Background and Purpose
There is a need for effective anti‐COVID‐19 treatments, mainly for individuals at risk of severe disease such as the elderly and the immunosuppressed. Drug repositioning has ...proved effective in identifying drugs that can find a new application for the control of coronavirus disease, in particular COVID‐19. The purpose of the present study was to find synergistic antiviral combinations for COVID‐19 based on lethal mutagenesis.
Experimental Approach
The effect of combinations of remdesivir and ribavirin on the infectivity of SARS‐CoV‐2 in cell culture has been tested. Viral populations were monitored by ultra‐deep sequencing, and the decrease of infectivity as a result of the treatment was measured.
Key Results
Remdesivir and ribavirin exerted a synergistic inhibitory activity against SARS‐CoV‐2, quantified both by CompuSyn (Chou‐Talalay method) and Synergy Finder (ZIP‐score model). In serial passage experiments, virus extinction was readily achieved with remdesivir‐ribavirin combinations at concentrations well below their cytotoxic 50 value, but not with the drugs used individually. Deep sequencing of treated viral populations showed that remdesivir, ribavirin, and their combinations evoked significant increases of the number of viral mutations and haplotypes, as well as modification of diversity indices that characterize viral quasi‐species.
Conclusion and Implications
SARS‐CoV‐2 extinction can be achieved by synergistic combination treatments based on lethal mutagenesis. In addition, the results offer prospects of triple drug treatments for effective SARS‐CoV‐2 suppression.
Epigenetic aging, according to 3 different epigenetic clocks, did not accelerate in a cohort of long-term aviremic HIV-infected adults after 4 years of follow-up. Measures of epigenetic age ...acceleration might be useful tools to predict the occurrence of clinical outcomes.
Abstract
Background
Human immunodeficiency virus (HIV) infection induces epigenetic age acceleration (EAA), but it remains unclear whether epigenetic aging continues to accelerate during successful antiretroviral therapy (ART) and prolonged virological suppression.
Methods
We longitudinally analyzed 63 long-term aviremic HIV-infected adults. Using blood DNA methylation patterns, we calculated EAA measures based on 3 epigenetic clocks (Horvath’s clock, PhenoAge, and GrimAge). We recorded the emergence of serious AIDS-related and non-AIDS-related events throughout the study to assess its association with EAA.
Results
All participants were on stable ART and were virologically suppressed. After 4 years of follow-up, PhenoAge-EAA and GrimAge-EAA showed no differences, whereas Horvath-EAA slightly decreased (median difference, –0.53 years; P = .015). Longitudinal changes in EAA measures were independent of changes in CD4 cell counts, the ART regimen, or other HIV-related factors. Nineteen percent of participants experienced a serious clinical event during the study. Horvath-EAA was significantly higher at baseline in participants with clinical events (P = .027). After adjusting for confounders, we found a trend toward an association of higher levels of all EAA measures at baseline with serious clinical events.
Conclusions
Epigenetic aging did not accelerate in long-term aviremic HIV-infected adults after 4 years of successful ART. EAA measures deserve further study as potential tools for predicting clinical events.
Populations of RNA viruses are composed of complex and dynamic mixtures of variant genomes that are termed mutant spectra or mutant clouds. This applies also to SARS-CoV-2, and mutations that are ...detected at low frequency in an infected individual can be dominant (represented in the consensus sequence) in subsequent variants of interest or variants of concern. Here we briefly review the main conclusions of our work on mutant spectrum characterization of hepatitis C virus (HCV) and SARS-CoV-2 at the nucleotide and amino acid levels and address the following two new questions derived from previous results: (i) how is the SARS-CoV-2 mutant and deletion spectrum composition in diagnostic samples, when examined at progressively lower cut-off mutant frequency values in ultra-deep sequencing; (ii) how the frequency distribution of minority amino acid substitutions in SARS-CoV-2 compares with that of HCV sampled also from infected patients. The main conclusions are the following: (i) the number of different mutations found at low frequency in SARS-CoV-2 mutant spectra increases dramatically (50- to 100-fold) as the cut-off frequency for mutation detection is lowered from 0.5% to 0.1%, and (ii) that, contrary to HCV, SARS-CoV-2 mutant spectra exhibit a deficit of intermediate frequency amino acid substitutions. The possible origin and implications of mutant spectrum differences among RNA viruses are discussed.
