158 research outputs found

    Age-dependent Changes in the Articular Cartilage and Subchondral Bone of C57BL/6 Mice after Surgical Destabilization of Medial Meniscus

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    Age is the primary risk factor for osteoarthritis (OA), yet surgical OA mouse models such as destabilization of the medial meniscus (DMM) used for evaluating disease-modifying OA targets are frequently performed on young adult mice only. This study investigates how age affects cartilage and subchondral bone changes in mouse joints following DMM. DMM was performed on male C57BL/6 mice at 4 months (4 M), 12 months (12 M) and 19+ months (19 M+) and on females at 12 M and 18 M+. Two months after surgery, operated and unoperated contralateral knees were harvested and evaluated using cartilage histology scores and muCT quantification of subchondral bone plate thickness and osteophyte formation. The 12 M and 19 M+ male mice developed more cartilage erosions and thicker subchondral bone plates after DMM than 4 M males. The size of osteophytes trended up with age, while the bone volume fraction was significantly higher in the 19 M+ group. Furthermore, 12 M females developed milder OA than males as indicated by less cartilage degradation, less subchondral bone plate sclerosis and smaller osteophytes. Our results reveal distinct age/gender-dependent structural changes in joint cartilage and subchondral bone post-DMM, facilitating more thoughtful selection of murine age/gender when using this surgical technique for translational OA research

    Vancomycin-bearing Synthetic Bone Graft Delivers rhBMP-2 and Promotes Healing of Critical Rat Femoral Segmental Defects

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    For graft-assisted repair of large volumetric bone loss resulting from traumatic orthopedic injuries, strategies that simultaneously promote osteointegration/graft healing and mitigate risks for infections are highly desired. Previously, we developed a poly(2-hydroxyethyl methacrylate)-nanocrystalline hydroxyapatite (pHEMA-nHA) composite as a synthetic bone graft. The composite, when loaded with a single dose of 400-ng rhBMP-2/7 and press-fit into a 5-mm rat femoral segmental defect, led to bony callus fully bridging over the defect and substantial restoration of the torsional rigidity by 12 weeks. More recently, we showed that 4.8 wt% vancomycin can be encapsulated within the composite without compromising the structural and mechanical integrity. Additionally, FDA-approved rhBMP-2 can be absorbed onto the graft and both the vancomycin and rhBMP-2 can be released in a localized and sustained manner. Here we examine the efficacy of pHEMA-nHA-vancomycin grafts pre-absorbed with rhBMP-2 in repairing 5-mm rat femoral segmental defects, and determine if vancomycin hinders the repair. pHEMA-nHA-vancomycin or pHEMA-nHA with/without 3-µg rhBMP-2 were press-fit in 5-mm femoral defects in male rats. Histology, microcomputed tomography, and torsion testing were performed on 12-week explants to evaluate the extent and quality of repair. Partial bridging of the defect with bony callus by 12 weeks was observed with pHEMA-nHA-vancomycin without rhBMP-2 while full bridging with substantially mineralized callus and partial restoration of torsional strength was achieved with 3-µg rhBMP-2. The presence of vancomycin did not significantly compromise graft healing. The pHEMA-nHA-vancomycin graft, with the ability to deliver safe doses of osteogenic recombinant proteins and to simultaneously release the encapsulated antibiotics in a sustained manner holds promise in improving the clinical outcome of graft-assisted repair of traumatic bone injuries

    Foreign-funded adaptation to climate change in Africa: mirroring administrative traditions or traditions of administrative blueprinting?

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    Climate change impacts are most severe in developing countries with limited adaptive capacity. Accordingly, in Africa, climate change adaptation has become an issue of international funding and practice. As suggested in the Introduction to this special issue, administrative traditions could play a role in how adaptation plays out. This, however, raises questions about how foreign funding regimes coincide with recipients’ administrative traditions, especially on the African continent where administrative traditions are often meagerly established. To address these questions, this article takes an explorative approach. From a literature review of African state governance and development aid approaches, we take colonial legacy as the most distinctive factor responsible for African administrative traditions. In addition, we define three ways in which foreign aid programs have dealt with African administration: (1) aligning with donor administration, (2) blueprinting administration, and (3) ignoring administration. Using 34 African countries’ National Adaptation Programmes of Action(NAPAs), we analyze how African governments actually frame adaptation as a governance challenge. We contrast these frames with: (1) administrative traditions based on colonial legacy and (2) the ways in which development aid programs have historically dealt with recipient African administrations. Our findings indicate that NAPAs only meagerly refer to the administrative tradition that could be expected based on colonial legacy, but extensively refer to blueprint ideas common among international donors, or ignore administration altogether. We discuss the implications for adaptation to climate change

