32 research outputs found

    Evidence for the Adverse Effect of Starvation on Bone Quality: A Review of the Literature

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    Malnutrition and starvation’s possible adverse impacts on bone health and bone quality first came into the spotlight after the horrors of the Holocaust and the ghettos of World War II. Famine and food restrictions led to a mean caloric intake of 200–800 calories a day in the ghettos and concentration camps, resulting in catabolysis and starvation of the inhabitants and prisoners. Severely increased risks of fracture, poor bone mineral density, and decreased cortical strength were noted in several case series and descriptive reports addressing the medical issues of these individuals. A severe effect of severely diminished food intake and frequently concomitant calcium- and Vitamin D deficiencies was subsequently proven in both animal models and the most common cause of starvation in developed countries is anorexia nervosa. This review attempts to summarize the literature available on the impact of the metabolic response to Starvation on overall bone health and bone quality

    MTADV 5-MER peptide suppresses chronic inflammations as well as autoimmune pathologies and unveils a new potential target-Serum Amyloid A.

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    Despite the existence of potent anti-inflammatory biological drugs e.g., anti-TNF and anti IL-6 receptor antibodies, for treating chronic inflammatory and autoimmune diseases, these are costly and not specific. Cheaper oral available drugs remain an unmet need. Expression of the acute phase protein Serum Amyloid A (SAA) is dependent on release of pro-inflammatory cytokines IL-1, IL-6 and TNF-α during inflammation. Conversely, SAA induces pro-inflammatory cytokine secretion, including Th17, leading to a pathogenic vicious cycle and chronic inflammation. 5- MER peptide (5-MP) MTADV (methionine-threonine-alanine-aspartic acid-valine), also called Amilo-5MER, was originally derived from a sequence of a pro-inflammatory CD44 variant isolated from synovial fluid of a Rheumatoid Arthritis (RA) patient. This human peptide displays an efficient anti-inflammatory effects to ameliorate pathology and clinical symptoms in mouse models of RA, Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS). Bioinformatics and qRT-PCR revealed that 5-MP, administrated to encephalomyelytic mice, up-regulates genes contributing to chronic inflammation resistance. Mass spectrometry of proteins that were pulled down from an RA synovial cell extract with biotinylated 5-MP, showed that it binds SAA. 5-MP disrupted SAA assembly, which is correlated with its pro-inflammatory activity. The peptide MTADV (but not scrambled TMVAD) significantly inhibited the release of pro-inflammatory cytokines IL-6 and IL-1β from SAA-activated human fibroblasts, THP-1 monocytes and peripheral blood mononuclear cells. 5-MP suppresses the pro-inflammatory IL-6 release from SAA-activated cells, but not from non-activated cells. 5-MP could not display therapeutic activity in rats, which are SAA deficient, but does inhibit inflammations in animal models of IBD and MS, both are SAA-dependent, as shown by others in SAA knockout mice. In conclusion, 5-MP suppresses chronic inflammation in animal models of RA, IBD and MS, which are SAA-dependent, but not in animal models, which are SAA-independent

    Synovial Lipomatosis of the Glenohumeral Joint

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    Synovial lipomatosis (also known as lipoma arborescens) is a rare and benign lesion affecting synovium-lined cavities. It is characterized by hyperplasia of mature fat tissue in the subsynovial layer. Although the most commonly affected site is the knee joint, rarely additional locations such as tendon sheath and other joints are involved. We present a case of synovial lipomatosis of the glenohumeral joint in a 44-year-old man. The clinical data radiological studies and histopathologic results are described, as well as a review of the current literature

    Surface-modified nanoparticles as anti-biofilm filler for dental polymers.

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    The objective of the study was to synthesis silica nanoparticles modified with (i) a tertiary amine bearing two t-cinnamaldehyde substituents or (ii) dimethyl-octyl ammonium, alongside the well-studied quaternary ammonium polyethyleneimine nanoparticles. These were to be evaluated for their chemical and mechanical properties, as well for antibacterial and antibiofilm activity. Samples were incorporated in commercial dental resin material and the degree of monomer conversion, mechanical strength, and water contact angle were tested to characterize the effect of the nanoparticles on resin material. Antibacterial activity was evaluated with the direct contact test and the biofilm inhibition test against Streptococcus mutans. Addition of cinnamaldehyde-modified particles preserved the degree of conversion and compressive strength of the base material and increased surface hydrophobicity. Quaternary ammonium functional groups led to a decrease in the degree of conversion and to low compressive strength, without altering the hydrophilic nature of the base material. In the direct contact test and the anti-biofilm test, the polyethyleneimine particles exhibited the strongest antibacterial effect. The cinnamaldehyde-modified particles displayed antibiofilm activity, silica particles with quaternary ammonium were ineffective. Immobilization of t-cinnamaldehyde onto a solid surface via amine linkers provided a better alternative to the well-known quaternary ammonium bactericides

    Cigarette Smoking Is Associated with a Lower Concentration of CD105+ Bone Marrow Progenitor Cells

