Efficacy of cryotherapy for the treatment of cutaneous leishmaniasis: meta-analyses of clinical trials.

BACKGROUND: Cryotherapy is a local treatment for cutaneous leishmaniasis with variable efficacy and greater safety than conventional treatment. The objective of this study is to evaluate the efficacy and safety of cryotherapy for the treatment of cutaneous leishmaniasis and to compare it with pentavalent antimonials. METHODS: A meta-analysis based on a search of nine databases with eight strategies was conducted. Inclusion and exclusion criteria were applied, the methodological quality of each article was evaluated, and the reproducibility of the study selection and information extraction from each clinical trial was assured. The per lesion and per patient efficacy was calculated, and a meta-analysis of relative risks with the random effects model and the Dersimonian and Laird's, Begg, and Egger tests, along with a sensitivity analysis, were performed. A meta-regression based on the methodological quality of the trials included was also performed. RESULTS: Eight studies were included in which respective per lesion efficacies of 67.3 % and 67.7 % were reported for cryotherapy and pentavalent antimonials. In 271 patients treated with cryotherapy and in 199 with pentavalent antimonials, respective per protocol and intent to treat efficacies of 63.6 % and 54.2 % were found in the first group, and per protocol and intent to treat efficacies of 74.7 % and 68.3 % were found in the second group. The relative risk for the comparison of efficacy in the two groups was 0.73 (0.42-1.29). The results of the sensitivity analysis and the meta-regression analysis of relative risks were statistically equal to the overall results. CONCLUSION: This investigation provides evidence in favor of the use of cryotherapy given that its efficacy is similar to that of pentavalent antimonials.

Comparison among plaque assay, tissue culture infectious dose (TCID50) and real-time RT-PCR for SARS-CoV-2 variants quantification.

Background and Objectives: SARS-CoV-2 variants of concern (VOC) and interest (VOI) pose a significant threat to public health because the rapid change in the SARS-CoV-2 genome can alter viral phenotypes such as virulence, transmissibility and the ability to evade the host response. Hence, SARS-CoV-2 quantification techniques are essential for timely diagnosis and follow-up. Besides, they are vital to understanding viral pathogenesis, antiviral evaluation, and vaccine development. Materials and Methods: Five isolates of SARS-CoV-2: D614G strain (B.1), three VOC (Alpha, Gamma and Delta), and one VOI (Mu) were used to compare three techniques for viral quantification, plaque assay, median tissue culture infectious dose (TCID50) and real-time RT-PCR. Results: Plaque assay showed viral titers between 0.15 ± 0.01×107 and 1.95 ± 0.09×107 PFU/mL while viral titer by TCID50 assay was between 0.71 ± 0.01×106 to 4.94 ± 0.80×106 TCID50/mL for the five SARS-CoV-2 isolates. The PFU/mL titer obtained by plaque and the calculated from TCID50 assays differed by 0.61 log10, 0.59 log10, 0.59 log10 and 0.96 log10 for Alfa, Gamma, Delta, and Mu variants (p≤0.0007), respectively. No differences were observed for the D614G strain. Real-time PCR assay exhibited titers ranging from 0.39 ± 0.001×108 to 3.38 ± 0.04×108 RNA copies/µL for all variants. The relation between PFU/mL and RNA copies/mL was 1:29800 for D614G strain, 1:11700 for Alpha, 1:8930 for Gamma, 1:12500 for Delta, and 1:2950 for Mu. Conclusion: TCID50 assay was comparable to plaque assay for D614G but not for others SARS-CoV-2 variants. Our data demonstrated a correlation among PFU/mL and E gene RNA copies/µL, units of measure commonly used to quantify the viral load in diagnostic and research fields. The results suggest that the proportion of infectious virions in vitro changes depending on the SARS-CoV-2 variant, being Mu, the variant reaching a higher viral titer with fewer viral copies.

The Antiviral and Virucidal Activities of Voacangine and Structural Analogs Extracted from Tabernaemontana cymosa Depend on the Dengue Virus Strain.

Currently, no specific licensed antiviral exists for treating the illness caused by dengue virus (DENV). Therefore, the search for compounds of natural origin with antiviral activity is an important area of research. In the present study, three compounds were isolated and identified from seeds of Tabernaemontana cymosa plants. The in vitro antiviral effect of those compounds and voacangine against different DENV strains was assessed using different experimental approaches: compounds added before the infection (Pre), at the same time with the virus (Trans), after the infection (Post) or compounds present in all moments of the experiment (Pre-Trans-Post, Combined treatment). In silico studies (docking and molecular dynamics) were also performed to explain the possible antiviral mechanisms. The identified compounds were three structural analogs of voacangine (voacangine-7-hydroxyindolenine, rupicoline and 3-oxo-voacangine). In the Pre-treatment, only voacangine-7-hydroxyindolenine and rupicoline inhibited the infection caused by the DENV-2/NG strain (16.4% and 29.6% infection, respectively). In the Trans-treatment approach, voacangine, voacangine-7-hydroxyindolenine and rupicoline inhibited the infection in both DENV-2/NG (11.2%, 80.4% and 75.7% infection, respectively) and DENV-2/16681 infection models (73.7%, 74.0% and 75.3% infection, respectively). The latter strain was also inhibited by 3-oxo-voacangine (82.8% infection). Moreover, voacangine (most effective virucidal agent) was also effective against one strain of DENV-1 (DENV-1/WestPac/74) and against the third strain of DENV-2 (DENV-2/S16803) (48.5% and 32.4% infection, respectively). Conversely, no inhibition was observed in the post-treatment approach. The last approach (combined) showed that voacangine, voacangine-7-hydroxyindolenine and rupicoline inhibited over 90% of infections (3.5%, 6.9% and 3.5% infection, respectively) of both strains (DENV-2/NG and DENV-2/16681). The free energy of binding obtained with an in silico approach was favorable for the E protein and compounds, which ranged between -5.1 and -6.3 kcal/mol. Finally, the complex formed between DENV-2 E protein and the best virucidal compound was stable for 50 ns. Our results show that the antiviral effect of indole alkaloids derived from T. cymose depends on the serotype and the virus strain.