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1.
bioRxiv ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38979132

ABSTRACT

Nicotinamide adenine dinucleotide (NAD) is essential for many enzymatic reactions, including those involved in energy metabolism, DNA repair and the activity of sirtuins, a family of defensive deacylases. During aging, levels of NAD + can decrease by up to 50% in some tissues, the repletion of which provides a range of health benefits in both mice and humans. Whether or not the NAD + precursor nicotinamide mononucleotide (NMN) extends lifespan in mammals is not known. Here we investigate the effect of long-term administration of NMN on the health, cancer burden, frailty and lifespan of male and female mice. Without increasing tumor counts or severity in any tissue, NMN treatment of males and females increased activity, maintained more youthful gene expression patterns, and reduced overall frailty. Reduced frailty with NMN treatment was associated with increases in levels of Anerotruncus colihominis, a gut bacterium associated with lower inflammation in mice and increased longevity in humans. NMN slowed the accumulation of adipose tissue later in life and improved metabolic health in male but not female mice, while in females but not males, NMN increased median lifespan by 8.5%, possible due to sex-specific effects of NMN on NAD + metabolism. Together, these data show that chronic NMN treatment delays frailty, alters the microbiome, improves male metabolic health, and increases female mouse lifespan, without increasing cancer burden. These results highlight the potential of NAD + boosters for treating age-related conditions and the importance of using both sexes for interventional lifespan studies.

2.
Aging (Albany NY) ; 15(13): 5966-5989, 2023 07 12.
Article in English | MEDLINE | ID: mdl-37437248

ABSTRACT

A hallmark of eukaryotic aging is a loss of epigenetic information, a process that can be reversed. We have previously shown that the ectopic induction of the Yamanaka factors OCT4, SOX2, and KLF4 (OSK) in mammals can restore youthful DNA methylation patterns, transcript profiles, and tissue function, without erasing cellular identity, a process that requires active DNA demethylation. To screen for molecules that reverse cellular aging and rejuvenate human cells without altering the genome, we developed high-throughput cell-based assays that distinguish young from old and senescent cells, including transcription-based aging clocks and a real-time nucleocytoplasmic compartmentalization (NCC) assay. We identify six chemical cocktails, which, in less than a week and without compromising cellular identity, restore a youthful genome-wide transcript profile and reverse transcriptomic age. Thus, rejuvenation by age reversal can be achieved, not only by genetic, but also chemical means.


Subject(s)
Cellular Reprogramming , Induced Pluripotent Stem Cells , Animals , Humans , Cellular Reprogramming/genetics , Cellular Senescence/genetics , Aging/genetics , DNA Methylation , Mammals
3.
J Vasc Interv Radiol ; 33(3): 324-332.e2, 2022 03.
Article in English | MEDLINE | ID: mdl-34923098

ABSTRACT

PURPOSE: To show that a deep learning (DL)-based, automated model for Lipiodol (Guerbet Pharmaceuticals, Paris, France) segmentation on cone-beam computed tomography (CT) after conventional transarterial chemoembolization performs closer to the "ground truth segmentation" than a conventional thresholding-based model. MATERIALS AND METHODS: This post hoc analysis included 36 patients with a diagnosis of hepatocellular carcinoma or other solid liver tumors who underwent conventional transarterial chemoembolization with an intraprocedural cone-beam CT. Semiautomatic segmentation of Lipiodol was obtained. Subsequently, a convolutional U-net model was used to output a binary mask that predicted Lipiodol deposition. A threshold value of signal intensity on cone-beam CT was used to obtain a Lipiodol mask for comparison. The dice similarity coefficient (DSC), mean squared error (MSE), center of mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist-segmented Lipiodol deposits) to obtain accuracy metrics for the 2 masks. These results were used to compare the model versus the threshold technique. RESULTS: For all metrics, the U-net outperformed the threshold technique: DSC (0.65 ± 0.17 vs 0.45 ± 0.22, P < .001) and MSE (125.53 ± 107.36 vs 185.98 ± 93.82, P = .005). The difference between the CM predicted and the actual CM was 15.31 mm ± 14.63 versus 31.34 mm ± 30.24 (P < .001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22 ± 0.84 versus 2.58 ± 3.52 (P = .048) for the current model's prediction and threshold technique, respectively. CONCLUSIONS: This study showed that a DL framework could detect Lipiodol in cone-beam CT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intraprocedurally.


