Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Arch. Soc. Esp. Oftalmol ; 98(11): 633-639, nov. 2023. tab
Artigo em Espanhol | IBECS | ID: ibc-227202

RESUMO

Objetivo Evaluar el impacto en la calidad de vida (CdV) entre diferentes enfermedades de la retina como el edema macular diabético (EMD), la oclusión venosa retiniana (OVR), la miopía patológica (MP), la degeneración macular asociada a la edad neovascular (DMAEn) y la coriorretinopatía serosa central (CSC). Métodos Se realizó un estudio transversal en 241 pacientes afectados de EMD (n=44), OVR (n=41), MP (n=34) y DMAEn (n=85) que recibieron inyecciones intravítreas por presencia de edema macular o neovascularización. Los pacientes con CSC incluidos (n=37) eran candidatos a tratamiento con láser. Los pacientes completaron el National Eye Visual Functioning Questioning-25 (NEIVFQ-25). Se registró la mejor agudeza visual corregida (MAVC). Resultados Existieron diferencias significativas entre subgrupos para todos los dominios, excepto para la visión general, en la que todas las puntuaciones entre enfermedades oscilaron entre 40,7 y 45,2 sobre 100 (p=0,436), a pesar de la diferencia en MAVC (CSC: 86,3±11,9; OVR: 78,5±15,5; EMD: 73,3±15,2; DMAEn: 72,9±12,6 y MP: 68,5±18,1 letras, respectivamente (p<0,001). La puntuación total más baja se observó en la MP (52,1±20,9), seguida de DMAEn (55,3±20,8), OVR (65,0±22,3), EMD (68,6±21,0) y CSC (70,9±16,2). El grupo con EMD tuvo la peor puntuación para la salud general (38,9±21,4). La salud mental y las dificultades de rol fueron más bajas en la MP (48,2±28,8 y 48,2±31,9, p<0,007). Conclusiones Este estudio revela las diferencias en la CdV entre EMD, OVR, DMAEn, MP y CSC, describiendo las diferentes repercusiones que pueden sufrir, observándose un mayor impacto en la MP y la DMAEn (AU)


Purpose To assess the impact on the quality of life (QoL) among different retinal diseases such as diabetic macular edema (DME), retinal vein occlusion (RVO), pathologic myopia (PM), neovascular age-related macular degeneration (nAMD) and central serous chorioretinopathy (CSC). Methods A cross-sectional study was carried out in 241 patients, affected by DME (n=44), RVO (n=41), PM (n=34) and nAMD (n=85) receiving intravitreal injections due to the presence of macular edema or choroidal neovascularization. The CSC patients included (n=37) were candidates for laser treatment. The patients included completed the National Eye Visual Functioning Questioning-25 (NEIVFQ-25). Best eye visual acuity (BEVA) was recorded using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. Results There were significant differences between subgroups for all the domains, except for the general vision in which all scores among diseases ranged from 40.7 to 45.2 out of 100 (P=.436), despite the difference in BEVA (CSC: 86.3±11.9; RVO: 78.5±15.5, DME: 73.3±15.2, nAMD: 72.9±12.6 and PM: 68.5±18.1 letters, respectively; P<.001). The lowest VFQ-25 total score was observed in the PM patients (52.1±20.9), followed by nAMD (55.3±20.8), RVO (65.0±22.3), DME (68.6±21.0) and CSC (70.9±16.2). The DME group reported the worst score for general health (38.9±21.4). Mental health and role difficulties were lowest for PM (48.2±28.8 and 48.2±31.9, P<.007). Conclusions This study reveals the differences in the QoL among DME, RVO, nAMD, PM and CSC, describing the different repercussions that they can suffer, observing a higher impact in PM and nAMD (AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Qualidade de Vida , Doenças Retinianas/classificação , Doenças Retinianas/psicologia , Estudos Transversais , Retinopatia Diabética , Oclusão da Veia Retiniana , Degeneração Macular , Coriorretinopatia Serosa Central
2.
Arch Soc Esp Oftalmol (Engl Ed) ; 98(11): 633-639, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37748684

