Tumor odontogênico queratocístico e considerações diagnósticas

Keratocystic odontogenic tumor (KCOT is benign, featuring controversies in diagnosis and treatment. It occurs mainly in the region of the mandibular angle, which may or may not be related to a tooth and whose importance is due to its aggressive behavior and high recurrence rate. The causes of high rates of relapse observed in this lesion are dependent on factors such as age, location and size of lesion, gender, type of treatment and histological variant. The thin capsule and friable connective tissue of KCOT may favor the retention of epithelial debris responsible for the high proliferative capacity of this clinical entity. Due to the aggressiveness with its recurrence this paper aims to conduct a literature review addressing clinical and imaging aspects, composes the histopathological diagnosis of KCOT.

Perfil inflamatório local e sistêmico de ratos Wistar com múltiplas infecções endodônticas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Microbial biomass and soil chemical properties under different land use systems in Northeastern Pará

O aumento da produção agrícola na Amazônia brasileira tem ocorrido devido, em grande parte, à expansão da fronteira agrícola, utilizando áreas já antropizadas ou avançando sobre a vegetação primária. Ao mesmo tempo, os sistemas agrícolas, na pequena produção, continuam utilizando o fogo no preparo da área, o que leva à perda da capacidade produtiva dos solos em curto espaço de tempo, forçando a abertura de novas áreas. Este trabalho avaliou o efeito de métodos de preparo do solo e tempo de pousio que envolvem queima e trituração da vegetação, com permanência na superfície ou incorporada ao solo, com ou sem adubação mineral, em duas épocas do ano sobre os atributos químicos e biológicos do solo. O experimento foi instalado em 1995 em um Latossolo Amarelo do campo experimental da Embrapa Amazônia Oriental, no nordeste do Estado do Pará. O delineamento experimental foi em blocos casualizados, arranjados em esquema fatorial 2 x 6, sendo dois sistemas de manejo e seis tratamentos, estudados em duas épocas de coleta. Os sistemas de manejo envolveram as culturas de arroz (Oriza sativa), seguido de feijão-caupi (Vigna unguiculata) e mandioca (Manihot esculenta). Um sistema constou de dois ciclos de cultivo seguidos, deixando em pousio por três anos; e o outro, de um ciclo de cultivo, deixando em pousio por três anos. Os tratamentos foram: corte e queima da vegetação, com adubação NPK (Q+NPK); corte e queima da vegetação, sem adubação NPK (Q-NPK); corte e trituração da vegetação, deixando-a na superfície do solo, com adubação NPK (C+NPK); corte e trituração da vegetação, deixando-a na superfície do solo, sem adubação NPK (C-NPK); corte e trituração da vegetação, com incorporação e com adubação NPK (I+NPK); e corte e trituração da vegetação, com incorporação e sem adubação NPK (I-NPK). As coletas de solo foram realizadas na estação mais chuvosa (abril de 2006) e na menos chuvosa (setembro de 2006), na profundidade de 0,0-0,1 m. Em cada parcela, foram coletadas 10 amostras simples para compor uma amostra composta. O sistema de manejo mais intensivo apresentou maiores teores de C microbiano (Cmic) e N microbiano (Nmic), ao passo que o sistema menos intensivo mostrou maio teor de C orgânico. Os tratamentos que apresentaram maior teor de Cmic e Nmic foram aqueles em que houve corte, trituração e deposição da biomassa na superfície do solo. Os atributos químicos nos dois sistemas de manejo encontram-se em faixas que enquadram os solos como de baixa fertilidade; no entanto, P e K (no período chuvoso) foram mais elevados no sistema de manejo menos intensivo.

