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F Miralles

Publications and source records attributed to F Miralles.

At least 55 records · Page 3Linked to original sources
PubMed1994

Characterization of the proximal estrogen-responsive element of human cathepsin D gene.

Cathepsin D, a lysosomal proteinase, is induced by estrogens in mammary cancer cells where its concentration is correlated with a higher risk of metastasis. Its gene expression is stimulated by estrogens in MCF7 cells, and we have shown that a short proximal promoter fragment from -365 to -122 is required for this induction. We now characterize, at -261, a nonconsensus estrogen-responsive element (ERE) (E2) with two differences in the distal half of its palindrome, which confers estradiol responsiveness to the heterologous Herpes simplex virus thymidine kinase promoter in transient transfection experiments. This ERE is located in a 21-base pair sequence: 5'GGGCCGGGCTGACCCCGC GGG3', containing a GC-rich region in its 3'-part, which is almost perfectly repeated at -362 (the E1 site). The E2 site was necessary but not sufficient to mediate an estrogen response and required cooperation with the homologous E1 element and/or with general transcription sites located downstream. In vitro, the E2 site but not the E1 site was protected by estrogen receptor (ER) against DNAse I digestion, and gel shift experiments suggested an interaction with the ER as a dimer. Moreover, we showed in vivo that ER DNA binding domain was required to mediate estrogen induction from the cathepsin D ERE. We conclude that estradiol induction of cathepsin D is mediated by interaction of the ER with a nonconsensus ERE that requires synergy with other elements located upstream and/or downstream of this central ERE.

Base Sequence↗
PubMed1993

Human fetoacinar pancreatic protein: an oncofetal glycoform of the normally secreted pancreatic bile-salt-dependent lipase.

A fetoacinar pancreatic protein (FAP) associated with the ontogenesis, differentiation and oncogenic transformation of the human exocrine pancreas has been purified from pancreatic juices of patients suffering from pancreatitis or duodenal cancers invading the pancreas [Escribano and Imperial (1989) J. Biol. Chem. 264, 21865-21871]. This protein has striking similarities, i.e. M(r), amino acid composition and N-terminal sequence, to the bile-salt-dependent lipase (BSDL) of normal human pancreatic secretion. The aim of this study was to gain further insight into the nature of the two proteins. Reactivity with the mouse monoclonal antibody J28 (mAb J28), which characterizes FAP, and enzyme activity could not be dissociated during biochemical purification of BSDL. Furthermore, a polyclonal antiserum raised against purified human BSDL reacted completely with FAP in Western-blot analysis giving additional support to the idea of similar molecular structures for BSDL and FAP. However, by the same technique, mAb J28 reacted with a relatively restricted population of BSDL molecules. The classical BSDL preparation could be separated into molecules bearing the J28 epitope and those devoid of it by immunoaffinity on immobilized mAb J28. The two subpopulations had identical N-terminal sequences and some differences in their amino acid compositions. However, they had different carbohydrate compositions. J28-epitope-bearing molecules were active on BSDL substrates, although their specific activity was decreased. These results are consistent with the existence of two closely related polypeptide chains with different glycan counterparts. Therefore, if the name FAP is reserved for molecules bearing the J28 epitope, which is linked to a carbohydrate-dependent structure. FAP could represent an oncofetal-related variant of BSDL. Our result is the first demonstration of the existence of an oncofetal-type subpopulation of an otherwise normally secreted human pancreatic enzyme.

Amino Acid Sequence↗
PubMed1993

Effects of coumarin derivatives on superoxide anion generation.

A number of simple coumarins with different patterns of substitution were tested on activated polymorphonuclear leukocyte superoxide generation and superoxide scavenging using the reduction of nitroblue tetrazolium. The most effective compound was fraxetin, which showed a better potency as an inhibitor of superoxide radical generation than as a scavenger. From the structure-activity study it can be deduced the importance of an ortho-dihydroxyl function, especially at the position 7, 8. Blockade of active hydroxyl groups by methylation or glycosylation decreases the activity. None of the coumarins were cytotoxic on leukocytes as assessed by lactic dehydrogenase activity release. Inhibition of superoxide generation in activated neutrophils may play a role in the vasoprotective effects of simple coumarins.

Animals↗
PubMed1993

Retention of the fetoacinar pancreatic (FAP) protein to the endoplasmic reticulum of tumor cells.