RESUMO

PURPOSE: To assess the impact on the quality of life (QoL) among different retinal diseases such as diabetic macular edema (DME), retinal vein occlusion (RVO), pathologic myopia (PM), neovascular age-related macular degeneration (nAMD) and central serous chorioretinopathy (CSC). METHODS: A cross-sectional study was carried out in 241 patients, affected by DME (n=44), RVO (n=41), PM (n=34) and nAMD (n=85) receiving intravitreal injections due to the presence of macular edema or choroidal neovascularization. The CSC patients included (n=37) were candidates for laser treatment. The patients included completed the National Eye Visual Functioning Questioning-25 (NEI VFQ-25). Best eye visual acuity (BEVA) was recorded using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. RESULTS: There were significant differences between subgroups for all the domains, except for the general vision in which all scores among diseases ranged from 40.7 to 45.2 out of 100 (P=.436), despite the difference in BEVA (CSC: 86.3±11.9; RVO: 78.5±15.5, DME: 73.3±15.2, nAMD: 72.9±12.6 and PM: 68.5±18.1 letters respectively; P<.001). The lowest VFQ-25 total score was observed in the PM patients (52.1±20.9), followed by nAMD (55.3±20.8), RVO (65.0±22.3), DME (68.6±21.0) and CSC (70.9±16.2). The DME group reported the worst score for general health (38.9±21.4). Mental health and role difficulties were lowest for PM (48.2±28.8 and 48.2±31.9, P<.007). CONCLUSIONS: This study reveals the differences in the QoL among DME, RVO, nAMD, PM and CSC, describing the different repercussions that they can suffer, observing a higher impact in PM and nAMD.


Assuntos
Retinopatia Diabética , Degeneração Macular , Edema Macular , Doenças Retinianas , Oclusão da Veia Retiniana , Humanos , Edema Macular/etiologia , Qualidade de Vida , Degeneração Macular/psicologia , Estudos Transversais , Transtornos da Visão
3.
Chemosphere ; 341: 139856, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37598949

RESUMO

Microalgae are the main source of third-generation biofuels because they have a lipid content of 20-70%, can be abundantly produced and do not compete in the food market besides other benefits. Biofuel production from microalgae is a promising option to contribute for the resolution of the eminent crisis of fossil energy and environmental pollution specially in the transporting sector. The choice of lipid extraction method is of relevance and associated to the algae morphology (i.e., rigid cells). Therefore, it is essential to develop suitable extraction technologies for economically viable and environment-friendly lipid recovery processes with the aim of achieving a commercial production of biofuels from this biomass. This review presents an exhaustive analysis and discussion of different methods and processes of lipid extraction from microalgae for the subsequent conversion to biodiesel. Physical methods based on the use of supercritical fluids, ultrasound and microwaves were reviewed. Chemical methods using solvents with different polarities, aside from mechanical techniques such as mechanical pressure and enzymatic methods, were also analyzed. The advantages, drawbacks, challenges and future prospects of lipid extraction methods from microalgae have been summarized to provide a wide panorama of this relevant topic for the production of economic and sustainable energy worldwide.


Assuntos
Biocombustíveis , Microalgas , Lipídeos , Alimentos , Solventes , Biomassa , Óleos
4.
Water Environ Res ; 90(12): 2114-2125, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30538020

