Anatomy and Histology

Permanent URI for this community

https://scholar.sun.ac.za/handle/10019.1/138

Browse

Now showing 1 - 20 of 20

Accurate arterial path length estimation for pulse wave velocity calculation in growing children and adolescents
(Gates Open Research, 2021-05) Witbooi, Lee-Roy C.; Page, Ben; Pitcher, Richard D.; Innes, Steve
Background: Most adult cardiovascular disease begins in childhood. Given the burgeoning obesity pandemic in children worldwide, there is a need for precise and scalable surveillance methods to detect subclinical cardiovascular disease in children and adolescents. Early detection allows early intervention and intensified primary prevention strategies in affected individuals. Carotid-femoral pulse wave velocity (PWV) directly measures arterial wall stiffness, an early feature of atherosclerosis. Calculation of PWV in growing children requires an accurate estimation of the true distance travelled by the aorto-femoral pressure wave, using surface anatomy landmarks. However, a variety of methods are used to estimate this distance, and these have not previously been investigated in growing children and adolescents. We sought to investigate this by comparing true arterial path length measured on computerized tomography (CT) scans, with a variety of estimations based on surface anatomy landmarks. Methods: Arterial path lengths were measured using multi-planar reformation (MPR) imaging software. These measurements were then compared with the surface anatomy measurements obtained using the same MPR imaging software. The fidelity of a variety of arterial path length estimation methods was tested. Results: The surface anatomy distance between the suprasternal notch and the angle of the mandible (PWV recording site in the neck), should be adjusted using the formula y=4.791+(1.0534*x). This value subtracted from the unadjusted distance from the suprasternal notch to the umbilicus, through the mid-inguinal crease to the femoral PWV recording site, provides the simplest reliable approximation of true intraluminal distance travelled. Conclusions: There is high correlation between the surface anatomy distances and the arterial path lengths they represent; however, these are not equal. Most surface anatomy measurements require adjustment using the formulae that we have provided, to accurately estimate the true distance travelled by the pulse wave.
Anti-ulcerogenic properties of Albuca setosa
(2013-12) Ndebia, E. J.; Tchokonte-Nana, Venant; Umapathy, E.; Tamadjou Tchuen, C. R.; Williams, R. P.; Sewani-Rusike, C. R.; Page, B. J.; Iputo, J. E.; Anatomy and Histology
ENGLISH ABSTRACT: Albuca setosa is a medicinal plant used by Xhosa tribe in the rural area of South Africa for the treatment of wounds, articulation problems, rheumatoid arthritis and digestive disorders. This study aimed to evaluate the healing effect of A. setosa on experimental induced gastric ulcer. The anti- ulcerogenic effects of A. setosa were investigated in male Wistar rats. Gastric ulcer was induced per os using indomethacin (50 mg/kg) and ethanol (2 ml/animal). The ulceration lesion index was calculated for each one of the ulcerated stomach; the macroscopic and histomorphology evaluation were made. In indomethacin-induced gastric ulcers, oral administration of A. setosa significantly inhibited (P<0.01) gastric ulcer formation by 82 and 83% at the dose of 100 and 200 mg/kg, respectively. In ethanol- induced gastric ulcers, A. setosa significantly inhibited (P<0.05) gastric ulcer formation by 39 and 35% at the dose of 100 and 200 mg/kg, respectively. Macroscopic evaluation of ulcerated stomachs of A. setosa treated groups showed a reduced area of gastric lesion, with moderate disruption of the gastric epithelium as well as the mucosa stromal cell. The results obtained in this study suggest that the A. setosa possesses some anti-ulcerogenic properties, which may support evidence for its traditional use.
Catecholamine release as mediator of intracellular enzyme activation in ischaemic perfused rat hearts
(Health and Medical Publishing Group (HMPG), 1975) Hough, F. S.; Gevers, W.
Isolated rat hearts perfused at suboptimal pressures have been studied as a model for generalized myocardial ischaemia. Glycogen phosphorylase a and hormone sensitive triglyceridase activities, measured as markers for endogenous catecholamine release, were significantly increased at low perfusion pressures. Pharmacological blockage of noradrenaline re uptake accentuated these effects, and depletion of catecholamine reserves eliminated them. This phenomenon may be important in the pathophysiology of cardiac ischaemia and its serious complications.
