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Showing papers by "University of Barcelona published in 1982"



Journal ArticleDOI
TL;DR: Investigation of the effect of nitroglycerin on splanchnic and systemic hemodynamics in cirrhotic patients and portal hypertensive dogs and in dogs provides evidence that the addition of nitreglycerin to an i.v. infusion of vasopressin reversed the detrimental effects of vasipressin while preserving the beneficial effects.

221 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the problem of eliminating the momentum variable in the phase space Langevin equations for a system of Brownian particles in two related situations: (i) position-dependent damping and (ii) existence of hydrodynamic interactions.
Abstract: We discuss the problem of eliminating the momentum variable in the phase space Langevin equations for a system of Brownian particles in two related situations: (i) position-dependent damping and (ii) existence of hydrodynamic interactions. We discuss the problems associated with the conventional elimination and we develop an alternative elimination procedure, in the Lagevin framework, which leads to the correct Smoluchowski equation. We give a heuristic argument on the basis of stochastic differential equations for the Smoluchowski limit and establish rigorously the limit for the general case of position-dependent friction and diffusion coefficents.

185 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the structure functions S(k, t) obtained from computer simulations of the time evolution of a segregating binary alloy following quenching into the miscibility gap.

177 citations



Journal ArticleDOI
01 Dec 1982-Blood
TL;DR: The prognostic value of different clinical and laboratory findings at diagnosis of chronic myeloid leukemia (CML) was analyzed in a series of 121 cytogenetically studied patients and the difference in survival of the patients at different stages was highly significant.

104 citations


Journal ArticleDOI
TL;DR: In this paper, a fairly complete study of the renormalization of FaμνFμνa is presented in the gauge in which it is simplest: the background field gauge, allowing one to go to second-order perturbation theory without evaluating a single Feynman integral.

93 citations


Journal ArticleDOI
01 May 1982-Blood
TL;DR: A marked prognostic value of the degree of absolute peripheral lymphocytosis emerged in the whole population as well as in low and intermediate risk groups of patients, pointing out that different subsets of patients can be isolated within these groups.

92 citations


Journal ArticleDOI
TL;DR: Hyperacetylation of H4 and rapid turnover of its acetyl groups could be correlated with the particular conformation of chromatin in elongated spermatids and might represent a necessary condition for binding of chromosomal proteins to DNA.
Abstract: In order to study the relationship between acetylation of histones, chromatin structure and gene activity, the distribution and turnover of acetyl groups among nucleosomal core histones and the extent of histone H4 acetylation were examined in rooster testis cell nuclei at different stages of spermatogenesis. Histone H4 was the predominant acetylated histone in mature testes. Hyperacetylation of H4 and rapid turnover of its acetyl groups are not univocally correlated with transcriptional activity since they were detected in both genetically active testicular cells and genetically inactive elongated spermatids. During the transition from nucleohistone to nucleoprotamine in elongated spermatids the chromatin undergoes dramatic structural changes with exposition of binding sites on DNA (1). Hyperacetylation of H4 and rapid turnover of its acetyl groups could be correlated with the particular conformation of chromatin in elongated spermatids and might represent a necessary condition for binding of chromosomal proteins to DNA.

91 citations


Journal ArticleDOI
01 Feb 1982-Blood
TL;DR: The molecular characteristics of G6PD in the patient differed from those of all previously reported variants associated with CNSHA, so the present variant was provisionally called G 6PD Barcelona to distinguish it from other G6 PD variants previously described.

70 citations


Journal ArticleDOI
TL;DR: In this paper, the renormalization of the three pseudoscalar gauge invariant operators which appear in the Adler-Bell-Jackiw anomaly is studied in the back ground field gauge, where it is simplest.
Abstract: The renormalization of the three pseudoscalar gauge invariant operators which appear in the Adler-Bell-Jackiw anomaly is studied in the back-ground field gauge, where it is simplest. We analyse questions concerning renormalization-group invariance, mixing, the γ5-perscription inD dimensions, as well as the meaning of the nonrenormalization of the axial anomaly in the context of the renormalization of composite operators.