RESUMO

Adsorption of heavy metals on modified orange biomass has been studied. This biomass was treated with NaOH and CaCl2 to improve its adsorption properties. Kinetic and thermodynamic studies of the adsorption of Cd2+, Ni2+, Cu2+, and Zn2+ were performed at different operating conditions, including competitive adsorption studies with binary metallic mixtures. Results show that this adsorption process was endothermic where an ion exchange mechanism played a relevant role. Adsorbent effectiveness decreased in binary solutions, indicating a strong antagonistic adsorption behavior caused by counter-ions. This antagonistic adsorption was highly dependent on the counter-ion type and its concentration. Multicomponent adsorption of Cu2+ ions was not significantly affected by the presence of other metallic counter-ions, whereas the adsorption of Ni2+ could be totally suppressed by the other ions. The modeling of binary adsorption isotherms was successful using the modified Langmuir equation, which outperformed the Ideal Absorbed Solution Theory-Sips and modified Redlich-Peterson models.


Assuntos
Biomassa , Citrus sinensis/química , Metais Pesados/química , Poluentes Químicos da Água/química , Adsorção , Frutas , Cinética , Termodinâmica
5.
Persoonia ; 41: 39-55, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30728598

RESUMO

Over the past few years, symptoms akin to late blight disease have been reported on a variety of crop plants in South America. Despite the economic importance of these crops, the causal agents of the diseases belonging to the genus Phytophthora have not been completely characterized. In this study, a new Phytophthora species was described in Colombia from tree tomato (Solanum betaceum), a semi-domesticated fruit grown in northern South America. Comprehensive phylogenetic, morphological, population genetic analyses, and infection assays to characterize this new species, were conducted. All data support the description of the new species, Phytophthora betacei sp. nov. Phylogenetic analyses suggest that this new species belongs to clade 1c of the genus Phytophthora and is a close relative of the potato late blight pathogen, P. infestans. Furthermore, it appeared as the sister group of the P. andina strains collected from wild Solanaceae (clonal lineage EC-2). Analyses of morphological and physiological characters as well as host specificity showed high support for the differentiation of these species. Based on these results, a complete description of the new species is provided and the species boundaries within Phytophthora clade 1c in northern South America are discussed.

6.
Parasite Immunol ; 38(8): 496-502, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27104482

RESUMO

An oil-based formulation of the EG95 vaccine to protect grazing animals against infection with Echinococcus granulosus was formulated in Argentina. The efficacy of the vaccine was monitored by serology in sheep and llama (Lama glama) and was compared to the serology in sheep previously published using a QuilA-adjuvanted vaccine. Long-term efficacy was also tested in sheep by challenging with E. granulosus eggs of the G1 strain 4 years after the beginning of the trial. The serological results for both sheep and llama were similar to those described previously, except that there was a more rapid response after the first vaccination. A third vaccination given after 1 year resulted in a transient boost in serology that lasted for about 12 months, which was similar to results previously described. Sheep challenged after 4 years with three vaccinations presented 84·2% reduction of live cysts counts compared with control group, and after a fourth vaccination prior to challenge, this reduction was 94·7%. The oil-based vaccine appeared to be bio-equivalent to the QuilA vaccine.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Helmintos/imunologia , Camelídeos Americanos/imunologia , Equinococose/veterinária , Echinococcus granulosus/imunologia , Proteínas de Helminto/imunologia , Doenças dos Ovinos/prevenção & controle , Ovinos/imunologia , Vacinação/veterinária , Adjuvantes Imunológicos , Animais , Argentina , Equinococose/imunologia , Equinococose/parasitologia , Imunização Secundária , Saponinas de Quilaia/imunologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Vacinas/imunologia
8.
ACS Appl Mater Interfaces ; 5(3): 505-10, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23281655

RESUMO

Composite materials made of epoxy resin and barium titanate (BT) electrospun nanostructured fibers were prepared. BT fibers were synthesized from a sol based on barium acetate, titanium isopropoxide, and poly(vinyl pyrrolidone). The fibers were heat-treated at different temperatures and characterized by X-ray diffraction, scanning electron microscopy (SEM), and Raman spectroscopy. Mats of BT fibers heat-treated at 800 °C were embedded in epoxy resin into suitable molds. The composites were characterized by SEM, and dielectric measurements were performed by means of dielectric spectroscopy. The dielectric permittivity and dielectric modulus of epoxy resin/BT-fiber composites were measured for two types of samples: with the electrodes parallel and perpendicular to the BT fiber layers. Interestingly, composite samples with electrodes perpendicular to the fiber layers and a BT content as low as 2 vol % led to dielectric permittivities three times higher than that of pure epoxy resin.

