abstract：:It is a controversial issue whether 'real' movement, seen from the successive stimulation of retinal receptors by a moving image, and 'apparent' (phi) movement, which is produced by stimuli separated in space and time, are transmitted by the same or different neural channels. With this question in mind, we have devise...

journal_title：Nature

authors： Gregory RL,Harris JP

更新日期：1984-02-23 00:00:00

abstract：:The detection of horizontal disparities between the right and left retinal images is accepted as an important component in the visual perception of depth. It has occasionally been pointed out that a disparity will also occur in the vertical when a target is nearer to one eye than the other and could be used as a secon...

journal_title：Nature

authors： Westheimer G

更新日期：1984-02-16 00:00:00

abstract：:Among the pathological effects in man following infection with Mycoplasma pneumoniae is a transient autoimmune disorder characterized by the presence of high-titre erythrocyte autoantibodies (cold agglutinins). These autoantibodies are usually directed against the carbohydrate antigen termed I (ref. 3) which consists ...

journal_title：Nature

authors： Loomes LM,Uemura K,Childs RA,Paulson JC,Rogers GN,Scudder PR,Michalski JC,Hounsell EF,Taylor-Robinson D,Feizi T

更新日期：1984-02-09 00:00:00

abstract：:One of the most exciting events in recent years in molecular biology was the discovery of the left-handed Z form of the DNA double helix. Originally found in linear self-complementary d(GC)x . d(GC)x polymers and oligomers in non-physiological conditions (a rather high salt concentration), it was recently shown to be ...

journal_title：Nature

authors： Frank-Kamenetskii MD,Vologodskii AV

更新日期：1984-02-02 00:00:00

abstract：:A mouse major histocompatibility antigen (H-2) gene, encoding a novel H-2Ld molecule lacking its intracytoplasmic domain, has been constructed and introduced into mouse L-cells. The novel H-2 molecule is found on the surface of the transfected cells at the same level as L-cells transfected with the native H-2Ld gene. ...

journal_title：Nature

authors： Murre C,Reiss CS,Bernabeu C,Chen LB,Burakoff SJ,Seidman JG

更新日期：1984-02-02 00:00:00

abstract：:The shape of the human erythrocyte depends on intracellular ATP content and echinocytic erythrocyte ghosts obtained in the presence of Mg-ATP acquire a diskocytic shape after incubation at 37 degrees C; however, agreement is lacking about the molecular basis of the shape changes. The suggestion that phosphorylation of...

journal_title：Nature

authors： Jinbu Y,Sato S,Nakao M

更新日期：1984-01-26 00:00:00

abstract：:Astrocyte proliferation and perivascular lymphocyte infiltration are conspicuous among the cellular changes in the active brain lesions of multiple sclerosis patients. Recent observations have indicated that most of the perivascular lymphocytes are T cells which may be actively involved in the generation of the brain ...

journal_title：Nature

authors： Fontana A,Fierz W,Wekerle H

更新日期：1984-01-19 00:00:00

abstract：:Several distinct cell lineages are established during mouse embryogenesis. The trophectoderm and primitive endoderm give rise to extraembryonic structures alone, while the primitive ectoderm becomes the fetus proper. Recent studies suggest that the levels of DNA modification are lower in inactive X chromosomes from ex...

journal_title：Nature

authors： Chapman V,Forrester L,Sanford J,Hastie N,Rossant J

更新日期：1984-01-19 00:00:00

abstract：:Transposable elements from prokaryotic and eukaryotic organisms are discrete DNA segments bounded by inverted or directly repeated sequences that insert into non-homologous DNA in a reaction that is independent of the general recombination functions of the host. The mechanisms proposed generally involve a staggered do...

journal_title：Nature

authors： Murphy E,Löfdahl S

更新日期：1984-01-19 00:00:00

abstract：:The giant polytene chromosomes of Drosophila melanogaster have long been of interest to the geneticist because of the visible map of the genome provided by their characteristic banding patterns. An issue in the understanding of the molecular basis of chromosome banding has been whether the chromosomal DNA is replicate...

