Helminth Parasites and Diet of Leptodactylus Petersii (Steindachner, 1864) (Anura: Leptodactylidae) from Amapá State, Eastern Amazon, Brazil.

Leptodactylus petersii is a species of anuran found in both terrestrial and aquatic habitats and occurs from South America to southern North America and the West Indies. Studies involving the fauna of anuran parasites offer complementary information related to ecology. Thus, since there are few studies on the natural history of this species, this research aims to analyze the diet and the presence of endoparasitic helminths of Leptodactylus petersii from the state of Amapá, Brazil. We found 10 different taxonomic categories of prey in stomach contents, with the categories Hymenoptera (Formicidae) with 32.26 % (n = 12) being the most representative. Among the 12 individuals of L. petersii that were analyzed for helminth parasites, 83.3 % were infected with at least one species of helminths allocated to Phylum Nematoda. Our results report a new occurrence site for Rhabdias breviensis, originally described for Leptodactylus petersii in the state of Pará, as well as the second report of Ortleppascaris sp. in Brazil.

Structure, microstructure and magnetic investigation of the hexagonal δ-FeSe nanophase produced by mechanochemical synthesis.

We present a systematic structural, microstructural and magnetic characterization of the hexagonal δ-FeSe nanophase produced by a simple one-step mechanochemical synthesis route, by using conventional X-ray powder diffraction (XRPD), Rietveld refinement, transmission electron microscopy (TEM) and magnetometry techniques. We observed the simultaneous formation of tetragonal ß-FeSe and δ-FeSe after 3 h of milling (with minor amounts of unreacted iron), followed by complete ß-FeSe → δ-FeSe phase transition as milling time increases to 6 h (no unreacted iron). The average crystallite size of the δ-FeSe phase of about 16 nm after 3 h milling time decreases by about 31% up to the final milling time (24 h). TEM images and electron diffraction patterns confirm the nanometric size of the crystalline domains in the irregularly-shaped agglomerated particles. Two ferromagnetic phases with distinct coercivity spectra were assumed here by considering an assembly of randomly-oriented weakly-anisotropic ferromagnetic particles, mixed at a 4 to 6 volume ratio with other randomly-oriented ferromagnetic grains. Four years after synthesis, the aged samples milled for less than 9 h revealed a certain amount of the ß-FeSe phase that slightly affects the δ-FeSe (micro)structure but causes some variations (decreasing) in magnetic parameters. Milling times as long as 12 h were shown to be necessary to guarantee the δ-FeSe nanophase stability and to retain its magnetic properties over time.

Nanosized tetragonal ß-FeSe phase obtained by mechanical alloying: structural, microstructural, magnetic and electrical characterization.

Nanocrystalline tetragonal ß-FeSe phase was prepared mechanochemically using ball milling procedures in an inert atmosphere, starting from Fe x Se powder mixtures with x = 1.00, 1.25 and 1.50, with x = 1.25 and 1.50 leading to more than 93% of pure phase after annealing at 400 °C for 1 hour under vacuum. X-ray powder diffraction provides information on phase formation and phase transitions with milling time and temperature. The Rietveld method was used to refine the crystal structure, including the z coordinate of Se and occupancies, to determine the microstructure and to assess the amount of contaminant phases observed. Lattice contraction is found in the ab-plane more than along the c-axis, the small average size of crystalline domains (<22 nm) and the high microstrain (>1%) indicate the formation of highly strained nanoparticles. Magnetic and electrical characterization showed a poor superconductivity at 4 K and semiconducting properties only for thermally treated samples. These observations are explained by the presence of ferromagnetic impurity phases (residual Fe, hexagonal δ-FeSe phase and monoclinic Fe3Se4), but other effects caused by the mechanochemical synthesis must be considered, such as small average size, large/non-uniform size distribution and high microstrain of the nanosized tetragonal ß-FeSe phase. The increase of the ß-FeSe phase content with increasing storage time (ageing) above a few days to months in air, at RT and in the dark was observed for all as-milled samples. Preliminary data on the ageing effect are shown while a systematic study on this is in progress and will be presented elsewhere.

