Structure, histochemistry, and ultrastructure of the epithelium and stroma in the gerbil (Meriones unguiculatus) female prostate

The female prostate has aroused scientific interest because it is subjected to the same diseases compromising the male prostate during aging. The objective of this work was to characterize structurally, cytochemically, and ultrastructurally the tissue compartments of the normal adult female prostate of Meriones unguiculatus gerbils. The morphological analyses showed that the gerbil's female prostate is constituted of a cluster of glands and ducts inserted in a musculofibrous stroma. The alveolar epithelium is differentiated and consisted of basal proliferating cells, intermediary cells, and secretory cells. The secretory cells are the most numerous cell type and continuously secrete glycoproteins. The basal cells are the source of the secretory cells and they are then responsible for the alveolus renovation. The prostatic stroma is abundant and rich in elastic and collagen fibers, which are closely associated with smooth muscle cells and fibroblasts. The results showed that the gerbil's female prostate shows morphological and ultrastructural homology to the human female prostate (Skene's gland), and despite being a small organ, it is a mature and physiologically active gland. (C) 2003 Elsevier Ltd. All rights reserved.

Intermolecular interactions and characterization of the novel factor Xa exosite involved in macromolecular recognition and inhibition: Crystal structure of human Gla-domainless factor Xa complexed with the anticoagulant protein NAPc2 from the hematophagous nematode Ancylostoma caninum

NAPc2, an anticoagulant protein from the hematophagous nematode Ancylostoma caninum evaluated in phase-II/IIa clinical trials, inhibits the extrinsic blood coagulation pathway by a two step mechanism, initially interacting with the hitherto uncharacterized factor Xa exosite involved in macromolecular recognition and subsequently inhibiting factor VIIa (K-i = 8.4 pM) of the factor VIIa/tissue factor complex. NAPc2 is highly flexible, becoming partially ordered and undergoing significant structural changes in the C terminus upon binding to the factor Xa exosite. In the crystal structure of the ternary factor Xa/NAPc2/selectide complex, the binding interface consists of an intermolecular antiparallel beta-sheet formed by the segment of the polypeptide chain consisting of residues 74-80 of NAPc2 with the residues 86-93 of factor Xa that is additional maintained by contacts between the short helical segment (residues 67-73) and a turn (residues 26-29) of NAPc2 with the short C-terminal helix of factor Xa (residues 233-243). This exosite is physiologically highly relevant for the recognition and inhibition of factor X/Xa by macromolecular substrates and provides a structural motif for the development of a new class of inhibitors for the treatment of deep vein thrombosis and angioplasty. (c) 2006 Elsevier Ltd. All rights reserved.

STRUCTURE OF THE RETE TESTIS OF THE CAT (FELIS-DOMESTICA, L)

The rete testis of the cat consists of 3 parts: a septal or interlobular part; a mediastinal part and a tunical part. The septal part contains the septal or transitory tubuli recti and the tubuli recti. The transitory tubules are formed as a confluence of the seminiferous tubules at the apex of the testicular lobules and the tubuli recti. The mediastinal rete is formed of long, straight channels which increase in size and become more irregular and anastomotic below the tunica albuginea at the cranial extremity of the testis. The end is characterized as the tunical part of the rete testis and communicates with the extratesticular rete testis. The channels all parts of the rete are lined by simple cuboidal or columnar epithelium. These epithelial channels are supported by a connective tissue containing smooth muscle cells. The framework tissue of the rete is more conspicuous at the cranial extremity of the testis, with a mio-connective matrix organization.

