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473 matching studies

Condition of Interest
Swallowing Impairments in Adults With and Without Alzheimer's Disease
Alzheimer Disease Caregiver Burden Healthy Aging Dysphagia
This research study is investigating whether people with Alzheimer's disease (AD) experience more changes to swallowing than their healthy age-matched peers. The prevalence of swallowing impairments in moderate-severe AD is high (85-93%), yet little is known about how swallow function evolves throu1 expand

This research study is investigating whether people with Alzheimer's disease (AD) experience more changes to swallowing than their healthy age-matched peers. The prevalence of swallowing impairments in moderate-severe AD is high (85-93%), yet little is known about how swallow function evolves throughout the disease course in people with AD. The overall objective of this study is to evaluate swallowing function in adults with and without Alzheimer's disease. The investigator will also be involving the primary caregivers of individuals with Alzheimer's that are enrolled in the study to better understand the impact of swallowing impairments on the primary caregivers of those with Alzheimer's Disease. Healthy adults and individuals with Alzheimer's disease will: - undergo tests of cough and swallow function - undergo tests of grip and tongue strength - complete questionnaires Caregivers of individuals with Alzheimer's disease will also complete questionnaires.

Type: Observational

Start Date: Apr 2025

open study

Alzheimer's Disease Neuroimaging Initiative 4
Mild Cognitive Impairment Alzheimer Disease Dementia
Since its launch in 2004, the overarching aim of the Alzheimer's Disease Neuroimaging Initiative (ADNI) Study has been to validate biomarkers for Alzheimer's disease (AD) clinical trials. ADNI4 continues the previously funded ADNI1, ADNI-GO, ADNI2, and ADNI3 studies that have combined public/privat1 expand

Since its launch in 2004, the overarching aim of the Alzheimer's Disease Neuroimaging Initiative (ADNI) Study has been to validate biomarkers for Alzheimer's disease (AD) clinical trials. ADNI4 continues the previously funded ADNI1, ADNI-GO, ADNI2, and ADNI3 studies that have combined public/private collaborations between academia and industry to determine the relationships between the clinical, cognitive, imaging, genetic and biochemical biomarker characteristics of the entire spectrum of AD.

Type: Observational

Start Date: Jun 2023

open study

2-HOBA Phase 2 Clinical Trial in Rheumatoid Arthritis
Rheumatoid Arthritis
This is a phase 2 study to determine 2-HOBA's tolerability, safety, and effect on isoLG-adducts in patients with rheumatoid arthritis (RA) patients. Up to 32 subjects will be randomized to 750mg 2-HOBA or matching placebo three times a day for 4 weeks. As primary outcome measures investigators wil1 expand

This is a phase 2 study to determine 2-HOBA's tolerability, safety, and effect on isoLG-adducts in patients with rheumatoid arthritis (RA) patients. Up to 32 subjects will be randomized to 750mg 2-HOBA or matching placebo three times a day for 4 weeks. As primary outcome measures investigators will compare tolerability and adverse events and changes in isoLG adducts in active and placebo arms. Among prespecified exploratory outcomes investigators will compare changes in markers of inflammation, DAS28 score, and 24-hour blood pressure in active and placebo arms. This pilot study will inform the feasibility and design of future studies to examine the efficacy of 2-HOBA in RA patients.

Type: Interventional

Start Date: Aug 2022

open study

Effect of PDE5 Inhibition on Adipose Metabolism in Humans
Obesity
This is a randomized, double-blinded, placebo-controlled study of the effects of PDE5 inhibition with tadalafil on adipose tissue in obese individuals. Adipose metabolism will be measured using magnetic resonance imaging (MRI) scans and by aspirating a small amount of adipose to measure gene expres1 expand

This is a randomized, double-blinded, placebo-controlled study of the effects of PDE5 inhibition with tadalafil on adipose tissue in obese individuals. Adipose metabolism will be measured using magnetic resonance imaging (MRI) scans and by aspirating a small amount of adipose to measure gene expression.

