Gene therapy with B-cell maturation antigen/CD3 bispecific antibody encoding plasmid DNA for treating multiple myeloma.

The delivery of bispecific antibodies (BsAbs) targeting B-cell maturation antigen (BCMA) and CD3 using the gene therapy approach is a promising alternative for BsAb administration in patients with multiple myeloma (MM). In the present study, we evaluated the efficacy of this approach using a xenograft model. Tumour growth was significantly delayed in mice treated with single electroporation-enhanced intramuscular injection of plasmid DNA encoding BCMA/CD3 BsAb in contrast to the vehicle control-treated group. Limited toxicity was observed following treatment. This study demonstrates that the gene therapy-based approach for the delivery of BCMA/CD3 BsAb is effective and safe for the treatment of MM.

Bone marrow mesenchymal stem cells regulate the dysfunction of NK cells via the T cell immunoglobulin and ITIM domain in patients with myelodysplastic syndromes.

BACKGROUND: Myelodysplastic syndrome (MDS) is a clonal disease of hematopoietic cells, characterized by hematopoietic cell hematopoiesis and a high risk of transformation into acute myeloid leukemia (AML). Although the underlying mechanism is unclear, MDS is often associated with immune system disorders, especially cellular immune abnormalities. We analyzed the number of lymphocyte subsets by flow cytometry assay and explored the alteration of lymphocyte subsets in MDS. METHODS: Healthy controls, inpatients with primary MDS and patients with AML diagnosed from January 2017 to July 2021 were included. Flow cytometry assays were used to study lymphocyte subsets obtained from the bone marrow of the participants as well as changes in natural killer (NK) cell function. One-way analysis of variance and Student's t-test were used to analyze the data. RESULTS: We found a reduction in the number and function of NK cells in patients with MDS. By further measuring the activating and inhibitory receptors on the surface of NK cells, we found that the T cell immunoglobulin and ITIM domain (TIGIT) was the highest expressed marker on NK cells. Additionally, the expression of CD155, which is the ligand of TIGIT, was significantly higher than expressions of CD112 and CD113 on bone marrow mesenchymal stem cells (BMSCs). CONCLUSIONS: The co-culture results of BMSCs and NK cells demonstrated that BMSCs regulate NK cells through the TIGIT/CD155 interaction, indicating that NK cells play a vital role in MDS progression. BMSCs regulate the function of NK cells via TIGIT/CD155. Video Abstract.

Clinical significance of osteoblast precursors and osteoclast precursors in earlier diagnosis and monitoring of myeloma bone disease.

Bone disease is the most common complication of multiple myeloma (MM). In order to diagnose and monitor the bone damages earlier, we detected circulating osteoclast precursors (OCPs) and osteoblast precursors (OBPs) by flow cytometry, comparing with special biochemical markers, such as tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), carboxy-terminal cross-linking telopeptide of type I collagen (CTX), osteocalcin (OCN), and procollagen I amino-terminal propeptide (PINP). The results showed that the circulating OBPs in the newly diagnosed MM patients significantly decreased compared with the normal controls (7.14 vs 12.82 %, P = 0.045), while circulating OCPs in the newly diagnosed patients and remission patients were significantly increased than the normal controls (2.46 vs 0.17 %, P = 0.000; 1.87 vs 0.17 %, P = 0.000, respectively). According to X-ray, newly diagnosed patients were divided into stages A and B (without and with osteolytic lesions). Compared with the normal controls, the circulating OBPs in stages A and B reduced (12.82 vs 7.47 %, P = 0.041; 12.82 vs 7.14 %, P = 0.010, respectively), while the circulating OCPs elevated (0.17 vs 2.31 %, P=0.010; 0.17 % vs 2.71 %, P=0.001, respectively). The levels of TRACP-5b and CTX in the newly diagnosed patients were higher than the normal controls (P = 0.014, P = 0.037) and remission patients (P = 0.025, P = 0.003), and they were significantly higher in stage B than the normal controls (P = 0.015, P = 0.002). However, the PINP and OCN levels had no significant changes in different stages. In conclusion, abnormal circulating OBPs and OCPs were found earlier before X-ray in MM and still existed in remission patients, indicating that they may be novel predictive markers for early diagnosing and monitoring bone disease.

[Clinical significance of serum bone metabolic markers in diagnosis and monitoring of myeloma bone disease].

