abstract：:We have shown previously that chemically skinned fibre bundles from scallop muscle can be desensitized to the action of calcium by the removal of the regulatory light chains of myosin and that sensitivity can be restored by the re-addition of scallop light chains. We have now confirmed these results and extended our o...

journal_title：Nature

authors： Simmons RM,Szent-Györgyi AG

更新日期：1980-08-07 00:00:00

abstract：:Phosphorylation of membrane components is thought to be an important process in membrane function. Phosphorylated proteins and a special class of phospholipids, the (poly)phosphoinositides (poly PI), are implicated in the regulation of membrane permeability and synaptic transmission in neurones. For many years, protei...

journal_title：Nature

authors： Jolles J,Zwiers H,van Dongen CJ,Schotman P,Wirtz KW,Gispen WH

更新日期：1980-08-07 00:00:00

abstract：:The biochemical and morphological differentiation of actinomycetes makes them academically and economically interesting. Their secondary metabolites provide the majority of medically and agriculturally important antibiotics (streptomycete genes may also be the primary source of clinically important antibiotic resistan...

journal_title：Nature

authors： Thompson CJ,Ward JM,Hopwood DA

更新日期：1980-07-31 00:00:00

abstract：:Seven monoclonal antibodies have been produced against a membrane preparation from adult rat retina. Three antibodies reacted with particular regions of rat photoreceptor cell surfaces: RET-P1 labelled the cell bodies, outer and inner segments (rods but not cones), RET-P2 labelled only outer segments and RET-P3 labell...

journal_title：Nature

authors： Barnstable CJ

更新日期：1980-07-17 00:00:00

abstract：:Arachidonic acid is metabolised either by cyclooxygenases to produce prostaglandins and thromboxanes or by lipoxygenases to produce mono-, di- and trihydroxyeicosatetraenoic acids (HETEs). Polymorphonuclear leukocytes (PMNs) release HETEs, including mono- and dihydroxy fatty acids, when exposed to stimuli such as the ...

journal_title：Nature

authors： Ford-Hutchinson AW,Bray MA,Doig MV,Shipley ME,Smith MJ

更新日期：1980-07-17 00:00:00

abstract：:The capacity of the rough endoplasmic reticulum (RER) membrane of eukaryotic cells in translocate nascent presecretory proteins from the cytosol to the intracisternal space is preserved on cell fractionation and can be assayed in vitro. Two attempts to characterize this translocation activity have been reported. Warre...

journal_title：Nature

authors： Jackson RC,Walter P,Blobel G

更新日期：1980-07-10 00:00:00

abstract：:Nerve growth factor (NGF) activity was not detected by bioassay in irides killed immediately after excision but NGF appeared within 24 h in living irides placed in culture or grafted to a host eye. Furthermore, sensory and, although less effective, sympathetic denervation of irides in situ led within 10 days to the ap...

journal_title：Nature

authors： Ebendal T,Olson L,Seiger A,Hedlund KO

更新日期：1980-07-03 00:00:00

abstract：:In Drosophila, a large group of structural genes exhibit coordinate regulation, not because they function in a common developmental pathway but because they happen to reside on the X chromosome. These genes are subjected to the regulatory mechanism of dosage compensation which insures that their phenotypic products ar...

journal_title：Nature

authors： Belote JM,Lucchesi JC

更新日期：1980-06-19 00:00:00

abstract：:The expression of immunodeficiency in patients with specific purine enzyme defects indicates a crucial role of the purine salvage pathway in the acquisition and expression of normal immune function. One current hypothesis links the failure of normal lymphocyte development in these diseases to the accumulation of deoxy...

journal_title：Nature

authors： Dosch HM,Mansour A,Cohen A,Shore A,Gelfand EW

更新日期：1980-06-12 00:00:00

abstract：:Naturally occurring peptides with biological actions have in most cases been detected by observing their biological activities in crude extracts and their isolation has been followed using bioassays. As a complement to the classical biological detection systems, we have proposed a chemical detection system based on fr...

