GDF15: Immunomodulatory Role in Hepatocellular Carcinoma Pathogenesis and Therapeutic Implications.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths globally and the sixth most common cancer worldwide. Evidence shows that growth differentiation factor 15 (GDF15) contributes to hepatocarcinogenesis through various mechanisms. This paper reviews the latest insights into the role of GDF15 in the development of HCC, its role in the immune microenvironment of HCC, and its molecular mechanisms in metabolic dysfunction associated steatohepatitis (MASH) and metabolic associated fatty liver disease (MAFLD)-related HCC. Additionally, as a serum biomarker for HCC, diagnostic and prognostic value of GDF15 for HCC is summarized. The article elaborates on the immunological effects of GDF15, elucidating its effects on hepatic stellate cells (HSCs), liver fibrosis, as well as its role in HCC metastasis and tumor angiogenesis, and its interactions with anticancer drugs. Based on the impact of GDF15 on the immune response in HCC, future research should identify its signaling pathways, affected immune cells, and tumor microenvironment interactions. Clinical studies correlating GDF15 levels with patient outcomes can aid personalized treatment. Additionally, exploring GDF15-targeted therapies with immunotherapies could improve anti-tumor responses and patient outcomes.

The role of the mitochondrial ribosomal protein family in detecting hepatocellular carcinoma and predicting prognosis, immune features, and drug sensitivity.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors, with a slow onset, rapid progression, and frequent recurrence. Previous research has implicated mitochondrial ribosomal genes in the development, metastasis, and prognosis of various cancers. However, further research is necessary to establish a link between mitochondrial ribosomal protein (MRP) family expression and HCC diagnosis, prognosis, ferroptosis-related gene (FRG) expression, m6A modification-related gene expression, tumor immunity, and drug sensitivity. METHODS: Bioinformatics resources were used to analyze data from patients with HCC retrieved from the TCGA, ICGC, and GTEx databases (GEPIA, UALCAN, Xiantao tool, cBioPortal, STRING, Cytoscape, TISIDB, and GSCALite). RESULTS: Among the 82 MRP family members, 14 MRP genes (MRPS21, MRPS23, MRPL9, DAP3, MRPL13, MRPL17, MRPL24, MRPL55, MRPL16, MRPL14, MRPS17, MRPL47, MRPL21, and MRPL15) were significantly upregulated differentially expressed genes (DEGs) in HCC tumor samples in comparison to normal samples. Receiver-operating characteristic curve analysis indicated that all 14 DEGs show good diagnostic performance. Furthermore, TCGA analysis revealed that the mRNA expression of 39 MRPs was associated with overall survival (OS) in HCC. HCC was divided into two molecular subtypes (C1 and C2) with distinct prognoses using clustering analysis. The clusters showed different FRG expression and m6A methylation profiles and immune features, and prognostic models showed that the model integrating 5 MRP genes (MRPS15, MRPL3, MRPL9, MRPL36, and MRPL37) and 2 FRGs (SLC1A5 and SLC5A11) attained a greater clinical net benefit than three other prognostic models. Finally, analysis of the CTRP and GDSC databases revealed several potential drugs that could target prognostic MRP genes. CONCLUSION: We identified 14 MRP genes as HCC diagnostic markers. We investigated FRG and m6A modification-related gene expression profiles and immune features in patients with HCC, and developed and validated a model incorporating MRP and FRG expression that accurately and reliably predicts HCC prognosis and may predict disease progression and treatment response.

Transarterial chemoembolization with PD-(L)1 inhibitors plus molecular targeted therapies for hepatocellular carcinoma (CHANCE001).

