RESUMO
The rapid development of the aquaculture industry has global concerns with health management and control strategies to prevent and/or treat diseases and increase sustainability standards. Saprolegniosis is a disease caused by Saprolegnia parasitica, and is characterized by promoting an immunosuppression in the host. This study evaluated in vitro the extract and one active compound (polygodial) of Drimys winteri, a Chilean medicinal tree as a potential early immunostimulatory aid in Saprolegniosis control. Atlantic salmon (Salmo salar) head kidney cells (ASK-1) were incubated with both extract and pure polygodial before exposure to S. parasitica mycelium, and the expression of the immune-related genes interleukin 1ß (IL-1ß), interferon α (IFNα), and major histocompatibility complex II (MHCII) was evaluated. Both evidenced immunomodulatory capacities by increasing gene expressions. This immunomodulation related to a mitigatory action counteracting the immunosuppressing effects of S. parasitica. Despite that most immune-related genes were up-regulated, the down-regulation of MHCII, characteristic of S. parasitica infection, was lessened by pre-incubation with the compounds. This study provides the first insight on the potential of D. winteri bark extract as a possible immunomodulatory and defensive strategy against this oomycete infection in fish.
Assuntos
Drimys/química , Doenças dos Peixes/imunologia , Infecções/veterinária , Extratos Vegetais/farmacologia , Salmo salar , Sesquiterpenos/farmacologia , Ração Animal/análise , Animais , Dieta/veterinária , Doenças dos Peixes/microbiologia , Infecções/imunologia , Infecções/microbiologia , Casca de Planta/química , Extratos Vegetais/química , Saprolegnia/fisiologia , Sesquiterpenos/químicaRESUMO
SETTING: Contact investigation of tuberculosis (TB) patients in Chilean prisons. OBJECTIVE: 1) To estimate TB incidence and the prevalence of latent tuberculous infection (LTBI) among prisoners and their contacts; and 2) to determine factors associated with disease transmission. DESIGN: Cross-sectional study conducted in 46 prisons (51% of the total prison population) to assess the prevalence of and risk factors for LTBI among contacts of prisoners newly diagnosed with pulmonary TB. We used in vitro interferon-gamma release assays to establish LTBI and a questionnaire to address risk factors. RESULTS: During the 1-year follow-up, we studied 418 contacts of 33 active TB cases. We found high TB incidence (123.9 per 100,000 prisoners) and high LTBI prevalence (29.4%) among contacts. LTBI rates are significantly higher in prison inmates than in non-prisoners (33.2% vs. 15.6%). Male sex, illicit drugs, malnutrition, corticosteroid use, low educational level and sharing a cell with a case increase the risk of LTBI. Multivariate analyses showed that corticosteroid use, duration of incarceration and overcrowding are the most relevant determinants for LTBI among all contacts. CONCLUSIONS: Our results confirm that incarceration increases the risk of tuberculous infection and TB disease, and that it was associated not only with origin from vulnerable groups, but also with the prison environment. Reinforcing TB control is essential to prevent TB transmission in prisons.
Assuntos
Transmissão de Doença Infecciosa/estatística & dados numéricos , Prisioneiros , Tuberculose Pulmonar/epidemiologia , Adulto , Antituberculosos/farmacologia , Chile , Busca de Comunicante , Estudos Transversais , Feminino , Humanos , Incidência , Masculino , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Prevalência , Fatores de Risco , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/transmissãoRESUMO
We use a stochastic simulation model to explore the effect of reactive intervention strategies during the 2002 dengue outbreak in the small population of Easter Island, Chile. We quantified the effect of interventions on the transmission dynamics and epidemic size as a function of the simulated control intensity levels and the timing of initiation of control interventions. Because no dengue outbreaks had been reported prior to 2002 in Easter Island, the 2002 epidemic provided a unique opportunity to estimate the basic reproduction number R0 during the initial epidemic phase, prior to the start of control interventions. We estimated R0 at 27.2 (95%CI: 14.8, 49.3). We found that the final epidemic size is highly sensitive to the timing of start of interventions. However, even when the control interventions start several weeks after the epidemic onset, reactive intervention efforts can have a significant impact on the final epidemic size. Our results indicate that the rapid implementation of control interventions can have a significant effect in reducing the epidemic size of dengue epidemics.
