Microalgal bioassays as a test of pesticide photodegradation efficiency in water.
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Analysis of Variance↗
Biomedical subjects
C Herrero
Publications and source records attributed to C Herrero.
Characterization of Galician (N.W. Spain) quality brand potatoes: a comparison study of several pattern recognition techniques.
Authenticity is an important food quality criterion and rapid methods to guarantee it are widely demanded by food producers, processors, consumers and regulatory bodies. The objective of this work was to develop a classification system in order to confirm the authenticity of Galician potatoes with a Certified Brand of Origin and Quality (CBOQ) 'Denominación Específica: Patata de Galicia' and to differentiate them from other potatoes that did not have this CBOQ. Ten selected metals were determined by atomic spectroscopy in 102 potato samples which were divided into two categories: CBOQ and non-CBOQ potatoes. Multivariate chemometric techniques, such as cluster analysis and principal component analysis, were applied to perform a preliminary study of the data structure. Four supervised pattern recognition procedures [including linear discriminant analysis (LDA), K-nearest neighbours (KNN), soft independent modelling of class analogy (SIMCA) and multilayer feed-forward neural networks (MLF-ANN)] were used to classify samples into the two categories considered on the basis of the chemical data. Results for LDA, KNN and MLF-ANN are acceptable for the non-CBOQ class, whereas SIMCA showed better recognition and prediction abilities for the CBOQ class. A more sophisticated neural network approach performed by the combination of the self-organizing with adaptive neighbourhood network (SOAN) and MLF network was employed to optimize the classification. Using this combined method, excellent performance in terms of classification and prediction abilities was obtained for the two categories with a success rate ranging from 98 to 100%. The metal profiles provided sufficient information to enable classification rules to be developed for identifying potatoes according to their origin brand based on SOAN-MLF neural networks.
Food Analysis↗
Morphoea in three siblings.
Atrophoderma of Pasini and Pierini (APP) is an uncommon form of localized morphoea that occurs as superficial, hyperpigmented plaques distributed mainly on the trunk and proximal part of the limbs. There is little information about the influence of genetic and environmental factors on disease susceptibility and expression for localized scleroderma, although APP familial cases have been reported. We report three siblings without a family history of autoimmune disease presenting cutaneous lesions suggesting morphoea (APP variant).
Adult↗
Association between serum concentrations of hexachlorobenzene and polychlorobiphenyls with thyroid hormone and liver enzymes in a sample of the general population.
OBJECTIVES: Hexachlorobenzene (HCB) is a highly lipophilic organochlorine compound of widespread environmental occurrence, that accumulates in the biological system. It affects the porphyrine metabolism, thyroid hormones, and the liver function in animals. Although HCB is one of the most common organochlorine compound in humans, little investigation on its health effects has been done. Polychlorobiphenyls (PCBs) are also widespread toxic environmental contaminants. The aim of the present study was to investigate the association of serum HCB and PCB concentrations with thyroid hormone status and liver enzymes in human. METHODS: Thyroid stimulating hormone (TSH), total and free thyroxine (T4), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) were measured as biological markers of thyroid and liver function in a rural population sample older than 14 years (n=192, except for TSH with n=608) highly exposed to HCB. Serum concentrations of HCB were measured by gas chromatography coupled to electron capture detection. RESULTS: After adjustment for confounding variables, there was a significant negative association between serum HCB concentrations and total T4 (a decrease of 0.32 microg/dl per each unit, ln ng/ml, of increase of HCB) and a positive association with GGT (a relative increase of 10 % per each ln unit of increase of HCB), although most subjects (92%) were within the normal range for both T4 and GGT. These associations were not modified after adjustment for total lipid content or for other organochlorine compounds. The association of T4 and GGT with PCB was smaller although significant. No association was found with the other biochemical markers. CONCLUSIONS: These results suggest that the internal dose of HCB of this population may reflect a subtle metabolic effect on thyroid function and an enzymatic induction activity. Further studies are needed to evaluate the health impact of these effects in more susceptible populations, such as infants.
Adolescent↗
IFN-gamma-dependent transcription of MHC class II IA is impaired in macrophages from aged mice.
To determine the effect of aging on IFN-gamma-induced MHC class II antigen expression, we produced bone marrow-derived macrophages in vitro. In these conditions, we analyzed the effect of aging on the genomic expression of macrophages without the influence of other cell types that may be affected by aging. Although macrophages from young and aged mice showed an identical degree of differentiation, after incubation with IFN-gamma, the expression at the cell surface of the IA complex and the levels of IAbeta protein and mRNA were lower in aged macrophages. Moreover, the transcription of the IAbeta gene was impaired in aged macrophages. The amount of transcription factors that bound to the W and X, but not to the Y, boxes of the IAbeta promoter gene was lower in aged macrophages. Similar levels of CIITA mRNA were found after IFN-gamma treatment of both young and aged macrophages. This shows that neither the initial cascade that starts after the interaction of IFN-gamma with the receptor nor the second signals involved in the expression of CIITA are impaired in aged macrophages. These data indicate that aging is associated with low levels of MHC class II gene induction by IFN-gamma because of impaired transcription.
