Biomedical subjects

J Garrido

Publications and source records attributed to J Garrido.

At least 37 records · Page 2Linked to original sources

PubMed1999

Prospective comparison of therapeutical attitudes in hypertensive type 2 diabetic patients uncontrolled on monotherapy. A randomized trial: the EDICTA study.

OBJECTIVE: To compare the anti-hypertensive effect of combination therapy versus a single drug regimen schedule (dose-titration or switching to a different drug class) in type 2 diabetic hypertensive patients with inadequate blood pressure (BP) control on monotherapy. DESIGN: Prospective, randomized, open-fashion, parallel study of two therapeutic strategies during an 8-week period. SETTING: Primary care centers in Spain. PARTICIPANTS: A total of 898 men and women with type 2 diabetes mellitus and hypertension, receiving antihypertensive treatment with one single drug and whose BP was > 140 and/or 90 mmHg. INTERVENTION: Patients were randomized to a fixed combination therapy (verapamil 180 mg plus trandolapril 2 mg; Knoll AG, Ludwigshafen, Germany) or continued on a single drug regimen, either increasing the dose of the current drug or switching to a different drug class. MAIN OUTCOME MEASURE: Absolute BP reduction in the two groups of treatment, and the percentage of normalized patients (< 140/90 mmHg) in each group. RESULTS: The diastolic BP (DBP) decrease (5.6 mmHg) was significantly greater in patients treated with combination therapy, compared to patients on monotherapy (2.9 mmHg). The decrease in systolic BP (SBP) was not significantly different (11.1 versus 10.0 mmHg). In addition, a significantly higher number of patients treated with combination therapy (82% versus 74%) reached diastolic BP normalization (< 90 mmHg). CONCLUSIONS: In type 2 hypertensive patients with uncontrolled BP despite anti-hypertensive monotherapy, the change to combination therapy was more effective in attaining DBP control than any monotherapy schedule (either increasing the dose or switching to another different drug class).

Aged↗

PubMed1999

Comparative study of the clinical efficacy of two different coumarin dosages in the management of arm lymphedema after treatment for breast cancer.

In a randomized, double-blind, parallel group study, we compared the clinical efficacy of coumarin 90 mg/day (Group A) with 135 mg/day (Group B) in 77 women (age 35-65 years) with lymphedema of the upper limb secondary to surgery and irradiation for treatment of breast cancer. During 12 months of coumarin therapy, the arm volume of lymphedema and a clinical score (degree of arm edema, heaviness, hardness, and neuralgia/dysesthesia) were determined. In both groups, the volume of arm lymphedema decreased (14.9% in Group A and 13.2% in Group B) (N.S.), the overall clinical score improved (12.9 +/- 4.3 to 5.7 +/- 3.5 in Group A and from 11.7 +/- 3.7 to 4.7 +/- 3.9 in Group B) (N.S.), and the overall efficacy of coumarin was similarly good or excellent (71.9% in Group A and 68.6% in Group B) (N.S.). Only mild to moderate side effects of drug therapy were recorded. Coumarin prevents a spontaneous trend toward an increase in arm lymphedema after treatment of breast cancer, decreases the severity of local symptoms, and overall improves the quality of life. No difference was found between the apparent benefits of coumarin at 90 mg/day compared with 135 mg/day.

Arm↗

PubMed1998

A major portion of synaptic basal lamina acetylcholinesterase is detached by high salt- and heparin-containing buffers from rat diaphragm muscle and Torpedo electric organ.

Collagen-tailed asymmetric acetylcholinesterase (AChE) forms are believed to be anchored to the synaptic basal lamina via electrostatic interactions involving proteoglycans. However, it was recently found that in avian and rat muscles, high ionic strength or polyanionic buffers could not detach AChE from cell-surface clusters and that these buffers solubilized intracellular non-junctional asymmetric AChE rather than synaptic forms of the enzyme. In the present study, asymmetric AChE forms were specifically solubilized by ionic buffers from synaptic basal lamina-enriched fractions, largely devoid of intracellular material, obtained from the electric organ of Torpedo californica and the end plate regions of rat diaphragm muscle. Furthermore, foci of AChE activity were seen to diminish in size, number, and staining intensity when the rat synaptic basal lamina-enriched preparations were treated with the extraction buffers. In the case of Torpedo, almost all the AChE activity was removed from the pure basal lamina sheets. We therefore conclude that a major portion of extracellular collagen-tailed AChE is extractable from rat and Torpedo synaptic basal lamina by high ionic strength and heparin buffers, although some non-extractable AChE activity remains associated with the junctional regions.

