Radiomics-based prediction of microsatellite instability in stage Ⅱ and Ⅲ rectal cancer patients based on T2WI MRI and diffusion-weighted imaging / 中华外科杂志

Objective: To examine the radiomics model based on high-resolution T2WI and diffusion weighted imaging (DWI) in predicting microsatellite stability in patients with stage Ⅱ and Ⅲ rectal cancer. Methods: From February 2016 to October 2020, 175 patients with stage Ⅱ and Ⅲ rectal cancer who met the inclusion criteria were retrospectively collected. There were 119 males and 56 females, aged (63.9±9.4) years (range: 37 to 85 years), including 152 patients with microsatellite stability and 23 patients with microsatellite instability. All patients were randomly divided into the training group (n=123) and the validation group (n=52) with a ratio of 7∶3. The region of interest was labeled on the T2WI and DWI images of each patient using the ITK-SNAP software, and PyRadiomics was used to extract seven kinds of radiomics features. After removing redundant features and normalizing features, the least absolute shrinkage and selection operation were used for feature selection. One clinical model, three radiomics models and one clinical-radiomics model were constructed in the training group based on a support vector machine. The area under receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy were used to evaluate the performance of the models in the verification group. Results: Three clinical features (age, degree of tumor differentiation, and distance from the lower edge of the tumor to the anal edge) and six radiomics features (two DWI-related features and four T2WI-related features) most related to microsatellite status of rectal cancer patients were selected. The AUC of the clinical-radiomics model in the training group was 0.95. In the validation group, the AUC was 0.81, better than the clinical model (0.68, Z=0.71, P=0.04), and equivalent to the T2WI+DWI model (0.82, Z=0.21, P=0.83). Conclusions: Radiomic features based on preoperative T2WI and DWI were related to microsatellite stability in patients with stage Ⅱ and Ⅲ rectal cancer and showed a high classification efficiency. The model based on the features provided a noninvasive and convenient tool for preoperative determination of microsatellite stability in rectal cancer patients.

Diagnostic values of serum fibrinogen and D-dimer for periprosthetic joint infection / 中华创伤骨科杂志

Objective:To evaluate the diagnostic values of serum fibrinogen and D-dimer for periprosthetic joint infection (PJI).Methods:The medical records were retrospectively analyzed of the 175 patients who had undergone hip or knee revisions at Department of Joint Surgery, Affiliated Hospital to Qingdao University from August 2013 to June 2019. Of them, 59 were diagnosed as PJI (31 knees and 28 hips), including 33 males and 26 females with an age of (67.4±11.7) years and a body mass index (BMI) of (26.1±3.6) kg/m 2 while 116 as aseptic loosening (AL) (19 knees and 97 hips), including 67 males and 49 females with an age of (70.3±8.9) years and a BMI of (25.0±3.6) kg/m 2. The plasma levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fibrinogen and D-dimer in the 2 groups were recorded and analyzed. The receiver operating characteristic curve (ROC) was used to calculate the sensitivity and specificity of each indicator; the diagnostic value for each indicator was calculated according to the area under the curve (AUC). Results:There was no significant difference between the PJI and AL groups in gender, age or BMI ( P>0.05), but there was a significant difference in the joint type ( P<0.05). Compared with the AL group, the PJI group had significantly higher levels of CRP, ESR, fibrinogen and D-dimer ( P<0.05). The AUCs for CRP, ESR, fibrinogen and D-dimer were 0.830, 0.850, 0.848 and 0.664, respectively. By the Youden index, the optimal predictive cutoffs for CRP, ESR, fibrinogen and D-dimer were 8.06 mg/L, 17.60 mm/h, 3.73 g/L and 685.00 ng/mL, giving sensitivities of 79.2%, 85.4%, 81.3% and 64.6% and specificities of 85.7%, 76.2%, 79.8% and 61.9%. Conclusions:The diagnostic value of serum fibrinogen may be high for PJI, similar to that of CRP or ESR. However, D-dimer may be of limited value for diagnosis of PJI.

