Showing papers in "Nature in 1969"
TL;DR: The platinum compounds inhibit sarcoma 180 and leukaemia L1210 in mice and reversibly inhibit cell division in Gram-negative rods1–4.
Abstract: CERTAIN platinum compounds completely but reversibly iiihibit cell division in Gram-negative rods1–4. These compounds have been tested for antitumour activity and we report some of the preliminary results. The platinum compounds inhibit sarcoma 180 and leukaemia L1210 in mice.
3,574 citations
TL;DR: Powerful emissions from the centres of nearby galaxies may represent dead quasars as mentioned in this paper, which may represent the end of the universe as we know it. But this is not always the case.
Abstract: Powerful emissions from the centres of nearby galaxies may represent dead quasars.
1,268 citations
TL;DR: Polarization of the system due to the buried negative charge of the aspartic acid residue would make the serine oxygen strongly nucleophilic and would explain its reactivity towards amides and esters.
Abstract: The catalytic site of chymotrypsin contains an interior aspartic acid hydrogen-bonded to a histidine which in its turn is hydrogen-bonded to a serine. Polarization of the system due to the buried negative charge of the aspartic acid residue would make the serine oxygen strongly nucleophilic and would explain its reactivity towards amides and esters.
967 citations
TL;DR: A protein component usually associated with RNA polymerase can be separated from the enzyme by chromatography on phosphocellulose, and the polymerase is unable to transcribe T4 DNA unless this factor is added back.
Abstract: A protein component usually associated with RNA polymerase can be separated from the enzyme by chromatography on phosphocellulose. The polymerase is unable to transcribe T4 DNA unless this factor is added back.
917 citations
TL;DR: Genetic studies of alkylation mutants in bacteria and bacteriophages have shown that many point mutational events involve guanine to adenine transitions, and the most abundant reaction product found in acid hydrolysates of treated DNA is 7-alkyl Guanine.
Abstract: BIOLOGICAL alkylating agents—“mustards”, ethylenimines, epoxides and alkyl alkanesulphonates—have been believed to induce mutations by causing atypical base pairing during DNA replication at sites bearing a guanine residue which has suffered alkylation at the 7(N) position1,2. The most abundant reaction product found in acid hydrolysates of treated DNA is 7-alkyl guanine3,4, although alkylated adenines and cytosine, notably 3-alkyl adenine, are recovered as minor products. Furthermore, genetic studies of alkylation mutants in bacteria and bacteriophages have shown that many point mutational events involve guanine to adenine transitions5,6.
913 citations
TL;DR: Three distinct RNA polymerase activities have been isolated from developing sea urchin embryos, and in rat liver nuclei there are two RNA polymerases activities.
Abstract: Three distinct RNA polymerase activities have been isolated from developing sea urchin embryos. In rat liver nuclei there are two RNA polymerase activities. One polymerase (I) is probably localized in the nucleolus and one (II) in the nucleoplasm.
895 citations
TL;DR: It is reported that both mono and dimethylmercury can be produced in bottom sediments and in rotten fish, and relate the findings to the hazards of mercury pollution.
Abstract: FRESHWATER fish, especially pike (Esox lucius), from Sweden sometimes contain abnormally large amounts of mercury1. It was initially concluded to be either inorganic mercury or phenyl mercury, which are known to be released as industrial wastes, but later it was shown that the mercury was present almost entirely as methyl mercury (CH3Hg+)2. A possible explanation is that living organisms have the capacity to methylate mercury compounds present in pollution. We now report that both mono and dimethylmercury (CH3Hg+ and CH3HgCH3) can be produced in bottom sediments and in rotten fish, and relate the findings to the hazards of mercury pollution.
865 citations
TL;DR: Mutual interference between searching insect parasites provides theoretical support for current biological control practices and helps clarify the role of ‘spatially aggregating’ immune defences.
Abstract: Mutual interference between searching insect parasites provides theoretical support for current biological control practices.
847 citations
TL;DR: Among the active substances released during anaphylaxis in guinea-pig lung is a hitherto unidentified substance which has a contracting effect on rabbit aorta.
Abstract: Among the active substances released during anaphylaxis in guinea-pig lung is a hitherto unidentified substance which has a contracting effect on rabbit aorta. The release of this compound is antagonized by anti-inflammatory agents.
823 citations
TL;DR: The influences on ion energy of membrane thickness, ion-pair formation, “pores” and “carriers” have been estimated and it is shown that only “ pores" and "carriers" lower the energy barrier significantly.
Abstract: The influences on ion energy of membrane thickness, ion-pair formation, “pores” and “carriers” have been estimated. Only “pores” and “carriers” lower the energy barrier significantly.
778 citations
TL;DR: It is suggested that allogeneic liver can induce immunological tolerance in immunologically mature pigs and help protect donor specific tissue from rejection.
Abstract: Liver allografting experiments with pigs show that animals given no immunosuppression will survive for prolonged periods with orthotopic liver transplants. Similar animals can reject skin, kidneys and hearts rapidly. Orthotopic and accessory heterotopic liver allografts protect preferentially from rejection grafts of donor specific skin, kidney and possibly heart. Injected soluble liver antigen may also protect donor specific tissue from rejection. It is suggested that allogeneic liver can induce immunological tolerance in immunologically mature pigs.
