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OBJECTIVE: Proximal femur fractures are among the most common type of trauma in elderly patients, and Euthyroid sick syndrome has already been related to fractures and trauma. The evidence of a consistent inflammatory state occurring during hip fracture, made us consider as a potential marker also the neutrophil-to-lymphocyte ratio (NLR), which is already in use to measure the prognosis and guide the therapeutic management in various conditions. PATIENTS AND METHODS: A retrospective observational analysis on patients affected by proximal femur fractures was conducted. Patients were divided between affected and non-affected by Euthyroid Sick Syndrome (ESS). Standard follow up was conducted at 1, 3, 6 and 12 months. RESULTS: 79 patients were enrolled in this study. There were 19 males and 60 females, the mean age was 83.8 ± 6.5 y.o., and 44 patients were affected by ESS. Affected patients showed higher NLR values (10.2 ± 9.4 vs. 6.9 ± 3.9; p= 0.001) and higher decrease in fT3 values in the 1st post-operative day (1.8 ± 0.4 vs. 2.2 ± 0.3; p= 0.001), higher values of PTH (97.9 ± 46.2 vs. 70.1 ± 36.2; p=0.004) and lower levels of Vitamin D (18.8 ± 7.8 vs. 23.5 ± 12.9; p=0.04). As regards complications, we found them in 27% of patients in group A, while only in 8% in Group B, with a statistically significant difference (p= 0.03). CONCLUSIONS: ESS and NLR are promising prognostic markers in PFF in the elderly patients. If used together, they could help in the pre- and post-operative management of the patients. [ABSTRACT FROM AUTHOR]

Introduction: Proximal femoral fractures (PFF) are a significant health concern among the elderly, often leading to complications and high mortality rates. Intramedullary nailing is widely considered the most effective treatment for lateral proximal femoral fractures (LPFF), with the Tip Apex Distance (TAD) being a crucial predictor of surgical success. This study aimed to compare outcomes between patients treated with and without the ADAPT (ADAptive Positioning Technology) system, which aids in the precise placement of the cephalic screw., Materials and Methods: A retrospective analysis was conducted on 97 patients with intertrochanteric fractures treated in 2022. Patients were divided into two groups: those treated with the ADAPT system (group I, n=34) and those treated without it (group II, n=63). Fractures were classified according to AO/OTA classification. The primary outcomes measured were operative time, cephalic screw angle, TAD, and incidence of lag screw cut-out. Statistical analyses included chi-square tests and t-tests, with significance set at P < 0.05., Results: The ADAPT system did not significantly reduce TAD (18.21 mm in the ADAPT group vs. 19.94 mm in the control group, p=0.149). Operative times were similar between the groups. The incidence of lag screw cut-out was low in both groups, with no significant differences. The study confirmed a strong correlation between higher TAD and increased risk of screw cut-out, underscoring the importance of precise screw placement., Discussion: Computer-assisted surgery, such as the ADAPT system, aims to enhance the accuracy of cephalic screw placement. In this study, the ADAPT system didn't demonstrate a statistically significant advantage in reducing TAD or preventing screw cut-out. Nevertheless, the critical role of TAD in preventing fixation failure was reaffirmed, emphasising the need for precise surgical techniques., Conclusion: While the ADAPT system did not show a significant advantage in reducing TAD or preventing screw cut-out in this study, the importance of achieving optimal TAD in cephalomedullary nailing was reinforced. Future research should continue to explore the role of computer-assisted systems in enhancing surgical accuracy and improving outcomes for patients with LPFF., Competing Interests: Each author declares that he or she has no commercial associations (e.g. consultancies, stock ownership, equity interest, patent/licensing arrangement etc.) that might pose a conflict of interest in connection with the submitted article.

Background: Megaprostheses were first employed in oncological orthopedic surgery, but more recently, additional applications have arisen. These implants are not without any risks and device failure is quite frequent. The most feared complication is undoubtedly the implants' infection; however, the exact incidence is still unknown. This systematic review aims to estimate in the current literature the overall incidence of megaprosthesis infections and to investigate possible risk/protective factors., Methods: We conducted a systematic search for studies published from July 1971 to December 2023 using specific keywords. To be included, studies needed to report either the megaprosthesis anatomical site, and/or whether the megaprosthesis was coated, and/or the surgical indication as oncological or non-oncological reasons., Results: The initial literature search resulted in 1281 studies. We evaluated 10,456 patients and the overall infection rate was 12%. In cancer patients, the infection rate was 22%, while in non-oncological patients, this was 16% (trauma 12%, mechanical failure 17%, prosthetic joint infections 26%). The overall infection rates comparing coated and uncoated implants were 10% and 12.5%, respectively., Conclusions: The number of megaprosthesis implants is increasing considerably. In traumatological patients, the infection rate is lower compared to all the other subgroups, while the infection rate remains higher in the cancer patient group. As these devices become more common, focused studies exploring epidemiological data, clinical outcomes, and long-term complications are needed to address the uncertainties in prevention and management.

