RESUMO
In this document, we present the effect of the surface modification of titanium dioxide particles with dicarboxylic acid on the rheological behavior of isotactic polypropylene composites. In addition to evaluating the effect of this type of modified fillers on the crystalline parameters such as long period, crystalline thickness and amorphous thickness, comparing it with unmodified fillers and pure polymer.
RESUMO
Currently, nanomaterials had been used for several applications; one of them is as bio-markers. These nanomaterials contain fluorescent compounds as effective indicators for imaging and other applications in Biotechnology. In previous studies, we proposed a functionalized nanomaterial-based biomarker from silica and Eysenhardtia Polystachia, a medicinal tree known in Mexico as "palo azul" (Kidneywood). Our previous results showed the feasibility of the nanomaterial obtained as bio-marker. In this article, our purpose is to evaluate the effects of extraction solvents on fluorescence of that biomarker. The photoluminescence (PL) effect was evaluated at different pH (4, 7.4 and 8); four extraction solvents, ethanol, methanol, methanol-ethanol and methanol-ethanol-water were evaluated. A molecular dynamics simulation was performed to recognize molecular interaction between the compounds of the extracts with solvent molecules and to investigate the solvent molecules effect on photoluminescence spectra. The results were also compared with rhodamine 6G and we found that, at physiological pH (7.4), the fluorescent-coated silica nanoparticles obtained were also stable. We found that extraction solvents could be used for obtaining different nanomaterials for specific applications, and also found the best extraction solvent for obtaining EP nanomaterials for health care applications, specifically for imaging techniques.
Assuntos
Biomarcadores/análise , Fabaceae/química , Extratos Vegetais/química , Solventes/química , Etanol/química , Fabaceae/metabolismo , Concentração de Íons de Hidrogênio , Metanol/química , Nanopartículas/química , Teoria Quântica , Rodaminas/química , Dióxido de Silício/química , Espectrofotometria Ultravioleta , Análise Espectral Raman , Eletricidade Estática , Água/químicaRESUMO
BACKGROUND/AIMS: Human papillomavirus (HPV) is an epitheliotropic, double-stranded DNA virus, and its high-risk genotypes are associated with human cancer. HPV genome has been detected in lung carcinomas in certain places around the world, including Mexico; however, the prevalence of this is unclear. In this study, we examine the frequency of high-risk HPV 16/18 in lung cancer tissues from a Mexican population. METHODS: 39 lung cancer specimens were analyzed by polymerase chain reaction (PCR) using HPV GP5+/GP6+ primers and then were genotyped using specific primers to HPV 16/18. Additionally, in situ hybridization (ISH) was performed using BIO-labeled oligonucleotide probes. RESULTS: Our results identified 15 positive cases (38.46%) for HPV 16 and 1 positive case (2.56%) for HPV 18 by PCR. ISH showed the presence of HPV DNA in 13 of 16 (81%) samples, in agreement with the PCR results. CONCLUSIONS: In this study, we detected HPV 16/18 gene sequences in lung cancer samples obtained from Mexican patients by PCR and ISH. We found the highest prevalence of HPV 16 infection in lung adenocarcinomas, suggesting that HPV infection may be associated with lung cancer. However, further studies are needed to elucidate the role of HPV in lung carcinogenesis.
Assuntos
Adenocarcinoma/virologia , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 18/isolamento & purificação , Neoplasias Pulmonares/virologia , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Adenocarcinoma/complicações , DNA Viral/genética , Feminino , Genótipo , Humanos , Hibridização in Situ Fluorescente , Neoplasias Pulmonares/complicações , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Infecções por Papillomavirus/complicações , Reação em Cadeia da Polimerase , PrevalênciaRESUMO
Pt-Pd core-shell nanoparticles were synthesized using a modified polyol method. A thermal method under refluxing, carrying on the reaction up to 285 °C, has been performed to reduce metallic salts using ethylene glycol as reducer and poly(N-vinyl-2-pyrrolidone) as protective reagent of the formed bimetallic nanoparticles. According to other works, this type of structure has been studied and utilized to successfully increase the catalytic properties of monometallic nanoparticles Pt or Pd. Core-shell bimetallic nanoparticles were structurally characterized using aberration-corrected scanning transmission electron microscopy (Cs-STEM) equipped with a high-angle annular dark field detector, energy-dispersive X-ray spectrometry (EDS), and electron energy-loss spectroscopy (EELS). The high-resolution elemental line scan and mappings were carried out using a combination of STEM-EDS and STEM-EELS. The obtained results show the growth of the Pd shell on the Pt core with polyhedral morphology. The average size of the bimetallic nanoparticles was 13.5 nm and the average size of the core was 8.5 nm; consequently, the thickness of the shell was around 2.5 nm. The growth of the Pd shell on the Pt core is layer by layer, suggesting a Frank-van der Merwe growth mechanism.
