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Abscopal Effects of Localized Irradiation by Accelerator Beams
The aim of this series of experiments was to evaluate the existence of abscopal effects of irradiation. No attempt was made towards the elucidation of mechanisms. Very early in the history of radiological research it was noticed radiation produces both local and general effects involving the entire body. Gauss and Lembcke introduced the term "Roentgenkater" (radiation sickness). They ascribed these "General Effects" to the circulation of toxic substances released from cells that disintegrated following irradiation.
Adaptation of a Commercial Counter X-Ray Diffractometer for Investigations to 3000°C
The rapid advances in many technologically important areas have not only served to accentuate the increased demands for high temperature metals and ceramics but have necessitated a more through knowledge of their physical properties when exposed to high temperature service. Toward this latter end, the use of X-ray diffraction has proved an invaluable tool in providing data of regions of thermal stability, expansion coefficients, solid solubility limits, and phase transformations by direct examination at temperature. Since this Laboratory has for some time now been engaged in the study of refractory nuclear materials, it was thought desirable to employ and possibly extend this technique to temperatures ranging up to 3000°C. This communication will describe the equipment developed for this purpose, with experimental results to be described in subsequent publications.
Adenosinetriphosphate Cleavage During the G-Actin to F-Actin Transformation and the Binding of Adenosinetriphosphate to F-Actin
Since the discovery of the Straub and Feuer as well as Laki et al. that ATP bound to G-actin is transformed to ADP and inorganic phosphate during polymerization of actin (1, 2), it has become increasingly clear that the chemical changes in the nucleotide are related to the change in the physical state of the protein. Barany, Biro, Molnar and Straub have shown that highly purified actin preparation free of any enzyme which would use ATP, ADP or AMP as a substrate still catalyze the breakdown of ATP (3) thus supporting the original idea that the ATP to ADP transformation is related to the globular to fibrous transformation of the actin protein itself. Mommaerts was the first to show that the ADP formed during polymerization remains bound to F-actin and Ulbrecht et al. while extending Mommaert's finding on exhaustively purified actin preparations have shown that the P1 formed during polymerization is not bound to F-actin. The stoichiometry of the splitting and the tightness of binding of the ADP lead inevitably to questions in regard to the position of bond breaking during the hydrolysis and to the nature of the forces involved in the tight binding of ADP to F-actin. To aid in the clarification of these problems, this study using O18 isotope was initiated.
AGS Performance and Plans
The scope of the AGS complex has expanded rapidly during the three years since an accelerated beam was first obtained. Demand for research time far exceeds the amount available although facilities have been much increased. At the same time, experiments are being designed which are more complicated than previous ones and which make more stringent demands on the accelerator and on its auxiliary equipment. There is a continuous trend of experiments to particle beams of greater momentum, as the experimental techniques are refined. This use of increased momentum means that larger areas are required for the apparatus and that more power is necessary for the magnetic optics. All beam-sharing at the AGS is done by multiple use of each accelerated pulse because our experience indicates that pulse-by-pulse beam-sharing is relatively inefficient. (Expansion chambers have seldom been used at the AGS.) The problems of scheduling experiments becomes increasingly complex since combinations must be found satisfying the criteria: maximum number of experiments to run simultaneously; minimum downtime to be taken for rearrangement between successive experimental arrays
Alternating Gradient Magnets
The angle by which a magnet deflects the trajectory of a particle in the x-z plane is proportional to the integral [integral not transcribed] taken over the trajectory wherever B≠0. Alternating gradient focusing is achieved by designing magnets so that I=I(x) varies linearly with x over a suitable x interval. Usually this is done by shaping the poles to give a linear variation of By with x while keeping the length of the magnet constant for different x. Certain advantaged may be gained by varying the effective length of the magnet with x and keeping By constant so that the integral varies properly with x. Figure 1 shows several such poles for which the trajectory length, and hence the integral (1), varies approximately from 2/3 to 4/3 of the mean value.
Antibody Formation by Transplanted Bone Marrow, Spleen, Lymph Node and Thymus Cells in Irradiated Recipients
The role of the marrow as a site for antibody formation has been considered for many years. In 1912 Ludke reported the appearance of antibody in cultures of marrow cells obtained from previously immunized rabbits. Specific agglutinins for killed typhoid bacilli and lysins for ox red cells and sheep red cells were detected in the culture media 2 to 5 days later. However, the cultured cells failed to produce antibody when these antigens were added to the media. Similar findings by Reiter, Przygode, and Schilf appeared in the early literature with regard to the appearance of antibodies to various antigens in tissue cultures of bone marrow from immunized animals, along with failure to elicit antibody formation by addition of antigen to the culture resulted from the addition of excess amounts of antigen, so that if antibody synthesis occurred, the excess antigen combined with antibody and significant amounts of free antibody could not be detected in the culture media. Thorbecke and Keuning observed an increase in antibody in culture fluids when bone marrow fragments from rabbits immunized to paratyphoid B vaccine were cultured in roller tubes.
