A Calcium- and GTP-Dependent Transglutaminase in Leishmania infantum

While human and animal leishmaniasis affect several millions of people worldwide, L. infantum is the species responsible for visceral leishmaniasis in Europe, Middle East, and America. Antileishmanial drugs present issues associated with drug toxicity and increasing parasite resistance. Therefore, the study of this parasite with a focus on new potential drug targets is extremely useful. Accordingly, we purified and characterized a transglutaminase (TGase) from L. infantum promastigotes. While Tgases are known to be involved in cell death and autophagy, it appears that these functions are very important for parasites' virulence. For the first time, we showed a Ca2+- and GTP-dependent TGase in Leishmania corresponding to a 54 kDa protein, which was purified by two chromatographic steps: DEAE-Sepharose and Heparin-Sepharose. Using polyclonal antibodies against a 50-amino-acid conserved region of the catalytic core of human TGase 2, we revealed two other bands of 66 and 75 kDa. The 54 kDa band appears to be different from the previously reported TGase, which was shown to be Ca2+- independent. Future research should address the identification of the purified enzyme sequence and, subsequently, its cloning to more comprehensively investigate its pathophysiological function and possible differences from mammal enzymes

Predictive Factors of Surgical Site Infection in Prosthetic Joint Surgery: A Prospective Study on 760 Arthroplasties

Purpose. The success of total joint arthroplasty (TJA) has led to consistent growth in the use of arthroplasty in progressivelyyounger patients. However, more than 10 percent of patients require revision surgery due to implant failure caused by asepticor septic inflammation. Among the latter, surgical site infection (SSI) represents one of the worst complications of TJA,potentially resulting in the removal of the prosthesis. The aim of our study was to identify potential risk factors for SSIs in apopulation of patients undergoing TJA. Methods. TJA were prospectively recruited at Casa di Cura Santa Maria Maddalenafrom February 2019 to April 2020. Age, sex, major comorbidities, American Society of Anesthesiologists (ASA) class, length ofsurgery, type of surgical suture, total hospital length of stay, and clinical laboratory data were collected. The study populationwas then divided into two groups: Group A, normal postoperative course, and Group B, patients who developed SSI at follow-up (17-25 days). Results. 25/760 (3.3%) patients developed SSIs at follow-up. Clinical and demographic parameters were notdifferent between the two groups. Total leucocyte and neutrophil values at discharge resulted to be significatively higher inGroup B compared to Group A (p = 0:025 and p = 0:016, respectively). Values of 7860/μL for total leucocyte and 5185/μL forneutrophil count at discharge significantly predicted the future development of SSI (AUC 0.623 and AUC 0.641, respectively; p< 0:05) independently from confounding factors (total leukocytes: O:R: = 3, 69 [95% C.I. 1,63-8,32]; neutrophils: O:R: = 3, 98[95% C.I. 1,76-8,97]). Deep SSIs has been diagnosed significantly before superficial SSIs (p = 0,008), with a median advance of9 days. Conclusion. Total leukocytes and neutrophils at discharge seem useful to identify a population at risk for thedevelopment of septic inflammation at the surgical site following TJA. Further studies with larger populations are needed to develop a predictive SSIs risk score that should include those variables

Nanostructured modifications of titanium surfaces improve vascular regenerative properties of exosomes derived from mesenchymal stem cells: Preliminary in vitro results

© 2021 by the authors. Licensee MDPI, Basel, Switzerland.(1) Background: Implantation of metal-based scaffolds is a common procedure for treating several diseases. However, the success of the long-term application is limited by an insufficient endothelialization of the material surface. Nanostructured modifications of metal scaffolds represent a promising approach to faster biomaterial osteointegration through increasing of endothelial commitment of the mesenchymal stem cells (MSC). (2) Methods: Three different nanotubular Ti surfaces (TNs manufactured by electrochemical anodization with diameters of 25, 80, or 140 nm) were seeded with human MSCs (hMSCs) and their exosomes were isolated and tested with human umbilical vein endothelial cells (HUVECs) to assess whether TNs can influence the secretory functions of hMSCs and whether these in turn affect endothelial and osteogenic cell activities in vitro. (3) Results: The hMSCs adhered on all TNs and significantly expressed angiogenic-related factors after 7 days of culture when compared to untreated Ti substrates. Nanomodifications of Ti surfaces significantly improved the release of hMSCs exosomes, having dimensions below 100 nm and expressing CD63 and CD81 surface markers. These hMSC-derived exosomes were efficiently internalized by HUVECs, promoting their migration and differentiation. In addition, they selectively released a panel of miRNAs directly or indirectly related to angiogenesis. (4) Conclusions: Preconditioning of hMSCs on TNs induced elevated exosomes secretion that stimulated in vitro endothelial and cell activity, which might improve in vivo angiogenesis, supporting faster scaffold integration

