Showing papers in "Annals of the New York Academy of Sciences in 1953"

Nutritional studies with chlamydomonas reinhardi

Abstract: At present, we are investigating the genetic mechanisms involved in chlorophyll biosynthesis and chloroplast development. For this project, i t has been necessary to use a unicellular organism which is photosynthetic but can also be grown in the dark, and which has a sexual phase in its life-cycle. The ability of the organism to grow in the dark has been of particular importance because of our interest in mutants unable to synthesize chlorophyll and which are therefore non-photosynthetic. The sexual requirement is necessary for carrying out the genetic analysis. The organism chosen, Chlamydomonas reinhardi, a unicellular green alga, was isolated by Professor G. M. Smith, to whom we are indebted for the mating type strains used in this work. The nutritional studies to be reported here are concerned, first, with vegetative growth of the organism in light and dark and, second, with the nutritional conditions which we have found to be of critical importance in controlling the sexual phases of the life-cycle.

Dilute solutions of branched polymers

Abstract: In an earlier era of high polymer chemistry, branching not infrequently served as a whipping boy to explain deviations from an expected physical behavior * 9 often without any independent or clear-cut evidence for the occurrence of chemical reactions leading to branched molecular structures. Today, it is clear from the general nature of the chain transfer reaction that high-conversion vinyl polymers (at least if prepared by free-radical initiation) contain more or less highly branched molecules. A sounder and more quantitative attack on the question of branching is therefore mandatory on both experimental and theoretical fronts. From the theoretical point of view, two general problems related to branching then confront us. The one concerns the mechanism and kinetics of the branchproducing reactions and ultimately the distribution of molecular weights and degrees of branching in samples prepared under specified conditions, and is illustrated by other papers3v4 in this symposium. The other concerns the effect of branching on observable physical properties, and forms the subject of this paper, It will be apparent from the previous contributions that in experimental studies of branching these two problems are not so easily separable. Our remarks are confined almost entirely to the properties of dilute solutions. It is not intended thereby to imply that the properties of polymers in bulk are insensitive to branching; on the contrary, the known or possible influences of branching on bulk properties furnish a strong practical impetus for thorough study of the subject. I t seems likely, however, that a firm theoretical understanding can be more easily and quickly attained for the properties of dilute polymer solutions than for those of the bulk materials. The properties to be discussed in the following sections are derivable from measurements of osmotic pressure, light scattering, sedimentation, diffusion and viscosity. The type of molecular structure considered is that of rather long branches, such as might occur through chain transfer reactions or copolymerization with polyfunctional monomers. Shorter, regularly spaced branches on a main backbone, such as the alkyl side groups in polyvinyl stearate, will not be treated.

The influence of the adrenal cortex on behavior of terminal vascular bed.

Abstract: Many investigators have shown that a central feature of adrenal insufficiency is the profound collapse of the circulation, which develops progressively. Swingle’ was greatly impressed with the increased capacity of the peripheral vascular tree in such cases and attributed it to a deficiency of adrenocortical secretions essential for the maintenance of “vascular tone.” Used in its broadest sense, the term encompasses many facets of vascular activity and is in no way specific. Unfortunately, the experimental data thus far available do not permit a more precise evaluation of the particular homeostatic pathways through which the adrenal cortex influences the behavior of the peripheral blood vessels. The mechanism of action of adrenal corticosteroids on the vascular system should be considered with three possible categories in view. First, does the gland produce hormones that act as blood-borne principles with a direct effect on the vascular system? Secondly, are the vascular effects referable to the basic function of the adrenal corticosteroids in the electrolyte metabolism of the smooth muscle cell? Thirdly, does the adrenal cortex influence vascular behavior indirectly through effects on other organ systems, such as the kidney? One of the most fruitful approaches to this problem is that of direct observation of the functional behavior of the capillary bed in tissues such as the mesentery under various experimental conditions.2. This approach has made it possible to relate the observed phenomena to specific structural components of the terminal vascular bed. With this as a frame of reference, one encounters less difficulty in orienting the complex behavior of the capillary circulation in its proper perspective with reference to the regulatory influence of the adrenal cortex.

