
Ananth AnnapragadaTexas Children's Hospital · Department of Pediatric Radiology
Ananth Annapragada
Ph.D.
About
158
Publications
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Introduction
Additional affiliations
June 2011 - present
June 2011 - present
April 2010 - June 2011
Education
January 1985 - April 1989
Publications
Publications (158)
Revascularization plays a critical role in the successful engraftment of transplanted pancreatic islets, which are inherently rich in capillaries to meet their high metabolic demands. Innovative islet encapsulation strategies such as the NICHE (neovascularized implantable cell homing and encapsulation), generate a prevascularized transplantation si...
Familial Alzheimer's disease (AD) involving known AD causing genes accounts for a small fraction of cases, the vast majority are sporadic. Neuroinflammation, secondary to viral infection, has been suggested as an initiating or accelerating factor. In this work we tested the hypothesis that SARS-CoV-2 (SCV2) viral infection accelerates the developme...
Alzheimer's disease is the most common cause of dementia and a leading cause of mortality in the elderly population. Diagnosis of Alzheimer's disease has traditionally relied on evaluation of clinical symptoms for cognitive impairment with a definitive diagnosis requiring post‐mortem demonstration of neuropathology. However, advances in disease pat...
Background
The immune-suppressive tumor microenvironment (TME) of oral cancer often hinders the effectiveness of standard treatments, including surgery, chemoradiotherapy, and immunotherapy. This is true for the highly aggressive MOC2 syngeneic oral cancer cell line, which promotes a ’cold’ immunological landscape that limits the efficacy of checkp...
Immune checkpoint inhibitors (ICI), pembrolizumab and atezolizumab, were recently approved for treatment‐refractory triple‐negative breast cancer (TNBC), where those with Programmed death‐ligand 1 (PD‐L1) positive early‐stage disease had improved responses. ICIs are administered systemically in the clinic, however, reaching effective therapeutic do...
The Immuno-Oncology Translational Network (IOTN) was established in 2018 as part of the Cancer MoonshotSM, and in 2022 President Biden set new goals to reduce the cancer death rate by half within 25 years and improve lives of people with cancer and cancer survivors. The IOTN is focused on accelerating translation of cancer immunology research from...
Introduction: The immunosuppressive tumor microenvironment (TME) in oral cancer inhibits response to conventional treatment (surgery +/- chemoradiotherapy) and check-point inhibitor (αPD1) immunotherapy. The chemotherapeutic agent doxorubicin and its PEGylated liposomal nanoparticle formulation (PLD) have been shown to target myeloid derived suppre...
The first line of treatment for most solid tumors is surgical resection of the primary tumor with adequate negative margins. Incomplete tumor resections with positive margins account for over 75% of local recurrences and the development of distant metastases. In cases of oral cavity squamous cell carcinoma (OSCC), the rate of successful tumor remov...
Introduction
Prior preclinical studies established the utility of liposomal nanoparticle blood-pool contrast agents in visualizing the retroplacental clear space (RPCS), a marker of normal placentation, while sparing fetuses from exposure because the agent does not cross the placental barrier. In this work, we characterized RPCS disruption in a mou...
Introduction
Prior preclinical studies established the utility of liposomal nanoparticle blood-pool contrast agents in visualizing the retroplacental clear space (RPCS), a marker of normal placentation, while sparing fetuses from exposure because the agent does not cross the placental barrier. In this work we characterized RPCS disruption in a mous...
MYCN is a major driver for neuroblastoma (NB) and the tyrosine hydroxylase (TH)-MYCN transgenic mouse model is extensively used for preclinical NB studies. However, spatio-temporal NB progression in the TH-MYCN model has not been studied, and questions remain about the value of implanted models as a surrogate for transgenic mice. In this work, we u...
Background and Purpose
Moyamoya disease (MMD) is a progressive steno-occlusive cerebrovascular disease leading to recurrent stroke. There is a lack of reliable biomarkers to identify unilateral stroke MMD patients who are likely to progress to bilateral disease and experience subsequent contralateral stroke(s). We hypothesized that local hemodynami...
Moyamoya disease (MMD) is characterized by narrowing of the distal internal carotid artery and the circle of Willis (CoW) and leads to recurring ischemic and hemorrhagic stroke. A retrospective review of data from 50 pediatric MMD patients revealed that among the 24 who had a unilateral stroke and were surgically treated, 11 (45.8%) had a subsequen...
