Showing papers by "University of Barcelona published in 1983"

Sympathetic nervous activity, renin-angiotensin system and renal excretion of prostaglandin E2 in cirrhosis. Relationship to functional renal failure and sodium and water excretion.

Abstract: . To investigate if functional renal failure in cirrhosis could be related to disturbances of vasoactive systems, plasma renin activity, plasma catecholamines and urinary prostaglandin E2 (PGE2) were determined in twenty-two normal subjects and sixty-five cirrhotics. Furthermore, in thirty-three of these subjects, the effect of lysine-acetylsalicylate (450 mg i.v.) on renal function was studied. Patients with ascites without renal failure showed higher renin, noradrenalin and urinary PGE2 than normal subjects (5.9±0.8 v. 1.1±0.1 ng ml-1 h-1, P < 0.001; 512 ± 39 v. 224±17 pg/ml, P < 0.001; and 603 ± 71 v. 377±36 ng/day, P < 005, respectively). Patients with functional renal failure showed higher (P < 0001) renin (13.5±1.9) and noradrenalin (1114±134) and lower (P < 005) urinary PGE2 (199 ± 36) than normal subjects and cirrhotics without renal failure. On the whole, patients glomerular filtration rate correlated (P < 0001) with urinary PGE2 (r= 0.55), renin (r=-0.52) and noradrenalin (r=-0.52). Lysine-acetylsalicylate did not alter renal function in normal subjects and cirrhotics without ascites. However, it reduced water diuresis (8.8 ± 0.9–2.7 ± 0.5 ml/min) and sodium excretion (from 57.1 ± 13.9 to 3.9 ± 11 μmol/min) in all the nineteen cirrhotics with ascites studied and the glomerular filtration rate (95.4 ± 11.8–46.7 ± 9.5 ml/min) in eleven of these patients. Urinary PGE2 decreased in all patients (3.13 ± 0.65–0.54 ± 0.11 ng/min). The study suggests that: (a) functional renal failure in cirrhosis with ascites may be a consequence of an imbalance between vasoactive systems, (b) renal prostaglandins are involved in the tubular handling of sodium and water in these patients.

Reduced Hepatic Insulin Extraction in Obesity: Relationship with Plasma Insulin Levels

Abstract: To elucidate if there are alterations in insulin metabolic clearance in obesity under basal conditions, plasma insulin and C-peptide were measured in 22 obese patients and 8 normal subjects, and the plasma C-peptide to insulin molar ratio was used as an index of hepatic insulin extraction. In obese patients, the C-peptide to insulin molar ratio correlated indirectly with basal plasma insulin levels (r = 0.71; P less than 0.001), being low in the obese patients with higher insulin levels and within the normal range in obese patients in which insulin levels were similar to those of control subjects. It is suggested that hepatic insulin extraction is decreased in obesity, even under basal conditions, but this alteration is only manifested when plasma insulin levels are high.

Circulating triacylglycerols, lipoproteins, and tissue lipoprotein lipase activities in rat mothers and offspring during the perinatal period: effect of postmaturity.