Principles of nervous breakdown—schizokinesis and autokinesis

Abstract: If we speak boldly of achievement in the study of the most complex structure we know in the universe, the human mind, it is with the conviction that the few steps attained, no matter how feeble they may be, are based on the scientific and objective methodology upon which has been built the great progress of science in the last century, namely, the experimental method initiated by Galileo, which has been applied with especial ingenuity to the higher nervous activity of the living organism by Pavlov. Besides the complexity of our study of the adjustments of the human being, including his subjective life, we are confronted with another difficulty that is not shared by the other sciences today but is, almost exclusively, characteristic of our study. The difficulty I refer to is based on the subjective feelings accompanying our conscious behavior. These give us such an intimacy wit1 every movement of our skeletal frame that we are inclined to take the representation of these mental states as equivalent to the laws revealed to us by the usual scientific analysis or, at least, to confuse the relation of the subjective feelings and the objective laws, to the serious detriment of our investigations. Another disadvantage of the appraisal on the basis of subjective feelings alone is that they, being based mainly on what is revealed to our consciousness, almost entirely neglect the strong hidden current of the autonomic visceral responses. These are either vaguely or not at all represented in consciousness. Their representations, chiefly as emotional feelings, run, moreover, in our consciousness a course that is entirely different from the course revealed by the analysis of the facts obtained through a controlled scientific methodology. To those to whom it is not yet evident that the scientific methodology is appropriate for studying our psychical life and its distressing deviations, I hope this Monograph will provide at least a partial answer. During our attempt to rid ourselves of the present confusion, we must remember that the subjective feelings are of prime importance. Indeed, the objective facts have absolutely no interest for us except through their connection with our subjective feelings. The recognition of the importance of the latter does not, however, warrant the substitution of traditional subjective thinking for modern scientific methodology and analysis. In this monograph, which is devoted to the comparative conditioned neuroses in human and other animals, it would be a crass error to omit a reference to Pavlov, the discoverer of a new field of research so important for us today. More than 50 years ago, he gave a tremendous impetus to the study of phenomena that previously had been designated psychical and unsuitable for exploration by the scientific methodology. Through an accidental observation of an irregularity followed up, he ingeniously adapted a physiological method

An electron microscope study of two flagellates. chloroplast structure and variation

Abstract: The advantages of cultured protozoa as a material for growth and nutrition studies are well known and have recently been stressed by Lwoff,l Hutner and Provasoli,2 and Kidder.3 Few investigations of cultured protists, however, have tried to correlate spontaneous or induced metabolic changes with structural alterations, although the material appears particularly suitable for such studies. It would be interesting, for instance, to know what happens to the chloroplasts which exist in some flagellates, when these protozoa are adapted to life in the dark. dark-adaptation is accompanied by the disappearance of the green pigment, a fact that undoubtedly results in important modifications in the metabolic pattern of these flagellates. This problem has already been investigated by light microscopy with the conclusion that the chloroplasts disintegrate during dark-adaptation and reform when the flagellates are brought back to light. Partly because of the limited resolving power of the light microscope, however, it has not been possible to determine whether the old chloroplasts disappear completely, or how the new ones develop. The present work represents an attempt to investigate this problem by using the high resolving power of the electron microscope and by following, in parallel, the development of the green pigments and the structure of the chloroplasts during lightor dark-adaptation. Accordingly, onty preliminary observations will be presented, most of them concerning the morphological background of the problem; i .e. , the organization of the cytoplasm, chloroplasts included, as revealed by the electron microscope in the two algal flagellates we selected for our experiments.

Non-Ionic Separations with Ion Exchange Resins

Abstract: Ion exclusion has recently been described' as a new unit operation for the separation of ionic from non-ionic components in aqueous solution by use of ion exchange resins. I t provides a means for deionization without the use of chemical regenerants, depending only on the physical properties of the resin, specifically the exclusion of the ionic material from within the resin particle. In that work it was pointed out that certain large non-ionic molecular structures, e.g. sugars, could not be separated effectively from ionic materials, e.g. salt. In this paper we show that a wide spectrum of sorption and exclusion of various non-ionic materials by the resins actually occurs. This determines not only the degree of separation in ion exclusion but also, by use of the same techniques, makes possible the separation of two or more non-ionic components, I t is possible by fairly simple batch experiments to determine the insideoutside distribution constants for a given solute and a given resin under various conditions, and from these values predict the position of the elution curves and thus the loading of the resin bed and the degree of separation.

Ion exchange membranes.

Abstract: The importance of membranes in physical chemistry as well as in the biological sciences is due to their twofold character. On the one hand, membranes are restrictive barriers which selectively influence the transportation and exchange by diffusion, osmosis or otherwise of the various molecular and ionic species contained in the two compartments which are separated by the membrane. On the other hand, membranes, by virtue of their being barriers, act also as physicochemical machines which regulate the flow of the energetic processes which occur across their thickness; and, in doing this, they transform various forms of energy into others, for instance, osmotic energy into mechanical work or into electrical energy.’ Membranes which are known today to be of ion exchange character have been investigated for many decades by physical chemists, and more extensively by biologists. Virtually all the fundamental electrochemical membrane phenomena were thoroughly described and basically understood before the true underlying physical mechanism, the ion exchange nature of the membranes, was clearly realized. After the ion exchange character of electrochemically active membranes was recognized and extensive theoretical and experimental work started on this new basis, it was more than ten years before membranes prepared from conventional, commercial type ion exchanger material were described. Thus, ion exchangers of the high capacity, commercial type which, after all, are only one special class of a much larger group, are late comers in the membrane field. Up to the present, hardly a single significant, new observation has been made with a membrane prepared from the commercial type of ion exchangers which has not been described earlier and with a higher degree of accuracy. At present, numerous investigators here and abroad, using commercial type ion exchangers, are beginning to study the electrochemistry of membranes, primarily looking for technological applications. There is little doubt in the mind of the author that, in the long run, membranes, prepared with the aid of methods more or less common in ion exchange technology, will assume industrial importance? The current process of merging of the knowledge of electrochemistry of membranes with the vast body of experience in the ion exchanger field is bound to be of great mutual benefit. It is too early at present to predict where the first “big break” from an industrial point of view will come, and in which direction the membrane technology of the future will develop. The main purpose of this paper is not to indulge in speculations along these lines, but rather to present the fundamental aspects of the electrochemistry of membranes of ion exchange character; to indicate the methods of preparing

