1
|
Bittencourt GM, Firmiano DM, Fachini RP, Lacaz-Ruiz R, Fernandes AM, Oliveira AL. Application of Green Technology for the Acquisition of Extracts of Araçá (Psidium grandifolium Mart. ex DC.) Using Supercritical CO 2 and Pressurized Ethanol: Characterization and Analysis of Activity. J Food Sci 2019; 84:1297-1307. [PMID: 31116886 DOI: 10.1111/1750-3841.14584] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/01/2019] [Accepted: 02/28/2019] [Indexed: 12/20/2022]
Abstract
Brazil is home to a wide variety of flora, including several lesser known species, such as araçá that were processed in this study using two green technologies consecutively: supercritical fluid extraction (SFE) for nonpolar fraction and pressurized liquid extraction. For polar fraction, the experiments followed a central composite design involving ethanol as solvent, with temperature and static time in each bath as independent variables. Both extracts were analyzed for antioxidant and antimicrobial activities. Total phenolics content (TPC) was determined for all ethanol extracts. In the araçá essential oil (AEO) obtained by SFE, the extraction yield was 2.33%. The three major compounds of AEO were α-pinene (20.75%), p-cymene (20.50%), and o-cymene (20.05%). In ethanol extracts, the high yield (14.49%) was obtained at 74 °C/6 min and the major TPC (136.95 mg GAE/100 g) at 60 °C/9 min. Ethanol extracts presented good antioxidant activity (EC50 = 6.37 mg/mL) at 74 °C/6 min. AEO was unable to reduce DPPH• concentration by 50%. Both extract types presented an inhibitory effect against Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus, while only the ethanol extracts presented effect against Listeria monocytogenes. This work had the aim to present the innovation of the use of a whole typical Brazilian fruit that gives rise to extracts with excellent properties for employment in both the pharmaceutical and food industries.
Collapse
Affiliation(s)
- G M Bittencourt
- Laboratory of High Pressure Technology and Natural Products, Dept. of Food Engineering, Faculty of Animal Science and Food Engineering, Univ. of São Paulo (LTAPPN/ZEA/FZEA/USP), Avenida Duque de Caxias Norte, 225, Mailbox 23, Pirassununga, SP, CEP: 13635-900, Brazil
| | - D M Firmiano
- Laboratory of High Pressure Technology and Natural Products, Dept. of Food Engineering, Faculty of Animal Science and Food Engineering, Univ. of São Paulo (LTAPPN/ZEA/FZEA/USP), Avenida Duque de Caxias Norte, 225, Mailbox 23, Pirassununga, SP, CEP: 13635-900, Brazil
| | - R P Fachini
- Laboratory of High Pressure Technology and Natural Products, Dept. of Food Engineering, Faculty of Animal Science and Food Engineering, Univ. of São Paulo (LTAPPN/ZEA/FZEA/USP), Avenida Duque de Caxias Norte, 225, Mailbox 23, Pirassununga, SP, CEP: 13635-900, Brazil
| | - R Lacaz-Ruiz
- Dept. of Basic Sciences, Faculty of Animal Science and Food Engineering, Univ. of São Paulo (ZAB/FZEA/USP), Avenida Duque de Caxias Norte, 225, Mailbox 23, Pirassununga, SP, CEP: 13635-900, Brazil
| | - A M Fernandes
- Dept. of Veterinary Medicine, Faculty of Animal Science and Food Engineering, Univ. of São Paulo (ZMV/FZEA/USP), Avenida Duque de Caxias Norte, 225, Mailbox 23, Pirassununga, SP, CEP: 13635-900, Brazil
| | - A L Oliveira
- Laboratory of High Pressure Technology and Natural Products, Dept. of Food Engineering, Faculty of Animal Science and Food Engineering, Univ. of São Paulo (LTAPPN/ZEA/FZEA/USP), Avenida Duque de Caxias Norte, 225, Mailbox 23, Pirassununga, SP, CEP: 13635-900, Brazil
| |
Collapse
|
2
|
Silva Filho CI, Oliveira AL, Pereira SCF, de Sá GF, da Luz LL, Alves S. Bright thermal (blackbody) emission of visible light from LnO2 (Ln = Pr, Tb), photoinduced by a NIR 980 nm laser. Dalton Trans 2019; 48:2574-2581. [DOI: 10.1039/c8dt04649b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The light-induced blackbody emission from lanthanide dioxide can improve the solar cell performance by converting NIR photons into bright visible light.
Collapse
Affiliation(s)
| | | | | | | | - L. L. da Luz
- Departamento de Química Funcamental
- UFPE
- Recife
- Brazil
- Centro de Tecnologias Estratégicas do Nordeste
| | - S. Alves
- Programa de Pós-Graduação em Ciência dos Materiais
- UFPE
- Recife
- Brazil
- Departamento de Química Funcamental
| |
Collapse
|
3
|
Dias JR, Baptista-Silva S, Sousa A, Oliveira AL, Bártolo PJ, Granja PL. Biomechanical performance of hybrid electrospun structures for skin regeneration. Mater Sci Eng C Mater Biol Appl 2018; 93:816-827. [PMID: 30274117 DOI: 10.1016/j.msec.2018.08.050] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 08/03/2018] [Accepted: 08/22/2018] [Indexed: 12/19/2022]
Affiliation(s)
- J R Dias
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Centre for Rapid and Sustainable Product Development (CDRsp), Polytechnic Institute of Leiria, Leiria, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.
| | - S Baptista-Silva
- CBQF - Center for Biotechnology and Fine Chemistry, School of Biotechnology, Portuguese Catholic University, Porto, Portugal
| | - A Sousa
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
| | - A L Oliveira
- CBQF - Center for Biotechnology and Fine Chemistry, School of Biotechnology, Portuguese Catholic University, Porto, Portugal
| | - P J Bártolo
- School of Mechanical, Aerospace and Civil Engineering & Manchester Institute of Biotechnology, University of Manchester, UK
| | - P L Granja
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), Porto, Portugal
| |
Collapse
|
4
|
Ferreira HN, Ferreira-Silva JC, Rocha JM, Farras MC, Calixto M, Moura MT, Alvarenga MA, Oliveira AL. Variable Inter-assay Estimation of Sperm DNA Fragmentation In Stallions Classified as Good and Bad Semen Freezers. Cryo Letters 2018; 39:67-71. [PMID: 29734417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
BACKGROUND Semen cryopreservation causes DNA damage, thus requiring continuous monitoring. OBJECTIVE To compare two assays for sperm DNA fragmentation (SDF) from stallions with contrasting semen freezability. MATERIALS AND METHODS Thirteen stallions were classified as good semen freezers (GSF) or bad semen freezers (BSF). Ejaculates were cryopreserved with three diluents. Semen was subject to SDF evaluation using the sperm chromatin structure assay (SCSA) and Halomax after thawing (0 h) and after a 4 h thermoresistance test. RESULTS On semen of BSF, analysis by SCSA was similar between evaluations, but Halomax showed increased SDF at 4 h. The GSF group was similar between time points in both assays. Diluents did not affect SDF, irrespective of the assay. Halomax showed differences for BSF between time points, differently from SCSA. Linear regression did not show any correlation between assays. CONCLUSION The use of Halomax should be encouraged for sperm DNA fragmentation analysis in horse frozen-thawed semen, particularly under field conditions.
Collapse
Affiliation(s)
- H N Ferreira
- Laboratorio de Biotecnologias Reprodutivas, Departamento de Medicina Veterinaria (UFRPE), Recife-PE, Brasil
| | - J C Ferreira-Silva
- Laboratorio de Biotecnologias Reprodutivas, Departamento de Medicina Veterinaria (UFRPE), Recife-PE, Brasil
| | - J M Rocha
- Laboratorio de Biotecnologias Reprodutivas, Departamento de Medicina Veterinaria (UFRPE), Recife-PE, Brasil
| | - M C Farras
- Laboratorio de Biotecnologias Reprodutivas, Departamento de Medicina Veterinaria (UFRPE), Recife-PE, Brasil
| | - M Calixto
- Faculdade Pio Decimo, Aracaju-SE, Brasil
| | - M T Moura
- Laboratorio de Biotecnologias Reprodutivas, Departamento de Medicina Veterinaria (UFRPE), Recife-PE, Brasil
| | - M A Alvarenga
- Laboratorio de Reproduçao Animal, Departamento de Reproduçao Animal e Radiologia Veterinaria da Faculdade de Medicina Veterinaria e Zootecnia (UNESP), Botucatu-SP, Brasil
| | - A L Oliveira
- Laboratorio de Biotecnologias Reprodutivas, Departamento de Medicina Veterinaria (UFRPE), Recife-PE, Brasil.
