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Background: Studies from Asia, Europe and the USA indicate that widely available haematological parameters could be used to determine the clinical severity of Coronavirus disease 2019 (COVID-19) and predict management outcome. There is limited data from Africa on their usefulness in patients admitted to Intensive Care Units (ICUs). We performed an evaluation of baseline haematological parameters as prognostic biomarkers in ICU COVID-19 patients. Methods: Demographic, clinical and laboratory data were collected prospectively on patients with confirmed COVID-19, admitted to the adult ICU in a tertiary hospital in Cape Town, South Africa, between March 2020 and February 2021. Robust Poisson regression methods and receiver operating characteristic (ROC) curves were used to explore the association of haematological parameters with COVID-19 severity and mortality. Results: A total of 490 patients (median age 54.1 years) were included, of whom 237 (48%) were female. The median duration of ICU stay was 6 days and 309/490 (63%) patients died. Raised neutrophil count and neutrophil/lymphocyte ratio (NLR) were associated with worse outcome. Independent risk factors associated with mortality were age (ARR 1.01, 95%CI 1.0–1.02; p = 0.002); female sex (ARR 1.23, 95%CI 1.05–1.42; p = 0.008) and D-dimer levels (ARR 1.01, 95%CI 1.002–1.03; p = 0.016). Conclusions: Our study showed that raised neutrophil count, NLR and D-dimer at the time of ICU admission were associated with higher mortality. Contrary to what has previously been reported, our study revealed females admitted to the ICU had a higher risk of mortality. [ABSTRACT FROM AUTHOR]

Introduction. Adult T-cell leukaemia/lymphoma (ATLL) is a rare and aggressive malignancy of mature T-cells. Limited epidemiological studies have shown that there is substantial variation in age at diagnosis and subtype distribution between different geographical regions. This is the first epidemiological study of ATLL in South Africa. Methods. A national epidemiological study of ATLL in South Africa was performed. All new cases of ATLL from 2009 to 2019 were identified by laboratory database search in public and private health care sectors. Demographic and diagnostic data were obtained, and the cases were subtyped according to the Shimoyama classification. Results. There were 31 patients with ATLL over the 10-year period, with an incidence of 0.06 per 100000 population. The male to female ratio was 1 : 1 and the median age at diagnosis was 37 years. Acute ATLL was the most commonly seen subtype in South Africa. Conclusion. In this, the first epidemiological study of ATLL in South Africa, we demonstrate that ATLL is a rare disease, that acute ATLL is the most commonly diagnosed subtype, and that ATLL is likely under diagnosed. Patients present at a considerably younger age than the reported age in other nations. [ABSTRACT FROM AUTHOR]

International consortiums, including the COVID-19 HGI, the COVID-19 Human Genetics effort (HGE), and the Genetics Of Mortality In Critical Care (GenOMICC) have promoted the sharing of data to facilitate the inclusion of large study cohorts from multiple populations for ongoing meta-analyses ([7]; [6]; [15]). Keywords: African genomics; genetic susceptibility; SARS-CoV-2 infection variability; COVID-19 severity; COVID-19 genetic associations; limited African data EN African genomics genetic susceptibility SARS-CoV-2 infection variability COVID-19 severity COVID-19 genetic associations limited African data 1 6 6 05/12/22 20220510 NES 220510 Introduction Towards the end of 2019, the world faced the emergence of the Coronavirus Disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). African genomics, genetic susceptibility, SARS-CoV-2 infection variability, COVID-19 genetic associations, limited African data, COVID-19 severity South Africa has not remained unscathed by the pandemic, having more than 3.7 million COVID-19 cases, and nearing close to 100,000 COVID-19 related deaths ([52]) with the introduction of different SARS-CoV-2 variants at various timepoints (Figure 1A). [Extracted from the article]