9.
Br J Cancer ; 102(4): 774-82, 2010 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-20087350

RESUMO

BACKGROUND: To date, there are few reports on gene products contributing to colon cancer progression. METHODS: We used a gene trap comprised of an enhanced retroviral mutagen (ERM) cassette that includes a tetracycline-responsive promoter upstream of a haemagglutinin (HA) tag and a splice donor site. Integration of the ERM within an endogenous gene yields a tetracycline-regulated HA-tagged transcript. We transduced RKO colon cancer cells expressing a tetracycline trans-activator-off with the ERM-encoding retrovirus and screened for enhanced migration. RESULTS: One clone showed fivefold enhanced migration with tetracycline withdrawal. Rapid amplification of cDNA ends identified the trapped gene as the chloride channel 4 (CLCN4) exchanger. Stable expression of a CLCN4 cDNA enhanced motility, whereas cells knocked down or null for this transcript showed reduced migration/invasion. CLCN4-overexpressing RKO colon cancer cells were more resistant than controls to proton load-induced cytotoxicity, consistent with the H(+)-extruding function of this antiporter. Intra-splenic delivery of RKO-CLCN4 transfectants, but not controls, yielded liver metastases, and transcript levels were higher in colon cancer metastases to the liver when compared with primary tumours. CONCLUSIONS: CLCN4 is a novel driver of colon cancer progression.


Assuntos
Adenocarcinoma/patologia , Movimento Celular/genética , Canais de Cloreto/fisiologia , Neoplasias do Colo/patologia , Adenocarcinoma/genética , Animais , Células Cultivadas , Canais de Cloreto/genética , Canais de Cloreto/isolamento & purificação , Clonagem Molecular/métodos , Neoplasias do Colo/genética , Progressão da Doença , Células HCT116 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/secundário , Camundongos , Camundongos Nus , Invasividade Neoplásica , Metástase Neoplásica , Transplante de Neoplasias , Transplante Heterólogo
10.
Rev. obstet. ginecol. Venezuela ; 68(4): 240-247, dic. 2008. tab
Artigo em Espanhol | LILACS | ID: lil-522937

RESUMO

Detección y tipificación del VPH mediante Reacción en Cadena de la polimerasa con iniciadores genéricos MY09 y MY11 y RCP-Múltiple, en muestras de pacientes con diagnóstico citológico de coilocitosis y lesión intraepitelial escamosa de bajo grado, diagnóstico clínico de condilomatosis papilomatosis. Se procesaron 70 muestras citológicas del área genital a las que se realizó extracción de ADN y detección y tipificación viral mediante técnicas moleculares (RCP y RCP múltiple). Laboratorio de Genética Molecular del Instituto de Oncología Hematología. De las muestras evaluadas, 31 resultaron positivas en la detección molecular del VPH. De éstas, 29 correspondieron a VPH de bajo riesgo (tipos 11 y/o 6), una a infección mixta con bajo y alto riesgo (tipos 6 y 33) y otra a coinfección con virus de alto riesgo (tipos 18 y 33). Los resultados obtenidos resaltan la utilidad de la RCP en el diagnóstico y tipificación del VPH y ponen en evidencia una relación, ya establecida, entre VPH de bajo riesgo y displasias leves, así como la posible sobrestimación de infección por VPH en los diagnósticos de referencia.


