RESUMO
Biodiversity loss is mainly driven by human activity. While concern grows over the fate of hot spots of biodiversity, contemporary species losses still prevail in industrialized nations. Therefore, strategies were formulated to halt or reverse the loss, driven by evidence for its value for ecosystem services. Maintenance of the latter through conservation depends on correctly identified species. To this aim, the German Federal Ministry of Education and Research is funding the GBOL project, a consortium of natural history collections, botanic gardens, and universities working on a barcode reference database for the country's fauna and flora. Several noticeable findings could be useful for future campaigns: (i) validating taxon lists to serve as a taxonomic backbone is time-consuming, but without alternative; (ii) offering financial incentives to taxonomic experts, often citizen scientists, is indispensable; (iii) completion of the libraries for widespread species enables analyses of environmental samples, but the process may not hold pace with technological advancements; (iv) discoveries of new species are among the best stories for the media; (v) a commitment to common data standards and repositories is needed, as well as transboundary cooperation between nations; (vi) after validation, all data should be published online via the BOLD to make them searchable for external users and to allow cross-checking with data from other countries.
Assuntos
Biodiversidade , Código de Barras de DNA Taxonômico , Bases de Dados Genéticas , Animais , Países Desenvolvidos , Alemanha , Fidelidade a Diretrizes , Humanos , Cooperação Internacional , Bibliotecas , Reprodutibilidade dos TestesRESUMO
The control of stored-product moths in bagged commodities is difficult because the developmental stages of the moths are protected by the bagging material from control measures such as the application of contact insecticides. Studies were carried out to assess the ability of Hymenopteran parasitoids to locate their hosts inside jute bags in the laboratory. The ability of different parasitoids to penetrate jute bags containing rice was investigated in a controlled climate chamber. Few Habrobracon hebetor (Say) (Hymenoptera: Braconidae) passed through the jute material while a high percentage of Lariophagus distinguendus (Förster), Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae) and Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) were able to enter the Petri-dishes. Significantly more L. distinguendus and T. elegans entered compared to H. hebetor. There was significant difference in the mean percentage parasitoids invading depending on species. Head capsules and/or thorax widths were measured in order to determine whether the opening in the jute material would be large enough for entry of the parasitoids. These morphometric data differed depending on parasitoid species and sex. The parasitoid Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae) did not enter the bags, but located host larvae inside the jute bags and parasitized rice moths Corcyra cephalonica larvae by stinging through the jute material. Venturia canescens significantly reduced the number of C. cephalonica adults emerging from the bagged rice; therefore, it could be released in storage rooms containing bagged rice for biological control of C. cephalonica. The use of parasitoids to suppress stored-product insect pests in bagged commodities could become a valuable supplement to the use of synthetic pesticides.
Assuntos
Besouros/parasitologia , Mariposas/parasitologia , Controle Biológico de Vetores/métodos , Vespas/fisiologia , Animais , Pesos e Medidas Corporais , Corchorus , Embalagem de Alimentos , Vespas/anatomia & histologiaRESUMO
Our Solar System was formed from a cloud of gas and dust. Most of the dust mass is contained in amorphous silicates, yet crystalline silicates are abundant throughout the Solar System, reflecting the thermal and chemical alteration of solids during planet formation. (Even primitive bodies such as comets contain crystalline silicates.) Little is known about the evolution of the dust that forms Earth-like planets. Here we report spatially resolved detections and compositional analyses of these building blocks in the innermost two astronomical units of three proto-planetary disks. We find the dust in these regions to be highly crystallized, more so than any other dust observed in young stars until now. In addition, the outer region of one star has equal amounts of pyroxene and olivine, whereas the inner regions are dominated by olivine. The spectral shape of the inner-disk spectra shows surprising similarity with Solar System comets. Radial-mixing models naturally explain this resemblance as well as the gradient in chemical composition. Our observations imply that silicates crystallize before any terrestrial planets are formed, consistent with the composition of meteorites in the Solar System.
