Grading systems and perineural invasion in oral squamous cell carcinoma - a disease-specific survival analysis

Oral squamous cell carcinoma (OSCC) is an aggressive cancer, with prognosis influenced by clinical variables as well grading systems and perineural invasion (PNI), which are associated to poorer outcomes, including higher rates of recurrence and metastasis. This study aims to evaluate OSCC using three grading systems and assess the impact of PNI and clinicopathologic parameters on patient survival. Eighty-one primary OSCC samples were analyzed. Histopathological evaluations were performed utilizing Malignancy Grading of the Deep Invasive Margins, WHO grading system, and the Histologic Risk Assessment. S-100 immunohistochemistry was used to detect PNI. Five-year disease-specific survival (DSS) curves were generated using the Kaplan-Meier method, and the Cox proportional hazards model analyzed prognostic significance. Advanced clinical stage was significantly associated with reduced survival (p-value <0.001, HR = 4.07). Patients without regional lymph node involvement had better survival (p-value 0.002, HR = 0.37). Higher histologic risk assessment scores were linked to worse outcomes. Multifocal neural invasion significantly correlated with poorer survival compared to unifocal invasion (p-value 0.017, HR = 4.20). Patients undergoing surgery followed by adjuvant therapies had better survival rates. Besides clinical stage and histological grade, PNI also showed to be a crucial prognostic factor in OSCC, necessitating aggressive treatment strategies

Facial features of patients with sickle cell anemia

Objective: To characterize the craniofacial features of patients with sickle cell anemia (SCA). Materials and Methods: Fifty patients with SCA in the north of Minas Gerais, Brazil, were evaluated using standardized photographs (front and profile) for a subjective facial analysis and digital radiographs for a computerized cephalometric analysis. To obtain linear and angular measurements, cephalometric points were marked on the digital images by a single examiner, using the program Radiocef 6.0, and facial analyses were performed by four different orthodontists. Results: Of the population studied, 28 patients were female with a mean age of 27.7 years. Most of the patients (64%) had their faces classified as esthetically acceptable, although results showed a predominance of convex profiles (72%). The mean of the SNA angle was 84.56 degrees, diagnosing proper positioning of the maxilla from the base of the skull. The prevalence of pattern II was 32%, and 31% showed maxillary protrusion; the effective length of the maxilla was reduced in 64%. Retrusion of the mandible was observed in 30%, and 76% had reduced mandibular length. Four measurements (mandibular length, maxillary length, anterior face height, and maxillomandibular difference) showed statistically significant differences between genders, where these measurements were higher for males than for females. Conclusion: Most patients did not show compensatory maxillary expansion, which was determined by the prevalence of decreased maxillary length (64%) and by the absence of maxillary protrusion in 69% of the SCA patients evaluated. (Angle Orthod. 2011;81:115-120.)811115120Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG

Predicting species dominance shifts across elevation gradients in mountain forests in Greece under a warmer and drier climate

The Mediterranean Basin is expected to face warmer and drier conditions in the future, following projected increases in temperature and declines in precipitation. The aim of this study is to explore how forests dominated by Abies borisii-regis, Abies cephalonica, Fagus sylvatica, Pinus nigra and Quercus frainetto will respond under such conditions. We combined an individual-based model (GREFOS), with a novel tree ring data set in order to constrain tree diameter growth and to account for inter- and intraspecific growth variability. We used wood density data to infer tree longevity, taking into account inter- and intraspecific variability. The model was applied at three 500-m-wide elevation gradients at Taygetos in Peloponnese, at Agrafa on Southern Pindos and at Valia Kalda on Northern Pindos in Greece. Simulations adequately represented species distribution and abundance across the elevation gradients under current climate. We subsequently used the model to estimate species and functional trait shifts under warmer and drier future conditions based on the IPCC A1B scenario. In all three sites, a retreat of less drought-tolerant species and an upward shift of more drought-tolerant species were simulated. These shifts were also associated with changes in two key functional traits, in particular maximum radial growth rate and wood density. Drought-tolerant species presented an increase in their average maximal growth and decrease in their average wood density, in contrast to less drought-tolerant species

