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1.
Energy Policy ; 148: 111964, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33071429

ABSTRACT

Electricity demand and its typical load pattern are usually affected by many endogenous and exogenous factors to which the generation system must accordingly respond through utility operators. Lockdown measures to prevent the spread of COVID-19 imposed by many countries have led to sudden changes in socioeconomic habits which have had direct effects on the electricity systems. Therefore, a detailed analysis of how confinement measures have modified the electricity consumption in Spain, one of the countries most affected by this pandemic, has been performed in this work. Its electricity consumption has decreased by 13.49% from March 14 to April 30, compared to the average value of five previous years. Daily power demand profiles, especially morning and evening peaks, have been modified at homes, hospitals, and in the total power demand. These changes generate a greater uncertainty for the System Operator when making demand forecasts, but production deviations have increased by only 0.1%, thanks to the presence of a diversified generation mix, which has been modified during this period, increasing the proportion of renewable sources and decreasing CO2 emissions.

2.
Diabet Med ; 34(2): 286-290, 2017 02.
Article in English | MEDLINE | ID: mdl-27027642

ABSTRACT

AIMS: To test the hypothesis that non-obese individuals with childhood-onset Type 1 diabetes and the rs7903146 TT genotype would be less likely to have high-risk human leukocyte antigen (HLA) genotypes and alleles. METHODS: We studied a cohort of 105 non-obese participants in the T1D Exchange Biobank Residual Insulin Study who had childhood-onset Type 1 diabetes [mean (sd) age at onset and recruitment, respectively, 9.9 (4.15) and 14.4 (4.13) years; 84.8% non-Hispanic white]. We analysed islet autoantibodies (glutamic acid decarboxylase 65, islet cell autoantigen 512/islet antigen-2 and zinc transporter 8), non-fasting random C-peptide levels, HLA type and TCF7L2 single nucleotide polymorphism rs7903146 in this cohort. RESULTS: None of the 13 individuals with the rs7903146 TT genotype carried the highest Type 1 diabetes risk HLA genotype, i.e. DRB1*03:01/DR4 (DRB1*0401, *04:05 or *04:02), compared with 29.4% (27/92) of those without it (P=0.023). The DRB1*03:01 allele was present in 15.4% (2/13) of individuals with the single nucleotide polymorphism, compared with 59.8% (55/92) of those without it (P=0.003). Analyses restricted to autoantibody-positive individuals (n=80) yielded similar results. The HLA DRB1*15:01 allele, which affords dominant protection against Type 1 diabetes, was found in one participant, who had multiple islet autoantibodies and carried the rs7903146 TT genotype. CONCLUSIONS: These findings further support the hypothesis that TCF7L2 gene variation contributes to diabetogenesis in a subset of young people with Type 1 diabetes, opening possible new pathways for therapy and prevention.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Adolescent , Autoantibodies/immunology , C-Peptide/metabolism , Child , Child, Preschool , Cohort Studies , Diabetes Mellitus, Type 1/immunology , Female , Genetic Predisposition to Disease , Glutamate Decarboxylase/immunology , HLA-DRB1 Chains/genetics , Humans , Male , Polymorphism, Single Nucleotide , Transcription Factor 7-Like 2 Protein/genetics , Zinc Transporter 8/immunology
3.
Diabet Med ; 34(10): 1435-1439, 2017 10.
Article in English | MEDLINE | ID: mdl-28626948