Nutrition of some phagotrophic fresh‐water chrysomonads

Abstract: The chrysomonads are a vast array of brown-pigmented fresh-water, soil, and marine flagellates. Colorless phagotrophic counterparts of several of the pigmented species are common in nature, e.g., Molzus and Oikomonus. The minimal nutritional requirements of 4 fresh-water strains belonging to 2 species are described here. No chrysomonad previously has been grown in chemically defined media. These strains ingest particulate food and are therefore animals (protozoa) and, being to some extent phototrophic, they are plants (algae) as well. They can live indefinitely in darkness or in light on high-molecular dissolved food, as well as in low-molecular chemically defined media. This extraordinary versatility, first thoroughly documented in the pioneering pure culture study of Pring~heirn,~ is accompanied by a remarkable tolerance of variations in media and exceedingly dense growth in appropriate media, including certain simple “synthetic” media [one cannot unambiguously call “synthetic” a medium containing cobalamin (vitamin Biz), whose complete structure is still to be ascertained]. This ease of cultivation-in which respect these chrysomonads contrast sharply with some of the planktonic chrysomonadslO-suggests that the biochemical basis of an intermeshed phagotrophy and phototrophy can profitably be investigated in them. PringsheimQ reviewed the scanty previous work. He demonstrated an active phagotrophy in the same strains on which the present paper is based: They ingested starch grains, oil droplets, casein particles, bacteria, and small algae -including each other. Glucose was utilized in the presence of complex natural materials such as peptone. Liver extracts were strikingly stimulatory. Dark growth was improved by aeration and paralleled that in light. Darkgrown individuals were pale. Cultures accumulated a water-soluble sepia or almost black substance which was also produced by pale growths in the dark. With chemically defined media-the subject of this paper-it should be possible to explore systematically their ability to utilize high-molecular sources of energy and carbon, nitrogen and amino acids, biotin, thiamine, and cobalamin. To identify the growth requirements of aerobic phototrophs, culture methods are needed which combine adequate illumination with freedom from significant chemical contaminations. Such considerations apply with special force to these chrysomonads. Growing densely, they need much illumination. Hence they were cultured in shallow layers of medium, and their sensitive response to certain widely-distributed growth factors such as biotin and cobalamin spurred the development of methods to minimize the confusion introduced by

Nutrition of Herpetomonas (Strigomonas) culicidarum.

Abstract: No group offers more diverse and numerous species for the study of the comparative biochemical evolution of parasitism than does the Trypanosomidae. Unfortunately, little biochemical study of this family has been possible because of the difficulty encountered in cultivation and maintenance of many ~pecies.2~~ 6 Indeed, among the pathogens some have been impossible to culture ia d r o (e.g., Trypanosoma equiperdum, Trypanosoma congolense) and, in others, where cultures have been obtained, infectivity has not always been retai11ed.2~ In view of the limited success in identifying growth factors for exacting members of the Trypansomidae,16 it was thought that other, nonpathogenic parasites found in this family, and possessing relatively simple growth requirements, would lend themselves more easily to nutritional studies. It was assumed that certain physiological characteristics would be common to both pathogenic and non-pathogenic groups, and that consequently a study of a representative of the latter group would be a stepping-stone to the identification of requirements for the more fastidious groups. The blood requirement of many trypanosomes and Leishmania has been difficult to satisfy with simpler materials. Certain parasites grow in the presence of hemin plus serum as a blood substitute (Leishmania agamae, Leishmania ceramodactyli) but many serum requirements still defy analysis15 ( c j . SprinceZ0). Herpetomonas culicidarum, a mosquito parasite in the family Trypanosomidae, has, however, a blood requirement that can be completely replaced by hemin.16 The remaining growth factors are thermostable and are found in ordinary peptones. These considerations plus the ease of handling and lack of pathogenicity made us suppose that the nutritional requirements of this parasite could be identified by procedures successful with many exacting protists. Its morphological relationship to Leishmania and to Trypanosoma cruzi indicated that its nutritional requirements might be similar in the main to both these pathogenic groups. Herpetomonas culcidarumt was first isolated by Noguchi and Tilden16 in 1926 by streaking a saline suspension of infected mosquito gut on blood agar. M. Lwoff demonstrated in 1940,15 with the aid of hydrolyzed silk, that thiamine was essential. Little work has been done since. Materials. Experimental media were contained in 25-ml. flasks incubated at 25-28OC. The total volume in each flask was 5 ml. The flasks were covered

Experimentally produced behavior reactions to food poisoning in wild and domesticated rats.

