1,355 research outputs found
Protecting eyewitness evidence: Examining the efficacy of a self-administered interview tool
Given the crucial role of eyewitness evidence, statements should be obtained as soon as possible after an incident. This is not always achieved due to demands on police resources. Two studies trace the development of a new tool, the Self-Administered Interview (SAI), designed to elicit a comprehensive initial statement. In Study 1, SAI participants reported more correct details than participants who provided a free recall account, and performed at the same level as participants given a Cognitive Interview. In Study 2, participants viewed a simulated crime and half recorded their statement using the SAI. After a delay of 1 week, all participants completed a free recall test. SAI participants recalled more correct details in the delayed recall task than control participants
Simple geometry tribological study of osteochondral graft implantation in the knee
Robust preclinical test methods involving tribological simulations are required to investigate and understand the tribological function of osteochondral repair interventions in natural knee tissues. The aim of this study was to investigate the effects of osteochondral allograft implantation on the local tribology (friction, surface damage, wear and deformation) of the tissues in the natural knee joint using a simple geometry, reciprocating pin-on-plate friction simulator. In addition, the study aimed to assess the ability of osteochondral grafts to restore a low surface damage, deformation and wear articulation when compared to the native state. A method was developed to characterise and quantify surface damage wear and deformation of the opposing cartilage-bone pin surface using a non-contacting optical profiler (Alicona Infinite Focus). Porcine 12 mm diameter cartilage-bone pins were reciprocated against bovine cartilage-bone plates with 6 mm diameter osteochondral allografts, cartilage defects or stainless steel pins (positive controls) inserted centrally. Increased levels of surface damage with changes in geometry were not associated with significant increases in the coefficient of dynamic friction. Significant damage to the opposing cartilage surface was observed in the positive control groups. Cartilage damage, deformation and wear (as measured by change in geometry) in the xenograft (2.4 mmΒ³) and cartilage defect (0.99 mmΒ³) groups was low and not significantly different (p>0.05) compared to the negative control in either group. The study demonstrated the potential of osteochondral grafts to restore the congruent articular surface and biphasic tribology of the natural joint. An optical method has been developed to characterise cartilage wear, damage and deformation, that can be applied to the tribological assessment of osteochondral grafts in a whole natural knee joint simulation model
Asymmetric triplex metallohelices with high and selective activity against cancer cells
Small cationic amphiphilic Ξ±-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail βtriplexβ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and βp53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 βp53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli.
At a glanc
Spontaneous Eosinophilic Nasal Inflammation in a Genetically-Mutant Mouse: Comparative Study with an Allergic Inflammation Model
Background: Eosinophilic inflammation is a hallmark of chronic rhinosinusitis with nasal polyps. To model this disease process experimentally, nasal sensitization of mice with ovalbumin or aspergillus has been described. Here, we describe a genetically mutant mouse that develops robust spontaneous nasal eosinophilic inflammation. These mice lack the enzyme SHP-1 that down-regulates the IL-4Ra/stat6 signaling pathway. We compared nasal inflammation and inflammatory mediators in SHP-1 deficient mice (mev) and an ovalbumin-induced nasal allergy model. Methods: A novel technique of trans-pharyngeal nasal lavage was developed to obtain samples of inflammatory cells from the nasal passages of allergic and mev mice. Total and differential cell counts were performed on cytospin preparations. Expression of tissue mRNA for IL-4, IL-13, and mouse beta-defensin-1 (MBD-1) was determined by quantitative PCR. Eotaxin in the lavage fluid was assessed by ELISA. Results: Allergic and mev mice had increased total cells and eosinophils compared with controls. Expression of IL-4 was similarly increased in both allergic and mev mice, but expression of IL-13 and eotaxin was significantly greater in the allergic mice than mev mice. Eotaxin was significantly up-regulated in both allergic rhinitis and mev mice. In both models of eosinophilic inflammation, down-regulation of the innate immune marker MBD-1 was observed. Conclusions: The mev mice display spontaneous chronic nasal eosinophilic inflammation with potential utility for chroni
Histone deacetylases as new therapy targets for platinum-resistant epithelial ovarian cancer
Introduction: In developed countries, ovarian cancer is the fourth most common cancer in women. Due to the nonspecific symptomatology associated with the disease many patients with ovarian cancer are diagnosed late, which leads to significantly poorer prognosis. Apart from surgery and radiotherapy, a substantial number of ovarian cancer patients will undergo chemotherapy and platinum based agents are the mainstream first-line therapy for this disease. Despite the initial efficacy of these therapies, many women relapse; therefore, strategies for second-line therapies are required. Regulation of DNA transcription is crucial for tumour progression, metastasis and chemoresistance which offers potential for novel drug targets. Methods: We have reviewed the existing literature on the role of histone deacetylases, nuclear enzymes regulating gene transcription. Results and conclusion: Analysis of available data suggests that a signifant proportion of drug resistance stems from abberant gene expression, therefore HDAC inhibitors are amongst the most promising therapeutic targets for cancer treatment. Together with genetic testing, they may have a potential to serve as base for patient-adapted therapies
Rectal Transmission of Transmitted/Founder HIV-1 Is Efficiently Prevented by Topical 1% Tenofovir in BLT Humanized Mice
Rectal microbicides are being developed to prevent new HIV infections in both men and women. We focused our in vivo preclinical efficacy study on rectally-applied tenofovir. BLT humanized mice (nβ=β43) were rectally inoculated with either the primary isolate HIV-1(JRCSF) or the MSM-derived transmitted/founder (T/F) virus HIV-1(THRO) within 30 minutes following treatment with topical 1% tenofovir or vehicle. Under our experimental conditions, in the absence of drug treatment we observed 50% and 60% rectal transmission by HIV-1(JRCSF) and HIV-1(THRO), respectively. Topical tenofovir reduced rectal transmission to 8% (1/12; log rank pβ=β0.03) for HIV-1(JRCSF) and 0% (0/6; log rank pβ=β0.02) for HIV-1(THRO). This is the first demonstration that any human T/F HIV-1 rectally infects humanized mice and that transmission of the T/F virus can be efficiently blocked by rectally applied 1% tenofovir. These results obtained in BLT mice, along with recent ex vivo, Phase 1 trial and non-human primate reports, provide a critically important step forward in the development of tenofovir-based rectal microbicides
Of cattle, sand flies and men : a systematic review of risk factor analyses for South Asian visceral leishmaniasis and implications for elimination
Background: Studies performed over the past decade have identified fairly consistent epidemiological patterns of risk
factors for visceral leishmaniasis (VL) in the Indian subcontinent.
