Causes and consequences of variation in nestling immune function

Defence against pathogens is a vital need of all living organisms that has led to the evolution of complex immune mechanisms. However, although immunocompetence the ability to resist pathogens and control infection has in recent decades become a focus for research in evolutionary ecology, the variation in immune function observed in natural populations is relatively little understood. This thesis examines sources of this variation (environmental, genetic and maternal effects) during the nestling stage and its fitness consequences in wild populations of passerines: the blue tit (Cyanistes caeruleus) and the collared flycatcher (Ficedula albicollis). A developing organism may face a dilemma as to whether to allocate limited resources to growth or to immune defences. The optimal level of investment in immunity is shaped inherently by specific requirements of the environment. If the probability of contracting infection is low, maintaining high growth rates even at the expense of immune function may be advantageous for nestlings, as body mass is usually a good predictor of post-fledging survival. In experiments with blue tits and haematophagous hen fleas (Ceratophyllus gallinae) using two methods, methionine supplementation (to manipulate nestlings resource allocation to cellular immune function) and food supplementation (to increase resource availability), I confirmed that there is a trade-off between growth and immunity and that the abundance of ectoparasites is an environmental factor affecting allocation of resources to immune function. A cross-fostering experiment also revealed that environmental heterogeneity in terms of abundance of ectoparasites may contribute to maintaining additive genetic variation in immunity and other traits. Animal model analysis of extensive data collected from the population of collared flycatchers on Gotland (Sweden) allowed examination of the narrow-sense heritability of PHA-response the most commonly used index of cellular immunocompetence in avian studies. PHA-response is not heritable in this population, but is subject to a non-heritable origin (presumably maternal) effect. However, experimental manipulation of yolk androgen levels indicates that the mechanism of the maternal effect in PHA-response is not in ovo deposition of androgens. The relationship between PHA-response and recruitment was studied for over 1300 collared flycatcher nestlings. Multivariate selection analysis shows that it is body mass, not PHA-response, that is under direct selection. PHA-response appears to be related to recruitment because of its positive relationship with body mass. These results imply that either PHA-response fails to capture the immune mechanisms that are relevant for defence against pathogens encountered by fledglings or that the selection pressure from parasites is not as strong as commonly assumed.

Nuclear matrix of the most primitive eukaryote Archezoa

Accumulating evidence suggests that unicellular Archezoa are the most primitive eukaryotes and their nuclei are of significance to the study of evolution of the eukaryotic nucleus. Nuclear matrix is an ubiquitous important structure of eukaryotic nucleus; its evolution is certainly one of the most important parts of the evolution of nucleus. To study the evolution of nuclear matrix, nuclear matrices of Archezoa are investigated. Giardia lamblia cells are extracted sequentially. Both embedment-free section EM and whole mount cell EM of the extracted cells show that, like higher eukaryotes, this species has a residual nuclear matrix in its nucleus and rich intermediate filaments in its cytoplasm, and the two networks connect with each other to form a united network. But its nuclear matrix does not have nucleolar matrix and its lamina is not as typical as that of higher eukaryotes; Western blotting shows that lamina of Giardia and two other Archezoa Entamoeba invadens and Trichomonas vaginali all contain only one polypeptide each which reacts with a mammalia anti-lamin polyclonal serum and is similar to lamin B (67 ku) of mammlia in molecular weight. According to the results and references, it is suggested that nuclear matrix is an early acquisition of the eukaryotic nucleus, and it and the "eukaryotic chromatin" as a whole must have originated very early in the process of evolution of eukaryotic cell, and their origin should be an important prerequisite of the origin of eukaryotic nucleus; in the iamin (gene) family, B-type lamins (gene) should be the ancestral type and that A-type lamins (gene) might derive therefrom.