| |
Collapse
|
5
|
Oliveira AL, Moore Z, O Connor T, Patton D. Accuracy of ultrasound, thermography and subepidermal moisture in predicting pressure ulcers: a systematic review. J Wound Care 2017; 26:199-215. [PMID: 28475447 DOI: 10.12968/jowc.2017.26.5.199] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Our aims were to: establish the clinical significance of ultrasound, thermography, photography and subepidermal moisture (SEM) measurement; determine the accuracy of ultrasound, thermography, photography and SEM measurement in detecting skin/tissue damage; determine the relative accuracy of one of these assessment methods over another; make recommendations for practice pertaining to assessment of early skin/tissue damage. METHOD The following databases, Cochrane Wounds Group Specialised Register, The Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Ovid EMBASE, Elsevier version, EBSCO CINAHL, ClinicalTrials.gov , WHO International Clinical Trials Registry (ICTR) and The EU Clinical Trials Register were searched for terms including; thermography, ultrasound, subepidermal moisture, photograph and pressure ulcer. RESULTS We identified four SEM, one thermography and five ultrasound studies for inclusion in this review. Data analysis indicated that photography was not a method which allowed for the early prediction of PU presence. SEM values increased with increasing tissue damage, with the sacrum and the heels being the most common anatomical locations for the development of erythema and stage I PUs. Thermography identified temperature changes in tissues and skin that may give an indication of early PU development; however the data were not sufficiently robust. Ultrasound detected pockets of fluid/oedema at different levels of the skin that were comparable with tissue damage. Thus, SEM and ultrasound were the best methods for allowing a more accurate assessment of early skin/tissue damage. Using the EBL Critical Appraisal Tool the overall validities of the studies varied between 33.3-55.6%, meaning that there is potential for bias within all the included studies. All of the studies were situated at level IV, V and VII of the evidence pyramid. Although the methodological quality of the studies warrants consideration, these studies showed the potential that SEM and ultrasound have in early PU detection. CONCLUSION SEM and ultrasound are promising in the detection and prediction of early tissue damage and PU presence. However, these methods should be further studied to clarify their potential for use more widely in PU prevention strategies.
Collapse
Affiliation(s)
- A L Oliveira
- Royal College of Surgeons in Ireland Dublin, Dublin Ireland
| | - Z Moore
- Royal College of Surgeons in Ireland Dublin, Dublin Ireland
| | - T O Connor
- Royal College of Surgeons in Ireland Dublin, Dublin Ireland
| | - D Patton
- Royal College of Surgeons in Ireland Dublin, Dublin Ireland
| |
Collapse
|
6
|
Costa DC, Mattioli CC, Silva WS, Takata R, Leme FOP, Oliveira AL, Luz RK. The effect of environmental colour on the growth, metabolism, physiology and skin pigmentation of the carnivorous freshwater catfish Lophiosilurus alexandri. J Fish Biol 2017; 90:922-935. [PMID: 27981570 DOI: 10.1111/jfb.13208] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 10/12/2016] [Indexed: 05/20/2023]
Abstract
The growth, physiology and skin pigmentation of pacamã Lophiosilurus alexandri juveniles were evaluated in an experiment using different tank colours (white, yellow, green, blue, brown and black) over an 80 day period. The tank colours did not cause significant differences to final body mass, total length, survival rate, carcass composition (moisture, crude protein, ash, ether extract, calcium, phosphorus, energy), or to plasma protein, triglyceride and cholesterol values. Haematocrit values, however, were highest for fish kept in white tanks (ANOVA P < 0·05), while the greatest haemoglobin levels were recorded for fish kept in blue and brown tanks (P < 0·01). The concentrations of cortisol (P < 0·001) and glucose (P < 0·01) were the most in fish in the black tanks. Tank colour affected skin pigmentation significantly, with fish in white tanks having the highest values of L* (brightness) and the lowest values in blue and black tanks. L*, however, decreased in all treatments throughout the experiment. C*ab increased significantly over the course of the experiment in fish kept in white tanks. Similar increases of C*ab were recorded in the other treatments but to a lesser extent. The use of black tanks during the cultivation of L. alexandri caused stress and should be avoided. Cultivation in white and yellow tanks produced individuals with a pale skin colour, while cultivation in blue and black tanks resulted in juveniles with a darker and more pigmented skin.
Collapse
Affiliation(s)
- D C Costa
- Universidade Federal de Minas Gerais, Escola de Veterinária, Avenida Antônio Carlos, n° 6627, CEP 30161-970, Brazil
| | - C C Mattioli
- Universidade Federal de Minas Gerais, Escola de Veterinária, Avenida Antônio Carlos, n° 6627, CEP 30161-970, Brazil
| | - W S Silva
- Universidade Federal de Minas Gerais, Escola de Veterinária, Avenida Antônio Carlos, n° 6627, CEP 30161-970, Brazil
| | - R Takata
- Fundação Instituto de Pesca do Estado do Rio de Janeiro, Unidade de Pesquisa e Reprodução de Peixes, Av. Presidente Vargas, 197, Parque de Exposições, CEP 28540-000, Brazil
| | - F O P Leme
- Universidade Federal de Minas Gerais, Escola de Veterinária, Avenida Antônio Carlos, n° 6627, CEP 30161-970, Brazil
| | - A L Oliveira
- Universidade Federal de Minas Gerais, Escola de Veterinária, Avenida Antônio Carlos, n° 6627, CEP 30161-970, Brazil
| | - R K Luz
- Universidade Federal de Minas Gerais, Escola de Veterinária, Avenida Antônio Carlos, n° 6627, CEP 30161-970, Brazil
| |
Collapse
|
7
|
Yan LP, Oliveira JM, Oliveira AL, Reis RL. In vitroevaluation of the biological performance of macro/micro-porous silk fibroin and silk-nano calcium phosphate scaffolds. J Biomed Mater Res B Appl Biomater 2014; 103:888-98. [DOI: 10.1002/jbm.b.33267] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/07/2014] [Accepted: 08/03/2014] [Indexed: 01/03/2023]
Affiliation(s)
- L-P. Yan
- 3B's Research Group-Biomaterials; Biodegradables and Biomimetics; University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine; AvePark, S. Cláudio de Barco 4806-909 Taipas Guimarães Portugal
- ICVS/3B's-PT Government Associate Laboratory; Braga/Guimarães Portugal
| | - J. M. Oliveira
- 3B's Research Group-Biomaterials; Biodegradables and Biomimetics; University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine; AvePark, S. Cláudio de Barco 4806-909 Taipas Guimarães Portugal
- ICVS/3B's-PT Government Associate Laboratory; Braga/Guimarães Portugal
| | - A. L. Oliveira
- 3B's Research Group-Biomaterials; Biodegradables and Biomimetics; University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine; AvePark, S. Cláudio de Barco 4806-909 Taipas Guimarães Portugal
- ICVS/3B's-PT Government Associate Laboratory; Braga/Guimarães Portugal
- CBQF-Center for Biotechnology and Fine Chemistry; School of Biotechnology, Portuguese Catholic University; Porto 4200-072 Portugal
| | - R. L. Reis
- 3B's Research Group-Biomaterials; Biodegradables and Biomimetics; University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine; AvePark, S. Cláudio de Barco 4806-909 Taipas Guimarães Portugal
- ICVS/3B's-PT Government Associate Laboratory; Braga/Guimarães Portugal
| |
Collapse
|
8
|
Oliveira AL, Oliveira Rodrigues FF, Dos Santos RE, Rozenowicz RL, Barbosa de Melo M. GSTT1, GSTM1, and GSTP1 polymorphisms as a prognostic factor in women with breast cancer. Genet Mol Res 2014; 13:2521-30. [PMID: 24535908 DOI: 10.4238/2014.january.22.9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The glutathione S-transferase (GST) family comprises phase-II cellular detoxification enzymes that catalyze the conjugation of chemotherapy drugs to glutathione and act on the apoptotic pathway. The aim of this study was to determine whether polymorphisms of the GSTT1, GSTM1, and GSTP1 genes are associated with different rates of overall survival (OS) and disease-free survival (DFS) after neoadjuvant chemotherapy in the management of locally advanced breast cancer, using either simple or combined analyses, and in relation to the post-therapy axillary lymph node status. Forty women with invasive ductal carcinoma of the breast submitted to neoadjuvant chemotherapy with 5-fluorouracil, epirubicin, and cyclophosphamide were genotyped for GSTT1, GSTM1, and GSTP1. Comparisons were performed for the three genes, either isolated or in pairs, in polymorphic or wild-type combinations. Finally, the OS and DFS of patients were analyzed with respect to axillary lymph node status and with respect to wild-type or polymorphic presentations of each gene. No statistically significant difference in OS and DFS was evident between women with wild-type or polymorphic forms of the genes, either isolated or in pairs, after neoadjuvant chemotherapy. By contrast, after treatment, lymph node-negative women had better OS and DFS only in the presence of polymorphisms of GSTP1, and improved DFS only in the presence of the polymorphic types of GSTT1 and GSTM1 compared to women with positive lymph nodes. The presence of polymorphic forms of GSTP1, GSTM1, and GSTT1 was crucial to conferring better OS and DFS among women with negative axillary lymph nodes.