Abstract: Mammary gland and adipose tissue lipoprotein lipase activities have been implicated in the changes of circulating triacylglycerol levels which occur in the mother at late gestation. In the newborn the temporal accumulation of triacylglycerols in the liver coincides with the appearance of a lipoprotein lipase peak. The relationships of these changes with the rise in circulating prolactin in the mother before parturition and the extrauterine nutritional status in the offspring were studied in a postmaturity model produced in the rat by subcutaneous injection of 7 mg progesterone/day to pregnant animals from the 20th day of gestation. Pregnant controls received the medium. Parturition occurred at day 21.5 of gestation in pregnant controls while it did not occur before the 23rd day in those receiving progesterone. At the 20th day of gestation, plasma triacylglycerol concentrations and all lipoprotein fractions (especially VLDL) were much higher in mothers not receiving progesterone than in age-matched virgins, and these differences disappeared at the 21st day of gestation. Lipoprotein lipase activity was maintained low in control mothers' adipose tissue until the 23rd postfecundation day while it greatly increased in mammary gland from parturition time. In progesterone treated mothers, both triacylglycerol and lipoprotein fractions (especially VLDL) in plasma were maintained elevated until the 23rd postfecundation day and adipose tissue and mammary gland lipoprotein lipase activities were maintained low until this time. Circulating prolactin levels increased around parturition in control mothers while they did not change in the progesterone treated mothers at any of the times studied. In offspring from control mothers, plasma triacylglycerols were low and their most abundant circulating lipoprotein fraction appeared to be LDL. In contrast to mother's liver, in offspring liver a marked lipase activity with all the inhibitory characteristics of lipoprotein lipase in the presence of both NaCl and protamine sulfate appeared around birth, coinciding with a sharp increase in liver triacylglycerol concentration and plasma ketone body levels. In postmature fetuses, liver lipoprotein lipase activity and triacylglycerol content decreased from the 20th to the 23rd postfecundation day while levels of both acetoacetate and beta-hydroxybutyrate rose in blood. Results indicate that increased mammary gland lipoprotein lipase in the mother may play a role in the decline of hypertriglycerolemia before parturition and that the initial change is driven by the rise in circulating prolactin at that time. On the contrary, the reduction in adipose tissue lipoprotein lipase activity in late gestation is not associated with the increase in circulating prolactin levels. We speculate that in offspring from control mothers, the high fat content of the mother's milk produces a substrate induction mechanism on liver lipoprotein lipase converting the liver of the newborn into a temporary lipid storage organ. Consumption of endogenous resources and maintenance of maternal ketone bodies transfer through the placenta ensure development of postmature fetus.

Pisoids in the Caliche Profiles of Tarragona (N.E. Spain)

Abstract: Caliche with pisolitic horizons have been recognized in the soils in the Mediterranean coast area of Spain from Almeria to Barcelona and Lleida. In the southern area the pisolitic horizons develop on old calchified aluvial fans as well as on volcanic rocks. In the middle and north of the Mediterranean coast they appear overlaying carbonate and metamorphic rocks.

Prevalence and prognosis after a first nontransmural myocardial infarction.

Abstract: Prevalence, prognosis, and coronary anatomy associated with nontransmural myocardial infarction (MI) were prospectively assessed in 458 consecutive men admitted to our coronary care unit with a first MI. Cardiac catheterization was performed in 402 of the 436 survivors within 1 month of the acute event. Mean follow-up was 33 months (range 5 to 72). Nontransmural MI was diagnosed in 28 patients (6%). These patients were younger (46 ± 10 versus 51 ± 7 years, p 90%) in the involved artery (p

Respiratory properties of developing bean and pea leaves

Abstract: The rate of O2 uptake in the dark in bean leaves and leaf slices decreased during development. The use of inhibitors of the cytochrome and alternative pathways and the uncoupier carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) indicated that this decline was largely due to a decline in the activity and capacity of the cytochrome path. However, the capacity of the alternative path remained more or less constant with leaf expansion, and thus percentage cyanide resistance of respiration increased with leaf expansion. The activity of the alternative path was small in bean leaves and leaf slices, and decreased during development. Respiration, mainly the cytochrome pathway, of bean leaf slices was stimulated by FCCP at all ages, the stimulation being more pronounced in young leaves. The rate of overall respiration, the activities of the cytochrome and alternative paths, and the extent to which FCCP stimulated respiration in bean leaf slices were positively correlated with endogenous free sugar levels during aging. Similar trends were observed with mitochondria isolated from pea leaves. Leaf mitochondria from older plants had lower cytochrome path capacity, but the capacity of the alternative path remained much the same as that in leaf mitochondria from seedlings.