Type: Interventional

Start Date: Mar 2021

open study

Assessment of the Ocular Microbiome in Health and Disease
Microbial Colonization Eye Diseases Ophthalmopathy
The objective of this application is to illustrate the core constituents of the ocular surface microbiome, describe factors that promote colonization, and assess the ocular microbiome's role in the health of the anterior segment. We will conduct a prospective, observational cohort study, including1 expand

The objective of this application is to illustrate the core constituents of the ocular surface microbiome, describe factors that promote colonization, and assess the ocular microbiome's role in the health of the anterior segment. We will conduct a prospective, observational cohort study, including a longitudinal analysis of the ocular microbiome in adults.

Type: Observational

Start Date: Sep 2023

open study

Stereotactic Radiosurgery for Essential Tremor and Parkinsonian Tremor
Tremor Essential Tremor Parkinson Disease Radiosurgery Quality of Life
The purpose of this study is to determine the changes in quality of life and degree of tremor for patients with essential tremor or Parkinsonian tremor who are treated by stereotactic radiosurgery (SRS). This is a questionnaire-based study. Please see Detailed Description below for more information. expand

The purpose of this study is to determine the changes in quality of life and degree of tremor for patients with essential tremor or Parkinsonian tremor who are treated by stereotactic radiosurgery (SRS). This is a questionnaire-based study. Please see Detailed Description below for more information.

Type: Observational

Start Date: Feb 2013

open study

Cognitive Enhancement in Depression (The COG-D Study)
Aging Depression Cognitive Symptom
This study will investigate whether transcranial direct current stimulation (tDCS) enhances the effects of computerized cognitive training in older adults with recurrent depression (2 or more lifetime episodes; either current or within past 3 years). expand

This study will investigate whether transcranial direct current stimulation (tDCS) enhances the effects of computerized cognitive training in older adults with recurrent depression (2 or more lifetime episodes; either current or within past 3 years).

Type: Interventional

Start Date: Feb 2023

open study

Imaging Sodium and Lymphatics in Lymphedema
Lymphedema of Leg Lymphedema, Secondary Lymphedema Related Fibrosis
Recent evidence supports lymphatic regulation of tissue sodium handling, however fundamental gaps persist in knowledge regarding the role of lymphatics in human diseases of sodium dysregulation. The goal of this work is to apply novel, noninvasive imaging tools to measure relationships between lymp1 expand

Recent evidence supports lymphatic regulation of tissue sodium handling, however fundamental gaps persist in knowledge regarding the role of lymphatics in human diseases of sodium dysregulation. The goal of this work is to apply novel, noninvasive imaging tools to measure relationships between lymphatic function and tissue sodium in patients with well-characterized lymphedema. Findings are intended to inform mechanisms of lymphatic clearance of tissue sodium, and provide novel imaging biomarkers of lymphedema progression and treatment response.

Type: Observational

Start Date: Oct 2021

open study

Memantine for the Treatment of Cognitive Impairment in Systemic Lupus Erythematosus
Lupus Erythematosus, Systemic
A phenome-wide association study (PheWAS) identified an association between a variant in the human gene for the N2A subunit of the N-methyl-D-aspartate (NMDA) receptor, GRIN2A, and Systemic Lupus Erythematosus (SLE). A single nucleotide polymorphism (SNP) in this gene encodes for increased NMDA rec1 expand

A phenome-wide association study (PheWAS) identified an association between a variant in the human gene for the N2A subunit of the N-methyl-D-aspartate (NMDA) receptor, GRIN2A, and Systemic Lupus Erythematosus (SLE). A single nucleotide polymorphism (SNP) in this gene encodes for increased NMDA receptor activity. Based on the potential function of the associated SNP and published literature, alterations in SNP function signaling may underlie a cluster of symptoms. The objective of this study is to evaluate the safety, tolerability and efficacy of memantine, an NMDA receptor antagonist, in a precise patient subset with SLE. Participants will complete a full 14-week clinical trial, receiving either memantine or a placebo. Participants' blood will be drawn to test for various antibodies as well as organ function. Patients' urine will also be collected to assess organ function and pregnancy for females at a number of specific time points. The overall goal is to develop a safe and inexpensive therapeutic approach to reduce debilitating cognitive symptoms in a precisely selected SLE sub-population.