The expression of Notch pathway in nasal polyps and its correlation with the decreased Treg percentage and eosinophil infiltration / 中华耳鼻咽喉头颈外科杂志

Objective: To investigate the correlation between Notch pathway expression in nasal polyps and Treg percentage and Eos infiltration. Methods: Patients with chronic sinusitis and simple nasal septum deviation who received nasal endoscopic surgery in the Third Affiliated Hospital of Sun Yat-Sen University between November 2012 and August 2018 were selected and enrolled in CRS group and control group respectively. Nasal mucosa tissues were collected from 30 CRSsNP patients (14 males and 16 females aged from 18 to 63), 58 CRSwNP patients (38 males and 20 females aged from 18 to 65) and 29 patients (19 males and 10 females aged from 20 to 57), who underwent nasal endoscopic surgery for correction of simple nasal septum deviation. Hematoxylin-eosin(HE) staining was used to observe the infiltration of eosinophilic granulocytes in the tissues and to classify chronic sinusitis with polyps (CRSwNP) into eosinophilic chronic rhinosinusitis with nasal polyps (Eos-CRSwNP)and non-eosinophilic chronic rhinosinusitis with nasal polyps (Eos-CRSwNP). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of Notch pathway receptors (Notch-l, 2, 3, 4) and their ligands (Jagded-l, Jagded-2, Delta-l, Delta-3and Delta-4) in the nasal mucosa of each group, as well as the expression of Th2 cytokines (IL-4, IL-5, IL-13), eosinophilic cationic protein (ECP)and the key transcription factor Foxp3 in Treg cells. Finally, flow cytometry was used to detect CD4+CD25+Foxp3+ Treg cells in nasal mucosa of each group. Results: Compared with controls, the expression of Th2 cytokines (IL-4, IL-5, IL-13) in CRSsNP and non-Eos-CRSwNP patients was the highest in Eos-CRSwNP (F=16.930,9.197,9.116, all P<0.05). Foxp3 had the lowest expression in Eos-CRSwNP patients and was lower than non-Eos-CRSwNP patients (F=2.780,P<0.05), and was negatively correlated with ECP (r=-0.326,P<0.05). Compared with controls, Eos-CRSwNP patients in CRSsNP patients and non-Eos-CRSwNP patients exhibited a significantly lower frequency of CD4+CD25+Foxp3+Treg cells (F=13.140, all P<0.01). The expression of Notch-l and Jagged-l in Eos-CRSwNP was significantly higher than that of the controls, CRSsNP patients and non-Eos-CRSwNP patients (F=5.953/F=6.380, P<0.05). In the nasal polyp group, the expression of Notch-l and Jagged-l showed significantly negative correlation with Foxp3 (r=-0.611/-0.346, all P<0.05), and positive correlation with Th2 cytokines (IL-4, IL-5, IL-13) and ECP, respectively (r=0.781/0.459,0.621/0.601,0.605/0.490,0.464/0.668, all P<0.05). There was no significant difference in the expression of receptor and ligand of the other Notch pathway among the groups. Conclusion: Abnormal activation of Notch-l/Jagged-l pathway may be involved in decreasing Treg ratio in Eos-CRSwNP, thereby promoting Th2 inflammatory response and Eosinophil infiltration.

Curative effect of 3D printing trabecular metal acetabular cups in revision of total hip arthroplasty / 中华创伤杂志