Composition of the Kirsten skeletal collection at Stellenbosch University
(Academy of Science of South Africa, 2018) Alblas, Amanda; Greyling, Linda M.; Geldenhuys, Elsje-Marie
The Kirsten Skeletal Collection is curated in the Division of Anatomy and Histology, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa. It comprises the largest documented cadaver-derived South African coloured skeletal collection in the world. Our aim in this paper is to present an inventory and characterise the identified skeletons in the Kirsten Skeletal Collection as well as provide a descriptive indication of what researchers can expect to encounter at the anthropology unit at Stellenbosch University. The skeletal material was derived mainly from the cadaver donation programme of the Division of Anatomy and Histology over a 58-year period (1957–2015). All pertinent information for each individual skeleton is entered into a database and a full skeletal inventory is established. The skeletal database registry was analysed to demonstrate the distribution of age, sex and population affinity of individuals in the collection. Currently, this collection consists of 1161 skeletons with known records. Despite differences in the age and sex composition, the skeletal profile in general reflects mainly the profile of the Western Cape population. Most individuals were born between 1920 and 1950, placing the Kirsten Skeletal Collection in the early to mid-20th century. The age at death for the greatest proportion (41.8%) of individuals was between 40 and 60 years. Current biological profile techniques in age, ancestry and sex estimation can be improved and, among others, new regional and ancestral specific standards for the biologically unique and diverse South African coloured population can be developed.
Congenital Anomalies of the Tracheobronchial Tree: A Meta-Analysis and Clinical Considerations
(2020-11) Wong, Linda M; Cheruiyot, Isaac; Santos de Oliveira, Maria Helena
Background The aim of this study was to determine the prevalence and anatomical features of major tracheobronchial anomalies (mTBAs). Methods Major electronic databases were systematically searched to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcome was the prevalence of mTBAs, specifically tracheal bronchus (TB) and accessory cardiac bronchus (ACB). Secondary outcomes included the origin and types of TB and ACB. Results A total of 27 studies (n=119,695 patients) were included. A TB was present in 0.99% (95% CI 0.67-1.37) of patients, while an ACB was present in 0.14% (95% CI 0.09- 0.20). The overall prevalence of TB was higher in imaging than in operative studies (1.81% vs 0.82%). It was also higher in pediatric (2.55%) than in adult studies (0.50%). Patients with other congenital anomalies were 15 times more likely to have a TB (OR=14.89; 95% CI 7.09-31.22). The most common origin of TBs was from the trachea (81.42%), primarily from the right side (96.43%). The most common origin of ACBs was from the intermediate bronchus (74.32%). ACBs terminated as blind-ending diverticulum in two-thirds of cases. Conclusions mTBAs are present in approximately 1% of the population, although the prevalence is higher in pediatric patients and those with accompanying congenital anomalies. Although rare, mTBAs can be associated with significant respiratory morbidities, and present challenges during airway management in surgical and critical care patients. Establishing a pre-operative diagnosis of these variations is essential for planning and implementing an appropriate airway management strategy to minimize attendant complications.
Die effek van steroied-terapie op die sitologiese en histopatologiese veranderinge tydens eksperimentele ekstrinsieke allergiese alveolitis (hipersensitiwiteitspneumonitis)
(Health & Medical Publishing Group, 1981) Rossouw, D. J.; Chase, C. C.; Scheepers, J. C. E.
Acute extrinsic allergic alveolitis was experimentally induced in rabbits using horseradish peroxidase (HRP) as antigen. Bronchoalveolar lavage was performed on the excised lungs and total and differential cellular yields determined, and correlated with the histopathological changes in the lungs as well as the total and differential white blood cell counts. After a single parenteral immunization with HRP without adjuvants, and weekly aerosol challenges with nebulized HRP solution for 3 consecutive weeks, a 3-fold increase in the total cell count as well as very pronounced rise in the percentage of lymphocytes was noticed. Histopathologically, the bronchi-associated lymphoid tissue dw-3 (BALT) became more prominent, an increase in the number of foreign body giant cells was noticed and a focal interstitial and intra-alveolar accumulation of lymphocytes, granulocytes and macrophages could be demonstrated, as well as a mild hyperplasia of type 2 alveolar epithelial cells. Intramuscular injections of methylprednisolone acetate (Depo-Medrol) every 72 hours induced a pronounced peripheral lymphopenia, thymic involution and an almost complete disappearance of the BALT in both the control and HRP-challenged rabbits. Similarly, a marked decrease in the total cell count and percentage of lymphocytes was noticed in the broncho-alveolar fluid of the animals with hypersensitivity pneumonitis. No signs of interstitial or intra-alveolar reactions were seen in the lungs of the experimental animals after 3 weeks of aerosol antigen challenge when treated with steroids. Collectively, these data suggest that the development of hypersensitivity pneumonitis was, at least in part, due to a cell-mediated immunological reaction in the lung. This animal model in which steroid suppression of experimental allergic alveolitis has been demonstrated, may be employed to elucidate the cellular pathogenesis of this disease process.
