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1.
Biomedicines ; 10(6)2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35740441

ABSTRACT

(1) We hypothesized that adding concurrent stereotactic ablative radiotherapy (SAbR) would increase the time to progression in patients with metastatic castrate-resistant prostate cancer (mCRPCA) treated with sipuleucel-T. (2) Patients with a history of prostate cancer (PC), radiographic evidence of metastatic disease, and rising prostate-specific antigen (PSA) > 0.2 ng/dL on castrate testosterone levels were enrolled in this single-arm phase II clinical trial and treated with sipuleucel-T and SAbR. The primary endpoint was time to progression (TTP). Cellular and humoral responses were measured using ELISpot and Luminex multiplex assays, respectively. (3) Twenty patients with mCRPC were enrolled and treated with SAbR to 1−3 sites. Treatment was well tolerated with 51, 8, and 4 treatment-related grade 1, 2, and 3 toxicities, respectively, and no grade 4 or 5 adverse events. At a median follow-up of 15.5 months, the median TTP was 11.2 weeks (95% CI; 6.8−14.0 weeks). Median OS was 76.8 weeks (95% CI; 41.6−130.8 weeks). This regimen induced both humoral and cellular immune responses. Baseline M-MDSC levels were elevated in mCRPC patients compared to healthy donors (p = 0.004) and a decline in M-MDSC was associated with biochemical response (p = 0.044). Responders had lower baseline uric acid levels (p = 0.05). No clear correlation with radiographic response was observed. (4) While the regimen was safe, the PC-antigen-specific immune response induced by SAbR did not yield a synergistic clinical benefit for patients treated with sipuleucel-T compared to the historically reported outcomes.

2.
J Heart Lung Transplant ; 40(5): 377-386, 2021 05.
Article in English | MEDLINE | ID: mdl-33648871

ABSTRACT

BACKGROUND: Air trapping (AT) is one of the hallmarks of allograft dysfunction after lung transplantation (LT). Inert gas‒based ventilation‒perfusion (VQ) lung scintigraphy has excellent sensitivity in the detection of AT. METHODS: We reviewed the charts of patients who underwent single or double LT between January 2012 and December 2014 (N = 193). Patients without a VQ scintigraphy at the first annual visit (n = 16) and those who did not survive till 1 year (n = 26) were excluded (final n = 151, mean age = 55.8 [SD =14] years, male = 85, female = 66). VQ scintigraphy was independently reviewed and reconciled for the presence and severity of AT by 2 investigators blinded to the clinical data (D.F.P. and D.M.). A 3-year post-transplant survival was the primary end-point. RESULTS: AT was common (n = 73, 48.3%). Patients with obstructive lung diseases as the underlying diagnosis (adjusted odds ratio [OR], 4.36, 95% CI: 1.64‒11.6; p = 0.003) and those with lower body mass index (BMI) (BMI < 25 kg/m2 and 25‒30 kg/m2; p < 0.001) had an increased risk of developing AT in the allograft. The presence of AT (adjusted OR, 2.33, 95% CI: 1.01‒5.36; p = 0.04) and peak forced expiratory volume in 1 sec (FEV1) <60% predicted during the first year after LT were independently associated with 3-year mortality. The association of AT with post-transplant mortality was the strongest among patients with BMI <30 kg/m2 and peak FEV1 <60% predicted. CONCLUSIONS: The finding of AT on VQ scintigraphy at the first annual visit after LT is independently associated with worse post-transplant mortality. The sub-group of patients who fail to achieve a peak FEV1 of 60% predicted during the first year after LT appears to be the key driver of this association.