Background: Nowadays, limb-sparing procedures are the gold standard in the treatment of soft-tissue sarcomas of the limbs. Wide tumor resection with appropriate oncological margins, reconstruction, and stabilization of the involved bone and joint and restoration of the soft tissue lost are essential in order to obtain good clinical and functional outcomes. Tumor excision and soft-tissue reconstruction performed in one-step surgery is chosen by many centers as the preferred approach; however, according to our experience in some selected patients, two-step surgery performed using a dermal regeneration template first and then a margin revision, taking into account the definitive results of the anatomopathological exam conducted over the surgical specimen from the previous surgery, associated with definitive reconstruction surgery over a healthy bed of granulated tissue, showed many potential benefits. Methods: A retrospective observational study was conducted on thirteen patients who underwent a two-step reconstruction procedure using dermal substitution after soft-tissue sarcoma excision. Results: Clinically, the enrolled patients achieved excellent contour and cosmesis of their surgical wounds, with a mean VSS value of 3.07. During the follow-up period, no local recurrences were observed in any patient. Conclusions: Two-step surgery represents the most suitable solution to allow surgical radicality with minimal recurrency and adequate soft-tissue reconstruction, avoiding the possibility of wasting autologous tissue. Our patients generally embraced this approach and the management that followed.

Fibroblast activation protein (FAP) is a very reliable biomarker for tissue remodeling. FAP has so far mainly been studied in oncology, but there is growing interest in the enzyme in other diseases like fibrosis. Recently, FAP-targeting diagnostics and therapeutics have emerged, of which the so-called FAPIs are among the most promising representatives. FAPIs typically have a relatively high molecular weight and contain very polar, multicharged chelator moieties. While this is not limiting the application of FAPIs in oncology, more druglike FAPIs could be required to optimally study diseases characterized by denser, less permeable tissue. In response, we designed the first druglike 18 F-labeled FAPIs. We report target potencies, biodistribution, and pharmacokinetics and demonstrate FAP-dependent uptake in murine tumor xenografts. Finally, this paper puts forward compound 10 as a highly promising, druglike FAPI for 18 F-PET imaging. This molecule is fit for additional studies in fibrosis and its preclinical profile warrants clinical investigation.

(1) Background: Osteoarthritis (OA) significantly impacts patients' quality of life and negatively affects public healthcare costs. The aim of this systematic review is to identify the effectiveness of pulsed electromagnetic fields (PEMFs) in OA treatment across different anatomical districts, determining pain reduction and overall improvement in the patient's quality of life. (2) Methods: In this systematic review following PRISMA guidelines, PubMed and Google Scholar were searched for randomized controlled trials involving patients with osteoarthritis undergoing PEMF therapy. Seventeen studies (1197 patients) were included. (3) Results: PEMF therapy demonstrated positive outcomes across various anatomical districts, primarily in knee osteoarthritis. Pain reduction, assessed through VAS and WOMAC scores, showed significant improvement (60% decrease in VAS, 42% improvement in WOMAC). The treatment duration varied (15 to 90 days), with diverse PEMF devices used. Secondary outcomes included improvements in quality of life, reduced medication usage, and enhanced physical function. (4) Conclusions: Diverse PEMF applications revealed promising results, emphasizing pain reduction and improvement in the quality of life of patients. The variability in the treatment duration and device types calls for further investigation. This review informs future research directions and potential advancements in optimizing PEMF therapies for diverse osteoarthritic manifestations.

Background: Managing distal humeral fractures can be challenging for orthopedic surgeons. There are several treatment options for managing this type of fracture, and the treatment method for these fractures should be based on patient-related factors. In elderly patients with osteoporotic bone and severe comminution of the fracture, adequate fixation can be a major challenge for surgeons. The use of megaprosthesis has been recently proposed in traumatology as an alternative to osteosynthesis or conventional prosthesis for the management of comminuted articular fractures in elderly patients with poor bone stock., Methods: A consecutive case series of 5 patients who underwent reconstruction of the elbow joint with a trabecular hinged modular elbow megaprosthesis was reviewed retrospectively. All patients included had AO/OTA 13C2 and 13C3 fractures with metaphyseal extension and considerable bone loss of the distal humerus. The primary outcome was the evaluation of functional and clinical outcomes with the MEPS score in comminuted distal humerus fractures with metaphyseal extension and poor bone stock in elderly patients treated with elbow megaprosthesis. The secondary outcome was assessing the treatment-related complication rate of this technique in non-oncological fields., Results: Five patients were included in the study with a mean age of 82.66 ± 7.72 years at surgery. The mean MEPS value was 63 ± 24.2 at 1 month, 81 ± 23.53 at 3 months, 83 ± 24.2 at 6 months, and 84 ± 24.57 at 12 months. No intraoperative complications were recorded in our series. Of 5 patients, four patients had excellent clinical and functional outcomes. We did not encounter wound dehiscence, prosthetic joint infection, aseptic loosening, or periprosthetic fractures., Conclusions: The indication for this type of treatment must be selected and narrowed down, as it is a salvage procedure, and any failure would cause even more complex situations. Short operating times and early mobilization of the elbow are the advantages of this technique., (© 2024. The Author(s).)

Background: Nondiabetic patients with open leg fractures who have elevated blood glucose levels on arrival in the emergency department have an increased risk of surgical-site infections (SSIs)., Objective: This study evaluates the association between the incidence of SSIs in nondiabetic patients with an open leg fracture and blood glucose levels registered on arrival in the ER. We also analyzed the correlation between patients' days of hospital stay and the incidence of SSIs and the time elapsed between the damage control with external fixation and final fixation and the incidence of SSI., Methods: We retrospectively studied nondiabetic patients admitted to our emergency unit from 2017 to 2021 with a diagnosis of open leg fracture consecutively treated. Based on the diagnosis of SSIs, all enrolled patients were divided into two groups based on the developed (group A) or not developed (group B) SSIs within 1 year after surgery. All patients enrolled in the study underwent damage control within 24 hours after admission to the ER. At stabilization of general clinical and local wound conditions, all patients underwent definitive surgery., Results: We enrolled 80 patients. In group A, glycemia on arrival in the ER was on average 148.35 ± 19.59 mg/dl, and in group B, it was 122.61 ± 22.22 mg/dl ( p value: 0.0001). In group A, glycemia in the first postoperative day was on average 113.81 ± 21.07 mg/dl, and in group B, it was 99.02 ± 17.60 mg/dl ( p value: 0.001). In group A, the average hospitalization was 57.92 ± 42.43 days, and in group B, it was 18.41 ± 14.21 days ( p value: 0.01). Through Youden's J, we therefore analyzed the value with the highest sensitivity and specificity which proved to be 132 mg/dl., Conclusion: Our findings show that nondiabetic patients with SIH have a significantly increased risk of SSIs compared to patients without SIH within 1 year after surgery. Patients with open leg fractures with SIH have a significantly higher average hospital stay than patients without SIH. Further studies are needed to confirm 132 mg/dl of blood glucose levels as a value to stratify the risk of SSIs in these patients., Competing Interests: The authors declare that they have no conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2023 Luigi Cianni et al.)

