Secondary Dengue viral infection can produce capillary leakage associated with increased mortality known as Dengue Hemorrhagic Fever (DHF). Because the mortality of DHF can be reduced by early detection and intensive support, improved methods for its detection are needed. We applied multidimensional protein profiling to predict outcomes in a prospective Dengue surveillance study in South America. Plasma samples taken from initial clinical presentation of acute Dengue infection were subjected to proteomics analyses using ELISA and a recently developed biofluid analysis platform. Demographics, clinical laboratory measurements, 9 cytokines and 419 plasma proteins collected at the time of initial presentation were compared between the DF and DHF outcomes. Here, the subject’s gender, clinical parameters, 2 cytokines and 42 proteins discriminated between the outcomes. These factors were reduced by multivariate adaptive regression splines (MARS) that a highly accurate classification model based on 8 discriminant features with an AUC of 0.999. Model analysis indicated that the feature-outcome relationship were non-linear. Although this DHF risk model will need validation in a larger cohort, we conclude that approaches to develop predictive biomarker models for disease outcome will need to incorporate nonparametric modeling approaches.
The ErbB2 (Her2/neu epidermal growth receptor family) oncogene is overexpressed in 30% to 40% of human breast cancers. Cyclin D1 is the regulatory subunit of the holoenzyme that phosphorylates and inactivates the retinoblastoma (pRb) tumor suppressor and is an essential downstream target of ErbB2-induced tumor growth. Herein, we demonstrate that ErbB2 induces the activity of the Notch signaling pathway. ErbB2 induction of DNA synthesis, contact-independent growth, and mammosphere induction required Notch1. ErbB2-induced cyclin D1 and cyclin D1 expression was sufficient to induce Notch1 activity, and conversely, genetic deletion of Notch1 in mammary epithelial cells using floxed Notch (Notchfl/fl ) mice demonstrated that cyclin D1 is induced by Notch1. Genetic deletion of cyclin D1 or small interfering RNA (siRNA) to cyclin D1-reduced Notch1 activity and reintroduction of cyclin D1 into cyclin D1-deficient cells restored Notch1 activity through the inhibition of Numb, an endogenous inhibitor of Notch1 activity. Thus, cyclin D1 functions downstream as a genetic target of Notch1, amplifies Notch1 activity by repressing Numb, and identifies a novel pathway by which ErbB2 induces Notch1 activity via the induction of cyclin D1.
cancer biology; oncogenes; signal transduction
Iron homeostasis influences the development of pulmonary arterial hypertension (PAH) associated with hypoxia or hematologic disorders. To investigate whether severity of idiopathic PAH (IPAH) is impacted by alterations in iron metabolism, we assessed iron metabolic markers, including levels of Zinc-protoporphyrin (Zn-pp), transferrin receptor, and red blood cell numbers and morphology in IPAH, associated PAH (APAH) and sleep apnea induced pulmonary hypertension (PH) patients in comparison to healthy controls and asthmatics. Despite similarly normal measures of iron metabolism, Zn-pp levels in IPAH and sleep apnea patients were elevated ~2-fold, indicating deficient iron incorporation to form heme and levels were closely related to measures of disease severity. Consistent with high Zn-PP, PAH patients had increased red cell distribution width (RDW). In an expanded cohort including patients with IPAH and familial disease (FPAH) the RDW was validated and related to clinical parameters of severity, including pulmonary artery pressures and 6 minute walk distances. These results reveal an increased prevalence of subclinical functional iron deficiency in primary forms of PAH that is quantitatively related to disease severity. This suggests that altered iron homeostasis influences disease progression and demonstrates the importance of closely monitoring iron status in PAH patients.
Acute kidney injury (AKI) is a common, heterogeneous and detrimental clinical condition that has significant attributable morbidity and mortality. Despite major advances in understanding the epidemiology, pathogenesis and outcomes of AKI, preventive measures remain inadequate and therapeutic approaches (except for renal replacement therapy) have largely proven futile so far. Critical to the process of designing rational therapies is translational research, which involves the transition between the basic research discoveries and everyday clinical applications to prevent, diagnose and treat human diseases. Progress in innovative approaches has been hampered due in part to the reliance on functional markers (serum creatinine and blood urea nitrogen) that are neither sensitive nor specific to diagnose AKI. This limitation has created a great deal of interest and intense investigation to identify a “troponin-like marker” that would facilitate recognition of AKI and allow for timely implementation of the precise therapeutic agent. The other major obstacle in this field is the diverse and complex nature of AKI that involves multiple independent and overlapping pathways, making it difficult to cure AKI with a single approach. In this review, we will summarize the advances, ongoing studies and future perspectives in the field of translational research of AKI.