Automatic Bubble Density Measurement with the Hough-Powell System
The Brookhaven Bubble Chamber Group is developing a Hough-Powell fast analysis system (HPD)1 for bubble chamber photographs. High precision measurements are made with a computer controlled flying spot digitizer. We are currently testing the track selection programs for the system. We have just completed a study of a method for automatic bubble density measurements.
Beam Separators for Bev Particles
The problem of separation of beams of particles of different masses but of the same momentum at Bev energies is the subject of a great deal of study at several high energy laboratories. In this note we shall describe the problem and tabulate a few of the cogent parameters. Frequently the student of high energy interactions is faced with a beam of miscellaneous particles coming from an accelerator. By standard techniques this beam can be rendered approximately parallel and an inch or so in diameter. By passage through a magnetic field the beam can be analyzed in momentum. Now it frequently happens that the particles in which the experimenter is particularly interested make up only a small fraction of the beam and the exigencies of the proposed experiment may well demand that the background of undesired particles be drastically reduced. The problem is difficult because the velocities of the various particles are almost equal to each other and to the velocity of lights; this makes time-of-flight techniques relatively ineffective. The energies of the particles are almost equal so electrostatic separation also is difficult. Since the beam is already analyzed in momentum, further separation by magnetic means is impossible.
Bromine Exchange in Graphite-Bromine Lamellar Compounds
A kinetic study of the exchange of normal and radioactive bromine in graphite-bromine lamellar compounds has been made at temperatures of 30° to 50°C. Natural and synthetic graphite powders were investigated. Two alternative mechanisms for the exchange, volume diffusion and surface exchange, were considered. The data were in better agreement with the diffusion mechanism. Diffusion coefficients of 10 -9 to 10 -8 cm2/sec and an activation energy of 11 to 14 kcal/mole were calculated for the natural graphite powders. The diffusion coefficients increased with increasing bromine content. Reversibly absorbed bromine exchanged more rapidly than irreversibly absorbed bromine.
The Calculation of Zero-Point Energies of Molecules by Perturbation Methods
Two methods are proposed for calculating zero-point energies of molecules. The first makes use of the fact that one can easily write down the quantum mechanical Hamiltonian for a vibration system. The zero-point energy can then be obtained by a perturbation scheme without solving the secular equation. The second method requires a knowledge of the normal modes and frequencies of a reference molecule, but then enables one to calculate isotope effects by a perturbation scheme. The methods are applied to some examples and the convergence of the perturbation series is investigated. The approximate validity of the law of the mean for the isotope effect on zero-point energies is explored within the framework of the methods.
Cell Population Kinetics of an Osteogenetic Tissue, I
Cell proliferation on the actively growing periosteal surface of the femur of rabbits aged two weeks, has been investigated using autoradiographic techniques. Injections of tritiated glycine and tritiated thymidine were given simultaneously and the animals sacrificed at intervals from one hour to 5 days after injection. The glycine labelled the position of the bone surface at the time of injection and the thymidine labelled the cells which were synthesizing DNA . The rate of increase in the cell population was determined by counting the number of cells beyond the glycine label at different times after injection. The cell kinetics of the fibroblast--pre-osteoblast--osteoblast--osteocyte system has been studied. The fibroblasts are relatively unimportant from the point of view of increase in the cell population. The main site of cell proliferation is the layer of preosteoblasts on the periosteal surface. The rate of movement of cells from the pre-osteoblast to the osteoblast and osteocyte compartments has been measured. The incorporation of osteoblasts into the bone is not a random process, but it appears that the osteoblast must spend a certain time on the periosteal surface before becoming either an osteocyte or a relatively inactive osteoblast lining a haversian canal. During its most active period on the periosteal surface it was estimated that on an average, an osteoblast produces 2 or 3 times its own volume of matrix.
Cell Population Kinetics of an Osteogenetic Tissue, II
A study of the cell kinetics on the actively growing periosteal surface of the femur of rabbits ages two weeks has been continues. A single injection of tritiated thymidine was given and the rabbits killed from one hour to four days after injection. The grain count spectra of the different cell types, pre-osteoblast, osteoblast and osteocyte, have been compared at different times after injection. The results showed evidence for the uptake of thymidine in nuclei which is not associated with cell division. A small percentage of osteoblasts was initially labelled at one hour and there was evidence that the majority of these had not divided by 3 or 4 days after injection. Some thymidine labelled cells had also become osteocytes without division. Furthermore, it appeared that a considerable fraction of the initially labelled pre-osteoblasts did not divide. The S-period for the pre-osteoblasts and osteoblasts was measured using a double-labelled thymidine technique.
The Cellular Differences Between Acute and Chronic Neutron and Gamma Ray Irradiation in Mice
It has been well established that even small doses of radiation will shorten life expectancy of animals, and that in general the causes of death are the same for the irradiated as for the normal animals. When x or γ rays are compared with neutrons in their ability to shorten the life span, some interesting differences appear. All available data from different laboratories on the shortening of the life span by x or γ on the one hand and neutrons on the other, have been compared. In spite of the obvious difficulties in comparing such data, if one expresses dose in terms of the LD 50/30 dose required for acute survival, one can pool the data from other laboratories and plot them on a single graph without excessive error. Results of such a compilation for single acute exposures are shown for x or γ rays in Figure 1 and for neutrons in Figure 2.
