Biomedical subjects

Kouichi Hosokawa

Publications and source records attributed to Kouichi Hosokawa.

3 recordsLinked to original sources

PubMed2005

Systematic approach to cutoff frequency selection in continuous-wave electron paramagnetic resonance imaging.

This article describes a systematic method for determining the cutoff frequency of the low-pass window function that is used for deconvolution in two-dimensional continuous-wave electron paramagnetic resonance (EPR) imaging. An evaluation function for the criterion used to select the cutoff frequency is proposed, and is the product of the effective width of the point spread function for a localized point signal and the noise amplitude of a resultant EPR image. The present method was applied to EPR imaging for a phantom, and the result of cutoff frequency selection was compared with that based on a previously reported method for the same projection data set. The evaluation function has a global minimum point that gives the appropriate cutoff frequency. Images with reasonably good resolution and noise suppression can be obtained from projections with an automatically selected cutoff frequency based on the present method.

Algorithms↗

PubMed2005

[Survey of gemcitabine treatment for advanced pancreatic cancer in 20 hospitals of Nagano Prefecture].

To establish an effective therapy for pancreatic cancer, we made a retrospective survey of gemcitabine treatment performed at 20 hospitals in Nagano Prefecture. We analyzed data of 106 patients (64 men and 42 women, median age 66 years (33-83 years old)), half of whom had stage IV disease. Gemcitabine was administered for 3 consecutive weeks with one week rest in 57 patients, biweekly in 30 patients, initially for 3 weeks with 1 week rest and switched to biweekly schedule to 15 patients, and with another regimen to 4 patients. Analysis of the results of gemcitabine treatment between the 3 weeks with 1-week-rest regimen and the biweekly regimen revealed no differences between regimens in growth inhibition and symptom alleviation. However, we found less occurrence of blood toxicity in the biweekly regimen (40%) than in the 3 weeks with 1 week-rest regimen (59%). Median survival time for the biweekly regime was 9.7 months, only slightly longer than that of the 3 weeks with 1-week-rest regimen (8.5 months). The present study showed that a biweekly regimen for gemcitabine administration may be equivalent to the standard regime of 3 weeks with 1-week-rest regimen. Moreover, the biweekly regimen has advantages over the 3 weeks with 1-week rest regimen both economically and in terms of convenience for outpatient treatment. Therefore, the present results should be confirmed in future prospective studies, with the hope of developing a new standard treatment regimen for pancreatic cancer.

Adult↗

PubMed2002

A new technique for endoscopic mucosal resection with an insulated-tip electrosurgical knife improves the completeness of resection of intramucosal gastric neoplasms.

BACKGROUND: En bloc resection is optimal for the cure of gastric neoplasms by endoscopic mucosal resection (EMR). A new technique was developed for EMR by using an insulated-tip electrosurgical knife (IT-EMR). This is a report on the clinical application of IT-EMR. METHODS: IT-EMR of 123 gastric tumors was performed in 120 patients. The en bloc resection rate, completeness of resection, and associated complications were evaluated. The local recurrence rate was studied for 90 intramucosal lesions followed for more than 6 months without further treatment. RESULTS: The en bloc resection rate for all lesions was 54% (67/123 lesions). The en bloc resection rates were 82% (27/33) for lesions 10 mm or less in size, 54% (29/54) for those between 11 mm and 20 mm, and 31% (11/36) for those of over 20 mm. Complete resection rates in the cases with en bloc resection were 78% (21/27) for lesions 10 mm or less in size, 76% (22/29) for those between 11 mm and 20 mm, and 73% (8/11) for those over 20 mm. There were no episodes of major bleeding that required blood transfusion or surgical intervention; minor bleeding including oozing occurred in 38% (47/123). Perforation occurred in 1 case (1/123; 0.8%). The local recurrence rate for lesions resected en bloc was significantly lower than that for lesions resected as multiple fragments (respectively, 2/49; 4.1% vs. 7/41; 17%: p = 0.041). CONCLUSIONS: IT-EMR is feasible in clinical practice and has a high en bloc resection rate. En bloc resection may reduce the rate of local recurrence.

Adenoma↗