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1.
Internist (Berl) ; 60(11): 1201-1208, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31511906

RESUMO

This article reports about a 73-year-old woman of Bosnian descent who presented with acute renal failure. A renal biopsy was diagnostic for a postinfect necrotizing and extracapillary proliferative glomerulonephritis. The patient reported a febrile infection fever 2 weeks previously. The diagnostics did not reveal any indications of an ongoing infection. The glomerulonephritis responded to treatment with systemic steroids. The patient was readmitted to hospital 6 weeeks later in a severely ill condition. A gastric biopsy revealed a Strongyloides stercoralis infestation. Due to the systemic steroid therapy the patient had developed a so-called hyperinfection syndrome and died despite treatment on the intensive care unit. This case illustrates the need for awareness of this rare parasitosis, particularly in patients from endemic areas. A likely causal relationship with the glomerulonephritis is discussed and an overview of the diagnostics, course of the disease and treatment of this parasitosis is given.


Assuntos
Injúria Renal Aguda/etiologia , Glomerulonefrite/tratamento farmacológico , Prednisolona/efeitos adversos , Esteroides/efeitos adversos , Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase/diagnóstico , Idoso , Animais , Antiparasitários/uso terapêutico , Evolução Fatal , Feminino , Glomerulonefrite/diagnóstico , Humanos , Ivermectina/uso terapêutico , Prednisolona/uso terapêutico , Esteroides/uso terapêutico , Estômago/microbiologia , Estômago/patologia , Estrongiloidíase/complicações , Estrongiloidíase/tratamento farmacológico
2.
Br J Dermatol ; 177(6): 1510-1518, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28580642

RESUMO

Calciphylaxis is associated with significant morbidity and mortality. Palliative care (PC) is a subspecialty that treats the pain and stress of serious illness. To assess whether the role of quality of life (QoL) indices, patient-reported outcome measures and PC have been studied in patients with calciphylaxis, we performed a systematic literature review. Several databases were searched from inception to October 2016 according to modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. We searched for papers on calciphylaxis that mentioned the symptoms and supportive needs of patients, QoL or outcome measures to report symptom severity, and the involvement of PC. Twelve papers met the inclusion criteria. Reported patient symptoms included pain, skin lesion resolution and pruritus, with the first being the most frequently reported. Four papers measured pain using a previously verified patient-reported outcome measure, including the Visual Analogue Scale. One paper used a verified QoL measure, the Dermatology Quality of Life Index. No tool was used consistently. Eight papers reported the use of hospice care or PC in the treatment of calciphylaxis. No outcome measure was used to prompt PC involvement. Overall, QoL indices, patient-reported outcome measures and PC are underreported in the treatment of calciphylaxis. PC may be a resource to assist in symptom management and adaptive coping strategies for patients from the onset of disease.


Assuntos
Calciofilaxia/terapia , Cuidados Paliativos/estatística & dados numéricos , Qualidade de Vida , Calciofilaxia/psicologia , Utilização de Instalações e Serviços , Humanos , Cuidados Paliativos/psicologia , Medidas de Resultados Relatados pelo Paciente , Projetos de Pesquisa
3.
Unfallchirurg ; 117(1): 75-9, 2014 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-23483253

RESUMO

Isolated avulsions involving the tendon of the biceps femoris muscle are rare injuries. Injury patterns are similar to those of posterolateral knee injuries mostly due to hyperextension and external rotation. Functional loss is common regarding painful limited flexion of the knee. In the case described in this article there was complete avulsion of the biceps femoris tendon but low levels of pain and functional loss despite the proximity to the attachment.


Assuntos
Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/terapia , Modalidades de Fisioterapia , Traumatismos dos Tendões/diagnóstico , Traumatismos dos Tendões/terapia , Tenotomia/métodos , Adulto , Terapia Combinada , Humanos , Masculino , Ruptura/diagnóstico , Ruptura/terapia , Resultado do Tratamento
4.
Unfallchirurg ; 117(2): 169-73, 2014 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-23703619

RESUMO

This is a case presentation of a 9-year-old boy who sustained a rare Salter-Harris type IV distal fibular fracture including an avulsion fracture of the anterior inferior tibiofibular ligament at the fibular attachment. Treatment consisted of open reduction and internal fixation by Kirschner wire and cerclage. Possible posttraumatic growth disturbances and the major implications are highlighted.


