Influence of Neuropeptide Y and Neuropeptide Y 2 Receptor Variants in Acute Coronary Syndrome

Abstract Background The neuropeptide Y (NPY) is one of the most abundant neurotransmitters in the nervous system. NPY acts as a potent stimulator of angiogenesis, inflammation, and adipogenesis, through the NPY 2 receptor (NPY2R). Changes in the NPY signaling pathway have been linked to Acute Coronary Syndrome (ACS). Objectives The purpose of this study is to determine the association between variants in the NPY and NPY2R genes, as well as the severity of acute coronary syndrome (ACS). Methods Approximately 221 ACS patients and 278 healthy controls were selected for this study. Four variants in NPY and two variants in NPY2R genes were genotyped using Taqman allelic discrimination and sequencing. The Chi-square and Fisher's exact tests were used to verify the genotype frequencies. The logistic regression analyses were used for the evaluation of the studied variables. Haplotype analysis was used to evaluate the linkage disequilibrium (LD) between the variants (p<0.05). Results An association of NPY c.20T>C variant was found with the ACS group when compared to the healthy group. In the analysis between variants and risk factors in the ACS group, NPY c.84G>A was associated with hypertension. The analysis between TIMI risk showed a significance for NPY c.20T>C between the low and intermediate/high TIMI risk groups. In the haplotype analysis, strong linkage disequilibrium (LD) was found between the variants NPY c.150G>A and NPY c.-485T>C. Conclusion The NPY c.20T>C variant appears to contribute to the development of ACS. The NPY2R c.-1116A>G variant may contribute to the early development of ACS and the NPY c.84G>A variant appears to contribute to the development of hypertension. In addition, the NPY c.20T>C is associated with a protective effect in ACS severity.

Preliminary results in the immunodiagnosis of tuberculosis in children based on T cell responses to ESAT-6 and PPD antigens

The aim of this work was to study the difference in interferon gamma (IFN-gamma) production by T lymphocytes after early secretory antigen target 6 (ESAT-6) or purified protein derivate (PPD) stimulation in whole blood culture supernatants from children with suspected tuberculosis (TB) disease (n = 21), latent TB infection (n = 16) and negative controls (NC) (n = 22) from an endemic area in Brazil. The concentration of IFN-gamma (pg/ml) was measured by enzyme linked immunosorbent assay and the differences in the IFN-gamma levels for each group were compared and evaluated using an unpaired Student's t-test; p values < 0.05 were considered significant. Measurement of IFN-gamma levels after ESAT-6 stimulation raised the possibility of early diagnosis in the latent TB group (p = 0.0030). Nevertheless, the same group showed similar responses to the NC group (p > 0.05) after PPD stimulation. The IFN-gamma assay using ESAT-6 as an antigenic stimulus has the potential to be used as a tool for the immunodiagnosis of early TB in children.

Treatment of human acute schistosomiasis with oxamniquine induces an increase in interferon-gamma response to Schistosoma mansoni antigens

Patients with acute schistosomiasis were studied before and after oxamniquine treatment. They had been exposed to cercariae 5 to 9 weeks before, and presented compatible clinical manifestations, eosinophilia, and high levels of total IgE. Interferon-gamma (IFN-gamma) and interleukin-4 were measured by ELISA in whole blood samples under soluble egg antigen or soluble adult worm preparation stimulation. After treatment, the reduction of leukocytosis and eosinophilia were not significant, but total IgE levels decreased significantly, in contrast to IFN-gamma levels that were significantly increased. The oxamniquine treatment of acute schistosomiasis patients is followed by an improvement of a Th1 response in vitro. If this response has a protective aspect is unknown, and some investigations need to be realized.

Preliminary results on interleukin-4 and interleukin-10 cytokine production in malnourished, inducible nitric oxide synthase-deficient mice with schistosomiasis mansoni infection

Schistosoma mansoni infected C57Bl/6 inducible nitric oxide synthase (iNOS)-deficient and non-deficient malnourished mice, both fed a balanced controlled diet were studied. Interleukins, IL-4 and IL-10 responses to soluble egg antigens (SEA) 90 days after infection, were determined. Our results suggest that in iNOS deficient, malnourished mice, 90 days after of infection, nitric oxide has a downregulating effect on IL-4 and IL-10 production. We are currently investigating the biological significance of these findings.

Preliminar evaluation of cytokines in the hepatitis C-schistosomiasis co-infection

Evaluation of hepatic fibrosis is usually performed by histopathological examination of biopsies. However, this is an invasive and potentially dangerous procedure. Several studies have proposed serum biological markers of hepatic fibrosis. This communication evaluates the use of serum cytokines as markers of hepatic fibrosis in hepatitis C, schistosomiasis, and co-infection.

