Effects of association state on decocting rate of mangiferin in Pingfei Decoction by using low-field and high-field NMR / 中草药

Objective: To study the effects of association complexes on extraction and separation behavior of mangiferin in Pingfei Decoction by low-field and high-field NMR. Methods Using the T2 relaxation time and chemical shifts value of hydrogen as index, and group DNJ-citric acid as control, the relaxation characteristrics of hydrogen in association state was analyzed by low field NMR to verify the structure of association complexes combined with high-field NMR. Results DNJ and mangiferin existed in the form of association state with larger molecular weight, which inhibited the migration of components from medicinal materials to solution and caused lower transmittance. And the T2 peak shifted to the left in the spectrum, and the chemical shift in the high field nuclear magnetic field also changed. Conclusion This experiment clarified the mechanism of the effect of presence of components on extraction and separation behavior of mangiferin and provided technical support for studying the decocting method and mechanism of Chinese herbal compound.

Dual Component Analysis for In Vivo T₂* Decay of Hyperpolarized ¹³C Metabolites

PURPOSE: To investigate the exchange and redistribution of hyperpolarized ¹³C metabolites between different pools by temporally analyzing the relative fraction of dual T₂* components of hyperpolarized ¹³C metabolites. MATERIALS AND METHODS: A dual exponential decay analysis of T₂* is performed for [1-¹³C] pyruvate and [1-¹³C] lactate using nonspatially resolved dynamic ¹³C MR spectroscopy from mice brains with tumors (n = 3) and without (n = 4) tumors. The values of shorter and longer T₂* components are explored when fitted from averaged spectrum and temporal variations of their fractions. RESULTS: The T₂* values were not significantly different between the tumor and control groups, but the fraction of longer T₂* [1-¹³C] lactate components was more than 10% in the tumor group over that of the controls (P < 0.1). The fraction of shorter T₂* components of [1-¹³C] pyruvate showed an increasing tendency while that of the [1-¹³C] lactate was decreasing over time. The slopes of the changing fraction were steeper for the tumor group than the controls, especially for lactate (P < 0.01). In both pyruvate and lactate, the fraction of the shorter T₂* component was always greater than the longer T₂* component over time. CONCLUSIONS: The exchange and redistribution of pyruvate and lactate between different pools was investigated by dual component analysis of the free induction decay signal from hyperpolarized ¹³C experiments. Tumor and control groups showed differences in their fractions rather than the values of longer and shorter T₂* components. Fraction changing dynamics may provide an aspect for extravasation and membrane transport of pyruvate and lactate, and will be useful to determine the appropriate time window for acquisition of hyperpolarized ¹³C images.

T2 Relaxation Time Mapping of the Cartilage Cap of Osteochondromas

OBJECTIVE: Our aim was to evaluate the cartilage cap of osteochondromas using T2 maps and to compare these values to those of normal patellar cartilage, from age and gender matched controls. MATERIALS AND METHODS: This study was approved by the Institutional Review Board and request for informed consent was waived. Eleven children (ages 5-17 years) with osteochondromas underwent MR imaging, which included T2-weighted fat suppressed and T2 relaxation time mapping (echo time = 9-99/repetition time = 1500 msec) sequences. Lesion origins were femur (n = 5), tibia (n = 3), fibula (n = 2), and scapula (n = 1). Signal intensity of the cartilage cap, thickness, mean T2 relaxation times, and T2 spatial variation (mean T2 relaxation times as a function of distance) were evaluated. Findings were compared to those of patellar cartilage from a group of age and gender matched subjects. RESULTS: The cartilage caps showed a fluid-like high T2 signal, with mean thickness of 4.8 mm. The mean value of mean T2 relaxation times of the osteochondromas was 264.0 +/- 80.4 msec (range, 151.0-366.0 msec). Mean T2 relaxation times were significantly longer than the values from patellar cartilage (39.0 msec) (p < 0.0001). These findings were observed with T2 spatial variation plots across the entire distance of the cartilage cap, with the most pronounced difference in the middle section of the cartilage. CONCLUSION: Longer T2 relaxation times of the cartilage caps of osteochondromas should be considered as normal, and likely to reflect an increased water content, different microstructure and component.