Journal ArticleDOI
TL;DR: The 5′‐nucleotidase located in the cytoplasmic fraction of bovine brain cortex was purified to electrophoretic homogeneity, and the variation of Vm and Km with a change in pH suggests the existence of a sulfhydryl group and an imidazole group in the enzymesubstrate complex.
Abstract: The 5'-nucleotidase located in the cytoplasmic fraction of bovine brain cortex was purified to electrophoretic homogeneity. The molecular weight was 134,000 daltons in the presence of sodium deoxycholate, whereas the enzyme formed high molecular weight aggregates in the absence of detergent. The purified enzyme showed the same kinetic and electrophoretic behaviour as the enzyme present in the original cytoplasmic fraction, and the presence of surfactants did not change the Km and Vm values. The nucleotidase from this source was a phosphohydrolase of 5'-mononucleotides acting on the deoxyribonucleotides and ribonucleotides of purines and pyrimidines. 5'-IMP was the preferred substrate; the optimum pH was 7.5. The study of the influence of the temperature on the initial reaction rates allowed calculation of the delta Ea and delta H degrees values. The variation of Vm and Km with a change in pH suggests the existence of a sulfhydryl group and an imidazole group in the enzyme-substrate complex.

Journal ArticleDOI
TL;DR: The homogeneous preparations of the three isozymes show intrinsic glycerate-2,3-P2 synthase activity and glyceric phosphatase activity which can be stimulated by glycolate- 2-P and the kinetic pattern is consistent with a 'ping-pong' mechanism.

Journal ArticleDOI
01 Nov 1982-Cancer
TL;DR: The combination of AFP or B2M with CEA, AGP or PHI did not improve the discriminative value for differentiating malignant and benign effusions, and CEA level estimations were useful for confirming malignancy but not for excluding it.
Abstract: In order to discriminate between benign and malignant effusions, the value of carcinoembryonic antigen (CEA), alpha 1-acidglycoprotein (AGP), alpha-fetoprotein (AFP), phosphohexose isomerase (PHI), and beta 2-microglobulin (B2M) has been estimated in serous effusions in a group of 106 patients, 30 with a malignant and 76 with a benign effusion. Mean CEA and AGP levels in malignant effusions were significantly higher than in benign effusions; no significant differences of mean PHI, AFP and B2M levels of benign and malignant effusions were found. CEA level estimations were useful for confirming malignancy in 27% of malignant effusions but in only 7.5% of all effusions, and AGP and PHI for excluding it in 37.5 and 36.0% of all effusions, respectively. With the combination of CEA with AGP or PHI, a correct diagnosis was achieved in only 45 and 44% of all effusions, respectively. The combination of AFP or B2M with CEA, AGP or PHI did not improve the discriminative value for differentiating malignant and benign effusions.

Journal ArticleDOI
TL;DR: The violaceous plaques or tumours infiltrated by lymphoplasmocytoid cells, and the pink, translucent, shiny papules composed of deposits of hyaline monoclonal IgM possess definite clinico‐pathological characteristics that may permit the diagnosis of Waldenström's macroglobulinaemia before any other data are available.
Abstract: Patients affected by Waldenstrom's macroglobulinaemia may rarely present specific cutaneous manifestations. The violaceous plaques or tumours infiltrated by lymphoplasmocytoid cells, and the pink, translucent, shiny papules composed of deposits of hyaline monoclonal IgM possess definite clinico-pathological characteristics that may permit the diagnosis before any other data were available. The immunopathological and ultrastructural features of these lesions are described.

