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1.
Nanotechnology ; 24(36): 365702, 2013 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-23942355

RESUMEN

Pairs of samples containing Ag nanoparticles (NPs) of different dimensions have been produced under the same conditions but on different substrates, namely standard glass slides and a thin layer of amorphous aluminum oxide (a-Al2O3) on-glass. Upon storage in ambient conditions (air and room temperature) the color of samples changed and a blue-shift and damping of the surface plasmon resonance was observed. The changes are weaker for the samples on-glass and tend to saturate after 12 months. In contrast, the changes for the samples on a-Al2O3 appear to be still progressing after 25 months. While x-ray photoelectron spectroscopy shows a slight sulfurization and negligible oxidation of the Ag for the on-glass samples upon 25 months aging, it shows that Ag is strongly oxidized for the on a-Al2O3 samples and sulfurization is negligible. Both optical and chemical results are consistent with the production of a shell at the expense of a reduction of the metal core dimensions, the latter being responsible for the blue-shift and related to the small (<10 nm initial diameter) of the NPs. The enhanced reactivity of the Ag NPs on the a-Al2O3 supports goes along with specific morphological changes of the Ag NPs and the observation of nitrogen.

2.
Nanotechnology ; 23(10): 105603, 2012 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-22362107

RESUMEN

This work reports on the optical and structural properties of nanostructured films formed by Ag nano-objects embedded in amorphous aluminium oxide (a-Al(2)O(3)) prepared by alternate pulsed laser deposition (PLD). The aim is to understand the importance of the energetic species involved in the PLD process for nanostructuring, i.e. for organizing nanoparticles (NPs) in layers or for self-assembling them into nanocolumns (NCls), all oriented perpendicular to the substrate. In order to change the kinetic energy of the species arriving at the substrate, we use a background gas during the deposition of the embedding a-Al(2)O(3) host. It was produced either in vacuum or in a gas pressure (helium and argon) while the metal NPs were always produced in vacuum. The formation of NPs or NCls is easily identified through the features of the surface plasmon resonances (SPR) in the extinction spectra and confirmed by electron microscopy. The results show that both the layer organization and self-assembling of the metal are prevented when the host is produced in a gas pressure. This result is discussed in terms of the deceleration of species arriving at the substrate in gas that reduces the metal sputtering by host species (by ≈58%) as well as the density of the host material (by ≥19%). These reductions promote the formation of large voids along which the metal easily diffuses, thus preventing organization and self-organisation, as well as an enhancement of the amount of metal that is deposited.

3.
HIV Med ; 10(3): 157-62, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19245537

RESUMEN

BACKGROUND: Short-term antiretroviral therapy (START) to prevent mother-to-child transmission (MTCT) is currently recommended for all HIV-1-infected pregnant women. The objective of this study was to assess the effect on CD4 cell counts and viral load dynamics the withdrawal of START after birth could generate. METHODS: This was a 5-year cohort study involving HIV-1-infected pregnant women who presented with CD4 counts >300 cells/microL and had received START to prevent MTCT. RESULTS: Seventy-five pregnancies were assessed. In 24 cases, there was a history of antiretroviral therapy prior to prophylaxis. The median baseline CD4 count was 573 cells/microL. In 75% of cases, prophylaxis was started after 26.6 weeks of gestation. The median CD4 cell count increase over baseline during prophylaxis was 24.5%. In only five cases did HIV-1 viral load remain detectable during prophylaxis. After START, CD4 cell counts did not drop significantly, and the HIV-1 viral load plateau was near the baseline level. The estimated mean time for CD4 count to fall below 300 cells/microL was 3.5 years and was directly associated with high baseline CD4 cell count, as well as with CD4 increase after prophylaxis, whereas it was negatively correlated with previous use of antiretroviral (ARV) drugs and persistence of detectable HIV-1 viral load during prophylaxis. CONCLUSIONS: A potent, well-tolerated prophylactic ARV regimen can improve CD4 cell counts during and after START. In women receiving such prophylaxis, there is a remarkable time interval for CD4 cell counts to drop to levels that indicate treatment.


