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C Blasco

Publications and source records attributed to C Blasco.

18 recordsLinked to original sources
PubMed2004

Ontogeny of the antennal glands in the crayfish Astacus leptodactylus (Crustacea, Decapoda): anatomical and cell differentiation.

The ontogeny of the antennal glands was studied during the embryonic and post-embryonic development of Astacus leptodactylus. The future glands arising from undifferentiated columnar cells were detectable at the metanauplius stage EI 150 microm (EI: eye index; approximately 440 microm at hatching). The tubule and labyrinth differentiated in embryos at EI 190 microm, and the bladder and coelomosac at EI 250 microm. At EI 350 microm, the tubule lengthened and divided into proximal and distal sub-regions. In later stages, the gland retained the same morpho-anatomy but the differentiation and size of each part increased. The cells of the coelomosac displayed the cytological features of podocytes in late embryonic development at EI 440 microm. Only small apical microvilli and a few mitochondria were observable in the labyrinth cells at EI 250 microm; by EI 440 microm, these cells presented well-shaped apical microvilli, formed bodies, basal infoldings and mitochondria. In the cells of the tubules and bladder, mitochondria and basal infoldings occurred at EI 440 microm and EI 250 microm, respectively. The differentiation of the tubules and bladder cells suggested that they were involved in active transport at EI 440 microm. Following hatching, the differentiation of the cells and the size of the glands increased. The ontogeny of the antennal glands thus starts in early embryos, the specific cellular functional features being differentiated in the various parts of the glands by EI 440 microm. The antennal glands are probably functional just before hatching, i.e., before the juveniles are confronted with the low osmolality of freshwater.

Animals↗
PubMed2004

Determination of organochlorine pesticide residues in honey from the central zone of Portugal and the Valencian community of Spain.

In this study nine organochlorine pesticide residues (alpha-, beta-, and gamma-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), aldrin, p,p'-DDE, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in forty nine samples of honey collected from markets of Portugal and Spain during 2001 and 2002, respectively, were evaluated. For this evaluation, three analytical procedures were studied. The analytical procedure, based on LLE extraction with ethyl acetate followed by gas chromatography-electron-capture detection (GC-ECD) for quantification, and mass spectrometry (GC-MS) for confirmation, has been selected. Recoveries of spiked samples ranged from 68%, for beta-HCH, and 126% for p,p'-DDT, for fortification levels between 10 and 100 microg/kg, and 64%, for alpha-HCH, and 143% for gamma-HCH for fortification levels between 20 and 200 microg/kg. Limits of quantification, using GC-ECD, were from 0.01 and 0.10mg/kg, and limits of detection between 0.001 and 0.02 mg/kg. Fourteen Valencian samples were contaminated, containing residues of HCB or/and HCH isomers. The frequency of detection was 56% for Spanish samples. In Portugal, 23 samples were contaminated, what means 95.8%. In Spanish samples, concentrations range from nd to 0.03 mg/kg for HCB, and nd to 2.24 mg/kg for HCH-total. The mean concentration and standard deviation were 0.017+/-0.011 mg/kg for HCB, and 0.579+/-0.747 mg/kg for HCH-total, contributing the gamma isomer with the highest values. The samples from Portugal showed higher levels. Levels of HCB ranged from nd to 0.39 mg/kg. HCH-total ranged from nd to 4.86 mg/kg, and DDT-total from nd to 0.658 mg/kg. Mean concentration and standard deviation were 0.09+/-0.116 mg/kg for HCB, 1.357+/-1.30 mg/kg for HCH-total, and 0.143+/-0.193 mg/kg for DDT-total.

Chromatography, Gas↗
PubMed2004

Comparison of solid-phase microextraction and stir bar sorptive extraction for determining six organophosphorus insecticides in honey by liquid chromatography-mass spectrometry.

Two approaches based on sorptive extraction, solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE), in combination with liquid chromatography (LC)-atmospheric pressure chemical ionization mass spectrometry (MS) have been assayed for analyzing chlorpyriphos methyl, diazinon, fonofos, phenthoate, phosalone, and pirimiphos ethyl in honey. In both, SPME and SBSE, enrichment was performed using a poly(dimethylsiloxane) coating. Significant parameters affecting sorption process such as sample volume, sorption and desorption times, ionic strength, elution solvent, and dilution (water/honey) proportion were optimized and discussed. Performance of both methods has been compared through the determination of linearity, extraction efficiencies, and limits of quantification. Relative standard deviations for the studied compounds were from 3 to 10% by SPME and from 5 to 9% by SBSE. Both methods were linear in a range of at least two orders of magnitude, and the limits of quantification reached ranging from 0.04 to 0.4 mg kg(-1) by SBSE, and from 0.8 to 2 mg kg(-1) by SPME. The two procedures were applied for analyzing 15 commercial honeys of different botanical origin. SPME and SBSE in combination with LC-MS enabled a rapid and simple determination of organophosphorus pesticides in honey. SBSE showed higher concentration capability (large quantities of sample can be handled) and greater accuracy (between 5 and 20 times) and sensitivity (between 10 and 50 times) than SPME: thus, under equal conditions, SBSE is the recommended technique for pesticide analysis in honey.

