Microfluidic-based skin-on-chip systems for safety assessment of nanomaterials.

The skin is the body's largest organ, continuously exposed to and affected by natural and anthropogenic nanomaterials (materials with external and internal dimensions in the nanoscale range). This broad spectrum of insults gives rise to irreversible health effects (from skin corrosion to cancer). Organ-on-chip systems can recapitulate skin physiology with high fidelity and potentially revolutionize the safety assessment of nanomaterials. Here, we review current advances in skin-on-chip models and their potential to elucidate biological mechanisms. Further, strategies are discussed to recapitulate skin physiology on-chip, improving control over nanomaterials exposure and transport across cells. Finally, we highlight future opportunities and challenges from design and fabrication to acceptance by regulatory bodies and industry.

Estudo preliminar toxicológico, antibacteriano e fitoquímico do extrato etanólico das folhas de Jatropha mollissima (Pohl) Baill. (pinhão-bravo, Euphorbiaceae), coletada no Município de Tauá, Ceará, Nordeste Brasileiro / Toxicological, antibacterial, and phytochemical preliminary study of the ethanolic extract of Jatropha mollissima (Pohl) Baill (pinhão-bravo, Euphorbiaceae) leaves, collected in Tauá, Ceará, Northeastern Brazil

RESUMO A cada dia, cepas bacterianas estão tornando-se resistentes a diversos antibióticos, o que faz necessária a busca de novas substâncias eficazes para o tratamento de doenças. Desta forma, este trabalho reporta o estudo preliminar toxicológico, antibacteriano e fitoquímico do extrato etanólico das folhas de Jatropha mollissima (pinhão-bravo, Euphorbiaceae), coletada no Município de Tauá, Ceará, Nordeste Brasileiro. Inicialmente, realizou-se o teste de toxicidade do extrato contra Artemia salina. Na sequencia, foi realizado o ensaio antibacteriano contra quatro cepas bacterianas Gram-negativas (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Hafnia alvei ATCC 51873, Klebsiella pneumoniae ATCC 13883) e uma cepa Gram-positiva (Enterococcus faecalis ATCC 29212). Finalmente, fez-se a análise fitoquímica preliminar do extrato ativo para detecção das principais classes de metabólitos especiais. Como resultado, o extrato etanólico das folhas de J. mollissima se mostrou tóxico para Artemia salina, pois apresentou CL50 igual a 406,02 μg/mL. Quanto à ação antibacteriana, o extrato se mostrou ativo contra a bactéria Gram-positiva Enterococcus faecalis ATCC 29212, apresentando moderada atividade antibacteriana (halo de inibição igual a 7,03 mm). Evidenciou-se no extrato bioativo a presença de cumarinas, fenóis, taninos, flavonoides (flavonóis e flavanonas), alcaloides e esteroides, ambas as classes reportadas como antimicrobianos. Portanto, esse extrato tem potencial para ser usado na produção de fármacos contra infecções causadas por bactérias Gram-positivas. No entanto, as informações direcionam estudos futuros para o isolamento e identificação dos compostos bioativos, monitorados sob a ação antibacteriana mais expressiva.

ABSTRACT Each day, bacterial strains are becoming more resistant to various antibiotics, which requires the search for new effective substances for the treatment of diseases. Thus, this study reports the toxicological, antibacterial, and phytochemical preliminary study of the ethanolic extracts of Jatropha mollissima (pinhão-bravo, Euphorbiaceae) leaves, collected in Tauá, Ceará, Northeast of Brazil. Initially, we performed the toxicity testing of the extract against Artemia salina. Then, we conducted the antibacterial assay against four Gram-negative bacterial strains (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Hafnia alvei ATCC 51873, Klebsiella pneumoniae ATCC 13883), and one Gram-positive strain (Enterococcus faecalis ATCC 29212). Finally, we carried out the preliminary phytochemical analysis of the active extract to detect the main classes of special metabolites. As a result, the ethanolic extract of J. mollissima leaves was toxic to Artemia salina, because it presented LC50 equal to 406.02 µg/mL. Regarding antibacterial action, the extract was active against the Gram-positive bacteria Enterococcus faecalis ATCC 29212, with moderate antibacterial activity (inhibition zone equal to 7.03 mm). The bioactive extract had the presence of coumarins, phenols, tannins, flavonoids (flavanols and flavonones), alkaloids and steroids, both classes reported as antimicrobials. Therefore, this extract has the potential to be used in the production of drugs against infections caused by Gram-positive bacteria. However, these information require further studies for the isolation and identification of bioactive compounds, monitored under the more expressive antibacterial action.

