Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field.
Angiography ; Arteries/anatomy & histology ; Contrast Media/*chemistry ; Gadolinium DTPA/*chemistry ; Humans ; Liver/*radiography ; *Magnetic Resonance Imaging

The aim of this study was to investigate the inhibitory effect of heparin/fibronectin (Hep/Fn) complexes on neointimal hyperplasia following endovascular intervention. Hep/Fn complexes were immobilized onto titanium (Ti) surfaces, with subsequent X-ray photoelectron spectroscopy (XPS), Toluidine Blue O (TBO) and immunohistochemistry methods were used to characterize surface properties. Smooth muscle cell (SMC) cultures were used to evaluate the effect of Hep/Fn complexes on SMC proliferation. Results showed that Hep/Fn complexes successfully immobilized onto Ti surfaces and resulted in an inhibition of SMC proliferation. This study suggests that Hep/Fn surface-immobilized biomaterials develop as a new generation of biomaterials to prevent neointimal hyperplasia, particularly for use in cardiovascular implants.
Biocompatible Materials ; Cell Proliferation ; drug effects ; physiology ; Cells, Cultured ; Fibronectins ; chemistry ; pharmacology ; Heparin ; chemistry ; pharmacology ; Humans ; Immobilized Proteins ; chemistry ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; physiology ; Surface Properties ; Titanium ; chemistry ; Umbilical Arteries

BACKGROUND AND OBJECTIVES: Late coronary in-stent restenosis remains an important clinical problem in coronary intervention. The effects of Paclitaxel (Taxol), an antimicrotubule agent, on neointimal proliferation within porcine coronary arteries were evaluated. METHOD: Stent overdilation injury was performed in porcine coronary arteries without local delivery of paclitaxel (n=10, Group I). Stent overdilation injury was also performed after local delivery of paclitaxel nanoparticle using the Dispatch Catheter(TM) in other coronary arteries (n=10, Group II). Coronary angiography and histopathologic examinations, which were performed 4 weeks after stenting, and complete blood counts and blood chemistry before and 4 weeks after the local delivery were compared. RESULT: 1) Reference vessel diameter, stented artery diameter, and diameter stenosis were not different between two groups. 2) Histopathologic injury score, external elastic lamina area, internal elastic lamina area, and luminal area were not different between two groups. 3) Neointimal area and histopathologic area stenosis were smaller significantly in the group II than in group I (2.3+/-0.33 vs 3.7+/-1.40 mm2, 22.2+/-19.26 vs 31.1+/-7.15%: p=0.04, 0.03, respectively). 3) Proliferating cell nuclear antigen index was lower in the stent overdilation injury with local paclitaxel delivery group than in the stent overdilation injury alone (31.10+/-3.70 vs 46.80+/-5.20%, p=0.04). 4) No significant laboratory changes were observed before and 4 weeks after the local delivery. CONCLUSION: Local delivery of paclitaxel nanoparticle inhibits neointima formation after stent overdilation injury in porcine coronary arteries without systemic toxicity.
Arteries ; Blood Cell Count ; Chemistry ; Constriction, Pathologic ; Coronary Angiography ; Coronary Vessels ; Nanoparticles* ; Neointima ; Paclitaxel* ; Phenobarbital ; Proliferating Cell Nuclear Antigen ; Stents*

Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI.
Arteries/chemistry ; Brain Neoplasms/radiography ; Contrast Media/diagnostic use ; Humans ; Magnetic Resonance Imaging/standards/*trends ; Spin Labels ; Stroke/radiography

OBJECTIVETo investigate the early prognostic values of arterial lactate and base excess (BE) in patients with paraquat poisoning.

METHODSSeventy-five patients with paraquat poisoning were divided into sudden death group (n = 10) who died within 24 h after admission, recent death group (n = 31) who died more than 24 h after admission, and survival group (n = 34). Arterial lactate and BE were measured on admission and at 24 h after admission. The prognostic values of arterial lactate and BE were analyzed.