Collapse
Affiliation(s)
- A L Oliveira
- Departamento de Obstetrícia e Ginecologia, Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, SP, Brasil
| | - F F Oliveira Rodrigues
- Departamento de Obstetrícia e Ginecologia, Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, SP, Brasil
| | - R E Dos Santos
- Departamento de Obstetrícia e Ginecologia, Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, SP, Brasil
| | - R L Rozenowicz
- Departamento de Obstetrícia e Ginecologia, Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, SP, Brasil
| | - M Barbosa de Melo
- Laboratório de Genética Molecular Humana, Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP, Brasil
| |
Collapse
|
9
|
Oliveira AL, Sousa EC, Silva NA, Sousa N, Salgado AJ, Reis RL. Peripheral mineralization of a 3D biodegradable tubular construct as a way to enhance guidance stabilization in spinal cord injury regeneration. J Mater Sci Mater Med 2012; 23:2821-2830. [PMID: 22903600 DOI: 10.1007/s10856-012-4741-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
Spinal cord injuries (SCI) present a major challenge to therapeutic development due to its complexity. Combinatorial approaches using biodegradable polymers that can simultaneously provide a tissue scaffold, a cell vehicle, and a reservoir for sustained drug delivery have shown very promising results. In our previous studies we have developed a novel hybrid system consisting of starch/poly-e-caprolactone (SPCL) semi-rigid tubular porous structure, based on a rapid prototyping technology, filled by a gellan gum hydrogel concentric core for the regeneration within spinal-cord injury sites. In the present work we intend to promote enhanced osteointegration on these systems by pre-mineralizing specifically the external surfaces of the SPCL tubular structures, though a biomimetic strategy, using a sodium silicate gel as nucleating agent. The idea is to create two different cell environments to promote axonal regeneration in the interior of the constructs while inducing osteogenic activity on its external surface. By using a Teflon cylinder to isolate the interior of the scaffold, it was possible to observe the formation of a bone-like poorly crystalline carbonated apatite layer continuously formed only in the external side of the tubular structure. This biomimetic layer was able to support the adhesion of Bone Marrow Mesenchymal Stem Cells, which have gone under cytoskeleton reorganization in the first hours of culture when compared to cells cultured on uncoated scaffolds. This strategy can be a useful route for locally stimulate bone tissue regeneration and facilitating early bone ingrowth.
Collapse
Affiliation(s)
- A L Oliveira
- 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Taipas, Guimarães, Portugal.
| | | | | | | | | | | |
Collapse
|
10
|
Schmidt F, Oliveira AL, Araujo A. Development and Validation of a Neurological Disability Scale for Patients with HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP): The IPEC-1 Scale (P03.258). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p03.258] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
11
|
Oliveira AL, Sun L, Kim HJ, Hu X, Rice W, Kluge J, Reis RL, Kaplan DL. Aligned silk-based 3-D architectures for contact guidance in tissue engineering. Acta Biomater 2012; 8:1530-42. [PMID: 22202909 DOI: 10.1016/j.actbio.2011.12.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 10/24/2011] [Accepted: 12/09/2011] [Indexed: 01/15/2023]
Abstract
An important challenge in the biomaterials field is to mimic the structure of functional tissues via cell and extracellular matrix (ECM) alignment and anisotropy. Toward this goal, silk-based scaffolds resembling bone lamellar structure were developed using a freeze-drying technique. The structure could be controlled directly by solute concentration and freezing parameters, resulting in lamellar scaffolds with regular morphology. Different post-treatments, such as methanol, water annealing and steam sterilization, were investigated to induce water stability. The resulting structures exhibited significant differences in terms of morphological integrity, structure and mechanical properties. The lamellar thicknesses were ∼2.6 μm for the methanol-treated scaffolds and ∼5.8 μm for water-annealed. These values are in the range of those reported for human lamellar bone. Human bone marrow-derived mesenchymal stem cells (hMSC) were seeded on these silk fibroin lamellar scaffolds and grown under osteogenic conditions to assess the effect of the microstructure on cell behavior. Collagen in the newly deposited ECM was found aligned along the lamellar architectures. In the case of methanol-treated lamellar structures, the hMSC were able to migrate into the interior of the scaffolds, producing a multilamellar hybrid construct. The present morphology constitutes a useful pattern onto which hMSC cells attach and proliferate for guided formation of a highly oriented extracellular matrix.
Collapse
Affiliation(s)
- A L Oliveira
- 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal.
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Monteiro PT, Dias PJ, Ropers D, Oliveira AL, Sá-Correia I, Teixeira MC, Freitas AT. Qualitative modelling and formal verification of the FLR1 gene mancozeb response in Saccharomyces cerevisiae. IET Syst Biol 2011; 5:308-16. [PMID: 22010757 DOI: 10.1049/iet-syb.2011.0001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Qualitative models allow understanding the relation between the structure and the dynamics of gene regulatory networks. The dynamical properties of these models can be automatically analysed by means of formal verification methods, like model checking. This facilitates the model-validation process and the test of new hypotheses to reconcile model predictions with the experimental data. RESULTS The authors report in this study the qualitative modelling and simulation of the transcriptional regulatory network controlling the response of the model eukaryote Saccharomyces cerevisiae to the agricultural fungicide mancozeb. The model allowed the analysis of the regulation level and activity of the components of the gene mancozeb-induced network controlling the transcriptional activation of the FLR1 gene, which is proposed to confer multidrug resistance through its putative role as a drug eflux pump. Formal verification analysis of the network allowed us to confront model predictions with the experimental data and to assess the model robustness to parameter ordering and gene deletion. CONCLUSIONS This analysis enabled us to better understand the mechanisms regulating the FLR1 gene mancozeb response and confirmed the need of a new transcription factor for the full transcriptional activation of YAP1. The result is a computable model of the FLR1 gene response to mancozeb, permitting a quick and cost-effective test of hypotheses prior to experimental validation.
Collapse
Affiliation(s)
- P T Monteiro
- INESC-ID/IST, Rua Alves Redol 9, Lisboa 1000-029, Portugal.
| | | | | | | | | | | | | |
Collapse
|
13
|
Jordan SJ, Oliveira AL, Neal AT, Hernandez JN, Branch OH, Rayner JC. Antibodies directed against merozoite surface protein-6 are induced by natural exposure to Plasmodium falciparum in a low transmission environment. Parasite Immunol 2011; 33:401-10. [PMID: 21585398 DOI: 10.1111/j.1365-3024.2011.01299.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Malaria caused by Plasmodium falciparum is a major cause of global infant mortality, and there is currently no licensed vaccine that provides protection against infection or disease. Several P. falciparum vaccine targets have undergone early testing, but many more candidates remain with little data to support their development. Plasmodium falciparum Merozoite Surface Protein 6 (PfMSP6) is a candidate of particular interest because it is a member of the PfMSP3 multi-gene family, raising the possibility that vaccine-induced immune responses could cross-react across multiple family members. However, few immunoepidemiological studies of PfMSP6 have been carried out to measure domain-specific anti-PfMSP6 responses. This study investigated anti-PfMSP6 responses in P. falciparum-infected individuals from the Peruvian Amazon, using two different PfMSP6 N-terminal allele antigens and a single C-terminal domain antigen, and compared the responses with both PfMSP6 genotyping data and anti-PfMSP3 response data that had been previously generated for the same samples. Anti-PfMSP6 responses were detected despite the low transmission setting, but were less frequent and of considerably lower intensity than anti-PfMSP3 responses. There was a positive correlation between anti-PfMSP3 and PfMSP6 responses, suggesting that the possibility that PfMSP3 family antigens could induce cross-reactive responses requires further detailed investigation.
Collapse
Affiliation(s)
- S J Jordan
- William C Gorgas Center for Geographic Medicine, Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | | | | | | | | |
Collapse
|
14
|
Oliveira AL, Rodrigues FFO, Santos RE, Aoki T, Rocha MN, Longui CA, Melo MB. GSTT1, GSTM1, and GSTP1 polymorphisms and chemotherapy response in locally advanced breast cancer. Genet Mol Res 2010; 9:1045-53. [PMID: 20568049 DOI: 10.4238/vol9-2gmr726] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The glutathione S-transferase (GST) family consists of phase II detoxification enzymes that catalyze the conjugation of toxic substances, such as chemotherapeutic agents, to glutathione. We examined whether GSTT1/GSTT1"null", GSTM1/GSTM1"null" and GSTP1Ile105Ile/GSTP1Ile105Val polymorphisms are associated with different response rates to neoadjuvant chemotherapy in the treatment of stage II and III breast cancer. Forty Brazilian women with invasive ductal adenocarcinoma of the breast submitted to neoadjuvant chemotherapy, using 5-fluorouracil, epirubicin and cyclophosphamide, were genotyped for the GSTT1, GSTM1 and GSTP1 genes. Clinical response was assessed by RECIST criteria. Comparisons were made for the three genes alone and in pairs, as polymorphic and as wild-type combinations and polymorphic/wild-type combinations. We analyzed all possible combinations and their response rate. Patients with the GSTT1/GSTP1105Ile combination were found to have a significantly better response than GSTT1"null"/GSTP1105Val (P = 0.0209) and GSTT1/GSTM1 (P = 0.0376) combinations. Analysis of all possible combinations showed the GSTM1"null" polymorphic genotype to be present in four, and the wild-type GSTP1105Ile in six of the combinations associated with the largest number of responding patients. We found that patients with the GSTT1/GSTP1105Ile wild-type combination had a significantly higher response rate to chemotherapy than patients with the respective polymorphic GSTT1"null"/GSTP1105Val combination or patients with the wild-type GSTT1/GSTM1. The six gene combinations associated with the largest number of responding patients were found to contain the wild-type GSTP1105Ile and the polymorphic-type GSTM1"null". These specific combinations were virtually absent in the combinations with few responding patients.
