58 research outputs found
Walking with a Posterior Cruciate Ligament Injury: A Musculoskeletal Model Study
The understanding of the changes induced in the kneeâs kinematics by a Posterior Cruciate
Ligament (PCL) injury is still rather incomplete. This computational study aimed to analyze how the
internal loads are redistributed among the remaining ligaments when the PCL is lesioned at different
degrees and to understand if there is a possibility to compensate for a PCL lesion by changing the
hamstringâs contraction in the second half of the swing phase. A musculoskeletal model of the knee
joint was used for simulating a progressive PCL injury by gradually reducing the ligament stiffness.
Then, in the model with a PCL residual stiffness at 15%, further dynamic simulations of walking were
performed by progressively reducing the hamstringâs force. In each condition, the ligaments tension,
contact force and knee kinematics were analyzed. In the simulated PCL-injured knee, the Medial
Collateral Ligament (MCL) became the main passive stabilizer of the tibial posterior translation, with
synergistic recruitment of the Lateral Collateral Ligament. This resulted in an enhancement of the
tibialâfemoral contact force with respect to the intact knee. The reduction in the hamstringâs force
limited the tibial posterior sliding and, consequently, the tension of the ligaments compensating for
PCL injury decreased, as did the tibiofemoral contact force. This study does not pretend to represent
any specific population, since our musculoskeletal model represents a single subject. However, the
implemented model could allow the non-invasive estimation of load redistribution in cases of PCL
injury. Understanding the changes in the knee joint biomechanics could help clinicians to restore
patientsâ joint stability and prevent joint degeneration
Women performing repetitive work: Is there a difference in the prevalence of shoulder pain and pathology in supermarket cashiers compared to the general female population?
Objectives: Shoulder disorders in the occupational environment have been widely studied, but the quality of research and methodology applied vary. Little has been done to ascertain whether shoulder pain in female repetitive workers is due to any verifiable pathology, or to compare findings with the general population. Therefore, we decided to evaluate the prevalence of self-reported shoulder pain in a group of female supermarket cashiers and in the general female population using a standardized questionnaire. Shoulder pain prevalence was then compared to imaging findings in order to assess specific and non-specific pain prevalence. Material and Methods: 196 cashiers and 302 controls filled in a standardized shoulder questionnaire and underwent an imaging examination of a shoulder. Results: The prevalence of shoulder pain was significantly higher in the group of cashiers (46.4%) than in the general population (25.5%) (OR = 1.821; 95% CI: 1.426â2.325). Specific pain prevalence was higher among the controls (19.5%) than among the cashiers (13.2%). Conclusions: The more frequent reports of shoulder pain in the supermarket cashiers are not correlated with a higher prevalence of imaging abnormalities. The causes of these more frequent complaints should be probably sought in the psycho-social and occupational environment
Donor-matched mesenchymal stem cells from knee infrapatellar and subcutaneous adipose tissue of osteoarthritic donors display differential chondrogenic and osteogenic commitment.
Cell-based therapies have recently been proposed for the treatment of degenerative articular pathologies, such as early osteoarthritis, with an emphasis on autologous mesenchymal stem cells (MSCs), as an alternative to terminally differentiated cells. In this study, we performed a donor-matched comparison between infrapatellar fat pad MSCs (IFP-MSCs) and knee subcutaneous adipose tissue stem cells (ASCs), as appealing candidates for cell-based therapies that are easily accessible during surgery. IFP-MSCs and ASCs were obtained from 25 osteoarthritic patients undergoing total knee replacement and compared for their immunophenotype and differentiative potential. Undifferentiated IFP-MSCs and ASCs displayed the same immunophenotype, typical of MSCs (CD13+/CD29+/CD44+/CD73+/CD90+/CD105+/CD166+/CD31-/CD45-). IFP-MSCs and ASCs showed similar adipogenic potential, though undifferentiated ASCs had higher LEP expression compared to IFP-MSCs (p < 0.01). Higher levels of calcified matrix (p < 0.05) and alkaline phosphatase (p < 0.05) in ASCs highlighted their superior osteogenic commitment compared to IFP-MSCs. Conversely, IFP-MSCs pellets showed greater amounts of glycosaminoglycans (p < 0.01) and superior expression of ACAN (p < 0.001), SOX9, COMP (p < 0.001) and COL2A1 (p < 0.05) compared to ASCs pellets, revealing a superior chondrogenic potential. This was also supported by lower COL10A1 (p < 0.05) and COL1A1 (p < 0.01) expression and lower alkaline phosphatase release (p < 0.05) by IFP-MSCs compared to ASCs. The observed dissimilarities between IFP-MSCs and ASCs show that, despite expressing similar surface markers, MSCs deriving from different fat depots in the same surgical site possess specific features. Furthermore, the in vitro peculiar commitment of IFP-MSCs and ASCs from osteoarthritic donors towards the chondrogenic or osteogenic lineage may suggest a preferential use for cartilage and bone cell-based treatments, respectively
