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M Sancho

Publications and source records attributed to M Sancho.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of the electric field induced forces in erythrocyte membrane pores using a realistic cell model.

We calculate the induced electric stress forces on transient hydrophobic pores in the membrane of an erythrocyte exposed to an electric field. For this purpose, we use a finite element numerical technique and a realistic shape for the biconcave erythrocyte represented by a set of parametric equations in terms of Jacobi elliptic functions. The results clearly show that the electrical forces on the base and sidewalls of the pore favour the opening of the pore. A comparison of the force densities obtained for an unstretched flat membrane and for the realistic erythrocyte model shows that the thinning and curvature of the membrane cannot be neglected. We also show that the pore deformation depends strongly on the orientation of the pore with respect to the external field, and in particular is very small when the field is tangent to the membrane surface.

Biomechanical Phenomena↗
PubMed2006

Modeling normal and altered human erythrocyte shapes by a new parametric equation: application to the calculation of induced transmembrane potentials.

We present simple parametric equations in terms of Jacobi elliptic functions that provide a realistic model of abnormal variations in size which maintain the biconcave shape of a normal erythrocyte (anisocytosis) and abnormal variations in shape which maintain the original volume of the erythrocyte (poikilocytosis), as well as continuous deformations from the normal to the altered shapes. We illustrate our results with parameterizations of microcytes, macrocytes, and stomatocytes, and we apply these parameterizations to the numerical calculation of the induced transmembrane voltage in microcytes, macrocytes, and stomatocytes exposed to an external electromagnetic field of 1800 MHz.

Electromagnetic Phenomena↗
PubMed2005

Comparison of three different staining methods for the assessment of epididymal red deer sperm morphometry by computerized analysis with ISAS.

When collection of ejaculated sperm samples is not possible, as is the case with wild species, the epididymides of sacrificed wild males become the only possible source of spermatozoa. Mature cauda epididymal spermatozoa display characteristics similar to those of ejaculated sperm cells. The present work proposes a sperm staining technique suitable for the morphometric evaluation of red deer epididymal sperm using a new computerized system. Epididymides from wild animals were extracted no later than 2h post mortem. After epididymal sectioning, sperm samples were collected, cooled to and equilibrated at 5 degrees C, and frozen in liquid nitrogen. Before staining, sperm samples were thawed for 20s at 37 degrees C, and used for the preparation of slides. Three different sperm stains were tested: Hemacolor, Diff-Quik, and Harris' Hematoxylin. Morphometric analyses of sperm samples were performed using the morphologic module of the ISAS. Two hundred spermatozoa per sample and stain were captured at random and analyzed. Sperm morphometric values were significantly affected by the staining technique used. Moreover, significant differences were observed between animals. In our study, Diff-Quik could be considered to be the best sperm staining method, as it provided the highest percentage of well automatically analyzed cells by the ISAS, and discriminates better between animals. This sperm staining technique also proved to be a useful method for characterizing and discriminating between sperm samples of different animals.

Animals↗
PubMed2005

Effect of solid storage at 15 degrees C on the subsequent motility and fertility of rabbit semen.

We conducted two studies to improve preservation of rabbit semen. The objective of the first study was determine whether a glucose- and fructose-based extender with two different amounts of gelatin would solidify at 15 degrees C, and to evaluate the influence of gelatin supplementation on sperm motility parameters after storing semen up to 10 days at 15 degrees C. The fertility of rabbit semen diluted in the best gelatin-supplemented extender established in Study 1 and stored for up to 5 days was evaluated in the second study. In Study 1, semen was collected with an artificial vagina from 40 bucks. Each ejaculate was diluted to (80-100) x 10(6) spermatozoa/mL (1:3, semen/extender) at 37 degrees C in one of the three following glucose- and fructose-based extenders: control (standard liquid extender), semi-gel or gel (0.7 or 1.4 g gelatin in 100 mL extender, respectively). Pools of semen were allocated among 0.6 mL plastic artificial insemination (AI) guns. Thirty (10 per extender group) AI doses were immediately analyzed (0 h) and the remainder stored in a refrigerator (15 degrees C) for 12, 24, 36, 48, 72, 96, or 240 h. All doses with gelatin extenders solidified at 15 degrees C. Semen samples, prewarmed to 37 degrees C, were evaluated with a computer-assisted sperm analysis (CASA) system. The percentage of motile cells was significantly lower using the liquid compared to the gel extenders during semen storage from 0 to 96 h. Although significance was lost, these differences persisted after 240 h of storage. Motility of spermatozoa in the semi-gel extender was intermediate between that of liquid and gel extender throughout the study. Study 2 was performed on 1250 multiparous lactating does. Five homogeneous groups of 250 does previously synchronized were inseminated using semen previously stored for 120, 96, 72, 48 or 24 h, respectively. Rabbit does receiving 24 h-stored semen (diluted with the control extender used in Study 1) served as controls. The remaining females received seminal doses supplemented with 1.4 g/100mL gelatin (gel extender used in Study 1). Kindling rates for rabbit does inseminated with gelatin-supplemented (solid) semen doses stored for 48 h (88%) or 72 h (83%) were similar to those recorded for liquid controls stored for 24 h (81%), whereas rates significantly decreased when the semen was solid and stored for 96 h (64%) or 120 h (60%) before AI. In conclusion, rabbit spermatozoa were effectively stored in the solid state at 15 degrees C, with fertility preserved for up to 5 days. Solid storage of rabbit semen would facilitate commercial distribution.