Abstract: This paper is concerned with the experimental production of changes in the rat's behavior by fear of food poisoning. Because rats can have no previous, inherent concept of the effects of poisoning, fear of poisoning must be induced. This we did by letting them eat enough poisoned food to produce marked signs of toxicity, but not enough to kill them under conditions in which, because of the quick action of the poison, they could associate the ill effects with the eating of the food or with some characteristic of the poison. Once having definitely established that the animals could recognize the poison and were thoroughly familiar with its effects, various methods of threatening them with poisoning were tried. We were unable to find records of any previous behavior experiments on effects of poisoning, and consequently had to work out our own technique. Some of the results have already been reported.\" This study is an outgrowth of work carried on during World War I1 in the search for a poison and poisoning methods that could be used on a wide scale for the quick extermination of rats, should germ warfare with rat-borne diseases be started. A highly toxic poison, alpha-naphthyl thiourea, generally known as ANTU, was developed for this purpose and found satisfactory for the particular job of quick extermination? For purposes of extermination, however, ANTU has one shortcoming of interest for the present. discussion. It was found that rats missed by a first poisoning were much more likely to escape a second attack carried out several weeks later. Often only a small proportion of Iny surviving rats were killed, whereas 90-100 per cent were killed on a first poisoning. It appeared that once having been exposed to the poison, the rats either developed a tolerance, or learned to avoid the poison, or both. Owing to the complicated nature of the conditions in the field, we were unable to delineate the mechanism there. Laboratory experiments were undertaken, therefore, to determine whether the rats do develop either a tolerance or a refusal response to this poison. From the standpoint of the practical problem of killing rats, we were interested also in learning how, once any tolerance or refusal responses have been established, they can be overcome, so that rats surviving one poisoning could be killed by a second attempt. Before presenting the results of these experiments, it will be helpful to describe a few of the physical and physiological properties of ANTU. A highly insoluble fine powder, it can readily he mixed with food or dusted on food or on the floor. For most human subjects, it has no odor, but to a few people it has a faint odor of amine. In solution and as a powder, it has a

Cortisone and infection.

Abstract: Cortisone has the property of completely disorganizing the natural hostparasite relationship, with the outcome overwhelmingly in favor of the parasite, and infection is thereby enhanced. This has been shown to be the case with many unrelated infecting agents and in many unrelated hosts.' The list of agents continues to expand: at the moment it includes pneumococci,2 tubercle ba~ i l l i ,~ streptococci,4* staphylococci,l brucellae,6 typhoid ba~ i l l i ,~ spirochaetes? trypanosomes,g Corynebacteriae,lo malaria parasites," several varieties of fungi,I2 and the viruses of poliomyelitis,13 influenza,14 Coxsackie disease,I5 and rabbit fibroma.16 The hosts in which the enhancing effect of cortisone has been demonstrated include mice, rats, hamsters, guinea pigs, rabbits, monkeys, human beings, and chick embryos. As biological phenomena go, especially phenomena that can be manipulated in the laboratory, this one has large implications. One implication has to do with the problem of mechanism or mechanisms and, since we are obliged to attempt an explanation for all of this, it is necessary to face this problem early. Are these effects of cortisone on so many different and unrelated hosts, infected by so many unrelated microorganisms, the result of one action of cortisone or of many different actions? This is a question of such central importance that it must be raised at the outset, even though it must quickly be added that we are not going to be able to answer it. I t is actually the core of the matter. For, if we are dealing with a single general action of cortisone, this would imply that there exists in nature a single defense mechanism that is common to many species of host, and governs the resistance to infection by bacteria, viruses, protozoa, and fungi. The concept of such a mechanism is not new, but the availability of an experimental model with which to approach it is, and constitutes a major advance in the field of infectious disease. In this situation, generalizations from limited data are particularly hazardous, and it is a time to handle hypotheses with prudence and caution. Before dealing with the problem of mechanism, there are several factors to be considered concerning the methods by which the effects of cortisone are demonstrated. The amounts of cortisone required to bring about lethal infection are extremely large, in terms of what one expects for the biological effects of other hormones. The point has been made that we may be dealing with something like an artifact, an unnatural pharmacological effect that bears no real relation to any physiological function of the adrenal cortex, This is a fair point, but I am not sure of its meaning. The same thing could be said of the effects of cortisone on the symptoms of The first of these is dosage.

Interruption by topical cortisone of leukocytic cycles in acute inflammation in man.

Abstract: Study of the mechanisms of the remarkable effects of cortisone and adrenocorticotropic hormone on inflammation was materially advanced by the reports of Steffensen and his associates', that the application of topical cortisone, in patients suffering with inflammatory disease of the oculus, produced antiinflammatory effects. The clinical implications of this finding have been repeatedly confirmed and e~panded.~. 4 , 5, 6 , '3 g , g , lo Experimental exploration of possible mechanisms of topical corticosteroid action has been less extensive. Blocking of the inflammatory phase of the reactions induced by the injection of jequirity or horse serum (Woods3) or by jequirity infusion or staphylococcus toxin (Woods and Wood\") when cortisone was injected locally has been reported. Leopold and his co-workers9 reported comparable inhibition of the inflammation produced with Aerobacter aerogenes, Escherichia coli, or Proteus vulgaris. Consideration of possible mechanisms of local cortisone action at a cellular level was given by Castor and Baker,12 who observed a resultant decrease in the number of dermal fibroblasts; by Dougherty,13 who counted the number of damaged fibroblasts and nonautochthonous cells as a measure of cortisone inhibition of the subcutaneous inflammation produced by histamine in adrenalectomized mice; by Shapiro, Taylor, and Ta~benhaus, '~ who noted that cortisone in a turpentine abscess produced a more necrotic leukocytic barrier and thinner granulation tissue than did turpentine alone in rats, and that ischemia or denervation did not interfere with such inhibitory effects of cortisone; and by Benjamin, Cornblatt, and Grossman,15 who noted \"less infiltration\" in their human biopsy specimens six hours after intradermal injection of adrenocortical hormones. The above observations are to be distinguished from the more extensive consideration afforded the focal action of parenterally administered ACTH and cortisone by many workers in the field whose findings will be discussed below. With attention pertaining to the mechanism of topical cortisone inhibition of inflammation so centered at a cellular level, further inquiry into the nature of such mechanisms requires a proper appreciation of the leukocytic cycles that play their part in the dynamic process that is inflammation. The basic cellular cycles of acute inflammation were first fully described by Metchnikoffl6> 17 in experimental animals. They consisted of migratory cycles of phagocytic polymorphonuclear leukocytes and lymphocytes, which latter hypertrophied to form macrophages (large phagocytic cells). These white blood cells and their derivatives were reinforced by the blood mononuclears, later called monocytes, and by tissue macrophages, later fully described by Aschoff and Kiyono's as histiocytes. This delineation of inflammatory leukocytic dynamics in experimental animals has been confirmed by Ma~imow, '~ Downey,2O Bloom,2l Watson1,22 Taliaferro and M~lligan,2~ K0louch,2~ and many others. Full reaffirma-

