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Biomedical subjects

A Soler

Publications and source records attributed to A Soler.

At least 19 recordsLinked to original sources
PubMed2003

Ion regulation in the different life stages of Trypanosoma cruzi.

Different ion and pH regulation mechanisms have been detected in the three main life stages of Trypanosoma cruzi: epimastigote, metacyclic trypomastigote and amastigote. Treatment with amiloride showed that the Na(+)/H(+) exchanger participated in all three forms. The Na(+)/K(+) ATPase exchanger appeared to be more active in the epimastigote than in the other forms. V-H(+)-ATPase inhibitors revealed the activity of this regulatory mechanism in the amastigote and epimastigote forms, while treatment with oligomycin only affected the amastigotes. The HCO(-)(3)/Cl(-) exchanger was found in all stages as well as in the intracellular pH-regulatory mechanism after abrupt basification. We deduce that ion regulation in T. cruzi is a complex process and depends upon the precise stage of the cell cycle of the parasite. It would seem to be an important mechanism, allowing the parasite to adapt to the changing environmental conditions within which it develops.

Animals↗
PubMed2003

Microscopic observation of particle reduction in slaughterhouse wastewater by coagulation-flocculation using ferric sulphate as coagulant and different coagulant aids.

A coagulation-flocculation treatment has been applied to a slaughterhouse liquid effluent, using ferric sulphate as coagulant and activated silica, powdered activated carbon, cationic polyacrylamide, polyvinyl alcohol, polyacrylic acid and anionic polyacrylamide as coagulant aids in order to improve the settling time. Once the optimal conditions had been established (speed and time of stirring during flocculation step, pH, coagulant and coagulant aid doses), the efficiency of the coagulation-flocculation process was studied by comparing the particle size distribution before and after the addition of the coagulant. When ferric sulphate was used without the coagulant aids, particle removal efficiency varied with size, although overall efficiency was quite substantial (87%). The use of coagulant aids improved the removal efficiency, except in the case of activated silica, when it fell to 78%. In all other cases removal efficiency values between 93% (for polyvinyl alcohol) and 99% (for anionic polyacrylamide) were reached.

Abattoirs↗
PubMed2002

Nutrient removal and sludge production in the coagulation-flocculation process.

Nutrient removal and sludge production in the coagulation-flocculation process, applied to a slaughterhouse effluent, have been studied. Fe2(SO4)3, Al2(SO4)3 and polyaluminium chloride were used as coagulants. Inorganic products were used as coagulant aids: activated silica, powdered activated carbon and precipitated calcium carbonate and synthetic polyelectrolytes: cationic polyacrylamide, polyacrilic acid, anionic polyacrylamide and polyvinyl alcohol. Performances were measured under optimum conditions for the products used. They were found after studying the different variables which influence the process. Phosphorus removal is very high (approximately 100% for the orthophosphate and between 98.93% and 99.90% for the total phosphorus). Ammonia nitrogen removal is very low although appreciable performances are observed for albuminoid nitrogen (73.9-88.77%). The use of coagulant aids reduces the volume of the sludge produced up to 41.6%.

Abattoirs↗
PubMed2002

Sulphur isotopes as tracers of the influence of potash mining in groundwater salinisation in the Llobregat Basin (NE Spain).

Conventional chemical data for spring and river waters are presented together with sulphur isotopic data for dissolved sulphate to elucidate the source of water salinisation in the middle section of the Llobregat River. As dilution processes do not affect sulphur isotopic composition, the analysis of delta34S of dissolved sulphate in waters provides an excellent tool for quantifying the environmental impact caused by the mining activity existing in the area. The delta34S of dissolved sulphate from mining effluents and saline springs unrelated to mining activity was analysed. The results obtained range from + 18 per thousand to + 20 per thousand (VCDT) for mining effluents and from + 10 per thousand to + 14 per thousand (VCDT) for natural saline springs. These values are in accordance with the pattern of sulphur isotopic composition of sulphates from the evaporite materials of this area. This distinctive isotopic composition has allowed us to determine the origin of salinity in those cases in which chemical features are not conclusive. In addition, two fertilisers widely used in the studied area are chemically and isotopically characterised and their contribution to groundwater salinisation is assessed.

Environmental Monitoring↗
PubMed2001

Mitochondrial involvement in antiretroviral therapy-related lipodystrophy.

