Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i) to select and characterize diazotrophs able to solubilize phosphates in vitro and (ii) evaluate the initial performance of the pineapple cultivars Imperial and Pérola in response to inoculation with selected bacteria in combination with rock phosphate. The experiments were conducted at Universidade Estadual do Norte Fluminense Darcy Ribeiro, in 2009. In the treatments with bacteria the leaf contents of N, P and K were higher than those of the controls, followed by an increase in plant growth. These results indicate that the combined application of diazotrophic phosphate-solubilizing bacteria Burkholderia together with Araxá rock phosphate can be used to improve the initial performance of pineapple slips.

Comparative studies of Yersinia pestis outer membrane isolation techniques and their potential use in plague epidemiology

In the present study three techniques for obtaining outer membrane enriched fractions from Yersinia pestis were evaluated. The techniques analysed were: differential solubilization of the cytoplasmic membrane with Sarkosyl or Triton X-100, and centrifugation in sucrose density gradients. The sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of outer membrane isolated by the different methods resulted in similar protein patterns. The measurement of NADH-dehydrogenase and succinate dehydrogenase (inner membrane enzymes) indicated that the outer membrane preparations obtained by the three methods were pure enough for analytical studies. In addition, preliminary evidences on the potential use of outer membrane proteins for the identification of geographic variants of Y. pestis wild isolates are presented.

Coccidioidomycosis in Brazil. A case report

Coccidioidomycosis is an endemic infection with a relatively limited geographic distribution: Mexico, Guatemala, Honduras, Colombia, Venezuela, Bolivia, Paraguai, Argentina and the southwest of the United States. In these countries, the endemic area is restricted to the semiarid desert like regions which are similar to the northeast of Brazil. Case report: The patient is a 32 year-old male, born in the state of Bahia (Northeast of Brazil) and has been living in São Paulo (Southeast) for 6 years. He was admitted at Hospital das Clínicas, at the Department of Pneumology in October 1996, with a 6 month history of progressive and productive cough, fever, malaise, chills, loss of weight, weakness and arthralgia in the small joints. Chest x-rays and computerized tomography disclosed an interstitial reticulonodular infiltrate with a cavity in the right upper lobe. The standard potassium hydroxide preparation of sputum and broncoalveolar lavage demonstrated the characteristic thickened wall spherules in various stages of development. Sabouraud dextrose agar, at 25° C and 30° C showed growth of white and cottony aerial micelium. The microscopic morphology disclosed branched hyphae characterized by thick walled, barrel shaped arthroconidia alternated with empty cells. The sorological studies with positive double immunodiffusion test, and also positive complement fixation test in 1/128 dilution confirmed the diagnosis. The patient has been treated with ketoconazole and presents a favorable clinical and radiological evolution

Influence of variables on centrifuge-flotation technique for recovery of Toxocara canis eggs from soil

The purpose of this study was to evaluate the influence of variables in a flotation technique for the recovery of Toxocara canis eggs from soil. The trials were done under standardized conditions on one gram of previously sterilized soil samples contaminated with 200 eggs of T. canis. The following variables were evaluated in serial steps: sieving; type of wash; time of stirring; resuspension of sediment; solution flotation. Centrifuge-flotation in sodium nitrate (d = 1.20 g/cm³) was adopted as an initial technique, using Tween 80 (0.2%) and decinormal sodium hydroxide as solutions for washing the samples. Ten tests were done to compare the variables, using counting in triplicate. The sieving of the material reduced significantly the recovery of eggs (p < 0.001) and the number of eggs recovered was higher when the sediment was resuspended (p < 0.05). After standardization, flotation solutions sodium chloride, zinc sulfate, sodium dichromate, magnesium sulfate, and sodium nitrate (d = 1.20g/cm³) were compared. The best results were obtained by using zinc sulfate solution. In conclusion, the chances of recovering T. canis eggs from samples using flotation solutions can be increased by washing of soil twice using distilled water, and resuspension of sediment. On the other hand, the sieving procedure can drastically reduce the number of eggs.

