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Y Ogata

Publications and source records attributed to Y Ogata.

At least 73 records · Page 4Linked to original sources
PubMed1999

Stirring system for radioactive waste water storage tank.

A stirring system for 100-m(3) radioactive liquid waste tanks was constructed to unify radioactive concentrations in the tank. The stirring system is effective in certifying that the radioactive concentrations in the tanks are less than the legal limits before they are drained away as waste liquid. This system is composed of discharge units, pipe lines, and a controller. The performance of the system was assessed by comparing the calculated red ink and 32P concentrations with those monitored at six locations in the tanks. The concentration reached equilibrium after stirring 60 to 120 min with discharge units equipped with six fixed openings configured in differing directions. Residual chlorine in city water used for dilution occasionally bleached the red ink and reduced its concentration. The adsorption of 32P by slime on the walls of the tanks storing actual waste water lowered the equilibrium concentration.

Radioactive Waste↗
PubMed1999

Treatment strategy for pancreatic head cancer: pylorus-preserving pancreatoduodenectomy, intraoperative radiotherapy and portal catheterization.

Pancreatic cancer is the disease of gastrointestinal cancer with the poorest prognosis. At present, in addition to surgery, multimodality treatment combining a variety of therapeutic methods is used. We usually employ the following combination of surgery, radiotherapy and chemotherapy: D2 surgery with pylorus-preserving pancreatoduodenectomy (PPPD), intraoperative radiotherapy (IORT), and portal catheterization (PC) with fluorouracil as the chemotherapy. In this study, we made a historical comparison of PPPD and PD and obtained the following findings: (1) PPPD allows almost the same extent of D2 dissection as conventional PD, and achieves radical treatment without any problems; (2) suppression of local recurrence by IORT cannot be expected from the results of the comparison between the four approaches, i.e. surgery alone, surgery + IORT, surgery + PC and surgery + IORT + PC, and (3) the rate of liver metastasis in patients treated by PC was significantly low.

Catheterization↗
PubMed1999

[Screening of prostate cancer with PSA and transperineal six sextant biopsy].

OBJECT: The objectives of this study are to examine how many cancer patients we can detect among the outpatients whose PSA values are above 4.0 ng/ml, and to compare the usefulness of transperineal six sextant biopsy (ss-biopsy) with that of transrectal one. METHODS: All the male outpatients (above 50 years old) were inspected Tandem-R PSA levels and digital rectal examination (DRE). Among them, 129 patients showed more than 4.0 ng/ml of PSA values and/or positive finding of DRE, and underwent subsequent transperineal ss-biopsy. RESULTS: Cancers were detected in 52 patients (40.3%) without major complications. Among 64 gray zone (PSA 4.1-10.0 ng/ml) patients, 17 (26.6%) were found to be cancer by ss-biopsy, meanwhile only 2 cancer patients (8.9%) were detected from 23 gray zone ones by traditional directed biopsy. Application of PSA density could not be found practicable to eliminate unnecessary biopsies in the gray zone group. CONCLUSION: Prostate cancer could be found nearly a fourth in the gray zone group of the outpatients. To enhance the detection rate, obtaining at least 6 core samples are recommended from either perineal or rectal root.

Aged↗
PubMed1999

[Preliminary evaluation of adjuvant chemotherapy against stage Ib or II gastric cancer].

The prognostic influence of post-operative adjuvant chemotherapy on stage I b or II gastric cancer was studied retrospectively. The immunohistochemical expressions of p53 protein and thymidine phosphorylase (TP) were also examined; the relations between these protein expressions and clinicopathological features along with the effect of adjuvant chemotherapy were also investigated. The 5-year survival rate of the patients who received adjuvant chemotherapy was 95.5%, which was better than that (89.8%) of those who did not, although the difference did not reach significance (p = 0.09). The venous invasion of tumor was slight frequently observed in p53 or TP positive cases than negative cases, respectively (p < 0.1), but no significant associations were found between the t-, n- or ly-factor, and p53 or TP expression. Moreover p53 and TP expression had no significant influence on post-operative survival. But, among the patients with p53- or TP-positive tumor, adjuvant chemotherapy conferred survival benefits, although the difference did not reach significance. The 5-year survival rate was 100% with adjuvant chemotherapy, 84.3% without chemotherapy in p53-positive patients (p = 0.137), 97.0% with adjuvant chemotherapy, and 90.8% without chemotherapy in TP-positive tumors (p = 0.326).

