Idebenone relieves the damage of heat stress on the maturation and developmental competence of porcine oocytes.

The reproductive function of animals is often affected by climatic conditions. High-temperature conditions can cause damage to oocyte maturation and embryonic development in a variety of ways. The purpose of this study was to prove that supplementation idebenone (IDB) to the maturation medium can improve the maturation and development of porcine oocytes after heat stress (HS). Porcine cumulus-oocyte complexes (COCs) were cultured in the maturation medium with different concentrations of IDB (0, 0.1, 1 and 10 µM) for 44 hr at either 38.5°C or under the HS conditions. The cumulus oophorus expansion, nuclear maturation and blastocyst rate after parthenogenetic activation (PA) were measured. We found that HS (in vitro maturation 20-24 hr, 42°C) exposure significantly reduced cumulus expansion index and maturation rate of oocytes and the blastocyst rate of PA embryos, while IDB supplementation significantly improved oocyte maturation and development to the blastocysts stage after PA. Moreover, the addition of IDB decreased the intracellular level of ROS and increased GSH content, hence enhancing the antioxidant capacity of oocytes under HS. Meanwhile, IDB treatment also obviously improved the mitochondrial membrane potential and ATP synthesis of oocytes under HS conditions. Furthermore, IDB treatment increased the expression of GDF9 and BMP15 in IVM oocytes which attribute to improve the quality and outcome of IVM oocytes and the development competence of PA embryos in pigs. In summary, we demonstrated that IDB supplementation into the maturation medium exerted protective effects and improved the ability of maturation and developmental competence of porcine oocytes exposed to HS.

Risk factors for bile duct injury after laparoscopic cholecystectomy: A protocol for systematic review and meta-analysis.

BACKGROUND: Bile duct injury (BDI) is one of the serious complications in laparoscopic cholecystectomy (LC), but there is currently a lack of systematic review of risk factors related to BDI after LC. This study conducts meta-analysis on the risk factors related to bile duct injury after LC, the purpose is to provide reference basis for preventing and reducing BDI after LC. METHODS: Using the Computer to retrieve of Chinese and English databases such as CNKI, WANFANG Data, the VIP Network, PubMed, Embase, the Cochrane Library, etc. The time is from the establishment of each database until August 2021. A case-control study is selected that is related to the risk factors of BDI after LC. This meta-analysis using RevMan 5.4 and State 12.0 software is performed after two researchers independently sift through the literature, extract the data, and evaluate the bias risk included in the study. RESULTS: The risk factors related to BDI after LC will be analyzed by systematic review. CONCLUSION: The conclusion of this study will play an important role in reducing BDI after LC. OSF REGISTRATION: DOI 10.17605/OSF.IO/2B3K9, the registration URL is https://osf.io/2b3k9.

The Prevalence of Erosive Tooth Wear and Related Risk Factors in 6- to 12-Year-Old Students.

PURPOSE: To evaluate the epidemiological characteristics of erosive tooth wear in primary school students aged 6-12 in Jinzhou, including: prevalence, severity, extent, intraoral distribution and associated risk factors. MATERIALS AND METHODS: The data collection consists of two parts: the first part is the clinical examination of the participants. All erupted teeth were clinically assessed by three calibrated examiners, and classified according to the basic erosive wear examination (BEWE); The second part is a questionnaire about demographic information, parafunctional movement and lifestyle, completed by the parents or their guardians. RESULTS: A total of 1,469 children were included in this experiment; erosive tooth wear (ETW) prevalence (BEWE ≥ 1) was 54.9%. According to cumulative BEWE index, the proportion of different ETW severity (high, medium, low, none) was 6.8%, 16.3%, 27.0% and 49.9%, respectively. In an analysis of risk factors, family factor, age, gender, extracurricular study time, oral hygiene habit, bruxism, unilateral mastication and acid diet was associated with the prevalence of ETW. CONCLUSIONS: This study shows that ETW has a high prevalence in students aged 6-12, and more common in deciduous molars and deciduous canine. Abrasion, attrition and erosion play an important role in ETW.