journal_title：Nature

authors： Spierer A,Spierer P

更新日期：1984-01-12 00:00:00

abstract：:The site of action of the antispastic drug baclofen has long been considered to reside in the spinal cord although supraspinal effects have also been reported. This beta-chlorophenyl derivative of the neurotransmitter gamma-aminobutyric acid (GABA) depresses both monosynaptic and polysynaptic transmission in the cord ...

journal_title：Nature

authors： Price GW,Wilkin GP,Turnbull MJ,Bowery NG

更新日期：1984-01-05 00:00:00

abstract：:Recent studies have shown that developing nerve fibres grow directly to their targets and are guided by specific cues, but the nature of these cues and the mechanism of guidance remain unknown. The growth of sympathetic axons towards an artificial source of nerve growth factor (NGF) in vivo and of sensory neurites up ...

journal_title：Nature

authors： Lumsden AG,Davies AM

更新日期：1983-12-22 00:00:00

abstract：:Recent studies have shown that short chemically synthesized peptides very often induce antibodies which react with the cognate sequence in the intact folded protein. Since such antibodies react with known regions of proteins, they are of predetermined specificity and offer a precision not previously possible with immu...

journal_title：Nature

authors： Alexander H,Johnson DA,Rosen J,Jerabek L,Green N,Weissman IL,Lerner RA

更新日期：1983-12-15 00:00:00

abstract：:DNA sequences containing the 5'-flanking regions of the insulin and chymotrypsin genes were linked to the coding sequence of the chloramphenicol acetyltransferase (CAT) gene. The insulin gene recombinant elicits preferential expression of CAT activity when introduced into cells producing insulin; similarly, the chymot...

journal_title：Nature

authors： Walker MD,Edlund T,Boulet AM,Rutter WJ

更新日期：1983-12-08 00:00:00

abstract：:Haemoglobin is the prototype of an allosteric protein in which cooperative behaviour depends on interaction between unlike subunits. Here we present haematological and biochemical evidence that electrostatic interactions are an important determinant of haemoglobin assembly. Individuals heterozygous for positively char...

journal_title：Nature

authors： Bunn HF,McDonald MJ

更新日期：1983-12-01 00:00:00

abstract：:Epstein-Barr virus (EBV), a member of the herpes group of viruses and the aetiological agent of infectious mononucleosis, is usually thought of as a lymphotrophic virus with the ability to transform B lymphocytes. So the association of EBV with nasopharyngeal carcinoma is puzzling, especially given the lack of success...

journal_title：Nature

authors： Sixbey JW,Vesterinen EH,Nedrud JG,Raab-Traub N,Walton LA,Pagano JS

更新日期：1983-12-01 00:00:00

abstract：:The alpha-helix defined in 1951 by Pauling et al. on the basis of model building and X-ray fibre diffraction data has 3.65 residues per turn (n) achieved with planar peptides, torsion angles of phi = -48 degrees and psi = -57 degrees and hydrogen bonds which are close to linear. Although X-ray analyses of proteins hav...

journal_title：Nature

authors： Blundell T,Barlow D,Borkakoti N,Thornton J

更新日期：1983-11-17 00:00:00

abstract：:Serious, and occasionally fatal, anaphylactic-like (anaphylactoid) reactions may occur when a patient is exposed to a drug for the first time. Apart from the penicillins, nothing is known of the nature of antigenic or sensitizing drug determinants and, as yet, there is no evidence for the involvement of IgE antibodies...

journal_title：Nature

authors： Baldo BA,Fisher MM

更新日期：1983-11-17 00:00:00

abstract：:Copper, zinc superoxide dismutase (SOD) catalyses the very rapid two-step dismutation of the toxic superoxide radical (O-2) to molecular oxygen and hydrogen peroxide through the alternate reduction and oxidation of the active-site copper. We report here that after refitting and further refinement of the previous 2 A s...

journal_title：Nature

authors： Tainer JA,Getzoff ED,Richardson JS,Richardson DC

更新日期：1983-11-17 00:00:00

abstract：:During attempts to select nonsecretory variants from 0.467.3, and Epstein-Barr virus-transformed human lymphoblastoid cell line that secretes small amounts of IgM lambda, we exposed the cells to UV light. Cells that survived the irradiation were subcultured and their supernatants were screened for immunoglobulin produ...

