Impact of COVID‐19 on access to healthcare in low‐ and middle‐income countries: Current evidence and future recommendations

The COVID‐19 pandemic continues to be a major public health threat globally and low‐ and middle‐income countries (LMICs) are not an exception. The impact of the COVID‐19 pandemic is far‐reaching on many areas including but not limited to global health security, economic and healthcare delivery with a potential impact on access to healthcare in LMICs. We evaluate the impact of the COVID‐19 pandemic on access to healthcare in LMICs, as well as plausible strategies that can be put in place to ensure that the delivery of healthcare is not halted. In order to mitigate the devastating effect of the COVID‐19 pandemic on the already weak health systems in LMICs, it is much necessary to reinforce and scale up interventions and proactive measures that will ensure that access to healthcare is not disrupted even in course of the pandemic.     

Cryptococcus neoformans capsule structure evolution in vitro and during murine infection

Cryptococcus neoformans capsule structure modifications after prolonged in vitro growth or in vivo passaging have been reported previously. However, nothing is known about the dynamics of these modifications or about their environmental specificities. In this study, capsule structure modifications after mouse passaging and prolonged in vitro culturing were analyzed by flow cytometry using the glucuronoxylomannan-specific monoclonal antibody E1. The capsule structures of strains recovered after 0, 1, 8, and 35 days were compared by using the level of E1-specific epitope expression and its cell-to-cell heterogeneity within a given cell population. In vitro, according to these parameters, the diversity of the strains was higher on day 35 than it was initially, suggesting the absence of selection during in vitro culturing. In contrast, the diversity of the strains recovered from the brain tended to decrease over time, suggesting that selection of more adapted strains had occurred. The strains recovered on day 35 from the spleen and the lungs had different phenotypes than the strains isolated from the brain of the same mouse on the same day, thus strongly suggesting that there is organ specificity for C. neoformans strain selection. Fingerprinting of the strains recovered in vitro and in vivo over time confirmed that genotypes evolved very differently in vitro and in vivo, depending on the environment. Overall, our results suggest that organ-specific selection can occur during cryptococcosis.     

Human platelets after their contact with influenza virus activate the complement system in autologous serum

Guinea pig erythrocytes that have been exposed to influenza virus activate the alternative pathway through virus-induced desialation of the cells. Neuraminidase treatment of rabbit platelets enhance their clearancein vivo. Washed human platelets were labeled with⁵¹Cr exposed to Influenza virus, and resuspended in autologous serum that had been dialyzed against Veronal-buffered saline containing Ca⁺⁺ and Mg⁺⁺ (VBS⁺⁺), VBS containing 8 mM EGTA and 2 mM Mg⁺⁺ (VBS-MgEGTA) or VBS containing 20 mM EDTA (VBS-EDTA) for 60 min at 37°C. Three per cent⁵¹Cr release and no complement consumption were observed in VBS-EDTA serum. In contrast, 6%⁵¹Cr release with 37 and 54% decrease in C3 and B hemolytic activities respectively occurred in VBS-MgEGTA serum and 14%⁵¹Cr release with 50% decrease in C2 hemolytic activity occurred in VBS⁺⁺ serum. These results suggest that influenza virus may alter the platelet surface in such a way that both complement pathways might be recruited and the cells be lyzed in autologous serum.The human complement system is activated by a number of viruses and virus-infected cells through antibody-dependent and independent mechanisms. Guinea pig erythrocytes that have been treated with influenza virus are lyzed in human serum through activation of the classical and of the alternative pathways: activation of the alternative pathway is dependent on an acquired resistance of the cell-bound C3 amplification convertase to control mechanisms that are directly related to desialation of the cells by viral neuraminidase [1]. Since,in vivo, clearance of desialated platelets is enhanced in animal models and since human platelets do not express the C3b receptor-associated inhibitory activity of the complement system, we investigated whether human platelets, after contact with influenza virus, acquire the ability to activate complement in autologous serum.     

Role of x-ray computed tomography in the preoperative evaluation of aneurysm of the abdominal aorta

The authors have studied the files of 50 consecutive patients (1987-89) operated for abdominal aortic aneurysm (AAA) and examined with CT. The criteria for inclusion were surgical features. CT can be made more accurate for the study of AAA: Thus the location of the neck of the aneurysm relative to the renal arteries was defined in 94% of all cases. In addition, CT yields information about the wall of the aneurysm, whether it be thickened (3 inflammatory aneurysms were properly diagnosed) or, mor importantly, weakened (solution of continuity in the wall in the "prior-to-rupture" appearance). Owing to the quality of its performances and to its noninvasive character, the authors regard CT with contrast injection as an essential technique for the preoperative assessment of abdominal aortic aneurysm in most cases. The examination must be carried out strictly, especially for the contiguous sections of the renal arteries and their extension to the crural arch. As it demonstrates weakened areas more easily, a more accurate study of the aneurysmal wall with CT might increase the surgical indications for some smaller aneurysms, the potential evolution of which does not seem to be associated with their diameter only.     

Effect of brain and spinal cord injuries on motor imagery

Summary The timing of mentally executed movements was measured in ten patients with hemiplegia, tetraplegia and paraplegia. In hemiplegic patients a significant difference in mental duration times was found between the paralysed and the normal represented limb. The paralysed limb was mentally much slower than the healthy one. In contrast, movement times in tetraplegic and paraplegic patients did not differ from those in normal subjects. All patients reported a sensation of subjective effort accompanying the execution of the mental tasks. These observations are compatible with an outflow processing underlying motor imagery.     

Lateral Mobility of the Cell Adhesion Molecule L1 Within the Surface Membrane of Morphologically Undifferentiated and Differentiated Neuroblastoma Cells

Lateral mobility and localization in the surface membrane of the adhesion molecule L1 was studied in morphologically undifferentiated and differentiated neuroblastoma cells to gain insight into its possible association with the different molecular forms of N-CAM. In undifferentiated cells, the fraction of mobile L1 molecules is high and similar to that of N-CAM 140. Upon long-term morphological differentiation, the fraction of mobile L1 molecules is reduced by a factor of three and is similar to that of N-CAM 180, the predominant molecular form of N-CAM in differentiated neuroblastoma cells. Comparable to N-CAM 180, L1 is also preferentially accumulated at contact sites between these cells as seen by indirect immunofluorescence. These observations raise the question of whether at least part of the L1 molecules may be directly or indirectly (e.g. via N-CAM 180) linked to the cytoskeleton, thus stabilizing cell contacts between differentiated cells.