Sandra Assis

Exploring the Relationship Between Entheseal Changes and Physical Activity: A Multivariate Study

Analyses of entheseal changes (EC) in identified skeletal samples employ a common research strategy based on the comparison between occupations grouped on the basis of shared biomechanical and/or social characteristics. Results from this approach are often ambiguous, with some studies that point to differences in EC between occupational samples and others failing to provide evidence of behavioral effects on EC. Here we investigate patterns of EC among documented occupations by means of a multivariate analysis of robusticity scores in nine postcranial entheses from a large (N = 372) contemporary skeletal sample including specimens from one Italian and two Portuguese identified collections. Data on entheseal robusticity, analyzed by pooled sides as well by separated sides and levels of asymmetry, are converted in binary scores and then analyzed through nonlinear principal component analysis and hierarchical cluster analysis. Results of these analyses are then used for the classification of occupations. Differences between occupational classes are tested by MANOVA and pairwise Hotellings test. Results evidence three classes which separate occupations related to farming, physically demanding but generalized occupation, and physically undemanding occupations, with the more consistent differences between the first and the last classes. Our results are consistent with differences in biomechanical behavior between the occupations included in each class, and point to the physical and social specificity of farming activities. On the other hand, our study exemplifies the usefulness of alternative analytical protocols for the investigation of EC, and the value of research designs devoid of a priori assumptions for the test of biocultural hypotheses.

Evidence of hypertrophic osteoarthropathy in individuals from the Coimbra Skeletal Identified Collection (Portugal)

Hypertrophic osteoarthropathy (HOA) is characterized by symmetrical periosteal new bone deposition on the long and short tubular bones. Besides its unknown etiology, it has been associated with pulmonary, cardiovascular and gastrointestinal disorders. The aims of this research were to assess the presence of HOA and to analyze its distribution by sex, age at death, bones affected, type of new bone formed, and cause of death. A sample of 329 individuals (non-adults and adults, of both sexes) was selected from the Coimbra Skeletal Identified Collection. The sample comprised 125 individuals diagnosed with tuberculosis, 64 with pulmonary non-tuberculosis, and 140 with an extrapulmonary and non-tuberculous cause of death. Lesions compatible with HOA were found in all three groups, being statistically significantly in the individuals who died from pulmonary diseases (χ2=5.29, df=1, p=0.02). The risk of developing HOA was 3.41 (χ2=7.77, df=1, p=0.005) higher in the individuals with tuberculosis when compared with the other groups. This work, based on individuals who died before the introduction of antibiotics for treatment, agrees with clinical studies that have established a possible correlation between pulmonary conditions and HOA. These data may help in differentially diagnosing the many instances of periosteal new bone formation found in archaeologically derived skeletal samples.

In search of consensus: Terminology for entheseal changes (EC)

This article presents a consensus terminology for entheseal changes that was developed in English by an international team of scholars and then translated into French, Italian, Portuguese, Spanish and German. Use of a standard, neutral terminology to describe entheseal morphology will reduce misunderstandings between researchers, improve the reliability of comparisons between studies, and eliminate unwarranted etiological assumptions inherent in some of the descriptive terms presently used in the literature.

Exploring poverty: skeletal biology and documentary evidence in 19th–20th century Portugal

Abstract Background: The inference of the state of wealth or poverty from human skeletal remains is a difficult task, as the limited number of skeletal changes are mediated by numerous other physiological, biomechanical and pathological events. In recent years, identified skeletal collections have become valuable resources in enabling aetiologies of these changes to be understood while controlling for some known causative factors, e.g. age, sex and occupation. This has favoured more rigorous data analysis and interpretation. Aim: This study compares the presence of osteological makers of occupation – specifically degenerative joint changes (DJC) – between socio-economically framed occupational groups whilst controlling for age-at-death. Materials and methods: A total of 603 individuals were distributed into seven occupational groups used as a proxy for their socio-economic status. Results: The results demonstrated that age was a contributing factor for DJC. Differences between occupational groups were only found for the hips, right shoulder and ankle. Conclusions: Differences found were not necessarily representative of low vs high socio-economic status. Furthermore, there are limitations associated with the use of occupation-at-death, based on documentary evidence, which does not necessarily reflect wealth-status.

Below the Callus Surface: Applying Paleohistological Techniques to Understand the Biology of Bone Healing in Skeletonized Human Remains

Objectives: Bone trauma is a common occurrence in human skeletal remains. Macroscopic and imaging scrutiny is the approach most currently used to analyze and describe trauma. Nevertheless, this line of inquiry may not be sufficient to accurately identify the type of traumatic lesion and the associated degree of bone healing. To test the usefulness of histology in the examination of bone healing biology, we used an integrative approach that combines gross inspection and microscopy. Materials and Methods: Six bone samples belonging to 5 adult individuals with signs of bone trauma were collected from the Human Identified Skeletal Collection from the Museu Bocage (Lisbon, Portugal). Previous to sampling, the lesions were described according to their location, morphology, and healing status. After sampling, the bone specimens were prepared for plane light and polarized light analysis. Results: The histological analysis was pivotal: (1) to differentiate between types of traumatic lesions; (2) to ascertain the posttraumatic interval, and (3) to diagnose other associated pathological conditions. Conclusion: The outer surface of a bone lesion may not give a complete picture of the biology of the tissues response. Accordingly, microscopic analysis is essential to differentiate, characterize, and classify trauma signs.

Bone Diagenesis and its Implication for Disease Diagnosis: The Relevance of Bone Microstructure Analysis for the Study of Past Human Remains.

