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1.
Arch Gynecol Obstet ; 306(2): 295-314, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625835

RESUMO

PURPOSE: Radical hysterectomy and pelvic lymphadenectomy is the standard treatment for early cervical cancer. Studies have shown superior oncological outcome for open versus minimal invasive surgery, but peri- and postoperative complication rates were shown vice versa. This meta-analysis evaluates the peri- and postoperative morbidities and complications of robotic and laparoscopic radical hysterectomy compared to open surgery. METHODS: Embase and Ovid-Medline databases were systematically searched in June 2020 for studies comparing robotic, laparoscopic and open radical hysterectomy. There was no limitation in publication year. Inclusion criteria were set analogue to the LACC trial. Subgroup analyses were performed regarding the operative technique, the study design and the date of publication for the endpoints intra- and postoperative morbidity, estimated blood loss, hospital stay and operation time. RESULTS: 27 studies fulfilled the inclusion criteria. Five prospective, randomized-control trials were included. Meta-analysis showed no significant difference between robotic radical hysterectomy (RH) and laparoscopic hysterectomy (LH) concerning intra- and perioperative complications. Operation time was longer in both RH (mean difference 44.79 min [95% CI 38.16; 51.42]), and LH (mean difference 20.96 min; [95% CI - 1.30; 43.22]) than in open hysterectomy (AH) but did not lead to a rise of intra- and postoperative complications. Intraoperative morbidity was lower in LH than in AH (RR 0.90 [0.80; 1.02]) as well as in RH compared to AH (0.54 [0.33; 0.88]). Intraoperative morbidity showed no difference between LH and RH (RR 1.29 [0.23; 7.29]). Postoperative morbidity was not different in any approach. Estimated blood loss was lower in both LH (mean difference - 114.34 [- 122.97; - 105.71]) and RH (mean difference - 287.14 [- 392.99; - 181.28]) compared to AH, respectively. Duration of hospital stay was shorter for LH (mean difference - 3.06 [- 3.28; - 2.83]) and RH (mean difference - 3.77 [- 5.10; - 2.44]) compared to AH. CONCLUSION: Minimally invasive radical hysterectomy appears to be associated with reduced intraoperative morbidity and blood loss and improved reconvalescence after surgery. Besides oncological and surgical factors these results should be considered when counseling patients for radical hysterectomy and underscore the need for new randomized trials.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Neoplasias do Colo do Útero , Feminino , Humanos , Histerectomia/efeitos adversos , Histerectomia/métodos , Laparoscopia/métodos , Morbidade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/cirurgia , Estudos Prospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Neoplasias do Colo do Útero/cirurgia
2.
Arch Gynecol Obstet ; 304(3): 577-587, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34021804

RESUMO

PURPOSE: Radical hysterectomy with pelvic lymphadenectomy presents the standard treatment for early cervical cancer. Recently, studies have shown a superior oncological outcome for open versus minimal invasive surgery, however, the reasons remain to be speculated. This meta-analysis evaluates the outcomes of robotic and laparoscopic hysterectomy compared to open hysterectomy. Risk groups including the use of uterine manipulators or colpotomy were created. METHODS: Ovid-Medline and Embase databases were systematically searched in June 2020. No limitation in date of publication or country was made. Subgroup analyses were performed regarding the surgical approach and the endpoints OS and DFS. RESULTS: 30 studies fulfilled the inclusion criteria. Five prospective, randomized-control trials were included. Patients were analyzed concerning the surgical approach [open surgery (AH), laparoscopic surgery (LH), robotic surgery (RH)]. Additionally, three subgroups were created from the LH group: the LH high-risk group (manipulator), intermediate-risk group (no manipulator, intracorporal colpotomy) and LH low-risk group (no manipulator, vaginal colpotomy). Regarding OS, the meta-analysis showed inferiority of LH in total over AH (0.97 [0.96; 0.98]). The OS was significantly higher in LH low risk (0.96 [0.94; 0.98) compared to LH intermediate risk (0.93 [0.91; 0.94]). OS rates were comparable in AH and LH Low-risk group. DFS was higher in the AH group compared to the LH group in general (0.92 [95%-CI 0.88; 0.95] vs. 0.87 [0.82; 0.91]), whereas the application of protective measures (no uterine manipulator in combination with vaginal colpotomy) was associated with increased DFS in laparoscopy (0.91 [0.91; 0.95]). CONCLUSION: DFS and OS in laparoscopy appear to be depending on surgical technique. Protective operating techniques in laparoscopy result in improved minimal invasive survival.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Colpotomia/métodos , Histerectomia/métodos , Laparoscopia/métodos , Neoplasias do Colo do Útero/cirurgia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Colpotomia/instrumentação , Detecção Precoce de Câncer , Feminino , Humanos , Histerectomia/efeitos adversos , Procedimentos Cirúrgicos Minimamente Invasivos , Gravidez , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia
3.
Am J Nephrol ; 32(4): 340-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20733289

