Showing papers by "University of Alcalá published in 1986"
86 citations
TL;DR: In this article, the basic hydrolysis of 4-acetoxybenzoic acid and 2-naphtylacetate have been studied in cationic micelles of N-cetyl-N, N,N,N-tri-methylaamonium bromide and hydroxide.
71 citations
TL;DR: Results indicate that in spite of reported maternal anabolic changes in the rat at midgestation fat accumulation occurs later in pregnancy when the mother has the highest food intake, which makes available sufficient substrates to support both fetal growth and body lipidic deposition.
58 citations
TL;DR: It is proposed that glycerol derived from enhanced maternal adipose tissue lipolysis constitutes a preferential gluconeogenetic substrate in comparison with others, such as alanine, that are more efficiently transferred through the placenta to the fetus.
Abstract: Studies were conducted to examine the role of gluconeogenetic substrate availability on glucose production in the fasted late pregnant rat. Virgin and 21-day pregnant rats were studied after 24 hours' food deprivation. Pregnant animals showed decreased circulating glucose and gluconeogenic amino acid and increased plasma glycerol concentration. Glucose formation was studied in vivo two, five, and ten minutes after the intravenous administration of two concentrations of /sup 14/C-alanine, /sup 14/C-pyruvate, or /sup 14/C-glycerol. Concentrations of 0.2 mmols of /sup 14/C-glycerol or /sup 14/C-pyruvate, but not of /sup 14/C-alanine, enhanced /sup 14/C-glucose production in pregnant rats, whereas 1 mmol of any of the three /sup 14/C-substrates always enhanced /sup 14/C-glucose production in these rats. Both 1 mmol/L and 5 mmol/L /sup 14/C-alanine increased /sup 14/C-glucose formation in 90-minute-incubated liver slices of fasted pregnant rats, in spite of decreased cytosolic activity of alanine aminotransferase. The three substrates enhanced in vitro renal gluconeogenesis in pregnant rats. Under all experimental conditions studied, labeled glycerol was converted more efficiently into glucose than equivalent amounts of any other substrate used, and this difference was greater in pregnant, than in virgin animals. Results indicate that, in spite of enhanced gluconeogenetic activity, maternal glucose production in the fastedmore » state at late gestation is limited by the deficiency of certain substrates, such as amino acids. It is proposed that glycerol derived from enhanced maternal adipose tissue lipolysis constitutes a preferential gluconeogenetic substrate in comparison with others, such as alanine, that are more efficiently transferred through the placenta to the fetus.« less
44 citations
TL;DR: The in vitro survival of protoscolices of Echinococcus granulosus was investigated for various media and temperatures and Flame cell activity was the criterion of choice for viability.
Abstract: As a first step towards hydatid disease control, the in vitro survival of protoscolices ofEchinococcus granulosus was investigated for various media and temperatures. Higher percentage survival was obtained than previously reported: at 4°C, 100% survival was obtained for 20 days in medium 199 (GIBCO) and for 25 days in hydatid fluid from the host of origin. Maximal survival was 30% at 55 days in these conditions. Flame cell activity was the criterion of choice for viability. At 37°C survival rates were lower and morphological changes in protoscolices were observed.
31 citations
TL;DR: In this article, the pyrrolidine and piperidone rings adopt a flattened N-8 envelope and distorted chair conformation, puckered at n-8 and flattened at C-3, respectively, with the N-substituent in axial position with respect to the piperidine ring.
24 citations
23 citations
TL;DR: Results suggest that insulin may exert a physiological role on the prostatic epithelium by increasing the specific binding of insulin after 96 h of fasting.
Abstract: Insulin receptors have been characterized in rat prostatic epithelial cells by using [125I]insulin and a variety of physicochemical conditions. The binding data at equilibrium (2 h at 15 degrees C) could be interpreted in terms of two populations of insulin receptors: a class of receptors with high affinity (Kd = 2.16 nM) and low binding capacity (28.0 fmol mg-1 protein), and another class of receptors with low affinity (Kd = 0.29 microM) and high binding capacity (1.43 pmol mg-1 protein). Proinsulin exhibited a 63-fold lower affinity than insulin for binding sites whereas unrelated peptides were ineffective. The specific binding of insulin increased by about 50 per cent after 96 h of fasting; this increase could be explained by an increase of both the number of the high affinity-low capacity sites and the affinity of the low affinity-high capacity sites. These results together with previous studies on insulin action at the prostatic level strongly suggest that insulin may exert a physiological role on the prostatic epithelium.
