Objective To investigate the effect of grape seed proanthocyanidins(GSPs)on nuclear factor erythroid 2-related factor 2(Nrf2)antioxidant system and mitochondrial biosynthesis in testes of arsenic-exposed mice.Methods ICR mice were randomly divided into four groups:Control group,model group,GSPs group and experimental group.The mice in the model group and the experimental group drank sodium arsenite solution(10 mg·L-1 arsenic)to induce testicular injury.GSPs group and experimental group were given 100 mg·kg-1 GSPs by gavage,control group and model group were given equal volume of distilled water by gavage once a day for 8 weeks.The histological parameters of testes were measured by hematoxylin-eosin(HE)staining.The contents of malondialdehyde(MDA),superoxide dismutase(SOD)and adenosine triphosphate(ATP)in testicular tissue were determined by kit method.The expression levels of heme oxygenase 1(HO-1)and quinone oxidoreductase 1(NQ01)were detected by real-time quantitative reverse transcription polymerase chain reaction(RT-PCR).The expression of Nrf2 protein in testicular tissue was detected by immunohistochemistry.The expressions of mitochondrial synthesis-related proteins were detected by Western blot.Results The diameters of seminiferous tubules in control group,model group,GSPs group and experimental group were(184.32±14.14),(170.41±10.70),(186.87±8.03)and(181.70±9.15)μm;the contents of MDA were(2.30±0.26),(3.28±0.64),(2.32±0.40)and(2.74±0.31)nmol·mg-1;the proportions of Nrf2 positive cells were(46.50±11.98)％,(22.33±8.82)％,(51.67±12.44)％and(39.83±8.35)％;the mRNA expression levels of HO-1 were 1.00±0.21,0.51±0.10,1.00±0.28 and 0.80±0.06;the mRNA expression levels of NQO1 were 1.00±0.18,0.59±0.11,1.09±0.28 and 0.81±0.08;the contents of ATP were(491.83±67.16),(368.81±69.93),(512.44±70.96)and(472.20±68.24)μmol·g-1;the relative expression levels of PGC-1α protein were 1.00±0.06,0.22±0.03,0.94±0.05 and 0.48±0.05;the relative expression levels of TFAM were 1.00±0.07,0.32±0.05,0.80±0.05 and 0.67±0.06.The above indexes in the experimental group were statistically significant compared with the model group(all P＜0.05,P＜0.01).Conclusion GSPs has a protective effect against arsenic-induced testicular injury in mice by activating the Nfr2 antioxidant system and promoting mitochondrial biosynthesis.

ObjectiveTo explore whether miR-375 regulates the malignant characteristics of osteosarcoma (OS) by influencing the expression of MMP13. MethodsPlasmid DNAs and miRNAs were transfected into OS cells and HEK293 cells using Lipofectamine 3000 reagent. Real-time quantitative polymerase chain reaction was performed to measure the expression of miR-375 and MMP13 in OS patients and OS cells. Western blot was performed to analyze the MMP13 protein in the patients with OS and OS cells. The targeting relationship between miR-375 and MMP13 was analyzed by luciferase assay. Migration and invasion were analysed by heal wound and transwell assays, respectively. ResultsmiR-375 expression in OS tissues was lower than that in normal tissues. The expression of MMP13 was upregulated in OS tissues. MMP13 expression was negatively correlated withmiR-375 expression in patients with OS. Migration and invasion were significantly inhibited in OS cells with the miR-375 mimic compared with OS cells with the miRNA control. MMP13 partially reversed the inhibition of migration and invasion induced by miR-375 in the OS cells. ConclusionmiR-375 attenuates migration and invasion by downregulating the expression of MMP13 in OS cells.

This data article describes the"Typical Regional Activity Patterns"(TRAP)dataset,which is based on the Tackling Key Problems in Air Pollution Control Program.In order to explore the interaction between air pollution and physical activity,we collected activity patterns of 9,221 residents with different occupations and lifestyles for three consecutive days in typical regions(Jinan and Baoding)where air pollutant concentrations were higher than those in neighboring areas.The TRAP dataset consists of two aspects of information:demographic indicators(personal information,occupation,personal habits,and living situation)and physical activity pattern data(activity location and intensity);additionally,the exposure measures of physical activity patterns are included,which data users can match to various endpoints for their specific purpose.This dataset provides evidence for exploring the attributes of activity patterns of residents in northern China and for interdisciplinary researchers to develop strategies and measures for health education and health promotion.

