The origin of amyloid in gelatinous drop-like corneal dystrophy

The origin of amyloid in gelatinous drop-like corneal dystrophy, one of the primary corneal amyloidoses, was studied by light and electron microscopy. Milky-white granules over the corneal surface are the first clinical findings. In the initial stage, the amyloid substance exists between the basal cell of the corneal epithelium and the basal lamina of the cell. The basal lamina, Bowman's membrane and the stroma remained intact. Numerous filaments, about 7nm in width, were seen in the normal basal cells. In addition, many fibrils, about 10nm in width, were observed in the damaged basal cells. With progressing of the disease, the amyloid increased in amount and Bowman's membrane disappeared. Our results suggest that the basal cell of the corneal epithelium may produce and secreted the amyloid substance and gelatinous drop-like corneal dystrophy occurred.

Separation of concanavalin A-induced human suppressor and helper T cells by the autologous erythrocyte rosette technique

Very few normal human peripheral blood T cells are capable of binding autologous erythrocytes to form rosettes, whereas in the T cell population activated by concanavalin A (Con A) the autorosette levels are markedly enhanced. Fractionation of the Con A-activated T cells with autologous erythrocytes into autorosetting and nonrosetting cells demonstrates that suppressor, but not helper, activity resides in the autorosetting population, whereas the reverse is true of the nonrosetting population. Both these activities are found to be Con A dependent. The Con A-induced human suppressor cells can be identified and separated from the Con A-induced human helper cells by the autorosette technique. Studies on the surface properties of autorosetting and nonrosetting T cells indicate that there is little correlation between the activated suppressor and helper T cell subsets defined by autorosette technique and either those defined by monoclonal antibodies (which are able to distinguish these subsets in the resting but not activated T cells) or those defined by Fc receptors. Since the autorosetting T cell population (which acts as suppressor cells) bears receptors for peanut agglutinin, the nature of Con A-induced human suppressor cells appears to be analogous to that of Con A-induced murine suppressor cells.

Platelet aggregation and coagulation in the pathogenesis of diabetic retinopathy in rats

Fifty male rats were made diabetic by a single injection of streptozotocin and were killed at periods varying from 1 to 12 mo. Ten saline-injected rats and three rats treated with 3-O-methylglucose and streptozotocin served as controls. Intraluminal changes in retinal vessels were studied by electron microscopy. In diabetic rats maintained for 9-12 mo, microthrombus formation was observed in the various sized retinal vessels at the histologic and ultrastructural level. The microthrombi were mainly composed of aggregated platelets and fibrin strands. However, there was no definite evidence of detachment or loss of the endothelial cells. This microthrombus formation may play an important role in the development of diabetic retinopathy.

Increased sensitivity to 5-hydroxytryptamine due to intraventricular administration of 5,6-dihydroxytryptamine

The possibility that intraventricular administration of 5,6-dihydroxytryptamine (5,6-DHT) can cause a development of denervation hypersensitivity to central 5-hydroxytryptamine (5-HT) was examined in rats with special reference to the pituitary-adrenocortical functions. Pretreatment with intraventricular injection of 5,6-DHT itself did not affect the basal concentrations or stress-induced increases of plasma B. The same pre-treatment, however, elicited augmented responses to subcutaneous injection of 5-HTP, i.e. there was a significant rise in the concentrations of plasma B as compared with those in the controls. These results suggest a development of denervation hypersensitivity to 5-HT following intraventricular injection of 5,6-DHT.

[A simplified method for determination of biochemical marker genes in inbred strains of mice (author's transl)]

A rapid method is described for the determination of biochemical variants of mice by Titan III cellulose acetate electrophoresis. Variants examined were hemoglobin beta-chain, serum esterase-1, malic enzyme (supernatant form), and isocitrate dehydrogenase (supernatant form). The present procedure can be recommended as a simplified method to analyze biochemical variants for checking of marker genes in inbred strains of mice.

The effects of microinjection of carbachol or hemicholinium into the amygdala on the levels of plasma and adrenal corticosterone in rats

Microinjections of 0.4 microgram of carbachol into the amygdala caused a rise of corticosterone (CS) in the morning when the prestimulating level of CS was lower. But the same procedure with a larger dose had no effect in the afternoon, when the prestimulating level of CS was higher.

Ultrastructural studies on the secretory cycle of the neurosecretory cells and the formation of Herring bodies in the paraventricular nucleus of the rat

The ultrastructure of the neurosecretory cells in the paraventricular nucleus of the normal male rat was studied by electron microscopy during various functional states. Four morphologically distinct types of neurosecretory cells were observed. It appears that they do not represent different classes of cells but different phases of secretory activity of a single cell type. The perikarya of the neurosecretory cells show a definite cycle of formation and transportation of secretory granules. We have designated the phases of this cycle as: (1) phase of synthesis, (2) phase of granule production, (3) phase of granule storage and (4) phase of granule transport. The neurosecretory granules appear to be moved in bulk into the axons, forming a large axonal swelling filled with granules as a result of one cycle in the neurosecretory process. Thus it may be postulated that a secretory cycle in the perikaryon of the neurosecretory cell seems to result in the formation of a Herring body in its axon, and that its content is then conveyed to the posterior pituitary.