Purification of antibodies by means of antigens linked to ion exchange resins.

Abstract: Methods have been developed for the purification of isohemagglutinins. They also appear to be adequate for the resolution of the antibodies occurring in the 7-globulin fraction of pooled human plasma. Previously, physical chemical methods' have led to a preferential concentration of antibodies in different subfractions. Isoagglutinins, for instance, have been concentrated 16 times2 by fractional precipitation with ethanol at specified pH and ionic strength. The degree of purity of the final preparations, however, has remained less than 1 per cent. Among physical methods, electrophoresis convection appears to be the most powerful tool for the subfractionation of y-gl~bulin.~ Although a partial fractionation has been achieved, the physical chemical properties of antibodies are so similar that thus far no pure compound has been isolated solely on this basis. In an attempt to obtain specific antibodies of high purity, we have made use of the most specific precipitating agent, namely, the antigen to the corresponding antibody. Similar methods have been employed previously. They have 4 steps in common: (1) combination of the antibody with its antigen; (2) purification of the complex by removal of occluded or combined impurities; (3) dissociation of antibody from the specific precipitate or \"agglutinate\"; (4) separation of the released antibody from the solution. Whereas the first two steps have been effected with ease, methods of reversing serological reactions (step 3) have not been satisfactory. Antibodies to carbohydrates have been extracted in small yield from specific precipitates at high concentrations of sodium ~hlor ide.~ In the system egg albumin-antiegg albumin dilute acid or base has been used.5 Kabate has shown that in certain systems the dissociation of specific precipitates by barium hydroxide and barium chloride affects the physical chemical properties of the antibody. Campbell and his coworkers have demonstrated that the yield of antibodies to artifikial antigens can be increased by combining acid elution with hapten dissociation? The separation of the released antibody from the antigen (step 4) can be effected by centrifugation, when sufficient antibody remains in the precipitate to maintain the antigen insoluble. Haurowitz and his coworkerss have adsorbed antibody on a dye-antigen. The latter was insoluble at acid pH, at which the dissociation of antibody took place. Sternberger and Pressmang have devised a procedure to render antigens insoluble at alkaline pH. Campbell, Luescher and Lerman'\" have prepared an insoluble antigen by coupling bovine albumin to a derivative of cellulose. For further details on speciiic

Cation exchange processes.

Abstract: The advent of cation exchange resins which contain clearly defined functional groups of a single acid type has greatly facilitated the investigation of the nature of cation exchange processes. It is the purpose of this paper to study some of the exchange characteristics of these resins in aqueous solution and, in particular, to correlate and evaluate in a qualitative manner the selectivity data available at present. The discussion will be limited to reactions of univalent cations under equilibrium conditions, since other authors deal with polyvalent cation processesg and with the kinetics of exchange react i o n ~ . ~ ~ Cation exchange resins are high molecular weight polyacids which are virtually insoluble in aqueous and most non-aqueous media. They may be pictured as having structures containing large polar exchange groups held together by a three dimensional hydrocarbon network. In support of this picture, it has been calculated” that approximately 40 per cent of the hydrated mass of the strong acid exchanger Dowex 50 (Nalcite HCR) is due to the exchange group itself and the water associated with it. The acids which constitute the exchange groups are generally of the sulfonic, phosphonous, phosphonic, carboxylic, or phenolic types. Exchange can be ascribed to the replacement of the dissociable hydrogen ion by other cations. The number and kinds of exchange groups which are present in a resin may be determined by the “Direct Titration” technique of Gregor and Bregman.’7 This method involves weighing out resin samples in the hydrogen state into a number of test tubes and adding varying amounts of standard base along with a large excess of neutral salt to each. The mixtures are equilibrated with constant shaking, and the pH of the filtered equilibrium solution is then plotted as a function of the amount of base added per gram of oven dry weight of resin. If the direct titration of a sulfonic acid resin in the hydrogen state were attempted in the absence of neutral salt, there would be no pH change in the external solution until the end point of the titration had been reached. The reaction can be written RSOIH + NaOH = RS03Na + HzO

Neuroses in monkeys: a preliminary report of experimental observations.