Journal ArticleDOI
TL;DR: Carson (1965) has explained the low levels of chromosomal polymorphism found in colonizing populations of some species of Drosophila in terms of his theory of homoselection in marginal environments.
Abstract: The correlations often found between chromosomal polymorphism distribution and ecogeographical conditions have interested many earlier workers in microevolution (Carson, 1958; Da Cunha et al., 1959; Carson and Heed, 1964; Sperlich, 1964). It is widely recognized that, at least in Drosophila, central populations are more polymorphic for inversions than marginal populations, although the adaptive causes of this differentiation (Dobzhansky, 1951; Carson, 1959) are still subjected to debate. Most species arise in a single geographic region from which they may colonize new areas. Colonization stirred the attention of biologists at a symposium (Baker and Stebbins, 1965) in 1964, but since then very little experimental work (Martins and Jain, 1979) has been done to study the genetic structure of colonizing species. A few historically documented cases of colonizations may illustrate the types of genetic changes which generate the present inversion polymorphism distributions of these colonizing species and thus lead to a better understanding of their adaptive strategies. Drosophila buzzatii, a South American species which colonized the Old World in historical times, is one of these cases. Carson (1965) has explained the low levels of chromosomal polymorphism found in colonizing populations of some species of Drosophila in terms of his theory of homoselection in marginal environments

Journal ArticleDOI
TL;DR: In this paper, the use of the NBB-resin for synthesis of protected segments followed by solid phase segment condenstaion was discussed, where two protected segments were purified on Sephaex LH-20 followed by Bio-Beads S-X1 chromatography and respectively coupled onto a resin on which the 7-18 sequence of apamin was assembled stepwise with the standard solid phase procedure.

Journal ArticleDOI
TL;DR: In this paper, a one-pot synthesis of methyl and ethyl esters from aldehydes, using aromatic nitrocompounds as oxidizing agents under the catalytic action of a cyanide ion or of a conjugate base of a thiazolium ion, is described.

Journal ArticleDOI
TL;DR: In this paper, a convergent solid phase peptide synthesis has been applied to yield LHRH, which was synthesized on a hydroxymethylphenyloxymethyloxideymethyl resin using the base labile Fmoc protecting group on the α-amines.

Journal ArticleDOI
TL;DR: In this paper, the mass and width of the lowest lying scalar glueball with the help of the ITEP sum rules were studied, and it was shown that the standard value of the gluon condensate leads to very broad structures, which one could hardly call a resonance.

Journal ArticleDOI
TL;DR: In this article, various surface water systems in the metropolitan area of Barcelona (Spain), including two rivers and three beaches, were analysed for human viruses using glass powder as adsorbent to concentrate them.

Journal ArticleDOI
TL;DR: In this paper, an evolution law for the polarization plane of an electromagnetic wave due to a gravitational field was derived in the geometric optics approximation for the particular case of a Kerr space-time, and the results were compared with others which have already appeared in the literature.
Abstract: We study the rotation of the polarization plane of an electromagnetic wave due to a gravitational field. An evolution law for the polarization plane is derived in the geometric optics approximation. For the particular case of a Kerr space-time, we obtain the polarization plane rotation for an incident light ray parallel to the Z axis at z = -∞ and for a radially outgoing one. The results are compared with others which have already appeared in the literature.

Journal ArticleDOI
TL;DR: In this paper, the authors considered a system under the influence of an external gaussian noise with a flat spectrum and finite cut-off frequency and studied the stationery properties of the system as a function of the correlation time of the noise.
Abstract: We consider a system under the influence of an external gaussian noise with a flat spectrum and finite cut-off frequency. The stationery properties of the system are studied as a function of the correlation time of the noise. Theoretical predictions based on an expansion in powers of the correlation time are corroborated by experimental measurements on an electric circuit with a digital noise generator. The two main qualitative properties experimentally observed which can not be explained in a white noise limit theory are: (i) appearance of relative extrema of the stationery distribution for high noise intensity when the correlation time is not too small; (ii) dependence on the noise characteristics of the position of the maximum of the stationary distribution for low noise intensity.