Effects of astaxanthin on plasma membrane function and fertility of boar sperm during cryopreservation.

Mammalian sperm is highly susceptible to reactive oxygen species (ROS) during the cryopreservation process. Astaxanthin (AST), a red pigment of the carotenoid family, is recognized as having a variety of beneficial biological activities and effects, including antioxidant, anticancer, anti-diabetic, and anti-inflammatory. The present study aimed to investigate whether the presence of AST protected boar sperm from ROS stress during cryopreservation. Boar sperm was diluted with a freezing medium supplemented with different concentrations of AST (0, 0.5, 1, 2, or 5 µM). The addition of AST, especially at a concentration of 2 µM, exerted positive effects on post-thaw sperm motility parameters. Meanwhile, sperm plasma membrane integrity and acrosome integrity of post-thaw sperm were significantly increased, while lipid peroxidation was inhibited in response to 2 µM AST treatment. Interestingly, compared to the control, supplementation with 2 µM AST increased unsaturated fatty acids (UFAs) levels and decreased saturated fatty acids (SFAs) content in post-thaw sperm, leading to a decreased ratio of SFAs/UFAs in the AST group. In conclusion, the addition of AST to freezing extenders inhibited lipid peroxidation and regulated fatty acid composition of the sperm membrane, improved post-thaw sperm quality, and had no adverse effect on boar sperm in vitro fertilization (IVF) capacity and potential for embryonic development. Our data provide a novel insight into understanding the mechanisms of AST concerning protecting boar sperm quality against ROS damage during cryopreservation.

The prevalence of vision impairment and refractive error in 3654 first year students at Tianjin Medical University.

AIM: To determine the prevalence of vision impairment (VI) and refractive error in first year university students at the Tianjin Medical University. METHODS: This is a cross-sectional observational cohort study of VI and refractive error among first year university students at the Tianjin Medical University. The first year university students were involved in this study and were given a detailed questionnaire including age, birth date, and spectacle wearing history. A standardized ophthalmologic examination including visual acuity (VA), slit-lamp examination, non-cycloplegic auto-refraction, objective refraction, fundus photography, and examination of their spectacles were recorded. RESULTS: A total of 3654 participants were included in this study. Totally 3436 (94.03%) individuals had VI in this population. Totally 150 (4.10%) individuals had VI due to ocular disease, including amblyopia, congenital cataract, retinal atrophy or degeneration, strabismus, congenital nystagmus, refractive surgery orthokeratology. Totally 3286 (89.93%) subjects had VI due to refractive error. Only 218 (5.97%) students were emmetropia. Moreover, refractive error was the main cause for the VI (95.63%). Totally 3242 (92.52%) students were myopia and the prevalence of mild, moderate, and high myopia subgroup was 27.05%, 44.35%, and 21.26% respectively. Totally 44 (1.29%) subjects were hyperopic. The rates of uncorrected visual acuity (UCVA), presenting visual acuity (PVA) and best corrected visual acuity (BCVA) which better than 20/20 in both eyes were 5.65%, 22.32% and 82.13% respectively. The rates of correction, under correction and well correction in myopia subjects were 82.73%, 84.39% and 15.61%, respectively. CONCLUSION: We present a high prevalence of refractive errors and high rates of under correction refractive error among first year university students. These results may help to promote vision protection work in young adults.

Interobserver Agreement in the Diagnosis of Inflammatory Bowel Disease-Associated Neoplasia in China in Comparison to Subspecialized American Gastrointestinal Pathologists.

