Effects of amniotic epithelial cell transplantation in endothelial injury

Purpose

Human amniotic epithelial cells (hAECs) are promising tools for endothelial repair in vascular regenerative medicine. We hypothesized that these epithelial cells are capable of repairing the damaged endothelial layer following balloon injury of the carotid artery in adult male rats.

Results

Two days after injury, the transplanted hAECs were observed at the luminal side of the arterial wall. Then, 4 weeks after the injury, significant intimal thickening was observed in both untreated and cell implanted vessels. Constriction was decreased in both implanted and control animals. Immunohistochemical analysis showed a few surviving cells in the intact arterial wall, but no cells were observed at the site of injury. Interestingly, acetylcholine-induced dilation was preserved in the intact side and the sham-transplanted injured arteries, but it was a trend toward decreased vasodilation in the hAECs’ transplanted vessels.

Conclusion

We conclude that hAECs were able to incorporate into the arterial wall without immunosuppression, but failed to improve vascular function, highlighting that morphological implantation does not necessarily result in functional benefits and underscoring the need to understand other mechanisms of endothelial regeneration.

Systolic Compression of a Myocardial Bridged Coronary Artery and its Morphologic Characteristics: A Combination Study of Computed Tomography Angiography and Invasive Angiography

Background

Myocardial bridging (MB) is a congenital anomaly in which a segment of a major epicardial coronary artery courses through the myocardium. This anomaly can lead to myocardial ischemia, arrhythmia, and even death. The effectiveness of coronary computed tomographic angiography (CCTA) in the detection of MB and its morphological features, and the accuracy of invasive coronary angiography (ICA) in the evaluation of systolic compression have been shown in some prior studies.

Objectives

The present study aimed to evaluate the correlation between the depth and the length of MB as determined using CCTA, and the degree of luminal narrowing of the involved tunneled segment as calculated using the ICA.

Patients and Methods

For this study, 109 consecutive patients diagnosed with myocardial bridging using CCTA, and who had already undergone ICA, were studied. The depth and length of the MB was determined in the CCTA, while the degree of systolic compression was calculated in the ICA. The correlation between the depth and length of the MB and the systolic compression were then evaluated.

Results

The degree of systolic compression was found to be correlated with the depth of the MB. However, there was no correlation between the length of the MB and the degree of systolic compression.

Conclusion

The systolic compression of the MB was influenced by the depth of the tunneled segment, not by its length.

Vascular Disease in Young Indians (20-40 years): Role of Ischemic Heart Disease

Coronary Artery Disease (CAD) occurs at a younger age in Indians with over 50% of Cardiovascular Disease (CVD) mortality occurring in individuals aged less than 50 years. Although several risk factors have been suggested; smoking, dyslipidemia and hypertension are major risk factors in the young. In this review, we have pooled the current evidence on Ischemic Heart Disease (IHD) in young (20-40 years) and provided an opinion for the effective management of IHD in young Indians.

Antiangiogenic Therapy Induces Hepatic Tumor Vascular Network Rearrangement to Receive Perfusion via the Portal Vein and Hepatic Artery

PURPOSE

Hepatic malignancies can easily develop resistance to antiangiogenic therapy, but the underlying mechanism remains poorly understood. This study explores whether antiangiogenic therapy influences the tumor vascular network and/or the vessels feeding the hepatic tumor.

METHODS

Mice implanted with Lewis lung carcinoma (LLC) cells were subcutaneously injected 3 times (once every other day starting 1 week after LLC implantation) with either an antiangiogenic agent [vascular endothelial growth factor (VEGF)-Trap] or control agent (bovine serum albumin) at a dose of 25 mg/kg before performing angiography. Hepatic arteriography and portography were performed using a vascular cast method with vascular latex.

RESULTS

Arteriography of the control-treated LLC-implanted mice showed marked staining of the mass with a prominent feeding artery, suggesting that the tumor is supplied by arterial perfusion. No significant staining was observed on portography. By contrast, 33% (n = 3/9) of the LLC-implanted mice treated with the antiangiogenic agent VEGF-Trap showed intratumoral staining during portography, indicating that these tumors received perfusion via the portal vein.

CONCLUSION

Antiangiogenic treatment can induce rearrangement of the hepatic tumor vascular network to establish communication with the portal vein. This implies that hepatic tumors can develop resistance to antiangiogenic therapy by maintaining perfusion through portal venous perfusion.

The value of 64-slice spiral CT perfusion imaging in the treatment of liver cancer with argon-helium cryoablation

We analyzed the effectiveness of using 64-slice spiral computed tomography (CT) and perfusion imaging to guide argon-helium cryoablation treatment of liver cancer. In total, 60 cases of advanced hepatocellular carcinoma before surgery treated with argon-helium cryoablation were inlcuded in the present study. Retrospective summary of the 60 cases of metaphase and advanced liver cancer were used as the control group. The control group were treated using cryoablation with argon-helium knife. We used enhanced scanning with 64-slice spiral CT to define the extent of their lesions and prepared a plan of percutaneous cryoablation for the treatment. Intraoperatively, we used the dynamics of CT perfusion imaging to observe the frozen ablation range and decreased the rate of complications. After surgery, the patients were followed-up regularly by 64-slice CT. We used conventional X-ray, CT and magnetic resonance imaging (MRI) for pre-operative lateralization. Intraoperative X-ray or ultrasound guidance and follow-up with CT or MTI were added to determine the clinical effectiveness and prognosis. The results showed that the total effective rate was improved significantly and incidence rate of overall complications decreased markedly in the observation group. Following treatment, AFP decreased significantly while the total freezing area and time were reduced significantly. The median survival time was increased significantly in the observation group. The numeric values of hepatic arterial perfusion, portal vein perfusion and hepatic arterial perfusion index were all markedly lowered after treatment. Differences were statistically significant (P<0.05). In conclusion, the use of 64-slice spiral CT perfusion imaging may considerably improve the effects of liver cancer treatment using the argon-helium cryoablation. It extended the survival time and reduced complications.

K-space trajectory mapping and its application for ultrashort Echo time imaging

MR images are affected by system delays and gradient field imperfections which induce discrepancies between prescribed and actual k-space trajectories. This could be even more critical for non-Cartesian data acquisitions where even a small deviation from the assumed k-space trajectory results in severe image degradation and artifacts. Knowledge of the actual k-space trajectories is therefore crucial and can be incorporated in the reconstruction of high quality non-Cartesian images. A novel MR method for the calibration of actual gradient waveforms was developed using a combination of phase encoding increments and subsequent detection of the exact time point at which the corresponding trajectory is crossing the k-space origin. The measured sets of points were fitted to a parametrical model to calculate the complete actual acquisition trajectory. Measurements performed on phantoms and volunteers, positioned both in- and off-isocenter of the magnet, clearly demonstrate the improvement in reconstructed ultrashort echo time (UTE) images, when information from calibration of k-space sampling trajectories is employed in the MR image reconstruction procedure. The unique feature of the proposed method is its robustness and simple experimental setup, making it suitable for quick acquisition trajectory calibration procedures e.g. for non-Cartesian radial fast imaging.

The role of quantitation of real-time 3-dimensional contrast-enhanced ultrasound in detecting microvascular invasion: an in vivo study

PURPOSE

This study was to evaluate the role of quantitative perfusion analysis of 3-dimensional (3D) contrast-enhanced ultrasound (CEUS) in detecting microvascular invasion (MVI) of liver tumor in vivo.