Objective To develop a medical positive pressure protective suit for long-voyage aeromedical evacuation to realize protective isolation and drinking water and energy supply for medical personnel during long-voyage aeromedical evacuation of respiratory infectious disease patients.Methods The medical positive pressure protective suit had a one-piece structure,with its main part made of hydroentangled non-woven fabric,head and forebreast parts made of amorphous polyethylene terephthalate anti-fog material and wearing-and taking-off parts sealed with zipper and autohesion,which was equipped with a portable positive pressure air supply device,an airborne centralized positive pressure air supply device and a monitoring and warning device.The portable positive pressure air supply device was fixed in the back of the suit at the waist,the airborne device was made by modifying the commercially available positive pressure air supply fan,and the monitoring and warning device monitored the air supply volume of the fan,the battery power and the pressure inside the suit.Results The suit behaved well in protection,clean fresh air supply without time limitation and facilitating hydration and energy replenishment of medical personnel by forming three activity spaces.Conclusion The suit developed can continuously provide a clean and comfortable microenvironment,meeting the requirements of medical personnel for protection and hydration and energy replenishment during long-voyage aeromedical evacuation.[Chinese Medical Equipment Journal,2024,45(11):113-116]

Objective To evaluate the clinical application effect of fracture liaison service(FLS)mode after percutaneous vertebroplasty(PVP)/percutaneous kyphoplasty(PKP)for thoracolumbar fragility fracture.Methods A prospective study was conducted,and 762 patients with thoracolumbar fragility fracture who underwent PVP/PKP in the department of orthopedics in our hospital from January 2018 to May 2021 were included and divided into the control group(374 cases)and the observation group(388 cases)according to the random number table method.Patients in the control group received routine osteoporosis intervention,while the patients in the observation group implemented FLS through Blue Bull Medical Care or Chronic Health APP on the basis of the control group to systematically manage the osteoporosis treatment after discharge.The follow-up lasted for 12 months,and the 8-item Morisky medication adherence scale(MMAS-8)score,pain visual analogue scale(VAS)score,Oswestry disability index(ODI)score and Hamilton depression rating scale(HAMD)score at discharge,and 6 months and 12 months after discharge of the two groups were compared.The incidences of re-fracture and constipation 6 months and 12 months after discharge of the two groups were compared.The Cobb angle and bone mineral density T-value of injured vertebrae 6 months and 12 months after discharge of the two groups were compared.Results There was no statistically significant difference in the MMAS-8 score,VAS score,ODI score or HAMD score at discharge of patients between the two groups(P>0.05).The VAS score,ODI score and HAMD score 6 months and 12 months after discharge in the observation group were lower than those in the control group(P<0.05),the MMAS-8 score in the observation group was higher than that in the control group(P<0.05),and the incidences of re-fracture and constipation in the observation group were lower than those in the control group(P<0.05).There was no statistically significant difference in the Cobb angle of injured vertebrae 12 months after discharge of patients between the two groups(P>0.05).The bone mineral density T-value 12 months after discharge in the observation group was higher than that in the control group(P<0.05).Conclusion The FLS mode can significantly improve the medication compliance of patients,relieve pain,depression and constipation,improve bone mineral density,and significantly reduce the incidence of vertebral re-fracture in patients after vertebral augmentation surgery;however,it has no significant effect on the Cobb angle of injured vertebrae.