OBJECTIVES: The management of HIV infection has greatly improved during recent years essentially because of the appearance of new antiretroviral drugs. Highly active antiretroviral therapy (HAART) has achieved important reductions of viraemia and significant recoveries of CD4(+) cell counts in HIV-infected patients. Nonetheless, cases of HIV-infected individuals experiencing lipodystrophy (LD) are being increasingly reported. The purpose of this work was to analyse whether the presence of mitochondrial abnormalities is a frequent feature in LD, since we previously detected mitochondrial abnormalities in an HIV-patient. The second main objective was to study whether LD could be associated with a specific drug. DESIGN: Seven HIV patients presenting LD and five HIV non-LD controls participated in the study. LD patients met the following criteria: (1) LD was their only clinical abnormality, (2) LD was clinically relevant, (3) compliance with antiretroviral treatment was higher than 90% and (4) patients did not have personal or familial history suggestive of mitochondrial disease or neuromuscular disorder. METHODS: Histological stainings, histo-enzymatic reactions, enzymatic and respiratory activities of mitochondrial respiratory chain complexes, and mitochondrial DNA (mtDNA) depletion and rearrangements were examined on muscle mitochondria. RESULTS: Structural muscle abnormalities, mitochondrial respiratory chain dysfunction or mtDNA deletions were detected in all HIV lipodystrophic patients. CONCLUSIONS: The mitochondrial abnormalities found suggest that mitochondrial dysfunction could play a role in the development of antiretroviral therapy-related lipodystrophy.

Adult↗
PubMed2001

Salt stress increases the Ca2+-independent phosphoenolpyruvate carboxylase kinase activity in Sorghum leaves.

In C4 plants, the photosynthetic enzyme phosphoenolpyruvate carboxylase (PEPCase; EC 4.1.1.31) is subjected to a phosphorylation process via the light-dependent up-regulation of a Ca2+-independent PEPCase-kinase. The present work aimed to study the effect of salt stress on PEPCase phosphorylation in Sorghum vulgare Pers. leaves. The growth of salt-treated plants was reduced compared with that of the control plants. PEPCase activity modestly increased (around 20-40%) whereas PEPCase phosphorylation was markedly enhanced, on a protein basis, in extracts from illuminated leaves. The enhanced protein kinase activity was found to display a low molecular mass in the range 32-35 kDa, to be independent of Ca2+ and to be up-regulated by light. Furthermore, up-regulation was blocked in vivo by the cytosolic protein synthesis inhibitor cycloheximide. Collectively, these data demonstrated that salinity stress altered the Ca2+-independent PEPCase-kinase, presumably by increasing the mesophyll content of the enzyme. Potassium chloride, but not abscisic acid, mimicked the effect of NaCl on PEPCase-kinase activity.

Abscisic Acid↗
PubMed2001

An antifungal exo-alpha-1,3-glucanase (AGN13.1) from the biocontrol fungus Trichoderma harzianum.

Trichoderma harzianum secretes alpha-1,3-glucanases when it is grown on polysaccharides, fungal cell walls, or autoclaved mycelium as a carbon source (simulated antagonistic conditions). We have purified and characterized one of these enzymes, named AGN13.1. The enzyme was monomeric and slightly basic. AGN13.1 was an exo-type alpha-1,3-glucanase and showed lytic and antifungal activity against fungal plant pathogens. Northern and Western analyses indicated that AGN13.1 is induced by conditions that simulated antagonism. We propose that AGN13.1 contributes to the antagonistic response of T. harzianum.

Antibiosis↗
PubMed2000

An hydroalcoholic extract of curcuma longa lowers the apo B/apo A ratio. Implications for atherogenesis prevention.

It is generally accepted that free-radical induced blood lipid peroxidation and especially peroxidized LDL play a central role in the pathogenesis of atherosclerosis and related cardiovascular disease. Moreover, recent research highlights the key contribution of apolipoprotein B (apo B) to atherogenesis as the main inductor of one of its earlier steps, i.e. macrophage proliferation. This has led us to investigate the apo B response to a very effective phenolic lipid-antioxidant, namely an hydroalcoholic extract of Curcuma longa, which according to our previous work does not show any toxic effects and decreases the levels of blood lipid peroxides, oxidized lipoproteins and fibrinogen. The present study shows that a daily oral administration of the extract decreases significantly the LDL and apo B and increases the HDL and apo A of healthy subjects. This and recent data on the increased anti-atherogenic action of the physiological antioxidant tocopherol in the presence of phenolic co-antioxidants (which eliminate the tocopheroxyl radical), justifies planned clinical research to test the usefulness of the curcuma extract as a co-antioxidant complement to standard treatments to prevent or retard atherosclerosis.