Asunto(s)
Antirretrovirales/uso terapéutico , Linfocitos T CD4-Positivos/efectos de los fármacos , Infecciones por VIH/transmisión , VIH-1 , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Adulto , Recuento de Linfocito CD4 , Estudios de Cohortes , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Embarazo , Complicaciones Infecciosas del Embarazo/virología , ARN Viral/sangre , Factores de Riesgo , Carga Viral
4.
Braz J Med Biol Res ; 50(4): e5928, 2017 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-28380215

RESUMEN

Paracoccidioides brasiliensis and P. lutzii are fungi that cause paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in South America. For serological diagnosis, although 43-kDa glycoprotein (gp43) is regarded as highly specific for PCM, the occurrence of false negative reactions in sera from patients infected with P. lutzii suggests that preparation with only one antigen is not recommended. Heat shock proteins are feasible alternatives as a second antigen because they are often highly immunogenic. In this study, we evaluated the usefulness of recombinant 60-kDa heat shock protein from P. brasiliensis (rPbHsp60) for the serological diagnosis of PCM. Using western blotting assay, we observed that 77.3% of the sera from PCM patients were positive to rPbHsp60, with 90.9% positivity to recombinant gp43 (rgp43). More importantly, sera from healthy subjects had 27% positivity to rPbHsp60 and none to rgp43. When rPbHsp60 was used in ELISA, we did not observe significant differences between the reactions with sera from PCM patients and healthy subjects, while the difference was clearly evident when the antigen was rgp43. Furthermore, rPbHsp60 was recognized by sera from patients with histoplasmosis, aspergillosis, sporotrichosis or tuberculosis in an ELISA test. These results show that rPbHsp60 is not a good antigen for PCM diagnosis.


Asunto(s)
Antígenos Fúngicos/sangre , Chaperonina 60/sangre , Proteínas Fúngicas/sangre , Paracoccidioides/inmunología , Paracoccidioidomicosis/diagnóstico , Pruebas Serológicas/métodos , Western Blotting , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Humanos , Paracoccidioidomicosis/sangre , Proteínas Recombinantes/sangre , Valores de Referencia , Reproducibilidad de los Resultados , Estadísticas no Paramétricas
5.
Opt Express ; 14(19): 8765-71, 2006 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-19529258

RESUMEN

We report the use of laser ablation of metal targets onto a glass substrate as a way of producing waveguiding devices. In the geometry employed, the nanosecond pulses used for the ablation pass through the glass substrate, and are focused on the metal surface, which is located in close proximity with the substrate. We present measurements of the refractive index profile obtained with this technique, and present a discussion of the physical mechanisms that produce the profiles measured.

6.
Genet Vaccines Ther ; 4: 1, 2006 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-16445866

RESUMEN

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system.

7.
Int J Infect Dis ; 10(1): 56-60, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16326126

RESUMEN

INTRODUCTION: Klebsiella pneumoniae is of high prevalence in hospital infections, mainly in bloodstream infections (BSI), and some produce extended-spectrum beta-lactamase (ESBL). For hospitals with a high prevalence of strains producing this enzyme, there is no reference material to show whether the use of the E-test method for their detection, which can be quite expensive, is actually required. OBJECTIVE: To evaluate the cost-benefit of the disk diffusion and E-test methods for the detection of ESBL-producing K. pneumoniae strains in hospitals where a high prevalence of this resistance mechanism in BSI is found. METHODS: One hundred and eight patients with K. pneumoniae BSI were evaluated retrospectively. ESBL-producing strains were identified by the disk diffusion method and by the E-test method. We estimated the costs of both diagnostic methods based on antimicrobial therapy adequacy. RESULTS: Fifty-two percent of K. pneumoniae infections were due to ESBL-producing strains. The disk diffusion method yielded a positive predictive value (PPV) of 94.7% (95% CI: 88.9-100%) and a negative predictive value (NPV) of 96.1% (CI 95%: 90.8-101.4%) in relation to the E-test. We evaluated cost-effectiveness, i.e., we analyzed the cost of both E-test and disk diffusion methods with carbapenem and cephalosporins, and found that the use of the disk diffusion method accounts for approximately US$3300. CONCLUSIONS: In hospitals with a high prevalence of ESBL-producing strains, the disk diffusion method can be used to detect ESBL-producing K. pneumoniae without compromising the clinical progression of patients with BSI. The E-test showed higher accuracy but this method was more expensive than the disk diffusion method. However, the use of the E-test method was demonstrated to be more cost-effective, as we evaluated cost based on antimicrobial therapy adequacy.