Correlation among immune response, morphogenesis of the granulomatous reaction and spleen lymphoid structure in murine experimental paracoccidioidomycosis

We studied the correlation among cellular immune response, the pattern of lung granulomatous lesions and alterations in spleen lymphoid structure in Swiss mice inoculated intravenously with Paracoccidioides brasiliensis strain 18. The animals were evaluated at 24, 48 and 96 h after infection and further studied weekly for 18 weeks by: (i) the macrophage migration inhibition test with phytohemagglutinin (PHA) and P. brasiliensis antigen (PbAg); and (ii) histopathology of the lung and spleen lesions. One group of animals was gamma -irradiated (8 Gy), infected under the same conditions and evaluated for the pattern of lung granulomatous lesions and spleen lymphoid structure at 24, 48 and 96 h after infection. During the first week of infection, the non-irradiated animals presented a positive response to PHA and PbAg, compact granulomas in the lungs and a typical hyperplasia of the spleen white pulp. However, from weeks 2 to 5, a depression of the cell-mediated immunity (CMI) response to PHA and PbAg was observed in association with granulomas presenting only large mononuclear cells and lacking both giant cells and a peripheral halo of small mononuclear cells. This pattern of granuloma formation was similar to that seen in gamma -irradiated animals, whose cells involved in CMI were absent. After week 7, the non-irradiated animals showed granulomas characterized by the presence of giant cells and a peripheral halo of small mononuclear cells. This type of granuloma was formed concomitantly with recovery of the CMI and of the lymphoid structure of the spleen. The results showed a correlation among granulomas composed of large mononuclear cells, hypoplasia of the splenic tissue and impaired CMI. This correlation indicated that although granuloma morphogenesis per se does not depend on the activation of CMI, this response is important at later stages during modulation of the cellular composition of the granulomas.

Active and exo-site inhibition of human factor Xa: Structure of des-Gla factor Xa inhibited by NAP5, a potent nematode anticoagulant protein from Ancylostoma caninum

Hookworms are hematophagous nematodes capable of growth, development and subsistence in living host systems such as humans and other mammals. Approximately one billion, or one in six, people worldwide are infected by hookworms causing gastrointestinal blood loss and iron deficiency anemia. The hematophagous hookworm Ancylostoma caninum produces a family of small, disulfide-linked protein anticoagulants (75-84 amino acid residues). One of these nematode anticoagulant proteins, NAP5, inhibits the amidolytic activity of factor Xa (fXa) with K-i = 43 pM, and is the most potent natural fXa inhibitor identified thus far. The crystal structure of NAP5 bound at the active site of gamma-carboxyglutamic acid domainless factor Xa (des-fXa) has been determined at 3.1 angstrom resolution, which indicates that Asp189 (fXa, S1 subsite) binds to Arg40 (NAP5, P1 site) in a mode similar to that of the BPTI/trypsin interaction. However, the hydroxyl group of Ser39 of NAP5 additionally forms a hydrogen bond (2.5 angstrom) with His57 NE2 of the catalytic triad, replacing the hydrogen bond of Ser195 OG to the latter in the native structure, resulting in an interaction that has not been observed before. Furthermore, the C-terminal extension of NAP5 surprisingly interacts with the fXa exosite of a symmetry-equivalent molecule forming a short intermolecular beta-strand as observed in the structure of the NAPc2/fXa complex. This indicates that NAP5 can bind to fXa at the active site, or the exosite, and to fX at the exosite. However, unlike NAPc2, NAP5 does not inhibit fVIIa of the fVIIa/TF complex. (c) 2007 Elsevier Ltd. All rights reserved.

Structure and ultrastructure of the ventral prostate of isogenic mice (C57B1/6J) submitted to chronic alcohol ingestion

Morphological and functional alterations caused by chronic alcohol ingestion in testes and accessory sex organs have been studied both in man and in laboratory animals. The aim of the present study was to examine the possible occurrence of deleterious effects of chronic alcohol ingestion on the secretory epithelium of the ventral prostate of mice. Twenty-four adult male C57BL/6J mice were divided into three groups. The alcohol-treated group was allowed to drink only 6% (v/v) ethanol, the isocaloric group received a diet of water/sucrose with a calorie content equivalent to a 6% alcohol solution and the control group received water. Both groups were fed ad libitum with solid Purina rat chow. After 120 days, animals from each group were anesthetized with ethyl ether, weighed and processed for light and transmission electron microscopy. The results demonstrated reduction in the glandular epithelium cell height and disorganization of the Golgi complex. Moreover, abundant membrane-bound structures, most likely representing cytoplasmic material, were observed, as well as accumulation of dense bodies. Statistical analysis showed that bodyweight gain was similar for both groups. In conclusion, chronic alcohol ingestion has harmful effects on the secretory epithelium cells of the ventral lobe of the prostate of mice after 120 days of treatment. (C) 2001 Harcourt Publishers Ltd.

