2815 Edgewood Rd Sw
Cedar Rapids IA 52404
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Detecting gas-induced vasomotor changes via blood oxygenation level-dependent contrast in healthy breast parenchyma and breast carcinoma. - Journal of magnetic resonance imaging : JMRI
To evaluate blood oxygenation level-dependent (BOLD) contrast changes in healthy breast parenchyma and breast carcinoma during administration of vasoactive gas stimuli.Magnetic resonance imaging (MRI) was performed at 3T in 19 healthy premenopausal female volunteers using a single-shot fast spin echo sequence to acquire dynamic T2 -weighted images. 2% (n = 9) and 5% (n = 10) carbogen gas mixtures were interleaved with either medical air or oxygen in 2-minute blocks, for four complete cycles. A 12-minute medical air breathing period was used to determine background physiological modulation. Pixel-wise correlation analysis was applied to evaluate response to the stimuli in breast parenchyma and these results were compared to the all-air control. The relative BOLD effect size was compared between two groups of volunteers scanned in different phases of the menstrual cycle. The optimal stimulus design was evaluated in five breast cancer patients.Of the four stimulus combinations tested, oxygen vs. 5% carbogen produced a response that was significantly stronger (P < 0.05) than air-only breathing in volunteers. Subjects imaged during the follicular phase of their cycle when estrogen levels typically peak exhibited a significantly smaller BOLD response (P = 0.01). Results in malignant tissue were variable, with three out of five lesions exhibiting a diminished response to the gas stimulus.Oxygen vs. 5% carbogen is the most robust stimulus for inducing BOLD contrast, consistent with the opposing vasomotor effects of these two gases. Measurements may be confounded by background physiological fluctuations and menstrual cycle changes. J. Magn. Reson. Imaging 2015.Â© 2016 The Authors Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
Quantitative BOLD imaging at 3T: Temporal changes in hepatocellular carcinoma and fibrosis following oxygen challenge. - Journal of magnetic resonance imaging : JMRI
To evaluate the utility of oxygen challenge and report on temporal changes in blood oxygenation level-dependent (BOLD) contrast in normal liver, hepatocellular carcinoma (HCC) and background fibrosis.Eleven volunteers (nine male and two female, mean age 33.5, range 27-41 years) and 10 patients (nine male and one female, mean age 68.9, range 56-87 years) with hepatocellular carcinoma on a background of diffuse liver disease were recruited. Imaging was performed on a 3T system using a multiphase, multiecho, fast gradient echo sequence. Oxygen was administered via a Hudson mask after 2 minutes of free-breathing. Paired t-tests were performed to determine if the mean pre- and post-O2 differences were statistically significant.In patients with liver fibrosis (nâ€‰=â€‰8) the change in T2* following O2 administration was elevated (0.88â€‰Â±â€‰0.582 msec, range 0.03-1.69 msec) and the difference was significant (Pâ€‰=â€‰0.004). The magnitude of the BOLD response in patients with HCC (nâ€‰=â€‰10) was larger, however the response was more variable (1.07â€‰Â±â€‰1.458 msec, range -0.93-3.26 msec), and the difference was borderline significant (Pâ€‰=â€‰0.046). The BOLD response in the volunteer cohort was not significant (Pâ€‰=â€‰0.121, 0.59â€‰Â±â€‰1.162 msec, range -0.81-2.44 msec).This work demonstrates that the BOLD response following oxygen challenge within cirrhotic liver is consistent with a breakdown in vascular autoregulatory mechanisms. Similarly, the elevated BOLD response within HCC is consistent with the abnormal capillary vasculature within tumors and the arterialization of the blood supply. Our results suggest that oxygen challenge may prove a viable BOLD contrast mechanism in the liver. J. Magn. Reson. Imaging 2016.Â© 2016 The Authors Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
Mass Spectrometry-based Metabolomics Identifies Longitudinal Urinary Metabolite Profiles Predictive of Radiation-induced Cancer. - Cancer research
Non-lethal exposure to ionizing radiation (IR) is a public concern due to its known carcinogenic effects. Although latency periods for IR-induced neoplasms are relatively long, the ability to detect cancer as early as possible is highly advantageous for effective therapeutic intervention. Therefore, we hypothesized that metabolites in the urine from mice exposed to total body radiation (TBI) would predict for the presence of cancer before a palpable mass was detected. In this study, we exposed mice to 0 or 5.4 Gy TBI, collected urine samples periodically over one year, and assayed urine metabolites by using mass spectrometry. Longitudinal data analysis within the first year post-TBI revealed that cancers, including hematopoietic, solid, and benign neoplasms, could be distinguished by unique urinary signatures as early as 3 months post-TBI. Furthermore, a distinction among different types of malignancies could be clearly delineated as early as 3 months post-TBI for hematopoietic neoplasms, 6 months for solid neoplasms, and by 1 year for benign neoplasms. Moreover, the feature profile for radiation-exposed mice 6 months post-TBI was found to be similar to non-irradiated control mice at 18 months, suggesting that TBI accelerates aging. These results demonstrate that urine feature profiles following TBI can identify cancers prior to macroscopic detection, with important implications for the early diagnosis and treatment.Copyright Â© 2016, American Association for Cancer Research.