METHODS

VX2 tumors were implanted in the livers of sixteen New Zealand rabbits. On day 10, real-time 3D CEUS was performed, and the real-time dynamic images were analyzed using online quantification software. The animals were sacrificed and sent for pathology examinations. According to the gold standard of pathology, the animals were divided into an MVI group and a group without MVI (non-MVI group). Time-intensity curves (TICs) were obtained for the VX2 tumors and the surrounding liver parenchyma, and the parameters peak intensity (PI), mean transit time (MTT), and time to peak (TTP) were compared within and between the MVI and non-MVI groups.

RESULTS

The TTP and MTT of the VX2 tumors were significantly faster than those of the surrounding liver parenchyma in both MVI and non-MVI groups. The PI of the VX2 tumors was significantly lower than that of the surrounding liver parenchyma in the non-MVI group but not the MVI group. The TTP and MTT of the VX2 tumors and surrounding liver parenchyma were not significantly different in the MVI group compared with the non-MVI group, whereas the ΔPI (the PI ratio between the VX2 liver tumors and the reference liver parenchyma) of the VX2 tumors in the MVI group was larger than that in the non-MVI group. VX2 tumors with MVI present different hemodynamic parameters, with a larger ΔPI than tumors without MVI.

CONCLUSIONS

Our data suggest that quantitative perfusion analysis of 3D CEUS might be a promising method for predicting MVI in liver tumors.

Glycosaminoglycan chemical exchange saturation transfer in human lumbar intervertebral discs: Effect of saturation pulse and relationship with low back pain

PURPOSE

To evaluate the dependence of saturation pulse power and duration on glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging and assess the degeneration of human lumbar intervertebral discs (IVDs) using this method.

MATERIALS AND METHODS

All images were acquired on a 3T magnetic resonance imaging (MRI) scanner. The CEST effects were measured in the glycosaminoglycan (GAG) phantoms with different concentrations. In the human study, CEST effects were measured in the nucleus pulposus of IVD. We compared the CEST effects among the different saturation pulse powers (0.4, 0.8, and 1.6 μT) or durations (0.5, 1.0, and 2.0 sec) at each Pfirrmann grade (I-V). The relationship between the CEST effects and low back pain was also evaluated.

RESULTS

The phantom study showed high correlations between the CEST effects and GAG concentration (R²  = 0.863, P < 0.0001, linear regression). In the human study, the CEST effect obtained with the 0.8 μT power was significantly greater than those obtained with 0.4 (P < 0.01) and 1.6 μT power (P < 0.05) at Pfirrmann grade I. The CEST effect obtained with a 1.0-sec duration was significantly greater than those derived with 0.5 and 2.0 sec (P < 0.01) durations at Pfirrmann grades I and II. The CEST effects in the group with moderate low back pain were significantly lower than those in the groups without pain (P < 0.001) and with mild pain (P = 0.0216).

CONCLUSION

The contrast of gagCEST imaging in the lumbar IVDs varied with saturation pulse power and duration. GagCEST imaging may serve as a tool for evaluating IVD degeneration in the lumbar spine.

LEVEL OF EVIDENCE

2 J. Magn. Reson. Imaging 2017;45:863-871.

Assessment of the myelin water fraction in rodent spinal cord using T2-prepared ultrashort echo time MRI

OBJECTIVE

Multi-component T2 relaxation allows for assessing the myelin water fraction in nervous tissue, providing a surrogate marker for demyelination. The assessment of the number and distribution of different T2 components for devising exact models of tissue relaxation has been limited by T2 sampling with conventional MR methods.

MATERIALS AND METHODS

A T2-prepared UTE sequence was used to assess multicomponent T2 relaxation at 9.4 T of fixed mouse and rat spinal cord samples and of mouse spinal cord in vivo. For in vivo scans, a cryogenically cooled probe allowed for 78-µm resolution in 1-mm slices. Voxel-wise non-negative least square analysis was used to assess the number of myelin water-associated T2 components.

RESULTS

More than one myelin water-associated T2 component was detected in only 12 % of analyzed voxels in rat spinal cords and 6 % in mouse spinal cords, both in vivo and in vitro. However, myelin water-associated T2 values of individual voxels varied between 0.1 and 20 ms. While in fixed samples almost no components below 1 ms were identified, in vivo, these contributed 14 % of the T2 spectrum. No significant differences in MWF were observed in mouse spinal cord in vivo versus ex vivo measurements.

CONCLUSION

Voxel-wise analysis methods using relaxation models with one myelin water-associated T2 component are appropriate for assessing myelin content of nervous tissue.

Can ultrashort-TE (UTE) MRI sequences on a 3-T clinical scanner detect signal directly from collagen protons: freeze-dry and D2 O exchange studies of cortical bone and Achilles tendon specimens

Ultrashort-TE (UTE) sequences can obtain signal directly from short-T2 , collagen-rich tissues. It is generally accepted that bound and free water can be detected with UTE techniques, but the ability to detect protons directly on the collagen molecule remains controversial. In this study, we investigated the potential of UTE sequences on a 3-T clinical scanner to detect collagen protons via freeze-drying and D2 O-H2 O exchange studies. Experiments were performed on bovine cortical bone and human Achilles tendon specimens, which were either subject to freeze-drying for over 66 h or D2 O-H2 O exchange for 6 days. Specimens were imaged using two- and three-dimensional UTE with Cones trajectory techniques with a minimum TE of 8 μs at 3 T. UTE images before treatment showed high signal from all specimens with bi-component T2 * behavior. Bovine cortical bone showed a shorter T2 * component of 0.36 ms and a longer T2 * component of 2.30 ms with fractions of 78.2% and 21.8% by volume, respectively. Achilles tendon showed a shorter T2 * component of 1.22 ms and a longer T2 * component of 15.1 ms with fractions of 81.1% and 18.9% by volume, respectively. Imaging after freeze-drying or D2 O-H2 O exchange resulted in either the absence or near-absence of signal. These results indicate that bound and free water are the sole sources of UTE signal in bovine cortical bone and human Achilles tendon samples on a clinical 3-T scanner. Protons on the native collagen molecule are not directly visible when imaged using UTE sequences. Copyright © 2016 John Wiley & Sons, Ltd.

Rapid measurement of brain macromolecular proton fraction with transient saturation transfer MRI

PURPOSE

To develop an efficient MRI approach to estimate the nonwater proton fraction (f) in human brain.

METHODS

We implement a brief, efficient magnetization transfer (MT) pulse that selectively saturates the magnetization of the (semi-) solid protons, and monitor the transfer of this saturation to the water protons as a function of delay after saturation.

RESULTS

Analysis of the transient MT effect with two-pool model allowed robust extraction of f at both 3 and 7 T. This required estimating the longitudinal relaxation rate constant (R_1,MP and R_1,WP ) for both proton pools, which was achieved with the assumption of uniform R_1,MP and R_1,WP across brain tissues. Resulting values of f were approximately 50% higher than reported previously, which is partly attributed to MT-pulse efficiency and R_1,MP being higher than assumed previously.

CONCLUSION

Experiments performed on human brain in vivo at 3 and 7 T demonstrate the ability of the method to robustly determine f in a scan time of approximately 5 min. Magn Reson Med 77:2174-2185, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Magnetic resonance imaging of myelin using ultrashort Echo time (UTE) pulse sequences: Phantom, specimen, volunteer and multiple sclerosis patient studies

Clinical magnetic resonance imaging of multiple sclerosis (MS) has focused on indirect imaging of myelin in white matter by detecting signal from protons in the water associated with myelin. Here we show that protons in myelin can be directly imaged using ultrashort echo time (UTE) free induction decay (FID) and imaging sequences on a clinical 3T MR scanner. An adiabatic inversion recovery UTE (IR-UTE) sequence was used to detect signal from myelin and simultaneously suppress signal from water protons. Validation studies were performed on myelin lipid and myelin basic protein (MBP) phantoms in the forms of lyophilized powders as well as suspensions in D2O and H2O. IR-UTE sequences were then used to image MS brain specimens, healthy volunteers, and patients. The T2* of myelin was measured using a UTE FID sequence, as well as UTE and IR-UTE sequences at different TEs. T2* values of ~110-330μs were measured with UTE FID, as well as with UTE and IR-UTE sequences for myelin powders, myelin-D2O and myelin-H2O phantoms, consistent with selective imaging of myelin protons with IR-UTE sequences. Our studies showed myelin selective imaging of white matter in the brains in vitro and in vivo. Complete or partial signal loss was observed in specimens in areas of the brain with histopathologic evidence of myelin loss, and in the brain of patients with MS.

