cAMP-Signalling Regulates Gametocyte-Infected Erythrocyte Deformability Required for Malaria Parasite Transmission.

Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination. Transmission is ensured by gametocyte-infected erythrocytes (GIE) that sequester in the bone marrow and at maturation are released into peripheral blood from where they are taken up during a mosquito blood meal. Release into the blood circulation is accompanied by an increase in GIE deformability that allows them to pass through the spleen. Here, we used a microsphere matrix to mimic splenic filtration and investigated the role of cAMP-signalling in regulating GIE deformability. We demonstrated that mature GIE deformability is dependent on reduced cAMP-signalling and on increased phosphodiesterase expression in stage V gametocytes, and that parasite cAMP-dependent kinase activity contributes to the stiffness of immature gametocytes. Importantly, pharmacological agents that raise cAMP levels in transmissible stage V gametocytes render them less deformable and hence less likely to circulate through the spleen. Therefore, phosphodiesterase inhibitors that raise cAMP levels in P. falciparum infected erythrocytes, such as sildenafil, represent new candidate drugs to block transmission of malaria parasites

Differentiation of Bacillus pumilus and Bacillus safensis using MALDI-TOF-MS

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) despite being increasingly used as a method for microbial identification, still present limitations in which concerns the differentiation of closely related species. Bacillus pumillus and Bacillus safensis, are species of biotechnological and pharmaceutical significance, difficult to differentiate by conventional methodologies. In this study, using a well-characterized collection of B. pumillus and B. safensis isolates, we demonstrated the suitability of MALDI-TOF-MS combined with chemometrics to accurately and rapidly identify them. Moreover, characteristic species-specific ion masses were tentatively assigned, using UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases and primary literature. Delineation of B. pumilus (ions at m/z 5271 and 6122) and B. safensis (ions at m/z 5288, 5568 and 6413) species were supported by a congruent characteristic protein pattern. Moreover, using a chemometric approach, the score plot created by partial least square discriminant analysis (PLSDA) of mass spectra demonstrated the presence of two individualized clusters, each one enclosing isolates belonging to a species-specific spectral group. The generated pool of species-specific proteins comprised mostly ribosomal and SASPs proteins. Therefore, in B. pumilus the specific ion at m/z 5271 was associated with a small acid-soluble spore protein (SASP O) or with 50S protein L35, whereas in B. safensis specific ions at m/z 5288 and 5568 were associated with SASP J and P, respectively, and an ion at m/z 6413 with 50S protein L32. Thus, the resulting unique protein profile combined with chemometric analysis, proved to be valuable tools for B. pumilus and B. safensis discrimination, allowing their reliable, reproducible and rapid identification.Dr. Kasthuri Venkateswaran, Dr. Irene Ouoba, Dr. Joseph W. Kloepper, Dr. Cecilie From and Dr. Maria Morea are gratefully acknowledged for providing isolates FO-36bT, SAFN-027, SAFN-037, KL-052, 51-3C and 82-2C; Bs31; SE 49 (AP3) and SE 52 (AP7); FEL 55, UNG22 and MIL46, respectively. Raquel Branquinho was supported by a PhD fellowship (Ref. SFRH/BD/61410/2009) and Clara Sousa by a post-doctoral fellowship (Ref. SFRH/BPD/70548/2010), from FCT (Fundacao para a Ciencia e Tecnologia, Portugal). Hugo Osorio acknowledges the funding from QREN-FEDER through the Operational Program ON. 2 - O Novo Norte. IPATIMUP is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education and is partially supported by the Portuguese Foundation for Science and Technology. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competin

Performance Evaluation Of Vertical Wells For Landfill Leachate Recirculation

A vertical leachate recirculation system was evaluated for its potential to recirculate leachate into landfilled waste. Leachate was recirculated through eleven vertical wells installed at three different depths. The results of recirculation tests performed over a 6-month duration are presented in this paper. The results indicated that specific capacity of vertical wells decreased with well depth. The specific capacity per unit screen length of the vertical wells ranged from 1.2×10-6 to 1.2×10-5 m 3/s-m2. The mean specific capacity of lines installed at three different depths were significantly (p\u3c0.025) different from each other and were in the following order: shallow well (depth ∼6 to 8 m) \u3e middle well (depth∼12 to 16 m) \u3e deep well (depth∼18 m). A potential reason for lower specific capacity for deep wells is the lower hydraulic conductivity of the waste in deeper sections due to higher overburden pressure. While the data presented in this paper are based on preliminary injection tests and may not represent steady-state condition, the results provide important insight into the hydrodynamic behavior of bioreactors

SARS-CoV-2 viability and viral RNA persistence on microbiological agar plates

International audienc

How much time do we have? Longitudinal perception of prognosis in newly-diagnosed high grade glioma patients and caregivers compared to clinicians.

PURPOSE: Discordant prognostic awareness (PA) can cause distress, impact goals of care and future planning, especially in patients with high grade glioma (pwHGG) who have limited survival. We aimed to evaluate the feasibility of assessing PA of pwHGG, caregivers and clinicians using a single question and to evaluate these responses for discord, alignment and fluctuation over time. METHODS: This is a sub-study of an IRB-approved pilot study evaluating early palliative care and longitudinal symptom monitoring via a smart-device tool in 16 pwHGG and their caregivers receiving treatment at the Mayo Clinic Arizona (United States). Eligible patients were ≥ 18 years, English-speaking, newly-diagnosed, and had a willing caregiver. Participants answered a multiple-choice question asking for an estimate of their own or their loved one\u27s survival on a monthly basis. RESULTS: All except one patient/caregiver dyad answered the question each time it was asked. The question did not appear to cause discomfort or increase conversations with clinicians around prognosis. PA of patients and caregivers fluctuated monthly, ranging from dismal to overtly optimistic, with a discordance frequency of 68%. Patients tended to be more optimistic than caregivers, and a higher QOL correlated to a more optimistic response. Clinicians\u27 were more hopeful; their prediction tended to fluctuate less than those of patients and caregivers. CONCLUSIONS: PA may be assessed in pwHGG and caregivers with a single, frank question. There is clear discordance between PA of patients, their caregivers and clinicians. Understanding fluctuates longitudinally through disease and treatment course. Additional studies on timing and ways of discussing prognosis in this population are needed. CLINICAL TRIAL REGISTRATION: NCT04630379