Eficiência de máscaras cirúrgicas como equipamento de proteção respiratória contra aerossóis bacterianos

The use of masks is generally accepted as a means of protecting the individual against microbial pathogens that might be inhaled in unhealthy environments. The objective of this study was to evaluate the efficiency of disposable surgical masks sold in Brazil, against coliforms in aerosols emitted by the aerators of a sanitary sewage treatment station. The filtration efficiency varied from 50.9% to 99.9% for 6 masks from different sources.

Brosimum gaudichaudii Trecul (Moraceae): Da planta ao medicamento

The chemical, biological, pharmacological and toxicological study of plants used in medical treatments by different societies around the world has been intensifying over the years, primarily in the search for new herbal, homeopathic or even allopathic medicines. Motivated by this interest, we are investigating some Brazilian plant species, among them a tree, Brosimum gaudichaudii Trecul (Moraceae), found in Brazil's savannah-like prairies and scrub-forest (cerrado) and mesophytic forest. Several extracts have been made and separated into fractions and some compounds have been isolated - principally coumarins - and their respective structures analyzed by spectrophotometric and other methods. By collaborating with researchers in other fields, we have been able to carry out various bioassays and even basic clinical tests, namely: determination of anti-helminthic, anti-microbial, photosensitizing, anticancer and mutagenic activities, toxicological and pathogenic studies, with the aim of discovering a genuinely Brazilian herbal or homeopathic medicine.

Análise quantitativa de fluoretos nos alginatos para uso odontológico

In this study, the aim was to measure the concentration of fluoride ions in dental alginates and the quantity released from alginate molds immersed in milliQ water, 0.1N hydrochloric acid and artificial saliva. Two separate lots of each of seven brands of alginate commercially available in Brazil were analyzed: Avagel, Deguprint, Hydrogum, Orthoprint, Jeltrate, Jeltrate Plus and Jeltrate Chromatic. Fluoride was measured in each sample by direct potentiometry, using the combined fluoride-ion selective electrode. The brands with the highest fluoride concentrations were Hydrogum (7052.87 μg/g), Jeltrate Plus (6519.68 μg/g) and Orthoprint (6218.18 μg/g). Only in Hydrogum and Jeltrate were different fluoride concentrations found in lots one and two. The various materials showed differences in the amount of fluoride released from the molds into the immersion medium, the mean concentration being highest in Hydrogum and Orthoprint, in all three media. The immersion medium also influenced the release of fluoride, which was lower in saliva than in water and highest in acid. Considering that the concentrations of fluoride found in the alginates tested were high and that various sources of exposure to fluoride exist, there is a need for constant monitoring of alginates intended for dental use.

Efeito do tratamento com algumas vitaminas B na potencializaçã o do efeito antiinflamatório e antinociceptivo do diclofenaco e da talidomida

The effects of some B vitamins on chemical nociception in mice or paw edema in rats were investigated. A combination of thiamine (B1), pyridoxine (B6) and cyanocobalamin (B12), in doses of 100,100 and 5mg/kg, i.p., respectively, potentiated the inhibition by diclofenac or thalidomide of paw edema induced by carrageenin in rat. Antinociceptive effects of diclofenac and thalidomide inhibition of abdominal contortion were also potentiated by the combination of the vitamins B1, B6 and B12. Thiamine, pyridoxine and cyanocobalamin given singly were effective in potentiating antinociceptive effects of thalidomide, but only cyanocobalamin potentiated these effects of diclofenac, probably reflecting the differing mechanisms of action of the two drugs. The results document the positive influence of B vitamins on antinociceptive effects of diclofenac or thalidomide and support the use of B vitamins to shorten the treatment time and reduce the daily dose of anti-inflammatories.

Plantas do cerrado brasileiro com atividade contra Mycobacterium fortuitum

Mycobacterium fortuitum is a rapidly-growing species of bacteria, ubiquitous in the environment and related to important human mycobacterioses. It has been isolated from blood, abscesses, the endocardium and surgical and traumatic wounds. This mycobacterium is hard to treat, being recognized in the literature as resistant even to the drugs used in the treatment of tuberculosis. The objective of this study was to screen extracts prepared from plants of the Brazilian cerrado (extended savanna-like belt) with known activity against M. fortuitum, employing the Microplate Alamar Blue Assay (MABA) as the analytical method. Out of 26 extracts tested against M. fortuitum, the nonpolar extract of Quassia amara (in methylene dichloride) gave the best result (MIC 62.5μg/ mL), followed by the nonpolar extracts of Syngonanthus macrolepsis, Davilla elliptica and Turnera ulmifolia, with equal MICs of 125μg/ml. The polar extracts (in ethanol and methanol) obtained from the same plants were considered inactive, since the MIC values determined were above 500μg/mL and not significantly different from those of extracts from other plants, without known activity.

