Evaluation of the antimicrobial activity of Eucalyptus radiata essential oil against Escherichia coli strains isolated from meat products.

The present study sought to evaluate the antimicrobial and anti-adherent potential of Eucalyptus radiata essential oil against food-borne strains of Escherichia coli. The study was performed using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). In addition, the disk diffusion technique was used to evaluate the association of Eucalyptus radiata essential oil with synthetic antimicrobials. The Minimum Inhibitory Adherence Concentration (MIC) was also performed. The results revealed that E. radiata showed antimicrobial activity against the E. coli strains tested, with MIC values ranging from 500 µg/mL to 1000 µg/mL and MBC values ranging from 500 µg/mL to 1,024 µg/mL. As for the associations, it was observed that E. radiata oil exhibited a synergistic effect for some antibiotics, especially Ceftriaxone, with greater interference from the essential oil. Furthermore, it was effective in inhibiting the adherence of bacterial strains of E. coli, showing a more significant antibiofilm effect than the antibacterial agent 0.12% chlorhexidine digluconate. In summary, the essential oil of E. radiata showed antimicrobial potential against strains of E. coli of food origin, and can therefore, through in-depth studies, be used alone or in association with synthetic antimicrobials to combat infections caused by this pathogen.

Anaemia, Serum Iron Concentrations and δ-Aminolevulinate Dehydratase Activity in Laying Hens Infected Naturally by Salmonella Gallinarum.

The aim of this study was to evaluate anaemia, serum iron concentrations and δ-aminolevulinate dehydratase (ALA-D) activity in laying hens infected naturally by Salmonella Gallinarum and having severe hepatic lesions. Liver and serum samples were collected from 27 laying hens (20 infected and seven uninfected). The δ-ALA-D activity, haematocrit and serum iron concentrations were evaluated. There were significant decreases in δ-ALA-D activity, haematocrit and serum iron concentrations (P <0.01) in birds infected by S. Gallinarum when compared with uninfected birds. There was a positive correlation (P <0.001) between serum iron concentration, haematocrit (r(2) = 0.82) and δ-ALA-D activity (r(2) = 0.75). A positive correlation was also observed between δ-ALA-D activity and haematocrit (r(2) = 0.78; P <0.01). Liver samples showed moderate focal coagulative necrosis associated with infiltration of lymphoplasmacytic cells, macrophages and heterophils. The anaemia in the infected hens may be related to reduction in δ-ALA-D activity and serum iron concentrations, since both are important for haemopoiesis.

Effects of eugenol on resting tension of rat atria

In cardiac and skeletal muscle, eugenol (μM range) blocks excitation-contraction coupling. In skeletal muscle, however, larger doses of eugenol (mM range) induce calcium release from the sarcoplasmic reticulum. The effects of eugenol are therefore dependent on its concentration. In this study, we evaluated the effects of eugenol on the contractility of isolated, quiescent atrial trabeculae from male Wistar rats (250-300 g; n=131) and measured atrial ATP content. Eugenol (1, 3, 5, 7, and 10 mM) increased resting tension in a dose-dependent manner. Ryanodine [100 µM; a specific ryanodine receptor (RyR) blocker] and procaine (30 mM; a nonspecific RyR blocker) did not block the increased resting tension induced by eugenol regardless of whether extracellular calcium was present. The myosin-specific inhibitor 2,3-butanedione monoxime (BDM), however, reversed the increase in resting tension induced by eugenol. In Triton-skinned atrial trabeculae, in which all membranes were solubilized, eugenol did not change resting tension, maximum force produced, or the force vs pCa relationship (pCa=-log [Ca2+]). Given that eugenol reduced ATP concentration, the increase in resting tension observed in this study may have resulted from cooperative activation of cardiac thin filaments by strongly attached cross-bridges (rigor state).

Effects of eugenol on resting tension of rat atria.