Mitochondrial Metabolism and EV Cargo of Endothelial Cells Is Affected in Presence of EVs Derived from MSCs on Which HIF Is Activated

Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) have attracted growing interest as a possible novel therapeutic agent for the management of different cardiovascular diseases (CVDs). Hypoxia significantly enhances the secretion of angiogenic mediators from MSCs as well as sEVs. The iron-chelating deferoxamine mesylate (DFO) is a stabilizer of hypoxia-inducible factor 1 and consequently used as a substitute for environmental hypoxia. The improved regenerative potential of DFO-treated MSCs has been attributed to the increased release of angiogenic factors, but whether this effect is also mediated by the secreted sEVs has not yet been investigated. In this study, we treated adipose-derived stem cells (ASCs) with a nontoxic dose of DFO to harvest sEVs (DFO-sEVs). Human umbilical vein endothelial cells (HUVECs) treated with DFO-sEVs underwent mRNA sequencing and miRNA profiling of sEV cargo (HUVEC-sEVs). The transcriptomes revealed the upregulation of mitochondrial genes linked to oxidative phosphorylation. Functional enrichment analysis on miRNAs of HUVEC-sEVs showed a connection with the signaling pathways of cell proliferation and angiogenesis. In conclusion, mesenchymal cells treated with DFO release sEVs that induce in the recipient endothelial cells molecular pathways and biological processes strongly linked to proliferation and angiogenesis

Vaginal Lactoferrin Modulates PGE 2

Inflammation plays an important role in pregnancy, and cytokine and matrix metalloproteases (MMPs) imbalance has been associated with premature rupture of membranes and increased risk of preterm delivery. Previous studies have demonstrated that lactoferrin (LF), an iron-binding protein with anti-inflammatory properties, is able to decrease amniotic fluid (AF) levels of IL-6. Therefore, we aimed to evaluate the effect of vaginal LF administration on amniotic fluid PGE2 level and MMP-TIMP system in women undergoing genetic amniocentesis. One hundred and eleven women were randomly divided into controls (n = 57) or treated with LF 4 hours before amniocentesis (n = 54). Amniotic fluid PGE2, active MMP-9 and MMP-2, and TIMP-1 and TIMP-2 concentrations were determined by commercially available assays and the values were normalized by AF creatinine concentration. PGE2, active MMP-9, and its inhibitor TIMP-1 were lower in LF-treated group than in controls (p < 0.01, p < 0.005, and p < 0.001, resp.). Conversely, active MMP-2 (p < 0.0001) and MMP-2/TIMP-2 molar ratio (p < 0.001) were increased, whilst TIMP-2 was unchanged. Our data suggest that LF administration is able to modulate the inflammatory response following amniocentesis, which may counteract cytokine and prostanoid imbalance that leads to abortion. This trial is registered with Clinical Trial number NCT02695563

In Vitro Model for the Evaluation of Innovative Transcatheter Debridement Device (TDD): Pericardium-Based Scaffold and Stem Cells to Reproduce Calcificated Valves

: Aortic valve stenosis has become the most common valvular disease in elderly patients. Several treatments are available such as surgical aortic valve replacement and transcatheter aortic valve implantation. To date, however, there is a need to discover alternative treatments that can delay the disease progression and, therefore, the implant of a prosthetic valve. In this regard, a decalcification procedure based on the use of ultrasonic waves could represent an innovative solution in transcatheter cardiovascular therapies. In this article, we describe an innovative transcatheter debridement device (TDD) that uses low-intensity ultrasound shock waves for calcium ablation from the native aortic valve and bioprosthetic valve. Mesenchymal stem cells were seeded onto pericardium-based scaffolds and committed into an osteogenic phenotype. After treatment with TDD, cell proliferation was analyzed, as well as lactate dehydrogenase release and cell morphology. The release of calcium and inflammation events were detected. The results confirmed that the TDD was able to induce a safe decalcification without any adverse inflammatory events

