Electrophysiological responses of Atta sexdens rubropilosa workers to essential oils of eucalyptus and its chemical composition

The leaf-cutting ant Atta sexdens rubropilosa Forel, 1908 is the most harmful of the Eucalyptus pests, causing severe losses in wood production through defoliation. Various strategies have been tried and effort spent on the development of methods to control this pest, however no practical and environmentally acceptable one currently exists. In this work the chemical composition of the essential oil of seven Eucalyptus species was identified and the selectivity and sensitivity of antennal receptors of A. sexdens rubropilosa workers to the volatile compounds were determined using the electroantennographic technique (EAG and GC-EAD). Analysis by GC-EAD showed in E. cloesiana and E. maculata, respectively, seventeen and sixteen terpenes that elicited responses in ant workers' antennae, indicating the potential role of the essential oils as allelochemicals that determine the choice of the foraging material.     

Volatile oil from Guarea macrophylla ssp. tuberculata: seasonal variation and electroantennographic detection by Hypsipyla grandella

GC and GC-MS analyses of the volatile oils from Guarea macrophylla (Meliaceae) collected during three different periods in one year (February, June and October) indicated a seasonal variation in chemical composition. Whilst sesquiterpenes were the predominant class of components present in the leaf oil, a seasonal dependent variation in the degree of oxygenation of these compounds was detected, which seemed to be associated with phenological factors. The leaf oil, and fractions thereof, were subjected to GC coupled with electroantennographic detection employing antennae of females of Hypsipyla grandella, an insect pest that attacks several meliaceous species. Five compounds elicited significant responses and these were identified as ledol, 1-cubenol, guai-6-en-10beta-ol, 1-epi-cubenol, and tau-muurolol. The results suggest that these components could be responsible for the attraction of H. grandella to G. macrophylla.     

The fusogenic state of mayaro virus induced by low pH and by hydrostatic pressure

Mayaro virus is an enveloped virus that belongs to the Alphavirus genus. To gain insight into the mechanism involved in Mayaro virus membrane fusion, we used hydrostatic pressure and low pH to isolate a fusion-active state of Mayaro glycoproteins. In response to pressure, E1 glycoprotein undergoes structural changes resulting in the formation of a stable conformation. This state was characterized and correlated to that induced by low pH as measured by intrinsic fluorescence, 4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfonic acid, dipotassium salt fluorescence, fluorescence resonance energy transfer, electron microscopy, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In parallel, we used a neutralization assay to show that Mayaro virus in the fusogenic state retained most of the original immunogenic properties and could elicit high titers of neutralizing antibodies.     

Serological Survey of Paracoccidioidomycosis in Sheep

The objective of this study was to evaluate the prevalence of antibodies against Paracoccidioides brasiliensis in sheep from Guarapuava, Paraná State, Brazil. The seroepidemiological study was carried out in 262 sheep. The samples were analyzed by ELISA and immunodiffusion test using P. brasiliensis gp43 and exoantigen as antigens, respectively. Initially, two sheep were immunized with P. brasiliensis to evaluate whether contact with the fungal cells could induce a humoral immune response against gp43 and exoantigen from P. brasiliensis. Both animals produced antibodies against gp43 and exoantigen, the main antigens used for diagnosis and seroepidemiology of paracoccidioidomycosis. A reactivity of 37% was observed to the P. brasiliensis gp43 antigen by ELISA although no reactivity had been observed by the immunodiffusion test. Sheep under extensive grazing system showed higher frequency of positivity to P. brasiliensis (P ≤ 0.05) than those under intensive and semi-intensive systems. These data suggest that sheep may be a useful epidemiological marker of P. brasiliensis presence in the environment and reinforce that contact with soil is an important risk factor for infection.     

Oocyst shedding in cats vaccinated by the nasal and rectal routes with crude rhoptry proteins of Toxoplasma gondii

