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Biomedical subjects

A Blanco

Publications and source records attributed to A Blanco.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Content and bioavailability of carotenoids from peach palm fruit (Bactris gasipaes) as a source of vitamin A].

Four introductions of ripe peach palm fruit (Bactris gasipaes) were analyzed for ether extract, total carotenoids and their biological conversion into vitamin A. Also, edible portion in cooked fruit was estimated. Ether extract content in raw fruit ranged from 8.2 to 12.9% dry basis (DB), cooked between 5.7 to 12.4% DB and nutrient retention after cooking was 69 to 100%. Carotenoids content in raw and cooked pejibaye was similar, 4.8 to 29.6% DB and 4.8 to 29.9% DB, respectively, giving a nutrient retention after cooking greater than 85%. Average edible portion was 68 +/- 2%. The biological study showed significant differences (p < 0.05) of pejibaye carotenoids efficiency conversion in retinol, the values varied from 14 to 50%. Food efficiency results in the control and experimental diets were not statistically significant (p > 0.05). Carotenoids content was inversely related (r = -0.8, p < 0.02) with ether extract. Cooking had no significant effect in ether extract and carotenoids content, except in one introduction. Based in the results generated in the study and vitamin A Recommended Daily Allowances (RDA) it was estimated that one, in three introductions and seven in the remaining one satisfies an adult RDA's.

Animals↗
PubMed1992

Characterization of the nuclear receptors of triiodothyronine (T3) by immunocytochemistry under electron microscopy.

By immunocytochemical methods, using colloidal gold particles coupled to antibodies, it is possible to label the occupied nuclear T3 receptors and observe them by electron microscopy. We carried out some experiments to validate these methods by testing the absence of non-specific binding of the antibodies to subcellular structures different from the T3 receptors. So, we have verified that the number of occupied T3 receptors in tissues from normal rats is lower in kidney cells than in heart and liver ones, a finding which is an agreement with data reported by others. The occupation of the receptors increases after T3 administration and decreases by triiodothyroacetic acid (Triac) administration to the rats, due to the displacement of T3 from the receptors with the latter. Our results are similar to those of the other authors using radioactive tracers. Non-specific binding was not detected. The occupied T3 receptors labelled with colloidal gold particles are located most commonly in the hetero/euchromatin interface. From our results we conclude that the colloidal gold particles observed by electron microscopy specifically label occupied T3 receptors, and the determination of the thyroid status at cellular level can be achieved using electron microscopy after labelling the receptors by immunocytochemistry with colloidal gold particles coupled to antibodies.

Animals↗
PubMed1992

Evaluation of immune complexes after immunotherapy with wheat flour in bakers' asthma.

Inhalant food allergy has been described many times in literature, but double-blind clinical trials to support successful hyposensitization to these allergens has seldom been reported. Some authors have suspected that certain adverse reactions after immunotherapy may be mediated by immune complexes. Furthermore, the FDA does not recommend injection therapy with food extracts. We present a study on the detection of adverse effects after immunotherapy with an inhalant food (wheat flour) in a double-blind clinical trial in 26 patients with bakers' asthma. We investigated the presence of circulating immune complexes (CICs) after 2 years of treatment with hyposensitization to wheat flour.

Antigen-Antibody Complex↗
PubMed1991

Overproduction of a Clostridium cellulolyticum endoglucanase by mutant strains of Escherichia coli.

We have studied the expression of an endoglucanase from Clostridium cellulolyticum in mutant strains of Escherichia coli that overproduce haemolysin. When these mutants were transformed with plasmids encoding the endoglucanase, they showed a significantly enhanced endoglucanase activity, compared to transformed parental strains. Among the mutants, strain Hha-2 showed the highest production. We have identified the endoglucanase gene product synthesized in E. coli Hha-2/pBP8 and detected an increased amount of the enzyme parallel to the increase of endoglucanase activity. This was mainly localized in the periplasm and only a small percentage of it was found in the culture fluid.

Cellulase↗
PubMed1991

Microgeographic distribution of allele frequencies in populations of Calomys laucha (Rodentia, Cricetidae).

The microgeographic differentiation of allelic frequencies was analysed in two population samples of Calomys laucha, collected in a grid set in cultivated fields at Laguna Larga (Córdoba province, Argentina). One of the samples (n = 79) was obtained in May (Autumn), when the population density is at a maximum, and the other (n = 85) in November (spring), at the onset of reproductive activity. FST values for the November sample show significant differences between the six groups over which the sample was divided. FIT values show an excess of homozygotes for some loci in both samples. FIS reveals an excess of homozygotes within each of the groups. These results indicate the existence of subdivision in the population. Because C. laucha is a reservoir host of the Junin virus, an agent of endemic disease, this social organization may have epidemiological implications. Stratification of C. laucha populations into small breeding units could be one of the factors responsible for the high genic variability detected in this species.

Alleles↗
PubMed1991

Occurrence and evolution of T3 fibroblast nuclei in healing tendons from growing chicks.

We applied immunocytochemical techniques including anti-triiodothyronine (T3) serum and microscopic analysis with colloid gold as the developer to identify the specific receptors of thyroid hormones located within the cell nucleus and between the heteroeuchromatin transition zone in 25 chicks. All chicks underwent tenotomy, followed by tenorrhaphy and immobilisation of the leg in plaster. There was a gradual decrease in the number of T3 receptors of collagen-forming fibroblasts as the tendons healed and their capacity to synthetize collagen diminished.

Animals↗
PubMed1991

[Functional significance of the serum/saliva testosterone ratio in various diseases].

