Morphology of the palmaris longus and plantaris muscles employed as flaps in reconstructive surgery

Tendons are frequently used for reconstructive surgery. This includes palmaris longus, plantaris, the long extensors of the toes and fingers as well as the flexors of the fingers. The surgeon must base his or her selection of the donor tendon for grafting on what is needed, for example tendon size, length, and width. The most desirable tendons in reconstructive surgery are the palmaris longus and plantaris tendons. These two muscles are also considered to be the easiest tendons to harvest, and therefore they remain the ideal choices for plantaris,or tendon grafts. Apart from what is mentioned in the literature, questions remain such as: which characteristics do the palmaris longus and plantaris muscles possess that make them suitable for use as flaps or grafts in reconstructive surgery and; how can knowledge of the characteristics of these muscles improve reconstructive surgery in South Africa? The palmaris longus and plantaris muscles are indeed subject to variation, whether in the general anatomy, form, attachment, actions and/or prevalence. A statistical significant difference was found between the male and female sample when considering the length of the palmaris longus muscle. When comparing the palmaris longus muscle to the plantaris muscles, it was found that there is a statistical significant difference between them as well. Therefore, although these muscles may look alike, when it comes to the surgical aspect it is suggested that the palmaris longus is used when a wider tendon is preferred and the plantaris muscle when a longer tendon is needed. The prevalence of the palmaris longus and plantaris muscles compared well with studies done on other population groups. No correlation was found between the sex of the cadaver and the prevalence of the palmaris longus and plantaris muscles. In addition it was established that there is no relationship between the prevalence of the palmaris longus and plantaris muscles in the same individual. A possible phylogenetic degenerative trend for the palmaris longus muscle was also examined. After studying various age groups, it was determined that such a trend could not be established for this sample. In conclusion, based on the morphology and prevalence of the palmaris longus and plantaris muscles in a South African population, they are ideal for the use of flaps and/or tendon graft in reconstructive surgery. But it is of utmost importance that the reconstructive surgeon, working on South African patients, remember that both these muscles are subject to variation and not only will it be beneficial to employ proper detection methods to determine the viability of either muscle before considering its suitability in reconstructive surgery but also a sound knowledge of the anatomy of these muscles must be known. AFRIKAANS : Tendons word dikwels gebruik vir rekonstruktiewe chirurgie. Dit sluit die M. palmaris longus en M. plantaris, die lang ekstensors van die tone en vingers, sowel as die fleksors van die vingers in. Die chirurg moet sy of haar keuse van die skenkertendon baseer op dit wat benodig word, byvoorbeeld tendongrootte, ~lengte en ~breedte. Die mees gesogte tendons in rekonstruktiewe chirurgie is dié van M. palmaris longus en M. plantaris. Hierdie twee spiere word ook geag as die maklikste spiere om te oes / bekom, en daarom bly hulle die ideale keuse vir weefselsnitte of tendon-oorplantings. Afgesien van wat in die literatuur beskryf word, bly die volgende vrae onbeantwoord: Watter eienskappe maak M. palmaris longus en M. plantaris geskik vir die gebruik as weefselsnitte of tendon-oorplantings in rekonstruktiewe chirurgie en, hoe kan kennis van hierdie eienskappe van dié spiere, rekonstruktiewe chirurgie in Suid-Afrika verbeter? M. palmaris longus en M. plantaris is inderdaad onderworpe aan variasie van die algemene anatomie, vorm, aanhegtings, aksies en / of aanwesigheid en/of afwesigheid. 'n Statistiese beduidende verskil is gevind tussen die manlike en vroulike steekproef ten opsigte van die lengte van M. palmaris longus. M. palmaris longus is met M. plantaris ook vergelyk en daar was gevind dat daar 'n statisties beduidende verskil tussen hierdie spiere is. Alhoewel hierdie spiere dieselfde lyk, is dit belangrik om in ag te neem dat as dit by die chirurgiese aspekte kom, word daar voorgestel dat M. palmaris longus eerder gebruik moet word wanneer 'n wyer tendon verkies word en M. plantaris gekies moet word wanneer ‘n langer tendon benodig word. Daar is goeie ooreenkoms tussen die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris wanneer hul met studies, wat op die ander bevolkingsgroepe gedoen was, vergelyk word. Geen ooreenkomste was tussen die geslag van die kadawer en die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris gevind nie. Daarbenewens was dit vasgestel dat daar geen verhouding tussen die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris in dieselfde individu is nie. 'n Moontlike filogenetiese degeneratiewe tendens vir M. palmaris longus is ook ondersoek. Na die bestudering van verskillende ouderdomsgroepe, is daar bepaal dat so 'n tendens nie bevestig kon word vir hierdie steekproef nie. Ter afsluiting, die morfologie en die aanwesigheid en/of afwesigheid van M. palmaris longus en M. plantaris, in 'n Suid-Afrikaanse bevolking, is ideaal vir die gebruik van weefselsnitte of tendon-oorplantings in rekonstruktiewe chirurgie. Maar dit is van uiterste belang dat die rekonstruktiewe chirurg, wie met Suid-Afrikaanse pasiënte werk, onthou dat beide hierdie spiere onderworpe is aan variasie. Dit sal dus voordelig wees om behoorlike opsporingsmetodes te gebruik om die vatbaarheid van hierdie spiere in rekonstruktiewe chirurgie vas te stel, maar hy of sy het ook kennis van die anatomie van hierdie spiere, nodig. CopyrightDissertation (MSc)--University of Pretoria, 2011.Anatomyunrestricte

