Alternative splicing of human prostaglandin G/H synthase mRNA and evidence of differential regulation of the resulting transcripts by transforming growth factor beta 1, interleukin 1 beta, and tumor necrosis factor alpha.

Prostaglandin G/H synthase (PGG/HS) is the rate-limiting enzyme in the conversion of arachidonic acid to prostaglandins and thromboxanes. We screened a human lung fibroblast cDNA library with an ovine PGG/HS cDNA and isolated a 2.3-kilobase clone (HCO-T9). Sequence analysis of this clone showed that (a) it contained the entire translated region of PGG/HS and (b) it displayed an in-frame splicing of the last 111 base pairs encoded by exon 9, which resulted in the elimination of the N-glycosylation site at residue 409. Polymerase chain reaction amplification with specific oligonucleotides of reverse-transcribed mRNA from diverse human tissues and cultured cells yielded 400- and 300-base pair fragments that corresponded, respectively, to the intact and spliced transcripts. The expression of these two transcripts in cultured human lung fibroblasts was differentially regulated by serum, transforming growth factor beta 1, interleukin 1 beta, tumor necrosis factor alpha, and phorbol 12-myristate 13-acetate, as each of these conditions stimulated preferentially the expression of the unspliced transcripts. The elimination of one of the four N-glycosylation sites by the alternative splicing of exon 9 and the differential regulation of this process by relevant cytokines and growth factors may represent a mechanism for the regulation of PGG/HS enzymatic activity under physiological or pathological conditions

A free boundary model for oxygen diffusion in a spherical medium

The goal of this article is to find a correct approximated solution using a polynomial of sixth degree for the free boundary problem corresponding to the diffusion of oxygen in a spherical medium with simultaneous absorption at a constant rate, and to show some mistakes in previously published solutions.Comment: 10 pages, 6 figures and 2 tables. Paper accepted, in press in Journal of Biological Systems (2015

