[Experimental study on evaluating renal redox metabolism in renal ischemia-reperfusion injury using GluCEST imaging with 3.0 T MRI].

Objective: To investigate the feasibility of 3.0 T glutamate chemical exchange saturation transfer (GluCEST) imaging in evaluating renal redox metabolism in renal ischemia-reperfusion injury (IRI). Methods: Rabbits in the IRI group (n=56) underwent surgery by clamping the left renal artery for 45 min and then releasing to establish IRI. Rabbits in the sham group (n=8) underwent the same operation without clamping the left renal artery. GluCEST MRI was performed before and at 1 h, 12 h, 1 day, 3 days, 7 days, and 14 days after the operations, with eight rabbits in the IRI group sacrificed immediately after each scanning and eight in the sham group sacrificed at 14 days after scanning. The left kidneys were removed for histopathological examination and reactive oxygen species (ROS) fluorescence staining. Differences in the magnetic resonance ratio asymmetry (MTRasym) of the renal cortex and outer medulla among different groups were compared. Correlations between the MTRasym and ROS were analyzed. Results: The MTRasym of the renal cortex in the sham and IRI subgroups were higher than that of the outer medulla (t=8.16, P<0.001; t=4.78, P=0.002; t=4.94, P=0.002; t=5.76, P=0.001, t=6.68, P<0.001; t=6.40, P<0.001; t=5.16, P=0.001; t=3.30, P=0.013). The MTRasym of the renal cortex and outer medulla in the IRI-1h, IRI-12h, IRI-1d, IRI-3d, IRI-7d, and IRI-14d groups were lower than in the sham and IRI-pre groups (all P<0.05). The MTRasym of the renal cortex and outer medulla in the IRI-1h group were lower than in the IRI-12h, IRI-1d, IRI-3d, IRI-7d, and IRI-14d groups (all P<0.05). The MTRasym of the renal cortex in the IRI-12h group was lower than in the IRI-7d and IRI-14d groups (1.84%±0.09% vs.2.42%±0.19%, 2.41%±0.31%, all P<0.05). The MTRasym of the renal cortex in the IRI-1d group was lower than in the IRI-7d group (1.99%±0.17% vs. 2.42%±0.19%, P=0.008). The MTRasym of the outer medulla in the IRI-12h group was lower than in the IRI-3d, IRI-7d, and IRI-14d groups (1.32%±0.27% vs. 1.79%±0.31%, 1.98%±0.18%, 1.66%±0.40%, respectively, all P<0.05]. The MTRasym of the outer medulla in the IRI-7d group was higher than in the IRI-1d and IRI-14d groups (1.98%±0.18% vs. 1.52%±0.31%, 1.66%±0.40%, all P<0.05). The MTRasym of the renal cortex and outer medulla had a strong negative correlation with the mean fluorescence intensity of ROS (ρ=-0.889, P<0.001; ρ=-0.784, P<0.001). Conclusion: 3.0 T GluCEST imaging can indirectly reflect the changes of renal redox metabolism in renal IRI.

[Young mammary Paget's disease patients with underlying breast invasive ductal carcinoma: clinicopathological features and prognosis].

Objective: To investigate the clinicopathological factors and prognostic status of young Mammary Paget's disease (MPD) patients with invasive ductal carcinoma (IDC). Methods: In this study, we defined the age at diagnosis below 40 years old as young patients, and retrospectively analyzed data from 123 MPD-IDC patients who were admitted at the Cancer Hospital Chinese Academy of Medical Sciences from June 2002 to February 2019. Patients were divided into the young group (≤40 years old, 15 cases) and the old group (>40 years old, 108 cases) according to the age of onset, and the clinicopathological characteristics and prognosis of the two groups were compared. Cox regression model analysis was used to analyze the prognosis influencing factors. Results: The proportions of patients in the young group with non-menopausal, axillary lymph node metastasis, and Ki-67 index ≥15% were 93.3% (14/15), 73.3% (11/15), and 86.7% (13/15), respectively, which were higher than those in the old group [45.4% (49/108), 39.8%(43/108), and 60.2% (65/108), respectively] , with statistically significant differences (P<0.05). At an average follow-up of 63.2 months, patients in the young group had a significantly shorter disease-free survival (DFS) compared with that of the old group (P=0.012), while the difference in overall survival (OS) between the two groups was not statistically significant (P=0.161). Multifactorial Cox regression analysis showed that axillary lymph node status was an independent influencing factor on OS (HR=3.339, 95% CI: 1.121-9.943) in patients with MPD-IDC, while age was not. Conclusion: Compared with the old group, young patients with MPD-IDC have a higher incidence of axillary lymph node metastasis, high Ki-67 expression, and a shorter DFS, but age is not an independent influencing factor on DFS or OS in patients with MPD-IDC.

