Hydrazones and Thiosemicarbazones Targeting Protein-Protein-Interactions of SARS-CoV-2 Papain-like Protease

The papain-like protease (PLpro) of SARS-CoV-2 is essential for viral propagation and, additionally, dysregulation of the host innate immune system. Using a library of 40 potential metal-chelating compounds we performed an X-ray crystallographic screening against PLpro. As outcome we identified six compounds binding to the target protein. Here we describe the interaction of one hydrazone (H1) and five thiosemicarbazone (T1-T5) compounds with the two distinct natural substrate binding sites of PLpro for ubiquitin and ISG15. H1 binds to a polar groove at the S1 binding site by forming several hydrogen bonds with PLpro. T1-T5 bind into a deep pocket close to the polyubiquitin and ISG15 binding site S2. Their interactions are mainly mediated by multiple hydrogen bonds and further hydrophobic interactions. In particular compound H1 interferes with natural substrate binding by sterical hindrance and induces conformational changes in protein residues involved in substrate binding, while compounds T1-T5 could have a more indirect effect. Fluorescence based enzyme activity assay and complementary thermal stability analysis reveal only weak inhibition properties in the high micromolar range thereby indicating the need for compound optimization. Nevertheless, the unique binding properties involving strong hydrogen bonding and the various options for structural optimization make the compounds ideal lead structures. In combination with the inexpensive and undemanding synthesis, the reported hydrazone and thiosemicarbazones represent an attractive scaffold for further structure-based development of novel PLpro inhibitors by interrupting protein-protein interactions at the S1 and S2 site

The Fatty Liver Index: a simple and accurate predictor of hepatic steatosis in the general population

BACKGROUND: Fatty liver (FL) is the most frequent liver disease in Western countries. We used data from the Dionysos Nutrition & Liver Study to develop a simple algorithm for the prediction of FL in the general population. METHODS: 216 subjects with and 280 without suspected liver disease were studied. FL was diagnosed by ultrasonography and alcohol intake was assessed using a 7-day diary. Bootstrapped stepwise logistic regression was used to identify potential predictors of FL among 13 variables of interest [gender, age, ethanol intake, alanine transaminase, aspartate transaminase, gamma-glutamyl-transferase (GGT), body mass index (BMI), waist circumference, sum of 4 skinfolds, glucose, insulin, triglycerides, and cholesterol]. Potential predictors were entered into stepwise logistic regression models with the aim of obtaining the most simple and accurate algorithm for the prediction of FL. RESULTS: An algorithm based on BMI, waist circumference, triglycerides and GGT had an accuracy of 0.84 (95%CI 0.81–0.87) in detecting FL. We used this algorithm to develop the "fatty liver index" (FLI), which varies between 0 and 100. A FLI < 30 (negative likelihood ratio = 0.2) rules out and a FLI ≥ 60 (positive likelihood ratio = 4.3) rules in fatty liver. CONCLUSION: FLI is simple to obtain and may help physicians select subjects for liver ultrasonography and intensified lifestyle counseling, and researchers to select patients for epidemiologic studies. Validation of FLI in external populations is needed before it can be employed for these purposes

Enhancement of in-vitro activity of ofloxacin and gentamicin by rat serum

Normal rat serum shows antibacterial activity because of the presence of endogenous substances. The aim of this research was to study some aspects of the interaction between this biological fluid and some antibiotics, in order to demonstrate possible synergistic activity. Serum is able to lower the minimum inhibitory concentration of gentamicin and ofloxacin against some Gram-negative microorganisms. This can be explained by the presence of lysozyme, antibodies, beta-lysin and other complementary factors that are able to cooperate with these antibiotics

