437 research outputs found
How accurate is an LCD screen version of the Pelli–Robson test?
Purpose: To evaluate the accuracy and repeatability of a computer-generated Pelli–Robson test displayed on liquid crystal display (LCD) systems compared to a standard Pelli–Robson chart. Methods: Two different randomized crossover experiments were carried out for two different LCD systems for 32 subjects: 6 females and 10 males (40.5 ± 13.0 years) and 9 females and 7 males (27.8 ± 12.2 years), respectively, in the first and second experiment. Two repeated measurements were taken with the printed Pelli–Robson test and with the LCDs at 1 and 3 m. To test LCD reliability, measurements were repeated after 1 week. Results: In Experiment 1, contrast sensitivity (CS) measured with LCD1 resulted significantly higher than Pelli–Robson both at 1 and at 3 m of about 0.20 log 1/C in both eyes (p < 0.01). Bland–Altman plots showed a proportional bias for LCD1 measures. LCD1 measurements showed reasonable repeatability: ICC was 0.83 and 0.65 at 1 and 3 m, respectively. In Experiment 2, CS measured with LCD2 resulted significantly lower than Pelli–Robson both at 1 and at 3 m of about 0.10 log 1/C in both eyes (p < 0.01). Bland–Altman plots did not show any proportional bias for LCD2 measures. LCD2 measurements showed sufficient repeatability: ICC resulted 0.51 and 0.65 at 1 and 3 m, respectively. Conclusions: Computer-generated versions of Pelli–Robson test, displayed on LCD systems, do not provide accurate results compared to classic Pelli–Robson printed version. Clinicians should consider that Pelli–Robson computer-generated versions could be non-interchangeable to the printed version
Feasibility of preoperative planning using anatomical facsimile models for mandibular reconstruction
BACKGROUND: Functional and aesthetic mandibular reconstruction after ablative tumor surgery continues to be a challenge even after the introduction of microvascular bone transfer. Complex microvascular reconstruction of the resection site requires accurate preoperative planning. In the recent past, bone graft and fixation plates had to be reshaped during the operation by trial and error, often a time-consuming procedure. This paper outlines the possibilities and advantages of the clinical application of anatomical facsimile models in the preoperative planning of complex mandibular reconstructions after tumor resections. METHODS: From 2003 to 2005, in the Department of Maxillofacial Surgery of the University of Udine, a protocol was applied with the preoperative realization of stereolithographic models for all the patients who underwent mandibular reconstruction with microvascular flaps. 24 stereolithographic models were realized prior to surgery before emimandibulectomy or segmental mandibulectomy. The titanium plates to be used for fixation were chosen and bent on the model preoperatively. The geometrical information of the virtual mandibular resections and of the stereolithographic models were used to choose the ideal flap and to contour the flap into an ideal neomandible when it was still pedicled before harvesting. RESULTS: Good functional and aesthetic results were achieved. The surgical time was decreased on average by about 1.5 hours compared to the same surgical kind of procedures performed, in the same institution by the same surgical team, without the aforesaid protocol of planning. CONCLUSION: Producing virtual and stereolithographic models, and using them for preoperative planning substantially reduces operative time and difficulty of the operation during microvascular reconstruction of the mandible
A human, compact, fully functional anti-ErbB2 antibody as a novel antitumour agent
A new human, compact antibody was engineered by fusion of a human, antitumour ErbB2-directed scFv with a human IgG1 Fc domain. Overexpression of the ErbB2 receptor is related to tumour aggressiveness and poor prognosis. This new immunoagent meets all criteria for a potential anticancer drug: it is human, hence poorly or not immunogenic; it binds selectively and with high affinity to target cells, on which it exerts an effective and selective antiproliferative action, including both antibody-dependent and complement-dependent cytotoxicity; it effectively inhibits tumour growth in vivo. Its compact molecular size should provide for an efficient tissue penetration, yet suitable to a prolonged serum half-life
The action of a multidisciplinary team in the nutritional care of critically ill patients