Antibiótico antifungico produzido por um estreptomiceto da região de Araraquara

With the significant increase in the incidence of invasive fungal infections during the last decade, mainly in patients with cancer, AIDS and other hospitalized patients who stay for long periods in intensive care units, there is an urgent need to screen for new antifungal agents possessing some advantages over known ones. This article reports a search in the field for a microorganism producing antibacterial and antifungal substances. Strains from soil samples collected in the region of Araraquara, Brazil, were isolated and analyzed for their antimicrobial potential against standard microorganisms (fungi Candida albicans and Aspergillus oryzae and bacteria Staphylococcus aureus and Escherichia coli). Out of the 64 strains isolated, 34 produced detectable antimicrobial activity. The streptomycete strain Ar4014 was chosen for further study, owing to its good antimicrobial activity against Candida albicans. Two of the fermentation media tested, 608-K and 602-B, were found to be best for the production and extraction of the antibiotic from Ar4014. After chromatographic separation of the crude extract on a silica column, the active fractions obtained showed UV-VIS absorption peaks characteristic of normal pentaenic antibiotics. The antibiotic was provisionally designated Ara 4014-75.

Photodegradation of sparfloxacin and isolation of its degradation products by preparative HPLC

Sparfloxacin, a third generation fluoroquinolone derivative, is a potent antibacterial agent active against a wide range of Gram-positive and Gram-negative organisms including Streptococcus pneuinoniae, Staphylococcus aureus, methicillin resistant S. aureus, Legionella spp., Mycoplasina spp., Chlamydia spp. and Mycobacterium spp. A drawback of fluoroquinolones is their photoreactivity. Sparfloxacin has been studied in terms of therapeutic activities. However, there are few published of analytical methods being applied to sparfloxacin. The aim in this study was to determine the photodegradation products of sparfloxacin, when submitted to UV light, and to characterize two of these products, designated SPAX-PDP1 and SPAX-PDP2. An accelerated study of stability in methanol solution was carried out by exposing a solution of sparfloxacin to UV light (peak wavelength 290 nm) for 36 hours at room temperature. The products were analyzed by NMR spectrophotometry, IR spectrometry and mass spectrophotometry. The results suggest that the products isolated here could be used to estimate the degradation of sparfloxacin in a stability study. However, the low activity exhibited by UV-irradiated sparfloxacin is a source of concern that demands further investigation of the mechanism of its photodegradation mechanism.

Byrsonima crassa Niedenzu (IK): Antimicrobial activity and chemical study

The methanolic extract of leaves from Byrsonima crassa, a Brazilian medicinal plant, was analyzed by CC and HPLC. Four constituents were isolated and identified as quercetin, methyl gallate, (-)-epigallocatechin gallate and quercetin-3-O-(2″-galloyl)-α-L-arabinopyranoside. The methanolic and hydromethanolic extract, as well as fractions, were evaluated regarding their possible antimicrobial activity using in vitro methods. Results showed that both extracts and fractions exhibited significant antimicrobial activity against all tested strains.

Fast preparative separation of flavones from capitula of Eriocaulon ligulatum (Vell.) L.B.Smith (Eriocaulaceae) by High-speed countercurrent chromatography (HSCCC)

High-speed countercurrent chromatography (HSCCC) is a leading method for the fast separation of natural products from plants. It was used for the preparative isolation of two flavone monoglucosides present in the capitula of Eriocaulon ligulatum (Veil.) L.B.Smith (Eriocaulaceae). This species, known locally as botão-dourado, is exported to Europe, Japan and North America as an ornamental species, constituting an important source of income for the local population of Minas Gerais State, Brazil. The solvent system, optimized in tests prior to the HSCCC run, consisted of the two phases of the mixture ethyl acetate: n-propanol: water (140:8:80, v/v/v), which led to the successful separation of 6-methoxyluteolin-7-O-β-D-allopyranoside and 6-methoxyapigenin-7-O-β-D-allopyranoside in only 3 hours. The two flavonoids were identified by NMR (1-D and 2-D) and ESI-MS, comparing their spectra with published data.

Análise térmica de esparfloxacino

Sparfloxacin, a third-generation fluoroquinolone, is a potent antibacterial agent against a wide range of Gram-positive and Gram-negative organisms, for example Streptococcus pneumonias, Staphylococcus aureus (including methicillin-resistant strains), Legionella spp., Mycoplasma spp., Chlamydia spp. and Mycobacterium spp. This compound has been submitted to thermal analysis and the results are presented here. The DSC curve of sparfloxacin has an endothermic peak that indicates a melting point at 276.5 °C. The DTA curve of the sample in synthetic air shows two exothermic peaks, at 341.6 and 579.2 °C, attributed to compound decomposition. In the TG curve, the loss of mass can be seen to occur in two steps between 285.5 and 645.3 °C. The DTA curve obtained in a nitrogen atmosphere shows an exothermic peak, with decomposition of sparfloxacin at 340.0 °C; from the corresponding TG plot, the loss of mass starts at 254.4 °C.

