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Biomedical subjects

Y Naito

Publications and source records attributed to Y Naito.

At least 127 records · Page 7Linked to original sources
PubMed2000

Regression of a presumed meningioma with the antiestrogen agent mepitiostane. Case report.

This 68-year-old woman underwent a distal gastrectomy for gastric cancer in August 1994. A presumed meningioma of the falx was found incidentally on a staging examination of the gastric cancer, but the meningioma was not treated with surgery. Instead, after gastrectomy the patient received tegafur as adjuvant chemotherapy until February 1996, when she was readmitted to the hospital because of loss of appetite and emaciation but with no recurrence of the gastric cancer. A computerized tomography scan obtained during this second admission showed no change in the meningioma. To improve her general condition, tegafur was discontinued and she was started on a course of the antiestrogen agent mepitiostane. Administration of mepitiostane for approximately 2 years resulted in a marked regression (73%) of the meningioma. This is the first reported case of a presumed meningioma that regressed as a result of use of the antiestrogen agent mepitiostane.

Adenocarcinoma, Papillary↗
PubMed2000

[Factors influencing satisfaction of cochlear implant users--a questionnaire-based study].

We surveyed on cochlear implant (CI) users using a questionnaire to determine how they use their CIs in daily life and to what degree they are satisfied with them. We also studied the relationship between the degree of satisfaction and speech perception score, age at operation, and deafness duration. Subjects were 37, postlingually-deafened adult CI users were subjected to this study. Average CI use per day was 13.6 hours. Some 60% of subjects understood person-to-person conversation without lipreading, but most could not communicate on the telephone, in meetings, or in noisy places, for example. Most--about 80%--were satisfied with CI, but 20% were not. Those not satisfied tended to be unable to understand person-to-person conversation even with CI and lipreading, indicating that understanding person-to-person conversation is one of the most important reasons for satisfaction in CI users. Speech recognition scores improved in all cases after implantation. Most patients with high speech recognition score-->40% in consonant recognition--were satisfied with CI, but those with recognition scores < 40% in consonant recognition, the degree of satisfaction varied. These results indicate that the degree of satisfaction in CI users does not always correspond to the degree of improvement in speech recognition score. Two patients not satisfied with CI had undergone surgery after the age of 65 years and deafness duration exceeding 20 years. Advanced age and a long deafness duration may thus reduce satisfaction with CIs.

Adult↗
PubMed2000

[Efficacy of docetaxel for recurrent breast cancer: evaluation based on chemosensitivity test and clinical response].

We investigated the chemosensitivity of anticancer agents against primary (230 patients, 268 tumors) and recurrent breast cancer (40 patients, 51 tumors) using histoculture drug response assays (HDRA) of surgical specimens. Of the 40 recurrent breast cancer patients, 26 were pretreated with anthracycline. The efficacy of the agents was assessed according to an inhibition index of optical density detected by an ELISA reader. The inhibition rate of docetaxel against recurrent tumors was similar that against primary ones, although the rates of adriamycin, 5 fluorouracil, mitomycin and cisplatin against recurrent tumors were significantly lower than those against primary ones. The clinical response of docetaxel was also evaluated in ten patients with recurrent breast cancer. Of the ten patients with recurrent breast cancer, eight were pretreated with anthracycline, and seven showed a partial response. These results indicate that docetaxel is effective against recurrent breast cancer, even anthracycline-resistant breast cancer.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Prospective study on alcohol intake and risk of subarachnoid hemorrhage among Japanese men and women.

BACKGROUND: Few prospective data are available to evaluate potential risk factors of subarachnoid hemorrhage among the Japanese, although several prospective studies conducted in the United States and in Europe have shown a positive relationship between alcohol intake and the risk of subarachnoid hemorrhage. METHODS: A 9.4 year follow-up study was conducted on 12,372 men and women age 40 to 69 years who had no history of stroke, in six communities in Japan. The incident cases of subarachnoid hemorrhage were confirmed with computed tomography findings and/or clinical findings. Alcohol intake and other cerebrovascular risk factors were measured at the baseline examination. A Cox proportional hazard analysis was used to estimate the relative risks and 95% confidence intervals of the incidence of subarachnoid hemorrhage. RESULTS: During the follow-up assessment, 71 cases of subarachnoid hemorrhages occurred. For men, heavy drinking appeared to be an independent risk factor for subarachnoid hemorrhage; multivariate-adjusted relative risk was 4.3 (95% confidence interval [CI]: 1.1-16.8; p = 0.04). Among women, no excess risk was found for heavy drinking, probably due to the small number of heavy drinkers (n = 15). The combination of heavy drinking with smoking or hypertension increased the risk of subarachnoid hemorrhage substantially for men; the multivariate-adjusted relative risk was 6.0 (95% CI: 1.8-20.1;p = 0.004) for heavy drinking smokers and 13.0 (95% CI: 3.9-43.9; p < 0.001) for heavy drinking hypertensives. CONCLUSIONS: A reduction in alcohol intake, smoking cessation, and control of hypertension are important in preventing subarachnoid hemorrhage among Japanese men.