Animals↗
PubMed2005

Latex agglutination for bacterial antigens and meningococcus PCR: two useful tools in legal sudden deaths.

Bacterial infections are considered to be a major cause of sudden deaths. The recognition of infections caused by Neisseria meningitidis is an essential duty of medicolegal offices due to the risk of secondary cases. Since other microorganisms, such as Haemophilus influenzae and Streptococcus pneumoniae, are also involved in infectious sudden deaths, the identification of the pathogen responsible for death is essential in order to establish a positive diagnosis while also preventing secondary meningococcal cases. However, because of the unreliability of culture methods used for autopsy specimens and the fragile nature of the microorganisms, other techniques were used. In this study, the detection of specific antigens of N. meningitidis (serogroups A, B, C, Y and W135), H. influenzae type b, S. pneumoniae and Group B Streptococcus was undertaken in 40 samples from sudden death cases in legal procedures with a latex agglutination test. In addition, a meningococcus polymerase chain reaction (PCR) assay (ctrA, crgA and siaD genes) was also used as a corroboration method for positive N. meningitidis agglutinations. Eleven cases of sudden death were confirmed to be due to meningococcus while one case was confirmed to have been caused by H. influenzae type b fulminant epiglottitis. Rapid laboratory diagnosis of meningococcal infection allowed contacts management and notification to the health authorities. From the point of view of the authors, forensic diagnosis of unascertained deaths should include latex agglutination and meningococcus PCR when a fulminant infection by N. meningitidis or H. influenzae is suspected as well as in deaths where the cause is unclear.

Adolescent↗
PubMed2005

Declassification of radioactive liquid wastes generated in radio immune assay [corrected] (RIA) laboratories.

Radioactive liquid wastes of low-medium activity level are generated in radio immune assay (RIA) laboratories, which are also potentially infectious because of the pathogens from patient blood. The most common way of managing these wastes consists of a temporal storage, for partial radioactivity decay, followed by management by an authorised company. The object of this work is to study the viability of treating radioactive liquid wastes coming from RIA using membrane techniques in order to reduce their volume, which would mean an improvement from the radiological point of view and a decrease in management costs. This paper describes the results of some experiments carried out with RIA real wastes, by means of processes such as ultrafiltration and reverse osmosis. It has been proved that waste volume can be significantly reduced, obtaining a treated liquid that is free of pathogens and organic matter and with an activity level around the environmental background.

Laboratories, Hospital↗
PubMed2005

Regionalization of epididymal duct and epithelium in rats and mice by automatic computer-aided morphometric analysis.

AIM: To establish a rat and mouse epididymal map based on the use of the Epiquatre automatic software for histologic image analysis. METHODS: Epididymides from five adult rats and five adult mice were fixed in alcoholic Bouin's fixative and embedded in paraffin. Serial longitudinal sections through the medial aspect of the organ were cut at 10 microm and stained with hematoxylin and eosin. As determined from major connective tissue septa, nine subdivisions of the rat epididymis and seven for the mouse were determined, consisting of five sub-regions in the caput (rat and mouse), one (mouse) or three (rat) in the corpus and one in the cauda (rat and mouse). Using the Epiquatre software, several tubular, luminal and epithelial morphometric parameters were evaluated. RESULTS: Statistical comparison of the quantitative parameters revealed regional differences (2-5 in the rat, 3-6 in the mouse, dependent on parameters) with caput regions 1 and 2 being largely distinguishable from the similar remaining caput and corpus, which were in turn recognizable from the cauda regions in both species. CONCLUSION: The use of the Epiquatre software allowed us to establish regression curves for different morphometric parameters that can permit the detection of changes in their values under different pathological or experimental conditions.

Animals↗
PubMed2005

Mitochondrial DNA haplotyping revealed the presence of mixed up benign and neoplastic tissue sections from two individuals on the same prostatic biopsy slide.

