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S Arita

Publications and source records attributed to S Arita.

At least 73 records · Page 4Linked to original sources
PubMed1993

Effect of aggressive haemoperfusion on the clinical course of patients with paraquat poisoning.

The effect of aggressive haemoperfusion; i.e. haemoperfusion of 10 h or more during the first 24 h after ingestion, on the clinical course of paraquat poisoning was studied. Among 40 patients admitted within 15 h after ingestion of paraquat with an SIPP of less than 100 (h x micrograms ml-1), 21 received aggressive haemoperfusion and 19 received conventional haemoperfusion; i.e. haemoperfusion of less than 10 h during the same period. Survival rates of patients with severity between an SIPP of 100 and Proudfoot's curve in the two groups were compared by the log-rank test. Aggressive haemoperfusion did not improve the outcome but did improve the survival rates; that is, the number of patients surviving at particular points in time (P < 0.05). The length of haemoperfusion for the aggressive haemoperfusion group was longer than that for the conventional group on the first day (P < 0.001), but the difference was insignificant during the following two days. Neither the time from ingestion to haemoperfusion, urine volume from the first to third day, nor initial plasma-paraquat concentrations and SIPP were significant between groups. These findings imply that aggressive haemoperfusion reduces the severity of paraquat poisoning and elongates survival time. We, therefore, propose that the efficacy of more aggressive haemoperfusion, such as the 'continuous haemoperfusion' proposed by Okonek et al., should be further studied.

Adolescent↗
PubMed1992

Remodeling of large bone defects in the treatment of space-occupying lesions. Curettage without bone graft for treating benign bone tumors.

Curettage without bone graft was performed in 17 patients with benign bone tumors and tumor-like lesions. New bone formation with uniformly increased radiodensity appeared in serial plain radiographs within 3 months after the operation. The average period before full weight could be borne on the lower extremities was 14 weeks. Computed tomography revealed that the central part of the bone lesions persisted without bone formation. The thickening of cortical bone was predominant. These data indicate that enough mechanical strength for daily activity will be recovered by bone within 4 months after curettage without any filler, although remodeling continues for over a year. It is suggested that bone graft and implantation of "biomaterials" are not necessary in patients, especially younger ones, with benign bone tumors or tumorous conditions.

Adolescent↗
PubMed1992

[The effect of FK506 on segmental pancreas allograft in mongrel dogs].

FK506 is a potent immunosuppressive agent on experimental and clinical organ transplantation. We studied the the effect of this agent on segmental pancreas allograft in mongrel dogs. Graft survival was prolonged significantly with continuous administration of FK506, 0.3mg/kg/day intramuscular and 1.0mg/kg/day orally. However such symptoms as loss of appetite, nausea and extreme emaciation were observed and caused death. While bolus therapy of FK506 (3 days administration with the dose of 1.0mg/kg i.m. from 4 to 6 day postoperatively) showed the same immunosuppressive effect as continuous therapy and less side effect. Furthermore it was suggested that FK506 plasma levels were concerned with the appearance of side effect. In conclusion, the administration of FK506 with plasma level monitoring was thought to be useful on pancreas transplantation.

Animals↗
PubMed1991

Evaluation of severity indexes of patients with paraquat poisoning.

1. Three indexes for evaluating the severity of paraquat poisoning based on plasma-paraquat concentration are presently in use; the curves of Proudfood et al. and Scherrmann et al. and the SIPP. Their effectiveness in determining the prognosis of patients with paraquat poisoning was evaluated. 2. To determine which index was more accurate, contigency tables of the three indexes were obtained and compared; Proudfoot's curve vs the SIPP Scherrmann's curve vs the SIPP. Proudfoot's curve and the SIPP were applied to patients admitted within 24 h after intoxication. Scherrmann's curve and the SIPP were applied to patients admitted more than 24 h after intoxication. The proportions of patients with true positive and true negative results to total patients were compared by a ratio test. 3. Proudfoot's curve was found to be more accurate than the SIPP for predicting the prognosis of patients admitted within 24 h (P less than 0.05). No significant difference, however, was noted between Scherrmann's curve and the SIPP in determining the prognosis of patients admitted after more than 24 h. 4. In conclusion, Proudfoot's curve proved a better index for predicting the outcome of patients who were admitted within 24 h. However, for the prognosis of patients admitted more than 24 h after the ingestion of paraquat, further study is required.