Assuntos
Humanos , Feminino , Infecções por Papillomavirus/diagnóstico , Papiloma/diagnóstico , Reação em Cadeia da Polimerase/métodos , Técnicas Citológicas/métodos , Ginecologia , Oncologia
11.
Tissue Cell ; 35(1): 59-67, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12589730

RESUMO

Lipid bodies (LB), lipid-rich inclusions abundantly present in cells engaged in inflammation, are specialized intracellular domains involved in generating inflammatory mediators, the eicosanoids. Since the acute Trypanosoma cruzi infection triggers a potent inflammatory reaction characterized by a great increase of peripheral blood monocyte (PBM) and macrophage numbers, we investigated the LB occurrence in these cells. The experimental rat infection by T. cruzi (Y strain) induced significant increase of the LB numbers in peritoneal macrophages at day 6 and 12, accompanied by significant enhancement of Prostaglandin E(2) (PGE(2)) production, as measured by EIA. At day 12, ultrastructural analysis of the heart, a target organ of the disease, showed numerous macrophages with LB prominently increased in number (mean of 8.3 per section view, range of 1-25) compared to controls (mean of 2.6 per section view, range of 0-3) and size. PBM from all groups rarely showed LB. Our results demonstrate, for the first time, that T. cruzi infection in rats elicits important LB formation in inflammatory macrophages but not in PBM. The increase in LB numbers during infection positively correlates with increased generation of PGE(2), suggesting that LB may have a role in the heightened eicosanoid production observed during T. cruzi infection.


Assuntos
Doença de Chagas/metabolismo , Dinoprostona/metabolismo , Corpos de Inclusão/metabolismo , Metabolismo dos Lipídeos , Macrófagos/metabolismo , Monócitos/metabolismo , Animais , Doença de Chagas/patologia , Feminino , Macrófagos/parasitologia , Macrófagos/ultraestrutura , Microscopia Eletrônica , Monócitos/parasitologia , Monócitos/ultraestrutura , Miocardite/patologia , Peritonite/metabolismo , Peritonite/patologia , Ratos
12.
EMBO J ; 20(8): 1829-39, 2001 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-11296217

RESUMO

The small ribosomal subunit is responsible for the decoding of genetic information and plays a key role in the initiation of protein synthesis. We analyzed by X-ray crystallography the structures of three different complexes of the small ribosomal subunit of Thermus thermophilus with the A-site inhibitor tetracycline, the universal initiation inhibitor edeine and the C-terminal domain of the translation initiation factor IF3. The crystal structure analysis of the complex with tetracycline revealed the functionally important site responsible for the blockage of the A-site. Five additional tetracycline sites resolve most of the controversial biochemical data on the location of tetracycline. The interaction of edeine with the small subunit indicates its role in inhibiting initiation and shows its involvement with P-site tRNA. The location of the C-terminal domain of IF3, at the solvent side of the platform, sheds light on the formation of the initiation complex, and implies that the anti-association activity of IF3 is due to its influence on the conformational dynamics of the small ribosomal subunit.


Assuntos
Edeína/química , Iniciação Traducional da Cadeia Peptídica , Fatores de Iniciação de Peptídeos/química , Ribossomos/química , Tetraciclina/química , Thermus thermophilus , Sítios de Ligação , Cristalografia por Raios X , Fator de Iniciação 3 em Eucariotos , Modelos Moleculares , Inibidores da Síntese de Proteínas/química
13.
Methods ; 25(3): 292-302, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11860283

RESUMO

The cellular organelles translating the genetic code into proteins, the ribosomes, are large, asymmetric, flexible, and unstable ribonucleoprotein assemblies, hence they are difficult to crystallize. Despite two decades of intensive effort and thorough searches for suitable sources, so far only three crystal types have yielded high-resolution structures: two large subunits (from an archaean and from a mesophilic eubacterium) and one thermophilic small subunit. These structures have added to our understanding of decoding, have revealed dynamic aspects of the biosynthetic process, and have indicated the strategies adopted by ribosomes for interacting between themselves as well as with inhibitors, factors and substrates.