The study of selective segmental renal artery clamping aggravating pathological injury of the solitary-kidney in a porcine model / 中华泌尿外科杂志

Objective To evaluate the effect of selective segmental renal artery clamping ( SSRAC) on the solitary-kidney, providing a foundamental basis for the using of SSRAC in partial nephrectomy. Methods A total of 18 pigs were randomized equally into 2 groups according to the method of renal artery clamping such as main renal artery clamping ( MRAC) group or SSRAC group.Each case underwent right radical nephrectomy and either MRAC or SSRAC for 60 minutes on the left kidney.Serum creatinine ( SCr) and blood urea nitrogen (BUN) were measured before surgery and at 6 time points thereafter (the 1st, 7th, 14th, 21st, 28th, 90th day).Magnetic resonance imaging was performed before surgery and at 4 time points thereafter (the 1st, 7th, 28th, 90th day) and T2 relaxation time and apparent diffusion coefficient (ADC) were determined.Inflammatory cell infiltration and interstitial fibrosis were detected using renal histology on the 1st and 90th day after operation.Results SCr and BUN of the two groups increased to peak value on the 1st day, and then decreased gradually to normal on the 90th day after the operation.On the 1st day, SCr [(266.43 ±31.12)umol/l] and BUN [(13.63 ±2.54)mmol/l)] of SSRAC group were significantly lower than that of MRAC [(386.37 ±40.40)umol/l,(26.83 ±5.96)mmol/l] (P0.05) on the 7th, 14th, 21st, 28th, 90th day.In the MRAC group, the T2 relaxation time of upper, middle and lower pole of the left kidney increased and the ADC decreased on the 1st day after operation.It arrived to the peak value on the 7th day, and decreased or increased respectively from then on to normal level on the 90th day.In the SSRAC group, there were no significant changes of T2 relaxation time and ADC in the upper and middle pole of left kidney (P>0.05), but it was similar to that in the MRAC group for lower pole.On the 1st, 7th, 28th day after operation, the T2 relaxation time of upper and middle pole of the left kidney in the MRAC group [(45.50 ±1.87),(51.82 ±2.27), and(40.37 ±1.93)ms ) ] were significantly higher than those in the SSRAC group [(36.67 ± 1.33),(35.15 ±1.27), and(37.48 ±1.37)ms](P0.05).On the 1st, 7th, 28th day after operation, the ADC of upper and middle pole of the left kidney in the MRAC group [(2.29 ±0.08) ×10 -3 mm2/s, (2.10 ±0.08) ×10 -3 mm2/s, (2.41 ±0.09) ×10 -3 mm2/s] were significantly lower than that of the SSRAC group [(2.69 ± 0.08) ×10 -3 mm2/s, ( 2.63 ±0.06 ) ×10 -3 mm2/s, ( 2.68 ±0.05 ) ×10 -3 mm2/s ] ( P <0.05 ) . However, on the 1st,7th, 28th, 90th day after operation, the ADC of lower pole of the left kidney in the SSRAC group [(1.93 ±0.08) ×10 -3mm2/s,(1.91 ±0.09) ×10-3mm2/s,(2.33 ±0.07) ×10 -3mm2/s, and (2.43 ±0.07) ×10 -3 mm2/s] were significantly lower than those of the MRAC group [ (2.37 ±0.05) ×10 -3 mm2/s, (2.06 ±0.07) ×10 -3 mm2/s, (2.46 ±0.09) ×10 -3 mm2/s, (2.61 ±0.08) ×10 -3 mm2/s](P<0.05).The whole left kidney in MRAC group experienced extensive tubular hydropic degeneration and limited inflammatory cell infiltration on the 1st day after operation.Moreover, renal tubular hydropic degeneration alleviated and no glomerular changes, fibrous tissue hyperplasia or inflammatory cell infiltration was found on the 90th day after operation.In SSRAC group, no changes were found in upper and middle pole of left kidney at the two time points, while the pathological injury of the lower pole of left kidney was more severe.Conclusions SSRAC has obvious protective effect on renal function in the early stage. However, compared with MRAC, the renal tissue injury in the ischemic area was more serious.Therefore, to protect renal function in partial nephrectomy, the ischemic renal area should be reduced as much as possible, even to zero-ischemic, when adopting SSRAC.