Methods and Principal Findings: To inform the current regional VL elimination effort and identify key gaps in knowledge,
we performed a systematic review of the literature, with a special emphasis on data regarding the role of cattle because
primary risk factor studies have yielded apparently contradictory results. Because humans form the sole infection reservoir,
clustering of kala-azar cases is a prominent epidemiological feature, both at the household level and on a larger scale.
Subclinical infection also tends to show clustering around kala-azar cases. Within villages, areas become saturated over a
period of several years; kala-azar incidence then decreases while neighboring areas see increases. More recently, post kalaazar
dermal leishmaniasis (PKDL) cases have followed kala-azar peaks. Mud walls, palpable dampness in houses, and peridomestic
vegetation may increase infection risk through enhanced density and prolonged survival of the sand fly vector.
Bed net use, sleeping on a cot and indoor residual spraying are generally associated with decreased risk. Poor micronutrient
status increases the risk of progression to kala-azar. The presence of cattle is associated with increased risk in some studies
and decreased risk in others, reflecting the complexity of the effect of bovines on sand fly abundance, aggregation, feeding
behavior and leishmanial infection rates. Poverty is an overarching theme, interacting with individual risk factors on multiple
levels.
Conclusions: Carefully designed demonstration projects, taking into account the complex web of interconnected risk
factors, are needed to provide direct proof of principle for elimination and to identify the most effective maintenance
activities to prevent a rapid resurgence when interventions are scaled back. More effective, short-course treatment
regimens for PKDL are urgently needed to enable the elimination initiative to succeed
Vitamin D and Systemic Lupus Erythematosus: Bones, Muscles, and Joints
Vitamin D3, or cholecalciferol, is the naturally occurring form of vitamin D that is converted in the skin and hydroxylated in the liver and kidney to the active form found in humans. The main role for vitamin D is calcium homeostasis, and low levels of vitamin D result in lower gastrointestinal absorption of calcium. Vitamin D is also critical for mineralization of bone tissue, muscle function, and coordination. Recent studies have found prevention of bone mass loss and reduction in falls and fractures in patients supplemented with vitamin D. A high percentage of systemic lupus erythematosus patients are reported to have insufficient or deficient levels of vitamin D. This paper reviews the biology of vitamin D, its role in calcium homeostasis, and how it contributes to the maintenance of bone, muscle, and joint function in older adults and individuals with systemic lupus erythematosus
Comparison between clinical grading and navigation data of knee laxity in ACL-deficient knees
<p>Abstract</p> <p>Background</p> <p>The latest version of the navigation system for anterior cruciate ligament (ACL) reconstruction has the supplementary ability to assess knee stability before and after ACL reconstruction. In this study, we compared navigation data between clinical grades in ACL-deficient knees and also analyzed correlation between clinical grading and navigation data.</p> <p>Methods</p> <p>150 ACL deficient knees that received primary ACL reconstruction using an image-free navigation system were included. For clinical evaluation, the Lachman, anterior drawer, and pivot shift tests were performed under general anesthesia and were graded by an examiner. For the assessment of knee stability using the navigation system, manual tests were performed again before ACL reconstruction. Navigation data were recorded as anteroposterior (AP) displacement of the tibia for the Lachman and anterior drawer tests, and both AP displacement and tibial rotation for the pivot shift test.</p> <p>Results</p> <p>Navigation data of each clinical grade were as follows; Lachman test grade 1+: 10.0 mm, grade 2+: 13.2 Β± 3.1 mm, grade 3+: 14.5 Β± 3.3 mm, anterior drawer test grade 1+: 6.8 Β± 1.4 mm, grade 2+: 7.4 Β± 1.8 mm, grade 3+: 9.1 Β± 2.3 mm, pivot shift test grade 1+: 3.9 Β± 1.8 mm/21.5Β° Β± 7.8Β°, grade 2+: 4.8 Β± 2.1 mm/21.8Β° Β± 7.1Β°, and grade 3+: 6.0 Β± 3.2 mm/21.1Β° Β± 7.1Β°. There were positive correlations between clinical grading and AP displacement in the Lachman, and anterior drawer tests. Although positive correlations between clinical grading and AP displacement in pivot shift test were found, there were no correlations between clinical grading and tibial rotation in pivot shift test.</p> <p>Conclusions</p> <p>In response to AP force, the navigation system can provide the surgeon with correct objective data for knee laxity in ACL deficient knees. During the pivot shift test, physicians may grade according to the displacement of the tibia, rather than rotation.</p
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