Morphometric profile of tendocalcaneus of South Africans of European ancestry using a cadaveric approach

Background: Tendocalcaneus is a strong tendon that is vital for bipedalism in humans. Despite its tremendous strength, the tendocalcaneus is prone to damage and degeneration causing mobility problems and pain. Morphometric dimension of the tendocalcaneus is of benefit to the surgical repair and reconstruction of the damaged tendon. Cadaveric approach provides a realistic method for determining tendocalcaneus morphometry and as at present only two cadaveric studies on Indian population is available. Thus this study presents data on tendocalcaneus morphometry in South Africans of European ancestry using a cadaveric approach. Materials and methods: A total of 66 lower limbs (32 left and 34 right legs) sourced from 49 male and female cadavers were used. After careful dissection of the posterior aspect of leg, the medial and lateral length, distal width, distal circumference and proximal width of the tendocalcaneus were measured. Results: The data showed a high degree of reproducibility indicating that the measurements obtained using cadaveric approach were precise and accurate. There was no difference in measurements between the sides. Measurements in the males were generally higher than in the females. Strong associations were observed between the paired measurements of the medial and lateral tendon length and between the distal width and distal circumference. Conclusions: The data obtained will be useful in predicting tendocalcaneus size during the surgical reconstruction of the tendocalcaneus

Estimation of sex from metatarsals using discriminant function and logistic regression analyses

© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. South Africa has one of the highest crime rates in the world and the discovery of dismembered bodies for human identification process poses a greater challenge. The South African Africans (also known as South African blacks) population group is often the victims of crimes as they are the largest group. While measurements of several bones of the human skeleton have been used for sex estimation, the potential of metatarsals have not been explored in this population group. Metatarsal bones are usually well-preserved since they are recovered in shoes protected from scavengers and they are able to withstand environmental degradation and taphonomy. This study investigated the potential of measurements of metatarsals in sex estimate amongst South African Africans using logistic and discriminant function analysis. Six measurements of metatarsals from 100 individuals of known sex and population affinity from the Raymond Dart Collection of Human skeletons were analysed. Various combinations of measurements of metatarsal bones yielded suitably high average accuracies (79% to 84%) for sex estimation and are comparable to functions derived from other skeletal elements of South African Africans. Metatarsals of South African Africans are therefore useful as alternatives to highly sexual dimorphic bones in the forensic estimation of sex

Morphometric profile of tendocalcaneus of South Africans of European ancestry using a cadaveric approach.

Tendocalcaneus is a strong tendon that is vital for bipedalism in humans. Despite its tremendous strength, the tendocalcaneus is prone to damage and degeneration causing mobility problems and pain. Morphometric dimension of the tendocalcaneus is of benefit to the surgical repair and reconstruction of the damaged tendon. Cadaveric approach provides a realistic method for determining tendocalcaneus morphometry and as at present only two cadaveric studies on Indian population is available. Thus this study presents data on tendocalcaneus morphometry in South Africans of European ancestry using a cadaveric approach. A total of 66 lower limbs (32 left and 34 right legs) sourced from 49 male and female cadavers were used. After careful dissection of the posterior aspect of leg, the medial and lateral length, distal width, distal circumference and proximal width of the tendocalcaneus were measured. The data showed a high degree of reproducibility indicating that the measurements obtained using cadaveric approach were precise and accurate. There was no difference in measurements between the sides. Measurements in the males were generally higher than in the females. Strong associations were observed between the paired measurements of the medial and lateral tendon length and between the distal width and distal circumference. The data obtained will be useful in predicting tendocalcaneus size during the surgical reconstruction of the tendocalcaneus

Estimation of stature from the foot and its segments in a sub-adult female population of North India

<p>Abstract</p> <p>Background</p> <p>Establishing personal identity is one of the main concerns in forensic investigations. Estimation of stature forms a basic domain of the investigation process in unknown and co-mingled human remains in forensic anthropology case work. The objective of the present study was to set up standards for estimation of stature from the foot and its segments in a sub-adult female population.</p> <p>Methods</p> <p>The sample for the study constituted 149 young females from the Northern part of India. The participants were aged between 13 and 18 years. Besides stature, seven anthropometric measurements that included length of the foot from each toe (T1, T2, T3, T4, and T5 respectively), foot breadth at ball (BBAL) and foot breadth at heel (BHEL) were measured on both feet in each participant using standard methods and techniques.</p> <p>Results</p> <p>The results indicated that statistically significant differences (p < 0.05) between left and right feet occur in both the foot breadth measurements (BBAL and BHEL). Foot length measurements (T1 to T5 lengths) did not show any statistically significant bilateral asymmetry. The correlation between stature and all the foot measurements was found to be positive and statistically significant (<it>p-value </it>< 0.001). Linear regression models and multiple regression models were derived for estimation of stature from the measurements of the foot. The present study indicates that anthropometric measurements of foot and its segments are valuable in the estimation of stature. Foot length measurements estimate stature with greater accuracy when compared to foot breadth measurements.</p> <p>Conclusions</p> <p>The present study concluded that foot measurements have a strong relationship with stature in the sub-adult female population of North India. Hence, the stature of an individual can be successfully estimated from the foot and its segments using different regression models derived in the study. The regression models derived in the study may be applied successfully for the estimation of stature in sub-adult females, whenever foot remains are brought for forensic examination. Stepwise multiple regression models tend to estimate stature more accurately than linear regression models in female sub-adults.</p

Prevalence and phase variable expression status of two autotransporters, NalP and MspA, in carriage and disease isolates of Neisseria meningitidis.