Introduction: To evaluate the clinical and functional outcomes of meniscal allograft transplantation (MAT) with anterior cruciate ligament reconstruction (ACLR) in a single surgical stage through a systematic review of the currently available evidence., Methods: A systematic search of the PubMed and Google Scholar databases, with no publication date limit, until December 2022 was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Follow-up studies and case series published in English involving patients undergoing a combination of ACLR and MAT were included. The quality of these studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) checklist. A systematic review of the International Knee Documentation Committee (IKDC), Lysholm and Tegner activity scores was conducted., Results: Seven studies involving 154 patients were included. The mean follow-up was 5,3 years. The mean age at the time of the surgery was of 35.3 years. All studies used the Lysholm Knee score, IKDC score or Tegner activity score to measure clinical outcomes post-operatively and the mean improvements were 26.7, 24.7, and 1.8 respectively. The rate to return to sport was 75.5 %. No intra-operative complications were reported. The post-operative complication rate was 11.6%., Conclusions: MAT combined with ACLR procedure showed good clinical results up to an average of 5 years of follow-up. More studies need to be conducted that can better understand the long-term effects of this combined procedure., Competing Interests: The authors declare no potential conflict of interest

Background: Femoral shaft fractures (FSFs) are a frequent injury in traumatology for which intramedullary nailing (IMN) is considered the gold standard treatment. Nonunion (NU) is one of the most frequent complications in FSF treated with IMN, with a percentage from 1.1% to 14%. Plate augmentation (PA), the addition of a compression plate and screws, with or without bone graft has been described as an effective option for the treatment of NU, improving the biomechanical conditions at the fracture site. The aim of this review was to analyze the literature relating to the use of PA in NU after IMN in FSFs to assess the efficacy of the technique., Methods: An electronic search on PubMed, Google Scholar, and Web of Science was conducted to search for all studies concerning PA of femoral shaft NUs after IMN., Results: Twenty-four studies were included in the review comprising a total of 502 patients with a mean age of 39.5 years. Of these, 200 hundred patients had atrophic pseudoarthrosis and 123 had hypertrophic pseudoarthrosis, while in 179, the type of pseudoarthrosis was not reported. The most frequently used plate for PA was the dynamic compression plate (DCP); in 87.1% of the cases, the authors added a bone graft to the plate fixation. In 98.0% of the patients, a complete bone union was achieved in a mean time of 5.8 ± 2.12 months., Conclusion: The patients treated with PA included in this review showed a good rate of consolidation in the femoral shaft NUs, with good functional recovery and a low incidence of complications.

Background: Consensus on the treatment for severely comminuted calcaneus fractures has yet to be found. This study aims to analyze the functional and radiological short- and medium-term outcomes of displaced calcaneus fractures of type III and IV treated with ORIF, and to identify, if present, the early predictors of unfavorable outcomes., Methods: Thirty-three calcaneal fractures were included, 23 type III and 10 type IV, according to Sanders classification. AOFAS scales for ankle and hindfoot and SF-12 were used. Böhler and Gissane angles were analyzed before and after surgery., Results: The minimum follow-up was six years. The mean AOFAS score at six months was 16.5 points (24.2 ± 10.8 vs 10.8 ± 9.5; p = 0.03) with better outcomes in patients with Sanders type III fractures. This difference decreased in the subsequent follow-up. Likewise, the mental and physical score of SF-12 had the same trend. Two wound infections and no deep infections were recorded in the Sanders type III fracture group. Instead, in the Sanders type IV group, there were four wound infections and one deep infection., Conclusions: Clinical and radiological outcomes in Sanders Type III and Type IV calcaneus fractures treated with plate and screws were very similar in long-term follow-up. If ORIF provided better short- to medium-term follow-up in Sanders type III fracture, these benefits have been lost in six years. Polytrauma and psychiatric patients showed significantly lower clinical outcomes in long-term follow-up, appearing as the most reliable negative predictors.