Chronic Excess Salt Consumption as an Etiologic Factor in Human Hypertension
Since 1940 it has been known that extra salt (i.e. sodium chloride) facilitated the development of experimental hypertension induced by various sterols; subsequently hypertension was induced by desoxycorticosterone acetate plus sodium chloride; then hypertension was produced by using hypertonic saline as the sole source of liquid; and finally, in 1953, Menesly and his associates reported that chronic ingestion of excess dietary salt alone would produce hypertension in rats. Furthermore, in conformity with general pharmacologic experience relating dose response to successive increments of a drug, as the average daily salt intake increased, the average systolic, blood pressure increased.
Cobalt-60 Bulk Grain Irradiator: Study Report
Report issued by the Brookhaven National Laboratory discussing bulk grain irradiators. As stated in the abstract, "this report presents the results of a study to conceive, evaluate, review and estimate costs for a number of suitable designs for a Cobalt-60 Bulk Grain Irradiator; select a preferred type; and establish required criteria for future detail design and construction of the selected concept" (p. ii). This report includes tables, and illustrations.
Crystal Structure of a Sodium Cobalt Molybdate
The cobalt and molybdenum positions had been derived from a three-dimensional Patterson function based on complete data out to λ-1 sin θMo≈ 1. From the separation of the separation of the Mo atoms it was thought that the structure contained free, unlinked MoO4 -2 ions, and this, together with the observed density and analyses for Co and Mo, suggested that the composition was probably Co2(MoO4)3. The paucity of structural information on complex oxide systems and the interesting properties, both structural and physical, of such systems prompted the present, detailed refinement of the structure. The result is more complicated and more interesting than had been anticipated: from the analysis of the X-ray data the compound is found to be NaCo2.31(MoO4)3, and this composition is consistent with chemical analyses. The structure shows several interesting features, including the partial occupancy of cobalt atoms in two independent CoO6 octahedral sites. In one arrangement of CoO6 octahedra there is the not too common face sharing to form infinite columns; in the other arrangement a zig-zag sheet, as far as we know differing from anything thus far reported, is formed by the sharing of edges and corners.
Cytochemistry of Delayed Radionecrosis of the Murine Spinal Cord
In the vast field of radiation pathology we find pathologists, anatomists, and even physiologists busily at work, but the radiobiologist is conspicuously absent, although, according to Zirkle (1959), this field is clearly within his domain. Perhaps it is wise to take this broad hint of the scientifically so well equipped radiobiologist and to stay clear from an area in which an incalculable array of variables makes clearcut experimentation a hopeless venture, a priori. Perhaps it would be better if the pathologist, who must study pertinent material, restricts himself humbly to the recording of his observations, refraining from any attempt at interpretation. On the other hand, since seemingly audacious speculation has borne fruit in the past and the value of the information that results, if the speculation proves to be correct, is worth many times the effort, there is obvious justification for a thesis on the mechanism of delayed radionecrosis.
Determination of the Single Interstitial Migration Energy From Stored Energy and Thermal Resistivity Changes in Irradiated Graphite
The model used to evaluate the single interstitial migration energy from property changes due to interstitials is extended to account for vacancy contributions. The annealing function obtained can be used to determine the relative contributions of the defects and is sufficiently sensitive to distinguish vacancy effects that are an order of magnitude less than interstitial effects. Application of the model to stored energy and thermal resistivity data yields the same values of the activation energy and temperature independent term obtained from c-axis and macroscopic length expansion rates. The results indicate that the stored energy associated with the di-interstitial is at least ten times greater than the stored energy associated with the vacancy. The minor role of vacancies in phonon scattering is discussed. Analysis of the annealing function obtained from electrical resistivity changes in irradiated graphite indicates that the ratios of charge-carriers to scattering centers varies with irradiation temperature below 55°C. Above this temperature the changes are attributed to equal contributions from vacancies and interstitials.
Di-Interstitial Annealing During the First Neutron Irradiation of Graphite: The Mobility of C2
Radiation and annealing mechanisms for dimensional and c-axis changes in which the di-interstitial can be mobile at any or all temperatures above absolute zero are shown to be concordant with earlier work used to determine the migration energy energy of single interstitials and the absolute rate of displacing atoms in graphite. The mechanisms account for the stability of c-axis and dimensional changes with time in the absence of irradiation and with observed c-axis annealing at room temperature following irradiation at low temperatures.
Effect of Long-Range Interactions on Order
Harrison and Paskin (HP) have calculated the ordering energy of β-CuZn using recent theoretical techniques of treating electron screening and Mott's polar model of an alloy. Good agreement is obtained between the calculated total energy of the order-disorder transformation and specific heat measurements. A consequence of the HP calculation is that the ordering energy is long-range and oscillates in sign. Walker and Keating recently measured the neutron diffuse scattering of β-CuZn above the critical temperature Tc and find their data is in agreement with order calculated by only considering a nearest neighbor interaction. Using the Cowley statistical theory of order, we compare the order generated by a nearest-neighbor interaction and the long-range interaction of HP at a temperature 1.1Tc. we find the average behavior of the order generated by the nearest-neighbor and long range interaction to be similar, The major difference is the nearest-neighbor interaction generates order that asymptotically, varies smoothly with neighbor distance whereas the order resulting from the long-range interaction fluctuates markedly about the nearest-neighbor generated order. This result may explain the success of statistical theories, based on nearest-neighbor interactions, in both order-disorder of alloys as well as in some magnetic systems which are also believed to have a similar long-range oscillatory interaction.
