José Antonio Sánchez

Sexual Determination of the Femur Using Discriminant Functions. Analysis of a Spanish Population of Known Sex and Age

Until present, functions for sexual discrimination of a Spanish population from series of known sex and age were not available. In this work, we present a sample of 132 femora (72 females and 60 males) belonging to a Spanish population of adult individuals of known filiation deposited in the Complutense University of Madrid. The ten mathematical functions which yield a higher sexual discrimination in each part of the femur, were selected. The resulting percentages of correspondence varied between 84 and 97% when each variable was considered independently, and a 99% is obtained with two variables of the epiphyses combined.

Metacarpal Sexual Determination in a Spanish Population

ABSTRACT: Anthropologists and forensic pathologist determine the sex of skeletons by analyzing quantitative and qualitative characters in the bone remains. Generally, the skull and os coxae are the elements most used, but they are not always preserved. In such cases, the investigator needs to have available other techniques based on different remains. The aim of the present work is to develop and describe discriminating functions for sex determination in a recent Spanish population using metacarpal morphology. A sample of bones corresponding to a contemporary Spanish population deposited at the Complutense University of Madrid (UCM) was analyzed. This sample comprised 697 metacarpals, corresponding to 79 adult individuals (37 men and 42 women). These allowed us to obtain 120 unifactorial discriminant functions. We selected the 10 equations, one for each metacarpal from both hands, that provided the best sexual discrimination. The correct sex classification rank progressed from 81%, for right (R) metacarpals IV and V, to 91%, for left (L) metacarpal II. The results suggest that metacarpals are structures that can be used for sex determination in paleoanthropological and forensic identifications.

Collagen α1(I) Gene Contains an Element Responsive to Tumor Necrosis Factor-α Located in the 5' Untranslated Region of Its First Exon

The aims of the present study were to identify the cis-acting element through which tumor necrosis factor-α (TNFα) inhibits collagen alpha 1(I) gene transcription and the trans-acting factors invol...

Determining sex by bone volume from 3D images: discriminating analysis of the tali and radii in a contemporary Spanish reference collection

The discriminant power of bone volume for determining sex has not been possible to determine due to the difficulty in its calculation. At present, new advancements based on 3D technology make it possible to reproduce the bone digitally and calculate its volume using computerized tools, which opens up a new window to ascertaining the discriminant power of this variable. With this objective in mind, the tali and radii of 101 individuals (48 males and 53 females) of a contemporary Spanish reference collection (twentieth century) (EML 1) were scanned using the Picza 3D Laser Scanner. Calculated for the tali were total volume, the volume of the posterior region, which includes the posterior calcaneal facet and other three volumes of the anterior region. Calculated for the radius were total volume, volume of the radius head, volume of the diaphysis, and volume of the distal end. The data are presented for all of the variables, distinguishing between the right and left side. The data were processed using the statistical program PASW Statistics 18, thereby obtaining classification functions for sex which accurately classify 90.9xa0% of tali and 93.9xa0% of radii on the basis of their total left and right volume, respectively. Studying the volume in different regions of the bone shows that the diaphysis of the right radius possesses a high level of discriminant power, offering classification functions which accurately classify 96.9xa0% of the sample. The validation test performed on a sample of 20 individuals from another contemporary Spanish reference collection (EML 2) confirms the high discriminant power of the volume obtaining an accurate classification rate of 80–95xa0% depending on the variable studied.The discriminant power of bone volume for determining sex has not been possible to determine due to the difficulty in its calculation. At present, new advancements based on 3D technology make it possible to reproduce the bone digitally and calculate its volume using computerized tools, which opens up a new window to ascertaining the discriminant power of this variable. With this objective in mind, the tali and radii of 101 individuals (48 males and 53 females) of a contemporary Spanish reference collection (twentieth century) (EML 1) were scanned using the Picza 3D Laser Scanner. Calculated for the tali were total volume, the volume of the posterior region, which includes the posterior calcaneal facet and other three volumes of the anterior region. Calculated for the radius were total volume, volume of the radius head, volume of the diaphysis, and volume of the distal end. The data are presented for all of the variables, distinguishing between the right and left side. The data were processed using the statistical program PASW Statistics 18, thereby obtaining classification functions for sex which accurately classify 90.9xa0% of tali and 93.9xa0% of radii on the basis of their total left and right volume, respectively. Studying the volume in different regions of the bone shows that the diaphysis of the right radius possesses a high level of discriminant power, offering classification functions which accurately classify 96.9xa0% of the sample. The validation test performed on a sample of 20 individuals from another contemporary Spanish reference collection (EML 2) confirms the high discriminant power of the volume obtaining an accurate classification rate of 80–95xa0% depending on the variable studied.

