Imaging the Retinal Vasculature

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Stephen A. Burns ◽  
Ann E. Elsner ◽  
Thomas J. Gast
Keyword(s):  
Blood Flow ◽  
Measurement Techniques ◽  
Vascular Diseases ◽  
Optical Measurements ◽  
Annual Review ◽  
Retinal Vasculature ◽  
Publication Date ◽  
Noninvasive Measurements ◽  
Vascular Regulation

Advances in retinal imaging are enabling researchers and clinicians to make precise noninvasive measurements of the retinal vasculature in vivo. This includes measurements of capillary blood flow, the regulation of blood flow, and the delivery of oxygen, as well as mapping of perfused blood vessels. These advances promise to revolutionize our understanding of vascular regulation, as well as the management of retinal vascular diseases. This review provides an overview of imaging and optical measurements of the function and structure of the ocular vasculature. We include general characteristics of vascular systems with an emphasis on the eye and its unique status. The functions of vascular systems are discussed, along with physical principles governing flow and its regulation. Vascular measurement techniques based on reflectance and absorption are briefly introduced, emphasizing ways of generating contrast. One of the prime ways to enhance contrast within vessels is to use techniques sensitive to the motion of cells, allowing precise measurements of perfusion and blood velocity. Finally, we provide a brief introduction to retinal vascular diseases. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Abstract 14820: Sirt7 Deficiency in Blood Vessel Components Impairs Vascular Function by Inhibiting Cell Cycle- and Inflammatory-Related Protein Expression

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yuichi Kimura ◽  
Yasuhiro Izumiya ◽  
Satoshi Araki ◽  
Satoru Yamamura ◽  
Yoshiro Onoue ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Vascular Diseases ◽  
Tube Formation ◽  
Hindlimb Ischemia ◽  
Proliferation Assay

Introduction: Aging is a well-established cardiovascular risk factor and associated with vascular dysfunction. Sirt7, one of the members of mammalian sirtuin family, is thought to be involved in age-related diseases. However, little is known about the relative contribution of Sirt7 in vascular dysfunction. Hypothesis: Sirt7 maintains vascular cell functions and its deficiency plays a critical role in vascular diseases. Methods: Sirt7 loss- and gain-of-function experiments were performed with human aortic smooth muscle cells (HAoSMCs) and human umbilical vein endothelial cells (HUVECs). In vivo, blood flow recovery was evaluated by hindlimb ischemia model in homozygous Sirt7 deficient (Sirt7-/-) and wild-type (WT) mice. Irradiated WT mice were intravenously received bone marrow (BM) cells from WT or Sirt7 -/- mouse to achieve BM transfer. Results: An RNAi-medicated Sirt7 knockdown resulted in a significant inhibition of HAoSMCs proliferation following serum or Platelet-derived growth factor BB (PDGF-BB) stimulation as determined by cell count, BrdU cell proliferation assay and MTS proliferation assay. Knockdown of endogenous Sirt7 also reduced cell migration as revealed by Boyden chamber migration assay. The Cyclin D1 and Cyclin dependent kinase 2 (CDK2) protein levels were significantly decreased in Sirt7 siRNA-treated HAoSMCs in response to serum or PDGF-BB stimulation. In endothelial cells, knockdown of Sirt7 attenuated tube formation, proliferation and migration. These changes were accompanied by reduced ERK activation and VCAM-1 mRNA and protein expression in Sirt7 siRNA-treated HUVECs. Conversely, overexpression of Sirt7 by adenovirus enhanced tube formation and cell proliferation. In vivo, blood flow recovery in response to hindlimb ischemia was significantly attenuated in Sirt7-/- mice compared with WT mice. There was no difference in blood flow recovery between WT mice transplanted with WT or Sirt7-/- BM cells suggesting that Sirt7 deficiency in vascular cells have a predominant effect on attenuated blood flow recovery in response to hindlimb ischemia. Conclusions: Sirt7 in blood vessel components have an important role in maintenance of vascular function. Sirt7 could be a promising therapeutic target for vascular diseases.

