bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene analysis and its role in predicting susceptibility to disease
Authors: Humphries Steve , Barni Nazzarena 
Published: February 2005

AbstractRecombinant DNA technology can now be applied to the analysis of complex human diseases such as polygenic disorders, where the inheritance of several unknown genes appears to be involved. We review here the progress in the analysis of genes which may be involved in the development of hyperlipidaemia, and show how the approach may be important in our understanding of the aetiology of coronary artery disease.
Regulation of the methionine regulon in Escherichia coli
Authors: Shoeman Robert , Redfield Betty , Coleman Timothy , Brot Nathan , Weissbach Herbert , Greene Ronald C. , Smith Albert A. , Saint‐Girons Isabelle , Zakin Mario M. , Cohen Georges N. 
Published: February 2005

AbstractThe genes involved in methionine biosynthesis are scattered throughout the Escherichia coli chromosome and are controlled in a similar but not coordinated manner. The product of the metJ gene and S‐adenosylmethionine are involved in the repression of this ‘regulon’.
Long‐distance signal transfer in transcriptionally active chromatin – how does it occur?
Authors: Luchnik Andrey N. 
Published: February 2005

AbstractGene transcription in eukaryotes is associated with conformational changes of a large area of chromatin adjacent to a gene. This rearrangement may involve the whole loop (topological domain) to which a given gene belongs.Regulatory events associated with activation or inactivation of transcription are found to act through relatively short nucleotide sequences, often located several thousand base pairs apart from gene. These sequences, termed enhancers may act independently on their distance from or orientation with respect to the gene.Both long‐range conformational rearrangements of chromatin and any long distance effects of enhancers may be associated with elastic torsional strain in DNA, arising in transcriptionally active chromatin loops. Enhancer effects, in particular, may be associated with conformational transitions in DNA competing for the energy deposited in the elastic spring of the DNA.
Transcriptional enhancers play a major role in gene expression
Authors: Rogers Bruce L. , Saunders Grady F. 
Published: February 2005

AbstractTranscriptional enhancer sequences have been shown to play a pivotal role in the regulation of some highly expressed genes. First described in eukaryotic viruses, the discovery of enhancers has augmented the previously defined control‐sequence motifs to give a more complete understanding of eukaryotic transcriptional regulatory mechanisms. Some properties of enhancers that distinguish them from other regulatory sequences include their ability to function in a position‐ and orientation‐independent manner. Furthermore, the observation that some enhancers and transcriptional promoters exhibit tissue specificity in their activity has generated considerable interest. Enhancer activation is thought to involve sequence‐specific DNA‐binding proteins but the process by which this leads to an increase in the initiation of transcription remains obscure. Although viral enhancers are more fully characterized, several cellular enhancers have recently been identified. One such enhancer sequence has been detected in a 3′ flanking region of a highly expressed human placental lactogen gene. This enhancer can increase the transcriptional rate of an adjacent gene by at least 50‐fold.
Structural and functional domains on actin
Authors: Hambly Brett D. , Barden Julian A. , Miki Masao , Dos Remedios Cristobal G. 
Published: February 2005

AbstractActin plays several essential roles in cellular processes and is a vital component in the contractile apparatus. To accomplish its many cellular tasks, actin must interact with a wide range of other proteins in addition to self‐assembling into filaments. Characterization of these functional domains and localized binding regions on the actin monomer is therefore an important undertaking. Strategies for elucidating the many interaction sites include X‐ray diffraction, NMR and fluorescence spectroscopy, chemical modification, chemical cross‐linking, protein cleavage, and the study of sequence homologies between the many isotypes of actin. Based on these varied data, we discuss the possible spatial relationships between the interaction sites.
Cytoskeleton of embryonic skeletal muscle cells
Authors: Isobe Yuji , Shimada Yutaka 
Published: February 2005

AbstractCytoskeletal organization in embryonic skeletal muscle cells has been examined by transmission electron microscopy; the technique involves preparation using the platinum replication method of freezedried samples, with and without cryofracture. The cytoskeletons in developing muscle cells appear to play a role in preserving cell shape as well as in anchoring myofibrils to cell membrane.
The molecular biology of differentiation and proliferation using human myelogenous leukemia cells
Authors: Miller Carl , Koeffler H. Phillip 
Published: February 2005

