Ascorbic acid causes spuriously low blood glucose measurements

CITATION: Strijdom, J.G., Marais, B.J. & Koeslag, J.H. 1993. Ascorbic acid causes spuriously low blood glucose measurements. S Afr Med J, 83(1):64-65.The original publication is available at http://www.samj.org.za[No abstract available]Publisher’s versio

Clustered bottlenecks in mRNA translation and protein synthesis

We construct an algorithm that generates large, band-diagonal transition matrices for a totally asymmetric exclusion process (TASEP) with local hopping rate inhomogeneities. The matrices are diagonalized numerically to find steady-state currents of TASEPs with local variations in hopping rate. The results are then used to investigate clustering of slow codons along mRNA. Ribosome density profiles near neighboring clusters of slow codons interact, enhancing suppression of ribosome throughput when such bottlenecks are closely spaced. Increasing the slow codon cluster size, beyond $\approx 3-4$, does not significantly reduce ribosome current. Our results are verified by extensive Monte-Carlo simulations and provide a biologically-motivated explanation for the experimentally-observed clustering of low-usage codons

A phenomenological exploration into the personal experience and impact of therapist self-disclosure on the therapist

Extensive research has been carried out on self-disclosure within the therapeutic relationship. The emphasis remains on disclosure offering therapeutic benefit for the client. Thus, the therapist primarily enters the therapeutic space in the service of healing for the client. However, it may be that they too (therapists) in their position as a ‘wounded healer’ (Jung, 1993) receive some relief, benefits, or discomforts to themselves regarding their unresolved deficits, traumas and emotional injuries as a result of their shared self-disclosures. Researching this topic highlighted a potential gap in this area, namely what was the impact and personal experience of therapist self-disclosure on the disclosing therapist? A Qualitative methodology encompassing Interpretative Phenomenological Analysis (IPA) felt appropriate as it allowed for non-intrusive enquiries whilst giving participants the flexibility and freedom to share their individual, unique findings and meaning-making in their purest form (Smith, Flowers & Larkin, 2009). This study was interested in exploring the impact and experience of therapist self-disclosure on the disclosing therapist. A sample size of five therapists was interviewed. The participants’ subjective and personal experiences of this phenomenon were explored and investigated via an in-depth, semi-structured interview. The data analysis and interpretation of the data produced three master themes: firstly, ‘what is self-disclosure’ - exploring the complexities involved in this phenomenon. The second master theme, ‘risks involved in therapist self-disclosure’ focused on explorations into professional and relationship risks. The final master theme explored ‘the personal impact and experience of therapist self-disclosure on the disclosing therapist’. This involved the emotional and psychological impact of therapist self-disclosure on the therapist, power awareness, the therapist’s use of self and the therapist as a ‘wounded healer’. This study highlighted the importance of therapists remaining cognisant of the complexities involved in therapist self-disclosure and its impact upon them (and by implication the client). In this way, they may honour the duality existing within this phenomenon. The findings highlighted that therapists are indeed impacted on a personal level by their self-disclosures. Thus, training programmes and supervision need to give greater focus to and guidelines for the use of therapist self-disclosure in relation to trainees and newly qualified therapists as these aspects all have implications for better practice, self-care, training and ethics

Total anomalous pulmonary venous connection to an unroofed coronary sinus diagnosed in a fetus with associated spinal muscular atrophy type I

Total anomalous pulmonary venous connection (TAPVC) to unroofed coronary sinus is a rare cardiac condition. We report the first case of antenatal diagnosis which had a rapid and fatal neonatal course due to spinal muscular atrophy (SMA) type I (Werdnig-Hoffmann disease). The diagnosis of TAPVC with unroofing of the coronary sinus was made at 26 weeks’ gestation, although a dilated inferior caval vein had been recognised at 23 weeks’ gestation. Due to profound hypotonia after birth, genetic review followed by muscle biopsy was performed due to presumptive diagnosis of SMA. The infant deteriorated rapidly, became ventilator dependent and died at the age of 6 weeks. The worst types of SMA are associated with only one copy of SMN2 (survival motor neuron 2) protein, which was also the case of our infant. Although a powerful association with congenital heart defects was described, it has not been reported with TAPVC to unroofed coronary sinus. Moreover, this cardiac condition has not been previously recognised antenatally

Neutrophil-Associated Central Nervous System Inflammation in Tuberculous Meningitis Immune Reconstitution Inflammatory Syndrome.

