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Biomedical subjects

S Tadokoro

Publications and source records attributed to S Tadokoro.

At least 109 records · Page 6Linked to original sources
PubMed1986

[Two cases of bladder leiomyoma].

Two cases of leiomyoma of the bladder are reported. The first case was a 79-year-old female who presented with gross hematuria and frequent urination. Cystoscopy disclosed a large tumor covered by intact mucosa. This lesion was further evaluated by ultrasound, and was thought to be a submucosal tumor of the bladder. The second case was a 43-year-old female who was referred for further investigation of left giant hydronephrosis. During the investigation, submucosal tumor was incidentally found. Concerning the etiology of the hydronephrosis, left ureteral stenosis due to a previous gynecological operation was suspected. These lesions proved to be leiomyoma of the bladder histologically, and were successfully enucleated. Difficulty in diagnosis of this disease and controversy as to the optimal treatment prompted us to report these cases and to review 68 cases reported in the Japanese literature.

Adult↗
PubMed1986

[Effects of repeated administration of bromocriptine on ambulatory activity in mice, and changes in methamphetamine sensitivity in bromocriptine-experienced mice].

Effects of repeated administration of bromocriptine, a long-acting dopamine agonist, as well as interaction between bromocriptine and methamphetamine were investigated by mean of ambulatory activity in mice. The ambulatory activity of each mouse was measured by a tilting-type activity cage for 6 and 3 hr after administration of bromocriptine and methamphetamine, respectively. The repeated 5 times administration of bromocriptine and of methamphetamine was at intervals of 7 days and of 3-4 days, respectively. Bromocriptine tended to suppress the activity at low doses (1 and 2mg/kg, ip), but increased the activity at high doses (8 and 16 mg/kg, ip), showing biphasic effects depending on the doses administered. Both the ambulation-suppressing and -increasing effects of bromocriptine were enhanced when the drug was repeatedly administered. The mice that experienced the repeated administration of low doses and high doses of bromocriptine exhibited a decrease and an increase, respectively, in the sensitivity to the ambulation-increasing effect of methamphetamine (2 mg/kg, sc). Repeated administration of methamphetamine (2 mg/kg, sc) elicited an increase in sensitivity not only to methamphetamine itself, showing reverse tolerance, but also to high doses of bromocriptine, showing cross reverse tolerance. However, the reverse tolerance to methamphetamine, once produced, was not affected by the repeated administration of low doses of bromocriptine.

Animals↗
PubMed1985

Effects of psychoactive drugs on conditioned avoidance response in Mongolian gerbils (Meriones unguiculatus): comparison with Wistar rats and dd mice.

In order to examine applicability of Mongolian gerbils as experimental animals in the field of behavioral pharmacology, the acquisition process of a discrete lever-press avoidance response and effects of psychoactive drugs thereon were studied. The results were compared with those in Wistar rats and dd mice. The gerbils learned the avoidance response much better than the rats and mice. The response rates established were higher in an order of the mice, the gerbils and the rats. Methamphetamine (0.13-1 mg/kg SC), cocaine (2.5-20 mg/kg SC) and morphine (1.3-10 mg/kg SC) facilitated the gerbils' avoidance response, i.e., eliciting a dose-dependent increase in the response rate and a slight increase in the avoidance rate. In contrast, chlorpromazine (0.5-4 mg/kg SC), haloperidol (0.025-0.2 mg/kg SC), pilocarpine (1-8 mg/kg SC), physostigmine (0.05-0.4 mg/kg SC), pentobarbital (5-20 mg/kg SC) and diazepam (0.5-2 mg/kg SC) suppressed the gerbils' avoidance response, i.e., eliciting a dose-dependent decrease in both the response and avoidance rates. Atropine (1.3-10 mg/kg SC) decreased only the response rate without a marked change in the avoidance rate. Scopolamine (0.031-0.5 mg/kg SC) did not produce a marked change in the avoidance response. The qualitative changes in the avoidance response in the gerbils were similar with those in the rats and mice after administration of central stimulants, antipsychotics, cholinergic agonists, central depressant and antianxiety drug, though the sensitivities were different. In particular, the gerbils showed a high sensitivity to the avoidance-suppressing effect of diazepam.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Learning retardation and enhanced ethanol preference produced by postnatal pretreatments with ethanol in adult rats.

Male neonates of Wistar strain rats were given 0.63-2.50 g/kg/day of ethanol, i.p., for 7 successive days from day 6 to 12 after birth. The acquisition processes of the discriminated lever-press avoidance response (intertrial interval: 25 sec, warning stimuli presentation: 5 sec, foot shock intensity: 110V, 0.5 mA, 50 Hz, AC) were investigated for 20 separate sessions from day 60 after birth. The preference test for ethanol was done beginning at 120 days of age. No significant differences in body weights were detected between saline- and ethanol-pretreated groups. However, learning retardation was observed in all groups pretreated with ethanol. In these groups, slow responses to warning stimuli followed by escape responses from shocks delivered were often observed in early training sessions. An enhanced preference for ethanol was observed in all groups pretreated with ethanol for 7 successive days at maturity. These results suggest the possibility that learning ability and preference for ethanol in adult rats are strongly influenced by pretreatments with ethanol during the early postnatal period.