Phylogenetic positions of several amitochondriate protozoa - Evidence from phylogenetic analysis of DNA topoisomerase II

Several groups of parasitic protozoa, as represented by Giardia, Trichomonas, Entamoeba and Microsporida, were once widely considered to be the most primitive extant eukaryotic group - Archezoa. The main evidence for this is their 'lacking mitochondria' and possessing some other primitive features between prokaryotes and eukaryotes, and being basal to all eukaryotes with mitochondria in phylogenies inferred from many molecules. Some authors even proposed that these organisms diverged before the endosymbiotic origin of mitochondria within eukaryotes. This view was once considered to be very significant to the study of origin and evolution of eukaryotic cells (eukaryotes). However, in recent years this has been challenged by accumulating evidence from new studies. Here the sequences of DNA topoisomerase 11 in G lamblia, T vaginalis and E histolytica were identified first by PCR and sequencing, then combining with the sequence data of the microsporidia Encephalitozoon cunicul and other eukaryotic groups of different evolutionary positions from GenBank, phylogenetic trees were constructed by various methods to investigate the evolutionary positions of these amitochondriate protozoa. Our results showed that since the characteristics of DNA topoisomerase 11 make it avoid the defect of 'long-branch attraction' appearing in the previous phylogenetic analyses, our trees can not only reflect effectively the relationship of different major eukaryotic groups, which is widely accepted, but also reveal phylogenetic positions for these amitochondriate protozoa, which is different from the previous phylogenetic trees. They are not the earliest-branching eukaryotes, but diverged after some mitochondriate organisms such as kinetoplastids and mycetozoan; they are not a united group but occupy different phylogenetic positions. Combining with the recent cytological findings of mitochondria-like organelles in them, we think that though some of them (e.g. diplomonads, as represented by Giardia) may occupy a very low evolutionary position, generally these organisms are not as extremely primitive as was thought before; they should be polyphyletic groups diverging after the endosymbiotic origin of mitochondrion to adapt themselves to anaerobic parasitic life.

Characterisation of physiological conditions and evaluation of well-being in two species of bivalve molluscs (Ruditapes philippinarum and Chamelea gallina) intensively exploited in coastal and lagoon areas of the Northern Adriatic Sea (Italy)

Tese de Doutoramento, Ecologia, Especialidade de Ecofisiologia, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2007

Detecção do vírus do papiloma humano por PCR em tempo real : relevância para medicina legal

Tese de mestrado, Medicina Legal e Ciências Forenses, Faculdade de Medicina, Universidade de Lisboa, 2014

Development of user-friendly, high throughput screening for ligands and inhibitors of carbohydrate modifying enzymes

This paper describes the impact of cloud computing and the use of GPUs on the performance of Autodock and Gromacs respectively. Cloud computing was applicable to reducing the ‘‘tail’’ seen in running Autodock on desktop grids and the GPU version of Gromacs showed significant improvement over the CPU version. A large (200,000 compounds) library of small molecules, seven sialic acid analogues of the putative substrate and 8000 sugar molecules were converted into pdbqt format and used to interrogate the Trichomonas vaginalis neuraminidase using Autodock Vina. Good binding energy was noted for some of the small molecules (~-9 kcal/mol), but the sugars bound with affinity of less than -7.6 kcal/mol. The screening of the sugar library resulted in a ‘‘top hit’’ with a-2,3-sialyllacto-N-fucopentaose III, a derivative of the sialyl Lewisx structure and a known substrate of the enzyme. Indeed in the top 100 hits 8 were related to this structure. A comparison of Autodock Vina and Autodock 4.2 was made for the high affinity small molecules and in some cases the results were superimposable whereas in others, the match was less good. The validation of this work will require extensive ‘‘wet lab’’ work to determine the utility of the workflow in the prediction of potential enzyme inhibitors.

Projeto Prevenir: uma pesquisa acerca das mudanças no perfil das infecções por DST/AIDS, com a perspectiva de detectar pontos vulneráveis da prevenção

Rio Grande do Norte is among the Brazilian States where the tourism and sexual violence increasingly grow in the country, occupying 4th place in 2004. Associated to this fact, it comes the problematic one of the contamination of the women by Sexually Transmitted Disease (STD). Studies in Brazil have presented a considerable increase of the STDs, caused through lack of suitable protection in the sexual relationships. Due to the biological and psychosocial vulnerability, besides failures or inconsistencies in the condom use associated to the raised taxes of sexual activity with different partners, the STDs constitute the main risk of health. Many difficulties are found by the confrontation of this problem. In this context, this project had as aim to evaluate the vulnerability of this population of sexually active women in Natal-RN Ponta Negra neighbourhood to the infections by STDs, such as, Candida sp., Vaginoses Bacterial, Trichomonas Vaginalis and Chlamydia sp., arisen with the explosion of the sex market, showing a current statistical panorama. It was possible to detect vulnerable points in prevention through patient anamnesis, where the study it showed: high number of partners (8,3% with more than five), low age of first relationship and not the use of condoms (31,8% sometimes use and 45,8% had not used in the first relationship). Already consolidated by the preventive cytopathologic examination, these data were strengthened by high incidence of causing agents of STDs (58,6%). In this way, it is clear that the sexuality must to be thought on the context of the deep economic and socio-cultural transformations in which pass societies, and mainly the ones concerning to the sexuality exercise and to the sex market. With the profile change of the infections, new demands are placed in relation to the risk factors. Therefore, it can be concluded that the prevention vulnerable points detected as more important had been the deficiency in self-perception and wareness of the risk existence among the studied women

