Masters Degrees (Clinical Anatomy)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/3551

Browse

Now showing 1 - 20 of 29

Accurate estimation of large vessel length in growing children and adolescents for the purpose of pulse wave velocity calculation.
(Stellenbosch : Stellenbosch University, 2018-12) Witbooi, Lee-Roy Cecil; Innes, Steve; Page, Ben; Pitcher, Richard; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology.
Background Cardiovascular disease is a major cause of death in adults worldwide. Early detection allows for early intervention to prevent vascular events such as strokes, heart attacks, etc. Although these vascular events typically occur in late adulthood, the underlying atherosclerosis often begins during childhood. Early subclinical atherosclerosis can be detected by measuring the elasticity of the large arteries, particularly when performed serially over time. Normally, the elasticity of a healthy aorta helps to slow down the speed of the pressure wave created by contraction of the heart muscle. This is an important way of maintaining smooth laminar blood flow. Atherosclerosis causes the vessel wall to harden and lose elasticity. As the vessel wall hardens, the speed of the pressure wave increases. Pulse wave velocity (PWV) is a sophisticated method of detecting early elasticity changes, and is a preferred non-invasive technique to measure arterial wall stiffness. The velocity calculation requires accurate measurement of both distance travelled and time taken for the pulse wave to travel between two points. The distance used for pulse wave velocity calculation is an approximation of the intraluminal distance travelled by the pulse wave and is estimated by measuring the distance between various surface anatomy landmarks. The expert consensus document on arterial wall stiffness described carotid–femoral PWV as the “gold standard” measurement of arterial wall stiffness, yet there is no consensus on the arterial path length estimation method. A variety of arterial path length estimation methods exist, and this makes inter-study comparison of PWV very difficult. The purpose of the current study was to investigate the most accurate method of estimating the true distance travelled by the aorto-femoral pressure wave. We compared distances between a range of commonly used surface anatomy landmarks, and compared these to the true intraluminal distance measured on multi-planar reformations of archived computerized tomography imaging in children of varying ages. Our findings will allow standardization of PWV calculation in children and allow for inter-study comparisons. Methods Vessel lengths in children (aged 0-18 years) were measured with multi-planar reformation (MPR) imaging software. These measurements were then compared with the surface anatomy measurements also obtained using the MPR imaging software. The comparisons between vessel lengths and surface anatomy distances were performed in segments, since there were no whole body CT scans available on the Picture Archiving and Communication System (PACS) at the research site. Results The surface anatomy measurements from the suprasternal notch to the angle of the mandible (on the right) correlated well with the intraluminal vessel length from the origin of the brachiocephalic trunk to the external carotid at the angle of the mandible (r2=0.92; p<0.0001). The surface anatomy measurements from the suprasternal notch to the midpoint of the right inguinal crease, correlated well with the intraluminal vessel length from the origin of the brachiocephalic trunk to the right femoral artery at the right inguinal ligament (r2=0.98; p<0.0001). The surface anatomy measurements from the suprasternal notch to the xiphisternum, plus the surface distance between xiphisternum and the umbilicus, plus the surface distance between the umbilicus and the midpoint of the right inguinal crease, correlated well with the intraluminal vessel length from the origin of the brachiocephalic trunk to the right femoral artery at the right inguinal ligament (r2=0.97; p<0.0001). The surface anatomy measurement from the suprasternal notch to the xiphisternum, plus the surface distance between the xiphisternum and the midpoint of right inguinal crease, correlated well with the intraluminal vessel length from the origin of the brachiocephalic trunk to the right femoral artery at the right inguinal ligament (r2=0.97; p<0.0001). A regression equation is provided for each set of surface anatomy measurements, allowing further adjustment of measurements to more accurately represent the true intraluminal distance travelled by the pulse wave. Conclusions The surface anatomy distance between the suprasternal notch and the angle of the mandible, subtracted from the distance between the suprasternal notch and mid-inguinal crease, provides the closest approximation of true intraluminal distance travelled and would be the best method to standardize pulse wave velocity calculation in children and adolescents. However, surface anatomy estimations using the xiphisternum and umbilicus as landmarks produced very similar correlations.
Anatomical variation of the carotid bifurcation in a Stellenbosch University cadaver cohort
(Stellenbosch : Stellenbosch University, 2019-04) Dreyer, Rita Liezl; Page, Benedict; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.
ENGLISH ABSTRACT: The carotid bifurcation is the point where the common carotid artery bifurcates into the internal and external carotid artery. A precise anatomical knowledge of the carotid bifurcation is required for various medical specialities. The anatomy of the carotid bifurcation influences the risks, location and prognosis of related pathology. Furthermore, the anatomy of the carotid bifurcation affects treatment as it determines which surgical techniques can be used in an area of high risk. The aim of the study was to determine the anatomical variations of the carotid bifurcation in a Stellenbosch cadaver cohort. One hundred and twenty-eight specimens were examined. This research focuses on the height, angle, general structure, and diameters of the carotid bifurcation, as well as the length and diameter of the carotid sinus. The internal anatomical variation of the carotid bifurcation was added as the study progressed. This study used the gonion as the landmark when measuring height. The Stellenbosch cadaver cohort had a high frequency of high bifurcation with the mean distance of 2.12 cm on the right and 2.06 cm on the left. The angle of bifurcation was 18.53° on the right and 20.24° on the left and was smaller than previous reports in the literature, which ranged between 51-67°. Females had a higher bifurcation and larger angle of bifurcation than males. Sex affected the correlation between angle and height of the bifurcation. The general structure correlated with the standard description and was not influenced by other factors pertaining to the carotid bifurcation, sex or age. Kinks were found in the internal and external carotid artery. The diameters of the carotid bifurcation were larger on the left than on the right. The height of the bifurcation did not influence the probability of kinks in this study, contrary to the literature. The diameters of the internal, external and common carotid arteries in addition to the carotid sinus diameter were larger on the left side and in males. The external carotid had the weakest correlation with the other diameters, which was due to the external carotid artery’s embryological origin. The length of the carotid sinus was 1.74 cm on the right and 1.83 cm on the left. The diameters and the length of the carotid sinus was larger in the males. All external variation slightly increased with age over time as the elasticity of arteries decreased. A variation of the flow diverter was observed in 59% of the cadaver cohort. Supplementary flow diverters were a rare abnormality observed in the internal, external and common carotid arteries. The reason for the carotid bifurcation to present with supplementary flow diverters is still up for debate as this has not been observed in living patients; however, a pathological origin was suggested. Folds in the common carotid were observed. Internal anatomical variation was not affected by external variation or age; however, men had a higher probability of presenting with variation. The Stellenbosch cadaver cohort illustrated variations in the carotid bifurcation which was population-specific. Sex influenced various aspects and correlations of the carotid bifurcation, which means discrepancies can occur and should be considered. Further studies on the carotid bifurcation are needed.
