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1.
Sci Rep ; 14(1): 9113, 2024 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-38643179

RESUMO

While several effective therapies for critically ill patients with COVID-19 have been identified in large, well-conducted trials, the mechanisms underlying these therapies have not been investigated in depth. Our aim is to investigate the association between various immunosuppressive therapies (corticosteroids, tocilizumab and anakinra) and the change in endothelial host response over time in critically ill COVID-19 patients. We conducted a pre-specified multicenter post-hoc analysis in a Dutch cohort of COVID-19 patients admitted to the ICU between March 2020 and September 2021 due to hypoxemic respiratory failure. A panel of 18 immune response biomarkers in the complement, coagulation and endothelial function domains were measured using ELISA or Luminex. Biomarkers were measured on day 0-1, day 2-4 and day 6-8 after start of COVID-19 treatment. Patients were categorized into four treatment groups: no immunomodulatory treatment, corticosteroids, anakinra plus corticosteroids, or tocilizumab plus corticosteroids. The association between treatment group and the change in concentrations of biomarkers was estimated with linear mixed-effects models, using no immunomodulatory treatment as reference group. 109 patients with a median age of 62 years [IQR 54-70] of whom 72% (n = 78) was male, were included in this analysis. Both anakinra plus corticosteroids (n = 22) and tocilizumab plus corticosteroids (n = 38) were associated with an increase in angiopoietin-1 compared to no immune modulator (n = 23) (beta of 0.033 [0.002-0.064] and 0.041 [0.013-0.070] per day, respectively). These treatments, as well as corticosteroids alone (n = 26), were further associated with a decrease in the ratio of angiopoietin-2/angiopoietin-1 (beta of 0.071 [0.034-0.107], 0.060 [0.030-0.091] and 0.043 [0.001-0.085] per day, respectively). Anakinra plus corticosteroids and tocilizumab plus corticosteroids were associated with a decrease in concentrations of complement complex 5b-9 compared to no immunomodulatory treatment (0.038 [0.006-0.071] and 0.023 [0.000-0.047], respectively). Currently established treatments for critically ill COVID-19 patients are associated with a change in biomarkers of the angiopoietin and complement pathways, possibly indicating a role for stability of the endothelium. These results increase the understanding of the mechanisms of interventions and are possibly useful for stratification of patients with other inflammatory conditions which may potentially benefit from these treatments.


Assuntos
COVID-19 , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Angiopoietina-1 , SARS-CoV-2 , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Estado Terminal/terapia , Tratamento Farmacológico da COVID-19 , Corticosteroides/uso terapêutico , Terapia de Imunossupressão , Biomarcadores
2.
ESMO Open ; 8(3): 101541, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37178669

RESUMO

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, staging and treatment of patients with metastatic breast cancer (MBC) was published in 2021. A special, hybrid guidelines meeting was convened by ESMO and the Korean Society of Medical Oncology (KSMO) in collaboration with nine other Asian national oncology societies in May 2022 in order to adapt the ESMO 2021 guidelines to take into account the differences associated with the treatment of MBC in Asia. These guidelines represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with MBC representing the oncological societies of China (CSCO), India (ISMPO), Indonesia (ISHMO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO). The voting was based on the best available scientific evidence and was independent of drug access or practice restrictions in the different Asian countries. The latter were discussed when appropriate. The aim of these guidelines is to provide guidance for the harmonisation of the management of patients with MBC across the different regions of Asia, drawing from data provided by global and Asian trials whilst at the same time integrating the differences in genetics, demographics and scientific evidence, together with restricted access to certain therapeutic strategies.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Ásia , Índia , Sociedades Médicas , Oncologia
3.
J Eur Acad Dermatol Venereol ; 28(11): 1475-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24236446