In HIV-1/HCV-coinfected patients, chronic HCV infection leads to an increased T-lymphocyte immune activation compared to HIV-monoinfected patients, thereby likely contributing to increase HIV-1 ...reservoir that is the major barrier for its eradication. Our objective was to evaluate the influence of HCV coinfection in HIV-1 viral reservoir size in resting (r) CD4+ T-cells (CD25-CD69-HLADR-). Multicenter cross-sectional study of 97 cART-treated HIV-1 patients, including 36 patients with HIV and HCV-chronic co-infection without anti-HCV treatment, 32 HIV patients with HCV spontaneous clearance and 29 HIV-monoinfected patients. rCD4+ T-cells were isolated and total DNA was extracted. HIV viral reservoir was measured by Alu-LTR qPCR. Differences between groups were calculated with a generalized linear model. Overall, 63.9% were men, median age of 41 years and Caucasian. Median CD4+ and CD8+ T-lymphocytes were 725 and 858 cells/mm
, respectively. CD4+ T nadir cells was 305 cells/mm
. Proviral HIV-1 DNA size was significantly increased in chronic HIV/HCV-coinfected compared to HIV-monoinfected patients (206.21 ± 47.38 vs. 87.34 ± 22.46, respectively; P = 0.009), as well as in spontaneously clarified HCV co-infected patients when compared to HIV-monoinfected individuals (136.20 ± 33.20; P = 0.009). HIV-1/HCV co-infected patients showed a larger HIV-1 reservoir size in comparison to HIV-monoinfected individuals. This increase could lead to a greater complexity in the elimination of HIV-1 reservoir in HIV-1/HCV-coinfected individuals, which should be considered in the current strategies for the elimination of HIV-1 reservoir.
SARS-CoV-2 isolates of a given clade may contain low frequency genomes that encode amino acids or deletions which are typical of a different clade.
Here we use high resolution ultra-deep sequencing ...to analyze SARS-CoV-2 mutant spectra.
In 6 out of 11 SARS-CoV-2 isolates from COVID-19 patients, the mutant spectrum of the spike (S)-coding region included two or more amino acids or deletions, that correspond to discordant viral clades. A similar observation is reported for laboratory populations of SARS-CoV-2 USA-WA1/2020, following a cell culture infection in the presence of remdesivir, ribavirin or their combinations. Moreover, some of the clade-discordant genome residues are found in the same haplotype within an amplicon.
We evaluate possible interpretations of these findings, and reviewed precedents for rapid selection of genomes with multiple mutations in RNA viruses. These considerations suggest that intra-host evolution may be sufficient to generate minority sequences which are closely related to sequences typical of other clades. The results provide a model for the origin of variants of concern during epidemic spread─in particular Omicron lineages─that does not require prolonged infection, involvement of immunocompromised individuals, or participation of intermediate, non-human hosts.
We report that ribavirin exerts an inhibitory and mutagenic activity on SARS-CoV-2-infecting Vero cells, with a therapeutic index higher than 10. Deep sequencing analysis of the mutant spectrum of ...SARS-CoV-2 replicating in the absence or presence of ribavirin indicated an increase in the number of mutations, but not in deletions, and modification of diversity indices, expected from a mutagenic activity. Notably, the major mutation types enhanced by replication in the presence of ribavirin were A→G and U→C transitions, a pattern which is opposite to the dominance of G→A and C→U transitions previously described for most RNA viruses. Implications of the inhibitory activity of ribavirin, and the atypical mutational bias produced on SARS-CoV-2, for the search for synergistic anti-COVID-19 lethal mutagen combinations are discussed.
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Leporinus macrocephalus testis is classified as anastomosing tubular type. • The seminiferous tubules empty directly into the testicular main ducts. • The testicular main ducts epithelium changes ...from simple cuboidal to pseudostratified. • The epithelial cells reveal the presence of granules PAS positive. • The immunoreactivity to androgen receptor is noted in the testicular main ducts.
The present study examined the testicular structure and the seminal pathway in freshwater fish
Leporinus macrocephalus (
Garavello and Britski, 1988). Twenty-five specimens of this species were studied. Testicular structure was analyzed using light and transmission electron microscopy. The testicular main ducts were examined by means of conventional histology, corrosion–cast technique and scanning electron microscopy. Additional techniques were applied for polysaccharides histochemistry and immunohistochemistry for androgen receptor. The testicular parenchyma was classified as the anastomosing tubular testis type with spermatogonia occurring along the lengths of the seminiferous tubules. The seminiferous tubules emptied directly into the testicular main ducts. The wall of the testicular main ducts in
L. macrocephalus consisted of three layers: epithelium, connective tissue and peritoneum. The epithelium changed from simple cuboidal to pseudostratified. The histochemical analysis revealed the presence of granules PAS positive in the epithelial cells. The immunoreactivity to androgen receptor was noted in the testicular main ducts through all cytoplasmic areas of epithelial cells.