In Vivo Dynamics of the Latent Reservoir for HIV-1: New Insights and Implications for Cure

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Janet D. Siliciano ◽  
Robert F. Siliciano
Keyword(s):  
Limit Of Detection ◽  
Latent Reservoir ◽  
Annual Review ◽  
Publication Date ◽  
Viral Rebound ◽  
Major Barrier ◽  
Persons Living With Hiv ◽  
Recent Developments ◽  
Hiv 1

Although antiretroviral therapy (ART) can reduce viremia to below the limit of detection and allow persons living with HIV-1 (PLWH) to lead relatively normal lives, viremia rebounds when treatment is interrupted. Rebound reflects viral persistence in a stable latent reservoir in resting CD4+ T cells. This reservoir is now recognized as the major barrier to cure and is the focus of intense international research efforts. Strategies to cure HIV-1 infection include interventions to eliminate this reservoir, to prevent viral rebound from the reservoir, or to enhance immune responses such that viral replication is effectively controlled. Here we consider recent developments in understanding the composition of the reservoir and how it can be measured in clinical studies. We also discuss exciting new insights into the in vivo dynamics of the reservoir and the reasons for its remarkable stability. Finally we discuss recent discoveries on the complex processes that govern viral rebound. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Compositional, Structural, and Kinetic Aspects of Lipid Digestion and Bioavailability: In Vitro, In Vivo, and Modeling Approaches

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Sébastien Marze
Keyword(s):  
Annual Review ◽  
Publication Date ◽  
Lipid Digestion ◽  
Modeling Approaches ◽  
Digestion Kinetics ◽  
Food Design ◽  
Structural Aspects ◽  
Development And Evolution

Lipid digestion and bioavailability are usually investigated separately, using different approaches (in vitro, modeling, in vivo). However, a few inclusive studies show that their kinetics are closely linked. Lipid bioavailability kinetics is likely involved in the development and evolution of several diseases, so lipid digestion kinetics could be involved as well and can be modulated by food design or combination. To illustrate this possibility, the compositional and structural aspects of lipid digestion kinetics, as investigated using in vitro and modeling approaches, are presented first. Then, in vivo and mixed approaches enabling the study of both kinetics are reviewed and discussed. Finally, disparate modeling approaches are introduced, and a unifying modeling scheme is proposed, opening new perspectives for understanding the role and interactions of various factors (chemical, physical, and biological) involved in lipid metabolism. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Physiologically Based Modeling of Food Digestion and Intestinal Microbiota: State of the Art and Future Challenges. An INFOGEST Review

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Steven Le Feunteun ◽  
Ahmed Al-Razaz ◽  
Matthijs Dekker ◽  
Erwin George ◽  
Beatrice Laroche ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Historical Background ◽  
Annual Review ◽  
Publication Date ◽  
Physiologically Based ◽  
The Future ◽  
Future Challenges ◽  
Full Picture ◽  
Food Digestion

This review focuses on modeling methodologies of the gastrointestinal tract during digestion that have adopted a systems-view approach and, more particularly, on physiologically based compartmental models of food digestion and host–diet–microbiota interactions. This type of modeling appears very promising for integrating the complex stream of mechanisms that must be considered and retrieving a full picture of the digestion process from mouth to colon. We may expect these approaches to become more and more accurate in the future and to serve as a useful means of understanding the physicochemical processes occurring in the gastrointestinal tract, interpreting postprandial in vivo data, making relevant predictions, and designing healthier foods. This review intends to provide a scientific and historical background of this field of research, before discussing the future challenges and potential benefits of the establishment of such a model to study and predict food digestion and absorption in humans. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 12 is March 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Nanomechanics of Blood Clot and Thrombus Formation

2022 ◽  
Vol 51 (1) ◽  
Author(s):  
Marco M. Domingues ◽  
Filomena A. Carvalho ◽  
Nuno C. Santos
Keyword(s):  
Mechanical Properties ◽  
Thrombus Formation ◽  
Blood Clot ◽  
Fibrin Clot ◽  
Annual Review ◽  
Publication Date ◽  
New Methods ◽  
Fibrin Network ◽  
Protein Cell

