7 research outputs found
PATHOLOGICAL STUDY ON STAPHYLOCOCCUS XYLOSUS ISOLATED FROM PATIENTS WITH URINARY TRACT INFECTIONS
No full textRole of peptidoglycan in the pathogenesis of Staphylococcus saprophyticus in mice
No full textThe pathogenicity of S. saprophyticus was studied in mice. A group of white mice were injected transurethrally using a catheter with S. saprophyticus S67 cell suspension in a concentration reached 109 CFU/ml. concomitantly, the role of its peptidoglycan in the pathogenicity was studied by injecting another group of mice with 0.3 mg/0.2 ml of partially purified S. saprophyticus S67 peptidoglycan extract. After autopsy, kidneys and urinary bladder showed several histopathological changes both in cells and peptidoglycan injected mice, included: hydropic degeneration, glomerulus shrinkage, congestion of renal vessels, infiltration of inflammatory cells, and dekeratinization in urinary bladder
THE PATHOLOGICAL EFFECT OF PEPTIDOGLYCAN ON RATS’ LUNGS PART TWO: NON PATHOGENIC BACTERIA BACILLUS SUBTILIS
No full textSemantic metrics
No full textIn the context of the Semantic Web, many ontology-related operations, e.g. ontology ranking, segmentation, alignment, articulation, reuse, evaluation, can be boiled down to one fundamental operation: computing the similarity and?or dissimilarity among ontological entities, and in some cases among ontologies themselves. In this paper, we review standard metrics for computing distance measures and we propose a series of semantic metrics. We give a formal account of semantic metrics drawn from a variety of research disciplines, and enrich them with semantics based on standard Description Logic constructs. We argue that concept-based metrics can be aggregated to produce numeric distances at ontology-level and we speculate on the usability of our ideas through potential areas
Leishmania infantum and dog : immunological and epidemiological studies about infection and disease
No full textL'objectiu d'aquesta tesi va ser obtenir nous coneixements sobre la immunologia i epidemiologia de la infecció per Leishmania en gossos que viuen en zones endèmiques. El capítol 2 descriu l'expressió d'anticossos anti-Leishmania IgG, IgG1 i IgG2 en una població de gossos. Els nivells d'immunoglobulines en gossos asimptomàtics van ser molt variables i menors que els dels animals malalts. En els animals malalts, els nivells de IgG i IgG2 van ser molt alts però els nivells d' IgG1 molt variables. Els resultats van mostrar la gran variació en l'expressió de IgG1 tant en gossos asimptomàtics com en simptomàtics, així com la baixa correlació de la IgG1 amb la IgG o IgG2. El capítol 3 descriu l'avaluació i comparació de l'eficàcia de dues preparacions de leishmanines en la detecció de la resposta cel·lular davant de Leishmania en el gos. El capítol 4 mostra l'estudi de la resposta humoral i cel·lular en una població de gossos. El 77% dels gossos va mostrar una resposta immunitària específica davant de Leishmania, ja fos humoral o cel·lular. El 80% dels cans eivissencs i el 48% dels gossos d'altres races van presentar resposta cel·lular. Els resultats van mostrar que la taxa d'infecció era molt alta, i que els gossos presentaven un ampli ventall de respostes inmunitàries, des de gossos resistents fins a gossos malalts. El ca eivissenc va manifestar més uniformement resposta cel·lular. El capítol 5 descriu l'estudi de la prevalença de la malaltia, la seroprevalença i la prevalença de la infecció. Es va analitzar el quadre clínic, la serologia i la presència d'ADN de Leishmania en diferents teixits. La prevalença de la malaltia i seroprevalença van ser, respectivament, d'un 13% i d'un 26%. Els resultats de PCR positives en moll d'ós, conjuntiva i pell van ser respectivament, d'un 18%, 32% i 51%. La prevalença de la infecció va ser d'un 67%. La majoria de gossos de zona endèmica ha estat infectat pel paràsit. El capítol 6 descriu l'estudi de paràmetres immunològics (serologia, test intradèrmic amb leishmanina, assaig de proliferació de limfòcits i detecció d'IFN-g i TNF-a) en l'avaluació de gossos infectats amb Leishmania. La majoria dels animals infectats sense simptomatologia clínica presentava nivells variables d'anticossos, reacció positiva al test intradèrmic, bona resposta proliferativa al antigen de Leishmania i producció d'IFN-g. La resta va mostrar nivells variables d'anticossos però absència de reacció al test intradèrmic. Abans del tractament, els animals malalts presentaven alts nivells d'anticossos, test intradèrmic negatiu, no producció d'IFN-g i producció de TNF-a. La millora clínica es va associar amb la disminució dels anticossos i amb l'augment del diàmetre del test intradèrmic. La combinació de la serologia, el test intradèrmic i la medició de citocines constitueixen tècniques útils i d'alta rellevància clínica en l'avaluació de la resposta inmunitària d'un pacient individual.The objective of this thesis was to obtain new knowledge about the immunology and epidemiology of Leishmania infection in dogs living in endemic regions in the Mediterranean basin. Chapter 2 describes the expression of IgG, IgG1 and IgG2 specific antibodies to L. infantum in a wide population of dogs. The levels of immunoglobulins in asymptomatic dogs were highly variable and lower than those found in ill dogs. In ill dogs, the levels of IgG and IgG2 were very high but the levels of IgG1 were extremely variable. Overall results showed a large variation in the IgG1 expression in asymptomatic and symptomatic dogs and a low IgG1 correlation with IgG or IgG2. Chapter 3 describes the evaluation and comparison of the efficacy of two leishmanins for detection dog Leishmania cellular immune response. Chapter 4 describes the study of humoral and cellular responses in a population of dogs. Seventy-seven percent of the dogs demonstrated a specific Leishmania response either humoral or cellular. Eighty percent of ibizian hounds and 48% of dogs of other breeds presented a cellular response. The results showed that the rate of infection was high and that dogs presented a broad range of immune responses from resistant to ill dogs. The Ibizian hound manifested a more uniform cellular response. Chapter 5 describes the study of the prevalence of Leishmania infection, the seroprevalence and the prevalence of canine leishmaniosis. Clinical exploration for the presence of clinical signs compatible with leishmaniosis, the titre of anti-Leishmania antibodies, and the presence of Leishmania DNA by PCR on several tissues were assessed. The prevalence of the disease was 13% and the seroprevalence was 26%. The results of positive PCR in the bone marrow, the conjunctiva and the skin were 18%, 32% and 51%, respectively. The prevalence of the infection was 67%. The results showed that Leishmania infects the majority of dogs living in an endemic area. Chapter 6 describes the study of immunological parameters (anti-Leishmania IgG1, IgG2, total IgG antibodies, LST, LPA, and production of IFN-g and TNF-a) in the evaluation of dogs infected by Leishmania. The majority of infected animals without clinically patent disease showed variable titres of anti-Leishmania antibodies, a positive LST, a strong Leishmania antigenic proliferative response, and a high production of IFN-g. The remainder showed positive titres of anti-Leishmania antibodies with a negative positive LST. Before treatment, ill dogs presented high levels of anti-Leishmania antibodies, negative LST, no production of IFN-g but a production of TNF-a. Clinical recovery was associated with a decrease in the titre of antibodies and an increase of the diameter of the LST. The combination of serology, LST, and measurement of cytokines constitutes a useful, clinically relevant method to evaluate the immune response to Leishmania in a single patient
Clinical aspects of embryo implantation: from the perspective of tissue perfusion.