Arsenicais e inseticidas orgânicos sôbre o algodoeiro em terras roxa e arenosa

The authors carried out a series of pots and plots experiments applying arsenical and organic insecticides to cotton plants cultivated in "terra roxa" and in a sandy soil. The first results were presented in 1947, to the la. Reunião Brasileira de Ciência do Solo (First Brazilian Congress of Soil Science); they pointed out the danger resulting from the accumulation of arsenic in soils due to the constant applications of arsenicais to control cotton pests; in the course of the time, the amount of residual arsenic in the soil would determine a decrease in cotton yield caused by its toxic effect on the crop. The following conclusions were drawn from the last three experiments: 1) the field experiment conducted in a sandy soil to which lead arseniate was applied in increasing rates produced a reduction of 50 per cent in the yield (the three highest doses were responsible for this result); by this way, the pot experiment published in 1947 was confirmed); 2) in the pot experiment with "terra roxa" toxic effects appeared only in the plants receiving the last dosis of lead arsenate; this result is explained quite naturally by a considerable absorption of the AsO4 --- ion by "terra roxa" colloidal material; furthermore the CaO, P2O5 and Fe2O3 content and the pH value (higher) would decrease the arsenate solubilization in the soil considered; 3) the pot experiment with organic insecticides applied in the rates usually employed in the control of cotton pests, showed that 10% D.D.TD. and 2.5% Rotenone did not affect cotton plants cultivated in a sandy soil; however we agree with FOSTER (1951), in the point that both mineral and organic insecticides must be applied in the minimum amount as possible; we also think that experiments like those should be carried out with the known insecticides, in several soil conditions and with many crops in order to determine the maximum limits of tolerancy.

A estimação do efeito residual de fertilizantes por meio da Lei de Mitscherlich

This paper deals with the estimation of the residual effect of fertilizers through the use of Mitscherlich's law. The formulas and reasonings now presented are a further development of those introduced previously by PIMENTEL GOMES (2). The new formulas allow the estimation of the residual effect h in cases where the experiments are carried out in the same plots for two or three subsequent years (or crops). In an experiment analysed as an example, the residual effect of calcium hydroxide was estimated to be h = 0.423, that is, about 42%, so that one should advise the use of frequent application of small amounts of lime instead of heavy quantities used at long intervals.

O método potenciométrico na determinação do H+ trocável em solos

For the determination of exchangeable hydrogen ion in soils, the authors of the presente work made the extraction with normal calcium acetate solution that may have an initial pH between 7 and 8 without altering the amount of hydrogen ion extracted. The extraction was made by shaking 5,0 grams of air dry soil with 100 ml of normal calcium acetate solution, the pH of wich was ascertained to 7,0, 7,5 and 8,0 with acetic acid, in 250 mil conical flasks for 30 minutes in a Wagner shaker (30-40 rpm). The contents of the flasks were then, filtered. A 50 ml aliquot of each of the leachate was titrated with a 0,020 N NaOH solution and the volumes consumed sodium hydroxide were ploted against pH. The titration curves thus obtained showed to be straight lines between pH 8 and 9 and parallel to the curve obtained by the titration of the blank. Two ways of locating the end point of the titration showed to be possible: the use of a pHmeter or titrimeter or the use of phenolphtalein as indicator. When using a pH meter or a titrimeter, the end point may rest in any point between pH 8 and 9, and the volume of sodium hydroxide consumed is found by comparison with a similar curve obtained by the titration of the blank. When using phenolphtalein the calcium acetate solution must have a pH below 8.

Solubilidade de fosfatos naturais em solução de ácido cítrico a 2%: modificação nas condições de agitação

This paper deals with a modification in the solubilization technique of natural phophates in the 2% citric acid solution. The proposed technique is as follows: 2,5 g of phosphatic material and 250 ml of 2% citric acid solution, in a 500 ml Erlenmeyer flask, are shaken for 30 minutes at 30-40 rpm. The phosphorus (P2O5) was determined by the usual method. The data obtained were compared with the conventional technique in which a Stohmann bottle is used. The natural phosphates used were: Phosphorita de Olinda (Pernambuco), Flórida Phosphate (USA) and Hiperphosphate (África). Statistical analysis was applied to the data and the following conclusions were arrived at: a) The precision is equivalent in both techniques. b) There is no significant variation between the means obtained with the two technique.

Emprêgo do teste químico para o estudo da eliminação das gonadotropinas durante o ciclo menstrual

