Quantitative analysis of potentially toxic metals in alginates for dental use

Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4mL concentrated HCI:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them.

Diferenciação hepatocítica de células-tronco mesenquimais da medula óssea humana

Some recent articles have reported that mesenchymal stem cells (MSCs) can be induced to express hepatocyte markers by transplanting them into animal models of liver damage, or by in vitro culture with growth factors and cytokines. In this study, the aim is to evaluate the behavior of MSCs subjected to induction of hepatocyte differentiation. The MSCs were isolated from the bone marrow of 4 normal donors, characterized and subjected to both in vitro and in vivo induction of hepatocyte differentiation. The in vitro induced cells showed morphological changes, acquiring hepatocyte-like features. However, the immunophenotype of these cells was not modified. The induced cells exhibited no increase in albumin, cytokeratin 18 or cytokeratin 19 transcripts, when analyzed by real-time RT-PCR. The expression of albumin, cytokeratin 18 and alpha fetoprotein was also unchanged, according to immunofluorescence tests. In vivo, the MSC demonstrated a potential to migrate to damaged liver tissue in immunodeficient mice. Taken together, the results suggest that bone marrow MSCs are incapable of in vitro differentiation into hepatocytes by the approach used here, but are capable of homing to damaged hepatic tissue in vivo, suggesting a role for them in the repair of the liver. This contribution to tissue repair could be associated with a paracrine effect exerted by these cells.

Acute phase proteins in canine lymphoma during antineoplastic chemotherapy

The lymphoma is the main hematopoietic tumor in dogs and it is characterized by the proliferation of cells from lymphoid tissue, histiocytes and its precursors. Animals with lymphoma often show changes in biochemical and hematological parameters such as non-regenerative normochromic normocytic anemia, hemolytic anemia, hypocalcaemia and monoclonal gammopathy. The development of tumor can cause alterations in serum concentrations of acute phase proteins (APPs), consequent of hepatocytes stimulus by cytokines of inflammatory action. This study aimed to quantify and qualify APPs in dogs with lymphoma, at diagnosis time and during the time of chemotherapy sessions. After syneresis, centrifugation and fractioning the serum samples of 10 healthy and 10 dogs with lymphomas, the proteins fractions were separated by polyacrilamide gel electrophoresis (SDS-PAGE) and its concentrations were determined by computer densitometry. Between 18 and 30 proteins were separated by eletrophoresis, with molecular weights ranging from 18 to 245 kDa (kilodaltons). The alpha-1-glicoprotein acid (AGP) and transferrin serum concentration showed significantly higher in dogs with lymphoma, when compared with healthy dogs at diagnosis. The alpha-1-antitripsin (AAT) serum concentrations showed significantly higher in healthy dogs, when compared with dogs with lymphoma at diagnosis. The dogs with lymphoma the albumin did not appear as negative APP. On the other hand, transferrin appeared as positive AAP at diagnosis time and during the chemotherapy sessions. Healthy dogs had AAT serum concentrations significantly higher when compared to dogs with lymphoma at diagnosis. So, in this trial, it is suggested that this protein has been shown as a negative APP in the dogs with lymphoma. These dogs presented significantly higher AGP serum concentrations, in relation to healthy dogs at diagnosis, evidencing this protein APP positive behavior in neoplasm.

Mammary benign neoplasm diagnosed by fine needle aspiration biopsy in a guinea pig (Cavia porcellus)

Cytology is a well established research technique in human and veterinary medicine, but it is rarely used in small rodents. Spontaneous tumors are relatively uncommon in guinea pigs and those described in literature include a variety of organs like skin and subcutis, respiratory and reproductive tract, endocrine and hematopoietic system, and mammary gland. The objective of this article was to describe the use of the fine needle aspiration biopsy technique (FNAB) on evaluation of a mammary neoplasm in a guinea pig and describe the main cytological findings for the first time in literature.