Background: Extracapsular proximal femur metastasis could be treated by synthesis or resection and megaprosthesis. No universal accepted guidelines are present in the literature. The aim of our study is to analyze of patients with metastases in the trochanteric region of the femur treated by a single type of intramedullary nailing or hip megaprosthesis., Methods: We retrospectively reviewed all patients affected by extracapsular metastases of proximal femur. Anthropometric and anamnestic data, routine blood exams and complications were collected. VAS score and MSTS score was administered before the surgery, ad 1-6-12 months after surgery. An un-paired T test and Chi-square were used. Multiple linear regression and logistic regression was performed. Significance was set for p < 0.05., Result: Twenty patients were assigned in intramedullary Group, twenty-five in megaprostheses Group. The mean operative time is shorter in intramedullary group. Differential shows a higher anemization in megaprostheses group (2 ± 2 vs 3.6 ± 1.3; p = 0.02). The patients of intramedullary group showed malnutrition (Albumin: 30.5 ± 6.5 vs 37.6 ± 6 g/L; p = 0.03) and pro-inflammatory state (NLR: 7.1 ± 6.7 vs 3.8 ± 2.4; p = 0.05) (PLR: 312 ± 203 vs 194 ± 99; p = 0.04) greater than megaprostheses group. The patients in intramedullary groups shows a higher functional performance score than megaprostheses group at 1 month follow-up (MSTS: 16.4 ± 6.3 vs 12.2 ± 3.7; p = 0.004). A multivariate analysis confirms the role of type of surgery (p = 0.001), surgery duration (p = 0.005) and NLR (p = 0.02) in affecting the MSTS. Globally eight complications were recorded, no statistical difference was noticed between the two groups (p = 0.7), no predictor was found at logistic analysis., Conclusion: Intramedullary nailing guarantees a rapid functional recovery, compared to patients undergoing hip megaprosthesis who instead improve gradually over time. The selection of patients with poor prognosis allows the correct surgical indication of nailing, while in the case of a more favorable prognosis, the intervention of hip megaprosthesis is to be preferred., (© 2022. The Author(s).)

Bone can be affected by different neoplastic conditions. Limb salvage surgery has become the preferred treatment strategy for most malignant tumors of the extremities. Advanced 3D printing technology has transformed the conventional view of oncological surgery. These types of implants are produced by electron beam melting (EBM) technology by sintering titanium powder in a scaffold shape designed following a project designed from HRCT and MRI. The aim of our study was to evaluate the outcomes and the mid-term follow-up of a population treated with 3D-printed custom-made prosthesis implantation in major oncological bone resection or after failure of primary implants. The primary outcome was the general patient satisfaction one year after surgery. The secondary outcomes were: mortality rate, treatment related complication rate, functional and clinical outcomes (KPS, ADL and IADL). Eight patients were included, five females and two males, with a mean age of 50.3 (±23.72) years at the surgery. The enrolled patients reported a mean satisfaction rate after surgery of 7.38 (±2) where 10 was the maximum value. There were no changes between pre- and postoperative mean KPS (81.43 +/−10.69). Mean preoperative ADL and IADL score was in both cases 4.86 (±1.07), while postoperative was 5 (±0.82), with a delta of 0.13 (p > 0.05). Custom-made prosthesis permits reconstructing bone defects caused by large tumor resection, especially in anatomically complex areas, restoring articular function.

Background: Tibia is a rare location among all skeletal metastases. Those lesions are often discovered in an advanced stage of disease and are mainly reported to the orthopedic surgeon to reduce pain, to improve the patient quality of life and his functional status. Current literature on the surgical management of metastases and/or pathological tibial fractures shows mostly few case reports, case series or at most retrospective studies on very small and heterogeneous groups of patients. The purpose of this study is to analyze those articles highlighting epidemiology and discussing surgical options and relative outcomes., Methods: Studies were searched on PubMed, Google Scholar and Web of Knowledge from inception to September 2020 and 30 articles discussing tibial metastasis surgical treatment were included., Results: Results discuss age and sex of patients, location of tibial metastases, origin of metastases, type of lesion and spread of disease, surgical treatment, outcomes in terms of pain evolution, gain of function and general status, complication and relapse, and survival of patients., Conclusions: Despite the lack of randomized trials and the absence of high-level studies, guidelines suggest different types of treatments depending on location and stage of disease. The analysis of the articles included in this review confirms the heterogeneity of possible treatments, assuring, independently of the chosen techniques, good and similar results, leading to the conclusion that the choice of the surgical technique must take in consideration each patient's characteristics and the surgeon's experience.

Implant-associated infections remain one of the main problems in the treatment of open tibia fractures. The role of systemic antibiotic prophylaxis is now agreed and accepted; nevertheless, recent literature also seems to emphasize the importance of local antibiotic therapy at the fracture site. Several therapeutic strategies have been proposed to overcome this new need. Antibiotic-coated nails play crucial role in this, allowing both infection prevention and favoring the fracture stabilization. We describe the outcome of patients with open diaphyseal tibia fracture treated either with a standard uncoated nail or a gentamicin-coated nail from January 2016 to December 2018 at our second level emergency-urgency department. Primary outcomes were infection rate and bone union rate. Other outcomes reported are reoperation rate, time between injury and nailing, and safety of antibiotic nail. Numerical variables were tabulated using mean, standard deviation, minimum, maximum, and number of observations. Categorical variables were tabulated using number of observations. 23 patients treated with uncoated nail and 23 patients treated with antibiotic-coated tibia nail were included in the study and were evaluated for a minimum follow-up of 18 months. Among the 46 patients, 9 were Gustilo-Anderson type I, 21 type II, and 16 type III open fracture. Regarding the bone healing rate at 12 months, 16 fractures in the first group and 18 in the second were completely healed. 4 infections were found in the first group (3 superficial surgical site infection and 1 osteomyelitis) and 3 superficial infections in the second one. No adverse events have been recorded with antibiotic-coated nails. In this unicentric retrospective study observed no deep wound infections and good fracture healing in the use of antibiotic-coated nails. Antibiotic nails have been shown to play a role in the treatment of fractures in critically ill patients with severe soft tissue damage., Competing Interests: The authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in the manuscript., (Copyright © 2021 Tommaso Greco et al.)