Probing the therapeutic potential of marine phyla by spe extraction
The marine environment is potentially a prolific source of small molecules with significant biological activities. In recent years, the development of new chromatographic phases and the progress in cell and molecular techniques have facilitated the search for marine natural products (MNPs) as novel pharmacophores and enhanced the success rate in the selection of new potential drug candidates. However, most of this exploration has so far been driven by anticancer research and has been limited to a reduced number of taxonomic groups. In this article, we report a test study on the screening potential of an in-house library of natural small molecules composed of 285 samples derived from 57 marine organisms that were chosen from among the major eukaryotic phyla so far represented in studies on bioactive MNPs. Both the extracts and SPE fractions of these organisms were simultaneously submitted to three different bioassaysâtwo phenotypic and one enzymaticâfor cytotoxic, antidiabetic, and antibacterial activity. On the whole, the screening of the MNP library selected 11 potential hits, but the distribution of the biological results showed that SPE fractionation increased the positive score regardless of the taxonomic group. In many cases, activity could be detected only in the enriched fractions after the elimination of the bulky effect due to salts. On a statistical basis, sponges and molluscs were confirmed to be the most significant source of cytotoxic and antimicrobial products, but other phyla were found to be effective with the other therapeutic target
Acute Delta Hepatitis in Italy spanning three decades (1991â2019): Evidence for the effectiveness of the hepatitis B vaccination campaign
Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come
Women performing repetitive work: Is there a difference in the prevalence of shoulder pain and pathology in supermarket cashiers compared to the general female population?
Objectives: Shoulder disorders in the occupational environment have been widely studied, but the quality of research and methodology applied vary. Little has been done to ascertain whether shoulder pain in female repetitive workers is due to any verifiable pathology, or to compare findings with the general population. Therefore, we decided to evaluate the prevalence of self-reported shoulder pain in a group of female supermarket cashiers and in the general female population using a standardized questionnaire. Shoulder pain prevalence was then compared to imaging findings in order to assess specific and non-specific pain prevalence. Material and Methods: 196 cashiers and 302 controls filled in a standardized shoulder questionnaire and underwent an imaging examination of a shoulder. Results: The prevalence of shoulder pain was significantly higher in the group of cashiers (46.4%) than in the general population (25.5%) (OR = 1.821; 95% CI: 1.426â2.325). Specific pain prevalence was higher among the controls (19.5%) than among the cashiers (13.2%). Conclusions: The more frequent reports of shoulder pain in the supermarket cashiers are not correlated with a higher prevalence of imaging abnormalities. The causes of these more frequent complaints should be probably sought in the psycho-social and occupational environment
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Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial
Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index â„35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users
A novel bimodal approach for treating atrophic bone non unions with extracorporeal shockwaves and autologous mesenchymal stem cell transplant
We propose a novel approach for the treatment of atrophic bone non-unions via parallel applications of extracorporeal shock wave therapy (ESWT) and an autologous mesenchymal stem cell transplant. The hypothesis resides on the potentiality of shock waves (SWs) to act as a tool for manipulating the patient's mesenchymal stem cells (MSCs). In addition to the conventional physical stimulus achieved by delivering SWs at the site of non-union to stimulate the well-known trophic effects on bone tissue, a series of concomitant ESWT would be administered in tandem at a bone marrow donor site, such as the iliac crest, to precondition resident bone marrow stromal cells (BMSCs) in vivo, priming resident MSCs by enlarging and conditioning their population prior to bone marrow aspiration. The resulting sample could then be treated to further augment cell concentration and injected, under fluoroscopic control, into the non-union site through a percutaneous approach
The effects on bone cells of metal ions released from orthopaedic implants. A review
The increasing use of orthopedic implants and, in particular, of hip and knee joint replacements for young and active patients, has stimulated interest and concern regarding the chronic, long-term effects of the materials used. This review focuses on the current knowledge of the adverse biologic reactions to metal particles released from orthopaedic implants in vivo and in vitro. More specifically, the purpose of this article is to provide an overview of the current literature about the adverse effects of metal particles on bone cells and peri-implant bon
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