RESUMO
By using a biotinylated ligand and Western blotting techniques, a receptor (RFc alpha) and a binding factor (BF) for IgA were detected, respectively, on membrane and in the cell-free culture supernatant of rat peritoneal macrophages. Extraction of the RFc alpha was obtained by solubilization of macrophages with Nonidet P-40, and purification was performed by HPLC affinity chromatography on a column derivatized with IgA. RFc alpha is formed of two subunits, with molecular masses of 56 and 70 kDa, which are both involved in the IgA binding ability of rat peritoneal macrophages. IgABF was recovered from the cell-free supernatant of a short-term culture of rat macrophages and was affinity-purified in the same manner as RFc alpha. Like RFc alpha, IgABF retained its IgA binding activity in its native, as well as denatured form. Since the molecular masses of RFc alpha and IgABF are similar, and IgABF competes with RFc alpha for IgA binding, one can assume that IgABF probably represents a shed RFc alpha.
Assuntos
Linfocinas/isolamento & purificação , Macrófagos/imunologia , Proteínas Secretadas pela Próstata , Receptores Fc/isolamento & purificação , Animais , Líquido Ascítico/citologia , Biotina , Western Blotting , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Detergentes , Imunoglobulina A/metabolismo , Imunoglobulina A/farmacologia , Peso Molecular , Octoxinol , Polietilenoglicóis , Ratos , Ratos Endogâmicos , SolubilidadeRESUMO
A series of expression vectors has been constructed as based on the pML derivative of pBR322. The eukaryotic transcription units employ various promoters followed by polycloning sites for 3-9 commonly used restriction enzymes and are completed by the SV40 polyadenylation sequence. In 4 of the vectors, designed for co-transfection or transient expression studies, only a single transcription unit containing either a constitutive or an inducible promoter was incorporated. The human ubiquitin (UbC) promoter was used as a strong constitutive promoter, while the mouse metallothionein promoter and the promoter of the long terminal repeats of the mouse mammary tumor virus were used as inducible promoters. Another vector contained an additional transcription unit encoding a eukaryotic selection marker, the neomycin resistance encoding gene. The vectors were used in CHO cells and in neuroendocrine CA77 cells to synthesize peptide precursors, protease inhibitors and a protease. It is shown that these vectors are very efficient for the constitutive and inducible expression of nucleotide sequences in both transient and stable transfections of eukaryotic cells.
Assuntos
Células/metabolismo , Células Eucarióticas/metabolismo , Regulação da Expressão Gênica , Vetores Genéticos , Biossíntese Peptídica , Inibidores de Proteases/análise , Precursores de Proteínas/biossíntese , Proteínas Recombinantes/biossíntese , Animais , Sequência de Bases , Humanos , Dados de Sequência Molecular , Plasmídeos , Regiões Promotoras Genéticas , Precursores de Proteínas/genética , Transcrição Gênica/fisiologia , TransfecçãoRESUMO
Dextransucrase of Streptococcus sanguis occurred in cell-free and cell-associated forms. Cell-free dextransucrase was purified by four successive chromatographies on Bio-Gel P 60, DEAE-cellulose, and Bio-Gel P 200 from the culture supernatant. The purification of cell-associated dextransucrase was made from the pellet of Streptococcus sanguis culture. Bacterial pellet was extracted with 1 M phosphate buffer (pH 6.0) and chromatographied by using an immunosorbent column. The two enzymes gave single bands in polyacrylamide gel electrophoresis. The molecular weight determined by sodium dodecyl sulfate polyacrylamide gel was about 100 000 daltons for the two forms of dextransucrases. The optimum pH of the cell-free and cell-associated enzymes was around 6 and the temperature optimum was broad for the two enzymes. The KM values for sucrose were respectively 2 mM and 3 mM for cell-free and cell-associated enzymes. When primer dextran was added, the reaction velocity increased but the KM for sucrose remained the same, and the KA for dextran was 200 muM for the two dextransucrases. Trehalose and maltose acted also as glucosyl residue acceptors. Purified enzymes had dextran synthesising activity and invertase-like activity. The same properties of the two forms of enzymes and the positive cross reaction against anti free and anti cell-associated globulins stongly suggest the identity of the two enzymes.