The fetoacinar pancreatic (FAP) protein is a specific component of the human exocrine pancreas associated with the differentiation and proliferation of acinar cells. FAP expression is enhanced in cases of pancreatic exocrine cancer and it is found in relatively high concentrations in pathological pancreatic juices. However, tumor cell lines do not secrete FAP into the culture medium. In this paper we analyze the intracellular localization of FAP in cell lines and compare some biological properties of the tumoral FAP with the normal adult and fetal forms. Immunocytological experiments performed using Mab J28 which characterizes FAP, gave a staining pattern suggestive of FAP localization in the ER. Subcellular fractionation corroborated this localization and established that FAP is tightly associated with the microsomal membranes. The absence of reactivity of the tumoral FAP with wheat germ agglutinin lectin and its strong reactivity with concanavalin A is consistent with the idea that FAP in tumor cells does not reach the Golgi apparatus and it is consequently retained in the endoplasmic reticulum (ER). FAP contained in hepatic metastasis derived from pancreatic adenocarcinoma appeared to be similar, if not identical, to that expressed by cell lines. This supports the hypothesis that FAP retention in the ER of malignant cells is a physiological phenomenon and not the result of a modification of cell lines due to the culture conditions. FAP expressed by cancer cell lines and metastases appeared by sodium dodecyl sulfate polyacrylamide gel electrophoresis a homogeneous protein with a M(r) of 120,000. Instead, the secreted mature protein consists of a main component of M(r) 110,000 and shows pronounced polymorphism (dispersion from M(r) 110,000 to 80,000). Increased size of the ER-retained protein is likely due to elongation of the peptide chain. Defective processing in the ER as a result of amino acid mutation could therefore explain the behavior of this protein in tumors.

Adenocarcinoma↗
PubMed1992

Radioimmunolocalization of the monoclonal antibody J28 in early transformation stages in N-nitrosobis(2-hydroxypropyl)amine-induced pancreatic tumors in the Syrian golden hamster.

We describe the in vivo localization of radiolabeled mAb J28, a murine monoclonal antibody characterizing the oncodevelopmental human fetoacinar pancreatic (FAP) protein, at different stages of chemical induction of pancreatic tumors in the Syrian golden hamster. Before doing localization studies in this model, we looked at the cross-reactivity of mAb J28. Semiquantitative dot-blot analysis demonstrated that the antigen recognized in hamster pancreas has an oncodevelopmental expression pattern, while a molecular mass identical to that of human FAP was deduced from sodium dodecyl sulfate/polyacrylamide gel electrophoresis/nitrocellulose immunoblot. 125I-labeled mAb J28 was administered through micro-osmotic pumps to hamsters treated with N-nitrosobis(2-hydroxypropyl)amine (BHP). This was done at three intervals that roughly correspond to the latent period, pretumoral stages, and terminal cancerogenesis in two independent groups of hamsters. Both studies allowed similar results: (a) mAb J28 accumulated almost specifically in the pancreas; (b) maximal accumulation was associated with pleomorphic alterations of the acinar cell tissue at pretumoral stages; (c) no accumulation was found in the case of adenocarcinoma of the pancreas. It is concluded that FAP behaves as a marker of preneoplastic lesions, and therefore that radioimmunoimaging with mAb J28 might help with early diagnosis of pancreatic cancer.

Animals↗
PubMed1992

[Primary intraventricular hemorrhage in a patient with unilateral moyamoya disease].

According to the diagnostic criteria currently in use, the so-called "unilateral" forms of the moyamoya disease, or rather those in which the disorders of the disease itself--such as occlusion of the internal supraclinoid carotid artery or its terminal branches and development of abnormal collateral circulation in the region of the basal ganglia--are only found in one hemisphere and should be considered as "probable" forms of the disease with a much lower incidence than the bilateral or "defined" forms of the same. One patient with a primary intraventricular hemorrhage (PIVH) in whom an occlusion of the right internal carotid artery was angiographically demonstrated and in whom collateral type moyamoya circulation was found as was the presence of an aneurysm in the right coroid territory is presented. The association of PIVH, unilateral moyamoya disease and aneurysm is infrequent in the literature, with the origin of the bleeding, in some cases, having been attributed to rupture of the aneurysm. Since angiographic control was not available in the patient presented it cannot be excluded that the aneurysm was really a pseudoaneurysm therefore being a consequence, rather than a cause, of the arterial rupture. Thus one of the other mechanisms proposed must be invoked to explain the pathogenesis of the PIVH: rupture of a perforating artery or of a microaneurysm located in the subependimary periventricular region. The treatment recommended for these case of PIVH associated to aneurysm is chirurgical if persistence is demonstrated in successive arteriographies.

