Does repeated exposure to fenitrothion alter phospholipid composition of erythrocyte membrane?
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Animals↗
Biomedical subjects
S Ishimatsu
Publications and source records attributed to S Ishimatsu.
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↗
A passive tobacco smoke exposure system for laboratory animals.
A simple passive tobacco smoke exposure system was developed for laboratory animals. The system consisted of a tobacco smoke generator and an exposure chamber. Performance testing was conducted using Fischer 344 rats. The rats were exposed to passive tobacco smoke generated by 20 cigarettes per day for 3 months. The concentration of the cigarette smoke aerosol (particle phase) in the chamber can be kept almost constant during exposure. The daily average mass concentration was 10.0 +/- 4.3 mg/m3 and the carbon monoxide was 79 +/- 22 ppm during exposure.
Animals↗
Leukocytic fragments in blood smears.
We retrospectively reviewed blood smears from patients with septic shock and/or disseminated intravascular coagulation (DIC) in order to determine whether the appearance of leukocytic fragments on blood smears has any clinical significance. Leukocytic fragments were seen in six of twelve cases with septic shock but in none of three cases of DIC without sepsis. All six cases with leukocytic fragments also showed fragmented erythrocytes. The fact that five of these six cases died and that four were dead within two days after the leukocytic fragments were noted may indicate that this appearance heralds a severe and terminal condition of sepsis. Although the exact reason for the appearance of these fragments is unclear, it seems to be related either to mechanical shearing through microangiopathic fibrin strands, which may also cause erythrocytic fragments, or to a complex alteration in the cell membrane due to bacteria, endotoxin, or other factors. We would like to stress that the presence of leukocytic fragments on blood smears provides an important clue to the patient's prognosis.
Adolescent↗
A simple apparatus to measure weakness and ataxia in the mouse.
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Animals↗
[A dietary method for epidemiological study of cancer].
A semiquantitative frequency questionnaire was developed to estimate the average intake of foods and nutrients of individuals with the aim of utilization in cancer epidemiology. Validity of the questionnaire was evaluated in comparison with four 7-day dietary records carried on 25 spouses over one year. Absolute mean intakes estimated by the questionnaire and by the records were roughly comparable at the group level. However, the individual's estimated intakes generally showed poor agreements between the two methods in terms of rank correlation, except for a few foods such as fish and milk and for alcoholic beverages. Further efforts should be exercised to develop a more accurate dietary method.
Age Factors↗
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↗
[Effects of repeated inhalation-exposure to fenitrothion powder on blood cholinesterase activity in rats].
Effects of repeated exposure to Fenitrothion (Sumithion) powder on erythrocyte membrane acetylcholinesterase (AChE) and plasma cholinesterase (PChE) were studied. Rats (Wistar, male) were exposed to fenitrothion powder for 2 hrs/day, 5 days/week for up to 3 months. The suppression of AChE and PChE increased as the exposure period and exposure concentration increased, although no suppression of AChE was found after a single 4-hr exposure. The persistence of AChE inhibition after the termination of exposure increased with the increase of the exposure period and was longer than that of PChE. Therefore, the AChE activity seems to be useful in examining the response to the repeated exposure to fenitrothion powder.
Administration, Inhalation↗
[The inhaled effects of fenitrothion powder on blood cholinesterase in rats].
Effects of fenitrothion (Sumithion) powder on red cell acetylcholinesterase (AChE) and plasma cholinesterase (PChE) were studied in vitro and in vivo. Experiments in vitro revealed that fenitrothion has almost the same potency to inhibit AChE (in pre-washed red cell membrane) and PChE. Rats (Wistar, male) were exposed to fenitrothion powder for 4 hours using a new apparatus which can generate powder constantly over a long period. In this experiment, however, no apparent suppression of AChE was found while PChE was markedly inhibited. This inhibition persisted for 3 days after the exposure. This discrepancy was interpreted to be due to the inevitable procedure in preparing red cell specimens, i.e., washing of the red cells. After acute exposure in vivo, fenitrothion appears to be easily removed from the red cells by washing. Thus, PChE, rather than AChE, seems to be a good indicator of an acute exposure to fenitrothion powder in vivo.
Animals↗
Biological half-time in rats exposed to nickel monosulfide (amorphous) aerosol by inhalation.
This study reports the biological half-time of amorphous nickel monosulfide(NiS(A)) aerosol retained in rat lungs. Wistar male rats were exposed to NiS(A) aerosols (mass median aerodynamic diameter:4.0 microns) for a single 4 h exposure, or for 7 h/d, 5 d/wk for 1 mo. The average exposure concentrations were controlled at 107 mg/m3 for the single exposure and at 8.8 mg/m3 for the repeated exposures by a dust generator consisting of a continuous fluidized bed with an overflow pipe and a screw feeder. After the exposures, the nickel contents in the rat organs, blood, and urine were measured and histopathological examinations were performed. The biological half time of NiS(A) in rat lungs was 20 h, which was extremely shorter than 21 mo of green nickel oxide (NiO(G)). There were no malignant tumors in any of the exposure groups.
Aerosols↗
Chronic neurobehavioral and central and autonomic nervous system effects of Tokyo subway sarin poisoning.
To evaluate delayed (prolonged) neurobehavioral and neurophysiological effects of acute sarin poisoning, nine male and nine female patients of the Tokyo subway sarin poisoning in Japan were examined by neurobehavioral tests, posttraumatic stress disorder (PTSD) checklist, brain evoked potentials, computerized static posturography, and electrocardiographic R-R interval variability, 6-8 months after the poisoning. Their serum cholinesterase activities on the day of the poisoning (March 20, 1995) were 13-131 (mean 72.1) IU/L. The results suggested delayed effects on psychomotor performance, the higher and visual nervous system and the vestibulo-cerebellar system with psychiatric symptoms resulting from PTSD.
Autonomic Nervous System Diseases↗
Chronic neurobehavioral effects of Tokyo subway sarin poisoning in relation to posttraumatic stress disorder.
Chronic neurobehavioral effects of acute sarin poisoning were evaluated in 9 male and 9 female patients who were exposed to sarin poisoning in the Tokyo subway incident in Japan. The investigators used nine neurobehavioral tests, as well as a posttraumatic stress disorder checklist, 6-8 mo after the poisoning occurred. Serum cholinesterase activity in patients on the day of poisoning (i.e., March 20, 1995) ranged from 13 to 131 IU/l (mean=72.1 IU/l). The results of analysis covariance, in which age, education level, alcohol consumption, and smoking status (covariates) were controlled in 18 sarin cases and in 18 controls, showed that the score on the digit symbol (psychomotor performance) test was significantly lower in the sarin cases than in controls. Nonetheless, the scores for the General Health Questionnaires, fatigue of Profile of Mood States, and posttraumatic stress disorder checklist were significantly higher in the sarin cases than controls. The investigators added posttraumatic stress disorder to the covariates, and only the score on the digit symbol test was significantly lower in sarin cases. In addition, the results of stepwise multiple regression analysis in 18 sarin cases revealed that scores for the General Health Questionnaires, fatigue of Profile of Mood States (i.e., fatigue, tension-anxiety, depression, and anger-hostility)-together with the paired-associate learning test-were associated significantly with posttraumatic stress disorder. The association did not remain significant for the digit symbol test score. Perhaps a chronic effect on psychomotor performance was caused directly by acute sarin poisoning; on the other hand, the effects on psychiatric symptoms (General Health Questionnaire) and fatigue (Profile of Mood States) appeared to result from posttraumatic stress disorder induced by exposure to sarin.
Adult↗