Assuntos
Glucosiltransferases , Streptococcus sanguis/enzimologia , Cromatografia em Gel , Cromatografia por Troca Iônica , Reações Cruzadas , Citosol/enzimologia , Dextranos/metabolismo , Eletroforese em Gel de Poliacrilamida , Glucosiltransferases/isolamento & purificação , Glucosiltransferases/metabolismo , Concentração de Íons de Hidrogênio , Técnicas de Imunoadsorção , Cinética , Peso Molecular , Streptococcus mutans/enzimologia , SacaraseRESUMO
⢠We investigated the effect of an optimal nutrition strategy designed to maximize loblolly pine (Pinus taeda) growth on the rank abundance structure and diversity of associated basidiomycete communities. ⢠We conducted both small- and large-scale below-ground surveys 10 years after the initiation of optimal nutrition, and used TRFLP of selectively PCR-amplified nrDNA ITS to determine the distribution and abundance of macrofungal basidiomycete species in c. 200 soil samples collected from optimally fertilized and unfertilized treatments at the SETRES loblolly pine experimental site, North Carolina, USA. ⢠Our results indicated an increased relative abundance of Tylopilus and Thelephora spp. on optimally fertilized stands. Our results also suggested improved mycelial growth of several species, possibly caused by increased connectivity in the forest floor as a result of increased plant growth. ⢠In addition, our results suggest a trend towards reduced basidiomycete diversity, and that large-scale application of optimal nutrition may need to be sensitive to increased nitrate availability.
RESUMO
The nucleotide sequence encoding the SR protein of Streptococcus mutans OMZ 175 (serotype f) has been determined. The sr gene consists of 4667 bp and codes for a 171177 Da protein. Comparison of the inferred amino acid sequence with the one of PAc antigen from S. mutans MT 8148 (serotype c) indicates a 88% conservation of amino acid residues which reflects the close relatedness of both proteins. Major differences in amino acid composition are located at the C-terminal part of the sequence where only 298 amino acids of the terminal 420 are conserved.
Assuntos
Proteínas de Bactérias/genética , Genes Bacterianos , Streptococcus mutans/genética , Sequência de Aminoácidos , Sequência de Bases , DNA Bacteriano/genética , Dados de Sequência Molecular , Peso Molecular , Mapeamento por Restrição , Homologia de Sequência do Ácido NucleicoRESUMO
Besides mites, filamentous fungi and yeasts play an important role as domestic allergens. Among different allergen avoidance strategies the efficacy of synthetic mattress encasings has been demonstrated for the reduction of house dust mites. Whether these synthetic encasings are also able to reduce the growth of fungi on the mattress under domestic conditions has not been assessed so far. To determine if the fungal growth on mattresses can be reduced by the use of synthetic encasings we assessed the fungal colonisation of mattresses covered either by conventional cotton encasings or by polyurethane encasings impermeable to particles > 3 mum. Within a 12-month period dust samples were obtained from the mattresses. Fungal quantities were measured by counting colonies on agar plates incubated at 20 degrees C and 37 degrees C. The counts of fungi were significantly higher on mattresses with cotton encasings. Penicillium spp. and Aspergillus spp. were isolated most frequently. Therefore the application of synthetic encasings with similar properties to the encasings used in this investigation is recommended as part of an allergen avoidance strategy for patients sensitised to fungal allergens.
