Áurea Silveira Cruz

Teste in vitro de citotoxicidade: estudo comparativo entre duas metodologias

A avaliacao in vitro da biocompatibilidade de diferentes tipos de biomateriais foi realizada pelo teste de citotoxicidade em cultivo de celulas de tecido conectivo de camundongos, NCTC Clone 929 da American Type Culture Collection. O estudo comparativo do ensaio de citotoxicidade foi realizado com duas metodologias: 1) ensaio de difusao em agar e 2) ensaio de incorporacao do vermelho neutro. Os resultados obtidos demonstraram que ambas as metodologias podem ser utilizadas, de acordo com o tipo de amostra a ser analisada.

Human vaccinia-like virus outbreaks in São Paulo and Goiás States, Brazil: virus detection, isolation and identification

Since October 2001, the Adolfo Lutz Institute has been receiving vesicular fluids and scab specimens of patients from Paraíba Valley region in the São Paulo and Minas Gerais States and from São Patricio Valley, in the Goiás State. Epidemiological data suggested that the outbreaks were caused by Cowpox virus or Vaccinia virus. Most of the patients are dairy milkers that had vesiculo-pustular lesions on the hands, arms, forearms, and some of them, on the face. Virus particles with orthopoxvirus morphology were detected by direct electron microscopy (DEM) in samples of 49 (66.21%) patients of a total of 74 analyzed. Viruses were isolated in Vero cell culture and on chorioallantoic membrane (CAM) of embryonated chicken eggs. Among 21 samples submitted to PCR using primers for hemagglutinin (HA) gene, 19 were positive. Restriction digestion with TaqI resulted in four characteristic Vaccinia virus fragments. HA nucleotide sequences showed 99.9% similarity with Cantagalo virus, described as a strain of Vaccinia virus. The only difference observed was the substitution of one nucleotide in the position 616 leading to change in one amino acid of the protein in the position 206. The phylogenetic analysis showed that the isolates clustered together with Cantagalo virus, other Vaccinia strains and Rabbitpox virus.

Cellulose acetate propionate coated titanium: characterization and biotechnological application

Surfaces of pure titanium and Ti coated with cellulose acetate propionate (CAP) have been characterized by means of scanning electron microscopy X ray coupled with elemental microanalysis (SEM-EDS), ellipsometry, atomic force microscopy (AFM) and contact angle measurements. Coating Ti surfaces with CAP ultrathin films reduced original surface roughness. Surface energy and wettability of CAP covered Ti surfaces pure Ti surfaces were similar. The adsorption of lysozyme (LYZ), an antibacterial protein, onto Ti and CAP-coated Ti surfaces has been studied by means of ellipsometry and atomic force microscopy (AFM). The adsorption of LYZ was mainly driven by hydrophobic interaction between protein hydrophobic residues and CAP propyl groups. Pure Ti and CAP coated Ti surfaces presented no cytotoxicity effect and proved to be adequate substrates for cell adhesion. The biocompatibility of CAP coated Ti surfaces was attributed to the surface enrichment in glucopyranosyl residues and short alkyl side groups.

Investigation of influenza in migrating birds, the primordial reservoir and transmitters of influenza in Brazil

Birds are the most important reservoirs of the influenza virus. Its maintenance in its natural hosts, including man, allows the influenza virus to reassorts its strains. The recent report of an avian influenza A (H5N1) virus in humans, was in a child with fatal respiratory illness in China, 1997. The current study was conducted to elucidate the transportation of the influenza by birds that migrate, annually, through the both Northern and Southern hemispheres, with special attention paid to the Vireo olivaceus [Juruviara(BR) or Red-eyed vireo(USA)] species, which travels from the USA to Brazil, and vice versa, and the Elaenia mesoleuca [Tuque(BR) or (USA)] species that flies over the entire Southern Hemisphere. There are two species of birds, which breed and migrate in Sao Paulo State, Brazil, and which were demonstrated to carry Influenza virus, were selected. The viral particles isolated were observed by electron microscopy. The influenza virus was detected by the House Duplex/PCR and Gloria molecular biology tests. The results demonstrated that the Elaenia mesoleuca and Vireo olivaceus bird species are carrying the Influenza virus whilst crossing both the Northern and Southern hemispheres. To understand the role that these migrating birds may play in epidemic influenza, in Brazil, characterization of avian influenza subtypes will be done.

