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Biomedical subjects

S Gomes

Publications and source records attributed to S Gomes.

13 recordsLinked to original sources
PubMed2005

Effect of the peroxisome proliferator-activated receptor-gamma C161T polymorphism on lipid profile in Brazilian patients with Type 2 diabetes mellitus.

AIM: The aim of the present study was to examine the effects of the C161T polymorphism of the peroxisome proliferator-activated receptor gamma (PPARgamma) gene in Brazilian subjects with Type 2 diabetes mellitus (T2DM) and controls residing in Sao Paulo City, Brazil. METHODS: Genomic DNA was obtained from 207 patients with T2DM and 170 unrelated normoglycemic individuals (CG). Anthropometric data included: body mass index, waist, hip, waist-to-hip ratio; biochemical parameters: fasting plasma glucose, total cholesterol, HDL- and LDL-cholesterol, triglycerides, glycated hemoglobin and insulin. Systolic and diastolic blood pressure was also measured. Screening for mutations in the entire coding region of the PPARgamma gene was carried out by PCR, single strand conformational polymorphism analysis (SSCP) and sequencing. C161T polymorphism was analyzed by PCR-RFLP. RESULTS: The C161T polymorphism was the only variant found in exon 6 of the PPARgamma gene. The frequency of the 161T allele in T2DM (0.10) was similar to that found in CG (0.07, p=0.210). Serum triglycerides (p=0.040), VLDL-cholesterol (p=0.040) and Atherogenic Index of Plasma (AIP; p=0.003) were significantly lower in 161T allele carriers than non-carriers in women of the T2DM group. CONCLUSIONS: Our results show that the C161T polymorphism in the PPARgamma gene is not associated with variables related to T2DM or insulin resistance in the Brazilian population. However, a reduction of serum triglycerides and AIP was observed in women with 161T allele of the C161T polymorphism of the PPARgamma gene.

Adult↗
PubMed2005

Side effects in sea bass (Dicentrarchus labrax L.) due to intraperitoneal vaccination against vibriosis and pasteurellosis.

Sea bass (Dicentrarchus labrax L.) were injected intraperitoneally with monovalent (Photobacterium damselae subsp. piscicida or Vibrio anguillarum) and divalent (Ph. damselae subsp. piscicida and V. anguillarum) vaccine formulations, with or without adjuvants (mineral oil, liposome or alginate), to evaluate the short and long-term pathological effects. Eight animals from each group were sampled one, two, four and 11 months after intraperitoneal injection. The acute peritoneal response and the progression to a chronic status were evaluated by analysing peritoneal leucocytes collected during the first days post-injection. To evaluate the chronic response, the late peritoneal leucocyte response was analysed and the peritoneal cavity was examined and the intra-abdominal lesion level scored based on a pre-defined scale. Correlation between leucocyte exudative response, tissue inflammatory response and the development of granuloma were sought. The acute leucocyte response was characterized by an early (24-48 h) mobilization of neutrophils and macrophages, with phagocyte numbers dependent on the formulation, but no significant variations were observed in lymphocytes/small cells and EGCs. Later on, a steady increase occurred in lymphocytes/small cells and EGCs and a high concentration in neutrophils and macrophages was maintained up to 30-60 days in groups i.p. injected with oil adjuvanted formulations with antigen. All the lesions observed were moderate, indicating that in sea bass, the pathological effects due to intraperitoneally injected vaccines are less severe than in other fish species. The divalent oil adjuvanted vaccine induced the most severe side effects, with macroscopic granulomas consistently present up to 11 months.

Adjuvants, Immunologic↗
PubMed1998

The immunology of canine leishmaniosis: strong evidence for a developing disease spectrum from asymptomatic dogs.

Asymptomatic mixed breed dogs (49) from a region of high incidence of visceral leishmaniosis in Portugal were examined for the presence of Leishmania-specific cellular immunity using a proliferation assay and humoral immunity using an indirect antibody fluorescent test (IFAT) and an ELISA. The results were compared directly with 25 mixed breed dogs permanently residing in a non-endemic region (Scotland). Unlike similar studies in humans from non-endemic areas, there was no evidence of any immunological response against leishmanial antigen whatsoever from the latter group of animals. Of the 49 dogs from Portugal, however, 20 had demonstrable parasite-specific cellular immunity. Depending on the assay and criteria used to measure a positive humoral response, 11, 16 or 24 dogs had a Leishmania-specific humoral response with the ELISA being the most sensitive assay system. While 16, 12 or 8 of the dogs had clearly only a cellular response (depending on which criterion was used to constitute a true antibody response) and 7, 8 or 12 had only humoral response, other 4, 8 or 12 of the dogs had both cellular and humoral responses. This study clearly demonstrates that the infection rate of canine leishmaniosis is not only higher than previously thought using serological tests alone but that the response to infection is already highly polarised in many asymptomatic dogs. It is postulated that an individual dog's position within the immunological spectrum is likely to indicate how the disease will progress.