BACKGROUND: The aim of this study was to evaluate the interobserver variability in diagnosing inflammatory bowel disease (IBD)-associated neoplasia among practicing pathologists from China using telepathology, a practice of remote diagnostic consultation increasingly used nationally and internationally, and its comparison with the interpretation of subspecialized gastrointestinal (GI) pathologists from the United States (US). METHODS: Eight GI pathologists from the US and 4 pathologists from China with an interest in GI pathology participated in this study. A total of 50 colonic biopsies from patients with a clinical history of IBD from 8 medical centers in China were included. All microscopic slides in each case were digitized using an Aperio system. One pathologist (XL) reviewed the digitized full-slide images, and selected areas of interest were captured at low, medium, and high magnifications at a resolution of 1712 × 1072 pixels and saved as tagged image file format (TIFF) files on read-only DVD. Each pathologist evaluated the images and selected the most appropriate diagnostic category for each case (negative, indefinite, low-grade dysplasia [LGD], high-grade dysplasia [HGD], and carcinoma). A Fleiss' kappa coefficient (K) analysis was performed to determine interobserver agreement and the agreement of each pathologist from China with the consensus diagnosis (defined as diagnostic agreement by at least 4 participating US GI pathologists). RESULTS: There was substantial interobserver agreement among 4 pathologists from China on the interpretation of IBD-associated neoplasia (kappa value 0.68, 95% confidence interval: 0.56-0.78). A consensus diagnosis included negative (n = 22), LGD (n = 22), HGD (n = 3), carcinoma (n = 2), and indefinite for dysplasia (n = 1). Using consensus diagnoses as references, the agreement between each pathologist from China and the consensus diagnosis was substantial with kappa values ranging from 0.75 to 0.80. CONCLUSIONS: This study reveals substantial interobserver agreement for the interpretation of colonic neoplasia in IBD using digitized images among Chinese pathologists as well as between each Chinese pathologist and a consensus diagnosis generated by US GI pathologists.

Ischemic or toxic injury: A challenging diagnosis and treatment of drug-induced stenosis of the sigmoid colon.

A 48-year-old woman was admitted with 15-mo history of abdominal pain, diarrhea and hematochezia, and 5-mo history of defecation difficulty. She had been successively admitted to nine hospitals, with an initial diagnosis of inflammatory bowel disease with stenotic sigmoid colon. Findings from computed tomography virtual colonoscopy, radiography with meglumine diatrizoate, endoscopic balloon dilatation, metallic stent implantation and later overall colonoscopy, coupled with the newfound knowledge of compound Qingdai pill-taking, led to a subsequent diagnosis of ischemic or toxic bowel disease with sigmoid colon stenosis. The patient was successfully treated by laparoscopic sigmoid colectomy, and postoperative pathological examination revealed ischemic or toxic injury of the sigmoid colon, providing a final diagnosis of drug-induced sigmoid colon stenosis. This case highlights that adequate awareness of drug-induced colon stenosis has a decisive role in avoiding misdiagnosis and mistreatment. The diagnostic and therapeutic experiences learnt from this case suggest that endoscopic balloon expansion and colonic metallic stent implantation as bridge treatments were demonstrated as crucial for the differential diagnosis of benign colonic stenosis. Skillful surgical technique and appropriate perioperative management helped to ensure the safety of our patient in subsequent surgery after long-term use of glucocorticoids.

Effect of Cultivar, Temperature, and Environmental Conditions on the Dynamic Change of Melatonin in Mulberry Fruit Development and Wine Fermentation.

High levels of melatonin have been reported in various foods but not in mulberry or its wine. This study investigated the dynamic changes of melatonin levels during mulberry fruit development and ethanol fermentation of 2 different colored mulberry cultivars ("Hongguo2Ë® Morus nigra, black and "BaiyuwangË® Morus alba, white) at 2 fermentation temperatures (16 and 25 °C). Our results showed that the melatonin level increased in the beginning of mulberry development but decreased in the end. The MnTDC gene expression level correlated with melatonin production, which implied that TDC may be the rate-limiting enzyme of the melatonin biosynthetic process in mulberries. During mulberry fermentation, the melatonin concentration increased rapidly in the beginning and then decreased gradually. Low temperature delayed the melatonin production during fermentation. A relatively high level of melatonin was found in "Hongguo2Ë® compared with "BaiyuwangË® during fruit development and fermentation. The variation of melatonin correlated with the ethanol production rate, suggesting that melatonin may participate in physiological regulation of Saccharomyces cerevisiae during the fermentation stage.