Adult↗
PubMed2000

[Pain relief with alendronate therapy in a breast cancer patient with bone metastasis].

A 66-year-old woman developed a bone metastasis from breast cancer to the sternum in September, 1997. She received alendronate therapy, consisting of biweekly intravenous administrations of 10 mg-alendronate 6 times and monthly 20 mg-alendronate infusions 15 times. The first alendronate administration markedly alleviated her bone pain. She obtained complete pain relief after the 4th alendronate infusion. However, an elevation of tumor marker levels in serum without any pain increase forced us to treat her with medroxyprogesterone acetate and doxifluridine in addition to the alendronate therapy. With these therapies, she has shown an objective response (PR) of the bone metastasis for 8 months. In conclusion, alendronate therapy was effective against bone pain due to metastasis of breast cancer.

Aged↗
PubMed2000

[Histoculture drug response assay on non-small cell lung cancer].

We examined the chemosensitivity of non-small cell lung cancer (NSCLC) tissues to CDDP, 5-FU, ADM, MMC, ETP and SN38 using histoculture drug response assay (HDRA). One-hundred and thirty surgical specimens from NSCLC patients who were not given preoperative chemotherapy were used. The inhibition indexes of CDDP, 5-FU, MMC, ADM, ETP and SN38 were 39.1 +/- 18.2%, 48.0 +/- 19.7%, 63.3 +/- 17.7%, 47.6 +/- 22.0%, 36.9 +/- 21.1%, and 37.9 +/- 25.2%, respectively. Inhibition indexes were above the cutoff level, i.e., 'judged sensitive,' in 40 cases (31.3%) for CDDP, 34 cases (27.4%) for 5-FU, 54 cases (44.3%) for MMC, 36 cases (33.0%) for ADM, 29 cases (29.8%) for ETP, and 34 cases (37.4%) for SN38, respectively. In almost one-third of patients, the inhibition indexes of all drugs were under cutoff levels. Correlations between in vitro chemosensitivity data and patient responses to chemotherapy were obtained from 16 evaluable patients, and a 44.4% true positive rate and a 100% true negative rate were observed. Our results with HDRA for NSCLC showed a high incidence of intrinsic multidrug resistance. HDRA may help doctors to avoid non-effective chemotherapy for NSCLC patients.

Adenocarcinoma↗
PubMed2000

[Mini mid-line skin incision--a more cosmetic challenge for surgery of funnel chest: report of a case].

We performed a operation using a mini mid-line skin incision for ten-year-old male with funnel chest. The skin incision was made from the level of nipple to the lower end of the xiphoid process. He had sternal elevation as corrective surgery. There was no complication and he discharged at 11th day after surgery. We believe our method is more appropriate in fulfilling the cosmetic needs for the patient of funnel chest.

Child↗
PubMed2000

[Evaluation by FDG-PET of arterial infusion chemotherapy for unresectable metastatic liver tumor].

We evaluated arterial infusion chemotherapy for unresectable metastatic liver tumor using FDG-PET and CT. A 72-year-old female patient with multiple metastatic liver tumors of rectal cancer was treated by arterial infusion chemotherapy. The tumor size decreased by chemotherapy, but there was a high uptake lesion of FDG. Three months later, tumor ingrowth was detected. FDG produces images of regional glycolytic activity, and it is a useful method of assessment of tumor viability after chemotherapy in patients with cancer.

Aged↗
PubMed2000

Malfunction of a Hancock bioprosthesis in the mitral position 24 years after initial implantation.

BACKGROUND AND AIMS OF THE STUDY: Although many types of cardiac bioprosthetic valves are currently available, the major disadvantage of their use is limited durability due to progressive structural valve deterioration. Few such valves function beyond 20 years. METHODS: A 61-year-old man was admitted urgently to our institute with acute mitral insufficiency, 24 years after undergoing mitral valve replacement with a 25-mm standard Hancock porcine bioprosthesis for mitral stenosis. RESULTS: Mitral valve reoperation was performed successfully with a mechanical valve. The explanted bioprosthesis showed leaflet perforations and a commissural tear, moderate calcification on the commissures, and pannus overgrowth. CONCLUSION: The findings in this case suggest that individual patient variables, as well as the design and the construction of the valve are major determining factors in the rate of valve failure.

Bioprosthesis↗
PubMed1999

Syntheses and evaluation of amidinobenzofuran derivatives as tryptase inhibitors.

We report the syntheses and evaluation of amidinobenzofuran derivatives as tryptase inhibitors. Among the compounds we evaluated, 1,5-Bis[4-(5-amidinobenzofuran-2-ylcarbonyl)piperazinylca rbonylmethoxy]cyclooctane 26 (AY0068) was found to be a selective and potent non-peptide inhibitor. 26 was effective in PCA reaction in rats without showing antihistaminic activity.

