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Biomedical subjects

A Blanco

Publications and source records attributed to A Blanco.

At least 91 records · Page 5Linked to original sources
PubMed1998

Bezafibrate and lovastatin decrease the oxidizability of low-density lipoproteins in heart transplant recipients with hyperlidemia.

BACKGROUND: Oxidized low-density lipoprotein plays an important role in the development of atherosclerosis. We evaluated the effect of two lipid-lowering drugs, bezafibrate and lovastatin, on the susceptibility of low-density lipoproteins for oxidation in vitro in 21 heart transplant recipients with hyperlipidemia. METHODS: Patients were given the same diet for 3 months, and after that they were randomized to lovastatin or bezafibrate for a period of 8 weeks and then crossed over to an additional 8 weeks of either bezafibrate or lovastatin. Baseline parameters were also compared with those of a control group of healthy subjects and after both periods of pharmacologic treatment. RESULTS: The low-density lipoproteins of transplant recipients presents a shorter lag time than in control subjects (64+/-3 vs 80+/-4 minutes, respectively). This parameter increases after both bezafibrate and lovastatin treatment (83+/-5 and 80+/-4 minutes, respectively). Moreover, we did observe a negative correlation between insulinemia and the lag time of oxidation after bezafibrate treatment (r = -0.5014, P < .021) and between the polyunsaturated fatty acids/monounsaturated fatty acids ratio in low-density lipoprotein cholesterol esters and lag time after lovastatin treatment (r = -0.4631, P < .04). CONCLUSIONS: Bezafibrate and lovastatin decrease the oxidizability of low-density lipoproteins in heart transplant recipients with hyperlipemia.

Bezafibrate↗
PubMed1997

Genomic organization and phylogenetic relationships in the genus Dasypyrum analysed by southern and in situ hybridization of total genomic and cloned DNA probes.

Molecular cytogenetic methods have been used to study the controversial phylogenetic relationships between the species Dasypyrum villosum (L.) Candargy (2n=2x=14) and D. breviaristatum (Lindb. f.) Frederiksen (2n=4x=28). Using total genomic DNA from the two species as probes for in situ hybridization to chromosomes, we found that the pericentromeric regions of the chromosome arms of both species are similar, while distal regions show substantial differences. Two dispersed repetitive DNA sequences were isolated: pDbKB45 is distributed along the chromosomes but amplified in the subtelomeric regions of D. breviaristatum chromosomes, while pDbKB49, in both species, is less amplified in terminal regions. Size-separated restriction enzyme digests of DNA showed many repetitive fragments, but few in common between the two species. After probing Southern transfers with D. breviaristatum genomic DNA, all lanes showed similar hybridization patterns although one extra small band was evident in the D. breviaristatum lanes. In contrast, probing with D. villosum DNA showed very substantial differences between the two species. Genomic in situ hybridization to meiotic metaphases from an interspecific hybrid showed seven bivalents of D. breviaristatum origin and seven univalents from D. villosum. We also analysed the physical organization of 5S rDNA, 18S-25S rDNA and a tandemly repeated sequence from rye. Our data support an autotetraploid origin for D. breviaristatum, but its genome and that of D. villosum show extensive differences, so the tetraploid is unlikely to be directly derived from D. villosum.

Base Sequence↗
PubMed1997

Temporal variation of allozyme frequencies in Aedes albifasciatus (Diptera: Culicidae) from Argentina.

Aedes albifasciatus is a floodwater mosquito widely distributed in Argentina. It is important from economic and medical points of view. A 4-year survey of seasonal variation in allele frequencies in a population of this species was undertaken to determine possible changes in the genetic structure and their correlation with environmental conditions. Significant temporal variation was detected at most of the loci, but it did not follow a cyclic or seasonal pattern. Multivariate analysis of principal components showed a remarkable homogeneity of samples collected from December 1993 to April 1995 and a clear differentiation of the November 1991, March 1992, and November 1993 samples. This variation could be correlated with the magnitude of rainfall occurring in the area. Passive transport of larvae by water streams and river freshets produced by floods would have mixed larvae from breeding sites with different allele frequencies, causing the genetic differentiation observed.

