The structural origin and biological function of pH-sensitivity in firefly luciferases

Firefly luciferases are called pH-sensitive because their bioluminescence spectra display a typical red-shift at acidic pH, higher temperatures, and in the presence of heavy metal cations, whereas other beetle luciferases (click beetles and railroadworms) do not, and for this reason they are called pH-insensitive. Despite many studies on firefly luciferases, the origin of pH-sensitivity is far from being understood. This subject is revised in view of recent results. Some substitutions of amino-acid residues influencing pH-sensitivity in firefly luciferases have been identified. Sequence comparison, site-directed mutagenesis and modeling studies have shown a set of residues differing between pH-sensitive and pH-insensitive luciferases which affect bioluminescence colors. Some substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223-235 (Photinus pyralis sequence). A network of hydrogen bonds and salt bridges involving the residues N229-S284-E311-R337 was found to be important for affecting bioluminescence colors. It is suggested that these structural elements may affect the benzothiazolyl side of the luciferin-binding site affecting bioluminescence colors. Experimental evidence suggest that the residual red light emission in pH-sensitive luciferases could be a vestige that may have biological importance in some firefly species. Furthermore, the potential utility of pH-sensitivity for intracellular biosensing applications is considered. © The Royal Society of Chemistry and Owner Societies.

Report of a chimeric origin of transposable elements in a bovine-coding gene

Despite the wide distribution of transposable elements (TEs) in mammalian genomes, part of their evolutionary significance remains to be discovered. Today there is a substantial amount of evidence showing that TEs are involved in the generation of new exons in different species. In the present study, we searched 22,805 genes and reported the occurrence of TE-cassettes in coding sequences of 542 cow genes using the RepeatMasker program. Despite the significant number (542) of genes with TE insertions in exons only 14 (2.6%) of them were translated into protein, which we characterized as chimeric genes. From these chimeric genes, only the FAST kinase domains 3 (FASTKD3) gene, present on chromosome BTA 20, is a functional gene and showed evidence of the exaptation event. The genome sequence analysis showed that the last exon coding sequence of bovine FASTKD3 is ∼85% similar to the ART2A retrotransposon sequence. In addition, comparison among FASTKD3 proteins shows that the last exon is very divergent from those of Homo sapiens, Pan troglodytes and Canis familiares. We suggest that the gene structure of bovine FASTKD3 gene could have originated by several ectopic recombinations between TE copies. Additionally, the absence of TE sequences in all other species analyzed suggests that the TE insertion is clade-specific, mainly in the ruminant lineage. ©FUNPEC-RP.

Origin of the circumflex branch of the coronary artery. A case report

The left coronary artery usually supplies the circumflex branch which provides several atrial and ventricular branches. During a routine dissection of the coronary artery, we could detect a circumflex branch originating from the right coronary artery. This resulted in an analysis of another 59 hearts without any similar results.

Chemical properties of different peats depending on origin and analytical method

The chemical properties of 12 different peats have been analyzed by methods from VDLUFA (German Association of Agricultural Analysis and Research Institutes) and EN (European Committee for Standardization, Technical Committee 223: Soil improvers and growing media). The analyses of pH (CaCl 2), contents of salts (H 2O), nutrients (CAT), and Na and Cl (H 2O) were carried out by VDLUFA methods, while those of pH (H 2O), EC (H 2O), nutrients (CAT), Na (CAT and H 2O) and Cl (H 2O) according to EN. Ten milled or sod white peats and two dredged frozen black peats of different degrees of decomposition were used. All of them contained high amounts of Mg, while black peats were additionally high in N, Fe and Zn. The pH-values were about the same for all peats. N- and Mn-contents depended most on peat origin. Analytical values of both CAT-methods were in the same range. Extraction with H 2O (EN) as compared to CAT (EN) resulted in considerably lower values.

