Heat-stable Fraction Research Articles

Chemical composition of the nematode cuticle. Observations on individual layers and extracts from these layers in Ascaris lumbricoides cuticle

1. (1) Evidence is submitted which indicates that the cuticle of Ascaris lumbricoides is secreted collagen and that the external cortical layer consists of a tanned protein, the outermost part of which is covered by a thin lipid layer. 2. (2) Peptic hydrolysis breaks down the fiber and homogenous layers in Ascaris and tryptic hydrolysis breaks down the homogenous layer and substances binding the fiber layers. 3. (3) The individual layers of Ascaris cuticle show similarities in amino acid composition, but quantitative differences for some amino acids were observed. 4. (4) The water soluble protein of Ascaris cuticle appears to consist of two heat coagulable fractions and three heat stable fractions. These proteins appear to have similar molecular weights. 5. (5) The differences between insect cuticle water soluble protein and Ascaris cuticle water soluble protein are outlined. 6. (6) Evidence in favor of nematode cuticle secretion involving the subcuticle and lateral lines is put forward and compared with that available in favor of Chitwood's “condensation” theory.

NUTRITIONAL STUDIES ON THE AMOEBO-FLAGELLATE, TETRAMITUS ROSTRATUS

1. Tetramitus was cultivated indefinitely under axenic conditions upon a medium consisting of 0.5% Difco yeast extract, 0.5% Difco peptone and 1.0% Wilson liver concentrate (N.F.) with selected types of a autoclaved bacteria.2. The liver concentrate could be eliminated with subsequent reduction in trophic growth, only if killed B. cereus or. B. subtilis was utilized as the bacterial fraction. Other bacteria (Neisseria catarrhalis, Escherichia coli) could not be substituted for these spore-formers in this medium.3. It was found that the B. cereus cell contained at least two heat-stable fractions necessary for growth; neutral hydrolysis yielded a non-dialyzable fraction found in the cell-residue and a dialyzable fraction found in the bacterial cell supernatant.4. Both factors were stable to autoclaving with 0.1 N HCl for 30 minutes at 15 pounds pressure and were retained in the acid-treated cell-residue. Alkaline hydrolysis destroyed activity of all the fractions.5. Preliminary attempts have failed to subst...

The Role of Heat-Stable Antigen in Serological Identification of Proteolytic Clostridia

Summary It is suggested that the somatic antigen of the proteolytic Clostridia be regarded as made up of a heat-stable and a heat-labile fraction. The heat-stable fraction of the 4 cultures studied was identical with that of group III organisms. The heat-labile fraction was identical with that of group II organisms. According to the reactions of the heat-stable fraction the organisms described were placed in group III; given the formula Prot. Cl. III: 5, 6 and identified as a new serotype of Clostridium parabotulinum.

THE RENAL PATHOLOGY OF NUTRITIONAL HYPERTENSION IN RATS

Rats subsisting on a diet partially deficient in the heat-stable fractions of the vitamin B complex are known to experience a rise in blood pressure. The present study shows that after prolonged administration of this dietary, abnormal structural changes occur in the kidneys. The surface of this organ becomes finely granular. The afferent arterioles show degenerative changes, consisting of irregular subendothelial hyaline deposits which encroach on the lumen. The interlobular arteries undergo the same change, plus degeneration of the media; the lumen of these vessels is likewise compromised. Resultant, small, streak-like areas of ischemic atrophy occur in both cortex and medulla, with necrosis of the epithelial lining of the uriniferous tubules. The glomeruli are reduced in size, the number of their component loops decreased, their pattern simplified, and the capillary basement membrane thickened. In addition to these changes, kidneys from animals on a more profoundly deficient diet display numerous areas of hemorrhagic infiltration in the cortical and subcapsular regions. The possible identity of these lesions with those seen in essential hypertension in man is discussed.

NUTRITIONAL DEFICIENCIES AS A CAUSE OF ELEVATED BLOOD PRESSURE IN RATS (WITH ESPECIAL REFERENCE TO THE VITAMIN B2 COMPLEX)

The effects of dietary deficiencies on the blood pressure of rats were studied, with especial reference to vitamin B deficiencies. A deficiency of the entire vitamin B complex was followed by a slight fall in blood pressure. A deficiency of only thse heat-stable fractions was followed by a significant and persistent rise in pressure, which could be reversed by restoring these factors to the diet. Partial deficiencies were followed by a higher rise of blood pressure than were complete deficiencies, perhaps because of the debilitating effects of the latter. Even an excessive intake of the heat-stable fractions of the vitamin B complex did not prevent entirely a rise of pressure if the diet was otherwise deficient. Under the latter conditions, the rise in pressure was slower and less marked than in those animals with a deficiency of the vitamin B(2) complex only. It therefore appears that, while a deficiency of the vitamin B(2) complex plays a dominant rôle in causing a rise of blood pressure in rats, other dietary factors as yet undefined are also involved. From analogy with other deficiency states, it is possible that thsese undefined nutritional factors cause their effects by interfering with absorption and utilization of the vitamin B(2) complex.