Asunto(s)
Bacteriemia/economía , Infecciones por Klebsiella/economía , Klebsiella pneumoniae/enzimología , Centros Médicos Académicos , Adulto , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Brasil , Carbapenémicos/farmacología , Carbapenémicos/uso terapéutico , Cefalosporinas/farmacología , Cefalosporinas/uso terapéutico , Estudios de Cohortes , Costos y Análisis de Costo , Hospitales , Humanos , Infecciones por Klebsiella/diagnóstico , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estudios Retrospectivos , Resultado del Tratamiento , beta-Lactamasas/metabolismo
8.
Int J Gynaecol Obstet ; 95(2): 179-84, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16997304

RESUMEN

OBJECTIVE: To evaluate the use of community health agents (CHAs) to instruct women living in poor rural areas in obtaining self-collected cervical samples and compare the high-risk HPV (hrHPV) hybrid capture (HC) results obtained to those for gynecologist-collected samples. METHODS: After a one-day training, CHAs visited sexually active women, instructing each in the use of collection brush and the Universal Collection Medium tube. One week thereafter, a gynecologist collected cervical samples from, and performed colposcopies on, the same women. A single reference lab performed all HCs. RESULTS: 878 women (Age: 15-69 years) participated. Among self-collected samples, hrHPV prevalence was 33.9% (95% CI: 30.8%-37%), compared with 28.6% (95% CI: 27%-30%) among gynecologist-collected samples. However, 9.3% of the patients were HPV HC II-positive in the self-collected sample and HPV HC II-negative in the gynecologist-collected samples (95% CI: 7.38%-11.22%), whereas 4% tested positive in gynecologist-collected samples and negative in self-collected samples (95% CI: 2.7%-5.3%) (P<0.01; kappa=0.7). Of 9 cases of histologically-confirmed, high-grade squamous intraepithelial lesion, self-collected and provider-collected samples missed one each. CONCLUSION: Self-collected vaginal sampling could be made an additional CHA function under existing program conditions, improving access to cervical cancer screening in poor rural settings.


Asunto(s)
Cuello del Útero/virología , Infecciones por Papillomavirus/diagnóstico , Autocuidado/métodos , Manejo de Especímenes , Displasia del Cuello del Útero/virología , Neoplasias del Cuello Uterino/virología , Adolescente , Adulto , Anciano , Brasil , Servicios de Salud Comunitaria , Reacciones Falso Negativas , Femenino , Humanos , Tamizaje Masivo/métodos , Persona de Mediana Edad , Infecciones por Papillomavirus/complicaciones , Educación del Paciente como Asunto , Pobreza , Población Rural , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/diagnóstico , Displasia del Cuello del Útero/diagnóstico
9.
Braz J Infect Dis ; 10(4): 269-73, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17293910

RESUMEN

Influenza vaccination of elderly people is efficacious and cost effective for the prevention of influenza and its complications. Some studies have pointed out low immunogenicity in this group. Health status has been poorly investigated as a risk factor that may influence the immune response to influenza vaccine. We established an immunization response study of a highly-matched elderly population in a nursing home. One-hundred-twenty subjects of Ashkenazian origin had their vaccine-induced antibody response assessed. Good response was obtained in 30.8% (37/120), and 31.7% (38/120) did not react. A lack of good response was found to be associated with dementia (P=0.016) in a multivariate analysis. In addition to dementia, malnutrition was frequently observed among poor responders, suggesting that these factors should be considered in vaccination studies. Chemoprophylaxis in addition to vaccination for elderly presenting dementia should be considered, particularly for those people living nursing homes.


