Replicative fitness and pathogenicity of primate lentiviruses in lymphoid tissue, primary human and chimpanzee cells: relation to possible jumps to humans.

BACKGROUND: Simian immunodeficiency viruses (SIV) have been jumping between non-human primates in West/Central Africa for thousands of years and yet, the HIV-1 epidemic only originated from a primate lentivirus over 100 years ago. METHODS: This study examined the replicative fitness, transmission, restriction, and cytopathogenicity of 22 primate lentiviruses in primary human lymphoid tissue and both primary human and chimpanzee peripheral blood mononuclear cells. FINDINGS: Pairwise competitions revealed that SIV from chimpanzees (cpz) had the highest replicative fitness in human or chimpanzee peripheral blood mononuclear cells, even higher fitness than HIV-1 group M strains responsible for worldwide epidemic. The SIV strains belonging to the "HIV-2 lineage" (including SIVsmm, SIVmac, SIVagm) had the lowest replicative fitness. SIVcpz strains were less inhibited by human restriction factors than the "HIV-2 lineage" strains. SIVcpz efficiently replicated in human tonsillar tissue but did not deplete CD4+ T-cells, consistent with the slow or nonpathogenic disease observed in most chimpanzees. In contrast, HIV-1 isolates and SIV of the HIV-2 lineage were pathogenic to the human tonsillar tissue, almost independent of the level of virus replication. INTERPRETATION: Of all primate lentiviruses, SIV from chimpanzees appears most capable of infecting and replicating in humans, establishing HIV-1. SIV from other Old World monkeys, e.g. the progenitor of HIV-2, replicate slowly in humans due in part to restriction factors. Nonetheless, many of these SIV strains were more pathogenic than SIVcpz. Either SIVcpz evolved into a more pathogenic virus while in humans or a rare SIVcpz, possibly extinct in chimpanzees, was pathogenic immediately following the jump into human. FUNDING: Support for this study to E.J.A. was provided by the NIH/NIAID R01 AI49170 and CIHR project grant 385787. Infrastructure support was provided by the NIH CFAR AI36219 and Canadian CFI/Ontario ORF 36287. Efforts of J.A.B. and N.J.H. was provided by NIH AI099473 and for D.H.C., by VA and NIH AI AI080313.

Synthesizing Methuselah: The Question of Artificial Agelessness.

As biological organisms, we age and, eventually, die. However, age's deteriorating effects may not be universal. Some theoretical entities, due to their synthetic composition, could exist independently from aging-artificial general intelligence (AGI). With adequate resource access, an AGI could theoretically be ageless and would be, in some sense, immortal. Yet, this need not be inevitable. Designers could imbue AGIs with artificial mortality via an internal shut-off point. The question, though, is, should they? Should researchers curtail an AGI's potentially endless lifespan by deliberately making it mortal? It is this question that this article explores. First, it considers what type of AGI is under discussion before outlining how such beings could be ageless. Then, after clarifying the type of immortality under discussion and arguing that imbuing an AGI with synthetic aging would be person-affecting, the article explores four core conundrums: (i) deliberately causing a morally significant being's death; (ii) immortality's associated harms; (iii) concerns about immortality's unequal assignment; and (iv) the danger of immortal AGI overlords. The article concludes that while prudence requires we create an aging AGI, in the face of the material harm such an action would constitute, this is an insufficient reason to justify doing so.

A critique of whole body gestational donation.

In her controversial paper, Anna Smajdor proposes that brain-dead people could be used as gestation units for prospective parents unable or unwilling to undertake the act themselves-what she terms whole body gestational donation (WBGD). She explores the ethical issues of such an idea and, comparing it with traditional organ donation, asserts that such deceased surrogacy could be a way of outsourcing pregnancy's harms to a populace unable to be affected by them. She argues that if the prospect is unacceptable, this may reveal some underlying problems with traditional cadaveric organ donation. Smajdor's analysis, however, overlooks several problems arising from WBGD. This paper provides an account of those issues and argues that, in addition to WBGD being viscerally unpleasant, it is also ethically unviable. The paper starts by providing an account of WBGD before acknowledging its negative response within traditional and social media. After arguing that such cursory and gut reactions are insufficient to reject the proposal outright, this paper then provides three concerns regarding WBGD omitted by Smajdor: (i) the co-opting of life-saving organs for reproduction, (ii) the discrepancy between using cadaveric organs to save a life versus creating one, and (iii) the universalization of feminist concerns regarding reproductive body commodification. The paper concludes by tentatively agreeing with Smajdor that considering WBGD may help reveal vulnerable assumptions regarding organ donation and surrogacy, but that the significant ethical issues raised may prove insurmountable and make the intervention-thought experiment or otherwise-untenable.