Assuntos
Fraturas do Tornozelo/diagnóstico por imagem , Fraturas do Tornozelo/cirurgia , Fíbula/lesões , Fíbula/cirurgia , Fixação Interna de Fraturas/métodos , Osteotomia/métodos , Criança , Terapia Combinada/métodos , Fíbula/diagnóstico por imagem , Humanos , Masculino , Radiografia , Resultado do Tratamento
5.
Biochimie ; 99: 189-94, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24333987

RESUMO

The widely expressed mammalian glucose transporter, GLUT1, can be acutely activated in L929 fibroblast cells by a variety of conditions, including glucose deprivation, or treatment with various respiration inhibitors. Known thiol reactive compounds including phenylarsine oxide and nitroxyl are the fastest acting stimulators of glucose uptake, implicating cysteine biochemistry as critical to the acute activation of GLUT1. In this study, we report that in L929 cells glucose uptake increases 6-fold as the pH of the uptake solution is increased from 6 to 9 with the half-maximal activation at pH 7.5; consistent with the pKa of cysteine residues. This pH effect is essentially blocked by the pretreatment of the cells with either iodoacetamide or cinnamaldehyde, compounds that form covalent adducts with reduced cysteine residues. In addition, the activation by alkaline pH is not additive at pH 8 with known thiol reactive activators such as phenylarsine oxide or hydroxylamine. Kinetic analysis in L929 cells at pH 7 and 8 indicate that alkaline conditions both increases the Vmax and decreases the Km of transport. This is consistent with the observation that pH activation is additive to methylene blue, which activates uptake by increasing the Vmax, as well as to berberine, which activates uptake by decreasing the Km. This suggests that cysteine biochemistry is utilized in both methylene blue and berberine activation of glucose uptake. In contrast a pH increase from 7 to 8 in HCLE cells does not further activate glucose uptake. HCLE cells have a 25-fold higher basal glucose uptake rate than L929 cells and the lack of a pH effect suggests that the cysteine biochemistry has already occurred in HCLE cells. The data are consistent with pH having a complex mechanism of action, but one likely mediated by cysteine biochemistry.


Assuntos
Fibroblastos/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Arsenicais/farmacologia , Berberina/farmacologia , Transporte Biológico , Linhagem Celular , Cistina/metabolismo , Desoxiglucose/metabolismo , Ativadores de Enzimas/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno/farmacologia , Camundongos , Substâncias Redutoras/farmacologia
6.
Neuropharmacology ; 54(2): 405-16, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18054053

RESUMO

Aripiprazole (OPC-14597) is an antipsychotic with a unique pharmacology as a dopamine D2 receptor partial agonist, which has been demonstrated to reduce symptoms of schizophrenia. To further profile this compound in preclinical models, we examined aripiprazole-induced activity changes as measured by pharmacological magnetic resonance imaging (MRI) and characterized the drug in several rodent models of motor behaviors and of psychosis. Continuous arterial spin labeling MRI measuring blood perfusion (as an indirect measure of activity) reveals that aripiprazole dose-dependently decreased brain activity in the entorhinal piriform cortex, perirhinal cortex, nucleus accumbens shell, and basolateral amygdala. While no deficits were observed in the rotarod test for motor coordination in the simpler (8 RPM) version, in the more challenging condition (16 RPM) doses of 10 and 30mg/kg i.p. produced deficits. Catalepsy was seen only at the highest dose tested (30mg/kg i.p.) and only at the 3 and 6h time points, not at the 1h time point. In pharmacological models of psychosis, 1-30mg/kg aripiprazole i.p. effectively reduced locomotor activity induced by dopamine agonists (amphetamine and apomorphine), NMDA antagonists (MK-801 and phencyclidine (PCP)), and a serotonin agonist (2,5-dimethoxy-4-iodoamphetamine (DOI)). However, aripiprazole reversed prepulse inhibition deficits induced by amphetamine, but not by any of the other agents tested. Aripiprazole alters brain activity in regions relevant to schizophrenia, and furthermore, has a pharmacological profile that differs for the two psychosis models tested and does not match the typical or atypical psychotics. Thus, D2 partial agonists may constitute a new group of antipsychotics.