There is considerable potential for integrating transarterial chemoembolization (TACE), programmed death-(ligand)1 (PD-[L]1) inhibitors, and molecular targeted treatments (MTT) in hepatocellular carcinoma (HCC). It is necessary to investigate the therapeutic efficacy and safety of TACE combined with PD-(L)1 inhibitors and MTT in real-world situations. In this nationwide, retrospective, cohort study, 826 HCC patients receiving either TACE plus PD-(L)1 blockades and MTT (combination group, n = 376) or TACE monotherapy (monotherapy group, n = 450) were included from January 2018 to May 2021. The primary endpoint was progression-free survival (PFS) according to modified RECIST. The secondary outcomes included overall survival (OS), objective response rate (ORR), and safety. We performed propensity score matching approaches to reduce bias between two groups. After matching, 228 pairs were included with a predominantly advanced disease population. Median PFS in combination group was 9.5 months (95% confidence interval [CI], 8.4-11.0) versus 8.0 months (95% CI, 6.6-9.5) (adjusted hazard ratio [HR], 0.70, P = 0.002). OS and ORR were also significantly higher in combination group (median OS, 19.2 [16.1-27.3] vs. 15.7 months [13.0-20.2]; adjusted HR, 0.63, P = 0.001; ORR, 60.1% vs. 32.0%; P < 0.001). Grade 3/4 adverse events were observed at a rate of 15.8% and 7.5% in combination and monotherapy groups, respectively. Our results suggest that TACE plus PD-(L)1 blockades and MTT could significantly improve PFS, OS, and ORR versus TACE monotherapy for Chinese patients with predominantly advanced HCC in real-world practice, with an acceptable safety profile.

Acute mesenteric ischemia secondary to oral contraceptive-induced portomesenteric and splenic vein thrombosis: A case report.

BACKGROUND: Mesenteric ischemia represents an uncommon complication of splanchnic vein thrombosis, and it is less infrequently seen in young women using oral contraceptives. Diagnosis is often delayed in the emergency room; thus, surgical intervention may be inevitable and the absence of thrombus regression or collateral circulation may lead to further postoperative ischemia and a fatal outcome. CASE SUMMARY: We report a 28-year-old female patient on oral contraceptives who presented with acute abdominal pain. Her physical examination findings were not consistent with her symptoms of severe pain and abdominal distention. These findings and her abnormal blood tests raised suspicion of acute mesenteric ischemia (AMI) induced by splanchnic vein thrombosis. Contrast-enhanced abdominal computed tomography revealed ischemia of the small intestine with portomesenteric and splenic vein thrombosis (PMSVT). We treated the case promptly by anticoagulation after diagnosis. We then performed delayed segmental bowel resection after thrombus regression and established collateral circulation guided by collaboration with a multidisciplinary team. The patient had an uneventful postoperative course and was discharged 14 d after surgery and took rivaroxaban orally for 6 mo. In subsequent follow-up to date, the patient has not complained of any other discomfort. CONCLUSION: AMI induced by PMSVT should be considered in young women who are taking oral contraceptives and have acute abdominal pain. Prompt anticoagulation followed by surgery is an effective treatment strategy.

Spectrum of Spondyloarthritis Among Chinese Populations.

PURPOSE OF REVIEW: This review aims to emphasize interesting and important new findings with a focus on the spectrum of spondyloarthritis (SpA) in China. RECENT FINDINGS: Over the past decade, significant advances have been made in the investigation of SpA epidemiology, the exploration of genetic and environmental risk factors, the identification of clinical features, and the updating of treatment protocols in the Chinese population. The prevalence of ankylosing spondylitis (AS) in China is 0.20-0.42%, and the prevalence of HLA-B27 in AS patients is 88.8-89.4%. HLA-B*2704 is the most common subtype in Chinese AS patients, followed by HLA-B*2705. HLA-A*01, more precisely HLA-A*01:01, may be associated with psoriatic arthritis (PsA). Tumor necrosis factor inhibitors and IL-17A inhibitors have been shown to be effective and safe for AS patients in China. Juvenile-onset AS is relatively rare, accounting for only 9.1% of the AS population. The prevalence of arthritis related to inflammatory bowel disease is 6.9 to 7.2%. A Chinese study showed that the most frequently prescribed medication was methotrexate (66.4%). Biological agents were prescribed in only16.4% of patients with PsA. This review summarizes the latest research in the epidemiology, pathogenesis, clinical manifestations, and management of SpA among Chinese populations. Multiple HLA associations with SpA have also been described, and it is hoped that discoveries of such ethnic-specific risk factor(s) and understanding of their pathological mechanisms may potentially lead to newer targeted therapies for the Chinese populations worldwide.

Corosolic acid inhibits tumour growth without compromising associating liver partition and portal vein ligation-induced liver regeneration in rats.