Asunto(s)
Virus de la Influenza A/inmunología , Virus de la Influenza B/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/prevención & control , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Técnica de Inmunoensayo de Enzimas Multiplicadas , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Gripe Humana/inmunología , Masculino , Factores de Riesgo
10.
Braz J Infect Dis ; 10(4): 259-63, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17293908

RESUMEN

It is currently recommended that antiretroviral prophylaxis to prevent mother-to-child transmission (MTCT) of HIV be initiated at 14 weeks of gestation. However, the relevance of early-gestation HIV viral load level for intrauterine MTCT is unknown. The objective of this study was to determine the relationship between prenatal maternal viral load and intrauterine MTCT. Records of HIV-infected pregnant women in two centers in Brazil, from 1999 to 2004 were analyzed. Three pregnancy periods were considered: earlier than 14 weeks, 14 to 27 6/7 weeks, and 28 weeks of gestation or more. Peripartum HIV exposure was also computed. Maximum viral load in each period was the measure of HIV exposure. Four hundred fifty-seven HIV-infected pregnant women were evaluated, but 53 were excluded. The MTCT rate was 0.49% (2/404-95% confidence interval (CI95) = 0.14-1.79%). Newborns were not breast-fed. Median viral load for the earlier-than-14-week period was 9,900 copies/mL (P25-75 1,000-50,775 copies/mL), 8,350 copies/mL (P25-75 707-42,000 copies/mL) for the 14 to 27 6/7-week period, and 435 copies/mL (P25-75 90-7,775 copies/mL) after the 28-week period. The peripartum median viral load was 400 copies/mL (P25-75 80-500 copies/mL). MTCT in mothers with VL > 1,000 copies/mL during the first 14 weeks (0.67%, 2/298) was not different from those with VL =1,000 copies/mL (0.0%, 0/96, P=1). Analogously, in the 14 to 27 6/7-week period, MTCT was similar in groups with VL higher (0.68%, 2/292) or lower (0%, 0/106) than 1,000 copies/mL (P=1). Regarding VL >1,000 copies/mL at 28-weeks-or-later and at peripartum periods, MTCT rates were 1.15% (2/173, P = 0.18) and 2.8% (2/71, P = 0.03), respectively. Intrauterine transmission does not seem to be influenced by HIV viremia during the first 28 weeks of pregnancy.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/prevención & control , VIH-1 , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Complicaciones Infecciosas del Embarazo/prevención & control , Carga Viral , Adolescente , Adulto , Terapia Antirretroviral Altamente Activa , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/transmisión , Humanos , Recién Nacido , Persona de Mediana Edad , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/virología , Segundo Trimestre del Embarazo , Estudios Retrospectivos
11.
Occup Environ Med ; 62(6): 381-9, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15901885

RESUMEN

AIMS: To investigate the consequences of improvement in the workplace environment over six decades (1940-96) in asbestos miners and millers from a developing country (Brazil). METHODS: A total of 3634 Brazilian workers with at least one year of exposure completed a respiratory symptoms questionnaire, chest radiography, and a spirometric evaluation. The study population was separated into three groups whose working conditions improved over time: group I (1940-66, n = 180), group II (1967-76, n = 1317), and group III (1977-96, n = 2137). RESULTS: Respiratory symptoms were significantly related to spirometric abnormalities, smoking, and latency time. Breathlessness, in particular, was also associated with age, pleural abnormality and increased cumulative exposure to asbestos fibres. The odds ratios (OR) for parenchymal and/or non-malignant pleural disease were significantly lower in groups II and III compared to group I subjects (0.29 (0.12-0.69) and 0.19 (0.08-0.45), respectively), independent of age and smoking status. Similar results were found when groups were compared at equivalent latency times (groups I v II: 30-45 years; groups II v III: 20-25 years). Ageing, dyspnoea, past and current smoking, and radiographic abnormalities were associated with ventilatory impairment. Lower spirometric values were found in groups I and II compared to group III: lung function values were also lower in higher quartiles of latency and of cumulative exposure in these subjects. CONCLUSIONS: Progressive improvement in occupational hygiene in a developing country is likely to reduce the risk of non-malignant consequences of dust inhalation in asbestos miners and millers.