Ancillary methods to improve diagnostic accuracy of thyroid nodules on fine-needle aspiration cytology smears
(Stellenbosch : University of Stellenbosch, 2007-12) Van Wyk, Christine; Louw, Mercia; Wright, Colleen; University of Stellenbosch. Faculty of Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology.
Thyroid nodules are a common clinical problem encountered by physicians, surgeons and radiologists who deal with the head and neck region. However, most follicular lesions of the thyroid are benign, so that the indications for surgery should be as accurate as possible. The morphological difficulty on fine-needle aspiration biopsy (FNAB) of reliably distinguishing preoperatively between benign and malignant lesions has led to a search for ancillary methods that can assist with the diagnosis. The aim of the first study was to develop a cytological scoring system to improve diagnostic accuracy of fine-needle aspiration biopsy of papillary carcinomas with special reference to the follicular variant of papillary carcinoma. The objective of the second study was the application of immunodiagnostic markers Galectin-3 and HBME-1 to histology tissue sections and their corresponding fine-needle aspiration cytology smears to assess their value in distinguishing benign from malignant thyroid lesions. In the first study 16 different cytological features such as background, architecture and cellular morphology were quantatively assessed and scored. Only 14 of the 16 variables were statistically significant. The statistical analysis demonstrated that a score ≥ 4 was indicative of a papillary carcinoma with a sensitivity of 96%. A score < 4 suggested a benign multinodular goiter with a specificity of 97%. In the second study Galectin-3 and HBME-1 were applied to histology tissue sections and their corresponding fine-needle aspiration cytology smears. Statistical analyses showed that the sensitivity of immunohistochemistry for diagnosing malignancy was better than the immunocytochemistry, but the specificity of immunocytochemistry was superior. Furthermore the diagnostic accuracy of immunohistochemistry (86%) and immunocytochemistry (88%) using co-expression of these two antibodies was excellent. In this study on immunocytochemistry, papillary carcinomas were clearly identified with a 100% co-expression in the classic and 71% in the follicular variant of papillary carcinoma. For the surgeon the identification of papillary carcinoma is critical, as this determines the extent of surgery. Similary, the confirmation of a non-neoplastic lesion may prevent surgery. In most cases follicular neoplasms, benign or malignant, will usually be excised for histopathology, prior to definite therapy. These studies show that the implementation of ancillary methods such as a scoring system and immunodiagnostic markers can improve the diagnostic accuracy of thyroid fine-needle aspiration biopsies in our laboratory. This may lead to better management of thyroid nodules. However, it is advisable that cytopathologists always take all the clinical features and image analyses into consideration before making a diagnosis.
The antidiabetic and antioxidant properties of Athrixia phylicoides aqueous extract : an in vitro and ex vivo assessment
(Stellenbosch : University of Stellenbosch, 2011-03) Chellan, Nireshni; Muller, Christo John Frederick; Page, Benedict; De Beer, Dalene
ENGLISH ABSTRACT: Introduction: Athrixia phylicoides is an aromatic, indigenous shrub with high antioxidant content and numerous indigenous medicinal properties inferred by ingestion of an herbal brew of the plant. Commercialization of “bush tea” (derived from A. phylicoides) holds economic and developmental potential for indigenous communities provided the safety and efficacy of the herbal tea is established. Recently A. phylicoides has been shown by McGaw et al. (2007) to have similar antioxidant activity to Rooibos tea, and a unique, new flavonol (i.e. a polyphenolic antioxidant plant metabolite) 5-hydroxy-6,7,8,3′,4′,5′-hexamethoxyflavon-3-ol, unique to A. phylicoides, was isolated by Mashimbye et al. in 2006. With changes in the socio-economic climate and a new trend in merging Western lifestyle with traditional practices, new interest has been shown in herbal/natural remedies. Study Aim: The aim of this study was to firstly, determine the in vitro effect of A. phylicoides aqueous extract on glucose metabolism in cell lines that mimic the three key organs implicated in glucose homeostasis. Secondly, the study aimed to determine the potential ex vivo antioxidant and anti-inflammatory effect of the extract in pancreatic β-cells and peripheral mononuclear cells respectively. Methods: Leaves and fine twigs of A. phylicoides were processed into an aqueous extract. C2C12, Chang and 3T3-L1 cells were cultured under standard conditions and acutely exposed to increasing concentrations of extract and water vehicle, as well as 1 μM insulin and metformin as positive controls. Glucose uptake from 8 mM glucose culture media was determined using a fluorimetric oxidase method. Radioactive 14C-glucose oxidation to 14CO2 and determination of glycogen content of cells were used to assess the fate of intracellular glucose. RT-PCR was used to assess the extract effect on insulin-signalling gene expression. The antioxidative effect of A. phylicoides extract in pancreatic β-cells isolated from Wistar rats was determined by measuring nitric oxide (NO) production in response to hyperglycemic conditions. NO was labelled with diaminofluorocein diacetate and fluorescence was measured using flow cytometry. Insulin secretion of pancreatic β- cells was measured using radio-immuno assay. The anti-oxidative effect of the extract in lipopolysaccharide-stimulated peripheral mononuclear cells isolated from Wistar rats was determined by measuring the production of TNF-α using an ELISA kit. Results: C2C12 myocytes showed maximal increased glucose uptake at the 0.05 μg/μl extract concentration (228.3% ± 66.2, p<0.001). In Chang cells, A. phylicoides extract maximally increased the amount of glucose taken up at the 0.05 μg/μl concentration (134.5% ± 2.5, p<0.05). In 3T3-L1 cells, the extract maximally increased the amount of glucose taken up at the 0.025 μg/μl concentration (143.5% ± 10.3, p<0.001). An extract-induced increase in insulin receptor and glucose transporter four expression was seen in C2C12 myocytes. The oxidation of 14C-glucose to 14CO2 by C2C12 myocytes was maximally increased following acute exposure to the extract at 0.1 μg/μl (2919.3 fmol/1x10^6 cells ± 428, p<0.01). The oxidation of 14C-glucose to 14CO2 by Chang cells was maximally increased following acute exposure to extract at 0.1 μg/μl (4476.7 fmol/1x10^6 cells ± 1620, p<0.05); as seen in the C2C12 cells. A. phylicoides extract increased glycogen storage at all three concentrations tested in Chang cells, but maximally at the 0.025 μg/μl concentration (13.6 μg/1x10^6 cells ± 0.7, p<0.05). A. phylicoides extract did not have any measurable effect on the oxidative status of β-cells or the anti-inflammatory status of peripheral mononuclear cells. The extract did show an increase in first phase insulin secretion of β-cells in hyperglycemic conditions, although it was not significant. Conclusion: Athrixia phylicoides aqueous extract stimulates in vitro glucose uptake and metabolism in an insulin-mimetic manner, suggesting that this extract could potentially be beneficial to type two diabetics as an adjunct therapy.
