Diversity among satellite glial cells in dorsal root ganglia of the rat

Peripheral glial cells consist of satellite, enteric glial, and Schwann cells. In dorsal root ganglia, besides pseudo-unipolar neurons, myelinated and nonmyelinated fibers, macrophages, and fibroblasts, satellite cells also constitute the resident components. Information on satellite cells is not abundant; however, they appear to provide mechanical and metabolic support for neurons by forming an envelope surrounding their cell bodies. Although there is a heterogeneous population of neurons in the dorsal root ganglia, satellite cells have been described to be a homogeneous group of perineuronal cells. Our objective was to characterize the ultrastructure, immunohistochemistry, and histochemistry of the satellite cells of the dorsal root ganglia of 17 adult 3-4-month-old Wistar rats of both genders. Ultrastructurally, the nuclei of some satellite cells are heterochromatic, whereas others are euchromatic, which may result from different amounts of nuclear activity. We observed positive immunoreactivity for S-100 and vimentin in the cytoplasm of satellite cells. The intensity of S-100 protein varied according to the size of the enveloped neuron. We also noted that vimentin expression assumed a ring-like pattern and was preferentially located in the cytoplasm around the areas stained for S-100. In addition, we observed nitric oxide synthase-positive small-sized neurons and negative large-sized neurons equal to that described in the literature. Satellite cells were also positive for NADPH-diaphorase, particularly those associated with small-sized neurons. We conclude that all satellite cells are not identical as previously thought because they have different patterns of glial marker expression and these differences may be correlated with the size and function of the neuron they envelope.

Differential gene expression profiles of hepatocellular carcinomas associated or not with viral infection

Chronic hepatitis B (HBV) and C (HCV) virus infections are the most important factors associated with hepatocellular carcinoma (HCC), but tumor prognosis remains poor due to the lack of diagnostic biomarkers. In order to identify novel diagnostic markers and therapeutic targets, the gene expression profile associated with viral and non-viral HCC was assessed in 9 tumor samples by oligo-microarrays. The differentially expressed genes were examined using a z-score and KEGG pathway for the search of ontological biological processes. We selected a non-redundant set of 15 genes with the lowest P value for clustering samples into three groups using the non-supervised algorithm k-means. Fisher’s linear discriminant analysis was then applied in an exhaustive search of trios of genes that could be used to build classifiers for class distinction. Different transcriptional levels of genes were identified in HCC of different etiologies and from different HCC samples. When comparing HBV-HCC vs HCV-HCC, HBV-HCC/HCV-HCC vs non-viral (NV)-HCC, HBC-HCC vs NV-HCC, and HCV-HCC vs NV-HCC of the 58 non-redundant differentially expressed genes, only 6 genes (IKBKβ, CREBBP, WNT10B, PRDX6, ITGAV, and IFNAR1) were found to be associated with hepatic carcinogenesis. By combining trios, classifiers could be generated, which correctly classified 100% of the samples. This expression profiling may provide a useful tool for research into the pathophysiology of HCC. A detailed understanding of how these distinct genes are involved in molecular pathways is of fundamental importance to the development of effective HCC chemoprevention and treatment.

Implications of infectious diseases and the adrenal hypothesis for the etiology of childhood acute lymphoblastic leukemia

Acute leukemia is the most frequent cancer in children. Recently, a new hypothesis was proposed for the pathogenesis of childhood acute lymphoblastic leukemia (ALL). The so-called "adrenal hypothesis" emphasized the role of endogenous cortisol in the etiology of B-cell precursor ALL. The incidence peak of ALL in children between 3 to 5 years of age has been well documented and is consistent with this view. The adrenal hypothesis proposes that the risk of childhood B-cell precursor ALL is reduced when early childhood infections induce qualitative and quantitative changes in the hypothalamus-pituitary-adrenal axis. It suggests that the increased plasma cortisol levels would be sufficient to eliminate all clonal leukemic cells originating during fetal life. Because Brazil is a continental and tropical country, the exposure to infections is diversified with endemic viral and regionally non-viral infections, with some characteristics that support the recent adrenal hypothesis. Here we discuss this new hypothesis in terms of data from epidemiological studies and the possible implications of the diversity of infections occurring in Brazilian children.