No full textHypothesis: Pelvic perfusion is the pivotal factor for the outcome of in vitro fertilisation (IVF) treatment once clinical and embryological variables are controlled for their effect.;Demonstration of Hypothesis: In a series of three studies, the clinical aspects of embryo implantation were examined from the perspective of tissue perfusion.;Epidemiological Study: Clinical and embryological data were evaluated to predict multiplicity of implantation and ongoing pregnancy in IVF treatment. Oocyte and embryo quality were appraised and the impact of the number of embryos transferred was assessed.;Study on In-vivo Vascular Physiology: The prognostic role of utero-ovarian perfusion and its pharmacological manipulation with low dose aspirin was evaluated in the outcome of IVF treatment. Serum, follicular fluid vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR) concentrations were correlated with Doppler indices.;Study on In-vivo Endometrial Physiology: Endometrial receptivity (in terms of endometrial thickness and echo-pattern) and VEGF-VEGFR concentrations were evaluated with regards to the outcome of frozen-thawed embryo replacement (FTER) during natural and hormone replacement cycles.;Results: The epidemiological study showed that the outcome of IVF treatment was closely associated with the severity of subfertility. Ovarian reserve and response to stimulation were the key factors. The probability of pregnancy was affected by the number and quality of oocytes and by their fertilisation rate and the cleavage rate of the resulting embryos. The potential to provide mature oocytes and high quality embryos was an inherent characteristic of the ovaries and independent of stimulation protocols. When embryo quality was taken into consideration, the number of embryos transferred no longer affected the chance of pregnancy. The clinical study showed that the chance of pregnancy was directly dependant upon tissue perfusion. Pregnancy rates were very low with uterine artery pulsatility index >3 (PI) and peri-follicular PI >1. Better ovarian reserve, response to stimulation, endometrial development, implantation and pregnancy rates were associated with low follicular fluid VEGF-VEGFR levels and this was also associated with good uterine and endometrial perfusion. Aspirin (150 mg/day) had no beneficial effect on Doppler indices, ovarian response to stimulation, implantation or pregnancy rates. Pregnancy rates were similar with naturally and hormonally prepared endometrium in frozen-thawed embryo replacement cycles. Higher serum VEGF and lower VEGFR levels were observed in pregnant cycles, but the differences were not significant. Endometrial echo-pattern and thickness did not affect conception.;Conclusions: Tissue perfusion plays a key role in the physiological steps leading to conception and implantation. Aspirin (150 mg/day) improved neither tissue perfusion nor the outcome of fresh embryo transfer. The type of endometrial preparation did not affect the outcome of frozen-thawed embryo replacement cycles
The effects of host-vector relationships and density dependence on the epidemiology of visceral leishmaniasis
No full textIn Latin America, visceral leishmaniasis (VL) is caused by infection with
Leishmania infantum, an endemic but lethal parasite transmitted by Lutzomyia
longipalpis sandflies. Multiple hosts are implicated in VL transmission; therefore
sandfly biting preferences may be pivotal in determining transmission dynamics.
Host preferences are poorly understood with simple preference-host density
relationships being conventionally assumed.
Combined modelling and fieldwork approaches were used to investigate the
preference of sandflies for key host types (dogs, humans and chickens) and force of
infection (FOI) over a range of vector and host densities. In Brazil, variable vector
densities were (i) observed over a period of seasonal variation, and (ii)
experimentally manipulated via “trapping out” (sustained CDCLT capture to reduce
local vector density). Host density was also manipulated by (iii) the incremental
introduction of chickens to experimental sheds.
Results suggest that there is a significant link between alternative host density and
the absolute and relative preference of sandflies for humans and dogs. Investigations
also indicate that host choice has a vector density dependent element, which varies
significantly and nonlinearly depending upon vector density. Meta-analysis and
mathematical modelling of human and canine prevalences across Brazil also point
toward variable transmission rates to these hosts attributable to density-dependent
biting preferences observed in the field. These host choice dynamics ultimately
combine to demonstrate the influence of host and vector densities on FOI on dogs
and humans, but there are significant interactions between host and vector densities
resulting in complex FOI relationships.
Nonlinearities are likely explained by density dependent sandfly aggregation
behaviour upon outdoor living hosts, such as chickens, as vector density rises. This
preference behaviour may have far reaching implications for our understanding of
transmission and control, and potentially indicate host density manipulation as an
intervention measure
