Hyperactive Ras/MAPK signaling is critical for tibial nonunion fracture in neurofibromin-deficient mice

Neurofibromatosis type 1 (NF1) is a common genetic disorder affecting 1 in 3500 individuals. Patients with NF1 are predisposed to debilitating skeletal manifestations, including osteopenia/osteoporosis and long bone pseudarthrosis (nonunion fracture). Hyperactivation of the Ras/mitogen-activated protein kinase (MAPK) pathway in NF1 is known to underlie aberrant proliferation and differentiation in cell lineages, including osteoclast progenitors and mesenchymal stem cells (MSCs) also known as osteoblast progenitors (pro-OBLs). Our current study demonstrates the hyper Ras/MAPK as a critical pathway underlying the pathogenesis of NF1-associated fracture repair deficits. Nf1-deficient pro-OBLs exhibit Ras/MAPK hyperactivation. Introduction of the NF1 GTPase activating-related domain (NF1 GAP-related domain) in vitro is sufficient to rescue hyper Ras activity and enhance osteoblast (OBL) differentiation in Nf1(-/-) pro-OBLs and NF1 human (h) MSCs cultured from NF1 patients with skeletal abnormalities, including pseudarthrosis or scoliosis. Pharmacologic inhibition of mitogen-activated protein kinase kinase (MEK) signaling with PD98059 partially rescues aberrant Erk activation while enhancing OBL differentiation and expression of OBL markers, osterix and osteocalcin, in Nf1-deficient murine pro-OBLs. Similarly, MEK inhibition enhances OBL differentiation of hMSCs. In addition, PD98059 rescues aberrant osteoclast maturation in Nf1 haploinsufficient bone marrow mononuclear cells (BMMNCs). Importantly, MEK inhibitor significantly improves fracture healing in an NF1 murine model, Col2.3Cre;Nf1(flox/-). Collectively, these data indicate the Ras/MAPK cascade as a critical pathway in the pathogenesis of bone loss and pseudarthrosis related to NF1 mutations. These studies provide evidence for targeting the MAPK pathway to improve bone mass and treat pseudarthrosis in NF1.

High prevalence of vitamin D insufficiency in pregnant women working indoors and residing in Guiyang, China

BACKGROUND/AIM

To assess the status of 25-hydroxyvitamin D [25(OH)D] in pregnant women in their second and third trimesters, who reside and work indoors in Guiyang, China.

SUBJECTS AND METHODS

A total of 311 pregnant women in their 12th to 40th gestational week were engaged in employment located indoors in the urban area of Guiyang and completed a questionnaire on living habits. Levels of serum 25(OH)D were measured from fasting venous blood by liquid chromatography-mass spectrometry (LC-MS/MS). Levels of 25(OH)D were classified as vitamin D deficient [25(OH)D<20 ng/ml], insufficient [20 ng/ml≤25(OH)D<30 ng/ml], or sufficient [25(OH)D≥30 ng/ml].

RESULTS

The mean serum level of 25(OH)D was 14.69±6.81 ng/ml. Vitamin D deficiency, insufficiency and sufficiency were found in 260 (83.6%), 39 (12.5%), and 12 (3.9%) women, respectively. The mean level of 25(OH)D in the third trimester was significantly higher than in the second trimester (p<0.001). The mean 25(OH)D level in summer (June, July, August) was significantly higher than in the other seasons (p<0.001). The 25(OH)D level in pregnant women compliant with pre-natal calcium or multivitamin supplements was higher than in those not taking supplements (p<0.001).

CONCLUSIONS

These results suggest that pregnant women residing in Guiyang urban area and working indoors are at high risk of vitamin D insufficiency, particularly during spring, winter, and autumn, regardless of use of pre-natal calcium and multivitamins. Appropriate vitamin D supplementation is necessary to improve maternal vitamin D nutrition.

[Effects of immunization with recombinant fusion protein of extracellular near-transmembrane domain of Tibet minipig leptin receptor on fat deposition in SD rats]

OBJECTIVE

To investigate the effect of immunization with prokaryotically expressed recombinant fusion protein of extracellular near-transmembrane domain of Tibet minipig leptin receptor (OBR) on fat deposition in SD rats.