When bone is exposed to the burial environment it may experience structural changes induced by multiple agents. The study of postmortem alterations is important to differentiate decomposition phenomena from normal physiological processes or pathological lesions, as well as to assess bone tissue quality. Microscopy is of great utility to evaluate the integrity of bone microstructure and it provides significant data on long-term bone decomposition. A total of 18 human bone sections (eight archeological and ten retrieved from an identified skeletal collection) were selected for analysis under plane light and polarized light. The aim of this exploratory study was to analyze the impact of diagenesis and taphonomy on the bone microstructure, as well as on the differential diagnosis of pathological conditions. The results showed that the microscopy approach to bone tissues contributed materially as an aid in the detailed description of the main diagenetic changes observed. It showed that gross inspection does not provide a realistic assessment of bone tissue preservation, which can impact in the characterization of lesions present and subsequent disease diagnosis. Therefore, researchers should continue to consider the application of histological techniques if the aim is to comprehend tissue integrity and its association with decomposition or disease.

Evolutionism and the Teaching of Science: How Portugal Has Been “Playing with the Big Tree of Evolution”

The concept of evolution is fundamental to the teaching of biological sciences. Nevertheless, it seems frequently neglected and/or forgotten in our classrooms and absent from the school syllabus. These difficulties are present today in the Portuguese educational system, especially concerning the issue of human evolution. To overcome this difficulty, a multidisciplinary pilot project entitled Playing with the Big Tree of Evolution was developed by a nonprofit association called Group of Studies in Human Evolution in Portuguese schools and in other public and private organizations. Combining non-formal and informal apprenticeship, the project is composed of a set of pedagogical and experimental activities that aim to promote the broad concept of human evolution as well as to demystify the anthropocentric perspective that places humans at the top of the chain of life.

Is it a cystic or a cyst-like condition? Discussing the etiology of an unusual large mandibular lesion in a Roman skeleton from Quinta da Torrinha/Quinta de Santo António (Almada, Portugal)

Cystic and cyst-like lesions of the jaw are a recurrent finding in routine dental radiography but not in paleopathology. This paper describes a large oval osteolytic cavity (23 × 14 mm) observed in the mandible of a middle-aged female unearthed from the Roman necropolis of Quinta da Torrinha/Quinta de Santo António (Almada, Portugal, 3rd-5th centuries AD). The lesion was located in the body of the mandible, inferior to the alveolus of the first left molar. The associated tooth exhibited a carious lesion that destroyed the tooth crown and exposed the pulp cavity. The osteolytic lesion presented inner smooth walls and sharped regular contours, surrounded by slight microporosity. Radiography revealed an unilocular lesion with well-defined contours and a thin opaque rim. The differential diagnosis considered several odontogenic and non-odontogenic conditions of the jaw. The size and shape of the cavity, the nature of its walls and contours, and the presence of a source of infection in the pulp is consistent with an odontogenic condition of inflammatory origin, probably a radicular cyst.

Exploring the relationship between entheseal changes and physical activity

Analyses of entheseal changes (EC) in identified skeletal samples employ a common research strategy based on the comparison between occupations grouped on the basis of shared biomechanical and/or social characteristics. Results from this approach are often ambiguous, with some studies that point to differences in EC between occupational samples and others failing to provide evidence of behavioral effects on EC. Here we investigate patterns of EC among documented occupations by means of a multivariate analysis of robusticity scores in nine postcranial entheses from a large (N = 372) contemporary skeletal sample including specimens from one Italian and two Portuguese identified collections. Data on entheseal robusticity, analyzed by pooled sides as well by separated sides and levels of asymmetry, are converted in binary scores and then analyzed through nonlinear principal component analysis and hierarchical cluster analysis. Results of these analyses are then used for the classification of occupations. Differences between occupational classes are tested by MANOVA and pairwise Hotellings test. Results evidence three classes which separate occupations related to farming, physically demanding but generalized occupation, and physically undemanding occupations, with the more consistent differences between the first and the last classes. Our results are consistent with differences in biomechanical behavior between the occupations included in each class, and point to the physical and social specificity of farming activities. On the other hand, our study exemplifies the usefulness of alternative analytical protocols for the investigation of EC, and the value of research designs devoid of a priori assumptions for the test of biocultural hypotheses.

Exploring the relationship between entheseal changes and physical activity: A multivariate study: A Multivariate Study of Entheseal Robusticity

Analyses of entheseal changes (EC) in identified skeletal samples employ a common research strategy based on the comparison between occupations grouped on the basis of shared biomechanical and/or social characteristics. Results from this approach are often ambiguous, with some studies that point to differences in EC between occupational samples and others failing to provide evidence of behavioral effects on EC. Here we investigate patterns of EC among documented occupations by means of a multivariate analysis of robusticity scores in nine postcranial entheses from a large (N = 372) contemporary skeletal sample including specimens from one Italian and two Portuguese identified collections. Data on entheseal robusticity, analyzed by pooled sides as well by separated sides and levels of asymmetry, are converted in binary scores and then analyzed through nonlinear principal component analysis and hierarchical cluster analysis. Results of these analyses are then used for the classification of occupations. Differences between occupational classes are tested by MANOVA and pairwise Hotellings test. Results evidence three classes which separate occupations related to farming, physically demanding but generalized occupation, and physically undemanding occupations, with the more consistent differences between the first and the last classes. Our results are consistent with differences in biomechanical behavior between the occupations included in each class, and point to the physical and social specificity of farming activities. On the other hand, our study exemplifies the usefulness of alternative analytical protocols for the investigation of EC, and the value of research designs devoid of a priori assumptions for the test of biocultural hypotheses.