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S González

Publications and source records attributed to S González.

At least 37 records · Page 2Linked to original sources
PubMed2003

Diet score is associated with plasma homocysteine in a healthy institutionalised elderly population.

BACKGROUND AND AIM: Total plasma homocysteine (tHcy) is an independent risk factor for cardiovascular diseases. Among other dietary and non-dietary factors, B vitamins, such as folate, riboflavin and cobalamin, are primary determinants of tHcy in the general population. However, research has concentrated on the relationship of these nutrients with tHcy, and little is known about overall eating patterns and tHcy. METHODS AND RESULTS: In this study, we analysed whether a diet score based on the consumption of folate-, riboflavin- and cobalamin-rich food groups was associated with tHcy in a sample of 140 institutionalised elderly subjects (59 men and 81 women aged 60-80 years) from Northern Spain. The food groups identified as the major contributors to the intake of the three vitamins were vegetables, fruit, fish, meat and milk and dairy products. The mean tHcy level was 13.3+/-5.1 micromol/L (range: 3.9-30.7 micromol/L). None of the food groups predicted tHcy levels individually, but the overall diet score was inversely associated with tHcy in a multiple linear regression analysis. High tHcy levels (>16 micromol/L) were almost twice as prevalent in the groups scoring less than 7 than in those scoring 7 or more (37.5 vs 19.6%, p=0.021). CONCLUSIONS: These data suggest that a dietary pattern characterised by high intakes of B vitamin-rich foods is associated with a lower tHcy concentration and a reduced percentage of high tHcy levels in elderly subjects. They also support the use of dietary pattern approaches to evaluate the relationships between diet and health outcomes that go beyond single nutrient analyses.

Aged↗
PubMed2003

Cloning and characterization of human complement component C7 promoter.

To study the transcriptional regulation of the human complement component C7, a 1 kb promoter fragment was cloned and the transcription start site was determined. C7 is expressed by the hepatoma-derived cell line Hep-3B, but not by Hep-G2. Transfection of these cell lines with different C7 promoter-luciferase constructs demonstrated that 1 kb of the 5'-flanking region contains the necessary elements for driving C7 transcription in a tissue-specific manner and showed that the sequence between -29/+102 retained the majority of C7 promoter activity in Hep-3B. Electrophoretic mobility shift assays suggested that the binding of the C/EBPalpha transcription factor to a C/EBP sequence located at +42 is essential for C7 expression. To investigate whether the absence of C/EBPalpha expression in Hep-G2 cells is responsible for the lack of C7 transcription, Hep-G2 cells were transfected with a C/EBPalpha expression vector. C/EBPalpha transactivated the C7 luciferase reported gene and restored the C7 expression in Hep-G2 cells.

Base Sequence↗
PubMed2003

Adhesion of probiotic lactobacilli to chick intestinal mucus.

In the present work, interactions between three Lactobacillus strains (Lactobacillus fermentum CRL1015, Lactobacillus animalis CRL1014, and Lactobacillus fermentum CRL1016) and chicken small intestinal mucus were determined. Three lactobacilli isolated from chicken and selected by their potentially probiotic properties were able to grow in mucus preparations. Three peaks from gel filtration chromatography of intestinal mucus were obtained. The adhesion to three mucus fractions (I, II, and III), especially fraction III, was higher (P < 0.01) in L. fermentum CRL1015 than L. animalis CRL1014. Pretreatment of this fraction with proteases and metaperiodate showed lower (P < 0.01) adhesion values than that of the control, suggesting that a glycoprotein from the mucus acts as a receptor for L. fermentum CRL1015. Highest adhesion values were obtained at pH 7 and 42 degrees C, and neither the removal of divalent cations with ethylenediaminetetraacetic acid (EDTA) nor the addition of calcium produced significant variation from the adhesion values of the control (P > 0.01). This adhesion was only inhibited by N-acetyl-glucosamine. Salmonella pullorum and Salmonella gallinarum showed high (P < 0.01) values of adhesion to chick intestinal mucus. The results obtained from assays of the inhibition of adherence of Salmonella spp. to mucus, immobilized in polystyrene tissue culture wells, indicated that the pathogen adhesion was not reduced by lactobacilli (P > 0.05) or their spent culture supernatants (P > 0.05), suggesting that these strains did not interfere with the binding sites for Salmonella spp. adhesion to the small intestinal mucus.

