47 research outputs found

    On A Search For Voice

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    The search for voice is a crucial part of feminist theory. Voice is based on both self-definition and interactions with communities. One challenge is to delineate between outside sources that hinder and foster growth in voice. Sharing personal experiences is crucial in understanding voice. A journey of voice is demonstrated through reading and writingLa recherche pour une voix est une partie cruciale de la theorie feministe. La vox est basee et sur la quete de soi et sur les interactions avec les communautes. Un defi se detache des sources extemes qui entravent ou qui encouragent le developpement dans la voix. Le partage d'experiences personnelles est crucial a la comprehension de la voix. Un parcours de la voix est decrit a travers la lecture et l'ecriture

    Testing In Vivo the Comparability of Two Different Scaffolds in Alveolar Ridge Preservation Against Geistlich Bio-Oss@ Xenograft and Control in the Rat Model

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    . Aim: Ridge preservation is a common procedure performed in Periodontics to prevent ridge resorption following tooth extraction. The aim of this present investigation is to compare in vivo the use of bioengineered Polycaprolactone (Polydopamine Coated and Uncoated) scaffolds against a commonly used xenograft, Bio-Oss@, and Control (no material) in ridge preservation procedures following first molar extraction in the rat model. Materials and Methods: 33 male Sprague Dawley rats were used in the study. The maxillary right and left first molars were extracted and a standardized defect was created in the extraction socket using a slow speed handpiece and a #703 fissure bur. The rats were equally divided and randomly selected to receive one of four ridge preservation materials: Control (no material), Bio-Oss@, Polycaprolactone (Polydopamine Coated) scaffold, or Polycaprolactone (Uncoated) scaffold. All extraction sites were covered by a resorbable collagen membrane. Rats were randomly allocated to either be in the four week or eight week experimental groups. The rats were sacrificed, and the maxillae were dissected and hemisected into right and left halves. The tissues were processed and analyzed. Results: In comparing radiographs, at 4 weeks, the difference in average bone height at extraction sockets was not statistically significant (p > 0.05) for any of the materials tested. At 8 weeks, the difference in average bone height at extraction sockets was statistically significant (p < 0.05) between Control and Bio-Oss@, Polycaprolactone (Uncoated), and Polycaprolactone (Polydopamine Coated). Micro-CT analysis revealed greater bone fill in the extraction sockets in the 8-week samples compared with the 4-week samples, and all samples showed a loss of residual bone height. Paraffin sections demonstrated that Control, Bio-Oss@, and Polycaprolactone (Uncoated) healed by direct ossification while Polycaprolactone (Polydopamine Coated) healed by endochondral ossification. New mineralized tissue formation was seen inside the fibrous connective tissue in all 8-week ground section samples. Conclusion: Both Polycaprolactone (Polydopamine Coated and Uncoated) scaffolds performed comparably to Bio-Oss@ as a ridge preservation material over the Control (no material). Though new bone formation was seen with all treatment modalities, there was an improvement seen in using grafts over not using a graft

    Frailty increases the long-term risk for fall and fracture-related hospitalizations and all-cause mortality in community-dwelling older women

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    Frailty is associated with declines in physiological capacity across sensory, neurological, and musculoskeletal systems. An underlying assumption is that the frailer an individual, the more likely they are to experience falls and fractures. We examined whether grades of frailty can assess the long-term risk of hospitalized falls, fractures, and all-cause mortality in 1261 community-dwelling older women (mean age [SD] of 75.1 [2.7] yr) over 14.5 yr. Frailty was operationalized using a frailty index (FI) of cumulative deficits from 33 variables across multiple health domains (physical, mental, comorbidities) at baseline. The total score across these variables was summed and divided by 33 to obtain the FI. Participants were graded as fit (FI ≤ 0.12), mildly frail (FI \u3e 0.12-0.24), moderately frail (FI \u3e 0.24-0.36), or severely frail (FI \u3e 0.36). Fall-related (n = 498), any fracture-related (n = 347), and hip fracture-related hospitalizations (n = 137) and deaths (n = 482) were obtained from linked health records. Associations between FI grades and clinical outcomes were analyzed using multivariable-adjusted Cox-proportional hazard models including age, treatment (calcium/placebo), BMI, smoking history, socioeconomic status, plasma vitamin D (25OHD) status plus season obtained, physical activity, self-reported prevalent falls in the last 3 mo, and self-reported fractures since the age of 50 yr. At baseline, 713 (56.5%), 350 (27.8%), 163 (12.9%), and 35 (2.8%) of women were classified as fit, mildly frail, moderately frail, and severely frail, respectively. Women with mild, moderate, and severe frailty had significantly higher hazards (all P \u3c .05) for a fall-related (46%, 104%, 168%), any fracture-related (88% for moderate, 193% for severe frailty), hip fracture-related hospitalizations (93%, 127%, 129%), and all-cause mortality (47%, 126%, 242%). The FI identified community-dwelling older women at risk for the most serious falls and fractures and may be incorporated into risk assessment tools to identify individuals with poorer clinical prognosis