METHODS

A pair of specific primers containing BamHI and HindIII restriction enzyme sites was designed to amplify the extracellular near-transmembrane domain (1705-2364 bp) of Tibet minipig OBR gene. After digestion, the amplified fragment was inserted into the plasmid pRSETA between BamHI and HindIII sites. The recombinant plasmid was transformed and expressed in E.coli BL21(DE3) and the product was analyzed by SDS-PAGE and Western blotting. SD rats were immunized with the fusion protein, and the changes in body weight, feed intake, body length, Lee's index, percentage of abdominal fat, liver fat deposition and subcutaneous fat deposition were assessed.

RESULTS

The recombinant fusion protein obtained (about 27.6 kD) was expressed in E.coli induced by IPTG and identified by SDS-PAGE and Western blotting. The rats immunized with the fusion protein showed no significant changes in body weight, body length, Lee's index, percentage of abdominal fat or liver fat deposition as compared with the control rats. Nevertheless, the immunization caused significantly increased feed intake and significantly decreased volume of subcutaneous fat cells.

CONCLUSION

Immunization with the fusion protein of extracellular near-transmembrane domain of Tibet minipig OBR can promote feed intake and suppress subcutaneous fat deposition in SD rats.

BaP-induced DNA damage initiated p53-independent necroptosis via the mitochondrial pathway involving Bax and Bcl-2

Benzo(a)pyrene (BaP), a typical environmental carcinogen, can induce cell death both by protein 53 or tumor protein 53 (p53)-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BaP-induced cell death. In this study, cells with different genetic background (including p53-proficient human fetal lung fibroblast cell lines (MRC-5), p53-deficient human non-small-cell lung carcinoma cell lines (H1299), and p53-knockdown cell lines (MRC-5 p53−/−)) were used to establish models of BaP-induced cell death. The results showed that BaP (8, 16, 32, and 64 μM) induced necroptotic cell death in the cell lines. The necroptotic cell death and DNA damage were concurrently observed. In the three cell lines, at 24 h after treatment, BaP (8–64 μM) upregulated expressions of BAX, BCL-2, and cleaved caspase-3 proteins, but not their messenger RNA levels. The findings suggested that BaP-induced necroptosis was modulated by the p53-independent pathway, which was related to the induction of BAX, decreased expression of BCL-2, and activation of caspase-3.

Comparisons of egg quality traits, egg weight loss and hatchability between striped and normal duck eggs

1. The egg quality of striped and normal duck eggs was compared to determine why striped eggs show decreased hatchability. A total of 430 eggs, obtained from a Pekin duck breeder flock aged 50-65 wks, were used in three experiments. The eggs were weighed and assigned randomly to measure egg quality traits, egg weight (EW) loss and hatchability during incubation. 2. There were no significant differences between egg types in terms of egg shape index, eggshell strength and thickness, albumen height, Haugh unit, yolk colour, weight of the eggshell with or without membranes, calcium, phosphorus, copper and manganese contents in the eggshell (with the inner and outer membranes or without the inner membrane), albumen weight, dry matter of albumen, crude protein (CP) of thick albumen and pH of the thick albumen. 3. The weight of eggshells with membranes, weight of thick albumen and CP of thin albumen in striped eggs were lower than those in normal eggs. 4. The thin albumen in striped eggs was heavier than that in normal eggs. The pH of the thin albumin in striped egg was significantly higher than that in normal eggs. 5. There were no significant differences in EW loss during incubation or duckling weight between striped and normal eggs. However, the hatchability of striped eggs was lower. 6. The lower weight of the eggshell inner membrane and thick albumen, lower CP content and higher pH in the thin albumen of striped eggs might contribute to lower hatchability.

The enforced expression of c-Myc in pig fibroblasts triggers mesenchymal-epithelial transition (MET) via F-actin reorganization and RhoA/Rock pathway inactivation

