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PubMed1998

Regulation and function of DNA methylation in vertebrates.

In vertebrates, genomic DNA is often methylated at the 5th position of cytosine in the sequence of CpG, and this is the only chemical modification that genomic DNA of vertebrates allows under physiological conditions. During evolution, vertebrates acquired CpG methylation as a new tool for controlling gene expression in addition to the varieties of transcription factors. In mammals, the methylation pattern of genomic DNA is erased and reset in germ line and at the early stage of embryogenesis. Maintenance-type methylation activity ensures clonal transmission of the lineage-specific methylation pattern in somatic cells. The methylation pattern is dynamic and changes during cell differentiation. Prior to the expression of tissue-specific genes, specific sites of the promoters are demethylated. In general, the methylation of a gene suppresses its expression. However, not much is known about the mechanisms that regulate the methylation state and the gene expression by DNA methylation.

Amino Acid Sequence↗

PubMed1988

[Iatrogenic diseases and scientific and technical progress].

Evolution of the term "iatrogenesis" and a widening range of the diseases varying in origin and clinical appearance covered with this term are considered. It is emphasized that such interpretation misrepresents the primary meaning aimed at orientation of the physicians to evaluation of the patient and doctor personality in view of its role in the genesis of psychic and somatic disturbances which tends to loom large with further scientific and technological progress. Iatrogenesis is supposed to be relevant to pathomorphosis of the borderline psychic conditions, prenosologic diagnosis and screening of population, drug addiction and alcoholism management. There is a tendency to further introduction of technical aspects into medical education.

Humans↗

PubMed1984

Autoimmune thyroid disease: an integrated concept of Graves' and Hashimoto's diseases.

Graves' disease and Hashimoto's thyroiditis have been previously considered separate clinical and pathologic entities. Current knowledge of the autoimmune cause of specific systemic syndromes has been applied to these seemingly dissimilar diseases and now permit evolution of a unified integrated concept for considering them as two subsets of a single pathologic process. Experimental and clinical data now support the thesis that autoimmune thyroid disease is a genetically conditioned immunologic dysfunction, perhaps an abnormality of suppressor lymphocytes that results in production of humoral and tissue antibodies directed against thyroid gland cells and receptors of other somatic tissues. Thyroid autoantibodies possess hormonally stimulatory qualities and cytotoxic (inflammatory or destructive) properties. They may be present singly or together in the same individual with resulting diverse clinical and biochemical patterns depending upon the predominance or concordance of specific antibodies. Further, antibodies in autoimmune thyroid disease may be directed against other somatic structures such as ocular muscle, skin, hair, pigment cells, hematologic organs, or other endocrine glands. The immune etiology appears to predispose to nonendocrine systemic autoimmune disorders that coincide with thyroid disease. It is not clear at this time how genetic factors influence the onset, course, or ultimate outcome of autoimmune thyroid disease or why certain associated immunopathies tend to cluster with one or the other of these syndromes. Our understanding of the immune etiology common to Graves' and Hashimoto's diseases permits a more precise definition of the terms hyperthyroidism and thyrotoxicosis, the former denoting a pathologic goitrous phenomenon and the latter, a peripheral tissue manifestation of cellular receptor site excess of thyroid hormones.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1996

Evolution of mammalian X-linked and autosomal Pgk and Pdh E1 alpha subunit genes.

The phylogeny and substitution rates of the mammalian X chromosome-located and autosomal phosphoglycerate kinase and pyruvate dehydrogenase genes were investigated. Compatibility analysis was used to show reticulate evolution in these genes. Analysis of the marsupial, mouse, and human phosphoglycerate kinase genes suggests that at least two recombination events have taken place, one occurring about the time of the placental-marsupial split involving exons 1-5 and the other before the primate-rodent split involving exons 9-10. Similar analysis of the pyruvate dehydrogenase genes indicates a recombination event involving exons 2-3 at a time before the primate-rodent split and a gene conversion between exons 3-4 in the human somatic and testis-specific pyruvate dehydrogenase genes after the primate-rodent split. This demonstrates that genetic exchange can occur between paralogous genes at widely separated chromosomal locations. Estimation of nucleotide substitution rates in these genes confirmed a higher substitution rate in the pyruvate dehydrogenase genes. In the phosphoglycerate kinase genes, there is no difference between the substitution rates in mice and humans and between the X chromosome- and autosome-located genes. A greater substitution rate was noted in the mouse autosomal pyruvate dehydrogenase gene when compared with the other mouse and human genes. This may be a result of either directional natural selection or a relaxation of functional constraint at this specific gene.