Diversity of 16S rRNA genes from bacteria of sugarcane rhizosphere soil

Sugarcane is an important agricultural product of Brazil, with a total production of more than 500 million tons. Knowledge of the bacterial community associated with agricultural crops and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. However, most studies aim to isolate endophytic or rhizosphere bacteria associated with the plant by culture-dependent approaches. Culture-independent approaches allow a more comprehensive view of entire bacterial communities in the environment. In the present study, we have used this approach to assess the bacterial community in the rhizosphere soil of sugarcane at different times and under different nitrogen fertilization conditions. At the high taxonomic level, few differences between samples were observed, with the phylum Proteobacteria (29.6%) predominating, followed by Acidobacteria (23.4%), Bacteroidetes (12.1%), Firmicutes (10.2%), and Actinobacteria (5.6%). The exception was the Verrucomicrobia phylum whose prevalence in N-fertilized soils was approximately 0.7% and increased to 5.2% in the non-fertilized soil, suggesting that this group may be an indicator of nitrogen availability in soils. However, at low taxonomic levels a higher diversity was found associated with plants receiving nitrogen fertilizer. Bacillus was the most predominant genus, accounting for 19.7% of all genera observed. Classically reported nitrogen-fixing and/or plant growth-promoting bacterial genera, such as Azospirillum, Rhizobium, Mesorhizobium, Bradyrhizobium, and Burkholderia were also found although at a lower prevalence.

Coping with genetic diversity: the contribution of pathogen and human genomics to modern vaccinology

Vaccine development faces major difficulties partly because of genetic variation in both infectious organisms and humans. This causes antigenic variation in infectious agents and a high interindividual variability in the human response to the vaccine. The exponential growth of genome sequence information has induced a shift from conventional culture-based to genome-based vaccinology, and allows the tackling of challenges in vaccine development due to pathogen genetic variability. Additionally, recent advances in immunogenetics and genomics should help in the understanding of the influence of genetic factors on the interindividual and interpopulation variations in immune responses to vaccines, and could be useful for developing new vaccine strategies. Accumulating results provide evidence for the existence of a number of genes involved in protective immune responses that are induced either by natural infections or vaccines. Variation in immune responses could be viewed as the result of a perturbation of gene networks; this should help in understanding how a particular polymorphism or a combination thereof could affect protective immune responses. Here we will present: i) the first genome-based vaccines that served as proof of concept, and that provided new critical insights into vaccine development strategies; ii) an overview of genetic predisposition in infectious diseases and genetic control in responses to vaccines; iii) population genetic differences that are a rationale behind group-targeted vaccines; iv) an outlook for genetic control in infectious diseases, with special emphasis on the concept of molecular networks that will provide a structure to the huge amount of genomic data.

Assessing the diversity of the virulence potential ofEscherichia coli isolated from bacteremia in São Paulo, Brazil

Most of the knowledge of the virulence determinants of extraintestinal pathogenicEscherichia coli (ExPEC) comes from studies with human strains causing urinary tract infections and neonatal meningitis and animal strains causing avian colibacillosis. In this research, we analyzed the phylogenetic background, the presence of 20 ExPEC virulence factors, and the intrinsic virulence potential of 74 E. coli strains isolated in São Paulo, Brazil, from 74 hospitalized patients (43 males and 31 females) with unknown-source bacteremia. Unlike other places in the world, the bacteremic strains originated equally from phylogroups B2 (35%) and D (30%). A great variability in the profiles of virulence factors was noted in this survey. Nevertheless, 61% of the strains were classified as ExPEC, meaning that they possessed intrinsic virulent potential. Accordingly, these strains presented high virulence factor scores (average of 8.7), and were positively associated with 12 of 17 virulence factors detected. On the contrary, the non-ExPEC strains, isolated from 39% of the patients, presented a generally low virulence capacity (medium virulence factor score of 3.1), and were positively associated with only the colicin cvaC gene. These results show the importance of discriminating E. coli isolates that possess characteristics of true pathogens from those that may be merely opportunistic in order to better understand the virulence mechanisms involved in extraintestinalE. coli infections. Such knowledge is essential for epidemiological purposes as well as for development of control measures aimed to minimize the incidence of these life-threatening and costly infections.