In cardiac and skeletal muscle, eugenol (µM range) blocks excitation-contraction coupling. In skeletal muscle, however, larger doses of eugenol (mM range) induce calcium release from the sarcoplasmic reticulum. The effects of eugenol are therefore dependent on its concentration. In this study, we evaluated the effects of eugenol on the contractility of isolated, quiescent atrial trabeculae from male Wistar rats (250-300 g; n=131) and measured atrial ATP content. Eugenol (1, 3, 5, 7, and 10 mM) increased resting tension in a dose-dependent manner. Ryanodine [100 µM; a specific ryanodine receptor (RyR) blocker] and procaine (30 mM; a nonspecific RyR blocker) did not block the increased resting tension induced by eugenol regardless of whether extracellular calcium was present. The myosin-specific inhibitor 2,3-butanedione monoxime (BDM), however, reversed the increase in resting tension induced by eugenol. In Triton-skinned atrial trabeculae, in which all membranes were solubilized, eugenol did not change resting tension, maximum force produced, or the force vs pCa relationship (pCa=-log [Ca2+]). Given that eugenol reduced ATP concentration, the increase in resting tension observed in this study may have resulted from cooperative activation of cardiac thin filaments by strongly attached cross-bridges (rigor state).

Characterization of ecto-ATPase activity in the surface of LLC-PK1 cells and its modulation by ischemic conditions.

BACKGROUND: The concentration of extracellular nucleotides is regulated by enzymes that have their catalytic site facing the extracellular space, the so-called ecto-enzymes. METHODS: We used LLC-PK1 cells, a well-characterized porcine renal proximal tubule cell line, to biochemically characterize ecto-ATPase activity in the luminal surface. The [γ-(32)P]Pi released after reaction was measured in aliquots of the supernatant by liquid scintillation. RESULTS: This activity was linear with time up to 20min of reaction and stimulated by divalent metals. The ecto-ATPase activity measured in the presence of 5mM MgCl(2) was (1) optimum at pH 8, (2) insensitive to different inhibitors of intracellular ATPases, (3) inhibited by 1mM suramin, an inhibitor of ecto-ATPases, (4) sensitive to high concentrations of sodium azide (NaN(3)) and (5) also able to hydrolyze ADP in the extracellular medium. The ATP:ADP hydrolysis ratio calculated was 4:1. The ecto-ADPase activity was also inhibited by suramin and NaN(3). The dose-response of ATP revealed a hyperbolic profile with maximal velocity of 25.2±1.2nmol Pixmg(-1)xmin(-1) and K(0.5) of 0.07±0.01mM. When cells were submitted to ischemia, the E-NTPDase activity was reduced with time, achieving 71% inhibition at 60min of ischemia. CONCLUSION: Our results suggest that the ecto-ATPase activity of LLC-PK1 cells has the characteristics of a type 3 E-NTPDase which is inhibited by ischemia. GENERAL SIGNIFICANCE: This could represent an important pathophysiologic mechanism that explains the increase in ATP concentration in the extracellular milieu in the proximal tubule during ischemia.

The role of HLA antigens in the development of paracoccidioidomycosis.

BACKGROUND: Paracoccidioidomycosis is a systemic granulomatous disease that involves primarily the lungs and may disseminate to other organs and systems. It is caused by Paracoccidioides brasiliensis, a fungus that exhibits reversible thermal dimorphism and whose natural habitat is presently unknown. There are two main clinical forms: the acute (subacute) juvenile form and the chronic adult form. The former runs a more rapid course and is more severe than the latter. This mycosis is found throughout Latin America. Brazil accounts for 80% of reported cases. Presumably P. brasiliensis thrives in humid and hot places, especially near forests or farms. The infection is endemic in certain areas, especially in Brazil, Colombia and Venezuela, where nearly 100% of the population show cutaneous paracoccidioidina positive skin tests, indicating previous contact with the fungus, although a small percentage show clinical manifestations of the disease. METHODS: We compared the expression of HLA class I antigens in a healthy group (control) and in a group of patients with paracoccidioidomycosis (chronic adult form) using the Terasaki lymphocytotoxicity test modified by Amos for HLA antigen analysis. AIMS: To discover indications of whether or not individual susceptibility to P. brasiliensis might depend on some specific immunological defect. RESULTS: There is no evidence of association between a specific HLA antigen and paracoccidioidomycosis in the subjects studied. Further investigations are recommended.

Incidência de parasitoses em escolares da Escola Municipal de Educaçäo Infantil "Sant'Ana Itatiaia", Juiz de Fora-MG e sua possível correlaçäo com a qualidade da água para consumo / Parasitosis incidence in children from EMEI \"Sant'Ana Itatiaia\", Juiz de Fora-MG, Brazil and possible relationship with the presence of the parasites in source of water

