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1.
Cancer Res ; 84(9): 1517-1533, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38587552

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by an immunosuppressive tumor microenvironment enriched with cancer-associated fibroblasts (CAF). This study used a convergence approach to identify tumor cell and CAF interactions through the integration of single-cell data from human tumors with human organoid coculture experiments. Analysis of a comprehensive atlas of PDAC single-cell RNA sequencing data indicated that CAF density is associated with increased inflammation and epithelial-mesenchymal transition (EMT) in epithelial cells. Transfer learning using transcriptional data from patient-derived organoid and CAF cocultures provided in silico validation of CAF induction of inflammatory and EMT epithelial cell states. Further experimental validation in cocultures demonstrated integrin beta 1 (ITGB1) and vascular endothelial factor A (VEGFA) interactions with neuropilin-1 mediating CAF-epithelial cell cross-talk. Together, this study introduces transfer learning from human single-cell data to organoid coculture analyses for experimental validation of discoveries of cell-cell cross-talk and identifies fibroblast-mediated regulation of EMT and inflammation. SIGNIFICANCE: Adaptation of transfer learning to relate human single-cell RNA sequencing data to organoid-CAF cocultures facilitates discovery of human pancreatic cancer intercellular interactions and uncovers cross-talk between CAFs and tumor cells through VEGFA and ITGB1.


Subject(s)
Cancer-Associated Fibroblasts , Carcinoma, Pancreatic Ductal , Coculture Techniques , Epithelial-Mesenchymal Transition , Inflammation , Integrin beta1 , Pancreatic Neoplasms , Single-Cell Analysis , Tumor Microenvironment , Humans , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/genetics , Cancer-Associated Fibroblasts/metabolism , Cancer-Associated Fibroblasts/pathology , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/genetics , Inflammation/pathology , Inflammation/metabolism , Integrin beta1/metabolism , Integrin beta1/genetics , Organoids/pathology , Organoids/metabolism , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor A/genetics , Neuropilin-1/metabolism , Neuropilin-1/genetics , Gene Expression Regulation, Neoplastic , Cell Line, Tumor , Cell Communication
2.
JCI Insight ; 8(23)2023 Dec 08.
Article in English | MEDLINE | ID: mdl-38063199

ABSTRACT

Personalized cancer vaccines aim to activate and expand cytotoxic antitumor CD8+ T cells to recognize and kill tumor cells. However, the role of CD4+ T cell activation in the clinical benefit of these vaccines is not well defined. We previously established a personalized neoantigen vaccine (PancVAX) for the pancreatic cancer cell line Panc02, which activates tumor-specific CD8+ T cells but required combinatorial checkpoint modulators to achieve therapeutic efficacy. To determine the effects of neoantigen-specific CD4+ T cell activation, we generated a vaccine (PancVAX2) targeting both major histocompatibility complex class I- (MHCI-) and MHCII-specific neoantigens. Tumor-bearing mice vaccinated with PancVAX2 had significantly improved control of tumor growth and long-term survival benefit without concurrent administration of checkpoint inhibitors. PancVAX2 significantly enhanced priming and recruitment of neoantigen-specific CD8+ T cells into the tumor with lower PD-1 expression after reactivation compared with the CD8+ vaccine alone. Vaccine-induced neoantigen-specific Th1 CD4+ T cells in the tumor were associated with decreased Tregs. Consistent with this, PancVAX2 was associated with more proimmune myeloid-derived suppressor cells and M1-like macrophages in the tumor, demonstrating a less immunosuppressive tumor microenvironment. This study demonstrates the biological importance of prioritizing and including CD4+ T cell-specific neoantigens for personalized cancer vaccine modalities.


