Acidophilic macrophage pneumonia in laboratory mice

Acidophilic macrophage pneumonia, characterized by an accumulation of characteristic crystalloid-laden alveolar macrophages, was seen in 30/7,500 NMRI, 7/600 T x HT, 2/100 C57BL and in no cases of 1,500 CBA and 1,100 BALB/c mice. Histologically, there was a focal accumulation of large numbers of eosinophilic macrophages, generally associated with granulocytes. Macrophages could be mononucleate or multinucleate and had a crystalline cytoplasm. Free-lying crystals were sometimes observed. Ultrastructurally, macrophages had a cytoplasmic accumulation of needle-shaped and rhomboidal crystals, often showing a clear lattice structure with a repeat of 3-5 nm. The crystalloid inclusions may be derived from the breakdown products of granulocytes and appear similar to inclusions in macrophages in other parts of the hematopoietic system. That these inclusions are probably derived from eosinophils is based on the appearance within macrophages of structures resembling eosinophil granules at various stages of degradation and the similarity between the lattice repeat of the crystalloids and that of the crystalline core of the eosinophil granule. The crystalloid inclusions may be related to the Charcot-Leyden crystals found in human beings.     

Endophytic bacteria from selenium-supplemented wheat plants could be useful for plant-growth promotion,biofortification and Gaeumannomyces graminis biocontrol in wheat production

In this study, we isolated putative plant-growth-promoting endophytic bacteria from selenium-supplemented wheat grown under field conditions. These bacterial strains belonged to Bacillus, Paenibacillus, Klebsiella, and Acinetobacter genera and showed genetic similarly with rhizospheric bacteria isolated in the same Andisol soil and with other endophytic strains previously reported. Strains isolated from selenium-supplemented wheat were highly tolerant to elevated selenium concentration (ranged from 60 to 180 mM), and showed potential plant-growth-promoting capabilities (auxin and siderophore production, phytate mineralization, and tricalcium phosphate solubilization). In addition, some strains like Acinetobacter sp. (strain E6.2), Bacillus sp. (strain E8.1), Bacillus sp., and Klebsiella sp. (strains E5 and E1) inhibited the growth of Gaeumannomyces graminis mycelia in vitro at 100, 50, and 30 %, respectively. These endophytic microorganisms would be useful for dual purposes: selenium biofortification of wheat plants and control of G. graminis, the principal soil-borne pathogen in volcanic soils from southern Chile.     

Reproductive phenology ofStenocereus gummosus (Engelm.) Gibson & Horak. Implications for its cultivation

Summary Stenocereus gummosus (“pitaya agria”, Cactaceae) is a wild native species of the Baja California Peninsula, Mexico. The fruit of these plants is harvested by ranchers for public consumption. There has been no attempt to cultivate this species or to enhance fruit production by selecting highly productive lines with desirable characteristics. Nevertheless, it is relatively easy to propagate asexually. Seed propagation is not practical in spite of its regular flower, fruit, and viable seed generation. Here, the “pitaya agria” was studied over 4 years (1988–1991) to generate basic information that may be useful for its induction to cultivation. A sample of plants was monitored during phenological events of budding, flowering, fruiting, and abortion. Among the results, we found that a third of the original buds developed into fruit, and the first 40 cm of the branches yielded more buds where the conversion into fruit was higher than in the rest of the branch. A statistical analysis revealed slight differences in the phenological events, despite dissimilar rainfall over the four years. In view of its successful asexual propagation, this species can be considered commercially promising.     

Selenobacteria selected from the rhizosphere as a potential tool for Se biofortification of wheat crops

Cereal production in southern Chile is based on ash-derived volcanic Andisols, which present suboptimal levels of available selenium (Se). Strategies are needed to improve Se content in cereal crops and concomitantly improve the nutritional quality of grain. Here, we investigated the occurrence of Se-tolerant bacteria (STB) in Andisols and evaluated Se tolerance and accumulation in STB. The inoculation of wheat with STB and the contributions of these bacteria to Se content in plants were also evaluated under greenhouse conditions. The results showed that Se amendment of Andisols stimulated some bacterial groups (Paenibacillaceae and Brucellaceae) but inhibited others (Clostridia, Burkholderiales, Chitinophagaceae and Oxalobacteraceae), as revealed by denaturing gradient gel electrophoresis. Furthermore, we found four STB isolates that displayed 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase activity) and that carried the acdS gene as revealed by PCR. The selected STB were characterised as Stenotrophomonas, Bacillus, Enterobacter and Pseudomonas according to partial sequencing of the 16S rRNA gene. After 24 h of culture in nutrient broth, the selected STB showed the ability to grow in high Se concentrations (5 and 10 mM) and to accumulate elemental Se in micro- and nanospherical deposits, transforming 50–80 % of the Se initially added. Greenhouse experiments with wheat showed that Se associated with STB (micro- and nanospheres of elemental Se and other intracellular forms) can be translocated into leaves of wheat plantlets.     

