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Biomedical subjects

B Delgado

Publications and source records attributed to B Delgado.

8 recordsLinked to original sources

Expression of D-type cyclins in colon cancer and in cell lines from colon carcinomas.

Cyclins D1, D2 and D3 play important roles in cell proliferation and differentiation. Although their abnormal expression has been linked to cancer development and progression in a number of tissues, the expression of cyclin D2 and D3 proteins in colon cancer has not yet been characterised. In this study, we examined cyclin D1, D2 and D3 protein expression by Western blot analysis in tumour and adjacent normal colon tissues of 57 patients. In addition, we examined D-type cyclins protein expression in HT29 and LoVo39 cell lines from colon carcinomas, as a function of induced proliferation and differentiation. In both cell lines, the expression of the three D-type cyclins increased as a result of induced proliferation, whereas the expression of cyclin D3 increased as a result of induced differentiation. In colon tumours, cyclin D1 was overexpressed in 44%, cyclin D2 was overexpressed in 53% and cyclin D3 was overexpressed in 35% of the cases. We also found that in 16% of the cases, cyclin D3 protein expression was reduced in the tumour, as compared to the adjacent normal tissue. Examination of D-type cyclin protein overexpression in relation to the TNM stage of the tumours revealed that overexpression of cyclins D1 and/or D2, but not cyclin D3, is linked to colon carcinogenesis and that overexpression of cyclin D2 may be related to a higher TNM stage of the tumour.

Aged↗

The effect of pH on the covalent and metabolic control of C4 phosphoenolpyruvate carboxylase from Sorghum leaf.

The influence of pH on the in vitro activity and regulatory properties of Sorghum leaf C4 phosphoenolpyruvate carboxylase (PEPC) was investigated with respect to the phosphorylation status of the enzyme. In vitro protein phosphorylation was achieved using the catalytic subunit of a cAMP-dependent protein kinase (PKA) and a recombinant, immunopurified PEPC (0.9 mol of covalent Pi/mol PEPC subunit). Between pH 6.8 and 8, velocity and IC50 for L-malate increased for both the nonphosphorylated and the phosphorylated forms. With respect to the nonphosphorylated PEPC, the phospho-PEPC always gave high values for these kinetic parameters at the pH range investigated, especially between pH 7 and 7.3. The phosphorylation-induced stimulation of PEPC activity was four- to fivefold at pH 7.1 and approximately twofold at pH 7.3. The IC50 for L-malate showed a two- to threefold increase at pH 7.3, but varied less at pH 7.1 upon PEPC phosphorylation. Thus, phosphorylation of PEPC caused a predominant V effect or a mixed (V/IC50) effect at pH 7.1 or 7.3, respectively. This was also observed with the enzyme from desalted crude protein extracts from dark or light-adapted Sorghum leaves and leaf-derived mesophyll protoplasts illuminated in the presence of methylamine, a compound known to increase cytosolic pH (pHc). At pH 7.3, desensitization to L-malate of phospho-PEPC was due to an enhanced ability of PEP to compete with the inhibitor. The positive effector glucose-6P acted similarly to phosphorylation; however, a combination of both factors (glucose-6P and phosphorylation) led to a much larger increase in the IC50 for L-malate than that observed by a single factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucosephosphates↗

Nitrate-dependent o(2) evolution in intact leaves.

Evolution of O(2) by illuminated intact detached leaves from barley (Hordeum vulgare L. cv Athos) and pea (Pisum sativum L. cv Lincoln) in a CO(2)-saturating atmosphere was enhanced when KNO(3) (1-2.5 millimolar) had been previously supplied through the transpiration stream. The extra O(2) evolution observed after feeding KNO(3) increased with the light intensity, being maximal at near saturating photon flux densities and resulting in no changes in the initial slope of the O(2)versus light-intensity curve. No stimulation of O(2) evolution was otherwise observed after feeding KCl or NH(4)Cl. The data indicate that nitrate assimilation uses photosynthetically generated reductant and stimulates the rate of non-cyclic electron flow by acting as a second electron-accepting assimilatory process in addition to CO(2) fixation.

Journal Article↗

Nodular fasciitis initially diagnosed by aspiration cytology.

A case of nodular fasciitis diagnosed by fine needle aspiration cytology is described. The cytologic findings included fusiform cells, mitoses, macrophages, multinucleated giant cells and mesenchymal elements in a characteristic granular background substance. The cytopathologic diagnosis was subsequently confirmed by the histopathologic study of the tumor and by electron microscopy.

Adult↗

[Treatment with Savary-Gilliard bougies in esophageal stenosis in children].

30 patients (less than 15 years old) were admitted for esophageal strictures, 16 of them secondary to corrosive injury. All the patients were treated with endoscopic dilatation with Savary-Gilliard bougie. The dilations were done with general anesthesia using an Olympus GIF-XP10 endoscope and with fluoroscopic control. In the esophageal stenosis secondary to caustic ingestion endoscopic injection with Betamethasone was also used. The most frequent site of the stenosis was the upper third of the esophagus, and the main type of stenosis was tubular in the secondary to caustic burns and annular in the other group. In the post-caustic group 385 dilations were performed in 115 sessions. In the other group 159 dilations were done in 51 sessions. Two perforations and one sepsis were reported in patients with corrosive stenosis. There was no mortality. 43.7% of the patients with corrosive stenosis and 85.7% with stenosis secondary to other causes obtained complete healing. Esophageal dilation with Savary-Gilliard bougies represents a safe and reliable method for the treatment of esophageal strictures.

Adolescent↗