Atividade antimicrobiana do óleo essencial de Lippia origanoides e Lippia rotundifolia frente a enterobactérias isoladas de aves / Antimicrobial activity of Lippia origanoides and Lippia rotundifolia oils against enterobacteria isolated from poultry

The aim of this study was to evaluate the antimicrobial activity of essential oils on enterobacteria Escherichia coli and Staphylococcus aureus isolated from poultry fecal samples in the cloaca from 49 laying hens. To analyze the antimicrobial sensibility an agar diffusion susceptibility test was performed and the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericida Concentration (MBC) of Lippia origanoides and Lippia rotundifolia essential oils was determined. The concentrations used were 160, 80 and 40 L/mL. The L. origanoides essential oil showed antimicrobial effect from 40 L/mL dose against both microorganisms, with larger efficiency in E. coli. The L.rotundifolia essential oil was more efficient at the concentration of 160L/mL. Its effect was observed in all microorganisms. These results suggest that L. origanoides oil is more effective than L. rotundifolia oil in inhibiting the growth of microorganism isolated from poultry, although it also has a satisfactory antimicrobial effect. Results indicate the potential use of these plant's essential oils in poultry feed as an alternative to conventional antimicrobial products.

Avaliação da atividade antibacteriana do óleo essencial de Lippia origanoides frente à Staphylococcus sp. isolados de alimentos de origem animal / Assessment of the antibacterial activity of the essential oil of Lippia origanoides in relation to Staphylococcus sp. isolated from food of animal origin

Objetivou-se no trabalho avaliar a ação antibacteriana do óleo essencial de Lippia origanoides frente à isolados de Staphylococcus sp. de alimentos de origem animal. Para tanto, realizou-se análise química da composição do óleo, teste de sensibilidade das bactérias frente a dez antibióticos de uso terapêutico e ao óleo essencial de Lippia origanoides, além da determinação da concentração inibitória mínima (CIM) e da concentração bactericida mínima (CBM). A análise cromatográfica do óleo apresentou o timol como composto majoritário (48,70%), além de pequena quantidade de carvacrol (1,14%). No teste de sensibilidade frente aos antibióticos, 75% dos isolados apresentaram resistência a, no mínimo, três antibióticos. Em relação ao óleo essencial, os isolados de Staphylococcus sp oriundos de leite bovino mostraram-se mais resistentes e os isolados de carne ovina apresentaram-se mais sensíveis. A CIM foi maior para os Staphylococcus sp. isolados de leite bovino e leite ovino (60µL/mL). Enquanto que para os isolados de carcaça de ovinos e queijo, a CIM foi de 15µL/mL e 30µL/mL respectivamente. A CBM, consequentemente, foi maior para os isolados de leite bovino e leite ovino, sendo de 240µL/mL e 120µL/mL respectivamente. O óleo essencial de Lippia origanoides apresenta atividade antimicrobiana sobre Staphylococcus sp. isolados de alimentos.

The aim of this study was to evaluate the antibacterial activity of the essential oil of Lippia origanoides in relation to Staphylococcus sp. isolated from food of animal origin. For this purpose, we performed the chemical analysis to determine the oil composition, evaluated the bacteria sensibility to ten antibiotics of therapeutic use and determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The chromatographic analysis showed that tymol was the main compound (48.70%) and that carvacrol was present in a small amount (1.14%). In the test of antibiotic susceptibility, 75% of the microorganism isolates were resistant to at least three of the ten antibiotics tested. The Staphylococcus sp isolated from bovine milk was more resistant to the essential oil of Lippia origanoides, and the microorganism isolated from sheep meat was more susceptible to this oil. The Staphylococcus sp. isolated from bovine or sheep milk showed a MIC of 60µL/mL and for those isolated from sheep carcass and cheese the MIC was 15µL/mL and 30µL/mL, respectively. Consequently, the MBC was higher for isolates from cow's (240µL/mL) and sheep's milk (120µL/mL) when compared with other food sources. These results suggest that the essential oil of Lippia origanoides has antimicrobial activity against staphylococcus sp. isolated from food.

Highly efficient siRNA delivery system into human and murine cells using single-wall carbon nanotubes.

Development of RNA interference (RNAi) technology utilizing short interfering RNA sequences (siRNA) has focused on creating methods for delivering siRNAs to cells and for enhancing siRNA stability in vitro and in vivo. Here, we describe a novel approach for siRNA cellular delivery using siRNA coiling into carboxyl-functionalized single-wall carbon nanotubes (SWCNTs). The CNT-siRNA delivery system successfully demonstrates nonspecific toxicity and transfection efficiency greater than 95%. This approach offers the potential for siRNA delivery into different types of cells, including hard-to-transfect cells, such as neuronal cells and cardiomyocytes. We also tested the CNT-siRNA system in a non-metastatic human hepatocellular carcinoma cell line (SKHep1). In all types of cells used in this work the CNT-siRNA delivery system showed high efficiency and apparent no side effects for various in vitro applications.