Human cathepsin B (CatB) is an important biological target in cancer therapy. In this work, we performed a knowledge-based design approach and the synthesis of a new set of 19 peptide-like nitrile-based cathepsin inhibitors. Reported compounds were assayed against a panel of human cysteine proteases: CatB, CatL, CatK, and CatS. Three compounds (7h, 7i, and 7j) displayed nanomolar inhibition of CatB and selectivity over CatK and CatL. The selectivity was achieved by using the combination of a para biphenyl ring at P3, halogenated phenylalanine in P2 and Thr-O-Bz group at P1. Likewise, compounds 7i and 7j showed selective CatB inhibition among the panel of enzymes studied. We have also described a successful example of bioisosteric replacement of the amide bond for a sulfonamide one [7e → 6b], where we observed an increase in affinity and selectivity for CatB while lowering the compound lipophilicity (ilogP). Our knowledge-based design approach and the respective structure-activity relationships provide insights into the specific ligand-target interactions for therapeutically relevant cathepsins., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background and Aim of the Work: To report the history and clinical presentation of a 60-year-old male who developed a rare soft tissue infection of the right leg caused by Bacillus megaterium and to perform a Literature review focusing on clinical manifestations and diagnostic difficulties of the aforementioned bacterium., Methods: Medical history and clinical presentation suggested the infectious etiology, which led to the surgical procedure of fistulectomy and to further histological and microbiological investigations with bacterial cultures., Results: The histological report tested negative for osteomyelitis. Bacterial cultures revealed Bacillus megaterium, which was sensitive to all antibiotics against which it was tested. The oral antibiotic therapy was set for 12 days with benefits. The patient has always been apyretic, inflammation indexes and white cells count have been within normal limits.  Conclusions: This was a rare case of soft tissue infection caused by Bacillus megaterium known to be a "non-pathogenic" bacterium. The infection was likely acquired by the penetration through the injury wound. The combination of surgical and antibiotic therapy lead to complete skin healing and infection resolution at the 6-months follow up.

Leishmania mexicana is an obligate intracellular protozoan parasite that causes the cutaneous form of leishmaniasis affecting South America and Mexico. The cysteine protease LmCPB is essential for the virulence of the parasite and therefore, it is an appealing target for antiparasitic therapy. A library of nitrile-based cysteine protease inhibitors was screened against LmCPB to develop a treatment of cutaneous leishmaniasis. Several compounds are sufficiently high-affinity LmCPB inhibitors to serve both as starting points for drug discovery projects and as probes for target validation. A 1.4 Å X ray crystal structure, the first to be reported for LmCPB, was determined for the complex of this enzyme covalently bound to an azadipeptide nitrile ligand. Mapping the structure-activity relationships for LmCPB inhibition revealed superadditive effects for two pairs of structural transformations. Therefore, this work advances our understanding of azadipeptidyl and dipeptidyl nitrile structure-activity relationships for LmCPB structure-based inhibitor design. We also tested the same series of inhibitors on related cysteine proteases cathepsin L and Trypanosoma cruzi cruzain. The modulation of these mammalian and protozoan proteases represents a new framework for targeting papain-like cysteine proteases., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A library of cathepsin S inhibitors of the dipeptide nitrile chemotype, bearing a bioisosteric sulfonamide moiety, was synthesized. Kinetic investigations were performed at four human cysteine proteases, i.e. cathepsins S, B, K and L. Compound 12 with a terminal 3-biphenyl sulfonamide substituent was the most potent (K i  = 4.02 nM; selectivity ratio cathepsin S/K = 5.8; S/L = 67) and 24 with a 4'-fluoro-4-biphenyl sulfonamide substituent the most selective cathepsin S inhibitor (K i  = 35.5 nM; selectivity ratio cathepsin S/K = 57; S/L = 31). In silico design and biochemical evaluation emphasized the impact of the sulfonamide linkage on selectivity and a possible switch of P2 and P3 substituents with respect to the occupation of the corresponding binding sites of cathepsin S., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The cysteine protease cruzipain is considered to be a validated target for therapeutic intervention in the treatment of Chagas disease. Hence, peptidomimetic cruzipain inhibitors having a reactive group (known as warhead) are subject to continuous studies to discover novel antichagasic compounds. Here, we evaluated how different warheads for a set of structurally similar related compounds could inhibit the activity of cruzipain and, ultimately, their trypanocidal effect. We first investigated in silico the intrinsic reactivity of these compounds by applying the Fukui index to correlate it with the enzymatic affinity. Then, we evaluated their potency against T. cruzi (Y and Tulahuen strains), which revealed the reversible cruzain inhibitor Neq0656 as a better trypanocidal agent (EC Y.strain 50 = 0.1 μM; SI = 58.4) than the current drug benznidazole (EC Y.strain 50 = 5.1 μM; SI > 19.6). We also measured the half-life time by HPLC analysis of three lead compounds in the presence of glutathione and cysteine to experimentally assess their intrinsic reactivity. Results clearly illustrated the reactivity trend for the warheads (azanitrile > aldehyde > nitrile), where the aldehyde displayed an intermediate intrinsic reactivity. Therefore, the aldehyde bearing peptidomimetic compounds should be subject for in-depth evaluation in the drug discovery process., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Cruzain is an established target for the identification of novel trypanocidal agents, but how good are in vitro/in vivo correlations? This work describes the development of a random forests model for the prediction of the bioavailability of cruzain inhibitors that are Trypanosoma cruzi killers. Some common properties that characterize drug-likeness are poorly represented in many established cruzain inhibitors. This correlates with the evidence that many high-affinity cruzain inhibitors are not trypanocidal agents against T. cruzi. On the other hand, T. cruzi killers that present typical drug-like characteristics are likely to show better trypanocidal action than those without such features. The random forests model was not outperformed by other machine learning methods (such as artificial neural networks and support vector machines), and it was validated with the synthesis of two new trypanocidal agents. Specifically, we report a new lead compound, Neq0565, which was tested on T. cruzi Tulahuen (β-galactosidase) with a pEC 50 of 4.9. It is inactive in the host cell line showing a selectivity index (SI = EC 50 cyto /EC 50 T. cruzi ) higher than 50., (© 2020 John Wiley & Sons A/S.)