Assuntos
Asma/etiologia , Leitos/microbiologia , Fungos/isolamento & purificação , Leveduras/isolamento & purificação , Adulto , Alérgenos/efeitos adversos , Animais , Poeira/efeitos adversos , Meio Ambiente , Feminino , Gossypium/efeitos adversos , Humanos , Masculino , ÁcarosRESUMO
Human mature enamel proteins were prepared by a combination of three extraction procedures in the presence or absence of de-aggregating agents before and after EDTA demineralization. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of a single low mol. wt protein in the water extract and multicomponent proteins with high mol. wt in the urea and urea-EDTA extracts. Polyacrylamide gel electrophoresis of the proteins contained in the three fractions after reduction and alkylation showed the existence of the two last fractions of different constitutive monomers linked by covalent and non-covalent bonds. Immunological comparison of the proteins showed at least one common protein in the E2 and E3 fractions. It is suggested that the high mol. wt proteins observed in mature enamel matrix were formed by combination of different monomers.
Assuntos
Proteínas do Esmalte Dentário/análise , Adolescente , Adulto , Aminoácidos/análise , Fracionamento Químico , Solubilidade do Esmalte Dentário , Eletroforese em Gel de Poliacrilamida , Humanos , Imunodifusão , Peso MolecularRESUMO
The saliva interacting protein (74KSR) from Streptococcus mutans serotype f, which is immunologically related to antigen I/II from serotype c, also termed B, P1, PAc, is probably involved in the adherence process of Strep. mutans to the tooth surface. A solid-phase adherence assay showed that 38% of the binding of salivary glycoproteins to Strep. mutans OMZ175 was due to this protein. We have cloned and sequenced the 74KSR gene (sr), which produces a recombinant protein (rec195K) with a relative molecular mass of 195,000, as estimated by SDS-PAGE. The strong immunological relationship and functional identity of the 74KSR and rec195K indicate that the Mr 195K protein is probably a precursor form, post-translationally processed, of the 74KSR produced in Strep. mutans. The gene sr consists of 4667 bp and codes for a 171,177 Mr protein. Biochemical features of the protein (density in proline residues and hydrophobicity) may explain the difference observed between the SDS-PAGE estimated molecular mass of the immature protein and the one deduced from the nucleotide sequence. Intra-species hybridization experiments using three contiguous restriction fragments isolated from gene sr as probes showed that the sequence is highly similar in strains from serotypes c and e. We have also shown that a fraction of the heart specific antibodies induced in rabbits during immunization with the 74KSR or rec195K reacts predominantly with human IgG and suggest the hypothesis of antigen mimicry as an explanation for the production of anti-IgG autoantibodies. It will be of great importance to identify the cross-reactive epitopes within the molecule before considering its use in protective immunization against oral streptococci.
Assuntos
Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Genes Bacterianos/genética , Glicoproteínas/química , Proteínas e Peptídeos Salivares/química , Streptococcus mutans/genética , Sequência de Aminoácidos , Antígenos de Superfície/genética , Proteínas de Bactérias/química , Clonagem Molecular , DNA Bacteriano/genética , Dados de Sequência Molecular , Ligação Proteica , Streptococcus mutans/classificaçãoRESUMO
Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment for neonates who have severe respiratory failure that does not respond to maximal conventional therapy. A consequence of venoarterial ECMO is the sacrifice of the right common carotid artery. Evaluation of the impact of a single carotid artery in babies treated with ECMO concerns mostly long-term neurodevelopmental outcome. The authors encountered a peculiar problem caused by a single carotid artery in a post-ECMO patient during the surgical correction of aortic coarctation with hypoplastic distal aortic arch. For patients with a confirmed cardiac malformation that necessitates future surgical repair and for whom ECMO support is required, reconstruction of the right common carotid artery should be considered. Veno-venous ECMO is an alternative solution if this approach is not contraindicated because of the patient's clinical condition. Patients with congenital diaphragmatic hernia have a higher incidence of cardiac malformations; therefore, careful cardiological attention is required. Anomalies masked by pulmonary hypertension also must be considered.
