A biomechanical study of the role of sitagliptin on the bone characteristics of diabetic rats

An experimental protocol is described aiming to explore the in­fluence of Type 2 Diabetes Mellitus on the biomechanical response of the bone tissue and, also, to quantify the potential beneficial role of a pharma­ceutical treatment, based on sitagliptin, a diabetes drug that increases the levels of natural substances called incretins. Twenty eight male, 10-week old Wistar rats were used, divided into three groups, i.e., the control one, the group including the diabetic rats and, finally, the group including the diabetic rats which were treated using sitagliptin. The biomechanical study was based on a series of three-point bending tests of the femora of the sacrificed rats and the analysis of the experimental data was implemented in terms of the actual geometry of the fractured cross-section. It was concluded that diabetic bones undertake larger forces despite the fact that the “diameter” of their cross-section was some­­how smaller. On the contrary, the slope of the load-deflection curve (cor­responding to a measure of the stiffness) of diabetic bones is slightly lower compared to the control bones. Finally, it seems that treating diabetic animals with sita­gliptin only partly reverses the effect of Type 2 Diabetes Mellitus on their bone tissue, at least concerning its strength and stiffness

Effect of community-based education on undergraduate nursing students’ skills: a systematic review

Abstract: Background: Community-based education, as an effective approach to strengthen nurses’ skills in response to society’s problems and needs has increased in nursing education programs. The aim of this study was to review the effect of community-based education on nursing students’ skills. Methods: For this systematic review, ProQuest, EMBASE, Scopus, PubMed/ MEDLINE, Cochran Library, Web of Science, CINAHL and Google Scholar were searched up to February 2021. The methodological quality of the studies was assessed using the Mixed Methods Appraisal Tool (MMAT). Seventeen studies were included in this systematic review. Inclusion criteria included articles published in English and were original articles. Results: In all studies, undergraduate nursing students’ skills were improved by participation in a community-based education program. Community-based education enhances professional skills, communication skills, self-confidence, knowledge and awareness, and critical thinking skills and teamwork skills in undergraduate nursing students. Conclusions: Community-based education should be used as an effective and practical method of training capable nurses to meet the changing needs of society, to improve nurses ‘skills and empower them to address problems in society

Fine Mapping of Genetic Variants in BIN1, CLU, CR1 and PICALM for Association with Cerebrospinal Fluid Biomarkers for Alzheimer's Disease

Recent genome-wide association studies of Alzheimer's disease (AD) have identified variants in BIN1, CLU, CR1 and PICALM that show replicable association with risk for disease. We have thoroughly sampled common variation in these genes, genotyping 355 variants in over 600 individuals for whom measurements of two AD biomarkers, cerebrospinal fluid (CSF) 42 amino acid amyloid beta fragments (Aβ42) and tau phosphorylated at threonine 181 (ptau181), have been obtained. Association analyses were performed to determine whether variants in BIN1, CLU, CR1 or PICALM are associated with changes in the CSF levels of these biomarkers. Despite adequate power to detect effects as small as a 1.05 fold difference, we have failed to detect evidence for association between SNPs in these genes and CSF Aβ42 or ptau181 levels in our sample. Our results suggest that these variants do not affect risk via a mechanism that results in a strong additive effect on CSF levels of Aβ42 or ptau181

Comparative study of the effect of antidiabetic drugs in the pathogenesis of osteoporosis

