Chick Heart Tissue Research Articles

Amino acid composition of the culture fluid during cultivation of chick and rat heart tissue explants in medium M 150

Studies were made of changes in the amino acid composition of the medium during cultivation of nutritionally depleted explants of adult chick heart tissue and adult rat heart tissue. All cultures were found to effect a marked removal of cystine, lysine, histidine, arginine, leucine, isoleucine, valine and phenylalanine from the medium but they showed differences in the rates of removal of these amino acids. Cultures of chick tissues were found to utilize glutamic acid and release glutamine into the culture fluids, whereas those of rat tissue were found to do the reverse. No significant change was observed in regard to the other amino acids.

Glutamine metabolism of chick-heart tissue, rat-heart tissue, and human hypertrophic cervical tissue cultivated in synthetic media.

Glutamine metabolism of chick-heart tissue, rat-heart tissue, and human hypertrophic cervical tissue cultivated in synthetic media.

An improved tissue toxicity technique for the evaluation of germicidal substances.

The method generally employed for the evaluation of germicides is known as the phenol coefficient test. This test in one form or another is universally employed for the determination of the germicidal potency of compounds or preparations recommended for the destruction of bacteria. The most widely used modification in this country at the present time is the Ruehle and Brewer (1931), U. S. Food and Drug Administration (FDA) phenol coefficient method. The test was originally designed to be used for comparing the bactericidal potency of phenol with phenol-like compounds. However, in recent years the method has been used for the examination of compounds which are totally unlike phenol, with the result that such evaluations have been the cause of considerable confusion and of doubtful value. Another departure has been the freedom which some investigators have taken with the test itself, changing the procedure to favor the compounds under examination. Regardless of the many modifications of the original procedure which have been proposed, it is generally agreed that a phenol coefficient test is of very little or no value for determining the efficiency of a germicide intended for clinical application. A phenol coefficient attempts to compare the toxicity of a germicide for a given organism with that of phenol but gives no information as to its effect on living tissue. For example, a germicide with a high phenol coefficient and a proportionately high toxicity to living tissue would have no advantage over one with a low phenol coefficient and a proportionately low toxicity to living tissue. A new method was proposed in 1935 (Salle and Lazarus), and modified in 1938 (Salle, McOmie, Shechmeister, and Foord), for the evaluation of germicidal substances intended for clinical application (figure 1). The germicides were tested for their effect on living embryonic chick heart tissue fragments as well as for their ability to kill bacteria. Two tests were performed. In one test the bacteria were exposed to a series of dilutions of germicide for 10 min, then transfers were made to nutrient broth to determine the killing dilution. In the other test the tissue fragments were exposed to a series of dilutions of germicide for 10 min, then washed twice with saline, and finally embedded in rabbit plasma to determine the killing dilution. A number known as the Toxicity Index was calculated from the results, which was defined as the ratio of the highest dilution of germicide required to prevent growth of the tissue fragments in 10 min to the highest dilution required to kill the test organism in the same period of time and under similar conditions. Theoretically, an index greater than one means that the germicide is more toxic to the tissue fragments than to the bacteria. As the number increases in size, the germicide decreases in value. Conversely, an index smaller than one means that the germicide is more toxic to the test organism than to the embryonic tissue fragments. As the fraction decreases in magnitude, the germicide increases in value. The smaller the toxicity index the more nearly perfect the chemotherapeutic agent. A phenol coefficient is not determined, and no reference is made to it. There is no relation whatsoever between a phenol coefficient and a toxicity index. In the present investigation the tissue toxicity and the bactericidal tests have been combined in one operation making the procedure simulate actual conditions of germicide therapy as closely as possible.

An Improved Tissue Toxicity Technique for the Evaluation of Germicidal Substances

