COVID-19 convalescent plasma: current status,lessons from the past and future perspectives

When the COVID-19 pandemic hit, blood transfusion services worldwide started collection of convalescent plasma as early as possible, as exemplified by the response in Norway. There were challenges related to donor selection, donor safety, testing for relevant antibodies and indications for and dosing of the convalescent plasma. As more knowledge became available, the product quality was more standardised. Multiple case reports, observational studies and some randomized studies were published during the pandemic, as well as laboratory studies reporting different approaches to antibody testing. The results were conflicting and the importance of convalescent plasma was disputed.Even though there has been strong international collaboration with involvement of many key organisations, we may better prepare for the next pandemic. An even stronger, more formalised collaboration between these organisations could provide more clear evidence of the importance of convalescent plasma, based on the principles of passive immunisation.     

A Coupled FEM-BEM Approach for the Solution of the Free-Boundary Axi-Symmetric Plasma Equilibrium Problem

In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric plasma equilibrium problem. The proposed method, obtained from an improvement of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium problem in unbounded domains by discretizing only the plasma region; the external conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github. om/matteobonotto/ FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against experimental data from RFX-mod device, and numerical equilibria of an ITER-like device.     

Plasmacytic cutaneous pathology: A review

We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field.     

Collecting and evaluating convalescent plasma for COVID-19 treatment: why and how?

Plasma provided by COVID-19 convalescent patients may provide therapeutic relief as the number of COVID-19 cases escalates steeply worldwide. Prior findings in various viral respiratory diseases including SARS-CoV-related pneumonia suggest that convalescent plasma can reduce mortality, although formal proof of efficacy is still lacking. By reducing viral spread early on, such an approach may possibly downplay subsequent immunopathology. Identifying, collecting, qualifying and preparing plasma from convalescent patients with adequate SARS-CoV-2-neutralizing Ab titres in an acute crisis setting may be challenging, although well within the remit of most blood establishments. Careful clinical evaluation should allow to quickly establish whether such passive immunotherapy, administered at early phases of the disease in patients at high risk of deleterious evolution, may reduce the frequency of patient deterioration, and thereby COVID-19 mortality.     

蒜氨酸抗菌机制研究

目的 检测蒜氨酸最低抑菌浓度（MIC）与最低杀菌浓度（MBC），探讨蒜氨酸体内外抗菌机制。方法 体外微量稀释法检测蒜氨酸MIC和MBC，荧光显微镜观察菌体表面蒜氨酸，探讨蒜氨酸抗菌机制。体内蒜氨酸和青霉素分别治疗金葡菌感染家兔脓肿，检测脓汁标本中细菌存活情况，探讨体内蒜氨酸抗菌作用。结果 蒜氨酸对大肠杆菌、伤寒杆菌、金黄色葡萄球菌、白色葡萄球菌的MIC分别为3.047 μg·mL^-1、6.094 μg·mL^-1、0.386 μg·mL^-1、0.386 μg·mL^-1，蒜氨酸体外无杀菌活性。浓汁标本：死菌率蒜氨酸治疗组显著高于阴性对照组（P < 0.01），与青霉素治疗组无明显差异（P > 0.05）；活菌率蒜氨酸治疗组显著低于阴性对照组（P < 0.01），与青霉素治疗组无明显差异（P > 0.05）。结论 蒜氨酸与菌体蛋白、细菌酶蛋白结合阻断细菌与环境物质交换，抑制细菌生命活动，具有较强的抑菌作用，无杀菌活性；蒜氨酸体内代谢成大蒜素，具有较强杀菌作用。