Showing papers in "Nature in 1957"

Starch gel electrophoresis in a discontinous system of buffers.

Abstract: THE recently developed starch gel electrophoresis has proved to have a resolving power superior to any other type of zone electrophoresis1–4. I have applied this technique to the study of highly purified toxins3, but further work on the separated and eluted fractions of the toxin of Corynebacterium diphtheriae in tissue cultures and in animals indicated that the resolution of these proteins was not completely satisfactory in the buffer (0.03 M boric acid and 0.012 M sodium hydroxide) normally used in this type of zone electrophoresis. A more suitable system was found with a mixture of tris-(hydroxymethyl)-aminomethane-citrate (tris-citrate) used in conjunction with a boric acid buffer. Preliminary results obtained with toxins, enzymes and human sera are briefly reported here.

3,4-Dihydroxyphenylalanine and 5-Hydroxytryptophan as Reserpine Antagonists

Abstract: THE depletion by reserpine of storage in the body of 5-hydroxytryptamine (‘Serotonin’) and of the catechol amines is now well established1–3. In reserpinized animals the peripheral part of the adrenergic system does not function owing to lack of the transmitter2. This is presumably true also of the central part of the adrenergic system. However, it remains to be proved to what extent the central action of reserpine may be attributed to changes in brain catechol amines and/or 5-hydroxytryptamine.

The Structure of Turbulent Shear Flow

Abstract: The Structure of Turbulent Shear Flow By Dr. A. A. Townsend. Pp. xii + 315. 8¾ in. × 5½ in. (Cambridge: At the University Press.) 40s.

Gene Mutations in Human Hæmoglobin: the Chemical Difference Between Normal and Sickle Cell Hæmoglobin

Abstract: Gene Mutations in Human Haemoglobin: the Chemical Difference Between Normal and Sickle Cell Haemoglobin

Role of the kidney in erythropoiesis.

Abstract: RECENT observations in our laboratory indicate that the dynamic equilibrium of the erythron is controlled by the relationship of oxygen supply in the tissue to the demand for oxygen rather than by either alone. Conditions that reduce the demand for oxygen while the supply remains normal (acute starvation and the condition following hypophysectomy) and ones that increase the supply of oxygen while the demand remains normal (transfusion-induced polycythaemia and hyperoxia) all produce a profound decrease in erythropoiesis in rats. These animals give an exaggerated erythropoietic response to the injection of plasma rich in erythropoietin (anaemic plasma)1.

The Origins of Life

Abstract: N. W. PIRIE'S characteristic and entertaining account of the symposium in Moscow on the origin of life mainly consists of an exposition of his views on the subject and a metaphysical criticism of a minor part of my own contribution to the discussion.

Measure and Integral

Abstract: Mass und Integral und ihre Algebraisierung Von Prof C Caratheodory Herausgegeben von P Finsler, A Rosenthal und R Steuerwald (Lehrbucher und Monographien aus dem Gebiete der Exakten Wissenschaften Mathematische Reihe, Band 10) Pp 337 (Basel und Stuttgart: Birkhauser Verlag, 1956) 3850 francs; 3850 DM

Advances in Nuclear Physics

Abstract: Progress in Nuclear Physics Vol. 5. Edited by Prof. O. R. Frisch. (Progress Series.) Pp. vii + 325. (London and New York: Pergamon Press, Ltd., 1956.) 80s. net; 12.50 dollars.

The Atomic Nucleus

Abstract: Elementary Nuclear Theory By Prof. Hans A. Bethe and Prof. Philip Morrison. Second edition. Pp. xi + 274. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1956.) 50s. net.

A Technique for the Measurement of Lead Tolerance in Plants

Abstract: BRADSHAW reported1 that root growth was inhibited when plants of Agrostis tenuis were grown in soil from the tip of an old Welsh lead mine, while plants originally growing on the tip produced normal roots. This suggested that some plants of A. tenuis were inherently more tolerant of the lead and zinc in the soil than others. On similar waste tips in Scotland, A. tenuis is replaced by Festuca ovina and Deschampsia flexuosa, and a method has been worked out for the measurement of lead tolerance in F. ovina from soils of different lead contents.

A Detrimental Effect of Seminal Plasma on the Fertilizing Capacity of Sperm

Abstract: RABBIT sperm only develop a capacity to fertilize after spending about six hours in the uterus or Fallopian tube. This has been shown by transferring sperm from the epididymis, an ejaculum, or the uterus to the Fallopian tube1. The following experiment shows that fertilizing capacity developed in the uterus is lost when sperm is treated with seminal plasma, but can be recovered after a further period in the female tract.

Culture of tubal ova.

Abstract: MOUSE ova at the eight-celled stage consistently developed into blastulae when cultured in Krebs–Ringer bicarbonate containing glucose and crystalline bovine albumin1. It has since been shown that the bovine albumin may be replaced by egg albumin, or even by glycine (0.003 M) or other simple amino-acids and peptides. These findings indicate that mouse ova do not require any specific tubal factor at this stage, and that the conditions necessary for development closely resemble those which extend the functional life of the gametes of some marine invertebrates2.