Carbon content in Amazonian Oxisols after forest conversion to pasture

O solo desempenha importante papel no ciclo do C, porém a substituição da floresta tropical por áreas cultivadas altera a dinâmica e o estoque desse elemento. Em uma frente pioneira de colonização no município de Itupiranga (PA), na Amazônia Oriental, foi desenvolvido este estudo com o objetivo de avaliar as consequências da substituição de floresta nativa por pastagens de Brachiaria brizantha no conteúdo de C de um Latossolo Amarelo distrófico. As amostras de solo foram coletadas em área de floresta nativa (FN), floresta secundária de 8–10 anos (FS), pastagens de 1–2 anos (P1-2), de 5–7 anos (P5–7) e de 10–12 anos (P10–12), nas camadas de 0–2, 2–5 e 5–10 cm, para avaliar os teores e o estoque de C e realizar um fracionamento granulométrico da matéria orgânica. Após o desmatamento, a densidade do solo aumentou até a profundidade de 5 cm, sendo esse aumento maior nas pastagens mais antigas. As maiores mudanças no conteúdo de C ocorreram na camada superior do solo, havendo aumento nesse conteúdo com o tempo de implantação das pastagens. Nas camadas de 2–5 e 5–10 cm, o conteúdo de C se mostrou estável entre os tipos de cobertura vegetal avaliados. As maiores concentrações de C foram encontradas na fração silte, mas os maiores conteúdos de C ocorreram na fração argila, independentemente do tipo de cobertura vegetal. Um aumento da quantidade de C associado à fração areia, na forma de resíduos orgânicos pouco decompostos, foi observado nas pastagens, confirmando a maior sensibilidade dessa fração às mudanças de uso do solo.

Organic material decomposition and nutrient dynamics in a mulch system enriched with leguminous trees in the Amazon

As novas técnicas propostas para a agricultura na Amazônia incluem sistema de rotação de capoeira enriquecido com árvores leguminosas e transformando a queima da biomassa em cobertura morta sobre o solo. A decomposição e a liberação de nutrientes da cobertura morta foram estudadas usando sacos de liteira com malha fina que continham cinco tratamentos com diferentes espécies de leguminosas em comparação a um tratamento-controle com vegetação natural. As amostras para cada tratamento foram analisadas para conteúdos de C total, N, P, K, Ca, Mg, lignina, celulose e polifenóis solúveis em diferentes tempos de amostragem durante um ano. A razão constante de decomposição variou com a espécie e com o tempo. A perda de massa nos sacos de decomposição foi de 30,1 % para Acacia angustissima, de 32,7 % para Sclerolobium paniculatum, de 33,9 % para Inga edulis e para a vegetação secundária, de 45,2 % para Acacia mangium e de 63,6 % para Clitoria racemosa. Foi observada imobilização de N e P em todos os tratamentos, sendo a mineralização do N negativamente correlacionada com o fenol, razão C/N, razão (lignina + fenol)/N, razão fenol/P e o conteúdo de N nos sacos de liteira. Depois de 362 dias de incubação no campo, 3,3 % de K, 32,2 % de Ca e 22,4 % de Mg permaneceram no material em decomposição. Os resultados evidenciaram que a baixa qualidade mineral e a alta quantidade de carbono orgânico e aplicado como cobertura morta podem limitar a quantidade de energia disponível para os microrganismos resultando em uma competição por nutrientes com as plantas agrícolas.

Blood transfusions increase circulating plasma free hemoglobin levels and plasma nitric oxide consumption: a prospective observational pilot study

Introduction: The increasing number of reports on the relation between transfusion of stored red blood cells (RBCs) and adverse patient outcome has sparked an intense debate on the benefits and risks of blood transfusions. Meanwhile, the pathophysiological mechanisms underlying this postulated relation remain unclear. The development of hemolysis during storage might contribute to this mechanism by release of free hemoglobin (fHb), a potent nitric oxide (NO) scavenger, which may impair vasodilation and microcirculatory perfusion after transfusion. The objective of this prospective observational pilot study was to establish whether RBC transfusion results in increased circulating fHb levels and plasma NO consumption. In addition, the relation between increased fHb values and circulating haptoglobin, its natural scavenger, was studied. Methods: Thirty patients electively received 1 stored packed RBC unit (n = 8) or 2 stored packed RBC units (n = 22). Blood samples were drawn to analyze plasma levels of fHb, haptoglobin, and NO consumption prior to transfusion, and 15, 30, 60 and 120 minutes and 24 hours after transfusion. Differences were compared using Pearson's chi-square test or Fisher's exact test for dichotomous variables, or an independent-sample t test or Mann-Whitney U test for continuous data. Continuous, multiple-timepoint data were analyzed using repeated one-way analysis of variance or the Kruskall-Wallis test. Correlations were analyzed using Spearman or Pearson correlation. Results: Storage duration correlated significantly with fHb concentrations and NO consumption within the storage medium (r = 0.51, P < 0.001 and r = 0.62, P = 0.002). fHb also significantly correlated with NO consumption directly (r = 0.61, P = 0.002). Transfusion of 2 RBC units significantly increased circulating fHb and NO consumption in the recipient (P < 0.001 and P < 0.05, respectively), in contrast to transfusion of 1 stored RBC unit. Storage duration of the blood products did not correlate with changes in fHb and NO consumption in the recipient. In contrast, pre-transfusion recipient plasma haptoglobin levels inversely influenced post-transfusion fHb concentrations. Conclusion: These data suggest that RBC transfusion can significantly increase post-transfusion plasma fHb levels and plasma NO consumption in the recipient. This finding may contribute to the potential pathophysiological mechanism underlying the much-discussed adverse relation between blood transfusions and patient outcome. This observation may be of particular importance for patients with substantial transfusion requirements.

