Low-intensity pulsed ultrasound induced enhanced adipogenesis of adipose-derived stem cells

OBJECTIVE

The aim of this study was to investigate effects of low-intensity pulsed ultrasound (LIPUS) on differentiation of adipose-derived stem cells (ASCs), in vitro.

MATERIALS AND METHODS

Murine ASCs were treated with LIPUS for either three or five days, immediately after adipogenic induction, or delayed for 2 days. Expression of adipogenic genes PPAR-γ1, and APN, was examined by real-time PCR. Immunofluorescence (IF) staining was performed to test for PPAR-γ at the protein level.

RESULTS

Our data revealed that specific patterns of LIPUS up-regulated levels of both PPAR-γ1 and APN mRNA, and PPAR-γ protein.

CONCLUSIONS

In culture medium containing adipogenic reagents, LIPUS enhanced ASC adipogenesis.

Functional homotopic changes in multiple sclerosis with resting-state functional MR imaging

BACKGROUND AND PURPOSE

CC is extensively involved in MS with interhemispheric dysfunction. The purpose of this study was to determine whether interhemispheric correlation is altered in MS by use of a recently developed RS-fMRI homotopy technique and whether these homotopic changes correlate with CC pathology.

MATERIALS AND METHODS

Twenty-four patients with relapsing-remitting MS and 24 age-matched healthy volunteers were studied with RS-fMRI and DTI acquired at 3T. The Pearson correlation of each pair of symmetric interhemispheric voxels of RS-fMRI time-series data was performed to compute VMHC, and z-transformed for subsequent group-level analysis. In addition, 5 CC segments in the midsagittal area and DTI-derived FA were measured to quantify interhemispheric microstructural changes and correlate with global and regional VMHC in MS.

RESULTS

Relative to control participants, patients with MS exhibited an abnormal homotopic pattern with decreased VMHC in the primary visual, somatosensory, and motor cortices and increased VMHC in several regions associated with sensory processing and motor control including the insula, thalamus, pallidum, and cerebellum. The global VMHC correlates moderately with the average FA of the entire CC for all participants in both groups (r = 0.3; P = .03).

CONCLUSIONS

Our data provide preliminary evidence of the potential usefulness of VMHC analyses for the detection of abnormalities of interhemispheric coordination in MS. We demonstrated that the whole-brain homotopic RS-fMRI pattern was altered in patients with MS, which was partially associated with the underlying structural degenerative changes of CC measured with FA.

Insight into the sharing of medical images: physician, other health care providers, and staff experience in a variety of medical settings

BACKGROUND

Scant knowledge exists describing health care providers' and staffs' experiences sharing imaging studies. Additional research is needed to determine the extent to which imaging studies are shared in diverse health care settings, and the extent to which provider or practice characteristics are associated with barriers to viewing external imaging studies on portable media.

OBJECTIVE

This analysis uses qualitative data to 1) examine how providers and their staff accessed outside medical imaging studies, 2) examine whether use or the desire to use imaging studies conducted at outside facilities varied by provider specialty or location (urban, suburban, and small town) and 3) delineate difficulties experienced by providers or staff as they attempted to view and use imaging studies available on portable media.

METHODS

Semi-structured interviews were conducted with 85 health care providers and medical facility staff from urban, suburban, and small town medical practices in North Carolina and Virginia. The interviews were audio recorded, transcribed, then systematically analyzed using ATLAS.ti.

RESULTS

Physicians at family and pediatric medicine practices rely primarily on written reports for medical studies other than X-rays; and thus do not report difficulties accessing outside imaging studies. Subspecialists in urban, suburban, and small towns view imaging studies through internal communication systems, internet portals, or portable media. Many subspecialists and their staff report experiencing difficulty and time delays in accessing and using imaging studies on portable media.

CONCLUSION

Subspecialists have distinct needs for viewing imaging studies that are not shared by typical primary care providers. As development and implementation of technical strategies to share medical records continue, this variation in need and use should be noted. The sharing and viewing of medical imaging studies on portable media is often inefficient and fails to meet the needs of many subspeciality physicians, and can lead to repeated imaging studies.

Identifying novel biomarkers for cardiovascular disease risk prediction

The primary prevention of cardiovascular disease relies on the ability to identify at-risk individuals long before the development of overt events. In the past decade, research into circulating, genetic and imaging biomarkers to augment traditional methods of risk prediction has only achieved modest success. Emerging technologies in the fields of genomics, metabolomics and proteomics are providing new platforms for biomarker discovery. Here, we review current concepts in the evaluation and discovery of cardiovascular biomarkers. Further research is needed to identify new biomarkers to successfully stratify risk of cardiovascular disease in low-risk populations, as well as to test whether management strategies informed by biomarker testing are better than standard of care.