Subject(s)
Cancer Vaccines , Pancreatic Neoplasms , Mice , Animals , CD4-Positive T-Lymphocytes , Antigens, Neoplasm , Vaccine Efficacy , Pancreatic Neoplasms/metabolism , Tumor Microenvironment
3.
Nat Protoc ; 18(12): 3690-3731, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37989764

ABSTRACT

Non-negative matrix factorization (NMF) is an unsupervised learning method well suited to high-throughput biology. However, inferring biological processes from an NMF result still requires additional post hoc statistics and annotation for interpretation of learned features. Here, we introduce a suite of computational tools that implement NMF and provide methods for accurate and clear biological interpretation and analysis. A generalized discussion of NMF covering its benefits, limitations and open questions is followed by four procedures for the Bayesian NMF algorithm Coordinated Gene Activity across Pattern Subsets (CoGAPS). Each procedure will demonstrate NMF analysis to quantify cell state transitions in a public domain single-cell RNA-sequencing dataset. The first demonstrates PyCoGAPS, our new Python implementation that enhances runtime for large datasets, and the second allows its deployment in Docker. The third procedure steps through the same single-cell NMF analysis using our R CoGAPS interface. The fourth introduces a beginner-friendly CoGAPS platform using GenePattern Notebook, aimed at users with a working conceptual knowledge of data analysis but without a basic proficiency in the R or Python programming language. We also constructed a user-facing website to serve as a central repository for information and instructional materials about CoGAPS and its application programming interfaces. The expected timing to setup the packages and conduct a test run is around 15 min, and an additional 30 min to conduct analyses on a precomputed result. The expected runtime on the user's desired dataset can vary from hours to days depending on factors such as dataset size or input parameters.


Subject(s)
Algorithms , Programming Languages , Bayes Theorem , Single-Cell Analysis
4.
bioRxiv ; 2023 Nov 05.
Article in English | MEDLINE | ID: mdl-37745323

ABSTRACT

Cells are fundamental units of life, constantly interacting and evolving as dynamical systems. While recent spatial multi-omics can quantitate individual cells' characteristics and regulatory programs, forecasting their evolution ultimately requires mathematical modeling. We develop a conceptual framework-a cell behavior hypothesis grammar-that uses natural language statements (cell rules) to create mathematical models. This allows us to systematically integrate biological knowledge and multi-omics data to make them computable. We can then perform virtual "thought experiments" that challenge and extend our understanding of multicellular systems, and ultimately generate new testable hypotheses. In this paper, we motivate and describe the grammar, provide a reference implementation, and demonstrate its potential through a series of examples in tumor biology and immunotherapy. Altogether, this approach provides a bridge between biological, clinical, and systems biology researchers for mathematical modeling of biological systems at scale, allowing the community to extrapolate from single-cell characterization to emergent multicellular behavior.

5.
Magn Reson Imaging Clin N Am ; 31(1): 65-78, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36368863

ABSTRACT

MR imaging is useful in the detection and characterization of adnexal lesions. This review discusses the clinical findings and MR imaging appearances of two types of ovarian neoplasms: germ cell and sex cord stromal tumors. The most common of these lesions, mature cystic teratomas, is characterized by the presence of bulk fat on MR imaging. Some of the other germ cell neoplasms and sex cord stromal tumors may have suggestive clinical, laboratory, or MR imaging features (eg, lipid and fibrosis) to establish a diagnosis. The ability to differentiate benign tumors from possible malignancy can aid in patient management.


Subject(s)
Neoplasms, Germ Cell and Embryonal , Ovarian Neoplasms , Sex Cord-Gonadal Stromal Tumors , Female , Humans , Magnetic Resonance Imaging , Neoplasms, Germ Cell and Embryonal/diagnostic imaging , Ovarian Neoplasms/diagnostic imaging , Sex Cord-Gonadal Stromal Tumors/diagnostic imaging
6.
Cancer Cell ; 40(11): 1374-1391.e7, 2022 11 14.
Article in English | MEDLINE | ID: mdl-36306792

ABSTRACT

Successful pancreatic ductal adenocarcinoma (PDAC) immunotherapy necessitates optimization and maintenance of activated effector T cells (Teff). We prospectively collected and applied multi-omic analyses to paired pre- and post-treatment PDAC specimens collected in a platform neoadjuvant study of granulocyte-macrophage colony-stimulating factor-secreting allogeneic PDAC vaccine (GVAX) vaccine ± nivolumab (anti-programmed cell death protein 1 [PD-1]) to uncover sensitivity and resistance mechanisms. We show that GVAX-induced tertiary lymphoid aggregates become immune-regulatory sites in response to GVAX + nivolumab. Higher densities of tumor-associated neutrophils (TANs) following GVAX + nivolumab portend poorer overall survival (OS). Increased T cells expressing CD137 associated with cytotoxic Teff signatures and correlated with increased OS. Bulk and single-cell RNA sequencing found that nivolumab alters CD4+ T cell chemotaxis signaling in association with CD11b+ neutrophil degranulation, and CD8+ T cell expression of CD137 was required for optimal T cell activation. These findings provide insights into PD-1-regulated immune pathways in PDAC that should inform more effective therapeutic combinations that include TAN regulators and T cell activators.


