Tumoral angiogenesis has been widely studied by histochemical analysis but little has been done regarding morphology of these new vessels. The objective of this study was to perform a qualitative analysis of the angiogenic response to chemical induction with dimethylbenzanthracene (DMBA) and carbamide peroxide of squamous cell carcinoma in pouches of Syrian hamsters after different periods of treatment. Twenty-four Syrian golden hamsters, divided into three groups of eight animals each, had their right jugal pouches treated with a 5% DMBA solution three times a week and a 10% carbamide peroxide two times a week for 55, 70 and 90 days. The left pouch was considered the control. After tumor induction, five animals in each group had their pouches prepared for analysis under scanning electron microscopy and three animals for analysis under light microscopy. The control pouches showed a vascular system composed by few main vessels running parallel to the longest axis of the pouch with some branches. In the pouches submitted to tumor induction, a well-differentiated squamous cell carcinoma was present since 55 days induction in all samples. The new vascular system showed the presence of many tortuous vessels and the majority of them were veins and capillaries. Terminal loops were extremely sinuous adopting a glomerular or corkscrew shape. These tumor vessels are different from normal vessels, presenting irregular diameters, outpouchings and constrictions. Angiogenesis of sprouting and intussusceptive kind could be identified in the tumor pouches, and they were more frequent as the tumor developed.
The effects of anti-angiogenic therapies in guiding tumor angioarchitecture prompted us to examine the modifications in the vascular network of the oral squamous cell carcinoma (SCC) produced by the multitargeted tyrosine kinase inhibitor sunitinib malate. Twelve Syrian hamsters had their right buccal pouches submitted to tumor induction with dimethylbenzanthracene and carbamide peroxide for 55 days. The animals were then divided into two groups of six animals each; group I was treated with sunitinib malate and group II (control) was remained untreated. After 4 weeks, the hamsters had their vascular networks casted by Mercox® resin and analyzed by scanning electron microscopy. The qualitative study of the vascular network of the control tumor-bearing pouches showed images of intussusception and sprouting angiogenesis, flattened blood vessels, abrupt variations in their diameter, and a tortuous course. The samples treated with sunitinib exhibited a qualitative reduction of the signs of vascular proliferation. In addition, these casts presented an attenuation of the morphological features observed in the untreated tumor-bearing pouches. Quantitative analysis demonstrated that the pouches treated with sunitinib did not show a decrease (P > 0.05) in the vascular diameter and intervessel distances when compared with the control group. The results of the present study suggest that sunitinib may act on the vascular network of oral SCC, normalizing the blood vessels. However, further experiments should be performed in order to determine a judicious dose of this anti-angiogenic therapy.
The word angiogenesis indicates the formation of new vascular segments from existing vessels such as capillaries and venules. Blood vessel formation in tumors is the result of rapid, disorganized vascular growth through two distinct mechanisms: sprouting and intussusceptive angiogenesis. The objective of this study was to elucidate the morphological aspects of these two vascular growth mechanisms in oral squamous cell carcinoma induced in hamster buccal pouch. Eight Syrian golden hamsters had their right buccal pouch treated with DMBA 0.5% and 10% carbamide peroxide for 90 days in order to produce squamous cell carcinoma in this site. Next, buccal pouches of the animals were submitted to the vascular corrosion technique and then analyzed by scanning electron microscopy. The vascular figures of sprouts were observed in the entire vascular network of the buccal pouches, as opposed to the intussusceptive angiogenesis that was predominantly observed in the sub-epithelial network. It was possible to differentiate the figures of sprouts from artifacts by the analysis of the blind ending of these structures. Intussusceptive angiogenesis was identified by the presence of holes trespassing the lumen of the capillaries. Vascular expansion occurred through intussusceptive angiogenesis in two ways: by the fusion of the pillars to form a new capillary and, by increasing the girth of the pillar to form meshes. The method of corrosion associated with scanning electron microscopy proved to be an excellent tool to study the two types of angiogenesis in oral squamous cell carcinoma in the hamster buccal pouch.
Knowing the regeneration and structure of a species in different phytophysiognomies is extremely important to understand its pattern of occurrence. In spite of its importance, this type of study is still scarce in the Cerrado biome. In this perspective, this work aimed to compare the structure of the arboreal and regenerating strata of Annona coriacea in the cerrado sensu stricto and in the cerradão (savanna woodland). For that purpose, 13 plots of 400m² were installed in each physiognomy. All individuals of A. coriacea were sampled and had their diameter and height measured. The individuals were divided into regenerating and arboreal and were distributed in classes of height and diameter. Furthermore, the absolute density and the basal area of each extract were calculated in each physiognomy. The parameters were compared using the T-test. In total, 130 individuals of A. Coriacea were sampled, with 42 regenerating individuals in the cerrado sensu stricto and 49 in the cerradão. As for the arboreal individuals, 33 were sampled in the cerrado sensu stricto and 6 in the cerradão. All evaluated parameters revealed to be significantly different for the physiognomies. Based on these results, it is possible to affirm that A. coriacea did not present a distribution pattern in the two physiognomies, although it presents a better establishment success in the cerrado sensu stricto. In the cerradão, although the seeds can germinate, the seedlings fail to develop and reach the adult age.
ResumoIntrodução: O controle da pressão arterial contribui com a diminuição do risco cardiovascular (CV), porém determinar o alvo pressórico (AP) adequado para cada paciente continua desafiador. O Eighth Joint National Committee (JNC VIII) propôs, em 2014, metas pressóricas de acordo com comorbidades e idade. Contudo, em 2015, foi divulgado o estudo SPRINT que levantou a necessidade de almejar níveis tensionais mais baixos. O objetivo do atual estudo é verificar a prevalência de pacientes considerados dentro dos AP para o tratamento da HAS de acordo com o SPRINT e o JNC VIII, comparando-os. Métodos:Foram incluídos 68 pacientes hipertensos, com doença aterosclerótica manifesta e idade acima de 45 anos vinculados ao estudo multicêntrico "Efeito do Programa Alimentar Brasileiro Cardioprotetor na redução de eventos e fatores de risco na prevenção secundária para doença cardiovascular: Um Ensaio Clínico Randomizado", coordenado pelo HCor em parceria com o Ministério da Saúde, a partir do PROADI-SUS. Foram avaliadas as variáveis idade, pressão arterial sistólica (PAS) e diagnóstico de diabetes mellitus (DM). Os dados foram analisados no programa Microsoft Excel, através de classificação etária e diagnóstico de DM. Foram considerados como tendo atingido o AP segundo SPRINT, aqueles pacientes que apresentaram PAS até 120mmHg. Com relação ao estabelecido pelo JNC VIII, a PAS foi considerada dentro do AP quando ≤ 140mmHg, em pacientes até 59 anos com e sem DM e em pacientes acima de 60 anos com DM, e até 150mmHg para pacientes com mais de 60 anos sem DM.Resultados: A maioria dos pacientes eram homens e 31% com DM. Quando utilizada as metas do JNC VIII, 63,3% dos pacientes até 59 anos e com DM atingiram o AP, este percentual elevou-se para 90,4% entre os sem DM. Entre os pacientes acima de 60 anos, 70,5% daqueles com DM atingem o AP, prevalência que sobe para 89,4% entre aqueles sem DM. Quando utilizada o AP do SPRINT, 42,5% dos pacientes sem DM atingem o alvo, e apenas 25% no grupo com DM.
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