Diffusion Weighted Imaging, Diffusion Tensor Imaging, and T2* Mapping of Lumbar Intervertebral Disc in Young Healthy Adults

Background:

Although conventional magnetic resonance imaging (MRI) could provide excellent detection of morphological changes in the diagnosis of lumbar disc degeneration (LDD), it has some difficulties in discriminating minimal changes associated with early LDD before morphological or clinical alterations. Therefore, newer MRI techniques have emerged for investigation of early LDD.

Objectives:

The aim of this study was to use diffusion weighted imaging (DWI), diffusion Tensor Imaging (DTI) and T2* mapping to detect lumbar discs in healthy young adults, to evaluate if they could depict the microstructural changes of early LDD.

Patients and Methods:

Apparent diffusion coefficient (ADC), fractional anisotropy (FA), and T2* images of the lumbar discs were obtained for 40 asymptomatic young subjects (19 males and 21 females; mean age of 24.3 years), using DWI, DTI and T2* mapping with a 1.5-T MRI scanner. ADC, FA, and T2* values were measured to compare five regions of interest (ROI) selected in each nucleus pulposus (NP) of the images.

Results:

The ADC, FA, and T2* values were different (P < 0.05) among different ROIs within the same disc or among corresponding ROIs in different level discs. While the average values of ADC increased regularly with the lowering of the anatomical location (P < 0.05), the average FA and T2* values also associated with the anatomic locations, showed an increase in L4-L5 and L5-S1 discs (P < 0.05).

Conclusion:

ADC, FA, and T2* values may quantitatively reflect the microstructural characteristics of NP, therefore they could be used to detect the minimal changes of early LDD.

Comparison of mono-exponential and bi-exponential models of diffusion-weighted MRI in diagnosis of small VX2 hepatic tumors in rabbits

AIM: To investigate the value of mono-exponential model with single b-factor and bi-exponential model with extended b-factor range of diffusion-weighted imaging (DWI) in diagnosis of small VX2 hepatic tumors ( ≤ 3 cm) in rabbits.

METHODS: On the 7^th day and 14^th day after tumor implantation, 50 New Zealand white rabbits with VX2 hepatic tumors underwent DWI based on single b-factor (b values of 0 and 800 s/mm²) and multi-b-factor (b values of 0, 20, 50, 100, 200, 400, 600, 800 and 1200 s/mm²). Apparent diffusion coefficient (ADC), slow ADC, fast ADC and fraction fast ADC (f_fast) were measured in the rim of tumor (TR) and the normal region (NR) and compared between the two groups. The best thresholds of ADC, slow ADC, fast ADC and f_fast were calculated by the receiver operating characteristic curve (ROC).

RESULTS: There were significant differences between TR and NR in ADC values on days 7 and 14 (P < 0.05). The values of slow ADC of TR were superior than those of NR on both days 7 and 14. Fast ADC and f_fast of NR were higher than those of TR on the 14^th day (P < 0.05). Expect for slow ADC, no statistical difference was observed in ADC, Fast-ADC or f_fast of TR between the 7^th day and 14^th day. Slow ADC offered the highest sensitivity and specificity compared to ADC, slow-ADC, fast-ADC and f_fast for differentiating between TR and NR on both days 7 and 14.

CONCLUSION: The parameter values of mono-exponential model and bi-exponential model, especially slow-ADC, reflect perfusion of microcirculation and diffusion of water molecules, thus having value for the diagnosis of small hepatic tumors.

Blueberry treatment attenuated cirrhotic and preneoplastic lesions and oxidative stress in the liver of diethylnitrosamine-treated rats

Diethylnitrosamine (DEN)-induced liver cancer normally develops in stages that progress from cirrhosis and carcinoma. Increased oxidative stress is suggested to play a role in DEN-induced carcinogenicity. Blueberries (BB) contain high antioxidant capacity. We investigated the effect of BB supplementation on development of DEN-induced cirrhosis and neoplastic lesions in the liver. Rats were injected with DEN (200 mg/kg; i.p.) three times with an interval of 15 days at 4, 6, and 8 weeks and sacrificed 8 weeks after the last DEN injection. They were also fed on 8% BB (w/w) containing chow for 16 weeks. Hepatic damage markers in serum were determined together with hepatic histopathological examinations. Hydroxyproline (HYP), malondialdehyde (MDA), diene conjugate (DC), protein carbonyl (PC), and glutathione (GSH) levels, and CuZn-superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities, and their mRNA expressions were measured. Protein and mRNA expressions of glutathione transferase-pi (GST-pi) were evaluated as a marker of preneoplastic lesions. BB supplementation decreased hepatic damage markers in serum and hepatic MDA, DC, and PC levels, but SOD, CAT, and GSH-Px activities and their mRNA expressions remained unchanged in DEN-treated rats. BB attenuated cirrhotic changes and decreased hepatic HYP levels and GST-pi expressions. Our results indicate that BB is effective in decreasing development of DEN-induced hepatic cirrhosis and preneoplastic lesions by acting as an antioxidant (radical scavenger) itself without affecting activities and mRNA expressions of antioxidant enzymes.

Decoding Advances in Psychiatric Genetics: A Focus on Neural Circuits in Rodent Models

Appropriately powered genome-wide association studies combined with deep-sequencing technologies offer the prospect of real progress in revealing the complex biological underpinnings of schizophrenia and other psychiatric disorders. Meanwhile, recent developments in genome engineering, including CRISPR, constitute better tools to move forward with investigating these genetic leads. This review aims to assess how these advances can inform the development of animal models for psychiatric disease, with a focus on schizophrenia and in vivo electrophysiological circuit-level measures with high potential as disease biomarkers.

The power of using functional fMRI on small rodents to study brain pharmacology and disease

Functional magnetic resonance imaging (fMRI) is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD) fMRI techniques, including resting state (rsfMRI), stimulus-evoked (st-fMRI), and pharmacological MRI (phMRI). Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sensory stimulation and/or a pharmacological challenge. The first part of this review describes the physiological basis of BOLD fMRI and the hemodynamic response on which the MRI contrast is based. Specific emphasis goes to possible effects of anesthesia and the animal’s physiological conditions on neural activity and the hemodynamic response. The second part of this review describes applications of the aforementioned techniques in pharmacologically induced, as well as in traumatic and transgenic disease models and illustrates how multiple fMRI methods can be applied successfully to evaluate different aspects of a specific disorder. For example, fMRI techniques can be used to pinpoint the neural substrate of a disease beyond previously defined hypothesis-driven regions-of-interest. In addition, fMRI techniques allow one to dissect how specific modifications (e.g., treatment, lesion etc.) modulate the functioning of specific brain areas (st-fMRI, phMRI) and how functional connectivity (rsfMRI) between several brain regions is affected, both in acute and extended time frames. Furthermore, fMRI techniques can be used to assess/explore the efficacy of novel treatments in depth, both in fundamental research as well as in preclinical settings. In conclusion, by describing several exemplary studies, we aim to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with several methodological considerations.