Subject(s)
Adenocarcinoma , Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/genetics , Adenocarcinoma/drug therapy , Adenocarcinoma/genetics , Neoadjuvant Therapy , Tumor Microenvironment , Nivolumab/therapeutic use , Nivolumab/pharmacology , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/genetics , Pancreatic Neoplasms
7.
Sci Immunol ; 7(68): eabi6763, 2022 02 11.
Article in English | MEDLINE | ID: mdl-35148201

ABSTRACT

Proteasome dysfunction can lead to autoinflammatory disease associated with elevated type I interferon (IFN-αß) and NF-κB signaling; however, the innate immune pathway driving this is currently unknown. Here, we identified protein kinase R (PKR) as an innate immune sensor for proteotoxic stress. PKR activation was observed in cellular models of decreased proteasome function and in multiple cell types from patients with proteasome-associated autoinflammatory disease (PRAAS). Furthermore, genetic deletion or small-molecule inhibition of PKR in vitro ameliorated inflammation driven by proteasome deficiency. In vivo, proteasome inhibitor-induced inflammatory gene transcription was blunted in PKR-deficient mice compared with littermate controls. PKR also acted as a rheostat for proteotoxic stress by triggering phosphorylation of eIF2α, which can prevent the translation of new proteins to restore homeostasis. Although traditionally known as a sensor of RNA, under conditions of proteasome dysfunction, PKR sensed the cytoplasmic accumulation of a known interactor, interleukin-24 (IL-24). When misfolded IL-24 egress into the cytosol was blocked by inhibition of the endoplasmic reticulum-associated degradation pathway, PKR activation and subsequent inflammatory signaling were blunted. Cytokines such as IL-24 are normally secreted from cells; therefore, cytoplasmic accumulation of IL-24 represents an internal danger-associated molecular pattern. Thus, we have identified a mechanism by which proteotoxic stress is detected, causing inflammation observed in the disease PRAAS.


Subject(s)
Immunity, Innate/immunology , Interleukins/immunology , eIF-2 Kinase/immunology , Animals , Cells, Cultured , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , eIF-2 Kinase/deficiency
8.
Postgrad Med ; 133(8): 953-963, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34533099

ABSTRACT

BACKGROUND: Relapsing polychondritis (RPC) is a complex immune-mediated systemic disease affecting cartilaginous tissue and proteoglycan-rich organs. The most common and earliest clinical features are intermittent inflammation involving the auricular and nasal regions, although all cartilage types can be potentially affected. The life-threatening effects of rpc involve the tracheobronchial tree and cardiac connective components. Rpc is difficult to identify among other autoimmune comorbidities; diagnosis is usually delayed and based on nonspecific clinical symptoms with limited laboratory aid and investigations. Medications can vary, from steroids, immunosuppressants, and biologics, including anti-tnf alpha antagonist drugs. METHOD: Information on updated etiology, clinical symptoms, diagnosis, and treatment of rpc has been obtained via extensive research of electronic literature published between 1976 and 2019 using PubMed and medline databases. English was the language of use. Search inputs included 'relapsing polychondritis,' 'polychondritis,' 'relapsing polychondritis symptoms,' and 'treatment of relapsing polychondritis.' Published articles in English that outlined and reported rpc's clinical manifestations and treatment ultimately met the inclusion criteria. Articles that failed to report the above and reported on other cartilaginous diseases met the exclusion criteria. RESULT: Utilizing an extensive overview of work undertaken in critical areas of RPC research, this review intends to further explore and educate the approach to this disease in all dimensions from pathophysiology, diagnosis, and management. CONCLUSION: RPC is a rare multi-systemic autoimmune disease and possibly fatal. The management remains empiric and is identified based on the severity of the disease per case. The optimal way to advance is to continue sharing data on RPC from reference centers; furthermore, clinical trials in randomized control groups must provide evidence-based treatment and management. Acquiring such information will refine the current knowledge of RPC, which will improve not only treatment but also diagnostic methods, including imaging and biological markers.