Subject(s)
Lung Transplantation , Lung/physiopathology , Perfusion/methods , Radionuclide Imaging/methods , Allografts , Female , Follow-Up Studies , Forced Expiratory Volume , Graft Survival , Humans , Lung/diagnostic imaging , Male , Middle Aged , Postoperative Period , Prognosis , Retrospective Studies , Vital Capacity
4.
J Alzheimers Dis ; 71(2): 421-433, 2019.
Article in English | MEDLINE | ID: mdl-31403944

ABSTRACT

BACKGROUND: The current evidence is inconclusive to support the benefits of aerobic exercise training (AET) for preventing neurocognitive decline in patients with amnestic mild cognitive impairment (aMCI). OBJECTIVE: To examine the effect of a progressive, moderate-to-high intensity AET program on memory and executive function, brain volume, and cortical amyloid-ß (Aß) plaque deposition in aMCI patients. METHODS: This is a proof-of-concept trial that randomized 70 aMCI patients to 12 months of AET or stretching and toning (SAT, active control) interventions. Primary neuropsychological outcomes were assessed by using the California Verbal Learning Test-second edition (CVLT-II) and the Delis-Kaplan Executive Function System (D-KEFS). Secondary outcomes were the global and hippocampal brain volumes and the mean cortical and precuneus Aß deposition. RESULTS: Baseline cognitive scores were similar between the groups. Memory and executive function performance improved over time but did not differ between the AET and SAT groups. Brain volume decreased and precuneus Aß plaque deposition increased over time but did not differ between the groups. Cardiorespiratory fitness was significantly improved in the AET compared with SAT group. In amyloid positive patients, AET was associated with reduced hippocampal atrophy when compared with the SAT group. CONCLUSION: The AET and SAT groups both showed evidence of slightly improved neuropsychological scores in previously sedentary aMCI patients. However, these interventions did not prevent brain atrophy or increases in cortical Aß deposition over 12 months. In amyloid positive patients, AET reduced hippocampal atrophy when compared with the SAT group.


Subject(s)
Amnesia/psychology , Amnesia/therapy , Cognitive Dysfunction/psychology , Cognitive Dysfunction/therapy , Exercise/physiology , Exercise/psychology , Aged , Amnesia/diagnostic imaging , Cognitive Dysfunction/diagnostic imaging , Female , Hippocampus/diagnostic imaging , Hippocampus/metabolism , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuropsychological Tests , Positron-Emission Tomography/methods , Single-Blind Method
5.
Transplant Rev (Orlando) ; 33(2): 107-114, 2019 04.
Article in English | MEDLINE | ID: mdl-30415913

ABSTRACT

Lung transplantation is an established treatment for patients with a variety of advanced lung diseases. Imaging studies play a valuable role not only in evaluation of patients prior to lung transplantation, but also in the follow up of patients after transplantation for detection of complications. After lung transplantation, complications can occur as a result of surgical procedure, pulmonary embolism and ultimately chronic lung allograft dysfunction. Lung scintigraphy, which includes physiologic assessment of lung ventilation and perfusion by imaging, has become an important procedure in the evaluation of these patients, assuming a complementary role to high resolution anatomic imaging (computed tomography [CT]), as well as spirometry. The purpose of this atlas article is to demonstrate the uses of ventilation perfusion scintigraphy in the pre-transplantation setting for surgical planning and in the evaluation of complications post-lung transplantation based upon experience at our institution.


Subject(s)
Lung Diseases/diagnostic imaging , Lung Diseases/surgery , Lung Transplantation/methods , Pulmonary Embolism/diagnostic imaging , Ventilation-Perfusion Scan/methods , Female , Humans , Lung Diseases/pathology , Lung Transplantation/adverse effects , Male , Patient Safety , Postoperative Care/methods , Postoperative Complications/diagnostic imaging , Postoperative Complications/physiopathology , Preoperative Care/methods , Pulmonary Embolism/etiology , Severity of Illness Index , Spirometry/methods , Tomography, X-Ray Computed/methods , Treatment Outcome
6.
Case Rep Radiol ; 2017: 9084207, 2017.
Article in English | MEDLINE | ID: mdl-28251012