Perfusion CT imaging of the liver: review of clinical applications

Perfusion computed tomography (CT) has a great potential for determining hepatic and portal blood flow; it offers the advantages of quantitative determination of lesion hemodynamics, distinguishing malignant and benign processes, as well as providing morphological data. Many studies have reported the use of this method in the assessment of hepatic tumors, hepatic fibrosis associated with chronic liver disease, treatment response following radiotherapy and chemotherapy, and hepatic perfusion changes after radiological or surgical interventions. The main goal of liver perfusion imaging is to improve the accuracy in the characterization of liver disorders. In this study, we reviewed the clinical application of perfusion CT in various hepatic diseases.

In vitro Study of a Novel Stent Coating Using Modified CD39 Messenger RNA to Potentially Reduce Stent Angioplasty-Associated Complications

Background

Stent angioplasty provides a minimally invasive treatment for atherosclerotic vessels. However, no treatment option for atherosclerosis-associated endothelial dysfunction, which is accompanied by a loss of CD39, is available, and hence, adverse effects like thromboembolism and restenosis may occur. Messenger RNA (mRNA)-based therapy represents a novel strategy, whereby de novo synthesis of a desired protein is achieved after delivery of a modified mRNA to the target cells.

Methods and Findings

Our study aimed to develop an innovative bioactive stent coating that induces overexpression of CD39 in the atherosclerotic vessel. Therefore, a modified CD39-encoding mRNA was produced by in vitro transcription. Different endothelial cells (ECs) were transfected with the mRNA, and CD39 expression and functionality were analyzed using various assays. Furthermore, CD39 mRNA was immobilized using poly(lactic-co-glycolic-acid) (PLGA), and the transfection efficiency in ECs was analyzed. Our data show that ECs successfully translate in vitro-generated CD39 mRNA after transfection. The overexpressed CD39 protein is highly functional in hydrolyzing ADP and in preventing platelet activation. Furthermore, PLGA-immobilized CD39 mRNA can be delivered to ECs without losing its functionality.

Summary

In summary, we present a novel and promising concept for a stent coating for the treatment of atherosclerotic blood vessels, whereby patients could be protected against angioplasty-associated complications.

Ramped hybrid encoding for improved ultrashort echo time imaging

PURPOSE

We propose a new acquisition to minimize the per-excitation encoding duration and improve the imaging capability for short T2 * species.

METHODS

In the proposed ramped hybrid encoding (RHE) technique, gradients are applied before the radiofrequency (RF) pulse as in pointwise encoding time reduction with radial acquisition (PETRA) and zero echo time (ZTE) imaging. However, in RHE, gradients are rapidly ramped after RF excitation to the maximum amplitude to minimize encoding duration. To acquire central k-space data not measured during RF deadtime, RHE uses a hybrid encoding scheme similar to PETRA. A new gradient calibration method based on single-point imaging was developed to estimate the k-space trajectory and enable robust and high quality reconstruction.

RESULTS

RHE enables a shorter per-excitation encoding time and provides the highest spatial resolution among ultrashort T2 * imaging methods. In phantom and in vivo experiments, RHE exhibited robust imaging with negligible chemical shift or blurriness caused by T2 * decay and unwanted slice selection.

CONCLUSION

RHE allows the shortest per-excitation encoding time for ultrashort T2 * imaging, which alleviates the impact of fast T2 * decay occurring during encoding, and enables improved spatial resolution. Magn Reson Med 76:814-825, 2016. © 2015 Wiley Periodicals, Inc.

A peripheral primitive neuroectodermal tumor originating from the pancreas: a case report and review of the literature

A peripheral primitive neuroectodermal tumor (pPNET) is a small round cell tumor occurring mostly in children or young adults and categorized into the Ewing sarcoma family of tumors. pPNETs originating from the pancreas are especially rare, and only 25 cases have been reported in the literature. We report a case of a 22-year-old man who had a giant expansive tumor located in the uncinate process of the pancreas, 80 mm in diameter resulting in obstruction in the duodenum. The patient underwent a pancreaticoduodenectomy. The histological examination showed that the pancreatic tumor was composed of atypical small round cells. Immunohistochemical findings were positive for CD99. An Ewing sarcoma breakpoint region 1 gene 22q12 rearrangement was proven by a two-color fluorescence in situ hybridization assay. We diagnosed the tumor as a pPNET of the pancreas, which, according to the literature, is highly aggressive with poor prognosis. A multidisciplinary approach to treat these neoplasms should improve the prognoses.

Loss and re-adaptation of lumbar intervertebral disc water signal intensity after prolonged bedrest

The adaptation and re-adaptation process of the intervertebral disc (IVD) to prolonged bedrest is important for understanding IVD physiology and IVD herniations in astronauts. Little information is available on changes in IVD composition. In this study, 24 male subjects underwent 60-day bedrest and In/Out Phase magnetic resonance imaging sequences were performed to evaluate IVD shape and water signal intensity. Scanning was performed before bedrest (baseline), twice during bedrest, and three, six and twenty-four months after bedrest. Area, signal intensity, average height, and anteroposterior diameter of the lumbar L3/4 and L4/5 IVDs were measured. At the end of bedrest, disc height and area were significantly increased with no change in water signal intensity. After bedrest, we observed reduced IVD signal intensity three months (p=0.004 versus baseline), six months (p=0.003 versus baseline), but not twenty-four months (p=0.25 versus baseline) post-bedrest. At these same time points post-bedrest, IVD height and area remained increased. The reduced lumbar IVD water signal intensity in the first months after bedrest implies a reduction of glycosaminoglycans and/or free water in the IVD. Subsequently, at two years after bedrest, IVD hydration status returned towards pre-bedrest levels, suggesting a gradual, but slow, re-adaptation process of the IVD after prolonged bedrest.

Multiple sclerosis lesion geometry in quantitative susceptibility mapping (QSM) and phase imaging

PURPOSE

To demonstrate the phase and quantitative susceptibility mapping (QSM) patterns created by solid and shell spatial distributions of magnetic susceptibility in multiple sclerosis (MS) lesions.

MATERIALS AND METHODS

Numerical simulations and experimental phantoms of solid- and shell-shaped magnetic susceptibility sources were used to generate magnitude, phase, and QSM images. Imaging of 20 consecutive MS patients was also reviewed for this Institutional Review Board (IRB)-approved MRI study to identify the appearance of solid and shell lesions on phase and QSM images.

RESULTS

Solid and shell susceptibility sources were correctly reconstructed in QSM images, while the corresponding phase images depicted both geometries with shell-like patterns, making the underlying susceptibility distribution difficult to determine using phase alone. In MS patients, of the 60 largest lesions identified on T2 , 30 lesions were detected on both QSM and phase, of which 83% were solid and 17% were shells on QSM, and of which 30% were solid and 70% were shell on phase. Of the 21 shell-like lesions on phase, 76% appeared solid on QSM, 24% appeared shell on QSM. Of the five shell-like lesions on QSM, all were shell-like on phase.

CONCLUSION

QSM accurately depicts both solid and shell patterns of magnetic susceptibility, while phase imaging fails to distinguish them.