Collapse
Affiliation(s)
- A L Oliveira
- Departamento de Ginecologia e Obstetrícia, Irmandade da Santa Casa de Misericórdia de São Paulo, Faculdade de Ciências Médicas, São Paulo, SP, Brasil.
| | | | | | | | | | | | | |
Collapse
|
15
|
Teixeira MC, Dias PJ, Monteiro PT, Sala A, Oliveira AL, Freitas AT, Sá-Correia I. Refining current knowledge on the yeast FLR1 regulatory network by combined experimental and computational approaches. Mol BioSyst 2010; 6:2471-81. [DOI: 10.1039/c004881j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
16
|
Oliveira AL, Pedro AJ, Arroyo CS, Mano JF, Rodriguez G, Roman JS, Reis RL. Biomimetic Ca-P coatings incorporating bisphosphonates produced on starch-based degradable biomaterials. J Biomed Mater Res B Appl Biomater 2010; 92:55-67. [DOI: 10.1002/jbm.b.31489] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
17
|
Santos MC, Oliveira AL, Viegas-Crespo AM, Vicente L, Barreiros A, Monteiro P, Pinheiro T, Bugalho De Almeida A. Systemic markers of the redox balance in chronic obstructive pulmonary disease. Biomarkers 2008; 9:461-9. [PMID: 15849066 DOI: 10.1080/13547500400024768] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is highly prevalent and its pathogenesis is still not completely clarified. Clinically stable patients (n=21) and healthy subjects (n=24) were studied for blood markers of oxidative injury and antioxidant status. The plasma concentration of protein carbonyls was significantly increased in COPD patients, both ex-smokers (0.76 +/- 0.28 nmol mg(-1)) and smokers (0.99 +/- 020 nmol mg(-1)) versus controls (0.49 +/- 0.14 nmol mg(-1)) . The concentration of total thiols was slightly enhanced in plasma of the COPD patients (ex-smokers 492 +/- 23 micromol 1(-1) and smokers 505 +/- 36 micromol 1(-1) versus controls 450 +/- 67 micromol 1(-1); p < 0.05). The activity of the antioxidant enzyme superoxide dismutase was increased in erythrocytes (activity in U g(-1) haemoglobin; ex-smokers 4460 +/- 763 and smokers 4114+/- 1060 versus 3015 +/- 851 in controls; p > 0.01), while glutathione peroxidase activity was decreased in total blood (activity in U g(-1) haemoglobin: ex-smokers 27 +/- 9 and smokers 23 +/- 9 versus 47 +/- 25; p < 0.01). Lower levels of selenium in plasma were also found for COPD patients (concentration in mg 1(-1): ex-smokers 0.030 +/- 0.019 and smokers 0.032 +/- 0.024 versus 0.058 +/- 0.023 in controls; p < 0.01), being more evident in those with very low levels of arterial oxygen pressure. In addition, the levels of potassium and rubidium were increased in blood cells of the patient group. All these changes might reflect oxidant damage and an altered electrolytic homeostasis, and can be interpreted as markers of COPD rather than as indicators of smoking habits.
Collapse
Affiliation(s)
- M C Santos
- Departamento de Química e Bioquímica, Faculdade de Ciencias, University of Lisbon, Lisbon, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
18
|
|
19
|
Rodrigues FFO, Santos RE, Melo MB, Silva MALG, Oliveira AL, Rozenowicz RL, Ulson LB, Aoki T. Correlation of polymorphism C3435T of the MDR-1 gene and the response of primary chemotherapy in women with locally advanced breast cancer. Genet Mol Res 2008; 7:177-83. [PMID: 18393221 DOI: 10.4238/vol7-1gmr400] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Primary chemotherapy is a useful strategy for the treatment of locally advanced breast cancer and therefore allows in vivo evaluation of the action of cytotoxic drugs and the possibility of accomplishing conservative breast surgeries, as well as the early treatment of metastasis. Mechanisms of resistance to the drugs include the action of protein associated with the efflux of drugs from the intracellular environment hindering their activity; one of the most studied proteins is P-glycoprotein codified by the MDR-1 gene. The presence of polymorphisms can determine different physiological actions of these proteins, intervening with the response of the drug's action. We evaluated the presence of single nucleotide polymorphism (SNP) C3435T of the MDR-1 gene and its correlation with the response to primary chemotherapy using the RECIST criteria. Forty-one Brazilian women with stages II and III breast cancer using the PCR-RFLP analysis were evaluated. Thirty-three patients with the SNP genotype (TT and CT) and eight patients with the wild genotype (CC) were found; there was no statistically significant correlation between the diverse genotypes and the clinical and pathological responses according to the Cramer correlation coefficient (V = 0.14). The parameters: nuclear and histological degree, and estrogens, progesterone and c-erb B2 receptors did not demonstrate a statistical correlation with the SNP C3435T. Patients with complete pathological response (12.5%) showed only the polymorphic genotype and not the wild genotype. The characteristics of miscegenation in our population could explain the absence of the characterization of a sub-group of individuals where the presence of the polymorphic genotype influenced the response to the primary chemotherapy.
Collapse
Affiliation(s)
- F F O Rodrigues
- Departamento de Obstetrícia e Ginecologia, Santa Casa de São Paulo, Faculdade de Ciências Médicas, São Paulo, SP, Brasil.
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Zorron R, Maggioni LC, Pombo L, Oliveira AL, Carvalho GL, Filgueiras M. NOTES transvaginal cholecystectomy: preliminary clinical application. Surg Endosc 2007; 22:542-7. [PMID: 18027043 DOI: 10.1007/s00464-007-9646-5] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 08/30/2007] [Accepted: 09/22/2007] [Indexed: 12/16/2022]
Abstract
BACKGROUND Natural orifice translumenal endoscopic surgery (NOTES) is an emerging concept in the recent literature that could lead to potential benefits in clinical applications. Restricted to animal experiments, however, human procedures have not yet been published. Because of the technical and ethical challenges involved in perforation and closure of a healthy organ-as is also seen in operating via the transgastric route-and because of the lack of understanding of the physiopathology and infection risk with these approaches, they have not been applied in the clinical setting. Thus the present study, based on previous animal experiments, describes preliminary clinical application in four cases of transvaginal NOTES cholecystectomy, and discusses safety, feasibility, and potential benefits of the method. METHODS Preliminary acute and survival animal experiments developed by the NOTES Research Group at our institution solved such technical problems for transvaginal NOTES as spatial orientation, insufflation, and instrumentation, making possible the introduction of NOTES as a clinical application. The trials were approved by ethics committee of our institution, and informed consent was obtained from all patients. Since 13 March 2007, four female patients with elective surgical indication for cholecystectomy have undergone transvaginal NOTES cholecystectomy. All intraoperative and postoperative parameters were documented. Vaginal access was achieved under direct vision with conventional instruments, and a 2-channel colonoscope was inserted into the abdominal cavity. After endoscopic insufflation to achieve pneumoperitoneum with CO(2), instruments were inserted through and alongside a colonoscope, allowing successful NOTES cholecystectomy in all patients, with vaginal extraction of the gallbladder. The vaginal wound was closed by direct vision using conventional instruments. RESULTS The procedure was successful in all patients, with operative time of 45-115 min. Patients experienced low need for postoperative analgesia. Free oral intake was permitted 2 h after the procedure. There were no postoperative complications, and patients were discharged, according to the study protocol, 48 h after the procedure. CONCLUSIONS Preliminary results showed the feasibility and safety of the transvaginal NOTES method in this small initial study population. The technique, developed in our institution, and not transgastric NOTES, may be the preferred approach to serve as the basis for clinical studies.