First cytogenetic study of Cavernicola pilosa Barber, 1937 (Hemiptera, Triatominae).

Cavernicola pilosa is a triatomine species that lives in caves and feeds on bat blood. This vector has a wide geographical distribution, and is found in Brazil, Colombia, Panama, Peru, and Venezuela. Little is known about the reproductive biology of this species, because most previous studies have only characterized its morphology, morphometry, ecology, and epidemiology. Therefore, this study aimed to obtain preliminary data related to spermatogenesis in C. pilosa by conducting cytogenetic analysis. Analysis of the heterochromatic pattern of C. pilosa during the initial prophases revealed that heterochromatic blocks are only present in the sex chromosomes. Based on the analyses of the meiotic metaphase and prophases, we found that the sex determination system of C. pilosa is XY and the chromosomes are holocentric. C. pilosa spermatids are filamentous and have long flagella. It was not possible to detect corpuscle or filament heteropycnosis in spermatids of this species. The initial cytogenetic data presented in this study are important in characterizing the spermatogenesis and heterochromatic patterns of C. pilosa. Our results suggest that adaptation to troglodytism did not result in differences in spermatogenesis in this vector.

Anterior tuberculous scleritis: A diagnostic challenge.

CASE REPORT: We present the case of a 26 year-old Pakistani male, who after the presumptive diagnosis of anterior tuberculous scleritis (by an atypical clinical appearance and positive epidemiological link), was diagnosed with pulmonary tuberculosis. DISCUSSION: Nodular anterior scleritis is an uncommon presentation of tuberculosis (TB). It is considered a diagnostic challenge because of the difficulty to extract bacilli from the ocular tissue. However, a detailed medical history and eye examination can be the key to an accurate diagnosis and appropriate treatment of the TB.

Diurnal behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate / Comportamento diurno de vacas leiteiras em pastagem de alfafa suplementada com silagem de milho e concentrado

The diurnal ingestive behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate was evaluated. Sixteen Holstein dairy cows in mid-lactation were used in a randomized block design. The treatments were partial replacement of corn silage for limited alfalfa grazing time (LGT) or unlimited grazing time (UGT). Rotational alfalfa grazing was used and the amount of concentrate fed was the same in both treatments. Behavioral activities observed were time spent grazing, rumination and idleness, during four days, from 8:00 AM to 7:00 PM. From 2:00 to 5:00 PM grazing was intermittent and short-lasting on UGT, whereas on LGT grazing activity was longer than UGT in the morning and at the end of the afternoon. Restriction in available grazing time clearly influenced the distribution of time spent with grazing, rumination and idleness throughout the day. However, this effect was not observed in the total time spent in these activities...

Avaliou-se o comportamento ingestivo de vacas leiteiras com acesso restrito ou irrestrito a uma pastagem de alfafa suplementada com silagem de milho e concentrado. Utilizaram-se 16 vacas da raça Holandesa, em estádio médio de lactação, em delineamento em blocos ao acaso. Os tratamentos foram: silagem de milho substituída parcialmente por pastejo restrito ou irrestrito de alfafa. As vacas foram manejadas em sistema de pastejo rotacionado e a quantidade de concentrado foi igual em ambos os tratamentos. As atividades comportamentais observadas foram pastejo, ruminação e ócio, das oito às 19 horas, em quatro ocasiões. No pastejo irrestrito, observou-se que, nos horários entre 14 e 17 horas, o pastejo foi intermitente e de curta duração, enquanto no pastejo restrito a atividade de pastejo foi mais prolongada durante a manhã e no final da tarde. A restrição no tempo disponível para pastejo da alfafa influenciou marcadamente a distribuição, no decorrer do dia, do tempo gasto em pastejo, da ruminação e do ócio. Entretanto, não se observou este efeito no tempo total gasto nestas atividades...