Autosomal recessive polycystic kidney disease (ARPKD) is a developmental disorder that mainly affects the kidneys and the biliary tract. Affected patients often have massively enlarged cystic kidneys as well as congenital hepatic fibrosis characterized by dilated bile ducts and associated peribiliary fibrosis. This review will examine what is known about ARPKD-associated liver disease and will highlight areas of ongoing research into its pathogenesis and potential treatment.
Health disparities may affect any person in any community in the world, resulting from a multitude of factors including socioeconomic status, race, ethnicity, environment, and genetics. The impact of health disparities is felt by affected individuals, their families, communities, and the greater health care system.
There is a critical need to increase health disparities research activities. This may be achieved by expanding and strengthening the training, education and career development of motivated clinicians, physicians and basic scientists, engaging them in clinical and translational research. Translational research relies on collaboration across disciplines, facilitating the dissemination and transfer of knowledge to populations for the overall improvement of health while decreasing the economic burden of health care.
The University of Puerto Rico Medical Sciences Campus (UPR-MSC), Schools of Health Professions and Medicine joint initiatives, Clinical Research Education and Career Development (CRECD) and Hispanics in Research Capability (HiREC) programs, convened health disparities experts, faculty and scholars from multiple disciplines, cultural backgrounds and institutions. Together, they created a model for teaching translational research in health disparities that spans disciplines without boundaries. This work was presented at the 2011 Clinical and Translational Research and Education Meeting, ACRT/AFMR/SCTS Joint Annual Meeting in Washington, DC.
Research training has enabled academic clinicians to contribute significantly to the body of medical research literature. Biostatistics represents a critical methodological skill for such researchers, as statistical methods are increasingly a necessary part of medical research. However, there is no validated knowledge and skills assessment for graduate level biostatistics for academic medical researchers. In this paper I review graduate level statistical competencies and existing instruments intended to assess physicians’ ability to read the medical literature and for undergraduate statistics for their alignment with core competencies necessary for successful use of statistics. This analysis shows a need for a new instrument to assess biostatistical competencies for medical researchers.
core competency; biostatistics; knowledge and skills assessment
Translational Science Search (http://tscience.nlm.nih.gov) is a Web application for finding MEDLINE/PubMed journal articles that are regarded by their authors as novel, promising, or may have potential clinical application. A set of “translational” filters and related terms was created by reviewing journal articles published in clinical and translational science journals. Through E-Utilities, a user’s query and translational science (TS) filters are submitted to PubMed, and then the retrieved PubMed citations are matched with a database of MeSH terms (for disease conditions) and RxNorm (for interventions) to locate the search term, translational filters found, and associated interventions in the title and abstract. An algorithm ranks the Interventions and Conditions, and then highlights them in the results page for quick reading and evaluation. Using previously searched terms and standard formulas, the Precision and Recall of Translational Science Search (TSS) were 0.99 and 0.47, compared to 0.58 and 1.0 for PubMed Entrez, respectively.
A comprehensive mentoring program includes a variety of components. One of the most important is the ongoing assessment of and feedback to mentors. Scholars need strong active mentors who have the expertise, disposition, motivation, skills, and the ability to accept feedback and to adjust their mentoring style. Assessing the effectiveness of a given mentor is no easy task. Variability in learning needs and academic goals among scholars makes it difficult to develop a single evaluation instrument or a standardized procedure for evaluating mentors. Scholars, mentors, and program leaders are often reluctant to conduct formal evaluations, as there are no commonly accepted measures. The process of giving feedback is often difficult and there is limited empirical data on efficacy. This article presents a new and innovative six-component approach to mentor evaluation that includes the assessment of mentee training and empowerment, peer learning and mentor training, scholar advocacy, mentee–mentor expectations, mentor self-reflection, and mentee evaluation of their mentor.
