An attempt to control schistosomiasis mansoni in an endemic area by the use of Hycanthone as chemotherapeutic agent

Hycanthone in a single dose of 3.3 mg/kg of body weight was used to treal mansoni schistosomiasis in 597 persons (83%) of the population of the endemic vilage of Canabrava. Ninety two patients received a 2nd course 14 months later. There was one death em the 2nd treatment. The cure rate after one stool examination was smaller after the 2ni treatment in comparison with the first one. Re-infections did not occur imediately after the treatment. Three years later the prevalence of persons passing eggs through one stool examination was 19% compared to the 46.3% before the treatment. Adults are more resistant to the re-infections than younger.

Comparative study of cultivation of feces in vermiculite or charcoal to obtain larvae of Strongyloides venezuelensis

IntroductionWe compared feces culturing in charcoal or vermiculite to obtain Strongyloides venezuelensis larvae.MethodsFeces (5g) from infected rats was mixed with vermiculite (10g) or coal (10g) in plastic cups and incubated at 28°C for 48h. Larvae were recovered using Baermann-Moraes method.ResultsSignificantly higher number of positive larval cultures were recovered from vermiculite than from charcoal (15/17 and 4/17, respectively; p < 0.001; 990.6 ± 307.5 and 215 ± 78.1 larvae, p = 0.027).ConclusionsVermiculite yields more larvae and provides cleaner pellets, improving larvae identification and facilitating their use for other purposes.

An attempt to control Phlebotomine sand flies (Diptera: Psychodidae) by residual spraying with deltamethrin in a Colombian village

An attempt was made to control phlebotomine sand flies biting indoors in a rural community near Cali, Colombia, using the residual insecticide "K-Othrine" (deltamethrin) sprayed on the inside walls of houses. Twelve houses were divided into matched pairs based on physical characteristics, one house in each pair being left untreated while the inside walls of the other were sprayed with 1 deltamethrin at a concentration of 500 mg a.i./m2. Sand flies were sampled each week using protected human bait and sticky trap collections for four months after spraying. The number of sand flies (Lutzomyia youngi) collected on sticky traps was significantly lower (P = 0.004) in the untreated houses than in the treated ones with which they were matched. This difference was not significant for L. columbiana; the other anthropophilic species were not present in large numbers. The numbers collected on human bait in treated and untreated houses were not significantly different for either species. Activity of the insecticide as determined by contact bioassays remained high throughout the study and failure to control the insects was attributed to two factors: the tendency of sand flies to bite before making contact with the insecticide and the fact that the number of sand flies that entered houses represented a relatively small proportion of the population in the wooded areas surrounding the settlement in the study.

A new experimental procedure to obtain titania powders as anatase phase by a sol-gel process

Titania powders were synthesized by a sol-gel process using titanium tetrabutoxide as precursor. The syntheses were performed in water or in solutions of dimethylformamide (dmf) or dimethylsulfoxide (dmso). It is demonstrated, by X-ray diffraction patterns of the synthesized powders, that the samples obtained in dmf or dmso solutions are crystalline (anatase phase) with some minor amount of brookite phase, whereas the sample synthesized in water is amorphous. The anatase phase can be obtained independently of any previous or further treatment of the synthesized powder, such as hydrothermal or heat treatment, providing a new, simple, quick and inexpensive route to synthesize anatase powders. From the peak broadening of the anatase (101) diffraction, the crystallite sizes were calculated as 6 nm.

Combined experimental powder X-ray diffraction and DFT data to obtain the lowest energy molecular conformation of friedelin

Friedelin molecular conformers were obtained by Density Functional Theory (DFT) and by ab initio structure determination from powder X-ray diffraction. Their conformers with the five rings in chair-chair-chair-boat-boat, and with all rings in chair, are energy degenerated in gas-phase according to DFT results. The powder diffraction data reveals that rings A, B and C of friedelin are in chair, and rings D and E in boat-boat, conformation. The high correlation values among powder diffraction data, DFT and reported single-crystal data indicate that the use of conventional X-ray diffractometer can be applied in routine laboratory analysis in the absence of a single-crystal diffractometer.

Improved method to obtain pfaffic acid as a marker for quality control

Pfaffic acid, a marker of Hebanthe eriantha (Brazilian ginseng), was first isolated in 1983 but is not yet commercially available. This lack of availability compromises the quality control of this plant and its derivatives. This paper proposes a process for pfaffic acid isolation from roots of H. eriantha at a purity suitable for analytical purposes. The steps involved in this process included extraction, hydrolysis, fractionation and purification by preparative HPLC. This process led to isolation of pfaffic acid with a chromatographic purity of 98.5% in a 0.25% yield from dried roots of H. eriantha; this yield is more than forty times higher than that of the current method in the literature.