19 citations
TL;DR: In this paper, the chlorides MCl4 (M = Ti, Zr, Hf) react with the diols 4,4′-Me2C(C6H4OH)2 and 1,2-(O)2Ar, and with TlCp to give the monocyclopentadienyl complexes CpTiCl(O2Ar).
18 citations
TL;DR: It is suggested that such secretions contribute to extracellular digestion and that disintegration of the gland cells is accompanied by a differentiation of neoblasts into new gland cells, reflecting a turnover of gland cells during the triclad digestive stages.
Abstract: Light and transmission electron microscopy have been used to study the gastrodermal gland cells of the triclad Dugesia gonocephala s.l. The events involved in the ultrastructural transformation and the secretion process in these cells were followed at four different stages in both fasted and fed animals. During the feeding stage their secretory granules are directly discharged into the intestinal lumen by means of a secretion process of the holocrine type that is described in this paper. It is suggested that such secretions contribute to extracellular digestion and that disintegration of the gland cells is accompanied by a differentiation of neoblasts into new gland cells, reflecting a turnover of gland cells during the triclad digestive stages.
17 citations
TL;DR: In this article, the fractionation of heterogeneous populations of rat and human bone-marrow cells has been studied by countercurrent distribution in a charged 5% dextran-4% poly(ethylene glycol) two-phase system.
TL;DR: The major phospholipids of rat ventral prostate have been separated and examined using thin-layer chromatography, gas chromatography and mass spectrometry to determine the relative proportions of fatty acids in the different phospholIPid classes.
TL;DR: The lack of fetal monoamine response to maternal ethanol intake may be a consequence of the incapacity of fetal liver to form acetaldehyde and the ability of the placenta to oxidize maternal acetaldehyde which protects the fetus from maternal alcohol intake at late gestation.
TL;DR: The specific binding of vasoactive intestinal peptide and the stimulatory effect of VIP upon cyclic AMP accumulation in isolated epithelial cells of rat ventral prostate were age dependent and the number of VIP receptors decreased but the efficiency of VIP on cyclicAMP accumulation increased in prostatic epithelium when considering the periods 35-65 days and 3-6 months.
TL;DR: Condensation d'α-methyl pyridinium, -quinoleiniums and -isoquinoleINiums avec le biacetyle, la phenanthroquinone, l'acenaphtenequinone ou des derives du benzile: obtention de quinolizinium's; a partir de derives α-benzyl, obtorference de dihydro-2,3 indolizINones-2 par cyclisation intramoleculaire as mentioned in this paper.
TL;DR: In this paper, the influence of different parameters, such as fixed ligand, kind and chemical form of the conventional resins, and pH of the aqueous solution, on characteristics and applications of this type of resins has been discussed.
TL;DR: In this article, a method for the simultaneous determination of the true constants in the Mark-Houwink viscosity equation and the absolute calibration of gel permeation chromatography data is described.
TL;DR: Sulfonamides showed maximum binding when their solubilty parameters were similar to the solubility parameters of the amino acids situated in a sequence with one tryptophan residue, which supports the assumption that this sequence is the primary binding site for the sulfonamide.
TL;DR: Krohnke condensation of several cycloimmonium salts with p-dimethylaminobenzaldhyde has been studied X-Ray diffraction, IR and Raman spectra, 1H-and 13C-NMR and UV spectra of the products.
TL;DR: The properties of these binding sites strongly support the concept that somatostatin could behave as a regulatory peptide on the rabbit kidney.
TL;DR: In this article, the appearance of plasma glucose in the inferior cava vein after a pulse of 0.2 mmol of [U- 14 C] l -alanine or [U 14 C]-glycerol/200 g body wt given through the portal vein was studied in fed 21 day pregnant rats and virgin controls under pentobarbital anesthesia.
TL;DR: In this article, the cobalt atom exhibits a distorted trigonal bipyramidal geometry and a final R value of 0.077 ( Rw = 0.061), based on 2656 observed reflections, was obtained.