Objective:To evaluate the curative effect of 3D printing titanium trabecular metal （TTM） acetabular cups in revision of total hip arthroplasty （THA）.Methods:A retrospective case series study was conducted on the clinical data of 24 patients （25 hips） undergoing THA revision in Affiliated Hospital of Qingdao University from May 2016 to September 2019. There were 10 males and 14 females，aged 43-78 years ［（63.0 ± 11.4） years］. According to Paprosky classification，5 patients（5 hips） were classified as type Ⅰ，9 patients （10 hips） as type ⅡA，5 patients （5 hips） as type ⅡB，1 patient （1 hip） as type ⅡC and 4 patients （4 hips） as type ⅢC. All patients used 3D printing TTM cups. Seven patients （7 hips） were combined with 3D printing TTM pads，and 3 patients （3 hips） were combined with structural bone grafts. The visual analogue scale （VAS），Harris score and quality of life Health Survey Scale （SF-36） score were evaluated before operation，3 months after operation，12 months after operation and at the last follow-up. The X-ray film of hip joint was performed to evaluate the upward movement distance of hip center of rotation （HCOR），limb-length discrepancy （LLD） before operation，1 day after operation and at the last follow-up. The position of cups and bone ingrowth were evaluated at the last follow-up. The postoperative complications were observed.Results:All patients were followed up for 14-54 months ［（34.2 ± 9.3）months］. The VAS was （4.0 ± 0.7）points，（2.3 ± 0.8）points and （0.9 ± 0.2）points at postoperative 3 months，12 months and the last follow-up，significantly lower than that preoperatively ［（6.1 ± 1.0）points］ （ P < 0.05）. A statistically significant difference was found in the pairwise comparisons of postoperative VAS at postoperative 3 months，12 months and the last follow-up（ P < 0.05）. The Harris score was （64.6 ± 5.3）points，（80.5 ± 3.7）points，and （90.3 ± 3.6）points at postoperative 3 months，12 months and the last follow-up，significantly higher than that preoperatively ［（38.8 ± 6.2）points］ （ P < 0.05）. A statistically significant difference was found in the pairwise comparisons of postoperative Harris score at postoperative 3 months，12 months and the last follow-up（ P < 0.05）. The SF-36 score was （556.3 ± 21.9）points，（711.6 ± 15.9）points and （752.8 ± 23.0）points at postoperative 3 months，12 months and the last follow-up，significantly higher than that preoperatively ［（326.3 ± 30.7）points］ （ P < 0.05）. A statistically significant difference was found in the pairwise comparisons of postoperative SF-36 score at postoperative 3 months，12 months and the last follow-up（ P < 0.05）. The upward movement distance of HCOR was （13.5 ± 2.6）mm and （13.6 ± 2.6）mm on the first day after operation and at the last follow-up，significantly lower than that preoperatively ［（34.1 ± 3.5）mm］ （ P < 0.05）. The LLD was （6.2 ± 1.8）mm and （5.3 ± 1.5）mm on the first day after operation and at the last follow-up，significantly lower than that preoperatively ［（31.6 ± 5.2）mm］ （ P < 0.05）. All the cups were stable. Good bone ingrowth was found in 23 hips. There was no postoperative complication except for one patient with poor wound healing. Conclusion:For THA revision，the use of 3D printing TTM cups can effectively relieve pain，improve hip function，provide satisfactory biological fixation and and reduce complications.

A Comparative Study of 2 Different Segmentation Methods of ADC Histogram for Differentiation Genetic Subtypes in Lower-Grade Diffuse Gliomas.

BACKGROUND: To evaluate the diagnostic performance of apparent diffusion coefficient (ADC) histogram parameters for differentiating the genetic subtypes in lower-grade diffuse gliomas and explore which segmentation method (ROI-1, the entire tumor ROI; ROI2, the tumor ROI excluding cystic and necrotic portions) performs better. MATERIALS AND METHODS: We retrospectively evaluated 56 lower-grade diffuse gliomas and divided them into three categories: IDH-wild group (IDHwt, 16cases); IDH mutant with the intact 1p or 19q group (IDHmut/1p19q+, 18cases); and IDH mutant with the 1p/19q codeleted group (IDHmut/1p19q-, 22cases). Histogram parameters of ADC maps calculated with the two different ROI methods: ADCmean, min, max, mode, P5, P10, P25, P75, P90, P95, kurtosis, skewness, entropy, StDev, and inhomogenity were compared between these categories using the independent t test or Mann-Whitney U test. For statistically significant results, a receiver operating characteristic (ROC) curves were constructed, and the optimal cutoff value was determined by maximizing Youden's index. Area under the curve (AUC) results were compared using the method of Delong et al. RESULTS: The inhomogenity from the two different ROI methods for distinguishing IDHwt gliomas from IDHmut gliomas both showed the biggest AUC (0.788, 0.930), the optimal cutoff value was 0.229 (sensitivity, 81.3%; specificity, 75.0%) for the ROI-1 and 0.186 (sensitivity, 93.8%; specificity, 82.5%) for the ROI-2, and the AUC of the inhomogenity from the ROI-2 was significantly larger than that from another segmentation, but no significant differences were identified between the AUCs of other same parameters from the two different ROI methods. For the differentiaiton of IDHmut/1p19q- tumors and IDHmut/1p19q+ tumors, with the ROI-1, the ADCmode showed the biggest AUC (AUC: 0.784; sensitivity, 61.1%; specificity, 90.9%), with the ROI-2, and the skewness performed best (AUC, 0.821; sensitivity, 81.8%; specificity, 77.8%), but no significant differences were identified between the AUCs of the same parameters from the two different ROI methods. CONCLUSION: ADC values analyzed by the histogram method could help to classify the genetic subtypes in lower-grade diffuse gliomas, no matter which ROI method was used. Extracting cystic and necrotic portions from the entire tumor lesions is preferable for evaluating the difference of the intratumoral heterogeneity and classifying IDH-wild tumors, but not significantly beneficial to predicting the 1p19q genotype in the lower-grade gliomas.

