P Sanz

Instituto Nacional de Toxicología y Ciencias Forenses, Madrid, Madrid, Spain

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Publications (47)60.91 Total impact

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    ABSTRACT: El concepto multidisciplinar de Ciencias Forenses se ha consolidado en los últimos años integrando un amplio espectro de profesionales de distintas disciplinas que ha abierto nuevas áreas de trabajo, en la mayoría de las cuales la interpretación del resultado se basa en la comparación con un material de referencia. Este trabajo pretende exponer brevemente una revisión de la casuística de Delitos Contra la Libertad Sexual (DCLS) estudiados en los laboratorios de Biología Forense y evaluar el rendimiento de la prueba de ADN a lo largo de los años en dos aspectos: uno en las situaciones inherentes a la metodología y otro en lo que respecta al cotejo de los vestigios analizados con las muestras de referencia de los implicados. En este segundo supuesto, el no disponer de una Base de Datos Nacional de Perfiles de ADN parece ser una de las razones en la no resolución de algunos de estos casos. Desde la denuncia del delito perpetrado hasta la obtención del ansiado perfil de ADN susceptible de cotejo intervienen múltiples factores, algunos de los cuales podrían ser controlados-consensuados desde instituciones como los Institutos de Medicina Legal (IMLs) de quienes depende la toma, distribución y envío de las muestras y otros deberían ser previstos-consensuados en los propios laboratorios de análisis.
    Cuadernos de Medicina Forense 01/2007;
  • Y. Torres, P. Sanz
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    ABSTRACT: Allelic mixtures cannot be detected in some evidences depending on the commercial kit used. The variability in the detection of mixed profiles with four multiplexes of a same manufacturer in the same DNA extracts of casework samples was analysed. SGMPlus™ has showed the best results in allelic mixture detection and Identifiler™ has showed to be the less useful. The criteria to determine if results have sufficient intensity and quality for mixture interpretation should be included in the validation process in the laboratories and, if necessary, to define the best multiplexes in typing casework samples to improve mixture detection.
    International Congress Series 01/2006; 1288:501-503.
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    ABSTRACT: The aim of this work is to provide objective data that may serve to aid the drawing up of future database regulations according to the true situation of the forensic sciences in Spain.
    International Congress Series 01/2006; 1288:737-740.
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    ABSTRACT: Along history, Andalusia (South of the Iberian Peninsula) has been a territory occupied by many civilizations coming from Europe and North Africa. Here, we aim to identify its mitochondrial composition by analyzing the two hypervariable regions (HVS-I and HVS-II) and selected coding region SNPs of the mitochondrial DNA (mtDNA). A total of 419 individuals from 28 villages (belonging to different provinces and with more than 200 years of history) have been sampled. This sampling has been designed in order to uniformly cover the geographic area of South Iberia. Historical record indicates that these villages have experienced little recent migration. Preliminary results revealed that 94% of the haplotypes belong to typical European haplogroups, 2.1% are sub-Saharan lineages and only 1.6% North African. AMOVA analysis indicates that the main percent (97.6%) of the variability in these populations is found between individuals, 2.2% between villages of the same province and 0.25% between provinces. In addition, haplotype diversity is high (0.99) in Andalusia in comparison with other Iberian and European populations. The results point to a lack of significant demographic impact (at least in the maternal mtDNA side) of North Africa despite the close geographic proximity and eight centuries or Arabian colonization.
    International Congress Series 01/2006; 1288:106-108.
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    ABSTRACT: The 13 STRs included in CODIS are of extensive use in kinship analysis and forensic DNA testing. Investigation of relationships different from paternity/maternity are in increasing demand in forensic casework. In this study, we evaluate how the determination of allele sharing between two individuals can assist in the discrimination between a first-degree relationship and non-relationship. We have determined the number of shared alleles (0, 1 or 2) among a sample of 400 unrelated individuals, as well as in 205 parent–child pairs and 114 full-sibs pairs for the 13 mentioned STRs. The obtained results on probability of sharing a number of alleles given a relationship and likelihood ratios of a first-degree relationship vs. non-relationship are shown. An exponential correlation between the total number of shared alleles and full-sib index was observed.