ABSTRACT

AIM: To compare demographic and clinical characteristics among children from ethnic minorities and non-Hispanic white children with new-onset autoimmune Type 1 diabetes. METHODS: We analysed a single-centre series of 712 children with new-onset autoimmune Type 1 diabetes between January 2008 and March 2011. The median (range) age was 9.7 (0.3-18.1) years, the mean (sd) BMI percentile was 69.7 (25.4) and 48.3% of the cohort were girls. The cohort comprised 57.3% non-Hispanic white, 20.5% Hispanic and 14.8% African-American children, and 7.4% were of other, mixed or unknown race. RESULTS: The Hispanic subgroup, compared with non-Hispanic white subgroup, had a higher mean (sd) C-peptide level [0.82 (1.62) vs 0.55 (0.47) ng/ml; P=0.004), and a greater proportion of children with elevated BMI (overweight or obesity; 49.6% vs 32.5%; P<0.001) and diabetic ketoacidosis (51.8% vs 38.2%; P=0.006). The African-American group had a higher mean (sd) glucose level [24.4 (12.8) vs 21.4 (10.7) mmol/l; P=0.017], a greater proportion of children with ketoacidosis (56.7% vs 38.2%; P=0.001), a greater proportion with elevated BMI (52.9% vs 32.5%; P<0.001), and a lower proportion of children at pre-pubertal stage (49.0% vs 61.6%; P=0.01), and tended to have higher C-peptide levels [0.65 (0.59) vs 0.55 [0.47] ng/ml; P=0.079) compared with the non-Hispanic white children. The differences in C-peptide levels compared with non-Hispanic white children persisted for Hispanic (P=0.01) but not African-American children (P=0.29) after adjustment for age, sex, BMI, ketoacidosis, glucose, Tanner stage and autoantibody number. CONCLUSION: At the onset of paediatric autoimmune Type 1 diabetes, Hispanic, but not African-American children had higher C-peptide levels, after adjustment for potential confounders, compared with non-Hispanic white children. These findings suggest that ethnicity may contribute to the heterogeneity of Type 1 diabetes pathogenesis, with possible implications for intervention.


Subject(s)
Diabetes Mellitus, Type 1/ethnology , Ethnicity/statistics & numerical data , Racial Groups/statistics & numerical data , Adolescent , Child , Child, Preschool , Cohort Studies , Cross-Sectional Studies , Female , Humans , Infant , Male , Overweight/complications , Overweight/ethnology , Pediatric Obesity/complications , Pediatric Obesity/ethnology
4.
Diabet Med ; 34(5): 641-646, 2017 05.
Article in English | MEDLINE | ID: mdl-26802570

ABSTRACT

AIM: To study whether DPD epitope-specific glutamate decarboxylase autoantibodies are found more frequently in children with milder forms of Type 1 diabetes. METHODS: We prospectively evaluated 75 children with new-onset autoimmune Type 1 diabetes, in whom we collected demographic, anthropometric and clinical data and measured islet autoantibodies. Glutamate decarboxylase 65 autoantibody-positive samples were analysed for epitope specificities using recombinant Fab against the DPD-defined epitope of glutamate decarboxylase 65. RESULTS: After adjustment for age, positive DPD epitope recognition was significantly associated with higher C-peptide levels at onset (P = 0.02, r2 =0.21, n = 35), and high DPD recognition in the highest quartile tended to be associated with HbA1c ≤ 53 mmol/mol (7%) at the last follow-up [mean (sd) follow-up 1.3 (0.4) years; P = 0.07; for the model, P = 0.044, n = 30)]. Age- and sex-adjusted BMI percentile was significantly correlated with recognition of the DPD-defined epitope (P < 0.03, r2 =0.14, n = 34), but this correlation was driven by the older age group (age ≥ 10 years; P = 0.016, r2 =0.27, n = 21) and was not significant in younger children (P = 0.93, n = 13). There were no independent associations with sex, race/ethnicity, diabetic ketoacidosis, HbA1c , HLA DR3-DQ2/DR4-DQ8 or autoantibody number. CONCLUSIONS: Our findings suggest that recognition of the DPD-defined glutamate decarboxylase 65 autoantibody epitope at Type 1 diabetes onset is directly associated with ß-cell function, BMI and age, which supports the hypothesis that immunological factors contribute to the clinical heterogeneity of Type 1 diabetes. Larger studies relating epitope-specific glutamate decarboxylase 65 autoantibody to clinical phenotype in children with Type 1 diabetes are warranted.


