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1.
Int J Mol Sci ; 21(6)2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32214045

RESUMO

Long non-coding RNAs (lncRNAs) are transcripts with poor coding capacity that may interact with proteins, DNA, or other RNAs to perform structural and regulatory functions. The lncRNA transcriptome changes significantly in most diseases, including cancer and viral infections. In this review, we summarize the functional implications of lncRNA-deregulation after infection with hepatitis C virus (HCV). HCV leads to chronic infection in many patients that may progress to liver cirrhosis and hepatocellular carcinoma (HCC). Most lncRNAs deregulated in infected cells that have been described function to potentiate or block the antiviral response and, therefore, they have a great impact on HCV viral replication. In addition, several lncRNAs upregulated by the infection contribute to viral release. Finally, many lncRNAs have been described as deregulated in HCV-related HCC that function to enhance cell survival, proliferation, and tumor progression by different mechanisms. Interestingly, some HCV-related HCC lncRNAs can be detected in bodily fluids, and there is great hope that they could be used as biomarkers to predict cancer initiation, progression, tumor burden, response to treatment, resistance to therapy, or tumor recurrence. Finally, there is high confidence that lncRNAs could also be used to improve the suboptimal long-term outcomes of current HCC treatment options.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/genética , Hepatite C/genética , Cirrose Hepática/genética , Neoplasias Hepáticas/genética , RNA Longo não Codificante/genética , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/virologia , Hepatite C/complicações , Hepatite C/metabolismo , Humanos , Cirrose Hepática/metabolismo , Cirrose Hepática/virologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/virologia , RNA Longo não Codificante/sangue , RNA Longo não Codificante/metabolismo
2.
Cir Pediatr ; 29(4): 162-165, 2016 Oct 10.
Artigo em Espanhol | MEDLINE | ID: mdl-28481069

RESUMO

AIM: To describe our experience as a tertiary center on the use of laparoscopic adrenal surgery in children. MATERIAL AND METHODS: A descriptive, retrospective study of patients with pathologic adrenal masses undergoing laparoscopic adrenal surgery, between 2012 and 2015. Epidemiological variables, surgical technique, complications and follow-up were studied. RESULTS: Nine patients were studied with a median age of 62 months (5-184). In 3 patients (33.33%) there was a prenatal diagnosis. Three patients had symptoms: hypertension and renal failure, precocious puberty, and an infected lymph node secondary to metastasis. In the rest, findings were incidental. In five patients the lesion was located on the right side and in four, on the left. The operation was performed laparoscopically. There was one conversion to open surgery because of poor visualization of the surgical field and no major intra- or postoperative complications were noted. The average hospital stay was 4 days (2-5). Postoperative pain was controlled during the first 24 hours with first step painkillers. Diagnoses were histologically confirmed: two ganglioneuroma, three neuroblastoma, bronchogenic cyst, pulmonary sequestration and adenoma. Mean follow-up was 22 months (1-53). CONCLUSIONS: In our series this surgical approach is associated with low morbidity and mortality, early recovery, shorter hospital stay and satisfactory results. We therefore propose laparoscopic adrenalectomy as a good alternative for approaching the pathologic adrenal masses in the pediatric population.


OBJETIVO: Describir nuestra experiencia como centro terciario en el uso de la laparoscopia para la exéresis de lesiones adrenales en la edad pediátrica. MATERIAL Y METODOS: Estudio descriptivo y retrospectivo de pacientes con lesiones en la glándula suprarrenal intervenidos de suprarrenalectomía laparoscópica entre los años 2012 y 2015. Se estudiaron variables epidemiológicas, técnica quirúrgica, complicaciones y seguimiento. RESULTADOS: Se estudiaron 9 pacientes con una mediana de 62 meses (5-184). Tres pacientes (33,33%) tenían un diagnóstico prenatal y tres pacientes debutaron con síntomas: hipertensión e insuficiencia renal, pubertad precoz y otro con un adenoflemón secundario a metástasis. En el resto, el hallazgo fue incidental. En cinco pacientes la lesión se situó en el lado derecho y en cuatro en el izquierdo. La intervención se realizó por vía laparoscópica. En un paciente se convirtió a cirugía abierta por mala visualización en el campo quirúrgico. No se produjeron complicaciones perioperatorias ni necesidad de trasfusión. La media de la estancia hospitalaria fue de 4 días (2-5). El dolor postoperatorio fue controlado durante las primeras 24 horas y con analgésicos de primer escalón. Los diagnósticos confirmados por histología fueron: seis neuroblastomas, dos ganglioneuromas y un adenoma. La media de seguimiento fue de 22 meses (1-53). CONCLUSIONES: En nuestra serie esta vía de abordaje está asociada a una baja morbimortalidad con una recuperación precoz, corta estancia hospitalaria y resultados satisfactorios. Por tanto, proponemos la adrenalectomía laparoscópica como una buena alternativa para el abordaje de las lesiones suprarrenales en la población pediátrica.


