[Quality control (QC) of CT on rail system (FOCAL Unit) with a micro-multi leaf collimator (mMLC) using new GafChromic film for stereotactic radiotherapy].

PURPOSE: Recent years, CT on rail system was reported to be useful as a tool for image-guided radiotherapy (IGRT). This system was clinically developed with the aim of stereotactic irradiation (STI) for brain, lung, liver, prostate and other sites. Quality assurance and quality control (QC) is an important issue in CT on rail system to assure geometric accuracies. The purpose of this study is to estimate the geometric accuracies of our CT on rail system using a detachable micro-multi leaf collimator (mMLC) with new type radiochromic films. Carrying out our original QC program, translational errors, setup reproducibility, beam misalignment and beam characteristics were evaluated. METHODS AND MATERIALS: We have studied with CT on rail system (FOCAL unit, Toshiba Medical systems, Tokyo, Japan) and mMLC unit (Accuknife, Direx Inc., Tokyo, Japan). We have developed original alignment phantom and small steel markers (2 mm phi) were implanted on its surface at certain intervals. Firstly, we have evaluated the accuracy of self-moving CT gantry and CT resolutions for cranio-caudal directions by changing slice thickness. And then using the phantom, we have measured the accuracy and reproducibility of geometric isocenter of the linac side and the CT gantry side by scanning the phantom. We have also measured the geometric changes of the common treatment couch by weight-loaded test (up to 135 kgw). To estimate dosimetric and geometric accuracies with the mMLC unit, the misalignment of the beam axes (gantry, collimator and couch rotation axis), mMLC leaf positions, and dose distributions for the verification plan were measured with new type GafChromic films (GafChromic-RTQA, ISP Inc., USA) and cylindrical phantom. The dose characteristics of the GafChromic film were also evaluated. RESULTS: The reproducibility of the self-moving CT gantry have a good agreement within 1 mm. Weight-load test have shown a good reliability within 2 mm at the common treatment couch. The translational precision of the common treatment couch was 0.0 +/- 0.1 mm at linac side and -0.2 +/- 0.5 mm at CT gantry side. The misalignments of beam axes have been kept within 0.4 mm at maximum. Gap test have shown the accuracies of the mMLC leaf positions, which is needed to keep within 1 mm by a routine calibration. CONCLUSIONS: To practice quality control program for the FOCAL unit and the mMLC unit is essential for a regular interval to reduce systematic errors. New type radiochromic film would be useful for a verification tool as alternative to conventional film.

[A case of advanced hepatocellular carcinoma with portal invasion resected after treatment by continuous intra-arterial chemotherapy with cisplatin and 5-fluorouracil].

A 67-year-old male diagnosed as having inoperable advanced hepatocellular carcinoma with portal invasion was able to undergo resection after continuous intra-arterial chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP). These were continuously administered for 24 hours at doses of 5-FU of 250 mg and CDDP of 5 mg/day, from day 1 to day 5 in a week, repeated 6 times. In additions to the reductions of the levels of AFP and PIVKA-II from 212.6 ng/ml and 16,100 mAU/ml to 11.8 ng/ml and 12 mAU/ml, respectively, the volume of the tumor and the portal invasion were diminished remarkably. As a result, a left extended hepatectomy could be performed. No sign of recurrence was seen during 16 months of follow-up after the operation. Given the above results, continuous intra-arterial chemotherapy with 5-FU and CDDP therapy may be effective for patients with hepatocellular carcinoma.

Choledochal stenosis and lithiasis caused by penetration and migration of surgical metal clips.

A 71-year-old woman, who had undergone laparoscopic cholecystectomy 1 year previously at our hospital, presented with abdominal pain, high fever, and jaundice. She was diagnosed with choledochal stenosis caused by migration of the clips that were used at the previous operation. At reoperation, the common bile duct was successfully dissected, including the stenotic site, where a metal clip was found to be penetrating the duct wall. The stenotic site was sufficiently resected, when a black-brown gallstone was found proximally to the stenosis. Interestingly, the stone was found to contain two metal clips, which were considered to have migrated into the bile duct and to have acted as a nidus for stone formation. The common bile duct was reconstructed by direct end-to-end anastomosis. Surgeons must exercise caution in the use of metal clips, keeping in mind the potential risk of clip migration.

