Local migration quantification method for scratch assays

The scratch assay is an in vitro technique used to assess the contribution of molecular and cellular mechanisms to cell migration. The assay can also be used to evaluate therapeutic compounds before clinical use. Current quantification methods of scratch assays deal poorly with irregular cell-free areas and crooked leading edges which are features typically present in the experimental data. We introduce a new migration quantification method, called 'monolayer edge velocimetry', that permits analysis of low-quality experimental data and better statistical classification of migration rates than standard quantification methods. The new method relies on quantifying the horizontal component of the cell monolayer velocity across the leading edge. By performing a classification test on in silico data, we show that the method exhibits significantly lower statistical errors than standard methods. When applied to in vitro data, our method outperforms standard methods by detecting differences in the migration rates between different cell groups that the other methods could not detect. Application of this new method will enable quantification of migration rates from in vitro scratch assay data that cannot be analysed using existing methods

SARS-CoV-2 infection in beta thalassemia: Preliminary data from the Italian experience

Patients with pre\u2010existent chronic morbidities are likely to be more severely affected by SARS\u2010Cov2 infection, but no data are available regarding Thalassemic Syndromes (TS). Note, TS and hemoglobin variants represent, according to WHO, one of the most frequent causes of anemia, affecting more than 7% of the world population.1 Thalassemic Syndromes are classified in either transfusion\u2010dependent thalassemia (TDT) or non\u2010transfusion\u2010dependent thalassemia (NTDT). Infectious complications, mainly from bacteria, constitute a common cause of mortality and morbidity in TS. Stress erythropoiesis, iron overload, splenectomy and adrenal insufficiency among others may contribute to increase susceptibility to infection.2 To verify the impact of SARS\u2010CoV\u20102 infection on TS, we set\u2010up a specific survey by electronic Case Report Form (eCRF).3 Inclusion criteria require at least 15\u2009days of follow\u2010up from either the onset of symptoms or SARS\u2010CoV2 positivity. The survey was approved by Ethics Committee and eCRF was shared with the Centers of Italian Hemoglobinopathies Network. The \u201cSociet\ue0 Italiana Talassemie ed Emoglobinopatie\u201d (SITE), has estimated the presence in Italy of approximately 5000 TDT and 1900 NTDT patients.3 As of 10 April 2020, 11 cases of TS and COVID\u201019 have been collected (see supplementary information). All the reported patients are in Northern Italy, where the rate of infection is higher, reflecting the national epidemiology. The mean age is 44\u2009\ub1\u200911\u2009years (range 31\u201061\u2009years) and 55% (6/11) are females. Ten patients are TDT, and one is NTDT. All the patients have thalassemia associated comorbidities, eight are splenectomized, and one patient (#9 in the supplementary table) has pulmonary hypertension treated with sildenafil. The likely source of infection has been detected in 55% (6/11) of cases: two had contacts with COVID\u201019 positive subjects, and four had occupational exposure (three are nurses working in hospital or assisted living facilities). Three patients were asymptomatic. One patient (#3 in supplementary information) was admitted for high fever and bone marrow hypoplasia, lymphopenia, and agranulocytosis (on treatment with deferiprone) and tested positive at the third swab. Six out of 11 were hospitalized, but no one required mechanical ventilation. The patient with more severe symptoms who required more intensive ventilation support with continuous positive airway pressure (CPAP) has a history of diffuse large B\u2010cell lymphoma, treated with chemotherapy in the previous year, currently in complete remission. Of the six people admitted to the hospital, only three received supposedly specific treatment for COVID\u201019: one hydroxychloroquine (HCQ), one HCQ plus ritonavir/darunavir, and one HCQ plus anakinra. Patient #3 did not receive HCQ due to concomitant therapy with amiodarone and an increased risk of life\u2010threatening arrhythmia. The clinical course ranged from 10 to 29\u2009days. Ten patients have clinically recovered and are on a daily remote phone call follow\u2010up. Splenectomy which was present in 8/11 patients did not seem to affect the clinical course. Of note, except for the patient with myelosuppression, no increase in blood requirement was observed. When luspatercept treatment was halted in the NTDT patient, hemoglobin fell from 110 to 82 g/L, a value similar to the pre\u2010luspatercept period. Neither death nor severe SARS or signs of cytokines storm were observed in these 11 subjects, which may be surprising, taking into account the mean age and the presence of severe comorbidities. Our data, although preliminary, do not indicate increased severity of COVID\u201019 in TS. A larger number of cases needs to be collected to define the impact of this new infection and its outcome in these fragile patients

Pregnancy and Fetal Outcomes After Exposure to Mefloquine in the Pre- and Periconception Period and During Pregnancy

Pregnant women who travel to malarious areas and their clinicians need data on the safety of malaria chemoprophylaxis. The drug safety database analysis of mefloquine exposure in pregnancy showed that the birth defect prevalence and fetal loss in maternal, prospectively-monitored cases were comparable to background rates

A Two-Dimensional Electron Gas as a Sensitive Detector for Time-Resolved Tunneling Measurements on Self-Assembled Quantum Dots

A two-dimensional electron gas (2DEG) situated nearby a single layer of self-assembled quantum dots (QDs) in an inverted high electron mobility transistor (HEMT) structure is used as a detector for time-resolved tunneling measurements. We demonstrate a strong influence of charged QDs on the conductance of the 2DEG which allows us to probe the tunneling dynamics between the 2DEG and the QDs time resolved. Measurements of hysteresis curves with different sweep times and real-time conductance measurements in combination with an boxcar-like evaluation method enables us to unambiguously identify the transients as tunneling events between the s- and p-electron QD states and the 2DEG and rule out defect-related transients

Italian patients with hemoglobinopathies exhibit a 5-fold increase in age-standardized lethality due to SARS-CoV-2 infection.

Since the beginning of the COVID-19 pandemic, concerns have been expressed worldwide for patients with hemoglobinopathies and their vulnerability to SARS-CoV-2 infection. Data from Lebanon confirmed a role of underlying comorbidities on COVID-19 severity, but no deaths among a cohort of thalassemia patients.1 Patients with sickle cell disease (SCD) displayed a broad range of severity after SARS-CoV-2 infection, spanning from a favorable outcome unless pre-existing comorbidities (UK cohort)2 to high case mortality in US.3 History of pain, heart, lung, and renal comorbidities was identified as risk factors of worse COVID-19 outcomes by the US SECURE-SCD Registry.4 While Italy experienced a death rate in the general population among the highest in the world, preliminary data from the first wave of the pandemic showed a lower than expected number of infected thalassemia patients (updated up to April 10, 2020), likely due to earlier and more vigilant self-isolation compared to the general population.