Search

INTRODUCTION: In South Africa, Xpert® MTB/RIF Ultra (Ultra) is the recommended diagnostic assay for TB with line-probe assays for first- (LPAfl) and second-line drugs (LPAsl) providing additional drug susceptibility testing (DST) for samples that were rifampicin-resistant (RR-TB). To guide implementation of the recently launched Xpert® MTB/XDR (MTB/XDR) assay, a cost-outcomes analysis was conducted comparing total costs for genotypic DST (gDST) for persons diagnosed with RR-TB considering three strategies: replacing LPAfl/LPAsl (centralised level) with MTB/XDR vs. Ultra reflex testing (decentralised level). Further, DST was performed using residual specimen following RR-TB diagnosis. METHODS: The total cost of gDST was determined for three strategies, considering loss to follow-up (LTFU), unsuccessful test rates, and specimen volume. RESULTS: For 2019, 9,415 persons were diagnosed with RR-TB. A 35% LTFU rate between RR-TB diagnosis and LPAfl/LPAsl-DST was estimated. Unsuccessful test rates of 37% and 23.3% were reported for LPAfl and LPAsl, respectively. The estimated total costs were $191,472 for the conventional strategy, $122,352 for the centralised strategy, and $126,838 for the decentralised strategy. However, it was found that sufficient residual volume for reflex MTB/XDR testing is a limiting factor at the decentralised level. CONCLUSION: Centralising the implementation of XDR testing, as compared to LPAfl/LPAsl, leads to significant cost savings.

Introduction: Lentigo maligna (LM) and lentigo maligna melanoma (LMM) predominantly affect the head and neck areas in elderly patients, presenting as challenging ill-defined pigmented lesions with indistinct borders. Surgical margin determination for complete removal remains intricate due to these characteristics. Morphological examination of surgical margins is the key form of determining successful treatment in LM/LMM and underpin the greater margin control provided through the Slow Mohs micrographic surgery (SMMS) approach. Recent assessments have explored the use of immunohistochemistry (IHC) markers, such as Preferentially Expressed Antigen in Melanoma (PRAME), to aid in LM/LMM and margin evaluation, leveraging the selectivity of PRAME labelling in malignant melanocytic neoplasms.Methods: A Novel double-labelling (DL) method incorporating both PRAME and MelanA IHC was employed to further maximise the clinical applicability of PRAME in the assessment of LM/LMM in SMMS biopsies. The evaluation involved 51 samples, comparing the results of the novel DL with respective single-labelling (SL) IHC slides.Results: The findings demonstrated a significant agreement of 96.1% between the DL method and SL slides across the tested samples. The benchmark PRAME SL exhibited a sensitivity of 91.3% in the SMMS specimens and 67.9% in histologically confirmed positive margins.Discussion: This study highlights the utility of PRAME IHC and by extension PRAME DL as an adjunctive tool in the assessment of melanocytic tumours within staged excision margins in SMMS samples.