Cysteine proteases (CPs) are involved in a myriad of actions that include not only protein degradation, but also play an essential biological role in infectious and systemic diseases such as cancer. CPs also act as biomarkers and can be reached by active-based probes for diagnostic and mechanistic purposes that are critical in health and disease. In this paper, we present the modulation of a CP panel of parasites and mammals (Trypanosoma cruzi cruzain, LmCPB, CatK, CatL and CatS), whose inhibition by nitrile peptidomimetics allowed the identification of specificity and selectivity for a given CP. The activity cliffs identified at the CP inhibition level are useful for retrieving trends through multiple structure-activity relationships. For two of the cruzain inhibitors (10g and 4e), both enthalpy and entropy are favourable to Gibbs binding energy, thus overcoming enthalpy-entropy compensation (EEC). Group contribution of individual molecular modification through changes in enthalpy and entropy results in a separate partition on the relative differences of Gibbs binding energy (ΔΔG). Overall, this study highlights the role of CPs in polypharmacology and multi-target screening, which represents an imperative trend in the actual drug discovery effort., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Sarcomas are a heterogeneous group of rare tumours. Improvements in immunotherapy and the important role of PD1 and PD-L1 expression in advancement and prognosis have opened new fields of research for the treatment of these neoplasia. We evaluated the immunohistochemistry of PD1 and PD-L1 expression in 60 adults' patients affected by high-grade sarcomas of the limbs. PD1 expression was 65% while PD-L1 was 68.3%. PD-L1 expression seems to correlate to Ki67 in liposarcomas, fibrosarcoma's and pleomorphic sarcomas, while it does not show any correlation to chondrosarcomas, while in rhabdomyosarcomas there is a correlation but, given the small sample size, it was not possible to perform a statistic analysis. Our study shows positivity among the different subgroups of positive PD1 lymphocytes infiltration and PD-L1 expression in high-grade sarcomas of the limbs., (Copyright 2020 Biolife Sas. www.biolifesas.org.)

Osteoma is a benign, slowly growing, asymptomatic, bone-forming tumor arising from cancellous or compact bone. Osteoma usually is a solitary lesion, but in patients with Gardner's Syndrome it may be multiple. osteoma may rarely have a parosteal localization. Parosteal osteoma has peculiar radiographic, histologic and clinical features. We describe a case report of a 51- years old man with a bifocal parosteal osteoma of the femur in a non-syndromic patient. This is the first described patient with a bifocal lesion. In literature only 24 cases of paraosteal osteoma are found. Our patient underwent surgery and the lesions were fully excised. At one year follow-up there was no evidence of recurrence., Competing Interests: Conflict of interest: the authors declare no potential conflict of interest., (©Copyright: the Author(s).)

The Charcot foot is a condition characterized by a progressive derangement of the foot. The type of deformity and patient clinical conditions will lead to the proper surgical approach among exostectomy, arthrodesis (through external and/or internal fixation) and amputation. Many authors report good clinical outcomes performing the arthrodesis in Charcot foot; however, the choice of the most appropriate hardware is still an issue. The aim of this study is to analyze the outcomes of different hardware in midfoot and hindfoot Charcot arthrodesis., (©Copyright: the Author(s).)

Foot metastasis are rare and often overlooked due to non-specifical symptoms. This often leads to misdiagnosis delaying the right diagnosis. Metastatic disease of the foot is rare. Foot pain and swelling may be the presenting symptom of an occult malignancy. If metastatic disease is not kept in the differential diagnosis of foot pain, diagnosis and treatment will be delayed. The purpose of this study was to analyze articles presenting cases of foot metastasis to provide a more accurate incidence of symptomatic foot acrometastasis as well as to review the clinical course and outcomes. Studies were searched on PubMed/Medline from the inception to February 2020. All studies included in the review presented foot metastasis either with or without a known primary tumor. Most of the articles were case reports, to which we added two case reports of foot acrometastasis produced by our Institute. Forty-three studies with a total of 45 patients were included in this review. The literature published mostly concerning case reports about old patients (average age: 63,2), in a late phase of their disease. Lung cancer appeared to be the most common primary tumor, followed by endometrial and breast cancer. In the 36% of the cases foot metastasis were found when the primary site was still unknown. Calcaneus and metatarsal bones were the most common bones involved. Surgical solution is rare, the chosen treatments are often of palliative care. Prognosis was often poor, death occurred within 2 years since the discovery of foot metastasis in about 50% of cases., Competing Interests: Conflict of interest: the authors declare no potential conflict of interest., (©Copyright: the Author(s).)

Implant-associated infections remain one of the main problems in trauma surgery, particularly for treatment of open tibial fractures. The role of systemic antibiotic prophylaxis is now established and accepted, but recent literature also seems to emphasize the importance of local antibiotic prophylaxis. Antibiotic coated nails play a crucial role, allowing at the same time the prevention of infections and favoring the stabilization of fractures. These devices appear to be a clinically effective and safe solution. The purpose of the study was to investigate the role of antibiotic coated nails in the treatment of tibia fractures. A literature review was performed on MEDLINE through PubMed to identify scientific publications relevant to the use of antibiotic coated nails in tibial fractures. Primary outcomes were infection rate and bone union rate. This review present numerous limits due primarily to the small number and different nature of studies published; the heterogeneity of the devices used., (Copyright 2020 Biolife Sas. www.biolifesas.org.)