Behavior of plant tissue in osmotic solutions

The effect of the concentration of sucrose solutions on the cellular structure of potato tissue in equilibrium at 27 degreesC was Studied. Two different methods of investigation were used to determine the volume of the different phases composing the cellular tissue of the potato when in equilibrium with the solutions. one based on data of the concentration itself and the overall volume of 2 mm slices after 48 h at equilibrium, and the other on microscopic images of cells in thin slices of fresh tissue stained with neutral red after an hour in equilibrium to show protoplasts, vacuoles and plasmolysis spaces. The results of these methods were compared with those obtained by a predictive thermodynamic approach considering the semipermeability of cell membranes. Phase volume data obtained from microscopic analysis were more similar to what was predicted by the theoretical model than those obtained by means of composition measurement. where the long equilibrium time apparently led to the loss of semi permeability of the cell membranes, since total volumes calculated without consideration of the cell membranes were similar to those measured. This suggests that the length of time of osmotic dehydration brings about a change in cell structure and the consequent involvement of a different mechanism in mass transfer. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Hormonal therapy in the senescence: Prostatic microenvironment structure and adhesion molecules

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of successive cambia and structure of wood in Gallesia integrifolia (Spreng.) Harms (Phytolaccaceae)

Stem diameter in Gallesia integrifolia (Spreng.) Harms (Phytolaccaceae) increases by forming concentric rings of xylem alternating with phloem, which show frequent anastomoses. After a period of primary growth and the formation of first (normal) ring of vascular cambium, further successive rings are initiated outside this cambium. The second ring of cambium originates from the pericycle parenchyma located between the proto-phloem, and the pericycle fibres. Each cambium produces centripetally secondary xylem and centrifugally secondary phloem. Differentiation of xylem precedes that of phloem and the first elements formed are always xylem fibres. Structurally, the vascular cylinder is composed by successive rings of secondary xylem and phloem. These rings are separated by wide bands of conjunctive parenchyma tissue. Presence of collateral vascular bundles with irregular orientation is observed in the region of anastomoses of two or more bands of conjunctive tissue. These bundles are surrounded by isodiametric, lignified and thick-walled cells. In some of the cambial rings, occurrence of polycentric rays was also noticed; these rays are tall, and characterized by the presence of meristematic regions that differentiated into thick-walled elements of secondary xylem. Origin and development of the successive cambia and the structure of xylem are discussed.

Reaction of rat connective tissue to implanted dentin tubes filled with mineral trioxide aggregate or calcium hydroxide

This study was conducted to observe the rat subcutaneous connective tissue reaction to the implanted dentin tubes filled with calcium hydroxide or mineral trioxide aggregate. The animals were sacrificed after 7 and 30 days, and the specimens were prepared for morphological study. Some undecalcified specimens were prepared for histological analysis with polarized light and Von Kossa technique for calcium. The results were similar for both studied materials. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was an irregular tissue like a bridge that was Von Kossa-positive. The dentin walls of the tubes exhibited in the tubules a structure highly birefringent to polarized light, usually like a layer and at different depths. It is possible that the mechanism of action of both materials has some similarity. Copyright © 1999 by The American Association of Endodontists.

Reaction of rat connective tissue to implanted dentin tube filled with mineral trioxide aggregate, Portland cement or calcium hydroxide.

The subject of this study was to observe the rat subcutaneous connective tissue reaction to implanted dentin tubes filled with mineral trioxide aggregate, Portland cement or calcium hydroxide. The animals were sacrificed after 7 or 30 days and the undecalcified specimens were prepared for histological analysis with polarized light and Von Kossa technique for mineralized tissues. The results were similar for the studied materials. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was an irregular tissue like a bridge that was Von Kossa-positive. The dentin walls of the tubes exhibited in the tubules a structure highly birefringent to polarized light, usually like a layer and at different depths. The mechanism of action of the studied materials has some similarity.