Subject(s)
Autoantibodies/blood , Diabetes Mellitus, Type 1/blood , Glutamate Decarboxylase/immunology , Adolescent , Antibody Specificity , Autoantibodies/chemistry , C-Peptide/blood , Cation Transport Proteins/immunology , Child , Child, Preschool , Diabetes Mellitus, Type 1/immunology , Epitopes/immunology , Female , Glutamate Decarboxylase/chemistry , Humans , Infant , Male , Receptor-Like Protein Tyrosine Phosphatases, Class 8/immunology , Zinc Transporter 8
5.
Pediatr Diabetes ; 15(8): 543-9, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24978596

ABSTRACT

BACKGROUND/OBJECTIVE: Obesity increases the risk of cardiovascular disease and diabetic complications in type 1 diabetes. Adipokines, which regulate obesity-induced inflammation, may contribute to this association. We compared serum adipokines and inflammatory cytokines in obese and lean children with new-onset autoimmune type 1 diabetes. SUBJECTS AND METHODS: We prospectively studied 32 lean and 18 obese children (age range: 2-18 yr) with new-onset autoimmune type 1 diabetes and followed them for up to 2 yr. Serum adipokines [leptin, total and high molecular weight (HMW) adiponectin, omentin, resistin, chemerin, visfatin], cytokines [interferon (IFN)-gamma, interleukin (IL)-10, IL-12, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha] and C-reactive protein (CRP) were measured at a median of 7 wk after diagnosis (range: 3-16 wk). RESULTS: Lean children were 71.9% non-Hispanic White, 21.9% Hispanic, and 6.3% African-American, compared with 27.8, 55.6, and 16.7%, respectively, for obese children (p = 0.01). Compared with lean children, obese children had significantly higher serum leptin, visfatin, chemerin, TNF-alpha and CRP, and lower total adiponectin and omentin after adjustment for race/ethnicity and Tanner stage. African-American race was independently associated with higher leptin among youth ≥10 yr (p = 0.007). Leptin levels at onset positively correlated with hemoglobin A1c after 1-2 yr (p = 0.0001) independently of body mass index, race/ethnicity, and diabetes duration. Higher TNF-alpha was associated with obesity and female gender, after adjustment for race/ethnicity (p = 0.0003). CONCLUSION: Obese children with new-onset autoimmune type 1 diabetes have a proinflammatory profile of circulating adipokines and cytokines that may contribute to the development of cardiovascular disease and diabetic complications.


Subject(s)
Adiposity , Biomarkers/blood , Diabetes Mellitus, Type 1/blood , Pediatric Obesity/blood , Thinness/blood , Adipokines/blood , Adolescent , Age of Onset , Child , Child, Preschool , Cytokines/blood , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/epidemiology , Female , Follow-Up Studies , Humans , Male , Pediatric Obesity/complications , Thinness/complications
6.
J Fish Dis ; 37(9): 785-96, 2014 Sep.
Article in English | MEDLINE | ID: mdl-23957839

ABSTRACT

The enteric myxozoan parasites Enteromyxum leei (Diamant, Lom et Dyková) and Enteromyxum scophthalmi Palenzuela, Redondo et Álvarez-Pellitero are responsible for high weight loss in infected fish, which leads to subchronic disease and low mortality rates in gilthead sea bream (GSB), Sparus aurata L., and to high mortality rates in turbot, Psetta maxima (L.). The detection of initial parasite stages in histological sections is particularly difficult, but can be simplified by means of specific antibodies. Rabbit polyclonal antibodies (pAbs) were raised against E. scophthalmi and E. leei, and direct enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were used to characterize their sensitivity and specificity. Both pAbs were adsorbed (apAb) with non-infected intestines to avoid non-specific labelling of fish tissues and to improve their specificity. The highest titre obtained in ELISA was 1: 32 000 for apAb-Eleei and 1:16 000 for apAb-Escoph. Working dilutions in immunohistochemistry were 1:1000 for apAb-Eleei and 1:8000 for apAb-Escoph. Both apAbs labelled proliferative and sporogonic stages with high specificity. apAb-Escoph was very specific, whereas apAb-Eleei cross-reacted with Sphaerospora dicentrarchi Sitjà-Bobadilla et Álvarez-Pellitero and Sphaerospora testicularis Sitjà-Bobadilla et Álvarez-Pellitero, suggesting the presence of shared antigens. These pAbs stand as new tools for antigenic characterization and the diagnosis of both Enteromyxum species.


