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G Moreno

Publications and source records attributed to G Moreno.

At least 19 recordsLinked to original sources
PubMed2002

Lambda(0) polarization in 800-GeV/cpp --> p(f)(Lambda0K+).

We report results from a study of Lambda(0) polarization in the exclusive reaction pp --> p(f)(Lambda0K+) at 800-GeV/c. We observe a dependence of the polarization on the Lambda0K+ invariant mass with large (+71%) positive polarization at small mass (1.63-GeV/c(2)) and large (-43%) negative polarization at large mass (2.75-GeV/c(2)). This observation confirms the result of the CERN ISR R608 experiment and extends the range over which the effect is observed. The strong dependence of the polarization on the Lambda0K+ invariant mass suggests that the origin of the polarization is closely related to the production dynamics of the diffractively produced Lambda0K+ system.

Journal Article↗
PubMed2001

Diffractively produced charm final states in 800-GeV/c pp collisions.

We report the first observation of diffractively produced open charm in 800-GeV/c pp collisions of the type pp-->pD*X. We measure cross sections of sigma(diff)(D*+) = (0.185+/-0.044+/-0.054) (mu)b and sigma(diff)(D(*-)) = (0.174+/-0.034+/-0.029) (mu)b. Our measurements are based on 4.3x10(9) events recorded by FNAL E690 in the fixed-target run of 1991. We compare our results with previous fixed-target charm experiments.

Journal Article↗
PubMed2001

The effects of singlet oxygen produced by photodynamic action on the mitochondrial permeability transition differ in accordance with the localization of the sensitizer.

We have examined whether the effects of singlet oxygen (1O2) produced by photodynamic action on the mitochondrial permeability transition (PT) can be modulated by the localization of photosensitizers in irradiated mitochondria. We have previously shown that oxidation due to 1O2 photogenerated in hematoporphyrin (HP)-loaded mitochondria can prevent opening of the PT pores, likely after degradation of some critical histidines (Salet et al, 1997, J. Biol. Chem. 272, 21938-21943). Equally, in the present study we have irradiated mitochondria in the presence of a structurally different photosensitizer producing 1O2, namely 4,5',8-trimethylpsoralen (TMP). Fluorescence studies show that TMP binds to protein sites which differ from those of HP. In sharp contrast with HP, TMP-driven photodynamic action triggers per se pore opening. Interestingly, this inducing effect is inhibited when TMP-treated mitochondria are irradiated after addition of mersalyl, a specific reagent protecting thiol groups of the inner mitochondrial membrane that are oriented toward the external hydrophilic phase. This fact suggests that 1O2-mediated thiol oxidation is responsible for TMP-photoinduced pore opening. Taken together, these findings suggest that 1O2 can activate or inactivate a cellular function such as mitochondrial PT depending on the site where it is produced in the mitochondrial membrane.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2001

Correlation of p53 oncoprotein expression with chemotherapy response in small cell lung carcinomas.

p53 oncoprotein expression was investigated in small cell lung carcinomas (SCLC) using immunohistochemical staining with antibodies against p53. A total of 50 pre-treatment biopsies were examined. We analyzed the relationship between p53 expression and these patients' relevant clinical characteristics, response to chemotherapy, time to progression, and overall survival. We found p53 overexpression in 46% of the samples but no association with clinical data or overall survival. Our results show a strong correlation of p53 staining with chemotherapy response. Multivariate analysis selected p53 as an independent predictive factor of chemotherapy response.

Aged↗
PubMed2001

Chlorogenic acids as a potential criterion in coffee genotype selections.

A systematic study by HPLC was conducted to determine the content of chlorogenic acids in green coffee beans of the Variedad Colombia (Coffea arabica Caturra var. x Híbrido de Timor) and in other genotypes of interest of C. arabica, Coffea canephora, Híbrido de Timor, and the F1 offspring derived from the crossing Caturra x Híbrido de Timor. Comparisons were made of the total content of these acids, their quantitative differences, and the presence or absence of some of them, using parametric statistical techniques and multivariate analysis. Total content differences were found between C. canephora accessions, between Típica and Caturra varieties of C. arabica, and between Híbrido de Timor accessions. The chromatographic profile comparisons with principal component analysis separated in the first component C. canephora accessions from the rest of the genotypes, whereas the second component separated C. canephora accessions.

Chlorogenic Acid↗
PubMed2001

Waldenström macroglobulinaemia: presenting features and outcome in a series with 217 cases.