RESUMO

BACKGROUND/AIMS: In Argentina, hemolytic uremic syndrome (HUS) constitutes the most frequent cause of acute renal failure in children. The aim of our study was to analyze the early tubular response under the effect of Shiga toxin type 2 (Stx2) in a rat experimental model of HUS. METHODS: Adult male Sprague-Dawley rats were injected intraperitoneally with culture supernatant from recombinant Escherichia coli expressing Stx2. Functional, histological, immunohistochemical and Western blot studies were performed at 48 h postinoculation. RESULTS: Renal tubules showed the loss of the epithelial markers E-cadherin and ß-catenin, and an increase in transforming growth factor-ß1 expression. We detected the expression of α-smooth muscle actin in the interstitium and fibrosis in the periglomerular areas. CONCLUSION: Our results indicate that the early tubular response to the effects of Stx2 is related to an immunophenotype change of tubular cells and the presence of mild fibrosis in the interstitium.


Assuntos
Síndrome Hemolítico-Urêmica/patologia , Síndrome Hemolítico-Urêmica/fisiopatologia , Túbulos Renais/patologia , Actinas/análise , Animais , Caderinas/análise , Células Epiteliais/química , Células Epiteliais/efeitos dos fármacos , Imuno-Histoquímica , Túbulos Renais/química , Masculino , Modelos Animais , Ratos , Ratos Sprague-Dawley , Toxina Shiga II , Fator de Crescimento Transformador beta1/análise , beta Catenina/análise
4.
Cell Death Differ ; 11(7): 760-70, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15017383

RESUMO

Potassium withdrawal is commonly used to induce caspase-mediated apoptosis in cerebellar granule neurons in vitro. However, the underlying and cell death-initiating mechanisms are unknown. We firstly investigated potassium efflux through the outward delayed rectifier K+ current (Ik) as a potential mediator. However, tetraethylammoniumchloride, an inhibitor of Ik, was ineffective to block apoptosis after potassium withdrawal. Since potassium withdrawal reduced intracellular pH (pHi) from 7.4 to 7.2, we secondly investigated the effects of intracellular acidosis. To study intracellular acidosis in cerebellar granule neurons, we inhibited the Na+/H+ exchanger (NHE) with 4-isopropyl-3-methylsulfonylbenzoyl-guanidine methanesulfonate (HOE 642) and 5-(N-ethyl-N-isopropyl)-amiloride. Both inhibitors concentration-dependently induced cell death and potentiated cell death after potassium withdrawal. Although inhibition of the NHE induced cell death with morphological criteria of apoptosis in light and electron microscopy including chromatin condensation, positive TUNEL staining and cell shrinkage, no internucleosomal DNA cleavage or activation of caspases was detected. In contrast to potassium withdrawal-induced apoptosis, cell death induced by intracellular acidification was not prevented by insulin-like growth factor-1, cyclo-adenosine-monophosphate, caspase inhibitors and transfection with an adenovirus expressing Bcl-XL. However, cycloheximide protected cerebellar granule neurons from death induced by potassium withdrawal as well as from death after treatment with HOE 642. Therefore, the molecular mechanisms leading to cell death after acidification appear to be different from the mechanisms after potassium withdrawal and resemble the biochemical but not the morphological characteristics of paraptosis.