Collapse
Affiliation(s)
- R Zorron
- Department of Surgery, University Hospital Teresopolis HCTCO-FESO, Av. Américas 13554 BL.1 AP.207 Barra da Tijuca, Rio de Janeiro, Brazil.
| | | | | | | | | | | |
Collapse
|
21
|
Oliveira AL, de Souza M, Carvalho-Dias VMH, Ruiz MA, Silla L, Tanaka PY, Simões BP, Trabasso P, Seber A, Lotfi CJ, Zanichelli MA, Araujo VR, Godoy C, Maiolino A, Urakawa P, Cunha CA, de Souza CA, Pasquini R, Nucci M. Epidemiology of bacteremia and factors associated with multi-drug-resistant gram-negative bacteremia in hematopoietic stem cell transplant recipients. Bone Marrow Transplant 2007; 39:775-81. [PMID: 17438585 DOI: 10.1038/sj.bmt.1705677] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The incidence of Gram-negative bacteremia has increased in hematopoietic stem cell transplant (HSCT) recipients. We prospectively collected data from 13 Brazilian HSCT centers to characterize the epidemiology of bacteremia occurring early post transplant, and to identify factors associated with infection due to multi-drug-resistant (MDR) Gram-negative isolates. MDR was defined as an isolate with resistance to at least two of the following: third- or fourth-generation cephalosporins, carbapenems or piperacillin-tazobactam. Among 411 HSCT, fever occurred in 333, and 91 developed bacteremia (118 isolates): 47% owing to Gram-positive, 37% owing to Gram-negative, and 16% caused by Gram-positive and Gram-negative bacteria. Pseudomonas aeruginosa (22%), Klebsiella pneumoniae (19%) and Escherichia coli (17%) accounted for the majority of Gram-negative isolates, and 37% were MDR. These isolates were recovered from 20 patients, representing 5% of all 411 HSCT and 22% of the episodes with bacteremia. By multivariate analysis, treatment with third-generation cephalosporins (odds ratio (OR) 10.65, 95% confidence interval (CI) 3.75-30.27) and being at one of the hospitals (OR 9.47, 95% CI 2.60-34.40) were associated with infection due to MDR Gram-negative isolates. These findings may have important clinical implications in the decision of giving prophylaxis and selecting the empiric antibiotic regimen.
Collapse
Affiliation(s)
- A L Oliveira
- Hospital Universitário, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Oliveira AL, Malafaya PB, Costa SA, Sousa RA, Reis RL. Micro-computed tomography (micro-CT) as a potential tool to assess the effect of dynamic coating routes on the formation of biomimetic apatite layers on 3D-plotted biodegradable polymeric scaffolds. J Mater Sci Mater Med 2007; 18:211-23. [PMID: 17323152 DOI: 10.1007/s10856-006-0683-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Accepted: 10/19/2006] [Indexed: 05/14/2023]
Abstract
This work studies the influence of dynamic biomimetic coating procedures on the growth of bone-like apatite layers at the surface of starch/polycaprolactone (SPCL) scaffolds produced by a 3D-plotting technology. These systems are newly proposed for bone Tissue Engineering applications. After generating stable apatite layers through a sodium silicate-based biomimetic methodology the scaffolds were immersed in Simulated Body Fluid solutions (SBF) under static, agitation and circulating flow perfusion conditions, for different time periods. Besides the typical characterization techniques, Micro-Computed Tomography analysis (micro-CT) was used to assess scaffold porosity and as a new tool for mapping apatite content. 2D histomorphometric analysis was performed and 3D virtual models were created using specific softwares for CT reconstruction. By the proposed biomimetic routes apatite layers were produced covering the interior of the scaffolds, without compromising their overall morphology and interconnectivity. Dynamic conditions allowed for the production of thicker apatite layers as consequence of higher mineralizing rates, when comparing with static conditions. micro-CT analysis clearly demonstrated that flow perfusion was the most effective condition in order to obtain well-defined apatite layers in the inner parts of the scaffolds. Together with SEM, this technique was a useful complementary tool for assessing the apatite content in a non-destructive way.
Collapse
Affiliation(s)
- A L Oliveira
- 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, Univ. of Minho, Campus Gualtar, 4710 Braga, Portugal.
| | | | | | | | | |
Collapse
|
23
|
Oliveira AL, Reis RL, Li P. Strontium-substituted apatite coating grown on Ti6Al4V substrate through biomimetic synthesis. J Biomed Mater Res B Appl Biomater 2007; 83:258-65. [PMID: 17455267 DOI: 10.1002/jbm.b.30791] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
During the last few years Strontium has been shown to have beneficial effects when incorporated at certain doses in bone by stimulating bone formation. It is believed that its presence locally at the interface between an implant and bone will enhance osteointegration and therefore, ensure the longevity of a joint prosthesis. In this study we explore the possibility of incorporating Sr into nano-apatite coatings prepared by a solution-derived process according to an established biomimetic methodology for coating titanium based implants. The way this element is incorporated in the apatite structure and its effects on the stereochemistry and morphology of the resulting apatite layers was investigated, as well as its effect in the mineralization kinetics. By using the present methodology it was possible to incorporate increasing amounts of Sr in the apatite layers. Sr was found to incorporate in the apatite layer through a substitution mechanism by replacing Ca in the apatite lattice. The presence of Sr in solution induced an inhibitory effect on mineralization, leading to a decrease in the thickness of the mineral layers. The obtained Sr-substituted biomimetic coatings presented a bone-like structure similar to the one found in the human bone and therefore, are expected to enhance bone formation and osteointegration.
Collapse
Affiliation(s)
- A L Oliveira
- DePuy Orthopaedics, Inc., 700 Orthopaedics Drive, Warsaw, Indiana 46581, USA
| | | | | |
Collapse
|
24
|
Chim H, Hutmacher DW, Chou AM, Oliveira AL, Reis RL, Lim TC, Schantz JT. A comparative analysis of scaffold material modifications for load-bearing applications in bone tissue engineering. Int J Oral Maxillofac Surg 2006; 35:928-34. [PMID: 16762529 DOI: 10.1016/j.ijom.2006.03.024] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Accepted: 03/15/2006] [Indexed: 11/23/2022]
Abstract
To facilitate optimal application of appropriate scaffold architectures for clinical trials, there is a need to compare different scaffold modifications under similar experimental conditions. In this study was assessed the effectiveness of poly-e-caprolactone (PCL) scaffolds fabricated by fused deposition modelling (FDM), with varying material modifications, for the purposes of bone tissue engineering. The incorporation of hydroxyapatite (HA) in PCL scaffolds, as well as precalcification through immersion in a simulated body fluid (SBF) to produce a biomimetic apatite coating on the scaffolds, was assessed. A series of in vitro studies spanning 3 weeks as well as in vivo studies utilizing a subcutaneous nude mouse model were carried out. PCL and HA-PCL scaffolds demonstrated increasing tissue growth extending throughout the implants, as well as superior mechanical strength and mineralization, as evidenced by X-ray imaging after 14 weeks in vivo. No significant difference was found between PCL and HA-PCL scaffolds. Precalcification with SBF did not result in increased osteoconductivity and cell proliferation as previously reported. Conversely, tensile forces exerted by tissue sheets bridging adjacent struts of the PCL scaffold caused flaking of the apatite coating that resulted in impaired cell attachment, growth and mineralization. The results suggest that scaffolds fabricated by FDM may have load-bearing applications.
Collapse
Affiliation(s)
- H Chim
- Division of Plastic and Reconstructive Surgery, National University Hospital, Singapore 119074, Singapore
| | | | | | | | | | | | | |
Collapse
|
25
|
Oliveira AL, Pazzagli L, Pantera B, Cappugi G, Benedetti CE, Spisni A, Pertinhez TA. 1H, 15N and 13C Resonance assignments of cerato-platanin, a phytotoxic protein from Ceratocystis fimbriata. J Biomol NMR 2006; 36 Suppl 1:50. [PMID: 16819587 DOI: 10.1007/s10858-006-9023-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- A L Oliveira
- Dept. Experimental Medicine, University of Parma, Parma, 43100, Italy
| | | | | | | | | | | | | |
Collapse
|
26
|
Oliveira AL, Mano JF, Román JS, Reis RL. Study of the influence of β-radiation on the properties and mineralization of different starch-based biomaterials. J Biomed Mater Res B Appl Biomater 2005; 74:560-9. [PMID: 15906388 DOI: 10.1002/jbm.b.30260] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this work, the effects of beta-radiation are assessed, for the first time, on starch-based biodegradable polymers, with the aim of using it as an alternative sterilization process to the previously studied sterilization methods. Different doses of radiation were used in order to investigate the possibility of using this sterilization technique as a treatment to tailor the surface and bulk properties (namely mechanical) of these polymers. The as-treated substrates were characterized by water-uptake measurements and contact angle (theta) measurements. The mechanical properties of the materials were characterized by tensile tests by means of ultimate tensile strength (UTS) and strain at break (epsilon). The fracture of the surfaces was observed by scanning electron microscopy (SEM). Dynamic mechanical analysis (DMA) was also used to characterize the viscolelastic behavior of the irradiated materials. The main effect of sterilization with beta-radiation over the starch-based polymers seems to be a surface modification by an increase of the hydrophilicity. Nevertheless, because beta-radiation did not significantly affect the mechanical properties, it can be regarded as an effective way of modifying the surface for applications were more hydrophilic surfaces are desirable.
Collapse
Affiliation(s)
- A L Oliveira
- 3B's Research Group - Biomaterials, Biodegradables & Biomimetics, University of Minho, Campus de Gualtar, Braga, Portugal.
| | | | | | | |
Collapse
|
27
|
Soares LAL, Oliveira AL, Ortega GG, Petrovick PR. Development and validation of a LC-method for determination of catechin and epicatechin in aqueous extractives from leaves of Maytenus ilicifolia. J Pharm Biomed Anal 2004; 36:787-90. [PMID: 15533671 DOI: 10.1016/j.jpba.2004.08.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 08/24/2004] [Accepted: 08/27/2004] [Indexed: 11/30/2022]
Abstract
A reverse phase-LC method was developed and validated for separation and quantification of catechin and epicatechin in aqueous extractives from leaves of Maytenus ilicifolia. The analysis was performed using a C(18) column with acetic acid-acetonitrile gradient elution. The detection was carried out by UV at 280 nm and the peak identification was based on the retention times and by co-chromatography with reference substances. High coefficients of determination were achieved for both catechin and epicatechin peaks from the standard solutions (0.9996 and 0.9999), as well as from extractives (0.9981 and 0.9982, respectively). The method showed good repeatability (R.S.D. <1.5%), reproducibility (R.S.D. <5%) and good accuracy for both catechin and epicatechin peaks (101.4%, R.S.D. = 1.18% and 100.6%, R.S.D. = 2.07%, respectively).