RESULTSThe arterial lactate measured on admission was significantly higher in the sudden death group than in the recent death group and survival group (P < 0.01), but there was no significant difference in arterial lactate between the recent death group and survival group (P = 0.309). The BE measured on admission was significantly lower in the sudden death group than in the recent death group and survival group, and it was significantly lower in the recent death group than in the survival group (P < 0.01 or P < 0.05). At 24 h after admission, the recent death group had a significantly higher arterial lactate (P < 0.01) and a significantly lower BE (P < 0.01), as compared with the survival group. The logistic regression analysis showed that the two indices were significantly associated with prognosis (P < 0.01). On admission, the areas under the receiver operating characteristic (ROC) curve (AUCs) of arterial lactate and BE for predicting death were 0.692 and 0.787, respectively, and the cut-off values were 3.25 mmol/L and -1.75 mmol/L, respectively; the AUCs of arterial lactate and BE for predicting sudden death were 0.995 and 1, respectively, and the cut-off values were 7.1 mmol/L and -12.8 mmol/L, respectively. At 24 h after admission, the AUCs of arterial lactate and BE for predicting death were 0.743 and 0.822, respectively, and the cut-off values were 2.15 mmol/L and -5.55 mmol/L, respectively.

CONCLUSIONArterial lactate and BE have certain values in predicting the death, especially the sudden death, in patients with acute paraquat poisoning.

Adult ; Aged ; Arteries ; chemistry ; Female ; Humans ; Lactic Acid ; blood ; Male ; Middle Aged ; Paraquat ; poisoning ; Poisoning ; diagnosis ; Prognosis

Acid-Base Equilibrium ; Apgar Score ; Blood Gas Analysis ; Fetal Blood ; chemistry ; Fetal Monitoring ; Humans ; Infant, Newborn ; Reference Values ; Umbilical Arteries

Effects of pH on vascular tone and L-type Ca2+ channels were investigated using Mulvany myograph and voltage-clamp technique in rabbit basilar arteries. In rabbitbasilar arteries, high K+ produced tonic contractions by 11+/-0.6 mN (mean+/-S.E., n=19). When extracellular pH (pHo) was changed from control 7.4 to 7.9 ([alkalosis]o), K+-induced contraction was increased to 128+/-2.1% of the control (n=13). However, K+-induced contraction was decreased to 73+/-1.3% of the control at pHo 6.8 ([acidosis]o, n=4). Histamine (10 micrometer) also produced tonic contraction by 11+/-0.6 mN (n=17), which was blocked by post-application of nicardipine (1 micrometer). [alkalosis]o and [acidosis]o increased or decreased histamine-induced contraction to 134+/-5.7% and 27+/-7.6% of the control (n=4, 6). Since high K+- and histamine-induced tonic contractions were affected by nicardipine and pHo, the effect of pHo on voltage-dependent L-type Ca2+ channel (VDCCL) was studied. VDCCL was modulated by pHo: the peak value of Ca2+ channel current (IBa) at a holding of 0 mV decreased in [acidosis]o by 41+/-8.8%, whereas that increased in [alkalosis]o by 35+/-2.1% (n=3). These results suggested that the external pH regulates vascular tone partly via the modulation of VDCC in rabbit basilar arteries.
Animals ; Arteries/*pathology ; Basilar Artery/*pathology ; Calcium/metabolism ; Calcium Channels/chemistry ; Electrophysiology ; Histamine/chemistry/metabolism ; Hydrogen-Ion Concentration ; Muscle Cells/cytology ; Muscle Contraction ; Muscle, Smooth/*pathology ; Patch-Clamp Techniques ; Potassium/chemistry/metabolism ; Rabbits ; Stress, Mechanical ; Time Factors

The purpose of this study was to determine the effect of twin-to-twin delivery interval on umbilical artery acid-base status of the second twin at birth. This was a retrospective cohort study of all live-born twins with measured acid-base status in umbilical arterial blood who were delivered after 34 weeks' gestation from June 2003 to February 2006. Twins with any maternal or fetal complications were excluded. Subjects were divided into two groups based on the mode of delivery of the first twin: normal cephalic vaginal deliveries (n=40) or cesarean deliveries (n=67). The inter-twin differences in umbilical arterial blood pH, PCO2, PO2, and base excess in twin newborns born vaginally were significantly greater than the corresponding differences in those born by cesarean section. A significant positive correlation was found between twin-to-twin delivery interval and inter-twin difference in umbilical arterial blood pH in twin newborns born vaginally. The umbilical arterial blood pH of the second twin was less than 7.0 in 14% (2/14) in cases delivered more than 20 min after the first twin. The umbilical arterial blood gas status of the second twin worsened with increasing twin-to-twin delivery interval, and pathologic fetal acidemia (pH<7.0) might develop in the second twin when the twin-to-twin delivery interval was greater than 20 min.
Umbilical Arteries/*chemistry ; Twins/*blood ; Time Factors ; Statistics ; Retrospective Studies ; Infant, Newborn ; Hydrogen-Ion Concentration ; Humans ; Delivery, Obstetric/*methods ; Cohort Studies ; *Acid-Base Equilibrium