Reversing methanogenesis to capture methane for liquid biofuel precursors. - Microbial cell factories
Energy from remote methane reserves is transformative; however, unintended release of this potent greenhouse gas makes it imperative to convert methane efficiently into more readily transported biofuels. No pure microbial culture that grows on methane anaerobically has been isolated, despite that methane capture through anaerobic processes is more efficient than aerobic ones.Here we engineered the archaeal methanogen Methanosarcina acetivorans to grow anaerobically on methane as a pure culture and to convert methane into the biofuel precursor acetate. To capture methane, we cloned the enzyme methyl-coenzyme M reductase (Mcr) from an unculturable organism, anaerobic methanotrophic archaeal population 1 (ANME-1) from a Black Sea mat, into M. acetivorans to effectively run methanogenesis in reverse. Starting with low-density inocula, M. acetivorans cells producing ANME-1 Mcr consumed up to 9Â Â±Â 1Â % of methane (corresponding to 109Â Â±Â 12Â Âµmol of methane) after 6Â weeks of anaerobic growth on methane and utilized 10Â mM FeCl3 as an electron acceptor. Accordingly, increases in cell density and total protein were observed as cells grew on methane in a biofilm on solid FeCl3. When incubated on methane for 5Â days, high-densities of ANME-1 Mcr-producing M. acetivorans cells consumed 15Â Â±Â 2Â % methane (corresponding to 143Â Â±Â 16Â Âµmol of methane), and produced 10.3Â Â±Â 0.8Â mM acetate (corresponding to 52Â Â±Â 4Â Âµmol of acetate). We further confirmed the growth on methane and acetate production using (13)C isotopic labeling of methane and bicarbonate coupled with nuclear magnetic resonance and gas chromatography/mass spectroscopy, as well as RNA sequencing.We anticipate that our metabolically-engineered strain will provide insights into how methane is cycled in the environment by Archaea as well as will possibly be utilized to convert remote sources of methane into more easily transported biofuels via acetate.
Eccrine Angiomatous Hamartoma: A Clinicopathologic Review of 18 Cases. - The American Journal of dermatopathology
Eccrine angiomatous hamartoma (EAH) is a benign cutaneous lesion defined by the proliferation of hamartomatous eccrine and capillary-like vascular elements in the dermis. However, the epidemiologic, morphologic, and histopathologic aspects of this uncommon disorder have yet to be fully delineated.The authors retrospectively reviewed 18 EAH cases (including 14 accompanying skin biopsy specimens) diagnosed at 4 American university hospitals from 1996 to 2014.Patients ranged from 3 days to 84 years at time of diagnosis with a median age of 15 years. A male:female ratio of 11:7 was observed. Sixty-seven percent of cases presented in the extremities, but lesions in the trunk and head/neck regions also occurred. Four patients had multiple lesions, and 2 displayed a segmental pattern. Histologically, dermal vascular dilatation and acanthosis often accompanied EAH's typical eccrine and vascular comingling. One individual developed EAH at the site of a recurrent squamous cell carcinoma after previous excision.Although previously thought to occur primarily as a solitary angiomatous-appearing malformation on the extremities of children, EAH may develop with some frequency in adults and may manifest in a multifocal linear distribution. The authors also raise additional histopathologic consideration in support of the vascular theory of histogenesis for this condition.