Animals↗

PubMed1990

Novel use of a chimpanzee pseudogene for chromosomal mapping of human cytochrome c oxidase subunit IV.

We have isolated a chimpanzee processed pseudogene for subunit IV of cytochrome c oxidase (COX; EC 1.9.3.1) by screening a chimpanzee genomic library in lambda Charon 32 with a bovine liver cDNA encoding COX subunit IV (COX IV), and localized it to a 1.9-kb HindIII fragment. Southern-blot analysis of genomic DNA from five primates showed that DNAs from human, gorilla, and chimpanzee each contained the 1.9-kb pseudogene fragment, whereas orangutan and pigtail macaque monkey DNA did not. This result clearly indicates that the pseudogene arose before the divergence of the chimpanzee and gorilla from the primate lineage. By screening Chinese hamster x human hybrid panels with the human COX4 cDNA, we have mapped COX4 genes to two human chromosomes, 14 and 16. The 1.9-kb HindIII fragment containing the pseudogene, COX4P1, can be assigned to chromosome 14, and by means of rearranged chromosomes in somatic cell hybrids, to 14q21-qter. Similarly, the functional gene, COX4, has been mapped to 16q22-qter.

Amino Acid Sequence↗

PubMed1997

Characterization and expression of two chicken cDNAs encoding ubiquitin fused to ribosomal proteins of 52 and 80 amino acids.

We have determined the complete nucleotide sequence of two chicken cDNAs, Ub-t52 and Ub-t80, encoding ubiquitin fused to ribosomal proteins of 52 and 80 amino acids. The deduced amino acid sequences of the ribosomal proteins are identical or very similar to the homologous human and rat proteins and to the corresponding proteins of other species. Unexpectedly, the ubiquitin moiety of the Ub-t52 protein showed two amino acid substitutions: serine-20 has been replaced by asparagine and serine-57 by alanine. Ubiquitin is a protein strongly conserved during evolution, with no changes in sequence previously reported in vertebrates. Ub-t52 and Ub-t80 are highly expressed in early embryogenesis and during postmitotic stages of spermatogenesis, in parallel with the expression of the polyubiquitin gene UbII. Whereas the 5' untranslated regions (5'UTRs) of the chicken polyubiquitin mRNAs showed marked differences in mature testes in relation to somatic tissues, no differences were observed in the 5'UTRs of the ubiquitin-ribosomal protein mRNAs. These mRNAs possess a 5'-terminal oligopyrimidine tract that could be used as a mechanism to postpone translation during postmitotic stages of spermatogenesis, as has been proposed in quiescent cells.

Alanine↗

PubMed2001

Complex organization of promoter and enhancer elements regulate the tissue- and developmental stage-specific expression of the Drosophila melanogaster Gld gene.

The Drosophila melanogaster Gld gene has multiple and diverse developmental and physiological functions. We report herein that interactions among proximal promoter elements and a cluster of intronically located enhancers and silencers specify the complex regulation of Gld that underlies its diverse functions. Gld expression in nonreproductive tissues is largely determined by proximal promoter elements with the exception of the embryonic labium where Gld is activated by an enhancer within the first intron. A nuclear protein, GPAL, has been identified that binds the Gpal elements in the proximal promoter region. Regulation of Gld in the reproductive organs is particularly complex, involving interactions among the Gpal proximal promoter elements, a unique TATA box, three distinct enhancer types, and one or more silencer elements. The three somatic reproductive organ enhancers each activate expression in male and female pairs of reproductive organs. One of these pairs, the male ejaculatory duct and female oviduct, are known to be developmentally homologous. We report evidence that the other two pairs of organs are developmentally homologous as well. A comprehensive model to explain the full developmental regulation of Gld and its evolution is presented.