Acetylcholinesterase↗

PubMed1998

Relation between Fatty Acid Content and Its Evolution during Fermentation and Utilization of Free Amino Acids in Vacuum-Filtered Viura Must.

The activity of proteins that transport amino acids changes depending on the unsaturated residue which is introduced into the phospholipids of Saccharomycescerevisiae membrane. The aim of this study was to observe the influence of fatty acid content and its evolution during fermentation on the utilization of free amino acids in Vitis vinifera var. Viura must clarified by vacuum filtration. The results demonstrate that filtration of the must did not reduce the concentration of free amino acids, but it did reduce fatty acids, especially the unsaturateds. In the first half of fermentation (up to 50% sugar consumption), fatty acid utilization was different in each sample without involving an alteration in the uptake of amino acids. In the second half of fermentation (from 50% sugar consumption until the end of fermentation), the clarified sample had greater consumption of saturated fatty acids than unsaturated, in contrast to the control; this, along with other factors, produced a greater liberation of free amino acids in the filtered sample.

Journal Article↗

PubMed1998

Treatment of diastolic dysfunction in hypertensive patients without left ventricular hypertrophy.

The aim of this study was to evaluate the influence of verapamil SR 240 mg (V) and the combination amiloride 5 mg + hydrochlorothiazide 50 mg (AH) on diastolic dysfunction of hypertensive patients without left ventricular hypertrophy (LVH). Twenty-six hypertensive patients with diastolic dysfunction, normal systolic function and without LVH were included into a 2-week washout period and then randomised to a 6-month V or AH treatment. One blinded-to-treatment echocardiographist at baseline and at weeks 4, 12 and 24 assessed Doppler-echocardiography. Both V and AH, satisfactorily controlled blood pressure, but only V improved diastolic function shown by a tendency to reduce peak A and to increase peak E/A ratio, and by a significant reduction in deceleration time. After 24 weeks, V significantly reduced wall thickness in comparison with AH. These results need to be confirmed in a larger scale study.

Adult↗

PubMed1998

Endocytosis and MHC class II expression by human oviductal epithelium according to stage of the menstrual cycle.

The epithelium is the first barrier against pathogens invading the lumen of the human oviduct. Its expression of class II major histocompatibility complex (MHC class II) proteins suggests that it might play a role in antigen presentation during the local immune response. To study the role of the oviductal epithelium in antigen processing, its endocytic properties and MHC class II expression were examined. For assay of endocytosis, fluorescein isothiocyanate-labelled bovine serum albumin (BSA-FITC) or Escherichia coli (E. coli-FITC) was infused into the lumen. One-centimetre pieces of oviduct were incubated for 2 h and processed for fluorescence and confocal microscopy, and transmission electron microscopy. Incorporation into secretory and ciliated epithelial cells was observed, which was unrelated to the phase of the menstrual cycle. Small pieces of the organs were frozen and processed for immunohistochemistry. Most oviducts expressed MHC class II (HLA.DR) in the epithelium and in some cases this was coincident with endocytosis, but there was no statistically significant association between this expression and either endocytotic activity or the phase of the menstrual cycle. Results demonstrate that the epithelium of the human oviduct exhibits endocytic properties towards luminal soluble and particle antigens, which is not related either to MHC class II expression or to the phase of the menstrual cycle.

Adult↗

PubMed1997

Acetylcholinesterase promotes the aggregation of amyloid-beta-peptide fragments by forming a complex with the growing fibrils.

