Biomedical subjects

Takashi Furukawa

Publications and source records attributed to Takashi Furukawa.

5 recordsLinked to original sources

PubMed2006

A feasibility study: evaluation of radiofrequency ablation therapy to hepatocellular carcinoma using image registration of preoperative and postoperative CT.

RATIONALE AND OBJECTIVES: The therapeutic response to radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) often is evaluated by comparing pre- and post-RFA computed tomography (CT). However, judgment about whether an ablative margin, ie, 5-10 mm of normal hepatic tissue, is ensured sometimes is difficult. The aim of this study is to assess the feasibility of fusion images of pre- and post-RFA CT. MATERIALS AND METHODS: HCCs (n = 20) sized 13 +/- 5 mm (range, 4-23 mm) were included. For pre-RFA CT, the arterial phase of intravenous dynamic CT (n = 17), CT arterioportography (n = 2), and CT hepatic arteriography (n = 1) was used. Using automatic image registration software (n = 20) and a manual segmentation technique (n = 4), fusion images were created in combination with post-RFA CT (equilibrium phase of intravenous CT). RESULTS: Automatic image registration and manual segmentation technique took approximately 2-3 and 5 minutes, respectively. Total time required for the creation of fusion images was less than 10 minutes in all cases. Fusion images enabled easier understanding of the relationship between the tumor and ablation zone, helping judge whether an ablative margin was ensured. CONCLUSION: Fusion of pre- and post-RFA CT images is considered a feasible tool in the evaluation of RFA therapy for HCC.

Aged↗

PubMed2004

Prolonged circulation of menatetrenone by emulsions with hydrogenated castor oils in rats.

Previously, we reported that plasma half-lives of a drug incorporated in lipid emulsions prepared with soybean oil (SO), a long-chain triglyceride, and hydrogenated castor oils (HCOs) (SO/HCOs) were markedly longer, while those as SO/polyoxyethylene sorbitan esters (SO/PSs) were similar, compared to that as SO/egg yolk phosphatides (SO/EYP) [J. Pharm. Pharmacol. 54 (2002) 1357; J. Drug Target. 11 (2003) 37]. In the present study, lipid emulsions were prepared with Miglyol 812 (MO), a medium-chain triglyceride, and HCOs, and the kinetics of the incorporated drug, menatetrenone, were examined. The plasma half-lives and the liver uptake of menatetrenone as MO/polyoxyethylene-(10)-hydrogenated castor oils (MO/HCO10s) were similar to and larger than those as MO/EYP, respectively. On the other hand, the plasma half-lives and liver uptake of menatetrenone as MO/polyoxyethylene-(20)-hydrogenated castor oils (MO/HCO20s) or MO/polyoxyethylene-(60)-hydrogenated castor oils (MO/HCO60s) were markedly longer and lower than those as MO/EYP, respectively. The pretreatment of dextran sulfate 500,000, a reticuloendothelial system suppressor, raised the plasma concentration and inhibited liver uptake of menatetrenone as MO/HCO10, but not for MO/HCO20. These findings suggest that the minimum number of oxyethylene units within HCOs for the prolonged plasma circulation of menatetrenone was 20 for MO/HCOs, similarly to SO/HCOs.

Animals↗

PubMed2004

[Evaluation of the number of sampling step angles in SPECT Images: comparison between FBP and OS-EM reconstruction algorithms].

We compared filtered back projection (FBP) and ordered subset expectation maximization (OS-EM) reconstruction algorithms to examine the effects of sampling step angle on SPECT image reconstruction. Image sampling was compared between conditions of constant total sampling time (16 min) and constant sampling time (40 sec) for each step with angles of 3, 5, 7.5, and 10 degrees. Generally, OS-EM was superior to FBP in terms of image reconstruction. Changes in the sampling step angles did not significantly affect the quality of the reconstructed images with OS-EM insofar as acquisition counts were sufficient for evaluation. On the other hand, the quality of FBP images deteriorated with larger angles such as 7.5 and 10 degrees, and it was difficult to obtain stable results. In conclusion, OS-EM improves the quality of images required for examination.

Algorithms↗

PubMed2004

[Breast multidetector-row CT with histopathologic correlation].

PURPOSE: To evaluate the correlation between multidetector-row CT (MDCT) and histopathologic findings using the same MDCT image as the histopathologic cross-section. MATERIALS AND METHODS: MDCT with contrast enhancement was performed in 10 patients with breast cancers (8 invasive ductal carcinomas, one invasive lobular carcinoma, and one non-invasive ductal carcinoma). We tried to reconstruct multiplanar reconstructions (MPR) in the same plane as the histopathologic cross-section, and we evaluated the histopathologic findings of the false-positive lesions. RESULTS: In all cases, we obtained the same MDCT image as the histopathologic cross-section. There were 10 main lesions and 18 other lesions. In the other lesions, we found no false-negative lesions and 11 false-positive lesions. False-positive lesions included periductal fibrosis, cystic change, duct papillomatosis, sclerosing adenosis, fibroadenoma, and others. CONCLUSION: Using MDCT of the breast, it is possible to obtain good correlation between CT images and histopathologic findings. MDCT is thought to be useful in the evaluation CT findings on the basis of histopathologic evidence.

Adult↗

PubMed2002

Simultaneous preparation of four truncated analogues of discodermolide by fluorous mixture synthesis.

[structure: see text] Four truncated analogues of the natural product discodermolide were synthesized in a single synthetic sequence. Precursors bearing four different groups at C22, each with a unique fluorous p-methoxybenzyl substituent on the C17 hydroxy group, were mixed and taken through an nine-step sequence. Demixing by fluorous chromatography followed by deprotection and purification provided the individual analogues in 3-7% overall yields and with a savings of 24 synthetic steps. Fluorous mixture synthesis is recommended as a new technique to make multiple natural product analogues in a single multistep synthesis.

Alkanes↗