G Proteins Are Involved in the Suppression of Collagen α1(I) Gene Expression in Cultured Rat Hepatic Stellate Cells

We analyse the role of the G proteins in regulating collagen gene expression by measuring collagen alpha 1(I) mRNA levels in cultured hepatic stellate cells in basal conditions and after stimulating or inhibiting the major intracellular signalling pathways. Stimulation of Gs protein and adenylyl cyclase or the addition of 8Br-cAMP to the cells led to a decrease in collagen alpha 1(I) mRNA levels, while blocking protein kinase A abolished this effect. Blocking Gi protein, phospholipase A2 and C, calcium channels and calmodulin resulted in a significant increase in collagen mRNA levels. PKC stimulation led to a marked decrease in these levels. These results suggest that collagen gene expression is inhibited by a number of intracellular pathways. A Gs and a pertussis toxin-sensitive G protein seem to initiate cellular response. Transcription factors, acting in these pathways, must be identified. However, it seems that they do not need to be synthesised.

Estimating legal age based on fusion of The proximal humeral epiphysis

The increasing demand which requires ascertaining the legal age of undocumented individuals who reach the various countries of the European Community means that new lines of research must be developed which help respond to questions posed by the Justice Administration. For this reason, this study has been designed on the basis of fusion times of the proximal humeral epiphysis. Moreover, the ultrasound scan has been used as the diagnostic method. It is a non-invasive technique, unlike the radiograph, which is used under current standards for the forensic diagnosis of age. Used as a study sample were the ultrasound images of the proximal humeral epiphysis among 221 individuals belonging to the Spanish population, of both genders, of ages ranging from 5 to 30xa0years. All of the images were classified into 6 stages of fusion based on the morphology of each. The results display differences among the six age groups proposed for each of the stages of fusion and are of great interest from the perspective of enforcing the Spanish Criminal Law Act on Minors, because Stage 4 would mean that the person being studied is under the age of 16xa0years in the case of males and 15xa0years in the case of females. These results, coupled with the use of ultrasound as a non-invasive diagnostic technique, make this study a very useful method when the use of radiographs is not possible.

Determining sex with the clavicle in a contemporary Spanish reference collection: A study on 3D images

Sexual dimorphism of the clavicle based on metric studies has been determined among different populations from different eras. Due to the need to know about sexual dimorphism in the Spanish population in order to apply the results to the field of Forensic Anthropology, a study has been carried out on a sample in the contemporary Spanish population, made up of the right and left clavicles of 50 males and 50 females. A metric, volumetric and curvature study was performed. To do so, 3D scanning was completed on the entire sample using the Picza 3D Laser Scanner, and the study was performed using reproductions. There were taken 6 metric measurements and 4 volumetric measurements using the Geomagic software, and for the study of curves, an index was calculated which related the direct length of the clavicle and its length as cast onto a surface. The data are presented for all of the variables, distinguishing between the right and left side, and there were processed using the statistical program PASW Statistics 18. The results show that the classification functions which best categorize the sample with an unique variable are volumetric, which classify the sample correctly in 94% of cases based on diaphysis volume, followed by total volume, which provides an accurate classification in 92% of all cases. The sagittal diameter at midshaft provides an accurate classification in 90% of cases and the maximum length in 88% of cases. The curvature index shows that there are no statistically significant differences by side and the only curvature index that shows significant differences by sex is the total anterior curve of the left clavicle being the males curve more pronounced. The validation study performed on a sample of 20 individuals confirms the high discriminatory power of the volume obtaining an accurate classification rate of 85-100% depending on the variable studied.