OBJECTIVE: To explore the significance of serum bone metabolic markers in the diagnosis and monitoring of multiple myeloma bone disease(MBD). METHODS: Thirty-six newly diagnosed multiple myeloma (MM) patients who were treated in Department of Hematology, Tianjin Medical University General Hospital from January 2013 to December 2014 were collected. Bone morbidity was graded into two stages according to the radiographic evaluation of the skeleton: stage A (n=12) included patients with no lytic lesions or with osteoporosis alone; stage B (n=24) included patients with osteolytic lesions and/or a pathological fracture. All the patients achieved partial or complete remission after treated with bortezomib + dexamethasone + zoledronic acid regimen. A total of 25 aged- and gender-matched healthy individuals were enrolled in this study as controls. The levels of serum tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), carboxy-terminal cross-linking telopeptide of type I collagen (CTX), osteocalcin (OCN), and procollagen I amino-terminal propeptide (PINP) were investigated by ELISA and electrochemiluminescence immunoassay (ECLIA). The differences of these bone metabolic markers before and after treatment, and at different stages of bone disease were observed. RESULTS: The value of TRACP-5b in the newly diagnosed MM was significantly higher than that in the healthy controls and after treatment(median 4.16 vs 2.63 U/L, P=0.014; 4.16 vs 2.61 U/L, P=0.037). Serum level of CTX in the newly diagnosed MM patients was significantly decreased after treatment (median: 0.26 vs 1.05 µg/L, P=0.003). The ratio of CTX/OCN and CTX/PINP decreased after treatment, but there were no significant differences (both P>0.05). The pretreatment level of serum TRACP-5b in stage B patients was higher than that of the healthy controls (median: 4.20 vs 2.63 U/L, P=0.015). The levels of serum CTX in stage A and stage B patients were both higher than that of the healthy controls (median: 1.16 vs 0.48 µg/L, P=0.002; 0.88 vs 0.48 µg/L, P=0.040). The levels of serum OCN and PINP were higher in stage A patients compared with stage B patients, but there were no significant differences (both P>0.05). The ratio of CTX/OCN and CTX/PINP of stage A and stage B patients all increased compared with those of the healthy controls, but there were no significant differences (all P>0.05). CONCLUSIONS: Bone damage of MM patients is improved after effective treatment, but bone imbalance still exists, indicating that the treatment of MBD is a long process. Abnormal serum levels of TRACP-5b and CTX are found before positive X-ray findings in MBD, suggesting that these biochemical markers could be used as indices for early diagnosis of MBD.

Relationship between abnormal osteoblasts and cellular immunity in multiple myeloma.

Bone destruction and abnormal immunity always occur in patients with multiple myeloma (MM), which manifested by impaired osteoblasts and immune system. In this study, we investigated the quantity and function of osteoblasts by co-culture, the status of cellular immunity by flow cytometry, and the relationship between them in MM patients. The results showed that the numbers and function of osteoblasts in MM patients were lower than those in normal controls. Bortezomib could increase the numbers, calcium depositions and the expression of Bone morphogenetic protein-2 (BMP-2) mRNA of osteoblasts from MM patients in vitro. The status of cellular immunity in MM patients was abnormal, including decreased ratio of CD4(+)/CD8(+), DC1/DC2 and Th1/Th2, and increased ratio of regulatory T cells. The ratio of CD4(+)/CD8(+)(r = 0.685) and CD4(+)CD25(+)/CD3(+)T(r = 0.568) were positively correlated with the quantity of osteoblasts (both P < 0.05). The serum interleukin-7(IL-7) level of MM patients was higher than that of normal controls (2.07 ± 0.71 vs. 1.62 ± 0.15 ng/L, P < 0.05), and was negatively correlated with the quantity of osteoblasts (r = -0.682, P < 0.01). Our data indicated that the proliferation and osteogenic potential of osteoblasts in MM patients were decreased which could be recovered by bortezomib in vitro. The down-regulation of cellular immunity was correlated with the quantity of osteoblasts.

Application of three-dimensional reconstruction and visible simulation technique in reoperation of hepatolithiasis.

