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Biomedical subjects

Y Kiryu

Publications and source records attributed to Y Kiryu.

At least 19 recordsLinked to original sources
PubMed2004

Infection experiments with Aphanomyces invadans in four species of estuarine fish.

Along the eastern seaboard of the US, Atlantic menhaden, Brevoortia tyrannus, develop characteristic ulcerative lesions, a condition termed ulcerative mycosis. These lesions are identical to those seen across Asia in fish affected by epizootic ulcerative syndrome, a condition caused by the fungus-like oomycete Aphanomyces invadans. Young-of-the-year menhaden inhabiting estuarine environments are the primary species affected in the USA and little is known about the factors involved in the initiation of the lesions, or why menhaden are predominantly infected. Atlantic menhaden, hogchoker, Trinectus maculatus, striped killifish, Fundulus majalis, and mummichog, Fundulus heteroclitus, were inoculated with A. invadans (80 zoospores per fish) to explore species differences in infection and lesion development. All four species developed lesions. Killifish developed frank lesions similar to those observed in menhaden but the gross lesions occurred later, approximately 5-10 days after those on menhaden. Hogchoker and mummichog did not develop gross skin ulcers; rather, their lesions appeared as reddened areas under the epidermis. Mummichogs also showed evidence of significant healing with a well-developed granuloma and significant myocyte regeneration. These experiments show that species barriers as well as ecological barriers can explain some of the factors involved in the development of lesions in, and specificity of the water mould for, menhaden.

Animals↗
PubMed2004

Identification of AFLP makers linked to non-seed shattering locus (sht1) in buckwheat and conversion to STS markers for marker-assisted selection.

Shattering habit in buckwheat has two forms: brittle pedicel and weak pedicel. Brittle pedicel is observed in wild buckwheat, but not in cultivated buckwheat. Brittle pedicel in buckwheat is produced by two complementary, dominant genes, Sht1 and Sht2. The sht1 locus is linked to the S locus; almost all common buckwheat cultivars possess the allele sht1. To detect molecular makers linked to the sht1 locus, we used amplified fragment-length polymorphism (AFLP) analysis in combination with bulked segregant analysis of segregating progeny of a cross between a non-brittle common buckwheat and a brittle self-compatible buckwheat line. We screened 312 primer combinations and constructed a linkage map around the sht1 locus by using 102 F2 plants. Five AFLP markers were linked to the sht1 locus. Two of these, e54m58/610 and e55m46/320, cosegregated with the sht1 locus without recombination. The two AFLP markers were converted to STS markers according to the sequence of the AFLPs. The STS markers are useful for marker-assisted selection of non-brittle pedicel plants and provides a stepping-stone for map-based cloning and characterization of the gene encoding non-brittle pedicel.

Base Sequence↗
PubMed2000

Anti-cancer activities of pyrazolo[1,5-a]indole derivatives.

The structure activity relationship (SAR) in the anti-cancer activities of pyrazolo[1,5-a]indole derivatives was investigated, and the following conclusions were obtained: 1) N(1)-quaternarization is essential for anti-cancer activity, 2) the size and polarity of the 2-substituent is crucial for in vitro activity which allows further investigation in an in vivo test, 3) the effect of the 4-substituent on the activity is minor compared with the other two factors.

Antineoplastic Agents↗
PubMed1999

Chicoric acid analogues as HIV-1 integrase inhibitors.

The present study was undertaken to examine structural features of L-chicoric acid (3) which are important for potency against purified HIV-1 integrase and for reported cytoprotective effects in cell-based systems. Through a progressive series of analogues, it was shown that enantiomeric D-chicoric acid (4) retains inhibitory potency against purified integrase equal to its L-counterpart and further that removal of either one or both carboxylic functionalities results in essentially no loss of inhibitory potency. Additionally, while two caffeoyl moieties are required, attachment of caffeoyl groups to the central linking structure can be achieved via amide or mixed amide/ester linkages. More remarkable is the finding that blockage of the catechol functionality through conversion to tetraacetate esters results in almost no loss of potency, contingent on the presence of at least one carboxyl group on the central linker. Taken as a whole, the work has resulted in the identification of new integrase inhibitors which may be regarded as bis-caffeoyl derivatives of glycidic acid and amino acids such as serine and beta-aminoalanine. The present study also examined the reported ability of chicoric acid to exert cytoprotective effects in HIV-infected cells. It was demonstrated in target and cell-based assays that the chicoric acids do not significantly inhibit other targets associated with HIV-1 replication, including reverse transcription, protease function, NCp7 zinc finger function, or replication of virus from latently infected cells. In CEM cells, for both the parent chicoric acid and selected analogues, antiviral activity was observable under specific assay conditions and with high dependence on the multiplicity of viral infection. However, against HIV-1- and HIV-2-infected MT-4 cells, the chicoric acids and their tetraacetylated esters exhibited antiviral activity (50% effective concentration (EC50) ranging from 1.7 to 20 microM and 50% inhibitory concentration (IC50) ranging from 40 to 60 microM).

Animals↗
PubMed1997

Case report: haemorrhagic colitis associated with royal jelly intake.

The case report of a 53-year-old woman with abdominal pain and bloody diarrhoea is described. Prior to the onset of symptoms the patient had taken royal jelly for 25 days. Colonoscopy revealed that the mucosa was haemorrhagic and oedematous throughout the 20 cm long sigmoid colon. Histopathologically, mucosal haemorrhage, oedema, and infiltration of inflammatory cells were observed. Transmission electron microscopic examination revealed platelet aggregation in 30% of capillaries in the mucosal lesions. The drug-induced lymphocyte stimulation test was slightly positive for royal jelly (847 c.p.m., SI = 147%) compared with the control (576 c.p.m.). The patient's signs and symptoms disappeared within a few days after the initiation of conservative therapy, and the colonic lesions disappeared after 2 weeks of this therapy. This is the first reported case of haemorrhagic colitis associated with royal jelly intake.