journal_title：Nature

authors： Tatemoto K,Mutt V

更新日期：1980-06-05 00:00:00

abstract：:More than 50 copies of a phi X174 DNA template can be made in 60 min in an in vitro DNA replication system consisting of seven purfied replication proteins isolated from T4 bacteriophage-infected cells. By transfecting with the DNA products and assaying for the reversion of specific amber mutants, the high degree of b...

journal_title：Nature

authors： Hibner U,Alberts BM

更新日期：1980-05-29 00:00:00

abstract：:There is ample evidence that the secretion of follicle stimulating hormone (FSH) by the pituitary gland is regulated by a nonsteroidal hormone of gonadal origin, termed inhibin. In several species, testicular extracts, gonadal lymph and seminal plasma have been shown to contain proteins which inhibit FSH release; lack...

journal_title：Nature

authors： Scott RS,Burger HG

更新日期：1980-05-22 00:00:00

abstract：:The DNA synthetic (S) phase of cell division is about twice as long in human basal cell carcinoma (BCC) as the normal epidermis and several non-malignant skin diseases. A similar increase in S phase duration seems to occur in tumours of the human oesophagus, larynx and recto-colon. At the molecular level, the overall ...

journal_title：Nature

authors： Heenen M,Galand P

更新日期：1980-05-22 00:00:00

abstract：:Ionic currents from individual K+ channels in squid axon membrane have been recorded. At hyperpolarizing membrane voltages, unit events occur as widely spaced rectangular pulses with short interruptions. The frequency of occurrence of the units increases strongly when the membrane is depolarized. ...

journal_title：Nature

authors： Conti F,Neher E

更新日期：1980-05-15 00:00:00

abstract：:The direct involvement of the pituitary-adrenal axis in birth has been well established, at least in sheep, and its removal prolongs pregnancy. As part of the process the fetal sheep adrenal grows rapidly during the 10-15 d prepartum and is associated with a large rise in the plasma corticosteroid concentration. This ...

journal_title：Nature

authors： Roebuck MM,Jones CT,Holland D,Silman R

更新日期：1980-04-17 00:00:00

abstract：:DNA fragments of chemically transformed and normal avian and murine cells induce transformation of NIH 3T3 mouse cells with low efficiencies. High molecular weight DNAs of cells transformed by DNA fragments induce transformation with high efficiencies in secondary transfection assays. It thus seems that endogenous tra...

journal_title：Nature

authors： Cooper GM,Okenquist S,Silverman L

更新日期：1980-04-03 00:00:00

abstract：:The onsert of neuronal differentiation is characterised by intensive neurite growth; because microtubule formation is strictly required during this process, in vitro assembly of the tubulin present in the rat brain has been studied at different stages of development: the rate of assembly is very slow in the early stag...

journal_title：Nature

authors： Mareck A,Fellous A,Francon J,Nunez J

更新日期：1980-03-27 00:00:00

abstract：:The carotid body type I cell contains amines and has features, both morphological and cytochemical, which indicate that it may also produce a peptide. Many regulatory peptides are now known to be present in both central and peripheral tissues. In the periphery these neuropeptides occur in both classical endocrine (APU...

journal_title：Nature

authors： Wharton J,Polak JM,Pearse AG,McGregor GP,Bryant MG,Bloom SR,Emson PC,Bisgard GE,Will JA

更新日期：1980-03-20 00:00:00

abstract：:The interaction of lectins with carbohydrate receptors on the plasma membrane of eukaryotic cells results in a wide variety of biological effects. One effect which has been extensively studied is the stimulation of lymphocytes to blastogenesis and proliferation. High doses of concanavalin A (Con A) and phytohaemagglut...

journal_title：Nature

authors： Hilgert I,Horejsí V,Angelisová P,Kristofová H

更新日期：1980-03-20 00:00:00

abstract：:In general, heterozygous animal cells express both alleles at a particular locus. The only exceptions are cells of XX genotype after inactivation of one X chromosome, and immunoglobulin-producing cells; in each case only one of the two alleles is expressed in differentiated cells and their progeny. This phenomenon, te...

