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Biomedical subjects

A Blanco

Publications and source records attributed to A Blanco.

At least 55 records · Page 3Linked to original sources
PubMed2001

Genetic relationships among Aedes aegypti (Diptera: Culicidae) populations from Argentina using random amplified polymorphic DNA polymerase chain reaction markers.

Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) polymorphism was analyzed in five Aedes aegypti (L.) populations from Argentina and one from Puerto Rico to estimate levels of intraspecific polymorphism and genetic relatedness. Allele frequencies were estimated assuming that RAPD products segregate as dominants and that genotype frequencies at those loci are in Hardy-Weinberg equilibrium. Mean expected heterozygosity (He) was 0.350; F(ST) values were significant at all loci except one, supporting the usefulness of the fragments used here to discriminate among populations. Rogers' genetic similarity between samples ranged from 0.806 to 0.621. The population from Puerto Rico was the most different from the Argentina populations. Considering that Ae. aegypti eggs, larvae, and pupae can be transported easily, relationships among the Argentinian populations may reflect the routes and intensity of commercial transit.

Aedes↗
PubMed2001

[Prevalence of nutritional anemia in women of reproductive age. Costa Rica. National nutrition survey, 1996].

In 1996, The Ministry of Health and Inciensa conducted the latest National Nutrition Survey, to provide support and guidance to the national policies, plans and programs in the field of food and nutrition. The present paper reports the results for the prevalence of anemia estimated in a total of 884 women of reproductive age, in three areas: metropolitan area, other urban areas and rural areas. Anemia was determined through measurements of hemoglobin, plasma ferritin and plasma folates. In addition, hemoglobin patterns were determined by electrophoresis. The cutt-off points used were those recommended by the WHO. Anemia was present in 18.6% of the women. Severe to moderate deficiency of iron (< 12 ng/dl) and of folates (< 6 ng/dl) were found in 43.2 and 24.7% of women respectively, with statistically significant differences by area of residence. The magnitude of the problem for anemia can be classified as mild, for iron deficiency as severe, and for folate deficiency as moderate. In conclusion, Anemia represents a public health problem for Costa Rica that has remained constant throughout the last decade. In women of reproductive age, iron deficiency is the main cause of Anemia, followed by folates deficiency, and in a small percentage hemoglobinopathies. Intestinal parasites are not longer a mayor cause of Anemia. Prevalence of Anemia is influenced by place of residence, but not by age. In summary, despite the favorable health conditions present in Costa Rica, the prevalence of Anemia and of iron deficiency are similar to those of the Latin-American region. To improve this situation, public health interventions are necessary.

Adolescent↗
PubMed2001

[Prevalence of anemia, iron and folate deficiency in children 7 years smaller. Costa Rica, 1996].

In 1996, were studied in Costa Rica 961 children with ages between one and six years, with representation for metropolitan, urban and rural zones of the country. The classification approaches applied were emitted by the Pan-American Health Organization and the World Health Organization. The preschooler population presented in the national environment a prevalence of anemia of 26.3% (children from 1 to 4 years with hemoglobin < 11.0 g/dL and those from 5 to 6 years old with hemoglobin < 12.0 g/dL). The prevalence of Iron depletion (Ferritin < 12 ng/mL) and iron deficiency (Ferritin < 24 ng/mL) were 24.4% and 53.8%, respectively. The folate deficiency (< 6.0 ng/mL) was 11.4%. The iron deficiency was higher in children smaller than 4 years, being the maximum deficiency in the 1 year-old (75%). More than 40% of the preschool children presented sub-clinical deficiency of iron; of them, 10% showed severe deficiency of iron without presence of anemia. The children from the rural area presented the highest prevalence of anemia and iron depletion, while the metropolitan area met more frequency with iron deficiency. The nutritional anemias still constitute a moderate problem of public health in Costa Rica. The main cause is iron deficiency, associated in small proportion with folate deficiency and other factors associated with the erythropoiesis.

Anemia↗
PubMed2001

Flow cytometry in the bone marrow evaluation of follicular and diffuse large B-cell lymphomas.

