The role of the single interchains disulfide bond in tetanus and botulinum neurotoxins and the development of antitetanus and antibotulism drugs

A large number of bacterial toxins consist of active and cell binding protomers linked by an interchain disulfide bridge. The largest family of such disulfide-bridged exotoxins is that of the clostridial neurotoxins that consist of two chains and comprise the tetanus neurotoxins causing tetanus and the botulinum neurotoxins causing botulism. Reduction of the interchain disulfide abolishes toxicity, and we discuss the experiments that revealed the role of this structural element in neuronal intoxication. The redox couple thioredoxin reductase-thioredoxin (TrxR-Trx) was identified as the responsible for reduction of this disulfide occurring on the cytosolic surface of synaptic vesicles. We then discuss the very relevant finding that drugs that inhibit TrxR-Trx also prevent botulism. On this basis, we propose that ebselen and PX-12, two TrxR-Trx specific drugs previously used in clinical trials in humans, satisfy all the requirements for clinical tests aiming at evaluating their capacity to effectively counteract human and animal botulism arising from intestinal toxaemias such as infant botulism

Efficacy of lung volume optimization maneuver monitored by optoelectronic pletismography in the management of congenital diaphragmatic hernia

Newborns affected by congenital diaphragmatic hernia (CDH) need cardio-respiratory stabilization before undergoing surgical repair. Open lung strategy is a well-established approach to optimize lung volume in preterm infants with Respiratory Distress Syndrome (RDS), using both High Frequency Oscillatory Ventilation (HFOV) and Conventional Mechanical Ventilation (CMV). We report a case of left CDH with severe lung hypoplasia, managed applying open lung strategy in HFOV (pre-surgery period) and in Assist-Control with Volume Guarantee (post-surgery period), guided by SpO2changes, TcPO2and TcPCO2monitoring. Opto-electronic plethysmography was used to measure end-expiratory chest wall volume changes (ΔEEcw) related to lung volume variations occurring during pressure changes. OEP confirmed the efficacy of using SpO2and transcutaneous gas monitoring during this recruitment maneuver

Meningococcal B vaccine antigen FHbp variants among disease-causing Neisseria meningitidis B isolates, Italy, 2014–2017

Background Typing of Neisseria meningitidis isolates is crucial for the surveillance of invasive meningococcal disease (IMD). We performed a molecular epidemiology study of N. meningitidis serogroup B (MenB) causing IMD in Italy between 2014 and 2017 to describe circulating strains belonging to this serogroup, with particular regards to the two factor H-binding protein (FHbp) subfamilies present in the bivalent MenB vaccine. Materials and methods A total of 109 culture positive and 46 culture negative MenB samples were collected within the National Surveillance System (NSS) of IMD in Italy and molecularly analyzed by conventional methods. Results Overall, 71 MenB samples showed the FHbp subfamily A and 83 the subfamily B. The subfamily variants were differently distributed by age. The most frequent variants, A05 and B231, were associated with cc213 and cc162, respectively. All MenB with the FHbp A05 variant displayed the PorA P1.22,14 and 85.7% of them the FetA F5-5. The majority of MenB with the FHbp B231 variant showed the PorA P1.22,14 (65.4%) and 84.6%, the FetA F3-6. Conclusion MenB circulating in Italy were characterized by a remarkable association between clonal complex and FHbp variants, although a high degree of genetic diversity observed over time. A dynamic trend in clonal complexes distribution within MenB was detected. Our results stress the importance of continued meningococcal molecular surveillance to evaluate the potential vaccine coverage of the available MenB vaccines

Different Dietary Approaches, Non-Alcoholic Fatty Liver Disease and Cardiovascular Disease: A Literature Review

Non-alcoholic fatty liver disease (NAFLD) is the first cause of chronic liver disease and is also associated with other harmful entities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. NAFLD is a significant public health concern worldwide, impacting individuals of all ages, and its prevalence is projected to increase in the near future due to its connection with obesity. Intrinsic (genetics) and external (lifestyle) factors may also modulate NAFLD, and, in turn, may partly explain the observed relationship between NAFLD and cardiovascular disease (CVD). Although many drugs are been tested to treat NAFLD, to date, no drug has indication to specifically treat this disorder. Thus, the current management of NAFLD relies on lifestyle modifications and specifically on weight loss, physical activity, and the intake of a healthy diet. In the present narrative review, we will discuss the effects of certain dietary patterns on NAFLD incidence and progression

