423 research outputs found

    The future is now: Model-based clinical trial design for Alzheimer's disease

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    Failures in trials for Alzheimer's disease (AD) may be attributable to inadequate dosing, population selection, drug inefficacy, or insufficient design optimization. The Coalition Against Major Diseases (CAMD) was formed in 2008 to develop drug development tools (DDT) to expedite drug development for AD and Parkinson's disease.1 CAMD led a process that successfully advanced a clinical trial simulation (CTS) tool for AD through the formal regulatory review process at the US Food and Drug Administration (FDA) and European Medicines Agency (EMA)

    Infectious diseases in a Nicaraguan refugee camp in Costa Rica

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    Artículo científico -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 1989Some Nicaraguans living in Costa Rica are in refugee camps. The types and rates of infectious diseases in the Pueblo Nuevo refugee camp were measured by examining medical records for 1985 and performing stool and blood testing. The incidence of infections was 320 episodes per 1000 persons per year. Respiratory infections represented 63% of all illnesses and pulmonary tuberculosis was high. Malaria was not found in blood samples and no childhood illnesses preventable by immunizations were recorded in the records. intestinal parasites were found in 565 of the persons examined, considerably higher than the 153/4 prevalence noted in surveys of Costa Rica as a whole. Trichuris trichlura was found in 40 To of the positive stool samples. The deficient hygienic conditions and overcrowding in the camp are responsible for the high rates of infections and the continued presence of infections many of which probably were acquired in Nicaragua. Improvement of hygienic conditions can be accomplished by involving the refugees in education, cleaning and identifying problem areas. Adequate sanitation and improved water supply, and reducing overcrowding are also recommended.Universidad de Costa Rica. Instituto de Investigaciones en Salud.Columbia University College of Physicians and Surgeons. New YorkUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

    Multimodal Imaging Nanoparticles Derived from Hyaluronic Acid for Integrated Preoperative and Intraoperative Cancer Imaging

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    Surgical resection remains the most promising treatment strategy for many types of cancer. Residual malignant tissue after surgery, a consequence in part due to positive margins, contributes to high mortality and disease recurrence. In this study, multimodal contrast agents for integrated preoperative magnetic resonance imaging (MRI) and intraoperative fluorescence image-guided surgery (FIGS) are developed. Self-assembled multimodal imaging nanoparticles (SAMINs) were developed as a mixed micelle formulation using amphiphilic HA polymers functionalized with either GdDTPA for T1 contrast-enhanced MRI or Cy7.5, a near infrared fluorophore. To evaluate the relationship between MR and fluorescence signal from SAMINs, we employed simulated surgical phantoms that are routinely used to evaluate the depth at which near infrared (NIR) imaging agents can be detected by FIGS. Finally, imaging agent efficacy was evaluated in a human breast tumor xenograft model in nude mice, which demonstrated contrast in both fluorescence and magnetic resonance imaging

    Discriminative capacity and construct validity of the Clock Drawing Test in Mild Cognitive Impairment and Alzheimer's disease

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    OBJECTIVES: The aim of this study was to analyze the psychometric and diagnostic properties of the Clock Drawing Test (CDT), scored according to the Babins, Rouleau, and Cahn scoring systems, for Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) screening, and develop corresponding cutoff scores. Additionally, we assessed the construct validity of the CDT through exploratory and confirmatory factor analysis. METHODS: We developed a cross-sectional study of ambulatory MCI and AD patients, divided in two clinical groups (450 MCI and 250 mild AD patients) and a normal control group (N = 400). All participants were assessed with the CDT, Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) for convergent validity. RESULTS: The selected scoring systems presented adequate validity and reliability values. The proposed cutoff scores showed 60 to 65% sensitivity and 58 to 62% specificity to identify MCI patients. The corresponding values for AD were 84 to 90% sensitivity and 76 to 78% specificity. Exploratory and confirmatory factor analysis revealed that the Babins scoring system had good construct validity and allowed us to propose a three-factor model for this system. CONCLUSIONS: Our results confirmed the complexity of the CDT and support it as a cognitive screening instrument particularly sensitive to AD. The use of the CDT with MCI patients should be interpreted with more caution due to the lower sensitivity and specificity for milder forms of cognitive impairment.info:eu-repo/semantics/publishedVersio

    Dermatofibrosarcoma presenting as a nodule in the breast of a 75-year-old woman: a case report

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    ABSTRACT: INTRODUCTION: Dermatofibrosarcoma protuberans is a rare neoplasm of soft tissues and its location in the breast is extremely uncommon. Confusion is possible with other primary breast lesions. CASE PRESENTATION: A 75-year-old Caucasian woman presented with a mass in her left breast 21 years after being diagnosed with invasive ductal carcinoma of the right breast, treated by a right mastectomy and axillary dissection followed by radiotherapy and breast reconstruction. Mammography revealed a dish-shaped skin nodule formation in the upper outer quadrant of her left breast. Echography confirmed the presence of a lesion measuring 1.4 x 0.8 cm. Based on imaging, the diagnosis was a probable angiosarcoma. Due to the presence of a pacemaker for cardiac arrhythmia and full anticoagulation therapy for a pulmonary embolism, magnetic resonance imaging and a biopsy were not done. We proceeded directly to a quadrantectomy and the final diagnosis revealed a dermatofibrosarcoma protuberans, 1. 8 cm in its greatest microscopic dimension, located 0.1 cm from the upper surgical margin. To ensure the wide resection margins required for this type of neoplasm, a re-excision was performed. CONCLUSION: A dermatofibrosarcoma protuberans of the breast is an uncommon discovery. The aim of this case report is to highlight the importance of the surgical procedure in cases of the discovery of dermatofibrosarcoma protuberans. Re-excision may be necessary to ensure adequate resection margins

    Notch signaling during human T cell development

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    Notch signaling is critical during multiple stages of T cell development in both mouse and human. Evidence has emerged in recent years that this pathway might regulate T-lineage differentiation differently between both species. Here, we review our current understanding of how Notch signaling is activated and used during human T cell development. First, we set the stage by describing the developmental steps that make up human T cell development before describing the expression profiles of Notch receptors, ligands, and target genes during this process. To delineate stage-specific roles for Notch signaling during human T cell development, we subsequently try to interpret the functional Notch studies that have been performed in light of these expression profiles and compare this to its suggested role in the mouse

    The Beta-decay Paul Trap Mk IV: Design and commissioning

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    The Beta-decay Paul Trap is an open-geometry, linear trap used to measure the decays of 8^8Li and 8^8B to search for a tensor contribution to the weak interaction. In the latest 8^8Li measurement of Burkey et al. (2022), β\beta scattering was the dominant experimental systematic uncertainty. The Beta-decay Paul Trap Mk IV reduces the prevalence of β\beta scattering by a factor of 4 through a redesigned electrode geometry and the use of glassy carbon and graphite as electrode materials. The trap has been constructed and successfully commissioned with 8^8Li in a new data campaign that collected 2.6 million triple coincidence events, an increase in statistics by 30% with 4 times less β\beta scattering compared to the previous 8^8Li data set.Comment: 17 pages, 7 figure
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