Size and PEG Length-Controlled PEGylated Monocrystalline Superparamagnetic Iron Oxide Nanocomposite for MRI Contrast Agent.

OBJECTIVE: PEGylated superparamagnetic iron oxide (SPIO) is the most promising alternatives to gadolinium-based contrast agents (GBCAs) in MRI. This paper is to explore the imaging effects of PEGylated SPIO, which is influenced by particle sizes and surface polyethylene glycol (PEG) coating, using as MRI contrast agents at different magnetic field intensities. METHODS: Firstly, nine PEGylated monocrystalline SPIO nanoparticles with different nanocrystal sizes and different molecular weights PEG coating were prepared, and then physical and biological properties were analyzed. Finally, MRI imaging in vivo was performed to observe the imaging performance. RESULTS: Nine PEGylated monocrystalline SPIO nanoparticles have good relaxivities, serum stability, and biosecurity. At the same time, they show different imaging characteristics at different magnetic field intensities. Eight-nanometer SPIO@PEG5k is an effective T 2 contrast agent at 3.0 T (r 2/r 1 = 14.0), is an ideal T 1-T 2 dual-mode contrast agent at 1.5 T (r 2/r 1 = 6.52), and is also an effective T 1 contrast agent at 0.5 T (r 2/r 1 = 2.49), while 4-nm SPIO@PEG5k is a T 1-T 2 dual-mode contrast agent at 3.0 T (r 2/r 1 = 5.24), and is a useful T 1 contrast agent at 0.5 T (r 2/r 1 = 1.74) and 1.5 T (r 2/r 1 = 2.85). MRI studies in vivo at 3.0 T further confirm that 4-nm SPIO@PEG5k displays excellent T 1-T 2 dual-mode contrast enhancement, whereas 8-nm SPIO@PEG5k only displays T 2 contrast enhancement. CONCLUSION: PEGylated SPIOs with different nanocrystal sizes and PEG coating can be used as T 1, T 2, or T 1-T 2 dual-mode contrast agents to meet the clinical demands of MRI at specific magnetic fields.

Genetic Polymorphisms: A Novel Perspective on Acute Pancreatitis.

Acute pancreatitis (AP) is a complex disease that results in significant morbidity and mortality. For many decades, it has compelled researchers to explore the exact pathogenesis and the understanding of the pathogenesis of AP has progressed dramatically. Currently, premature trypsinogen activation and NF-κB activation for inflammation are two remarkable hypotheses for the mechanism of AP. Meanwhile, understanding of the influence of genetic polymorphisms has resulted in tremendous development in the understanding of the advancement of complex diseases. Now, genetic polymorphisms of AP have been noted gradually and many researchers devote themselves to this emerging area. In this review, we comprehensively describe genetic polymorphisms combined with the latest hypothesis of pathogenesis associated with AP.

Magnetic resonance imaging for pancreatic ductal adenocarcinomas induced by N-nitrosobis (2-oxopropyl) amine in Syrian golden hamsters.

OBJECTIVES: This study aimed to study magnetic resonance imaging (MRI) findings of pancreatic ductal adenocarcinomas (PDAs) induced by N-nitrosobis (2-oxopropyl) amine (BOP) in Syrian hamsters. METHODS: A total of 101 female hamsters, 8 weeks old, were randomized into 3 groups. They were randomized into a BOP-treated group (n = 80; with weekly subcutaneous injections of BOP [10 mg/kg body weight] for 7 consecutive weeks), a saline-treated group (n = 16), and an untreated group (n = 5). Hamsters underwent abdominal MRI on 1.5-T MR scanners with a dedicated animal radiofrequency coil. Findings of the tumor from the MRI were compared those from histology. RESULTS: Pancreata in the saline-treated and in the untreated groups were normal. In the BOP-treated group, there were 23 and 31 BOP-induced PDAs on macroscopy and microscopy, respectively. Of the PDAs detected on macroscopy, 65.2% were depicted on MRI. As early as 13 and 19 weeks after the first injection of BOP, PDAs in hamsters were found on histology and MRI, respectively. Moreover, the tumor volume on MRI was correlated with the tumor weights excised (r = 0.96, P = 0.000, n = 15). CONCLUSIONS: N-nitrosobis (2-oxopropyl) amine successfully induced PDAs in hamsters. Magnetic resonance imaging has the ability to detect healthy pancreas and PDAs in hamsters and has the potential to monitor the development of PDAs.

[PPARdelta + 294T/C gene polymorphism related to plasma lipid, obesity and left ventricular hypertrophy in subjects with metabolic syndrome].