Short communication: A decrease in diameter of milk fat globules accompanies milk fat depression induced by conjugated linoleic acid supplementation in lactating dairy cows.

Milk fat is secreted from the mammary gland in the form of milk fat globules (MFG). Although milk fat depression has been studied since the beginning of the last century, the extent to which this phenomenon alters MFG synthesis is not fully understood. The aim of this study was to evaluate the effect of conjugated linoleic acid (CLA) on the size and distribution of MFG during milk fat depression in dairy cows. Twelve Holstein cows in mid lactation (145 ± 31 d in milk, 583 ± 34.6 kg of body weight, and 27.2 ± 2.4 kg of milk/d) were randomly assigned to a control diet or control plus Ca-protected CLA at 15 g/kg of dry matter for a 6-d period. The average diameter and particle size distribution of MFG were measured using a Mastersizer 3000 laser particle size analyzer (Malvern Instruments Ltd., Malvern, UK). Feeding CLA did not affect dry matter intake (16.2 ± 0.4 kg/d), milk production (28.4 ± 0.4 kg/d), milk protein, or lactose, but it decreased milk fat content (3.46 vs. 2.52%). In addition, surface area-related mean diameter of fat globules in cows fed CLA was lower compared with controls (3.02 vs. 3.45 µm). The percentage of large fat globules decreased and that of small fat globules increased in response to CLA. Overall, the data suggest that the milk fat depression induced by CLA is accompanied by a decrease in average diameter of MFG.

[Value of magnetic resonance imaging texture analysis in evaluating renal allograft injury].

Objective: To explore the value of magnetic resonance imaging (MRI) texture analysis in evaluating renal allograft injury. Methods: A retrospective review was performed on sixty-six patients who underwent allograft renal transplantation (42 males, 24 females; age range, 22-63 years; mean age, (40±10) years) between November 2013 and December 2016. All the patients were divided into three groups according to their eGFR on the day of MRI examination: normal renal allograft function (nRAF) group (n=15), mild to moderate renal allograft injury (mRAI) group (n=18), and severe renal allograft injury (sRAI) group (n=33). All the patients underwent conventional T(2) weighted image (T(2)WI), susceptibility weighted imaging (SWI), and blood-oxygen level dependent (BOLD) MRI examination. MRI texture features of renal allograft were extracted. The texture features based on T(2)WI, SWI, and BOLD with absolute correlation coefficient of eGFR greater than or equal to 0.3 (P<0.05)and also with the highest Z value for Boruta algorithmwere selected. The diagnostic performance of the selected texture features in differentiating the three groups was assessed by receiver operating characteristic (ROC) curve analysis. Results: T(2)WI_Perc.50%, SWI_Perc.01%, BOLD_S(4,4)Contrast, and BOLD_S(5,5)Correlat with absolute correlation coefficient of eGFR greater than or equal to 0.3 (P<0.05) and also with the highest Z value for Boruta algorithm were selected. The AUC for T(2)WI_Perc.50%, SWI_Perc.01%, and BOLD_S(5,5)Correlat in differentiating the nRAF group with the mRAI group was 0.785, 0.720, and 0.700. The AUC for T(2)WI_Perc.50%, SWI_Perc.01%, BOLD_S(4,4)Contrast, and BOLD_S(5,5)Correlat in differentiating the nRAF group with the sRAI group was 0.687, 0.733, 0.784, and 0.737.The AUC for BOLD_S(4,4) Contrast in differentiating the mRAI group with the sRAI group was 0.667. Conclusion: MRI texture analysis can provide valuable information for evaluating renal allograft injury.

[Study on the causes, prevention and treatment of complications after transsphenoidal pituitary tumor resection under neuroendoscope].

Objective: To analyze the causes of complications after endoscopic transsphenoidal pituitary adenoma resection and summarize the corresponding prevention and treatment measures. Methods: The pathological data of 120 patients with pituitary adenoma in hospital were analyzed retrospectively. All patients were treated surgically, five kinds of common complications were collected, the risk factors of complications were statistically analyzed, the causes of postoperative complications were determined, and then the specific prevention and treatment strategies were summarized. Results: Long operation time (P<0.05), hypopituitarism before operation (P<0.01) and large tumor (P<0.01) were the main inducing factors of CSF rhinorrhea after operation; long operation time (OR=1.394, P<0.01), lumbar cistern puncture (OR=1.531, P<0.01) and CSF rhinorrhea after operation (OR=3.861, P<0.01) were the independent risk factors of infection; Age, large tumor and preoperative hypophysis are the main factors of postoperative hypophysis; Postoperative hypophysis and intraoperative cerebrospinal fluid rhinorrhea are the main factors of postoperative diabetes insipidus; Postoperative hypophysis and giant adenoma are the main factors of postoperative hyponatremia. Conclusion: Endoscopic transnasal transsphenoidal resection of pituitary adenoma is the most minimally invasive method at present. There are still risk factors for postoperative complications. Targeted prevention of risk factors for complications and corresponding interventions can effectively reduce the incidence of postoperative complications of pituitary adenoma.