RESUMO

BACKGROUND: Vitiligo is an acquired depigmentation disorder of melanocytes. Recently, some clinical reports have suggested that proton pump inhibitors (PPIs) may worsen vitiligo, but their effects on melanocytes have yet to be elucidated. OBJECTIVE: We investigated the effect of PPIs on melanogenesis in vivo and in vitro. METHODS: We examined the effect of PPIs on melanogenesis in B16 murine melanoma cells by measuring melanin content and tyrosinase (TYR) activity. TYR and tyrosinase-related protein-1 (TRP-1) were monitored by western blotting. Finally, a PPI was applied to zebrafish embryos to investigate its in vivo effect on pigmentation. RESULTS: In agreement with our clinical experience of worsened vitiligo after PPI treatment, PPIs decreased both melanin content and TYR activity. Western blotting showed that PPIs decreased TYR and TRP-1 protein levels. In the zebrafish test, PPIs inhibited body pigmentation in a dose-dependent manner. CONCLUSION: These results suggest that the functional inhibition of melanization by PPIs may induce or aggravate vitiligo lesions in genetically predisposed patients.


Assuntos
Úlcera Duodenal/tratamento farmacológico , Refluxo Laringofaríngeo/tratamento farmacológico , Melaninas/metabolismo , Inibidores da Bomba de Prótons/efeitos adversos , Inibidores da Bomba de Prótons/uso terapêutico , Vitiligo/diagnóstico , Vitiligo/etiologia , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Humanos , Técnicas In Vitro , Interferon Tipo I/metabolismo , Masculino , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/patologia , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Pessoa de Meia-Idade , Modelos Animais , Monofenol Mono-Oxigenase/metabolismo , Pigmentação , Proteínas da Gravidez/metabolismo , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Peixe-Zebra
4.
Med J Malaysia ; 68(5): 415-23, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24632872

RESUMO

No abstract available.

5.
Anaesth Intensive Care ; 40(5): 795-802, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22934861

RESUMO

In this randomised prospective study we aimed to evaluate whether preoperative anaesthetic education delivered to children on the day of surgery reduces anxiety behaviour during induction of anaesthesia. One hundred children, six to 15 years of age, undergoing general anaesthesia for ambulatory surgery were allocated at random to a preoperative education group (n=50) or a control group (n=50). The main outcomes were behaviour score, self-reporting of satisfaction score and identification of the stage when children felt most fearful. Data from all 100 participants were analysed. There was no difference in behaviour score at induction or satisfaction score between the groups. Eighteen percent in the intervention group reported no fear preoperatively vs 10% in the control group. Intravenous induction failed in nine out of 38 children in the intervention group (23.7%) compared to five out of 40 in the control group (12.5%). When intravenous induction failed, eight out of nine (89%) of the intervention group remained co-operative during gas induction compared to two out of five (40%) of the control group. Preoperative education delivered on the day of surgery did not reduce anxiety behaviour in children during intravenous induction of anaesthesia, but did reduce anxiety during subsequent inhalational induction.


Assuntos
Anestesia Intravenosa/psicologia , Ansiedade/prevenção & controle , Comportamento Infantil , Medo , Educação de Pacientes como Assunto , Criança , Método Duplo-Cego , Feminino , Humanos , Masculino , Período Pré-Operatório , Estudos Prospectivos
6.
Ann R Coll Surg Engl ; 93(7): 562; author reply 562, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22004652
7.
J Plast Reconstr Aesthet Surg ; 59(10): 1073-5, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16996431

RESUMO

Old and frail patients with advance breast malignancy require mastectomy which often results in large defects requiring soft tissue cover. We present three cases of large fasciocutaneous perforator based V-Y advancement flaps for reconstruction of large post-mastectomy wounds in older patients with large tumours. This technique reduces the morbidity of patients who have severe co-existing morbidity factor in addition to the advance breast disease.


