MDRO account for nearly one-third of BSI in cirrhotic patients, often resulting in delayed or inadequate empirical antimicrobial therapy and increased mortality rates. Our data suggest that improved prevention and treatment strategies for MDRO are urgently needed in the liver cirrhosis patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the pandemic Coronavirus Disease 2019 (COVID-19). This virus is highly transmissible among individuals through both droplets and aerosol leading to determine severe pneumonia. Among the various factors that can influence both the onset of disease and the severity of its complications, the microbiome composition has also been investigated. Recent evidence showed the possible relationship between gut, lung, nasopharyngeal, or oral microbiome and COVID-19, but very little is known about it. Therefore, we aimed to verify the relationships between nasopharyngeal microbiome and the development of either COVID-19 or the severity of symptoms. To this purpose, we analyzed, by next generation sequencing, the hypervariable V1-V2-V3 regions of the bacterial 16S rRNA in nasopharyngeal swabs from SARS-CoV-2 infected patients (n=18) and control (CO) individuals (n=12) using Microbiota solution A (Arrow Diagnostics). We found a significant lower abundance of Proteobacteria and Fusobacteria in COVID-19 patients in respect to CO (p=0.003 and p<0.0001, respectively) from the phylum up to the genus (p<0.001). The Fusobacterium periodonticum (FP) resulted as the most significantly reduced species in COVID-19 patients respect to CO. FP is reported as being able to perform the surface sialylation. Noteworthy, some sialic acids residues on the cell surface could work as additional S protein of SARS-CoV-2 receptors. Consequently, SARS-CoV-2 could use sialic acids as receptors to bind to the epithelium of the respiratory tract, promoting its clustering and the disease development. We can therefore speculate that the significant reduction of FP in COVID-19 patients could be directly or indirectly linked to the modulation of sialic acid metabolism. Finally, viral or environmental factors capable of interfering with sialic metabolism could determine a fall in the individual protection from SARS-CoV-2. Further studies are necessary to clarify the precise role of FP in COVID-19.

Background Tocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. Methods A multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival. Results In the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6–24.0, P = 0.52) and 22.4% (97.5% CI: 17.2–28.3, P < 0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Conclusions Tocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline. Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092).

Hepatitis C virus (HCV) infection is one of the main causes of liver disease worldwide. Its treatment is currently based on the combination of peg-interferon, ribavirin, and, for patients with genotype 1, a protease inhibitor (telaprevir or boceprevir). However, interferon-based combinations are not effective in all patients. Moreover, they are contraindicated in patients who cannot receive interferon (e.g. those with decompensated cirrhosis), and are frequently associated with adverse events. Consequently, there is a need to develop new drugs to treat HCV infection. This review focuses on preclinical and clinical data regarding sofosbuvir (GS-7977), a uridine nucleotide analogue inhibitor of HCV NS5 B polymerase that is effective against HCV genotypes 1,2, 3,4 and 6. Thanks to its excellent pharmacokinetic profile, sofosbuvir can be administered in an oral single daily dose. In vitro it exerts a potent antiviral effect against HCV. Clinical data show that combined with peg-interferon and ribavirin for 12 weeks it yields SVR of about 90% in subjects with HCV genotype 1 and about 100% in patients with HCV genotype 2 or 3. Moreover, sofosbuvir and ribavirin administered for 12 weeks yield similar high SVR rate (84% for genotype 1 and 100% for genotype 2/3 patients) as well as sofosbuvir and daclatasvir (an inhibitor of NS5A) which produce SVR rate of about 100% regardless of genotype or of ribavirin employment. Safety and tolerability of sofosbuvir appear to be excellent. In conclusion, sofosbuvir especially in interferon-free combinations represents a very promising option in the treatment of chronic hepatitis C.

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SUMMARYWe present a systematic non-linear analysis of di erential voltage controlled oscillators (VCOs), both bipolar and MOS. Using the standard device models, we derive the second-order non-linear equation describing the behaviour of these oscillators, which is formulated in a perturbation form. The solution of this equation is obtained as a particular case of the solution of the most general equation of second-order oscillators, which is solved through a suitable perturbation method. Unlike a pure numerical analysis, simple analytical relationships are derived for predicting the steady-state oscillation, its transient behaviour and for ascertaining the existence of a stable oscillation in di erential VCOs. These relationships, leading to results which well agree with the SPICE simulations, are useful in both analysis and design.

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