Neisseria meningitidis is a human nasopharyngeal commensal capable of causing life-threatening septicemia and meningitis. Many meningococcal surface structures, including the autotransporter proteins NalP and MspA, are subject to phase variation (PV) due to the presence of homopolymeric tracts within their coding sequences. The functions of MspA are unknown. NalP proteolytically cleaves several surface-located virulence factors including the 4CMenB antigen NhbA. Therefore, NalP is a phase-variable regulator of the meningococcal outer membrane and secretome whose expression may reduce isolate susceptibility to 4CMenB-induced immune responses. To improve our understanding of the contributions of MspA and NalP to meningococcal-host interactions, their distribution and phase-variable expression status was studied in epidemiologically relevant samples, including 127 carriage and 514 invasive isolates representative of multiple clonal complexes and serogroups. Prevalence estimates of >98% and >88% were obtained for mspA and nalP, respectively, with no significant differences in their frequencies in disease versus carriage isolates. 16% of serogroup B (MenB) invasive isolates, predominately from clonal complexes ST-269 and ST-461, lacked nalP. Deletion of nalP often resulted from recombination events between flanking repetitive elements. PolyC tract lengths ranged from 6-15 bp in nalP and 6-14 bp in mspA. In an examination of PV status, 58.8% of carriage, and 40.1% of invasive nalP-positive MenB isolates were nalP phase ON. The frequency of this phenotype was not significantly different in serogroup Y (MenY) carriage strains, but was significantly higher in invasive MenY strains (86.3%; p<0.0001). Approximately 90% of MenB carriage and invasive isolates were mspA phase ON; significantly more than MenY carriage (32.7%) or invasive (13.7%) isolates. This differential expression resulted from different mode mspA tract lengths between the serogroups. Our data indicates a differential requirement for NalP and MspA expression in MenB and MenY strains and is a step towards understanding the contributions of phase-variable loci to meningococcal biology

Influence of the combination and phase variation status of the haemoglobin receptors HmbR and HpuAB on meningococcal virulence

Neisseria meningitidis can utilize haem, haemoglobin and haemoglobin–haptoglobin complexes as sources of iron via two TonB-dependent phase variable haemoglobin receptors, HmbR and HpuAB. HmbR is over-represented in disease isolates, suggesting a link between haemoglobin acquisition and meningococcal disease. This study compared the distribution of HpuAB and phase variation (PV) status of both receptors in disease and carriage isolates. Meningococcal disease (n = 214) and carriage (n = 305) isolates representative of multiple clonal complexes (CCs) were investigated for the distribution, polyG tract lengths and ON/OFF status of both haemoglobin receptors, and for the deletion mechanism for HpuAB. Strains with both receptors or only hmbR were present at similar frequencies among meningococcal disease isolates as compared with carriage isolates. However, >90 % of isolates from the three CCs CC5, CC8 and CC11 with the highest disease to carriage ratios contained both receptors. Strains with an hpuAB-only phenotype were under-represented among disease isolates, suggesting selection against this receptor during systemic disease, possibly due to the receptor having a high level of immunogenicity or being inefficient in acquisition of iron during systemic spread. Absence of hpuAB resulted from either complete deletion or replacement by an insertion element. In an examination of PV status, one or both receptors were found in an ON state in 91 % of disease and 71 % of carriage isolates. We suggest that expression of a haemoglobin receptor, either HmbR or HpuAB, is of major importance for systemic spread of meningococci, and that the presence of both receptors contributes to virulence in some strains

Measurements of the talus in the assessment of population affinity

© 2018 Elsevier B.V. As part of their routine work, forensic anthropologists are expected to report population affinity as part of the biological profile of an individual. The skull is the most widely used bone for the estimation of population affinity but it is not always present in a forensic case. Thus, other bones that preserve well have been shown to give a good indication of either the sex or population affinity of an individual. In this study, the potential of measurements of the talus was investigated for the purpose of estimating population affinity in South Africans. Nine measurements from two hundred and twenty tali of South African Africans (SAA) and South African Whites (SAW) from the Raymond A. Dart Collection of Human Skeletons were used. Direct and step-wise discriminant function and logistic regression analyses were carried out using SPSS and SAS. Talar length was the best single variable for discriminating between these two groups for males while in females the head height was the best single predictor. Average accuracies for correct population affinity classification using logistic regression analysis were higher than those obtained from discriminant function analysis. This study was the first of its type to employ discriminant function analyses and logistic regression analyses to estimate the population affinity of an individual from the talus. Thus these equations can now be used by South African anthropologists when estimating the population affinity of dismembered or damaged or incomplete skeletal remains of SAA and SAW

Assessing the accuracy of the anatomical method for stature estimation in White South African males

The anatomical method is considered the most accurate stature estimation method, however, research has concluded that the soft-tissue correction factors associated with this method may be sex- and population-specific. Therefore, this study aimed to evaluate the applicability of these soft-tissue correction factors for the estimation of stature in White South African males. Magnetic resonance imaging scans of 30 White South African male volunteers, between 21 and 59 years of age, were used to collect skeletal measurements of bones that contribute to total skeletal height. The soft-tissue correction factors within the literature were subsequently applied to estimate the living stature of each individual. Paired t-tests were used to compare the accuracies of these estimates of living stature to the measured heights of the participants. Living stature was significantly underestimated using the soft-tissue correction factors of Fully (1956; 6.14 cm), Raxter and colleagues (2006; 4.80 cm), and Brits and colleagues (2017; 0.96 cm), and significantly overestimated by Bidmos and Manger (2012; 9.65 cm). Cloete’s (2017) equation overestimated stature by 0.65 cm, however, this was not significant. These results suggest population-specific soft-tissue correction factors associated with stature estimation and, therefore, the newly derived stature estimation equations should be used to estimate stature of White South African males.This work was supported by the National Research Foundation (NRF) – through Thuthuka grants (80655/118149)