Molecular detection of tick-borne bacterial agents in Brazilian and exotic captive carnivores

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of Cassava Wastewater Treated Anaerobically with Alkaline Agents as Fertilizer for Maize (Zea mays L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Topliss method in the optimization of salicylic acid derivatives as potential antimycobacterial agents

The Topliss method was used to guide a synthetic path in support of drug discovery efforts toward the identification of potent antimycobacterial agents. Salicylic acid and its derivatives, p-chloro, p-methoxy, and m-chlorosalicylic acid, exemplify a series of synthetic compounds whose minimum inhibitory concentrations for a strain of Mycobacterium were determined and compared to those of the reference drug, p-aminosalicylic acid. Several physicochemical descriptors (including Hammett's sigma constant, ionization constant, dipole moment, Hansch constant, calculated partition coefficient, Sterimol-L and -B-4 and molecular volume) were considered to elucidate structure-activity relationships. Molecular electrostatic potential and molecular dipole moment maps were also calculated using the AM1 semi-empirical method. Among the new derivatives, m-chlorosalicylic acid showed the lowest minimum inhibitory concentration. The overall results suggest that both physicochemical properties and electronic features may influence the biological activity of this series of antimycobacterial agents and thus should be considered in designing new p-aminosalicylic acid analogs.

Ruthenium (II) phosphine/picolinate complexes as antimycobacterial agents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Synthesis of 4-aminoquinoline analogues and their platinum(II) complexes as new antileishmanial and antitubercular agents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ruthenium(II) phosphine/diimine/picolinate complexes: Inorganic compounds as agents against tuberculosis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Potential tuberculostatic agents: Micelle-forming copolymer poly(ethylene glycol)-poly(aspartic acid) prodrug with isoniazid

With the objective of obtaining slow-acting isoniazid derivatives, of potential use as chemoprophylactics or chemotherapeutics in tuberculosis, the micelle-forming copolymer of poly(ethylene glycol)-poly(aspartic acid) prodrug with isoniazid was synthesized. The derivative obtained was found to be active in Mycobacterium Il(tuberculosis culture, with a minimal inhibitory concentration (MIC) 5.6 times lower than that of the tuberculostatic drug.

Potential tuberculostatic agents. Topliss application on benzoic acid [(5-nitro-thiophen-2-yl)-methylene]-hydrazide series

Nitroaromatic compounds such as nifuroxazide are used in many human enteropathogenic bacteria infections without causing an increase in the plasmidial antibiotic resistance of the aerobic Gram-negative intestinal Enterobacteriaceae. For these reasons, these compounds have been synthesized using the rational approach of Topliss' decision tree. Generally. this approach allows us to obtain the most active derivative from the series in a few steps. These compounds were tested against Mycobacterium tuberculosis in vitro and the most active of the series identified. A new lead for potential tuberculostatic activity has been predicted and will be used in further QSAR studies. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Injuries and envenoming by aquatic animals in fishermen of Coxim and Corumbá municipalities, state of Mato Grosso do Sul, Brazil: identification of the causative agents, clinical aspects and first aid measures

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Involvement of GABA(A)-benzodiazepine receptor in the anxiolytic effect induced by hexanic fraction of Rubus brasiliensis

To investigate the ability of hexanic ethanolic fraction of Rubus brasiliensis Martius (Roseceae), to induce anxiolytic effect and also the possible involvement of the GABA(A)-benzodiazepine receptor complex, male Wistar rats and Swiss mice behaviour were tested in the elevated plus maze (EPM). All the doses of the extract, 50, 100 and 150 mg/kg, administered per gavage (vo), 30 min before the behavioural evaluation, induced an anxiolytic effect expressed by: increased number of entries in and time spent in the open arms and percentage of open arm entries: and decreased number of entries and time spent in the closed arms. The treatment of mice with flumazenil (Ro 15-1788), 0.5, 1.0 and 1.5 mg/kg, i.p., 15-min before the administration of hexanic fraction, 100 mg/kg, vo, blocked the hexanic fraction-induced anxiolytic effect. The LD50 for the hexanic fraction was 1512 mg/kg. In conclusion, it was shown that the hexanic fraction of R. brasiliensis induced an anxiolytic effect in rats and mice. This effect can be attributed to a liposoluble principle with low toxicity which may be acting as an agonist on GABA(A)-benzodiazepine receptor complex. (C) 1998 Elsevier B.V. Ireland Ltd. All rights reserved.