Background. The immunopathogenesis of tuberculosis-associated immune reconstitution inflammatory syndrome (IRIS) remains incompletely understood, and we know of only 1 disease site-specific study of the underlying immunology; we recently showed that Mycobacterium tuberculosis culture positivity and increased neutrophils in the cerebrospinal fluid (CSF) of patients with tuberculous meningitis (TBM) are associated with TBM-IRIS. In this study we investigated inflammatory mediators at the disease site in patients with TBM-IRIS. Methods. We performed lumbar puncture at 3–5 time points in human immunodeficiency virus (HIV)–infected patients with TBM (n = 34), including at TBM diagnosis, at initiation of antiretroviral therapy (ART) (day 14), 14 days after ART initiation, at presentation of TBM-IRIS, and 14 days thereafter. We determined the concentrations of 40 mediators in CSF (33 paired with blood) with Luminex or enzyme-linked immunosorbent assays. Findings were compared between patients who developed TBM-IRIS (n = 16) and those who did not (TBM-non-IRIS; n = 18). Results. At TBM diagnosis and 2 weeks after ART initiation, TBM-IRIS was associated with severe, compartmentalized inflammation in the CSF, with elevated concentrations of cytokines, chemokines, neutrophil-associated mediators, and matrix metalloproteinases, compared with TBM-non-IRIS. Patients with TBM-non-IRIS whose CSF cultures were positive for M. tuberculosis at TBM diagnosis (n = 6) showed inflammatory responses similar to those seen in patients with TBM-IRIS at both time points. However, at 2 weeks after ART initiation, S100A8/A9 was significantly increased in patients with TBM-IRIS, compared with patients with TBM-non-IRIS whose cultures were positive at baseline. Conclusions. A high baseline M. tuberculosis antigen load drives an inflammatory response that manifests clinically as TBM-IRIS in most, but not all, patients with TBM. Neutrophils and their mediators, especially S100A8/A9, are closely associated with the central nervous system inflammation that characterizes TBM-IRIS

QuantiFERON®-TB gold in-tube performance for diagnosing active tuberculosis in children and adults in a high burden setting.

To determine whether QuantiFERON®-TB Gold In-Tube (QFT) can contribute to the diagnosis of active tuberculosis (TB) in children in a high-burden setting and to assess the performance of QFT and tuberculin skin test (TST) in a prospective cohort of TB suspect children compared to adults with confirmed TB in Tanzania. Sensitivity and specificity of QFT and TST for diagnosing active TB as well as indeterminate QFT rates and IFN-γ levels were assessed in 211 TB suspect children in a Tanzanian district hospital and contrasted in 90 adults with confirmed pulmonary TB. Sensitivity of QFT and TST in children with confirmed TB was 19% (5/27) and 6% (2/31) respectively. In adults sensitivity of QFT and TST was 84% (73/87) and 85% (63/74). The QFT indeterminate rate in children and adults was 27% and 3%. Median levels of IFN-γ were lower in children than adults, particularly children <2 years and HIV infected. An indeterminate result was associated with age <2 years but not malnutrition or HIV status. Overall childhood mortality was 19% and associated with an indeterminate QFT result at baseline. QFT and TST showed poor performance and a surprisingly low sensitivity in children. In contrast the performance in Tanzanian adults was good and comparable to performance in high-income countries. Indeterminate results in children were associated with young age and increased mortality. Neither test can be recommended for diagnosing active TB in children with immature or impaired immunity in a high-burden setting

Earthshine observation of vegetation and implication for life detection on other planets - A review of 2001 - 2006 works

The detection of exolife is one of the goals of very ambitious future space missions that aim to take direct images of Earth-like planets. While associations of simple molecules present in the planet's atmosphere ($O_2$, $O_3$, $CO_2$ etc.) have been identified as possible global biomarkers, we review here the detectability of a signature of life from the planet's surface, i.e. the green vegetation. The vegetation reflectance has indeed a specific spectrum, with a sharp edge around 700 nm, known as the "Vegetation Red Edge" (VRE). Moreover vegetation covers a large surface of emerged lands, from tropical evergreen forest to shrub tundra. Thus considering it as a potential global biomarker is relevant. Earthshine allows to observe the Earth as a distant planet, i.e. without spatial resolution. Since 2001, Earthshine observations have been used by several authors to test and quantify the detectability of the VRE in the Earth spectrum. The egetation spectral signature is detected as a small 'positive shift' of a few percents above the continuum, starting at 700 nm. This signature appears in most spectra, and its strength is correlated with the Earth's phase (visible land versus visible ocean). The observations show that detecting the VRE on Earth requires a photometric relative accuracy of 1% or better. Detecting something equivalent on an Earth-like planet will therefore remain challenging, moreover considering the possibility of mineral artifacts and the question of 'red edge' universality in the Universe.Comment: Invited talk in "Strategies for Life Detection" (ISSI Bern, 24-28 April 2006) to appear in a hardcopy volume of the ISSI Space Science Series, Eds, J. Bada et al., and also in an issue of Space Science Reviews. 13 pages, 8 figures, 1 tabl