The Effect of Mitotic Cycle Duration on Chromosome Breakage in Meristematic Cells of Pisum Sativum
One of the more apparent differences between acute and chronic irradiation is that exposure in the former is generally confined to a small fraction of a single mitotic cycle while in the latter; exposure of mitotically active tissue usually involves at least several cycles. Because of this difference, the number of cells in each stage of interphase would be of primary importance in acute radiation experiments since radiosensitivity is not the same in the G1, S and G2 periods. The duration of the total mitotic cycle should be more important in chronic experiments because most of the cells in the tissue will have passed through each of the interphase stages (G1, S and G2) during the period of irradiation thus negating any different effect.
The Effects of 2.0 BeV Protons in Mice
The Brookhaven proton synchrotron (Cosmotron) is capable of accelerating protons to energies as high as 3.0 BeV. The biologic effects of particle bombardment at these energies have not been investigated but are of considerable radiobiologic interest. In addition, particle beams have long been discussed with regard to their potential usefulness in medical therapy, and actual clinical applications have been made, although at lower particle energies. Recent rapid advances in space technology have raised serious questions regarding the dosimetry of cosmic and solar radiations, the spectra of which contain energies in excess of those which have been investigated experimentally. For all of these reasons, we have recently begun a study of the effects of protons at 2.0-2.2 BeV, using the external beam of the Cosmotron.
The Effects of 250-kv X-Ray on the Dog's Pancreas: Morphological and Functional Changes
Previous investigations that the pancreas is a radioresistant organ. Ivy in 1924 noted the presence of a fibrotic atrophic pancreas in a dog which had received one erythema dose to the epigastrium. Fisher in 1923 reported that four to five erythema doses delivered in a single application caused complete disappearance of the irradiated pancreatic remnant in about two months. These dogs died because of uncontrolled diabetes. One dog that received four erythema doses (possibly 200 r) was sacrificed after five months. At autopsy the irradiated pancreas had disappeared, but 275 mgm of regenerated pancreas were found at the base of the main duct and 100 mgm at the base of the accessory duct. Leven in 1933 implanted radon seeds into the pancreas. Dosages varied from 528 to 1584 millicurie hours. At postmorten the pancreas surrounding the seeds demonstrated fibrous atropy and foci of necrosis. The islets appeared normal but were relatively larger in size. Rauch in 1952 reported that dogs given 200 r in air over the pancreas on alternate days until a total of 1600 r was received failed to show any histological changes after two months. Lushbaugh and Spalding and Lushbaugh reported that over 1500 r of whole-body gamma irradiation were required to produce histologic changes in alpha cells in 8 hours, and over 5000 r to produce changes in the beta cells in the same time. These changes had disappeared by 24 hours.
Effects of Chronic Excess Salt Ingestion: Possible Implications of the Accelerated Induction of Experimental Hypertension by 2,4-Dinitrophenol
Recently, we reported that the administration of the thyroid hormone, L-triiodothyronine (T3), markedly accelerated the development of experimental hypertension associated with a high-salt intake in intact rate. Earlier, Selye and his associates and Masson, Corcoran, and Page has observed a similar effect from thyroxin in uninephrectomized salt-fed rats. We were aware of the fact that oxidative phosphorylation is uncoupled by the thyroid hormone and were intrigued by the possibility that such uncoupling was instrumental in the accelerated development of the hypertension observed. The work reported here was undertaken with this possibility in mind; it was based on the well documented observation of Loomis and Lipmann that dinitrophenol reversibly inhabits oxidative phosphorylation. The present studies indicates that 2, 4-dinitrophenol, like L-triiodothyronine, can also rapidly induce hypertension in salt-fed rate. These observations have led us to develop a working hypothesis that may have general implications relative to the pathogenesis of hypertension in man.
The Effects of Chronic Gamma Irradiation on the Growth of Kalanchoe cv. "Brilliant Star"
Kalanchoe seedlings were exposed to 330 r/20 hrs/day from a Co60 source. Samples were harvested weekly. No new leaves were produced after initial exposure to irradiation. Mitosis in the apical meristem appears to have been suppressed. However, the axillary meristem and the cambium continue their activity. This results in a much broadened stem tip with enlarged cells, supported by a stout internode in which cell size has remained relatively normal but cell number has increased. After about 26 days of exposure, meristematic activity in the shoot apex region appears to resume. This results in the formation of growth centers which can give rise to leaves or malformed structures. The original phyllotaxy is not recovered. It is suggested that this resumption of growth may be an instance of adaptation to irradiation.