Assessment of genetic damage induced by dental bleaching agents on mouse lymphoma cells by single cell gel (comet) assay

Dental bleaching is a simple and conservative procedure for aesthetic restoration of vital discoloured teeth. However, dental bleaching agents may represent a hazard to human health, especially by causing DNA strand breaks. Genotoxicity tests form an important part of cancer research and risk assessment of potential carcinogens. In the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. Six commercial dental bleaching agents (Clarigel Gold - Dentsply; Whitespeed - Discus Dental; Nite White - Discus Dental; Magic Bleaching - Vigodent; Whiteness HP - FGM and Lase Peroxide - DMC) were exposed to mouse lymphoma cells in vitro. The results pointed out that all dental bleaching agents tested contributed to the DNA damage as depicted by the mean tail moment. Clear concentration-related effects were obtained for DNA damaging, being the strongest effect observed at the highest dose of the hydrogen peroxide (Whiteness HP and Lase Peroxide, at 35% concentration). on the contrary, Whitespeed (Discus Dental) induced the lowest level of DNA breakage. Taken together, these results suggest that dental bleaching agents may be a factor that increases the level of DNA damage as detected by the single cell gel (comet) assay.

Lack of effect of prior treatment with fluoride on genotoxicity of two chemical agents in vitro

The goal of this study was to investigate the ability of fluoride to modulate the genotoxic effects induced by the oxidative agent hydrogen peroxide (H2O2) and the alkylating agent methyl methanesulfonate (MMS) in vitro by the single-cell gel ( comet) assay. Chinese hamster ovary cells were exposed in culture for 1 h at 37 degrees C to sodium fluoride at 7-100 mu g/ml. NaF-treated and control cells were then incubated with 0-10 mu M MMS in phosphate-buffered saline (PBS) for 15 min at 37 degrees C, or 7-100 mu M H2O2 in distilled water for 5 min on ice. Negative control cells were treated with PBS for 1 h at 37 degrees C. Clear concentration-related effects were observed for the two genotoxins. Increase of DNA damage induced by either MMS or H2O2 was not significantly altered by pretreatment with NaF. The data indicate that NaF does not modulate alkylation-induced genotoxicity or oxidative DNA damage as measured by the single-cell gel ( comet) assay. Copyright (c) 2007 S. Karger AG, Basel

Letinula edodes (Berk.) Pegler (Shiitake) modulates genotoxic and mutagenic effects induced by alkylating agents in vivo

We evaluated the antimutagenic effect of Letinula edodes (Berk.) Pegler (Shiitake) on the frequency of micronuclei in mice treated with N-ethyl-N-nitrosourea (ENU) or cyclophosphamide (Cl?). Mice were orally (gavage) pretreated for 15 consecutive days with solutions of Shiitake (0.6 ml per day, gavage) prepared at three different temperatures: 4, 21 (RT), and 60 degreesC. Then, the animals were intraperitoneally injected on day 15 with CP (25 or 50 mg/kg) or ENU (50 mg/kg) and killed 24 or 48 h after treatment for evaluation of micronucleated polychromatic erythrocytes (MNPCEs) in bone marrow and micronucleated reticulocytes (MNRETs). A mixture of L. edodes lineages (LE 95/016, 96/14, 96/17, 96/22, 96/23, 97/27, and 97/28) significantly decreased the frequencies of MNPCEs and MNRETs induced by CP (25 and 50 mg/kg). When a single lineage from the mixture (LE 96/17) was tested we also found a significant reduction in the frequencies of MNPCEs and MNRETs induced by both CP or ENU (50 mg/kg). The comet assay was also performed 3 h after ENU treatment using mice pretreated with the single lineage (LE 96/17) of L. edodes. The results showed a high degree of variability with some indications of an antigenotoxic effect. Taken together, our data show that solutions from Shiitake inhibit in vivo mutagenicity of CP and ENU. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Distribution of contagious and environmental mastitis agents isolated from milk samples collected from clinically health buffalo cows between brazilian dry and rainy seasons of the year

