RESUMEN
The temporal dynamics of leaf decomposition in a tropical stream were evaluated by measuring the input of leaves from riparian vegetation. The resulting mixture of leaves was processed by decomposer microorganisms and, in particular, by aquatic hyphomycetes, the most important microorganisms associated with leaf litter decomposition. Leaf decomposition and the characteristics and activity of the microbial community were investigated over the course of 1 year; these parameters depended on the composition and availability of leaves in the stream. We assessed the biomass, activity, and community structure of the fungi associated with the decomposing leaf mixtures monthly in a tropical stream with little seasonal variation in water characteristics. The leaf material included 27 riparian species; the amount of leaves of each contributing species varied from month to month, with higher overall values in the rainy season. Leaf decomposition was slow, and leaf mass loss did not occur monthly; however, leaf mass loss was significantly lower in May and September. The values of ATP, the ergosterol concentration, and the sporulation of aquatic hyphomycetes varied during the experiment, and only the ergosterol concentration (fungal biomass) was correlated with leaf mass loss. The sporulation rates of aquatic hyphomycetes peaked at the beginning of the rainy season (October), when only three hyphomycete species were present out of the total of seven that were found during the year. In this tropical stream, where the physical and chemical characteristics of the stream water varied little during the year, we hypothesize that changes related to leaf chemical composition could be the cause of changes in decomposition and the abundance and composition of the fungal assemblages. No significant differences were found for the parameters analyzed (lignin, cellulose, fiber, phosphorous, and polyphenols).
Asunto(s)
Hojas de la Planta , Biomasa , Brasil , Ecosistema , RíosRESUMEN
Tumoural and cystic lesions are common findings in the daily practice of dental professionals and maxillofacial radiologists. However, simultaneous lesions are rare and represent a diagnostic challenge to overcome. Among tumoural pathologies, odontomas are the most common odontogenic tumour of the jaws. Cystic transformation or development from the tumoural capsule are well recognized in situations such as ameloblastomas originated from a dentigerous cyst. Otherwise, despite literature reports, dentigerous cysts arising from odontomas are very rare and could lead to misdiagnosis. Here, we report a case of a complex odontoma associated with a dentigerous cyst in the maxillary sinus, focussing on the tomographic features and a differential imaging approach to the diagnosis of these lesions.
Asunto(s)
Quiste Dentígero/diagnóstico por imagen , Neoplasias del Seno Maxilar/diagnóstico por imagen , Odontoma/diagnóstico por imagen , Adulto , Quiste Dentígero/complicaciones , Diagnóstico Diferencial , Humanos , Masculino , Neoplasias del Seno Maxilar/complicaciones , Odontoma/complicaciones , Tomografía Computarizada por Rayos XRESUMEN
Systemic lupus erythematosus (SLE) patients have increased cardiovascular morbidity and mortality. QT-interval parameters are presumed markers of cardiovascular risk and have not been previously evaluated in SLE. Standard 12-lead ECGs were obtained from 140 female SLE outpatients and 37 age and body mass index-matched controls. QT interval was measured in each lead and heart rate-corrected maximum QT-interval duration (QTcmax) and QT-interval dispersion (QTd) were calculated. Risk factors for cardiovascular disease and lupus clinical features, disease treatment, disease activity and damage index were recorded. SLE patients have increased QT-interval parameters when compared to controls (QTcmax: 427.91 +/- 31.53 ms(1/2) versus 410.05 +/- 15.45 ms(1/2), P < 0.001; QTd: 52.38 +/- 22.21 ms versus 37.12 +/- 12.88 ms, P < 0.001). These differences persisted after excluding those patients with arterial hypertension, diabetes and with ECG abnormalities (QTcmax: 419.90 +/- 28.78 ms(1/2) versus 409.15 +/- 15.85 ms(1/2), P = 0.041; QTd: 54.74 +/- 26.00 ms versus 37.96 +/- 13.05 ms, P = 0.001). Multivariate linear regression for factors associated with QTcmax selected the presence of electrocardiographic left ventricular hypertrophy (ECG-LVH) (P = 0.003), nonspecific ST-T-wave abnormalities (P = 0.022) and left atrial enlargement (P = 0.044). Multivariate associates with QTd were age (P = 0.018), ECG-LVH (P = 0.022) and ST-T abnormalities (P = 0.031). In conclusion, SLE patients have increased QT interval parameters when compared to controls. This prolongation may lead to an increased cardiovascular risk. This finding might be due to subclinical atherosclerotic cardiovascular disease.