Distribution of <Emphasis Type="Italic">Aceria guerreronis</Emphasis> and <Emphasis Type="Italic">Neoseiulus baraki</Emphasis> among and within coconut bunches in northeast Brazil

Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of coconut in many countries in the Americas, Africa and parts of Asia. Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) is one of the predatory mites most commonly found in association with A. guerreronis in parts of northeast Brazil. The objective of this work was to study the distribution of A. guerreronis and N. baraki among and within coconut bunches. The hypothesis was tested that A. guerreronis and N. baraki are homogenously distributed over the fruits in a bunch, independent of the fruits’ age and position. Five collections of bunches, each corresponding to leaves 12–16 from apex (about 2–6 month-old), were conducted in each of three fields in northeastern Brazil, from February to October, 2007. A total of 1,986 fruits were examined. The number of mites, the percentage of fruits hosting them and the level of damage caused by A. guerreronis were evaluated. The highest density of A. guerreronis was observed on fruits of bunch 4 whereas the highest density of N. baraki was observed on bunch 5. Considering all fruits together, no significant differences were observed between densities of either A. guerreronis or N. baraki among the basal, median and apical thirds of the bunches. In younger bunches, fruits of the apical region tend to have lower densities of both mites than fruits of the basal region. This pattern, in association with a similar pattern for the percentage of fruits hosting N. baraki, suggests that the predator initially reaches the basal bunch region, from where it moves to the apical region. The results of the present study suggest that the pest population reduction in bunches older than bunch 4 could be due to (1) an effect of the predator, (2) reduction of the proportion of undamaged tissues amenable to attack, and/or (3) less favorable characteristics of the fruits to attack by A. guerreronis, as indicated by their increasing lignin content as they get older.     

Life history of <Emphasis Type="Italic">Proctolaelaps bulbosus</Emphasis> feeding on the coconut mite <Emphasis Type="Italic">Aceria guerreronis</Emphasis> and other possible food types occurring on coconut fruits

Aceria guerreronis Keifer (Acari: Eriophyidae) is a major pest of coconut fruits (Cocos nucifera L.) in many countries of the Americas, Africa, and parts of Asia. Considerable attention has been given to studies of biological control agents of A. guerreronis. Proctolaelaps bulbosus Moraes, Reis and Gondim Jr. is a predator recently discovered in association with A. guerreronis. Nothing is known about its biology. The aim of this study was to determine suitable food sources for P. bulbosus, among items commonly found on coconut fruits, including A. guerreronis. Food sources evaluated included the mites A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank), the fungus Rhizopus aff. stolonifer (Ehrenb.) Vuill and coconut pollen; the mite Tetranychus urticae Koch was also included in the assessments, for being a commonly used prey for mass production and laboratory rearing of predatory mites. Proctolaelaps bulbosus was able to develop up to adulthood when fed A. guerreronis, R. aff. stolonifer and T. putrescentiae. It had the highest population growth rates when feeding on the former (R _o = 17.5; r _m = 0.392). These results indicate that A. guerreronis is the most suitable food for P. bulbosus among the possible food sources found on coconut fruits and that P. bulbosus can survive in the absence of eriophyid using R. aff. stolonifer as a food source.     

Imbalanced circulating matrix metalloproteinases in polycystic ovary syndrome

Altered levels of matrix metalloproteinases (MMPs) may reflect relevant pathogenetic mechanisms of disease conditions. The objective of this study was to compare the plasma levels of MMPs and tissue inhibitors of MMPs (TIMPs) in polycystic ovary syndrome (PCOS) patients with those found in healthy ovulatory controls and to examine whether the levels of these biomarkers are associated with clinical and biochemical features of this syndrome. Sixty-five healthy ovulatory subjects (controls) and 80 patients with PCOS were include in this study. MMP-2, MMP-8, MMP-9, TIMP-1, TIMP-2 concentrations were measured in plasma samples by gelatin zymography or enzyme-linked immunoassays. MMP-2, MMP-8, MMP-9, and TIMP-1 levels were similar in PCOS patients and in healthy controls (P > 0.05). PCOS patients had lower plasma TIMP-2 levels than healthy controls (P < 0.05). We found higher MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios in PCOS patients than in healthy controls (all P < 0.05). Testosterone levels correlated positively with the MMP-9/TIMP-1 ratio and negatively with TIMP-2 levels (r = 0.26, P < 0.01 and r = -0.21, P = 0.02, respectively). In addition, only testosterone was an independent predictor of TIMP-2 levels (estimate = -0.35, P = 0.04) and the MMP-9/TIMP-1 ratio (estimate = 0.01, P = 0.04). We found evidence indicating that the balance between MMPs and TIMPs in women with PCOS is altered, probably due to androgen excess found in these women.     