BACKGROUND AND OBJECTIVES: Bone marrow biopsies are routinely performed in the staging of patients with lymphoma. Despite the lack of evidence for its usefulness, many institutions include flow cytometry (FC) of bone-marrow aspirates in an attempt to increase sensitivity and specificity. The aim of this study is to evaluate the usefulness of FC for the assessment of bone-marrow involvement by lymphoma in follicular (FL) and diffuse large B-cell lymphomas (DLBCL). DESIGN AND METHODS: Seventy-nine bone marrow biopsies from 65 patients diagnosed with FL or DLBCL were examined to compare histology and FC for the assessment of bone-marrow involvement by lymphoma. RESULTS: Bone marrow histology showed involvement (BM+) in 16 cases (20.3%), lack of infiltration (BM(-)) in 52 cases (65.8%) and undetermined or undiagnosed for involvement (BMu) in 11 cases (13.9%). FC was positive for involvement in 28 cases (35.4%) and negative in 51 cases (64.6%). 65 cases (95%) showed concordance between the results of morphology and FC (BM(+)/FC(+) or BM(-)/FC(-)). No BM(+)/FC(-) cases were observed. 3 cases showed discrepant results (BM(-)/FC(+)). In these 3 cases the molecular studies (PCR) demonstrated clonal rearrangement of the heavy immunoglobulin chain (IgH) and/or bcl2-IgH in agreement with the flow results. Among the 11 cases with BMu, all but 2 were FC(+) and concordance with the PCR results was seen in 9 cases (81.9%). INTERPRETATION AND CONCLUSIONS: We conclude that FC is just as sensitive or perhaps slightly more sensitive than histology in the detection of bone marrow involvement in FL and DLBCL. FC studies may be warranted in those cases in which the morphology is not diagnosed. The clinical relevance of the small clonal B-cell population in patients without histologic bone marrow involvement (BM(-)/FC(+) cases) remains an open question.

Bone Marrow↗
PubMed2000

Stereological study of the adrenal gland of calves treated with clenbuterol.

Stereological methods were used to investigate the morphometric variations in the adrenal cell population of calves dosed orally with clenbuterol at an anabolic dose of 20 microg/kg bodyweight per day for 12 weeks. In the treated group the size of the nuclei increased with respect to the control group, and the increases were significant for the maximum linear parameters in all the regions except the zona fasciculata. The largest increases were observed in the epinephrine-producing cells. The quantitative stereological data showed highly significant increases in the nuclear volume fraction, the nuclear surface density and the numerical density in the zona fasciculata of the treated group.

Adrenal Glands↗
PubMed2000

Large-scale synthesis of a silicon photonic crystal with a complete three-dimensional bandgap near 1.5 micrometres

Photonic technology, using light instead of electrons as the information carrier, is increasingly replacing electronics in communication and information management systems. Microscopic light manipulation, for this purpose, is achievable through photonic bandgap materials, a special class of photonic crystals in which three-dimensional, periodic dielectric constant variations controllably prohibit electromagnetic propagation throughout a specified frequency band. This can result in the localization of photons, thus providing a mechanism for controlling and inhibiting spontaneous light emission that can be exploited for photonic device fabrication. In fact, carefully engineered line defects could act as waveguides connecting photonic devices in all-optical microchips, and infiltration of the photonic material with suitable liquid crystals might produce photonic bandgap structures (and hence light-flow patterns) fully tunable by an externally applied voltage. However, the realization of this technology requires a strategy for the efficient synthesis of high-quality, large-scale photonic crystals with photonic bandgaps at micrometre and sub-micrometre wavelengths, and with rationally designed line and point defects for optical circuitry. Here we describe single crystals of silicon inverse opal with a complete three-dimensional photonic bandgap centred on 1.46 microm, produced by growing silicon inside the voids of an opal template of dose-packed silica spheres that are connected by small 'necks' formed during sintering, followed by removal of the silica template. The synthesis method is simple and inexpensive, yielding photonic crystals of pure silicon that are easily integrated with existing silicon-based microelectronics.

Journal Article↗
PubMed2000

Invisible mycosis fungoides: A diagnostic challenge.