Beta secretase regulation and inflammation in pancreatic β-cells: the potential role of Rooibos
(Stellenbosch : Stellenbosch University, 2018-12) Burger, Joleen; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology.; Chellan, Nireshni; Lopes, John; Muller, Christo J.F.
Introduction Chronic, low-grade inflammation is a hallmark of insulin resistance (IR) and underlies pancreatic β-cell failure and the development of type 2 diabetes (T2D), a disease characterized by a reduction in β-cell functional mass. However, therapeutics that directly protect β-cells from stressors, such as inflammation and oxidative stress, are limited. Amylin, a neuro-hormone, is co-secreted with insulin, therefore hyperinsulinemia often coincides with hyper secretion of amylin. Increased secretion of amylin is associated amyloid deposition which have detrimental effects on β-cell function. In pancreatic islets, β-secretase (BACE) modulates the deposition of cytotoxic islet amyloid, an initiator of intra-islet inflammation and oxidative stress, making BACE inhibition a therapeutic target. Insights into mechanisms involved in islet inflammation and the associated effect(s) of BACE, may reveal an opportunity to develop novel therapeutics to protect and preserve β-cells in T2D. In addition to their antidiabetic properties, aspalathin (Asp), Z-2-(β-D-glucopyranosyloxy)-3-phenylpropenoic acid (PPAG), and an unfermented Rooibos extract (GRT) may have anti-inflammatory effects in β-cells and may additionally modulate BACE activity. Aim To determine if GRT or two of its most bioactive polyphenols have BACE inhibition activity and can reduce pro-inflammatory effects in rat insulinoma (INS1) pancreatic β-cells. Methods A model of moderate inflammation was established in INS1 cells using a cytokine cocktail, containing tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interferon-γ (IFN-γ). Rat insulinoma cell viability, function, and oxidative stress was measured in response to the cytokine cocktail and exposure to Asp, PPAG, and GRT by quantifying cellular adenosine triphosphate (ATP) production, cell death via apoptosis and necrosis, proliferation rate, insulin/amylin secretion and content, reactive oxygen species (ROS) production and nitrate (NO2-) generation. Beta secretase inhibition profiling of GRT, Asp, and PPAG was assessed using fluorescence resonance energy transfer (FRET) in a purified enzyme assay, followed by kinetically assessing BACE activity in vitro. Results The cytokine cocktail induced a state of moderate inflammation after 24 hours, mainly through IL-1β. High concentrations of Asp (1000 μM) and moreso, GRT (1 mg/ml), showed a trend towards BACE inhibition compared to controls (56.20% ± 2.05, p<0.0001 and 39.80% ± 0.55, p<0.0001), but reduced mitochondrial dehydrogenase activity in inflamed INS1 cells (19.02% ± 2.98, p<0.0001; 36.88% ± 1.53, p<0.0001), while PPAG showed no measurable effect. Lower concentrations of Asp (0.1–10 μM), PPAG (0.1–10 μM), and GRT (0.0001-0.01 mg/ml) may have a protective effect on inflamed pancreatic β-cells as an increase, albeit not significant, in overall cell viability and function was observed, with a concomitant decrease in oxidative stress after 24 hours (97.66% ± 3.5, p<0.66; 95.54% ± 5.61, p<0.52; 96.80% ± 3.67, p<0.55).
The characterisation of candida isolates from the oral cavities of a group of acute leukemia patients
(Stellenbosch : Stellenbosch University, 1997-12) Paul, Lynthia Vivienne; Hauman, C. H. J.; Warren, R.; Van Wyk, C. W.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences : Anatomy and Histology
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die invloed van chemoterapie en antifungale terapie op Candida spesies in die mondholte van 29 leukemie pasiënte te ondersoek. Smere en mondspoele was geneem van die pasiënte. Candida isolate was op Sabouraud dekstrose agar sowel as differensiële media gekweek. Isolate was geïdentifiseer met behulp van fenotipiese eienskappe asook koolhidraat assimilasie profiele. Genotipering van C. albicans stamme was gedoen met behulp van die C. albicans spesie-spesifieke peiler, Ca3.
Clinical implications of the variations of sciatic nerve bifurcation on the popliteal nerve block
(Stellenbosch : Stellenbosch University, 2018-12) Mady-Goma, Chancy Rosine; Tchokonte-Nana, Venant; Stellenbosch University. Faculty of Health and Medical Sciences. Dept. of Biomedical Sciences. Anatomy and Histology.
ENGLISH ABSTRACT: The sciatic nerve (SN) is a major nerve of the lower limb, innervating the posterior thigh, the hip and knee as well as structures below the knee through its branches. The SN division occurs in the popliteal fossa (PF) at the level of the knee. However, various studies report great variations in the level of division of the SN, ranging between 3.3 and 65.1%. These variations were suggested as a possible cause in failures of the popliteal block (PB). Therefore, the aim of this study is to describe the level of division of the SN in a South African cohort and to evaluate the success rate of three approaches to the PB. Following the simulation of the PB in 22 lower limb specimens, the popliteal fossae of 61 cadavers were dissected and the sciatic nerve properly exposed. The level of division was described and the location and distance between the dye and the nerve measured. Variations represented only 11.48% of cases, similar to textbooks’ description (12%). The bifurcation pattern of the SN in this South African cohort was therefore comparable to the standard one. The distance between the SN and the PC varied between 20 mm and 405 mm, with a median of 55 mm, close to 60 – 70 mm found in most studies. The prevalence of variations was higher in females (ratio F:M=2.78) and 55.56% were bilateral. With the SN dividing in the PF, the simulation predicted a 100% success rate with no difference between the approaches used. Nevertheless, a higher division of the SN would compromise the success of the block. Overall, the SN division in our study population follows the normal pattern with a lesser degree of variations (11.48%). The division of the nerve in the PF might ensure a successful block in 95 to 100% of cases, in contrast to cases of high variations. Nevertheless, a preoperative imagery is strongly recommended, especially in women for early identification of variations to avoid failures of the PB, irrespective of the approach used.