Quantitative Assessment of the T2 Relaxation Time of the Gluteus Muscles in Children with Duchenne Muscular Dystrophy: a Comparative Study Before and After Steroid Treatment

OBJECTIVE: To determine the feasibility of using T2 mapping as a quantitative method to longitudinally follow the disease activity in children with Duchenne muscular dystrophy (DMD) who are treated with steroids. MATERIALS AND METHODS: Eleven boys with DMD (age range: 5-14 years) underwent evaluation with the clinical functional score (CFS), and conventional pelvic MRI and T2 mapping before and during steroid therapy. The gluteus muscle inflammation and fatty infiltration were evaluated on conventional MRI. The histograms and mean T2 relaxation times were obtained from the T2 maps. The CFS, the conventional MRI findings and the T2 values were compared before and during steroid therapy. RESULTS: None of the patients showed interval change of their CFSs. On conventional MRI, none of the images showed muscle inflammation. During steroid treatment, two boys showed increased fatty infiltration on conventional MRI, and both had an increase of the mean T2 relaxation time (p < 0.05). The remaining nine boys had no increase in fatty infiltration. Of these, three showed an increased mean T2 relaxation time (p < 0.05), two showed no change and four showed a decreased mean T2 relaxation time (p < 0.05). CONCLUSION: T2 mapping is a feasible technique to evaluate the longitudinal muscle changes in those children who receive steroid therapy for DMD. The differences of the mean T2 relaxation time may reflect alterations in disease activity, and even when the conventional MRI and CFS remain stable.

Comparison of Proton T1 and T2 Relaxation Times of Cerebral Metabolites between 1.5T and 3.0T MRI using a Phantom

PURPOSE: To present the T1 and T2 relaxation times of the major cerebral metabolites at 1.5T and 3.0T and compare those between 1.5T and 3.0T. MATERIALS AND METHODS: Using the phantom containing N-acetyl aspartate (NAA), Choline (Cho), and Creatine (Cr) at both 1.5T and 3.0T MRI, the T1 relaxation times were calculated from the spectral data obtained with 5000 ms repetition time (TR), 20 ms echo time (TE), and 11 different mixing time (TM)s using STEAM (STimulated Echo-Acquisition Mode) method. The T2 relaxation times were obtained from the spectral data obtained with 3000 ms TR and 5 different TEs using PRESS (Point-RESolved Spectroscopy) method. The T1 and T2 relaxation times obtained at 1.5T were compared with those of 3.0T. RESULTS: The T1 relaxation times of NAA were 2293 +/- 48 ms at 1.5T and 2559 +/- 124 ms at 3.0T (11.6% increase at 3.0T). The T1 relaxation times of Cho were 2540 +/- 57 ms at 1.5T and 2644 +/- 76 ms at 3.0T (4.1% increase at 3.0T). The T1 relaxation times of Cr were 2543 +/- 75 ms at 1.5T and 2665 +/- 94 ms at 3.0T (4.8% increase). The T2 relaxation times of NAA were 526 +/- 81 ms at 1.5T and 468 +/- 74 ms at 3.0T (11.0% decrease at 3.0T). The T2 relaxation times of Cho were 220 +/- 44ms at 1.5T and 182 +/- 35 ms at 3.0T (17.3% decrease at 3.0T). The T2 relaxation times of Cr were 289 +/- 47 ms at 1.5T and 275 +/- 57 ms at 3.0T (4.8% decrease at 3.0T). CONCLUSION: The T1 relaxation times of the major cerebral metabolites (NAA, Cr, Cho), which were measured at the phantom, were 4.1%-11.6% longer at 3.0T than at 1.5T. The T2 relaxation times of them were 4.8%-17.3% shorter at 3.0T than at 1.5T. To optimize MR spectroscopy at 3.0T, TR should be lengthened and TE should be shortened.

The Measurement of Hippocampal T_2 Relaxation Time in Healthy Chinese and Its Influencing Factors / 实用放射学杂志

0.05).However,HCT2s of right side and left side were significantly negatively correlated to age(r=-0.606,-0.522;P=0.000,0.000).Conclusion HCT2s in healthy Chinese aged 10~59 year measured on SE dual echo images are quite stable,and age is an influencing factor of HCT2,but not side,sex and handedness.