    Different effects of deep inspirations on central and peripheral airways in healthy and allergen-challenged mice

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    <p>Abstract</p> <p>Background</p> <p>Deep inspirations (DI) have bronchodilatory and bronchoprotective effects in healthy human subjects, but these effects appear to be absent in asthmatic lungs. We have characterized the effects of DI on lung mechanics during mechanical ventilation in healthy mice and in a murine model of acute and chronic airway inflammation.</p> <p>Methods</p> <p>Balb/c mice were sensitized to ovalbumin (OVA) and exposed to nebulized OVA for 1 week or 12 weeks. Control mice were challenged with PBS. Mice were randomly selected to receive DI, which were given twice during the minute before assessment of lung mechanics.</p> <p>Results</p> <p>DI protected against bronchoconstriction of central airways in healthy mice and in mice with acute airway inflammation, but not when OVA-induced chronic inflammation was present. DI reduced lung resistance induced by methacholine from 3.8 ± 0.3 to 2.8 ± 0.1 cmH<sub>2</sub>O·s·mL<sup>-1 </sup>in healthy mice and 5.1 ± 0.3 to 3.5 ± 0.3 cmH<sub>2</sub>O·s·mL<sup>-1 </sup>in acute airway inflammation (both <it>P </it>< 0.001). In healthy mice, DI reduced the maximum decrease in lung compliance from 15.9 ± 1.5% to 5.6 ± 0.6% (<it>P </it>< 0.0001). This protective effect was even more pronounced in mice with chronic inflammation where DI attenuated maximum decrease in compliance from 44.1 ± 6.6% to 14.3 ± 1.3% (<it>P </it>< 0.001). DI largely prevented increased peripheral tissue damping (G) and tissue elastance (H) in both healthy (G and H both <it>P </it>< 0.0001) and chronic allergen-treated animals (G and H both <it>P </it>< 0.0001).</p> <p>Conclusion</p> <p>We have tested a mouse model of potential value for defining mechanisms and sites of action of DI in healthy and asthmatic human subjects. Our current results point to potent protective effects of DI on peripheral parts of chronically inflamed murine lungs and that the presence of DI may blunt airway hyperreactivity.</p

    Intranasal Administration of poly(I:C) and LPS in BALB/c Mice Induces Airway Hyperresponsiveness and Inflammation via Different Pathways

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    BACKGROUND: Bacterial and viral infections are known to promote airway hyperresponsiveness (AHR) in asthmatic patients. The mechanism behind this reaction is poorly understood, but pattern recognizing Toll-like receptors (TLRs) have recently been suggested to play a role. MATERIALS AND METHODS: To explore the relation between infection-induced airway inflammation and the development of AHR, poly(I:C) activating TLR3 and LPS triggering TLR4, were chosen to represent viral and bacterial induced interactions, respectively. Female BALB/c or MyD88-deficient C57BL/6 mice were treated intranasally with either poly(I:C), LPS or PBS (vehicle for the control group), once a day, during 4 consecutive days. RESULTS: When methacholine challenge was performed on day 5, BALB/c mice responded with an increase in airway resistance. The maximal resistance was higher in the poly(I:C) and LPS treated groups than among the controls, indicating development of AHR in response to repeated TLR activation. The proportion of lymphocytes in broncheoalveolar lavage fluid (BALF) increased after poly(I:C) treatment whereas LPS enhanced the amount of neutrophils. A similar cellular pattern was seen in lung tissue. Analysis of 21 inflammatory mediators in BALF revealed that the TLR response was receptor-specific. MyD88-deficient C57BL/6 mice responded to poly (I:C) with an influx of lymphocytes, whereas LPS caused no inflammation. CONCLUSION: In vivo activation of TLR3 and TLR4 in BALB/c mice both caused AHR in conjunction with a local inflammatory reaction. The AHR appeared to be identical regardless of which TLR that was activated, whereas the inflammation exhibited a receptor specific profile in terms of both recruited cells and inflammatory mediators. The inflammatory response caused by LPS appeared to be dependent on MyD88 pathway. Altogether the presented data indicate that the development of AHR and the induction of local inflammation might be the result of two parallel events, rather than one leading to another