Collapse
Affiliation(s)
- L A L Soares
- Departamento de Farmácia, Universidade Federal do Rio Grande do Norte, Av. Cordeiro de Farias, s/n, 59010-180, Natal, RN, Brazil.
| | | | | | | |
Collapse
|
28
|
Oliveira AL, Reis RL. Pre-mineralisation of starch/polycrapolactone bone tissue engineering scaffolds by a calcium-silicate-based process. J Mater Sci Mater Med 2004; 15:533-540. [PMID: 15332631 DOI: 10.1023/b:jmsm.0000021134.34651.d3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This work describes a new methodology to produce bioactive coatings on the surface of starch-based biodegradable polymers or other degradable polymeric biomaterials. As an alternative to the more typical bioactive glass precursors, a calcium silicate gel is being employed as a nucleating agent, for inducing the biomimetic formation of a calcium-phosphate (Ca-P) layer. The method has the advantage of being able to coat efficiently both compact materials and porous 3-D architectures aimed at being used on tissue replacement applications and as bone tissue engineering scaffolds. This treatment is also very effective in reducing the incubation periods, being possible to observe the formation of an apatite-like layer, only after 12 h of immersion in a simulated body fluid (SBF). The apatite coatings formed on the compact surfaces or along the fibres of a fibre mesh scaffold structure made from a starch/polycrapolactone blend (SPCL) were analysed and compared in terms of morphology, chemical composition and structure. After the first days of SBF immersion, the apatite-like films exhibit the typical cauliflower like morphology. With increasing immersion times, these films exhibited a partially amorphous nature and the Ca/P ratios became very closer to the value attributed to hydroxyapatite (1.67). It was possible to fully pre-mineralise the SPCL scaffolds and simultaneously to keep the porous morphology of the fibre-bonded scaffold.
Collapse
Affiliation(s)
- A L Oliveira
- Department of Polymer Engineering, University of Minho, Campus de Gualtar, Guimarães, Portugal.
| | | |
Collapse
|
29
|
Oliveira AL, Malafaya PB, Reis RL. Sodium silicate gel as a precursor for the in vitro nucleation and growth of a bone-like apatite coating in compact and porous polymeric structures. Biomaterials 2003; 24:2575-84. [PMID: 12726711 DOI: 10.1016/s0142-9612(03)00060-7] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the present work, a new methodology to produce bioactive coatings on the surface of starch-based biodegradable polymers or other polymeric biomaterials is proposed. A sodium silicate gel is employed as an alternative nucleating agent to the more typical bioactive glasses for inducing the formation of a calcium-phosphate (Ca-P) layer. The method has the advantage of being able to coat efficiently both compact materials and porous 3D architectures aimed at being used on tissue replacement applications and as tissue engineering scaffolds. By means of this treatment, it is possible to observe the formation of an apatite-like layer, only after 6 hours of simulated body fluid immersion. For the porous materials, this layer could also be observed inside the pores, clearly covering the cell walls. Furthermore, an increase of the surface hydrophilicity (higher amount of polar groups in the surface) might contribute to the formation of silanol groups that also act as apatite inductors. After 30 days of SBF immersion, the apatite-like films exhibit a partially amorphous nature and the Ca/P ratios became much closer to the value attributed to hydroxyapatite (1.67). The obtained results are very promising for the development of cancellous bone replacement materials and for pre-calcifying bone tissue engineering scaffolds.
Collapse
Affiliation(s)
- A L Oliveira
- Department of Polymer Engineering, University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal.
| | | | | |
Collapse
|
30
|
Sousa RA, Oliveira AL, Reis RL, Cunha AM, Bevis MJ. Bi-composite sandwich moldings: processing, mechanical performance and bioactive behavior. J Mater Sci Mater Med 2003; 14:385-397. [PMID: 15348441 DOI: 10.1023/a:1023294615866] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Two composite systems composed of high-density polyethylene (HDPE) filled with hydroxyapatite (HA) and carbon fiber (C fiber) were compounded in a co-rotating twin screw extruder and subsequently molded in a two component injection molding machine in order to produce test bars with a sandwich-like morphology. These moldings are based on a HDPE/HA composite outer layer and a HDPE/C fiber composite core. The mechanical performance of the obtained specimens was assessed by tensile and impact testing. The fracture surfaces were observed by scanning electron microscopy (SEM) and optical reflectance microscopy was used to characterize the morphology within the moldings. In order to study the bioactivity of the molded specimens, the samples were immersed for different periods of time up to 30 days in a simulated-body fluid (SBF) with an ion composition similar to human blood plasma. After each immersion period, the surfaces of the specimens were characterized by SEM. The chemical composition and the structure of the deposited films were studied by electron dispersive spectroscopy (EDS) and thin-film X-ray diffraction (TF-XRD). The evolution of the elemental concentrations in the SBF solution was determined by induced coupled plasma emission (ICP) spectroscopy. Bi-composite moldings featuring a sandwich-like morphology were successfully produced. These moldings present a high stiffness as a result of the C fiber reinforcement present in the molding core. Furthermore, as a result of the HA loading, the sandwich moldings exhibit a clear in vitro bioactive behavior under simulated physiological conditions, which indicates that an in vivo bone-bonding behavior can be expected for these materials.
Collapse
Affiliation(s)
- R A Sousa
- Department of Polymer Engineering, University of Minho, 4800-058 Guimarães, Portugal.
| | | | | | | | | |
Collapse
|
31
|
Oliveira AL, Alves CM, Reis RL. Cell adhesion and proliferation on biomimetic calcium-phosphate coatings produced by a sodium silicate gel methodology. J Mater Sci Mater Med 2002; 13:1181-1188. [PMID: 15348663 DOI: 10.1023/a:1021106525097] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The present study describes a methodology to produce bioactive coatings on the surface of starch based biodegradable polymers or other polymeric biomaterials. As an alternative to the more typical bioactive glass percursors, a sodium silicate gel is being employed as a nucleating agent, for inducing the formation of a calcium-phosphate (Ca-P) layer. The method has the advantage of being able to coat efficiently both compact materials and porous 3D architectures aimed at being used on tissue replacement applications and as bone tissue engineering scaffolds. This treatment is also very effective in reducing the incubation periods, being possible to observe the formation of an apatite-like layer, only after 6 h of immersion in a simulated body fluid (SBF). The influence of the SBF concentration on the formation of the apatite coating was also studied. The apatite coatings formed under different conditions were analyzed and compared in terms of morphology, chemical composition and structure. After the first days of SBF immersion, the apatite-like films exhibit the typical cauliflower like morphology. With increasing immersion times, these films exhibited a partially amorphous nature and the Ca/P ratios became very closer to the value attributed to hydroxyapatite (1.67). The obtained results are very promising for pre-calcifying bone tissue engineering scaffolds. Therefore, in order to study cell behavior and response to these apatite coatings, adhesion, morphology, and proliferation of a human osteoblast cell line (SaOS-2) was also analyzed after being cultured in the coatings formed after 15 days of immersion in SBF. Results indicate a good correlation between crystallinity of the apatite like coatings formed in these conditions and respective cell spreading and morphology. In general, higher cell proliferation was observed for higher crystalline Ca-P coatings.
Collapse
Affiliation(s)
- A L Oliveira
- Department of Polymer Engineering, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
| | | | | |
Collapse
|
32
|
Manco L, Oliveira AL, Gomes C, Granjo A, de Jesus Trovoada M, Ribeiro ML, Abade A, Amorim A. Population genetics of four PKLR intragenic polymorphisms in Portugal and São Tomé e Príncipe (Gulf of Guinea). Hum Biol 2001; 73:467-74. [PMID: 11459427 DOI: 10.1353/hub.2001.0037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Four intragenic PKLR polymorphisms [1705A/C, 1738C/T. T10/19, and (ATT)n microsatellite] were studied in normal population samples of Central Portugal and São Tomé e Príncipe, a small archipelago located in the Gulf of Guinea, West Africa. For all loci, the observed genotype distributions do not deviate from Hardy-Weinberg equilibrium. The allele frequencies found in the Portuguese population are similar to those previously described in Caucasian populations. Mother-child pair analysis for the (ATT)n microsatellite does not show deviations to the Mendelian rules. In São Tomé e Príncipe the biallelic polymorphisms 1705A/C, 1738C/T, and T10/19 presented inverse allelic frequencies when compared with the Portuguese population. Two new alleles were found at the (ATT)n microsatellite. Significant statistical differences were found between both populations. The results showed that São Tomeans had higher haplotype diversity and lower linkage disequilibrium among the polymorphic sites. The PKLR intragenic polymorphisms, commonly used in haplotype analysis with the gene mutations in PK-deficient patients, can thus be successfully employed in anthropological genetics.