SÄo apresentados os resultados de 23 exames parasitológicos de fezes coletadas com conservador MIF e analisadas pelo método preconizado por Hoffman, Pons & Janer no Laboratório de Saúde Pública/FFB/UFJF e, de 9 análises bacteriológicas da água consumida na residência de 7 escolares da EMEI "Sant'Ana Itatiaia" - Juiz de Fora - MG, segundo a metodologia empregada no Laboratório de Análise de Alimentos e Saneamento de Aguas/FFB/UFJF. O estudo foi desenvolvido nos meses de Agosto a Outubro de 1994 em escolares com idade entre 4 e 6 anos e de ambos os sexos. A percentagem das amostras de fezes positivas foi de 56,52 porcento e a de negativas de 43,48 porcento. A etiologia das enteroparasitoses de maior incidência na populaçäo estudada foi: Entamoeba coli (38,89 porcento), Ascaris lumbricoides (27,78 porcento), Trichuris trichiura (11,11 porcento), Giardia lamblia (11,11 porcento) e Entamoeba histolytica (11,11 porcento). Das amostras analisadas, 17,39 porcento revelaram a presença de mais de um parasita. Apesar de näo ter sido possível correlacionar a etiologia das enteroparasitoses com uma provável veiculaçäo hídrica das mesmas, verificou-se que 61,11 porcento das amostras de fezes examinadas revelaram a presença de protozoários e, ainda, que 60 porcento das amostras de água oriundas de outras fontes que näo o abastecimento público, foram consideradas impróprias para o consumo como bebida. Tais dados reforçam a necessidade de medidas administrativas eficientes para a implantaçäo e melhoria do saneamento básico, pois näo existe saúde sem infra-estrutura sanitária

Morphology of rat submandibular gland acinar secretory granules and their alteration during the acute phase of experimental Chagas' disease

In a morphometric study at the electron microscope level immature submandibular glands of 8 normal male Holtzman rats were compared to those of 12 rats (46 days old) infected with the Y strain of Trypanosoma cruzi at day 18 of infection. In the fasted animals, the acinar cells of controls exhibited a variety of morphological types of immature secretory granules with lamellar substructure composed of swirling cords of electron-dense material, whereas in the infected rats mature secretory granules containing dense aggregates of short or long filamentous material were more abundant. These results suggest and acceleration of acinar maturation in infected animals

Cystatin S in secretory granules fractions isolated from submandibular gland of infected rats by Trypanosoma cruzi.

We have measured the relative concentrations of cysteine proteinase in the granular fractions of submandibular glands of control and Trypanosoma cruzi infected rats by using a sensitive solid phase ELISA. Gland samples were homogenized in 0.34 M sucrose and 0.5 mM EDTA in 10 mM HEPES buffer at a pH of 7.4. The extract was centrifuged and filtered through Millipore filters to prepare a purer granular fraction. Immunochemical studies using antibody against cystatin S and electrophoretic analysis showed higher cystatin S levels in infected rats than in control. The role of this inhibitor during acute phase of Chagas disease is discussed.

Induction of synthesis of the rat cystatin S protein by the submandibular gland during the acute phase of experimental Chagas disease

Rats experimentally infected with Trypanosoma cruzi Y strain exhibited hypertrophy of the submandibular gland at 18 days after infection.SDS-PAGE of infected rats saliva revealed the presence of an additional band with an apparent molecular weight of about 13KDa. Electrophoresis of protein salivaand immunochemical analysis with antibody against rat cystatin S confirmed that the protein was identical to that induced by beta adrenergic stimulation

Induction of synthesis of the rat cystatin S protein by the submandibular gland during the acute phase of experimental Chagas disease.

Rats experimentally infected with Trypanosoma cruzi Y strain exhibited hypertrophy of the submandibular gland at 18 days after infection. SDS-PAGE of infected rats saliva revealed the presence of an additional band with an apparent molecular weight of about 13KDa. Electrophoresis of protein saliva and immunochemical analysis with antibody against rat cystatin S confirmed that the protein was identical to that induced by beta adrenergic stimulation.

Vacinacao de adolescentes em atendimento ambulatorial. / Vaccination of adolescents in ambulatory care

O estudo apresentado tem por objetivo caracterizar a historia de vacinacao em grupo de 108 adolescentes atendidos em uma unidade ambulatorial a eles destinada. Observou-se que 77,8% dos adolescentes tinham vacinacao incompleta e que 52,8% nao tinham recebido esquema com as vacinas disponiveis nas instituicoes publicas de saude. Os dados chamam a atencao para falhas importantes na vacinacao de adolescentes contra difteria, tetano e paralisia infantil e aponta para a necessidade de identificar os adolescentes susceptiveis de contrair as molestias proprias da infancia