Does the knowledge of the human immunodeficiency virus serostatus influence the clinical diagnostic proficiency of Kaposi’s sarcoma?

Objectives: Kaposi’s sarcoma is an acquired immunodeficiency syndrome (AIDS)-defining illness. A spectrum of non- Kaposi’s sarcoma clinical and histopathological mimickers contributes to the potential over- or underdiagnosis of Kaposi’s sarcoma. The aim of this audit was to investigate the clinical diagnostic accuracy of Kaposi’s sarcoma and to find out whether or not knowledge of the human immunodeficiency virus (HIV) serostatus influenced the clinical diagnostic accuracy.Design: Cross-sectional study of 511 mucocutaneous biopsies.Settings and subjects: All the biopsies were from African patients from the Limpopo province. The HIV seropositive status was known in 327 cases (64.2%). The clinical diagnosis, provided in 369 cases (72.2%) was compared with the biopsy. A Kaposi’s sarcoma herpesvirus-positive immunophenotype on biopsy served as the diagnostic gold standard.Outcome measure: Concordance or discordance between the clinical provisional diagnosis and the histopathological gold standard.Results: The rate of provisional clinical diagnosis of non- Kaposi’s sarcoma in biopsy-proven Kaposi’s sarcoma was 18.1% in HIV-positive, and 39.5% in HIV unknown, serostatus (chi-square 11.8, p-value = 0.0006). The concordance between the clinical diagnosis and biopsy was 76.5% in the HIV-positive, and 49.9% in the HIV-unknown, cases (chi-square 16.9, p-value < 0.0001).Conclusion: Knowledge of the patient’s serostatus significantly improved the clinical diagnostic accuracy of Kaposi’s sarcoma. Biopsy remains the diagnostic gold standard.Keywords: Kaposi’s sarcoma, mimics, clinical diagnosis, HI

Die aard van wetgewende diskresies by die Suid-Afrikaanse uitvoerende gesag

This article focuses on the nature of legislative discretions in the hands of the executive authority of the state. Relevant concepts are analysed, followed by an exposition of the position regarding delegation of legislative authority to the executive under the previous constitutional dispensation when the country had a sovereign Parliament. This is followed by a discussion of the legal position in Germany, which shows similarities to the situation in South Africa. It appears that differences in approach to the problem exist worldwide, but one similarity is to be found in all, namely that a complete parliamentary abdication of legislative authority is always disallowed. What follows from this is that South African law seems to follow the German example regarding the delegation of legislative powers. It seems that the South African Constitutional Court considers the delegation of essential legislative authority as undesirable. Limits have to be placed on the extent of Parliament's competencies pertaining to legislative delegation. Furthermore the manner and form requirements in the Constitution must be met when legislation is adopted. This however does not occur in all instances of legislative delegation to the executive authority. When legislative delegation takes place, it is consistently done by granting the executive the authority to adopt subordinate legislation, which in any event has the same legal effect as legislation of Parliament itself. Next the Transitional Constitution of 1993 is considered against the background of relevant case law. It appears that the legal position was not changed by the promulgation of the ("final") Constitution of 1996. Empowering legislation that delegates any legislative authority must lay down guidelines providing direction regarding the exercise of the delegated authority. Delegated legislation may of course not contain substantive norms. Like the German Bundesverfassungsgericht, the South African Constitutional Court seems to require empowering legislation to lay down the content, extent and purpose of the empowering provisions before it will enjoy legal effect. This content, extent and purpose will not primarily be evident from the delegated legislation, but must be contained in the empowering legislation itself. If this is not the case, the delegation of authority will have exceeded constitutional limits. Therefore, a wide delegation of legislative authority without limitations regarding its exercise, at least as far as content, extent and purpose are concerned, will without doubt be unconstitutional

The role of optical coherence tomography and infrared oculography in assessing the visual pathway and CNS in multiple sclerosis

In this review, a current overview is provided of how optical coherence tomography and infrared oculography can aid in assessing the visual system and CNS in multiple sclerosis (MS). Both afferent and efferent visual disorders are common in MS and visual complaints can have a tremendous impact on daily functioning. Optical coherence tomography and infrared oculography can detect and quantify visual disorders with high accuracy, but could also serve as quantitative markers for inflammation, neurodegeneration and network changes including cognitive decline in MS patients. The assessment of the efferent and afferent visual pathways is relevant for monitoring and predicting the disease course, but is also potentially valuable as an outcome measure in therapeutic trials

In-line near infrared spectroscopy during freeze-drying as a tool to measure efficiency of hydrogen bond formation between protein and sugar, predictive of protein storage stability

