663 research outputs found

    Preclinical Studies on Mesenchymal Stem Cell-Based Therapy for Growth Plate Cartilage Injury Repair

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    In the last two decades, there has been a strong interest in searching for biological treatments for regeneration of injured growth plate cartilage and prevention of its bony repair. Various means have been tried, including implantation of chondrocytes, mesenchymal stem cell (MSC), together with exogenous growth factor and scaffolds, and gene therapy. However, with the lack of success with chondrocytes, more research has focussed on MSC-based treatments. In addition to circumvent limitations with MSC-based treatments (including cell harvest-associated morbidity, difficulties/time/cost involved in MSC isolation and ex vivo expansion, and potential disease transmission), mobilising endogenous MSCs to the growth plate injury site and enhancing in situ regeneration mechanisms would represent an alternative attractive approach. Further studies are required to investigate the potential particularly in large animal models or clinical setting of the ex vivo MSC approach and the feasibility of the endogenous MSC in situ approach in growth plate regeneration

    Exploring the Effectiveness of a Prevocational Seminar on Self-Efficacy and Work Motivation among Adults Residing in an Inpatient Mental Health Facility

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    Objective: This study examined a work-related intervention designed to assist people with serious mental illness (SMI) in overcoming employment barriers. Methods: A pre- post-test experimental design was used to investigate the effects of a 10-session, prevocational seminar on self-efficacy and work motivation among adults with SMI residing in an inpatient psychiatric facility. Three one-way ANCOVAs were applied to analyze post-test results for the dependent measures. Findings: Although significant findings were not found regarding the effectiveness of the prevocational seminar on self-efficacy, other interesting discoveries were made. One noteworthy outcome was persons with SMI wanted to work but experienced barriers, including discrimination, decreased motivation, and work disincentives that impeded their return to employment. Conclusions and Implications for Practice: Vocational rehabilitation (VR) counselors continue to face challenges in their efforts to increase employment among persons with SMI. The results from the present study underscore the need for skills training and innovative VR strategies to mitigate barriers to employment among persons with SMI

    Potential effects of phytoestrogen genistein in modulating acute methotrexate chemotherapy-induced osteoclastogenesis and bone damage in rats

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    Chemotherapy-induced bone damage is a frequent side effect which causes diminished bone mineral density and fracture in childhood cancer sufferers and survivors. The intensified use of anti-metabolite methotrexate (MTX) and other cytotoxic drugs has led to the need for a mechanistic understanding of chemotherapy-induced bone loss and for the development of protective treatments. Using a young rat MTX-induced bone loss model, we investigated potential bone protective effects of phytoestrogen genistein. Oral gavages of genistein (20 mg/kg) were administered daily, for seven days before, five days during, and three days after five once-daily injections (sc) of MTX (0.75 mg/kg). MTX treatment reduced body weight gain and tibial metaphyseal trabecular bone volume (p < 0.001), increased osteoclast density on the trabecular bone surface (p < 0.05), and increased the bone marrow adipocyte number in lower metaphyseal bone (p < 0.001). Genistein supplementation preserved body weight gain (p < 0.05) and inhibited ex vivo osteoclast formation of bone marrow cells from MTX-treated rats (p < 0.001). However, MTX-induced changes in bone volume, trabecular architecture, metaphyseal mRNA expression of pro-osteoclastogenic cytokines, and marrow adiposity were not significantly affected by the co-administration of genistein. This study suggests that genistein may suppress MTX-induced osteoclastogenesis; however, further studies are required to examine its potential in protecting against MTX chemotherapy-induced bone damage

    Prevention of bone growth defects, increased bone resorption and marrow adiposity with folinic acid in rats receiving long-term methotrexate

