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1

Lipid composition and effect of amphotericin B on yeast cells of Paracoccidioides brasiliensis  

Microsoft Academic Search

Yeast cells of Paracoccidioides brasiliensis strain SN, were obtained for analysis of lipid composition. Total lipids, phospholipids, sterols, and qualitative sterols and fatty acid composition were determined. Such analysis were made on cells cultured in the presence or absence of amphotericin B and on non proliferating cell suspensions exposed to the antibiotic. Marked alterations in lipid contents were observed in

Júnia Scares Hamdan; Maria Aparecida Resende

1988-01-01

2

Biochemical differentiation of mycelium and yeast forms of Paracoccidioides brasiliensis by Fourier transform infrared spectroscopy  

NASA Astrophysics Data System (ADS)

Paracoccidioides brasiliensis the etiological agent of paracoccidioidomycosis, is a dimorphic fungus existing as mycelia in the environment (or at 25 °C in vitro) and as yeast cells in the human host (or at 37°C in vitro). The most prominent difference between both forms is probably the cell wall polysaccharide, being 1,3-?-glucan usually found in mycelia and 1,3-?-glucan found in yeasts, but a plethora of other differences have already been described. In this work, we performed a Fourier Transform Infrared Spectroscopy analysis to compare the yeast and mycelia forms of P. brasiliensis and found additional biochemical differences. The analysis of the spectra showed that differences were distributed in chemical bonds of proteins, lipids and carbohydrates.

Castilho, Maiara L.; Campos, Claudia B. L.; Matos, Tatiana G. F.; de Abreu, Geraldo M. A.; Martin, Airton A.; Raniero, Leandro

2012-02-01

3

Bioinformatics of the Paracoccidioides brasiliensis EST Project  

Microsoft Academic Search

Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, an endemic mycosis of Latin America. This fungus presents a dimorphic character; it grows as a mycelium at room temperature, but it is isolated as yeast from infected individuals. It is believed that the transition from mycelium to yeast is important for the infective process. The Functional and Differential Genome of Paracoc-

Marcelo M. Brígido; Maria Emília; M. T. Walter; Adilton G. Oliveira; Marcus K. Inoue; Daniel S. Anjos; Edans F. O. Sandes; João J. Gondim; Maria José de A. Carvalho; Nalvo F. Almeida Jr; Maria Sueli Soares Felipe

2005-01-01

4

Transcriptome Analysis of Paracoccidioides brasiliensis Cells Undergoing Mycelium-to-Yeast Transition  

PubMed Central

Paracoccidioides brasiliensis is a thermodimorphic fungus associated with paracoccidioidomycosis (PCM), a systemic mycosis prevalent in South America. In humans, infection starts by inhalation of fungal propagules, which reach the pulmonary epithelium and transform into the yeast parasitic form. Thus, the mycelium-to-yeast transition is of particular interest because conversion to yeast is essential for infection. We have used a P. brasiliensis biochip carrying sequences of 4,692 genes from this fungus to monitor gene expression at several time points of the mycelium-to-yeast morphological shift (from 5 to 120 h). The results revealed a total of 2,583 genes that displayed statistically significant modulation in at least one experimental time point. Among the identified gene homologues, some encoded enzymes involved in amino acid catabolism, signal transduction, protein synthesis, cell wall metabolism, genome structure, oxidative stress response, growth control, and development. The expression pattern of 20 genes was independently verified by real-time reverse transcription-PCR, revealing a high degree of correlation between the data obtained with the two methodologies. One gene, encoding 4-hydroxyl-phenyl pyruvate dioxygenase (4-HPPD), was highly overexpressed during the mycelium-to-yeast differentiation, and the use of NTBC [2-(2-nitro-4-trifluoromethylbenzoyl)-cyclohexane-1,3-dione], a specific inhibitor of 4-HPPD activity, as well as that of NTBC derivatives, was able to inhibit growth and differentiation of the pathogenic yeast phase of the fungus in vitro. These data set the stage for further studies involving NTBC and its derivatives as new chemotherapeutic agents against PCM and confirm the potential of array-based approaches to identify new targets for the development of alternative treatments against pathogenic microorganisms.

Nunes, Luiz R.; Costa de Oliveira, Regina; Leite, Daniela Batista; da Silva, Vivian Schmidt; dos Reis Marques, Everaldo; da Silva Ferreira, Marcia Eliana; Ribeiro, Diogenes Custodio Duarte; de Souza Bernardes, Luciano Angelo; Goldman, Maria Helena S.; Puccia, Rosana; Travassos, Luiz R.; Batista, Wagner L.; Nobrega, Marina Pasetto; Nobrega, Francisco G.; Yang, Ding-Yah; de Braganca Pereira, Carlos A.; Goldman, Gustavo H.

2005-01-01

5

Evidence for the Role of Calcineurin in Morphogenesis and Calcium Homeostasis during Mycelium-to-Yeast Dimorphism of Paracoccidioides brasiliensis  

Microsoft Academic Search

Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, the most prevalent human deep mycosis in Latin America. The dimorphic transition from mycelium to yeast (M-Y) is triggered by a temperature shift from 25°C to 37°C and is critical for pathogenicity. Intracellular Ca2 levels increased in hyphae immediately after temperature-induced dimorphism. The chelation of Ca2 with extracellular (EGTA) or intracellular

Claudia B. L. Campos; J. P. T. Di Benedette; F. V. Morais; R. Ovalle; M. P. Nobrega

2008-01-01

6

Characteristics of 17 Paracoccidioides brasiliensis isolates  

Microsoft Academic Search

We have studied the physiological and morphological features of 17 isolates ofParacoccidioides brasiliensis in order to define their phenotypes. The isolates were cultured at room temperature on potato dextrose agar (PDA, Difco)\\u000a slants for mycelial growth and in 1% dextrose brain heart infusion agar (BHIA, Difco) at 37°C for the study of yeast forms.\\u000a Most mycelial and yeast forms grew

Ayako Sano; Reiko Tanaka; Kazuko Nishimura; Cilmery S. Kurokawa; Kunie labuki R. Coelho; Marcello Franco; Mario Rubens Montenegro; Makoto Miyaji

1997-01-01

7

Comparison of transcription of multiple genes during mycelia transition to yeast cells of Paracoccidioides brasiliensis reveals insights to fungal differentiation and pathogenesis  

Microsoft Academic Search

The ascomycete Paracoccidioides brasiliensis is a human pathogen with a broad distribution in Latin America. The infection process of P. brasiliensis is initiated by aerially dispersed mycelia propagules, which differentiate into the yeast parasitic phase in human lungs.\\u000a Therefore, the transition to yeast is an initial and fundamental step in the infective process. In order to identify and characterize\\u000a genes

Juliana Alves Parente; Clayton Luiz Borges; Alexandre Melo Bailão; Maria Sueli S. Felipe; Maristela Pereira; Célia Maria de Almeida Soares

2008-01-01

8

Morphological Transition of Paracoccidioides brasiliensis Conidia to Yeast Cells: In Vivo Inhibition in Females  

PubMed Central

Clinical paracoccidioidomycosis is 13 times more common in men than in women. Estrogen inhibits the transition of mycelia or conidia (the saprophytic form of Paracoccidoides brasiliensis) to yeasts (the parasitic form) in vitro. Here, we show that, in male mice that were infected intranasally (mimicking natural infection) the transition of conidia in bronchoalveolar lavage fluids to intermediate forms and yeasts occurred over 24 to 96 h; CFU and yeasts (shown by histopathology) increased subsequently. In females, transition did not occur and infection cleared. These events in vivo are consistent with epidemiological and in vitro observations, suggesting that female hormones block transition and are responsible for resistance.

Aristizabal, Beatriz H.; Clemons, Karl V.; Stevens, David A.; Restrepo, Angela

1998-01-01

9

Ultrastructure of Dimorphic Transformation in Paracoccidioides brasiliensis  

PubMed Central

The fine structure of Paracoccidioides brasiliensis undergoing temperature-dependent transformation from mycelium to yeast and vice versa (M ? Y) was studied. The transitional form to mycelium from the yeast appears as an elongated bud that extends from the yeast and which has a mixture of characteristics from both the yeast and the mycelium. The transitional form to yeast from the mycelium starts with enlargement of the interseptal spaces and cracking of the outer electron-dense layer of the cell wall of the hypha. Later the interseptal spaces tend to become round and separate. In M ? Y only few interseptal spaces seem to transform. The yeast is produced by self-transformation of the hypha. In Y ? M a new structure is formed and the yeast dies. Intrahyphal hyphae are observed during the transformation from M ? Y, and intrayeast hyphae during the Y ? M. Due to the high mortality and breakage observed in both types of transformations, we believe that wound of the yeast or the mycelium could elicit this phenomenon. Images

Carbonell, Luis M.

1969-01-01

10

Primers for Clinical Detection of Paracoccidioides brasiliensis  

PubMed Central

From a 0.72-kb fragment universally generated in Paracoccidioides brasiliensis strains, primers were designed and tested on genomic DNA of this and other pathogenic fungi. They were specific and highly sensitive for P. brasiliensis DNA. Positive results were obtained when these were tested in clinical samples.

San-Blas, Gioconda; Nino-Vega, Gustavo; Barreto, Laura; Hebeler-Barbosa, Flavia; Bagagli, Eduardo; Olivero de Briceno, Rosa; Mendes, Rinaldo Poncio

2005-01-01

11

Influence of N-Glycosylation on the Morphogenesis and Growth of Paracoccidioides brasiliensis and on the Biological Activities of Yeast Proteins  

Microsoft Academic Search

The fungus Paracoccidioides brasiliensis is a human pathogen that causes paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America. The cell wall of P. brasiliensis is a network of glycoproteins and polysaccharides, such as chitin, that perform several functions. N-linked glycans are involved in glycoprotein folding, intracellular transport, secretion, and protection from proteolytic degradation. Here, we report the effects of

Fausto Bruno Dos Reis Almeida; Fernanda Caroline Carvalho; Vânia Sammartino Mariano; Ana Claudia Paiva Alegre; Roberto do Nascimento Silva; Ebert Seixas Hanna; Maria Cristina Roque-Barreira

2011-01-01

12

Paracoccidioides brasiliensis pancreatic destruction in Calomys callosus experimentally infected  

PubMed Central

Background The wild rodent Calomys callosus is notably resistant to Trypanosoma cruzi infection. In order to better characterize this animal model for experimental infections, we inoculated C. callosus intraperitoneally with Paracoccidioides brasiliensis, a thermally dimorphic fungus that causes a chronic disease with severe granuloma formation in the mouse and humans. The dissemination of P. brasiliensis cells through the lungs, liver, pancreas, and spleen was assessed by histological analysis. Results The animals were susceptible to infection and showed a granulomatous reaction. C. callosus presented peritonitis characterized by the presence of exudates containing a large number of yeast cells. Extensive accumulation of yeast cells with intense destruction of the parenchyma was observed in the pancreas, which reduced the glucose levels of infected animals. These lesions were regressive in the liver, spleen, and lungs until complete recovery. The role of estrogen during C. callosus infection with P. brasiliensis was addressed by infecting ovariectomized animals. It was observed a reduced inflammatory response as well as reduced extension of tissue damage. Removal of ovaries reestablished the normal glucose levels during infection. Conclusion Taken together, the results presented here reveal the pancreas as being an important organ for the persistence of P. brasiliensis during infection of C. callosus and that estrogen plays an important role in the susceptibility of the animals to this pathogen.

2009-01-01

13

5-Lipoxygenase Activity Increases Susceptibility to Experimental Paracoccidioides brasiliensis Infection  

PubMed Central

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the thermodimorphic fungus Paracoccidioides brasiliensis. Leukotrienes and lipoxins are lipid mediators produced after 5-lipoxygenase (5-LO) activation that exhibit pro- and anti-inflammatory roles, respectively. Here, we have investigated the contribution of 5-LO enzymatic activity in PCM using an experimental model of P. brasiliensis infection. B6.129 wild-type (B6.129) and 5-LO-deficient (5-LO?/?) mice were intravenously inoculated with a virulent strain of P. brasiliensis (Pb18), and the survival rate of the infected mice was investigated on different days after yeast infection. 5-LO?/? mice exhibited an increased survival rate associated with a decreased number of CFU. The resistance of 5-LO?/? during PCM was associated with augmented nitric oxide (NO) production and the formation of compact granulomas. In addition, the absence of 5-LO was associated with a diminished number of CD4+ CD25+ regulatory T cells, higher levels of gamma interferon and interleukin-12, and increased T-bet (a T-box transcription factor that directs Th1 lineage commitment) mRNA levels in the lungs. Taken together, our results show for the first time that 5-LO enzymatic activity increases susceptibility to P. brasiliensis, suggesting that this pathway may be a potential target for therapeutic intervention during PCM.

Tristao, Fabrine Sales Massafera; Rocha, Fernanda Agostini; Moreira, Ana Paula; Cunha, Fernando Queiroz; Rossi, Marcos Antonio

2013-01-01

14

Pulmonary immune responses induced in BALB\\/c mice by Paracoccidioides brasiliensis conidia  

Microsoft Academic Search

Knowledge concerning the host–Paracoccidioides brasiliensis interactions is abundant. Yet, most of the experimental studies have used yeast cells to prepare the corresponding inoculum.\\u000a As these cells do not represent the naturally infecting propagules, the corresponding experiments by-pass the earlier stages\\u000a of such interactions. Studies done in patients, who also harbour yeast cells, suffer from the same bias. The review presented

Angel González; Angela Restrepo; Luz Elena Cano

2008-01-01

15

Paracoccidioides brasiliensis in a brain abscess: First French case  

Microsoft Academic Search

Paracoccidioides brasiliensis is a fungus geographically restricted to South America. Because of the long lasting evolution, imported cases of the disease could be diagnosed anywhere in immigrants. Cases remain actually rare in Europe: we report here the first case notified to the French National Reference Center for Mycoses.

D. M. Poisson; A. Heitzmann; C. Mille; B. Muckensturm; F. Dromer; B. Dupont; L. Hocqueloux

2007-01-01

16

A secreted serine protease of Paracoccidioides brasiliensis and its interactions with fungal proteins  

Microsoft Academic Search

BACKGROUND: Paracoccidioides brasiliensis is a thermodimorphic fungus, the causative agent of paracoccidioidomycosis (PCM). Serine proteases are widely distributed and this class of peptidase has been related to pathogenesis and nitrogen starvation in pathogenic fungi. RESULTS: A cDNA (Pbsp) encoding a secreted serine protease (PbSP), was isolated from a cDNA library constructed with RNAs of fungal yeast cells recovered from liver

Juliana A Parente; Sílvia M Salem-Izacc; Jaime M Santana; Maristela Pereira; Clayton L Borges; Alexandre M Bailão; Célia MA Soares

2010-01-01

17

Modulation of the exocellular serine-thiol proteinase activity of Paracoccidioides brasiliensis by neutral polysaccharides  

Microsoft Academic Search

Our group characterized an exocellular serine-thiol proteinase activity in the yeast phase of Paracoccidioides brasiliensis (PbST), a dimorphic human pathogen. The fungal proteinase is able to cleave in vitro, at pH 7.4, proteins associated with the basal membrane, such as human laminin and fibronectin, type IV collagen and proteoglycans. In the present study, we investigated the influence of glycosaminoglycans (GAGs)

Alisson L. Matsuo; Ivarne I. L. Tersariol; Silvia I. Kobata; Luiz R. Travassos; Adriana K. Carmona; Rosana Puccia

2006-01-01

18

The stress responsive and morphologically regulated hsp90 gene from Paracoccidioides brasiliensis is essential to cell viability  

Microsoft Academic Search

BACKGROUND: Paracoccidioides brasiliensis is a dimorphic fungus that causes the most prevalent systemic mycosis in Latin America. The response to heat shock is involved in pathogenesis, as this pathogen switches from mycelium to yeast forms in a temperature dependent fashion that is essential to establish infection. HSP90 is a molecular chaperone that helps in the folding and stabilization of selected

André M Nicola; Rosângela V Andrade; Alessandra S Dantas; Patrícia A Andrade; Fabrício BM Arraes; Larissa Fernandes; Ildinete Silva-Pereira; Maria Felipe

2008-01-01

19

Interactions of Paracoccidioides brasiliensis with host cells: recent advances  

Microsoft Academic Search

Host-fungal interactions are inherently complex and dynamic. In order to identify new microbial targets and develop more effective\\u000a anti-fungal therapies, it is important to understand the cellular and molecular mechanisms of disease. Paracoccidioidomycosis\\u000a provokes a variety of clinical symptoms, and Paracoccidioides brasiliensis can reach many tissues, but primarily attacks the lungs. The ability of the pathogen to interact with the

Maria José Soares Mendes-Giannini; Juliana Leal Monteiro da Silva; Julhiany de Fátima da Silva; Fabiana Cristina Donofrio; Elaine Toscano Miranda; Patrícia Ferrari Andreotti; Christiane Pienna Soares

2008-01-01

20

Oxidative stress response in Paracoccidioides brasiliensis  

Microsoft Academic Search

Survival of pathogenic fungi inside human hosts depends on evasion from the host immune system and adaptation to the host environment. Among different insults that Paracoccidioides brasilien- sis has to handle are reactive oxygen and nitrogen species produced by the human host cells, and by its own metabolism. Knowing how the parasite deals with reactive species is important to understand

Élida G. Campos; Rosália Santos; Amorim Jesuino; Alessandra da Silva Dantas; Marcelo de Macedo Brígido; Maria Sueli; S. Felipe

2005-01-01

21

Antimicrobial effect of farnesol, a Candida albicans quorum sensing molecule, on Paracoccidioides brasiliensis growth and morphogenesis  

PubMed Central

Background Farnesol is a sesquiterpene alcohol produced by many organisms, and also found in several essential oils. Its role as a quorum sensing molecule and as a virulence factor of Candida albicans has been well described. Studies revealed that farnesol affect the growth of a number of bacteria and fungi, pointing to a potential role as an antimicrobial agent. Methods Growth assays of Paracoccidioides brasiliensis cells incubated in the presence of different concentrations of farnesol were performed by measuring the optical density of the cultures. The viability of fungal cells was determined by MTT assay and by counting the colony forming units, after each farnesol treatment. The effects of farnesol on P. brasiliensis dimorphism were also evaluated by optical microscopy. The ultrastructural morphology of farnesol-treated P. brasiliensis yeast cells was evaluated by transmission and scanning electron microscopy. Results In this study, the effects of farnesol on Paracoccidioides brasiliensis growth and dimorphism were described. Concentrations of this isoprenoid ranging from 25 to 300 ?M strongly inhibited P. brasiliensis growth. We have estimated that the MIC of farnesol for P. brasiliensis is 25 ?M, while the MLC is around 30 ?M. When employing levels which don't compromise cell viability (5 to 15 ?M), it was shown that farnesol also affected the morphogenesis of this fungus. We observed about 60% of inhibition in hyphal development following P. brasiliensis yeast cells treatment with 15 ?M of farnesol for 48 h. At these farnesol concentrations we also observed a significant hyphal shortening. Electron microscopy experiments showed that, despite of a remaining intact cell wall, P. brasiliensis cells treated with farnesol concentrations above 25 ?M exhibited a fully cytoplasmic degeneration. Conclusion Our data indicate that farnesol acts as a potent antimicrobial agent against P. brasiliensis. The fungicide activity of farnesol against this pathogen is probably associated to cytoplasmic degeneration. In concentrations that do not affect fungal viability, farnesol retards the germ-tube formation of P. brasiliensis, suggesting that the morphogenesis of this fungal is controlled by environmental conditions.

Derengowski, Lorena S; De-Souza-Silva, Calliandra; Braz, Shelida V; Mello-De-Sousa, Thiago M; Bao, Sonia N; Kyaw, Cynthia M; Silva-Pereira, Ildinete

2009-01-01

22

Phospholipase gene expression during Paracoccidioides brasiliensis morphological transition and infection.  

PubMed

Phospholipase is an important virulence factor for pathogenic fungi. In this study, we demonstrate the following: (i) the Paracoccidioides brasiliensis pld gene is preferentially expressed in mycelium cells, (ii) the plb1 gene is mostly up-regulated by infection after 6 h of co-infection of MH-S cells or during BALB/c mice lung infection, (iii) during lung infection, plb1, plc and pld gene expression are significantly increased 6-48 h post-infection compared to 56 days after infection, strongly suggesting that phospholipases play a role in the early events of infection, but not during the chronic stages of pulmonary infection by P. brasiliensis. PMID:24037207

Soares, Deyze Alencar; Oliveira, Marilia Barros; Evangelista, Adriane Feijó; Venancio, Emerson José; Andrade, Rosângela Vieira; Felipe, Maria Sueli Soares; Petrofeza, Silvana

2013-09-01

23

Proteomic Analysis Reveals That Iron Availability Alters the Metabolic Status of the Pathogenic Fungus Paracoccidioides brasiliensis  

Microsoft Academic Search

Paracoccidioides brasiliensis is a thermodimorphic fungus and the causative agent of paracoccidioidomycosis (PCM). The ability of P. brasiliensis to uptake nutrients is fundamental for growth, but a reduction in the availability of iron and other nutrients is a host defense mechanism many pathogenic fungi must overcome. Thus, fungal mechanisms that scavenge iron from host may contribute to P. brasiliensis virulence.

Ana F. A. Parente; Alexandre M. Bailão; Clayton L. Borges; Juliana A. Parente; Adriana D. Magalhães; Carlos A. O. Ricart; Célia M. A. Soares

2011-01-01

24

Cell wall glucan synthases and GTPases in Paracoccidioides brasiliensis.  

PubMed

In this report we identified orthologues of fungal AGS1, RHO1, RHO2, RAC1 and CDC42 genes in the dimorphic fungus Paracoccidioides brasiliensis. Based on its homology to known fungal sequences, P. brasiliensis Ags1 was identified as an alpha-1,3-glucan synthase, while Rho1, Rho2, Rac1 and Cdc42 proteins were classified into the Rho1, Rho2, Rac1 and Cdc42 subgroups of fungal Rho GTPases, respectively. Of them, Rho1 is one of two subunits of a putative beta-1,3-glucan synthase complex, the other being the synthase itself (Fks1), while Rho2 has been associated to the alpha-1,3-glucan synthase (Ags1). Expression studies showed that mRNAs levels of RHO2 and AGS1 kept a direct relationship but the levels of RHO1 and FKS1 did not. P. brasiliensis RHO1 successfully restored growth of Saccharomyces cerevisiae rho1 mutant under restrictive temperature conditions. Chemical analyses of P. brasiliensis alpha-1,3-glucan, synthesized by Ags1p, indicated that it is essentially a linear polysaccharide, with <3% of alpha-1,4-linked glucose branches, occasionally attached as single units to the alpha-1,3-backbone. PMID:19225978

Sorais, Françoise; Barreto, Laura; Leal, Juan Antonio; Bernabé, Manuel; San-Blas, Gioconda; Niño-Vega, Gustavo A

2010-02-01

25

TLR9 Activation Dampens the Early Inflammatory Response to Paracoccidioides brasiliensis, Impacting Host Survival  

PubMed Central

Background Paracoccidioides brasiliensis causes paracoccidioidomycosis, one of the most prevalent systemic mycosis in Latin America. Thus, understanding the characteristics of the protective immune response to P. brasiliensis is of interest, as it may reveal targets for disease control. The initiation of the immune response relies on the activation of pattern recognition receptors, among which are TLRs. Both TLR2 and TLR4 have been implicated in the recognition of P. brasiliensis and regulation of the immune response. However, the role of TLR9 during the infection by this fungus remains unclear. Methodology/Principal findings We used in vitro and in vivo models of infection by P. brasiliensis, comparing wild type and TLR9 deficient (?/?) mice, to assess the contribution of TLR9 on cytokine induction, phagocytosis and outcome of infection. We show that TLR9 recognizes either the yeast form or DNA from P. brasiliensis by stimulating the expression/production of pro-inflammatory cytokines by bone marrow derived macrophages, also increasing their phagocytic ability. We further show that TLR9 plays a protective role early after intravenous infection with P. brasiliensis, as infected TLR9?/? mice died at higher rate during the first 48 hours post infection than wild type mice. Moreover, TLR9?/? mice presented tissue damage and increased expression of several cytokines, such as TNF-? and IL-6. The increased pattern of cytokine expression was also observed during intraperitoneal infection of TLR9?/? mice, with enhanced recruitment of neutrophils. The phenotype of TLR9?/? hosts observed during the early stages of P. brasiliensis infection was reverted upon a transient, 48 hours post-infection, neutrophil depletion. Conclusions/Significance Our results suggest that TLR9 activation plays an early protective role against P. brasiliensis, by avoiding a deregulated type of inflammatory response associated to neutrophils that may lead to tissue damage. Thus modulation of TLR9 may be of interest to potentiate the host response against this pathogen.

Menino, Joao Filipe; Saraiva, Margarida; Gomes-Alves, Ana G.; Lobo-Silva, Diogo; Sturme, Mark; Gomes-Rezende, Jessica; Saraiva, Ana Laura; Goldman, Gustavo H.; Cunha, Cristina; Carvalho, Agostinho; Romani, Luigina; Pedrosa, Jorge; Castro, Antonio Gil; Rodrigues, Fernando

2013-01-01

26

Detection of Antibodies against Paracoccidioides brasiliensis Melanin in In Vitro and In Vivo Studies during Infection ?  

PubMed Central

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) ?-chain and four IgM melanin-binding MAbs. The five IgG1 ?-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice.

Uran, Martha E.; Nosanchuk, Joshua D.; Restrepo, Angela; Hamilton, Andrew J.; Gomez, Beatriz L.; Cano, Luz E.

2011-01-01

27

Production of leukotriene B4 by Paracoccidioides brasiliensis.  

PubMed

Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, the most prevalent deep mycosis in Latin America. The production of eicosanoids during fungal infection has been associated with the biology of these microorganisms and modulation of host immune response. The aim of our study was to evaluate whether P. brasiliensis strains with high or low virulence produce leukotriene B4 (LTB4), using endogenous and/or exogenous sources of arachidonic acid (AA). Moreover, we assessed whether this fungus might use the same metabolic pathway, described for mammalian cells, that involves the lipoxygenase (LOX) enzyme. The association between the production of this eicosanoid and fungus survival and growth was also evaluated. Our results showed that P. brasiliensis, irrespective of its virulence, produces high levels of LTB4 using endogenous AA. In addition, in cultures treated with exogenous AA, LTB4 levels were significantly higher, showing that this fungus also uses exogenous sources of fatty acids. Treatment with MK886, which blocks the activity of lipoxygenase, by inhibiting five-lipoxygenase-activating protein (FLAP) or with nordihydroguaiaretic acid (NDGA), a non-selective lipoxygenase inhibitor, resulted in a significant reduction in LTB4 levels, indicating that the fungus produces this eicosanoid by using the LOX pathway or an enzyme with biochemically similar function. The significant reduction in viability detected in cultures treated with these inhibitors was, however, restored by adding exogenous LTB4 , confirming the role of this eicosanoid in fungus survival. Moreover, the addition of LTB4 to cultures capable of producing LTs induces fungal growth. These results provide a foundation for additional studies on the contributions of LTB4 in P. brasiliensis virulence. PMID:22628121

Biondo, Guilherme Augusto; Dias-Melicio, Luciane Alarcão; Bordon-Graciani, Ana Paula; Kurokawa, Cilmery Suemi; de Campos Soares, Angela Maria Victoriano

2012-05-24

28

Detection of Melanin-Like Pigments in the Dimorphic Fungal Pathogen Paracoccidioides brasiliensis In Vitro and during Infection  

PubMed Central

Melanins are implicated in the pathogenesis of several human diseases, including some microbial infections. In this study, we analyzed whether the conidia and the yeasts of the thermally dimorphic fungal pathogen Paracoccidioides brasiliensis produce melanin or melanin-like compounds in vitro and during infection. Growth of P. brasiliensis mycelia on water agar alone produced pigmented conidia, and growth of yeasts in minimal medium with l-3,4-dihydroxyphenylalanine (l-DOPA) produced pigmented cells. Digestion of the pigmented conidia and yeasts with proteolytic enzymes, denaturant, and hot concentrated acid yielded dark particles that were the same size and shape as their propagules. Immunofluorescence analysis demonstrated reactivity of a melanin-binding monoclonal antibody (MAb) with the pigmented conidia, yeasts, and particles. Electron spin resonance spectroscopy identified the yeast-derived particles produced in vitro when P. brasiliensis was grown in l-DOPA medium as a melanin-like compound. Nonreducing polyacrylamide gel electrophoresis of cytoplasmic yeast extract revealed a protein that catalyzed melanin synthesis from l-DOPA. The melanin binding MAb reacted with yeast cells in tissue from mice infected with P. brasiliensis. Finally digestion of infected tissue liberated particles reactive to the melanin binding MAb that had the typical morphology of P. brasiliensis yeasts. These data strongly suggest that P. brasiliensis propagules, both conidia and yeast cells, can produce melanin or melanin-like compounds in vitro and in vivo. Based on what is known about the function of melanin in the virulence of other fungi, this pigment may play a role in the pathogenesis of paracoccidioidomycosis.

Gomez, Beatriz L.; Nosanchuk, Joshua D.; Diez, Soraya; Youngchim, Sirida; Aisen, Philip; Cano, Luz E.; Restrepo, Angela; Casadevall, Arturo; Hamilton, Andrew J.

2001-01-01

29

Expression of a kexin-like gene from the human pathogenic fungus Paracoccidioides brasiliensis in Saccharomyces cerevisiae.  

PubMed

Kexin-like proteins are proteinases belonging to the subtilase family which are involved in the processing of pro-proteins to their active forms. In fungi, kexin-like proteins are involved in several important cellular processes, including mating and dimorphism. Paracoccidioides brasiliensis, the causative agent of paracoccidioidomycosis undergoes a thermo-regulated dimorphic transition which is essential for the establishment of the infection. Although the molecular mechanisms which rule this process are still unknown, several genes identified in P. brasiliensis have been implicated in dimorphism, including kex2, a kexin-like protein. In this work we have used the baker's yeast Saccharomyces cerevisiae as a host to perform heterologous expression analysis of the P. brasiliensis kex2 gene. Our data shows that kex2 can complement the functions of a S. cerevisiae kex2 mutant strain and could therefore be considered its functional homologue. PMID:18415848

Torres, Fernando Araripe Gonçalves; Vilaça, Rosemary; Pepe De Moraes, Lidia Maria; Reis, Viviane Castelo Branco; Felipe, Maria Sueli Soares

2008-06-01

30

Oenothein B inhibits the expression of PbFKS1 transcript and induces morphological changes in Paracoccidioides brasiliensis.  

PubMed

The fungus Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis (PCM), the most prevalent human systemic mycosis in Latin America. Drug toxicity and the appearance of resistant strains have created the need to search for new therapeutic approaches. Plants with reputed antimicrobial properties represent a rich screening source of potential antifungal compounds. In this work, the growth of P. brasiliensis yeast cells was evaluated in the presence of oenothein B extracted from Eugenia uniflora. The oenothein B dosage that most effectively inhibited the development (74%) of P. brasiliensis yeast cells in vitro was 500 microg/ml. To verify if oenothein B interferes with cell morphology, we observed oenothein B-treated yeast cells by electron microscopy. The micrographs showed characteristic cell changes noted with glucan synthesis inhibition, including squashing, rough surface, cell wall rupture and cell membrane recess. The expression of P. brasiliensis genes was evaluated in order to investigate the action of oenothein B. Here we report that oenothein B inhibits 1,3-beta-glucan synthase (PbFKS1) transcript accumulation. The results indicate that oenothein B interferes with the cell morphology of P. brasiliensis, probably by inhibiting the transcription of 1,3-beta-glucan synthase gene, which is involved in the cell wall synthesis. PMID:18033615

Santos, Glaciane D; Ferri, Pedro H; Santos, Suzana C; Bao, Sônia N; Soares, Célia M A; Pereira, Maristela

2007-11-01

31

The Pathogenic Fungus Paracoccidioides brasiliensis Exports Extracellular Vesicles Containing Highly Immunogenic ?-Galactosyl Epitopes?  

PubMed Central

Exosome-like vesicles containing virulence factors, enzymes, and antigens have recently been characterized in fungal pathogens, such as Cryptococcus neoformans and Histoplasma capsulatum. Here, we describe extracellular vesicles carrying highly immunogenic ?-linked galactopyranosyl (?-Gal) epitopes in Paracoccidioides brasiliensis. P. brasiliensis is a dimorphic fungus that causes human paracoccidioidomycosis (PCM). For vesicle preparations, cell-free supernatant fluids from yeast cells cultivated in Ham's defined medium-glucose were concentrated in an Amicon ultrafiltration system and ultracentrifuged at 100,000 × g. P. brasiliensis antigens were present in preparations from phylogenetically distinct isolates Pb18 and Pb3, as observed in immunoblots revealed with sera from PCM patients. In an enzyme-linked immunosorbent assay (ELISA), vesicle components containing ?-Gal epitopes reacted strongly with anti-?-Gal antibodies isolated from both Chagas' disease and PCM patients, with Marasmius oreades agglutinin (MOA) (a lectin that recognizes terminal ?-Gal), but only faintly with natural anti-?-Gal. Reactivity was inhibited after treatment with ?-galactosidase. Vesicle preparations analyzed by electron microscopy showed vesicular structures of 20 to 200 nm that were labeled both on the surface and in the lumen with MOA. In P. brasiliensis cells, components carrying ?-Gal epitopes were found distributed on the cell wall, following a punctuated confocal pattern, and inside large intracellular vacuoles. Lipid-free vesicle fractions reacted with anti-?-Gal in ELISA only when not digested with ?-galactosidase, while reactivity with glycoproteins was reduced after ?-elimination, which is indicative of partial O-linked chain localization. Our findings open new areas to explore in terms of host-parasite relationships in PCM and the role played in vivo by vesicle components and ?-galactosyl epitopes.

Vallejo, Milene C.; Matsuo, Alisson L.; Ganiko, Luciane; Medeiros, Lia C. Soares; Miranda, Kildare; Silva, Luiz S.; Freymuller-Haapalainen, Edna; Sinigaglia-Coimbra, Rita; Almeida, Igor C.; Puccia, Rosana

2011-01-01

32

The pathogenic fungus Paracoccidioides brasiliensis exports extracellular vesicles containing highly immunogenic ?-Galactosyl epitopes.  

PubMed

Exosome-like vesicles containing virulence factors, enzymes, and antigens have recently been characterized in fungal pathogens, such as Cryptococcus neoformans and Histoplasma capsulatum. Here, we describe extracellular vesicles carrying highly immunogenic ?-linked galactopyranosyl (?-Gal) epitopes in Paracoccidioides brasiliensis. P. brasiliensis is a dimorphic fungus that causes human paracoccidioidomycosis (PCM). For vesicle preparations, cell-free supernatant fluids from yeast cells cultivated in Ham's defined medium-glucose were concentrated in an Amicon ultrafiltration system and ultracentrifuged at 100,000 × g. P. brasiliensis antigens were present in preparations from phylogenetically distinct isolates Pb18 and Pb3, as observed in immunoblots revealed with sera from PCM patients. In an enzyme-linked immunosorbent assay (ELISA), vesicle components containing ?-Gal epitopes reacted strongly with anti-?-Gal antibodies isolated from both Chagas' disease and PCM patients, with Marasmius oreades agglutinin (MOA) (a lectin that recognizes terminal ?-Gal), but only faintly with natural anti-?-Gal. Reactivity was inhibited after treatment with ?-galactosidase. Vesicle preparations analyzed by electron microscopy showed vesicular structures of 20 to 200 nm that were labeled both on the surface and in the lumen with MOA. In P. brasiliensis cells, components carrying ?-Gal epitopes were found distributed on the cell wall, following a punctuated confocal pattern, and inside large intracellular vacuoles. Lipid-free vesicle fractions reacted with anti-?-Gal in ELISA only when not digested with ?-galactosidase, while reactivity with glycoproteins was reduced after ?-elimination, which is indicative of partial O-linked chain localization. Our findings open new areas to explore in terms of host-parasite relationships in PCM and the role played in vivo by vesicle components and ?-galactosyl epitopes. PMID:21216942

Vallejo, Milene C; Matsuo, Alisson L; Ganiko, Luciane; Medeiros, Lia C Soares; Miranda, Kildare; Silva, Luiz S; Freymüller-Haapalainen, Edna; Sinigaglia-Coimbra, Rita; Almeida, Igor C; Puccia, Rosana

2011-01-07

33

Modulation of the exocellular serine-thiol proteinase activity of Paracoccidioides brasiliensis by neutral polysaccharides.  

PubMed

Our group characterized an exocellular serine-thiol proteinase activity in the yeast phase of Paracoccidioides brasiliensis (PbST), a dimorphic human pathogen. The fungal proteinase is able to cleave in vitro, at pH 7.4, proteins associated with the basal membrane, such as human laminin and fibronectin, type IV collagen and proteoglycans. In the present study, we investigated the influence of glycosaminoglycans (GAGs) and neutral polysaccharides upon the serine-thiol proteinase activity by means of kinetic analysis monitored with fluorescence resonance energy transfer (FRET) peptides using the substrate Abz-MKALTLQ-EDDnp (Abz=ortho-aminobenzoic acid; EDDnp=ethylenediaminedinitrophenyl). Only neutral polysaccharides exhibited patterns of interaction with the proteinase, while sulfated GAGs had no effect. Incubation with neutral polysaccharides resulted in a powerful modulation of the enzyme activity, intensely changing the enzyme kinetic parameters of catalysis and affinity for the substrate. Commercial dextran at the highest concentration of 20 microM increased 6.8-fold the enzyme affinity for the substrate. In the presence of 8 microM of purified baker's yeast mannan, the apparent KM of the enzyme increased about 5.5-fold, reflecting a significant inhibition in binding to the peptide substrate. When an exocellular galactomannan (GalMan) complex isolated from P. brasiliensis was added to the reaction mixture at 400 nM, the apparent KM and VMAX decreased about threefold. Moreover, GalMan was able to protect the enzymatic activity at high temperatures, but it caused no effect on the optimum cleavage pH. Our results show a novel modulation mechanism in P. brasiliensis, where a fungal polysaccharide-rich component can stabilize a serine-thiol proteolytic activity, which is possibly involved in fungal dissemination. PMID:16153872

Matsuo, Alisson L; Tersariol, Ivarne I L; Kobata, Silvia I; Travassos, Luiz R; Carmona, Adriana K; Puccia, Rosana

2005-08-08

34

Lipidomic Analysis of Extracellular Vesicles from the Pathogenic Phase of Paracoccidioides brasiliensis  

PubMed Central

Background Fungal extracellular vesicles are able to cross the cell wall and transport molecules that help in nutrient acquisition, cell defense, and modulation of the host defense machinery. Methodology/Principal Findings Here we present a detailed lipidomic analysis of extracellular vesicles released by Paracoccidioides brasiliensis at the yeast pathogenic phase. We compared data of two representative isolates, Pb3 and Pb18, which have distinct virulence profiles and phylogenetic background. Vesicle lipids were fractionated into different classes and analyzed by either electrospray ionization- or gas chromatography-mass spectrometry. We found two species of monohexosylceramide and 33 phospholipid species, including phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol. Among the phospholipid-bound fatty acids in extracellular vesicles, C181 predominated in Pb3, whereas C18:2 prevailed in Pb18. The prevalent sterol in Pb3 and Pb18 vesicles was brassicasterol, followed by ergosterol and lanosterol. Inter-isolate differences in sterol composition were observed, and also between extracellular vesicles and whole cells. Conclusions/Significance The extensive lipidomic analysis of extracellular vesicles from two P. brasiliensis isolates will help to understand the composition of these fungal components/organelles and will hopefully be useful to study their biogenesis and role in host-pathogen interactions.

Longo, Larissa V. G.; Ganiko, Luciane; Lopes, Felipe G.; Matsuo, Alisson L.; Almeida, Igor C.; Puccia, Rosana

2012-01-01

35

Cell survival and altered gene expression following photodynamic inactivation of Paracoccidioides brasiliensis.  

PubMed

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides brasiliensis. Currently, the treatment approach involves the use of antifungal drugs and requires years of medical therapy, which can induce nephrotoxicity and lead to resistance in yeast strains. Photodynamic inactivation (PDI) is a new therapy capable of killing microorganisms via the combination of a nontoxic dye with visible light to generate toxic reactive oxygen species (ROS). We investigated the phototoxic effect of 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP), a cationic porphyrin, on the survival of P. brasiliensis following exposure to light. Phototoxicity was found to depend on both the fluence and concentration of the photosensitizer (PS). Although the biological effects of PDI are known, the molecular mechanisms underlying the resultant damage to cells are poorly defined. Therefore, we evaluated the molecular response to PDI-induced oxidative stress by gene transcription analysis. We selected genes associated with the high-osmolarity glycerol (HOG)-mitogen-activated protein kinase (MAPK) pathway and antioxidant enzymes. The genes analyzed were all overexpressed after PDI treatment, suggesting that the oxidative stress generated in our experimental conditions induces antioxidant activity. In addition to PDI-induced gene expression, there was high cell mortality, suggesting that the antioxidant response was not sufficient to avoid fungal mortality. PMID:22332981

Almeida, Luciane M; Zanoelo, Fabiana F; Castro, Kelly P; Borissevitch, Iouri E; Soares, Célia M A; Gonçalves, Pablo J

2012-03-08

36

Cryptic Speciation and Recombination in the Fungus Paracoccidioides brasiliensis as Revealed by Gene Genealogies  

Microsoft Academic Search

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis, a disease confined to Latin America and of marked importance in the endemic areas due to its frequency and severity. This species is considered to be clonal according to mycological criteria and has been shown to vary in virulence. To characterize natural genetic variation and reproductive mode in this fungus, we analyzed

Daniel R. Matute; Juan G. McEwen; Rosana Puccia; Beatriz A. Montes; Gioconda San-Blas; Eduardo Bagagli; Jason T. Rauscher; Angela Restrepo; Favia Morais; Gustavo Nino-Vega; John W. Taylor

2005-01-01

37

Biosynthesis of chondroitinase and hyaluronidase by different strains of Paracoccidioides brasiliensis.  

PubMed

The biosynthesis of chondroitinase and hyaluronidase by different isolates of Paracoccidioides brasiliensis was investigated in 20 strains isolated from patients (17 strains), a penguin (Pygocelis adeliae, one strain), an armadillo (Dasypus novemcinctus, one strain) and the environment (dog food, one strain). All the P. brasiliensis isolates studied had the ability to produce chondroitinase and hyaluronidase, although differences in colony morphology and enzyme production were detected among them. These results suggest that further investigations should be carried out in the clinical field in order to clarify the potential role of P. brasiliensis enzyme production in the pathogenesis of paracoccidioidomycosis. PMID:12748266

de Assis, C M; Gandra, R F; Gambale, W; Shimizu, M T; Paula, C R

2003-06-01

38

Analysis of the Secretomes of Paracoccidioides Mycelia and Yeast Cells  

PubMed Central

Paracoccidioides, a complex of several phylogenetic species, is the causative agent of paracoccidioidomycosis. The ability of pathogenic fungi to develop a multifaceted response to the wide variety of stressors found in the host environment is important for virulence and pathogenesis. Extracellular proteins represent key mediators of the host-parasite interaction. To analyze the expression profile of the proteins secreted by Paracoccidioides, Pb01 mycelia and yeast cells, we used a proteomics approach combining two-dimensional electrophoresis with matrix-assisted laser desorption ionization quadrupole time-of-flight mass spectrometry (MALDI-Q-TOF MS/MS). From three biological replicates, 356 and 388 spots were detected, in mycelium and yeast cell secretomes, respectively. In this study, 160 non-redundant proteins/isoforms were indentified, including 30 and 24 proteins preferentially secreted in mycelia and yeast cells, respectively. In silico analyses revealed that 65% of the identified proteins/isoforms were secreted primarily via non-conventional pathways. We also investigated the influence of protein export inhibition in the phagocytosis of Paracoccidioides by macrophages. The addition of Brefeldin A to the culture medium significantly decreased the production of secreted proteins by both Paracoccidioides and internalized yeast cells by macrophages. In contrast, the addition of concentrated culture supernatant to the co-cultivation significantly increased the number of internalized yeast cells by macrophages. Importantly, the proteins detected in the fungal secretome were also identified within macrophages. These results indicate that Paracoccidioides extracellular proteins are important for the fungal interaction with the host.

Weber, Simone Schneider; Parente, Ana Flavia Alves; Borges, Clayton Luiz; Parente, Juliana Alves; Bailao, Alexandre Melo; de Almeida Soares, Celia Maria

2012-01-01

39

Expression of Paracoccidioides brasiliensis AMY1 in a Histoplasma capsulatum amy1 Mutant, Relates an ?-(1,4)-Amylase to Cell Wall ?-(1,3)-Glucan Synthesis  

PubMed Central

In the cell walls of the pathogenic yeast phases of Paracoccidioides brasiliensis, Blastomyces dermatitidis and Histoplasma capsulatum, the outer ?-(1,3)-glucan layer behaves as a virulence factor. In H. capsulatum, an ?-(1,4)-amylase gene (AMY1) is essential for the synthesis of this polysaccharide, hence related to virulence. An orthologous gene to H. capsulatum AMY1 was identified in P. brasiliensis and also labeled AMY1. P. brasiliensis AMY1 transcriptional levels were increased during the yeast phase, which correlates with the presence of ?-(1,3)-glucan as the major yeast cell wall polysaccharide. Complementation of a H. capsulatum amy1 mutant strain with P. brasiliensis AMY1, suggests that P. brasiliensis Amy1p may play a role in the synthesis of cell wall ?-(1,3)-glucan. To study some biochemical properties of P. brasiliensis Amy1p, the enzyme was overexpressed, purified and studied its activity profile with starch and amylopeptin. It showed a relatively higher hydrolyzing activity on amylopeptin than starch, producing oligosaccharides from 4 to 5 glucose residues. Our findings show that P. brasiliensis Amy1p produces maltooligosaccharides which may act as a primer molecule for the fungal cell wall ?-(1,3)-glucan biosynthesis by Ags1p.

Camacho, Emma; Sepulveda, Victoria E.; Goldman, William E.; San-Blas, Gioconda; Nino-Vega, Gustavo A.

2012-01-01

40

Low Concentrations of Hydrogen Peroxide or Nitrite Induced of Paracoccidioides brasiliensis Cell Proliferation in a Ras-Dependent Manner  

PubMed Central

Paracoccidioides brasiliensis, a causative agent of paracoccidioidomycosis (PCM), should be able to adapt to dramatic environmental changes inside the infected host after inhalation of air-borne conidia and transition to pathogenic yeasts. Proteins with antioxidant functions may protect fungal cells against reactive oxygen (ROS) and nitrogen (RNS) species generated by phagocytic cells, thus acting as potential virulence factors. Ras GTPases are involved in stress responses, cell morphology, and differentiation in a range of organisms. Ras, in its activated form, interacts with effector proteins and can initiate a kinase cascade. In lower eukaryotes, Byr2 kinase represents a Ras target. The present study investigated the role of Ras in P. brasiliensis after in vitro stimulus with ROS or RNS. We have demonstrated that low concentrations of H2O2 (0.1 mM) or NO2 (0.1–0.25 µM) stimulated P. brasiliensis yeast cell proliferation and that was not observed when yeast cells were pre-incubated with farnesyltransferase inhibitor. We constructed an expression plasmid containing the Byr2 Ras-binding domain (RBD) fused with GST (RBD-Byr2-GST) to detect the Ras active form. After stimulation with low concentrations of H2O2 or NO2, the Ras active form was observed in fungal extracts. Besides, NO2 induced a rapid increase in S-nitrosylated Ras levels. This alternative posttranslational modification of Ras, probably in residue Cys123, would lead to an exchange of GDP for GTP and consequent GTPase activation in P. brasiliensis. In conclusion, low concentrations of H2O2 or NO2 stimulated P. brasiliensis proliferation through Ras activation.

Haniu, Ana Eliza Coronel Janu; Maricato, Juliana Terzi; Mathias, Pedro Paulo Moraes; Castilho, Daniele Goncalves; Miguel, Rodrigo Bernardi; Monteiro, Hugo Pequeno; Puccia, Rosana; Batista, Wagner Luiz

2013-01-01

41

Glyceraldehyde-3-Phosphate Dehydrogenase of Paracoccidioides brasiliensis Is a Cell Surface Protein Involved in Fungal Adhesion to Extracellular Matrix Proteins and Interaction with Cells  

PubMed Central

The pathogenic fungus Paracoccidioides brasiliensis causes paracoccidioidomycosis, a pulmonary mycosis acquired by inhalation of fungal airborne propagules, which may disseminate to several organs and tissues, leading to a severe form of the disease. Adhesion to and invasion of host cells are essential steps involved in the infection and dissemination of pathogens. Furthermore, pathogens use their surface molecules to bind to host extracellular matrix components to establish infection. Here, we report the characterization of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of P. brasiliensis as an adhesin, which can be related to fungus adhesion and invasion. The P. brasiliensis GAPDH was overexpressed in Escherichia coli, and polyclonal antibody against this protein was obtained. By immunoelectron microscopy and Western blot analysis, GAPDH was detected in the cytoplasm and the cell wall of the yeast phase of P. brasiliensis. The recombinant GAPDH was found to bind to fibronectin, laminin, and type I collagen in ligand far-Western blot assays. Of special note, the treatment of P. brasiliensis yeast cells with anti-GAPDH polyclonal antibody and the incubation of pneumocytes with the recombinant protein promoted inhibition of adherence and internalization of P. brasiliensis to those in vitro-cultured cells. These observations indicate that the cell wall-associated form of the GAPDH in P. brasiliensis could be involved in mediating binding of fungal cells to fibronectin, type I collagen, and laminin, thus contributing to the adhesion of the microorganism to host tissues and to the dissemination of infection.

Barbosa, Monica Santiago; Bao, Sonia Nair; Andreotti, Patricia Ferrari; de Faria, Fabricia P.; Felipe, Maria Sueli S.; dos Santos Feitosa, Luciano; Mendes-Giannini, Maria Jose Soares; de Almeida Soares, Celia Maria

2006-01-01

42

Characterization of PbPga1, an antigenic GPI-protein in the pathogenic fungus Paracoccidioides brasiliensis.  

PubMed

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis (PCM), one of the most prevalent mycosis in Latin America. P. brasiliensis cell wall components interact with host cells and influence the pathogenesis of PCM. Cell wall components, such as glycosylphosphatidylinositol (GPI)-proteins play a critical role in cell adhesion and host tissue invasion. Although the importance of GPI-proteins in the pathogenesis of other medically important fungi is recognized, little is known about their function in P. brasiliensis cells and PCM pathogenesis. We cloned the PbPga1 gene that codifies for a predicted GPI-anchored glycoprotein from the dimorphic pathogenic fungus P. brasiliensis. PbPga1 is conserved in Eurotiomycetes fungi and encodes for a protein with potential glycosylation sites in a serine/threonine-rich region, a signal peptide and a putative glycosylphosphatidylinositol attachment signal sequence. Specific chicken anti-rPbPga1 antibody localized PbPga1 on the yeast cell surface at the septum between the mother cell and the bud with stronger staining of the bud. The exposure of murine peritoneal macrophages to rPbPga1 induces TNF-? release and nitric oxide (NO) production by macrophages. Furthermore, the presence of O-glycosylation sites was demonstrated by ?-elimination under ammonium hydroxide treatment of rPbPga1. Finally, sera from PCM patients recognized rPbPga1 by Western blotting indicating the presence of specific antibodies against rPbPga1. In conclusion, our findings suggest that the PbPga1gene codifies for a cell surface glycoprotein, probably attached to a GPI-anchor, which may play a role in P. brasiliensis cell wall morphogenesis and infection. The induction of inflammatory mediators released by rPbPga1 and the reactivity of PCM patient sera toward rPbPga1 imply that the protein favors the innate mechanisms of defense and induces humoral immunity during P. brasiliensis infection. PMID:23024763

Valim, Clarissa X R; Basso, Luiz Roberto; dos Reis Almeida, Fausto B; Reis, Thaila Fernanda; Damásio, André Ricardo Lima; Arruda, Luisa Karla; Martinez, Roberto; Roque-Barreira, Maria Cristina; Oliver, Constance; Jamur, Maria Célia; Coelho, Paulo Sergio Rodrigues

2012-09-14

43

Characterization of gp70 and Anti-gp70 Monoclonal Antibodies in Paracoccidioides brasiliensis Pathogenesis  

Microsoft Academic Search

Paracoccidioidomycosis (PCM) is a systemic granulomatous mycosis whose agent is Paracoccidioides bra- siliensis. In the culture supernatant, the fungus expresses glycoproteins of from 13 to 148 kDa. A cell surface glycoprotein of 43 kDa is the major antigenic component of P. brasiliensis. Another expressed glycoprotein, gp70, is recognized by 96% of sera from PCM patients and is able to induce

Daniela de Mattos Grosso; Sandro Rogerio de Almeida; Mario Mariano; Jose Daniel Lopes

2003-01-01

44

Characterization of Paracoccidioides brasiliensis PbDfg5p, a cell-wall protein implicated in filamentous growth.  