The comparative functional anatomy of the forelimb in two african mole-rat species, bathyergus suillus and heterocephalus glaber.
(Stellenbosch : Stellenbosch University, 2021-12) Doubell, Narusa Suria; Kotzé, Sanet H.; Sahd, Lauren; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology. Division of Clinical Anatomy.
ENGLISH ABSTRACT: Different digging and communication methods are observed in various subterranean mole-rat species. Seismic signalling in the form of hind foot-drumming is the main communication method in most solitary mole-rat species, such as the scratch-digging Bathyergus suillus. The aim of the present study was to determine if hind foot-drumming and scratch-digging influence the morphology of the fore limb muscles in a drumming, scratch-digging species, B. suillus, belonging to the family Bathyergidae and a non-drumming, chisel-tooth digging species, Heterocephalus glaber belonging to the family Heterocephalidae. Furthermore, the secondary aim was to determine if somatosensory mechanisms that may be responsible for the detection of seismic signals could be identified histologically in the foot pads and lateral aspect of the feet in both species. Four muscle architecture parameters were measured and compared in 40 formalin-fixed muscles from the right forelimb of each species (n=6). The composition of type I and II fibres as well as the glycolytic, oxidative glycolytic and oxidative fibres in 21 forelimb muscles were histochemically and immunohistochemically determined in six fresh B. suillus and six fixed H. glaber specimens. The densities of Pacinian corpuscles, Merkel cells, Ruffini corpuscles and Meissner corpuscles were determined within the footpads and the morphology of the robust hairs on the lateral aspect of the feet was described. Muscles involved in the power stroke of digging had higher muscle mass percentage, force output and shortening capacity in B. suillus compared to H. glaber. Significantly higher percentages of glycolytic fibres were observed in the scapular elevators and digital flexors of B. suillus. These results suggest that the forelimb muscles involved in digging in B. suillus provide fast and powerful motions for effective burrowing. The m. sternohyoideus had significantly more oxidative fibres in H. glaber compared to B. suillus. Furthermore, the m. sternocleidomastoideus in H. glaber had significantly higher physiological cross-sectional area (PCSA) and fascicle length values compared to B. suillus. Regionalisation of type I and II fibres was observed in the m. claviculo-scapularis of B. suillus and m. triceps brachii caput medialis in H. glaber. Significantly higher densities of Meissner corpuscles in the drumming B. suillus suggests that this somatosensory mechanism in their footpads may be responsible for detecting seismic signals. The hairs on the lateral aspect of the feet did not have the typical follicle-sinus complex seen in sensory hairs. However, Merkel cells within the outer root sheath and the nervous tissue surrounding the hairs in both species are indicative of functioning either as tactile perception for movement in burrows or moving loosened soil around within the burrows. Stellenbosch University https://scholar.sun.ac.za iv In conclusion, the differences in the muscle architecture and muscle fibre typing between the two species may reflect adaptations for scratch-digging and production of seismic signals in B. suillus. Additionally, the muscle architecture and fibre type compositions in the neck muscles of H. glaber may point toward faster contractions for chisel-tooth digging. However, the phylogeny of the two species may also be responsible for these differences and not just behavioural demands such as hind foot-drumming and digging methods.
Congenital anomalies in the vertebral column associated with thoracolumbar transitional vertebrae
(Stellenbosch : Stellenbosch University, 2017-11-08) Du Plessis, Anneli Merle; Greyling, Linda Magdalena; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Division Anatomy and Histology.
ENGLISH ABSTRACT : According to Byrd & Comiskey (2016), disrupted ossification during development results in abnormal skeletal development. A study conducted on congenital anomalies by Masnicová & Beňuš (2003), stipulated that most skeletal congenital defects are located in the vertebral column. The most common skeletal defects of the vertebral column are neural tube defects (NTD’s), spondylolysis and cranial-caudal border shifts (Masnicová & Beňuš 2003). In reviewed literature, case studies have reported various congenital defects that are simultaneously present within the vertebral column of an individual. There is, however, a lack of evidence to substantiate whether the mutually inclusive observations resulted by chance, or whether an association between the defects is present. The aim of this study was to determine whether associations exist among random congenital defects in the vertebral column. The objective of this study was to identify and determine the frequency of random congenital defects from a subset of defects in the vertebral column. A selection of skeletal remains were taken (n=35) from a subset in the Kirsten Skeletal Collection at Stellenbosch University. The subset comprised specimens from the population (N=±1100) with congenital defects in the vertebral column that has a reviewed prevalence of 0.5/1000 worldwide. This study hypothesised that there is an association between random congenital defects that results from border shifts or disrupted neural arch formation. The congenital defects considered in the study included: lumbosacral transitional vertebrae (LSTV), thoracolumbar transitional vertebrae (TLTV), spondylolysis, NTD’s and sacro-coccygeal fusion. Descriptive analysis was performed to determine the frequencies of defects in the selection. The descriptive analyses are illustrated in frequency distribution tables for each type of defect evaluated in the study. This study found that every specimen in the selection had TLTV and one or more additional random congenital defect in the vertebral column. Based on the finding, it can be claimed that an association exists between TLTV and other congenital defects of the vertebral column. TLTV were identified based on intermediary characteristics between the thoracic and lumbar regions present in the vertebra. This study concludes that when TLTV is present, it will be associated with one or more random defect in the vertebral column discussed in this study. The association between TLTV and other congenital defects provides an indirect association between all cases where various congenital defects are simultaneously present.
The 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.
Defining 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.
Description of the cerebral vasculature in a southern African cadaver cohort
(Stellenbosch : Stellenbosch University, 2016-03) Cilliers, Karen; Page, Benedict; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology.