mentors; evaluation; outcomes
Although the importance of research mentorship has been well established, the role of mentors of junior clinical and translational science investigators is not clearly defined. The authors attempt to derive a list of actionable competencies for mentors from a series of complementary methods. We examined focus groups, the literature, competencies derived for clinical and translational scholars, mentor training curricula, mentor evaluation forms and finally conducted an expert panel process in order to compose this list. These efforts resulted in a set of competencies that include generic competencies expected of all mentors, competencies specific to scientists, and competencies that are clinical and translational research specific. They are divided into six thematic areas: (1) Communication and managing the relationship, (2) Psychosocial support, (3) Career and professional development, (4) Professional enculturation and scientific integrity, (5) Research development, and (6) Clinical and translational investigator development. For each thematic area, we have listed associated competencies, 19 in total. For each competency, we list examples that are actionable and measurable. Although a comprehensive approach was used to derive this list of competencies, further work will be required to parse out how to apply and adapt them, as well future research directions and evaluation processes.
mentoring; mentor; competencies; translational
The mentoring relationship between a scholar and their primary mentor is a core feature of research training. Anecdotal evidence suggests this relationship is adversely affected when scholar and mentor expectations are not aligned. We examined three questions: (1) What is the value in assuring that the expectations of scholars and mentors are mutually identified and aligned? (2) What types of programmatic interventions facilitate this process? (3) What types of expectations are important to identify and align? We addressed these questions through a systematic literature review, focus group interviews of mentors and scholars, a survey of Clinical and Translational Science Award (CTSA) KL2 program directors, and review of formal programmatic mechanisms used by KL2 programs. We found broad support for the importance of identifying and aligning the expectations of scholars and mentors and evidence that mentoring contracts, agreements, and training programs facilitate this process. These tools focus on aligning expectations with respect to the scholar’s research, education, professional development and career advancement as well as support, communication, and personal conduct and interpersonal relations. Research is needed to assess test the efficacy of formal alignment activities.
mentors; mentoring; career development; faculty development; staff development
A little more than 10 years ago, the completed sequencing of the human genome boldly promised to usher in an era of enhanced understanding and accelerated development of treatments for most human diseases. Ten years later, many of these therapeutic goals have not been reached, but genomic technologies have dramatically enhanced our understanding of how genes and gene networks contribute to the pathogenesis of disease. In this review, we describe how genomic technologies have shaped our study of idiopathic pulmonary fibrosis (IPF), a devastating, progressive scarring of the lung parenchyma, a disease without a known cause, or treatment. We frame the important genomic discoveries in IPF of the previous decade in the clinical context of establishing a diagnosis of IPF and predicting the prognosis. Gene expression profiling of peripheral blood will help identify potential biomarkers for assessing the clinical severity of IPF. We highlight the growth of epigenetic research in IPF, including the contribution of microRNAs to the pathogenesis of disease. We suggest that the full power of genomic discoveries in IPF will be realized when researchers apply these techniques prospectively in large collaborative studies across institutions, support the training of young investigators in genomics, and employ systems biology approaches to the interpretation of genomic data.
lung; genetics; genes
Enteroendocrine cells (EECs) play a key role in nutrient digestion and absorption, and are essential for normal life. Recently, EEC function has received considerable attention because several gastrointestinal hormones modulate insulin secretion and food intake; and, gut hormone-based therapies have been developed to treat diabetes mellitus. Despite these advances, the regulation of EECs remains poorly understood. The development of transgenic mouse models that express green fluorescent proteins (GFP) under specific hormone promoters (e.g., peptide YY-GFP) is shedding light onto previously overlooked features of EECs. These cells have prominent cytoplasmic processes that extend underneath enterocytes, and in some EECs, like the L cell of the distal ileum, the basal process can be over 50 μm long. These basal cytoplasmic processes resemble axons and end in synaptic-like buttons. The location and anatomy of these processes suggest two functions: (1) to monitor absorbed nutrients at the base of enterocytes; and (2) to convey electrochemical information through cell-cell connections with subepithelial myofibroblasts and nerves located directly beneath in the lamina propria. Understanding how EECs communicate with cells in the lamina propria may provide novel ways to treat metabolic disorders such as obesity and diabetes.
