RESUMO
BACKGROUND: It is unclear whether optimal immunological recovery reduces the risk of tuberculosis (TB) in human immunodeficiency virus (HIV) infected patients receiving antiretroviral therapy (ART), in whom it is still significantly higher than in the general population. METHODS: Retrospective cohort study in ART-treated patients without a previous diagnosis of TB. TB was microbiologically proven. Multivariate analyses were performed to identify risk factors associated with TB. RESULTS: This study included 1824 patients; the median follow-up was 473 days. The median CD4 count was 207 cells/µl (90-363.8); 339 (18.6%) were tuberculin skin test positive. Increased CD4 count gain after ART initiation was a protective factor against active TB (per each 100 cells/µl increase, OR 0.683, 95%CI 0.522-0.894). Maximal protection was observed in patients reaching increments ⩾150 cells/µl after 12 months of ART (OR 0.29, 95%CI 0.11-0.8) or ⩾300 cells/µl after 24 months (OR 0.73, 95%CI 0.71-0.75). There was no association between achieving HIV RNA <50 copies/ml and risk of active TB (OR 1.43, 95%CI 0.68-2.49). CONCLUSIONS: The risk of TB in patients starting ART is reduced among those with better immunological response, and is unrelated to the virological response. Our results emphasise the need for adjunctive strategies in immunological non-responders to minimise any residual risk of TB.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/prevenção & controle , Fármacos Anti-HIV/uso terapêutico , Coinfecção , Infecções por HIV/tratamento farmacológico , Tuberculose/prevenção & controle , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/imunologia , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Adulto , Contagem de Linfócito CD4 , Distribuição de Qui-Quadrado , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/imunologia , Humanos , Hospedeiro Imunocomprometido , Incidência , Modelos Logísticos , Masculino , Análise Multivariada , Razão de Chances , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Espanha/epidemiologia , Fatores de Tempo , Resultado do Tratamento , Teste Tuberculínico , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/imunologia , Tuberculose/microbiologia , Carga ViralRESUMO
The hyper-arid core of the Atacama Desert (Chile) is the driest place on Earth and is considered a close analogue to the extremely arid conditions on the surface of Mars. Microbial life is very rare in soils of this hyper-arid region, and autotrophic micro-organisms are virtually absent. Instead, photosynthetic micro-organisms have successfully colonized the interior of halite crusts, which are widespread in the Atacama Desert. These endoevaporitic colonies are an example of life that has adapted to the extreme dryness by colonizing the interior of rocks that provide enhanced moisture conditions. As such, these colonies represent a novel example of potential life on Mars. Here, we present non-destructive Raman spectroscopical identification of these colonies and their organic remnants. Spectral signatures revealed the presence of UV-protective biomolecules as well as light-harvesting pigments pointing to photosynthetic activity. Compounds of biogenic origin identified within these rocks differed depending on the origins of specimens from particular areas in the desert, with differing environmental conditions. Our results also demonstrate the capability of Raman spectroscopy to identify biomarkers within rocks that have a strong astrobiological potential.
Assuntos
Clima Desértico , Microbiologia , Minerais , Cloreto de Sódio , Análise Espectral Raman , Exobiologia , América do Sul , Difração de Raios XRESUMO
Heterochromatin patterns were analyzed in the genus Ctenomys from Uruguay which exhibits high karyotype variability. Different amounts and localizations of heterochromatin were observed in species and populations analyzed. While species as C. rionegrensis presented heterochromatic arms in all the chromosomes of the karyotype, other species like C. torquatus showed only few chromosomes with pericentric heterochromatin. At the pachytene stage, bivalents merge in densely stained chromocenters. We detected in these chromocenters the typical highly repeated DNA of this genus after in situ hybridization, the M31 chromodomain through immunofluorescence as well as dense Giemsa staining after C-banding. In species that present low amounts of heterochromatin, only 1 or 2 chromocenters were observed in which bivalents merge as observed in C. rionegrensis. After BRCA1 immunodetection we observed in early pachytene cells positive spots located over heterochromatic chromocenters that strongly suggest heterochromatic DNA repair. Mechanical stress mainly due to increasing chromatin compactness before metaphase I might be a mechanism to spread heterochromatin between different chromosomes within a karyotype.
Assuntos
Cromossomos de Mamíferos/metabolismo , Heterocromatina/metabolismo , Roedores/genética , Animais , Proteína BRCA1/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Cariotipagem , Estágio Paquíteno , UruguaiRESUMO
Cancers of the upper aerodigestive tract [(UADT): oral cavity, pharynx, larynx and oesophagus] have high incidence rates in some parts of South America. Alterations in the TP53 gene are common in these cancers. In our study, we have estimated the prevalence and patterns of TP53 mutations (exons 4-10) in 236 UADT tumours from South America in relation to lifestyle risk factors, such as tobacco smoking and alcohol drinking. Moreover, we have conducted a pilot study of EGFR mutations (exons 18-21) in 45 tumours from the same population. TP53 mutation prevalence was high: 59% of tumours were found to carry mutant TP53. We found an association between TP53 mutations and tobacco smoking and alcohol drinking. The mutation rate increased from 38% in never-smokers to 66% in current smokers (P-value for trend = 0.09). G:C>T:A transversions were found only in smokers (15%). Alcohol drinkers carried more G:C>A:T transitions (P = 0.08). Non-exposed individuals were more probable to carry G:C>A:T transitions at CpG sites (P = 0.01 for never-smokers and P < 0.001 for never-drinkers). EGFR mutations were found in 4% of cases. Inactivation of TP53 by mutations is a crucial molecular event in the UADT carcinogenesis and it is closely related to exposure to lifestyle risk factors. EGFR mutations do not appear to be a common event in UADT carcinogenesis in this population.