Cubic PdNP-based air-breathing cathodes integrated in glucose hybrid biofuel cells.

Cubic Pd nanoparticles (PdNPs) were synthesized using ascorbic acid as a reducing agent and were evaluated for the catalytic oxygen reduction reaction. PdNPs were confined with multiwalled carbon nanotube (MWCNT) dispersions to form black suspensions and these inks were dropcast onto glassy carbon electrodes. Different nanoparticle sizes were synthesized and investigated upon oxygen reduction capacities (onset potential and electrocatalytic current densities) under O2 saturated conditions at varying pH values. Strong evidence of O2 diffusion limitation was demonstrated. In order to overcome oxygen concentration and diffusion limitations in solution, we used a gas diffusion layer to create a PdNP-based air-breathing cathode, which delivered -1.5 mA cm(-2) at 0.0 V with an onset potential of 0.4 V. This air-breathing cathode was combined with a specially designed phenanthrolinequinone/glucose dehydrogenase-based anode to form a complete glucose/O2 hybrid bio-fuel cell providing an open circuit voltage of 0.554 V and delivering a maximal power output of 184 ± 21 µW cm(-2) at 0.19 V and pH 7.0.

Dissolution enhancement of Deflazacort using hollow crystals prepared by antisolvent crystallization process.

Deflazacort (DFZ), a derivate of prednisolone, is a poorly soluble drug which has been proposed to have major advantages over other corticosteroids. Poorly soluble drugs present limited bioavailability due to their low solubility and dissolution rate and several strategies have been developed in order to find ways to improve them. In general, pharmaceutical laboratories use a micronized process to reduce the particle size in order to increase the dissolution of the drugs. However, this process causes changes such as polymorphic transitions, particle agglomeration and a reduction in fluidity and wettability. These solid-state properties affect the dissolution behavior and stability performance of drugs. Crystallization techniques are widely used in the pharmaceutical industry and antisolvent crystallization has been used to obtain ultrafine particles. In this study, DFZ was investigated in terms of its antisolvent crystallization in different solvents and under various preparation conditions (methanol/water ratio, stirring and evaporation rate, etc.), in order to compare the physicochemical properties between crystallized samples and raw materials available on the Brazilian market with and without micronization. Crystalline structure, morphology, and particle size, and their correlation with the Intrinsic Dissolution Rate (IDR) and dissolution profile as relevant biopharmaceutical properties were studied. Crystallization conditions were achieved which provided crystalline samples of hollow-shaped crystals with internal channels, which increased the dissolution rate of DFZ. The antisolvent crystallization process allowed the formation of hollow crystals, which demonstrated a better dissolution profile than the raw material (crystalline and micronized), making this a promising technique as a crystallization strategy for improving the dissolution and thus the bioavailability of poorly soluble drugs.

Effects of photoacoustic measurements on a nanostructured ZnSe mechanically alloyed.

Zinc-blende ZnSe powder, with particles containing nanometric grains, was prepared using the mechanical alloying technique, from an equiatomic mixture of elemental Zn and Se powders. An important interfacial component was observed in the as-milled powder, which affects its thermal and optical properties. In order to obtain a high-quality zinc-blende ZnSe powder an annealing process was applied. The structural properties of both as-milled and annealed powders were characterized by an x-ray diffraction technique. The effects of defect centers on the optical band gap of both as-milled and annealed zinc-blende ZnSe powders were studied through optical absorbance measurements. The results showed a substantial broadening and a shift of the band gap energy to lower values in the as-milled powder, while for the annealed sample no effects were observed. For the annealed sample, the measured band gap energy value is in good agreement with those reported in the literature. A sequence of photoacoustic absorption measurements of the as-milled ZnSe sample showed that the absorbed energy promotes a structural relaxation. This relaxation causes a change in the heat transfer mechanism from thermal diffusion to thermoelastic bending and a reduction in the thermal diffusivity values. Similar measurements of the annealed nanostructured ZnSe sample showed the thermal diffusivity value to have a high degree of stability, and to be in good agreement with values reported in the literature.