The development of imaging agents for in vivo detection of alpha‐synuclein (α‐syn) pathologies faces several challenges. A major gap in the field is the lack of diverse molecular scaffolds with high affinity and selectivity to α‐syn fibrils for in vitro screening assays. Better in vitro scaffolds can instruct the discovery of better in vivo agents....
Objective:
Tumor-associated macrophages (TAMs) within the tumor immune microenvironment (TiME) of solid tumors play an important role in treatment resistance and disease recurrence. The purpose of this study was to investigate if nanoradiomics (radiomic analysis of nanoparticle contrast-enhanced images) can differentiate tumors based on TAM burden...
While a definitive Alzheimer’s disease (AD) diagnosis remains a post-mortem exercise, the ATN Research Framework proposed by the National Institute on Aging and the Alzheimer’s Association utilizes a score representing the presence of amyloid deposits (A), tau deposits (T) and neuronal degeneration markers (N), with A+T+ necessary for a positive di...
Objective
Study the impact of local policies on near-future hospitalization and mortality rates.
Materials and Methods
We introduce a novel risk-stratified SIR-HCD model that introduces new variables to model the dynamics of low-contact (e.g., work from home) and high-contact (e.g., work on-site) subpopulations while sharing parameters to control...
Child physical abuse is a leading cause of traumatic injury and death in children. In 2017, child abuse was responsible for 1688 fatalities in the United States, of 3.5 million children referred to Child Protection Services and 674,000 substantiated victims. While large referral hospitals maintain teams trained in Child Abuse Pediatrics, smaller co...
p>The development of imaging agents for in vivo detection of alpha-synuclein (α-syn) pathologies faces several challenges. A major gap in the field is the lack of diverse molecular scaffolds with high affinity and selectivity to α-syn fibrils for in vitro screening assays. Better in vitro scaffolds can instruct the discovery of better in vivo agent...
Objective
Early detection of aortic degeneration is critical for improving outcomes in patients with aortic aneurysm and dissection. We investigated nanoparticle contrast-enhanced computed tomography for the early detection of aortic injury.
Approach and Results
In a mouse model of sporadic aortic aneurysm and dissection, C57BL/6J mice were challe...
The coronavirus disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome coronavirus disease 2 (SARS CoV-2) most commonly presents with respiratory disease, but neurologic complications are being reported. We aimed to investigate the rate of positive neuroimaging findings in children positive for SARS-CoV-2 referred for neuroima...
Background
Chronic neuroinflammation plays a critical role in the pathophysiology of Alzheimer’s disease (AD) and related dementias. The CNS is immune privileged with restricted peripheral leukocyte traffic under normal physiological conditions. Neuroinflammation in disease brains is often accompanied by BBB compromise and increase CNS infiltration...
Background
Hyperphosphorylated tau (pTau) is a characteristic of AD, leading to intracellular “tau tangles” followed by dementia. However, intracellular tau is difficult to measure in vivo, requiring a probe to enter the cell. Proteomic changes on the diseased cell‐surface however, provide a diagnostic target that eliminates the need for a probe to...
Background
Hyperphosphorylated tau (pTau) is a precursor to tau tangle formation in Alzheimer's disease (AD). We have identified aptamers that bind to specific cell membrane receptors of human neuronal cells that are hyperphosphorylating tau. In this work, we built a novel targeted nanoparticle magnetic resonance imaging (MRI) contrast agent, TauX,...
Background
Early detection of amyloid plaque deposits is crucial for identifying pre‐symptomatic Alzheimer’s disease (AD) patients. An amyloid imaging magnetic resonance imaging (MRI) contrast agent would have substantial utility in the clinic due to its ease of distribution and the standard use of MRI in AD patient workup. In this work, we describ...
In these preclinical studies, we describe ADx-001, an Aβ-targeted liposomal macrocyclic gadolinium (Gd) imaging agent, for MRI of amyloid plaques. The targeting moiety is a novel lipid-PEG conjugated styryl-pyrimidine. An MRI-based contrast agent such as ADx-001 is attractive because of the lack of radioactivity, ease of distribution, long shelf li...
3D-printed nasopharyngeal swabs for COVID-19 molecular diagnostic testing address the national shortage of swabs. Swab designs for adult use were placed in the public domain in March 2020. Swabs for pediatric use, however, need to be smaller and more flexible to navigate delicate pediatric nasopharyngeal cavities. We describe a novel use of maxillo...