Journal ArticleDOI
TL;DR: The distribution of the glycerate-2,3-P2 dependent and independent phosphoglycerate mutases (PGM) has been studied in more than eighty species and both types of PGM are present in animals and algae and fungi.
Abstract: 1. 1. The distribution of the glycerate-2,3-P2 dependent and independent phosphoglycerate mutases (PGM) has been studied in more than eighty species. 2. 2. PGM activity in the extracts has been measured in the presence and in the absence of glycerate-2,3-P2, at pH 7.5 and at pH 8.5. 3. 3. All samples with glycerate-2,3-P2 dependent PGM possess higher activity at pH 7.5 than at pH 8.5. In contrast, samples with glycerate-2,3-P2 independent PGM possess lower activity at pH 7.5 than at pH 8.5. 4. 4. In algae and fungi both glycerate-2,3-P2 dependent and independent PGM have been found. 5. 5. In plants only glycerate-2,3-P2 independent PGM has been detected. 6. 6. In animals both types of PGM are present. Independent PGM activity is present in sponges, coelenterates, myriapods, arachnids and echinoderms. Glycerate-2,3-P2 dependent PGM is present in platyhelminths, mollusks, annelids, crustaceans, insects and vertebrates.

Journal ArticleDOI
TL;DR: In this paper, the Callan-Symanzik γ-function is studied in the large number of lepton (in QED) or flavour (in qCD) limit.
Abstract: The Callan-Symanzik γ-function is studied in the large number of lepton (in QED) or flavour (in QCD) limit. We have computed analytically 7 terms and they show a striking factorization. We have computed numerically 19 terms and they show a large radius of convergence and two unambiguous zeros within the region of convergence.

Journal ArticleDOI
TL;DR: The present study constitutes the first attempt to characterize the deficient G6PD variants found in Spain and supplies new data on the relationship between molecular characteristics of deficient variants and their clinical manifestations.
Abstract: Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) from thirty-six unrelated spanish males was partially purified from blood, and the variants were characterized biochemically and electrophoretically according to the methods recommended by the World Health Organization. Subjects were from multiple geographic regions within Spain, and all suffered from hemolytic anemia, either acute (34 cases) or chronic nonspherocytic (2 cases). Almost all the variants studied presented residual erythrocyte G6PD activity ranging from 0 to 10% of normal, and five different mutants were responsible for the deficient phenotype. Three variants were similar to others previously described: G6PD Mediterranean (11 cases), G6PD Athens-like (3 cases), and G6PD Union (2 cases). The remaining variants were different from the numerous variants already reported and have been considered as new mutants. Provisionally they are called G6PD Betica (19 cases) and G6PD Menorca (1 case).

Journal ArticleDOI
TL;DR: In this paper, the semisquaric acid skeleton of the natural mycotoxin "moniliformin" was described, starting from di- tert butoxyethyne, and the croconic acid system, via (η-tetra- tert -butoxycyclopentadienone)(η -cyclopentadiyl)cobalt, was reported.


Journal ArticleDOI
TL;DR: 4 patients with chronic photocontact dermatitis were sensitive to cobalt salts and photo‐oxidation tests proved that photosensitizing was responsible for the patients' chronic actinic dermatitis.
Abstract: 4 patients with chronic photocontact dermatitis were sensitive to cobalt salts. They presented as cases of contact dermatitis from cement or pig fodder with persistent lesions on exposed areas. Only 2 of them had standard patch test positive reactions to chromate and cobalt, but all showed positive photo-patch tests to cobalt. Photo-oxidation tests proved that are photosensitizing. Exposure to cobalt salts was responsible for the patients' chronic actinic dermatitis.

Journal ArticleDOI
TL;DR: In this paper, several physical models for conduction calorimetry are presented, including harmonic analysis, time-domain analysis, optimalization method, numerical and electronic filtering, etc.