We describe a 76-year-old woman who presented persistent generalized pruritus as the only cutaneous manifestation of a cutaneous T-cell lymphoma (mycosis fungoides). No cutaneous lesions were observed throughout the patient's course. Skin biopsies obtained from normal-looking pruritic skin revealed a discrete perivascular lymphocytic infiltrate in the upper dermis and focal intraepidermal clusters of atypical lymphoid cells (Pautrier's microabscesses). PCR analysis of TCR-gamma gene disclosed a monoclonal T-cell rearrangement. Sequencing of the PCR monoclonal product identified the J(8)V(2)C(2) TCR gene rearrangement. This observation illustrates the existence of a peculiar and exceedingly rare form of mycosis fungoides characterized only by persistent pruritus unresponsive to several therapeutic approaches. The diagnostic difficulties of this rare variant are stressed.

Aged↗
PubMed2000

estA, a gene coding for a cell-bound esterase from Paenibacillus sp. BP-23, is a new member of the bacterial subclass of type B carboxylesterases.

Screening of a gene library from Paenibacillus sp. BP-23 generated in Escherichia coli led to identification of a clone that directed the production of lipolytic activity. From the sequencing data, we found an open reading frame encoding a protein of 485 amino acids with an estimated molecular mass of 53 kDa and a pI of 5.1. Absence of a signal peptide indicated that it was a cell-bound protein. Sequence analysis showed that the protein contained the signature G-XI-S-X2-G included in most serine-esterases and lipases. The cloned protein showed high homology with enzymes belonging to the bacterial subclass of type B carboxylesterases. The enzyme had a significant preference for esters of short-chain fatty acids and showed the kinetics behaviour of a true esterase. Maximum activity was found at pH 7.5 and 37 degrees C, although the enzyme was active in the pH range 6.0- 9.0 and at temperatures up to 45 degrees C. As expected for a serine-esterase, activity was inhibited by phenylmethylsulphonyl fluoride.

Amino Acid Sequence↗
PubMed2000

Comparison of an oleic acid enriched-diet vs NCEP-I diet on LDL susceptibility to oxidative modifications.

OBJECTIVE: The objective of this trial was to compare the effect on the susceptibility of plasma Low Density Lipoprotein (LDL) to oxidative modifications of consumption of two oleic rich diets, prepared with two different plant oils, virgin olive oil (OL)1 and refined high monounsaturated fatty acids (MUFA sunflower oil (SU)), with the susceptibility of plasma LDL to oxidation after an National Cholesterol Education Program step 1 (NCEP-I) phase diet. DESIGN: A randomized crossover design. SUBJECTS AND INTERVENTIONS: Twenty-two healthy normolipidemic young males consumed an NCEP-I diet for a 4-week period. Subjects were then assigned to two diets each of 4-weeks duration. Group one was placed on an olive oil enriched diet (40% fat, 22% MUFA) followed by a 4-week period of a MUFA diet enriched in sunflower oil (40% fat, 22% MUFA). In group two, the order of the diets was reversed. RESULTS: Both MUFA diets induced a decrease in saturated (14:0, 16:0, and 18:0) and an increase in monounsaturated and polyunsaturated n-6 (18:2, 20:3, and 20:5) plasma LDL-phospholipid fatty acids, compared to the NCEP-I diet (P<0.01). No significant differences in lag times were observed between the olive oil and the NCEP-I diet periods. However there was a greater inhibition time (P<0.001) when subjects consumed the MUFA rich sunflower oil diet compared to the NCEP-I diet. These differences were probably related to the relative enrichment of plasma LDL particles in alpha-tocopherol due to the high vitamin E content of the MUFA-rich sunflower oil. Indeed, the alpha-tocopherol content was positively correlated with lag time (r=0.338; P<0.008). CONCLUSION: Our findings suggest that changes in plasma LDL alpha-tocopherol content with practical solid-food diets can decrease its susceptibility to oxidation. SPONSORSHIP: This work has been supported by grants from the Investigaciones de la Seguridad Social (FIS 92/0182, to Francisco Pérez Jiménez); and from Koype Co, Andújar, Jaén, Spain. European Journal of Clinical Nutrition (2000) 54, 61-67

Adult↗
PubMed2000

[Stuttering as the only manifestation of a cerebral infarct].