Aging↗
The expression of MHC class II genes in macrophages is cell cycle dependent.
Using different drugs, we stopped the cell cycle of bone marrow-derived macrophages at different points. After IFN-gamma stimulation, macrophages arrested at the G(1) phase of the cell cycle did not increase cell surface expression of the MHC class II IA. This inhibition is specific, because, under the same conditions, IFN-gamma induces the expression of Fcgamma receptors and the inducible NO synthase mRNA. Treatments that inhibit macrophage proliferation by blocking the cell cycle at the G(1) phase, such as adenosine, forskolin, or LPS, blocked the IFN-gamma induction of IA. Under IFN-gamma treatment, the steady-state levels of IAalpha and IAss mRNA did not increase in cells arrested at the G(1) phase and the half-life of the MHC mRNA was not modified. These data suggest that the cell cycle modulation of IFN-gamma-induced MHC II gene expression occurs at the transcriptional level. The expression of the class II transactivator mRNA induced by IFN-gamma was also blocked when macrophages were arrested at the G(1) phase of the cell cycle, suggesting that the lack of IFN-gamma response occurs at the early steps of MHC class II expression. Finally, macrophages arrested at the G(1) phase showed increased basal levels of cell surface IA due to an increase of the translational efficiency. These data show that the expression of MHC class II genes is regulated by the cell cycle.
Animals↗
On-line LC-MS analysis of urinary porphyrins.
A reversed-phase high-performance liquid chromatography-mass spectrometry (LC-MS) method is described for the separation and simultaneous analysis of porphyrins related to disorders of heme biosynthesis (uro-, heptacarboxylic, hexacarboxylic, pentacarboxylic, and coproporphyrins). The method involves initial porphyrin esterification and extraction from urine. Detection and quantification is performed from the extracts by separation with a Hypersil BDS column and on-line detection by MS through coupling with an atmospheric pressure chemical ionization interface. The porphyrin esters are detected as protonated molecules [M + H]+. Their mass spectra also exhibit an [M + Na]+ fragment of lower intensity. The analytical performance of this method is compared with those of LC with UV and fluorescence detection. LC-MS used in selective [M + H]+ ion monitoring provides the lowest detection and quantitation limits. In scan mode, this LC-MS method affords, without further isolation or concentration steps, the measurement of mass spectra of unknown compounds present in the urine of patients with altered porphyrin excretion.
Chromatography, High Pressure Liquid↗
Potential use of flow cytometry in toxicity studies with microalgae.
Cytotoxic effects of aquatic pollutants on microalgae are very heterogeneous, and they are influenced by environmental conditions and the test species. Stress produced by copper or paraquat addition to the culture medium of two microalgae was analysed by flow cytometry. Parameters assayed were: cell volume, chlorophyll a fluorescence and cell viability. The variety of results obtained in the present study reveals that flow cytometry is a useful tool in the toxicity tests with microalgae, both marine and freshwater species, and for different kind of pollutants.
Cell Division↗
Papulonecrotic tuberculide in a human immunodeficiency virus type 1-seropositive patient.
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AIDS-Related Opportunistic Infections↗
Excretion of hexachlorobenzene and metabolites in feces in a highly exposed human population.
A set of 53 individuals from a population highly exposed to airborne hexachlorobenzene (HCB) were selected to study the elimination kinetics of this chemical in humans. The volunteers provided blood, 24-hr urine, and feces samples for analysis of HCB and metabolites. The serum HCB concentrations ranged from 2.4 to 1,485 ng/mL (mean +/- SD, 124 +/- 278), confirming that this human population has the highest HCB blood levels ever reported. All analyzed feces samples contained unchanged HCB (range, 11-3,025 ng/g dry weight; mean +/- SD, 395 +/- 629). The HCB concentration in feces strongly correlated with HCB in serum (r = 0.85; p < 0.001), suggesting an equilibrium in feces/serum that is compatible with a main pulmonary entrance of the chemical and low intestinal excretion of nonabsorbed foodborne HCB. The equilibrium is also compatible with a nonbiliary passive transfer of the chemical to the intestinal lumen. Two HCB main metabolites, pentachlorophenol (PCP) and pentachlorobenzenethiol (PCBT), were detected in 51% and 54% of feces samples, respectively. All urine samples contained PCP and PCBT, confirming the conclusions of a previous study [Environ Health Perspect 105:78-83 (1997)]. The comparison between feces and urine showed that whereas daily urinary elimination of metabolites may account for 3% of total HCB in blood, intestinal excretion of unchanged HCB may account for about 6%, thus showing the importance of metabolism in the overall elimination of HCB. The elimination of HCB and metabolites by both routes, however, appears to be very small (< 0.05%/day) as compared to the estimated HCB adipose depots. Features of HCB kinetics that we present in this study, i.e., nonsaturated intestinal elimination of HCB and excretion in feces and urine of inert glutathione derivatives, may explain, in part, the absence of porphyria cutanea in this human population heavily exposed to HCB.