Expression profile and potential roles of EVA1A in normal and neoplastic pancreatic tissues.

BACKGROUND: EVA1A (eva-1 homolog A) is a novel gene that regulates programmed cell death through autophagy and apoptosis. Our objective was to investigate the expression profiles and potential role of EVA1A in normal and neoplastic human pancreatic tissues. MATERIALS AND METHODS: The expression pattern of EVA1A in normal pancreatic tissue was examined by indirect immunofluorescence and confocal microscopy. Protein levels in paraffin-embedded specimens from normal and diseased pancreatic and matched non-tumor tissues were evaluated by immunohistochemistry. RESULTS: EVA1A colocalized with glucagon but not with insulin, demonstrating production in islet alpha cells. Itwas strongly expressed in chronic pancreatitis, moderately or weakly expressed in the plasma membrane and cytoplasm in pancreatic acinar cell carcinoma, and absent in normal pancreatic acinar cells. Although the tissue architecture was deformed, EVA1A was absent in the alpha cells of pancreatic ductal adenocarcinomas, intraductal papillary mucinous neoplasms, mucinous cystadenomas, solid papillary tumors and pancreatic neuroendocrine tumors. CONCLUSIONS: EVA1A protein is specifically expressed in islet alpha cells, suggesting it may play an important role in regulating alpha-cell function. The ectopic expression of EVA1A in pancreatic neoplasms may contribute to their pathogenesis and warrants further investigation.

KRAS and BRAF gene mutations and DNA mismatch repair status in Chinese colorectal carcinoma patients.

AIM: To investigate gene mutations and DNA mismatch repair (MMR) protein abnormality in Chinese colorectal carcinoma (CRC) patients and their correlations with clinicopathologic features. METHODS: Clinical and pathological information for 535 patients including 538 tumors was reviewed and recorded. Mutation analyses for exon 2 of KRAS gene and exon 15 of BRAF gene were performed by Sanger sequencing except that in 9 tumors amplification refractory mutation system PCR was used. Expression of MMR proteins including MHL1, MSH2, MSH6 and PMS2 was evaluated by immunohistochemistry. Correlations of KRAS and BRAF mutation status and the expression status of MMR proteins with age, gender, cancer stage, location, and histology were analyzed. Correlations between KRAS or BRAF mutations and MMR protein expression were also explored. RESULTS: The overall frequencies of KRAS and BRAF mutations were 37.9% and 4.4%, respectively. KRAS mutations were more common in patients ≥ 50 years old (39.8% vs 22% in patients < 50 years old, P < 0.05). The frequencies of BRAF mutants were higher in tumors from females (6.6% vs males 2.8%, P < 0.05), located in the right colon (9.6% vs 2.1% in the left colon, 1.8% in the rectum, P < 0.01), with mucinous differentiation (9.8% vs 2.8% without mucinous differentiation, P < 0.01), or being poorly differentiated (9.5% vs 3.4% well/moderately differentiated, P < 0.05). MMR deficiency was strongly associated with proximal location (20.5% in the right colon vs 9.2% in the left colon and 5.1% in the rectum, P < 0.001), early cancer stage (15.0% in stages I-II vs 7.7% in stages III-IV, P < 0.05), and mucinous differentiation (20.2% vs 9.2% without mucin, P < 0.01). A higher frequency of MLH1/PMS2 loss was found in females (9.2% vs 4.4% in males, P < 0.05), and MSH2/MSH6 loss tended to be seen in younger (<50 years old) patients (12.0% vs 4.0% ≥ 50 years old, P < 0.05). MMR deficient tumors were less likely to have KRAS mutations (18.8% vs 41.7% in MMR proficient tumors, P < 0.05) and tumors with abnormal MLH1/PMS2 tended to harbor BRAF mutations (15.4% vs 4.2% in MMR proficient tumors, P < 0.05). CONCLUSION: The frequency of sporadic CRCs having BRAF mutation, MLH1 deficiency and MSI in Chinese population may be lower than that in the Western population.