Type: Interventional

Start Date: Aug 2018

open study

A Study to Evaluate Avacopan in Participants With ANCA-associated Vasculitis
Antineutrophil Cytoplasmic Antibody-associated Vasculitis
The primary objective of this study is to evaluate the long-term safety of avacopan in participants with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). expand

The primary objective of this study is to evaluate the long-term safety of avacopan in participants with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Type: Interventional

Start Date: Feb 2024

open study

Sensory Symptoms in Tourette Syndrome
Tourette Syndrome
Patients with tics will be asked to complete a series of validated questionnaires (in electronic and/or paper format) regarding symptoms and conditions often associated with Tourette syndrome, including premonitory urges, sensory experiences, inattention, obsessive-compulsive tendencies, anxiety, a1 expand

Patients with tics will be asked to complete a series of validated questionnaires (in electronic and/or paper format) regarding symptoms and conditions often associated with Tourette syndrome, including premonitory urges, sensory experiences, inattention, obsessive-compulsive tendencies, anxiety, and depression. Participants will also be asked to complete a quality of life assessment. This series of questionnaires will be administered annually.

Type: Observational

Start Date: Apr 2019

open study

MOdification Of THe Early-Life Respiratory Microbiome Through Vaginal SEEDing
C-section Vaginal Seeding Respiratory Microbiome
This is a single-center, parallel-arm, blind, sham-controlled, feasibility randomized controlled trial (RCT) to be conducted in healthy cesarean-born children. Eligible children will be randomized 1:1 to have their nose swabbed with either maternal vaginal secretions or a sterile swab (intervention1 expand

This is a single-center, parallel-arm, blind, sham-controlled, feasibility randomized controlled trial (RCT) to be conducted in healthy cesarean-born children. Eligible children will be randomized 1:1 to have their nose swabbed with either maternal vaginal secretions or a sterile swab (intervention vs. control group, respectively). The main hypothesis is that conducting an RCT assessing the utility of vaginal seeding in modifying the early-life upper respiratory tract (URT) microbiome of children born by C-section is feasible and that the intervention is safe.

Type: Interventional

Start Date: Nov 2022

open study

Trial-Ready Cohort-Down Syndrome (TRC-DS)
Down Syndrome Alzheimer Disease Dementia
The purpose of the Trial-Ready Cohort - Down Syndrome (TRC-DS) is to enroll 120 healthy adults with Down syndrome (DS), between the ages of 25-55, into a trial ready cohort (TRC), and up to 450 participants in total including co-enrolled in the Alzheimer Biomarkers Consortium - Down Syndrome (ABC-D1 expand

The purpose of the Trial-Ready Cohort - Down Syndrome (TRC-DS) is to enroll 120 healthy adults with Down syndrome (DS), between the ages of 25-55, into a trial ready cohort (TRC), and up to 450 participants in total including co-enrolled in the Alzheimer Biomarkers Consortium - Down Syndrome (ABC-DS) study. Participants enrolled in the TRC-DS will undergo longitudinal cognitive and clinical assessment, genetic and biomarker testing, as well as imaging and biospecimen collection. Using these outcome measures, researchers will analyze the relationships between cognitive measures and biomarkers of Alzheimer's disease (AD) to identify endpoints for AD clinical trials in DS that best reflect disease progression. To learn more about the study and participating sites, visit our study website at: https://www.trcds.org/. TRC-DS is collaborating with the Alzheimer's Disease Biomarker Consortium-Down Syndrome (ABC-DS) to allow study participants to be concurrently enrolled in both ABC-DS and TRC-DS, referred to as "co-enrollment". ABC-DS is a longitudinal, observational research study that is overseen at University of Pittsburgh Coordinating Center. ABC-DS participants who express interest in potentially joining a clinical trial in the future and who meet TRC-DS eligibility criteria, may choose to co-enroll in TRC-DS at an ABC-DS Site. Co-enrolled participants will adhere to the ABC-DS protocol and schedule of activities, but agree to share their data with the TRC-DS team and to receive invitations for future participation in clinical trials. Fore more information on ABC-DS please visit https://www.nia.nih.gov/research/abc-ds or http://abcds.pitt.edu/.