BACKGROUND AND AIM: Hepatolithiasis often requires repeated operations in East Asia. This study aims to evaluate the clinical application of three-dimensional reconstruction and visible simulation techniques for repeated operation in patients with intrahepatic calculi. METHODS: A medical image processing system was used for modeling, segmentation, and three-dimensional reconstruction of intrahepatic stones in 20 patients, consisting of 7 males and 13 females who were subjected to repeated surgical treatment from May 2010 to November 2011. The three-dimensional models of the liver and bile ducts in a standard template library format were then processed by the FreeForm Modeling System. Accurate digital information about the bile duct system, lesions, calculi distribution, and surrounding organs obtained from all directions, multiple angles, and multistrata were used to decide the rational surgical modality. Virtual operations were then performed on the models with virtual surgical instruments in the FreeForm Modeling System. The results were used to guide and were compared with the real surgical procedures performed. RESULTS: The surgical outcomes of all patients in this study were satisfactory. Three-dimensionally reconstructed models provided clear and strong relief perception and a user-friendly interface. Visible simulation surgery performed based on three-dimensionally reconstructed models led to an optimal operation plan that had great resemblance to the actual surgeries for cases with intrahepatic stones. CONCLUSIONS: Three-dimensional reconstruction and visible simulation techniques had unique value in optimizing repeated operation plans and in guiding actual surgical procedures for patients with recurrent intrahepatic calculi.

Detection of myeloma cell-derived microvesicles: a tool to monitor multiple myeloma load.

The persistence of tumor load in multiple myeloma (MM) lead to relapse in patients achieving complete remission (CR). Appropriate and effective methods of myeloma tumor load monitoring are important for guiding clinical management. This study aimed to clarify the value of microvesicles in monitoring MM tumor load. Microvesicles in bone marrow and peripheral blood were isolated by differential ultracentrifugation and detected by flow cytometry. Western blotting was applied to assess myosin light chain phosphorylation levels. Flow cytometry to detect Ps+CD41a-, Ps+CD41a-CD138+, Ps+CD41a-BCMA+ microvesicles from bone marrow can be used to predict myeloma burden, furthermore, Ps+CD41a- microvesicles may as a potential index to MRD test. Mechanistically, the releasing of microvesicles from MM cell was regulated by Pim-2 Kinase via Phosphorylation of MLC-2 protein.

Roles of LINC01473 and CD74 in osteoblasts in multiple myeloma bone disease.

The suppression of osteoblast (OB) activity is partially responsible for multiple myeloma (MM) bone disease. Long non-coding RNAs (lncRNAs) play a vital role in bone formation and resorption. However, their functions in OBs from patients with MM have rarely been reported. Through high-throughput sequencing of OBs from patients with MM and healthy controls, we identified several lncRNAs and messenger RNAs (mRNAs) with different expression profile and validated them using quantitative real-time PCR. In total, 22 upregulated and 21 downregulated lncRNAs were found in OBs from patients with MM. Moreover, 18 upregulated protein-coding mRNAs were identified. The expression levels of LINC01473 and its associated co-expression mRNA, CD74, were higher in patients with MM than in healthy controls (p=0.047 and p=0.016, respectively). LINC01473 expression demonstrated a negative correlation with serum interleukin-2 and tumor necrosis factor α levels, whereas the expression of mRNA CD74 was positively associated with serum lactic dehydrogenase in patients with MM. Aberrant expression of lncRNAs and mRNAs was observed in OBs from patients with MM. This study identifies new promising targets for further research on imbalanced bone formation and resorption and MM immune escape.

Self-assembly of X-shaped antibody to combine the activity of IgG and IgA for enhanced tumor killing.

Rationale: IgA can induce activation of neutrophils which are the most abundant cell type in blood, but the development of IgA as therapeutic has been confounded by its short half-life and a weak ability to recruit NK cells as effector cells. Therefore, we generated an X-shaped antibody (X-body) based on the principle of molecular self-assembly that combines the activities of both IgG and IgA, which can effectively recruit and activate NK cells, macrophages, and neutrophils to kill tumor cells. Methods: X-body was generated by using a self-assembly strategy. The affinity of the X-body with the antigen and Fc receptors was tested by surface plasmon resonance. The shape of X-body was examined using negative staining transmission electron microscopy. The tumor cell killing activity of X-body was assessed in vitro and in multiple syngeneic mouse models. To explore the mechanism of X-body, tumor-infiltrating immune cells were analyzed by single-cell RNA-seq and flow cytometry. The dependence of neutrophil, macrophage, and NK cells for the X-body efficacy was confirmed by in vivo depletion of immune cell subsets. Results: The X-body versions of rituximab and trastuzumab combined the full spectrum activity of IgG and IgA and recruited NK cells, macrophages, and neutrophils as effector cells for eradication of tumor cells. Treatment with anti-hCD20 and anti-hHER2 X-bodies leads to a greater reduction in tumor burden in tumor-bearing mice compared with the IgA or IgG counterpart, and no obvious adverse effect is observed upon X-body treatment. Moreover, the X-body has a serum half-life and drug stability comparable to IgG. Conclusions: The X-body, as a myeloid-cell-centered therapeutic strategy, holds promise for the development of more effective cancer-targeting therapies than the current state of the art.

