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A Alonso

Publications and source records attributed to A Alonso.

At least 415 records · Page 23Linked to original sources
PubMed1987

Differential transcription of the repetitive R-element in various mouse cell types.

Clones that contain R-elements separated from the rest of the L1-repeat have been isolated from a mouse genomic DNA library. Spot hybridization of DNA from various species (from mammals to plants) with one representative and well characterized mouse DNA clone shows that at least this sequence hybridizes only with mouse DNA. In addition, we demonstrate that the R-element repeat is transcribed differentially in various tissues or cell types. Furthermore, the amount of R-transcripts is regulated at varying rates in the different cell types of a tissue as shown by in situ hybridization.

Animals↗
PubMed1987

Slimming treatment efficiency and changes in serum lipids and lipoproteins in obese adolescents.

The efficiency of a slimming treatment, which is the quantity of lean body mass (LBM) lost for each kilogram of body fat reduced, measured by Efficiency Index (EI), was investigated in nineteen obese male adolescents aged 10-14 years who lost weight during four weeks of a treatment combining hypoenergetic diet (0.18 MJ/kg of expected body weight for stature), physical exercise and psychological support. Anthropometric assessment of adiposity including body composition using Parízková and Roth's regression equations was made before onset of treatment and after 7, 14 and 28 days. Simultaneously, blood samples were drawn for serum lipids and lipoproteins. A total of seventy six observations and assessments of treatment efficiency and changes of lipid profile between every two observations were carried out. Significant correlations were found between EI values and changes in Total Cholesterol and Total Cholesterol/HDL Cholesterol ratio at the three evaluations carried out. Though HDL-Cholesterol level increase was not significant, its variations were strongly correlated with EI during the first and second assessments. Differences found in the magnitude of increase in nonesterified fatty acids (delta NEFA), suggest that lipolytic mechanisms were not uniformly impaired. Treatment efficiency and delta NEFA were lower in subjects with lesser adiposity related to muscle mass at the middle third of the upper arm (measured through Energy/Protein Index). Triglycerides and LDL + VLDL Cholesterol levels showed little variations. The achievement of a high treatment efficiency is not only necessary for preserving growth, but also for the significant decrease which occurs in some lipid fractions when EI is below 0.5.

Adolescent↗
PubMed1987

Genetic markers in late paraphrenia: a study of HLA antigens.

Patients with late paraphrenia were typed for HLA-A, -B and -C. Increased frequencies of BW55 (P = 0.036), B37 (P = 0.008) and CW6 (P = 0.056) were found relative to controls. Unlike findings in paranoid schizophrenia, there was no HLA-A9 association, suggesting that paraphrenics may be genetically distinct from schizophrenics. The primary association seems to be with B37, which has the lowest corrected P value and highest relative risk; if this were replicated, it would make possession of this antigen a strong risk factor for developing the disorder.

Aged↗
PubMed1987

The use of separator isoelectric focusing in micro-ultrathin polyacrylamide gels in the characterization of some polymorphic proteins of forensic science significance.

The identification of phenotypes of erythrocyte acid phosphatase (EAP), esterase D (EsD), group specific component (Gc), and alpha-1-antitrypsin (PI) by separator isoelectric focusing in micro-ultrathin polyacrylamide gels (interelectrode distance: 45 mm) is described. The protein patterns obtained are compared favorably with the patterns seen by isoelectric focusing in conventional polyacrylamide gel dimensions (interelectrode distance: 110 to 120 mm). The technique described allows greater stability of pH gradients and is a fast and economic method.

Blood Protein Electrophoresis↗
PubMed1987

HLA associations with multiple sclerosis in Sicily and Malta.

The islands of Sicily and Malta have very different prevalence rates for multiple sclerosis (MS): at least 44 per 100,000 in Sicily and only 4 per 100,000 in Malta. In Northern Europe, MS is associated with HLA-DR2/Dw2. The other components of the commonest DR2-containing haplotype of this region, HLA-A3-B7-DR2-Dw2, also tend to be present at higher frequency in MS patients. HLA Class I and II antigen frequencies and associations in controls and MS patients from Sicily and Malta were studied to discover whether they might account for the difference in MS prevalence. In Sicilian MS patients, DR2 is increased in frequency compared with controls and four out of five DR2-positive patients also type as Dw2. In the Maltese population, DR2 is present at high frequency but approximately half of the DR2 positive individuals do not type as Dw2 so that DR2 is probably most commonly present as part of Class II haplotypes other than those commonly associated with MS. Additional differences in HLA profile of the Sicilian and Maltese populations were found when HLA-A, -B, and B-DR antigen associations were examined. Therefore, some of the difference in MS prevalence might be explained by genetic factors.

Cross-Sectional Studies↗
PubMed1987

Changes in body composition and serum lipid fractions after four weeks of slimming treatment: results in nineteen obese male adolescents.

