Rapid screening of COVID-19 patients using white blood cell scattergrams, a study on 381 patients.

Complementary tools are warranted to increase the sensitivity of the initial testing for COVID-19. We identified a specific 'sandglass' aspect on the white blood cell scattergram of COVID-19 patients reflecting the presence of circulating plasmacytoid lymphocytes. Patients were dichotomized as COVID-19-positive or -negative based on reverse transcriptase polymerase chain reaction (RT-PCR) and chest computed tomography (CT) scan results. Sensitivity and specificity of the 'sandglass' aspect were 85·9% and 83·5% respectively. The positive predictive value was 94·3%. Our findings provide a non-invasive and simple tool to quickly categorize symptomatic patients as either COVID-19-probable or -improbable especially when RT-PCR and/or chest CT are not rapidly available.

Glycine and ammonia plasma concentrations during sedation with remifentanil in critically ill patients.

OBJECTIVES: To investigate glycine and ammonia plasma concentrations during a 72-h remifentanil infusion and the relationship between glycine concentration and remifentanil infusion rate. DESIGN AND SETTING: A prospective open-label observational clinical trial in a trauma and a neurosurgical intensive care unit in a university teaching hospital. PATIENTS: Nine consecutive patients requiring sedation and ventilatory support for at least 72 h. One was excluded due to acute cardiac failure. INTERVENTIONS: Patients were sedated with remifentanil and propofol. Glycine and ammonia plasma concentrations were measured every 12 h during an intravenous remifentanil infusion performed over 72 h, and 24 h after the end of the infusion. Cumulative remifentanil dose and rate of infusion were recorded for each patient. Clinical and biological signs of glycine toxicity were evaluated. MEASUREMENTS AND RESULTS: Glycine and ammonia plasma concentrations did not exceed the toxic threshold at any time. Plasma glycine concentration measured at the end of remifentanil infusion was significantly correlated with the mean weighted rate of remifentanil infusion and with the cumulative remifentanil dose. A correlation between plasma glycine concentration and creatinine clearance at the end of remifentanil infusion was also documented. CONCLUSIONS: Plasma glycine concentration was correlated with the remifentanil cumulative dose and the infusion rate and did not reach the toxic threshold. As glycine concentration was also correlated with creatinine clearance and because remifentanil was the only source of exogenous glycine, additional data are necessary to ascertain the safety of remifentanil infusion in ICU patients.

A novel mutation in the human complex I NDUFS7 subunit associated with Leigh syndrome.

Defects in NADH:ubiquinone oxidoreductase, the complex I of the mitochondrial respiratory chain represents the most frequent cause of mitochondrial diseases and is associated with a wide clinical spectrum varying from severe lactic acidosis in infants to muscle weakness in adults. Here, we report a patient with Leigh syndrome (LS), born to consanguineous parents, with severe complex I defect and a novel mutation in the NDUFS7 gene subunit. The homozygous mutation at nucleotide (nt) 434 G>A resulted in the modification of the arginine 145 to histidine in a highly conserved region of the protein. Parents were heterozygous carriers for this mutation. The mutation was absent from over than 100 healthy controls from the same ethnic origin. Identifying nuclear mutations as a cause of respiratory chain disorders will enhance the possibility of prenatal diagnosis and help us to understand how moleculardefects can lead to complex I deficiency.