Introduction: The effects of incretin-based drugs, like glucagon-like peptide-1 (GLP-1) receptor agonists and inhibitors of dipeptidyl peptidase-4 (DPP-4) on bone metabolism are not completely clear yet. The aim of this study is to elucidate how the different parameters of the incretin pathway affect bone quality in terms of biomechanical properties, bone turnover and mineral properties.Materials and methods: Forty 10-week-old Wistar rats were divided in four groups: a control group, a control diabetic group, a diabetic group treated with sitagliptin, and a diabetic group treated with exenatide. Type 2 Diabetes was simulated by dietary manipulation and low dose streptozotocin and then the two different incretin-based drugs were administered. The rats were sacrificed after five weeks of therapeutic treatment. Their serum was analyzed with ELISA method for basic bone turnover markers and their right femur was subjected to three-point bending test. Finally, hematoxylin/ eosin staining in addition to RAMAN spectroscopy were employed to access the collagen and mineral properties of the bone.Results: Both incretin- based drugs reduced osteoclast function, however, they were not able to restore osteoblastic function to normal. The net effect on bone strength was surprising: bone elasticity was restored by the antidiabetic treatment, but bone strength deteriorated. Exenatide had a more pronounced effect, confirming the suspicion that DPP4 may be a linking factor between reduced osteoclastic function and reduced bone formation.Conclusion: DPP4 receptors seems to be one of the links between reduced osteoclast function and reduced bone remodeling, so DPP4 inhibition can be more detrimental to the bone than GLP-1 receptor agonists.Σκοπός: Σκοπός της μελέτης είναι να αποσαφηνίσει τη συσχέτιση του μονοπατιού των ινκρετινών με την παθογένεση της οστεοπόρωσης. Στην παρούσα μελέτη συγκρίνουμε δυο διαφορετικά αντιδιαβητικά φάρμακα βασισμένα στο μονοπάτι των ινκρετινών.Υλικά και μέθοδοι: Χρησιμοποιήθηκαν 40 επίμυες Wistar, οι οποίοι χωρίστηκαν μετά από τυχαιοποίηση σε 4 ομάδες. Η ομάδα 1 ήταν ομάδα control, η ομάδα 2 ήταν διαβητικά ζώα που δεν έλαβαν αγωγή, η ομάδα 3 ήταν διαβητικά ζώα στα οποία χορηγήθηκε αναστολέας του dpp4 (10 mg/kg/day) ενώ στην ομάδα 4 χορηγήθηκε αγωνιστής του glp-1 (10 μg/kg/day). Το μοντέλο του διαβήτη τύπου 2 που χρησιμοποιήθηκε για τα 30 διαβητικά ζώα βασίστηκε στη χορήγηση φρουκτόζης σε συνδυασμό με χαμηλή δόση στρεπτοζοτοκίνης. Μετά από 5 εβδομάδες θεραπείας έγινε αιμοληψία και κατόπιν θυσία των πειραματοζώων. Τα μηριαία των πειραματοζώων χρησιμοποιήθηκαν για μελέτες μηχανικής αντοχής και φασματοσκοπίας Ραμαν, ενώ το αίμα τους μελετήθηκε με μέθοδο ELISA για δείκτες οστικού σχηματισμού και απορρόφησης. Τα αριστερά μηριαία χρησιμοποιήθηκαν για παθολογανατομική μελέτη.Αποτελέσματα: Και τα δυο φάρμακα μείωσαν την οστεοκλαστική λειτουργία, ωστόσο δεν μπόρεσαν να επαναφέρουν τον οστικό επανασχηματισμό. Η συνολική επίδραση στην αντοχή του οστού ήταν απρόσμενη, καθώς η ελαστικότητα του οστού επανήλθε χάρη στην αντιδιαβητική αγωγή αλλά η οστική αντοχή μειώθηκε. Η εξενατίδη είχε πιο έντονη δράση σε σχέση με τη σιταγλιπτίνη, επιβεβαιώνοντας πως η DPP4 συνδέει τη μειωμένη οστεοκλαστική δραστηριότητα με τη μειωμένη οστική παραγωγή. Συμπεράσματα: Οι DPP4 υποδοχείς είναι ένας από τους συνδετικούς κρίκους μεταξύ της μειωμένης οστικής απορρόφησης και της μειωμένης οστικής ανακατασκευής. Το συμπέρασμα που μπορεί να εξαχθεί είναι πως η αναστολή του υποδοχέα DPP4 είναι πιο βλαβερή για το οστό σε σχέση με τους αγωνιστές του GLP-1

Συγκριτική μελέτη της δράσης αντιδιαβητικών φαρμάκων στην παθογένεια της οστεοπόρωσης

