Cent Acetic Acid Research Articles

Heterochromatic Segments in Vicia revealed by Treatment with HCI–Acetic Acid

YAMASAKI1 reported that H segments became visible in the mitotic metaphase chromosomes of Cypripedium debile following treatment with a 1 : 9 mixture of 1 normal HCl and 45 per cent acetic acid or acetic orcein for 15 min at 60° C. Sharma and Roy2 and Sen3, using the orcein mixture at 90° C, claimed that the treatment caused chromosome breakage at non-specific sites within a minute. The present experiments on Vicia faba (“Nagasaya Soramame”) studied the effects of these mixtures and the separate effects of 1 normal HCl and 45 per cent acetic acid. Treatments lasting 1–5 or 10 min were given at 60° C and 90° C. Pretreatment with colchicine was necessary to facilitate observation, but fixation in acetic alcohol before treatment was not helpful.

Changes in Spleen Cell CFU Radiosensitivity Following Transplantation

Hematopoietic tissues contain a class of cells capable of forming spleen colonies (CFU) in heavily irradiated animals (1). McCulloch and Till (2) showed an in vitro and in vivo difference in radiation sensitivity of bone marrow CFU to cobalt-60 gamma rays, as measured by spleen colony-forming ability. Spleen-cell radiosensitivity also differed under in vitro and in vivo irradiation conditions (3). Siminovitch et al. (4) showed that colony-forming cells of different origins and past histories are dissimilar with respect to several properties, such as radiosensitivity. The radiosensitivity of transplanted spleen cells was studied at different time intervals following transplantation. Considerable changes in CFU radiosensitivity2 were found following the transplantation of the cells and observed during the period before CFU proliferation occurs (5). Inbred C3H(Z) male and female mice between two and four months of age were used in these experiments. Donors and recipients were from the same inbred colony and were of the same age and sex in each experiment. Spleens were excised from heparinized, freshly sacrificed donors, minced into small pieces, serially rinsed with ice-cold Hank's solution, and converted into single-cell suspensions. Nucleated cell density was determined by phase contrast microscopy following lysis of red blood cells with 1 per cent acetic acid. Cells for injection were prepared by dilution with Hank's solution (0–4°C) supplemented with 5 per cent fetal bovine serum. For each experiment, a single cell suspension was prepared at a known cell density. From it, samples were drawn for irradiation in vitro and/or in vivo. Recipients of spleen cells were exposed to x rays prior to cell injection (220 kVp; 15 mA; added filtration to give a half-value layer of 0.9 mm Cu). Surviving animals were sacrificed at eight to ten days, their spleens were excised and placed in Bouin's fixative, and nodules visible by eye were counted after fixation. Spleen cell radiosensitivity was determined in vivo by injecting graded numbers of unirradiated spleen cells into partially irradiated (610–950 rads) animals, which then received graded whole-body x-ray doses to a whole-body total irradiation dose of 900–1000 rads two hours after cell injection. In vitro radiosensitivity was determined by cell irradiation in plastic Petri dishes and assay in heavily irradiated recipients. Spleen cell CFU were more radiosensitive when irradiated in vitro (n = 0.9, D0 = 91 rads) than in vivo (n = 1.2, D0 = 109 rads) (3). To study the radiosensitivity transition, spleen cells were prepared and injected into partially irradiated animals (∼ 750 rads). Recipient animals were then irradiated with a whole-body x-ray dose of 185 rads at various times following the injection of the cells. The results of two separate experiments (Fig. 1) show that there was a decrease in the radiosensitivity of the cells beginning six to ten hours after transplantation.

Improved Method of Assay of Pyrvinium Pamoate and Its Official Preparations

A simple, rapid, and reliable assay procedure for pyrvinium pamoate and its official preparations using 80 per cent acetic acid solutions and absorption measurement at 508 mμ is presented. Results with this method are found to be more precise and can be obtained with greater facility than with the U.S.P. method. In addition a thin-layer chromatography system using Silica Gel G and dioxane-water (3:1), for the identification of pyrvinium base is described. A simple, rapid, and reliable assay procedure for pyrvinium pamoate and its official preparations using 80 per cent acetic acid solutions and absorption measurement at 508 mμ is presented. Results with this method are found to be more precise and can be obtained with greater facility than with the U.S.P. method. In addition a thin-layer chromatography system using Silica Gel G and dioxane-water (3:1), for the identification of pyrvinium base is described.