Comparison of reendothelialization and neointimal formation with stents coated with antibodies against endoglin and CD34 in a porcine model

Anti-CD34 coated stents are the only commercialized antibody-coated stents currently used for coronary artery diseases with various limitations. Endoglin plays important roles in the proliferation of endothelial cells and vascular remodeling and could be an ideal target surface molecule. The objective of this study was to investigate the efficacy of stents coated with anti-endoglin antibodies (ENDs) in terms of endothelial recovery and the reduction of neointimal formation. The performance of ENDs was evaluated by comparing with stents coated with anti-CD34 antibodies (CD34s), sirolimus-eluting stents (SESs), and bare metal stents (BMSs). Stents were randomly assigned and placed in the coronary arteries of juvenile pigs. Histomorphometric analysis and scanning electron microscopy were performed after stent implantation. Our results showed at 14 days after stent implantation, the neointima area and percent area stenosis in ENDs and CD34s were remarkably decreased compared with those in BMSs and SESs (P<0.05). Moreover, the percentage of reendothelialization was significantly higher in ENDs and CD34s than that in SESs or BMSs at both 7 and 14 days (P<0.05). There was no difference in the neointima area, percent area stenosis, and percentage of reendothelialization in ENDs compared with CD34s. The artery injury and the inflammation scores were similar in all groups at both 7 and 14 days. Our results demonstrate that the performance of ENDs is similar to the commercial CD34s, without the disadvantages of CD34s, and both are better than SESs and BMSs. ENDs potentially offer an alternative approach to reduce restenotic process and enhance reendothelialization after stent implantation.

ZTE imaging with long-T2 suppression

Three-dimensional radial zero echo time (ZTE) imaging enables efficient direct MRI of tissues with rapid transverse relaxation. Yet, the feature of capturing signals with a wide range of T2 and T2 * values is accompanied by a lack of contrast between the corresponding tissues. In particular, the targeted short-T2 tissues may not be easily identified, and various approaches have been proposed to generate T2 contrast by reducing the long-T2 signal of water and/or fat. The aim of this work was to provide efficient long-T2 suppression for selective direct MRI of short-T2 tissues using the ZTE technique. For magnetization preparation, suppression pulses for water and fat were designed to provide both good T2 selectivity and off-resonance performance. To obtain high efficiency at short TRs, the pulses were applied in a segmented sequence scheme with minimized timing overhead, thus leading to a quasi-steady state of magnetization. The sequence timing was adjusted for optimal tissue contrast in musculoskeletal applications by means of simulations and experiments, incorporating both T2 and T1 of the involved tissues. The developed technique was employed for imaging of a lamb joint sample at 4.7 T. ZTE images were obtained with effective suppression of signals from tissues with long-T2 water, such as muscle or articular spaces, and fat. Hence, primarily short-T2 tissues were visible, such as bone and tendon. The MR image intensity of bone showed strong similarity with bone density imaged with micro-computed tomography.

Effect of hypothermia in patients undergoing simultaneous carotid endarterectomy and coronary artery bypass graft surgery

Purpose

We sought to determine whether hypothermia provided any benefit in patients undergoing simultaneous coronary artery bypass graft surgery (CABG) and carotid endarterectomy (CEA) using one of two different surgical strategies.

Methods

Group 1 patients (n = 34, 88.2% male, mean age 65.94 ± 6.67 years) underwent CEA under moderate hypothermia before cross clamping the aorta, whereas group 2 patients (n = 23, 69.6% male, mean age 65.78 ± 9.29 years) underwent CEA under normothermic conditions before initiating cardiopulmonary bypass (CPB). Primary outcome of interest was the occurrence of any new neurological event.

Results

The two groups were similar in terms of baseline characteristics. Permanent impairment occurred in one patient (2.9%) in group 1. One patient from each group (2.9 and 4.3%) had transient neurological events and they recovered completely on the sixth and 11th postoperative days, respectively. Overall, there was no statistically significant difference between the two groups with regard to occurrence of early neurological outcomes (n = 2, 5.8% vs n = 1, 4.3%, p = 0.12).

Conclusions

This study could not provide evidence regarding benefit of hypothermia in simultaneous operations for carotid and coronary artery disease because of the low occurrence rate of adverse outcomes. The single-stage operation is safe and completion of the CEA before CPB may be considered when short duration of CPB is required.

Effects of Electroacupuncture Stimulation at "Zusanli" Acupoint on Hepatic NO Release and Blood Perfusion in Mice

The study is to observe the influence of electroacupuncture (EA) stimulation at "Zusanli" (ST36) on the release of nitric oxide (NO) and blood perfusion (BP) in the liver and further explore whether the hepatic blood perfusion (HBP) changes were regulated by EA ST36 induced NO in nitric oxide synthase inhibited mice. The HBP change of the mice was detected by laser speckle perfusion imaging (LSPI) before and after being given interventions, and the NO in liver tissue was detected by nitric acid reductase in each group. The NO levels and HBP in the L-NAME group were significantly lower than those in the control group (P < 0.01). The NO level and HBP increase in EA group were significantly higher than those in control group (P < 0.05). The NO level in the L-NAME EA group was slightly higher than that in the L-NAME group. The HBP increase in the L-NAME EA group was not statistically significant. These results showed that EA could accelerate the synthesis of NO and thereby increase HBP via vasodilation in liver tissue.

The reduction of volume and fiber bundle connections in the hippocampus of EGR3 transgenic schizophrenia rats

BACKGROUND AND OBJECTIVE

There is a growing consensus that schizophrenia is ultimately caused by abnormal communication between spatially disparate brain structures. White matter fasciculi represent the primary infrastructure for long distance communication in the brain. In this study, we aimed to investigate the white matter connection in schizophrenia susceptible brain regions of early growth response factor 3 (EGR3) expressing rats.

METHODS

A rat model of schizophrenia was created by the transfection of the EGR3 gene into rat hippocampus. All animals were placed in a fixation system using a commercial rat-dedicated coil. Schizophrenia susceptible brain regions were scanned using in vivo diffusion tensor magnetic resonance imaging. The volume, quantity, average length of fiber bundles, fractional anisotropy, apparent diffusion coefficient, the relative heterosexual fraction, and volume ratio were collected in the whole brain and schizophrenia related brain areas (the hippocampus, thalamus, and prefrontal lobe). MedINRIA software was used for data processing of diffusion tensor and fiber bundles tracking. The fibronectin in relevant brain regions was also analyzed.

RESULTS

There was a significant decrease in the volume of the fiber beam through the left hippocampus dentate in the schizophrenia model group in comparison to the control group and the risperidone treatment group (P<0.05). A significant reduction in the volume and number of the fiber bundles was also observed in left prefrontal-left hippocampus, left hippocampus-left thalamus, left prefrontal-left hippocampus-left thalamus areas in the model group (all P<0.05).

CONCLUSION

The volume of hippocampus and the number of fiber bundles were reduced in EGR3 transgenic schizophrenia rats, and are the most sensitive indicators in schizophrenia. The diffusion tensor imaging technique plays an important role in the evaluation of patients with schizophrenia.

Myocardial bridging: a review with emphasis on electrocardiographic findings

BACKGROUND

Myocardial bridging (MB) occurs when a segment of an epicardial coronary artery takes an intra- myocardial course, thus leading to systolic compression. Most myocardial bridges involve the left anterior descending artery and are observed in 14-35% of patients. Different pathophysiological mechanisms can induce symptoms secondary to myocardial ischemia: systolic coronary compression, diastolic dysfunction associated with aging and coronary atherosclerosis, LV hypertrophy, vasospasm, microvascular and endothelial dysfunction, plaque development proximal to the bridge.

METHODS

We performed a literature review of MB, with a particular emphasis on electrocardiographic manifestations.