Subject(s)
Carcinoma, Hepatocellular , Chemoembolization, Therapeutic , Deep Learning , Liver Neoplasms , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/therapy , Chemoembolization, Therapeutic/methods , Cone-Beam Computed Tomography/methods , Ethiodized Oil , Humans , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/therapy
4.
Aging (Albany NY) ; 13(24): 25607-25642, 2021 12 30.
Article in English | MEDLINE | ID: mdl-34968192

ABSTRACT

Aging is accompanied by osteopenia, characterized by reduced bone formation and increased bone resorption. Osteocytes, the terminally differentiated osteoblasts, are regulators of bone homeostasis, and parathyroid hormone (PTH) receptor (PPR) signaling in mature osteoblasts/osteocytes is essential for PTH-driven anabolic and catabolic skeletal responses. However, the role of PPR signaling in those cells during aging has not been investigated. The aim of this study was to analyze the role of PTH signaling in mature osteoblasts/osteocytes during aging. Mice lacking PPR in osteocyte (Dmp1-PPRKO) display an age-dependent osteopenia characterized by a significant decrease in osteoblast activity and increase in osteoclast number and activity. At the molecular level, the absence of PPR signaling in mature osteoblasts/osteocytes is associated with an increase in serum sclerostin and a significant increase in osteocytes expressing 4-hydroxy-2-nonenals, a marker of oxidative stress. In Dmp1-PPRKO mice there was an age-dependent increase in p16Ink4a/Cdkn2a expression, whereas it was unchanged in controls. In vitro studies demonstrated that PTH protects osteocytes from oxidative stress-induced cell death. In summary, we reported that PPR signaling in osteocytes is important for protecting the skeleton from age-induced bone loss by restraining osteoclast's activity and protecting osteocytes from oxidative stresses.


Subject(s)
Osteoblasts/drug effects , Osteoclasts/drug effects , Osteocytes/drug effects , Parathyroid Hormone/pharmacology , Receptor, Parathyroid Hormone, Type 1/metabolism , Signal Transduction/drug effects , Animals , Bone Diseases, Metabolic/pathology , Bone Resorption/metabolism , Bone and Bones/cytology , Bone and Bones/drug effects , Bone and Bones/metabolism , Homeostasis/drug effects , Mice , Mice, Knockout , Osteoblasts/cytology , Osteoblasts/metabolism , Osteoclasts/cytology , Osteoclasts/metabolism , Osteocytes/metabolism , Osteoporosis/metabolism
6.
Clin Imaging ; 78: 194-200, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34022765