Normality and Disability in H. G. Wells's "The Country of the Blind".

Describing someone as disabled means evaluating their relationship with their environment, body, and self. Such descriptions pivot on the person's perceived limitations due to their atypical embodiment. However, impairments are not inherently pathological, nor are disabilities necessarily deviations from biological normality, a discrepancy often articulated in science fiction via the presentation of radically altered environments. In such settings, non-impaired individuals can be shown to be unsuited to the world they find themselves in. One prime example of this comes courtesy of H. G. Wells's "The Country of the Blind." This paper demonstrates science fiction's capacity to decouple disability's normative quality from classical medical models stemming from the medical Enlightenment movement by challenging the idea of the biologically normal. It first provides a brief account of disability before exploring the concept of medical normality. It then problematizes the biologically consistent being, arguing that health is only understandable when environmentally situated. Next, the paper provides an overview of "The Country of the Blind" before analyzing how it challenges the idea of biological normality, framing it as a social product rather than a universal constant. Finally, the paper concludes that science fiction narratives effectively interrogate our world's seemingly consistent trends by envisioning (un)desirable alternatives.

Specialized DNA Structures Act as Genomic Beacons for Integration by Evolutionarily Diverse Retroviruses.

Retroviral integration site targeting is not random and plays a critical role in expression and long-term survival of the integrated provirus. To better understand the genomic environment surrounding retroviral integration sites, we performed a meta-analysis of previously published integration site data from evolutionarily diverse retroviruses, including new experimental data from HIV-1 subtypes A, B, C and D. We show here that evolutionarily divergent retroviruses exhibit distinct integration site profiles with strong preferences for integration near non-canonical B-form DNA (non-B DNA). We also show that in vivo-derived HIV-1 integration sites are significantly more enriched in transcriptionally silent regions and transcription-silencing non-B DNA features of the genome compared to in vitro-derived HIV-1 integration sites. Integration sites from individuals infected with HIV-1 subtype A, B, C or D viruses exhibited different preferences for common genomic and non-B DNA features. In addition, we identified several integration site hotspots shared between different HIV-1 subtypes, all of which were located in the non-B DNA feature slipped DNA. Together, these data show that although evolutionarily divergent retroviruses exhibit distinct integration site profiles, they all target non-B DNA for integration. These findings provide new insight into how retroviruses integrate into genomes for long-term survival.

The Staphylococcus aureus protein IsdA increases SARS CoV-2 replication by modulating JAK-STAT signaling.

The Severe Acute Respiratory Syndrome Coronavirus 2 (CoV-2) pandemic has affected millions globally. A significant complication of CoV-2 infection is secondary bacterial co-infection, as seen in approximately 25% of severe cases. The most common organism isolated during co-infection is Staphylococcus aureus. Here, we describe the development of an in vitro co-infection model where both viral and bacterial replication kinetics may be examined. We demonstrate CoV-2 infection does not alter bacterial interactions with host epithelial cells. In contrast, S. aureus enhances CoV-2 replication by 10- to 15-fold. We identify this pro-viral activity is due to the S. aureus iron-regulated surface determinant A (IsdA) protein and demonstrate IsdA modifies host transcription. We find that IsdA alters Janus Kinase - Signal Transducer and Activator of Transcription (JAK-STAT) signaling, by affecting JAK2-STAT3 levels, ultimately leading to increased viral replication. These findings provide key insight into the molecular interactions between host cells, CoV-2 and S. aureus during co-infection.

The Desirability of Difference: Georges Canguilhem and Body Integrity Identity Disorder.

Opponents of the provision of therapeutic, healthy limb amputation in Body Integrity Identity Disorder cases argue that such surgeries stand in contrast to the goal of medical practice - that of health restoration and maintenance. This paper refutes such a conclusion via an appeal to the nuanced and reflective model of health proposed by Georges Canguilhem. The paper examines the conceptual entanglement of the statistically common with the normatively desirable, arguing that a healthy body can take multiple forms, including that of an amputee, provided that such a form enables the continuing ability to initiate new norms of existence. It concludes that the practice of healthy limb amputation in cases of Body Integrity Identity Disorder is not only compatible with the goal of medicine but is potentially the only method of achieving this goal in the face of a complex and often mischaracterized disorder.

