Showing papers in "Nature in 1959"
TL;DR: It is shown that the sexual attractants of butterflies are, like hormones, produced and secreted by special glands; minute amounts cause a specific reaction in the receptor organ, which eventually leads to a state of copulative readiness.
Abstract: DURING the past few decades, investigations have been made into various active substances which, though they resemble hormones in some respects, cannot be included among them. For example, the sexual attractants of butterflies are, like hormones, produced and secreted by special glands; minute amounts cause a specific reaction in the receptor organ (the antenna of the male), which eventually leads to a state of copulative readiness. Unlike hormones, however, the substance is not secreted into the blood but outside the body; it does not serve humoral correlation within the organism but communication between individuals.
1,250 citations
TL;DR: It has been found that human insulin cross-reacts strongly with insulin-binding antibodies in guinea pigs immunized with crystalline beef insulin, and that guinea pig anti-beef insulin serum has characteristics suitable for the detection and measurement of human insulin at concentrations which exist in the plasma of normal fasting subjects.
Abstract: WE have previously reported on the immuno-assay of beef insulin and certain other animal insulins, employing antiserums from human subjects treated with commercial mixtures of beef and pork insulin1. The insulin-binding antibodies present in these anti-serums do not form precipitable complexes with insulin, but with the use of insulin labelled with iodine-131 the complexes are readily demonstrable by paper chromatography and electrophoresis2. Beef, pork, sheep and horse insulins can be assayed quantitatively by measurement of the degree of competitive inhibition of binding of any insulin labelled with iodine-1311–3. As might have been anticipated, however, human insulin competes too weakly in systems employing human antiserum to be measurable at concentrations which obtain in vivo. Furthermore, the lack of availability of significant quantities of pure human insulin precludes its use as an antigen for animal immunization. However, in the present work, it has been found that human insulin cross-reacts strongly with insulin-binding antibodies in guinea pigs immunized with crystalline beef insulin, and that guinea pig anti-beef insulin serum has characteristics suitable for the detection and measurement of human insulin at concentrations which exist in the plasma of normal fasting subjects.
995 citations
TL;DR: The alkali denaturation method of Singer, Chernoff and Singer gives a spectrophotometric reading of 0.5–1.8 per cent ‘alkali resistant hæmoglobin’, but most of this residue is not true fœtal hâmoglobin, but some other hæM-compound, the nature of which is unknown.
Abstract: IN the alkali denaturation method of Singer, Chernoff and Singer1 the one-minute residue of normal adult haemoglobin gives a spectrophotometric reading of 0.5–1.8 per cent ‘alkali resistant haemoglobin’. It is well known1,2,3, that most of this residue is not true fœtal haemoglobin, but some other haem-compound, the nature of which is unknown.
977 citations
TL;DR: The method is based on a column procedure similar to chromatography in which the stationary phase is comprised of a new type of gel which consists of hydrophilic chains which are cross-linked.
Abstract: We wish to report a simple and rapid method for the fractionation of water-soluble substances. The method is based on a column procedure similar to chromatography in which the stationary phase is comprised of a new type of gel. These gels consist of hydrophilic chains which are cross-linked. They are devoid of ionic groups, the polar character being almost entirely due to the high content of hydroxyl groups. While water-insoluble, the gels are never-theless capable of considerable swelling. The fractionation depends primarily on differences in molecular size although phenomena have been observed which indicate the influence of other factors.
973 citations
972 citations
TL;DR: This communication reports the protective action of dimethyl sulphoxide against freezing damage to human and bovine red blood cells and to bull spermatozoa.