AbstractCell lines and cell samples from patients provide opportunities for studying the mechanisms of leukemic cellular differentiation and proliferation. Phorbol esters and 1,25 dihydroxy vitamin D3 can induce differentiation of myeloid leukemic cells to macrophages. Differentiation to granulocytes can be induced by several different compounds. Myeloid differentiation is associated closely with the alteration in expression of several oncogenes. These regulatory events may be associated with the extent of methylation, unfolding or association of chromatin to the nuclear matrix. Oncogene amplification, mutation, or deletion can occur with malignant transformation. Future studies point to the development of specific pharmacological agents which can modify the neoplastic transformation.
The initiation of glycogen synthesis
Authors: Whelan William J. 
Published: February 2005

AbstractThe claim that glycogen contains protein was first made exactly 100 years ago and has been the subject of contention ever since. It has now been established that rabbit‐muscle glycogen contains a covalently bound protein of Mr 37,000, present in equimolar proportion to glycogen. The protein, named glycogenin, is joined to muscle glycogen via a novel linkage involving the hydroxyl group of tyrosine, a fact of possible significance in the light of insulin's message being transmitted by tyrosine phosphorylation. The protein is seen as the biogenetic precursor of glycogen. Its existence suggests an additional mode of regulation of glycogen metabolism since the amount, turnover and cellular location of glycogenin will influence the corresponding parameters for glycogen. A protein “primer” is suggested for the biogenesis of storage polysaccharides in general.
The role of actin polymerization in Amoebal Chemotaxis
Authors: Newell Peter C. 
Published: February 2005

AbstractA very rapid cellular event that follows chemotactic stimulation of leucocyte and cellular slime mould amoebae is a massive polymerization of G to F actin and its association with the cytoskeleton. In the cellular slime moulds this event occurs within 3–5 sec of cell surface binding of chemoattractants. It is correlated with rapid pseudopodium extension and may be a cell orientation mechanism. Curiously, before an amoebae moves away in the direction of its new pseudopodium it rounds up or “cringes” for 10–20 sec, an event correlated with a massive actin depolymerization. Transduction of the chemotactic signal involves Ca2+ release from internal stores by inositol trisphosphate.
Molecular approaches to the study of mesoderm formation in amphibians
Authors: Brennan Sean 
Published: February 2005

AbstractThe mesoderm is the region of the embryo that gives rise to muscle, blood and connective tissues; it becomes segregated from the ectoderm and endoderm at gastrulation. Embryological studies have revealed, however, that the potential for certain embryonic cells to become part of the mesoderm is established well before gastrulation, most likely through an extracellular signalling process termed ‘induction’. The recent characterization of mesoderm‐specific mRNAs and proteins now permits an analysis of the very earliest events involved in the specification of the mesoderm at the molecular level. Such experiments should contribute to our understanding of the mechanisms involved in controlling cell differentiation.
Types of moral argument against embryo research
Authors: Williams Bernard 
Published: February 2005

AbstractAlmost all moral objections to embryo research depend on one version or another of a slippery slope argument. There is one absolutist consideration which may be thought to decide the question independently of that argument, to the effect that the early embryo simply is a human being. But any plausible use of that consideration itself relies on the slippery slope argument. This argument may use either of two ideas (or both): that to distinguish between the two cases is not reasonable or that it will not be effective. The argument turns out to be very largely an empirical, consequentialist argument, and its application to early embryo research to rest on doubtful assumptions.
Oncogenes and cell cycle genes
Authors: Ferrari Sergio , Baserga Renato 
Published: February 2005

AbstractThe relationships between oncogenes, cell‐cycle control genes, and growth‐related genes are described. An important generalization from the data is that all the oncogenes and cell‐cycle control genes so far characterized appear to be genes for growth factors or for receptors to growth factors, or to be involved in the general metabolism and structure of the cell. It is suggested that the transition in cell growth from quiescence to the proliferative state, in early G1, may be less specific than previously thought and involve a general priming of the cells for more specific later stimuli.
Human genetics: The molecular challenge
Authors: Bodmer Walter F. 
Published: February 2005