Rapid destaining of polyacrylamide gel.

WITH increasing use of polyacrylamide gel in zone-electrophoresis, the need for rapid removal of excess stain from the gel increases. The conventional destaining of the gel by washing in 5–7 per cent acetic acid may take from one to several days. This is not only inconvenient but also renders this technique unsuitable for the purification of biological substances for additional investigations.

Identification of dinitro-octylphenols in certain commercial fungicides.

A MIXTURE of nitrated alkylphenols is made by various manufacturers in the United States, Great Britain, and The Netherlands, who then esterify it with crotonic or other acid for the preparation of fungicides useful in the control of powdery mildews and also spider mites on various crops. Fractionation of this mixture, hereinafter called DNOP, on alumina (Spence type ‘H’) in benzene, followed by 2 per cent methanol in benzene, followed by 1 per cent acetic acid in 49: 1 benzene–methanol, led to the isolation of three eluates1. From each of these, amine salts were prepared and analyses showed them all to be of dinitro-octylphenols; the melting points, however, showed them all to differ from each other and also from those of 2,4-dinitro-6-n-octylphenol and 2,6-dinitro-4-n-octylphenol2. The melting points of salts of eluate II, which formed not more than 5 per cent of any of the DNOP samples, were close to those of the corresponding salts of dinocap phenol (2,4-dinitro-6-(1-methylheptyl)phenol)1,3. As the biological activities (towards powdery mildews, spider mites, and host plants) of eluates I and II were similar, and those of eluate III were dissimilar, it appeared that eluate I, which formed about 60 per cent of one sample, was likely to be another isomer of dinocap phenol, and eluate III, which formed about 25 per cent of the same sample, an isomer of 2,6-dinitro-4-octylphenol other than the n-octyl or 1-methylheptyl1,3. The 1-ethylhexyl members of both series (2,4-dinitro-6-octylphenol and 2,6-dinitro-4-octyl-phenol) have therefore been synthesized, together with the 1-ethylpentyl and 1-ethylheptyl homologues, and the isomeric 2,6-dinitro-4-(1-propylpentyl)phenol. The ethylalkyl compounds were prepared by reaction of the appropriate alkyl magnesium bromide with o- or p-hydroxypropiophenone to give the o- or p-1-hydroxyalkylphenol, respectively4. Dehydration by refluxing with toluene and a few crystals of iodine under a Dean and Stark tube yielded the alkene, which was reduced catalytically (palladium charcoal) at about 50° C under 500 lb./in.2 pressure in 4–6 h to the 1-ethylalkylphenol. Nitration was done in glacial acetic acid, and the dinitro-(1-ethylalkyl)phenols isolated as various amine salts. Salts of the 2,4-dinitro-6-(l-ethylalkyl)phenols were easily recrystallized from benzene or methanol; those of the 2,6-dinitro-compounds required cyclohexene to give a tarfree product economically. The 2,4-dinitrophenols formed suitable salts with a greater range of amines than the 2,6-dinitrophenols. Melting points and analyses are given in Table 1.

Oxide Films on Mild Steel

IT is sometimes assumed that the oxide film formed on iron at room temperatures is uniform in thickness across a specimen, and that where several oxides exist together they are present as layers stacked neatly one above the other. In an electron microscope investigation of the oxidation of mild steel using oxide films stripped by the iodine/methanol technique1 the only oxide that consistently conforms with this idea is magnetite, Fe3O4. Fig. 1 shows magnetite with its diffraction pattern on a film stripped from mild steel. The metal specimen was electropolished in a 5 per cent perchloric acid/95 per cent acetic acid mixture, washed in methanol and given no additional air exposure before the surface layer was stripped. It is interesting to note that these stripped oxide films remain quite stable if kept in a desiccator for a year and still give the same diffraction results after this length of time. Magnetite typically appears as an almost featureless layer, though with experience its presence may be recognized without examination of the very characteristic orientated arced diffraction patterns it produces. The (001) projection, as in Fig. 1, occurs most frequently although other orientations have been observed on the surface layers produced on thin foil corrosion specimens and there is evidence that the orientation changes from grain to grain. The usual difficulty in distinguishing between Fe3O4 and γ Fe2O3 was experienced in this work2 since these oxides have the same crystal structure and lattice parameters. It is noticeable that the (200) reflexions are absent and that no mixed index reflexions appear–these facts point to Fe3O4. There are, however, eight (311)3 reflexions that would not be expected and these consistently appear with this type of pattern on foils as well as on stripped oxide films. They suggest that the film is of the order of one unit cell in thickness, approximately 10 A, and that the reflexions could arise by streaking4.