Homologies of floral structures in velloziaceae with particular reference to the corona

New data on floral morphology, development, and vasculature in two Brazilian genera of the monocot family Velloziaceae (Pandanales) are used to explore the homologies of their unusual floral structures, especially the corona of Barbacenia and the corona-like appendages and multiple stamens of some Vellozia species. All Velloziaceae have epigynous flowers. Some species of Vellozia are polyandrous, and stamen number can be variable within species. In Vellozia jolyi, there is a single stamen opposite each sepal and a stamen fascicle (of three secondary stamens) opposite each petal. Each stamen possesses a single vascular bundle, and these are united into a single aggregate bundle in proximal regions of the fascicle. Stamens mature centripetally within each fascicle. The coronal appendages of both genera are closely associated with the stamens, but they share some vasculature with the tepals and develop late in ontogeny. The coronal organs cannot readily be homologized with any of the typical floral organs, but they show partial homology with both tepals and stamens. They are most readily interpreted as a late elaboration of the region between the petals and stamens associated with epigyny and the hypanthium. © 2010 by The University of Chicago. All rights reserved.

Clinical assessment of ethinylestradiol and cyproterone acetate in menstrual irregularities of hyper-androgenic origin

We report on the results of a double-blind, randomized, controlled clinical trial comparing two preparations of ethinylestradiol and cyproterone acetate in the treatment of women of reproductive age presenting menstrual irregularities of hyper-androgenic origin. After obtaining informed consent, subjects were randomized to a 4-month treatment period consisting of one daily dose of 0.035mg ethinylestradiol + 2mg cyproterone acetate. The treatment regimen cycle consisted of one pill, once daily for 21 days, followed by a 7-day pill-free period. We compared the efficacy of two presentations of the drug combination after each treatment cycle (Visits 2, 3, 4, and 5) in establishment and maintenance of menstrual regulation, intensity of menstrual flow, and dysmenorrhea, as well as a comparison of the two presentations in terms of Global Satisfaction and Drug Satisfaction assessments performed by the patients and the investigating physician. At each study visit, drug compliance and use of concomitant medications, as well as incidence, severity and duration of adverse events were recorded. A total of 86 subjects were randomized to treatment, with 43 subjects in each treatment group. At Visit 2 and each subsequent visit, all patients in both treatment groups reported an episode of withdrawal bleeding during the 7-day hormone-free period. We observed a statistically significant (p<0.0001) decrease in the incidence of dysmenorrhea at each study visit in relation to the pretreatment assessment. There was a significant reduction (p<0.0001) in the number of subjects reporting intermenstrual bleeding at each study visit in both treatment groups. Global Satisfaction scores by the patient and physician increased significantly at each successive study visit in both treatment groups. There were no clinically significant changes in vital signs, weight, and body mass index throughout the study period in either group. The number of subjects reporting adverse events at each visit did not vary between treatment groups. The combined oral contraceptive pill containing ethinylestradiol and cyproterone acetate was found to be both effective and safe in the menstrual irregularities of hyper-androgenic origin (amenorrhea, dysmenorrhea, and intermenstrual bleeding) assessed in this study. © Copyright Moreira Jr. Editora. Todos os direitos reservados.

Uniconazole on mango floral induction cultivar 'Kent' at submedio são francisco region, Brazil

In order to provide efficient crop management which enables the scaling of the production of mango in semi-arid conditions and achieve a greater precision in the recommendation, evaluating the effect and the influence of uniconazole foliar spray, on the emission of vegetative flushes in the cultivar 'Kent', field tests were carried out in a productive orchard. Treatments tested were three uniconazole dosages, 500, 1,000 and 1,500 mg L-1, with one, two or three respective foliar sprayings. Another treatment with paclobutrazol was used at 2.0 g a.i./m of canopy diameter, with a single application via soil and a control (without spraying of plant growth regulators), where spreader-sticker was added and the pH was adjusted. With 30, 60 and 90 days after the first spraying of the flowering inducer the growth of branches were evaluated, as well as the percentage of flowering in all treatments after 120 days of first spraying. The sprayings started in the orchard after the emission of the second vegetative flush after pruning of production, through airassisted sprayer with flow rate of 1,000 L ha-1. The experimental design was done through randomized blocks with four replications, using three plants per plot. It was observed that paclobutrazol was significantly highlighted in relation to other treatments and that the uniconazole with one, two and three foliar sprayings presented inhibition of the vegetative growth in mango 'Kent' and showed, even at low proportions, signs of flowering.