PubMed

The dimorphic fungus Paracoccidioides brasiliensis is the causative agent of the most frequent systemic mycosis in Latin America. In humans, infection starts by inhalation of fungal propagules, which reach the pulmonary epithelium and differentiate into the yeast parasitic phase. Here we describe the characterization of a Dfg5p (defective for filamentous growth) homologue of P. brasiliensis, a predictable cell wall protein, first identified in Saccharomyces cerevisiae. The protein, the cDNA and genomic sequences were analysed. The cloned cDNA was expressed in Escherichia coli and the purified rPbDfg5p was used to obtain polyclonal antibodies. Immunoelectron microscopy and biochemical studies demonstrated the presence of PbDfg5p in the fungal cell wall. Enzymatic treatments identified PbDfg5p as a beta-glucan linked protein that undergoes N-glycosylation. The rPbDfg5p bound to extracellular matrix components, indicating that those interactions could be important for initial steps leading to P. brasiliensis attachment and colonization of host tissues. PMID:18098122

da Silva Castro, Nadya; Barbosa, Mônica Santiago; Maia, Zilma Alves; Báo, Sonia Nair; Felipe, Maria Sueli Soares; Santana, Jaime Martins; Soares Mendes-Giannini, Maria José; Pereira, Maristela; de Almeida Soares, Célia Maria

2008-02-01

45

Detection of Paracoccidioides brasiliensis in Tissue Samples by a Nested PCR Assay  

PubMed Central

A nested PCR assay for the detection of Paracoccidioides brasiliensis DNA was evaluated, using a sequence of the immunogenic gp43 gene as a target. This gene encodes an outer membrane protein unique to this dimorphic fungus. DNA from six clinical isolates and the ATCC strain 60885 of P. brasiliensis, as well as DNA from closely related fungi, was examined to determine detection limits and cross-reactions. PCR was done on DNA extracts of lung homogenates from 23 experimentally P. brasiliensis-infected and two uninfected BALB/c mice and from 20 Histoplasma capsulatum-infected ICR mice. The results were compared to quantitative cultures. A detection limit of 0.5 fg of specific DNA was determined using cloned plasmid DNA. In all seven P. brasiliensis isolates, the expected 196-bp nested PCR product was found. Their sequences were 100% identical to the gp43 gene sequence in GenBank. DNA extracts of all other, related fungi were negative. The PCR assay was positive in 21 out of 23 culture-positive lung homogenates with concentrations of 1 × 103 to 1.3 × 107 CFU of P. brasiliensis per g of lung. Uninfected BALB/c mice and H. capsulatum-infected mice samples gave negative results. The high sensitivity and specificity of this new nested PCR assay for the detection of P. brasiliensis in tissue samples were demonstrated. The assay may be useful for diagnosis in human tissue samples.

Bialek, Ralf; Ibricevic, Aida; Aepinus, Christian; Najvar, Laura K.; Fothergill, Annette W.; Knobloch, Jurgen; Graybill, John R.

2000-01-01

46

T-Cell Recognition of Paracoccidioides brasiliensis gp43Derived Peptides in Patients with Paracoccidioidomycosis and Healthy Individuals  

Microsoft Academic Search

Vaccines with synthetic peptides induce the immune response to epitopes that bind to several HLA alleles. By using a TEPITOPE algorithm, we selected and analyzed the T-cell responses of peripheral blood mono- nuclear cells from 29 paracoccidioidomycosis (PCM) patients to peptides of the immunodominant gp43 antigen of Paracoccidioides brasiliensis, the causative agent of PCM. Paracoccidioidomycosis (PCM) is caused by the

Leo Kei Iwai; M. Yoshida; A. Sadahiro; W. R. da Silva; M. L. Marin; A. C. Goldberg; M. A. Juliano; L. Juliano; M. A. Shikanai-Yasuda; J. Kalil; E. Cunha-Neto; L. R. Travassos

2007-01-01

47

Activation of the alternative complement pathway in canine normal serum by Paracoccidioides brasiliensis  

PubMed Central

The dimorphic fungus Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, a human granulomatous disease. Recently the first case of natural disease in dogs was reported. The complement system is an important effector component of humoral immunity against infectious agents. Therefore, the aim of this study was to evaluate the activation of the dog alternative complement pathway by P. brasiliensis. Initially, the ability of erythrocytes of guinea pig, rabbit, sheep, chicken and swine to activate the dog alternative pathway was evaluated. The guinea pig erythrocytes showed the greatest capacity to activate dog alternative pathway. The alternative (AH50) hemolytic activity was evaluated in 27 serum samples from healthy dogs and the mean values were 87.2 AH50/ml. No significant differences were observed in relation to sex and age. The alternative pathway activation by P. brasiliensis was higher in serum samples from adult dogs when compared to puppies and aged dogs (p ? 0.05). This is the first report of dog alternative complement pathway activation by P. brasiliensis and suggests that it may play a protective role in canine paracoccidioidomycosis.

Bianchini, A.A.C.; Petroni, T.F.; Fedatto, P.F.; Bianchini, R.R.; Venancio, E.J.; Itano, E.N.; Ono, M.A.

2009-01-01

48

Electrophoretic Karyotypes and Genome Sizing of the Pathogenic Fungus Paracoccidioides brasiliensis  

PubMed Central

Here we present the karyotype analysis and genome sizing of Paracoccidioides brasiliensis, a pathogen refractory to conventional genetic analysis. We have established pulsed-field gel electrophoresis (PFGE) conditions to resolve the high-molecular-weight chromosomal bands of two clinical isolates of P. brasiliensis. Both isolates showed four megabase-sized bands, ranging from 2.0 to 10.0 Mbp. Significant differences in chromosome sizes and in the chromosomal location of genes for the gp43 antigen and chitin synthase were found. Different technical approaches were employed to estimate the DNA content and to define the ploidy of P. brasiliensis. An estimated genome size in the range of 45.7 to 60.9 Mbp was provided by the analysis of data generated by measuring the amplitude of fluorescence intensity of DAPI (4?,6-diamidino-2-phenylindole)-stained nuclei (by confocal microscopy). The nuclear genome size estimated by confocal microscopy is twice that estimated by the average sum of the molecular weight of chromosome-sized DNA molecules by PFGE, suggesting that each separated P. brasiliensis chromosomal band is diploid.

Nogueira Cano, Maria Isabel; Cisalpino, Patricia Silva; Galindo, Ivan; Ramirez, Jose Luiz; Mortara, Renato Arruda; da Silveira, Jose Franco

1998-01-01

49

Inhibition of PbGP43 Expression May Suggest that gp43 is a Virulence Factor in Paracoccidioides brasiliensis  

PubMed Central

Glycoprotein gp43 is an immunodominant diagnostic antigen for paracoccidioidomycosis caused by Paracoccidioides brasiliensis. It is abundantly secreted in isolates such as Pb339. It is structurally related to beta-1,3-exoglucanases, however inactive. Its function in fungal biology is unknown, but it elicits humoral, innate and protective cellular immune responses; it binds to extracellular matrix-associated proteins. In this study we applied an antisense RNA (aRNA) technology and Agrobacterium tumefaciens-mediated transformation to generate mitotically stable PbGP43 mutants (PbGP43 aRNA) derived from wild type Pb339 to study its role in P. brasiliensis biology and during infection. Control PbEV was transformed with empty vector. Growth curve, cell vitality and morphology of PbGP43 aRNA mutants were indistinguishable from those of controls. PbGP43 expression was reduced 80–85% in mutants 1 and 2, as determined by real time PCR, correlating with a massive decrease in gp43 expression. This was shown by immunoblotting of culture supernatants revealed with anti-gp43 mouse monoclonal and rabbit polyclonal antibodies, and also by affinity-ligand assays of extracellular molecules with laminin and fibronectin. In vitro, there was significantly increased TNF-? production and reduced yeast recovery when PbGP43 aRNA1 was exposed to IFN-?-stimulated macrophages, suggesting reduced binding/uptake and/or increased killing. In vivo, fungal burden in lungs of BALB/c mice infected with silenced mutant was negligible and associated with decreased lung ???10 and IL-6. Therefore, our results correlated low gp43 expression with lower pathogenicity in mice, but that will be definitely proven when PbGP43 knockouts become available. This is the first study of gp43 using genetically modified P. brasiliensis.

Torres, Isaura; Hernandez, Orville; Tamayo, Diana; Munoz, Jose F.; Leitao, Natanael P.; Garcia, Ana M.; Restrepo, Angela

2013-01-01

50

Inhibition of PbGP43 expression may suggest that gp43 is a virulence factor in Paracoccidioides brasiliensis.  

PubMed

Glycoprotein gp43 is an immunodominant diagnostic antigen for paracoccidioidomycosis caused by Paracoccidioides brasiliensis. It is abundantly secreted in isolates such as Pb339. It is structurally related to beta-1,3-exoglucanases, however inactive. Its function in fungal biology is unknown, but it elicits humoral, innate and protective cellular immune responses; it binds to extracellular matrix-associated proteins. In this study we applied an antisense RNA (aRNA) technology and Agrobacterium tumefaciens-mediated transformation to generate mitotically stable PbGP43 mutants (PbGP43 aRNA) derived from wild type Pb339 to study its role in P. brasiliensis biology and during infection. Control PbEV was transformed with empty vector. Growth curve, cell vitality and morphology of PbGP43 aRNA mutants were indistinguishable from those of controls. PbGP43 expression was reduced 80-85% in mutants 1 and 2, as determined by real time PCR, correlating with a massive decrease in gp43 expression. This was shown by immunoblotting of culture supernatants revealed with anti-gp43 mouse monoclonal and rabbit polyclonal antibodies, and also by affinity-ligand assays of extracellular molecules with laminin and fibronectin. In vitro, there was significantly increased TNF-? production and reduced yeast recovery when PbGP43 aRNA1 was exposed to IFN-?-stimulated macrophages, suggesting reduced binding/uptake and/or increased killing. In vivo, fungal burden in lungs of BALB/c mice infected with silenced mutant was negligible and associated with decreased lung ??-10 and IL-6. Therefore, our results correlated low gp43 expression with lower pathogenicity in mice, but that will be definitely proven when PbGP43 knockouts become available. This is the first study of gp43 using genetically modified P. brasiliensis. PMID:23874627

Torres, Isaura; Hernandez, Orville; Tamayo, Diana; Muñoz, Jose F; Leitão, Natanael P; García, Ana M; Restrepo, Angela; Puccia, Rosana; McEwen, Juan G

2013-07-11

51

Early Endosome Antigen 1 (EEA1) decreases in macrophages infected with Paracoccidioides brasiliensis.  

PubMed

Abstract Paracoccidioidomycosis (PCM) is a chronic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis, endemic in Latin America. P. brasiliensis has been observed in epithelial cells in vivo and in vitro, as well as within the macrophages. The identification of the mechanism by which it survives within the host cell is fertile ground for the discovery of its pathogenesis since this organism has the ability to induce its own endocytosis in epithelial cells and most likely in macrophages. The study of the expression of endocytic proteins pathway and co-localization of microorganisms enable detection of the mechanism by which microorganisms survive within the host cell. The aim of this study was to evaluate the expression of the endocytic protein EEA1 (early endosome antigen 1) in macrophages infected with P. brasiliensis. For detection of EEA1, three different techniques were employed: immunofluorescence, real-time polymerase chain reaction (PCR) and immunoblotting. In the present study, decreased expression of EEA1 as well as the rearrangement of the actin was observed when the fungus was internalized, confirming that the input mechanism of the fungus in macrophages occurs through phagocytosis. PMID:23566224

Voltan, Aline Raquel; Sardi, Janaina De Cassia Orlandi; Soares, Christiane Pienna; Pelajo Machado, Marcelo; Fusco Almeida, Ana Marisa; Mendes-Giannini, Maria José Soares

2013-04-08

52

Activity of compounds isolated from Baccharis dracunculifolia D.C. (Asteraceae) against Paracoccidioides brasiliensis.  

PubMed

Paracoccidioidomycosis is a prevalent systemic mycosis in Latin America which requires prolonged treatment with highly toxic antifungals. Baccharis dracunculifolia is a medicinal plant in Brazil that is a candidate in the search for new drugs. Fractions of the hexanic extracts were obtained using chromatographic procedures and assessed using an antifungal assay with Paracoccidioides brasiliensis (Pb18), tumor cell lines and amastigote forms of Leishmania, L. amazonensis. Four compounds were isolated, i.e., ursolic acid (1), methyl linolenate (2), caryophyllene oxide (3), and trans-nerolidol (4). Compounds 2, 3 and 4 displayed antifungal activity against four isolates of Paracocci dioides with MIC values ranging from 3.9-250 ?g/ml. Only caryophyllene oxide showed differences in the MIC values against Pb18 when the medium was supplemented with ergosterol, which suggested that the compound interacts with ergosterol. Ursolic acid was active in the cytotoxic assays and showed leishmanicidal activity. Scanning electron microscopy demonstrated that compounds 2, 3 and 4 decreased the cell size and produced an irregular cell wall surface on P. brasiliensis cells. The present results showed the biological activities of the isolated compounds and revealed that these compounds may affect the cell surface and growth of P. brasiliensis isolates. PMID:22548242

Johann, Susana; Oliveira, Flávia Beraldo; Siqueira, Ezequias P; Cisalpino, Patricia S; Rosa, Carlos A; Alves, Tânia M A; Zani, Carlos L; Cota, Betania B

2012-05-02

53

Immunological Basis for the Gender Differences in Murine Paracoccidioides brasiliensis Infection  

PubMed Central

This study aimed to investigate the immunological mechanisms involved in the gender distinct incidence of paracoccidioidomycosis (pcm), an endemic systemic mycosis in Latin America, which is at least 10 times more frequent in men than in women. Then, we compared the immune response of male and female mice to Paracoccidioides brasiliensis infection, as well as the influence in the gender differences exerted by paracoccin, a P. brasiliensis component with carbohydrate recognition property. High production of Th1 cytokines and T-bet expression have been detected in the paracoccin stimulated cultures of spleen cells from infected female mice. In contrast, in similar experimental conditions, cells from infected males produced higher levels of the Th2 cytokines and expressed GATA-3. Macrophages from male and female mice when stimulated with paracoccin displayed similar phagocytic capability, while fungicidal activity was two times more efficiently performed by macrophages from female mice, a fact that was associated with 50% higher levels of nitric oxide production. In order to evaluate the role of sexual hormones in the observed gender distinction, we have utilized mice that have been submitted to gonadectomy followed by inverse hormonal reconstitution. Spleen cells derived from castrated males reconstituted with estradiol have produced higher levels of IFN-? (1291±15 pg/mL) and lower levels of IL-10 (494±38 pg/mL), than normal male in response to paracoccin stimulus. In contrast, spleen cells from castrated female mice that had been treated with testosterone produced more IL-10 (1284±36 pg/mL) and less IFN-? (587±14 pg/mL) than cells from normal female. In conclusion, our results reveal that the sexual hormones had a profound effect on the biology of immune cells, and estradiol favours protective responses to P. brasiliensis infection. In addition, fungal components, such as paracoccin, may provide additional support to the gender dimorphic immunity that marks P. brasiliensis infection.

Pinzan, Camila Figueiredo; Ruas, Luciana Pereira; Casabona-Fortunato, Analia Sulamita; Carvalho, Fernanda Caroline; Roque-Barreira, Maria-Cristina

2010-01-01

54

Exocellular proteolytic activity of Paracoccidioides brasiliensis: cleavage of components associated with the basement membrane.  

PubMed

We have previously characterized an exocellular serine-thiol proteinase activity in Paracoccidioides brasiliensis, using as substrates peptides analogous of the internally quenched fluorogenic peptide Abz-MKRLTL-EDDnp. In this communication, detection of maximal proteinase activity in the culture supernatant fluids followed the abrupt increase in the medium pH, owing to the accumulation of ammonia generated by urease activity. Culture supernatant fluids collected at the peak of proteinase activity against Abz-MRKLTL-EDDnp were able to cleave components of the basal membrane of the extracellular matrix (EM), including laminin, fibronectin, collagen type IV and proteoglycans, and the proteolytic activity was selectively inhibited both by PMSF and p-HMB (sodium 7-hydroxymercuribenzoate), which are also specific inhibitors of the serine-thiol proteinase. Human collagen I, bovine fibrinogen, human immunoglobulin G, BSA or P. brasiliensis gp43 were resistant to proteolysis. The kinetics of appearance of the proteinase activity against EM substrates coincided with that of proteolysis of Abz-MKRLTL-EDDnp. Moreover, chromatographic fractions of culture supernatants containing the serine-thiol proteinase at high specific activity were also active against EM substrates. These data suggest the involvement of this enzyme activity in the degradation of the basement membrane, which is the first step for fungal tissue invasion. PMID:10075506

Puccia, R; Carmona, A K; Gesztesi, J L; Juliano, L; Travassos, L R

1998-10-01

55

Expression of Antibodies Directed to Paracoccidioides brasiliensis Glycosphingolipids during the Course of Paracoccidioidomycosis Treatment?  

PubMed Central

Paracoccidioidomycosis (PCM) is a granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis. The immunoglobulin classes and isotypes of antibodies directed to acidic glycosphingolipids (GSLs) and glucosylceramide of P. brasiliensis were determined by enzyme-linked immunosorbent assay of sera from 31 PCM patients. The reactivities of 38 serum samples were analyzed by considering the stage of treatment: before antifungal treatment (n = 10), during 1 to 4 months of treatment (T1-4; n = 9), during 5 to 12 months of treatment (T5-12; n = 9), and posttreatment (PT; n = 10). Sera from healthy subjects (n = 12) were used as controls. Only the GSL Pb-1 antigen, which presents the carbohydrate structure Galf?1-6(Man?1-3)Man?1, was reactive with the PCM patient sera. The PCM patient sera did not react with Pb-2, which lacks the Galf residue and which is considered the biosynthetic precursor of Pb-1, indicating that the Galf residue is essential for antibody reactivity. The Pb-1 glycolipid from nontreated patients elicited a primary immune response with immunoglobulin M (IgM) production and subsequent switching to IgG1 production. The IgG1 titer increased after the start of antifungal treatment (T1-4 group), and general decreases in the anti-Pb-1 antibody titers were observed after 5 months of treatment (T5-12 and PT groups). The Pb-1 antigen, an acidic GSL with terminal Galf residue, has potential application as an elicitor of the host immune response in patients with PCM.

Bertini, Silvio; Colombo, Arnaldo L.; Takahashi, Helio K.; Straus, Anita H.

2007-01-01

56

Interleukin-15 augments oxidative metabolism and fungicidal activity of human monocytes against Paracoccidioides brasiliensis.  

PubMed

Interleukin (IL)-15 is a pleiotropic cytokine that regulates the proliferation and survival of many cell types. IL-15 is produced by monocytes and macrophages against infectious agents and plays a pivotal role in innate and adaptive immune responses. This study analyzed the effect of IL-15 on fungicidal activity, oxidative metabolism and cytokine production by human monocytes challenged in vitro with Paracoccidioides brasiliensis (Pb18), the agent of paracoccidioidomycosis. Peripheral blood monocytes were pre-incubated with IL-15 and then challenged with Pb18. Fungicidal activity was assessed by viable fungi recovery from cultures after plating on brain-heart infusion-agar. Superoxide anion (O??), hydrogen peroxide (H?O?), tumour necrosis factor-alpha (TNF-?), IL-6, IL-15 and IL-10 production by monocytes were also determined. IL-15 enhanced fungicidal activity against Pb18 in a dose-dependent pattern. This effect was abrogated by addition of anti-IL-15 monoclonal antibody. A significant stimulatory effect of IL-15 on O?? and H?O? release suggests that fungicidal activity was dependent on the activation of oxidative metabolism. Pre-treatment of monocytes with IL-15 induced significantly higher levels of TNF-?, IL-10 and IL-15 production by cells challenged with the fungus. These results suggest a modulatory effect of IL-15 on pro and anti-inflammatory cytokine production, oxidative metabolism and fungicidal activity of monocytes during Pb18 infection. PMID:21120355

Bannwart, Camila Ferreira; Martins, Rosana A Rodrigues; Nakaira-Takahashi, Erika; Dias-Melício, Luciane A; Soares, Angela M V Campos; Peraçoli, Maria Terezinha S

2010-11-01

57

Prophylactic and Therapeutic Vaccination Using Dendritic Cells Primed with Peptide 10 Derived from the 43-Kilodalton Glycoprotein of Paracoccidioides brasiliensis  

PubMed Central

Vaccination with peptide 10 (P10), derived from the Paracoccidioides brasiliensis glycoprotein 43 (gp43), induces a Th1 response that protects mice in an intratracheal P. brasiliensis infection model. Combining P10 with complete Freund's adjuvant (CFA) or other adjuvants further increases the peptide's antifungal effect. Since dendritic cells (DCs) are up to 1,000-fold more efficient at activating T cells than CFA, we examined the impact of P10-primed bone-marrow-derived DC vaccination in mice. Splenocytes from mice immunized with P10 were stimulated in vitro with P10 or P10-primed DCs. T cell proliferation was significantly increased in the presence of P10-primed DCs compared to the peptide. The protective efficacy of P10-primed DCs was studied in an intratracheal P. brasiliensis model in BALB/c mice. Administration of P10-primed DCs prior to (via subcutaneous vaccination) or weeks after (via either subcutaneous or intravenous injection) P. brasiliensis infection decreased pulmonary damage and significantly reduced fungal burdens. The protective response mediated by the injection of primed DCs was characterized mainly by an increased production of gamma interferon (IFN-?) and interleukin 12 (IL-12) and a reduction in IL-10 and IL-4 compared to those of infected mice that received saline or unprimed DCs. Hence, our data demonstrate the potential of P10-primed DCs as a vaccine capable of both the rapid protection against the development of serious paracoccidioidomycosis or the treatment of established P. brasiliensis disease.

Magalhaes, A.; Ferreira, K. S.; Almeida, S. R.; Nosanchuk, J. D.; Travassos, L. R.

2012-01-01

58

Detection of the basement membrane-degrading proteolytic activity of Paracoccidioides brasiliensis after SDS-PAGE using agarose overlays containing Abz-MKALTLQ-EDDnp.  

PubMed

We have characterized, in the Paracoccidioides brasiliensis yeast phase, an exocellular SH-dependent serine proteinase activity against Abz-MKRLTL-EDDnp and analogous fluorescent-quenched peptides, and showed that it is also active against constituents of the basement membrane in vitro. In the present study, we separated the components of P. brasiliensis culture filtrates by electrophoresis and demonstrated that the serine-thiol exocellular proteinase has a diffuse and heterogeneous migration by SDS-PAGE, localizing in a region between 69 and 43 kDa. The hydrolytic activity was demonstrable after SDS-PAGE using buffered agarose overlays of Abz-MKALTLQ-EDDnp, following incubation at 37 degrees C, and detection of fluorescent bands with a UV transilluminator. Hydrolysis was more intense when incubation was carried out at basic pH, and was completely inhibited with 2.5 mM PMSF and partially with sodium 7-hydroxymercuribenzoate (2.5 mM p-HMB), suggesting its serine-thiol nature. A proteolytic band with similar characteristics was observed in conventional gelatin zymograms, but could not be correlated with a silver-stained component. Detection of the serine-thiol proteinase in substrate gels after SDS-PAGE provides a useful way of monitoring purification of the basement membrane degrading enzyme. PMID:10412577

Puccia, R; Juliano, M A; Juliano, L; Travassos, L R; Carmona, A K

1999-05-01

59

Evaluation of Paracoccidioides brasiliensis infection by gp 43 intradermal test in rural settlements in Central-West Brazil.  

PubMed

Epidemiological studies of paracoccidioidomycosis have been based on surveys achieved with intradermal tests, and paracoccidioidin is the most common antigen used in most cases. The glycoprotein of 43-kDa (gp43) has been used in intradermal tests. It is the most antigenic component of Paracoccidioides brasiliensis, and it provides greater specificity to evaluate infection for this fungus. In this study, the prevalence of P. brasiliensis infection was estimated with intradermal tests involving gp43 for 695 people in rural Central-West Brazil. The infection rate was 45.8 % (95 % CI = 42.1-49.5), and the average age of those infected was 45.8 ± 18.2 years. The prevalence did not show gender-based differences but increased with age. The results demonstrate the importance of P. brasiliensis infection in rural settlements and the early exposure of children in the region to the fungus. Despite the high antigenicity and specificity of gp43, its usage must be standardized, so that epidemiological surveys will be comparable and more accurately reflect P. brasiliensis infection in endemic areas. PMID:23612867

Marques, Ana Paula da C; Oliveira, Sandra Maria V L; Rezende, Grazielli R; Melo, Dayane A; Fernandes-Fitts, Sonia M; Pontes, Elenir Rose J C; Bonecini-Almeida, Maria da Glória; Camargo, Zoilo P; Paniago, Anamaria M M

2013-04-24

60

Identification of a metallopeptidase with TOP-like activity in Paracoccidioides brasiliensis, with increased expression in a virulent strain.  

PubMed

Paracoccidioidomycosis (PCM), caused by the pathogenic fungus Paracoccidioides brasiliensis, is a systemic mycosis with severe acute and chronic forms. The pathology of PCM is not completely understood, and the role of proteases in the infection is not clearly defined. In this report, we describe a metallopeptidase activity in P. brasiliensis total and cytosolic protein extracts similar to that of mammalian thimet oligopeptidase (TOP). The analogous enzyme was suggested by analysis of P. brasiliensis genome databank and by hydrolytic activity of the FRET peptide Abz-GFSPFRQ-EDDnp which was completely inhibited by o-phenanthrolin and significantly inhibited by the TOP inhibitor, JA-2. This activity was also partially inhibited by IgG purified from patients with PCM, but not from normal individuals. As shown by high-performance liquid chromatography (HPLC), the hydrolysis of bradykinin had the same pattern as that of mammalian TOP, and anti-mammalian TOP antibodies significantly inhibited fungal cytosolic peptidase activity. Moreover, anti-mammalian TOP antibodies recognized a component of 80 kDa on fungal cytosol. A P. brasiliensis virulent isolate showed higher gene expression and TOP-like peptidase activity than a non-virulent strain. The release of enzyme following fungal lysis would be consistent with host antibody production and may have a role in the pathogenesis, inflammation and further development of the mycosis. PMID:21728754

Gravi, Ellen T; Paschoalin, Thaysa; Dias, Bianca R; Moreira, Dayson F; Belizario, José E; Oliveira, Vitor; Carmona, Adriana K; Juliano, Maria A; Travassos, Luiz R; Rodrigues, Elaine G

2011-07-05

61

The Homeostasis of Iron, Copper, and Zinc in Paracoccidioides Brasiliensis, Cryptococcus Neoformans Var. Grubii, and Cryptococcus Gattii: A Comparative Analysis  

PubMed Central

Iron, copper, and zinc are essential for all living organisms. Moreover, the homeostasis of these metals is vital to microorganisms during pathogenic interactions with a host. Most pathogens have developed specific mechanisms for the uptake of micronutrients from their hosts in order to counteract the low availability of essential ions in infected tissues. We report here an analysis of genes potentially involved in iron, copper, and zinc uptake and homeostasis in the fungal pathogens Paracoccidioides brasiliensis, Cryptococcus neoformans var. grubii, and Cryptococcus gattii. Although prior studies have identified certain aspects of metal regulation in Cryptococcus species, little is known regarding the regulation of these elements in P. brasiliensis. We also present amino acid sequences analyses of deduced proteins in order to examine possible conserved domains. The genomic data reveals, for the first time, genes associated to iron, copper, and zinc assimilation and homeostasis in P. brasiliensis. Furthermore, analyses of the three fungal species identified homologs to genes associated with high-affinity uptake systems, vacuolar and mitochondrial iron storage, copper uptake and reduction, and zinc assimilation. However, homologs to genes involved in siderophore production were only found in P. brasiliensis. Interestingly, in silico analysis of the genomes of P. brasiliensis Pb01, Pb03, and Pb18 revealed significant differences in the presence and/or number of genes involved in metal homeostasis, such as in genes related to iron reduction and oxidation. The broad analyses of the genomes of P. brasiliensis, C. neoformans var. grubii, and C. gattii for genes involved in metal homeostasis provide important groundwork for numerous interesting future areas of investigation that are required in order to validate and explore the function of the identified genes and gene pathways.

Silva, Mirelle Garcia; Schrank, Augusto; Bailao, Elisa Flavia L.C.; Bailao, Alexandre Melo; Borges, Clayton Luiz; Staats, Charley Christian; Parente, Juliana Alves; Pereira, Maristela; Salem-Izacc, Silvia Maria; Mendes-Giannini, Maria Jose Soares; Oliveira, Rosely Maria Zancope; Silva, Livia Kmetzsch Rosa e; Nosanchuk, Joshua D.; Vainstein, Marilene Henning; de Almeida Soares, Celia Maria

2011-01-01

62

Morphological and structural changes in lung tissue infected by Paracoccidioides brasiliensis: FTIR photoacoustic spectroscopy and histological analysis.  

PubMed

This study evaluated physical, chemical and morphological changes in lungs of mice infected with Paracoccidioides brasiliensis. The animals were inoculated with 0.1 mL of fungal suspension of the P. brasiliensis 18 isolate and were euthanized 1, 2, 4 and 8 weeks after inoculation. The upper left lobe of the lung was isolated, fixed and processed for paraffin embedding. The sections were stained with H&E for histopathological study, with Gomori-Grocott to locate and identify the fungus, and with TUNEL immunostaining to detect the occurrence of programmed cell death. The lower and middle right lobes were analyzed by Fourier Transform Infrared Photoacoustic Spectrocopy (FTIR-PAS) to investigate physical and chemical features of the infected lungs. The results showed that lungs infected by P. brasiliensis underwent structural changes that varied according to the time period analyzed, and that changes in the absorption bands of different chemical groups resulted from these morphological changes. The results suggest that the combination of FTIR-PAS spectroscopy with morphological evaluation is an effective procedure for the study of paracoccidioidomycosis, one of the most important systemic mycoses that can damage the lung architecture and consequently impair the respiratory function. PMID:23742212

Morato, Edilaine M; Morais, Gutierrez R; Sato, Francielle; Medina, Antonio N; Svidzinski, Terezinha I E; Baesso, Mauro L; Hernandes, Luzmarina

2013-07-08

63

Granuloma formation in vitro requires B-1 cells and is modulated by Paracoccidioides brasiliensis gp43 antigen.  

PubMed

The mechanisms that determine granuloma formation and the significance of this type of inflammatory response in the pathogenesis of fungal diseases such as paracoccidioidomycosis are far from fully understood. We developed a granuloma model in vitro using beads to evaluate the role of isolated mouse peritoneal macrophages and B-1 cells. We also investigated granuloma formation in the presence of gp43, the main antigenic component of Paracoccidioides brasiliensis, which is secreted exocellularly. To determine whether B-1 cells, macrophages, or both, participate in granuloma formation, peritoneal cells from Xid mice, which lack B-1 cells, were used. Granuloma-like structures were not formed with Xid peritoneal cells or with cells from wild type mice that had their peritoneal and pleural cavities irradiated before the cultures were established. Granulomas were observed either when total adherent peritoneal cells or when isolated B-1 cells were added to macrophage cultures. The data strongly suggest that an interaction of B-1 cells and macrophages plays an important role in granuloma-like formation in this experimental model and that the presence of gp43 strongly stimulates this response. PMID:16500129

Vigna, Ana Flávia; Almeida, Sandro Rogério; Xander, Patricia; Freymüller, Edna; Mariano, Mario; Lopes, José Daniel

2006-01-17

64

C-Npys ( S-3-nitro-2-pyridinesulfenyl) and peptide derivatives can inhibit a serine-thiol proteinase activity from Paracoccidioides brasiliensis  

Microsoft Academic Search

The inhibitory capacity of C-Npys (S-[3-nitro-2-pyridinesulfenyl]) derivatives over thiol-containing serine proteases has never been tested. In the present work we used an extracellular serine-thiol proteinase activity from the fungal pathogen Paracoccidioides brasiliensis (PbST) to describe a potent inhibitory capacity of Bzl-C(Npys)KRLTL-NH2 and Bzl-MKRLTLC(Npys)-NH2. The assays were performed with PbST enriched upon affinity chromatography in a p-aminobenzamidine (pABA)-Sepharose column. Although PbST

Alisson L. Matsuo; Adriana K. Carmona; Luiz S. Silva; Carlos E. L. Cunha; Ernesto S. Nakayasu; Igor C. Almeida; Maria A. Juliano; Rosana Puccia

2007-01-01

65

Cell-free antigens from Paracoccidioides brasiliensis drive IL-4 production and increase the severity of paracoccidioidomycosis.  

PubMed

The thermally dimorphic fungus Paracoccidioides brasiliensis (Pb) is the causative agent of paracoccidioidomycosis (PCM), one of the most frequent systemic mycosis that affects the rural population in Latin America. PCM is characterized by a chronic inflammatory granulomatous reaction, which is consequence of a Th1-mediated adaptive immune response. In the present study we investigated the mechanisms involved in the immunoregulation triggered after a prior contact with cell-free antigens (CFA) during a murine model of PCM. The results showed that the inoculation of CFA prior to the infection resulted in disorganized granulomatous lesions and increased fungal replication in the lungs, liver and spleen, that paralleled with the higher levels of IL-4 when compared with the control group. The role of IL-4 in facilitating the fungal growth was demonstrated in IL-4-deficient- and neutralizing anti-IL-4 mAb-treated mice. The injection of CFA did not affect the fungal growth in these mice, which, in fact, exhibited a significant diminished amount of fungus in the tissues and smaller granulomas. Considering that in vivo anti-IL-4-application started one week after the CFA-inoculum, it implicates that IL-4-CFA-induced is responsible by the mediation of the observed unresponsiveness. Further, the characterization of CFA indicated that a proteic fraction is required for triggering the immunosuppressive mechanisms, while glycosylation or glycosphingolipids moieties are not. Taken together, our data suggest that the prior contact with soluble Pb antigens leads to severe PCM in an IL-4 dependent manner. PMID:21731741

Cavassani, Karen A; Tristao, Fabrine S M; Oliveira, Leandro L; Rocha, Fernanda A; Vancim, Jaqueline O; Moreira, Ana Paula; Campanelli, Ana Paula; Panagio, Luciano A; Milanezi, Cristiane M; Martinez, Roberto; Rossi, Marcos A; Silva, Joao S

2011-06-22

66

Response to oxidative stress in Paracoccidioides yeast cells as determined by proteomic analysis.  

PubMed

An efficient oxidative stress response is important to the fungal pathogen Paracoccidioides to survive within the human host. In this study, oxidative stress was mimicked by exposure of yeast cells to hydrogen peroxide (2 mM H2O2). To investigate the effect of H2O2 on the proteome of Paracoccidioides, we used a large scale 2-DE protein gel electrophoresis approach to analyze differentially expressed proteins/isoforms that were detected in early (2 h) and in late (6 h) oxidative stress treatments. All proteins/isoforms were grouped based on their functional categories that revealed a global activation of antioxidant enzymes, such as catalase, superoxide dismutase, cytochrome C peroxidase and thioredoxin. A view of the metabolic cell profile, as determined by proteomics, depicted a shift in the yeast cells metabolism as suggested by the activation of the pentose phosphate pathway, a great source of cellular reducing power in the form of NADPH. Additionally, in silico analyzes depicted 34 oxidoreductases proteins/isoforms putatively involved with defense against oxidative stress. Confirmatory assays of enzymatic activity, flow cytometry, transcript levels and NADPH measurements, produced data in agreement with proteomic analysis. PMID:23421979

de Arruda Grossklaus, Daciene; Bailão, Alexandre Melo; Vieira Rezende, Tereza Cristina; Borges, Clayton Luiz; de Oliveira, Milton Adriano Pelli; Parente, Juliana Alves; de Almeida Soares, Célia Maria

2013-02-17

67

Biochemical characterization of Paracoccidioides brasiliensis ?-1,3-glucanase Agn1p, and its functionality by heterologous Expression in Schizosaccharomyces pombe.  

PubMed

?-1,3-Glucan is present as the outermost layer of the cell wall in the pathogenic yeastlike (Y) form of Paracoccidioides brasiliensis. Based on experimental evidence, this polysaccharide has been proposed as a fungal virulence factor. To degrade ?-1,3-glucan and allow remodeling of the cell wall, ?-1,3-glucanase is required. Therefore, the study of this enzyme, its encoding gene, and regulatory mechanisms, might be of interest to understand the morphogenesis and virulence process in this fungus. A single gene, orthologous to other fungal ?-1,3-glucanase genes, was identified in the Paracoccidioides genome, and labeled AGN1. Transcriptional levels of AGN1 and AGS1 (?-1,3-glucan synthase-encoding gene) increased sharply when the pathogenic Y phase was cultured in the presence of 5% horse serum, a reported booster for cell wall ?-1,3-glucan synthesis in this fungus. To study the biochemical properties of P. brasiliensis Agn1p, the enzyme was heterologously overexpressed, purified, and its activity profile determined by means of the degradation of carboxymethyl ?-1,3-glucan (SCMG, chemically modified from P. brasiliensis ?-1,3-glucan), used as a soluble substrate for the enzymatic reaction. Inhibition assays, thin layer chromatography and enzymatic reactions with alternative substrates (dextran, starch, chitin, laminarin and cellulose), showed that Agn1p displays an endolytic cut pattern and high specificity for SCMG. Complementation of a Schizosaccharomyces pombe agn1? strain with the P. brasiliensis AGN1 gene restored the wild type phenotype, indicating functionality of the gene, suggesting a possible role of Agn1p in the remodeling of P. brasiliensis Y phase cell wall. Based on amino acid sequence, P. brasiliensis Agn1p, groups within the family 71 of fungal glycoside hydrolases (GH-71), showing similar biochemical characteristics to other members of this family. Also based on amino acid sequence alignments, we propose a subdivision of fungal GH-71 into at least five groups, for which specific conserved sequences can be identified. PMID:23825576

Villalobos-Duno, Héctor; San-Blas, Gioconda; Paulinkevicius, Maryan; Sánchez-Martín, Yolanda; Nino-Vega, Gustavo

2013-06-25

68

Mapping of the T-Cell Epitope in the Major 43-Kilodalton Glycoprotein of Paracoccidioides brasiliensis Which Induces a Th-1 Response Protective against Fungal Infection in BALB/c Mice  

PubMed Central

The 43-kDa glycoprotein of Paracoccidioides brasiliensis is the major diagnostic antigen of paracoccidioidomycosis, the prevalent systemic mycosis of Latin America. Apart from eliciting high antibody titers, gp43 is also immunodominant in delayed-type hypersensitivity reactions in infected animals and humans. The cellular immune response in mice to gp43 administered in complete Freund’s adjuvant involves CD4+ Th-1 lymphocytes, secreting gamma interferon (IFN-?) and interleukin 2 (IL-2) but not IL-4 and IL-10. The T-cell epitope of this antigen was mapped to a 15-amino-acid peptide (P10) based on lymphoproliferations with primed cells from three different haplotypes and on a computer-assisted protein analysis. The structural requirements of the T-cell epitope were determined by assaying a series of P10 analogous and truncated peptides. Only 12-mer or longer sequences were active, confirming presentation by major histocompatibility complex II. The HTLAIR inner core of P10 is the essential domain of the epitope, with various flanking regions possible. Immunization of mice with both gp43 and P10 led to vigorous protection against intratracheal challenge by virulent P. brasiliensis, with a >200-fold decrease in lung CFU and halting of dissemination to the spleen and liver. The protective effect of P10 is mainly attributed to an IFN-?-mediated cellular immune response. Unlike gp43, which induces an antibody response compatible with both Th-1 and Th-2 activation in infected BALB/c mice, P10 does not induce a humoral response. Protection by gp43 and P10 was characterized by a few well-demarcated lung granulomas with numerous nonviable yeast forms or resolved lesions with no detectable fungal cells.

Taborda, Carlos P.; Juliano, Maria A.; Puccia, Rosana; Franco, Marcello; Travassos, Luiz R.

1998-01-01

69

In Silico Prediction of Peptides Binding to Multiple HLA-DR Molecules Accurately Identifies Immunodominant Epitopes from gp43 of Paracoccidioides brasiliensis Frequently Recognized in Primary Peripheral Blood Mononuclear Cell Responses from Sensitized Individuals  

Microsoft Academic Search

One of the major drawbacks limiting the use of synthetic peptide vaccines in genetically distinct populations is the fact that different epitopes are recognized by T cells from individuals displaying distinct major histocompatibility complex molecules. Immunization of mice with peptide (181-195) from the immunodominant 43 kDa glycoprotein of Paracoccidioides brasiliensis (gp43), the causative agent of Paracoccidioidomycosis (PCM), conferred protection against

LEO KEI IWAI; MÁRCIA YOSHIDA; JOHN SIDNEY; MARIA APARECIDA SHIKANAI-YASUDA; ANNA CARLA GOLDBERG; MARIA APARECIDA JULIANO; JURGEN HAMMER; LUIZ JULIANO; ALESSANDRO SETTE; JORGE KALIL; LUIZ RODOLPHO TRAVASSOS; EDECIO CUNHA-NETO

70

Polymorphism in the flanking regions of the PbGP43 gene from the human pathogen Paracoccidioides brasiliensis: search for protein binding sequences and poly(A) cleavage sites  

Microsoft Academic Search

BACKGROUND: Paracoccidioides brasiliensis is a thermo-dimorphic fungus that causes paracoccidiodomycosis (PCM). Glycoprotein gp43 is the fungal main diagnostic antigen, which can also protect against murine PCM and interact with extracellular matrix proteins. It is structurally related to glucanases, however not active, and whose expression varies considerably. We have presently studied polymorphisms in the PbGP43 flanking regions to help understand such

Antonio A Rocha; Flávia V Morais; Rosana Puccia

2009-01-01

71

Transcription levels of CHS5 and CHS4 genes in Paracoccidioides brasiliensis mycelial phase, respond to alterations in external osmolarity, oxidative stress and glucose concentration.  

PubMed

The complete sequence of Paracoccidioides brasiliensis CHS5 gene, encoding a putative chitin synthase revealed a 5583nt open reading frame, interrupted by three introns of 82, 87 and 97bp (GenBank Accession No EF654132). The deduced protein contains 1861 amino acids with a predicted molecular weight of 206.9kDa. Both its large size and the presence of a N-terminal region of approx. 800 residues with a characteristic putative myosin motor-like domain, allow us to include PbrChs5 into class V fungal chitin synthases. Sequence analysis of over 4kb from the 5' UTR region in CHS5, revealed the presence of a previously reported CHS4 gene in P. brasiliensis, arranged in a head-to-head configuration with CHS5. A motif search in this shared region showed the presence of stress response elements (STREs), three binding sites for the transcription activators Rlm1p (known to be stimulated by hypo-osmotic stress) and clusters of Adr1 (related to glucose repression). A quantitative RT-PCR analysis pointed to changes in transcription levels for both genes following oxidative stress, alteration of external osmolarity and under glucose-repressible conditions, suggesting a common regulatory mechanism of transcription. PMID:19616626

Niño-Vega, Gustavo A; Sorais, Françoise; San-Blas, Gioconda

2009-07-17

72

Purification and Partial Characterization of a Paracoccidioides brasiliensis Protein with Capacity To Bind to Extracellular Matrix Proteins  

Microsoft Academic Search

Microorganisms adhere to extracellular matrix proteins by means of their own surface molecules. Paracoc- cidioides brasiliensis conidia have been shown to be capable of interacting with extracellular matrix proteins. We aimed at determining the presence of fungal proteins that could interact with extracellular matrix protein and, if found, attempt their purification and characterization. Various extracts were prepared from P. brasiliensis

Angel Gonzalez; Beatriz L. Gomez; S. Diez; Orville Hernandez; Angela Restrepo; Andrew J. Hamilton; Luz E. Cano

2005-01-01

73

Inhibitory effect of PGE(2) on the killing of Paracoccidioides brasiliensis by human monocytes can be reversed by cellular activation with cytokines.  

PubMed

Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, a deep mycosis endemic in Latin America. Studies to elucidate the host-parasite relationship in this mycosis have demonstrated that non-activated phagocytes fail to kill the etiologic agent. Investigations of human monocytes have shown that the lack of fungicidal activity is partially associated with the capacity of a high-virulence strain to induce PGE(2) release by these cells. This eicosanoid inhibits production of TNF-?, the cytokine involved in cell activation for release of H(2)O(2), the fungicidal metabolite. Cell priming with IFN-? was shown to partially reverse this inhibitory effect. In this study, we asked whether monocyte challenge with a low-virulence strain of this fungus would also result in PGE(2) release and consequently inhibition of antifungal activities. We also assessed whether PGE(2,) besides inhibiting production of TNF-?, a monocyte-activating cytokine, also affects IL-10. The latter, in contrast to TNF-? is a monocyte-suppressing cytokine. Finally, we evaluated whether priming cells with other cytokines, namely TNF-? and GM-CSF, could be more effective than IFN-? in reversing the PGE(2) inhibitory effect. The results revealed that the less virulent P. brasiliensis strain also induces human monocytes to release PGE(2). However, the inhibitory effect of PGE(2) was less pronounced when cells were challenged with this strain than with the more virulent one. It was also demonstrated that PGE(2), while inhibits TNF-? production, tends to increase IL-10 levels. Priming with GM-CSF or TNF-? was more effective than IFN-? in compensating for the inhibitory PGE(2) effect, since these cytokines induce cells to produce higher H(2)O(2) and TNF-? levels. PMID:22548241

Bordon-Graciani, Ana Paula; Dias-Melicio, Luciane Alarcão; Acorci-Valério, Michele Janegitz; Araujo, João Pessoa; de Campos Soares, Angela Maria Victoriano

2012-05-02

74

C-Npys (S-3-nitro-2-pyridinesulfenyl) and peptide derivatives can inhibit a serine-thiol proteinase activity from Paracoccidioides brasiliensis.  

PubMed

The inhibitory capacity of C-Npys (S-[3-nitro-2-pyridinesulfenyl]) derivatives over thiol-containing serine proteases has never been tested. In the present work we used an extracellular serine-thiol proteinase activity from the fungal pathogen Paracoccidioides brasiliensis (PbST) to describe a potent inhibitory capacity of Bzl-C(Npys)KRLTL-NH(2) and Bzl-MKRLTLC(Npys)-NH(2). The assays were performed with PbST enriched upon affinity chromatography in a p-aminobenzamidine (pABA)-Sepharose column. Although PbST can cleave the fluorescence resonance energy transfer peptide Abz-MKRLTL-EDDnp between L-T, the C(Npys) derivatives were not substrates nor were they toxic in a cell detachment assay, allowing therapeutic use. The best inhibitor was Bzl-C(Npys)KRLTL-NH(2) (K(i)=16nM), suggesting that the peptide sequence promoted a favorable interaction, especially when C(Npys) was placed at a further position from the L-T bond, at the N-terminus. Inhibition was completely reverted with dithioerythritol, indicating that it was due to the reactivity of the C(Npys) moiety with a free SH- group. PMID:17328865

Matsuo, Alisson L; Carmona, Adriana K; Silva, Luiz S; Cunha, Carlos E L; Nakayasu, Ernesto S; Almeida, Igor C; Juliano, Maria A; Puccia, Rosana

2007-02-23

75

Influence of 17?-Estradiol on Gene Expression of Paracoccidioides during Mycelia-to-Yeast Transition  

PubMed Central

Background Paracoccidioides is the causative agent of paracoccidioidomycosis, a systemic mycosis endemic to Latin America. Infection is initiated by inhalation of conidia (C) or mycelial (M) fragments, which subsequently differentiate into yeast (Y). Epidemiological studies show a striking predominance of paracoccidioidomycosis in adult men compared to premenopausal women. In vitro and in vivo studies suggest that the female hormone (17?-estradiol, E2) regulates or inhibits M-or-C-to-Y transition. In this study we have profiled transcript expression to understand the molecular mechanism of how E2 inhibits M-to-Y transition. Methodology We assessed temporal gene expression in strain Pb01 in the presence or absence of E2 at various time points through 9 days of the M-to-Y transition using an 11,000 element random-shear genomic DNA microarray and verified the results using quantitative real time-PCR. E2-regulated clones were sequenced to identify genes and biological function. Principal Findings E2-treatment affected gene expression of 550 array elements, with 331 showing up-regulation and 219 showing down-regulation at one or more time points (p?0.001). Genes with low expression after 4 or 12 h exposure to E2 belonged to pathways involved in heat shock response (hsp90 and hsp70), energy metabolism, and several retrotransposable elements. Y-related genes, ?-1,3-glucan synthase, mannosyltransferase and Y20, demonstrated low or delayed expression in E2-treated cultures. Genes potentially involved in signaling, such as palmitoyltransferase (erf2), small GTPase RhoA, phosphatidylinositol-4-kinase, and protein kinase (serine/threonine) showed low expression in the presence of E2, whereas a gene encoding for an arrestin domain-containing protein showed high expression. Genes related to ubiquitin-mediated protein degradation, and oxidative stress response genes were up-regulated by E2. Conclusion This study characterizes the effect of E2 at the molecular level on the inhibition of the M-to-Y transition and is indicative that the inhibitory actions of E2 may be working through signaling genes that regulate dimorphism.

Shankar, Jata; Wu, Thomas D.; Clemons, Karl V.; Monteiro, Jomar P.; Mirels, Laurence F.; Stevens, David A.

2011-01-01

76

Anti-CD25 Treatment Depletes Treg Cells and Decreases Disease Severity in Susceptible and Resistant Mice Infected with Paracoccidioides brasiliensis  

PubMed Central

Regulatory T (Treg) cells are fundamental in the control of immunity and excessive tissue pathology. In paracoccidioidomycosis, an endemic mycosis of Latin America, the immunoregulatory mechanisms that control the progressive and regressive forms of this infection are poorly known. Due to its modulatory activity on Treg cells, we investigated the effects of anti-CD25 treatment over the course of pulmonary infection in resistant (A/J) and susceptible (B10.A) mice infected with Paracoccidioides brasiliensis. We verified that the resistant A/J mice developed higher numbers and more potent Treg cells than susceptible B10.A mice. Compared to B10.A cells, the CD4+CD25+Foxp3+ Treg cells of A/J mice expressed higher levels of CD25, CTLA4, GITR, Foxp3, LAP and intracellular IL-10 and TGF-?. In both resistant and susceptible mice, anti-CD25 treatment decreased the CD4+CD25+Foxp3+ Treg cell number, impaired indoleamine 2,3-dioxygenase expression and resulted in decreased fungal loads in the lungs, liver and spleen. In A/J mice, anti-CD25 treatment led to an early increase in T cell immunity, demonstrated by the augmented influx of activated CD4+ and CD8+ T cells, macrophages and dendritic cells to the lungs. At a later phase, the mild infection was associated with decreased inflammatory reactions and increased Th1/Th2/Th17 cytokine production. In B10.A mice, anti-CD25 treatment did not alter the inflammatory reactions but increased the fungicidal mechanisms and late secretion of Th1/Th2/Th17 cytokines. Importantly, in both mouse strains, the early depletion of CD25+ cells resulted in less severe tissue pathology and abolished the enhanced mortality observed in susceptible mice. In conclusion, this study is the first to demonstrate that anti-CD25 treatment is beneficial to the progressive and regressive forms of paracoccidioidomycosis, potentially due to the anti-CD25-mediated reduction of Treg cells, as these cells have suppressive effects on the early T cell response in resistant mice and the clearance mechanisms of fungal cells in susceptible mice.

Felonato, Maira; Pina, Adriana; de Araujo, Eliseu Frank; Loures, Flavio V.; Bazan, Silvia B.; Feriotti, Claudia; Calich, Vera L. G.

2012-01-01

77

Microplate alamarBlue Assay for Paracoccidioides Susceptibility Testing  

PubMed Central

CLSI method M27-A3 is not available for use with dimorphic fungi, such as those of the Paracoccidioides genus. In this study, we developed a microdilution method and added the alamarBlue reagent to test the responses of Paracoccidioides brasiliensis and Paracoccidioides lutzii against amphotericin B and itraconazole antifungals. The test proved to be sensitive, practical, and inexpensive and can be used to monitor the activity of low-growth microorganisms and their response to various drugs.

de Paula e Silva, A. C. A.; Oliveira, H. C.; Silva, J. F.; Sangalli-Leite, F.; Scorzoni, L.; Fusco-Almeida, A. M.

2013-01-01

78

Microplate alamarBlue assay for Paracoccidioides susceptibility testing.  

PubMed

CLSI method M27-A3 is not available for use with dimorphic fungi, such as those of the Paracoccidioides genus. In this study, we developed a microdilution method and added the alamarBlue reagent to test the responses of Paracoccidioides brasiliensis and Paracoccidioides lutzii against amphotericin B and itraconazole antifungals. The test proved to be sensitive, practical, and inexpensive and can be used to monitor the activity of low-growth microorganisms and their response to various drugs. PMID:23345296

de Paula e Silva, A C A; Oliveira, H C; Silva, J F; Sangalli-Leite, F; Scorzoni, L; Fusco-Almeida, A M; Mendes-Giannini, M J S

2013-01-23

79

Characterization of Cell Wall Lipids from the Pathogenic Phase of Paracoccidioides brasiliensis Cultivated in the Presence or Absence of Human Plasma  

PubMed Central

Background The fungal cell wall is a complex and dynamic outer structure. In pathogenic fungi its components interact with the host, determining the infection fate. The present work aimed to characterize cell wall lipids from P. brasiliensis grown in the presence and absence of human plasma. We compared the results from isolates Pb3 and Pb18, which represent different phylogenetic species that evoke distinct patterns of experimental paracoccidioidomycosis. Methodology/Principal Findings We comparatively characterized cell wall phospholipids, fatty acids, sterols, and neutral glycolipids by using both electrospray ionization- and gas chromatography-mass spectrometry analyses of lipids extracted with organic solvents followed by fractionation in silica-gel-60. We detected 49 phospholipid species in Pb3 and 38 in Pb18, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, and phosphatidic acid. In both Pb3 and Pb18, PC and PE had the most numerous species. Among the fatty acids, C18?1 and C18?2 were the most abundant species in both isolates, although C18?2 was more abundant in Pb18. There was a different effect of plasma supplementation on fatty acids depending on the fungal isolate. The prevalent glycolipid species was Hex-C18?0-OH/d19?2-Cer, although other four minor species were also detected. The most abundant sterol in all samples was brassicasterol. Distinct profiles of cell wall and total yeast sterols suggested that the preparations were enriched for cell wall components. The presence of plasma in the culture medium specially increased cell wall brassicasterol abundance and also other lipids. Conclusions/Significance We here report an original comparative lipidomic analysis of P. brasiliensis cell wall. Our results open doors to understanding the role of cell wall lipids in fungal biology, and interaction with anti-fungal drugs and the host.