Abstract: Polge, Smith and Parkes1 first reported the protective action of glycerol against the adverse effects on spermatozoa of freezing and thawing. Lovelock2 found that the protective action of glycerol was shared with a number of other neutral solutes of low molecular weight, including methanol, acetamide and glyceryl monoacetate. Using the extent of haemolysis of red blood-cells as a measure of damage by freezing, it was concluded that the principal protective action of the neutral solutes was a simple consequence of their ability to prevent the excessive concentration of electrolytes and other substances that otherwise occurs on freezing. The protective property is limited to substances that are in themselves not toxic, have a low molecular weight, a high solubility in aqueous electrolyte solutions and an ability to permeate living cells. The number of solutes capable of fulfilling these conditions is small, and so far glycerol most closely approaches the ideal protective agent. Some cells, however, are impermeable to glycerol, for example, bovine red blood cells, and with these glycerol is of little use in their preservation by cold storage. An alternative solute with a greater permeability to living cells is dimethyl sulphoxide. This communication reports the protective action of dimethyl sulphoxide against freezing damage to human and bovine red blood cells and to bull spermatozoa.
874 citations
777 citations
TL;DR: This report describes an experiment designed to determine the life- span of single yeast cells and includes consideration of possible mechanisms for life-span limitation.
Abstract: THE division of a yeast cell by budding gives rise to two cells which are identifiable, that is, the mother cell from which the bud arose, and the daughter cell which developed from the bud. The wall of the daughter cell presumably is synthesized de novo while that of the mother cell retains all or at least part of its identity through the division—an example of linear inheritance1. That the wall of the mother cell is not reformed is evidenced by the accumulation of scars associated with each budding event2. Electron micrographs3–5 reveal a scar area that is approximately 1 per cent of the surface area of the cells. If, as indicated by Barton2, a bud is never formed at the site of a scar, then it is possible that the life-span of individual cells would be limited by depletion of available budding sites. Barton observed one cell to bud 23 times but did not observe a cessation of budding. Other progressive changes also might limit the number of divisions that a single cell can complete. This report describes an experiment designed to determine the life-span of single yeast cells and includes consideration of possible mechanisms for life-span limitation.
749 citations
TL;DR: Control experiments showed that the same effect was produced by dosage with inert material or even without any treatment other than the introduction of a strange male at 24 hr. after mating.
Abstract: EXPERIMENTS on the effect of certain oral progestogens during early pregnancy, in continuation of previous observations1 on non-pregnant animals, involved placing a recently mated female receiving oral progestogen with a strange male. In a number of the mice the procedure resulted in failure of pregnancy from the first mating and a new mating within 3–6 days. Control experiments showed that the same effect was produced by dosage with inert material or even without any treatment other than the introduction of a strange male at 24 hr. after mating. 20 out of 49 females behaved in this way, a far greater proportion than could be attributed to the expected incidence of anovular cycles. Only about 8 per cent of young females, as used, return to œstrus within 4–5 days if removed from the male after their first mating, or copulate again at this time if they are left with the male. Moreover, among the suspect females there was a failure of the pseudo-pregnancy which might have been due to poor stud males. Experiments were therefore undertaken to explore this effect.
714 citations
TL;DR: In this article, the angular factor of a solid rotating about an axis making an angle α with the applied field is expressed as the sum of its mean value, where α is the angle between the internuclear vector and the axis of rotation, and ωr is the angular frequency of rotation.
Abstract: THE nuclear magnetic resonance spectrum of a solid rotated at high speed consists of a narrowed central line and a set of side-spectra spaced at integral multiples of the rotation rate of either side1,2. The interaction energy between each pair on nuclear magnets in the solid contains the angular factor (3 cos2θ – 1), where θ is the angle between the internuclear vector and the applied field. When the solid rotates about an axis making an angle α with the applied field, the angular factor may be expressed3 as the sum of its mean value ½ (3 cos2 α – 1) (3 cos2 γ – 1), where γ is the angle between the internuclear vector and the axis of rotation, and two time-dependent terms, (3/2) sin 2α sin 2γ cos ωr
t, and (3/2) sin2 α sin2 γ cos 2 ωr
t, where ωr is the angular frequency of rotation. The two time-dependent terms lead to the formation of the side-spectra. It should be noted that when α is 90°, as in our earlier experiments1,2, the first of these terms is absent, so that side-spectra occur in this case at even multiples of ωr only ; for general α, the side-spectra occur at odd and even multiples of ωr. The form of the mean value of the angular factor for each nuclear pair leads to the conclusion that the central spectrum should have the shape found for the static crystal when the applied field is directed along the axis of rotation, but reduced in width by the factor ½ (3 cos2 α – 1), and having a second moment4 reduced by a factor ¼ (3 cos2 α – 1)2. Thus, in particular, when α has the value cos−1 (1/√3) = 54° 44′, the dipolar broadening of the central line should be removed5. With a speed of rotation large compared with the static line-width, the side-spectra will be displaced far from the centre and will be weak, leaving only a sharp central line broadened by residual non-dipolar causes.