ABSTRACT

BACKGROUND: The use of the ethiodized oil- Lipiodol in conventional trans-arterial chemoembolization (cTACE) ensures radiopacity to visualize drug delivery in the process of providing selective drug targeting to hepatic cancers and arterial embolization. Lipiodol functions as a carrier of chemo drugs for targeted therapy, as an embolic agent, augmenting the drug effect by efflux into the portal veins as well as a predictor for the tumor response and survival. PURPOSE: To prospectively evaluate the role of 3D quantitative assessment of intra-procedural Lipiodol deposition in liver tumors on CBCT immediately after cTACE as a predictive biomarker for the outcome of cTACE. MATERIALS & METHODS: This was a post-hoc analysis of data from an IRB-approved prospective clinical trial. Thirty-two patients with hepatocellular carcinoma or liver metastases underwent contrast enhanced CBCT obtained immediately after cTACE, unenhanced MDCT at 24 h after cTACE, and follow-up imaging 30-, 90- and 180-days post-procedure. Lipiodol deposition was quantified on CBCT after cTACE and was characterized by 4 ordinal levels: ≤25%, >25-50%, >50-75%, >75%. Tumor response was assessed on follow-up MRI. Lipiodol deposition on imaging, correlation between Lipiodol deposition and tumor response criteria, and correlation between Lipiodol coverage and median overall survival (MOS) were evaluated. RESULTS: Image analysis demonstrated a high degree of agreement between the Lipiodol deposition on CBCT and the 24 h post-TACE CT, with a Bland-Altman plot of Lipiodol deposition on imaging demonstrated a bias of 2.75, with 95%-limits-of-agreement: -16.6 to 22.1%. An inverse relationship between Lipiodol deposition in responders versus non-responders for two-dimensional EASL reached statistical significance at 30 days (p = 0.02) and 90 days (p = 0.05). Comparing the Lipiodol deposition in Modified Response Evaluation Criteria in Solid Tumors (mRECIST) responders versus non-responders showed a statistically significant higher volumetric deposition in responders for European Association for the Study of the Liver (EASL)-30d, EASL-90d, and quantitative EASL-180d. The correlation between the relative Lipiodol deposition and the change in enhancing tumor volume showed a negative association post-cTACE (30-day: p < 0.001; rho = -0.63). A Kaplan-Meier analysis for patients with high vs. low Lipiodol deposition showed a MOS of 46 vs. 33 months (p = 0.05). CONCLUSION: 3D quantification of Lipiodol deposition on intra-procedural CBCT is a predictive biomarker of outcome in patients with primary or metastatic liver cancer undergoing cTACE. There are spatial and volumetric agreements between 3D quantification of Lipiodol deposition on intra-procedural CBCT and 24 h post-cTACE MDCT. The spatial and volumetric agreement between Lipiodol deposition on intra-procedural CBCT and 24 h post-cTACE MDCT could suggest that acquiring MDCT 24 h after cTACE is redundant. Importantly, the demonstrated relationship between levels of tumor coverage with Lipiodol and degree and timeline of tumor response after cTACE underline the role of Lipiodol as an intra-procedural surrogate for tumor response, with potential implications for the prediction of survival.


Subject(s)
Carcinoma, Hepatocellular , Chemoembolization, Therapeutic , Liver Neoplasms , Biomarkers , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/therapy , Ethiodized Oil , Humans , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/therapy , Prospective Studies , Retrospective Studies , Treatment Outcome
7.
Dig Dis Interv ; 5(4): 331-337, 2021.
Article in English | MEDLINE | ID: mdl-35005333

ABSTRACT

The future of radiology is disproportionately linked to the applications of artificial intelligence (AI). Recent exponential advancements in AI are already beginning to augment the clinical practice of radiology. Driven by a paucity of review articles in the area, this article aims to discuss applications of AI in non-oncologic IR across procedural planning, execution, and follow-up along with a discussion on the future directions of the field. Applications in vascular imaging, radiomics, touchless software interactions, robotics, natural language processing, post-procedural outcome prediction, device navigation, and image acquisition are included. Familiarity with AI study analysis will help open the current 'black box' of AI research and help bridge the gap between the research laboratory and clinical practice.