Assuntos
Coartação Aórtica/cirurgia , Oxigenação por Membrana Extracorpórea/efeitos adversos , Hérnia Diafragmática/terapia , Coartação Aórtica/etiologia , Hérnias Diafragmáticas Congênitas , Humanos , Recém-Nascido , MasculinoRESUMO
The nematophagous fungus Arthrobotrys oligospora Fres. can live saprophytically as well as predatorily. As a predator it forms sticky reticulate traps in the presence of living nematodes which enable it to kill and consume the animals. In laboratory experiments the nutrient acquisition of the fungus was tested on agar media with various N- and C-sources in different concentrations. The intensity of predacious response was determined by counting the traps formed on the agar surface after induction by nematodes. Predacious activity (PA) served as a unit of the strength of nematophagous response. PA was defined as the number of traps/100 mm2. In contrast to carnivorous higher plants, which consume insects in order to compensate their N-deficit, the fungus seems to kill nematodes to get both, N as well as C. If the agar substrate contains a certain concentration of N and C, the fungus does not form traps and lives as a saprophyte. The level which determines the switch towards pure saprophytism under laboratory conditions ranges around 0.12 M C at a N-concentration of 0.05 M. If no nitrogen is added to the medium the fungus forms nematode-induced traps even in the most concentrated C-media. On N-media without any carbon source the fungus shows a much stronger PA compared with N-free media. Furthermore, more chlamydospores were formed on N-media.
Assuntos
Fungos Mitospóricos/fisiologia , Nematoides , Animais , Meios de CulturaRESUMO
Parthenium weed (Parthenium hysterophorus L., family Asteraceae), an annual herb of neotropic origin, is an invasive noxious weed with a pantropical distribution (1). It is particularly undesirable because of the serious health risks it poses to people living close to infestations (1). In January 1995, S. Neser (ARC-Plant Protection Research Institute, Pretoria, South Africa) collected a rust fungus on this plant near Brits, Northwest Province, South Africa (25°35'S, 27°46'E). Only uredinia were present. The same rust fungus was collected in the same area in January, March, and June of 2001, and again only uredinia were observed. In its native range, P. hysterophorus is infected by two rust fungus species, Puccinia abrupta Diet. & Holw. var. partheniicola (Jackson) Parmelee and Puccinia melampodii Diet. & Holw., but the latter species is microcyclic with telia only. The morphology of the urediniospores in the South African collections corresponds to Puccinia abrupta var. partheniicola (3): obovoid to almost triangular, 22 to 27 × 18 to 25 µm, echinulate, two subequatorial and one apical germ pores, spines absent around germ pores, wall 1 to 2.5 µm thick. The native range of Puccinia abrupta var. partheniicola is Mexico and northern South America (3). In addition, it has been recorded from Mauritius (3), Kenya, and India (H. C. Evans and C. A. Ellison, International Institute of Biological Control, CAB, 1987, unpublished data). It was intentionally introduced into Australia for the biological control of P. hysterophorus (2). Thirteen specimens in the Arthur Herbarium were examined, and only two had telia in addition to uredinia. The other 11 had only uredinia, indicating that nonformation of telia is common. Telia and uredinia are produced in high altitude, semiarid areas of Mexico, whereas in low altitude, more humid areas only uredinia are produced (1). The production of telia appears to depend on environmental conditions, and their absence is not unexpected at the Brits site, which is a high altitude (1,120 m) area with high summer rainfall (400 to 600 mm per year from November to February) and dry winters. Voucher specimens were deposited at the National Collection of Fungi, Plant Protection Research Institute, Pretoria (PREM 57298) and the Arthur Herbarium, West Lafayette, IN (PUR N1117). To our knowledge, this is the second report of this rust fungus in Africa and the first in southern Africa. References: (1) H. C. Evans. Trans. Br. Mycol. Soc. 88:105, 1987. (2) A. Parker et. al. Plant Pathol. 43:1, 1994. (3) J. A. Parmelee. Can. J. Bot. 45:2267, 1967.