Aging↗
PubMed1985

Comparisons between discrete lever-press and shuttle avoidance responses in mice: acquisition processes and effects of psychoactive drugs.

Acquisition processes of discrete lever-press (L-type) and shuttle (S-type) avoidance responses as well as effects of psychoactive drugs thereon were investigated in dd strain mice. The mice showed a more rapid acquisition of S-type avoidance than L-type. However, the mean avoidance rates and occurrences of good-performing mice (showing an avoidance rate of higher than 75%) were almost the same in both types when the training was carried out for more than 15 sessions of 1 hr each. The response rate of L-type avoidance was 2.5-3 times as high as that of S-type avoidance. Methamphetamine and cocaine increased the response rate in almost the same grade in both types of avoidance. Chlorpromazine, haloperidol, pilocarpine and physostigmine suppressed both L-type and S-type avoidance responses. However, the L-type showed a higher sensitivity than the S-type to the avoidance-suppressing effect of these drugs. Atropine, scopolamine and morphine suppressed L-type avoidance response, while they facilitated S-type avoidance. The drug-induced changes in the response rate of the S-type were well correlated with those in the ambulatory activity. The changes in the response rate of the L-type were also consistent with those in the ambulatory activity after administration of methamphetamine, cocaine, chlorpromazine, haloperidol, pilocarpine and physostigmine, but inconsistent after atropine, scopolamine and morphine. The present results suggest that L-type and S-type avoidance responses in mice sometimes show a different change after administration of psychoactive drugs.

Animals↗
PubMed1985

Changes in 3H-spiperone, 3H-WB 4101 and 3H-dihydroalprenolol bindings to brain membranes produced by postnatal pretreatment with chlorpromazine in adult rats.

In order to elucidate possible mechanisms of the learning deficit produced by postnatal pretreatment with chlorpromazine (CPZ), changes in catecholamine receptors in the rat brain were investigated. Male neonates of Wistar strain rats were given s.c. 2 mg/kg/day of CPZ for 7 successive days from days 6 to 12 after birth. Effect of the postnatal pretreatment with CPZ on saturation constants for specific bindings of 3H-spiperone, 3H-WB 4101 and 3H-dihydroalprenolol, respectively, in 8 brain regions was investigated at 60 days after birth. Significant decreases in Bmax values of 3H-WB 4101 binding sites in the cortex, thalamus, hypothalamus, mid brain and medulla oblongata/pons and decreases in Kd values of the binding sites in thalamus, hypothalamus and mid brain were observed in CPZ-pretreated rats when compared with corresponding Bmax and Kd values obtained in saline-pretreated rats. Furthermore, significant decreases in both Bmax and Kd values of 3H-DHA binding sites in the thalamus were detected in CPZ-pretreated rats when compared with those obtained in saline-pretreated rats. However, no alterations in 3H-spiperone binding sites in all brain regions were found between CPZ- and saline-pretreated rats. These results suggest that the learning deficit observed in CPZ-pretreated rats may be produced by a functional disorder of catecholaminergic, in particular alpha 1-noradrenergic neurons in the brain.

Adrenergic alpha-Antagonists↗
PubMed1985

Effects of diazepam and pentobarbital on discrete lever-press avoidance response in mice: baseline-dependent changes.

Effects of diazepam (0.5, 1, 2 and 4 mg/kg, sc) and pentobarbital (5, 10, 20 and 30 mg/kg, sc) on discrete lever-press avoidance response in the dd strain mice were investigated in consideration of the baseline avoidance levels. The dose-effect relations were obtained with 4 groups of mice showing the baseline avoidance rates of 0-24% (Group 1), 25-49% (Group 2), 50-74% (Group 3) and 75-100% (Group 4). In Group 1, both diazepam (0.5-2 mg/kg) and pentobarbital (5-20 mg/kg) increased the avoidance rate without a marked change in the response rate (frequency of lever-pressings). A significant increase in the avoidance rate was observed when 1 mg/kg of diazepam and 10 mg/kg of pentobarbital were administered. In contrast, both diazepam and pentobarbital decreased the response and avoidance rates in Groups 2-4. These results suggest that the effects of diazepam and pentobarbital on the avoidance response in mice vary depending on the baseline avoidance levels.

Animals↗
PubMed1985

Combined effects of methamphetamine and morphine on ambulatory activity in mice and continuous avoidance response in rats.

