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Dive into the research topics where Jason M. Johnson is active.

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Featured researches published by Jason M. Johnson.


Journal of Gastrointestinal Surgery | 2005

Effects of gastric bypass procedures on bone mineral density, calcium, parathyroid hormone, and vitamin d

Jason M. Johnson; James W. Maher; Isaac Samuel; Deborah Heitshusen; Cornelius Doherty; Robert W. Downs

Weight loss after gastric bypass procedures has been well studied, but the long-term metabolic sequelae are not known. Data on bone mineral density (BMD), calcium, parathyroid hormone, and vitamin D were collected preoperatively and at yearly intervals after gastric bypass procedures. A total of 230 patients underwent preoperative BMD scans. Fifteen patients were osteopenic preoperatively, and three patients subsequently developed osteopenia postoperatively within the first year. No patient had or developed osteoporosis. At 1 year, total forearm BMD decreased by 0.55% (n = 91; P = .03) and radius BMD had increased overall by 1.85% (n = 23; P = .008); both total hip and lumbar spine BMD decreased by 9.27% (n = 22; P < .001) and 4.53% (n = 31; P < .001), respectively. By the second postoperative year, BMD in the total forearm had decreased an additional 3.62% (n = 14; P<.001), whereas radius BMD remained unchanged. Although total hip and lumbar spine BMD significantly decreased at 1 year, by year 2 both total hip and lumbar spine BMD only slightly decreased and were not significantly different from before the operation. Serum calcium decreased from 9.8 mg/dL to 9.2 during the first year (not significant [NS]) and then to 8.8 (NS) by the second year. Parathyroid hormone increased from 59.7 pg/mL (nl 10-65 pg/mL) preoperatively to 63.1 during year 1 (NS) and continued to increase to 64.7 by year 2 (NS). No difference was noted among levels of 25-hydroxy vitamin D preoperatively (25.2 ng/mL; nl 10-65 ng/mL), at 1 year (34.4), and at 2 years (35.4). Our data indicate that bone loss is highest in the first year after gastric bypass with stabilization, and that, in some cases, there is an increase in bone density after the first year.


Annals of Surgery | 2006

The Long-term Effects of Gastric Bypass on Vitamin D Metabolism

Jason M. Johnson; James W. Maher; Eric J. DeMaria; Robert W. Downs; Luke G. Wolfe; John M. Kellum

Objective:Alterations of the endocrine system in patients following Roux-en-Y gastric bypass (GBP) are poorly described and have prompted us to perform a longitudinal study of the effects of GBP on serum calcium, 25-hydroxy-vitamin-D (vitamin D), and parathyroid hormone (PTH). Methods:Prospectively collected data were compiled to determine how GBP affects serum calcium, vitamin D, and PTH. Student t test, Fisher exact test, or linear regression was used to determine significance. Results:Calcium, vitamin D, and PTH levels were drawn on 243 patients following GBP. Forty-one patients had long-limb bypass (LL-GBP), Roux >100 cm, and 202 had short-limb bypass (SL-GBP), Roux ≤100 cm. The mean (±SD) postoperative follow-up time was significantly longer in the LL-GBP group (5.7 ± 2.5 years) than the SL-GBP group (3.1 ± 3.6 years, P < 0.0001). When corrected for albumin levels, mean calcium was 9.3 mg/dL (range, 8.5–10.8 mg/dL), and no difference existed between LL-GBP and SL-GBP patients. For patients with low vitamin D levels (<8.9 ng/mL), 88.9% had elevated PTH (>65 pg/mL) and 58.0% of patients with normal vitamin D levels (≥8.9 ng/mL) had elevated PTH (P < 0.0001). In individuals with vitamin D levels <30 ng/mL, 55.1% (n = 103) had elevated PTH, and of those with vitamin D levels ≥30 ng/mL 28.5% (n = 16) had elevated PTH (P = 0.0007). Mean vitamin D levels were lower in patients who had undergone LL-GBP as opposed to those with SL-GBP, 16.8 ± 10.8 ng/mL versus 22.7 ± 11.1 ng/mL (P = 0.0022), and PTH was significantly higher in patients who had a LL-GBP (113.5 ± 88.0 pg/mL versus 74.5 ± 52.7 pg/mL, P = 0.0002). There was a linear decrease in vitamin D (P = 0.005) coupled with a linear increase in PTH (P < 0.0001) the longer patients were followed after GBP. Alkaline phosphatase levels were elevated in 40.3% of patients and correlated with PTH levels. Conclusion:Vitamin D deficiency and elevated PTH are common following GBP and progress over time. There is a significant incidence of secondary hyperparathyroidism in short-limb GBP patients, even those with vitamin D levels ≥30 ng/mL, suggesting selective Ca2+ malabsorption. Thus, calcium malabsorption is inherent to gastric bypass. Careful calcium and vitamin D supplementation and long-term screening are necessary to prevent deficiencies and the sequelae of secondary hyperparathyroidism.