In previous studies from other labs it has been well demonstrated that the ectopic expression of c-Myc in mammary epithelial cells can induce epithelial-mesenchymal transition (EMT), whereas in our pilot experiment, epithelial-like morphological changes were unexpectedly observed in c-Myc-expressing pig fibroblasts [i.e., porcine embryonic fibroblasts (PEFs) and porcine dermal fibroblasts (PDFs)] and pig mesenchymal stem cells, suggesting that the same c-Myc gene is entitled to trigger EMT in epithelial cells and mesenchymal-epithelial transition (MET) in fibroblasts. This prompted us to characterize the existence of a MET in c-Myc-expressing PEFs and PDFs at the molecular level. qRT-PCR, immunofluorescence and western blot analysis illustrated that epithelial-like morphological changes were accompanied by the increased expression of epithelial markers [such as cell adhesion proteins (E-cadherin, α-catenin and Bves), tight junction protein occludin and cytokeratins (Krt8 and Krt18)], the reduced expression of mesenchymal markers [vimentin, fibronectin 1 (FN1), snail1, collagen family of proteins (COL1A1, COL5A2) and matrix metalloproteinase (MMP) family (MMP12 and MMP14)] and the decreased cell motility and increased cell adhesion in c-Myc-expressing PEFs and PDFs. Furthermore, the ectopic expression of c-Myc in pig fibroblasts disrupted the stress fiber network, suppressed the formation of filopodia and lamellipodia, and resulted in RhoA/Rock pathway inactivation, which finally participates in epithelial-like morphological conversion. Taken together, these findings demonstrate, for the first time, that the enforced expression of c-Myc in fibroblasts can trigger MET, to which cytoskeleton depolymerization and RhoA/Rock pathway inactivation contribute.

MRP8/14 enhances corneal susceptibility to Pseudomonas aeruginosa Infection by amplifying inflammatory responses

PURPOSE

We explored the role of myeloid-related protein 8 and 14 (MRP8/14) in Pseudomonas aeruginosa (PA) keratitis.

METHODS

MRP8/14 mRNA levels in human corneal scrapes and mouse corneas infected by PA were tested using real-time PCR. MRP8/14 protein expression in C57BL/6 (B6) corneas was confirmed using Western blot assay and immunohistochemistry. B6 mice were injected subconjunctivally with siRNA for MRP8/14, and then infected with PA. Bacterial plate counts and myeloperoxidase assays were used to determine the bacterial load and polymorphonuclear neutrophil (PMN) infiltration in infected B6 corneas. Pro-inflammatory cytokine levels in vivo and in vitro were examined with PCR and ELISA. In murine macrophage-like RAW264.7 cells, phagocytosis and bacterial killing were assessed using plate count assays, and reactive oxygen species (ROS) and nitric oxide (NO) levels were tested with flow cytometry and Griess assay, respectively.

RESULTS

MRP8/14 expression levels were increased significantly in human corneal scrapes and B6 corneas after PA infection. Silencing of MRP8/14 in B6 corneas significantly reduced the severity of corneal disease, bacterial clearance, PMN infiltration, and pro-inflammatory cytokine expression after PA infection. In vitro studies demonstrated further that silencing of MRP8/14 suppressed pro-inflammatory cytokine production, bacterial killing, and ROS production, but not phagocytosis or NO production.

CONCLUSIONS

Our study demonstrated a dual role for MRP8/14 in bacterial keratitis. Although MRP8/14 promotes bacterial clearance by enhancing ROS production, it functions more importantly as an inflammatory amplifier at the ocular surface by enhancing pro-inflammatory cytokine expression, thus contributing to the corneal susceptibility.

Relationship between angiogenesis and lymphangiogenesis in recurrent pterygium

AIM

To examine the relationship between angiogenesis and lymphangigenesis in recurrent pterygia.

METHODS

Tissues from 34 excised recurrent pterygia (including 12 Grade 1, 10 Grade 2, and 12 Grade 3) were involved in the study and tissues from 7 nasal epibulbar conjunctivae segments were used as controls. Sections from each pterygium were immunostained with CD(31) and LYVE-1 monoclonal antibodies to evaluate lymphatic microvessel density (LMVD) and blood microvessel density (BMVD), and the relationship between LMVD and BMVD in the pterygium was examined.

RESULTS

There was a large number of CD(31) ((+))LYVE-1((-)) blood vessels but only a few CD(31) ((+))LYVE-1((+)) lymphatic vessels in grades 1 and 2 pterygium. However, lymphatic vessels were dramatically increased in grade 3 pterygium. LMVD correlated closely with BMVD in all pterygia, including grades 1, 2 and 3 peterygium patients (all P values <0.01). Although both the density of blood and lymphatic vessels increased in recurrent pterygia, lymphatic vessels developed much faster than blood vessels, especially in grade 3 pterygia.

CONCLUSION

There is a significant but not parallel relationship between angiogenesis and lymphangiogenesis in recurrent pterygium. The outgrowth of blood and lymphatic vessels provide evidence that immunological mechanism may play a role in the development and recurrence of pterygium.