Chlamydial infection in a high risk population: association with vaginal flora patterns

This study aimed to determine the frequency of Chlamydia trachomatis (CT) infection among high risk Brazilian women and evaluate its association with vaginal flora patterns.This was a cross-sectional study, performed in an outpatient clinic of Bauru State Hospital, So Paulo, Brazil. A total of 142 women were included from 2006 to 2008. Inclusion criteria was dyspareunia, pain during bimanual exam, presence of excessive cervical mucus, cervical ectopy or with three or more episodes of abnormal vaginal flora (AVF) in the previous year before enrollment. Endocervical CT testing was performed by PCR. Vaginal swabs were collected for microscopic assessment of the microbial flora pattern. Gram-stained smears were classified in normal, intermediate or bacterial vaginosis (BV), and recognition of Candida sp. morphotypes. Wet mount smears were used for detection of Trichomonas vaginalis and aerobic vaginitis (AV).Thirty-four of 142 women (23.9%) tested positive for CT. AVF was found in 50 (35.2%) cases. The most frequent type of AVF was BV (17.6%). CT was strongly associated with the presence of AV (n = 7, 4.9%, P = 0.018), but not BV (n = 25, 17.6%, P = 0.80) or intermediate flora (n = 18, 12.7%, P = 0.28).A high rate of chlamydial infection was found in this population. Chlamydia infection is associated with aerobic vaginitis.

Alteração de flora vaginal em gestantes de baixo risco, atendidas em serviço público de saúde: prevalência e associação à sintomatologia e achados do exame ginecológico

Objetivou-se identificar a prevalência das alterações de flora vaginal em gestantes de baixo risco, sua associação à sintomatologia referida e exame ginecológico. É estudo quantitativo, descritivo e transversal, desenvolvido no serviço público de atenção básica de Botucatu, SP, no período de 2006 a 2008, com 289 gestantes, amostradas de forma estratificada por unidade. Realizou-se exame do conteúdo vaginal, utilizando-se coloração pelo método de Gram e pesquisa de Trichomonas vaginalis em meio líquido de Diamond. Desconsiderando-se as associações, a prevalência de flora vaginal alterada foi de 49,5%, sendo as mais frequentes: vaginose bacteriana (20,7%), candidíase vaginal (11,8%) e flora intermediária (11,1%). Os dados apontam elevada prevalência das alterações de flora vaginal, com pouca associação à sintomatologia, mas associação com achados do exame ginecológico. Considerando-se as repercussões maternas e perinatais indesejáveis e a prática laboratorial exequível, sugere-se o estabelecimento de rotina para diagnóstico das alterações de flora vaginal em gestantes de baixo risco.

Correlation of Atopobium vaginae Amount With Bacterial Vaginosis Markers

Objective. The purpose of this study was to test the correlation of the amount of Atopobium vaginae with the most commonly used markers for bacterial vaginosis (BV).Materials and Methods. We enrolled 103 nonpregnant and premenopausal women that were positive for BV by Amsel criteria and with a Nugent score higher than 3. All women were negative for yeast, Chlamydia trachomatis, Trichomonas vaginalis, and Neisseria gonorrhoeae. A. vaginae concentration was determined by quantitative polymerase chain reaction from samples of vaginal rinsings with 2 mL of sterile saline.Results. There was no difference in the median values of A. vaginae concentration when comparing samples with presence or absence of each individual Amsel criterion. In the case of a higher pH cutoff value of 4.9, greater amounts of this microorganism (p = .02) were found. In addition, correlation tests showed that A. vaginae concentration is positively correlated with pH (p < .001) and with Nugent scores (p = .003).Conclusions. The quantification of A. vaginae is useful for identification of the most severe cases of BV.