Asunto(s)
Amianto/toxicidad , Enfermedades Pulmonares/etiología , Minería/tendencias , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Adulto , Anciano , Amianto/administración & dosificación , Amianto/análisis , Brasil/epidemiología , Países en Desarrollo , Humanos , Exposición por Inhalación/efectos adversos , Exposición por Inhalación/análisis , Modelos Logísticos , Enfermedades Pulmonares/diagnóstico por imagen , Enfermedades Pulmonares/epidemiología , Masculino , Persona de Mediana Edad , Minería/normas , Enfermedades Profesionales/diagnóstico por imagen , Enfermedades Profesionales/epidemiología , Exposición Profesional/análisis , Salud Laboral/estadística & datos numéricos , Radiografía , Pruebas de Función Respiratoria , Mecánica Respiratoria , Estudios Retrospectivos , Fumar/efectos adversos , Espirometría
12.
J Hum Hypertens ; 29(7): 417-23, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25500900

RESUMEN

The aim of this study was to ascertain the relationship between social network and the appearance of mortality (cardiovascular events (CVEs)) in patients with arterial hypertension (AHT). This is a cohort study of 236 patients with a 9-year follow-up. Measurements included age, sex, blood pressure (BP), diabetes, hypercholesterolemia, marital status, social network, social support, stage of family life cycle (FLC), mortality and CVEs. Patients with a low social network registered higher global mortality (hazards ratio (HR) 2.6 (95% confidence interval (CI) 1.3; 5.5)) as did the oldest patients (HR 5.6 (1.9; 16.8)), men (HR 3.5 (95% CI 1.3; 9.3)) and subjects in the last FLC stages (HR 4.3 (95% CI 1.3;14.1)). Patients with low social support registered higher cardiovascular mortality (HR 2.6 (95% CI 1.1; 6.1)) as did the oldest patients (HR 12.4 (95% CI 2.8; 55.2)) and those with diabetes (HR 3.00 (95% CI 1.2; 7.6)). Patients with a low social network registered more CVEs (HR 2.1 (95% CI 1.1; 4.1)) than patients with an adequate network, as did the oldest patients (HR 3.1 (95% CI 1.4; 6.9)), subjects who presented with a higher grade of severity of AHT (HR 2.7 (1.3; 5.5)) and those in the last FLC stages (HR 2.5 (95% CI 1.0; 6.2)). A low social network is associated with mortality and the appearance of CVEs in patients with AHT. Low functional social support is associated with the appearance of cardiovascular mortality.


Asunto(s)
Hipertensión/mortalidad , Apoyo Social , Adulto , Anciano , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Braz J Med Biol Res ; 48(12): 1095-100, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26397973

RESUMEN

In DNA vaccines, the gene of interest is cloned into a bacterial plasmid that is engineered to induce protein production for long periods in eukaryotic cells. Previous research has shown that the intramuscular immunization of BALB/c mice with a naked plasmid DNA fragment encoding the Mycobacterium leprae 65-kDa heat-shock protein (pcDNA3-Hsp65) induces protection against M. tuberculosis challenge. A key stage in the protective immune response after immunization is the generation of memory T cells. Previously, we have shown that B cells capture plasmid DNA-Hsp65 and thereby modulate the formation of CD8+ memory T cells after M. tuberculosis challenge in mice. Therefore, clarifying how B cells act as part of the protective immune response after DNA immunization is important for the development of more-effective vaccines. The aim of this study was to investigate the mechanisms by which B cells modulate memory T cells after DNA-Hsp65 immunization. C57BL/6 and BKO mice were injected three times, at 15-day intervals, with 100 µg naked pcDNA-Hsp65 per mouse. Thirty days after immunization, the percentages of effector memory T (TEM) cells (CD4+ and CD8+/CD44high/CD62Llow) and memory CD8+ T cells (CD8+/CD44high/CD62Llow/CD127+) were measured with flow cytometry. Interferon γ, interleukin 12 (IL-12), and IL-10 mRNAs were also quantified in whole spleen cells and purified B cells (CD43-) with real-time qPCR. Our data suggest that a B-cell subpopulation expressing IL-10 downregulated proinflammatory cytokine expression in the spleen, increasing the survival of CD4+ TEM cells and CD8+ TEM/CD127+ cells.


