Resolving the non‐papilionaceous flower of Camoensia scandens,a papilionoid legume of the core genistoid clade: development,glands and insights into the pollination and systematics of the group

Journal of Plant Research - Camoensia scandens is a papilionoid legume inserted in the core genistoid clade. It has large, crepuscular, scented flowers but the corolla is non-papilionaceous, which...     

Negative effect of a cis-acting pBR322 element on adenovirus E1a gene expression

A sequence element within plasmid pBR322 has a cis-acting negative effect on the expression of a cloned Ad gene in transient expression assays. The negative element is located between the PvuII and Tth111I restriction sites on pBR322 (nt 2068-2223). This element was also shown to be responsible for the decrease in focus number, when plasmids carrying Ad2 E1 genes were used to transform baby rat kidney cells. In a similar manner, this element diminished the number of G418-resistant cell foci, when plasmids containing the neo marker gene under the control of E1a promoter were used. Plasmid stability in transfected cells was not modified by deletion of this cis-acting negative element.     

Polyserositis in a patient with acute paracoccidioidomycosis and hepatosplenic schistosomiasis

A severe case of juvenile paracoccidioidomycosis (PCM), manifested as cholestatic jaundice, lymphnode enlargement and an unusual form of polyserositis, associated with portal hypertension secondary to schistosomiasis, as well as bactermias caused byE. coli andS. aureus and post-transfusional hepatitis C is reported. Temporary unresponsiveness of in vivo and in vitro cellular immune responses toP. brasiliensis were registered. The authors discuss the possible interference of either agent in the host immune response, thus explaining the severity of PCM in the present case.     

Stigma Diversity in Tropical Legumes with Considerations on Stigma Classification

The great stigma diversity in angiosperms implies a choice of criteria for stigma classification, which nowadays is characterized as dry (= little or no secretory surface and exudate retained by the cuticle and/or protein pellicle), wet (= conspicuous secretory surface, abundant in fluid exudate) and semidry (exudate retained by cuticle and/or protein pellicle). Despite being a very species-rich family, whose representatives exhibit a wide floral variation, no comparative studies of stigma diversity have been done for the whole Leguminosae. In order to assess the stigma morphological diversity in legumes and to evaluate the criteria used in the main classifications of the stigma, we compared the stigma morphology in 15 distinct legume lineages. In addition, we evaluated the stigma classification in other 152 legume species whose morphology was already described in the literature. Stigmas were removed from floral buds and flowers and processed for analyses under scanning electron and light microscopes. The stigma of the study legumes exhibits quite variable morphology, mainly concerning the diameter, the occurrence of an orifice or a furrow, the coating, the cellular composition, and the occurrence, chemical nature and release mechanism of the exudate. This diversity appears to be related mainly to the evolutionary history of the group and also to the selective pressures exerted by different types of pollen and pollinator. More conflicting criteria for stigma classification lie in defining the semidry type, found mostly in papilionoids. For better stigma classification we suggest that stigma morphology be evaluated at the time prior to anthesis, when the cuticle is not yet broken and the exudate is not exposed or drained. In addition, several techniques should be employed for a better classification.     

Novel 3-hydroxy-4-pyridinonato oxidovanadium(IV) complexes to investigate structure/activity relationships

A previous evaluation of the insulin-like activity of three 3-hydroxy-4-pyridinonato oxidovanadium(IV) complexes raised questions about structure/activity relationships, namely the influence of the hydrophilic/lipophilic balance of the complex and the capacity of the ligand to stabilize the +4 oxidation state of vanadium ion, on achieving an positive effect. To address these questions, we synthesized six new oxidovanadium(IV) complexes with variable hydrophilic/lipophilic balance, obtained by introducing different substituents on the nitrogen atom, and used two 3-hydroxy-4-pyrones as starting reagents to provide methyl and ethyl groups in the ortho position of the ring. For the new and previously reported complexes, we studied the oxidation-reduction properties and insulin-like activity in terms of inhibitory effect on Free fatty acid (FFA) release in isolated rat adipocytes. The results obtained show that only one of the complexes, Bis(3-hydroxy-1(H)-2-methyl-4-pyridonato)oxidovanadium(IV), VO(mpp)₂, exhibits a significantly greater capacity to inhibit FFA release than VOSO₄ and consequently is worthy to be considered for further studies. The establishment of structure activity relationships was not attainable but this study brings new information about the influence of some properties of the compounds on the achievement of an insulin-like effect. The results reveal that: (i) the oxidation-reduction cycles of the complexes are identical; (ii) the presence of more lipophilic substituents on the nitrogen atom does not enhance insulin-like properties; (iii) a high solubility in water proved to be not sufficient for a positive activity in inhibiting FFA release; (iv) a small molecular size may be an important property for reaching the right targets.     