Collapse
Affiliation(s)
- L Manco
- Departamento de Antropologia, Universidade de Coimbra, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
The rate of axonal regeneration, after sciatic nerve lesion in adult C57BL/6J mice, is reduced when compared to other isogenic strains. It was observed that such low regeneration was not due just to a delay, since neuronal death was observed. Two general mechanisms of cell death, apoptosis and necrosis, may be involved. By using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technique, we demonstrated that a large number of sensory neurons, as well as satellite cells found in the dorsal root ganglia, were intensely labeled, thus indicating that apoptotic mechanisms were involved in the death process. Although almost no labeled neurons or satellite cells were observed one week after transection, a more than ten-fold increase in TUNEL labeling was detected after two weeks. The results obtained with the C57BL/6J strain were compared with those of the A/J strain, which has a much higher peripheral nerve regeneration potential. In A/J mice, almost no labeling of sensory neurons or satellite cells was observed after one or two weeks, indicating the absence of neuronal loss. Our data confirm previous observations that approximately 40% of C57BL/6J sensory neurons die after sciatic nerve transection, and indicate that apoptotic events are involved. Also, our observations reinforce the hypothesis that the low rate of axonal regeneration occurring in C57BL/6J mice may be the result of a mismatch in the timing of the neurons need for neurotrophic substances, and production of the latter by non-neuronal cells in the distal stump.
Collapse
Affiliation(s)
- A L Oliveira
- Departamento de Anatomia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil.
| |
Collapse
|
34
|
Abstract
Peripheral axonal regeneration was investigated in adult male mice of the C57BL/6J (C), BALB/cJ (B) and A/J (A) strains and in their F1 descendants using a predegenerated nerve transplantation model. Four types of transplants were performed: 1) isotransplants between animals of the C, B and A strains; 2) donors of the C strain and recipients of the C x B and C x A breeding; 3) donors of the B strain and recipients of the C x B breeding, and 4) donors of the A strain and recipients of the C x A breeding. Donors had the left sciatic nerve transected and two weeks later a segment of the distal stump was transplanted into the recipient. Four weeks after transplantation the regenerated nerves were used to determine the total number of regenerated myelinated fibers (TMF), diameter of myelinated fibers (FD) and myelin thickness (MT). The highest TMF values were obtained in the groups where C57BL/6J mice were the donors (C to F1 (C x B) = 4658 +/- 304; C to F1 (C x A) = 3899 +/- 198). Also, A/J grafts led to a significantly higher TMF (A to F1 (C x A) = 3933 +/- 565). Additionally, isotransplant experiments showed that when the nerve is previously degenerated, C57BL/6J mice display the largest number of myelinated fibers (C to C = 3136 +/- 287; B to B = 2759 +/- 170, and A to A = 2835 +/- 239). We also observed that when C57BL/6J was the graft donor, FD was the highest and MT did not differ significantly when compared with the other groups. These morphometric results reinforce the idea that Schwann cells and the nerve environment of C57BL/6J provide enough support to the regenerative process. In this respect, the present results support the hypothesis that the non-neuronal cells, mainly Schwann cells, present in the sciatic nerve of C57BL/6J mice are not the main limiting factor responsible for low axonal regeneration.
Collapse
Affiliation(s)
- A L Oliveira
- Departamento de Anatomia, Universidade Estadual de Campinas, Campinas, SP, Brasil.
| | | |
Collapse
|
35
|
Abstract
After ventral root avulsion, a large percentage of the wounded spinal motoneurons die within 2 weeks. Neuronal death is preceded by a series of morphological and physiological changes probably as a result of both apoptotic and necrotic mechanisms. Associated with neuronal death, inflammation develops in the wounded area, resulting in additional neuronal loss as well as the degeneration of fibers from different tracts of the ventral and lateral funiculi. In the present study we tested the neuroprotective and local anti-inflammatory effects of monosialoganglioside (GM-1) after an initial 150 mg/kg body weight dose, followed by the daily administration of 100 mg/kg body weight for 2 weeks. The results showed a statistically significant enhancement of surviving motoneurons which showed good morphological preservation. Also, GM-1 treatment reduced by less then a half, the number of degenerating fibers into the ventral and lateral funiculi. Taken together, our results indicate that the administration of GM-1 in high doses during the critical period of motoneuron death after avulsion is neuroprotective, and diminishes local inflammation.
Collapse
Affiliation(s)
- A L Oliveira
- Department of Anatomy, State University of Campinas, Unicamp 13083-970, Cp. 6109, SP, Campinas, Brazil.
| | | |
Collapse
|
36
|
Abstract
The influence of aging on Schwann cell (SC) proliferation, migration and viability was studied in vitro. SCs were cultured in Ham F-10 medium enriched with 20% fetal calf serum (FCS), 40% FCS or collagen I gel plus 20% FCS. The migration of adult mice derived SCs was stimulated with FCS and collagen. With aging, SC migration, multiplication and viability decreased, indicating that ideal culturing conditions should be adjusted.
Collapse
Affiliation(s)
- A R Santos
- Department of Cell Biology, State University of Campinas-UNICAMP, CP 6109, CEP 13089-970, SP, Campinas, Brazil
| | | | | | | |
Collapse
|
37
|
Fonseca LF, Oliveira AL. [Infantile spasms: experience in 13 cases]. Arq Neuropsiquiatr 2000; 58:512-7. [PMID: 10920415 DOI: 10.1590/s0004-282x2000000300018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infantile spasms are typical crisis found in the childhood being a serious pathology with an obscure prognosis. We present the experience of the Service of Neuropediatrics in the Pediatric General Center, Belo Horizonte - Brasil, during the year of 1997, with a review of the literature about. After appropriate propaedeutics, were found 12 cases considered symptomatics and 1 case cryptogenic. All these cases were treated with ACTH during 6 weeks associated with oral antiepileptic drugs in mono or polytherapy for maintenance. We had excellent results using ACTH at the beginning of the treatment, obtaining good results in all of the cases with some side effects that were not important enough to interrupt the treatment. However, there was a recurrence rate of 55% and vigabatrin was used as second option, controlling 4 of the 5 cases. All the cases showed retardation of the neuropsychomotor development.
Collapse
Affiliation(s)
- L F Fonseca
- Serviço de Neurologia Infantil, Centro Geral de Pediatria, Fundação Hospitalar do Estado de Minas Gerais, Belo Horizonte, Brasil
| | | |
Collapse
|
38
|
Oliveira AL, Elvira C, Reis RL, Vázquez B, San Román J. Surface modification tailors the characteristics of biomimetic coatings nucleated on starch-based polymers. J Mater Sci Mater Med 1999; 10:827-835. [PMID: 15347960 DOI: 10.1023/a:1008900428325] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This work describes the influence of surface pretreatments over the nucleation and growth of an apatite layer, formed by a biomimetic process, on which a bioactive glass is used as a precursor of the calcium-phosphate (Ca-P) formation on the materials surface. SEVA-C, a corn starch-based biodegradable blend, was used as substrate. The surfaces were pretreated during various periods by: (i) physical methods, namely ultraviolet radiation (u.v.), and over exposure to ethylene oxide sterilization (EtO); and (ii) chemical methods, namely potassium hydroxide (KOH) and acetic anhydride (CH3CO)2 etchings. The surface modifications, performed before the production of the biomimetic coatings, resulted in a faster formation of Ca-P nuclei during the first stages of SBF immersion, particularly in the case of the KOH etching. In this case, it was possible to observe a decrease in the average surface roughness, as measured by laser profilometry, and an increase of the hydrophilicity of the material, which was evident from a clear increment in the water-uptake ability and quantified by contact angle measurements. With this treatment it was possible not only to reduce the induction period for the formation of a well defined and dense apatite-like layer, as observed by scanning electron microscopy (SEM), but also to improve the adhesion of the Ca-P layer to the substrate, as confirmed by the adhesion strength tests. For all the studied pre-treatments, the composition of the films, analyzed by energy dispersive spectroscopy (EDS) and identified by thin-film X-ray diffraction (TF-XRD), seems to be very similar to that of human bone apatites.