Surface preparation and the effects on rock art deterioration

The Drakensberg is the highest part of a 1000-km long escarpment that also forms a natural border between South Africa and eastern Lesotho. The uKhahlamba-Drakensberg Park was declared a World Heritage site in 2000 and is globally significant, in particular due to the rock art painted by San hunter-gatherers who inhabited the area from about 8 000 years ago until the late 19th Century. Approximately 30 000 painted images can be found in nearly 600 rock shelters in the area. Rock art heritage in the Drakensberg is unfortunately being lost through a variety of processes, some natural and others resulting from human impacts. Previous research on the weathering of San paintings has focused largely on either monitoring processes causing weathering in rock shelters or investigating rock surfaces that are adjacent to the rock paintings. Recent findings indicate that some of the San art has been painted onto surfaces that were prepared by smoothing the rock surface with a “grinding stone” and coated with a clay (“ground”) layer prior to the application of pigments. This new information may have important implications for rock art conservation as smoothing of a rock surface could significantly modify the physical and chemical characteristics of the surface, thereby influencing the deterioration of the art. In this study two classification systems are developed from data collected in four rock shelters situated in the Park. The first, a Type of Surface Classification System, is developed for the purpose of identifying different types of rock surfaces within rock shelters. The second, a State of Deterioration Classification System, is developed with the purpose of establishing, through visual inspection, how deteriorated the rock art on different types of rock surfaces is. Linkages between the type of surface and the state of deterioration are also explored. Findings show that it is not only possible to determine which surface type a painting has been painted on, but that different rock surface types can deteriorate through different weathering mechanisms and to a different degree. One type of rock surface, acknowledged but not yet recorded, was found amongst the rock art paintings selected for the purpose of this study. More importantly, the alteration of rock surfaces through human action in the past is found to cause rock surfaces to deteriorate either at an accelerated or a retarded rate as opposed to rock paintings that were made on surfaces that have only been altered by natural weathering mechanisms. For example, if a rock surface has only been smoothed with a grinding stone, results show that weathering mechanisms did not deteriorate the surface as quickly as in the case where a clay ground layer has been applied to the rock surface. Different types of rock surfaces deteriorating through different weathering mechanisms (as a result of surface preparation) might have significant implications in terms of rock art conservation as the strategies implemented to conserve rock art should be adapted to consider surface type. In terms of rock art studies aiming to conserve this precious heritage, the two classification systems presented could, therefore, be useful non-destructive tools in assessing rock art deterioration. CopyrightDissertation (MA)--University of Pretoria, 2011.Geography, Geoinformatics and MeteorologyMAUnrestricte