Administration, Oral↗
PubMed1999

Detection of activated eosinophils in nasal polyps of an aspirin-induced asthma patient.

Aspirin-induced asthma (AIA) is frequently accompanied by nasal polyps. Eosinophil infiltration is a characteristic feature of nasal polyps associated with AIA. Even though steroids are well known to be effective on managing AIA and its nasal polyps, histochemical examinations after steroid therapy and at recurrence, involving eosinophil infiltration of nasal polyps, have been less studied. To know the histochemical effects of steroid treatment on eosinophil accumulation in nasal polyps of AIA and the histochemical feature of a recurring polyp and to detect distributional differences between storage and secreted forms of eosinophil cationic proteins, we carried out immunocytochemical labelling with antibodies against EGI (recognizing resting and activated eosinophils) and EG2 (recognizing only activated eosinophils), and determined eosinophil infiltration in nasal polyps that were obtained before and after steroid treatment, and at recurrence of polyps. A large number of eosinophils in AIA polyps were found before steroid treatment and at recurrence, and they were predominantly composed of activated eosinophils (EG2-positive). In contrast, eosinophil infiltration was rare in polyps obtained immediately after steroid treatment. This finding suggests that eosinophil infiltration may be associated with nasal polyp formation in AIA, and that activation of eosinophils plays an important role in accumulation of eosinophils and polyp formation beginning with the initial stage.

Adrenal Cortex Hormones↗
PubMed1999

Comparison of vestibular and cochlear ototoxicity from transtympanic streptomycin administration.

HYPOTHESIS: The relative dose-related cochlear and vestibular ototoxicity produced by transtympanically injected streptomycin (SM) compared to that of gentamicin (GM) was assessed. BACKGROUND: Although SM, the first aminoglycoside used transtympanically, is thought to be selectively vestibulotoxic, it has been replaced by GM in current clinical use. Little experimental data exist that directly demonstrate the relative cochlear and vestibular ototoxicity resulting from transtympanic administration of SM compared to GM. METHODS: Histologic evaluation was performed on inner ears from Mongolian gerbils to study vestibular and cochlear damage. Comparisons were made between animals receiving single (1 x SM) and five daily (5 x SM) injections of SM/Gelfoam-slurry and similarly injected and noninjected controls. These data were compared to results obtained using GM (1 x GM and 5 x GM) reported previously. RESULTS: Two weeks after injection, parallel qualitative and quantitative changes were seen in posterior cristae and cochlear sensory epithelia in the 1 x and 5 x SM injected groups, similar to those resulting from GM injections. Statistically significant decreases in number of hair cells were seen when 5 x SM injected ears were compared to 1 x SM injected ears and control ears. Increased damage was seen with increased dosage of each drug. Whenever damage was observed to the posterior crista sensory cells, damage was also seen in cochlear hair cells. CONCLUSIONS: In this model, SM and GM produced significant cochlear damage when vestibular damage occurred. These results suggest that, in the gerbil, SM and GM are ototoxic but not selectively vestibulotoxic. Increasing the number of transtympanic injections generally increases the damage to sensory hair cells in the posterior crista and the cochlea. A variation in interanimal susceptibility to ototoxic effects exists, but the amount of damage is consistent in cochlear and vestibular hair cells from the same animal. No evidence for selective vestibular ototoxicity from transtympanic SM was found.

Administration, Topical↗
PubMed1999

[A follow-up study on effects of ADL deterioration on QOL in patients with neurological intractable diseases].

