Six representative strains of staphylococci were selected on the basis of DNase activity and inoculated into the mice to study the correlation of the presence of this enzyme to the virulence of the staphylococci. Two strains of staphylococci among them produced DNase but not the free coagulase, and one of these two strains had an obvious virulence against the mice. The results of experiments suggest that there are at least certain strains which may be designated as Staphylococcus aureus among these DNase-producing staphylococci producing no free coagulase. This is an additional evidence that this enzyme activity should be adopted as a criterion to distinguish from the other S. aureus which has lost the free coagulase activity. In this sense, the staphylococci producing neither free coagulase nor DNase are after all Staphylococcus epidermidis, regardless of their ability to ferment mannitol or not.
The renal microvasculature evidenced by intraarterial injection of silicone rubber performed in 10 cases of acute renal failure from various causes demonstrated definite reduction in filling with patchy deficit in subcapsular cortex, narrowing of preglomerular arterioles, especially at the branching from the interlobular arteries in the same area, relative increase in filling of vas afferens and efferens of juxtamedullary cortex, and of vasa recta in medulla. The same injection figures are observed in acute renal failure in dogs experimentally induced by ligation and clamping of renal arteries, and intraarterial infusion of large quantities of angiotensin II (1000 ng/kg/min). Although the etiological factors of acute renal failure are manifold and the parenchymal damage is varied as well, the vasoconstriction of preglomerular arterioles should be considered as an initial common pathway which continues in subcapsular cortex. The result of present experiments is consistent with the hypothesis that renin and angiotensin participate in the pathogenesis of acute renal failure.
Ultrastructural changes of the sciatic nerves of C57BL/ 6J dydy mice were examined. Nerve counts were calculated and the area of axons was measured in these nerve tissues. Many large bundles of unmyelinated nerves were observed at the proximal portion of the sciatic nerve, without cytoplasm or basement membrane of the Schwann cell. These bundles were composed of axons of various sizes and shapes, including some very large axons. The large unmyelinated axons decreased in number and size as nerves descended to the distal portion. The myelinated nerves showed irregular shapes. Some myelinated nerves were enveloped in very thin myelin sheaths for the mouse age. The destructed myelin was often observed from the radix to the distal portion of sciatic nerves. They lost their myelin sheaths at the Ranvier node, and descended for long distances with naked axons. The neighboring myelin segments of naked axons showed unusually bizarre shapes. They seemed to be the abnormal development of the demyelinated axons. Such findings were very similar to those of the embryonal developing peripheral nerves. It was concluded that the muscular dystrophy of the C57BL/6J-dydy mice might be related to dysmyelination and to the decrease in the number of myelinated nerves.
The authors report on a case of epidermoid tumor in the lateral cerebral ventricle. Epidermoid tumors are relatively uncommon intracranial lesions and were first described by Esmarch. Till now about 300 cases have been reported. In Japan this tumor was first described by Yamamura, and since then many cases have been reported. But the one situated in the lateral ventricle has not been reported yet in this country. The significance of echo-encephalography is discussed because this procedure was very useful in determining the location and the nature of the tumor of this case.
By using the swan-type double-bending gastrofiberscope, it has become very easy to observe such regions as the cardia, posterior wall of the upper corpus or the pyloric region. The authors can obtain a clear image of the cardia, especially the form of the folds of the region or the esophagogastric junction. The authors recognized that the form changes according to the amount of the inflated air, and the insufficient function of the cardia can be easily diagnosed. The degree and form of the elevation of the posterior wall of the upper corpus of the stomach was observed and classified into three types, flat type, slightly elevated type and highly elevated type. Pathological deformation of this region was studied from the shape of this elevation. By the close observation of the pyloric region, it was clarified that the appearance of the folds may be radiated, transverse at the lesser curvature or entirely lost, being closely related to the presence of the erosions in this region. The healing process of the gastric ulcer was examined endoscopically from the viewpoint of the radiating vessel zone and contraction by the scar. When the capillary vessels are the more prominent finding of a healing ulcer, it tends to form a surface possessing a car after it is healed and when the contraction is more prominent, it tends to form a linear scar after healing. By the recrudescence of the gastric ulcer, the irregular capillary vessels or deviation of the convergence of the folds are observed, and by the recurrence of the ulcer, coexistence or complication of a scar is observed.