Promoting vessel stabilization : toward a safe mode of therapeutic angiogenesis

Blood vessel growth is a complex process that requires the coordinated interactions of many signaling pathways and different cell types. However, despite this molecular complexity, the whole cascade of events can be set in motion by a single factor, VEGF, that is the most important regulator of both physiological and pathological angiogenesis and its over-expressed has been investigated in several ischemic tissues with the aim to restore blood flow supply. However, VEGF gene delivery presents two main limitations that make it challenging to achieve therapeutic angiogenesis in a clinical setting: 1) VEGF can induce normal or aberrant angiogenesis depending strictly on its expression level in the microenvironment around each producing cell in vivo and not on its total dose. Therefore, itÕs not sufficient to control the total amount of delivered VEGF-expressing vector, but it is necessary to control the distribution of expression levels from each transduced cell in vivo 2) In addition, new induced vessels require at least 4 weeks of expression in order to become stable and independent from further VEGF signaling. The use of short-term expressing gene therapy vectors, such as adenoviruses, is desirable both for the intrinsic safety of limited duration of expression and for the convenience of an off-the-shelf treatment. However, traditional short-term expressing vectors cannot fulfill the requirements of either dose control and or sufficient duration of expression necessary in order to induce safe and efficient angiogenesis Myoblast-mediated gene transfer provides a highly controlled delivery system that allows the selection and the in vitro characterization of myoblasts expressing specific VEGF levels and ensures a sustained expression over time. Using this tool, we previously found that co-expression of PDGF-BB, which controls pericyte recruitment and vascular maturation, ensures the induction of only normal and functional capillaries despite the expression of high and heterogeneous VEGF levels. Here, we aimed to establish whether PDGF-BB co-expression could also accelerate the stabilization of VEGF-induced vessels and, therefore, provide a safe and efficient strategy to achieve therapeutic angiogenesis within the short duration of expression afforded by adenoviruses. We assesed the stabilization time-course of vessels induced by myoblasts expressing heterogeneous VEGF levels, in the absence or presence of PDGF-BB, after 2 or 3 weeks of expression. We found that 50% of capillaries induced by VEGF and PDGF-BB co-expression were VEGF-independent already after 2 weeks and 90% after 3 weeks, compared to none after 2 weeks and only 30% after 3 weeks with VEGF alone. These data suggest that VEGF and PDGF co-expression from a single bicistronic construct represents a convenient strategy to induce persistent vessels within a short time of expression, with clear implications for therapeutic applications. Next we defined, for the first time, whether VEGF dose regulates the time-course of vascular stabilization and how PDGF-BB affects stabilization at different VEGF doses. Interestingly, we found that VEGF negatively regulates vascular stabilization in a dose-dependent fashion. In fact, normal capillaries induced by low VEGF levels stabilized faster than similarly normal vessels induced by higher doses at every time point considered. Aberrant vascular structures induced by very high VEGF levels never stabilized. Surprisingly, we found that PDGF-BB accelerated vascular stability only at medium and high VEGF levels, while it did not have significant effects on vessels induced by low VEGF doses. Mechanistically, we found that vascular stabilization is not simply dependent on the presence of pericytes, because normal capillaries induced by different doses of VEGF alone or with PDGF-BB were equally pericyte-covered but stabilized with different time-courses. Therefore, we investigated the regulation of several factors involved in vascular maturation in the different conditions. Intriguingly, we observed a correlation between the trend of expression of TGF-?1 and Sema3A and the trend of vascular stabilization at different VEGF and PDGF-BB doses. Sema3A has been recently described to promote vascular stabilization indirectly through the recruitment of a subset of neuropilin-1+ (NP1+)-CD11b+ bone marrow-derived cells. These cells are thought to exert their stabilizing effect by expressing pro-maturation factors, such as TGF-?1 and PDGF-BB. On the basis of results obtained, we tested whether VEGF and PDGF-BB co-expression from an adenoviral vector might induce safe and persistent angiogenesis in the short frame of expression allowed by this vector. Indeed, we found that PDFG-BB co-expression prevented the formation of aberrant vessels induced by Ad-VEGF and yielded only normal capillaries, when the two factors were expressed from a single bicistronic vector. Furthermore, in an immunocompetent model, in which adenoviral vectors are cleared within 10-14 days, we found that a proportion of vessels induced by VEGF and PDGF-BB co-expression had successfully stabilized and persisted after the cessation of VEGF expression. Based on this evidence, we conclude that VEGF and PDGF-BB co-expression provides a clinically relevant gene therapy approach for therapeutic angiogenesis

GIS for source water assessment and nonpoint source modeling in the Las Vegas Valley

This thesis develops a better understanding of issues related to surface water contamination and protection of drinking water sources in the Las Vegas Valley. A Geographic Information System (GIS) was used to identify source water protection zones and to estimate nonpoint source loads for the entire watershed; The extent of the source water protection zones is represented by the valley\u27s dry weather flows. After source water protection zones were defined, field work and GIS defined the potential contaminant sources and land uses within the protection zones; The GIS nonpoint source model shows that roads account for approximately 25% of the Total Nitrogen and 18% of the Total Phosphorus from nonpoint sources. Analysis suggest that a disproportionately high amount of nutrient loads have their origin within the source water protection zones. Approximately 10 to 7 percent of nutrient loads originate in the 5% of the total watershed area represented by protection zones

An Indirect Usage of the Qur’an in the XVth century. Jean Germain’s "Débat du chrétien et du sarrasin"

This paper focuses on an indirect use of the Qur’an in an inedited text, the "Débat du chrétien et du sarrasin". The "Débat" is a religious treatise written by the bishop Jean Germain (1396 ?-1461) for his patron Philip the Good of Burgundy. Although Germain claims that he relies on some “extraitz de l’Archorant”, he draws all his Qur’anic material from two intermediate texts: the Titulus V of Petrus Alfonsi’s "Dialogi contra Iudaeos" and Peter of Toledo’s "Epistula Sarraceni et Rescriptum Christiani", the Latin translation of the Arabic "Risālat al-Kindī". Through the analysis of Germain’s translation choices, this paper shows the attitude the author has towards his sources and brings out a still stereotyped image of Islam and its Prophet

