Biomedical subjects

T Yagyu

Publications and source records attributed to T Yagyu.

At least 19 recordsLinked to original sources

PubMed1998

Global, regional, and local measures of complexity of multichannel electroencephalography in acute, neuroleptic-naive, first-break schizophrenics.

BACKGROUND: Schizophrenic symptoms commonly are felt to indicate a loosened coordination, i.e. a decreased connectivity of brain processes. METHODS: To address this hypothesis directly, global and regional multichannel electroencephalographic (EEG) complexities (omega complexity and dimensional complexity) and single channel EEG dimensional complexities were calculated from 19-channel EEG data from 9 neuroleptic-naive, first-break, acute schizophrenics and 9 age- and sex-matched controls. Twenty artifact-free 2 second EEG epochs during resting with closed eyes were analyzed (2-30 Hz bandpass, average reference for global and regional complexities, local EEG gradient time series for single channels). RESULTS: Anterior regional Omega-Complexity was significantly increased in schizophrenics compared with controls (p < 0.001) and anterior regional Dimensional Complexity showed a trend for increase. Single channel Dimensional Complexity of local gradient waveshapes was prominently increased in the schizophrenics at the right precentral location (p = 0.003). CONCLUSIONS: The results indicate a loosened cooperativity or coordination (vice versa: an increased independence) of the active brain processes in the anterior brain regions of the schizophrenics.

Acute Disease↗

PubMed1998

Smell and taste of chewing gum affect frequency domain EEG source localizations.

We investigated brain electric field signatures of subjective feelings after chewing regular gum or gum base without flavor. 19-channel eyes-closed EEG from 20 healthy males before and after 5 minutes of chewing the two gum types in random sequence was source modeled in the frequency domain using the FFT-Dipole-Approximation. 3-dimensional brain locations and strengths (Global Field Power, GFP) of the equivalent sources of five frequency bands were computed as changes from pre-chewing baseline. Gum types differed (ANOVA) in pre-post changes of source locations for the alpha-2 band (to anterior and right after regular gum, opposite after gum base) and beta-2 band (to anterior and inferior after regular gum, opposite after gum base), and of GFP for delta-theta, alpha-2 and beta-1 (regular gum: increase. gum base: decrease). Subjective feeling changed to more positive values after regular gum than gum base (ANOVA).--Thus, chewing gum with and without taste-smell activates different brain neuronal populations.

Adult↗

PubMed1997

Multichannel EEG fields during and without visual input: frequency domain model source locations and dimensional complexities.

27-Channel EEG potential map series were recorded from 12 normals with closed and open eyes. Intracerebral dipole model source locations in the frequency domain were computed. Eye opening (visual input) caused centralization (convergence and elevation) of the source locations of the seven frequency bands, indicative of generalized activity; especially, there was clear anteriorization of alpha-2 (10.5-12 Hz) and beta-2 (18.5-21 Hz) sources (alpha-2 also to the left). Complexity of the map series' trajectories in state space (assessed by Global Dimensional Complexity and Global OMEGA Complexity) increased significantly with eye opening, indicative of more independent, parallel, active processes. Contrary to PET and fMRI, these results suggest that brain activity is more distributed and independent during visual input than after eye closing (when it is more localized and more posterior).

Adult↗

PubMed1997

A detailed analysis of the role of K-ras gene mutation in the progression of colorectal adenoma.

To elucidate the role of ras gene mutations during the early stage of colorectal tumour progression, K-ras gene mutations were analysed in 32 benign adenomas and 36 adenomas with focal carcinoma in the colorectum by microscraping of histologically pure regions from tissue sections, polymerase chain reaction-restriction fragment length polymorphism and in part by direct sequencing. Several regions were scraped out and analysed when an adenoma contained areas with different grades of dysplasia. The frequencies of K-ras gene mutation in mild dysplasia, moderate dysplasia and focal carcinoma were 19% (7/36), 51% (25/49) and 39% (14/36) respectively. The K-ras gene status was heterogeneous in 4 of the 11 benign adenomas from which multiple samples were obtained, and mutations were always found in the regions with more advanced dysplasia in these adenomas. Thirteen of the 36 adenomas with focal carcinoma showed heterogeneity of mutations between the adenoma region and the focal carcinoma. Seven of which had mutations only in the adenoma region. These findings indicated that the K-ras gene mutations occur during the late stage of adenoma progression and may confer a more advanced morphological phenotype of adenoma, but these mutations are not mainly involved in malignant transformation from adenoma to carcinoma.