TL;DR: A new protein has been isolated from E. coli which causes specific termination and release of RNA during synthesis in vitro and has been given the name ρ-factor.
Abstract: A new protein has been isolated from E. coli which causes specific termination and release of RNA during synthesis in vitro. It has been given the name ρ-factor.
[...]
TL;DR: Animal Bones in ArchaeologyBook of Notes and Drawings for Beginners.
Abstract: Animal Bones in Archaeology Book of Notes and Drawings for Beginners. By Michael L. Ryder. (Mammal Society Handbooks.) Pp. xxiv + 65. (Blackwell (Scientific): Oxford and Edinburgh. Published for the Mammal Society, 1969.) 17s.
TL;DR: By testing indiscriminately several thousand colonies of mutagenized E. coli, a mutant has been isolated that on extraction proves to have less than I per cent of the normal level of DNA polymerase.
Abstract: By testing indiscriminately several thousand colonies of mutagenized E. coli, a mutant has been isolated that on extraction proves to have less than I per cent of the normal level of DNA polymerase. The mutant multiplies normally but has acquired an increased sensitivity to ultraviolet light.
TL;DR: A vision substitution system which is being developed as a practical aid for the blind and as a means of studying the processing of afferent information in the central nervous system is described.
Abstract: WE describe here a vision substitution system which is being developed as a practical aid for the blind and as a means of studying the processing of afferent information in the central nervous system. The theoretical neurophysiological basis1 and the physical concept of the instrumentation2 have been discussed previously, and results obtained with preliminary models have been briefly reported3. A detailed description of the apparatus will appear elsewhere (manuscript in preparation).
TL;DR: Autoradiography has revealed in a stringent strain of E. coli two compounds that seem to be involved in the inhibition of the synthesis of RNA.
Abstract: Autoradiography has revealed in a stringent strain of E. coli two compounds that seem to be involved in the inhibition of the synthesis of RNA.
TL;DR: This work has found what seems to be a new class of dynamically stable systems, which suggests that even haphazardly constructed control nets of high molecular specificity undergo homeostasis and differentiation.
Abstract: THE genome is a complex net of interacting components commonly thought to control homeostasis and differentiation through precisely constructed control circuits among the genes1–6. But I have found what seems to be a new class of dynamically stable systems, which suggests that even haphazardly constructed control nets of high molecular specificity undergo homeostasis and differentiation.
TL;DR: Radioactive RNA introduced into “target” cells can be induced to form hybrids with nuclear DNA and the location of these hybrids can be detected by autoradiography.
Abstract: Radioactive RNA introduced into “target” cells can be induced to form hybrids with nuclear DNA. The location of these hybrids can be detected by autoradiography.
TL;DR: The sparing of fatty streaking in localized areas is reported, at which they suggest low wall shear rate (the product of velocity gradient and fluid viscosity) is experienced and shown that acute elevation of shear rates on the aortic wall causes endothelial damage and increased permeability to lipids.
Abstract: THE patchy distribution of fatty streaking and early atheroma has been associated with arterial blood mechanics. Mustard et al.1 have noted occurrence of atheroma at sites which are thought to experience particle (platelet) deposition as the result of local rapid flow fluctuations (turbulence) or eddies. Others have proposed platelet deposition in regions of flow separation2. Texon3 invoked damage due to Bernoulli-type suction forces in areas of locally increased blood velocity; but this is considered implausible because the forces are negligible in physiological conditions in comparison with normal variations of mean blood pressure. Mitchell and Schwartz4 reported the sparing of fatty streaking in localized areas, at which they suggest low wall shear rate (the product of velocity gradient and fluid viscosity) is experienced. Fry5,6 has shown that acute elevation of shear rate on the aortic wall causes endothelial damage and increased permeability to lipids. These theories assign to fluid mechanics a causative role in atherogenesis.
TL;DR: POLYSACCHARIDE preparations from bamboo leaves, bagasse2,3 and wheat straw inhibit the growth of sarcoma 180 implanted subcutaneously in mice and it was proposed that this activity was host mediated, not cytocidal.
Abstract: POLYSACCHARIDE preparations from bamboo leaves1, bagasse2,3 and wheat straw4 inhibit the growth of sarcoma 180 implanted subcutaneously in mice. It was proposed that this activity was host mediated, not cytocidal.
TL;DR: The direct effects of glucose on individual cells of the VMH and LH are studied by means of electro-osmotic applications of glucose from micropipettes—the method used by Krnjević and Whittaker in other regions in the brain.