RESUMEN El granuloma de células gigantes (GCG) es una patología de etiología no esclarecida que aparece tras traumatismos o procesos inflamatorios. Puede ser asintomático, debutar como una masa de ...comportamiento inflamatorio o comportarse de forma localmente agresiva. El diagnóstico resulta de la combinación de datos clínicos, radiológicos e histológicos. El tratamiento puede ser quirúrgico, mediante cirugías más o menos extensas, así como médico con diferentes fármacos. Se presenta el caso de un paciente intervenido de un GCG mandibular que acudió a nuestra consulta con una recidiva de la lesión, manejada quirúrgicamente mediante resección segmentaria y reconstrucción con colgajo libre de peroné, añadiendo al tratamiento la rehabilitación dental para realizar un manejo global del caso.
Abstract The research is interested in both ecological and identity (social) variables involved in increasing environmental commitment to Antarctic care. Two studies with inhabitants of two cities in ...the extreme south, and another with a national sample from three different geographical areas (north, center and south) participated by answering a self-administered survey. The instruments measured the perception of personal responsibility for Antarctic care in the present and future, Value of Antarctica, Antarctic regional ecological identity, and environmental beliefs. The core results show that identification with the Antarctic territory is important in determining the perception of responsibility and commitment to its care, and that this process is mediated by the value given to the polar continent. This mediation was observed in both the sample of locals and nationals. These results are discussed in relation to the importance of considering identity variables when developing models that aim to promote a pro-ecological attitude.
Resumen La investigación se interesa tanto en variables ecológicas como identitarias (sociales) que participan en el aumento del compromiso ambiental en el cuidado antártico. Dos estudios con habitantes del sur austral de dos ciudades, y otro con una muestra nacional de tres zonas geográficas diferentes (norte, centro y sur) participaron contestando una encuesta autoaplicada. Los instrumentos midieron la percepción de responsabilidad personal en el cuidado antártico en el presente y futuro, la valoración antártica, la identidad regional ecológica antártica y creencias ambientales. Los resultados centrales muestran que la identificación con el territorio antártico resulta importante para determinar la percepción de responsabilidad y compromiso en su cuidado, y que este proceso es mediado por el valor que se le otorga al continente helado. Dicha mediación se observó tanto en la muestra de locales como de nacionales. Se discuten estos resultados en torno a la importancia de considerar variables identitarias al desarrollar modelos orientados al fomento de la actitud proecológica.
Resumo A pesquisa está interessada tanto nas variáveis ecológicas quanto nas variáveis de identidade (sociais) envolvidas no aumento do envolvimento ambiental no cuidado antártico. Dois estudos com habitantes do sul de duas cidades, e outro com uma amostra nacional de três áreas geográficas diferentes (norte, centro e sul) participaram respondendo a uma pesquisa auto-administrada. Os instrumentos mediram a percepção de responsabilidade pessoal pelos cuidados antárticos no presente e no futuro, a valorização antártica, a identidade ecológica regional antártica e as crenças ambientais. Os resultados centrais mostram que a identificação com o território antártico é importante para determinar a percepção de responsabilidade e o compromisso com seu cuidado, e que este processo é mediado pelo valor colocado no continente congelado. Tal mediação foi observada tanto na amostra de locais como de nacionais. Estes resultados são discutidos em relação à importância de considerar as variáveis de identidade ao desenvolver modelos destinados a promover uma atitude pró-ecológica.
RESUMEN Introducción: Presentamos una paciente sometida a reconstrucción de articulación temporomandibular (ATM) con una prótesis de stock tipo Walter-Lorenz (Zimmer Biomet Inc., Biomet ...Microfixation, Jacksonville, FL) con el apoyo de un sistema de planificación virtual quirúrgica 3D y guías de corte elaboradas gracias a tecnología computer-aided-manufacturing (CAD/CAM). Caso clínico: Paciente mujer de 66 años con historia de múltiples cirugías de ATM bilaterales que acude de nuevo a consulta por empeoramiento funcional y dolor a nivel de ATM izquierda, portadora de una prótesis de Walter-Lorenz en la ATM derecha. Se interviene para colocación de otra prótesis de stock tipo Walter-Lorenz a nivel de ATM izquierda con planificación virtual quirúrgica 3D de las osteotomías de la fosa y la rama, y fabricación de las guías de corte con tecnología CAD/CAM. La cirugía se ajusta de manera precisa a la planificación previa. En las revisiones posteriores, la paciente presenta apertura oral como la previa y control del dolor. Conclusión: La reconstrucción de ATM con planificación quirúrgica virtual 3D de prótesis de stock Walter-Lorenz permite aumentar la precisión en su colocación y simplificar la intervención quirúrgica.
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