BACKGROUND: Associating liver partition and portal vein ligation (ALPPS) technique is a promising strategy for unresectable primary liver tumours without sufficient future liver remnants (FLRs). OBJECTIVE: Our study explored the effect of corosolic acid (CA) on inhibiting tumour growth without compromising ALPPS-induced liver regeneration. METHODS: The ALPPS procedure was performed in Sprague-Dawley rats with orthotopic liver cancer. Blood, tumour, and FLR samples were collected, and the effect of CA on the inhibition of tumour progression and ALPPS-induced liver regeneration, and its possible mechanism, were investigated. RESULTS: The tumour weight in the implantation/ALPPS group was higher than in the implantation without ALPPS group (p < .05), and the tumour weight in the implantation/ALPPS/CA group was lower than in the implantation/ALPPS group (p < .05). On postoperative day 15, the hepatic regeneration rate, and the expression of Ki67+ hepatocytes in the FLRs had increased significantly in the group that underwent ALPPS. The number of cluster of differentiation (CD) 86+ macrophages markedly increased in the FLRs and in the tumours of groups that underwent the ALPPS procedure. Additionally, the number of CD206+ macrophages was higher than the number of CD86+ macrophages in the tumours of the implantation and the implantation/ALPPS groups (p < .01, respectively); however, the opposite results were observed in the CA groups. The administration of CA downregulated the expression of transforming growth factor-beta (TGF-ß), CD31, and programmed cell death protein 1 (PD-1) but increased the number of CD8+ lymphocytes in tumours. CONCLUSION: Corosolic acid inhibits tumour growth without compromising ALPPS-induced liver regeneration. This result may be attributed to the CA-induced downregulation of PD-1 and TGF-ß expression and the increased CD8+ lymphocyte infiltration in tumour tissue associated with the suppression of M2 macrophage polarisation. Key MessagesThis study aimed to investigate the effect of CA on ALPPS-induced liver regeneration and hepatic tumour progression after ALPPS-induced liver regeneration.Corosolic acid inhibits tumour growth without compromising ALPPS-induced liver regeneration. This result may be attributed to the CA-induced downregulation of PD-1 and TGF-ß expression and the increased CD8+ lymphocyte infiltration in tumour tissue associated with the suppression of M2 macrophage polarisation.

Biological effects of corosolic acid as an anti-inflammatory, anti-metabolic syndrome and anti-neoplasic natural compound.

Accumulating evidence has indicated that corosolic acid exerts anti-diabetic, anti-obesity, anti-inflammatory, anti-hyperlipidemic and anti-viral effects. More importantly, corosolic acid has recently attracted much attention due to its anticancer properties and innocuous effects on normal cells. Furthermore, the increasing proportion of obese and/or diabetic populations has led to an epidemic of non-alcoholic fatty liver disease (NAFLD), which frequently progresses to hepatocellular carcinoma (HCC). Evidence has indicated that NAFLD is closely associated with the development of HCC and comprises a high risk factor. The present review summarizes the anticancer effects of corosolic acid in vitro and in vivo, and its related molecular mechanisms. It also describes the inhibitory effects of corosolic acid on the progression of NAFLD and its associated molecular mechanisms, providing guidance for future research on corosolic acid in NAFLD-related HCC prevention and treatment. To the best of our knowledge, a review of corosolic acid as an anticancer agent has not yet been reported. Due to its multitargeted activity in cancer cells, corosolic acid exerts anticancer effects when administered alone, and acts synergistically when administered with chemotherapeutic drugs, even in drug-resistant cells. In addition, as a novel tool to treat metabolic syndromes, corosolic acid uses the same mechanism in its action against cancer as that used in the progression of NAFLD-related HCC. Therefore, corosolic acid has been suggested as an agent for the prevention and treatment of NAFLD-related HCC.

Enhanced therapeutic effect of transcatheter arterial chemoembolization combined with radioactive I-125 seed implantation on liver cancer.

The present study aimed to evaluate the therapeutic effect of transcatheter arterial chemoembolization (TACE) combined with radioactive I-125 (iodine-125) seed implantation on liver cancer. A total of 38 liver cancer patients in the combined treatment group were treated with lobaplatin-TACE combined with radioactive I-125 seed implantation, while 45 patients in the TACE group were treated only with lobaplatin-TACE. Patients were followed up for survival time, and the liver function, change in α-fetoprotein (AFP) and side effects were evaluated. The average survival time of patients was 6.1 months in the TACE group and 8.2 months in the combined treatment group, and the overall survival was significantly different between the two groups (P<0.05). The response rate of lesions in the combined treatment group was superior to that observed in the TACE group, and the change in AFP in the TACE group was smaller than that in the combined treatment group. Improvement in the effects on most liver function indices in the combined treatment group were better than those in the TACE group. In addition, there were no differences in the side effects experienced between the two groups. Results of this study indicate that the effect of TACE combined with radioactive I-125 seed implantation is superior to that of TACE alone for the treatment of liver cancer, which can further benefit patients.

