Search Results - (Author, Cooperation:A. Quintana)

2013-11-16

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Brain/drug effects/enzymology/pathology ; Disease Models, Animal ; Electron Transport Complex I/genetics/metabolism ; Glycolysis/drug effects ; Leigh Disease/*drug therapy/genetics/pathology ; Mice ; Mice, Knockout ; Mice, Mutant Strains ; Mitochondria/drug effects/enzymology ; Mitochondrial Diseases/*drug therapy/genetics/pathology ; *Molecular Targeted Therapy ; Multiprotein Complexes/*antagonists & inhibitors ; Neuroprotective Agents/*therapeutic use ; Sirolimus/*therapeutic use ; TOR Serine-Threonine Kinases/*antagonists & inhibitors

2013-06-25

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Calcium/*metabolism ; Calcium Channels/metabolism ; Calcium Signaling ; Cell Membrane/metabolism ; Endoplasmic Reticulum/metabolism ; Genome, Human ; HeLa Cells ; Humans ; Membrane Proteins/metabolism ; NFATC Transcription Factors/*metabolism ; Neoplasm Proteins/metabolism ; Protein Transport ; *RNA Interference ; RNA, Small Interfering/*genetics ; Septins/deficiency/genetics/*metabolism ; Signal Transduction

0935-6304

High performance liquid chromatography, HPLC ; Adsorption HPLC system ; Partition reverse phase HPLC system ; Valproic acid, VPA ; Antiepileptic drugs, AEDs ; O-p-Nitrobenzil-N,N′-diisopropylisourea, PNBDI ; Enzyme immunoassay, EMIT ; Chemistry ; Analytical Chemistry and Spectroscopy

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

A sensitive and specific method for the determination of valproic acid in plasma has been developed. After the proteins in the plasma have been precipitated with a saturated solution of ammonium sulfate in 1N HCl, the valproic acid, together with the internal standard, is extracted from the plasma with dichloromethane.An aliquot of the organic solution is taken for derivatization of the valproic acid and the internal standard with O-p-nitrobenzyl-N,N′-diisopropylisourea.Separation is carried out by HPLC using two chromatographic systems: an adsorption system with a μ Porasil column, hexane-chloroform (94:6) as mobile phase, and caproic acid as internal standard and a partition reverse phase system comprising a μ Bondapak TM/C18 column, acetonitrile/methanol/0.0035 M phosphate buffer (60:10:30), and caprylic acid as internal standard. UV detection is at 254 nm.This method, developed in both systems, permits the determination of plasma levels of valproic acid in the reported range of 50-100 μg/mL. With adequate sensitivity, specificity, precision, and accuracy.The plasma levels of valproic acid may be determined by this method without interference from the commonest antiepileptic drugs. Good correlation is obtained with the enzymatic immune analytic method: EMIT.

7 Ill.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The line tension concept is used to generalize the classical theory of heterogeneous nucleation. The theory is applied to study the impingement flux-temperature diagram of nucleation. The epitaxial nucleation zone at the diagram can be drastically modified depending on the sign of the line tension. Line tension also gives place to a new zone of no nucleation due to spreading effects.

Electronic Resource

1130-2097

Philosophy

CRÍTICA DE LIBROS

1432-1432

Alcohol dehydrogenase ; Drosophila ; Drosophila lebanonensis ; Gene expression ; Codon usage ; Phylogenetic relationships