RC-IAL cell line: sensitivity of rubella virus grow

OBJECTIVE The rapid growth of the rubella virus in RC-IAL2 with development of cytopathic effect, in response to rubella virus infection, is described. For purposes of comparison, the rubella virus RA-27/3 strain was titered simultaneously in the RC-IAL, Vero, SIRC and RK13 cell lines. METHODS Rubella virus RA-27/3 strain are inoculated in the RC-IAL cell line (rabbit Kidney, Institute Adolfo Lutz). Plates containing 1.5x10(5) cells/ml of RC-IAL line were inoculated with 0.1ml s RA-27/3 strain virus containing 1x 10(4)TCID50/0.1ml. A 25% cytopathic effect was observed after 48 hours and 100% after 96 hours. The results obtained were compared to those observed with the SIRC, Vero and RK13 cell lines. Rubella virus was detected by immunohistochemistry. RESULTS With the results, it was possible to conclude that the RC-IAL cell line is a very good substrate for culturing rubella virus. The cells inoculated with rubella virus were examined by phase contrast microscopy and showed the characteristic rounded, bipolar and multipolar cells. The CPE in RC-IAL was observed in the first 48 hours and the curve of the increased infectivity was practically the same as observed in other cell lines. CONCLUSIONS These findings are important since this is one the few cell lines described in the literature with a cytopathic effect. So it can be used for antigen preparation and serological testing for the diagnosis of specific rubella antibodies.

Occurrence of influenza B/Hong Kong-Like strains in Brazil, during 2002

Through the influenza virus surveillance from January to October 2002, influenza B/Hong Kong-like strains circulating in the Southeast and Centre East regions of Brazil have been demonstrated. This strain is a variant from B/Victoria/02/88 whose since 1991 and until recently have been isolated relatively infrequently and have been limited to South-Eastern Asia. A total of 510 respiratory secretions were collected from patients 0 to 60 years of age, with acute respiratory illness, living in the Southeast and Centre East regions of Brazil, of which 86 (17.13%) were positive for influenza virus. Among them 12 (13.95%) were characterized as B/Hong Kong/330/2001; 3 (3.49%) as B/Hong Kong/1351/2002 a variant from B/Hong Kong/330/2001; 1 (1.16%) as B/Sichuan/379/99; 1 (1.16%) as B/Shizuoka/5/2001, until now. The percentages of cases notified during the surveillance period were 34.88%, 15.12%, 15.12%, 4.65%, 15.12%, 13.95%, in the age groups of 0-4, 5-10, 11-15, 16-20, 21-30, 31-50, respectively. The highest proportion of isolates was observed among children younger than 4 years but serious morbidity and mortality has not been observed among people older than 65 years, although B influenza virus component for vaccination campaign 2002 was B/Sichuan/379/99 strain. This was probably due to the elderly protection acquired against B/Victoria/02/88. In addition, in influenza A/Panama/2007/99-like (H3N2) strains 22 (25.58%) were also detected, but influenza A(H1N1) has not been detected yet.

Determinação da segurança biológica do xampu de cetoconazol: teste de irritação ocular e avaliação do potencial de citotoxicidade in vitro

Ketoconazole is an antifungal agent and can be incorporated into several dosage forms, as an example it could be mentioned shampoos and creams. The aim of this work was to assess the biological reactivity in vivo (Draize eye test) and in vitro (cytotoxity test) of ketoconazole in shampoo degradeted under action of light. The formulation was exposed to UV-C (254 nm) radiation and two methods were used for the quantitative determination of ketoconazole: HPLC and microbiological assay. The results showed alteration in ketoconazole in presence of light - secondary peaks in chromatogram and decrease in antifungal activity - however, no alteration on the biological reactivity between ketoconazole shampoo and ketoconazole shampoo containing degradation products was observed.