Enhancement of CD4 Binding, Host Cell Entry, and Sensitivity to CD4bs Antibody Inhibition Conferred by a Natural but Rare Polymorphism in the HIV-1 Envelope.

A rare but natural polymorphism in the HIV-1 envelope (Env) glycoprotein, lysine at position 425 was selected as a mutation conferring resistance to maraviroc (MVC) in vitro. N425K has not been identified in HIV-infected individuals failing an MVC-based treatment. This study reports that the rare K425 polymorphism in an HIV-1 subtype A Env has increased affinity for CD4, resulting in faster host cell entry kinetics and the ability to scavenge for low cell surface expression of CD4 to mediate entry. Whereas the subtype A wild-type isolate-74 Env (N425) is inhibited by soluble (s) CD4, HIV-1 with K425 A74 Env shows enhanced infection and the ability to infect CCR5+ cells when pretreated with sCD4. Upon adding K425 or N425 HIV-1 to CD4+/CCR5+ cells along with RANTES/CCL3, only K425 HIV-1 was able to infect cells when CCR5 recycled/returned to the cell surface at 12 h post-treatment. These findings suggest that upon binding to CD4, K425 Env may maintain a stable State 2 "open" conformation capable of engaging CCR5 for entry. Only K425 was significantly more sensitivity than wild-type N425 A74 to inhibition by the CD4 binding site (bs) compound, BMS-806, the CD4bs antibody, VRC01 and N6, and the single-chain CD4i antibody, SCm9. K425 A74 was also capable of activating B cells expressing the VRC01 surface immunoglobulin. In summary, despite increased replicative fitness, we propose that K425 HIV-1 may be counterselected within infected individuals if K425 HIV-1 is rapidly eliminated by CD4bs-neutralizing antibodies. IMPORTANCE Typically, a natural amino acid polymorphism is found as the wild-type sequence in the HIV-1 population if it provides a selective advantage to the virus. The natural K425 polymorphism in HIV-1 Env results in higher host cell entry efficiency and greater replicative fitness by virtue of its high binding affinity to CD4. The studies presented herein suggest that the rare K425 HIV-1, compared to the common N425 HIV-1, may be more sensitive to inhibition by CD4bs-neutralizing antibodies (i.e., antibodies that bind to the CD4 binding pocket on the HIV-1 envelope glycoprotein). If CD4bs antibodies did emerge in an infected individual, the K425 HIV-1 may be hypersensitive to inhibition, and thus this K425 virus variant may be removed from the HIV-1 swarm despite its higher replication fitness. Studies are now underway to determine whether addition of the K425 polymorphism into the Envelope-based HIV-1 vaccines could enhance protective immunity.

The cryonic refugee: appropriate analogy or confusing rhetoric?

Cryopreservation presents the possibility of circumventing irreversible death through the body's extreme cooling. Once cooled, this 'cryon' is then stored at sub-zero temperatures until medical knowledge enables curative revival. However, the possibility of the post-cryopreserved supporting themselves, both economically and socially, is dubious; they will likely need state assistance. What a future society owes the post-cryopreserved, and why, remains unclear. One potential solution is to consider revivals as comparable to refugees, with the latter fleeing spatially and the former fleeing temporally. But, the appropriateness of the 'cryonic refugee' remains unconsidered. This paper uses the 1951 Refugee Convention to clarify refugeehood's four necessary characteristics before exploring whether these qualities apply to the temporally displaced. It concludes that while similarities exist, the comparison fails due to the limitations placed on the form of persecution that one flees and why repatriation is impossible. Thus, any assistive obligation must come from an alternative source.

Early Warning Measurement of SARS-CoV-2 Variants of Concern in Wastewaters by Mass Spectrometry.