Changes in extracellular matrix components after excimer laser photoablation in rat cornea.

PURPOSE: To learn more about corneal wound healing after excimer laser photoablation. METHODS: Observations were made on the chronological changes in type I collagen, fibronectin, laminin, and type IV collagen after excimer ablation of rat cornea. Immunohistochemical techniques were used. RESULTS: There was no obvious change in the localization of type I collagen in the ablated area, but the localization of fibronectin, laminin, and type IV collagen changed remarkably. One day after ablation, immunofluorescent staining for fibronectin increased on the ablated surface. Subsequently, the fluorescence of fibronectin, laminin, and type IV collagen increased remarkably; in particular, the localization of these extracellular matrix proteins was sustained in the shallow layer of the stroma until about 24 weeks after ablation. Hematoxylin-eosin staining indicated that keratocytes temporarily disappeared 1 day after ablation, and activated keratocytes then migrated to the ablated areas. CONCLUSIONS: These results suggest that activated keratocytes might be synthesizing the extracellular matrix components. Therefore sustained responses of keratocytes may be induced by excimer laser photoablation.

2'-Pyrene modified oligonucleotide provides a highly sensitive fluorescent probe of RNA.

Oligonucleotide 9mers containing 2'-O-(1-pyrenylmethyl)uridine [U(pyr)] at the center position were synthesized by using a protected U(pyr) phosphoramidite. The UV melting behaviors indicate that the pyrene-modified oligonucleotides can bind to both their complementary DNA and RNA in aqueous solution. When compared with the unmodified oligonucleotides, the pyrene-modified oligonucleotides showed higher affinity for DNA while exhibiting lower affinity for RNA. The pyrene-modified oligonucleotides in diluted solution exhibited fluorescence typical of pyrene monomer emission [lambdamax 378 (band I) and 391 nm (band III)]. When these oligomers bound to DNA, the fluorescence intensity ratio of band III/band I was increased. With this fluorescence change, a new broad emission (lambdamax 450 nm) due to exciplex between the pyrene and an adjacent nucleobase appeared. In contrast, addition of RNA to the pyrene oligonucleotides resulted in enhancement of the pyrene monomer emission with decrease in the fluorescence band ratio. The extent of the emission enhancement was found to be highly dependent on the nucleobase adjacent to the U(pyr) in the pyrene oligomers. The pyrene oligonucleotide containing dC at the 3'-site of the modification showed remarkable increase (approximately 250 times) in fluorescence (375 nm) upon binding to complementary RNA. The present findings would open the way to the design of a highly sensitive fluorescent probe of RNA.

[Changes in extracellular matrix components after excimer laser photoablation in rat cornea].

To understand the response of rat corneal wound healing after excimer laser photoablation, we observed the chronological changes in the localization of type I collagen, fibronectin, laminin, and type IV collagen after photoablation of the rat cornea. With immunofluoresence techniques, no obvious changes in the localization of type I collagen could be observed in the area of the wound. However, the localization of fibronectin, laminin, and type IV collagen was dramatically changed. One day after ablation, the fluorescein intensity of fibronectin increased at the denuded surface. After that, fibronectin, laminin, and type IV collagen were dramatically increased, especially in the shallow layer of the stroma, until about 7 days after ablation. In hematoxylin-eosin staining, keratocytes disappeared transiently from the area of the wound 1 day after ablation and then activated keratocytes migrated to the area. These results suggested that activated keratocytes might actively synthesize the extracellular matrix components. Therefore, sustained responses of keratocytes may be induced by excimer laser photoablation.

Preventive effect of pirfenidone against experimental sclerosing peritonitis in rats.