Animals↗
PubMed2003

Expression of CCAAT/enhancer-binding protein-beta (C/EBPbeta) and CHOP in the murine growth plate. Two possible key modulators of chondrocyte differentiation.

Our aim was to evaluate the expression of transcription factors CCAAT/enhancer-binding protein-beta (C/EBPbeta) and C/EBP-homologous protein (CHOP) in the growth plate. Proximal tibial epiphyseal growth plates from ten 15-day-old Wistar rats were used. Additionally, anti-proliferating cell nuclear antigen (PCNA), anti-5-bromo-2'-deoxyuridine (BrdU) immunostaining, terminal transferase dUTP nick end-labelling (TUNEL) and nucleolar organiser region-associated proteins (AgNOR) techniques were peformed. The histological morphology of the growth plate from C/EBPbeta knock-out mice was also analysed. The normal growth plate showed that C/EBPbeta and CHOP factors are expressed both in the germinative/ upper proliferative and in the lower proliferative zones. Furthermore, BdrU+ and PCNA+ cells were present exclusively in the germinative and proliferative zones, while TUNEL+ and AgNOR+ cells were seen in all three zones of the growth plate. Acellular areas, hypocellularity, the increase in cell death and anomalies in the architecture of the cell columns were observed in the growth plates of C/EBPbeta (-/-) knockout mice. We suggest that C/EBPbeta and CHOP transcription factors may be key modulators participating in the chondrocyte differentiation process in the growth plate.

Animals↗
PubMed2003

Chronic administration of losartan reverses cardiovascular changes in hypertensive fructose-fed rats.

The cluster of risk factors including hyperinsulinemia, insulin resistance, hypertriglyceridemia and hypertension has been called syndrome X. Several evidences link the insulin resistance syndrome with endothelial dysfunction. Since the participation of the renin-angiotensin system (RAS) in this pathology is still unclear, the present study examined the effect of chronic administration of an angiotensin AT1 receptor antagonist, losartan (L), on endothelial nitric oxide synthase (eNOS) activity in aortic endothelium and cardiac tissue, and on the proliferation of primary cultured aortic smooth muscle cells (SMC), obtained from fructose-fed rats (FFR), an experimental model of syndrome X Male Wistar rats were used: Control, FFR and FFR+L (n = 8 in each group). After 8 weeks, tissue samples were obtained and 10% fetal calf serum (FCS) proliferative effect was examined in SMC by 3H-thymidine incorporation and cell counting. The eNOS activity was estimated in aortic endothelial lining and cardiac homogenates by conversion of 3H-arginine into 3H-citrulline. FFR aortic SMC showed a significantly increased 10% FCS-induced 3H-thymidine incorporation and cell number compared to controls. FFR aortic and cardiac eNOS activities were significantly decreased. Chronic treatment with L decreased systolic blood pressure,reverted cardiac hypertrophy, abolished the increased SMC proliferation and restoredeNOS activity. These data confirm that changes in SMC proliferation and endothelial dysfunction at different levels of the cardiovascular system are involved in syndrome "X", and that AT1 receptor blocking can revert those changes, suggesting an important role of the RAS, possibly mediated by AT2 receptors and kinins, in the physiopathological mechanisms of this model.

Angiotensin II↗
PubMed2002

Examination of adhesive determinants in three species of Lactobacillus isolated from chicken.

The microbial adhesion process includes passive forces; electrostatic interactions; hydrophobic, steric forces; lipoteichoic acids; and specific structures, such as external appendages (lectins) and (or) extracellular polymers. In a previous work, we showed that Lactobacillus animalis, L. fermentum, and L. fermentum ssp. cellobiosus had lectinlike proteic structures on their surfaces and high hydrophobicity values on the cell surface of L. fermentum ssp. cellobiosus. Here, we examined the presence of the bacterial forces or structures that could be involved in the interaction between bacteria and epithelial cells. Lactobacillus animalis and L. fermentum possessed a net negative surface charge, whereas L. fermentum ssp. cellobiosus showed similar affinity to both cationic and anionic exchange resins, aggregated in the presence of ammonium sulfate, and had high affinity (75.4%) to a hydrophobic matrix. Only L. animalis was shown to have ribitol teichoic acids in the cell wall. The amount of polysaccharides from cell walls varied between different strains, with L. fermentum ssp. cellobiosus having the highest concentration. Lectin extracts obtained from lactobacilli did not possess sugar residues, thereby demonstrating the proteic nature of the superficial surface structures of three strains. The lactic acid bacteria studied here showed different surface determinants, which could be involved in the interactions between these lactobacilli and intestinal epithelial cells.