OBJECTIVE: This follow-up study examined correlating factors, including change of activity of daily living (ADL), which are associated with subjective quality of life (QOL) in patients with neurological intractable diseases such as amyotrophic lateral sclerosis, spinocerebellar degeneration and Parkinson disease. METHODS: Baseline information of 159 patients with above mentioned three intractable diseases registered by two public health centers in Niigata and Fukuoka Prefectures was obtained in 1993-1994, and they were followed to 1995. At the end of follow-up, 124 subjects were interviewed by public health nurses using the 27 item-subjective QOL scale for patients with neurological intractable diseases, previously confirmed for reliability and validity. RESULTS: Low level of ADL at the time of registry and deterioration of ADL after the registry were independently related to low level of subjective QOL. CONCLUSIONS: It may be necessary to minimize the ADL deterioration, in order to maintain a high subjective QOL of patients with neurological intractable diseases.

Activities of Daily Living↗
PubMed1998

Large-scale preparation of human thrombin: polyethylene glycol potentiates the factor Xa-mediated activation of prothrombin.

We investigated the ability of polyethylene glycol 4000 to accelerate thrombin generation in a mixture of prothrombin and factor X at concentrations of 1-30%. In the presence of 5 mM of CaCl2, polyethylene glycol 4000 promoted prothrombin activation at concentrations above 1%. The peak of activation was seen at levels of 14 and 20% of polyethylene glycol 4000. The effect of the polyethylene glycol was remarkably dependent on its molecular weight; molecular weights greater than 2000 were required for accelerating thrombin generation. Under optimal conditions, polyethylene glycol 4000, in the presence of CaCl2, promoted conversion of all of the prothrombin into thrombin and its derivatives. We conclude that polyethylene glycol 4000, at concentrations ranging from 14 to 20%, effectively accelerates thrombin generation in the presence of 5 mM of CaCl2. This new method for preparing thrombin is based on the use of polyethylene glycol 4000 and CaCl2 and is applicable to the manufacture of thrombin.

Calcium Chloride↗
PubMed1998

Noninvasive assessment of significant left anterior descending coronary artery stenosis by coronary flow velocity reserve with transthoracic color Doppler echocardiography.

BACKGROUND: Coronary flow reserve has been considered an important diagnostic index of the functional significance of coronary artery stenosis. With Doppler technique, it has been assessed as the ratio of hyperemic to basal coronary flow velocity (coronary flow velocity reserve [CFVR]) by invasive or semiinvasive methods with a Doppler catheter, a Doppler guide wire, and a transesophageal Doppler echocardiographic probe. Recent technological advancement in transthoracic Doppler echocardiography (TTDE) provides measurement of coronary flow velocity in the distal portion of the left anterior descending coronary artery (LAD) and may be useful in the noninvasive CFVR measurement. The purpose of this study was to evaluate the value of CFVR determined by TTDE for the assessment of significant LAD stenosis. METHODS AND RESULTS: We studied 36 patients who underwent coronary angiography for the assessment of coronary artery disease. The study population consisted of 12 patients with significant LAD stenosis (group A) and 24 patients without significant LAD stenosis (group B). With TTDE, coronary flow velocities in the distal LAD were recorded at rest and during hyperemia induced by intravenous infusion of adenosine (0.14 mg x kg(-1) x min(-1)) under the guidance of color Doppler flow mapping. Adequate spectral Doppler recordings of coronary flow in the distal LAD for the assessment of CFVR were obtained in 34 of 36 study patients (94%). The peak and mean diastolic coronary flow velocities at baseline did not differ between groups A and B (23.6+/-10.3 versus 22.9+/-6.6 cm/s and 16.4+/-8.6 versus 14.5+/-4.0 cm/s, respectively). However, the peak and mean coronary flow velocities during hyperemia in group A were significantly smaller than those in group B (35.6+/-16.3 versus 54.2+/-16.3 cm/s and 24.7+/-13.1 versus 37.9+/-13.0 cm/s, respectively; P<.01). There were significant differences in CFVR obtained from peak and mean diastolic velocity between groups A and B (1.5+/-0.2 versus 2.4+/-0.4 and 1.5+/-0.2 versus 2.6+/-0.4, respectively; P<.001). A CFVR from peak diastolic velocity <2.0 had a sensitivity of 92% and a specificity of 82% for the presence of significant LAD stenosis. A CFVR from mean diastolic velocity <2.0 had a sensitivity of 92% and a specificity of 86% for the presence of significant LAD stenosis. CONCLUSIONS: CFVR determined by TTDE is useful in the noninvasive assessment of significant stenotic lesion in the LAD.