Assuntos
Acidose/etiologia , Amilorida/análogos & derivados , Apoptose/efeitos dos fármacos , Caspases/fisiologia , Cerebelo/citologia , Neurônios/fisiologia , Trocadores de Sódio-Hidrogênio/antagonistas & inibidores , Acidose/metabolismo , Adenoviridae/genética , Amilorida/farmacologia , Animais , Sobrevivência Celular , Células Cultivadas , Cicloeximida/farmacologia , Relação Dose-Resposta a Droga , Guanidinas/farmacologia , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Potássio/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Ratos Sprague-Dawley , Trocadores de Sódio-Hidrogênio/efeitos dos fármacos , Sulfonas/farmacologia
5.
Mol Cell Neurosci ; 17(4): 717-31, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11312607

RESUMO

Cerebellar granule neurons (CGN) cultured in the presence of serum and depolarizing potassium concentrations undergo apoptosis when switched to serum-free medium containing physiological potassium concentrations. Here we show that processing of the key protease, caspase-3, depends on the activation of caspase-9, but not of caspase-8. Selective peptide inhibitors of caspase-9 block processing of caspase-3 and caspase-8 and inhibit apoptosis, whereas a selective inhibitor of caspase-8 blocks neither processing of caspase-3 nor cell death. The data obtained with peptide inhibitors were confirmed by adenovirally mediated ectopic expression of the cytokine response modifier A (crmA), the baculovirus protein p35, and the X chromosome-linked inhibitor of apoptosis (XIAP). Further, caspase-8-activating death receptors do not mediate apoptosis in CGN and potassium withdrawal-induced apoptosis evolves unaltered in gld or lpr mice, which harbor mutations in the CD95/CD95 ligand system. Thus, neuronal apoptosis triggered by potassium deprivation is death receptor-independent but involves the mitochondrial pathway of caspase activation.


Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Cerebelo/citologia , Neurônios/citologia , Neurônios/enzimologia , Potássio/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3 , Caspase 8 , Caspase 9 , Inibidores de Caspase , Sobrevivência Celular/fisiologia , Células Cultivadas , Cumarínicos/farmacologia , Inibidores Enzimáticos/farmacologia , Precursores Enzimáticos/antagonistas & inibidores , Precursores Enzimáticos/metabolismo , Regulação Viral da Expressão Gênica , Proteínas Inibidoras de Apoptose , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Oligopeptídeos/farmacologia , Proteínas/genética , Ratos , Ratos Sprague-Dawley , Serpinas/genética , Organismos Livres de Patógenos Específicos , Transgenes/fisiologia , Proteínas Virais/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X
6.
Mol Cell Neurosci ; 17(1): 78-96, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11161471

RESUMO

In order to achieve neuron-restricted expression of antiapoptotic proteins, cellular promoters were investigated for their expression profiles in the context of adenoviral vectors. Both the synapsin 1 gene and the tubulin alpha1 gene promoters were strictly neuron specific in cocultures of primary neurons with their essential feeder cells. The neuron-specific enolase gene promoter exhibited only weak activity in cultured hippocampal neurons and was not neuron specific in preparations of cerebellar granule cells. By attaining virtually 100% transduction efficiency we were able to generate "quasi-transgenic" primary neuron cultures using both differentiated and completely undifferentiated hippocampal neurons. In a functional assay, we used the synapsin promoter to evaluate the effect of Bcl-X(L) overexpression on potassium-withdrawal-induced apoptosis of cerebellar granule neurons. We found nearly complete inhibition of caspase-9 and -3 activation and apoptosis, indicating a major role for mitochondrial pathways in this paradigm of neuronal cell death. The excellent suitability of the synapsin promoter as a strong panneuronal promoter was further demonstrated by its restricted neuronal activity in various brain regions of adult rats in vivo.