Animals↗

PubMed1997

Théodule Ribot and the reception of evolutionary ideas in France.

Although the French scientific community was reluctant to honour Darwin for his work, the eminent psychologist Théodule Ribot used an evolutionary framework for his thesis on heredity. The publication of L'Hérédité psychologique in 1873 was intended for lay readers at a period in French history when many scientific topics were popular. As a result French readers were introduced to the Darwinian and Spencerian ideas that Ribot included -- as an analysis of L'Hérédité shows. This work was important for French psychology and psychiatry: it extended the domain of the former, and by endorsing degeneracy theory provided alienists with a scientific explanation of mental pathology which a somatic approach had failed to discover. L'Hérédité is a synthesis of biology, exolutionary ideas and the features of heredity, addressed and related to social concerns of the last three decades of nineteenth-century France.

Biological Evolution↗

PubMed1988

Karyotype evolution of the human HBL-100 cell line and mapping of the integration site of SV40 DNA.

Cytogenetic analysis of the human HBL-100 cell line, that we have previously shown to harbour SV40 genetic information (Caron de Fromentel et al., 1985), reveals numerous chromosomal rearrangements as soon as the 30th in vitro passage. The karyotype is relatively stable during in vitro maintenance and even at late passages (approximately 70) when the cells have acquired the capacity to form tumors in nude mice. In all the somatic cell hybrids obtained after fusion of mouse 3T3-4E cells with HBL-100 cells, several human chromosomes are maintained and a derivative from chromosome 15-der(15)- is the most frequently observed. The der(15) marker is present in the HBL-100 cell line at every passage studied as well as in different cell lines derived from tumors induced by HBL-100 cells. The various hybrids, originally isolated for a transformed phenotype on the basis of their ability to grow in soft-agar, were all found to express the SV40 T-antigen. In situ hybridization of an SV40 DNA probe to chromosome spreads obtained from one of these hybrids shows that the integration site of the viral genome is located on the der(15) marker chromosome, at band 15q24. The possible cooperation of SV40 T-antigen with some other oncogene(s), required by human HBL-100 cells in order to express a malignant phenotype, is discussed.

Cell Line↗

PubMed1985

Evolution and organization of the fibrinogen locus on chromosome 4: gene duplication accompanied by transposition and inversion.

Human fibrinogen cDNA probes for the alpha-, beta-, and gamma-polypeptide chains have been used to isolate the corresponding genes from human genomic libraries. There is a single copy of each gene. Restriction endonuclease analysis of isolated genomic clones and human genomic DNA indicates that the human alpha-, beta-, and gamma-fibrinogen genes are closely linked in a 50-kilobase region of a single human chromosome: the alpha-gene in the middle flanked by the beta-gene on one side and the gamma-gene on the other. The alpha- and gamma-chain genes are oriented in tandem and transcribed toward the beta-chain gene. The beta-chain gene is transcribed from the opposite DNA strand toward the gamma- and alpha-chain genes. The three genes have been localized to the distal third of the long arm of chromosome 4, bands q23-q32, by in situ hybridization with fibrinogen cDNAs and by examination of DNA from multiple rodent-human somatic cell hybrids. Alternative explanations for the present arrangement of the three fibrinogen genes involve either a three-step mechanism with inversion of the alpha/gamma-region or a two-step mechanism involving remote transposition and inversion. The second more simple mechanism has a precedent in the origin of repeated regions of the fibrinogen and immunoglobulin genes.

Biological Evolution↗

PubMed1997

The within-host population dynamics of antibacterial chemotherapy: conditions for the evolution of resistance.