The contribution of copy number variation (CNV) to dilated cardiomyopathy (DCM) is unknown. However, estimates have suggested that CNV’s could constitute 15% of mutations underlying Mendelian disease. This is of particular relevance to DCM, where only ~35% of genetic cause has been identified. We have previously reported 19 point mutations in LMNA, the gene encoding Lamin A/C, in a cohort of 324 unrelated DCM probands (5.9%), making it the most common genetic cause of DCM. Recently a large deletion was reported in LMNA in 1 of 25 unrelated DCM probands. To further assess the contribution of CNV’s in LMNA cardiomyopathy, we used Multiplex Ligation Probe Amplification (MLPA) to screen for large deletions and duplications in 58 unrelated DCM probands negative for point mutations in LMNA. Despite excellent quality control and robust MLPA results, our study failed to identify any deletions or duplications. We conclude that at least for LMNA, point mutations are the major source of DCM causation.
In an emerging field such as clinical and translational science, questions of purpose and educational philosophy are crucial to consider as programs, competencies, and milestones are developed and become generally accepted as broad national standards. This article outlines issues to be taken into account as curricula are planned, implemented, and evaluated. It also discusses how philosophy, competencies, and assessments, including milestones, must be intertwined purposefully, with careful attention paid to the integration of knowledge, skills, and attitudes.
doctoral education; competency; assessment; curriculum; milestones; clinical and translational science
Obesity disproportionately affects Latina women. Common genetic variants are convincingly associated with BMI and may be used to create genetic risk scores (GRS) for obesity that could define genetically influenced forms of obesity and alter response to clinical trial interventions. The objective of this study was: 1) to identify the frequency and effect size of common obesity genetic variants in Latina women; 2) to determine the clinical utility of a GRS for obesity with Latina women participating in a community-based clinical trial. DNA from 85 Latina women was genotyped for 8 genetic variants previously associated with BMI in Caucasians, but not yet assessed in Latina populations. The main outcome measure was the correlation of GRS (sum of 8 risk alleles) with BMI, waist circumference, and percent body fat. A majority (83%) of participants had a BMI ≥ 25. Frequency of loci near FTO, MC4R, and GNPDA2 were lower in Latinas than Caucasians. Association of each locus with BMI was lower in Latinas compared to Caucasians with no significant correlations with BMI. We conclude that an 8 locus GRS has no clinical utility for explaining obesity or predicting response to intervention in Latina women participating in a clinical trial.
Approximately 20% of patients with idiopathic dilated cardiomyopathy (iDCM) have autoantibodies (AAbs) specific to cardiac troponin-I (cTnI). However, there has been no work evaluating active cellular autoimmunity. We aimed to identify a cTnI-stimulated cellular autoimmune response and to correlate our findings with cTnI AAb production.
Samples were obtained from stable ambulatory iDCM patients and healthy controls. Peripheral blood monocytes were incubated with cTnI, and cellular proliferation was measured using flow cytometry. AAbs against cTnI were detected by ELISA.
A positive cellular proliferative response to cTnI was identified in 20.5% (9/44) patients with iDCM and 5.7% (2/35) of healthy controls (p < 0.05). Positive cTnI AAbs were identified in 20% (7/35) of healthy controls and 13.6% (6/44) of patients with iDCM (p = NS). The presence of cTnI AAbs did not correlate with a positive cellular proliferative response. However, patients with iDCM who had an AAb response to cTnI were less likely to be taking a statin (p < 0.05).
A cellular autoimmune response to cTnI is demonstrated in a subset of patients with iDCM. However, the presence of a cellular response did not correlate with the presence of AAbs to the same antigen.
Platelets play a major role in the metastatic dissemination of tumor cells in vivo. Recent evidence reveals megakaryocyte-derived platelet pre-mRNA is spliced to mRNA and then translated into functional proteins in response to external stimulation. Employing a human lung cancer model, we hypothesized a subset of megakaryocyte/platelet genes exists that are significantly over or underexpressed in metastasis compared with non-cancer. Microarray analysis employing platelet mRNA followed by unsupervised hierarchical clustering revealed an expression profile that includes decreased expression of 197 of the 200 platelet genes with the most altered expression (P<1.0×10-4). Among the 608 splicing events identified between the metastasis and negative control groups, 33 highly variable genes were identified with between 3 and 13 splicing events each. In conclusion this preliminary study reveals a platelet-based gene expression signature that differentiates metastatic lung cancer from negative controls on the basis of decreased expression of 197 of the 200 genes with the most altered expression levels. Further study may yield a prognostic tool for future metastasis among subsets of early stage lung cancer patients.