Assuntos
Adenoviridae/genética , Vetores Genéticos/genética , Neurônios/metabolismo , Regiões Promotoras Genéticas/genética , Sinapsinas/genética , Animais , Apoptose/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Caspase 3 , Caspase 9 , Inibidores de Caspase , Caspases/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Cerebelo/citologia , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Técnicas de Cocultura , Citomegalovirus/genética , Expressão Gênica , Vetores Genéticos/metabolismo , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/embriologia , Hipocampo/metabolismo , Mitocôndrias/metabolismo , Neuroglia/citologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Potássio/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/farmacologia , Ratos , Ratos Sprague-Dawley , Transgenes , Tubulina (Proteína)/genética , Proteína bcl-X
7.
J Neurosci ; 20(24): 9126-34, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11124990

RESUMO

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces clinical, biochemical, and neuropathological changes reminiscent of those occurring in idiopathic Parkinson's disease (PD). Here we show that a peptide caspase inhibitor, N-benzyloxy-carbonyl-val-ala-asp-fluoromethyl ketone, or adenoviral gene transfer (AdV) of a protein caspase inhibitor, X-chromosome-linked inhibitor of apoptosis (XIAP), prevent cell death of dopaminergic substantia nigra pars compacta (SNpc) neurons induced by MPTP or its active metabolite 1-methyl-4-phenylpyridinium in vitro and in vivo. Because the MPTP-induced decrease in striatal concentrations of dopamine and its metabolites does not differ between AdV-XIAP- and control vector-treated mice, this protection is not associated with a preservation of nigrostriatal terminals. In contrast, the combination of adenoviral gene transfer of XIAP and of the glial cell line-derived neurotrophic factor to the striatum provides synergistic effects, rescuing dopaminergic SNpc neurons from cell death and maintaining their nigrostriatal terminals. These data suggest that a combination of a caspase inhibitor, which blocks death, and a neurotrophic factor, which promotes the specific function of the rescued neurons, may be a promising strategy for the treatment of PD.


Assuntos
Adenoviridae/genética , Terapia Genética/métodos , Fatores de Crescimento Neural , Proteínas do Tecido Nervoso/genética , Doença de Parkinson Secundária/terapia , Proteínas/genética , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Apoptose/efeitos dos fármacos , Inibidores de Caspase , Células Cultivadas , Dopamina/metabolismo , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Vetores Genéticos/farmacologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/farmacologia , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Terminações Pré-Sinápticas/efeitos dos fármacos , Terminações Pré-Sinápticas/metabolismo , Proteínas/metabolismo , Proteínas/farmacologia , Ratos , Ratos Sprague-Dawley , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Substância Negra/patologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X
8.
Virology ; 218(2): 396-9, 1996 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-8610467

RESUMO

The large surface protein (L) of the enveloped hepatitis B virus (HBV) is myristylated at glycine 2. To investigate whether this fatty acid moiety is required for HBV infectivity we made use of a point mutant in which the myristyl acceptor was mutated to a nonfunctional alanine. The mutant virus and a wild-type control were expressed in a human hepatoma cell line by transfection of genomic DNA constructs. Comparable amounts of virions were secreted by both strains as measured by the endogenous polymerase activity of immunoprecipitated virions. The presentation of an N-terminal epitope of L on the virion surface was not influenced by the mutation. To test the infectivity of this mutant virus primary human hepatocytes were incubated with the media of transfected cells. The covalently circular closed HBV DNA molecules generated after infection were discriminated from the open circular DNA genomes of inoculated virions by a sensitive PCR-based technique. The experiments demonstrated that the wild type was infectious but not the myristate negative mutant. This reflects the phenotype of an homologous duck hepatitis B virus mutant although the N-terminal L protein domains of this virus and of HBV show no primary sequence homology.


Assuntos
Vírus da Hepatite B/metabolismo , Ácidos Mirísticos/metabolismo , Proteínas do Envelope Viral/metabolismo , Sequência de Bases , Carcinoma Hepatocelular , Células Cultivadas , DNA Viral/análise , DNA Viral/química , DNA Viral/genética , Epitopos/análise , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/patogenicidade , Humanos , Fígado/citologia , Fígado/virologia , Dados de Sequência Molecular , Ácido Mirístico , Conformação de Ácido Nucleico , Mutação Puntual , Precursores de Proteínas/análise , Transfecção , Células Tumorais Cultivadas , Vírion/química
9.
Intervirology ; 39(1-2): 23-31, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8957666

RESUMO

The hepatitis B virus (HBV) envelope and the subviral lipoprotein particles contain three viral surface proteins (L, M, and S) which are expressed from one open reading frame by the usage of three start codons and a common stop codon. The largest surface protein L has some unusual properties. It adopts two different transmembrane topologies due to a posttranslational switch of the folding in approximately half of the L proteins. L molecules which expose their N-terminal preS1 domain on the viral particle surface are probably ligands for a putative virus receptor and determine the species specificity and liver tropism of this virus. L chains with internal preS1 domains are required in virion morphogenesis and mediate the contact to the nucleocapsid like a matrix protein. Overexpression of this form of the L protein is also responsible for the inhibition of viral particle release. This short review summarizes our knowledge on the biosynthesis and maturation of the HBV surface proteins and their functions in viral particle morphogenesis with special emphasis on the L protein.