Mesenchymal stem cell therapy for equine tendinitis

Tendinitis is an important disease that leads to lameness and decreased performance in equine athletes and results in high costs associated with therapy due to a long recovery period and a high rate of recurrence. Although, several treatments for equine tendinitis have been described, few are effective in significantly improving the quality of the extracellular matrix and reducing the rate of recurrence. The use of cell therapy with mesenchymal stem cells (MSCs) derived from various sources has received much attention because of its therapeutic potential for equine tendinitis. In this paper, we review patents on stem cell therapy and the specific use of MSCs for the treatment of equine tendinitis. © 2013 Bentham Science Publishers.

Avaliação leucocitária de cães com linfoma submetidos ao protocolo de Madison-Wisconsin pela técnica convencional e citometria de fluxo

Lymphoma is the most common hematopoietic tumor in dogs and one of the malignant tumors with higher occurrence in this species. It is a great experimental model due to its resemblance with the non-Hodgkin lymphoma in humans. Considering the importance of the overall changes that result from to this kind of neoplastic tumor and those due to polichemotherapy this study aimed to evaluate the absolute leukon count and the total count of CD45+ cells in the blood of 25 dogs with lymphoma. Findings were crosschecked since diagnose and then once weekly during the first eight sessions of the Madison-Wisconsin chemotherapic protocol. Total granulocyte, lymphocyte and monocyte counts obtained from a conventional automatic counter and by flow cytometry were compared. Results did not reveal statistically significant changes between the two techniques.

Responses of melanocytes and melanomacrophages of Eupemphix nattereri (Anura: Leiuperidae) to Nle4, D-Phe7-α-melanocyte stimulating hormone and lipopolysaccharides

Melanocytes are found in various organs of ectothermic animals, playing a protective role against bacteria and free radicals. It is known that pigment cells from hematopoietic organs have immune functions. However, the role of visceral melanocytes is not well understood. Cutaneous melanocytes are responsive to α-melanocyte stimulating hormone (α-MSH), which is associated with the dispersion of melanin granules within melanocytes. α-MSH has also been reported to inhibit most forms of inflammatory responses by decreasing the pro-inflammatory cytokines and neutrophil migration. The present study evaluated the influence of an α-MSH analog (Nle4, D-Phe7-α-MSH) and lipopolysaccharides (LPS) from Escherichia coli on the liver and testicular tissues of the anuran Eupemphix nattereri. The tested hypotheses were: (i) the pigmented area will increase following hormone and LPS administration, (ii) pre-treatment with α-MSH will decrease the number of mast cells, and (iii) the hormone will have protective effects against LPS-induced responses. We found that hormone administration did not change hepatic pigmentation, but increased testicular pigmentation. Testicular pigmentation quickly increased after LPS administration, whereas there was a late response in the liver. The response of enhanced pigmentation was delayed and the number of mast cells decreased in animals previously treated with the α-MSH analog when compared to the LPS group. Hemosiderin and lipofuscin were found in melanomacrophages, but not in testicular melanocytes. Although both the liver and the testes of E. nattereri have pigmented cells, these are distinct in morphology, embryonic origin, and pigmentary substances. These differences may be responsible for the different responses of these cells to the α-MSH analog and LPS administration. © 2013 Elsevier GmbH.

Avaliação das alterações orais em candidatos ao transplante de células-tronco hematopoéticas: identificação de fatores de risco para complicações clínicas

Pós-graduação em Bases Gerais da Cirurgia - FMB

Avaliação do perfil de expressão gênica de células CD34+ e células CD CD133+ isoladas de medula óssea e de sangue de cordão umbilical

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese de nanopartículas de sílica mesoporosa e aplicações como biomaterial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Viroses respiratórias em receptores de transplante de células tronco hemapoéticas e pacientes oncohematológicos

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

Consumo alimentar, estado nutricional e resposta precoce dos fatores de risco relacionados à síndrome metabólica de pacientes submetidos ao transplante de células-tronco hematopoéticas

Pós-graduação em Alimentos e Nutrição - FCFAR

Expressão das metaloproteinases de matriz 2 e 9 em cães com linfoma: associação com fatores prognósticos

Pós-graduação em Cirurgia Veterinária - FCAV

Eletroforetograma de proteínas séricas de cães linfomatosos, submetidos ao protocolo quimioterápico de Madison-Wisconsina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evolução da expressão de CD45+ e do leucograma de cães linfomatosos durante quimioterapia com o protocolo de Madison-Wisconsin

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