Assuntos
Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia/métodos , Laparoscopia , Criança , Humanos , Estudos Retrospectivos , Resultado do Tratamento
3.
Analyst ; 139(14): 3572-6, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-24867650

RESUMO

A miniaturised gas analyser is described and evaluated based on the use of a substrate-integrated hollow waveguide (iHWG) coupled to a microsized near-infrared spectrophotometer comprising a linear variable filter and an array of InGaAs detectors. This gas sensing system was applied to analyse surrogate samples of natural fuel gas containing methane, ethane, propane and butane, quantified by using multivariate regression models based on partial least square (PLS) algorithms and Savitzky-Golay 1(st) derivative data preprocessing. The external validation of the obtained models reveals root mean square errors of prediction of 0.37, 0.36, 0.67 and 0.37% (v/v), for methane, ethane, propane and butane, respectively. The developed sensing system provides particularly rapid response times upon composition changes of the gaseous sample (approximately 2 s) due the minute volume of the iHWG-based measurement cell. The sensing system developed in this study is fully portable with a hand-held sized analyser footprint, and thus ideally suited for field analysis. Last but not least, the obtained results corroborate the potential of NIR-iHWG analysers for monitoring the quality of natural gas and petrochemical gaseous products.


Assuntos
Gases/análise , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Calibragem , Desenho de Equipamento , Análise dos Mínimos Quadrados , Miniaturização
4.
Gene Ther ; 19(4): 411-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21850051

RESUMO

In liver cirrhosis, abnormal liver architecture impairs efficient transduction of hepatocytes with large viral vectors such as adenoviruses. Here we evaluated the ability of adeno-associated virus (AAV) vectors, small viral vectors, to transduce normal and cirrhotic rat livers. Using AAV serotype-1 (AAV1) encoding luciferase (AAV1Luc) we analyzed luciferase expression with a CCD camera. AAV1Luc was injected through the hepatic artery (intra-arterial (IA)), the portal vein (intra-portal (IP)), directly into the liver (intra-hepatic (IH)) or infused into the biliary tree (intra-biliar). We found that AAV1Luc allows long-term and constant luciferase expression in rat livers. Interestingly, IP administration leads to higher expression levels in healthy than in cirrhotic livers, whereas the opposite occurs when using IA injection. IH administration leads to similar transgene expression in cirrhotic and healthy rats, whereas intra-biliar infusion is the least effective route. After 70% partial hepatectomy, luciferase expression decreased in the regenerating liver, suggesting lack of efficient integration of AAV1 DNA into the host genome. AAV1Luc transduced mainly the liver but also the testes and spleen. Within the liver, transgene expression was found mainly in hepatocytes. Using a liver-specific promoter, transgene expression was detected in hepatocytes but not in other organs. Our results indicate that AAVs are convenient vectors for the treatment of liver cirrhosis.


