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Clinical outcomes of severe acute respiratory syndrome 2 (SARS-CoV-2) infection are highly heterogeneous, ranging from asymptomatic infection to lethal coronavirus disease 2019 (COVID-19). The factors underlying this heterogeneity remain insufficiently understood. Genetic association studies have suggested that genetic variants contribute to the heterogeneity of COVID-19 outcomes, but the underlying potential causal mechanisms are insufficiently understood. Here we show that common variants of the apolipoprotein E (APOE) gene, homozygous in approximately 3% of the world’s population1and associated with Alzheimer’s disease, atherosclerosis and anti-tumour immunity2–5, affect COVID-19 outcome in a mouse model that recapitulates increased susceptibility conferred by male sex and advanced age. Mice bearing the APOE2or APOE4variant exhibited rapid disease progression and poor survival outcomes relative to mice bearing the most prevalent APOE3allele. APOE2and APOE4mice exhibited increased viral loads as well as suppressed adaptive immune responses early after infection. In vitro assays demonstrated increased infection in the presence of APOE2 and APOE4 relative to APOE3, indicating that differential outcomes are mediated by differential effects of APOE variants on both viral infection and antiviral immunity. Consistent with these in vivo findings in mice, our results also show that APOEgenotype is associated with survival in patients infected with SARS-CoV-2 in the UK Biobank (candidate variant analysis, P= 2.6 × 10−7). Our findings suggest APOEgenotype to partially explain the heterogeneity of COVID-19 outcomes and warrant prospective studies to assess APOEgenotyping as a means of identifying patients at high risk for adverse outcomes.

Cutaneous leiomyosarcomas are malignant mesenchymal tumors of smooth muscle origin and are reported occasionally in avian species. A 14-y-old male laboratory White Carneau pigeon (Columba livia) was presented for surgical excision of a cervical soft tissue mass. Ultrasonography with color flow Doppler imaging revealed multiple cavitations of mixed echogenicity within the mass and vascularization. Histologically, the dermis and subcutis were expanded by a densely cellular multinodular mass comprised of fusiform cells forming haphazardly arranged broad streams and short interwoven bundles, often surrounding blood vessels and variably sized cavitations. Neoplastic cells were strongly immunopositive for desmin and α–smooth muscle actin, and negative for pancytokeratin, S100, and von Willebrand factor. Based on histopathology and IHC findings, the cutaneous mass was diagnosed as leiomyosarcoma (LMS). The pigeon died 312 d post-operatively. Postmortem examination revealed masses infiltrating the left and right pulmonary airways and one hepatic nodule, but no regrowth at the surgical site. Histologic and IHC evaluation of the pulmonary and hepatic masses were consistent with LMS, representing metastatic foci from the primary cutaneous LMS. Our case highlights the malignant behavior and histomorphologic features of cutaneous LMS in an avian species.

An understanding of early-onset mechanisms underlying age-related changes can be obtained by evaluating changes that precede frailty and end of life using histological characterization of age-related lesions. Histopathology-based information as a component of aging studies in mice can complement and add context to molecular, cellular, and physiologic data, but there is a lack of information regarding scoring criteria and lesion grading guidelines. This report describes the validation of a grading system, designated as the geropathology grading platform (GGP), which generated a composite lesion score (CLS) for comparison of histological lesion scores in tissues from aging mice. To assess reproducibility of the scoring system, multiple veterinary pathologists independently scored the same slides from the heart, lung, liver, and kidney from two different strains (C57BL/6 and CB6F1) of male mice at 8, 16, 24, and 32 months of age. There was moderate to high agreement between pathologists, particularly when agreement within a 1-point range was considered. CLS for all organs was significantly higher in older versus younger mice, suggesting that the GGP was reliable for detecting age-related pathology in mice. The overall results suggest that the GGP guidelines reliably distinguish between younger and older mice and may therefore be accurate in distinguishing between experimental groups of mice with more, or less, age-related pathology.

•Many resource-rich countries seek to moving forward in the LiB value chain.•It is crucial to examine internal and external struggles that shape state policies.•Chile shows the effects of having several conflicting accumulation strategies.•It has failed in developing value-added manufactures and R&D initiatives.•In addition, Chile is losing is losing ground in mineral supply.