Assuntos
Cristalografia por Raios X/métodos , Ribossomos/química , Ribossomos/ultraestrutura , Archaea/química , Proteínas de Bactérias/química , Microscopia Eletrônica , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , RNA/química , Difração de Raios X
14.
Cell Mol Biol (Noisy-le-grand) ; 46(5): 871-82, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10976871

RESUMO

Within the framework of ribosomal crystallography, the small subunits are being analyzed, using crystals diffracting to 3 A resolution. The medium resolution electron density map of this subunit, obtained by multiple isomorphous replacement, show recognizable morphologies, strikingly similar to the functional active conformer of the small ribosomal subunit. It contains elongated dense features, traceable as RNA chains as well as globular regions into which the structures determined for isolated ribosomal proteins, or other known structural motifs were fitted. To facilitate unbiased map interpretation, metal clusters are being covalently attached either to the surface of the subunits or to DNA oligomers complementary to exposed ribosomal RNA. Two surface cysteines and the 3' end of the 16S ribosomal RNA have been localized. Targeting several additional RNA regions shed light on their relative exposure and confirmed previous studies concerning their functional relevance.


Assuntos
RNA Ribossômico/química , Ribossomos/química , Cristalografia por Raios X , Cisteína/química , DNA Complementar/química , Substâncias Macromoleculares , Modelos Moleculares , Conformação de Ácido Nucleico , Conformação Proteica , RNA Bacteriano/química , RNA Ribossômico 16S/química , Proteínas Ribossômicas/química , Eletricidade Estática , Thermus thermophilus/química
15.
Proc Natl Acad Sci U S A ; 97(16): 9258-63, 2000 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-10908670

RESUMO

Protozoan parasites of the genus Leishmania undergo a complex life cycle involving transmission by biting sand flies and replication within mammalian macrophage phagolysosomes. A major component of the Leishmania surface coat is the glycosylphosphatidylinositol (GPI)-anchored polysaccharide called lipophosphoglycan (LPG). LPG has been proposed to play many roles in the infectious cycle, including protection against complement and oxidants, serving as the major ligand for macrophage adhesion, and as a key factor mitigating host responses by deactivation of macrophage signaling pathways. However, all structural domains of LPG are shared by other major surface or secretory products, providing a biochemical redundancy that compromises the ability of in vitro tests to establish whether LPG itself is a virulence factor. To study truly lpg(-) parasites, we generated Leishmania major lacking the gene LPG1 [encoding a putative galactofuranosyl (Gal(f)) transferase] by targeted gene disruption. The lpg1(-) parasites lacked LPG but contained normal levels of related glycoconjugates and GPI-anchored proteins. Infections of susceptible mice and macrophages in vitro showed that these lpg(-) Leishmania were highly attenuated. Significantly and in contrast to previous LPG mutants, reintroduction of LPG1 into the lpg(-) parasites restored virulence. Thus, genetic approaches allow dissection of the roles of this complex family of interrelated parasite virulence factors, and definitively establish the role of LPG itself as a parasite virulence factor. Because the lpg1(-) mutant continue to synthesize bulk GPI-anchored Gal(f)-containing glycolipids other than LPG, a second pathway distinct from the Golgi-associated LPG synthetic compartment must exist.


Assuntos
Glicoconjugados/fisiologia , Glicoesfingolipídeos/fisiologia , Leishmania major/patogenicidade , Animais , Glicosilação , Glicosilfosfatidilinositóis/metabolismo , Leishmania major/metabolismo , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Virulência
16.
Rev Panam Salud Publica ; 7(2): 97-101, 2000 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-10748660