Background: Coronavirus disease 2019 (COVID‐19) is associated with hematological abnormalities of variable severity. The full blood count (FBC) and leukocyte differential count (DIFF) could facilitate the prediction of disease severity and outcome in COVID‐19. This study aimed to assess the hematological parameters in early severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and their correlation with disease outcome. Methods: A retrospective cross‐sectional descriptive study was performed. Adults with a FBC and positive SARS‐CoV‐2 polymerase chain reaction results between March 1, and June 31, 2020 were reviewed. Basic hematological parameters (FBC, DIFF) and human immunodeficiency virus (HIV) status were recorded. Outcome measures were admission to a general ward or intensive care unit (ICU), recovery or death. Results: Six hundred and eighty‐five cases median age 51 years, were analyzed. Forty‐four percent were males and fourteen percent were HIV‐positive with no association between death and/or ICU admission (p = 0.522 and p = 0.830, respectively). Leucocytosis was predictive of ICU admission (odds ratio [OR]: 2.4, confidence interval [CI]: 1.77–3.8186) and neutrophilia, of both mortality (OR: 1.5, CI: 1.0440–2.0899) and ICU admission (OR: 4, CI: 2.5933–6.475). Median lymphocyte count was decreased and D‐dimer raised, showing no significant association with outcome. Raised neutrophil‐to‐lymphocyte‐ratio (NLR) was associated with increased odds of mortality (OR: 2.5, CI: 1.3556–3.2503) and ICU admission (OR: 4.8, CI: 2.4307–9.5430) as was monocyte‐to‐lymphocyte‐ratio (MLR) (OR: 2, CI: 1.3132–2.9064) and (OR: 2.3, CI: 1.0608–1.9935), respectively. Hospital admission and older age were significantly associated with mortality (p = 0.0008 and p < 0.0001), respectively. Conclusion: Evidence‐based interpretation of routine laboratory parameters, readily available in resource‐constrained settings, may identify patients at increased risk of mortality. The FBC, DIFF, NLR, and MLR should form part of the early COVID‐19 investigation. [ABSTRACT FROM AUTHOR]

Bone marrow examination is a useful diagnostic tool in human immunodeficiency virus (HIV)-positive patients presenting with cytopenias and fever. However, its role in the afebrile and asymptomatic patient presenting with an isolated cytopenia is not well established. This study was conducted to determine the indications for bone marrow examination and its diagnostic yield, in HIV-positive patients at Tygerberg Hospital. A retrospective, cross-sectional descriptive study was performed over a 3-year period from 01 September 2015 to 31 August 2018. The bone marrow examination reports for the HIV-positive patients who had a bone marrow examination during the study period were retrieved. Clinical and laboratory information was captured. Altogether 374 bone marrow reports for HIV-positive patients were found. The indication of the bone marrow examination included investigation of unexplained cytopenias, suspected haematological malignancies, follow-up examination for patients with known haematological diseases, staging of haematological or non-haematological malignancies and investigation of suspected disseminated infection. The patients' median age was 43 years and the interquartile range was 27–60 years. There was a slight female predominance with females 51% and males 49%. The diagnostic yield was 33.7%. Acute leukaemia and lymphoma were the most common diagnoses. Haematinic deficiency and pure red cell aplasia were found in the majority of cases with isolated anaemia. All cases with isolated thrombocytopenia were due to immune thrombocytopenia. Bone marrow examination is a useful investigation for HIV-positive patients with cytopenias, suspected haematological malignancy and lymphoma staging. However, its early use in patients with isolated anaemia and isolated thrombocytopenia is questionable. [ABSTRACT FROM AUTHOR]

Background: Thrombophilia-screen tests are specialised haemostasis tests that are affected by numerous unique patient variables including the presence of acute thrombosis, the concomitant use of medication and patient demographics. Complete information on the request form is therefore crucial for the haematological pathologist to make patient-specific interpretation of patients' results. Objectives: To assess the completeness of thrombophilia-screen test request forms and determine the impact of provision of incomplete information, on the interpretive comments generated by reporting haematological pathologists. To assess the impact of an educational session given to clinicians on the importance of providing all the relevant information on the request forms. Method: Two retrospective audits, each covering 3 months, were performed to evaluate the completeness of demographic and clinical information on thrombophilia-screen request forms and its impact on the quality of the interpretive comments before and after an educational intervention. Results: One hundred and seventy-one request forms were included in the first audit and 146 in the second audit. The first audit revealed that all 171 thrombophilia-screen request forms had complete patient demographic information but none had clinical information. Haematological pathologists only made generic comments which could not be applied to a specific patient. The second audit, conducted after a physician educational session, did not reveal any improvement in the clinical information provision by the test-ordering physicians. This was reportedly due to the lack of space on the request form. The interpretive comments therefore remained generic and not patient-specific. Conclusion: Physicians' failure to provide relevant clinical information made it impossible for pathologists to make patient-specific interpretation of the results. A single physician education session did not change the practice, reportedly due to the inappropriate design of the test request form. Further studies are required to investigate the impact of an improved request form and the planned electronic test requesting. [ABSTRACT FROM AUTHOR]