Animals↗
PubMed2001

Design, synthesis and biological evaluation of novel arachidonic acid derivatives as highly potent and selective endocannabinoid transporter inhibitors.

In the present work, we have designed and synthesized a series of arachidonic acid derivatives of general structure I which have been characterized as highly potent and selective inhibitors of anandamide transporter (IC(50) = 24-0.8 microM, K(i) > 1000-5000 nM for CB(1) and CB(2) cannabinoid receptors and vanilloid VR(1) receptor). Among them, N-(3-furylmethyl)eicosa-5,8,11,14-tetraenamide deserves special attention as being the most potent endocannabinoid transporter inhibitor (IC(50) = 0.8 microM) described to date.

Animals↗
PubMed2001

Glucocorticoid effects on Fos immunoreactivity and NADPH-diaphorase histochemical staining following spinal cord injury.

Glucocorticoids (GC) provide neuroprotection and early recovery after spinal cord injury (SCI). While several mechanisms were proposed to account for these effects, limited information exists regarding GC actions in sensory areas of the spinal cord. Presently, we studied the time course of Fos expression, and reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemical staining to monitor neuronal responses to SCI with or without GC treatment. Rats with sham-operation or transection at the thoracic level (T7-T8) received vehicle or 5 mg/kg of the GC dexamethasone (DEX) at 5 min post-lesion and were sacrificed 2 or 4 h after surgery. Another group of SCI rats received vehicle or intensive DEX treatment (5 min, 6 h, 18 h and 46 h post-lesion) and were sacrificed 48 h after surgery. The number of NADPH-d positive neurons or Fos immunoreactive nuclei was studied by computer-assisted image analysis in superficial dorsal horn (Laminae I-III) and central canal area (Lamina X) below the lesion. While constitutive Fos immunoreactive nuclei were sparse in controls, SCI increased Fos expression at 2 and 4 h after injury. DEX treatment significantly enhanced the number of Fos positive nuclei in Laminae I-III by 4 h after transection, although the response was not maintained by intensive steroid treatment when tested at 48 h after SCI. NADPH-d positive neurons in Laminae I-III increased at 2 and 4 h after SCI while a delayed increased was found in central canal area (Lamina X). DEX treatment decreased NADPH-d positive neurons to sham-operated levels at all time points examined. Thus, while GC stimulation of Fos suggests activation of neurons involved in sympathetic outflow and/or pain, down-regulation of NADPH-d indicates attenuation of nociceptive outflow, considering the role of enzyme-derived nitric oxide in pain-related mechanisms. Differential hormonal effects on these molecules agree with their localization in different cell populations.

Animals↗
PubMed2001

Effect of P64k presensitization on its efficacy as an immunological carrier in mice.

Recently, we have successfully employed the meningococcal P64k protein as a carrier for weak immunogens. Here, we study if presensitization with it can affect the murine antibody response against the hapten chemically coupled to P64k. We found that priming with 10 microg of P64k did not induce epitope-specific suppression against two out of three synthetic peptides, from viral proteins, conjugated to this carrier. Depending on the anti-carrier antibody titers elicited in the presensitized mice, we observed or not a suppressed immune response against the third peptide. Presensitization with 100 microg of P64k resulted in epitope-specific suppression when lower doses of conjugate were administered. In summary, as described for other protein carriers, P64k could induce epitope-specific suppression in mice, but it depends on the hapten and the extent of carrier-specific immunity. Furthermore, this suppression can be overcome by increasing the amount of conjugate administered per dose in the presensitized animals.

Amino Acid Sequence↗
PubMed2001

K-ras and p16 aberrations confer poor prognosis in human colorectal cancer.

