Biomedical subjects

Y Yasuda

Publications and source records attributed to Y Yasuda.

455 records · Page 26Linked to original sources

PubMedDate not supplied

Effects of cilostazol on the peripheral nerve function and structure in STZ-induced diabetic rats.

We examined the effect of cilostazol (CZ), antiplatelet agent and potent vasoactive compound, which has an inhibitory effect on tissue phosphodiesterase, on peripheral nerve in streptozotocin-induced diabetic rats. Diabetic rats were fed for 12 weeks with a chow containing 0.01% or 0.03% CZ (w/w) and the results were compared with untreated diabetic rats. The 0.03% CZ treatment significantly improved motor nerve-conduction velocity and restored nerve Na+, K(+)-ATPase activity in diabetic rats without affecting body weight and glycated hemoglobin levels, but the effects of 0.01% CZ treatment did not reach statistical difference. Elevated sorbitol and reduced myo-inositol levels in diabetic nerve tissues were not influenced by CZ treatment. Structural analysis of the sural nerve demonstrated a partial but significant effect on decreased mean myelinated fiber area and atrophic changes of the axon in diabetic rats treated with 0.01% CZ. CZ treatment inhibited reduction of pericyte area of endoneurial microvessels in diabetic rats. Expansion of endoneurial microvessels and luminal area in relation to vascular area also tended to be inhibited by CZ treatment. Thus CZ treatment ameliorated, although not completely, functional and structural abnormalities in peripheral nerve of diabetic rats without effecting the polyol pathway. These results support the contention that vascular factors may play an important role in the etiology of experimental diabetic neuropathy and suggest that CZ may have a beneficial therapeutic effect on diabetic neuropathy.

Animals↗

PubMedDate not supplied

Functional peptide-polyurethane conjugates with extended circulatory half-lives.

Peptides containing the RGD sequence were covalently attached to an isocyanate-containing polyurethane prepolymer and the biological properties of the complexes were evaluated. For the pentapeptide H2N-Tyr-Arg-Gly-Asp-Ser-OH (single-letter code, YRGDS), polymer conjugation lead to an increased half-life in the blood circulation of mice to > 10 h. The effect of covalent attachment of polymer on biological activity was examined in a related peptide, H2N-Gly-Arg-Gly-Asp-Ser-Pro-Ala-Cys- OH (GRGDSPAC). Inhibition of B16-F10 melanoma cell attachment and spreading on plates coated with fibronectin by an RGD-containing peptide and polymer-conjugated GRGDSPAC was observed to occur at similar concentrations. We conclude that the conjugation of peptides containing the Arg-Gly-Asp motif to this polymer resolves previous problems of their rapid loss from the circulation, while still allowing retention of full biological inhibitory activity.

Amino Acid Sequence↗

PubMedDate not supplied

Application of telomerase activity for screening of primary lung cancer in broncho-alveolar lavage fluid.

Telomerase is a ribonucleoprotein that synthesizes telomeric DNA onto chromosomal ends using an RNA component as a template. Extension of telomeric repeats by telomerase prevents telomere shortening with cell divisions and contributes to chromosomal stability, possibly leading to immortalization of the cells. In the present study, we used a telomerase assay to detect primary lung cancer in broncho-alveolar lavage fluid (BALF). A total of 58 BALF samples were examined by telometric repeat amplication protocol assay. Thirty-five (29 cancers, 2 salcoidoses, 2 pulmonary tuberculoses and 2 normal samples) of 58 (60.3%) cases were found to be positive for telomerase activity. The sensitivity of telomerase activity was 78.4%, compared with 64.7% of BALF cytology. Among 37 primary lung cancer patients diagnosed histopathologically, 24 had positive cytology and 29 had positive telomerase activity. The number increased to 32 patients when cytodiagnosis and telomerase activity were considered. Of patients in whom the presence of primary lung cancer was strongly suspected clinically, although there was no histopathological evidence, two were telomerase-positive, initially diagnosed as normal by cytological examination and histological examination but finally diagnosed as primary lung cancer (adenocarcinoma) in subsequent histological examination using operation specimens. These findings suggest that telomerase assay using BALF samples might be a useful screening method for primary lung cancer especially when combined with BALF cytology.

Aged↗

PubMedDate not supplied

Cytological diagnosis and telomerase activity of cells in effusions of body cavities.

Telomerase is a ribonucleoprotein that synthesizes telometric DNA on chromosome ends, and may be related to the aging and immortality of cells. Recently, a telometric repeat amplification protocol (TRAP) assay for telomerase activity, using the polymerase chain reaction, was developed. We examined the limitations of TRAP assay by applying it to a cultured colon cancer cell line (COLO320) and 58 human cytological materials from body cavity effusions, and obtained the following results; i) The limits of the TRAP assay were 20-50 cells for the COLO320 cell line; ii) One COLO320 cell per 100 normal blood white cells was detectable; iii) Seventeen of 58 samples were positive for telomerase activity in this study. The sensitivity was 69% (9/13) and the specificity was 87.5% (28/32) between cytological diagnosis and telomerase activity; iv) Among 29 malignant cases, 15 were positive for telomerase activity, while there were 11 cytologically positive cases. The positive cases detected by the combination of cytology and telomerase activity accounted for 21 of the total 29 cases (72.4%). These results suggest that the measurement of telomerase activity in body cavity effusions may be useful as an adjunctive tool for cytological and clinicopathological diagnosis and that this technique is potentially applicable to remnant cytological materials.

Ascites↗

PubMedDate not supplied

Automatic detection and measurement of EMG silent periods in masticatory muscles during chewing in man.

Silent periods are transient stops of muscle activity that are induced by mechanical or electrical stimulus. The current report describes a new algorithm which enables automatic detection and measurement of silent periods that occur in the EMG of human masticatory muscles during chewing efforts together with jaw positions in space at the occurrence of the silent periods. The EMG signal for detection of the silent period is modeled based on the observation of the EMG records induced from the jaw-closing muscles during chewing efforts in seven volunteer subjects. The algorithm for automatic detection and measurement of the EMG silent period has been applied successfully to real EMG data and the performance of the software was confirmed to be sufficiently reliable. The results of the analysis are stored in a biosignal database for possible clinical use.

Adult↗