Abstract Background Effective communication is imperative for successful interprofessional collaborative interactions that augment both patient-centred and evidence based care. Inquiry into the prevalence of chiropractic-related terminology on South African chiropractor’s webpages has not been explored to date. The implications of such analysis could indicate the professions’ ability to effectively communicate in interdisciplinary settings. Method From 1 to 15 June 2020, Google search was used to identify the webpages (excluding social media accounts) of South African private practice chiropractors registered with the Allied Health Professions Council of South Africa (AHPCSA). Webpages were word-searched for eight chiropractic terms with context: subluxation; manipulate(-ion); adjust(-ing/-ment); holism(-tic); alignment; vital(-ism/-istic); wellness; and innate intelligence. Data collected was transferred to an Excel spreadsheet. Accuracy of information was verified by the researchers through a process of double checking. The number of instances each term was used, and certain socio-demographic data were recorded. Descriptive statistics and bivariate analyses were used to summarise and analyse the data. Results Among 884 AHPCSA-registered South African chiropractors, 336 webpages were identified and analysed. From 1 to 15 June 2020, the most commonly found terms on 336 South African chiropractic webpages were 'adjust(-ing/-ment)', 'manipulate/manipulation', and 'wellness', with prevalence estimates of 64.1% (95% confidence interval [CI], 59.0% to 69.2%), 51.8% (95% CI, 46.5% to 57.1%), and 33.0% (95% CI, 28.2% to 38.2%), respectively. The least commonly found terms were 'innate intelligence' and 'vital(-ism/-istic)', with prevalence estimates of 0.60% (95% CI, 0.16% to 2.1%) and 0.30% (95% CI, 0.05% to 1.7%), respectively. Manipulate(-ion) was used more by male chiropractors (p = 0.015). The longer a chiropractor was in practice the more likely they were to use profession-specific terms (p = 0.025). The most frequently occurring combination of terms were adjust(-ing/-ment) and manipulate(-ion), found in 38 out of 336 webpages (11.3%; 95% CI, 8.4% to 15.1%). Conclusion The use of chiropractic-related terminology on South African chiropractic webpages was common, with the prevalence of term use varying by type of terms, by gender of the chiropractor, and by clinical practice experience. Better understanding of the effects of chiropractic terminology use on interprofessional and patient interactions and communication is warranted.

Introduction Neurocognitive deficits amongst patients with schizophrenia are considered one of schizophrenia’s central features. These deficits appear to be present from the first episode of psychosis (FEP) and certain cognitive impairments could be components of a genetic vulnerability to schizophrenia. Regarding research on cannabis and cognition in schizophrenia, different studies have assessed neurocognitive functions: memory, attention/vigilance, processing speed, verbal learning, executive functions, and verbal fluency. Objectives The aim is to do a review of recent findings concerning the association of cannabis use with cognition in schizophrenia. Methods A literature review was conducted using the PubMed search database. Results Patients with schizophrenia and concomitant cannabis use are associated with worse performance in immediate verbal learning, and in some studies with worse working memory performance. There is an improvement of verbal memory when they cease the cannabis’ consumption. Regarding attention capacity and memory types assessed, the results are controversial. In FEP, heavy cannabis use during the previous year correlates with slower processing speed. Also, FEP-patients with cannabis use but no family history of psychosis perform worse in executive functions, while those with a family history of psychosis perform better. Conclusions The studies of psychosis, cannabis and cognition differ in relevant aspects, which might be connected to the result variability. Therefore, before solid conclusions can be reached, it is important to carry out longitudinal studies to understand the changes in the cognitive variables, which can depend on the pattern of cannabis’ use (concurrent or prior to the FEP). Possible confounding variables that might be present should be acknowledged. Disclosure No significant relationships.

Introduction Seizures occur in about 3% cases of alcohol withdrawal. They usually appear within 48 hours after abrupt cessation, and are characterized by a reduction in seizure threshold secondary to adaptation to alcohol. More than 50% of individuals will experience a new seizure and in 5% of these cases, progression to a sustained epilepticus status can occur. Objectives The aim is to do a review of the literature on alcohol withdrawal and the onset of seizures in individuals with alcohol addiction. Methods A literature review was conducted using the PubMed search database. Results Alcohol is a central nervous system (CNS) depressant and chronic consumption causes neuroadaptation in order to maintain homeostasis. This adaptation involves the upregulation of excitatory neurotransmitters systems and the downregulation of inhibitory ones. When consumption is abruptly discontinued, the depressive contribution of alcohol to a previously established balance is disrupted, resulting in withdrawal symptoms associated to a generalized CNS’ hyperexcitability state.Critical episodes increase the risk of delirium tremens, a fatal condition in 20% of untreated cases. Thus, the treatment and prevention of seizure recurrences is essential: the clinical guidelines of the American Society of Addiction Medicine 2020, offer an action proposal. Pharmacological therapy after seizures is the preferential treatment: intravenous administration of fast-acting benzodiazepines (lorazepam and diazepam) is the first line treatment. Conclusions It is essential to monitor signs and symptoms that alert us to the appearance of seizures associated to alcohol withdrawal, effectively treat these cases, prevent recurrences, and provide a quality follow-up for these patients. Disclosure No significant relationships.