An anatomical investigation of the suboccipital- and inferior suboccipital triangles

The suboccipital triangle (ST) is a clinically relevant landmark in the posterior aspect of the neck and is used to locate and mobilize the horizontal segment of the third part of the vertebral artery before it enters the cranium. Unfortunately, this space is not always a viable option for vertebral artery exposition, and consequently a novel triangle, the inferior suboccipital triangle (IST) has been defined. This alternative triangle will allow surgeons to locate the artery more proximally, where its course is more predictable. The purpose of this study was to better define the anatomy of both triangles by measuring their borders and calculating their areas. Ethical clearance was obtained from the University of Pretoria (reference number: 222/2021) and both triangles were subsequently dissected out on both the left and right sides of 33 formalin-fixed human adult cadavers. The borders of each triangle were measured using a digital calliper and the areas were calculated using Herons Formula. The average area of the ST is 969.82±153.15 mm2 , while the average area of the IST is 307.48±41.31 mm2 . No statistically significant differences in the findings were observed between the sides of the body, ancestry, or sex of the cadavers. Measurement and analysis of these triangles provided important anatomical information and speak to their clinical relevance as surgical landmarks with which to locate the vertebral artery. Of particular importance here is the IST, which allows for mobilisation of this artery more proximally, should the ST be occluded.http://www.acbjournal.orgAnatom

Isthmus of the corpus callosum – an anatomical investigation

DATA AVAILABILITY STATEMENT : The dataset is available from the corresponding author with a reasonable request.INTRODUCTION : The corpus callosum, a principal commissural fibre-bundle of the brain, connects the two cerebral hemispheres, facilitating interhemispheric communication, cognitive and emotional processes. The anatomical definition of the isthmus of the corpus callosum remains unclear in literature with limited studies focusing on this region. This research addresses this gap by providing a detailed anatomical description of the isthmus of the corpus callosum in a South African cadaveric sample. METHODS : Digital photographs of thirty embalmed cadaver brains were analysed and measurements of the corpus callosum and isthmus were taken, as seen on a midsagittal section. RESULTS : The results revealed no significant differences in isthmus measurements when comparing the sex of the cadavers. The average length of the isthmus accounted for approximately 16.66 % of the total length of the corpus callosum. The isthmus constituted approximately 17.92 % of the corpus callosum surface area. Females tend to have a larger isthmus relative to the size of their corpus callosum. The prevalence of a posterior notch on the superior border of the corpus callosum was found to be approximately 46.66 % in the studied sample, with males showing a slightly higher prevalence. CONCLUSION : Since the isthmus constituted almost 20 % of the total surface area of the corpus callosum, as seen on midsagittal sections, it should be acknowledged as a fifth part. It should further be included in the undergraduate neuroanatomy curriculum and textbooks, which is currently lacking this information. This research recommends expanding the sample size, encompassing diverse demographics, employing fresh cadavers, and utilize three-dimensional imaging to understand the isthmus of the corpus callosum and its relevance to neuropsychiatric conditions and brain morphology.https://www.elsevier.com/locate/triahj2024AnatomySDG-03:Good heatlh and well-beingSDG-04:Quality Educatio

Neurophobia : the inconvenient truth

Medical schools have implemented strategies in response to neurophobia to counteract the negative perception and improve neuroscience experiences for undergraduate medical students. In this study, we explored the attitudes, perceptions and preferred learning approaches of undergraduate and postgraduate medical students toward the teaching, facilitation, learning and assessment of neuroanatomy, as well as their perceptions on its relevance in the South African medical curriculum. A total of 299 undergraduate and five postgraduate students from the University of Pretoria participated in this study. We used a multi-method approach in which the undergraduate students completed an anonymous quantitative questionnaire, while the postgraduate students participated in a qualitative focus- group discussion. Undergraduate medical students preferred lecture notes to study from above any other type of literature and mainly used laptop computers as preferred electronic devices in preparation for their assessments. The favourite topic was cranial nerves, and the least popular was histology of the nervous system. Postgraduate students shared their undergraduate neuroanatomy experiences and provided constructive feedback and suggestions to undergraduate students and lecturing staff. Ineffective teaching methods and limited contact time remain factors that contribute to neurophobia in South Africa. Students perceive neuroanatomy as an interesting and important subject in their medical degree. However, changes are needed to modernize neuroanatomy and make it more accessible and student-friendly. The challenge then remains: how do we, as lecturers, modernize neuroanatomy in the medical curriculum to make it contemporary and clinically applicable?https://eurjanat.comam2024AnatomyEducation InnovationSDG-04:Quality Educatio