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    The underlying pathophysiology for bone growth defects in paediatric cancer patients receiving high dose methotrexate chemotherapy remains unclear and currently there are no standardized preventative treatments for patients and survivors. Using a model in young rats, we investigated damaging effects of long-term treatment with methotrexate on growth plate and metaphyseal bone, and the potential protective effects of antidote folinic acid. This study demonstrated that chronic folinic acid supplementation can prevent methotrexate-induced chondrocyte apoptosis and preserve chondrocyte columnar arrangement and number in the growth plate. In the metaphysis, folinic acid supplementation can preserve primary spongiosa heights and secondary spongiosa trabecular volume by preventing osteoblasts from undergoing apoptosis and suppressing methotrexate-induced marrow adiposity and osteoclast formation. Systemically, plasma of folinic acid supplemented rats, in comparison to plasma from rats treated with MTX alone, contained a significantly lower level of IL-1b and suppressed osteoclast formation in vitro in normal bone marrow cells. The importance of IL-1b in supporting plasma-induced osteoclast formation was confirmed as the presence of an anti-IL-1b neutralizing antibody attenuated the ability of the plasma (from MTX-treated rats) in inducing osteoclast formation. Findings from this study suggest that folinic acid supplementation during chronic methotrexate treatment can alleviate growth plate and metaphyseal damages and therefore may be potentially useful in paediatric patients who are at risk of skeletal growth suppression due to chronic methotrexate chemotherapy.Chia-Ming Fan, Bruce K. Foster, Susanta K. Hui and Cory J. Xia

    Increased dietary fiber is associated with weight loss among Full Plate Living program participants

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    IntroductionPrior studies have demonstrated that an intake of foods rich in dietary fiber is associated with a favorable impact on health status and body weight. However, the association between fiber intake and weight loss has not been well-studied in employer settings. This research aimed to assess the relationship between dietary fiber and weight loss among individuals participating in the Full Plate Living (FPL) program.MethodsThe 16-week plant-predominant fiber-rich eating program was delivered to 72 employers, primarily in the Southwest U.S., over 3 years (2017–2019). Participants received weekly video lessons, FPL materials, and additional online resources. A retrospective analysis of repeated measures was conducted using participant data obtained from 4,477 participants, of which 2,792 (62.5%) reduced body weight. Analysis of variance with post hoc analysis was used to assess the statistical significance of the changes between baseline and follow-up measures of dietary fiber intake in each of the food categories, specifically the relationship between changes in individual and combined (composite) daily servings of fruits, vegetables, whole grains, beans, and nuts on body weight measures among three groups at follow-up: those who lost, maintained, or gained weight. Multilevel modeling was used to test the hypothesis that increased intake of fiber was associated with greater weight loss.ResultsThe mean weight loss for the weight loss group was 3.28 kg. As compared to the two other groups, the intake of whole fiber-rich foods at follow-up was significantly higher among the weight loss group with fruits (2.45 servings), vegetables (2.99 servings), beans (1.03 servings), and total fiber composites (9.07 servings; P < 0.001). A significant increase in servings of grains was also noted (P < 0.05). Multilevel modeling demonstrated that a higher total fiber composite (Model 1), as well as higher intakes of either vegetables or fruits (Model 2), resulted in greater weight loss.DiscussionOur findings indicate that the FPL program can be a part of a lifestyle medicine approach to healthy eating and weight loss. Delivering the program in clinical, community, and workplace settings can increase its reach as an effective and low-cost offering

    All clinically-relevant blood components transmit prion disease following a single blood transfusion: a sheep model of vCJD

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    Variant CJD (vCJD) is an incurable, infectious human disease, likely arising from the consumption of BSE-contaminated meat products. Whilst the epidemic appears to be waning, there is much concern that vCJD infection may be perpetuated in humans by the transfusion of contaminated blood products. Since 2004, several cases of transfusion-associated vCJD transmission have been reported and linked to blood collected from pre-clinically affected donors. Using an animal model in which the disease manifested resembles that of humans affected with vCJD, we examined which blood components used in human medicine are likely to pose the greatest risk of transmitting vCJD via transfusion. We collected two full units of blood from BSE-infected donor animals during the pre-clinical phase of infection. Using methods employed by transfusion services we prepared red cell concentrates, plasma and platelets units (including leucoreduced equivalents). Following transfusion, we showed that all components contain sufficient levels of infectivity to cause disease following only a single transfusion and also that leucoreduction did not prevent disease transmission. These data suggest that all blood components are vectors for prion disease transmission, and highlight the importance of multiple control measures to minimise the risk of human to human transmission of vCJD by blood transfusion