RESUMO
Casiopeínas are a new generation of anticancer drugs that have shown great in vitro and in vivo antineoplastic activities. Information about interaction drug-excipient, for developing a based-nanoparticle drug delivery system, has not been investigated yet. In order to elucidate if chitosan (CS) modifies the copper complex due to its interaction with Cu(2+) ion, different studies in aqueous media between CS and Casiopeina III-ia (Cas III-ia) were carried out. CS-Cas III-ia mixtures were characterized by viscosity curves, UV-vis, EPR, and in vivo activity against HeLa cell line. Rheological behavior showed a decrease of viscosity when the drug was present due to diminished electrostatic interactions of charged amine group. UV-vis results illustrate that Cas III-ia is not stable at low pH as a result of interaction with acetic acid. However, when chitosan is present at the acidic solution Cas III-ia is stable. These results are supported by EPR studies. Finally, activity of the drug against HeLa cell line was not modified. Therefore, the present work presents evidence that there is no breaking of copper complex due to interaction between CS and Cas III-ia in acidic media. In addition, Cas III-ia maintains both its stability and effectiveness against cancer cell line.
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Quitosana/química , Compostos Organometálicos/química , Sistemas de Liberação de Medicamentos , Espectroscopia de Ressonância de Spin Eletrônica , TermodinâmicaRESUMO
We study the confinement of a hydrophilic polymer (polyethylene glycol or PEG) between the bilayers of the zwitterionic surfactant tetradecyldimethyl aminoxide (C(14)DMAO). Small angle X-ray scattering and electron microscopy experiments show that the polymer modifies the physical properties of the lyotropic smectic (L(alpha)) phase. The observed effects are similar to those reported for anchored hydrophobically-modified polymers, indicating a strong interaction between PEG and the C(14)DMAO bilayers. Self-diffusion experiments performed in the lyotropic sponge (L(3)) phase show that the polymer adsorbs onto the surfactant membranes. This adsorption explains earlier observations: high polymer concentrations decrease the Gaussian rigidity of the membranes and a vesicular phase is stabilized.
RESUMO
The present investigation assesses the possible role of apoptosis and necrosis in intracellular antigen exposure of kidneys from Balb/c mice. Renal tissues were cultured and treated with chemicals to induce apoptosis and /or necrosis. The expression of intracellular antigens Sm, RNP, Ro and La were monitored with antibodies against these antigens. Main results confirm that renal intracellular antigens are released and exposed onto the surface of apoptotic and necrotic cells, therefore these antigens become an easy target of autoantibodies. This mechanism may be important in the lupus nephritis pathogenesis.
Assuntos
Autoantígenos/biossíntese , Rim/imunologia , Rim/patologia , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Necrose/induzido quimicamente , Técnicas de Cultura de Tecidos , Proteínas Centrais de snRNP , Antígeno SS-BRESUMO
Small (1-5 nm) metallic nanoparticles of Pt, Au, and Au/Pt of different nominal compositions in colloidal form were synthesized by a chemical reduction method using polymer (PVP) as protecting agent. Analytical techniques like HREM and UV-vis spectroscopy have been used to characterize the morphology and structural properties of these small particles. Theoretical simulations based on molecular dynamical have been used to interpret the experimental structural results and analyze the macroscopic properties like stability and catalytic selectivity of these nanoparticles based on the morphology and atomic distribution in the clusters.