Evaluation Studies as Topic↗
PubMed1990

[Tissue distribution of red blood cells treated with X-ray contrast media in rats].

Tissue distribution of red blood cells (RBC) that were treated with X-ray contrast media was investigated in rats. The contrast medium mixed with an equivolume of 51Cr-labelled RBC was administered to the internal carotid artery in a dose of 200 microliters/rat; and the radioactivity in the brain, lung and spleen were determined. The contrast medium mixed with an equivolume of blood was administered to the right atrium in a dose of 4 ml/kg, and the hemoglobin content in the lung and changes in pulmonary and circulatory functions were determined. In the ionic contrast medium (meglumine diatrizoate)-treated group, the radioactivity in the brain remained 30 to 50 times higher compared with the nonionic contrast medium (iopamidol)- and saline-treated group until 15 min after infusion. The radioactivity in the spleen increased and the radioactivity and hemoglobin content in the lung decreased time-dependently in the diatrizoate-treated group, whereas iopamidol- and saline-treated groups exhibited constantly low values during the experimental period. Changes in the airway pressure, pulmonary arterial pressure, systemic blood pressure and heart rate were similar after intra-atrial administration of diatrizoate mixed with blood and diatrizoate mixed with saline. These results suggest that the ionic contrast medium affects the RBC and causes a microcirculatory disturbance in the brain.

Animals↗
PubMed1990

MR imaging of the liver before and after transcatheter hepatic chemo-embolization for hepatocellular carcinoma.

Transcatheter chemo-embolization (TCE) in hepatocellular carcinoma (HCC) was performed in 38 patients. The patients were examined by MR imaging before TCE as well as one week and 4 to 5 weeks after TCE. The tumor signal intensity in T2 weighted images increased in 13 cases and decreased in 19 cases after TCE. Increased intensity seemed to reflect intra-tumoral hemorrhage or liquefaction accompanying tumor necrosis. Decreased intensity seemed to reflect coagulation necrosis. In 9 of 18 cases followed over a 2-month period the signal intensity had decreased in both T1 and T2 weighted images. In these patients the tumor showed no recurrence at angiography and the decreased signal seemed to reflect the completion of coagulation necrosis. A hyper- and/or hypointense rim around the tumor appeared in 22 cases. These changes were thought to be perifocal edema or granulation tissue around the tumor. MR imaging was useful in evaluating the necrotic process of the tumor after TCE.

Aged↗
PubMed1990

[Application of fuzzy algorithms for ventilatory control during clinical anesthesia].

A computer program, which calculates the required minute volume using fuzzy set rule incorporating the authors' clinical experiences, was developed to keep a stable PCO2 during anesthesia, and its clinical usefulness was examined on 30 consecutive patients. The program requires the value of end-tidal CO2 concentrations at present, and 5 minutes before, and arterial-end-tidal CO2 tension difference (aEDCO2), and generates the adjustable value of minute volume to maintain the constant PaCO2 (acceptable range; 37 to 33 mmHg). Twenty-three cases were successfully controlled after adopting the calculated minute volume, which closely coincided with our clinical experiences. Seven cases, on the other hand, did not show the anticipated PaCO2 change, because of incidental leakage of endotracheal cuff (2 cases), larger aEDCO2 than the expected value of 4 mmHg (4 cases), or mild pulmonary edema (1 case). It has become clear that in the steady anesthetized patients, the program based on the authors' clinical experiences, which was made possible with the concept of fuzzy set rule, can be used to control the PaCO2 within the strict range during variable anesthetic situations.