AbstractThe 1986 Cold Spring Harbor Symposium was on the subject of human genetics; it was the first symposium at Cold Spring Harbor on this topic since 1964. In the opening remarks for the conference, Walter F. Bodmer first summarized the progress in this field since 1964. He then described what is presently known about the functional complexity of the human genome and discussed the case for a definitive characterization and sequencing of the human genome. The following is an abridged and slightly adapted version of this talk; it is reproduced courtesy of the Cold Spring Harbor Laboratory © 1987.
Dynamic instability of microtubules
Authors: Cassimeris L. U. , Walker R. A. , Pryer N. K. , Salmon E. D. 
Published: February 2005

AbstractRecent evidence shows that dynamic instability is the dominant mechanism for the assembly of pure tubulin in vitro and for the great majority of microtubules in the mitotic spindle and the interphase cytoplasmic microtubule complex. The basic concepts of this model provide a framework for future characterization of the molecular basis of spatial and temporal regulation of microtubule dynamics in the cell and the function of microtubule dynamics in motile processes such as chromosome movement.
Clonal heterogeneity in fibroblast phenotype: Implications for the control of epithelial‐mesenchymal interactions
Authors: Schor Seth L. , Schor Ana M. 
Published: February 2005

AbstractThe widespread distribution of fibroblasts underlines their central role in mammalian physiology, development and ageing. The existence of developmentally regulated and site‐specific phenotypic variation in fibroblasts is well documented. Recent evidence has revealed heterogeneity within the fibroblast population of a given tissue at a specified development stage. The relative proportion and tissue distribution of distinct fibroblast subsets must have important consequences in the control of connective tissue and adjacent epithelial functions in health and disease.
Memories of fos
Authors: Curran Tom , Morgan James I. 
Published: February 2005

AbstractInduction of c‐fos expression occurs following treatment of diverse cell types with agents that trigger mitogenesis, differentiation or membrane depolarization. We suggest that c‐fos may be regarded as a marker for a set of rapidly induced genes (termed cellular immediate‐early genes) whose function is to couple extracellular stimulation to long‐term responses. In the brain, these genes may contribute to the adaptive alterations involved in neuronal plasticity.
Ribosomal protein autoantibodies in systemic lupus erythematosus
Authors: Elkon Keith , Bonfa Eloisa , Skelly Susan , Weissbach Herbert , Brot Nathan 
Published: February 2005

AbstractAutoantibodies to three eukaryotic 60S ribosomal phosphoproteins P0, P1 and P2 have been found in the sera of 10–20% of patients with systemic lupus erythematosus (SLE). These three proteins share a common epitope contained within the carboxy terminal 22 amino acids of each protein. Because central nervous system disturbances, with major behavioural disorders, occur in a significant fraction of SLE patients, the antiribosomal autoantibodies were measured in this subset of SLE individuals to determine whether or not there was an association. This antibody is present in 90% of SLE patients who were diagnosed as having psychosis, secondary to the disease.
Regulation of chromosomal replication and transcription during early mammalian development
Authors: DePamphilis Melvin L. , Wassarman Paul M. 
Published: February 2005

AbstractMany principles of eukaryotic DNA replication and its relationship to transcription have been revealed by studying the replication of animal virus chromosomes. Now microinjection of viral DNA into eggs and embryos is providing clues about regulation of chromosomal replication and transcription during early mammalian development.
The membrane skeleton – A distinct structure that regulates the function of cells
Authors: Fox Joan E. B. , Boyles Janet K. 
Published: February 2005