Subject(s)
Biological Products/therapeutic use , Immunosuppressive Agents/therapeutic use , Polychondritis, Relapsing/diagnosis , Polychondritis, Relapsing/drug therapy , Polychondritis, Relapsing/physiopathology , Tumor Necrosis Factor Inhibitors/therapeutic use , Ear Diseases/drug therapy , Ear Diseases/physiopathology , Female , Humans , Male , Middle Aged , Nose Diseases/drug therapy , Nose Diseases/physiopathology , Polychondritis, Relapsing/etiology , Prevalence , Symptom Assessment , Treatment Outcome
9.
Nanomaterials (Basel) ; 11(8)2021 Aug 20.
Article in English | MEDLINE | ID: mdl-34443952

ABSTRACT

Graphene-based point-of-care (PoC) and chemical sensors can be fabricated using photolithographic processes at wafer-scale. However, these approaches are known to leave polymer residues on the graphene surface, which are difficult to remove completely. In addition, graphene growth and transfer processes can introduce defects into the graphene layer. Both defects and resist contamination can affect the homogeneity of graphene-based PoC sensors, leading to inconsistent device performance and unreliable sensing. Sensor reliability is also affected by the harsh chemical environments used for chemical functionalisation of graphene PoC sensors, which can degrade parts of the sensor device. Therefore, a reliable, wafer-scale method of passivation, which isolates the graphene from the rest of the device, protecting the less robust device features from any aggressive chemicals, must be devised. This work covers the application of molecular vapour deposition technology to create a dielectric passivation film that protects graphene-based biosensing devices from harsh chemicals. We utilise a previously reported "healing effect" of Al2O3 on graphene to reduce photoresist residue from the graphene surface and reduce the prevalence of graphene defects to improve graphene device homogeneity. The improvement in device consistency allows for more reliable, homogeneous graphene devices, that can be fabricated at wafer-scale for sensing and biosensing applications.

10.
Front Immunol ; 12: 636225, 2021.
Article in English | MEDLINE | ID: mdl-33833757

ABSTRACT

Gain-of-function mutations in STING1 cause the monogenic interferonopathy, SAVI, which presents with early-onset systemic inflammation, cold-induced vasculopathy and/or interstitial lung disease. We identified 5 patients (3 kindreds) with predominantly peripheral vascular disease who harbor 3 novel STING1 variants, p.H72N, p.F153V, and p.G158A. The latter two were predicted by a previous cryo-EM structure model to cause STING autoactivation. The p.H72N variant in exon 3, however, is the first SAVI-causing variant in the transmembrane linker region. Mutations of p.H72 into either charged residues or hydrophobic residues all led to dramatic loss of cGAMP response, while amino acid changes to residues with polar side chains were able to maintain the wild type status. Structural modeling of these novel mutations suggests a reconciled model of STING activation, which indicates that STING dimers can oligomerize in both open and closed states which would obliviate a high-energy 180° rotation of the ligand-binding head for STING activation, thus refining existing models of STING activation. Quantitative comparison showed that an overall lower autoactivating potential of the disease-causing mutations was associated with less severe lung disease, more severe peripheral vascular disease and the absence of a robust interferon signature in whole blood. Our findings are important in understanding genotype-phenotype correlation, designing targeted STING inhibitors and in dissecting differentially activated pathways downstream of different STING mutations.