Effects of Low Levels of X-Rays and Irradiation from C14 and H3 on Cell Population Kinetics in the Root Tip of Tradescantia
Reciprocal labelling in double-labelling experiments with H3- and C14- thymidine showed that when H3- thymidine (1μc/ml for 0.5 hr) was given first in the labelling sequence followed by a 4 hr interval before the C14- thymidine treatment, that passage of cells into and out of DNA synthesis was normal. When C14 was first in the sequence, the rate at which cells entered DNA synthesis was decreased. This was attributed to a radiation effect produced by the β-rays from the C14. The rate at which cells entered DNA synthesis was studied after 0.1, 1 and 10 rads of x-rays. A dose of 1 and 10 rads decidedly depressed the rate. Treatment of roots with 2, 20, and 200 μc/ml of tritiated water for 0.5 hr showed that the 2 higher concentrations produced an effect similar to the x-rays. This indicated that somewhere between 1 and 8 disintegrations per cell per 0.5 hr will produce a decrease in the rate at which cells enter DNA synthesis. In both the x-ray and H32O experiments the depression of the rate that cells entered DNA synthesis seemed to reach saturation at the higher doses.
The Effects of Radiations of Different let on Early Responses in the Mammal
This paper will first note briefly the place and status of radiobiotopical investigations with fast neutrons. The monoenergetic (fast) neutron technique employed at this laboratory will be then described and results of studies with various criteria-of-effect in the mouse will be reviewed. Finally, certain general patterns of response for these systems will be pointed out as functions of neutron energy.
Effects of Trichinella Spiralis Infection on Incorporation of Amino Acids into Serum and Hemoglobin
Encysted Trichinella spiralis larvae incorporated carbon-14 from mice fed diets containing C14 -labeled glycerine and DL-alanine. In general, a higher level of C14 activity (C14 per gram of dry tissue) was found in muscle larvae than in muscle tissue. The presence of encysted Trichinella larvae in the muscles of 56-day and 180-day infected mice did not alter incorporation of C14 from these amino acids into infected muscle protein when compared with noninfected muscle. These experiments were extended to include the aromatic amino acids, DL-tyrosine and DL-tryptophan.
Electric Currents, Membranes, and Biological Sources of Electromotive Force
The analysis of closed circuit systems in which spontaneous steady-state electric currents appear can be carried out with the use of the function [function not transcribed]. The analysis indicates that any open circuit system of the form. Phase 1, barrier 1, phase 2, ......, phase b, barrier b, phase 1' is a chemical source of electromotive force when the phase 1 and 1' are identical, when the system contains two or more barriers whose sets of ionic transport members are different, and when the system is composed of two or more phases whose chemical properties are different. A general expression for the electromotive force of model systems composed of homogeneous phases and biological membranes in linear array can be written as [expression not transcribed] in which the indicated summations are to be performed for all barriers and for all ions to which each barrier is permeable.
Elimination of Phases the Life Cycle of Leukemic Cells From in Vivo Labeling in Human Beings With Tritiated Thymidine
Our earlier in vitro studies have suggested that malignant tumors may not produce new cells more rapidly than normal cells are produced in the "steady state" equilibrium. Obviously tumors of all typed represent a diversion from "steady state" production with a net gain in mass of tissue. However, the increase in mass is not necessarily constant and may fluctuate in the natural history of the disorder. DNA labeling with tritiated thymidine had made it possible to characterize normal "steady state" hemopoietic growth parameters. We therefore thought it mandatory to extend these techniques to the study of growth rates of human leukemic cells. Also, since current therapy is more or less closely tied to a concept of unrestrained rapid growth, which we in part have begun to question, it appeared wise to look back at the historical development of knowledge about tumor growth. The existence of tumors in man has been known for millenia.
Evaluation of Mitotic Time in Vivo, Using Tritiated Thymidine as a Cell Marker: Successive Labeling with Time of Separate MItotic Phases
The duration of mitosis is of great importance in an evaluation of growth rates in proliferating somatic tissues, since calculations are based on observations of mitotic activity, and therefore final results are directly proportional to an assumed value for mitotic time. This duration cannot be measured directly in vivo at a tissue level, since the mode of distribution of the single cell value is not known. This difficulty is not overcome in extrapolations from in vitro measurements. Also it is not overcome with the labeling of proliferating cells after tritiated thymidine injection in vivo if subsequent observation is limited to the rate of progression into mitosis of labeled cells that incorporated the tracer during the period of DNA-synthesis. Observation of separate mitotic phases, however, offers the possibility of following the progression of the wave of labeled cells at successive, short-lasting checking steps, and to analyze the variability in the times of passage through mitosis. In the present work, the progression of labeled cells as a function of time, after a single injection of tritiated thymidine, was followed in successive phases of mitosis in erythroblasts of dog bone marrow.
