Anatomy and Histology
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Browsing Anatomy and Histology by browse.metadata.advisor "Alblas, Amanda"
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- ItemThe correlation between cranial and post-cranial skeletal elements for resolving and reconstruction of comingled skeletal remains in victim identification(Stellenbosch : Stellenbosch University, 2019-04) Marais, Johan Christian; Alblas, Amanda; Greyling, L. M.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.ENGLISH ABSTRACT: Upon discovery of comingled disarticulated skeletons, actual matching of different skeletal elements to a particular individual can be extremely difficult. Available literature regarding the matching of skeletal elements, show few studies correlating skull measurements with post-cranial elements, with the majority of cases determining correlations with stature. The aim of this study is to assess the degree of correlation between cranial and post-cranial skeletal elements, of the three dominant South African population groups, by means of direct correlations of measurements. Skeletons of individuals (N=296) of both males (n=148) and females (n=148) of South African black (n=100), South African white (n=97) and South African coloured (n=99) population groups, were assessed in three distinct manners. Firstly, three correlation sets were recorded: 21 cephalometric elements were correlated with eight long-bone measurements, and six occipital condyle measurements with morphologically mirrored measurements on the superior articular facet of the first cervical vertebra were correlated. The last of the correlation sets consisted of the lengths and breadths of the neural foramina from foramen magnum up to C2. Secondly, Principal Component Analyses were conducted on the 21 cephalometric elements, the eight long-bones measurements, the 12 articular facet measurements, and the six neural canal measurements. Lastly, t-tests were conducted to determine if any of the measurements were sexually different. From these assessments, a connection between some of the cephalometric elements and the long bones were observed. Most notably, the novel construct known as representative facial height (NLH.MRH), which is the summation of the nasal height and the maximum ramus height of the mandible for all three population groups. The South African white males, however, showed a much weaker connection with NLH.MRH, though, the basion-bregma height correlated well with the long bones. It was determined that the length measurements outperformed the breadth measurements in terms of correlative strength for the three population groups, in the atlanto-occipital joint. A direct relationship was established within the neural canal from foramen magnum up until C2 for all three population groups. A clear platform is created for future research into constructing regression formulae for matching skulls with long bones. The articular facet and neural canal results can be used in a combined assessment for matching a skull with a body that has an intact cervical spine, by developing a regression model from a grouping of both measurement sets. These regression models may then be implemented in the sorting of comingled remains in situations such as mass graves and mass disasters.
- ItemDefining a method to predict mouth morphology in edentulous skulls(Stellenbosch : Stellenbosch University, 2022-04) Daniels, Luke-John; Alblas, Amanda; Smith, Kathryn; Roberts, Tina; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.ENGLISH ABSTRACT: Forensic facial depiction (FFD) is the process whereby a face is modelled to depict a face from an unknown deceased individual’s skull to assist with human identification. The field of FFD that has not been researched extensively, is the edentulous mouth, where edentulism refers to the condition of not having teeth. Therefore, this study attempted to establish whether a method could be produced to predict edentulous mouth morphology for FFD practice. To achieve this, Pearson’s correlation analysis was used and the relationship between the individual’s soft tissue measurements (somatometry) and skull measurements (osteometry) were analysed. Dentate patients, those with teeth, were also included in the study to understand the morphometric difference between the mouths of dentate and edentulous patients. Cone Beam Computer Tomography (CBCT) scans of n=63 patients were retrieved. This included 40 dentate patients (n=24 males and n=16 females) and 23 edentulous patients (n=7 males and n=16 females). The patients’ CBCT scans were retrieved from the Oral Health Centre of the University of the Western Cape’s Picture Archiving and Communication System. The morphometrics software, Stratovan CheckpointTM, was used to perform osteometry and somatometry on these scans. The somatometry of all patients included measuring soft tissue thicknesses (STTs) of the upper mouth as well as the patients’ lip height (LH) and philtrum length (PL). For the edentulous patients, the STTs included the mid-philtrum (H), and mid- upper lip margin (I). For the dentate patients, the STTs measured were the H, I, the upper incisor (II) and lateral supra-labiale (F). For osteometry, all patients’ skulls were measured to retrieve the following skull lengths: the bizygomatic breadth, basion-prosthion length, basion- gnathion length, maxillo-alveolar breadth, maxillo-alveolar length, nasion-prosthion, and the cranial base length. These lengths were then used to calculate the maxilla-alveolar (MAI), upper facial, subnasal gnathic (SGI), and gnathic indices. A Shapiro-Wilk test was performed, and it was found that all osteometry and somatometry were normally distributed. Therefore, the correlation analysis could be applied. For the edentulous patients, the correlation analysis was only applied to the female patients since the male group was below the suggested sample size for correlation analysis (n<10). The results found that no significant correlations exist between female edentulous mouth somatometry and osteometry. For the dentate males, significant correlations were identified in: the MAI, and II- right and II-left; GI and H; and SGI and LH. For the dentate females: SGI, and II-left, F-left, and LH. Based on this study, it cannot be concluded that osteometry is a good predictor of edentulous mouth morphology. Other factors may play a role in the results of this research such as the sample size and certain edentulous anomalies, for example, residual ridge resorption (RRR). In the dentate group, significant correlations were found since RRR did not affect these patients. Therefore, for future studies, it is suggested that a larger sample is retrieved that is strictly controlled for edentulous anomalies.
