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Biomedical subjects

J Kamiya

Publications and source records attributed to J Kamiya.

At least 163 records · Page 9Linked to original sources
PubMed1976

Conflicting results in EEG alpha feedback studies: why amplitude integration should replace percent time.

Success or failure of EEG feedback training for alpha enhancement can depend on how alpha activity is quantified and fed back. Alpha-enhancement failures usually employ a percent time (%) technique; successes typically use amplitude integration (variation of). To dramatize the differences between percent and integration techniques, we derived both measures simultaneously from left occipital (O1) and left central (C3) sites for 16 male subjects who were given 5.6 hours of integrated alpha feedback from the midline occipital (Ozeta) site. At both the O1 and C3 sites the integrated and percent measures were not equivalent and not linearly related. Statistically significant differences in the (integrated, percent) correlation coefficients (z-transpormed) were observed under the different recording conditions: alpha enhancement, alpha suppression, and baselines. Theoretical discussion of integration and percent techniques is given and the adoption of amplitude integration measures and feedback stimuli is strongly advocated.

Action Potentials↗
PubMedDate not supplied

Doppler analysis of hepatic blood flow predicts liver dysfunction after major hepatectomy.

In 17 consecutive patients who underwent major hepatic resection, 9 of whom with combined resection of the gastrointestinal tract or the pancreatic head (or both), postoperative hepatic blood flow was investigated. In this study, the patients were classified into two groups according to their postoperative serum total bilirubin level: Group A comprised 7 patients with the level higher than 7 mg/dl for more than 1 week postoperatively, and group B comprised 10 patients who did not meet this criterion. For 2 weeks after surgery, the portal blood flow velocity, the hepatic artery resistive index (RI) calculated from the changes in Doppler frequency shifts, and the hepatic venous blood flow velocity were measured intermittently using color Doppler ultrasonography. Liver volume was assessed by computed tomography to provide the restoration. Significant differences in portal blood flow velocity and hepatic artery RI were noted between the two groups from the third postoperative day. In group A the portal blood flow velocity decreased below the preoperative value, and the hepatic artery RI increased above 0.75. In contrast, group B showed high portal blood flow velocity and low hepatic artery RI. In both groups the RI correlated significantly with the total bilirubin level (r = 0.74; p < 0.0001), and the growth rate of the remnant liver was proportional to the mean postoperative portal blood flow velocity (r = 0.70; p = 0.016). We concluded that measurement of the portal blood flow velocity and hepatic artery RI can be useful for predicting postoperative liver dysfunction and liver regeneration after major hepatic resection.

Adult↗
PubMedDate not supplied

Hepatic segmentectomy with caudate lobe resection for bile duct carcinoma of the hepatic hilus.

From 1979 through 1989, surgical resection was performed in 55 of 66 patients with carcinoma of the hepatic hilus after improving jaundice by percutaneous transhepatic biliary drainage (PTBD). Selective cholangiography through PTBD was done to define precisely the anatomical location--extent of the obstructing lesion in each segmental hepatic duct. Percutaneous transhepatic cholangioscopy was performed through the sinus tract of PTBD after replacing the drainage catheter with a 15 French catheter for superselective cholangiography and biopsy to make the definitive diagnosis of the histological extent of the tumor and any variation of each segmental hepatic duct that joins the hepatic hilus. In 46 (69.7%) of 66 patients, curative resection was possible. Forty-five of these underwent various types of hepatic segmentectomy with caudate lobectomy for a morbidity rate of 41.3% and an operative mortality rate of 6.4%. Fourteen (31.1%) advanced cases underwent combined resection of the portal vein together with hepatectomy. Microscopic tumor involvement in the caudate branches was confirmed in 44 of 45 patients who underwent caudate lobe resection. The 3-year survival rate for all 43 patients surviving the curative excision was 55.1% and the 5-year survival rate was 40.5%. All 11 patients who had an unresectable advanced tumor died within 9 months. Curative resection should be designed according to the preoperative findings of the extent of cancer in each segmental duct, and caudate lobe resection should be performed together with the smallest necessary hepatic segmentectomy possible.

Adenoma, Bile Duct↗
PubMedDate not supplied

Logistic regression and discriminant analyses of hepatic failure after liver resection for carcinoma of the biliary tract.

Stepwise logistic and discriminant analyses were used to define the risk factors for hepatic failure after liver resection for carcinoma of the biliary tract and to predict this complication. The logistic analysis identified the linear pattern of oral glucose tolerance test, cholangitis, pancreatoduodenectomy, and indocyanine green disappearance rate as the factors most related to hepatic failure among 18 pre- and perioperative parameters of the past 84 hepatectomized cases (55 hilar bile duct carcinomas and 29 gallbladder carcinomas). Our discriminant formula using five variables, including the above-mentioned four plus the liver resection rate, could distinguish the patients with posthepatectomy liver failure (n = 25) from those without (n = 59) with 86.9% accuracy, 96.0% sensitivity, and 83.1% specificity. The cross-validation test has confirmed that this model was robust for discriminant analysis. The results of this study show that statistical multifactorial analysis makes possible the preoperative prediction of hepatic failure after liver resection for carcinoma of the biliary tract.

Adult↗
PubMedDate not supplied

Clinicopathologic factors influencing survival of patients with bile duct carcinoma: multivariate statistical analysis.

To evaluate the influence of various clinicopathologic factors on survival, a computer analysis was performed on 70 patients who underwent resection for bile duct carcinoma. Univariate analysis of overall survival involving all the patients identified 10 factors that were associated with a significant outcome: location of primary lesion (p = 0.01), pancreatic invasion (p = 0.004), duodenal invasion (p = 0.005), macroscopic and microscopic vascular involvement (p = 0.009 and p = 0.04), perineural invasion (p = 0.02), lymphatic vessel involvement (p = 0.04), lymph node metastasis (p = 0.02), histologic type (p = 0.02), and depth of cancer invasion (p = 0.04). However, when the interactive effects of these factors were taken into account, the pancreatic invasion and perineural invasion were selected as the two most significant prognostic factors in a multivariate analysis using the Cox stepwise proportional hazards model. The age, sex, size of the tumor, macroscopic type of lesions, hepatic infiltration, serosal invasion, resected surgical margin at the proximal and distal ends, exposed surgical margin, peritoneal dissemination, and hepatic metastasis were not significantly associated with prognosis.

Adult↗