Reversible and irreversible covalent ligands are advanced cysteine protease inhibitors in the drug development pipeline. K777 is an irreversible inhibitor of cruzain, a necessary enzyme for the survival of the Trypanosoma cruzi ( T. cruzi ) parasite, the causative agent of Chagas disease. Despite their importance, irreversible covalent inhibitors are still often avoided due to the risk of adverse effects. Herein, we replaced the K777 vinyl sulfone group with a nitrile moiety to obtain a reversible covalent inhibitor ( Neq0682 ) of cysteine protease. Then, we used advanced experimental and computational techniques to explore details of the inhibition mechanism of cruzain by reversible and irreversible inhibitors. The isothermal titration calorimetry (ITC) analysis shows that inhibition of cruzain by an irreversible inhibitor is thermodynamically more favorable than by a reversible one. The hybrid Quantum Mechanics/Molecular Mechanics (QM/MM) and Molecular Dynamics (MD) simulations were used to explore the mechanism of the reaction inhibition of cruzain by K777 and Neq0682 . The calculated free energy profiles show that the Cys25 nucleophilic attack and His162 proton transfer occur in a single step for a reversible inhibitor and two steps for an irreversible covalent inhibitor. The hybrid QM/MM calculated free energies for the inhibition reaction correspond to -26.7 and -5.9 kcal mol -1 for K777 and Neq0682 at the MP2/MM level, respectively. These results indicate that the Δ G of the reaction is very negative for the process involving K777 , consequently, the covalent adduct cannot revert to a noncovalent protein-ligand complex, and its binding tends to be irreversible. Overall, the present study provides insights into a covalent inhibition mechanism of cysteine proteases.

The cysteine protease cruzipain is considered to be a validated target for therapeutic intervention in the treatment of Chagas disease. A series of 26 new compounds were designed, synthesized, and tested against the recombinant cruzain (Cz) to map its S1/S1´ subsites. The same series was evaluated on a panel of four human cysteine proteases (CatB, CatK, CatL, CatS) and Leishmania mexicana CPB, which is a potential target for the treatment of cutaneous leishmaniasis. The synthesized compounds are dipeptidyl nitriles designed based on the most promising combinations of different moieties in P1 (ten), P2 (six), and P3 (four different building blocks). Eight compounds exhibited a Ki smaller than 20.0 nM for Cz, whereas three compounds met these criteria for LmCPB. Three inhibitors had an EC50 value of ca. 4.0 μM, thus being equipotent to benznidazole according to the antitrypanosomal effects. Our mapping approach and the respective structure-activity relationships provide insights into the specific ligand-target interactions for therapeutically relevant cysteine proteases., Competing Interests: The authors have declared that no competing interests exist.

Cysteine proteases are important targets for the discovery of novel therapeutics for many human diseases. From parasitic diseases to cancer, cysteine proteases follow a common mechanism, the formation of an encounter complex with subsequent nucleophilic reactivity of the catalytic cysteine thiol group toward the carbonyl carbon of a peptide bond or an electrophilic group of an inhibitor. Modulation of target enzymes occurs preferably by covalent modification, which imposes challenges in balancing cross-reactivity and selectivity. Given the resurgence of irreversible covalent inhibitors, can they impair off-target effects or are reversible covalent inhibitors a better route to selectivity? This Perspective addresses how small molecule inhibitors may achieve selectivity for different cathepsins, cruzain, rhodesain, and falcipain-2. We discuss target- and ligand-based designs emphasizing repurposing inhibitors from one cysteine protease to others.

Nitrile reversible covalent inhibitors of human cathepsin L (hCatL) bind covalently to the side chain of the catalytic Cys25 residue in the S1 pocket to form thioimidates. Predicting the binding of reversible covalent inhibitors is essential for their practical application in drug design. In this report, five nitrile-based inhibitors coded Neq0570, Neq0710, Neq0802, Neq0803 and Neq0804 had their hCatL inhibition constants, K i , determined. These analogs of the prototypical Neq0570 are halogenated reversible covalent inhibitors of hCatL, which bear a halogen atom in the meta position of the P3 benzyl ring that can form a halogen bond with the Gly61 of the hCatL. To describe halogen bonding interaction in an inhibitor-hCatL complex, we applied an extra point (EP) of charge to represent the anisotropic distribution of charge on the iodine, bromine and chlorine atoms. Besides, we have used alchemical free energy calculations for evaluating the overall relative binding free energies of these inhibitors using a two-state binding model: noncovalent and covalent bond states. Our results show that free energy perturbation (FEP) can predict the hCatL binding affinities of halogenated reversible covalent inhibitors in close agreement with experiments.