Gazos-Lopes, Felipe; Vallejo, Milene C.; Matsuo, Alisson L.; Almeida, Igor C.; Puccia, Rosana

2013-01-01

80

NUTRITIONAL STUDIES ON THE YEAST PHASE OF BLASTOMYCES DERMATITIDIS AND B. BRASILIENSIS1  

PubMed Central

Gilardi, Gerald L. (University of Maryland, College Park) and Norman C. Laffer. Nutritional studies on the yeast phase of Blastomyces dermatitidis and B. brasiliensis. J. Bacteriol. 83:219–227. 1962.—Nutritional characteristics of the yeast phase of 22 cultures of the genus Blastomyces (9 of B. brasiliensis and 13 of B. dermatitidis) were examined to see if differences in nutritional behavior occurred which could serve as an aid in a more definitive classification. The studies included vitamin and amino acid requirements, carbon and nitrogen assimilation tests, and comparison of growth obtained with quiescent, agar slant, and shake cultures. Both species synthesized their own vitamins, utilized the same 21 carbon and 25 nitrogen substrates as the sole source of the respective element, and produced their most luxuriant growth in shake cultures in the presence of either ammonium salts or organic nitrogen. Sulfur-containing compounds, reducing agents, and Tween 80 were observed to retard or inhibit growth. Inhibition of yeast phase maintenance, and the conversion to the mold phase at 35 C, occurred in the presence of tyrosine. No difference was detected between the two species; variation occurred only at the culture level. On the basis of the similarity of nutritional characteristics, there appears to be no justification to separate the two species into separate genera, as proposed by some authors.

Gilardi, Gerald L.; Laffer, Norman C.

1962-01-01

81

In Silico Prediction of Peptides Binding to Multiple HLA-DR Molecules Accurately Identifies Immunodominant Epitopes from gp43 of Paracoccidioides brasiliensis Frequently Recognized in Primary Peripheral Blood Mononuclear Cell Responses from Sensitized Individuals  

PubMed Central

One of the major drawbacks limiting the use of synthetic peptide vaccines in genetically distinct populations is the fact that different epitopes are recognized by T cells from individuals displaying distinct major histocompatibility complex molecules. Immunization of mice with peptide (181-195) from the immunodominant 43 kDa glycoprotein of Paracoccidioides brasiliensis (gp43), the causative agent of Paracoccidioidomycosis (PCM), conferred protection against infectious challenge by the fungus. To identify immunodominant and potentially protective human T-cell epitopes in gp43, we used the TEPITOPE algorithm to select peptide sequences that would most likely bind multiple HLA-DR molecules and tested their recognition by T cells from sensitized individuals. The 5 most promiscuous peptides were selected from the gp43 sequence and the actual promiscuity of HLA binding was assessed by direct binding assays to 9 prevalent HLA-DR molecules. Synthetic peptides were tested in proliferation assays with peripheral blood mononuclear cells (PBMC) from PCM patients after chemotherapy and healthy controls. PBMC from 14 of 19 patients recognized at least one of the promiscuous peptides, whereas none of the healthy controls recognized the gp43 promiscuous peptides. Peptide gp43(180-194) was recognized by 53% of patients, whereas the other promiscuous gp43 peptides were recognized by 32% to 47% of patients. The frequency of peptide binding and peptide recognition correlated with the promiscuity of HLA-DR binding, as determined by TEPITOPE analysis. In silico prediction of promiscuous epitopes led to the identification of naturally immunodominant epitopes recognized by PBMC from a significant proportion of a genetically heterogeneous patient population exposed to P. brasiliensis. The combination of several such epitopes may increase the frequency of positive responses and allow the immunization of genetically distinct populations.

Iwai, Leo Kei; Yoshida, Marcia; Sidney, John; Shikanai-Yasuda, Maria Aparecida; Goldberg, Anna Carla; Juliano, Maria Aparecida; Hammer, Jurgen; Juliano, Luiz; Sette, Alessandro; Kalil, Jorge; Travassos, Luiz Rodolpho; Cunha-Neto, Edecio

2003-01-01

82

Genus Paracoccidioides: Species Recognition and Biogeographic Aspects  

PubMed Central

Background Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3), and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. Methodology/Principal Findings Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3) were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE) analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11–32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. Conclusions/Significance The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides.

Theodoro, Raquel Cordeiro; Teixeira, Marcus de Melo; Felipe, Maria Sueli Soares; Paduan, Karina dos Santos; Ribolla, Paulo Martins; San-Blas, Gioconda; Bagagli, Eduardo

2012-01-01

83

Identification and characterization of Tc1\\/mariner-like DNA transposons in genomes of the pathogenic fungi of the Paracoccidioides species complex  

Microsoft Academic Search

BACKGROUND: Paracoccidioides brasiliensis (Eukaryota, Fungi, Ascomycota) is a thermodimorphic fungus, the etiological agent of paracoccidioidomycosis, the most important systemic mycoses in Latin America. Three isolates corresponding to distinct phylogenetic lineages of the Paracoccidioides species complex had their genomes sequenced. In this study the identification and characterization of class II transposable elements in the genomes of these fungi was carried out.

Marjorie M Marini; Tamiris Zanforlin; Patrícia C Santos; Roberto RM Barros; Rosana Puccia; Maria SS Felipe; Marcelo Brigido; Célia MA Soares; Jerônimo C Ruiz; José F Silveira; Patrícia S Cisalpino

2010-01-01

84

P. brasiliensis Virulence Is Affected by SconC, the Negative Regulator of Inorganic Sulfur Assimilation.  

PubMed

Conidia/mycelium-to-yeast transition of Paracoccidioidesbrasiliensis is a critical step for the establishment of paracoccidioidomycosis, a systemic mycosis endemic in Latin America. Thus, knowledge of the factors that mediate this transition is of major importance for the design of intervention strategies. So far, the only known pre-requisites for the accomplishment of the morphological transition are the temperature shift to 37°C and the availability of organic sulfur compounds. In this study, we investigated the auxotrophic nature to organic sulfur of the yeast phase of Paracoccidioides, with special attention to P. brasiliensis species. For this, we addressed the role of SconCp, the negative regulator of the inorganic sulfur assimilation pathway, in the dimorphism and virulence of this pathogen. We show that down-regulation of SCONC allows initial steps of mycelium-to-yeast transition in the absence of organic sulfur compounds, contrarily to the wild-type fungus that cannot undergo mycelium-to-yeast transition under such conditions. However, SCONC down-regulated transformants were unable to sustain yeast growth using inorganic sulfur compounds only. Moreover, pulses with inorganic sulfur in SCONC down-regulated transformants triggered an increase of the inorganic sulfur metabolism, which culminated in a drastic reduction of the ATP and NADPH cellular levels and in higher oxidative stress. Importantly, the down-regulation of SCONC resulted in a decreased virulence of P. brasiliensis, as validated in an in vivo model of infection. Overall, our findings shed light on the inability of P. brasiliensis yeast to rely on inorganic sulfur compounds, correlating its metabolism with cellular energy and redox imbalances. Furthermore, the data herein presented reveal SconCp as a novel virulence determinant of P. brasiliensis. PMID:24066151

Menino, João Filipe; Saraiva, Margarida; Gomes-Rezende, Jéssica; Sturme, Mark; Pedrosa, Jorge; Castro, António Gil; Ludovico, Paula; Goldman, Gustavo H; Rodrigues, Fernando

2013-09-16

85

P. brasiliensis Virulence Is Affected by SconC, the Negative Regulator of Inorganic Sulfur Assimilation  

PubMed Central

Conidia/mycelium-to-yeast transition of Paracoccidioidesbrasiliensis is a critical step for the establishment of paracoccidioidomycosis, a systemic mycosis endemic in Latin America. Thus, knowledge of the factors that mediate this transition is of major importance for the design of intervention strategies. So far, the only known pre-requisites for the accomplishment of the morphological transition are the temperature shift to 37°C and the availability of organic sulfur compounds. In this study, we investigated the auxotrophic nature to organic sulfur of the yeast phase of Paracoccidioides, with special attention to P. brasiliensis species. For this, we addressed the role of SconCp, the negative regulator of the inorganic sulfur assimilation pathway, in the dimorphism and virulence of this pathogen. We show that down-regulation of SCONC allows initial steps of mycelium-to-yeast transition in the absence of organic sulfur compounds, contrarily to the wild-type fungus that cannot undergo mycelium-to-yeast transition under such conditions. However, SCONC down-regulated transformants were unable to sustain yeast growth using inorganic sulfur compounds only. Moreover, pulses with inorganic sulfur in SCONC down-regulated transformants triggered an increase of the inorganic sulfur metabolism, which culminated in a drastic reduction of the ATP and NADPH cellular levels and in higher oxidative stress. Importantly, the down-regulation of SCONC resulted in a decreased virulence of P. brasiliensis, as validated in an in vivo model of infection. Overall, our findings shed light on the inability of P. brasiliensis yeast to rely on inorganic sulfur compounds, correlating its metabolism with cellular energy and redox imbalances. Furthermore, the data herein presented reveal SconCp as a novel virulence determinant of P. brasiliensis.

Menino, Joao Filipe; Saraiva, Margarida; Gomes-Rezende, Jessica; Sturme, Mark; Pedrosa, Jorge; Castro, Antonio Gil; Ludovico, Paula; Goldman, Gustavo H.; Rodrigues, Fernando

2013-01-01

86

Occurrence of Paracoccidioides lutzii in the Amazon Region: Description of Two Cases  

PubMed Central

Paracoccidioidomycosis (PCM), the most important human systemic mycosis in Latin America, is known to be caused by at least four different phylogenetic lineages within the Paracoccidioides brasiliensis complex, including S1, PS2, PS3, and Pb01-like group. Herein, we describe two cases of PCM in patients native from the Amazon region. The disease was originally thought to have been caused by P. brasiliensis. Despite the severity of the cases, sera from the patients were negative in immunodiffusion tests using the standard exoantigen from P. brasiliensis B-339. However, a positive response was recorded with an autologous preparation of Paracoccidioides lutzii exoantigen. A phylogenetic approach based on the gp43 and ARF loci revealed high similarity between our clinical isolates and the Pb01-like group. The occurrence of PCM caused by P. lutzii in the Brazilian Amazon (Pará State) was thus proven. The incidence of PCM caused by P. lutzii may be underestimated in northern Brazil.

Marques-da-Silva, Silvia Helena; Messias Rodrigues, Anderson; de Hoog, G. Sybren; Silveira-Gomes, Fabiola; Pires de Camargo, Zoilo

2012-01-01

87

Intermolecular interactions of the malate synthase of Paracoccidioides spp  

PubMed Central

Background The fungus Paracoccidioides spp is the agent of paracoccidioidomycosis (PCM), a pulmonary mycosis acquired by the inhalation of fungal propagules. Paracoccidioides malate synthase (PbMLS) is important in the infectious process of Paracoccidioides spp because the transcript is up-regulated during the transition from mycelium to yeast and in yeast cells during phagocytosis by murine macrophages. In addition, PbMLS acts as an adhesin in Paracoccidioides spp. The evidence for the multifunctionality of PbMLS indicates that it could interact with other proteins from the fungus and host. The objective of this study was to identify and analyze proteins that possibly bind to PbMLS (PbMLS-interacting proteins) because protein interactions are intrinsic to cell processes, and it might be possible to infer the function of a protein through the identification of its ligands. Results The search for interactions was performed using an in vivo assay with a two-hybrid library constructed in S. cerevisiae; the transcripts were sequenced and identified. In addition, an in vitro assay using pull-down GST methodology with different protein extracts (yeast, mycelium, yeast-secreted proteins and macrophage) was performed, and the resulting interactions were identified by mass spectrometry (MS). Some of the protein interactions were confirmed by Far-Western blotting using specific antibodies, and the interaction of PbMLS with macrophages was validated by indirect immunofluorescence and confocal microscopy. In silico analysis using molecular modeling, dynamics and docking identified the amino acids that were involved in the interactions between PbMLS and PbMLS-interacting proteins. Finally, the interactions were visualized graphically using Osprey software. Conclusion These observations indicate that PbMLS interacts with proteins that are in different functional categories, such as cellular transport, protein biosynthesis, modification and degradation of proteins and signal transduction. These data suggest that PbMLS could play different roles in the fungal cell.

2013-01-01

88

Spathaspora brasiliensis sp. nov., Spathaspora suhii sp. nov., Spathaspora roraimanensis sp. nov. and Spathaspora xylofermentans sp. nov., four novel (D)-xylose-fermenting yeast species from Brazilian Amazonian forest.  

PubMed

Four new D-xylose fermenting yeast species of the clade Spathaspora were recovered from rotting-wood samples in a region of Amazonian forest, Northern Brazil. Three species produced unconjugated asci with a single elongated ascospore with curved ends. These species are described as Spathaspora brasiliensis, Spathaspora suhii and Spathaspora roraimanensis. Two isolates of an asexually reproducing species belonging to the Spathaspora clade were also obtained and they are described as Spathaspora xylofermentans. All these species are able to ferment D-xylose during aerobic batch growth in rich YP (1 % yeast extract, 2 % peptone and 2 % D-xylose) medium, albeit with differing efficiencies. The type strains are Spathaspora brasiliensis sp. nov UFMG-HMD19.3 (=CBMAI 1425=CBS 12679), Spathaspora suhii sp. nov. UFMG-XMD16.2 (=CBMAI 1426=CBS 12680), Spathaspora roraimanensis sp. nov. UFMG-XMD23.2 (CBMAI 1427=CBS 12681) and Spathaspora xylofermentans sp. nov. UFMG-HMD23.3 (=CBMAI 1428=CBS 12682). PMID:23053696

Cadete, Raquel M; Melo, Monaliza A; Zilli, Jerri E; Vital, Marcos J S; Mouro, Adriane; Prompt, Alice H; Gomes, Fátima C O; Stambuk, Boris U; Lachance, Marc-André; Rosa, Carlos A

2012-10-05

89

Results of long-standing mycological analyses of biological materials originating from selected organ ontocenoses--yeast and yeast-like fungi.  

PubMed

This paper reviews the results of an extensive monitoring study, spanning 20-years of observation from three medical centres in Olsztyn on the dynamics and species diversity of fungi most frequently colonizing the respiratory and digestive systems of humans. The experimental materials were swabs and specimens from the gastrointestinal tract, swabs from the oral cavity and pharynx, as well as sputum and bronchial fluid from the respiratory system. The biological material was subjected to routine mycological diagnostics, taxonomic determination and identification. In total, 41 species of yeast and yeast-like fungi were isolated, including 34 from the respiratory and 25 from the digestive system. In the last decade, a significant increase has been noticed in the counts of fungi, especially the gastrointestinal tract, reported from people. As many as 18 species were isolated from both systems--they were predominated by fungi of the genus Candida and their perfect forms. Worthy of notice are also frequent isolations of yeast (Saccharomyces spp.) and detection of an endemic species, Paracoccidioides brasiliensis, in the respiratory system, and of the sexual stages of Rhodosporidium diobovatum and Rhodosporidium kratochvilovae from the gastrointestinal tract. PMID:21682094

Dynowska, Maria; Góralska, Katarzyna; Troska, Piotr; Bara?ska, Grazyyna; Biedunkiewicz, Anna; Ejdys, Elzbieta; Sucharzewska, Ewa

2011-01-01

90

Melanin as a virulence factor of Paracoccidioides brasiliensis and other dimorphic pathogenic fungi: a minireview  

Microsoft Academic Search

Melanin pigments are substances produced by a broad variety of pathogenic microorganisms, including bacteria, fungi, and helminths.\\u000a Microbes predominantly produce melanin pigment via tyrosinases, laccases, catecholases, and the polyketide synthase pathway.\\u000a In fungi, melanin is deposited in the cell wall and cytoplasm, and melanin particles (“ghosts”) can be isolated from these\\u000a fungi that have the same size and shape of

Carlos P. Taborda; Marcelo B. da Silva; Joshua D. Nosanchuk; Luiz R. Travassos

2008-01-01

91

Factors associated with Paracoccidiodes brasiliensis infection among permanent residents of three endemic areas in Colombia.  

PubMed Central

The natural habitat of Paracoccidioides brasiliensis, the aetiologic agent of paracoccidioidomycosis, has not been determined. Consequently, the events leading to the acquisition of infection remain controversial. To identify factors associated with infection in endemic areas we conducted a survey in three rural communities in Colombia where we had previously diagnosed paracoccidioidomycosis in children. Permanent residents were surveyed taking into consideration environmental and occupational variables. Skin tests were used to classify subjects as infected or non-infected. Variables found associated with infection were: (i) community A: previous residence around Porce river and agriculture in vegetable gardens; (ii) community C: frequent use of specific water sources; (iii) community V: housekeeping activities, and (iv) total group: age > 25 years and contact with bats. Residents in communities with higher prevalence of infection were older, had more complex residence history, and referred more contact with armadillos than residents of communities with lower infection.

Cadavid, D.; Restrepo, A.

1993-01-01

92

Galleria mellonella as a model host to study Paracoccidioides lutzii and Histoplasma capsulatum.  

PubMed

Non-mammalian models have been used to investigate fungal virulence. In this work we have explored the use of Galleria mellonella as an infection model for the pathogenic dimorphic fungi Histoplasma capsulatum and Paracoccidioides lutzii. In mammalian models these fungi cause similar infections, and disease outcomes are influenced by the quantity of the infective inocula. We describe a similar aspect in a G. mellonella model and characterize the pathogenesis features in this system. Infection with P. lutzii or H. capsulatum, in all inoculum used, killed larvae at 25 and 37°C. However, there was a lack of correlation between the number of yeast cells used for infection and the time to larvae death, which may indicate that the fungi induce protective responses in a dynamic manner as the lowest concentrations of fungi induced the most rapid death. For both fungi, the degree of larvae melanization was directly proportional to the inocula size, and this effect was visibly more apparent at 37°C. Histological evaluation of the larvae showed a correlation between the inoculum and granuloma-like formation. Our results suggest that G. mellonella is a potentially useful model to study virulence of dimorphic fungi. PMID:23302787

Thomaz, Luciana; García-Rodas, Rocío; Guimarães, Allan J; Taborda, Carlos P; Zaragoza, Oscar; Nosanchuk, Joshua D

2013-01-09

93

Cell-free antigens of Sporothrix brasiliensis: antigenic diversity and application in an immunoblot assay.  

PubMed

Sporotrichosis is a subcutaneous mycosis diagnosed by isolation of the fungus in culture. Serological tests for help in diagnosis in general do not use purified or recombinant antigens, because there is a paucity of described immunoreactive proteins, especially for the new described Sporothrix species, such as Sporothrix brasiliensis. This study aims to characterise antigens from S. brasiliensis and verify their application in serodiagnosis of sporotrichosis. An immunoblot assay allied with computer-based analysis was used to identify putative antigenic molecules in a cell-free extracts of both morphological phases of this fungus, and to delineate antigenic polymorphism among seven S. brasiliensis isolates and one S. schenckii Brazilian strain. The mycelial and yeast phase of the fungus originated 14 and 23 reactive bands, respectively, which were variable in intensity. An 85 kDa antigen, verified in the yeast phase of the fungus, was observed in all strains used and the immunodominant protein was identified. This protein, however, cross-react with serum samples from patients infected with other pathogens. The results show that the S. brasiliensis cell-free antigen extract is a single and inexpensive source of antigens, and can be applied on the sporotrichosis serodiagnosis. PMID:22369676

Almeida-Paes, Rodrigo; Bailão, Alexandre Melo; Pizzini, Cláudia Vera; Reis, Rosani Santos; Soares, Célia Maria de Almeida; Peralta, José Mauro; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

2012-02-28

94

Pulmonary Paracoccidioidomycosis Misdiagnosed as PneumocystisPneumonia in an Immunocompromised Host  

Microsoft Academic Search

Yeast cells of Paracoccidioides brasiliensis can resemble the cysts of Pneumocystis carinii in smears stained with Grocott's modification of the Gomori methanamine silver stain. Furthermore, P. brasiliensis can cross- react in material stained with a widely used P. carinii immunofluorescent stain which uses monoclonal antibodies. The need to differentiateP. brasiliensisandP. cariniiwill become more important as the increasing incidence of immunosuppression

RODGER P. SILLETTI; VALERY GLEZEROV; ANDIRA S. SCHWARTZ

1996-01-01

95

Nocardia brasiliensis: mycetoma induction and growth cycle.  

PubMed Central

The capacity of Nocardia brasiliensis to induce mycetoma in BALB/c mice in the absence of adjuvants was studied. Whether the virulence of N. brasiliensis varied in the different phases of its growth cycle was also determined. The results showed that N. brasiliensis suspended in 0.15 M NaCl and injected into the footpads of mice were able to induce mycetoma after only 14 days of infection, as evidenced by histological studies. Data are also presented indicating that the virulence of N. brasiliensis did not vary during the different phases of its growth curve. The differences in virulence reported between N. brasiliensis and other nocardiae are discussed and explained in terms of several variables in the experimental designs used: among these variables are mouse genotype, route of inoculation, and model for determining virulence. Images

Conde, C; Melendro, E I; Fresan, M; Ortiz-Ortiz, L

1982-01-01

96

Lymphocutaneous nocardiosis due to Nocardia brasiliensis.  

PubMed

Nocardia species are Gram-positive bacteria responsible for systemic or cutaneous infections in humans. Nocardia brasiliensis is the most common infective agent in the cutaneous form of nocardiosis. We describe a case of a previously healthy man, who presented with lymphocutaneous Nocardia brasiliensis infection, and was successfully treated with trimethoprim-sulfamethoxazole. The identification of the isolate was confirmed by nucleotide sequence analysis of the 16S rRNA gene. PMID:12967747

Maraki, Sofia; Scoulica, Efstathia; Alpantaki, Kalliopi; Dialynas, Michael; Tselentis, Yannis

2003-09-01

97

Characterization of HbWRKY1, a WRKY transcription factor from Hevea brasiliensis that negatively regulates HbSRPP.  

PubMed

Small rubber particle protein (SRPP) is a major component of Hevea brasiliensis (H. brasiliensis) latex, which is involved in natural rubber (NR) biosynthesis. However, little information is available on the regulation of SRPP gene (HbSRPP) expression. To study the transcriptional regulation of HbSRPP, the yeast one-hybrid experiment was performed to screen the latex cDNA library using the HbSRPP promoter as bait. One cDNA that encodes the WRKY transcription factor, designated as HbWRKY1, was isolated from H. brasiliensis. HbWRKY1 contains a 1437 bp open reading frame that encodes 478 amino acids. The deduced HbWRKY1 protein was predicted to possess two conserved WRKY domains and a C2H2 zinc-finger motif. HbWRKY1 was expressed at different levels, with the highest transcription in the flower, followed by the bark, latex, and leaf. Furthermore, the co-expression of pHbSRP::GUS with CaMV35S::HbWRKY1 significantly decreased the GUS activity in transgenic tobacco, indicating that HbWRKY1 significantly suppressed the HbSRPP promoter. These results suggested that HbWRKY1 maybe a negative transcription regulator of HbSRPP involved in NR biosynthesis in H. brasiliensis. PMID:23988297

Wang, Ying; Guo, Dong; Li, Hui-Liang; Peng, Shi-Qing

2013-08-07

98

Summary of Basis for ORTHO® T. cruzi ELISA Test System ...  

Center for Biologics Evaluation and Research (CBER)

Text Version... Additional testing for Leishmania, Malaria, Syphilis, and Paracoccidioides brasiliensis (P. brasiliensis) should be considered. ... More results from www.fda.gov/downloads/biologicsbloodvaccines/bloodbloodproducts

99

Production and characterization of the exopolysaccharides produced by Agaricus brasiliensis in submerged fermentation.  

PubMed

The aim of the work was to study the production of the exopolysaccharides by Agaricus brasiliensis and the isolation of exopolysaccharides (EPSs) with biological effects. A brasiliensis LPB03 was cultured in submerged fermentation in a medium containing glucose, yeast extract, hydrolyzed soybean protein, and salts (pH 6.1) at 29 degrees C and 120 rpm for 144 h. The maximum biomass and EPS yield was 7.80 +/- 0.01 and 1,430.70 +/- 26.75 mg/L, respectively. To isolate the produced EPSs, two methods were compared: (1) with alcohol precipitation and (2) treatment with tricloroacetic acid (TCA), followed by alcohol precipitation. The use of TCA facilitated the purification of the EPS, reducing the amount of the contaminant soy proteins. For monosaccharide identification, the EPSs were hydrolyzed, derivatized to alditol acetates, and analyzed by gas chromatography (GC) and GC-mass spectrometry, which showed the presence (in molar percentage) of mannose (58.7), galactose (21.4), and glucose (13.1) as major sugars, with lower amounts of rhamnose (3.9) and xylose (2.8). Scanning electron microscopy was used to observe the morphological structure of the EPS. The experiments in vivo including EPS in the mice diet during 8 weeks indicated the hipocholesteremic and hypoglycemic effects. PMID:18516506

Lima, L F O; Habu, S; Gern, J C; Nascimento, B M; Parada, Jose-Luis; Noseda, M D; Gonçalves, A G; Nisha, V R; Pandey, Ashok; Soccol, Vanete Thomaz; Soccol, Carlos R

2008-05-31

100

Brasilinolide A, new immunosuppressive macrolide from actinomycete Nocardia brasiliensis  

Microsoft Academic Search

A new 32-membered macrolide, brasilinolide A (1), with potent immunosuppressive and antifungal activity was isolated from the cultured broth of the actinomycete Nocardia brasiliensis IFM 0406 and the structure elucidated on the basis of spectroscopic data and chemical means.

Shigemori Hideyuki; Tanaka Yasushi; Yazawa Katsukiyo; Mikami Yuzuru; Kobayashi Jun'ichi

1996-01-01

101

Reproductive biology in the primitive relic Angiosperm Drimys brasiliensis ( Winteraceae )  

Microsoft Academic Search

From field observations onDrimys brasiliensis, principally in the Botucatu region of São Paulo State, Brazil, new data on the reproductive biology, the rhythm of growth, and the development of lateral cymose inflorescences, flowers and fruits are presented. Pollination accelerates the rate of flower-development for about 4–6 days. Pollination experiments show thatD. brasiliensis is not self-sterile; because of mechanical devices the

Gerhard Gottsberger; Ilse Silberbauer-Gottsberger; Friedrich Ehrendorfer

1980-01-01

102

Antioxidant Activity of Agaricus brasiliensis Basidiocarps on Different Maturation Phases  

PubMed Central

Different maturation phases of basidiocarp could affect the bioactivity and concentration of some active substances. A. brasiliensis Wasser et al. (A. blazei Murrill) has shown antitumor activity that could be related to the antioxidant activity. However there is no information of the best basidiocarp maturation phase for extracting antioxidant substances in order to determine the moment of harvesting in mushroom cultivation. The objective of this work was to evaluate the antioxidant activity of A. brasiliensis strains on different basidiocarp maturation phases. The best condition for extraction of A. brasiliensis antioxidants is with methanol as solvent at 60 °C for 60 min. Strains with closed basidiocarp have higher antioxidant activity than with opened basidiocarp. Antioxidant activity varies in each strain. It was concluded that A. brasiliensis is a natural source of antioxidant compounds. Also there is higher antioxidant activity in closed than opened caps and consequently higher functional activity. It reinforces the synergic action among different A. brasiliensis compounds as a functional food and the importance of further investigation for isolation and characterization of antioxidant substances of A. brasiliensis. It also determines the best harvest period in order to obtain the highest antioxidant activity from basidiocarp.

Mourao, Francielly; Harue Umeo, Suzana; Seiko Takemura, Orlando; Andrea Linde, Giani; Barros Colauto, Nelson

2011-01-01

103

Dry yeast  

NSDL National Science Digital Library

Yeast is a type of eukaryotic organism that can live in a dormant state. It can be activated from its dormant state by water and sugar. The yeast uses the sugar to grow and produces carbon dioxide gas as a byproduct.

Ranveig Thattai (None;)

2005-09-27

104

Vaginal Yeast Infections  

MedlinePLUS

... HIV/AIDS Sexually transmitted infections fact sheet Vaginal yeast infections fact sheet What is a vaginal yeast ... on vaginal yeast infections What is a vaginal yeast infection? A vaginal yeast infection is irritation of ...

105

Susceptibility of species within the Sporothrix schenckii complex to a panel of killer yeasts.  

PubMed

The Sporothrix schenckii complex is the etiologic agent of sporotrichosis, a subacute or chronic mycosis which can affect humans and animals. Killer yeasts have been used in the medical field for development of novel antimycotics and biotyping of pathogenic fungi. The action of 18 killer yeasts on the growth of 88 characterized S. schenckii, Sporothrix globosa, Sporothrix brasiliensis, and Sporothrix mexicana clinical and environmental isolates was evaluated. Killer studies were performed on Petri dishes containing cheese black starch agar. The yeasts Candida catenulata (QU26, QU31, QU127, LV102); Trichosporon faecale (QU100); Trichosporon japonicum (QU139); Kluyveromyces lactis (QU30, QU99, QU73); Kazachstania unispora (QU49), Trichosporon insectorum (QU89), and Kluyveromyces marxianus (QU103) showed activity against all strains of the S. schenckii complex tested. Observation by optical microscopy of S. brasiliensis 61 within the inhibition haloes around the colonies of the killer yeasts QU100, QU139, and LV102 showed that there was no conidiation, but there was hyphal proliferation. The toxins were fungistatic against S. brasiliensis 61. There was no difference in susceptibility to the toxins among the S. schenckii species complex. Further investigations are necessary to clearly establish the mechanism of action of the toxins. PMID:23686831

Stopiglia, Cheila Denise Ottonelli; Heidrich, Daiane; Sorrentino, Julia Medeiros; Vieira, Fabiane Jamono; Landell, Melissa Fontes; Valente, Patrícia; Scroferneker, Maria Lúcia

2013-05-17

106

Antineoplasic activity of Agaricus brasiliensis basidiocarps on different maturation phases  

PubMed Central

The fungus Agaricus brasiliensis is a Basidiomycete studied because of its immunomodulation and/or antitumor substances. The objective of this study was to verify the Agaricus brasiliensis antineoplasic activity in vivo on different basidiocarp maturation phases on Sarcoma 180 cells implanted in mice. Sarcoma cells were implanted in mice and after seven days mice were divided in three groups. The first group was treated with saline solution, the second group was treated with closed basidiocarp extract solution and the third group was treated with opened basidiocarp extract solution. After 30 days of being daily orally treated with these three solutions all animals suffered euthanasia, and the splenic index, tumor mass and volume were determined. No significant differences of the tumor growth inhibition in function of the different basidiocarp maturation phases for the Agaricus brasiliensis strain were observed. The in vivo basidiocarp antineoplasic average activity was 89.22%.

Mourao, Francielly; Linde, Giani Andrea; Messa, Valdeci; da Cunha Junior, Paulo Luiz; da Silva, Aristeu Vieira; da Eira, Augusto Ferreira; Colauto, Nelson Barros

2009-01-01

107

Purification andPartial Characterization ofaNocardia brasiliensis  

Microsoft Academic Search

gel electrophoresis. Theenzymeisinhibited byo-phenanthroline and8-hydroxyquinoline-5-sulfonic acidbutis notaffected byEDTA.Average values forits kinetic parameters were0.288 jxmol ofhemoglobin solubilized perminpermgofenzymeforVmaxand0.76 mM forK, using hemoglobin asthesubstrate. Theability ofNocardia brasiliensis tohydrolyze protein substrates constitutes afundamental criterion foritsdiffer- entiation fromother Nocardia specibs (5). Theenzymeor enzymes responsible forthis phenomenon havenever been characterized. Thepresent study reports thepurification of anextracellular protease fromN.brasiliensis anddescribes someofits characteristics. Thefunctions ofthis enzymeare unknown;

Extracellular Protease; VERN L. SCHRAMM

1984-01-01

108

Counting Yeast.  

ERIC Educational Resources Information Center

|Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)|

Bealer, Jonathan; Welton, Briana

1998-01-01

109

Yeast Infections  

MedlinePLUS

Candida is the scientific name for yeast. It is a fungus that lives almost everywhere, including in ... infection that causes white patches in your mouth Candida esophagitis is thrush that spreads to your esophagus, ...

110

Yeast Infection (Candidiasis)  

MedlinePLUS

newsletter | contact Share | Yeast Infection (Candidiasis) Information for adults A A A This is a candida (yeast) infection of the skin folds of the abdomen. Overview Candidiasis, commonly known as a yeast infection, is an infection with the common yeast ( ...

111

Yeast Droplets  

NASA Astrophysics Data System (ADS)

It is well known that the Young's law and surface tension govern the shape of liquid droplets on solid surfaces. Here we address through experiments and theory the shape of growing aggregates of yeast on agar substrates, and assess whether these ideas still hold. Experiments are carried out on Baker's yeast, with different levels of expressions of an adhesive protein governing cell-cell and cell-substrate adhesion. Changing either the agar concentration or the expression of this protein modifies the local contact angle of a yeast droplet. When the colony is small, the shape is a spherical cap with the contact angle obeying Young's law. However, above a critical volume this structure is unstable, and the droplet becomes nonspherical. We present a theoretical model where this instability is caused by bulk elastic effects. The model predicts that the transition depends on both volume and contact angle, in a manner quantitatively consistent with our experiments.

Nguyen, Baochi; Upadhyaya, Arpita; van Oudenaarden, Alexander; Brenner, Michael

2002-11-01

112

Antimutagenic effect of aqueous extract from Agaricus brasiliensis on culture of human lymphocytes.  

PubMed

The mushroom Agaricus brasiliensis (sun mushroom), native from the southeast of Brazil, is well known by its medicinal properties that include effects on diabetes, cholesterol levels, and osteoporosis. The antimutagenic effects of A. brasiliensis has been investigated recently and revealed some controversial results depending on the temperature by which the A. brasiliensis tea is obtained. In the present study, we evaluated the effect of the A. brasiliensis extract prepared in two different temperatures, 4°C and 25°C, on the doxorubicin-induced DNA strand breaks and chromosomal aberrations (CAs) in human lymphocytes. The results demonstrated that A. brasiliensis was able to reduce the DXR-induced DNA damage in both temperatures; however, the CA test was more sensitive to demonstrate a better reduction when the cells were treated with an extract obtained at 25°C. A. brasiliensis extract obtained in different temperatures exhibited antigenotoxic and anticlastogenic effects in human lymphocytes. PMID:23289788

Gameiro, Paula H; Nascimento, José S; Rocha, Beatriz H G; Piana, Clause F B; Santos, Raquel A; Takahashi, Catarina S

2013-01-05

113

Disseminated paracoccidioidomycosis in a Southern two-toed sloth (Choloepus didactylus).  

PubMed

A Southern two-toed sloth (Choloepus didactylus), originally acquired from French Guiana, died while maintained in quarantine in a pet store in Monterrey, Mexico. Large yeast cells with multiple buds compatible with Paracoccidioides brasiliensis were observed in disseminated granulomatous lesions in the lungs, liver, spleen and kidney. Transmission electron microscopical examination supported the diagnosis. This is the first report of paracoccidioidomycosis in a two-toed sloth. PMID:20961559

Trejo-Chávez, A; Ramírez-Romero, R; Ancer-Rodríguez, J; Nevárez-Garza, A M; Rodríguez-Tovar, L E

2010-10-18

114

Nocardia brasiliensis Cellulitis in a Heart Transplant Patient  

PubMed Central

Three months after undergoing heart transplantation, a 55-year-old man presented with N. brasiliensis cellulitis resulting from a splinter wound acquired during yard work. Surgical débridement was necessary before the infection responded to medical treatment. Although pulmonary nocardiosis is a well-documented complication of immunosuppressive therapy, this is the 1st report of a nocardial infection associated with primary skin involvement in a heart transplant patient. (Texas Heart Institute Journal 1990;17:133-5)

Sinnott, John T.; Holt, Douglas A.; Alverez, Carlos; Greene, John; Sweeney, Michael S.

1990-01-01

115

Fenologia reprodutiva e biologia da polinização de Canavalia brasiliensis Mart. ex Benth (Fabaceae)  

Microsoft Academic Search

Reproductive phenology and pollination biology of Canavalia brasiliensis Mart. ex Benth (Fabaceae). This work studied the phenology and biology of the pollination of C. brasiliensis in an area of its natural occurrence (Pocinhos - PB). Fifteen plants were marked and observed every two weeks for the study of phenology. For the study of floral biology and morphology, flowers and inflorescences

Roberta Sales Guedes; Zelma Glebya; Maciel Quirino; Edilma Pereira Gonçalves

116

In Vitro and In Vivo Activities of Antimicrobials against Nocardia brasiliensis  

Microsoft Academic Search

In Mexico mycetomas are mostly produced by Nocardia brasiliensis, which can be isolated from about 86% of cases. In the present work, we determined the sensitivities of 30 N. brasiliensis strains isolated from patients with mycetoma to several groups of antimicrobials. As a first screening step we carried out disk diffusion assays with 44 antimicrobials, including aminoglycosides, cephalosporins, penicillins, quinolones,

Alejandra Gomez-Flores; Oliverio Welsh; Salvador Said-Fernandez; Gerardo Lozano-Garza; Roman Erick Tavarez-Alejandro; Lucio Vera-Cabrera

2004-01-01

117

Opioid involvement in behavior modifications of mice infected with the parasitic nematode, Nippostrongylus brasiliensis  

Microsoft Academic Search

Several studies have documented the opiate effects of parasitic infection on experimental animals. The current study examined the relationships between infection with the intestinal nematode, Nippostrongylus brasiliensis with analgesia and activity levels. Male white mice infected with N. brasiliensis displayed a significant increase in thermal latency thresholds that rose through the duration of infection and subsided with its termination. Analgesia

Stephen C. Pryor; Carl Carter; Michel Mendes; Elizabeth Cherian

1998-01-01

118

High-level intracellular expression of hydroxynitrile lyase from the tropical rubber tree Hevea brasiliensis in microbial hosts.  

PubMed

(S)-Hydroxynitrile lyase (Hnl) from the tropical rubber tree Hevea brasiliensis catalyzes the formation of (S)-cyanohydrins from hydrocyanic acid and aldehydes or ketones. This enzyme accepts aliphatic, aromatic, and heterocyclic carbonyl compounds as substrates and is therefore considered a potent biocatalyst for the industrial production of optically active chemicals. Limitations in enzyme supply from natural resources were overcome by production of the enzyme in the microbial host systems Escherichia coli, Saccharomyces cerevisiae, and Pichia pastoris. Expression of Hnl in the prokaryotic system led to the formation of inclusion bodies whereas in both yeast hosts high levels of soluble protein were obtained. Highest yields were obtained in a high cell density batch fermentation of a P. pastoris transformant that expressed heterologous Hnl to about 50% of the soluble cytosolic protein. At a cell density of 100 g/liter cell dry weight, a volume yield of 22 g/liter of heterologous product was obtained. Attempts to produce the Hnl protein extracellularly with the yeast hosts by applying different leader peptide strategies were not successful. Immunofluorescence microscopy studies indicated that the secretion-directed heterologous Hnl protein accumulated in the plasma membrane forming aggregated clusters of inactive protein. PMID:9325140

Hasslacher, M; Schall, M; Hayn, M; Bona, R; Rumbold, K; Lückl, J; Griengl, H; Kohlwein, S D; Schwab, H

1997-10-01

119

Revalidation and redescription of Triatoma brasiliensis macromelasoma Galvão, 1956 and an identification key for the Triatoma brasiliensis complex (Hemiptera: Reduviidae: Triatominae).  

PubMed

Triatoma brasiliensis macromelasoma is revalidated based on the results of previous multidisciplinary studies on the Triatoma brasiliensis complex, consisting of crossing experiments and morphological, biological, ecological and molecular analyses. These taxonomic tools showed the closest relationship between T. b. macromelasoma and Triatoma brasiliensis brasiliensis. T. b. macromelasoma is redescribed based on specimens collected in the type locality and specimens from a F1 colony. The complex now comprises T. b. brasiliensis, T. b. macromelasoma, Triatoma melanica, Triatoma juazeirensis and Triatoma sherlocki. An identification key for all members of the complex is presented. This detailed comparative study of the morphological features of T. b. macromelasoma and the remaining members of the complex corroborates results from multidisciplinary analyses, suggesting that the subspecific status is applicable. This subspecies can be distinguished by the following combination of features: a pronotum with 1+1 narrow brownish-yellow stripes on the submedian carinae, not attaining its apex, hemelytra with membrane cells darkened on the central portion and legs with an incomplete brownish-yellow ring on the apical half of the femora. Because the T. brasiliensis complex is of distinct epidemiological importance throughout its geographic distribution, a precise identification of its five members is important for monitoring and controlling actions against Chagas disease transmission. PMID:24037202

Costa, Jane; Correia, Nathália Cordeiro; Neiva, Vanessa Lima; Gonçalves, Teresa Cristina Monte; Felix, Márcio

2013-09-01

120

Taxonomic and Functional Microbial Signatures of the Endemic Marine Sponge Arenosclera brasiliensis  

PubMed Central

The endemic marine sponge Arenosclera brasiliensis (Porifera, Demospongiae, Haplosclerida) is a known source of secondary metabolites such as arenosclerins A-C. In the present study, we established the composition of the A. brasiliensis microbiome and the metabolic pathways associated with this community. We used 454 shotgun pyrosequencing to generate approximately 640,000 high-quality sponge-derived sequences (?150 Mb). Clustering analysis including sponge, seawater and twenty-three other metagenomes derived from marine animal microbiomes shows that A. brasiliensis contains a specific microbiome. Fourteen bacterial phyla (including Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Cloroflexi) were consistently found in the A. brasiliensis metagenomes. The A. brasiliensis microbiome is enriched for Betaproteobacteria (e.g., Burkholderia) and Gammaproteobacteria (e.g., Pseudomonas and Alteromonas) compared with the surrounding planktonic microbial communities. Functional analysis based on Rapid Annotation using Subsystem Technology (RAST) indicated that the A. brasiliensis microbiome is enriched for sequences associated with membrane transport and one-carbon metabolism. In addition, there was an overrepresentation of sequences associated with aerobic and anaerobic metabolism as well as the synthesis and degradation of secondary metabolites. This study represents the first analysis of sponge-associated microbial communities via shotgun pyrosequencing, a strategy commonly applied in similar analyses in other marine invertebrate hosts, such as corals and algae. We demonstrate that A. brasiliensis has a unique microbiome that is distinct from that of the surrounding planktonic microbes and from other marine organisms, indicating a species-specific microbiome.

Trindade-Silva, Amaro E.; Rua, Cintia; Silva, Genivaldo G. Z.; Dutilh, Bas E.; Moreira, Ana Paula B.; Edwards, Robert A.; Hajdu, Eduardo; Lobo-Hajdu, Gisele; Vasconcelos, Ana Tereza; Berlinck, Roberto G. S.; Thompson, Fabiano L.

2012-01-01

121

Nippostrongylus brasiliensis: radioresistant IgE antibody-forming cells in infected rats  

SciTech Connect

In Nippostrongylus brasiliensis-infected rats, anti-N. brasiliensis IgE antibody production was observed at 20 weeks postinfection, long after the worms, as a source of antigen, had been expelled. The persistent IgE production was not abrogated after whole body irradiation (800 R) administered at 12 or 20 weeks, suggesting the participation of radioresistant IgE-forming cells. Help of T cells and recruitment of B memory cells in the irradiated rats seems to be ruled out by the findings that the irradiation completely inhibited the initiation of anti-N. brasiliensis IgE production in rats shortly after the infection with N. brasiliensis or after primary and secondary immunization with N. brasiliensis-antigen. Moreover, clearance of anti-N. brasiliensis IgE antibody from circulation did not seem to be crucially affected by the irradiation. The radioresistant cells forming anti-N. brasiliensis IgE were most productive in mesenteric lymph nodes as compared to other lymph nodes. The recognition of antigens fractionated by chromatography on Sephadex G-200 was the same for IgE-forming cells from rats 12 weeks after infection as for those from 3 weeks after infection. Based on these results, one of the mechanisms of persistent elevation of IgE antibody in the host infected with helminth parasites might be explained by the participation of radioresistant IgE-forming cells.

Watanabe, N.; Kobayashi, A.

1989-02-01

122

Yeast-Air Balloons  

NSDL National Science Digital Library

In this activity, learners make a yeast-air balloon to get a better idea of what yeast can do. Learners discover that the purpose of leaveners like yeast is to produce the gas that makes bread rise. Learners discover that as yeast feeds on sugar, it produces carbon dioxide which slowly fills the balloon.

Exploratorium, The

2012-03-10

123

A Feast for Yeast  

NSDL National Science Digital Library

In this activity on page 6 of the PDF, learners investigate yeast. Learners prepare an experiment to observe what yeast cells like to eat. Learners feed the yeast cells various ingredients in plain bread--water, flour, sugar, and salt--to discover yeast's favorite food.

Society, American C.

2000-01-01

124

Isolation and characterization of microsatellite markers in the Serra Spanish mackerel, Scomberomorus brasiliensis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thirteen nuclear-encoded microsatellites from a genomic DNA library of Serra Spanish mackerel, Scomberomorus brasiliensis, were isolated and characterized. The microsatellites include 10 perfect repeats (8 tetranucleotide and 2 dinucleotide) and 3 imperfect repeats (2 tetranucleotide and 1 dinucleo...

125

Black yeast-like fungi associated with Lethargic Crab Disease (LCD) in the mangrove-land crab, Ucides cordatus (Ocypodidae).  

PubMed

Lethargic Crab Disease (LCD) caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Brachyura: Ocypodidae) along the Brazilian coast, mainly in the Northeastern region. The disease was named after the symptoms of slow movement of infected crabs. Causative agents were suspected to be two black yeast-like fungi of the family Herpotrichiellaceae (ascomycete order Chaetothyriales), judged by infected tissue biopsies from moribund U. cordatus. The aim of the present study is to prove that two species are involved in the disease: the recently described black yeast Exophiala cancerae, but also a less virulent, hitherto undescribed fonsecaea-like species, introduced here as the novel species Fonsecaea brasiliensis. Strains were identified by ITS rDNA sequencing, and species borderlines were established by multilocus sequencing and AFLP analysis. Fonsecaea brasiliensis proved to be closely related to the pathogenic species Cladophialophora devriesii which originally was isolated from a systemic infection in a human patient. The virulence of F. brasiliensis is lower than that of E. cancerae, as established by artificial inoculation of mangrove crabs. PMID:22440399

Vicente, Vania A; Orélis-Ribeiro, R; Najafzadeh, M J; Sun, Jiufeng; Guerra, Raquel Schier; Miesch, Stephanie; Ostrensky, Antonio; Meis, Jacques F; Klaassen, Corné H; de Hoog, G S; Boeger, Walter A

2012-02-09

126

Phylogenetic Analysis Reveals a High Prevalence of Sporothrix brasiliensis in Feline Sporotrichosis Outbreaks  

PubMed Central

Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1?) loci in strains originated from Rio de Janeiro (RJ, n?=?15), Rio Grande do Sul (RS, n?=?10), Paraná (PR, n?=?4), São Paulo (SP, n?=?3) and Minas Gerais (MG, n?=?1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil.

Rodrigues, Anderson Messias; de Melo Teixeira, Marcus; de Hoog, G. Sybren; Schubach, Tania Maria Pacheco; Pereira, Sandro Antonio; Fernandes, Geisa Ferreira; Bezerra, Leila Maria Lopes; Felipe, Maria Sueli; de Camargo, Zoilo Pires

2013-01-01

127

In Vitro Activity of PNU-100766 (Linezolid), a New Oxazolidinone Antimicrobial, against Nocardia brasiliensis  

PubMed Central

The in vitro activity of a novel oxazolidinone, linezolid, was studied by comparing the activity of linezolid with those of amikacin, trimethoprim-sulfamethoxazole, and amoxicillin-clavulanic acid against 25 strains of Nocardia brasiliensis isolated from patients with mycetoma. All N. brasiliensis strains tested were sensitive to linezolid (MIC at which 90% of strains are inhibited [MIC90], 2 ?g/ml; MIC50, 1 ?g/ml). This antimicrobial might constitute a good alternative for treatment of actinomycetoma.

Vera-Cabrera, Lucio; Gomez-Flores, Alejandra; Escalante-Fuentes, Wendy G.; Welsh, Oliverio

2001-01-01

128

Phylogenetic analysis reveals a high prevalence of Sporothrix brasiliensis in feline sporotrichosis outbreaks.  

PubMed

Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1?) loci in strains originated from Rio de Janeiro (RJ, n = 15), Rio Grande do Sul (RS, n = 10), Paraná (PR, n = 4), São Paulo (SP, n =3) and Minas Gerais (MG, n = 1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil. PMID:23818999

Rodrigues, Anderson Messias; de Melo Teixeira, Marcus; de Hoog, G Sybren; Schubach, Tânia Maria Pacheco; Pereira, Sandro Antonio; Fernandes, Geisa Ferreira; Bezerra, Leila Maria Lopes; Felipe, Maria Sueli; de Camargo, Zoilo Pires

2013-06-20

129

In Vitro Activities of the New Antitubercular Agents PA-824 and BTZ043 against Nocardia brasiliensis  

PubMed Central

The in vitro activity of PA-824 and BTZ043 against 30 Nocardia brasiliensis isolates was tested. The MIC50 and MIC90 values for PA-824 were both >64 ?g/ml. The same values for BTZ043 were 0.125 and 0.250 ?g/ml. Given the MIC values for benzothiazinone (BTZ) compounds, we consider them good candidates to be tested in vivo against N. brasiliensis.

Campos-Rivera, Mayra Paola; Gonzalez-Martinez, Norma Alejandra; Ocampo-Candiani, Jorge; Cole, Stewart T.

2012-01-01

130

Vaginal Yeast Infections (For Parents)  

MedlinePLUS

... infection is simple and painless. What Is a Yeast Infection? A yeast infection, also known as candidiasis ( ... you can be treated appropriately. Do Guys Get Yeast Infections? Guys don't get vaginal yeast infections, ...

131

Drimanes from Drimys brasiliensis with leishmanicidal and antimalarial activity.  

PubMed

This paper evaluates CHCl3 and CH3OH extracts of the stem bark, branches and leaves of Drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of Leishmania amazonensis and Leishmania braziliensis promastigotes and Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl3 and CH3OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC50 ) values ranging from 39-100 µg/mL. The CHCl3 extract of the stem bark returned IC50 values of 39 and 40.6 µg/mL for L. amazonensis and L. braziliensis, respectively. The drimanes were relatively effective: 1-?-(p-coumaroyloxy)-polygodial produced IC50 values of 5.55 and 2.52 µM for L. amazonensis and L. braziliensis, respectively, compared with 1-?-(p-methoxycinnamoyl)-polygodial, which produced respective IC50 values of 15.85 and 17.80 µM. The CHCl3 extract demonstrated activity (IC50 of 3.0 µg/mL) against P. falciparum. The IC50 values of 1-?-(p-cumaroyloxyl)-polygodial and 1-?-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 µM, respectively, for the trophozoite strain. Therefore, the results suggest that D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents. PMID:23579790

Claudino, Vanessa Duarte; da Silva, Kesia Caroline; Cechinel Filho, Valdir; Yunes, Rosendo Augusto; Delle Monache, Franco; Giménez, Alberto; Salamanca, Efrain; Gutierrez-Yapu, David; Malheiros, Angela

2013-04-01

132

Yeast Infection during Pregnancy  

MedlinePLUS

... may be reprinted for personal, noncommercial use only. Yeast infection during pregnancy: Are over-the-counter treatments ... share your e-mail address Sign up Question Yeast infection during pregnancy: Are over-the-counter treatments ...

133

Yeast Infection (Vaginal)  

MedlinePLUS

... may be reprinted for personal, noncommercial use only. Yeast infection (vaginal) By Mayo Clinic staff Original Article: http://www.mayoclinic.com/health/yeast-infection/DS01182 Definition Symptoms Causes Risk factors Preparing ...

134

Yeast Education Network  

NSDL National Science Digital Library

The Yeast Education Network provides a variety of resources to facilitate use of the budding yeast Saccharomyces cerevisiae in undergraduate science curricula. Laboratory, classroom, and computer-based activities can be used with college and advanced high school students.

135

Yeast Based Sensors  

NASA Astrophysics Data System (ADS)

Since the first microbial cell sensor was studied by Karube et al. in 1977, many types of yeast based sensors have been developed as analytical tools. Yeasts are known as facultative anaerobes. Facultative anaerobes can survive in both aerobic and anaerobic conditions. The yeast based sensor consisted of a DO electrode and an immobilized omnivorous yeast. In yeast based sensor development, many kinds of yeast have been employed by applying their characteristics to adapt to the analyte. For example, Trichosporon cutaneum was used to estimate organic pollution in industrial wastewater. Yeast based sensors are suitable for online control of biochemical processes and for environmental monitoring. In this review, principles and applications of yeast based sensors are summarized.

Shimomura-Shimizu, Mifumi; Karube, Isao

136

Lager brewing yeast  

Microsoft Academic Search

Lager brewing yeast is a group of closely related strains of Saccharomyces pastorianus\\/S. carlsbergensis used for lager beer production all over the world, making it one of the most important industrial yeasts. The pure cultivation\\u000a of yeast was established in the early 1880’s with immediate practical success for lager brewing yeast. However, almost a century\\u000a would elapse before its genetics

Yukiko Kodama; Morten C. Kielland-Brandt; Jørgen Hansen

137

[Yeasts contaminating salmon roe].  