[Short-term effectiveness of acetabular reconstruction with three-dimensional printed trabecular metal pads in hip revision].

OBJECTIVE: To investigate the short-term effectiveness of three-dimensional (3D) printed trabecular metal pads for Paprosky type Ⅲ acetabular defect in hip revision. METHODS: Between August 2014 and December 2015, the 3D printed trabecular metal pads were used to repair Paprosky type Ⅲ acetabular defects and reconstruct the annular structure of the acetabulums in 5 cases of primary hip revision. There were 3 males and 2 females, aged from 50 to 72 years, with an average age of 66 years. The time from initial replacement to revision was 10 to 18 years, with an average of 14.4 years. The types of prostheses in primary replacement were non-cemented in 3 cases and cemented in 2 cases. The types of acetabular bone defects were Paprosky type ⅢA in 3 cases and Paprosky type ⅢB in 2 cases. The preoperative Harris score was 34.23±11.67. The height of rotation center of affected hip was (38.17±8.87) mm and the horizontal position was (35.62±9.12) mm. RESULTS: The operation time was 120-180 minutes, with an average of 142 minutes. The intraoperative bleeding volume was 800-1 700 mL, with an average of 1 100 mL. Five patients were followed up 18-24 months (mean, 21 months). At last follow-up, the Harris score was 79.82±8.70, which was significantly higher than that before operation (t=16.991, P=0.000). At 1 week after operation, the abduction angle of acetabular cup was 38-42° (mean, 39.4 °) and the anteversion angle was 13-18 ° (mean, 14.6°). The height and horizontal position of rotation center of affected hip were (22.08±8.33) mm and (29.03±6.28) mm, respectively, showing significant differences when compared with those before operation (P<0.05); there was no significant difference when compared with those of healthy hip [(28.62±7.73), (27.29±4.22) mm] (P>0.05). During the follow-up, there was no complication such as prosthesis loosening, dislocation, or periprosthetic fracture. CONCLUSION: In hip revision, 3D printed trabecular metal pads can repair Paprosky type Ⅲ acetabular defect, reconstruct the structure of acetabulum, provide a stable supporting structure for the acetabular cup, reconstruct the relatively normal rotation center of the hip joint, avoid iatrogenic bone loss, and achieve satisfactory functional recovery of the hip. The long-term effectiveness needs further follow-up.

NAFLD Induction Delays Postoperative Liver Regeneration of ALPPS in Rats.

BACKGROUND: Associating liver partition and portal vein ligation (ALPPS) is a promising two-step hepatectomy that is beneficial for accumulative regeneration of the future liver remnant (FLR) and avoids postoperative liver failure. AIMS: Our study aimed to evaluate whether nonalcoholic fatty liver disease affected the liver regeneration induced by ALPPS. METHODS: Sprague-Dawley rats fed a high-fat diet were used to construct the NAFLD model. ALPPS were performed, and blood and future liver remnant samples were collected at postoperative days 1 (POD1), POD3, and POD7. RESULTS: The hepatic regeneration rate (HRR) of ALPPS was higher than that of portal vein ligation (PVL) at POD3 and POD7 (p < 0.05), and the number of Ki-67-positive hepatocytes (POD3) and CD68-positive Kupffer cells (POD7) per visual field was higher in the ALPPS group than in the PVL group (p < 0.05). The serum TNF-α, hepatocyte growth factor protein, and the serum IL-6 level were higher in the ALPPS group than in the PVL group at POD3 and POD7. Compared with those of the standard laboratory diet (SLD)-fed rats, the rats with NAFLD exhibited a decrease in the HRR, Ki-67-positive hepatocytes, and CD68-positive Kupffer cells in the FLR. The number of CD68-positive Kupffer cells was lower in rats with NAFLD than that in SLD-fed rats; noteworthily, the serum level of IL-6 and TNF-α changed dramatically after surgeries. CONCLUSIONS: NAFLD induction delayed liver regeneration induced by the ALPPS procedure, which might be associated with hepatocyte proliferation and the number of Kupffer cells.