    Mycobacterium tuberculosis Transmission from Human to Canine

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    A 71-year-old woman from Tennessee, USA with a 3-week history of a productive, nonbloody cough was evaluated. Chest radiograph showed infiltrates and atelectasis in the upper lobe of the right lung. A tuberculosis (TB) skin test resulted in a 14-mm area of induration. Sputum stained positive for acid-fast bacilli (AFB) and was positive for Mycobacterium tuberculosis by DNA probe and culture. Treatment was initiated with isoniazid, rifampicin, and pyrazinamide. After 14 days of daily, directly observed therapy, the patient complained of nausea, vomiting and diarrhoea. Treatment adjustments were made, and therapy was completed 11 months later with complete recovery. Six months after the patient\u27s TB diagnosis, she took her three and a half-year-old male Yorkshire Terrier to a veterinary clinic with cough, weight loss, and vomiting of several months\u27 duration. Initial sputum sample was negative on AFB staining. Eight days after discharge from a referral veterinary teaching hospital with a presumptive diagnosis of TB, the dog was euthanized due to urethral obstruction. Liver and tracheobronchial lymph node specimens collected at necropsy were positive for M. tuberculosis complex by polymerase chain reaction. The M. tuberculosis isolates from the dog and its owner had an indistinguishable 10-band pattern by IS6110-based restriction fragment length polymorphism genotyping

    Bovine Spongiform Encephalopathy Infectivity in Greater Kudu (Tragelaphus strepsiceros)

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    Of all the species exposed naturally to the bovine spongiform encephalopathy (BSE) agent, the greater kudu (Tragelaphus strepsiceros), a nondomesticated bovine from Africa, appears to be the most susceptible to the disease. We present the results of mouse bioassay studies to show that, contrary to findings in cattle with BSE in which the tissue distribution of infectivity is the most limited recorded for any of the transmissible spongiform encephalopathies (TSE), infectivity in greater kudu with BSE is distributed in as wide a range of tissues as occurs in any TSE. BSE agent was also detected in skin, conjunctiva, and salivary gland, tissues in which infectivity has not previously been reported in any naturally occurring TSE. The distribution of infectivity in greater kudu with BSE suggests possible routes for transmission of the disease and highlights the need for further research into the distribution of TSE infectious agents in other host species

    Possible Case of Maternal Transmission of Feline Spongiform Encephalopathy in a Captive Cheetah

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    Feline spongiform encephalopathy (FSE) is considered to be related to bovine spongiform encephalopathy (BSE) and has been reported in domestic cats as well as in captive wild cats including cheetahs, first in the United Kingdom (UK) and then in other European countries. In France, several cases were described in cheetahs either imported from UK or born in France. Here we report details of two other FSE cases in captive cheetah including a 2nd case of FSE in a cheetah born in France, most likely due to maternal transmission. Complete prion protein immunohistochemical study on both brains and peripheral organs showed the close likeness between the two cases. In addition, transmission studies to the TgOvPrP4 mouse line were also performed, for comparison with the transmission of cattle BSE. The TgOvPrP4 mouse brains infected with cattle BSE and cheetah FSE revealed similar vacuolar lesion profiles, PrPd brain mapping with occurrence of typical florid plaques. Collectively, these data indicate that they harbor the same strain of agent as the cattle BSE agent. This new observation may have some impact on our knowledge of vertical transmission of BSE agent-linked TSEs such as in housecat FSE, or vCJD

    Application of Autologous Bone Marrow Derived Mesenchymal Stem Cells to an Ovine Model of Growth Plate Cartilage Injury

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    Injury to growth plate cartilage in children can lead to bone bridge formation and result in bone growth deformities, a significant clinical problem currently lacking biological treatment. Mesenchymal stem/stromal cells (MSC) offer a promising therapeutic option for regeneration of damaged cartilage, due to their self renewing and multi-lineage differentiation attributes. Although some small animal model studies highlight the therapeutic potential of MSC for growth plate repair, translational research in large animal models, which more closely resemble the human condition, are lacking. Our laboratory has recently characterised MSCs derived from ovine bone marrow, and demonstrated these cells form cartilage-like tissue when transplanted within the gelatin sponge, Gelfoam, in vivo. In the current study, autologous bone marrow MSC were seeded into Gelfoam scaffold containing TGF-Ξ²1, and transplanted into a surgically created defect of the proximal ovine tibial growth plate. Examination of implants at 5 week post-operatively revealed transplanted autologous MSC failed to form new cartilage structure at the defect site, but contributed to an increase in formation of a dense fibrous tissue. Importantly, the extent of osteogenesis was diminished, and bone bridge formation was not accelerated due to transplantation of MSCs or the gelatin scaffold. The current study represents the first work that has utilised this ovine large animal model to investigate whether autologous bone marrow derived MSC can be used to initiate regeneration at the injured growth plate
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