2015
A novel biopsy method to increase yield of subcutaneous abdominal adipose tissue Journal Article
In: Int J Obes (Lond), vol. 39, no. 1, pp. 183–186, 2015.
Abstract | BibTeX | Tags: methods
@article{pmid24849392,
title = {A novel biopsy method to increase yield of subcutaneous abdominal adipose tissue},
year = {2015},
date = {2015-01-01},
journal = {Int J Obes (Lond)},
volume = {39},
number = {1},
pages = {183--186},
abstract = {Collection of abdominal subcutaneous adipose tissue (SAT) for research testing is traditionally performed using punch biopsy or needle aspiration techniques, yielding small amounts of very superficial SAT (100-500 mg). Although liposuction techniques can be used to obtain large amounts of SAT, these approaches can compromise the integrity of the adipose tissue. Therefore, we investigated a novel method using a 6-mm Bergström side-cutting biopsy needle to acquire suitable amounts of intact abdominal SAT for multiple complex studies such as flow cytometry, RNA extraction, ex vivo expression of molecular and post-translational protein mediators, and histology. Fifty biopsies were obtained from 29 participants using a Bergström biopsy needle, applying transient manual suction and shearing large pieces of fat within the inner-cutting trochar. Eighteen of the biopsies were performed under ultrasound guidance, whereby we successfully sampled deep SAT (dSAT) from below Scarpa's fascia. The average weight of SAT sampled was 1.5 ± 0.4 g. There was no clinically important bleeding or ecchymosis on the abdominal wall and no infection occurred with this procedure. The 6-mm Bergström biopsy needle yielded substantially more SAT than what has been obtained from superficial procedures and, for the first time, allowed sampling of dSAT by a percutaneous approach.},
keywords = {methods},
pubstate = {published},
tppubtype = {article}
}
2013
Kim, J Y; Goran, M I; Toledo-Corral, C M; Weigensberg, M J; Choi, M; Shaibi, G Q
One-hour glucose during an oral glucose challenge prospectively predicts β-cell deterioration and prediabetes in obese Hispanic youth Journal Article
In: Diabetes Care, vol. 36, no. 6, pp. 1681–1686, 2013.
Abstract | BibTeX | Tags: diabetes risk, methods
@article{pmid23315601,
title = {One-hour glucose during an oral glucose challenge prospectively predicts β-cell deterioration and prediabetes in obese Hispanic youth},
author = {J Y Kim and M I Goran and C M Toledo-Corral and M J Weigensberg and M Choi and G Q Shaibi},
year = {2013},
date = {2013-06-01},
journal = {Diabetes Care},
volume = {36},
number = {6},
pages = {1681--1686},
abstract = {In adults, 1-h glucose during an oral glucose tolerance test (OGTT) predicts the development of type 2 diabetes independent of fasting and 2-h glucose concentrations. The purpose of the current investigation was to examine the utility of elevated 1-h glucose levels to prospectively predict deterioration in β-cell function and the development of prediabetes in high-risk youth. Obese Latino youth with a family history of type 2 diabetes (133 male and 100 female; age 11.1 ± 1.7 years) completed a baseline OGTT and were divided into two groups based upon a 1-h glucose threshold of 155 mg/dL (<155 mg/dL},
keywords = {diabetes risk, methods},
pubstate = {published},
tppubtype = {article}
}
Joshi, A A; Hu, H H; Leahy, R M; Goran, M I; Nayak, K S
Automatic intra-subject registration-based segmentation of abdominal fat from water-fat MRI Journal Article
In: J Magn Reson Imaging, vol. 37, no. 2, pp. 423–430, 2013.