ABSTRACT

Ectopic thyroid tissue is a rare entity and when discovered it is typically along the pathway of embryologic migration of the thyroid. We present a case of incidental finding of ectopic thyroid tissue within mediastinum in a 61-year-old female patient with a history of total thyroidectomy for thyroiditis and nodules. The patient presented to emergency room with cough and right chest pain and underwent a chest computed tomographic angiogram (CTA) to exclude pulmonary embolism as part of chest pain workup. One right paratracheal mediastinal soft tissue nodule was visualized on the images of CTA. This right paratracheal soft tissue mass was found to be ectopic benign thyroid tissue by histological analysis of the biopsied tissue samples. The function of this ectopic thyroid tissue was characterized by I-123 radioiodine uptake and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. This case illustrates that ectopic thyroid tissue should be included for differential diagnosis of a hyperdense soft tissue mass located within mediastinum. I-123 SPECT/CT is useful for guiding tissue biopsy of ectopic thyroid tissue distant from orthotopic thyroid gland and functional and anatomic characterization of mediastinal ectopic thyroid tissue for surgical resection when it is medically necessary.

9.
J Neurosurg ; 124(6): 1646-53, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26613169

ABSTRACT

Traumatic brain injury (TBI) is a major risk factor for Alzheimer's disease. With respect to amyloid deposition, there are no published serial data regarding the deposition rate of amyloid throughout the brain after TBI. The authors conducted serial (18)F-AV-45 (florbetapir F18) positron emission tomography (PET) imaging in 2 patients with severe TBI at 1, 12, and 24 months after injury. A total of 12 brain regions were surveyed for changes in amyloid levels. Case 1 involved a 50-year-old man who experienced a severe TBI. Compared with the 1-month time point, of the 12 brain regions that were surveyed, a decrease in amyloid (as indicated by standard uptake value ratios) was only observed in the hippocampus (-16%, left; -12%, right) and caudate nucleus (-18%, left; -18%, right), suggesting that initial amyloid accumulation in the brain was cleared between time points 1 and 12 months after injury. Compared to the scan at 1 year, a greater increase in amyloid (+15%) was observed in the right hippocampus at the 24-month time point. The patient in Case 2 was a 37-year-old man who suffered severe trauma to the head and a subsequent stroke; he had poor cognitive/functional outcomes and underwent 1.5 years of rehabilitation. Due to a large infarct area on the injured side of the brain (right side), the authors focused primarily on brain regions affected within the left hemisphere. Compared with the 1-month scan, they only found an increase in brain amyloid within the left anterior putamen (+11%) at 12 months after injury. In contrast, decreased amyloid burden was detected in the left caudate nucleus (-48%), occipital cortex (-21%), and precuneus (-19%) brain regions at the 12-month time point, which is indicative of early accumulation and subsequent clearance. In comparison with 12-month values, more clearance was observed, since a reduction in amyloid was found at 24 months after trauma within the left anterior putamen (-12%) and occipital cortex (-15%). Also, by 24 months, most of the amyloid had been cleared and the patient demonstrated improved results on the Rivermead symptom questionnaire, Glasgow Outcome Scale-Extended, and Disability Rating Scale. With respect to APOE status, the patient in Case 1 had two ε3 alleles and the patient in Case 2 had one ε2 and one ε3 allele. In comparison to the findings of the initial scan at 1 month after TBI, by 12 and 24 months after injury amyloid was cleared in some brain regions and increased in others. Serial imaging conducted here suggests that florbetapir F18 PET imaging may be useful in monitoring amyloid dynamics within specific brain regions following severe TBI and may be predictive of cognitive deficits.


Subject(s)
Amyloid/metabolism , Brain Injuries, Traumatic/diagnostic imaging , Brain Injuries, Traumatic/metabolism , Brain/diagnostic imaging , Brain/metabolism , Adult , Aniline Compounds , Apolipoproteins E/genetics , Brain Injuries, Traumatic/genetics , Ethylene Glycols , Humans , Male , Middle Aged , Positron-Emission Tomography , Radiopharmaceuticals , Severity of Illness Index , Survivors , Time Factors , Tomography, X-Ray Computed
10.
Am J Nucl Med Mol Imaging ; 5(5): 493-503, 2015.
Article in English | MEDLINE | ID: mdl-26550540