Subject(s)
Inflammation/genetics , Lung Diseases, Interstitial/genetics , Membrane Proteins/genetics , Mutation , Peripheral Vascular Diseases/genetics , Adult , Child , DNA Mutational Analysis , Female , Genetic Predisposition to Disease , HEK293 Cells , Humans , Inflammation/diagnosis , Inflammation/metabolism , Inflammation/therapy , Lung Diseases, Interstitial/diagnosis , Lung Diseases, Interstitial/metabolism , Lung Diseases, Interstitial/therapy , Male , Membrane Proteins/metabolism , Middle Aged , Models, Molecular , Peripheral Vascular Diseases/diagnosis , Peripheral Vascular Diseases/metabolism , Peripheral Vascular Diseases/therapy , Phenotype , Protein Conformation , Protein Multimerization , Severity of Illness Index , Structure-Activity Relationship , Exome Sequencing , Young Adult
11.
Arthritis Rheumatol ; 73(6): 1021-1032, 2021 06.
Article in English | MEDLINE | ID: mdl-33314777

ABSTRACT

OBJECTIVE: To identify novel heterozygous LPIN2 mutations in a patient with Majeed syndrome and characterize the pathomechanisms that lead to the development of sterile osteomyelitis. METHODS: Targeted genetic analysis and functional studies assessing monocyte responses, macrophage differentiation, and osteoclastogenesis were conducted to compare the pathogenesis of Majeed syndrome to interleukin-1 (IL-1)-mediated diseases including neonatal-onset multisystem inflammatory disease (NOMID) and deficiency of the IL-1 receptor antagonist (DIRA). RESULTS: A 4-year-old girl of mixed ethnic background presented with sterile osteomyelitis and elevated acute-phase reactants. She had a 17.8-kb deletion on the maternal LPIN2 allele and a splice site mutation, p.R517H, that variably spliced out exons 10 and 11 on the paternal LPIN2 allele. The patient achieved long-lasting remission receiving IL-1 blockade with canakinumab. Compared to controls, monocytes and monocyte-derived M1-like macrophages from the patient with Majeed syndrome and those with NOMID or DIRA had elevated caspase 1 activity and IL-1ß secretion. In contrast, lipopolysaccharide-stimulated, monocyte-derived, M2-like macrophages from the patient with Majeed syndrome released higher levels of osteoclastogenic mediators (IL-8, IL-6, tumor necrosis factor, CCL2, macrophage inflammatory protein 1α/ß, CXCL8, and CXCL1) compared to NOMID patients and healthy controls. Accelerated osteoclastogenesis in the patient with Majeed syndrome was associated with higher NFATc1 levels, enhanced JNK/MAPK, and reduced Src kinase activation, and partially responded to JNK inhibition and IL-1 (but not IL-6) blockade. CONCLUSION: We report 2 novel compound heterozygous disease-causing mutations in LPIN2 in an American patient with Majeed syndrome. LPIN2 deficiency drives differentiation of proinflammatory M2-like macrophages and enhances intrinsic osteoclastogenesis. This provides a model for the pathogenesis of sterile osteomyelitis which differentiates Majeed syndrome from other IL-1-mediated autoinflammatory diseases.


Subject(s)
Anemia, Dyserythropoietic, Congenital/genetics , Immunologic Deficiency Syndromes/genetics , Inflammation/genetics , Macrophages/immunology , Nuclear Proteins/genetics , Osteogenesis/genetics , Osteomyelitis/genetics , Anemia, Dyserythropoietic, Congenital/drug therapy , Anemia, Dyserythropoietic, Congenital/immunology , Antibodies, Monoclonal, Humanized/therapeutic use , Case-Control Studies , Child, Preschool , Cryopyrin-Associated Periodic Syndromes/genetics , Cryopyrin-Associated Periodic Syndromes/immunology , Female , Hereditary Autoinflammatory Diseases/genetics , Hereditary Autoinflammatory Diseases/immunology , Heterozygote , Humans , Immunologic Deficiency Syndromes/drug therapy , Immunologic Deficiency Syndromes/immunology , Inflammation/immunology , Interleukin 1 Receptor Antagonist Protein/genetics , Interleukin 1 Receptor Antagonist Protein/immunology , MAP Kinase Kinase 4/metabolism , Mitogen-Activated Protein Kinases/metabolism , NFATC Transcription Factors/metabolism , Nuclear Proteins/immunology , Osteomyelitis/drug therapy , Osteomyelitis/immunology , src-Family Kinases/metabolism
12.
Nanomaterials (Basel) ; 10(9)2020 Sep 10.
Article in English | MEDLINE | ID: mdl-32927839