Antioxidant Drug Tempol Promotes Functional Metabolic Changes in the Gut Microbiota. - Journal of proteome research
Recent studies have identified the important role of the gut microbiota in the pathogenesis and progression of obesity and related metabolic disorders. The antioxidant tempol was shown to prevent or reduce weight gain and modulate the gut microbiota community in mice; however, the mechanism by which tempol modulates weight gain/loss with respect to the host and gut microbiota has not been clearly established. Here we show that tempol (0, 1, 10, and 50 mg/kg p.o. for 5 days) decreased cecal bacterial fermentation and increased fecal energy excretion in a dose-dependent manner. Liver (1)H NMR-based metabolomics identified a dose-dependent decrease in glycogen and glucose, enhanced glucogenic and ketogenic activity (tyrosine and phenylalanine), and increased activation of the glycolysis pathway. Serum (1)H NMR-based metabolomics indicated that tempol promotes enhanced glucose catabolism. Hepatic gene expression was significantly altered as demonstrated by an increase in Pepck and G6pase and a decrease in Hnf4a, ChREBP, Fabp1, and Cd36 mRNAs. No significant change in the liver and serum metabolomic profiles was observed in germ-free mice, thus establishing a significant role for the gut microbiota in mediating the beneficial metabolic effects of tempol. These results demonstrate that tempol modulates the gut microbial community and its function, resulting in reduced host energy availability and a significant shift in liver metabolism toward a more catabolic state.
Intestine-selective farnesoid X receptor inhibition improves obesity-related metabolic dysfunction. - Nature communications
The farnesoid X receptor (FXR) regulates bile acid, lipid and glucose metabolism. Here we show that treatment of mice with glycine-Î²-muricholic acid (Gly-MCA) inhibits FXR signalling exclusively in intestine, and improves metabolic parameters in mouse models of obesity. Gly-MCA is a selective high-affinity FXR inhibitor that can be administered orally and prevents, or reverses, high-fat diet-induced and genetic obesity, insulin resistance and hepatic steatosis in mice. The high-affinity FXR agonist GW4064 blocks Gly-MCA action in the gut, and intestine-specific Fxr-null mice are unresponsive to the beneficial effects of Gly-MCA. Mechanistically, the metabolic improvements with Gly-MCA depend on reduced biosynthesis of intestinal-derived ceramides, which directly compromise beige fat thermogenic function. Consequently, ceramide treatment reverses the action of Gly-MCA in high-fat diet-induced obese mice. We further show that FXR signalling in ileum biopsies of humans positively correlates with body mass index. These data suggest that Gly-MCA may be a candidate for the treatment of metabolic disorders.
Impaired recovery from peritoneal inflammation in a mouse model of mild dietary zinc restriction. - Molecular nutrition & food research
Mild dietary zinc (Zn) deficiency is wide-spread in human populations, but the effect on Zn-dependent processes of immune function and healing are not well understood. The consequences of mild dietary Zn restriction were examined in two mouse models of inflammation and recovery.Male C57BL/6 mice were fed a Zn adequate diet (ZA, 30 mg Zn/kg diet), or diets containing sub-optimal Zn levels (ZM, 15 mg Zn/kg diet; ZD, 10 mg Zn/kg diet) for 30 days before a thioglycollate peritonitis challenge. Plasma lipid profiles were distinct, with greater Zn restriction resulting in a greater impact on metabolites. The milder ZM diet was selected for immune studies. Peritoneal macrophages from ZM mice displayed increased phagocytosis and amplified pro-inflammatory cytokine (IL-1Î², IL-6, and TNFÎ±) release compared to ZA, at baseline and after a secondary LPS challenge. Splenocytes isolated from ZM mice displayed an increase in IL-6 and a reduction in anti-inflammatory IL-4 compared to ZA. Cytokine levels in plasma were unaltered. Following mechanical manipulation of the intestines to induce ileus, ZM mice had delayed intestinal transit compared to ZA.Mild Zn deficiency enhances local inflammatory responses, amplifying macrophage functions and delaying recovery from acute insults within the peritoneum. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.