Σκοπός: Σκοπός της μελέτης είναι να αποσαφηνίσει τη συσχέτιση του μονοπατιού των ινκρετινών με την παθογένεση της οστεοπόρωσης. Στην παρούσα μελέτη συγκρίνουμε δυο διαφορετικά αντιδιαβητικά φάρμακα βασισμένα στο μονοπάτι των ινκρετινών. Υλικά και μέθοδοι: Χρησιμοποιήθηκαν 40 επίμυες Wistar, οι οποίοι χωρίστηκαν μετά από τυχαιοποίηση σε 4 ομάδες. Η ομάδα 1 ήταν ομάδα control, η ομάδα 2 ήταν διαβητικά ζώα που δεν έλαβαν αγωγή, η ομάδα 3 ήταν διαβητικά ζώα στα οποία χορηγήθηκε αναστολέας του dpp4 (10 mg/kg/day) ενώ στην ομάδα 4 χορηγήθηκε αγωνιστής του glp-1 (10 μg/kg/day). Το μοντέλο του διαβήτη τύπου 2 που χρησιμοποιήθηκε για τα 30 διαβητικά ζώα βασίστηκε στη χορήγηση φρουκτόζης σε συνδυασμό με χαμηλή δόση στρεπτοζοτοκίνης. Μετά από 5 εβδομάδες θεραπείας έγινε αιμοληψία και κατόπιν θυσία των πειραματοζώων. Τα μηριαία των πειραματοζώων χρησιμοποιήθηκαν για μελέτες μηχανικής αντοχής και φασματοσκοπίας Ραμαν, ενώ το αίμα τους μελετήθηκε με μέθοδο ELISA για δείκτες οστικού σχηματισμού και απορρόφησης. Τα αριστερά μηριαία χρησιμοποιήθηκαν για παθολογανατομική μελέτη. Αποτελέσματα: Και τα δυο φάρμακα μείωσαν την οστεοκλαστική λειτουργία, ωστόσο δεν μπόρεσαν να επαναφέρουν τον οστικό επανασχηματισμό. Η συνολική επίδραση στην αντοχή του οστού ήταν απρόσμενη, καθώς η ελαστικότητα του οστού επανήλθε χάρη στην αντιδιαβητική αγωγή αλλά η οστική αντοχή μειώθηκε. Η εξενατίδη είχε πιο έντονη δράση σε σχέση με τη σιταγλιπτίνη, επιβεβαιώνοντας πως η DPP4 συνδέει τη μειωμένη οστεοκλαστική δραστηριότητα με τη μειωμένη οστική παραγωγή. Συμπεράσματα: Οι DPP4 υποδοχείς είναι ένας από τους συνδετικούς κρίκους μεταξύ της μειωμένης οστικής απορρόφησης και της μειωμένης οστικής ανακατασκευής. Το συμπέρασμα που μπορεί να εξαχθεί είναι πως η αναστολή του υποδοχέα DPP4 είναι πιο βλαβερή για το οστό σε σχέση με τους αγωνιστές του GLP-1.Introduction: The effects of incretin-based drugs, like glucagon-like peptide-1 (GLP-1) receptor agonists and inhibitors of dipeptidyl peptidase-4 (DPP-4) on bone metabolism are not completely clear yet. The aim of this study is to elucidate how the different parameters of the incretin pathway affect bone quality in terms of biomechanical properties, bone turnover and mineral properties. Materials and methods: Forty 10-week-old Wistar rats were divided in four groups: a control group, a control diabetic group, a diabetic group treated with sitagliptin, and a diabetic group treated with exenatide. Type 2 Diabetes was simulated by dietary manipulation and low dose streptozotocin and then the two different incretin-based drugs were administered. The rats were sacrificed after five weeks of therapeutic treatment. Their serum was analyzed with ELISA method for basic bone turnover markers and their right femur was subjected to three-point bending test. Finally, hematoxylin/ eosin staining in addition to RAMAN spectroscopy were employed to access the collagen and mineral properties of the bone. Results: Both incretin- based drugs reduced osteoclast function, however, they were not able to restore osteoblastic function to normal. The net effect on bone strength was surprising: bone elasticity was restored by the antidiabetic treatment, but bone strength deteriorated. Exenatide had a more pronounced effect, confirming the suspicion that DPP4 may be a linking factor between reduced osteoclastic function and reduced bone formation. Conclusion: DPP4 receptors seems to be one of the links between reduced osteoclast function and reduced bone remodeling, so DPP4 inhibition can be more detrimental to the bone than GLP-1 receptor agonists