Combined effects of methamphetamine and morphine were investigated by means of ambulatory activity in mice and continuous avoidance response in rats. Single administration of methamphetamine (0.5-2 mg/kg sc) or morphine (2.5-10 mg/kg sc) increased the ambulatory activity in a dose-dependent manner. The ambulation-increasing effect of methamphetamine and morphine were synergistic throughout the combined doses tested. Methamphetamine (0.13 and 0.5 mg/kg sc) produced an increase in frequency of lever-pressing and a decrease in shock rate, showing facilitation of the avoidance response, in a dose-dependent manner. Morphine tended to facilitate the avoidance response at lower doses (1.3 and 2.5 mg/kg sc), whereas, at higher doses (5 and 10 mg/kg sc), it elicited decrease in the frequency of lever-pressing and increase in the shock rate, showing suppressing of the avoidance response. The avoidance-facilitating effect of methamphetamine was attenuated by higher doses of morphine. The present results suggest that combined administration of methamphetamine and morphine shows synergistic effect on ambulatory activity in mice, and synergistic and antagonistic effects on the avoidance response in rats depending on the doses combined.

Animals↗
PubMed1985

Chronopharmacological study on morphine-induced increase in ambulatory activity in mice and methamphetamine sensitivity in morphine-experienced mice.

Effect of morphine (5 and 10 mg/kg sc) on ambulatory activity was investigated at different times of day (administration at 3:00, 7:00, 11:00, 15:00, 19:00 and 23:00) in mice housed under a normal light-dark condition (light period; 6:00-18:00). Morphine increased the ambulatory activity in a dose-dependent manner when it was administered to the drug-naive mice. There was no clear circadian variation in the increased ambulatory activity. The repeated administration of morphine (10 mg/kg) at intervals of 7 days produced an augmentation in the sensitivity to the ambulation-increasing effect of morphine independently of the times of day, and the mean overall ambulatory activity counts during 3 hr observation period in the 5th administration were about 2 times as high as corresponding those in the 1st administration. The mice experienced the repeated administration of morphine (10 mg/kg) for 5 times during the mid-late light, and mid dark (administration at 11:00, 15:00 and 23:00) showed an increased sensitivity to the ambulation-increasing effect of methamphetamine (1 mg/kg sc). However, the circadian variation in sensitivity to methamphetamine, which was highest and lowest during the dark and light periods, respectively, was still maintained even in the morphine-experienced mice.

Animals↗
PubMed1984

Conditioned lever-press avoidance response in mice: acquisition processes and effects of diazepam.

Acquisition of conditioned lever-press avoidance behavior on a continuous avoidance schedule (response-shock interval = 30 s and shock-shock interval = 5 s) and on a discrete avoidance schedule (intertrial interval = 25 s and duration of the warning presentation = 5 s with an escape contingency) in dd mice was investigated. When the behavioral baseline had stabilized, the effects of diazepam on avoidance behaviors were examined. About 60% and 80% of the mice achieved criterion levels of avoidance behavior under continuous avoidance (shock rate being less than 0.5/min) and discrete avoidance (avoidance rate being higher than 75%), respectively. Diazepam (0.5--4 mg/kg SC) dose-dependently impaired avoidance behavior of mice which had a low baseline shock rate and a high baseline avoidance rate under continuous and discrete avoidances, respectively. The changes in avoidance behavior in mice after diazepam were almost identical with those previously found in rats.

Analysis of Variance↗
PubMed1984

Circadian variation in susceptibility to methamphetamine after repeated administration in mice.

Since repeated administration of methamphetamine sometimes induces an augmentation in susceptibility, i.e., a reverse tolerance, to the stimulant drug effect in animals, the circadian variation in susceptibility to the ambulation-increasing effect of methamphetamine after repeated administration was investigated in mice. The ambulatory activity of each mouse was measured by a tilting-type round activity cage of 25 cm in diameter. Mice, which had been housed under a 12 hr light-dark schedule (light period; 6:00-18:00) for 5 weeks, were administered methamphetamine 1 or 2 mg/kg SC at one of 6 times of day (3:00, 7:00, 11:00, 15:00, 19:00 and 23:00) for 5 times at intervals of 7 days, and their ambulatory activities were measured for 3 hr after each administration. The repeated administration of methamphetamine induced a reverse tolerance to the ambulation-increasing effect of the drug, and the mean overall ambulatory activity counts on the 5th session were estimated to be 2-4 times as high as the corresponding activity counts on the 1st session. However, the circadian variation in susceptibility, which was at maximum during the late dark period (administration at 3:00) and at minimum during the late light period (administration at 15:00), was well maintained even after the repeated administration. When the time of day of the drug administration were changed by 12 hr on the 6th session, a marked increase in the activity counts was observed in the mice changed from 15:00 to 3:00, while a marked decrease was observed in the mice changed from 3:00 to 15:00.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Selective suppression of schedule-induced ethanol drinking by antialcoholic drugs in rats.

