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D Romero

Publications and source records attributed to D Romero.

At least 19 recordsLinked to original sources
PubMed2006

Rapid growth of cartilage rudiments may generate perichondrial structures by mechanical induction.

Experimental and theoretical research suggest that mechanical stimuli may play a role in morphogenesis. We investigated whether theoretically predicted patterns of stress and strain generated during the growth of a skeletal condensation are similar to in vivo expression patterns of chondrogenic and osteogenic genes. The analysis showed that predicted patterns of compressive hydrostatic stress (pressure) correspond to the expression patterns of chondrogenic genes, and predicted patterns of tensile strain correspond to the expression patterns of osteogenic genes. Furthermore, the results of iterative application of the analysis suggest that stresses and strains generated by the growing condensation could promote the formation and refinement of stiff tissue surrounding the condensation, a prediction that is in agreement with an observed increase in collagen bundling surrounding the cartilage condensation, as indicated by picro-sirius red staining. These results are consistent with mechanical stimuli playing an inductive or maintenance role in the developing cartilage and associated perichondrium and bone collar. This theoretical analysis provides insight into the potential importance of mechanical stimuli during the growth of skeletogenic condensations.

Animals↗
PubMed2006

Comparison of chromaffin cells from several animal sources for their use as an in vitro model to study the mechanism of organophosphorous toxicity.

It had been observed that the chromaffin cells of bovine adrenal medulla contain high levels of neuropathy target esterase (NTE), the esterase whose inhibition and aging is associated with induction of the organophosphorous induced delayed neuropathy. In this study, total esterase and NTE activities, and their inhibition kinetics by OPs are characterized in adrenal medulla of several species in order to find the best source for chromaffin cells. Total esterase activity in membrane fraction of bovine, equine, porcine, ovine and caprine were 6100+/-840, 4200+/-270, 5000+/-120, 28800+/-3000, and 10800+/-2400mU/gtissue, respectively (mean+/-S.D., n=3-4). NTE represented around 70%, 24%, 58%, 10% and 24% of the total esterases in the same tissues, respectively. It was deduced that NTE represents between 69% and 89% of the "B-activity" (activity resistant to 40microM paraoxon) in the membrane fraction of all species. The mipafox I(50) calculated for 30-min inhibition of NTE at 37 degrees Celsius ranged between 7.4 and 12microM. These values are in the range of that for brain NTE in hen (the usual model for testing OP delayed neurotoxicity). Considering that bovine adrenal medulla contains high NTE activity, that it represents a high proportion of total activity, it is easier to dissect than adrenal medulla from equine, caprine or ovine, and is more readily available than species cited previously, and that its inhibitory properties are similar to the classical hen brain model, it is deduced that bovine adrenal medulla is the most appropriate source of chromaffin cells to study OP toxicity, with porcine as the second alternative. The kinetic properties of chromaffin cell cultures from bovine and porcine were in accordance with their properties in homogenate and subcellular fractions, and they displayed an appropriate stability and viability of the primary culture to be used in in vitro toxicological studies for both mechanistic and testing purposes.

Animals↗
PubMed2006

Eosinophilic ulcer of the oral mucosa: another histological simulator of CD30+ lymphoproliferative disorders.

Eosinophilic ulcer of the oral mucosa (EUOM), also known as traumatic ulcerative granuloma with stromal eosinophilia or Riga-Fede disease, is an uncommon benign self-limited lesion poorly described in the dermatological literature. It probably includes a spectrum of related disorders presenting as an ulcer with elevated indurated borders affecting the tongue, oral mucosa or lip. Histopathological findings are characteristic and consist of eosinophil-rich mixed infiltrates accompanied by a population of large mononuclear cells whose origins have been a matter of debate. Immunohistochemical studies of these cells have suggested a myofibroblastic or histiocytic origin. We present a 93-year-old woman with two episodes of self-healing ulcers on the upper lip and on the lingual mucosa, respectively. Histopathological findings on both biopsies were consistent with EUOM and showed the presence of large atypical CD30+ lymphocytes. Some recent reports have also shown positivity for the CD30 antigen, raising the possibility that a subset of EUOM could be included within the spectrum of CD30+ lymphoproliferative disorders. This finding most likely suggests that EUOM can represent another histological simulator of CD30+ lymphoproliferative disorders.

