342 research outputs found

    Increased muscle tension and reduced elasticity of affected muscles in recent-onset Graves' disease caused primarily by active muscle contraction

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    In 3 patients with Graves' disease of recent onset, length-tension diagrams were made during surgery for squint under eyedrop anesthesia. The affected muscles were found to be very stiff when the other eye looked straight ahead. It was expected that these stiff muscles would be able to shorten to some extent but would be unable to lengthen, due to fibrosis of the muscle. We found that the affected muscles did not shorten very much when the other eye looked into the field of action of the muscle. Unexpectedly however, they lengthenend considerably when the other eye looked out of the field of action of the muscle. This finding implies that the raised muscle tension and reduced elasticity of affected muscles in these cases of Graves' disease of recent onset were primarily caused by active muscle contraction, not by fibrosis

    A cone-plate apparatus for the in vitro biochemical and molecular analysis of the effect of shear stress on adherent cells

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    Living cells are constantly exposed to a variety of complex mechanical stimuli which are though to be critical in the control of tissue structure and function. Endothelial and smooth muscle cells in the blood vessel are ideal candidates for the study of blood flow-induced cellular regulation. We describe here a cone-plate viscometer apparatus which is specially-designed for studying the effect of fluid shear stress on large populations of adherent cells in vitro. Using conventional polystyrene tissue culture plates, the apparatus is self-contained, fits inside a standard tissue culture incubator, and provides 75–150 cm 2 of useful surface area for cell growth. This capability makes it ideal for studying gene regulation using Northern analysis, nuclear runoff transcription, transfection with reporter constructs, as well as immunochemical staining. The closed-volume design of the device is also well-suited for isotopic labelling, pharmacological studies, and for the detection of minute amounts of secreted cell products. The setup allows the use of either steady, time- and direction-varying laminar, or turbulent shear stress. We provide a detailed assembly procedure and review the method for computing shear stress magnitude and Reynolds number. Ink flow analysis, dynamic response characterization, and LDH measurements are presented to confirm the device's fluid mechanical properties and demonstrate the absence of cell injury.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43234/1/11022_2004_Article_BF00996123.pd

    Locally applied Simvastatin improves fracture healing in mice

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    <p>Abstract</p> <p>Background</p> <p>HMG-CoA reductase inhibitors, statins, are widely prescribed to lower cholesterol. High doses of orally administered simvastatin has previously been shown to improve fracture healing in a mouse femur fracture model. In this study, simvastatin was administered either subcutaneously or directly to the fracture area, with the goal of stimulating fracture repair at acceptable doses.</p> <p>Methods</p> <p>Femur fractures were produced in 70 mature male Balb-C mice and stabilized with marrow-nailing. Three experiments were performed. Firstly, 20 mice received subcutaneous injections of either simvastatin (20 mg) or vehicle. Secondly, 30 mice were divided into three groups of 10 mice receiving continuous subcutaneous delivery of the vehicle substance, the vehicle with 5 mg or with 10 mg of simvastatin per kg bodyweight per day. Finally, in 20 mice, a silicone tube was led from an osmotic mini-pump to the fracture area. In this way, 10 mice received an approximate local dose of simvastatin of 0.1 mg per kg per day for the duration of the experiment and 10 mice received the vehicle compound. All treatments lasted until the end of the experiment. Bilateral femurs were harvested 14 days post-operative. Biomechanical tests were performed by way of three-point bending. Data was analysed with ANOVA, Scheffé's post-hoc test and Student's unpaired t-test.</p> <p>Results</p> <p>With daily simvastatin injections, no effects could be demonstrated for any of the parameters examined. Continuous systemic delivery resulted in a 160% larger force at failure. Continuous local delivery of simvastatin resulted in a 170% larger force at failure as well as a twofold larger energy uptake.</p> <p>Conclusion</p> <p>This study found a dramatic positive effect on biomechanical parameters of fracture healing by simvastatin treatment directly applied to the fracture area.</p

    Force-length recording of eye muscles during local-anesthesia surgery in 32 strabismus patients