Evaluation of protein extraction methods to obtain protein concentrate from cassava leaf

The cassava leaf, waste generated in the harvest of the roots, is characterized by high content of protein, vitamins and minerals; however, its use is limited due to the high fiber content and antinutritional substances, which can be removed by obtaining protein concentrates. In this context, the objective of this study was to evaluate protein extraction processes, aiming the use of cassava leaves (Manihot esculenta Crantz) as an alternative protein. Four methods were tested: 1) Coagulation of Proteins by Lowering the Temperature, 2) Extraction by Isoelectric Precipitation, 3) Solubilization of Proteins and 4) Fermentation of Filter Leaf Juice. To obtain the concentrates, the use of fresh or dried leaves and extraction in one or two steps were also evaluated. The solubilization of proteins (method 3) showed a higher extraction yield; however, with concentrate of low quality. The fermentation of the juice (method 4) produced concentrates with higher quality and lower costs and the isoelectric precipitation (method 2) promoted the obtention of concentrates in less time, both with good prospects for use. The use of two extraction steps was not advantageous to the process and there was no difference between the use of fresh or dried leaf, and the use of fresh leaves is presented as a good option for the simplicity of the method.

Method to obtain platelet-rich plasma from rabbits (Oryctolagus cuniculus )

Abstract: Platelet-rich plasma (PRP) is a product easy and inxpesnsive, and stands out to for its growth factors in tissue repair. To obtain PRP, centrifugation of whole blood is made with specific time and gravitational forces. Thus, the present work aimed to study a method of double centrifugation to obtain PRP in order to evaluate the effective increase of platelet concentration in the final product, the preparation of PRP gel, and to optimize preparation time of the final sample. Fifteen female White New Zealand rabbits underwent blood sampling for the preparation of PRP. Samples were separated in two sterile tubes containing sodium citrate. Tubes were submitted to the double centrifugation protocol, with lid closed and 1600 revolutions per minute (rpm) for 10 minutes, resulting in the separation of red blood cells, plasma with platelets and leucocytes. After were opened and plasma was pipetted and transferred into another sterile tube. Plasma was centrifuged again at 2000rpm for 10 minutes; as a result it was split into two parts: on the top, consisting of platelet-poor plasma (PPP) and at the bottom of the platelet button. Part of the PPP was discarded so that only 1ml remained in the tube along with the platelet button. This material was gently agitated to promote platelets resuspension and activated when added 0.3ml of calcium gluconate, resulting in PRP gel. Double centrifugation protocol was able to make platelet concentration 3 times higher in relation to the initial blood sample. The volume of calcium gluconate used for platelet activation was 0.3ml, and was sufficient to coagulate the sample. Coagulation time ranged from 8 to 20 minutes, with an average of 17.6 minutes. Therefore, time of blood centrifugation until to obtain PRP gel took only 40 minutes. It was concluded that PRP was successfully obtained by double centrifugation protocol, which is able to increase the platelet concentration in the sample compared with whole blood, allowing its use in surgical procedures. Furthermore, the preparation time is appropriate to obtain PRP in just 40 minutes, and calcium gluconate is able to promote the activation of platelets.

Optimization of the RNeasy Mini Kit to obtain high-quality total RNA from sessile cells of Staphylococcus aureus

Biofilm formed by Staphylococcus aureus is considered an important virulence trait in the pathogenesis of infections associated with implantable medical devices. Gene expression analyses are important strategies for determining the mechanisms involved in production and regulation of biofilm. Obtaining intact RNA preparations is the first and most critical step for these studies. In this article, we describe an optimized protocol for obtaining total RNA from sessile cells of S. aureus using the RNeasy Mini Kit. This method essentially consists of a few steps, as follows: 1) addition of acetone-ethanol to sessile cells, 2) lysis with lysostaphin at 37°C/10 min, 3) vigorous mixing, 4) three cycles of freezing and thawing, and 5) purification of the lysate in the RNeasy column. This simple pre-kit procedure yields high-quality total RNA from planktonic and sessile cells of S. aureus.

β-carotene biotransformation to obtain aroma compounds

Carotenoids are important constituents of food due to their color and because their degradation products generate important volatile compounds in foods. Aroma compounds derived from carotenoids are widely distributed in nature, and they are precursors of many important aromas in foods such as fruits and in flowers as well. They present high aromatic potential and are therefore of great interest to the industries of aromas and fragrances. In this study, more than 300 previously isolated microorganisms with potential for biotransformation of β-carotene present in the culture medium were selected using the plate method; about 80 strains presented capacity to produce aroma compounds and 7 strains were selected by an untrained panel of tasters to generate aroma compounds. The β-ionone was the main compound produced by CS1 (34.0 mg.L-1) and CF9 (42.4 mg.L-1) microorganisms at 72 and 24 hours of fermentation, cultured with and without pre-inoculation, respectively. The β-damascone and pseudoionone were found in low concentrations, 1,1,6-trimethyl-1,2,3,4-tetrahydronaphthalen (TTN) was tentatively identified and other compounds such as apocarotenoids, apparently obtained from the cleavage of the central part of the carotenoid, were detected.