RESULTS

Stable angina-like chest pain is the usual presentation and MB should be suspected in patients at low risk for coronary atherosclerosis which refer this symptom or which present myocardial ischemia at instrumental examinations. ECG changes are not specific for MB and resting ECG is often normal or presents ST segment anomalies. Exercise stress test often shows non specific signs of ischemia, conduction disturbances or arrhythmias which do not allow the distinction between myocardial bridging and other causes of myocardial ischemia; angina often appears during exercise, even in the absence of ECG changes. Myocardial perfusion deficits at scintigraphy are neither obligatory nor specific. Although the clinical significance of MB is still debated, MB has been associated with acute coronary syndrome, coronary vasospasm, and even sudden cardiac death.

CONCLUSION

Although MB may lead to myocardial ischemia during stress, its clinical presentation and electrocardiographic findings are not specific.

A correlation of computed tomography perfusion and histopathology in tumor edges of hepatocellular carcinoma

BACKGROUND

The peripheral morphologic characteristics of hepatocellular carcinoma (HCC) reflect tumor growth patterns. Computed tomography (CT) perfusion is a new method to analyze hemodynamic changes in tissues. We assessed the relationship between CT perfusion and histopathologic findings in the periphery of HCC lesions.

METHODS

Non-contrast CT, enhanced dual-phase CT, and CT perfusion were performed on 77 subjects (47 patients and 30 controls). Based on the imaging findings of enhanced dual-phase CT, the tumor edges were classified into three types: type I (sharp); type II (blurry); and type III (mixed). The CT perfusion parameters included hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion. The tissue sections from resected specimens were subjected to routine hematoxylin and eosin staining and immunohistochemical staining for CD34. The correlations between microvessel density (MVD) and the CT perfusion parameters were analyzed using Pearson's product-moment correlation coefficient. Changes in the perfusion parameters in tumor edges of different tumor types were evaluated.

RESULTS

Type I (sharp): the pathologic findings showed fibrous connective tissue capsules in the tumor edges, and an MVD ≤30/mm2. Type II (blurry): the histology showed that the edges were clear with no capsules and an MVD>30/mm2. Type III (mixed): the pathology was similar to that of types I and II, and an MVD>30/mm2. Hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion were significantly increased in the tumor edges of HCC patients compared to those of the controls (P<0.05). The correlation between CT perfusion parameters and MVD was higher in blurry tumor edges of type II than in those of types I or III.

CONCLUSION

CT perfusion imaging of tumor edges may be helpful in revealing histopathological features, and indirectly reflect angiogenic changes of HCCs.

Evaluation of efficacy of anti-angiogenesis therapy for VX2 hepatic tumors in rabbits by spectral CT and CT perfusion imaging

AIM: To explore the efficacy of anti-angiogenesis therapy for VX2 hepatic tumors in rabbits by spectral computed tomography (CT) imaging and CT perfusion imaging.

METHODS: Sixty New Zealand white rabbits with implanted VX2 hepatic tumors were randomly divided into two groups (A and B), with each group containing 30 rabbits. On day 14 after tumor implantation, group B received intravenous endostatin at a dose of 3 mg/kg for 7 d. Both groups underwent spectral CT and CT perfusion scans on day 21 after tumor implantation. The animals were then sacrificed, and the expression of VEGF mRNA and FGF2 protein in the tumor rim (TR) and the normal region (NR) was detected by RT-PCR and Western blot, respectively.

RESULTS: For CT perfusion parameters, group A showed increased blood flow (BF), blood volume (BV), permeability surface (PS) and hepatic arterial fraction (HAF) and decreased mean transit time (MTT) in the TR compared with NR (P < 0.05). From days 14 to 21, BF and PS showed an increasing trend, while MTT decreased with tumor growth (P < 0.05). The standardization of iodine (NIC) during arterial phase of the TR and NR exhibited a statistically significant difference (P < 0.05). The NIC of the TR during the arterial phase was significantly higher on day 21 than on day 14. Compared with group A on day 21, BF, BV, PS and HAF decreased, and MTT increased in group B. Pearson correlation analysis showed that these parameters were positively correlated with VEGF mRNA and FGF2 protein expression.

CONCLUSION: Spectral imaging and CT perfusion imaging can provide hemodynamic information of liver lesions and quantitatively reflect the efficacy of anti-angiogenesis therapy.

Mesenteric and splenic contributions to portal venous CT perfusion in hepatic diffuse disease

AIM

To investigate the changes and contributions of superior mesenteric venous perfusion (SMVP) and splenic venous perfusion (SpVP) to portal venous CT perfusion in canine model of hepatic diffuse disease.

MATERIALS AND METHODS

By selective catheterization in superior mesenteric and splenic arteries respectively after CT perfusion scanning, SMVP and SpVP became available. Sixteen dogs were adopted and induced by carbon tetrachloride after data under normal conditions were collected. After 3, 6, 9 and 12 months from carbon tetrachloride intervention, liver biopsies by puncture or operation were performed after CT perfusion scanning. SMVP and SpVP under different pathologic conditions were compared and analyzed.

RESULTS

Three stages of hepatic diffuse lesions were defined according to pathologic changes, namely hepatitis, hepatic fibrosis, and cirrhosis. The number of dogs which survived from each stage was: 16 from normal, 12 from hepatitis, 10 from hepatic fibrosis and 4 from cirrhosis. During this progressive period, SpVP ml/(min·100 ml) declined slightly, but there were no significant differences between different stages (P > 0.05). SMVP ml/(min·100 ml) in stage of normal (64.1 ± 8.1) and hepatic fibrosis (44.4 ± 4.5), normal and cirrhosis (42.6 ± 5.4), hepatitis (61.3 ± 6.4) and hepatic fibrosis, hepatitis and cirrhosis was significantly different, but there was no significant difference of SMVP between normal and hepatitis (P = 0.326) or hepatic fibrosis and cirrhosis (P = 0.668).

CONCLUSIONS

With our evidence of interventional CT perfusion, it is mesenteric, not splenic, perfusion that might coincide with hepatic portal venous perfusion during the progressive period of hepatic diffuse disease.

Age related reduction of T1rho and T2 magnetic resonance relaxation times of lumbar intervertebral disc

This report aims to study the age related T1rho and T2 relaxation time changes in lumbar intervertebral disc. Lumbar sagittal magnetic resonance imaging (MRI) was performed with a 3 Tesla scanner in 52 subjects. With a spin-lock frequency of 500 Hz, T1rho was measured using a rotary echo spin-lock pulse embedded in a 3D balanced fast field echo sequence. A multi-echo turbo spin echo sequence was used for T2 mapping. Regions-of-interest were drawn over the T1rho and T2 maps, including nucleus pulposus and annulus fibrosus. For L1/2-L4/5 discs, results showed the age associated reduction of T1rho of nucleus pulposus had a of slope of -1.06, the reduction of T2 of nucleus pulposus had a slope of -1.47, the reduction of T1rho of annulus fibrosus had a slope of -0.25, and the reduction of T2 of annulus fibrosus had a slope of -0.18, with all the slopes significantly non-zero. In nucleus pulposus the slope of T2 was slightly steeper than that of T1rho (P=0.085), while in annulus fibrosus the slope of T1rho was slightly steeper than that of T2 (P=0.31). We conclude that significant age related reduction of T1rho and T2 magnetic resonance relaxation times of lumbar intervertebral disc was observed, however, the relative performances of T1rho vs. T2 were broadly similar.