Searching for bioindicators of forest fragmentation: passerine birds in the Atlantic forest of southeastern Brazil.

Aiming to evaluate the potential of Passerine birds as bioindicators of forest fragmentation, we studied the avifauna in the mountain region of the state of Rio de Janeiro by mist-netting between 2001 and 2005. We sampled six sites, including four small fragments (from 4 to 64 ha) in an agricultural area (Teresópolis), one second-growth forest (440 ha - Miguel Pereira) and a continuous forest (10,600 ha, Serra dos Orgãos National Park - SONP). Indicator Species analysis and a Monte Carlo test were run to detect associations between species and sites, considering at least 30% of perfect indication and a significant value for the statistical test, only considering species with at least 10 captures. A total of 30 Passerine birds were sampled, and due to their association to the largest area (SONP), we considered Sclerurus scansor, Mionectes rufiventris, Chiroxiphia caudata and Habia rubica as the best indicators for this area. Five species were more captured not by chance in the 440 ha second-growth: Conopophaga melanops, Myiobius barbatus, Myrmeciza loricata, Philydor atricapillus and Schiffornis virescens and no species were related to any small fragment. This analysis has identified specialized Passerine species in many aspects (foraging substract, needs for nesting, rarity status), and it can be a valuable tool for detecting possible bioindicators.

Searching for bioindicators of forest fragmentation: passerine birds in the Atlantic forest of southeastern Brazil / Busca por bioindicadores de fragmentação florestal: aves Passeriformes na Floresta Atlântica do Sudeste do Brasil

Aiming to evaluate the potential of Passerine birds as bioindicators of forest fragmentation, we studied the avifauna in the mountain region of the state of Rio de Janeiro by mist-netting between 2001 and 2005. We sampled six sites, including four small fragments (from 4 to 64 ha) in an agricultural area (Teresópolis), one second-growth forest (440 ha - Miguel Pereira) and a continuous forest (10,600 ha, Serra dos Órgãos National Park - SONP). Indicator Species analysis and a Monte Carlo test were run to detect associations between species and sites, considering at least 30 percent of perfect indication and a significant value for the statistical test, only considering species with at least 10 captures. A total of 30 Passerine birds were sampled, and due to their association to the largest area (SONP), we considered Sclerurus scansor, Mionectes rufiventris, Chiroxiphia caudata and Habia rubica as the best indicators for this area. Five species were more captured not by chance in the 440 ha second-growth: Conopophaga melanops, Myiobius barbatus, Myrmeciza loricata, Philydor atricapillus and Schiffornis virescens and no species were related to any small fragment. This analysis has identified specialized Passerine species in many aspects (foraging substract, needs for nesting, rarity status), and it can be a valuable tool for detecting possible bioindicators.

Para avaliar o potencial de Passeriformes como bioindicadores de fragmentação florestal na Mata Atlântica, estudamos a avifauna da região serrana do Rio de Janeiro, utilizando capturas com redes de neblina entre 2001 e 2005. Foram amostradas seis áreas, sendo quatro pequenos fragmentos (de 4 a 64 ha) em áreas agrícolas (Teresópolis), uma mata secundária com cerca de 40 anos (440 ha - Miguel Pereira) e uma área de mata contínua de 10600 hectares (Parque Nacional da Serra dos Órgãos - PARNASO). A análise de espécies indicadoras e o teste de Monte Carlo foram empregados para que se verificassem as espécies mais associadas a cada local amostrado, considerando-se um mínimo de 30 por cento de indicação e valor significativo para o teste mencionado, utilizando-se somente espécies com 10 ou mais capturas. Foi amostrado um total de 30 espécies e, pela sua associação com a maior área (PARNASO), consideramos Sclerurus scansor, Mionectes rufiventris, Chiroxiphia caudata e Habia rubica como as melhores indicadoras. Cinco espécies foram mais capturadas não ao acaso na área de 440 ha: Conopophaga melanops, Myiobius barbatus, Myrmeciza loricata, Philydor atricapillus e Schiffornis virescens. Nenhuma espécie foi associada aos pequenos fragmentos. Como esta análise identificou espécies de Passeriformes especialistas em diversos aspectos (substrato de forrageio, locais de nidificação, status de raridade), ela pode ser uma ferramenta útil na detecção de possíveis bioindicadores.