DNA typing was requested to investigate a presumptive cancer diagnosis error by confirming whether benign and cancerous prostatic tissue in the same presurgical haematoxylin and eosin stained slide belonged to the same person. After independent histological re-examination of the slide by a pathologist, manual slide dissection was used to guarantee independent and high recovery DNA isolation from each tissue section, avoiding carryover and background contamination. Nuclear DNA quantification performed by real time polymerase chain reaction (PCR) revealed the absence of human DNA for short tandem repeat (STR) typing. Mitochondrial DNA was only obtained by performing PCR of very short fragments ( approximately 100 bp), indicating high DNA degradation. Different low frequency hypervariable region I haplotypes were obtained from each tissue section (normal tissue section haplotype: 16224C, 16234T, 16311C, 16356C; cancer tissue section haplotype: 16256T, 16270T, 16293G). Only the normal tissue section haplotype matched that obtained from the patient's blood sample, indicating that the cancer tissue section originated from an unknown patient. These results supported the hypothesis of sample mix up during block processing or slide preparation by a carryover mechanism. Mitochondrial genetic typing is recommended to exclude the possibility of carryover artefacts when low DNA content and high degradation compromise conventional STR typing.

Artifacts↗
PubMed2004

Transmembrane voltage induced on altered erythrocyte shapes exposed to RF fields.

In this article, the transmembrane voltage induced on erythrocyte, codocyte, ovalocyte and spherocyte cell models exposed to a linearly polarised electromagnetic plane wave of frequency 1800 MHz is calculated. For this purpose, a finite element (FE) numerical technique with adaptive meshing is used. The results show that the value of the induced voltage on the original erythrocyte shape is higher than the one observed on the rest of the altered cell geometries studied. The erythrocyte shape and the membrane electric permittivity are shown to play a fundamental role on the values of the induced transmembrane voltage.

Animals↗
PubMed2004

Modelling the internal field distribution in human erythrocytes exposed to MW radiation.

This paper studies the internal electric field distribution in human erythrocytes exposed to MW radiation. For this purpose, an erythrocyte cell model is exposed to linearly polarized electromagnetic (EM) plane waves of frequency 900 MHz and the electric field within the cell is calculated by using a finite element (FE) technique with adaptive meshing. The results obtained show the dependence of the induced electric field distribution on the main modelling parameters, i.e., the electrical properties (permittivity and conductivity) of the membrane and cytoplasm and the orientation of the cell with respect to the applied field. It is found that for certain orientations, the field amplification within the membrane of the erythrocyte shape cell can be higher than the one observed in an equivalent simple spheroidal geometry cell, commonly used in bioelectromagnetism. The present work shows that a better insight of the interaction of electromagnetic fields with basic biological structures is obtained when the most possible realistic cell shape is used.

Cell Membrane↗
PubMed2003

A study of the electric field distribution in erythrocyte and rod shape cells from direct RF exposure.

This paper shows the importance of using realistic cell shapes with the proper geometry and orientation to study the mechanisms of direct cellular effects from radiofrequency (RF) exposure. For this purpose, the electric field distribution within erythrocyte, rod and ellipsoidal cell models is calculated by using a finite element technique with adaptive meshing. The three cell models are exposed to linearly polarized electromagnetic plane waves of frequencies 900 and 2450 MHz. The results show that the amplification of the electric field within the membrane of the erythrocyte shape cell is more significant than that observed in other cell geometries. The results obtained show the dependence of the induced electric field distribution on frequency, electrical properties of membrane and cytoplasm and the orientation of the cell with respect to the applied field. The analysis of the transition of an erythrocyte shape to an ellipsoidal one shows that a uniformly shelled ellipsoid model is a rough approximation if a precise simulation of bioeffects in cells is desired.

Animals↗
PubMed2003

Use of the Sperm-Class Analyser for objective assessment of human sperm morphology.

The Sperm-Class Analyser was validated for assessing morphometric parameters of the head and midpiece of unwashed and washed human ejaculated spermatozoa from volunteers providing a wide range of semen quality. A higher proportion of sperm could be assessed (86% fresh semen and 75% washed sperm) if Hemacolor staining was used rather than DiffQuik (80 and 73%) or Papanicolaou (78 and 68%). Different stains employed different fixatives and the area, length, width and perimeter of the sperm head was significantly larger for washed sperm stained by Hemacolor and DiffQuik. Acrosomal area ranged from 48 to 51% of the sperm head area and this percentage was larger for washed sperm stained with DiffQuik. Sperm at the end of the slide, distant from the initial semen droplet, were larger in area and perimeter than those at that site or in the middle. The high precision and reproducibility of the equipment required assessing only 50 sperm on the slide. Far greater variation was found in head width, relative acrosomal area and midpiece width between different slides prepared from the same ejaculate, highlighting the inherent variability within the ejaculate and smear preparation, and requiring more than one slide to be assessed.