Efficiency of co-expression of transcription factors Pdx1, Ngn3, NeuroD and Pax6 with insulin : a statistical approach
(Elsevier, 2015-05) Du Toit, Don F., 1946-; Longo-Mbenza, Benjamin; Page, Benedict J.; Tchokonte-Nana, Venant; Stellenbosch University. Dept. of Biomedical Sciences, Division of Anatomy and Histology
Aim: The objective of this study was to investigate the time related profile and efficiency of co-expression of the homeodomain proteins Pdx1, NeuroD, Ngn3, Pax6 and caspase3 with insulin, and to establish the time periods post PDL optimum for islets transplantation. Study design/methods: In this experimental study, immunofluorescent staining procedure was performed on deparaffinized pancreatic duct ligated (PDL) tissues of 78 Sprague–Dawley rats. Quantification of protein coexpression was made using a computerized morphometry. The efficiency of co-expression was arbitrary defined by the value of mean ratio (score without unit) of insulin expression divided by each expression index of the other proteins, occurring within the time interval of 12–24 h post PDL. Statistical tool was used to analyze the efficiency of co-expression of proteins; analysis of variances (one way ANOVA) was used to compare the means of co-expression indexes across the time periods pre- and post PDL. P-values less than 0.05 were considered statistically significant; no post hoc test was done.
Endovascular aortic aneurysm repair by a multidisciplinary team : lessons learned and six-year clinical update
(Clinics cardiv Publishing, 2005-02) Du Toit, D. F.; Saaiman, J. A.; Carpenter, J. P.; Geldenhuys, K. M.
Background: Endovascular aneurysm repair (EVAR) (using an Federal Drug Association-approved AneuRx® device) compared to conventional surgical repair of abdom inal aortic aneurysm (AAA) previously rendered favourable outcomes regarding post-operative pain, avoidence of laparotomy, and rapid rehabilitation and hospital discharge in high-risk patients, including octagenarians. Objectives: To assess the safety, reduction in aneurysmrelated deaths, and interim survival data up to 72 months after AAA exclusion by endoluminal endografts (EVAR). Design: We carried out an open, controlled, prospective, multidisciplinary EVAR study for the period 1998 to 2003 (six years). In the earlier part of the study, EVAR was compared with previously published results of conventional open aneurysmectomy surgery. Setting: Heart Unit, Panorama Medi-Clinic, Parow, South Africa. Participants: We recruited adult male and female patients presenting with AAA and fulfilling the inclusion criteria for endovascular repair, as recommended by the consensus 2003 meeting of the Vascular Association of South Africa (VASSA). All patients were offered open surgery as an alternative and were entered into the VASSA EVAR trial registry. Pre-operatively, AAA anatomy was assessed by spiral-computed tomography (CT), and selectively with conventional angiography and intravascular ultrasound (IVUS). Informed consent was obtained in accordance with the recommendations of the Senate of Surgery Paper 2, Ethical Guidelines, Great Britain and Ireland. Patients underwent EVAR by a multidisciplinary interventional team. Interventions: Two hundred and seven adult patients with AAA were assessed. Forty-four of the 207 (21.2%) were excluded from EVAR because of irreversible comorbid factors and complex aneurysm morphology. One hundred and sixty-three patients (78%), with a mean age of 70.7 years (range 60−91 years), underwent EVAR (1998−2003). Five patients were lost to follow-up (3%). Median AAA diameter was 56.9 mm and ASA ratings were I, 1.2%; II, 15.9%; III, 57%; IV, 22.6%; and V, 2.4%. EVAR was performed in high- and low-risk categories of both sexes. Most patients were in ASA groups III and IV. Devices deployed: EVAR was performed using a selection of endografts over 72 months − AneuRx® (Medtronic) 47; Talent® (Medtronic) 49; Vanguard® three; Zenith® (Cook) one; Powerlink® (Endologix) 62; and other, one. Results: Thirty-day outcome: successful deployment 99%, primary stent patency 97%, surgical conversion 0.6%, procedural or intra-operative mortality 1.2%, 30-day mortality 4.3%, endoleaks 1.84%, and secondary intraprocedural endovascular interventions 24.5%. Perioperative mortality was 3.1% (one aneurysm related). One patient had suspected endograft infection. Late mortality was 21.4% (35 patients due to co-morbidities, and one was aneurysm related). Follow-up was a median of 28.3 