PubMed

Quantitative and species compositions of yeast contaminating eggs, fry and fingerlings of Salmo gairdneri Rich under artificial breeding have been studied. Prevalence of species of genera Candida, Rhodotorula, Cryptococcus and Debaryomyces is noted. Yeast isolated from perished eggs and sick fry do not possess pathogenic properties. Certain strains of yeast make stimulating effect on the studied microorganisms. PMID:8983527

Nagornaia, S S; Ignatova, E A; Isaeva, N M; Davydov, O N; Podgorski?, V S

138

Prions in Yeast  

PubMed Central

The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the “protein only” model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-? aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions.

Liebman, Susan W.; Chernoff, Yury O.

2012-01-01

139

Mapping of the T-Cell Epitope in the Major 43-Kilodalton Glycoprotein of Paracoccidioides brasiliensis Which Induces a Th-1 Response Protective against Fungal Infection in BALB\\/c Mice  

Microsoft Academic Search

immune response in mice to gp43 administered in complete Freund's adjuvant involves CD41 Th-1 lympho- cytes, secreting gamma interferon (IFN-g) and interleukin 2 (IL-2) but not IL-4 and IL-10. The T-cell epitope of this antigen was mapped to a 15-amino-acid peptide (P10) based on lymphoproliferations with primed cells from three different haplotypes and on a computer-assisted protein analysis. The structural

CARLOS P. TABORDA; MARIA A. JULIANO; ROSANA PUCCIA; MARCELLO FRANCO; LUIZ R. TRAVASSOS

1998-01-01

140

Functional and structural optimization of the respiratory system of the bat Tadarida brasiliensis (Chiroptera, Molossidae): does airway geometry matter?  

Microsoft Academic Search

We studied structure and function of the respiratory system in the bat Tadarida brasiliensis and compared it with those of two species of rodents, Abrothrix andinus and A. olivaceus. Tadarida brasiliensis had lower resting oxygen consumption, but higher maximum oxygen consumption and aerobic scope, than the rodents. The blood-gas barrier of the bat was thinner and its relative lung size

Mauricio Canals; Cristian Atala; Ricardo Olivares; Francisco Guajardo; Daniela P. Figueroa; Pablo Sabat; Mario Rosenmann

2005-01-01

141

Interaction between Linepithema micans (Hymenoptera: Formicidae) and Eurhizococcus brasiliensis (Hemiptera: Margarodidae) in vineyards.  

PubMed

Eurhizococcus brasiliensis (Wille) (Hemiptera: Margarodidae) is a soil scale that is considered the main pest of vineyards in Brazil. The ant Linepithema micans (Forel) (Hymenoptera: Formicidae) is frequently found associated with this species of scale in infested areas. The effect of the presence of L. micans on the infestation and dispersal capacity of E. brasiliensis on vine roots was measured in a greenhouse, using Paulsen 1103 rootstock seedlings planted in simple and double "Gallotti Cages." Treatments measured were: infestation of roots with E. brasiliensis or L. micans, and infestation with both species together. In the experiment using simple Gallotti Cages, with E. brasiliensis associated with L. micans, higher mean numbers of cysts and ants per plant were recorded, a result significantly different from that found for infestation with scale only. When double Gallotti Cages were used, first-instar nymphs were transported between the cages. The results showed that L. micans transports and aids in the attachment of E. brasiliensis to vine plants. PMID:23726055

Nondillo, Aline; Sganzerla, Vânia Maria Ambrosi; Bueno, Odair Correa; Botton, Marcos

2013-06-01

142

Reconstructing the locomotor repertoire of Protopithecus brasiliensis. I. Body size.  

PubMed

An accurate body size estimate is essential for reconstructing and interpreting many aspects of the paleobiology of an extinct taxon. With this in mind, the purpose of this study is two-fold: first, to create statistically robust predictive regression equations for body mass, total body length, and head and body length from postcranial elements using a platyrrhine reference sample, data that do not exist elsewhere in the literature; and, second, to apply those regression equations to the "giant" subfossil platyrrhine Protopithecus brasiliensis, a little-studied taxon represented by a nearly complete skeleton. Building on results of previous work with other primate groups, different skeletal elements, subgroups of the reference sample, and regression models lead to different body size estimates with different standard errors and prediction errors. However, relatively tight clusters of estimates around 20 kg, total length of 1,675 mm, and head and body length of 710 mm are obtained, placing the fossil in the size range of a large male baboon. While not quite as large as the original 25 kg body mass estimate for the fossil, this new estimate is still approximately 150% larger than the largest living New World monkey. Confirmation of its place in a large-bodied size class of platyrrhines has a profound effect on reconstructing the locomotor repertoire of Protopithecus and the evolutionary trajectory of the alouattin lineage. PMID:22042663

Halenar, Lauren B

2011-11-01

143

Reconstructing the locomotor repertoire of Protopithecus brasiliensis. II. Forelimb morphology.  

PubMed

The majority of previous publications have suggested that the large-bodied subfossil Protopithecus brasiliensis was a suspensory ateline with a locomotor repertoire similar to that of extant Ateles and Brachyteles. This is unexpected, as the cranial morphology of Protopithecus is very similar to Alouatta, a genus usually classified as a deliberate quadrupedal climber. Complicating matters further, as Protopithecus is twice as large as Ateles and Brachyteles, its ability to be as suspensory as those two genera is suspect and a terrestrial component of the locomotor repertoire has also been hypothesized. The forelimbs of Protopithecus, while relatively elongated as would be expected in a suspensory animal, are also quite robust and show several adaptations for climbing. To test these hypotheses about the fossil locomotor repertoire, three-dimensional geometric morphometric techniques were used to quantify the shapes of the fossil distal humerus and proximal ulna and then compare them to a broad sample of extant primates with varying body sizes and locomotor patterns. Results indicate that Protopithecus is similar to Ateles and Brachyteles in terms of its forelimb joint surface morphology; however, the overall locomotor repertoire of the fossil is reconstructed as more flexible to include forelimb suspension, climbing, and potentially some terrestrial ground use. The combination of suspensory locomotion and quadrupedal climbing supported here indicates the beginnings of the evolutionary transition from a more acrobatic style of locomotion in the last common ancestor of alouattins and atelins to the current pattern of howler locomotion. PMID:22042627

Halenar, Lauren B

2011-11-01

144

Activation of the Na+, K(+)-ATPase in Narcine brasiliensis.  

PubMed Central

The in vivo activation and turnover rates of the sodium pump (Na+, K(+)-ATPase) were investigated in the electrocytes of the electric organ of the elasmobranch Narcine brasiliensis. The Narcine electric organ appears to be an excellent model for the study of sodium pump activation in an excitable tissue. The sodium transmembrane gradient and high-energy phosphagens were concurrently measured by 23Na and 31P NMR spectroscopy. The resting electric organ, which depends primarily on anaerobic metabolism, displays a high concentration of phosphocreatine (PCr). It has an intracellular sodium concentration ([Na+]i) of 20 +/- 10 milliequivalents/liter as estimated by NMR. Electrical stimulation of the nerves innervating the electric organ results in an increase in [Na+]i in the electrolyte and rapid depletion of PCr. Ouabain causes an 85% decrease in utilization of high-energy phosphagens, indicating that rapid PCr turnover in this tissue is mainly due to Na+, K(+)-ATPase activity. From these data we can determine that the rate of sodium pump turnover increases by greater than 3 orders of magnitude within several hundred milliseconds. In excised unstimulated electric organ slices, changes in [Na+]i equivalent to those occurring with stimulation, but induced by hyperosmolar conditions, do not result in increased PCr hydrolysis. We conclude that cholinergic stimulation of the electric organ causes a rapid and extremely large increase in sodium pump turnover, which is regulated predominantly by factors other than [Na+]i. Images

Blum, H; Nioka, S; Johnson, R G

1990-01-01

145

Temporal auditory summation in the echolocating bat, Tadarida brasiliensis.  

PubMed

Auditory thresholds improve with increasing signal duration within the maximum integration time of the auditory system, a phenomenon called temporal summation. The temporal summation function is a basic characteristic of particular relevance for bat sonar, as it determines the ability to detect targets with short echolocation calls. Temporal summation was studied in 6 Mexican free-tailed bats (Tadarida brasiliensis) in a forced two-choice behavioural test. Masked auditory thresholds for 40-kHz test tone pulses with durations between 2 ms and 400 ms were determined in broadband noise of two different spectrum levels (-18 dB, +17 dB). At both masker levels, thresholds decreased by considerably more than 10 dB per decade of duration. The time constants of the summation functions, which are a measure of the maximum integration time, shortened significantly with increasing masker level from 62 ms to 14 ms. The steep summation functions are only partly accounted for by spectral splatter. This suggests that the bats are capable of a neural overintegration of sound intensity. Finally, it is shown that such short time constants are typical for echolocating animals, and the implications of the found summation functions for echolocation are considered. PMID:7928724

Schmidt, S; Thaller, J

1994-06-15

146

Metabolic routes affecting rubber biosynthesis in Hevea brasiliensis latex  

PubMed Central

The cytosolic mevalonate (MVA) pathway in Hevea brasiliensis latex is the conventionally accepted pathway which provides isopentenyl diphosphate (IPP) for cis-polyisoprene (rubber) biosynthesis. However, the plastidic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway may be an alternative source of IPP since its more recent discovery in plants. Quantitative RT-PCR (qRT-PCR) expression profiles of genes from both pathways in latex showed that subcellular compartmentalization of IPP for cis-polyisoprene synthesis is related to the degree of plastidic carotenoid synthesis. From this, the occurrence of two schemes of IPP partitioning and utilization within one species is proposed whereby the supply of IPP for cis-polyisoprene from the MEP pathway is related to carotenoid production in latex. Subsequently, a set of latex unique gene transcripts was sequenced and assembled and they were then mapped to IPP-requiring pathways. Up to eight such pathways, including cis-polyisoprene biosynthesis, were identified. Our findings on pre- and post-IPP metabolic routes form an important aspect of a pathway knowledge-driven approach to enhancing cis-polyisoprene biosynthesis in transgenic rubber trees.

Chow, Keng-See; Mat-Isa, Mohd.-Noor; Bahari, Azlina; Ghazali, Ahmad-Kamal; Alias, Halimah; Mohd.-Zainuddin, Zainorlina; Hoh, Chee-Choong; Wan, Kiew-Lian

2012-01-01

147

Royal sun medicinal mushroom, Agaricus brasiliensis Ka21 (higher Basidiomycetes), as a functional food in humans.  

PubMed

The Royal Sun medicinal mushroom, Agaricus brasiliensis, is used as a natural health product. In Japan, however, the quality control of some of these mushroom products has been viewed as a safety problem. Focusing on the quality control of A. brasiliensis KA21, we have performed several safety studies. To date, we have established evidence that this mushroom can be used safely as an immunostimulant and to mediate biochemical parameters associated with obesity or diabetes. Furthermore, to improve the manufacturing process of this mushroom, we have studied the relationship between its pharmaceutical actions and the conditions of its cultivation and thermal management. The purpose of this review is to report the findings of basic and clinical studies of the fruit body of A. brasiliensis KA21. PMID:23796215

Yamanaka, Daisuke; Liu, Ying; Motoi, Masuro; Ohno, Naohito

2013-01-01

148

Antiherpetic activity of an Agaricus brasiliensis polysaccharide, its sulfated derivative and fractions.  

PubMed

Agaricus brasiliensis is an edible mushroom, traditionally used for the treatment of several diseases. In this paper, a polysaccharide (PLS) from A. brasiliensis, its carboxymethylated (CPLS) and sulfated (SPLS) derivatives, as well as, fractions (F1-F3) obtained from the PLS were investigated for their effect in the replication of herpes simplex virus and bovine herpes virus in HEp-2 cell cultures. The PLS, SPLS and F3 inhibited both virus strains similarly, in a dose-dependent curve. F1, F2 and CPLS did not show significant effect even at higher concentrations. All the compounds showed neither virucidal or viral adsorption inhibition activities nor effect when cells were treated prior to infection. Our study demonstrated that the extracts of A. brasiliensis, can be promising for future antiviral drug design and its biotechnological production is economically feasible. PMID:23043759

Yamamoto, Kristie Aimi; Galhardi, Lígia Carla Faccin; Rincão, Vinícius Pires; Soares, Sandra de Aguiar; Vieira, Icaro Gusmão Pinto; Ricardo, Nágila Maria Pontes Silva; Nozawa, Carlos; Linhares, Rosa Elisa Carvalho

2012-10-05

149

Transformation of Yeast  

Microsoft Academic Search

A stable leu2- yeast strain has been transformed to LEU2+ by using a chimeric ColE1 plasmid carrying the yeast leu2 gene. We have used recently developed hybridization and restriction endonuclease mapping techniques to demonstrate directly the presence of the transforming DNA in the yeast genome and also to determine the arrangement of the sequences that were introduced. These studies show

Albert Hinnen; James B. Hicks; Gerald R. Fink

1978-01-01

150

Population Growth in Yeasts  

NSDL National Science Digital Library

This lesson is the second of two that explore cellular respiration and population growth in yeasts. In the first lesson, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arose during the first lesson and its associated activity, in this lesson students work in small groups to design experiments that will determine how environmental factors affect yeast population growth.

Engineering K-Ph.d. Program

151

Potentiated reagin response to egg albumin in Nippostrongylus brasiliensis infected rats  

PubMed Central

The potentiating effect of Nippostrongylus brasiliensis infection on the serum levels of reagin present in rats sensitized with egg albumin and Bordetella pertussis vaccine was examined to show at which stages following sensitization the increased response could be provoked by infection. It was found that the potentiated titres of anti-egg albumin rat reagin were related to those levels of egg albumin reagin present at the time of infection. Re-infection with N. brasiliensis appeared to prolong the presence of high levels of circulating rat reagin to egg albumin.

Orr, T. S. C.; Riley, Patricia A.; Doe, J. E.

1972-01-01

152

Nucleic Acid Amplification in Yeast.  

National Technical Information Service (NTIS)

Plasmid DNA from single yeast colonies was efficiently amplified using rolling circle amplification (RCA). The amplified DNA was directly used for restriction digestion, DNA sequencing, and yeast transformation. The RCA of plasmid DNA from single yeast co...

W. Farmerie W. Y. Song X. Ding

2004-01-01

153

Moonlighting Proteins in Yeasts  

PubMed Central

Proteins able to participate in unrelated biological processes have been grouped under the generic name of moonlighting proteins. Work with different yeast species has uncovered a great number of moonlighting proteins and shown their importance for adequate functioning of the yeast cell. Moonlighting activities in yeasts include such diverse functions as control of gene expression, organelle assembly, and modification of the activity of metabolic pathways. In this review, we consider several well-studied moonlighting proteins in different yeast species, paying attention to the experimental approaches used to identify them and the evidence that supports their participation in the unexpected function. Usually, moonlighting activities have been uncovered unexpectedly, and up to now, no satisfactory way to predict moonlighting activities has been found. Among the well-characterized moonlighting proteins in yeasts, enzymes from the glycolytic pathway appear to be prominent. For some cases, it is shown that despite close phylogenetic relationships, moonlighting activities are not necessarily conserved among yeast species. Organisms may utilize moonlighting to add a new layer of regulation to conventional regulatory networks. The existence of this type of proteins in yeasts should be taken into account when designing mutant screens or in attempts to model or modify yeast metabolism.

Gancedo, Carlos; Flores, Carmen-Lisset

2008-01-01

154

Feeding convergence in South American and African zooplanktivorous cichlids Geophagus brasiliensis and Tilapia rendalli  

Microsoft Academic Search

Acará, Geophagus brasiliensis, and red-breasted bream, Tilapia rendalli, are important planktivorous cichlids in southern Brazilian lakes and reservoirs. In laboratory experiments, I quantified behavior and selectivity of different sizes of these two fish feeding on lake zooplankton. Feeding behavior depended on fish size. Fish 70 mm were pump-filter feeders. Replicate 1 h feeding trials revealed that, as the relative proportions

Xavier Lazzaro

1991-01-01

155

Capítulo V LA RESPUESTA DEL HUÉSPED A LA INFECCIÓN POR Nocardia brasiliensis  

Microsoft Academic Search

Nocardia brasiliensis is the most frequently isolated bacterium from human actinomycetoma cases in Mexico. This organism lives as a saprophyte in soil and enters the skin by traumatic inoculation. Host response to this infection is a remarkable inflammatory accumulation of granulocytes around the bacteria. Chronic infection up to seven years in humans is also characterized by multiple microabscesses separated by

Mario Cesar; Salinas Carmona; Nuevo León

156

Low-cost and low maintenance preservation of Agaricus brasiliensis cultures.  

PubMed

Agaricus brasiliensis cultures quickly lose viability when stored at cool temperatures, even for a short period of time. We evaluated several low-cost preservation methods using varied substrates, preservation solutions, and storage temperatures. Agaricus brasiliensis was intolerant to freezing temperatures, making liquid nitrogen use and deep-freezing methods impossible for its preservation. The best preservation conditions for the A. brasiliensis CS1 strain tested in this study were obtained by using rice as substrate and water as preservation solution, with storage at room temperature or when using soil, mushroom cultivation compost, or rice and stored at 10 °C without preservation solution. Those cultures that were reactivated showed the same productivity attributes as the control. In addition, no effect on productivity or biological efficiency was observed through successive subculturing of the strain (CS1). Parboiled rice was successfully used for other A. brasiliensis strains (CS2, CS5, CS7, CS9, and CS10), and also for Pleurotus ostreatus, P. sajor-caju, and Lentinula edodes. PMID:22806115

Maia, Scheila C; Toledo, Rômulo C C; Almeida, Ana Paula M M; da Silva, Romildo; Rinker, Danny Lee; Dias, Eustáquio S

2012-04-06

157

High Altitude Flights of the Free-Tailed Bat, 'Tadarida brasiliensis', Observed with Radar.  

National Technical Information Service (NTIS)

Both search and height finding radars were used to observe the airborne behavior of Mexican Free-tailed bats, Tadarida brasiliensis mexicana, near several caves in the southwestern United States. Radar echoes from dense groups of bats covered areas as lar...

T. C. Williams L. C. Ireland J. M. Williams

1973-01-01

158

Evaluation of thermal behavior of latex membranes from genetically improved rubber tree ( Hevea brasiliensis)  

Microsoft Academic Search

Thermal stability, thermal decomposition process, residual mass, temperature of glass transition (Tg) and temperature dependence of storage modulus (E’), were determined for latex membranes prepared from six clones of Hevea brasiliensis: IAC 331, IAC 332, IAC 333 and IAC 334 grown at experimental plantations of Instituto Agronômico de Campinas (IAC) in Votuporanga, São Paulo State, Brazil. Latex membranes from GT1

L. C. S. de Oliveira; E. J. de Arruda; S. P. Favaro; R. B. da Costa; P. S. Gonçalves; A. E. Job

2006-01-01

159

Diversity of fungal endophytes in leaves and stems of wild rubber trees ( Hevea brasiliensis) in Peru  

Microsoft Academic Search

Endophytic fungi isolates from foliage and sapwood of Hevea brasiliensis were studied to determine the total diversity of endophytes inhabiting leaves and sapwood, and differences between respective endophyte communities found in leaves and sapwood. Endophytes were recovered from 72% (161) of the 225 samples, with a total of 175 isolates. Sequence data from ITS and LSU nrDNA revealed 58 distinct

Romina Gazis; Priscila Chaverri

2010-01-01

160

IL-13 receptor alpha-2 regulates the immune and functional response to Nippostrongylus brasiliensis infection  

Technology Transfer Automated Retrieval System (TEKTRAN)

IL-13 has a prominent role in host defense against the gastrointestinal nematode, Nippostrongylus brasiliensis; however, the role of IL-13 alpha2 in the immune and functional response to enteric infection is not known. In the current study, we investigated changes in smooth muscle and epithelial ce...

161

Growth, photosynthetic performance and shade adaptation of rubber (Hevea brasiliensis) grown in natural shade  

Microsoft Academic Search

Summary We compared growth, photosynthetic perfor- mance and shade adaptation of rubber (Hevea brasiliensis Muell. Arg.) plants growing in natural shade (33, 55 and 77% reduction in incoming radiation) to control plants growing in full sunlight. Stem diameter and plant height, measured over a 15-month period, were greatest in plants grown in full sunlight, and both parameters decreased with increasing

A. M. W. K. SENEVIRATHNA; C. M. STIRLING; V. H. L. RODRIGO

162

Black thread disease, control measures and yield stimulation in Hevea brasiliensis in Liberia  

Microsoft Academic Search

Described are investigations, carried out in 1963 to 1971 in Hevea brasiliensis at the Firestone Plantation at Harbel in Liberia. Studied was the tapping panel disease, black thread, caused by the fungus Phytophthora palmivora. The emphasis of the investigations was on control of the disease with the fungicide captafol (Difolatan). Another line of investigation was yield stimulation with 2,4-D (salts

J. Schreurs

1972-01-01

163

Genotoxic and antigenotoxic evaluation of extracts from Arenosclera brasiliensis, a Brazilian marine sponge  

Microsoft Academic Search

The marine environment is a rich source of biological active compounds and the sponges can be considered the most productive one. This diversity gives rise to unique chemical compounds with potential pharmacological properties. Our study is focused on the genotoxic and antigenotoxic evaluation of two crude extracts obtained from the Brazilian endemic marine sponge Arenosclera brasiliensis. Salmonella typhimurium reverse mutation

L. Stankevicins; C. Aiub; L. C. de Santa Maria; G. Lobo-Hajdu; I. Felzenszwalb

2008-01-01

164

Genetic Improvement of Baker's Yeasts  

Microsoft Academic Search

Yeasts have been used for many thousands of years to produce leavened bread. Nowadays the production of baker's yeast biomass represents a highly competitive multi-billion dollar global industry. The environmental conditions that prevail during manufacture and application of baker's yeasts, coupled with the sheer variety of bread making processes and recipes used around the world, place considerable demands on yeasts.

Paul V. Attfield; Philip J. L. Bell

2003-01-01

165

TRP channels in yeast.  

PubMed

Microbes have made numerous contributions to the study of biology and medicine. Those contributions also include many original discovery's in the study of ion channels often thought as the province of neuroscientists or cardiophysiologists. Yeast have long been used as a model organism and TRP channel genes and their transmembrane products touted as the "vanguards of the sensory system" can be identified in the genomes of many yeasts. This article aims to review the study of these TRP channels in yeast their discovery, electrophysiological properties and physiological function. PMID:21290303

Kaleta, Marta; Palmer, Christopher

2011-01-01

166

Assessment of plant lectin antifungal potential against yeasts of major importance in medical mycology.  

PubMed

The search for new compounds with antifungal activity is accelerating due to rising yeast and fungal resistance to commonly prescribed drugs. Among the molecules being investigated, plant lectins can be highlighted. The present work shows the potential of six plant lectins which were tested in vitro against yeasts of medical importance, Candida albicans, Candida tropicalis, Candida parapsilosis, Cryptococcus gattii, Cryptococcus neoformans, Malassezia pachydermatis, Rhodotorula sp. and Trichosporon sp. Broth microdilution susceptibility testing was performed in accordance with standard protocols to evaluate antifungal activity. Minimum inhibitory concentration (MIC) was determined at 80% yeast growth inhibition, whereas the minimum fungicidal concentration (MFC) was evaluated after making the subcultures of each dilution. Only C. parapsilosis growth was inhibited by the lectins tested. Abelmoschus esculentus lectin showed the highest MIC (0.97 ?g ml(-1)). Lectins from Canavalia brasiliensis, Mucuna pruriens and Clitoria fairchildiana presented the highest MFC at (3.90 ?g ml(-1)). These results encourage further studies with wider yeast strain selections, and open new perspectives for the development of pharmacological molecules. PMID:23161017

Klafke, Gabriel Baracy; Moreira, Gustavo Marçal Schmitt Garcia; Monte, Leonardo Garcia; Pereira, Juliano Lacava; Brandolt, Tchana Martinez; Xavier, Melissa Orzechowski; Santi-Gadelha, Tatiane; Dellagostin, Odir Antonio; Pinto, Luciano da Silva

2012-11-19

167

Changes in kinematics and aerodynamics over a range of speeds in Tadarida brasiliensis, the Brazilian free-tailed bat.  

PubMed

To date, wake measurements using particle image velocimetry (PIV) of bats in flight have studied only three bat species, all fruit and nectar feeders. In this study, we present the first wake structure analysis for an insectivorous bat. Tadarida brasiliensis, the Brazilian free-tailed bat, is an aerial hunter that annually migrates long distances and also differs strikingly from the previously investigated species morphologically. We compare the aerodynamics of T. brasiliensis with those of other, frugivorous bats and with common swifts, Apus apus, a bird with wing morphology, kinematics and flight ecology similar to that of these bats. The comparison reveals that, for the range of speeds evaluated, the cyclical pattern of aerodynamic forces associated with a wingbeat shows more similarities between T. brasiliensis and A. apus than between T. brasiliensis and other frugivorous bats. PMID:22258554

Hubel, Tatjana Y; Hristov, Nickolay I; Swartz, Sharon M; Breuer, Kenneth S

2012-01-18

168

Changes in kinematics and aerodynamics over a range of speeds in Tadarida brasiliensis, the Brazilian free-tailed bat  

PubMed Central

To date, wake measurements using particle image velocimetry (PIV) of bats in flight have studied only three bat species, all fruit and nectar feeders. In this study, we present the first wake structure analysis for an insectivorous bat. Tadarida brasiliensis, the Brazilian free-tailed bat, is an aerial hunter that annually migrates long distances and also differs strikingly from the previously investigated species morphologically. We compare the aerodynamics of T. brasiliensis with those of other, frugivorous bats and with common swifts, Apus apus, a bird with wing morphology, kinematics and flight ecology similar to that of these bats. The comparison reveals that, for the range of speeds evaluated, the cyclical pattern of aerodynamic forces associated with a wingbeat shows more similarities between T. brasiliensis and A. apus than between T. brasiliensis and other frugivorous bats.

Hubel, Tatjana Y.; Hristov, Nickolay I.; Swartz, Sharon M.; Breuer, Kenneth S.

2012-01-01

169

Yeast infections (image)  

MedlinePLUS

Yeast infections may follow a course of antibiotics that were prescribed for another purpose. The antibiotics change the normal "balance" between organisms in the vagina by suppressing the growth of protective bacteria that normally have an antifungal effect.

170

Mutant yeast on drugs  

Microsoft Academic Search

Analyzing drug-treated and mutant yeast cells with the new tools of genomics enables the identification of drug targets and should improve the odds of developing useful therapeutics (pages 1293–1301).

David J. Lockhart

1998-01-01

171

[Aspects of yeast biodiversity].  

PubMed

Yeast biodiversity represents a dynamic scientific domain characterized by permanent emerging theories and accumulation of new data. Identification of genome structure for a number of yeast species and elucidation of regulatory pathways for species-specific metabolic networks, lead to development of numerous applications of yeasts in industry, biotechnology, therapeutics and bioremediation. The studies of the scientific community were long time focused on Saccharomyces cerevisae due mainly to its use in food production. Therefore, the species belonging to Saccharomyces genus became reference points for genomics and biodiversity studies. During last decades there is a growing interest for yeast species able to produce biomass by assimilating or degrading various compounds such as methanol, hydrocarbons, wood hydrolisates and other residues or by-products from different industries. PMID:23745219

Csutak, Ortansa; Vassu, Tatiana

172

Yeast expression platforms  

Microsoft Academic Search

Yeasts provide attractive expression platforms. They combine ease of genetic manipulations and the option for a simple fermentation\\u000a design of a microbial organism with the capabilities of an eukaryotic organism to secrete and to modify a protein according\\u000a to a general eukaryotic scheme. For platform applications, a range of yeast species has been developed during the last decades.\\u000a We present

Erik Böer; Gerhard Steinborn; Gotthard Kunze; Gerd Gellissen

2007-01-01

173

Nitrile Metabolizing Yeasts  

NASA Astrophysics Data System (ADS)

Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing enzymes of yeasts.

Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

174

IL13, IL4R?, and Stat6 Are Required for the Expulsion of the Gastrointestinal Nematode Parasite Nippostrongylus brasiliensis  

Microsoft Academic Search

Although IL-4 induces expulsion of the gastrointestinal nematode parasite, Nippostrongylus brasiliensis, from immunodeficient mice, this parasite is expelled normally by IL-4-deficient mice. This apparent paradox is explained by observations that IL-4 receptor ? chain (IL-4R?)-deficient mice and Stat6-deficient mice fail to expel N. brasiliensis, and a specific antagonist for IL-13, another activator of Stat6 through IL-4R?, prevents worm expulsion. Thus,

Joseph F Urban Jr.; Nancy Noben-Trauth; Debra D Donaldson; Kathleen B Madden; Suzanne C Morris; Mary Collins; Fred D Finkelman

1998-01-01

175

Differences in Cell Morphometry, Cell Wall Topography and Gp70 Expression Correlate with the Virulence of Sporothrix brasiliensis Clinical Isolates  

PubMed Central

Sporotrichosis is a chronic infectious disease affecting both humans and animals. For many years, this subcutaneous mycosis had been attributed to a single etiological agent; however, it is now known that this taxon consists of a complex of at least four pathogenic species, including Sporothrix schenckii and Sporothrix brasiliensis. Gp70 was previously shown to be an important antigen and adhesin expressed on the fungal cell surface and may have a key role in immunomodulation and host response. The aim of this work was to study the virulence, morphometry, cell surface topology and gp70 expression of clinical isolates of S. brasiliensis compared with two reference strains of S. schenckii. Several clinical isolates related to severe human cases or associated with the Brazilian zoonotic outbreak of sporotrichosis were genotyped and clustered as S. brasiliensis. Interestingly, in a murine subcutaneous model of sporotrichosis, these isolates showed a higher virulence profile compared with S. schenckii. A single S. brasiliensis isolate from an HIV-positive patient not only showed lower virulence but also presented differences in cell morphometry, cell wall topography and abundant gp70 expression compared with the virulent isolates. In contrast, the highly virulent S. brasiliensis isolates showed reduced levels of cell wall gp70. These observations were confirmed by the topographical location of the gp70 antigen using immunoelectromicroscopy in both species. In addition, the gp70 molecule was sequenced and identified using mass spectrometry, and the sequenced peptides were aligned into predicted proteins using Blastp with the S. schenckii and S. brasiliensis genomes.

Castro, Rafaela A.; Kubitschek-Barreira, Paula H.; Teixeira, Pedro A. C.; Sanches, Glenda F.; Teixeira, Marcus M.; Quintella, Leonardo P.; Almeida, Sandro R.; Costa, Rosane O.; Camargo, Zoilo P.; Felipe, Maria S. S.; de Souza, Wanderley; Lopes-Bezerra, Leila M.

2013-01-01

176

Oxygen requirements of yeasts.  

PubMed

Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly mu max, 0.03 and 0.05 h-1, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth. PMID:2082825

Visser, W; Scheffers, W A; Batenburg-van der Vegte, W H; van Dijken, J P

1990-12-01

177

Disseminated Sporothrix brasiliensis infection with endocardial and ocular involvement in an HIV-infected patient.  

PubMed

Disseminated sporotrichosis occurs in individuals with impaired cellular immunity, such as in cases of neoplasia, transplantation, diabetes, and especially, acquired immunodeficiency syndrome. This report presents a 32-year-old Brazilian human immunodeficiency virus (HIV)-infected patient who developed a protracted condition of disseminated sporotrichosis with endocarditis, bilateral endophthalmitis, and lymphatic involvement. He needed cardiac surgery to replace the mitral valve. Sporothrix brasiliensis isolates were recovered from cultures of subcutaneous nodules and mitral valve fragments. Species identification was based on classical and molecular methods. The patient received amphotericin B for 52 days and subsequently, oral itraconazole. He remains asymptomatic, and he is on maintenance therapy with itraconazole. Despite his positive clinical outcome, he developed bilateral blindness. To our knowledge, this case is the first report of endocarditis and endophthalmitis caused by S. brasiliensis. PMID:22403321

Silva-Vergara, Mario León; de Camargo, Zoilo Pires; Silva, Patricia Ferreira; Abdalla, Michel Reis; Sgarbieri, Ricardo Nilsson; Rodrigues, Anderson Messias; dos Santos, Keila Cristina; Barata, Cristina Hueb; Ferreira-Paim, Kennio

2012-03-01

178

Morphological studies on the infraciliature of a planktonic ciliate, Tintinnopsis brasiliensis (Ciliophora: Tintinina)  

NASA Astrophysics Data System (ADS)

A poorly-described marine planktonic ciliate, Tintinnopsis brasiliensis Kofoid & Campbell, 1929, collected from the Taiping Cape of Qingdao, China, was morphologically investigated based on permanent preparation after protargol impregnation and was compared with other related congeners. According to the infraciliature, three ciliary groups can be recognized, which reveals a very stable structure among specimens and denotes that the pattern of infraciliature is, apart from the features of the lorica, a highly reliable criterion for species identification.

Cai, Shengfang; Song, Weibo; Xu, Dapeng; Chiang, Kuoping

2006-01-01

179

Immune Response to Nocardia brasiliensis Extracellular Antigens in Patients with Mycetoma  

Microsoft Academic Search

The ability of culture-filtrate proteins to induce a cellular immune response in infected mice and humans was investigated.\\u000a A crude extract culture filtrate of Nocardia brasiliensis (CFA) and five semi-purified CFA fractions (P1, P2, P3, P4, P5) were used to stimulate BALB\\/c mice spleen-cell cultures.\\u000a The animals were divided into three groups: the first group was infected with 1 × 107 CFU

Bárbara Castro-Matteotti; Lucio Vera-Cabrera; Jorge Ocampo-Candiani; Adrián Rendón; Mario C. Salinas-Carmona; Oliverio Welsh

2008-01-01

180

Adsorption of copper on rubber ( Hevea brasiliensis) leaf powder: Kinetic, equilibrium and thermodynamic studies  

Microsoft Academic Search

The adsorption of Cu(II) ions from aqueous solution by rubber (Hevea brasiliensis) leaf powder (RHBL) was studied in a batch adsorption system. Characteristics of RHBL such as pH of aqueous slurry, pH of zero point charge (pHZPC), surface area and pore diameter, Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) were investigated. Factors influencing adsorption

W. S. Wan Ngah; M. A. K. M. Hanafiah

2008-01-01

181

Dietary energetics of the insectivorous Mexican free-tailed bat ( Tadarida brasiliensis ) during pregnancy and lactation  

Microsoft Academic Search

Stomach content analysis of 20 pregnant (x body mass=13.4 g) and 18 lactating (x body mass=11.5 g) female Tadarida brasiliensis revealed that the diet, expressed as percent volume, consists largely of lepidopterans, coleopterans, hymenopterans, and dipterans, in decreasing order of importance. We found no significant difference in the diet of pregnant and lactating females when expressed as percent volume. However,

T. H. Kunz; J. O. Whitaker Jr; M. D. Wadanoli

1995-01-01

182

Transition from native forest rubbers to Hevea Brasiliensis (Euphorbiaceae) among tribal smallholders in Borneo  

Microsoft Academic Search

This is a study of the historic transition in Southeast Asia, in particular Borneo, from the exploitation of native forest\\u000a rubbers to Para rubber (Hevea brasiliensis, Euphorbiaceae). During the second half of the nineteenth century, booming international markets subjected forest rubbers\\u000a to more intensive and competitive exploitation. At the same time, the settlement patterns of tribal rubber gatherers were\\u000a becoming

Michael R. Dove

1994-01-01

183

Reproductive plasticity in mole crabs, Emerita brasiliensis , in sandy beaches with contrasting morphodynamics  

Microsoft Academic Search

Ovarian macroscopical analysis, histological validation and field sampling procedures were used to evaluate the variability\\u000a in reproductive traits of the mole crab Emerita brasiliensis Schmitt, 1935 (Decapoda: Hippidae) in two exposed sandy beaches of Uruguay with contrasting morphodynamics. All developmental\\u000a stages involved in the complex life cycle exhibited lower abundance, individual size and temporal occurrence in a harsh reflective\\u000a beach,

Estela Delgado; Omar Defeo

2008-01-01

184

Variation in GUS activity in vegetatively propagated Hevea brasiliensis transgenic plants  

Microsoft Academic Search

Hevea brasiliensis transgenic plants are regenerated from transgenic callus lines by somatic embryogenesis. Somatic embryogenesis is not yet\\u000a available for commercial propagation of Hevea clones, which requires conventional grafting of buds on rootstock seedlings (budding). The stability of transgene expression\\u000a in budded plants is therefore necessary for further development of genetic engineering in rubber trees. Transgene expression\\u000a was assessed by

Ludovic Lardet; Julie Leclercq; Elise Bénistan; Florence Dessailly; Gérald Oliver; Florence Martin; Pascal Montoro

185

Crystallization of Hevamine, an Enzyme with Lysozyme\\/Chitinase Activity from Hevea brasiliensis Latex  

Microsoft Academic Search

Hevamine, an enzyme with both lysozyme and chitinase activity, was isolated and purified from Hevea brasiliensis (rubber tree) latex. The enzyme (molecular weight 29,000) is homologous to certain “pathogenesis-related” proteins from plants, but not to hen egg-white or phage T4 lysozyme. To investigate the atomic details of the substrate specificity and the cause for hevamine’s low pH optimum (pH 4.0),

Bauke W. Dijkstra; Jaap J. Beintema; Asmini Budiani; Henriëtte J. Rozeboom

1990-01-01

186

Phenotypic differences among single-oospore cultures of Phytophthora palmivora and P. botryosa from Heavea brasiliensis  

Microsoft Academic Search

Oospores ofPhytophthora palmivora andP. botryosa fromHevea brasiliensis were produced when complementary strains of the same species were incubated on V-8 juice agar in continuous darkness, with or without a subsequent period of continuous light. The oospores germinated at a rate of 15–30 % in demineralised water at 26 °C in normal daylight conditions. Other substrates did not improve the germination

K. H. Chee

1973-01-01

187

Volatile antimicrobial compounds in the pelage of the Mexican free-tailed bat, Tadarida brasiliensis mexicana  

Microsoft Academic Search

Gas chromatography–mass spectrometry (GC–MS) showed that CH2Cl2 extracts of the pelage from the Mexican free-tailed bats, Tadarida brasiliensis mexicana, contained only seven volatile compounds. They include two hydrocarbons, 1-octene and octane; three aldehydes, heptanal, octanal and nonanal; a carboxylic acid, nonanoic acid; and urea. It is likely that nonanal, at an average concentration 0.62?g\\/mg hair, and the two homologues, heptanal

William F. Wood; Joseph M. Szewczak

2007-01-01

188

Histology of early somatic embryogenesis inHevea brasiliensis: The importance of the timing of subculturing  

Microsoft Academic Search

Somatic embryos ofHevea brasiliensis can be obtained by culturing thin sections of inner tegument of seed on two successive different media, MH1 and MH3. Histological study showed that in calli cultured on non-renewed medium MH1 for 40 days, the embryogenesis process initiated on the 20th day did not produce results owing to early degeneration of the cells involved in the

Nicole Michaux-Ferrière; Marc-Philippe Carron

1989-01-01

189

Effects of carbohydrate addition on the induction of somatic embryogenesis in Hevea brasiliensis  

Microsoft Academic Search

The effect of different carbohydrates was tested on early somatic embryogenesis of Hevea brasiliensis. Sucrose was replaced with maltose, fructose or glucose. Somatic embryo production was significantly higher with maltose.\\u000a With maltose, the initial yellow colour of the calli turned orange, and dry matter production after 28 days' culture was half\\u000a that obtained with sucrose. Maltose also reduced the soluble

G. Blanc; N. Michaux-Ferrière; C. Teisson; L. Lardet; M. P. Carron

1999-01-01

190

Purification and properties of monomeric (G 1) forms of acetylcholinesterase secreted by Nippostrongylus brasiliensis  

Microsoft Academic Search

Acetylcholinesterase (AChE) activity secreted by Nippostrongylus brasiliensis was resolved by sucrose density centrifugation and gel permeation chromatography in single peaks estimated at 4.3 S and 60–85 kDa, respectively. Sedimentation was unaffected by the inclusion of detergent. AChE was purified by affinity chromatography on 9-[N?-(?-aminocaproyl)-?-aminopropylamino]-acridinium bromide hydrobromide-coupled sepharose 4B. Three forms of the enzyme (A, B and C) were distinguished by

Michael E Grigg; Liang Tang; Ayman S Hussein; Murray E Selkirk

1997-01-01

191

Virtual Yeast Cell  

NSDL National Science Digital Library

Learning about the various parts of a cell can be tricky business, but this virtual yeast cell offered by The University of Nottingham will come in handy for biology students and science instructors. This learning resource was created to help students in the brewing science program learn about yeast cytology, though just about anyone with an interest in cells will learn something from visiting the site. After entering the interactive cell, visitors can click on different parts of the cell (such as the cytoplasm or the nucleus) in order to learn more about the importance of each one. Visitors should remember that they can also download the virtual yeast cell and use it in the classroom or just with a group of friends.

192

Virtual Yeast Cell  

NSDL National Science Digital Library

Learning about the various parts of a cell can be tricky business, but this virtual yeast cell offered by The University of Nottingham will come in handy for biology students and science instructors. This learning resource was created to help students in the brewing science program learn about yeast cytology, though just about anyone with an interest in cells will learn something from visiting the site. After entering the interactive cell, visitors can click on different parts of the cell (such as the cytoplasm or the nucleus) in order to learn more about the importance of each one. Visitors should remember that they can also download the virtual yeast cell and use it in the classroom or just with a group of friends.

2008-02-28

193

Yeast killer systems.  

PubMed Central

The killer phenomenon in yeasts has been revealed to be a multicentric model for molecular biologists, virologists, phytopathologists, epidemiologists, industrial and medical microbiologists, mycologists, and pharmacologists. The surprisingly widespread occurrence of the killer phenomenon among taxonomically unrelated microorganisms, including prokaryotic and eukaryotic pathogens, has engendered a new interest in its biological significance as well as its theoretical and practical applications. The search for therapeutic opportunities by using yeast killer systems has conceptually opened new avenues for the prevention and control of life-threatening fungal diseases through the idiotypic network that is apparently exploited by the immune system in the course of natural infections. In this review, the biology, ecology, epidemiology, therapeutics, serology, and idiotypy of yeast killer systems are discussed.

Magliani, W; Conti, S; Gerloni, M; Bertolotti, D; Polonelli, L

1997-01-01

194

Ecotope effect in Triatoma brasiliensis (Hemiptera: Reduviidae) suggests phenotypic plasticity rather than adaptation.  

PubMed

Triatoma brasiliensis (Hemiptera: Reduviidae) is an important vector of Chagas' disease in both sylvatic and peridomestic ecotopes. Discriminating between these populations of Triatominae has been proposed as a means of investigating re-infestation rates of human dwellings. Geometric morphometrics have been widely applied in the study of Triatominae polymorphisms at species and population levels. This study characterizes morphometric differences between sylvatic and peridomestic populations, as well as between sexes in T. brasiliensis specimens from Jaguaruana, Ceará, in northeastern Brazil. No differences in either the shape or size of the cephalic capsule were apparent between sexes or ecotopes. However, the wings showed differentiation in shape and size. Sexual dimorphism was detected, with females presenting significantly higher values and conformations. Size differentiation was also evident, with sylvatic specimens being generally larger than peridomestic examples. These results indicate that differences in the wings of T. brasiliensis may be related to the existence of phenotypic plasticity, and variations in size and shape may be associated with different ecotopes, possibly as a result of conditions in each micro-habitat, such as temperature, relative humidity, food supply and density. PMID:22985051

Batista, V S P; Fernandes, F A; Cordeiro-Estrela, P; Sarquis, O; Lima, M M

2012-09-18

195

Trends of karyotypical evolution in the pearl cichlid, Geophagus brasiliensis, from southern Brazil.  

PubMed

Chromosomal rearrangements such as inversions can facilitate speciation even in the presence of gene flow. The present study aims to analyze the karyotypic variation in six populations of Geophagus brasiliensis from southern Brazil. All specimens showed 2n=48 chromosomes, but three karyotypes were found to have one, two or three pairs of submetacentric chromosomes. Although G. brasiliensis did not exhibit variation in the diploid number, it presented a wide interpopulational variation mainly regarding the karyotype formula and specific chromosomal markers. Differences in the location of the major and minor rDNA loci were observed among the populations. Moreover, different patterns were observed in the distribution of the constitutive heterochromatin, presenting intra- and interpopulational variation. This supports the hypothesis that this taxon represents a complex species or that cryptic species are included in this group, indicating a possibleprocess of sympatric speciation. By potentially restricting gene flow between heterokaryotypes, the segregating chromosome rearrangements we describe for G. brasiliensis may play a role in diversification in this species complex. PMID:24035646

Perazzo, Giselle X; Noleto, Rafael B; Vicari, Marcelo R; Gava, Adriana; Cestari, Marta M

2013-08-28

196

Effects of Agaricus brasiliensis mushroom in Walker-256 tumor-bearing rats.  

PubMed

Agaricus brasiliensis is a mushroom native to São Paulo State, Brazil, that is studied for its medicinal proprieties. This work aimed to investigate the antitumoral activity of A. brasiliensis extracts and pure powdered basidiocarp preparation using Walker-256 (W256) tumor-bearing rats, a model for cancer-related cachexia studies. The rats were treated for 14 days by gavage (136 mg/kg) and at the end of the experiment tumors were collected to calculate mass and volume. Blood was collected for determination of plasma glucose, albumin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Hepatic and tumor enzymes indicating oxidative stress were also evaluated. The results showed that all 4 treatments (pure powdered basidiocarp and aqueous, acid, and alkaline extracts) significantly reduced tumor size and promoted gain in body weight. Plasmatic analysis showed a reduction in AST level and increased glycemia in the treated rats. Pure basidiocarp preparations improved the liver catalase and superoxide dismutase activity, but did not change the glutathione S-transferase activity. The data collected from the W256 tumor-bearing rats revealed the beneficial effects of A. brasiliensis in tumor treatment, mainly related to cachexia. The benefits can be partly related to antioxidant activity and to reduction of weight loss and tumor growth. PMID:20130735

Jumes, Fernanda Menon Dias; Lugarini, Daiana; Pereira, Amanda Leite Bastos; de Oliveira, Anabel; Christoff, Adriana de Oliveira; Linde, Giani Andrea; do Valle, Juliana Silveira; Colauto, Nelson Barros; Acco, Alexandra

2010-01-01

197

Cytotoxic, mutagenic and antimutagenic screening of Arenosclera brasiliensis acetone and ethanol extracts.  

PubMed

The marine environment is a rich source of biologically active compounds with pharmacological properties. Marine organisms often produce secondary metabolites with structural features different from those produced by terrestrial ones, and the Phylum Porifera seems to be one of the most productive in this sense. This study was undertaken to provide data on mutagenic and antimutagenic activities from an acetone (Areac) and an ethanol (Areet) extract obtained from Arenosclera brasiliensis, an endemic Brazilian sponge. A qualitative Salmonella reverse mutation test was performed with the TA97, TA98, TA100, and TA102 strains by incubating cells with Areac and Areet in the presence and absence of a known mutagen. A cytotoxic evaluation of the extracts was also performed. A. brasiliensis did not display any mutagenic activity, but Areac showed significant toxicity against test strains. In the antimutagenic assay, a reduction in the number of his+ revertants was observed for the TA97, TA100 and TA102 strains treated with Areac when compared to the positive controls. Areet treatment showed protective activity against DNA lesions only for the TA100. These results are in agreement with those obtained previously with other A. brasiliensis extracts, suggesting an antimutagenic activity. PMID:18752179

Stankevicins, L; Aiub, C A F; Mazzei, J L; Lobo-Hajdu, G; Felzenszwalb, I

2008-06-17

198

Methods for yeast characterization from industrial products  

Microsoft Academic Search

This work compared the efficiency of four methods for the identification of industrial yeast strains and the establishment of a pattern for yeast characterization to be used during industrial fermentation processes, allowing the detection of yeast contaminants. Five strains of yeast currently used in the Brazilian fuel alcohol industry (about 99% of the yeast used for this purpose), and yeast

Luiz H Gomes; Keila M. R Duarte; Juan L Argueso; Sergio Echeverrigaray; Flavio C. A Tavares

2000-01-01

199

L-arabinose fermenting yeast  

DOEpatents

An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

Zhang, Min (Lakewood, CO); Singh, Arjun (Lakewood, CO); Knoshaug, Eric (Golden, CO); Franden, Mary Ann (Centennial, CO); Jarvis, Eric (Boulder, CO); Suominen, Pirkko (Maple Grove, MN)

2010-12-07

200

Conversion of pentoses by yeasts  

SciTech Connect

The utilization and conversion of D-xylose, D-xyulose, L-arabinose, and xylitol by yeast strains have been investigated with the following results: 1) The majority of yeasts tested utilize D-xylose and produce polyols, ethanol, and organic acids. The type and amount of products formed varies with the yeast strains used. The most commonly detected product is xylitol. 2) The majority of yeasts tested utilize D-xylulose aerobically and fermentatively to produce ethanol, xylitol D-arabitol, and organic acids. The type and amount of products varies depending upon the yeast strains used. 3) Xylitol is a poor carbon and energy source for most yeasts tested. Some yeast strains produce small amounts of ethanol from xylitol. 4) Most yeast strains utilize L-arabinose, and L-arabitol is the common product. Small amounts of ethanol are also produced by some yeast strains. 5) Of the four substrates examined, D-xylulose was the preferred substrate, followed by D-xylose, L-arabinose, and xylitol. 6) Mutant yeast strains that exhibit different metabolic product patterns can be induced and isolated from Candida sp. Saccharomyces cerevisiae, and other yeasts. These mutant strains can be used for ethanol production from D-xylose as well as for the study of metabolic regulation of pentose utilization in yeasts.

Gong, C.S.; Claypool, T.A.; Maun, C.M.; Mccracken, L.D.; Tsao, G.T.; Ueng, P.P.

1983-01-01

201

Yeasts from the North Sea  

Microsoft Academic Search

Yeasts were isolated from twelve established sites in the North Sea from 1964 to 1966. A percentage frequency of 99% with populations varying from 3000 viable cells\\/L was observed. This mycota was characterized by considerable spatial and temporal fluctuation, with the dominant yeast present being the ascosporogenous species, Debaryomyces hansenii. This taxon, as well as other common North Sea yeasts,

S. P. Meyers; D. G. Ahearn; W. Gunkel; F. J. Roth

1967-01-01

202

Evaluation of YeastIdent and Uni-Yeast-Tek yeast identification systems.  

PubMed Central

The accuracy of the new API YeastIdent system and the Flow Laboratories Uni-Yeast-Tek identification kit with an expanded data base was evaluated in comparison to the API 20C yeast identification system by three laboratories. A total of 489 test isolates were used, biased toward yeasts commonly encountered in clinical specimens. Isolates not in a system's data base were not counted in the evaluation of that system. For isolates in their data base, YeastIdent was 55% accurate and Uni-Yeast-Tek was 40% accurate. By the manufacturer's criteria of reliable identification without additional tests, both systems failed to identify many common and uncommon species. The limited number of substrates and difficulties in assessing results obtained with 11 of the API YeastIdent substrates and apparent errors in the expanded Uni-Yeast-Tek data base appeared to be major factors limiting the accuracy of these systems.

Salkin, I F; Land, G A; Hurd, N J; Goldson, P R; McGinnis, M R

1987-01-01

203

Genome evolution in yeasts  

Microsoft Academic Search

Identifying the mechanisms of eukaryotic genome evolution by comparative genomics is often complicated by the multiplicity of events that have taken place throughout the history of individual lineages, leaving only distorted and superimposed traces in the genome of each living organism. The hemiascomycete yeasts, with their compact genomes, similar lifestyle and distinct sexual and physiological properties, provide a unique opportunity

Bernard Dujon; David Sherman; Gilles Fischer; Pascal Durrens; Serge Casaregola; Ingrid Lafontaine; Jacky de Montigny; Christian Marck; Cécile Neuvéglise; Emmanuel Talla; Nicolas Goffard; Lionel Frangeul; Michel Aigle; Véronique Anthouard; Anna Babour; Valérie Barbe; Stéphanie Barnay; Sylvie Blanchin; Jean-Marie Beckerich; Emmanuelle Beyne; Claudine Bleykasten; Anita Boisramé; Jeanne Boyer; Laurence Cattolico; Fabrice Confanioleri; Antoine de Daruvar; Laurence Despons; Emmanuelle Fabre; Cécile Fairhead; Hélène Ferry-Dumazet; Alexis Groppi; Florence Hantraye; Christophe Hennequin; Nicolas Jauniaux; Philippe Joyet; Rym Kachouri; Alix Kerrest; Romain Koszul; Marc Lemaire; Isabelle Lesur; Laurence Ma; Héloïse Muller; Jean-Marc Nicaud; Macha Nikolski; Sophie Oztas; Odile Ozier-Kalogeropoulos; Stefan Pellenz; Serge Potier; Guy-Franck Richard; Marie-Laure Straub; Audrey Suleau; Dominique Swennen; Fredj Tekaia; Micheline Wésolowski-Louvel; Eric Westhof; Bénédicte Wirth; Maria Zeniou-Meyer; Ivan Zivanovic; Monique Bolotin-Fukuhara; Agnès Thierry; Christiane Bouchier; Bernard Caudron; Claude Scarpelli; Claude Gaillardin; Jean Weissenbach; Patrick Wincker; Jean-Luc Souciet

2004-01-01

204

Biosynthesis of yeast mitochondria  

Microsoft Academic Search

Ethidium bromide selectively inhibits growth of the petite negative yeast Kluyveromyces fragilis on a non-fermentable carbon source. In short term experiments, when growth in ethidium is continued for about 11 generations, this inhibition is accompanied by a loss of cyanide sensitive respiration and particulate cytochromes, an initial phase of microcolony production, and an inhibition of mitochondrial DNA synthesis. The loss

A. A. Luha; P. A. Whittaker; R. C. Hammond

1974-01-01

205

Yeast DNA Extraction  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can easily be extracted from yeast using simple materials. Use this experiment to supplement any unit on genetics and to demonstrate how scientists study DNA. Adult supervision is recommended. This resource guide includes tips and suggestions for instructors as well as other DNA extraction experiments and a chart for learners to answer questions.

