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C Asensio

Publications and source records attributed to C Asensio.

At least 19 recordsLinked to original sources
PubMed1998

[The role of PET-FDG in questionable diagnosis of relapse in the presence of radionecrosis of brain tumors].

INTRODUCTION: Although CT and MR are sensitive techniques for the detection of cerebral tumours, both have limitations in distinguishing between tumour relapse (TR) and post-treatment radionecrosis (RN). PATIENTS AND METHODS: In this study we have determined the usefulness of metabolic imaging with PET-FDG in such situations. We assessed 70 patients with CNS tumours (22 low grade astrocytomas, 25 high grade astrocytomas, 3 oligodendrogliomas, 13 metastatic tumours and 7 other tumours. All had been treated with radiotherapy and other treatments such as radiosurgery, chemotherapy or different types of surgery, and presented clinical pictures which made it necessary to decide the differential diagnosis of relapse or radionecrosis. RESULTS: In the PET-FDG study visual and semiquantitative analysis was done by SUV (Standardized Update Value). Confirmation of the findings was obtained in 44 cases (24 TR and 20 RN). MR was doubtful or inconclusive in most cases, whilst with PET correct diagnosis was made in all cases. CONCLUSIONS: Metabolic imaging with PET-FGD is better than anatomostructural imaging techniques for differential diagnosis between tumour relapse and radionecrosis in CNS tumours which have been treated. Prospective studies are necessary for evaluation of SUV as a factor for prognosis of survival.

Adult↗
PubMed1995

Urinary albumin excretion in Spanish children. Niño Jesus Group.

We measured urinary albumin excretion in 2,224 school-children (1,168 boys, 1,056 girls) aged 2-18 years, between 1989 and 1990 to establish reference values. We recorded all pathological antecedents and findings from physical examination, including anthropometric parameters and arterial blood pressure. The analytical study included serum total protein, albumin and creatinine. The second-morning urine and the nightly (rest) 10-h urine sample were collected and we determined the concentration of albumin and creatinine. We found a positive statistically significant correlation between the urinary albumin excretion (micrograms/10 h) and age, height, weight and body surface area. We suggest that it would be useful to relate the urinary albumin excretion to body surface area. The mean value for albumin excretion was 3.49 micrograms/ml in boys and 3.63 micrograms/ml in girls. The urinary albumin/creatinine ratio showed a high correlation with the albumin excretion (r = 0.958).

Adolescent↗
PubMed1984

Microcin 7: purification and properties.

Microcin 7 is an antibiotic peptide, produced and excreted to the culture medium by E. coli strains harboring the plasmid pRYC7. This peptide was extracted from the culture media by adsorbing it on octadecyl silica. It was purified by gel filtration on Sephadex G-25 and reverse phase high performance liquid chromatography. Its amino acid composition is the following: Ala (0.8), Arg (1.9), Asx (1.9), Gly (1.5), Met (0.8) and Thr (0.9). The purified peptide dose not react with ninhydrin and it is resistant to carboxypeptidase degradation, indicating that the molecule may be a cyclic or end-blocked oligopeptide.

Amino Acids↗
PubMed1984

Microcin-mediated interactions between Klebsiella pneumoniae and Escherichia coli strains.

Amensal indirect interactions between a Klebsiella pneumoniae microcin-producing strain and several Escherichia coli strains, all of intestinal origin, were studied. Mixed batch cultures of both microcin-producing and microcin-sensitive strains showed that microcin production and excretion into the medium allowed the producer strain to prevail over sensitive strains, even when initial competition conditions were highly unfavourable for the producer. Mixed cultures also showed the production of a microcin-antagonist by the same microcin-producing strain when the nutrients in the medium had been depleted. The antagonist apparently promoted the viability of sensitive cells already damaged by microcin. These results have likely ecological implications.

Anti-Bacterial Agents↗
PubMed1982

Microcin 15m from Escherichia coli: mechanism of antibiotic action.

It has been previously established that a high proportion of enterobacteria isolated from the intestinal content of humans, mostly Escherichia coli strains, secrete into the culture media antibiotic substances of low molecular weight, which have been called microcins. It was also found that the synthesis of these antibiotics is determined by plasmids. In this paper, a method for the purification of microcin 15m is described, and experimental data are given on the mechanism of its action. The data indicate that this action is based mainly on the inhibition of the first enzyme of the methionine biosynthetic pathway, homoserine-O-transsuccinylase, a similar way to the allosteric inhibition caused by this amino acid.

Acyltransferases↗