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Ouro/química , Nanotecnologia/métodos , Nanotubos/química , Platina/química , Catálise , Elétrons , Íons , Teste de Materiais , Metanol/química , Microscopia Eletrônica , Microscopia Eletrônica de Transmissão , Polímeros/química , Espectrofotometria , Espectrofotometria Infravermelho , Raios UltravioletaRESUMO
OBJECTIVE: Present study addresses the issue whether apoptosis and necrosis increases the antigenicity of proteins recognized by antinuclear antibodies. MATERIAL AND METHODS: HEp-2 cells were cultured in standard conditions; apoptosis was induced by camptothecin and necrosis by mercuric chloride. Protein antigenicity of cell extracts was tested onto nitrocellulose membranes and probed with positive or negative sera for antinuclear antibodies by a luminescent-dot-ELISA system. RESULTS: Apoptotic changes in HEp-2 cells appeared by 24 hours of camptothecin exposure, meanwhile the necrotic features become visible earlier. Luminescence was significantly superior in ANA positive sera than in ANA negative controls. Antinuclear antibody sera recognized better the antigens from the apoptotic and necrotic cells than controls without chemical treatments. CONCLUSIONS: Apoptosis and necrosis increase the ANA binding by better availability of intracellular antigens, or by disclosing cryptic epitopes.
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Anticorpos Antinucleares/imunologia , Apoptose/imunologia , Autoantígenos/imunologia , Doenças Autoimunes/imunologia , Anticorpos Antinucleares/sangue , Reações Antígeno-Anticorpo , Antígenos de Neoplasias/imunologia , Apoptose/efeitos dos fármacos , Doenças Autoimunes/patologia , Camptotecina/farmacologia , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/imunologia , Linhagem Celular Tumoral/patologia , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Marcação In Situ das Extremidades Cortadas , Neoplasias Laríngeas/imunologia , Neoplasias Laríngeas/patologia , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/imunologia , Cloreto de Mercúrio/farmacologia , Doença Mista do Tecido Conjuntivo/sangue , Doença Mista do Tecido Conjuntivo/imunologia , Necrose , Proteínas de Neoplasias/imunologia , Esclerodermia Difusa/sangue , Esclerodermia Difusa/imunologia , Síndrome de Sjogren/sangue , Síndrome de Sjogren/imunologiaRESUMO
The association of maternal pemphigus foliaceus (PF) with neonatal PF is rare and may be secondary to transplacental passage of PF autoantibodies. We describe a 25-year-old patient with PF who was delivered of two consecutive babies, one with classic skin lesions of PF and another that was normal. The neonate with PF was born when the mother had widespread skin disease; the normal newborn was born when the mother was in partial remission. The titers of PF autoantibodies were higher in the mother's serum and the cord serum of the baby with PF than in the mother during partial remission and the unaffected baby. The mother and affected baby had autoantibodies to desmoglein 1. Furthermore, cord blood from the baby with PF induced skin disease when injected into mice. In this case, maternal PF was associated with neonatal PF when the titers of maternal anti-desmoglein 1 autoantibodies were elevated. The cutaneous disease in neonatal PF is due to anti-desmoglein 1 autoantibodies.
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Autoanticorpos/análise , Imunidade Materno-Adquirida , Pênfigo/imunologia , Complicações Infecciosas na Gravidez/imunologia , Resultado da Gravidez , Adulto , Animais , Feminino , Sangue Fetal/imunologia , Humanos , Recém-Nascido , Troca Materno-Fetal , Camundongos , Camundongos Endogâmicos BALB C , Pênfigo/diagnóstico , Gravidez , Complicações Infecciosas na Gravidez/diagnósticoRESUMO
OBJECTIVES: Ro ribonucleoproteins are of particular interest because they are serologic markers of photosensitive variants of lupus such as the subacute cutaneous lupus erythematosus (SCLE), in which the polycyclic skin lesions are triggered by exposure to the sun. We study the role of apoptosis in the expression of Ro antigen. METHODS: We used UV-A irradiated keratinocytes. RESULTS: We demonstrate in cultured human UVA-irradiated keratinocytes that the enhanced expression of Ro60 ribonucleoprotein is caused by antigenic redistribution consecutive to Fas-L and Bax gene activation.