Characterization of the snake venoms from seven Brazilian species of Bothrops by FPLC anion-exchange chromatography.

1. The elution profiles and the caseinolytic, myotoxic, coagulant and hemorrhagic activities of the venoms of seven Bothrops species fractionated on a Mono-Q FPLC column were analyzed. 2. Each venom separated into 16-20 peaks, with good reproducibility and the activities were concentrated in virtually discrete regions of the chromatogram. 3. There is a considerable overlap of active proteins in the different species venoms and our results indicate that a venom pool with the species B. jararaca, B. jararacussu, B. moojeni, B. neuwiedi and B. atrox venoms would contain the major active proteins determined in the seven species.     

Weissella: An Emerging Bacterium with Promising Health Benefits

Weissella strains have been the subject of much research over the last 5 years because of the genus’ technological and probiotic potential. Certain strains have attracted the attention of the pharmaceutical, medical, and food industries because of their ability to produce antimicrobial exopolysaccharides (EPSs). Moreover, Weissella strains are able to keep foodborne pathogens in check because of the bacteriocins, hydrogen peroxide, and organic acids they can produce; all listed have recognized pathogen inhibitory activities. The Weissella genus has also shown potential for treating atopic dermatitis and certain cancers. W. cibaria, W. confusa, and W. paramesenteroides are particularly of note because of their probiotic potential (fermentation of prebiotic fibers) and their ability to survive in the gastrointestinal tract. It is important to note that most of the Weissella strains with these health-promoting properties have been shown to be save safe, due to the absence or the low occurrence of virulence or antibiotic-resistant genes. A large number of scientific studies continue to report on and to support the use of Weissella strains in the food and pharmaceutical industries. This review provides an overview of these studies and draws conclusions for future uses of this rich and previously unexplored genus.

     

Ectophosphatase activity in the triple-negative breast cancer cell line MDA-MB-231

Breast cancer is one of the most common cancers in the female population worldwide, and its development is thought to be associated with genetic mutations that lead to uncontrolled and accelerated growth of breast cells. This abnormal behavior requires extra energy, and indeed, tumor cells display a rewired energy metabolism compared to normal breast cells. Inorganic phosphate (Pi) is a glycolytic substrate of glyceraldehyde-3-phosphate dehydrogenase and has an important role in cancer cell proliferation. For cells to obtain Pi, ectoenzymes in the plasma membrane with their catalytic site facing the extracellular environment can hydrolyze phosphorylated molecules, and this is an initial and possibly limiting step for the uptake of Pi by carriers that behave as adjuvants in the process of energy harvesting and thus partially contributes to tumor energy requirements. In this study, the activity of an ectophosphatase in MDA-MB-231 cells was biochemically characterized, and the results showed that the activity of this enzyme was higher in the acidic pH range and that the enzyme had a K_m = 4.5 ± 0.5 mM para-nitrophenylphosphate and a V_max = 2280 ± 158 nM × h⁻¹ × mg protein⁻¹. In addition, classical acid phosphatase inhibitors, including sodium orthovanadate, decreased enzymatic activity. Sodium orthovanadate was able to inhibit ectophosphatase activity while also inhibiting cell proliferation, adhesion, and migration, which are important processes in tumor progression, especially in metastatic breast cancer MDA-MB-231 cells that have higher ectophosphatase activity than MCF-7 and MCF-10 breast cells.     