A CXCR4 receptor agonist strongly stimulates axonal regeneration after damage

Objective: To test whether the signaling axis CXCL12\u3b1-CXCR4 is activated upon crush/cut of the sciatic nerve and to test the activity of NUCC-390, a new CXCR4 agonist, in promoting nerve recovery from damage. Methods: The sciatic nerve was either crushed or cut. Expression and localization of CXCL12\u3b1 and CXCR4 were evaluated by imaging with specific antibodies. Their functional involvement in nerve regeneration was determined by antibody-neutralization of CXCL12\u3b1, and by the CXCR4 specific antagonist AMD3100, using as quantitative read-out the compound muscle action potential (CMAP). NUCC-390 activity on nerve regeneration was determined by imaging and CMAP recordings. Results: CXCR4 is expressed at the injury site within the axonal compartment, whilst its ligand CXCL12\u3b1 is expressed in Schwann cells. The CXCL12\u3b1-CXCR4 axis is involved in the recovery of neurotransmission of the injured nerve. More importantly, the small molecule NUCC-390 is a strong promoter of the functional and anatomical recovery of the nerve, by acting very similarly to CXCL12\u3b1. This pharmacological action is due to the capability of NUCC-390 to foster elongation of motor neuron axons both in vitro and in vivo. Interpretation: Imaging and electrophysiological data provide novel and compelling evidence that the CXCL12\u3b1-CXCR4 axis is involved in sciatic nerve repair after crush/cut. This makes NUCC-390 a strong candidate molecule to stimulate nerve repair by promoting axonal elongation. We propose this molecule to be tested in other models of neuronal damage, to lay the basis for clinical trials on the efficacy of NUCC-390 in peripheral nerve repair in humans

Comparison of established and emerging biodosimetry assays

Rapid biodosimetry tools are required to assist with triage in the case of a large-scale radiation incident. Here, we aimed to determine the dose-assessment accuracy of the well-established dicentric chromosome assay (DCA) and cytokinesis-block micronucleus assay (CBMN) in comparison to the emerging γ-H2AX foci and gene expression assays for triage mode biodosimetry and radiation injury assessment. Coded blood samples exposed to 10 X-ray doses (240 kVp, 1 Gy/min) of up to 6.4 Gy were sent to participants for dose estimation. Report times were documented for each laboratory and assay. The mean absolute difference (MAD) of estimated doses relative to the true doses was calculated. We also merged doses into binary dose categories of clinical relevance and examined accuracy, sensitivity and specificity of the assays. Dose estimates were reported by the first laboratories within 0.3-0.4 days of receipt of samples for the γ-H2AX and gene expression assays compared to 2.4 and 4 days for the DCA and CBMN assays, respectively. Irrespective of the assay we found a 2.5-4-fold variation of interlaboratory accuracy per assay and lowest MAD values for the DCA assay (0.16 Gy) followed by CBMN (0.34 Gy), gene expression (0.34 Gy) and γ-H2AX (0.45 Gy) foci assay. Binary categories of dose estimates could be discriminated with equal efficiency for all assays, but at doses ≥1.5 Gy a 10% decrease in efficiency was observed for the foci assay, which was still comparable to the CBMN assay. In conclusion, the DCA has been confirmed as the gold standard biodosimetry method, but in situations where speed and throughput are more important than ultimate accuracy, the emerging rapid molecular assays have the potential to become useful triage tools

Efficacy and safety of intravenous paracetamol in comparison to ibuprofen for the treatment of patent ductus arteriosus in preterm infants: Study protocol for a randomized control trial