During this study, cats were immunized by the intranasal and rectal routes with crude rhoptry proteins of Toxoplasma gondii admixed with Quil-A. Twenty-five domestic short hair cats divided into five groups (n=5) were used during this evaluation: G1 and G3 cats received 200 μg of the rhoptry proteins with Quil-A (20 μg) by the intranasal and rectal routes, respectively; G2 and G4 cats received bovine serum albumin (BSA, 200 μg/dose) with Quil-A (20 μg); and G5 animals served as unvaccinated controls. All treatments were performed at days 0, 21, 42, and 63. The challenge was done with 800 cysts of the ME49 of T. gondii strain at day 70 (challenge day). The serum IgG, IgM, IgA, and fecal IgA antibody levels were evaluated by using the indirect enzyme-linked immunosorbent assay (ELISA). Some animals produced antibody levels beyond cut-off; however, two animals from G1 (OD(mean)=0.308, OD(cut-off)=0.200) and three from G3 (OD(mean)=0.254) demonstrated IgG levels on being challenged, with similar results occurring in two cats from G1 to IgM (OD(mean)=0.279, OD(cut-off)=0.200). Fecal IgA levels were detected in all G1 cats (OD(mean)=0.330, OD(cut-off)=0.065), and in one cat from G3 (OD(mean)=0.167). The serum and fecal humoral immune responses did not correlate with oocyst shedding. Oocyst shedding varied from 98.4% (G1), 87.5% (G2), 53.0% (G3), to 58% (G4), and was lower than that of G5 cats. The prepatent period of cats vaccinated intranasally (G1) was reduced from 6-9.6 to 2.8 days, suggesting protection of environmental contamination, considering cats as the primary source of contamination. The intranasally and rectally administered rhoptry vaccines were able to partially protect cats against T. gondii cysts on being challenged; however, the intranasal method of vaccination yielded better results relative to the rectal route.     

Regeneration and characterization of somatic hybrids combining sweet orange and mandarin/mandarin hybrid cultivars for citrus scion improvement

Protoplast fusion between sweet orange and mandarin/mandarin hybrids scion cultivars was performed following the model ??diploid embryogenic callus protoplast?+?diploid mesophyll-derived protoplast??. Protoplasts were isolated from embryogenic calli of ??Pera?? and ??Westin?? sweet orange cultivars (Citrus sinensis) and from young leaves of ??Fremont??, Nules??, and ??Thomas?? mandarins (C. reticulata), and ??Nova?? tangelo [C. reticulata?×?(C. paradisi?×?C. reticulata)]. The regenerated plants were characterized based on their leaf morphology (thickness), ploidy level, and simple sequence repeat (SSR) molecular markers. Plants were successfully generated only when ??Pera?? sweet orange was used as the embryogenic parent. Fifteen plants were regenerated being 7 tetraploid and 8 diploid. Based on SSR molecular markers analyses all 7 tetraploid regenerated plants revealed to be allotetraploids (somatic hybrids), including 2 from the combination of ??Pera?? sweet orange?+???Fremont?? mandarin, 3 ??Pera?? sweet orange?+???Nules?? mandarin, and 2 ??Pera?? sweet orange?+???Nova?? tangelo, and all the diploid regenerated plants showed the ??Pera?? sweet orange marker profile. Somatic hybrids were inoculated with Alternaria alternata and no disease symptoms were detected 96?h post-inoculation. This hybrid material has the potential to be used as a tetraploid parent in interploid crosses for citrus scion breeding.     

Anti-atherogenic and anti-angiogenic activities of polyphenols from propolis

Propolis is a polyphenol-rich resinous substance extensively used to improve health and prevent diseases. The effects of polyphenols from different sources of propolis on atherosclerotic lesions and inflammatory and angiogenic factors were investigated in LDL receptor gene (LDLr?/?) knockout mice. The animals received a cholesterol-enriched diet to induce the initial atherosclerotic lesions (IALs) or advanced atherosclerotic lesions (AALs). The IAL or AAL animals were divided into three groups, each receiving polyphenols from either the green, red or brown propolis (250 mg/kg per day) by gavage. After 4 weeks of polyphenol treatment, the animals were sacrificed and their blood was collected for lipid profile analysis. The atheromatous lesions at the aortic root were also analyzed for gene expression of inflammatory and angiogenic factors by quantitative real-time polymerase chain reaction and immunohistochemistry. All three polyphenol extracts improved the lipid profile and decreased the atherosclerotic lesion area in IAL animals. However, only polyphenols from the red propolis induced favorable changes in the lipid profiles and reduced the lesion areas in AAL mice. In IAL groups, VCAM, MCP-1, FGF, PDGF, VEGF, PECAM and MMP-9 gene expression was down-regulated, while the metalloproteinase inhibitor TIMP-1 gene was up-regulated by all polyphenol extracts. In contrast, for advanced lesions, only the polyphenols from red propolis induced the down-regulation of CD36 and the up-regulation of HO-1 and TIMP-1 when compared to polyphenols from the other two types of propolis. In conclusion, polyphenols from propolis, particularly red propolis, are able to reduce atherosclerotic lesions through mechanisms including the modulation of inflammatory and angiogenic factors.     