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    Cigarette smoking is associated with musculoskeletal degenerative disorders, delayed fracture healing, and nonunion. Bone marrow progenitor cells (BMPCs), known to express CD105, are important in local trophic and immunomodulatory activity and central to musculoskeletal healing/regeneration. We hypothesized that smoking is associated with lower levels of BMPC. Iliac bone marrow samples were collected from individuals aged 18–65 years during the first steps of pelvic surgery, under IRB approval with informed consent. Patients with active infectious or neoplastic disease, a history of cytotoxic or radiation therapy, primary or secondary metabolic bone disease, or bone marrow dysfunction were excluded. Separation process purity and the number of BMPCs recovered were assessed with FACS. BMPC populations in self-reported smokers and nonsmokers were compared using the two-tailed t-test. 13 smokers and 13 nonsmokers of comparable age and gender were included. The average concentration of BMPCs was 3.52 × 105/mL ± 2.45 × 105/mL for nonsmokers versus 1.31 × 105/mL ± 1.61 × 105/mL for smokers (t= 3.2, P=0.004). This suggests that cigarette smoking is linked to a significant decrease in the concentration of BMPCs, which may contribute to the reduced regenerative capacity of smokers, with implications for musculoskeletal maintenance and repair

    Tranexamic Acid Treatment Reduces Blood Loss After Elective and Semi-Urgent Reverse Total Shoulder Arthroplasty

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    Introduction Post operative blood loss after reverse shoulder arthroplasty (RSA) is associated with the need for blood transfusion and prolonged hospital stay, among other complications. Tranexamic acid (TXA) reduces perioperative blood loss and is effective when delivered systemically or locally. We compared the effects of TXA on perioperative blood loss between elective and semi-urgent RSA. Methods We retrospectively reviewed patients who underwent either elective or semi-urgent RSA for fracture repair, with and without TXA treatment. Demographics, clinical records, and laboratory results were collected and analyzed to compare peripheral blood hemoglobin concentrations before and after surgery, the need for blood transfusion, and length of hospital stay between the 2 groups. Results In a cohort of 158 patients, 91 (58%) underwent elective RSA. TXA was administered in 91 (58%) patients from the entire group. TXA administration was associated with a significant decrease in post operative hemoglobin concentration reduction in both the elective and fracture groups ( P = .026 and P = .018, respectively), a significant decrease in post operative blood transfusion rates ( P = .004 and P = .003, respectively), and a decrease in the need for prolonged hospitalization ( P = .038 and P = .009, respectively). Discussion The local application of TXA during RSA yielded a significant reduction in perioperative blood loss. We showed a significant positive effect of local TXA administration during RSA that is comparable for both elective and semi-urgent patients. Due to the baseline characteristics of fracture patients, their clinical benefits may be more notable. Conclusions The positive outcomes for surgical patients with the use of TXA during RSA can possibly cause future consideration in clinical practice

    Double-Facet Effect of Artificial Mechanical Stress on Red Blood Cell Deformability: Implications for Blood Salvage

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    The use of intra-operative blood salvage, dialysis, and artificial organs are associated with the application of non-physiological mechanical stress on red blood cells (RBCs). To explore the effect of these procedures on red cell deformability, we determined it before and after the mechanical stress application both in an in vitro system and following a blood-saving procedure. RBC from eight healthy donors and fifteen packed RBC units were subjected to mechanical stress. RBCs from five patients undergoing orthopedic surgery were also collected. We measured the percent of undeformable cells (%UDFC) in the red cell samples using our cell flow properties image analyzer, which provides the distribution of RBC deformability in a large cell population. Mechanical stress systematically reduced the cell deformability and increased the %UDFC, while simultaneously causing hemolysis of rigid, undeformable RBCs. Ultimately, the overall result depended on the initial level of the undeformable cells; the stress-induced change in the proportion of rigid cells (Δ%UDFC) increased (Δ%UDFC > 0) when its initial value was low, and decreased (Δ%UDFC < 0) when its initial value was high. This suggests that the final impact of mechanical stress on the percent of rigid cells in the RBC population is primarily determined by their initial concentration in the sample

    Sustained Release of Antibacterial Lipopeptides from Biodegradable Polymers against Oral Pathogens.

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    The development of antibacterial drugs to overcome various pathogenic species, which inhabit the oral cavity, faces several challenges, such as salivary flow and enzymatic activity that restrict dosage retention. Owing to their amphipathic nature, antimicrobial peptides (AMPs) serve as the first line of defense of the innate immune system. The ability to synthesize different types of AMPs enables exploitation of their advantages as alternatives to antibiotics. Sustained release of AMPs incorporated in biodegradable polymers can be advantageous in maintaining high levels of the peptides. In this study, four potent ultra-short lipopeptides, conjugated to an aliphatic acid chain (16C) were incorporated in two different biodegradable polymers: poly (lactic acid co castor oil) (PLACO) and ricinoleic acid-based poly (ester-anhydride) (P(SA-RA)) for sustained release. The lipopeptide and polymer formulations were tested for antibacterial activity during one week, by turbidometric measurements of bacterial outgrowth, anti-biofilm activity by live/dead staining, biocompatibility by hemolysis and XTT colorimetric assays, mode of action by fluorescence-activated cell sorting (FACS) and release profile by a fluorometric assay. The results show that an antibacterial and anti-biofilm effect, as well as membrane disruption, can be achieved by the use of a formulation of lipopeptide incorporated in biodegradable polymer

    Comparison of maximal stress at rupture and the youngs modulus.

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    <p>Unmodified resin material served as control. As can be seen, t<u>he</u> SiCial particles did not lead to a significant reduction in maximal stress or modulus. Addition of any of the quaternary ammonium-containing particles resulted in lower mechanical properties, QPEI particles causing complete destruction of the resin material.</p

    Antibiofilm test flowchart.

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    <p>Polymerized samples of modified resin material were first rinsed during 7 days. Then, samples of each one of the test groups were divided into 3 subgroups for three different biofilm models. The biofilm tests were performed using MDFR.</p
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