Signal transduction in Plasmodium-Red Blood Cells interactions and in cytoadherence

Malaria is responsible for more than 1.5 million deaths each year, especially among children (Snow et al. 2005). Despite of the severity of malaria situation and great effort to the development of new drug targets (Yuan et al. 2011) there is still a relative low investment toward antimalarial drugs. Briefly there are targets classes of antimalarial drugs currently being tested including: kinases, proteases, ion channel of GPCR, nuclear receptor, among others (Gamo et al. 2010). Here we review malaria signal transduction pathways in Red Blood Cells (RBC) as well as infected RBCs and endothelial cells interactions, namely cytoadherence. The last process is thought to play an important role in the pathogenesis of severe malaria. The molecules displayed on the surface of both infected erythrocytes (IE) and vascular endothelial cells (EC) exert themselves as important mediators in cytoadherence, in that they not only induce structural and metabolic changes on both sides, but also trigger multiple signal transduction processes, leading to alteration of gene expression, with the balance between positive and negative regulation determining endothelial pathology during a malaria infection.

High gradient magnetic separation (HGMS) of erythrocytes infected with plasmodium falciparum

This thesis was undertaken to explore possible applications of high gradient magnetic separation (HGMS) for the separation of RBCs infected with Plasmodium falciparum, with the dual aim of establishing a novel and superior method for isolating late-stage infected cells, and of obtaining synchronized cell cultures.rnThe presented work presents protocols for HGMS of parasitized RBCs that fulfil these aims. Late-stage parasitized cell can be isolated essentially devoid of contamination with non-infected and ring-stage infected cells. Such an easy method for a highly quantitative and qualitative purification has not yet been reported. Synchronous cultures can be obtained both following depletion of late-stage infected cells, and following isolation of the latter. The quality of synchronization cultures matches that of sorbitol lysis, the current standard method for malaria culture synchronization. An advantage of HGMS is the avoidance of osmotic stress for RBCs. The new methods further have the appeal of high reproducibility, cost-effectiveness, and simple protocol.rnIt should be possible to take the methods beyond Plasmodium infected RBCs. Most magnetic separation techniques in the sector of biomedical research employ columns with a hydrophilic polymer-coated matrix. Our procedure employs an optimized buffer system. Polymer coating becomes unnecessary and uncoated columns are available at a fraction of the cost.

Optimisation of chemical lysis protocol for point-of-care leukocyte differentiation

The full blood cell (FBC) count is the most common indicator of diseases. At present hematology analyzers are used for the blood cell characterization, but, recently, there has been interest in using techniques that take advantage of microscale devices and intrinsic properties of cells for increased automation and decreased cost. Microfluidic technologies offer solutions to handling and processing small volumes of blood (2-50 uL taken by finger prick) for point-of-care(PoC) applications. Several PoC blood analyzers are in use and may have applications in the fields of telemedicine, out patient monitoring and medical care in resource limited settings. They have the advantage to be easy to move and much cheaper than traditional analyzers, which require bulky instruments and consume large amount of reagents. The development of miniaturized point-of-care diagnostic tests may be enabled by chip-based technologies for cell separation and sorting. Many current diagnostic tests depend on fractionated blood components: plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets. Specifically, white blood cell differentiation and counting provide valuable information for diagnostic purposes. For example, a low number of WBCs, called leukopenia, may be an indicator of bone marrow deficiency or failure, collagen- vascular diseases, disease of the liver or spleen. The leukocytosis, a high number of WBCs, may be due to anemia, infectious diseases, leukemia or tissue damage. In the laboratory of hybrid biodevices, at the University of Southampton,it was developed a functioning micro impedance cytometer technology for WBC differentiation and counting. It is capable to classify cells and particles on the base of their dielectric properties, in addition to their size, without the need of labeling, in a flow format similar to that of a traditional flow cytometer. It was demonstrated that the micro impedance cytometer system can detect and differentiate monocytes, neutrophils and lymphocytes, which are the three major human leukocyte populations. The simplicity and portability of the microfluidic impedance chip offer a range of potential applications in cell analysis including point-of-care diagnostic systems. The microfluidic device has been integrated into a sample preparation cartridge that semi-automatically performs erythrocyte lysis before leukocyte analysis. Generally erythrocytes are manually lysed according to a specific chemical lysis protocol, but this process has been automated in the cartridge. In this research work the chemical lysis protocol, defined in the patent US 5155044 A, was optimized in order to improve white blood cell differentiation and count performed by the integrated cartridge.