In this report we analyse the presenting features of a series of patients diagnosed with Waldenström macroglobulinaemia (WM) in Spain over the last 10 years. Criteria for diagnosis required a serum monoclonal IgM protein > or = 30 g/l and > 20% bone marrow lymphocytes. Two hundred and seventeen patients were included in the study, with a median age of 69 years and male/female ratio of 2:1. The most common symptoms at diagnosis were anaemia (38%), hyperviscosity (31%), B symptoms (23%), bleeding (23%) and neurological symptoms (22%). Sixty-one patients (27%) were asymptomatic at diagnosis and, to date, 32 of them have not received chemotherapy. Variables predicting a shorter survival free of therapy were haemoglobin < 12.5 g/dl and high beta2microglobulin (beta2M). The 83% of patients who did receive treatment were distributed as follows: chlorambucil/prednisone (43%), intermittent chlorambucil (11%), continuous chlorambucil (26%), cyclophosphamide/vincristine/prednisone (COP, 13.5%) and other (6.5%). Response to therapy was complete in 2%, partial in 48% and minor in 10%. Finally, 28% and 13% of patients presented stable and progressive disease, respectively, which was more common among patients treated with COP. Progression-free survival was 43% at 5 years, with three independent predictors for shorter progression-free survival (PFS): COP treatment, age > 65 and B symptoms at diagnosis. The 10-year projected overall survival (OS) was 55%. The two most frequent causes of death were development of second malignancies (31%), or infections (19%). The two main variables predicting a poor OS were hyperviscosity and high beta2M. In summary, this study favours the use of chlorambucil-based therapy as the standard treatment for WM, and describes a subset of patients who should be considered as suffering a smouldering form and who therefore do not require treatment for a long period of time.

Aged↗
PubMed2001

Disaccharide modulation of the mitochondrial membrane fluidity changes induced by the membrane potential.

The influence of the medium composition on the dynamic properties of mitochondrial membranes on depolarization was studied by following the fluorescence anisotropy changes of mitochondria-bound 1,6-diphenyl-1,3,5-hexatriene (DPH) and hematoporphyrin (HP) as reporters, respectively, of lipid and protein regions. On collapse of the potential, the membrane fluidity increased in NaCl-, KCl-, and monosaccharide-based media and decreased in disaccharides. Infrared spectroscopy experiments suggested that disaccharides likely change water's structure and association on the membrane surface. These results indicate that disaccharides induce membrane perturbation, which may interfere in the study of structure-function correlation in biological membranes.

Animals↗
PubMed2001

Thiazide-sensitive cotransporter mRNA expression is not altered in three models of hypertension.

BACKGROUND/AIMS: Several lines of evidence support that the kidney is involved in the increase of arterial blood pressure, and some genetic studies suggest that the thiazide-sensitive Na+:Cl- cotransporter could be implicated in the development of hypertension. In the present study, we analyzed the Na+:Cl- cotransporter mRNA levels in the kidney during the development of hypertension in three experimental models. METHODS: The first model included 18 spontaneously hypertensive rats studied at 4, 10, and 16 weeks of age. The second model included 28 Wistar rats with two-kidney, one-clip Goldblatt hypertension studied at 7, 14, 21, and 28 days. The third model included 6 Wistar rats treated with N(G)-nitro-L-arginine methyl ester during 10 days. Respective controls were studied for all models. At the end of each experimental period, the systolic blood pressure was measured in the tail by plethysmography. Individual renal cortex total RNA was extracted, and the mRNA levels of the thiazide-sensitive Na+:Cl- cotransporter were assessed following a semiquantitative RT-PCR strategy. RESULTS: All experimental models developed systemic hypertension. However, the level of mRNA expression of the Na+:Cl- cotransporter did not change in any of the models studied as compared with their respective controls. CONCLUSION: Our results suggest that a change in mRNA levels of the thiazide-sensitive Na+:Cl- cotransporter is not associated with the development of hypertension in spontaneously hypertensive rats, in rats with renovascular hypertension, nor in rats with hypertension induced by nitric oxide synthesis inhibition.

Animals↗
PubMed2001

Beta-catenin expression pattern in small cell lung cancer: correlation with clinical and evolutive features.

