Nagoya Journal of Medical Science

The primary interest of the study is to investigate the spinal cord disturbance by aortic occlusion by electrophysiological means. Cats were chosen for the study and spinal reflexes and spontaneous discharge of motoneuron were electrophysiologically recorded on oscilloscope with complete occlusion of arch of aorta through the thoracotomy.
The monosynaptic reflex of spinal cord showed 3 phasic or 5 phasic changes in amplitude before disappearance, while multisynaptic reflexes acted in reversed phases.
Monosynaptic reflex decreased its amplitude when aortic occlusion was re- leased during its excited stage, while it increased when it was done before the excited stage.
Spontaneous discharge of motoneuron was also investigated, which showed direct change in efferent fibers but not in afferent fibers.
In spinal cats, spontaneous discharges of motoneuron showed no relationship to amplitude of monosynaptic reflex but parallel relationship to the multisynaptic reflex.
Negative and positive potentials of anterior horn of spinal cord reduced their amplitude by aortic occlusion, but no spike of intramedullary evoked potential were changed.
Spinal reflex and spontaneous discharge of motoneuron recover following the release of aortic occlusion, and the latter anticipates in recovery.

The present study concerns with the vascular changes of the spinal cord, when it is compressed anteriorly such as spondylotic myelopathy.
The method of spinal cord compression was explored to give the pressure only anteriorly without opening the spinal canal. The procedure is to approach anteriorly to the vertebral column and the intervertebral disc is drilled and the anterior aspect of the spinal cord is visualized without the laminectomy procedure which may act as a decompressive. Microangiographic study is made with ex· tensive injection of aqueous suspension of micro-particle of barium sulfate into arterial system of the spinal cord via the vertebral arteries. Various sections of less than 5 mm in thickness are made of the spinal cord in which the arterial system has been filled with barium. Transverse section of the spinal cord readily shows the beautiful pattern of arterial supply on the microangiogram. Parasagittal section of the spinal cord, however, is found best to demonstrate the change of vascular pattern in the case of anterior cord compression.
From the present observations, the results are summarized as follows:
1. The anterior spinal artery is difficult to be occluded by anterior pressure, so that the theories of anterior spinal artery insufficiency in the case of spondylotic myelopathy seem equivocal.
2. Parasagittal sections show early and persistent change of the central arteries by anterior pressure instead.
3. Deformity of the spinal cord could be due to tight fixation by the dentate ligaments, and this deformity could be the main cause of the central artery in- sufficiency.
Vascular changes of the spinal cord by anterior pressure were discussed in detail in regard to the pathogenesis of spondylotic myelopathy.

This report is to shew the basic study-histological follow up-of my "cyanoacrylate monomer adhesive-polyfion coated tetoron mesh technique" which was advocated and applied in our neurosurgical practice for past 6 years in over 100 clinical cases.
This technique was adapted for clinical application with fairly brief experimental works at begining, since it was known these materials were not noxious and the amount of application was so little. This technique is useful especially in neurosurgical operation such as dura substitute transplantation in the cases of head injury, complete removal of dura infiltrating brain tumors, repair of cerebrospinal fluid leakage, repair of big dural venous sinuses and wrapping procedure of intracranial aneurysms.
For the experimental investigations, 50 mongrel adult dogs were used as ex- perimental animals. The tetoron mesh was transplanted to patch the experimentally produced dural deficit and broken dural venous sinus. Grossly, this technique seems to be satisfactory for the repair of these.
Histological study of the grafts, taken after 10-180 post-operative days, reveals gradual absorption of cyanoacrylate glue and apparently the glue was phagocytosed and emigrated away as the intracellular deposit of giant cells. As the matters of fact, many cases showed no evidence or even a trace of this glue in careful dissection.
Healing process of grafted region is made without excess granulomatous tissue, but proper formation of neomembrane over the graft. Conclusively, this technique seems more preferable than any other reported procedures.