PURPOSE: Mutations in the K-ras gene are frequent in human cancer. ras activation in primary cells results in a cellular senescence phenotype that is precluded by inactivation of p16. At the clinical level, this may imply a differential behavior for tumors with alternative or cooperative activation of K-ras function and impairment of p16 pathways. PATIENTS AND METHODS: We have determined the presence of mutations in the K-ras gene and the methylation status of p16 promoter in a series of 119 prospectively collected colorectal carcinomas. p53 mutations and p14 alternative reading frame methylation status were also assessed. Associations with survival were investigated. RESULTS: K-ras mutations were present in 44 (38%) of 115 cases, and p16 methylation was present in 42 (37%) of 113 cases. p53 mutations were detected in 50% (56 of 115) and p14 methylation in 29% (32 of 112) of cases. K-ras and p16 alterations were independent genetic events. Presence of K-ras or p16 genetic alterations (analyzed independently) was associated with shorter survival, although differences were not statistically significant. Cox analysis of the two variables combined showed a diminished survival as the results of an interaction between p16 and K-ras. Alternative alteration of K-ras and p16 genes was an independent prognostic factor in human colorectal cancer in univariate and multivariate analysis. Differences were maintained when cases undergoing radical surgery and without distant metastases were considered. CONCLUSION: These results suggest that the combined K-ras and p16 analyses may be of prognostic use in human colorectal cancer.

Adenocarcinoma↗
PubMed2001

Relationship between atmospheric pressure and mortality in the Madrid Autonomous Region: a time-series study.

This study set out to determine the possible influence of variations in atmospheric pressure on mortality in the Madrid Autonomous Region (MAR), taking into account the possible confounding effect of other atmospheric variables. The study was based on daily mortality data from the MAR Revenue and Excise Authority, meteorological data from Getafe Observatory and air pollution data from the Madrid Municipal Automatic Air Pollution Monitoring Grid. A time-series analysis was performed, using Box-Jenkins modelling and controlling for the respective confounding variables. Furthermore, the different variables studied (pressure, temperature, pollutants, etc.) were used to produce a multivariate model of the different causes of mortality. A significant association was found between anticyclonic trend and mortality with circulatory causes in the medium-long term and anticyclonic trend and mortality with respiratory causes in the long term.

Air Pollution↗
PubMed2001

Polymorphism in MICA rather than HLA-B/C genes is associated with psoriatic arthritis in the Jewish population.

The aim of this study was to examine whether the association of psoriatic arthritis (PsA) with human leukocyte antigen (HLA) class I genes is secondary to linkage disequilibrium with a nearby gene. We examined a sample of the Jewish population to investigate whether HLA-B/C and DR polymorphism is associated with susceptibility, or whether other closely related class I loci, such as the major histocompatibility complex class I chain-related gene A (MICA) and tumor necrosis factor (TNF), might play a role in disease development. Comparisons of different populations with different HLA profiles would be of value in identifying the candidate genes involved in PSA. Fifty-two patients with PsA and 73 random matched controls from a Jewish population were selected and DNA typed by polymerase chain reaction-single-strand oligonucleotide probe (PCR-SSOP) (HLA-C), PCR sequence-specific primers (PCR-SSP) (HLA-B, -DR), radioactive PCR (MICA-TM polymorphism in the transmembrane region), and PCR-RFLP (TNF). Some findings can be concluded from the study: (1) the frequency of HLA-B*5701, B*3801, B*39, B*27, Cw*0602, Cw*07, DRB1*0402, and DRB1*0701 were not found to be significantly increased in PsA; (2) no significant differences of TNFalpha promoter alleles at positions -308 and -238 were found between PsA and healthy controls; (3) the trinucleotide repeat polymorphism MICA-A9 was present at a higher frequency in PsA patients, (p(c) < 0.009, RR = 3.34, EF = 0.39); and (4) MICA-A9 polymorphism was found in linkage disequilibrium with HLA-B alleles (B*5701, B*3801) described to be associated with PsA in Caucasians. These results suggest that the MICA gene or other nearby gene(s) may be involved in the development of PsA, and it would thus appear that psoriasis vulgaris (PsV) and PsA are associated with different MHC susceptibility genes.

Adult↗
PubMed2001

Genetic variability, molecular evolution, and geographic diversity of HLA-B27.