[Feasibility of using blood oxygen level-dependent magnetic resonance imaging to evaluate renal fibrosis of ureteral obstruction of rabbits].

Objective: To investigate the feasibility of blood oxygen level-dependent MR (MR-BOLD) in assessing renal fibrosis of ureteral obstruction of rabbits. Methods: Forty healthy New Zealand rabbits were randomly divided into control group (n=8) and unilateral ureteral obstruction (UUO) group (n=32). The rabbits in the UUO group were subjected to unilateral ureteral obstruction of the left kidney.Coronal T(2) weighted imaging (T(2)WI) and axial BOLD examinations were performed before operation, 2, 4, 6 and 8 W after operation (each subgroup n=8). After the examinations, nephrectomy was performed for histologic evaluation.The T(2)(*) relaxation rate of the renal cortex (CR(2)(*)) , medulla (MR(2)(*)) and the same level of muscle(R(2)(*)(muscle)) were measured separately.The normalization of the cortex and medulla (sR(2)(*)), and the difference of sR(2)(*) between renal cortex and medulla before and post UUO (ΔsR(2)(*)) were calculated.The differences of sR(2)(*) (sCR(2)(*), sMR(2)(*), sCR(2)(*)(control), sMR(2)(*)(control)) at each time point between control and UUO group were compared by using independent sample t test.The LSD test was used to compare the sR(2)(*) in the control with that in the UUO group.The ΔsCR(2)(*) and ΔsMR(2)(*) values of the subgroups at UUO 2, 4, 6 and 8 W were compared by independent sample t test. Results: The sR(2)(*) values of UUO group were all lower than those of control group (all P<0.05), while sR(2)(*)(control) and sR(2)(*) in UUO group before operation were not significant different (P>0.05). The sCR(2)(*) values of UUO 2, 4, 6 and 8 W were 0.32±0.01, 0.37±0.01, 0.47±0.02 and 0.50±0.03.The sMR(2)(*) values were 0.39±0.02, 0.48±0.02, 0.58±0.04 and 0.65±0.05.There were significant differences of sCR(2)(*)(between) UUO 2 W and 6 W, UUO 2 W and 8 W, UUO 4 W and 6 W, UUO 4 W and 8 W (all P<0.01). There were significant differences of sMR(2)(*)(between) UUO 2 W and 6 W, UUO 2 W and 8 W, UUO 4 W and 8 W (all P<0.01). No significant difference was founded between sCR(2)(*) and sMR(2)(*) at each time point in control group (P>0.05). The ΔsCR(2)(*) values of UUO 2, 4, 6 and 8 W were 0.31±0.02, 0.20±0.02, 0.14±0.20, 0.09±0.04; the ΔsMR(2)(*) values were 0.51±0.05, 0.36±0.04, 0.28±0.05, 0.19±0.05. The ΔsCR(2)(*) values of UUO 2, 4 and 6 W were less than ΔsMR(2)(*) (P<0.05). There was no significant difference between ΔsCR(2)(*) and ΔsMR(2)(*) in UUO 8 W (P>0.05). Conclusions: The R(2)(*) change in medulla resulted from renal fibrosis is more significant than cortex.MR-BOLD can reflect the process of renal fibrosis.It's feasible and of great value to use renal MR-BOLD for the assessment of renal fibrosis induced by unilateral ureteral obstruction.

[Feasibility of susceptibility weighted imaging in the evaluation of renal fibrosis induced by unilateral ureteral obstruction in white rabbits].