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective: Compare and analyze the results of the domestic Lanyi AH600 glycated hemoglobin analyzer and other different detection systems to understand the comparability of the detection results of different detectors, and establish the best cut point of Lanyi AH600 determination of haemoglobin A1c (HbA1c) in the diagnosis of diabetes. Methods: Multi center cohort study was adopted. The clinical laboratory departments of 18 medical institutions independently collected test samples from their respective hospitals from March to April 2022, and independently completed comparative analysis of the evaluated instrument (Lanyi AH600) and the reference instrument HbA1c. The reference instruments include four different brands of glycosylated hemoglobin meters, including Arkray, Bio-Rad, DOSOH, and Huizhong. Scatter plot was used to calculate the correlation between the results of different detection systems, and the regression equation was calculated. The consistency analysis between the results of different detection systems was evaluated by Bland Altman method. Consistency judgment principles: (1) When the 95% limits of agreement (95% LoA) of the measurement difference was within 0.4% HbA1c and the measurement score was≥80 points, the comparison consistency was good; (2) When the measurement difference of 95% LoA exceeded 0.4% HbA1c, and the measurement score was≥80 points, the comparison consistency was relatively good; (3) The measurement score was less than 80 points, the comparison consistency was poor. The difference between the results of different detection systems was tested by paired sample T test or Wilcoxon paired sign rank sum test; The best cut-off point of diabetes was analyzed by receiver operating characteristic curve (ROC). Results: The correlation coefficient R² of results between Lanyi AH600 and the reference instrument in 16 hospitals is≥0.99; The Bland Altman consistency analysis showed that the difference of 95% LoA in Nanjing Maternity and Child Health Care Hospital in Jiangsu Province (reference instrument: Arkray HA8180) was -0.486%-0.325%, and the measurement score was 94.6 points (473/500); The difference of 95% LoA in the Tibetan Traditional Medical Hospital of TAR (reference instrument: Bio-Rad Variant II) was -0.727%-0.612%, and the measurement score was 89.8 points; The difference of 95% LoA in the People's Hospital of Chongqing Liang Jiang New Area (reference instrument: Huizhong MQ-2000PT) was -0.231%-0.461%, and the measurement score was 96.6 points; The difference of 95% LoA in the Taihe Hospital of traditional Chinese Medicine in Anhui Province (reference instrument: Huizhong MQ-2000PT) was -0.469%-0.479%, and the measurement score was 91.9 points. The other 14 hospitals, Lanyi AH600, were compared with 4 reference instrument brands, the difference of 95% LoA was less than 0.4% HbA1c, and the scores were all greater than 95 points. The results of paired sample T test or Wilcoxon paired sign rank sum test showed that there was no statistically significant difference between Lanyi AH600 and the reference instrument Arkray HA8180 (Z=1.665,P=0.096), with no statistical difference. The mean difference between the measured values of the two instruments was 0.004%. The comparison data of Lanyi AH600 and the reference instrument of all other institutions had significant differences (all P<0.001), however, it was necessary to consider whether it was within the clinical acceptable range in combination with the results of the Bland-Altman consistency analysis. The ROC curve of HbA1c detected by Lanyi AH600 in 985 patients with diabetes and 3 423 patients with non-diabetes was analyzed, the area under curve (AUC) was 0.877, the standard error was 0.007, and the 95% confidence interval 95%CI was (0.864, 0.891), which was statistically significant (P<0.001). The maximum value of Youden index was 0.634, and the corresponding HbA1c cut point was 6.235%. The sensitivity and specificity of diabetes diagnosis were 76.2% and 87.2%, respectively. Conclusion: Among the hospitals and instruments currently included in this study, among these four hospitals included Nanjing Maternity and Child Health Care Hospital in Jiangsu Province (reference instrument: Arkray HA8180), Tibetan Traditional Medical Hospital of TAR (reference instrument: Bio-Rad Variant Ⅱ), the People's Hospital of Chongqing Liang Jiang New Area (reference instrument: Huizhong MQ-2000PT), and the Taihe Hospital of traditional Chinese Medicine in Anhui Province (reference instrument: Huizhong MQ-2000PT), the comparison between Lanyi AH600 and the reference instruments showed relatively good consistency, while the other 14 hospitals involved four different brands of reference instruments: Arkray, Bio-Rad, DOSOH, and Huizhong, Lanyi AH600 had good consistency with its comparison. The best cut point of the domestic Lanyi AH600 for detecting HbA1c in the diagnosis of diabetes is 6.235%.