HLA-B27 represents a family of 23 closely related alleles (B*2701-23) that differ at 24 amino acid positions. The pattern of polymorphisms of B27 was studied, with special reference to synonymous (Ks) and nonsynonymous (Ka) divergence among alleles. B27 alleles are characterized by the enhanced rate of nonsynonymous nucleotide substitution in the peptide-binding region (PBR). The percentage of substitutions between each of the B27 pairs ranges from 0.2%-3% in exons 2-3 to 1.8%-20.1% in the PBR. A phylogenetic analysis of all B27 alleles is described in order to identify subtypes with a common evolutionary history. These results, together with the phylogenetic trees obtained from the comparison between exons 2-3 and PBR indicate that polymorphism of B27 is selectively maintained. Most of the differences are clustered in the C/F pocket affecting the specific binding of antigenic peptides. Gene conversion and point mutation are the most important mechanisms responsible for B27 diversification. The interaction of selection, genetic drift, and recombination events is important for generating polymorphism at B27 alleles. We analyzed a large extended B27 positive population from different parts of the world. Our results indicate that B27 subtypes differ in their ethnic distribution, which may be the result of different genetic and geographical origins. Different factors such as genetic drift, bottleneck effect, and admixture among populations could contribute to the genetic constitution of B27. The striking correlation between the structural features of B27 and the ethnic distribution of these subtypes suggests a model of strong directional evolution, in which the subtypes could have arisen from B*2705.

Africa↗
PubMed2001

[Pediatric lung resection. A case series and evaluation of postoperative lung function].

The most common causes of pulmonary lobectomy in children are congenital lung malformations (CLM) and bronchiectasias. Our aim was to present the causes and clinical course and lung function of lobectomized patients. Between 1990 and July 1999 27 lobectomies were performed on patients whose ages ranged from newborn to 14 years. Lobectomies were performed to correct CLM in 124 cases and for acquired pulmonary disease (APD) in 13. Among CLM cases, half (n = 7) had cystic adenomatoid malformation. Among the APD patients, 10 had bronchiectasias, with etiological confirmation in 6 cases (3 secondary to serious adenovirus infection). Mean hospital stay was 4.6 days among those who experienced no postoperative complications. Symptoms resolved after surgery for most symptomatic patients. Lung function tests could be carried out with 8 patients over 6 years old whose operations had taken place 7 to 78 months earlier (x = 35 months) and whose age at the time of surgery was a mean 7 years 6 months (range 60 to 144 months). Spirometry showed normal forced vital capacity for 7 of 8 patients (87 to 143% of theoretical value). Arterial oxygen saturation measured during and after a 6-minute walking test was normal for 7 of 8 patients. Chest films showed reduced lung volume on the affected side in 5 of 8 patients. In summary, lobectomy is a procedure with few complications. It requires a short hospital stay and has good postoperative prognosis. Function and x-ray studies show adequate lung growth and development, with normal lung function in those who could be so examined because they were old enough to cooperate.

Adolescent↗
PubMed2001

Aortic smooth muscle cell proliferation and endothelial nitric oxide synthase activity in fructose-fed rats.

The aim of this study was to evaluate the proliferative behavior of vascular smooth muscle cells in primary culture (pC-SMC) and the endothelial nitric oxide synthase (eNOS) activity in the endothelial lining of the aorta of fructose-fed rats (FFR). This is an experimental model of syndrome X, a cluster of cardiovascular risk factors including hyperinsulinemia, insulin resistance, and hypertension that has been suggested to be of pathophysiologic importance for the development of atherosclerosis. Male Wistar rats were used: Control (n = 12) and FFR (n = 12). After receiving fructose in drinking water (10% w/v) during 8 weeks, biochemical parameters, systolic blood pressure (SBP) and relative heart weight (RHW) were determined. The proliferative effect of 10% fetal calf serum (FCS) was examined in aortic pC-SMC by [3H]thymidine incorporation and by cell counting. Ca2+/calmodulin-dependent NOS activity was estimated in aortic endothelial lining and in heart tissue homogenates by conversion of [3H]arginine into [3H]citrulline. Fructose-fed rats showed hyperinsulinemia (P = .0263), altered glucose tolerance test (P < .001), higher SBP (P < .0001), and RHW (P = .0145), compared to control rats. These animals also showed an increase of 10% FCS-induced [3H]thymidine incorporation (P < .0001) and cell number of aortic pC-SMC (P = .0049) and decreased eNOS activity in both aortic endothelium (P = .0147) and cardiac tissue (P < .0001). These data support the hypothesis that syndrome X is associated to changes in SMC proliferation and endothelial dysfunction, which could be involved in the onset or progression of the atherogenic process.

Animals↗