ENGLISH ABSTRACT: Few studies give a complete description on the origin, absence, duplication and triplication of the cerebral cortical branches. The anterior cerebral artery (ACA) varies considerably and this complicates the description of the normal anatomy. The most commonly discussed branching types of the middle cerebral artery (MCA) include bifurcation and trifurcation. Branching of the posterior cerebral artery (PCA) has not been adequately described; only the division level of the parieto-occipital (PoA) and calcarine arteries has been discussed. Anomalies of the cerebral arteries have been reported. To the author’s best knowledge, no previous studies have investigated the anatomy of the cerebral arteries in a Western Cape population. Therefore, the aim of this study is to describe the anatomy and anomalies of the cerebral vasculature in a Southern African cadaver cohort. Twenty hemispheres were used for the pilot study and 126 hemispheres for the present study. These 126 hemispheres consisted of 88 males and 38 females, between the ages of 22 and 84. Specimens were distributed over three population groups, namely, coloured (n=76), black (n=38), white (n=10) and unknown (n=2). The arteries were injected with coloured silicone. The external diameter and length of all the cortical branches of the cerebral arteries were measured using a digital micrometre. The diameter and lengths indicated statistically significant differences on the right and left side, between males and females, different population groups and different age groups. The most commonly absent artery was the callosomarginal artery, and the most commonly duplicated artery was the paracentral lobule artery. The origin of the cortical branches was similar to the descriptions in the literature; however, the common trunks and unusual origins were also noted. The branching pattern of the MCA was classified according to the 11 different subtypes described in the literature. Medial bifurcation was most commonly observed. The branching pattern of the PCA was assessed, and in most cases there was additional branching before the division of the calcarine artery and PoA. Anomalies observed in the present study included bihemispheric ACA (19.8%), median ACA (11.6%) and fenestration of the PCA (1.6%). The only anomaly observed in the pilot study was fenestration of the PCA (5.0%). A shorter trunk may play a role in aneurysm formation, and changes in vessel diameter could indicate early signs of several pathological conditions. Aneurysms can be observed at the branching of cerebral vessels, highlighting the importance of a thorough knowledge of the vascular anatomy. The MCA branching subtypes were described, since only bifurcation and trifurcation are usually noted. Furthermore, the branching pattern of the PCA has not been adequately described in previous reports; therefore the possible branching types were defined. Anomalies of the cerebral arteries are usually only mentioned; therefore the bihemispheric and median ACA were fully described (origin, length, diameter and area supplied). Given the important implications that the anatomical variation of the cerebral arteries
The effect of a high sucrose diet on ovarian morphology : an age-matched generational study
(Stellenbosch : Stellenbosch University, 2019-03) Foiret, Jaudon Ron; Kotze, Sanet; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.
ENGLISH ABSTRACT: Metabolic syndrome (MetS) is rapidly becoming an epidemic in society, affecting between 10% and 40% of Western populations. High-fat and refined sugar diets have been implicated in the increased prevalence of insulin resistance, obesity and dyslipidaemia, the hallmarks of MetS. Risk factors of MetS have been correlated with decreased reproductive potential and suboptimal pregnancy outcomes, while predisposing offspring to a MetS state in adulthood. Therefore, this study aimed to assess the effects of a high-sucrose diet on the reproductive potential and mating outcomes of albino Wistar rats, and their offspring using a foetal programming model. Female nulliparous albino Wistar rats (n=28) were randomly divided into a high-sucrose feed group (HSF) (n=19) and a control-feed group (CF) (n=9). All animals in this study were housed in standard rat cages in a temperature and humidity-controlled environment on a reverse 12-hour dark/light cycle with free access to water and respective feeds. Diets consisted of 68% carbohydrate consisting of either sucrose (HSF) or corn starch (CF). Maternal feeding commenced four weeks prior to mating with unexposed males. Maternal metabolic profile and mating outcomes were recorded. Maternal animals were euthanised and the ovaries harvested immediately after their offspring were weaned. The offspring were randomly divided into three groups; HSF/HSF (pups from HSF dam maintained on high-sucrose feed) (n=6), CF/CF (pups from CF dam maintained on control-feed) (n=6) and HSF/CF (pups from HSF dam and maintained on control-feed) (n=4). Pups were maintained on their respective feed for 10 weeks to achieve an age match comparison with dams. All animal’s ovaries were harvested, formalin-fixed and paraffin-embedded, routinely stained and histologically evaluated for follicle type and numbers, follicle development, and morphological changes. Results indicated no overt hyperglycaemia or obesity in any group, however a significant (p<0.01) decrease in mean body mass (MBM) was observed in the HSF and HSF/HSF groups when compared to their respective controls. Mating was deleteriously affected, with HSF dams birthing fewer and significantly lighter offspring. End point metabolic profiles of pups, indicated no significant differences in fasting blood glucose level, however the HSF/HSF MBM was found to be significantly decreased. An intermediate metabolic profile was observed in the HSF/CF group. Histological examination indicated a significant decrease in numbers of functional follicles in any sucrose feed group, with varying degrees of indicative morphological changes. Metabolic profiles of all animals, although not overtly pathological, displayed dysregulation in energy balance. This is hypothesised to be a result of adaptations in hepatic fructose metabolism and the protective effects of oestrogen. Effects on reproductive potential and ovarian morphology in this study appear to be as result of gonadotropic hormone dysregulation mediated by metabolic status. Foetal programming by means of highsucrose diet was confirmed in this study with HSF/CF being deleteriously affected despite control feed postnatal diet. This study demonstrated the deleterious effects of a high-sucrose diet on maternal reproductive health and its compounding effects on their offspring. Deductions from this research emphasise the importance of maternal diet beyond overt MetS risk factors and can be applied in family planning.
