Expression of cell cycle regulatory proteins in epithelial components of dental follicles

Dental follicle is a component of tooth germs, which remain adjacent to the crown of unerupted or impacted teeth. Under the influence of pathologic changes, however, dental follicles that possess reduced epithelium can proliferate into stratified squamous epithelium as far as originate dental cysts. In order to clarify the role of apoptosis and cellular proliferation herein, expression of p53 and PCNA was examined in epithelial components of dental follicles associated with impacted third molars by means of immunohistochemistry. A total of 40 cases was included in this study being 22 cases with reduced epithelium and 18 cases with stratified epithelium. Expression of p53 expression was weak or not detected in dental follicles with reduced and stratified squamous epithelium. By contrast, PCNA positive cells were evidenced in basal and supra basal layers of the stratified squamous epithelium and in reduced epithelium of dental follicles, but without any significant statistically differences between them (P > 0.05). In conclusion, these data suggest that dental follicles possess proliferative activity as depicted by PCNA-positive nuclei in some epithelial cells. However, the biological behavior of dental follicles during the late stage of dental eruptive process may not be associated with deregulation of death and/or cell proliferation.

Modifying Effects of Lemongrass Essential Oil on Specific Tissue Response to the Carcinogen N-Methyl-N-Nitrosurea in Female BALB/c Mice

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

Lack of Chemopreventive Activity of Agaricus blazei Mushroom on the Development of 1,2-Dimethylhydrazine-Induced Colonic Aberrant Crypt Foci in Rats

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

Autologous implant of bone marrow mononuclear cells as treatment of induced equine tendinitis

Superficial digital flexor tendonitis is an important cause of lameness in horses and its incidence ranges from 13% to 30%, depending on the horse's activity. This injury can occur in yearlings and compromise its carriers by reinjury or even impossibility to return to athletic life. In spite of the long period required for tendon repair, the scar tissue presents lack of elasticity and stiffness. As current treatment strategies produce only marginal results, there has been great interest in research of therapies that influence the quality or the speed of tendon repair. Stem cell therapy has shown promising results in degenerative diseases and cases of deficient healing processes. This study aims to evaluate the influence of autologous mesenchymal bone marrow stem cells in tendon healing, comparing treated and non-treated tendons. Superficial digital flexor tendonitis lesions were induced by collagenase infiltration in both forelimbs of 6 horses, followed by autologous implant in one of the forelimbs of each animal. The horses were evaluated using clinical, ultrasonographic, histopathologic, and immunohistochemical parameters. Tendon biopsies were performed at Day 48. Results found in the treatment group, such as high inflammatory cells infiltration, extracellular matrix synthesis, reduced amount of necrosis areas, small increase in cellular proliferation (KI-67/MIB-1), and low immunoreactivity to transforming growth factor P I, suggested the acceleration of tendon repair in this group. Further studies should be conducted in order to verify the influence of this treatment on later phases of tendon repair. Overall, after analysis of the results, we can conclude that cellular therapy with the mononuclear fraction of bone marrow has accelerated tendon repair at 48 days after treatment.

Avaliação da eficácia de diferentes protocolos de preparo do Plasma Rico em Plaquetas para uso em Medicina Equina

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

Area of Rests of Malassez in Young and Adult Rat Molars: Evidences in the Formation of Large Rests

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

MyoD, myogenin and proliferating cell nuclear antigen expression in growing Nile tilapia (Oreochromis niloticus L.)

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

Bioinformatical and in vitro approaches to essential oil-induced matrix metalloproteinase inhibition

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Can a Strychnos species be used as antiulcer agent? Ulcer healing action from alkaloid fraction of Strychnos pseudoquina St. Hil. (Loganiaceae)

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

Caracterização estrutural do fator de crescimento de fibroblasto-10 (FGF-10) e seu papel na fisiologia folicular ovariana