Adult↗
PubMed2000

[Changes in emergency visits of patients infected by human immunodeficiency virus since the widespread use of protease inhibitors].

OBJECTIVE: To evaluate the changes in the urgent visits made by HIV+ patients after generalisation of the protease inhibitors. PATIENTS AND METHODS: Comparison on the visits made during a period prior to and after use of protease inhibitor. RESULTS: After the generalisation of the protease inhibitors the visits rate decreased, the motives for consulting with the physician and complementary examinations changed, invasive therapeutic procedures, admissions from urgencies and death rates decreased. CONCLUSIONS: The protease inhibitors have changed the urgent visits profile of HIV+ patients.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Paternal isodisomy 13 in a normal newborn infant after trisomy rescue evidenced by prenatal diagnosis.

Maternal and paternal uniparental disomy of chromosome 13 have been associated with normal phenotypes. We report on a new case of paternal isodisomy 13 in a phenotypically normal girl. Prenatal diagnosis had shown a 46,XX,-13,der(13;13) karyotype in chorionic villi and a 45,XX,der(13;13) karyotype in amniocytes and fetal blood. Molecular studies demonstrated that the de novo der(13;13) was an isochromosome 13 of paternal origin. This observation supports the lack of imprinting effects on chromosome 13 and trisomy rescue as a mechanism leading to uniparental disomy in cases involving isochromosomes.

Chorionic Villi Sampling↗
PubMed2000

SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite.

Yp-specific sequences, including the testicular determinant gene SRY, have been detected and located in a 46,XX true hermaphrodite individual, using PCR amplification and fluorescent in situ hybridization (FISH). Among different Y chromosome loci tested, it was only possible to detect Yp sequences. The Y-centromere and Yq sequences were absent. Unexpectedly, the Y fragment was translocated to the long arm of one of the X chromosomes, at the Xq28 level, and the derivative (X) chromosome of the patient lacked q-telomeric sequences. To our knowledge, this is the first Yp/Xq translocation reported. The coexistence of testicular and ovarian tissue in the patient may have arisen by differential inactivation of the Y-bearing X chromosome, in which Xq telomeric sequences are missing. The possible origin of the Yp/Xq translocation, during paternal meiosis or in somatic paternal cells, is discussed.

Adult↗
PubMed2000

Neoplasia of plasma cells with atypical presentation and infection by the human immunodeficiency virus. A presentation of two cases.

Neoplasia of plasma cells acquires special clinical characteristics in patients infected by human immunodeficiency virus (HIV). These patients are much younger at the time of diagnosis, and when they are compared with the general population they show an atypical clinical evolution, with a greater frequency of solitary plasmacytomas, less evidence of a monoclonal plasmatic component, or greater aggressiveness of the neoplastic process. This paper provides the most significant data on two patients infected by HIV and diagnosed for plasma cell neoplasia. Recent pathogenetic hypotheses for plasma cell neoplasias that include immune alterations, chronic viral infections, and hyperexpression of cytokines exist in patients infected by HIV, and this could suggest that this type of neoplasia is another malignant haematological process associated with AIDS.

Adult↗
PubMed1999

Stimulation of tyrosine phosphorylation by progesterone and its 11-OH derivatives: dissection of a Ca(2+)-dependent and a Ca(2+)-independent mechanism.

Progesterone has previously been shown to exert non-genomic effects on human spermatozoa by opening plasma membrane ion channels and by stimulating protein tyrosine phosphorylation. Here we examined how these two activities are influenced by 11-hydroxyl substitution of the steroid molecule either in the alpha- or in the beta-configuration. Both the 11alpha-OH and the 11beta-OH derivatives of progesterone were more effective than progesterone in stimulating tyrosine phosphorylation, although 11alpha-OH-progesterone was a markedly weaker Ca(2+)-influx inducing agonist than the other two steroids. In Ca(2+)-containing medium, the agonist activity of the 11alpha-OH derivative was weaker than that of the 11beta-OH derivative, and it was completely abolished by genistein, whereas that of progesterone and its 11beta-OH derivative was inhibited only partly by this drug. In contrast, when applied in Ca(2+)-free medium, the 11alpha-OH derivative was the strongest of the three agonists tested, and the effects of all the three steroids were completely abolished by genistein. These data show that the structural motifs of steroid molecules that are responsible for the stimulation of tyrosine phosphorylation are different from those mediating the steroid action on Ca2+ influx through plasma membrane channels. The synthesis of selective agonists of both activities may lead to the development of new pharmacological agents to be used in the treatment of steroid-dependent pathologies.

