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Rats were injected subcutaneously on 2 consecutive days with various doses of four sympathomimetic amines. The doses chosen were the median lethal dose or fractions thereof. The animals were sacrificed at 48 hours and myocardial lesions were graded in the gross and after histological sectioning. A synthetic adrenergic agent, isoproterenol, was found to cause severe infarct-like myocardial necrosis. The lesions which were seen after isoproterenol treatment were more severe than those produced by l-epinephrine, l-arterenol, or ephedrine. This was the case whether the severity of the lesions was expressed in terms of single dose lethality of the compound or in terms of absolute amount. It was concluded that the myocardial lesions produced by these drugs are related to their cardiac stimulant properties.

A positive correlation was established between the extent of liver necrosis, measured planimetrically, and the serum glutamic pyruvic transaminase (SGPT) level in toxic hepatitis. Intoxicated rats treated with necrotropic drugs showed significantly lower SGPT values than the control animals. The measurement of SGPT level in toxic hepatitis in rats is suggested as a method for evaluation of hepatic necrotropic compounds.

The cortical tissue layer of the vitreous body, in adult mammals and in birds, is a solid tissue which is contiguous to the ciliary body and the retina and which contains a uniform population of cells called ȁhyalocytesȁ. Only the area contiguous to the optic disc contains another type of connective tissue cell, viz. fibrocytes. The largest number of cells per surface area of vitreous body is found at the ciliary body and at the optic disk.

Mucoid layer of the rooster comb and cartilage of the nasal septum of steers were used to measure the binding of cationic dyes by unfixed frozen sections. The amount of dye bound was calculated from the decrease of the optical density of the dyebath after equilibrium had been reached between the dyebath and the tissue at the saturation level. Various factors influencing this reaction, such as the tissue-dye ratio, the dyebath concentration, the thickness of the tissue sections and mechanical agitation, have been studied. In order to quantitatively determine the dyebinding, certain conditions must be fulfilled. The dyebath concentration must be high enough to be well in excess of all available binding sites of the tissue. The precipitate formed and the tissue fragments must be removed prior to optical density measurement. The electrolyte concentration of the dyebath must be kept below a certain level. The dyebath should not contain colored substances other than the free dye. Under these conditions, the amount of dye bound by azure A and other cationic dyes is constant for a given tissue, depending only on the pH of the dyebath. Electrostatic interaction between the cationic dye and the anionic sites of the tissue is primarily responsible for dyebinding. The quantitative determination of dyebinding is a measure of the free anionic sites of a tissue.

The urinary excretion of lyso-zyme was investigated in rats following administration of nephrotoxins. Signs of HgCl2and UO 2(NO3)2induced nephroses were accompanied by a moderate lysozymuria. Na2CrO4caused a disproportionately high excretion of this enzyme for 3 to 4 days, exceeding normal renal lysozyme content.Endogenous plasma lysozyme levels increased in nephrectomized rats, indicating an extrarenal source and a renal inactivation of this enzyme. Simultaneous measurements of renal clearances of exogenous lysozyme and creatinine demonstrated a decreased re-absorption of lysozyme in Na2CrO4, but a normal one in HgCl2dosed rats. The data imply a decreased tubular reabsorption of lysozyme in the pathogenesis of lysozymuria.

Twelve horses with traumatic arthritis were treated with intraarticular injection of hyaluronic acid mixed with cortisone and the results compared with 6 horses treated only with cortisone. There was a significantly better improvement in the group injected with a mixture of hyaluronic acid and cortisone. Further studies have given the same results in traumatic arthritis in horses if hyaluronic acid alone is injected.

The cellular components of the vitreous body have been subject to some controversy. It has been established that in the course of embryonic development the vitreous body contains numerous cells, but their nature and origin are not well known. The adult vitreous body is considered to be primarily cell-free. However, in the cortical layer, the so-called "hyaloid area," different types of cells have been described repeatedly.One of the first reports on the cells in the adult vitreous body is that of Henle (1841), who mentions "cytoblasts" in the vicinity of the zonula fibers. Donders (1847) studied the posterior surface of the vitreous body and described "corpuscles," which Doncan (1854) later characterized as cells. Doncan gives a detailed description of these cells in the cortical layer of the human vitreous body as well as in the vitreous body of cattle, dogs, cats, rabbits, and several kinds of fish. His illustrations