ABSTRACT

Bavituximab is a chimeric monoclonal antibody with immune modulating and tumor-associated vascular disrupting properties demonstrated in models of non-small cell lung cancer (NSCLC). The molecular target of Bavituximab, phosphatidylserine (PS), is exposed on the outer leaflet of the membrane bi-layer of malignant vascular endothelial cells and tumor cells to a greater extent than on normal tissues. We evaluated the tumor-targeting properties of Bavituximab for imaging of NSCLC xenografts when radiolabeled with (111)In through conjugation with a bifunctional chelating agent, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). In vitro binding of (111)In-DOTA-Bavituximab to PS was determined by enzyme-linked immunosorbent assay (ELISA). Biodistribution of (111)In-DOTA-Bavituximab was conducted in normal rats, which provided data for dosimetry calculation. Single-photon emission computed tomography/computed tomography (SPECT/CT) imaging was performed in athymic nude rats bearing A549 NSCLC xenografts. At the molar conjugation ratio of 0.54 DOTA per Bavituximab, the PS binding affinity of (111)In-DOTA-Bavituximab was comparable to that of unmodified Bavituximab. Based on the quantitative SPECT/CT imaging data analysis, (111)In-DOTA-Bavituximab demonstrated tumor-specific uptake as measured by the tumor-tomuscle ratio, which peaked at 5.2 at 72 hr post-injection. In contrast, the control antibody only presented a contrast of 1.2 at the same time point.These findings may underlie the diagnostic efficacy and relative low rates of systemic vascular and immune-related toxicities of this immunoconjugate. Future applications of (111)In-DOTA-bavituximab may include prediction of efficacy, indication of tumor immunologic status, or characterization of radiographic findings.

11.
Neurology ; 85(22): 1922-9, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26537049

ABSTRACT

OBJECTIVE: To determine whether cortical ß-amyloid (Aß) deposition is associated with circadian blood pressure (BP) profiles and dynamic cerebral blood flow (CBF) regulation in patients with amnestic mild cognitive impairment (aMCI). METHODS: Forty participants with aMCI were included in this study. Cortical Aß depositions were measured by (18)F-florbetapir PET and expressed as the standardized uptake value ratio (SUVR) relative to the cerebellum. Circadian BP profiles were measured by 24-hour ambulatory monitoring during awake and sleep periods. The dipping status of sleep BP (i.e., the percent changes from the awake BP) was calculated and dichotomized into the dipper (≥10%) and nondipper (<10%) groups. Dynamic CBF regulation was assessed by a transfer function analysis between beat-to-beat changes in BP and CBF velocity measured from the middle cerebral artery during a repeated sit-stand maneuver. RESULTS: Age was positively correlated with a greater Aß deposition in the posterior cingulate, precuneus, and mean cortex. Accounting for the age effect, attenuated reductions in sleep systolic BP were associated with higher levels of posterior cingulate SUVR. Consistently, the nondippers exhibited a higher SUVR in the posterior cingulate than the dippers. Transfer function gain between changes in BP and CBF velocity was diminished in the nondippers, and moreover those individuals with a lower gain exhibited a higher SUVR in the posterior cingulate. CONCLUSIONS: Attenuated reductions in sleep BP are associated with a greater Aß burden in the posterior cingulate and altered dynamic CBF regulation in patients with aMCI.


Subject(s)
Amnesia/physiopathology , Amyloid beta-Peptides/metabolism , Blood Pressure/physiology , Cognitive Dysfunction/physiopathology , Sleep/physiology , Aged , Aged, 80 and over , Amnesia/diagnostic imaging , Amnesia/metabolism , Brain/diagnostic imaging , Brain/metabolism , Circadian Rhythm/physiology , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/metabolism , Female , Humans , Male , Middle Aged , Radionuclide Imaging
12.
Clin Nucl Med ; 40(8): 689-91, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25899588

ABSTRACT

A 30-year-old man had a diagnosis of aggressive carcinoma showing thymuslike differentiation (CASTLE disease) and underwent thyroidectomy for tumor resection and bilateral cervical lymph node dissection. Multiple hypermetabolic nodal metastases were detected in the neck and upper mediastinum with fluorine-18-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography ((18)F-FDG PET/CT). The patient received radiation therapy and chemotherapy for treatment of metastases. Follow-up (18)F-FDG PET/CT demonstrated resolution of several hypermetabolic lesions previously seen in the neck, but innumerable new hypermetabolic metastatic lesions were visualized. The patient died of this aggressive CASTLE disease despite treatment with surgery, radiation, and systemic chemotherapy.


