Stevens Johnson Syndrome and Toxic Epidermal Necrolysis: Maternal and Foetal Outcomes in Twenty-Two Consecutive Pregnant HIV Infected Women

Introduction

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) form a spectrum of a rare and life-threatening cutaneous drug reaction. SJS/TEN in pregnancy poses largely unknown risk factors and outcomes for both the mother and foetus compared to the general population.

Methods

We conducted a study of consecutive pregnant women admitted to single tertiary referral centre in South Africa with SJS/TEN over a 3 year period. They were all managed by the same medical team using the same protocols. We evaluated their underlying illnesses, offending drugs and the course of pregnancy and outcomes to determine factors influencing maternal and foetal outcomes.

Results

We identified twenty-two women who developed SJS/TEN while pregnant, all of them HIV-infected. Their median age was 29 years. The majority 16/22 (73%) had SJS, the milder variant of the disease affecting < 10% body surface area. Nevirapine was the offending drug in 21/22 (95%) cases. All 22 of the mothers survived with 3/22 (14%) developing postpartum sepsis. Pregnancy outcomes were known in 18/22 women and 9/18 (50%) babies were delivered by caesarean section. There were 2 foetal deaths at 21 and 31 weeks respectively and both were associated with post-partum sepsis. Postnatal complications occurred in 5 cases, 3 involving the respiratory system and the other two being low birth weight deliveries. Eight placentae and one foetus were sent for histology and none showed macroscopic or microscopic features of SJS/TEN. On follow-up, only 12/20 children were tested for HIV at 6 weeks post-delivery and none of them were HIV-infected. All had received prophylactic ARVs including nevirapine.

Conclusions

TEN, the severe form of the disease, was associated with poorer foetal outcomes. SJS/TEN-associated mortality is not increased in HIV-infected pregnant women. Maternal SJS/TEN does not seem to commonly manifest in the foetus.     

Effects of pruning on the concentration of trace elements in Colophospermum mopane leaves

Despite the nutritional value of Colophospermum mopane to browser's diets, there is still insufficient knowledge on the effect of browsers on concentrations of these trace elements. A field experiment was conducted in Musina Nature Reserve, Limpopo Province, South Africa, to determine the effect of pruning on the concentration of trace elements in mopane leaves. Samples were analysed for iron (Fe), manganese (Mn), boron (B), molybdenum (Mo), copper (Cu), zinc (Zn), cobalt (Co), fluoride (F) and selenium (Se) using the inductively coupled plasma atomic emission spectrometry technique. The effect of pruning was tested using the two‐tailed t‐test: two‐sample assuming equal variance and two‐tailed Mann–Whitney U‐test. Results showed that the concentration of trace elements in the control and pruned trees varies slightly through the year. Fe, Mn, Mo, Cu, Zn and Se are higher during leaf flush, but declined as the leaves matured and aged. This study concluded that simulated browsing had no significant effect on the concentration of trace elements in the mopane leaves. Seasonal variation in the amount of trace elements has implications on the distribution of browsers in the mopane woodland.     

Label‐free differentiation of human immunodeficiency virus‐1 infected from uninfected cells using transmission measurement

Transmission measurement has been perceived as a potential candidate for label‐free investigation of biological material. It is a real‐time, label‐free and non‐invasive optical detection technique that has found wide applications in pharmaceutical industry as well as the biological and medical fields. Combining transmission measurement with optical trapping has emerged as a powerful tool allowing stable sample trapping, while also facilitating transmittance data analysis. In this study, a near‐infrared laser beam emitting at a wavelength of 1064 nm was used for both optical trapping and transmission measurement investigation of human immunodeficiency virus 1 (HIV‐1) infected and uninfected TZM‐bl cells. The measurements of the transmittance intensity of individual cells in solution were carried out using a home built optical trapping system combined with laser transmission setup using a single beam gradient trap. Transmittance spectral intensity patterns revealed significant differences between the HIV‐1 infected and uninfected cells. This result suggests that the transmittance data analysis technique used in this study has the potential to differentiate between infected and uninfected TZM‐bl cells without the use of labels. The results obtained in this study could pave a way into developing an HIV‐1 label‐free diagnostic tool with possible applications at the point of care .     

