Introduction: Prolactin (PRL) exists in different forms in human serum. The predominant form is monomeric PRL (molecular mass 23 kDa) with smaller amounts of big PRL (molecular mass 50–60 kDa) and at times macroprolactin (molecular mass 150–170 kDa). Macroprolactin, generally considered to be biologically inactive, accounts for the major part of prolactin in some patients. Different immunoassays for prolactin differ in reactivity with this macromolecular complex. Aim: The present study was undertaken to assess the incidence of macroprolactinaemia in our cohort of hyperprolactinemic patients. Method: 204 samples with hyperprolactinemia were evaluated for macroprolactinemia by polyethylene glycol (PEG) precipitation and gel fi ltration chromatography (GFC). Recoveries <60% after PEG precipitation were considered to have macroprolactinaemia. Results: A total of 43 (21%) of these patients had less than 60% recovery after PEG precipitation. GFC confi rmed that in seven of these patients macroprolactin was the major part of the prolactin. Recoveries were < 40% PEG precipitation in these samples. Combined macro and hyperprolactinemia was observed in two samples and the recovery after PEG precipitation was >40% but 50%. The incidence of macroprolactinemia in our cohort of hyperprolactinaemic patients was noted to be 4.4%. Conclusion: Macroprolactin is a signifi cant cause of misdiagnosis, unnecessary investigation, and inappropriate treatment and hence it is useful to screen all patients with high PRL levels with PEG precipitation and to apply GFC to samples with recoveries <50%.

Aims: New therapeutics are needed to ease the prevailing waterborne disease, and one of the alternatives is by exploring the natural compounds with antimicrobial properties. Duckweed, Lemna sp. is recorded as a medicinal herb that known to have antifungal and antibacterial activities towards several fungi and bacteria. Suitability of duckweed (Lemna minor) as an antibacterial resource against selected waterborne bacteria were evaluated in terms of its antibacterial activity and toxicity. Methodology and results: Antibacterial activity of the duckweed methanolic extract was tested against 11 selected waterborne bacteria using disc diffusion, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) assay. Brine shrimp lethality assay was used to determine the toxicity of this extract. The lethal concentrations of plant extract resulting in 50% mortality of the brine shrimp (LC50) were then determined. Conclusion, significance and impact of study Results showed that duckweed extract exhibited bacteriostatic and bactericidal against the selected bacteria activity at the concentration of MIC = 1.8-2.0 mg/mL and MBC ≥ 2.0 mg/mL. This study shows that methanolic extract of L. minor may contain bioactive compounds against bacteria and potential therapeutic effect. The crude extract is slightly toxic and may not safe to be used in high concentration but is valuable in further study as a potential antitumor agent.

INTRODUCTION: Chest radiographs (CXRs) are widely used for the screening and management of COVID-19. This article describes the radiographic features of COVID-19 based on an initial national cohort of patients. METHODS: This is a retrospective review of swab-positive patients with COVID-19 who were admitted to four different hospitals in Singapore between 22 January and 9 March 2020. Initial and follow-up CXRs were reviewed by three experienced radiologists to identify the predominant pattern and distribution of lung parenchymal abnormalities. RESULTS: In total, 347 CXRs of 96 patients were reviewed. Initial CXRs were abnormal in 41 (42.7%) out of 96 patients. The mean time from onset of symptoms to CXR abnormality was 5.3 ± 4.7 days. The predominant pattern of lung abnormality was ground-glass opacity on initial CXRs (51.2%) and consolidation on follow-up CXRs (51.0%). Multifocal bilateral abnormalities in mixed central and peripheral distribution were observed in 63.4% and 59.2% of abnormal initial and follow-up CXRs, respectively. The lower zones were involved in 90.2% of initial CXRs and 93.9% of follow-up CXRs. CONCLUSION In a cohort of swab-positive patients, including those identified from contact tracing, we found a lower incidence of CXR abnormalities than was previously reported. The most common pattern was ground-glass opacity or consolidation, but mixed central and peripheral involvement was more common than peripheral involvement alone.
COVID-19 ; Humans ; Lung/diagnostic imaging* ; Radiography, Thoracic ; Retrospective Studies ; SARS-CoV-2 ; Singapore