Sepsis often causes impaired hepatic function. Patients with liver disease have an increased risk of bacteremia. This is thought to be secondary to impaired reticuloendothelial system function. However, this has not been demonstrated clinically. Since transient bacteremia occurs following toothbrushing, we hypothesized that subjects with cirrhosis would have impaired bacterial clearance following toothbrushing compared with subjects with pulmonary disease and healthy controls. After baseline blood was drawn, the subjects underwent a dental examination to determine plaque index and gingival index. Following toothbrushing, blood was drawn at 30 seconds, 5 minutes, and 15 minutes. Bacteremia was measured using quantitative real-time PCR with primers that amplify all known bacteria. We found greater than 75% incidence of bacteremia following toothbrushing. While control and pulmonary subjects were able to clear this bacteremia, subjects with cirrhosis had prolonged bacteremia. Baseline and peak bacterial load correlated with plaque index, suggesting that dental hygiene predicts the degree of bacteremia. However, only the severity of cirrhosis was predictive of bacterial clearance at 15 minutes, suggesting that liver function is important in clearing bacteremia. In this study, we demonstrate clinically that cirrhosis results in impaired bacterial clearance. This suggests that cirrhotic patients may be more susceptible to sepsis because of ineffective bacterial clearance.
sepsis; cirrhosis; infection; bacteria; periodontal disease
Over the past two decades, the health research enterprise has matured rapidly, and many recognize an urgent need to translate pertinent research results into practice, to help improve the quality, accessibility, and affordability of U.S. health care. Streamlining research operations would speed translation, particularly for multi-site collaborations. However, the culture of research discourages reusing or adapting existing resources or study materials. Too often, researchers start studies and multi-site collaborations from scratch—reinventing the wheel. Our team developed a compendium of resources to address inefficiencies and researchers’ unmet needs and compiled them in a research toolkit website (www.ResearchToolkit.org). Through our work, we identified philosophical and operational issues related to disseminating the toolkit to the research community. We explore these issues here, with implications for the nation’s investment in biomedical research.
Prostaglandin E2 (PGE2), interleukin (IL)-23, and IL-1beta (β) propagate inflammatory bowel disease (IBD) by enhancing the development and function of IL-17 producing CD4+ T helper (Th17) cells. CD4+ T cells that express the C-type lectin-like receptor CD161 have been proposed to be the physiologic pool of circulating Th17 cells implicated in IBD. We sought to understand how PGE2, alone and in combination with IL-23 and IL-1β, modulate human peripheral CD161+ CD4+ memory T cells. We found that CD161+ cells comprise a significant proportion of human peripheral CD4+ memory T cells. PGE2 and IL-23 plus IL-1β synergistically induced early IL-17A secretion from CD161+CD4+ memory T cells and the selective enrichment of IL-17A+CD161+CD4+ memory T cells in culture. Conversely, IL-23 plus IL-1β partially opposed the PGE2-mediated repression of early IFN-γ secretion from CD161+ cells, as well as the PGE2-mediated depletion of IFN-γ+CD161+ cells. Our results suggest that PGE2 and IL-23 plus IL-1β induce the Th17 immune response preferentially in CD161+CD4+ memory T cells, while divergently regulating their ability to express IFN-γ. We hypothesize that Th17-mediated chronic inflammation in IBD depends on the net response of CD161+CD4+ memory T cells to both PGE2 and IL-23 plus IL-1β.
The journey of gene transfer from laboratory to clinic has been slow and fraught with many challenges and barriers. Despite the development of the initial technology in the early 1970s, a standard clinical treatment involving “gene therapy” remains to be seen. Furthermore, much was written about the technology in the early 1990s, but since then, not much has been written about the journey of gene transfer. The translational path of gene transfer thus far, both pitfalls and successes, can serve as a study not only in navigating ethical and safety concerns, but also in the importance of scientist-public interactions. Here, we examine the translational progress of gene transfer and what can be gleaned from its history.