Ocorrência de Salmonella spp. e Staphylococcus coagulase positiva em pescado no nordeste, Brasil / Occurrence of Salmonella spp. and coagulse positive Staphylococcus in fish and crustaceans in the northeast of Brazil

O presente estudo foi conduzido com o objetivo de verificar a ocorrência de Salmonella spp. e Staphylococcus coagulase positiva em pescados e crustáceos provenientes da região nordeste no período de fevereiro de 2004 a dezembro de 2005. Das 143 amostras de peixes e crustáceos (camarão congelado e cauda de lagosta), 5 (3,5%) apresentaram-se positivas para Salmonella spp. Enquanto nas amostras de peixe e cauda de lagosta a contagem de Staphylococcus coagulase positiva foi < 1,0 x 102UFC/g estimado, nas amostras de camarão congelado, em duas a contagem foi 1,0 x 101UFC/g estimado e em uma 2,6 x 101UFC/g estimado, as demais <1,0 x 101UFC/g estimado. Com base nos resultados obtidos conclui-se que as amostras analisadas apresentaram baixos níveis de ocorrência de Salmonella spp. e Staphylococcus coagulase positiva e que, mesmo com estes baixos índices, constantemente deve-se buscar uma melhora na qualidade dos produtos da pesca, melhora esta que passa pelo treinamento constante em boas práticas de fabricação, procedimentos padrões de higienização e análise de perigos e pontos críticos de controle do pessoal que trabalha na pesca ou em fazendas de criação de camarão, bem como dos funcionários das indústrias.

The present study was carried out to evaluate the occurrence of Salmonella spp. and coagulase-positive Staphylococcus in fish and crustaceans from the Brazilian Northeast. Five out of the 143 samples (3.5%) were positive for Salmonella spp. While none of the fish and lobster tail samples were positive for coagulase positive Staphylococcus, two shrimp samples presented an estimated count of 1.0 x 101colony forming units per gram (cfu/g), and one presented 2.6 x 101 cfu/g. The results showed a low level of Salmonella and coagulase positive Staphylococcus occurrence. However, even with these low levels of bacterial numbers in fish and crustaceans we should search look for an improvement in their quality. This improvement should be associated to constant training for good manufacturing practice, a standard procedure of hygiene and analysis of hazards and critical control points related to employees that work as fishers or on shrimp farms, as well as those working in the industry as a whole.

[Traditional risk factors for cardiovascular disease in primary antiphospholipid syndrome (APS) when compared with secondary APS: a study with 96 patients]. / Fatores de risco tradicionais para doença cardiovascular na síndrome antifosfolípide 36 primária comparada à secundária: um estudo de 96 pacientes.

OBJECTIVE: To evaluate the prevalence of traditional risk factors in patients with primary antiphospholipid syndrome (APS) in comparison to those with systemic lupus erythematosus-secondary APS. METHODS: Transversal study of 96 APS patients (Sapporo's criteria). Demographic and clinical data, cardiovascular risk factors and drug use were investigated. RESULTS: Thirty-nine Primary APS and 57 secondary APS were included. The groups did not differ regarding age (38.5 +/- 9.9 vs. 39.4 +/- 10.5 years, p=0.84) and female gender (84.6 vs. 96.5%, p=0.06), respectively. Arterial events were more observed in primary than secondary APS (59 vs. 36.8%, p=0.04) patients. No difference was seen concerning venous and obstetric events. In regard to traditional risk factors for cardiovascular disease, both groups were comparable related to current or previous smoking, sedentarism, family history for coronary disease, systemic hypertension, diabetes mellitus, overweight and obesity. The frequencies of altered lipid profiles were alike in the two groups, except for a higher prevalence of low HDL-c levels in primary APS group (84.6 vs. 45.5%, p=0.0001). Concerning drug use, no significant differences were observed related to chloroquine and statin use, however the secondary APS patients had a higher rate of prednisone use (10.2 vs. 57.9%, p<0.001) as well as mean dose of corticosteroid (1.5 +/- 5.7 vs. 9.2 +/- 12.5mg/ /day, p=0.0001). CONCLUSION: Traditional risk factors for cardiovascular disease are present and comparable between patients with primary and secondary APS, except for a high frequency of low HDL-c in primary APS patients.