Introduction On March, 2020, the World Health Organization (WHO) declared the COVID-19 outbreak a global pandemic. Social isolation, unemployment and financial difficulties can have an impact on mental health and trigger the use of alcohol as a form of coping. Since the beginning of this pandemic, the WHO had warned the general public of the potential risks of increased alcohol consumption, which might result in a higher incidence of alcohol use disorders (AUD) in future. Objectives The aim is to do a review of the literature of alcohol consumption during the COVID-19 pandemic. Methods Non-systematic review of the literature with selection of scientific articles published in the last 7 months; by searching the Pubmed databases, the following MeSH terms were used: COVID-19; alcohol consumption. Results A recent article in The Lancet suggested that mental health and alcohol use during the pandemic, a major public health concern, are worthy of attention. Market research showed that alcohol sales increased in several countries compared to the same time last year. However, with the closure of several drinking places, sales are not in themselves reliable enough estimates of alcohol consumption. On the other hand, economic crises can lead to a reduction in alcohol consumption, due to financial problems or the risk of unemployment. Conclusions The present global circumstance is unique, and there is a need for further research on the relationship between alcohol consumption and COVID-19 to understand its long-term effects and develop specific prevention programs for this population.

Using the case study of Singapore’s existing heritage websites, this research will probe the circumstances of the emerging technology and practice of consuming heritage architecture on a digital platform. Despite the diverse objectives, technology is assumed to help deliver greater interpretation through the use of new and high technology emphasising experience and provide visual fidelity. However, the success is limited as technology is insufficient to provide the past from multiple perspectives. Currently, existing projects provide linear narratives developed through a top-down approach that assumes the end-users as an individual entity and limits heritage as a consumable product. Through this research, we hope to uncover for better experience of digital heritage architecture where interpretation is an evolving ‘process’ that is participatory and contributory that allows public participation, together with effective presentation, cultural learning and embodiment, to enhance the end-users’ interpretation of digital heritage architecture. Additionally, this research seeks to establish an inventory in the form of a digital platform that adopts the Historic Urban Landscape (HUL) into the Singapore context to better and deepen the understandings of the public towards architectural as well as cultural heritage through an intercultural and intergenerational dialogue. Through HUL, this research hopes that it will better shape conservation strategies and urban planning.

The scrotal varicocele is a common finding encountered during clinical examination. A porto-systemic shunt presenting with an associated varicocele is exceptionally rarely reported. Herein, we report such a case in an HIV positive man who presented with bilateral varicoceles. This is only the fifth case of such an association in the world literature. A literature review and the possible underlying pathophysiological mechanisms of this rare association are expanded further.

Exponentially fitted and trigonometrically fitted explicit modified Runge-Kutta type (MRKT) methods for solving y′′′x=fx,y,y′ are derived in this paper. These methods are constructed which exactly integrate initial value problems whose solutions are linear combinations of the set functions eωx and e-ωx for exponentially fitted and sin⁡ωx and cos⁡ωx for trigonometrically fitted with ω∈R being the principal frequency of the problem and the frequency will be used to raise the accuracy of the methods. The new four-stage fifth-order exponentially fitted and trigonometrically fitted explicit MRKT methods are called EFMRKT5 and TFMRKT5, respectively, for solving initial value problems whose solutions involve exponential or trigonometric functions. The numerical results indicate that the new exponentially fitted and trigonometrically fitted explicit modified Runge-Kutta type methods are more efficient than existing methods in the literature.