RC-IAL: linhagem celular contínua de rim de coelho - características e substrato para replicação de vírus

A rabbit kidney cell line RC-IAL, isolated in 1976 and at present at 150a passage, has had its characteristics analysed. The cells presented morphology similar to fibroblasts throughout their culture. The cellular growth proportion remained unaltered from its isolation, with a cloning efficiency of around 9%. The line showed growth dependent on anchorage and chromosomic analysis presented the modal number of the species with small variations to about one chromosome, to a total of about 50%. The lines species of origin was confirmed through indirect immunofluorescence reaction and susceptibility to some viruses with cytopathic effect was verified with vaccinia, cowpox, herpes simplex types 1 and 2 and rubella viruses. This cellular substract is free from contaminating agents, thus satisfying the conditions for its use in scientific work, especially that relating to public health.Uma linhagem celular de rim de coelho (denominada RC-IAL), que foi isolada em 1976, e que atualmente esta na 150a passagem, teve suas caracteristicas analisadas. As celulas apresentaram morfologia semelhante aos fibroblastos desde o inicio de seu cultivo. A proporcao de crescimento celular nao se alterou desde seu isolamento, com uma eficiencia de clonagem ao redor de 9%. A linhagem mostrou crescimento dependente de ancoragem, e a analise cromossomica apresentou o numero modal da especie com pequenas variacoes para mais ou menos um cromossomo, resultando uma somatoria de 50%. Sua especie de origem foi comprovada atraves da reacao de imunofluorescencia indireta e a susceptibilidade da linhagem a alguns virus, com demonstracao do efeito citopatico, foi verificada com os virus da vacinia, cowpox, herpes simples tipo 1 e 2 e da rubeola. Esse substrato celular esta livre de contaminantes, satisfazendo assim, as condicoes para seu uso em trabalhos cientificos, principalmente os relacionadas a saude publica.

Avaliação da biocompatibilidade de implantes mamários de silicone esterilizados por calor seco e pelo óxido de etileno

Silicone breast implants have been widely used for mammary augmentation and reconstruction surgery. Biological safety of these implants can be altered by sterilization methods. This study consisted of the biocompatibility assessment of smooth and textured silicone gel breast implants sterilized by dry-heat and ethylene oxide through cell viability, employing neutral red uptake method. The NCTC clone 929 cell were employed and the results showed no cytotoxicity of implants after both sterilization processes.

In vitro tests of resveratrol radiomodifying effect on rhabdomyosarcoma cells by comet assay

Cancer is a global public health problem. Resveratrol is a defensive polyphenol that is synthesized by a wide variety of plants in response to exposure to ultraviolet radiation or also due to mechanical stress caused by the action of pathogens and chemical and physical agents. Grape vines have a high capacity to produce resveratrol, so grape juice and wine, mainly red wine, are considered good sources of resveratrol. The protective effects of resveratrol include promotion of antiinflammatory response, antitumor activity and prevention of degenerative diseases, reduced incidence of cardiovascular diseases and inhibition of platelet aggregation, among others. Therefore, resveratrol is considered to be a cell protector. However, at high concentrations, resveratrol promotes contrary effects by sensitizing cells. The aim of this study was to investigate in vitro the radiomodifying effect of resveratrol in culture of human rhabdomyosarcoma cells (RD) by applying the comet assay to evaluate the cell damage and repair capacity. The LD50 (lethal dose) obtained was 499.95 ± 9.83 Gy (Mean ± SD) and the CI50 (cytotoxicity index) was 150 μM in the RD cells. Based on these data, it was defined the gamma radiation doses (50 and 100 Gy) and resveratrol concentrations (15, 30 and 60 μM) to be used in this study. The results indicated that resveratrol acts as a cell protector at a concentration of 15 μM and has a cytotoxic effect at 60 μM. However, with the interaction of the gamma radiation, the concentration of 60 μM did not produce a statistically significant radiosensitizing effect.