Asunto(s)
Linfocitos B/inmunología , Proteínas de Choque Térmico/inmunología , Inmunomodulación/genética , Interleucina-10/genética , ARN Mensajero/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Linfocitos B/metabolismo , Citometría de Flujo , Expresión Génica/genética , Proteínas de Choque Térmico/uso terapéutico , Memoria Inmunológica/fisiología , Inmunofenotipificación/clasificación , Mediadores de Inflamación/análisis , Interferón gamma/análisis , Interleucina-10/inmunología , Interleucina-12/análisis , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Bazo/citología , Bazo/inmunología , Subgrupos de Linfocitos T/clasificación , Vacunas de ADN/inmunología , Vacunas de ADN/uso terapéutico
14.
Int J Parasitol ; 32(14): 1747-54, 2002 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-12464421

RESUMEN

We demonstrate here that a mannose-binding protein from Schistosoma mansoni, termed Sm60, was recovered in the mannose-eluted fraction (Man(+)) upon affinity chromatography on immobilised mannose of the soluble antigen fraction from adult worm tegument and cercariae. Sm60 was detected in the Man(+) fraction as a prominent doublet with an apparent molecular mass of 60-66 kDa by SDS-PAGE and appeared as a single band with a pI of approximately 6.9 by isoelectrofocusing. Sm60 was also detected in preparations of schistosomula extract and soluble egg antigens using a mouse polyclonal anti-Sm60 serum on immunoblotting assay. This antiserum demonstrated that Sm60 was localised on the tegument of S. mansoni adult worm. In order to determine the role of Sm60 in host-parasite interactions, we showed that Sm60 induced in vitro migration of human neutrophil in a dose-dependent manner and in vitro mast cell degranulation. Sm60 triggered these activities through its carbohydrate-binding site, since these activities were selectively inhibited by 0.2 M D-mannose, but not by 0.2 M D-galactose. Furthermore, Sm60 induced in vivo neutrophil migration. In contrast, mast cell-depleted rats presented a significant reduction of the neutrophil migration induced by Sm60 as compared with non-depleted controls. These data suggest that in vivo neutrophil migration induced by Sm60 is modulated by mast cell-dependent mechanisms. Sm60 might play a key role in the host-parasite interaction, and its characterization opens perspective to examine the role of this molecule in the biology of S. mansoni.


Asunto(s)
Proteínas del Helminto/aislamiento & purificación , Lectina de Unión a Manosa/aislamiento & purificación , Schistosoma mansoni/química , Animales , Degranulación de la Célula/efectos de los fármacos , Quimiotaxis de Leucocito/efectos de los fármacos , Cromatografía de Afinidad , Relación Dosis-Respuesta a Droga , Técnica del Anticuerpo Fluorescente Indirecta , Proteínas del Helminto/metabolismo , Proteínas del Helminto/farmacología , Interacciones Huésped-Parásitos , Masculino , Lectina de Unión a Manosa/metabolismo , Lectina de Unión a Manosa/farmacología , Mastocitos/fisiología , Ratones , Ratones Endogámicos BALB C , Ratas , Ratas Wistar
15.
J Clin Epidemiol ; 44 Suppl 2: 21S-28S, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-2045837

RESUMEN

Brazil is typical of many developing countries in its struggle to provide basic healthcare for its citizens in face of national economic instability. Since pharmaceuticals represent a major component of modern healthcare, their production, regulation and use become an area of concern. It appears that any change in the current production patterns will require a major commitment from governments, understanding external economic pressures. There are pros and cons in a policy directed towards pharmaceutical self-sufficiency. Aside from production, efforts directed towards extending access to essential drugs and improving the appropriateness of use, would appear to be warranted.