Adolescent↗
[Clinical course of idiopathic inflammatory myopathies: complications, survival and prognostic factors].
OBJECTIVES: To describe the clinical and epidemiological characteristics, complications, survival and prognostic factors of a series of patients with idiopathic inflammatory myopathy (IIM) diagnosed with homogeneous criteria in the same center. PATIENTS AND METHODS: Patients with the diagnosis of IIM during an inclusion period of 20 years were studied. They were classified following the criteria of Bohan and Peter, and Dalakas. Epidemiological, clinical and therapeutical data were obtained in all cases. Evolution and survival were analyzed with the Kaplan-Meier and Cox multiple regression models. RESULTS: One-hundred thirty-five patients with IIM were included in the study: 32 polymyositis (PM), 90 dermatomyositis (DM) and 13 inclusion body myositis (IBM). Forty-six percent presented some complications attributed to the disease or treatment, and 10 with PM, 29 with DM and 3 with IBM died during the follow-up. The probabilities of survival were 86% the first year, 80% the second year, 71% the fifth year, and 57% the tenth year. Infections and cancer were the main death causes. While survival analyses did not show independent risk factors for PM, advanced age, presence of associated neoplasm, raised erythrocyte sedimentation rate (ESR) and muscle relapse were identified as a poor prognostic indicators for DM, whereas raised ESR and long lasting symptoms prior to diagnosis of the myopathy were for IBM. CONCLUSION: In spite of the therapeutic advances, IIM are still diseases with high mortality and morbidity.
Adult↗
Urinary porphyrin excretion in a human population highly exposed to hexachlorobenzene.
BACKGROUND: Data from an epidemic reported in Turkey (1955-1959) is the only information about the relationship between hexachlorobenzene (HCB) intake and porphyria cutanea tarda in humans. No information is available on the HCB threshold exposure level to induce porphyria cutanea tarda. OBJECTIVES: To study HCB serum levels and urinary porphyrin excretion in the inhabitants of a village located near an organochlorine compound factory with high HCB concentrations in the air and to detect possible alterations in urinary porphyrin excretion and examine their relationship with HCB serum levels. DESIGN: Cross-sectional study. SETTING: Unit of Porphyrias of a tertiary care facility in Barcelona, Spain. PARTICIPANTS: Six hundred four inhabitants of the village who were older than 14 years provided serum and urine samples (185 participants were factory workers). MAIN OUTCOME MEASURES: Serum HCB was analyzed by gas chromatography coupled to electron capture detection. Quantification of urinary total porphyrins was performed by spectrofluorimetry. Porphyrin profile was determined by high-pressure liquid chromatography. RESULTS: Hexachlorobenzene was detected in all serum samples (mean, 39.8 ng/mL; range, 1.1-1616.0 ng/mL), and levels were higher in factory workers. Mean +/- SD level urinary total porphyrin average concentration was 98 +/- 69 nmol/L (range, 9-1009 nmol/L). Only the urine sample with the highest porphyrin concentration showed an increase of highly carboxylated porphyrins, with a typical profile of porphyria cutanea tarda. In the remaining 603 urine samples, coproporphyrin was the predominant fraction. CONCLUSION: The airborne exposure to and increased body burden of HCB in the Flix village population are not enough to trigger a significant alteration of the heme biosynthesis pathway.
Adolescent↗
Set-Valued Utilities for Strict Partial Orders.
So far, only weak utility functions have been used to represent strict partial orders, but such a representation is not completely satisfactory, since we can not reconstruct the preference relation by simply knowing the weak utility function. The purpose of this paper is to present a type of numerical representation for strict partial orders, in such a way that recovering the preference relation is possible. Taking into account that (2(ℝ), superset) is a strict partial order, we consider set-valued utilities, namely, set-valued mappings, such that they admit a selection which is a weak utility function. Copyright 1999 Academic Press.
Journal Article↗
A comparison of the relative sensitivity of structural and functional cellular responses in the alga chlamydomonas eugametos exposed to the herbicide paraquat.