Effects of melatonin on the histomorphometry of the pancreas, liver and kidney of rats on antiretroviral treatment
(Stellenbosch : Stellenbosch University, 2017-12) Truter, Danelle; Kotze, Sanet; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Division Anatomy and Histology
ENGLISH ABSTRACT : The administration of combination antiretroviral therapy (cART) in HIV positive patients has shown to cause side histologically observable effects in the pancreas, liver and kidneys. These conditions include acute pancreatitis, cellular injury, oxidative stress, hepatotoxicity and nephrotoxicity, which presents as inflammation and cellular injury. Melatonin has been successful in the prevention and reduction of inflammatory markers, oxidative stress and cellular damage, and has been observed as a treatment option in various conditions. The aim of this study was to evaluate the observable morphometric changes caused by cART as well as the potential therapeutic effects of melatonin on the pancreas, liver and kidney of the control (C/ART-), cART (C/ART+), melatonin (C/M+) and cART and melatonin (ART+/M+) groups in the absence of HIV in a rat model. Tissue samples (N=40) of the ventral part of the pancreas, the median lobe of the liver and the right kidney male Wistar rats were collected. The blood samples (n=37) were collected from the abdominal aorta after euthanasia. Samples of the pancreas, liver and kidney were stained with haematoxylin and eosin (H&E) and evaluated for histopathology. The pancreas was labelled with anti-insulin and anti-glucagon to determine α- and β-cell areas in the pancreatic islets. Blood samples were collected for liver enzyme tests to evaluate hepatotoxicity. The kidneys were stained with periodic acid Schiff (PAS) and the area, perimeter, diameter and radius of 30 renal corpuscles, with their associated glomeruli and 90 proximal convoluted tubules (PCTs) were measured per rat. The pancreas, liver and kidney showed no significant histologically observable changes in histology. The mean islets per mm2 in the pancreas was significantly higher in the C/M- group than in the C/ART- and ART+/M+ groups. Melatonin stimulated the abundance of pancreatic islets and thus indirectly the availability of α-cells. The haemoglobin value in the C/ART+ group was significantly higher than in the C/ART- group, which indicates that the mechanism in which cART increases serum haemoglobin is possibly still active in the absence of immune compromise. The C/M+ group showed a decrease in serum lipaemia compared to the C/ART- group, due to melatonin’s its inhibitory effect on peroxidation of cellular lipids by free radicals. In the kidneys, all parameters of the renal corpuscle were significantly lower in the C/ART+ and C/M+ groups compared to the C/ART- group. In the glomeruli, some parameters were significantly lower in the C/ART+ group compared to the C/ART-, C/M+ and ART+/M+ groups. The renal space was significantly decreased in the C/ART+, C/M+ and ART+/M+ groups. All parameters of the PCTs were significantly decreased in the C/ART+ group compared to the C/ART- group. All the components of the nephron were affected by cART, which may have caused tubular dysfunction, cellular damage and a decreased estimated glomerular filtration rate (eGFR). In conclusion, cART and melatonin each affected the histomorphometry of the pancreas, liver and kidney in a rat model without immune compromise. This should be considered when medication is prescribed to patients with HIV, specifically in patients with susceptibility to renal injury.
The effects of Rooibos (Aspalathus linearis) supplementation on the pancreas, liver, and kidney of male Wistar rats following antiretroviral treatment
(Stellenbosch : Stellenbosch University, 2017-12-05) Pereira, Daniella Lagoa; Kotzé, Sanet Henriette; Chellan, Nireshni; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Division Anatomy and Histology.
ENGLISH ABSTRACT : The health burden of human immunodeficiency virus (HIV) has improved with the introduction of antiretroviral therapy (ART). Near perfect adherence to ART is needed to ensure the maximum benefits of the drugs. Adherence is compromised by side effects and adverse drug reactions (ADRs) which may, in part, be due to drug induced oxidative stress. Rooibos (Aspalathus linearis) is a shrub-like bush native to South Africa and is cultivated primarily as an herbal tea. Rooibos contains various polyphenols that add to its overall antioxidant capabilities. Aspalathin, the most abundant polyphenol present in rooibos, has shown potent antioxidant capabilities in vitro, providing an attractive model for therapy. The following study questions whether the histological observable effects of ART can be attenuated with the introduction of rooibos tea in vivo. The study aimed to assess the effects of combination ART, and rooibos tea on the histology of the pancreas, liver, and kidney in a HIV-negative rat model. Rats (n=40) were subcatogorised into four groups namely: control (C), control ART (C-ART), control rooibos (C-R), and experimental (ART+R) groups. The C-ART and ART+R groups were administered a dose of combination ART consisting of 200 mg Emtricitabine (EMT), 600 mg Efavirenz (FTC) and 300 mg Tenofovir (TDF). A 2% (w/v) rooibos tea solution was administered ad libitum to C+R and ART+R groups. Samples of rooibos tea were analysed using liquid chromatography-mass spectrometry techniques to determine whether rats received the same concentrations of polyphenols throughout the investigation. Samples from the pancreas, liver, and kidney underwent standard histological processing. Routine haematoxylin and eosin stains and appropriate immunohistochemical and tinctorial techniques were conducted. Detailed morphometric measurements on pancreatic islet size, number and percentage of α and β-cells were performed. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were evaluated to test liver function. Changes in size of the glomerular corpuscle, glomeruli and proximal convoluted tubules (PCT) in the kidney were measured. Organ architecture, cellular structure and associated pathology were analysed in each organ, scored, and confirmed by a histopathologist. The size and number of pancreatic islets and the percentage of α and β-cells did not vary significantly from the control group. Serum AST and ALT levels did not vary significantly from controls indicating normal liver function. Glomerular corpuscle, glomeruli and PCT size remained constant compared to controls. No overt histopathology was present indicative of ART induced pancreatic toxicity, hepatotoxicity or nephrotoxicity. The results indicated no major changes between the various tea solutions indicating that the rats received similar concentrations of rooibos polyphenols throughout the week. The study maintains that ART, when given to rats, does not cause significant changes to organ histomorphometry. While rooibos tea administration did not worsen, or improve organ histomorphometry.
Histochemical properties of the iliocapsularis muscle: implications for hip function.
(Stellenbosch : Stellenbosch University, 2023-03) Mac Dermott, Kerryn-Anne; Keet, Kerri; Kohn, Tertius Abraham; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology. Division of Clinical Anatomy.
