Comparison between polyurethanes containing castor oil (Soft Segment) and cancellous bone autograft in the treatment of segmental bone defect induced in rabbits

The aim of this study is to compare polyurethanes containing castor oil (soft segment) in granular form compared to cancellous bone autograft applied to a segmental bone defect. Norfolk adult female rabbits - approximately 13 months of age with a mean body weight of 4.5 kg - are used. In both radial diaphyses, 1 cm osteoperiosteal segmental defects are created. The defect in the left radius is filled with the castor-oil-based polyurethane, and the right one, filled with cancellous bone autograft, collected from the left proximal humerus. The rabbits are euthanazed at 15, 30, 60, and 120 days postsurgery (5 animals/ period), for histological analyses. By radiographic analyses, at these time points, the bone regeneration is more evident and accelerated in the bone defects treated with the cancellous bone autograft. At 120 days postsurgery, the segmental bone defects treated with the cancellous bone autograft are totally reconstituted and remodeled, while the bone defects treated with polyurethane polymer have bone formation of 79%. Histological study shows that the polyurethane acts as a space filler, minimizing the local production of fibrous tissue. No granule degradation, resorption or any inflammatory reaction is detected. Thus, it is possible to conclude that the castor-oil-plant-based polyurethane - in the granule presentation - is biocompatible and osteointegrated, but does not show the same bone regeneration capacity as the cancellous bone autograft. © 2007 SAGE Publications.

Biological response to wollastonite doped α-tricalcium phosphate implants in hard and soft tissues in rats

The biological response following subcutaneous and bone implantation of β-wollastonite(β-W)-doped α-tricalcium phosphate bioceramics in rats was evaluated. Tested materials were: tricalcium phosphate (TCP), consisting of a mixture of α- and β-polymorphs; TCP doped with 5 wt. % of β-W (TCP5W), composed of α-TCP as only crystalline phase; and TCP doped with 15 wt. % of β-W (TCP 15), containing crystalline α-TCP and β-W. Cylinders of 2×1 mm were implanted in tibiae and backs of adult male Rattus norvegicus, Holtzman rats. After 7, 30 and 120 days, animals were sacrificed and the tissue blocks containing the implants were excised, fixed and processed for histological examination. TCP, TCP5W and TCP15W implants were biocompatible but neither bioactive nor biodegradable in rat subcutaneous tissue. They were not osteoinductive in connective tissue either. However, in rat bone tissue β-W-doped α-TCP implants (TCP5W and TCP 15W) were bioactive, biodegradable and osteoconductive. The rates of biodegradation and new bone formation observed for TCP5W and TCP15W implants in rat bone tissue were greater than for non-doped TCP.

Canine transmissible venereal tumors: Aspects related to programmed cell death

Canine transmissible venereal tumor (CTVT) is a neoplasm transmitted by the physical transfer of viable tumor cells by direct contact with injured skin and/or mucous tissue. These cells can transpose across histocompatibility barriers into unrelated hosts. This review focuses on the biology of apoptosis and the interaction of proteins involved in this process, as well as p53, p63 and the antiapoptotic protein Bcl-2. As such, this disease offer unique opportunity to study the biology of transplantable tumours and the interaction of proteins involved in apoptosis process and the prognosis of CTVT.

Genomic and phenotypic profiles of two Brazilian breast cancer cell lines derived from primary human tumors

Breast cancer is the most common type of cancer among women worldwide. Research using breast cancer cell lines derived from primary tumors may provide valuable additional knowledge regarding this type of cancer. Therefore, the aim of this study was to investigate the phenotypic profiles of MACL-1 and MGSO-3, the only Brazilian breast cancer cell lines available for comparative studies. We evaluated the presence of hormone receptors, proliferation, differentiation and stem cell markers, using immunohistochemical staining of the primary tumor, cultured cells and xenografts implanted in immunodeficient mice. We also investigated the ability of the cell lines to form colonies and copy number alterations by array comparative genomic hybridization. Histopathological analysis showed that the invasive primary tumor from which the MACL-1 cell line was derived, was a luminal A subtype carcinoma, while the ductal carcinoma in situ (DCIS) that gave rise to the MGSO-3 cell line was a HER2 subtype tumor, both showing different proliferation levels. The cell lines and the tumor xenografts in mice preserved their high proliferative potential, but did not maintain the expression of the other markers assessed. This shift in expression may be due to the selection of an 'establishment' phenotype in vitro. Whole-genome DNA evaluation showed a large amount of copy number alterations (CNAs) in the two cell lines. These findings render MACL-1 and MGSO-3 the first characterized Brazilian breast cancer cell lines to be potentially used for comparative research. © 2013 Spandidos Publications Ltd. All rights reserved.

Tissue engineering: Using collagen type i matrix for bone healing of bone defects

Among the many tissues in the human body, bone has been considered as a powerful marker for regeneration and its formation serves as a prototype model for tissue engineering based on morphogenesis. Therefore, collagen type I is one of the most useful biomaterials used in tissue engineering as extracellular matrix components capable to promote bone healing. The literature reveals excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenicity, making collagen type I the primary resource in medical applications. Thus, it was also used for tissue engineering including skin replacement, bone substitutes, and artificial blood vessels and valves. The authors describe the treatment of an abscessed apical periodontal cyst and show good outcomes of bone healing, using tissue engineering, as collagen type I matrix. © 2013 by Mutaz B. Habal, MD.

