Quantification of fat infiltration in the sacroiliac joints with ankylosing spondylitis using IDEAL sequence.

AIM: To quantitatively assess fat infiltration in the sacroiliac joints (SIJs) of patients with ankylosing spondylitis (AS) by measuring the fat/water signal ratios of periarticular bone marrow with iterative decomposition of water and fat with echo asymmetry and least square estimation (IDEAL). MATERIALS AND METHODS: Routine SIJ magnetic resonance imaging (MRI) and IDEAL were performed on 40 patients with AS and 30 healthy subjects. The fat infiltration regions (FIRs) and normal-appearing regions (NARs) of patients were measured based on the fat/water signal intensity on IDEAL. RESULTS: AS patients had higher fat/water signal ratios on FIRs and NARs (65.4-85.4%, p<0.05, and 44.1-70.7%, p<0.05, respectively) compared to healthy controls (38.3-43.3%). After treatment, the fat/water signal ratios of FIRs and NARs decreased (42.1-53.7% and 41.5-50.3%, respectively), but they remained higher than in the healthy controls (p<0.05). The fat infiltration was detected more effectively with a fat fraction map of the IDEAL sequence (95%) than other sequences, including the T1-weighted sequence (65%), and the fat/water signal ratios of the sacrum and ilium between the left and right sides of SIJs were approximately the same. CONCLUSION: The findings of this study suggest that IDEAL may be useful as a quantitative and objective method for evaluating the fat infiltration in the periarticular bone marrow of SIJs with AS; additionally, the sensitivity of IDEAL is better than that of routine sequences in detecting micro-fat infiltration of SIJs, and IDEAL can be used to quantitatively measure the adipose content and monitor patient follow-up after AS treatment.

Aptamer-modified PLGA nanoparticle delivery of triplex forming oligonucleotide for targeted prostate cancer therapy.

Presented study aimed to prepare A10 aptamer-modified poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles loaded with triplex forming oligonucleotides(TFO) for targeted prostate cancer therapy. We first synthesized a PLGA-PEG-Apt copolymer. The PLGA-PEG-Apt nanoparticles (NP-Apt) were loaded with TFO using double emulsion solvent evaporation method. Carboxy-fluorescein labeled TFO-NP-Apt, TFO-NP and TFO were prepared for cellular uptake experiments. Cell counting kit-8 (CCK-8) test was used to determine the ability of TFO-NP-Apt to inhibit LNCaP cell proliferation. RT-PCR and Western blot was conducted to analyze AR gene expressing. Then, a mouse model of prostate cancer was used to evaluate the anti-cancer effect of TFO-NP-Apt in vivo. We confirmed that the PLGA-PEG-Apt conjugation was successful. The TFO encapsulation efficiency and drug loading percentage were 46.1± 3.6% and 40.8±5.3%, respectively. TFO-NP-Apt showed a more efficient cellular uptake than TFO-NP or TFO in LNCaP cells. TFO-NP-Apt was significantly more cytotoxic than TFO-NP and TFO in the CCK-8 test (p<0.001). TFO-NP-Apt silenced the AR gene better than unconjugated Apt, naked TFO, NP or saline. TFO-NP-Apt were more effective than TFO-NP, naked TFO, NP and saline at inhibiting prostate cancer growth in vivo (p<0.05). Aptamer-modified TFO-loaded PLGA nanoparticles may prove useful in targeted therapy for advanced prostate cancer.

[Microscopic observation of the enamel microstructures of SD rats with different degrees of fluorosis].