Activation of a PAK-MEK signalling pathway in malaria parasite-infected erythrocytes

Merozoites of malaria parasites invade red blood cells (RBCs), where they multiply by schizogony, undergoing development through ring, trophozoite and schizont stages that are responsible for malaria pathogenesis. Here, we report that a protein kinase-mediated signalling pathway involving host RBC PAK1 and MEK1, which do not have orthologues in the Plasmodium kinome, is selectively stimulated in Plasmodium falciparum-infected (versus uninfected) RBCs, as determined by the use of phospho-specific antibodies directed against the activated forms of these enzymes. Pharmacological interference with host MEK and PAK function using highly specific allosteric inhibitors in their known cellular IC50 ranges results in parasite death. Furthermore, MEK inhibitors have parasiticidal effects in vitro on hepatocyte and erythrocyte stages of the rodent malaria parasite Plasmodium berghei, indicating conservation of this subversive strategy in malaria parasites. These findings have profound implications for the development of novel strategies for antimalarial chemotherapy.

Modeling of red blood cell life-spans in hematologically normal populations

Despite the impact of red blood cell (RBC) Life-spans in some disease areas such as diabetes or anemia of chronic kidney disease, there is no consensus on how to quantitatively best describe the process. Several models have been proposed to explain the elimination process of RBCs: random destruction process, homogeneous life-span model, or a series of 4-transit compartment model. The aim of this work was to explore the different models that have been proposed in literature, and modifications to those. The impact of choosing the right model on future outcomes prediction--in the above mentioned areas--was also investigated. Both data from indirect (clinical data) and direct life-span measurement (biotin-labeled data) methods were analyzed using non-linear mixed effects models. Analysis showed that: (1) predictions from non-steady state data will depend on the RBC model chosen; (2) the transit compartment model, which considers variation in life-span in the RBC population, better describes RBC survival data than the random destruction or homogenous life-span models; and (3) the additional incorporation of random destruction patterns, although improving the description of the RBC survival data, does not appear to provide a marked improvement when describing clinical data.

A KEL gene encoding serine at position 193 of the Kell glycoprotein results in expression of KEL1 antigen

BACKGROUND: The KEL2/KEL1 (k/K) blood group polymorphism represents 578C>T in the KEL gene and Thr193Met in the Kell glycoprotein. Anti-KEL1 can cause severe hemolytic disease of the fetus and newborn. Molecular genotyping for KEL*1 is routinely used for assessing whether a fetus is at risk. Red blood cells (RBCs) from a KEL:1 blood donor (D1) were found to have abnormal KEL1 expression during evaluation of anti-KEL1 reagents. STUDY DESIGN AND METHODS: Kell genotyping methods, including KEL exon 6 direct sequencing, were applied. KEL cDNA from D1 was sequenced. Flow cytometry was used to assess KEL1 and KEL2 RBC expression. RESULTS: RBCs from the donor, her mother, and an unrelated donor gave weak or negative reactions with some anti-KEL1 reagents. Other Kell-system antigens appeared normal. The three individuals were homozygous for KEL C578 (KEL*2) but heterozygous for a 577A>T transversion, encoding Ser193. They appeared to be KEL*2 homozygotes by routine genotyping methods. Flow cytometry revealed weak KEL1 expression and normal KEL2, similar to that of KEL*2 homozygotes. CONCLUSION: Ser193 in the Kell glycoprotein appears to result in expression of abnormal KEL1, in addition to KEL2. The mutation is not detected by routine Kell genotyping methods and, because of unpredicted KEL1 expression, could lead to a misdiagnosis.