Type: Observational

Start Date: Jun 2021

open study

Interventions for Reading Disabilities in NF1
Neurofibromatosis Type 1 Learning Disability Reading Disability NF1
Neurofibromatosis Type 1 (NF1) is a common genetic disorder that is associated with a four times greater risk of learning disabilities, including reading disabilities, and a deficiency of neurofibromin - a protein important in a signaling pathway that regulates learning and memory. Our previous wor1 expand

Neurofibromatosis Type 1 (NF1) is a common genetic disorder that is associated with a four times greater risk of learning disabilities, including reading disabilities, and a deficiency of neurofibromin - a protein important in a signaling pathway that regulates learning and memory. Our previous work (NS49096) demonstrated that school-age children with NF+RD can respond to standard phonologically-based reading tutoring originally developed to treat reading disability in the general population. Combining our work with that by other researchers suggesting that a medication (Lovastatin) may counteract the effects of the deficient neurofibromin, and possibly ameliorate learning disabilities in NF1, the investigator propose to examine the synergistic effects of medication plus reading tutoring.

Type: Interventional

Start Date: Nov 2016

open study

Sympathetic Mechanisms in Obesity-Crossover Design
Obesity Hypertension
We will study obese hypertensive subjects in a randomized, crossover study to determine if two weeks sympathetic blockade improves endogenous glucose production. Subjects will be studied on 3 different occasions after two weeks of receiving either placebo, amlodipine (vasodilator arm) or moxonidine1 expand

We will study obese hypertensive subjects in a randomized, crossover study to determine if two weeks sympathetic blockade improves endogenous glucose production. Subjects will be studied on 3 different occasions after two weeks of receiving either placebo, amlodipine (vasodilator arm) or moxonidine (study arm). The order of the studies will be determined using computer-generated randomization. Patients will be blinded as to which treatment they are receiving on each day. An investigator blinded to the treatment assignment will perform the analysis of the data.

Type: Interventional

Start Date: May 2022

open study

Glucagon-Like Peptide-1 Receptor Agonist in the Treatment of Adult, Obesity-related, Symptomatic As1
Asthma
This is a randomized placebo-controlled trial of semaglutide, an FDA-approved therapy for the treatment of type 2 diabetes mellitus and obesity, in adults with symptomatic asthma despite the use of inhaled steroids and with excess body weight. This study will test the central hypothesis that semagl1 expand

This is a randomized placebo-controlled trial of semaglutide, an FDA-approved therapy for the treatment of type 2 diabetes mellitus and obesity, in adults with symptomatic asthma despite the use of inhaled steroids and with excess body weight. This study will test the central hypothesis that semaglutide will improve asthma control and reduce airway inflammation due to direct effects on the respiratory tract in adult asthma associated with obesity.

Type: Interventional

Start Date: Oct 2022

open study

PROGRESS: Management of Moderate Aortic Stenosis by Clinical Surveillance or TAVR
Aortic Stenosis, Calcific Aortic Valve Stenosis
This study objective is to establish the safety and effectiveness of the Edwards SAPIEN 3 / SAPIEN 3 Ultra / SAPIEN 3 Ultra RESILIA Transcatheter Heart Valve systems in subjects with moderate, calcific aortic stenosis. Following completion of enrollment, subjects will be eligible for enrollment in1 expand

This study objective is to establish the safety and effectiveness of the Edwards SAPIEN 3 / SAPIEN 3 Ultra / SAPIEN 3 Ultra RESILIA Transcatheter Heart Valve systems in subjects with moderate, calcific aortic stenosis. Following completion of enrollment, subjects will be eligible for enrollment in the continued access phase of the trial.