Assuntos
Dependovirus/genética , Terapia Genética/métodos , Hepatócitos/metabolismo , Cirrose Hepática/terapia , Fígado/metabolismo , Transdução Genética , Animais , Vetores Genéticos , Artéria Hepática , Cirrose Hepática/genética , Regeneração Hepática/genética , Luciferases/genética , Luciferases/metabolismo , Masculino , Veia Porta , Ratos , Ratos Sprague-Dawley
5.
Nucleic Acids Res ; 38(13): e136, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20427423

RESUMO

RNA interference (RNAi) has been revolutionary for the specific inhibition of gene expression. However, the application of RNAi has been hampered by the fact that many siRNAs induce dose-dependent unwanted secondary effects. Therefore, new methods to increase inhibition of gene expression with low doses of inhibitors are required. We have tested the combination of RNAi and U1i (U1 small nuclear RNA--snRNA--interference). U1i is based on U1 inhibitors (U1in), U1 snRNA molecules modified to target a pre-mRNA and inhibit its gene expression by blocking nuclear polyadenylation. The combination of RNAi and U1i resulted in stronger inhibition of reporter or endogenous genes than that obtained using either of the techniques alone. The increased inhibition observed is stable over time and allows higher inhibition than the best obtained with either of the inhibitors alone even with decreased doses of the inhibitors. We believe that the combination of RNAi and U1i will be of interest when higher inhibition is required or when potent inhibitors are not available. Also, the combination of these techniques would allow functional inhibition with a decreased dose of inhibitors, avoiding toxicity due to dose-dependent unwanted effects.


Assuntos
Interferência de RNA , RNA Nuclear Pequeno/antagonistas & inibidores , Linhagem Celular , Regulação para Baixo , Genes Reporter , Células HeLa , Humanos , Luciferases/genética , Luciferases/metabolismo , RNA Interferente Pequeno/metabolismo , Receptor Notch1/genética , Receptor Notch1/metabolismo
6.
Radiologia (Engl Ed) ; 64(2): 145-155, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35504680

RESUMO

OBJECTIVE: Distal nerve degeneration refers to the process of disintegration of a neuron or neuronal circuit as a consequence of distal damage. The end result of multiple etiologies, this finding is becoming common due to the increasing number of imaging tests done. This paper aims to define the different types of distal nerve damage, review the anatomy and function of the most commonly affected tracts, and illustrate distal nerve damage through diagrams and representative cases from routine practice. CONCLUSION: Knowing the distant response that can be expected according to the topography of a neuronal lesion is crucial to avoid diagnostic errors. Axonal degeneration and transsynaptic degeneration can be both antegrade and retrograde. Studies of cerebral metabolism, perfusion sequences, and diffusion sequences are showing increasingly earlier changes related to the same process; radiologists need to be aware of these changes.


Assuntos
Neurônios , Doenças do Sistema Nervoso Periférico , Diagnóstico por Imagem , Humanos , Degeneração Neural/patologia , Neurônios/patologia
7.
Gene Ther ; 18(9): 929-35, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21472008

RESUMO

RNA interference (RNAi) has been successfully employed for specific inhibition of gene expression; however, safety and delivery of RNAi remain critical issues. We investigated the combinatorial use of RNAi and U1 interference (U1i). U1i is a gene-silencing technique that acts on the pre-mRNA by preventing polyadenylation. RNAi and U1i have distinct mechanisms of action in different cellular compartments and their combined effect allows usage of minimal doses, thereby avoiding toxicity while retaining high target inhibition. As a proof of concept, we investigated knockdown of the firefly luciferase reporter gene by combinatorial use of RNAi and U1i, and evaluated their inhibitory potential both in vitro and in vivo. Co-transfection of RNAi and U1i constructs showed additive reduction of luciferase expression up to 95% in vitro. We attained similar knockdown when RNAi and U1i constructs were hydrodynamically transfected into murine liver, demonstrating for the first time successful in vivo application of U1i. Moreover, we demonstrated long-term gene silencing by AAV-mediated transduction of murine muscle with RNAi/U1i constructs targeting firefly luciferase. In conclusion, these results provide a proof of principle for the combinatorial use of RNAi and U1i to enhance target gene knockdown in vivo.