RESUMO

This study was intended to explore the conditions under which prenatal care is delivered in the border city of Tijuana, Baja California, Mexico, and to assess the possible associations between that care and neonatal results in terms of birthweight, health of the neonate, and prematurity. Seven hospitals serving persons from different socioeconomic strata were chosen, and between December 1993 and March 1994 interviews were conducted with 279 women who were in the first 24 to 48 hours of puerperium. During the interviews data were collected on socioeconomic level; the mothers' knowledge, attitudes, and practices concerning obstetric health; the mothers' perceptions of access to prenatal care; the quality of prenatal care visits (evaluated in terms of having blood and urine tested and weight and blood pressure measured); and the gynecological and obstetric and health history of the mother. A database was created using the SPSS statistics software package. Possible associations were explored, with prenatal care as the independent variable and various dependent variables, by means of contingency tables and a two-tailed Fisher's exact test. None of the neonates was premature, ill, or had a birthweight of < or = 2,500 g. For this reason it was decided to divide the variable corresponding to birthweight into two groupings, < or = 3,000 g and > 3,000 g. A significant (P < 0.00038) relationship was found between a lack of prenatal care and low birthweight. In addition, a lack of prenatal care was associated with: low family income; the mother's financial dependence on the father; the mother being in an unmarried relationship; little communication with the partner; having no medical insurance; an unwanted pregnancy; and giving delivery at the General Hospital. Out of the total sample of 279 women, 15 (5.4%) had received no prenatal care. None of these 15 women reported they had encountered difficulties that prevented them from obtaining prenatal care, but only 7 of those women answered that question. The prenatal care was of good quality in 190 of the cases (68%). Both the number and the timing of the prenatal visits were adequate in 142 of the cases (50%). The mother's having worked during pregnancy or before had a positive predictive value in terms of utilization of prenatal care services. Additional studies are needed to evaluate the possible relationship between domestic violence and the lack of prenatal care or a delay in seeking such care.


Assuntos
Cuidado Pré-Natal , Índice de Apgar , Peso ao Nascer , Interpretação Estatística de Dados , Emprego , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Seguro Saúde , Entrevistas como Assunto , México , Gravidez , Gravidez não Desejada , Fatores Socioeconômicos
17.
J Biomol Struct Dyn ; 17(4): 617-28, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10698100

RESUMO

Crystals of the small ribosomal subunit from Thermus thermophilus diffract to 3A and exhibit reasonable isomorphism and moderate resistance to irradiation. A 5A MIR map of this particle shows a similar shape to the part assigned to this particle within the cryo-EM reconstructions of the whole ribosome and contains regions interpretable either as RNA chains or as protein motifs. To assist phasing at higher resolution we introduced recombinant methods aimed at extensive selenation for MAD phasing. We are focusing on several ribosomal proteins that can be quantitatively detached by chemical means. These proteins can be modified and subsequently reconstituted into depleted ribosomal cores. They also can be used for binding heavy atoms, by incorporating chemically reactive binding sites, such as -SH groups, into them. In parallel we are co-crystallizing the ribosomal particles with tailor made ligands, such as antibiotics or cDNA to which heavy-atoms have been attached or diffuse the latter compounds into already formed crystals.


Assuntos
Proteínas de Bactérias/química , Proteínas Ribossômicas/química , Thermus thermophilus/química , Thermus thermophilus/genética , Proteínas de Bactérias/isolamento & purificação , Sítios de Ligação , Clonagem Molecular , Cristalografia por Raios X , DNA Complementar/metabolismo , Modelos Moleculares , Hibridização de Ácido Nucleico , Proteínas Ribossômicas/isolamento & purificação
18.
Rev. panam. salud pública ; 7(2): 97-101, feb. 2000.
Artigo em Espanhol | LILACS | ID: lil-264737