Jagged-1-mediated activation of notch signalling induces adipogenesis of adipose-derived stem cells

OBJECTIVES

Notch signalling plays an important role in many cell activities, involving proliferation, migration, differentiation and cell death. The aim of this study was to investigate effects of such signalling on adipogenesis of mouse adipose-derived stem cells (mASCs).

MATERIALS AND METHODS

Jagged1 (50 and 100 ng/ml) was added to mASCs to activate Notch signalling, 2 days before adipogenic induction. At 5 and 7 days after induction, oil red-O staining was performed to evaluate lipid accumulation. Then real-time PCR was performed to examine expression of Notch downstream genes (Notch-1, -2, Hes-1 and Hey-1) and adipogenic transcription factor (PPAR-γ). Expressions of Hes-1 and PPAR-γ at protein level were confirmed by immunofluorescence staining.

RESULTS

Our data indicated that Jagged1 promoted adipogenic differentiation of mASCs. Moreover, Jagged1 also increased expression of Notch downstream genes and PPAR-γ. Expressions of Hes-1 and PPAR-γ were found to be enhanced in Jagged1 pre-treated mASCs when compared to controls.

DISCUSSION

The results led to the conclusion that activation of Notch signalling had stimulated adipogenesis of mASCs in the presence of adipogenic medium by promoting expression of PPAR-γ.

MO-D-BRB-10: Modeling Inter-Patient Variation of Organ-At-Risk Sparing in IMRT Plans: An Evidence-Based Plan Quality Evaluation

PURPOSE

To develop a predictive model to assess the quality of critical organ dose sparing in IMRT plans by providing patient specific dose sparing references, based on an array of patient anatomical features and prior planning experience.

METHODS

Contributions of various patient anatomical features to the inter-patient OAR dose sparing variation in IMRT planning were systematically studied using machine learning method based on high quality prior plans. The dependence of anatomical factor on OAR dosimetric parameters is formulated into predictive models. The OAR dosimetric parameters generated by these predictive models represent the "best feasible" clinical outcomes based on past planning experiences. IMRT plans of 88 prostate, 106 head-and-neck (HN) and 21 spine SBRT treatments were used to train the models. The final models were tested by additional 24 prostate and 48 HN plans. The model for spine SBRT was tested by the leave-one-out method.

RESULTS

For HN and prostate planning, the significant patient anatomical features that affect OAR sparing are: the distance between OAR and PTV, the portion of OAR volume within an OAR specific distance range, the overlap volume between OAR and PTV, and the portion of OAR volume outside the primary treatment field. For spine SBRT planning, the most significant patient anatomical feature that affects cord sparing is the tightness of the geometric enclosure of PTV surrounding the cord and the homogeneity of PTV dose coverage. The dosimetric parameters predicted for the test patient cases using the models were in agreement with those from the clinical plans in more than 75% of the cases.

CONCLUSIONS

The developed predictive models indicated substantial correlation between some important patient anatomical features and OAR dose sparing based on expert experiences. These models can be used as effective tools for evaluating the quality of treatment plans customized to individual patient's anatomy. Partially supported by a master research agreement with Varian Medical System, Inc.

SU-E-T-626: Individualized Trade-Off of Dose Coverage and Sparing in IMRT Planning

PURPOSE

We present an evidence-based approach to quantifying the dose sparing trade-offs between different Organs-at-risk (OARs) and the trade-off between OAR dose sparing and target dose coverage in IMRT plans.

METHODS

The interaction between dose sparing of different OARs and between target dose coverage and OAR dose sparing are modeled using high-quality prior IMRT plans of prostate, head-and-neck (HN), and spine SBRT cases. The dose sparing for each OAR is modeled separately at first based on their own anatomical features and then the contributions from other OARs or PTV are added into the model to account for the possible trade-off effects in plans whose modeled OAR DVH deviates from that of actual plans.

RESULTS

The most significant OAR dose sparing trade-off is between bladder and rectum in prostate plans and between the left and the right parotids in HN plans. Trade-off is most apparent when the parotid on one side has very large overlap with the PTV. In most of these plans (83%), the planer chooses to loosen the dose constraint for that parotid in exchange for lower contra-lateral parotid median dose. The interaction between OAR dose sparing and PTV dose coverage is most significant in spine SBRT plans, (R2=0.37). Another important factor is the tightness of the geometric enclosure of PTV around OAR (R2=0.38).