Comparative embryology and taxonomic considerations in Eriocaulaceae (Poales)

The genus concept within Eriocaulaceae is widely discussed because it is mainly based on a small number of floral characteristics of unknown functional and evolutionary significance. The aim of the present work is to comparatively study the embryology of representatives of most genera of Eriocaulaceae to identify relevant features that might aid in circumscribing them. In Eriocaulaceae, the uniformity of the embryological characteristics makes it difficult to interpret the existing relationships among the genera. Some embryological characteristics, especially those related to the number of microsporangia, are shown to be unstable and restricted to Paepalanthoideae. The unique pollen morphology may be related to mechanical processes to accommodate the increase in volume after early formation of the pollen wall and may indicate a relationship to an inaperturate ancestor. The placentation, formerly stated to be axile, is more likely to be central due to protusions of the locular base. The shape of the proximal region of the megagametophyte may be responsible for the formation of the antipodal cyst. The seed coat structure is uniform in origin and is a consistent taxonomic characteristic of the family. A review of Eriocaulaceae is necessary, in which additional morphological and anatomical characteristics should be considered and combined. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Homologies of the flower and inflorescence in the early-divergent grass anomochloa (poaceae)

Premise of the study: The grass subfamily Anomochlooideae is phylogenetically significant as the sister group to all other grasses. Thus, comparison of their structure with that of other grasses could provide clues to the evolutionary origin of these characters. Methods: We describe the structure, embryology, and development of the flower and partial inflorescence of the monotypic Brazilian grass Anomochloa marantoidea. We compare these features with those of other early-divergent grasses such as Pharus and Streptochaeta and closely related Poales such as Ecdeiocolea. Key results: Anomochloa possesses several features that are characteristic of Poaceae, notably a scutellum, a solid style, reduced stamen number, and an ovary with a single ovule that develops into a single indehiscent fruit. Interpretation of floral patterning in Anomochloa is problematic because the ramification pattern of the florets places the bracts and axes in unusual positions relative to the primary inflorescence axis. Our study indicates that there is a single abaxial carpel in Anomochloa, probably due to a cryptic type of pseudomonomery in Anomochloa that resembles the pseudomonomery of other grasses. On the other hand, the Anomochloa flower differs from the typical grass flower in lacking lodicules and possessing four stamens, in contrast with the tristaminate condition that characterizes many other grasses. Conclusions: Using the median part of the innermost bract as a locator, we tentatively homologize the inner bract of the Anomochloa partial inflorescence with the palea of other grasses. In this interpretation, the pattern of monosymmetry due to stamen suppression differs from that of Ecdeiocolea. © 2012 Botanical Society of America.

Morphological evolution in the graminid clade: Comparative floral anatomy of the grass relatives Flagellariaceae and Joinvilleaceae

New comparative data are presented on the reproductive morphology and anatomy of two genera closely related to grasses, Flagellaria and Joinvillea, in which the flowers are superficially similar, especially in stamen morphology. This investigation demonstrates some anatomical differences between the two genera. For example, both genera depart from the 'typical' condition of tepal vasculature (three-traced outer tepals and one-traced inner tepals): in Flagellaria, each tepal receives a single vascular bundle and, in Joinvillea, each tepal is supplied by three vascular bundles. Joinvillea possesses supernumerary carpel bundles, as also found in the related family Ecdeiocoleaceae, but not in Flagellaria or grasses. In the anther, the tapetum degenerates early in Flagellaria, and is relatively persistent in Joinvillea, in which the pollen grains remain closely associated with the tapetum inside the anther locule, indicating a correlation between peripheral pollen (a feature that is common in grasses) and a persistent tapetum. This study highlights the presence of a pollen-tube transmitting tissue (PTTT) or solid style in the gynoecium of Flagellaria, as also in many Poaceae, but not in Joinvillea or Ecdeiocoleaceae. We speculate that the presence of a PTTT could represent one of the factors that facilitated the subsequent evolution of the intimately connected gynoecia that characterize grasses. © 2012 The Linnean Society of London.