8.
Dev Comp Immunol ; 104: 103559, 2020 03.
Article in English | MEDLINE | ID: mdl-31751628

ABSTRACT

Herein, we characterize transcription factor NF-κB from the demosponge Amphimedon queenslandica (Aq). Aq-NF-κB is most similar to NF-κB p100/p105 among vertebrate proteins, with an N-terminal DNA-binding domain, a C-terminal Ankyrin (ANK) repeat domain, and a DNA binding-site profile akin to human NF-κB proteins. Like mammalian NF-κB p100, C-terminal truncation allows nuclear translocation of Aq-NF-κB and increases its transcriptional activation activity. Expression of IκB kinases (IKKs) induces proteasome-dependent C-terminal processing of Aq-NF-κB in human cells, and processing requires C-terminal serines in Aq-NF-κB. Unlike NF-κB p100, C-terminal sequences of Aq-NF-κB do not inhibit its DNA-binding activity. Tissue of a black encrusting demosponge contains NF-κB site DNA-binding activity, as well as nuclear and processed NF-κB. Treatment of sponge tissue with LPS increases both DNA-binding activity and processing of NF-κB. A. queenslandica transcriptomes contain homologs to upstream NF-κB pathway components. This is first functional characterization of NF-κB in sponge, the most basal multicellular animal.


Subject(s)
Conserved Sequence/genetics , DNA-Binding Proteins/genetics , NF-kappa B/genetics , Porifera/immunology , Protein Domains/genetics , Animals , DNA-Binding Proteins/metabolism , Evolution, Molecular , Gene Expression Regulation , NF-kappa B/metabolism , Signal Transduction , Transcription, Genetic
9.
Vet Surg ; 47(8): 1021-1030, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30307042

ABSTRACT

OBJECTIVE: To evaluate the effects of nanoparticle hyperthermia therapy on monocyte function and tumor-derived factors associated with macrophage polarization in a murine osteosarcoma model. STUDY DESIGN: Experimental study. ANIMALS: Female C3H mice. METHODS: Peripheral blood monocyte cell surface phenotype, monocyte chemotaxis, tumor messenger RNA expression, and survival were compared among osteosarcoma (OS)-bearing mice treated with nanoparticle hyperthermia therapy, OS-bearing mice with osteomyelitis, OS-bearing mice, vehicle control mice, and normal control mice. RESULTS: OS-bearing mice with osteomyelitis had a higher proportion of "nonclassical" monocytes (Ly6Clo ) compared with all other experimental groups. There were alterations in monocyte expression of multiple chemokine receptors among experimental groups including CXCR2, CCR2, and CXCR4. Monocytes from OS-bearing mice treated with hyperthermia therapy exhibited greater chemotaxis compared with monocytes from OS-bearing mice with osteomyelitis. CONCLUSION: OS likely induced alterations in monocyte phenotype and function. Nanoparticle hyperthermia therapy increased in vitro monocyte chemotaxis. CLINICAL IMPACT: Enhancing monocyte/macrophage function in dogs with OS may enhance antitumor immunity.


Subject(s)
Bone Neoplasms/veterinary , Dog Diseases/therapy , Hyperthermia, Induced/veterinary , Monocytes/physiology , Nanoparticles , Osteosarcoma/veterinary , Animals , Bone Neoplasms/therapy , Disease Models, Animal , Dog Diseases/blood , Dogs , Female , Mice , Mice, Inbred C3H , Osteosarcoma/therapy , Phenotype , Receptors, CXCR4/genetics
10.
Neuroimage ; 183: 985-993, 2018 12.
Article in English | MEDLINE | ID: mdl-30243955

ABSTRACT

In diffusion MRI (dMRI), static magnetic field (B0) inhomogeneity and time varying gradient eddy currents induce spatial distortions in reconstructed images. These distortions are exacerbated when high spatial resolutions are used, and many field-mapping based correction techniques often only acquire maps of static B0 distortion, which are not adequate for correcting eddy current induced image distortions. This report presents a novel technique, termed RPG-MUSE, for achieving distortion-free high-resolution diffusion MRI by integrating reversed polarity gradients (RPG) into the multi-shot echo planar imaging acquisition scheme used in multiplexed sensitivity encoding (MUSE). By alternating the phase encoding direction between shots in both baseline and diffusion-weighted acquisitions, maps of both static B0 and eddy current induced field inhomogeneities can be inherently derived, without the need for additional data acquisition. Through both 2D and 3D encoded dMRI acquisitions, it is shown that an RPG-MUSE reconstruction can simultaneously achieve high spatial resolution, high spatial fidelity, and subsequently, high accuracy in diffusion metrics.