Abstract | BibTeX | Tags: methods
@article{pmid23011805,
title = {Automatic intra-subject registration-based segmentation of abdominal fat from water-fat MRI},
author = {A A Joshi and H H Hu and R M Leahy and M I Goran and K S Nayak},
year = {2013},
date = {2013-02-01},
journal = {J Magn Reson Imaging},
volume = {37},
number = {2},
pages = {423--430},
abstract = {To develop an automatic registration-based segmentation algorithm for measuring abdominal adipose tissue depot volumes and organ fat fraction content from three-dimensional (3D) water-fat MRI data, and to evaluate its performance against manual segmentation. Data were obtained from 11 subjects at two time points with intermediate repositioning, and from four subjects before and after a meal with repositioning. Imaging was performed on a 3 Tesla MRI, using the IDEAL chemical-shift water-fat pulse sequence. Adipose tissue (subcutaneous--SAT, visceral--VAT) and organs (liver, pancreas) were manually segmented twice for each scan by a single trained observer. Automated segmentations of each subject's second scan were generated using a nonrigid volume registration algorithm for water-fat MRI images that used a b-spline basis for deformation and minimized image dissimilarity after the deformation. Manual and automated segmentations were compared using Dice coefficients and linear regression of SAT and VAT volumes, organ volumes, and hepatic and pancreatic fat fractions (HFF, PFF). Manual segmentations from the 11 repositioned subjects exhibited strong repeatability and set performance benchmarks. The average Dice coefficients were 0.9747 (SAT), 0.9424 (VAT), 0.9404 (liver), and 0.8205 (pancreas); the linear correlation coefficients were 0.9994 (SAT volume), 0.9974 (VAT volume), 0.9885 (liver volume), 0.9782 (pancreas volume), 0.9996 (HFF), and 0.9660 (PFF). When comparing manual and automated segmentations, the average Dice coefficients were 0.9043 (SAT volume), 0.8235 (VAT), 0.8942 (liver), and 0.7168 (pancreas); the linear correlation coefficients were 0.9493 (SAT volume), 0.9982 (VAT volume), 0.9326 (liver volume), 0.8876 (pancreas volume), 0.9972 (HFF), and 0.8617 (PFF). In the four pre- and post-prandial subjects, the Dice coefficients were 0.9024 (SAT), 0.7781 (VAT), 0.8799 (liver), and 0.5179 (pancreas); the linear correlation coefficients were 0.9889, 0.9902 (SAT, and VAT volume), 0.9523 (liver volume), 0.8760 (pancreas volume), 0.9991 (HFF), and 0.6338 (PFF). Automated intra-subject registration-based segmentation is potentially suitable for the quantification of abdominal and organ fat and achieves comparable quantitative endpoints with respect to manual segmentation.},
keywords = {methods},
pubstate = {published},
tppubtype = {article}
}
2011
Shaibi, G Q; Davis, J N; Weigensberg, M J; Goran, M I
Improving insulin resistance in obese youth: choose your measures wisely Journal Article
In: Int J Pediatr Obes, vol. 6, no. 2-2, pp. e290–296, 2011.
Abstract | BibTeX | Tags: methods
@article{pmid21070095,
title = {Improving insulin resistance in obese youth: choose your measures wisely},
author = {G Q Shaibi and J N Davis and M J Weigensberg and M I Goran},
year = {2011},
date = {2011-06-01},
journal = {Int J Pediatr Obes},
volume = {6},
number = {2-2},
pages = {e290--296},
abstract = {The purpose of this investigation was to compare the homeostasis model assessment of insulin resistance (HOMA-IR) to more direct measures of insulin action before and after lifestyle interventions in obese Latino youth. Eleven obese Latino boys (age 15.1 ± 1.6 years, body mass index (BMI) percentile 97.3 ± 3.5%) and twenty obese Latina girls (age 14.7 ± 1.8 years, BMI percentile 96.6 ± 3.6%) participated in two distinct lifestyle interventions. Boys participated in a 16-week exercise intervention and girls participated in a 12-week nutrition education program. Insulin sensitivity was determined by the frequently sampled intravenous glucose tolerance test (FSIVGTT) in boys and by a 3-hour oral glucose tolerance test with multiple sampling calculations for the whole-body insulin sensitivity index (WBISI) in girls. HOMA-IR was measured for both groups. HOMA-IR was correlated at baseline to the FSIVGTT (r = -0.57},
keywords = {methods},
pubstate = {published},
tppubtype = {article}
}