Assuntos
Receptores ErbB/genética , Neoplasias Esofágicas/epidemiologia , Genes p53 , Neoplasias de Cabeça e Pescoço/epidemiologia , Estilo de Vida , Adulto , Idoso , Estudos de Casos e Controles , Cocarcinogênese , Neoplasias Esofágicas/genética , Feminino , Neoplasias de Cabeça e Pescoço/genética , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fatores de Risco , América do Sul/epidemiologiaRESUMO
Raman spectra have been obtained for extremophiles from several geological environments; selected examples have been taken from hot and cold deserts comprising psychrophiles, thermophiles and halophiles. The purpose of this study is the assessment of the effect of the wavelength of the laser excitation on the ability to determine unique information from the Raman spectra about the specificity of detection of biomolecules produced as a result of the survival strategies adopted by organisms in extreme terrestrial environments. It was concluded that whereas FT-Raman spectroscopy at 1064 nm gave good quality results the time required to record the data was relatively large compared with other wavelengths of excitation but that better access to the CH stretching region for organic molecules was given. Shorter wavelength excitation of biomolecules in the blue-green regions of the visible spectrum using a conventional dispersive spectrometer was more rapid but very dependent upon the type of chemical compound being studied; most relevant biomolecules fluoresced at these wavelengths but carotenoids exhibited a resonance effect which resulted in an improved detection capability. Minerals and geological materials, in contrast, were best studied at these visible wavelengths. In general, the best compromise system for the excitation of the Raman spectra of both geological and biological materials was provided using a 785 nm laser coupled with a dispersive spectrometer, especially for accessing the 1800-200 cm(-1) wavenumber shift region where much of the definitive analytical information resides. This work will have conclusions relevant to the use of miniaturised Raman spectrometers for the detection of biomolecules in extraterrestrial planetary exploration.
Assuntos
Biofilmes , Cianobactérias/química , Meio Ambiente , Halobacteriales/química , Líquens/química , Análise Espectral Raman/métodos , Regiões Antárticas , Regiões Árticas , Chile , Clima Frio , Clima DesérticoRESUMO
Spinal cord metastases are an uncommon secondary location of a malignant neoplasm. They are rarely diagnosed during life and when that is the case, it is in the clinical setting of a disseminated cancer and very seldom as the first clinical manifestation. We report two patients, with no previous disease, who developed a progressive myelopathy. An intramedullary spinal cord tumor was diagnosed, based on the clinical picture and imaging studies. They were operated and biopsies showed spinal cord metastases whose primary tumor was a lung neoplasm. We discuss the clinical features in these patients, the diagnosis of progressive myelopathy in cancer patients, treatment and prognosis of this unusual secondary cancer location.
Assuntos
Adenocarcinoma de Células Claras/secundário , Neoplasias Pulmonares/patologia , Neoplasias da Medula Espinal/secundário , Adenocarcinoma de Células Claras/diagnóstico por imagem , Adulto , Evolução Fatal , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia , Neoplasias da Medula Espinal/diagnóstico por imagemRESUMO
BACKGROUND: Cerebral metabolic monitoring in critical neurological patients allows the assessment of neuronal tissue response to injury and to plan the best therapy to correct each critical brain situation. AIM: To evaluate the usefulness of cerebral metabolic monitoring in patients with acute cerebral injury. PATIENTS AND METHODS: A retrospective analysis of 29 patients with acute brain injury, in whom a catheter was located in the bulb of the jugular vein to perform a cerebral metabolic monitoring. These patients were compared with others that were not subjected to this monitoring. The evolution at six months of follow up was assessed using the Glasgow outcome score, considering a favorable evolution when this score was 4 or greater. RESULTS: Patients with an hyperemic state on admission or after optimization of therapy did not have hospital mortality, and 73% had Glasgow outcome score of 4 or greater at six months of follow up. On the other hand, 50% of those with hypoperfusion or global ischemia died during hospitalization and 72% had a Glasgow outcome score of 3 or less at six months. Patients not subjected to cerebral metabolic monitoring behave as those with hypoperfusion or global ischemia. CONCLUSIONS: Cerebral metabolic monitoring is an useful tool to optimize the management of patients with acute cerebral injury, and those patients with an hyperemic cerebral state have the best prognosis.
Assuntos
Encéfalo/metabolismo , Transtornos Cerebrovasculares/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular , Transtornos Cerebrovasculares/mortalidade , Cuidados Críticos , Estudos Transversais , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Estudos RetrospectivosRESUMO
Se analizan 80 ninos con hidrocefalia, a los que se les instalo valvula de derivacion de L.C.R. ventriculo-cardiaca y ventriculo-peritoneal entre 1972 y 1978. Se realizo seguimiento satisfactorio en el 88% de los casos por un periodo de 3-10 anos, promedio cinco y medio anos. Hubo un 25% de mortalidad atribuible a la valvula, en su mayoria secundarias a infeccion valvular. La malfuncion y obstruccion valvular contribuyo en menor proporcion a la mortalidad, pero fue causa de reoperaciones. El grupo de mayor mortalidad lo formo el de los ninos con grave hidrocefalia congenita. Las infecciones rara vez postoperatorias (4%), fueron preferentemente alejadas de la cirugia y presumiblemente hematogenas. La frecuencia y gravedad de las infecciones valvulares fueron mayores en derivaciones ventriculo-cardiacas. El mejor resultado de valvulas ventriculo-peritoneales se deberia a estar en compartimiento menos expuesto a contaminacion microbiana