Histology and histopathology Vol.27, nº12 (2012)

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http://hdl.handle.net/10201/178869

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Expression and localization of VEGF receptors in human fetal skeletal tissues
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Marini, Mirca; Sarchielli, Erica; Toce, Mariateresa; Acocella, Alessandro; Bertolai, Roberto; Ciulli, Carlotta; Orlando, Claudio; Sgambati, Eleonora; Vannelli, Gabriella Barbara
During development the vertebrate skeleton is the product of deriving cells from distinct embryonic lineages. The craniofacial skeleton is formed by migrating cranial neural crest cells, whereas the axial and limb skeletons are derived from mesodermal cells. The Vascular Endothelial Growth Factors (VEGFs) / receptors (VEGFRs) system plays an important role in angiogenesis, as well as osteogenesis, during bone development, growth, and remodeling, attracting endothelial cells and osteoclasts and stimulating osteoblast differentiation. Recent evidence has shown that during development VEGFR-3 is also expressed in neural and glial precursors of forebrain and cerebellum, as well as in the eye. In this study, we found that VEGFR-1, VEGFR-2 and VEGFR-3 are expressed in human bone both in fetal and adult life. The gene expression levels were significantly higher in fetal samples especially in mandibles. In addition, higher levels of VEGFR-3 in orofacial district were confirmed by western blotting analysis. We also observed that in fetal mandibular samples VEGFRs colocalized in several osteoblasts, osteoclasts and osteoprogenitor cells. Furthermore, some cells coexpressed VEGFR-3 and ET-1, a marker of neural crest cells. The results demonstrated different expression of VEGFRs in human mandibular and femoral bones which could be correlated to their different structure, function and development during organogenesis. VEGFR-3 might represent a specific signal for ectomesenchymal lineage differentiation during early human development.
Open Access
Proposed mechanism in the change of cellular composition in the outer medullary collecting duct during potassium homeostasis
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Park, Eun-Young; Kim, Wan-Young; Kim, Yu-Mi; Lee, Jeong-Hwa; Han, Ki-Hwan; Weiner, I. David; Kim, Jin
Potassium depletion (K+-D) induces hypertrophy and hyperplasia of collecting duct cells, and potassium repletion (K+-R) induces regression of these changes. The purpose of this study was to examine the time courses of the changes in cellular composition, the origin of intercalated cells (ICs) and the mechanism responsible for these changes. SD rats received K+-depleted diets for 1, 7, or 14 days. After K+-D for 14 days some of the rats received normal diets for 1, 3, 5, or 7 days. In the inner stripe of the outer medulla, K+-D increased significantly the number and proportion of H+-ATPase-positive ICs, but decreased the proportion of H+-ATPase-negative principal cells (PCs). However, proliferation was limited to H+-ATPase-negative PCs. During K+-R, the cellular composition was recovered to control level. Apoptosis increased during K+-R and exclusively limited in H+-ATPase-negative PCs. Double immunolabeling with antibodies to PC and IC markers identified both cells negative or positive for all markers during both K+-D and K+-R. Electron microscopic observation showed that ultrastructure of AE1-positive some cells were similar to AE1-negative some cells during K+-R. LC3 protein expression increased significantly and autophagic vacuoles appeared particularly in PCs on days 14 of K+-D and in ICs on days 3 of K+-R. These results suggest that PCs and ICs may interconvert in response to changes in dietary K+ availability and that autophagic pathways may be involved in the interconversion.
Open Access
Fluorescence in situ hybridization for ambiguous melanocytic tumors
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Gammon, Bryan; Gerami, Pedram
The large majority of melanocytic lesions can be reliably classified as either benign or malignant based upon morphology alone, but a minority of lesions remains difficult to classify by traditional histologic methods. Recently, a panel of fluorescence in situ hybridization (FISH) probes targeting loci on chromosomes 6 and 11 has emerged as a powerful tool to discriminate melanoma from nevi. This has been validated in numerous difficult diagnostic scenarios. In addition, this same FISH panel has been shown to provide independent prognostic information in traditional melanomas. There is accumulating evidence that FISH targeting these loci as well as several other key chromosomal loci such as 9p21 and 8q24 can provide valuable prognostic information in histologically ambiguous melanocytic tumors. However, since the vast majority of atypical spitz tumors have an indolent course, larger studies including adequate numbers of cases with adverse events is necessary to provide sufficient proof of its role in clinically relevant cases. In this review, we discuss the current literature and studies to date on this topic.
Open Access
Characterization of the lectin binding pattern in human spermatozoa after swim-up selection
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Gómez-Torres, María José; Girela, Jose Luis; Murcia, Verónica; Fernández-Colom, Pedro José; Romeu, Alberto; Juan, Joaquín de; Avilés Sánchez, Manuel
Capacitation is characterized by a hyperactivated pattern of sperm motility. The acquisition of highly motility is present in the early stages of capacitation. Sperm progressive motility is one of the most important parameters for determining the suitability of semen for processing. However, previous studies have shown that some sperm showing good motility have membrane damage. The aim of our study was to characterize the lectin staining pattern on the sperm plasma membrane of unselected and selected human sperm of normozoospermic donors. Sperm selection was performed by the swim-up technique. Fourteen samples from healthy consenting donors classified as normozoospermic according to the World Health Organization were used. We observed changes in the distribution of the carbohydrate residues after the swim-up selection. With Triticum vulgaris, the most abundant pattern was dotted labeling all over the head plasma membrane in the unselected sperm. However, this lectin was distributed homogenously over the acrosomal region after selection. With Arachis hypogaea, the most abundant pattern in fresh sperm was a highly stained acrosomal region. In the highly motility sperm population, the most frequent pattern was dotted fluorescence on the acrosomal region and a highly stained equatorial segment. Meanwhile, with the Aleuria aurantia and Canavalia ensiformis lectins, the most representative patterns were the same before and after the swim-up selection. Our data indicate that modifications which occur in carbohydrate residues during swim-up selection could be important for the regulation of progressive motility and prepare the sperm for capacitation.
Open Access
Evaluation of tissue response and genotoxicity of poly(L/D-lactic acid) disks implanted in rat calvarium
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Gonçalves Göelze, Juliana; Linard Avelar, Rafael; do Nascimento Dolzan, André; Emmel Becker, Otávio; Haas Junior, Orion Luiz; de Oliveira, Luciane Yumi Suzuki; de Oliveira, Rogério Belle
The aim of the present study was to evaluate local and cytotoxicity systemic tissue reaction in the skull of rats using the implantation of disks of poly (lactic L/D-acid) and evaluate its genotoxicity. 25 males Wistar rats were used, 20 animals underwent surgical procedures and had the discs implanted in the parietal bone, and 5 animals received postoperative medication in the same way, serving as a control group for genotoxicity. The results were subjected to statistical evaluation by analysis of variance (ANOVA). In histological evaluation, between periods of 90 and 120 days in the control group, a new formation at the edges of the defect was noticed. In the experimental group, there was new bone formation at the edges of the defect, migrating below the site occupied by the disk, an absence of inflammatory infiltrate. Regarding the evaluation of genotoxicity, a significant reduction in the frequency of polychromatic erythrocytes in relation to negative control or significant increase in the polychromatic erythrocytes with micronuclei was not detected. So, the material used in this study is biocompatible and well tolerated by the tissues studied, and found to be negative for chromosomal mutagenicity.

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