Adult↗
PubMed2002

[Midfacial necrosis secondary to cocaine-abuse].

Midfacial necrosis due to the abuse of inhaled cocaine is a new entity that is included in the differential diagnosis of the midline destructive diseases such as Wegener's granulomatosis, polymorphic reticulosis, nasal lymphoma, infections and the idiopathic midline destructive disease. We report the case of a forty-year-old male who presented necrosis of the nasosinusal tract and optic neuropathy as complications due to the abuse of inhaled cocaine for more than twenty years and a discussion about the differential diagnosis.

Adult↗
PubMed2001

Analysis of the influence of the cell geometry, orientation and cell proximity effects on the electric field distribution from direct RF exposure.

This paper shows the importance of using a cell model with the proper geometry, orientation and internal structure to study possible cellular effects from direct radiofrequency exposure. For this purpose, the electric field intensity is calculated, using the finite element numerical technique, in single- and multilayer spherical, cylindrical and ellipsoidal mammalian cell models exposed to linearly polarized electromagnetic plane waves of frequencies 900 and 2450 MHz. An extensive analysis is performed on the influence that the cell geometry and orientation with respect to the external field have in the value of the electric field induced in the membrane and cytoplasm. We also show the significant role that the cytoplasmic and extracellular bound water layers play in determining the electric field intensity for the cylindrical and ellipsoidal cell models. Finally, a study of the mutual interactions between cells shows that polarizing effects between cells significantly modify the values of field intensity within the cell.

Cell Membrane↗
PubMed2001

DNA typing from skeletal remains: evaluation of multiplex and megaplex STR systems on DNA isolated from bone and teeth samples.

AIM: To evaluate the performance of three multiplex short tandem repeat (STR) systems (AmpflSTR Profiler, AmpflSTR Profiler Plus, and AmpflSTR COfiler), and a megaplex STR system (PowerPlex 16) on DNA extracted from the skeletal remains. By performing a microbial DNA challenge study, we also evaluated the influence of microbial DNA on human DNA typing. METHODS: A subset of 86 DNA extracts isolated from 8-50 years old bone and teeth samples, corresponding to 20 identification cases from mass graves in Croatia and Bosnia and Herzegovina, and to 4 paternity cases involving deceased parents in Spain, were analyzed by the above systems. RESULTS: Bone samples with no detectable human DNA (tested with Quantiblot), as well as teeth samples with detectable human DNA, were successfully amplified. Surprisingly, even in highly degraded samples, PowerPlex 16 offered very robust amplification for the both Penta E and Penta D markers. We observed a few non-specific extra peaks of 202 and 308 base pairs, which appeared to match 16S rRNA of the Pseudomonas halodenitrificans. CONCLUSION: AmpflSTR Profiler Kit, AmpflSTR Profiler Plus Kit, the AmpflSTR COfiler Kit, and the PowerPlex 16 system are very sensitive multiplex STR amplification systems, which can be successfully used to obtain a multilocus STR profile from old teeth and bone samples with minimal amounts (pg) of human DNA or even with no detectable human DNA.

Bone and Bones↗
PubMed2000

[Allergic fungal sinusitis].

Allergic fungal sinusitis is a recently described clinical entity that has gained increased attention as a cause of chronic sinusitis. Consist in a benign noninvasive sinus disease related to a hypersensitivity reaction to fungal antigens. It should be suspected in any atopic patient with refractory nasal polyps. Computed tomography (CT) findings are characteristics, but not diagnostic. Diagnosis requires show allergic mucin in the histopathologic examination and hiphae in special fungal stains. The suitable treatment includes the allergic mucin removal and sinus aeration accomplished endoscopically, perioperative systemic steroids and immunotherapy with fungal antigens. We present a case of this kind of chronic sinusitis describing the characteristic histopathologic and radiologic findings, the pathogenic theories and recent advances in immunotherapy.

Adolescent↗
PubMed1999

Spanish population data on the four STR loci D8S1179, D16S539, D18S51 and D21S11.

Population data were generated for four tetrameric short tandem repeat loci systems (D8S1179, D16S539, D18S51 and D21S11) for a Spanish Caucasian population sample (n = 218-219 individuals) using PCR. All loci were highly polymorphic, met Hardy-Weinberg expectations and the results demonstrated the assumption of independence of the loci analysed. The allele frequency data can be used in identity testing to estimate the frequency of a multiple PCR-based DNA profile in the Spanish population.

Alleles↗