Abstract: THE lateral hypothalamic region (LH) is generally referred to as the feeding centre of the brain in the regulation of food intake, and many authors consider the ventromedial hypothalamic nucleus (VMH) to be the satiety centre1. Various hypotheses have been put forward to explain how the cells of these centres are activated, and one of these is the glucostat theory1. The existence of hypothalamic chemoreceptors, such as those sensitive to the concentration of blood glucose, can be inferred from studies of single unit discharges induced by intravenous or intracarotid administration of various solutions2–4 and from work on selective gold thioglucose lesions5. It has, however, been impossible to determine which centre is activated or inhibited first or whether both centres are modulated directly by a change in the concentration of blood glucose, because of the reciprocal relations which exist between the activities of the VMH and the LH2,6. We report here the direct effects of glucose on individual cells of the VMH and LH, which we studied by means of electro-osmotic applications of glucose from micropipettes—the method used by Krnjevic and Whittaker7 in other regions in the brain.
TL;DR: The simple geometric ideas of plate theory are extended to include some forms of plate evolution as discussed by the authors The most important of these occurs where three plates meet such triple junctions are divided into two groups, stable and unstable, according to whether or not they can retain their geometry as the plates move.
Abstract: The simple geometric ideas of plate theory are extended to include some forms of plate evolution The most important of these occurs where three plates meet Such triple junctions are divided into two groups, stable and unstable, according to whether or not they can retain their geometry as the plates move These ideas suggest an explanation for some of the major changes which have occurred in the North Pacific during the Tertiary
TL;DR: The initiator regions of the three cistrons of R17 bacteriophage RNA have been isolated and sequenced and contain a UGA triplet as well as the expected AUG and two contain the sequence GGUUUGA.
Abstract: The initiator regions of the three cistrons of R17 bacteriophage RNA have been isolated and sequenced. All three regions contain a UGA triplet as well as the expected AUG and two contain the sequence GGUUUGA. The initiator regions thus represent untranslated sequences between termination and initiation codons.
TL;DR: The mutant eye has functional abnormality at the retinal level—yet, as in the nonphototactic mutants, histological sections of retinal structure of the mutant eye are indistinguishable from sections of wild-type eye under the light microscope.
Abstract: THE use of behavioural mutants of Drosophila to elucidate functions of the nervous system has produced several nonphototactic mutants snowing abnormality in the recorded waveform of the electroretinogram (ERG)1,2. We are working with a mutant strain of D. melanogaster which, though behaving phototactically positive in a T-maze under low ambient light, is visually impaired and behaves as though blind in a simple optomotor apparatus where normal, wild-type flies will orientate to visual cues3,4. The mutant appeared in a highly inbred line and is indistinguishable from the wild-type in external appearance. Detailed mapping is in progress but, at this stage, we know that the single Mendelian factor responsible is fully recessive and located on the third chromosome. The mutant eye has functional abnormality at the retinal level—yet, as in the nonphototactic mutants, histological sections of retinal structure of the mutant eye are indistinguishable from sections of wild-type eye under the light microscope.
TL;DR: Malignancy can be suppressed when malignant cells are fused with certain non-malignant ones and the hybrid cells derived from such fusions give rise to segregants in which a loss of chromosomes is associated with reversion to malignancy.
Abstract: Malignancy can be suppressed when malignant cells are fused with certain non-malignant ones. The hybrid cells derived from such fusions give rise to segregants in which a loss of chromosomes is associated with reversion to malignancy. The expression of histo-compatibility antigens can also be suppressed when cells bearing these antigens are fused with others that express them poorly.
TL;DR: Patients whose neocortical commissures have been surgically divided for the control of epilepsy have revealed an organizational differentiation of the hemispheres for perceptual and cognitive functions.
Abstract: WORK carried out during the past few years with patients whose neocortical commissures have been surgically divided for the control of epilepsy has revealed an organizational differentiation of the hemispheres for perceptual and cognitive functions1,2.
TL;DR: Analyses of pesticide residues in a wide range of marine organisms from the coastal waters of Sweden show that there is a marked contamination in the Baltic.
Abstract: Analyses of pesticide residues in a wide range of marine organisms from the coastal waters of Sweden show that there is a marked contamination in the Baltic. There are signs of an increase in polychlorinated biphenyls (PCB) from north to south in this area. Exceptionally large amounts of residues were found in white tailed eagles from the archipelago of Stockholm.
TL;DR: Four principal features of cellular immunity in the guinea-pig are mediated by a group of soluble factors generated by antigen-activated lymphocytes, which are different from classical antibodies.
Abstract: Four principal features of cellular immunity in the guinea-pig are mediated by a group of soluble factors generated by antigen-activated lymphocytes These “lymphokines” are different from classical antibodies
TL;DR: In this paper, a single polypeptide chain is folded into three parts, with the active site at their conjunction, and the side chain of His 64 is in a position consistent with the formation of a hydrogen bond between it and the OH group of Ser 221.
Abstract: The single polypeptide chain is folded into three parts, with the active site at their conjunction. In the active enzyme, the side chain of His 64 is in a position consistent with the formation of a hydrogen bond between it and the OH group of Ser 221.
TL;DR: The appearance of circular Moiré fringes when a random dot pattern is superimposed on itself provides new evidence that the human visual process may include the computation of local autocorrelations by excitation of line detectors.
Abstract: The appearance of circular Moire fringes when a random dot pattern is superimposed on itself provides new evidence that the human visual process may include the computation of local autocorrelations by excitation of line detectors.