Abstract: One of us’ had previously observed that when cats, dogs and other subprimates were subjected to repeated motivational conflicts they developed severe and persistent inhibitions, regressions, phobias, compulsions, organic dysfunctions, disturbances in social relationships and other aberrations of behavior which constituted various forms of experimental neuroses. During the past four years, we have extended this work to monkeys in which it has been found possible (a) to utilize conflictive “psychological” traumata in lieu of the physical ones (such as air-blasts and condenser shocks) previously employed and (b) to produce neurotic symptoms resembling even more closely those that occur in human behavior. In brief, our methods and results were as follows: Subjects and Training. In the present series of experiments, we used seven monkeys: three Asian Rhesus initially about 18 months old, two young African Vervets, and two nearly adult American Spiders. These animals had been in our colony for from eight to 18 months before inductions of neurosis. In a specially designed apparatus (see FIGURES 1-4), each animal was taught, in from four to six months, to press an electrical switch exactly four times for food, to alternate between two switches, and to choose the correct one of the two as diffeientially indicated by a bell or light signal. Further observations were made of the spontaneous behavior of each animal, both in the laboratory and home quarters, with regard to its responses to a wide variety of stimuli in all sensory modalities, including exposure to live animals or mechanically activated toys, and its interactions with cagemates and with other members of the colony. In FIGURE 1, the apparatus consists of a glass cage 36 x 25 x 20 inches with a floor of stainless steel bars set in insulating plastic and steel mesh sides leading into ventilation chambers. Entry into the central compartment is gained through a counter-weighted glass dooi a t the left, and the remaining front glass panel can be easily removed for cleaning, as can the grill floor and the pan immediately below it. The apparatus is ventilated by a blower (lower left rear) which sends a barely perceptible current of air through a carbon bank, the cage and out of the laboratory through special vents. Reward System. Two shallow boxes, into which food is automatically delivered, are located on a slanting panel a t the lower rear of the cage. These boxes are covered with hinged lids, made either of transparent plastic or of stainless steel and so designed that they can be raised easily by any small animal. A mechanism, which serves a measured amount of liquid when a lever is depressed, can also be introduced into the cage. Adjacent to each food box

Euglena and vitamin b12

Abstract: We have used mainly medium I, originally suggested by S. H. Hutner and T. H. Jukes. In addition to mineral salts and thiamine, this medium contains 0.4 per cent L-glutamic acid and 0.4 per cent DL-malic acid. The pH is about 3.0. Doubling the strength of this medium greatly increased growth, the maximum growth with the 2X solution being approximately twice the maximum with the 1X solution (FIGURE 1). A systematic examination of the constituents of medium I demonstrated that doubling the concentration of the two organic acids was as effective as doubling the strength of the entire medium. We have therefore modified our medium by adding 0.8 per cent of glutamic acid and 0.8 per cent of malic acid in place of the 0.4 per cent of each previously used. We have observed also that the condition of the inoculum is important. More satisfactory standard curves were obtained under our conditions if the inoculum was two days old. One-day or three-day old inoculum gave flatter curves and lower maxima.

Direct observations on the circulation in the hamster cheek pouch in adrenal insufficiency and experimental hypercorticalsim

Abstract: The present investigation was undertaken to study, by direct microscopy, the relationship between the functional state of vascular smooth muscle and conditions of deficiency or excess of the adrenocortical hormones, as well as the role of corticosteroids in maintenance of the integrity of the vascular endothelium. For this purpose, techniques developed in our laboratory have been utilized (Lutz, Fulton, and Akers, 1950), especially the method of transilluminating the everted cheek pouch of the golden hamster (Mesocricetus auratus) for cinephotomicrographic recording of significant changes in blood flow or blood-vessel walls, during adrenal insufficiency or during experimental hypercorticalism. Cortisone acetate and desoxycorticosterone acetate were employed as examples of the two important kinds of steroids. Electrocardiograms were recorded by means of a preamplifier (Grass Instrument Company) and oscilloscope. The sensitivity of vascular smooth muscle to electrical stimulation was determined by means of a custom-built precision stimulator (Grass Instrument Company), which permitted independent variation of voltage, duration, interval between stimuli, and frequency. Silver-glass microelectrodes (Fulton, 1941), 5 to 10 microns in diameter at the tip, were applied to the walls of arterioles with an Emerson micromanipulator (PLATE 1, FIGURES A and B). Injurious electrical shocks were used to test the integrity of the endothelium, white thromboembolism formation being the criterion for detecting the threshold for damage. The micromanipulator was used also to place micropipettes, which delivered probably less than 0.05 cc., in order to apply nor-epinephrine? directly to the walls of arterioles. The susceptibility of the blood vessels of the cheek pouch to petechial formation was tested by the application of a suction cup, 1.4 cm. in diameter, attached to a negative pressure device (PLATE 1, FIGURE C), using a modification of the method described by Shulman and co-workers (1950). Hematology was studied by the usual methods.