The structure-activity relationship for nitrile-based cruzain inhibitors incorporating a P2 amide replacement based on trifluoroethylamine was explored by deconstruction of a published series of inhibitors. It was demonstrated that the P3 biphenyl substituent present in the published inhibitor structures could be truncated to phenyl with only a small loss of affinity. The effects of inverting the configuration of the P2 amide replacement and linking a benzyl substituent at P1 were observed to be strongly nonadditive. We show that plotting affinity against molecular size provides a means to visualize both the molecular size efficiency of structural transformations and the nonadditivity in the structure-activity relationship. We also show how the relationship between affinity and lipophilicity, measured by high-performance liquid chromatography with an immobilized artificial membrane stationary phase, may be used to normalize affinity with respect to lipophilicity., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Chagas disease affects millions of people in Latin America. This disease is caused by the protozoan parasite Trypanossoma cruzi. The cysteine protease cruzain is a key enzyme for the survival and propagation of this parasite lifecycle. Nitrile-based inhibitors are efficient inhibitors of cruzain that bind by forming a covalent bond with this enzyme. Here, three nitrile-based inhibitors dubbed Neq0409, Neq0410 and Neq0570 were synthesized, and the thermodynamic profile of the bimolecular interaction with cruzain was determined using isothermal titration calorimetry (ITC). The result suggests the inhibition process is enthalpy driven, with a detrimental contribution of entropy. In addition, we have used hybrid Quantum Mechanical/Molecular Mechanical (QM/MM) and Molecular Dynamics (MD) simulations to investigate the reaction mechanism of reversible covalent modification of cruzain by Neq0409, Neq0410 and Neq0570. The computed free energy profile shows that the nucleophilic attack of Cys25 on the carbon C1 of inhibitiors and the proton transfer from His162 to N1 of the dipeptidyl nitrile inhibitor take place in a single step. The calculated free energy of the inhibiton reaction is in agreement with covalent experimental binding. Altogether, the results reported here suggests that nitrile-based inhibitors are good candidates for the development of reversible covalent inhibitors of cruzain and other cysteine proteases.

Cruzain is the major cysteine protease of Trypanosoma cruzi, the etiological agent of Chagas disease. Reversible covalent cruzain inhibitors can block the steps of cell differentiation in the parasite and kill the organism. To this end, the description of how inhibitors modified at the P2/P3 positions lead to analogs with greater cruzain affinity to the S2/S3 subsites is of fundamental importance. Albeit many efforts are being employed in the characterization of the interaction processes with S2 subsite, little is known about the cruzain S3 subsite. In this work, we show a brief but consistent study to identify favorable substitutions in P3 of dipeptidyl nitriles that increase cruzain affinity. Using molecular dynamics simulations, we have identified some dipeptidyl nitrile analogs with modifications at P3 position that had higher cruzain inhibition than the original unsubstituted compound. A matched molecular pair analysis shows the importance of including a chlorine atom in the P3-meta position. The modifications implemented in P3 are confirmed when profiling the thermodynamic parameters via isothermal titration calorimetry. The classical enthalpy-entropy compensation phenomenon, in which enthalpy changes are counterbalanced by entropy results in a small modification of ΔG. The inclusion of the chlorine atom in the P3-meta position results in the highest reduction of the detrimental entropic contribution observed in P3., (Copyright © 2018 Elsevier Inc. All rights reserved.)

In this paper, the selective interactions of synthetic derivatives of two natural compounds, berberine and palmatine, with DNA G-quadruplex structures were reported. In particular, the previous works on this subject concerning berberine were further presented and discussed, whereas the results concerning palmatine are presented here for the first time. In detail, these palmatine derivatives were developed by inserting seven different small peptide basic chains, giving several new compounds that have never been reported before. The preliminary studies of the interactions of these compounds with various G-quadruplex-forming sequences were carried out by means of various structural and biochemical techniques, which showed that the presence of suitable side chains is very useful for improving the interaction of the ligands with G-quadruplex structures. Thus, these new palmatine derivatives might act as potential anticancer drugs.

The effects on potency of cruzain inhibition of replacing a nitrile group with alternative warheads were explored. The oxime was almost an order of magnitude more potent than the corresponding nitrile and has the potential to provide access to the prime side of the catalytic site. Dipeptide aldehydes and azadipeptide nitriles were found to be two orders of magnitude more potent cruzain inhibitors than the corresponding dipeptide nitriles although potency differences were modulated by substitution at P1 and P3. Replacement of the α methylene of a dipeptide aldehyde with cyclopropane led to a loss of potency of almost three orders of magnitude. The vinyl esters and amides that were characterized as reversible inhibitors were less potent than the corresponding nitrile by between one and two orders of magnitude., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

A novel approach to cancer therapeutics is emerging in the field of G-quadruplex (G4) ligands, small molecules designed to stabilize four-stranded structures that can form at telomeres as well as in other genomic sequences, including oncogene promoter sequences, 5'-UTR regions and introns. In this study, we investigated the binding activity of perylene and coronene derivatives PPL3C, CORON and EMICORON to G4 structures formed within the promoter regions of two important cancer-related genes, c-MYC and BCL-2, and their biochemical effects on gene and protein expression. In order to fully characterize the ability of the selected ligands to bind and stabilize the G4 structures originated by the c-MYC and BCL-2 promoter sequences, we performed electrospray ionization mass spectrometry (ESI-MS), Fluorescence Resonance Energy Transfer (FRET) measurements, Circular Dichroism (CD) spectra and polymerase stop assay. Altogether our results showed that the ligands had a high capacity in binding and stabilizing the G4 structures within the c-MYC and BCL-2 promoter sequences in vitro. Notably, when we evaluated by quantitative real-time PCR and western blotting analysis, the effects of treatment with the different G4 ligands on c-MYC and BCL2 expression in a human melanoma cell line, EMICORON appeared the most effective compound in reducing the mRNA and protein levels of both genes. These results encourage to consider EMICORON as a promising example of multimodal class of an antineoplastic drug, affecting different tumor crucial pathways simultaneously: telomere maintenance (as previously described), cell proliferation and apoptosis via down-regulation of both c-MYC and BCL-2 (this paper)., (Copyright © 2016 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.)