Hays, Lana

2009-01-01

206

Epidemiological and biological aspects on Ornithodoros brasiliensis (mouro tick), an argasidae tick only found on the highlands region of Rio Grande do Sul state, southern Brazil  

Technology Transfer Automated Retrieval System (TEKTRAN)

The soft tick Ornithodoros brasiliensis (Acari: Argasidae) is present in farms along the highlands of Rio Grande do Sul state in southern Brazil. Reports of human parasitism by O. brasiliensis drew the attention of local health authorities. A preliminary epidemiological survey was conducted to ident...

207

Kidney Function Indices in Mice after Long Intake of Agaricus brasiliensis Mycelia (=Agaricus blazei, Agaricus subrufescens) Produced by Solid State Cultivation  

Microsoft Academic Search

Problem statement: Agaricus brasiliensis (= Agaricus blazei , Agaricus subrufescens ) or Sun mushroom has widespread use for potential health benefits such anti-tumor and immunomodulatory effects. Studies detected that others edible mushrooms affected renal metabolism and despite the widespread use of A. brasiliensis there are no studies that address biological effec ts on the renal function indices after their oral

Rubel; Herta Stutz; Rubel Rosália; Leifa Fan

2009-01-01

208

Tumor necrosis factor and macrophage activation are important in clearance of Nocardia brasiliensis from the livers and spleens of mice.  

PubMed Central

The roles of tumor necrosis factor (TNF) and macrophage activation in clearance of Nocardia brasiliensis from BALB/c mouse livers and spleens were evaluated. TNF activity was detectable in sera from animals at all stages of infection. Treatment of infected mice with an antiserum against TNF significantly enhanced the experimental infection as judged by enumeration of CFU in the spleens and livers of infected mice. In another set of experiments, a population of activated macrophages from the peritoneal cavities of N. brasiliensis-infected mice was studied by using a cytostatic assay. The observed cytotoxic activity of these activated macrophages against L929 cells was mediated by TNF, since this activity was inhibited by anti-TNF antiserum treatment. The level of TNF activity generated in vitro in the presence of lipopolysaccharide (LPS) by peritoneal macrophages from infected mice was higher than that of adherent peritoneal cells obtained from normal mice after challenge with LPS. When the nocardiacidal activity of peritoneal cells from N. brasiliensis-infected mice was estimated in vitro, a significant decrease in the number of CFU recovered was observed. Moreover, nocardiacidal activity of peritoneal cells obtained from N. brasiliensis-infected mice previously treated with anti-TNF antiserum was significantly reduced compared with the activity of cells obtained from infected mice previously treated with normal rabbit serum and that of cells from uninfected mice. These data suggest a role for TNF in resistance to N. brasiliensis infection.

Silva, C L; Faccioli, L H

1992-01-01

209

L-arabinose fermenting yeast  

DOEpatents

An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

2013-02-12

210

Differences in Cell Morphometry, Cell Wall Topography and Gp70 Expression Correlate with the Virulence of Sporothrix brasiliensis Clinical Isolates.  

PubMed

Sporotrichosis is a chronic infectious disease affecting both humans and animals. For many years, this subcutaneous mycosis had been attributed to a single etiological agent; however, it is now known that this taxon consists of a complex of at least four pathogenic species, including Sporothrix schenckii and Sporothrix brasiliensis. Gp70 was previously shown to be an important antigen and adhesin expressed on the fungal cell surface and may have a key role in immunomodulation and host response. The aim of this work was to study the virulence, morphometry, cell surface topology and gp70 expression of clinical isolates of S. brasiliensis compared with two reference strains of S. schenckii. Several clinical isolates related to severe human cases or associated with the Brazilian zoonotic outbreak of sporotrichosis were genotyped and clustered as S. brasiliensis. Interestingly, in a murine subcutaneous model of sporotrichosis, these isolates showed a higher virulence profile compared with S. schenckii. A single S. brasiliensis isolate from an HIV-positive patient not only showed lower virulence but also presented differences in cell morphometry, cell wall topography and abundant gp70 expression compared with the virulent isolates. In contrast, the highly virulent S. brasiliensis isolates showed reduced levels of cell wall gp70. These observations were confirmed by the topographical location of the gp70 antigen using immunoelectromicroscopy in both species. In addition, the gp70 molecule was sequenced and identified using mass spectrometry, and the sequenced peptides were aligned into predicted proteins using Blastp with the S. schenckii and S. brasiliensis genomes. PMID:24116065

Castro, Rafaela A; Kubitschek-Barreira, Paula H; Teixeira, Pedro A C; Sanches, Glenda F; Teixeira, Marcus M; Quintella, Leonardo P; Almeida, Sandro R; Costa, Rosane O; Camargo, Zoilo P; Felipe, Maria S S; de Souza, Wanderley; Lopes-Bezerra, Leila M

2013-10-07

211

Mammalian Homology to Yeast  

NSDL National Science Digital Library

This site allows researchers to retrieve a yeast-against-mammal Basic Local Alignment Search Tool (BLAST) report by entering a gene or ORF name into a search function. The supporting data were first summarized in a recent Science article which is provided via a link to the journal (Science, 22 July 1997; Issue 277: p.1259). Steve Chervitz of Stanford University maintains this site.

1997-01-01

212

''Is Yeast Alive?''  

NSDL National Science Digital Library

In this inquiry activity students explore the characteristics of living organisms to determine whether yeast meets the criteria of a living thing. This inquiry activity was developed by a K-12 science teacher in the American Physiological SocietyÃÂs 2006 Frontiers in Physiology Program. The NSES Standards addressed by this activity are current as of the year of development. For more information on the Frontiers in Physiology Program, please visit www.frontiersinphys.org.

Ms. Katrenia Hosea-Flanigan (Frank Cody High School)

2006-04-01

213

Chemical transformation of yeast.  

PubMed

Transformation of chemically competent yeast cells is a method for introducing exogenous DNA into living cells. Typically, the DNA is either a plasmid carrying an autonomous replication sequence that allows for propagation or a linear piece of DNA to be integrated into the genome. The DNA usually also carries a marker that allows for selection of successfully transformed cells by plating on the appropriate selective media. PMID:24011057

Bergkessel, Megan; Guthrie, Christine

2013-01-01

214

Glutathione Production in Yeast  

NASA Astrophysics Data System (ADS)

Glutathione, ? -glutamyl-cysteinyl-glycine, is the most abundant non-protein thiol found in almost all eukaryotic cells (and in some prokaryotes). The tripeptide, which is synthesized non-ribosomally by the consecutive action of two soluble enzymes, is needed for carrying out numerous functions in the cell, most important of which is the maintenance of the redox buffer. The cycle of glutathione biosynthesis and degradation forms part of the ? -glutamyl cycle in most organisms although the latter half of the pathway has not been demonstrated in yeasts. Our current understanding of how glutathione levels are controlled at different levels in the cell is described. Several different routes and processes have been attempted to increase commercial production of glutathione using both yeast and bacteria. In this article we discuss the history of glutathione production in yeast. The current bottlenecks for increased glutathione production are presented based on our current understanding of the regulation of glutathione homeostasis, and possible strategies for overcoming these limitations for further enhancing and improving glutathione production are discussed

Bachhawat, Anand K.; Ganguli, Dwaipayan; Kaur, Jaspreet; Kasturia, Neha; Thakur, Anil; Kaur, Hardeep; Kumar, Akhilesh; Yadav, Amit

215

A Cross-Reactive Monoclonal Antibody to Nematode Haemoglobin Enhances Protective Immune Responses to Nippostrongylus brasiliensis  

PubMed Central

Background Nematode secreted haemoglobins have unusually high affinity for oxygen and possess nitric oxide deoxygenase, and catalase activity thought to be important in protection against host immune responses to infection. In this study, we generated a monoclonal antibody (48Eg) against haemoglobin of the nematode Anisakis pegreffii, and aimed to characterize cross-reactivity of 4E8g against haemoglobins of different nematodes and its potential to mediate protective immunity against a murine hookworm infection. Methodology/Principal Findings Immunoprecipitation was used to isolate the 4E8g-binding antigen in Anisakis and Ascaris extracts, which were identified as haemoglobins by peptide mass fingerprinting and MS/MS. Immunological cross-reactivity was also demonstrated with haemoglobin of the rodent hookworm N. brasiliensis. Immunogenicity of nematode haemoglobin in mice and humans was tested by immunoblotting. Anisakis haemoglobin was recognized by IgG and IgE antibodies of Anisakis-infected mice, while Ascaris haemoglobin was recognized by IgG but not IgE antibodies in mouse and human sera. Sequencing of Anisakis haemoglobin revealed high similarity to haemoglobin of a related marine nematode, Psuedoterranova decipiens, which lacks the four –HKEE repeats of Ascaris haemoglobin important in octamer assembly. The localization of haemoglobin in the different parasites was examined by immunohistochemistry and associated with the excretory-secretary ducts in Anisakis, Ascaris and N. brasiliensis. Anisakis haemoglobin was strongly expressed in the L3 stage, unlike Ascaris haemoglobin, which is reportedly mainly expressed in adult worms. Passive immunization of mice with 4E8g prior to infection with N. brasiliensis enhanced protective Th2 immunity and led to a significant decrease in worm burdens. Conclusion The monoclonal antibody 4E8g targets haemoglobin in broadly equivalent anatomical locations in parasitic nematodes and enhances host immunity to a hookworm infection.

Nieuwenhuizen, Natalie E.; Meter, Jeanne M.; Horsnell, William G.; Hoving, J. Claire; Fick, Lizette; Sharp, Michael F.; Darby, Matthew G.; Parihar, Suraj P.; Brombacher, Frank; Lopata, Andreas L.

2013-01-01

216

C-type lectins from the nematode parasites Heligmosomoides polygyrus and Nippostrongylus brasiliensis  

PubMed Central

The C-type lectin superfamily is highly represented in all metazoan phyla so far studied. Many members of this superfamily are important in innate immune defences against infection, while others serve key developmental and structural roles. Within the superfamily, many proteins contain multiple canonical carbohydrate-recognition domains (CRDs), together with additional non-lectin domains. In this report, we have studied two gastrointestinal nematode parasites which are widely used in experimental rodent systems, Heligmosomoides polygyrus and Nippostrongylus brasiliensis. From cDNA libraries, we have isolated 3 new C-type lectins from these species; all are single-CRD proteins with short additional N-terminal domains. The predicted Hp-CTL-1 protein contains 156 aa, Nb-CTL-1 191 aa and Nb-CTL-2 183 aa; all encode predicted signal peptides, as well as key conserved sequence motifs characteristic of the CTL superfamily. These lectins are most similar to C. elegans CLEC-48, 49 and 50, as well as to the lectin domains of mammalian immune system proteins CD23 and CD206. RT-PCR showed that these H. polygyrus and N. brasiliensis genes are primarily expressed in the gut-dwelling adult stages, although Nb-CTL-2 transcripts are also prominent in the free-living infective larval (L3) stage. Polyclonal antibodies raised to Hp-CTL-1 and Nb-CTL-1 reacted to both proteins by ELISA, and in Western blot analysis recognised a 15-kDa band in secreted proteins of adult N. brasiliensis (NES) and a 19-kDa band in H. polygyrus ES (HES). Anti-CTL-1 antibody also bound strongly to the cuticle of adult H. polygyrus. Hence, live parasites release C-type lectins homologous to some key receptors of the mammalian host immune system, raising the possibility that these products interfere in some manner with immunological recognition or effector function.

Harcus, Yvonne; Nicoll, Gavin; Murray, Janice; Filbey, Kara; Gomez-Escobar, Natalia; Maizels, Rick M

2009-01-01

217

Identification of T-cell reactive antigens in Nippostrongylus brasiliensis using a cell immunoblotting technique.  

PubMed

Antigens of the nematode Nippostrongylus brasiliensis were fractionated by SDS-PAGE under reducing conditions, transferred electrophoretically onto nitrocellulose and converted to antigen-bound nitrocellulose particles for use in in vitro proliferation assays. Mesenteric lymph node cells from infected rats were analyzed for reactivity against the fractionated antigens, revealing a range of different molecular weight antigens. In addition, when supernatants from these cultures were assayed for IL3, further reactive antigens were detected. The results demonstrated that these approaches are useful for the identification of T-cell reactive components of a complex mixture of parasite antigens in helminth infections, where the cellular nature of protection is not well defined. PMID:2101075

Giorgio, S; Haig, D M

1990-01-01

218

Conservation of yeasts by dehydration  

Microsoft Academic Search

The presented material concerns the theoretical basis for obtaining high-quality active dry biopreparations. It deals with the present understanding of anabiosis, contains data on yeast resistance against dehydration and the limits for preserving the viability of microorganisms in anabiosis. The process of water transport in yeast biomass during dehydration is discussed.\\u000a The changes and transformations in yeast cells occuring after

Martin Beker; Alexander Rapoport

219

Yeast interactions and wine flavour.  

PubMed

Wine is the product of complex interactions between fungi, yeasts and bacteria that commence in the vineyard and continue throughout the fermentation process until packaging. Although grape cultivar and cultivation provide the foundations of wine flavour, microorganisms, especially yeasts, impact on the subtlety and individuality of the flavour response. Consequently, it is important to identify and understand the ecological interactions that occur between the different microbial groups, species and strains. These interactions encompass yeast-yeast, yeast-filamentous fungi and yeast-bacteria responses. The surface of healthy grapes has a predominance of Aureobasidium pullulans, Metschnikowia, Hanseniaspora (Kloeckera), Cryptococcus and Rhodotorula species depending on stage of maturity. This microflora moderates the growth of spoilage and mycotoxigenic fungi on grapes, the species and strains of yeasts that contribute to alcoholic fermentation, and the bacteria that contribute to malolactic fermentation. Damaged grapes have increased populations of lactic and acetic acid bacteria that impact on yeasts during alcoholic fermentation. Alcoholic fermentation is characterised by the successional growth of various yeast species and strains, where yeast-yeast interactions determine the ecology. Through yeast-bacterial interactions, this ecology can determine progression of the malolactic fermentation, and potential growth of spoilage bacteria in the final product. The mechanisms by which one species/strain impacts on another in grape-wine ecosystems include: production of lytic enzymes, ethanol, sulphur dioxide and killer toxin/bacteriocin like peptides; nutrient depletion including removal of oxygen, and production of carbon dioxide; and release of cell autolytic components. Cell-cell communication through quorum sensing molecules needs investigation. PMID:12892919

Fleet, Graham H

2003-09-01

220

Production of food yeast from starchy substrates  

Microsoft Academic Search

Fifteen yeast strains were selected for the production of food yeast from starchy substrates. From comparison with the amylolytic yeasts, a strain of Schwanniomyces castellii was selected and its characteristics are described.

A. Touzi; J. P. Prebois; G. Moulin; F. Deschamps; P. Galzy

1982-01-01

221

21 CFR 172.896 - Dried yeasts.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 2009-04-01 false Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

2009-04-01

222

21 CFR 172.896 - Dried yeasts.  

Code of Federal Regulations, 2010 CFR

...3 2010-01-01 2009-04-01 true Dried yeasts. 172.896 Section 172.896 Food and Drugs...CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces...

2010-01-01

223

21 CFR 172.896 - Dried yeasts.  

Code of Federal Regulations, 2013 CFR

...FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis ) and dried torula yeast (Candida utilis ) may be safely used in food provided the...

2013-04-01

224

21 CFR 73.355 - Phaffia yeast.  

Code of Federal Regulations, 2013 CFR

...CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of the yeast Phaffia rhodozyma. (2) Phaffia...

2013-04-01

225

21 CFR 73.355 - Phaffia yeast.  

Code of Federal Regulations, 2010 CFR

...CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of the yeast Phaffia rhodozyma. (2) Phaffia...

2010-04-01

226

21 CFR 73.355 - Phaffia yeast.  

Code of Federal Regulations, 2010 CFR

...CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of the yeast Phaffia rhodozyma. (2) Phaffia...

2009-04-01

227

Antimicrobial activity of Rheedia brasiliensis and 7-epiclusianone against Streptococcus mutans.  

PubMed

This in vitro study evaluated the antimicrobial activity of extracts obtained from Rheedia brasiliensis fruit (bacupari) and its bioactive compound against Streptococcus mutans. Hexane, ethyl-acetate and ethanolic extracts obtained (concentrations ranging from 6.25 to 800 microg/ml) were tested against S. mutans UA159 through MIC/MBC assays. S. mutans 5-days-old biofilms were treated with the active extracts (100 x MIC) for 0, 1, 2, 3 and 4h (time-kill) and plated for colony counting (CFU/ml). Active extracts were submitted to exploratory chemical analyses so as to isolate and identify the bioactive compound using spectroscopic methods. The bioactive compound (concentrations ranging from 0.625 to 80 microg/ml) was then tested through MIC/MBC assays. Peel and seed hexane extracts showed antimicrobial activity against planktonic cells at low concentrations and were thus selected for the time kill test. These hexane extracts reduced S. mutans biofilm viability after 4h, certifying of the bioactive compound presence. The bioactive compound identified was the polyprenylated benzophenone 7-epiclusianone, which showed a good antimicrobial activity at low concentrations (MIC: 1.25-2.5 microg/ml; MBC: 10-20 microg/ml). The results indicated that 7-epiclusianone may be used as a new agent to control S. mutans biofilms; however, more studies are needed to further elucidate the mechanisms of action and the anticariogenic potential of such compound found in R. brasiliensis. PMID:18276126

Almeida, L S B; Murata, R M; Yatsuda, R; Dos Santos, M H; Nagem, T J; Alencar, S M; Koo, H; Rosalen, P L

2008-02-13

228

Use of L4 larvae of Nippostrongylus brasiliensis for the in vivo screening of anthelmintic drugs.  

PubMed Central

Five groups of Wistar rats were subcutaneously infected with 5,000 L3 stage larvae of Nippostrongylus brasiliensis. Four groups were dosed orally with 5, 10, 15, and 20 mg/kg body weight of albendazole at 5 h postinfection, and one group served as an untreated control. The animals were euthanized and the intestines were dissected out 72 h postinfection and were incubated on a Baermann's apparatus to recover L4 stage larvae. No larvae were recovered from the 20 mg/kg albendazole-treated group, and means of 15, 33, and 175 L4 larvae were recovered from the 15, 10, and 5 mg/kg albendazole-treated groups, respectively. Levamisole and fenbendazole were also tested using the same procedure. Means of 100 and 1,887 L4 larvae were obtained from the 50 and 10 mg/kg of levamisole-treated groups respectively; while, 191 and 583 L4 larvae were recovered from rats treated with 50 and 10 mg/kg of fenbendazole, respectively. These results indicate that the L4 stage of N. brasiliensis could be useful for in vivo screening of new nematocide drugs.

Dominguez, L; Saldana, J; Chernin, J

2000-01-01

229

Chemically-Mediated Roostmate Recognition and Roost Selection by Brazilian Free-Tailed Bats (Tadarida brasiliensis)  

PubMed Central

Background The Brazilian free-tailed bat (Tadarida brasiliensis) is an exceptionally social and gregarious species of chiropteran known to roost in assemblages that can number in the millions. Chemical recognition of roostmates within these assemblages has not been extensively studied despite the fact that an ability to chemically recognize individuals could play an important role in forming and stabilizing complex suites of social interactions. Methodology/Principal Findings Individual bats were given a choice between three roosting pouches: one permeated with the scent of a group of roostmates, one permeated with the scent of non-roostmates, and a clean control. Subjects rejected non-roostmate pouches with greater frequency than roostmate pouches or blank control pouches. Also, bats chose to roost in the roostmate scented pouches more often than the non-roostmate or control pouches. Conclusions/Significance We demonstrated that T. brasiliensis has the ability to chemically recognize roostmates from non-roostmates and a preference for roosting in areas occupied by roostmates. It is important to investigate these behaviors because of their potential importance in colony dynamics and roost choice.

Englert, Amy C.; Greene, Michael J.

2009-01-01

230

Green synthesis of colloidal silver nanoparticles using natural rubber latex extracted from Hevea brasiliensis  

NASA Astrophysics Data System (ADS)

Colloidal silver nanoparticles were synthesized by an easy green method using thermal treatment of aqueous solutions of silver nitrate and natural rubber latex (NRL) extracted from Hevea brasiliensis. The UV-Vis spectra detected the characteristic surface plasmonic absorption band around 435 nm. Both NRL and AgNO 3 contents in the reaction medium have influence in the Ag nanoparticles formation. Lower AgNO 3 concentration led to decreased particle size. The silver nanoparticles presented diameters ranging from 2 nm to 100 nm and had spherical shape. The selected area electron diffraction (SAED) patterns indicated that the silver nanoparticles have face centered cubic (fcc) crystalline structure. FTIR spectra suggest that reduction of the silver ions are facilitated by their interaction with the amine groups from ammonia, which is used for conservation of the NRL, whereas the stability of the particles results from cis-isoprene binding onto the surface of nanoparticles. Therefore natural rubber latex extracted from H. brasiliensis can be employed in the preparation of stable aqueous dispersions of silver nanoparticles acting as a dispersing and/or capping agent. Moreover, this work provides a new method for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive.

Guidelli, Eder José; Ramos, Ana Paula; Zaniquelli, Maria Elisabete D.; Baffa, Oswaldo

2011-11-01

231

Genotoxic and antigenotoxic evaluation of extracts from Arenosclera brasiliensis, a Brazilian marine sponge.  

PubMed

The marine environment is a rich source of biological active compounds and the sponges can be considered the most productive one. This diversity gives rise to unique chemical compounds with potential pharmacological properties. Our study is focused on the genotoxic and antigenotoxic evaluation of two crude extracts obtained from the Brazilian endemic marine sponge Arenosclera brasiliensis. Salmonella typhimurium reverse mutation test with TA97, TA98, TA100 and TA102 strains were performed. For antimutagenic analysis, a pre-, co-, and post-treatment to evaluate, respectively, intracellular and extracellular reactions and possible modulation on DNA repair. Additionally, in order to verify the influence of the crude extracts on DNA damage induction, a plasmid-DNA treatment was assayed. No mutagenicity was observed in Salmonella reverse mutation test, neither DNA strand induced damage. Antimutagenic activity was observed in pre-, co-, and post-treatment. A significant antigenotoxic effect was observed in the crude extract, which suggests that A. brasiliensis extract has the potential to protect DNA from the action of 4NQO, 2-aminofluorene, sodium azide and mitomycin C. PMID:18835431

Stankevicins, L; Aiub, C; Maria, L C de Santa; Lobo-Hajdu, G; Felzenszwalb, I

2008-09-16

232

[Development and application of EST-SSR markers in Hevea brasiliensis Muell. Arg].  

PubMed

Three thousand and ninety Unigenes were obtained from 10 778 Hevea brasiliensis ESTs. Four hundred and thirty SSRs were distributed in 353 Unigenes, which accounts for 11.42% of the total number of Unigenes. The frequency of SSRs was 1/3.93 kb. Dinucleotide and trinucleotide repeats were the dominant types among the obtained unigenes, accounting for 63.49% and 32.09%, respectively. TC/AG, CT/GA and CTT/GAA, AAG/TTC, and AGA/TCT were the most abundant motifs for dinucleotide and trinucleotide motifs. One hundred and forty-eight primer pairs were designed by PRIMER5.0 and 21 primer pairs were synthesized. Among them, 15 primer pairs can produce clear and stable bands, and the PCR products were screened in denaturing polyacrylamide gel following silver staining. Genetic diversity of 44 rubber clones were investigated with these primer pairs, and a dendrogram of 44 rubber clones was built. The results indicated that it is an effective and feasible way to develop EST-SSR markers from H. brasiliensis EST sequences, and the primers designed in this study can be used in genetic study of rubber tree. PMID:19273446

An, Ze-Wei; Zhao, Yan-Hong; Cheng, Han

2009-03-01

233

Antibacterial activity against resistant bacteria and cytotoxicity of four alkaloid toxins isolated from the marine sponge Arenosclera brasiliensis  

Microsoft Academic Search

Arenosclerins A–C and haliclonacyclamine E, new tetracyclic alkylpiperidine alkaloids isolated from the marine sponge Arenosclera brasiliensis, were subjected to antimicrobial and cytotoxic bioassays. Fourteen samples of microorganisms were used: Candida albicans, Staphylococcus aureus, Escherichia coli, and 12 antibiotic-resistant bacteria isolated from hospital environment. The minimum inhibitory concentration activity of each alkaloid was determined. The four compounds displayed antibacterial activity, but

Yohandra R Torres; Roberto G. S Berlinck; Gislene G. F Nascimento; Sérgio C Fortier; Claudia Pessoa; Manoel O de Moraes

2002-01-01

234

Consumption rate, food preferences and transit time of captive giant otters Pteronura brasiliensis: Implications for the study of wild populations  

Microsoft Academic Search

Food consumption, food preferences and transit time of digesta were determined in captive giant otters, Pteronura brasiliensis, at the National Institute of Amazon Research (INPA), Manaus, Brazil. Food consumption of an adult female was 0.0997 kg1 day1. Giant otters showed sig- nificant and varied preferences for the single Siluriformes (catfish) and various Characiformes species offered. The adult female preferred Anostomidae

Sarah K. Carter; Fernando C. W. Rosas; Andrew B. Cooper; A. C. Cordeiro-Duarte

235

Precipitation of Hevea brasiliensis Latex Proteins with Trichloroacetic Acid and Phosphotungstic Acid in Preparation for the Lowry Protein Assay  

Microsoft Academic Search

Many proteins derived from the latex of Hevea brasiliensis that remain soluble in trichloroacetic acid (TCA) can be precipitated by phosphotungstic acid (PTA). A combination of 5% TCA and 0.2% PTA precipitates a wide range of proteins effectively even when they are present in low concentrations (below 1 ?g ml?1). In addition to its protein purification function, acid precipitation also

H. Y. Yeang; F. Yusof; L. Abdullah

1995-01-01

236

Analysis of genetic diversity in early introduced clones of rubber tree (Hevea brasiliensis) using RAPD and microsatellite markers  

Microsoft Academic Search

Genetic analysis in 53 early introduced clones of rubber tree (Hevea brasiliensis) collected from different areas in Southern Thailand was performed using RAPD (Random Amplified Polymorphic DNA) and microsatellite markers. Seven- teen cultivated clones (34 samples) were also included to compare DNA patterns. DNA was isolated from leaf samples using CTAB buffer. One hundred and ninety two 10-base oligonucleotide primers

Korakot Nakkanong; Charassri Nualsri; Sayan Sdoodee

2008-01-01

237

Habitat use by Myotis yumanensis and Tadarida brasiliensis mexicana in South San Francisco Bay wetlands: An Acoustic Study  

Microsoft Academic Search

Research on bat habitat use within coastal estuaries is limited. The purposes of my study were to determine whether Yuma myotis (Myotis yumanensis) and Mexican free-tailed bats (Tadarida brasiliensis mexicana) differentiate between open water and marsh within saline and brackish habitats and to examine whether climatic factors are correlated with general activity and tidal height with foraging of the two

Theresa Brickley

2012-01-01

238

EVIDENCE FOR PRENATAL TRANSFER OF RABIES VIRUS IN THE MEXICAN FREE-TAILED BAT (TADARIDA BRASILIENSIS MEXICANA)  

Microsoft Academic Search

Fetuses were collected from four Mexican free-tailed bats (Tadarida brasiliensis niexicana) and a fetal bat cell (FBC) line was established and tested for its ability to support the replication of the ERA vaccine strain of rabies virus. Cytopathic effects were detected in ERA virus-inoculated as well as uninoculated FBC's. Immunoflorescent antibody testing of uninoculated FBC's provided no evidence for the

Richard S. Steece; Charles H. Calisher

239

Cellular IgE Response of Rodents to Infection with Nippostrongylus brasiliensis, Trichinella spiralis and Schistosoma mansoni.  

National Technical Information Service (NTIS)

Inoculation of mice with infective larvae of the nematodes N. brasiliensis or T. spiralis and inoculation of rats with N. brasilienisis results in changes in the mesenteric lymph nodes draining the site of infection, that include a peak 3-4 fold increase ...

J. F. Urban I.M. Katona D. A. Dean F. D. Finkelman

1984-01-01

240

Effect of Agaricus brasiliensis-derived cold water extract on Toll-like receptor 2-dependent cytokine production in vitro.  

PubMed

Agaricus brasiliensis (Agaricus blazei Murrill) is well known as a medicinal mushroom. Fruit body of A. brasiliensis is rich in ?-glucan and has shown benefits for various diseases. Both hot and cold water extraction are traditional methods for intake of this mushroom extract. In the present study, we prepared cold water extract of the fruit body of A. brasiliensis (ACWS). The 1,3-?-glucan segment of this fraction was too small and did not interact with the 1,3-?-glucan receptor, dectin-1. However, ACWS could induce production of various cytokines including IL-6 from murine splenocytes. Therefore, we aimed to identify the receptor that modulates IL-6 production using ACWS. We focused our attention on Toll-like receptors (TLRs) and examined them as follows. (i) The interaction between TLRs and ACWS was screened using HEK293 cells transfected with TLR plasmid. (ii) IL-6 production from splenocytes induced by ACWS was inhibited by treatment of anti-TLR antibodies. (iii) Direct binding activity between TLR protein and ACWS was assessed by ELISA-like assay. ACWS was found to activate HEK293 cells via TLR2, 4 and 5. However, only anti-TLR2 monoclonal antibody suppressed IL-6 production from splenocytes. In addition, ACWS has the ability to bind directly to TLR2 protein. Accordingly, we suggest that fruit body of A. brasiliensis has some water-soluble TLR ligand complexes, and TLR2 on splenocytes strongly induces IL-6 production. PMID:22126586

Yamanaka, Daisuke; Motoi, Masuro; Ishibashi, Ken-ichi; Miura, Noriko N; Adachi, Yoshiyuki; Ohno, Naohito

2011-11-29

241

Yeasts: From genetics to biotechnology  

Microsoft Academic Search

Yeasts have been known and used in food and alcoholic fermentations ever since the Neolithic Age. In more recent times, on the basis of their peculiar features and history, yeasts have become very important experimental models in both microbiological and genetic research, as well as the main characters in many fermentative production processes. In the last 40 years, advances in

S. Russo; G. Poli; R. B. Siman-Tov

1995-01-01

242

A numericlature of the Yeasts  

Microsoft Academic Search

A numericlature, based on a descriptive numerical code has been compiled for the yeasts. A total of 429 yeast species are represented by 388 unique four-, six- or seven-digit numbers and of these 364 correspond to single species. It is suggested that the coding method is a valid alternative to binomial nomenclature based on a conventional hierarchical classification. It can

A. J. Griffiths

1981-01-01

243

Growth of Solar Radiated Yeast.  

National Technical Information Service (NTIS)

This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddar...

T. Kraft

1995-01-01

244

The intronome of budding yeasts  

Microsoft Academic Search

Whatever their abundance in genomes, spliceosomal introns are the signature of eukaryotic genes. The sequence of Saccharomyces cerevisiae, achieved fifteen years ago, revealed that this yeast has very few introns, but conserved intron boundaries typical for an intron definition mechanism. With the improvement and the development of new sequencing technologies, yeast genomes have been extensively sequenced during the last decade. We

Cécile Neuvéglise; Christian Marck; Claude Gaillardin

2011-01-01

245

Apoptotic death of ageing yeast  

Microsoft Academic Search

Yeast has been a valuable model to study replicative and chronological ageing processes. Replicative ageing is defined by the number of daughter cells a mother can give birth to and hence reflects the ageing situation in proliferating cells, whereas chronological ageing is widely accepted as a model for postmitotic tissue ageing. Since both ageing forms end in yeast programmed death

Patrick Rockenfeller; Frank Madeo

2008-01-01

246

The Budding Yeast Nucleus  

PubMed Central

The budding yeast nucleus, like those of other eukaryotic species, is highly organized with respect to both chromosomal sequences and enzymatic activities. At the nuclear periphery interactions of nuclear pores with chromatin, mRNA, and transport factors promote efficient gene expression, whereas centromeres, telomeres, and silent chromatin are clustered and anchored away from pores. Internal nuclear organization appears to be function-dependent, reflecting localized sites for tRNA transcription, rDNA transcription, ribosome assembly, and DNA repair. Recent advances have identified new proteins involved in the positioning of chromatin and have allowed testing of the functional role of higher-order chromatin organization. The unequal distribution of silent information regulatory factors and histone modifying enzymes, which arises in part from the juxtaposition of telomeric repeats, has been shown to influence chromatin-mediated transcriptional repression. Other localization events suppress unwanted recombination. These findings highlight the contribution budding yeast genetics and cytology have made to dissecting the functional role of nuclear structure.

Taddei, Angela; Schober, Heiko; Gasser, Susan M.

2010-01-01

247

Stress signaling in yeast.  

PubMed

In the yeast Saccharomyces cerevisiae three positive transcriptional control elements are activated by stress conditions: heat shock elements (HSEs), stress response elements (STREs) and AP-1 responsive elements (AREs). HSEs bind heat shock transcription factor (HSF), which is activated by stress conditions causing accumulation of abnormal proteins. STREs mediate transcriptional activation by multiple stress conditions. They are controlled by high osmolarity via the HOG signal pathway, which comprises a MAP kinase module and a two-component system homologous to prokaryotic signal transducers. AREs bind the transcription factor Yap1p. The three types of control elements seem to have overlapping, but distinct functions. Some stress proteins encoded by HSE-regulated genes are necessary for growth of yeast under moderate stress, products of STRE-activated genes appear to be important for survival under severe stress and ARE-controlled genes may mainly function during oxidative stress and in the response to toxic conditions, such as caused by heavy metal ions. PMID:8526890

Ruis, H; Schüller, C

1995-11-01

248

Transcriptome Sequencing of Hevea brasiliensis for Development of Microsatellite Markers and Construction of a Genetic Linkage Map  

PubMed Central

To obtain more information on the Hevea brasiliensis genome, we sequenced the transcriptome from the vegetative shoot apex yielding 2 311 497 reads. Clustering and assembly of the reads produced a total of 113 313 unique sequences, comprising 28 387 isotigs and 84 926 singletons. Also, 17 819 expressed sequence tag (EST)-simple sequence repeats (SSRs) were identified from the data set. To demonstrate the use of this EST resource for marker development, primers were designed for 430 of the EST-SSRs. Three hundred and twenty-three primer pairs were amplifiable in H. brasiliensis clones. Polymorphic information content values of selected 47 SSRs among 20 H. brasiliensis clones ranged from 0.13 to 0.71, with an average of 0.51. A dendrogram of genetic similarities between the 20 H. brasiliensis clones using these 47 EST-SSRs suggested two distinct groups that correlated well with clone pedigree. These novel EST-SSRs together with the published SSRs were used for the construction of an integrated parental linkage map of H. brasiliensis based on 81 lines of an F1 mapping population. The map consisted of 97 loci, consisting of 37 novel EST-SSRs and 60 published SSRs, distributed on 23 linkage groups and covered 842.9 cM with a mean interval of 11.9 cM and ?4 loci per linkage group. Although the numbers of linkage groups exceed the haploid number (18), but with several common markers between homologous linkage groups with the previous map indicated that the F1 map in this study is appropriate for further study in marker-assisted selection.

Triwitayakorn, Kanokporn; Chatkulkawin, Pornsupa; Kanjanawattanawong, Supanath; Sraphet, Supajit; Yoocha, Thippawan; Sangsrakru, Duangjai; Chanprasert, Juntima; Ngamphiw, Chumpol; Jomchai, Nukoon; Therawattanasuk, Kanikar; Tangphatsornruang, Sithichoke

2011-01-01

249

Yeasts: From genetics to biotechnology  

SciTech Connect

Yeasts have been known and used in food and alcoholic fermentations ever since the Neolithic Age. In more recent times, on the basis of their peculiar features and history, yeasts have become very important experimental models in both microbiological and genetic research, as well as the main characters in many fermentative production processes. In the last 40 years, advances in molecular biology and genetic engineering have made possible not only the genetic selection of organisms, but also the genetic modification of some of them, especially the simplest of them, such as bacteria and yeasts. These discoveries have led to the availability of new yeast strains fit to fulfill requests of industrial production and fermentation. Moreover, genetically modified and transformed yeasts have been constructed that are able to produce large amounts of biologically active proteins and enzymes. Thus, recombinant yeasts make it easier to produce drugs, biologically active products, diagnostics, and vaccines, by inexpensive and relatively simple techniques. Yeasts are going to become more and more important in the {open_quotes}biotechnological revolution{close_quotes} by virtue of both their features and their very long and safe use in human nutrition and industry. 175 refs., 4 figs., 6 tabs.

Russo, S.; Poli, G. [Univ. of Milan (Italy); Siman-Tov, R.B. [Univ. of Jerusalem, Rehovot (Israel)

1995-12-31

250

Yeasts from the leaves of pasture plants  

Microsoft Academic Search

The yeast population upon the leaves of pasture plants in New Zealand has been investigated in relation to season, soil yeast flora, and incidence of facial eczema toxin in autumn pasture. Leaf yeasts were shown to be taxonomically distinct from soil yeasts and to vary with season but not to vary with the localities sampled. During most of the year

M. E. di Menna

1959-01-01

251

Effects of Yeast Freezing in Frozen Dough  

Microsoft Academic Search

Cereal Chem. 80(4):454-458 The effects of freezing and frozen storage of bread dough and com- pressed yeast on bread quality were studied. Besides, the effects of compressed yeast freezing on cell viability, gas production and release of substances by the yeast cells were examined. Freezing and frozen storage of dough made with fresh yeast had more negative effects on baking

Pablo D. Ribotta; Alberto E. León; María Cristina Añón

2003-01-01

252

Yeasts in an industrial malting ecosystem  

Microsoft Academic Search

The malting ecosystem consists of two components: the germinating cereal grains and the complex microbial community. Yeasts and yeast-like fungi are an important part of this ecosystem, but the composition and the effects of this microbial group have been largely unknown. In this study we surveyed the development of yeasts and yeast-like fungi in four industrial scale malting processes. A

A. Laitila; A. Wilhelmson; E. Kotaviita; J. Olkku; S. Home; R. Juvonen

2006-01-01

253

A numericlature of the yeasts.  

PubMed

A numericlature, based on a descriptive numerical code has been compiled for the yeasts. A total of 429 yeast species are represented by 389 unique four-, six- or seven-digit numbers and of these 364 correspond to single species. It is suggested that the coding method is a valid alternative to binomial nomenclature based on a conventional hierarchical classification. It can serve as a simple reference system and can be used practically as a means of differentiating between large numbers of new isolates of yeasts. PMID:7337435

Griffiths, A J

1981-01-01

254

Development of baking yeast from Nigerian palm-wine yeasts  

Microsoft Academic Search

Two local strains of Saccharomyces cerevisiae, Nk, and Nk2, showed leavening activities of 103% and 102% of that of a commercial yeast strain on wheat flour and of 114% and 113% on composite dough with 40% (w\\/v) maize substitution. Yeast fusion products Nk\\/Ng, Nk\\/Nk1 and Nk\\/Nk2 showed activities of 104% to 113% on wheat flour and 111% to 131% on

A. O. Ejiofor; N. Okafor; E. N. Ugwueze

1994-01-01

255

Thermostability of yeast hexokinase and yeast glucose-6-phosphate dehydrogenase  

Microsoft Academic Search

Kinetic study of the mechanism of the temperature-induced loss of the catalytic activity by yeast hexokinase (HK) and yeast\\u000a glucose-6phosphate dehydrogenase (G-6-PDG) has shown the dissociative nature of the processes. In the temperature range 40–47°C,\\u000a they are satisfactorily described in terms of consecutive reactions in which steps of irreversible denaturation of the monomeric\\u000a units follow the reversible dissociation of inactive

E. A. Zaitzeva; E. S. Chukria; O. M. Poltorak

1996-01-01

256

Emergence of co-trimoxazole resistant Nocardia brasiliensis causing fatal pneumonia.  

PubMed

An 85-year-old man was admitted to the medical intensive care unit with a 10-day history of severe breathlessness, fever and cough. The patient was known to have chronic obstructive pulmonary disease and had been receiving corticosteroids in the preceding 18 months. He had been treated for tuberculosis 2.5 years previously. On examination he was febrile, tachycardic with a respiratory rate of 46/min. Auscultation revealed bilateral crepitation's and wheeze. Chest radiograph revealed patchy infiltrates on right lung. The patient developed respiratory depression and was mechanically ventilated. His sputum and endotracheal aspirates revealed Nocardia brasiliensis on culture which was found to be co-trimoxazole resistant. Once this became known imipenem was substituted for co-trimoxazole but unfortunately condition of the patient did not improve and he died following a cardiac arrest. PMID:23598938

Khare, Vineeta; Gupta, Prashant; Himanshu, D; Kumar, Deepak

2013-04-17

257

Dracunculus brasiliensis sp. n. (Nematoda: Dracunculidae) from the anaconda, Eunectes murinus (Ophidia: Boidae).  

PubMed

Dracunculus brasiliensis sp. n. (Dracunculidae), is described based on a single female specimen found in the body cavity of the anaconda, Eunectes murinus (L.) (Ophidia: Boidae), from the Mexiana Island, Amazon River delta, Brazil and one female previously recorded from the subcutaneous tissue of this host species imported from South America into Europe (ZOO in the Czech Republic). The new species is characterised mainly by markedly large, anteriorly protruding dorsal and ventral double papillae of the internal circle and small lateral papillae of the same circle, a widely rounded caudal end, the excretory pore situated just posterior to the nerve ring, a distinctly transversely striated cuticle and by the length (396-429 mum) of larvae from uterus. This is the first species of Dracunculus described from reptiles in South America. PMID:18975002

Moravec, F; Santos, C P

2008-10-30

258

Flight dispersal of the Chagas disease vectors Triatoma brasiliensis and Triatoma pseudomaculata in northeastern Brazil.  

PubMed

The present paper reports for the first time the capture of wild Triatoma brasiliensis and Triatoma pseudomaculata by means of light traps in Brazil. We tested commercially available lighting devices powered by batteries to attract the bugs to a white piece of cloth in the field. Two main findings showed to be significant: first, the results presented here show that light traps can be used for sampling these species in wild environments; second, they reveal that house colonization by triatomines may also happen as a consequence of the arrival of flying sylvatic bugs guided by artificial light sources. In addition, we discuss the effect of some environmental and biological factors on triatomine flight activity modulation. PMID:17292320

Carbajal de la Fuente, Ana L; Minoli, Sebastian A; Lopes, Catarina M; Noireau, François; Lazzari, Claudio R; Lorenzo, Marcelo G

2007-01-10

259

The primary structure of hevamine, an enzyme with lysozyme/chitinase activity from Hevea brasiliensis latex.  

PubMed

The primary structure of hevamine, an enzyme with lysozyme/chitinase activity from Hevea brasiliensis latex, has been determined predominantly with conventional non-automatic methods. The positions of three disulfide bridges have been determined. The sequence has about 60% identity with that of a chitinase from cucumber and 95% with the N-terminal sequence of the lysozyme/chitinase of Parthenocissus quinquefolia. The half-cystine residues in hevein and cucumber chitinase are located at identical positions. Hevamine is a basic protein from the lutoids (vacuoles) of rubber latex and may have a role in plugging the latex vessels and cessation of latex flow. The differences in cellular location, charge properties and sequence between hevamine and cucumber chitinase are similar to those between class I and class II chitinases from tobacco and other plant species. PMID:1879417

Jekel, P A; Hartmann, B H; Beintema, J J

1991-08-15

260

Patuletin acetylrhamnosides from Kalanchoe brasiliensis as inhibitors of human lymphocyte proliferative activity.  

PubMed

The fractionation of the juice of fresh stems and leaves of Kalanchoe brasiliensis was monitored by an assay measuring lymphocyte proliferative activity and allowed the isolation and identification of seven patuletin rhamnoside derivatives [1-7]. Three of them are novel, namely, patuletin 3-O-(4"-O-acetyl-alpha-L-rhamnopyranosyl)-7-O-(2'"-O-acetyl- alpha-L-rhamnopyranoside) [1], patuletin 3-O-alpha-L-rhamnopyranosyl-7-O-(2'"-O-acetyl-alpha-L- rhamnopyranoside) [3], and patuletin 3-O-(4"-O-acetyl-alpha-L-rhamnopyranosyl)-7-O- rhamnopyranoside [4], and four are known [2, 5-7]. Their structures were determined by the analysis of 1H-1H and 1H-13C COSY nmr, ci, and fab mass spectra. PMID:7853000

Costa, S S; Jossang, A; Bodo, B; Souza, M L; Moraes, V L

1994-11-01

261

Inhibitory effect of verbascoside isolated from Buddleja brasiliensis Jacq. ex Spreng on prolyl oligopeptidase activity.  

PubMed

The phenylpropanoid glycoside verbascoside [2-(3,4-dihydroxyphenylethyl)-1-O-?-L-rhamnopyranosyl-(1?3)-?-D-(4-O-caffeyl)-glucopyranoside] (1) has been isolated as the main constituent of the crude extract of Buddleja brasiliensis Jacq. ex Spreng from Southern Brazil. The crude extract, main fractions and the compound 1 were evaluated for inhibition of the enzymes acetylcholinesterase (AChE), dipeptidyl peptidase-IV (DPP-IV) and prolyl oligopeptidase (POP). Compound 1 showed weak activity against DPP-IV with an IC(50) > 150 µM and was inactive against AChE, with a pMIQ determined by bioautography of 9.6. In contrast, 1 displayed significant inhibition of POP in a dose-dependent manner with an IC(50) value of 1.3 ± 0.2 µM, similar to the positive control, baicalin, with a POP IC(50) of 12 ± 3 µM. PMID:22275311

Filho, Augusto G; Morel, Ademir F; Adolpho, Luciana; Ilha, Vinícius; Giralt, Ernest; Tarragó, Teresa; Dalcol, Ionara I

2012-01-25

262

Yeast rises to the occasion  

PubMed Central

Genetic analyses of 15 species of yeast have shed new light on the divergence of gene regulation during evolution, with significant changes occurring after an event in which a whole genome was duplicated.

2013-01-01

263

Molecular Genetic Analysis in Yeast  

NSDL National Science Digital Library

The four exercises presented here use basic and advanced procedures of recombinant DNA technology to perform molecular genetic analysis in the yeast Saccharomyces cerevisiae. Their fulluse is intended for a senior-level molecular genetics (or similar) course; however, Experiments 1, 2, and 4 are appropriate for lower-level courses. It is expected that the instructor will have some familiarity with the concepts and terminology of recombinant DNA technology and with yeast genetics.

Daniel D. Burke (Seton Hall University;)

1989-06-06

264

Yeast Pathogens of Domestic Animals  

Microsoft Academic Search

\\u000a Mycoses of domestic animals caused by yeasts have been recorded for approximately 150 years. The majority of these infections\\u000a are cutaneous and superficial and are of minor clinical significance but fatal systemic infections are also reported. Currently,\\u000a most common pathogenic yeasts of domestic animals are included in the genera Candida, Cryptococcus and Malassezia and they are reviewed in depth in

F. J. Cabanes

265

Biotechnological Applications of Dimorphic Yeasts  

Microsoft Academic Search

The dimorphic yeasts have the equilibrium between spherical growth (budding) and polarized (hyphal or pseudohyphal tip elongation)\\u000a which can be triggered by change in the environmental conditions. The reversible growth phenomenon has made dimorphic yeasts\\u000a as an useful model to understand fungal evolution and fungal differentiation, in general. In nature dimorphism is clearly\\u000a evident in plant and animal fungal pathogens,

N. Doiphode; C. Joshi; V. Ghormade; M. V. Deshpande

2009-01-01

266

Yeasts preservation: alternatives for lyophilisation.  

PubMed

The aim of the study was to compare the effect of two low-cost, low technology traditional methods for drying starter cultures with standard lyophilisation. Lyophilised yeast cultures and yeast cultures preserved in dry rice cakes and dry plant fibre strands were examined for viable cell counts during 6 months storage at 4 and 25 °C. None of the yeast cultures showed a significant loss in viable cell count during 6 months of storage at 4 °C upon lyophilisation and preservation in dry rice cakes. During storage at 25 °C in the dark, yeast cultures preserved in dry rice cakes, and lyophilised cultures of Saccharomyces cerevisiae and Issatchenkia orientalis showed no significant loss of viable cells up to 4 months of storage. Yeast cultures preserved in dry plant fibre strands had the greatest loss of viable count during the 6 months of storage at 25 °C. Preservation of yeasts cultures in dry rice cakes provided better survival during storage at 4 °C than lyophilisation. The current study demonstrated that traditional methods can be useful and effective for starter culture preservation in small-scale, low-tech applications. PMID:22806747

Nyanga, Loveness K; Nout, Martinus J R; Smid, Eddy J; Boekhout, Teun; Zwietering, Marcel H

2012-07-07

267

Study of amyloids using yeast  

PubMed Central

Summary Saccharomyces cerevisiae has been a useful model organism in such fields as the cell cycle, regulation of transcription, protein trafficking and cell biology, primarily because of its ease of genetic manipulation. This is no less so in the area of amyloid studies. The endogenous yeast amyloids described to date include prions, infectious proteins (Table 1), and some cell wall proteins (1). and amyloids of humans and a fungal prion have also been studied using the yeast system. Accordingly, the emphasis of this chapter will be on genetic, biochemical, cell biological and physical methods particularly useful in the study of yeast prions and other amyloids studied in yeast. We limit our description of these methods to those aspects which have been most useful in studying yeast prions, citing more detailed expositions in the literature. Volumes on yeast genetics methods (2–4), and on amyloids and prions (5, 6) are useful, and Masison has edited a volume of Methods on “Identification, analysis and characterization of fungal prions” which covers some of this territory (7). We also outline some useful physical methods, pointing the reader to more extensive and authoratative descriptions.

Wickner, Reed B.; Kryndushkin, Dmitry; Shewmaker, Frank; McGlinchey, Ryan; Edskes, Herman K.

2012-01-01

268

Riboneogenesis in yeast  

PubMed Central

Summary Gluconeogenesis converts three carbon units into glucose. Here we identify an analogous pathway in Saccharomyces cerevisiae for converting three carbon units into ribose, a component of nucleic acids and nucleotides. This riboneogenic pathway involves the enzyme sedoheptulose-1,7-bisphosphatase (SHB17), whose activity was identified based on accumulation of sedoheptulose-1,7-bisphosphate in the corresponding knockout strain. We determined the crystal structure of Shb17 in complex with sedoheptulose-1,7-bisphosphate, and found that the sugar is bound in the closed furan form in the active site. Like fructose-1,6-bisphosphate, sedoheptulose-1,7-bisphosphate is produced by aldolase, in this case from erythrose 4-phosphate and dihydroxyacetone phosphate. Hydrolysis of sedoheptulose-1,7-bisphosphate by SHB17 provides an energetically favorable input to the non-oxidative pentose phosphate pathway to drive ribose production. Flux through SHB17 is enhanced under conditions when ribose demand is high relative to demand for NADPH, including during ribosome biogenesis in metabolically synchronized yeast cells. Thus, riboneogenesis provides a thermodynamically-driven route of ribose production uncoupled from formation of NADPH.

Clasquin, Michelle F.; Melamud, Eugene; Singer, Alexander; Gooding, Jessica R.; Xu, Xiaohui; Dong, Aiping; Cui, Hong; Campagna, Shawn R.; Savchenko, Alexei; Yakunin, Alexander F.; Rabinowitz, Joshua D.; Caudy, Amy A.