The changes in body composition and in serum levels of total cholesterol (T-chol), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), very low plus low density lipoprotein cholesterol (VLDL + LDL-C), the ratio T-chol/HDL-C and non esterified fatty acid (NEFA) were studied in nineteen obese male adolescents after 28 days of slimming treatment which consisted in hypoenergetic diet and exercise. Relative fat body weight (%BF) was calculated by Parizková and Roth's regression equations for five fatfolds and lean body weight was obtained as the difference between body weight and fat body weight. Significant reductions in %BF, T-chol and T-chol/HDL-C ratio were found. The decrease in TG was not significant but had a better correlation with the reduction of adiposity (delta %BF) than the previously mentioned two variables. The increase of lipolysis during the four weeks of study is expressed in the significant rise of NEFA and its correlation (r = -0.714) with delta %BF. A tendency to increase in HDL-C could be observed, and a significant inverse correlation (r = -.804) with delta %BF was found. The results obtained showed that the combination of diet and exercise for treating obesity in adolescents influences favourably the risk factors of ischaemic heart disease related to serum lipid and lipoprotein profiles and does not significantly affect lean body mass, at least up to four weeks.

Adolescent↗
PubMed1986

The interaction of phosphatidylcholine bilayers with Triton X-100.

The interaction of multilamellar phosphatidylcholine vesicles with the non-ionic detergent Triton X-100 has been studied under equilibrium conditions, specially in the sub-lytic range of surfactant concentrations. Equilibrium was achieved in less than 24 h. Estimations of detergent binding to bilayers, using [3H]Triton X-100, indicate that the amphiphile is incorporated even at very low concentrations (below its critical micellar concentration); a dramatic increase in the amount of bound Triton X-100 occurs at detergent concentrations just below those producing membrane solubilization. Solubilization occurs at phospholipid/detergent molar ratios near 0.65 irrespective of lipid concentration. The perturbation produced by the surfactant in the phospholipid bilayer has been studied by differential scanning calorimetry, NMR and Fourier-transform infrared spectroscopy. At low detergent concentration (lipid/detergent molar ratios above 3), a reduction in 2H-NMR quadrupolar splitting occurs, suggesting a decrease in the static order of the acyl chains; the same effect is detected by Fourier-transform infrared spectroscopy in the form of blue shifts of the methylene stretching vibration bands. Simultaneously, the enthalpy variation of the main phospholipid phase transition is decreased by about a third with respect to its value in the pure lipid/water system. For phospholipid/detergent molar ratios between 3 and 1, the decrease in lipid static order does not proceed any further; rather an increase in fluidity is observed, characterized by a marked decrease in the midpoint transition temperature of the gel-to-fluid phospholipid transition. At the same time an isotropic component is apparent in both 31P-NMR and 2H-NMR spectra, and a new low-temperature endotherm is detected in differential scanning calorimetric traces. When phospholipid and Triton X-100 are present at equimolar ratios some bilayer structure persists, as judged from calorimetric observations, but NMR reveals only one-component isotropic signals. At lipid/detergent molar ratios below unity, the NMR lines become narrower, the main (lamellar) calorimetric endotherm tends to vanish and solubilization occurs.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1986

Distribution of neurons in the main cuneate nucleus projecting to the inferior olive in the cat. Evidence that they differ from those directly projecting to the cerebellum.

The distribution in the main cuneate nucleus of cells projecting to the inferior olive and the intermediate zone of the cerebellar anterior lobe were compared by means of double retrograde labeling methods in the cat. The tracer combinations were either Fast Blue and Diamidino Yellow Dihydrochloride; or horseradish peroxidase conjugated to wheat germ agglutinin and Diamidino Yellow Dihydrochloride. Neurons in the caudal, middle and rostral subdivisions of the main cuneate nucleus project to the inferior olive. Differences exist, however, in its number and location along the rostrocaudal extent of the nucleus. Cells projecting to the inferior olive predominate in the caudal and middle subdivisions, where they concentrate ventrally. No cells in the "clusters region" project to the inferior olive. Main cuneate nucleus neurons projecting to the cerebellum concentrate rostral to the obex, bordering the external cuneate nucleus and partially intermixing with the rostrally located cells projecting to the inferior olive. However, no double-labeled cells were found. The results indicate that the main cuneate nucleus projections to the inferior olive and cerebellar anterior lobe originate from different populations of neurons with high specific locations within the nucleus. This finding is in agreement with previous studies suggesting that each of the main cuneate nucleus targets receives its input from a distinct population of neurons within the nucleus.

Animals↗
PubMed1986

HLA antigens in palindromic rheumatism and palindromic onset rheumatoid arthritis.