Systematics and evolution of Leandra s.str. (Melastomataceae, Miconieae)

Phylogenetic studies in the Melastomataceae have demonstrated the need of taxonomic rearrangements in the current classification. Melastomes are among the most diverse groups of plants and several cases of known artificial taxa are observed and awaiting further resolution. One example is the Leandra s.str. clade, which includes the majority of the taxa traditionally treated in the genus Leandra. Some attempts have been made to infer the relationships of Leandra s.str., but the sampling in these earlier studies was sparse and the resolution low inside the clade. The main objective here is to propose a comprehensive phylogenetic framework for this group to address evolutionary questions regarding morphology and biogeography. In Chapter 1, using a species tree approach, I present a phylogenetic hypothesis for Leandra s.str. and discuss incongruent patterns across gene trees and putative processes leading to them. The genus Leandra has been scarcely studied since a review in the 19th Century, and information such as overall distribution, anatomy, cytology, morphology, and even taxonomy is very limited. In Chapter 2, chromosome counts for some species of Leandra s.str. are provided, while in Chapter 6 a taxonomic review of Leandra sect. Leandra is presented and driven by the phylogenetic hypothesis of Chapter 1. The diversity and evolution of flowers in the Leandra s.str. clade is the topic of Chapter 3. Several question regarding the evolution of floral traits are addressed on a continuous framework using comparative phylogenetic methods. Leandra s.str. is nearly restricted to eastern Brazil, and the biogeography of the group is discussed in Chapters 4 and 5. In the former, I investigate disjunct patterns and distributional ranges and their relationship with climatic variables, focusing in the species that occurs outside eastern Brazil. In Chapter 5, I reconstruct the historical biogeography of Leandra s.str., proposing discrete biogeographical areas for ancestral distribution estimation, explore the climatic evolution and discuss the role of sympatry/allopatry in this group

Preliminary studies on accelerator development program

A study was made of the Abramyan type accelerator using a scale model to investigate the resonant transformer principle and the beam induced voltages. The Abramyan technique of resonant transformer charging an accelerating gap was found to work very well. The circuit is quite simple, the components values are not critical, and only a low voltage primary capacitor and a single switch are needed to generate a high secondary voltage. (PMA

Proposição do grupo Ictericus em Euschistus (Euschistus) : revisão de espécies neárticas, com duas sinonímias