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Apoptose/genética , Autoantígenos/metabolismo , Queratinócitos/efeitos da radiação , Glicoproteínas de Membrana/genética , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas/genética , RNA Citoplasmático Pequeno , Ribonucleoproteínas/metabolismo , Transcrição Gênica , Autoantígenos/efeitos da radiação , Western Blotting , Células Cultivadas , Proteína Ligante Fas , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Processamento de Imagem Assistida por Computador , Hibridização In Situ , Queratinócitos/metabolismo , Masculino , Ribonucleoproteínas/efeitos da radiação , Raios Ultravioleta , Proteína X Associada a bcl-2RESUMO
BACKGROUND: Ro60 ribonucleoprotein is a conserved molecule belonging to the family of Ro ribonucleoproteins and targeted by autoantibodies produced in patients with systemic lupus erythematosus or Sjogren's syndrome. Ro60 plays a role in postranscription events, as well as in the nucleocytoplasmic shuttling of RNA polymerase III transcripts. OBJECTIVE: To evaluate the in vitro effects of Ro60 on T3 RNA polymerase transcription. METHODS: Ro60 ribonucleoprotein was affinity-purified from human spleen extracts using 4B-Sepharose linked to anti-Ro60 monoclonal antibodies. Purified Ro60 was incorporated into the T3 RNA polymerase transcription reaction system using pTRI-beta-Actin-human DNA as a template. RESULTS: Ro60 inhibited initiation of the transcription process in a dose-dependent manner; neither elongation nor termination was affected by Ro. CONCLUSION: In vitro, Ro60 appears to inhibit the transcription of a T3 RNA polymerase-dependent template.
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Autoantígenos/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , RNA Citoplasmático Pequeno , Ribonucleoproteínas/metabolismo , Transcrição Gênica/fisiologia , Adulto , Autoantígenos/isolamento & purificação , Autoantígenos/farmacologia , Western Blotting , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Masculino , Valores de Referência , Ribonucleoproteínas/isolamento & purificação , Ribonucleoproteínas/farmacologia , Sensibilidade e Especificidade , Baço/química , Baço/metabolismo , Transcrição Gênica/efeitos dos fármacosRESUMO
BACKGROUND: Serum antibodies in scleroderma patients are generally directed against the nucleolus and centromeres. A small proportion of patients have serum antibodies to the centrioles and mitotic apparatus. OBJECTIVE: To determine the prevalence of serum autoantibodies against the mitotic apparatus in scleroderma patients. MATERIAL AND METHODS: Sera from 113 patients with various forms of scleroderma were tested for antinuclear antibodies by indirect immunofluorescence on HEp-2 cells. The specificity of the antibodies was determined by Western blot. RESULTS: Only two scleroderma sera recognized the mitotic apparatus. Western blot results showed that in both cases the target was an about 235 kDa protein corresponding to the NuMA determinant. Affinity-purified anti-NuMa antibodies were used to perform immunolocalization in synchronized HEp-2 cells using scanning laser confocal microscopy. The anti-NuMA autoantibodies recognized the mitotic asters but neither the centrioles nor the microtubules. CONCLUSION: Our data suggest that anti-NuMA autoantibodies may be devoid of clinical significance in scleroderma. However, they remain useful as probes in cell biology studies.
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Anticorpos Antinucleares/análise , Lúpus Eritematoso Sistêmico/imunologia , Escleroderma Sistêmico/imunologia , Fuso Acromático/imunologia , Anticorpos Antinucleares/imunologia , Western Blotting , Células Cultivadas , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Lúpus Eritematoso Sistêmico/sangue , Masculino , Microscopia Confocal , Escleroderma Sistêmico/sangue , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To determine whether UV-A irradiation induces synthesis of inflammatory cytokines in the skin. METHODS: Human keratinocytes and dermal fibroblasts were cultured and exposed to various doses of UV-A radiation. The cellular distribution of IL-6 and TNF alpha was determined by indirect immunofluorescence and by flow cytometry with monoclonal anti-IL-6 and anti-TNF alpha antibodies. Cytokine production was measured in the supernatants using an ELISA. IL-6 and TNF alpha transcription induced by UV-A was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification. RESULTS: IL-6 and TNF alpha were detected in small amounts in nonUV-A-irradiated cell. UV-A exposure was followed by significant increases in IL-6 and TNF alpha expression and by small increases in IL-6 and TNF alpha levels in culture supernatants. RT-PCR demonstrated a UV-A-mediated increase in the transcription of IL-6 and TNF alpha genes. CONCLUSION: Synthesis of IL-6 and TNF alpha can be induced by UV-A irradiation. This effect of UV-A may contribute to the inflammatory skin changes seen during lupus flare-ups after sun exposure.