Acetylcholinesterase (AChE), an enzyme involved in the hydrolysis of the neurotransmitter acetylcholine, consistently colocalizes with the amyloid deposits characteristic of Alzheimer's disease and may contribute to the generation of amyloid proteins and/or physically affect fibril assembly. In order to identify the structural domains of the amyloid-beta-peptide (Abeta) involved in the aggregation induced by AChE, we have studied the effect of this cholinergic enzyme on Abeta peptide fragments of different sizes. AChE enhanced the aggregation of the Abeta(12-28) and Abeta(25-35) peptides but not of the Abeta(1-16) fragment. The inductive effect of AChE on the aggregation of Abeta(12-28) was abolished by the presence of either Abeta(1-16) or Abeta(9-21). The effect of the enzyme was also analysed using two different mutant fragments, possessing a low and the other a high capacity for fibrillogenesis. The fragments used were Abeta(12-28)Val18-->Ala and Abeta(12-28)Glu22-->Gln, respectively. AChE was able to promote the aggregation of these fragments in a very specific way and both mutant peptides were able to form amyloid fibrils, as revealed by negative staining under the electron microscope. Binding assays indicated that AChE was bound to Abeta(12-28), as well as to the Abeta(1-16) peptide. AChE was seen to form strong complexes with the Abeta(12-28) fibrils as such complexes stained positively for both thioflavine-T and AChE activity, were resistant to high ionic strength treatment, and were partially sensitive to detergents, suggesting that hydrophobic interactions may play a role in the stabilization of the AChE-Abeta complex. Our results suggest that such amyloid-AChE complexes are formed when AChE interacts with the growing amyloid fibrils and accelerates the assembly of Abeta peptides. This is consistent with the fact that AChE is known to be present within Abeta deposits including the pre-amyloid diffuse and mature senile plaques found in Alzheimer's brain.

Acetylcholinesterase↗

PubMed1997

A monoclonal antibody against acetylcholinesterase inhibits the formation of amyloid fibrils induced by the enzyme.

A monoclonal antibody (mAb) 25B1 directed against fetal bovine-serum acetylcholinesterase (FBS AChE) was used to examine the ability of the cholinergic enzyme to promote the assembly of amyloid-beta peptides (A beta) into Alzheimerś fibrils. This mAb binds to the peripheral anionic site of the enzyme and allosterically inhibits catalytic activity of FBS AChE. Several techniques, including thioflavine-T fluorescence, turbidity, and negative-staining at the electron microscopy level, were used to assess amyloid formation. Inhibition of amyloid formation was dependent on the molar ratio AChE:mAb 25B1, and at least 50% of the inhibition of the AChE promoting effect occurs at a molar ratio similar to that required for inhibition of the esterase activity. Our results suggest that mAb 25B1 inhibits the promotion of the amyloid fibril formation triggered by AChE by affecting the lag period of the A beta aggregation process.

Acetylcholinesterase↗

PubMed1997

Chromatographic analysis of imazalil and carbendazim in fruits. Method validation and residue monitoring program 1995.

A single and simple procedure for the determination of both carbendazim and imazalil is described. The proposed analytical methodology is based on a liquid-liquid extraction with ethyl acetate and further analysis with HPLC-UV in the case of carbendazim, and GC-nitrogen-phosphorus detection in the case of imazalil. Detection levels have been 0.01 mg/kg for carbendazim and 0.005 mg/kg for imazalil. Recoveries have been no less than 77% for carbendazim and 92% for imazalil. The method has been validated with fortified samples at different concentration levels. Different confirmation criteria have been studied and applied in routine analysis. The analytical procedure proposed has been applied to the analysis of 200 fruit samples belonging to the Residue Monitoring of Hygiene Food Program 1995 of the Spanish Ministry of Health, which has been performed in our laboratory. The results obtained have confirmed the viability of the method in routine analysis for these pesticides. A first evaluation of the presence of residues of both fungicides in fruits produced in Spain has been made.

Acetates↗

PubMed1996

Tau-like proteins associated with centrosomes in cultured cells.

The subcellular association of tau-like proteins with centrosomes in cultured cell lines and its effects in nucleating microtubule assembly were analyzed using biochemical and immunocytochemical approaches. Tau proteins, major components of microtubules, appear to be tightly associated with actin filaments in a variety of cell lines, while in pathological conditions of neurons, they are part of paired helical filaments found in Alzheimer's disease. Different studies suggest that, in addition to tau interactions with the components of the cytoskeletal network, tau polypeptides appear to be associated with highly structured cellular elements, in both interphase and mitotic cells. An in-depth analysis of tau subcellular distribution us- ing different polyclonal and monoclonal antibodies showed colocalization of tau-like components with centrosomes in interphase cells of the human Huh-7 hepatoma, in SW-13 adenocarcinoma, and in normal human fibroblasts. Tau associated with centrosomes in mitotic Huh-7 cells was also identified. However, antibodies against the tau binding repeats did not stain centrosomes. A set of different tau isoforms was also identified by Western blot analysis on isolated centrosomal preparations from Huh-7 cells, obtained by differential centrifugation through sucrose gradients. Microtubule nucleation in vitro over isolated centrosomes was inhibited by both the polyclonal antibody against native tau and an antibody to the N-terminal tau sequence, as revealed by immunofluorescence analysis and assembly kinetics experiments. The antibody TRS1.2 against the fragment containing the first binding repeat on tau did not affect nucleation. These studies allowed us to characterize tau association with the isolated centrosomal preparation and its involvement in microtubule assembly nucleated over centrosomes, thus suggesting possible structural and functional roles for these interactions.