Assuntos
Vírus da Hepatite B/fisiologia , Proteínas do Envelope Viral/fisiologia , Montagem de Vírus/fisiologia , Animais , Vetores Genéticos , Genoma , Antígenos de Superfície da Hepatite B , Vacinas contra Hepatite B , Humanos , Morfogênese , Nucleocapsídeo , Receptores Virais , Proteínas do Envelope Viral/metabolismo , Vírion/fisiologia
10.
J Virol ; 69(2): 1201-8, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7815496

RESUMO

The virus family Hepadnaviridae comprises two genera: orthohepadnaviruses isolated from humans (hepatitis B virus [HBV]) and rodents (e.g., woodchuck hepatitis virus [WHV]) and avihepadnaviruses isolated from birds (e.g., duck hepatitis B virus [DHBV]). They carry in their envelopes two (DHBV) or three (HBV and WHV) coterminal proteins referred to as small (S), middle (M), or large (L) surface protein. These proteins are also secreted from infected cells as subviral particles consisting of surface protein and lipid (e.g., 20-nm hepatitis B surface antigen for HBV). To investigate the assembly of these proteins, we asked whether surface proteins from different hepadnaviruses are able to mix phenotypically with each other. By coexpression and coimmunoprecipitation with species-specific antibodies, we could show the formation of mixed subviral particles and disulfide-linked heterodimers between the WHV S and HBV M proteins whereas the DHBV and HBV surface proteins did not coassemble. Complementation of HBV genomes defective in expressing the S or L protein and therefore incompetent to form virions was possible with the closely related WHV S protein or a WHV pre-S-HBV S chimera, respectively, but not with the less related DHBV S or L protein or with a DHBV L-HBV S chimera. The results suggest that the assembly of HBV subviral particles and virion envelopes requires relatively precise molecular interactions of their surface proteins, which are not conserved between the two hepadnavirus genera. This contrasts with the ability of, e.g., rhabdoviruses or retroviruses, to incorporate envelope proteins even from unrelated viruses.


Assuntos
Antígenos de Superfície da Hepatite B/metabolismo , Vírus da Hepatite B do Pato/metabolismo , Vírus da Hepatite B da Marmota/metabolismo , Vírus da Hepatite B/metabolismo , Proteínas do Envelope Viral/metabolismo , Sequência de Bases , Humanos , Dados de Sequência Molecular , Fenótipo , Precursores de Proteínas/metabolismo
12.
Ann Thorac Surg ; 48(6): 863-4, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2596925

RESUMO

In the face of recurrent heart transplant graft rejection refractory to all conventional immunotherapy, retransplantation is customary treatment. The case of a heart transplant recipient unsuitable for retransplantation whose recurrent rejection was successfully treated with postoperative total lymphoid irradiation is described.


Assuntos
Rejeição de Enxerto/efeitos da radiação , Transplante de Coração/imunologia , Irradiação Linfática , Adulto , Humanos , Imunossupressores/uso terapêutico , Masculino , Dosagem Radioterapêutica , Recidiva
13.
Proc Natl Acad Sci U S A ; 86(10): 3574-8, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2498873

RESUMO

The level of mRNA encoding the transferrin receptor (TfR) is regulated by iron, and this regulation is mediated by a portion of the 3' untranslated region (UTR) of the TfR transcript. This portion of 3' UTR of the human TfR mRNA contains five RNA elements that have structural similarity to the iron-responsive element (IRE) found as a single copy in the 5' UTR of the mRNA for ferritin, whose translation is regulated by iron. Moreover, five very similar elements are also contained in the 3' UTR of the chicken TfR mRNA. Cytosolic extracts of human cell lines are shown by a gel shift assay involving RNase T1 protection to contain an IRE-binding protein capable of specific interaction with the human TfR 3' UTR. When the protecting protein is removed, the protected RNA can be digested with RNase T1 to yield oligoribonucleotide fragments characteristic of two of the IREs contained in the TfR 3' UTR. As judged by cross-competition experiments, the same IRE-binding protein interacts with the ferritin IRE. The apparent affinity of RNA sequence elements for the IRE-binding protein is shown to depend upon the sequence of the RNA. A comprehensive secondary structure for the regulatory region of the TfR mRNA is proposed based on the experimentally demonstrated presence of at least two IRE-like structural elements.