Mast cells or not? - CD117 positive cells in esophageal leiomyoma.

The presence of CD117 positive cells in esophageal leiomyoma may lead to a misdiagnosis of GIST. We reviewed 46 esophageal tumors which were smooth muscle tumors or GIST. Based on morphology, immunohistochemistry and mutation analysis, there were 44 (95.6%) leiomyomas, 1 (2.2%) leiomyosarcoma, and 1 (2.2%) GIST. Variable numbers of CD117 positive cells were seen in all leiomyomas. Tryptase immunostaining identified mast cells in 93.2% (41/44) of leiomyomas, and the number of mast cells per tumor decreased significantly from tumors of the upper esophagus to the esophageal-gastric junction (p<0.01). Immunofluorescence study further confirmed the presence of two types of CD117 positive spindle cells which included spindle-shaped mast cells and DOG-1-positive interstitial cells of Cajal. This is the first study to systemically review mast cells in esophageal leiomyomas and tumors which may be included in the differential diagnosis. We demonstrate that both spindled mast cells and hyperplastic interstitial cells of Cajal are present within esophageal leiomyomas. The immunoreactivity of these cells with CD117 may suggest a diagnosis of GIST, but the presence of mast cells itself supports a diagnosis of esophageal leiomyoma.

Two three-dimensional lanthanide frameworks exhibiting luminescence increases upon dehydration and novel water layer involving in situ decarboxylation.

Two three-dimensional polymeric Tb(III) and Yb(III) frameworks, namely, {[Tb3(Hptc)(ptc)(pdc)(H2O)6]·2H2O}n (1) and {[Yb2(ptc)(ox)(H2O)5]·7H2O}n (2) (H4ptc = pyridine-2,3,5,6-tetracarboxylic acid, H2pdc = pyridine-3,5-dicarboxylic acid, ox = oxalate), have been synthesized by a hydrothermal method and characterized by infrared spectra, elemental analysis, powder X-ray diffraction, thermogravimetric analysis, and single-crystal X-ray diffraction. Framework 1 shows an interesting three-dimensional (8,8)-connected net with a Schläfli symbol of (3(3)·4(18)·5(5)·6(2))2(3(6)·4(14)·5(7)·6), while 2 exhibits an unusual (4,8)-connected sqc21 net with a Schläfli symbol of (3(2)·4(2)·5(2))(3(4)·4(8)·5(12)·6(4)). Luminescence studies of 1 reveal that the luminescence intensity increases when the framework is dehydrated.

A modified GEWF solution is cost-saving and effective for lymph node retrieval in resected colorectal carcinoma specimens.

Lymph node (LN) retrieval is important for proper staging of colorectal carcinoma. Although various assistant techniques were recommended to facilitate LN identification, most of them were unavoidably time-consuming, resource intensive and costly. We prepared a modified GEWF solution (RE-GEWF) by use of recycled alcohol and a familiar dye, eosin and investigated its efficacy on 55 colorectal carcinoma specimens. Of the 55 studied cases, 33 of them with <12 LNs (Group A) and 22 with ≥12 LNs were detected (Group B) before RE-GEWF treatment. All were subsequently treated with RE-GEWF for 14-16h and were inspected again for LNs. The number of LNs revealed before and after RE-GEWF treatment was 539 and 476 respectively. The mean number of LNs per cases increased from 9.80±6.27 to 18.43±8.77. Twelve accessory LN metastases were found in 9 cases. Upgrade of pN stage was only present in 7 of the Group A cases. The results show that RE-GEWF is as effective as other reported LN revealing solutions. Use of RE-GEWF not only can assure the quality of LN detection, but also minimize the cost and reduce the release of waste.

[Improvement of standardization and accuracy of medical imaging and pathological diagnosis for better diagnosis and treatment of rectal cancer].