    International Congress Series 01/2004; 1261:449-451.
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    ABSTRACT: Occasionally interpretation guidelines from validation studies are difficult to apply to real forensic casework, especially in the case of mixed samples. Exogenous contamination, an unknown number of contributors or unbalanced proportion of each one in the sample and a varied degree of degradation of the biological materials, contribute to the difficulties in the interpretation of sample profiles. In this paper we have reviewed all the mixed genetic STR profiles encountered in our laboratory over 4 years (1997-2000) and evaluated the problems in the interpretation of the results. From 1547 criminal cases with 2424 samples typed, 163 showed a mixed profile (6.7%). We have observed that occasionally, a mixture appeared in the same sample with one multiplex amplification kit (e.g. Blue) and not with another (e.g. Green). From our results, it can be suggested that technical characteristics of the different fluorochrome groups in the multiplexes override the molecular characteristics of each STR in their capacity to detect mixtures.
    Forensic Science International 08/2003; 134(2-3):180-6. · 2.31 Impact Factor
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    ABSTRACT: Here we present allele frequencies for 15 STRs determined in samples from unrelated individuals from Extremadura using the Profiler Plus™, COfiler™, SGM Plus™ and PowerPlex™ 16 multiplex systems. Detection was made by capillary electrophoresis with Applied Biosystems ABI 310 Prism. Some statistical parameters of forensic interest such as observed/expected heterozygosity, mean exclusion chance, discrimination power and minimum frequencies were determined. Pairwise comparison with an Andalusian population was performed using the Chi-square test for homogeneity.
    International Congress Series 01/2003; 1239:165-169.
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    ABSTRACT: We report an estimation of meiotic mutation rates at 6 minisatellites and 15 Short Tandem Repeats (STRs) deduced from the results obtained in the course of the filiation analyses carried out in our institute. At the six minisatellites, we observed 13 mutational events out of 2473 meioses, leading to a calculated overall mutation rate of 5.3×10−3. Only 3 paternal mutations out of 3283 meioses were found at the 15 STRs under study, leading to an overall mutation rate of 0.9×10−3. According to the stepwise mutation model, in these three cases the mutations could be due to the gain or loss of one repeat.
    International Congress Series 01/2003; 1239:649-652.
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    ABSTRACT: We present a study of 109 unrelated males from an Andalusian population (southern Spain) for minimal haplotype using in parallel the Y-Plex™ 6 STR kit (Reliagene Technologies) and amplification and typing protocols according to Elmoznino and Prinz (http://ystr.charite.de). Different parameters of forensic interest have been calculated.
    International Congress Series 01/2003; 1239:403-408.
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    ABSTRACT: Allele frequencies for 13 STRs (D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, THO1, TPOX, CSF1PO and D16S539) included in the AmpFlSTR Profiler Plus and COfiler kits were determined for a population sample from the Maghreb (Northern Africa).
    Forensic Science International 11/2001; 121(3):199-200. · 2.31 Impact Factor
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    ABSTRACT: Allele frequencies for seven polymerase chain reaction (PCR)-based DNA genetic markers in two Spanish populations (Southern Spain and Canary Islands), were determined and compared. The loci analysed were HLADQA1, LDLR, GYPA, HBGG, D7S8,Gc, and D1S80.
    Forensic Science International 07/2001; 119(1):116-8. · 2.31 Impact Factor
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    ABSTRACT: Allele frequencies for the 13 STRs included in the AmpFl/STR Profiler Plus and Cofiler kits were determined for an Andalusian population (southern Spain).