RESUMO
English daisy (Bellis perennis, family Asteraceae) is a flowering plant native to Europe. It is widely used as an ornamental in North America but is also a weed in lawns in the western and eastern United States. In December 2000, plants growing in urban landscapes in Monterey County, CA, were infected with rust. Orange aecia containing aeciospores that measured 14 to 18 × 12.5 to 15 µm developed profusely on leaves. Severely diseased leaves wilted and collapsed. Other spore states (pycnia, uredosori, and telia) were not observed. Based on the size and ornamentation of the aeciospores, reduced white peridium, apperance of the peridial cells, and arrangement of sori, we identified the pathogen as Puccinia lagenophorae Cooke (1,3), a rust fungus native to Australia and New Zealand that since 1960 has been introduced to other continents (2). On English daisy, the disease has been reported only in Australia and Europe (1). The pathogen also occurs on numerous other plants of the subfamily Asteroideae (family Asteraceae) (2). The occurrence of P. lagenophorae on English daisy follows the recent, first-time detection of the same pathogen on common groundsel (Senecio vulgaris) in California (3). To test cross infectivity, a spore suspension of a rust isolate from common groundsel was prepared and applied to various ornamental plants known to be hosts of P. lagenophorae. Inoculated plants were kept in a humidity chamber for 48 h, then maintained in a greenhouse. After 9 to 14 days, aecia developed on English daisy, cineraria (S. cruentus), and common groundsel but did not develop on dusty miller (S. cineraria) or pot marigold (Calendula officinalis). In addition, a single telium, surrounded by aecia, was observed on one of the infected English daisy plants. The telium contained two-celled teliospores that measured 31 to 36.5 × 16 to 19 (-22) µm and one-celled mesospores that measured 22 to 34 × 13.5 to 16 µm. At point of attachment, the widths of the stalks measured 7 to 8.5 (-9.5) µm. Some of the spores had surface ridges. The morphological features of the telio- and mesospores agree with those described for P. lagenophorae. To the authors' knowledge, this is the first record of a rust fungus on English daisy in North America. The inoculation experiments indicated that the rusts on English daisy and common groundsel are not biologically separated, casting doubt on the taxonomic concept of Weber et al. (4) that considered the rust on English daisy to be a distinct species, P. distincta McAlpine (although they did not examine type material of either P. lagenophorae or P. distincta). References: (1) M. Scholler. Sydowia 49:174, 1997. (2) M. Scholler. J. Plant Dis. Prot. 105:239, 1998. (3) M. Scholler and S. T. Koike. Plant Dis. 85:335, 2001. (4) R. W. S. Weber et al. Mycol. Res. 102:1227, 1998.
RESUMO
Common groundsel (Senecio vulgaris, Asteraceae) is native to Europe and is now a common weed mainly in disturbed habitats of almost worldwide distribution. In November 2000, groundsel plants growing adjacent to lettuce fields in California's coastal Salinas Valley (Monterey County) showed symptoms of rust. In a 0.2-ha survey area, 75% of the plants were infected. Examination of weeds growing in four residential blocks also uncovered infected groundsel. Densely clustered, orange aecia were observed on leaves and stems. Stems were swollen where aecia had formed. Blossom and fruit formation was not notably reduced, although some involucral bracts were infected. Aeciospores measured 14 to 18 µm × 12.5 to 15 µm (fresh material). Telia were not found. The pathogen was identified as Puccinia lagenophorae Cooke, a rust fungus that is native to Australia and New Zealand and infects plants of the subfamily Asteroideae (family Asteraceae) (3). P. lagenophorae is an autoecious species forming only repeating aecia (stage I) and telia (stage III). There are six other rusts of Senecio that occur in the United States (1) that readily form aecia but not telia on Senecio spp. When only aecia are observed on Senecio, which is typical for P. lagenophorae (2), the following features can be used to differentiate it from these other species: no pycnia (stage 0) are formed; aecia are formed repeatedly; systemic growth that results in deformation of the host, including formation of galls with dense clusters of aecia on the stem; poorly developed aecial peridium; and aeciospores small, measuring 12.5 to 18.5 µm × 10.0 to 16.0 µm (4). In addition, P. lagenophorae forms aecia even at the end of the year in northern temperate zones, whereas heteroecious species form aecia only in spring and early summer (2). This is the first record of P. lagenophorae in North America. Specimens were deposited in the Arthur Herbarium, Purdue University. Outside its native habitat, this fungus has been found in Europe, Africa, the Middle East, and South America. There are about 60 known host species of P. lagenophorae (3) including ornamentals such as Bellis perennis, Calendula officinalis, and Senecio cruentus. The pathogen may have been introduced to North America via land from South America through Central America, or by the importation of ornamentals that were either infected with rust or infested with diseased groundsel. References: (1) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN. (2) M. Scholler. Regensb. Myk. Schr. 6:1, 1996. (3) M. Scholler. J. Plant Dis. Prot. 105:239, 1998. (4) I. Wilson et al. Trans. Brit. Mycol. Soc. 48:501, 1965.