Aged, 80 and over↗
PubMed2005

High levels of blood lead in griffon vultures (Gyps fulvus) from Cazorla Natural Park (southern Spain).

The blood lead of 23 griffon vultures (Gyps fulvus) trapped in 2003 was analyzed in order to evaluate exposure to lead in the vulture population of Cazorla Natural Park (in southern Spain). In 2001 the use of leaded gasoline in vehicles was banned in the European Union; however, lead ammunition is still used in Spain in big-game hunting for red deer, fallow deer, mouflon, and wild boar, which are ingested by vultures from September to March. The mean concentration of lead in blood was 43.07 +/- 31.96 microg/dL with a range of 17.39-144.80 microg/dL. Only two vultures had lead levels below 20 microg/dL, and two others had blood lead concentrations close to 150 microg/dL. In view of the results, we think the population of vultures from Cazorla Natural Park is suffering subclinical exposure to lead, with some individuals exposed to high toxicity risk. We concluded that ingestion of lead in the metallic form alone is sufficient to produce these blood lead concentrations, and we recommend the prohibition of lead ammunition for big-game hunting in order to preserve the vulture population.

Animals↗
PubMed2004

Morphological characterization of renal cell lines (BGM and VERO) exposed to low doses of lead nitrate.

The response to lead nitrate has been assessed in two cell lines of renal origin. The range of toxic concentrations was determined by Neutral Red assay after 24-h of exposure. Morphological changes in the Buffalo Green Monkey (BGM) and VERO cell lines after exposure to subcytotoxic doses (1.38 mM and 1.04 mM, respectively) equivalent to EC10 (effective concentrations 10%) of lead nitrate were evaluated at the ultrastructural level by transmission microscopy. The most notable finding in treated cells was the presence of inclusion bodies in the form of irregular granules of varying size in both cytoplasm and lysosomes. Cell membrane integrity was not affected. The number of phagolysosomes and myeline figures associated to the inclusion bodies was higher than in the control cultures. We conclude that the phagolysosomic mechanism fails to digest this metal ion and the BGM and VERO renal cell lines can be considered as useful tools for toxicological studies involving lead nitrate.

Animals↗
PubMed2003

Isolation and evaluation of antagonistic bacteria towards the cucurbit powdery mildew fungus Podosphaera fusca.

Powdery mildew is one of the most important limiting factors for cucurbits production in Spain, its management being strongly dependent on chemicals. The aim of this work was to evaluate the possibility of exploiting antagonistic bacteria in the biological control of the cucurbit powdery mildew fungus Podosphaera fusca (syn. Sphaerotheca fusca). Among a collection of bacterial strains isolated from distinct cucurbit powdery mildew diseased plants and rhizospheric soils, four isolates were selected, by means of a screening method based on antibiotic production, and identified as Bacillus spp. These isolates proved to be efficacious in the control of cucurbit powdery mildew in in vitro detached leaves and seedling biocontrol assays, where reductions of disease severity of up to 80% were obtained. Furthermore, bacterial populations on melon leaves remained at similar levels (10(5) cfu cm(-2)) over the 16-day period studied and, as observed by scanning electron microscopy analysis, they were able to establish microcolonies associated with an extracellular matrix, which reveals that these isolates efficiently colonize melon phylloplane. These results indicate that the bacterial isolates selected are promising candidates for biological control agents of cucurbit powdery mildew in southern Spain.

Antibiosis↗
PubMed2003

Remote, real-time, on-line monitoring of high-temperature samples by noninvasive open-path laser plasma spectrometry.

