Influence of Sapindus mukorossi extract in comparison to 17% EDTA as final root canal irrigant on the sealer penetration and microleakage of dentinal tubules.

OBJECTIVE: The study evaluated the effect of Sapindus mukorossi (SM) extract as a final root canal irrigant on sealer penetration (SP) in dentinal tubules and microleakage. MATERIALS AND METHODS: Samples were selected based on inclusion and exclusion criteria. An access opening in all samples was performed and the working length was decided using pro taper for canal finishing along with constant irrigation. Specimens were randomly divided into 3 groups. Group 1 was irrigated with 3 ml of 17% EDTA; group 2 was irrigated with SM irrigant and group 3 samples were irrigated with 0.9% saline. After obturation, samples were vertically placed in 1% methylene blue dye cut in half longitudinally, and viewed under a stereomicroscope. Analysis of SP in the dentinal tubule was assessed using scanning electron microscopy (SEM). For microleakage assessment, mean and standard deviation were reported and One-Way ANOVA was applied. SP was compared using Kruskal-Wallis' test. For inspecting the interaction between SM/EDTA and NaOCl, Fisher's exact test was applied. No statistically significant difference between microleakage in any of the tested groups was observed. The control group showed minimum leakage as compared to EDTA and SM. RESULTS: The results displayed that there was no significant difference, (p=0.67), between dentinal tubule SP at 2 mm. A significant difference between dentinal tubule SP among groups at 5 mm was observed (p<0.05). CONCLUSIONS: SM ethanolic extract showed comparable outcomes of smear layer removal and sealer penetration to 17% EDTA, as a final irrigant in root canal cleaning. Therefore, SM has the potential to be used as an adjuvant final irrigant in conjunction with NaOCl.

Reduced Mortality among COVID-19 ICU Patients after Treatment with HemoClear Convalescent Plasma in Suriname.

Convalescent plasma is a promising therapy for coronavirus disease 2019 (COVID-19), but its efficacy in intensive care unit (ICU) patients in low- and middle-income country settings such as Suriname is unknown. Bedside plasma separation using the HemoClear device made convalescent plasma therapy accessible as a treatment option in Suriname. Two hundred patients with severe SARS-CoV-2 infection requiring intensive care were recruited. Fifty eight patients (29%) received COVID-19 convalescent plasma (CCP) treatment in addition to standard of care (SOC). The CCP treatment and SOC groups were matched by age, sex, and disease severity scores. Mortality in the CCP treatment group was significantly lower than that in the SOC group (21% versus 39%; Fisher's exact test P = 0.0133). Multivariate analysis using ICU days showed that CCP treatment reduced mortality (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.18 to 0.66; P = 0.001), while complication of acute renal failure (creatinine levels, >110 mol/L; HR, 4.45; 95% CI, 2.54 to 7.80; P < 0.0001) was independently associated with death. Decrease in chest X-ray score in the CCP treatment group (median -3 points, interquartile range [IQR] -4 to -1) was significantly greater than that in the SOC group (median -1 point, IQR -3 to 1, Mann-Whitney test P = 0.0004). Improvement in the PaO2/FiO2 ratio was also significantly greater in the CCP treatment group (median 83, IQR 8 to 140) than in the SOC group (median 35, IQR -3 to 92, Mann-Whitney P = 0.0234). Further research is needed for HemoClear-produced CCP as a therapy for SARS-CoV-2 infection together with adequately powered, randomized controlled trials. IMPORTANCE This study compares mortality and other endpoints between intensive care unit COVID-19 patients treated with convalescent plasma plus standard of care (CCP), and a control group of patients hospitalized in the same medical ICU facility treated with standard of care alone (SOC) in a low- and middle-income country (LMIC) setting using bedside donor whole blood separation by gravity (HemoClear) to produce the CCP. It demonstrates a significant 65% survival improvement in HemoClear-produced CCP recipients (HR, 0.35; 95% CI, 0.19 to 0.66; P = 0.001). Although this is an exploratory study, it clearly shows the benefit of using the HemoClear-produced CCP in ICU patients in the Suriname LMIC setting. Additional studies could further substantiate our findings and their applicability for both LMICs and high-income countries and the use of CCP as a prepared readiness method to combat new viral pandemics.

Studies on the succinate dehydrogenating system. Interaction of the mitochondrial succinate-ubiquinone reductase with pyridoxal phosphate.

The inhibitory effect of pyridoxal phosphate on the Triton X-100 solubilized purified bovine heart succinate-ubiquinone reductase (Choudhry, Z.M., Gavrikova, E.V., Kotlyar, A.B., Tushurashvilli, P.R. and Vinogradov, A.D. (1985) FEBS Lett. 182, 171-175) was studied. The kinetics of the enzyme inactivation by pyridoxal phosphate was found to be strongly dependent both qualitatively and quantitatively on the concentration of the protein-detergent complexes. In the diluted system the inactivation of the ubiquinone-depleted enzyme was completely prevented by the saturating concentrations of Q2, carboxin, thenoiltrifluoroacetone and pentachlorophenol, i.e., by the substrate and specific inhibitors of the enzyme. The protective effects of Q2 and the inhibitors was employed to quantitate the affinities of the ligands to their specific binding sites. Strong difference in the affinity of Q2 to the reduced and oxidized enzyme was found. When the soluble reconstitutively active succinate dehydrogenase was treated with pyridoxal phosphate, the reactivity of the enzyme towards low ferricyanide concentrations and its reconstitutive activity was significantly protected against aerobic inactivation.

Pyridoxal phosphate-induced dissociation of the succinate: ubiquinone reductase.

Treatment of the soluble ubiquinone-deficient succinate: ubiquinone reductase with pyridoxal phosphate results in the inhibition of the carboxin-sensitive ubiquinone-reductase activity of the enzyme. The inactivation is prevented by the soluble homolog of ubiquinone (Q2) but is insensitive to the dicarboxylates interacting with the substrate binding site of succinate dehydrogenase. The reactivity of the pyridoxal phosphate-inhibited enzyme with different electron acceptors suggests that the observed inhibition is due to the dissociation of succinate dehydrogenase from the enzyme complex. The soluble succinate dehydrogenase was recovered in the supernatant after treatment of the insoluble succinate: ubiquinone reductase with pyridoxal phosphate. The data obtained strongly suggest the participation of amino groups in the interaction between succinate dehydrogenase and the ubiquinone reactivity conferring peptide within the complex.