A Nomogram Predicting Microvascular Invasion Risk in BCLC 0/A Hepatocellular Carcinoma after Curative Resection.

BACKGROUND: Numerous studies have shown that hepatocellular carcinoma (HCC) without microvascular invasion (MVI) may have better outcomes. This study established a preoperative MVI risk nomogram mainly incorporating three related risk factors of MVI in BCLC 0/A HCC after surgery. METHODS: Independent predictors for the risk of MVI were investigated, and an MVI risk nomogram was established based on 60 patients in the training group who underwent curative hepatectomy for BCLC 0/A HCC and validated using a dataset in the validation group. RESULTS: Univariate analysis in the training group showed that hepatitis viral B (HBV) DNA (P=0.034), tumor size (P<0.001), CT value in the venous phase (P=0.039), CT value in the delayed phase (P=0.017), peritumoral enhancement (P=0.013), visible small blood vessels in the arterial phase (P=0.002), and distance from the tumor to the inferior vena cava (IVC) (DTI, P=0.004) were risk factors significantly associated with the presence of MVI. According to multivariate analysis, the independent predictive factors of MVI, including tumor size (P=0.002), CT value in the delayed phase (P=0.018), and peritumoral enhancement (P=0.057), were incorporated in the corresponding nomogram. The nomogram displayed an unadjusted C-index of 0.851 and a bootstrap-corrected C-index of 0.832. Calibration curves also showed good agreement on the presence of MVI. ROC curve analyses showed that the nomogram had a large AUC (0.851). CONCLUSIONS: The proposed nomogram consisting of tumor size, CT value in the delayed phase, and peritumoral enhancement was associated with MVI risk in BCLC 0/A HCC following curative hepatectomy.

Investigation of extent of liver resection for liver cancer combined with liver cirrhosis / 中华消化外科杂志

Liver resection is widely accepted as firstline treatment for patient with liver cancer.Most patients with liver cancer have varied degrees of liver cirrhosis,which is an important risk factor adversely affect the outcomes of liver resection.The adverse effects are more significant as the increase of degree of liver cirrhosis.At present,it is generally believed that liver resection of 60％ volume is appropriate for patients with liver cirrhosis when liver function is within Child A.However,surgeons usually assess whether a patient has liver cirrhosis using "Yes" or "No",ignoring the pathological severity of liver cirrhosis.How to determine the extent of liver resection for patients combined with liver cirrhosis is still controversial.The authors have proposed a method for evaluating the degree of cirrhosis before and during surgery.It is believed that the extent of liver resection should be appropriately reduced with the increase of degree of liver cirrhosis.Further studies are needed to investigate how to accurately assess the severity of liver cirrhosis and how to scientifically determine the extent of liver resection before operation.