The effect of the herbicide paraquat on the freshwater microalga Chlamydomonas eugametos was studied in function of different parameters such as growth, elemental composition, total lipids, and photosynthetic pigments content and others assayed by flow cytometry (cell viability, cell volume, and granularity). The study reveals that paraquat concentrations above 0.15 microM are toxic for the microalga C. eugametos, inducing an inhibition of all the physiological parameters analyzed and strong structural changes. However, lower concentrations cause alterations in certain cellular components that are especially sensitive to the toxic action of the herbicide; so total lipids and photosynthetic pigments content are affected by concentrations such low as 0.037 microM. Taking into account these results, these parameters are better indicators of the cellular state than data on biomass or growth rate.
Analysis of Variance↗
Corticosteroid withdrawal after heart transplantation.
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Adrenal Cortex Hormones↗
Urinary porphyrin excretion measurements in healthy neonates.
The objective of this study was to establish normal reference ranges for porphyrins in healthy neonates. There is little information about urinary porphyrin excretion in this age group. This knowledge may provide an early diagnostic tool for detecting subtle alterations or latent forms in disorders of heme biosynthesis. Fifty healthy neonates were selected from the Department of Obstetrics. Total urinary porphyrins in random specimens were analysed by a spectrofluorometry method. The measurement of porphyrin fractions was made by fluorometric high-performance liquid chromatography (HPLC). The results were adjusted to urinary creatinine excretion to correct any imprecision and interindividual variation in body mass. The urinary total porphyrin had a median value of 331.50 (nmol/L). A statistically significant relationship between total porphyrin (nmol/L) and creatinine (mmol/L) was found (p < 0.01). The porphyrin/creatinine ratio showed a median value of 56.30 nmol/mmol creatinine. The study of individual porphyrins revealed that coproporphyrin and uroporphyrin were the major porphyrins excreted in neonates (coproporphyrin represents 81.98% and uroporphyrin 16.64% of total porphyrin); in both cases, isomer I was predominant with median values of 22.36 and 6.25 nmol/mmol creatinine, respectively. No significant relationships were found between porphyrin excretion and sex, gestational age, weight, or height. Our data provide the reference limits for porphyrins in neonates as a diagnostic guideline for evaluation of subtle alterations in heme biosynthesis.
Age Factors↗
[Open clinical trial with oral acyclovir for the prophylaxis of disease by Cytomegalovirus in low risk liver transplant recipients].
OBJECTIVE: Checking the first 70 low risk liver transplantation performed in our hospital, who did not receive prophylaxis for Cytomegalovirus, we found that the incidence of Cytomegalovirus-infection and Cytomegalovirus-disease were 47% and 16% respectively. METHODS: For this reason we started a prospective, open clinical study, to address the safety of acyclovir prophylaxis in low-risk liver transplant patients. Seventy patients did not receive acyclovir. Fifty patients received oral acyclovir during 3 months (800-3,200 mg/day). RESULTS: The occurrence of Cytomegalovirus infection was not modified (40%) but Cytomegalovirus disease decreased dramatically (4%, p < 0.01) during the first year after transplantation. Acyclovir was well tolerated. The incidence of leukopenia and renal failure were similar in both groups. Acyclovir did not improved the global survival of patients. CONCLUSIONS: Thus, oral acyclovir does not reduce Cytomegalovirus infection although it is efficient and safe in the prevention of Cytomegalovirus disease in low-risk liver transplantation, and prevents Herpes-simplex and Varicela-zoster symptomatic disease in this group of patients.
Acyclovir↗
Mutations in the ferrochelatase gene of four Spanish patients with erythropoietic protoporphyria.
Erythropoietic protoporphyria is a hereditary disorder of porphyrin metabolism caused by mutations in the ferrochelatase gene. Ferrochelatase catalyzes the chelation of ferrous iron into protoporphyrin IX to form heme. Mutation analysis was performed in four Spanish erythropoietic protoporphyria families resulting in the identification of four different mutations in the ferrochelatase gene. Two of them were novel mutations, a missense mutation (1157 A-->C, H386P) and a frameshift mutation (843delC) found in two Spanish families, respectively. The third and the forth Spanish patients carried already published ferrochelatase gene mutations, a nonsense mutation (343C-->T, R115X) and a missense mutation (557T-->C, I186T), respectively. The newly described frameshift mutation (843delC) predicted formation of an abrupt mRNA. The deleterious effect of His386 to Pro substitution as a result of mutation 1157 A-->C on the ferrochelatase activity was investigated by expressing the mutant ferrochelatase in Escherichia coli. The mutant ferrochelatase exhibited only 0.8% of the wild-type ferrochelatase activity. Prediction of the secondary structure of ferrochelatase suggested that the H386P mutation disrupted the original alpha-helical structure by way of introducing a turn, a rather drastic structural change of the enzyme sufficient to cause activity loss.
Electrophoresis, Polyacrylamide Gel↗