266 research outputs found

    Bone preserving level of osteotomy in short-stem total hip arthroplasty does not influence stress shielding dimensions – a comparing finite elements analysis

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    Background The main objective of every new development in total hip arthroplasty (THA) is the longest possible survival of the implant. Periprosthetic stress shielding is a scientifically proven phenomenon which leads to inadvertent bone loss. So far, many studies have analysed whether implanting different hip stem prostheses result in significant preservation of bone stock. The aim of this preclinical study was to investigate design- depended differences of the stress shielding effect after implantation of a selection of short-stem THA-prostheses that are currently available. Methods Based on computerised tomography (CT), a finite elements (FE) model was generated and a virtual THA was performed with different stem designs of the implant. Stems were chosen by osteotomy level at the femoral neck (collum, partial collum, trochanter sparing, trochanter harming). Analyses were performed with previously validated FE models to identify changes in the strain energy density (SED). Results In the trochanteric region, only the collum-type stem demonstrated a biomechanical behaviour similar to the native femur. In contrast, no difference in biomechanical behaviour was found between partial collum, trochanter harming and trochanter sparing models. All of the short stem-prostheses showed lower stress-shielding than a standard stem. Conclusion Based on the results of this study, we cannot confirm that the design of current short stem THA-implants leads to a different stress shielding effect with regard to the level of osteotomy. Somehow unexpected, we found a bone stock protection in metadiaphyseal bone by simulating a more distal approach for osteotomy. Further clinical and biomechanical research including long-term results is needed to understand the influence of short- stem THA on bone remodelling and to find the optimal stem-design for a reduction of the stress shielding effect

    Clinical Usefulness of Cervicogram as a Primary Screening Test for Cervical Neoplasia

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    The purpose of this study is to evaluate the clinical usefulness of the cervicogram as a primary screening test for cervical neoplasia. A total of 294 women who had undergone a cervicogram and a Pap test between January and July 2003, were selected. The diagnostic accuracy of the Pap test, cervicogram, and the Pap test combined with a cervicogram were compared with the histopathologic diagnosis. Among 294 women, the Pap test was negative in 130 cases and positive in 164 cases. Among patients with positive Pap test, cervicogram were negative in 101 cases (61.6%) and positive in 63 cases (38.4%). The diagnostic accuracy between cervicogram with positive Pap test and histology was as follows; sensitivity 44.9%, specificity 78.3%, positive predictive value 84.1%, negative predictive value 32.7%, false positive rate 15.9%, and false negative rate 67.3%. Although the adjunctive use of cervicogram with the Pap test in the initial screening of cervical neoplasia showed a higher specificity and higher positive predictive value compared to the Pap test alone, consideration in terms of lower sensitivity, lower positive predictive value, higher false positive rate and cost-effectiveness should be given in lieu of clinically applying cervicogram with the pap test as an initial screening test

    Insect repellent and chemical agronomic treatments to reduce seed numberin'Afourer'mandarin. Effect on yield and fruit diameter

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    Obtaining citrus fruits without seeds is a recurrent objective for farmers as it is one of the most valued char-acteristics, especially in mandarins.'Afourer'tangor is a highly valuable well-established mandarin, and a highpercentage of seeded fruits are produced under cross-pollination conditions. Several agronomic techniques havebeen suggested to control presence of seeds, such as covering with nets and copper sulfate (CuSO4) and gib-berellic acid (GA3) treatments. Natural bee repellents are also proposed to reduce the number of seeds per fruit.In this study, we aimed to compare the effect of several agronomic treatments to reduce the seed number in'Afourer' mandarin. To this end, we assessed the effect of chemical and bee repellent treatments on the seednumber per fruit and the side effect on yield and fruit diameter. Under these experimental conditions the two beerepellents, one based on zinc and one based onCapsicum annuum, were not useful for reducing the seed numberper fruit in'Afourer'mandarin. The copper sulfate + GA3treatment reduced the seed number per fruit by only35%, and this efficiency was clearly not enough to reduce the seed number for commercial purposes. The mosteffective method to reduce the seed number per fruit was covering with nets, but this technique led to markedlyreduced yields. Yield data was highly variable. Fruit diameter correlated positively with the seed number, but itwas a weak relationship as the seed number explained only 15% of fruit size variability (R2= 0,15)