Assuntos
Antipsicóticos/farmacologia , Encéfalo/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Piperazinas/farmacologia , Psicoses Induzidas por Substâncias/psicologia , Quinolonas/farmacologia , Animais , Apomorfina/farmacologia , Aripiprazol , Catalepsia/induzido quimicamente , Catalepsia/psicologia , Interpretação Estatística de Dados , Agonistas de Dopamina/farmacologia , Alucinógenos/farmacologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , N-Metilaspartato/antagonistas & inibidores , Equilíbrio Postural/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Reflexo de Sobressalto/efeitos dos fármacos , Agonistas do Receptor de Serotonina/farmacologia
7.
Curr Drug Targets ; 8(1): 117-35, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17266536

RESUMO

The advance of functional genomics revealed the superfamily of G-protein coupled receptors (GPCRs). Hundreds of GPCRs have been cloned but many of them are orphan GPCRs with unidentified ligands. The first identified orphan GPCR is the opioid receptor like orphan receptor, ORL1. It was cloned in 1994 during the identification of opioid receptor subtypes and was de-orphanized in 1995 by the discovery of its endogenous ligand, nociceptin or orphanin FQ (N/OFQ). This receptor was renamed as N/OFQ peptide (NOP) receptor. Several selective ligands acting at NOP receptors or other anti-N/OFQ agents have been reported. These include N/OFQ-derived peptides acting as agonists (cyclo[Cys(10),Cys(14)]N/OFQ, [Arg(14), Lys(15)]N/OFQ, [pX]Phe(4)N/OFQ(1-13)-NH(2), UFP-102, [(pF)Phe(4),Aib(7), Aib(11),Arg(14),Lys(15)]N/OFQ-NH(2)) or antagonists (Phe(1)psi(CH(2)-NH)Gly(2)]N/OFQ(1-13)-NH(2), [Nphe(1)]N/OFQ(1-13)-NH(2), UFP-101, [Nphe(1), (pF)Phe(4),Aib(7),Aib(11),Arg(14),Lys(15)]N/OFQ-NH(2)), hexapeptides, other peptide derivatives (peptide III-BTD, ZP-120, OS-461, OS-462, OS-500), non-peptide agonists (NNC 63-0532, Ro 64-6198, (+)-5a compound, W-212393, 3-(4-piperidinyl)indoles, 3-(4-piperidinyl) pyrrolo[2,3-b]pyridines) and antagonists (TRK-820, J-113397, JTC-801, octahydrobenzimidazol-2-ones, 2-(1,2,4-oxadiazol-5-yl)-1 H-indole, N-benzyl-D-prolines, SB-612111), biostable RNA Spiegelmers specific against N/OFQ, and a functional antagonist, nocistatin. Buprenorphine and naloxone benzoylhydrazone are two opioid receptor ligands showing high affinity for NOP receptors. NOP receptor agonists might be beneficial in the treatment of pain, anxiety, stress-induced anorexia, cough, neurogenic bladder, edema, drug dependence, and, less promising, in cerebral ischemia and epilepsy, while antagonists might be of help in the management of pain, depression, dementia and Parkinsonism. N/OFQ is also involved in cardiovascular, gastrointestinal and immune regulation. Altered plasma levels of N/OFQ have been reported in patients with various pain states, depression and liver diseases. This review summarizes the pharmacological characteristics of, and studies with, the available NOP receptor ligands and their possible clinical implications.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Receptores Opioides/metabolismo , Animais , Humanos , Antagonistas de Entorpecentes , Peptídeos Opioides/agonistas , Peptídeos Opioides/antagonistas & inibidores , Peptídeos Opioides/metabolismo , Receptores Opioides/agonistas , Receptor de Nociceptina , Nociceptina
8.
J Pept Res ; 63(3): 196-9, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15049830

RESUMO

The stereoselective synthesis of orthogonally protected 3-azido aspartic acid derivatives is described. The convenience of their application as 2,3-diaminosuccinic acid in peptide chemistry was demonstrated by the incorporation of the nonproteinogenic diamino diacid as a cystine-substitute into the core structure of somatostatin.