Assuntos
Óxido Nítrico/biossíntese , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/toxicidade , Streptococcus mutans/patogenicidade , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Parede Celular/química , GMP Cíclico/metabolismo , Indução Enzimática/efeitos dos fármacos , Técnicas In Vitro , Lipopolissacarídeos/toxicidade , Óxido Nítrico Sintase/biossíntese , Ratos , Choque Séptico/etiologia , Choque Séptico/fisiopatologia , Streptococcus mutans/química , Vasoconstrição/efeitos dos fármacosRESUMO
BACKGROUND/PURPOSE: Toxoplasmosis is the most common cause of posterior uveitis in immunocompetent subjects. Taking into account the opposing needs of limiting parasite multiplication and minimizing tissue destruction, the infection imbalance most often involves CD4 and CD8 T lymphocytes that play the lead role in adaptive immunity to T. gondii. The aims of our study were to develop murine models of toxoplasmosis and to study the immune responses to the infection. METHODS: Two murine models were studied: (i) intravitreal injection of T. gondii (primary infection) and (ii) intraperitoneal inoculation at birth and reinfection by intravitreal injection. Clinical and histological data were determined. mRNA-cytokine levels were measured in ocular samples obtained from mice with toxoplasma chorioretinitis using RT-PCR. RESULTS: Intravitreal injection of T. gondii led to chorioretinitis. Primary infection was characterized by severe chorioretinitis when compared with reinfection. mRNA levels of IFN-gamma, TNF-alpha, and iNOS were increased in infected mice. DISCUSSION: TH1 cells may mitigate chorioretinitis by limiting T. gondii proliferation. Further studies are needed to explore ocular immune regulation. These primary results may open new in vivo therapeutic approaches.
Assuntos
Coriorretinite/imunologia , Coriorretinite/parasitologia , Modelos Animais de Doenças , Toxoplasmose Ocular/imunologia , Animais , Coriorretinite/genética , Perfilação da Expressão Gênica , Camundongos , Toxoplasmose Ocular/genéticaRESUMO
An anti-glucosyltransferase serum was prepared against a purified enzyme of Streptococcus sanguis OMZ 9. Antibody fractions obtained after gel filtration on a Bio-Gel P200 column were used to study enzyme-antibody interaction in broth culture containing either sucrose or glucose, and to localize ultrastructurally the enzyme on thin sections of bacteria using labelled and unlabelled antibodies. The antibody fractions had no effect on bacterial growth in broth culture. A strong inhibition of insoluble and soluble polysaccharides synthesis was obtained in batch culture after a 24 hours incubation of bacteria with rides synthesis was obtained in batch culture after a 24 hours incubation of bacteria with antibodies. The GTF was localized at different cellular levels on bacteria grown in glucose but the ultrastructural method failed to localize GTF in sucrose grown cells.