Wastewater surveillance has rapidly emerged as an early warning tool to track COVID-19. However, the early warning measurement of new SARS-CoV-2 variants of concern (VOCs) in wastewaters remains a major challenge. We herein report a rapid analytical strategy for quantitative measurement of VOCs, which couples nested polymerase chain reaction and liquid chromatography-mass spectrometry (nPCR-LC-MS). This method showed a greater selectivity than the current allele-specific quantitative PCR (AS-qPCR) for tracking new VOC and allowed the detection of multiple signature mutations in a single measurement. By measuring the Omicron variant in wastewaters across nine Ontario wastewater treatment plants serving over a three million population, the nPCR-LC-MS method demonstrated a better quantification accuracy than next-generation sequencing (NGS), particularly at the early stage of community spreading of Omicron. This work addresses a major challenge for current SARS-CoV-2 wastewater surveillance by rapidly and accurately measuring VOCs in wastewaters for early warning.

Differential diagnosis of acute traumatic hip pain in the elderly.

Elderly patients who present with an inability to weight bear following a fall, with normal radiographs, should be appropriately investigated to rule out an occult hip fracture (OHF). We aim to identify both the range and incidence of the differential diagnosis of acute traumatic hip pain in a large series of patients investigated for OHF. A retrospective analysis of consecutive patients investigated for an OHF with magnetic resonance imaging (MRI) was performed. Dedicated musculo- skeletal radiologists reported the MRI scans. All diagnoses including hip fractures, other fractures and soft tissue injuries were recorded. Case notes were reviewed for all patients to identify subsequent complications, management and outcomes. A total of 157 patients fulfilled the inclusion criteria. 52 (33%) patients had a fracture of the proximal femur. The majority of patients with proximal femoral fractures required surgical intervention. 9 patients who had fractures of the greater trochanter of the femur without fracture extension across the femoral neck were managed non-operatively. 40 (25%) patients had fractures of the pelvis, with a combined pubic rami and sacral fracture occurring frequently. The most common diagnosis was a soft tissue injury alone that was seen in 60 (38%) patients imaged. Injuries to the gluteal muscle group, iliopsaos complex and trochanteric bursa were most prevalent. All patients with soft tissue injuries or fractures of the pelvis were successfully managed non-operatively. This study highlights a wide range of differential diagnoses in elderly patients presenting with acute traumatic hip pain. The proximal femur was fractured in 33% of patients imaged for OHFs in our series. The most common diagnosis was a soft tissue injury around the hip and pelvis ; these injuries can be successfully managed without surgery.

An Amino Acid Polymorphism within the HIV-1 Nef Dileucine Motif Functionally Uncouples Cell Surface CD4 and SERINC5 Downregulation.

Serine incorporator 5 (SERINC5) reduces the infectivity of progeny HIV-1 virions by incorporating into the outer host-derived viral membrane during egress. To counter SERINC5, the HIV-1 accessory protein Nef triggers SERINC5 internalization by engaging the adaptor protein 2 (AP-2) complex using the [D/E]xxxL[L/I]167 Nef dileucine motif. Nef also engages AP-2 via its dileucine motif to downregulate the CD4 receptor. Although these two Nef functions are related, the mechanisms governing SERINC5 downregulation are incompletely understood. Here, we demonstrate that two primary Nef isolates, referred to as 2410 and 2391 Nef, acquired from acutely HIV-1 infected women from Zimbabwe, both downregulate CD4 from the cell surface. However, only 2410 Nef retains the ability to downregulate cell surface SERINC5. Using a series of Nef chimeras, we mapped the region of 2391 Nef responsible for the functional uncoupling of these two antagonistic pathways to the dileucine motif. Modifications of the first and second x positions of the 2410 Nef dileucine motif to asparagine and aspartic acid residues, respectively (ND164), impaired cell surface SERINC5 downregulation, which resulted in reduced infectious virus yield in the presence of SERINC5. The ND164 mutation additionally partially impaired, but did not completely abrogate, Nef-mediated cell surface CD4 downregulation. Furthermore, the patient infected with HIV-1 encoding 2391 Nef had stable CD4+ T cell counts, whereas infection with HIV-1 encoding 2410 Nef resulted in CD4+ T cell decline and disease progression. IMPORTANCE A contributing factor to HIV-1 persistence is evasion of the host immune response. HIV-1 uses the Nef accessory protein to evade the antiviral roles of the adaptive and intrinsic innate immune responses. Nef targets SERINC5, a restriction factor which potently impairs HIV-1 infection by triggering SERINC5 removal from the cell surface. The molecular determinants underlying this Nef function remain incompletely understood. Recent studies have found a correlation between the extent of Nef-mediated SERINC5 downregulation and the rate of disease progression. Furthermore, single-residue polymorphisms outside the known Nef functional motifs can modulate SERINC5 downregulation. The identification of a naturally occurring Nef polymorphism impairing SERINC5 downregulation in this study supports a link between Nef downregulation of SERINC5 and the rate of plasma CD4+ T cell decline. Moreover, the observed functional impairments of this polymorphism could provide clues to further elucidate unknown aspects of the SERINC5 antagonistic pathway via Nef.