The pressure-induced phase transition of mechanically alloyed nanocrystalline GaSb.

Ga K-edge energy dispersive x-ray absorption spectroscopy and Raman spectroscopy measurements were employed to follow the pressure-induced semiconductor-metal phase transition of nanocrystalline GaSb produced by mechanical alloying up to 26 GPa. The results showed a slight increase of the phase transition pressures for both as-milled (8 GPa) and annealed (10 GPa) GaSb samples, as compared to that for the bulk one. The extended x-ray absorption fine structure analysis of the zinc blende (ZB) pressure domain (<10 GPa) showed that the microscopic compressibility of the bonds in the as-milled/annealed samples is higher/lower than the crystalline bulk modulus (56 GPa). The comparison between x-ray absorption near edge structure regions of the spectra and multiple scattering calculations suggests that the ZB structure evolves to a short-range chemically ordered ß-Sn structure for pressures as high as 8 GPa. Raman measurements confirm the semiconductor-metal phase transitions of ZB-GaSb between 8 and 11 GPa for both as-milled and annealed samples, showing that the semiconductor character was not recovered on releasing the pressure down to 3.9 and 1.8 GPa, indicating a very strong hysteresis effect (or even irreversible transitions). The well-known transverse effective charge reduction with pressure was also observed. Furthermore, resonance behaviour is clearly seen for transverse optical phonons and the resonance maxima peak occurs at about 1.2 GPa, corresponding to 2.11 eV in the E(1) scale, smaller by 0.3 eV than the incident photon energy.

Structural and photoacoustic studies of mechanically alloyed Ga(40)Sb(38)Se(22) powder.

GaSb, GaSe and Ga(2)Se(3) alloys were produced by the mechanical alloying technique. Their structural, thermal and optical properties were studied. Some of the results obtained have been reported in some papers referenced here. As an extension to those studies, some mixtures of elemental Ga, Sb and Se powders are now being investigated. Starting from a mixture with nominal Ga(62)Sb(27)Se(11) composition, 9 h of milling resulted in a final product with Ga(40)Sb(38)Se(22) composition and containing nanometric cubic GaSb and an amorphous GaSe phase. Part of this as-milled sample was annealed in order to study the amorphous-crystalline phase transformation. The crystalline cubic GaSb, hexagonal and rhombohedral GaSe phases form the measured x-ray diffraction (XRD) pattern for the annealed sample. The structural and thermal properties of both as-milled and annealed samples were studied by x-ray diffraction, differential scanning calorimetry and photoacoustic spectroscopy (PAS) techniques. We observe that the thermoelastic bending contribution is dominant in the PAS signal for both as-milled and annealed samples. The thermal diffusivity value was calculated for both samples by fitting the PAS signal phase.

Mechanical alloying: a pressure induced reaction for obtaining zinc blende GaSb and multiphase states.

The cubic zinc blende GaSb phase was produced by a mechanical alloying technique, which is a solid state route based on the action of non-hydrostatic pressures. The thermal stability of this phase was tested using the differential scanning calorimetry technique and, in order to clarify the results, an annealing process was performed. Comparing x-ray diffraction patterns for as-prepared and annealed samples, the improvement in crystallinity of the cubic phase and Sb segregation and/or crystallization can be easily seen. Optical phonons frequencies were measured for both as-milled and annealed samples by means of the Raman spectroscopy technique. Raman profiles of as-milled samples showed typical zinc blende GaSb optical modes and revealed new features that can be associated with multiphase states.

Reverse Monte Carlo simulations, Raman scattering, and thermal studies of an amorphous Ge30Se70 alloy produced by mechanical alloying.