Therapy of hilar cholangiocarcinoma in the precise medicine period / 中华消化外科杂志

Because of the special anatomical position of hilar cholangiocarcinoma and its characteristics of longitudinal and vertical invasion,it is difficult to obtain satisfactory effect by surgical resection.More and more researchers have realized that the treatment of the hilar cholangiocarcinoma should take biological characteristics of the tumor.Precise medicine using of frontier technologies and omics technologies such as proteomics and genomics,can accurately diagnose diseases at molecular level and may provide a new model for the treatment of hilar cholangiocarcinoma.The gene mutation rate of the hilar cholangiocarcinoma is higher,and the most common mutation genes are KRAS and TP53,following other genes such as CDKN2A,SMAD4,ERBB2,PTEN,APIK3CA,ARID1A,MLL3,ROBO2,RNF43,and PEG3,GNAS,etc.Such frequent,important functional mutations suggest that hilar cholangiocarcinoma may have potential therapeutic targets for molecular targeted drugs.However,due to the complex pathogenesis of the bile duct cancer,the clinical trials of most targeted drugs have not been able to achieve breakthrough progress.Surgical resection should still remain the dominant treatment.The appropriate extent of hepatectomy should be determined individually,and the minor resection is enough for most hilar cholangiocarcinoma.

Early amplitude-integrated EEG monitoring 6 h after birth predicts long-term neurodevelopment of asphyxiated late preterm infants.

UNLABELLED: The present study aimed to assess the prognostic value of early amplitude-integrated electroencephalogram (aEEG) in late preterm infants who were born at a gestational age between 34 0/7 and 36 6/7 weeks for the prediction of neurobehavioral development. Late preterm infants (n = 170) with normal, mild, and severe asphyxia underwent continuous recording of aEEG for 4-6 h starting 6-8 h after delivery. The recordings were analyzed for background pattern, sleep-wake cycle (SWC), and seizures. Survivors were assessed at 18 months by neurological examination and Bayley Scales of Infant Development II. The incidence of adverse neurological outcome in the asphyxia group was significantly higher than in the normal group. For late preterm infants in the asphyxia group, abnormal aEEG pattern had a predictive potential of neurological outcomes with sensitivity of 78.57% (specificity, 87.80%; positive predictive value [PPV], 68.75%; negative predictive value [NPV], 92.31%; power, 85.45%). Non-SWC and intermediate SWC significantly were increased (25.45 and 52.73%, respectively) in the asphyxia group vs. the normal group. SWC pattern had neurological prognosis value in the asphyxia group with sensitivity of 64.29% (specificity, 87.80%; PPV, 64.29%; NPV, 87.80%; power, 81.82%). CONCLUSION: Early aEEG patterns are important determinants of long-term prognosis of neurodevelopmental outcome in asphyxiated late preterm infants.

Biomechanical study of improved memory alloy embracing fixators in treatment of periprosthetic femoral fracture due to hip arthroplasty / 中华创伤杂志

Objective To study the mechanics of improved memory alloy fixators for salvage of periprosthetic femoral fracture (PFF) after hip arthroplasty in the elderly.Methods Thirty countrymen fresh cadaveric femurs with no pathological defect,fracture,deformity or tumor were randomly divided into experimental group and control group with 15 femurs in each according to the random number table.A model of Vancouver type B1 periprosthetic femoral fracture following hip arthroplasty was induced.The fracture was treated with modified memory alloy embracing fixators in experimental group;instead general memory alloy embracing fixators in control group.All specimens were tested biomechanically.Results Under the same mechanical loading,the two groups showed respective 30％ and 48％ maximum differences in stress value and displacement.Results in three-point bending test did not differ significantly between the two groups (P ＞ 0.05),but there were significant differences in axial compression and torsion test (P ＜ 0.05 or 0.01).Conclusion The improved memory alloy embracing fixators present better resistance to compression and torsion compared to the general fixators.

[Effect of zinc deficiency on intestinal mucosal morphology and digestive enzyme activity in growing rat].