ABSTRACT

Affinity biosensors based on graphene field-effect transistor (GFET) or resistor designs require the utilization of graphene's exceptional electrical properties. Therefore, it is critical when designing these sensors, that the electrical properties of graphene are maintained throughout the functionalization process. To that end, non-covalent functionalization may be preferred over covalent modification. Drop-cast 1,5-diaminonaphthalene (DAN) was investigated as a quick and simple method for the non-covalent amine functionalization of carbon-based surfaces such as graphene, for use in biosensor development. In this work, multiple graphene surfaces were functionalized with DAN via a drop-cast method, leading to amine moieties, available for subsequent attachment to receptor molecules. Successful modification of graphene with DAN via a drop-cast method was confirmed using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and real-time resistance measurements. Successful attachment of receptor molecules also confirmed using the aforementioned techniques. Furthermore, an investigation into the effect of sequential wash steps which are required in biosensor manufacture, on the presence of the DAN layer, confirmed that the functional layer was not removed, even after multiple solvent exposures. Drop-cast DAN is thus, a viable fast and robust method for the amine functionalization of graphene surfaces for use in biosensor development.

14.
Child Care Health Dev ; 46(1): 132-148, 2020 01.
Article in English | MEDLINE | ID: mdl-31782542

ABSTRACT

BACKGROUND: Children and adolescents with neurodevelopmental disabilities may be less well integrated into their community than their peers. Online groups can be particularly accessible for individuals with neurodevelopmental disabilities, as individuals may be able to connect with a larger network than they would in their local community. This systematic review aimed at estimating the effectiveness of online peer mentorship programmes on children and adolescent's participation in life situations. METHODS: A systematic review was conducted to search Medline, PsycINFO, Embase, CINAHL, and Education Research Complete (ERIC) electronic databases. Thematic analysis was done for studies that used qualitative methodology. RESULTS: Eleven articles were included, and they examined the influences of five different structured online peer mentorship intervention programmes and six different online support groups. The disabilities included cerebral palsy (n = 3), autism spectrum disorder (n = 3), spina bifida (n = 2), attention deficit hyperactivity disorder (n = 2), and other neurodevelopmental disorders. The mentors included in the studies were caregivers of children with disabilities, youth and adults with disabilities, and a virtual peer actor. The mentees included in the studies were youth with disabilities (age 10-19 years) and their families. Intervention characteristics varied across the studies but consistently showed a unique potential to facilitate social networking and support. Intervention programmes with specific content and structure showed better participation outcomes than unstructured interventions. Presence of a moderator and participant characteristics (age and sociocultural background) was suggested to influence the outcomes of interventions. CONCLUSIONS: Online peer mentorship programmes appear to have positive influence on social engagement and participation in life situation for children and adolescents with disabilities. This paper discusses several areas that should be considered in future research studies to improve potential effectiveness and use of study designs that help to establish not only if interventions work but also for whom they work best and why.


Subject(s)
Internet , Mentors , Neurodevelopmental Disorders/psychology , Neurodevelopmental Disorders/therapy , Peer Group , Adolescent , Child , Humans , Social Behavior , Social Participation , Young Adult
15.
Abdom Radiol (NY) ; 44(9): 3133-3138, 2019 09.
Article in English | MEDLINE | ID: mdl-31139885

ABSTRACT

OBJECTIVE: Determine normal T1 and extracellular volume (ECV) of the pancreas in subjects with no pancreas disease and correlate with age and gender. SUBJECTS AND METHODS: We imaged 120 healthy subjects (age range 20-78 years) who are on annual screening with MRI/MRCP for the possibility of pancreatic cancer. Subjects had a predisposition to develop pancreatic cancer, but no history of pancreas disease or acute symptoms. Equal number (n = 60) of subjects were scanned on either 1.5 T or 3 T scanner using dual flip angle spoiled gradient echo technique incorporating fat suppression and correction for B1 field inhomogeneity. Optimization of imaging parameters was performed using a T1 phantom. ECV was calculated using pre- and post-contrast T1 of the pancreas and plasma. Regression analysis and Mann-Whitney tests were used for statistical analysis. RESULTS: Median T1 on 1.5 T was 654 ms (IQR 608-700); median T1 on 3 T was 717 ms (IQR 582-850); median ECV on 1.5 T was 0.28 (IQR 0.21-0.33), and median ECV on 3 T was 0.25 (IQR 0.19-0.28). Age had a mild positive correlation with T1 (r = 0.24, p = 0.009), but not with ECV (r = 0.06, p = 0.54). T1 and ECV were similar in both genders (p > 0.05). CONCLUSION: This study measured the median T1 and ECV of the pancreas in subjects with no pancreas disease. Pancreas shows longer T1 relaxation times in older population, whereas extracellular fraction remains unchanged. Median T1 values were different between two magnet strengths; however, no difference was seen between genders and ECV fractions.