Adult↗
PubMed1998

Eosinophilia associated with adult T-cell leukemia: role of interleukin 5 and granulocyte-macrophage colony-stimulating factor.

To clarify the mechanism of eosinophilia in adult T-cell leukemia (ATL), we studied three ATL patients having marked eosinophilia. Eosinophil-predominant colony-stimulating activity was detected in the serum of one patient and in the conditioned media (CM) from cultured ATL cells from two patients. Soluble interleukin 5 (IL-5), but no interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was detected in sera from all patients. On the other hand, GM-CSF was produced in vitro by ATL cells from all cases, whereas detectable IL-3 and IL-5 was produced by cells from only one, suggesting that in the other two cases, the serum IL-5 was produced by the normal reacting lymphocytes. The fact that no patient showed marked neutrophilia supports the possibility that IL-5 may have a leading role in the development of eosinophilia, with GM-CSF produced by ATL cells playing a complementary role.

Aged↗
PubMed1998

Characterization of gastric Na+/I- symporter of the rat.

Characterization of gastric Na+/I- symporter (NIS) of the rat was carried out. Sequencing of the open reading frame of gastric NIS mRNA showed only three nucleotide changes when compared with FRTL-5 NIS cDNA, and two of these changes led to amino acid changes. The results of Northern blot analysis showed that abundant NIS mRNA was expressed in the stomach when compared with other organs. Western blot analysis using gastric mucosa and FRTL-5 lysates detected the difference in molecular weight between FRTL-5 and gastric mucosa lysates, suggesting abnormal posttranslational modification of gastric NIS protein. Immunohistochemically, gastric NIS protein was located in the cornification layer of the stratified squamous epithelium of the pars proventricularis and in parietal cells and on the apical border of surface epithelial cells of the pars glandularis. Gastric NIS protein was present in tubulovesicular structures and lysosomes in parietal cells by immunoelectron microscopy. Gastric NIS protein exists to trap I- from the gastric lumen, except in parietal cells. Results indicated that a very large amount of gastric NIS mRNA is expressed to be translated, whereas only a small amount of immature gastric NIS protein is detected. This may indicate that immature gastric NIS protein rapidly degrades to peptides.

Animals↗
PubMed1998

Effect of liposome-encapsulated hemoglobin, neo red cells, on hemorrhagic shock.

We examined the effects of liposome-encapsulated hemoglobin, neo red cells (NRCs), on hemorrhagic shock in a canine model. The dogs were divided into the three groups according to treatment. In group 1, composed of six dogs, NRCs were substituted for blood without shock being induced; in group 2, composed of six dogs, NRCs were administered immediately after mild shock had been induced by exsanguination through the vein; and in group 3, composed of seven dogs, NRCs were administered after they had been left untreated for 30 min inducing severe shock. In group 2, administration of NRCs at a dose equivalent to the volume of exsanguinated blood improved the symptoms of shock; however, in group 3, a dose of NRCs 1.6-times the volume of exsanguinated blood was required. Peripheral vascular resistance (PVR) decreased after NRC administration in groups 1 and 2, but increased in group 3. On the other hand, the cardiac index (CI) increased in groups 1 and 2, and decreased in group 3. Concerning oxygen kinetics, there were no increases in the oxygen requirements or arteriovenous differences of the oxygen content per hemoglobin (AV/Hb) for NRCs in groups 1 and 2. Conversely, in group 3, the oxygen requirements increased and the NRCs compensated for the decrease in CI with an increase in AV/Hb by enhancing the oxygen transport efficiency to cope with the increased oxygen requirements.

Animals↗
PubMed1998

Surgical treatment of lower rectal cancer with sphincter preservation using handsewn coloanal anastomosis.