TL;DR: In this paper, a neutral aqueous suspension of cellulose crystallites by hydrolysis in strong sulphuric acid (952 gm/l.) at 30 or 40° C. has been described.
Abstract: THE preparation of a neutral aqueous suspension of cellulose crystallites by hydrolysis in strong sulphuric acid (952 gm./l.) at 30 or 40° C. for 24 hr. has been described1. A similar suspension of crystallite particles of chitin was prepared by treating 20 gm. of purified chitin from crab shells for 1 hr. in 750 ml. of 2.5 N hydrochloric acid under reflux. Afterwards, the excess acid was decanted and distilled water was added. At this stage, the chitin hydrolysate was still essentially a sediment and was well on the acid side when it was given three passes through a ‘Minisonic’ homogenizer (Sonic Eng. Corp., Stamford, Conn.). From this treatment, a stable isotropic suspension was obtained and the pH had risen to 3.5. The rise in pH is probably due to release, from within the crystallites, of some unacetylated amino-groups which complexed with a proton to give at the crystallite surfaces. The presence of free NH2 groups in chitin, which is supposed to be a polymer of N-acetyl-d-glucosamine is not unexpected since purification procedures involve alkaline conditions which can saponify acetyl groups. Electron micrographs of the stable suspension show the presence of rod-like particles of similar dimensions to the cellulose crystallites2.
TL;DR: The precise definition of the amyloid protein has, however, been hampered by its insolubility in organic solvents.
Abstract: AMYLOIDOSIS in man and animals may be associated with other disease entities or may occur spontaneously. The relationship, if any, of the different forms of amyloid has proved difficult to ascertain, and the chemical nature of amyloid has not been established. Previous studies have indicated that it is predominantly protein in nature1,2 and have suggested that the protein is not primarily collagen3 or γ-globulin4. No chemical differences have been noted in amyloid of different sources. The precise definition of the amyloid protein has, however, been hampered by its insolubility in organic solvents.
TL;DR: Cells of hamster ovarian and lung tissues propagated in culture medium did not display heritable damage frora x irradiation, and repaired their accumulated damage before their iirst division after irradiation.
Abstract: Cells of hamster ovarian and lung tissues propagated in culture medium did not display heritable damage frora x irradiation. They repaired their accumulated damage before their iirst division after irradiation. Contexts in which the findings are of interest are discussed. (C.H.)
TL;DR: Heterogeneity in Deoxyribonucleic Acids: I. Dependence on Composition of the Configurational Stability of Deoxy ribonucleics Acids is dependent on composition of the configuration of the configureational stability.
Abstract: Heterogeneity in Deoxyribonucleic Acids: I. Dependence on Composition of the Configurational Stability of Deoxyribonucleic Acids
TL;DR: Electron microscopy shows that certain dendrites of the cerebral cortex and elsewhere appear to have numerous spinous projections that are in fact sites of synaptic contact.
Abstract: WHEN stained by the Golgi or methylene-blue method for light microscopy, certain dendrites of the cerebral cortex and elsewhere appear to have numerous spinous projections1. The nature of these spines has long been disputed. For example, it has been suggested that they are simply ‘nutritive’ expansions, or pre-synaptic end-feet, or post-synaptic processes of the dendrite—the pre-synaptic component remaining unstained1–3. Electron microscopy shows that the spines are in fact sites of synaptic contact.