Animals↗
PubMed1999

Observation of hydrogen-deuterium exchange of ubiquitin by direct analysis of electrospray capillary-skimmer dissociation with Fourier transform ion cyclotron resonance mass spectrometry.

The structure of ubiquitin, a small cytoplasmic protein with an extended beta-sheet and an alpha-helix surrounding a hydrophobic core, has been characterized by hydrogen-deuterium (H/D) exchange labeling in conjunction with successive analysis by capillary-skimmer dissociation with electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS). The deuterium content of each fragment ion was investigated at different times, and the results indicate that the deuterium incorporation rate into the backbone amides of ubiquitin varied depending on the environment of the amide hydrogens. Amide hydrogens of the N-terminal beta-strand showed quite slow exchange while those of the 35-39 loop were exchanged within a short exposure time to deuterium oxide. It was also possible to evaluate the difference in hydrogen-bond stability. The present data are consistent with the structural features obtained by X-Ray and NMR analyses. Although some of the labeling information might be lost by the scrambling of amide protons during capillary-skimmer dissociation, the results demonstrate that the present method provides useful higher-order structural information for proteins.

Animals↗
PubMed1999

Regulation of neuronal nitric-oxide synthase by calmodulin kinases.

Phosphorylation of neuronal nitric-oxide synthase (nNOS) by Ca2+/calmodulin (CaM)-dependent protein kinases (CaM kinases) including CaM kinase Ialpha (CaM-K Ialpha), CaM kinase IIalpha (CaM-K IIalpha), and CaM kinase IV (CaM-K IV), was studied. It was found that purified recombinant nNOS was phosphorylated by CaM-K Ialpha, CaM-K IIalpha, and CaM-K IV at Ser847 in vitro. Replacement of Ser847 with Ala (S847A) prevented phosphorylation by CaM kinases. Phosphorylated recombinant wild-type nNOS at Ser847 (approximately 0.5 mol of phosphate incorporation into nNOS) exhibited a 30% decrease of Vmax with little change of both the Km for L-arginine and Kact for CaM relative to unphosphorylated enzyme. The activity of mutant S847D was decreased to a level 50-60% as much as the wild-type enzyme. The decreased NOS enzyme activity of phosphorylated nNOS at Ser847 and mutant S847D was partially due to suppression of CaM binding, but not to impairment of dimer formation which is thought to be essential for enzyme activation. Inactive nNOS lacking CaM-binding ability was generated by mutation of Lys732-Lys-Leu to Asp732-Asp-Glu (Watanabe, Y., Hu, Y., and Hidaka, H. (1997) FEBS Lett. 403, 75-78). It was phosphorylated by CaM kinases, as was the wild-type enzyme, indicating that CaM-nNOS binding was not required for the phosphorylation reaction. We developed antibody NP847, which specifically recognize nNOS in its phosphorylated state at Ser847. Using the antibody NP847, we obtained evidence that nNOS is phosphorylated at Ser847 in rat brain. Thus, our results suggest that CaM kinase-induced phosphorylation of nNOS at Ser847 alters the activity control of this enzyme.

Amino Acid Sequence↗
PubMed1999

C-terminal amino acid residues are required for the folding and cholesterol binding property of perfringolysin O, a pore-forming cytolysin.

Perfringolysin O (theta-toxin) is a pore-forming cytolysin whose activity is triggered by binding to cholesterol in the plasma membrane. The cholesterol binding activity is predominantly localized in the beta-sheet-rich C-terminal half. In order to determine the roles of the C-terminal amino acids in theta-toxin conformation and activity, mutants were constructed by truncation of the C terminus. While the mutant with a two-amino acid C-terminal truncation retains full activity and has similar structural features to native theta-toxin, truncation of three amino acids causes a 40% decrease in hemolytic activity due to the reduction in cholesterol binding activity with a slight change in its higher order structure. Furthermore, both mutants were found to be poor at in vitro refolding after denaturation in 6 M guanidine hydrochloride, resulting in a dramatic reduction in cholesterol binding and hemolytic activities. These activity losses were accompanied by a slight decrease in beta-sheet content. A mutant toxin with a five-amino acid truncation expressed in Escherichia coli is recovered as a further truncated form lacking the C-terminal 21 amino residues. The product retains neither cholesterol binding nor hemolytic activities and shows a highly disordered structure as detected by alterations in the circular dichroism and tryptophan fluorescence spectra. These results show that the C-terminal region of theta-toxin has two distinct roles; the last 21 amino acids are involved to maintain an ordered overall structure, and in addition, the last two amino acids at the C-terminal end are needed for protein folding in vitro, in order to produce the necessary conformation for optimal cholesterol binding and hemolytic activities.

Amino Acid Sequence↗