD skin test after vaccination with BCG, and it was therefore assumed that the antibody titer is not increased by BCG vaccination. 8) The antibody titers of the staff members working in the tuberculosis wards were not high compared with those of staff members working in the other wards.

AIDS-Related Opportunistic Infections↗

PubMed1995

Ebelactone B, an inhibitor of urinary carboxypeptidase Y-like kininase, prevents the development of deoxycorticosterone acetate-salt hypertension in rats.

Kininogen-deficient Brown Norway Katholiek rats (BN-Ka) excrete little urinary kinin, compared with normal rats of the same strain (BN Kitasato rats (BN-Ki)). Deoxycorticosterone acetate-salt treatment increased systolic blood pressure in both rats, but much faster in BN-Ka than in BN-Ki. Daily subcutaneous administration of ebelactone B (15 and 5 mg/kg/day), a rat urinary carboxypeptidase Y-like kininase inhibitor, significantly reduced systolic blood pressure in BN-Ki, but not in BN-Ka. This treatment significantly increased urinary Na+ excretion and reduced Na+ concentration in the erythrocytes in BN-Ki, but not in BN-Ka. An angiotensin-converting enzyme inhibitor, lisinopril (5 mg/kg/day s.c.), did not reduce the systolic blood pressure in either BN-Ki or BN-Ka. These results suggested that ebelactone B has promise as a preventive agent for the development of hypertension acting through the inhibition of urinary kinin degradation.

Angiotensin-Converting Enzyme Inhibitors↗