The present study was performed to evaluate the microbiological characteristics of clinically health quarters submitted to milking and also to observe the distribution of contagious and environmental agents between brazilian dry and rainy seasons of the year. During nine months 734 quarters from 37 buffalo cows were submitted monthly to udder inspection, palpation and strip cup test before milking. 734 asseptic milk samples were inoculated in 10% ovine blood agar and in MacConkey agar media, then incubated for 72 hours at 37 C. Among the 580 isolated microrganisms, 182 (31,38%) were recovered from samples collected during the rainy season and 398 (68,62%) from the dry season. In the rainy period the most prevalent agents were: bacteria from the genus Corynebacterium sp (53,30%), Staphylococcus sp (19,78%) and Rhodococcus equi (13,74%). In the dry period, the commonest ones were: Corynebacterium sp (44,97%), Staphylococcus sp (18,84%) and Micrococcus sp (9,55%). The results demonstrated that the methods used to select health quarters in brazilian dairy buffalo farms allow the transmission of contagious bacteria during both seasons of the year, maintaining agents known to cause mainly subclinical inflammatory reactions that compromise cronically the physiology and production of the mammary gland.

GABA(A) receptor activation in the lateral parabrachial nucleus induces water and hypertonic NaCl intake

Inhibitory serotonergic and cholecystokinergic mechanisms in the lateral parabrachial nucleus and central GABAergic mechanisms are involved in the regulation of water and NaCl intake. In the present study we investigated if the GABA(A) receptors in the lateral parabrachial nucleus are involved in the control of water, NaCl and food intake in rats. Male Holtzman rats with stainless steel cannulas implanted bilaterally into the lateral parabrachial nucleus were used. Bilateral injections of muscimol (0.2 nmol/0.2 mu l) into the lateral parabrachial nucleus strongly increased 0.3 M NaCl (20.3 +/- 7.2 vs. saline: 2.6 +/- 0.9 ml/180 min) without changing water intake induced by the treatment with the diuretic furosemide combined with low dose of the angiotensin converting enzyme inhibitor captopril s.c. In euhydrated and satiated rats, bilateral lateral parabrachial nucleus injections of muscimol (0.2 and 0.5 nmol/0.2 0) induced 0.3 M NaCl intake (12.1 +/- 6.5 and 32.5 +/- 7.3 ml/180 min, respectively, vs. saline: 0.4 +/- 0.2 ml/180 min) and water intake (5.2 +/- 2.0 and 7.6 +/- 2.8 ml/ 180 min, respectively, vs. saline: 0.8 +/- 0.4 ml/180 min), but no food intake (2 +/- 0.4 g/240 min vs. saline: 1 +/- 0.3 g/240 min). Bilateral lateral parabrachial nucleus injections of the GABAA antagonist bicuculline (1.6 nmol/0.2 mu l) abolished the effects of muscimol (0.5 nmol/0.2 mu l) on 0.3 M NaCl and water intake. Muscimol (0.5 nmol/0.2 mu l) into the lateral parabrachial nucleus also induced a slight ingestion of water (4.2 +/- 1.6 ml/240 min vs. saline: 1.1 +/- 0.3 ml/240 min) when only water was available, a long lasting (for at least 2 h) increase on mean arterial pressure (14 +/- 4 mm Hg, vs. saline: -1 +/- 1 mm Hg) and only a tendency to increase urinary volume and Na+ and K+ renal excretion. Therefore the activation of GABAA receptors in the lateral parabrachial nucleus induces strong NaCl intake, a small ingestion of water and pressor responses, without changes on food intake. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.