Asunto(s)
Antibacterianos , Industria Farmacéutica/organización & administración , Brasil , Países en Desarrollo , Industria Farmacéutica/economía , Industria Farmacéutica/tendencias , Humanos , Comercialización de los Servicios de Salud
16.
Infect Control Hosp Epidemiol ; 19(1): 32-7, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9475347

RESUMEN

OBJECTIVE: To analyze risk factors for, and the role of methicillin resistance in, mortality in Staphylococcus aureus bacteremia. DESIGN: Nested case-control study. SETTING: General teaching hospital with a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains, in São Paulo, Brazil. PATIENTS: 136 patients over 14 years old with documented S aureus bacteremia. Those who died were compared with those who survived at least 14 days. RESULTS: Mortality within 14 days of bacteremia was 39% (53/136). Mean age was 47 years. Hospital-acquired bacteremia represented 86% (117/136) of episodes. In 26% (35/136), infection was related to an intravascular catheter and in 13% (17/136) to the respiratory tract. Septic shock occurred in 22% (30/136) of cases. MRSA was isolated in 66% (90/136). Multivariate analysis identified three variables that were significantly and independently associated with mortality: site of entry (lung, odds ratio [OR], 17.0; unknown, OR, 12.3; others, OR, 6.6); occurrence of shock (OR, 8.9), and resistance of S aureus to methicillin (OR, 4.2). CONCLUSION: Our study shows that S aureus bacteremia has a high mortality, especially when the lung is the source of infection and when shock develops; resistance to methicillin may be another risk factor for poor outcome.


Asunto(s)
Bacteriemia/microbiología , Bacteriemia/mortalidad , Infección Hospitalaria/mortalidad , Mortalidad Hospitalaria , Infecciones Estafilocócicas/mortalidad , Anciano , Brasil/epidemiología , Femenino , Hospitales con más de 500 Camas , Humanos , Enfermedades Pulmonares/microbiología , Masculino , Resistencia a la Meticilina , Persona de Mediana Edad , Prevalencia , Factores de Riesgo
17.
Diagn Microbiol Infect Dis ; 24(1): 1-6, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8988756

RESUMEN

The pneumococcus is a leading cause of serious bacterial infection worldwide. Given the difficulties with available assays for the diagnosis of invasive nonmeningitic pneumococcal infection, we evaluated monovalent slide latex agglutination reagents among patients with blood culture-confirmed pneumococcal infection and control patients in Baltimore, Maryland, USA; São Paulo, Brazil; and Cairo, Egypt. Among 50 patients with invasive nonmeningitic pneumococcal infection, 23 had a positive urine test for a sensitivity of 46% (95% confidence intervals of 32% and 61%). Among 39 healthy children, 36 had a negative assay, for a specificity of 92% (95% confidence intervals of 78% and 98%). Among 80 children with pneumonia without a positive blood culture for Streptococcus pneumoniae, the specificity was 88% (95% confidence intervals of 78% and 94%). Although the assay was fairly specific, the positive predictive value using optimistic assumptions was only 73%-83%. This study suggests that this assay has a sensitivity and positive predictive value that may limit its value in some settings.


Asunto(s)
Pruebas de Fijación de Látex/métodos , Infecciones Neumocócicas/diagnóstico , Streptococcus pneumoniae , Preescolar , Humanos , Lactante , Infecciones Neumocócicas/inmunología , Infecciones Neumocócicas/orina , Neumonía Neumocócica/diagnóstico , Neumonía Neumocócica/microbiología , Neumonía Neumocócica/orina , Control de Calidad , Sensibilidad y Especificidad , Streptococcus pneumoniae/inmunología , Streptococcus pneumoniae/aislamiento & purificación
18.
FEMS Microbiol Lett ; 197(1): 11-8, 2001 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-11287139

RESUMEN

How the immune system kills Mycobacterium tuberculosis is still a puzzle. The classical picture of killing due to phagocytosis by activated macrophages may be only partly correct. Based on recent evidence, we express here the view that cytotoxic T lymphocytes also make an important contribution and suggest that DNA vaccines might be a good way to enhance this.


