984 resultados para Large isoform of rubisco activase


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Recent studies indicated that Toxoplasma gondii isolates of many domestic animal hosts from Brazil are genetically and biologically different from those in USA and Europe. Despite of high pathogenicity of this parasite to small ruminants, the epidemiology and genetic diversity of T. gondii in these animals are not well understood in Brazil. In this study, a total of 28 T. gondii samples (16 isolates from sheep in Sao Paulo state, and 12 isolates from goats in the states of Sao Paulo and Rio Grande do Norte) were genotyped using genetic markers SAG1, SAG2, SAG3, BTUB, CRAG, c22-8, c29-2, L358, PK1, Apico and CS3. Eleven genotypes were identified from these T. gondii isolates. Eight isolates (4 from sheep and 4 from goats) were grouped into the common clonal type Brl lineage. One sheep isolate was grouped to the type BrIII lineage. Five isolates grouped to three previously identified genotypes in Brazil, and 13 isolates grouped to six novel genotypes. Mixed genotype was found in one isolate from goat in Sao Paulo. No classical clonal Type I. II or III isolates were found, confirming previous reports that these clonal lineages are rare in Brazil. The allele types at the CS3 locus are strongly linked to mouse virulence of the parasite. The results of this study indicate that even though a large number of T. gondii genotypes have been identified from a variety of animal hosts in Brazil, high percentage of new genotypes are continuously identified from different animal species, suggesting extremely high diversity of T. gondii in the population. (C) 2010 Elsevier B.V. All rights reserved.

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Objective. The aim of this study was to assess the effect of cigarette smoke inhalation (CSI) on gene expression in alveolar bone healing sites. Study design. Wistar rats were randomly assigned to the groups: control [animals not exposed to CSI (n = 20)] and test [animals exposed to CSI, starting 3 days before teeth extraction and maintained until killing them (n = 20)]. First mandibular molars were bilaterally extracted, and the expression of alkaline phosphatase, bone morphogenetic protein (BMP) 2 and 7, receptor activator of nuclear factor kappa B ligand, osteoprotegerin, and d2 isoform of vacuolar adenosine triphosphatase V(o) domain were assessed by quantitative polymerase chain reaction in the newly formed tissue in the sockets. Results. Overall, data analysis demonstrated that CSI significantly affected the expression pattern of all of the studied genes except BMP-7. Conclusion. The expression of key genes for bone healing may be affected by CSI in tooth extraction sites. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:447-452)

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Hydroxyapatite (HA), a stable and biocompatible material for bone tissue therapy, may present a variable stoichiometry and accept a large number of cationic substitutions. Such substitutions may modify the chemical activity of HA surface, with possible impact on biocompatibility. In this work, we assessed the effects of calcium substitution with diverse divalent cations (Pb(2+), Sr(2+), Co(2+), Zn(2+), Fe(2+), Cu(2+), or Mg(2+)) on the biological behavior of HA. Physicochemical analyses revealed that apatite characteristics related to crystallinity and calcium dissolution/uptake rates are very sensitive to the nature of cationic substitution. Cytocompatibility was evaluated by mitochondrial activity, membrane integrity, cell density, proapoptotic potential, and adhesion tests. With the exception of Zn-HA, all the substituted HAs induced some level of apoptosis. The highest apoptosis levels were observed for Mg-HA and Co-HA. Cu-HA was the only material to impair simultaneously mitochondrial activity, membrane integrity, and cell density. The highest relative cell densities after exposure to the modified HAs were observed for Mg-HA and Zn-HA, while Co-HA significantly improved cell adhesion onto HA surface. These results show that changes on surface dissolution caused by cationic substitution, as well as the increase of metal species released to biological media, were the main responsible factors related to alterations on HA biocompatibility. (C) 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 98A: 351-358, 2011.

