Localization of 5’-nucleotidase in the frog retina was investigated using histochemical and cytochemical techniques. Light-microscopic observations revealed the presence of this enzyme in the inner retinal layers (the nerve fiber layer, ganglion cell layer, and inner plexiform layer). Ultrastructural investigations revealed that the enzyme activity is associated with the plasma membranes of the...

DURING an investigation of the toxic action of beryllium salts on experimental animals a histochemical test was developed to provide information on the distribution and site of action of beryllium. The technique is reported as an example of the application of chemical methods to histological problems. The reactions of beryllium salts with dyes of the triarylmethane series have been studied by A...

A high capacity for accumulation of Mn was reported for sunflower plants. Localization of excess Mn is therefore of special interest for understanding metal tolerance mechanisms in this species. In this study, structural and histochemical alterations caused by Mn accumulation in leaves were investigated in sunflower (Helianthus annuus L. cv. Azar-ghol) plants grown in nutrient solution. In the ...

In a preceding article (1), the distribution of acid phosphatase activity was studied in a number of fractions separated from rat liver homogenates by differential centrifugation. It was found that less than 5 per cent of the enzymatic activity separates with the nuclear fraction, while over 90 per cen t remains associated with the cytoplasmic components. Among the latter, the mitochondria and ...

Reactive hyperemia reflects a compensatory vasodilation response of the local vasculature in ischemic tissue. The purpose of this study is to clarify the mechanism of regulation of this response in gingival circulation by using pharmacological analysis of reactive hyperemia and histochemical analysis of gingival tissue. Application of pressure to the gingiva was used to create temporary ischemi...

An enzyme histochemical study of the sinoatrial node, the coronary sinus, and the atrial muscle extending into the anterior mitral valve was performed on human hearts. Investigation of the activity and localization of the structurally bound enzymes was performed by conventional histochemical techniques. Determination of the activity of nonstructurally or weakly structurally bound enzymes was pe...

For the present study, and follow-up of histochemical changes in estradiol valerate-induced polycysticovary syndrome (PCOS), 48 virgin 90-day-old female rats were used. The rats were divided into thetreatment and control groups. For each rat of the treatment group, 4 mg estradiol valerate was injectedthrough intramuscular route for the induction of PCOS. The control group was taken the same amo...

A method for the determination of enzyme kinetic constants V(m), K(m), and K(i) in a histochemical system has been devised. As a substitute for the reciprocal of the reaction velocity, the times necessary to reach a fixed amount of end product (the initial visible color) in a tissue site at various substrate concentrations are plotted, according to the method of Lineweaver and Burk, against the...

-Four albumin conjugates of oestradiol. labelled with fluorescein or peroxidase to permit visualization under light or fluorescence microscopy, were synthesized. These were used to examine the feasibility of identifying oestrogen bind ing in frozen section by two published histochemical techniques. In a variety of experimental tissues and human breast cancers, binding of the oestrogen conjugate...

Localized tumors composed of immature cells of the myelogenous series have been recognized for many years as an uncommon manifestation of granulocytic leukemia. The histologic diagnosis of chloroma (granulocytic sarcoma) may be extremely difficult when the myeloblastic cells are poorly differentiated and the tumor lacks the characteristic green color. The diagnostic difficulty may be further co...