Studies on Polyvinyl Chloride. II. Branching

Abstract: Elucidation of the ultimate detail of high polymer structure has for no single polymer been carried to completion. The examination of gross molecular properties by measurement of the viscosities, osmotic pressures and turbidities of dilute solutions of high polymers has resulted in characterization of many polymeric systems in terms of molecular weight and molecular weight distribution. The greatest extent of polymer characterization has been along these lines. For any high polymer composed of a sequence of identical units, the possibility of several types of structural isomerism, a t a single molecular weight, exists. The arrangement of identical units may differ in the order of bond formation between the basic building units of the monomer (head to head, head to tail, or random). The examination of a number of polymers' has revealed a marked preference for the orderly head to tail type of union. In systems with conjugated double bonds, the polymerization may lead to isomers corresponding to either 1,2 or 1,4 addition of monomer units, as well as cis-trans isomerism about the double bonds in the products of 1,4 addition of conjugated dienes. Polybutadiene fine structure2 and the familiar structural isomerism distinguishing rubber and guttapercha exemplify these modes of isomerism. The incorporation of bulky side groups in the monomer may limit free rotation about the polymer backbone and yield rotational isomers. The higher alkyl polyvinyl ethers have been convincingly demonstrated by Schildknecht et a1.S to polymerize to products of restricted internal chain rotation, highly ordered when prepared at low temperatures, and randomly oriented when polymerized at higher temperatures. Finally, the build-up of three dimensional networks, by crosslinking and ramification from strictly linear chains to branched polymers, represents important structural variations. Methods for the detection and measurement of extent of structural variation have been, in some instances, highly specific, e.g., the determination of order of addition of monomer units in polyvinyl chloride by Marvel et aZ.lb Most chemical studies on polymer structure are of necessity highly specific and limited. A variety of physical techniques of more general applicability can be utilized to indicate molecular isomerism of high polymers. Structural changes usually modify polymer dimensions and shape. Physical properties which are strongly dependent on molecular dimensions, e.g. intrinsic viscosities of polym e r ~ ~ and the dissymmetry of light scattered from dilute polymer solutions,6 have been shown experimentally to deviate from established correlations with

The effect of cortisone and ACTH on the pathogenesis of tuberculosis.

Abstract: In the study of the role of sex hormones in resistance to infection, it was noted that tuberculosis in rabbits is accompanied by a marked hypertrophy of the adrenal cortex.' Furthermore, in subsequent studies, it was found that the weight of the adrenals of the natively most resistant race in our rabbit colony affected by tuberculosis caused by the human-type tubercle bacillus is much greater than that of a susceptible race similarly infected2 Therefore, investigations on the role of the adrenal cortex in resistance to the disease were undertaken to determine whether resistance can be increased by increasing adrenal function and, converscly, whether by lowering this function the native resistance can be diminished. When natively susceptible and resistant rabbits inhale a certain known number of virulent human-type tubercle bacilli, an extensive pulmonary tuberculosis is found, as a rule, five months after infection in the former, and none a t all in the latter.3 If such rabbits, thus quantitatively exposed, are killed five weeks after infection, the number of primary tubercles generated in these two types of animals is inversely proportional to their genetic resistance: the greater the resistance, the fewer the primary pulmonary foci (PLATE 1, PIGURE 1).

Growth requirements of Paramecium aurelia var. 4, stock 51.7 sensitives and killers in axenic medium.

Abstract: The nutritional requirements of only a few ciliated protozoa have been investigated successfully, especially those relating to the single genus Tetrahymena.’ Investigation of the nutritional requirements of protozoa is difficult due to the complexity of the natural habitat. Living bacteria often seem to be an absolute requirement. These bacteria may contribute labile complexes such as the “plasmoptyzate” factor for Colpoda duodenaria.2* Such factors are difficult to cope with, since they may be inactivated in the course of chemical separation, or they may be heat labile. Paramecium aurelia is routinely grown on a water extract of dessicated lettuce inoculated with Aerobacter aerogenes 24 hours before use.4 Lettuce or other plant extracts are essential since it is not possible to grow P. aurelia in a salt medium to which the bacteria have been added or in other synthetic media that support growth of Aer~bacter.~ In the lettuce medium, living bacteria are also essential. Neither the lettuce extract nor an autoclaved culture of A. aerogenes in lettuce extract will support growth of P. aurelia. This could be interpreted to mean that P. aurelia needs some heat-labile complexes for growth and that the organism has lost its capacity to satisfy these needs by synthesis. It was subsequently found, however, that P. aurelia can be grown in an axenic medium consisting of heat-stable components.6 This medium, sterilized by autoclaving, consisted of a 1 : 1 mixture of yeast extract (Basamin Busch) and a 24-hour-old culture of A. aerogenes in the lettuce extract. A heat-stable component from the yeast extract could replace a heat-labile factor present in the bacteria. This medium supported growth of P. aurelia at the rate of one to two fissions per day, which is considerably lower than can be obtained with nonaxenic culture methods (4-6 fissions per day). The low fission rate indicates that the heat-labile factor(s) contributed by the bacteria are stimulatory. The organisms could be maintained in this medium through many transfers. P. aurelia was later established in a medium developed by W. H. Johnson for the axenic culture of Paramecium multimicronucleatum.~ This consisted of pressed-yeast juice and proteose peptone. The pressed-yeast juice was found unsatisfactory for further fractionation and contained heat-labile components. The medium had one advantage, however, in that it was free of debris. From this, a medium has been developed that is composed of heat-stab!e components and is free of cellular debris. The medium consists of (A) a salt The composition is given in TABLE 1.