Assuntos
Proteínas de Transporte/fisiologia , Ferro/fisiologia , RNA Mensageiro/metabolismo , Receptores da Transferrina/genética , Sequências Reguladoras de Ácido Nucleico , Sítios de Ligação , Ligação Competitiva , Citosol/fisiologia , Ferritinas/fisiologia , Humanos , Ligação de Hidrogênio , Conformação de Ácido Nucleico , Oligonucleotídeos/metabolismo , RNA Mensageiro/ultraestrutura , Proteínas de Ligação a RNA , Ribonuclease T1/farmacologia , Células Tumorais Cultivadas
14.
Nucleic Acids Res ; 17(10): 3763-71, 1989 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-2734102

RESUMO

Recombinant clones of the chicken transferrin receptor gene and cDNA have been isolated and sequenced. Two highly conserved regions have been identified in the 3' noncoding sequence of the human and chicken TR gene. The conserved regions include sequences that have been shown to be involved in the iron-dependent regulation of human TR mRNA stability. These sequences can be modeled as two different types of RNA secondary structures, one containing stem-loop structures that are similar to the iron-responsive elements found in ferritin mRNA and the other being a stable, duplex/stem-loop structure. Both forms show considerable similarity between chicken and human mRNA. The expression of TR is developmentally regulated during erythroid maturation, and immature erythroid cells express exceptionally high levels of TR mRNA.


Assuntos
DNA/genética , Genes , Receptores da Transferrina/genética , Animais , Sequência de Bases , Linhagem Celular , Galinhas , DNA/sangue , DNA de Neoplasias/genética , Eritrócitos/metabolismo , Humanos , Linfoma , Dados de Sequência Molecular , Conformação de Ácido Nucleico
15.
Ann Thorac Surg ; 42(4): 390-3, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3532979

RESUMO

The efficacy of oxygen radical scavengers in preservation of left ventricular (LV) function after prolonged hypothermic global ischemia was investigated in a model of orthotopic cardiac transplantation in sheep. Group 1 hearts (N = 8) received hypothermic crystalloid cardioplegic solution, and were harvested and stored at 4 degrees C in balanced electrolyte solution for six hours prior to transplantation. Group 2 (N = 9) received identical treatment with the addition of 30,000 units of superoxide dismutase to the cardioplegic solution and the administration of 60,000 units of superoxide dismutase coincident with reperfusion. All animals were weaned from cardiopulmonary bypass. Preischemic and postischemic LV function was determined using sonomicrometry and a micromanometer-tipped LV catheter. Coronary blood flow was determined using standard microsphere techniques, and platelet deposition was assayed with autologous platelets labeled with indium 111. Lipid peroxidation products were measured using thiobarbituric acid assay. LV performance was significantly better (p less than .05) in Group 2 hearts when assessed by the slope of the end-systolic pressure-volume relationship and the stroke work versus end-diastolic volume relationship. There was better preservation of endocardial blood flow in the group receiving superoxide dismutase compared with controls (p less than .05). Platelet deposition, as determined by the tissue to blood ratio of scintigraphic counts, was greater (p less than .05) in controls compared with the group receiving superoxide dismutase. In addition, thiobarbituric acid reactive species were significantly less (p less than .05) in Group 2 versus Group 1 hearts.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Transplante de Coração , Miocárdio , Preservação de Órgãos/métodos , Superóxido Dismutase/administração & dosagem , Animais , Circulação Coronária , Feminino , Radicais Livres , Masculino , Contração Miocárdica , Miocárdio/metabolismo , Oxirredução , Ovinos , Superóxido Dismutase/metabolismo
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