AbstractIt has long been known that the red blood cell contains a membrane skeleton that stabilizes the plasma membrane, determines its shape, and regulates the lateral distribution of the membrane glyco‐proteins to which it is attached. The way in which these functions are regulated in other cells has not been understood. It has now been shown that platelets also contain a membrane skeleton. In contrast to the membrane skeleton of the red blood cell, the platelet membrane skeleton has actin‐binding protein, not spectrin, as a major component. The platelet membrane skeleton regulates the same cellular functions as the red blood cell membrane skeleton. Other cells may contain a membrane skeleton that is critical to their viability and normal functioning.
The role of the otu Gene in Drosophila oogenesis
Authors: King Robert C. , Storto Patrick D. 
Published: February 2005

AbstractThe ovarian tumor (otu) gene behaves as if it encodes a product (OGP) which is required during several early steps in the transformation of oogonia into functional oocytes. The ovarian phenotypes produced by various EMS‐induced mutations can be explained as graded responses by individual mutant germ cells to the different levels of functionally active OGP they themselves synthesize. In addition, genetic evidence suggests that otu also encodes a second product that is utilized late in oogenesis. Molecular studies of the otugene demonstrate that it does transcribe at least two ovaryspecific RNAs. The possible function of the otu product in the cellular divisions that give rise to the oocyte and its sister nurse cells is discussed.
Early embryogenesis in Caenorhabditis elegans: The cytoskeleton and spatial organization of the zygote
Authors: Strome Susan , Hill David P. 
Published: February 2005

AbstractEarly embryogenesis of Caenorhabditis elegans provides a striking example of the generation of polarity and the partitioning of cytoplasmic factors according to this polarity. Microfilaments (MFs) appear to play a critical role in these processes. By visualizing the distribution of MFs and by studying the consequences of disrupting MFs for short, defined periods during zygote development, we have generated some new ideas about when and how microfilaments function in the zygote.
Eukaryotic DNA replication reconstituted outside the cell
Authors: Blow J. Julian 
Published: February 2005

AbstractOur potential for dissecting the complex processes involved in eukaryotic DNA replication has been dramatically increased with the recent development of cell‐free systems that recreate many of these processes in vitro. Initial results from these systems have drawn together work on the cell cycle, the enzymology of replication, and the structure of the nucleus.
Expression of glycoconjugates during development of the vertebrate nervous system
Authors: Schwarting Gerald A. , Yamamoto Miyuki 
Published: February 2005

AbstractThere is increasing evidence that carbohydrate antigens act as cell recognition molecules in the highly organized structure of the nervous system. These carbohydrate antigens may be expressed as glycolipids, glycoproteins or proteoglycans, and in some cases all three forms of these glycoconjugates, expressing identical carbohydrate epitopes, can be detected in a specific brain region. This article summarizes recent studies concerning the expression of glycoconjugates during development of the vertebrate central nervous system. These findings are discussed in association with current models of glycoconjugate function.
Is there induced DNA repair in mammalian cells?
Authors: Denhardt David T. , Kowalski Jacek 
Published: February 2005

AbstractThe problem we discuss is whether mammalian cells possess genes whose expression is specifically enhanced by DNA damage in order to cope with the damage. The paradigm is the SOS response in E. coli. We conclude that there is compelling evidence that DNA‐damaging agents do affect gene expression, and that mutation frequencies are increased, but proof that a repair process per se is induced remains elusive. We offer here the hypothesis that recognition of the presence of DNA damage by poly(ADPribose) polymerase effects preprogrammed changes in gene expression.
recA‐dependent DNA repair processes
Authors: Smith Kendric C. , Wang Tzu‐Chien V. 
Published: February 2005

AbstractUV‐radiation‐induced lesions in DNA result in the formation of: (1) excision gaps (i.e. a lesion is excised, leaving a gap), (2) daughter‐strand gaps (i.e. a lesion can be skipped during replication, leaving a gap), and (3) double‐strand breaks (i.e. the DNA strand opposite a gap can be cut). In Escherichia coli, the recA gene product is involved in repairs of all three types of lesions – repair of daughter‐strand gaps (2) and double‐strand breaks (3) constitutes post‐replication repair. The evidence suggests, furthermore, that recA‐dependent repair of excision gaps (1) produced in DNA replicated prior to UV irradiation (pre‐replication repair) appears to occur by similar mechanisms.
Proteinase inhibitor gene families: Strategies for transformation to improve plant defenses against herbivores
Authors: Ryan Clarence A. 
Published: February 2005

