Óleo essencial de Baccharis tridentata Vahl: composição química, atividade antioxidante e fungitóxica, e caracterização morfológica das estruturas secretoras por microscopia eletrônica de varredura / Baccharis tridentata Vahl essential oil: chemical composition, and antioxidant and fungitoxic activities and morphological characterization of secretory structures by scanning electron microscopy

Este trabalho teve como objetivos avaliar a composição química do óleo essencial de Baccharis tridentata Vahl, as atividades antioxidante e fungitóxica, e estudar a morfologia das estruturas secretoras do óleo essencial presentes na superfície foliar por meio de microscopia eletrônica de varredura (MEV). A extração do óleo essencial foi realizada por hidrodestilação, as análises quantitativas e qualitativas foram executadas por meio de cromatografia em fase gasosa com detector de ionização de chamas (FID) e acoplada à espectrometria de massas, respectivamente. A atividade antioxidante foi realizada empregando-se os métodos de redução do radical estável DPPH e o ensaio de oxidação do sistema β-caroteno/ácido linoleico. As atividades fungitóxicas foram avaliadas utilizando o teste bioanalítico in vitro, sobre a inibição do crescimento micelial dos fitopatógenos Fusarium oxysporum, Colletotrichum gloeosporioides e Rhizoctonia solani. A composição química revelou a presença de 28 compostos, sendo o α-tujeno (22,93 por cento) o constituinte majoritário; não foi observada atividade antioxidante por meio dos ensaios utilizados, no entanto, observou-se atividade fungitóxica sobre o crescimento micelial dos fitopatógenos estudados. Já os estudos da superfície foliar por MEV revelaram a presença de tricomas glandulares em ambas as superfícies abaxial e adaxial.

This study aimed to evaluate the chemical composition and the antioxidant and fungitoxic activities of Baccharis tridentata essential oil, as well as to study the morphology of its secretory structures present on the leaf surface by scanning electron microscopy (SEM). The essential oil was extracted by hydrodistillation; the quantitative and qualitative analyses were performed on a gas chromatograph equipped with a flame ionization detector (FID) and coupled to a mass spectrometer, respectively. The antioxidant activity was determined by the methods of reduction of the DPPH stable radical and oxidation of the β-carotene/linoleic acid system. Fungitoxic activities were assessed by the in vitro bioanalytical test on the inhibition of the mycelial growth of the plant pathogens Fusarium oxysporum, Colletotrichum gloeosporioides and Rhizoctonia solani. The chemical composition revealed the presence of 28 compounds, with α-thujene (22.93 percent) as the major constituent. No antioxidant activity was observed in the tests used; however, there was fungitoxic activity against the mycelial growth of plant pathogens. Leaf surface studies by SEM revealed the presence of glandular trichomes on both abaxial and adaxial surfaces.

Tumor neuroendocrino de la mama: a propósito de un caso / Neuroendocrine tumor of the breast: a purpose of a case

Los tumores neuroendocrinos en la glándula mamaria, representan menos del 2 por ciento de las lesiones malignas que se presentan en la mama, un 30 por ciento pueden ser metastásicos, principalmente de tumores carcinoides intestinales. Se presenta el caso de una paciente femenina 64 años con el antecedente de carcinoma de mama izquierda pT1N1Mo Estadio II A, se le practicó en el año 2000 cirugía preservadora, recibió tratamiento sistémico y radioterapia, presentando recaída local, histológicamente y por inmuhistoquímica, como tumor neuroendocrino, en mayo de 2008 se le realiza mastectomía simple izquierda. Actualmente viva y sin enfermedad. Los tumores neuroendocrinos pueden presentarse en localizaciones extra intestinales. El diagnóstico debe realizarse por histología y confirmado con técnicas de inmunohistoquímica, son tumores de baja agresividad biológica, no se presentan síntomas sistémicos por liberación de hormonas como en otras localizaciones, y el tratamiento debe basarse en el estadio clínico de la enfermedad al momento del diagnóstico.

Neuroendocrines in the mammary gland tumors represent less than 2 percent of malignant injuries, which 30 percent can be source metastatic, mainly tumors intestinal carcinoid. The clinical of a female patient case 64 years old are presented with the antecedent of pT1N1Mo Stadium II A left breast carcinoma who was practiced in the year 2000 sparing surgery, received systemic therapy and radiotherapy, featuring local relapse, histological and inmuhistochemestry, as neuroendocrines, practicing it in May of 2008 mastectomy left, currently living and without disease tumor. Neuroendocrines tumors can occur in extra intestinal in lung, uterine and less common in the mammary gland neck locations. The diagnosis must be made by histology and confirmed with Immunohistochemistry techniques, are tumors of low biological aggression, not have systemic symptoms by release of hormones as in other locations, and treatment must be based on the clinical stage of the disease at the time of diagnosis.

Secretory organelles of pathogenic protozoa

Processos de secreção celular desempenham papel relevante na biologia e no ciclo de vida de protozoários patogênicos. A presente revisão analisa, sob uma perspectiva de biologia celular, o processo de secreção em (a) micronemas, roptrias e grânulos densos encontrados em membros do grupo Apicomplexa, onde essas estruturas participam da penetração do protozoário no interior da célula hospedeira, na sua sobrevivência intravacuolar e no posterior egresso da célula hospedeira, (b) a fenda de Maurer, encontrada em Plasmodium, uma estrutura envolvida na secreção de proteínas sintetizadas pelo protozoário intravacuolar e transportada, através de vesículas, para a superfície do eritrócito, (c) a secreção de macromoléculas na bolsa flagelar de tripanosomatídeos, e (d) a secreção de proteínas que fazem parte da parede cística de Giardia e Entamoeba e que se concentram nas vesículas de encistamento.

A unique mechanism of nuclear division in Giardia lamblia involves components of the ventral disk and the nuclear envelope

The fine structure of the binucleate, parasitic protist Giardia lamblia during interphase and divisional stages was studied by serial thin sectioning and three-dimensional reconstructions. The earlier sign of nuclear division is the development of a few peripheral areas of densely packed chromatin directly attached to the inner nuclear envelope. An intracytoplasmic sheet of ventral disk components grows from the cell periphery towards one of the nuclei, apparently constricting this nucleus, which becomes located at a ventral bulge. After the basal bodies become duplicated, a full nuclear division occurs in trophozoites, giving two pairs of parent-daughter nuclei. This full division occurs in a dorsal-ventral direction, with the resulting nuclear pairs located at the sides of the two sets of basal bodies. A new ventral disk is formed from the disk-derived sheets in the cell harboring the four nuclei. Cytokinesis is polymorphic, but at early stages is dorsal-to-dorsal. Encysting trophozoites show the development of Golgi cisternae stacks and dense, specific secretory granules. 3-D reconstructions show that cysts contain a single pair of incompletely strangled nuclei. The dividing Giardia lacks a typical, microtubular spindle either inside or outside the nuclei. The nuclear envelope seems to be the only structure involved in the final division of the parent-daughter nuclei.