Tissue culture of the retinal pigment epithelial cells

Pure culture of the retinal pigment epithelial (RPE) cells of the chick embryo was carried out and the morphological characteristics of each developmental stage were observed under light microscope and transmission and scanning electron microscopes. Immature cells had a few, short processes on the apical surface and a few melanin granules in the cytoplasm. However, mature cells had two types of processes on the apical surface, one being narrow and the other wide. Many melanin granules were diffusely dispersed in the cytoplasm and the cells were joined by a junctional complex near the apical portion. Beneath the cultured cells, basement membrane and collagen fibrils were evident and were apparently produced by the culture RPE cells. The structure of the cultured cells in the well-differentiated stage appeared to be the same as that of living cells.     

Occlusive thromboaortopathy (Takayasu's disease): cervical arterial stenoses, retinal arterial pressure, retinal microaneurysms and prognosis

Eighty-one young Japanese patients with occlusive thromboaortopathy (Takayasu's disease) were classed into three groups according to the degree and extent of diameter stenosis in the 4 cervical arterial systems, as determined by serial aortography. Class I was made up of 63 patients with 70% or greater stenosis in less than 3 systems, including 33 patients without systemic hypertension (Class Ia). Class II was made up of 6 patients with 70% or greater stenosis in 3 systems and less than 50% stenosis in the remaining 1, including 5 patients without systemic hypertension (Class IIa). Class III was up of 12 patients with 70% or greater stenosis in 3 systems and 50% or greater stenosis in 1 system. Ophthalmodynamometric systolic pressure in patients in Class III was significantly lower than that in patients in Class IIa (p less than 0.001), but there was no significant difference between patients in Classes Ia and IIa. Microaneurysms and/or arteriovenous anastomoses in the retinal vessels were found in all but one patient in Class III and in only one patient in combined Classes I and II. These results indicate that each of the ophthalmodynamometric values and fundoscopic findings are very helpful in identifying the markedly severe occlusive lesions (Class III) of the 4 cervical arterial systems. In this chronic disease, however, angiography is most useful for evaluation of these severe lesions, to monitor progression from Classes I and II to Class III, in which the prognosis is rather poor.     

Arthroscopic surgery for synovial chondromatosis of the hip: a report of two cases

We have used arthroscopy in the treatment of synovial chondromatosis of the hip joint. Two patients complained of pain of the hip joint that was aggravated by weight bearing. On admission, range of motion of the affected hip joints was slightly restricted. At hip arthroscopy, osteochondral loose bodies were removed from the joint and partial synovectomy was performed. Histologic examination revealed synovial chondromatosis. Pain relief was obtained in both patients postoperatively.     

Salivary flow rates during relaxing, clenching, and chewing-like movement with maxillary occlusal splints.

The purpose of this study was to test the hypothesis that the application of occlusal splints increases the diurnal salivary flow rate both in bruxism patients and in normal subjects. Salivary flow rates in 16 adult volunteers (8 bruxism patients and 8 sex- and age-matched control subjects) were measured with the spitting method. There was no significant difference in the salivary flow rate with or without splints between the control and bruxism groups. In all subjects, the salivary flow rates with splints were significantly higher than those without splints during relaxing, clenching, and chewing-like movement. The salivary flow rate during the chewing-like movement was significantly higher than that during relaxing and clenching, irrespective of splint application. The results suggest that maxillary occlusal splints might stimulate salivary secretion, particularly during chewing-like movement, in both bruxism patients and normal subjects.     

Effect of mexiletine on human atrial vulnerability

The effect of mexiletine on human atrial vulnerability was investigated in 14 subjects (8 with paroxysmal atrial fibrillation, 2 with paroxysmal atrial tachycardia, 2 with ventricular tachycardia, 1 with sick sinus syndrome and 1 with Wolff-Parkinson-White syndrome). During the electrophysiologic study, after 8 consecutive stimuli (A1) were delivered through the electrode catheter positioned at high right atrium, premature stimulus (A2) was introduced, and following measurements were made; 1) Aw: atrial activity width of A1, 2) maximum atrial fragmentation (MAF): the longest atrial activity width of A2, which was expressed by the relative value against Aw, 3) fragmented atrial activity zone (FAZ): the zone of the coupling interval (A1A2) with the prolongation of the atrial activity width at A2 more than 150% against Aw, 4) conduction delay zone (CDZ): the zone of A1A2 with the prolongation more than 20 msec of the intraatrial conduction time at A2 from high right atrium to coronary sinus or low right atrium against the intraatrial conduction time at A1, and 5) right atrial effective refractory period (RAERP). These measurements were repeated after the intravenous administration of mexiletine (2 mg/kg/10 min). 3 cases (case 12, 13 and 14), whose FAZ and CDZ were 0 msec, were excluded from the following evaluation. Mexiletine showed little effect on Aw and RAERP, but significantly shortened MAF and FAZ (p less than 0.001 and p less than 0.05, respectively). CDZ were also reduced in 3 cases and remained unchanged in 6 cases, though no statistical difference of CDZ was recognized between before and after the administration of mexiletine.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lipid peroxide and antioxidant enzymes in muscle and nonmuscle of dystrophic mouse

To determine whether abnormality in redox metabolism occurs specifically in certain individual dystrophic muscles, thiobarbituric acid reactivity, free radical scavengers, and oxidative marker enzymes were measured in the liver, kidney, erythrocytes, heart, and four different individual skeletal muscles from C57BL/6J dy/dy mice. Superoxide dismutases were assayed by specific radioimmunoassays, which enabled the study of a small individual murine muscle. Glutathione peroxidase and catalase were increased markedly in each individual dystrophic skeletal muscle studied and less markedly in the heart. Manganosuperoxide dismutase and thiobarbituric acid reactivity were decreased to a similar extent in each dystrophic skeletal muscle. Cuprozinc superoxide dismutase was decreased in the soleus muscle. Only a minimal biochemical change occurred in nonmuscles. Fumarase activity correlated closely with the level of manganosuperoxide dismutase. These results suggest that muscle protein breakdown occurs independently of lipid peroxidation despite the presence of tissue-specific abnormality of redox metabolism in dystrophic muscle.