Complement C3a activates osteoclasts by regulating the PI3K/PDK1/SGK3 pathway in patients with multiple myeloma.

OBJECTIVE: Myeloma bone disease (MBD) is the most common complication of multiple myeloma (MM). Our previous study showed that the serum levels of C3/C4 in MM patients were significantly positively correlated with the severity of bone disease. However, the mechanism of C3a/C4a in osteoclasts MM patients remains unclear. METHODS: The formation and function of osteoclasts were analyzed after adding C3a/C4a in vitro. RNA-seq analysis was used to screen the potential pathways affecting osteoclasts, and the results were verified by Western blot, qRT-PCR, and pathway inhibitors. RESULTS: The osteoclast area per view induced by 1 µg/mL (mean ± SD: 50.828 ± 12.984%) and 10 µg/mL (53.663 ± 12.685%) of C3a was significantly increased compared to the control group (0 µg/mL) (34.635 ± 8.916%) (P < 0.001 and P < 0.001, respectively). The relative mRNA expressions of genes, OSCAR/TRAP/RANKL/cathepsin K, induced by 1 µg/mL (median: 5.041, 3.726, 1.638, and 4.752, respectively) and 10 µg/mL (median: 5.140, 3.702, 2.250, and 5.172, respectively) of C3a was significantly increased compared to the control group (median: 3.137, 2.004, 0.573, and 2.257, respectively) (1 µg/mL P = 0.001, P = 0.003, P < 0.001, and P = 0.008, respectively; 10 µg/mL: P < 0.001, P = 0.019, P < 0.001, and P = 0.002, respectively). The absorption areas of the osteoclast resorption pits per view induced by 1 µg/mL (mean ± SD: 51.464 ± 11.983%) and 10 µg/mL (50.219 ± 12.067%) of C3a was also significantly increased (33.845 ± 8.331%) (P < 0.001 and P < 0.001, respectively) compared to the control. There was no difference between the C4a and control groups. RNA-seq analysis showed that C3a promoted the proliferation of osteoclasts using the phosphoinositide 3-kinase (PI3K) signaling pathway. The relative expressions of PIK3CA/phosphoinositide dependent kinase-1 (PDK1)/serum and glucocorticoid inducible protein kinases (SGK3) genes and PI3K/PDK1/p-SGK3 protein in the C3a group were significantly higher than in the control group. The activation role of C3a in osteoclasts of MM patients was reduced by the SGK inhibitor (EMD638683). CONCLUSIONS: C3a activated osteoclasts by regulating the PI3K/PDK1/SGK3 pathways in MM patients, which was reduced using a SGK inhibitor. Overall, our results identified potential therapeutic targets and strategies for MBD patients.

Application of a medical image processing system in liver transplantation.

BACKGROUND: At present, imaging is used not only to show the form of images, but also to make three-dimensional (3D) reconstructions and visual simulations based on original data to guide clinical surgery. This study aimed to assess the use of a medical image-processing system in liver transplantation surgery. METHODS: The data of abdominal 64-slice spiral CT scan were collected from 200 healthy volunteers and 37 liver cancer patients in terms of hepatic arterial phase, portal phase, and hepatic venous phase. A 3D model of abdominal blood vessels including the abdominal aorta system, portal vein system, and inferior vena cava system was reconstructed by an abdominal image processing system to identify vascular variations. Then, a 3D model of the liver was reconstructed in terms of hepatic segmentation and liver volume was calculated. The FreeForm modeling system with a PHANTOM force feedback device was used to simulate the real liver transplantation environment, in which the total process of liver transplantation was completed. RESULTS: The reconstructed model of the abdominal blood vessels and the liver was clearly demonstrated to be three-dimensionally consistent with the anatomy of the liver, in which the variations of abdominal blood vessels were identified and liver segmentation was performed digitally. In the model, liver transplantation was simulated subsequently, and different modus operandi were selected successfully. CONCLUSION: The digitized medical image processing system may be valuable for liver transplantation.