journal_title：Nature

authors： Rosén A,Klein G

更新日期：1983-11-10 00:00:00

abstract：:Secretory antibodies of the IgA class (sIgA) are thought to have an important role in the defence against bacteria at mucosal surfaces--the level at which the infectious agents first come into contact with the host. However, the mechanism by which sIgA exert their antibacterial activity is still a matter of debate. Af...

journal_title：Nature

authors： Tagliabue A,Nencioni L,Villa L,Keren DF,Lowell GH,Boraschi D

更新日期：1983-11-10 00:00:00

abstract：:The human gene for the hepatic enzyme phenylalanine hydroxylase has been cloned and used to analyse the phenylalanine hydroxylase locus in the human genome. The detection of polymorphisms in this locus by several restriction enzymes has allowed feasibility studies of prenatal diagnosis of classical phenylketonuria and...

journal_title：Nature

authors： Woo SL,Lidsky AS,Güttler F,Chandra T,Robson KJ

更新日期：1983-11-10 00:00:00

abstract：:The Environmental Protection Agency is preparing to regulate the biotechnology industry, claiming authority under the provisions of the Federal Toxic Substances Control Act (TOSCA) and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). In the agency's view, the products of recombinant DNA techniques can...

journal_title：Nature

authors： Earl C

更新日期：1983-11-03 00:00:00

abstract：:Regulation of the rapid compensatory growth seen in the remaining adrenal gland of rats following unilateral adrenalectomy is poorly understood. The role of adrenocorticotropic hormone (ACTH) is obscure as immunoneutralization of circulating ACTH does not affect the observed compensatory growth or hyperplasia. This fi...

journal_title：Nature

authors： Lowry PJ,Silas L,McLean C,Linton EA,Estivariz FE

更新日期：1983-11-03 00:00:00

abstract：:In infected cells, the RNA genomes of RNA tumour viruses are copied into DNA by a virus-encoded reverse transcriptase enzyme. This transfer of information from RNA into DNA was thought to be a unique feature of RNA tumour viruses, but recent results suggest it may be a more general strategy. Hepatitis B virus (HBV) ha...

journal_title：Nature

authors： Toh H,Hayashida H,Miyata T

更新日期：1983-10-27 00:00:00

abstract：:A brief account is provided of a meeting between federal officials and representatives of the Industrial Biotechnology Association (IBA), a consortium of companies concerned about the regulatory outlook for their industry. Current regulatory interest is focused on the Environmental Protection Agency, which has declar...

journal_title：Nature

authors： David P

更新日期：1983-10-27 00:00:00

abstract：:The lysis of murine sarcoma virus-murine leukaemia virus (MSV-MuLV)-induced tumour cells by cytotoxic T lymphocytes (CTL) appears to require that an antigen specified by MSV-MuLV, or induced by the infection, be presented in association with class I major histocompatibility complex antigens. The viral proteins of the ...

journal_title：Nature

authors： Flyer DC,Burakoff SJ,Faller DV

更新日期：1983-10-27 00:00:00

abstract：:Surgical sectioning of the corpus callosum in epileptic patients has provided a unique opportunity to study separately the competence and processing capacities of the two cerebral hemispheres, each of which is able to perceive, think, memorize and learn independently and essentially outside the realm of awareness of t...

journal_title：Nature

authors： Sergent J

更新日期：1983-10-27 00:00:00

abstract：:All synaptically-based neuropsychological theories of learning postulate that there are changes resulting from neural activity which are long-lasting and confined to specific sets of synapses. In the past decade a form of synaptic strengthening known as long-term potentiation (LTP) has been found which results from hi...

journal_title：Nature

authors： Abraham WC,Goddard GV

更新日期：1983-10-20 00:00:00

abstract：:A single U leads to G transversion in the 3' consensus sequence AAUAAA of the adenovirus early region 1A gene was constructed and the effect of this mutation on processing of the 3' end of the nuclear early region 1A RNAs was analysed. The results demonstrate that the intact AAUAAA is not required for RNA polyadenylat...

