Thoracic Duct Lymphangiography via the Testicular Parenchyma in a Rabbit Model.

This study aimed to establish an animal model for thoracic duct lymphangiography using ethiodized oil. Thoracic duct lymphangiography was performed via the testes in 21 Japanese white rabbits. The testicular parenchyma was punctured by palpation using a 30-gauge, 0.5-inch needle. Ethiodized oil was injected at a rate of 11.41 mL/h until the testicular efferent lymphatic vessels were delineated and then at a rate of 2.85 mL/h until the entire thoracic duct was delineated. Thoracic duct delineation was 100% successful and showed good depiction based on visual scores. The mean ethiodized oil dose administered was 4.59 mL ± 1.41, and the mean time to visualize the entire thoracic duct was 43.7 minutes ± 14.1. The presented model may serve as a method for future preclinical investigation of the thoracic duct anatomy and for thoracic duct interventions.

Antitumor effect of miriplatin-lipiodol suspension/emulsion using a VX2 liver tumor model.

OBJECTIVE: To evaluate the antitumor effects of miriplatin-lipidol suspension and emulsion. MATERIALS AND METHODS: Fifty rabbits with VX2 liver tumors were randomly assigned to ten groups. Then, we prepared four types of mixtures: a suspension of lipiodol and miriplatin (ML), an emulsion of miriplatin dissolved with lipiodol and contrast medium (MLC) or saline (MLS), and saline alone (S). Ratios between lipiodol and contrast medium/saline volumes were 1:1/4, 1:1/2, 1:1, and 1:2 respectively. We used the same dose of miriplatin (2 mg/kg) and lipiodol (0.1 ml/kg) in each emulsion and suspension group. After intra-arterial infusion, the tumor growth rate was calculated, and sequential change of the plasma platinum concentration, the platinum concentration in the tumor and in surrounding normal liver tissue was also measured. RESULTS: Among the ten groups, the tumor growth rate was lower in MLC and MLS groups, and the difference between tumor treated with MLS emulsion (ratio 1:1/2) and ML suspension was significant (p = 0.02). The platinum concentration in the normal liver tissue was lower in MLS and MLC groups than in the ML group, and that in the tumor was higher in the MLS and MLC emulsion (ratio 1:1/2) groups. CONCLUSION: We suggest that miriplatin-lipiodol emulsion may be more effective than suspension.

Comparison of the anti-tumor effects of two platinum agents (miriplatin and fine-powder cisplatin).

PURPOSE: This study was designed to evaluate the anti-tumor effects of miriplatin-lipidol and fine-powder cisplatin-lipiodol suspensions. METHODS: Assessment of the cytotoxicity of two drugs was performed: a soluble derivative of miriplatin (DPC) and fine-powder cisplatin. We randomly divided 15 rabbits with transplanted VX2 liver tumors into three equal groups. They were infused via the proper hepatic artery with a miriplatin-lipiodol suspension (ML), a fine-powder cisplatin-lipiodol suspension (CL), or saline (control) and the tumor growth rate was determined on MR images acquired before and 7 days after treatment. The concentration of platinum (PCs) in blood was assayed immediately, and 10, 30, and 60 min, and 24 h and 7 days after drug administration. Its concentration in tumor and surrounding normal liver tissues was determined at 7 days postadministration. RESULTS: At high concentrations, fine-powder cisplatin exhibited stronger cytotoxicity than DPC. At low concentrations, both agents manifested weak cytotoxicity. While there was no difference between the tumor growth rate of the ML and the CL groups, the difference between the controls and ML- and CL-treated rabbits was significant. The blood PCs peaked at 10 min and then gradually decreased over time. On the other hand, no platinum was detected at any point after the administration of ML. There was no difference between the ML and CL groups in the PCs in tumor tissues; however, in normal hepatic tissue, the PCs were higher in ML- than CL-treated rabbits. CONCLUSIONS: We confirmed the anti-tumor effect of ML and CL. There was no significant difference between the anti-tumor effect of ML and CL at 7 days postadministration.

Complex comprised of dextran magnetite and conjugated cisplatin exhibiting selective hyperthermic and controlled-release potential.

We developed a dextran-magnetite conjugated cisplatin (DM-Cis) complex for use in thermal ablation and as a chemotherapeutic drug. To produce DM-Cis we reacted Cis with 1 mL DM (56 mg/mL iron). The temperature rise of DM-Cis was measured in vitro and in vivo under a portable induction-heating (IH) device. Platinum desorption from DM-Cis over 24 hours was measured in bovine serum. In in vivo accumulation and magnet and exothermic experiments we used four rat groups. In group 1 we delivered DM-Cis intraperitoneally (ip) and placed magnets subcutaneously (sc). In group 2 we injected saline (ip) and placed magnets (sc). In group 3 we injected DM-Cis (ip) and placed a sc incision (sham). The control (group 4) received an ip injection of saline. Rectus abdominis muscle tissue was stained with hematoxylin-eosin and iron-stained tissue areas (µm(2)) were calculated. The maximum platinum concentration in DM-Cis was approximately 105.6 µg/mL. Over 24 hours, 33.48% of platinum from DM-Cis was released. There was a significant difference (P < 0.05) in the iron-stained area between group 1 and the other groups. The temperature in muscle tissue registered a maximum of 56°C after about 4 min. DM-Cis may represent a magnetically-accumulated anticancer drug with hyperthermic effects.

[Plasma platinum concentration and anti-tumor effects after intra-arterial infusion of lipiodol-CDDP suspension evaluation with VX 2 rabbit liver cancer model and 7.0 Tesla MRI system].

To evaluate the usefulness of combination chemotherapy with cisplatin powder, which was newly designed for intra-arterial infusion (IA CALL) and lipiodol, for the VX 2 liver cancer model of the rabbit, sequential change of the plasma platinum concentration within the first 24 hours, as well as the tissue platinum concentration at 24 hours was measured after intra-arterial infusion of IA CALL. The infused materials were either IA CALL alone (C) or the combination of lipiodol+IA CALL (CL). In addition,the reduction rate of the VX 2 tumor was calculated among four therapeutic groups (C, CL, lipiodol alone (L), and saline alone (S)) after one week of intra-arterial infusion on the basis of 7.0 Tesla MR images. Total plasma platinum concentrations within the first 24 hours were kept low in group CL. No increase in the tissue platinum concentration in group CL was observed. On the other hand, the tumor reduction rate tended to be higher in group CL (group CL>group L=group C>group S). These results suggested that the intra-arterial infusion of IA CALL with lipiodol is more effective than that of IA CALL alone.