Assuntos
Técnicas de Silenciamento de Genes , Luciferases/genética , Interferência de RNA , RNA Nuclear Pequeno , Animais , Dependovirus/genética , Fígado/metabolismo , Camundongos , Músculos/metabolismo
8.
J Cell Biol ; 130(5): 1117-25, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7657696

RESUMO

Lysin is a 16-kD acrosomal protein used by abalone spermatozoa to create a hole in the egg vitelline envelope (VE) by a nonenzymatic mechanism. The crystal structure of the lysin monomer is known at 1.9 A resolution. The surface of the molecule reveals two tracks of basic residues running the length of one surface of the molecule and a patch of solvent-exposed hydrophobic residues on the opposite surface. Here we report that lysin dimerizes via interaction of the hydrophobic patches of monomers. Triton X-100 dissociates the dimer. The crystal structure of the dimer is described at 2.75 A resolution. Fluorescence energy transfer experiments show that the dimer has an approximate KD of 1 microM and that monomers exchange rapidly between dimers. Addition of isolated egg VE dissociates dimers, implicating monomers as the active species in the dissolution reaction. This work represents the first step in the elucidation of the mechanism by which lysin enables abalone spermatozoa to create a hole in the egg envelope during fertilization.


Assuntos
Proteínas do Ovo/metabolismo , Moluscos/metabolismo , Mucoproteínas/farmacologia , Espermatozoides/metabolismo , Membrana Vitelina/metabolismo , Animais , Cristalização , Feminino , Fertilização/fisiologia , Corantes Fluorescentes , Masculino , Moluscos/química , Mucoproteínas/metabolismo , Mucoproteínas/ultraestrutura , Ligação Proteica/fisiologia , Membrana Vitelina/ultraestrutura
9.
J Cell Biol ; 39(2): 382-91, 1968 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-5692584

RESUMO

Glutaraldehyde has been used to fix mitochondria undergoing rapid volume changes associated with energized ion transport under oscillatory state conditions and valinomycin-induced potassium uptake. Fixation was found to prevent structural changes which normally occur during ion accumulation or loss. By correlating packed volume measurements with electron microscopy, it is shown that changes in volume associated with ion movements reflect changes in the inner membrane compartment and that this compartment can be related to the sucrose inaccessible space. The method can therefore be used to accurately determine volume changes that arise from ion translocation.


Assuntos
Transporte Biológico Ativo/fisiologia , Mitocôndrias Hepáticas/fisiologia , Potássio/metabolismo , Aldeídos , Animais , Antibacterianos/farmacologia , Luz , Membranas/fisiologia , Métodos , Microscopia Eletrônica , Mitocôndrias Hepáticas/efeitos dos fármacos , Osmose , Ratos
10.
Cir Pediatr ; 32(4): 195-200, 2019 Oct 01.
Artigo em Espanhol | MEDLINE | ID: mdl-31626405

RESUMO

OBJECTIVE: Retrospective and descriptive study of patients with diagnosis of Hirschsprung disease (HD) in whom transanal pull-through was performed in our center. MATERIAL AND METHODS: All patients with diagnosis of HD in whom transanal surgery was performed between 2006 and 2018 in our center were selected. In all cases laparoscopic biopsy was performed in the previous dilated area. Once intraoperatory biopsy revealed the presence of ganglionic cells, transanal De la Torre surgery was performed, until reaching the localization of the biopsied area. Circular automatic suture was performed in all cases. RESULTS: Surgery was performed in 21 patients (16 boys and 5 girls) with a median age of 12 months (5-62). No patient had enterocolitis. The median resection length was 14.5 cm (3-45) and no intraoperative complications happened. One patient (5%) developed a rectosigmoideal abscess, which was solved with antibiotic. One case (5%) needed another surgery due to umbilical trochar eventration. No patient had enterocolitis after the surgery. One patient (5%) had stenosis, solved by its section and other case (5%) had sleeve compression which was solved by laparoscopic section. After a median follow up of 97 months (12-159), one child (5%) developed encopresis, which is treated with periodic anal irrigations and other patient (5%) has chronic constipation, which require periodic enemas. The rest of the patients have no symptomatology. CONCLUSION: In conclusion, in our series of cases, transanal pull-through with circular automatic suture was a safe and useful technique. It has a low rate of operative and postoperative complications and provides good prospective results.