Measurement of T1 of the ultrashort T2* components in white matter of the brain at 3T

Recent research demonstrates that white matter of the brain contains not only long T2 components, but a minority of ultrashort T2* components. Adiabatic inversion recovery prepared dual echo ultrashort echo time (IR-dUTE) sequences can be used to selectively image the ultrashort T2* components in white matter of the brain using a clinical whole body scanner. The T2*s of the ultrashort T2* components can be quantified using mono-exponential decay fitting of the IR-dUTE signal at a series of different TEs. However, accurate T1 measurement of the ultrashort T2* components is technically challenging. Efficient suppression of the signal from the majority of long T2 components is essential for robust T1 measurement. In this paper we describe a novel approach to this problem based on the use of IR-dUTE data acquisitions with different TR and TI combinations to selectively detect the signal recovery of the ultrashort T2* components. Exponential recovery curve fitting provides efficient T1 estimation, with minimized contamination from the majority of long T2 components. A rubber phantom and a piece of bovine cortical bone were used for validation of this approach. Six healthy volunteers were studied. An averaged T2* of 0.32±0.09 ms, and a short mean T1 of 226±46 ms were demonstrated for the healthy volunteers at 3T.

Simultaneous coronary artery bypass grafting and carotid endarterectomy can be performed with low mortality rates

Introduction

There is controversy over the best approach for patients with concomitant carotid and coronary artery disease. In this study, we report on our experience with simultaneous carotid endarterectomy (CEA) and coronary artery bypass graft (CABG) surgery in our clinic in the light of data in the literature.

Methods

Between January 1996 and January 2009, a total of 110 patients (86 males, 24 females; mean age 65.11 ± 7.81 years; range 44–85 years), who were admitted to the cardiovascular surgery clinic at our hospital, were retrospectively analysed. All patients underwent simultaneous CEA and CABG. Demographic characteristics of the patients and a history of previous myocardial infarction (MI), hypertension, diabetes mellitus, hyperlipidaemia, peripheral arterial disease and smoking were recorded.

Results

One patient (0.9%) with major stroke died due to ventricular fibrillation. Peri-operative neurological complications were observed in seven patients (6%). Complications were persistent in two patients. Four patients (3%) had postoperative major stroke, whereas three patients (2%) had transient hemiparesis. No peri-operative myocardial infarction was observed.

Conclusion

Simultaneous CEA and CABG can be performed with low rates of mortality and morbidity.

A propensity score analysis on the effect of on-pump versus off-pump coronary artery bypass grafting for patients with coronary artery disease

AIM

The aim of this retrospective observational study was to investigate the effect of on-pump versus off-pump coronary artery bypass grafting (CABG) for patients with coronary artery diseases (CAD).

METHODS

A retrospective observational study was performed using a propensity score analysis in 290 consecutive patients undergoing CABG between April 2009 and March 2014, of them, 54 patients undergoing off-pump CABG (OPCABG) were matched with 54 patients undergoing on-pump CABG (ONCABG) by propensity score. The perioperative complications and hospital mortality were documented.

RESULTS

Preoperative characteristics were comparable in both groups following propensity matching. Postoperative myocardial infarction (MI) incidence was lower in OPCABG group than in ONCABG group (3.7% vs. 14.8%, P=0.046); both hospital mortality and the major complications rates were similar in the two groups after propensity adjustment for preoperative characteristics.

CONCLUSIONS

The perioperative complications are similar in both off-pump and on pump CABG groups, the short-term effect of OPCABG is similar to that of ONCABG.

A propensity score analysis on the effect of on-pump versus off-pump coronary artery bypass grafting for patients with coronary artery disease

AIM

The aim of this retrospective observational study was to investigate the effect of on-pump versus off-pump coronary artery bypass grafting (CABG) for patients with coronary artery diseases (CAD).

METHODS

A retrospective observational study was performed using a propensity score analysis in 290 consecutive patients undergoing CABG between April 2009 and March 2014, of them, 54 patients undergoing off-pump CABG (OPCABG) were matched with 54 patients undergoing on-pump CABG (ONCABG) by propensity score. The perioperative complications and hospital mortality were documented.

RESULTS

Preoperative characteristics were comparable in both groups following propensity matching. Postoperative myocardial infarction (MI) incidence was lower in OPCABG group than in ONCABG group (3.7% vs. 14.8%, P=0.046); both hospital mortality and the major complications rates were similar in the two groups after propensity adjustment for preoperative characteristics.

CONCLUSIONS

The perioperative complications are similar in both off-pump and on pump CABG groups, the short-term effect of OPCABG is similar to that of ONCABG.

Computed tomography (CT) perfusion as an early predictive marker for treatment response to neoadjuvant chemotherapy in gastroesophageal junction cancer and gastric cancer--a prospective study

Objectives

To evaluate whether early reductions in CT perfusion parameters predict response to pre-operative chemotherapy prior to surgery for gastroesophageal junction (GEJ) and gastric cancer.

Materials and Methods

Twenty-eight patients with adenocarcinoma of the gastro-esophageal junction (GEJ) and stomach were included. Patients received three series of chemotherapy before surgery, each consisting of a 3-week cycle of intravenous epirubicin, cisplatin or oxaliplatin, concomitant with capecitabine peroral. The patients were evaluated with a CT perfusion scan prior to, after the first series of, and after three series of chemotherapy. The CT perfusion scans were performed using a 320-detector row scanner. Tumour volume and perfusion parameters (arterial flow, blood volume and permeability) were computed on a dedicated workstation with a consensus between two radiologists. Response to chemotherapy was evaluated by two measures. Clinical response was defined as a tumour size reduction of more than 50%. Histological response was evaluated based on residual tumour cells in the surgical specimen using the standardized Mandard Score 1 to 5, in which values of 1 and 2 were classified as responders, and 3 to 5 were classified as nonresponders.

Results

A decrease in tumour permeability after one series of chemotherapy was positively correlated with clinical response after three series of chemotherapy. Significant changes in permeability and tumour volume were apparent after three series of chemotherapy in both clinical and histological responders. A cut-off value of more than 25% reduction in tumour permeability yielded a sensitivity of 69% and a specificity of 58% for predicting clinical response.

Conclusion

Early decrease in permeability is correlated with the likelihood of clinical response to pre-operative chemotherapy in GEJ and gastric cancer. As a single diagnostic test, CT Perfusion only has moderate sensitivity and specificity in response assessment of pre-operative chemotherapy making it insufficient for clinical decision purposes.

Pushing CT and MR imaging to the molecular level for studying the "omics": current challenges and advancements

During the past decade, medical imaging has made the transition from anatomical imaging to functional and even molecular imaging. Such transition provides a great opportunity to begin the integration of imaging data and various levels of biological data. In particular, the integration of imaging data and multiomics data such as genomics, metabolomics, proteomics, and pharmacogenomics may open new avenues for predictive, preventive, and personalized medicine. However, to promote imaging-omics integration, the practical challenge of imaging techniques should be addressed. In this paper, we describe key challenges in two imaging techniques: computed tomography (CT) and magnetic resonance imaging (MRI) and then review existing technological advancements. Despite the fact that CT and MRI have different principles of image formation, both imaging techniques can provide high-resolution anatomical images while playing a more and more important role in providing molecular information. Such imaging techniques that enable single modality to image both the detailed anatomy and function of tissues and organs of the body will be beneficial in the imaging-omics field.

Quantitative T2 magnetic resonance imaging compared to morphological grading of the early cervical intervertebral disc degeneration: an evaluation approach in asymptomatic young adults

Objective

The objective of this study was to evaluate the efficacy of quantitative T2 magnetic resonance imaging (MRI) for quantifying early cervical intervertebral disc (IVD) degeneration in asymptomatic young adults by correlating the T2 value with Pfirrmann grade, sex, and anatomic level.