Outcome in single and twin pregnancies at 20 to 24 weeks gestation: ten years experience in one perinatal center

OBJECTIVE

The aim of this investigation was to evaluate the outcome at 20 to 24 weeks gestation of twin and singleton extremely low birth weight infants.

STUDY DESIGN

The authors conducted a retrospective cohort study of live newborns at 20 to 24 weeks gestation admitted to one neonatal intensive care unit (NICU) from 2000 to 2009. Outcome mortality and predictors of outcome were evaluated. Results were compared for twin and singleton infants.

RESULTS

The cohort of infants consisted of 60 singleton infants and 17 twins. The results suggest an increased risk of death for twins when compared with singletons. A correlation between neonatal C-reactive protein (CRP) and bacterial culture positive results on admission to NICU might be a predictor of neonatal outcome.

CONCLUSION

In extremely low birth weight infants, twin delivery is associated with an independent increased risk of death. Both first- and second-born twins are at increased risk.

Prevalence, Spectrum and Antibiotic Susceptibility of Bacterial and Candida Colonization between the 21st and 33rd Week of Gestation in Women with PPROM - 5 Years' Experience in 1 Perinatal Center

Objective: The aim of this study was to evaluate the prevalence, spectrum and antibiotic susceptibility of bacterial and Candida colonization of the vagina between the 21st and the 33rd week of gestation in women who had preterm premature rupture of membranes (PPROM). Study design: High vaginal swabs from 245 subjects with PPROM were analyzed in a retrospective cohort study using cultivation-dependent methods. Patients were additionally divided into two groups: women with PPROM between the 21st and 27th week of gestation (group A) and women with PPROM between the 28th and 33rd week of gestation (group B). A subgroup analysis comparing the two groups was done. Results: The prevalence of pathological bacterial colonization was similar in both study groups (40.8 vs. 41.4 %; p > 0.05), however, a difference in antibiotic susceptibility was noted, which did not reach statistical significance (resistance to ampicillin 71.4 vs. 52.5 %; cefuroxime 9.5 vs. 11.7 %; gentamicin 28.6 vs. 16.4 %; ciprofloxacin 5.0 vs. 5.4 %). In group A there was a statistically significant lower rate of Candida colonization (11.1 vs. 24.3 %; p = 0.04). Conclusion: In patients with early PPROM, the rate of Candida colonization (group A) is lower and there are indications of a difference in antibiotic susceptibility of the colonizing bacteria depending on gestational age. Larger study groups are required to confirm these preliminary results.

Electromagnetic vortex fields, spin, and spin-orbit interactions in electron vortices

Electron vortices are shown to possess electric and magnetic fields by virtue of their quantized orbital angular momentum and their charge and current density sources. The spatial distributions of these fields are determined for a Bessel electron vortex. It is shown how these fields lead naturally to interactions involving coupling to the spin magnetic moment and spin-orbit interactions which are absent for ordinary electron beams. The orders of magnitude of the effects are estimated here for ȧngström scale electron vortices generated within a typical electron microscope.

Normal hematopoiesis and neurofibromin-deficient myeloproliferative disease require Erk

Neurofibromatosis type 1 (NF1) predisposes individuals to the development of juvenile myelomonocytic leukemia (JMML), a fatal myeloproliferative disease (MPD). In genetically engineered murine models, nullizygosity of Nf1, a tumor suppressor gene that encodes a Ras-GTPase-activating protein, results in hyperactivity of Raf/Mek/Erk in hematopoietic stem and progenitor cells (HSPCs). Activated Erk1/2 phosphorylate kinases and transcription factors with myriad mitogenic roles in diverse cell types. However, genetic studies examining Erk1/2's differential and/or combined control of normal and Nf1-deficient myelopoiesis are lacking. Moreover, prior studies relying on chemical Mek/Erk inhibitors have reached conflicting conclusions in normal and Nf1-deficient mice. Here, we show that while single Erk1 or Erk2 disruption did not grossly compromise myelopoiesis, dual Erk1/2 disruption rapidly ablated granulocyte and monocyte production in vivo, diminished progenitor cell number, and prevented HSPC proliferation in vitro. Genetic disruption of Erk1/2 in the context of Nf1 nullizygosity (Mx1Cre(+)Nf1(flox/flox)Erk1(-/-)Erk2(flox/flox)) fully protects against the development of MPD. Collectively, we identified a fundamental requirement for Erk1/2 signaling in normal and Nf1-deficient hematopoiesis, elucidating a critical hematopoietic function for Erk1/2 while genetically validating highly selective Mek/Erk inhibitors in a leukemia that is otherwise resistant to traditional therapy.