- ItemHyperglycaemia and its implication on the Pancreatic islet microvasculature in diabetic rat models(Stellenbosch : Stellenbosch University, 2020-12) Ngounou, Eleonore; Alblas, Amanda; Baatjes, Karin J.; Greyling, Linda Magdalena; Page, Benedict; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.SUMMARY BACKGROUND: Despite the considerable progress made in the treatment of diabetes mellitus, vascular damage remains the leading cause of patient death. The mechanisms underlying vascular abnormalities in obesity and diabetes mellitus remain to be elucidated and may be the main cause of β-cell death. In addition, the detailed description of islet microvasculature in the pancreas is lacking in the literature; therefore, a better understanding of the characteristics of the blood vessel and the factors that maintain β-cell function is needed in clinical practice. OBJECTIVE: To describe the spatial distribution and histomorphology of islet microvasculature under the effect of hyperglycaemia in two experimental diabetic models. METHODS: Eight week old male Wistar rats (n=50) were divided into two groups that received either a standard diet (RAC) (n=20) or a high-fat diet (HFD) (n=30) for two weeks. By the end of the two weeks, altered glucose uptake was confirmed in the HFD group by an oral glucose tolerance test (OGTT). A subgroup (RAC / STZ) of the RAC group (n=10) and another (HFD / STZ) of the HFD group (n=10) then received 50 and 35mg/kg of body weight (BW) of streptozotocin (STZ) to induce type I diabetes mellitus and type II diabetes mellitus, respectively. They were kept diabetic for an additional eight weeks. The body weight and blood glucose (BGL) of the animals were recorded throughout the experimental period (88 days). Blood was collected for flow cytometry and Luminex assay before half the number of animals were sacrificed for pancreatic tissue collection for histological procedure. The remaining half was used to replicate (cast) the pancreatic vasculature by perfusion with polyurethane-based casting resin (PU4ii). Haematoxylin and Eosin (H&E) stained sections were used to assess the general morphology of pancreatic tissue. Methenamine silver and immunostaining using CD34 antibody, delineated the basement membrane and endothelial cells, respectively, of islet microvasculature. A digital camera and a nano-computed tomography (nano-CT) scanner made it possible to generate digital and 3D images. Quantitative evaluation of topographic morphometric parameters of the pancreatic vascular network in the duodenal and splenic regions of the pancreas in each experimental condition was performed using the imageJ and Volume Graphics VGStudioMax 3.0®. Reconstruction of the pancreatic vascular network was attempted using the vascular tree scale laws. RESULTS: A significant increase in the mean body weight was accompanied by a slight increase in mean BGL within 2 weeks in HFD. Streptozotocin caused the development of two diabetic models with all clinical symptoms (polyuria, polyphagia, high BGL (> 28mmol/L) and a significant decrease in body mass in both diabetic groups (26.68% and 15.54% in RAC / STZ and HFD / STZ respectively). The results of the flow cytometry and the Luminex assay validated the presence of islet vascular lesions in animals, which also justified the significant necrosis of endothelial cells, a decrease (p<0.05) in the mean percentage of the stained area of CD34 pixels in islets, and thickening of the basement membrane. The scaling law was used to obtain the relationships between 1) the length and volume of the pancreatic vascular tree up to capillary level (R2=0.693±0.053), 2) the diameter of the lumen and the blood flow in each pancreatic vascular branch (R2=0.988±0.055), and 3) the diameter and length of the branches of the vessels (R2=0.838±0.0123). CONCLUSION: This investigation has established detailed morphological features of the vasculature of the pancreas in the duodenal and splenic regions in normal and diabetic rat models. There were large differences in the structure of the pancreatic vasculature between the two regions appearing to be dictated by metabolic demand. However, there are still challenges in 3D visualisation of the capillary networks of the pancreatic vascular tree, which was the main limitation of this study.
