An experimental study on pyogenic osteomyelitis with special reference to polymicrobial infections

The author used the following method to successfully devise a model of experimental osteomyelitis caused by two different bacteria. A 3-mm silk thread (No. 5) soaked in Staphylococcus aureus (1.0 X 10(4) CFU) and Pseudomonas aeruginosa (1.0 X 10(5) CFU) suspensions was dried under reduced pressure. The silk thread was inserted into the metaphysis of the right tibia of mice. Experimental osteomyelitis caused by these two species of bacteria was successfully produced in all the mice, and this infection was similar to osteomyelitis in man. After prior infection with S. aureus, P. aeruginosa (1.0 X 10(3) CFU) was inoculated directly into the tibia of mice during the acute and chronic stages of the S. aureus infection, and secondary infection by P. aeruginosa was confirmed in all the mice. Using this experimental model of osteomyelitis, the author administered an antibiotic that is effective against only S. aureus in mice and observed abrupt growth of P. aeruginosa to elucidate certain aspects of the bacterial replacement phenomena.     

Uraemic myocardial disease. An experimental study, with special reference to the effect of parathyroidectomy

A histopathological study of the myocardium was performed in rats made uraemic by a 5/6 kidney resection. The examinations were performed after intervals up to 36 weeks. Uraemia caused focal myocardial necroses, the incidence and severity of which were related to the length and severity of the uraemic state. In the myocardium of some animals intracellularly located calcifications were found. The calcifications usually appeared only in the necrotic areas. The coronary arteries showed only slight or moderate arteriosclerosis without severe obturation of the lumens and the genesis of the necroses is suggested to be factors other than ischaemia or hypoxia. Since secondary hyperparathyroidism might be one such factor, the effect of prior parathyroidectomy was studied. Parathyroidectomy prevented the development of calcifications but not the development of necrosis. However, the significance of secondary hyperparathyroidism in the development of myocardial necroses cannot be fully evaluated from the present study. The protecting effect of parathyroidectomy was probably counterbalanced by the deleterious effect of further elevated serum phosphate levels in the parathyroidectomized animals.     

烧伤后肠黏膜细胞外基质与细胞凋亡关系的实验研究

目的　探讨烧伤后大鼠肠黏膜细胞凋亡与细胞外基质的关系。　方法　 30只Wistar大鼠随机分为烧伤后 6、12h,1、3、5d组及正常对照组 ,每组 5只。检测肠黏膜上皮细胞凋亡数、cas pases 3酶活性、细胞外基质成分 (层粘连蛋白、Ⅳ型胶原 )含量 ,并作相关分析。　 结果　烧伤后大鼠肠上皮凋亡细胞数、caspases 3的活性较正常对照组明显升高 (P <0.0 5或 0 .0 1) ,大鼠肠黏膜层粘连蛋白、Ⅳ型胶原含量较正常对照组下降 ( P <0.0 5或 0 .0 1)。直线相关分析结果 :烧伤后肠黏膜层粘连蛋白、Ⅳ型胶原含量变化与细胞凋亡数呈显著的负相关 (r =- 0.5 75, - 0.6 13,P <0 0 5 )。　 结论　烧伤后大鼠肠黏膜细胞凋亡增加 ,且与细胞外基质的变化相关。     

Histological study on chemonucleolysis with special reference to the relationship between the dose of chymopapain and disc regeneration

The present study on chemonucleolysis was conducted to determine the influence of chymopapain dose level and patient age on the degree and mode of the response and regeneration of the intervertebral disc. Chymopapain at various doses was injected into the intervertebral discs of young (8-week-old) and mature (20-week-old) rabbits respectively for a histological study. In rabbits undergoing high dose injection, not only the nucleus pulposus but also the inner layer of the annulus fibrosus was digested. Regeneration hardly occurred, and only a slight amount of scar tissue appeared in many animals. At lower dose, the annulus fibrosus remained intact and the posterior inner layer of the annulus fibrosus mainly proliferated toward the anterior portion of the disc, filled the space of digested nucleus pulposus, and restored disc height. This regeneration process was not thought to be specific to the damages caused by chymopapain but rather a common response of injured intervertebral discs.     