Background: Patent ductus arteriosus (PDA) is one of most common complications in preterm infants. Although ibuprofen represents the first choice for the closure of PDA, this treatment can cause severe gastrointestinal and adverse renal effects and worsen platelet function. The successful closure of the PDA with paracetamol has been recently reported in several preterm infants, and the safety of paracetamol for this use has been suggested by the available data. Methods/design: We present the design of a randomized, multicenter, controlled study, whose aim is to assess the effectiveness and safety of intravenous paracetamol in comparison to intravenous ibuprofen for the treatment of PDA in preterm infants. A total of 110 infants born at 25 +0 to 31 +6 weeks of gestational age will be enrolled and randomized to receive paracetamol or ibuprofen (55 patients per group) starting at 24-72h of life. The primary endpoint of the study is the comparison of the PDA closing rate observed after a 3-day course with paracetamol or ibuprofen. The secondary endpoints include the closure rate of PDA after the second course of treatment with ibuprofen, the re-opening rate of the PDA, the incidence of surgical ligation, and the occurrence of adverse effects. Discussion: The results of this study will provide new information about the possible use of paracetamol in the treatment of PDA. Paracetamol could offer several important therapeutic advantages over current treatment options, and it could become the treatment of choice for the management of PDA, mainly due to its more favorable side effect profile. Trial registration: Clinicaltrials.gov NCT02422966. Eudract no. 2013-003883-30

A retrospective whole-genome sequencing analysis of carbapenem and colistin-resistant klebsiella pneumoniae nosocomial strains isolated during an MDR surveillance program

Multidrug-resistant Klebsiella pneumoniae (MDR Kp), in particular carbapenem-resistant Kp (CR-Kp), has become endemic in Italy, where alarming data have been reported on the spread of colistin-resistant CR-Kp (CRCR-Kp). During the period 2013–2014, 27 CRCR-Kp nosocomial strains were isolated within the Modena University Hospital Policlinico (MUHP) multidrug resistance surveillance program. We retrospectively investigated these isolates by whole-genome sequencing (WGS) analysis of the resistome, virulome, plasmid content, and core single nucleotide polymorphisms (cSNPs) in order to gain insights into their molecular epidemiology. The in silico WGS analysis of the resistome revealed the presence of genes, such as blaKPC, related to the phenotypically detected resistances to carbapenems. Concerning colistin resistance, the plasmidic genes mcr 1–9 were not detected, while known and new genetic variations in mgrB, phoQ, and pmrB were found. The virulome profile revealed the presence of type-3 fimbriae, capsular polysaccharide, and iron acquisition system genes. The detected plasmid replicons were classified as IncFIB(pQil), IncFIB(K), ColRNAI, IncX3, and IncFII(K) types. The cSNPs genotyping was consistent with the multi locus sequence typing (MLST) and with the distribution of mutations related to colistin resistance genes. In a nosocomial drug resistance surveillance program, WGS proved to be a useful tool for elucidating the spread dynamics of CRCR-Kp nosocomial strains and could help to limit their diffusion

Impacts of citrus pulp addition and wilting on elephant grass silage quality.

The objective of this work was to evaluate the use of citrus pulp addition and wilting on fermentative characteristics, chemical composition as well as gas and effluent losses of elephant grass silage. The elephant grass (70 growth days) was collected manually; one portion was immediately chopped and another one was allowed to wilt in the sun for a period of 6 h and subsequently chopped for the production of silage. Experimental PVC silos (10 cm diameter x 30 cm height) were used and sand bags were placed at the bottom of the silos. Citrus pulp (80 g kg-1 of MN) was added at the beginning of ensilage. The ensiled material was manually compressed to provide a specific mass of approximately 600 kg m-3 of silage. After 60 days, the silos were opened; gas and effluent losses were calculated and we determined pH, dry matter (DM), crude protein(CP), neutral detergent fibre (NDF), lignin, ammonia nitrogen, ash and in vitro dry matter digestibility (IVDMD). We added 0 or 80 g kg-1 of citrus pulp to wilted and un-wilted elephant grass. We used a completely randomised design with a 2 x 2 factorial arrangement (wilted or un-wilted) x (with or without citrus pulp), totalling treatments with five repetitions. Average values were compared using the F test with a probability of 5%. The addition of citrus pulp resulted in reduced levels of NDF, lignin, ash, N-NH3 and pH and in increased values of DM and IVDMD of silages. Wilting increased the DM, NDF and lignin values and reduced the concentrations of CP, IVDMD and N-NH3. Based on our results, citrus pulp addition improves the chemical composition of elephant grass silage and increases its in vitro dry matter digestibility