Cells, Cultured↗

PubMed1996

Laminin inhibits amyloid-beta-peptide fibrillation.

Laminin, an important extracellular matrix component is induced by brain injury and colocalizes with amyloid-beta-peptide (A beta) deposits in Alzheimer brains. We report here that laminin inhibits amyloid fibril formation as determined by thioflavin T fluorescence spectroscopy and electron microscopic examination. The inhibition of amyloid formation by laminin was concentration dependent and was observed at a laminin concentration of 300 nM, corresponding to a laminin/A beta protein molar ratio of 1:800. The potential effect of laminin, may prove important to inhibit A beta fibrillogenesis in vivo, specifically at the level of cerebral blood vessels.

Amyloid beta-Peptides↗

PubMed1996

Improved catalytic performance of a 2-haloacid dehalogenase from Azotobacter sp. by ion-exchange immobilisation.

The stability and catalytic efficacy of the L-2-haloacid dehalogenase isolated from Azotobacter sp. RC26 were studied after immobilisation on a DEAE Sephacel solid matrix. While the optimum temperature for the soluble dehalogenase falls in the range of 30-40 degrees C, the activity of the immobilised enzyme shows a four-fold increase at 60 degree C. Immobilisation on a plug-flow bioreactor extends the range of usable substrate concentration. The improved catalytic characteristics after immobilisation of the haloacid dehalogenase may be relevant for its possible utilization in biotechnological applications ranging from waste treatment to synthesis of stereoisomers.

Azotobacter↗

PubMed1996

Abnormal development of the locomotor activity in yellow larvae of Drosophila: a cuticular defect?

The yellow (y) mutation of Drosophila melanogaster affects the development of behavior and morphology. We have analyzed some behavioral and morphological parameters during the development of y mutants. Wild-type third instar larvae move in straighter paths than larvae of the same age homozygous for the y mutation. At 96 h of age, the tracks of y larvae have 10 times as many loops as tracks of wild-type larvae, and at 120 h of age, y larvae show bending behavior about 2.5 times more frequently than do wild-type. Consequently, they do not disperse as much as wild-type larvae. Concomitant with the behavioral changes, the larvae present a defect in the morphology of large chaetae in the larval denticle belts, particularly of 2nd and 3rd instars, both with light and scanning electron microscopes. These results suggest that a cuticular defect is probably involved in the abnormal locomotor activity observed in y larvae of Drosophila melanogaster.

Animals↗

PubMed1996

Menstrual history as a determinant of current bone density in young hirsute women.

There is evidence that bone mass is influenced by estrogen, declining in situations characterized by a decrease in the production of this hormone. Usually, amenorrhea and oligomenorrhea are associated with a state of hypoestrogenism, and both situations are frequent in hirsute patients. The aim of the present study was to analyze the relationship between bone mass and menstrual cyclicity in hirsute women. A total of 52 nulliparous women complaining of hirsutism in various degrees with associated oligomenorrhea/amenorrhea (OA) in 27 cases and eumenorrhea in 25 were included in this study. Basal serum levels of follicle-stimulating hormone (FSH), luteinzing hormone (LH), estradiol-17beta (E2), prolactin (PRL), testosterone (T), androstenedione (A4) dehydroepiandrosterone sulfate (DHEAS), 17-hydroxyprogesterone (OHP), and SHBG were determined, and the area under the curve (AUC) for E2 was plotted. Bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry (DEXA). The mean age for eumenorrheic patients was 26 years (range, 17 to 31), and for OA patients, 24 (range, 16 to 29). Both groups had similar Ferriman-Gallwey scores. Basal levels of PRL, LH, FSH, E2, T, A4, OHP, and DHEAS were similar for eumenorrheic and OA patients. The AUC for E2 was significantly higher for eumenorrheic patients, and DEXA at the lumbar spine demonstrated a significant difference between eumenorrheic (1.222 +/- 0.240 g/cm2) and OA (1.016 +/- 0.108 g/cm2) hirsute women (P < .01). In conclusion, OA, due to a relative hypoestrogenism, may be correlated with osteopenia in young hirsute women.