The Fate of Transfused H3 Thymidine Labeled Bone Marrow Cells in Irradiated Recipients
It has been established by chromosome marker studies, histochemical, immunological, and cytological methods that the hemopoietic tissues of animals exposed to lethal doses of whole-body irradiation can be repopulated by transfused autologous, homologous or heterologous bone marrow cells. However, the morphology of the cell responsible for the regeneration of hematopoietic activity in the various hemopoietic organs has not been identified. It has been shown that the bone marrow contains the cell or cells capable of regenerating all types of hemopoietic tissues. In order to identify transfused cells, one must have a label which persists through successive divisions. Odell and Smith labeled the donors with S35 methionin and were thus able to follow the accumulation of the donor marrow cells in the recipients lungs and subsequently their releases to the bone marrow and spleen. However, this compound has a relatively rapid turnover in the labeled cells and thus a relatively limited capability of serial studies to observe mitosis and differentiation. Tritiated thymidine is ideal for this purpose since it is incorporated solely into DNA and is diluted only by mitosis. In addition the high resolution with tritium makes it certain that one is observing nuclear labeling. Bond et al. have studied the migration of labeled cells from a non-irradiated parabiotic rat to the irradiated member. Nagal and Knisely have studied the fate of in vitro labeled autologous and homologous bone marrow cells after transfusion into two patients. Balner et al have labeled bone marrow cells in vivo with H3TDR and transfused these labeled cells into irradiated homologous newborn mice and studied their distribution as a function of time following transfusion by [unintelligible] of autoradiography.
Fluorimetric Assay of α-Chymotrypsin
The enzymolysis by α-chymotrypsin of the substrates, N-acetyl-L-tryptophane ethyl ester and N-acetyl-L-tyrosine ethyl ester, was followed by means of fluorescence whose intensity increased fourfold and threefold per mole respectively as substrate was transformed into amino acid. The assay by fluorescence was several orders of magnitude more sensitive than the assay by differential absorption spectra of these substances and was in agreement with it in those concentration regions where both methods overlap. To maintain linearity between concentration and fluorescence intensity, the concentration of substrate should be no greater than 10-4 M/1. In such solutions the rate of esterolysis could be followed with the enzyme at 10-11 M/1.
Four Short Articles on Genetics of Maize
Studies carried on since 1956 indicate that the prosaic breeding procedure of sibbing among the most perennial segregates in the hybrid of 4n maize x 4n perennial teosinte quickly restores perennialism to 50% maize tetraploids through increasing the expression of the rhizomatous habit under selection pressure. Similarly, only two generations of selection at the 75% maize level have resulted in a progressive recovery of the perennial expressive. A high degree of maize-likeness therefore appears to be compatible with the perennial expression at the 4n level.
The Function of Bridging Groups in Electron-Transfer Reactions
Electron-transfer reactions involving bridged transition states are examined from the point of view of adiabatic electron transfer theory. One important function of the bridging group is to decrease the effective dipole moment of the charge system of the reaction ions. The effect on the activation energy is different for outer-sphere and inner-sphere reactions. Trends in the halide and hydroxide catalysis of isotopic exchange reactions of transition metal ions are discussed.
Fundamental Problem of Late Neurological EffectFollowing Acute Irradiation
Since the end of the last century (Tarknow, 1896) radiation effect o the nervous tissue has been studied in experimental animals and humans by numerous investigators, using mostly pathomorphological changes as a parameter of radiosensitivity . With increasing time intervals following radiation, pathomorphological changes are more evident, which has been known for quite some time.
Fundamentals of Vacuum Technology
Vacuum technology is germaine to and is utilized in an extroardinarily widespread scope of the scientific disciplines. From the medical technician freeze drying hog cholera vaccine to the solid state physicist studying thin film phenomena, vacuum technology is an important auxiliary. When one visits the NASA center at Langley and sees the clustered space environmental chambers, looking like a field of grotesque mushrooms, one realizes that vacuum technology is a vital adjunct in this most recent section of our total national scientific effort.
Gene Structure: Genetic Fine Structure. Remarks.
Though only recently established, this concept has been developing for a long time. More than thirty years ago Dubinin, Serebrovsky, and other, investigating the phenotypes of a number of "achaete-scute" alleles of Drosophilia melanogaster, found that the alleles could be arranged in a definite series accoding to bristle patters, and also that the heterozygotes lacked only those bristles which were affected in common by both participating alleles. They concluded that the serial classification of alleles according to bristle patters had its counterpart in a similar arrangement of portions of the achaete-scute gene locus. On this assumption they divided the locus into twelve elementary subunits. It was assumed that each allele arose by a change involving a certain combination of these centres. According to their theory, the achaete-scute locus is made up of separate, regularly spaced, and linearly arranged functional units. Several years later, Oliver described the occurrence of crossing over between two alleles of the "lozenge" locus. Then Green and a number of other workers analyzed similar phenomena in different regions of Drosophila chromosome. During the same period Lewis developed the theory of pseudoallelism, which interprets the occurrence of recombinants in interallelic crosses as the result of gene duplications. Thus for more than three decades evidence has gradually been building up to indicate that the gene might not be the basic unit of recombination; but until recently it did not serve to convince the large majority of those interested in genic composition.