钙蛋白酶与肝移植缺血再灌注损伤关系的实验研究

目的 探讨大鼠肝在不同冷缺血期、复温期及再灌注期钙蛋白酶活性变化，以及钙蛋白酶抑制剂对离体灌注肝功能及原位肝移植大鼠生存的影响。方法 SD大鼠。共5个实验部分：（1）冷缺血实验；（2）冷缺血后复温实验；（3）冷缺血后再灌注实验；（4）钙蛋白酶抑制剂实验；（5）原位肝移植实验。结果 冷缺血12h始，肝组织中钙蛋白酶活力明显增加，并随着冷缺血时间的延长而逐渐明显增加（P＜0.01）。冷缺血复温30min始，肝组织中钙蛋白酶活力明显增加，并随着复温时间延长而逐渐明显增加（P＜0.01）。肝组织冷缺血0和12h再灌注60min钙蛋白酶明显增加（P＜0.05）。钙蛋白酶抑制剂明显增加（P＜0.05）。而冷缺血24h再灌注30min钙蛋白酶便明显增加（P＜0.05）。钙蛋白酶抑制剂可明显地降低离体灌注肝AST水平及增加胆汁量（分别P＜0.01）。结论 肝移植冷缺血期、复温期及再灌注期钙蛋白酶均明显增高，钙蛋白酶抑制剂可明显地改善移植肝功能。     

An experimental study on the development of congenital spinal deformity--with special reference to the occurrence and significance of disc anomaly]

This is a histopathological study in mice, using the tail segment of the vertebral column, to investigate the role of intervertebral disc anomalies in the development of congenital spinal deformities. The study was conducted on 222 embryos and 169 postnatal CTT (Crooked-Tailed Toden) mice, a ddY strain with hereditary crooked tails. The earliest detectable anomaly was a serpiginous deformation of the notochord during the notochord stage. Irregular lamination of dense and sparse cell layers of the sclerotome during the membrane stage followed. Then vertebral body and intervertebral disc anomalies clustered around the abnormal notochord, failing to appear separately during the cartilage stage. It was concluded that anomalies of the vertebral body do not appear independently but occur simultaneously with those of the intervertebral disc in the development of congenital spinal deformities. Disc and vertebral body anomalies appear to have equal significance in the pathogenesis of congenital spinal deformities.     

An experimental study on the mechanism of rectosphincteric reflex in special reference to Hirschsprung's disease

In order to clarify the mechanism of rectosphincteric reflex (RSR), an experimental study was performed using mongrel canine models. The RSR exists in normal anesthetized mongrel dogs. It does not disappear in dogs with isolation of the rectoanal portion from the surrounding tissues. The RSR disappeared after circular transection of the rectal muscle coat at the level between the rectum and the anal canal, and also after selective destruction of the myenteric plexus of the rectum. These data suggest that the RSR is a local reflex contained within the rectoanal wall and its regulating center and neural pathway are in the myenteric plexus of the rectum.     

A manometric study of anorectal function after surgery for anal fistula, with special reference to incontinence

Anorectal function was manometrically studied in 199 adults on average 9 years after laying open of anal fistula, in order to determine the factors adversely affecting anal continence. Resting anal pressure, and especially squeeze and voluntary contraction pressures, were significantly reduced in the 67 patients with defective anal control. Maximal squeeze and contractile pressures were significantly lower in women than in men but, like maximal resting pressure, were uninfluenced by age. Fistula type significantly influenced maximal resting and squeeze pressures, with tendency to low pressures and high incidence of defective anal control after operation for high intermuscular fistula. Maximal contractile power was unrelated to extent of external sphincter division. Rectal sensation and activity of the rectoanal reflexes did not appreciably differ between the continent patients and the others. Digital assessment of sphincter tone at rest and at maximal contraction correlated well with the respective anal pressures, but was an unreliable indicator of anal continence. The manometric findings warrant maximal preservation of the anal sphincter musculature, but fistula healing must not be thereby endangered.     

Uraemic arterial disease. An experimental study with special reference to the effect of parathyroidectomy.

A histophatologic study of uraemic arterial lesions was performed in rats. They were made uraemic by 5/6 kidney resection, and the aorta and peripheral arteries were examined after intervals of up to 36 weeks. The characteristics of the arterial lesions were necrosis of medial smooth muscle cells and, in some cases, calcification of the media. The changes appeared first in the aorta, but after long uraemic periods also in peripheral arteries. The incidence and severity of necrosis and of calcification were assessed separately. Parathyroidectomy largely prevented the development of calcification, and to a lesser degree also smooth muscle cell necrosis. The results suggest that secondary hyperparathyroidism plays an important part in the development of uraemic arterial disease.     