OBJECTIVE: To investigate the relationship between PPARdelta + 294T/C gene polymorphism and lipid profile, obesity and left ventricular hypertrophy (LVH) in patients with metabolic syndrome (MS). METHODS: This study was conducted in 300 patients with MS and 174 patients with essential hypertension (EH) and 143 patients with type 2 diabetes mellitus (T2DM). MS was diagnosed according to 1999 WHO criteria. Fasting insulin (FINS), fasting blood glucose (FBG), plasma lipids levels were measured, LVH was examined by Doppler echocardiography. The PPARdelta + 294T/C gene polymorphism were analyzed using polymerase chain reaction and subsequently digested by BSLI restriction endonuclease. RESULTS: The frequencies of the PPARdelta + 294T/C genotypes were not different among three groups. Compared with T2DM and EH, MS patients had significantly higher body mass index (BMI), plasma total cholesterol, TG and LDL-C levels (P < 0.01 or P < 0.05). LVM, LVMI and incidence rate of LVH were significantly higher in MS and EH patients than that in T2DM (P < 0.01). MS patients with CC genotype had significantly higher total cholesterol and LDL-C levels than those with TT and TC genotypes (total cholesterol in CC genotype: 6.13 +/- 1.86 mmol/L vs in TC genotype: 5.14 +/- 1.10 mmol/L, P < 0.05, and CC genotype: 6.13 +/- 1.86 mmol/L vs TT genotype: 4.99 +/- 1.42 mmol/L, P < 0.01; LDL-C in CC genotype: 3.82 +/- 1.52 mmol/L vs in TC genotype: 3.14 +/- 0.88 mmol/L, P < 0.05, and in CC genotype: 3.82 +/- 1.52 mmol/L vs in TT genotype: 2.90 +/- 0.87 mmol/L, P < 0.01). BMI and LVMI in MS patients with C allele carriers (CC + TC) were significantly higher than that of TT genotype (LVMI in CC + TC: 46 +/- 10 g/m(2.7) vs in TT: 44 +/- 10 g/m(2.7); BMI in CC + TC: 26 +/- 3 kg/m(2) vs in TT: 25 +/- 3 kg/m(2), P < 0.05). CONCLUSIONS: It is indicated that PPARdelta + 294T/C gene polymorphism in subjects with MS may be involved in the occurrence of obesity and dyslipidemia. MS patients with C allele had a predominant LVH than subjects with TT genotype.

[Peroxisome proliferator-activated receptor gamma C-161T polymorphism and carotid artery atherosclerosis in metabolic syndrome].

OBJECTIVE: To assess the relationship between PPAR gamma C161-T polymorphism and Carotid Atherosclerosis in metabolic Syndrome (MS). METHODS: Polymerase chain reaction-restricted fragments length polymorphism was used to study the distribution of the PPAR gamma C161-T polymorphism in 248 metabolism syndrome, 163 essential hypertension (EH) and 115 type 2 diabetes mellitus (DM) patients and 121 normal controls. Fasting insulin (FINS), fasting blood glucose (FBG), uric Acid (UA), plasma lipids and ultrasonography for carotid artery were examined. RESULTS: Waistline and BMI were significantly higher in MS compared with those in control, EH and DM (P < 0.01). systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were markedly higher in MS and EH compared with those in DM and control (P < 0.01). The frequencies of the CC, CT and TT were 74.6%, 21.8% and 3.6% in MS respectively, The frequencies of the CC was significantly higher in MS compared with that in control, but T allele carrier (CT + TT) was significantly lower compared with control, DM and EH (P < 0.05 or P < 0.01). In MS, CC genotype had significantly increased the intima-media thickness (IMT) of common carotid artery and plaque index compared with CT + TT (IMT: 0.84 mm +/- 0.3 mm vs 0.66 mm +/- 0.19 mm; plaque index: 2.19 +/- 1.21 vs 1.66 +/- 1.36, P < 0.05), CC genotype had significantly increased plaque index compared with CT + TT in EH and DM (plaque index: EH: 1.55 +/- 1.23 vs 1.29 +/- 0.92; DM: 1.57 +/- 1.2 vs 1.18 +/- 0.85, P < 0.05); CC genotype had significantly higher SBP compared with CT + TT in EH (P < 0.05), CC genotype had significantly increased plaque index in MS than that in DM and EH (P < 0.01), CC genotype had significantly increased IMT in MS compared with DM. CC genotype had significantly higher SBP and PP compared with CT + TT in MS (SBP: 155 mm Hg +/- 23 mm Hg vs 145 mm Hg +/- 21 mm Hg; PP: 69 mm Hg +/- 8 mm Hg vs 58 mm Hg +/- 8 mm Hg, 1 mm Hg = 0.133 kPa, P < 0.05). CONCLUSION: In MS, CC genotype was prone to lesion of carotid artery, but CT + TT may reduce lesion of carotid artery, which implicates that PPAR gamma C161-T may play a important role in carotid artery arteriosclerosis.