We investigated the preventive effect of pirfenidone (PFD), a newly developed anti-fibrotic agent, on experimental sclerosing peritonitis (sp) which we had established in rats. Male Wistar rats (150-250 g) were divided into the following two groups; 7 rats were treated with daily intraperitoneal (i.p.) injection of 0.1% chlorhexidine gluconate (CH) and 15% ethanol solved in 2 ml of saline for 26 days as a control of SP model (CH group) and 6 rats were treated daily with peroral (p.o.) administration of 350 mg/kg of PFD in addition to the daily i.p. injection of aforementioned CH-ethanol-saline solution for 26 days (CH + PFD group). Macroscopic intraperitoneal changes and histological fibrotic changes were graded by scoring in a blind manner. Actual subserosal thickness was measured by observation under light microscope. Body weight gain was significantly greater in CH + PFD group than in CH group (P < 0.05). Macroscopic intraperitoneal adhesion changes in CH + PFD group were significantly fewer than in CH group (P < 0.05). Fibrotic changes were fewer and subserosal thickness in liver and intestine were smaller in CH + PFD group with statistical significance (p < 0.1). We concluded that PFD markedly inhibited or prevented fibrotic changes in the experimental sclerosing peritonitis induced by CH.

[Acute and chronic effect of moxisylyte hydrochloride on the retinal circulation in diabetes mellitus].

The effect of moxisylyte hydrochloride, a new type alpha 1-blocking vasodilator, on the retinal circulation was investigated in 14 diabetics, using the video-densitometric image analysis of fluorescein angiography. The build-up time (BT) and the mean circulation time (MCT) were compared before and after oral administration of moxisylyte. The BT one hour after oral administration of 30 mg moxisylyte was significantly shorter than that before therapy (artery; before 5.2 +/- 1.5 vs after 4.6 +/- 1.0 sec; p = 0.0001, vein; before 6.9 +/- 1.3 vs 6.3 +/- 1.1 sec; p = 0.0005). The MCT two weeks after oral administration of 90 mg per day moxisylyte was significantly shortened (before 3.6 +/- 2.3 vs after 2.6 +/- 1.4 sec; p = 0.0180). These results suggested that oral moxisylyte improved the retinal circulation and might support the concept that moxisylyte hydrochloride has clinical usefulness in patients with diabetes mellitus.

Successful use of the centrifugal ventricular assist device for postcardiotomy cardiogenic shock.

A centrifugal pump was successfully used as a left ventricular assist device (LVAD) in a 54-year-old female who developed cardiogenic shock following open heart surgery. Cardiac index prior to the LVAD support was 1.4 l/min/m2 and increased to 3.0 l/min/m2 at removal of the device, which assisted for 88h. She resumed her daily activity 10 months after the operation and is in New York Heart Association functional class I.

Direct determination of the blood concentration of halogenated anesthetic agents by gas chromatography.

The direct determination by gas chromatography of blood levels of anesthetic agents has been difficult because of the water content of blood. In the present study, the method of Yokota et al. (1967) was modified by improving the packing materials of the column, the blood sample vaporizer and the flow-path during analysis. As a result, accurate and reproducible determination of halothane, enflurane and isoflurane dissolved in blood was achieved. With this system, blood in which halothane, enflurane and isoflurane had been dissolved could be analyzed without changing the column between samples. Moreover, each sample was prepared in less than 10 min, and more than 100 consecutive determinations could be made with excellent reproducibility. The coefficient of variation was less than 3.8%.

[Analysis of the right ventricular function by simulation (author's transl)].

In the previous experiments it was reported that either the interventricular septum of the free wall of the right ventricle was replaceable with a non-contractile prosthesis. It was also reported that a new chamber constructed on the epicardium had capability of producing a pulsatile pressure. This study was to determine contribution of the septum and the free wall on performance of the right ventricle by using a simulator. Left-ward shift of the interventricular groove was not found along the basal half of the long axis and was limited only along the apical half. Bulging of the septum toward the right ventricular cavity did not occur at all, but on contrary the septum moved toward left, denying contribution of the septal movement to pump action of the right ventricle.