Resistência antimicrobiana em Salmonella Enteritidis isoladas de amostras clínicas e ambientais de frangos de corte e matrizes pesadas / Antimicrobial resistance in Salmonella Enteritidis isolated from clinical and environmental broiler chickens and breeders broiler

The antimicrobial resistance of Salmonella Enteritidis strains isolated from clinical and environmental poultry samples in the Southern Brazil during the years of 1999, 2000 and 2001 was evaluated. Among the 79 isolated samples, 64 (81 percent) were resistant to at least one of the antimicrobial agents tested, showing 22 different resistance patterns. Tetracycline showed the highest percentage (64,5 percent) of resistance among the antimicrobial agents used. Resistance to drugs at different levels was found as the following: ampicillin (1.2 percent), kanamycin (1.2 percent), ciprofloxacin (2.5 percent), enrofloxacin (8.8 percent), gentamicin (21.5 percent), streptomycin (20.2 percent), nitrofurantoin (26.6 percent), and nalidixic acid (30.4 percent). None of the S. Enteritidis strains were resistant to chloramphenicol, norfloxacin, and polimycin B. Among the 64 S. Enteritidis strains that showed resistance, 43 (67.2 percent) were resistant to two or more antimicrobial agents. Twenty-one (32.8 percent) strains were resistant to only one of the antimicrobial agents, 14 to tetracycline, three to nalidixic acid, three to nitrofurantoin, and one to gentamycin. These antimicrobial resistance levels suggest a high occurrence of tetracycline resistant S. Enteritidis strains and resistance to two or more antimicrobial agents.

Non-invasive diagnosis of acute rejection in kidney transplants with delayed graft function.

Delayed graft function (DGF) often occurs in kidney transplants from deceased donors. We wanted to provide studies giving more accurate non-invasive tests for acute rejection (AR). Using real-time PCR, we examined the expression of cytolytic molecules such as perforin, granzyme B, and fas-ligand along with serpin proteinase inhibitor-9. We also measured the expression of FOXP3, a characteristic gene of T-regulatory cells known to be involved in AR. These studies were conducted on peripheral blood monocytes, urinary cells, and 48 surveillance kidney biopsies taken from a total of 35 patients with DGF. Of these patients, 20 had a histopathological diagnosis of AR, whereas other 28 had characteristics of acute tubular necrosis (ATN). Expression of cytolytic and apoptotic-associated genes in the biopsy tissue, peripheral blood leukocytes, and urinary cells was significantly higher in patients with AR than that in patients with ATN. Diagnostic parameters associated with FOXP3 gene expression were most accurate in peripheral blood leukocytes and urine cells with sensitivity, specificity, positive and negative predictive values, and accuracy between 94 and 100%. Our study shows that quantification of selected genes in peripheral blood leukocytes and urinary cells from renal transplant patients with DGF may provide a useful and accurate non-invasive diagnosis of AR.

Utility of biopsy in kidney transplants with delayed graft function and acute dysfunction.

Renal biopsy is currently the gold standard to assess the causes of renal allograft dysfunction. In the present study, we prospectively assessed the role of the renal allograft biopsy in the diagnosis and treatment of renal allograft dysfunction. Seven hundred and fifteen biopsies were performed in 399 patients. The anatomopathological results in group 1 (delayed graft function) were: 60.4% acute tubular necrosis, 17.6% acute rejection, 4.3% calcineurin inhibitor toxicity, and 17.7% other diagnoses; in group 2 (acute graft dysfunction): 42.3% acute rejection, 22% acute tubular necrosis, 8.4% calcineurin inhibitor toxicity, and 27.3% other diagnoses. Among patients with delayed graft function, 42.2% of biopsies led to a change in the treatment. In 60.5%, the biopsy of patients with acute dysfunction led to a change in the patient management. In our series, the result of the biopsy disagreed with the clinical diagnosis in 39.6% and 57.7% of cases, respectively. These results demonstrated that renal graft biopsy remains an indispensable tool for the accurate management of kidney transplant patients.