Assuntos
Número Básico de Reprodução , Dengue/epidemiologia , Dengue/transmissão , Surtos de Doenças , Epidemias , Adolescente , Adulto , Fatores Etários , Algoritmos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Matemática , Pessoa de Meia-Idade , Modelos Estatísticos , Polinésia , Processos Estocásticos , Fatores de Tempo , Adulto JovemRESUMO
Intussusception is an infrequent cause of mechanical intestinal obstruction in the adult. We present herein two clinical cases of intussusception with different etiologies. In the first case, the underlying cause was a lipoma, and in the second, it was metastasis from melanoma. In both cases the intussusception was identified through computed tomography and treatment was intestinal resection. Pathologic anatomy provided the definitive diagnosis. Etiology is diverse and it is more common for obstruction to be due to organic lesions that are malignant at the level of the colon and benign at the level of the small bowel. Currently there are more preoperative diagnoses thanks to the advances made in imaging study techniques. Intestinal resection continues to be the treatment of choice in the majority of cases, because of the high percentage of malignant lesions as the underlying cause.
Assuntos
Obstrução Intestinal/etiologia , Intussuscepção/complicações , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos do Sistema Digestório , Feminino , Humanos , Neoplasias Intestinais/complicações , Neoplasias Intestinais/patologia , Obstrução Intestinal/patologia , Obstrução Intestinal/cirurgia , Intussuscepção/patologia , Intussuscepção/cirurgia , Masculino , Melanoma/complicações , Melanoma/patologia , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
Cyclic voltammetry and electron spin resonance techniques were used in the investigation of several potential antiprotozoal containing thiosemicarbazone and carbamate nitrofurans. In the electrochemical behaviour, a self-protonation process involving the nitro group was observed. The reactivity of the nitro anion radical for these derivatives with glutathione, a biological relevant thiol, was also studied in means of cyclic voltammetry. These studies demonstrated that glutathione could react with radical species from 5-nitrofuryl system. Furthermore, from the voltammetric results, some parameters of biological significance as E(7)(1) (indicative of the biological nitro anion radical formation), and [Formula: see text] (thermodynamic indicator the of oxygen redox cycling) have been calculated. We also evaluated the stability of the nitro anion radical in terms of the dimerization constant (k(d)). The nitrofuran-free radicals from cyclic voltammetry were characterized by electron spin resonance. A clear dependence between both the thiosemicarbazone or carbamate substructure and the length of the linker, furyl- or furylpropenyl-spacer, and the delocalization of the unpaired electron was observed. Through of biological assays we obtained important parameters that account for the selective anti-trypanosomal activity of these derivatives. The trypomastigote viability study showed that all derivatives are as active as in the epimastigote form of the parasite in a doses dependent manner.
Assuntos
Antiprotozoários/química , Antiprotozoários/farmacologia , Nitrofuranos/química , Nitrofuranos/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Sobrevivência Celular , Doença de Chagas/tratamento farmacológico , Técnicas Eletroquímicas , Espectroscopia de Ressonância de Spin Eletrônica , Glutationa/química , Humanos , Camundongos , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacologia , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
The purpose of this study was to determine the magnitude and distribution of acute gastrointestinal illness (GI) in the Chilean population, describe its burden and presentation, identify risk factors associated with GI and assess the differences between a 7-day, 15-day and a 30-day recall period in the population-based burden of illness study design. Face-to-face surveys were conducted on 6047 randomly selected residents in the Metropolitan region, Chile (average response rate 75·8%) in 2008. The age-adjusted monthly prevalence of GI was 9·2%. The 7-day recall period provided annual incidence rate estimates about 2·2 times those of the 30-day recall period. Age, occupation, healthcare system, sewer system, antibiotic use and cat ownership were all found to be significant predictors for being a case. This study expands on the discussion of recall bias in retrospective population studies and reports the first population-based burden and distribution of GI estimates in Chile.