The short- and intermediate-range orders of an amorphous Ge30Se70 alloy produced by mechanical alloying were studied by reverse Monte Carlo simulations of its x-ray total structure factor, Raman scattering, and differential scanning calorimetry. The simulations were used to compute the G(Ge-Ge) (RMC)(r), G(Ge-Se) (RMC)(r), and G(Se-Se) (RMC)(r) partial distribution functions and the S(Ge-Ge) (RMC)(K), S(Ge-Se) (RMC)(K), and S(Se-Se) (RMC)(K) partial structure factors. We calculated the coordination numbers and interatomic distances for the first and second neighbors and the bond-angle distribution functions Theta(ijl)(cos theta). The data obtained indicate that the structure of the alloy has important differences when compared to alloys prepared by other techniques. There are a high number of Se-Se pairs in the first shell, and some of the tetrahedral units formed seemed to be connected by Se-Se bridges.

Structural study of Cu(2-x)Se alloys produced by mechanical alloying.

The crystalline structures of the superionic high-temperature copper selenides Cu(2-x)Se (0 < x < 0.25) produced using mechanical alloying were investigated using X-ray diffraction (XRD). The measured XRD patterns showed the presence of peaks corresponding to the crystalline superionic high-temperature alpha-Cu(2)Se phase in the as-milled sample, and its structural data were determined by means of a Rietveld refinement procedure. After heat treatment in argon at 473 K for 90 h, this phase transforms to the superionic high-temperature alpha-Cu(1.8)Se phase, whose structural data were also determined by Rietveld refinement. In this phase, a very low occupation of the trigonal 32(f) sites ( approximately 3%) by Cu ions is found. In order to explain the evolution of the phases in the samples, two possible mechanisms are suggested: (i). the high mobility of Cu ions in superionic phases and (ii). the important diffusive processes in the interfacial component of samples produced by mechanical alloying.

Novel allelic variants of Mycobacteria isolated in Brazil as determined by PCR-restriction enzyme analysis of hsp65.

Human isolates of Mycobacterium collected in 16 different states of Brazil were submitted to PCR-restriction analysis (PRA) of a 439-bp fragment of the hsp65 gene with HaeIII and BstEII. Fourteen allelic variants not described in clinical isolates so far were observed among 36 (10%) of 356 Brazilian strains, including a new pattern for Mycobacterium scrofulaceum, M. intracellulare, and M. flavescens, two new patterns for M. fortuitum, three new patterns each for M. gordonae and M. terrae, and one new pattern for M. avium complex-like strains. Two unidentified strains each also presented a new pattern, strongly suggesting that Mycobacterium genotypes are distributed biogeographically. The PRA procedure was also performed with 43 reference isolates belonging to 34 species, adding a further six new patterns to the identification algorithm. A database containing the normalized restriction patterns of both enzymes was constructed. Patterns available on the Internet can be introduced into this database, which will make possible the comparison of genotypes from isolates from different parts of the world.

Rapid identification of Mycobacteria to the species level using INNO-LiPA Mycobacteria, a reverse hybridization assay.

INNO-LiPA Mycobacteria (LiPA; Innogenetics, Zwijnaarde, Belgium) is a kit for the simultaneous detection and identification of Mycobacterium species in culture and identifies the Mycobacterium tuberculosis complex, the M. avium complex (MAC), and the following Mycobacterium species: M. kansasii, M. avium, M. intracellulare, M. scrofulaceum, M. gordonae, M. xenopi, and the M. chelonae-M. abscessus complex. The assay, which targets the 16S-23S rRNA spacer region, was evaluated on 157 mycobacterial strains that had been identified by conventional techniques and PCR-restriction enzyme analysis of the hsp65 gene (PRA). Forty-seven reference strains consisting of 37 different species and 110 human clinical isolates were submitted to the test, and all were hybridized with the Mycobacterium genus probe (MYC) on the LiPA strip (100% sensitivity). Ninety-four isolates hybridized to their corresponding species- or complex-specific probes; only one isolate phenotypically identified as M. gordonae did not react with its specific probe (99.4% accuracy). Thirty-seven MAC strains were phenotypically identified to the complex level and to the species level by LiPA as M. avium (n = 18) or M. intracellulare (n = 7) or as belonging to the M. avium-M. intracellulare-M. scrofulaceum complex (n = 12). Of the last 12 strains, 10 had M. avium PRA patterns and 2 had M. intracellulare PRA patterns. Three isolates that had been identified as a single species by conventional identification were proven to be mixed cultures by the LiPA assay. The whole procedure can be performed in 1 working day, starting with the supernatant of a small amount of bacterial mass that had been treated by freezing and then boiling.