The demand of many scientific areas for the usage of fractional partial differential equations (FPDEs) to explain their real-world systems has been broadly identified. The solutions may portray dynamical behaviors of various particles such as chemicals and cells. The desire of obtaining approximate solutions to treat these equations aims to overcome the mathematical complexity of modeling the relevant phenomena in nature. This research proposes a promising approximate-analytical scheme that is an accurate technique for solving a variety of noninteger partial differential equations (PDEs). The proposed strategy is based on approximating the derivative of fractional-order and reducing the problem to the corresponding partial differential equation (PDE). Afterwards, the approximating PDE is solved by using a separation-variables technique. The method can be simply applied to nonhomogeneous problems and is proficient to diminish the span of computational cost as well as achieving an approximate-analytical solution that is in excellent concurrence with the exact solution of the original problem. In addition and to demonstrate the efficiency of the method, it compares with two finite difference methods including a nonstandard finite difference (NSFD) method and standard finite difference (SFD) technique, which are popular in the literature for solving engineering problems.

Two-step optimized hybrid methods of order five and order six are developed for the integration of second order oscillatory initial value problems. The optimized hybrid method (OHMs) are based on the existing nonzero dissipative hybrid methods. Phase-lag, dissipation or amplification error, and the differentiation of the phase-lag relations are required to obtain the methods. Phase-fitted methods based on the same nonzero dissipative hybrid methods are also constructed. Numerical results show that OHMs are more accurate compared to the phase-fitted methods and some well-known methods appeared in the scientific literature in solving oscillating second order initial value problems. It is also found that the nonzero dissipative hybrid methods are more suitable to be optimized than phase-fitted methods.

We constructed three two-step semi-implicit hybrid methods (SIHMs) for solving oscillatory second order ordinary differential equations (ODEs). The first two methods are three-stage fourth-order and three-stage fifth-order with dispersion order six and zero dissipation. The third is a four-stage fifth-order method with dispersion order eight and dissipation order five. Numerical results show that SIHMs are more accurate as compared to the existing hybrid methods, Runge-Kutta Nyström (RKN) and Runge-Kutta (RK) methods of the same order and Diagonally Implicit Runge-Kutta Nyström (DIRKN) method of the same stage. The intervals of absolute stability or periodicity of SIHM for ODE are also presented.

In this paper, we propose an iterative spectral method for solving differential equations with initial values on large intervals. In the proposed method, we first extend the Legendre wavelet suitable for large intervals, and then the Legendre-Guass collocation points of the Legendre wavelet are derived. Using this strategy, the iterative spectral method converts the differential equation to a set of algebraic equations. Solving these algebraic equations yields an approximate solution for the differential equation. The proposed method is illustrated by some numerical examples, and the result is compared with the exponentially fitted Runge-Kutta method. Our proposed method is simple and highly accurate.

Two new Runge-Kutta-Nyström (RKN) methods are constructed for solving second-order differential equations with oscillatory solutions. These two new methods are constructed based on two existing RKN methods. Firstly, a three-stage fourth-order Garcia’s RKN method. Another method is Hairer’s RKN method of four-stage fifth-order. Both new derived methods have two variable coefficients with phase-lag of order infinity and zero amplification error (zero dissipative). Numerical tests are performed and the results show that the new methods are more accurate than the other methods in the literature.

This paper focuses on the derivation of diagonally implicit two-point block backward differentiation formulas (DI2BBDF) for solving first-order initial value problem (IVP) with two fixed points. The method approximates the solution at two points simultaneously. The implementation and the stability of the proposed method are also discussed. A performance of the DI2BBDF is compared with the existing methods.

An exponentially fitted explicit hybrid method for solving oscillatory problems is obtained. This method has four stages. The first three stages of the method integrate exactly differential systems whose solutions can be expressed as linear combinations of {1,x,exp(μx),exp(−μx)},μ∈C, while the last stage of this method integrates exactly systems whose solutions are linear combinations of {1,x,x2,x3,x4,exp(μx),exp(−μx)}. This method is implemented in variable step-size code basing on an embedding approach. The stability analysis is given. Numerical experiments that have been carried out show the efficiency of our method.