months (range 1−69 months). In 163 patients, two persisting endoleaks (1.2%) were detected. Endotension was detected in 3/163 (1.8%) with average sac increase of 0.8 cm. Conversion to open surgery was needed in one patient (0.6%). Co-morbidities that contributed to late mortality included multi-organ failure, ischaemic heart disease (IHD), cardiomyopathy, renal failure, stroke and cancer. One procedural rupture was fatal (0.6%). Two late ruptures occurred; one was successfully endostented and the other patient died after a failed surgical intervention (0.6%). Endovascular repair of AAA is more expensive than conventional surgery. Introduction of the Endologix stent has reduced operative time from 120 to 60 minutes in un complicated patients. Newer-generation aortic stents allow better control of negative remodeling and stent migration. Conclusion: A multidisciplinary team can safely perform EVAR, with a low 30-day mortality rate in selected patients graded ASA II−IV and with favourable aortic aneurysm morphology. About 22% of patients with AAA are not suited for EVAR. Persisting late endoleaks occurred in 1.2% of the cohort study and were not device specific. Life-long follow-up post EVAR is a prerequisite to detect late device failure, endoleaks and aneurysm-sac enlargement, and to assure the durability of these midterm results. Short-term aneurysm rupture prevention is a predictable outcome in high-risk groups.
Ethics, litigation and teaching of anatomy
(Health & Medical Publishing Group, 2003) Du Toit, D. F.
Curriculum time devoted to teaching human gross anatomy in medical and dental schools has diminished to accommodate new knowledge and other disciplines. Systembased curricula have replaced classic anatomy teaching on a regional basis. ‘Wet labs’ have disappeared and the electronic media has taken the place of the anatomist.
EVAR : critical applied aortic morphology relevant to type-II endoleaks following device enhancement in patients with abdominal aortic aneurysms
(Clinics Cardiv Publishing, 2004-08) Du Toit, D. F.; Saaiman, J. A.; Labuschagne, B. C. J.; Vorster, W.; Van Beek, F. J.; Boden, B. H.; Geldenhuys, K. M.
Endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is an established alternative option to conventional surgery for AAA, provided optimal anatomical morphology of the aneurysm sac, neck and outflow exists. In most documented series of EVAR, type-II endoleak occurrence is a universal procedural drawback. This is referred to as the Achilles heel of EVAR. This morphological study, addressing predominantly non-aneurysmal aortic anatomy, reveals the dyssynchronous origins of the renal ostia, ectopia of the superior mesenteric artery and median sacral artery, variations in the length of the infrarenal abdominal aorta, multiple mainstem renal arteries, and the presence of accessory renal arteries (in 13% of cadavers). Such potential vascular anomalies need careful consideration pre-operatively prior to EVAR. In a prospective, clinical study of EVAR in 163 patients over 60 months, using four different aortic stent devices, we demonstrated an intraprocedural type-II endoleak rate, before exclusion, of 3% (5/163). Most were related to patent lumbar arteries. An active policy of intraprocedural aneurysm pressure sac measurement and angiography was used to demonstrate type-I and type-II endoleaks, focusing on the applied anatomy of aortic side branches and variations. Selective intraprocedural coil embolisation and thrombin injection into the sac was utilised to thrombose persisting and large lumbar arteries that predisposed to retroleaks. We recorded a low incidence of persisting type-II endoleaks using this proactive treatment strategy by addressing variant aortic morphology and patent lumbar arteries during EVAR. One aneurysm-related death (0.6%) was observed due to late rupture after EVAR, and a single intraprocedural death was related to unpredictable aneurysm rupture. In conclusion, comprehensive anatomical knowledge of the abdominal aorta and its main collateral side branches, including variations, is a fundamental prerequisite if satisfactory and predictable results are to be achieved after EVAR, especially regarding prevention, diagnosis and treatment of type-II endoleaks. Intraprocedural aneurysm sac pressure monitoring, coil embolisation and the use of injection of thrombin into the aneurysm sac of selected patients is useful in reducing the incidence of post-EVAR type-II persisting endoleaks.