The Effects of Nutrient Concentration,Addition of Thickeners,and Agitation Speed on Liquid Fermentation of Steinernema feltiae

Entomopathogenic nematode production in liquid fermentation still requires improvements to maximize efficiency, yield, and nematode quality. Therefore, this study was aimed at developing a more suitable liquid medium for mass production of Steinernema feltiae, by assessing the effects of nutrient concentration, thickeners (primarily agar), and agitation speed on infective juvenile (IJ) yield. Base medium (BM) contained yeast extract (2.3%), egg yolk (1.25%), NaCl (0.5%), and corn oil (4%). All media were inoculated with Xenorhabdus bovienii, and 2 d later, with 2-d-old S. feltiae juveniles. For the nutrient concentration experiment, we evaluated the base medium versus a modified base medium containing all the components, but with 3× concentrations of yeast extract (6.9%), egg yolk (3.75%), and corn oil (12%). The nematodes and bacteria were cultured in 150-ml Erlenmeyer flasks containing 50 ml of liquid medium at (25°C) and 180 rpm on a rotary shaker incubator. To assess the effect of thickeners, IJs were inoculated in BM with agar (0.2%), carrageen (0.2%), and carboxymethyl cellulose (0.2% and 0.5%). The addition of 3× more nutrients relative to the BM resulted in a significantly lower yield of nematodes. For agar and agitation speed experiments, five levels of agar in the BM (0%, 0.2%, 0.4%, 0.6%, and 0.8% agar) and two agitation speeds (180 and 280 rpm) were evaluated for production. Increasing agitation speed from 180 to 280 rpm and higher levels of agar in the medium (> 0.2%) significantly increased the yield of bacteria. At the lower agitation speed, media amended with 0.4% and 0.6% agar produced higher nematode yields compared to media without agar. Media with 0.2% and 0.8% agar resulted in intermediate levels of nematode production. At the higher agitation speed, media supplemented with 0.8% agar resulted in the lowest yield of nematodes when compared to the other media tested. Results indicated that increasing nutrient concentration levels was detrimental to nematode production. Also, media containing agar (0.4% and 0.6%) increased nematode yields when cultures were grown at low agitation speed. When IJs were used as the inoculum, 0.2% agar also enhanced recovery and nematode yield at the higher agitation speed.     

Immune response dynamics and Lutzomyia longipalpis exposure characterize a biosignature of visceral leishmaniasis susceptibility in a canine cohort

BackgroundReports have shown correlations between the immune response to vector saliva and Leishmaniasis outcome. We followed dogs in an endemic area for two years characterizing resistance or susceptibility to canine visceral leishmaniasis (CVL) according to Leishmania infantum diagnosis and clinical development criteria. Then, we aimed to identify a biosignature based on parasite load, serum biological mediators’ interactions, and vector exposure intensity associated with CVL resistance and susceptibility.Methodology/Principal findingsA prospective two-year study was conducted in an area endemic for CVL. Dogs were evaluated at 6-month intervals to determine infection, clinical manifestations, immune profile, and sandfly exposure. CVL resistance or susceptibility was determined upon the conclusion of the study. After two years, 78% of the dogs were infected with L. infantum (53% susceptible and 47% resistant to CVL). Susceptible dogs presented higher splenic parasite load as well as persistence of the parasite during the follow-up, compared to resistant ones. Susceptible dogs also displayed a higher number of correlations among the investigated biological mediators, before and after infection diagnosis. At baseline, anti-saliva antibodies, indicative of exposure to the vector, were detected in 62% of the dogs, reaching 100% in one year. Higher sandfly exposure increased the risk of susceptibility to CVL by 1.6 times (CI: 1.11–2.41). We identified a discriminatory biosignature between the resistant and susceptible dogs assessing splenic parasite load, interaction of biological mediators, PGE₂ serum levels and intensity of exposure to sandfly. All these parameters were elevated in susceptible dogs compared to resistant animals.Conclusions/SignificanceThe biosignature identified in our study reinforces the idea that CVL is a complex multifactorial disease that is affected by a set of factors which are correlated and, for a better understanding of CVL, should not be evaluated in an isolated way.