Objective: We study the influence of local reopening policies on the composition of the infectious population and their impact on future hospitalization and mortality rates. Materials and Methods: We collected datasets of daily reported hospitalization and cumulative morality of COVID-19 in Houston, Texas, from May 1, 2020 until June 29, 2020. Thes...
Immunotherapies, including cell-based therapies, targeting the tumor microenvironment (TME) result in variable and delayed responses. Thus, it has been difficult to gauge the efficacy of TME-directed therapies early after administration. We investigated a nano-radiomics approach (quantitative analysis of nanoparticle contrast–enhanced three-dimensi...
Despite regulatory approval of several immune-based treatments for cancer in the past decade, a number of barriers remain to be addressed in order to fully harness the therapeutic potential of the immune system and provide benefits for patients with cancer. As part of the Cancer Moonshot initiative, the Immuno-Oncology Translational Network (IOTN)...
Background
Recently developed convolutional neural network (CNN) models determine bone age more accurately than radiologists.
Objective
The purpose of this study was to determine whether a CNN and radiologists can accurately predict bone age from radiographs using only the index finger rather than the whole hand.
Materials and methods
We used a p...
Non-invasive methods for estimating placental fractional blood volume (FBV) are of great interest for characterization of vascular perfusion in placentae during pregnancy to identify placental insufficiency that may be indicative of local ischemia or fetal growth restriction (FGR). Nanoparticle contrast-enhanced magnetic resonance imaging (CE-MRI)...
Introduction:
Visualization of the retroplacental clear space (RPCS) may provide critical insight into the development of abnormally invasive placenta (AIP). In this pre-clinical study, we characterized the appearance of the RPCS on magnetic resonance imaging (MRI) during the second half of gestation using a liposomal gadolinium contrast agent (li...
Purpose:
To determine the feasibility of using deep learning with a multiview approach, similar to how a human radiologist reviews multiple images, for binomial classification of acute pediatric elbow radiographic abnormalities.
Materials and methods:
A total of 21 456 radiographic studies containing 58 817 images of the elbow and associated rad...
Pediatric tibial fractures are commonly diagnosed by radiographs and constitute one of the common tasks performed by pediatric radiologists. Here, we assess the performance of a convolutional neural network for the detection of acute tibial fractures trained with a limited number of cases in skeletally immature patients. This retrospective study wa...
Fluorine-19 ( ¹⁹ F) magnetic resonance imaging (MRI) has the potential for a wide range of in vivo applications but is limited by lack of flexibility in exogenous probe formulation. Most ¹⁹ F MRI probes are composed of perfluorocarbons (PFCs) or perfluoropolyethers (PFPEs) with intrinsic properties which limit formulation options. Hydrophilic organ...
Fluorescence imaging in the second near-infrared window (NIR-II) holds promise for real-time deep tissue imaging. In this work, we investigated the NIR-II fluorescence properties of a liposomal formulation of indocyanine green (ICG), a FDA-approved dye that was recently shown to exhibit NIR-II fluorescence. Fluorescence spectra of liposomal-ICG wer...
Inflammation drives the degradation of atherosclerotic plaque, yet there are no non-invasive techniques available for imaging overall inflammation in atherosclerotic plaques, especially in the coronary arteries. To address this, we have developed a clinically relevant system to image overall inflammatory cell burden in plaque. Here, we describe a t...
Fluorine-19 (19F) Magnetic Resonance Imaging (MRI) is an emerging modality for molecular imaging and cell tracking. The hydrophobicity of current exogenous probes, perfluorocarbons (PFCs) and perfluoropolyethers (PFPEs), limits the formulation options available for in vivo applications. Hydrophilic probes permit more formulation flexibility. Furthe...
Indocyanine green (ICG), a FDA approved near infrared (NIR) fluorescent agent, is used in the clinic for a variety of applications including lymphangiography, intra-operative lymph node identification, tumor imaging, superficial vascular imaging, and marking ischemic tissues. These applications operate in the so-called “NIR-I” window (700–900 nm)....
Absorbance curves for ICG and IR-E1050 in PBS, plasma, and ethanol.
(TIFF)
Representative regions of interest (ROIs) location on tissue phantoms and hind limb images collected with NIR-II camera.
(TIFF)
Comparison of normalized fluorescence intensities for ICG (in plasma and ethanol) and IR-E1050 (in PBS and plasma) for the following fixed emission wavelengths.