journal_title：Nature

authors： Joho R,Weissman IL

更新日期：1980-03-13 00:00:00

abstract：:In photoreceptors, a latency of many milliseconds elapses between the absorption of a light quantum and the occurrence of the late receptor potential, even for strong light stimuli. Surprisingly, this is much longer than the time necessary for conductance changes such as occur in membranes of neurones or muscles, medi...

journal_title：Nature

authors： Hamdorf K,Kirschfeld K

更新日期：1980-02-28 00:00:00

abstract：:The induction of polyarthritis in rats by intradermal immunisation with homologous or heterologous type II collagen incomplete or incomplete Freund's adjuvant was reported recently by Trentham et al. We have now produced a similar disease in certain strains of mice. ...

journal_title：Nature

authors： Courtenay JS,Dallman MJ,Dayan AD,Martin A,Mosedale B

更新日期：1980-02-14 00:00:00

abstract：:The molecular and cellular basis of T-lymphocyte activation remains a central question in immunology. The growth of already proliferating T cells is known to depend on T-cell growth factor (TCGF), a physiological mitogen. Noncycling T lymphocytes, however, are not sensitive to TCGF. They require a short contact with m...

journal_title：Nature

authors： Larsson EL,Iscove NN,Coutinho A

更新日期：1980-02-14 00:00:00

abstract：:Human lymphocytes have been shown to lyse in vitro a large variety of target cells derived from tumour as well as normal tissues. The effector cells involved in this spontaneous cell-mediated cytotoxicity (SCMC) have generally been characterised as lymphocytes which lack surface membrane immunoglobulin (sIg) and lack ...

journal_title：Nature

authors： de Vries JE,Mendelsohn J,Bont WS

更新日期：1980-02-07 00:00:00

abstract：:Temperature-dependent transition of conductance in ionic channels has been described in several membrane systems. We report here an abrupt change in the maximal rate of rise of the action potentials of the rat extensor digitorum longus (EDL) at 32 degrees C, indicating alteration in the functional characteristics of t...

journal_title：Nature

authors： Cheung DW,Daniel EE

更新日期：1980-01-31 00:00:00

abstract：:The variable regions of mouse kappa (kappa) chains are coded for by multiple variable (V) gene segments and multiple joining (J) gene segments. The V kappa gene segments code for residues 1 to 95; the J kappa gene segments code for residues 96 to 108 (refs 1-3). This gene organisation is similar to that encoding the V...

journal_title：Nature

authors： Weigert M,Perry R,Kelley D,Hunkapiller T,Schilling J,Hood L

更新日期：1980-01-31 00:00:00

abstract：:Adult newts regenerate functional limbs after amputation. This process normally depends on the trophic influence of nerves on the regenerating limbs, particularly in the early stages before differentiation of the regeneration blastema, when it stimulates growth by maintaining high rates of macromolecular synthesis. Th...

journal_title：Nature

authors： Rathbone MP,Petri J,Choo AF,Logan DM,Carlone RL,Foret JE

更新日期：1980-01-24 00:00:00

abstract：:The extent of allelic variation has been estimated at 46 structural gene loci within three major colonies of Swiss mice and between inbred derivative strains. The colonies have retained nearly the same amount and type of variation found in natural murine or human populations despite laboratory propagation for more tha...

journal_title：Nature

authors： Rice MC,O'Brien SJ

更新日期：1980-01-10 00:00:00

abstract：:It is generally thought that interspecific (lateral) transfer of genes is so extensive among bacteria that it is difficult, and perhaps impossible, to determine their phylogenetic relationships. Ambler and coworkers reflect this in their suggestion that the relationships seen among cytochrome c sequences of the Rhodos...

journal_title：Nature

authors： Woese CR,Gibson J,Fox GE

更新日期：1980-01-10 00:00:00

abstract：:The intracellular free Ca2+ ([Ca2+]i) regulates the K+ conductance (GK) of the many types of cell membrane. The Ca2+ influx during an action potential activates this [Ca2+]i-linked GK in most neurones. In caffeine-treated sympathetic ganglion cells, however, Ca2+ released from an intracellular Ca2+ reservoir site anal...