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Background The continued increase in tuberculosis (TB) rates and the appearance of extremely resistant Mycobacterium tuberculosis strains (XDR-TB) worldwide are some of the great problems of public health. In this context, DNA immunotherapy has been proposed as an effective alternative that could circumvent the limitations of conventional drugs. Nonetheless, the molecular events underlying these therapeutic effects are poorly understood. Methods We characterized the transcriptional signature of lungs from mice infected with M. tuberculosis and treated with heat shock protein 65 as a genetic vaccine (DNAhsp65) combining microarray and real-time polymerase chain reaction analysis. The gene expression data were correlated with the histopathological analysis of lungs. Results The differential modulation of a high number of genes allowed us to distinguish DNAhsp65-treated from nontreated animals (saline and vector-injected mice). Functional analysis of this group of genes suggests that DNAhsp65 therapy could not only boost the T helper (Th)1 immune response, but also could inhibit Th2 cytokines and regulate the intensity of inflammation through fine tuning of gene expression of various genes, including those of interleukin-17, lymphotoxin A, tumour necrosis factor-cl, interleukin-6, transforming growth factor-beta, inducible nitric oxide synthase and Foxp3. In addition, a large number of genes and expressed sequence tags previously unrelated to DNA-therapy were identified. All these findings were well correlated with the histopathological lesions presented in the lungs. Conclusions The effects of DNA therapy are reflected in gene expression modulation; therefore, the genes identified as differentially expressed could be considered as transcriptional biomarkers of DNAhsp65 immunotherapy against TB. The data have important implications for achieving a better understanding of gene-based therapies. Copyright (C) 2008 John Wiley & Sons, Ltd.

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It has been established that large numbers of certain trees can survive in the beds of rivers of northeastern Australia where a strongly seasonal distribution of precipitation causes extreme variations in flow on both a yearly and longer-term basis. In these rivers, minimal flow occurs throughout much of any year and for periods of up to several years, allowing the trees to become established and to adapt their form in order to facilitate their survival in environments that experience periodic inundation by fast-flowing, debris-laden water. Such trees (notably paperbark trees of the angiosperm genus Melaleuca) adopt a reclined to prostrate, downstream-trailing habit, have a multiple-stemmed form, modified crown with weeping foliage, development of thick, spongy bark, anchoring of roots into firm to lithified substrates beneath the channel floor, root regeneration, and develop in flow-parallel, linear groves. Individuals from within flow-parallel, linear groves are preserved in situ within the alluvial deposit of the river following burial and death. Four examples of in situ tree fossils within alluvial channel deposits in the Permian of eastern Australia demonstrate that specialised riverbed plant communities also existed at times in the geological past. These examples, from the Lower Permian Carmila Beds, Upper Permian Moranbah Coal Measures and Baralaba Coal Measures of central Queensland and the Upper Permian Newcastle Coal Measures of central New South Wales, show several of the characteristics of trees described from modern rivers in northeastern Australia, including preservation in closely-spaced groups. These properties, together with independent sedimentological evidence, suggest that the Permian trees were adapted to an environment affected by highly variable runoff, albeit in a more temperate climatic situation than the modem Australian examples. It is proposed that occurrences of fossil trees preserved in situ within alluvial channel deposits may be diagnostic of environments controlled by seasonal and longer-term variability in fluvial runoff, and hence may have value in interpreting aspects of palaeoclimate from ancient alluvial successions. (C) 2001 Elsevier Science B.V. All rights reserved.

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The complete arrangement of genes in the mitochondrial (mt) genome is known for 12 species of insects, and part of the gene arrangement in the mt genome is known for over 300 other species of insects. The arrangement of genes in the mt genome is very conserved in insects studied, since all of the protein-coding and rRNA genes and most of the tRNA genes are arranged in the same way. We sequenced the entire mt genome of the wallaby louse, Heterodoxus macropus, which is 14,670 bp long and has the 37 genes typical of animals and some noncoding regions. The largest noncoding region is 73 bp long (93% A+T), and the second largest is 47 bp long (92% AST). Both of these noncoding regions seem to be able to form stem-loop structures. The arrangement of genes in the mt genome of this louse is unlike that of any other animal studied. All tRNA genes have moved and/or inverted relative to the ancestral gene arrangement of insects, which is present in the fruit fly Drosophila yakuba. At least nine protein-coding genes (atp6, atp8, cox2, cob, nad1-nad3, nad5, and nad6) have moved; moreover, four of these genes (atp6, atp8, nad1, and nad3) have inverted. The large number of gene rearrangements in the mt genome of H. macropus is unprecedented for an arthropod.

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A shortened version of the Interpersonal Sensitivity Measure (IPSM) developed to predict depression prone personalities was administered in a self-report questionnaire to a community-based sample of 3269 Australian twin pairs aged 18-28 years, along with Eysenck's EPQ and Cloninger's TPQ. The IPSM included four sub-scales: Separation Anxiety (SEP); Interpersonal Sensitivity (INT); Fragile Inner-Self (FIS); and Timidity (TIM). Univariate analysis revealed that individual differences in the IPSM sub-scale scores were best explained by additive genetic and specific environmental effects. Confirming previous research findings, familial aggregation for the EPQ and TPQ personality dimensions was entirely due to additive genetic effects. In the multivariate case, a model comprising additive genetic and specific environmental effects best explained the covariation between the latent factors for male and female twin pairs alike. The EPQ and TPQ dimensions accounted for moderate to large proportions of the genetic variance (40-76%) in the IPSM sub-scales, while most of the non-shared environment variance was unique to the IPSM sub-scales. (C) 2001 Elsevier Science Ltd. All rights reserved.