- ItemMorphological assessment of disease and metabolic disorders in a Western Cape skeletal population(Stellenbosch : Stellenbosch University, 2016-12) Walters, Jacklynn; Greyling, Linda Magdalena; Alblas, Amanda; Stellenbosch University. Faculty of Medicine and Health Sciences (Department of Biomedical Science)ENGLISH ABSTRACT : Amongst others, disease, pathology, metabolic disorders and other traits, can be investigated after death by examination of skeletal remains. The evaluation of lesions resulting from disease and metabolic disorders in the Kirsten Skeletal Collection will allow for a better understanding of the effects of disease on skeletal material and of the social development and adaptation of a 20th century population group who, prior to death, inhabited the Western Cape region. The aim of this research was to describe and evaluate the presentation of skeletal pathology resulting from disease and metabolic disorders in the Kirsten Skeletal Collection at Stellenbosch University. A total number of 300 skeletons were studied. The male to female ratio for the study was 2:1, and the majority derived from the mixed population/Cape Coloured group (n=209). Three different examination methods were used in order to identify traits of diseases or disorders on the skeletal material. Macroscopic evaluation of skeletal material was done by examining each skeletal element under a magnifying lamp. Microscopic analysis was done by using dry bone histological techniques to create bone sections which were examined under a light microscope with POL contrast. Lastly, full body x-rays from each skeleton were taken using the Lodox® Statscan® imaging system and radiographs were examined with the help of a musculoskeletal radiologist. Congenital and acquired malformations occurred in 45.7% (n=137) of skeletons. These included sacralisation (11.9%), lumbarisation (7.3%), spina bifida (14.0%), scoliosis (4.7%), kyphosis (17.0%), and spondylolysis (2.7%). Infectious diseases presented mostly as a periosteal reaction on skeletal elements. Visually recognisable periostitis occurred in 60.7% of skeletons with 29.3% of skeletons showing visceral periosteal rib lesions. Metabolic disorders were observed in 72.0% of skeletons and included porotic hyperostosis (10.7%), cribra orbitalia (35.6%), enamel hypoplasia (43.8%), Harris lines (24.3%) and osteoporosis (41.3%). The males in the study population showed a statistically significantly higher prevalence for cribra orbitalia than the females. Signs observed for degenerative bone disease included vertebral osteophytes (81.0%), peripheral osteophytes (43.0%), Schmorl’s nodes (9.3%), and diffuse idiopathic skeletal hyperostosis (5.7%). Neoplasms were observed in 23.3% of the skeletons examined and included primary benign bone tumours (17.7%), primary malignant bone tumours (1.0%), and secondary skeletal metastases (5.3%). Neoplasms observed showed a similar prevalence as previous studies. Paget’s disease occurred in four skeletons. An important finding in the present study was the high prevalence of periostitis in the mixed population group which was ascribed to a variety of factors including unsanitary living environments, malnutrition, alcohol abuse and lack of effective medical treatment. Pulmonary infections such as tuberculosis (TB) contributed to a high prevalence of visceral rib lesions; however, this study did not find visceral rib lesions to be pathognomonic of TB. The present study also showed metabolic disorders indicating periods of stress throughout life such as malnutrition and infectious diseases. Results on cribra orbitalia (males affected more than females) contradicted previous literature and the iron deficiency anaemia theory, suggesting that other factors contributed to the presentation of cribra orbitalia. To the author’s best knowledge, this was the first in depth study using a combination of three different methods to evaluate disease presentation of a skeletal collection representative of the inhabitants of the Western Cape, therefore, giving a unique interpretation of the health status of this population.
- ItemPelvimetry of Males from the Western Cape with Rectal Cancer: Anatomical and Clinical Implication(Stellenbosch : Stellenbosch University, 2020-12) Lathe, Stephanie; Baatjes, Karin J.; Forgan, T. R.; Alblas, Amanda; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.ENGLISH ABSTRACT: Colorectal cancer represents an increasing healthcare burden that affects South African males more commonly than females. Surgical intervention, and specifically total mesorectal excision (TME), remains a key modality in the management of rectal cancer. This procedure occurs in the spatially restricted pelvic canal. Observations of increased difficulty during TME on South African males at the Tygerberg Academic Hospital (TH) led to the impression that they display an especially narrow pelvis. Multiple evolutionary factors, such as childbirth, thermoregulation, and bipedal locomotion, have moulded the size of the modern human pelvis, with males naturally displayinga narrower pelvis than female. Climate is geographically structured and is believed to play a pivotal role in pelvic dimensions. Population groups from lower latitudes tend to exhibit a narroweranddeeperpelves compared to those from higher latitudes.The primary aim of the study was to measure the dimensions of the bony pelvis in males from the Western Cape who have undergone potentially curative colorectal cancer surgery at TH, and to compare these results with other ecogeographical regions. Secondarily, it aimed to determine if an association exists between pelvic dimensions and morbidity documented in rectal cancers patients who have undergone a TME at TH.Pelvic size was investigated by conducting nineteen pelvimetric measurements on 3D bony pelvic reconstructions of male patients (n=158) using computed tomography data. Thereafter measurements were compared with other ecogeographical regions to investigate our relative pelvic size and relationships between latitude and pelvic dimensions using forest plots. Lastly, aone-way ANOVA with a post hoc Bonferroni test was performed to determine if significant differences occur in pelvic measurements among different groups of surgical complications. This population was found to display a relatively narrow transverse pelviccanal when compared to populations from higher latitudes, which was accompanied by an increase in anteroposterior dimensions of the canal. Some measurements were found to follow expected ecogeographical patterns. Significant differences inthe inlet anteroposterior measurement were found among patients in some surgical complication groups. However, no relationship between pelvic dimensions and patient morbidity was found.