Type: Interventional

Start Date: Oct 2021

open study

Enhancing Parasympathetic Activity to Improve Endothelial Dysfunction, Vascular Oxidative Stress in1
Endothelial Dysfunction
Specific Aim 1: To test the hypothesis that prolonged (3-month) treatment with galantamine inhibits NADPH IsoLG-protein adducts formation and improves markers of endothelial cell (EC) dysfunction in AAs. Aim 1a: The investigators will determine if galantamine inhibits NADPH IsoLG-protein adducts f1 expand

Specific Aim 1: To test the hypothesis that prolonged (3-month) treatment with galantamine inhibits NADPH IsoLG-protein adducts formation and improves markers of endothelial cell (EC) dysfunction in AAs. Aim 1a: The investigators will determine if galantamine inhibits NADPH IsoLG-protein adducts formation, superoxide production, and immune cell activation compared to placebo. For this purpose, the investigators will study peripheral blood mononuclear cell (PBMC), a critical source of systemic oxidative stress, collected from study participants. Aim 1b: The investigators will determine if galantamine reduces intracellular Iso-LGs, ICAM-1, and 3-nitrotyrosine, a marker of vascular oxidative stress, in ECs harvested from study participants. Specific Aim 2: To determine if prolonged (3-month) treatment with galantamine improves endothelial dysfunction as measured by vascular reactivity in AAs. The investigators will measure vascular reactivity in response to ischemia in two vascular beds: (a) in conduit arteries (brachial artery) using brachial artery diameter flow-mediated dilation (FMD), and (b) in the microvasculature (MBV) using contrast-enhanced ultrasonography in skeletal muscle. Sub-study (optional) Will study the effect of trans-auricular vagus nerve stimulation (TaVNS) during a period of enhanced vascular oxidative stress This proposal will study a novel mechanism that could alter the oxidative and immunogenic responses that contributes to endothelial dysfunction in AAs and will offer a potential pathway for the development of more effective therapies aimed at decreasing the progression of endothelial dysfunction to cardiovascular disease in this population.

Type: Interventional

Start Date: Dec 2021

open study

Pain Type and Interstitial Cystitis/Bladder Pain Syndrome Treatment
Chronic Interstitial Cystitis Bladder Pain Syndrome Painful Bladder Syndrome Cystitis, Interstitial Cystitis, Chronic Interstitial
Interstitial cystitis/bladder pain syndrome (IC/BPS) is a severe pain condition affecting 3-8 million people in the United States lacking treatments that work. Emotional suffering is common in IC/BPS and known to make physical symptoms worse, and studies show patient sub-groups respond differently1 expand

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a severe pain condition affecting 3-8 million people in the United States lacking treatments that work. Emotional suffering is common in IC/BPS and known to make physical symptoms worse, and studies show patient sub-groups respond differently to treatment. Individuals with IC/BPS have distinct subgroups, or "phenotypes," largely characterized by the distribution of pain throughout the body. Supported by our preliminary evidence, the overall goal of this project is to assess how IC/BPS phenotype may affect response to two different therapies often given without regard to patient phenotype, pelvic floor physical therapy (PT) and cognitive-behavioral therapy (CBT) for IC/BPS.

Type: Interventional

Start Date: May 2024

open study

Sensorimotor and Psychosocial Trajectories in Adolescents with Tic Disorder
Tourette Syndrome Tic Disorder
Individuals with tic disorders have lower quality of life, sensory and movement difficulties, and poorer mental, social, and physical health compared to the general population. Current clinical care for individuals with tic disorders is limited: no interventions are proven to prevent or stop the di1 expand