This case study explores a clinicopathological presentation of Adult T-cell leukaemia/lymphoma (ATLL) at Tygerberg Hospital; a disease associated with adulthood noted in an adolescent patient. Adult T-cell leukaemia-lymphoma oncogenesis develops through a multistep process with an accumulation of mutations. Infection through human T-lymphotropic virus type 1 (HTLV-1) is the first step of a multistep process resulting in eventual clonal proliferation of mature T-cells. There is a long latency period of 20-50 years from the time of infection with HTLV-1 to the development of symptoms of ATLL; thus, ATLL is a malignancy associated with adulthood. The median age of diagnosis is 58, ranging from the third to ninth decade of life. This is an ideal learning case as it highlights the importance of recognising ATLL in children and young adults in our population. [ABSTRACT FROM AUTHOR]

Polymer/ZnO nanocomposites have received a great interest in its linear and nonlinear optical properties because of their potential application such as optical switching and optical limiting devices. In the current work, four polymer/ZnO nanocomposites as a flexible foil have been prepared using casting method. Poly (methyl methacrylate) (PMMA), poly (vinylidene fluoride), polyvinyl alcohol and polystyrene were used as polymer matrices, while ZnO nanoparticles of different concentrations were used as filler. The composition of nanocomposites materials was confirmed by the energy dispersive X-ray (EDX), also a good spatial distribution of elements in the nanocomposites was showed by EDS mapping. The UV-Visible transmittance spectra of as-prepared samples showed low transmittance in the UV region and the peak absorption in the range of 370-377 nm depended on the polymer matrix. The optical absorptive and refractive nonlinearities parameters such as absorption coefficient and refractive index of the as-prepared sample were analyzed using an open and closed aperture single beam Z-scan technique via Q-switched Nd-YAG pulse laser at 532 nm. The nonlinear refractive index was in the order of 10 cm/W with a negative sign whereas the nonlinear absorption coefficient was in the order of 10 cm/W. In order to evaluate the suitability of the samples as optical limiting, the optical limiting threshold of the samples was measured by using transmittance technique. The results showed that the prepared nanocomposites can be considered as an excellent candidate for optical limiting devices. PMMA/ZnO with high concentration of ZnO nanoparticles showed low optical limiting threshold, which was equal to 70 Mw/cm. [ABSTRACT FROM AUTHOR]

Polymers/ZnO nanocomposites have been receiving great interest due to their wide range of applications in optical devices. So, there is an essential need to enhance their optical properties. In this work, nanocomposites of four types of polymer and ZnO nanoparticles have been prepared as flexiable foil by using the casting method. Poly (methyl methacrylate) (PMMA), poly (vinylidene fluoride) (PVDF), polyvinyl alcohol (PVA), and polystyrene (PS) are used as polymer matrix while different concentrations of ZnO nanoparticles are used as filler. The analysis of energy dispersive X-ray (EDX) is satisfied of the high purity of as-prepared samples. UV-visible transmittance spectra have shown low transmittance in UV region which is inversely proportional with the concentration of ZnO nanoparticles. Linear absorption coefficient (α) has shown the presence of absorption edges. The energy gap is calculated, it is noticed that the optical band gap of all nanocomposites are red shifted. The values of the energy gap for all samples decreased with the increase of the weight percentage of ZnO nanoparticles in nanocomposites. However, the decrement in nanocomposites samples is different. [ABSTRACT FROM AUTHOR]

The effect of substrate on the crystalline phase and morphology of the poly (vinylidene fluoride) (PVDF) thin film has been investigated. The solution of PVDF/Hexamethyl phosphoramide (HMPA) was deposited on four different substrates, namely, silicon (Si), glass (SiO2), indium tin oxide (ITO) coated glass and silver (Ag) coated glass respectively by using the spin coating technique. The crystalline structure was investigated using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. The morphology was determined using scanning electron microscopy (SEM). XRD demonstrated that the structure of PVDF thin films on each substrate is -phase with different orientations of the molecular chains. FTIR results confirmed XRD that the samples contain -phase. SEM shows spherulites structure, which is rough and porous, besides, the size of spherulites and the porosity are different for each sample. The size of spherulites is in average diameter range (1-6m) and this range is attributed to the -phase. The nucleation process of -phase on the various substrates attributed either to the match of polymer-substrate or to the electrostatic interaction. Among the substrates used, the ITO substrate exhibited a greater tendency for -phase formation. [ABSTRACT FROM AUTHOR]

Competing Interests: The authors declare no conflict of interest.