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Estimation of total body water by measuring bioelectrical impedance at a fixed frequency of 50 kHz is useful in assessing body composition in healthy populations. However, in cirrhosis, the distribution of total body water between the extracellular and intracellular compartments is of greater clinical importance. We report an evaluation of a new multiple-frequency bioelectrical-impedance analysis technique (MFBIA) that may quantify the distribution of total body water in cirrhosis. In 21 cirrhotic patients and 21 healthy control subjects, impedance to the Row of current was measured at frequencies ranging from 4 to 1012 kHz. These measurements were used to estimate body water compartments and then compared with total body water and extracellular water determined by isotope methodology. In cirrhotic patients, extracellular water and total body water (as determined by isotope methods) were well predicted by MFBIA (r = 0.73 and 0.89, respectively).;However, the 95% confidence intervals of the limits of agreement between MFBIA and the isotope methods were +/- 14% and +/-9% for cirrhotics (extracellular water and total body water, respectively) and +/-9% and +/-9% for cirrhotics without ascites. The 95% confidence intervals estimated from the control group were +/-10% and +/-5% for extracellular water and total body water, respectively. Thus, despite strong correlations between MFBIA and isotope measurements, the relatively large limits of agreement with accepted techniques suggest that the MFBIA technique requires further refinement before it can be routinely used to determine the nutritional assessment of individual cirrhotic patients. Nutrition 2001,17.31-34. (C)Elsevier Science Inc. 2001.

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Polarized absorption and emission spectra of trigonal single crystals of an Er(III) complex coordinated to a heptadentate tripodal ligand are reported at temperatures between 8 and 298 K. The assigned energy levels below the onset of ligand absorption (< 25 000 cm(-1)) are fitted to a parametrized electronic Hamiltonian. The C-3 site symmetry of the Er(HI) ion requires eight parameters for a full description of the ligand field within a one-electron operator description. This compound shows unusually large splittings of the multiplets, and the fitted parameters imply that this heptadentate ligand imparts the largest ligand field reported for an Er(III) complex. The ligand field was also interpreted within the angular overlap model (AOM). We derive the AOM matrix to include both sigma and anisotropic pi bonding and show that a useful description of the C-3 ligand field can be made using only five parameters. The success of the AOM description is encouraging for applications on isomorphous complexes within the lanthanide series and in describing the ligand field of low-symmetry complexes with less parameters than in the usual spherical harmonic expansion.

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Using the classical twin design, this study investigates the influence of genetic factors on the large phenotypic variance in inspection time (IT), and whether the well established IT-IQ association can be explained by a common genetic factor. Three hundred ninety pairs of twins (184 monozygotic, MZ; 206 dizygotic, DZ) with a mean age of 16 years participated, and 49 pairs returned approximately 3 months, later for retesting. As in many IT studies, the pi figure stimulus was used and IT was estimated from the cumulative normal ogive. IT ranged from 39.4 to 774.1 ms (159 +/- 110.1 ms) with faster ITs (by an average of 26.9 ms) found in the retest session from which a reliability of .69 was estimated. Full-scale IQ (FIQ) was assessed by the Multidimensional Aptitude Battery (MAB) and ranged from 79 to 145 (111 +/- 13). The phenotypic association between IT and FIQ was confirmed (- .35) and bivariate results showed that a common genetic factor accounted for 36% of the variance in IT and 32% of the variance in FIQ. The maximum likelihood estimate of the genetic correlation was - .63. When performance and verbal IQ (PIQ & VIQ) were analysed with IT, a stronger phenotypic and genetic relationship was found between PIQ and IT than with VIQ. A large part of the IT variance (64%) was accounted for by a unique environmental factor. Further genetic factors were needed to explain the remaining variance in IQ with a small component of unique environmental variance present. The separability of a shared genetic factor influencing IT and IQ from the total genetic variance in IQ suggests that IT affects a specific subcomponent of intelligence rather than a generalised efficiency. (C) 2001 Elsevier Science Inc. All rights reserved.