OBJECTIVE: In this study, a growing rat model of zinc deficiency was established to investigate the effect of zinc deficiency on intestinal mucosal morphology and digestive enzyme activity as well as to provide a scientific basis for zinc supplementation therapy in patients with diarrhea. METHOD: Three-week-old weaned Sprague-Dawley male rats (n = 30) were randomly divided into 3 groups with 10 in each: rats in the control group (ZA) were fed with a normal diet containing 30 µg/g zinc; rats in the zinc deficient group (ZD) were fed with a zinc-deficient diet containing 0.4 µg/g zinc (refer to AIN-76 formula); and rats in the paired fed group (PF) were fed with a normal diet, but the food intake was limited to intake of rats in ZD group in the previous day. All rats were provided with deionized water for drinking. Their body weight was measured and the food intake during the previous day was recorded early in the morning of the following day. Symptoms of zinc deficiency, such as anorexia, diarrhea, dermatitis, and growth retardation, were observed. Two weeks later, the rats were sacrificed and serum zinc concentration was measured. Jejunal mucosa was taken for biopsy and was stained with hematoxylin and eosin (HE). The height ratio of the jejunal mucosal villi and crypts was measured. In addition, the activity of lactase in the jejunal mucosal brush border, γ-glutamyl peptidase (GGT), and aminopeptidase N (APN) were measured. RESULT: The average weight of the rats in the ZA, ZD, and PF groups at the beginning of the experiment was (67.4 ± 5.3) g, (64.7 ± 4.8) g, and (66.5 ± 4.1) g, respectively, and the average daily food intake was (11.2 ± 1.0) g, (11.6 ± 1.6) g, and (11.2 ± 1.4) g, respectively. The intergroup differences were not significant. On the 7(th) day of experiment, no significant differences in average food intake were observed between the ZD group and the ZA and PF groups, but the average body weight in the ZD group was significantly lower than that in the ZA and PF groups (P < 0.01). At the end of the experiment (2 weeks), the average weight in the ZD group (112.0 ± 11.5) g was significantly lower than that in the ZA (164.0 ± 15.9) g and PF groups (137.5 ± 16.2) g. The average food intake in the ZD group (13.4 ± 5.1) g was significantly lower than that in the ZA group (18.2 ± 2.4) g (P < 0.01). Serum zinc level in the ZD group (733 ± 231) µg/L was significantly lower than that in the ZA (1553 ± 159) µg/L and PF groups (1457 ± 216) µg/L (P < 0.01). The height ratio of jejunal mucosa villus and crypt in the ZA, ZD, and PF groups was 2.98 ± 0.5, 2.77 ± 0.5, and 2.81 ± 0.7, respectively, and lactase activity was (26.1 ± 15.0) U/mg, (27.4 ± 12.8) U/mg, and (40.8 ± 18.5) U/mg, respectively, without significant intergroup differences. The GGT activity in the jejunal mucosa in the ZD group (12.7 ± 6.5) U/g was significantly lower than that in the ZA (19.1 ± 10.4) U/g and PF groups (18.5 ± 7.7) U/g, but the difference was not significant. The activity of APN in the jejunal mucosa in the ZD group (25.5 ± 7.5) U/g was significantly lower than that in the ZA (48.7 ± 16.8) U/g and PF groups (43.9 ± 14.5) U/g (P < 0.01). CONCLUSION: Zinc deficiency can cause loss of appetite, weight loss, and decreased activity of peptidase in the jejunal mucosal brush border. Zinc deficiency has little effect on the height ratio of the villus and crypt and lactase activity, thereby indicating that zinc deficiency may first affect protein digestion and absorption.

A study of oval cell proliferation kinetics in the rat 2-acetylaminofluorene/partial hepatectomy model / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the changes of oval cell proliferation rate in the rat 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH) model.</p><p><b>METHODS</b>Livers were collected from 2-AAF/PH rats at different time points after hepatectomy. Paraffin sections were investigated by double immunofluorescent staining with confocal microscopy for oval cell marker epithelial cell adhesion molecule and proliferative index proliferating cell nuclear antigen, or epithelial cell adhesion molecule and alpha-smooth muscle actin. Deposition of matrix in liver tissue was detected by sirius red staining.</p><p><b>RESULTS</b>Response of ductular oval cells could be observed in portal area at 2 days after PH, and the number of oval cells reached its peak at 9 days and then gradually declined. Oval cell proliferation rate decreased from (91.3 +/- 1.6)% at 2 days after PH to (53.6 +/- 4.4)% at 12 days (P < 0.01). In addition, oval cells infiltrating into liver parenchyma were closely associated with activated hepatic stellate cells and extracellular matrix.</p><p><b>CONCLUSIONS</b>Oval cell proliferation rate starts decreasing before its number reaches a peak in 2-AAF/PH model. Hepatic stellate cells probably tightly regulate oval cell number through secreting several factors and producing extracellular matrix.</p>