Effects of disulfiram and calcium cyanamide, antialcoholic drugs, on schedule-induced ethanol drinking as well as on schedule-controlled response (lever-pressing) under a fixed interval 1 min schedule of food reinforcement were investigated in Wistar strain rats. When ethanol solution was available, the schedule-induced ethanol drinking decreased depending on the ethanol concentration (2-8%). However, the dose of ethanol intake during the 1 hr experimental session was at maximum (2.8 g/kg) when 4% ethanol solution was available. Thereafter, 4% ethanol solution was used in the experiment for studying the effects of disulfiram and calcium cyanamide on the schedule-induced ethanol drinking. Disulfiram (100-200 mg/kg, p.o.), pretreated at 1 hr before the start of the experiment, tended to suppress schedule-induced water drinking. However, the same treatment of calcium cyanamide (5-10 mg/kg, p.o.) did not produce a marked change in it. In contrast, disulfiram (100 and 200 mg/kg) and calcium cyanamide (5 and 10 mg/kg) markedly suppressed schedule-induced ethanol drinking without eliciting a marked change in schedule-controlled response. The present results suggest that both disulfiram and calcium cyanamide selectively suppress ethanol drinking in rats.

Alcohol Deterrents↗
PubMed1984

Parallelism between avoidance-suppressing and prolactin-increasing effects of antipsychotic drugs in rats.

Temporal changes in the avoidance responses and serum prolactin levels were investigated for a 360 min period after s.c. administration of antipsychotic drugs such as chlorpromazine (2 mg/kg), prochlorperazine (2 mg/kg), haloperidol (0.035 mg/kg), droperidol (0.03 mg/kg), YM-09151-2 (0.005 mg/kg) and sulpiride (80 mg/kg) in rats. Male adult rats of the Wistar strain were trained under a continuous lever-press avoidance schedule (Sidman type) to observe avoidance-suppressing effects of the drugs. The avoidance response was suppressed after administration of chlorpromazine, prochlorperazine, haloperidol, droperidol and YM-09151-2, showing significant decrease in response rate and significant increase in shock rate when compared with those after saline administration, while it was scarcely suppressed within 150 min after sulpiride. On the other hand, serum prolactin levels were increased after administration of all the drugs used. Furthermore, parallelism between temporal changes in the avoidance responses and those in serum prolactin levels was observed after administration of the antipsychotic drugs, except for sulpiride. These results suggest that the prolactin-increasing effects of antipsychotic drugs are applicable for predicting antipsychotic efficacies in humans, excluding sulpiride therapy.

Animals↗
PubMed1984

[Indications of extracorporeal surgery (autotransplantation) for upper urinary tumors and renal calculi].

Renal preservation and cure of bilateral occurrence of renal tumors or stones as well as occurrence in solitary kidney put all urologists on the thorns of dilemma. Application of extracorporeal surgery resulting in autotransplantation of the kidney for such complicated cases seems useful. Case 1 was a bilateral renal Wilms' tumors in a 17-month-old boy, case 2 and 3 were undiagnosed tumors in renal pelvis and ureter. Extracorporeal surgery enables an accurate partial nephrectomy and yet helps to avoid not only the dissemination of tumor cells, but also undesired nephrectomy in case of benign origin. On the contrary, bilateral nephrectomy followed by dialysis or homo-transplantation will result in an immunosuppressive state and the radicality may only be temporary. Besides, the 5-year survival of dialysis therapy is in the range of 60-65%. Thus the indication of autotransplantation was signified in the tumor situation of case 1. For the 2nd and 3rd cases, this method seems to be the best in satisfying the dilemma in discussion. Likewise, the complicated renal calculi could be completely removed without further deterioration of renal function if they were extracorporeally treated and autotransplanted. We proved that 83% of the difficult stones can be completely removed under hypothermia in situ. For application of autotransplantation to the calculous disease, we feel observation of contraindication is essential for better results at this stage.

Adult↗
PubMed1984

[Two cases of renal arteriovenous fistula treated by transcatheter embolization with absolute ethanol].

Two cases of renal arteriovenous fistula were treated by transcatheter embolization using absolute ethanol. These were the first cases using absolute ethanol in Japan. The first case was of a 23-year-old male and the other case was of an 18-year-old female. Both patients were admitted to our hospital because of gross hematuria. A selective right renal arteriogram showed an arteriovenous fistula. Hemostasis was obtained by transcatheter embolization using absolute ethanol. The safety and efficacy of injection of ethanol compared with other solid materials and occlusive balloon catheter are reported and its indication for renal arteriovenous fistula is described.

Adult↗