Springer Online Journal Archives 1860-2000

Biology

Abstract The region of the genome of D. lebanonensis that contains the Adh gene and the downstream Adh-dup gene was sequenced. The structure of the two genes is the same as has been described for D. melanogaster. Adh has two promoters and Adh-dup has only one putative promoter. The levels of expression of the two genes in this species are dramatically different. Hybridizing the same Northern blots with a specific probe for Adh-dup, we did not find transcripts for this gene in D. lebanonensis. The level of Adh distal transcript in adults of D. lebanonensis is five times greater than that of D. melanogaster adults. The maximum levels of proximal transcript are attained at different larval stages in the two species, being three times higher in D. melanogaster late-second-instar larvae than in D. lebanonensis first-instar larvae. The level of Adh transcripts allowed us to determine distal and proximal initiation transcription sites, the position of the first intron, the use of two polyadenylation signals, and the heterogeneity of polyadenylation sites. Temporal and spatial expression profiles of the Adh gene of D. lebanonensis show qualitative differences compared with D. melanogaster. Adh and Adh-dup evolve differently as shown by the synonymous and nonsynonymous substitution rates for the coding region of both genes when compared across two species of the melanogaster group, two of the obscura group of the subgenus Sophophora and D. lebanonensis of the victoria group of the subgenus Scaptodrsophila. Synonymous rates for Adh are approximately half those for Adh-dup, while nonsynonymous rates for Adh are generally higher than those for Adh-dup. Adh shows 76.8% identities at the protein level and 70.2% identities at the nucleotide level while Adh-dup shows 83.7% identities at the protein level and 67.5% identities at the nucleotide level. Codon usage for Adh-dup is shown to be less biased than for Adh, which could explain the higher synonymous rates and the generally lower nonsynonymous substitution rates in Adh-dup compared with Adh. Phylogenetic trees reconstructed by distance matrix and parsimony methods show that Sophophora and Scaptodrosophila subgenera diverged shortly after the separation from the Drosophila subgenus.

Electronic Resource

0090-6980

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

0090-6980

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

0034-9712

Sociology

ESTUDIOS

1432-1041

prazosin ; alphamethyldopa ; lipoprotein ; hypertension ; blood lipids ; serum parameters ; hydrochlorothiazide

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary The effects of prazosin and alphamethyldopa on blood lipids and lipoproteins were assessed in 20 patients with mild or moderate arterial hypertension. Parameters measured included serum cholesterol (CHO), triglycerides (TG), high density lipoprotein-cholesterol (HDL-CHO), insulin (I), glucose (G), and non-esterified fatty acids (NEFA). Prazosin — 4 mg/day for 6 weeks in hydrochlorothiazide-treated patients lowered blood pressure by 18.6/17.2 (systolic/diastolic pressure) mmHg. There was a significant decrease in CHO (−5.8%), in I (−16.5%), and in NEFA (−3.0%), and a significant increase in HDL-CHO (+15.5%). Alphamethyldopa 250–750 mg/day for 6 weeks in hydrochlorothiazide-treated patients lowered blood pressure by 18.8/14.6 (systolic/diastolic pressure) mmHg, accompanied by a non-significant decrease in CHO and TG, and significant increases in HDL-CHO (+10.3%), G (+8.5%) and NEFA (+6.4%). Thus, prazosin appears to have a more beneficial effect on blood lipids and lipoproteins than alphamethyldopa.

Electronic Resource

1432-1041

Dopamine ; Hypertension ; dopaminergic receptor ; insulin secretion ; cardiovascular system ; metoclopramide

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary Eleven patients with moderate to severe hypertension were pre-treated with oral labetalol 800–1200 mg/day for one week, prior to receiving two IV infusions of dopamine 1–3 μg/kg/min each of 30 min each, before and after the IV bolus injection of metoclopramide 30 mg. There were washout periods before and after the metoclopramide administration. Dopamine induced a significant decrease of blood pressure from 172/104 to 153/94 mm Hg without altering heart rate, and it increased the plasma insulin level from 8.3 to 12.1 μU·ml−1. Metoclopramide did not itself affect blood pressure or plasma insulin, but it did block the hypotensive response and rise in plasma insulin due to dopamine. We conclude that the pharmacological actions of intravenous dopamine on the cardiovascular system and on insulin secretion may be mediated by dopaminergic receptor stimulation.