Individuals with tic disorders have lower quality of life, sensory and movement difficulties, and poorer mental, social, and physical health compared to the general population. Current clinical care for individuals with tic disorders is limited: no interventions are proven to prevent or stop the disorder exist, and most treatments focus solely on tics, though other symptoms often affect quality of life more than tics. To develop new treatments and improve care for people with tics, researchers need to better understand the different symptoms people experience and how the brain causes these symptoms. Many individuals with tic disorders have sensory and movement symptoms other than tics. A common sensory symptom is increased sensitivity to common sensations, such as glare from sunlight, tags in shirt collars, and noises from passing cars. A common movement symptom is poor handwriting and/or poor coordination. In one study of adolescents with tic disorder, difficulty with hand coordination predicted tic severity 7.5 years later, suggesting that sensory and/or motor difficulties may be a risk factor for more severe tics later in life. Despite how common they are, much is unknown about sensory and motor difficulties experienced by people with tic disorders. Additionally, most studies of people with tics enroll younger children. As a result, little is known about sensory, motor, and psychosocial development in adolescents with tics. Knowledge of sensory and motor difficulties in adolescents with tics is important to understand because, in other adolescent populations, such difficulties are associated with worse mental and social health and worse quality of life. Deepening insight into the sensory, motor, and psychosocial development of adolescents with tic disorders is crucial to identify causes and risk factors for poor health in this population. The goals of this study are to measure sensory and motor symptoms and function in adolescents with tics and to compare them to adolescents without tics. The research team will enroll adolescents with tics and adolescents without tics to participate in the study. Adolescent participants will complete questionnaires, electroencephalogram (EEG) tasks, and other sensory and motor tasks at baseline (with 2 study visits occurring within 30 days of each other) and 2 years later (again, with 2 study visits, occurring within 30 days of each other). A parent or other adult who knows the adolescent well will also complete questionnaires as part of the study.

Type: Observational

Start Date: Oct 2024

open study

Stress and Opioid Misuse Risk: The Role of Endogenous Opioid and Endocannabinoid Mechanisms
Opioid Use Disorder Back Pain Stress
The purpose of this study is to see how stress influences the effects of opioid pain medications often used to help relieve back pain. The study will help to learn more about how high stress levels could increase risk for pain medication misuse. expand

The purpose of this study is to see how stress influences the effects of opioid pain medications often used to help relieve back pain. The study will help to learn more about how high stress levels could increase risk for pain medication misuse.

Type: Interventional

Start Date: Mar 2022

open study

CBT Enhanced With Social Cognitive Training vs. CBT Only With Depressed Youth
Depression
Depression in youth is a serious public health concern for which more personalized treatments are needed. This randomized controlled trial will test the effect of an intervention aimed at enhancing social cognitive capacities (e.g., ability to take another's perspective), thereby making treatment o1 expand

Depression in youth is a serious public health concern for which more personalized treatments are needed. This randomized controlled trial will test the effect of an intervention aimed at enhancing social cognitive capacities (e.g., ability to take another's perspective), thereby making treatment of depression in youth more efficient and effective. Participants in the R33 (N=82) will be youth between ages 13- through 17-years-old currently experiencing depression. Youth will be randomized to either an enhanced CBT intervention that teaches social cognitive skills, particularly social perspective taking and theory of mind (CBTSCT) as compared to CBT only. The primary target is improvement in both social cognitive skills and depressive symptoms at post-treatment and at a 6-month follow-up.

Type: Interventional

Start Date: Oct 2022

open study

Cardiovascular Autonomic and Immune Mechanism of Post COVID-19 Tachycardia Syndrome
Post-acute COVID-19 Syndrome Postural Tachycardia Syndrome (POTS) Long COVID SARS CoV 2 Infection
The term post-acute COVID-19 syndrome or Long COVID is a disabling syndrome that persists beyond the 3-month convalescence period after COVID-19 infections. This syndrome affects mostly women (~80%), present with chronic tachycardia and Orthostatic intolerance symptoms without any identifiable cau1 expand

