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Abstract: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with a hyperinflammatory state and lymphocytopenia, a hallmark that appears as both signature and prognosis of disease severity outcome. Although cytokine storm and a sustained inflammatory state are commonly associated with immune cell depletion, it is still unclear whether direct SARS-CoV-2 infection of immune cells could also play a role in this scenario by harboring viral replication. We found that monocytes, as well as both B and T lymphocytes, were susceptible to SARS-CoV-2 infection in vitro, accumulating double-stranded RNA consistent with viral RNA replication and ultimately leading to expressive T cell apoptosis. In addition, flow cytometry and immunofluorescence analysis revealed that SARS-CoV-2 was frequently detected in monocytes and B lymphocytes from coronavirus disease 2019 (COVID-19) patients. The rates of SARS-CoV-2-infected monocytes in peripheral blood mononuclear cells from COVID-19 patients increased over time from symptom onset, with SARS-CoV-2-positive monocytes, B cells, and CD4+ T lymphocytes also detected in postmortem lung tissue. These results indicated that SARS-CoV-2 infection of blood-circulating leukocytes in COVID-19 patients might have important implications for disease pathogenesis and progression, immune dysfunction, and virus spread within the host.

ABSTRACT Members of the family Tellinidae are considered major components of trophic chains in sheltered sandy beaches located in temperate and tropical waters, due to their high number of species [...]

Several studies have been conducted to explain patterns of the abundance, richness and diversity of sandy-beach macrofauna; however, such analyses have ignored the overall functional structure of macrofauna communities. Few studies have examined polychaete feeding guilds on sandy beach environments. To examine the effects of environmental factors on polychaete feeding guilds on sandy beaches, 12 sandy beaches from five islands in Sepetiba Bay were sampled. A total of 24 polychaete morphospecies, grouped among 21 families, were identified in these sandy beaches. The polychaete species were classified into 10 feeding guilds, and the SDT guild (suspended-deposit feeders, discretely motile, with tentacles) was the most abundant feeding guild, with 34.2% of total number of organisms. The highest trophic importance index and index of trophic diversity values were recorded on the sheltered beaches. A canonical correspondence analysis showed that the exposure rate, beach length, and grain size of the beach sediment significantly affected the polychaete feeding guild distribution and abundance. We can conclude that sheltered beaches have a higher diversity of feeding guilds than exposed beaches and that the biological descriptors of the feeding guilds are directly associated with the grain size of the sediment. [ABSTRACT FROM PUBLISHER]

Macrofauna of sheltered and pocket beaches located in embayments, estuaries or landward of protective reefs has not been adequately assessed in beach ecology. In this setting, the concurrent role of large-scale morphodynamics and wave-exposure gradients in shaping biological patterns is still uncertain. To examine variations in community descriptors and the influence of physical factors on macrofauna, 12 sandy beaches on five islands within Sepetiba Bay (SE Brazil) were characterized in terms of beach morphodynamics and dimensions (length and width), such as geographical position relative to the bay mouth. A total of 80 species were collected and identified. Community descriptors of macrofauna responded to morphodynamics and exposure gradients. Increases in species richness, and abundance, from harsh reflective (coarse sands, steep slopes) to benign dissipative (fine sands, gentle slopes) beaches, and from the bay mouth (exposed beaches) towards the inner bay (sheltered beaches) were observed. Mollusks were the most abundant macrofaunal group, followed by crustaceans and polychaetes. Crustaceans dominated the beaches near the bay mouth, whereas mollusks were more abundant on the beaches farther from the bay mouth. Canonical correspondence analysis showed that the degree of exposure, distance from the bay mouth, beach index, and beach length and width significantly affected the macrofauna distribution and abundance, creating an environmental gradient along Sepetiba Bay. Differences in macrofauna composition among the beaches studied were associated with beach length and width. In this sense, spatial variation of macrofauna among beaches can be a function of intertidal area. These results indicate that community characteristics in the sandy beaches studied are affected by several physical characteristics, but also by other factors that are affected by coastal processes. [ABSTRACT FROM AUTHOR]