For tuberculosis and number of other bacterial infections, treatment with a single antimicrobial drug frequently fails due to the ascent of mutants resistant to that drug. To minimize the likelihood of this occurrence, multiple drugs with independent resistance mechanisms are used simultaneously. None the less, multiply resistant bacteria sometimes emerge even when patients are simultaneously treated with two or more drugs, and the ascent of these multiply-resistant mutants may result in treatment failure in the patient and spread of these resistant bacteria to other hosts. We consider two mathematical models of antibacterial chemotherapy which can account for the ascent of multiple antibiotic resistance within hosts treated with multiple antibiotics. In both, multiple resistance evolves because of selection favouring mutants resistant to fewer than all of the chemotherapeutic agents employed, intermediates. In one model, this occurs because of temporal fluctuations in the concentrations of the antibiotics in the course of normal treatment and/or because of non-adherence to the treatment regime. In the other, intermediates are favoured and multiple resistance evolves because of tissue and somatic cell heterogeneity. In the effective concentrations of the antibiotics and physiological variation in the sensitivity of subpopulations of bacteria to different antibiotics. We discuss the limitations (and assets) of this model and approach and the implications for the design of antibiotic treatment regimes. Finally, we consider how the assumptions behind this model and the predictions made from its analysis could be tested experimentally.

Animals↗

PubMed2001

Bipolar disorders: new approaches to therapy.

This article reviews the evidence supporting different somatic treatment strategies in the acute and maintenance treatment phases of bipolar disorder. Bipolar affective disorder is a chronic disorder with a life time incidence of 0.3 - 1.5/100 [1]. Severe affective disorder is associated with a risk of completed suicide of 6 - 15% [2,3]. Traditionally, bipolar disorder has been considered as an episodic disorder with good inter-episode recovery [4]. This is being increasingly challenged with patients demonstrating social, marital, occupational and cognitive dysfunction, even when euthymic [5]. The management of bipolar disorder should be considered in the context of; the type of episode, this may be manic, depressed or mixed; the degree and rate of recovery; the cycling frequency and precipitant, if any, for recurrence and the onset and evolution of the underlying illness. On average, four episodes occur every 10 years. However 13 - 24% of patients develop rapid cycling disorder, in which four or more episodes occur within a year. Patients with bipolar disorder often have co-morbid anxiety and substance abuse. Moreover, axis I co-morbidity may be associated with an earlier age at onset and worsening course of bipolar illness. [6]. Axis II co-morbidity is also common, this was highlighted in a study by Kay and colleagues who, after excluding patients with a history of alcohol misuse, demonstrated axis II co-morbidity in almost a quarter of euthymic bipolar patients [7]. Good practice relies on an overall management plan that incorporates somatic, psychological and social approaches. This paper will focus on one element of such a plan, the currently available somatic management strategies for bipolar disorder.

Anticonvulsants↗

PubMed2001

Population variation in children's behavioral symptomatology.

Previous anthropological studies identified significant interpopulation consistencies in the frequency and symptoms of adult depression, anxiety, and schizophrenia. Tests of the degree of variation of such behavioral phenomena across contemporary populations are significant for the study of human evolution because universality or near universality suggests specific evolved aspects of human behavior. The aim of this research was to provide a preliminary test of whether cross-cultural consistencies in symptomatology associated with some psychiatric conditions are observable in children as they are in adults. We tested for interpopulation variation in degrees (intensity and frequency) of anxiety, depression, withdrawal, and somatization symptomatology in normal samples of children. Psychometric ratings scales allowed assessment of characteristic symptomatology of each child in the different contexts of home and school. The study populations comprised 1,208 6-11-year-old children from the Paisa community in Antioquia, Colombia, and African-American, Euro-American, and Hispanic children in the United States. We found interpopulation consistencies in some aspects of child behavioral symptomatology, especially depression and withdrawal. Mean degrees of symptomatology and percentages of children with clinically significant levels of symptomatology were consistent for both across populations, in home and school contexts, and for both girls and boys. Anxiety and somatization displayed more cross-cultural variability in expression. These patterns are in accordance with current understandings of cross-cultural variability and universals of adult psychiatric symptomatology.