NUTRITIONAL DERMATOSES IN THE RAT VI. THE EFFECT OF PANTOTHENIC ACID DEFICIENCY

Signs of deficiency, including cutaneous alterations, occur in rats and chicks which are fed purified diets low in the vitamin complex and supplemented with the synthetic forms of thiamine, riboflavin, nicotinic acid and pyridoxine (vitamin B6). If whole liver or yeast is substituted for the four vitamins there are no signs of deficiency. Therefore there are additional members of the vitamin complex in the natural foodstuffs. One of these has been identified as pantothenic acid. Fractionation of water-soluble vitamin B was originally accomplished by autoclaving whole yeast.1By this procedure the antineuritic fraction, vitamin B1(thiamine), was destroyed, but the growth-promoting, antidermatitic, heat-stable fraction, vitamin B2(vitamin G), was unaffected. Later other methods of separation were introduced. Biologically active fractions were obtained in crude adsorbates, eluates and precipitates which were prepared from aqueous extracts of foods rich in the complex. Treatment of whole liver

The Nutritional Approach to Experimental Dermatology. Nutritional Dermatoses in the Rat: I. Vitamin B6 Deficiency

The first carefully studied experimental nutritional dermatosis associated with deficiency of the Vitamin B complex was that formerly called pellagra. This was described in 1926 by Goldberger and Lillie (3) who fed rats a diet similar to the diets of pellagrins. The lesion they produced consisted chiefly of a bilaterally symmetric, erythematous, scaly dermatitis (pellagra-like) involving the peripheral portions of the body. Occasionally this was accompanied by dermatitis and alopecia of the head and trunk. These skin changes were prevented and cured by feeding autoclavcd yeast; thus it appeared that yeast contained the pellagra preventing vitamin. In 1928 Chick and Roscoc (4) suspected that there was more than one dermatitis preventing factor. However, the multiple nature of the heat stable fraction of the vitamin B complex was not appreciated until riboflavin was isolated in 1933 (5). Gyorgy was the first to demonstrate that riboflavin failed to cure the socallcd pellagra-likc lesion in the which responded, however, to a vitamin which he named B6 (6, 7). He suggested the term rat ncrodynia in place of pellagra because of the gross resemblance to human acrodynia (Pink disease, Swift-Feer disease, Erythredcma). On the other hand the skin symptoms which he found to be associated with riboflavin deficiency appeared irregularly, were often mild, and consisted chiefly of a generalized scaling and symmetric patches of nlopccia on the trunk and the head. Subsequent work on the components of the B complex has resulted in the isolation and synthesis of several other vitamins and the preparation of various biologically active concentrates. The filtrate factor components and nicotinic acid are now recognized members of the vitamin B complex. Oleson, et al. (8) have attributed spectacle alopecia to the deficiency of n component of the filtrate,

Production of Canine Blacktongue on Purified Diets

Goldberger and coworkers produced the canine disease black-tongue, on diets consisting principally of natural foodstuffs (largely corn, cow peas, and casein). They believed that the ability of certain foodstuffs to prevent the disease was due to their content of a specific heat-stable component of the vitamin B complex identical with the human pellagra-preventive (P-P) factor. The P-P factor has been rather generally considered to be identical with the rat factor, vitamin G (B2). Certain doubts have been cast on this view of the production of blacktongue. Zimmerman and Buraek maintained dogs on an “artificial, balanced ration adequate in all dietary essentials as far as is known except water-soluble, heat-stable vitamin B2 (G),” and these dogs did not develop blacktongue but a different disease. Rhoads and Miller also reported that they were unable to produce blacktongue by feeding diets lacking in G (B2). It has even been suggested that blacktongue is due to multiple deficiencies of the Goldberger diet rather than to lack of a specific vitamin. The demonstration of the multiple nature of the heat-stable fraction of the B complex has led to an explanation of some of these discrepancies. Birch, György, and Harris fed 4 dogs on a “synthetic” basal ration, complete except for the B complex, supplemented with lactoflavin [now known to be the rat factor, vitamin G (B2)] and highly purified vitamin B (B1). Typical blacktongue appeared in each dog, proving conclusively that blacktongue is due to lack of some member of the vitamin B complex other than B (B1) or G (B2). At the time of the appearance of the above work I had nearly completed an independent investigation on the production of blacktongue on “synthetic” diets. Four dogs were fed the following basal ration which is complete except for B vitamins: purified casein 19 parts, glucose 66, salt mixture (Osborne-Mendel) 4, cottonseed oil 8, and cod liver oil 3 parts.

Anticomplementary Action of Purified Heparin.

The writers, in a previous paper, reported on the anticomplementary action of heparin. It was found that the antihemolytic effect is not due to an action upon the erythrocytes. Although an ancillary action upon amboceptor could not be excluded, the action was found to be upon the complement. Further investigation demonstrated that the anticomplementary effect of heparin is due to its interference with the heat-stable factor or the so-called third component of complement. Complement inactivated by heat and by NH3, containing in both instances the third component, reactivates heparin-inactivated complement. Previous admixture of a small amount of calcium to heparin destroys its anticomplementary activity without interfering with its anticoagulant action. It was found that a large amount of heparin is required to inhibit complement, many times the dose that will render a corresponding amount of blood incoagulable. This is also pointed out by Hyde. Intracardiac injections of guinea pigs with as much as 50 mgm. of heparin led to incoagulability of the blood without impairment of complement titer. An anticomplementary action of heparin is reported by Fuchs and Hartman. Prof. Howell's announcement of the preparation of N-free heparin, suggested an investigation to determine whether or not the anticomplementary power is due to heparin per se or to the impurities associated with it. Furthermore, the possibility that the anticoagulant effect and the anticomplementary power depend upon 2 different mechanisms also indicated more work in that direction. Through the courtesy of Prof. Howell, who kindly prepared for us a small amount of purified heparin, and to whom we are much indebted, we are enabled to report results obtained with the purified product. The anticomplementary power of purified heparin was retained and the action was again found to be upon the heat stable fraction of the complement. Complement, inactivated by heat and by NH3, reactivates the complement inactivated by purified heparin. While 0.18 mgm. of the crude heparin inactivated one unit of complement, 0.013-0.018 mgm. of the purified product produced the same effect. The anticomplementary power of the purified heparin was increased about 10 fold.