AbstractRecent evidence indicates that the presence of serine proteinase inhibitors in plant leaves can reduce predation by insects. Plants can now be transformed with proteinase inhibitor genes with strong promoters to express the inhibitor proteins in relatively high levels at specific times. Inhibitors having variable specificities against digestive proteinases of insects and pathogens can now be assessed for their possible role(s) in natural plant defense and for their potential usefulness in protecting crop plants against herbivores.
The molecular biology of brain and mind development
Authors: Epstein Herman T. 
Published: February 2005

AbstractThe recent dramatic development of molecular neurobiology has focused almost entirely on biological events in individual brain cells, and it seems that many of the goals of such work will soon be attained. Yet, when we attain those goals, we will still have to ask how this information will enable us to understand the properties of brain cell collectivities and their presumptive roles in higher brain functions. Even general ideas about those functions are not yet well defined. Therefore, it seems worthwhile to start studying correlations of the molecular events to these higher functions to help delineate the molecular aspects that need study.It is readily appreciated that we cannot tell what other animal species see, hear, taste, smell and feel when touching something, though we can foresee the time when we will be able to detail the biochemical and biophysical consequences of all inputs to those senses. Thus, however deep our understanding of the biology of those species, we are unable to establish relations between their biological responses to inputs and their presumptive mental perceptions. Even though humans can use language to talk about those perceptions, we cannot even verify whether someone else's perceptions are the same as our own, as with the old question of whether two individuals see the same thing when viewing something blue. Questions about still higher mental functions of human brains are even less accessible to analysis and can be approached at best, by using correlations. In this article are a number of such questions and their current correlation‐level answers.
Focal contacts: Transmembrane links between the extracellular matrix and the cytoskeleton
Authors: Burridge Keith , Fath Karl 
Published: February 2005

AbstractThe sites of tightest adhesion that form between cells and substrate surfaces in tissue culture are termed focal contacts. The external faces of focal contacts include specific receptors, belonging to the integrin family of proteins, for fibronectin and vitronectin, two common components of extracellular matrices. On the internal (cytoplasmic) side of focal contacts, several proteins, including talin and vinculin, mediate interactions with the actin filament bundles of the cytoskeleton. The changes that occur in focal contacts as a result of viral transformation are discussed.
Food, reproduction and L'ongevity: Is the extended lifespan of calorie‐restricted animals an evolutionary adaptation?
Authors: Holliday Robin 
Published: February 2005

AbstractCalorie restriction results in an increased lifespan and reduced fecundity of rodents. In a natural environment the availability of food will vary greatly. It is suggested that Darwinian fitness will be increased if animals cease breeding during periods of food deprivation and invest saved resources in maintenance of the adult body, or soma. This would increase the probability of producing viable offspring during an extended lifespan. The diversion of limited energy resources from breeding to maintenance of the soma is seen as an evolutionary adaptation, fully compatible with the ‘disposable soma’ theory of the evolution of ageing.
Metabolic Compartmentation
Authors: Spivey H. O. , Merz J. M. 
Published: February 2005

AbstractEvidence for the association of ‘soluble’ enzymes in vivo is extensive and compelling. These associations occur in all compartments of the cell of both prokaryotes and eukaryotes. Several factors present in vivo promote these associations among enzymes whose association in vitro is often too weak to detect. Several physiological advantages of the associated enzyme complexes can be identified, most (but not all) of which are the consequence of microcompartmentation of metabolites (substrate channeling). Substrate channeling of intermediates by either a ‘direct transfer’ process or ‘proximity effects’ can occur. The latter mechanism does not require the special molecular features needed for the direct transfer mechanism and may, therefore, exist in more general situations in the cell. Criticisms of these views are discussed. We argue that these criticisms have been largely answered by experiment and theory in recent years. Studies on simple systems in vitro, nevertheless, contribute important insights concerning the more complex phenomena in vivo.