Serum/salivary testosterone ratio (ST/SlvT) expresses the relationship in absolute values between bound and unbound testosterone. This ST/SlvT ratio in supposedly healthy men (n = 25) and women (n = 72) and in patients with several disorders, prostatic carcinoma (n = 19), varicocele (n = 9) and hirsute women (n = 16), has been studied. Both serum and salivary testosterone were measured by an RIA method. ST/SlvT ratio values found in healthy men (78.4 +/- 30.9) did not differ significantly from values found in the varicocele group (111.1 +/- 49.3), but a significant difference (p less than 0.001) from those found in men with prostatic carcinoma (12.3 +/- 7.2) was observed. When the ST/SlvT ratio values obtained in healthy women (18.1 +/- 7.3) were compared with those obtained in hirsute women (1.56 +/- 5.7) no significant differences were observed. The results obtained may indicate the dissociation among the hormone transport, testosterone metabolic clearance and hormone secretion by the salivary glands.

Adult↗
PubMed1991

[Bioavailability of amino acids in beans (Phaseolus vulgaris)].

Biological availability of amino acids of three common bean (Phaseolus vulgaris) varieties was evaluated in four, healthy adult subjects, consuming bean-based diets by the amino acid absorption technique and the short-term nitrogen balance method. The amino acid composition was determined according to the ionic interchange method, and tryptophan was estimated by a colorimetric procedure. The essential amino acid (EAA) and non-essential amino acid (NEAA) pattern suggests that no significant differences in content exists in the three bean varieties. When the EAA patterns were compared with those of FAO/WHO, the limiting AA in decreasing order were found to be: tryptophan, valine and threonine (sulfur AA are not considered because the hydrolysis used in this study destroys them); and the AA surpassing the reference pattern were the aromatic AA and isoleucine. Apparent (AD) and true (TD) digestibilities of the EAA fluctuated between 33 and 59% and 60 and 85%, respectively, for black beans. With red beans, these results diminished: 29 and 55% AD and 64 and 81% TD, while for white beans the limits extended: 18 and 57% AD and 36 and 86% TD. Valine proved to be the EAA of lower biological availability, and lysine and phenylalanine the most available. It is suggested that the low digestibility of valine could be due to the amino acid imbalance existing in the bean protein, since this contains an excess of isoleucine and leucine in relation to valine. The AD and TD of the AAE with respect to the NEAA were of 0.89 and 0.98 for black bean, 0.89 and 0.96 for the red and 0.77 and 0.90 for the white, which indicates that biological availability of the NEAA is higher than that of the EAA. Findings thus confirm that biological determination of the TD of protein permits prediction of the TD of the AA, since a positive correlation (r = 0.93) statistically significant was found (p less than 0.05) among them. Utilization of the TD parameter instead of that of AD to estimate the protein quality is therefore recommended.

Adult↗
PubMed1990

[Deficiency of prostacyclin stimulating factor in type I diabetes mellitus. Correlation with the duration of the disease].

The prostacyclin stimulating plasma factor (PSPF) was studied in 40 children affected by insulin dependent diabetes (type I), using smooth muscle cells of rat aorta as substrate. The patients were divided into three groups according to the duration of the disease; recently diagnosed patients (n = 10), patients with less than 5 years of evolution (23 cases), and patients with more than 5 years duration (n = 7). The most significant data were that all the patients with more than 5 years duration had decreased PSPF with values below I SD (p less than 0.001). No statistically significant differences were found among the group with less than 5 years duration, recently diagnosed patients and the normal control group. Neither could a correlation be found between the value of PSPF and the dose of insulin required by each patient, or the rate of hyperglycemia, triglycerides, cholesterol and Hb A1C.

Adolescent↗
PubMed1990

Congenital factor XIII deficiency associated with von Willebrand disease.

A boy with umbilical bleeding and severe hemorrhages after minor trauma, without family bleeding history, was studied. Coagulation tests showed abnormalities in FXIII subunits and FVIII/vWF complex. Both parents presented results compatible with a heterozygote state for FXIII deficiency and the father had abnormalities of FVIII/vWF. The propositus was diagnosed as congenital FXIII deficiency associated with vWD. No severe hemorrhagic complication was observed after a prophylactic regimen with cryoprecipitates.

Factor XIII Deficiency↗
PubMed1990

Protein polymorphism and genetic distance in South American cricetid rodents of the genus Calomys.

Allozymic variation in population samples of Calomys laucha, C. musculinus and C. venustus collected simultaneously from the province of Córdoba, Argentina, was analyzed by gel electrophoresis. These three species showed high levels of polymorphism: for C. laucha, the P value was 72.7% and the H value was 0.147 (19 loci); for C. musculinus, P = 61.9% and H = 0.149 (20 loci); for C. venustus, P = 66.7% and H = 0.146 (18 loci). These species are non-fossorial generalists, have a high reproductive rate and live in disturbed habitats. The similarity indices (S) range between 0.613 and 0.681. On the basis of genetic distance, D (between 0.354 and 0.476), divergence time was estimated to be from 6.3 to 8.5 million years (late Miocene). Even admitting some imprecision for this estimate, the remarkable differences at the structural gene level shown by the species analyzed, suggest they had an early origin.

Alleles↗
PubMed1990

Heterozygosity and gene flow in populations of Calomys laucha (Rodentia, Cricetidae).

Enzyme polymorphism was studied by means of starch gel electrophoresis on five population samples of Calomys laucha collected in different sites and seasons. C. laucha, a cricetid rodent inhabiting preferentially cultivated fields in the central-eastern plains of Argentina, is a reservoir-host of Junin virus, agent of Argentine hemorrhagic fever. Results show high levels of genic variability in all the samples (P from 62.50 to 77.27; H from 0.118 to 0.163) and low genetic distance among populations (D from 0.0024 to 0.0167). Estimations of gene flow (mean Nm = 10.78) indicate a high migration capability of the species and the possibility of further dispersal of Junin virus.

Animals↗