(TIFF)
Contrast enhancement of the hind limb in a nude mouse after i.v. tail injection of ICG acquired with NIR-I camera.
(AVI)
Contrast enhancement of the hind limb in a nude mouse after i.v. tail injection of ICG acquired with NIR-II camera.
(AVI)
Introduction:
Non-invasive 3D imaging that enables clear visualization of placental margins is of interest in the accurate diagnosis of placental pathologies. This study investigated if contrast-enhanced MRI performed using a liposomal gadolinium blood-pool contrast agent (liposomal-Gd) enables clear visualization of the placental margins and the...
We developed a technology that allows a simple desktop 3D printer with dual extruder to fabricate 3D flexible models of Major AortoPulmonary Collateral Arteries. The study was designed to assess whether the flexible 3D printed models could help during surgical planning phase. Simple FDM 3D printers are inexpensive, versatile in use and easy to main...
Scientific Reports 6 : Article number: 27863 10.1038/srep27863 ; published online: 14 June 2016 ; updated: 16 February 2017 The original version of this Article contained a typographical error in the spelling of the author Ketan Ghaghada, which was incorrectly given as Ketan Ghagahda.
Mutations in ACTA2 predispose to a spectrum of vascular diseases, including Moyamoya-like cerebrovascular disease (MMD). Acta2 -/- mice show straightening of cerebral arteries, narrowing and occlusions characteristic of MMD. They do not show typical MMD collaterals, but exhibit thick bypasses, perfusing ischemic zones. We found a set of altered mor...
In a rat model of right free wall replacement, the transplantation of an engineered multilayered myocardial patch fabricated from a polycaprolactone membrane supporting a chitosan/heart matrix hydrogel induces significant muscular and vascular remodeling and results in a significantly higher right ventricular ejection fraction compared to use of a...
The degree of tumor removal at surgery is a major factor in predicting outcome for ovarian cancer. A single multimodality agent that can be used with magnetic resonance (MR) for staging and pre-surgical planning, and with optical imaging to aid surgical removal of tumors, would present a new paradigm for ovarian cancer. We assessed whether a dual-m...
Liposomal chemotherapeutics are exemplified by DOXIL(R) are commonly used in adult cancers. While these agents exhibit improved safety profile compared to their free drug counterparts, their treatment response rates have been ~ 20%, often attributed to the heterogeneous intratumoral uptake and distribution of liposomal nanoparticles. Non-invasive a...
Patients with advanced head and neck squamous cell carcinoma receiving chemotherapy have a poor prognosis partly due to normal tissue toxicity; therefore, development of a tumor-targeted drug delivery platform to minimize collateral toxicity is a goal of cancer nanomedicine. Aptamers can achieve this purpose. While conventional Systematic Evolution...
Introduction: Delivery of a nanoparticle payload to a specific cellular compartment is a prized goal of cancer nanomedicine. The well-known SELEX (systematic evolution of ligands by exponential enrichment) process is often used to identify aptamers that localize to target cellular compartments, but such aptamers cannot be guaranteed to traffic an a...
The trans-placental permeability of liposomal Gadolinium (Gd) nanoparticle contrast agents was evaluated in a pregnant mouse model. Pregnant Balb/c mice at 16.5 (±1) days of gestation were imaged using a 3D Spoiled Gradient Echo method at 9.4 T using two contrast agents: a clinically approved Gd chelate, Multihance® (gadobenate dimeglumine), and a...
Amyloid binding molecules with greater hydrophilicity than existing ligands were synthesized. The lead candidate ET6-21 bound amyloid fibrils, and amyloid deposits in dog brain and human brain tissue ex vivo. The ligand was used to prepare novel amyloid-targeted liposomal nanoparticles. The preparation was tested in the Tg2576 and TetO/APP mouse mo...
The scope of this review focuses on recent applications in preclinical and clinical magnetic resonance imaging (MRI) toward accomplishing the goals of early detection and responses to therapy in animal models of Alzheimer's disease (AD). Driven by the outstanding efforts of the Alzheimer's Disease Neuroimaging Initiative (ADNI), a truly invaluable...
Mass transport within an organ occurs through networks of blood vessels and surrounding tissue. This convective-diffusive transport is a very complex process which spans several different scales, from nano- to micro- to macro-scale. The blood vessel network is usually very intricate and irregular with respect to size and geometry, with mass transpo...