Child↗

PubMed2026

Integrative single-cell and genomic analysis reveals NMB as a driver of metastatic adaptation in esophageal squamous cell carcinoma via metabolic rewiring and immune evasion.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) has high mortality, and metastasis is the leading cause of patient death. Neuromedin B (NMB) promotes tumor development in various cancers, yet its role in ESCC metastasis remains unclear. METHODS: We integrated single-cell transcriptomic data from matched primary and metastatic ESCC lesions (GSE309392) with bulk transcriptomic cohorts from TCGA and GSE53624. In silico gene perturbation, ligand-receptor communication analysis, and single-cell prognostic model construction were performed, followed by functional validation through siRNA-mediated NMB knockdown in TE-1 and KYSE30 cell lines. RESULTS: NMB was identified as a key gene enriched in metastatic ESCC lesions, and its high expression was associated with coordinated upregulation of oxidative phosphorylation pathway genes and aldo-keto reductase family antioxidant enzymes (AKR1C1, AKR1C2, AKR1B10). Genomic analysis revealed that NMB-high tumors carried a higher clonal mutation burden and a markedly increased frequency of NFE2L2 activating mutations (23% vs. 8%, P = 0.04). In silico knockout and correlation analysis identified AKR1C1 as a downstream effector of NMB. NMB expression was negatively correlated with CD8+ T cell and activated NK cell infiltration. CellChat analysis revealed communication between NMB-positive cells and monocytes via the TGM2-ADGRG1 axis, and specifically detected IFNG signaling. In the single-cell prognostic model, NMB-positive cells accounted for 50% of the high-risk group but only 20% of the low-risk group. TCGA-based survival analysis demonstrated that high NMB expression was associated with shorter overall survival (HR = 2.98, P = 0.03). In vitro NMB-targeted RNA interference markedly inhibited proliferation, colony formation, and migration in TE-1 and KYSE30 cells. CMap screening identified the endothelin-PDE5-cGMP axis as a potential therapeutic target. CONCLUSION: NMB serves as a key driver of metastatic adaptation in ESCC, conferring a survival advantage to tumor cells during metastatic colonization through genomic evolution and immune remodeling, with metabolic adaptation as a downstream consequence of genomic alterations.

NMB↗

PubMed2004

Mechanisms of antigen receptor evolution.

The adaptive immune system, which utilizes RAG-mediated recombination to diversify immune receptors, arose in ancestors of the jawed vertebrates approximately 500 million years ago. Homologs of immunoglobulins (Igs), T cell antigen receptors (TCRs), major histocompatibility complex (MHC) I and II, and the recombination activating genes (RAGs) have been identified in all extant classes of jawed vertebrates; however, no definitive ortholog of any of these genes has been identified in jawless vertebrates or invertebrates. Although the identity of the "primoridal" receptor that likely was interrupted by the recombination mechanism in the common ancestor of jawed vertebrates may never be established, many different families of genes that exhibit predicted characteristics of such a receptor have been described both within and outside the jawed vertebrates. Various model systems point toward a range of immune receptor diversity, encompassing many different families of recognition molecules, including non-diversified and diversified Ig-type variable (V) regions, as well as diversified VJ domains, whose functions are integrated in an organism's response to pathogenic invasion. The transition from the primordial antigen receptor to the monomeric Ig-/TCR-like domain and subsequent antigen-specific heterodimer likely involved progressive refinement of unique intermolecular associations in parallel with the acquisition of combinatorial diversity and antigen-specific recognition through somatic modification of the V region. RAG-mediated recombination and associated junctional diversification of both Ig and TCR genes occurs in all jawed vertebrates. In the case of Igs, somatic variation is expanded further through class switching, gene conversion, and somatic hypermutation. Various approaches, including both genomic and protein functional analyses, currently are being applied in jawless vertebrates, protochordates and other invertebrate deuterostome model systems in order to examine both RAG-mediated and alternative forms of antigen receptor diversification. Such studies have uncovered previously unknown mechanisms of generating receptor diversity.