Assuntos
Mamoplastia/métodos , Mastectomia , Retalhos Cirúrgicos , Idoso de 80 Anos ou mais , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/cirurgia , Feminino , Idoso Fragilizado , Humanos
9.
J Nutr ; 135(3): 513-8, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15735086

RESUMO

Yeast single-cell protein (SCP) is a high-nutrient feed substitute. This study evaluates the dual applications of a novel recombinant Pichia pastoris SMD1168H (SMD) yeast, expressing a tilapia vitellogenin protein (rVtg), as an SCP diet for Artemia and the first-feeding fish larvae. Instar II Artemia fed rVtg, rVtg precultured in 5% fish oil (rVtg-FO), Saccharomyces cerevisiae (SC), or native SMD had greater lipid contents (P < 0.05) than the freshly hatched. Lipid deposition in the Artemia fed rVtg or rVtg-FO was greater (P < 0.05) than in those fed SMD or SC. Diet-induced accumulation of low levels of docosahexaenoic acid [22:6(n-3)] was detected only in Artemia fed the rVtg-based diets. Tilapia (Oreochromis mossambicus) larvae were fed solely yeast diets singly or in combination (d 3-22), or a staggered regimen of yeast (d 3-12) followed by unenriched or yeast-enriched Artemia (d 13-22). The larvae fed rVtg for 22 d increased in length and weight (P < 0.05), whereas those fed SC or SMD suffered growth suppression and high mortality. Such adverse consequences were ameliorated when 50% of SC was substituted with rVtg. The larvae prefed rVtg followed by a dietary switch to Artemia preenriched for 48 h with rVtg or rVtg-FO were greatest in length, had the highest weight gain, and lived the longest. Besides delivering rVtg protein, essential fatty acids and amino acids, rVtg may have probiotic effects in enhancing larval survival. This study suggests the feasibility of using the rVtg yeast as an Artemia booster and an SCP first feed for larvae.


Assuntos
Proteínas Alimentares/farmacologia , Crescimento/efeitos dos fármacos , Pichia , Tilápia/crescimento & desenvolvimento , Vitelogeninas/farmacologia , Animais , Proteínas Fúngicas , Larva , Proteínas Recombinantes/farmacologia , Saccharomyces cerevisiae , Vitelogeninas/genética
10.
Biotechnol Bioeng ; 85(3): 330-9, 2004 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-14748089

RESUMO

Vitellogenin (Vtg) plays vital roles as precursor to the yolk proteins and as carrier for lipids, carbohydrates, phosphates, metal ions, vitamins, and hormones into the oocytes during the massive deposition of yolk nutrients for subsequent nourishment of the developing embryos. Reproductive success is highly sensitive to the nutritional quality of the broodstock diet, which greatly affects the egg and larval viability. We present a novel strategy for genetically engineering a Pichia pastoris yeast strain that constitutively produces recombinant Vtg (rVtg), for application as an enriched feed. The tilapia Oreochromis aureus Vtg (OaVtg) cDNA (5.3 kb) was cloned into a nonsecretory pGAPZA vector. Clones containing up to 31 copies of glyceraldehyde-3-phosphate dehydrogenase (GAP)-promoter-driven Vtg expression cassettes were isolated. These clones expressed a membrane-associated intracellular rVtg protein of 194 kDa, constituting up to 1.16% of total protein. To facilitate future purification of rVtg, we explored the possibility of secreting rVtg using the native Vtg secretion signal and the alpha-factor secretion signal of Saccharomyces cerevisiae. However, neither signal promoted the secretion of rVtg. The clones maximally expressed rVtg at 23 degrees C, reaching a peak at 22 h in shake flasks and 16 h in a fermentor. The clones exhibited a significant increase in essential amino acids and long-chain polyunsaturated fatty acids, which are important for its application as a high-quality nutrient feed.