Aedes↗
PubMed1997

Influence of the SstI polymorphism at the apolipoprotein C-III gene locus on the plasma low-density-lipoprotein-cholesterol response to dietary monounsaturated fat.

The plasma lipid response to changes in dietary fat and cholesterol can vary between individuals. The SstI polymorphism, arising from a cytosine to guanosine substitution in the 3' untranslated region of the APOC3 gene distinguishes between two alleles--S1 and S2. The S2 allele has been associated with elevated plasma triacylglycerol, cholesterol, and apolipoprotein (apo) C-III concentrations. In 90 young men we examined the effect of the same mutation on the response of low-density-lipoprotein (LDL) cholesterol to dietary monounsaturated fat. The frequency for the S2 allele was 0.14. Subjects were fed a low-fat diet for 25 d, followed by a diet rich in monounsaturated fatty acid (22% MUFA, 38% total fat) for 28 d; lipoproteins were measured at the end of each diet. There were no significant differences in initial total cholesterol between subjects with the APOC3*S1/APOC3*S1 (S1/S1) and APOC3*S1/APOC3*S2 (S1/S2) genotypes. After consumption of the diet high in MUFA, significant increases in LDL cholesterol (0.13 mmol/L, P < 0.027) were noted in the S1/S1 subjects whereas a significant decrease was observed in the S1/S2 subjects (-0.18 mmol/L, P < 0.046). Significant genotypic effects were seen for diet-induced changes in LDL cholesterol (P < 0.00034), total cholesterol (P < 0.009), and apo B (P < 0.0014). A study of the effect of the interaction between this mutation with that present in position -76 of the APOA1 gene promoter region (G/A) revealed that both mutations had an additive effect on changes in total cholesterol, LDL cholesterol, and apo B induced by diets. Plasma LDL-cholesterol responsiveness to the diet may be explained, at least in part, by variation at the APOC3 gene locus.

Adult↗
PubMed1997

Concomitant treatment with a 5-lipoxygenase inhibitor improves the anti-inflammatory effect of the inhibition of nitric oxide synthase during the early phase of endotoxin-induced uveitis in the rabbit.

Nitric oxide (NO) synthase inhibitors, such as NG-nitro-L-arginine methyl ester (L-NAME), have been shown to attenuate endotoxin-induced uveitis (EIU) but they could increase leukocyte adhesion to the vascular endothelium. We hypothesize that a concomitant treatment with the 5-lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) in 50% dimethylsulfoxide (DMSO, a hydroxyl radical scavenger) could improve the anti-inflammatory activity of L-NAME. EIU was induced in albino rabbits by intravitreal injection of 100 ng lipopolysaccharide. Animals were treated with multiple intraperitoneal injections of 50% DMSO in phosphate-buffered saline (PBS), NDGA (10 mg/kg) in 50% DMSO, L-NAME (50 mg/ kg) in PBS, or the combination NDGA+L-NAME. Uveitis was assessed by slit lamp examination, protein levels in aqueous humor, and myeloperoxidase (MPO) activity in the iris/ciliary body 6 h after induction. Nitrite, leukotriene B4 (LTB4), prostaglandin E2 (PGE2), platelet-activating factor (PAF) and interleukin-1 beta (IL-1 beta) levels in aqueous humor were also determined. NDGA or L-NAME alone did not show a significant reduction of uveitis intensity, although a significant decrease in MPO or in proteins was found, respectively. The combination NDGA+L-NAME significantly reduced the uveitis intensity, MPO in the iris/ciliary body, and the levels of nitrites, LTB4, PGE2, and PAF in aqueous humor. IL-1 beta levels were lower than the detection limit of the radioimmunoassay in all treatment groups. We conclude that concomitant treatment with NDGA in DMSO improves the anti-inflammatory activity of L-NAME during the early phase of EIU, suggesting that the inhibition of NO synthesis could enhance leukocyte infiltration and the release of oxygen free radicals.