Application of Artificial Neural Network for predicting biomass growth during domestic wastewater treatment through a biological process

The biological treatment process is responsible for removing organic and inorganic matter in wastewater. This process relies heavily on microorganisms to successfully remove organic and inorganic matter. The aim of the study was to model biomass growth in the biological treatment process. Multilayer perceptron (MLP) Artificial Neural Network (ANN) algorithm was used to model biomass growth. Three metrics: coefficient of determination (R²), root mean squared error (RMSE), and mean squared error (MSE) were used to evaluate the performance of the model. Sensitivity analysis was applied to confirm variables that have a strong influence on biomass growth. The results of the study showed that MLP ANN algorithm was able to model biomass growth successfully. R² values were 0.844, 0.853, and 0.823 during training, validation, and testing phases, respectively. RMSE values were 0.7476, 1.1641, and 0.7798 during training, validation, and testing phases respectively. MSE values were 0.5589, 1.3551, and 0.6081 during training, validation, and testing phases, respectively. Sensitivity analysis results showed that temperature (47.2%) and dissolved oxygen (DO) concentration (40.2%) were the biggest drivers of biomass growth. Aeration period (4.3%), chemical oxygen demand (COD) concentration (3.2%), and oxygen uptake rate (OUR) (5.1%) contributed minimally. The biomass growth model can be applied at different wastewater treatment plants by different plant managers/operators in order to achieve optimum biomass growth. The optimum biomass growth will improve the removal of organic and inorganic matter in the biological treatment process.     

Laser‐enhanced drug delivery of antiretroviral drugs into human immunodeficiency virus‐1 infected TZMbl cells

The introduction of highly active antiretroviral therapy (HAART) has significantly increased life expectancy and improved management of the human immunodeficiency virus‐1 (HIV‐1) disease globally. This well‐established treatment regime has shown to reduce viral capacity to undetectable limits when using traditional clinical assays. The establishment of viral reservoirs during the early stages of infection are the major contributors to failure of the current regimens to eradicate HIV‐1 infection since the reservoirs are not affected by antiretroviral drugs (ARVs). Therefore, advanced modification of the present treatment and investigation of novel antiretroviral drug delivery system are needed. The aim of this study was to use femtosecond (fs) laser pulses to deliver ARVs into HIV‐1 infected TZMbl cells. Different ARVs were translocated into TZMbl cells using fs pulsed laser (800 nm) with optimum power of 4 μW and 10 ms laser to cell exposure time. Changes in cellular processes were evaluated using cellular morphology, viability, cytotoxicity and luciferase activity assays. Cells treated with the laser in the presence of ARVs showed a significant reduction in viral infectivity, cell viability and an increase in cytotoxicity. This study demonstrated that fs laser pulses were highly effective in delivering ARVs into HIV‐1 infected TZMbl cells, causing a significant reduction in HIV‐1 infection.     

Effects of pruning on the concentration of macronutrients in Colophospermum mopane leaves

Despite the nutritional value of Colophospermum mopane leaves to browser's diets, there is limited knowledge on the effect of browsers on the concentration of macronutrients in mopane leaves. A field experiment was conducted in Musina Nature Reserve, Limpopo Province, South Africa to determine the effect of pruning, a proxy for browsing, on the concentration of macronutrients in mopane leaves. Samples were analysed for calcium (Ca), potassium (K), nitrogen (N), phosphorus (P), sulphur (S), chlorine (Cl), magnesium (Mg), nitrate (NO₃), sodium (Na), protein and fibre, using inductively coupled plasma atomic emission spectrometry techniques. The effect of pruning on the monthly concentration of macronutrients was tested using a two‐tailed t test: two‐sample assuming equal variance. The seasonal and annual effect of pruning on the concentration of macronutrients was tested using a one‐way ANOVA. Results showed that the amount of Ca, K, N, P, S, Cl, Na, protein and fibre increased during leaf flush in October and then declined as the leaves matured and aged. However, the concentration of Mg and NO₃ increased when the leaves reached maturity in June, particularly during senescence stage, and declined thereafter. The concentration of macronutrients between the control and pruned trees was statistically insignificant for most samples.     