2011-01-01

269

CaMV 35S promoter directs ?-glucuronidase expression in the laticiferous system of transgenic Hevea brasiliensis (rubber tree)  

Microsoft Academic Search

Hevea brasiliensis anther calli were genetically transformed using Agrobacterium GV2260 (p35SGUSINT) that harboured the ?-glucuronidase (gus) and neomycin phosphotransferase (nptII) genes. ?-Glucuronidase protein (GUS) was expressed in the leaves of kanamycin-resistant plants that were regnerated, and the presence\\u000a of the gene was confirmed by Southern analysis. GUS was also observed to be expressed in the latex and more importantly in

P. Arokiaraj; H. Yeet Yeang; K. Fong Cheong; S. Hamzah; H. Jones; S. Coomber; B. V. Charlwood

1998-01-01

270

Transcriptome analysis reveals novel features of the molecular events occurring in the laticifers of Hevea brasiliensis (para rubber tree)  

Microsoft Academic Search

Latex of Hevea brasiliensis (Willd. ex A, Juss.) Mull. Arg. (Brazilian rubber tree) contains 30–50% (w\\/w) of natural rubber (cis-1,4-polyisoprene), which is an important raw material for many industrial uses. In order to gain insights into the molecular events occurring in latex, we analyzed more than 20,000 cDNA-AFLP-based TDFs (transcription-derived fragments) and 1176 ESTs. The results revealed several novel features

Jae-Heung Ko; Keng-See Chow; Kyung-Hwan Han

2003-01-01

271

Wound-Induced Accumulation of mRNA Containing a Hevein Sequence in Laticifers of Rubber Tree (Hevea brasiliensis)  

Microsoft Academic Search

Hevein is a chitin-binding protein that is present in laticifers of the rubber tree (Hevea brasiliensis). A cDNA clone (HEV1) encoding hevein was isolated by using the polymerase chain reaction with mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea latex cDNA library as a template. HEV1 is 1018 base pairs long and includes an open

Willem Broekaert; Hyung-Il Lee; Anil Kush; Nam-Hai Chua; Natasha Raikhel

1990-01-01

272

Roosting ecology and variation in adaptive and innate immune system function in the Brazilian free-tailed bat ( Tadarida brasiliensis )  

Microsoft Academic Search

Bats have recently been implicated as reservoirs of important emerging diseases. However, few studies have examined immune\\u000a responses in bats, and even fewer have evaluated these responses in an ecological context. We examined aspects of both innate\\u000a and adaptive immune response in adult female Brazilian free-tailed bats (Tadarida brasiliensis) at four maternity roosts (two natural caves and two human-made bridges)

Louise C. Allen; Amy S. Turmelle; Mary T. Mendonça; Kristen J. Navara; Thomas H. Kunz; Gary F. McCracken

2009-01-01

273

Expression and characterization of active site mutants of hevamine, a chitinase from the rubber tree Hevea brasiliensis  

Microsoft Academic Search

Hevamine is a chitinase from the rubber tree Hevea brasiliensis. Its active site contains Asp125, Glu127, and Tyr183, which interact with the -1 sugar residue of the substrate. To investigate their role in catalysis, we have successfully expressed wild-type enzyme and mutants of these residues as inclusion bodies in Escherichia coli. After refolding and purification they were characterized by both

Bauke W. Dijkstra; Mark Sibbald; Henriëtte J. Rozeboom; Jaap J. Beintema; Evert Bokma

2002-01-01

274

The tiny difference between foraging and communication buzzes uttered by the Mexican free-tailed bat, Tadarida brasiliensis  

Microsoft Academic Search

Echolocating insectivorous bats consummate prey captures using a distinct vocal motor pattern commonly known as the terminal\\u000a or feeding buzz, which is widely considered a fixed motor pattern executed independently of auditory feedback influences.\\u000a The Mexican free-tailed bat, Tadarida brasiliensis, offers an opportunity to explore the role of sensory feedback in buzzing because they emit similar buzzes both in flight

Christine Schwartz; Jedidiah Tressler; Halli Keller; Marc Vanzant; Sarah Ezell; Michael Smotherman

2007-01-01

275

Hev b 8, the Hevea brasiliensis Latex Profilin, Is a Cross-Reactive Allergen of Latex, Plant Foods and Pollen  

Microsoft Academic Search

Background: Plant profilins are important pan-allergens. They are responsible for a significant percentage of pollen-related allergies. Limited information is available about their involvement in the latex-fruit syndrome and the cross-reactivities between latex and pollen. We aimed to clone and express the Hevea brasiliensis latex profilin to investigate its allergological significance and serological cross-reactivities to profilins from plant foods and pollens.

Erika Ganglberger; Christian Radauer; Stefan Wagner; Gabriel Ó Ríordáin; Donald H. Beezhold; Randolf Brehler; Bodo Niggemann; Otto Scheiner; Erika Jensen-Jarolim; Heimo Breiteneder

2001-01-01

276

Distribution of a Nocardia brasiliensis Catalase Gene Fragment in Members of the Genera Nocardia, Gordona, and Rhodococcus  

PubMed Central

An immunodominant protein from Nocardia brasiliensis, P61, was subjected to amino-terminal and internal sequence analysis. Three sequences of 22, 17, and 38 residues, respectively, were obtained and compared with the protein database from GenBank by using the BLAST system. The sequences showed homology to some eukaryotic catalases and to a bromoperoxidase-catalase from Streptomyces violaceus. Its identity as a catalase was confirmed by analysis of its enzymatic activity on H2O2 and by a double-staining method on a nondenaturing polyacrylamide gel with 3,3?-diaminobenzidine and ferricyanide; the result showed only catalase activity, but no peroxidase. By using one of the internal amino acid sequences and a consensus catalase motif (VGNNTP), we were able to design a PCR assay that generated a 500-bp PCR product. The amplicon was analyzed, and the nucleotide sequence was compared to the GenBank database with the observation of high homology to other bacterial and eukaryotic catalases. A PCR assay based on this target sequence was performed with primers NB10 and NB11 to confirm the presence of the NB10-NB11 gene fragment in several N. brasiliensis strains isolated from mycetoma. The same assay was used to determine whether there were homologous sequences in several type strains from the genera Nocardia, Rhodococcus, Gordona, and Streptomyces. All of the N. brasiliensis strains presented a positive result but only some of the actinomycetes species tested were positive in the PCR assay. In order to confirm these findings, genomic DNA was subjected to Southern blot analysis. A 1.7-kbp band was observed in the N. brasiliensis strains, and bands of different molecular weight were observed in cross-reacting actinomycetes. Sequence analysis of the amplicons of selected actinomycetes showed high homology in this catalase fragment, thus demonstrating that this protein is highly conserved in this group of bacteria.

Vera-Cabrera, Lucio; Johnson, Wendy M.; Welsh, Oliverio; Resendiz-Uresti, Francisco L.; Salinas-Carmona, Mario C.

1999-01-01

277

The Pivotal Role of 5-Lipoxygenase-Derived LTB4 in Controlling Pulmonary Paracoccidioidomycosis  

PubMed Central

Leukotrienes (LTs) produced from arachidonic acid by the action of 5-lipoxygenase (5-LO) are classical mediators of inflammatory responses. However, studies published in the literature regarding these mediators are contradictory and it remains uncertain whether these lipid mediators play a role in host defense against the fungal pathogen Paracoccidioides brasiliensis. To determine the involvement of LTs in the host response to pulmonary infection, wild-type and LT-deficient mice by targeted disruption of the 5-lipoxygenase gene (knockout mice) were studied following intratracheal challenge with P. brasiliensis yeasts. The results showed that infection is uniformly fatal in 5-LO-deficient mice and the mechanisms that account for this phenotype are an exacerbated lung injury and higher fungal pulmonary burden. Genetic ablation or pharmacological inhibition of LTs resulted in lower phagocytosis and fungicidal activity of macrophages in vitro, suggesting that deficiency in fungal clearance seems to be secondary to the absence of activation in 5-LO?/? macrophages. Exogenous LTB4 restored phagocytosis and fungicidal activity of 5-LO?/? macrophages. Moreover, P. brasiliensis killing promoted by LTB4 was dependent on nitric oxide (NO) production by macrophages. Taken together, these results reveal a fundamental role for 5-LO-derived LTB4 in the protective response to P. brasiliensis infection and identify relevant mechanisms for the control of fungal infection during the early stages of the host immune response.

Santos, Patricia Campi; Santos, Daniel Assis; Ribeiro, Lucas Secchim; Fagundes, Caio Tavares; de Paula, Talles Prosperi; Avila, Thiago Vinicius; Baltazar, Ludmila de Matos; Madeira, Mila Moreira; Cruz, Rosana de Carvalho; Dias, Ana Carolina Fialho; Machado, Fabiana Simao; Teixeira, Mauro Martins; Cisalpino, Patricia Silva; Souza, Danielle G.

2013-01-01

278

The Pivotal Role of 5-Lipoxygenase-Derived LTB4 in Controlling Pulmonary Paracoccidioidomycosis.  

PubMed

Leukotrienes (LTs) produced from arachidonic acid by the action of 5-lipoxygenase (5-LO) are classical mediators of inflammatory responses. However, studies published in the literature regarding these mediators are contradictory and it remains uncertain whether these lipid mediators play a role in host defense against the fungal pathogen Paracoccidioides brasiliensis. To determine the involvement of LTs in the host response to pulmonary infection, wild-type and LT-deficient mice by targeted disruption of the 5-lipoxygenase gene (knockout mice) were studied following intratracheal challenge with P. brasiliensis yeasts. The results showed that infection is uniformly fatal in 5-LO-deficient mice and the mechanisms that account for this phenotype are an exacerbated lung injury and higher fungal pulmonary burden. Genetic ablation or pharmacological inhibition of LTs resulted in lower phagocytosis and fungicidal activity of macrophages in vitro, suggesting that deficiency in fungal clearance seems to be secondary to the absence of activation in 5-LO(-/-) macrophages. Exogenous LTB4 restored phagocytosis and fungicidal activity of 5-LO(-/-) macrophages. Moreover, P. brasiliensis killing promoted by LTB4 was dependent on nitric oxide (NO) production by macrophages. Taken together, these results reveal a fundamental role for 5-LO-derived LTB4 in the protective response to P. brasiliensis infection and identify relevant mechanisms for the control of fungal infection during the early stages of the host immune response. PMID:23991239

Santos, Patrícia Campi; Santos, Daniel Assis; Ribeiro, Lucas Secchim; Fagundes, Caio Tavares; de Paula, Talles Prosperi; Avila, Thiago Vinícius; Baltazar, Ludmila de Matos; Madeira, Mila Moreira; Cruz, Rosana de Carvalho; Dias, Ana Carolina Fialho; Machado, Fabiana Simão; Teixeira, Mauro Martins; Cisalpino, Patrícia Silva; Souza, Danielle G

2013-08-22

279

The left lung is preferentially targeted during experimental paracoccidioidomycosis in C57BL/6 mice.  

PubMed

Paracoccidioidomycosis (PCM) is a chronic systemic mycosis caused by the inhalation of the thermally dimorphic fungus Paracoccidioides brasiliensis as well as the recently described P. lutzii. Because the primary infection occurs in the lungs, we investigated the differential involvement of the right and left lungs in experimental P. brasiliensis infection. Lungs were collected from C57BL/6 mice at 70 days after intravenous infection with 1×106 yeast cells of a virulent strain of P. brasiliensis (Pb18). The left lung, which in mice is smaller and has fewer lobes than the right lung, yielded increased fungal recovery associated with a predominant interleukin-4 response and diminished synthesis of interferon-? and nitric oxide compared with the right lung. Our data indicate differential involvement of the right and left lungs during experimental PCM. This knowledge emphasizes the need for an accurate, standardized protocol for tissue collection during studies of experimental P. brasiliensis infection, since experiments using the same lungs favor the collection of comparable data among different mice. PMID:24141611

Tristão, F S M; Rocha, F A; Dias, F C; Rossi, M A; Silva, J S

2013-10-02

280

The tiny difference between foraging and communication buzzes uttered by the Mexican free-tailed bat, Tadarida brasiliensis.  

PubMed

Echolocating insectivorous bats consummate prey captures using a distinct vocal motor pattern commonly known as the terminal or feeding buzz, which is widely considered a fixed motor pattern executed independently of auditory feedback influences. The Mexican free-tailed bat, Tadarida brasiliensis, offers an opportunity to explore the role of sensory feedback in buzzing because they emit similar buzzes both in flight during foraging and while stationary as communication sounds. Here we compared the spectral and temporal patterns of foraging and communication buzzes to address whether or not auditory feedback may influence buzz patterns. We found that while foraging buzzes uttered in open space were composed of generic FM calls, communication buzzes were composed of an adapted CF-FM call similar to the call type used by T. brasiliensis when navigating in confined spaces. This provides the first evidence that some bats can make significant context-dependent changes in the spectral parameters of calls within their buzz. We also found that inter-pulse intervals, but not call durations, were different within the two buzz types. These observations indicate that though a common pattern generator hierarchically organizes all buzzes, T. brasiliensis retains a significant capacity to adapt the spectral and temporal patterns of elements within its buzzes. PMID:17503051

Schwartz, Christine; Tressler, Jedidiah; Keller, Halli; Vanzant, Marc; Ezell, Sarah; Smotherman, Michael

2007-05-15

281

Immune Regulation of Protease-Activated Receptor-1 Expression in Murine Small Intestine during Nippostrongylus brasiliensis Infection  

PubMed Central

Infection with gastrointestinal nematodes exerts profound effects on both immune and physiological responses of the host. Helminth infection induces a hypercontractility of intestinal smooth muscle that is dependent on the Th2 cytokines, IL-4 and IL-13, and may contribute to worm expulsion. Protease-activated receptors (PARs) are expressed throughout the gut, and activation of PAR-1 was observed in asthma, a Th2-driven pathology. In the current study we investigated the physiologic and immunologic regulation of PAR-1 in the murine small intestine, specifically 1) the effect of PAR-1 agonists on small intestinal smooth muscle contractility, 2) the effects of Nippostrongylus brasiliensis infection on PAR-1 responses, 3) the roles of IL-13 and IL-4 in N. brasiliensis infection-induced alterations in PAR-1 responses, and 4) the STAT6 dependence of these responses. We demonstrate that PAR-1 activation induces contraction of murine intestinal smooth muscle that is enhanced during helminth infection. This hypercontractility is associated with an elevated expression of PAR-1 mRNA and protein. N. brasiliensis-induced changes in PAR-1 function and expression were seen in IL-4-deficient mice, but not in IL-13- or STAT6-deficient mice, indicating the dependence of IL-13 on the STAT6 signaling pathway independent of IL-4.

Zhao, Aiping; Morimoto, Motoko; Dawson, Harry; Elfrey, Justin E.; Madden, Kathleen B.; Gause, William C.; Min, Booki; Finkelman, Fred D.; Urban, Joseph F.; Shea-Donohue, Terez

2007-01-01

282

Alterations of intestinal motor responses to various stimuli after Nippostrongylus brasiliensis infection in rats: role of mast cells.  

PubMed

Nippostrongylus brasiliensis infection induces jejunal mastocytosis associated with enteric nerve remodelling in rats. The aim of this study was to evaluate the intestinal motility responses to meals and to neurotransmitters involved in the control of gut motility (acetylcholine (carbachol), substance P and neurokinin A) in both control and N. brasiliensis-infected rats 30 days post-infection. All rats were equipped with NiCr electrodes in the jejunum to record myoelectrical activity. The duration of disruption of the jejunal migrating myoelectrical complexes (MMC) induced by the different stimuli was determined. Meal ingestion and substance P administration disrupted the MMC pattern for similar durations in the two groups. Carbachol and neurokinin A induced a significantly longer MMC disruption in post-infected rats than in controls (125 +/- 8.3 vs. 70 +/- 6 min for carbachol 100 microg kg-1 and 51 +/- 4 vs. 40 +/- 2 for neurokinin A 50 microg kg-1). The enhanced motor response in postinfected rats was reduced by previous mast cell stabilization with ketotifen or mast cell degranulation with compound BrX 537 A. In conclusion, the increased intestinal motor reactivity to carbachol and neurokinin A in post-N. brasiliensis-infected rats depends upon intestinal mast cell hyperplasia and degranulation. PMID:10867617

Gay, J; Fioramonti, J; Garcia-Villar, R; Buéno, L

2000-06-01

283

Cdc42 Oscillations in Yeasts  

NSDL National Science Digital Library

A fundamental problem in cell biology is how cells define one or several discrete sites of polarity. Through mechanisms involving positive and negative feedback, the small Rho-family guanosine triphosphatase Cdc42 breaks symmetry in round budding yeast cells to define a single site of polarized cell growth. However, it is not clear how cells can define multiple sites of polarization concurrently. We discuss a study in which rod-shaped fission yeast cells, which naturally polarize growth at their two cell ends, exhibited oscillations of Cdc42 activity between these sites. We compare these findings with similar oscillatory behavior of Cdc42 detected in budding yeast cells and discuss the possible mechanism and functional outputs of these oscillations.

Felipe O. Bendezu (Switzerland;University of Lausanne REV); Sophie G. Martin (Switzerland;University of Lausanne REV)

2012-12-04

284

Candida zeylanoides: another opportunistic yeast.  

PubMed

A patient with a long history of scleroderma and gastrointestinal malabsorption requiring total parenteral nutrition was admitted with Candida zeylanoides fungemia. The yeast responded to therapy, but on two subsequent admissions for episodes of fever the blood cultures yielded the same yeast. The identity of the Candida species was established biochemically by both the API (Analytab) and Vitek system approaches. C. zeylanoides ATCC 20356 and ATCC 7351 served as controls for these analyses and for antifungal susceptibility studies and restriction endonuclease analyses of chromosomal DNA. These investigations indicated that representative isolates of the yeasts from the three episodes were identical and differed in several respects from the ATCC strains, which did not share many of the characteristics bands with the DNA restriction fragment analysis. C. zeylanoides variants capable of tolerating 35 degrees C can complicate the recovery of patients, especially individuals compromised by their underlying disease. PMID:1684799

Levenson, D; Pfaller, M A; Smith, M A; Hollis, R; Gerarden, T; Tucci, C B; Isenberg, H D

1991-08-01

285

Candida zeylanoides: another opportunistic yeast.  

PubMed Central

A patient with a long history of scleroderma and gastrointestinal malabsorption requiring total parenteral nutrition was admitted with Candida zeylanoides fungemia. The yeast responded to therapy, but on two subsequent admissions for episodes of fever the blood cultures yielded the same yeast. The identity of the Candida species was established biochemically by both the API (Analytab) and Vitek system approaches. C. zeylanoides ATCC 20356 and ATCC 7351 served as controls for these analyses and for antifungal susceptibility studies and restriction endonuclease analyses of chromosomal DNA. These investigations indicated that representative isolates of the yeasts from the three episodes were identical and differed in several respects from the ATCC strains, which did not share many of the characteristics bands with the DNA restriction fragment analysis. C. zeylanoides variants capable of tolerating 35 degrees C can complicate the recovery of patients, especially individuals compromised by their underlying disease. Images

Levenson, D; Pfaller, M A; Smith, M A; Hollis, R; Gerarden, T; Tucci, C B; Isenberg, H D

1991-01-01

286

Acaulospora brasiliensis comb. nov. and Acaulospora alpina (Glomeromycota) from upland Scotland: morphology, molecular phylogeny and DNA-based detection in roots.  

PubMed

Spores of two supposedly arbuscular mycorrhizal fungal species, new to the United Kingdom and recently described as Acaulospora alpina and Ambispora brasiliensis (Glomeromycota), were discovered in soil samples from moorland in upland Scotland. Soil and plant trap pot cultures were established, but attempts to establish these fungi in single-species pot cultures with Plantago lanceolata as host were unsuccessful. Nevertheless, based on a 1.5-kb DNA fragment spanning part of the small subunit rRNA gene, the internal transcribed spacer region and part of the large subunit rRNA gene, both these species could be detected directly in field-sampled roots, together with one uncultured species each of Scutellospora, Rhizophagus (former Glomus group Ab, or 'Glomus intraradices clade') and Acaulospora. Whereas A. alpina has characteristic morphological similarities to other species in its genus, A. brasiliensis morphologically has little in common with any other species in Ambispora. The molecular phylogeny, DNA barcoding and morphological evidence clearly place A. brasiliensis in the genus Acaulospora. We therefore rename the species, reported from Brazil and Scotland, as Acaulospora brasiliensis comb. nov., and discuss ecological aspects of the very different environments from which A. brasiliensis and A. alpina have been reported. PMID:21336507

Krüger, Manuela; Walker, Christopher; Schüssler, Arthur

2011-02-19

287

Construction and Characterization of Cellulolytic Yeasts,  

National Technical Information Service (NTIS)

The yeast Saccharomyces cerevisiae is used in many biotechnical processes where plant raw material is utilized. However, S. cerevisiae cannot hydrolyse cellulose, the major renewable resource on earth. The successful construction of cellulolytic yeast str...

M. Penttilae

1987-01-01

288

Yeast Can Affect Behavior and Learning.  

ERIC Educational Resources Information Center

|A pediatrician recounts his experiences in diagnosing and treating allergies to common yeast germs that may result in behavior and learning problems. He lists characteristics that may predispose children to yeast-connected health problems. (CL)|

Crook, William G.

1984-01-01

289

Effect of yeast growth conditions on yeast-mycelial transition in Candida albicans  

Microsoft Academic Search

When grown and induced to form germ tubes in liquid defined media, yeast cells of Candida albicans must reach stationary phase before acquiring ability to carry out the yeast-mycelial transition. This study examined the effect of the carbon source utilized for yeast growth on the inducibility of stationary phase yeast. When grown to the same stationary phase cell density as

William M. Bell; W. LaJean Chaffin

1983-01-01

290

Chromatin and Transcription in Yeast  

PubMed Central

Understanding the mechanisms by which chromatin structure controls eukaryotic transcription has been an intense area of investigation for the past 25 years. Many of the key discoveries that created the foundation for this field came from studies of Saccharomyces cerevisiae, including the discovery of the role of chromatin in transcriptional silencing, as well as the discovery of chromatin-remodeling factors and histone modification activities. Since that time, studies in yeast have continued to contribute in leading ways. This review article summarizes the large body of yeast studies in this field.

Rando, Oliver J.; Winston, Fred

2012-01-01

291

Oily yeasts as oleaginous cell factories  

Microsoft Academic Search

Oily yeasts have been described to be able to accumulate lipids up to 20% of their cellular dry weight. These yeasts represent\\u000a a minor proportion of the total yeast population, and only 5% of them have been reported as able to accumulate more than 25%\\u000a of lipids. The oily yeast genera include Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces.

Jose Manuel Ageitos; Juan Andres Vallejo; Patricia Veiga-Crespo; Tomas G. Villa

2011-01-01

292

Phylogenetics of Saccharomycetales, the ascomycete yeasts  

Microsoft Academic Search

Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial

Sung-Oui Suh; Meredith Blackwell; Cletus P. Kurtzman; M.-A. Lachance

2006-01-01

293

Temperature abuse initiating yeast growth in yoghurt  

Microsoft Academic Search

The occurrence of yeasts in dairy products is significant because they can cause spoilage, effect desirable biochemical changes and they may adversely affect public health. While fermentative and spoilage activities of yeasts at elevated temperatures are well known in many food and beverage commodities, little attention has been given to the specific occurrence and significance of yeasts in dairy products

Bennie C. Viljoen; Analie Lourens-Hattingh; Bridget Ikalafeng; Gabor Peter

2003-01-01

294

Genetically modified industrial yeast ready for application  

Microsoft Academic Search

Tremendous progress in the genetic engineering of yeast had been achieved at the end of 20th century, including the complete genome sequence, genome-wide gene expression profiling, and whole gene disruption strains. Nevertheless, genetically modified (GM) baking, brewing, wine, and sake yeasts have not, as yet, been used commercially, although numerous industrial recombinant yeasts have been constructed. The recent progress of

Rinji Akada

2002-01-01

295

Yeast: A Research Organism for Teaching Genetics.  

ERIC Educational Resources Information Center

|Explains why laboratory strains of bakers yeast, Saccharomyces cerevisiae, are particularly suited for classroom science activities. Describes the sexual life cycle of yeast and the genetic system with visible mutations. Presents an overview of activities that can be done with yeast and gives a source for teachers to obtain more information. (PR)|

Manney, Thomas R.; Manney, Monta L.

1992-01-01

296

Enological functions of parietal yeast mannoproteins  

Microsoft Academic Search

Parietal yeast mannoproteins play a very important role in the overall vinification process. Their production and release, both during winemaking and aging on lees, depends on the specific yeast strain and the nutritional conditions. The following enological functions of parietal yeast mannoproteins have been described: (a) adsorption of ochratoxin A; (b) combination with phenolic compounds; (c) increased growth of malolactic

Andrea Caridi

2006-01-01

297

Leishmanicidal activity of benzophenones and extracts from Garcinia brasiliensis Mart. fruits.  

PubMed

Infections by protozoans of the genus Leishmania are the major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which exert renal and cardiac toxicity. Thus, there is a strong need for safer and more effective treatments against leishmaniasis. The present study was designated to evaluate, by a bioguided assay, the leishmanicidal activity of extracts (hexane, ethyl-acetate and ethanolic) and molecules both obtained by means of extraction from pericarps of Garcinia brasiliensis fruits. The hexane extract presented the best activity on the extracellular (promastigotes) and intracellular (amastigotes) forms of Leishmania (L.) amazonensis, when compared to the other extracts. Based on these findings, this extract was fractionated by silica gel column chromatography, affording nine fractions then resulting in three purified prenylated benzophenones - 7-epi-clusianone (1), garciniaphenone (2) and guttiferone-a (3). They showed significant activity on Leishmania (L.) amazonensis, and little toxicity for mammalian cells. Structure-activity relationships were evaluated showing that the IC(50) value displayed is dependent of prenyl groups and phenolic hydroxyls number, and inversely proportional to the hydrophobicity. Our results are promising, showing that these compounds are biologically active on Leishmania (L.) amazonensis. PMID:19762221

Pereira, I O; Marques, M J; Pavan, A L R; Codonho, B S; Barbiéri, C L; Beijo, L A; Doriguetto, A C; D'Martin, E C; dos Santos, M H

2009-09-16

298

Cloning and molecular characterization of a cDNA encoding a small GTPase from Hevea brasiliensis.  

PubMed

Small GTPases play a critical role in the regulation of a range of cellular processes including growth, differentiation, and intracellular transportation. The cDNA encoding a small GTPase, designated as HbGTPase1, was isolated from Hevea brasiliensis. HbGTPase1 was 882 bp long containing a 612-bp open reading frame encoding a putative protein of 203 amino acids, flanked by an 83-bp 5'-untranslated region (UTR) and a 187-bp 3'-UTR. The predicted molecular mass of HbGTPase1 is 22.62 kDa, with an isoelectric point of 5.06. The HbGTPase1 protein was predicted to possess the conserved functional regions of the small GTPase superfamily of proteins. Quantitative polymerase chain reaction analysis revealed that HbGTPase1 was constitutively expressed in all tissues tested. HbGTPase1 transcripts accumulated at relatively low levels in the flower, latex, and leaves, while HbGTPase1 transcripts accumulated at relatively high levels in bark. Transcription of HbGTPase1 in the latex was induced by jasmonate. PMID:24065672

Li, H L; Guo, D; Tian, W M; Peng, S Q

2013-09-03

299

A novel and enantioselective epoxide hydrolase from Aspergillus brasiliensis CCT 1435: Purification and characterization.  

PubMed

A novel epoxide hydrolase from Aspergillus brasiliensis CCT1435 (AbEH) was cloned and overexpressed in Escherichia coli cells with a 6xHis-tag and purified by nickel affinity chromatography. Gel filtration analysis and circular dichroism measurements indicated that this novel AbEH is a homodimer in aqueous solution and contains the typical secondary structure of an ?/? hydrolase fold. The activity of AbEH was initially assessed using the fluorogenic probe O-(3,4-epoxybutyl) umbelliferone and was active in a broad range of pH (6-9) and temperature (25-45°C); showing optimum performance at pH 6.0 and 30°C. The Michaelis constant (KM) and maximum rate (Vmax) values were 495?M and 0.24?M/s, respectively. Racemic styrene oxide (SO) was used as a substrate to assess the AbEH activity and enantioselectivity, and 66% of the SO was hydrolyzed after only 5min of reaction, with the remaining (S)-SO ee exceeding 99% in a typical kinetic resolution behavior. The AbEH-catalyzed hydrolysis of SO was also evaluated in a biphasic system of water:isooctane; (R)-diol in 84% ee and unreacted (S)-SO in 36% ee were produced, with 43% conversion in 24h, indicating a discrete enantioconvergent behavior for AbEH. This novel epoxide hydrolase has biotechnological potential for the preparation of enantiopure epoxides or vicinal diols. PMID:23973866

Beloti, Lilian L; Costa, Bruna Z; Toledo, Marcelo A S; Santos, Clelton A; Crucello, Aline; Fávaro, Marianna T P; Santiago, André S; Mendes, Juliano S; Marsaioli, Anita J; Souza, Anete P

2013-08-21

300

Hevea brasiliensis cell suspension peroxidase: purification, characterization and application for dye decolorization  

PubMed Central

Peroxidases are oxidoreductase enzymes produced by most organisms. In this study, a peroxidase was purified from Hevea brasiliensis cell suspension by using anion exchange chromatography (DEAE-Sepharose), affinity chromatography (Con A-agarose) and preparative SDS-PAGE. The obtained enzyme appeared as a single band on SDS-PAGE with molecular mass of 70 kDa. Surprisingly, this purified peroxidase also had polyphenol oxidase activity. However, the biochemical characteristics were only studied in term of peroxidase because similar experiments in term of polyphenol oxidase have been reported in our pervious publication. The optimal pH of the purified peroxidase was 5.0 and its activity was retained at pH values between 5.0–10.0. The enzyme was heat stable over a wide range of temperatures (0–60°C), and less than 50% of its activity was lost at 70°C after incubation for 30 min. The enzyme was completely inhibited by ?-mercaptoethanol and strongly inhibited by NaN3; in addition, its properties indicated that it was a heme containing glycoprotein. This peroxidase could decolorize many dyes; aniline blue, bromocresol purple, brilliant green, crystal violet, fuchsin, malachite green, methyl green, methyl violet and water blue. The stability against high temperature and extreme pH supported that the enzyme could be a potential peroxidase source for special industrial applications.

2013-01-01

301

Antiproliferative effects of lectins from Canavalia ensiformis and Canavalia brasiliensis in human leukemia cell lines.  

PubMed

The antiproliferative activity of lectins Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) were studied using human leukemia MOLT-4 and HL-60 cell lines. It was revealed that both ConA and ConBr were markedly cytotoxic to cells using MTT and NAC assays. The IC(50) values were approximately 3 and 20 ?g/mL for ConA and ConBr, respectively, for both MOLT-4 and HL-60 cells. However, in normal human peripheral blood lymphocytes, the lectins were not cytotoxic, even when tested at concentrations as high as 200 ?g/ml. Using comet assay, the lectins produced a rate of DNA damage exceeding 80% in MOLT-4 and HL-60 cells. Fluorescence analysis revealed the morphology characteristic of apoptosis, with low concentrations of apoptotic bodies and fragmented DNA (5 ?g/ml). Flow cytometric analysis demonstrated an accumulation of cells in the sub-G1 cell cycle that is characteristic of DNA fragmentation, and a decrease in membrane integrity at high concentrations. Lastly, we evaluated the alterations in mitochondrial potential that reduced after treatment with lectins. Our results indicate that ConA and ConBr inhibited cell proliferation selectively in tumor cells and that apoptosis was the main death mechanism. Therefore, lectins can be considered a class of molecules with a high antitumor activity potential. PMID:22776218

Faheina-Martins, Glaucia V; da Silveira, Alethéia Lacerda; Cavalcanti, Bruno C; Ramos, Márcio V; Moraes, Manoel O; Pessoa, Cláudia; Araújo, Demetrius A M

2012-07-07

302

Rubber (Hevea brasiliensis) seed oil toxicity effect and Linamarin compound analysis  

PubMed Central

Background The lipid fraction of rubber (Hevea brasiliensis (kunth. Muell)) seed was extracted and analyzed for toxicological effect. The toxicological compound such as linamarin in rubber seed oil (RSO) extracted using different solvents, such as hexane (RSOh), mixture of chloroform?+?methanol (RSOchl+mth) and ethanol (RSOeth) were also studied. Various methods analysis such as Fourier transforms infrared spectroscopy (FTIR) and colorimetric methods were carried out to determine the present of such compounds. Results FTIR spectrum of RSO did not show any presence of cyanide peak. The determination of cyanide by using colorimetric method was demonstrated no response of the cyanide in RSO and didn’t show any colored comparing with commercial cyanide which observed blue color. The results showed that no functional groups such as cyanide (C???N) associated with linamarin were observed. Toxicological test using rats was also conducted to further confirm the absence of such compounds. RSO did not show any toxic potential to the rats. Bioassay experiments using shrimps had been used as test organisms to evaluate the toxicity of linamarin extract from RSOh, RSOchl+mth and RSOeth and LC50 were found to be (211.70?%, 139.40?%, and 117.41?%, respectively). Conclusions This can be attributed no hazardous linamarin were found in RSO.

2012-01-01

303

Aid to a Declining Matriarch in the Giant Otter (Pteronura brasiliensis)  

PubMed Central

Scientists are increasingly revealing the commonalities between the intellectual, emotional and moral capacities of animals and humans. Providing assistance to elderly and ailing family members is a human trait rarely documented for wild animals, other than anecdotal accounts. Here I report observations of multiple forms of assistance to the declining matriarch of a habituated group of giant otters (Pteronura brasiliensis) in Manu National Park, Peru. The otter group had been observed annually for several years and all members were known individually. In 2007, the breeding female of the group failed to reproduce and appeared to be in physical decline. She begged from other family members 43 times over 41 contact hours and received food 11 times. Comparisons with 2004–2006 demonstrate that the family's behavior in 2007 constitutes a role-reversal, in which the majority of assistance and prey transfers accrued from young-to-old rather than from old-to-young. As in human societies, both non-adaptive and adaptive hypotheses could explain the family members' aid to their declining matriarch. I suggest that giant otter families may benefit from the knowledge and experience of an elderly matriarch and “grandparent helper,” consistent with the “Grandmother Hypothesis” of adaptive menopause in women.

Davenport, Lisa C.

2010-01-01

304

Reversible immobilization of giant otters (Pteronura brasiliensis) using medetomidine-ketamine and atipamezole.  

PubMed

This communication reports a partially reversible chemical immobilization protocol used for translocation and veterinary care in giant otter (Pteronura brasiliensis; GO). Six GOs (three males and three females) weighing 24.8 +/- 4.0 kg (mean +/- SD) and ranging in age from 16 to 42 mo old were anesthetized with an i.m. combination of medetomidine (29 +/- 3 microg/kg) and ketamine (3.9 +/- 0.4 mg/kg). To perform all procedures, two otters required an additional dose of ketamine (1.5 mg/kg). Anesthesia was reversed with atipamezole i.m. (147 +/- 14 mg/kg). The mean induction time and recovery times were 12 +/- 5 and 4 min (range, 0-9 min), respectively, with an anesthesia time of 47 +/- 16 min. According to these results, the combination of medetomidine (30 microg/kg i.m.) and ketamine (4 mg/kg i.m.) is a reasonable choice for inducing anesthesia in GOs. PMID:20597232

Bauquier, Sébastien H; Hinshaw, Keith C; Ialeggio, Donna M; Montgomery, Christopher L; Perkowski, Sandra Z

2010-06-01

305

Effects of DDE on experimentally poisoned free-tailed bats (Tadarida brasiliensis): Lethal brain concentrations  

USGS Publications Warehouse

Adult female free-tailed bats (Tadarida brasiliensis) were collected at Bracken Cave, Texas, and shipped to the Patuxent Wildlife Research Center. Treated mealworms (Tenebrio molitor) containing 107 ppm DDE were fed to 17 bats; five other bats were fed untreated mealworms. After 40 days on dosage, during which one dosed bat was killed accidentally, four dosed bats were frozen and the remaining 17 were starved to death. The objective was to elevate brain levels of DDE to lethality and measure these concentrations. After the feeding period, dosed bats weighed less than controls. After starvation, the body condition of dosed bats was poorer than that of controls even though there was no difference in the amounts of carcass fat. During starvation, dosed bats lost weight faster than controls. Also, four dosed bats exhibited the prolonged tremoring that characterizes DDE poisoning. DDE increased in brains of starving bats as fat was metabolized. The estimated mean brain concentration of DDE diagnostic of death was 519 ppm with a range of 458-564 ppm. These values resemble diagnostic levels known for two species of passerine birds, but they exceed published levels for two free-tailed bats from Carlsbad Caverns, New Mexico.

Clark, D.R., Jr.; Kroll, J.C.

1977-01-01

306

Amyloids and yeast prion biology.  

PubMed

The prions (infectious proteins) of Saccharomyces cerevisiae are proteins acting as genes, by templating their conformation from one molecule to another in analogy to DNA templating its sequence. Most yeast prions are amyloid forms of normally soluble proteins, and a single protein sequence can have any of several self-propagating forms (called prion strains or variants), analogous to the different possible alleles of a DNA gene. A central issue in prion biology is the structural basis of this conformational templating process. The in-register parallel ? sheet structure found for several infectious yeast prion amyloids naturally suggests an explanation for this conformational templating. While most prions are plainly diseases, the [Het-s] prion of Podospora anserina may be a functional amyloid, with important structural implications. Yeast prions are important models for human amyloid diseases in general, particularly because new evidence is showing infectious aspects of several human amyloidoses not previously classified as prions. We also review studies of the roles of chaperones, aggregate-collecting proteins, and other cellular components using yeast that have led the way in improving the understanding of similar processes that must be operating in many human amyloidoses. PMID:23379365

Wickner, Reed B; Edskes, Herman K; Bateman, David A; Kelly, Amy C; Gorkovskiy, Anton; Dayani, Yaron; Zhou, Albert

2013-02-12

307

Molecular Genetic Analysis in Yeast  

NSDL National Science Digital Library

This resource provides techniques and protocols used in basic and advanced procedures of recombinant DNA technology to perform molecular genetic analysis in the yeast Saccharomyces cerevisiae. Students will be exposed to techniques such as transformation, restriction endonuclease digestion, electrophoresis and Southern blot analysis.

Daniel D. Burke (Seton Hall University;)

1990-01-01

308

Optical micromanipulations inside yeast cells  

Microsoft Academic Search

We present a combination of nonlinear microscopy and optical trapping applied to three-dimensional imaging and manipulation of intracellular structures in living cells. We use Titanium-sapphire laser pulses for nonlinear microscopy of the nuclear envelope and the microtubules marked with green fluorescent protein in fission yeast. The same laser source is also used to trap small lipid granules naturally present in

Leonardo Sacconi; Iva M. Tolic-Nørrelykke; Chiara Stringari; Renzo Antolini; Francesco S. Pavone

2005-01-01

309

Telomere functions: lessons from yeast  

Microsoft Academic Search

Telomeres are specialized DNA protein structures that form the ends of eukaryotic chromosomes. In yeast, loss of even a single telomere causes a prolonged, but transitory, cell-cycle arrest. During this arrest, many broken chromosomes acquire a new telomere by one of three pathways, although at the cost of a partial loss of heterozygosity. In addition, a substantial fraction of the

Virginia A. Zakian

1996-01-01

310

TDP-43 toxicity in yeast  

PubMed Central

The budding yeast Saccharomyces cerevisiae is an emerging tool for investigating the molecular pathways that underpin several human neurodegenerative disorders associated with protein misfolding. Amyotrophic lateral sclerosis (ALS) is a devastating adult onset neurodegenerative disease primarily affecting motor neurons. The protein TDP-43 has recently been demonstrated to play an important role in the disease, however the mechanisms by which TDP-43 contributes to pathogenesis are unclear. To explore the mechanistic details that result in aberrant accumulation of TDP-43 and to discover potential strategies for therapeutic intervention, we employed a yeast TDP-43 proteinopathy model system. These studies allowed us to determine the regions of TDP-43 required for aggregation and toxicity and to define the effects of ALS-linked mutant forms of TDP-43. We have also been able to harness the power of yeast genetics to identify potent modifiers of TDP-43 toxicity using high-throughput yeast genetic screens. Here, we describe the methods and approaches that we have used in order to gain insight into TDP-43 biology and its role in disease. These approaches are readily adaptable to other neurodegenerative disease proteins.

Armakola, Maria; Hart, Michael P.; Gitler, Aaron D.

2010-01-01

311

Yeast sphingolipids: metabolism and biology  

Microsoft Academic Search

Sphingolipids have recently emerged as important bioactive molecules in addition to being critical structural components of cellular membranes. These molecules have been implicated in regulating cell growth, differentiation, angiogenesis, apoptosis, and senescene. To study sphingolipid mediated biology, it is necessary to investigate sphingolipid metabolism and its regulation. The yeast Saccharomyces cerevisiae has allowed such studies to take place as the

Lina M Obeid; Yasuo Okamoto; Cungui Mao

2002-01-01

312

Barcoding the Yeasts – Which Genes?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Old style yeast identification, as many know, is an onerous process requiring determination of growth reactions on 60-100 different media. Once completed, there is still a high degree of uncertainty about species identity. With the determination of sequences for domains 1 and 2 (D1/D2) of the nucl...

313

Observations on the Yeast Lipomyces  

Microsoft Academic Search

IN 1946, Starkey1 isolated and described a soil yeast characterized by a peculiar method of spore formation after a relatively long period of growth on solid medium. Large, round vegetative cells containing fat globules gave rise to irregularly shaped protuberances in which were afterwards formed 4-16 or more lightly pigmented spores. Lodder and Kregervan Rij2 considered these spores to be

Catherine Roberts

1957-01-01

314

Elimination of systemic contamination in explant and protoplast cultures of rubber ( Hevea brasiliensis Muell. Arg.)  

Microsoft Academic Search

Ten systemic microorganisms (bacteria and yeasts) were isolated from stem sections of ex vitro grown rubber plants. Antibiotics were screened for their efficacy against these microorganisms and for possible tissue phytotoxicity. Erythromycin, nystatin and streptomycin at bactericidal levels were asymptomatic in relation to tissue stress nor was callusing capacity reduced. Contamination of stem explants as used for callus initiation, was

Zoe A. Wilson; John B. Power

1989-01-01

315

Genetically modified industrial yeast ready for application.  

PubMed

Tremendous progress in the genetic engineering of yeast had been achieved at the end of 20th century, including the complete genome sequence, genome-wide gene expression profiling, and whole gene disruption strains. Nevertheless, genetically modified (GM) baking, brewing, wine, and sake yeasts have not, as yet, been used commercially, although numerous industrial recombinant yeasts have been constructed. The recent progress of genetic engineering for the construction of GM yeast is reviewed and possible requirements for their application are discussed. 'Self-cloning' yeast will be the most likely candidate for the first commercial application of GM microorganisms in food and beverage industries. PMID:16233347

Akada, Rinji

2002-01-01

316

Occurrence and Growth of Yeasts in Yogurts  

PubMed Central

Yogurts purchased from retail outlets were examined for the presence of yeasts by being plated onto oxytetracycline malt extract agar. Of the 128 samples examined, 45% exhibited yeast counts above 103 cells per g. A total of 73 yeast strains were isolated and identified as belonging to the genera Torulopsis, Kluyveromyces, Saccharomyces, Candida, Rhodotorula, Pichia, Debaryomyces, and Sporobolomyces. Torulopsis candida and Kluyveromyces fragilis were the most frequently isolated species, followed by Saccharomyces cerevisiae, Rhodotorula rubra, Kluyveromyces lactis, and Torulopsis versatilis. The growth of yeasts in yogurts was related to the ability of the yeasts to grow at refrigeration temperatures, to ferment lactose and sucrose, and to hydrolyze milk casein. Most yeast isolates grew in the presence of 100 ?g of sorbate and benzoate preservatives per ml. Higher yeast counts from yogurts were obtained when the yogurts were plated onto oxytetracycline malt extract agar than when they were plated onto acidified malt extract agar.

Suriyarachchi, V. R.; Fleet, G. H.

1981-01-01

317

The role of complement in innate, adaptive and eosinophil-dependent immunity to the nematode Nippostrongylus brasiliensis.  

PubMed

Complement may be important for immunity to infection with parasitic helminths, by promoting the recruitment of leukocytes to infected tissues and by modulating the function of cytotoxic effector leukocytes. However, the importance of complement in vivo during helminth infection is poorly understood. In this study, mice lacking classical (C1q-deficient), alternative (factor B-deficient) or all pathways of complement activation (C3-deficient) were used to assess the role of complement in immunity to the nematode Nippostrongylus brasiliensis. Double-mutant complement-deficient/IL-5 transgenic (Tg) mice were used to determine if complement is required for the strong eosinophil-dependent resistance to this parasite. Complement activation on larvae (C3 deposition), extracellular eosinophil peroxidase activity, larval aggregation and eosinophil recruitment to the skin 30 min post-injection (p.i.) of larvae were reduced in factor B-deficient mice. Inhibition of the C5a receptor with the antagonist PMX53 impaired eosinophil and neutrophil recruitment to the skin. C3 deposition on larvae was minimal by 150 min p.i. and at this time cell adherence, larval aggregation, eosinophil recruitment and degranulation were complement-independent. Factor B and C3 deficiency were associated with higher lung larval burdens in primary infections. Complement-deficient/IL-5 Tg mice were highly resistant to N. brasiliensis, suggesting that eosinophils can limit infection in a complement-independent manner. Potent secondary immunity was similarly complement-independent. In conclusion, although the alternative pathway is important for parasite recognition and leukocyte recruitment early in N. brasiliensis infections, the parasite soon becomes resistant to complement and other factors can compensate to promote eosinophil-dependent immunity. PMID:17675237

Giacomin, Paul R; Gordon, David L; Botto, Marina; Daha, Mohamed R; Sanderson, Sam D; Taylor, Stephen M; Dent, Lindsay A

2007-08-01

318

Antifungal susceptibilities of Sporothrix albicans, S. brasiliensis, and S. luriei of the S. schenckii complex identified in Brazil.  

PubMed

We studied 40 strains of the species complex formerly classified as the single species Sporothrix schenckii to identify new species within this complex and evaluate their antifungal susceptibility profiles. Based on phenotypic tests (ability to grow at 37°C, colony diameters, and pigmentation of the colonies, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), here we report the identification of S. albicans, S. brasiliensis, S. luriei, and S. schenckii; two isolates of these species were detected as itraconazole-resistant strains. PMID:21653757

Oliveira, Daniele C; Lopes, Paulo G Markus; Spader, Tatiana B; Mahl, Camila D; Tronco-Alves, Giordano R; Lara, Valeria M; Santurio, Janio M; Alves, Sydney Hartz

2011-06-08

319

Characterization and cytotoxic activity of sulfated derivatives of polysaccharides from Agaricus brasiliensis.  

PubMed

Agaricus brasiliensis cell-wall polysaccharides isolated from fruiting body (FR) and mycelium (MI) and their respective sulfated derivatives (FR-S and MI-S) were chemically characterized using elemental analysis, TLC, FT-IR, NMR, HPLC, and thermal analysis. Cytotoxic activity was evaluated against A549 tumor cells by MTT and sulforhodamine assays. The average molecular weight (Mw) of FR and MI was estimated to be 609 and 310 kDa, respectively. FR-S (127 kDa) and MI-S (86 kDa) had lower Mw, probably due to hydrolysis occurring during the sulfation reaction. FR-S and MI-S presented ~14% sulfur content in elemental analysis. Sulfation of samples was characterized by the appearance of two new absorption bands at 1253 and 810 cm(-1) in the infrared spectra, related to S=O and C-S-O sulfate groups, respectively. Through (1)H and (13)C NMR analysis FR-S was characterized as a (1?6)-(1?3)-?-D-glucan fully sulfated at C-4 and C-6 terminal and partially sulfated at C-6 of (1?3)-?-D-glucan moiety. MI-S was shown to be a (1?3)-?-D-gluco-(1?2)-?-D-mannan, partially sulfated at C-2, C-3, C-4, and C-6, and fully sulfated at C-6 of the terminal residues. The combination of high degree of sulfation and low molecular weight was correlated with the increased cytotoxic activity (48 h of treatment) of both FR-S (EC??=605.6 ?g/mL) and MI-S (EC??=342.1 ?g/mL) compared to the non-sulfated polysaccharides FR and MI (EC??>1500 ?g/mL). PMID:23511057

Cardozo, F T G S; Camelini, C M; Cordeiro, M N S; Mascarello, A; Malagoli, B G; Larsen, I V; Rossi, M J; Nunes, R J; Braga, F C; Brandt, C R; Simões, C M O

2013-03-17

320

Impact of age of rubber (Hevea brasiliensis) plantation on earthworm communities of West Tripura (India).  

PubMed

A comparative analysis of earthworm communities was carried out in the rubber plantations (Hevea brasiliensis) of different age groups in West Tripura to understand the impact of such exotic and monoculture plantation in biodiversity conservation. Earthworm communities were studied on monthly basis over a period of one year (2006-2007) in the 3, 10, 14, 20 and 25 year-old plantations. Among twelve earthworm species collected from the studied sites, six species belonged to Octochaetidae [Eutyphoeus assomensis Stephenson, Eutyphoeus comillahnus Michaelsen, Lennogaster chittagongensis (Stephensen), Octochaetona beatrix Gates, Dichogaster offinis Michaelsen, Lennogaster yeicus (Stephensen)], two species each to Megascolecidae [Metaphire houlleti (Perrier), Konchurio sp. 1] and Moniligastridae [Drowida nepalensis Michaelsen, Drawida papillifer papillifer Stephenson], one species each to Glossoscolecidae [Pontoscolex corethrurus (Muller)] and Ocnerodrilidae [Gordiodrilus elegans Beddard]. Exotic species P corethrurus, M. houlleti and native peregrine species like D. nepolensis and D. papillifer papillifer were distributed in all the age groups of plantation, while other species showed restricted distribution. P. corethrurus contributed more than 60% biomass and 70% density of earthworm communities in rubber plantation. With aging of rubber plantations both the densities and biomasses of earthworms increased. High contents of polyphenol, flavonoid and lignin in the litters of 3 and 10 year-old-rubber plantations through their effects on food intake, probably resulted to low biomass values of earthworms in those age groups of plantation. With further increase in the age of plantations beyond 10 years, polyphenol, flavonoid and lignin contents decreased. Accordingly the biomass of earthworms increased with increase in the age of plantation. Soil moisture increased with increase in the age of plantation and there was a good positive correlation between soil moisture and earthworm biomass (p < 0.01). Density, biomass and dominance of earthworms increased while species diversity, species richness and species evenness of earthworm community were decreased with increase in the age of rubber plantation. PMID:24006808

Chaudhuri, P S; Bhattacharjee, Subhalaxmi; Dey, Animesh; Chattopadhyay, Sharmila; Bhattacharya, Dipto

2013-01-01

321

The Latex of Hevea brasiliensis Contains High Levels of Both Chitinases and Chitinases/Lysozymes 1  

PubMed Central

The latex of the commercial rubber tree, Hevea brasiliensis, was fractionated by ultracentrifugation as described by G. F. J. Moir ([1959] Nature 184: 1626-1628) into a top layer of rubber particles, a cleared cytoplasm, and a pellet that contains primarily specialized vacuoles known as lutoids. The proteins in each fraction were resolved by two-dimensional gel electrophoresis. Both the pellet fraction and cleared cytoplasm contained large amounts of relatively few proteins, suggesting that laticifers serve a very specialized function in the plant. More than 75% of the total soluble protein in latex was found in the pellet fraction. Twenty-five percent of the protein in the pellet was identified as chitinases/lysozymes, which are capable of degrading the chitin component of fungal cell walls and the peptidoglycan component of bacterial cell walls. Both the chitinase and lysozyme activities were localized exclusively in the pellet or lutoid fraction. The chitinases/lysozymes were resolved into acidic and basic classes of proteins and further purified. An acidic protein (molecular mass 25.5 kD) represented 20% of the chitinase activity in latex; this protein lacked the low level of lysozyme activity that is associated with many plant chitinases. Six basic proteins, having both chitinase and lysozyme activities in various ratios and molecular mass of 27.5 or 26 kD, were resolved. Two of the basic proteins had very high lysozyme specific activities which were comparable to the specific activities reported for animal lysozymes. Like animal lysozymes, but unlike previously characterized plant chitinases/lysozymes, these basic chitinases/lysozymes were also capable of completely lysing or clearing suspensions of bacterial cell walls. These results suggest that laticifers may serve a defensive role in the plant. Images Figure 2 Figure 5

Martin, Melinda N.

1991-01-01

322

Genetic variation and migration in the Mexican free-tailed bat (Tadarida brasiliensis mexicana).  

PubMed

Incomplete lineage sorting can genetically link populations long after they have diverged, and will exert a more powerful influence on larger populations. The effects of this stochastic process can easily be confounded with those of gene flow, potentially leading to inaccurate estimates of dispersal capabilities or erroneous designation of evolutionarily significant units (ESUs). We have used phylogenetic, population genetic, and coalescent methods to examine genetic structuring in large populations of a widely dispersing bat species and to test hypotheses concerning the influences of coalescent stochasticity vs. gene flow. The Mexican free-tailed bat, Tadarida brasiliensis mexicana, exhibits variation in both migratory tendency and route over its range. Observations of the species' migratory behaviour have led to the description of behaviourally and geographically defined migratory groups, with the prediction that these groups compose structured gene pools. Here, we used mtDNA sequence analyses coupled with existing information from allozyme, banding, and natural history studies to evaluate hypotheses regarding the relationship between migration and genetic structure. Analyses of molecular variance revealed no significant genetic structuring of behaviourally distinct migratory groups. Demographic analyses were consistent with population growth, although the timing of population expansion events differs between migratory and nonmigratory populations. Hypotheses concerning the role of gene flow vs. incomplete lineage sorting on these data are explored using coalescent simulations. Our study demonstrates the importance of accounting for coalescent stochasticity in formulating phylogeographical hypotheses, and indicates that analyses that do not take such processes into account can lead to false conclusions regarding a species' phylogeographical history. PMID:15910338

Russell, A L; Medellín, R A; McCracken, G F

2005-06-01

323

Serotonergic innervation of the auditory brainstem of the Mexican free-tailed bat, Tadarida brasiliensis.  