Subject(s)
Carcinoma/diagnostic imaging , Fluorodeoxyglucose F18 , Positron-Emission Tomography , Radiopharmaceuticals , Thyroid Neoplasms/diagnostic imaging , Adult , Carcinoma/pathology , Humans , Lymphatic Metastasis , Male , Multimodal Imaging , Thyroid Neoplasms/pathology , Tomography, X-Ray Computed
13.
Clin Nucl Med ; 38(11): 882-4, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24096999

ABSTRACT

OBJECTIVES: The objectives of this study were to estimate retrospectively the incidence of clinically significant findings in the lower extremities in patients with malignant cutaneous melanoma scanned from the skull vertex to the bottom of the feet and whether these add additional diagnostic and prognostic information and to demonstrate a confidence interval that would support exclusion of lower-extremity scans in these patients. METHODS: This is a retrospective study of 200 patients who underwent (18)F-FDG PET/CT for staging melanoma. Whole-body PET/CT scans including the lower extremities were reviewed. PET/CT findings in the lower extremities were tabulated by location, pathology, and clinical progress notes with documented clinical history and physical examination correlation. RESULTS: Among the 200 PET/CT scans, 3 scans had positive findings in the lower extremities. A biopsy was performed on 1 lesion, which was found to be an incidental squamous cell carcinoma. One lesion was considered a benign finding from inflammation demonstrated by clinical follow-up. One scan had a metastasis to the proximal femur, which is included in the standard FOV (eyes to midthighs). In this case series, the lower extremities' true-positive findings never impacted or changed clinical management. CONCLUSIONS: Our study confirms with a high degree of confidence that in patients with malignant cutaneous melanoma, additional lower-extremity scan results in little additional useful information and could be discontinued in patients whose melanoma did not arise in the lower extremities. PET/CT acquisition of the lower extremities results in increased scan time and unnecessary extra radiation dose from CT to melanoma patients.


Subject(s)
Fluorodeoxyglucose F18 , Melanoma/diagnostic imaging , Positron-Emission Tomography , Tomography, X-Ray Computed , Whole Body Imaging , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Melanoma/pathology , Middle Aged , Neoplasm Staging , Skin Neoplasms , Young Adult , Melanoma, Cutaneous Malignant
14.
Thyroid Res ; 6(1): 7, 2013 May 04.
Article in English | MEDLINE | ID: mdl-23641736

ABSTRACT

Hyperfunctioning nodules of the thyroid are thought to only rarely harbor thyroid cancer, and thus are infrequently biopsied. Here, we present the case of a patient with a hyperfunctioning thyroid nodule harboring thyroid carcinoma and, using MEDLINE literature searches, set out to determine the prevalence of and characteristics of malignant "hot" nodules as a group. Historical, biochemical and radiologic characteristics of the case subjects and their nodules were compared to those in cases of benign hyperfunctioning nodules. A literature review of surgical patients with solitary hyperfunctioning thyroid nodules managed by thyroid resection revealed an estimated 3.1% prevalence of malignancy. A separate literature search uncovered 76 cases of reported malignant hot thyroid nodules, besides the present case. Of these, 78% were female and mean age at time of diagnosis was 47 years. Mean nodule size was 4.13 ± 1.68 cm. Laboratory assessment revealed T3 elevation in 76.5%, T4 elevation in 51.9%, and subclinical hyperthyroidism in 13% of patients. Histological diagnosis was papillary thyroid carcinoma (PTC) in 57.1%, follicular thyroid carcinoma (FTC) in 36.4%, and Hurthle cell carcinoma in 7.8% of patients. Thus, hot thyroid nodules harbor a low but non-trivial rate of malignancy. Compared to individuals with benign hyperfunctioning thyroid nodules, those with malignant hyperfunctioning nodules are younger and more predominantly female. Also, FTC and Hurthle cell carcinoma are found more frequently in hot nodules than in general. We were unable to find any specific characteristics that could be used to distinguish between malignant and benign hot nodules.