Rectal cancer is one of the most common malignancies in human. Because rectal cancer locates in the narrow pelvis and is close to many complicated anatomic structures, seeking R0 resection and decreasing the positive rate of circumferential resection margin become the focus of concern for surgeons. The authors review the diagnosis standard of rectal cancer in AJCC TNM cancer staging (seventh edition) and guideline of College of American Pathologists, and propose the concept of "diagnosis priority using the standardized methods". Selecting the correct medical imaging and pathology diagnosis methods is the key to improve the standardized and individualized comprehensive therapy.

[Clinicopathologic features, diagnosis and treatment with solid-pseudopapillary tumor of the pancreas: a report of 33 cases].

OBJECTIVE: To study the clinicopathologic and immunohistochemical features, biological behavior, diagnosis and treatment of solid pseudopapillary tumor of the pancreas (SPTP). METHODS: A retrospective clinical and clinicopathologic analysis was made on 33 cases of SPTP admitted from May 2001 to 2010 July. There were 7 male and 26 female patients, aging from 13 to 66 years with a mean of 34.3 years. RESULTS: The tumor was located in pancreatic head of 10 patients, in pancreatic neck of 5 patients, in pancreatic body and tail of 18 patients. Of the 33 patients treated with surgery, 8 underwent simple resection of pancreatic tumor, 6 underwent pancreaticoduodenectomy, 3 underwent tumor resection plus pancreaticojejunostomy, 1 underwent tumor resection plus pancreaticogastrostomy, 11 underwent distal pancreatectomy, 4 underwent distal pancreatectomy plus spleen resection (1 underwent mesohepatectomy for hepatic metastasis). Sixteen of the 33 operations were completed by laparoscopy. Histologically, tumors were composed of papillary and microcystic solid structures, with uniformed population of cells. The pancreas and blood vessels invasion were identified in 3 cases, one of them was combined with liver metastasis, and they are male. Immunohistologically, the tumors were positive for α1-antitrypsin, α1-antichymotrypsin, ß-catenin, CD10, CD56 and vimentin (all cases), neuron-specific enolase (3 cases), synaptophysin (6 cases), chromogranin A (4 cases), progesterone receptor (28 cases), estrogen receptor (3 cases), S-100 (6 cases). Totally 33 cases were followed up with a median period of 49 months without tumor recurrence. CONCLUSIONS: SPTP is of low graded malignancy. It primarily affects young women. It may be located in any part of pancreas. Immunohistochemistry is very important for the diagnosis and differential diagnosis of SPTP. Surgical resection is recommended as the treatment of choice. Laparoscopic distal pancreatectomy or tumor resection is feasible and safe for some selected patients, and the prognosis is good.

[A clinical study on multi-disciplinary team and surgery for resectable colorectal cancer with liver metastases].

OBJECTIVES: To analyze the survival outcomes of the surgery for colorectal cancer with liver metastases (CRCLM), and study the mode of multi-disciplinary team (MDT) for CRCLM. METHODS: The retrospective analysis was conducted for 38 patients with CRCLM received MDT management and surgical treatment from January 2009 to August 2011. The peri-operative and survival outcomes of MDT and surgery were evaluated. RESULTS: All the cases met the present criteria of resetability for CRCLM, but only 4 cases (10.5%) met the previous one. Coloproctectomy and hepatectomy were performed in all cases, with 39 colorectal neoplasms and 155 liver lesions removed. One case died of postoperative septic shock. Colorectal and hepatic specific complications were absent in the others patients except one case of biliary leak which was treated with conservative management. Neoadjuvant chemotherapy was arranged in 13 cases. Adjuvant chemotherapy was administered for every patient. After a mean follow-up of (22 ± 10) months according to the finding time of liver metastases, recurrence and metastases were observed in 16 cases and 6 cases died of late-stage cachexia. The 1-, 2- and 3-overall survival rate were 94.4%, 85.3% and 75.8% respectively, and the 1-, 2- and 3-disease-free survival rate were 70.1%, 54.2% and 54.2% respectively. CONCLUSIONS: MDT mode for resectable CRCLM is recommendable. Surgical resection of CRCLM is feasible and safe, which seems to achieve favourable short-middle oncologic outcomes. And long-term survival is expected.