Histomorphometric and radioimmunoassay studies of the rat endometrium following peanut oil treatment
(Research and Clinical Center for Infertility, Shahid sadoughi University of Medical Sciences of Yazd, 2011-02) Tchokonte-Nana, Venant; Longo-Mbenza, Benjamin
Background: The pregnancy rate during in-vitro fertilization (IVF) following progesterone supplement still remains very low at around 20%. Objective: To investigate the effects of peanut oil itself on the endometrial receptivity, the pregnancy success rate and fertility during the peri-implantation time in hyper stimulated and normal rats. Materials and Methods: Thirty-six adult Sprague Dawley rats with at least four regular oestrus cycles were randomly divided into 4 groups: two groups were hyper stimulated by human chorionic gonadotropin (hCG) and treated with progesterone or with peanut oil; the two other groups were not hyper stimulated and treated with saline solution or peanut oil. On day 5.5 of pregnancy, the uterine horns were removed and blood was collected for histomorphometric and serum progesterone evaluation. 12 rats were allowed to continue the presumed pregnancy to term. Analysis of variance (ANOVA) and student t-test were used to compare the means of morphometric and radioimmunoassay data between groups. p-values less than 0.05 were considered statistically significant. Results: The mean values of morphometric parameters and serum progesterone varied significantly between the groups (ANOVA, p<0.0001). The lowest values of progesterone parameters were observed in the hyperstimulated groups that did not deliver pups; both hyperstimulated groups had deleterious luminal epithelium with varying degrees of mucosal projections. There were isolated decidualised zones observed in hyper stimulated peanut oil group, whereas peanut oil group had the highest number of implantation sites and deliveries. Conclusion: The results show that hype stimulation reduces the endometrial receptivity, while peanut oil increases endometrial receptivity, pregnancy rates and fertility by triggering decidualisation.
Immunohistomorphology of pancreatic islet microvasculature and the immunophenotypic analysis of CEPC in adult diabetic rats
(Sociedad Chilena de Anatomia, 2017) Tchokonte-Nana, Venant; Le Roux, Danie Jacobus; Kotze, Patricia Clara; Ngounou, Eleonore
ENGLISH ABSTRACT: Hyperglycaemia is one of the main causes for the endothelial cell (EC) damage in diabetic patients. Even though circulating endothelial progenitor cells (CEPC) could be used as a prognosis for microvascular complications, there is very little information on the islet microvasculature. We analysed by immunohistochemistry and by flow cytometric immunophenotyping, the expression of CD34 on EC and the expressions of CD31, CD34, CD45 and CD133 on CEPC in Streptozotocin (STZ)-induced diabetic rats. Peripheral blood and tissue specimens were obtained from rats of different treatment regimens: STZ treatment, control saline (NS) and sodium citrate (CB) treatments. Blood cells were exposed to flow cytometric immunophenotyping for CD133, CD31, CD34, CD45 and CD133. While tissues from the pancreas, liver and kidney were routinely processed and stained immunohistochemically for CD34. There was a tendency of an increased in CD45-/CD133+/CD31+/CD34+ cells (0.04 ± 0.11 %) in diabetic rats compared to the controls (CB: 0.03 ± 0.04 %; Saline: 0.01 ± 0.03 %). But there was no significant statistical difference between them. The expression pattern of CD34 on the EC in the organs’ vascular beds including arterioles, venules, capillaries and sinusoids was extremely heterogeneous across and within treatment regimens. The ECs in the sinusoids of the liver presented similar CD34 expression patterns across different treatment regimens, while the expression of CD34 on the ECs of sinusoidal capillaries in the pancreas vary with the treatment regimen. We conclude that the degree of endothelial cell damage is not uniform across organs’ vascular beds in the rat, contrary to mice and humans. Furthermore, the sinusoids in the pancreas and the kidney may have the same degree of endothelial damage when exposed to the same deleterious causes.
The inferior intercavernous sinus : an anatomical study with application to trans-sphenoidal approaches to the pituitary gland
(Elsevier, 2020-06) Wahl, Lauren; Lockwood, Joseph D.; Keet, Kerri; Henry, Brandon Michael; Gielecki, Jerzy; Iwanaga, Joe; Bui, C. J.; Dumont, Aaron S.; Tubbs, R. Shane
Objectives: The inferior intercavernous sinus is located below the pituitary gland in the sella turcica. Its presence has been controversial among anatomists because it is not always found on radiological imaging or during cadaveric dissections; however, it is becoming a better-known structure in the neurosurgical and radiological fields, specifically with respect to transsphenoidal surgery. Therefore, the present study was performed to better elucidate this structure at the skull base. Patients and methods: Fifty adult, latex injected cadavers underwent dissection. The presence or absence of the inferior cavernous sinus was evaluated and when present, measurements of its width and length were made. Its connections with other intradural venous sinuses were also documented. Results: An inferior intercavernous sinus was identified in 26 % of specimens. In all specimens, it communicated with the left and right cavernous sinus. The average width and length were 3 mm and 9.5 mm, respectively. In the sagittal plane, the inferior intercavernous sinus was positioned anteriorly in 31 %, at the nadir of the sella turcica in 38 %, and slightly posterior to the nadir of the sella turcica in 31 %. In two specimens (15.4 %), the sinus was plexiform in its shape. In one specimen a diploic vein connected the basilar venous plexus to the inferior intercavernous sinus on its deep surface. Conclusion: An improved understanding of the variable anatomy of the inferior intercavernous sinus is important in pathological, surgical, and radiological cases.