Expression and its significance of telomerase in rat hepatic oval cells / 中华消化外科杂志

Objcctive To detect the telomerase activity in rat hepatic oval cells, and to explore the relationship between telomerase expression and the proliferation and differentiation of oval cells. Methods The 2-acetamidofluorene/partial bepatectomy (2-AAF/PH) rat model was used to induce the proliferation of oval cells. Oval cells were isolated by modified collagenase perfusion and gradient centrifugation. Electron microscope exami-nation and immunofluorescence were adopted to identify oval cells. Immunohistochemistry, RT-PCR and fluores-cence quantitative PCR were used to detect the expression of telomerase in oval cells. All the data collected were analyzed by t test. Results The proliferatiun of oval cells was successfully induced by 2-AAF/PH rat model. Freshly isolated oval cells showed a large and ovoid nuclei, a small proportion of cytomplasm and a cobblestone appearance. When viewed by electron microscopy, there were few and immature organelles, and the nucleus/ cytoplasm ratio was high. Immunofluorescence staining showed that oval cells expressed OV-6, alpha-fetoprotein, cytokeratin-19, albumin and c-kit. Telomerase reverse transcriptase (TERT) was located in the nuclei of oval cells which were around the portal areas. As oval cells differentiated into small hepatocytes, the number of TERT-positive cells decreased significantly. The expression level of TERT mRNA in normal rat liver tissue was 2.27 times higher than that in LE-6 oval cells; the expression level of TERT mRNA in the isolated oval cells was 1.26 times higher than that in LE-6 oval cells. The telomerase activity decreased gradually (from △A=1.05, 1.15 to △A=0.25, 0.45) as the increase of oval cells passage (from passage 24 to passage 40) (t=17.74, 12.38, P<0.05). Conclusions Oval cells have telomerase activity. Telomerase may be indispensable for maintaining the proliferative and multi-directional differentiation abilities of oval cells.

Hepatic progenitor cell activation and expansion in human liver cirrhosis / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To confirm whether human hepatic progenitor cells (HPCs) occur in human liver cirrhosis, to investigate the relationship between the degree of HPCs activation and the degree of liver inflammation and to provide evidence that HPCs can differentiate into hepatocytes.</p><p><b>METHODS</b>Surgical specimens from 30 human cirrhotic livers and from 3 normal livers were investigated by light microscopy and immunohistochemical staining for CK7 (a marker of biliary differentiation) and SMA (a marker of hepatic stellate cell activation). The degree of portal inflammation was determined on routine stained sections. The number of HPCs and intermediate hepatocytes and the extent of the ductular reaction were assessed.</p><p><b>RESULTS</b>HPCs and ductular reaction were not observed in the normal livers. In liver cirrhosis cases the HPCs originated from the portal areas. With the increase of portal inflammation, HPCs and ductular reaction extending from the periphery of the liver cirrhosis nodules to the liver parenchyma and the intermediate hepatocyte proliferation were observed. The notable hepatic stellate cell activation occurred around the HPCs and ductular reaction. The number of HPCs and the extent of ductular reaction increased significantly as the portal inflammation increased. There were significant correlations between the number of HPCs with the number of intermediate hepatocytes. In addition, there was a strong correlation between the ALT and AST with the number of HPCs and intermediate hepatocytes.</p><p><b>CONCLUSION</b>Human hepatic progenitor cell activation exists in human liver cirrhosis. The inflammation is a trigger for HPCs activation. HPCs migration from the portal area to liver parenchyma and their differentiation into hepatocytes are important pathways for liver regeneration.</p>