OBJECTIVETo observe the hypotensive effects of Qindan Capsule (QC) on spontaneous hypertensive rats (SHR) and its effect on the contents of endothelin (ET), calcitonin gene-related peptide (CGRP) and angiotensin-II (Ang-II ) in plasma and vascular tissues, and to investigate the possible mechanism of QC in lowering blood pressure.

METHODSForty SHRs were divided into 5 groups: the high dosage QC group [QCHD, 750 mg/(kgxd)], the low dosage QC group [QCLD, 150 mg/(kgxd) ], the Niuhuang Jiangya Pill group [NJP, 200 mg/(kgxd) ], the Captopril group [ 15 mg/(kg d) land the model group, 8 in each group. Meanwhile, a normal control group consisting of 8 Wistar-Kyoto (WKY) rats was set up also. All the rats were administered with medicine through gastrogavage. Systolic blood pressure (SBP), level of ET, CGRP and Ang-II in plasma and Ang-II in tissues of mesenteric artery were detected in all the rats after 12 weeks of treatment.

RESULTSThe level of SBP after treatment in the QCHD group was lower than that in the model group (P<0.01), but with no significant difference as compared with that in the Captopril group and the NJP group (P>0.05). After treatment, the plasma level of ET was lower and CGRP higher than those in the model group (both P<0.05), and also higher than those in the NJP and Captopril group (both P<0.05). As for the content of Ang-II , in mesenteric arterial tissues, it was lower in the QCHD group than that in the model group ( P<0.05), but in plasma, it showed no significant difference between the two groups (P>0.05).

CONCLUSIONQC has a satisfactory hypotensive action on SHR rats, and its mechanism may be associated with the regulation on plasma vasoactive peptide and regional renin-angiotensin system.

Angiotensin II ; blood ; Animals ; Blood Pressure ; drug effects ; Calcitonin Gene-Related Peptide ; blood ; Capsules ; Endothelins ; blood ; Hypertension ; blood ; drug therapy ; physiopathology ; Male ; Medicine, Chinese Traditional ; Mesenteric Arteries ; chemistry ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

Lipid accumulation in the vessel wall and tunica intima vasorum pathological changes are important factors in the development of atherosclerosis, which are closely related with hemodynamics. In this paper, we established a model of local low shear stress in rabbits using carotid artery cannula and a high cholesterol diet for 2 weeks, 4 weeks and 8 weeks. The effects of Shenlian extract on blood flow, vascular pathology formation and lipid metabolism were assessed by electromagnetic blood flow meter and hematoxylin-eosin staining of the proximal end in carotid artery at different times. The results demonstrate that the relationship between blood flow and shear stress for control, atorvastatin, Shenlian extract high-dose, Shenlian extract middle-dose, and Shenlian extract low-dose were linearly related. The blood flow and the shear stress of proximal end in carotid artery of Shenlian extract (1.12, 2.24, 4.48 g x kg(-1)), and atorvastatin (4.7 x 10(-4) g x kg(-1)) were significantly (P < 0.05)increased compared with the control. Plasma total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) ,and high density lipoprotein cholesterol (HDL-C) were markedly decreased with the increasing of dose and time. This study is the first to prove that the inhibition of Shenlian extract on low shear stress (LSS) induces rabbits carotid atherosclerosis with increasing blood flow and decreasing lipids and vessel pathological changes.
Animals ; Biomechanical Phenomena ; Blood Flow Velocity ; drug effects ; Carotid Arteries ; chemistry ; drug effects ; pathology ; physiopathology ; Carotid Artery Diseases ; drug therapy ; pathology ; physiopathology ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Male ; Rabbits ; Stress, Mechanical