Subject(s)
Magnetic Resonance Imaging/methods , Pancreas/anatomy & histology , Adult , Age Factors , Aged , Female , Humans , Male , Middle Aged , Organ Size , Reference Values , Reproducibility of Results , Sex Factors , Young Adult
17.
Proc Biol Sci ; 283(1825): 20160042, 2016 Feb 24.
Article in English | MEDLINE | ID: mdl-26911963

ABSTRACT

RNA interference (RNAi) methods for insects are often limited by problems with double-stranded (ds) RNA delivery, which restricts reverse genetics studies and the development of RNAi-based biocides. We therefore delegated to insect symbiotic bacteria the task of: (i) constitutive dsRNA synthesis and (ii) trauma-free delivery. RNaseIII-deficient, dsRNA-expressing bacterial strains were created from the symbionts of two very diverse pest species: a long-lived blood-sucking bug, Rhodnius prolixus, and a short-lived globally invasive polyphagous agricultural pest, western flower thrips (Frankliniella occidentalis). When ingested, the manipulated bacteria colonized the insects, successfully competed with the wild-type microflora, and sustainably mediated systemic knockdown phenotypes that were horizontally transmissible. This represents a significant advance in the ability to deliver RNAi, potentially to a large range of non-model insects.


Subject(s)
Gene Targeting/methods , RNA Interference , RNA, Double-Stranded/genetics , Rhodnius/genetics , Rhodococcus/genetics , Thysanoptera/genetics , Animals , Rhodnius/microbiology , Sequence Analysis, DNA , Symbiosis , Thysanoptera/microbiology
18.
Ann Neurol ; 77(2): 320-32, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25515836

ABSTRACT

OBJECTIVE: Patients with myotonia congenita have muscle hyperexcitability due to loss-of-function mutations in the chloride channel in skeletal muscle, which causes spontaneous firing of muscle action potentials (myotonia), producing muscle stiffness. In patients, muscle stiffness lessens with exercise, a change known as the warmup phenomenon. Our goal was to identify the mechanism underlying warmup and to use this information to guide development of novel therapy. METHODS: To determine the mechanism underlying warmup, we used a recently discovered drug to eliminate muscle contraction, thus allowing prolonged intracellular recording from individual muscle fibers during induction of warmup in a mouse model of myotonia congenita. RESULTS: Changes in action potentials suggested slow inactivation of sodium channels as an important contributor to warmup. These data suggested that enhancing slow inactivation of sodium channels might offer effective therapy for myotonia. Lacosamide and ranolazine enhance slow inactivation of sodium channels and are approved by the US Food and Drug Administration for other uses in patients. We compared the efficacy of both drugs to mexiletine, a sodium channel blocker currently used to treat myotonia. In vitro studies suggested that both lacosamide and ranolazine were superior to mexiletine. However, in vivo studies in a mouse model of myotonia congenita suggested that side effects could limit the efficacy of lacosamide. Ranolazine produced fewer side effects and was as effective as mexiletine at a dose that produced none of mexiletine's hypoexcitability side effects. INTERPRETATION: We conclude that ranolazine has excellent therapeutic potential for treatment of patients with myotonia congenita.


Subject(s)
Chloride Channels/antagonists & inhibitors , Drug Delivery Systems/methods , Myotonia Congenita/drug therapy , Myotonia Congenita/physiopathology , Sodium Channel Blockers/administration & dosage , Acetanilides/administration & dosage , Animals , Chloride Channels/physiology , Mice , Mice, Transgenic , Muscle Contraction/drug effects , Muscle Contraction/physiology , Myotonia Congenita/genetics , Organ Culture Techniques , Piperazines/administration & dosage , Ranolazine
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