Evaluation of tests based on the antibody response to keyhole limpet haemocyanin and soluble egg antigen to differentiate acute and chronic human schistosomiasis mansoni

Specific IgG and IgM responses to soluble egg antigen (SEA) and keyhole limpet haemocyanin (KLH) were measured by ELISA in patients with acute and chronic schistosomiasis. The tests based upon IgM and IgG antibodies responses to KLH presented the best diagnostic discrimination, and can be used in conjunction with clinical and epidemiological data to the differential diagnosis of acute schistosomiasis.

Studies on the production and regulation of interleukin, IL-13, IL-4 and interferon-gamma in human Schistosomiasis mansoni

The production and regulation of interleukin (IL) IL-13, IL-4 and interferon-gamma was evaluated in different clinical forms of human schistosomiasis. The mechanisms of immune regulation are apparently different in the various clinical stages of the disease, some of them being antigen specific

Partial molecular characterization of Sm8, a tegumental antigen of Schistosoma mansoni

Sm8 is a major tegumental antigen of Schistosoma mansoni. The partial cDNA was isolated and analyzed. Sequence analysis revealed transmembrane compatible hydrophobic domains and a putative leucine zipper pattern. The mRNA and the protein are predominantly expressed in adult worms

Preliminary results on the effects of CD40/CD40L interactions and SAC-induction on IFN-gamma expression in human schistosomiasis

In this communication the authors analyzed the pattern of expression of IFN-gamma as a surrogate type 1 response in different clinical forms of schistosomiasis in response to stimulation involving T-cell dependent and T-cell independent pathways, to investigate which pathways were functional in human schistosomiasis, and to further characterize the nature of Th1 response impairment in this parasitic disease

Expression of recombinant antigens in Escherichia coli: application on immunochemical studies of Schistosoma mansoni tegumental antigens

Sm15 and Sm13 are recognized by antibodies from mice protectely vaccinated with tegumental membranes, suggesting a potencial role in protective immunity. In order to raise antibodies for immunochemical investigations, the genes for these antigens were expressed in pGEX and pMAL vectors so that comparisons could be made among different expression systems and different genes. The fusion proteins corresponding to several parts of the gene for the precursor of Sm15 failed in producing antibodies recognizing the parasite counterpart. On the other hand, antibodies raised against Sm13 MBP-fusion proteins recognized the 13 kDa tegumental protein. Thus the peculiarities of the gene of interest are important and the choice of the expression system must sometimes be decided on an impirical basis.

Factors involved in Schistosoma mansoni infection in rural areas of northeast Brazil

Two contiguous villages in Tracunhaem country (State of Pernambuco) endemic for schistosomiasis, were studied: Itapinassu (138 inhabitants) and Sao Joaquim (91 inhabitants). Agriculture predominates in the former region while ceramics is the main activitiy in the latter. Although no statistical difference was found regarding prevalence, severe infection (<400 epg) predominated in Itapinassu, probably related to the kind of occupation. No association was found between parasite burden and severity of disease, in spite of the high infection rates for Schistosoma mansoni in both communities (aprox. 60 per cent). Typical epidemiological features of schistosomiasis such as age-realted prevalences and intensities of infection (high in children, low in adults) were also mutual characteristics. Nutritional status determined through anthropometric evaluation was carried out by measuring specific anthropometric indicators. A deficit of energy intake, as well as vitamin A and riboflavin deficiencies were detected. The prevalence of moderate or severe undernutrition in patients under 18 years old was 21.9 per cent in Itapinassu and 24.1 per cent in Sao Joaquim. In this group as association was found between prevalence of schistosomiasis and chronic undernutrition. Similarly, for patients over 18 years old the prevalence of undernutrition was higher than 20 per cent. However, in this case no association between nutritional status and either prevalence of schistosomiasis or parasite burden could be detected. The two communities had not been treated for eight years.

Effects of non-specific immunopotentiators in experimental Schistosoma mansoni infection: II. Corynebacterium parvum

Neste trabalho foram avaliados os efeitos do Corynebacterium parvum na protecao do hospedeiro, reacao tecidual e quimiotaxia "in vivo" em camundongos infectados pelo S. mansoni. O C. parvum foi dado intraperitonealmente usando uma dose de 0,7 mg, duas vezes por semana (durante 04 semanas), 30 dias antes (tratamento profilatico) e 30 dias apos a infeccao (tratamento curativo). A protecao do hospedeiro foi avaliada atraves da contagem de vermes adultos obtidos atraves da perfusao hepatica de camundongos infectados e esse numero foi bem menor no grupo profilatico comparado ao grupo controle (p=0,018), obtendo-se 44 por cento de protecao. A resposta quimiotatica "in vivo", nos grupos curativo e profilatico, foi maior do que no grupo infectado/nao tratado (p=0,009 e p=0,003, respectivamente). As reacoes teciduais foram descritas em todos os grupos, embora nao tenham ocorrido diferencas marcantes entre eles. As possiveis implicacoes biologicas e a relevancia dos achados para a resposta defensiva do hospedeiro e controle da esquistossomose sao discutidas neste trabalho