Nanoscale communications is a new paradigm encompassing all concerns related to the exchange of information among devices at the nanometer scale. A network infrastructure consisting of a huge quantity of nano-devices is envisaged to ensure robust, reliable, and coordinated data transmission. This will enable a plethora of forthcoming applications and services in many different research fields, such as personalized medicine, synthetic biology, environmental science, and industry, which will lead to outstanding and unprecedented advances. The IEEE 1906.1 standard provides a conceptual and general framework to set the starting point for future developments in nanoscale communication networks. This article reviews the latest IEEE 1906.1 recommendations, observing their main features when applied to the electromagnetic (EM) nanocommunication area. We contribute by identifying the standard achievements and indicating future guidelines for the development of the upcoming standardization of EM nanoscale communications.

ABSTRACTOuter surface protein C (OspC) is one of the major lipoproteins expressed on the surface of Borrelia burgdorferiduring tick feeding and the early phase of mammalian infection. OspC is required for B. burgdorferito establish infection in both immunocompetent and SCID mice and has been proposed to facilitate evasion of innate immune defenses. However, the exact biological function of OspC remains elusive. In this study, we showed that the ospC-deficient spirochete could not establish infection in NOD-scid IL2rγnullmice that lack B cells, T cells, NK cells, and lytic complement. The ospCmutant also could not establish infection in anti-Ly6G-treated SCID and C3H/HeN mice (depletion of neutrophils). However, depletion of mononuclear phagocytes at the skin site of inoculation in SCID and C3H/HeN mice allowed the ospCmutant to establish infection in vivo. In phagocyte-depleted mice, the ospCmutant was able to colonize the joints and triggered neutrophilia during dissemination. Furthermore, we found that phagocytosis of green fluorescent protein (GFP)-expressing ospCmutant spirochetes by murine peritoneal macrophages and human THP-1 macrophage-like cells, but not in PMN-HL60, was significantly higher than parental wild-type B. burgdorferistrains, suggesting that OspC has an antiphagocytic property. In addition, overproduction of OspC in spirochetes also decreased the uptake of spirochetes by murine peritoneal macrophages. Together, our findings provide evidence that mononuclear phagocytes play a key role in clearance of the ospCmutant and that OspC promotes spirochetes' evasion of macrophages during early Lyme borreliosis.

ABSTRACTBorrelia burgdorferi, the causative agent of Lyme disease, must adapt to two diverse niches, an arthropod vector and a mammalian host. RpoS, an alternative sigma factor, plays a central role in spirochetal adaptation to the mammalian host by governing expression of many genes important for mammalian infection. B. burgdorferiis known to be unique in metal utilization, and little is known of the role of biologically available metals in B. burgdorferi. Here, we identified two transition metal ions, manganese (Mn2+) and zinc (Zn2+), that influenced regulation of RpoS. The intracellular Mn2+level fluctuated approximately 20-fold under different conditions and inversely correlated with levels of RpoS and the major virulence factor OspC. Furthermore, an increase in intracellular Mn2+repressed temperature-dependent induction of RpoS and OspC; this repression was overcome by an excess of Zn2+. Conversely, a decrease of intracellular Mn2+by deletion of the Mn2+transporter gene, bmtA, resulted in elevated levels of RpoS and OspC. Mn2+affected RpoS through BosR, a Fur family homolog that is required for rpoSexpression: elevated intracellular Mn2+levels greatly reduced the level of BosR protein but not the level of bosRmRNA. Thus, Mn2+and Zn2+appeared to be important in modulation of the RpoS pathway that is essential to the life cycle of the Lyme disease spirochete. This finding supports the emerging notion that transition metals such as Mn2+and Zn2+play a critical role in regulation of virulence in bacteria.

N-Nitrosodimethylamine (NDMA) is a DNA-methylating agent that has been discovered to contaminate water, food, and drugs. The alkyladenine DNA glycosylase (AAG) removes methylated bases to initiate the base excision repair (BER) pathway. To understand how gene-environment interactions impact disease susceptibility, we study Aag-knockout (Aag−/−) and Aag-overexpressing mice that harbor increased levels of either replication-blocking lesions (3-methyladenine [3MeA]) or strand breaks (BER intermediates), respectively. Remarkably, the disease outcome switches from cancer to lethality simply by changing AAG levels. To understand the underlying basis for this observation, we integrate a suite of molecular, cellular, and physiological analyses. We find that unrepaired 3MeA is somewhat toxic, but highly mutagenic (promoting cancer), whereas excess strand breaks are poorly mutagenic and highly toxic (suppressing cancer and promoting lethality). We demonstrate that the levels of a single DNA repair protein tip the balance between blocks and breaks and thus dictate the disease consequences of DNA damage.