Chromatography, Liquid↗
PubMed2004

Determination of dithiocarbamates and metabolites in plants by liquid chromatography-mass spectrometry.

A quantitative matrix solid-phase dispersion and liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) method is outlined for the simultaneous analysis of dithiocarbamates (DTCs) and their degradation products in plants. Compounds analyzed are dazomet, disulfiram, thiram and the metabolites ethylenthiourea and propylenthiourea. The performance of two different sample preparation protocols, the proposed one and other based on solid-phase extraction, as well as, of both atmospheric pressure ionization sources, APCI and electrospray, were compared. The effect of several parameters on the extraction, separation and detection was studied. Dithiocarbamates and metabolites were dispersed with carbograph, eluted with a mixture of dichloromethane-methanol, and then, identified by monitoring the base peak of the spectra corresponding to [M + H]+. The method was validated for avocados, cherries, lemons, nuts, oat, oranges, peaches, rice and tomatoes. Average recoveries varied from 33 to 109%, and relative standard deviation were between 4 and 21% with limits of quantification ranged from 0.25 to 2.5 mg kg(-1), except for thiram and disulfiram, which were not recovered from fruits with high acid content. The procedure was applied to the determination of DTCs and their metabolites in fruits, vegetables and cereals taken from different markets of Valencia, Spain.

Chromatography, Liquid↗
PubMed2002

Comparison of microextraction procedures to determine pesticides in oranges by liquid chromatography-mass spectrometry.

A liquid chromatographic-mass spectrometric method has been developed for the determination of bitertanol, carbendazim, fenthion, flusilazole, hexythiazox, imidacloprid, methidathion, methiocarb, pyriproxyfen and trichlorfon. Two procedures, based on stir bar sorptive extraction (SBSE) and matrix solid-phase dispersion (MSPD), have been evaluated for the extraction of these compounds in oranges. Their respective advantages and disadvantages are also discussed. The recoveries obtained by MSPD ranged from 47 to 96% and the relative standard deviations (RSDs) ranged from 1 to 15%, whereas with the SBSE method the recoveries were between 8 and 84% and the RSDs between 4 and 16%. Although, the limits of quantitation of most compounds are much better (0.001-0.05 mg kg(-1)) by SBSE, it is not suitable to determine some polar pesticides as carbendazim, imidacloprid and trichlorfon. Results obtained by both methods were compared, in terms of sensitivity and selectivity, with a classical ethyl acetate extraction method, and the three methods were applied to analyze real samples. As MSPD is easier to perform, faster than the organic solvent extraction, and shows equal accuracy and resolution, its application for analyzing pesticides in oranges is recommended.

Chromatography, Liquid↗
PubMed2002

Determination of fungicide residues in fruits and vegetables by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

A liquid chromatography (LC) method for the quantitative determination of five fungicide residues (dichloran, flutriafol, o-phenylphenol, prochloraz and tolclofos methyl) in oranges, lemons, bananas, peppers, chards and onions is described. The residues were extracted by matrix solid-phase dispersion (MSPD) using C8. Quantitative analysis was performed by isocratic LC coupled to quadrupole mass spectrometer using atmospheric pressure chemical ionization in the negative ionization mode. The limit of quantification was 0.01 mg kgmicro for flutriafol, o-phenylphenol and dichloran, and 0.1 mg kg(-1) for prochloraz and tolclofos methyl. The MSPD method is also suitable for LC-UV analysis but higher limits of quantification (between 1 and 5 mg kg(-1)) were obtained. Validation of the method was performed between 0.01 and 25 mg kg(-1). Recoveries for fungicides ranged from 52.5 to 91.1% with relative standard deviations between 6.1 and 11.9%. The method was applied to the determination of residues in samples taken from agricultural cooperatives. The fungicides most often detected were o-phenylphenol and prochloraz.

Atmospheric Pressure↗
PubMed2001

[Effects of levofolinic acid on plasma homocysteine concentrations in healthy and young women in preconceptional care].