Calcium↗
PubMed1999

First-trimester biochemical markers for Down syndrome.

The value of maternal serum pregnancy-associated protein A (PAPP-A), free and total beta human chorionic gonadotrophin (fbetahCG, betahCG) and alpha-fetoprotein (AFP) in screening for Down syndrome (DS) in early pregnancy has been assessed. To evaluate the different biochemical markers, 32 DS pregnancies and 267 controls were used for AFP, betahCG and PAPP-A. A subgroup of those (17 DS and 136 controls) were used to evaluate fbetahCG. All analytes were determined in fresh serum samples. Our results give support to the feasibility of maternal serum levels of PAPP-A as the best biochemical marker for DS in the first trimester, and either betahCG or fbetahCG as the second marker. No differences were found between betahCG and fbetahCG distribution levels as expressed as MoMs in normal and DS pregnancies in this study.

Adult↗
PubMed1999

Changes in glucose transport and protein kinase Cbeta(2) in rat skeletal muscle induced by hyperglycaemia.

AIMS/HYPOTHESIS: We have previously reported that hyperglycaemia activates glucose transport in skeletal muscle by a Ca(2+)-dependent pathway, which is distinct from the insulin-signalling pathway. The aim of this study was to explain the signalling mechanism by which hyperglycaemia autoregulates glucose transport in skeletal muscle. METHODS: Isolated rat soleus muscle was incubated in the presence of various concentrations of glucose or 3-O-methylglucose and protein kinase C and phospholipase C inhibitors. Glucose transport activity, cell surface glucose transporter 1 and glucose transporter 4 content and protein kinase C translocation was determined. RESULTS: High concentrations of 3-O-methylglucose led to a concentration-dependent increase in [(3)H]-3-O-methylglucose transport in soleus muscle. Dantrolene, an inhibitor of Ca(2+) released from the sarcoplasmic reticulum, decreased the V(max) and the K(m) of the concentration-response curve. Protein kinase C inhibitors (H-7 and GF109203X) inhibited the stimulatory effect of high glucose concentrations on hexose transport, whereas glucose transport stimulated by insulin was unchanged. Incubation of muscle with glucose (25 mmol/l) and 3-O-methylglucose (25 mmol/l) led to a three fold gain in protein kinase Cbeta(2) in the total membrane fraction, whereas membrane content of protein kinase Calpha, beta(1), delta, epsilon and theta were unchanged. A short-term increase in the extracellular glucose concentration did not change cell surface recruitment of glucose transporter 1 or glucose transporter 4, as assessed by exofacial photolabelling with [(3)H]-ATB-BMPA bis-mannose. CONCLUSION/INTERPRETATION: Protein kinase Cbeta(2) is involved in a glucose-sensitive, Ca(2+)-dependent signalling pathway, which is possibly involved in the regulation of glucose transport in skeletal muscle. This glucose-dependent increase in 3-0-methylglucose transport is independent of glucose transporter 4 and glucose transporter 1 translocation to the plasma membrane and may involve modifications of cell surface glucose transporter activity.

3-O-Methylglucose↗
PubMed1999

Detection of beta-1,6-glucanase isozymes from Trichoderma strains in sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectrofocusing gels.

The filamentous fungus Trichoderma produces, under specific growth conditions, several extracellular fungal cell wall degrading enzymes, amongst them beta-1,6-glucanases. These enzymes seem to play an important role in the antagonistic action of Trichoderma against a wide range of fungal plant pathogens. In this report we describe two different methods for the specific detection of the activity of beta-1,6-glucanase isozymes in gels. After sodium dodecyl sulphate-polyacrylamide gel electrophoresis, beta-1,6-glucanase activity can be assayed in the gel by renaturation of the enzyme, incubation with an overlay agarose gel containing solubilized pustulan (a commercially available beta-1,6-glucan), followed by the staining of the agarose gel with Congo Red. In native isoelectrofocusing gels, as little as 1 mU can be detected after incubation with solubilized pustulan followed by a detection reaction of the released reducing sugars with 2,3,5-triphenyltetrazolium chloride. The latter technique has been successfully applied to the screening of beta-1,6-glucanase isozymes from different Trichoderma strains under different growth conditions.

Electrophoresis, Polyacrylamide Gel↗