TL;DR: Condensation of 2-methylthiazoliura salts with 1,2-dicarbonyls in the presence of base, yielded thiazolo-[3,2]-pyridinium derivatives.
TL;DR: A 5BS/5RmS translocation chromosome spontaneously recovered from a ‘Chinese Spring’ has been identified and cytologically studied using C-banding in somatic and meiotic cells, indicating homoeology to wheat chromosome 5BS.
Abstract: A 5BS/5RmS translocation chromosome spontaneously recovered from a ‘Chinese Spring’ — Secale montanum wheat-rye telocentric 5RmS addition line has been identified and cytologically studied using C-banding in somatic and meiotic cells. Analysis of the translocated chromosome showed that a terminal segment of the short arm of 5B had been replaced by a short terminal region of chromosome arm 5RmS. The translocation led to the deletion of the genetic system promoting pairing located in 5BS, which is slightly compensated for when doses of 5RmS are increased, indicating homoeology to wheat chromosome 5BS. The α-amylase phenotype in 5B/5Rm translocated material was studied and found to be identical to that of ditelocentric line 5BL of ‘Chinese Spring’. An effect on the α-amylase activity was detected as a result of the removal of the terminal region of 5BS, perhaps as a consequence of variation in dormancy period duration.
TL;DR: The reaction of the compounds TaXCl4 with o-diphenols 4-RC6H3(OH)2 (R = H, Me, But gave the dialkoxides XCl2Ta(O2C 6H3R), whereas the reaction with 4,4′-isopropylidenediphenol gave the monoalkoxides [TaXCl3]2[(OC6H4)2CMe2] as mentioned in this paper.
TL;DR: In this article, the structure of PF 6 has been determined by X-ray diffraction using gold(I) salts, and the reaction of [Nb{η 5 -C 5 H 4 Si(CH 3 ) 3 } 2 {AuP(C 6 H 5 ) 3 ] PF 6 was determined.
TL;DR: The reaction of different 2-amino-4H-pyrans (1, 10) with guanidine affords 2,6-diaminopyrimidine derivatives as mentioned in this paper.
Abstract: The reaction of different 2-amino-4H-pyrans (1, 10) with guanidine affords 2,6-diaminopyrimidine derivatives (3). Treatment of the pyrans mentioned or their acetylated derivatives with trityl tetrafluoroborate does not yield pyrylium salts, and pyrid-2-one systems (8, 11, 14) are obtained from the 2-amino-4H-pyrans (1, 10, 13) on treatment with H2SO4/ethanol.
TL;DR: Results do not support a trophic role of insulin on intestinal mucosa and appear to be more a consequence of the hyperactive status of proliferation and differentiation at the mucosat level.
Abstract: Partial (60%) resection of rat small bowel was performed in order to obtain a model of intestinal mucosal hyperplasia for studying specific insulin binding. The affinity, but not the binding capacity, of insulin receptors in the adaptive mucosa decreased three and seven days following enterectomy. This modification took place only in crypt cells but not in mature villous cells. Since plasma insulin levels were not altered by the surgical manipulation, the observed decrease of insulin binding could not be related to regulation by insulin concentration. These results do not support a trophic role of insulin on intestinal mucosa and appear to be more a consequence of the hyperactive status of proliferation and differentiation at the mucosat level.
TL;DR: Results suggest that a decrease in the endogenous immunoreactive somatostatin might lead to up-regulation of somatstatin binding sites in the gastric fundic mucosa.
Abstract: 1. 1. Cysteamine, when given in vivo to rabbits, depleted immunoreactive somatostatin in rabbit gastric fundic mucosa. 2. 2. Depletion of immunoreactive somatostatin was associated with both an increase in the number and a decrease in the affinity of the low-affinity somatostatin binding sites. 3. 3. The in vitro incubation of cysteamine (0.1 mM) with the cytosolic fraction did not result in any modification of somatostatin binding. 4. 4. These results suggest that a decrease in the endogenous immunoreactive somatostatin might lead to up-regulation of somatostatin binding sites in the gastric fundic mucosa.
TL;DR: In this article, a study of the kinetic behavior of calcium oxalate dehydration using TG data is reported, and the discrimination among non-separable variables models is carried out in a differential form.