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    Abstract. Force-length recordings were made from isolated human eye muscles during strabismus surgery in local, eye-drop anesthesia in 32 adult patients. From each muscle three recordings were made: (1) while the patient looked with the other eye into the field of action of the recorded muscle, (2) looked ahead, and (3) looked out of the field of action of the recorded muscle. Non-innervated eye muscles (state 3) had an approximately exponential relation between force and length. During contraction evoked by letting the patient look ahead or into the field of action of the muscle (states I or 2), the relation between force and length was grossly linear. The approximate spring constants of horizontal rectus muscles that had not been operated on before ranged from 2 to 4 g/mm. In palsies, the degree of muscle paresis could be quantified accurately using this method and, accordingly, cases of true superior oblique palsy could be well differentiated from strabismus sursoadductorius (= upshoot in adduction) that may mimic a superior oblique palsy. In seven patients with Graves' disease of recent onset, affected muscles were found to be very stiff when the other eye looked ahead. It was expected that these stiff muscles would be able to shorten to some extent but would not be able to lengthen, due to fibrosis of the muscle. We found, however, that the affected muscles lengthened considerably when the other eye looked out of the field of action of the muscle. This implies that, in these cases of Graves' disease of recent onset, the raised muscle tension and reduced elasticity of the affected muscles and, hence, the strabismus were primarily caused by active muscle contraction, not by fibrosis

    Living Invisible: HTLV-1-Infected Persons and the Lack of Care in Public Health

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    Human T-cell lymphotropic virus type 1 (HTLV-1) infection is commonly confounded with Human Immunodeficiency Virus (HIV) infection and it is unknown to many health professionals. It is endemic in many countries and there is no effective treatment available. Although a few individuals have severe symptoms, most patients remain asymptomatic throughout their lives. Further, HTLV-1 is considered a neglected public health problem and limited studies cover specific patients' needs and emotional experiences. To better understand how women and men living with HTLV-1 experience the disease and what issues exist in their healthcare processes, we conducted a qualitative study of both symptomatic and asymptomatic patients at an outpatient clinic at the Emílio Ribas Infectious Diseases Institute in São Paulo, Brazil. We found that the main focus of health staff was on illness risk, but not identifying infected relatives and preventing new infections. This point of view, ultimately neglected patients' complex demands, and overshadows the prevention of new infections and contributes to the lack of care in public health for HTLV-1 infected subjects. Furthermore, this perpetuates the infection among these populations and the patients experience an “invisibility” of their specific needs, such as reproductive rights and feel that their rights as citizens are ignored

    Spherical Lactic Acid Bacteria Activate Plasmacytoid Dendritic Cells Immunomodulatory Function via TLR9-Dependent Crosstalk with Myeloid Dendritic Cells

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    Plasmacytoid dendritic cells (pDC) are a specialized sensor of viral and bacterial nucleic acids and a major producer of IFN-α that promotes host defense by priming both innate and acquired immune responses. Although synthetic Toll-like receptor (TLR) ligands, pathogenic bacteria and viruses activate pDC, there is limited investigation of non-pathogenic microbiota that are in wide industrial dietary use, such as lactic acid bacteria (LAB). In this study, we screened for LAB strains, which induce pDC activation and IFN-α production using murine bone marrow (BM)-derived Flt-3L induced dendritic cell culture. Microbial strains with such activity on pDC were absent in a diversity of bacillary strains, but were observed in certain spherical species (Lactococcus, Leuconostoc, Streptococcus and Pediococcus), which was correlated with their capacity for uptake by pDC. Detailed study of Lactococcus lactis subsp. lactis JCM5805 and JCM20101 revealed that the major type I and type III interferons were induced (IFN-α, -β, and λ). IFN-α induction was TLR9 and MyD88-dependent; a slight impairment was also observed in TLR4-/- cells. While these responses occurred with purified pDC, IFN-α production was synergistic upon co-culture with myeloid dendritic cells (mDC), an interaction that required direct mDC-pDC contact. L. lactis strains also stimulated expression of immunoregulatory receptors on pDC (ICOS-L and PD-L1), and accordingly augmented pDC induction of CD4+CD25+FoxP3+ Treg compared to the Lactobacillus strain. Oral administration of L. lactis JCM5805 induced significant activation of pDC resident in the intestinal draining mesenteric lymph nodes, but not in a remote lymphoid site (spleen). Taken together, certain non-pathogenic spherical LAB in wide dietary use has potent and diverse immunomodulatory effects on pDC potentially relevant to anti-viral immunity and chronic inflammatory disease
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