The intracranial pressure is one of the important vital signs in the field of clinical neurology and neurosurgery.
The author reports about the newly designed device which measures the intracranial pressure continuously and directly in the closed system with a pressure transducer using a semi-conductor strain gage which was developed by Igarashi of Toyota Central Research and Development Laboratories, Inc.
The pressure transducer is a small disc of 5 mm in diameter and 1.5 mm in thickness. Its output power is 0.24 mV to the pressure of 100 mmH₂O, and it is recorded after amplifying. Using the device, it is possible to measure the absolute value of intracranial pressure and to record the plethysmograph of the brain surface. The satisfactory results have been obtained in the animal as well as in clinical measurements of intracranial pressure. In clinical measurement, two kinds of plethysmograph were observed: one is the wave caused by respiration and the other is the wave caused by pulsation. The changes of these waves have important physiological significances. On the other hand, the absolute intracranial pressure also changed very quickly and largely by coughing, forced respiration, or the other changes of the condition of the measuring subject.
The author has also described that, in the near future, it will become practical to measure the intracranial pressure by telemetering using this device.

In order to elucidate the mechanism by which thyroid hormone influences the calcium metabolism, ⁴⁵Ca kinetic study and calcium, phosphorus and nitrogen balance study were carried out in 4 control subjects, 4 hyperthyroid patients, a hyperthyroid patient associated with hypoparathyroidism, 2 hypothyroid patients and 2 primary hyperparathyroid patients.
The conceptual model used to analize the kinetic data was that proposed by Heaney et al. and ⁴⁵Ca was counted by Lutwak's method, using a liquid scintillation spectrometer.
The sizes of miscible calcium pool, the turnover rates, the bone formation rates and the bone resorption rates were increased in hyperthyroid patients as much as in primary hyperparathyroid patients, while these were decreased in hypothyroid patients. Moreover, the bone resorption rates exceeded the bone formation rates in patients with hyperthyroidism as well as in patients with primary hyperparathyroidism.
Negative calcium, phosphorus and nitrogen balances were observed in hyperthyroid patients as well as in primary hyperparathyroid patients.
From these observations, it was suggested that the excessive destruction of bone is the primary event in the abnormal calcium metabolism in hyperthyroidism.

A study was carried out on the influence of oxygen at high pressure upon the experimental tumor and the host. The results were as follows;
1) From the observation of 50% survival time in the rats in which the Yoshida sarcoma had been transplanted intraperitoneally, a significant life pro- longing effect was noted in the combined treatment of Mitomycin C and oxygen at high pressure (MMC+OHP).
2) Pathological study on the long survived cases disclosed that, in the group treated with MMC+OHP combination, the tumor exudates had disappeared and the collapse of the nuclei of the Yoshida sarcoma cells in the pulmonary capil· !aries was marked.
3) Although suppression of mitotic index was noted in the group treated with OHP alone the tendency of suppression was significant in the mitotic index of the group treated with MMC+ OHP combination.
4) The effect of OHP on the reticuloendothelial function of the host was, except when its function was severely impaired, in the direction of stimulation. The optimum condition of OHP was at 3 ATA and for 30-60 minutes at 24 hours intervals.
5) The optimum condition of OHP served for shortening the mean survival time of allograft on the host. The rejective reaction was the most intense in the group treated with MMC+ OHP combination.

The total 476 sera were examined by a routine electrophoresis and further by the use of immunoelectrophoresis. 1) Among the 42 broad banded hypergamma- globulinemics, neither M-components nor a lack of a.ny class of immunoglobulin was detected. 2) Out of the 23 hypogammaglobulinemics, 3 cases of dysgamma- globulinemia were found only after the immunoelectrophoresis. 3) All of the 51 cases with a spike on the electrophoresis was proved to be a monoclonal gam- mopathy due to M-IgG in 36, M-IgA in 10, M-IgM in 3, and Bence-Jones type in 2 cases. 4) Out of the 360 cases without any detectable abnormality of electro- phoretic globulin fractions, one case with recurrent infections was found to lack IgA in the serum by the use of immunoelectrophoresis. From these data, "merits and demerits" of the two methods, i.e., routine electrophoresis and immunoelectrophoresis were discussed. Some of the interesting cases were presented and compared with reports by others.