A 53-year-old right-handed man acutely developed stuttering. On his examination there was blocks and repetitions exclusively on first syllables of words in conversational speech, improving in automatic tasks. There was neither aphasia, nor other neurological deficits. An MR imaging of the brain showed a circumscribed cortical infarct on the left precentral circunvolution. Cerebral angiography was consistent with atherosclerotic narrowing of the intracavernous segment of left internal carotid artery. Artery-to-artery embolism was the suggested mechanism for this stroke and the patient was treated with oral anticoagulants for six months. Stuttering improved progressively and the patient became asymptomatic a month after the stroke. Ictal acquired stuttering symptomatic of ischemic stroke without aphasia or other neurological deficit is exceptional. An small infarct on the left motor area as cause of isolated acquired stuttering adds new information about neural circuits involved in this phenomenon.

Cerebral Angiography↗
PubMed1999

[The diet rich in monounsaturated fat modifies in a beneficial way carbohydrate metabolism and arterial pressure].

OBJECTIVE: Two dietary regimens recommended for the reduction of coronary risk, by way of their effects on lipid profile, are the diet low in saturated fat and a diet rich in monounsaturated fats (MUFA). However the effects of these diets on carbohydrate metabolism in healthy subjects are not well known. The objective of this study was to compare the effect of both diets on various parameters of carbohydrate metabolism. METHODS: 41 healthy young males were submitted to 3 consecutive diets, each for a duration of 4 weeks. The first diet was rich in saturated fat (SAT) (38% fat, 20% saturated). The second was rich in carbohydrates following the recommendations of the NCEP-I (National Cholesterol Education Program type I) (28% fat, 47% carbohydrates). The last one was a diet rich in monounsaturated fatty acids (38% fat, 22% MUFA). At the end of each dietary period, blood pressure (BP) and blood levels of glucose, insulin and free fatty acids were determined. 29 subjects were also submitted to an oral glucose tolerance test (OGTT) at the end of each diet. RESULTS: The SAT diet induced the highest levels of insulin after the OGTT. The consumption of the MUFA diet determined the lowest levels of fasting blood glucose (-0.60 mmol/l [13%], p < 0.0002), insulin (-9 microUl/ml [47%], p < 0.0002) and free fatty acids (-0.11 mmol/l [24%], p = 0.006), compared to the NCEP-I diet. Systolic and diastolic blood pressure were higher in the NCEP-I diet than during the other periods (SBP: +6 mmHg compare with SAT [5%], p = 0.0001; and +5 mmHg compare with MUFA [4%], p = 0.0001; DBP: +20 mmHg compare with MUFA [27%], p = 0.0001) and +6 mmHg compared with SAT [8%], p = 0.0001). CONCLUSION: Of the diets most commonly used for the treatment and prevention of arteriosclerosis, a diet rich in monounsaturated fats is the most beneficial for the healthy population from the point of view of carbohydrate metabolism and blood pressure.

Adult↗
PubMed1999

Proportion of S-phase tumor cells measured by flow cytometry is an independent prognostic factor in meningioma tumors.

Meningiomas are tumors in arachnoid cells which represent up to one fifth of all intracranial tumors and up to a quarter of spinal neoplasias. Although meningiomas have classically been considered to be benign tumors, it has also been well-established that they show a heterogeneous clinical outcome. To the best of our knowledge no study has yet been performed in which the independent prognostic value of both DNA ploidy and cell cycle has been simultaneously assessed in a large series of meningioma tumors. The aim of the present study was to prospectively explore the prognostic value of DNA ploidy status and the proliferative rate of tumor cells in a series of 105 consecutive meningioma patients studied at diagnosis. Both the presence of DNA aneuploidy and the proportion of S-phase tumor cells were analyzed in all cases in fresh tumors obtained during diagnostic surgery. From the technical point of view, we followed the recommendations of the Consensus Conference on Flow Cytometry DNA Analysis held in October 1992. Our results show that meningioma tumors display a relatively low incidence of DNA aneuploidy (14%), and they usually show a low proliferative rate (mean percentage of S-phase cells of 1.3 +/- 0.3%). The presence of DNA aneuploidy was associated with a higher incidence of aggressive histopathologic subtypes (P = 0.045), a greater age (P = 0.009), location at the cerebral convexity (P = 0.004), and a greater proportion of S-phase cells (P = 0.005). In contrast, no significant association between the DNA ploidy status of meningioma patients and their disease-free survival was found (P = 0. 1). Regarding the proliferative activity of neoplastic cells, we found that a high proportion of S-phase cells (>1.8%) was associated with a significantly lower mean age (P = 0.007), aggressive histopathologic subtypes (P = 0.03), a higher incidence of DNA aneuploidy (P = 0.004), and a significantly shorter disease-free survival (P < 0.004). Multivariate analysis of prognostic factors showed that the proportion of S-phase tumor cells was the most powerful independent prognostic factor in meningioma patients (P = 0.02). In summary, we conclude that the proportion of S-phase tumor cells represents the individual parameter with the highest value for predicting disease-free survival in meningioma patients.