Degenerative trends of the palmaris longus muscle in a South African population

The literature reports that the palmaris longus muscle (PL) is only found in mammals in which the forelimbs are weight-bearing extremities. It is suggested that the function of this muscle has been taken over by the other flexors in the forearm. Terms used in the literature to describe the diminishing of this muscle include retrogressive or phylogenetic degenerative trends. The aims of this study were to determine the prevalence of PL in a South African population and whether a phylogenetic degenerative trend for the PL exists. To determine the prevalence of the PL, five groups, representing different age intervals (Years 0–20, 21–40, 41–60, 61–80, and 81–99) were used. A sample of 706 participants of various ages was randomly selected. Statistical analysis included comparisons of the prevalence of the muscle between males and females and left and right sides, using a student t-test. A Chi-squared test was used to determine a possible phylogenetic degenerative trend of PL within the five groups. The sample yielded a bilateral absence of the PL in 11.9% of the cases. The muscle was unilaterally absent on the left side in 7.65% and 6.94% on the right side. The Chi-squared tests revealed a P-value of 0.27 for the left arm and 0.39 for the right arm. No obvious trend could be established for the phylogenetic degeneration of the PL in this study. It would appear that the PL muscle should not be considered as a phylogenetically degenerating muscle in a South African population.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2353hb201

Pantoea bathycoeliae sp. nov and Sodalis sp. are core gut microbiome symbionts of the two-spotted stink bug

DATA AVAILABILITY STATEMENT : The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found at: https://www.ncbi.nlm.nih.gov/genbank/, BioProject PRJNA972719 and PRJNA987703.Stink bug species (Pentatomoidea superfamily) have developed an interdependence with obligate bacterial gut symbionts in specialized midgut crypts (M4 sub-region). Species of the Enterobacteriaceae family (predominantly Pantoea) are vertically transferred to their offspring and provide nutrients that cannot be obtained from plant sap food sources. However, the bacteria in the other gut compartments of stink bugs have rarely been investigated. The two-spotted stink bug, Bathycoelia distincta, is a serious pest of macadamias in South Africa. Nothing is currently known regarding its gut microbiome or how symbionts are transferred between insect generations. In this study, the consistency of B. distincta gut bacteria across geographic locations and life stages was determined with 16S rRNA metabarcoding, considering both the M4 and other gut compartments. A novel Pantoea species was found to be the primary M4 gut symbiont and is vertically transferred to the offspring. The other gut compartments had a low bacterial diversity and genera varied between stink bug populations but a Sodalis species was prominent in all populations. Sequence data of the M4 compartment were used to produce high-quality metagenome-assembled genomes (MAGs) for the Pantoea and Sodalis species. Functional analyses suggested a similar role in nutrient provision for the host, yet also unique metabolites produced by each species. The Sodalis sp. also had additional traits, such as secretion systems, that likely allowed it to establish itself in the host. The Pantoea species was described as Pantoea bathycoeliae sp. nov based on the rules of the SeqCode.The Forestry and Agricultural Biotechnology Institute at the University of Pretoria and the South African Macadamia Association (SAMAC).http://www.frontiersin.org/Microbiologyam2024BiochemistryGeneticsMicrobiology and Plant PathologySDG-15:Life on lan

A morphological study of the shape of the corpus callosum in normal, schizophrenic and bipolar patients

