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Biomedical subjects

G de la Fuente

Publications and source records attributed to G de la Fuente.

16 recordsLinked to original sources
PubMed2006

Effect of the cryopreservation conditions on the viability of the rumen ciliate Diploplastron (Metadinium) affine.

AIMS: To study the viability of Diploplastron (Metadinium) affine after its cryopreservation at two cooling rates, and the effect of procedure conditions on viability. METHODS AND RESULTS: There were differences in viability between cooling rates (1 and 4 degrees C min(-1)) at 15 or 5 degrees C, but not after thawing. When the equilibrium temperature (25 or 5 degrees C), the cryopreservant (glycerol or dimethyl sulfoxide [DMSO]) and the use of membrane protector were tested, there were no differences caused by the cryopreservant or the membrane protector. However, the equilibrium at 25 degrees C increased the viability (P = 0.005) compared with 5 degrees C. CONCLUSIONS: Viability after thawing was 0.10-0.19. Adding the cryopreservant (either glycerol or DMSO) at 25 degrees C instead of 5 degrees C improves viability of D. affine after thawing. SIGNIFICANCE AND IMPACT OF THE STUDY: Conditions of cryopreservation are largely dependent on the species of rumen protozoa. Number of viable cells after thawing would indicate the possibility of culture recovery for D. affine.

Animals↗
PubMed2004

A cryopreservation procedure for the rumen protozoon Entodinium caudatum: estimation of its viability by fluorescence microscopy.

AIMS: To study the viability of a culture of the rumen protozoon Entodinium caudatum after a cryopreservation procedure by a fluorescence microscopy staining method. METHODS AND RESULTS: Fluorescence method is based on the different colour of cells depending on their membrane integrity. When the temperature effect was studied either by fluorescence or motility, the techniques were correlated (r = 0.727) and their slopes and intercepts were not different (P > 0.05). However, motility showed a higher variation coefficient (0.40 vs 0.12). There were no differences between cooling rates at cryopreservation (1 and 4 degrees C min-1) at 38, 15 or 5 degrees C, nor after thawing. CONCLUSIONS: Fluorescence staining is more accurate than motility for assessing protozoal viability. Viability after thawing was 0.50, and the number of viable cells per 250 microl straw was 320 and 420 for 1 and 4 degrees C min-1. SIGNIFICANCE AND IMPACT OF THE STUDY: This cryopreservation procedure seems to ensure culture recovery for E. caudatum.

Animals↗
PubMed1995

[Isolation of Coxsackieviruses B5 in a fatal case of meningoencephalitis].

A nine months old boy was admitted to the hospital with the diagnosis of meningoencephalitis 15 days after having a clinically diagnosed chickenpox. Lumbar puncture showed clear CSF with 0.23 g/l of proteins, 57 mg/dl of glucose, 30 red cells/mm3 and 5 leukocytes/mm3. Blood count showed a packed red cell volume of 22%, a hemoglobin of 7 g/dl, 14800 leukocytes with 1% eosinophils, 5% band and 39% segmented neutrophils, 50% lymphocytes and 5% monocytes and a decreased platelet count. On the fourth hospitalization day, the patient had vomiting, irritability and stiff neck. A new lumbar puncture showed a clear CSF that differed from the former only in the glucose level that increased to 102 mg/dl. The patient died and the necropsy showed a congestive and enlarged brain and congestive meninges infiltrated with lymphocytes. There was lymphoid follicle hyperplasia in the small bowel and enlarged mesenteric lymph nodes. Samples of brain, brain stem, spinal cord and stools were sent for virological study. A Coxsackie B-5 virus was isolated from the spinal cord sample.

Brain↗
PubMed1994

Effect of Penicillium chrysogenum on Lignin Transformation.

A strain of Penicillium chrysogenum has been isolated from pine forest soils in Tenerife (Canary Islands). This strain was capable of utilizing hydroxylated and nonhydroxylated aromatic compounds, in particular cinnamic acid, as its sole carbon source. In an optimum medium with high levels of nitrogen (25.6 mM) and low levels of glucose (5.5 mM), it was able to decolorize Poly B-411 and to transform kraft, organosolv, and synthetic dehydrogenative polymerisate lignins. After 30 days of incubation, the amount of recovered kraft lignin was reduced to 83.5 and 91.3% of that estimated for uninoculated controls by spectrophotometry and klason lignin, respectively. At the same time, the pattern of molecular mass distribution of the lignin remaining in cultures was changed. The amount of organosolv lignin recovered from cultures was reduced to 90.1 and 94.6% of the initial amount as evaluated by spectrophotometry and klason lignin, respectively. About 6% of total applied radioactivity of OCH(3)-organosolv lignin was recovered as CO(2) after 30 days of incubation, and 18.5% of radioactivity from insoluble OCH(3)-organosolv lignin was solubilized. After 26 days of incubation, 2.9% of C-beta-dehydrogenative polymerisate and 4.1% of C-ring-dehydrogenative polymerisate evolved as CO(2).