Adult↗
PubMed1991

Comparison of carbohydrate and peptide biotinylation on the immunological activity of IgG1 murine monoclonal antibodies.

When the classical amino acid esterification procedure was used for the biotinylation of the IgG1 monoclonal antibody J28 it resulted in a loss of immunological activity. This antibody recognizes the fetoacinar pancreatic (FAP) antigen and the decrease in reactivity was directly proportional to the molar biotin/antibody ratio indicating substitutions at or near the antibody combining site. This effect was specific to J28 since the IgG1 Mab F22 which recognises the same antigen was not damaged by this procedure. Active Mab J28 conjugates were obtained using biotinylation via oligosaccharide moieties. The biotinylation efficiency using this method was dependent on the previous degree of antibody periodate oxidation and the maximal substitution was 3 mol biotin per mol of antibody. Using these conditions the sensitivity of the biotinylated J28 for the FAP antigen was similar to that obtained when using non-substituted antibody in the two antibodies technique.

Animals↗
PubMed1990

A scanning calorimetric study of natural DNA and antitumoral anthracycline antibiotic-DNA complexes.

Thermal denaturation of natural DNA in the absence and presence of antitumor anthracycline antibiotics has been studied by adiabatic differential scanning calorimetry. The helix-coil transition is operationally irreversible as measured by DSC. Both the melting temperature and the overall molar transition enthalpy of the DNA samples was dependent on the percentage of GC base pairs. Calorimetric traces of anthracycline-DNA complexes have qualitatively similar features and the significance of this characteristic is discussed. The unsaturated drug-DNA complex melts through complex thermal transitions with one broad endotherm in the same temperature region as free DNA and the other at a higher temperature which is rf (mol ligand per mol DNA in base pairs) value dependent. Antibiotic binding at concentrations close to saturating conditions (rf = 0.2) reverts the melting range to a value near to its original one and increases the thermal stability of the duplex structure by around 30 degrees C. In addition, the calorimetric enthalpy is increased by between 64% and 150%, depending on which ligand was used.

Animals↗
PubMed1990

Epidermal growth factor receptor in human breast cancer: correlation with cytosolic and nuclear ER receptors and with biological and histological tumor characteristics.

Epidermal growth factor receptor (EGFr) and cytosolic (cER) and nuclear (nER) estradiol receptors were quantified in 220 primary breast cancers. The EGFr was significantly more frequent (chi 2 = 5.9; P less than 0.025) and its concentration was significantly higher (P less than 0.001) among ER- tumors than in ER+ tumors. There was a significantly greater proportion (chi 2 = 6.4; P less than 0.05) of node involvement in EGFr+/ER+ tumors than in EFGr-/ER+. Increases in the proportion of EGFr+ in ER- tumors are parallel to Scarff-Bloom scores (chi 2 = 6.1; P less than 0.05) and there is a significant trend (Spearman rs = 0.25; P less than 0.05) towards increased EGFr concentrations with histologic dedifferentiation. In ER+ tumors the median concentrations of EGFr in the different age groups show a linear correlation (LCC = 0.89; P less than 0.05) and follow a parallel profile with the medians of nER. These findings support the hypothesis that EGFr is a bad prognosis factor and suggest that EGFr expression and concentration in ER+ tumors might be considered an estrogenic action mediated through the binding of ER to their nuclear acceptors.

Adult↗
PubMed1989

[Determination of free erythrocyte protoporphyrin in thalassemic trait].

Free erythrocyte protoporphirin (FEP), along with diverse haematologic and iron metabolism data, were determined in 60 carriers of the thalassaemic trait (29 beta and 31 delta beta). FEP rates were significantly higher in thalassaemia carriers (39.04 +/- 14.12 micrograms/dl) than in a control group (24.95 +/- 4.70 micrograms/dl) (p less than 0.05). No correlation between FEP and any other iron metabolism parameter, or the severity of anaemia, was found. No FEP differences appeared between the beta (41.06 +/- 16.5 micrograms/dl) and delta beta (37.1 +/- 11.06 micrograms/dl) traits, so, although FEP rates are increased in thalassaemia carriers, they are useless in differentiating between the commonest thalassaemic forms in our country.