Objective: To evaluate the feasibility of susceptibility weighted imaging (SWI) to reflect the progression of renal fibrosis (RF) induced by unilateral ureteral obstruction (UUO) in rabbits. Methods: Total of 32 New Zealand white rabbits (aged 4-5 months) were used to establish the UUO model (RF group) and were divided into 4 subgroups (including RF-2W group, RF-4W group , RF-6W group and RF-8W group) according to the duration of obstruction(2, 4, 6 and 8 weeks). Another 8 rabbits, underwent sham operation, were used as the control group (Sham group). T2 weighted imaging (T(2)WI) and SWI sequences were performed on the rabbits at 2, 4, 6 and 8 weeks after UUO, respectively. Rabbits were sacrificed and specimens were obtained after MR examination, then hematoxylin&eosin staining and Masson staining were performed to explore the renal tubular injury and interstitial fibrosis. The relationship between the relative signal-to-noise ratio(rSNR)measured on the SWI fusion maps and the degree of renal fibrosis was analyzed. Analysis of variance was used to compare the difference of rSNRs among 5 groups. Results: The rSNRs of the inner medulla gradually decreased over time, the rSNRs of Sham group, RF-2W group, RF-4W group, RF-6W group and RF-8W group was 2.29±0.18, 1.73±0.30, 1.67±0.08, 1.42±0.28, 1.12±0.15, respectively (F=25.876, P<0.01). In RF-2W group, the rSNRs of the outer medulla and cortex increased when compared with those in the Sham group, then they decreased gradually over time in the other groups (F=5.230, 7.621, both P<0.05). The pathological results demonstrated that the morphology of renal tubules in Sham group was normal and no apoptosis or necrosis was seen in the tubular epithelial cells. In the RF-2W group, the main pathological manifestations included renal tubules dilatation, tubular epithelial cell degeneration or necrosis and the infiltration of inflammatory cell. In Masson staining, lots of blue areas were present in the interstitial. As the obstruction time prolonged, the renal tubular collapse, inflammatory cells and fibroblasts increased significantly. Meanwhile blue area also increased significantly in Masson staining. Conclusion: SWI can be used as a noninvasive method to evaluate the pathological progression of fibrosis in the rabbit UUO model.

[Feasibility analysis of sentinel lymph node biopsy in patients with breast cancer after local lumpectomy].

OBJECTIVE: To explore the feasibility, safety and clinical application value of sentinel lymph node biopsy(SLNB)in patients with breast cancer after local lumpectomy. METHODS: Clinical data of 195 patients who previously received local lumpectomy from January 2005 to April 2015 were retrospectively analyzed. All the patients with pathologic stage T1-2N0M0 (T1-2N0M0) breast cancer underwent SLNB. Methylene blue, carbon nanoparticles suspension, technetium-99m-labeled dextran, or in combination were used in the SLNB. The interval from lumpectomy to SLNB was 1-91 days(mean, 18.3 days)and the maximum diameter of tumors before first operation was 0.2-4.5 cm (mean, 1.8 cm). RESULTS: The sentinel lymph node was successfully found in all the cases and the detection rate was 100%. 42 patients received axillary lymph node dissection (ALND), 19 patients had pathologically positive sentinel lymph node, with an accuracy rate of 97.6%, sensitivity of 95.0%, false negative rate of 5.0%, and specificity of 100%, and the false positive rate was 0. Logistic regression analysis suggested that the age of patients was significantly associated with sentinel lymph node metastasis after local lumpectomy. CONCLUSIONS: For early breast cancer and after breast tumor biopsy, the influence of local lumpectomy on detection rate and accuracy of sentinel lymph node is not significant. Sentinel lymph node biopsy with appropriately chosen tracing technique may still provide a high detection rate and accuracy.

[Correlation between susceptibility weighted imaging manifestation and serum cystatin C for delayed graft function].

OBJECTIVE: To explore the correlation between susceptibility weighted imaging (SWI) manifestation and serum cystatin C level for delayed graft function (DGF). METHODS: The conventional MRI, SWI and serum cystatin C of 27 cases with DGF in nephrotransplantation center in Third Affiliated Hospital of Suzhou University from September 2014 and August 2015 were retrospectively analyzed.By contrasting conventional MRI images of transplanted kidney in DGF, the imaging manifestations of benign tumors such as cysts and angiomyolipomas were excluded on SWI images, and then making the renal cortex as the reference, if the abnormal signal lesions were found in the transplanted kidney, the location and signal intensity would be analyzed. The differences in serum cystatin C level between DGF groups without and with abnormal signal lesions were compared by using independent-sample t-test.The correlation between SWI manifestation and serum cystatin C level for DGF was assessed with Spearman rank correlation analysis. RESULTS: A total of 15 cases were found without abnormal signal lesions and the average value of their serum cystatin C level was (2.92±0.44) mg/L.A total of 12 cases were found with abnormal low signal lesions located at junctional zone between cortex and medulla, and the average value of their serum cystatin C level was (6.91±0.96) mg/L. The differences in serum cystatin C level between the two DGF groups were statistically significant (t=-4.040, P=0.000). There was a positive correlation between the abnormal low signal lesions on SWI and serum cystatin C level (r=0.660, P=0.000). CONCLUSION: The status of renal function impairment could be reflected by being with or without abnormal signal lesions on SWI. A relatively big renal function impairment may be predicted by the appearance of abnormal low signal lesions at junctional zone between cortex and medulla on SWI.