The distribution of C14 was studied in various parts of the rooster comb following treatment with testosterone. The value of gas-phase assay of C14 in tissue has been demonstrated and the results compared with those of autoradiographic studies on the same tissue. The results of these experiments showed that androgen treatment significantly increases the rate of incorporation of C14 in various parts of the comb. The specific activity of carbon in the comb, cornea, and liver differed, depending on which precursor, viz. glucose-6-C14, glucose-1-C14, and glucuronolactone-U-C14, was administered. The highest values were obtained after the administration of glucose-6-C14; glucuronolactone-U-C14 gave the lowest specific activity. The specific activity of carbon in different parts of the comb showed considerable variation. Carbon assay of serial sections of the comb cut at various planes showed that the specific activity of carbon was highest in the mucoid layer. Both C14 assays and autoradiograms indicate that C14 is also present in other parts of the comb. As seen in autoradiography, the concentration of C14 was highest in the epithelium, in the blood vessel walls, and in the avascular collagenous tissue. These results, and indications from previous studies, suggest that the high specific activity of carbon in the mucoid layer is due mainly to the presence of C14-labelled hyaluronic acid. Autoradiograms and PAS staining suggest that a significant amount of C14 is also incorporated into the glycoproteins associated with the collagen fibers.

The hyaluronic acid content of the mucoid layer of the rooster comb and the chondroitin sulfuric acid content of bovine nasal cartilage were determined in the fresh tissue, in the water extract of the tissue, and in the water-extracted residue. The binding of cationic dye by the tissue, the tissue extract and the residue was compared with the mucopolysaccharide content. The molar ratio of the bound dye to the anionic sites of the mucopolysaccharides varied between 1.1 and 1.8. In the comb extract this ratio was one. This indicates that, with the exception of the comb extract, anionic sites other than those of the mucopolysaccharides are also responsible for the dyebinding.

IT is now well established that brain slices and homogenates possess distinct high affinity uptake systems for all the major transmitter candidates or their immediate precursor molecules1,2. In the case of GABA and glycine the application of electron microscopic autoradiography to such in vitro preparations has revealed discrete populations of nerve terminals as the major site of amino acid uptake3. In brain slices or homogenates, however, nothing is known about the functional or anatomical identity either of the labelled or the unlabelled populations of terminals. In other words, it has not hitherto proved possible to confirm that each high affinity uptake process for any particular transmitter substance is present exclusively in those nerve terminals in the brain known from independent neurophysiological studies4to release that substance.

The synthesis of 4-{p-[(2-chloroethyl)-(2-hydroxyethyl)-amino]phenyl}butyric acid is reported. Investigation of the behavior of this compound in the NBP assay procedure showed that it alkylates NBP in a manner similar to chlorambucil. Therefore the results obtained from the assay of chlorambucil and similar aryl nitrogen mustards by the NBP method must be interpreted with due caution.

USING electron paramagnetic resonance (EPR) techniques, we have demonstrated that when complexes between cationic dyes and the naturally occurring anionic polysaccharides (heparin and hyaluronic acid) or the synthetic polyanion sodium poly(ethylene sulphonate) are exposed to light, the complexes become paramagnetic. The EPR spectra showed no hyperfine splitting and the intensity of the signal was not temperature-dependent. The action of the light promotes electron transfer within the complex1. We report here that the solid complexes between DNA, RNA and a range of cationic dyes exhibit a similar type of behaviour.

Hypotheses on the mechanism of gold's antirheumatic action are reviewed, and preliminary results of estimations of plasma gold levels in five patients with rheumatoid arthritis receiving chryso‐ therapy are described. Varying levels in different patients on similar dosage, and long persistence following cessation of therapy were observed. Individual plasma gold levels are correlated with gold dermatitis.

STERILE, healing wounds (rats) were extracted with physiological salt solution. Extracts were made from wounds of ages from 1 to 12 days. The extract was dialysed with several changes of distilled water at a low temperature in a ‘Cellophane’ tube. In this way the albumin and globulin fractions of the extracts could be separated. Both solutions were then brought to pH 6.5–7 and diluted to the same dry-weight concentration. The usual heart fibroblast cultures in Carrel flasks and Carrel glasses were later treated with the prepared extracts. The results are given in Fig. 1, in which the zero horizontal line represents the usual index of increase for the corresponding control culture. A minus index means growth inhibition, and a plus index represents increase of growth.

A rapid procedure for the assay of methotrexate samples (bulk or formulated) has been developed in these laboratories. This procedure, which employs quantitative paper chromatography, makes use of relatively inexpensive equipment and is simple to execute.

The new approach to glucose estimation by polarographic oxygen determination as used in the Beckman glucose analyser (BGA) has led to a reappraisal of the relationship of whole blood to plasma and specific glucose methods to reduction methods.