Spinal Gout Without Spinal Symptom in a Junior School Student: A Case Report.

STUDY DESIGN: Case report. OBJECTIVE: We report a case of a 16-year-old boy with intermittent and migratory polyarthralgia, who made a diagnostic dilemma. SUMMARY OF BACKGROUND DATA: Spinal involvement without spinal symptom in gout seems to be rare. However, the relationship of spinal gout to symptoms is poorly understood. METHODS: Description of the case report. RESULTS: Laboratory findings cannot explain his symptoms; however, a computed tomography of the pelvis revealed the presence of space-occupying lesion involving the left side of spine at L5-S1 level, and the later biopsy revealed that was a urate crystal, which help us make the diagnosis of spinal gout. CONCLUSION: Gout can be a cunning disease which has various manifestations, and spinal involvement can be asymptomatic. LEVEL OF EVIDENCE: 5.

Aspiration thrombectomy using a large-size catheter for acute lower extremity deep vein thrombosis.

OBJECTIVE: This study retrospectively evaluated the safety and efficacy of aspiration thrombectomy using a large-size catheter for acute lower extremity deep vein thrombosis (DVT). METHODS: All patients who underwent aspiration thrombectomy using 9F or 10F catheters for acute lower extremity DVT were included and analyzed. Aspiration thrombectomy was performed in all patients. Additional intravenous thrombolysis was performed in patients with residual thrombus, and stent placement was performed in patients with iliac vein compression syndrome. RESULTS: From October 2010 to September 2013, the study enrolled 68 patients (37 women, 31 men) with a mean age of 61.7 ± 7.8 years (range, 24-86 years). All patients presented with lower extremity swelling and pain, and the duration of symptoms ranged from 1 to 14 days. The DVTs involved popliteal-iliofemoral veins in 29 patients, iliofemoral veins in 31, and iliac veins in 8. Endovascular procedures were performed in all patients with a technical success rate of 100%. Aspiration alone was effective in 47 patients, and additional thrombolysis was required in the remaining 21. An additional stent was required in 32 patients. Significant improvement in presenting symptoms was achieved in all patients after the procedures, with a clinical success rate of 100%. There were no procedure-related or thrombolysis-related complications. The Villalta scores were <5 in 60 patients and from 5 to 9 in four patients. Primary and secondary patency rates were 89.1% (57 of 64) and 96.9% (62 of 64) at 1 year of follow-up. CONCLUSIONS: Aspiration thrombectomy using a large-size catheter is safe and effective for acute lower extremity DVT.

[CLINICAL FEATURES AND SURGICAL EFFECTIVENESS OF ANKLE FRACTURES INVOLVING Tillaux-Chaput IN ADULTS].

OBJECTIVE: To investigate the clinical features of ankle fractures involving Tillaux-Chaput in adults, and to observe the surgical effectiveness. METHODS: Between May 2009 and May 2013, 15 adult patients with ankle fractures involving Tillaux-Chaput were treated by open reduction and internal fixation. There were 12 males and 3 females, with an average age of 32 years (range, 19-45 years). The causes included sport injury (8 cases), traffic accident injury (5 cases), and falling injury from height (2 cases). The left ankle was involved in 5 cases and the right side in 10 cases. There were 2 open fractures (Gustilo type I) and 13 close fractures. Five patients had single Tillaux-Chaput fractures. The mean time between injury and surgery was 8.5 days (range, 3 hours to 15 days). According to the Lauge-Hansen classification, there were 9 cases of supination-external rotation, 5 cases of pronation-external rotation, and 1 case of pronation-abduction. RESULTS: Primary healing of incisions was obtained in 13 patients without infection and neurovascular injury; 2 patients had superficial infection which was cured after oral antibiotics and dressing change. All cases were followed up for 23 months on average (range, 13-36 months). X-ray films showed complete fracture healing at 10-16 weeks postoperatively (mean, 13 weeks) in all cases. The mean American Orthopaedic Foot and Ankle Society (AOFAS) score was 87 (range, 78-99), with an excellent and good rate of 80% (excellent in 9 cases, good in 3 cases, and fair in 3 cases). CONCLUSION: Open reduction and internal fixation for ankle fractures involving Tillaux-Chaput in adults can achieve excellent effectiveness.

A joint ROI extraction filter for computer aided lung nodule detection.

