[Quantitative measurement of the basilar arterial flow in the dog-electromagnetic flow-meter study of the extra-and intracranial arterial occlusion (author's transl)]

Recent advances in microneurosurgery have markedly improved the result of surgical treatment of aneurysm and arteriovenous malformation in the posterior cranial fossa. However, more precise study on hemodynamics of the vertebro-basilar system may be necessary for further progress in treatment of the vascular lesions. From this point of view, the authors studied the basilar arterial flow of the dog by means of an electromagnetic flow-meter and the flow probe which was specially devised by the authors. (1) The ratio of absolute value of the mean basilar flow to the total brain weight was calculated, and the flow rate was expressed in ml/100 g brain/min. Mean value was 7.1 ml/100 g brain/min under normocapnea. (2) The effect of occlusion of the common carotid, of the external carotid, of the intracranial internal carotid, and of the extracranial internal carotid on the basilar flow was less remarkable in this order. (3) Under normocapnea, occlusion of the unilateral common carotid artery produced 115% increase in the basilar arterial flow. Bilateral common carotid occlusion resulted in 312% increase of the flow, demonstrating a remarkable ability of compensation of the basilar artery through the circle of Willis and leptomeningeal anastomoses. Under hypercapnea, unilateral common carotid occlusion was followed by 81% increase in the basillar flow. Occlusion of both common carotids caused 230% increase in the basilar flow. Percent increase in the basilar flow after unilateral or bilateral common carotid occlusion under normocapnea was significantly larger than under hypercapnea (p less than 0.05 and p less than 0.01 respectively). It may be supposed that under normacapnea the increased basilar flow following bilateral common carotid occlusion may compensate the decrease in total cerebral blood flow due to carotid occlusion. However, the compensatory rise in the basilar flow under hypercapnea may be not enough to supply the dilated vascular bed in the carotid and basilar territories. There might be even a risk of deficiency of blood supply in the territory of the basilar artery, if the vascular resistance in the carotid area could become less than that in the basilar. The significance of CO2 inhalation therapy for ischemic cerebral lesion was discussed. (4) After the both common carotid arteries were occluded, the basilar aretry was clamped temporarily. Following release of basilar occlusion, reactive hyperemia was observed in the basilar flow. Magnitude and duration of the reactive hyperemia increased progressively depending on duration of the basilar occlusion to some extent. The phenomenon may be best explained by a progressive accumulation of vasodilating metabolities in the ischemic area. (5) Unilateral vertebral occlusion caused 37% decrease in the basilar flow. Bilateral vertebral occlusion resulted in reverse of the basilar flow, averaging 61% of the original value in flow rate. (6) Occlusion of the unilateral subclavian artery produced "subclavian steal phenomenon"...

Neuromuscular blocking properties of some antibiotics in man

Neuromuscular blocking properties of ribostamycin (1 gm), dibecacin (100 mg) and tobramycin (60 mg) were studied in a man during anesthesia and surgery by observing the effects of these antibiotics on muscle twitch tension. These drugs alone did not show any neuromuscular blocking action in those therapeutic doses. However, during the recovery phase of d-tubocurarine block the intravenous administration of 1 gm of ribostamycin caused a fairly rapid decrease in twitch tension. Tobramycin 60 mg did not show any remarkable effect, but dibecacin 100 mg produced a slight potentiating effect on the action of d-tubocurarine. The enhancement of the action of d-tubocurarine was antagonized promptly by edrophonium and more slowly by calcium.

[Neurogenic hypernatremia caused by a teratoma on the supraoptic region (author's transl)]

This is a case report involving a 9 year old girl with a teratoma that infaced mainly the bilateral hypothalamus. The girl was observed for 14 months after partial surgical removal. During that time she showed aphagia, adipsia, hypopituitarism, and visual and psychiatric disturbances. Severe hypernatremia also was present, even though large amounts of 5% glucose solution without salt were given I.V. Food and water were given by nasal gastric gavage and later gavage via gastric fistula, but the hypernatremia remained unchanged. When pitressin or spironolacton (anti-aldosterone) were administered, remarkable effect on the hypernatremia couldn't be found. Upon autopsy it was discovered that the bilateral hypothalamus, left subthalamus and ventral part of the thalamus were invaded by teratoma. Comparing many similar clinical reports and manifestations of hypothalamic lesions in experimental animals, it is reasonable to assume that the mechanisms of hypernatremia were caused by the disturbances of ADH secretion, thirst centre and osmoreceptor in the hypothalamus.