Sugars are often used as stabilizers of protein formulations during freeze-drying. However, not all sugars are equally suitable for this purpose. Using in-line near-infrared spectroscopy during freeze-drying, it is shown here that hydrogen bond formation during freeze-drying, under secondary drying conditions in particular, can be related to the preservation of the functionality and structure of proteins during storage. The disaccharide trehalose was best capable of forming hydrogen bonds with the model protein, lactate dehydrogenase, thereby stabilizing it, followed by the molecularly flexible oligosaccharide inulin 4kDa. The molecularly rigid oligo- and polysaccharides dextran 5kDa and 70kDa, respectively, formed the least amount of hydrogen bonds and provided least stabilization of the protein. It is concluded that smaller and molecularly more flexible sugars are less affected by steric hindrance, allowing them to form more hydrogen bonds with the protein, thereby stabilizing it better

RAB25 expression is epigenetically downregulated in oral and oropharyngeal squamous cell carcinoma with lymph node metastasis

Oral and oropharyngeal squamous cell carcinoma (OOSCC) have a low survival rate, mainly due to metastasis to the regional lymph nodes. For optimal treatment of these metastases, a neck dissection is required; however, inaccurate detection methods results in under- and over-treatment. New DNA prognostic methylation biomarkers might improve lymph node metastases detection. To identify epigenetically regulated genes associated with lymph node metastases, genome-wide methylation analysis was performed on 6 OOSCC with (pN+) and 6 OOSCC without (pN0) lymph node metastases and combined with a gene expression signature predictive for pN+ status in OOSCC. Selected genes were validated using an independent OOSCC cohort by immunohistochemistry and pyrosequencing, and on data retrieved from The Cancer Genome Atlas. A two-step statistical selection of differentially methylated sequences revealed 14 genes with increased methylation status and mRNA downregulation in pN+ OOSCC. RAB25, a known tumor suppressor gene, was the highest-ranking gene in the discovery set. In the validation sets, both RAB25 mRNA (P = 0.015) and protein levels (P = 0.012) were lower in pN+ OOSCC. RAB25 mRNA levels were negatively correlated with RAB25 methylation levels (P < 0.001) but RAB25 protein expression was not. Our data revealed that promoter methylation is a mechanism resulting in downregulation of RAB25 expression in pN+ OOSCC and decreased expression is associated with lymph node metastasis. Detection of RAB25 methylation might contribute to lymph node metastasis diagnosis and serve as a potential new therapeutic target in OOSCC

Comprehensive transcriptomic analysis of cell lines as models of primary tumors across 22 tumor types.

Cancer cell lines are a cornerstone of cancer research but previous studies have shown that not all cell lines are equal in their ability to model primary tumors. Here we present a comprehensive pan-cancer analysis utilizing transcriptomic profiles from The Cancer Genome Atlas and the Cancer Cell Line Encyclopedia to evaluate cell lines as models of primary tumors across 22 tumor types. We perform correlation analysis and gene set enrichment analysis to understand the differences between cell lines and primary tumors. Additionally, we classify cell lines into tumor subtypes in 9 tumor types. We present our pancreatic cancer results as a case study and find that the commonly used cell line MIA PaCa-2 is transcriptionally unrepresentative of primary pancreatic adenocarcinomas. Lastly, we propose a new cell line panel, the TCGA-110-CL, for pan-cancer studies. This study provides a resource to help researchers select more representative cell line models

Comment on ``Lyapunov Exponent of a Many Body System and Its Transport Coefficients''

In a recent Letter, Barnett, Tajima, Nishihara, Ueshima and Furukawa obtained a theoretical expression for the maximum Lyapunov exponent $\lambda_1$ of a dilute gas. They conclude that $\lambda_1$ is proportional to the cube root of the self-diffusion coefficient $D$, independent of the range of the interaction potential. They validate their conjecture with numerical data for a dense one-component plasma, a system with long-range forces. We claim that their result is highly non-generic. We show in the following that it does not apply to a gas of hard spheres, neither in the dilute nor in the dense phase.Comment: 1 page, Revtex - 1 PS Figs - Submitted to Physical Review Letter

How we see ‘Y’: South African health sciences students’ and lecturers’ perceptions of Generation Y students

Background. Health sciences education in the 21st century must recognise the changing profile of students, which includes an understanding of thecharacteristics of Generation Y students (born between 1981 and 2000) as future healthcare professionals.Objective. To examine the perceptions of students and lecturers regarding Generation Y students in health sciences that might impact on teachingand learning in a South African setting.Methods. A quantitative research approach was used to determine undergraduate students’ and lecturers’ perceptions of Generation Y students in the Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa. Anonymous questionnaires were used to obtain information.Results. The study population included students (n=616) and lecturers (n=71). Despite some shared perceptions about generational  characteristics, students and lecturers differed significantly on many issues. Unlike lecturers, students perceived themselves as being ambitious (not arrogant) and possessing superior cognitive skills. Despite desiring a  vibrant and stimulating learning environment, students wanted face-to-face contact with lecturers. Poor intergenerational communication also emerged as a pertinent issue.Conclusion. Identification of intergenerational issues that may impact on teaching and learning may contribute to developing novel educationalapproaches acceptable to both lecturers and students