Methods

Seventy asymptomatic young subjects (34 men and 36 women; mean age, 22.80±2.11 yr; range, 18–25 years) underwent 3.0-T MRI to obtain morphological data (one T1-fast spin echo (FSE) and three-plane T2-FSE, used to assign a Pfirrmann grade (I–V)) and for T2 mapping (multi-echo spin echo). T2 values in the nucleus pulposus (NP, n = 350) and anulus fibrosus (AF, n = 700) were obtained. Differences in T2 values between sexes and anatomic level were evaluated, and linear correlation analysis of T2 values versus degenerative grade was conducted.

Findings

Cervical IVDs of healthy young adults were commonly determined to be at Pfirrmann grades I and II. T2 values of NPs were significantly higher than those of AF at all anatomic levels (P<0.000). The NP, anterior AF and posterior AF values did not differ significantly between genders at the same anatomic level (P>0.05). T2 values decreased linearly with degenerative grade. Linear correlation analysis revealed a strong negative association between the Pfirrmann grade and the T2 values of the NP (P = 0.000) but not the T2 values of the AF (P = 0.854). However, non-degenerated discs (Pfirrmann grades I and II) showed a wide range of T2 relaxation time. T2 values according to disc degeneration level classification were as follows: grade I (>62.03 ms), grade II (54.60–62.03 ms), grade III (<54.60 ms).

Conclusions

T2 quantitation provides a more sensitive and robust approach for detecting and characterizing the early stage of cervical IVD degeneration and to create a reliable quantitative in healthy young adults.

Expression of NF-κB, CD68 and CD105 in carotid atherosclerotic plaque

Atherosclerotic plaque vulnerability is associated with cerebrovascular events in patients with carotid atherosclerosis. The aim of this study was to investigate the expression of inflammatory factors in carotid artherosclerotic plaques in order to explore its clinical significance in patients with carotid stenosis. Forty three patients with carotid stenosis were divided into symptomatic group (n=24) and asymptomatic group (n=19) based on clinical manifestation. All patients were treated with selective standard carotid endarterectomy (CEA); the carotid atherosclerotic plaques were removed surgically and studied pathologically to investigate the expression of nuclear factor-kappa κ (NF-κB), CD68 and CD105. The plaques were grouped into stable and unstable plaques based on thickness of the fibrous cap and the area of lipid-rich core in the plaques. The proportion of unstable plaques were significantly higher in symptomatic group than in asymptomatic group (70.8% vs. 63.2%, P=0.026). Results of immunohistochemisty staining showed that the expression of NF-κB, CD68 and CD105 in unstable plaques was higher than stable plaques (P<0.001). The association of the higher expression of these factors with instability of carotid plaque needs to be clarified in future study.

Humanin and age-related diseases: a new link?

Humanin (HN) is 24-amino acid mitochondria-associated peptide. Since its initial discovery over a decade ago, a role for HN has been reported in many biological processes such as apoptosis, cell survival, substrate metabolism, inflammatory response, and response to stressors such as oxidative stress, ischemia, and starvation. HN and its potent analogs have been shown to have beneficial effects in many age-related diseases including Alzheimer's disease, stroke, diabetes, myocardial ischemia and reperfusion, atherosclerosis, amyotrophic lateral sclerosis, and certain types of cancer both in vitro and in vivo. More recently, an association between HN levels, growth hormone/insulin-like growth factor-1 (GH/IGF axis), and life span was demonstrated using various mouse models with mutations in the GH/IGF axis. The goal of this review is to summarize the current understanding of the role of HN in aging and age-related diseases.

CT assessment of liver hemodynamics in patients with hepatocellular carcinoma after argon-helium cryoablation

BACKGROUND

Assessment of tumor response after argon-helium cryoablation is critical in guiding future therapy for unresectable hepatocellular carcinoma. This study aimed to evaluate liver hemodynamics in hepatocellular carcinoma after argon-helium cryoablation with computed tomography perfusion.

METHODS

The control group comprised 40 volunteers without liver disease. The experimental group was composed of 15 patients with hepatocellular carcinoma treated with argon-helium cryoablation. Computed tomography perfusion parameters were measured: hepatic blood flow, hepatic blood volume, mean transit time, permeability of capillary vessel surface, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion.

RESULTS

After treatment, in the tumor foci, permeability of capillary vessel surface was higher, and hepatic blood flow, hepatic blood volume, hepatic arterial fraction, and hepatic arterial perfusion values were lower (P<0.05). In the liver parenchyma surrounding the tumor, hepatic arterial perfusion was significantly lower (P<0.05); however, there was no significant difference in hepatic blood flow, hepatic blood volume, mean transit time, permeability of capillary vessel surface, hepatic arterial fraction, or hepatic portal perfusion (P>0.05).

CONCLUSION

Computed tomography perfusion can evaluate tumor response after argon-helium cryoablation.

Expression of NF-κB, CD68 and CD105 in carotid atherosclerotic plaque

Atherosclerotic plaque vulnerability is associated with cerebrovascular events in patients with carotid atherosclerosis. The aim of this study was to investigate the expression of inflammatory factors in carotid artherosclerotic plaques in order to explore its clinical significance in patients with carotid stenosis. Forty three patients with carotid stenosis were divided into symptomatic group (n=24) and asymptomatic group (n=19) based on clinical manifestation. All patients were treated with selective standard carotid endarterectomy (CEA); the carotid atherosclerotic plaques were removed surgically and studied pathologically to investigate the expression of nuclear factor-kappa κ (NF-κB), CD68 and CD105. The plaques were grouped into stable and unstable plaques based on thickness of the fibrous cap and the area of lipid-rich core in the plaques. The proportion of unstable plaques were significantly higher in symptomatic group than in asymptomatic group (70.8% vs. 63.2%, P=0.026). Results of immunohistochemisty staining showed that the expression of NF-κB, CD68 and CD105 in unstable plaques was higher than stable plaques (P<0.001). The association of the higher expression of these factors with instability of carotid plaque needs to be clarified in future study.

Systematic review of randomized controlled trials of different types of patch materials during carotid endarterectomy

Background and Purpose

Carotid endarterectomy (CEA) with patch angioplasty produces greater results than with primary closure; however, there remains uncertainty on the optimal patch material in CEA. A systematic review of randomized controlled trials (RCTs) was performed to evaluate the effect of angioplasty using venous patch versus synthetic patch material, and Dacron patch versus polytetrafluoroethelene (PTFE) patch material during CEA.

Methods

A multiple electronic health database screening was performed including the Cochrane library, Pubmed, Ovid, EMBASE and Google Scholar on all randomized controlled trials (RCTs) published before November 2012 that compared the outcomes of patients undergoing CEA with venous patch versus synthetic patch. RCTs were included if they compared carotid patch angioplasty with autologus venous patch versus synthetic patch material, or compared one type of synthetic patch with another.

Results

Thirteen RCTs were identified. Ten trials, involving 1946 CEAs, compared venous patch with synthetic patch materials. Two trials, involving 400 CEAs in 380 patients, compared Dacron patch with PTFE patch. The hemostasis time in CEA with PTFE patch was significantly longer than with venous patch (P<0.0001), and longer than with Dacron patch (P<0.0001). There was no significant difference of mortality rate, stroke rate, restenosis, and operative time in CEA with venous patch versus synthetic patch material, or in CEA with Dacron patch versus PTFE patch (all P>0.05). One RCT of 95 CEAs in 92 patients compared bovine pericardium with Dacron patch, and demonstrated a statistically significant decrease in intraoperative suture line bleeding with bovine pericardium compared with Dacron patch (P<0.001).

Conclusions

The hemostasis time in CEA with PTFE patch was longer than with venous patch or Dacron patch. The overall perioperative and long-term mortality rate, stroke rate, restenosis, and operative time were similar when using venous patch versus synthetic patch material or Dacron patch versus PTFE patch material during CEA. More data are required to clarify differences between different patch materials.