Standardization of the dot enzyme-lynked immunosorbent assay (dot-ELISA) for experimental plague

A dot enzyme linked immunosorbent assay (dot-ELISA) was previously developed to detect specific antibodies in rabbits sera immunized against FIA protein obtained from Yersina pestis. This antigen was covalently linked onto the surface of dacron (polyethyleneterephthalate). Here, standard conditions are described for the optimization of this procedure: an amount of 20 ng of FIA protein was fixed onto dacron; anti-rabbit IgG peroxidase conjugate diluted 1:8,000 and 30% non-fat instant milk as blocking substance were used throughout the method. This procedure was compared with that employing nitrocellulose as solid-phase which showed to be more sensitive. However, the method based on dacron did not show false positive reactions against non-immunized rabbits sera at low antigen amount and diluted anti-IgG peroxidase conjugate

The use of dacron plates for DOT enzyme-linked immunosorbent assay (DOT-ELISA)

Dacron (polyethylenetherephthalate) is proposed as a matrix for dot-ELISA procedures, as an alternative to nitrocellulose. Plates of dacron were partially hydrazinolyzed and hydrazide groups introduced were converted to azide groups. The derivative dacron-antigen was covalently linked on to the plates through these azide groups. The derivative dacron-antigen was exaustively washed according to CROOK and antigen was still fixed onto the plates. Protein F1A purified from Yersinia pestis was used as a model. Triration of sera from immunized and non immunized rabbits against this protein was carried out by employing the dot-ELISA method. No significant difference was observed using dacron-antigen and nitrocellulose-antigen preparations. Howwvwe, both procedures showed to have a significant better performance in comparasion with the passive hemagglutination method. The specificity and reproductibility of the dot-ELISA assay using both preparations showed a similar behaviour. Nitrocellulose preparation was stable at 4 graus Centígrados, 28 graus centígrados and -20 graus centígrados for 90 days, whereas the dacron-antigen derivative was stable only when stored at 4 graus centígrados. Dacron-antigen derivative could be re-used when the spot developing was proceeded using 4-chloro-1-naphtol as substrate

Effects of betamethasone on the course of experimental infection with Trypanosoma cruzi

Foram estudados os efeitos da betametasona administrada na fase pós-aguda imediata de uma infecçäo pelo T. cruzi em camundongos. O tratamento consistiu de 30 doses diárias de 0,15 mg de betametasona, a partir de 42§ dia de infecçäo, näo havendo aparecimento de novos surtos de parasitemia. No tempo de duraçäo do experimento (7 meses) näo houve diferença entre as lesöes histopatológicas dos animais tratados e dos näo tratados. O grupo experimental apresentou uma maior mortalidade acumulada no 75§ dia de infecçäo, o que pode ser atribuído a infecçöes bacterianas associadas. Por outro lado, camundongos albinos "outbred", infectados com baixo inóculo, näo se apresentaram como bom modelo de doença de Chagas, já que näo desenvolveram lesöes importantes nem na fase aguda nem após 7 meses de infecçäo. Em conclusäo, o tratamento imunosupressivo prolongado, após a fase aguda de uma infecçäo mínima com a cepa Y do T. cruzi näo tem influência sobre o curso da infecçäo, pelo menos no que tange ao agravamento da mesma

Modificaçäo da técnica da bolsa de ar para mensuraçäo da quimiotaxia in vivo / Modification of the air pouch technique for evaluation of chemotaxis in vivo

Propöem algumas modificaçöes a um método de mensuraçäo da resposta quimiotáxica in vivo, que se baseava na observaçäo da resposta leucocitária à introduçäo de quimiotáxicos, em uma bolsa de ar produzida no tecido conjuntivo de camundongos. As modificaçöes introduzidas foram a utilizaçäo de anestesia leve, facilitando a produçäo da bolsa e a imobilizaçäo dos animais em posiçäo vertical, permitindo a localizaçäo da área exposta à atividade quimiotáxica e tornando a técnica mais simples. As citadas modificaçöes tornaram o método mais reprodutível e eficiente, permitindo o emprego de amostras menores no ensaio