Determination of Aminophylline and Phenobarbital Combinations

Procedures are presented for the analysis of theophylline (or aminophylline) and phenobarbital in various dosage forms by ion exchange chromatography and nonaqueous titration. Separation is effected on a column of Dowex 2-X8, a strong anion exchange resin. Theophylline and phenobarbital are retained by the column, while the ethylenediamine passes through with the water wash. Theophylline is eluted with 2 <i>M</i> HCl, and the phenobarbital is eluted with 50 per cent acetic acid in ethanol. Ethylenediamine is determined with standard hydrochloric acid; the theophylline and phenobarbital are determined nonaqueously with sodium methoxide in benzene-methanol.

Calcium and magnesium carbonate in some indian ocean sediments

Although many CO2 determinations have been made on deep-sea sediments there is in the literature very little information about the relative abundance of CaCO3 and MgCO3. In this investigation the contents of CaO and MgO in two per cent acetic acid extracts were determined by gravimetric methods. In view of the close agreement between the bulk CO2 contents and the CO2 equivalents of CaO and MgO in the acid extracts, it is unlikely that there was a notable addition of CaO and MgO through a partial dissolution of the clay minerals. MgCO3 varies between 0·65-4·77 per cent, whilst the rangeof CaCO3 is 1·20–88·65 per cent. The variability of the ratio CaCO3:MgCO3 in samples from localities where there is only a sea-surface average-temperature range of 2°C suggests that temperature has no major control. There are several factors which influence this ratio both before and after deposition of the test. In a genetic analysis any one of these factors should not be considered to the exclusion of the others.

Radiation effects in polyvinyl acetate

The radiation behaviour of polyvinyl acetate was investigated. A specially prepared polyvinyl acetate (pure, high molecular weight, essentially linear) was subjected to high energy gamma radiation. After 10 Mrad (the gelation dose) an insoluble network was formed and the soluble fraction decreased with increasing dose. The variation of molecular weight up to the gel point was followed by osmometry and viscosity measurements. After gelation, the course of the reaction was studied by analysis of soluble fractions, and swelling behaviour in acetone and methyl ethyl ketone. A new apparatus for making equilibrium vapour sorption measurements is described and analysed theoretically. Application of current radiation theory fairly well describes experimental results. The polymer undergoes simultaneous crosslinking and chain scission. The ratio of scission to crosslinking is 0.04 1.0 . The G value for crosslinking is 0.1 crosslinks 100 eV , as determined by molecular weight, and soluble fraction data. The G value as determined from swelling measurements is somewhat higher. Acetic acid is evolved, the amount is proportional to the total dose. This relation is given by the equation: Per cent acetic acid=1.36×10 −10( r) 0.7

METHOD FOR THE ASSAY OF ANTIDIURETIC HORMONE IN PLASMA WITH A NOTE ON THE ANTIDIURETIC TITER OF HUMAN PLASMA.

Abstract A method for the extraction and purification of antidiuretic hormone (ADH) from human plasma is described. Share's original procedure involves the trichloroacetic acid extraction of ADH from plasma, ether wash, and purification of the extract with XE-64 resin column chromatography followed by the ADH assay in water-loaded, ethanol-anesthetized rats with changes in conductivity of the urine as the index of response. This was modified by the use of 50 per cent acetic acid instead of pyridine acetate for the elution of ADH from a XE-64 resin column yielding a better recovery of ADH from plasma. ADH levels in normal human plasma averaged 1.9 μU per milliliter by this method; they were 6.5 μU per milliliter after dehydration.

CHANGES IN THE MOTOR NEURONES AFTER ADMINISTERING MUSCLE RELAXANT AND CONVULSANT DRUGS.