A chemical test previously described for the diagnosis of pregnancy was applied to the study of the excretion of gonadotropin in the urine during menstrual cycle. The chemical test is based on the selective adsorption by kaolim of the reducing substances biologically related to urinary gonadotropin. The active substance when acidified to pH 4.0 is adsorbed by the kolin and eluated with O.1N sodium hydroxide. The alkaline solution is treated by Somogyi's copper reagent and the excess not reduced is titrated by 0.005 N sodium thiosulfate. Gonadotropin is quantitatively addorbed by kaolin at pH 4.0 and eluated by alkaline solution as previously demonstrated by the A. (1). In the present paper the complete menstrual cycle was studied daily. It was observed that normally there are two distinct maxima of excretion. This study is based on 11 normal cycles (24-30 days) and 34 abnormal ones. Normal cycles showed a intramenstrual estrogens elimination from 200 to 260 mice units determinated by the Allen - Doisy full estrus smear test. The abnormal cycles belonging also to normal women showed much less estrogen excretion (14 to 25 mice units) Table II). In those cases with decreased estrogen excretion no fall in the curve after 14 th. day was observed. The A. suggest that the peaks of gonadotropin excretion is not related to the oculation but possibly due, the first one, to the follicle stimulating hormone and the second to the luteinizing hormone of hormone stimulating of the inerstitial tissue.

Culturas de bacilos ácido-álcool resistentes isolados de hematófagos infectados em leprosos: evidências de se tratar do bacilo de Hansen

The A. summarises the history of his first culture of acidfast bacillus isolated directly from leprosy lesions (Sample José) and refers about two samples recovered from guinea pig and white rat inoculated with said culture. Then the A. completes his previous descriptions of four cultures of acidfast bacilli isolated by him from ticks (Amblyomma cajaennense and Boophilus microplus, two cultures from each species) infected experimentally in lepers. The A. having found specimens of two species of Triatomidae (Triatoma infestans and Panstrongylus megistus) naturally infected with HANSEN bacillus in huts habited by lepers in the State of Minas Gerais (Dec. 1942), started a series of experiments, using larvae and nymphs of T. infestans bred in laboratory at the Instituto Oswaldo Cruz, to infect in active cases of leprosy, in the city of Rio de Janeiro, could obtain two new samples of cultures of acid-fast bacilli (Ns. 6 and 7 of his set). In this papaer the A. studies the biological properties of said cultures, proving that Penicilin has not effect upon them, like other substances. The sulphuric and acetic acids were used to purify some of the cultures, with good results, the cultures becoming more rich and growing faster. Potassium hydroxide Sodium (10% solution) was also used with success to isolate and to purify the cultures, but it seems that it affects the bacilli in some way. In flud glycerinated media the majority of such cultures produce velum suitable for the preparation of antigens for skin tests and for therapeutical use. At last the A. says that he is becoming convinced that the HANSEN bacillus is in cause, especially after thee evidences of culturing the bacillus from one patient, in different opportunities.

Estudos sobre a atividade dos extratos da suprarenal

Studies have been carried out on the method of Britton and Silvette modified by Reinecke and Kendall, for the evaluation of cortico-adrenal extracts, based on the deposition of glycogen in the liver of adrenaletomized rats. The test was performed in a total of 180 normal and adrenalectomized rats. The extracts tested were: a) an aqueous extract of cortico-adrenal cortex prepared by the Swingle and Pfiffner technique; b) the same extract added with ascorbic acid (Supracortin Labor); c) desoxycorticosterone acetate (Percortol Ciba and Syncortyl Roussell). Male rats were used, ranging from 40-200g, fed since the 18 th days old with a special diet, in which they were maintained until the day before the injection. Adrenalectomy was performed under urethane anesthesia. The fourth day after operation, food was removed and they were fasted for 24 hours. In the morning of the fifth day, injections of the material to be assayed were given at hourly and two hours intervals, during four to eight hours. One or two hours after the last injection, the animals were sacrified, the livers removed and dropped into a hot 30% solution of potassium hydroxide, and worked by Good, Kramer and Somogyi method. The glycogen was calculated as milligrams per lOOg of body and liver weight. The results obtained are shown in the tables I, II, and III. When several dosages of the same sample of extract were made (5 animals each dose), the amount of glycogen deposited in the liver per lOOg of body and liver weight, was found to be a positive function of the dose injected. The graph 2, shows these results. The synthetic compounds were ineffective. Our results are in agreement with those of Reinecke and Kendall and of Olson et al.

Schistosoma mansoni antigenic extracts obtained by different extraction procedures

Solubilization of Schistosoma mansoni antigens was obtained by agitation of adult worms in a 3M KCl solution. The protein contents of the KCl extrats varied from 0.35 to 0.96 mg/ml. Sera from 97 patients with hepatointestinal shistosomiasis and viable eggs in stools from a Brazilian endemic area were studied by immunoelectroomophoresis and Ouchterlony immunodiffusion methods with the KCl extract and with another antigen, obtained by homogenization of adult schistosomes in saline. The rate of positiveness of immunoprecipitation deterctions by immunoelectroomophoresis with the KCl extract was 53.5%. A correlation was verified between methods of detection and extration procedures, resulting in a better association of the extract obtained by agitation in 3M KCl and immunoelectroomophoresis.