TL;DR: This report deals with the course of three transplantable tumours, S-180, carcinoma 755 (Ca 755), and Ehrlich ascites, in mice infected with Bacillus Calmette-Guérin.
Abstract: DURING the growth of certain transplanted tumours considerable hyperactivity of the reticulo-endothelial system is observed.1 Similar alterations are also found in the first stage of experimental infections2, suggesting that the host response to foreign tissue and some infectious agents is closely related. Agents such as endotoxins, zymosan, products of the tubercle bacillus, and Bacillus Calmette-Guerin infection which enhance the activity of the reticulo-endothelial system3 and the capacity for antibody production4 also increase natural resistance to infection5. In light of these observations, we have attempted to alter the growth and lethality of various experimental tumours by agents known to possess the common property of stimulating the phagocytic capacity of the reticulo-endothelial system. One such agent, zymosan, has been demonstrated to increase significantly the regression rate of the mouse tumour, sarcoma 180 (S-180), under certain conditions6. The present report deals with the course of three transplantable tumours, S-180, carcinoma 755 (Ca 755), and Ehrlich ascites, in mice infected with Bacillus Calmette-Guerin.
TL;DR: It was decided to examine the carbohydrates and their derivatives in normal and cataractous lenses to see if changes occurred in ‘sugar’Cataract, and if so whether there was any similarity in this respect between the three forms of cataracts.
Abstract: CATARACT (opacity) of the lens inevitably develops in young rats fed xylose or galactose1, or in young diabetic rats if the blood glucose is maintained at a level above 2.5 mgm./ml. blood2. These three forms of cataract which resemble each other closely in clinical and histological appearance, are known as ‘sugar’ cataracts because in all cases there is a raised level of monosaccharides in the blood. The early metabolic changes within the lens, which lead to gradual loss of transparency, are unknown. It was decided to examine the carbohydrates and their derivatives in normal and cataractous lenses to see if changes occurred in ‘sugar’ cataract, and if so whether there was any similarity in this respect between the three forms of cataract.
TL;DR: The purpose of this communication is to describe the apparent induction of immunological tolerance in adult rabbits by the use of 6-mercaptopurine.
Abstract: PREVIOUS work in this laboratory demonstrated that administration of a purine analogue, 6-mercaptopurine, suppressed the antibody response to a soluble antigen (human serum albumin) in rabbits1. It was shown that the antimetabolite could block completely the primary immune response to the purified protein antigen; its effect on the secondary response, however, was minimal2. It is the purpose of this communication to describe the apparent induction of immunological tolerance in adult rabbits by the use of 6-mercaptopurine.
TL;DR: A coupling reaction was worked out utilizing the conjugation of aldoses and ketoses with meta-aminophenol in acetic acid to avoid the non-specific reduction methods for glucose determinations.
Abstract: IN the clinical field it is of importance to have a rapid and exact method for glucose determinations. In order to avoid the non-specific reduction methods, a coupling reaction was worked out utilizing the conjugation of aldoses and ketoses with meta-aminophenol in acetic acid. After some preliminary experiments1, a routine method was described2. The method has been used for some time in this laboratory and has proved satisfactory; but, because of the necessarily long boiling time of 30 min., and the fact that the whole range of urine sugar concentration cannot be read without dilution of the urine, it was considered an advantage to have a reagent giving a more rapid reaction and a wider range. Many aromatic amines have been tested; of these, one of the most suitable was ortho-toluidine, for which the optimal boiling time is 8 min. (Fig. 1). It gives a blue-green colour with maximum absorption at 6250 A. and is fairly specific for aldosugars (Fig. 2). Blood treated with glucose oxidase gave readings corresponding to 0–4 mgm. glucose per 100 ml. blood. With this reagent glucose quantities of 10–400 µgm. can be read directly in a Beckman B photometer.
TL;DR: In the course of experiments on the amino-acid composition of rumen Protozoa, an unknown ninhydrin-positive substance was found by paper chromatography to be present in acid hydrolysates of the ether-ethanol soluble fraction of ProtozoA.