The method generally employed for the evaluation of germicides is known as the phenol coefficient test. This test in one form or another is universally employed for the determination of the germicidal potency of compounds or preparations recommended for the destruction of bacteria. The most widely used modification in this country at the present time is the Ruehle and Brewer (1931), U. S. Food and Drug Administration (FDA) phenol coefficient method. The test was originally designed to be used for comparing the bactericidal potency of phenol with phenol-like compounds. However, in recent years the method has been used for the examination of compounds which are totally unlike phenol, with the result that such evaluations have been the cause of considerable confusion and of doubtful value. Another departure has been the freedom which some investigators have taken with the test itself, changing the procedure to favor the compounds under examination. Regardless of the many modifications of the original procedure which have been proposed, it is generally agreed that a phenol coefficient test is of very little or no value for determining the efficiency of a germicide intended for clinical application. A phenol coefficient attempts to compare the toxicity of a germicide for a given organism with that of phenol but gives no information as to its effect on living tissue. For example, a germicide with a high phenol coefficient and a proportionately high toxicity to living tissue would have no advantage over one with a low phenol coefficient and a proportionately low toxicity to living tissue. A new method was proposed in 1935 (Salle and Lazarus), and modified in 1938 (Salle, McOmie, Shechmeister, and Foord), for the evaluation of germicidal substances intended for clinical application (figure 1). The germicides were tested for their effect on living embryonic chick heart tissue fragments as well as for their ability to kill bacteria. Two tests were performed. In one test the bacteria were exposed to a series of dilutions of germicide for 10 min, then transfers were made to nutrient broth to determine the killing dilution. In the other test the tissue fragments were exposed to a series of dilutions of germicide for 10 min, then washed twice with saline, and finally embedded in rabbit plasma to determine the killing dilution. A number known as the Toxicity Index was calculated from the results, which was defined as the ratio of the highest dilution of germicide required to prevent growth of the tissue fragments in 10 min to the highest dilution required to kill the test organism in the same period of time and under similar conditions. Theoretically, an index greater than one means that the germicide is more toxic to the tissue fragments than to the bacteria. As the number increases in size, the germicide decreases in value. Conversely, an index smaller than one means that the germicide is more toxic to the test organism than to the embryonic tissue fragments. As the fraction decreases in magnitude, the germicide increases in value. The smaller the toxicity index the more nearly perfect the chemotherapeutic agent. A phenol coefficient is not determined, and no reference is made to it. There is no relation whatsoever between a phenol coefficient and a toxicity index. In the present investigation the tissue toxicity and the bactericidal tests have been combined in one operation making the procedure simulate actual conditions of germicide therapy as closely as possible.

Amino Acid Formation From C14‐Labelled Glucose in Cultures of Fibroblasts from Embryonic Chicken Heart Tissue.

Amino Acid Formation From C¹⁴‐Labelled Glucose in Cultures of Fibroblasts from Embryonic Chicken Heart Tissue.

Protein Metabolisiu of Tissue Cells in Vitro. 7. The Chemical Nature of Some Obligate Factors of Tissue Cell Nutrition

Fibroblasts from embryonic chicken heart tissue have been cultivated on a simple artificial medium containing dialyzed plasma, dialyzed serum, Tyrode solution and fructose-1.6-diphos-phate Ca-salt, glutamine, cystine and glycine. One drop per culture of dialyzed embryonal extract was used as clotting agent. By replacement experiments it could be shown that the four low-molecular components were obligate necessary to the growth and maintenance of the cultures. The experiments have been carried out both in Carrel flasks and in hanging drop cultures. Hypoxanthine added to the above medium, increased the growth ratio. Hanging drop cultures on this medium have been transferred 5 times during a period of 10 days without any visible change of morphological status. With aid of paper partition chromatography it has been found that reducing sugars (glucose) organic phosphates, especially aminoethanol phosphoric ester, glutamine, cystine, glycine and hypoxanthine are present in dialysate from calf embryo muscle extract, the latter previously known to contain a complete set of low-molecular accessory growth factors for the cultivation of fibroblasts from embryonal chicken heart tissue in vitro. The five components used in the synthetic medium: Glucose + a suitable phosphate source, glutamine, cystine, glycine and hypoxanthine, which also exist in extracts from embryonal tissue could be regarded as the main nutritional low-molecular components for the growth and maintenance of fibroblasts from embryonic chicken heart tissue in vitro and in vivo.

Subtilin-Antibiotic Produced by Bacilius subtilis. II. Toxicity of Subtilin to Living Embryonic Tissue.

SummarySubtilin, an antibiotic extracted from Bacillus subtilis, was found to be antagonistic chiefly against Gram-positive organisms, including Mycobacterium tuberculosis and other acid-fast bacteria. Two notable exceptions were Neisseria catarrhalls and N. gonorrhoeae, both Gram-negative but also antagonized by subtilin. The antibiotic showed an extremely low toxicity for embryonic chick heart tissue fragments cultivated in vitro. Under the conditions of the test subtilin was approximately 20 times more toxic to Staphylococcus aureus than to chick heart tissue, a remarkably low tissue toxicity. A unit of subtilin is defined as the amount contained in 1 cc of the highest dilution capable of killing Staphylococcus aureus in 10 minutes at 37°C (F.D.A. phenol coefficient method).

Nature of Hydrosulphosol and Its Toxicity to Living Embryonic Tissue

ConclusionsEvidence has been presented to show that Hydrosulphosol is an available and convenient source of -SH radicals. The compound rapidly decolorizes methylene blue and supports the growth of the anaerobic organisms Clostridium sporogenes and Clostridium perfringens under aerobic conditions. The compound is relatively nontoxic to embryonic chick heart tissue fragments cultivated in vitro.

Effect of Lactogenic Hormone on Embryonic Tissues Cultivated in vitro.