Beta-catenin expression in small cell lung carcinomas (SCLC) was investigated by immunohistochemical method using antibodies against beta-catenin. 50 pre-treatment biopsies were examined and the relationship between beta-catenin expression and the patients' relevant clinical characteristics, response to chemotherapy, time to relapse or progression, and overall survival, were analyzed. Beta-catenin expression exhibited different intensity within each sample, predominantly localized in the cytoplasm, and no sample showed nuclear expression. There was cytoplasmic hyperexpression in 14 cases, hypoexpression in 15 cases, and normal expression in 21 cases. We did not find any association between beta-catenin expression and clinical data. Our results show, however, correlation between beta-catenin cytoplasmic hyperexpression with a shorter time to progression (p=0.0437) as well as with a shorter overall survival (p=0.0253). Beta-catenin hyperexpression could have prognostic significance in SCLC.

Aged↗
PubMed2000

Effects of the lipophilic biscation, bis-pyridinium oxime BP12, on bioenergetics and induction of permeability transition in isolated mitochondria.

In order to further investigate the mechanism of action of bridged lipophilic bis-pyridinium oximes previously observed to interfere with mitochondrial metabolism and to induce growth arrest and apoptosis in HeLa cells (Nocentini et al., Biochem Pharmacol 53: 1543-1552, 1997), we studied the effects of a bis-pyridinium oxime with a polymethylene chain N = 12 (BP12) on isolated rat liver mitochondria. Respiration in the absence of ADP with succinate plus rotenone as substrate was not affected after treatment with various concentrations of BP12 up to 10 microM, while the ADP-stimulated respiration was slowed down, with a parallel decrease in ATP synthesis. No effects of BP12 were detected on membrane potential, ATPase activity, and inorganic phosphate transport, but the adenine nucleotide translocase was inactivated and a permeability transition of the inner membrane was induced in the presence of calcium. These data suggest that mitochondrial impairment of ATP synthesis and the formation of the permeability transition pore may be responsible for apoptotic cell death already observed in cells treated with BP12.

Adenosine Triphosphate↗
PubMed2000

Radiocaesium and radiostrontium uptake by fruit bodies of Pleurotus eryngii via mycelium, soil and aerial absorption.

There has been an extraordinary increase in interest concerning the transfer of radioactive contamination to the fruit bodies of fungi since the Chernobyl nuclear power plant accident. These investigations, however, have focused exclusively on field studies aimed fundamentally at quantifying the behaviour of the radiocaesium component of the contamination. The results have shown great variability. As a contribution towards this body of knowledge, we have made a comparative study of the temporal evolution of the transfer of 85Sr and 134Cs via three routes of radioactive contamination--from the mycelium, from the surface layer of the soil, and directly onto the caps of the fruit bodies--for the saprophyte species, Pleurotus eryngii, under controlled laboratory conditions. The results indicate that the last of the above three uptake routes is the most efficient, and that the temporal evolution of the transfer is closely related to the radionuclide and the radioactive contamination route being considered.

Air Pollutants, Radioactive↗
PubMed1999

[Respiratory pasteurellosis. Description of a first series in Spain].

OBJECTIVE: To know the clinical and microbiological characteristics of a first series of 8 patients in whom Pasteurella multocida was detected in samples from low respiratory airways. PATIENTS AND METHODS: Patients with respiratory disease who had positive cultures for P. multocida in several biologic samples between 1986 and 1998 were studied. Patient's data were obtained from clinical files; microbiological study included microscopic examination, qualitative culture in all samples and quantitative culture in low respiratory airway samples. RESULTS: P. multocida was detected in 7 males and one female, with a mean age of 63 years (range: 6-71). All but one had a previous bronchial disease: 5 had chronic obstructive bronchial disease, 2 had bronchiectasis and one had relapsing acute bronchitis. Three patients referred a previous contact with pets. The main diagnosis, at the time P. multocida was detected, was exacerbated bronchitis in 4 patients, pneumonia in 2 (one with sepsis and positive blood culture to P. multocida) and another one with empyema. In the only paediatric patient P. multocida was a casual finding. Two patients died, both having a severe immunosuppression. The percentage of P. multocida detection compared to all low respiratory airway isolates along the study period was 0.02%. All samples were purulent and more than 10(7) P. multocida colony-forming units/millilitre were detected. All strains were penicillin-sensitive. CONCLUSIONS: Pasteurella multocida respiratory infection is rare, although it is probably underestimated owing to the fact that it is difficult to identify when coexisting with oropharingeal flora. Characteristically, in affects old males with bronchial disease are involved and can be life threatening in severely immunosuppressed patients.

Aged↗
PubMed1999

Changes of the fluidity of mitochondrial membranes induced by the permeability transition.