ENGLISH ABSTRACT: The iliocapsularis (IC) is a deep skeletal muscle that overlies and attaches to the anteromedial hip joint capsule and is an important anatomical landmark in anterior approaches to hip replacement surgery. Researchers have proposed the IC functions to stabilise the anterior hip joint and limit impingement of the hip capsule, between the femoral head and acetabulum, in hip flexion. However, a conclusive description of the function of the IC is not yet known. This study, therefore, aims to determine the skeletal muscle properties of the IC muscle and to compare these to that of the iliacus (IL) and vastus lateralis (VL). A cross-sectional observational study was conducted on 11 recently deceased unembalmed bodies with a mean age of 83 ± 9 years (range 69 - 95 years). Muscle samples, harvested from the IC, IL, and VL, were analysed for muscle fibre type distribution and fibre cross-sectional area (CSA) using fluorescent immunohistochemistry, while relative mitochondrial density was visualised histochemically using the NADH stain. IC had predominantly type I fibres (63 ± 12%), followed by type IIA (32 ± 13%) and IIX (5 ± 3%) fibres. IL comprised of a similar high distribution of type I fibres (61 ± 8%), compared to type IIA (31 ± 7%) and IIX (8 ± 8%) fibres. Conversely, VL had equal amounts of type I (47 ± 12%) and IIA (40 ± 11%) fibres, with lower proportions of type IIX (13 ± 10%) fibres. No difference in fibre type distributions were found between the IC and IL, whereas VL had less type I fibres compared to the IC and IL. The latter two muscles observed higher relative mitochondrial density (darker fibres) and, therefore, oxidative capacity, compared to the VL with a more equal proportion of light and dark stained fibres. The IC had larger (p < 0.0001) type I fibres (3607 ± 1422 μm2) compared to its type IIA (1849 ± 1306 μm2) and IIX (1379 ± 900 μm2) fibres. Similarly, the IL and VL had larger (p < 0.0001) type I fibres (3320 ± 1182 μm2 and 4235 ± 882 μm2, respectively) compared to type IIA (1790 ± 987 μm2 and 2738 ± 1650 μm2, respectively) and IIX (1428 ± 769 μm2 and 2170 ± 1355 μm2, respectively) fibres. No difference in the CSA of fibre types were found when the IC was compared with the IL and VL. However, the VL reported larger CSA compared to IL for type I and IIA fibres. Mean fibre CSA of the IC and IL were similar in size, while the VL had larger fibres. Fibre type distribution and fibre CSA showed no association with age. Therefore, the predominant oxidative type I fibre distribution of the IC may supports its proposed function to stabilise the hip joint and limit impingement of the hip capsule in hip flexion. Therefore, conclusive knowledge of the function of the IC will allow for more informed decisions regarding patient care and rehabilitation following anterior approaches for hip-replacement surgery.
Histomorphometric effects of an antiretroviral treatment and obesity on the pancreas, liver, kidney and perivascular adipose tissue in a rat model
(Stellenbosch : Stellenbosch University, 2017-12-12) Nel, Simoné; Kotzé, Sanet Henriette; Nireshni, Chellan; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Division Anatomy and Histology.
A histomorphometric study of the effect of Afriplex GRT(TM) on the pancreas, liver and kidney of rats fed a high-fat diet
(Stellenbosch : Stellenbosch University, 2018-12) Layman, Jodie; Kotze, Sanet; Chellan, Nireshni; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences: Anatomy and Histology.
ENGLISH ABSTRACT: Obesity causes a wide range of disorders including insulin resistance, hepatic steatosis as well as renal glomerular and tubular pathology. These disorders are typically associated with oxidative stress and inflammation. Rooibos, Aspalathus linearis, is a South African plant which has antioxidative, anti-inflammatory, antilipidemic, and antihyperglycemic properties as shown in vivo and in vitro. Afriplex GRT™ is an unfermented green rooibos extract which is postulated to have enhanced effects compared to fermented rooibos, mostly due to its high aspalathin content. The present study aimed to determine the ameliorative effects of Afriplex GRT™ on the histomorphometry of the pancreas liver and kidney in a diet-induced obese rat model. Male Wistar rats (N=28) were randomly sorted into four study groups (n=7) namely, control (C), GRT fed control (GRT), high-fat diet (HFD) and HFD supplemented with GRT (HFDGRT). Animals were either fed a control feed or a HFD which contained fat, cholesterol and fructose. Animals in the GRT and HFD-GRT groups were supplemented with Afriplex GRT™ at a concentration of 60 mg per kg body mass per day. Body mass, and pancreatic, liver and kidney mass were determined after which samples were processed to wax. Tissues were sectioned at 4 – 5 µm in thickness and stained using haematoxylin and eosin for analysis by a histopathologist. Immunohistochemistry using anti-insulin and anti-glucagon double antibody labelling was performed on the pancreas. Other staining techniques included Masson’s trichrome, Gordon and Sweet’s reticulin impregnation and periodic acid Schiff. Additionally, frozen sections of the liver and pancreas were stained using Oil red O for lipid infiltration. Morphometric techniques included area, diameter, radii, point counting and ratios. Body mass significantly decreased in the HFD-GRT group compared to the HFD group. Pancreas and kidney mass decreased significantly in the HFD-GRT group compared to the Cgroup, however liver mass significantly increased in both HFD groups. Islet area and β-cell area significantly decreased in the HFD-GRT group compared to all three control groups however, a greater number of islets was observed. Hepatic steatosis and liver pathology were reduced in the HFD-GRT group compared to the HFD group. Renal space and the proximal convoluted tubules were decreased in the HFD-GRT compared to C-group as indicated by trends. Additionally, a trend was observed in the arcuate artery media to lumen ratio which was increased in the GRT group compared to the HFD group. Similar to the present study, a decrease in body mass has been observed with fermented rooibos and its polyphenols in HFD-fed animals. In the HFD-GRT group, increased islets per section area and smaller islet areas are associated with increased insulin secretion, which suggests improved glucose tolerance. This study suggests that Afriplex GRT™ may effectively reduce hepatic steatosis, an effect previously seen in studies on fermented rooibos and rooibos polyphenols. More in-depth studies on the effects of Afriplex GRT™ in the kidney are needed, potentially for a longer study period. Therefore, Afriplex GRT™ has observable ameliorative effects on the histomorphology of the liver and the pancreas; the effects on the kidney requires further investigation.
The iliac and femoral vessels: dimensions and tortuosity in a South African sample.
(Stellenbosch : Stellenbosch University, 2023-02-22) Lunn-Collier, Robyn; Keet, Kerri; Baatjes, Karin; Witbooi, Lee-roy; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology. Division of Clinical Anatomy.