A remote detection system based on optical emission spectrometry of laser-induced plasmas has been developed to record spectra in the visible region from samples placed at remote distances from the excitation source. Unlike from fiber-optic-based systems, light collection is performed remotely as well. Laboratory-scale experiments have shown the possibility of performing real-time analysis of samples placed remotely. The application in the noninvasive analysis of hot samples (at 1,200 degrees C) has been demonstrated as well, allowing the dynamic monitoring of selective elemental migration.

Journal Article↗
PubMed2003

Morphological characterisation of BGM (Buffalo Green Monkey) cell line exposed to low doses of cadmium chloride.

Morphological changes in the Buffalo Green Monkey (BGM) cell line after exposure to a subcytotoxic dose (0.062 mM, equivalent to EC(10)-effective concentration 10%) of cadmium chloride have been evaluated. Cells were exposed for 24 h and the effects observed at the ultrastructural level by transmission and scanning microscopy. Using transmission electron microscopy, the most notable findings in treated cells were the presence of intranuclear inclusion bodies and thin intracytoplasmic granules associated to myelin figures and the presence of apoptotic bodies. Other morphological alterations included cell vacuolisation and a reduced cytoplasm volume, condensation of the mitochondria and a decreased number of cytoplasmic organelles, except lysosomes and autophagic vacuoles, which increased in number. Scanning electron microscopy pointed to a cell with a disrupted perinuclear region and a decrease in the number of surface microvilli. We conclude that the BGM cell line may be considered an useful tool for toxicological studies involving cadmium.

Animals↗
PubMed2003

Intentional poisoning of animals in southeastern Spain: a review of the veterinary toxicology service from Murcia, Spain.

Data of toxicological analyses carried out over a 10-y period for suspected cases of wild and domestic animal poisonings are summarized. Of the 123 cases suspected as deliberate, 102 were be analyzed and 50 of them were positive to intentional poisoning, a total of 107 dead animals. Pesticides, especially insecticides (72%) and rodenticides (26%), were frequently involved. Aldicarb (n=15), anticoagulant rodenticides (n=8) and strychnine (n=4) were the most common toxins in baits prepared for intentional poisonings; carbofuran, methomyl, endosulfan and paraquat were also used. A coordinated Veterinary Toxicology Services network of collaboration should be set up in Spain to improve the quality of the services provided.

Aldicarb↗
PubMed2002

Personal exposure to benzene, toluene and xylene in different microenvironments at the Mexico City metropolitan zone.

The Mexico City Metropolitan Zone (ZMCM) population's exposure to benzene, toluene and xylene was measured at different microenvironments to establish basic indicators of the presence and effects of these characteristic volatile organic compounds (VOC). In particular, VOC personal exposures were measured in different microenvironments during a 5-day working week, with 12-h daily periods. We have found a good agreement of our results with the registered VOC levels of the Metropolitan Automated Monitor System (RAMA) for the corresponding period. From our results, we expect to generate useful information to evaluate the health effects of these VOCs on exposed people.

Automation↗
PubMed2002

Feasibility, reliability and validity of the Spanish version of Psychiatric Assessment Schedule for Adults with Developmental Disability: a structured psychiatric interview for intellectual disability.