    Evidence-Based Management of Hand Eczema

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    Hand eczema is a common skin disease with a wide variation in morphology and a complex etiology based on endogenous and exogenous factors.The diagnosis of hand eczema is based on patient history, exposure assessment, physical examination, and the results of patch testing. Management of hand eczema starts with education of the patient on the etiology of the disease, and the needed changes in behavior regarding skin care and preventive measures, and avoidance of relevant exposure factors. In many cases, medical treatment is needed for successful management of the disease; use of medication can only be successful with proper education and avoidance of relevant exposure

    Paper Spray Ionization Mass Spectrometry as a Potential Tool for Early Diagnosis of Cervical Cancer

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    Squamous intraepithelial lesion is an abnormal growth of epithelial cells on the surface of the cervix that may lead to cervical cancer. Analytical protocols for the determination of squamous intraepithelial lesions are in high demand, since cervical cancer is the fourth most diagnosed cancer among women in the world. Here, paper spray ionization mass spectrometry (PSI-MS) is used to distinguish between healthy (negative for intraepithelial lesion or malignancy) and diseased (high-grade squamous intraepithelial lesion) blood plasmas. A total of 86 blood samples of different women (49 healthy samples, 37 diseased samples) were collected, and the plasmas were prepared. Then, 10 μL of each plasma sample was deposited onto triangular papers for PSI-MS analysis. No additional step of sample preparation was necessary. The interval-successive projection algorithm linear discriminant analysis (iSPA-LDA) was applied to the PSI mass spectra, showing six ions (mostly phospholipids) that were predictive of healthy and diseased plasmas. Values of 77% accuracy, 86% sensitivity, 80% positive predictive value (PPV), and 75% negative predictive value (NPV) were achieved. This study provides evidence that PSI-MS may potentially be used as a fast and simple analytical technique for the early diagnosis of cervical cancer

    Pollen Competition as a Reproductive Isolation Barrier Represses Transgene Flow between Compatible and Co-Flowering Citrus Genotypes

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    Background/Objective: Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. Methodology/Principal Findings: Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17-2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. Conclusions/Significance: Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species. (Résumé d'auteur

    Can we identify patients at risk of life-threatening allergic reactions to food?

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    Anaphylaxis has been defined as a “severe, life-threatening generalized or systemic hypersensitivity reaction”. However, data indicate that the vast majority of food-triggered anaphylactic reactions are not life-threatening. Nonetheless, severe life-threatening reactions do occur, and are unpredictable. We discuss the concepts surrounding perceptions of severe, life-threatening allergic reactions to food by different stakeholders, with particular reference to the inclusion of clinical severity as a factor in allergy and allergen risk management. We review the evidence regarding factors which might be used to identify those at most risk of severe allergic reactions to food, and the consequences of misinformation in this regard. For example, a significant proportion of food-allergic children also have asthma, yet almost none will experience a fatal food-allergic reaction; asthma is not, in itself, a strong predictor for fatal anaphylaxis. The relationship between dose of allergen exposure and symptom severity is unclear. While dose appears to be a risk factor in at least a subgroup of patients, studies report that individuals with prior anaphylaxis do not have a lower eliciting dose than those reporting previous mild reactions. It is therefore important to consider severity and sensitivity as separate factors, as a highly sensitive individual will not necessarily experience severe symptoms during an allergic reaction. We identify the knowledge gaps which need to be addressed to improve our ability to better identify those most at risk of severe foodinduced allergic reactions
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