Assuntos
Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Pichia/genética , Pichia/metabolismo , Engenharia de Proteínas/métodos , Vitelogeninas/biossíntese , Vitelogeninas/genética , Aminoácidos Essenciais/biossíntese , Animais , Clonagem Molecular/métodos , Ácidos Graxos Insaturados/biossíntese , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes/biossíntese , Tilápia/genética , Tilápia/metabolismo
11.
Singapore Med J ; 44(7): 340-3, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-14620724

RESUMO

INTRODUCTION: Pre-operative Chest X-ray (CXR) and electrocardiograms (ECG) are routinely ordered locally for patients above a certain age. This study examines the usefulness of such a practice and its clinical impact. METHODS: Prospective audit of 875 consecutive anaesthetic patients over a one-month period, assessing the proportion and impact of abnormal CXR or ECG findings. RESULTS: The proportion of patients with abnormal CXR or ECG increased with worsening ASA status. There was little impact of routine pre-operative CXR and ECG on anaesthetic management. Only 11/324 CXR and 13/375 ECG affected anaesthetic technique or choice of therapeutic procedure. CONCLUSION: Targeted investigations should be performed as indicated by clinical findings rather than on the basis of arbitrary age cut-offs.


Assuntos
Testes Diagnósticos de Rotina/estatística & dados numéricos , Eletrocardiografia/estatística & dados numéricos , Auditoria Médica , Radiografia Torácica/estatística & dados numéricos , Adulto , Humanos , Pessoa de Meia-Idade
12.
Gene ; 277(1-2): 175-86, 2001 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-11602355

RESUMO

Vitellogenins (Vtg) are egg-yolk precursor proteins crucial for reproductive success in oviparous animals. We have cloned the first complete cichlid Vtg cDNA from the tilapia fish, Oreochromis aureus. This cDNA has the largest phosvitin (PV) domain amongst piscine Vtgs, being comparable to those of lamprey, Xenopus, and chicken. Thus, the size of PV is independent of the evolutionary advancement of a species. The closer interspecific relationship between O. aureus Vtg1 and Fundulus VtgII than the intraspecific relationship between Fundulus VtgI and II isoforms suggests that teleost ancestors had at least two Vtg isoforms. Contrary to the results of previous phylogenetic inference using Vtgs which indicate that insect lineage is most diverged and nematodes are closer to vertebrate lineage, our results show that nematodes and hexapods form two monophyletic sister groups. Another arthropod taxon, represented by a malacostracan crustacean, Penaeus japonicus, appears to be more closely related to the vertebrates than the hexapods.


Assuntos
DNA Complementar/genética , Fosvitina/genética , Tilápia/genética , Vitelogeninas/genética , Sequência de Aminoácidos , Animais , Sequência Conservada/genética , DNA Complementar/química , Proteínas do Ovo/genética , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
13.
Can J Anaesth ; 48(6): 570-4, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11444452

RESUMO

PURPOSE: The study was aimed primarily at comparing the duration of analgesia produced by intrathecal fentanyl 25 microg with sufentanil 5 microg when added to bupivacaine 1.25 mg as the initial component of the combined spinal epidural (CSE) technique in early labour. METHODS: Forty healthy parturients were randomly assigned into two groups to receive either intrathecal sufentanil 5 microg plus bupivacaine 1.25 mg (Group S) or intrathecal fentanyl 25 microg plus bupivacaine 1.25 mg (Group F). Apart from the duration of analgesia, pain scores and side effects were also evaluated. RESULTS: There was no significant difference in the duration of analgesia (mean 109 +/- SD 49 min in Group F vs 118 +/- 54 min in Group S, P=0.9). Group F had a more rapid onset of analgesia (P <0.05) and a higher cephalad block (median T4 vs T7, P <0.05) in the first 30 min after the block. No difference in the side effects was detected. CONCLUSION: Fentanyl 25 microg is a good alternative to sufentanil 5 microg when added to bupivacaine 1.25 mg for early labour analgesia.