Subject(s)
Artifacts , Brain Mapping/methods , Diffusion Magnetic Resonance Imaging/methods , Image Processing, Computer-Assisted/methods , Echo-Planar Imaging/methods , Humans
11.
FASEB J ; 32(1): 440-452, 2018 01.
Article in English | MEDLINE | ID: mdl-28928248

ABSTRACT

Osteocytes are master orchestrators of bone remodeling; they control osteoblast and osteoclast activities both directly via cell-to-cell communication and indirectly via secreted factors, and they are the main postnatal source of sclerostin and RANKL (receptor activator of NF-kB ligand), two regulators of osteoblast and osteoclast function. Despite progress in understanding osteocyte biology and function, much remains to be elucidated. Recently developed osteocytic cell lines-together with new genome editing tools-has allowed a closer look at the biology and molecular makeup of these cells. By using single-cell cloning, we identified genes that are associated with high Sost/sclerostin expression and analyzed their regulation and function. Unbiased transcriptome analysis of high- vs. low-Sost/sclerostin-expressing cells identified known and novel genes. Dmp1 (dentin matrix protein 1), Dkk1 (Dickkopf WNT signaling pathway inhibitor 1), and Phex were among the most up-regulated known genes, whereas Srpx2, Cd200, and carbonic anhydrase III (CAIII) were identified as novel markers of differentiated osteocytes. Aspn, Enpp2, Robo2, Nov, and Serpina3g were among the transcripts that were most significantly suppressed in high-Sost cells. Considering that CAII was recently identified as being regulated by Sost/sclerostin and capable of controlling mineral homeostasis, we focused our attention on CAIII. Here, we report that CAIII is highly expressed in osteocytes, is regulated by parathyroid hormone both in vitro and in vivo, and protects osteocytes from oxidative stress.-Shi, C., Uda, Y., Dedic, C., Azab, E., Sun, N., Hussein, A. I., Petty, C. A., Fulzele, K., Mitterberger-Vogt, M. C., Zwerschke, W., Pereira, R., Wang, K., Divieti Pajevic, P. Carbonic anhydrase III protects osteocytes from oxidative stress.


Subject(s)
Carbonic Anhydrase III/metabolism , Osteocytes/metabolism , Oxidative Stress , Adaptor Proteins, Signal Transducing , Animals , Bone Remodeling/genetics , Bone Remodeling/physiology , Carbonic Anhydrase III/genetics , Cell Line , Cell Survival , Glycoproteins/genetics , Glycoproteins/metabolism , Intercellular Signaling Peptides and Proteins , Mice , Osteocytes/cytology , Osteocytes/drug effects , Teriparatide/pharmacology , Transcriptome
12.
Neuroimage ; 159: 46-56, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28732674

ABSTRACT

Recent advances in achieving ultrahigh spatial resolution (e.g. sub-millimeter) diffusion MRI (dMRI) data have proven highly beneficial in characterizing tissue microstructures in organs such as the brain. However, the routine acquisition of in-vivo dMRI data at such high spatial resolutions has been largely prohibited by factors that include prolonged acquisition times, motion induced artifacts, and low SNR. To overcome these limitations, we present here a framework for acquiring and reconstructing 3D multi-slab, multi-band and interleaved multi-shot EPI data, termed 3D-MB-MUSE. Through multi-band excitations, the simultaneous acquisition of multiple 3D slabs enables whole brain dMRI volumes to be acquired in-vivo on a 3 T clinical MRI scanner at high spatial resolution within a reasonably short amount of time. Representing a true 3D model, 3D-MB-MUSE reconstructs an entire 3D multi-band, multi-shot dMRI slab at once while simultaneously accounting for coil sensitivity variations across the slab as well as motion induced artifacts commonly associated with both 3D and multi-shot diffusion imaging. Such a reconstruction fully preserves the SNR advantages of both 3D and multi-shot acquisitions in high resolution dMRI images by removing both motion and aliasing artifacts across multiple dimensions. By enabling ultrahigh resolution dMRI for routine use, the 3D-MB-MUSE framework presented here may prove highly valuable in both clinical and research applications.