Adolescent↗
PubMed1989

[Evaluation of erythrocyte deformability in carriers of thalassemic trait with the Hanss' hemorheometer].

Red-cell deformability was assessed with the Hanss' haemorheometer in 63 carriers of the thalassaemic trait (20 beta and 43 delta beta). Impaired deformability (rigidity index 10.5 +/- 1.4) was present in 80% of the carriers of both beta- and delta beta-traits, as compared with a control group (rigidity index 8.7 +/- 0.6). No correlation was found between such indices and several parameters capable of influencing upon red-cell deformability, namely, MCV, MCH, RDW and MDA. The possibility of any impairment of lipid compounds in red cell membrane is suggested as a cause of decreased deformability in thalassaemia carriers.

Adolescent↗
PubMed1986

Naloxone prevents hyperthermia induced convulsions in the immature rat.

There is increasing evidence suggesting that endogenous opioid peptides play a role both in temperature regulation and in the etiopathology of seizures. We have studied the effects of the opioid antagonist naloxone on hyperthermia-induced seizures in unrestrained 15 day old rat pups. Saline injected control animals exposed to an ambient temperature of 40 degrees C for one hr showed a gradual increase in body temperature reaching a maximum of 42 degrees C at 50 min of exposure; at this time, all animals had convulsions and 86% died. Animals pre-treated with 10 mg/kg naloxone reached a maximum core temperature of 41 degrees C after 60 min at 40 degrees C and no convulsions or deaths were observed. When animals were exposed for 60 min to a 27 degrees C environment, saline controls maintained their normal body temperature throughout the experiment, while 5 mg/kg naloxone produced a marked hyperthermic effect. These experiments suggest that endogenous opioids may play a role in both temperature adaptation and hyperthermia-induced seizures in the rat pup.

Adaptation, Physiological↗
PubMed1984

Effects of stress and stress-therapy on plasma beta-endorphin-like immunoreactivity.

Beta-Endorphin-like immunoreactivity (B-ELI) was determined in the plasma of ten patients in presurgical stress conditions and after administration of dehydrobenzperidol (DHB, n = 3) and DHB plus fentanyl (Innovar, n = 7). Human B-ELI was determined by radioimmunoassay. The B-ELI was extracted from plasma with ODS-silica columns. B-ELI plasma levels increased significantly (P less than 0.02) during stress (7,7 +/- 1.2 fmol/ml and 23.3 +/- 4.1 fmol/ml for the control and stress, respectively). After administration of DHB plus fentanyl, a significant decrease (p less than 0.05) of B-ELI plasma levels was observed as compared with the presurgical stress conditions (10.1 +/- 0.8 fmol/ml and 21.1 +/- 5.2 fmol/ml, respectively), whereas no significant difference was observed (p greater than 0.05) in B-ELI plasma levels obtained in the DHB group compared with presurgical stress conditions (10.4 +/- 5.0 fmol/ml, and 28.3 +/- 7.1 fmol/ml, respectively). These results suggest a direct correlation between the emotional stressful situation of presurgery and increase in B-ELI plasma levels. The findings obtained with administration of DHB plus fentanyl seem to lend support to the hypothesis that this premedication is a good stress therapy.

Adolescent↗
PubMed1982

[Measurement of endorphins in human cerebrospinal fluid. Comparative study of various groups of patients].

Endorphin levels in human cerebrospinal fluid (CSF) have been determined by using the electrically stimulated mouse vas deferens bioassay. Endorphins were extracted by adsorption to a synthetic resin of Amberlite XAD-2 eluted with methanol, and dried under a nitrogen atmosphere. Three different groups of patients have been studied: a) control subjects without a history of pain (n = 25), b) patients with acute postoperative pain after high abdominal and thoracic surgery (n = 8) and c) patients with chronic pain due to discal hernia (n = 14). The endorphin levels (expressed as equivalents of Met-E) obtained from the control group were 4.36 +/- 0.7 pmol/ml. In the postoperative group an endorphin decrease of 0.42 +/- 0.07 pmol/ml, was found while in the chronic pain group the levels obtained were 1.39 +/- 0.2 pml/ml. Thus a significantly low level of CSF endorphins was observed in both the postoperative and the chronic pain group as compared with the controls (p less than 0.01). These results suggest a correlation between pain levels and endorphin concentration in CSF. However in the acute postoperative pain group other factors such as depletion of endorphins by drugs used for anesthesia or due to surgical stress cannot be excluded.

Adult↗