MATURE female rats were given 2 mg of the muscle relaxant ‘Flaxedil’ (gallamine triethiodide) repeated at intervals of 24 h for three days with full clinical recovery between doses. The animals were killed with chloroform 72 h after the last injection of ‘Flaxedil’ and the tissues fixed by perfusion of 10 per cent formalin and 5 per cent acetic acid via the aorta. The cervical and lumbar enlargements of the spinal cord were sectioned at 7µ and stained with 0.5 per cent aqueous cresyl violet to show the Nissl substance in the anterior horn nerve cells. Only the large anterior horn cells were included in the investigation.

Lipoamino-acids from Bacillus megaterium

IT has recently been reported by Macfarlane1 that lipoamino-acids are probably of general occurrence in bacteria, and that they may easily be isolated in good yield if a suitable extraction procedure is selected. It was further shown1 that these lipoamino-acids could be characterized with reasonable certainty as O-amino-acid esters of phosphatidyl-glycerol. We now report that some of the lipoamino-acid complexes obtainable from Bacillus megaterium2 appear to have this same structure. The phosphorus-containing fraction1 of Hunter and Goodsall2 was dissolved in ether and shaken at 20° for 30 min with an equal volume of N/15 sodium hydroxide (cf. Macfarlane1). This procedure reduced the nitrogen content of the ether phase from 2.5 per cent to less than 0.1 per cent. At the same time, the lipid became oxidizable by periodic acid with the formation of formaldehyde. Using 0.04 M periodic acid in chloroform–95 per cent acetic acid, 569 µg of the original lipoamino-acid complex yielded 0.69 µmole of formaldehyde after the alkaline treatment (estimated by chromotropic acid; calculation for the O-leucylester of pentadecanoylpalmitylglycerylphosphorylglycerol = 0.71 µmole). After complete hydrolysis of the lipoamino-acid complex, the only organic compound detectable apart from amino- and carboxylic-acids was glycerol, which was isolated as the crystalline tribenzoate.

Glycogen in the lens of birds' eyes.

IT is well known that the dry substance in the lens of vertebrate eyes is composed almost entirely of protein. I reported earlier1 the presence of a considerable quantity of glycogen in the lens of different species of birds. This substance was first detected with periodic acid–Schiff staining of the paper-electropherograms made from lens extract and on histological sections. Then I found that the presence of glycogen in the lens could easily be established on the agar electrophoregrams made with lens extract. After fixation in 65 per cent acid ethanol the glycogen precipitates as a characteristic white-yellowish band, which, as distinct from the protein fractions, redissolves in 2 per cent acetic acid (Fig. 1). Isolation of the substance, acid hydrolysis and chromatography confirmed the fact that I was dealing with glycogen and no other polysaccharide.

Synthese eines Tetracosapeptides mit hoher corticotroper Wirksamkeit: β1–24‐Corticotropin

AbstractThe synthesis of the tetracosapeptide β1–24‐corticotropin, containing the N‐terminal 24 amino‐acid residues of β‐corticotropin (ACTH)2), is described in detail. Many intermediates, including derivatives of the decapeptide β1–10‐corticotropin and of the tetradecapeptide β11–24‐corticotropin, were obtained in the cristalline state. A new scheme for the protection of amino and carboxyl groups in the side chains of amino‐acid residues was developed: this led to a blocked tetracosapeptide II which contains only protective groups derived from t‐butanol. These may be removed quantitatively, without formation of side‐products. β1–24‐Corticotropin (I) is thus obtained directly in an analytically pure state; [α]25 = − 88,6 ± 2° (c = 0,5 in 1 per cent acetic acid). The biological activity of the product was found to be 106 ± 14 USP‐U/mg (ACTH). It is equally active on intravenous application in human beings.

Preparation of anhydrous lanthanon acetates by desolvation

Anhydrous acetates of Y, La, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu were prepared by desolvation of the acetates in vacuum at 150°C after dissolution of the oxides in 50 per cent acetic acid and evaporation to dryness. Acetates of Pr and Nd did not reach constant composition before decomposition occurred. A hemihydrate of Sm acetate was formed which decomposed at temperatures above 150°C without converting to the anhydrous acetate. Hemihydrates of Tb and Ho were formed at about 75°C.

A study of the effect of acid and alkali on melanogenesis in the skin.

