Publications by authors named "Natalie Landman"

Background The factors influencing medical student clinical specialty choice have important implications for the future composition of the US physician workforce. The objective of this study was to determine the career net present values (NPVs) of US medical students' clinical specialty choices and identify any relationships between a specialty's NPV and competitiveness of admissions as measured by the US Medical Licensing Examination (USMLE) Step 1 scores. Methodology NPVs were calculated using the results of the 2019 Doximity Physician Compensation report, a survey of 90,000 physicians.

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Objective: To describe the variation in asthma quality and costs among children with different Medicaid insurance plans.

Methods: We used 2013 data from the Center for Health Information and Research, which houses a database that includes individuals who have Medicaid insurance in Arizona. We analyzed children ages 2-17 years-old who lived in Maricopa County, Arizona.

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Physicians must possess knowledge and skills to address the gaps facing the US health care system. Educators advocate for reform in undergraduate medical education (UME) to align competencies with the Triple Aim. In 2014, five medical schools and one state university began collaborating on these curricular gaps.

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It is becoming increasingly clear that maintaining and improving the health of the population, and doing so in a financially sustainable manner, requires the coordination of acute medical care with long-term care, and social support services, that is, team-based care. Despite a growing body of evidence on the benefits of team-based care, the health care ecosystem remains "resistant" to a broader implementation of such care models. This resistance is a function of both system-wide and organizational barriers, which result primarily from fragmentation in reimbursement for health care services, regulatory restrictions, and the siloed nature of health professional education.

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Given the complex nature of Alzheimer's disease (AD), a cell-based model that recapitulates the physiological properties of the target neuronal population would be extremely valuable for discovering improved drug candidates and chemical probes to uncover disease mechanisms. We established phenotypic neuronal assays for the biogenesis and synaptic action of amyloid β peptide (Aβ) based on embryonic stem cell-derived neurons (ESNs). ESNs enriched with pyramidal neurons were robust, scalable, and amenable to a small-molecule screening assay, overcoming the apparent limitations of neuronal models derived from human pluripotent cells.

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Amyloid β-peptide (Aβ) pathology is an invariant feature of Alzheimer disease, preceding any detectable clinical symptoms by more than a decade. To this end, we seek to identify agents that can reduce Aβ levels in the brain via novel mechanisms. We found that (20S)-Rg3, a triterpene natural compound known as ginsenoside, reduced Aβ levels in cultured primary neurons and in the brains of a mouse model of Alzheimer disease.

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Phosphatidylinositol 4,5-bisphosphate (PIP2) is an important cellular effector whose functions include the regulation of ion channels and membrane trafficking. Aberrant PIP2 metabolism has also been implicated in a variety of human disease states, e.g.

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A number of cell surface growth factor receptors are subject to presenilin-dependent regulated intramembrane proteolysis (PS-RIP) after ligand binding and/or ectodomain cleavage. PS-RIP is mediated by a highly conserved multi-component membrane-bound protease, termed gamma-secretase, responsible for generating Alzheimer's disease (AD)-associated Abeta peptide from its membrane-bound beta-amyloid precursor protein (APP), as well as for cleaving a number of other type-I membrane receptors. PS-RIP is a conserved cellular process by which cells transmit signals from one compartment to another, including the liberation of membrane-bound transcription factors.

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The generation of biologically active proteins by regulated intramembrane proteolysis is a highly conserved mechanism in cell signaling. Presenilin-dependent gamma-secretase activity is responsible for the intramembrane proteolysis of selected type I membrane proteins, including beta-amyloid precursor protein (APP) and Notch. A small fraction of intracellular domains derived from both APP and Notch translocates to and appears to function in the nucleus, suggesting a generic role for gamma-secretase cleavage in nuclear signaling.

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Previous studies have shown that n-3 polyunsaturated fatty acids (PUFAs) can exert an antiapoptotic effect on neurons. The present study was designed to investigate whether the Caenorhabditis elegans fat-1 gene encoding an n-3 fatty acid desaturase (an enzyme that converts n-6 PUFAs to corresponding n-3 PUFAs) can be expressed functionally in rat cortical neurons and whether its expression can change the ratio of n-6 : n-3 fatty acids in the cell membrane and exert an effect on neuronal apoptosis. Infection of primary rat cortical cultures with Ad-fat-1 resulted in high expression of the fat-1 gene.

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Background: Loss or mutation of the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R) has been found in breast cancer. However, whether or not decreased levels of functional M6P/IGF2R directly contribute to the process of carcinogenesis needs to be further verified by functional studies.

Methods: In this study, using viral and ribozyme strategies we reduced the expression of M6P/IGF2R in human breast cancer cells and then examined the effect on growth and apoptosis of these cells.

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