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Derme/efeitos da radiação , Interleucina-6/biossíntese , Queratinócitos/efeitos da radiação , Fator de Necrose Tumoral alfa/biossíntese , Raios Ultravioleta , Western Blotting , Extratos Celulares/química , Tamanho Celular/efeitos da radiação , Células Cultivadas , Derme/citologia , Derme/metabolismo , Relação Dose-Resposta à Radiação , Ensaio de Imunoadsorção Enzimática , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Interleucina-6/genética , Queratinócitos/citologia , Queratinócitos/metabolismo , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica/efeitos da radiação , Fator de Necrose Tumoral alfa/genéticaRESUMO
OBJECTIVE: A prospective study to evaluate the confidence level and predictive value of the fine needle aspiration biopsy was performed in the Oncology Service, "Hospital 20 de Noviembre, ISSSTE", Mexico City. MATERIAL AND METHODS: The cases with a palpable breast tumor, histologically confirmed who presented from 1992 to 1994 were included. One aspirate was done in each patient and these were reviewed by the same pathologist. We determined sensitivity, specificity and predictive value of the test. Age, border characteristics, size and mobility of the tumor were evaluated by Bayesian analysis. RESULTS: From 213 aspirates, 199 were elegible for diagnosis, 98 (46%) had a diagnosis of carcinoma, 13 were acellular and one suggestive. The acellular diagnoses were considered negative and suggestive positive, for analysis purposes. Mean age and tumor size were: 46.6 years (range 14-90) and 3.7 cm. (range 1-13) respectively. Sensitivity (0.932), specificity (0.973) and positive predictive value (96.9%) were estimated. We observed a high probability of true positive [P(D+/T+)] > 0.8 results in patients between 40 and 60 years of age, irregular borders, size > 2 cm and fixed lesions. CONCLUSIONS: The test has a high confidence level and in presence of two or more of the clinical factors mentioned, definitive decisions regarding treatment could be taken, without need of histologic confirmation.
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Biópsia por Agulha/normas , Neoplasias da Mama/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Pessoa de Meia-Idade , Palpação , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
These studies were carried out to examine the presence of the inflammatory cytokines IL-6 and TNFalpha in kidneys of patients with lupus nephritis as an indicator of their possible role in its pathogenesis. A total of 19 kidney biopsies from patients with type III or IV lupus nephritis were processed by direct immunofluorescence using monoclonal anti-IL-6 and TNFalpha antibodies. Local expression of these genes was demonstrated both by in situ hybridization and by reverse transcriptase-PCR amplification of total RNA isolated from kidney tissue. Fifty-two percent of the biopsies exhibited IL-6 and TNFalpha deposited along the glomeruli and tubules; in situ expression of these cytokines was demonstrated in 6 biopsies with type IV, and 1 with type III nephritis. Inflammatory cytokines are actively synthesized in the kidneys of patients with lupus nephritis and therefore, may play a role in its pathogenesis.
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Genes/genética , Interleucina-6/genética , Nefrite Lúpica/genética , Fator de Necrose Tumoral alfa/genética , Adolescente , Adulto , Feminino , Técnica Direta de Fluorescência para Anticorpo , Expressão Gênica/genética , Humanos , Hibridização in Situ Fluorescente , Rim/química , Rim/metabolismo , Masculino , RNA Mensageiro/análiseRESUMO
PURPOSE AND METHODS: We investigated the expression and localization of topoisomerase I by Western blot and indirect fluorescent antibody assay, respectively, using anti-Scl-70/topo I from patients with diffuse scleroderma. The contribution of topoisomerase I to DNA replication was assessed using cells treated with the topoisomerase I inhibitor camptothecin. RESULTS: Scl-topo I was detected at all cell cycle phases as a single immunoreactive band of 100 kDa. Extracts from cells in the S phase contained the largest amount of immunoreactive Scl-70/topo I. Variations in the subcellular distribution of Scl-70/topo I were seen throughout the cell cycle, with a speckled nucleoplasmic distribution during G1 contrasting with concentration within the nucleolus during S. Camptothecin exposure blocked topoisomerase I expression and caused a significant decrease in DNA production. CONCLUSION: These data suggest (1) that topomerase I is active mainly during the S phase and contributes to DNA replication, and (2) that topoisomerase I may be involved in ribosomal gene transcription.