Formation and decay of ethylenethiourea (ETU) in soil and water under tropical conditions

Mancozeb is a fungicide frequently used in tropical countries. It rapidly decomposes into ethylenethiourea (ETU), a more stable and toxic metabolite than mancozeb that is, therefore, regarded as a pollutant of concern. The objective was to study ETU formation and decay kinetics in soil and water under tropical conditions in order to assess its potential for accumulation. Batch experiments, spiked with either mancozeb or ETU, were carried out under natural (= active) as well as tyndallized conditions. In active soils, dissipation of ETU occurred significantly faster (half‐life 1.5 h) than in tyndallized soils (half‐life time 28 h). In water under natural and sterile conditions, decay was slower than in soils with an ETU half‐life time of 115 and 99 h, respectively. Microbial activity was seen to play an important role in ETU dissipation in soil. However, in water nonbiological processes seem to be more important in the breakdown of the molecule, with hydrolysis being the most probable decay mechanism. Decay of both mancozeb and ETU was found to occur more rapidly than previously reported. The high humidity and temperatures under the simulated humid tropical conditions, and higher microbial activity, lead to more rapid decay of these molecules than under other conditions. Nevertheless, a concentration of 1.29 mg ETU L^–1 was still observed 8 d after adding mancozeb (20.83 mg L^–1) to water under humid tropical conditions. These results suggest that, in comparable regions in the humid tropics, it is unlikely that ETU would accumulate in soil but it represents a potential risk for accumulation in water bodies.     

Application of the Weng’s ratio for the identification of Zn, Cu, and Pb contamination in soils and sediments

Purpose

This work explores the application of the use of Zn, Cu, and Pb relative contents as a new type of normalization method for geochemical properties of soils and sediments in an Atlantic Basin (Anllóns River, NW Spain). The method is based on the conservative behavior of these elements, which exhibit a certain concentration ratio that remains stable as long as there are no human disturbances.

Materials and methods

The average relative contents of Zn, Cu, and Pb were calculated by dividing the concentration of each metal in soils or sediments, in the <63-μm fraction, by the sum of Zn, Cu, and Pb, expressed as a percentage. The evaluation of the sum of the average relative concentrations of Zn, Cu, and Pb (Ri), together with three standard deviations for each element, namely, Ri ± 3Si, allows a hexagon to be constructed, represented in ternary diagrams of Zn:Cu:Pb. Following the method proposed by Weng et al. (Environ Geol 45:79–85, 2003), those samples falling outside the hexagon must be considered outliers.

Results and discussion

Results obtained confimed the conservative behavior between the relative contents of Zn, Cu, and Pb in surficial samples (soils, bed, and suspended sediments). Only sediment cores displayed nonconservative behavior, showing a marked Pb enrichment, with respect to the surficial samples. When Zn, Cu, and Pb relative contents were plotted in ternary diagrams, outliers were best classified when the hexagon was drawn with standard deviations of samples from the study area. The hexagon drawn with an international database of soils and sediments showed a poorer classification of outliers.

Conclusions

The results showed that total Zn, Cu, and Pb relative contents may be employed to investigate anthropogenic disturbances of these elements in soils and sediments of the Anllóns River Basin, thus corroborating that this type of normalization may be employed as a tool to assess outliers in a contaminated area.     

An initial study on soil wettability effects during entrapped LNAPL removal by surfactant flooding in coarse-grained sand media

Purpose

Non-ideal or fractional wettability conditions may exist at field sites. It was hypothesized that fractional wettability could cause larger entrapped LNAPL saturations and unexpected soil interactions during surfactant remediation. Soil wettability effects during entrapped LNAPL recovery by surfactant flooding in coarse-grained sand were investigated through a comparative study. The main objective was to identify the impacts of soil wettability on LNAPL removal via submicellar concentration surfactant flooding to remobilize entrapped LNAPL.

Materials and methods

A baseline for comparison was established by testing an ideal water-wet soil (silica sand) along with a fractionally wet soil. Two LNAPLs were tested: LNAPL from a contaminated field site and heptane, which represented an ideal lab-grade fluid. Contact angle, interfacial tension, capillary pressure–saturation, and column tests were performed to characterize wettability and identify the effects of soil wettability during entrapped LNAPL recovery. Two anionic surfactants were used for the column experiments: sodium dodecyl-benzene-sulfonate and a field site anionic surfactant. To further investigate the effects of LNAPL contact time within the soil, columns tests were performed at two different LNAPL contact times.