Inhibition of the TEF/TEAD transcription factor activity by nuclear calcium and distinct kinase pathways.

Transcription enhancer factor (TEF/TEAD) is a family of four transcription factors that share a common TEA-DNA binding domain and are involved in similar cellular functions, such as cell differentiation and proliferation. All adult tissues express at least one of the four TEAD genes, so this family of transcription factors may be of widespread importance, yet little is known about their regulation. Here we examine the factors that regulate TEAD activity in CHO cells. RT-PCR indicated the presence of TEAD-1, TEAD-3, and both isoforms of TEAD-4, but not TEAD-2. Quantitative measurements showed that TEAD-4 is most abundant, followed by TEAD-3, then TEAD-1. We examined the relative effects of nuclear and cytosolic Ca(2+) on TEAD activity, since TEAD proteins are localized to the nucleus and since free Ca(2+) within the nucleus selectively regulates transcription in some systems. Chelation of nuclear but not cytosolic Ca(2+) increased TEAD activity two times above control. Inhibition of mitogen-activated protein kinase (MAPK) also increased TEAD activity, while cAMP decreased TEAD activity, and protein kinase C had no effect. Together, these results show that nuclear Ca(2+), MAPK, and cAMP each negatively regulate the activity of the TEAD transcription factor.

The effect of methimazole pretreatment on the efficacy of radioactive iodine therapy in Graves' hyperthyroidism: one-year follow-up of a prospective, randomized study.

The effect of antithyroid drugs on the efficacy of radioiodine (131I) treatment is still controversial. This study evaluated the effect of methimazole pretreatment on the efficacy of 131I therapy in Graves' hyperthyroidism. Sixty-one untreated patients were randomly assigned to receive 131I alone (32 patients) or 131I plus pretreatment with methimazole (30 mg/d; 29 patients). 131I was administered 4 d after drug discontinuation. The calculated 131I dose was 200 microCi/g thyroid tissue as estimated by ultrasound, corrected by 24-h radioiodine uptake. Serum TSH, T4, and free T4 were measured 4 d before 131I therapy, on the day of treatment, and then monthly for 1 yr. Considering cure as euthyroidism or hypothyroidism, based on free T4 measurement, approximately 80% of patients from both groups were cured 3 months after beginning 131I treatment. After 1 yr the groups were similar in terms of persistent hyperthyroidism (15.6% vs. 13.8%), euthyroidism (28.1% vs. 31.0%), or hypothyroidism (56.3% vs. 55.2%). Relapsed patients presented larger thyroid volume (P = 0.002), higher 24-h radioiodine uptake (P = 0.022), and T3 levels (P = 0.002). Multiple logistic regression analysis identified T3 values as an independent predictor of therapy failure. In conclusion, pretreatment with methimazole had no effect on either the time required for cure or the 1-yr success rate of 131I therapy.

Effect of methimazole pretreatment on serum thyroid hormone levels after radioactive treatment in Graves' hyperthyroidism.

Radioiodine (131I) is the preferred definitive treatment for Graves' hyperthyroidism. Pretreatment with antithyroid drugs is often used to avoid thyroid hormone discharge after 131I ablation. However, this may represent an unnecessary increase in risk and costs. Fifty-one patients with Graves' disease were randomly assigned to receive 131I alone (28 patients) or 131I plus pretreatment with methimazole (30 mg/day; 23 patients). Methimazole was interrupted 4 days before 131I therapy. Serum T4, free T4 (FT4), and T3 were measured on days -4 and -1, on the day of treatment, and on days 2, 5, 7, 14, 20, and 30. In patients receiving 131I alone, mean serum T4 levels did not change after therapy. Mean serum FT4 and T3 levels decreased significantly 5 days after 131I administration (15% and 18%, respectively). Serum T3 reached its lowest level on day 30 (38%). With pretreatment, mean serum T4, FT4, and T3 levels increased (38%, 39%, and 70%, respectively) after methimazole discontinuation and before 131I administration. After 131I, serum T4 levels peaked on day 7 (23% vs. treatment day; 70% vs. baseline); FT4 levels peaked on day 14 (53% vs. treatment day; 107% vs. baseline). The serum T3 concentration increased 9% on day 2 (85% vs. baseline) and decreased from day 14 (15%) to day 30 (21%). We conclude that interruption of antithyroid drugs causes a short term increase in serum thyroid hormone levels in patients with Graves' hyperthyroidism receiving 131I. Thyroid hormone levels stabilize or decrease during the first 30 days after 131I therapy.