BACKGROUND: Increases in total plasmatic homocysteine (tHcy) represents a risk factor for neural tube defects. We studied the effects of levofolinic acid (l,5-formyl-tetrahydrofolic) on the plasmatic tHcylevels in women of child-bearing age. MATERIALS AND METHOD: Healthy women aged 18-35 years (n = 30) received levofolinic acid, 5 mg/day,orally for 30 days. Both tHcy and intraerythrocytic folate levels were measured before treatment (day 0), on days 2, 5, 10 and 30 within the treatment period and on days 30 (day 60) and 60 (day 90) after the treatment was finished. Plasmatic tHcy was measured by fluorescence polarisation immunoassay and intraerythrocyticfolates by chemiluminescent immunoassay. RESULTS: Plasmatic tHcy decreased from the second day of treatment onwards (day 0 vs. 2: mean of difference: -1.24 micromol/l; CI 95% = -0.84 to -1.63; p < 0.001). The maximum decline (32.3%) was observed after 30 days (mean of difference = -2.72 micromol/l; CI 95% = -2.20 to -3.24; p < 0.001).After finishing the treatment, the hypohomocysteinic effect persisted up to days 60 (mean of difference = -2.67 micromol/l; CI 95% = -2.07 to -3.26; p < 0.001)and 90 (mean of difference = -1.49 micromol/l; CI 95% = -0.94 to -2.03; p < 0.001). The response was greater when the plasmatic tHcy concentration was >= 9 micromol/l. CONCLUSIONS: Levofolinic acid leads to a earlier, intense and persistent drop of the plasmatictHcy levels.

Adult↗
PubMed1999

Differential role of ethanol and acetaldehyde in the induction of oxidative stress in HEP G2 cells: effect on transcription factors AP-1 and NF-kappaB.

The oxidative metabolism of ethanol by the cytochrome P450 2E1 (CYP2E1) has been recognized to contribute to the ethanol-induced deleterious effects through the induction of oxidative stress. This study compared the effect of ethanol and acetaldehyde in the induction of oxidative stress and activation of transcription factors nuclear factor-kappaB (NF-kappaB) and activating protein 1 (AP-1) in HepG2 cells, which do not express CYP2E1, and HepG2 cells transfected with CYP2E1 (E47 cells). Neither ethanol (80 mmol/L) nor acetaldehyde (25-200 micromol/L) caused oxidative stress in HepG2 cells, an effect that was independent of blocking reduced glutathione (GSH) synthesis with buthionine-L-sulfoximine (BSO). However, BSO preincubation caused an overproduction of peroxides and activation of NF-kappaB and AP-1 in E47 cells even in the absence of ethanol. Furthermore, the incubation of E47 cells with ethanol (80 mmol/L for up to 5 days) depleted cellular GSH stores in both cytosol and mitochondria, reflecting the induction of oxidative stress. Ethanol activated NF-kappaB and AP-1 in E47 cells, an effect that was prevented by 4-methylpyrazole, potentiated by cyanamide, and attenuated by trolox C. Interestingly, however, despite the inability of acetaldehyde to induce oxidative stress in HepG2, acetaldehyde activated NF-kappaB and AP-1; in contrast, ethanol failed to activate these transcription factors in HepG2. Thus, our findings indicate that activation of NF-kappaB and AP-1 by ethanol and acetaldehyde occurs through distinct mechanisms. CYP2E1 is indispensable in the induction of oxidative stress from ethanol, whereas the activation of NF-kappaB and AP-1 by acetaldehyde is independent of oxidative stress.

Acetaldehyde↗
PubMed1996

[Value of the emergency therapeutic endoscopy in gastrointestinal hemorrhage].

The experience in therapeutic digestive endoscopy is presented using injection technique with adrenalin-polidocanol of gastrointestinal hemorrhage lesions. One hundred and twenty nine patients were treated endoscopically; the medium age was 60 years; in almost 80% of the cases, peptic ulcer disease were found. The effectiveness was 91.4% when one session procedure was used and in some cases two sessions were applied, giving a final total arrest of hemorrhage of 95.3%. The total mortality still remain high (16.3%) even without bleeding, due to coexisting poor general conditions of the patients. The technique of endoscopic injection is reviewed and the final results of our work are presented.

Adult↗
PubMed1987

Thyroxine in unextracted urine.

