Onset of dynamic activity in globally coupled excitable and oscillatory units.

The onset of dynamic activity is studied in heterogeneous populations of globally coupled units such that each unit is either excitable or oscillatory depending on its parameter. By varying the mean of the parameter distribution as well as coupling strength, we show that all or part of the populations studied have common features: similar phase diagrams, hysteresis near or at the onset of dynamic activity, and a fractional power law obeyed by an order parameter. A simplified model is proposed to explain these results.

[The effect of preoperative epidural morphine on postoperative pain].

Postoperative analgesia was assessed by examining nurses' records of 421 gynecological operative cases between January, 1989 and November, 1990. The criterion used in the analysis was the need for analgesics for pain within 24 hours postoperatively. After receiving morphine (2 mg, 4 mg, 5 mg, 6 mg) with local anesthetics or physiological saline solution into the epidural space (lower thoracic, lower lumbar, or both regions), the patient was intubated with thiopental, diazepam, and a muscle relaxant (vecuronium or pancuronium).

Safety of ablation of the sigmoid and transverse sinuses: an experimental study.

If the sigmoid and transverse sinuses could be divided safely, surgeons could broaden their access during skull base surgery without retracting the brain extensively. We undertook this study in monkeys to assess the risk of sacrificing these sinuses. We learned that when bilateral transverse sinuses were occluded, the sinus pressure measured in the superior sagittal sinus increased significantly as blood was purged from sinus venules.

[A successful treatment of spontaneous carotid cavernous fistula causing hemorrhagic infarction treated by detachable balloon].

A rare case of hemorrhagic infarction associated with carotid-cavernous fistula is reported. The patient was a 74-year-old female. CT scan showed hemorrhagic infarction of the left superior temporal gyrus, irregular vascular enhancement of the bilateral front-temporal lobe, and dilatation of the cavernous sinus.

[A simple method of extracorporeal membrane oxygenation (ECMO)--3. The effects of pumpless ECMO (arterio-venous shunt) on arterial blood gas measured for 24 hours].

In eight anesthetized mongrel dogs, the pumpless ECMO applied between the femoral artery and vein was performed under the condition of hypoventilation for 24 hours. The methods were same as the first and second reports, except the pumpless ECMO was used. The abnormal parameters in the cardiovascular and respiratory system (blood gas analysis and end expiratory gas analysis), induced by hypoventilation, recovered to almost normal ranges, by operation of the pumpless ECMO for 24 hours.

[Treatment of vegetative status with dorsum column stimulation].

Unlabelled: We have already reported that DCS (Dorsum Column Stimulation) alleviates the clinical symptoms of patients in vegetative status. Since then, we have accumulated information about 23 cases that have been treated by DCS therapy. In this paper, we describe the clinical outcome and compare cases where the treatment was effective with those where it was non-effective to evaluate the indications for further use of this treatment.

[A simple method of extracorporeal membrane oxygenation (ECMO)--2: The effects of ECMO (arterio-venous shunt) on the arterial blood gases measured for 24 hours].

In eight anesthetized mongrel dogs with thiopental, diazepam and pancuronium bromide, ECMO with arterio-venous shunt was performed under hypoventilation for 24 hours. The blood flow through the ECMO which was connected between the femoral artery and vein was approximately 40% of the cardiac output. Hypoventilation was induced to decrease PaO2 to around 40mmHg and increase PaCO2 to around 80 mmHg.

A pitfall in the interhemispheric translamina terminalis approach for the removal of a craniopharyngioma. Significance of preserving draining veins. Part II. Experimental study.

The authors have reported a case of a craniopharyngioma removed by the interhemispheric translamina terminalis approach, and the postoperative development of a subcortical hematoma. We suspected that the cause of the subcortical hematoma was dividing the bridging veins and applying a retractor over them. In this paper, we report our experimental study, using dogs and monkeys, to evaluate the effect of cutting the vein and applying a retractor over it.

A pitfall in the interhemispheric translamina terminalis approach for the removal of a craniopharyngioma. Significance of preserving draining veins. Part I. Clinical study.

The interhemispheric translamina terminalis approach has made total removal of a craniopharyngioma less risky. Nevertheless, one of the pitfalls of this approach is cutting of the draining veins combined with retraction. A case of craniopharyngioma in which a subcortical hematoma developed is reported.

Enkephalin degrading enzymes in cerebrospinal fluid.

Enkephalins were rapidly degraded by specific enzyme systems in vivo. In cerebrospinal fluid (CSF), however, it has been undefined whether these enzyme systems existed. Our experiments showed enkephalins were hydrolyzed by the enzymatic activity in both CSF of human and monkey.

Droperidol, its alpha-adrenergic blocking action on the aortic strip and inhibitory action on norepinephrine uptake of the adrenergic terminal of the left atrial strip of rabbit.

In aortic strips, the dose-response curves for phenylephrine were obtained before and after addition of droperidol. Droperidol caused a parallel shift of the curves dose-dependently toward the right side and its grade of the shift was greater than caused by phentolamine at the same concentration. In the left atrial strip, the potentiation of contraction by tyramine was markedly depressed by droperidol.