Biochemical, immunological and toxicological characteristics of the crystal proteins of Bacillus thuringiensis subsp. medellin

Characterization of the insecticidal and hemolytic activity of solubilized crystal proteins of Bacillus thuringiensis (Bt) subsp. medellin (Btmed) was performed and compared to solubilized crystal proteins of isolates 1884 of B. thuringiensis subsp. israelensis (Bti) and isolate PG-14 of B. thuringiensis subsp. morrisoni (Btm). In general, at acid pH values solubilization of the Bt crystalline parasporal inclusions (CPI) was lower than at alkaline pH. The larvicidal activity demonstrated by the CPI of Btmed indicated that optimal solubilization of CPI takes place at a pH value of 11.3, in Bti at pH values from 5.03 to 11.3 and in Btm at pH values from 9.05 to 11.3. Hemolytic activity against sheep red blood cells was mainly found following extraction at pH 11.3 in all Bt strains tested. Polyacrylamide gel electrophoresis under denaturing conditions revealed that optimal solubilization of the CPI in all Bt strains takes place at the alkaline pH values from 9.05 to 11.3. An enriched preparation of Btmed crystals was obtained, solubilized and crystal proteins were separated on a size exclusion column (Sephacryl S-200). Three main protein peaks were observed on the chromatogram. The first peak had two main proteins that migrate between 90 to 100 kDa. These proteins are apparently not common to other Bt strains isolated to date. The second and third peaks obtained from the size exclusion column yielded polypeptides of 68 and 28-30 kDa, respectively. Each peak independently, showed toxicity against 1st instar Culex quinquefasciatus larvae. Interestingly, combinations of the fractions corresponding to the 68 and 30 kDa protein showed an increased toxicity. These results suggest that the 94 kDa protein is an important component of the Btmed toxins with the highest potency to kill mosquito larvae. When crystal proteins of Bti were probed with antisera raised independently against the three main protein fractions of Btmed, the only crystal protein that showed cross reaction was the 28 kDa protein. These data suggest that Btmed could be an alternative bacterium for mosquito control programs in case mosquito larval resistance emerges to Bti toxic proteins.

First characterization of Candida albicans by random amplified polymorphic DNA method in Nicaragua and comparison of the diagnosis methods for vaginal candidiasis in Nicaraguan women

A total of 106 women with vaginitis in Nicaragua were studied. The positive rate for the identification of Candida species was 41% (44 positive cultures out of 106 women with vaginitis). The sensitivity of microscopic examination of wet mount with the potassium hydroxide (KOH) was 61% and 70% with Gram's stain when using the culture of vaginal fluid as gold standard for diagnosis of candidiasis. Among the 44 positives cultures, isolated species of yeast from vaginal swabs were C. albicans (59%), C. tropicalis (23%), C. glabrata (14%) and C. krusei (4%). This study reports the first characterization of 26 C. albicans stocks from Nicaragua by the random amplified polymorphic DNA method. The genetic analysis in this small C. albicans population showed the existence of linkage disequilibrium, which is consistent with the hypothesis that C. albicans undergoes a clonal propagation.

Humoral immune responses induced by Kudoa sp. (Myxosporea: Multivalvulida) antigens in BALB/c mice

The majority of Kudoa species infect the somatic muscle of fish establishing cysts. As there is no effective method to detect infected fish without destroying them these parasited fish reach the consumer. This work was developed to determine whether this parasite contains antigenic compounds capable of provoking an immune response in laboratory animals, in order to consider the possible immunopathological effects in man by the ingestion of Kudoa infected fish. BALB/c mice were injected by the subcutaneous route with the following extracts suspended in aluminium hydroxide: group 1 (black Kudoa sp. pseudocyst extract), group 2 (white Kudoa sp. pseudocyst extract), and group 3 (non-infected hake meat extract). Specific antibody levels were measured by ELISA against homologous and heterologous antigens. The highest responses were obtained from the black Kudoa sp. pseudocyst extract (group 1).The low optic density levels detected in group 3 proved that the results obtained in groups 1 and 2 were a consequence of the parasitic extract injection. The IgG1 was the predominant subclass. IgE detected in groups 1 and 2 showed the possible allergenic nature of some of the components of the parasitic extract. High IgA levels and medium IgG2a and IgG3 levels were obtained in groups 1 and 2. Low IgG2b responses were shown. No cross-reactions between Kudoa sp. pseudocyst extracts and the non-infected hake meat extract were observed.