Assuntos
DNA Topoisomerases Tipo I/metabolismo , Proteínas Nucleares/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Autoantígenos/análise , Autoantígenos/genética , Autoantígenos/metabolismo , Western Blotting , Camptotecina/farmacologia , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/imunologia , Divisão Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Replicação do DNA/imunologia , DNA Topoisomerases Tipo I/análise , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Hidroxiureia/farmacologia , Índice Mitótico , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Inibidores da Síntese de Ácido Nucleico/farmacologia , Fase S , Escleroderma Sistêmico/enzimologia , Escleroderma Sistêmico/metabolismo , Inibidores da Topoisomerase I , Células Tumorais Cultivadas/química , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/enzimologiaRESUMO
Studies of Ro ribonucleoprotein are important in rheumatology, since anti-Ro antibodies are probably involved in the pathogenesis of congenital heart block and subacute cutaneous lupus erythematosus. In addition, the phosphorylation-dephosphorylation cycle modulates binding of ribonucleoproteins to RNA, a process that might affect the antigenicity and function of the Ro protein. The present study was designed to determine whether Ro can be phosphorylated by tyrosine kinase. To answer this question, synchronized HEp-2 cells were phosphorylated in vivo with exogenous 32P, and Ro ribonucleoprotein previously subjected to metabolic radiolabeling was immunoprecipitated by monoclonal anti-Ro antibodies and examined by SDS-PAGE and autoradiography. The main results were as follows: first, Ro ribonucleoprotein was phosphorylated in vivo; second, Ro was found to have phosphorylable tyrosine residues; third, tyrosine kinase participated in the phosphorylation of Ro; and fourth, phosphorylation did not change the recognition pattern of Ro by anti-Ro antibodies. In conclusion, Ro60 is phosphorylated by tyrosine kinase.
Assuntos
Autoantígenos/metabolismo , Proteínas Tirosina Quinases/metabolismo , RNA Citoplasmático Pequeno , Ribonucleoproteínas/metabolismo , Anticorpos Monoclonais/imunologia , Autoantígenos/imunologia , Western Blotting , Divisão Celular , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Soros Imunes/imunologia , Índice Mitótico , Fosforilação , Testes de Precipitina , Ribonucleoproteínas/imunologia , Células Tumorais CultivadasRESUMO
OBJECTIVES: To determine whether annular rDNA is complexed with the nuclear envelope proteins. METHODS: From a batch of lupus sera with anti-nDNA, we selected a lupus serum containing annular anti-nDNA autoantibodies resistant to DNase digestion and used it to isolate several cDNA clones from a lambda gt11 HeLa cell library. RESULTS: The cloned fusion protein immunoadsorbed the annular anti-nDNA autoantibodies, and the immunoaffinity autoantibodies eluted from the recombinant filters produced an annular pattern around the nucleus in fluorescent assays on HEp-2 cells; by Western blot, they also recognized a 70 kDa protein from HEp-2 cell extracts. Annular-lambda gt11 lysogens generated in E. coli Y1089 produced a fusion protein that recognized annular anti-nDNA autoantibody-containing lupus sera by Western blot. The recombinant filters and annular fusion protein were also recognized by a prototype anti-lamin serum. To determine whether the annular recombinant protein bound DNA, an interaction assay was performed in vitro using DNA minicircles and DNA from HEp-2 cells; this assay resulted in a slowing of the electrophoretic mobility of the DNA. CONCLUSIONS: 1) The annular DNA in eukaryotic cells is complexed with nuclear envelope proteins. 2) Annular anti-nDNA autoantibodies from lupus patients cross-react with perinuclear proteins. 3) Perinuclear proteins recognized by anti-nDNA are lamins. 4) An interaction between DNA and the 70 kDa protein is inducible in vitro. Whether this interaction affects cell function is still unknown.
Assuntos
Anticorpos Antinucleares/imunologia , DNA/imunologia , Membrana Nuclear/metabolismo , Proteínas Nucleares/imunologia , Autoanticorpos/imunologia , Reações Cruzadas , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Peso Molecular , Proteínas Nucleares/química , Proteínas RecombinantesRESUMO
Studies of complexation equilibria of the antibiotic anions nalidixate and cinoxacinate with [Cu(phen)]2+ and [Cu(bipy)]2+ are reported. These studies indicate that the stability of this type of complex is strongly related to the metal environment. A correlation between the stability constants, determined here, with the sigma donation character of the ligand is proposed. This study shows that the stability constant for the reaction between the quinolones and the moiety [Cu(N-N)]2+ is dependent on the coordinate diamine to the metal ion. This is in agreement with previous studies where other physical properties as their electronic absorption spectra in the visible region, display similar behavior. These results suggest that inside the living cells, a possible interaction with some metal ion will be strongly controlled by the type of ligand bound to the cation.