1. Twenty per cent acetic acid and a four per cent solution of sodium hydroxide were applied to the anterior abdominal wall skin of two separate groups of male guinea-pigs for five days/week/4 weeks. Each group consisted of six pure black and six pure red animals. 2. The acetic acid caused a reduction in the depth of colour of the melanin within the melanocyte cell bodies and in five of the animals a reduction in the amount of intra-cellular melanin. In seven of the animals, the length and complexity of the dendritic processes were increased. The majority of the animals showed no change in the appearances of the free melanin. A significant rise in the melanocyte count occurred. 3. The sodium hydroxide solution produced an increase in the amount of free melanin. The amount of melanin present within the melanocytes showed a tendency to become reduced. In some of the specimens areas of total epidermal destruction had occurred and in these regions dermal melanophores loaded with melanin were clearly seen. A significant rise in the melanocyte count took place.

Defence mechanisms of arthropods—I The composition and function of the spray of the whipscorpion, Mastigoproctus giganteus (Lucas) (Arachnida, Pedipalpida)

Mastigoproctus giganteus possesses a pair of voluminous glands, the secretion of which consists of 84 per cent acetic acid, 5 per cent caprylic acid, and 11 per cent water. The secretion is ejected forcibly as a finely dispersed spray that can be aimed accurately in almost all directions. It acts as a strong deterrent to predator attack, being repellent to arthropods and vertebrates alike. The presence of caprylic acid adds considerably to the effectiveness of the weapon as it is used against arthropods. By acting as a wetting agent, caprylic acid promotes the spread of the spray droplets over the cuticle of the predator, hence increasing the effective area of contact of the poison. In addition, caprylic acid exerts a marked accelerating effect on the penetration of the secretion, presumably by increasing the permeability of the epicuticular lipid barrier.

Intracellular free amino-acids of certain dermatophytes.

THE identification and classification of the dermatophytes is dependent on macroscopic and microscopic morphological characteristics developed during growth on standard media. The formulation of biochemical tests to assist in identification would be of considerable value. The work of Mattick et al. 1, which showed that extracting cells of various species of Lactobacilli with 10 per cent acetic acid removed a mixture of amino-acids and peptides from the cells which was characteristic for each species and constant for strains within a species, suggested the application of a similar technique for the identification of dermatophyte species.

Adrenaline and blood lipids.

ADRENALINE has a powerful effect on carbohydrate metabolism. The effect of this hormone on nitrogen excretion has also been studied1. However, little is known about its effect on blood lipids. In the present work, adrenaline was administered in doses of 1 mgm. to normal individuals after a 14-hr. fasting period. Blood samples were taken initially and every hour for 4 hr. after the injection. In all samples total lipids and phospholipid phosphorus were measured. For the determination of total fats the following method was used2 : 0.1 ml. of plasma was applied to a filter paper and dried. The filter paper was previously washed with alcohol/ether solution 3 : 1. The paper with the dried plasma was soaked for 60 min. in a sudan black solution (100 mgm. of the dye in 100 ml. of 50 per cent ethanol) and then washed three times for 15 min. with 50 per cent ethanol. The spots were cut and eluted in 6 ml. of 25 per cent acetic acid in ethanol. The colour density was determined at 590 µm. The results are expressed in mgm. of lipids per 100 ml. A calibration curve was prepared by using a standard solution of purified olive oil (1 per cent in a hot mixture of alcohol/ether 3 : 1). It was noticed from preliminary experiments that by this method nearly all lipids are measured. This method is more sensitive for determination of plasma lipids than visible lipaemia, and proved satisfactory for routine work.

Ayapin, scopoletin and 6,7-dimethoxycoumarin from Dendrobium thyrsiflorum (Reichb. f.).

DURING the examination of plants for phenolic constituents, the orchid Dendrobium thyrsiflorum was found to contain three highly fluorescent constituents (E. C. Bate-Smith, personal communication). The substances were extracted from a leaf hydrolysate with amyl alcohol and chromatographed on Whatman No. 1 paper using several different solvent systems. All the substances concerned fluoresce strongly a light blue-violet colour which is changed to green when the paper is sprayed with 2 N sodium hydroxide. The R F values in toluene/acetic acid/water (supernatant phase from 4 : 1 : 5 vol.) were 0.15, 0.77 and 0.85 and in 6 per cent acetic acid 0.43, 0.54 and 0.61. In Forestal solvent (hydrochloric acid/acetic acid/water) and butanol/acetic acid/water the R F values were all too high to give good separation.