Subject(s)
Antibodies/immunology , Antigens/immunology , Fish Diseases/immunology , Flatfishes , Myxozoa/physiology , Parasitic Diseases, Animal/immunology , Animals , Cross Reactions , Enzyme-Linked Immunosorbent Assay/veterinary , Fish Diseases/parasitology , Immunohistochemistry/veterinary , Parasitic Diseases, Animal/parasitology , Species Specificity
7.
Dis Aquat Organ ; 89(3): 209-21, 2010 Apr 09.
Article in English | MEDLINE | ID: mdl-20481088

ABSTRACT

In the last decade, a new parasite that causes severe losses has been detected in farmed turbot Psetta maxima (L.), in north-western Spain. The parasite was classified as a myxosporean and named Enteromyxum scophthalmi. The aim of this study was to characterize the main histological changes that occur in E. scophthalmi-infected turbot. The parasite provoked catarrhal enteritis, and the intensity of the lesions was correlated with the progression of the infection and with the development of the parasite. Infected fish were classified into 3 groups, according to the lesional degree they showed (slight, moderate and severe infections). In fish with slight infections, early parasitic stages were observed populating the epithelial lining of the digestive tract, without eliciting an evident host response. As the disease progressed, catarrhal enteritis was observed, the digestive epithelium showed a typical scalloped shape and the number of both goblet and rodlet cells was increased. Fish with severe infections suffered desquamation of the epithelium, with the subsequent release of parasitic forms to the lumen. The dislodged enterocytes underwent anoikis, a mode of apoptosis triggered by the loss of anchorage, which might facilitate spreading of the parasite. Lymphohaematopoietic depletion was also observed, mainly in head kidney and spleen, which could contribute to the high virulence of this parasite.


Subject(s)
Enteritis/veterinary , Fish Diseases/parasitology , Flatfishes , Myxozoa/isolation & purification , Parasitic Diseases, Animal/parasitology , Animals , Enteritis/parasitology , Enteritis/pathology , Fish Diseases/pathology , Microscopy, Electron , Myxozoa/ultrastructure
9.
J Clin Invest ; 107(5): 555-64, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11238556

ABSTRACT

Recent reports indicate that genes with tissue-restricted expression, including those encoding the type 1 diabetes autoantigens insulin, glutamic acid decarboxylase (GAD), and the tyrosine-phosphatase-like protein IA-2 (or ICA512), are transcribed in the thymus. The reported modulation of diabetes susceptibility by genetically determined differences in thymic insulin levels and studies in transgenic mice provide correlative and functional evidence that thymic expression of peripheral proteins is crucial for immunological self-tolerance. However, there are no specific data about the existence, tissue distribution, phenotype, and function of those cells that express insulin and other self-antigens in the human thymus. We find that the human thymus harbors specialized cells synthesizing (pro)insulin, GAD, and IA-2, mainly localized in the medulla, and we demonstrate such cells also in peripheral lymphoid organs (spleen and lymph nodes). Phenotypic analysis qualifies these cells as antigen-presenting cells (APCs), including both dendritic cells and macrophages. These cells often appear surrounded by apoptotic lymphocytes, both in thymus and spleen, and may therefore be involved in the deletion of autoreactive lymphocytes. Our findings demonstrate the existence of, and define the tissue distribution and phenotype of, a novel subset of APCs expressing self-antigens in human lymphoid organs that appear to be involved in the regulation of self-tolerance throughout life.


Subject(s)
Antigen-Presenting Cells/immunology , Autoantigens/immunology , Diabetes Mellitus, Type 1/immunology , Self Tolerance , Thymus Gland/immunology , Adolescent , Adult , Aged , Apoptosis , Autoantigens/biosynthesis , Clonal Deletion , Female , Gene Expression , Glutamate Decarboxylase/biosynthesis , Glutamate Decarboxylase/immunology , Humans , Infant , Infant, Newborn , Lymph Nodes/immunology , Lymphocytes/immunology , Male , Membrane Proteins/biosynthesis , Membrane Proteins/immunology , Middle Aged , Phenotype , Proinsulin/biosynthesis , Proinsulin/immunology , Protein Tyrosine Phosphatase, Non-Receptor Type 1 , Protein Tyrosine Phosphatases/biosynthesis , Protein Tyrosine Phosphatases/immunology , Receptor-Like Protein Tyrosine Phosphatases, Class 8 , Spleen/immunology
10.
Diabetes ; 48(11): 2166-70, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10535450