Adenoma↗

PubMed1997

Chewing-gum flavor affects measures of global complexity of multichannel EEG.

Global complexity of spontaneous brain electric activity was studied before and after chewing gum without flavor and with 2 different flavors. One-minute, 19-channel, eyes-closed electroencephalograms (EEG) were recorded from 20 healthy males before and after using 3 types of chewing gum: regular gum containing sugar and aromatic additives, gum containing 200 mg theanine (a constituent of Japanese green tea), and gum base (no sugar, no aromatic additives); each was chewed for 5 min in randomized sequence. Brain electric activity was assessed through Global Omega (Omega)-Complexity and Global Dimensional Complexity (GDC), quantitative measures of complexity of the trajectory of EEG map series in state space; their differences from pre-chewing data were compared across gum-chewing conditions. Friedman Anova (p < 0.043) showed that effects on Omega-Complexity differed significantly between conditions and differences were maximal between gum base and theanine gum. No differences were found using GDC. Global Omega-Complexity appears to be a sensitive measure for subtle, central effects of chewing gum with and without flavor.

Adult↗

PubMed1997

[A new two-part therapy for multiple bilobar liver metastases of colorectal cancer--treatment of one lobe with partial hepatectomy and the other with arterial chemotherapy].

We studied a new two-part therapy for patients of multiple (more than five) bilobar liver metastases from colorectal cancer, in which one lobe is treated with partial hepatectomy and the other with arterial chemotherapy. The patient was a 72-year-old woman who had undergone sigmoidectomy and partial hepatectomy on March 9, 1995, for advanced sigmoid cancer with liver metastasis. In December 1995, new foci were detected in the remaining liver. Intraoperative echography during reoperation revealed 6 foci in the right lobe, 2 in the left lobe and 1 in the caudate lobe. During reoperation, we performed partial hepatectomy at the left lobe metastases and microwave coagulation in the caudate lobe. A catheter was inserted into the right hepatic artery, and the right hepatic artery was ligated with the catheter. From 2 weeks after operation, CDDP (20 mg) and 5-FU (1,500 mg) were given weekly by infusion from the arterial root. As a result, the serum CEA level fell to 3.6 ng/ml on June 26, 1996, and 1.9 mg/ml on August 14, 1996. A right lobectomy would have been performed if no metastasis appeared in the remainder of the left lobe over a one-year period. However, no foci were detected on a CT scan on March 26, 1997. This new two-part therapy warrants detailed investigation for bilobar bilateral liver metastases of colorectal cancer.

Aged↗

PubMed1997

[Fluorine-18 labeled 6-fluoro-L-dopa: systematization and evaluation of its usefulness].

6-[18F]Fluoro-L-dopa (L-3,4-dihydroxy-6-[18F]fluorophenylalanine; 6-[18F]FDPA) is useful to assess presynaptic dopamine metabolism in central nervous system. In this paper, we report on the usefulness of the 6-[18F]FDOPA synthesis system developed for the routine synthesis. This system consists of the 6-[18F]FOPA synthesis and the separation units in conjunction with controller using a personal computer. The synthesis time of 6-[18F]FDOPA was 73 minutes. The typical yield and specific activity were 1.4-2.4 GBq and 244-270 MBq/mumol at the end of synthesis, respectively, under the irradiation condition of 50 microA for 130 minutes. The radiochemical yields of 6-[18F]FDOPA were 31.3-38.7% based on the [18F]acetylhypofluorite, and the results were affected with the condition of potassium acetate (AcOK) to produce gaseous [18F]acetylhypofluorite. This system is useful for the routine production of 6-[18F]FDOPA because of its high yield and high specific activity while maintaining AcOK in good condition, and decreasing the radiation exposure for chemist.