The term post-acute COVID-19 syndrome or Long COVID is a disabling syndrome that persists beyond the 3-month convalescence period after COVID-19 infections. This syndrome affects mostly women (~80%), present with chronic tachycardia and Orthostatic intolerance symptoms without any identifiable cause. In addition, non-specific symptoms such as fatigue, headache, and "brain fog", commonly described in POTS patients are also present in this novel condition, recently named post-COVID-19 tachycardia syndrome, POTS variant. Reduced Vagal activity and unresolved inflammation is post-COVID-19 POTS is hypothesized as the cause of Long COVID

Type: Interventional

Start Date: Jun 2022

open study

Splanchnic Venous Capacitance in Postural Tachycardia Syndrome
Postural Tachycardia Syndrome (POTS)
Postural tachycardia syndrome (POTS) affects ≈3 million young people, characterized by chronic presyncopal symptoms characterized by dizziness, lightheadedness, and orthostatic tachycardia that occur while standing. Across-sectional survey found that 25% of these patients complains that meals rich1 expand

Postural tachycardia syndrome (POTS) affects ≈3 million young people, characterized by chronic presyncopal symptoms characterized by dizziness, lightheadedness, and orthostatic tachycardia that occur while standing. Across-sectional survey found that 25% of these patients complains that meals rich in carbohydrates are among the factors that further exacerbate POTS's symptoms and cause a myriad of gastrointestinal symptoms. The splanchnic circulation is the largest blood volume reservoir of the human body, storing ≈25% of the total blood volume and contributing to sudden, and large, fluctuations in the stroke volume (SV). The orthostatic changes in systemic hemodynamics are particularly magnified after meals, due to increased blood volume sequestration triggered by the release of gastrointestinal peptides with vasodilatory properties. The purpose of this study is to determine if the worsening orthostatic tachycardia and symptoms after glucose ingestion in POTS patients are due to a greater increase in splanchnic venous capacitance and excessive blood pooling on standing as compare to Healthy controls. The study will also determine if glucose-induced GIP secretion increases splanchnic venous capacitance, orthostatic tachycardia and worsening POTS postprandial symptoms. For this purpose subjects will be further randomized to either saline versus GIP(3-30)NH2 acute infusion, to measure the changes their splanchnic venous capacitance and superior mesenteric arterial flow before and after a 75-g oral glucose challenge during supine and 45-degree head-up tilt positions (orthostatic challenge) for up to 3 hours.

Type: Interventional

Start Date: Feb 2023

open study

Dopaminergic Dysfunction in Late-Life Depression
Late Life Depression Cognitive Decline Depressive Disorder, Treatment-Resistant Levodopa Gait Impairment
Late-Life Depression (LLD), or depression in older adults, often presents with motivational deficits, deficits in performance in cognitive domains including processing speed and executive dysfunction, and mobility impairments. This triad of findings implicate dopaminergic dysfunction as a core path1 expand

Late-Life Depression (LLD), or depression in older adults, often presents with motivational deficits, deficits in performance in cognitive domains including processing speed and executive dysfunction, and mobility impairments. This triad of findings implicate dopaminergic dysfunction as a core pathophysiologic feature in depression, and may contribute to cognitive decline and motor disability. Normal aging results in brain-wide dopamine declines, decreased D1/D2 receptor density, and loss of dopamine transporters. Although brain changes associated with depression and aging converge on dopamine circuits, the specific disturbances in LLD and how responsive the system is to modulation remain unclear. In this study, investigators are testing integrative model that aging, in concert with pro-inflammatory shifts, decreases dopamine signaling. These signally changes affects behaviors supported by these circuits, in the context of age-associated cortical atrophy and ischemic microvascular changes, resulting in variable LLD phenotypes. Investigators propose a primary pathway where dopaminergic dysfunction in depressed elders contributes to slowed processing speed and mobility impairments that increase the effort cost associated with voluntary behavior. The central hypothesis of this study is that late-life depression is characterized by dysfunction in the dopamine system and, by enhancing dopamine functioning in the brain. By improving cognitive and motor slowing, administration of carbidopa/levodopa (L-DOPA) will improve depressive symptoms.

Type: Interventional

Start Date: Feb 2021

open study