Avaliação da prliferação e apoptose com a utilização de arranjos em matriz de amostra tecidual (Tissue Microarray - TMA) em mastocitomas cutâneos caninos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantification of Biological Tissue and Construction of Patient Equivalent Phantom (Skull and Chest) for Infants (1-5 years old)

Our main purpose in this study was to quantify biological tissue in computed tomography (CT) examinations with the aim of developing a skull and a chest patient equivalent phantom (PEP), both specific to infants, aged between 1 and 5 years old. This type of phantom is widely used in the development of optimization procedures for radiographic techniques, especially in computed radiography (CR) systems. In order to classify and quantify the biological tissue, we used a computational algorithm developed in Matlab (R). The algorithm performed a histogram of each CT slice followed by a Gaussian fitting of each tissue type. The algorithm determined the mean thickness for the biological tissues (bone, soft, fat, and lung) and also converted them into the corresponding thicknesses of the simulator material (aluminum, PMMA, and air). We retrospectively analyzed 148 CT examinations of infant patients, 56 for skull exams and 92 were for chest. The results provided sufficient data to construct a phantom to simulate the infant chest and skull in the posterior anterior or anterior posterior (PA/AP) view. Both patient equivalent phantoms developed in this study can be used to assess physical variables such as noise power spectrum (NPS) and signal to noise ratio (SNR) or perform dosimetric control specific to pediatric protocols.

Immunohistochemical and molecular analysis of caveolin-1 expression in canine mammary tumors

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

Classificação morfológica e imunostoquímica em microarranjo de tecido (TMA) de linfomas não-Hodgkin em cães conforme os critérios da Histological Classification od Hematopoietic Tumors of Domestic Animals (WHO)

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

Biological effects of soft denture reline materials on L929 cells in vitro

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

The role of HLA-G molecule and HLA-G gene polymorphisms in tumors, viral hepatitis, and parasitic diseases

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ki67/KIT double immunohistochemical staining in cutaneous mast cell tumors from Boxer dogs

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

Obturator prostheses versus free tissue transfers: a systematic review of the optimal approach to improving the quality of life for patients with maxillary defects

Patient perspectives on the treatment options for maxillary defects, which include free tissue transfers or obturator prostheses, may help eliminate current uncertainty as to the best choice of treatment plan. The purpose of this systematic review was to evaluate the quality of life (QoL) of patients with maxillary defects who had undergone restoration with obturator prostheses and/or free tissue transfers. A systematic search of Medline/PubMed and Web of Science databases for articles published before April 2015 was performed by 2 independent reviewers. A manual search of articles published from January 2005 to March 2015 was also conducted. Studies published in English that evaluated the QoL in patients with head and neck cancers were included. The Cohen kappa method was used to calculate inter-reviewer agreement. Ten studies were included. The University of Washington Head and Neck Questionnaire (UW-QOL) was most commonly used to measure QoL. The majority of maxillary defects were Class IIa-b. Two studies reported that the global QoL for patients with obturator prostheses is equivalent to or even better than that of other chronic disease populations. One study revealed no significant difference in QoL when the 2 treatment options were compared. The limited data indicate that the QoL of patients treated with obturator prostheses and that of patients free of tumors is similar. Well-designed clinical studies are necessary to draw definitive conclusions about how obturator prostheses compare with free tissue transfers in terms of affecting patient QoL.

Antimicrobial activity of a tissue conditioner combined with a biocide polymer

The characteristics of tissue conditioners support microorganism development that can threaten the health of the dentures user. The object of this study was to evaluate the effect on antimicrobial activity, roughness and wettability surface of a tissue conditioners material combined with the antimicrobial polymer poly (2-tert-butilaminoethyl) methacrylate (PTBAEMA). Specimens of tissue conditioner (Coe Soft(®)) were divided into three groups, according to the concentration of PTBAEMA incorporated (0, 10 and 25%). Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Roughness measurements were made using a Mitutoyo SJ-400, and the mean arithmetic roughness values (Ra) obtained were used for the comparisons. The wettability properties were determined by contact angle measurements. The group containing 25% of PTBAEMA inhibited totally the S. aureus and S. mutans biofilm formation. A significant reduc tion in the S. aureus (Kruskal-Wallis, p = 0,001) and S. mutans (Kruscal-Wallis, p = 0,001) count for 10% PTBAEMA group compared with respective control group. No significant difference was found for C. albicans among PTBAEMA groups and control group (ANOVA, p > 0,05). Incorporating 10 and 25% PTBAEMA increased surface roughness and decreased contact angles (ANOVA and Tukey's post hoc tests, α = 5%). Incorporating 10% PTBAEMA into tissue conditioner increases wettability and roughness of tissue conditioner surface; and decreases the adhesion of S. mutans and S. aureus on material surface, but did not exhibit antimicrobial effect against C. albicans. The PTBAEMA incorporated into tissue conditioner could prevent biofilm formation on elderly patient.

Papiloma de plexo coroide em um cão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)