Multiple brain abscess from dental origin: Case report and literature review

Background: Brain abscess of dental origin is a rare situation and deserves attention due to its high mortality rate even when adequate treatment is done. Few reports are available when dental origin is the main cause of this infection. Case report: We present the case of a 70-year-old man diagnosed with cerebral abscess caused by apical lesions located at superior and inferior teeth. The three lesions containing pus were drained from anterior and posterior brain region and the laboratory evaluation revealed the presence of Streptococcus viridians and Bacteroides. Postoperative period was uneventful with excellent recovery after 1 year of surgery. Final diagnosis was able to be done due to excellent image exams availability like computer tomography and magnetic resonance using diffusion and perfusion techniques. Discussion: The early detection of this pathology with the correct diagnosis essential to give the patient the best treatment including antimicrobial drugs and drainage is of extreme importance. © 2011 Springer-Verlag.

The taxonomic value of floral characters in Rapateaceae (Poales-Monocotyledons)

The floral anatomy of Cephalostemon, Monotrema, Rapatea, Spathanthus, and Stegolepis was studied for taxonomic purposes. All species studied share colleters between the floral parts; sepals, petals, anthers, and style covered by an ornamented cuticle; short epidermal cells with sinuous walls on the abaxial surface of the petals; tetrasporangiate anthers with phenolic idioblasts in the epidermis; endothecium with spiral thickenings; incompletely septate ovary; and anatropous, bitegmic ovules. The floral anatomy is useful not only for characterizing the family, but also for delimiting the subfamilies and genera. Sepals with silica bodies in the epidermal cells; mature anther wall composed of epidermis, endothecium, and middle layer; absence of phenolic idioblasts in the sepals, filaments, and ovary; and stylar epidermal cells with thickened external periclinal wall support Rapateoideae. Cephalostemon and Rapatea show a great number of similarities, corroborating their close relationship indicated in the phylogenetic analyses of the family. Monotrema shares few characters with the genera of Rapateoideae, corroborating its placement in Monotremoideae. Stegolepis shows several distinctive characters, probably related to the greater diversity found in this genus. © 2012 Springer-Verlag Wien.

Anatomy of the floral nectaries of some neotropical Salacioideae (Celastraceae)

Floral nectaries have contributed to the systematics of different taxonomic groups. Since those of the neotropical genera included in subfamily Salacioideae-Cheiloclinium Miers, Peritassa Miers, Salacia L. and Tontelea Aubl.-have different forms and positions, we explored their anatomy to delimit more precisely the genera of subfamily Salacioideae. Buds and open flowers of six species were treated following the usual techniques in plant anatomy. The obtained data were helpful in characterizing the floral nectary anatomy of the studied species. Furthermore, some features such as form, position and surface of nectaries; form of their epidermal cells; presence and distribution of stomata; occurrence of idioblasts containing druses in the nectariferous parenchyma; and absence of nectary vascularization can contribute to the taxonomy and phylogeny of the Salacioideae studied. In most of the studied species the nectar is probably released by both the stomata and the nectary epidermal surface. In Cheiloclinium cognatum, the structure acknowledged as nectary is actually a vestigial tissue and the functions of attracting and rewarding pollinators has phylogenetically migrated to the stigmatic region. The druses and phenolic substances observed in the nectariferous parenchyma probably help defend flowers against herbivore attacks. The minute size of the nectaries of Salacioideae may explain the absence of vascularization. The floral nectaries of Salacia elliptica are epithelial while those of the other species are mesenchymal. © 2012 Springer-Verlag Wien.

Investigation of Partamona helleri (Apidae, Meliponini) B chromosome origin. An approach by microdissection and whole chromosome painting

The stingless bee Partamona helleri in southeast Brazil shows the regular chromosome number 2n = 34 and a variable number of up to four minute B1 or B2 chromosomes. Previous cytogenetic analyses have indicated morphological similarities between the B1 chromosome and chromosome segments in the regular karyotype. In this study, microdissection and chromosome painting were employed along with C banding, NOR banding, and base-specific fluorochrome staining to investigate the origin of the B1 chromosome in P. helleri. B1-generated probe hybridized exclusively to B1 chromosomes. This result suggests an independent origin from the regular karyotype or, alternatively, that the B chromosome may have suffered substantial genetic alterations along its independent evolution. The absence of higher dosages of these small B chromosomes in this population of P. helleri may be related to the existence of either a genetic or cytogenetic constraint in the establishment of such high numbered karyotypes. © 2012 INRA, DIB and Springer-Verlag, France.

Análise química da folha d de abacaxizeiro cv. smooth cayenne antes e após a indução floral em função de doses e parcelamentos de nitrogênio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)