Calcium salts deposition in rat connective tissue after the implantation of calcium hydroxide-containing sealers

This study was conducted to observe the rat subcutaneous connective tissue reaction to implanted dentin tubes that were filled with mineral trioxide aggregate, Sealapex, Calciobiotic Root Canal Sealer (CRCS), Sealer 26, and the experimental material, Sealer Plus. The animals were sacrificed after 7 and 30 days, and the specimens were prepared for histological analysis after serial sections with a hard-tissue microtome. The undecalcified sections were examined with polarized light after staining according to the Von Kossa technique for calcium. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was irregular tissue, like a bridge, that was Von Kossa-positive. The dentin walls of the tubes exhibited a structure highly birefringent to polarized light, usually like a layer, in the tubules. These results were observed with all the studied materials, except the CRCS, which didn't exhibit any kind of mineralized structure. The results suggest that among the materials studied, the CRCS could have the least possibility of encouraging hard tissue deposition.

Reaction of rat connective tissue to implanted dentin tubes filled with a white mineral trioxide aggregate.

The purpose of this paper was to study the reaction of rat subcutaneous connective tissue to the implantation of dentin tubes filled with white mineral trioxide aggregate (MTA), a material that will be marketed. The tubes were implanted into rat subcutaneous tissue and the animals were sacrificed after 7 and 30 days. The undecalcified pieces were prepared for histological analysis with polarized light and von Kossa technique for mineralized tissues. Granulations birefringent to polarized light and an irregular structure like a bridge were observed next to the material; both were von Kossa positive. Also, in the dentin wall tubules a layer of birefringent granulations was observed. The results were similar to those reported for gray MTA, indicating that the mechanisms of action of the white and gray MTA are similar.

The plant energy-dissipating mitochondrial systems: Depicting the genomic structure and the expression profiles of the gene families of uncoupling protein and alternative oxidase in monocots and dicots

The simultaneous existence of alternative oxidases and uncoupling proteins in plants has raised the question as to why plants need two energy-dissipating systems with apparently similar physiological functions. A probably complete plant uncoupling protein gene family is described and the expression profiles of this family compared with the multigene family of alternative oxidases in Arabidopsis thaliana and sugarcane (Saccharum sp.) employed as dicot and monocot models, respectively. In total, six uncoupling protein genes, AtPUMP1-6, were recognized within the Arabidopsis genome and five (SsPUMP1-5) in a sugarcane EST database. The recombinant AtPUMP5 protein displayed similar biochemical properties as AtPUMP1. Sugarcane possessed four Arabidopsis AOx1-type orthologues (SsAOx1a-1d); no sugarcane orthologue corresponding to Arabidopsis AOx2-type genes was identified. Phylogenetic and expression analyses suggested that AtAOx1d does not belong to the AOx1-type family but forms a new (AOx3-type) family. Tissue-enriched expression profiling revealed that uncoupling protein genes were expressed more ubiquitously than the alternative oxidase genes. Distinct expression patterns among gene family members were observed between monocots and dicots and during chilling stress. These findings suggest that the members of each energy-dissipating system are subject to different cell or tissue/organ transcriptional regulation. As a result, plants may respond more flexibly to adverse biotic and abiotic conditions, in which oxidative stress is involved. © The Author [2006]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved.

Structure of myotoxin II, a catalytically inactive Lys49 phospholipase A2 homologue from Atropoides nummifer venom

Lys49 snake-venom phospholipase A2 (PLA2) homologues are highly myotoxic proteins which, although lacking catalytic activity, possess the ability to disrupt biological membranes, inducing significant muscle-tissue loss and permanent disability in severely envenomed patients. Since the structural basis for their toxic activity is still only partially understood, the structure of myotoxin II, a monomeric Lys49 PLA2 homologue from Atropoides nummifer, has been determined at 2.08 Å resolution and the anion-binding site has been characterized. © 2006 International Union of Crystallography. All rights reserved.