Re-evaluation of antibiotic and mercury resistance in Escherichia coli populations isolated in 1978 from Amazonian rubber tree tappers and Indians.

A study was carried out to assess the stability of antimicrobial susceptibility of wild isolates upon long-term storage using fifty-three Escherichia coli strains isolated in 1978 from feces of healthy children from the Amazon region in Brazil, exposed to low levels of antimicrobial agents, and examined for resistance to mercury and four antibiotics. All of the strains were kept in Lignières medium at room temperature and were transferred to fresh media four times during this period. Thirty-five out of the 53 strains analyzed in 1978 were viable. Upon recovery, antibiotic and mercury resistance was estimated. All of the 35 strains maintained their original phenotype in a stable fashion, except for one multiresistant strain which became susceptible to kanamycin. Fifty-four percent of the strains exhibited a resistance phenotype, among which 47% had conjugative plasmids.

Listerial meningoencephalitis: AIDS and non AIDS patients

A total of 11 patients with listeriosis wereadmited to the Hospital Emilio Ribas - Säo Paulo, Brasil. The etiology Listeria monocytogenes in 2 Aids and Listeria spp in underlying conditions was established in the other patients. The age ranged from 20 to 60 years old and white: black; male:famele ratio was 3:1 for all them. Acute meningoencephalitis in 11; renal failure in 2; acute respiratory failure, septicemia and AIDS with drug multiform exantema, respectively in 1 were observed. Leukocytosis > 500 cells/mm elevado ao cubo; glucose < 45 mg/dl; protein > 90 mg/dl and Gram-positive rod strains with positive culture to Listeria spp were revealed in the cerebrospinal fluid study. These strains were resistant to betalactamin; colistin; streptomycin and amikacin and sensitive to kanamicin; gentamicin; tetracicline; erytromicin and chloramphenicol. Monotherapy (ampicillin) or associate (ampicillin/chloramphenicol) had not influence on death or improvement during the follow-up of patients. Listeral meningoencephalitis is similar to tuberculosis or other bacterial meningitis include in cerebrospinal fluid chemistries data

[The cerebrospinal fluid in bacterial meningitis]. / Aspectos dos líquidos cefalorraquidianos nas meningites bacterianas.

Samples of 1815 cerebrospinal fluid (CSF) were studied in a meningitis outbreak during 1989 in São Paulo, Brazil. Neisseria meningitis 56% with 44% type B, Haemophilus influenzae 17%, from which 72% in children (days to 3-year-old) and Streptococcus pneumoniae 14% from which 60% in children (day to 1-year-old) of 443 (24%) of all strains. Cytochemistry study showed: purulent or turbidity aspects in 70 to 79% positive bacterioscopy or culture of CSF; white cells count > 500/mm3; glucose < 45 mg/dl; protein > 90 mg/dl in 90% of all patients. We concluded that: CSF prognostic factors: (aspect and cytochemistry) were correlated with bacterial meningitis. Bacterioscopy and positive cultures were correlated to NM, SP and HI isolation from these patients (Goodman Test).

[Health surveys from a planning perspective]. / Os inquéritos de Saúde sob a perspectiva do planejamento.