Administration, Topical↗
PubMed1997

Effect of 347-serine mutation in apoprotein A-IV on plasma LDL cholesterol response to dietary fat.

Lipid response to dietary fat and cholesterol is, to a large extent, genetically controlled. Apoprotein (apo) A-IV has been related to fat absorption and to the activation of some of the enzymes involved in lipid metabolism. One mutation has been described in the apo A-IV gene that causes substitution of Ser for Thr at position 347. To study the influence of this mutation on the plasma LDL cholesterol (LDL-C) response in diets of various fat content and fatty acid saturation, 41 healthy male subjects were studied, 25 of whom were homozygous for the Thr allele (347Thr) and the rest who were either homozygous (n = 2) or heterozygous carriers of the Ser allele (347Ser). They consumed three consecutive diets, each of 4 weeks' duration: one rich in saturated fat (SFA diet: 38% fat, 20% saturated), a National Cholesterol Education Program (NCEP) type 1 diet (28% fat, 10% saturated), and a third rich in monounsaturated fat (MUFA diet; 38% fat, 22% monounsaturated). Carriers of the 347Ser allele presented a greater decrease in total cholesterol (-0.7 vs -0.44 mmol/L, P < .034), LDL-C (-0.62 vs -0.31 mmol/L, P < .012), and apo B (-14 vs -8 mg/dL, P < .01) levels when they were switched from the SFA to the NCEP type 1 diet than homozygous carriers of the 347Thr allele. The change from the NCEP type 1 to the MUFA diet resulted in a greater increase in total cholesterol (0.18 vs -0.05 mmol/L, P < .028) and apo B (5 vs -1 mg/dL, P < .006) levels in the 347Ser than in the 347Thr individuals. In a previous study, we demonstrated that the G-->A polymorphism at position -76 of the gene promoter of apo A-I affects the LDL-C response to dietary fat. We therefore decided to study the effect of the interaction between these mutations on this response. We found that both mutations have an additive effect on total cholesterol, LDL-C, and apo B dietary-induced changes. Our results suggest that total cholesterol and LDL-C response to dietary fat is influenced by the 347Ser mutation of apo A-IV.

Adult↗
PubMed1997

[Diagnosis of centronuclear myopathy in adults].

INTRODUCTION: Centro-nuclear myopathy is a congenital myopathy characterized by the presence of central nuclei on muscle biopsy. Three clinical forms have been distinguished. Classification depends on the type inherited, age of onset and degree of muscle involvement. CLINICAL CASE: We describe the case of a female patient in whom the diagnosis of centro-nuclear myopathy was made at the age of 53. The patient had not been studied previously, but was sent to us by the Department of Anaesthesia. The clinical features had first appeared in infancy. There was no family history of this disorder. Apparently this was a sporadic case. CONCLUSIONS: In the differential diagnosis of adult patients with girdle paresthesias centro-nuclear myopathy should be included. This unusual muscle disorder may be need to be considered if anaesthesia is required.

Diagnosis, Differential↗
PubMed1997

Effect of 360His mutation in apolipoprotein A-IV on plasma HDL-cholesterol response to dietary fat.

In order to determine whether genetic variability of apolipoprotein (apo) A-IV is responsible for the improvement in lipid profile when dietary saturated fats are replaced by carbohydrates or monounsaturated fats, 41 healthy male subjects were studied: 33 were homozygous for the 360Gln allele and 8 were heterozygote carriers of the 360His allele. These were administered three consecutive 4-week diets. The first was a diet rich in saturated fat (SAT diet, with 38% fat, 20% saturated. This was followed by a low fat diet (NCEP-I, with < 30% fat, < 10% saturated). The final diet was rich in monounsaturated fat (MUFA diet, with 38% fat, 22% monounsaturated). There was no difference in plasma lipid and apolipoprotein levels of both groups of individuals after consuming the SAT diet. Switching from this diet to the NCEP-I diet, carriers of the 360His allele presented a greater decrease in high density lipoprotein-cholesterol (HDL-C) (-10 vs. -1 mg/dL, P < 0.004) and apoA-I levels (-19 vs. -8 mg/dL, P < 0.037). Similarly, replacement of carbohydrates by monounsaturated fats produced a greater increase in HDL-C (9 vs. 1 mg/dL, P < 0.003) and apoA-I levels (9 vs. 2 mg/dL, P < 0.036) in carriers of the 360His mutation. Lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) activities and apoA-IV levels were also measured. However, no genotype-related differences were observed for these parameters. Our results suggest that variability in HDL-C and apoA-I response to diet is, at least partially, determined by the 360His mutation of apoA-IV.