Quantitative analysis of potentially toxic metals in alginates for dental use

Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4mL concentrated HCI:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them.

Consumo de medicamentos por idosos segundo prescrição médica em Jaú-SP

This study was carried out in order to identify the interactions that occur most often between prescribed drugs as they are taken by elderly patients attending municipal public health centers in the city of Jaú, São Paulo State, Brazil. It is known that older people frequently have to live with chronic health problems, which oblige them to use the health service a great deal and to consume large quantities of medicines. When concomitant diseases are present, and polytherapy is being applied, the likelihood of adverse reactions and interactions between drugs increases. The population under study consisted of 148 persons aged 65 or more who frequented the pharmacy at the Núcleo de Gestão Assistencial (Municipal Health Centre, NGA25) in Jaú, between August and December 2004. Data were collected from medical prescriptions, the independent variables being the age and sex of the patient. For each patient, the pharmacological classes of drugs taken and drug-drug interactions were recorded. It was found that the mean numbers of drugs consumed were 3.8 among women and 3.9 among men. In terms of age, the highest number of drugs (4.2) was used in the group aged 75 to 84 years. The most frequently prescribed classes, in decreasing order, were: antihypertensives, 25.0%, heart drugs, 15.5%, diuretics, and anti-diabetic drugs, 10.7%. It was concluded that the classes most involved in drug-drug interactions were heart drugs, diuretics and antihypertensives. The most problematic active constituents were digoxin, amiodarone, frusemide, captopril, propranolol and nifedipine.

Analysis of susceptibility profile of Pseudomonas spp. and prevalence of bacterial samples from the surfaces of dental consulting-rooms

The aim of this research was to evaluate the susceptibility profile of Pseudomonas spp. and the prevalence of bacterial samples isolated from horizontal surfaces surrounding wash-basins used by dentists in several adjoined consulting-rooms, at points next to and at a distance from the basin, before and after surgical procedures. Our results showed a high percentage of Gram-positive cocci and Gram-negative bacilli; 34.66% were Staphylococcus spp. and 30.12% were non-fermentative Gram-negative bacilli among which Pseudomonas spp. (40.90%) was the commonest genus. Analysis of the susceptibility profile of Pseudomonas spp. isolates by determining the minimal inhibitory concentration (MIC) of 14 antibiotics showed a great variation among the strains and high rates of resistance to cefazolin, ceftazidime and aztreonan. Of the 14 antibiotics tested, 59.03% were found to be active against all the environmental isolates. Strains were resistant to aztreonan (62.82%), while susceptibility to third generation cephalosporins was variable.

Mixture of vitamin C, hesperidin and piperidol exposure in pregnancy: Maternal-fetal repercussions

To evaluate the reproductive performance and the development of their offspring on rat pregnancy. Wistar pregnant rats were gavaged with 0 mg/kg wb/day (control group, n = 20) and 166.5 mg/kg/day of a mixture of vitamin C, hesperidin and piperidol (experimental group, n = 20) during the organogenic period (from day 5 to 14 of pregnancy; positive vaginal smear = day 0). The female rats were killed on day 21 of pregnancy. The number of implantations, resorptions (dead embryos), and live/dead fetuses were counted for the analysis of the postimplantation loss rates. There was neither alteration in maternal reproductive performance, but it was verified an increase of the number of fetuses presenting dilated urether, hydronephrosis, and reduced ossification of skull due to the treatment of female rats with a mixture of vitamin C, hesperidin and piperidol, these abnormalities were considered transitory and may not interfere on offspring development. It was not verified other type of major malformation neither the appearance of fetuses presenting atrophy of upper limbs that it could be associated to use of this drug.

Thermoanalytical study of praziquantel-loaded PLGA nanoparticles

Polymeric nanoparticles have received great attention as potential controlled drug delivery systems. Biodegradable polymers has been extensively used in the development of these drug carriers, and the polyesters such as polylactic acid, polyglycolic acid and their copolymers as poly-lactide-co- glycolide are the most used, considering its biocompatibility and biodegradability. Thermal analysis techniques have been used for pharmaceutical substances for more than 30 years and are routine methods for screening drug-excipient interactions. The aim of this work is to use thermal analysis to characterize PLGA nanoparticles containing a hydrophobic drug, praziquantel. The results show that the drug is in an amorphous state or in disordered crystalline phase of molecular dispersion in the PLGA polymeric matrix and that the microencapsulation process did not interfere with the chemical structure of the polymer, mantaining the structural drug integrity.