Treating COVID-19 Acute Severe Hypoxemic Respiratory Failure: First Case Report Utilizing Dexamethasone, Remdesivir, and Convalescent Plasma in Operation Inherent Resolve.

Coronavirus 2019 (COVID-19) has spread across the globe with a concerningly high infectivity resulting in the World Health Organization deeming it a pandemic. It has resulted in thousands of deaths and placed enormous strain on communities, healthcare systems and healthcare workers as they battle shortages of ventilators, supplies, and difficulties in protecting patients and hospital staff alike. Challenges in managing the disease have led to new treatment and management strategies as healthcare teams struggle to adapt. We present the first case of COVID-19 managed in the austere deployed environment of Operation Inherent Resolve in which the patient was treated with dexamethasone, remdesivir, COVID-19 convalescent plasma, positive pressure ventilation, and proning. We discuss some of the inherent and unique challenges of caring for a patient in this resource constrained environment with a brief review of the literature on the treatment and management.

Elective amputation and neuroprosthetic limbs.

This paper explores the impact that developments in the field of neuroprosthetics will have on the ethical viability of healthy limb amputation, specifically in cases of Body Integrity Identity Disorder (BIID). Developments in the field have meant that the prospect of such artificial components matching the utility of their biological counterparts is now a possibility. As such, arguments against the provision of therapeutic, healthy limb amputation, which are grounded in the perceived resultant harm of disability, need to be reconsidered. Drawing on philosophical insights, as well as the field of disability studies and BIID research, this paper argues that such neuroprosthetics presents a challenge for the fundamental dichotomy between the disabled and non-disabled, including the latter's perceived superiority. It goes on to suggest that healthy limb amputation, for those with BIID, should not be dismissed simply because of the distastefulness of the procedure, but rather be evaluated based upon its own merits.

Accumulation of integrase strand transfer inhibitor resistance mutations confers high-level resistance to dolutegravir in non-B subtype HIV-1 strains from patients failing raltegravir in Uganda.

BACKGROUND: Increasing first-line treatment failures in low- and middle-income countries (LMICs) have led to increased use of integrase strand transfer inhibitors (INSTIs) such as dolutegravir. However, HIV-1 susceptibility to INSTIs in LMICs, especially with previous raltegravir exposure, is poorly understood due to infrequent reporting of INSTI failures and testing for INSTI drug resistance mutations (DRMs). METHODS: A total of 51 non-subtype B HIV-1 infected patients failing third-line (raltegravir-based) therapy in Uganda were initially selected for the study. DRMs were detected using Sanger and deep sequencing. HIV integrase genes of 13 patients were cloned and replication capacities (RCs) and phenotypic susceptibilities to dolutegravir, raltegravir and elvitegravir were determined with TZM-bl cells. Spearman's correlation coefficient was used to determine cross-resistance between INSTIs. RESULTS: INSTI DRMs were detected in 47% of patients. HIV integrase-recombinant virus carrying one primary INSTI DRM (N155H or Y143R/S) was susceptible to dolutegravir but highly resistant to raltegravir and elvitegravir (>50-fold change). Two patients, one with E138A/G140A/Q148R/G163R and one with E138K/G140A/S147G/Q148K, displayed the highest reported resistance to raltegravir, elvitegravir and even dolutegravir. The former multi-DRM virus had WT RC whereas the latter had lower RCs than WT. CONCLUSIONS: In HIV-1 subtype A- and D-infected patients failing raltegravir and harbouring INSTI DRMs, there is high-level resistance to elvitegravir and raltegravir. More routine monitoring of INSTI treatment may be advised in LMICs, considering that multiple INSTI DRMs may have accumulated during prolonged exposure to raltegravir during virological failure, leading to high-level INSTI resistance, including dolutegravir resistance.