Propagation Constant Measurement Based on a Single Transmission Line Standard Using a Two-Port VNA

This study presents a new method for measuring the propagation constant of transmission lines using a single line standard and without prior calibration of a two-port vector network analyzer (VNA). The method provides accurate results by emulating multiple line standards of the multiline calibration method. Each line standard was realized by sweeping an unknown network along a transmission line. The network need not be symmetric or reciprocal, but must exhibit both transmission and reflection. We performed measurements using a slab coaxial airline and repeated the measurements on three different VNAs. The measured propagation constant of the slab coaxial airline from all VNAs was nearly identical. By avoiding disconnecting or moving the cables, the proposed method eliminates errors related to the repeatability of connectors, resulting in improved broadband traceability to SI units

Electrically Small Spiral PIFA for Deep Implantable Devices

In this paper, a miniaturized implantable circularly polarized spiral Planar Inverted-F Antenna (SPIFA) in the UHF (600-800 MHz) band is presented. This antenna is intended for deep implantable devices such as leadless pacemakers and deep brain stimulation (DBS), which facilitates the reception of RF power from an external transmitter. The antenna is electrically small, with a volume of π × 5 m̃m x 5 m̃m × 3.2 m̃m and a diameter of 0.022λ. The performance of the proposed antenna in terms of reflection coefficient, realized gain and axial ratio are assessed when accounting for the effects of operating in different types of human body tissues, different biocompatible materials and different thicknesses and depths of the implanted antenna. Finally, the antenna is prototyped and measured in free space, a phantom model, in a cow's fat and muscle tissues to validate the simulation results, indicating good agreements. A realized gain around -20 dBm is achieved when operating in 50 mm depth in cow's muscle tissue while having electrically very small dimensions compared to implantable antennas reported in the literature

Carpometacarpal Dislocation of the Third to Fifth Fingers and an Associated Fracture of the Hamate in a Military Paratrooper

Multiple carpometacarpal dislocations with a simultaneous fracture of the hamate represent less than 1% of all injuries to the hand and wrist regions, with a scarcity of published cases. These injuries usually require a great force, and diagnosis can be missed or delayed because of the high likelihood of other severe concomitant injuries. We report a case of acute closed dislocation of the third through fifth carpometacarpal joints and an associated fracture of the hamate in a military paratrooper. The injury was caused by a wrong landing technique during parachuting. The patient was managed with primary surgical repair, and after a six-month follow-up, he has excellent functional results. The fact that both this clinical entity and the mechanism of injury are very unusual a high index of suspicion is needed, especially for orthopedic surgeons working in military hospitals. Additionally, given that there is a paucity of published cases and optional treatment is controversial, this study corroborates the superiority of surgical repair in a long-term basis

Venous thromboembolism in viral diseases: A comprehensive literature review

Abstract Venous thromboembolism (VTE) is known to be a common respiratory and/or cardiovascular complication in hospitalized patients with viral infections. Numerous studies have proven human immunodeficiency virus infection to be a prothrombotic condition. An elevated VTE risk has been observed in critically ill H1N1 influenza patients. VTE risk is remarkably higher in patients infected with the Hepatitis C virus in contrast to uninfected subjects. The elevation of D‐dimer levels supported the association between Chikungunya and the Zika virus and the rise of clinical VTE risk. Varicella‐zoster virus is a risk factor for both cellulitis and the consequent invasive bacterial disease which may take part in thrombotic initiation. Eventually, hospitalized patients infected with the coronavirus disease of 2019 (COVID‐19), the cause of the ongoing worldwide pandemic, could mainly suffer from an anomalous risk of coagulation activation with enhanced venous thrombosis events and poor quality clinical course. Although the risk of VTE in nonhospitalized COVID‐19 patients is not known yet, there are a large number of guidelines and studies on thromboprophylaxis administration for COVID‐19 cases. This study aims to take a detailed look at the effect of viral diseases on VTE, the epidemiology of VTE in viral diseases, and the diagnosis and treatment of VTE