Objective: To establish a dental fluorosis model of SD rats with various degrees, to observe the microstructures of enamel samples under scanning electron microscope and to clarify the changes of enamel microstructures with various degrees of dental fluorosis, so as to provide clinical reference for the treatment of patients with moderate and severe dental fluorosis. Methods: Thirty male SD rats (6 weeks of age) were randomly divided into 3 groups with 10 rats in each group. The control group was fed with deionized water without fluoride, the low fluoride group was fed with 50 mg/L NaF deionized water and the high fluoride group was fed with 100 mg/L NaF deionized water in order to establish the dental fluorosis model of rats. After feeding for 6 weeks, the rats were sacrificed and the mandibular incisor teeth were collected and recorded. The surface and sagittal plane of each tooth were observed by scanning electron microscopy and the enamel thickness was measured. Results: In the control group, the enamel color was brown yellow. Enamel color discoloration occurred both in low-fluoride group and high-fluoride group. The enamel color in low-fluoride group was mostly yellow and white striped while in high-fluoride group was mostly chalky white. Under electronic microscope, the enamel rods were alternately arranged and their structure was clear and plump in the control group. The enamel rods of moderate fluorosis were arranged in a straight orientation like tips of bamboo shoots. The enamel rods of severe fluorosis, however, became thinner and the tips of rods were broken. In the control group, sagittal images of enamel turned out to be a dense outer structure with clear boundaries among the inner. The structure of the middle layer was reticulated showing a clear boundary with middle and outer layers. The structure of enamel rods in the inner layers was arranged vertically and horizontally. In the moderate fluorosis group, the outer layer of the enamel became thinner and the middle layer disappeared although the boundary between the outer and middle layers was still clear. In the inner layer, the vertically arranged enamel rods seemed still clear, however the horizontal enamel rods disappeared. In the severe fluorosis group, the outer layer could not be traced. The middle layer was exposed to the air and the inner enamel rods contracted. The inner layers of the enamel had gradually become thinner with the development of the dental fluorosis. The thicknesses of inner layers in control, moderate and the severe groups were (180.71±7.01), (157.10±11.04) and (121.10±12.56) µm respectively. As for the thicknesses of the full layers in the above mentioned three groups, the same trend was observed. The thicknesses, in order of the severity of dental fluorosis, were (241.54±7.76), (207.42±14.36) and (143.79±14.60) µm. Conclusions: With the development of dental fluorosis, the outer enamel layers became thinner or disappeared and the inner enamel layers became thinner or lost its normal structure as well. It is highly recommended that the resin penetration could be used for the proper treatment of moderate and severe dental fluorosis and the strong bleaching and the micro-grinding should be used cautiously.

A stable focal cerebral ischemia injury model in adult mice: assessment using 7T MR imaging.

BACKGROUND AND PURPOSE: A stable stroke experimental model is highly desirable for performing longitudinal studies using MR imaging. The purpose of this study is to establish a stable focal cerebral ischemia model with a high survival rate in adult mice. MATERIALS AND METHODS: One hundred twenty adult mice were randomly divided into 10 groups of 12 each to respectively undergo intraluminal suture occlusion, with suture insertion depths from 0.8 cm to maximum; thromboembolic occlusion; and hypoxic-ischemic injury with hypoxia exposure times from 30-120 minutes. Coronal brain T2-weighted images were obtained on a 7T scanner. The induced infarct volume and location were assessed and correlated with histologic TTC staining. One-day and 7-day survival rates were recorded. RESULTS: The infarct location was highly variable in the thromboembolic model, while it showed a cortex predominance in the intraluminal model with the suture insertion depth ≥1.4 cm, and the HI model with hypoxia exposure times ≥60 minutes (P = .001). The infarct volume in the intraluminal model with suture depths ≥1.4 cm (29.7 ± 3.3%, 35.4 ± 4.3%) and the HI model with the hypoxia exposure times ≥90 minutes (26.3 ± 4.1%, 33.4 ± 2.8%) were larger than other groups (9.7 ± 3.3%-20.9 ± 9.3%; P < .05). The HI group (72.5%) had higher 7-day survival rate than the intraluminal suture occlusion (28%) and thromboembolic occlusion groups (20%; P = .001). CONCLUSIONS: The HI injury model with a reproducible ishemia and high survival rate can be used for a longitudinal study of brain ischemia in adult mice.