An experimental endoscopic study on intestinal ischemic lesions in dogs with special reference to fluorescence endoscopy

In order to clarify the pathophysiology of intestinal ischemic lesions and to make a useful method for the prediction of fate of the ischemic bowel, we devised an experimental model to produce the disorder. Microbarium of 0.5 micrometer in diameter was injected into a branch of the superior mesenteric artery of adult mongrel dogs. The severity of the ischemic lesions depended on the amount of microbarium injected, and lesions could be classified into three types; transient, stricturing and gangrenous, similar to clinical cases. Endoscopic examination was performed, accompanied with fluorescence endoscopy. Fluorescein could not be observed in all types soon after microbarium injection. In the transient type, fluorescein was observed after only a few days in an evenly distributed pattern. However in the stricturing type, the appearance of fluorescein was delayed, and an irregular pattern was observed in about 1 week. The submucosal blood flow was measured by hydrogen clearance method. The fluorescence endoscopic findings were nearly compatible with changes of submucosal blood flow. Fluorescence endoscopy is easily performed and appears to be highly useful in the differentiation of these three types of ischemia in the early stages.     

An experimental study on Pseudomonas osteomyelitis with special reference to the production of experimental osteomyelitis in mice (author's transl)]

I) The author has successfully produced a model of experimental osteomyelitis caused by pseudomonas aeruginosa using the following procedure though such a demonstration has been said to be very difficult. After impregnation in a solution containing about 10(5) pseudomonas aeruginosa, 3 mm silk thread of No. 5 was dried under low-pressure atmosphere and then inserted into the metaphysis of right tibia of a mouse. This method can be produced experimental osteomyelitis in 100% of the animals. In the experimental osteomyelitis generated pathologically by this method, inoculated organisms do not transmigrate into blood, the kidney and the contralateral tibia. This may therefore be regarded as a local infection causing no death, making a long period of observation possible. In view of the X-ray and patho-histological findings, it is similar to human osteomyelitis. Furthermore, its host is a pure-bred mouse with constant elements making a league-scale experiment possible. II) This is an experimental model of osteomyelitis proved quite useful for the quantitative analysis of the effects of antibiotics, and would be a good method for evaluation of antibiotics to be developed in the future.     

Structure and function of the experimental polycystic kidney induced by diphenylthiazole with special reference to renal micropuncture study]

Autosomal dominant polycystic kidney disease (ADPKD) is one of the major causative diseases leading to renal failure and dialysis treatment. Although the genetic study on the disease has been progressed so far, the initial trigger for cyst formation and several factors enhancing the progression of ADPKD remain to be clarified. Using an animal model of ADPKD, induced by 2-amino-4,5-diphenylthiazole hydrochloride (DPT), we examined the early events in cytogenesis. Especially the role of tubular obstruction in the model in triggering off tubular dilatation was investigated by means of renal micropuncture and tubular microperfusion techniques. Light and electron microscopic studies demonstrated epithelial hyperplasia along collecting ducts after 2 weeks of DPT feeding. In addition, some collecting ducts revealed partial obstruction with hyperplastic cells. Cystic change became prominent over 8 weeks of the treatment. Then micropuncture and microperfusion experiments were performed to measure intratubular pressure in the rats fed DPT for 2-5 weeks (PKD rats) and pair-fed control Sprague-Dawley rats (control rats). Free flow pressure in proximal segments of PKD rats (21.5 +/- 1.0mmHg) was not significantly elevated, as compared with that in control rats (21.3 +/- 1.0mmHg). During the stepwise increments in proximal tubular flow rate, proximal tubular pressure in PKD rats significantly increased especially at higher flow rate, 41.0 +/- 3.6 mmHg in PKD rats and 19.4 +/- 3.1mmHg in control rats (P < 0.01) at 40nl/min. On the other hand, the transit time of loop of Henle was longer in PKD rats (38.9 +/- 2.4 sec) than in control rats (24.9 +/- 0.6 sec, P < 0.01). These results suggest that cyst formation in PKD rats could be preceded by the elevation of tubular resistance, which might be explained by the partial obstruction of collecting ducts. Moreover, these tubular obstruction in the distal segments might be the trigger for the cyst formation in this model.