Mechanical properties have been extensively studied in pure elastic or viscous materials; however, most biomaterials possess both physical properties in a viscoelastic component. How the biomechanics of a fibrin clot is related to its composition and the microenvironment where it is formed is not yet fully understood. This review gives an outline of the building mechanisms for blood clot mechanical properties and how they relate to clot function. The formation of a blood clot in health conditions or the formation of a dangerous thrombus go beyond the mere polymerization of fibrinogen into a fibrin network. The complex composition and localization of in vivo fibrin clots demonstrate the interplay between fibrin and/or fibrinogen and blood cells. Studying these protein–cell interactions and clot mechanical properties may represent new methods for the evaluation of cardiovascular diseases (the leading cause of death worldwide), creating new possibilities for clinical diagnosis, prognosis, and therapy. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Intravascular pressure and diameter profile of the utero-ovarian resistance artery network: estrous cycle-dependent modulation of resistance artery tone

2007 ◽  
Vol 293 (5) ◽  
pp. H2937-H2944 ◽  
Author(s):  
Terrence E. Sweeney ◽  
Pooneh Bagher ◽  
Jocelyn Bailey ◽  
Salvatore J. Cherra ◽  
Frank N. Grisafi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Estrous Cycle ◽  
Cycle Phase ◽  
Resistance Artery ◽  
Resistance Arteries ◽  
Vascular Regulation ◽  
Cycle Dependent ◽  
Intravascular Pressure

Blood flow to the ovary varies dramatically in both magnitude and distribution throughout the estrous cycle to meet the hormonal and metabolic demands of the ovarian parenchyma as it cyclically develops and regresses. Several vascular components appear to be critical to vascular regulation of the ovary. As a first step in resolving the role of the resistance arteries and their paired veins in regulating ovarian blood flow and transvascular exchange, we characterized the architecture and intravascular pressure profile of the utero-ovarian resistance artery network in an in vivo preparation of the ovary of the anesthetized Golden hamster. We also investigated estrous cycle-dependent changes in resistance artery tone. The right ovary and the cranial aspect of the uterus in 26 female hamsters were exposed for microcirculatory observations. Estrous-cycle phase was determined in each animal before experimentation. The utero-ovarian vascular architecture was determined and resistance artery diameters were measured in each animal by video microscopy. Servo-null intravascular pressure measurements were made throughout the uteroovarian arterial network in 11 of the animals. Architectural data showed a complex anastomotic network jointly supplying the uterus and ovary. Resistance arteries showed a high degree of coiling and close apposition to veins, maximizing countercurrent-exchange capabilities. Arterial pressure dropped below 60% of systemic arterial pressure before the arteries entered the ovary. Both the ovarian artery and the uterine artery, which jointly feed the ovary, showed cycle day-dependent changes in diameter. Arterial diameters were smallest on the day following ovulation, during the brief luteal phase of the hamster. The data show that resistance arteries comprise a critical part of a complex network designed for intimate local communication and control and suggest that these arteries may play an important role in regulating ovarian blood flow in an estrous cycle-specific manner.

Oxytocin, Neural Plasticity, and Social Behavior

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Robert C. Froemke ◽  
Larry J. Young
Keyword(s):  
Social Behavior ◽  
Neural Plasticity ◽  
Neural Circuit ◽  
Social Behaviors ◽  
Neuron Activity ◽  
Annual Review ◽  
Publication Date ◽  
Social Stimuli ◽  
Circuit Function

