UNASSIGNED: Blastocystis is a common enteric parasite, having a worldwide distribution. Many antimicrobial agents are effective against it, yet side effects and drug resistance have been reported. Thus, ongoing trials are being conducted for exploring anti-Blastocystis alternatives. Proteases are attractive anti-protozoal drug targets, having documented roles in Blastocystis. Serine proteases are present in both hepatitis C virus and Blastocystis. Since drug repositioning is quite trendy, the in vitro efficacy of simeprevir (SMV), an anti-hepatitis serine protease inhibitor, against Blastocystis was investigated in the current study.
UNASSIGNED: Stool samples were collected from patients, Alexandria, Egypt. Concentrated stools were screened using direct smears, trichrome, and modified Ziehl-Neelsen stains to exclude parasitic co-infections. Positive stool isolates were cultivated, molecularly subtyped for assessing the efficacy of three SMV doses (100,150, and 200 μg/ml) along 72 hours (h), on the most common subtype, through monitoring parasite growth, viability, re-culture, and also via ultrastructure verification. The most efficient dose and duration were later tested on other subtypes.
UNASSIGNED: Results revealed that Blastocystis was detected in 54.17% of examined samples. Molecularly, ST3 predominated (62%), followed by ST1 (8.6%) and ST2 (3.4%). Ascending concentrations of SMV progressively inhibited growth, viability, and re-culture of treated Blastocystis, with a non-statistically significant difference when compared to the therapeutic control metronidazole (MTZ). The most efficient dose and duration against ST3 was 150 µg/ml for 72 h. This dose inhibited the growth of ST3, ST1, and ST2 with percentages of 95.19%, 94.83%, and 94.74%, successively and viability with percentages of 98.30%, 98.09%, and 97.96%, successively. This dose abolished Blastocystis upon re-culturing. Ultra-structurally, SMV induced rupture of Blastocystis cell membrane leading to necrotic death, versus the reported apoptotic death caused by MTZ. In conclusion, 150 µg/ml SMV for 72 h proved its efficacy against ST1, ST2, and ST3 Blastocystis, thus sparing the need for pre-treatment molecular subtyping in developing countries.

UNASSIGNED: The incidence of hepatocellular carcinoma (HCC) decreases significantly in chronic hepatitis C (CHC) patients with sustained virologic response (SVR) after pegylated-interferon plus ribavirin (PR) or direct-acting antiviral (DAAs) therapy. We follow-up a single cohort of CHC patients to identify risk factors associated with HCC development post-SVR.
UNASSIGNED: CHC patients with SVR in Beijing/Hong Kong were followed up at 12-24 weekly intervals with surveillance for HCC by ultrasonography and alpha-fetoprotein (AFP). Multivariate Cox proportional hazards regression analysis was used to explore factors associated with HCC occurrence.
UNASSIGNED: Between October 2015 and May 2017, SVR was observed in 519 and 817 CHC patients after DAAs and PR therapy respectively. After a median post -SVR follow-up of 48 months, HCC developed in 54 (4.4%) SVR subjects. By adjusted Cox analysis, older age (≥55 years) [HR 2.4, 95% CI (1.3-4.3)], non-alcoholic fatty liver diseases [HR 2.4, 95%CI (1.3-4.2), higher AFP level (≥20 ng/ml) [HR 3.4, 95%CI (2.0-5.8)], higher liver stiffness measurement (≥14.6 kPa) [HR 4.2, 95%CI (2.3-7.6)], diabetes mellitus [HR 4.2, 95%CI (2.4-7.4)] at pre-treatment were associated with HCC occurrence. HCC patients in the DAAs induced SVR group had a higher prevalence of NAFLD as compared with those in the PR induced SVR group, 62% (18/29) vs 28% (7/25), p = 0.026. A nomogram formulated with the above six independent variables had a Concordance-Index of 0.835 (95% CI 0.783-0.866).
UNASSIGNED: Underlying NAFLD is associated with increased incidence of HCC in chronic HCV patients post-SVR, particularly in those treated with DAA.

The high mortality rate from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in humans and the lack of effective therapeutic regime for its treatment necessitates the identification of new antivirals. SARS-CoV-2 relies on non-structural proteins such as Nsp13 helicase and nsp14 which are the key components of the replication-transcription complex (RTC) to complete its infectious life cycle. Therefore, targeting these essential viral proteins with small molecules will most likely to halt the disease pathogenesis. The lack of experimental structures of these proteins deters the process of structure-based identification of their specific inhibitors. In the present study, the in silico models of SARS-CoV-2 nsp13 helicase and nsp14 protein were elucidated using a comparative homology modelling approach. These in silico model structures were validated using various parameters such as Ramachandran plot, Verify 3D score, ERRAT score, knowledge-based energy and Z-score. The in silico models were further used for virtual screening of the Food and Drug Administration (FDA) approved antiviral drugs. Simeprevir (SMV), Paritaprevir (PTV) and Grazoprevir (GZR) were the common leads identified which show higher binding affinity to both nsp13 helicase and nsp14 as compared to the control inhibitors and therefore, they might be potential dual-target inhibitors. The leads also establish a network of hydrogen bonds and hydrophobic interactions with the key residues lining the active site pockets. The present findings suggest that these FDA approved antiviral drugs can be subjected to repurposing against SARS-CoV-2 infection after verifying the in silico results through in vitro and in vivo studies.

Treatment of hepatitis C virus (HCV) with newer directly acting antivirals (DAAs) and lead to sustained viral response (SVR) in majority of patients and SVR has been documented to be associated with reversal of liver cirrhosis. The improved SVR rates and safety profiles of DAAs have led to the treatment of patients with decompensated cirrhosis awaiting liver transplantation (LT). Several clinical trials of DAAs in decompensated HCV patients have recently demonstrated SVR rates above 80%, which have been associated with significant improvements, in the Child-Pugh-Turcotte scores/or model for end-stage liver disease scores in a proportion of patients. Moreover, it has been shown that HCV RNA becomes negative after 2-4 weeks of treatment, and those who are transplanted after becoming HCV RNA negative will be have very low the risk of HCV recurrence after transplantation. Some of the patients may have reached the \"point of no return\" and may proceed to worsening of decomposition over time. To avoid the risk of worsening, there is an additional option of treating these patients after LT should they develop recurrent HCV infection. Currently there are no guidelines as to select patients who would benefit from treatment prior to LT as opposed to those who will be better off being treated after the transplant surgery. The article discusses a possible approach for such selection.