Identification of Serum MicroRNA-21 as a Biomarker for Chemosensitivity and Prognosis in Human Osteosarcoma

Objective:

The aim of this study was to investigate the serum level of microRNA (miR)-21 in patients with osteosarcoma and its correlation with chemosensitivity and prognosis.

Methods:

miR-21 levels in sera from 65 patients with osteosarcoma and 30 healthy controls were measured by real-time reverse transcription-polymerase chain reaction. Correlations between serum miR-21 and clinicopathological features in patients with osteosarcoma were determined. The prognostic significance of serum miR-21 was assessed using a Cox proportional hazards model.

Results:

The serum level of miR-21 was significantly higher in patients with osteosarcoma than in control subjects. High serum miR-21 was significantly correlated with advanced Enneking stage and chemotherapeutic resistance. Univariate and multivariate analyses for overall survival showed that upregulation of serum miR-21 was an independent, unfavourable prognostic factor for patients with osteosarcoma (hazard ratio, 2.325).

Conclusions:

miR-21 might be a good candidate for a therapeutic target, and a potential biomarker for the prediction of chemotherapeutic sensitivity and prognosis in patients with osteosarcoma.

c-Fms signaling mediates neurofibromatosis Type-1 osteoclast gain-in-functions

Skeletal abnormalities including osteoporosis and osteopenia occur frequently in both pediatric and adult neurofibromatosis type 1 (NF1) patients. NF1 (Nf1) haploinsufficient osteoclasts and osteoclast progenitors derived from both NF1 patients and Nf1(+/-) mice exhibit increased differentiation, migration, and bone resorptive capacity in vitro, mediated by hyperactivation of p21(Ras) in response to limiting concentrations of macrophage-colony stimulating factor (M-CSF). Here, we show that M-CSF binding to its receptor, c-Fms, results in increased c-Fms activation in Nf1(+/) (-) osteoclast progenitors, mediating multiple gain-in-functions through the downstream effectors Erk1/2 and p90RSK. PLX3397, a potent and selective c-Fms inhibitor, attenuated M-CSF mediated Nf1(+/-) osteoclast migration by 50%, adhesion by 70%, and pit formation by 60%. In vivo, we administered PLX3397 to Nf1(+/-) osteoporotic mice induced by ovariectomy (OVX) and evaluated changes in bone mass and skeletal architecture. We found that PLX3397 prevented bone loss in Nf1(+/-)-OVX mice by reducing osteoclast differentiation and bone resorptive activity in vivo. Collectively, these results implicate the M-CSF/c-Fms signaling axis as a critical pathway underlying the aberrant functioning of Nf1 haploinsufficient osteoclasts and may provide a potential therapeutic target for treating NF1 associated osteoporosis and osteopenia.

Prevalence of buried Barrett's metaplasia in patients before and after radiofrequency ablation

BACKGROUND AND STUDY AIM

Radiofrequency ablation (RFA) to treat Barrett's esophagus is increasingly accepted. Description of the etiology, natural history, and prevalence of buried Barrett's metaplasia (BBM) following RFA is limited, although BBM continues to pose a clinical dilemma. We aimed to assess the prevalence, characteristics, and eradication rate of BBM in patients with both dysplastic and nondysplastic Barrett's esophagus, treated with RFA and followed over time.

PATIENTS AND METHODS

The presence of Barrett's esophagus, dysplasia, and BBM, before and after RFA, was assessed by two gastrointestinal pathologists in a retrospective chart review of patients who had undergone RFA at our center and had completed appropriate follow-up.

RESULTS

We identified 112 patients with completed treatment and no further planned RFA. In 108, no residual Barrett's esophagus was seen after RFA; 4 patients with persistent Barrett's tissue underwent surgery. Regarding BBM, 17/112 patients (15.2%) had evidence of BBM during evaluation. In 12/17 (70.5%) BBM was found during the RFA treatment, with 8 having previously undergone non-RFA therapy and RFA for Barrett's esophagus and 4 having no previous intervention. In 5/17 (29.4%), BBM was seen only after RFA monotherapy. All 17 showed no evidence of BBM at final evaluation and were classified in the complete remission group (108/112).