The aim of this work was to estimate the daily urinary excretion of free and conjugated thyroxine using a direct radioimmunoassay and enzyme hydrolysis. The renal clearance of free T4 was also determined. The mean urinary values of free and total T4 (mean +/- 1 SD) in 112 euthyroid controls were 1353 +/- 496 and 1855 +/- 651 pmol/24 h, respectively. Urinary excretion of free hormone in 13 hyperthyroid patients was 5552 +/- 4320 pmol/24 h and total T4 was 8122 +/- 7219 pmol/24 h. Urinary free T4 excretion was 223 +/- 223 pmol/24 h in hypothyroid patients and total T4 was 542 +/- 490 pmol/24 h. These results indicate that daily urinary T4 excretion is a good indicator of thyroid function. The mean renal clearance of free T4 was 52 +/- 19 ml/min (mean +/- 1 SD) in euthyroid patients, 53.7 +/- 12.3 ml/min in hyperthyroid patients, and 67.6 +/- 13.1 ml/min in hypothyroid patients. We estimated the endogenous creatinine renal clearance as a control of the renal filtration rate. The data suggest that there is T4 filtration of unbound T4 and partial tubular reabsorption. Further experimental studies will be necessary to clarify the renal handling of thyroxine as well as the fate of reabsorbed T4.

Adult↗
PubMedDate not supplied

Nursing protocol for manipulation of haemodialysis catheters.

This study looked at the incidence of infection complications, in relation to central vein catheterisation as a provisional HD access, by means of the establishment of a nursing protocol for the handling of these catheters. Central vein catheterisation is a classical technique in Nephrology.

Adult↗
PubMedDate not supplied

[Factors affecting the qualitative and quantitative composition of the acari fauna of house dust. III. Seasons].

The seasonal variations in the number of mites present in the house dust of six homes in Barcelona were studied. The samples were taken at monthly intervals between September 1972 and January 1974. Tables I and II show the total number of mites and the number of Pyroglyphidae present in each of the samples. Table III shows the monthly average of the atmospheric temperature and relative humidity (R.H.). Graphing the average of mites present in the monthly samples and comparing them to the graph of the atmospheric R.H. an almost perfect correlation of the atmospheric R.H. with the number of mites was observed (Graph 1). The statistical analysis of the results shows the existence of a highly significant correlation (alpha less than 0.001) between the average of the atmospheric R.H. of a given month and the decimal logarithm of the number of mites present in the house dust the following month (Tables IV and V; Graphs 4 and 5). The following results can be pointed out: a) The quality of mites in the house dust of Barcelona changes considerably during the year. b) The quantity is greatest during spring and autumn. c) The annual variation differs from year to year. In conclusion, it is shown that the seasonal variations in the quantity of mites present in the house dust of Barcelona are proportional to the variations in atmospheric R.H.

Acari↗
PubMedDate not supplied

[Endoscopic cholangiography in the postcholecystectomy syndrome].

The purpose of this study was to evaluate the usefulness of endoscopic pancreatocholangiography in a group of patients having undergone surgical operations on bile ducts. This is a retrospective study including 64 patients in whom cholocystectomy was performed both with or without previous exploration of bile ducts. Forty five of these patients were jaundiced and 20 had abdominal pain as main symptoms. Forty nine were females and 15 males, their ages ranging between 18 and 80 years. The canulation of Vate's ampulla and the adequate darkening of the bile ducts was achieved in every case and the cholangiography showed recidual or recurring lithiasis in 75 per cent of the cases; in 67 per cent there was postsurgical stenosis of bile ducts; remnant cystic duct in 74.8 per cent; stenosis of Oddi's sphincter in 50.9 per cent, and in 13.3 a diagnosis of cholestasis was established. This procedure was quite useful in order to establish the correct diagnosis in this group of patients having a postcholecystectomy syndrome.

Abdomen↗
PubMedDate not supplied

[Pancreatic changes in patients with liver cirrhosis caused by alcoholism].

Alcoholism in frequently associated to inflammatory lesions of the pancreas. The changes involved have been duly depicted in necropsis studies. In this paper we have evaluated the association of pancreatic changes in patients undergoing hepatic cirrhosis due to alcoholism by means of endoscopic pancreatography. Forty four patients were studied by endoscopic pancreatography, 25 males and 19 females. Their ages varied between 22 and 81 year old. Three groups were formed; the first one by 19 patients with hepatic cirrhosis due alcoholism; the second group by 7 patients with hepatic cirrhosis in whom no alcoholic antecedents could be ascertained; the third group was formed by 18 non alcoholic, non cirrhotic individuals. Pancreatography was performed by means of a JF-B3 duodenoscope. In 12 out of 19 patients with alcoholic hepatic cirrhosis, the pancreatography showed changes such as irregularities in the ducts, sacular formations, retarded emptying with partial filling, shortening and stenosis of the ducts, changes usually present in patients with chronic pancreatitis. Both in groups II and III no pathologic changes were found in pancreatography. From the radiologic standpoint alone one cannot eestablish the diagnosis of chronic pancreatitis, although we consider that the usefulness of the pancreatography is that of making quite apparent the above said alterations in the alcoholic cirrhotics patients and stablish the adequate therapeutic conduct.

Adult↗