CONCLUSIONS

The dosimetric trade-off between multiple OARs and between PTV and OAR in IMRT planning is quantified by studying prior plans. These findings will help physicians and planners obtain better OAR dose sparing by exploring different trade-off options for individual patient cases. Partially supported by a master research agreement with Varian Medical Systems, Inc.

Secreted factors from adipose tissue increase adipogenic differentiation of mesenchymal stem cells

OBJECTIVES

Adipose tissue engineering is one of the hottest topics in the field of regenerative medicine. Fat tissue has been considered as an abundant and accessible source of adult stem cells by tissue engineers, since it gives rise to adipose stem cells. However, recent reports have pointed out that adipose tissue, as a secretory and endocrine organ, might secrete cytokines that regulate body functions such as metabolism, infammation and more. In this study, we aim to investigate the adipogenic-inducing factors secreted by fat tissue.

MATERIALS AND METHODS

Conditioned medium were collected by culturing fat tissue fragments in plastic flasks. Mesenchymal stem cells (MSCs) cultured in conditioned medium (CM) to test the adipogenic-inducing factors. Oil red O staining, reverse transcription/polymerase chain reaction and immunocytofluorescent staining were performed to examine the differentiation of MSCs in CM.

RESULTS

MSCs cultured in CM of adipose tissue spontaneously differentiated into adipocytes. Furthermore, supplementation of insulin or dexamethasone to CM accelerated the process of lipid accumulation of differentiated MSCs.

DISCUSSION

Results from this study demonstrated that fat tissues secrete small molecules, which induce adipogenic differentiation of MSCs.

CONCLUSIONS

Our study provides clues for improving adipose tissue engineering by using fragmented adipose tissue as sources of fat-inducing factors.

Cellular and molecular mechanisms of silibinin induces cell-cycle arrest and apoptosis on HeLa cells

Silibinin, an effective anti-cancer and chemopreventive agent in various epithelial cancer models, has been reported to inhibit cancer cell growth through mitogenic signalling pathways including cervical cancer. However, the underlying mechanisms are still not well elucidated. Here, we assessed the effect of silibinin on human cervical carcinoma cell cycle modulation, apoptosis induction and associated molecular alterations by employing HeLa cell line. Silibinin treatment of HeLa cells resulted in a G2 arrest and induced a decrease in cyclin-dependent kinases involved in both G1 and G2 progression. In addition, silibinin showed a dose-dependent and a time-dependent apoptotic death in HeLa cells in both the mitochondrial pathway and the death receptor-mediated pathway, providing a strong rationale for future studies evaluating preventive and/or intervention strategies for silibinin in cervical cancer pre-clinical models.

Brain iron quantification in mild traumatic brain injury: a magnetic field correlation study

BACKGROUND AND PURPOSE

Experimental studies have suggested a role for iron accumulation in the pathology of TBI. Magnetic field correlation MR imaging is sensitive to the presence of non-heme iron. The aims of this study are to 1) assess the presence, if any, and the extent of iron deposition in the deep gray matter and regional white matter of patients with mTBI by using MFC MR imaging; and 2) investigate the association of regional brain iron deposition with cognitive and behavioral performance of patients with mTBI.

MATERIALS AND METHODS

We prospectively enrolled 28 patients with mTBI. Eighteen healthy subjects served as controls. The subjects were administered the Stroop color word test, the Verbal Fluency Task, and the Post-Concussion Symptoms Scale. The MR imaging protocol (on a 3T imager) consisted of conventional brain imaging and MFC sequences. After the calculation of parametric maps, MFC was measured by using a region of interest approach. MFC values across groups were compared by using analysis of covariance, and the relationship of MFC values and neuropsychological tests were evaluated by using Spearman correlations.

RESULTS

Compared with controls, patients with mTBI demonstrated significant higher MFC values in the globus pallidus (P = .002) and in the thalamus (P = .036). In patients with mTBI, Stroop test scores were associated with the MFC value in frontal white matter (r = -0.38, P = .043).

CONCLUSIONS

MFC values were significantly elevated in the thalamus and globus pallidus of patients with mTBI, suggesting increased accumulation of iron. This supports the hypothesis that deep gray matter is a site of injury in mTBI and suggests a possible role for iron accumulation in the pathophysiological events after mTBI.