From target to reality: barriers and policy implications for bioenergy in Italy

This paper represents the position, in the Italian bioenergy framework, of the Federation of Renewable Energy Suppliers (FIPER), which currently includes 90 district heating (DH) plants powered by wood biomass (almost the 90% of Italian plants) and 129 plants of biogas production from agriculture and zoo-technical products Fiper promotes the exploitation of bioenergy in Italy through a sustainable land management, considering also the impact on employment. According to the European targets, Fiper suggests to enhance the contribution of bioenergy for thermal uses in Italy and to reconsider issues underestimated by the national plans and rules, e.g. the increase in cooling demand and the potentiality of efficient biomass DH systems. Fiper has defined measures for promoting efficient DH in harmony with the path towards 100% renewable energy systems and coherently to the economic reality, including a method for ensuring a sustainable and cost-effective use of biomass

Bleeding Jejunal Diverticulum

An 81-year-old man was referred because of severe iron deficiency anemia and episodes of melena. Despite several hospitalizations for this problem, a definitive diagnosis had not been made. Upper endoscopy and colonoscopy were negative, and an enteroclysis study revealed only jejunal diverticula (A). Tagged-red-blood-cell scintigraphy was positive for a bleeding site in the proximal gut, but the finding was not considered by the consulting surgeon as a sufficient indication for operation. At enteroscopy, a blood clot adherent to a jejunal diverticulum was found (B). Laparotomy revealed intestinal loops full of blood from about 40 cm distal to the ligament of Treitz. By using the enteroscopy findings as a guide, a large diverticulum was identified in the jejunum as the probable source of bleeding (C). The intestinal segment containing the diverticulum was resected. The postoperative recovery was uneventful, and, subsequent to discharge, the patient has had no further episodes of bleeding. Full-size image (15K) Full-size image (29K) Full-size image (25K

Effetti avversi gastrointestinali: farmaci anti-infiammatori non steroidei ed Helicobacter pylori

Nonostante i FANS possano determinare il danno alla mucosa, in assenza di H pylori, sembra ovvio, ma spesso \ue8 trascurata, l\u2019evidenza che il danno possa essere aggravato dalla contemporanea presenza di infezione. Ad esempio \ue8 noto che i FANS inibiscono la sintesi di muco gastrico, ne riducono la viscosit\ue0 ed incrementano la retrodiffusione degli ioni idrogeno (1-4). Inoltre, \ue8 stato riportato che, quando si mette in incubazione una cultura di supernatante contenente H pylori, si determina una riduzione della viscosit\ue0 del muco gastrico che, questo, indebolisce, per esempio, la resistenza della mucosa gastrica all\u2019assunzione ripetuta di aspirina, ma che viene ripristinata dopo l\u2019eradicazione (5). Forse un comune concetto errato \ue8 quello per cui H pylori e FANS hanno azione opposta nei confronti della sintesi delle prostaglandine. E\u2019 ormai accertato che presenza di infezione da H pylori attenua il danno gastrico indotto dai FANS attraverso la stimolazione della sintesi delle prostaglandine. L\u2019incremento della sintesi delle prostaglandine associato alla presenza di H pylori pu\uf2 essere considerato come una risposta all\u2019ospite della barriera mucosa infiammata, senza per\uf2 determinare una sostanziale rilevanza clinica dal punto di vista dell\u2019effetto protettivo. Tale concetto \ue8 confermato dal fatto che eradicando l\u2019infezione, l\u2019ulcera peptica guarisce. Inoltre i FANS sopprimono la produzione di prostaglandine a livelli molto bassi indipendentemente dalla presenza dell\u2019Helicobacter. Numerosi sono gli studi avviati sull\u2019argomento negli ultimi anni, ma con risultati, estremamente discordanti. Alcuni autori, infatti, sostengono una loro assoluta indipendenza nello sviluppo della patologia ulcerosa, altri sostengono, al contrario, che infezione da H pylori e FANS abbiano un effetto additivo, altri ancora sostengono che il microrganismo abbia addirittura un effetto protettivo sulla mucosa gastrica dei pazienti che assumono FANS