The dynamic properties of protein and lipid regions of mitochondrial membranes during the permeability transition (PT) process were studied by following the anisotropy changes of hematoporphyrin (HP) and 1,6-diphenyl-1,3,5-hexatriene (DPH), respectively. We show that opening of the PT pore is accompanied by a remarkable increase of mitochondrial membrane fluidity which is specifically localized to protein sites, while lipid domains are unaffected. The increased membrane fluidity is not related to the collapse of transmembrane potential that follows the PT, as demonstrated by a comparison between the anisotropy properties of permeabilized mitochondria and impermeable, depolarized organelles. Parameters such as osmotic swelling and temperature, which are shown to affect the mitochondrial membrane dynamics in the absence of permeability transition, cannot alone account for the pore dynamical properties. We suggest that the observed increase in fluidity is mainly due to a conformational change of pore-forming protein(s) during the "assembly" of the PT pore.

Animals↗
PubMed1999

Photodynamic action of porphyrin on Ca2+ influx in endoplasmic reticulum: a comparison with mitochondria.

We have studied the distribution properties of haematoporphyrin (HP) and protoporphyrin (PP) in mitochondria and endoplasmic reticulum after isolation from rat liver. The photosensitizing efficiency of porphyrin on the Ca2+ influx function of microsomes has been compared with that obtained on Ca2+ uptake in mitochondria. HP and PP are accumulated in microsomes to a greater extent than in mitochondria, both porphyrins binding to membrane protein sites. The Ca2+ influx functions of mitochondria and microsomes, before and after irradiation in the presence of HP or PP, were studied by following the changes in the free Ca2+ concentration in the medium as revealed by the variations in fluorescence intensity of the Ca2+ indicator Calcium Green-1. For the same amount of incorporated porphyrin, the Ca2+ influx function of microsomes is degraded by irradiation more rapidly than that of mitochondria. The protective effect of dithiothreitol suggests that thiol groups in the Ca2+-transporting enzyme are the preferential targets of the photodynamic effect. These results suggest that intracellular Ca2+ movements are altered primarily by the endoplasmic reticulum rather than by mitochondrial damage, in good agreement with other observations made in porphyrin-loaded irradiated cells.

Animals↗
PubMed1999

beta-catenin expression pattern in stage I and II ovarian carcinomas : relationship with beta-catenin gene mutations, clinicopathological features, and clinical outcome.

The immunohistochemical expression pattern of beta-catenin has been correlated with beta-catenin gene mutations, clinicopathological features, and disease outcome in 69 stage I and II ovarian carcinomas. beta-Catenin expression was localized in the nuclei, in addition to the cytoplasm and membrane, in 11 tumors (16%): nine endometrioid carcinomas with widespread nuclear expression and two serous carcinomas with focal nuclear expression. The remaining 58 carcinomas (84%) only had membranous beta-catenin expression. All but one of the endometrioid carcinomas with nuclear beta-catenin expression had considerable squamous metaplasia, and five of these cases had large areas of endometrioid tumor of low malignant potential. In addition, beta-catenin nuclear expression was observed in atypical epithelial cells in endometriotic glands adjacent to an endometrioid carcinoma. Sequencing was performed on 25 tumors and corresponding normal tissue: all 13 endometrioid tumors as well as 12 carcinomas of other histological types (four serous, two clear cell, two mucinous, and two mixed). There were oncogenic mutations in the phosphorylation sequence for GSK-3beta in exon 3 of the beta-catenin gene in seven endometrioid carcinomas with beta-catenin nuclear expression. Three mutations affected codon 32 (D32G, D32Y, and D32Y), one affected codon 33 (S33C), two affected codon 37 (S37C and S37F), and one affected codon 41 (T41A). No mutations were observed in the other 18 carcinomas analyzed, comprising two endometrioid and two serous carcinomas with beta-catenin nuclear expression, and 14 carcinomas of different histological types with only membranous expression. In the univariate and multivariate survival analyses, beta-catenin nuclear expression was selected as an indicator of good prognosis, because no patient whose tumor expressed beta-catenin in the nuclei showed relapses or died, in contrast to the 19 relapses and deaths among patients with tumors that only had beta-catenin membranous expression, including three of the four patients with endometrioid carcinomas. Oncogenic beta-catenin mutation is characteristic of a group of endometrioid carcinomas with a good prognosis, most of which originate from previous benign or borderline lesions. Endometrioid carcinomas with exclusively membranous expression of beta-catenin seem to represent a different subgroup of carcinomas that probably have a worse prognosis. In early-stage ovarian cancer, determination of the beta-catenin expression pattern could prove to be a useful marker for selecting low-risk patients.

Adult↗