OBJETIVO: Estudio retrospectivo descriptivo de pacientes con enfermedad de Hirschsprung (EH) intervenidos en nuestro centro por vía transanal. MATERIAL Y METODOS: Se seleccionaron a los pacientes con diagnóstico de EH intervenidos por vía transanal con sutura automática circular en nuestro centro entre los años 2006 y 2018. Se realizó biopsia laparoscópica de la zona previa a la dilatación en todos los casos. Tras la confirmación de la presencia de células, se procedió al descenso transanal tipo De la Torre hasta alcanzar la zona de la biopsia. La anastomosis se realizó con sutura automática circular (CEEA 21 o 25 mm). RESULTADOS: Se intervinieron 21 pacientes, 16 niños y 5 niñas, con una mediana de edad de 12 meses (5-62). Ningún paciente presentó enterocolitis preoperatoria. La mediana de la longitud resecada fue de 14,5 cm (3-45), sin incidencias intraoperatorias. Un paciente (5%) presentó absceso rectosigmoideo postoperatorio, resuelto con antibióticos. Un caso (5%) necesitó de nueva cirugía por eventración del acceso umbilical. Un paciente (5%) presentó estenosis, resuelta mediante sección y otro (5%) compresión del manguito seromuscular, que fue tratada con sección laparoscópica. No hubo casos de enterocolitis postoperatoria. Tras una mediana de seguimiento de 97 meses (12-159), un niño presenta encopresis (5%) tratada mediante sistema de irrigaciones transanales periódicas y otro caso (5%) cursa con estreñimiento, en tratamiento con enemas periódicos. El resto se hallan asintomáticos. CONCLUSION: En definitiva, podemos afirmar que en nuestra serie el descenso transanal con sutura automática circular es una técnica segura y eficaz, que presenta una tasa baja de complicaciones intra y postoperatorias, con buenos resultados a largo plazo.


Assuntos
Doença de Hirschsprung/cirurgia , Técnicas de Sutura , Canal Anal , Pré-Escolar , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
11.
Mol Cell Biol ; 19(3): 2212-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10022908

RESUMO

In the course of a two-hybrid screen with the NS1 protein of influenza virus, a human clone capable of coding for a protein with high homology to the Staufen protein from Drosophila melanogaster (dmStaufen) was identified. With these sequences used as a probe, cDNAs were isolated from a lambda cDNA library. The encoded protein (hStaufen-like) contained four double-stranded RNA (dsRNA)-binding domains with 55% similarity and 38% identity to those of dmStaufen, including identity at all residues involved in RNA binding. A recombinant protein containing all dsRNA-binding domains was expressed in Escherichia coli as a His-tagged polypeptide. It showed dsRNA binding activity in vitro, with an apparent Kd of 10(-9) M. Using a specific antibody, we detected in human cells a major form of the hStaufen-like protein with an apparent molecular mass of 60 to 65 kDa. The intracellular localization of hStaufen-like protein was investigated by immunofluorescence using a series of markers for the cell compartments. Colocalization was observed with the rough endoplasmic reticulum but not with endosomes, cytoskeleton, or Golgi apparatus. Furthermore, sedimentation analyses indicated that hStaufen-like protein associates with polysomes. These results are discussed in relation to the possible functions of the protein.


Assuntos
Proteínas de Drosophila , Retículo Endoplasmático Rugoso/metabolismo , Polirribossomos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Sequência de Aminoácidos , Animais , Células COS , Linhagem Celular Transformada , Proteínas do Citoesqueleto , Drosophila melanogaster , Expressão Gênica , Células HeLa , Humanos , Dados de Sequência Molecular , Proteínas de Ligação a RNA/genética , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
12.
Mol Cell Biol ; 19(10): 6543-53, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10490594

RESUMO

Yeast strains lacking the yeast nuclear cap-binding complex (yCBC) are viable, although impaired in growth. We have taken advantage of this observation to carry out a genetic screen for components that show synthetic lethality (SL) with a cbp20-Delta cbp80-Delta double mutation. One set of SL interactions was due to mutations that were complemented by components of U1 small nuclear RNP (snRNP) and the yeast splicing commitment complex. These interactions confirm the role of yCBC in commitment complex formation. Physical interaction of yCBC with the commitment complex components Mud10p and Mud2p, which may directly mediate yCBC function, was demonstrated. Unexpectedly, we identified multiple SL mutations that were complemented by Cbf5p and Nop58p. These are components of the two major classes of yeast small nucleolar RNPs, which function in the maturation of rRNA precursors. Mutants lacking yCBC were found to be defective in rRNA processing. Analysis of the yCBC deletion phenotype suggests that this is likely to be due to a defect in the splicing of a subset of ribosomal protein mRNA precursors.