Adult↗
PubMed1997

Effects of acute and subchronic cadmium administration on pituitary hormone secretion in rat.

Cadmium administration is known to be followed by deleterious effects on the endocrine system although its action mechanism is not well understood. The purpose of this study was to determine, in vivo, the effects of acute and/or subchronic cadmium chloride administration (6 mg/kg or 4 mg/kg/day during 14 days) on prolactin, luteinizing hormone (LH), follicle stimulating hormone (FSH), growth hormone (GH) and thyroid stimulating hormone (TSH) secretion in adult male rats. Six h after a single injection of CdCl2, a diminution of plasma levels of prolactin (4.52 +/- 0.53 vs. 16.2 +/- 2.7 ng/mL, p < 0.01), GH (3.39 +/- 0.41 vs. 6.71 +/- 1.30, ng/mL, p < 0.01), TSH (2.76 +/- 0.64 vs. 7.65 +/- 1.15 ng/mL, p < 0.01) and LH (4.1 +/- 1.3 vs. 5.18 +/- 0.28, p < 0.05) was observed, where as plasma FSH levels did not change. On the other hand, subchronic cadmium chloride administration for 14 days, increased plasma levels of GH (13.39 +/- 2.74 vs. 6.71 +/- 1.3 ng/mL, p < 0.05), TSH (27.8 +/- 4.42 vs. 6.65 +/- 1.15 ng/mL, p < 0.001), LH (11.1 +/- 1.3 vs. 5.18 +/- 0.28 ng/mL, p < 0.001) and FSH (53.16 +/- 3.66 vs. 12.51 +/- 1.45, p < 0.001), whereas plasma prolactin levels decreased (6.86 +/- 1.38 vs. 16.2 +/- 2.7 ng/mL, p < 0.01). In animals subchronically treated with CdCl2, body weight gain was lower than in control rats (p < 0.001). The present findings suggest that acute and subchronic cadmium administration modify pituitary hormone secretion differentially and specifically.

Animals↗
PubMed1996

Cloning of a Bacillus sp. BP-23 gene encoding a xylanase with high activity against aryl xylosides.

The xynB gene encoding a xylanase from the recently isolated Bacillus sp. strain BP-23 has been cloned and expressed in Escherichia coli. The enzyme produced in this host shows a molecular size of 41 kDa and a pI of 4.5. The pH and temperature at which the highest activity was found were 5.5 and 50 degrees C respectively. Crude xylanase B showed activity on xylan, aryl xylosides, xylotetraose and xylotriose, while xylobiose was not hydrolyzed by the enzyme. Xylanase B showed high specific activity on aryl xylosides, probably as a result of the transxylosidase activity detected.

Bacillus↗
PubMed1996

Frequency of intergenerational contractions of the CTG repeats in myotonic dystrophy.

Myotonic dystrophy (MD), an autosomal dominant multisystemic disorder with a high phenotypic variability, is the most common muscular dystrophy in adult life. The mutation underlying DM has been characterized as an expanded CTG trinucleotide repeat sequence in the 3 untranslated region of a protein kinase gene on chromosome 19q13.2-13.3. We have analyzed the presence of CTG intergenerational variations on transmission in parent-child pairs affected with DM. The series includes 90% of all living affected descendants (symptomatic or asymptomatic) from a given myotonic dystrophy (DM) patient. A contraction of the CTG repeat size was observed in ten parent-child pairs (14.1%) and remained unchanged in five (7%) pairs. The number of CTG repeats decreased in 2/30 maternal transmissions (6.7%) and in 8/41 paternal transmissions (19.5%). We found 14 asymptomatic individuals carrying the CTG expansion among the offspring. In six of them, a contraction of the CTG repeat was observed, and in all six cases, the DM allele was paternally transmitted. Since nearly all the asymptomatic family members of DM patients were analyzed in this series, the observed percentage of contractions can be considered more realistic, even though the number of parent-child pairs is small.