Abnormalities in the morphology of the corpus callosum have been found to be involved in cognitive impairments or abnormal behaviour in patients with mental disorders such as schizophrenia and bipolar disorder. The present study investigated morphological shape differences of the corpus callosum in a large cohort of 223 participants between normal, schizophrenic and bipolar patients on MRI scans, CT scans and cadaver samples. Healthy samples were compared to a mental disorder population sample to determine morphological shapes variations associated with schizophrenia and bipolar disorder. Landmark-based methodology was used to contour the corpus callosum shape that served as standard positions to allow for radial and thickness partitioning in order to determine shape variations within the specific localised anatomical sections of the corpus callosum. Shape analysis was performed using Ordinary Procrustes averaging and superimposing landmarks to define an average landmark position for the specific regions of the corpus callosum. No significant global shape differences were found between the different mental disorders. Schizophrenia and bipolar shapes differed mostly in the genu-rostrum, posterior body, isthmus and splenium. Sample group comparisons yielded significant differences between all groups and global measurement parameters and in various sub-regions. The findings of the present study suggest that the corpus callosum in schizophrenia and bipolar differs significantly compared to healthy controls, specifically in the anterior body and isthmus for schizophrenia and only in the isthmus for bipolar disorder. Shape changes in these regions may possibly, in part, be responsible for the symptoms and cognitive impairments observed in schizophrenia and bipolar disorder.http://wileyonlinelibrary.com/journal/joahj2023AnatomyPhysiolog

Evaluation of the inion and asterion as neurosurgical landmarks for dural venous sinuses: osteological study on a sample of South African skull specimens

BACKGROUND : Sub-Saharan neurosurgeons most likely need to perform invasive procedures without the latest imaging and navigation technology in the operating room. Therefore, these surgeons need to utilize other methods such as superficial surface landmarks for neuro-navigation. Bony landmarks, including the inion and asterion, are commonly used during invasive procedures to pinpoint the location of the confluence of sinuses and transverse-sigmoid sinus junction, respectively. The purpose of this study was to investigate whether the inion and asterion can be used as superficial landmarks for the confluence of sinuses and the transverse-sigmoid sinus junction, respectively, in a South African population. METHODS : Fifty South African human skulls were used (25 male, 25 female). The micro-focus X-ray radiography and tomography facility (MIXRAD) at Necsa scanned and created three-dimensional virtual images of the skull specimens. Reference points were then inserted on the images and the relation between bony landmarks and venous sinuses was documented. RESULTS : The inion was directly related to the confluence of sinuses in 4% of the sample, whereas the asterion was directly related to the transverse-sigmoid sinus junction in 28% of the cases, on both the right and left sides. CONCLUSIONS : This study confirmed that neither the inion, nor the asterion, are directly related the confluence of sinuses and transverse-sigmoid sinus junction, respectively. These bony landmarks are more likely to be located either inferior, or not related at all, to the investigated dural venous sinuses.https://www.minervamedica.it/en/journals/neurosurgical-sciences2022-04-01hj2022Anatom

Sesquiterpene lactones from Geigeria aspera Harv. and their cytotoxicity

Geigeria poisoning, referred to as ‘vermeersiekte’ is an important plant poisoning in southern Africa. Three sesquiterpene lactones, isogeigerin acetate (1) ivalin (2) and geigerin (3) were isolated and purified from Geigeria aspera Harv. (Asteraceae). Structures were deduced using 1 and 2D NMR spectroscopy and mass spectrometry, while the absolute configurations of compounds 1 and 3 were determined for the first time by X-ray crystal diffraction analyses. Cytotoxicity of isogeigerin acetate, ivalin and geigerin were compared by exposing a murine skeletal myoblast (C2C12) cell line to varying concentrations of the three sesquiterpene lactones isolated. Cell viability was assessed using the methyl-thiazolyl-tetrazolium (MTT) assay. The EC50s were 3.746, 0.0029 and 3.792 mM for isogeigerin acetate (1), ivalin (2) and geigerin (3), respectively. The results indicate that ivalin is much more toxic, approximately 1000 times, in vitro compared to isogeigerin acetate and geigerin.http://www.tandfonline.com/loi/gnpl202020-10-16hj2020ChemistryParaclinical Science