Extraction of regions of interest plays an important rule in computer aided lung nodules detection. However, because of the complex background and structure, accurate and robust extraction of ROIs in medical image still remains a problem. Aim at this problem, a two-stage operations joint filter: Hessian-LoB, is proposed. The first stage is blobs (which being taken as candidate ROIs) detection and the second stage is ROIs extraction. In the first stage, the derivatives of a Hessian matrix at multiple scales are convolved with input images to localize blobs. Then in the second stage, Laplacian of bilateral filter (LoB) is convolved with the detected blobs to extract the final ROIs. Experiments show that the proposed filter can deal with images with noise and low brightness contrast, and is effectively in ROI extraction for lung nodule detection.

Supplemental transcatheter arterial chemoembolization for hepatocellular carcinoma fed by collateral omental artery.

PURPOSE: To evaluate the efficacy and safety of supplemental transcatheter arterial chemoembolization (TACE) through the extrahepatic collateral omental artery (OA) for hepatocellular carcinoma (HCC). METHODS: We retrospective evaluated extrahepatic collateral OA on 34 patients, among 1826 patients with HCC who had undergone TACE. TACE of the OA was performed, and the dosage of emulsion was judged by tumor size and achievement of stagnant arterial flow. RESULTS: Blood supply from the OA was demonstrated at the initial TACE in 7 patients, and after several TACE (mean 2.8th) sessions in 27 patients. The technical success rate was 100%. Total occlusion of the OA collateral was achieved in 85.3%. On one month later, complete, more than 50% and less than 50% uptake of iodized oil in the tumor were in 12, 16, and 6 patients, respectively. Alpha-fetoprotein level 1 month later was significantly lower than pre-procedure (P<0.05). There was no serious complication that related to the omental embolization. The cumulative survival rates at 6, 12 months were 94.1%, 85.3%, respectively. CONCLUSION: TACE of the OA is safe and reduce the incidence of post-TACE recurrence and/or residual of HCC, and could improve the therapeutic effect of TACE in the treatment of HCC.

[Blood supply of pulmonary metastases and its clinical significance].

BACKGROUND & OBJECTIVE: Interventional treatment has been widely applied to primary lung carcinoma, but seldom applied to pulmonary metastases because the blood supply of pulmonary metastases has rarely been investigated, and the present understanding is controversial. This study was to explore the correlation of the clinical value of bronchial arterial chemotherapeutic infusion (BAI) combined bronchial arterial embolization (BAE) to the blood supply of pulmonary metastases. METHODS: Bronchial artery angiography was performed on 33 patients with pulmonary metastases to assess the blood supply and the distribution of pulmonary metastases. BAI was performed on hypovascular nodules, and BAE was performed on hypervascular nodules. RESULTS: Of the 89 metastatic nodules in the lungs of 33 patients, 63 (70.8%) were located in the mid-medial zone, and 26 (29.3%) in the lateral region of the lung; 56 had abundant blood supply, and 33 had poor blood supply. The blood supply of pulmonary metastases was correlated to the location of metastatic nodules. Most nodules in the mid-medial region had abundant blood supply, while most nodules in the lateral region had poor or had no blood supply (P<0.01). The blood supply of bronchial artery had no correlation to the volume of metastatic nodule (P>0.05). The curative efficacy of BAI and BAE was correlated to the blood supply of bronchial artery. The response rate was significantly higher in the hypervascular nodules treated with BAE than in the hypovascular nodules treated with BAI (71.4% vs. 42.4%, P<0.01). Most pulmonary metastases of hepatic cancer were hypervascular and the lipiodol deposited well in the nodules; during the follow-up, the nodules shrunk significantly and kept stable. CONCLUSIONS: Bronchial artery is the major feeding artery of pulmonary metastases. BAI and BAE are effective in treating pulmonary metastases with abundant blood supply.

[Determination of the content of wear metal in lubrication oil by ICP-AES].

An analytical method for determining wear metal elements directly by ICP-AES was proposed in this paper. The optimum condition was selected. The Conostan S-21 and Conostan 75 (oil-base standard samples) prepared by multi-element oil-base reserved standard samples were applied to make calibration curve. Oil samples were diluted 5 times by kerosene. The contents of wear metals in lubrication oil were determined by ICP-AES. The relative standard deviation (RSD) of all elements was less than 1%. In addition, the authors represented the analytical efficacy of Leeman labs multi-track profile ICP, and its rapid and accurate characters of simultaneous multi-element measurement.