ABSTRACT

Wilson and coworkers (Wilson SB, Kent SC, Patton KT, Orban T, Jackson RA, Exley M, Porcelli S, Schatz DA, Atkinson MA, Balk SP, Strominger JL, Hafler DA: Extreme Th1 bias of invariant V alpha24J alpha Q T-cells in type 1 diabetes. Nature 391:177-181, 1998) have recently reported raised serum levels of interleukin-4 (IL-4) in anti-islet autoantibody-positive first-degree relatives of patients with type 1A diabetes who did not progress to diabetes. Protection from diabetes has been noted for several human lymphocyte antigen (HLA) alleles, such as HLA DR2-DQA1*0102-DQB1*0602. We, therefore, wanted to determine whether this cytokine phenotype was associated with HLA genes protective for type 1A diabetes. We used a two-site fluoroimmunoassay with the same monoclonal antibodies as those reported by Wilson et al. Using this assay, we have found evidence for human heterophile antibodies mimicking serum IL-4: all serum IL-4 reactivity was lost if mouse serum or mouse immunoglobulin were added to the assay; serum IL-4 activity was bound and then eluted by protein A/G chromatography; and levels of anti-mouse antibodies correlated with apparent serum IL-4. This pseudo-IL-4 activity was found in a subset of control subjects, patients with type 1A diabetes, and their relatives and was primarily associated with specific HLA alleles protective for type 1A diabetes (e.g., DQB1*0602). After adjustment for HLA, positive levels of heterophile antibodies were not associated with protection from diabetes. The confounding effect of protective HLA alleles associated with heterophile antibodies could explain the previously reported association between raised serum IL-4 and protection from type 1A diabetes. The mechanism by which specific DQ alleles protect from diabetes and are associated with increased heterophile antibodies is currently unknown.


Subject(s)
Antibodies, Heterophile/immunology , Cytokines/blood , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Genes, MHC Class II , HLA-DQ Antigens/genetics , HLA-DR2 Antigen/genetics , Interleukin-4/blood , Alleles , Animals , Child, Preschool , Cohort Studies , Diabetes Mellitus, Type 1/mortality , Disease Progression , Family , HLA-DQ alpha-Chains , Humans , Immunoglobulin G/blood , Mice , Survival Rate
11.
J Clin Endocrinol Metab ; 85(10): 3793-7, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11061540

ABSTRACT

The transmission disequilibrium test was used to analyze haplotypes for association and linkage to diabetes within families from the Human Biological Data Interchange type 1 diabetes repository (n = 1371 subjects) and from the Norwegian Type 1 Diabetes Simplex Families study (n = 2441 subjects). DQA1*0102-DQB1*0602 was transmitted to 2 of 313 (0.6%) affected offspring (P < 0.001, vs. the expected 50% transmission). Protection was associated with the DQ alleles rather than DRB1*1501 in linkage disequilibrium with DQA1*0102-DQB1*0602: rare DRB1*1501 haplotypes without DQA1*0102-DQB1*0602 were transmitted to 5 of 11 affected offspring, whereas DQA1*0102-DQB1*0602 was transmitted to 2 of 313 affected offspring (P < 0.0001). Rare DQA1*0102-DQB1*0602 haplotypes without DRB1*1501 were never transmitted to affected offspring (n = 6). The DQA1*0101-DQB1*0503 haplotype was transmitted to 2 of 42 (4.8%) affected offspring (P < 0.001, vs. 50% expected transmission). Although DRB1*1401 is in linkage disequilibrium with DQB1*0503, neither of the two affected children who carried DQA1*0101-DQB1*0503 had DRB1*1401. However, all 13 nonaffected children who inherited DQA1*0101-DQB1*0503 had DRB1*1401. In a case-control comparison of patients from the Barbara Davis Center, DQA1*0101-DQB1*0503 was found in 5 of 110 (4.5%) controls compared with 3 of 728 (0.4%) patients (P < 0.005). Of the three patients with DQB1*0503, only one had DRB1*1401. Our data suggest that both DR and DQ molecules (the DRB1*1401 and DQA1*0102-DQB1*0602 alleles) can provide protection from type 1A diabetes.


