Publications by authors named "Luiz H Monteiro-Leal"

Quantification of immunostaining is a widely used technique in pathology. Nonetheless, techniques that rely on human vision are prone to inter- and intraobserver variability, and they are tedious and time consuming. Digital image analysis (DIA), now available in a variety of platforms, improves quantification performance: however, the stability of these different DIA systems is largely unknown.

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The prostate of the female gerbil (Meriones unguiculatus) is similar to the human female prostate (Skene gland) and, despite its reduced size, it is functional and shows secretory activity. However, virtually nothing is known about its physiological regulation. This study was thus undertaken to evaluate the behavior of the gerbil female prostate in a hyperandrogenic condition.

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The protozoon Giardia lamblia infects millions of people worldwide, most of them in underdeveloped countries, where it is frequently a hyperendemic disease. The search for an effective anti-Giardia treatment has been intense, but recurrent infections, virulence factors, and drug resistance imposed obstacles in the achievement of an efficient medication. Most papers about drug effects in Giardia are related to the trophozoite form, although viable cysts, the infective forms, are continuously eliminated in the stools during the treatment.

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This paper presents a detailed study of the caudal complex of Giardia lamblia and its relation to movements observed in this region. The caudal complex of Giardia, composed of axonemes from the caudal flagella plus associated microtubular sheets, was investigated by light, electron microscopy, and 3D reconstruction tools. By the use of video-microscopy and digital image processing techniques, we were able to visualize in detail the caudal movements.

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Corynebacterium diphtheriae strains displayed different degrees of attachment to HEp-2 cell monolayers with two distinct adherence patterns, termed localised (LA) and diffuse (DA). The LA phenotype predominated over the DA phenotype. The non-sucrose fermenting strains expressing DA pattern adhered mostly with high index values (> or =10bact/cell).

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Iron limitation may cause bacterial pathogens to grow more slowly; however, it may also stimulate these microorganisms to produce greater tissue damage, given that many virulence factors are controlled by the iron supply in the environment. The present study investigated the influence of low iron availability on the expression of proteins and surface sugar residues of two toxigenic strains of Corynebacterium diphtheriae subsp. mitis and evaluated their adherence to human group B erythrocytes and HEp-2 cells.

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Objective: Analysis of sperm heads using three different computer morphometrical tools and experimental conditions to find a more reliable and secure strategy among them.

Design: Controlled experiments on sperm morphology analysis from volunteers.

Setting: Laboratory of microscopy and imaging processing.

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The development of new technology and the possibility of fast information delivery by either Internet or Intranet connections are changing education. Microanatomy education depends basically on the correct interpretation of microscopy images by students. Modern microscopes coupled to computers enable the presentation of these images in a digital form by creating image databases.

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Giardia lamblia is a diplomonad that parasitizes the small intestine of vertebrates. The trophozoite is multiflagellar and its cytoskeleton presents a complex organization of microtubular structures. One of these, the adhesive disk, consists of a microtubular spiral.

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It has been recognised that adherence and invasion to host cells are important steps in the pathogenesis of entero-pathogenic bacteria, including Aeromonas caviae. However, the virulence factors of A. caviae remain, for the most part, poorly known.

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This work presents a computerized method to identify, detect, evaluate, and, by colored overlay, present gold particle pairs in electron microscopy (EM), even in wide-field views. Double gold immunolabeled specimens were analyzed in a LEO 912 electron microscope equipped with a 2k x 2k-pixel slow-scan cooled CCD camera connected to a computer with analySIS 3.1 PRO image processing software.

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While investigating the distribution of Leptomonas wallacei in the intestine of the insect host Oncopeltus fasciatus, promastigotes and cyst-like forms of L. wallacei were observed only in the midgut ventricles V(3) and V(4) and the hindgut. In video-microscopy, once contact had occurred, the parasites remained attached to the midgut epithelium.

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Corynebacterium diphtheriae, generally considered an extracellular coloniser, was evaluated for its ability to enter and survive within HEp-2 monolayers by gentamicin protection assay. Intracellular viability of HC01 strain, isolated from endocarditis, was more expressive (2.59%) than observed in 241 (0.

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Video-microscopy in combination with digital image processing was used to analyze dynamic processes associated to the life cycle of Giardia lamblia trophozoites. These parasites swim and attach to the epithelial cells, producing the disease known as Giardiasis. Giardia is a multiflagellar cell, presenting 4 pairs of flagella.

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The effects of metronidazole and furazolidone on Giardia lamblia trophozoites were analyzed by video-light and transmission electron microscopy. In addition, growth curves were drawn based on four concentrations of the drugs. The IC50 was 4.

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