PLOS ONE | 2009

ACC2 Is Expressed at High Levels Human White Adipose and Has an Isoform with a Novel N-Terminus

John Castle; Yoshikazu Hara; Christopher K. Raymond; Philip W. Garrett-engele; Kenji Ohwaki; Zhengyan Kan; Jun Kusunoki; Jason M. Johnson

Acetyl-CoA carboxylases ACC1 and ACC2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA, regulating fatty-acid synthesis and oxidation, and are potential targets for treatment of metabolic syndrome. Expression of ACC1 in rodent lipogenic tissues and ACC2 in rodent oxidative tissues, coupled with the predicted localization of ACC2 to the mitochondrial membrane, have suggested separate functional roles for ACC1 in lipogenesis and ACC2 in fatty acid oxidation. We find, however, that human adipose tissue, unlike rodent adipose, expresses more ACC2 mRNA relative to the oxidative tissues muscle and heart. Human adipose, along with human liver, expresses more ACC2 than ACC1. Using RT-PCR, real-time PCR, and immunoprecipitation we report a novel isoform of ACC2 (ACC2.v2) that is expressed at significant levels in human adipose. The protein generated by this isoform has enzymatic activity, is endogenously expressed in adipose, and lacks the N-terminal sequence. Both ACC2 isoforms are capable of de novo lipogenesis, suggesting that ACC2, in addition to ACC1, may play a role in lipogenesis. The results demonstrate a significant difference in ACC expression between human and rodents, which may introduce difficulties for the use of rodent models for development of ACC inhibitors.


Neuroradiology | 2013

The neuroanatomical phenotype of tuberous sclerosis complex: focus on radial migration lines

Agnies M. van Eeghen; Laura Ortiz Terán; Jason M. Johnson; Margaret B. Pulsifer; Elizabeth A. Thiele; Paul A. Caruso

IntroductionThe contribution of radial migration lines (RMLs) to the neuroanatomical and neurocognitive phenotype of tuberous sclerosis complex (TSC) is unclear. The aim of this study was to perform a comprehensive evaluation of the neuroradiological phenotype of TSC, distinguishing RMLs from normal-appearing white matter (NAWM) using diffusion tensor imaging (DTI) and volumetric fluid-attenuated inversion recovery imaging.MethodsMagnetic resonance images of 30 patients with TSC were evaluated. The frequencies of RMLs, tubers, and subependymal nodules (SENs) were determined for every hemispheric lobe. Cerebellar lesions and subependymal giant cell tumors were counted. DTI metrics were obtained from the NAWM of every hemispheric lobe and from the largest RML and tuber. Analyses of variance and correlations were performed to investigate the associations between neuroanatomical characteristics and relationships between RML frequency and neurocognitive outcomes. NAWM DTI metrics were compared with measurements of 16 control patients.ResultsA mean of 47 RMLs, 27 tubers, and 10 SENs were found per patient, and the frequencies of these lesions were strongly correlated (p < 0.001). RML fractional anisotropy and mean diffusivity were strongly inversely correlated (p = 0.003). NAWM DTI metrics were similar to the controls (p = 0.26). RML frequency was strongly associated with age of seizure onset (p = 0.003), intelligence outcomes (p = 0.01), and level of autistic features (p = 0.007).ConclusionA detailed neuroradiological phenotype is presented, showing that RMLs are the most frequent neuroanatomical lesion, are responsible for white matter DTI abnormalities, and are strongly associated with age of seizure onset, intelligence outcomes, and level of autistic features.


American Journal of Medical Genetics Part A | 2005

Auriculo-condylar syndrome is associated with highly variable ear and mandibular defects in multiple kindreds.

Andrea L. Storm; Jason M. Johnson; Edward J. Lammer; Glenn E. Green; Christopher Cunniff

We report on 20 individuals in 4 kindreds with auriculo‐condylar syndrome (ACS), an autosomal dominant disorder characterized by congenital auricular clefts, mandibular condyle hypoplasia, temporomandibular joint (TMJ) abnormalities, micrognathia, microstomia, and a round facial appearance with prominent cheeks. Affected individuals have varying degrees of glossoptosis, respiratory distress, masticatory abnormalities, and malocclusion. Data from these families and those previously described suggest that this is a unique disorder with widely variable expression, including lack of obvious external anomalies in some individuals and severe ear malformations, condyle agenesis, and characteristic facial features in others. Early recognition of this condition should permit appropriate counseling and anticipatory guidance, including evaluation for reconstructive surgery and orthodontia and intervention for upper airway obstruction and sleep apnea.