Acute Prosthetic Joint Infections with Poor Outcome Caused by Staphylococcus Aureus Strains Producing the Panton-Valentine Leukocidin

The aim of this study was to investigate whether the presence of Staphylococcus aureus (SA) producing the Panton-Valentine leukocidin (PVL) affects the outcome of Prosthetic Joint Infection (PJI). Patients with acute and chronic PJI sustained by SA were prospectively enrolled at the orthopedic unit of "Casa di Cura Santa Maria Maddalena", from January 2019 to October 2021. PJI diagnosis was reached according to the diagnostic criteria of the International Consensus Meeting on PJI of Philadelphia. Synovial fluid obtained via joint aspirations was collected in order to isolate SA. The detection of PVL was performed via real-time quantitative PCR (RT-qPCR). The outcome assessment was performed using the criteria of the Delphi-based International Multidisciplinary Consensus. Twelve cases of PJI caused by SA were included. Nine (75%) cases were acute PJI treated using debridement, antibiotic and implant retention (DAIR); the remaining three (25%) were chronic PJI treated using two-stage (n = 2) and one-stage revision (n = 1), respectively. The SA strains that tested positive for PVL genes were 5/12 (41.6%,). Treatment failure was documented in three cases of acute PJI treated using DAIR, all supported by SA-PVL strains (p &lt; 0.045). The remaining two cases were chronic PJI treated with a revision arthroplasty (one and two stage, respectively), with a 100% eradication rate in a medium follow-up of 24 months. Although a small case series, our study showed a 100% failure rate in acute PJI, probably caused by SA PVL-producing strains treated conservatively (p &lt; 0.04). In this setting, toxin research should guide radical surgical treatment and targeted antibiotic therapy

Co-circulation of SARS-CoV-2 Alpha and Gamma variants in Italy, February and March 2021

: BackgroundSeveral SARS-CoV-2 variants of concern (VOC) have emerged through 2020 and 2021. There is need for tools to estimate the relative transmissibility of emerging variants of SARS-CoV-2 with respect to circulating strains.AimWe aimed to assess the prevalence of co-circulating VOC in Italy and estimate their relative transmissibility.MethodsWe conducted two genomic surveillance surveys on 18 February and 18 March 2021 across the whole Italian territory covering 3,243 clinical samples and developed a mathematical model that describes the dynamics of co-circulating strains.ResultsThe Alpha variant was already dominant on 18 February in a majority of regions/autonomous provinces (national prevalence: 54%) and almost completely replaced historical lineages by 18 March (dominant across Italy, national prevalence: 86%). We found a substantial proportion of the Gamma variant on 18 February, almost exclusively in central Italy (prevalence: 19%), which remained similar on 18 March. Nationally, the mean relative transmissibility of Alpha ranged at 1.55-1.57 times the level of historical lineages (95% CrI: 1.45-1.66). The relative transmissibility of Gamma varied according to the assumed degree of cross-protection from infection with other lineages and ranged from 1.12 (95% CrI: 1.03-1.23) with complete immune evasion to 1.39 (95% CrI: 1.26-1.56) for complete cross-protection.ConclusionWe assessed the relative advantage of competing viral strains, using a mathematical model assuming different degrees of cross-protection. We found substantial co-circulation of Alpha and Gamma in Italy. Gamma was not able to outcompete Alpha, probably because of its lower transmissibility

Increasing situational awareness through nowcasting of the reproduction number

The time varying reproduction number R is a critical variable for situational awareness during infectious disease outbreaks, but delays between infection and reporting hinder its accurate estimation in real time. We propose a nowcasting method for improving the timeliness and accuracy of R estimates, based on comparisons of successive versions of surveillance databases. The method was validated against COVID-19 surveillance data collected in Italy over an 18-month period. Compared to traditional methods, the nowcasted reproduction number reduced the estimation delay from 13 to 8 days, while maintaining a better accuracy. Moreover, it allowed anticipating the detection of periods of epidemic growth by between 6 and 23 days. The method offers a simple and generally applicable tool to improve situational awareness during an epidemic outbreak, allowing for informed public health response planning