Assuntos
Proteínas Nucleares/metabolismo , Capuzes de RNA/metabolismo , Splicing de RNA , Proteínas de Ligação a RNA/metabolismo , Saccharomyces cerevisiae/genética , Deleção de Genes , Genes Letais , Teste de Complementação Genética , Proteínas Nucleares/genética , Ligação Proteica , Proteínas de Ligação ao Cap de RNA , Precursores de RNA/metabolismo , RNA Mensageiro/biossíntese , RNA Ribossômico/biossíntese , Proteínas de Ligação a RNA/genética
13.
Braz J Biol ; 66(4): 1037-43, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17299939

RESUMO

The lepidopterans Platynota rostrana (Walker) (Tortricidae) and Phidotricha erigens Raganot (Pyralidae) have been found frequently in citrus groves in São Paulo State in recent years. Since in Brazil, the fertility cycle of these two species is largely unknown, as are details of the damage wrought by them in crops, this research studied these aspects of the two species, which were kept under laboratory conditions (temperature 25 +/- 2 degrees C, 70 +/- 10% RH, 14 h photophase) and on an artificial diet. The duration of the biological cycle (egg-adult) for P. rostrana was 38.3 days and total viability was 44.0%; for P. erigens these values were 32.5 days and 63.6%, respectively. Both species showed five larval instars. Females of P. rostrana laid an average of 308 eggs, whereas those of P. erigens laid an average of 106 eggs. In both species, female pupae were heavier than males. Male and female longevity for both species was nearly 10 days. Based on the data obtained, the artificial diet produced better results in P. rostrana than in P. erigens. If these species, which have the potential to reach pest status in the citrus groves of São Paulo State, could be reared on an artificial diet, research on their control by alternative methods would be easier.


Assuntos
Citrus/parasitologia , Dieta , Estágios do Ciclo de Vida , Mariposas/crescimento & desenvolvimento , Animais , Feminino , Fertilidade/fisiologia , Larva/crescimento & desenvolvimento , Masculino , Mariposas/classificação
14.
Biochim Biophys Acta ; 413(1): 65-78, 1975 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-127620

RESUMO

1. The membrane perturbations induced by the interaction of the fluorescent probe 1-anilino-8-naphthalene sulfonate (ANS) with human red blood cells were studied. 2. ANS below 0.5 mM inhibits partially (20% maximum) the ouabain-insensitive Na+ and K+ influx and efflux. Above 0.5 mM ANS increases both Na+ and K+ leak fluxes. The increased cation leaks are larger for Na+ than K+. 3. The (Na+ +K+)-ATPase and ouabain-sensitive Na+ and K+ fluxes are inhibited by ANS. Ouabain-insensitive, Mg2+-dependent ATPase activity of ghosts is stimulated by [ANS] less than 0.3 mM and inhibited by [ANS] greater than 0.3 mM. 4. ANS also inhibits the Na+-dependent, ouabain-insensitive K+ influx that is inhibited by ethacrynic acid and furosemide. 5. Red cells become crenated with [ANS] less than 1 mM and sphere at [ANS] greater than 1 mM. In the former conditions hypotonic hemolysis is decreased whereas the latter increase osmotic fragility. 6. It is suggested that ANS expands the membrane asymmetrically by binding preferentially to the external membrane surface. 7. It is concluded that ANS is a general inhibitor of ion transport, particularly of those processes thought to involve facilitated-diffusion mechanisms. The increased cation leaks observed at high ANS concentrations may be related to prehemolytic membrane disruption. 8. The membrane perturbations caused by ANS are compared to those caused by other reversible inhibitors of anion exchange in red blood cells. Their possible modes of action are discussed.