Morphogenetic and clinical perspectives on the neogenesis of pancreatic duct ligation-induced islet cells : a review
(Official Organ of Wroclaw University of Medicine, 2011) Tchokonte-Nana, Venant; Longo-Mbenza, Benjamin; Page, Benedict J.; Du Toit, Donald F.
This review focuses on recent progress in understanding morphogenetic findings on the neogenesis of islet beta cells following Pancreatic Duct Ligation (PDL) in animal models. These results may give hope for modifications in the treatment of diabetes in general and transplantation in particular. On the basis of this review, translational studies should be developed to allow information on beta-cell neogenesis to be integrated into a potential therapy for Diabetes Mellitus (DM) in humans. Further studies on the development of animal models that will produce PDL islets for transplantation are urgently needed.
Opening the floor for discussion : a perspective on how scholars perceive attitudes to science in policymaking in South Africa
(ASSAf, 2021-01-29) Czachur, Molly V.; Todd, Melvi; Goncalves Loureiro, Taina; Azam, James M.; Nyeleka, Siphokazi; Alblas, Amanda; Davies, Sarah J.
Policymakers are a vital group with whom scientific research should be communicated, especially when the reason for many research projects is linked to relevance for socio-political and economic management. Science communication has a vital role in transforming research into policy, and a core element of this process is understanding the target group, namely policymakers. Science and policy influence each other deeply, so researchers and policymakers should improve their understanding of each other and of the processes involved in both fields in order to better collaborate. Accordingly, an in-depth understanding of how scholars perceive policymakers is a precondition for scientists to achieve any desired management and policy impacts. In December 2019, six researchers and one research manager from Stellenbosch University, South Africa, gathered to discuss their understanding of policymakers. The discussion was part of a Science Communication Masterclass hosted by the South African Research Chair in Science Communication and Econnect Communication, Australia. The purpose of the group discussion was to develop a science communication strategy that would enhance the sharing of scientific research outputs with policymakers in South Africa. We explored five questions to help us record our perception of policymakers: (1) Who do we think the policymakers are? (2) How do we think that policymakers perceive research? (3) What concerns do we believe that policymakers have about research? (4) What information do we think policymakers are interested in? (5) What forms of communication do we think policymakers prefer? This Commentary presents our view on how we think researchers perceive policymakers, as discussed in the Science Communication Masterclass. We hope to initiate a discussion around science communication with policymakers, and improve current practices.
Population structure of mixed Mycobacterium tuberculosis infection is strain genotype and culture medium dependent
(Public Library of Science, 2013-07-30) Hanekom, Madeleine; Streicher, Elizabeth M.; Van de Berg, Doreen; Cox, Helen; McDermid, Cheryl; Bosman, Marlein; Gey van Pittius, Nicolaas C.; Victor, Tommie C.; Kidd, Martin; Van Soolingen, Dick; Van Helden, Paul D.; Warren, Robin M.