Pregnancy ; Child ; Humans ; Female ; Glycated Hemoglobin ; Cohort Studies ; Diabetes Mellitus/diagnosis* ; Sensitivity and Specificity ; ROC Curve

OBJECTIVE: To explore the association between the use of metformin and the risk of ischemic stroke in patients with type 2 diabetes. METHODS: A prospective cohort study was designed from the Fangshan family cohort in Beijing. According to metformin use at baseline, 2 625 patients with type 2 diabetes in Fangshan, Beijing were divided into metformin group or non-metformin group and the incidence of ischemic stroke between the different groups during follow-up was estimated and compared by Cox proportional hazard regression model. The participants with metformin were first compared with all the parti-cipants who did not use metformin, and then were further compared with those who did not use hypoglycemic agents and those who used other hypoglycemic agents. RESULTS: The patients with type 2 diabetes were with an average age of (59.5±8.7) years, and 41.9% of them were male. The median follow-up time was 4.5 years. A total of 84 patients developed ischemic stroke during follow-up, with a crude incidence of 6.4 (95%CI: 5.0-7.7) per 1 000 person-years. Among all the participants, 1 149 (43.8%) took metformin, 1 476 (56.2%) were metformin non-users, including 593 (22.6%) used other hypoglycemic agents, and 883 (33.6%) did not use any hypoglycemic agents. Compared with metformin non-users, the Hazard ratio (HR) for ischemic stroke in metformin users was 0.58 (95%CI: 0.36-0.93; P = 0.024). Compared with other hypoglycemic agents, HR was 0.48 (95%CI: 0.28-0.84; P < 0.01); Compared with the group without hypoglycemic agents, HR was 0.65 (95%CI: 0.37-1.13; P=0.13). The association between metformin and ischemic stroke was statistically significant in the patients ≥ 60 years old compared with all the metformin non-users and those who used other hypoglycemic agents (HR: 0.48, 95%CI: 0.25-0.92; P < 0.05). Metformin use was associated with a lower incidence of ischemic stroke in the patients with good glycemic control (0.32, 95%CI: 0.13-0.77; P < 0.05). In the patients with poor glycemic control, and the association was not statistically significant (HR: 0.97, 95%CI: 0.53-1.79; P>0.05). There was an interaction between glycemic control and metformin use on incidence of ischemic stroke (P_interaction < 0.05). The results of the sensitivity analysis were consistent with the results in the main analysis. CONCLUSION Among patients with type 2 diabetic in rural areas of northern China, metformin use was associated with lower incidence of ischemic stroke, especially in patients older than 60 years. There was an interaction between glycemic control and metformin use in the incidence of ischemic stroke.
Humans ; Male ; Middle Aged ; Aged ; Female ; Metformin/adverse effects* ; Diabetes Mellitus, Type 2/drug therapy* ; Cohort Studies ; Ischemic Stroke/complications* ; Prospective Studies ; Hypoglycemic Agents/adverse effects* ; Stroke/prevention & control* ; Retrospective Studies

Objective:To investigate the surgical efficacy and prognosis influencing factors of hilar cholangiocarcinoma based on multidisciplinary diagnosis and treatment.Methods:The retrospective cohort study was conducted. The clinicopathological data of 91 patients with hilar cholangiocarcinoma who underwent surgery in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School from April 2004 to April 2021 were collected. There were 59 males and 32 females, aged (61±10)years. Patients who were admitted from April 2004 to March 2014 underwent traditional surgical diagnosis and treatment, and patients who were admitted from April 2014 to April 2021 underwent multidisciplinary diagnosis and treatment. Observation indica-tors: (1) surgical situations; (2) postoperative situations; (3) postoperative pathological examina-tions; (4) postoperative prognosis analysis; (5) influencing factors of postoperative prognosis. Follow-up was conducted using telephone interview and outpatient examination. Patients were followed up once every 6 months after surgery to detect survival. The follow-up was up to April 2023. Measure-ment data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was conducted using the Mann-Whitney U test. Comparison of ordinal data was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test or Fisher exact probability. The Kaplan-Meier method was used to draw survival curve and calculate survival rate. The Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard model. Results:(1) Surgical situations. Of the 91 patients, there were 65 cases receiving hemi- or expanded hemi-hepatectomy, 13 cases receiving tri-hepatectomy, 9 cases receiving partial hepatectomy, 4 cases receiving extrahepatic bile duct resection. There were 24 cases receiving combined vein resection and reconstruction, 8 cases receiving combined pancreaticoduodenectomy, 6 cases