Abstract: IN the course of experiments on the amino-acid composition of rumen Protozoa, an unknown ninhydrin-positive substance was found by paper chromatography to be present in acid hydrolysates of the ether-ethanol soluble fraction of Protozoa. The substance was isolated in crystalline form and identified as 2-amino-ethane phosphonic acid, H2N·CH2·CH2·PO(OH)2, (synthesized by Finkelstein1, Kosolapoff2, Hackspill3 and Chavane4).
TL;DR: In this article, the radio-telemetry system for Pioneer III observations of the Earth's radiation belt is described and the vehicle and its trajectory information is given, and logs of flight and telemetry data and analysis of the data are presented under the following topics: intensity- structure of the region of trapped radiation; effective radial extent of the geomagnetic field; interplanetary value of cosmic-ray intensity; fluctuations in counting rate beyond 10 earth radii; and biological exposure levels (JHM)
Abstract: Radiation detectors and the radio-telemetry system for Pioneer III observations of the Earth's radiation belt are described Information is given on the vehicle and its trajectory, and logs of flight and telemetry Observation data and analysis of the data are presented under the following topics: intensity- structure of the region of trapped radiation; effective radial extent of the geomagnetic field; interplanetary value of cosmic-ray intensity; fluctuations in counting rate beyond 10 earth radii; and biological exposure levels (JHM)
TL;DR: The permanganate method used by Evans and Guild has been shown by Svendsen2 greatly to under-estimate the population of L. terrestris and my tests at Wisbech confirmed this.
Abstract: WHILE investigating the removal of leaves by earthworms from the soil surface of some apple orchards at Wisbech (Cambs.) an estimate of the population of Lumbricus terrestris was needed because it seemed to be the only species present that pulled apple leaves into its burrows. L. terrestris burrows deeply in the light, well-drained soil of the Wisbech area, and a population estimate made by removing and hand-sorting soil samples was impracticable because of the depth of the burrows into which the worms retreat when soil samples are removed. The permanganate method used by Evans and Guild1 has been shown by Svendsen2 greatly to under-estimate the population and my tests at Wisbech confirmed this.
TL;DR: This work has shown that it is necessary to confer sufficient electron density upon an antibody molecule, without inactivating it, to render it visible in the electron microscope.
Abstract: THE fluorescent antibody conjugate technique recently developed by Coons1 has already proved of great value in the study of biological problems. In this technique, a fluorescent substance is covalently linked to an antibody, and the antibody conjugate is allowed to react with cells or tissue containing its homologous antigen. The antigen is then detected and localized by observing the fluorescence in an optical microscope. For many reasons, it is desirable to extend this method to the sub-cellular level with the resolution attainable in the electron microscope. In order to achieve this purpose, however, it is necessary to confer sufficient electron density upon an antibody molecule, without inactivating it, to render it visible in the electron microscope.
TL;DR: A procedure to fertilize rabbit ova in vitro and the probability of normal development in vivo of such in vitro fertilized Rabbit ova is reported.
Abstract: IN reviews of the evidence for mammalian fertilization in vitro, Austin and Bishop1 stated that “it seems best for the present to regard the case as sub judice”. Chang2 concluded that “up till now we still do not have a repeatable procedure to fertilize mammalian eggs in vitro”. Since the recognition of ‘capacitation’ of spermatozoa in the female tract by Chang3 and Austin4, Thibault and his associates5–7 have reported cytological evidences of fertilization of rabbit ova in vitro by capacitated sperms. It was thought that unless living young are obtained by transplanting such fertilized ova into recipient rabbits, fertilization in vitro, as determined by cytological evidences, may not be sufficiently proved because such ova may be abnormally and/or incompletely fertilized, may die during the process, or may not be fertilized at all. This note reports a procedure to fertilize rabbit ova in vitro and the probability of normal development in vivo of such in vitro fertilized rabbit ova.