Sequence analysis of the 5′ third of glycoprotein C gene of South American bovine herpesviruses 1 and 5

Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) share high genetic and antigenic similarities, but exhibit marked differences in tissue tropism and neurovirulence. The amino-terminal region of glycoprotein C (gC), which is markedly different in each of the viruses, is involved in virus binding to cellular receptors and in interactions with the immune system. This study investigated the genetic and antigenic differences of the 5′ region of the gC (5′ gC) gene (amino-terminal) of South American BoHV-1 (n=19) and BoHV-5 (n=25) isolates. Sequence alignments of 374 nucleotides (104 amino acids) revealed mean similarity levels of 97.3 and 94.2% among BoHV-1 gC (gC1), respectively, 96.8 and 95.6% among BoHV-5 gC (gC5), and 62 and 53.3% between gC1 and gC5. Differences included the absence of 40 amino acid residues (27 encompassing predicted linear epitopes) scattered throughout 5′ gC1 compared to 5′ gC5. Virus neutralizing assays testing BoHV-1 and BoHV-5 antisera against each isolate revealed a high degree of cross-neutralization between the viruses, yet some isolates were neutralized at very low titers by heterologous sera, and a few BoHV-5 isolates reacted weakly with either sera. The virus neutralization differences observed within the same viral species, and more pronounced between BoHV-1 and BoHV-5, likely reflect sequence differences in neutralizing epitopes. These results demonstrate that the 5′ gC region is well conserved within each viral species but is divergent between BoHV-1 and BoHV-5, likely contributing to their biological and antigenic differences.

Digital content and making it viral in social media

Tutkimuksen tavoite on selvittää digitaalisen sisällön ominaisuuksia, jotka vaikuttavat ryhtyvätkö kuluttajat jakamaan, tykkäämään ja kommentoimaan sitä sosiaalisessa mediassa. Tällä pyritään auttamaan yrityksiä ymmärtämään paremmin viraalisuutta, jotta he pystyisivät tuottamaan ja julkaisemaan nettisivuillaan ja sosiaalisessa mediassa parempaa sisältöä, jota kuluttajat jakaisivat enemmän. Tutkimus toteutetaan muodostamalla hypoteeseja mahdollisista ominaisuuksista kirjallisuuden perusteella ja testaamalla niitä regressioanalyyseillä empiirisessä osiossa. Tulokset paljastavat yhdeksän piirrettä, jotka lisäävät viraalisuutta: kiinnostavuus, neutraalisuus, yllättävyys, viihdyttävyys, epäkäytännöllisyys, artikkelin ja Facebook julkaisun pituus, eri sisältö taktiikoiden käyttö (erityisesti blogit ja kuvat lisäävät viraalisuutta) sekä kun mielipidevaikuttaja tai kuuluisuus jakaa sisällön.

Genetic diversity and phenotypic variability of phytoplankton populations in the Baltic Sea

En av naturens mest grundläggande aspekter är den enorma mängd av variation som existerar mellan arter. Denna variation har lett oss till att klassificera olika organismer på basis av morfologiska skillnader och på senare tid till att jämföra genetiska skillnader på individens nivå. Den marina kiselalgen Skeletonema marinoi är en av de vanligaste växtplanktonarter i Östersjön under vårblomningen och anses viktig för den årliga produktionen. En av mina främsta målsättningar var att beskriva den intra-specifika diversiteten hos denna art längs med miljögradienter i Östersjön. Ett annat mål var att klargöra de faktorer som eventuellt är involverade i konfigurationen av genetisk diversitet och differentiering. Med hjälp av genetiska markörer visade jag att den genetiska diversiteten hos S. marinoi populationer i Östersjön är lägre jämfört med populationer i östra delen av Nordsjön. Arten är genetiskt uppdelad så att en utpräglad population förekommer i Östersjön och en annan, genetiskt åtskild population förekommer norr om de Danska sunden. Resultaten visar att de genetiskt åtskilda populationerna är anpassade till lokala salinitetsförhållanden. Genflödet mellan populationerna korrelerade kraftigt med havströmmar i området. Mina studier avslöjade även omfattande variation av fenotypiska, ekologiskt vikitga särdrag hos olika kloner. Djurplankton som äter kiselalger kunde modifiera den klonala mångfalden av fenotypiskt variabla S. marinoi populationer. En ökad klonal mångfald ledde till högre prestationsförmåga i fråga om primär produktion och stabiliserade ekofysiologiska funktioner. Som visas i denna avhandling består en art allt som oftast av åtskilliga genetiska varianter med fenotypiska skillnader. Kunskap om sådana intra-specifika skillnader är en förutsättning för att vi skall kunna förstå var och varför arter förekommer. Denna kunskap utgör även en grund för prognoser som siktar på att förutspå huruvida arter kan anpassa sig till framtida miljöförhållanden. ------------------------------------------------------ Suunnaton määrä variaatioita eliölajien välillä on perustavanlaatuinen ominaisuus luonnossa. Perinteisesti tätä monimuotoisuutta on käytetty organismien luokittelemiseen eri lajeihin niiden morfologisten eroavaisuuksien perusteella. Hiljattain myös geneettisten erojen huomioimista yksilötasolla on hyödynnetty lajien luokittelemisessa. Merialueilla esiintyvä piilevä, Skeletonema marinoi on yksi Itämeren tavallisimmista kasviplanktonlajeista kevätkukinnan aikana. Tavoitteenani oli selventää geneettistä ja fenotyyppistä monimuotoisuutta pitkin Itämeren ympäristögradienttejä. Geneettisen monimuotoisuuteen ja erkaantumiseen vaikuttavien tekijöiden selvittäminen oli tärkeä aspekti väitöstutkimuksessani. Geneettisiä markkereita käyttämällä pystyin toteamaan, että S. marinoi levän geneettinen monimuotoisuus on Itämeressä merkittävästi alhaisempi kuin läheisessä Pohjanmeren itäosassa. Tutkittu laji jakautuu geneettisesti yhteen erilliseen populaatioon Itämeressä ja toiseen selvästi erottuvaan populaatioon Tanskan salmien pohjoispuolella. Kokeellisten tulosten perusteella nämä geneettisesti erilaistuneet populaatiot ovat kumpikin sopeutuneet paikalliseen veden suolapitoisuuteen. Populaatioiden välisen geenivirran ja merivirtojen luoman yhteyden välillä havaittiin vahva korrelaatio. Tutkimukseni paljastivat myös laajaa vaihtelua Skeletonema-kloonien ekologisesti tärkeissä ominaisuuksissa. Kokeellisten tutkimusteni perusteella laiduntajat pystyivät muuttamaan geneettisten kloonien lukumäärää monimuotoisissa S. marinoi populaatioissa. Lisääntynyt kloonien lukumäärä paransi perustuotantokykyä ja vakautti ekofysiologisia toimintoja. Kuten tässä väitöstutkimuksessa osoitetaan, lajit koostuvat useimmiten lukuisista geneettisistä muunnelmista, jotka eroavat usein fenotyypeiltään. Ymmärtääksemme missä tietyt lajit esiintyvät ja miksi, tarvitsemme tietoa lajien sisäisistä vaihteluista. Tämä tieto on tarpeellista, jotta voimme ennustaa lajien sopeutumista tuleviin ympäristönmuutoksiin.