Spatial Pattern of Standing Timber Value across the Brazilian Amazon

The Amazon is a globally important system, providing a host of ecosystem services from climate regulation to food sources. It is also home to a quarter of all global diversity. Large swathes of forest are removed each year, and many models have attempted to predict the spatial patterns of this forest loss. The spatial patterns of deforestation are determined largely by the patterns of roads that open access to frontier areas and expansion of the road network in the Amazon is largely determined by profit seeking logging activities. Here we present predictions for the spatial distribution of standing value of timber across the Amazon. We show that the patterns of timber value reflect large-scale ecological gradients, determining the spatial distribution of functional traits of trees which are, in turn, correlated with timber values. We expect that understanding the spatial patterns of timber value across the Amazon will aid predictions of logging movements and thus predictions of potential future road developments. These predictions in turn will be of great use in estimating the spatial patterns of deforestation in this globally important biome

Simulating the carbon balance of a temperate larch forest under various meteorological conditions

<p>Abstract</p> <p>Background</p> <p>Changes in the timing of phenological events may cause the annual carbon budget of deciduous forests to change. Therefore, one should take such events into account when evaluating the effects of global warming on deciduous forests. In this article, we report on the results of numerical experiments done with a model that includes a phenological module simulating the timing of bud burst and other phenological events and estimating maximum leaf area index.</p> <p>Results</p> <p>This study suggests that the negative effects of warming on tree productivity (net primary production) outweigh the positive effects of a prolonged growing season. An increase in air temperature by 3°C (5°C) reduces cumulative net primary production by 21.3% (34.2%). Similarly, cumulative net ecosystem production (the difference between cumulative net primary production and heterotrophic respiration) decreases by 43.5% (64.5%) when temperatures are increased by 3°C (5°C). However, the positive effects of CO₂enrichment (2 × CO₂) outweigh the negative effects of warming (<5°C).</p> <p>Conclusion</p> <p>Although the model was calibrated and validated for a specific forest ecosystem, the implications of the study may be extrapolated to deciduous forests in cool-temperate zones. These forests share common features, and it can be conjectured that carbon stocks would increase in such forests in the face of doubled CO₂and increased temperatures as long as the increase in temperature does not exceed 5°C.</p

Autopercepção da necessidade de prótese dentária total entre idosos brasileiros desdentados

Resumo Propõe-se estimar a prevalência da autopercepção da necessidade de prótese dentária total entre idosos (65 a 74 anos) brasileiros desdentados, assim como identificar seus fatores associados. Trata-se de estudo transversal com base no inquérito nacional das condições de Saúde Bucal da população brasileira, denominado SB Brasil &#8211; 2010. A variável dependente foi a autopercepção da necessidade de prótese dentária total, considerando a aquisição de prótese nova ou substituição da existente. Foram conduzidas análises descritivas, bivariadas e múltiplas. Foram incluídos 3514 idosos, destes, 2039 (55,0%) perceberam a necessidade de prótese total. A autopercepção da necessidade de prótese total foi maior entre os que necessitavam de prótese dentária inferior e que estavam insatisfeitos com as suas condições de saúde bucal. Além da alta prevalência da autopercepção da necessidade de prótese identificada, os resultados permitiram identificar que condições normativas e subjetivas de saúde bucal se mantiveram associadas a esta autopercepção entre idosos brasileiros

Neuroprotection by adenosine in the brain: From A1 receptor activation to A2A receptor blockade

Adenosine is a neuromodulator that operates via the most abundant inhibitory adenosine A1 receptors (A1Rs) and the less abundant, but widespread, facilitatory A2ARs. It is commonly assumed that A1Rs play a key role in neuroprotection since they decrease glutamate release and hyperpolarize neurons. In fact, A1R activation at the onset of neuronal injury attenuates brain damage, whereas its blockade exacerbates damage in adult animals. However, there is a down-regulation of central A1Rs in chronic noxious situations. In contrast, A2ARs are up-regulated in noxious brain conditions and their blockade confers robust brain neuroprotection in adult animals. The brain neuroprotective effect of A2AR antagonists is maintained in chronic noxious brain conditions without observable peripheral effects, thus justifying the interest of A2AR antagonists as novel protective agents in neurodegenerative diseases such as Parkinson’s and Alzheimer’s disease, ischemic brain damage and epilepsy. The greater interest of A2AR blockade compared to A1R activation does not mean that A1R activation is irrelevant for a neuroprotective strategy. In fact, it is proposed that coupling A2AR antagonists with strategies aimed at bursting the levels of extracellular adenosine (by inhibiting adenosine kinase) to activate A1Rs might constitute the more robust brain neuroprotective strategy based on the adenosine neuromodulatory system. This strategy should be useful in adult animals and especially in the elderly (where brain pathologies are prevalent) but is not valid for fetus or newborns where the impact of adenosine receptors on brain damage is different