Assuntos
Diamino Aminoácidos/química , Ácido Aspártico/análogos & derivados , Azidas/química , Peptídeos Cíclicos/síntese química , Conformação Molecular , Estrutura Molecular , Peptídeos Cíclicos/química , Somatostatina/análogos & derivados , Somatostatina/síntese química , Estereoisomerismo
10.
Acta Crystallogr B ; 58(Pt 4): 721-7, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12149563

RESUMO

The charge density of a hexapeptide was determined from high-resolution CCD area-detector experiments at 100 K. Two datasets, one from a rotating anode and a second one from synchrotron radiation, were measured and the results are compared. The data are interpreted in terms of the 'rigid pseudoatom' model. The topology of the experimental density is analyzed and compared with the topology of the constituting amino acids, and shows good agreement. All critical points of the electron density at the covalent and hydrogen bonds, as well as those of the Laplacian, were located. With respect to the transferability of electronic and bond topological properties the six peptide bonds were compared with values given in the literature.


Assuntos
Oligopeptídeos/química , Modelos Moleculares , Conformação Proteica , Reprodutibilidade dos Testes
12.
Biol Chem ; 382(8): 1197-205, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11592401

RESUMO

Urokinase-type plasminogen activator (uPA) represents a central molecule in pericellular proteolysis and is implicated in a variety of physiological and pathophysiological processes such as tissue remodelling, wound healing, tumor invasion, and metastasis. uPA binds with high affinity to a specific cell surface receptor, uPAR (CD87), via a well defined sequence within the N-terminal region of uPA (uPA19-31). This interaction directs the proteolytic activity of uPA to the cell surface which represents an important step in tumor cell proliferation, invasion, and metastasis. Due to its fundamental role in these processes, the uPA/uPAR-system has emerged as a novel target for tumor therapy. Previously, we have identified a synthetic, cyclic, uPA-derived peptide, cyclo19,31uPA19-31, as a lead structure for the development of low molecular weight uPA-analogues, capable of blocking uPA/uPAR-interaction [Burgle et al., Biol. Chem. 378 (1997), 231-237]. We now searched for peptide variants of cyclo19,31uPA19-31 with elevated affinities for uPAR binding. Among other tasks, we performed a systematic D-amino acid scan of uPA19-31, in which each of the 13 L-amino acids was individually substituted by the corresponding D-amino acid. This led to the identification of cyclo19,31[D-Cys19]-uPA19-31 as a potent inhibitor of uPA/uPAR-interaction, displaying only a 20 to 40-fold lower binding capacity as compared to the naturally occurring uPAR-ligands uPA and its amino-terminal fragment. Cyclo19,31[D-Cys19]-uPA19-31 not only blocks binding of uPA to uPAR but is also capable of efficiently displacing uPAR-bound uPA from the cell surface and to inhibit uPA-mediated, tumor cell-associated plasminogen activation and fibrin degradation. Thus, cyclo19,31[D-Cys19]-uPA19-31 represents a promising therapeutic agent to significantly affect the tumor-associated uPA/uPAR-system.