Background: Interest in folliculogenesis has grown extensively in recent years. Nevertheless, several aspects of follicular activity are still poorly understood. Thus, in vitro culture of ovarian follicles using new substances has been established as a very viable model, enhancing the prospects for a better understanding of follicular activity. Among the family members of the fibroblast growth factor (FGFs), FGF-10 has received recent attention for its ability to regulate the development of ovarian follicles and oocyte maturation. Given the relevance of FGF-10 in the folliculogenesis process, this review aimed to describe the structural features, expression and the main biological effects of FGF-10 on the development of ovarian follicles in mammals.Review: Along this work, it was shown aspects related to structural characterization of FGF-10 and its receptors, as well as FGF-10 expression in different cell types, emphasizing its importance to follicular development. FGF-10 is a paracrine member of the family of FGFs, and is characterized by promoting biological responses via cell surface receptors (FGFRs) of tyrosine kinase-type. of these receptors, FGFR-1, FGFR-2 and FGFR-3 may undergo alternative transcriptional arrangements, enabling the formation of two isoforms (b and c) that have varying degrees of affinity for the various FGFs. Thus, seven FGFR proteins (FGFRs 1b, 1c, 2b, 2c, 3b, 3c and 4) with different binding specificities are generated from the four FGFR genes. The FGFRs transmit intracellular signals after binding with the ligand through the phosphorylation of tyrosine, which activates various transduction patterns in the cytoplasm. The signal transduction of FGF-10 may occur through three main pathways: protein of rat sarcoma (Ras)/MAPK, PLC gamma/Ca(2+) and phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt), which are involved in the transmission of biological signals, leading to cellular proliferation and differentiation. FGF-10 mRNA expression was detected in the ovarian stroma, oocyte and theca cells of preantral and antral follicles. on the other hand, the expression of mRNA for FGF-10 receptors was found in, granulosa cells, theca cells, cumulus cells and oocytes. Although FGFs are widely distributed in different tissues and cell types, the importance and function of FGFs in the ovary are still poorly documented. FGF-10 has been shown to be an important mediator of mesenchymal and epithelial cell interactions during follicle development, promoting follicular survival, activation and growth. Besides the action on folliculogenesis, FGF-10 was recently identified as a growth factor able to improve oocyte competence. However, in antral follicles, the presence of FGF-10 is associated with increased follicular atresia, which matches its anti-estrogenic action.Discussion: From this review, we can conclude that FGF-10 is an important regulator of female reproduction. This growth factor acts in follicle survival, oocyte maturation, expansion of cumulus cells and proliferation of granulosa/theca cellsthrough direct and/or indirect actions in the control of folliculogenesis. Furthermore, FGF-10 seemed to have different effects throughout the follicular development. However, it is necessary to perform additional studies that may provide a better understanding about the importance of FGF-10 during folicullogenesis.

Uncaria tomentosa Aqueous-ethanol Extract Triggers an Immunomodulation toward a Th2 Cytokine Profile

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

Age-related histopathological lesions in the Mongolian gerbil ventral prostate as a good model for studies of spontaneous hormone-related disorders

The Meriones unguiculatus (Mongolian) gerbil has demonstrated significant prostatic responses to hormonal treatments, and to drugs against human prostatic hyperplasia Spontaneous neoplasia develops in the older animals. Thirty gerbils (age 18 months) were divided into non-affected and prostatic lesion bearers and the prostate lesions were evaluated morphologically, immunohistochemically and quantitatively. The most frequent changes were in epithelial sites and, namely prostatic intraepithelial neoplasias, microinvasive carcinomas and adenocarcinomas. In the stromal compartment, cellular hyperplasia, when verified, was always associated with the sites of anomalous epithelium. Additionally, larger deposition of collagen fibrils, generating stromal fibrosis, was found in all the old gerbils analysed. The quantitative analysis showed that prostatic tissue proportions differed in altered areas, being specific for each lesion type. Isolated nuclear and nucleolar parameters were not effective in diagnosing the malign potential of lesions. However, the cellular proliferation and death indexes indicated larger cellular turnover in invasive lesions such as carcinomas. With these analyses, it could be verified that old gerbils present high propensity to develop spontaneous prostate changes and this may aid in a better understanding of the biological behaviour of human prostate cancer.

Alterações cromossômicas causadas pela radiação dos monitores de vídeo de computadores

OBJETIVO: em decorrência dos questionamentos sobre o efeito deletério das radiações emitidas pelo campo eletromagnético (CEM) dos tipos ELF (extremely low frequency) e VLF (very low frequency) transmitidas pelos monitores de vídeo dos computadores (CRT), foi avaliada a freqüência de anomalias cromossômicas estruturais e a cinética do ciclo celular em indivíduos expostos por seu trabalho à radiação dos CRT. MÉTODOS: A pesquisa de aberrações cromossômicas foi realizada em 2.000 metáfases de primeira divisão celular obtidas de culturas de 48h de linfócitos de sangue venoso periférico de dez indivíduos expostos ao CRT (grupo E) e de dez controles (grupo C). A cinética do ciclo celular foi pesquisada pelos índices mitótico (IM) e de proliferação celular (IPC). RESULTADOS: A análise estatística evidenciou freqüências significativamente maiores de metáfases com anomalias cromossômicas (E=5,9%; C=3,7%) e anomalias/célula (E=0,066±0,026; C=0,040±0,026) nos indivíduos expostos aos CRTs. As alterações citogenéticas mais comuns foram as quebras cromatídicas, com freqüência de 0,034±0,016 no grupo E e de 0,016±0,015 no grupo C. As freqüências de IM e IPC não apresentaram diferenças significantes entre os grupos avaliados. CONCLUSÕES: Os resultados sugerem um efeito genotóxico do CEM emitido pelos CRTs devido à freqüência mais elevada de quebras cromatídicas, enfatizando a necessidade de haver um número maior de estudos com diferentes técnicas que vise a investigar a ação do CEM sobre o material genético.