    Forensic Science International 07/2001; 119(1):113-5. · 2.31 Impact Factor
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    ABSTRACT: Lithium and nickel present low toxicity, but are able to cause alterations in different tissues. The toxic effects of lithium and nickel at different cellular levels were assessed using two inorganic chemical species: lithium chloride and nickel(II) chloride. Mouse neuroblastoma cell cultures (Neuro-2a) were exposed to both compounds for 24 h. The cytotoxic effects evaluated were cell proliferation by quantification of total protein content, cytoplasmic membrane integrity to cytosolic lactate dehydrogenase leakage, and lysosomal hexosaminidase release. Metabolic markers were lactate dehydrogenase activity and mitochondrial succinate dehydrogenase activity. Lysosomal markers were relative neutral red uptake by lysosomes, and lysosomal hexosaminidase sphingolipid degradation activity. Acetylcholinesterase activity on intact cells was also quantified. Nickel was found to be 36 times more toxic than lithium to neuroblastoma cell proliferation (EC(50)= 0.29 and 10.5 mM, respectively), but the relative extent of other alterations differed. Lithium stimulated nearly all the indicators studied, particularly lactate dehydrogenase, mitochondrial succinate dehydrogenase and acetylcholinesterase activities, as well as hexosaminidase release. In contrast, nickel mainly stimulated hexosaminidase release and inhibited lactate dehydrogenase activity. The stabilization of the cytoplasmic membrane to lactate dehydrogenase leakage simultaneously with the secretion of lysosomal hexosaminidase for both compounds also shows that functional metabolic alterations produced by lithium and nickel are more important than cytoplasmic damage.
    Toxicology in Vitro 01/2001; 15(4-5):363-8. · 2.65 Impact Factor
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    ABSTRACT: Chlorpromazine and other phenothiazine derivatives are neuroleptic drugs of widespread use for clinical situations beyond the realm of psychiatry, such as to control nausea, vomiting and intractable hiccups. The present study investigated in vitro different cytotoxic effects of chlorpromazine in cultures of mouse neuroblastoma cell line Neuro-2a exposed to different concentrations of this compound. Indicators assessed were cell proliferation by quantification of total protein content of the cell culture, lysosomal function evaluated by the relative uptake of neutral red cytosolic phosphofructokinase (PFK) and enolase (ENL) activities in glycolysis, mitochondrial succinate dehydrogenase (SDH) activity in the citric acid cycle, lysosomal beta-galactosidase (GAL) activity, and neuronal acetylcholinesterase activity. Marked inhibitory effects were found for cell proliferation and relative neutral red uptake; PFK, ENL and GAL activities had no significant differences from control. Stimulation was specifically detected on SDH and the Krebs cycle at concentrations up to 30 microM. Chlorpromazine did not have high toxicity for cytotoxic effects on lysosomes.
    Veterinary and human toxicology 11/1999; 41(5):273-8.
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    ABSTRACT: Allele and genotype frequencies for two tetrameric short tandem repeat (STR) loci were determined in two population samples, from Andalusia (S Spain; n = 127) and the Maghreb (N Africa; n = 40). After denaturing polyacrylamide gel electrophoresis, 14 alleles were identified for D12S391 and 13 alleles for D1S1656. No deviations from the Hardy-Weinberg equilibrium were detected. Some statistical parameters of forensic interest (H, PD, EC) were also calculated, and the data obtained for both populations were compared. Sequencing data of several intermediate D12S391 alleles designated 17.3, 18.3, and 19.3 are also presented.
    Forensic Science International 10/1999; 104(1):33-6. · 2.31 Impact Factor
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    ABSTRACT: The enzymes glutathione S,-transferase (GST) and glucose-6-phosphate dehydro-genase (G-6PDH) are implicated in the defence against oxidative stress. GST is mainly involved in the conjugation of electrophilic compounds with glutathione (GSH), although some of its isoenzymes display peroxidase activity. G-6PDH and glutathione reductase regenerate NADPH and GSH, respectively, to restore the reduced intracellular redox .status following oxidative stress. Enzymatic assays for GST and G-6PDH were adapted and optimised to permit the direct in vitro determination of the effects of toxicants which induce oxidative stress in cells on microtitre plates, thereby avoiding the need to prepare cell-free extracts. To optimise the con-ditions of the enzymatic assays, GST activity was measured a t substrate concentrations of 1-3mM GSH and 1-3mM 1-chloro-2,4-dinitrobenzene, while G-6PDH activity was measured at 7.5-37.5mM glucose-6-phosphate and 55-275mM NADP. Both enzymatic activities were directly proportional to cell number up to a density of 1 x 105 cellsiwell. The effects on GST and G-6PDH activities of three toxicants which induce oxidative stress -paraquat, iron (11) chlo-ride and iron (111) chloride -were compared in cultured Vero cells to validate the new assays. Specific GST activity increased to 145% and 171% compared to the controls in cells treated with 5mM paraquat and 5mM iron (11) chloride, respectively, but was inhibited after exposure to 25mM iron (111) chloride. Specific G-6PDH activity increased to 136% compared to the control after exposure to 5mM paraquat, but was inhibited in cells exposed to 5mM iron (11) chloride and 25mM iron (111) chloride.
