Nagoya Journal of Medical Science

In many vertebrate species, polyploid and binucleate cells are found in the adult hepatic parenchyma. The number of polyploid and binucleate hepatic cells increases with age. In this paper, the proliferative capacity of polyploid and binucleate cells were studied, in order to analyse a progressive reduction with age in the regenerative capacity of tissues. Three groups of rats, 4-week, 6-week and 15-week-old, were used in this experiment. The animals were partially hepatectomized, received an injection of tritiated-thymidine at 18 hours after the operation, and were sacrificed 30 minutes later. The livers were then subjected to the combined autoradiographic and microspectrophotometric studies. The labeling index was calculated for each hepatic cell type, which was classified according to nuclear polyploidy and binuclearity. Spatial distribution of polyploid cells in the liver lobule and that of hepatic cells labeled with tritiated-thymidine were also studied, and were taken into consideration to interpret values of the labeling index. The results of these studies indicate that value of the labeling index of polyploid hepatic cells is generally smaller than that of diploid cells, and that value of the labeling index of binucleate cells is also smaller than that of mononucleate cells. These results strongly suggest that the proliferative capacity of hepatic cells is reduced with polyploidization.

This work was performed to know the function of the muscle spindle as the transducer under various temperatures. In this field not so many have been reported except for studies made by Matthews and by Ottoson. In this report the effect of various temperatures on the so-called dynamic and static indices by Matthews et al. and on the generator potential was studied in the muscle spindle of frog sartorius muscle. The results are summarized as follows; the generator potential remained almost unchanged in the broad range of temperature and the dynamic tension was found to have the tight relation with dynamic/static index ratio.

The ratio of nutrients which might impair carbohydrate metabolism was studied using male albino rats fed with various kind of diet.
It was clarified that both the increased ratio of fat and the decreased ratio of carbohydrate+protein in the total calory consumed were the important dietary factor for the impairment of carbohydrate metabolism. The importance of this dietary ratio was discussed.

Plasma renin activity was determined in normotensive and hypertensive human subjects by a modification of the method of Boucher and co-workers. Simultaneous determination of plasma volume, serum electrolyte concentration and plasma renin activity was performed. The plasma renin activity was normal in essential hypertension and in pheochromocytoma, normal or subnormal in Cushing's syndrome with adrenal hyperplasia, increased in Cushing's syndrome with adrenal carcinoma and in renal or renovascular hypertension and decreased in primary aldosteronism. Three hours after taking upright posture, patients with essential hypertension showed two to fivefold increase of plasma renin activity, while those with primary aldosteronism did not. In renovascular hyper- tension and primary aldosteronism, plasma renin activity returned to normal range after operation. Diurnal variation of plasma renin activity was investigated under a standard condition. In normotensive subjects, highest value was observed in the forenoon and lowest value in the afternoon. As respects the diurnal varia- tion of plasma renin activity, an inverse relationship between plasma renin activity and plasma volume was exhibited.

The unilateral involvement of all or nearly all of the cranial nerves, associated with various conditions, was first described by Garcin in 1926. Different conditions such as tumors or inflammations are known to be causes of this syndrome. The primary carcinoma of the middle ear is one of causes of the syndrome of Garcin. In Japan, we have had no report of this syndrome caused by the tumors of the middle ear. A 54-year-old right-handed male with this syndrome who began to complain of an occlusive feeling in the right ear in August, 1966 and ultimately developed nearly total unilateral involvement of the cranial nerves on the right side was written. There was no evidence of increased intracranial pressure, and the X-ray film of the basal view showed invasion of the tumor. Typical findings of Garcin's syndrome were emphasized in this report.

The complicated features of congenital arteriovenous fistulas have emphasized the necessity for further study of collateral circulation to be developed around the fistulas.
Influence of an arteriovenous fistula on the collateral circulation and on the distal circulation in the involved extremity was investigated by means of angiography, electromagnetic flow meter, and venous occlusive plethysmography, in dogs with an experimental arteriovenous fistula created by side-to-side anastomosis between the femoral artery and vein. The results showed that the collateral development is rapid, requiring only one week to be significant. The distal circulation is reduced early in the postoperative period but later tends to be restored rapidly and sufficiently to 80%' of the normal value concurrently with development of collateral arteries.
When an arteriovenous fistula is constructed just distal to the femoral arterial occlusion, the development of collateral arteries is more rapid and effective for the distal circulation than in the limb with arterial occulsion only. The dilated arteries of collateral pathways remain effective after closure of the fistula. The beneficial and detrimental effects of arteriovenous fistulas on the devascuJarized limb were discussed.