Oxytocin regulates parturition, lactation, parental nurturing, and many other social behaviors in both sexes. The circuit mechanisms by which oxytocin modulates social behavior are receiving increasing attention. Here, we review recent studies on oxytocin modulation of neural circuit function and social behavior, largely enabled by new methods of monitoring and manipulating oxytocin or oxytocin receptor neurons in vivo. These studies indicate that oxytocin can enhance the salience of social stimuli and increase signal-to-noise ratios by modulating spiking and synaptic plasticity in the context of circuits and networks. We highlight oxytocin effects on social behavior in nontraditional organisms such as prairie voles and discuss opportunities to enhance the utility of these organisms for studying circuit-level modulation of social behaviors. We then discuss recent insights into oxytocin neuron activity during social interactions. We conclude by discussing some of the major questions and opportunities in the field ahead. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Environmental Toxicology Assays Using Organ-on-Chip

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Patarajarin Akarapipad ◽  
Kattika Kaarj ◽  
Yan Liang ◽  
Jeong-Yeol Yoon
Keyword(s):  
Drug Toxicity ◽  
Environmental Toxicology ◽  
In Vitro Assays ◽  
Annual Review ◽  
Publication Date ◽  
Environmental Toxicants ◽  
Toxicity Screening ◽  
On Chip

Adverse effects of environmental toxicants to human health have traditionally been assayed using in vitro assays. Organ-on-chip (OOC) is a new platform that can bridge the gaps between in vitro assays (or 3D cell culture) and animal tests. Microenvironments, physical and biochemical stimuli, and adequate sensing and biosensing systems can be integrated into OOC devices to better recapitulate the in vivo tissue and organ behavior and metabolism. While OOCs have extensively been studied for drug toxicity screening, their implementation in environmental toxicology assays is minimal and has limitations. In this review, recent attempts of environmental toxicology assays using OOCs, including multiple-organs-on-chip, are summarized and compared with OOC-based drug toxicity screening. Requirements for further improvements are identified and potential solutions are suggested. Expected final online publication date for the Annual Review of Analytical Chemistry, Volume 14 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Magnetic Micro- and Nanoagents for Monitoring Enzymatic Activity In Vivo

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Michael G. Christiansen ◽  
Matej ◽  
Vizovišek ◽  
Simone Schuerle
Keyword(s):  
Enzymatic Activity ◽  
Proteolytic Enzymes ◽  
Point Of Care ◽  
Autonomous Systems ◽  
Annual Review ◽  
Publication Date ◽  
Modular Architectures ◽  
Molecular Substrates ◽  
Enzyme Detection

Enzymes are appealing diagnostic targets because of their centrality in human health and disease. Continuous efforts spanning several decades have yielded methods for magnetically detecting the interactions of enzymes with exogenous molecular substrates. Nevertheless, measuring enzymatic activity in vivo remains challenging due to background noise, insufficient selectivity, and overlapping enzymatic functions. Magnetic micro- and nanoagents are poised to help overcome these issues by offering possible advantages such as site-selective sampling, modular architectures, new forms of magnetic detection, and favorable biocompatibility. Here, we review relevant control and detection strategies and consider examples of magnetic enzyme detection demonstrated with micro- or nanorobotic systems. Most cases have focused on proteolytic enzymes, leaving ample opportunity to expand to other classes of enzymes. Enzyme-responsive magnetic micro- and nanoagents hold promise for lowering barriers of translation and enabling preemptive, point-of-care medical applications. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Organoid Models for Infectious Disease

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Sarah E. Blutt ◽  
Mary K. Estes
Keyword(s):  
Infectious Diseases ◽  
Ex Vivo ◽  
Annual Review ◽  
Publication Date ◽  
Individual Health ◽  
Health Related ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Human Infections

Infectious diseases affect individual health and have widespread societal impacts. New ex vivo models are critical to understand pathogenesis, host response, and features necessary to develop preventive and therapeutic treatments. Pluripotent and tissue stem cell–derived organoids provide new tools for the study of human infections. Organoid models recapitulate many characteristics of in vivo disease and are providing new insights into human respiratory, gastrointestinal, and neuronal host–microbe interactions. Increasing culture complexity by adding the stroma, interorgan communication, and the microbiome will improve the use of organoids as models for infection. Organoid cultures provide a platform with the capability to improve human health related to infectious diseases. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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