Age-at-death estimation based on radiological and image analysis methods in clavicle in a current Spanish population

Age-at-death estimation in adult individuals is one of the most challenging issues in forensic anthropology, namely, due to the large age intervals provided by the current methods, which demand the development of more reliable investigations. The clavicle has been studied as an age-at-death indicator in many researches for its accessibility, low biomechanical implication in locomotion and accuracy to predict age at death when other age indicators are not available. The present study was developed on a sample of 332 clavicles from adult individuals of known sex and age from the current Spanish population. They were x-rayed and digitalized, in a standardized way, using a Sedecal X-ray generator, model SHF 415. Three indices were calculated at the mid-diaphysis point (anterior index, posterior index, and total index) which relate the cortical thickness and the total clavicle thickness to age at death. The average grey level was also calculated in a 0.5-cm2 area of the sternal and acromial ends (sternal grey average, acromial grey average), using Image J software. The data were subjected to a statistical analysis, using SPSS, version 15.0. The results show that average grey level has a weaker correlation with age than the variables which are based on the cortical thickness. On the other hand, the regression equations, which were calculated combining all the variables, provided smaller age-at-death intervals, demonstrating the usefulness of this method for adult age-at-death estimation in forensic anthropology.

Sex and age at death estimation from the sternal end of the fourth rib. Does Íşcan’s method really work?

The fourth rib has been used commonly in order to estimate age at death and even sex in skeletal remains but many often, Iscans estimates do not adjust to the real age of the individual. Population specific references for sex and age-at-death estimation from the sternal end of the fourth rib are presented for a contemporary Mexican sample. A total of 504 ribs with known sex and age from a morgue sample were studied (444 males, 60 females, 17 to 92u202fyears old). The height and breadth of the sternal end of the rib were sexually dimorphic (pu202f=u202f.000), and allowed a correct sex assignment in 73.3% to 84% of the cases from univariate and multivariate discriminant functions. With regard to age-at-death estimation, the morphological changes summarized by the phases of the sternal end of the fourth rib are correlated with known age in this sample (Spearmans Rho, pu202f=u202f.000). However, the original age intervals tend to underestimate age at death and inaccuracy increases with phase scored in males. Descriptive statistics for rib phase are provided for males and females, and new age-at-death estimates based on transition analysis and Bayesian statistics are provided for the male sample. The test of universally applied methods and the development of population specific references is an important task for forensic anthropology around the world.

Contribution of dental tissues to sex determination in modern human populations

OBJECTIVESnAccurate sex estimation is an essential step for the reconstruction of the biological profile of human remains. Earlier studies have shown that elements of the human permanent dentition are sexually dimorphic. The aims of this study are to determine the degree of sexual dimorphism in the dental tissue volumes and surface areas of mandibular canines and to explore its potential for reliable sex determination.nnnMETHODnThe teeth included in this study (nu2009=u200969) were selected from anthropological collections from Spain, South Africa and Sudan. In all cases, the sex of the individuals was known. The teeth were scanned and three-dimensional (3D) measurements (volumes and surfaces areas) were obtained. Finally, a dsicriminant function analysis was applied.nnnRESULTSnOur results showed that sexual dimorphism in canine size is due to males having greater amounts of dentine, whereas enamel volume does not contribute significantly to overall tooth size dimorphism. Classification accuracy of the multivariable equations tested on slightly worn teeth ranged from 78 to 90.2% for the crossvalidation, and from 71.43 to 84.62% for the hold-out sample validation. When all functions were applied together, the sex was correctly assigned 92.30% of the time.nnnCONCLUSIONSnOur results suggest that the 3D variables from mandibular canine dental tissues are useful for sex determination as they present a high degree of dimorphism. The results obtained show the importance of 3D dental tissue measurements as a methodology in sex determination, which application should be considered as a supplemental method to others.