    The role of endothelin-1 in hyperoxia-induced lung injury in mice

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    BACKGROUND: As prolonged hyperoxia induces extensive lung tissue damage, we set out to investigate the involvement of endothelin-1 (ET-1) receptors in these adverse changes. METHODS: Experiments were performed on four groups of mice: control animals kept in room air and a group of mice exposed to hyperoxia for 60 h were not subjected to ET-1 receptor blockade, whereas the dual ETA/ETB-receptor blocker tezosantan (TEZ) was administered via an intraperitoneal pump (10 mg/kg/day for 6 days) to other groups of normal and hyperoxic mice. The respiratory system impedance (Zrs) was measured by means of forced oscillations in the anesthetized, paralyzed and mechanically ventilated mice before and after the iv injection of ET-1 (2 μg). Changes in the airway resistance (Raw) and in the tissue damping (G) and elastance (H) of a constant-phase tissue compartment were identified from Zrs by model fitting. RESULTS: The plasma ET-1 level increased in the mice exposed to hyperoxia (3.3 ± 1.6 pg/ml) relative to those exposed to room air (1.6 ± 0.3 pg/ml, p < 0.05). TEZ administration prevented the hyperoxia-induced increases in G (13.1 ± 1.7 vs. 9.6 ± 0.3 cmH(2)O/l, p < 0.05) and H (59 ± 9 vs. 41 ± 5 cmH(2)O/l, p < 0.05) and inhibited the lung responses to ET-1. Hyperoxia decreased the reactivity of the airways to ET-1, whereas it elevated the reactivity of the tissues. CONCLUSION: These findings substantiate the involvement of the ET-1 receptors in the physiopathogenesis of hyperoxia-induced lung damage. Dual ET-1 receptor antagonism may well be of value in the prevention of hyperoxia-induced parenchymal damage

    Hyperresponsiveness to inhaled but not intravenous methacholine during acute respiratory syncytial virus infection in mice

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    BACKGROUND: To characterise the acute physiological and inflammatory changes induced by low-dose RSV infection in mice. METHODS: BALB/c mice were infected as adults (8 wk) or weanlings (3 wk) with 1 × 10(5 )pfu of RSV A2 or vehicle (intranasal, 30 μl). Inflammation, cytokines and inflammatory markers in bronchoalveolar lavage fluid (BALF) and airway and tissue responses to inhaled methacholine (MCh; 0.001 – 30 mg/ml) were measured 5, 7, 10 and 21 days post infection. Responsiveness to iv MCh (6 – 96 μg/min/kg) in vivo and to electrical field stimulation (EFS) and MCh in vitro were measured at 7 d. Epithelial permeability was measured by Evans Blue dye leakage into BALF at 7 d. Respiratory mechanics were measured using low frequency forced oscillation in tracheostomised and ventilated (450 bpm, flexiVent) mice. Low frequency impedance spectra were calculated (0.5 – 20 Hz) and a model, consisting of an airway compartment [airway resistance (Raw) and inertance (Iaw)] and a constant-phase tissue compartment [coefficients of tissue damping (G) and elastance (H)] was fitted to the data. RESULTS: Inflammation in adult mouse BALF peaked at 7 d (RSV 15.6 (4.7 SE) vs. control 3.7 (0.7) × 10(4 )cells/ml; p < 0.001), resolving by 21 d, with no increase in weanlings at any timepoint. RSV-infected mice were hyperresponsive to aerosolised MCh at 5 and 7 d (PC(200 )Raw adults: RSV 0.02 (0.005) vs. control 1.1 (0.41) mg/ml; p = 0.003) (PC(200 )Raw weanlings: RSV 0.19 (0.12) vs. control 10.2 (6.0) mg/ml MCh; p = 0.001). Increased responsiveness to aerosolised MCh was matched by elevated levels of cysLT at 5 d and elevated VEGF and PGE(2 )at 7 d in BALF from both adult and weanling mice. Responsiveness was not increased in response to iv MCh in vivo or EFS or MCh challenge in vitro. Increased epithelial permeability was not detected at 7 d. CONCLUSION: Infection with 1 × 10(5 )pfu RSV induced extreme hyperresponsiveness to aerosolised MCh during the acute phase of infection in adult and weanling mice. The route-specificity of hyperresponsiveness suggests that epithelial mechanisms were important in determining the physiological effects. Inflammatory changes were dissociated from physiological changes, particularly in weanling mice
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