This study examines the importance of household surveys for evaluating the implementation of district-based health systems for the delivery of health services. The concepts underlying health surveys and the literature on health surveys in the Third World are reviewed, and significant methodological problems are also discussed. Although many authors dealing with this issue consider household health surveys of capital importance for the planning of health services, that was not the situation encountered by the author, who rarely found examples of the applicability of such studies. The potential use of less complex and quicker studies was a solution proposed by some authors to increase the presence of surveys in health planning. Finally, national health surveys are also analyzed.

Os Inquéritos de saúde sob a perspectiva do planejamento / Health surveys from a planning perspective

Discute a importância dos inquéritos de saúde no acompanhamento do processo de distritalizaçao do sistema de saúde. Os principais conceitos que embasam os inquéritos e a bibliografia acerca dos usos que foram feitos dos inquéritos de saúde sao revisados. A despeito dos autores dedicados a este tema afirmarem a importância dos inquéritos para o planejamento dos serviços de saúde, este trabalho encontrou evidências de que, na prática, sao muito raros os relatos de sua aplicabilidade. Os principais problemas metodológicos sao também discutidos. A proposta da realizaçao de inquéritos de demanda mais ágeis e de menor complexidade metodológica poderia ser, para alguns autores, a saída para a sua utilizaçao no planejamento em saúde

Candidíase em pacientes aidéticos / Candidiasis in AIDS patients

Trinta e cinco aidéticos entre 19 e 55 anos admitidos e tratados de candidíase no Hospital Emílio Ribas, SP, com ELISA positivo para HIV e confirmado pelo Western Blot. Tuberculose em 9 sendo 2 com pericardite; neurotoxoplasmose em 6; neurocriptococose em 5; herpes labial em 4; pneumocistose em 3 e sarcoma de kaposi em 2, achavam-se associadas. A concentraçäo inibitória mínima 50 por cento (MIC 50 por cento) para os azoles foi: ketoconazol = 2,2 µg/ml; itraconazol = 21,0 µg/ml; fluconazol = 19,0 ég/ml. O MIC 50 por cento para os polienos: nistatina = 50,0 µg/ml; anfotericina B = 0,12 µg/ml e para 5 fluorcitosina = 1,6 µg/ml nas 35 amostras de Candida isoladas. Testes näo paramétricos de Siegel revelaram significante identificaçäo (80 por cento) das Candida albicans na candidíase, e que a dose de AMB näo modificou o número de óbitos, precoce e tardio, ocorridos nesses aidéticos. O uso prévio de azoles e da nistatina explicaria, talves, o elevado MIC 50 por cento observado nas amostras de Candida isoladas

[Candidiasis in AIDS patients]. / Candidíase em pacientes aidéticos.

UNLABELLED: A total of 35 in patients admitted at Emilio Ribas Hospital--São Paulo, Brazil, with digestive candidiasis and AIDS clinical diagnostic were evaluated 10 month later, being 29 male and 6 female; white outnumbering black with age ranged from 30 to 50 years old. Agar Sabouraud culture and tube germinative tests identified 28 (80%) Candida albicans out 35 strains. Minimum inhibitory concentration (MIC) 50% was against azoles (ketoconazole = 2.2 micrograms/ml; itraconazole = 21.0 micrograms/ml and fluconazole = 19.0 micrograms/ml); polyenes (nystatin = 50.0 micrograms/ml and amphotericin B = 0.12 micrograms/ml) and 5 fluorocytosine = 1.6 micrograms/ml. Siegel tests showed significant Candida albicans proportions in strains isolated from 35 AIDS patients. There was no significant relation between AMB doses and early or late death. CONCLUSIONS: candidiasis in AIDS patients showed high MIC 50% to azoles and nystatin and significant Candida albicans proportion in all strains isolated from AIDS patients. Previous amphotericin B therapy had no influence in early or late death in 30 patients. Previous therapy possibly explained MIC 50% increases in Candida strains.