Microscopic and molecular characterization of ovarian follicle atresia in Rhodnius prolixus Stahl under immune challenge

In this work we characterized the degenerative process of ovarian follicles of the bug Rhodnius prolixus challenged with the non-entomopathogenic fungus Aspergillus niger. An injection of A. niger conidia directly into the hemocoel of adult R. prolixus females at the onset of vitellogenesis caused no effect on host lifespan but elicited a net reduction in egg batch size. Direct inspection of ovaries from the mycosed insects revealed that fungal challenge led to atresia of the vitellogenic follicles. Light microscopy and DAPI staining showed follicle shrinkage, ooplasm alteration and disorganization of the monolayer of follicle cells in the atretic follicles. Transmission electron microscopy of thin sections of follicle epithelium also showed nuclei with condensed chromatin, electron dense mitochondria and large autophagic vacuoles. Occurrence of apoptosis of follicle cells in these follicles was visualized by TUNEL labeling. Resorption of the yolk involved an increase in protease activities (aspartyl and cysteinyl proteases) which were associated with precocious acidification of yolk granules and degradation of yolk protein content. The role of follicle atresia in nonspecific host-pathogen associations and the origin of protease activity that led to yolk resorption are discussed.     

Identification of phenolic compounds in isolated vacuoles of the medicinal plant Catharanthus roseus and their interaction with vacuolar class III peroxidase: an H₂O₂ affair?

Class III peroxidases (Prxs) are plant enzymes capable of using H(2)O(2) to oxidize a range of plant secondary metabolites, notably phenolic compounds. These enzymes are localized in the cell wall or in the vacuole, which is a target for secondary metabolite accumulation, but very little is known about the function of vacuolar Prxs. Here, the physiological role of the main leaf vacuolar Prx of the medicinal plant Catharanthus roseus, CrPrx1, was further investigated namely by studying its capacity to oxidize co-localized phenolic substrates at the expense of H(2)O(2). LC-PAD-MS analysis of the phenols from isolated leaf vacuoles detected the presence of three caffeoylquinic acids and four flavonoids in this organelle. These phenols or similar compounds were shown to be good CrPrx1 substrates, and the CrPrx1-mediated oxidation of 5-O-caffeoylquinic acid was shown to form a co-operative regenerating cycle with ascorbic acid. Interestingly, more than 90% of total leaf Prx activity was localized in the vacuoles, associated to discrete spots of the tonoplast. Prx activity inside the vacuoles was estimated to be 1809 nkat ml(-1), which, together with the determined concentrations for the putative vacuolar phenolic substrates, indicate a very high H(2)O(2) scavenging capacity, up to 9 mM s(-1). Accordingly, high light conditions, known to increase H(2)O(2) production, induced both phenols and Prx levels. Therefore, it is proposed that the vacuolar couple Prx/secondary metabolites represent an important sink/buffer of H(2)O(2) in green plant cells.     

Genetic dissection of vitamin E biosynthesis in tomato

Vegetables are critical for human health as they are a source of multiple vitamins including vitamin E (VTE). In plants, the synthesis of VTE compounds, tocopherol and tocotrienol, derives from precursors of the shikimate and methylerythritol phosphate pathways. Quantitative trait loci (QTL) for α-tocopherol content in ripe fruit have previously been determined in an Solanum pennellii tomato introgression line population. In this work, variations of tocopherol isoforms (α, β, γ, and δ) in ripe fruits of these lines were studied. In parallel all tomato genes structurally associated with VTE biosynthesis were identified and mapped. Previously identified VTE QTL on chromosomes 6 and 9 were confirmed whilst novel ones were identified on chromosomes 7 and 8. Integrated analysis at the metabolic, genetic and genomic levels allowed us to propose 16 candidate loci putatively affecting tocopherol content in tomato. A comparative analysis revealed polymorphisms at nucleotide and amino acid levels between Solanum lycopersicum and S. pennellii candidate alleles. Moreover, evolutionary analyses showed the presence of codons evolving under both neutral and positive selection, which may explain the phenotypic differences between species. These data represent an important step in understanding the genetic determinants of VTE natural variation in tomato fruit and as such in the ability to improve the content of this important nutriceutical.     