    Understanding emotionally relevant situations in primary dental practice. 2. Reported effects of emotionally charged situations

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    Background and aims. Dentistry is widely reported to be a stressful profession. There is a limited body of research relating to the coping strategies used by dentists whilst in clinical situations. This study aims to use qualitative methods to explore the full extent of the coping strategies associated with stressful events in primary dental practice. Method. Semi-structured interviews were conducted with 20 dentists within a 50 mile radius of Lincoln. A thematic analysis was conducted on verbatim transcriptions thereby identifying six themes and 35 codes. Results. Participants described both problem-focused and emotion-focused strategies. The strategies used had a variety of outcomes in the context of use. Most dentists denied that their emotions affected their decision-making, but then proceeded to describe how they were influential. Discussion and conclusion. Dentists use a wide variety of coping strategies some of which are maladaptive. Training in the development and recognition of appropriate coping decisions would be appropriate as they woul

    Health Disparities Between Appalachian and Non-Appalachian Counties in Virginia USA

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    The examination of health disparities among people within Appalachian counties compared to people living in other counties is needed to find ways to strategically target improvements in community health in the United States of America (USA). Methods: A telephone survey of a random sample of adults living in households within communities of all counties of the state of Virginia (VA) in the USA was conducted. Findings: Health status was poorer among those in communities within Appalachian counties in VA and health insurance did not make a difference. Health perception was significantly worse in residents within communities in Appalachian counties compared to non-Appalachian community residents (30.5 vs. 17.4% rated their health status as poor/fair), and was worse even among those with no chronic diseases. Within communities in Appalachian counties, black residents report significantly better health perception than do white residents. Conclusion: Residents living in communities in Appalachian counties in VA are not receiving adequate health care, even among those with health insurance. More research with a larger ethnic minority sample is needed to investigate the racial/ethnic disparities in self-reported health and health care utilization within communities

    Deception and decay: Verbal lie detection as a function of delay and encoding quality

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    We examined the effect of encoding quality and retention interval on the verbal accounts of truth tellers and liars. Truthful and deceptive participants (n = 149) reported a social interaction immediately or after a three-week delay. To manipulate encoding quality, the content of the exchange was important for, and intentionally attended to by, all liars and half of truth tellers (intentional encoding) but unimportant for half of truth tellers (incidental encoding). In the immediate condition, truth tellers in the intentional condition reported more details than liars and truth tellers in the incidental condition. All truth tellers reported fewer details after a delay (cf. immediately) whereas liars reported equivalent detail at both retrieval intervals. No differences by veracity group emerged in detail reported after delay. The oft-reported finding that truth tellers provide more detail than liars holds true when the event is intentionally encoded by truth tellers who are interviewed without delay

    Provenance of Cretaceous through Eocene strata of the Four Corners region: Insights from detrital zircons in the San Juan Basin, New Mexico and Colorado