The population dynamics and secondary production of the cirolanid isopod Excirolana braziliensis are compared between two distinct sandy beaches. Monthly sampling from June 1998 through July 2000 was carried out at Grumari (a reflective beach with coarse sand and steeper slope) and Restinga da Marambaia (an intermediate beach with fine sand and moderate slope), both located in Rio de Janeiro State (23° 5), southeastern Brazil. Sampling was conducted according to a systematic design in which two transects (fixed 500 meters apart) were established, each with 10 equally spaced sampling strata. From each stratum, five replicates (0.04 square meters) were taken. Highest population abundances were observed in spring and summer on both beaches. The beaches differed significantly in physical parameters and the characteristics of their inhabitant populations: (1) Grumari Beach had a steeper slope, coarse sands, and a short swash period; (2) the abundance of total population, fecundity at length, and egg production potential were higher at Restinga da Marambaia; and (3) individual growth of males was higher at Grumari. Mean length at sexual maturity (L50%), mortality, growth of females, secondary production, and mean annual biomass did not show significant differences between beaches. Variations in population parameters of E. braziliensis might be regulated by phenotypic adjustment to local conditions, optimizing fitness, and especially enabling species to adapt to different physical conditions. [ABSTRACT FROM AUTHOR]

Demographic and life-history attributes of the mole crab Emerita brasiliensis were analysed along 2700 km of the Atlantic coast of South America, including sandy beaches at the southernmost limit (Uruguay) and at the core of its geographical range (Brazil). Population features varied markedly within this range and exhibited systematic geographical patterns of variation. Abundance significantly increased from temperate to subtropical beaches, and the same held true for the asymptotic weight of males. Conversely, length at maturity and asymptotic weight of females increased from subtropical to temperate beaches, being inversely related to sea water temperature. Macroecological patterns in abundance and body weight showed the first large-scale evidence of scaling of population density to body size for a sandy beach population. Mortality rates (both sexes) followed a nonlinear increase from low-density temperate beaches to high-density subtropical beaches. The effect of habitat quality and availability could explain discontinuities in the species distribution within its range, and also differential responses in life-history attributes at a local scale. Asymmetries and converse latitudinal trends between sexes suggest that there is not a single general factor determining large-scale patterns in life-history traits of this species. Our results reinforce the view that density-dependent and environmental factors operating together regulate sandy beach populations. The need to develop macroecological studies in sandy beach ecology is highlighted, as knowledge acquired from local to large spatial scales throws light on population structure and regulation mechanisms. [ABSTRACT FROM AUTHOR]

Estimates the growth parameters, mortality and reproduction of the isopod Excirolana braziliensis at Prainha Beach in Rio de Janeiro, Brazil from June 1993 to May 1995. Mean fecundity of the females during the sampling period; Average length of the organism at sexual maturity; Estimate of total instantaneous mortality.

The embryonic development and reproductive strategy of Pseudorchestoidea brasiliensis, a talitrid amphipod of the supra- and midlittoral zones, were investigated by combining collections from June 1993 to May 1995 at Prainha, Rio de Janeiro (23°05'S and 43°25'W). The initial stage of embryonic development (I) was most frequent and was seen in about 70% of ovigerous females. Mean embryo volume in the final stage of development was almost twice that in the initial stage. Brood mortality between embryonic Stages I and IV was estimated at 11.42%. Multivoltism, continuous reproduction, low brood mortality (may be caused by better parental care with offspring) and the larger number of females than males in the population were indicated as compensating factors for the low fecundity observed in P. brasiliensis. [ABSTRACT FROM AUTHOR]

Influenza A (IAV) viruses cause more than two million annual episodes of seasonal acute respiratory infections (ARI) and approximately 500 thousand deaths worldwide. Depending on virus strain and host immune status, acute infections by IAV may reach sites other than the respiratory tract. In the present study, IAV virus RNA and antigens were searched for in tissues of palatine tonsils and adenoids removed from patients without ARI symptoms. A real-time RT-PCR screening revealed that 8 tissue samples from 7 patients out of 103 were positive for IAV. Positive samples were subjected to NGS and 3 of 8 tissues yielded complete IAV pH1N1 genomes, whereas in 5 samples the PB1 gene was not fully assembled. Phylogenetic analysis placed tonsil-derived IAV in clusters clearly segregated from contemporaneous Brazilian viruses. Flow cytometry of dispersed tissue fragments and serial immunohistochemistry of paraffin-embedded sections of naturally infected biopsies, indicated that CD20+ B lymphocytes, CD8+ T lymphocytes, and CD11c+ cells are susceptible to IAV infection. We sought to investigate whether these lymphoid tissues could be sites of viral replication and sources of viable virus particles. MDCK cells were inoculated with tissue lysates enabling recovery of one IAV isolate confirmed by immunofluorescence, RT-qPCR and NGS. The data indicate that lymphoid tissues not only harbor expression of IAV proteins, but also contain infectious virus. Asymptomatic long term infection raises the possibility of IAV shedding from tonsils which may have an impact on host-to-host transmission. [ABSTRACT FROM AUTHOR]