The activity of platelet activating factor-acetyl hydrolase (PAF-AH) in the salivary glands of Rhodnius prolixus

In this work, we investigated the activity of the platelet activating factor acetyl hydrolase (PAF-AH) in the salivary gland homogenates and saliva of Rhodnius prolixus. PAF-AH activity in the salivary gland homogenates was lower than in the saliva. Preliminary characterization of the enzyme demonstrated that it hydrolyzed the substrate 2-thio-PAF, was detectable just in 1 pair of salivary gland homogenates in 0.5 ml buffer, and was stable under different conditions. PMSF, TPCK, TLCK, pepstatin A and p-BPB all inhibited the PAF-AH activity. Enzyme specific activity in salivary gland homogenates diminished immediately after feeding of 5th-instar larvae, and increased before feeding by adult insects. 2-Thio-PAF induced platelet-aggregation that was inhibited by previous incubation of the substrate with salivary gland homogenates or saliva. The relevance of PAF-AH for providing Rhodnius with a feeding mechanism for facilitating the sucking of a high volume of blood meal in a short period is discussed.     

SNPs in DNA repair genes associated to meningitis and host immune response

In vitro and in animal models, APE1, OGG1, and PARP-1 have been proposed as being involved with inflammatory response. In this work, we have investigated if the SNPs APE1 Asn148Glu, OGG1 Ser326Cys, and PARP-1 Val762Ala are associated to meningitis. The patient genotypes were investigated by PIRA-PCR or PCR-RFLP. DNA damages were detected in genomic DNA by Fpg treatment. IgG and IgA were measured from plasma and the cytokines and chemokines were measured from cerebrospinal fluid samples using Bio-Plex assays. A higher frequency (P<0.05) of APE1 Glu allele in bacterial meningitis (BM) and aseptic meningitis (AM) patients was observed. The genotypes Asn/Asn in control group and Asn/Glu in BM group was also higher. For the SNP OGG1 Ser326Cys, the genotype Cys/Cys was more frequent (P<0.05) in BM group. The frequency of PARP-1 Val/Val genotype was higher in control group (P<0.05). The occurrence of combined SNPs is significantly higher in BM patients, indicating that these SNPs may be associated to the disease. Increasing in sensitive sites to Fpg was observed in carriers of APE1 Glu allele or OGG1 Cys allele, suggesting that SNPs affect DNA repair activity. Alterations in IgG production were observed in the presence of SNPs APE1 Asn148Glu, OGG1 Ser326Cys or PARP-1 Val762Ala. Moreover, reduction in the levels of IL-6, IL-1Ra, MCP-1/CCL2 and IL-8/CXCL8 was observed in the presence of APE1 Glu allele in BM patients. In conclusion, we obtained indications of an effect of SNPs in DNA repair genes on the regulation of immune response in meningitis.     

Association of the infusion of Heteropterys aphrodisiaca and endurance training brings spermatogenetic advantages

The species Heteropterys aphrodisiaca is commonly used as a stimulant by popular medicine in the Cerrado, a savanna-like biome, Brazil. Recent studies have proved its protective effects on testes of animals submitted to treatment using Cyclosporine A, as well as its stimulus effect in increasing testosterone secretion. Therefore, the present study was designed to analyze whether the association of the plant infusion and endurance exercise could potentiate the stimulating effect. The animals were separated into 4 groups: two control (sedentary and trained) receiving water and two treated (sedentary and trained) receiving the plant infusion daily (104 mg/day). The proportion of the seminiferous tubule compartment and interstitium was analyzed. Within the seminiferous epithelium, the number of Sertoli and germ cells were counted in order to evaluate whether the treatment would alter the spermatogenic dynamics, analyzing: the spermatogenic yield, the mitotic and meiotic indexes, the total number of germ cells and the Sertoli cell support capacity. Trained and treated animals showed increased spermatogenic yield and spermatogonia mitosis, and no significant differences in apoptotic indexes. Despite the results showing the same pattern regarding yield and mitotic index, the meiotic index was higher in the sedentary/treated group. Therefore, the H. aphrodisiaca infusion increased both the testosterone production and the spermatogonia mitosis, thus increasing the spermatogenic yield.