Early resuscitation with polymerized bovine hemoglobin reverses acidosis, but not peripheral tissue oxygenation, in a severe hamster shock model

Awake hamsters equipped with the dorsal window chamber preparation were subjected to hemorrhage of 50% of the estimated blood volume. Initial resuscitation (25% of estimated blood volume) with polymerized bovine hemoglobin (PBH) or 10% hydroxyethyl starch (HES) occurred in concert with an equivolumetric bleeding to simulate the early, prehospital setting (exchange transfusion). Resuscitation (25% of estimated blood volume) without bleeding was performed with PBH, HES, or autologous red blood cells (HES-RBCs). Peripheral microcirculation, tissue oxygenation, and systemic hemodynamic and blood gas parameters were assessed. After exchange transfusion, base deficit was -8.6 +/- 3.7 mmol/L (PBH) and -5.1 +/- 5.3 mmol/L (HES) (not significant). Functional capillary density was 17% +/- 6% of baseline (PBH) and 31% +/- 11% (HES) (P < 0.05) and arteriolar diameter 73% +/- 3% of baseline (PBH) and 90% + 5% (HES) (P < 0.01). At the end, hemoglobin levels were 3.7 +/- 0.3 g/dL with HES, 8.2 +/- 0.6 g/dL with PBH, and 10.4 +/- 0.8 g/dL with HES-RBCs (P < 0.01 HES vs. PBH and HES-RBCs, P < 0.05 PBH vs. HES-RBCs). Base excess was restored to baseline with PBH and HES-RBCs, but not with HES (P < 0.05). Functional capillary density was 46% +/- 5% of baseline (PBH), 62% + 20% (HES-RBCs), and 36% +/- 19% (HES) (P < 0.01 HES-RBCs vs. HES). Peripheral oxygen delivery and consumption was highest with HES-RBCs, followed by PBH (P < 0.05 HES-RBCs vs. PBH, P < 0.01 HES-RBCs and PBH vs. HES). In conclusion, the PBH led to a correction of base deficit comparable to blood transfusion. However, oxygenation of the peripheral tissue was inferior with PBH. This was attributed to its negative impact on the peripheral microcirculation caused by arteriolar vasoconstriction.

Histo-blood group antigens as allo- and autoantigens

The science of blood groups has made giant steps forward during the last decade. Blood-group typing of red blood cells (RBCs) is performed on more than 15 million samples per year in Europe, today much less often for forensic reasons than for clinical purposes such as transfusion and organ transplantation. Specific monoclonal antibodies are used with interpretation on the basis of RBC agglutination patterns, and mass genotyping may well be on its way to becoming a routine procedure. The discovery that most blood group systems, whose antigens are by definition found on RBCs, are also expressed in multiple other tissues has sparked the interest of transplantation medicine in immunohematology beyond the HLA system. The one and only "histo-blood group" (HBG) system that is routinely considered in transplantation medicine is ABO, because ABO antigen-incompatible donor/recipient constellations are preferably avoided. However, other HBG systems may also play a role, thus far underestimated. This paper is an up-to-date analysis of the importance of HBG systems in the alloimmunity of transplantation and autoimmune events, such as hemolytic anemia.

Dynamics of red blood cells in microporous membranes

We have performed microfluidic experiments with erythrocytes passing through a network of microchannels of 20–25 μm width and 5 μm of height. Red blood cells (RBCs) were flowing in countercurrent directions through microchannels connected by μm pores. Thereby, we have observed interesting flow dynamics. All pores were blocked by erythrocytes. Some erythrocytes have passed through pores, depending on the channel size and cell elasticity. Many RBCs split into two or more smaller parts. Two types of splits were observed. In one type, the lipid bilayer and spectrin network were cut at the same time. In the second type, the lipid bilayer reconnected, but the part of spectrin network stayed outside the cell forming a rope like structure, which could eventually break. The microporous membrane results in multiple breakups of the cells, which can have various clinical implications, e.g., glomerulus hematuria and anemia of patients undergoing dialysis. The cell breakup procedure is similar to the one observed in the droplet breakage of viscoelastic liquids in confinement.