Background Molecular genotyping methods have shown infection with more than one Mycobacterium tuberculosis strain genotype in a single sputum culture, indicating mixed infection. Aim This study aimed to develop a PCR-based genotyping tool to determine the population structure of M. tuberculosis strain genotypes in primary Mycobacterial Growth Indicator Tubes (MGIT) and Löwenstein–Jensen (LJ) cultures to identify mixed infections and to establish whether the growth media influenced the recovery of certain strain genotypes. Method A convenience sample of 206 paired MGIT and LJ M. tuberculosis cultures from pulmonary tuberculosis patients resident in Khayelitsha, South Africa were genotyped using an in-house PCR-based method to detect defined M. tuberculosis strain genotypes. Results The sensitivity and specificity of the PCR-based method for detecting Beijing, Haarlem, S-family, and LAM genotypes was 100%, and 75% and 50% for detecting the Low Copy Clade, respectively. Thirty-one (15%) of the 206 cases showed the presence of more than one M. tuberculosis strain genotype. Strains of the Beijing and Haarlem genotypes were significantly more associated with a mixed infection (on both media) when compared to infections with a single strain (Beijing MGIT p = 0.02; LJ, p<0.01) and (Haarlem: MGIT p<0.01; LJ, p = 0.01). Strains with the Beijing genotype were less likely to be with “other genotype” strains (p<0.01) while LAM, Haarlem, S-family and LCC occurred independently with the Beijing genotype. Conclusion The PCR-based method was able to identify mixed infection in at least 15% of the cases. LJ media was more sensitive in detecting mixed infections than MGIT media, implying that the growth characteristics of M. tuberculosis on different media may influence our ability to detect mixed infections. The Beijing and Haarlem genotypes were more likely to occur in a mixed infection than any of the other genotypes tested suggesting pathogen-pathogen compatibility.
Prevalence and trends of staphylococcus aureus bacteraemia in hospitalized patients in South Africa, 2010 to 2012 : laboratory- based surveillance mapping of antimicrobial resistance and molecular epidemiology
(Public Library of Science, 2015-12) Perovic, Olga; Iyaloo, Samantha; Kularatne, Ranmini; Lowman, Warren; Bosman, Noma; Wadula, Jeannette; Seetharam, Sharona; Duse, Adriano; Mbelle, Nontombi; Bamford, Colleen; Dawood, Halima; Mahabeer, Yesholata; Bhola, Prathna; Abrahams, Shareef; Singh-Moodley, Ashika
Introduction: We aimed to obtain an in-depth understanding on recent antimicrobial resistance trends and molecular epidemiology trends of S. aureus bacteraemia (SAB). Methods: Thirteen academic centres in South Africa were included from June 2010 until July 2012. S. aureus susceptibility testing was performed on the MicroScan Walkaway. Real-time PCR using the LightCycler 480 II was done for mecA and nuc. SCCmec and spa-typing were finalized with conventional PCR. We selected one isolate per common spa type per province for multilocus sequence typing (MLST). Results: S. aureus from 2709 patients were included, and 1231 (46%) were resistant to methicillin, with a significant decline over the three-year period (p-value = 0.003). Geographical distribution of MRSA was significantly higher in Gauteng compared to the other provinces (P<0.001). Children <5 years were significantly associated with MRSA with higher rates compared to all other age groups (P = 0.01). The most prevalent SCCmec type was SCCmec type III (531 [41%]) followed by type IV (402 [31%]). Spa-typing discovered 47 different spa-types. The five (87%) most common spa-types were t037, t1257, t045, t064 and t012. Based on MLST, the commonest was ST612 clonal complex (CC8) (n = 7) followed by ST5 (CC5) (n = 4), ST36 (CC30) (n = 4) and ST239 (CC8) (n = 3). Conclusions: MRSA rate is high in South Africa. Majority of the isolates were classified as SCCmec type III (41%) and type IV (31%), which are typically associated with hospital and community- acquired infections, respectively. Overall, this study reveals the presence of a variety of hospital-acquired MRSA clones in South Africa dominance of few clones, spa 037 and 1257. Monitoring trends in resistance and molecular typing is recommended to detect changing epidemiological trends in AMR patterns of SAB.
Shoulder surgeon and autologous cellular regeneration - from bench to bed: part one - the link between die human fibroblast, connective tissue disorder and shoulder.
(MedKnow Publications, 2007-09) Du Toit, Don F.; Kleintjes, Wayne G.; Mazyala, Erick J.; Bhatia, Deepak N.; De Beer, Joe F.; Page, Benedict J.