A Suggested Statistical Model of some Time Series which occur in Nature

Abstract: THE following is an amplification and extension of some work which was described in a general way at a symposium of the Research Section of the Royal Statistical Society on Storage Problems on March 6, 1957.

Mass Isolation of Viable Wheat Embryos

Abstract: COMMERCIAL wheat germ has been a material of choice for biochemical studies ever since its use in the isolation of cytochrome c and cytochrome oxidase1. For purposes of physiological research, however, the commercial product has a serious limitation, namely, its non-viability. Samples of commercial material were tested for viability by sprinkling the germ on agar plates, or on filter paper moistened with glucose solution. Less than 0.5 per cent of the embryo-like particles showed signs of incipient germination, and none showed development of the cotyledon. Hand isolations of individual wheat embryos have been reported. Such embryos were used, for example, in mapping the intracellular distribution of hexokinase2. Hand picking, however, is a tedious and time-consuming process, and we therefore undertook to find a convenient means of preparing laboratory quantities of viable material. As a result, a simple procedure for isolating wheat embryos in relatively large amounts has been developed. One operator can prepare 200–250 gm. in a day. Chinook, a spring wheat, was found to be the most suitable of the several varieties tested.

Experimental Studies of Mimicry in some North American Butterflies

Abstract: EXPERIMENTS have been conducted to test the effectiveness of presumed mimicry in two groups of North American butterflies : (1) Danaus plexippus Linn. (model) and Limenitis archippus archippus Cram. (mimic), the monarch and viceroy respectively ; (2) Battus philenor Linn. (model) and Papilio troilus Linn., P. polyxenes Stoll, and P. glaucus Linn. (black female) (mimics).

A Method of isolating Protoplasts from Yeast

Abstract: A NEW approach to the structure and functions of the cell surface of certain bacteria was revealed when Weibull1 showed that, in the presence of sucrose, lysozyme dissolves the cell-wall, leaving the protoplast essentially intact. Various attempts have since been made to isolate protoplasts from bacteria normally insensitive to lysozyme2 and also from yeast. Thus Necas3 showed that spontaneously autolysing yeast gave rise to a small extent to structures which, superficially at least, resembled protoplasts.

Thiols, Disulphides and Thiosulphates: Some New Reactions and Possibilities in Peptide and Protein Chemistry

Abstract: Thiols, Disulphides and Thiosulphates: Some New Reactions and Possibilities in Peptide and Protein Chemistry

Crystal Structures of Silicon Nitride

Abstract: VASSILIOU and Wilde1 have recently reported a hexagonal silicon nitride, the X-ray diffraction pattern of which differs from that of the ‘orthorhombic’ silicon nitride extracted from silicon steels by Leslie, Carroll and Fisher2 After preliminary evidence of two different nitrides3, Turkdogan, Bills and Tippett4 have now definitely established the existence of two forms of silicon nitride, designated as α and β, with the same chemical compositions (Si3N4) and the same measured densities (319 ± 001 gm/ml) Even more recently, the same two phases, I and II, as observed by Vassiliou and Wilde have been claimed by Popper and Ruddlesden5 to be orthorhombic and rhombohedral respectively

Binding in Hæmoglobin Azide as Determined by Electron Resonance: Theory of Electron Resonance in Ferrihæmoglobin Azide

Abstract: Binding in Haemoglobin Azide as Determined by Electron Resonance: Theory of Electron Resonance in Ferrihaemoglobin Azide

Duration of Spermatogenesis in the Mouse

Abstract: A RISE in frequency of dominant lethals in matings at successive intervals during the first few weeks after irradiation of male mice has been observed by Brenneke1 and Hertwig2 for X-rays, and by Russell et al.3 for neutrons. Thus Bateman's4 results with exposure to 200 r. of X-rays confirm the earlier observations. Bateman's4 interpretation of his data and the subsequent discussions by Auerbach5 and Sirlin and Edwards6 concern the determination of the stage in which gametes available at successive weeks were irradiated. As emphasized by Auerbach5, and now accepted by Bateman7, Bateman's results4 do not contradict the essentially parallel response of mice and Drosophila that had been partially demonstrated in the earlier work. However, in spite of the attention this subject now has received, several points need clarification, especially in relation to the description and timing of normal Spermatogenesis in mice.

Variations in human serum beta-globulins.

Abstract: GENETICALLY controlled variations in the haptoglobins (α2-globulins) of human serum have been demonstrated by electrophoresis in starch gels1–3. The frequencies of the genes controlling these proteins probably differ from one racial group to another4. Inherited differences in the serum proteins of dairy cattle have also been established using the same method, but in cattle the variable proteins prove to be β-globulins5. The frequencies of the genes involved differ in different breeds. This communication reports variations in human serum β-globulins which have now been found.

Colominic acid, a substance of bacterial origin related to sialic acid.

Abstract: SOME years ago, it was found that a mucoprotein derived from submaxillary mucin contained an acidic component which was termed sialic acid1. More recently, it has been shown that other mucoproteins of mammalian origin contain substances closely related to sialic acid; among these are neuraminic2, gynaminic3 and lactaminic4 acids. Despite intensive chemical investigations, the structure of these various substances has not yet been fully elucidated.