Hospitalized patients may have special nutrient requirements imposed by a combination of malnutrition and enhanced utilization of nutrients resulting from the disease process. Nutritional support, mainly during critical stages of disease, should be provided safely and effectively. Several studies have evaluated the paper of a multidisciplinary team in the administration of a nutritional therapy. Individually, the majority of these studies are underpowered to evaluate an effect on the quality of nutritional care. With the objective to identify problems inherent to the supply of nutritional support to hospitalized patients and verify the impact of the actions of a multidisciplinary team on the quality of these procedures, we analysed articles that have been published between 1980 and 2004 about the role of the action of multidisciplinary teams in the care and nutritional outcome of hospitalized patients, especially those undergoing intensive care. The terms used for the search were: multidisciplinary team, nutritional support, parenteral nutrition, enteral feeding, critically ill, intensive care unit, critically ill child. Of 130 studies, intially identified, just 24 were selected, of which 14 compared the standard of nutritional therapy with and without the presence of a multidisciplinary team. The inadequate supply of nutrients, infection and metabolic complications and the excessive use of parenteral nutrition were the main problems detected in the supply of nutritional support to hospitalized patients. In the comparative studies, the presence of the multidisciplinary team improved the pattern of nutritional support, and reduced the incidence of complications and the costs.Pacientes hospitalizados podem ter necessidades nutricionais especiais em função da desnutrição e dos desequilÃbrios metabólicos impostos pelas doenças. A terapia nutricional, principalmente nos estágios crÃticos das enfermidades, deve ser administrada de modo seguro e eficaz. Vários estudos têm avaliado o papel da equipe multidisciplinar na administração da terapia nutricional. Com o objetivo de identificar os problemas inerentes à administração da terapia nutricional em pacientes hospitalizados e verificar o impacto da atuação de uma equipe multidisciplinar na qualidade dos procedimentos, foi realizada uma revisão que analisou artigos publicados entre 1980 e 2004 sobre o papel da atuação de equipes multidisciplinares no cuidado e na evolução nutricional de pacientes hospitalizados, principalmente os que se encontravam sob cuidados intensivos. Os termos utilizados na pesquisa foram: multidisciplinary team, nutritional support, parente-ral nutrition, enteral feeding, critically ill, intensive care unit,critically ill child. Dos 130 estudos inicialmente identificados, foram selecionados 24, dos quais 14 compararam o padrão de terapia nutricional com e sem a presença da equipe multidisciplinar. Os principais problemas detectados na administração de terapia nutricional em pacientes hospitalizados foram a oferta inadequada de nutrientes, as complicações infecciosas e metabólicas e o uso excessivo de nutrição parenteral. Nos estudos comparativos, a presença da equipe multidisciplinar melhorou o padrão de oferta nutricional, reduziu a incidência de complicações e os custos.Universidade Federal de São Paulo (UNIFESP) Departamento de PediatriaHospital São Paulo Unidade de Cuidados Intensivos PediátricosHospital São Paulo Equipe Multidisciplinar de Terapia NutricionalUNIFESP, Depto. de PediatriaHospital São Paulo Unidade de Cuidados Intensivos PediátricosHospital São Paulo Equipe Multidisciplinar de Terapia NutricionalSciEL
Targeting HSP90 for cancer therapy
Heat-shock proteins (HSPs) are molecular chaperones that regulate protein folding to ensure correct conformation and translocation and to avoid protein aggregation. Heat-shock proteins are increased in many solid tumours and haematological malignancies. Many oncogenic proteins responsible for the transformation of cells to cancerous forms are client proteins of HSP90. Targeting HSP90 with chemical inhibitors would degrade these oncogenic proteins, and thus serve as useful anticancer agents. This review provides an overview of the HSP chaperone machinery and the structure and function of HSP90. We also highlight the key oncogenic proteins that are regulated by HSP90 and describe how inhibition of HSP90 could alter the activity of multiple signalling proteins, receptors and transcriptional factors implicated in carcinogenesis
Increased Litterfall in Tropical Forests Boosts the Transfer of Soil CO2 to the Atmosphere
Aboveground litter production in forests is likely to increase as a consequence of elevated atmospheric carbon dioxide (CO2) concentrations, rising temperatures, and shifting rainfall patterns. As litterfall represents a major flux of carbon from vegetation to soil, changes in litter inputs are likely to have wide-reaching consequences for soil carbon dynamics. Such disturbances to the carbon balance may be particularly important in the tropics because tropical forests store almost 30% of the global soil carbon, making them a critical component of the global carbon cycle; nevertheless, the effects of increasing aboveground litter production on belowground carbon dynamics are poorly understood. We used long-term, large-scale monthly litter removal and addition treatments in a lowland tropical forest