Asunto(s)
Proteínas Bacterianas , Chaperoninas/inmunología , Mycobacterium tuberculosis/inmunología , Linfocitos T Citotóxicos/inmunología , Tuberculosis/prevención & control , Vacunas de ADN/inmunología , Animales , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/inmunología , Chaperonina 60 , Chaperoninas/genética , Humanos , Activación de Macrófagos/inmunología , Ratones , Mycobacterium tuberculosis/genética , Ratas , Ratas Endogámicas Lew , Tuberculosis/inmunología , Tuberculosis/microbiología , Vacunas de ADN/administración & dosificación
19.
Clin Microbiol Infect ; 6(1): 34-7, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11168034

RESUMEN

OBJECTIVES: To study the influence of soluble tumour necrosis factor (TNF) receptors (sTNFR) on bioactivity and immunoreactivity of TNF-alpha in patients with visceral leishmaniasis (Kala-azar) and to examine the association between circulating levels of sTNFR type I and type II with clinical manifestations of the disease. METHODS: Ten patients with Kala-azar were enrolled. Plasma samples for TNF-alpha and sTNFR were obtained on days 0, 7 and 21-28 of antimonial therapy. Bioactivity of TNF-alpha was measured by cytotoxicity to L-929 cells and immunoreactivity by enzyme-linked immunosorbent assay (ELISA). sTNFR-I and sTNFR-II were measured by ELISA. RESULTS: Measured by ELISA, TNF-alpha was detected at baseline in all patients (range from 22.3 to 163 pg/mL) and showed a linear decline over time on therapy (r = -0.49, P = 0.007). In contrast, when measured by cytotoxicity assay, TNF-alpha was detected in only one patient at baseline (193 pg/mL) and in four patients at the end of therapy (38.7, 95, 133 and 232 pg/mL) and there was no linear association between TNF-alpha and duration of therapy (r = -0.18, P = 0.45). sTNFR-I and sTNFR-II were detected in all patients before therapy. There was a strong positive correlation between plasma concentrations of sTNFR-I and sTNFR-II (r = 0.8, P = 0.006). Levels of sTNFR-I and sTNFR-II declined exponentially with time on therapy. CONCLUSIONS: We concluded that sTNFR-I and sTNFR-II are related to disease activity in patients with Kala-azar and that these circulating receptors may interfere with the biological activity of TNF-alpha in patients with Kala-azar.


Asunto(s)
Leishmania donovani/inmunología , Leishmaniasis Visceral/inmunología , Receptores del Factor de Necrosis Tumoral/análisis , Factor de Necrosis Tumoral alfa/análisis , Animales , Antiprotozoarios/uso terapéutico , Ensayo de Inmunoadsorción Enzimática , Humanos , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/tratamiento farmacológico
20.
Am J Ophthalmol ; 131(3): 378-9, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11239874

RESUMEN

PURPOSE: To report the outcome of microsporidial keratoconjunctivitis in a patient with acquired immunodeficiency syndrome (AIDS) after highly active antiretroviral therapy without any specific treatment for microsporidiosis. METHODS: Case report. A 42-year-old woman diagnosed with AIDS and severe immunodepression (CD4+ of 9 cells/mm(3) and viral load of 460,000/mm(3)), antiretroviral naive, presented with cerebral toxoplasmosis and microsporidial keratoconjunctivitis in the right eye documented by conjunctival scraping and electron microscopy. RESULTS: The patient was treated with a combination of indinavir, stavudine, and lamivudine, besides sulfadiazine and pyrimethamine. No specific treatment for the microsporidial keratoconjunctivitis was attempted. One month later, the keratoconjunctivitis had disappeared. CONCLUSION: This case suggests that microsporidial keratoconjunctivitis in the setting of AIDS and severe immunodepression can be effectively managed with highly active antiretroviral therapy alone.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Infecciones Parasitarias del Ojo/tratamiento farmacológico , Queratoconjuntivitis/tratamiento farmacológico , Microsporidios/aislamiento & purificación , Microsporidiosis/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/parasitología , Adulto , Animales , Quimioterapia Combinada , Infecciones Parasitarias del Ojo/parasitología , Femenino , Humanos , Indinavir/uso terapéutico , Queratoconjuntivitis/parasitología , Lamivudine/uso terapéutico , Microsporidiosis/parasitología , Estavudina/uso terapéutico , Agudeza Visual
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