Assuntos
Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/farmacologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/farmacologia , Receptores de Superfície Celular/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Ativador de Plasminogênio Tipo Uroquinase/síntese química , Ativador de Plasminogênio Tipo Uroquinase/farmacologia , Substituição de Aminoácidos , Ligação Competitiva , Membrana Celular/metabolismo , Células Cultivadas , Fibrina/metabolismo , Humanos , Concentração Inibidora 50 , Fragmentos de Peptídeos/metabolismo , Peptídeos Cíclicos/metabolismo , Plasminogênio/metabolismo , Receptores de Superfície Celular/efeitos dos fármacos , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Relação Estrutura-Atividade , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
13.
Hemoglobin ; 25(2): 183-93, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11480780

RESUMO

Building on the pioneering efforts of Professor Huisman, several different databases of hemoglobin variants have been developed, each with progressively increased capacity for sophisticated queries and prompt updating. These resources are reviewed in the context of a larger plan for providing related resources on hemoglobins, benign and pathological variation in these proteins and the genes that encode them, and the regulation of the globin genes.


Assuntos
Bases de Dados de Ácidos Nucleicos , Hemoglobinas/genética , Expressão Gênica , Variação Genética , Humanos , Internet , Alinhamento de Sequência
14.
J Pept Sci ; 7(5): 250-61, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11428546

RESUMO

A new synthesis of orthogonally protected diaminoglutaric acid containing peptides using the Ugi four component condensation is presented. To demonstrate that this method is useful to replace cystine by diaminoglutaric acid in biologically interesting peptides, we built up two cyclic somatostatin analogues deriving from Sandostatin and from TT-232. A photolytically cleavable amine derivative of the nitroveratryl type is used for the Ugi four component condensation. Because of a racemic build up of the new stereocentre of the diaminoglutaric acid, and racemization of the isonitrile component, four diastereomeric peptides resulted that were separated by HPLC. The stereochemistry of the cyclopeptides could be easily and unambiguously assigned by chiral gas chromatography and a reference sample of enantiomerically pure (2S,4S)-diaminoglutaric acid.


Assuntos
Glutamatos/química , Peptídeos Cíclicos/síntese química , Antineoplásicos/química , Cromatografia Líquida de Alta Pressão , Cistina/química , Hormônios/química , Espectroscopia de Ressonância Magnética , Modelos Químicos , Octreotida/química , Peptídeos/síntese química , Peptídeos/química , Peptídeos Cíclicos/química , Somatostatina/análogos & derivados , Somatostatina/síntese química
15.
Eur J Med Chem ; 36(2): 165-78, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11311747

RESUMO

RO-04-6790 (6a) has been identified in a random screen for 5-HT(6) receptor antagonists. In a medicinal chemistry optimisation program a series of analogs comprising N-heteroaryl- and N-arylbenzenesulfonamides have been synthesised and investigated for their binding affinity. Compounds with a logD profile indicative of brain penetration have been subjected to in vivo testing for reversal of a scopolamine-induced retention deficit in a passive avoidance paradigm.


Assuntos
Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Antagonistas da Serotonina/farmacologia , Animais , Ligação Competitiva , Disponibilidade Biológica , Humanos , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Ligação Proteica , Pirimidinas , Ratos , Escopolamina , Antagonistas da Serotonina/farmacocinética , Sulfanilamida , Sulfanilamidas/síntese química , Sulfanilamidas/farmacocinética , Sulfanilamidas/farmacologia
16.
Nucleic Acids Res ; 29(6): 1352-65, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11239002

RESUMO

Chromosome 7q22 has been the focus of many cytogenetic and molecular studies aimed at delineating regions commonly deleted in myeloid leukemias and myelodysplastic syndromes. We have compared a gene-dense, GC-rich sub-region of 7q22 with the orthologous region on mouse chromosome 5. A physical map of 640 kb of genomic DNA from mouse chromosome 5 was derived from a series of overlapping bacterial artificial chromosomes. A 296 kb segment from the physical map, spanning ACHE: to Tfr2, was compared with 267 kb of human sequence. We identified a conserved linkage of 12 genes including an open reading frame flanked by ACHE: and Asr2, a novel cation-chloride cotransporter interacting protein Cip1, Ephb4, Zan and Perq1. While some of these genes have been previously described, in each case we present new data derived from our comparative sequence analysis. Adjacent unfinished sequence data from the mouse contains an orthologous block of 10 additional genes including three novel cDNA sequences that we subsequently mapped to human 7q22. Methods for displaying comparative genomic information, including unfinished sequence data, are becoming increasingly important. We supplement our printed comparative analysis with a new, Web-based program called Laj (local alignments with java). Laj provides interactive access to archived pairwise sequence alignments via the WWW. It displays synchronized views of a dot-plot, a percent identity plot, a nucleotide-level local alignment and a variety of relevant annotations. Our mouse-human comparison can be viewed at http://web.uvic.ca/~bioweb/laj.html. Laj is available at http://bio.cse.psu.edu/, along with online documentation and additional examples of annotated genomic regions.