Adult↗
PubMed1996

[Teachers' attitudes toward smoking prevention at schools].

Teenage smoking continues to present a significant public health problem. Children begin to smoke in elementary and middle school, although consumption is highest during university studies. In spite of their limitations, school-based campaigns are the most effective weapons against smoking. Spanish educational authorities have developed an interdisciplinary anti-smoking curriculum for health education. In practice, however, the curriculum is not usually implemented. An understating of teachers' attitudes toward such campaigns can lead to their better design, contributing to greater cooperation and better outcome. We therefore surveyed teachers participating in the School-based Smoking Prevention Plan during 1993-1995. Teachers had a generally favorable opinion of the campaign and wanted to continue it; they were well disposed to cooperate more actively with the physicians who carried it out.

Adult↗
PubMed1996

Presence of antibodies in the aqueous humour and cerebrospinal fluid during Leishmania infections in dogs. Pathological features at the central nervous system.

In the present paper we show that in dogs, naturally infected with Leishmania infantum, the aqueous humour and the cerebrospinal fluid contain anti-Leishmania IgGs and that the specificity of antigen recognition of these fluids is similar to that of the sera. We also show that in the encephalon and cerebellum of these dogs there is a pathological sponge-like reaction accompanied by neuronal degeneration, mobilization of glial cells together with accumulation of amyloid deposits. The interstitial and intravascular deposition of IgGs and Leishmania antigens in choroid plexus suggest that in these animals there is a failure of the blood-cerebrospinal and ciliary bodies filtration barriers which may allow the transfer of anti-Leishmania IgGs from the blood stream to these fluids. We suggest that the failure of the blood-cerebrospinal barrier and the in situ concentration of anti-Leishmania IgGs and antigens in brain tissues may predispose to the pathological features detected in this compartment.

Animals↗
PubMed1996

Immunopathology of the uveitis in canine leishmaniasis.

Particular immunopathological features and their effects on the vascular permeability of different ocular structures were analysed in two dogs naturally infected by Leishmania infantum. The existence of specific anti-Leishmania immunoglobulin G (IgG) in the aqueous humour was confirmed by the ELISA technique. There was no correlation between antibody levels in the aqueous humour and the related serum. The histopathological study of the eyes showed the existence of lesions in various ocular structures. The ciliary processes, ciliary body, sclerocorneal limbus, iris and lacrimal duct showed intense inflammatory zones with lymphocyte infiltrates, plasmatic cells and macrophages with amastigote forms of Leishmania. In addition vasculitis with dilation and thrombi were also detected in both cases, with consequent oedema and hyalinization. The immunohistochemistry analysis revealed the presence of granular and diffuse IgG deposits in the ciliary body, ciliary processes, sclerocorneal limbus and iris. Furthermore, numerous thrombosed vessels were observed in the sclerocorneal zone and iris. Complement 3 (C3) fraction deposits were not present in the ocular structures. The present data suggest that the ocular lesions may have an immunopathological origin.

Animals↗
PubMed1996

Genetic structure of Aedes albifasciatus (Diptera:Culicidae) from a marsh ecosystem in Córdoba, Argentina.

Allozymic variability was analyzed for 8 samples of the floodwater mosquito Aedes albifasciatus (Macquart) obtained in October and November 1993 from marsh and pasture habitats along the Mar Chiquita ecosystem in central Argentina. Expected mean heterozygosity among 17 loci was low. Fls values were negative for all polymorphic loci, and mean FST values were low, indicating high levels of gene exchange and the absence of subpopulations within the 25-km-wide study area. Genetic homogeneity throughout the area suggests that outcrossing occurs frequently as a result of dispersal among sampled sites.

Aedes↗