Subject(s)
Diabetes Mellitus, Type 1/genetics , HLA-DQ Antigens/genetics , HLA-DR Antigens/genetics , Cell Line , DNA/genetics , Genetic Linkage/genetics , HLA-DQ alpha-Chains , HLA-DRB1 Chains , Histocompatibility Testing , Humans
12.
Diabetes Metab ; 23(6): 519-23, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9496558

ABSTRACT

The purpose of this study was to determine the incidence of non-traumatic lower extremity amputations (LEAs) in diabetic and non-diabetic subjects in Madrid, Spain, and their direct cost. All patients who underwent LEAs between the 1st of January 1994 and the 31st of December 1996, and who had lived in area 7 of the city (569,307 inhabitants) for at least the last 6 months, were identified through operating theatre records cross-checked with Vascular Surgery Department discharge records. In addition, the direct cost of LEAs per year was estimated, taking into account the length of the hospital stay, the period of rehabilitation in the outpatient clinic after discharge, and the use of artificial limbs and their maintenance. The incidence of LEAs was 1.6 (95% CI: 1.1-2.2) per 10(5) non-diabetic subjects and 46.1 (95% CI: 34.5-57.6) per 10(5) diabetic patients. Relative risk was 28. Total direct costs associated with LEAs per year were US$ 56,131 in the diabetic population and US$ 30,765 in the non-diabetic population. Thus, potential cost savings associated with excess amputations in the diabetic population was estimated at US$ 541,353 per year of US$ 94,736 per 10(5) inhabitants. It is concluded that the incidence of LEAs in both diabetic and non-diabetic populations in area 7 is the lowest reported in European countries. The potential cost savings per 10(5) inhabitants and per year is estimated at US$ 94,736.


Subject(s)
Amputation, Surgical/statistics & numerical data , Diabetic Foot/surgery , Leg , Adult , Aged , Amputation, Surgical/economics , Amputation, Surgical/rehabilitation , Artificial Limbs , Costs and Cost Analysis , Diabetic Foot/economics , Female , Humans , Length of Stay , Male , Medical Records , Middle Aged , Spain
13.
J Chromatogr A ; 693(2): 339-46, 1995 Feb 24.
Article in English | MEDLINE | ID: mdl-7704189

ABSTRACT

The utility of solid-phase extraction with octadecylsilica for determining fifteen polychlorinated biphenyl (PCB) congeners from milk samples was examined. Recoveries higher than 80% and relative standard deviations better than 10% were obtained for PCBs from different kinds of milk (whole, skimmed, 2%, powdered, breast and evaporated). A comparison with other procedures was made. The described method provides better detection limits than those attainable with the liquid-liquid extractions currently used as standard methods, when capillary gas-liquid chromatography is used for the final determination. A study of the separation was also performed using six different fused-silica capillary columns and an electron-capture detector.


Subject(s)
Chromatography, Gas/methods , Milk, Human/chemistry , Milk/chemistry , Polychlorinated Biphenyls/analysis , Animals
14.
J Chromatogr A ; 822(1): 67-73, 1998 Sep 25.
Article in English | MEDLINE | ID: mdl-9810712

ABSTRACT

LiChrolut EN [poly(styrene-divinylbenzene), PSDVB], Carbograph (graphitized carbon black, GCB), Isolute CN (cyanopropylsilica), Isolute C2 (ethylsilica), and LiChrospher RP18 (octadecylsilica) were studied for on-line solid-phase extraction of twelve nitrogen containing pesticides from water. Determination (UV 210 nm) was performed with a Spherisorb C8 analytical column and an acetonitrile-water gradient. The mean recoveries from 50 ml ranged from 83% for RP18 to 44% for GCB, and decreased in the following order: RP18, CN, LiChrolut EN, C2, and GCB. GCB showed poor recoveries due to incomplete desorption with the acetonitrile-water gradient used, and memory effects were detected. Backflush was needed to elute selected pesticides from GCB and from LiChrolut EN. Breakthrough volumes were 50-100 ml for most selected pesticides with silica-based phases, whereas LiChrolut EN allowed larger sample volumes without observable losses.