Assuntos
Acetilcolinesterase/genética , Cromossomos Humanos Par 7/genética , Cromossomos/genética , Receptores da Transferrina/genética , Animais , Sequência de Bases , DNA/química , DNA/genética , Humanos , Internet , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Fases de Leitura Aberta , Mapeamento Físico do Cromossomo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Repetições de Trinucleotídeos , Células Tumorais Cultivadas
17.
J Virol ; 74(21): 10245-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11024157

RESUMO

The pathogenesis of scrapie, and of neurodegenerative diseases in general, is still insufficiently understood and is therefore being intensely researched. There is abundant evidence that the activation of glial cells precedes neurodegeneration and may thus play an important role in disease development and progression. The identification of genes with altered expression patterns in the diseased brain may provide insight on the molecular level into the process which ultimately leads to neuronal loss. Differentially expressed genes in scrapie-infected brain tissue were enriched by the suppression subtractive hybridization technique, molecularly cloned, and further characterized. Northern blotting and nucleotide sequencing confirmed the identities of 19 upregulated genes, 11 of which were unknown to be affected by scrapie. A considerable number of these 19 genes, namely those encoding interferon-inducible protein 10 (IP-10), 2',5'-oligo(A) synthetase, Mx protein, IIGP protein, major histocompatibility complex classes I and II, complement, and beta(2)-microglobulin, were inducible by interferons (IFNs), suggesting that an IFN response is a possible mechanism of gene activation in scrapie. Among the newly found genes, that coding for 2',5'-oligo(A) synthetase is of special interest because it could contribute to the apoptotic loss of neuronal cells via RNase L activation. In addition, upregulation of the chemokine IP-10 and B-lymphocyte chemoattractant mRNAs was seen at relatively early stages of the disease and was sustained throughout disease development.


Assuntos
Encéfalo/metabolismo , Regulação da Expressão Gênica , Scrapie/genética , Animais , Northern Blotting , Encéfalo/patologia , Clonagem Molecular , Cricetinae , DNA Complementar , Camundongos , Camundongos Endogâmicos BALB C , Hibridização de Ácido Nucleico/métodos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Scrapie/metabolismo , Scrapie/patologia , Ativação Transcricional , Regulação para Cima
18.
Nucleic Acids Res ; 28(18): 3486-96, 2000 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10982867

RESUMO

With the increase in the flow of sequence data, both in contigs and whole genomes, visual aids for comparison and analysis studies are becoming imperative. We describe three web-based tools for visualizing alignments of bacterial genomes. The first, called Enteric, produces a graphical, hypertext view of pairwise alignments between a reference genome and sequences from each of several related organisms, covering 20 kb around a user-specified position. Insertions, deletions and rearrangements relative to the reference genome are color-coded, which reveals many intriguing differences among genomes. The second, Menteric, computes and displays nucleotide-level multiple alignments of the same sequences, together with annotations of ORFs and regulatory sites, in a 1 kb region surrounding a given address. The third, a Java-based viewer called Maj, combines some features of the previous tools, and adds a zoom-in mechanism. We compare the Escherichia coli K-12 genome with the partially sequenced genomes of Klebsiella pneumoniae, Yersinia pestis, Vibrio cholerae, and the Salmonella enterica serovars Typhimurium, Typhi and Paratyphi A. Examination of the pairwise and multiple alignments in a region allows one to draw inferences about regulatory patterns and functional assignments. For example, these tools revealed that rffH, a gene involved in enterobacterial common antigen (ECA) biosynthesis, is partly deleted in one of the genomes. We used PCR to show that this deletion occurs sporadically in some strains of some serovars of S.enterica subspecies I but not in any strains tested from six other subspecies. The resulting cell surface diversity may be associated with selection by the host immune response.