Since lactogenic hormone is known to produce a specific effect on epithelial cells of the pigeon cropin vivo, experiments were designed to determine whether it would stimulate the growth of embryonic pigeon crop epithelium cultivated in vitro. If stimulation could be observed in this manner such a test might be more delicate and superior to the present methods employed for determining hormonal potency. Preliminary to testing the hormone on the specific crop epithelium, which reacts to it in vivo, experiments were carried out on the following non-specific tissues cultivated in vitro: (1) Embryonic chick connective tissue, (2) embryonic chick epidermis, (3) embryonic pigeon oesophageal epithelium. Finally the hormone was tested on cultures of embryonic epithelium taken from the crop sac areas known to be reactive in vivo in the hatched pigeons. In all cases the dilutions were performed in triplicate. Also, every experiment was repeated 3 times before the results were reported. Each flask contained about 12 fragments of tissue. (1) Embryonic Chick Connective Tissue. Chick heart tissue from 10- to 14-day-old embryos was used as the source of fibroblasts. The tissues were finely cut into fragments of about 1 mm. in diameter and immersed in Tyrode solution until ready for use. The embryonic fluid was prepared by mincing 14-day-old chick embryos in a tissue grinder and suspending the pulp in 4 parts of Tyrode solution. The suspension was centrifugated at high speed to throw down all cellular material after which the clear supernatant fluid was carefully removed with a pipette. This clear liquid was used for coagulating the plasma as well as a nutrient for the tissue cells. Guinea pig plasma was used in all experiments. This was collected by first drawing 1.0 cc. of a 1-1,000 solution of heparin into a 10.0 cc. syringe and then heart blood to the 10.0 cc. mark. The mixture was quickly centrifugated, the clear plasma removed with a pipette and kept in ice water until ready for use.

Resistance of Bacteria and Embryonic Tissue to Germicidal Substances. VI. Iodine Trichloride

Iodine trichloride (ICl3) was first introduced as a germicide by von Langenbach. It was described as a powerful disinfectant and recommended for the sterilization of hands, instruments and other surgical uses. According to Hailer the chemical is stable in concentrated solutions. In less concentrated solutions the iodine trichloride decomposes into iodine mono-chloride, iodic acid and hydrochloric acid, according to the equation, 2 ICl3 + 3 H2O → HIO3 + ICl + 5 HCl. In more dilute solutions the iodine monochloride decomposes to form iodic acid, free iodine and hydrochloric acid, 10 ICl + 6 H2O → 2 HIO3 + 8 I + 10 HCl. The effectiveness of the compound is due probably to the amount of free iodine liberated. In the first paper of this series methods were described for comparing the resistance of bacteria and embryonic chick heart tissue to germicidal compounds. A Staphylococcus aureus phenol coefficient and a toxicity index were determined for each germicide tested. The highest dilution of phenol required to kill Staphylococcus aureus in 10 minutes but not in 5 minutes was 1:65. For iodine trichloride it was 1:6,000. This gave iodine trichloride a Staphylococcus aureus phenol coefficient of 92 by the method of Reddish. Rideal and Rideal reported that a concentration of 50 parts per million was required to destroy typhoid bacilli in 30 minutes. A saturated aqueous solution showed a phenol coefficient of 94. The activity of the compound was found to be only slightly impaired by the addition of albumin or salts. Behring stated that iodine trichloride was a powerful disinfectant. He found that a 0.1% solution killed vegetative cells in one minute and a 1% solution destroyed spores within a few minutes.

Comparison of Resistance of Bacteria and Embryonic Tissue to Germicidal Substances. IV. Hexylresorcinol

Leonard1, 2 in his studies on some alkyl derivatives of resorcinol reported excellent results from hexylresorcinol when used as a urinary disinfectant. He stated that, “Hexylresorcinol, a stable organic substance of known chemical constitution, is the most powerful germicide ever described as a non-toxic substance. Hexylresorcinol is non-toxic by mouth and is administered in repeated doses for indefinite periods.” Leonard and Wood,3 Leonard and Frobisher,4 Frobisher5 and Leonard and Feirer6 found that hexylresorcinol was a powerful surface tension depressant and that its remarkable germicidal property was probably dependent upon this physical property.In previous papers of this series7, 8, 9 comparisons were made of the resistance of Staphylococcus aureus and embryonic chick heart tissue to Merthiolate, Metaphen, Mercurochrome and phenol. A Staphylococcus aureus phenol coefficient and a toxicity index were determined for each germicide. The methods followed were the same as those described in the first co...

Studies on the growth of tissues In vitro

ABSTRACT A method is described by which cells in the zone of outgrowth of cultures in flasks can be photographed at definite intervals over long periods of time. The rate of growth of chick heart tissue when growing in the presence and absence of embryo extract has been investigated. A numerical value, the growth index, has been calculated which expresses the mitotic activity of the culture during the periods of observation. In plasma alone the growth index is approximately 3 after 20 hours of growth and falls to zero at the 70th hour if the fluid medium above the plasma (in this case Tyrode) is not renewed. In plasma and embryo extract-(fluid medium embryo extract unchanged) the growth index is approximately 9 after 30 hours of growth, and falls to zero at about the 140th hour. If the fluid medium is frequently renewed with fresh embryo extract the growth index quickly falls to 3, and in the one case followed for more than 4 days it remained fluctuating about that level for the next 6 days, in fact for as long as it was practically possible to prolong the experiment. It is suggested that the method has many applications in connection with problems associated with the growth rates of tissues and organisms.