No abstract

The immunological specificity of the Amsterdam rabbit antiserum against human prostatic acid phosphatase was studied on paraffin sections of 200 prostatic carcinomas and 330 control tissues using an indirect peroxidase technique. Peripheral blood leucocyte smears were also investigated with a fluorescent technique. In a limited number of cases, the mixed aggregation immunocytochemical method was also applied as post-primary incubation procedure. The diaminobenzidine (DAB) final reaction product of the peroxidase technique, carried out under standard conditions, was quantified in some cases using the Leyden Television Analysis System (LEYTAS) with a built-in standard. A positive reaction was obtained in 96.5% of the prostatic carcinomas. Only 2.1% of the non-prostatic tumour cases (23 types) showed a positive reaction, namely six out of 10 insulomas and one out of 10 carcinoid tumours. The beta-cells of the normal islet of Langerhans and the leucocytes in the smears showed a positive reaction. The sensitivity of the peroxidase method, judged subjectively, is not only dependent on the circumstances of fixation, embedding and incubation but also on the degree of tumour differentiation. None of the three prostatic carcinomas studied reached the level of DAB staining intensity shown by the hyperplastic prostatic epithelium.

An indirect immunohistochemical technique is

Improved histochemical techniques for the demonstration of NADP+-specific isocitrate dehydrogenase and malate dehydrogenase in tissue sections are described. With these techniques a semipermeable membrane is interposed between the incubating solutions and the tissue sections preventing diffusion of enzymes into the medium during incubation. In the histochemical system the NADP+-dependent enzymes catalyze the electron transfer from threo-Ds-isocitrate or L-malate into NADP+. Phenazine methosulphate and menadione serve as intermediate electron acceptors between reduced coenzyme and nitro-BT. Sodium-azide and amytal are incorporated into the incubating-medium to block electron transfer to the cytochromes. For demonstrating enzyme activities in sections containing non-specific alkaline phosphatase, a phosphatase inhibitor is added into the incubation media. Problems involved in the histochemical demonstration of both enzymes are discussed.

In this communication, the results of applying various histochemical techniques for the localization of oxidoreductases, transferases, hydrolases and isomerases in the human heart are presented. The Purkinje fibres of the atrioventricular conducting system of the human heart differ from the myocardium proper in containing a slightly higher activity of most of the glycolytic and gluconeogenetic enzymes investigated. The relatively higher activity of 6-phosphofructokinase, the key enzyme in anaerobic carbohydrate metabolism, is especially noteworthy. On the other hand, the activities of some of the enzymes that play a part in the aerobic energy metabolism is slightly less than those in the myocardium fibres. As for the activity of the NADPH regenerating enzymes, the activity of 6-phosphogluconate dehydrogenase and malate dehydrogenase (oxaloacetate-decarboxylating) is somewhat higher, and the activity of glucose-6-phosphate dehydrogenase similar, in the Purkinje fibres compared to that in the myocardial fibres. The activity of myosin ATPase is similar for both types of fibre. Likewise, the fibres of the conducting system and of the myocardium show a similar activity of acid phosphatase, beta-glucuronidase, non-specific naphthylesterase and peroxidase. The neurogenic function of the conducting system of the human heart was demonstrated by the high activity of acetylcholinesterase in the Purkinje fibres and in the atrioventricular node. All these histochemical findings in Purkinje fibres are similar at widely differing levels of the conducting system.