The eighth Frederick H. Verhoeff Lecture. presented by saiichi mishima, MD Behçet's disease in Japan: ophthalmologic aspects

The problems of Behçet's disease in Japan have been reviewed with particular emphasis on the ophthalmologic aspects: the historical background for the Japanese works, diagnostic critieria, epidemiology, some statistics, ocular symptomatology, ocular histopathology, etiology, pathophysiology, and treatment. Behçet's disease is the most frequent entity in endogenous uveitis in Japan. Patients are found throughout the country, and the prevalence rate averages seven to eight per 100,000 population: the rate is higher in the northern than in the southern districts. The diagnosis is made on the basis of a combination of clinical symptoms that are divided into the major and minor criteria symptoms. The major criteria comprise the ocular involvement, aphthous ulcers of the oral mucous membrane, genital ulcers, and skin lesions. These symptoms recur often as attacks and the disease follows a chronic course. The ocular involvement is found in 83% to 95% in males and 67% to 73% in females; the male to female ratio in the number of patients is 1.78. Both into the anterior segment type and the fundus and panophthalmic types. The anterior segment type shows serous iridocyclitis with the classic type of hypopyon appearing in about 12% of the attacks. This type is found in about 20%, more often in females than in males, and the visual prognosis is more favorable than in the fundus and panophthalmic types. In the latter two types, attacks of retinal angitis resulting in intensive retinal edema, yellowish-white exudate, and hemorrhages recur particularly in the macular region, and the visual prognosis is poor. More than 50% of male patients lose visual acuity to less than 0.1 in five years, but this is the case in only 10% of female patients. Consequently, Behçet's disease is the cause of blindness in about 12% of acquired blindness in adults. The ocular histopathology during the attack is characterized by severe angitis with intensive infiltration of neutrophil leucocytes largely in the uveal tract and the retina; the latter is severely affected and loss of visual cells and other neural elements results. The etiology of this disease still remains unknown but genetic predisposition is suggested since this disease is strongly linked with HL-A-B5. Environmental factors are also considered. Various abnormalities are found in the blood chemistry, blood cells (particularly in neutrophil leucocytes), immunologic mechanism, fibrinolytic and blood clotting system, and hormonal system. Chemotractic factors are found in the aqueous humor. These changes are particulary enhanced just before and during the ocular attacks. Systemic corticosteroids are deleterious to the visual prognosis, but cyclophosphamide and colchicine appear to suppress attacks and help patients maintain the visual acuity. However, these drugs are toxic, particulary to the reproductive organs, and the patients must be informed of this side effect and be allowed to make a decision before they are used.

Effects of ion etching on the properties of GaAs

Effects of ion etching on the optical properties and lattice disorder of GaAs were studied by means of photoluminescence, He backscattering, and enhanced chemical etching. The photoluminescence intensity excited by a He-Cd laser (3250 A), which penetrates a distance of approximately 150 A into GaAs, is decreased to less than 20% of the initial value after ion etching by 100-eV Ar and recovered almost completely by 450 degrees C annealing. Helium backscattering and electron diffraction pattern indicate the existence of an amorphous layer, the thickness of which is 20% larger than the value estimated by LSS theory. Photoluminescence measurement shows that beyond this amorphous region there are distributed a lot of nonradiative recombination centers as well as radiative recombination centers which diffuse into the bulk. The depth of this distribution is larger than that of the amorphous region by 1 order of magnitude.

Effect of human immunoglobulin preparations on Fc rosette formation between anti-D-coated erythrocytes and lymphocytes

Human immunoglobulin (Ig) preparations were tested for their inhibitory effect on Fc rosette formation between anti-D-coated human erythrocytes and lymphocytes, as compared to their complement activating capacity. Both of the two biological activities ascribed to the sites in the Fc portion of the IgG molecules were found to be reduced in the pepsin-treated, as well as in the S-sulfonated Ig preparations, as compared to the activities of the normal human Ig preparation. In the plasmin-treated Ig preparation, which was found to be composed of three major components: plasmin-Fab, plasmin-Fc and plasmin-resistant IgG, the activity of inhibiting the Fc rosette formation was well retained, in contrast to its low complement activating capacity.

Morphological changes in yeasts as a result of the action of 5-fluorocytosine

The mode of action of 5-fluorocytosine on Candida albicans and Saccharomyces cerevisiae was studied with special reference to morphology and ultrastructure. Shortly after contact of yeast cells with 10 mug of 5-fluorocytosine per ml, marked enlargement of the cells occurred. The initial increase in cell size was almost the same with both yeast strains. As incubation proceeded, further increase in cell volume continued with C. albicans, whereas no further change in cell volume was observed with S. cerevisiae. An electron microscope examination of C. albicans cells after exposure to the drug revealed characteristic changes, consisting of an enlarged nucleus and a thin cell wall. The morphological changes were exactly comparable to those reported with inhibitors of deoxyribonucleic acid synthesis in mammalian cells and some bacteria.

Effect of vagotomy on hyperinsulinemia in obese rats with hypothalamic lesions

With the purpose of investigating the pathogenesis of obesity and hyperinsulinemia in rats with hypothalamic lesions (HTL), HTL were made in vagotomized rats, and the development of obesity was serially followed up to 15 weeks as well as the changes of plasma triglyceride and immunoreactive insulin (IRI) levels. Even in vagotomized rats, obesity developed after HTL and plasma triglyceride and IRI levels increased significantly. However, obesity was slightly less in grade and occurred later as compared with sham-vagotomy-HTL rats. Plasma IRI levels in vagotomized rats significantly correlated with the body weight, Lee's index, the weight of adipose tissue and plasma triglyceride level. Similar results were also obtained in rats with HTL which were pair-fed following vagotomy. These results suggest that the hyperinsulinemia in obese rats with HTL may be involved not only by hypersecretion of insulin mediated by hypothalamo-vagal nerve system but also by some insulin-antagonistic factors such as increases of adipose tissues and plasma lipids.

Dose effect relationship for epilation and late effects on spinal cord in rats exposed to gamma rays

The response of rat spinal cords (T7-T12) exposed to single and multifractionated gamma-ray exposures revealed no significant differences between the threshold doses for 2 fractions given with a 24-hr. interval and 2 fractions given with a 15-day interval. The latent period for spinal cord damage was about 190 days when the incidence of paralysis was high; it was less than this in animals with a lower probability of paralysis. There was a marked sparing effect from dose fractionation: the initial part of a Strandqvist type of isoeffect curve had a slope of 0.44 for doses causing paralysis in 50% of the animals, and 0.36 for "threshold" doses. The level of epilation was not useful for predicting spinal cord damage.

Single dose response curves of normal cells in situ

Analysis of data on the response of normal tissues (skin, lung, spinal cord, intestine, testis) to single and multifractionated irradiation schedules revealed the characteristics of the single dose survival curves of target cells responsible for skin, lung, and spinal cord reactions, and of stem cells of colonic, jejunal, gastric mucosae, and testis exposed in situ to relatively low doses of x- or gamma-rays. The single dose survival curves of these cells seem to be complex (unlike those of cells studied in vitro), that is, simply exponential in the initial portion up to approximately 250 rads, and downward-bending thereafter in a curve which includes one or two linear portions on a semilogarithmic scale.