The process of autologous cell regeneration (ACR) is a facet of cell therapy and regenerative medicine. It is initiated when activated autologous platelet rich plasma alone (PRP), containing cytokines or growth factors, is injected into the dermis or other structure in order to initiate a regenerative or antiaging process. The recipients resident cells at the target zone are activated by biologically active growth factors, derived from the activated platelets in the PRP through a paracrine effect. The platelet gel that contains the fibrin and clumped platelets, releases growth factors that influences activation of macrophages and stem cells in the recipient site. Tissue regeneration is facilitated by stem cell proliferation and differentiation. The PRP that has sealant and wound healing properties, may shift the wound healing cascade to the left, thereby speeding up tissue regeneration and remodelling by the use of the recipients own plasma. Both the fibroblast and myofibroblast play key roles in the wound healing cascade. The fibroblast, of mesenchymal origin, plays a pivotal role in the formation of the extracellular matrix and deposition of collagen. A failure of organised fibroblast function results in important and disabling disease processes and conditions such as chronic ischaemic heart disease and remodelling of the heart, lung fibrosis, fibromatosis, solar aged-face, keloids, hypertrophic scar formation, nodular fasciitis, inguinal hernia, Dupuytren's disease and scleroderma. More recent additions include frozen shoulder and the captured shoulder. In aesthetic medicine, one of the prime functions of fractional photothermolysis with lasers, intense pulsed light and radiofrequency devices, is to stimulate dermal fibroblast proliferation, by thermal energy thereby increasing collagen deposition which enhances facial rejuvenation. Platelet -rich plasma (REGENLAB PRP, REGENLAB-ACR) possesses unique growth factors that stimulate, fibroblast, keratinocyte and myoblasts ex vivo in tissue culture, allowing three-dimensional cell proliferation within the fibrin gel. PRP can be used as a cell carrier (i.e., keratinocytes, fibroblasts), may enhance cell retention at the point of treatment. REGENKIT is authorized for human use, ISO and CE marked. In this overview fibroblast morphology, tissue culture and cell biology relevant to the shoulder surgeon is reviewed.
Sperm structure and motility in the eusocial naked mole-rat, Heterocephalus glaber : a case of degenerative orthogenesis in the absence of sperm competition?
(BioMed Central, 2011-12) Van Der Horst, Gerhard; Maree, Liana; Kotze, Sanet H.; O Riain, M. Justin
ABSTRACT: Background We have studied sperm structure and motility in a eusocial rodent where reproduction is typically restricted to a single male and behaviourally dominant queen. Males rarely compete for access to the queen during her estrus cycle, suggesting little or no role for sperm competition. Results Our results revealed an atypical mammalian sperm structure with spermatozoa from breeding, subordinate and disperser males being degenerate and almost completely lacking a "mammalian phylogenetic stamp". Sperm structure is characterized by extreme polymorphism with most spermatozoa classified as abnormal. Sperm head shapes include round, oval, elongated, lobed, asymmetrical and amorphous. At the ultrastructural level, the sperm head contains condensed to granular chromatin with large open spaces between the chromatin. Nuclear chromatin seems disorganized since chromatin condensation is irregular and extremely inconsistent. The acrosome forms a cap (ca 35%) over the anterior part of the head. A well defined nuclear fossa and neck with five minor sets of banded protein structures are present. The midpiece is poorly organized and contains only 5 to 7 round to oval mitochondria. The flagellar pattern is 9+9+2. A distinct degenerative feature of the tail principal piece is the absence of the fibrous sheath. Only 7% motile spermatozoa were observed which had exceptionally slow swimming speeds. Conclusion In this species, sperm form has simplified and degenerated in many aspects and represents a specialised form of degenerative orthogenesis at the cellular level.
Trace element concentration changes in brain tumors : a review
(American Association for Anatomy, 2020-05) Cilliers, Karen; Muller, Christo J. F.; Page, Benedict J.
Trace elements have been implicated in cancer, since the levels differ between cancerous and noncancerous tissue, different cancer types, and different malignancy grades. However, few studies have been conducted on trace element concentrations in brain tumors. Thus, this study aims to review the available literature on trace element changes related to brain tumors, and to identify gaps in the literature. A literature search was done on Google Scholar and PubMed from their start date to January 2018, using terms related to trace element concentration and brain tumors. All brain tumor types were included, and articles could be published in any year. From this search, only 11 articles on this topic could be found. Tumors had significantly higher concentrations of arsenic, thorium, lanthanum, lutetium, cerium, and gadolinium compared to control brain samples. Compared to adjacent tissue, tumor tissue indicated increased magnesium, decreased copper, and contradicting results for zinc. Furthermore, the higher the malignancy grade, the lower the calcium, cadmium, iron, phosphorus and sulfur concentration, and the higher the mercury, manganese, lead, and zinc concentrations. In conclusion, altered trace element levels differ amongst different tumor types, as well as malignancy grades. Consequently, it is impossible to compare data from these studies, and available data are still considerably inconclusive. Ideally, future studies should have a sufficient samples size, compare different tumor types, and compare tumors with adjacent healthy tissue as well as with samples from unaffected matched brains. Anat Rec, 303:1293-1299, 2020. © 2019 American Association for Anatomy.

Browse

Browsing Anatomy and Histology by browse.metadata.type "Article"

Results Per Page

Sort Options