Hematological Effects of Whole Body Irradiation
The development of nuclear arms added the effects of ionizing radiation to the direct and indirect mechanical, chemical or thermal hazards of "conventional" weapons. The biological effects of ionizing radiation are the result of absorption of energy and the morphologically recognizable damage is poorly understood. Although new in their use in weapons and difficult to evaluate in their consequences, ionizing radiations are by no means new to physicians. Furthermore, medical experience has shown that clinical consequences of radiation injury are similar to those with which the clinician has to deal with every day in the treatment of neoplastic disorders and its complications. Soon after the discovery of x-rays by Roentgen and of the phenomenon of radioactivity by Bequerrel in the last decade of the last decade of the 19th century, it was found that ionizing radiation can produce marked biological effects by interfering with cell- and organ functions. Senn and Hussey were the first to effectively treat leukemia by this means. This, since about 60 years, ionizing radiation has been a powerful tool in the hands of physicians both in diagnostic procedures and for therapy of malignant disease. It should not be forgotten however, that the price paid for this contribution of outstanding importance was high. Long before any nuclear weapons were used, a long list of fatalities and injuries among physicians, investigators, technicians and nurses, witnessed the possible consequences of radiation exposure. However, the number of lives saved through the use of ionizing radiation exceed greatly the number of lives ever lost through the harmful effects of radiation.
High-Pressure Gamma Loop for Brookhaven National Laboratory
Report issued by the Brookhaven National Laboratory discussing high-pressured gamma loops. As stated in the introduction, "this latest endeavor involved three test cells, a gamma irradiation pool and supporting equipment, as well as an enlarged high-pressure gamma loop facility" (p. 1). This report includes tables, and illustrations.
The History of the Brookhaven Biology Department Mouse Colony No. 1 (Swiss-Bridge-Bagg-O'Grady-Walter Reed Strain) With Endemic Occult Cerebral Encephalitozoönosis and Colony No. 2
Innes, Zemen, Frenkel, Borner and Wright (1962) described an outbreak of encephalitozoönosis of the central nervous system in mice, a summary of which is given below for an understanding of why this appendix may be of interest. When the paper was presented for publication, the editors of the journal decided to omit the history of our mouse colony. In our opinion, to understand (a) how this infection may have arisen and (b) may have spread, and still exist in some colonies, it is of prime importance to know the history of this strain of mice used by us (and others). It also has lessons on the establishment and maintenance of so-called "disease-free" or "specific pathogen-free"* colonies of laboratory animals in general. Information on the history of the mice has been culled from Col. H. Yager, VC, Director of the Division of Veterinary Medicine, Walter Reed Army Institute of Medical Research, Washington, D. C., and from Drs, Clara Lynch and John B. Nelson, Rockefeller Institute, New York.
Hot-Atom Chemistry of the Solid StateL its History, Current Status and Future Prospects viewed in Relation to the Planning of Chemical Research Programs for New Scientific Establishments Centered about a Research Reactor
The History, Current Significance and Status of the Field Hot atom chemistry, like many other fields of scientific research, can trace its origin to a single experiment, that of Szilard and Chalmers, performed in 1934. This is true even though recoil effects had been known and used for a long time. Almost immediately Szilard and Chalmers put their discovery to practical use: they employed the recoil effect in ethyl iodide as a neutron detector and observed the γ,n reaction in beryllium. The ingenuity of Fermi soon provided the correct explanation of the chemical separation observed by Szilard and Chalmers, and Fermi's co-workers, especially D'Agostino put the effect to a further practical use: the preparation of radioisotopes in high specific activity. These Roman scientists carried out the first Szilard-Chalmers studies in solids (sodium bromate, chlorate, iodate, and perchlorate, cacodylic acid and potassium permanganate) and reported some quantitative results: for example a quite accurate recoil yield of 80% of the Mn 56 in potassium permanganate. Perhaps the most striking practical result of a Szilard-Chalmers experiment lay in the discovery, by Kourtchatow and co-workers, of the important isotope Br 82 in extracts from neutron-irradiated ethyl bromide.
Human Radiation Injury - a Correlation of Leukocyte Depression with Mortality in the Japanese Exposed to the Atomic Bombs
The method of collection and the subsequent analysis of the hematological data accumulated by the Joint Commission of the Investigation of the Early Effects of the Atomic Bomb in Japan, have been described. In the present investigations, an additional analysis of the hematological data was made to investigate a possible relationship between leukopenia and the mortality rate within the first nine weeks following the bombings. It has been frequently observed in laboratory animals exposed to ionizing radiation that the extent of the fall in the white blood count reflects the dose of radiation received. Smith et al have demonstrated that in mice survival can be related to the depression of the granulocyte count at various times following radiation. Cronkite and Brecher and Cronkite, Bond and Dunham inferred that the hematological response could be used as a biologic dosimeter for exposed human beings. This report is concerned with the study of the response of the white blood cells to ionizing radiation resulting from the atomic bomb detonation in Japan.