Fifty patients who presented with typical palindromic rheumatism of at least 6 months' duration were tissue-typed for HLA A, B, C antigens. DR typing was also performed but was not possible for technical reasons in three patients. Twenty-three patients who had progressed to definite or classical rheumatoid arthritis (RA) after a mean interval of 5 years were compared with 20 patients whose palindromic attacks had persisted over a similar period. Both groups showed a significantly higher frequency of DR4 antigen than a control population. The RA group also showed an increased frequency of DR1. There was no significant difference in the frequency of DR4 or any other DR antigen between the two patient groups. The frequency of B27 antigen was significantly higher in the palindromic group compared with the controls. It is suggested that although DR4 may be associated with a tendency to inflammatory joint problems, environmental or other unrelated genetic factors may be more important in determining the progression of palindromic rheumatism to RA.

Arthritis, Rheumatoid↗
PubMed1986

Characterization of cloned sequences complementary to F9 cell double-stranded RNA and their expression during differentiation.

In a cDNA library prepared from the RNA of cultured murine F9 teratocarcinoma cells, we identified sequences exhibiting strong hybridization to double-stranded RNA (dsRNA) of F9 cells but weak hybridization to mouse liver dsRNA. Northern-blot hybridization of RNA extracted from F9 cells with or without treatment with retinoic acid revealed differences in the expression of some of these sequences in undifferentiated and differentiated cells. As shown by Southern-blot hybridization experiments, these differences of expression were not related to a gross rearrangement of the corresponding genomic DNA sequences of the differentiated cells. When RNA from F9 cells was used, one of the cloned dsRNA-related sequences selected mRNA which was translated in vitro to a polypeptide with an Mr of 24,000; the level of this mRNA was reduced in F9 cells that had been treated with retinoic acid. Our results show that the differentiation of F9 cells induced by retinoic acid results in the differential expression of some middle-repetitive sequences.

Animals↗
PubMed1986

HLA and rheumatoid arthritis: an analysis of multicase families.

In a study of multicase RA families, significantly raised frequencies of the HLA antigens DR4, DR1, Bw62, Cw3, A2, A31 and significantly lower frequencies of DR2, DR3, and B8 were found in probands compared to normal controls. When haplotype frequencies were compared between probands and controls, two haplotypes A2-B44-DR4 and A2-Bw62-DR4 were at higher frequency in probands. These differences no longer reached significance when only DR4-containing haplotypes were compared between probands and controls. A significantly lower haplotype frequency of A1-B8-DR3 was observed in probands compared to controls. This difference did not remain significant when only non-DR4 haplotypes were compared. Using an affected sibling pair ratio method, significant linkage between HLA and RA was found (P less than 0.01). Significant linkage was also observed between HLA and seropositivity. Analysis of Hardy-Weinberg equilibrium for the DR locus did not support the suggestion that DR4-associated RA susceptibility was inherited as a dominant trait. In addition it did not support the notion of an additive effect of DR4 and DR1 in RA susceptibility as these antigens were not found together more frequently than predicted by their individual gene frequencies.

Arthritis, Rheumatoid↗
PubMed1986

HLA frequency and haplotype analysis in a family study of adult onset rheumatoid arthritis.

Twenty-five families with probands who have rheumatoid arthritis (RA) were studied for clinical evidence of disease and for HLA status. This confirmed an association between RA and DR4 in 19/25 probands (76 per cent, p = 0.008). These 19 probands carried 24 haplotypes which contained DR4. There was no significant increase of DR4 haplotypes bearing B15(Bw62) or B44 when compared with published control haplotype data. The rare complement allele C4 B3 was detected as part of the extended haplotype A2 Cw3 B15(Bw62) DR4 C4 A*3B*3 in three probands with severe RA. Further studies to examine disease severity and autoantibody expression are in progress.

Arthritis, Rheumatoid↗
PubMed1985

The effect of bilayer order and fluidity on detergent-induced liposome fusion.

Surfactants induce fusion (or increase in size) of sonicated liposomes. This phenomenon is enhanced by cholesterol and inhibited by the intrinsic polypeptide gramicidin A. By comparison with previous physical studies we conclude that liposome 'fusion' is facilitated when both fluidity and static order of the bilayer are high.

Cholesterol↗
PubMed1985

Transport of ethanol in baker's yeast.

Ethanol is transported into various strains of baker's yeast by simple diffusion (no effect of inhibitors and a linear concentration dependence of the initial rate of uptake and final distribution in cells). It distributes itself in 96.6 +/- 16.2% of intracellular water.

Biological Transport↗
PubMed1985

Colorimetric assay of gramicidin A in the presence of surfactants and phospholipids.

Gramicidin A, a hydrophobic polypeptide containing 4 tryptophan residues/molecule, may be determined quantitatively after reaction with 4-(dimethylamino)benzaldehyde, a method previously proposed for tryptophan analysis. The assay may be carried out even in the presence of various surfactants and phospholipids at high concentrations.

Benzaldehydes↗