The coxsackie virus group.

Abstract: It seems to me that, doubtless, we must have more facts before we can hope to devise an enduring taxonomy for the Coxsackie viruses but that, without a provisional classification, we are likely to waste a good deal of effort and be delayed in assaying their role in nature. We need a uniform nomenclature to understand one another. The name “Coxsackie~’ has served well. It is a distinctive word that Westerners, a t any rate, pronounce without trouble. There is nothing in the literature with which to confuse it. It is already well established. It does not pretend to describe the diseases that the Coxsackie viruses may induce or hypothetical lesions no one has yet seen. I suggest we keep the name for a genus of viruses. The definition we originally proposed so far has withstood the challenge of subsequent observations. The Coxsackie viruses are selectively pathogenic for immature mice and hamsters, inducing in them necrosis of the skeletal muscles, with or without lesions of the brain and fat tissues. Strains are being encountered that are less selective for suckling mice than were the original types but, as yet, there is no record of freshly isolated strains that are pathogenic for adult animals. The facts that certain strains may be adapted to older animals, that older animals are more susceptible following cortisone treatment, and that limited organic lesions may be induced in older mice by certain strains do not, it seems to me, seriously challenge the propriety of the definition. They only show how much of an alchemist the modern virologist has become. So far as the record goes, age susceptibility plus the morbid response in test animals still stand as a serviceable definition. It is well known, of course, that immature mice are much more susceptible than adult ones to many viruses, but I know of no virus, other than those producing Coxsackie lesions, that is pathogenic only for young animals and, so far, of none that has as striking an age selectivity. It may well be that there will be others, but they are still to be described. In this connection, it may be noted that the lesion of fat has never been observed in other circumstances. It may be quite specific. Subdivision of the Coxsackie group seems to me to be both desirable and sensible. We have long suspected that the distinction between those strains that produce generalized muscle necrosis, and those that produce scattered muscle necrosis plus encephalomalacia and lesions of the fat pads might prove to be of practical importance. Anyone who has worked with both varieties knows that the behavior of the sick mice is quite different. Visitors to our animal quarters who have known only one kind have no difficulty in deciding whether their strains are A’s or B’s once they see the two side by side. The two groups differ in other respects. The Group-A strains are easily isolated, while the Group-B strains are troublesome at times. Sometimes the latter are

Effect of certain corticosteroids and of growth hormone of nucleoproteins of lymph nodes.

Abstract: One of the most striking and consistent anatomic changes that follow the administration of adrenocorticotropic hormone or cortisone to experimental animals is atrophy of lymphoid tissue. Because such tissue represents a large repository of nucleic acids in the body, the effect of adrenocortical steroids on the nucleic acid content of lymph nodes was investigated. The popliteal lymph nodes of rabbits are discrete and easily obtained, and were, therefore, used as the test system. The effects of various steroids and other hormones on the wet weights of carefully trimmed popliteal lymph nodes of male rabbits weighing 2.5-3.5 kg. are shown in FIGURE 1. All hormones were administered intramuscularly or subcutaneously in five daily doses and the nodes were obtained 24 hours after the last injection. The mean weight of normal popliteal nodes is 178 mg., and twice the standard deviation of the mean of control lymph nodes is charted. Cortisone, in the usual suspending medium, or as a crude saline suspension, led to significant atrophy of the nodes. Purified corticotropin obtained from Drs. E. B. Astwood and M. S. Raben was administered in oil and beeswax, and this preparation also caused atrophy of the nodes. A long-acting Armour preparation of ACTH was not effective in inducing atrophy and, instead, seemed to induce hyperplastic changes. Kecent experiments suggest that this may have been a rebound effect due to insufficient dosage of ACTH and that larger doses or more frequent administration of the gel suspension of ACTH may induce atrophy of the nodes. The administration of hydrocortisone induced lymphoid atrophy. The free alcohol was more effective in this respect than the acetate, presumably because of slow hydrolysis of the latter. Corticosterone caused the nodes to become hyperplastic, and growth hormone alone induced mild and probably insignificant hyperplasia. Growth hormone given in combination with either cortisone or hydrocortisone did not reverse the effect of the steroids and, when given with corticosterone, overcame the effect of that steroid in inducing mild hyperplasia. Homogenates of the lymph nodes were analyzed for contents of desoxypentose and pentose nucleic acids by the methods of Schmidt and Thannhauser and of Schneider. Only phosphorus values are given on the charts but, in most instances, duplicate analyses for the carbohydrate content of the nucleic acids were also conducted, with good general agreement between the carbohydrate and phosphorus analyses. Although the data, as presented, relate to the wet weights of the lymph nodes, analyses of the nitrogen content of the homogenates showed a relatively fixed ratio of wet weight to nitrogen. Cortisone (FIGURE 2) has no significant effect on the concentration of DNA, despite the marked lysis of lymphocytes and the disintegration of nuclei that