Factors Associated with Increased Mortality in a Predominantly HIV-Infected Population with Stevens Johnson Syndrome and Toxic Epidermal Necrolysis

Introduction

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening drug reactions with a higher incidence in HIV-infected persons. SJS/TEN are associated with skin and mucosal failure, predisposing to systemic bacterial infection (BSI), a major cause of death. There are limited data on risk factors associated with BSI and and mortality in HIV-infected people with SJS/TEN.

Methods

We conducted a retrospective study of patients admitted to a university hospital with SJS/TEN over a 3 year period. We evaluated their underlying illnesses, eliciting drugs, predictive value of bacterial skin cultures and other factors associated with mortality and BSI in a predominantly HIV-infected population by comparing characteristics of the patients who demised and those who survived.

Results

We admitted 86 cases during the study period and 67/86(78%) were HIV-infected. Tuberculosis was the commonest co-morbidity, diagnosed in 12/86(14%) cases. Skin cultures correlated with BSI by the same organism in 7/64(11%) cases and 6/7 were Gram-negative. Two of the 8 cases of Gram-negative BSI had an associated Gram-negative skin culture, although not always the same organism. All 8 fatalities had >30% epidermal detachment, 7 were HIV-infected, 6 died of BSI and 6 had tuberculosis.

Conclusions

Having >30% epidermal detachment in SJS/TEN carries an increased risk of BSI and mortality. Tuberculosis and BSI are associated with higher risk of death in SJS/TEN. Our data suggests there may be an association between Gram-negative BSI and Gram-negative skin infection.     

Exploring optical spectroscopic techniques and nanomaterials for virus detection

Viral infections pose significant health challenges globally by affecting millions of people worldwide and consequently resulting in a negative impact on both socioeconomic development and health. Corona virus disease 2019 (COVID-19) is a clear example of how a virus can have a global impact in the society and has demonstrated the limitations of detection and diagnostic capabilities globally. Another virus which has posed serious threats to world health is the human immunodeficiency virus (HIV) which is a lentivirus of the retroviridae family responsible for causing acquired immunodeficiency syndrome (AIDS). Even though there has been a significant progress in the HIV biosensing over the past years, there is still a great need for the development of point of care (POC) biosensors that are affordable, robust, portable, easy to use and sensitive enough to provide accurate results to enable clinical decision making. The aim of this study was to present a proof of concept for detecting HIV-1 pseudoviruses by using anti-HIV1 gp41 antibodies as capturing antibodies. In our study, glass substrates were treated with a uniform layer of silane in order to immobilize HIV gp41 antibodies on their surfaces. Thereafter, the HIV pseudovirus was added to the treated substrates followed by addition of anti-HIV gp41 antibodies conjugated to selenium nanoparticle (SeNPs) and gold nanoclusters (AuNCs). The conjugation of SeNPs and AuNCs to anti-HIV gp41 antibodies was characterized using UV–vis spectroscopy, transmission electron microscopy (TEM) and zeta potential while the surface morphology was characterized by fluorescence microscopy, atomic force microscopy (AFM) and Raman spectroscopy. The UV–vis and zeta potential results showed that there was successful conjugation of SeNPs and AuNCs to anti-HIV gp41 antibodies and fluorescence microscopy showed that antibodies immobilized on glass substrates were able to capture intact HIV pseudoviruses. Furthermore, AFM also confirmed the capturing HIV pseudoviruses and we were able to differentiate between substrates with and without the HIV pseudoviruses. Raman spectroscopy confirmed the presence of biomolecules related to HIV and therefore this system has potential in HIV biosensing applications.