Comparison between freeze and spray drying to obtain powder Rubrivivax gelatinosus biomass

The use of colorants in products of animal origin is justified by the improvement in the color of foods since this attribute is considered a quality criterion. These additives can be produced using industrial effluents as substrates and appropriate organisms, such as Rubrivivax gelatinosus. Oxycarotenoids represent a class of carotenes responsible for the pigmentation of animals and vegetables. R. gelatinosus grows in fish industry effluent with the resulting production of a bacterial biomass containing oxycarotenoids. The purpose of this study was to compare the use of two drying processes - spray and freeze drying - to obtain powder biomass in terms of the process parameters (yield, productivity, and product recovery) and the product characteristics (color, proximate composition, and oxycarotenoids). No difference was detected in the yield between these techniques, while productivity was higher using spray drying. Higher product recovery and moisture were achieved with freeze drying, while ash was higher with spray drying. The freeze dried biomass was redder, darker and less saturated than the spray dried biomass. No difference in oxycarotenoids was detected between the biomasses. Although it results in lower recovery rate, spray drying was faster and more productive, and it provided the same yield as freeze drying, which makes it the method of choice for obtaining R. gelatinosus biomass.

Spirulina platensis: process optimization to obtain biomass

Spirulina platensis is a photoautotrophic mesophilic cyanobacterium. Its main sources of nutrients are nitrate, urea, and ammonium salts. Spirulina cultivation requires temperature, light intensity, and nutrient content control. This microalgae has been studied and used commercially due to its therapeutic and antioxidant potential. In addition, several studies have reported its ability to use CO2, its immune activity, and use as an adjuvant nutritive factor in the treatment of obesity. The objective of this study is the production of biomass of S. platensis using different rates of stirring, nitrogen source, amount of micronutrients, and luminosity. A 2(4) experimental design with the following factors: stirring (120 and 140 RPM), amount of nitrogen (1.5 and 2.5 g/L), amount of micronutrients (0,25 and 0,75 mL/L) (11 and 15 W), and luminosity was used. Fermentation was performed in a 500 mL conical flask with 250 mL of culture medium and 10% inoculum in an incubator with controlled stirring and luminosity. Fermentation was monitored using a spectrophotometer (560 nm), and each fermentation lasted 15 days. Of the parameters studied, luminosity is the one with the highest significance, followed by the amount of nitrogen and the interaction between stirring and micronutrients. Maximum production of biomass for 15 days was 2.70 g/L under the following conditions: luminosity15W; stirring, 120 RPM; source of nitrogen, 1.5 g/L; and micronutrients, 0.75 mL/L.

Seropositivity for anti-Trypanosoma cruzi antibodies among blood donors of the "Hospital Universitário Regional do Norte do Paraná", Londrina, Brazil

The most frequent form of acquisition of Chagas' disease in endemic areas was the transmission through the feces of contaminated triatominae. However, special attention should be paid in urban areas to transmission by blood transfusion, justifying the compulsory screening of blood donors. Early investigations at blood banks in the town of Londrina, Brazil, demonstrated that the seroprevalence of anti-Trypanosoma cruzi antibodies among blood donors was approximately 7.0% in the fifties9,34. Further studies demonstrated pratically the same seroprevalence until the eighties4,32,41. In an attempt to obtain data about the real dimension of the seropositivity for anti-Trypasonoma cruzi antibodies in the region, the authors carried out a large-scale study on 45,774 serum samples from blood donors of the Hemocentro of Hospital Universitário Regional do Norte do Paraná (HURNP), Universidade Estadual de Londrina. The immunological tests were done at the Division of Clinical Immunology of HURNP from May 1990 to December 1994. The serum samples were studied by the indirect hemagglutination assay (IHA, using kits commercially obtained from EBRAM) and by indirect immunofluorescence (IFI, using kits from LIO SERUM) with anti-human IgG conjugate (LABORCLIN). The results demonstrated that 643 serum samples were positive in both assay corresponding to a seroprevalence of 1.4%, i.e., a significant decrease in anti-Trypanosoma cruzi antibodies in the region in comparison with the previously mentioned rates. Data correlating sex and age of seropositive blood donors are presented, as well as the possible factors that may have contributed to the results observed.

Resolvendo a equação de Schrödinger utilizando procedimentos numéricos fundamentais

A combination of the variational principle, expectation value and Quantum Monte Carlo method is used to solve the Schrödinger equation for some simple systems. The results are accurate and the simplicity of this version of the Variational Quantum Monte Carlo method provides a powerful tool to teach alternative procedures and fundamental concepts in quantum chemistry courses. Some numerical procedures are described in order to control accuracy and computational efficiency. The method was applied to the ground state energies and a first attempt to obtain excited states is described.