CCN1 stimulated the osteoblasts via PTEN/AKT/GSK3ß/cyclinD1 signal pathway in Myeloma Bone Disease.

BACKGROUNDS: Myeloma-related bone disease (MBD) is a common complication of multiple myeloma (MM), which can both decrease life quality and influence the prognosis of the patients. We have found that CCN1 stimulated proliferation and differentiation of osteoblasts in MM in vitro and in vivo, while its mechanism still remains unknown. METHOD: Bone marrow mononuclear cells were collected from MM patients and differentiated into the osteoblasts. After co-culture with CCN1 in vitro, the intracellular signaling antibody array and western blot were performed to explore the signaling pathway. Furthermore, GSK3ß inhibitor TWS119 was used to check the pathway of CCN1 might have on osteoblasts in vitro. RESULTS: For the protein array kit, the expressions of GSK3ß, 4E-BP1, and PTEN are decreased in CCN1 group. For western blots, the CCN1 group also has lower expression comparing to the control group in PTEN (P = .031). Meanwhile p-AKT and cyclinD1 levels have increased in the CCN1 group (P = .002, P = .039). After adding TWS119 as another group, western blot was performed again to verify the pathway. For upstream proteins PTEN and p-AKT, TWS119 group has higher expression level compared to that in CCN1 group (P = .003, P = .001). And for downstream protein cyclinD1, TWS119 group also presented higher level than the control group (P = .02). CCN1 could have almost the same effect on GSK3ß as the specific inhibitor TWS119 had. CONCLUSIONS: CCN1 can stimulate osteoblasts through PTEN/AKT/GSK3ß/cyclinD1 pathway in MBD, which has the potential to be a novel therapy of MBD.

[Study on three dimensional reconstruction and simulation surgery of spleen].

OBJECTIVE: To study the three-dimensional (3D) reconstruction and the visualization simulation surgery of spleen based on the scanning data of 64-slice helical computed tomograph (CT). METHODS: The original data of 64-slice helical CT of spleen was collected, and then the CT image sequences were segmented and automatically extracted using auto-adapted region growth algorithm, and were conducted with the segmented images by adopt self-developed image processing software for 3D reconstruction. Finally, the 3D models were imported into FreeForm Modeling System for modifying and smooth. And the visualization simulation surgery was performed before splenectomy. RESULTS: It was fast and effective to utilize auto-adapted region growth algorithm to conduct spleen image program segmentation; the reconstructed models were seen clearly and could reappear the structure of the spleen and the important surrounding organs. The effect of the splenectomy simulation surgery was similar to the practical surgery. CONCLUSIONS: The research on 3D models of spleen and visualization simulation surgery of splenectomy could lead to clinical benefits. It maybe improve the surgical effect and decrease the surgical risk and reduce the complication demonstrating visualized operation before surgery.

CYR61/CCN1 stimulates proliferation and differentiation of osteoblasts in vitro and contributes to bone remodeling in vivo in myeloma bone disease.

Cysteine-rich 61 (CYR61/CCN1), a secreted protein in bone marrow (BM) microenvironment, has diverse effects on many cellular activities such as growth and differentiation. However, the effect of CCN1 on osteoblasts (OBs) in myeloma bone disease remains unclear. In our study, the level of CCN1 in multiple myeloma (MM) patients was detected by ELISA and RT-PCR. The proliferation and differentiation of OBs from MM patients were observed after stimulated by CCN1 in vitro. The myeloma cells transduced with CYR61 gene (RPMI­8226/CYR61) were injected in a mouse model to evaluate the efficacy of CCN1 in vivo and compare with zoledronic acid. The results showed that CYR61/CCN1 levels in BM supernatant and OBs both elevated significantly in all newly diagnosed MM patients, especially in patients without bone disease (P=0.001 and P<0.001). After 30 ng/l CCN1 stimulation for 24 h, the quantity and mineralization of OBs increased significantly in vitro (P=0.046 and 0.048). The transcription factors of Wnt pathway, runt-related transcription factor 2 (Runx2) and ß-catenin were upregulated in OBs after CCN1 stimulation (P=0.012 and 0.011). After injection of RPMI­8226 cells, bone lesions were observed obviously by microCT and histochemistry at 7 weeks. Radiographic analysis of the bones showed decreased resorption in CCN1 overexpression group and zoledronic acid group, while severe resorption in negative control. Furthermore, trabecular bone volume in CCN1 overexpression group (1.7539±0.16949) was significantly higher than zoledronic acid group (1.2839±0.077) (P=0.012). In conclusion, CCN1 can stimulate the proliferation and differentiation of OBs in vitro and contribute to bone remodeling in vivo in MBD.