Pentatomidae são encontrados em todas as regiões zoogeográficas. É a quarta maior família da subordem Heteroptera, sendo distribuída em dez subfamílias, representadas por aproximadamente 4700 espécies e 800 gêneros, tendo sua maior diversidade nas regiões tropicais e subtropicais. Pentatominae é a subfamília mais diversa entre os pentatomídeos, e sua maior tribo, Carpocorini, reúne diversas espécies prejudiciais à agricultura. Euschistus Dallas, 1851 é o maior gênero desta tribo, e sua distribuição é restrita às Américas. Algumas espécies deste gênero possuem importância econômica tanto na América do Norte quanto na do Sul. No Brasil, a principal praga agrícola do gênero é E. heros (Fabricius, 1798), enquanto nos Estados Unidos são E. servus (Say, 1832), E. tristigmus (Say, 1832) e E. variolarius (Palisot de Beauvois, 1817). Com 67 espécies, Euschistus é dividido em três subgêneros: o nominal, Lycipta e Euschistomorphus. O subgênero nominal agrupa 54 espécies e é o maior do gênero. Poucas hipóteses filogenéticas foram propostas para o relacionamento destas espécies. Na ausência de análises filogenéticas em nível específico, alguns agrupamentos utilizando características morfológicas externas, mas principalmente de genitália masculina são tidas como hipóteses válidas de relações entre espécies. A redescrição e revisão taxonômica de espécies é crucial para um melhor entendimento nas proposições das unidades taxonômicas válidas. Descrições simplistas dificultam o reconhecimento preciso das espécies, e trabalhos revisivos são úteis para elucidação taxonômica, isto se torna mais importante no caso de insetos com importância econômica. Um dos agrupamentos sistemáticos dentro de Euschistus foi proposto por Stål, e relaciona cinco táxons baseados em similaridades morfológicas e localidade geográfica: E. ictericus (Linnaeus, 1763), E. variolarius (Palisot de Beauvois, 1817) E. servus servus (Say, 1832), E. servus euschistoides (Vollenhoven, 1868), E. tristigmus tristigmus (Say, 1832). Adicionalmente, nós incluímos a subespécie válida E. tristigmus luridus (Dallas, 1851), E. inflatus Van Duzee, 1903, e E. latimarginatus Zimmer, 1910. Neste trabalho estas espécies são redescritas, com inclusão de caracteres de genitália feminina interna e externa. No que se refere às subespécies, as variações de populações e regiões de simpatria levou-nos a propor as sinonímias das subespécies E. servus euschistoides com E. servus servus e de E. tristigmus luridus com E. tristigmus tristigmus. Euschistus tristigmus não seguiu o padrão morfológico das demais espécies do grupo, tendo acentuadas distinções em caracteres de pigóforo, parâmeros, phallus, genitália interna feminina. Neste trabalho é proposto uma descrição formal do grupo ictericus, com cinco espécies, e são fornecidas fotografias e ilustrações das espécies do grupo, bem como novos caracteres de genitália interna feminina, que podem agregar conhecimento em futuros trabalhos filogenéticos.Pentatomidae are found in all zoogeographic regions. It is the fourth largest family of the suborder Heteroptera, distributed within ten subfamilies, represented by approximately 4700 species and 800 genera, being more diverse in tropical and subtropical regions. Pentatominae is the most speciose subfamily among the pentatomids, and its largest tribe, Carpocorini groups several species harmful to agriculture. Euschistus Dallas, 1851 is the largest genus of this tribe, and is restricted to the Americas. Some species of the genus are important to the economy both in North and South America. In Brazil, the primary agricultural pest of the genus is E. heros (Fabricius, 1798), while in the United States, E. servus (Say, 1832), E. tristigmus (Say, 1832) and E. variolarius (Palisot de Beauvois, 1817). With 67 species, Euschistus is divided into three subgenera: the nominal, Lycipta and Euschistomorphus. The nominal subgenus groups 54 species and is the largest of the genera. Few phylogenetic hypotheses have been proposed for the relationship of these species. In the absence of phylogenetic analysis at species level, some groupings using external morphological characteristics, mainly male genitalia, are considered valid hypotheses of relationships between species. The redescription and taxonomic revision of species is crucial for a better understanding of the propositions of valid taxonomic units. Simplistic descriptions hinder the precise recognition of species, and revision papers are useful for taxonomic enlightenment. It becomes more important for insects with economic importance. One of the systematic groupings within Euschistus was proposed by Stål, and groups five taxa based on morphological similarities and geographical location: E. ictericus (Linnaeus, 1763), E. variolarius (Palisot de Beauvois, 1817) E. servus servus (Say, 1832), E. servus euschistoides (Vollenhoven, 1868), E. tristigmus tristigmus (Say, 1832). Additionally, we include the valid subspecies E. tristigmus luridus (Dallas, 1851), E. inflatus Van Duzee, 1903, and E. latimarginatus Zimmer, 1910. In this work, these species are redescribed, including the description of internal and external female genitalia. Regarding the subspecies, variations in populations, and regions of sympatry led us to propose the synonymies of the subspecies E. servus euschistoides as a junior synonym of E. servus servus and E. tristigmus luridus of E. tristigmus tristigmus. Euschistus tristigmus did not follow the morphological pattern of the other species of the group, presenting distinctions in characters of pygophore, parameres, phallus, and female internal genitalia. This work is proposed a formal description of ictericus group, including five species, and furnishes photographs and illustrations of the species of the group, as well as new characters of female internal genitalia, which can add knowledge in future phylogenetic works