BACKGROUND: Over 30% of people with intellectual disability (ID) have a comorbid psychiatric disorder. However, there are few assessment instruments available for international use and cross-cultural validation studies of these instruments are rare. The aim of the present study was to standardize the Spanish version of the Psychiatric Assessment Schedule for Adults with Developmental Disability (PAS-ADD-10), a semi-structured interview for people with ID. METHODS: After a conceptual translation, feasibility (i.e. applicability, acceptability and practicality) and reliability analyses were carried out. The predictive validity of the PAS-ADD-10 CATEGO-5 codings was also examined (i.e. positive and negative predictive values). Four independent raters with wide-ranging experience in quantitative evaluation and psychiatric assessment of ID evaluated a sample of 80 subjects with ID and borderline intellectual functioning at the AFANAS occupational centre in Jerez, Southern Spain. The ICD-10 codes were used for psychiatric diagnosis. RESULTS: The practicality of the PAS-ADD-10 is limited because of the need for previous standardization of SCAN interviews. Nevertheless, its overall feasibility was judged adequate by raters and the PAS-ADD-10 was considered extremely useful for training. Test-retest and inter-rater reliability kappa values were moderate to high. The CATEGO coding showed limited validity because of overdiagnosis of anxiety disorders and underdiagnosis of mood and psychotic disorders (positive predictive value = 74%, negative predictive value = 76%). CONCLUSIONS: The PAS-ADD-10 is a useful tool for standard psychiatric assessment of people with ID; however, CATEGO codings show low validity and a series of modifications should be considered before this instrument is used extensively in Spain. In this regard, a study on the clinical usefulness of the PAS-ADD-10 in patients with ID and severe mental disorders has been undertaken.

Adolescent↗
PubMed2002

Changes in glutathione-redox balance induced by hexachlorocyclohexane and lindane in CHO-K1 cells.

1. The basal cytotoxic effect of the organochlorine pesticides hexachlorocyclohexane and lindane on CHO-K1 cultures was assessed at fractions of their lethal doses as determined by the neutral red incorporation (NRI) assay (NRI(6.25), NRI(12.5) and NRI(25)). The sulphur-redox cycle enzymes glutathione peroxidase, glutathione reductase and glutathione S-transferase, and total and oxidized glutathione were evaluated at several points during the standard growth curve of the cultures. 2. After incubation with each compound for 24 h, both glutathione peroxidase and reductase showed a substantial increase at the lowest exposure doses (NRI(6.25))--more significantly for lindane than for 1,2,3,4,5,6-hexachlorocyclohexane (HCH)--and dropped at higher doses of both compounds. The reduced and oxidized glutathione content was greatly diminished at the lower exposures, whereas the total glutathione content was higher at NRI(12.5) values. 3. Changes in cell membrane integrity were assessed for a wide range of pesticide concentrations with the lactate dehydrogenase release assay and lipid peroxidation. Membrane leakage and peroxide production were significantly enhanced at concentrations of HCH 50 microg ml(-1), although this effect was not significant at lindane concentrations < 200 microg ml(-1). 4. Lipid peroxidation increased with exposure to HCH at concentrations as low as NRI(6.25), whereas in the case of lindane, this increase was only significant at doses of NRI(25) and above.

Animals↗
PubMed2001

Time-resolved laser-induced plasma spectrometry for determination of minor elements in steelmaking process samples.

A pulsed Nd:YAG laser operating on the fourth (266 nm) and second (532 nm) harmonics has been used to generate plasmas on the target surface in air at atmospheric pressure. The influence of wavelength on quantitative analysis of 4 minor elements in stainless steel samples (Si, Ti, Nb and Mo) was investigated. Stainless steel samples with different elemental concentrations were prepared and analyzed by laser-induced plasma spectrometry (LIPS). The effect of laser wavelength on analytical figures of merit (calibration curves, correlation coefficients, linear dynamic ranges, analytical precision, and accuracy values) was found to be negligible when internal standardization (an Fe line) and time-resolved laser-induced plasma are employed. For both wavelengths, the calibration curves presented a good linearity and an acceptable linear dynamic range in the concentration interval investigated. For the four elements studied, limits of detection lower than 150 microg g(-1) were achieved. To evaluate the influence of wavelength on precision and accuracy, a set of fifteen high-alloyed steel samples from different stages of steelmaking process have been analyzed. Finally, the long-term stability of the analytical measurements for Mo with 532 nm wavelength has been discussed. RSD values were lower than 5.3% for the elements studied.

Journal Article↗