Subject(s)
Brain/anatomy & histology , Diffusion Magnetic Resonance Imaging/methods , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Neuroimaging/methods , Algorithms , Humans
13.
Neuroimage ; 118: 667-75, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26072250

ABSTRACT

The advantages of high-resolution diffusion tensor imaging (DTI) have been demonstrated in a recent post-mortem human brain study (Miller et al., NeuroImage 2011;57(1):167-181), showing that white matter fiber tracts can be much more accurately detected in data at a submillimeter isotropic resolution. To our knowledge, in vivo human brain DTI at a submillimeter isotropic resolution has not been routinely achieved yet because of the difficulty in simultaneously achieving high resolution and high signal-to-noise ratio (SNR) in DTI scans. Here we report a 3D multi-slab interleaved EPI acquisition integrated with multiplexed sensitivity encoded (MUSE) reconstruction, to achieve high-quality, high-SNR and submillimeter isotropic resolution (0.85×0.85×0.85mm(3)) in vivo human brain DTI on a 3Tesla clinical MRI scanner. In agreement with the previously reported post-mortem human brain DTI study, our in vivo data show that the structural connectivity networks of human brains can be mapped more accurately and completely with high-resolution DTI as compared with conventional DTI (e.g., 2×2×2mm(3)).


Subject(s)
Brain Mapping/methods , Brain/anatomy & histology , Diffusion Magnetic Resonance Imaging/methods , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Humans , Neural Pathways/anatomy & histology
14.
Brain Connect ; 4(9): 636-40, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25264168

ABSTRACT

Recent emergence of human connectome imaging has led to a high demand on angular and spatial resolutions for diffusion magnetic resonance imaging (MRI). While there have been significant growths in high angular resolution diffusion imaging, the improvement in spatial resolution is still limited due to a number of technical challenges, such as the low signal-to-noise ratio and high motion artifacts. As a result, the benefit of a high spatial resolution in the whole-brain connectome imaging has not been fully evaluated in vivo. In this brief report, the impact of spatial resolution was assessed in a newly acquired whole-brain three-dimensional diffusion tensor imaging data set with an isotropic spatial resolution of 0.85 mm. It was found that the delineation of short cortical association fibers is drastically improved as well as the definition of fiber pathway endings into the gray/white matter boundary-both of which will help construct a more accurate structural map of the human brain connectome.


Subject(s)
Brain Mapping , Brain/anatomy & histology , Connectome , Diffusion Tensor Imaging , Imaging, Three-Dimensional , Nerve Fibers, Myelinated/ultrastructure , Gray Matter/anatomy & histology , Humans , White Matter/anatomy & histology
15.
Virol J ; 11: 7, 2014 Jan 18.
Article in English | MEDLINE | ID: mdl-24438223