CONCLUSION

Both Barrett's esophagus and BBM were completely eradicated in all patients with long-term follow-up after RFA. Almost half of the patients with BBM had a prior history of non-RFA therapy for Barrett's esophagus compared with 26% the non-BBM cohort. All patients with previously identified Barrett's esophagus and BBM were completely cleared of disease at final follow-up.

Mechanism of TNF-α autocrine effects in hypoxic cardiomyocytes: initiated by hypoxia inducible factor 1α, presented by exosomes

Excessive tumor necrosis factor-α (TNF-α) expression is increasingly thought to be detrimental to cardiomyocytes in acute myocardial infarction. During myocardial ischemia, TNF-α is mainly released from macrophages, but with persistent ischemia, it can originate from cardiomyocytes and contribute to cardiac remodeling. The initiating factor and exact molecular mechanism of TNF-α release from cardiomyocytes is presently unclear. In this study, we investigated direct effects of hypoxia on TNF-α expression of cardiomyocytes, the role of hypoxia inducible factor-1α (HIF-1α) in TNF-α regulation and potential secretory pathway of TNF-α. Elevated TNF-α expression and HIF-1α activation in primary cultured cardiomyocytes under hypoxia were detected by real-time PCR, Western blotting and immunofluorescence. TNF-α mRNA elevation and protein secretion were obviously inhibited by nucleofection of HIF-1α small interfering RNA (siRNA) and treatment with 2-methoxyestradiol (inhibitor of HIF-1α protein). Similar results were observed in HEK293 and HepG2 cells. Putative hypoxia response elements were identified in the human TNF-α gene promoter. Deletion analysis and site-directed mutagenesis demonstrated that HIF consensus binding sites spanning bp-1295 to bp-1292 relative to the transcription start site were functional for activation of the TNF-α promoter which was confirmed by electrophoretic mobility-shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analysis. Exosomes (vesicles mediating a non-classical route of protein secretion) in supernatants from hypoxic cardiomyocytes were identified by an anti-CD63 antibody in Western blot and observed by electron microscopy. The presence of TNF-α within exosomes precipitated from supernatants of hypoxic cardiomyocytes was verified by immunoelectron microscopy and immunoblotting. Results of this study indicate that under hypoxia, HIF-1α initiates expression of TNF-α, mediated by exosomes in cardiomyocytes.

Liver T1ρ MRI measurement in healthy human subjects at 3 T: a preliminary study with a two-dimensional fast-field echo sequence

OBJECTIVES

The aim of this study was to explore the technical feasibility of T(1)ρ MRI for the liver, and to determine the normal range of liver T(1)ρ in healthy subjects at clinical 3 T.

METHODS

There were 15 healthy volunteers. Three representative axial slices were selected to cut through the upper, middle and lower liver. A rotary echo spin-lock pulse was implemented in a two-dimensional fast-field echo sequence. Spin-lock frequency was 500 Hz, and the spin-lock times of 1, 10, 20, 30, 40 and 50 ms were used for T(1)ρ mapping. The images were acquired slice by slice during breath-holding. Regions of interest (ROIs; n=5) were manually placed on each slice of the liver parenchyma region, excluding artefacts and vessels. The mean value of these ROIs (n=15) was regarded as the liver T(1)ρ value for the subject. Six subjects were scanned once at fasting status; six subjects were scanned once 2 h post meal; three subjects were scanned twice at fasting status; and seven subjects were scanned twice 2 h post meal.

RESULTS

When two readers measured the same 10 data sets, the interreader reproducibility (ICC: intraclass correlation coefficient) was 0.955. With the 10 subjects scanned twice, the ICC for scan-rescan reproducibility was 0.764. There was no significant difference for the liver T(1)ρ value at the fasting status (43.08±1.41 ms) and post-meal status (42.97±2.38 ms, p=0.867). Pooling together all the 32 scans in this study, the normal liver T(1)ρ value ranged from 38.6 to 48.3 ms (mean 43.0 ms, median 42.6 ms).

CONCLUSION

It is feasible to obtain consistent liver T(1)ρ measurement for human subjects at 3 T.