to assess the consequences of increased litterfall on belowground CO2 production. Over the second to the fifth year of treatments, litter addition increased soil respiration more than litter removal decreased it; soil respiration was on average 20% lower in the litter removal and 43% higher in the litter addition treatment compared to the controls but litter addition did not change microbial biomass. We predicted a 9% increase in soil respiration in the litter addition plots, based on the 20% decrease in the litter removal plots and an 11% reduction due to lower fine root biomass in the litter addition plots. The 43% measured increase in soil respiration was therefore 34% higher than predicted and it is possible that this ‘extra’ CO2 was a result of priming effects, i.e. stimulation of the decomposition of older soil organic matter by the addition of fresh organic matter. Our results show that increases in aboveground litter production as a result of global change have the potential to cause considerable losses of soil carbon to the atmosphere in tropical forests
Multi-Way Multi-Group Segregation and Diversity Indices
Background: How can we compute a segregation or diversity index from a three-way or multi-way contingency table, where each variable can take on an arbitrary finite number of values and where the index takes values between zero and one? Previous methods only exist for two-way contingency tables or dichotomous variables. A prototypical three-way case is the segregation index of a set of industries or departments given multiple explanatory variables of both sex and race. This can be further extended to other variables, such as disability, number of years of education, and former military service. Methodology/Principal Findings: We extend existing segregation indices based on Euclidean distance (square of coefficient of variation) and Boltzmann/Shannon/Theil index from two-way to multi-way contingency tables by including multiple summations. We provide several biological applications, such as indices for age polyethism and linkage disequilibrium. We also provide a new heuristic conceptualization of entropy-based indices. Higher order association measures are often independent of lower order ones, hence an overall segregation or diversity index should be the arithmetic mean of the normalized association measures at all orders. These methods are applicable when individuals selfidentify as multiple races or even multiple sexes and when individuals work part-time in multiple industries. Conclusions/Significance: The policy implications of this work are enormous, allowing people to rigorously test whethe
Adherence to Chronic Hepatitis B Treatment Guideline Recommendations for Laboratory Monitoring of Patients Who Are Not Receiving Antiviral Treatment
Decreased Hsp90 expression in infiltrative lobular carcinoma: an immunohistochemical study
Background: Elevated Hsp90 expression has been documented in breast ductal carcinomas, whereas decreased Hsp90 expression has been reported in precursor lobular lesions. This study aims to assess Hsp90 expression in infiltrative lobular carcinomas of the breast. Methods: Tissue specimens were taken from 32 patients with infiltrative lobular carcinoma. Immunohistochemical assessment of Hsp90 was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. Concerning Hsp90 assessment: i) the percentage of positive cells and ii) the intensity were separately analyzed. Subsequently, the Allred score was adopted and calculated. The intensity was treated as a
Stabilisation of the Fc Fragment of Human IgG1 by Engineered Intradomain Disulfide Bonds
We report the stabilization of the human IgG1 Fc fragment by engineered intradomain disulfide bonds. One of these bonds, which connects the N-terminus of the CH3 domain with the F-strand, led to an increase of the melting temperature of this domain by 10°C as compared to the CH3 domain in the context of the wild-type Fc region. Another engineered disulfide bond, which connects the BC loop of the CH3 domain with the D-strand, resulted in an increase of Tm of 5°C. Combined in one molecule, both intradomain disulfide bonds led to an increase of the Tm of about 15°C. All of these mutations had no impact on the thermal stability of the CH2 domain. Importantly, the binding of neonatal Fc receptor was also not influenced by the mutations. Overall, the stabilized CH3 domains described in this report provide an excellent basic scaffold for the engineering of Fc fragments for antigen-binding or other desired additional or improved properties. Additionally, we have introduced the intradomain disulfide bonds into an IgG Fc fragment engineered in C-terminal loops of the CH3 domain for binding to Her2/neu, and observed an increase of the Tm of the CH3 domain for 7.5°C for CysP4, 15.5°C for CysP2 and 19°C for the CysP2 and CysP4 disulfide bonds combined in one molecule
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