journal_title：Nature

authors： Morita K,Koketsu K,Kuba K

更新日期：1980-01-10 00:00:00

abstract：:Visual transduction in vertebrate photoreceptors is thought to involve a diffusible internal transmitter which links photon absorption in disk membranes to the conductance decrease in the plasma membrane of the outer segment. The desensitisation of the photoresponse which occurs during and after illumination may also ...

journal_title：Nature

authors： McNaughton PA,Yau KW,Lamb TD

更新日期：1980-01-03 00:00:00

abstract：:Fibres in the mammalian optic nerve are generally thought to be organised retinotopically. Recording electrophysiologically from the cat optic nerve, we found little evidence to support this notion, which led us to investigate the problem by anatomical methods. We made a localised injection of horseradish peroxidase i...

journal_title：Nature

authors： Horton JC,Greenwood MM,Hubel DH

更新日期：1979-12-13 00:00:00

abstract：:Mice of the AKR strain are characterised by a high incidence of spontaneous thymic lymphomas. AKR chromosomes contain the genomes of ecotropic murine leukaemia virus (MuLV) at two loci, termed Akv-1 and Akv-2 (refs 2-6). Shortly after birth, the normal tissues of AKR mice begin to produce high levels of this XC-positi...

journal_title：Nature

authors： Rein A,Athan E,Benjers BM,Bassin RH,Gerwin BI,Slocum DR

更新日期：1979-12-13 00:00:00

abstract：:The brain has generally been considered an insulin-independent organ, because insulin does not apparently exert a direct effect on brain glucose consumption. Recently, however, insulin receptors have been detected throughout the central nervous system (CNS) of several species. Since important insights into the functio...

journal_title：Nature

authors： van Houten M,Posner BI

更新日期：1979-12-06 00:00:00

abstract：:Interactions between animal viruses and antiviral antisera may exceptionally result in an apparent increase in viral infectivity. Halstead and coworkers demonstrated enhanced replication of dengue virus (a Flavivirus, family Togaviridae) in human or simian peripheral blood leucocytes carrying Fc receptors at subneutra...

journal_title：Nature

authors： Peiris JS,Porterfield JS

更新日期：1979-11-29 00:00:00

abstract：:Immunoprecipitation and tryptic peptide analysis of newly synthesized proteins from rat islets have identified an 18,000 molecular weight (MW) protein as proglucagon. Conversion of this precursor was kinetically similar to the conversion of proinsulin and resulted in the formation of both pancreatic glucagon and a 10,...

journal_title：Nature

authors： Patzelt C,Tager HS,Carroll RJ,Steiner DF

更新日期：1979-11-15 00:00:00

abstract：:Multiple sulphatase deficiency disease is an unusual autosomal recessive disorder characterised biochemically by a deficiency of several sulphohydrolase activities. The laboratory diagnosis of this combined neurological connective tissue disorder is made on the basis of decreased activities of the lysosomal enzymes, a...

journal_title：Nature

authors： Fiddler MB,Vine D,Shapira E,Nadler HL

更新日期：1979-11-01 00:00:00

abstract：:A characteristic feature of induced pinocytosis in Amoeba proteus is the formation of broad channels by invagination of the cell membrane. This process, which requires Ca2+, occurs in response to depolarising cations. High Ca2+ levels reduce pinocytosis induced by cations such as Na+ and Tris+, whereas pinocytosis ind...

journal_title：Nature

authors： Josefsson JO,Johansson P

更新日期：1979-11-01 00:00:00

abstract：:Various mechanisms have been proposed for beta-adrenergically mediated relaxation of smooth muscle. All theories suggest the involvement of cyclic AMP as a second messenger: beta-agonists stimulate adenylate cyclase which converts ATP to cyclic AMP and protein kinase, activated by cyclic AMP, is then thought to cataly...

journal_title：Nature

authors： Mueller E,van Breemen C

更新日期：1979-10-25 00:00:00

abstract：:Dense plexuses of neurones containing immunoreactive vasoactive intestinal peptide (VIP) have been found in discrete areas of the central nervous system and in peripheral organs, including the gastrointestinal tract, pancreas and urogenital system. In many of these locations VIP is concentrated in nerve endings, where...

journal_title：Nature

authors： Giachetti A,Said SI

更新日期：1979-10-18 00:00:00