[Initial research on Fourier transform infrared spectroscopy for the diagnosis of colon neoplasms].

To explore the feasibility of Fourier transform infrared spectrometry (FTIR) for the diagnosis of colon neoplasms, fresh samples of eighteen cancers and ten adenomas were collected during colon surgery and were measured by FTIR via probe of attenuated total reflection (ATR). The peak position and the intensity of all bands were measured and compared between the malignant and benign groups. Results show that the FTIR of malignant neoplasm was different from that of benign one. (1) For the bands related to lipid: The ratio of I2 925 /I1 460 (p = 0.018) and I1 740/I1 460 (p = 0.009) decreased in cancer FTIR spectrum, indicating the lower relative quantity of lipid in malignant neoplasm. (2) For the bands related to protein: The ratios of I3 375/ I1 460 (p = 0.012) and I1 550/I1 460 (p = 0.041) increased in cancer, which shows that the relative quantity of protein was more in cancer than that in adenoma. (3) For the band related to nucleic acid: In malignant tissue the peak position in 1 080 cm(-1) shifted toward a higher wave number (p = 0.039), compared with that in benign one. And the ratio of I1 083/I1 460 increased significantly (p = 0.036), illustrating the higher relative quantity of nucleic acid to lipids in malignancy. (4) The peak position of 1 305 cm(-1) shifted to a lower wavenumber (p = 0.041), which should be determined in further research It is concluded that our initial research showed that the FTIR maybe develops into a promising method for rapid differential diagnosis of colon malignant and benign neoplasms.

[Expression of co-stimulators in ulcerative colitis and its pathologic significance].

OBJECTIVE: To study the expression and localization of co-stimulators in the mucosa of patients with ulcerative colitis (UC), and to explore its role in the pathogenesis of UC. METHODS: Expression of co-stimulators CD86 and inducible co-stimulator (ICOS) was studied by immunohistochemistry on paraffin-embedded mucosal tissue from patients with active UC (64 cases), inactive UC (51 cases) and normal controls (20 cases). Immunostaining for CD28 was also carried out on frozen fresh mucosal tissue sampled from patients with active UC (7 cases), inactive UC (2 cases) and normal controls (5 cases). In addition, expression of CD4, CD8 and CD20 were also examined. RESULTS: In active UC, increased expression of CD86 was not only observed in lamina propria mononuclear cells but also in the intestinal epithelial cells, as compared with inactive UC and the normal controls (P < 0.01). Increased ICOS expression in lamina propria mononuclear cells was detected in active UC, as compared with inactive UC and the normal controls (P < 0.01). Increased ICOS expression in intestinal epithelial cells was also seen in active UC, as compared with that of inactive UC (P < 0.01). The expression of CD86 was higher in inactive UC than in the normal controls (P < 0.05 or P < 0.01). However, the expression of ICOS showed no statistically significant difference between inactive UC and normal controls. Increased expression of CD28 in active UC, compared with that in inactive UC and normal controls, was also noticed (P < 0.05 or P < 0.01). The number of CD4 or CD8-positive intraepithelial lymphocytes and lymphocytes infiltrating in the lamina propria and small vessel walls was much higher in active UC than in inactive UC and normal controls (P < 0.01). Moreover, the ratio of CD4/CD8 was highest in active UC (P < 0.01). The number of CD20-positive B lymphocytes in lamina propria was also higher in active UC than in inactive UC and normal controls (P < 0.01). CONCLUSIONS: In active UC, CD86 and ICOS were over-expressed in the intestinal epithelial cells and lamina propria mononuclear cells. The phenomenon suggests that abnormal expression of co-stimulators may contribute to the deregulation of acquired immune responses in UC.