ENGLISH ABSTRACT: Arterial morphology varies between individuals and undergoes changes with increasing age. The safety and success of endovascular procedures, performed by accessing and traversing vessel pathways, are influenced by this variable morphology. Research exploring the iliofemoral arterial pathway is limited in South Africa, which may implicate the efficacy of endovascular procedures performed in this country. Therefore, the present study aimed to determine the mean length, luminal diameter, and tortuosity severity of the common iliac, external iliac, and common femoral arteries of adult males and females in a South African sample, and to determine the influence of increasing age on this arterial morphology. A retrospective, cross-sectional study was conducted using a sample of 224 computed tomography angiograms, accessed from Tygerberg Hospital, Cape Town, South Africa. The sample included 117 adult males and 107 adult females (aged 18-79). The arterial length and lumen diameter of the common iliac, external iliac, and common femoral arteries were measured. Tortuosity severity was assessed by a visual estimation and allocation into a phenotypic category. Furthermore, tortuosity was quantitatively assessed using the tortuosity index and inflection count metric. Regression analysis was used to adjust for estimated body height. The common iliac artery was the widest artery of the iliofemoral pathway, while the external iliac artery was the longest. The morphology of the external iliac artery varied bilaterally and with sex, with males presenting with increased tortuosity, particularly on the right side. The diameter of all arterial segments was larger in males, while the length of these arteries did not differ between the sexes, with the exception of the right external iliac artery being longer in females. The inflection count metric reported the external iliac arteries of males to be more tortuous. Regression analysis revealed a strong positive relationship between arterial tortuosity and increasing age. A tortuosity phenotype was most frequently observed in the external iliac artery. However, a c-shaped curving phenotype of tortuosity was observed in all arteries of interest. The tortuosity severity of the external iliac artery doubled throughout the adult lifetime, with increases in arterial tortuosity and changes in morphology commencing between 40-49 years of age. Severe tortuosity was typically reported in individuals aged 60 years and older. Arterial morphology of the iliofemoral pathway is variable both bilaterally and between the sexes. Furthermore, changes in arterial morphology become significant from 40-49 years of age and are most severe after 60 years of age. Thus, the vasculature of patients within this age range may present with challenging anatomy for endovascular procedures. Comparing the arterial dimensions and tortuosity of this South African sample to international measurements is challenging due to the varying methodologies employed in existing literature. Therefore, the demographic-specific measurements generated in this study serve to contribute to a reference database of expected arterial anatomy in a South African context.
Immunoelectron microscopic characterization of glial intermediate filaments in human gliomas
(Stellenbosch : University of Stellenbosch, 1993-03) Geiger, Dietrich Horst; Rossouw, D. J.; University of Stellenbosch. Faculty of Health Sciences. Dept. of Biomedical Sciences. Anatomy and Histology.
Glial fibrillary acidic protein (GFAP) is found in varying amounts in the cytoplasm of most normal and neoplastic cells of astroglial origin. Though not glial specific, immunoelectron microscopy has shown that vimentin and GFAP are coexpressed as monomers of glial intermediate filaments. These structures display irreversible assembly and a slow metabolic turnover. Although currently applied as astroglial markers, these intermediate filament proteins may reflect the functional and developmental differentiation status of the cells in which they are expressed. Some authors have tried to apply these aspects as diagnostic parameters for grades of malignancy and anaplasia whilst other workers have indicated variable concentrations of GFAP in different astroglial cell types and entities. Different processing protocols, including the use of epoxy and acrylic resins, omission of osmium tetroxide and variations in concentration and incubation time of primary fixatives, were evaluated to find a compromise between antigen availability and acceptable ultrastructure. Thin sections were labelled on grid for GFAP (Dako A561) and vimentin (Dako M725) by means of the indirect immunogold method. For semi- quantification of relative antigen concentrations, a novel method was devised to calculate the labelling density, percentage heterogeneity of the particle distribution and the surface area investigated. This allowed expression of labelling results as a three figure unit. Standardized post-embedding immunoelectron microscopy was performed on 11 normal and neoplastic human tissue specimens. The tissue was exposed to conventional immersion fixation in glutaraldehyde and osmium tetroxide prior to modified embedding in LR White resin. The validity of these results was verified by correlation with conventional histopathological, immunohistochemical and clinical data obtained for each specimen. The presence of epoxy resin in thin sections was shown to reduce antigen availability to such an extent that very low to negative labelling was encountered. Acrylic LR White resin allowed more acceptable immunodetection, but at the cost of inferior ultrastructure and greater instability of thin sections in the electron beam. This masked the effects of glutaraldehyde fixation on the density of the tissuefixative matrix which included destruction of the vimentin and some GFAP associated epitopes. Although osmium tetroxide was required for acceptable ultrastructure, it reduced the labelling sensitivity by 20% and was responsible for premature curing of acrylic resin during impregnation of tissue. Despite superior resolution gained by electron microscopy and the advantage of semi-quantification of labeling results, the labelling sensitivity of this technique is lesser than that of light microscopical immunohistochemistry. Immunoelectron microscopy confirmed the association between GFAP and glial intermediate filaments in almost all the glial tumours studied, correlating well with GFAP expression in matching specimens demonstrated at light microscopical level. In the absence of intermediate filaments, no positivity for GFAP or vimentin was found in oligodendroglial components of mixed tumours. GFAP positivity in astrocytomas was demonstrated by between 17 and 126 particles / µm2, whilst lower figures were obtained for the glioblastoma (PD = 8) and some of the mixed gliomas (Pd = 6). Rosenthal fibres showed both peripheral and central positive labelling for GFAP, thus providing more evidence for their hypothetical degenerative, astroglial nature. The meningioma studied, was GFAP negative, but produced low density positivity for vimentin. Coexpression of GFAP and vimentin was demonstrated in an astroblastoma and degenerative infant brain tissue, thus supporting the presence of both these proteins development of glial structures. Although sites of likely glial intermediate filament synthesis were found, the antigen availability for vimentin was too low to allow a reliable assessment of specific vimentin localization and determination of the GFAP : vimentin ratio in individual intermediate filaments and/or astroglial fibres. Variations in particle densities (PD) which demonstrated GFAP in the various astroglial entities studied, were considered to be a result of variable technical and tissue processing factors rather than truly significant differences in expression of GFAP in individual intermediate filaments. This lead to the conclusion that the GFAP concentration / glial intermediate filament area is likely to be constant for mature glial intermediate filaments and therefore cannot be used to distinguish between different astroglial cells or entities. Whether each cell has a different number of glial intermediate filaments, has not been established satisfactorily. Following complementary conventional immunohistochemistry and careful orientation of biopsy material, the procedure can be applied to suitable specimens for the electron microscopical localization of high concentrations of aldehyde resistant, cytoplasmic antigens.

Browse

Browsing Masters Degrees (Clinical Anatomy) by Title

Results Per Page

Sort Options