The present study was designed to evaluate the technical feasibility and oncologic results of performing handsewn coloanal anastomosis (CAA). A total of 46 patients treated for lower rectal cancer using CAA were retrospectively studied, and the oncologic results were compared with those of 105 patients treated with abdominoperineal resection (APR). CAA was performed in patients who had both good mobility of the tumor and a distal clearance margin of more than 1.0 cm. No significant difference was noted in the mortality rates following the two operations (CAA 2.2% vs APR 1.9%). Pelvic recurrence was detected in two patients (4.5%) after CAA and in six patients (7.2%) after APR. The 5-year survival rate after CAA was 79.2% and that after APR was 72.6%. No significant difference was noted in the incidence of pelvic recurrence or the survival rates between the two operations. These results show that CAA could be an excellent reconstructive option in the treatment of lower rectal carcinoma for selected patients.

Adenocarcinoma↗
PubMed1998

Results of surgery and adjuvant radiotherapy for pancreatic cancer.

We retrospectively reviewed the cases of 34 patients with pancreatic cancer who underwent resection between January 1988 and December 1996. Adjuvant radiotherapy was performed in 24 patients, with 13 receiving both intra- and postoperative radiotherapy, 2 receiving postoperative radiotherapy (PORT) alone, and 9 receiving intraoperative radiotherapy (IORT) alone. The 1- and 3-year survival rates for all 34 patients were 59% and 19%, respectively, with a median survival of 13 months. At the time of the analysis, three patients were still alive. Recurrence patterns were assessed in 25 patients who had had no distant metastases at the time of surgery, had survived more than 3 months after surgery, and had undergone close surveillance for recurrence. Based on computed tomography (CT) and autopsy findings, a total of 15 (60%) of these 25 patients had local recurrence, 13 (52%) had liver metastases, and 8 (32%) had both. Eight (62%) of the 13 patients who received IORT and/or PORT developed local recurrence, and we failed to detect any survival advantage of IORT and/or PORT over surgery alone. However, autopsies revealed a suppressive effect of radiation on cancer growth, and local recurrence was not considered to be the direct cause of death in any of the patients, nor did any of the patients develop gastrointestinal obstruction due to local recurrence. The incidence of liver metastasis in the patients with and without tumor invasion of the portal system was 80% (8/10) and 33% (5/15), respectively. The patients who did not develop liver metastasis had significantly longer survivals than who did. Further improvements of survival await effective prophylactic treatment for liver metastases.

Adult↗
PubMed1998

Noninvasive assessment of coronary flow velocity and coronary flow velocity reserve in the left anterior descending coronary artery by Doppler echocardiography: comparison with invasive technique.

OBJECTIVES: The purpose of this study was to evaluate whether transthoracic Doppler echocardiography (TTDE) can reliably measure coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) in the clinical setting. BACKGROUND: Coronary flow velocity measurement has provided useful clinical and physiologic information. Advancement in TTDE provides noninvasive measurement of CFV and CFVR in the distal LAD. METHODS: In 23 patients, CFV in the distal LAD was measured by TTDE (5 or 3.5 MHz) under the guidance of color Doppler flow mapping at the time of Doppler guide wire (DGW) examination. Coronary flow velocity in the distal LAD were measured at baseline and hyperemic conditions (intravenous administration of adenosine 0.14 mg/kg/min) by both TTDE and DGW techniques. Coronary flow velocity reserve was defined as the ratio of peak hyperemic to basal averaged peak velocity in the distal LAD. RESULTS: Clear envelopes of basal and hyperemic CFV in the distal LAD were obtained in 18 (78%) of 23 study patients by TTDE. There were excellent correlations between TTDE and DGW methods for the measurements of CFV (averaged peak velocity: r=0.97, y=0.94x + 0.40; averaged diastolic peak velocity: r=0.97, y=0.94x + 0.69; systolic peak velocities: r=0.97, y=0.91x + 0.87; diastolic peak velocity: r=0.98, y=0.95x + 1.10). Coronary flow velocity reserve from TTDE correlated highly with those from DGW examinations (r=0.94, y=0.95x + 0.21). CONCLUSIONS: Noninvasive measurement of CFV and CFVR in the distal LAD using TTDE accurately reflects invasive measurement of CFV and CFVR by DGW method.

Adenosine↗
PubMed1998

Visualization of clear echocardiographic images with near field noise reduction technique: experimental study and clinical experience.