16.
NMR Biomed ; 25(11): 1234-44, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22419606

ABSTRACT

Glioblastomas and brain metastases demonstrate avid uptake of 2-[(18) F]fluoro-2-deoxyglucose by positron emission tomography and display perturbations of intracellular metabolite pools by (1) H MRS. These observations suggest that metabolic reprogramming contributes to brain tumor growth in vivo. The Warburg effect, excess metabolism of glucose to lactate in the presence of oxygen, is a hallmark of cancer cells in culture. 2-[(18) F]Fluoro-2-deoxyglucose-positive tumors are assumed to metabolize glucose in a similar manner, with high rates of lactate formation relative to mitochondrial glucose oxidation, but few studies have specifically examined the metabolic fates of glucose in vivo. In particular, the capacity of human brain cancers to oxidize glucose in the tricarboxylic acid cycle is unknown. Here, we studied the metabolism of human brain tumors in situ. [U-(13) C]Glucose (uniformly labeled glucose, i.e. d-glucose labeled with (13) C in all six carbons) was infused during surgical resection, and tumor samples were subsequently subjected to (13) C NMR spectroscopy. The analysis of tumor metabolites revealed lactate production, as expected. We also determined that pyruvate dehydrogenase, turnover of the tricarboxylic acid cycle, anaplerosis and de novo glutamine and glycine synthesis contributed significantly to the ultimate disposition of glucose carbon. Surprisingly, less than 50% of the acetyl-coenzyme A pool was derived from blood-borne glucose, suggesting that additional substrates contribute to tumor bioenergetics. This study illustrates a convenient approach that capitalizes on the high information content of (13) C NMR spectroscopy and enables the analysis of intermediary metabolism in diverse cancers growing in their native microenvironment.


Subject(s)
Brain Neoplasms/metabolism , Glucose/metabolism , Acetyl Coenzyme A/metabolism , Blood Glucose/metabolism , Brain Neoplasms/blood , Brain Neoplasms/secondary , Breast Neoplasms/pathology , Carbon Isotopes , Carcinoma, Non-Small-Cell Lung/pathology , Citric Acid Cycle , Female , Glioblastoma/blood , Glioblastoma/metabolism , Glycine/biosynthesis , Glycolysis , Humans , Oxidation-Reduction
17.
J Neurol ; 257(5): 806-15, 2010 May.
Article in English | MEDLINE | ID: mdl-20033200

ABSTRACT

We wanted to determine the neurocognitive profile of adult patients with moyamoya disease prior to neurosurgical intervention. The experience of three United States medical centers, Columbia University, University of Illinois at Chicago, and the University of Texas Southwestern Medical Center at Dallas, were combined. Clinical data from adult patients (N = 29) referred for neuropsychological evaluation from 1996 to 2008 were reviewed. Neurocognitive functioning was assessed using standardized neuropsychological tests and all data were converted to z-scores. Memory, attention, processing speed, verbal memory, visuo-spatial, language, and executive functions were examined. Cognitive dysfunction was defined as performance in two or more cognitive domains 1.5 standard deviations below age-corrected normative means OR one or more cognitive domains two standard deviations below age-corrected normative means. Manual strength and dexterity, as well as depressive symptoms, were also assessed. Two-thirds of patients demonstrated neurocognitive dysfunction. A large proportion of patients were found to have pronounced cognitive dysfunction (>2 SD below the mean) on tests of processing speed (29%), verbal memory (31%), verbal fluency (26%) and executive function (25%). Manual strength and dexterity were also affected in many patients, with impairment found in 36-58% of patients. Twenty-eight percent of patients reported moderate to severe depression, but depressive symptoms did not correlate with neurocognitive findings. A large proportion of adults with moyamoya disease demonstrate disruption of neurocognition in a broad range of functions, particularly those mediated by subcortical and frontal regions. The pattern of deficits suggests a mechanism of diffuse small vessel disease possibly caused by chronic hypoperfusion.