Assuntos
Analgesia Obstétrica , Analgésicos Opioides , Bupivacaína , Fentanila , Sufentanil , Adulto , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Bupivacaína/administração & dosagem , Bupivacaína/efeitos adversos , Feminino , Fentanila/administração & dosagem , Fentanila/efeitos adversos , Humanos , Injeções Espinhais , Medição da Dor , Gravidez , Sufentanil/administração & dosagem , Sufentanil/efeitos adversos
14.
Biochem Biophys Res Commun ; 269(2): 574-9, 2000 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-10708596

RESUMO

Effects of the aminoglycoside spectinomycin on the self-splicing of primary transcripts of the phage T4 thymidylate synthase gene (td) have been investigated. The kinetic analysis demonstrated that spectinomycin acts as a mixed noncompetitive inhibitor for the td intron RNA with a K(i) of 7.2 mM. Increasing the spectinomycin concentration raised the K(m) values with the corresponding decrease of V(max) and k(cat) values. The specificity of the splicing inhibition by spectinomycin is due to changes in both K(m) and k(cat). The splicing inhibition by spectinomycin is dependent on pH changes and Mg(2+) concentration, indicating electrostatic interactions with the intron RNA. It has been proposed that the key structural features in spectinomycin responsible for the inhibition of splicing may be the hydroxyl groups on the antibiotic.


Assuntos
Íntrons/efeitos dos fármacos , Splicing de RNA/efeitos dos fármacos , Espectinomicina/farmacologia , Guanosina Trifosfato/farmacologia , Concentração de Íons de Hidrogênio , Cinética , Magnésio/farmacologia
15.
Ann Acad Med Singap ; 28(4): 529-33, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10561767

RESUMO

Magnetic resonance (MR) imaging of brain metastases relies on the neovascularity of metastases and the associated breach of blood-brain barrier manifesting as enhancement on T1-weighted images. There are 2 main strategies to improve the detection of brain metastases. One may increase the dose of gadolinium and increase the signal of the lesion. Alternatively, one may also lower the signal of the background (by magnetisation transfer suppression), in which case the enhancing lesion is rendered more conspicuous without increasing the dose of gadolinium. We aim to compare the efficacy of single-dose conventional spin-echo T1 scans with magnetisation transfer (MT) suppression with triple-dose conventional spin-echo T1 scans in the detection of brain metastases in 18 patients undergoing imaging for brain metastases. An incremental dose technique was employed. After administration of a single dose of gadolinium, MT suppressed T1-weighted scans were obtained, followed by a conventional T1 scan. Two doses of gadolinium were subsequently given, achieving a cumulative triple-dose, and a conventional T1-weighted scan was then performed. We found single-dose MT suppressed and triple-dose scans performed equally well and detected 26 metastatic lesions. They detected 5 (5/26, 19%) more lesions than the conventional single-dose T1 scans. Five (5/21, 24%) questionable lesions on single-dose conventional scans were confidently diagnosed on the single-dose MT suppressed and the triple-dose conventional scan. We conclude that single-dose MT suppressed scans are a cost-effective technique of detecting brain metastases.


Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/secundário , Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Meios de Contraste/administração & dosagem , Relação Dose-Resposta a Droga , Estudos de Avaliação como Assunto , Feminino , Gadolínio DTPA/administração & dosagem , Humanos , Injeções Intravenosas , Imageamento por Ressonância Magnética/instrumentação , Masculino , Pessoa de Meia-Idade
16.
J Nucl Med ; 40(8): 30N-32N, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10450671
17.
Cell Mol Life Sci ; 55(4): 668-78, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10357235

RESUMO

Twelve cosmids containing sequences resembling genes encoding members of the 70-kDa heat-shock protein family, HSP70. have been isolated from Fugu rubripes. They can be broadly divided into three groups of overlapping cosmids. Restriction analysis and sequencing of one set of five cosmids have revealed five intronless Fugu HSP70 genes spanning 42 kb, arranged in a combined head-to-head, tail-to-tail and head-to-tail orientation. The levels of DNA and amino acid identity are very high with respect to one another, and are most similar to HSP70 sequences linked to the major histocompatibility complex (MHC) region in other species. Putative heat-shock consensus elements are identified. Non-HSP70 sequences with homology to known genes have been found physically linked to this Fugu HSP70 cluster: the Drosophila melanogaster SOL gene, the Drosophila melanogaster nemo gene, the Caenorhabditis elegans T17E9.1 gene and the sequence encoding the serine protease domain. The linkage relationships described here so far bear no resemblance to those of HSP70 in other organisms. Convergence of mammalian HSP70 and MHC class I and II loci probably occurred after fish had diverged.