Neuroimaging Clinics of North America | 2013

The Use of Magnetic Resonance Spectroscopy in the Evaluation of Epilepsy

Paul A. Caruso; Jason M. Johnson; Ronald L. Thibert; Otto Rapalino; Sandra Rincon; Eva-Maria Ratai

Magnetic resonance spectroscopy (MRS) is indicated in the imaging protocol of the patient with epilepsy to screen for metabolic derangements such as inborn errors of metabolism and to characterize masses that may be equivocal on conventional magnetic resonance imaging for dysplasia versus neoplasia. Single-voxel MRS with echo time of 35 milliseconds may be used for this purpose as a quick screening tool in the epilepsy imaging protocol. MRS is useful in the evaluation of both focal and generalized epilepsy.


Surgery for Obesity and Related Diseases | 2016

ASMBS position statement on alcohol use before and after bariatric surgery

Manish Parikh; Jason M. Johnson; Naveen Ballem

ASMBS Guidelines/Statements ASMBS position statement on alcohol use before and after bariatric surgery Manish Parikh, M.D.*, Jason M. Johnson, D.O., Naveen Ballem, M.D., on behalf of the American Society for Metabolic and Bariatric Surgery Clinical Issues Committee Department of Surgery, New York University Medical Center/Bellevue Hospital Center, New York, New York Department of General Surgery, Spartanburg Regional Healthcare System, Spartanburg, South Carolina Center for Advanced Surgical Weight Loss, Montclair, New Jersey Received October 29, 2015; accepted October 29, 2015


Radiology | 2015

Breast Cancer Detection with Short-Interval Follow-up Compared with Return to Annual Screening in Patients with Benign Stereotactic or US-guided Breast Biopsy Results

Jason M. Johnson; Alisa K. Johnson; Ellen S. O'Meara; Diana L. Miglioretti; Berta M. Geller; Elise N. Hotaling; Sally D. Herschorn

PURPOSE To compare the cancer detection rate and stage after benign stereotactic or ultrasonography (US)-guided core breast biopsy between patients with short-interval follow-up (SIFU) and those who return to annual screening. MATERIALS AND METHODS The Breast Cancer Surveillance Consortium (BCSC) registry and the BCSC Statistical Coordinating Center received institutional review board approval for active and passive consent processes and a waiver of consent. All procedures were HIPAA compliant. BCSC data for 1994-2010 were used to compare ipsilateral breast cancer detection rates and tumor characteristics for diagnoses within 3 months after SIFU (3-8 months) versus return to annual screening (RTAS) mammography (9-18 months) after receiving a benign pathology result from image-guided breast biopsy. RESULTS In total, 17 631 biopsies with benign findings were identified with SIFU or RTAS imaging. In the SIFU group, 27 ipsilateral breast cancers were diagnosed in 10 715 mammographic examinations (2.5 cancers per 1000 examinations) compared with 16 cancers in 6916 mammographic examinations in the RTAS group (2.3 cancers per 1000 examinations) (P = .88). Sixteen cancers after SIFU (59%; 95% confidence interval [CI]: 39%, 78%) were invasive versus 12 after RTAS (75%; 95% CI: 48%, 93%). The invasive cancer rate was 1.5 per 1000 examinations after SIFU (95% CI: 0.9, 2.4) and 1.7 per 1000 examinations (95% CI: 0.9, 3.0) after RTAS (P = .70). Among invasive cancers, 25% were late stage (stage 2B, 3, or 4) in the SIFU group (95% CI: 7%, 52%) versus 27% in the RTAS group (95% CI: 6%, 61%). Positive lymph nodes were found in seven (44%; 95% CI: 20%, 70%) invasive cancers after SIFU and in three (25%; 95% CI: 5%, 57%) invasive cancers after RTAS. CONCLUSION Similar rates of cancer detection were found between SIFU and RTAS after benign breast biopsy with no significant differences in stage, tumor size, or nodal status, although the present study was limited by sample size. These findings suggest that patients with benign radiologic-pathologic-concordant percutaneous breast biopsy results could return to annual screening.


Pediatric Radiology | 2010

Ultrasonographic detection of intracranial melanocytosis in an infant

Jason M. Johnson; L. Leigh Patten; Caroline D. Robson; Rita L. Teele

An infant who had an extensive cutaneous melanotic nevus with satellite lesions had cranial US for an unrelated problem. Small spherical echogenic foci in the cerebral and cerebellar parenchyma were identified. Subsequent MRI confirmed these as characteristic of melanotic deposits, thereby identifying this infant as having neurocutaneous melanosis.


Surgery for Obesity and Related Diseases | 2018

American Society for Metabolic and Bariatric Surgery Review of the Literature on One-Anastomosis Gastric Bypass

Manish Parikh; Dan Eisenberg; Jason M. Johnson; Maher ElChaar

The following review is being published by the American Society for Metabolic and Bariatric Surgery in response to numerous inquiries made to the Society by patients, physicians, society members, hospitals, and others regarding one-anastomosis gastric bypass as a primary treatment for obesity or metabolic disease. The review is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The review is not intended as, and should not be construed as, stating or establishing a local, regional, or national standard of care.

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James W. Maher

Virginia Commonwealth University

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