Subject(s)
Cognition Disorders/complications , Moyamoya Disease/complications , Adult , Aged , Depressive Disorder/complications , Dyskinesias/complications , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Retrospective Studies , United States , Young Adult
18.
Med Sci Sports Exerc ; 41(3): 574-80, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19204594

ABSTRACT

UNLABELLED: Regional cerebral blood flow (rCBF) in the insular cortex (IC), a well-recognized site for central blood pressure (BP) modulation, is decreased at minute 10 during postexercise hypotension (PEH). PURPOSE: To determine whether exercise-induced decreases in IC rCBF are associated with BP changes throughout PEH. METHODS: Ten subjects were studied on three different days using a counterbalanced design with a randomized order for conditions; all were tested during a resting baseline and then at two of three time points postexercise: 10, 30, and 60 min. Data were collected for HR, mean BP, and rCBF using single-photon emission computed tomography as an index of brain activation. RESULTS: Using ANOVA across conditions, there were differences (P < 0.05; mean +/- SD) for HR from baseline at minute 10 (+15 +/- 4 bpm) and minute 30 (+6 +/- 3 bpm) and for mean BP at minute 10 (-11 +/- 4 mm Hg) and minute 30 (-5 +/- 3 mm Hg). There were significant decreases (P < 0.05) in rCBF at both minutes 10 and 30 after exercise in the inferior thalamus and the right inferior IC regions. Although there were no decreases in BP or IC activity at minute 60, changes in right inferior posterior IC activity and BP were strongly correlated (r2 = 0.74; P < 0.05) postexercise. CONCLUSIONS: Findings show that exercise-induced decreases in IC and thalamic activity may be a significant neural factor contributing to at least the first 30 min of PEH.


Subject(s)
Cerebral Cortex/blood supply , Exercise/physiology , Hypotension/physiopathology , Regional Blood Flow/physiology , Adult , Analysis of Variance , Blood Pressure/physiology , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/physiology , Cerebrovascular Circulation/physiology , Female , Heart Rate/physiology , Humans , Male , Positron-Emission Tomography , Random Allocation , Thalamus/blood supply , Thalamus/physiology , Time Factors , Tomography, Emission-Computed, Single-Photon
20.
Med Sci Sports Exerc ; 39(4): 672-9, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17414805

ABSTRACT

UNLABELLED: The insular cortex (IC), a region of the brain involved in blood pressure (BP) modulation, shows decreases in regional cerebral blood flow (rCBF) during postexercise hypotension (PEH). PURPOSE: To determine whether changes in IC neural activity were caused by prior exercise or by changes in BP, this investigation compared patterns of rCBF during periods of hypotension, which was induced by prior exercise (i.e., PEH) and sodium nitroprusside (SNP) infusion and a cold pressor (CP), to restore BP. METHODS: Ten subjects were studied on three different days with randomly assigned conditions: i) resting baseline; ii) PEH; and iii) SNP-induced hypotension (matched to the PEH BP decrease). Data were collected for heart rate (HR) and mean BP, and rCBF was assessed using single-photon emission computed tomography (SPECT) as an index of brain activation. RESULTS: Using ANOVA across conditions, there were differences (P<0.05; mean +/- SD) from baseline during PEH for HR (+12 +/- 3 bpm) and mean BP (-8 +/- 2 mm Hg) and during SNP-induced hypotension (HR = +15 +/- 4 bpm; MBP = -9 +/- 2 mm Hg), with no differences between PEH and SNP. After exercise, there were decreases (P<0.05) in the leg sensorimotor area, anterior cingulate, and the right and left inferior thalamus, right inferior insula, and left anterior insular regions. During SNP-induced hypotension, there were significant increases in the right and left inferior thalamus and the right and left inferior anterior IC. CP during PEH increased BP and IC activity. CONCLUSIONS: Data show that reductions in IC neural activity are not caused by acute BP decreases. Findings suggest that exercise can lead to a temporary decrease in IC neural activity, which may be a significant neural factor contributing to PEH.


Subject(s)
Cerebral Cortex/blood supply , Exercise/physiology , Hypotension , Regional Blood Flow/physiology , Adult , Cerebral Cortex/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Texas
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