Osteoblasts engulf apoptotic bodies during alveolar bone formation in the rat maxilla

During bone formation, as in other tissues and organs, intense cellular proliferation and differentiation are usually observed. It has been described that programmed cell death, i.e., apoptosis, takes place in the control of the cellular population by removing of the excessive and damaged cells. Although it is generally accepted that apoptotic bodies are engulfed by professional phagocytes, the neighboring cells can also take part in the removal of apoptotic bodies. In the present study, regions of initial alveolar bone formation of rat molars were examined with the aim to verify whether osteoblasts are capable of engulfing apoptotic bodies, such as professional phagocytes. Rats aged 11-19 days were sacrificed and the maxillary fragments containing the first molar were removed and immersed in the fixative solution. The specimens fixed in glutaraldehyde-formaldehyde were processed for light microscopy and transmission electron microscopy. For the detection of apoptosis, the specimens were fixed in formaldehyde, embedded in paraffin, and submitted to the TUNEL method. The results revealed round/ovoid structures containing dense bodies on the bone surface in close contact to osteoblasts and in conspicuous osteoblast vacuoles. These round/ovoid structures showed also positivity to the TUNEL method, indicating that bone cells on the bone surface are undergoing apoptosis. Ultrathin sections showed images of apoptotic bodies being engulfed by osteoblasts. Occasionally, the osteoblasts exhibited large vacuoles containing blocks of condensed chromatin and remnants of organelles. Thus, these images suggest that osteoblasts are able to engulf and degrade apoptotic bodies. (c) 2005 Wiley-Liss, Inc.

Anti-Angiogenic Effects of the Superantigen Staphylococcal Enterotoxin B and Bacillus Calmette-Guerin Immunotherapy for Nonmuscle Invasive Bladder Cancer

Purpose: We compared and characterized the effects of intravesical bacillus Calmette-Guerin and/or staphylococcal enterotoxin B for nonmuscle invasive bladder cancer.Materials and Methods: A total of 75 female Fisher 344 rats were anesthetized. of the rats 15 received 0.3 ml saline (control) and 60 received 1.5 mg/kg MNU (N-methyl-n-nitrosourea) intravesically every other week for 6 weeks. The rats were divided into 5 groups. The MNU and control groups received 0.3 ml saline. The bacillus Calmette-Guerin group received 10(6) cfu bacillus Calmette-Guerin. The staphylococcal enterotoxin B group received 10 mu g/ml staphylococcal enterotoxin B. The bacillus Calmette-Guerin plus staphylococcal enterotoxin B group received the 2 treatments simultaneously. Each group was treated intravesically for 6 weeks. At 15 weeks all bladders were collected for histopathological and immunological evaluation, and Western blot.Results: Papillary carcinoma (pTa) and high grade intraepithelial neoplasia (carcinoma in situ) were more common in the MNU group. Papillary hyperplasia was more common in the bacillus Calmette-Guerin and enterotoxin groups. Flat hyperplasia was more common in the bacillus Calmette-Guerin plus enterotoxin group. No significant toxicity was observed. The apoptosis and cellular proliferation indexes decreased in the bacillus Calmette-Guerin, enterotoxin and bacillus Calmette-Guerin plus enterotoxin groups compared to the MNU group. Intensified vascular endothelial growth factor, matrix metalloproteinase-9, Ki-67 and insulin-like growth factor receptor-1 immunoreactivity was verified in the MNU group, moderate in the bacillus Calmette-Guerin and enterotoxin groups, and weak in the bacillus Calmette-Guerin plus enterotoxin and control groups. In contrast, intense endostatin immunoreactivity was verified in the control and bacillus Calmette-Guerin plus enterotoxin groups.Conclusions: Bacillus Calmette-Guerin and staphylococcal enterotoxin B showed similar anti-angiogenic effects. Bacillus Calmette-Guerin plus enterotoxin treatment had additional activity compared to that of monotherapy. It was more effective in restoring apoptosis and balancing cellular proliferation, and it correlated with increased endostatin, and decreased vascular endothelial growth factor, matrix metalloproteinase-9, Ki-67 and insulin-like growth factor receptor-1 reactivity.