The Hydrolysis of Orosomucoid with Trypsin
In recent years a good deal of understanding about the structure of the α-acid glycoprotein of human plasma (orosomucoid) has been obtained. Since the isolation of the protein in an apparently pure state, it has been shown to have a molecular weight of approximately 45000 and to be made up of about 40% carbohydrate and 60% polypeptide. The latter apparently is in the form of a single polypeptide chain. The carbohydrate, on the other hand, has been shown to have at least 16 non-reducing chain ends terminating in sialic acid, and may also have 1-3 further chains with fucose on the non-reducing end. At least in those chains terminating in sialic acid, galactose is in the next position followed by N-acetyl glucosamine. The recent report of the isolation, from a partial acid hydrolysate of the α-glycoprotein, of an octasaccharide containing 2 residues each of galactose and mannose, and 4 residues of N-acetylglucosamine, indicates that at least part of the carbohydrate in the protein is the form of units no smaller than this. However, the number and nature of the firm covalent linkages between carbohydrate and protein remain uncertain, and it was for this reason that the present study was undertaken.
Improved Growth of Etiolated Pisum Seedlings for Bioessays by the Use of a Complete Chelated Nutrient Solution
Tissue from etiolated or partially etiolated Pisum seedlings is widely used in work on growth substances and light responses. However, in the authors' experience growth under the conditions commonly employed is frequently irregular, and often affords little or no satisfactory experimental material. Although the literature records little evidence of such difficulties, personal communication with many investigators leaves no doubt they are widespread.
Indirect Effect of X-Radiation on Bone Growth in Rats
It has been known for many years that bone growth may be retarded by relatively large doses of therapeutic radiation. Similar doses of radiation have also shown retarded growth in animals. More recently, reports of studies of Japanese children exposed to the Atomic Bomb Detentions at Hiroshima and Nagasaki and Marshallese children exposed to radiation in the fallout accident of 1954 have indicated some impairment in their growth and development, possibly related to radiation exposure. Since the doses of radiation received by these children were lower than would be expected to produce retardation of bone growth by direct irradiation, it was considered that indirect mechanisms might play a part. This preliminary report summarizes investigations of possible indirect effects of X-irradiation in bone growth in rats.
Inelastic Interactions of 11.4 Bec/c π" Mesons in Hydrogen
Production cross sections and angular distributions of Λ and K° particles produced by 11.4 Bev/c π" mesons in hydrogen have been measured. A systematic investigation was made of all two-body decays of unstable neutral particles. No events inconsistent with γ, Λ, or K° were found. Production cross sections, angular distributions and effective mass distributions of π mesons produced in 4-prong events were also measured. No evidence for dominance of any high mass multi-pion resonance was found. Both the pion production and strange particle production reactions demonstrated peripheral characteristics in that the baryon was strongly peaked backward in the center of mass. The average transverse momentum was observed to be a monotonically increasing function of mass. The experimental total interaction cross section was 25.3 ± 1.5 mb. The effect of the pion-nucleon T ' 3/2 isobar was clearly observed.
The Influence of the Centromere of Chromosome Fragment Frequency Under Chronic Irradiation
Studies on a large variety of plant species, particularly by Sparrow and his colleagues, have shown that radiosensitivity, as measured by growth inhibition and lethality, is strongly correlated with various parameters of the cell nucleus. Foremost among these are nuclear volume, SNA content and chromosome number. It is generally accepted that in proliferating cell systems chromosome damage may well be the principal radiobiological lesion, and the observed correlations are in line with the contention that loss of genetic materials following such fragmentation is a factor of a major importance in radiation-induced lethality and growth inhibition in plants.
Interactions of High Energy Antiprotons in Hydrogen
In the fall of 1961 an extensive program of investigation of high energy p-p interactions was begun at the Brookhaven AGS. The BNL 20" liquid hydrogen bubble chamber and an electrostatically separated beam were used to obtain a total (to date) of 300,000 exposure with about 15 antiprotons per pulse. The exposures were made at antiproton momenta of 3.25 Bev/c and 3.69 Bev/c in the laboratory. Approximately 80% of the exposures were made 3.69 Bev/c antiprotons. A wide variety of reactions occur in these collisions. Some of these such as elastic scattering, pion production, and associated production of hyperons and K-mesons have analogues in p-p collisions. The similarities and differences between the p-p and p-p results can usually be understood in a qualitative way and in some cases quantitative comparison with theory has been possible. The annihilation reactions leading to final states containing pions alone or pions with K-mesons are unique to the nucleon-antinucleon system as are the reactions in which a hyperon, anti-hyperon pair is produced. In the following, we report the principal characteristics of proton-antiproton reactions. Although the scope of this paper is comprehensive it is not a definitive report of the experiment as much of the work is still in progress.
Internal Target System and Induced Radioactivity at the AGS
When the Brookhaven AGS started operation in the summer of 1960 very little experience with targeting in strong focusing proton synchrotrons was available. While it was evident that targeting techniques would differ markedly from those used in weak focusing machines, only actual running experience would set the proper parameters for a truly satisfactory targeting system. It was, therefore, an advantage that temporary targeting devices were used initially. Work on a more permanent system was not started until the summer of 1961, and the first component of the system installed in January 1962. While further refinements are still continuing the essential features of this targeting system have now sufficiently proven themselves in actual operation to remain unchanged. This system in its present form is the subject of the first portion of this paper.
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