ABSTRACT

BACKGROUND: We and others have previously reported that cell membrane-bound TGFß (mTGFß) on activated T regulatory (Treg) cells mediates suppressor function. Current findings suggest that a novel protein known as Glycoprotein A Repetitions Predominant (GARP) anchors mTGFß to the Treg cell surface and facilitates suppressor activity. Recently, we have described that GARP+TGFß+ Treg cells expand during the course of FIV infection. Because Treg cells are anergic and generally exhibit poor proliferative ability, we asked how Treg homeostasis is maintained during the course of feline immunodeficiency virus (FIV) infection. RESULTS: Here, we report that Treg cells from FIV+ cats express GARP and mTGFß and convert T helper (Th) cells into phenotypic and functional Treg cells. Th to Treg conversion was abrogated by anti-TGFß or anti-GARP treatment of Treg cells or by anti-TGFßRII treatment of Th cells, suggesting that Treg cell recruitment from the Th pool is mediated by TGFß/TGFßRII signaling and that cell-surface GARP plays a major role in this process. CONCLUSIONS: These findings suggest Th to Treg conversion may initiate a cascade of events that contributes to the maintenance of virus reservoirs, progressive Th cell immunosuppression, and the development of immunodeficiency, all of which are central to the pathogenesis of AIDS lentivirus infections.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Feline Acquired Immunodeficiency Syndrome/immunology , Immune Tolerance , Immunodeficiency Virus, Feline/immunology , Membrane Proteins/metabolism , T-Lymphocytes, Regulatory/immunology , Transforming Growth Factor beta/metabolism , Animals , CD4-Positive T-Lymphocytes/chemistry , Cats , Interleukin-2 Receptor alpha Subunit/analysis , Signal Transduction , T-Lymphocytes, Regulatory/chemistry
16.
BMC Psychiatry ; 12: 152, 2012 Sep 21.
Article in English | MEDLINE | ID: mdl-22998631

ABSTRACT

BACKGROUND: Studies of individuals who do not meet criteria for major depressive disorder (MDD) but with subclinical levels of depressive symptoms may aid in the identification of neurofunctional abnormalities that possibly precede and predict the development of MDD. The purpose of this study was to evaluate relations between subclinical levels of depressive symptoms and neural activation patterns during tasks previously shown to differentiate individuals with and without MDD. METHODS: Functional magnetic resonance imaging (fMRI) was used to assess neural activations during active emotion regulation, a resting state scan, and reward processing. Participants were twelve females with a range of depressive symptoms who did not meet criteria for MDD. RESULTS: Increased depressive symptom severity predicted (1) decreased left midfrontal gyrus activation during reappraisal of sad stimuli; (2) increased right midfrontal gyrus activation during distraction from sad stimuli; (3) increased functional connectivity between a precuneus seed region and left orbitofrontal cortex during a resting state scan; and (4) increased paracingulate activation during non-win outcomes during a reward-processing task. CONCLUSIONS: These pilot data shed light on relations between subclinical levels of depressive symptoms in the absence of a formal MDD diagnosis and neural activation patterns. Future studies will be needed to test the utility of these activation patterns for predicting MDD onset in at-risk samples.


Subject(s)
Brain/physiopathology , Depression/physiopathology , Emotions/physiology , Adult , Brain Mapping , Female , Functional Neuroimaging , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Nerve Net/physiopathology , Pilot Projects , Severity of Illness Index
17.
Clin Vaccine Immunol ; 19(1): 84-95, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22089246

ABSTRACT

The immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity. In vitro and in vivo assays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 10(11) adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND(50)) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND(50) formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P = 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND(50)) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND(50)) and humoral (0.0005 ND(50)) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.


Subject(s)
Adenoviridae/immunology , Antibodies, Viral/immunology , Antigen-Antibody Complex/immunology , Genetic Vectors , Immunity, Cellular , Immunity, Humoral , Vaccines/immunology , Adenoviridae/genetics , Animals , Antibodies/blood , B-Lymphocytes/immunology , Male , Mice , Mice, Inbred C57BL , T-Lymphocytes/immunology , Transduction, Genetic
18.
Front Hum Neurosci ; 4: 230, 2010.
Article in English | MEDLINE | ID: mdl-21212840