Brain↗

PubMed1996

Expression of truncated midkine in human colorectal cancers.

Midkine (MK) is a growth differentiation factor originally found as the product of a retinoic acid-responsive gene. The expression of MK was examined in 35 surgically resected specimens of primary colorectal cancer using the reverse transcription-polymerase chain reaction (RT-PCR). All of the cancerous tissues expressed MK. In 5/25 cancerous tissues a truncated form of MK, which was recently found in various human tumor cell lines, was detected in addition to the full-size MK. In contrast, the truncated from of MK could not be detected in non-cancerous tissues, whereas the wild-type form was detected in 8/10 non-cancerous tissues. These results suggest that the expression of the truncated form of MK may be associated with tumorigenesis.

Carrier Proteins↗

PubMed1996

Echo-Doppler evaluation of reverse flow sign in the intrahepatic portal branches after surgery.

OBJECTIVE: The author's evaluated the clinical significance of the development of reversed portal flow after abdominal surgery other than portosystemic shunt procedure. SUMMARY BACKGROUND DATA: There have been several reports in regard to reversed portal flow demonstrated by pulsed Doppler ultrasonography, most of which were related to portal hypertension. To the authors' knowledge, this is the first report in which reversed portal flow also is present in patients who have undergone abdominal surgery other than portosystemic shunt procedure. METHODS: Preoperative and postoperative pulsed Doppler ultrasonographic examinations were performed in 126 patients who underwent abdominal surgery. Postoperatively, the portal flow direction was assessed in the right portal branch or the umbilical portion of the left portal branch. RESULTS: Of the 126 patients, reversed portal flow developed in 10 after surgery; 9 of them died of liver failure. CONCLUSIONS: The postoperative development of reversed portal flow is considered to have grave prognostic significance, indicating that the degree of postoperative liver damage is extremely critical.

Adult↗

PubMed1996

[Combination of intra-hepatic arterial infusion of low-dose cisplatin and oral administration of high-dose doxyfluridine for patients with liver metastases of gastric cancer].

Three cases of gastric cancer with multiple liver metastases were treated with low-dose CDDP and high-dose 5'-DFUR after surgery. The regimen was 20 mg CDDP intra-hepatic arterial infusion per week and 1,200 mg 5'-DFUR oral treatment per day. The liver metastases of two cases responded to this chemotherapy with a reduction of more than 90%, and two cases lived more than 2 years. All of them lived more than one year. This therapy had few side effects and was performed ambulatorily once per week, so patients were able to maintain their quality of life. This combination therapy may well assure a better prognosis for patients with liver metastases of gastric cancer.

Administration, Oral↗

PubMed1996

Strategy for breast conserving treatment--analysis of recurrence and prognosis after breast cosnserving treatment.

Two hundred and four patients with small breast cancer (T < or = 3.0 cm. N0 or N1a) were given breast conserving treatment (radiation group: 101, non-radiation group: 103) during the period from Feb. 1988 to Jan. 1995. Survival analysis of breast conserving treatment radiation group versus non-radiation group revealed the following: 1) Breast conserving treatment had a good prognosis, and a 5-year overall survival rate of 96.2%. 2) There was no significant difference of 5-year overall, disease-free and ipsilateral breast disease-free survival rate between the radiation group and non-radiation group. 3) Surgical margin involvement was the most significant risk factor in local recurrence after breast conserving treatment, and non-radiation was a possible risk factor. 4) Local recurrence was a significant risk factor for distant metastases after breast conserving treatment the same as node positive. These results suggested as follows: 1) Lumpectomy with a clear margin and radiation is the best choice for small breast cancer (T < or = 3.0 cm, N0 or N1a). 2) Adjuvant therapy after surgical treatment is necessary for local recurrence.