Making home rules for mother tongues : the legal implications of linguistic diversity in the design of autonomy regimes

Principen om nationalismen där det politiska och det nationella är samspelt kan vara av markant betydelse för uppbyggande av autonomiska regimer. Likaså tillåter decentralicering och delegering av befogenheter för språk och utbildning (officiellt erkännande av språk, standardisering av språk, undervisningsspråk och relaterade läroplaner) formning av identiteter inom dessa autonomiska regimer. Resultatet är en ofullkomlig cirkulär relation där språk, samfund och politiska institutioner ömsesidigt och kontinuerligt formar varandra: lingvistiskt mångfald prägar och formger autonomiska ordningar och vice-versa. De juridiska implikationerna av territoriella och icke-territoriella former av autonomi är dock av en annan art. Emedan territoriell autonomi bygger på idéen om ett eventuellt inkluderande hemland för lingvistiska grupper, vars vistelseort är avgörande, förstärker den icke-territoriella autonomin idéen om ett exclusivt samfund bestående av själv-identifierade medlemmar som är kapabla till självstyre oavsett territoriella gränser. Denna avhandling utgör an analys av sådana juridiska implikationer genom komparativa och institutionella analyser. Avhandlingen föreslår som resultat en serie av normativa och pragmatiska rekommendationer inriktade på att främja demokratiseringsprocesser i linje med principer om multikulturalism.

Genetic diversity and comparison of physicochemical and nutritional characteristics of six quinoa (Chenopodium quinoa willd.) genotypes cultivated in Chile

The present study was focused on the analysis of agronomical, nutritional, physicochemical, and antioxidant properties of six genetically different quinoa (Chenopodium quinoa Willd) genotypes cultivated in three distinctive geographical zones of Chile. Ancovinto and Cancosa genotypes from the northern Altiplano (19 ºS), Cáhuil and Faro from the central region (34 ºS), and Regalona and Villarica from the southern region (39 ºS) are representative of high genetic differentiation among the pooled samples, in particular between Altiplano and the central-southern groups. A Common-Garden Assay at 30 ºS showed significant differences among seed origins in all morphometric parameters and also in yields. Altiplano genotypes had larger panicule length but no seed production. A significant influence of the different quinoa genotypes on chemical composition and functional properties was also observed. Protein concentration ranged from 11.13 to 16.18 g.100 g-1 d.m., while total dietary fiber content ranged from 8.07-12.08 g.100 g-1 d.m., and both were the highest in Villarrica ecotype. An adequate balance of essential amino acids was also observed. Sucrose was the predominant sugar in all genotypes. Antioxidant activity was high in all genotypes, and it was highest in Faro genotype (79.58% inhibition).