journal_title：Nature

authors： Montell C,Fisher EF,Caruthers MH,Berk AJ

更新日期：1983-10-13 00:00:00

abstract：:Replication of multipotential stem cells in long-term murine bone marrow cell culture is known to depend on the development of an adherent stromal cell layer. In these conditions, restricted haematopoietic progenitor cells have also been generated for up to several months1-3. However, maturation is observed only in th...

journal_title：Nature

authors： Wendling F,Shreeve MM,McLeod DL,Axelrad AA

更新日期：1983-10-13 00:00:00

abstract：:The University of California at Berkeley has announced the postponement of a planned experiment involving the field testing of bacteria genetically engineered to reduce frost damage to crops. The action came after Jeremy Rifkin, who had earlier filed suit against the National Institutes of Health after its Recombinan...

journal_title：Nature

authors： Budiansky S

更新日期：1983-10-13 00:00:00

abstract：:The sensation of pain is carried to the central nervous system by small-diameter fibres which terminate in the superficial layers of the spinal grey matter, particularly the substantia gelatinosa. Opiate drugs administered into the substantia gelatinosa inhibit the excitation of deeper dorsal horn neurones by noxious ...

journal_title：Nature

authors： Yoshimura M,North RA

更新日期：1983-10-06 00:00:00

abstract：:There is considerable interest in the existence and significance of alternative conformations of DNA to the right-handed B-form described originally by Watson and Crick. The indirect immunofluorescence observations of Nordheim et al., Arndt-Jovin et al. and Lemeunier et al. that antibodies against left-handed Z-DNA bi...

journal_title：Nature

authors： Hill RJ,Stollar BD

更新日期：1983-09-22 00:00:00

abstract：:Three environmental groups have filed suit against the National Institutes of Health in an attempt to block an experiment approved in April by the NIH Recombinant DNA Advisory Committee. The experiment, designed by researchers at the University of California, Berkeley, to enhance the frost resistance of crops, would ...

journal_title：Nature

authors： David P

更新日期：1983-09-22 00:00:00

abstract：:When a portrait is coarsely quantized into blocks, the block structure hides the face, although lower spatial frequencies of the original image sufficient by themselves for recognition are preserved. Recognition can be recovered by blurring the image, or otherwise attenuating the spurious higher spatial frequency comp...

journal_title：Nature

authors： Morrone MC,Burr DC,Ross J

更新日期：1983-09-15 00:00:00

abstract：:A statute banning nuclear weapons research in Cambridge, Massachusetts, is scheduled for a referendum vote in November 1983. If passed, the act would require the city to fine or imprison violators after the ban takes effect in October 1985, and could have an impact on work done at Harvard University and the Massachus...

journal_title：Nature

authors： David P

更新日期：1983-09-15 00:00:00

abstract：:We have postulated that an excitatory postsynaptic potential (e.p.s.p.) may open voltage-sensitive K+ ('M') channels, in an appropriate depolarizing range, and that this could alter the e.p.s.p. waveform. Consequently, the fast e.p.s.p. in neurones of sympathetic ganglia, elicited by a nicotinic action of acetylcholin...

journal_title：Nature

authors： Tosaka T,Tasaka J,Miyazaki T,Libet B

更新日期：1983-09-08 00:00:00

abstract：:Human T-cell leukaemia virus (HTLV), first isolated in the United States from a patient with cutaneous T-cell lymphoma, is a unique horizontally transmitted retrovirus which is highly associated with certain adult T-cell malignancies. Also, HTLV can be transmitted in vitro to cord blood T-lymphocytes. In the accompany...

journal_title：Nature

authors： Clarke MF,Gelmann EP,Reitz MS Jr

更新日期：1983-09-01 00:00:00

abstract：:UV light is a potent mutagen in most living cells, but molecular analysis of its mode of action in animal cells has not been possible because of the high complexity of the cell genome. Therefore, we have used simian virus 40 (SV40) as a biological probe to study the mutagenic effect of UV-irradiation at the molecular ...

journal_title：Nature

authors： Bourre F,Sarasin A

更新日期：1983-09-01 00:00:00