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    Cretaceous through Eocene strata of the Four Corners region provide an excellent record of changes in sediment provenance from Sevier thin-skinned thrusting through the formation of Laramide block uplifts and intra-foreland basins. During the ca. 125–50 Ma timespan, the San Juan Basin was flanked by the Sevier thrust belt to the west, the Mogollon highlands rift shoulder to the southwest, and was influenced by (ca. 75–50 Ma) Laramide tectonism, ultimately preserving a >6000 ft (>2000 m) sequence of continental, marginal-marine, and offshore marine sediments. In order to decipher the influences of these tectonic features on sediment delivery to the area, we evaluated 3228 U-Pb laser analyses from 32 detrital-zircon samples from across the entire San Juan Basin, of which 1520 analyses from 16 samples are newly reported herein. The detrital-zircon results indicate four stratigraphic intervals with internally consistent age peaks: (1) Lower Cretaceous Burro Canyon Formation, (2) Turonian (93.9–89.8 Ma) Gallup Sandstone through Campanian (83.6–72.1 Ma) Lewis Shale, (3) Campanian Pictured Cliffs Sandstone through Campanian Fruitland Formation, and (4) Campanian Kirtland Sandstone through Lower Eocene (56.0–47.8 Ma) San Jose Formation. Statistical analysis of the detrital-zircon results, in conjunction with paleocurrent data, reveals three distinct changes in sediment provenance. The first transition, between the Burro Canyon Formation and the Gallup Sandstone, reflects a change from predominantly reworked sediment from the Sevier thrust front, including uplifted Paleozoic sediments and Mesozoic eolian sandstones, to a mixed signature indicating both Sevier and Mogollon derivation. Deposition of the Pictured Cliffs Sandstone at ca. 75 Ma marks the beginning of the second transition and is indicated by the spate of near-depositional-age zircons, likely derived from the Laramide porphyry copper province of southern Arizona and southwestern New Mexico. Paleoflow indicators suggest the third change in provenance was complete by 65 Ma as recorded by the deposition of the Paleocene Ojo Alamo Sandstone. However, our new U-Pb detrital-zircon results indicate this transition initiated ∼8 m.y. earlier during deposition of the Campanian Kirtland Formation beginning ca. 73 Ma. This final change in provenance is interpreted to reflect the unroofing of surrounding Laramide basement blocks and a switch to local derivation. At this time, sediment entering the San Juan Basin was largely being generated from the nearby San Juan Mountains to the north-northwest, including uplift associated with early phases of Colorado mineral belt magmatism. Thus, the detrital-zircon spectra in the San Juan Basin document the transition from initial reworking of the Paleozoic and Mesozoic cratonal blanket to unroofing of distant basement-cored uplifts and Laramide plutonic rocks, then to more local Laramide uplifts.National Science Foundation (NSF grant EAR-1649254

    Pain acceptance and personal control in pain relief in two maternity care models: a cross-national comparison of Belgium and the Netherlands

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    <p>Abstract</p> <p>Background</p> <p>A cross-national comparison of Belgian and Dutch childbearing women allows us to gain insight into the relative importance of pain acceptance and personal control in pain relief in 2 maternity care models. Although Belgium and the Netherlands are neighbouring countries sharing the same language, political system and geography, they are characterised by a different organisation of health care, particularly in maternity care. In Belgium the medical risks of childbirth are emphasised but neutralised by a strong belief in the merits of the medical model. Labour pain is perceived as a needless inconvenience easily resolved by means of pain medication. In the Netherlands the midwifery model of care defines childbirth as a normal physiological process and family event. Labour pain is perceived as an ally in the birth process.</p> <p>Methods</p> <p>Women were invited to participate in the study by independent midwives and obstetricians during antenatal visits in 2004-2005. Two questionnaires were filled out by 611 women, one at 30 weeks of pregnancy and one within the first 2 weeks after childbirth either at home or in a hospital. However, only women having a hospital birth without obstetric intervention (N = 327) were included in this analysis. A logistic regression analysis has been performed.</p> <p>Results</p> <p>Labour pain acceptance and personal control in pain relief render pain medication use during labour less likely, especially if they occur together. Apart from this general result, we also find large country differences. Dutch women with a normal hospital birth are six times less likely to use pain medication during labour, compared to their Belgian counterparts. This country difference cannot be explained by labour pain acceptance, since - in contrast to our working hypothesis - Dutch and Belgian women giving birth in a hospital setting are characterised by a similar labour pain acceptance. Our findings suggest that personal control in pain relief can partially explain the country differences in coping with labour pain. For Dutch women we find that the use of pain medication is lowest if women experience control over the reception of pain medication and have a positive attitude towards labour pain. In Belgium however, not personal control over the use of pain relief predicts the use of pain medication, but negative attitudes towards labour.</p> <p>Conclusions</p> <p>Apart from individual level determinants, such as length of labour or pain acceptance, our findings suggest that the maternity care context is of major importance in the study of the management of labour pain. The pain medication use in Belgian hospital maternity care is high and is very sensitive to negative attitudes towards labour pain. In the Netherlands, on the contrary, pain medication use is already low. This can partially be explained by a low degree of personal control in pain relief, especially when co-occurring with positive pain attitudes.</p
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