Axilla↗

PubMed1996

[Evaluation of prophylactic hepatic arterial infusion chemotherapy after hepatectomy for metastases from colorectal cancer--the second report].

We followed 18 patients who underwent curative hepatectomy for metastatic carcinoma of the colon from March 1993 to March 1995, and investigated their survival and the effect of treatment on recurrence. The patients were randomly divided into two groups. Group A (n = 9) was given continuous 5-FU (500 mg x 4 days/week) for six weeks from 2 weeks after surgery via the hepatic artery and Group B (n = 9) was given 5-FU orally from 2 weeks after surgery. The cumulative one-, two-, and three-year survival was 88.9, 88.9, and 76.2% in Group A, while the one- and two-year survival was 100 and 80% in Group B. The one-, two-, and three-year disease-free survival was 77.8% in Group A, while the one- and two-year disease-free survival was 55.6 and 29.6% in Group B (p = 0.0369: Mantel-Cox). These findings suggest that continuous hepatic artery infusion of 5-FU is effective against post-hepatectomy recurrence of metastatic carcinoma of the colon.

Colorectal Neoplasms↗

PubMed1995

Microstate segmentation of spontaneous multichannel EEG map series under diazepam and sulpiride.

Spontaneous multichannel brain electric field (EEG) map series of 20 seconds duration at 1, 15, 30, 45, and 60 minutes after the injection of a single dose of diazepam (13 ss) or sulpiride (6 ss) were segmented into microstates of quasi-constant landscape but varying durations. Post-minus-preinjection difference values were computed for the six microstate variables: specific window size, duration, orientation, distance between windows, and location of center of gravity on the anterior-posterior and left-right axis. Differences between drugs were explored with ANOVAs. Microstate duration increased after sulpiride, and the location of the microstate center of gravity on the anterior-posterior axis moved to a more anterior position after diazepam. The results are in agreement with expectations based on measurements of patients' EEG microstates and with results using estimates of EEG model source locations in the frequency domain. Microstate segmentation appears to be a useful method for physiologically meaningful reduction of multichannel brain electric field data in psychopharmacology.

Adult↗

PubMed1995

[Evaluation of prophylactic hepatic arterial infusion chemotherapy after hepatectomy for metastases from colorectal cancer].

The significance of continuous hepatic arterial infusion (HAI) chemotherapy of 5-FU to prevent recurrence in the remnant liver following curative hepatectomy for colorectal metastases was analyzed in the prospective randomized study. Patients of HAI chemotherapy group received 6 weeks of 5-FU 500 mg/day. The one- and two-year overall survival rates of nine patients with HAI therapy were 87.5% and 87.5%, respectively, while the rates of ten cases without the regional chemotherapy were 100% and 66.7%, respectively, indicating no obvious difference. On the other hand, the disease-free survival rates of HAI Group were higher than those of control group. The disease-free survival rates of the former were 75.0% at one-year and 75.0% at two-year, and the rates of the latter were 47.6% and 47.6%, respectively. No serious complications such as severe liver dysfunction, sclerotic cholangitis or hepatic necrosis were observed. Although the follow-up period was not enough long to accurately evaluate the efficacy, local prophylactic chemotherapy by continuous infusion of 5-FU could be a promising method as an adjuvant chemotherapy after hepatic resection for colorectal metastases.

Aged↗

PubMed1995

[A case of multiple liver metastasis from ileac carcinoid effectively treated with continuous intraarterial infusion of somatostatin analog].

We report a case of multiple liver metastasis from ileac carcinoid treated with continuous intraarterial infusion of somatostatin analog. A 65-year-old man who complained of chest pain was admitted to Yamaguchi University Hospital School of Medicine for further examination of cardiac angina. Liver tumors, which were detected during ECHO cardiogram examination, were diagnosed as metastasis from carcinoid by percutaneous transhepatic liver biopsy. Primary tumor was found at the ileum by colonofiberscopy. We performed ileo-cecal resection and catheterization from the gastroduodenal artery for intraarterial chemotherapy under laparotomy. After the operation, the patient was treated with continuous intraarterial infusion of somatostatin analog (100 micrograms/day, 5 days/week for 16 weeks). The tumor in segment 6 (S6) disappeared, but the tumor in S2 enlarged after the therapy. Hepatic angiography confirming the drug distribution demonstrated the occlusion of the left hepatic artery. This drug was thus distributed to the tumor in S6 but not in S2. These results suggest that somatostatin analog may have a direct anti-tumor effect. Furthermore, no side effect was observed. Thus, intraarterial infusion of somatostatin analog may be a useful therapy for liver metastasis from carcinoid.