RESUMO

El presente estudio se diseñó con el fin de conocer las condiciones en las que se realiza el control prenatal en la ciudad fronteriza de Tijuana, Baja California, México y de estudiar las posibles asociaciones entre ese tipo de atención y el resultado neonatal en términos de peso al nacer, estado de salud del neonato y prematuridad. Se seleccionaron siete hospitales que atienden a personas de diferentes estratos socioeconómicos y entre diciembre de 1993 y marzo de 1994 se entrevistó en ellos a 279 mujeres que cursaban las primeras 24 a 48 horas del puerperio. En la entrevista se recogieron datos sobre nivel socioeconómico; conceptos, actitudes y prácticas de las madres respecto de la salud obstétrica; percepción materna de acceso a los servicios de atención prenatal; calidad de las consultas de control prenatal (evaluada según la realización de pruebas de sangre y orina y la medición de la tensión arterial y del peso); y antecedentes ginecobstétricos y de salud de la madre. Se elaboró una base de datos con el paquete estadístico SPSS y se exploraron posibles asociaciones entre la atención prenatal como variable independiente y las diferentes variables dependientes mediante tablas de contingencia y la prueba de Fisher de dos colas. No se encontraron neonatos prematuros, enfermos o con un peso al nacer <2 500g. Por este último motivo se optó por dicotomizar la variable correspondiente al peso al nacer en <3 000 g. y >3 000g. Se observó una asociación significativa (P<0,00038) entre la ausencia de control prenatal y un menor peso al nacer. La ausencia de control prenatal a su vez se asoció con bajos ingresos familiares; dependencia económica materna; convivencia de la madre en unión libre; poca comunicación con la pareja; falta de seguro médico; presencia de un embarazo no deseado; y haber acudido al Hospital General para la atención del parto. De la muestra total (n=15), 5,4 por ciento no recibió atención prenatal. Ninguna de las mujeres que no recibieron atención declaró haber enfrentado dificaultades que le impidieran el acceso, pero de las 15 solamente 7 contestaron la pregunta


Assuntos
Humanos , Feminino , Gravidez , Recém-Nascido , Peso ao Nascer , Recém-Nascido Prematuro , Nível de Saúde , Cuidado Pré-Natal , México
20.
Eur J Biochem ; 266(2): 524-32, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10561594

RESUMO

S17 is a primary rRNA-binding protein which has been implicated in ribosome assembly and translational fidelity. We describe the generation and biochemical characterization of an S17 minus ribosomal mutant, a ribosomal protein-lacking mutant obtained in Thermus thermophilus HB8. The S17 mutant was obtained by insertional inactivation of the target gene with the kanamycin adenyl transferase (kat) gene, making use of a Thermus-Escherichia shuttle vector and the natural ability of Thermus to transform. In the final construct used to transform Thermus cells, the S17 coding region was replaced with the kat gene cloned in-frame with the first three amino acids of S17. Hence, in vivo transcription of the kat gene was under the control of the ribosomal operon promoter. As in Escherichia coli, the Thermus S17 mutant exhibited a temperature-sensitive phenotype. Two-dimensional PAGE, Western blot, and ELISA confirmed the absence of S17 from the mutant ribosomes. Sucrose-gradient profiles of mutant cells showed a clear separation and normal proportions of 50S and 30S subunits and a normal ratio between them. In addition, the S17 mutant showed the presence of a 20S peak representing assembly-defective particles. The successful re-incorporation of protein S17 into the mutant ribosomes was demonstrated when reconstitution with isolated S17 was performed at 60 degrees C.


Assuntos
Ribossomos/metabolismo , Thermus thermophilus/metabolismo , Antibacterianos/farmacologia , Sequência de Bases , Western Blotting , Centrifugação com Gradiente de Concentração , Clonagem Molecular , DNA/metabolismo , Resistência a Medicamentos , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Escherichia coli/metabolismo , Canamicina/farmacologia , Dados de Sequência Molecular , Mutagênese , Mutação , Oligonucleotídeos/farmacologia , Fenótipo , Regiões Promotoras Genéticas , Proteínas Ribossômicas/química , Sacarose/farmacologia , Temperatura , Fatores de Tempo , Raios Ultravioleta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...