Levels of Inhibin-F Activity and Steroids in Human Follicular Fluid from Normal Women and Women with Polycystic Ovarian Disease*

Abstract: To examine inhibin-F activity (FSH-suppressing activity) in human follicular fluid of polycystic ovary (PCO) patients, 13 follicles from 5 documented PCO patients and an additional 31 follicles from normal women in the follicular phase of the menstrual cycle were sampled, and inhibin-F activity was measured in rat anterior pituitary cell cultures. Inhibin-F activity was measured in follicular fluid after stripping steroids from the fluids using treatment with dextran and activated charcoal. Estrogen, progesterone, and delta 4-androstenedione in the follicular fluid were also determined by RIA. Estrogen and progesterone levels in follicular fluid from PCO follicles 3.9 +/- 0.34 mm in diameter were comparable with those in follicular fluid obtained from viable follicles (which had a delta 4-androstenedione to estrogen ratio of 10 or less) from normal women. delta 4-Androstenedione levels in PCO follicles were higher (P less than 0.01) than those in viable and atretic follicles of normal women. Inhibin-F levels in PCO follicles were comparable to those in viable follicles, but significantly greater (P less than 0.01) than levels in atretic follicles of normal women. If inhibin-F levels in both atretic and viable follicles of normal women were pooled, the levels were less (P less than 0.05) compared to the level in PCO follicular fluid. As an additional control, follicular fluid was collected from 90 follicles of normal women throughout the menstrual cycle, and follicular size was determined as well as inhibin-F and steroid content. Small follicles less than 8 mm; (comparable in size to the PCO follicles examined) obtained at each stage represented 79%, 24%, 0%, and 94% of the total follicles obtained in the early to midfollicular, late follicular, preovulatory, and luteal phases of the cycle, respectively. Inhibin-F activity in the fluids of these follicles was less than that in PCO follicular fluid. The average inhibin content of all of the small normal follicles was 197 +/- 34 U/10 microliter, which was significantly less (P less than 0.05) than the level in PCO follicles (332 +/- 13 U/10 microliters). These data represent the first observation of inhibin-F activity in PCO follicular fluid and suggest the possibility of involvement of inhibin-F in bringing about low or normal basal levels of FSH in the presence of elevated basal LH levels often observed in PCO patients.

Collapse and explosion of white dwarfs. I - Precollapse evolution

Abstract: The long-term evolution of accreting carbon-oxygen white dwarfs in close binary systems is considered. Depending on the time of onset of mass accretion (for a given stellar mass), thermonuclear ignition happens when the star's center is either in the fluid or in the solid phase. In the last case, burning propagation should be slow, and previous carbon-oxygen separation is likely. We show that by considering different degrees of chemical separation (associated with different cooling times) diverse outcomes are possible: total collapse for maximum separation and off-center ignitions for partial chemical differentiation. The off-center ignitions might provide a mechanism for Type I supernova outbursts, and, by implying the explosive burning of varying amounts of the carbon-oxygen mixture, they might also explain the ''fast'' to ''slow'' SN I range.

Modification of 5'-nucleotidase activity by divalent cations and nucleotides.

Abstract: The 5′-nucleotidase activity of the purified cytoplasmic fraction preparation of bovine brain does not depend on the presence of the divalent metal ions Mg2+, Ca2+, and Cu2+ in the incubation medium. The Zn2+ ion (0.5 mM) causes total enzyme inhibition. Although EDTA and 8-hydroxyquinoline inhibit the 5′-nucleotidase from this source, it has not been possible to show the existence of metal ions in the enzyme molecule. The inhibition of 5′nucleotidase by EDTA is progressive and irreversible; when the enzyme is not preincubated with EDTA, the inhibition is overridden by metal ions. The purines (except xanthine, 0.3 mM), pyrimidines, and their nucleosides do not affect the 5′-nucleotidase activity. The nucleoside di- and triphosphates are competitive enzyme inhibitors against 5′-AMP as substrate. The K1 values of the diphosphates are lower than those determined for the corresponding triphosphates. The inhibition caused by the above nucleotides is reversed, partly or wholly, by Mg2+, depending on the molar ratio between the effectors. The inhibitory action of the -SH group reagents on the 5′-nucleotidase activity is weak and reversible.