ABSTRACT

During times of emotional stress, individuals often engage in emotion regulation to reduce the experiential and physiological impact of negative emotions. Interestingly, emotion regulation strategies also influence memory encoding of the event. Cognitive reappraisal is associated with enhanced memory while expressive suppression is associated with impaired explicit memory of the emotional event. However, the mechanism by which these emotion regulation strategies affect memory is unclear. We used event-related fMRI to investigate the neural mechanisms that give rise to memory formation during emotion regulation. Twenty-five participants viewed negative pictures while alternately engaging in cognitive reappraisal, expressive suppression, or passive viewing. As part of the subsequent memory design, participants returned to the laboratory two weeks later for a surprise memory test. Behavioral results showed a reduction in negative affect and a retention advantage for reappraised stimuli relative to the other conditions. Imaging results showed that successful encoding during reappraisal was uniquely associated with greater co-activation of the left inferior frontal gyrus, amygdala, and hippocampus, suggesting a possible role for elaborative encoding of negative memories. This study provides neurobehavioral evidence that engaging in cognitive reappraisal is advantageous to both affective and mnemonic processes.

19.
Biol Psychiatry ; 66(9): 886-97, 2009 Nov 01.
Article in English | MEDLINE | ID: mdl-19726030

ABSTRACT

BACKGROUND: Unipolar major depressive disorder (MDD) is characterized by anomalous neurobiological responses to pleasant stimuli, a pattern that may be linked to symptoms of anhedonia. However, the potential for psychotherapy to normalize neurobiological responses to pleasant stimuli has not been evaluated. METHODS: Twelve adults with and 15 adults without MDD participated in two identical functional magnetic resonance imaging scans that used a Wheel of Fortune task. Between scans, MDD outpatients received Behavioral Activation Therapy for Depression, a psychotherapy modality designed to increase engagement with rewarding stimuli and reduce avoidance behaviors. RESULTS: Seventy-five percent of adults with MDD were treatment responders, achieving post-treatment Hamilton Rating Scale for Depression score of six or below. Relative to changes in brain function in the matched nondepressed group, psychotherapy resulted in functional changes in structures that mediate responses to rewards, including the paracingulate gyrus during reward selection, the right caudate nucleus (i.e., the dorsal striatum), during reward anticipation, and the paracingulate and orbital frontal gyri during reward feedback. There was no effect of diagnostic status or psychotherapy on in-scanner task-related behavioral responses. CONCLUSIONS: Behavioral Activation Therapy for Depression, a psychotherapy modality designed to increase engagement with rewarding stimuli and reduce avoidance behaviors, results in improved functioning of unique reward structures during different temporal phases of responses to pleasurable stimuli, including the dorsal striatum during reward anticipation.


Subject(s)
Brain/physiopathology , Depressive Disorder, Major/physiopathology , Psychomotor Performance/physiology , Psychotherapy , Reward , Adult , Brain Mapping , Depressive Disorder, Major/therapy , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged
20.
Neuroimage ; 48(3): 499-500, 2009 Nov 15.
Article in English | MEDLINE | ID: mdl-19616634

ABSTRACT

Here we address the critiques offered by Hasan and Pedraza to our recently published manuscript comparing the performance of two automated segmentation programs, FSL/FIRST and FreeSurfer (Morey R, Petty C, Xu Y, Pannu Hayes J, Wagner H, Lewis D, LaBar K, Styner M, McCarthy G. (2009): A comparison of automated segmentation and manual tracing for quantifying of hippocampal and amygdala volumes. Neuroimage 45:855-866). We provide an assessment and discussion of their specific critiques. Hasan and Pedraza bring up some important points concerning our omission of sample demographic features and inclusion of left and right hemisphere volumes as independent measures in correlational analyses. We present additional data on demographic attributes of our sample and correlations analyzed separately on left and right hemispheres of the amygdala and hippocampus. While their commentary aids the reader to more critically asses our study, it falls short of substantiating that our omissions ought to lead readers to significantly revise their interpretations. Further research will help to disentangle the advantages and limitations of the various freely-available automated segmentation software packages.


Subject(s)
Amygdala/anatomy & histology , Hippocampus/anatomy & histology , Image Processing, Computer-Assisted/methods , Adult , Aging , Automation/methods , Female , Functional Laterality , Humans , Male , Organ Size , Racial Groups , Reproducibility of Results , Software
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