PubMed

Anatomical and electrophysiological evidence suggests that serotonin alters the processing of sound in the auditory brainstem of many mammalian species. The Mexican free-tailed bat is a hearing specialist, like other microchiropteran bats. At the same time, many aspects of its auditory brainstem are similar to those in other mammals. This dichotomy raises an interesting question regarding the serotonergic innervation of the bat auditory brainstem: Is the serotonergic input to the auditory brainstem similar in bats and other mammals, or are there specializations in the serotonergic innervation of bats that may be related to their exceptional hearing capabilities? To address this question, we immunocytochemically labeled serotonergic fibers in the brainstem of the Mexican free-tailed bat, Tadarida brasiliensis. We found many similarities in the pattern of serotonergic innervation of the auditory brainstem in Tadarida compared with other mammals, but we also found two striking differences. Similarities to staining patterns in other mammals included a higher density of serotonergic fibers in the dorsal cochlear nucleus and in granule cell regions than in the ventral cochlear nucleus, a high density of fibers in some periolivary nuclei of the superior olive, and a higher density of fibers in peripheral regions of the inferior colliculus compared with its core. The two novel features of serotonergic innervation in Tadarida were a high density of fibers in the fusiform layer of the dorsal cochlear nucleus relative to surrounding layers and a relatively high density of serotonergic fibers in the low-frequency regions of the lateral and medial superior olive. PMID:11370012

Hurley, L M; Thompson, A M

2001-06-18

324

Cytokine mRNA expression profiles in rats infected with the intestinal nematode Nippostrongylus brasiliensis.  

PubMed Central

Although the immune responses to intestinal nematode infection have been well studied and have been shown to be strongly driven by Th2-associated cytokines in mice, such information has been limited with respect to rats. We investigated changes in levels of the mRNAs encoding interleukin-2 (IL-2), IL-3, IL-4, IL-5, IL-10, and gamma interferon in the mesenteric lymph nodes of rats infected with Nippostrongylus brasiliensis by reverse transcription-PCR in comparison with immunoglobulin E (IgE)/IgG2a antibody, eosinophil, basophil, and mucosal mast cell responses. In the two rat strains used, Brown Norway and Fischer-344, which show different responses to allergens, serum IgE increased to much higher levels in the former than in the latter 2 weeks after infection. Intestinal mastocytosis was observed much earlier and more intensely in Brown Norway rats than in Fischer-344 rats, but the degrees of peripheral eosinophilia and basophilia did not differ between the two strains. In both strains, IL-3, IL-4, and IL-5 mRNA expression increased and peaked around 7 to 14 days after infection, while expression of IL-2, IL-10, and gamma interferon mRNAs did not change notably throughout the experimental period. The highest IL-4 mRNA expression was observed slightly earlier in Brown Norway than in Fischer-344 rats, but levels of IL-3 and IL-5 mRNAs peaked synchronously in both strains. The amounts of mRNAs encoding these three cytokines were always higher in Brown Norway than in Fischer-344 rats. It is suggested that in rats, Th2 or Th2-like cells are also induced after nematode infection, and IgE elevation is mainly related to increased IL-4 gene expression.

Matsuda, S; Uchikawa, R; Yamada, M; Arizono, N

1995-01-01

325

Protein selection using yeast surface display.  

PubMed

Binding proteins are typically isolated from combinatorial libraries of scaffold proteins using one of the many library screening tools available, such as phage display, yeast surface display or mRNA display. A key principle underlying these screening technologies is the establishment of a link between each unique mutant protein and its corresponding genetic code. The mutant proteins binding a desired target species are separated and subsequently identified using the genetic code. In this review, we largely focus on the use of yeast surface display for the isolation of binding proteins from combinatorial libraries. In yeast surface display, the yeast cell links the mutant protein to its coding DNA. Each yeast cell expresses the mutant proteins as fusions to a yeast cell wall protein; the yeast cell also carries plasmid DNA that codes for the mutant protein. Over the years, the yeast surface display platform has emerged as a powerful tool for protein engineering, and has been used in a variety of applications including affinity maturation, epitope mapping and biophysical characterization of proteins. Here we present a broad overview of the yeast surface display system and its applications, and compare it with other contemporary screening platforms. Further, we present detailed protocols for the use of yeast surface display to isolate de novo binding proteins from combinatorial libraries, and subsequent biophysical characterization of binders. These protocols can also be easily modified for affinity maturation of the isolated de novo binders. PMID:22465794

Gera, Nimish; Hussain, Mahmud; Rao, Balaji M

2012-03-23

326

Transformation systems of non-Saccharomyces yeasts.  

PubMed

This review describes the transformation systems including vectors, replicons, genetic markers, transformation methods, vector stability, and copy numbers of 13 genera and 31 species of non-Saccharomyces yeasts. Schizosaccharomyces pombe was the first non-Saccharomyces yeast studied for transformation and genetics. The replicons of non-Saccharomyces yeast vectors are from native plasmids, chromosomal DNA, and mitochondrial DNA of Saccharomyces cerevisiae, non-Saccharomyces yeasts, protozoan, plant, and animal. Vectors such as YAC, YCp, YEp, YIp, and YRp were developed for non-Saccharomyces yeasts. Forty-two types of genes from bacteria, yeasts, fungi, and plant were used as genetic markers that could be classified into biosynthetic, dominant, and colored groups to construct non-Saccharomyces yeasts vectors. The LEU2 gene and G418 resistance gene are the two most popular markers used in the yeast transformation. All known transformation methods such as spheroplast-mediating method, alkaline ion treatment method, electroporation, trans-kingdom conjugation, and biolistics have been developed successfully for non-Saccharomyces yeasts, among which the first three are most widely used. The highest copy number detected from non-Saccharomyces yeasts is 60 copies in Kluyveromyces lactis. No general rule is known to illustrate the transformation efficiency, vector stability, and copy number, although factors such as vector composition, host strain, transformation method, and selective pressure might influence them. PMID:11599715

Wang, T T; Choi, Y J; Lee, B H

2001-01-01

327

Oxidative stress responses in yeast  

Microsoft Academic Search

Yeast, and especially S. cerevisiae, is a unique eukaryotic model organism for studying oxidative stress and its cellular responses. S. cerevisiae has become a very powerful tool to decipher the complexity of these biologically important responses, because it offers the\\u000a relative simplicity of a single celled eukaryotic organism that enables the combination and integration of genetic, biochemical,\\u000a physico-chemical, cell biological,

Michel B. Toledano; Agnes Delaunay; Benoit Biteau; Daniel Spector; Dulce Azevedo

328

Characterization of the Yeast Transcriptome  

Microsoft Academic Search

We have analyzed the set of genes expressed from the yeast genome, herein called the transcriptome, using serial analysis of gene expression. Analysis of 60,633 transcripts revealed 4,665 genes, with expression levels ranging from 0.3 to over 200 transcripts per cell. Of these genes, 1981 had known functions, while 2684 were previously uncharacterized. The integration of positional information with gene

Victor E. Velculescu; Lin Zhang; Wei Zhou; Jacob Vogelstein; Munira A. Basrai; Douglas E Bassett; Phil Hieter; Bert Vogelstein; Kenneth W. Kinzler

1997-01-01

329

Yeast strains for concentrated substrates  

Microsoft Academic Search

Summary  The screening of twenty yeast strains for ethanol productivity at high osmotic pressure at temperatures ranging from 32C\\u000a to 45C is described. Shake flask fermentations of 30, 40, and 50 Bx cane molasses were performed. The effect of temperature\\u000a on productivity at a non-inhibitory ethanol level is weakly pronounced. Most strains fermented poorly at 50 Bx molasses but\\u000a two Schizosaccharomyces

Åke Haraldson; Torsten Björling

1981-01-01

330

Investigating Wild Yeast Baking Potentials  

Microsoft Academic Search

2 Abstract: Yeast strains isolated from locally brewed beverages (Burukutu and Palm Wine) was identified to be Saccharomyces cerevisiae. They were tested for markers characteristics such as sugars fermentation ability, growth at elevated temperatures, growth in 3.0% NaCl,3.0% ethanol and 50.0% glucose were found to b e identical with the standard strain of Saccharomyces cerevisiae characteristically. The two isolates compared

A. Yabaya; E. D. Jatau

2009-01-01

331

Rheologically interesting polysaccharides from yeasts  

Microsoft Academic Search

We have examined the relationships between primary, secondary, and tertiary structures of polysaccharides exhibiting the rheological\\u000a property of friction (drag) reduction in turbulent flows. We found an example of an exopolysaccharide from the yeastCryptococcus laurentii that possessed high molecular weight but exhibited lower than expected drag reducing activity. Earlier correlations by Hoyt\\u000a (8,10) showing that ?1 ? 3, ??4, and

Gene R. Petersen; Gregory A. Nelson; Cheryl A. Cathey; Gerald G. Fuller

1989-01-01

332

Yeast genomics on food flavours  

Microsoft Academic Search

The appearance and concentration of the fusel alcohol 3-methyl-1-butanol is important for the flavour of fermented foods. 3-Methyl-1-butanol is formed by yeast during the conversion of L-leucine. Identification of the enzymes and genes involved in the formation of 3-methyl-1-butanol is a major prerequisite to optimize and control the final food flavour. To identify genes involved in this metabolic route, cDNA

Sung Ah Schoondermark-Stolk

2005-01-01

333

Interaction Between Yeasts and Zinc  

Microsoft Academic Search

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a\\u000a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase.\\u000a The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard

Raffaele De Nicola; Graeme Walker

2009-01-01

334

Candida zeylanoides: Another Opportunistic Yeast  

Microsoft Academic Search

A patient witha longhistory ofscleroderma andgastrointestinal malabsorption requiring total parenteral nutrition was admitted withCandidazeylanoides fungemia. Theyeastresponded totherapy, buton two subsequent admissions forepisodes offeverthebloodcultures yielded thesame yeast.Theidentity ofthe Candida species was established biochemically byboththeAPI(Analytab) andViteksystemapproaches. C. zeylanoides ATCC20356andATCC7351served ascontrols forthese analyses andforantifungal susceptibility studies andrestriction endonuclease analyses ofchromosomal DNA. Theseinvestigations indicated that representative isolates oftheyeasts fromthethree episodes were identical anddiffered inseveral

DAVID LEVENSON; MICHAEL A. PFALLER; MIRIAM A. SMITH; RICHARD HOLLIS; TIM GERARDEN; CONNIE B. TUCCI; HENRY D. ISENBERG

1991-01-01

335

Thermoregulation during flight: body temperature and sensible heat transfer in free-ranging Brazilian free-tailed bats (Tadarida brasiliensis).  

PubMed

Bat wings are important for thermoregulation, but their role in heat balance during flight is largely unknown. More than 80% of the energy consumed during flight generates heat as a by-product, and thus it is expected that bat wings should dissipate large amounts of heat to prevent hyperthermia. We measured rectal (T(r)) and surface (T(s)) temperatures of Brazilian free-tailed bats (Tadarida brasiliensis) as they emerged from and returned to their daytime roosts and calculated sensible heat transfer for different body regions (head, body, wings, and tail membrane). Bats' T(r) decreased from 36.8°C during emergence flights to 34.4°C during returns, and T(s) scaled positively with ambient temperature (T(a)). Total radiative heat loss from bats was significantly greater for a radiative sink to the night sky than for a sink with temperature equal to T(a). We found that free-ranging Brazilian free-tailed bats, on average, do not dissipate heat from their wings by convection but instead dissipate radiative heat (L) to the cloudless night sky during flight ([Formula: see text] W). However, within the range of T(a) measured in this study, T. brasiliensis experienced net heat loss between evening emergence and return flights. Regional hypothermia reduces heat loss from wings that are exposed to potentially high convective fluxes. Additional research is needed to establish the role of wings in evaporative cooling during flight in bats. PMID:21034204

Reichard, Jonathan D; Fellows, Spenser R; Frank, Alexander J; Kunz, Thomas H

2010-10-29

336

Desulfovibrio brasiliensis sp. nov., a moderate halophilic sulfate-reducing bacterium from Lagoa Vermelha (Brazil) mediating dolomite formation.  

PubMed

A novel halotolerant sulfate-reducing bacterium, Desulfovibrio brasiliensis strain LVform1, was isolated from sediments of a dolomite-forming hypersaline coastal lagoon, Lagoa Vermelha, in the state of Rio de Janeiro, Brazil. The cells are vibrio-shaped and 0.30 to 0.45 microm by 1.0 to 3.5 microm in size. These bacteria mediate the precipitation of dolomite [CaMg(CO3)2] in culture experiments. The strain was identified as a member of the genus Desulfovibrio in the delta-subclass of the Proteobacteria on the basis of its 16S rRNA gene sequence, its physiological and morphological properties. Strain LVform1 is obligate sodium-dependent and grows at NaCl concentrations of up to 15%. The 16S rRNA sequence revealed that this strain is closely related to Desulfovibrio halophilus (96.2% similarity) and to Desulfovibrio oxyclinae (96.8% similarity), which were both isolated from Solar Lake, a hypersaline coastal lake in the Sinai, Egypt. Strain LVform1 is barotolerant, growing under pressures of up to 370 bar (37 MPa). We propose strain LVform1 to be the type strain of a novel species of the genus Desulfovibrio, Desulfovibrio brasiliensis (type strain LVform1 = DSMZ No. 15816 and JCM No. 12178). The GenBank/EMBL accession number for the 16S rDNA sequence of strain LVform1 is AJ544687. PMID:15856133

Warthmann, Rolf; Vasconcelos, Crisogono; Sass, Henrik; McKenzie, Judith A

2005-04-26

337

Macrophage activation-mediated hydrogen peroxide generation by the royal sun medicinal mushroom Agaricus brasiliensis (Higher Basidiomycetes).  

PubMed

Agaricus brasiliensis has been demonstrated to have potent antitumor activity. The activity is postulated to act through mediation of the host immune system. We have reported that A. brasiliensis extract (ABE) inhibited compound 48/80 induced a systemic anaphylaxis-like reaction, ear swelling response, and passive cutaneous anaphylaxis-like reaction in mice. There is some recent information available on the mechanism of antiallergic effects resulting from oral administration of ABE. However, information regarding how ABE may activate macrophages through intestinal epithelial cells is still limited. To clarify the mechanism of macrophages activation by ABE, a gut in vitro model constructed of Caco-2 and RAW264.7 cells was applied. Treatment of ABE to the apical compartment resulted in significant increases in tumor necrosis factor (TNF)-? production in the basolateral compartment. Moreover, addition of catalase to the basolateral compartment before ABE treatment suppressed TNF-? production completely, but the addition of superoxide dismutase did not suppress this at all. These data suggest that ABE could potentiate hydrogen peroxide emissions from Caco-2 cells into the basolateral side and activate macrophages, which is important in the immune system. PMID:23796218

Mizuno, Masashi; Nishitani, Yosuke

2013-01-01

338

EXTRALIMITAL RECORDS OF THE MEXICAN FREE-TAILED BAT (TADARIDA BRASILIENSIS MEXICANA) IN THE CENTRAL UNITED STATES AND THEIR BIOLOGICAL SIGNIFICANCE  

Microsoft Academic Search

Two new records of Tadarida brasiliensis mexicana are reported from Nebraska. The literature records of this taxon from the central United States are summarized. In this region of North America, these bats occupy a “natal range” where the species carries on regular reproductive activities and the populations are relatively stable, including California, Arizona, New Mexico, Texas, and Oklahoma. To the

Hugh H. Genoways; Patricia W. Freeman; Cary Grell

2000-01-01

339

Emerging applications of the methylotrophic yeasts.  

PubMed

The use of methylotrophic yeasts for the production of single-cell-protein (SCP), alcohol oxidase and fine chemicals has been proposed. Fermentation technology developed for the growth of these yeasts on methanol at high cell densities has been commercialized. However, it is the production of heterologous recombinant proteins by Pichia pastoris that is emerging as the most significant application of the methylotrophic yeasts. PMID:2094288

Wegner, G H

1990-12-01

340

Yeasts in floral nectar: a quantitative survey  

PubMed Central

Background and Aims One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored. Methods The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated. Key Results Yeasts occurred regularly in the floral nectar of many species, where they sometimes reached extraordinary densities (up to 4 × 105 cells mm?3). Depending on the region, between 32 and 44 % of all nectar samples contained yeasts. Yeast cell densities in the order of 104 cells mm?3 were commonplace, and densities >105 cells mm?3 were not rare. About one-fifth of species at each site had mean yeast cell densities >104 cells mm?3. Across species, yeast frequency and abundance were directly correlated with the proportion of floral visits by bumble-bees, and inversely with the proportion of visits by solitary bees. Conclusions Incorporating nectar yeasts into the scenario of plant–pollinator interactions opens up a number of intriguing avenues for research. In addition, with yeasts being as ubiquitous and abundant in floral nectars as revealed by this study, and given their astounding metabolic versatility, studies focusing on nectar chemical features should carefully control for the presence of yeasts in nectar samples.

Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, Maria I.

2009-01-01

341

Production of ethanol by immobilized yeast cells  

Microsoft Academic Search

Saccharomyces cerevisiae cells were immobilized in calcium alginate beads for use in the continuous production of ethanol. Yeasts were grown in medium supplemented with ethanol to selectively screen for a culture which showed the greatest tolerance to ethanol inhibition. Yeast beads were produced from a yeast slurry containing 1.5% alginate (w\\/v) which was added as drops to a 0.05M CaCl2

David Williams; Douglas M. Munnecke

1981-01-01

342

Evaluation of Kluyveromyces marxianus as baker's yeast  

Microsoft Academic Search

Two strains of Kluyveromyces marxianus (NRRL-Y-2415 and NRRL-Y-1109) were assessed as baker's yeasts comparing them with two strains of Saccharomyces cerevisiae isolated respectively from compressed yeast and active dry yeast. Strains were tested for dough proofing activity in lean dough and rich doughs (prepared with sucrose, lactose or whey) and sensory evaluation of breads. In rich doughs containing lactose or

R. Caballero; P. Olguín; A. Cruz-Guerrero; F. Gallardo; M. García-Garibay; L. Gómez-Ruiz

1995-01-01

343

Yeast production from virgin grape marc  

Microsoft Academic Search

An alternative utilization of virgin grape marc (VGM) to produce SCP from S. cerevisiae is reported. A simple extraction method of fresh grape marc produces a sugar-rich solution; through fed-batch fermentation, a high-value yeast biomass instead of a low-value product like ethanol can be produced.Productivity and quality of yeast are similar to these obtainable from molasses. The convenience of yeast

R. B. Lo Curto; M. M. Tripodo

2001-01-01

344

Cell fusion assays for yeast mating pairs.  

PubMed

Yeast mating provides an accessible genetic system for the discovery of fundamental mechanisms in eukaryotic cell fusion. Although aspects of yeast mating related to pheromone signaling and polarized growth have been intensively investigated, fusion itself is poorly understood. This chapter describes methods for measuring the overall efficiency of yeast cell fusion and for monitoring various stages of the fusion process including cell wall remodeling, plasma membrane fusion, and nuclear fusion. PMID:18979244

Grote, Eric

2008-01-01

345

The yeast Golgi apparatus: insights and mysteries  

PubMed Central

The Golgi apparatus is known to modify and sort newly synthesized secretory proteins. However, fundamental mysteries remain about the structure, operation, and dynamics of this organelle. Important insights have emerged from studying the Golgi in yeasts. For example, yeasts have provided direct evidence for Golgi cisternal maturation, a mechanism that is likely to be broadly conserved. Here, we highlight features of the yeast Golgi as well as challenges that lie ahead.

Papanikou, Effrosyni; Glick, Benjamin S.

2009-01-01

346

High-Frequency Transformation of Yeast by Plasmids Containing the Cloned Yeast ARG4 Gene  

Microsoft Academic Search

Hybrid ColE1 plasmids, containing cloned DNA from the yeast ARG4 region [e.g., pYe(arg4)1], transform yeast arg4 mutants to ARG4+ with a frequency of 10-4 (about 103 transformants per mu g of plasmid DNA) and can replicate autonomously without integrating into the yeast genome. The yeast transformants are genetically unstable when grown on nonselective medium, but can be readily grown and

Chu-Lai Hsiao; John Carbon

1979-01-01

347

Rapid urea broth test for yeasts.  

PubMed Central

A rapid, miniaturized, urea broth test useful for detecting urease activity of yeasts was compared to Christensen urea agar. All urease-producing yeasts tested were positive on both media; however, 60% were reactive in the urea R broth within 30 min, and the remainder were reactive within 4 h. This urea multiwell test may be useful as a rapid screening method for detecting urease-producing yeasts recovered from clinical specimens and as an adjunct test with other rapid methods of yeast identification. Images

Roberts, G D; Horstmeier, C D; Land, G A; Foxworth, J H

1978-01-01

348

Lessons on longevity from budding yeast.  

PubMed

The past decade has seen fundamental advances in our understanding of the ageing process and raised optimism that interventions to slow ageing may be on the horizon. Studies of budding yeast have made immense contributions to this progress. Yeast longevity factors have now been shown to modulate ageing in invertebrate and mammalian models, and studies of yeast have resulted in some of the best candidates for anti-ageing drugs currently in development. The first interventions to slow human ageing may spring from the humble yeast. PMID:20336133

Kaeberlein, Matt

2010-03-25

349

Presence of glucosylceramide in yeast and its relation to alkali tolerance of yeast  

Microsoft Academic Search

Glycosylceramide is a membrane lipid that has physiological functions in eukaryotic organisms. The presence of glucosylceramide has been confirmed in some yeast; however, the extent of the role of glucosylceramide in yeast is unknown. Thus, the extent of presence of glucosylceramide in yeast was surveyed using 90 strains of 24 genera. The strains were divided into two groups according to

Katsuichi Saito; Naoya Takakuwa; Masao Ohnishi; Yuji Oda

2006-01-01

350

Characterisation of yeast microbial fuel cell with the yeast Arxula adeninivorans as the biocatalyst  

Microsoft Academic Search

Yeast microbial fuel cells have received little attention to date. Yeast should be ideal MFC catalyst because they are robust, easily handled, mostly non-pathogenic organisms with high catabolic rates and in some cases a broad substrate spectrum. Here we show that the non-conventional yeast Arxula adeninvorans transfers electrons to an electrode through the secretion of a reduced molecule that is

Nicholas D. Haslett; Frankie J. Rawson; Frèdèric Barriëre; Gotthard Kunze; Neil Pasco; Ravi Gooneratne; Keith H. R. Baronian

2011-01-01

351

Immunoenzymatic absorption test for serodiagnosis of paracoccidioidomycosis.  

PubMed Central

A sensitive enzyme-linked immunosorbent assay is described for paracoccidioidomycosis serodiagnosis, with antigen represented by filtrates from Paracoccidioides brasiliensis cultures. Cross-reactivities were, however, observed with sera from patients with other mycoses such as histoplasmosis, lobomycosis, cryptococcosis, candidiasis, and sporotrichosis. These cross-reactions did not occur when we used as antigen Yarzabal E2 component prepared by affinity fractionation of the culture filtrates. Specific results could also be obtained with the whole filtrate antigen when sera were absorbed with Histoplasma capsulatum yeast and mycelial components. Besides a very high sensitivity (100% of the 69 cases of paracoccidioidomycosis tested), this assay showed no false-positive results for the 206 non-paracoccidioidomycosis sera studied, including those from patients with other mycotic diseases. Images

Mendes-Giannini, M J; Camargo, M E; Lacaz, C S; Ferreira, A W

1984-01-01

352

Leishmanicidal, antiproteolytic and antioxidant evaluation of natural biflavonoids isolated from Garcinia brasiliensis and their semisynthetic derivatives.  

PubMed

The natural biflavonoids morelloflavone-4?-O-?-D-glycosyl (1), (±)-fukugiside (2) and morelloflavone (3) were isolated from the ethyl acetate extract (EAEE) of dried and powdered fruit epicarps of Garcinia brasiliensis and derivatives of morelloflavone were semi-synthesised. Morelloflavone-7,4',7?,3?,4?-penta-O-acetyl (4), morelloflavone-7,4',7?,3?,4?-penta-O-methyl (5) and morelloflavone-7,4',7?,3?,4?-penta-O-butanoyl (6) were prepared by acylation and alkylation reactions. All compounds showed leishmanicidal, antiproteolytic and antioxidant activities in addition to exhibiting low cytotoxicity. Compounds 4, 5 and 6 were highly active against Leishmania amazonensis promastigote forms compared to natural compounds of low lipophilicity, exhibiting IC(50) values of 0.0147, 0.0403 and 0.0189 ?M, respectively. Compounds 4, 5 and 6 were also highly active against amastigote forms with IC(50) values of 0.042, 0.0603 and 0.059 ?M, respectively. In addition, highly inhibitory activity against r-CPB2.8 and r-CPB3 isoforms was observed with these compounds. Notably, compounds 3 and 4 were the most active against r-CPB2.8 with IC(50) values of 0.4200 and 0.6744 ?M, respectively. Compounds 5 and 6 also showed significant inhibitory activities with very similar IC(50) values of 1.2663 and 1.0122, respectively. However, compounds 1 and 2 exhibited the lowest inhibitory activity against r-CPB2.8, almost 6 and 11-fold less active than the natural compound 3. In L. (L.) amazonensis lysates, and compounds 3 and 6 were the most active inhibitors of amastigote lysates at pH 5, which is near the pH environment of the parasitophorous vacuole within the macrophage. Finally, compounds 1, 2 and 3 exhibited effective antioxidant activity compared to the reference antioxidant ascorbic acid. However, the activity was lower than that of butylhydroxytoluene (BHT), which may be related to the reduced number of phenolic hydroxyl groups that were replaced by more lipophilic substituents in derivatives 4-6. Compounds 4-6 exhibited reduced antioxidant activity as evidenced by their higher EC(50) values. These results provide new perspectives on drug development for the treatment of leishmaniasis and inhibitory enzyme activity on Leishmania (L.) mexicana cysteine proteases and other isoforms. PMID:23178961

Gontijo, Vanessa Silva; Judice, Wagner A S; Codonho, Barbara; Pereira, Ivan Oliveira; Assis, Diego Magno; Januário, Jaqueline Pereira; Caroselli, Elide E; Juliano, Maria Aparecida; de Carvalho Dosatti, Amanda; Marques, Marcos José; Viegas Junior, Claudio; Henrique dos Santos, Marcelo

2012-06-28

353

Functional interaction of yeast elongation factor 3 with yeast ribosomes.  

PubMed

Elongation factor 3 (EF-3) is a unique and essential requirement of the fungal translational apparatus. EF-3 is a monomeric protein with a molecular mass of 116,000. EF-3 is required by yeast ribosomes for in vitro translation and for in vivo growth. The protein stimulates the binding of EF-1 alpha :GTP:aa-tRNA ternary complex to the ribosomal A-site by facilitating release of deacylated-tRNA from the E-site. The reaction requires ATP hydrolysis. EF-3 contains two ATP-binding sequence motifs (NBS). NBSI is sufficient for the intrinsic ATPase function. NBSII is essential for ribosome-stimulated activity. By limited proteolysis, EF-3 was divided into two distinct functional domains. The N-terminal domain lacking the highly charged lysine blocks failed to bind ribosomes and was inactive in the ribosome-stimulated ATPase activity. The C-terminally derived lysine-rich fragment showed strong binding to yeast ribosomes. The purported S5 homology region of EF-3 at the N-terminal end has been reported to interact with 18S ribosomal RNA. We postulate that EF-3 contacts rRNA and/or protein(s) through the C-terminal end. Removal of these residues severely weakens its interaction mediated possibly through the N-terminal domain of the protein. PMID:10216951

Chakraburtty, K

1999-01-01

354

Spoilage yeasts in the wine industry.  

PubMed

Yeasts play a central role in the spoilage of foods and beverages, mainly those with high acidity and reduced water activity (a(w)). A few species are capable of spoiling foods produced according to good manufacturing practices (GMPs). These can survive and grow under stress conditions where other microorganisms are not competitive. However, many of the aspects determining yeast spoilage have yet to be clarified. This critical review uses the wine industry as a case study where serious microbiological problems are caused by yeasts. First, the limitations of the available tools to assess the presence of spoilage yeasts in foods are discussed. Next, yeasts and factors promoting their colonisation in grapes and wines are discussed from the ecological perspective, demonstrating that a deeper knowledge of vineyard and winery ecosystems is essential to establish the origin of wine spoilage yeasts, their routes of contamination, critical points of yeast infection, and of course, their control. Further, zymological indicators are discussed as important tools to assess the microbiological quality of wines, although they are rarely used by the wine industry. The concepts of the susceptibility of wine to spoilage yeasts and wine stability are addressed based on scientific knowledge and industrial practices for monitoring yeast contamination. A discussion on acceptable levels of yeasts and microbiological criteria in the wine industry is supported by data obtained from wineries, wholesalers, and the scientific literature.Finally, future directions for applied research are proposed, involving collaboration between scientists and industry to improve the quality of wine and methods for monitoring the presence of yeast. PMID:12892920

Loureiro, V; Malfeito-Ferreira, M

2003-09-01

355

Experimental evolution in budding yeast  

NASA Astrophysics Data System (ADS)

I will discuss our progress in analyzing evolution in the budding yeast, Saccharomyces cerevisiae. We take two basic approaches. The first is to try and examine quantitative aspects of evolution, for example by determining how the rate of evolution depends on the mutation rate and the population size or asking whether the rate of mutation is uniform throughout the genome. The second is to try to evolve qualitatively novel, cell biologically interesting phenotypes and track the mutations that are responsible for the phenotype. Our efforts include trying to alter cell morphology, evolve multicellularity, and produce a biological oscillator.

Murray, Andrew

2012-02-01

356

Functional analysis of the yeast genome  

Microsoft Academic Search

The release of the complete genome sequence of the yeast Saccharomyces cerevisiae has ushered in a new phase of genome research in which sequence function will be assigned. The goal is to determine the biological function of each of the >6,000 open reading frames in the yeast genome. Innovative approaches have been developed that exploit the sequence data and yield

Elizabeth A Winzeler; Ronald W Davist

1997-01-01

357

3 Baker's yeast: challenges and future prospects  

Microsoft Academic Search

In the past few years, recombinant DNA technology has led to the apparition of new baker's yeast strains, which have optimized or novel properties, and in the near future, it is expected that this tool will produce a huge spectrum of specialized yeasts of high added value. Their introduction in the manufacturing market will produce a dramatic Change in formulation,

Francisca Randez-Gil; Jaime Aguilera; Antonio Codón; Ana M. Rincón; Francisco Estruch; José A. Prieto

358

Characterization of wine yeasts for ethanol production  

Microsoft Academic Search

Selected wine yeasts were tested for their ethanol and sugar tolerance, and for their fermentative capacity. Growth (µ) and fermentation rates (?) were increasingly inhibited by increasing ethanol and glucose concentrations, “flor” yeasts being the least inhibited. Except in the latter strains, the ethanol production rate was accelerated by adding the glucose stepwise. The best fermenting strains selected in laboratory

Juan Jiménez; Tahía Benítez

1986-01-01

359

Characterization of wine yeasts for ethanol production  

Microsoft Academic Search

Summary Selected wine yeasts were tested for their ethanol and sugar tolerance, and for their fermentative capacity. Growth (µ) and fermentation rates (?) were increasingly inhibited by increasing ethanol and glucose concentrations, “flor” yeasts being the least inhibited. Except in the latter strains, the ethanol production rate was accelerated by adding the glucose stepwise. The best fermenting strains selected in

Juan Jiménez; Tahía Benítez

1986-01-01

360

Yeast: An Experimental Organism for Modern Biology.  

ERIC Educational Resources Information Center

|Discusses the applicability and advantages of using yeasts as popular and ideal model systems for studying and understanding eukaryotic biology at the cellular and molecular levels. Cites experimental tractability and the cooperative tradition of the research community of yeast biologists as reasons for this success. (RT)|

Botstein, David; Fink, Gerald R.

1988-01-01

361

TAXONOMY AND PHYLOGENETIC DIVERSITY AMONG THE YEASTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Yeasts are fungi that predominantly exist as unicellular organisms. However, some yeasts can become multicellular through formation of strands of elongated buds known as pseudohyphae, or through the formation of true hyphae that have well developed crosswalls like those seen in typical filamentous ...

362

The oenological characteristics of commercial dry yeasts  

Microsoft Academic Search

Twenty preparations of dry active yeast (18 Saccharomyces cerevisiae and two Saccharomyces bayanus) available in Italy were tested in white and red musts (Moscato, Albana and Sangiovese) to study their oenological characteristics (i.e. fermentation rate, total alcohol and acetic acid production). After the application of chemiometric techniques for descriptive analyses to the results of the oenological assessment, the yeasts were

Giuseppe Comi; Isabella Croattini; Marilena Marino; Michela Maifreni; Roberto Zironi

1997-01-01

363

Oily yeasts as oleaginous cell factories.  

PubMed

Oily yeasts have been described to be able to accumulate lipids up to 20% of their cellular dry weight. These yeasts represent a minor proportion of the total yeast population, and only 5% of them have been reported as able to accumulate more than 25% of lipids. The oily yeast genera include Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces. More specifically, examples of oleaginous yeasts include the species: Lipomyces starkeyi, Rhodosporidium toruloides, Rhodotorula glutinis, and Yarrowia lipolytica. Yeast do exhibit advantages for lipid production over other microbial sources, namely, their duplication times are usually lower than 1 h, are much less affected than plants by season or climate conditions, and their cultures are more easily scaled up than those of microalgae. Additionally, some oily yeasts have been reported to accumulate oil up to 80% of their dry weight and can indeed generate different lipids from different carbon sources or from lipids present in the culture media. Thus, they can vary their lipid composition by replacing the fatty acids present in their triglycerides. Due to the diversity of microorganisms and growth conditions, oily yeasts can be useful for the production of triglycerides, surfactants, or polyunsaturated fatty acids. PMID:21465305

Ageitos, Jose Manuel; Vallejo, Juan Andres; Veiga-Crespo, Patricia; Villa, Tomas G

2011-04-05

364

Protein Function, Connectivity, and Duplicability in Yeast  

Microsoft Academic Search

Protein-protein interaction networks have evolved mainly through connectivity rewiring and gene duplication. However, how protein function influences these processes and how a network grows in time have not been well studied. Using protein-protein interaction data and genomic data from the budding yeast, we first examined whether there is a correlation between the age and connectivity of yeast proteins. A steady

Anuphap Prachumwat; Wen-Hsiung Li

2005-01-01

365

Production of recombinant proteins by yeast cells  

Microsoft Academic Search

Yeasts are widely used in production of recombinant proteins of medical or industrial interest. For each individual product, the most suitable expression system has to be identified and optimized, both on the genetic and fermentative level, by taking into account the properties of the product, the organism and the expression cassette. There is a wide range of important yeast expression

Eda Çelik; P?nar Çal?k

366

CYGD: the Comprehensive Yeast Genome Database  

Microsoft Academic Search

The Comprehensive Yeast Genome Database (CYGD) compiles a comprehensive data resource for information on the cellular functions of the yeast Saccharomyces cerevisiae and related species, cho- sen as the best understood model organism for eukar- yotes. The database serves as a common resource generated by a European consortium, going beyond the provision of sequence information and functional annotations on individual

Ulrich Güldener; Martin Münsterkötter; Gabi Kastenmüller; Normann Strack; Jacques Van Helden; Christian Lemer; J. Richelles; Shoshana J. Wodak; J. García-martínez; J. E. Pérez-ortín; Holger Michael; Andreas Kaps; E. Talla; Bernard Dujon; B. André; J. L. Souciet; J. De Montigny; E. Bon; C. Gaillardin; Hans-werner Mewes

2005-01-01

367

Growth Requirements of San Francisco Sour Dough Yeasts and Bakers' Yeast  

PubMed Central

The growth requirements of several yeasts isolated from San Francisco sour dough mother sponges were compared with those of bakers' yeast. The sour dough yeasts studied were one strain of Saccharomyces uvarum, one strain of S. inusitatus, and four strains of S. exiguus. S. inusitatus was the only yeast found to have an amino acid requirement, namely, methionine. All of the yeasts had an absolute requirement for pantothenic acid and a partial requirement for biotin. Inositol was stimulatory to all except bakers' yeast. All strains of S. exiguus required niacin and thiamine. Interestingly, S. inusitatus, the only yeast that required methionine, also needed folic acid. For optimal growth of S. exiguus in a molasses medium, supplementation with thiamine was required.

Henry, NG

1976-01-01

368

Anhydrobiosis in yeast: influence of calcium and magnesium ions on yeast resistance to dehydration-rehydration.  

PubMed

The influence of calcium and magnesium ions on resistance to dehydration in the yeast, Saccharomyces cerevisiae, was investigated. Magnesium ion availability directly influenced yeast cells' resistance to dehydration and, when additionally supplemented with calcium ions, this provided further significant increase of yeast resistance to dehydration. Gradual rehydration of dry yeast cells in water vapour indicated that both magnesium and calcium may be important for the stabilization of yeast cell membranes. In particular, calcium ions were shown for the first time to increase the resistance of yeast cells to dehydration in stress-sensitive cultures from exponential growth phases. It is concluded that magnesium and calcium ion supplementations in nutrient media may increase the dehydration stress tolerance of S. cerevisiae cells significantly, and this finding is important for the production of active dry yeast preparations for food and fermentation industries. PMID:20487021

Trofimova, Yuliya; Walker, Graeme; Rapoport, Alexander

2010-04-14

369

Ultrastructural organization of yeast chromatin  

PubMed Central

The ultrastructural organization of yeast chromatin was examined in Miller spread preparations of samples prepared from spheroplasts or isolated nuclei of Saccharomyces cerevisiae. Micrographs from preparations dispersed in 1 mM Tris (pH 7.2) illustrate that the basic chromatin fiber in yeast exists in two ultrastructurally distinct conformations. The majority (up to 95%) of the chromatin displays a beaded nucleosomal organization, although adjacent nucleosomes are separated by internucleosomal linkers of variable lengths. Ribonucleoprotein (RNP) fibrils are only occasionally associated with chromatin displaying the conformation. The remaining 5-10% of the chromatin appears to be devoid of discrete nucleosomes and has a smooth contour with a fiber diameter of 30-40 A. Transcriptional units, including putative ribosomal precursor RNA genes, defined by the presence of nascent RNP fibrils are restricted to chromatin displaying this smooth morphology. Chromatin released from nuclei in the presence of 5 mM Mg++ displays higher-order chromatin fibers, 200-300 A in diameter, these fibers appear to be arranged in a manner than reflects the two forms of the basic chromatin fiber.

1982-01-01

370

Yeast community survey in the Tagus estuary.  

PubMed

The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity of the community. The occurrence of some yeasts was partially correlated with faecal pollution indicators. Yeast isolates were characterized by microsatellite primed PCR (MSP-PCR) fingerprinting and rRNA gene sequencing. The principal species found were Candida catenulata, C. intermedia, C. parapsilosis, Clavispora lusitaniae, Debaryomyces hansenii, Pichia guilliermondii, Rhodotorula mucilaginosa and Rhodosporidium diobovatum. The incidence of these species was evaluated against the environmental context of the samples and the current knowledge about the substrates from which they are usually isolated. PMID:16329949

de Almeida, João M G C F

2005-07-01

371

Yeasts and yeast-like fungi associated with tree bark: diversity and identification of yeasts producing extracellular endoxylanases.  

PubMed

A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam forest areas of Andhra Pradesh, India. Based on analysis of D1/D2 domain sequence of 26S rRNA gene, 114 strains were identified as ascomycetous; 107 strains were identified as basidiomycetous yeasts; and 18 strains were identified as yeast-like fungi. Among the ascomycetous yeasts, 51% were identified as members of the genus Pichia, and the remaining 49% included species belonging to the genera Clavispora, Debaryomyces, Kluyveromyces, Hanseniaspora, Issatchenkia, Lodderomyces, Kodamaea, Metschnikowia, and Torulaspora. The predominant genera in the basidiomycetous yeasts were Cryptococcus (48.6%), Rhodotorula (29%), and Rhodosporidium (12.1%). The yeast-like fungi were represented by Aureobasidium pullulans (6.7%) and Lecythophora hoffmanii (0.8%). Of the 239 yeast strains tested for Xylanase, only five strains of Aureobasidium sp. produced xylanase on xylan-agar medium. Matrix-assisted laser desorption ionization-time of flight analysis and N-terminal amino-acid sequence of the xylanase of isolate YS67 showed high similarity with endo-1-4-beta-xylanase (EC 3.2.1.8) of Aureobasidium pullulans var. melanigenum. PMID:18219522

Bhadra, Bhaskar; Rao, R Sreenivas; Singh, Pavan K; Sarkar, Partha K; Shivaji, Sisinthy

2008-01-25

372

Functional characterization of mast cells generated in vitro from the mesenteric lymph node of rats infected with Nippostrongylus brasiliensis.  

PubMed Central

We have examined the biochemical and functional characteristics of mast cells grown in tissue culture from the mesenteric lymph node (MLN) of rats infected with the nematode Nippostrongylus brasiliensis and compared them with mast cells isolated from the small intestinal mucosa and peritoneal cavity of infected animals. Cultured mast cells (MC) and isolated intestinal mucosal mast cells (MMC) had a similar histamine content, and both contained type II protease (RMCP II) which was absent from peritoneal mast cells (PMC). PMC, MMC and cultured MC each responded to immunologically induced histamine secretion, but MMC and cultured MC were hyporesponsive to calcium ionophores and unresponsive to widely used PMC secretagogues including compound 48/80 and bee venom peptide 401. MMC and cultured MC also differed from PMC in their lack of responsiveness to the anti-allergic agent disodium cromoglycate. Thus, MC cultured from the MLN are distinct from PMC but have a biochemical and functional phenotype similar to that of intestinal MMC.

Shanahan, F; Lee, T D; Denburg, J A; Bienenstock, J; Befus, A D

1986-01-01

373

Early Activation by Ethylene of the Tonoplast H+-Pumping ATPase in the Latex from Hevea brasiliensis  

PubMed Central

The treatment of Hevea brasiliensis (rubber tree) bark by chloro-2-ethyl phosphonic acid (ethrel), an ethylene-producing compound, induces a significant increase in the tonoplast H+-translocating ATPase activity in the latex during the first 24 hours after the application of the stimulating agent. Moreover, the tonoplast-bound ATPase is highly activated when vacuoles (lutoids) are resuspended in ultrafiltrated cytosol. This effect is amplified during ethrel stimulation. Preliminary assays to characterize the endogenous effector(s) suggest that the activator(s) could be a heat-resistant compound with a low molecular weight, most likely an anion. The activation of the tonoplast-bound ATPase and the associated activation of the protons translocation across the lutoid membrane, could explain the cytosolic alkalinization observed in latex following the ethrel treatment of Hevea bark, which results in an enhanced rubber production.

Gidrol, Xavier; Chrestin, Herve; Mounoury, Gilles; D'Auzac, Jean

1988-01-01

374

Early Activation by Ethylene of the Tonoplast H-Pumping ATPase in the Latex from Hevea brasiliensis.  

PubMed

The treatment of Hevea brasiliensis (rubber tree) bark by chloro-2-ethyl phosphonic acid (ethrel), an ethylene-producing compound, induces a significant increase in the tonoplast H(+)-translocating ATPase activity in the latex during the first 24 hours after the application of the stimulating agent. Moreover, the tonoplast-bound ATPase is highly activated when vacuoles (lutoids) are resuspended in ultrafiltrated cytosol. This effect is amplified during ethrel stimulation. Preliminary assays to characterize the endogenous effector(s) suggest that the activator(s) could be a heat-resistant compound with a low molecular weight, most likely an anion. The activation of the tonoplast-bound ATPase and the associated activation of the protons translocation across the lutoid membrane, could explain the cytosolic alkalinization observed in latex following the ethrel treatment of Hevea bark, which results in an enhanced rubber production. PMID:16666005

Gidrol, X; Chrestin, H; Mounoury, G; D'Auzac, J

1988-03-01

375

Ethylene-Induced Increase in Glutamine Synthetase Activity and mRNA Levels in Hevea brasiliensis Latex Cells.  

PubMed Central

Ethylene, used as a stimulant of latex production in Hevea brasiliensis, significantly activates the regenerating metabolism within the laticiferous cells. In this context, attention was focused on glutamine synthetase (GS; EC 6.3.1.2), a key enzyme in nitrogen metabolism. A specific and significant activation of the cytosolic glutamine synthetase (GScyt) in the laticiferous cells after ethylene treatment parallels the increase of latex yield. A marked accumulation of the corresponding mRNA was found, but in contrast, a slight and variable increase of the polypeptide level is at the limit of detection by western blotting. The GS response to ethylene might be mediated by ammonia that increases in latex cytosol following ethylene treatment. The physiological significance for such a regulation by ethylene of the GScyt is discussed in terms of the nitrogen requirement for protein synthesis associated with latex regeneration.

Pujade-Renaud, V.; Clement, A.; Perrot-Rechenmann, C.; Prevot, J. C.; Chrestin, H.; Jacob, J. L.; Guern, J.

1994-01-01

376

Inactivation of platelet-activating factor by a putative acetylhydrolase from the gastrointestinal nematode parasite Nippostrongylus brasiliensis.  

PubMed

The adult stage of Nippostrongylus brasiliensis, a strongyloid parasite of the gastrointestinal tract of rats, released a product during in vitro culture which functionally inhibited platelet-activating factor (PAF), measured by its ability to mediate platelet aggregation. The extent of inhibition was proportional to the concentration of excretory/secretory (ES) products and the duration of preincubation with PAF prior to the assay of biological activity. The inhibitory activity was heat labile and was specific for PAF, as incubation of ES products with thrombin showed no diminution of platelet aggregation. Experiments using radiolabelled preparations of PAF demonstrated that the acetyl group esterified at the sn-2 position of the glycerol backbone was liberated on incubation with ES products, indicative of an acetylhydrolase activity. This activity was susceptible to inhibition by DFP, partial inhibition by eserine, but was resistant to PMSF and TPCK at concentrations which inhibit serine proteases. PMID:1537601

Blackburn, C C; Selkirk, M E

1992-01-01

377

Inactivation of platelet-activating factor by a putative acetylhydrolase from the gastrointestinal nematode parasite Nippostrongylus brasiliensis.  

PubMed Central

The adult stage of Nippostrongylus brasiliensis, a strongyloid parasite of the gastrointestinal tract of rats, released a product during in vitro culture which functionally inhibited platelet-activating factor (PAF), measured by its ability to mediate platelet aggregation. The extent of inhibition was proportional to the concentration of excretory/secretory (ES) products and the duration of preincubation with PAF prior to the assay of biological activity. The inhibitory activity was heat labile and was specific for PAF, as incubation of ES products with thrombin showed no diminution of platelet aggregation. Experiments using radiolabelled preparations of PAF demonstrated that the acetyl group esterified at the sn-2 position of the glycerol backbone was liberated on incubation with ES products, indicative of an acetylhydrolase activity. This activity was susceptible to inhibition by DFP, partial inhibition by eserine, but was resistant to PMSF and TPCK at concentrations which inhibit serine proteases.

Blackburn, C C; Selkirk, M E

1992-01-01

378

Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensis and the evolution of secreted proteins in parasites  

PubMed Central

Background Parasitism is a highly successful mode of life and one that requires suites of gene adaptations to permit survival within a potentially hostile host. Among such adaptations is the secretion of proteins capable of modifying or manipulating the host environment. Nippostrongylus brasiliensis is a well-studied model nematode parasite of rodents, which secretes products known to modulate host immunity. Results Taking a genomic approach to characterize potential secreted products, we analyzed expressed sequence tag (EST) sequences for putative amino-terminal secretory signals. We sequenced ESTs from a cDNA library constructed by oligo-capping to select full-length cDNAs, as well as from conventional cDNA libraries. SignalP analysis was applied to predicted open reading frames, to identify potential signal peptides and anchors. Among 1,234 ESTs, 197 (~16%) contain predicted 5' signal sequences, with 176 classified as conventional signal peptides and 21 as signal anchors. ESTs cluster into 742 distinct genes, of which 135 (18%) bear predicted signal-sequence coding regions. Comparisons of clusters with homologs from Caenorhabditis elegans and more distantly related organisms reveal that the majority (65% at P < e-10) of signal peptide-bearing sequences from N. brasiliensis show no similarity to previously reported genes, and less than 10% align to conserved genes recorded outside the phylum Nematoda. Of all novel sequences identified, 32% contained predicted signal peptides, whereas this was the case for only 3.4% of conserved genes with sequence homologies beyond the Nematoda. Conclusions These results indicate that secreted proteins may be undergoing accelerated evolution, either because of relaxed functional constraints, or in response to stronger selective pressure from host immunity.

Harcus, Yvonne M; Parkinson, John; Fernandez, Cecilia; Daub, Jennifer; Selkirk, Murray E; Blaxter, Mark L; Maizels, Rick M

2004-01-01

379

In vivo anti-herpes simplex virus activity of a sulfated derivative of Agaricus brasiliensis mycelial polysaccharide.  

PubMed

Agaricus brasiliensis (syn. A. subrufescens), a basidiomycete fungus native to the Atlantic forest in Brazil, contains cell walls rich in glucomannan polysaccharides. The ?-(1 ? 2)-gluco-?-(1 ? 3)-mannan was isolated from A. brasiliensis mycelium, chemically modified by sulfation, and named MI-S. MI-S has multiple mechanisms of action, including inhibition of herpes simplex virus (HSV) attachment, entry, and cell-to-cell spread (F. T. G. S. Cardozo, C. M. Camelini, A. Mascarello, M. J. Rossi, R. J. Nunes, C. R. Barardi, M. M. de Mendonça, and C. M. O. Simões, Antiviral Res. 92:108-114, 2011). The antiherpetic efficacy of MI-S was assessed in murine ocular, cutaneous, and genital infection models of HSV. Groups of 10 mice were infected with HSV-1 (strain KOS) or HSV-2 (strain 333). MI-S was given either topically or by oral gavage under various pre- and posttreatment regimens, and the severity of disease and viral titers in ocular and vaginal samples were determined. No toxicity was observed in the uninfected groups treated with MI-S. The topical and oral treatments with MI-S were not effective in reducing ocular disease. Topical application of MI-S on skin lesions was also not effective, but cutaneously infected mice treated orally with MI-S had significantly reduced disease scores (P < 0.05) after day 9, suggesting that healing was accelerated. Vaginal administration of MI-S 20 min before viral challenge reduced the mean disease scores on days 5 to 9 (P < 0.05), viral titers on day 1 (P < 0.05), and mortality (P < 0.0001) in comparison to the control groups (untreated and vehicle treated). These results show that MI-S may be useful as an oral agent to reduce the severity of HSV cutaneous and mucosal lesions and, more importantly, as a microbicide to block sexual transmission of HSV-2 genital infections. PMID:23507287

Cardozo, F T G S; Larsen, I V; Carballo, E V; Jose, G; Stern, R A; Brummel, R C; Camelini, C M; Rossi, M J; Simões, C M O; Brandt, C R

2013-03-18

380

Distribution of 2-[I]iodomelatonin binding in the brain of Mexican free-tailed bats (Tadarida brasiliensis).  

PubMed

The neurohormone melatonin is an important signal for both time of day and time of year in many seasonally breeding animals. High densities of melatonin receptors have been found in the suprachiasmatic nucleus, median eminence, and the pituitary gland in almost all mammals investigated so far, and lower densities of melatonin receptors have also been localized to other brain regions varying in a species-specific fashion. Because species-specific differences in receptor distributions have been correlated with differences in behavior and ecology, a comparative study of how melatonin receptors are distributed in vertebrate brains can be useful to the understanding of the functional organization of neural circuits controlling daily and seasonal behaviors. In this study, we localized and characterized melatonin binding sites in the brain of the Mexican free-tailed bat (Tadarida brasiliensis) using in vitro autoradiography with 2-[(125)I]iodomelatonin. Tadarida brasiliensis is a nocturnal insectivorous mammal that seasonally migrates, reproduces once a year, and exhibits documented sexual dimorphisms in seasonal reproductive behaviors, most notably in courtship vocalizations. Prominent 2-[(125)I]iodomelatonin binding was found in the median eminence, suprachiasmatic nuclei, and hippocampus, similar to that observed in other mammals. High densities of binding were also localized to structures of the basal ganglia, including the caudate nucleus, putamen, and nucleus accumbens, a feature commonly observed in songbirds but not in mammals. Saturation analysis indicated that the observed binding sites had an affinity for melatonin typical of the binding properties for the Mel(1a) receptor subtype. We conclude that melatonin receptor distributions in the Mexican free-tailed bat brain appear to show similarities with the reproductive and circadian systems of other mammals and the basal ganglia of songbirds. PMID:19223684

Schwartz, Christine; Bartell, Paul; Cassone, Vincent; Smotherman, Michael

2009-02-18

381

Distribution of 2-[125I]iodomelatonin Binding in the Brain of Mexican Free-Tailed Bats (Tadarida brasiliensis)  

PubMed Central

The neurohormone melatonin is an important signal for both time of day and time of year in many seasonally breeding animals. High densities of melatonin receptors have been found in the suprachiasmatic nucleus, median eminence, and the pituitary gland in almost all mammals investigated so far, and lower densities of melatonin receptors have also been localized to other brain regions varying in a species-specific fashion. Because species-specific differences in receptor distributions have been correlated with differences in behavior and ecology, a comparative study of how melatonin receptors are distributed in vertebrate brains can be useful to the understanding of the functional organization of neural circuits controlling daily and seasonal behaviors. In this study, we localized and characterized melatonin binding sites in the brain of the Mexican free-tailed bat (Tadarida brasiliensis) using in vitro autoradiography with 2-[125I]iodomelatonin. Tadarida brasiliensis is a nocturnal insectivorous mammal that seasonally migrates, reproduces once a year, and exhibits documented sexual dimorphisms in seasonal reproductive behaviors, most notably in courtship vocalizations. Prominent 2-[125I]iodomelatonin binding was found in the median eminence, suprachiasmatic nuclei, and hippocampus, similar to that observed in other mammals. High densities of binding were also localized to structures of the basal ganglia, including the caudate nucleus, putamen, and nucleus accumbens, a feature commonly observed in songbirds but not in mammals. Saturation analysis indicated that the observed binding sites had an affinity for melatonin typical of the binding properties for the Mel1a receptor subtype. We conclude that melatonin receptor distributions in the Mexican free-tailed bat brain appear to show similarities with the reproductive and circadian systems of other mammals and the basal ganglia of songbirds.