Notas sobre la implantacion y el desarrollo de la industria del gas en España, 1840–1901

Abstract: La Espana del siglo xix ha sido calificada, en su aspecto economico, como «rezagada con respecto a la mayoria de las naciones occidentales», aunque alejada «igualmente de aquellas otras que no han iniciado su industrializacion hasta muy entrada la centuria actual». Nos encontramos, pues, ante un caso intermedio, en el que la aparicion de iniciativas de caracter moderno no se vio acompanada por su desarrollo a un nivel comparable con el de los paises pioneros de la industrializacion.

Limnology of Gallocanta Lake, Aragon, northeastern Spain

Abstract: A limnological study was sustained from September 1980 to October 1981 to show the evolution of Gallocanta Lake (N.E. Spain) under very dry climatic conditions. It is the physical terminus within an endorheic basin of 500 km2 situated 1 000 m over the sea level. In 1977 its maximum depth was 2.5 m but it decreased to 60 cm in 1981 as a consequence of the last very dry years. It is actually 6 km long and 2.5 km wide, and its area is approximately 12 km2. Salt concentration was quite constant (32–43 g l-1) since September 1980 until June 1981. The equivalent ratio Cl-:SO inf4 sup2- varied between 2.2 and 2.8. From June through October 1981 salinity increased up to 105 g l-1 and Cl-:SO inf4 sup2- equivalent ratio varied between 2.5 and 3.4. The relative concentrations of ions were retained all year ordinated as follows: Cl- > SO inf4 sup2- > HCO inf3 sup- >. CO inf3 sup2- ; Na+ > Mg2+ ≫ Ca2+ > K+. Total reactive phosphorus was less than 1.5 µg-at l-1 from September 1980 to January 1981. During the rest of the studied period it varied between 2 and 8 µg-at l-1 (the maximum, in February 1981). Nitrogen oxidized forms were relatively high in winter (4–8 µg-at N-NO inf3 sup- l-1; 0.5–2.5 µg-at N-NO inf2 sup- l-1), and early May 1981 (25 µg-at N-NO inf3 sup- l-1; 1 µg-at N-NO inf2 sup- l-1). Neither reached 1 µg-at l-1 from September through December 1980, or from June through October 1981. Planktonic algae increased in density during the period of the study from 103 to 5 105 cells ml-1. Chromulina sp. was the main species during autumn and winter (>50% in number of cells ml-1) while the copepod Arctodiaptomus salinus decreased its population. Lobocystis dichotoma increased its density from December 1980 to May 1981 and was dominant in spring (>90%), when a typical reproductive activity was observed in the Arctodiaptomus population. This species disappeared in late spring. In June 1981 Brachionus plicatilis reached up to near 2 000 individuals ml-1. This species was not observed after August 1981. Then the ciliate Fabrea salina was the only zooplankter staying in the free waters of the lake and Nannochloris sp. the dominant alga (>90%). Dense macrophytic beds constituted of Lamprothamnium papulosum and Chara galioides covered the bottom of the lake in September 1980 and before that date since the observations began in 1977. They decreased in covered area since October 1980 and disappeared during summer 1981. Gallocanta Lake is in a very stressed situation produced by prolonged drought. The increased salt concentration together with the extremely cold and hot temperatures, and the lack of nitrogen relative to phosphorus are the main environmental factors that controlled the biological populations during the period of the present study.

Joint probability distribution of Nonmarkovian SDE

Abstract: We obtain a time convolutionless partial differential equation for the two events joint probability distribution of nonmarkovian processes defined by stochastic differential equations with colored noise. As an example we discuss nonmarkovian brownian motion.

Exact quasiconvex conjugation

Abstract: In this article we develop a conjugacy theory in quasiconvex analysis, in which no lower semicontinuity or normality assumption is needed to ensure the coincidence of the second conjugate of any function with its quasivonvex hull. This is made by an extension of the concept ofH-conjugation, and is based on a separation theorem by general halfspaces. The theory is applied in mathematical programming to define dual problems, which consist in maximizing a quasiconcave function of matricial variable, the optimum being always attained. The absence of duality gap is equivalent to the quasiconvexity of the perturbation function at the origin. A Lagrangian for general problems is studied and compared with the one of Luenberger in the case of vertical perturbations.