Screening of plant growth promoting Rhizobacteria isolated from sunflower (Helianthus annuus L.)

Background and Aims

This study was aimed at assessing the diversity of putatively diazotrophic rhizobacteria associated with sunflower (Helianthus annuus L.) cropped in the south of Brazil, and to examine key plant growth promotion (PGP) characteristics of the isolates for the purposes of increasing plant productivity.

Methods

299 strains were isolated from the roots and rhizosphere of sunflower cultivated in five different areas using N-free media. 16S rDNA PCR-RFLP and 16S rRNA partial sequencing were used for identification and the Shannon index was used to evaluate bacterial diversity. Production of siderophores and indolic compounds (ICs), as well phosphate solubilization activities of each isolate were also evaluated in vitro. On the basis of multiple PGP activities, eight isolates were selected and tested for their N-fixation ability, and their capacity as potential PGPR on sunflower plants was also assessed.

Results

All except three Gram-positive strains (phylum Actinobacteria) belonged to the Gram-negative Proteobacteria subgroups [Gamma (167), Beta (78), and Alpha (50)] and the family Flavobacteriaceae (1)]. Shannon indexes ranged from 0.96 to 2.13 between the five sampling sites. Enterobacter and Burkholderia were the predominant genera isolated from roots and rhizosphere, respectively. Producers of siderophores and ICs were widely found amongst the isolates, but only 19.8% of them solubilized phosphate. About 8% of the isolates exhibited all three PGP traits, and these mostly belonged to the genus Burkholderia. Four isolates were able to stimulate the growth of sunflower plants under gnotobiotic conditions.

Conclusions

Enterobacter and Burkholderia were the dominant rhizospheric bacterial genera associated with sunflower plants. Inoculation with isolates belonging to the genera Achromobacter, Chryseobacterium, Azospirillum, and Burkholderia had a stimulatory effect on plant growth.     

Standardised measures of needs,stigma and informal care in schizophrenia using a bottom-up,cross-cultural approach

Background There is a lack of instruments to measure the needs, stigma and informal care of people with schizophrenia that take account of sociocultural variation and patients'' and formal and informal carers'' opinions and experiences.Aims To develop questionnaires to measure stigma, needs and informal (non-professional) care for people with schizophrenia.Method We undertook the study in seven countries and in English, Spanish and Portuguese. We first held focus group discussions with patients, formal carers (professionals) and informal carers (family and friends) in Spain, the UK, Argentina, Brazil, Chile and Venezuela to elicit the main dimensions of needs, stigma and informal care. We then held nominal group discussions about these dimensions with patients, family members and professionals in Spain, Portugal and the UK, to develop the instruments.Results Three hundred and three people participated in 46 focus groups and results were discussed in three nominal groups, each involving eight participants. Three instruments were developed in this iterative process: needs for care (46 items), stigma (38 items) and informal care (20 items).Conclusions These instruments are based on service users'' and carers'' views and experiences and have cross-cultural validity. They will have application in assessment of outcomes for people with schizophrenia and their families.     

Influence of forward leaning and incentive spirometry on inspired volumes and inspiratory electromyographic activity during breathing exercises in healthy subjects

Breathing exercises (BE), incentive spirometry and positioning are considered treatment modalities to achieve lung re-expansion. This study evaluated the influence of incentive spirometry and forward leaning on inspired tidal volumes (V_T) and electromyographic activity of inspiratory muscles during BE. Four modalities of exercises were investigated: deep breathing, spirometry using both flow and volume-oriented devices, and volume-oriented spirometry after modified verbal instruction. Twelve healthy subjects aged 22.7 ± 2.1 years were studied. Surface electromyography activity of diaphragm, external intercostals, sternocleidomastoid and scalenes was recorded. Comparisons among the three types of exercises, without considering spirometry after modified instruction, showed that electromyographic activity and V_T were lower during volume-oriented spirometry (p = 0.000, p = 0.054, respectively). Forward leaning resulted in a lower V_T when compared to upright sitting (p = 0.000), but electromyographic activity was not different (p = 0.606). Inspired V_T and electromyographic activity were higher during volume-oriented spirometry performed after modified instruction when compared with the flow-oriented device (p = 0.027, p = 0.052, respectively). In conclusion BE using volume-oriented spirometry before modified instruction resulted in a lower work of breathing as a result of a lower V_T and was not a consequence of the device type used. Forward leaning might not be assumed by healthy subjects during situations of augmented respiratory demand.