Schwartz, Christine; Bartell, Paul; Cassone, Vincent; Smotherman, Michael

2010-01-01

382

Activation of Nippostrongylus brasiliensis infective larvae is regulated by a pathway distinct from the hookworm Ancylostoma caninum.  

PubMed

Developmentally arrested infective larvae of strongylid nematodes are activated to resume growth by host-derived cues encountered during invasion of the mammalian host. Exposure of Nippostrongylus brasiliensis infective larvae to elevated temperature (37°C) is sufficient to activate signalling pathways which result in resumption of feeding and protein secretion. This occurs independently of exposure to serum or glutathione, in contrast to the hookworm Ancylostoma caninum, and is not initiated by chemical exsheathment. No qualitative differences in protein secretion were induced by host serum as visualised by two-dimensional SDS-PAGE, although exposure of larvae to an aqueous extract of rat skin did stimulate secretion of a small pre-synthesised bolus of proteins. Infective larvae began feeding after a lag period of 3-4 h at 37°C, reaching a maximum of 90% of the population feeding by 48 h. Neither a membrane permeant analogue of cyclic GMP nor muscarinic acetylcholine receptor agonists stimulated feeding at 20°C, and high concentrations of both compounds inhibited temperature-induced activation. LY294002, an inhibitor of phosphatidylinositol 3-kinase, Akt inhibitor IV, an inhibitor of Akt protein kinase, and ketoconazole, an inhibitor of cytochrome P450, all blocked resumption of feeding and protein secretion at 37°C. Serotonin increased the rate of feeding assessed by uptake of radiolabelled BSA, but could not initiate feeding independently of elevated temperature. Collectively, the data suggest that the early signalling events for larval activation in N. brasiliensis differ substantially from A. caninum, but that they may converge at pathways downstream of phosphatidylinositol 3-kinase involving steroid hormone synthesis. PMID:20654619

Huang, Stanley Ching-Cheng; Chan, Denice Tsz Yau; Smyth, Danielle J; Ball, Glyn; Gounaris, Kleoniki; Selkirk, Murray E

2010-07-21

383

Predictive distribution modeling of the sandy-beach supralittoral amphipod Atlantorchestoidea brasiliensis along a macroscale estuarine gradient  

NASA Astrophysics Data System (ADS)

Exposed marine beaches are physically rigorous habitats in which macrofaunal patterns have been well correlated with physical factors. In this context, the habitat safety hypothesis (HSH) predicts an increase in abundance of supralittoral species from dissipative to reflective conditions in microtidal oceanic beaches. However, the HSH has not been adequately tested in estuarine sandy beaches. Here, we build a predictive model based on the supralittoral talitrid amphipod Atlantorchestoidea brasiliensis that allowed us to test the HSH along a macroscale estuarine gradient. Fifteen Uruguayan sandy beaches along a salinity gradient (from 0.1 to 34.3) generated by the Río de la Plata estuary (SW Atlantic Ocean) were sampled over a two-year period. A conditional two-step procedure using a General Additive Model (GAM) was performed in order to model A. brasiliensis occurrence (1st-step) and abundance (2nd-step), based on a comprehensive set of environmental variables [salinity, water temperature, beach face slope (BFS), mean grain size, wave height and sand compaction, moisture and organic matter]. Each GAM was parameterized using generalized linear models (GLMs). An external validation procedure was used. Data were divided randomly into training (75%) and test (25%) sets. The 1st-step GAM/GLM retained 5 physical descriptors in the model (decreasing order of importance): wave height, salinity, BFS, organic matter and sand compaction. The 2nd-step GAM/GLM retained 6 physical descriptors: sand compaction, water content, salinity, wave height, water temperature and organic matter. The predictive ability of these models and the resulted combined model, as well as their external validity, was highly significant and supported the predictions of the HSH. However, the highest and lowest abundances were observed, respectively, on reflective and dissipative beaches in the outer estuary; i.e., the predictions based on the HSH did not account for the high levels of abundance observed on these beaches compared with oceanic ones. Therefore, the HSH was expanded to include microtidal estuarine beaches.

Gómez, Julio; Defeo, Omar

2012-02-01

384

Optical Tweezing of Yeast Cells  

NASA Astrophysics Data System (ADS)

Optical Tweezers is a powerful technique that aids in understanding and applying the unique principles of photonics, optical physics, and basic cell biology. The experiments presented involve using HeNe lasers (632.8 nm) to trap spherical and ovular shaped objects in a solution. Polystyrene spheres, six micrometers in diameter, were trapped and moved with the laser to calibrate our system. The spheres were submerged in a Sodium Phosphate buffer solution to prevent sticking. Saccharomyces cerevisae, better known as yeast, was grown in a glucose rich environment to reach sizes of four to nine micrometers. Our optical tweezers captured and moved these cells under the operators command. A two laser system was utilized to control two cells simultaneously and attempt the splitting of cells. )

Gilroy, Kyle; Ochoa, Romulo

2010-02-01

385

Accelerating Yeast Prion Biology using Droplet Microfluidics  

NASA Astrophysics Data System (ADS)

Prions are infectious proteins in a misfolded form, that can induce normal proteins to take the misfolded state. Yeast prions are relevant, as a model of human prion diseases, and interesting from an evolutionary standpoint. Prions may also be a form of epigenetic inheritance, which allow yeast to adapt to stressful conditions at rates exceeding those of random mutations and propagate that adaptation to their offspring. Encapsulation of yeast in droplet microfluidic devices enables high-throughput measurements with single cell resolution, which would not be feasible using bulk methods. Millions of populations of yeast can be screened to obtain reliable measurements of prion induction and loss rates. The population dynamics of clonal yeast, when a fraction of the cells are prion expressing, can be elucidated. Furthermore, the mechanism by which certain strains of bacteria induce yeast to express prions in the wild can be deduced. Integrating the disparate fields of prion biology and droplet microfluidics reveals a more complete picture of how prions may be more than just diseases and play a functional role in yeast.

Ung, Lloyd; Rotem, Assaf; Jarosz, Daniel; Datta, Manoshi; Lindquist, Susan; Weitz, David

2012-02-01

386

The osmotic stress tolerance of basidiomycetous yeasts.  

PubMed

The growth and accumulation of intracellular polyols at reduced water activity (a(w)) were studied in 40 basidiomycetous yeast strains. The growth of most strains showed greater tolerance to NaCl than sorbitol at the same a(w). No strain was able to grow below 0.90a(w). (13)C nuclear magnetic resonance spectroscopy revealed that glycerol was the major solute accumulated intracellularly by all the yeasts when grown to 0.96a(w) (NaCl). Arabitol or mannitol was also accumulated in some yeasts, whereas a few only accumulated glycerol. Analysis of six yeasts in detail revealed that the intracellular glycerol concentrations of five yeasts increased significantly when grown at 0.96a(w) (NaCl or sorbitol) compared with growth at 0.998a(w). Arabitol and mannitol concentrations also increased, but not to the same degree. Intracellular potassium concentrations decreased when grown at 0.96a(w) (NaCl or sorbitol) and sodium increased, but only when grown at 0.96a(w) (NaCl). The survival of nine strains was evaluated in soil cultures and it was found that all grew at 100% field capacity, whereas at lower field capacity, only some strains grew or survived. The growth of basidiomycetous yeasts appears to be more sensitive to reduced a(w) than ascomycetous yeasts. PMID:20214685

Tekolo, Obakeng M; McKenzie, Jean; Botha, Alfred; Prior, Bernard A

2010-02-26

387

Analysis of genetic variation in clones of rubber (Hevea brasiliensis) from Asian, South and Central American origin using RAPDs markers AnÆlisis de la variaciÛn genØtica en clones de caucho (Hevea brasiliensis) de Asia, SuramØrica y CentroamØrica usando marcadores RAPD  

Microsoft Academic Search

Rubber (Hevea brasiliensis) represents a potential species for reforestation and commercial exploitation programmes in tropical countries such as Colombia. The genetic variability of a rubber collection kept at the Paraguaicito Experimental Station in Buenavista in the Quindio department of Colombia was studied to improve knowledge regarding this species and make better use of the trees available. A total of 25

Afanador Kafuri; Rafael Arango Isaza; Mario Lobo Arias

388

Hydrogen Peroxide Metabolism in Yeasts  

PubMed Central

A catalase-negative mutant of the yeast Hansenula polymorpha consumed methanol in the presence of glucose when the organism was grown in carbon-limited chemostat cultures. The organism was apparently able to decompose the H2O2 generated in the oxidation of methanol by alcohol oxidase. Not only H2O2 generated intracellularly but also H2O2 added extracellularly was effectively destroyed by the catalase-negative mutant. From the rate of H2O2 consumption during growth in chemostat cultures on mixtures of glucose and H2O2, it appeared that the mutant was capable of decomposing H2O2 at a rate as high as 8 mmol · g of cells?1 · h?1. Glutathione peroxidase (EC 1.11.1.9) was absent under all growth conditions. However, cytochrome c peroxidase (CCP; EC 1.11.1.5) increased to very high levels in cells which decomposed H2O2. When wild-type H. polymorpha was grown on mixtures of glucose and methanol, the CCP level was independent of the rate of methanol utilization, whereas the level of catalase increased with increasing amounts of methanol in the substrate feed. Also, the wild type decomposed H2O2 at a high rate when cells were grown on mixtures of glucose and H2O2. In this case, an increase of both CCP and catalase was observed. When Saccharomyces cerevisiae was grown on mixtures of glucose and H2O2, the level of catalase remained low, but CCP increased with increasing rates of H2O2 utilization. From these observations and an analysis of cell yields under the various conditions, two conclusions can be drawn. (i) CCP is a key enzyme of H2O2 detoxification in yeasts. (ii) Catalase can effectively compete with mitochondrial CCP for hydrogen peroxide only if hydrogen peroxide is generated at the site where catalase is located, namely in the peroxisomes.

Verduyn, Cornelis; Giuseppin, Marco L. F.; Scheffers, W. Alexander; van Dijken, Johannes P.

1988-01-01

389

Adhesive interactions between medically important yeasts and bacteria  

Microsoft Academic Search

Yeasts are being increasingly identified as important organisms in human infections. Adhesive interactions between yeasts and bacteria may contribute to yeast retention at body sites. Methods for studying adhesive interactions between bacterial strains are well known, and range from simple macroscopic methods to flow chamber systems with complex image analysis capabilities. The adhesive interactions between bacteria and yeasts have been

Kevin W. Millsap; Henny C. van der Mei; Rolf Bos; Henk J. Busscher

1998-01-01

390

Physiological and Molecular Responses of Yeasts to the Environment  

Microsoft Academic Search

Understanding the ways by which yeasts respond to changes in their physicochemical environment is very important in the food and beverage industries. For example, it is important for the maintenance of yeast viability and vitality in the production and utilisation of yeasts for food and fermentation processes, and it is additionally important for the control of yeasts that act as

GRAEME M. WALKER; PATRICK VAN DIJCK

391

Pleiotropic Signaling Pathways Orchestrate Yeast Development  

PubMed Central

Developmental phenotypes in Saccharomyces cerevisiae and related yeasts include responses such as filamentous growth, sporulation, and the formation of biofilms and complex colonies. These developmental phenotypes are regulated by evolutionarily conserved, nutrient-responsive signaling networks. The signaling mechanisms that control development in yeast are highly pleiotropic – all of the known pathways contribute to the regulation of multiple developmental outcomes. This degree of pleiotropy implies that perturbations of these signaling pathways, whether genetic, biochemical or environmentally induced, can manifest in multiple (and sometimes unexpected) ways. We summarize the current state of knowledge of developmental pleiotropy in yeast and discuss its implications for understanding functional relationships.

Granek, Joshua A.; Kay?kc?, Omur

2011-01-01

392

Yeast display of engineered antibody domains.  

PubMed

Yeast display is an efficient technology for selection of antibodies and other proteins with high affinity and thermal stability. Here, we describe a method for affinity maturation of engineered antibody domains (eAds) using yeast display. EAd yeast libraries of relatively large size (?10?) were generated and subjected to alternating rounds of magnetic-activated cell sorting (MACS), fluorescent-activated cell sorting (FACS), and random mutagenesis. The highest affinity clones from the final round of maturation were identified and analyzed. We discuss extensively each key step, and provide detailed protocols and helpful notes. PMID:22735947

Zhao, Qi; Zhu, Zhongyu; Dimitrov, Dimiter S

2012-01-01

393

Characterization of virulence profile, protein secretion and immunogenicity of different Sporothrix schenckii sensu stricto isolates compared with S. globosa and S. brasiliensis species.  

PubMed

A comparative study about protein secretion, immunogenicity and virulence was performed in order to characterize and to compare eight Sporothrix schenckii sensu stricto isolates. For virulence characterization, a murine model, based on survival assay and CFU counting was used. S. brasiliensis and S. globosa, a highly virulent and a non-virulent isolates, respectively were used as external controls. Exoantigen profiles showed different secreted molecules; the 46- and 60-kDa molecules were commonly secreted by all three species. The S. schenckii s. str. isolates could be classified as non-virulent or presenting low, medium or high virulence, based on survival times after infection and recovery of viable fungi. The humoral response profiles of mice infected with S. schenckii s. str., S. globosa and S. brasiliensis were heterogeneous; five virulent isolates (S. schenckii s. str., n = 4 and S. brasiliensis, n = 1) had in common the recognition of the 60-kDa molecule by their respective antisera, suggesting that this antigen may be involved in virulence. Furthermore, the 110-kDa molecule was secreted and recognized by antisera from four virulent isolates (S. schenckii s. str., n = 3 and S. brasiliensis, n = 1), so there is a possibility that this molecule is also related to virulence. Our findings reveal different degrees of virulence in S. schenckii s. str. isolates and suggest the correlation of protein secretion and immunogenicity with virulence of S. schenckii complex. These findings provide new insights into the pathogenesis of S. schenckii s. str. and improve the knowledge about immunogenicity and protein profiles in S. schenckii complex. PMID:23324498

Fernandes, Geisa Ferreira; dos Santos, Priscila Oliveira; Rodrigues, Anderson Messias; Sasaki, Alexandre Augusto; Burger, Eva; de Camargo, Zoilo Pires

2013-01-16

394

Determination of new immunoadjuvant saponin named QB90, and analysis of its organ-specific distribution in Quillaja brasiliensis by HPLC  

Microsoft Academic Search

An LC method was developed and validated in order to quantify the saponin purified fraction named QB-90 obtained from the aqueous extracts of Quillaja brasiliensis leaves. Previously, QB-90 was shown to be active as adjuvant in an experimental vaccine for herpesvirus bovine type 1 in mice. The analysis was performed using an RP-8 column with acetonitrile:water isocratic elution at 214?nm.

Juliane D. Fleck; Fernanda de Costa; Anna C. A. Yendo; Jéferson Segalin; Teresa C. T. Dalla Costa; Arthur G. Fett-Neto; Grace Gosmann

2012-01-01

395

Safety study of culinary-medicinal Royal Sun Agaricus, Agaricus brasiliensis S. Wasser et al. KA21 (higher Basidiomycetes) assessed by prokaryotic as well as eukaryotic systems.  

PubMed

As part of the safety evaluation of culinary-medicinal Royal Sun Agaricus, Agaricus brasiliensis KA21, for human consumption, we performed the bacterial reverse mutation test, the mouse micronucleus test, and mouse lymphoma test using A. brasiliensis KA21 as the test substance. The reverse mutation test utilized five bacterial strains, including Salmonella typhimurium TA100, TA1535, TA98, and TA1537, and Escherichia coli WP2 uvrAO. For the micronucleus test we used mice. For the mouse lymphoma test, we used one of the most commonly used mammalian cell mutagenesis systems; the L5178YTK +/- mouse lymphoma-TK assay detects the mutations at the thymidine kinase locus caused by base-pair changes, frameshift, and small deletions. All the tests were conducted according to the guidelines for genotoxicity testing of drugs by the Ministry of Health, Labor, and Welfare, Japan. In the bacterial reverse mutation test, no toxicity was observed up to a dose of 5,000 ?g/plate. In the mouse micronucleus test, no toxicity was noted up to a dose of 1 g/kg body weight. In the mouse lymphoma test, frequency of the mutation was equal both in the presence or absence of KA21. Supporting the long history of human consumption of A. brasiliensis, the data shown in this study strongly indicate the safety of this mushroom. PMID:22506574

Motoi, Masuro; Ohno, Naohito

2012-01-01

396

Eco-epidemiology of Chagas disease in northeastern Brazil: Triatoma brasiliensis, T. pseudomaculata and Rhodnius nasutus in the sylvatic, peridomestic and domestic environments.  

PubMed

An entomological survey was carried out in four rural localities situated in the state of Ceará, assessing Chagas disease seroprevalence in man, focusing on the presence of vectors in natural foci contiguous to the domestic and peridomestic environments. Fifty-three Triatoma brasiliensis, nine T. pseudomaculata and 71 Rhodnius nasutus were collected in their natural habitats as far as 10 m from the houses, and 663, 59 and 8 respectively were captured in peridomestic artificial structures, adjacent to the houses, including henhouses, pigpens, corrals, perches and piles of bricks, tiles and wood. Within the households, 37?T. brasiliensis, one specimen of T. pseudomaculata and one of R. nasutus were captured. Overall, Trypanosoma cruzi infection rates were 2.3% for T. brasiliensis and 11.3% for R. nasutus. Despite that the seroprevalence survey in man did not reveal positive results using two serological techniques, natural triatomine habitats are juxtaposed to man-made artificial ecotopes, resulting in overlapping habitats. The contiguity between natural ecotopes and human dwellings increases the interaction between vectors and humans, challenging continuous surveillance and vector control efforts. PMID:21979785

Sarquis, Otília; Carvalho-Costa, Filipe Anibal; Toma, Helena Keiko; Georg, Ingebourg; Burgoa, Marcelo R; Lima, Marli Maria

2011-10-07

397

Lung-resident CD4(+) T cells are sufficient for IL-4R?-dependent recall immunity to Nippostrongylus brasiliensis infection.  

PubMed

Immunity to Nippostrongylus brasiliensis reinfection requires pulmonary CD4(+) T-cell responses. We examined whether secondary lymphoid recruited or pre-existing lung CD4(+) T-cell populations coordinated this immunity. To do this, we blocked T-cell egress from lymph nodes using Fingolimod (FTY720). This impaired host ability to resolve a primary infection but did not change effectiveness of recall immunity. Associated with this effective recall immunity was the expansion and T helper type 2 polarization of a pre-existing pulmonary CD4(+) T-cell population. LT?R-Ig (lymphotoxin beta-receptor fusion protein)-mediated disruption of stromal cell organization of immune cells did not disrupt this recall immunity, suggesting that protection was mediated by a pulmonary interstitial residing CD4(+) T-cell population. Adoptive transfer of N. brasiliensis-experienced pulmonary CD4(+) T cells from FTY720-treated wild-type or T-cell interleukin (IL)-4R?-deficient mice demonstrated protection to be IL-4R? dependent. These results show that pre-existing CD4(+) T cells can drive effective recall immunity to N. brasiliensis infection independently of T-cell recruitment from secondary lymphoid organs.Mucosal Immunology advance online publication 19 June 2013; doi:10.1038/mi.2013.40. PMID:23778354

Thawer, S G; Horsnell, W Gc; Darby, M; Hoving, J C; Dewals, B; Cutler, A J; Lang, D; Brombacher, F

2013-06-19

398

Arachidonic acid metabolites in pathogenic yeasts  

PubMed Central

Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2? and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed.

2012-01-01

399

Functional analysis of the yeast genome  

Microsoft Academic Search

.   Just as Saccharomyces cerevisiae itself provides a model for so many processes essential to eukaryotic life, we anticipate that the methods and the mindset\\u000a that have moved yeast biological research \\

Petra Ross-Macdonald

2000-01-01

400

Immobilized Yeasts: Growth and Metabolism, Alcohol Fermentation.  

National Technical Information Service (NTIS)

The reaction characteristics of Saccharomyces uvarum immobilized in solid supports are presented. Two types of solid supports are used, porous brick and porous silica. Yeast adsorption and covalent coupling, influence of pore size on adsorption are evalua...

J. M. Navarro

1980-01-01

401

Propagation of Mammalian Prions in Yeast.  

National Technical Information Service (NTIS)

The focus of this grant is on development of a novel model system for propagation and quantitation of mammalian prions: the budding yeast Saccharomyces cerevisiae. This unicellular organism offers a number of potential advantages for the study of prion bi...

D. A. Harris

2006-01-01

402

[Regulation of gene expression in methylotrophic yeasts].  

PubMed

Methylotrophic yeasts are unique eukaryotic organisms, that can metabolize toxic one-carbon substrate, methyl alcohol or methanol. About 50 species of methylotrophic yeasts is known, among them 4 species are the best studied: Pichia methanolica, Hansenula polymorpha, Pichia pastoris i Candida boidinii. These organisms, especially P. pastoris i H. polymorpha appeared to be very perspective overproducers of heterologous proteins and nowadays are used for industrial production of some of them. In this review, we provide information on the organization of the genome, mechanisms of regulation of gene expression and the use of strong promoters of these yeast species to construct the producers of heterologous proteins. In more details, we analyze genetic control of carbon and nitrogen catabolic repression in H. polymorpha and also the identification of metabolites inducing catabolite repression or peroxisome selective autophagy in the medium with ethanol in the Pichia methanolica yeast. PMID:23821948

Grabek-Lejko, Dorota; Sibirny, Vladimir; Sibirny, Andriy

2013-01-01

403

Monitoring Air Quality with Leaf Yeasts.  

ERIC Educational Resources Information Center

|Proposes that leaf yeast serve as quick, inexpensive, and effective techniques for monitoring air quality. Outlines procedures and provides suggestions for data analysis. Includes results from sample school groups who employed this technique. (ML)|

Richardson, D. H. S.; And Others

1985-01-01

404

Yeast Screens for Treatment of Human Disease.  

National Technical Information Service (NTIS)

Screening methods for identifying substances that provide therapeutic value for various diseases associated with protein misfolding are provided. Genetic and chemical screening methods are provided using a yeast system. The methods of the invention provid...

S. Krobitsch S. Lindquist T. F. Outeiro

2006-01-01

405

ENGINEERING THE BIOSYNTHESIS OF STYRENE IN YEAST  

EPA Science Inventory

The strategy pursued was to insert genes for phenylalanine ammonia lysase (pal) and phenolic acid decarboxylase (pad) into the yeast that would convert phenylalanine to styrene through a cinnamic acid intermediate. ...

406

CYGD: the Comprehensive Yeast Genome Database.  

PubMed

The Comprehensive Yeast Genome Database (CYGD) compiles a comprehensive data resource for information on the cellular functions of the yeast Saccharomyces cerevisiae and related species, chosen as the best understood model organism for eukaryotes. The database serves as a common resource generated by a European consortium, going beyond the provision of sequence information and functional annotations on individual genes and proteins. In addition, it provides information on the physical and functional interactions among proteins as well as other genetic elements. These cellular networks include metabolic and regulatory pathways, signal transduction and transport processes as well as co-regulated gene clusters. As more yeast genomes are published, their annotation becomes greatly facilitated using S.cerevisiae as a reference. CYGD provides a way of exploring related genomes with the aid of the S.cerevisiae genome as a backbone and SIMAP, the Similarity Matrix of Proteins. The comprehensive resource is available under http://mips.gsf.de/genre/proj/yeast/. PMID:15608217

Güldener, U; Münsterkötter, M; Kastenmüller, G; Strack, N; van Helden, J; Lemer, C; Richelles, J; Wodak, S J; García-Martínez, J; Pérez-Ortín, J E; Michael, H; Kaps, A; Talla, E; Dujon, B; André, B; Souciet, J L; De Montigny, J; Bon, E; Gaillardin, C; Mewes, H W

2005-01-01

407

CYGD: the Comprehensive Yeast Genome Database  

PubMed Central

The Comprehensive Yeast Genome Database (CYGD) compiles a comprehensive data resource for information on the cellular functions of the yeast Saccharomyces cerevisiae and related species, chosen as the best understood model organism for eukaryotes. The database serves as a common resource generated by a European consortium, going beyond the provision of sequence information and functional annotations on individual genes and proteins. In addition, it provides information on the physical and functional interactions among proteins as well as other genetic elements. These cellular networks include metabolic and regulatory pathways, signal transduction and transport processes as well as co-regulated gene clusters. As more yeast genomes are published, their annotation becomes greatly facilitated using S.cerevisiae as a reference. CYGD provides a way of exploring related genomes with the aid of the S.cerevisiae genome as a backbone and SIMAP, the Similarity Matrix of Proteins. The comprehensive resource is available under http://mips.gsf.de/genre/proj/yeast/.

Guldener, U.; Munsterkotter, M.; Kastenmuller, G.; Strack, N.; van Helden, J.; Lemer, C.; Richelles, J.; Wodak, S. J.; Garcia-Martinez, J.; Perez-Ortin, J. E.; Michael, H.; Kaps, A.; Talla, E.; Dujon, B.; Andre, B.; Souciet, J. L.; De Montigny, J.; Bon, E.; Gaillardin, C.; Mewes, H. W.

2005-01-01

408

Ethanol inhibition of continuous anaerobic yeast growth  

Microsoft Academic Search

The inhibitory effect of ethanol on the yeast Saccharomyces cerevisiae ATCC 4126 has been studied in continuous culture under conditions where high concentrations of ethanol were produced by the yeast itself. The fermentations were carried out using a glucose, salts medium at glucose concentrations of 20, 100 and 200 gl-1. The growth function\\u000a$$\\\\mu = \\\\hat \\\\mu \\\\cdot \\\\frac{{C_s }}{{K_s

Gerhard K Hoppe; Geoffrey S Hansford

1982-01-01

409

Arsenic metabolism in marine bacteria and yeast  

Microsoft Academic Search

Arsenic metabolism was studied for two marine microorganisms, a facultative anaerobic bacterium, Serratia marinorubra, and an obligately aerobic yeast, Rhodotorula rubra. Both were cultivated in media with (74As) arsenate (As V), and the products of arsenate metabolism were determined qualitatively. Both the bacterium and the yeast produced arsenite (AS III) and methylarsonic acid [CH3AsO(OH)2]. In addition to the foregoing, only

F. V. Vidal; V. M. V. Vidal

1980-01-01

410

How To Make Yeast Cells Thrive  

NSDL National Science Digital Library

Students set up and run the experiments they designed in the lesson Population Growth in Yeasts, using simple yeast-molasses cultures in test tubes. Population growth is indicated by the amount of respiration occurring in the cultures, which in turn is indicated by the growth of carbon dioxide bubbles trapped within the culture tubes. Using this method, students can test for a variety of environmental influences, such as temperature, food supply, and pH.

Engineering K-Ph.d. Program

411

Featured Organism: Schizosaccharomyces pombe, The Fission Yeast  

PubMed Central

Schizosaccharomyces pombe, the fission yeast, has long been a crucial model for the study of the eukaryote cell cycle. We take a look at this important yeast, whose genome has recently been completed, featuring comments from Valerie Wood, Jürg Bähler, Ramsay McFarlane, Susan Forsburg, Iain Hagan and Paul Nurse on the implications of having the complete sequence and future prospects for pombe genomics.

2002-01-01

412

Mitochondria, metabolism, and aging in yeast  

Microsoft Academic Search

\\u000a Quantitative and qualitative changes in metabolism take place when the lifespan is extended in yeast either by genetic or\\u000a nutritional manipulation. In particular, remodeling of mitochondrial function occurs, and the relationship between this organelle\\u000a and other cellular compartments moves to the fore. Two separate pathways, the retrograde response and calorie restriction,\\u000a operate as metabolic mechanisms for life extension in yeast.

S. Michal Jazwinski

413

A yeast biosensor for glucose determination  

Microsoft Academic Search

A yeast potentiometric biosensor for glucose determination is described. After induction of glycolytic enzyme synthesis a cell suspension of the yeast Hansenula anomala is retained in calcium alginate gel on the surface of a glass electrode. This biosensor gives a Nernstian response in glucose concentration of 5·10-4–5·10-3 mol\\/l with a response time of 5 min and a life-time of at

Jaroslav Racek

1991-01-01

414

Whey Alcohol Fermentation with Mixed Yeast Cultures  

Microsoft Academic Search

This paper study the process of whey alcohol fermentation with mixed yeasts cultures. After the experiments of strains combination, the yeast strains of Saccharomyces uvarum TY-3, Saccharomyces uvarum TY-1 and Saccharomyces carlsbergensis AY-5 were selected and mixed at the ratio of 5.0:2.5:2.5. The optimized fermenting condition was obtained through orthogonal experiments with the result as follows: the initial pH value

Wang Jianming; Guo Linhai; Zhao Guoren

2009-01-01

415

The secretory pathway: exploring yeast diversity.  

PubMed

Protein secretion is an essential process for living organisms. In eukaryotes, this encompasses numerous steps mediated by several hundred cellular proteins. The core functions of translocation through the endoplasmic reticulum membrane, primary glycosylation, folding and quality control, and vesicle-mediated secretion are similar from yeasts to higher eukaryotes. However, recent research has revealed significant functional differences between yeasts and mammalian cells, and even among diverse yeast species. This review provides a current overview of the canonical protein secretion pathway in the model yeast Saccharomyces cerevisiae, highlighting differences to mammalian cells as well as currently unresolved questions, and provides a genomic comparison of the S. cerevisiae pathway to seven other yeast species where secretion has been investigated due to their attraction as protein production platforms, or for their relevance as pathogens. The analysis of Candida albicans, Candida glabrata, Kluyveromyces lactis, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, and Schizosaccharomyces pombe reveals that many - but not all - secretion steps are more redundant in S. cerevisiae due to duplicated genes, while some processes are even absent in this model yeast. Recent research obviates that even where homologous genes are present, small differences in protein sequence and/or differences in the regulation of gene expression may lead to quite different protein secretion phenotypes. PMID:23480475

Delic, Marizela; Valli, Minoska; Graf, Alexandra B; Pfeffer, Martin; Mattanovich, Diethard; Gasser, Brigitte

2013-04-12

416

Phylogenetics of Saccharomycetales, the ascomycete yeasts.  

PubMed

Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial and biotechnological processes, including baking, brewing and synthesis of recombinant proteins. Species such as Saccharomyces cerevisiae are model organisms in research, some of which led to a Nobel Prize. Yeasts usually reproduce asexually by budding, and their sexual states are not enclosed in a fruiting body. The group also is well defined by synapomorphies visible at the ultrastructural level. Yeast identification and classification changed dramatically with the availability of DNA sequencing. Species identification now benefits from a constantly updated sequence database and no longer relies on ambiguous growth tests. A phylogeny based on single gene analyses has shown the order to be remarkably divergent despite morphological similarities among members. The limits of many previously described genera are not supported by sequence comparisons, and multigene phylogenetic studies are under way to provide a stable circumscription of genera, families and orders. One recent multigene study has resolved species of the Saccharomycetaceae into genera that differ markedly from those defined by analysis of morphology and growth responses, and similar changes are likely to occur in other branches of the yeast tree as additional sequences become available. PMID:17486976

Suh, Sung-Oui; Blackwell, Meredith; Kurtzman, Cletus P; Lachance, Marc-André

417

Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis  

Microsoft Academic Search

Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced

Christopher A. Desjardins; Mia D. Champion; Jason W. Holder; Anna Muszewska; Jonathan Goldberg; Alexandre M. Bailão; Marcelo Macedo Brigido; Márcia Eliana da Silva Ferreira; Ana Maria Garcia; Marcin Grynberg; Sharvari Gujja; David I. Heiman; Matthew R. Henn; Chinnappa D. Kodira; Henry León-Narváez; Larissa V. G. Longo; Li-Jun Ma; Alisson L. Matsuo; Flavia V. Morais; Maristela Pereira; Sabrina Rodríguez-Brito; Sharadha Sakthikumar; Silvia M. Salem-Izacc; Sean M. Sykes; Marcus Melo Teixeira; Milene C. Vallejo; Maria Emília Machado Telles Walter; Chandri Yandava; Sarah Young; Qiandong Zeng; Jeremy Zucker; Maria Sueli Felipe; Gustavo H. Goldman; Brian J. Haas; Juan G. McEwen; Gustavo Nino-Vega; Rosana Puccia; Gioconda San-Blas; Celia Maria de Almeida Soares; Bruce W. Birren; Christina A. Cuomo

2011-01-01

418

Inhibition of yeast glutathione reductase by trehalose: possible implications in yeast survival and recovery from stress  

Microsoft Academic Search

Accumulation of trehalose has been implicated in the tolerance of yeast cells to several forms of stress, including heat-shock and high ethanol levels. However, yeast lacking trehalase, the enzyme that degrades trehalose, exhibit poor survival after exposure to stress conditions. This suggests that optimal cell viability also depends on the capacity to rapidly degrade the high levels of trehalose that

Adriano Sebollela; Paulo Roberto Louzada; Mauro Sola-Penna; Verietta Sarone-Williams; Tatiana Coelho-Sampaio; Sérgio T. Ferreira

2004-01-01

419

Utilisation of spent brewer's yeast for yeast extract production by autolysis: The effect of temperature  

Microsoft Academic Search

In this study, autolysis was induced by incubating cell suspensions of spent brewer's yeast at elevated temperatures of 45, 50, 55 and 60°C with a reaction time ranging from 8 to 72h. Contents and yields of solid, ?-amino nitrogen, protein and carbohydrate were determined. It can be said that optimum temperature and time for the production of yeast extract was

Hasan Tanguler; Huseyin Erten

2008-01-01

420

The Effect of Different Temperatures on Autolysis of Baker's Yeast for the Production of Yeast Extract  

Microsoft Academic Search

This study aimed to determine the optimum autolysis conditions for the production of yeast extract, which is used to give a meaty flavor to food products and to increase their nutritional value. Autolysis was induced by incubating baker's yeast cell suspensions at different temperatures (45, 50, 55, and 60 °C) with a reaction time ranging from 8 to 72 h.

Hasan TANGÜLER; Hüseyin ERTEN

421

Boolean Model of Yeast Apoptosis as a Tool to Study Yeast and Human Apoptotic Regulations  

PubMed Central

Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested.

Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

2012-01-01

422

The 26S proteasome degrades mouse and yeast ornithine decarboxylase in yeast cells.  

PubMed

Eukaryotic cells possess two high-molecular-mass proteases, the 700 kDa, 20S proteasome, as well as the even larger 1,400 kDa, 26S proteasome. It has been demonstrated that ornithine decarboxylase is degraded, in vitro, by the 26S proteasome that contains the 20S protease as its catalytic core, but not by the free 20S proteasome. Recently, by demonstrating severe inhibition of mouse and yeast ODC degradation in a mutant yeast cell line, defective in the chymotripsin-like activity of the yeast 20S proteasome, we implicated the 20S proteasome in the degradation of ODC, in vivo, in yeast cells. Here we show that the degradation of ODC is also severely inhibited in the mutant yeast cell lines, cim3-1 and cim5-1, containing a specific lesion in subunits that are unique to the yeast 26S proteasome. We therefore, conclude, that as illustrated in vitro, also in intact cells, it is the 26S proteasome, not the free 20S proteasome, that degrades ODC. We also demonstrate, that while deficiency in the proteasome chymotrypsine-like activity (in the yeast pre1-1 mutant) inhibits the degradation of both yeast and mouse ODCs, deficiency in the peptidyl-glutamyl-peptide-hydrolyzing (PGPH) activity inhibits only yeast ODC degradation. Similarly, we have noted that whereas the putative ATPase activity of both the CIM3 and CIM5 subunits is essential for the degradation of mouse ODC, only that of the CIM3 subunit is required for the degradation of yeast ODC. These results suggest differential utilization of individual proteasomal subunits in the recognition and degradation of individual short-lived proteins. PMID:7805829

Mamroud-Kidron, E; Kahana, C

1994-12-19

423

The role of adjuvants in therapeutic protection against paracoccidioidomycosis after immunization with the P10 peptide  

PubMed Central

Paracoccidioidomycosis (PCM), a common chronic mycosis in Latin America, is a granulomatous systemic disease caused by the thermo-dimorphic fungus Paracoccidioides brasiliensis. The glycoprotein gp43 is the main antigen target of P. brasiliensis and a 15-mer internal peptide (QTLIAIHTLAIRYAN), known as P10, defines a major CD4+-specific T cell epitope. Previous results have indicated that, besides having a preventive role in conventional immunizations prior to challenge with the fungus, protective anti-fungal effects can be induced in P. brasiliensis-infected mice treated with P10 administered with complete Freund’s adjuvant (CFA). The peptide elicits an IFN-?-dependent Th1 immune response and is the main candidate for effective immunotherapy of patients with PCM, as an adjunctive approach to conventional chemotherapy. In the present study we tested the therapeutic effects of P10 combined with different adjuvants [aluminum hydroxide, CFA, flagellin, and the cationic lipid dioctadecyl-dimethylammonium bromide (DODAB)] in BALB/c mice previously infected with the P. brasiliensis Pb18 strain. Significant reductions in the number of colony forming units of the fungus were detected in lungs of mice immunized with P10 associated with the different adjuvants 52 days after infection. Mice treated with DODAB and P10, followed by mice treated with P10 and flagellin, showed the most prominent effects as demonstrated by the lowest numbers of viable yeast cells as well as reductions in granuloma formation and fibrosis. Concomitantly, secretion of IFN-? and TNF-?, in contrast to interleukin (IL)-4 and IL-10, was enhanced in the lungs of mice immunized with P10 in combination with the tested adjuvants, with the best results observed in mice treated with P10 and DODAB. In conclusion, the present results demonstrate that the co-administration of the synthetic P10 peptide with several adjuvants, particularly DODAB, have significant therapeutic effects in experimental PCM.

Mayorga, Oriana; Munoz, Julian E.; Lincopan, Nilton; Teixeira, Aline F.; Ferreira, Luis C. S.; Travassos, Luiz R.; Taborda, Carlos P.

2012-01-01

424

Mitochondrial membrane lipidome defines yeast longevity.  

PubMed

Our studies revealed that lithocholic acid (LCA), a bile acid, is a potent anti-aging natural compound that in yeast cultured under longevity-extending caloric restriction (CR) conditions acts in synergy with CR to enable a significant further increase in chronological lifespan. Here, we investigate a mechanism underlying this robust longevity-extending effect of LCA under CR. We found that exogenously added LCA enters yeast cells, is sorted to mitochondria, resides mainly in the inner mitochondrial membrane, and also associates with the outer mitochondrial membrane. LCA elicits an age-related remodeling of glycerophospholipid synthesis and movement within both mitochondrial membranes, thereby causing substantial changes in mitochondrial membrane lipidome and triggering major changes in mitochondrial size, number and morphology. In synergy, these changes in the membrane lipidome and morphology of mitochondria alter the age-related chronology of mitochondrial respiration, membrane potential, ATP synthesis and reactive oxygen species homeostasis. The LCA-driven alterations in the age-related dynamics of these vital mitochondrial processes extend yeast longevity. In sum, our findings suggest a mechanism underlying the ability of LCA to delay chronological aging in yeast by accumulating in both mitochondrial membranes and altering their glycerophospholipid compositions. We concluded that mitochondrial membrane lipidome plays an essential role in defining yeast longevity. PMID:23924582

Beach, Adam; Richard, Vincent R; Leonov, Anna; Burstein, Michelle T; Bourque, Simon D; Koupaki, Olivia; Juneau, Mylène; Feldman, Rachel; Iouk, Tatiana; Titorenko, Vladimir I

2013-07-01

425

Yeasts associated with Sardinian ewe's dairy products.  

PubMed

In the present work, the occurrence of yeasts in different types of typical Sardinian ewe's cheeses (32 samples of pecorino, 32 of caciotta, 40 of feta, 56 of ricotta) was determined. For the strains isolated the following properties were studied: proteolytic and lipolytic activities, the ability to grow at different temperatures, different concentrations of salt, and to assimilate and/or ferment compounds like lactate, citrate, lactose, glucose, galactose, lactic acid. Of 160 samples analysed, 76.2% yielded growth of yeasts. Yeast counts showed a certain variability among the samples. The highest levels were observed in caciotta and feta cheeses. A total of 281 strains belonging to 16 genera and 25 species were identified. In general, Debaryomyces hansenii was the dominant species, representing 28.8% of the total isolates. Other frequently appearing species were Geotrichum candidum, Kluyveromyces lactis and K. marxianus. Other genera encountered were Pichia, Candida, Dekkera, Yarrowia and Rhodotorula. With regard to the biochemical and technological properties of the yeasts, only K. lactis, K. marxianus and Dek. anomala assimilated and fermented lactose, whereas the majority of the species assimilated lactic acid. The assimilation of citrate was a characteristic of D. hansenii, R. rubra and Y. lipolytica. On the whole, the yeasts were weakly proteolytic while lipolytic activity was present in several species. A high percentage of strains showed a certain tolerance to low temperatures while only some strains of D. hansenii and K. lactis were able to grow at a 10% NaCl concentration. PMID:11589560

Cosentino, S; Fadda, M E; Deplano, M; Mulargia, A F; Palmas, F

2001-09-19

426

Applicability of yeast genetics to neurologic disease.  

PubMed

As advances in gene mapping technology reveal genes associated with neurologic diseases, the need to identify a gene's normal function arises often. Experimental genetics is very useful in identifying a gene's function. It relies on model organisms both because it is not appropriate in humans, and because many processes are remarkably similar among eukaryotes. Many cellular processes have evolved once, and species differences are variations on a theme. Molecular genetic tools available in the yeast Saccharomyces cerevisiae provide a means to more rapidly reach an understanding of gene function, yielding substantial insight into the same process in humans. Yeast will never complain of headache or "spells," but do have expansions of trinucleotide repeats, prions, and other processes very much analogous to those underlying many neurologic diseases. In spite of the absence of a nervous system in yeast, yeast genetics has contributed substantial insight into neurologic diseases mechanisms. The real strength of yeast in studying human disease is in genetic analysis of gene function and in providing genetically powerful functional assays. Arch Neurol. 2000;57:1129-1134 PMID:10927792

Walberg, M W

2000-08-01

427

Influence of pesticides on yeasts colonizing leaves.  

PubMed

The effect of nine different pesticides on the growth of yeasts isolated from the leaves of fruit and forest trees was investigated. Four insecticides (with the active ingredients: thiacloprid, deltamethrin, lambdacyhalothrin, and thiamethoxam) and five fungicides (with the effective substances: bitertanol, kresoxim-methyl, mancozeb, trifloxystrobin, and cupric oxychloride) were tested. The concentrations of chemicals were those recommended by the manufacturers for the spraying of trees. The yeast strains isolated from the leaves of fruit trees were not sensitive to any of the insecticides. The majority of yeast strains isolated from the leaves of forest trees were either not sensitive or only to a small extent. While Rhodotorula mucilaginosa and Pichia anomala were not affected by any insecticide, the strains of Cryptococcus laurentii and Rhodotorula glutinis showed the highest sensitivity. The effects of fungicides on the growth of isolated yeasts were more substantial. The fungicide Dithane DG (mancozeb) completely inhibited the growth of all yeasts. All strains isolated from fruit tree leaves were more resistant to the tested fungicides than those isolated from the leaves of forest trees. The most resistant strains from the leaves of fruit trees belonged to the species Metschnikowia pulcherrima, Pichia anomala, and Saccharomyces cerevisiae, whereas Cryptococcus albidus and C. laurentii, originating from the leaves of forest trees, showed the highest sensitivity to fungicides. PMID:22351984

Vadkertiová, Renata; Sláviková, Elena

428

Mitochondrial membrane lipidome defines yeast longevity  

PubMed Central

Our studies revealed that lithocholic acid (LCA), a bile acid, is a potent anti-aging natural compound that in yeast cultured under longevity-extending caloric restriction (CR) conditions acts in synergy with CR to enable a significant further increase in chronological lifespan. Here, we investigate a mechanism underlying this robust longevity-extending effect of LCA under CR. We found that exogenously added LCA enters yeast cells, is sorted to mitochondria, resides mainly in the inner mitochondrial membrane, and also associates with the outer mitochondrial membrane. LCA elicits an age-related remodeling of glycerophospholipid synthesis and movement within both mitochondrial membranes, thereby causing substantial changes in mitochondrial membrane lipidome and triggering major changes in mitochondrial size, number and morphology. In synergy, these changes in the membrane lipidome and morphology of mitochondria alter the age-related chronology of mitochondrial respiration, membrane potential, ATP synthesis and reactive oxygen species homeostasis. The LCA-driven alterations in the age-related dynamics of these vital mitochondrial processes extend yeast longevity. In sum, our findings suggest a mechanism underlying the ability of LCA to delay chronological aging in yeast by accumulating in both mitochondrial membranes and altering their glycerophospholipid compositions. We concluded that mitochondrial membrane lipidome plays an essential role in defining yeast longevity.

Burstein, Michelle T.; Bourque, Simon D.; Koupaki, Olivia; Juneau, Mylene; Feldman, Rachel; Iouk, Tatiana; Titorenko, Vladimir I.

2013-01-01

429

[Molecular mechanisms of peroxisome biogenesis in yeasts].  

PubMed

Peroxisomes contain oxidases generating hydrogen peroxide, and catalase degrading this toxic compound. Another characteristic function of each eukaryotic peroxisome, from yeast to man, is fatty acid beta-oxidation. However, in peroxisomes a variety of other metabolic pathways are located. In fungi, peroxisomes contain enzymes involved in catabolism of unusual carbon and nitrogen sources (methanol, purines, D-amino acids, pipecolynic acid, sarcosine, glycolate, spermidine etc) as well as biosynthesis of lysine in yeasts and penicillin in mycelial fungi. Impairment of peroxisomal structure and functions causes many human disorders. The similar defects have been identified in yeast mutants defective in peroxisomal biogenesis. Peroxisomal biogenesis is actively studied during last two decades using uni- and multicellular model systems. It was observed that many aspects of peroxisomal biogenesis and proteins involved in this process display striking similarity between all eukaryotes, from yeasts to humans. Yeast is a convenient model system for this kind of research. Current review summarizes data on molecular events of peroxisomal biogenesis, functions of peroxine proteins, import of peroxisomal matrix and membrane proteins and on mechanisms of peroxisomedivision and inheritance. PMID:22642098

Sibirny?, A A

430

Complete genome sequence analysis of Nocardia brasiliensis HUJEG-1 reveals a saprobic lifestyle and the genes needed for human pathogenesis.  

PubMed

Nocardia brasiliensis is an important etiologic agent of mycetoma. These bacteria live as a saprobe in soil or organic material and enter the tissue via minor trauma. Mycetoma is characterized by tumefaction and the production of fistula and abscesses, with no spontaneous cure. By using mass sequencing, we determined the complete genomic nucleotide sequence of the bacteria. According to our data, the genome is a circular chromosome 9,436,348-bp long with 68% G+C content that encodes 8,414 proteins. We observed orthologs for virulence factors, a higher number of genes involved in lipid biosynthesis and catabolism, and gene clusters for the synthesis of bioactive compounds, such as antibiotics, terpenes, and polyketides. An in silico analysis of the sequence supports the conclusion that the bacteria acquired diverse genes by horizontal transfer from other soil bacteria, even from eukaryotic organisms. The genome composition reflects the evolution of bacteria via the acquisition of a large amount of DNA, which allows it to survive in new ecological niches, including humans. PMID:23755230

Vera-Cabrera, Lucio; Ortiz-Lopez, Rocio; Elizondo-Gonzalez, Ramiro; Ocampo-Candiani, Jorge

2013-06-03

431

Evidence for prenatal transfer of rabies virus in the Mexican free-tailed bat (Tadarida brasiliensis Mexicana).  

PubMed

Fetuses were collected from four Mexican free-tailed bats (Tadarida brasiliensis mexicana) and a fetal bat cell (FBC) line was established and tested for its ability to support the replication of the ERA vaccine strain of rabies virus. Cytopathic effects were detected in ERA virus-inoculated as well as uninoculated FBC's. Immunofluorescent antibody testing of uninoculated FBC's provided no evidence for the presence of rabies virus. However, mice inoculated intracranially with supernatant fluid from uninoculated FBC's died. Enzyme-linked immunosorbent assay and immunofluorescent antibody testing revealed rabies virus in the brains of these mice. Tests with a panel of monoclonal antibodies indicated that the isolate was the same as that isolated from Mexican free-tailed bats from the southwestern United States. We conclude that the fetuses from which the FBC line was derived had been infected in utero with rabies virus. We believe this may represent the first observation of prenatal transfer of rabies virus in naturally infected bats. PMID:2668566

Steece, R S; Calisher, C H

1989-07-01

432

Acarine infracommunities associated with the Mexican free-tailed bat, Tadarida brasiliensis mexicana (Chiroptera: Molossidae) in arid regions of Mexico.  

PubMed

The Mexican free-tailed bat, Tadarida brasiliensis mexicana, is one of the most widely distributed bats, and its range includes the whole Mexican territory. Ectoparasites of this bat have been the subject of isolated reports, but no studies of its community ecology have been conducted. The acarine infracommunities associated with this bat were analyzed, comparing bat populations from three arid regions of Mexico: an abandoned factory in Nombre de Dios, Durango; a cave in Santiago, Nuevo León; and a church in Concepción del Oro, Zacatecas. The acarine infracommunity in Nuevo Le6n's bats exhibited the highest levels of diversity as reflected by a higher richness, a lower dominance, and a moderate and relatively homogeneous abundance in this locality in relation to the other two. This pattern is influenced by stable cave conditions relative to artificial habitats. Notwithstanding, further studies are required to determine whether or not different habitat conditions are a primary factor in the process of structuring the acari infracommunities. PMID:14765683

Guzmán-Cornejo, C; García-Prieto, L; Morales-Malacara, J B; Pérez-Ponce De León, G

2003-11-01

433

Opioid-like antinociceptive effects of oral administration of a lectin purified from the seeds of Canavalia brasiliensis.  

PubMed

The objective of this study was to evaluate the antinociceptive effects of a lectin from Canavalia brasiliensis (ConBr) when administered orally to murine models of chemical and thermal nociception. ConBr up to 100 mg/kg produced significant and dose-dependent antinociceptive effects: 81% reduction in abdominal writhing induced by 0.6% acetic acid; 26 and 52% reduction in early- and late-stage paw licking, respectively, induced by 2.5% formalin; and 155% increase in reaction latency (heightened thermal pain threshold). In all models, the antinociceptive effect was reversed by the lectin-binding carbohydrate ?-d-methyl-mannoside and by the nonselective opioid antagonist naloxone. The antinociceptive effect observed in the formalin test was inhibited by the ?-selective antagonist naltrindole and the ?-selective antagonist nor-binaltorphimine but not by the ?-selective antagonist cyprodime. In conclusion, when administered orally to Swiss mice, the ConBr lectin displayed antinociceptive activity, both peripheral and central, mediated by the opioid system and involving ?-and ?-receptors and the lectin domain. PMID:21895762

de Freitas Pires, Alana; Assreuy, Ana Maria Sampaio; Lopes, Érika Augusta Batista; Celedônio, Natália Rocha; Soares, Carlos Eduardo Alves; Rodrigues, Natália Velloso Fontenelle Camelo; Sousa, Paloma Leão; Benevides, Raquel Guimarães; Nagano, Celso Shiniti; Cavada, Benildo Sousa; Leal-Cardoso, José Henrique; Coelho-de-Souza, Andrelina Noronha; Santos, Cláudia Ferreira

2011-09-05

434

Agaricus bisporus and Agaricus brasiliensis (1?6)-?-D-glucans show immunostimulatory activity on human THP-1 derived macrophages.  

PubMed

The (1?6)-?-D-glucans from Agaricus bisporus and Agaricus brasiliensis were purified to evaluate their effects on the innate immune system. THP-1 macrophages were used to investigate the induction of the expression of TNF-?, IL1?, and COX-2 by RT-PCR. The purification of the polysaccharides gave rise to fractions containing 96-98% of glucose. The samples were analyzed by GC-MS, HPSEC and (13)C NMR, which confirmed the presence of homogeneous (1?6)-?-D-glucans. The ?-glucans were incubated with THP-1 derived macrophages, for 3 h and 6 h to evaluate their effects on the expression of pro-inflammatory genes. Both ?-glucans stimulated the expression of such genes as much as the pro-inflammatory control (LPS). When the cells were incubated with LPS+?-glucan, a significant inhibition of the expression of IL-1? and COX-2 was observed for both treatments after 3 h of incubation. By the results, we conclude that the (1?6)-?-D-glucans present an immunostimulatory activity when administered to THP-1 derived macrophages. PMID:23544515

Smiderle, Fhernanda R; Alquini, Giovana; Tadra-Sfeir, Michelle Z; Iacomini, Marcello; Wichers, Harry J; Van Griensven, Leo J L D

2013-01-16

435

Increased vascular permeability, angiogenesis and wound healing induced by the serum of natural latex of the rubber tree Hevea brasiliensis.  

PubMed

Increases in vascular permeability and angiogenesis are crucial events to wound repair, tumoral growth and revascularization of tissues submitted to ischemia. An increased vascular permeability allows a variety of cytokines and growth factors to reach the damaged tissue. Nevertheless, the angiogenesis supply tissues with a wide variety of nutrients and is also important to metabolites clearance. It has been suggested that the natural latex from Hevea brasiliensis showed wound healing properties and angiogenic activity. Thus, the purpose of this work was to characterize its angiogenic activity and its effects on vascular permeability and wound healing. The serum fraction of the latex was separated from the rubber with reduction of the pH. The activity of the dialyzed serum fraction on the vascular permeability injected in subcutaneous tissue was assayed according Mile's method. The angiogenic activity was determined using a chick embryo chorioallantoic membrane assay and its effects on the wound-healing proces