Colitis↗
PubMed1996

Results of radiation therapy for hypopharyngeal carcinoma: impact of accelerated hyperfractionation on prognosis.

We reviewed the results of treatment in 52 patients with hypopharyngeal carcinoma who underwent radical radiation therapy using a two-fractionation scheme--conventional fractionation (CF) and accelerated hyperfractionation (AHF)--in order to evaluate the impact of the fractionation scheme on prognosis. The 5-year survival rate for the 52 patients was 19.5%, and a significantly better rate was obtained with AHF (44.4%) than with CF (12.4%). Of 27 patients who showed a complete response (CR), a higher CR rate (61%) was achieved with AHF than with CF (47%). A similar trend was also observed for T3 and T4 tumors (55% with AHF vs. 36% with CF). Multivariate analysis demonstrated that neck node status was a significant factor related to local control, and that local response and the fractionation scheme employed were significant prognostic factors for survival. The recurrence rate and recurrence within the radiation field in the AHF group was lower than in the CF group (27% vs. 50%), although the time to recurrence in the two groups did not differ greatly. Voice preservation was achieved in 20% of the patients. Considering the better survival and local control rate compared with conventional fractionation, accelerated hyperfractionation seems a preferable treatment for hypopharyngeal carcinoma.

Adult↗
PubMed1996

Microvascular disturbances in the colonic mucosa in antibiotic-associated haemorrhagic colitis: involvement of platelet aggregation.

An ultrastructural study of the colonic mucosa was performed in four patients with antibiotic-associated haemorrhagic colitis and new findings are reported. Colonoscopy was performed and biopsy specimens were obtained within 24 h of the onset of bloody diarrhoea. Colonoscopy demonstrated diffuse oedematous and haemorrhagic mucosa with erosions and white coat. Light microscopy revealed mucosal haemorrhage and inflammatory cell infiltration. Ultrastructurally, platelet aggregation was frequently present in the lumina of colonic mucosal capillaries, causing engorgement of red blood cells in adjacent microvessels. Mild to severe damage was observed in capillary endothelial cells, including discontinuity of basement membranes, gaps between endothelial cells and the destruction of capillaries. There was no evidence of microvascular spasm. In conclusion, our findings suggest that antibiotics directly or indirectly cause microcirculatory disturbances, which result in tissue damage and haemorrhage, in the colonic mucosa.

Adult↗
PubMed1994

[Two cases of rheumatoid arthritis presenting autoimmune hepatic diseases].

We report on two cases of rheumatoid arthritis (RA) presenting autoimmune hepatic diseases. The first patient, who had been diagnosed as RA at the age of 63, was hospitalized in order to undergo surgery for total left knee replacement at the age of 69. She acquired acute serum hepatitis as a result of blood transfusion she received during the operation. Five years later, she visited our clinic suffering from polyarthritis. She was found to have hyper-alkaline phosphatase (ALP) and hyper rGTP, but no AMA. The second patient, a 60-year-old female whose onset of RA was at the age of 45, complained of general fatigue, and was admitted to the hospital because of persistent liver dysfunction. When corticosteroid was administered to these patients, ALP and rGTP levels in the first case, and AST and ALT levels in the second case were reduced to values in the normal range. ANA in the first case continued to register negative, but ANA in the second case became positive after the patient developed acute hepatitis. Both patients were found to have anti-p25 triplet liver/kidney microsome antibody. We discuss the clinical significance of this antibody.

Aged↗
PubMed1994

Prognostic factors of poorly-differentiated squamous cell carcinoma of the nasopharynx.

Retrospective analysis was performed with intent to evaluate prognostic factors in radiation therapy for 72 patients with histologically confirmed poorly-differentiated squamous cell carcinoma of the nasopharynx. The 10-year overall actuarial and cause specific survival rates were 36 and 40%, respectively. The median survival time was 43 months. Sixteen patients survived for more than 10 years (maximum 297 months). The five- and 10-year cause specific survival rates for Stages I, II, III and IV disease were 100 and 100%, 80 and 27%, 83 and 83%, and 38 and 31%, respectively. Two patients with Stage II disease died of a re-recurrent tumor more than seven years after their initial treatment. There was a significant difference between the survival curve for Stage I or III disease and that for Stage IV disease (P < 0.05). The patients with a T1-3 tumor had a statistically better survival rate than those with a T4 tumor (T1:T4, P < 0.001, T2 or T3:T4, P < 0.05). The patients with N0 had statistically better survival rates than those with N3 (P < 0.01). Twenty-eight patients developed loco-regional recurrence. Twenty-one patients developed distant bone metastases, most of which occurred within a year of the initiation of radiation therapy. The survival for the patients with loco-regional recurrence was nearly the same as that for the patients without loco-regional recurrence. The 10-year survival rates for patients with and without distant bone metastases were 0 and 48%, respectively (P < 0.001). Multivariate analysis revealed that the parameters influencing cause specific survival were stage categories of T and N, and adjuvant chemotherapy, whereas those influencing loco-regional recurrence were only stage categories of T and N. The only parameter to influence distant bone metastases was sex. We concluded the most important cause of failure for the patients with poorly-differentiated squamous cell carcinoma of the nasopharynx to be distant bone metastases.

Adolescent↗