Electronic Resource

1432-1041

Hydralazine ; clonidine ; dose-response curve ; cold-pressor test ; urinary noradrenaline excretion rate

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary Six patients with arterial hypertension were studied in hospital. They were given hydralazine iv in increasing doses, (2 mg, 3 mg, 5 mg, 6 mg, 10 mg) every 15 min, until the blood pressure was normal or side effects were encountered. Clonidine 150–600 µg/day was administered orally. Dose-blood pressure and heart rate-response curves to hydralazine and cold pressor test were performed when the patients were not taking drugs and after one week of clonidine administration; the urine noradrenaline excretion rate was also measured. The maximal iv dose of hydralazine reduced mean blood pressure from 133.7±7.54 (mean ± SEM) to 118.5±5.84 mm Hg (P〈0.05) and increased heart rate from 77.3±2.88 to 102.2±4.36 beats/min (P〈0.001). Clonidine decreased mean blood pressure from 133.7±7.54 to 116.8±7.75 mm Hg (P〈0.001) and heart rate from 77.3±2.88 to 63.8±4.91 beats/min (P〈0.001). During administration of maximal intravenous doses of hydralazine to patients treated with oral clonidine, mean blood pressure decreased from 116.8±7.75 to 98.4±3.61 mm Hg (P〈0.001) and heart rate increased from 63.8±4.91 to 76.0±5.54 beats/min (P〈0.001). The heart rate response to hydralazine was dose-related and the dose-response curve was shifted to the right by clonidine. The increase in mean blood pressure induced by the cold pressor test was significantly attenuated by clonidine (P〈0.05). Clonidine decreased significantly the urine noradrenaline excretion rate from 43.78±9.31 to 13.66±3.65 µg/24 hr (P〈0.05).

Electronic Resource

1432-1041

guanfacine ; hydrallazine ; hypertension ; sympathetic nervous activity ; plasma renin activity ; cardiac and systemic haemodynamics ; blood pressure ; limb blood flow ; limb vascular resistance

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary The effect of guanfacine and hydrallazine on cardiovascular haemodynamics and on sympathetic nervous activity has been studied in 16 patients with essential hypertension. Two groups of patients were investigated: in Group A guanfacine brought the blood pressure back to normal (diastolic blood pressure ⩽90 mmHg), and in Group B diastolic blood pressure was 〉 90 mmHg and required the addition of hydrallazine. Guanfacine significantly decreased heart rate, plasma renin activity and urinary excretion of noradrenaline, without altering cardiac contractility. In Group B, guanfacine 2 to 6 mg/day produced a significant decrease in blood pressure from 178.7/112.4 to 164.4/102.9 mmHg and in heart rate from 77.1 to 62.7 beats/min after 4 weeks of treatment. Guanfacine did not significantly alter preejection period, cardiac output or total peripheral resistance. Hydrallazine 50 to 300 mg/day caused a further reduction in blood pressure from 164.4/102.9 to 150.7/90.2 mmHg and an increase in heart rate from 62.7 to 72.1 beats/min. Limb blood flow was increased from 4.55 to 5.93 ml/100 g/min and limb vascular resistance was decreased from 39.55 to 23.6 mmHg 100 g·min/ml. Hydrallazine also caused a slight increase in plasma renin activity and urinary excretion of noradrenaline. It is concluded that guanfacine is a useful agent to block a hydrallazine-induced increase in sympathetic nervous activity.

Electronic Resource

1432-1041

clonidine ; minoxidil ; hypertension ; sympathetic nervous activity ; plasma renin activity ; cardiovascular responses

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary The effect of clonidine and minoxidil on sympathetic nervous activity has been studied in 10 patients with accelerated or resistant hypertension. Clonidine 150 to 900 µg/day caused a significant decrease in blood pressure of 18.6 mm Hg, of heart rate 16.4 beats/min, or plasma renin activity 1.13 ng/ml·h, and of urinary noradrenaline excretion 11.55 µg/day, and a significant lengthening of the pre-ejection period of 12.4 ms. Minoxidil 5 to 22.5 mg/day caused a further significant decrease in blood pressure of 24.2 mm Hg, and significant increases in heart rate 8.2 beats/min, plasma renin activity 1.68 ng/ml·h, and of urinary noradrenaline excretion 5.0 µg/day, and a significant shortening of the pre-ejection period of 20.6 ms. Neither clonidine nor minoxidil altered plasma dopamine β-hydroxylase activity or the cardiovascular responses to treadmill exercise. It is concluded that clonidine is a useful alternative agent to block a minoxidil-induced increase in sympathetic nervous activity.