Collapse
Affiliation(s)
- A L Oliveira
- Department of Polymer Engineering, University of Minho, School of Engineering, Campus de Gualtar, 4719, Braga, Portugal
| | | | | | | | | |
Collapse
|
39
|
Silva AM, Bambirra EA, Oliveira AL, Souza PP, Gomes DA, Vieira EC, Nicoli JR. Protective effect of bifidus milk on the experimental infection with Salmonella enteritidis subsp. typhimurium in conventional and gnotobiotic mice. J Appl Microbiol 1999; 86:331-6. [PMID: 10063632 DOI: 10.1046/j.1365-2672.1999.00674.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ability of Bifidobacterium bifidum from a commercial bifidus milk to antagonize Salmonella enteritidis subsp. typhimurium in vivo, and to reduce the pathological consequences for the host, was determined using conventional and gnotobiotic mice. Conventional animals received daily, by gavage, 0.1 ml bifidus milk containing about 10(9) cfu B. bifidum and germ-free animals received a single 0.1 ml dose. The conventional and gnotobiotic groups were challenged orally with 10(2) cfu of the pathogenic bacteria 5 and/or 10 d after the beginning of treatment. Control groups were treated with milk. Bifidus milk protected both animal models against the challenge with the pathogenic bacteria, as demonstrated by survival and histopathological data. However, to obtain the protective effect in gnotobiotic animals, the treatment had to be initiated 10 d before the challenge. In experimental and control gnotobiotic mice, Salm. enteritidis subsp. typhimurium became similarly established at levels ranging from 10(8) to 10(9) viable cells g-1 of faeces and remained at these high levels until the animals died or were sacrificed. It was concluded that the protection against Salm. enteritidis subsp. typhimurium observed in conventional and gnotobiotic mice treated with bifidus milk was not due to the reduction of the intestinal populations of the pathogenic bacteria.
Collapse
Affiliation(s)
- A M Silva
- Departamento de Microbiologia, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | | | | | | |
Collapse
|
40
|
Menezes AM, Barros FC, Victora CG, Tomasi E, Halpern R, Oliveira AL. [Risk factors for perinatal mortality in Pelotas, a southern city of Brazil, 1993]. Rev Saude Publica 1998; 32:209-16. [PMID: 9778854 DOI: 10.1590/s0034-89101998000300002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Although there was a considerable reduction in infant mortality in Pelotas, Rio Grande do Sul in the last decade, its perinatal causes were reduced only by 28%. The associated factors of these causes were analysed. MATERIAL AND METHOD All hospital births and perinatal deaths were assessed by daily visits to all the maternity hospitals in the city, throughout 1993 and including the first week of 1994. RESULTS The perinatal mortality rate was 22.1 per thousand births. The multivariate analysis showed the following risk factors: low socioeconomic level, male sex and maternal age above 35 years. Among multigravidae women, the fetal mortality rate was significantly increased for mothers with a previously low birthweight and a previous stillbirth. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight. CONCLUSIONS Main risk factors for perinatal mortality: low socioeconomic level, maternal age above 35 years and male sex. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight.
Collapse
Affiliation(s)
- A M Menezes
- Departamento de Clínica Médica, Faculdade de Medicina, Universidade Federal de Pelotas (FMUFPel), RS-Brasil.
| | | | | | | | | | | |
Collapse
|
41
|
Schubach A, Marzochi MC, Cuzzi-Maya T, Oliveira AV, Araujo ML, Oliveira AL, Pacheco RS, Momen H, Conceicao-Silva F, Coutinho SG, Marzochi KB. Cutaneous scars in American tegumentary leishmaniasis patients: a site of Leishmania (Viannia) braziliensis persistence and viability eleven years after antimonial therapy and clinical cure. Am J Trop Med Hyg 1998; 58:824-7. [PMID: 9660473 DOI: 10.4269/ajtmh.1998.58.824] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Two former patients treated for the cutaneous form of American tegumentary leishmaniasis were reviewed eight and 11 years, respectively, following clinical cure. We were able to isolate Leishmania parasites in a culture of material from the two scar biopsies, and in one of them the parasite was characterized as Leishmania (Viannia) braziliensis. In both cases, the histopathology revealed discreet hyperceratosis and a slight infiltrate of mononuclear cells surrounding and on the walls of the surface and deep dermal vessels. No amastigotes were seen on immunohistochemical or histopathologic examination. The Montenegro skin test result and the in vitro lymphoproliferative response to Leishmania antigen were positive, but no specific IgG and IgM antibodies were detected. Otorhinolaryngologic examination showed no macroscopic alteration in the mucosae. These findings are important for the evaluation and criteria of post-treatment cure.
Collapse
Affiliation(s)
- A Schubach
- Hospital Evandro Chagas, Instituto Oswaldo Cruz, Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Menezes AM, Victora CG, Barros FC, Menezes FS, Jannke H, Albernaz E, Halpern R, Grassi P, Oliveira AL. [Populational study of investigation of perinatal and infant deaths: methodology, validity of diagnosis and under-registration]. J Pediatr (Rio J) 1997; 73:383-7. [PMID: 14685371 DOI: 10.2223/jped.565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE The main objectives of the present study were to evaluate the percentage of under-registration of infant mortality in 1993 and compare it with the ones found 1982; to analyze the agreement between the official death certificates and the ones made by the referees. METHODS The infant mortality of all children born in Pelotas, in 1993, was monitored through daily visits to hospitals, as it was done in 1982; monthly, cemeteries and public registration offices were visited to detect any deaths outside the hospitals. Besides the official death certificates, two independent referees established the underlying cause of death based on information from pediatricians, case-notes, autopsies and through a home visit to the parents of the children. RESULTS The percentage of under-registration fell substantially from 24%, in 1982, to 5.4%, in 1993. The agreement between the official death certificates and the ones made by the referees showed satisfactory Kappas, unless for ill defined diseases such as sudden infant death, where the agreement was null. CONCLUSIONS The authors conclude that there was a significant fell of the under-registration for infant death in Pelotas, and the ill defined causes such as sudden infant death have been hidden by the diagnosis of pneumonia.
Collapse
Affiliation(s)
- A M Menezes
- Departamento de Clínica Médica, Universidade Federal de Pelotas, Pelotas, RS
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Oliveira AL, Risling M, Deckner M, Lindholm T, Langone F, Cullheim S. Neonatal sciatic nerve transection induces TUNEL labeling of neurons in the rat spinal cord and DRG. Neuroreport 1997; 8:2837-40. [PMID: 9376514 DOI: 10.1097/00001756-199709080-00006] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Transection of a peripheral nerve in neonatal rats induces an extensive death of axotomized neurons. We demonstrate here that spinal motoneurons and sensory dorsal root ganglia neurons become TUNEL-labeled after sciatic nerve transection in neonatal rats, thus indicating that apoptotic mechanisms are involved in the death process. Interestingly, there is also a profound increase of TUNEL-labeled interneurons in the deep dorsal horn. This location suggests that an intact afferent input and/or contact with target cells is essential for interneuronal survival. Death of motoneurons and sensory neurons could be a result of the injury per se and/or the deprivation of neurotrophic substances, secondary to the loss of contact with target cells.
Collapse
Affiliation(s)
- A L Oliveira
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
44
|
da Silva EF, Oliveira AL, Siefer MW, Gazetta ML, Bertani IF. [Demographic profile and work situation of patients with Chagas disease]. Arq Bras Cardiol 1995; 65:43-6. [PMID: 8546595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PURPOSE To evaluate the social profile and work habits in patients with Chagas' disease. METHODS We studied 284 ambulatory patients age ranged 21 to 74 years, female (62.3%) and married people (71.8%) divided according to their activities in three groups: active workers--121 (42.7%); under social security--93 (32.8%); housewives--61 (21.4%); unemployed people--9 (3.1%). RESULTS The majority of them were in stage II of Chagas' disease, 123 (43.3%) for both sexes. Migratory characteristics in this population was observed, with the search for work as the main reason for this. The level of education was low, considerably affecting the kind of profession. CONCLUSION Patients with Chagas' disease are originally from the rural area and migrate to urban area in order to improve economic conditions. They show unfavourable social conditions, with inadequate level of education and lack of professional gratifications.
Collapse
Affiliation(s)
- E F da Silva
- Instituto do Coração do Hospital das Clínicas, FMUSP
| | | | | | | | | |
Collapse
|
45
|
Oliveira AL, Teixeira AF. Erratum: Toroidal magnetic field in closed Robertson-Walker cosmologies. Phys Rev D Part Fields 1995; 51:3135. [PMID: 10021671 DOI: 10.1103/physrevd.51.3135.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
46
|
Oliveira AL, Teixeira AF. Toroidal magnetic field in closed Robertson-Walker cosmologies. Phys Rev D Part Fields 1994; 50:5429-5430. [PMID: 10018196 DOI: 10.1103/physrevd.50.5429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
47
|
Oliveira AL, Batista JL, Silva AP, Sobrinho LG, Rocha LC. Endemic goitre in Guinea-Bissau. Bull World Health Organ 1991; 69:347-8. [PMID: 1893511 PMCID: PMC2393096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A survey was performed of endemic goitre in the Oio, Gabu, and Cacheu regions of Guinea-Bissau. Among adult women, the following prevalences of goitre were observed: 53% (Oio), 48% (Gabu), and 27% (Cacheu). For goitres of grades 2 and 3 only, the prevalences were 20% (Oio), 13% (Gabu), and 2% (Cacheu). No cretinism or cases of thyroid dysfunction were found. The mean urinary iodine excretions in Oio, Gabu, and Cacheu were 17 micrograms/g, 24 micrograms/g and 33 micrograms/g creatinine, respectively.
Collapse
Affiliation(s)
- A L Oliveira
- Institute of Hygiene and Tropical Medicine, Lisbon, Portugal
| | | | | | | | | |
Collapse
|