Monooxygenase Diversity and Oxygen Activation within Polyketide Antibiotic Biosynthesis

Molecular oxygen (O2) is a key component in cellular respiration and aerobic life. Through the redox potential of O2, the amount of free energy available to organisms that utilize it is greatly increased. Yet, due to the nature of the O2 electron configuration, it is non-reactive to most organic molecules in the ground state. For O2 to react with most organic compounds it must be activated. By activating O2, oxygenases can catalyze reactions involving oxygen incorporation into organic compounds. The oxygen activation mechanisms employed by many oxygenases to have been studied, and they often include transition metals and selected organic compounds. Despite the diversity of mechanisms for O2 activation explored in this thesis, all of the monooxygenases studied in the experimental part activate O2 through a transient carbanion intermediate. One of these enzymes is the small cofactorless monooxygenase SnoaB. Cofactorless monooxygenases are unusual oxygenases that require neither transition metals nor cofactors to activate oxygen. Based on our biochemical characterization and the crystal structure of this enzyme, the mechanism most likely employed by SnoaB relies on a carbanion intermediate to activate oxygen, which is consistent with the proposed substrate-assisted mechanism for this family of enzymes. From the studies conducted on the two-component system AlnT and AlnH, both the functions of the NADH-dependent flavin reductase, AlnH, and the reduced flavin dependent monooxygenase, AlnT, were confirmed. The unusual regiochemistry proposed for AlnT was also confirmed on the basis of the structure of a reaction product. The mechanism of AlnT, as with other flavin-dependent monooxygenases, is likely to involve a caged radical pair consisting of a superoxide anion and a neutral flavin radical formed from an initial carbanion intermediate. In the studies concerning the engineering of the S-adenosyl-L-methionine (SAM) dependent 4-O-methylase DnrK and the homologous atypical 10-hydroxylase RdmB, our data suggest that an initial decarboxylation of the substrate is catalyzed by both of these enzymes, which results in the generation of a carbanion intermediate. This intermediate is not essential for the 4-O-methylation reaction, but it is important for the 10-hydroxylation reaction, since it enables substrate-assisted activation of molecular oxygen involving a single electron transfer to O2 from a carbanion intermediate. The only role for SAM in the hydroxylation reaction is likely to be stabilization of the carbanion through the positive charge of the cofactor. Based on the DnrK variant crystal structure and the characterizations of several DnrK variants, the insertion of a single amino acid in DnrK (S297) is sufficient for gaining a hydroxylation function, which is likely caused by carbanion stabilization through active site solvent restriction. Despite large differences in the three-dimensional structures of the oxygenases and the potential for multiple oxygen activation mechanisms, all the enzymes in my studies rely on carbanion intermediates to activate oxygen from either flavins or their substrates. This thesis provides interesting examples of divergent evolution and the prevalence of carbanion intermediates within polyketide biosynthesis. This mechanism appears to be recurrent in aromatic polyketide biosynthesis and may reflect the acidic nature of these compounds, propensity towards hydrogen bonding and their ability to delocalize π-electrons.

Diversity in the fitness industry : a cross-case comparison /

This cross-case study explored the extent to which two fitness facilities were accommodating diversity with respect to age, ethnicity, gender, social class, sex-role socialization, and persons with a disability among both members and staflf. The sites were purposely chosen in a large city and a smaller city in order to provide as representative an example as possible of health clubs within a small sample population. The interview participants were selected by a combination of stratified, typical case, and snowball sampling strategies. . , .. , The intent of the exploration was a two-fold examination of diversity issues within both the membership and the staff of the organization. Data were collected and analysis was done using a triangulation method involving personal interviews, observations, and facility documentation. The results ofthe study showed that the members and staff at each facility were rather homogeneous in ethnicity, age, social class, physical ability, and physical appearance. From a membership standpoint, the environment of the sites presented the impression of being affordable only to the middle- and upper-middle classes, unwelcoming to the older, less fit, or overweight participant, economically exclusive for youth, and nonaccommodating for people with a disability. With respect to staff, the findings indicated that the fitness facilities purported to be team-oriented in theory, but were hierarchical in practice, with the major decision making being made by the male executives. The paper concludes with the recommendation that students must be given a practical toolkit for dealing with these issues in their postsecondary courses.