Adolescent↗
PubMed1999

[The Mediterranean diet improves the profile of male smokers compared with the diet recommended by the American Cholesterol Program (NCEP-I)].

BACKGROUND: A study of the effect of smokers' diets on their atherogenic lipidic profile. SUBJECTS AND METHODS: 41 healthy males (32 non-smokers and 9 smokers) consumed consecutively a diet low in fat and rich in carbohydrates (28% total fat content < 10% saturated fats, and 57% carbohydrates), and a diet rich in monounsaturated fatty acids (38% total fat content with 22% monounsaturated fats). At the end of each dietary period, adhesion was confirmed by quantification of LDL cholesterol esters, plasma lipids and insulin levels. RESULTS: There were no significant differences between the age or the body mass of the groups of smokers or non-smokers. After both diets tobacco was found to have a significant effect on triglyceride levels (p < 0.0007), HDLc (p < 0.007), apo A-I (p < 0.02) and the LDLc/HDLc ratio (p < 0.005), revealing an interaction between diet and both HDLc levels (p < 0.004) and LDLc/HDLc ratios (p < 0.003). With the low fat and high monounsaturated fatty acid content diets smokers presented higher triglyceride levels (both with p < 0.0002) and LDLc/HDLc ratios (p < 0.0002 and p < 0.05, respectively) and lower levels of apo A-I (p < 0.002 and p < 0.004, respectively). However, in smokers the HDLc levels were only reduced after the low fat diet (p < 0.0003) and after the diet with a high monounsaturated fat content there was a rise in HDLc levels (p < 0.02) and a drop in the LDLc/HDLc ratio (p < 0.005) compared to the group of non-smokers. There were no significant differences in the insulin levels between groups. CONCLUSION: The atherogenic lipidic profile of smokers is due to an effect of tobacco on the lipidic metabolism. This atherogenic profile is accentuated with a low fat diet rich in carbohydrates and can be rectified to some degree with a diet with a high monounsaturated fatty acid content.

Adult↗
PubMed1999

Spectrum of CFTR mutations in the Middle North of Spain and identification of a novel mutation (1341G-->A). Mutation in brief no. 252. Online.

We have analyzed 39 unrelated cystic fibrosis (CF) families by denaturing gradient gel electrophoresis (DGGE) and direct sequencing in order to determine the spectrum of CF mutations in our population. This approach has allowed us to detect 72 out of the 78 CF chromosomes (92.3%). The DF508 mutation was found to be present in 51/78 (65.4%) CF chromosomes, in accordance with the predicted Northwest-Southeast gradient within the European population. Another 14 known mutations, and the novel 1341G-->A mutation were identified. Nine out of fifteen non DF508 mutations were present in a single chromosome. The 1341G-->A mutation, found in 2 unrelated patients, is a new mutation associated to severe phenotype, causing pancreatic insufficiency and chronic lung infections. Our data suggest a different distribution of non-DF508 mutations in our population when compared with previous studies carried out in Spanish CF families. Six out of the 14 non-F508 in our study were not present in a recent study carried out in 640 Spanish families with CE These six mutations account for 29.6% non DF508 chromosomes in our sample.

Cystic Fibrosis↗