[Electric thrombosis of the experimental aneurysm--effect of alteration in intraaneurysmal hemodynamics on thrombus formation and progress of thrombosis (author's transl)]

Electric thrombosis may be one of useful method to provide protection against re-bleeding from the intracranial aneurysm which cannot be obliterated by clipping or ligation of its neck without disturbing arterial circulation. However, a better method is required to make the aneurysm to be almost completely thrombosed within one or two hours and to avoide marked damage of its wall, dislodging of the formed thrombus and excessive thrombosis. In this report a method of electric thrombosis of the experimental aneurysm was studied, and effects of hematocrit value and alteration in intraaneurysmal hemodynamics on thrombus formation and progression of thrombosis were investigated. An aneurysm-like vein pouch of 6 to 9 mm in diameter and of 5 to 8 mm in height was made on the common carotid artery of the dog. One week later, patency of the "aneurysm" was confirmed on angiogram. An anodal electrode of a platinum needle of 0.2 mm in diameter was inserted into the "aneurysm" to place the tip of the needle approximately at the center of the sack. Two platinum plates of 3 mm in diameter and of 0.1 mm in thickness were used as the cathodes and were placed externnally on the aneurysm wall. Direct current of 3 mA was applied for 5 or 10 minutes, or current of 5 mA for 5 minutes. Intraaneurysmal pulsating jet and turbulent flows were reduced by occlusion or stenosis of the common carotid. Size of the thrombus immediately after passing current and further progress of thrombosis were evaluated on angiogram and also on plethysmogram of the "aneurysm". Hematocrit value of 45% or more was favorable in producing a thrombus. Although direct current of 3 or 5 mA was desirable to avoid injury of the "aneurysm" wall and to inhibit dislodging of the formed thrombus, only a small thrombus was produced around the anode. Simultaneous occlusion or stenosis of the carotid artery proximally to the "aneurysm" during application of the current markedly promoted thrombus formation. With current application for 5 minutes, 30 to 40% or more of "aneurysm" lumen was occupied by the thrombus in a half of the cases. When the thrombus had reached to approximately 40% of aneurysm "sack" 5 minutes after passing DC current, it progressed to 80% within the following one hour. The most favorable site of the anode for progression of thrombosis was the proximal wall (cardiac side) of "aneurysm". Proximal occlusion or stenosis of the carotid artery promoted remarkably also progress of thrombosis. Excessive thrombosis, dislodging or spontaneous resolution of the formed thrombus was not found throughout one month follow-up. Histologically, the thrombus was organized within one month and covered with the endothel extending from the parent artery.

[Giant anterior communicating artery aneurysm (author's transl)]

A case of giant aneurysm arising from the anterior communicating artery, 24 X 28 X 30 mm in diameter was found in a 30 year old man. About ten years ago he became blind and recently developed right anosmia and diencephalic seizures. No subarachnoid hemorrhage, however, was found. Radiograms and tomograms of the cranium showed a ring-like calcification, but by angiography it couldn't be recognized as a giant aneurysm. The right frontal craniotomy and partial resection, therefore, was performed. A histological study of the resected material revealed that it was a spontaneously thrombosed giant aneurysm. The inner layer of its wall had neither endothelium nor elastic lamina, but had deposits of calcium salt. The outer layer was composed of collagen fibers without cell infiltration. The aneurysm was thrombosed except for its neck but its organization occurred incompletely. We want to emphasize the importance of a correct preoperative diagnosis, as an erroneous operative procedure can result in disaster. Volume, viscosity and tension of flowing blood into the aneurysm as well as the size of its neck and dome regulate dynamic properties. These properties may determine the enlargement rate or growth of the aneurysm. The dynamic characteristics and features of the inner surface of the aneurysmal wall may regulate the formation of thrombosis in the aneurysm. The intraluminal thrombosis and strength of aneurysmal wall, for example, calcium deposits, may prohibit aneurysm from its rupture.

Mast cells in the epidermis of piebaldism

The depigmented lesion in a case of piebaldism (partial albinism) was examined by electron microscopy. In the epidermis melanocytes were absent and the number of Langerhans cells was increased. In addition several mast cells were found in the epidermis.