Journal Article↗
PubMed1992

Tris discriminates between the different alpha-glucosidase activities from extracts of human neutrophils.

In an attempt to detect acid maltase deficiency in neutrophils from patients with type II glycogenosis, without interference from the 'renal' alpha-glucosidase activity present in these cells, we have evaluated the contribution of the renal component in the total activity measured at pH 4.0 in extracts of human neutrophils. The renal contribution is about 13-25% and renal glucosidase appears to be closely related to the enzyme present on the epithelium of small intestine, which is known to be inhibited by Tris. We have used this compound as a selective inhibitor of the renal component of alpha-glucosidase activity measured at pH 4.0 in total extracts of neutrophils. Our results demonstrate that 0.1 mol/L Tris is an inhibitor of the renal alpha-glucosidase present in neutrophils and can be used to reduce the interference from this enzyme in assays of acid maltase.

Glycoside Hydrolase Inhibitors↗
PubMed1990

[The etiopathogenesis of the acute stress ulcer. The role of oxygen free radicals].

We evaluated the role of oxygen free radicals in the induction of acute stress gastric ulcer in rats. After 12 hr of immobility, ulcers of up to 4 mm were observed in the gastric mucosa. Pretreatment with allopurinol, a xanthine oxidase inhibitor, produced a significant reduction in the number and size of lesions (p < 0.0001). No protection was afforded by aluminum hydroxide or ranitidine alone, but enhanced protection was observed when given in association to allopurinol. A secondary role for H ions is suggested by these findings. Our results support the hypothesis of a role of oxygen free radicals in the pathogenesis of stress gastric ulcers. Allopurinol might be used in conditions predisposing to stress in patients.

Acute Disease↗
PubMed1989

ColV increases the virulence of Escherichia coli K1 strains in animal models of neonatal meningitis and urinary infection.

Isogenic Escherichia coli strains, differing in their expression of K1 antigen and ColV plasmid, were studied for their ability to produce disease. Newborn rats were used to test the ability of these strains to colonize the intestine and to produce bacteremia and meningitis; adult rats were used to test their ability to produce urinary tract infection. Colonization of intestine and bladder by K1+ ColV+ E. coli was associated with rapid induction of bacteremia and higher mortalities compared with colonization with K1+ ColV- strains. These findings suggest that the ColV plasmid could play a role in the pathogenesis of human infections.

Animals↗
PubMed1987

Purification and characterization of a lectin from Phaseolus acutifolius var. latifolius.

The lectin from Phaseolus acutifolius var. latifolius has been purified to homogeneity by affinity chromatography using stroma-sephadex, gel filtration and electrofocusing. The purified lectin consists of four subunits of 21 Kd molecular mass each one with 7.4% w/w total carbohydrate. Red cells of human and animal species, are agglutinated but are not inhibited by a series of sugars. Mitogenicity and immunosuppressive activities were demonstrated. Agglutination requires magnesium and calcium ions.

Amino Acids↗
PubMed1977

Some Nutritional Characteristics of a Naturally Occurring Alga (Microcystis sp.) in a Guatemalan Lake.

The nutritional characteristics of an alga (Microcystis sp.) that occurs naturally in a Guatemalan lake were determined. The sun-dried material proved to have a high protein content (55.6%) and to be a possible good source of calcium and phosphorus (1, 169.1 and 633.4 mg/100 mg, respectively). Amino acid analysis showed that total sulfur amino acids were the most deficient ones, giving a protein score of 42 to the material. The in vitro protein digestibility of the material was 69.5%. Biological trials demonstrated that when the material was offered as the only protein source, very low consumption and a high mortality rate were obtained whether or not the diet was supplemented with 0.4% dl-methionine. However, when the material supplied 25% of the total protein of a corn-algae diet, the protein quality of the cereal was significantly improved (P < 0.05).

Journal Article↗