Aged↗

PubMed1995

[Carbon-11 labeled diacylglycerol for signal transduction imaging by positron CT: evaluation of the quality and safety for clinical use].

To elucidate the synaptic transmission in the neural system, we have been developing fundamental studies for intracellular signaling. For clinical application of carbon-11 labeled diacylglycerol (1-[1-11C]butyryl-2-palmitoyl-rac-glycerol: 11C-DAG) using positron emission computed tomography (PET), we evaluated the quality and the safety of 11C-DAG as the solution for injection. As a result, 11C-DAG was synthesized within 50 minutes, including the preparation step for injection. The half life time and energy spectrum of 11C-DAG were the same as the physical character of carbon-11, and other radioisotopes were not detected. In the quality control, 11C-DAG solution was negative in the examination of bacterial contamination and the pyrogen test in three successive synthesis procedures. In the acute toxicity test by administration of 11C-DAG and 100 mumol/kg of non-radioactive DAG to the rat intravenously, the systemic condition of the rat was not changed and no abnormalities were found in any organ 24 hours after administration. These findings indicated the safety of 11C-DAG solution. Clinical application of 11C-DAG using positron emission tomography may be useful to elucidate the dysfunction of intracellular signaling in disorders of higher cortical function such as Alzheimer disease.

Animals↗

PubMed1994

Diazepam and sulpiride effects on frequency domain EEG source locations.

Effects of an anxiolytic (diazepam; n = 13) and an antipsychotic (sulpiride; n = 6) on the location of EEG model sources in the frequency domain were studied in normal volunteers in 19-channel eyes-closed EEG before and 1, 15, 30, 45 and 60 min after i.v. injections. Ten 2-second epochs from each recording were subjected to the fast Fourier transformation (FFT) Dipole Approximation which results in a single-source (in terms of phase angle) potential distribution map for each frequency point. Three-dimensional model dipole sources were fitted into the maps. Differences in source location before and after injection were computed, and differences between drugs were evaluated. The source location in the beta band shifted significantly more towards superior and anterior areas after diazepam than sulpiride, most prominently in the first minute after injection; during this time, conventional beta band power was significantly increased after diazepam versus sulpiride at all recording sites. The results demonstrate that the FFT dipole approximation adds direct 3-dimensional topographical information to power spectral results in pharmaco-EEG.

Adult↗

PubMed1994

Relationship between peripheral portal blood flow and liver function in patients with liver cirrhosis. Pulsed Doppler ultrasonographic study.

BACKGROUND: The relationship between portal hemodynamics and liver function in patients with liver cirrhosis remains unclear. METHODS: Using pulsed Doppler ultrasonography, we investigated portal hemodynamics in the trunk and the intrahepatic peripheral vessels and its relation to liver function in cirrhotic patients. RESULTS: The portal blood flow in the right anterior branch (RAB) in cirrhotic patients (n = 40) was significantly lower (p < 0.01) than that in normal subjects (n = 40). In the cirrhotic patients the portal blood flow in the RAB was significantly correlated with the values of serum albumin, total bilirubin, cholesterol, cholinesterase, prothrombin time, and ICG R-15, and that in group C (Child's grading) was significantly decreased (p < 0.01) compared with that in group A. No such difference was found in the main portal vein, the right posterior branch, or the umbilical portion of the left portal vein. CONCLUSIONS: The decrease in blood flow in the RAB is closely related to the impairment of liver function in cirrhotic patients.

Adult↗