Subject(s)
Nitrogen/chemistry , Pesticides/analysis , Carbon , Chromatography, High Pressure Liquid , Indicators and Reagents , Pesticides/chemistry , Polystyrenes , Silicon Dioxide , Spectrophotometry, Ultraviolet , Vinyl Compounds
15.
J Chromatogr A ; 839(1-2): 101-7, 1999 Apr 16.
Article in English | MEDLINE | ID: mdl-10327624

ABSTRACT

A multiresidue method based on matrix solid-phase dispersion (MSPD) microextraction was studied to determine the carbamate, benfuracarb, and urea insecticides, diflubenzuron, flufenoxuron hexaflumuron and hexythiazox, used in control of citrus pests. Optimisation of different parameters, such as the type of solid support for matrix dispersion, elution solvents and the clean-up step were carried out. The method used 0.5 g of orange sample, C8 bonded silica as MSPD sorbent and dichloromethane as eluting solvent. Recoveries, at spiked concentrations below the maximum residue levels established by Spanish Government, were between 74 and 84% with relative standard deviations ranging from 2 to 4%. The limits of quantification were from 0.15 to 0.25 microgram/g using high-performance liquid chromatography with UV detection at 200 nm. The method may be useful as a screening protocol for the determination of these newly developed pesticides in citrus samples.


Subject(s)
Chromatography, High Pressure Liquid/methods , Fruit/chemistry , Pesticide Residues/analysis , Benzamides/analysis , Benzofurans/analysis , Diflubenzuron/analysis , Indicators and Reagents , Insecticides/analysis , Phenylurea Compounds/analysis , Quality Control , Sensitivity and Specificity , beta-Alanine/analogs & derivatives , beta-Alanine/analysis
16.
J Chromatogr A ; 918(1): 59-65, 2001 May 18.
Article in English | MEDLINE | ID: mdl-11403456

ABSTRACT

Various liquid chromatographic (LC) techniques for analyzing avermectin (Abamectin) were compared after extraction of residues from citrus fruit samples by matrix solid-phase dispersion (MSPD). LC with UV and fluorescence detection were used as also was LC coupled to the mass spectrometer by an electrospray interface. The results obtained by the three methods were compared in terms of sensitivity and selectivity. The combination of MSPD extraction and LC with fluorescence detection have made it possible to quantify 0.5 microg kg(-1) of Abamectin in 0.5 g of orange sample, with an overall average recovery of 94%. The procedure provides a simple and sensitive method for monitoring Abamectin residues in citrus fruit at the levels required by legislation.


Subject(s)
Chromatography, Liquid/methods , Citrus/chemistry , Drug Residues/analysis , Ivermectin/analysis , Ivermectin/analogs & derivatives , Sensitivity and Specificity , Spectrometry, Fluorescence , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Ultraviolet
17.
J Chromatogr A ; 719(1): 95-103, 1996 Jan 05.
Article in English | MEDLINE | ID: mdl-8589838

ABSTRACT

A multiresidue extraction method based on matrix solid-phase dispersion (MSPD) is optimized for the extraction and gas chromatographic screening of eighteen insecticides (aldrin, carbophenothion, captafol, chlorpyriphos, chlorfenvinphos, diazinon, dicofol, alpha-endosulfan, beta-endosulfan, ethion, fenitrothion, folpet, methidathion, malathion, methyl-azinphos, methyl-parathion, phosmet, and tetradifon) from oranges. After optimization of different parameters, such as type of solid phase used and the amount of solid phase or eluent, recoveries ranged from 67 to 102% with relative standard deviations ranging from 2 to 10%. The limits of detection, calculated as 3 times the baseline noise ranged from 2 to 171 micrograms/kg. These limits of detection were about 10 times lower than the maximum residue levels established by the European Community. Compared with classical methods, the described procedure is simple, less labour intensive and does not require preparation and maintenance of equipment. Troublesome emulsions, such as those frequently observed in liquid-liquid partitioning did not occur.