Effect of Radiofrequency Transmit Field Correction on Quantitative Dynamic Contrast-enhanced MR Imaging of the Breast at 3.0 T. - Radiology
Purpose To investigate the effects of radiofrequency transmit field (B1(+)) correction on (a) the measured T1 relaxation times of normal breast tissue and malignant lesions and (b) the pharmacokinetically derived parameters of malignant breast lesions at 3 T. Materials and Methods Ethics approval and informed consent were obtained. Between May 2013 and January 2014, 30 women (median age, 58 years; range, 32-83 years) with invasive ductal carcinoma of at least 10 mm were recruited to undergo dynamic contrast material-enhanced magnetic resonance (MR) imaging before surgery. B1(+) and T1 mapping sequences were performed to determine the effect of B1(+) correction on the native tissue relaxation time (T10) of fat, parenchyma, and malignant lesions in both breasts. Pharmacokinetic parameters were calculated before and after correction for B1(+) variations. Results were correlated with histologic grade by using the Kruskal-Wallis test. Results Measurements showed a mean 37% flip angle difference between the right and left breast, which resulted in a 61% T10 difference in fat and a 41.5% difference in parenchyma between the two breasts. The T1 of lesions in the right breast increased by 58%, whereas that of lesions in the left breast decreased by 30% after B1(+) correction. The whole-tumor transendothelial permeability across the vascular compartment(K(trans)) of lesions in the right breast decreased by 41%, and that of lesions in the left breast increased by 46% after correction. A systematic increase in K(trans) was observed, with significant differences found across the histologic grades (P < .001). The effect size of B1(+) correction on K(trans) calculation was large for lesions in the right breast and moderate for lesions in the left breast (Cohen effect size, d = 0.86 and d = 0.59, respectively). Conclusion B1(+) correction demonstrates a substantial effect on the results of quantitative dynamic contrast-enhanced analysis of breast tissue at 3 T, which propagates into the pharmacokinetic analysis of tumors that is dependent on whether the tumor is located in the right or left breast. (Â©) RSNA, 2015.
Comparison of Gated and Ungated Black-Blood Fast Spin-echo MRI of Carotid Vessel Wall at 3T. - Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine
Multi-slice ungated double inversion recovery has been proposed as an alternative time-efficient and effective sequence for black-blood carotid imaging. The purpose of this study is to evaluate the comparative repeatability of this multi-contrast sequence with respect to a single slice double inversion recovery prepared gated sequence.Ten healthy volunteers and three patients with Doppler ultrasound defined carotid artery stenosis >30% were recruited. T1-weighted (T1W) and T2W fast spin-echo (FSE) images were acquired centered at the carotid bifurcation with and without cardiac gating. Repeat imaging was performed without patient repositioning to determine the variations in vessel wall measurement and signal intensity due to gating, while negating variations as a result of slice misalignment and anatomical displacement relative to the receiver coil. The distributions and the repeatability of lumen area, vessel wall area, signal and contrast-to-noise ratio (SNR/CNR) of the vessel wall and adjacent muscle were reported.The T1W ungated sequence generally had comparable wall SNR/CNR with respect to the gated sequence, however the muscle SNR was lower (P = 0.013). The T2W ungated multi-slice sequence had lower SNR/CNR than the gated single slice sequence (P < 0.001), but with equivalent effective wall CNR (P = 0.735). Vessel area measurements using the gated/ungated sequences were equivalent. Ungated sequences had better repeatability in SNR/CNR than the gated sequences with borderline and statistically significant differences. The repeatability of T2W wall area measurement was better using the ungated sequences (P = 0.02), and the repeatability of the remaining vessel area measurements were equivalent.Ungated sequences can achieve comparable SNR/CNR and equivalent carotid vessel area measurements than gated sequences with improved repeatability of SNR/CNR. Ungated sequences are good alternatives of gated sequences for vessel area measurement and plaque composition quantification.
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2815 Edgewood Rd Sw Cedar Rapids, IA 52404
3200 16Th Ave Sw Suite I
2600 Edgewood Rd Sw Suite 376