Absorptiometry, Photon↗

PubMed1996

Acetylcholinesterase accelerates assembly of amyloid-beta-peptides into Alzheimer's fibrils: possible role of the peripheral site of the enzyme.

Acetylcholinesterase (AChE), an important component of cholinergic synapses, colocalizes with amyloid-beta peptide (A beta) deposits of Alzheimer's brain. We report here that bovine brain AChE, as well as the human and mouse recombinant enzyme, accelerates amyloid formation from wild-type A beta and a mutant A beta peptide, which alone produces few amyloid-like fibrils. The action of AChE was independent of the subunit array of the enzyme, was not affected by edrophonium, an active site inhibitor, but it was affected by propidium, a peripheral anionic binding site ligand. Butyrylcholinesterase, an enzyme that lacks the peripheral site, did not affect amyloid formation. Furthermore, AChE is a potent amyloid-promoting factor when compared with other A beta-associated proteins. Thus, in addition to its role in cholinergic synapses, AChE may function by accelerating A beta formation and could play a role during amyloid deposition in Alzheimer's brain.

Acetylcholinesterase↗

PubMed1996

Increase in prostaglandin bioavailability precedes the onset of human parturition.

The traditional paradigm that prostaglandins (PGS) are of central importance in the initiation of labor has been challenged. A group of investigators has recently reported that the amniotic fluid concentrations of PGE(2) and PGF(2 alpha) increase only late in the course of labor implying that "the accumulation of prostaglandins in amniotic fluid is an after-effect of labor and not indicative of a role of these compounds in the initiation of human parturition." The present study was conducted to determine whether amniotic fluid prostaglandin concentrations increase prior to the onset of human labor, the central question in this controversy. Three amniocenteses were performed in 17 women with intrahepatic cholestasis of pregnancy -- the first two prior to the onset of labor and the third during early spontaneous labor. PGE(2) and PGF(2 alpha) were measured with sensitive and specific radioimmunoassays. Amniotic fluid concentrations of PGE(2) and PGF(2 alpha) increased prior to the onset of spontaneous labor. An additional increase in the concentrations of PGE(2) and PGF(2 alpha) was found in samples obtained in early labor. We conclude that an increase in prostaglandin bioavailability precedes the onset of spontaneous human parturition.

Amniocentesis↗

PubMed1996

ATP-diphosphophydrolase activity in rat heart tissue.

Extracellular nucleotides interact with specific receptors on the cell surface and are locally metabolized by ecto-nucleotidases. Biochemical characterization of the ATPase and ADPase activities detected in rat heart sarcolemma, under conditions where mitochondrial ATPase and adenylate kinase were blocked, supports our proposal that both activities correspond to a single enzyme, known as ATP-diphosphohydrolase or apyrase. The physiological function of this enzyme could be dephosphorylation of the nucleotides present in the interstitial heart compartment acting together with 5'-nucleotidase. Both hydrolytic activities have similarities in: sarcolemma localization, bivalent metal ion dependence, optimum pH, effect of several amino acid residue modifiers, competitive inhibition of nucleotide analogs, and broad nucleoside di-and triphosphate specificity. The ATPase activity could not be separated from the ADPase either through isoelectrofocusing or electrophoresis under acid conditions.

Amino Acids↗

PubMed1995

Acetylcholinesterase, a senile plaque component, affects the fibrillogenesis of amyloid-beta-peptides.

Acetylcholinesterase (AChE) colocalizes with amyloid-beta peptide (A beta) deposits present in the brain of Alzheimer's patients. Recent studies showed that A beta 1-40 can adopt two different conformational states in solution (an amyloidogenic conformer, A beta ac, and a non-amyloidogenic conformer, A beta nac) which have distinct abilities to form amyloid fibrils. We report here that AChE binds A beta nac and accelerates amyloid formation by the same peptide. No such effect was observed with A beta ac, the amyloidogenic conformer, suggesting that AChE acts as a 'pathological chaperone' inducing a conformational transition from A beta nac into A beta ac in vitro.

Acetylcholinesterase↗