A bio-inspired inner-motile photocatalyst film: a magnetically actuated artificial cilia photocatalyst.

A new type of inner-motile photocatalyst film is explored to enhance photocatalytic performance using magnetically actuated artificial cilia. The inner-motile photocatalyst film is capable of generating flow and mixing on the microscale because it produces a motion similar to that of natural cilia when it is subjected to a rotational magnetic field. Compared with traditional photocatalyst films, the inner-motile photocatalyst film exhibits the unique ability of microfluidic manipulation. It uses an impactful and self-contained design to accelerate interior mass transfer and desorption of degradation species. Moreover, the special cilia-like structures increase the surface area and light absorption. Consequently, the photocatalytic activity of the inner-motile photocatalyst film is dramatically improved to approximately 3.0 times that of the traditional planar film. The inner-motile photocatalyst film also exhibits high photocatalytic durability and can be reused several times with ease. Furthermore, this feasible yet versatile platform can be extended to other photocatalyst systems, such as TiO2, P25, ZnO, and Co3O4 systems, to improve their photocatalytic performance.

[Construction of digital three-dimensional models of renal stones and virtual surgery simulation].

OBJECTIVE: To construct three-dimensional (3D) models of renal stones and perform percutaneous nephrolithotomy (PCNL) virtual surgery simulation. Methods CT images were obtained from 8 patients with renal stones. Images segmentation and reconstruction were performed using MIMICS 10.0 software to construct the 3D model of the renal stones, which provided the anatomical relationships between the kidney and the adjacent organs. The optimal PCNL virtual surgery simulation for each individual case was performed using FreeForm Modeling System on the basis of the 3D model. RESULTS: Eight 3D models of renal stone were constructed. The 3D model of the renal stones represented the interrelationships of the stones, intrarenal vessel, and the collecting system with the adjacent anatomical structures. Individualized PCNL virtual surgery simulations including percutaneous puncture, dilatation and pneumatic lithotripsy were performed successfully in all the 8 3D models. CONCLUSION: Digital 3D model of renal stone provides the reliable and comprehensive imaging information for surgical design, and PCNL virtual surgery simulation has important clinical significance to improve the stone clearance rate and reduce the surgical complications.

[Virtual surgery of cholecystotomy for calculus removal and cholecystectomy in patients with cholecystolithiasis].

OBJECTIVE: To study the two-dimensional (2D) image segmentation, three-dimensional (3D) reconstruction and virtual surgery of cholecystectomy based on the 2D image data of the liver, biliary track and cholecystolithiasis obtained by 64-slice spiral CT. METHODS: The image data of the liver, biliary track and cholecystolithiasis were obtained by 64-slice spiral CT scanning. Segmentation and automatic extraction of the images were performed using auto-adapting region growing algorithm. 3D reconstruction of the segmented data was carried out using MIMICS10.0 and self-designed software, and the data of the 3D model of the liver with the billiary tract were imported into FreeForm Modeling System for registration and smoothing. Virtual surgery of cholecystotomy for calculus removal and cholecystectomy were performed with Phantom. RESULTS: The auto-adapting region growing algorithm allowed rapid image segmentation, and the 3D model of the liver based on the segmentation data clearly displayed vivid 3D structures of the liver. Virtual operations of cholecystectomy could be performed in the FreeForm Modeling System. CONCLUSION: The algorithm we proposed can correctly and rapidly complete image segmentation and 3D reconstruction of cholecystolithiasis from the data 64-slice spiral CT, and allows virtual operations on the gallbladder.