    Alternatives to laboratory animals: ATLA 01/1998; 26:321-330. · 1.37 Impact Factor
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    ABSTRACT: In order to compare the effects of cocaine at morphological, basal cytotoxicity, biochemical and molecular levels, cultured mouse neuroblastoma cells (Neuro-2a) were exposed to a range of concentrations of cocaine hydrochloride. Neuroblastoma cell proliferation, evaluated by quantification of total protein content, was very sensitive to cocaine, being increasingly inhibited from 12 to 72 hr of exposure (EC(50) = 3.1 mm at 24 hr). Cytoplasmic membrane permeability to lactate dehydrogenase was not particularly increased and lysosomal function was stimulated from 0.05 to 1.5 mm, and inhibited from 2.5 mm. A shift to anaerobiosis was detected as intracellular lactate dehydrogenase (LDH) activity was increased and mitochondrial succinate dehydrogenase (SDH) activity decreased. Hexosaminidase (HEX), a lysosomal enzyme involved in sphingolipid degradation, was stimulated only at 1 mm and neural acetylcholinesterase (AChE) activity was stimulated from 2.5 mm. Morphological examination of exposed cultures revealed that most cells became bipolar and multipolar neurons by extension of neurites, but also suffered cytoplasmic vacuolization, hydropic degeneration and nuclear pyknosis. Although cells developing apoptosis were observed, no DNA oligonucleosomal fragmentation was detected by agarose gel electrophoresis of DNA from cells exposed to cocaine. In conclusion, in addition to predominance of anaerobiosis, little disruption of membranes and severe morphologic injury, biochemical and morphological differentiation-like effects were the most prominent alterations produced by cocaine on mouse neuroblastoma cells.
    Toxicology in Vitro 10/1997; 11(5):519-25. · 2.65 Impact Factor
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    ABSTRACT: Since 1992 the Spanish and Portuguese Working Group (GEP) of the International Society for Forensic Haemogenetics (ISFH) has been organizing collaborative exercises on DNA profiling with the aim of making progress on standardization and discussing technical and statistical problems in DNA analysis. A total of four exercises (GEP-92 to GEP-95) have been carried out until now. A consequence of these exercises was the creation of a quality control programme in Spain and Portugal in 1995 which was carried out simultaneously with the GEP-95 exercise. The number of participating laboratories increased from 10 in the first exercise (GEP-92) to 19 in the last exercise (GEP-95). Despite this increasing number of participating laboratories, results remained satisfactory. In the last exercises, all the laboratories used PCR-based DNA polymorphisms with an increasing number of markers obtaining good results. SLPs were used by only 30% of laboratories in the last two exercises but the results indicated a good level of expertise in most of these laboratories. The reasons for these successful results are the common use of the EDNAP protocol for SLP analysis and commercially available kits or common sequenced allelic ladders for PCR-based DNA polymorphisms.
    Deutsche Zeitschrift für die Gesamte Gerichtliche Medizin 02/1997; 110(5):273-7. · 2.69 Impact Factor
  • European Journal of Pharmaceutics and Biopharmaceutics 01/1997; 44(2). · 3.83 Impact Factor
  • Toxicology Letters 09/1996; 88:41-42. · 3.15 Impact Factor