The elimination rate of COHb in the blood was measured by a tonometer and the COHb saturation of the human blood under the exposure of 0.3% CO in the air for 30 minutes was estimated to be about 47%. The CO elimination of the tonometered blood by the exposure to 4 kinds of gases, 1 ATA air, 1 ATA O₂, 1.9 ATA O₂ and 2.8 ATA O₂, showed a linear decrease on the semi-logarithmic figure, and the gradient coefficient (k) of the straight lines showed a good reproducibility and significant difference from each other. The COHb elimination after supplying a 0.3% CO air mixture for 20 minutes tO₂3 mongrel male dogs weighing 12 to 18 kg were observed by letting them breathe 1 ATA air for 300 minutes, 1 ATA O₂ for 120 minutes, 1.9 ATA O₂ for 60 minutes and 2.8 ATA O₂ for 30 minutes. The COHb decrease of the CO-poisoned dogs showed also a semi-logarithmically linear tendency and the gradient coefficient (k) among these four gas-breathing groups showed a significant difference. The mean half-clearance time (t/2) of each group was: 1 ATA air for 188 minutes, 1 ATA O₂ for 32 minutes, 1.9 ATA O₂ for 25 minutes and 2.8 ATA O₂ for 12 minutes. The higher the O₂ partial pressure in the inspired gas increased, the greater became the decrease of the COHb clearance time and the greater became the reducting of the half-clearance time. The CO elimination by the dogs at a high PO₂, on the contrary, an opposite relation was observed. This fact may be explained by the improvement of the ventilatory and circulatory functions of the alveoli concerned with the CO elimination at a high PO₂, but at a low PO₂ the alveolar functions are impaired by CO and the O₂ supply is insufficient to cover the dysfunction, so the CO elimination is larger in the tonometered blood than in the dog blood. The procedure of OHP for CO poisoning was designed by the CO elimination rate in the dog, assuming it to be the same as that in the human, for the patients of three levels of severity of CO poisoning: Phase I is breathing of 2.8 ATA O₂ for 20 minutes, usually for the patients of each level of severity, then Phase II (breathing of 1.9 ATA O₂) follows after that for severe poisoning (COHb in the blood, 80%) for 57 minutes, for medium poisoning (COHb, 60%) for 46 minutes and for light poisoning (COHb, 40%) for 32 minutes. After the treatment of Phase II, the blood COHb content decreases to 5%, a safety level for CO poisoning. This process is practical and effective for the OHP treatment of CO poisoning, and besides it is not only safe against O₂ poisoning but also is capable of supplying rapidly sufficient amount of oxygen to improve the condition of the anoxic tissues.
To investigate the effect of the radiant heat on the human body in a hot environment, the subjects exposed their nude back to a radiant heat of 1.3 and 2.6 cal/ cm2. min, using the exsiccating infrared illuminators under a hot ambient condition of a temperature 31℃, with a relative humidity of 55% and a 0.5 m/sec air flow. The 8 subjects were healthy male college students aged 20 to 25. The following results were obtained by estimating the physiological reactions to different degrees of radiant heat at rest for 60 minutes and during exercise for 30 minutes on a bicycle e1gomete1·by 272 kg. m / min (or 600 kp. m/ min). 1) The mean skin temperature, heart rate, respiration rate and body weight loss r ate increased at rest in parallel with the degree of the radiant heat, and during exercise the mean skin temperature, heart rate, respiration rate, body weight loss rate and respiratory volume increased, but the Na+ loss rate decreased. The regression equation was obtained to show the quantitative relationship between the degree of the radiant heat and the physiological body reactions. 2) By computing the Heat Tolerance Index by Inoue et al., it was clarified that the higher the degree of the radiant heat was, the smaller was the index. And as there was a close correlation between the indices both at rest and during exercise, it was suggested that for the evaluation of heat tolerance, the radiant heat by the infra1ed illuminators is applicable as additional heat loading besides hot water bathing or staying in a hot chamber.
Auto-immunization treatment of carcinogen-fed rats using homogenates of carcinogen induced tumors did not have any adverse effect on new tumor formation and growth as well as local recurrences. Auto-immunization treatments did not change the degree or nature of the inflammatory reaction observed in carcinogen-induced tumors. Auto-antibodies against carcinogen induced tumor tissue antigen could not be demonstrated in sera to any significant extent. However, the detection of lymphocytic infiltration of various intensity in the stroma of the tumor suggested that host definsi mechanism may involve in the course of development this authochtonous tumor.
The ordering process in gold-copper silver dental alloys was studied by means of isochronal and isothermal resistivity measurement. Because the stable existing temperature range of orthorhombic superlattice was unexpectedly extended to lower temperature by the addition of silver to gold-copper binary alloy, the ordering velocity in these alloys are considerably slower than that of binary stoichiometric AuCu alloy. Activation energy, the order of the reaction, and rate constant for growing process were established. The difference in growing mechanisms depending on gold concentration was deduced from the kinetics data.
This investigation was carried out to analyze the physical factors of saliva affecting denture retention. A model of examining denture retention is given by two parallel disks separated by a liquid layer. Metal, polyisobutylene (PIE) and poly (methyl methacrylate) (PMMA) were used instead of a denture and mucous membrane; and glycerol live oil and castor oil instead of saliva. The experiments were performed with three disk conditions: (1) Both upper and lower disks of metal, (2) both upper and lower disks of PMMA, (3) upper disk with PIB lining and lower of PMMA soley. A strain gauge was used in the experimental apparatus in order to obtain a measurement of high accuracy. In the experiments, the retentive forces developed in layers of 50µ thickness were measured and compared with the values calculated from theoretical equations. The results are summarized as follows: (1) Retentive force must be resolved into static adhesive and separating forces, (2) surface tension of liquid may not highly influence the retention, and (3) viscosity of liquid plays an important role when two disks are separated.