Assuntos
Naftalenossulfonato de Anilina/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Eritrócitos/metabolismo , Adenosina Trifosfatases/metabolismo , Colina/metabolismo , Relação Dose-Resposta a Droga , Eritrócitos/ultraestrutura , Hemólise/efeitos dos fármacos , Humanos , Magnésio/metabolismo , Ouabaína/farmacologia , Potássio/metabolismo , Sódio/metabolismo
15.
Biochim Biophys Acta ; 553(1): 66-83, 1979 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-454588

RESUMO

The anion transport system of human red cells was isolated in vesicles containing the original membrane lipids and the 95 000 dalton polypeptides (band 3) by the method of Wolosin et al. (J. Biol. Chem. (1977) 252, 2419--2427). The vesicles have a functional anion transprot system since they display sulfate transport that is inhibited by the fluorescent probe 8-anilinonaphthalene 1-sulfonate (ANS) with similar potency as in red cells. The vesicles were labeled with the SH-specific probe fluorescein mercuric acetate (FMA). Labeling lowers FMA fluorescence, and is prevented or reversed by dithiothreitol, suggesting that the reaction is with a thiol group on the protein. Fluorescnece titrations show a maximum labeling stoichiometry of 1.3 +/- 0.4 mol FMA/mol 95 000 dalton polypeptide. The polarization of bound FMA fluorescence is high indicating that the probe is highly immobilized. Pretreatment with Cu2+ + o-phenanthroline under conditions that crosslink band 3 in ghosts decreases FMA labeling 50%. Differences in kinetics of FMA labeling in sealed and leaky vesicles suggest that the reactive SH group is located in the intravesicular portion of the protein (corresponding to the cytoplasmic surface of the red cell) and that FMA can cross the membrane. Inhibitors of anion transport have no effect on FMA labeling kinetics suggesting it is not transported via the anion transport system. Sulfate transport in the labeled vesicles remains fully functional. We detected self-energy transfer between bound FMA molecules by fluorescence depolarization. With excitation at 450--50 nm P decreases from 0.4, when less than half of the proteins are labeled, to 0.1 at saturation. This depolarization is not observed with red edge excitation (510--530 nm). Addition of 0.1% sodium dodecyl sulfate (SDS) changes P to 0.32, regardless of the excitation wavelength or degree of saturation with FMA. These results indicate that the band 3 proteins are close enough to allow energy transfer between fluorophores(Ro = 37.4 A), which does not occur upon red edge excitation or when the proteins are separated by SDS. We conclude that the functional anion transport system exists as a dimer or higher oligomer of band 3 proteins in these membranes, confirming previous suggestions derived using other methods. Future applications are discussed.


Assuntos
Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Canais Iônicos/metabolismo , Naftalenossulfonato de Anilina , Ânions , Transporte Biológico/efeitos dos fármacos , Cobre/farmacologia , Transferência de Energia , Humanos , Canais Iônicos/efeitos dos fármacos , Cinética , Manganês/farmacologia , Matemática , Fenantrolinas/farmacologia , Espectrometria de Fluorescência , Sulfatos/sangue
16.
Int J Cardiol ; 29(1): 71-8, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2262218

RESUMO

The association of atrial septal aneurysm and other cardiac abnormalities is reported in 14 consecutive cases diagnosed by cross sectional echocardiography. Color flow mapping was used in all cases in order to increase the accuracy in detecting associated lesions, especially small shunts at the atrial level. An atrial septal aneurysm occurred as an isolated lesion in just 1 patient (7%). In all other cases there was at least one associated cardiac defect. Atrial septal defect and prolapse of the leaflets of the mitral valve were particularly frequent, those lesions co-existing in half the patients. Although the lesion was not suspected clinically, physical examination, electrocardiography and chest X rays were abnormal in several patients, with a high incidence of electrocardiographic abnormalities and supraventricular arrhythmias in the overall group.