Adult↗
PubMed1990

[Two cases of thymic cyst].

We reported two cases of thymic cyst which were accidentally found by chest X ray. On CT, they showed near water low density masses with thin walls, situated in the prevascular space. In the case 2, the septum-like structure was found by MRI, however, it was not clear by CT.

Adult↗
PubMed1989

[MR imaging of hepatocellular carcinoma following transcatheter hepatic chemo-embolization].

Transcatheter chemo-embolization (TCE) for hepatocellular carcinoma (HCC) was performed on 31 patients, and on 4 of the 31 patients, it was performed twice. The patients were examined by MR both before TCE and after TCE (1 week and 4-5 weeks respectively). On MR images, the change of the tumor signal intensity was classified into 3 groups. In group 1, (G1, 8 cases), obvious change of intensity was seen in the whole tumor. In group 2, (G2, 10 cases), it was seen in some parts of the tumor and in group 3, (G3, 17 cases), only a very slight change of intensity was seen in the whole tumor. In G1 and G2, the rate of AFP decrease was remarkable, but in G3, it was very slight. In G1 and G2, the change of the tumor signal intensity was divided into 2 types on a T2 weighted image. One, is the increase of the intensity, (6 cases). The other, is decrease of intensity, (12 cases). The former seemed to reflect the intra-tumoral hemorrhage accompanying tumor necrosis, the latter, seemed to reflect the coagulation necrosis. The ring of low and high intensity around the tumor appeared anew in 11 cases, and in 2 cases, it increased in size. These changes which have never been recognized on CT images, were thought to be a granulation tissue around the tumor. The influence of the accumulated lipiodol is slight for the change of intensity on the tumor.

Aged↗
PubMed1989

A new method for predicting the outcome and survival period in paraquat poisoning.

1. To elucidate the importance of lung damage in the prognosis of paraquat poisoning, the respiratory index (RI: A-aDO2/PO2) was analysed in 51 patients with paraquat poisoning. 2. Progressive deterioration of the RI was observed in 43 non-survivors, but not in 8 survivors. In addition, the RI of non-survivors became greater than 1.5 in the course of their poisoning, while that of the survivors remained less than 1.5. 3. The level of the RI (i.e. whether it became greater than 1.5 or not) was found to be a good indicator for the prognosis for life. 4. The RI-time, defined as the time taken from ingestion for the RI to be greater than 1.5, was found to be a good indicator for predicting the survival period in fatal cases. 5. As a result, we conclude that it is important and useful to examine a series of RI and the RI-time in poisoned patients not only to provide proper respiratory care, but also to predict outcome and survival period.

Adolescent↗
PubMed1989

[Neurotropic effects of non-ionic contrast media].

Effects of non-ionic contrast media on the central nervous system were compared in order to clarify any differences due to the side-chain structures among iopamidol, iotrolan, iocibidol, iohexol, iopromide, iosimide and metrizamide. The study included a primary screening test based on Irwin's method, antielectric convulsive tests using mice, measurement of the blood pressure using rats and electroencephalography using rats and rabbits. The general behavior of mice in the primary screening test revealed that tolerance to iopamidol, iotrolan and iocibidol was excellent; that to iopromide and iohexol was moderate; and that to iosimide and metrizamide was poor. Iosimide and iohexol suppressed the transient increase of blood pressure upon intravenous administration in the normal rats but not in the pithed rats. Electric stimulus increased the mortality of mice pretreated with iosimide and iohexol. Abnormal EEG with epileptic seizures, slow wave and/or flattening were observed with the administration of iopromide, iosimide or metrizamide as well as ionic contrast media. From these results, it was concluded that iopromide and metrizamide were not well tolerated in general behavior and EEG; iohexol, in general behavior, electroshock and blood pressure; and iosimide, in all experiments, while iopamidol, iotrolan and iocibidol were well tolerated. Therefore, small differences in their side-chain structures among these contrast media are considered to cause different effects on the central nervous system.

Animals↗