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Questionnaire surveys, while more economical, typically achieve poorer response rates than interview surveys. We used data from a national volunteer cohort of young adult twins, who were scheduled for assessment by questionnaire in 1989 and by interview in 1996-2000, to identify predictors of questionnaire non-response. Out of a total of 8536 twins, 5058 completed the questionnaire survey (59% response rate), and 6255 completed a telephone interview survey conducted a decade later (73% response rate). Multinomial logit models were fitted to the interview data to identify socioeconomic, psychiatric and health behavior correlates of non-response in the earlier questionnaire survey. Male gender, education below University level, and being a dizygotic rather than monozygotic twin, all predicted reduced likelihood of participating in the questionnaire survey. Associations between questionnaire response status and psychiatric history and health behavior variables were modest, with history of alcohol dependence and childhood conduct disorder predicting decreased probability of returning a questionnaire, and history of smoking and heavy drinking more weakly associated with non-response. Body-mass index showed no association with questionnaire non-response. Despite a poor response rate to the self-report questionnaire survey, we found only limited sampling biases for most variables. While not appropriate for studies where socioeconomic variables are critical, it appears that survey by questionnaire, with questionnaire administration by telephone to non-responders, will represent a viable strategy for gene-mapping studies requiring that large numbers of relatives be screened.

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Despite a large number of T cells infiltrating the liver of patients with chronic hepatitis B, little is known about their complexity or specificity. To characterize the composition of these T cells involved with the pathogenesis of chronic hepatitis B (CHB), we have studied the clonality of V beta T cell receptor (TCR)-bearing populations in liver tissue by size spectratyping the complementarity-determining region (CDR3) lengths of TCR transcripts. We have also compared the CDR3 profiles of the lymphocytes infiltrating the liver with those circulating in the blood to see whether identical clonotypes may be detected that would indicate a virus-induced expansion in both compartments. Our studies show that in most of the patients examined, the T cell composition of liver infiltrating lymphocytes is highly restricted, with evidence of clonotypic expansions in 4 to 9 TCR V beta subfamilies. In contrast, the blood compartment contains an average of 1 to 3 expansions. This pattern is seen irrespective of the patient's viral load or degree of liver pathology. Although the TCR repertoire profiles between the 2 compartments are generally distinct, there is evidence of some T cell subsets being equally distributed between the blood and the liver. Finally, we provide evidence for a putative public binding motif within the CDR3 region with the sequence G-X-S, which may be involved with hepatitis B virus recognition.

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Flash vacuum thermolysis of a large variety of heterocyclic compounds is a useful means of production of ketenes, ketenimines, thioketenes, allenes, iminopropadienones, bis(imino)propadienes, iminopropadienethiones, carbodiimides, isothiocyanates, acetylenes, fulminic acid, nitrile imines and nitrile ylides, nitriles, cyanamides, cyanates, and other compounds, often in preparatively useful yields.

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This paper examines a range of theoretical issues and the empirical evidence relating to clinical supervision in four mental health professions, namely clinical psychology, occupational therapy, social work, and speech pathology. Despite the widespread acceptance of the value of supervision among practitioners and the large quantity of literature on the topic, there is very little empirical evidence in this area. It is not clear whether supervision actually produces a change in clinician behaviour, nor whether it produces benefits in terms of client outcomes. To date, there is insufficient evidence to demonstrate which styles of supervision are most beneficial for particular types of staff, in terms of their level of experience or learning style. The data suggest that directive forms of supervision, rather than unstructured approaches, are preferred by relatively inexperienced practitioners, and that experienced clinicians also value direct supervision methods when learning new skills or dealing with complex or crisis situations. The available evidence suggests that supervisors typically receive little training in supervision methods. However, to date, we have little information to guide us as to the most effective ways of training supervisors. While acknowledging the urgent need for research, the paper concludes that supervision is likely to form a valuable component of professional development for mental health professionals.

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Primary infection with the human herpesvirus, Epstein-Barr virus (EBV), may result in subclinical seroconversion or may appear as infectious mononucleosis (IM), a lymphoproliferative disease of variable severity. Why primary infection manifests differently between patients is unknown, and, given the difficulties in identifying donors undergoing silent seroconversion, little information has been reported. However, a longstanding assumption has been held that IM represents an exaggerated form of the virologic and immunologic events of asymptomatic infection. T-cell receptor (TCR) repertoires of a unique cohort of subclinically infected patients undergoing silent infection were studied, and the results highlight a fundamental difference between the 2 forms of infection. In contrast to the massive T-cell expansions mobilized during the acute symptomatic phase of IM, asymptomatic donors largely maintain homeostatic T-cell control and peripheral blood repertoire diversity. This disparity cannot simply be linked to severity or spread of the infection because high levels of EBV DNA were found in the blood from both types of acute infection. The results suggest that large expansions of T cells within the blood during IM may not always be associated with the control of primary EBV infection and that they may represent an overreaction that exacerbates disease. (C) 2001 by The American Society of Hematology.