Subject(s)
Chromatography, Gas/methods , Citrus/chemistry , Pesticide Residues/analysis , Acetates , Chromatography, Gas/statistics & numerical data , Microchemistry , Sensitivity and Specificity , Solvents
18.
J Chromatogr A ; 871(1-2): 57-65, 2000 Feb 25.
Article in English | MEDLINE | ID: mdl-10735286

ABSTRACT

Liquid chromatography coupled to electrospray mass spectrometry (LC-ES-MS) with positive ion detection was used to determine abamectin in oranges. MS conditions were optimized to achieve maximum sensitivity. The main ion for abamectin was [M+Na]+ at a fragmentor voltage of 180 V. Abundant structural information can be obtained at different fragmentor voltages. The detection limit for the standard solution was 12 pg injected, and good linearity and reproducibility were observed. Abamectin residues were extracted using matrix solid-phase dispersion. Orange samples were homogenized with C18 bonded silica placed onto a glass column and eluted with dichloromethane. Recoveries of the abamectin from oranges fortified with approximately 0.01-10 mg/kg ranged from 94 to 99% with an overall average recovery of 96%. The quantification limit is 0.0025 mg/kg, which means detection limit for this analyte could be set at a few hundred picograms per gram of fruit. The presence in the electrosprayed solution of numerous citrus constituents did not interfere significantly with the ionization process of abamectin. The assay procedure provides a simple, rapid, and sensitive method for monitoring residues in oranges. The method was applied to field treatment orange samples.


Subject(s)
Chromatography, High Pressure Liquid/methods , Citrus/chemistry , Insecticides/analysis , Ivermectin/analogs & derivatives , Mass Spectrometry/methods , Ivermectin/analysis , Quality Control , Reproducibility of Results , Sensitivity and Specificity
19.
Dis Aquat Organ ; 62(1-2): 133-45, 2004 Nov 23.
Article in English | MEDLINE | ID: mdl-15648840

ABSTRACT

Cryptosporidium scophthalmi n. sp. is described from the turbot Scophthalmus maximus L., sampled from different farms on the coast of NW Spain. The parasite was found mainly in the intestinal epithelium and very seldom in the stomach. Oocysts were almost spherical, with 4 naked sporozoites and a residuum, and measured 3.7-5.03 x 3.03-4.69 microm (mean 4.44 x 3.91) (shape index 1.05-1.34, mean 1.14). Sporulation was endogenous, as fully sporulated oocysts were found within the intestinal epithelium, lumen and faeces. Merogonial and gamogonial stages were in the typical extracytoplasmic position, whereas sporogonial stages were deep within the epithelium. Oocysts and other stages of C. scophthalmi comply with most of the diagnostic features of the genus Cryptosporidium, but differ from all hitherto described species. Ultrastructural features, including the characteristic feeding organelle, were mainly comparable with those of other Cryptosporidium species. Mitochondria were frequently observed in sporozoites. Infection prevalence was very variable, and juvenile fish were most frequently and intensively parasitised. External clinical signs were not detected, although some fish showed intestinal distension at necropsy. The marked histopathological damage occurring in severe infection includes distension of epithelial cells by large vacuoles, containing clusters of oocysts, and can lead to sloughing of epithelial cell remnants and oocysts or even detachment of intestinal mucosa. An inflammatory reaction involving leucocyte infiltration was sometimes observed.


Subject(s)
Cryptosporidium/classification , Cryptosporidium/ultrastructure , Fish Diseases/pathology , Fish Diseases/parasitology , Flatfishes , Analysis of Variance , Animals , Aquaculture , Atlantic Ocean , Cryptosporidium/genetics , Histological Techniques , Intestinal Mucosa/parasitology , Intestinal Mucosa/pathology , Microscopy, Electron, Transmission , Oocysts/cytology , Spain , Species Specificity
20.
Cutis ; 50(1): 36-8, 1992 Jul.
Article in English | MEDLINE | ID: mdl-1516377

ABSTRACT

A forty-two-year-old male recipient of a cadaver renal transplant showed multiple nodulocystic lesions on his back and lateral aspects of his neck four months after beginning immunosuppressive therapy with cyclosporine A and prednisone. Results of histopathologic studies revealed that they were epidermoid infundibular cysts. We note the relationship between this clinical appearance and cyclosporine A, as well as this agent's cutaneous side effects.


Subject(s)
Cyclosporine/adverse effects , Epidermal Cyst/chemically induced , Kidney Transplantation , Skin Diseases/chemically induced , Adult , Cyclosporine/pharmacology , Epidermal Cyst/pathology , Humans , Male , Skin Diseases/pathology
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