Assuntos
Genoma Bacteriano , Internet , Alinhamento de Sequência/métodos , Software , DNA Bacteriano , Deleção de Genes , Nucleotidiltransferases/genética
19.
Genome Res ; 10(4): 577-86, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10779500

RESUMO

PipMaker (http://bio.cse.psu.edu) is a World-Wide Web site for comparing two long DNA sequences to identify conserved segments and for producing informative, high-resolution displays of the resulting alignments. One display is a percent identity plot (pip), which shows both the position in one sequence and the degree of similarity for each aligning segment between the two sequences in a compact and easily understandable form. Positions along the horizontal axis can be labeled with features such as exons of genes and repetitive elements, and colors can be used to clarify and enhance the display. The web site also provides a plot of the locations of those segments in both species (similar to a dot plot). PipMaker is appropriate for comparing genomic sequences from any two related species, although the types of information that can be inferred (e.g., protein-coding regions and cis-regulatory elements) depend on the level of conservation and the time and divergence rate since the separation of the species. Gene regulatory elements are often detectable as similar, noncoding sequences in species that diverged as much as 100-300 million years ago, such as humans and mice, Caenorhabditis elegans and C. briggsae, or Escherichia coli and Salmonella spp. PipMaker supports analysis of unfinished or "working draft" sequences by permitting one of the two sequences to be in unoriented and unordered contigs.


Assuntos
DNA/química , Internet/estatística & dados numéricos , Alinhamento de Sequência/estatística & dados numéricos , Software , Animais , Sequência de Bases/genética , Caenorhabditis elegans/genética , Biologia Computacional , DNA/genética , Escherichia coli/genética , Genes Bacterianos , Genes de Helmintos , Genes de Protozoários , Humanos , Internet/tendências , Camundongos , Dados de Sequência Molecular , Salmonella typhimurium/genética , Alinhamento de Sequência/métodos , Alinhamento de Sequência/tendências
20.
Nucleic Acids Res ; 27(19): 3899-910, 1999 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-10481030

RESUMO

Conserved segments in DNA or protein sequences are strong candidates for functional elements and thus appropriate methods for computing them need to be developed and compared. We describe five methods and computer programs for finding highly conserved blocks within previously computed multiple alignments, primarily for DNA sequences. Two of the methods are already in common use; these are based on good column agreement and high information content. Three additional methods find blocks with minimal evolutionary change, blocks that differ in at most k positions per row from a known center sequence and blocks that differ in at most k positions per row from a center sequence that is unknown a priori. The center sequence in the latter two methods is a way to model potential binding sites for known or unknown proteins in DNA sequences. The efficacy of each method was evaluated by analysis of three extensively analyzed regulatory regions in mammalian beta-globin gene clusters and the control region of bacterial arabinose operons. Although all five methods have quite different theoretical underpinnings, they produce rather similar results on these data sets when their parameters are adjusted to best approximate the experimental data. The optimal parameters for the method based on information content varied little for different regulatory regions of the beta-globin gene cluster and hence may be extrapolated to many other regulatory regions. The programs based on maximum allowed mismatches per row have simple parameters whose values can be chosen a priori and thus they may be more useful than the other methods when calibration against known functional sites is not available.


Assuntos
Sequência Conservada , Globinas/genética , Sequências Reguladoras de Ácido Nucleico , Alinhamento de Sequência/métodos , Software , Animais , Sequência de Bases , Calibragem , Bovinos , Eubacterium/genética , Estudos de Avaliação como Assunto , Evolução Molecular , Cabras , Humanos , Camundongos , Dados de Sequência Molecular , Homologia de Sequência do Ácido Nucleico
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