Electronic Resource

1432-2242

Heat shock resistance ; Breeding temperature ; Crowding ; Drosophila subobscura

Springer Online Journal Archives 1860-2000

Biology

Summary Survival time following a high temperature shock of Drosophila subobscura adults in dry air has shown great variability. This experimental condition involved desiccation as the first cause of death. Here survival is studied under saturation humidity, so that the mortality may be imputed only to thermic stress. We analyze the influence of culture temperature and crowding on resistance for different sex and age of the adults. The results show strong influences of these environmental factors on heat shock resistance and show interactions with the age and sex of the adults. We suggest that these facts could be due to acclimatization and/or to adaptation. The acclimatization would occur during development and would affect physiological processes related to aging of the flies. The adaptation would take place for selection, acting through differential mortality before the heat shock. Of course, other processes could be significant. Whatever the causal explanation, it will be necessary in any future research related with heat shock resistance to take these factors into account.

Electronic Resource

1432-2242

Heat shock resistance ; Indirect selection ; Laboratory population evolution ; Drosophila sub-obscura

Springer Online Journal Archives 1860-2000

Biology

Summary We have carried out two equivalent selection experiments to increase and decrease heat shock resistance of Drosophila subobscura adults, using an indirect selection method that avoids excessive consanguinity. Heat shock was 33±0.5 °C at saturation humidity. Control lines showed a rapid change of the physiological trait as a consequence of laboratory culture conditions, expressed as a decrease both in heat shock resistance and in the initial population variability for heat shock resistance. Thus, this reduction of variability seems to consist in the loss of those combinations of genes that confer high resistance to heat shock. After eight generations of selection, the selected lines were differentiated from their respective control lines, and the selection response obtained was similar in “resistant” and “sensitive” lines. Differences in survival of progeny of reciprocal crosses between selected lines suggest that inheritance of heat resistance may depend in part on the origin of egg cytoplasm.

Electronic Resource

1573-6857

Heat shock resistance ; artificial selection ; chromosomal-inversion and enzymatic polymorphisms ; Drosophila subobscura

Springer Online Journal Archives 1860-2000

Biology

Abstract Two replicate selection experiments to increase and decrease heat shock resistance of Drosophila subobscura adults were carried out maintaining control lines. In the present paper, the chromosomal-inversion and enzymatic polymorphism variation with selection is analyzed. The results indicate an erratic variation of chromosomal arrangement frequencies for practically all the chromosomes in the selected lines, showing a loss of the less frequent arrangements especially in sensitive lines. Only the A chromosome and the O+4 arrangement show a behaviour that may not be due to random effects, which points to the possible existence of heat shock factor(s) in these chromosomes. Similarly, an erratic variation of allele frequencies is observed for all the enzymes studied (Aph, Pept-1) except for the Hk-1 enzyme. We cannot establish the possible participation of this locus in heat shock resistance from the results obtained up to now. A significant decrease in heterozygosity is detected in sensitive lines from chromosomal-inversion polymorphism.

Electronic Resource

1573-8477

D. subobscura ; D. obscura ; quantitative traits ; clines ; colonization

Springer Online Journal Archives 1860-2000

Biology

Summary Drosophila subobscura has recently colonized the American continent and is an excellent model for studying evolution in action. Previous analyses have shown that these colonizing populations have significant latitudinal clines for the frequencies of some chromosomal arrangements that parallel those clines found in the Old World. These results strongly suggest that this polymorphism is adaptive. In the present study, significant latitudinal clines for continuous morphometric variables (flies are larger in the north) have been detected in Old World populations ofD. subobscura. The adaptive nature of these clines is reinforced by the fact that parallel latitudinal clines for body size have also been detected inDrosophila obscura, a closely related sympatric species, as well as previously in otherDrosophila. On the other hand, no significant latitudinal clines for continuous morphometric traits, not even when using an overall size index, have been detected in colonizing populations ofD. subobscura. This is a rather surprising result given the number of generations that have elapsed since the species was detected in America and given that significant clines in chromosomal inversions are already established. Thus, the adaptive response of quantitative morphometric variables is not as rapid as that found for chromosomal inversions. Nevertheless, canonical correlation analysis suggests that significant latitudinal clines for body size might soon be detected in the American continent. The results obtained here are included in a projected time series with the aim of documenting size evolution in action.

Electronic Resource