Results and discussion

Contact angle measurements and column tests conducted with the field LNAPL revealed its potential to establish non water-wet wettability conditions. Column test results indicated that fluid entrapment was independent of fluid type, and the wettability and contact time conditions studied. Entrapped LNAPL saturations after water flooding were approximately 19 %. Entrapped LNAPL removal by mobilization occurred at the predetermined submicellar surfactant concentration (0.5 g/L) with a maximum removal of 43 %. Entrapped LNAPL removal from fractionally wet columns was higher in comparison to water-wet columns and was found to increase with contact time.

Conclusions

Entrapped LNAPL saturations after water imbibition were not impacted by the wettability conditions studied. The fractionally wet soil behaved differently during the surfactant-flood; higher LNAPL removal was achieved suggesting that non-ideal wettability had a positive impact. The presence of NAPL-wet mineral grains might have favored pore scale interactions causing NAPL redistribution and increasing NAPL-surfactant solution interfacial areas contributing to LNAPL removal. Pore scale studies and subsequent testing is recommended to further this study’s findings.     

Photosynthetic performance of Hevea brasiliensis affected by South American Leaf Blight under field conditions

South American Leaf Blight (SALB), caused by the fungus Pseudocercospora ulei, is the principal rubber crop disease in Latin America. Several studies have focused on the genetics of resistance and the epidemiology of this disease, but few have analyzed the physiological alterations caused by SALB in Hevea brasiliensis. In addition, changes under field conditions are poorly understood. The present study aimed to analyze changes in gas exchange and chlorophyll a fluorescence traits in leaflets with different leaf stages and SALB severity levels from two H. brasiliensis clones with distinct susceptibility to disease in juvenile plants grown under field conditions (clonal garden). The photosynthetic performance was strongly limited in the high susceptibility clone (FX 3864), mainly in the young leaflets with maximum SALB severity (‘3’ and ‘4’), as compared to the low susceptibility clone (FX 4098). The principal alterations included a reduction in the photosynthetic rate (>?79%), stomatal conductance (>?85%), extrinsic water use efficiency (>?85%), and ability to capture, use and dissipate light energy in photosystem II, as compared to healthy leaflets. The damage was less intense in mature leaflets from both rubber tree clones. The favorable performance observed in clone FX 4098 means it is a potential candidate for commercial scale use under non-SALB escape conditions in the Amazon region.

     

Effect of the Heavy Metals Cu,Ni, Cd and Zn on the Growth and Reproduction of Epigeic Earthworms (E. fetida) during the Vermistabilization of Municipal Sewage Sludge

In order to enhance the removal of heavy metals such as Ni, Cu, Zn and Cd from wastewater, different cow dung/sewage sludge ratios were tested to assess the effect of these metals on the adaptability of Eisenia fetida earthworms to the treatment process carried out in a typical plant located in Tamaulipas, Mexico. Two experimental water treatment setups were proposed. The first set of experiments was planned to determine the adequate sewage sludge/cow dung ratio(s), whereas the second arrangement was designed to evaluate the growth performance and fecundity of the earthworms under high heavy metal concentrations. To achieve the objectives, the experiments were conducted for 90 days under controlled environmental conditions. Maximum worm biomass and growth rates were attained in samples containing 25 wt.% of sewage sludge. Weight and mortality of worms were significantly affected by the high levels of heavy metals, making difficult the metal accumulation in the worm tissues.     

Antimutagenic Properties of Mangifera indica L. Stem Bark Extract and Evaluation of its Effects on Hepatic CYP1A1

Mangifera indica stem bark extract (MSBE) is a Cuban natural product which has shown strong antioxidant properties. In this work, the antimutagenic effect of MSBE was tested against 10 well-known mutagens/carcinogens in the Ames test in the absence or presence of metabolic fraction (S9). The chemical mutagens tested included: cyclophosphamide, mitomycin C, bleomycin, cisplatin, dimethylnitrosamine (DMNA), benzo[a]pyrene (BP), 2-acetylaminofluorene (2-AAF), sodium azide, 1-nitropyrene (1-NP) and picrolonic acid. Protective effects of the extract were also evaluated by comparing the efficiency of S9 fraction obtained from rats treated during 28?days with oral doses of MSBE (50?C500?mg/kg) with that obtained from rats treated with vehicle (control) to activate bleomycin and cyclophosphamide in the Ames test. MSBE concentrations between 50 and 500???g/plate significantly reduced the mutagenicity mediated by all the chemicals tested with the exception of sodium azide. Higher mutagenicity was found when bleomycin and cyclophosphamide (CP) were activated by control S9 than by MSBE S9. In addition, inhibition of CYP1A1 microsomal activity was observed in the presence of MSBE (10?C20???g/ml). We can conclude that besides its potent antioxidant activity previously reported, MSBE may also exert a chemoprotective effect due to its capacity to inhibit CYP activity.