Sam Frankel

Photometric Method for Estimation of Elastase Activity.

Summary A colorimetric method for the estimation of elastase activity has been presented. When dyed elastin substrate prepared from horse ligamentum nuchae is used, the pH optimum lies between 8.7 and 9.4, and the reaction velocity is linear only when less than 35% of the elastin is dissolved. When compared with the gravimetric and nitrogen procedures, this method has the advantages of rapidity and simplicity.

gamma Aminobutyric acid content and glutamic decarboxylase activity in developing mouse brain.

Summary Brain weights, content of γ−aminobutyric acid, and the activity of glutamic acid decarboxylase were determined in brains of mice at various stages of postpartum development. All of the quantities studied increased greatly during postnatal development, attaining their maximal levels at 90 days. The increase in decarboxylase activity was slower during the first two weeks than that of the weight and the γ−aminobutyric acid. A cytological study revealed that the period of greatest increase in glutamic acid decarboxylase activity is correlated with the period of greatest increment in features which are related to maturation of the central nervous system. Examination of selected samples of nervous tissues of the cat, dog, and rabbit showed that the glutamic decarboxylase-γ−aminobutyric acid system is present chiefly in the gray matter of the central nervous system. The results of the present study were correlated with relevant data from the literature.

Amino Acids of Nervous Tissue

Summary The pattern of free amino acids in mouse brain, as shown by 2-dimensional paper chromatography, does not reflect the amino acid composition of the brain as a whole. The brains of mice of several strains and various parts of the nervous system of the rabbit were studied. Free glutamic and aspartic acids, γ-aminoibutyric acid, taurine, glutamine, cystine, serine, glycine, alanine, valine, and the leucines were detected consistently. The variations in these constituents with age, sex, and strain in mice are discussed. The sciatic nerve in the rabbit had considerably smaller quantities of detectable constituents than the various parts of the central nervous system. A transplantable neuroblastoma in mice had a pattern of free amino acids which was similar to that found in other malignant tissues and in brains of 15-day embryos and significantly different from that found in all of the other samples of mouse brain examined. The suitability of the chromatographic method for the study of changes in the free amino acids of brain homogenates is indicated.

Influence of cortisone on free hydroxyproline in the developing chick embryo.

Summary A chromatographic examination was made of the free amino acids of tissues of normal and cortisone-injected chick embryos. The content of free hydroxyproline was increased markedly in the tissues of the cortisone-treated embryos. The results were confirmed by a colorimetric procedure. With the exception of glycine, in which increases were noted in some instances, the other amino acids showed no consistent changes as a result of the injection of cortisone. The injection of Δ 1 -17 α-hydroxy progesterone produced slight decreases in free hydroxyproline content.

Aging of the placenta: Autoimmune theory of senescence

Abstract Contrary to the traditional view of aging of the placenta, the authors propose that it undergoes senescence in a manner comparable to the misspecification-autoimmune theory as it obtains in respect to aging of individuals generally. Evidence is presented indicating that the fibrinoid present in the placenta is comparable to amyloid, which is recognized as one of the end products of aging and immune reactions. The possible relationship of these findings to the altered immune response which allows the maternal host to retain her fetal transplant is discussed.

Influence of Administration of ACTH on Urinary Amino Acids

Summary Typical results are presented showing the influence of ACTH a dministration in the human on the urinary excretion of nitrogenous substances. The hormone evoked notable increases in the excretion of amino acids, ammonia, urea, uric acid, and some undetermined nitrogenous constituents. Twodimensional chromatograms revealed some of the detailed changes in the excretion of both free and bound amino acids. Microbiological determination of some of the amino acids gave results which were concordant with the chromatographic findings. All of the urinary nitrogenous constituents returned to normal levels shortly after cessation of the treatment. The possible significance of some of the findings is indicated.

The preparation of highly concentrated allergenic extracts by increasing the concentration of extraction: I. Timothy and low ragweed pollens

Abstract 1.1. Highly concentrated timothy and low ragweed pollen extracts have been prepared by direct extraction. 2.2. Extracts of timothy and low ragweed pollens, prepared in increasing weight by volume ratios, from 5 to 50 per cent, showed a distinct proportionality, indicating extraction in linear ratios, as measured by total and phosphotungstic acid-precipitable nitrogen content, concentration of reducing substances, and reagin neutralization activity. 3.3. The use of glycerinated extracting fluids was necessary in the preparation of such highly concentrated and potent extracts to avoid sedimentation and to preserve activity.

Fractionation of pollen extracts: II. Chemical and paper chromatographic investigation of ragweed pollen extracts☆

Abstract 1.1. The solvent for paper chromatographic separations of skin reactive allergens must be chosen with great care. Lutidine can combine chemically with certain compounds and is in itself capable of producing skin reactions. 2.2. Fractions very similar to those previously obtained with lutidine were separated by use of a nonskin reactive solvent, methyl cellosolve. Such fractions exhibited skin reactivity. From this it has been concluded that the originally separated lutidine fractions were actually active components of dialysate. 3.3. Activity in the dialysate of ragweed extracts appears to be due to breakdown of originally larger particles, as shown by the extreme lability of the fractions isolated by paper chromatography. 4.4. Nearly all of the skin reactivity present in dialysate was precipitable by making an aqueous solution 60 per cent with respect to acetone. 5.5. Chemical fractionation of the nondialyzable portion of ragweed extract failed to produce an active fraction which was completely free of either protein or carbohydrate, respectively. Warm alkaline hydrolysis and phenol extraction came closest to producing such a fraction although the specific activity was reduced in both cases. Dialysate did, however, produce a few skin reactive carbohydrate-free fractions. 6.6. The active components appear to consist of a protein-carbohydratepigment complex, the carbohydrate component being a polysaccharide of arabinose.