BACKGROUND: With transthoracic echocardiography, it is sometimes difficult to obtain a clear image of the apical portion of the heart because of noise near the transducer. To reduce this artifact, we have developed a new technique (near field noise reduction, NFNR) based on the digital filtering by using radiofrequency signals. This technique may be useful for the accurate measurement of the wall thickness of the myocardium in the near field. The objectives of these studies were (1) to determine the accuracy of this new technique for the measurement of wall thickness in the experimental study and (2) to determine whether the improvement in the image quality in the apical portion can be obtained in the clinical setting by using the NFNR technique. EXPERIMENTAL STUDY: By using the NFNR technique, we measured wall thickness of three kinds of phantoms (wall thickness 9.0, 14.0, and 21.0 mm) moving at various velocities (5 to 80 mm/sec) in the water bath with artifact produced by a single probe. It was difficult to obtain clear echocardiographic images of the phantom and measure its wall thickness because of the artifact. By using the NFNR technique, on the other hand, the same phantom was clearly imaged. It was possible to measure the wall thickness of each phantom at each moving velocity with the NFNR technique. Mean differences between the echocardiographic measurement and actual value of wall thickness in each phantom model (9.0, 14.0, and 21.0 mm) were 0.04 +/- 0.58 mm, 0.09 +/- 0.58 mm, and -0.02 +/- 0.24 mm, respectively. CLINICAL STUDY: We studied 25 initial patients in whom the near field was not clearly imaged in apical views by conventional echocardiography because of near field noise. Apical four-chamber or two-chamber views were obtained with and without the NFNR technique. Two observers independently graded endocardial visualization for the 50 segments by using a three-point scale (0 = endocardium not seen, 1 = seen in part but not all of the segment, 2 = endocardium seen along entire segment). The mean segment score in the imaging with the NFNR technique was significantly higher than that without the NFNR technique (observer 1: 1.8 +/- 0.7 vs 1.2 +/- 0.8, p < 0.01; observer 2: 1.6 +/- 0.7 vs 1.2 +/- 0.8, p < 0.01). CONCLUSIONS: The newly developed NFNR technique provides clear echocardiographic images and accurate wall thickness measurement in the experimental model even when it is difficult to obtain clear images because of the artifact. This new technique will be useful in the reduction of near field noise in the clinical setting.

Echocardiography↗
PubMed1998

Complications after pylorus-preserving pancreatoduodenectomy with gastrointestinal reconstruction by the Imanaga method.

BACKGROUND: Pylorus-preserving pancreatoduodenectomies (PPPDs) have been performed for disorders of the pancreatic head and periampullary region. The most commonly used reconstructive technique anastomoses the duodenum end-to-side to the jejunum, with pancreatic and biliary anastomoses placed proximally to the end-to-side duodenojejunostomy. In contrast, we have favored PPPD with gastrointestinal reconstruction by the Imanaga method (PPPD-Imanaga), which consists of end-to-end duodenojejunostomy, end-to-side pancreatojejunostomy, and choledochojejunostomy, performed in that order, because the PPPD-Imanaga provides a physiologic mixture of food, pancreatic juice, and bile in the upper portion of the jejunum. STUDY DESIGN: To identify their postoperative complications, we retrospectively reviewed the cases of 55 patients who underwent a PPPD-Imanaga between December 1986 and December 1996. In all cases, the right gastric artery was divided and the pancreatic duct was sewn directly to a small opening in the jejunal mucosa. Twenty patients with malignancy received adjuvant radiotherapy. RESULTS: Five patients died without being discharged, including one who died of cancer progression, for a postoperative mortality rate of 9%. These deaths were limited to patients who had received adjuvant radiotherapy, with only two deaths being procedure related. Delayed gastric emptying, pancreatic leak, and marginal ulcer were observed in 25 (45%), 3 (5%), and 3 (5%) patients, respectively. The delay in gastric emptying was transient and resolved spontaneously, with no patients undergoing reoperation. Only one patient required a reoperation, for the control of intraabdominal bleeding. CONCLUSIONS: A PPPD-Imanaga can be performed with acceptable morbidity and mortality risks. We conclude that the Imanaga method is a favorable complement to PPPD.

Adult↗