Assuntos
Arritmias Cardíacas/complicações , Aneurisma Cardíaco/diagnóstico , Comunicação Interatrial/complicações , Prolapso da Valva Mitral/complicações , Adulto , Idoso , Cardiomiopatias/complicações , Cardiomiopatias/diagnóstico , Cardiomiopatias/patologia , Criança , Pré-Escolar , Ecocardiografia Doppler , Eletrocardiografia , Feminino , Aneurisma Cardíaco/complicações , Septos Cardíacos/patologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade
17.
Int J Cardiol ; 56(1): 41-51, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8891804

RESUMO

Although apical hypertrophic cardiomyopathy is generally accepted as a form of hypertrophic cardiomyopathy, its underlying genetic factors, clinical course and complications may be different. The characteristics of 14 Brazilian patients with a diagnosis of apical hypertrophic cardiomyopathy are described. Symptoms were frequent and abnormal filling of the left ventricle by Doppler criteria was recorded in all patients. Rest electrocardiograms showed giant negative T waves in 5 patients, all had low exercise capacity on an exercise stress test while significant arrhythmias were detected by 24-h ambulatory monitoring in just one patient. Forty-eight first degree relatives were studied and 3 had some form of hypertrophy of the left ventricle as seen by echocardiography. Apical hypertrophic cardiomyopathy in Brazilians seems to be expressed somewhat differently from that reported in Japanese patients, since "giant' T waves are less frequent and women more involved.


Assuntos
Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/genética , Ecocardiografia Doppler/métodos , Adolescente , Adulto , Brasil , Cardiomiopatia Hipertrófica/fisiopatologia , Eletrocardiografia Ambulatorial , Teste de Esforço , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem
18.
Rev Saude Publica ; 24(6): 518-22, 1990 Dec.
Artigo em Português | MEDLINE | ID: mdl-2103073

RESUMO

The ethical-juridical concepts related to the civil responsibility of medical activity in liberal practice are brought up to date. To this end, the arguments which guide the shaping up of the contractual relationship between the physician and the client are analysed, as also are the foundations on which the notion of guilt--an essential component of civil responsibility, whether relating to technical acts of to those within the field of medical humanism--are grounded. The answers presented for the solution of this question by European juridical systems are given.


Assuntos
Ética Médica , Jurisprudência , Relações Médico-Paciente , Prática Privada , Responsabilidade Social , Legislação Médica
19.
Rev Saude Publica ; 35(5): 451-5, 2001 Oct.
Artigo em Português | MEDLINE | ID: mdl-11723516

RESUMO

OBJECTIVE: To identify the social first-year and senior undergraduate students of a healthcare management course used for selecting patients who need emergency medical care. METHODS: A random sample of 64 first-year and 25 senior year students of a healthcare management course in São Paulo, Brazil, were studied. To collect data, a survey instrument was developed with nine hypothetical simulated case scenarios, including the social criteria involved in the patient selection process, such as age, sex, economical status, life-style, and social duty. RESULTS: There were significant differences in the two groups concerning criteria such as the patient's life-style and economic status. CONCLUSIONS: The results suggest that the respondents accept the inclusion of social criteria in the decision-making process in a situation of scarce resources.


Assuntos
Serviços Médicos de Emergência , Seleção de Pacientes , Adulto , Fatores Etários , Idoso , Criança , Serviços Médicos de Emergência/economia , Ética , Feminino , Humanos , Estilo de Vida , Masculino , Fatores Sexuais , Fatores Socioeconômicos
20.
Rev Esc Enferm USP ; 33(1): 59-65, 1999 Mar.
Artigo em Português | MEDLINE | ID: mdl-10847094

RESUMO

It was carried out a study with the aim to analyse the autonomy of hospitalised elderly, based on the comprehension about their rights of information and the informed consent on proposals of diagnosis and therapeutics. The results showed patient's lack of information, dissatisfaction on the degree of information. It was also verified that the patient's family frequently acts as information intermediary between the health team and the patient. Therefore, autonomy process of decision making was compromised, as well as the informed consent of the elderly.


Assuntos
Idoso/psicologia , Hospitalização , Consentimento Livre e Esclarecido , Defesa do Paciente , Educação de Pacientes como Assunto/normas , Satisfação do Paciente , Comunicação , Feminino , Humanos , Masculino , Relações Profissional-Família , Inquéritos e Questionários
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