Aspectos da bovinocultura leiteira no Município de Ilhéus-BA / Characterization of dairy cattle production in Ilhéus -BA

The results show that the milk production activity in the county of Ilhéus, Bahia state, Brazil, lacks of technologies that could improve milk productivity. General information about the farms were obtained through a survey. Thirty-seven (43.5 percent) farms were smaller or equal to 50ha and 65 (76.5 percent) farms produced 50l of milk per day, characterizing these farmers as small producers. In 46 (54.1 percent) farms no information concerning costs, level of production, reproduction efficiency or sanity of the herds were found. In 29 (34.2 percent) farms the information was registered in portable computer database, six (7.1 percent) farms used structured index cards and four (4.7 percent) farms had desktop computers. Forty-one (48.2 percent) farms had roofed and paved milk facilities, three (3.5 percent) farms had not roofed but paved, in 31 (36.5 percent) farms the corrals were not roofed and unpaved, and 10 (11.8 percent) farms had no constructions.

Prevalência de tuberculose e brucelose bovina no município de Ilhéus / Prevalence of bovine tuberculosis and brucellosis in Ilhéus, Bahia - Brazil

Aiming to determining the prevalence of tuberculosis and brucellosis in Ilhéus, Bahia, Brazil, 916 cows aged 24 months or above and allocated in 85 farms were tested. The compared cervical intradermic tuberculosis and serological buffered acidified antigen (BAA), slow tube serum agglutination (STSA) and 2-mercapto ethanol (2-ME) tests were used. The prevalence of tuberculosis and brucellosis was 2.8 and 1.9 percent, respectively. The distribution of positive farms (10.6 percent) is in agreement with the notion that these diseases are widespread in the country

Immobilization of luciferase from a firefly lantern extract on glass strips as an alternative strategy for luminescent detection of ATP.

The bioluminescent reaction catalysed by firefly luciferase has become widely established as an outstanding analytical system for assay of ATP. When used in solution, luciferase is unstable and cannot be re-used, a problem that can be partially circumvented by immobilizing the enzyme on solid substrates. Transparent glass is especially advantageous over alternative immobilizing matrices, since it allows most of the emitted photons to be detected. We report a new method for luciferase immobilization on glass which does not require prior silanization and glutaraldehyde activation, thus saving preparation time and minimizing enzyme inactivation. Our method is based on the co-immobilization by adsorption of luciferase (from a firefly lantern extract) and poly-L-lysine (PL) on non-porous glass strips. Luciferase immobilized in this way exhibits minimal variations in intersample activity, high sensitivity for ATP detection (linear luminescence responses down to 50 nmol/L) and good stability (full activity for at least 60 days when stored at -80 degrees C). PL-mediated immobilization of luciferase on glass strips provides an attractive strategy for the design of specific ATP biosensors, with potential in industry, environmental screening, medicine and biological research.

Métodos para diagnóstico microbiológico de mastite clínica bovina / Microbiological methods for diagnosis of clinical bovine mastitis

O objetivo deste trabalho foi comparar três procedimentos de semeadura do leite para diagnóstico microbiológico da mastite bovina: "in natura", pós-congelamento de 12 horas a -20ºC e pós-incubaçäo a 37§C por 12 horas. Foram examinados 256 amostras de leite procedentes de 200 vacas com mastite clínica de cinco propriedades leiteiras. Os resultados bacteriológicos após os tratamentos descritos mostraram aumento dos microrganismos isolados. Observou-se aumento significativo do Staphylococcus sp nas amostras congeladas e incubadas, aumento da Klebsiella sp e do Pseudomonas sp apenas no pós-incubaçäo, e reduçäo do Corynebacterium bovis, nos isolamentos pós-incubaçäo. Näo se obervou diferença entre os tratamentos "in natura" e pós-congelamento. Pode-se concluir que a melhor conduta para diagnóstico da mastite seria a associaçäo destes procedimentos para se obter maior taxa de isolamento, permitindo estabelecer o diagnóstico e instituir a conduta terapêutica adequada

Erros profissionais e seus aspectos jurídicos em odontologia legal / Professional malpractice and its juridical aspects in legal dentistry

Revisäo de literatura sobre os aspectos éticos e jurídicos do tema "Erros Profissionais, à luz da Odontologia Legal"