Animals↗

PubMed2004

Hamster contraception associated protein 1 (CAP1).

Based on cDNA and amino acid sequence, we demonstrate that hamster contraception associated protein 1 (CAP1) protein (an homolog of DJ-1 in mouse, CAP1/SP22/RS in rat and DJ-1/RS in human) is conserved during evolution. Through solubilization studies, it was demonstrated that hamster CAP1 has a peripheral membrane localization. SDS-PAGE analysis revealed that the migration pattern for hamster CAP1 compared to the other rodent counterparts, rat and mouse was different; indicating species-specific differences in the protein (possibly due to post-translational modifications). This protein also shows a ubiquitous presence in both somatic and germ tissues, and has been localized to the sperm tail. It was noticed that hamster CAP1 was lost from the mid piece of spermatozoa during capacitation. Interestingly, following in vitro treatment with ornidazole, CAP1 was lost from the spermatozoa and immunofluorescence studies showed that the major loss was from the mid piece of the spermatozoa. Another interesting feature highlighted about hamster CAP1 is its tendency to exist in two pI isoforms. Summarily, hamster CAP1 appears to exhibit species-specific differences compared to its rodent counterparts with respect to its unique peripheral localization, its size, two pI isoforms, and fate during capacitation, which may have implications in its functions.

Animals↗

PubMed2004

The effects of vasopressin on human facial responses related to social communication.

Arginine vasopressin (AVP) and arginine vasotocin (AVT) influence social behaviors in a number of species from diverse taxonomic groups, therefore suggesting a conservation of social functions for these homologous neuropeptides during vertebrate evolution. However, whether or not AVP has the ability to directly influence social behavior in humans has not yet been determined. Because influences of AVT/AVP on behaviors related to social communication, particularly in aggressive contexts, are among the most consistently observed across species from diverse vertebrate groups, the present study was designed to determine if AVP administration would influence cognitive, autonomic and/or somatic responses to species-specific social stimuli important for agonistic communication in humans. Specifically, we tested the effects of intranasal AVP administration on attention towards emotionally expressive facial expressions, as well as on heart rate (HR), skin conductance (SC) and corrugator supercilii electromyograms (corrugator EMG) in response to these social stimuli. AVP did not affect attention toward, nor autonomic arousal in response to, emotionally neutral, happy or angry facial expressions, but it did selectively enhance the corrugator EMG responses evoked by emotionally neutral facial expressions, making them similar in magnitude to responses evoked by angry facial expressions in control subjects. Because this muscle group is involved in agonistic communication, these results suggest that AVP may influence aggression in human males by biasing individuals to respond to emotionally ambiguous social stimuli as if they were threatening/aggressive.

Adolescent↗

PubMed1997

Light and electron microscope study of nerve cells in traumatic oedematous human cerebral cortex.

The cerebral cortex of eight patients with complicated head and brain traumatic injuries has been examined with light and transmission electron microscopes. The neuronal and neuroglial cell bodies and their processes have been examined to study the changes induced by the brain injury and the associated vasogenic and cytotoxic, moderate or severe, brain oedema. Light microscopy study showed oedematous and ischaemic neurons and neuroglial cells in both moderate and severe oedema, and breakdown of the blood-brain barrier with perivascular and parenchymatous haemorrhagic foci. Astrocytes and oligodendrocytes exhibited oedematous and reactive changes. At the electron microscope level oedematous changes were found in intraneuronal and glial somatic compartment. Myelinated axons showed clear and dark degenerative features. Beaded dendrites and clear and dense synaptic degeneration were also found. The extracellular space appeared distended, with the presence of clear and electron-dense haematogenous oedema fluid and fibrinous organization. Phagocytosis of degenerated myelinated axons and synaptic endings by neuroglial cells and non-nervous invading cells were observed. The clinical evolution time of traumatic brain injuries was considered in relation to nerve cell degenerative features.

Adolescent↗