Animals↗
PubMed1995

Susceptibility of beige mice to Mycobacterium avium: role of neutrophils.

The beige mutation in C57BL/6 mice has been shown to increase the susceptibility to infection by Mycobacterium avium. In this study, we confirmed those results and showed that the effect of the beige mutation was most obvious after infection with a strain of lower virulence than with a highly virulent isolate of M. avium. The dissemination of M. avium from the gut was observed with both C57BL/6 and beige mice but was faster in the latter. The expression of gamma interferon (IFN-gamma) and the priming for tumor necrosis factor production during an in vivo infection were similar between beige and immunocompetent C57BL/6 mice. IFN-gamma produced during the infection of beige mice was protective in the spleen, and the administration of recombinant IFN-gamma restored the resistance in the spleen to levels similar to those found in control mice. There were no histological differences between wild-type and beige mice with respect to granuloma formation in the liver. The increased susceptibility of beige mice to M. avium as manifested in the liver was reduced by transfusing neutrophils from wild-type C57BL/6 mice. Likewise, depletion of neutrophils from C57BL/6 mice rendered them as susceptible to M. avium infection of the liver as beige mice. Our results point to the participation of neutrophils in the defect of beige mice in addition to other defects. Furthermore, these results show that neutrophils play a significant role in the defense mechanisms against mycobacterial infections and that beige animals may be a useful model for study of the role of neutrophils in mycobacteriosis.

Animals↗
PubMed1987

Separation of temporal control and trans-acting modulation of flagellin and chemotaxis genes in Caulobacter.

The genes involved in the biogenesis of the flagellum and the chemotaxis machinery are temporally regulated during the Caulobacter crescentus cell cycle. Using plasmid complementation, we have mapped the extent of the flaY and flaE genes. These genes function in trans to regulate the expression of the flagellin genes and the chemotaxis genes. We have found that the trans regulation that modulates the amount of the flagellins and the chemotaxis proteins can be separated from the temporal control of fla and che gene expression. This conclusion is based on two observations: the low level of synthesis of flagellins and chemotaxis proteins in flaY and flaE mutant strains occurred at the correct time in the cell cycle, and complementation with plasmids containing intact flaY and flaE genes resulted in the synthesis of normal levels of flagellins and chemotaxis gene products with the maintenance of temporal cell cycle control.

Bacteria↗
PubMedDate not supplied

Metalloproteases in Trypanosoma rangeli-infected Rhodnius prolixus.

Protease activities in the haemolymph and fat body in a bloodsucking insect, Rhodnius prolixus, infected with Trypanosoma rangeli, were investigated. After SDS-polyacrylamide gel electrophoresis containing gelatin as substrate, analysis of zymograms performed on samples of different tissues of controls and insects inoculated or orally infected with short or long epimastigotes of T. rangeli, demonstrated distinct patterns of protease activities: (i) proteases were detected in the haemolymph of insects which were fed on, or inoculated with, short epimastigotes of T. rangeli (39 kDa and 33 kDa, respectively), but they were not observed in the fat body taken from these insects; (ii) protease was also presented in the fat bodies derived from naive insects or controls inoculated with sterile phosphate-saline buffer (49 kDa), but it was not detected in the haemolymph of these insects; (iii) no protease activity was observed in both haemolymph and fat bodies taken from insects inoculated with, or fed on, long epimastigotes of T. rangeli. Furthermore, in short epimastigotes of T. rangeli extracts, three bands of the protease activities with apparent molecular weights of 297, 198 and 95 kDa were detected while long epimastigotes preparation presented only two bands of protease activities with molecular weights of 297 and 198 kDa. The proteases from the insect infected with T. rangeli and controls belong to the class of either metalloproteases or metal-activated enzymes since they are inhibited by 1,10-phenanthroline. The significance of these proteases in the insects infected with short epimastigotes of T. rangeli is discussed in relation to the success of the establishment of infection of these parasites in its vector, R. prolixus.

Adipose Tissue↗
PubMedDate not supplied

Demonstration of natural Leishmania infection in asymptomatic dogs in the absence of specific humoral immunity.

Asymptomatic dogs from a Kala-Azar endemic region were screened for infection status by parasitological, immunological and molecular techniques. Bone marrow was examined for the presence of parasites by NNN culture and by using the Lmet 2 DNA probe. All the samples were negative in culture but 24 of 41 were positive as determined by the probe. Cellular and humoral immunity were detected by T cell proliferation assays and IFAT respectively. Specific cellular and humoral immunity were found in 20 and 26 dogs respectively out of a total of 41 dogs examined. The vast majority of dogs with Leishmania-specific antibodies were found to be parasitologically positive using the DNA probe while almost half those that had demonstrable cellular immunity were apparently parasite free. The observation that dogs can develop cellular immunity following natural infection clearly indicates that there is a spectrum of canine leishmaniasis similar to that observed in the human disease. The prevalence of dog leishmanial infection must also be higher than was presumed.

Animals↗