Assuntos
Peixes/genética , Proteínas de Choque Térmico HSP70/genética , Família Multigênica , Sequência de Aminoácidos , Animais , Sequência de Bases , Cosmídeos , Impressões Digitais de DNA , DNA Complementar , Peixes/classificação , Homologia de Genes , Proteínas de Choque Térmico HSP70/classificação , Humanos , Dados de Sequência Molecular , Mapeamento por Restrição , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Fatores de Tempo
19.
Mol Cell Endocrinol ; 146(1-2): 103-20, 1998 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-10022768

RESUMO

The Oreochromis aureus vitellogenin, OaVtg, gene spans 9 kb and contains 34 exons. Its transcription start site is located 15 bp upstream of the translational start codon. Although the OaVtg promoter has a nonconsensus TATA, transient transfection assay showed that this promoter is capable of driving basal transcription. Two imperfect estrogen response elements: EREp (proximal) and EREd (distal) are located in the promoter at - 532 and - 1352, respectively. In competition gel mobility-shift assays, only EREp exhibited specific binding of the recombinant estrogen receptor protein, GST-C/D OaER. Another imperfect ERE (EREexon2) was detected within exon 2 of the OaVtg gene. This is a novel finding for a vitellogenin (Vtg) gene. EREexon2 similarly showed specific recognition of GST-C/D OaER. Both EREp and EREexon2 showed comparable binding affinities as consensus ERE. In transient transfections, the OaVtg promoter, EREp and EREd elicited significant increase in estrogen-dependent synthesis of CAT protein. Hence, we propose that the non-consensus OaVtg EREs contribute to the estrogen-dependent regulation of the OaVtg gene in vivo.


Assuntos
Estrogênios/farmacologia , Regiões Promotoras Genéticas , Tilápia/genética , Vitelogeninas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Cloranfenicol O-Acetiltransferase/genética , Escherichia coli/genética , Éxons , Feminino , Expressão Gênica , Íntrons , Dados de Sequência Molecular , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Proteínas Recombinantes/metabolismo , Sequências Reguladoras de Ácido Nucleico , Elementos de Resposta , Transcrição Gênica , Vitelogeninas/química
20.
DNA Seq ; 7(3-4): 141-51, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9254008

RESUMO

The genomic sequence and exon-intron organisation of the valyl-tRNA synthetase gene in the Japanese pufferfish, Fugu rubripes, have been determined. This single-copy Fugu gene spans 8.5 kb, about 2.5 times smaller than that in man (21 kb). It contains 29 exons, with the largest intron being 1008 bp. The predicted polypeptide consists of 1217 amino acids, with a molecular weight of 138 kD and an isoelectric point of 7.27. It shares 40% identity in the overlapping region with its homolog in bacteria, 47% with yeast, and 67% with man. The Fugu gene has an additional N-terminal sequence which shows strong similarity to elongation factory-1gamma, a feature it shares only with the human sequence, but not with any other lower eukaryote or prokaryote studied so far. This N-terminal segment is encoded in the first six exons, suggesting their capture by a translocation through introns. Indeed, the acquisition of extra domains to perform related functions in RNA splicing and translation of polypeptides has already been observed in other aminoacyl-tRNA synthetases. Two cDNA sequences of human valyl-tRNA synthetase have been published, with discrepancies between them. Aided by comparisons with the Fugu gene, three of these discrepancies have been resolved, involving the elucidation of the sequence and positions of two introns. This compact vertebrate genome has demonstrated its value as a tool for the analysis of genes at the genomic level.


Assuntos
Peixes Venenosos/genética , Valina-tRNA Ligase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Cosmídeos , Dosagem de Genes , Biblioteca Gênica , Genoma , Humanos , Íntrons , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Valina-tRNA Ligase/química , Valina-tRNA Ligase/metabolismo
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