receiving com-bined hepatic artery resection and reconstruction, including 24 cases receiving extended radical surgery (tri-hepatectomy, hepatic artery resection and reconstruction, hepatopancreaticoduodenec-tomy). The operation time, volume of intraoperative blood loss and intraoperative blood transfusion rate of 91 patients was (590±124)minutes, 800(range, 500?1 200)mL and 75.8%(69/91), respectively. Of the 91 patients, cases receiving extended radical surgery, the volume of intraoperative blood loss were 4, 650(range, 300?1 000)mL in the 31 patients who were admitted from April 2004 to March 2014, versus 20, 875 (range, 500?1 375)mL in the 60 patients who were admitted from April 2014 to April 2021, showing significant differences between them ( χ2=4.39, Z=0.31, P<0.05). (2) Post-operative situations. The postoperative duration of hospital stay and cases with postoperative infectious complications were (27±17)days and 50 in the 91 patients. Cases with abdominal infection, cases with infection of incision, cases with bacteremia and cases with pulmonary infection were 43, 7, 5, 8 in the 91 patients. One patient might have multiple infectious complications. Cases with bile leakage, cases with delayed gastric emptying, cases with chylous leakage, cases with liver failure, cases with pancreatic fistula, cases with intraperitoneal hemorrhage, cases with reoperation, cases dead during the postoperative 90 days were 30, 9, 9, 6, 5, 3, 6, 3 in the 91 patients. Cases with abdominal infection was 10 in the 31 patients who were admitted from April 2004 to March 2014, versus 33 in the 60 patients who were admitted from April 2014 to April 2021, showing a significant difference between them ( χ2=4.24, P<0.05). Cases dead during the postoperative 90 days was 3 in the 31 patients who were admitted from April 2004 to March 2014, versus 0 in the 60 patients who were admitted from April 2014 to April 2021, showing a significant difference between them ( P<0.05). (3) Post-operative pathological examinations. Of the 91 patients, cases with Bismuth type as type Ⅰ?Ⅱ, type Ⅲ, type Ⅳ, cases with T staging as Tis stage, T1 stage, T2a?2b stage, T3 stage, T4 stage, cases with N staging as N0 stage, N1 stage, N2 stage, cases with M staging as M0 stage, M1 stage, cases with TNM staging as 0 stage, Ⅰ stage, Ⅱ stage, Ⅲ stage, ⅣA stage, ⅣB stage, cases with R 0 radical resection, cases with R 1 or R 2 resection were 15, 46, 30, 1, 9, 25, 30, 26, 49, 36, 6, 85, 6, 1, 7, 13, 58, 6, 6, 63, 28. Cases with R 0 radical resection, cases with R 1 or R 2 resection were 15, 16 in the 31 patients who were admitted from April 2004 to March 2014, versus 48, 12 in the 60 patients who were admitted from April 2014 to April 2021, showing a significant difference between them ( χ2=9.59, P<0.05). (4) Postoperative prognosis analysis. Of the 91 patients, 3 cases who died within 90 days after surgery were excluded, and the 5-year overall survival rate and median overall survival time of the rest of 88 cases were 44.7% and 55 months. The 5-year overall survival rate was 33.5% in the 28 patients who were admitted from April 2004 to March 2014, versus 50.4% in the 60 patients who were admitted from April 2014 to April 2021, showing a significant difference between them ( χ2=5.31, P<0.05). Results of further analysis showed that the corresponding 5-year overall survival rate of cases without lymph node metastasis was 43.8% in the 16 patients who were admitted from April 2004 to March 2014, versus 61.6% in the 31 patients who were admitted from April 2014 to April 2021. There was a significant difference in the 5-year overall survival rate between these patients without lymph node metastasis ( χ2=3.98, P<0.05). The corresponding 5-year overall survival rate of cases with lymph node metastasis was 18.5% in the 12 patients who were admitted from April 2004 to March 2014, versus 37.7% in the 29 patients who were admitted from April 2014 to April 2021. There was no significant difference in the 5-year overall survival rate between these patients with lymph node metastasis ( χ2=2.25, P>0.05). (5) Influencing factors of postoperative prognosis. Results of multivariate analysis showed that poorly differentiated tumor and R 1 or R 2 resection were inde-pendent risk factors influencing prognosis after surgical treatment of hilar cholangiocarcinoma ( hazard ratio=2.62, 2.71, 95% confidence interval as 1.30?5.29, 1.30?5.69, P<0.05). Conclusions:Compared with traditional surgical diagnosis and treatment, treatment of hilar cholangiocarcinoma based on multidisciplinary diagnosis and treatment can expand surgical indications, reduce proportion of dead patients within 90 days after surgery, improve proportation of radical resection and long-term survival rate. Poorly differentiated tumor and R 1 or R 2 resection are independent risk factors influencing prognosis after surgical treatment of hilar cholangiocarcinoma.