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Biomedical subjects

T Sakata

Publications and source records attributed to T Sakata.

At least 577 records · Page 32Linked to original sources
PubMed1975

[Characteristics of aggressive behavior induced by chronic administration of theophylline in rats].

In previous studies we reported that chronic administration of theophylline induced affective aggressive behavior in rats. The present study was designed to clarify characteristics of the aggressive behavior observed, and compare it with that in the olfactory bulbectomized and isolated rats. To measure aggressive behavior, the reflexive fighting test, the test for killing response to various objects and the aggressiveness rating test were used, and in addition, the open field test was employed to objectively measure emotionality. It was only the theophyllinized rats that assumed the fighting position not only during the electric shock period but also during the adaptation and sound shock periods. The theophyllinized pairs fought quicker and more frequently than did the other treated pairs. During a 3 min observation the percentage of mouse-killers was much higher among the theophyllinized group (62.5%) than among the other treated groups (the olfactory bulbectomized and the isolated groups increased mouse killing to 87.8% and 62.5%, respectively, though the theophyllinized group remained at 62.5%. The theophyllinized killers attacked constantly rat-pups and dead as well as live mice. In the open field test, rearing and ambulatory activities increased more in the olfactory bulbectomized group and decreased more in the isolated group than in controls, but no change was observed in the theophyllinized group. Defecation which has a negative correlation with aggressiveness decreased more only in the theophyllinized group than in the controls. Prior to treatment there was a positive correlation between the frequency of ambulation and that of rearing (r = 0.535, n=32, p less than 0.01).

Aggression↗
PubMed1969

Hyperphagia and polydipsia in socially isolated rhesus monkeys.

Three rhesus monkeys which had been isolated from social contact during their first year of life persistently overate and overdrank during adulthood. These monkeys ingested approximately twice as much fluid and food as the control animals reared normally.

Animals↗
PubMedDate not supplied

Histaminergic control of energy balance in rats.

Manipulating neuronal histamine in the hypothalamus, its effects on brain functions were assessed in nonobese normal rats and Zucker rats. Alpha-fluoromethylhistidine (FMH), an inhibitor of histamine synthesis, induced feeding dose-dependently after 2.24 mumol infusion at 1100 h, when hypothalamic histamine was normally high. This dose of FMH selectively decreased hypothalamic histamine, but not other neurotransmitters. Thioperamide, an antagonist of autoinhibitory H3-receptors, decreased food intake after infusion at 1940 h, when hypothalamic histamine was normally low. Bilateral microinfusion of 224 nmol FMH or 26 nmol chlorpheniramine, an H1-antagonist, into the ventromedial hypothalamus (VMH) and the paraventricular nucleus (PVN), elicited feeding. However, Zucker obese rats showed no significant responses to chlorpheniramine, thioperamide or histamine. Concentration of their hypothalamic histamine was excessively lower than that of the nonobese. Contents of hypothalamic histamine were lowered at 4 degrees C and raised at 31 degrees C. FMH attenuated increase in histamine, and then disrupted adaptive behavior. These findings indicate that neuronal histamine may convey the suppressive signal of food intake through H1-receptors in the VMH and/or the PVN, and play critical roles in homeostatic control of adaptive behavior.

Adaptation, Physiological↗
PubMedDate not supplied

Prevention of summer-type hypersensitivity pneumonitis: effect of elimination of Trichosporon cutaneum from the patients' homes.

To prevent summer-type hypersensitivity pneumonitis, the effect of eliminating Trichosporon cutaneum from patients' homes was investigated. To determine environmental factors associated with enhanced indoor mold growth, we compared 11 patients' homes in which T. cutaneum was isolated to 32 control homes by inspection and indoor mold survey. Statistically significantly higher isolates of T. cutaneum, total yeasts, and total fungi were associated with unsanitary rooms, and especially with damp places in the wood or tatami mats in patients' homes. Cleaning, disinfecting, and removing the colonizing locations of T. cutaneum were performed. No recurrence was observed in 6 well-cleaned homes, but recurrence was observed in all patients who resided in homes that were not cleaned or in homes where cleaning was not adequate, and where T. cutaneum was not eliminated. The efficacy of therapy by elimination of T. cutaneum was proven.

Alveolitis, Extrinsic Allergic↗
PubMedDate not supplied

Hypersensitivity pneumonitis of a mushroom worker due to Aspergillus glaucus.

We present the first reported case of hypersensitivity pneumonitis (HP) due to Aspergillus glaucus in a mushroom worker. The Aspergillus glaucus group is one of the most popular storage fungi and a possible subsidiary etiologic agent of farmer's lung, but no case of hypersensitivity pneumonitis (HP) due to A. glaucus has been reported. This first case may demonstrate the etiologic role of A. glaucus in HP and in farmer's lung.

Adult↗