Negative feedback regulation of activated macrophages via Fas-mediated apoptosis.

Apoptosis is a critical event for eliminating activated macrophages. Here we show that Fas-mediated apoptosis may participate in the mechanism of negative feedback regulation of activated macrophages. Cytokine-activated macrophages released high levels of nitric oxide (NO) that induced apoptosis in macrophages themselves. This NO-induced macrophage apoptosis was inhibited by a Fas-Fc chimeric molecule that binds to Fas ligand (FasL) and prevents its interaction with endogenous cell surface Fas. High levels of NO stimulated the release of the soluble form of FasL that was inhibited by a matrix metalloproteinase inhibitor KB-8301. High levels of NO also upregulated the expression of Fas mRNA in macrophages. In addition, macrophages isolated from Fas-lacking mice were resistant to NO-induced apoptosis. Finally, inhibition of apoptosis by a caspase inhibitor augmented peroxide production from activated macrophages. These findings suggest that high levels of NO released from activated macrophages may promote the Fas-mediated macrophage apoptosis that may be a negative feedback mechanism for elimination and the downregulation of activated macrophages in the vessel wall.

[Embolization of varicocele with ethanol].

Embolization with ethanol was performed in 40 varicocele patients to prevent recurrence due to collateral formation. A prescribed amount of ethanol (0.5-4 ml) was injected slowly into the testicular vein with the catheter tip as close as possible to the inguinal region. Embolization with stainless steel coils was also performed in 15 of the 40 patients. Immediately after embolization, three varicoceles were reduced in size, and 37 disappeared. Recurrence was recognized in only two patients. These patients were embolized at a proximal site above lumbar vertebra IV. Spermatic data have improved for 13 patients but not for one azoospermatic patient. Serious complications were recognized in only one patient, who received an injection of 15 ml ethanol in one dose. Therefore, we conclude that embolization with ethanol is an useful treatment for varicocele.

[Intermittent intraarterial infusion chemotherapy using a subcutaneously implanted reservoir in patients with hepatoma].

Hepatocellular carcinomas that should not be treated with transarterial embolization (TAE) were treated with intermittent intraarterial infusion chemotherapy using a subcutaneously implanted reservoir. Among 37 patients, in whom objective evaluation of the initial response was possible, 3 cases of CR, 12 of PR, 10 of NC and 12 of PD were obtained. The response rate was 40.5%. Culminate 1 year survival rates were 80.0% for responders (CR + PR), 4.5% for non-responders (NC + PD) and 35.1% as an average for all patients. The survival in responder patients was better than in non-responders (p < 0.001). To determine the role of this therapy we divided the cases into two groups by anamnesis of TAE and investigated the initial response and prognosis based on the grade of portal vein invasion in each group. In one group of 18 patients, who had not been treated with TAE, there were no relationships between the grade of portal vein invasion and the initial response and between the grade of portal vein invasion and the prognosis. In this group the initial response was better in patients whose one shot infusion chemotherapy immediately before intermittent intraarterial infusion chemotherapy had been effective than in the others. In the other group of 19 patients, who had been treated with TAE, the initial response and prognosis were better in patients with lower grades of portal vein invasion (Vp0-2) than in those with the highest grade (Vp3).

[MR-angiography of veins in the lower extremities].

Phase contrast MR-angiography (MRA) of veins in the lower extremities was performed in 10 healthy volunteers and 2 patients with deep vein thrombosis of the lower extremities. In all volunteers, MRA demonstrated bilateral large saphenous veins, femoral veins and popliteal veins. Deep veins in the leg were visualized in only 3 out of 20 legs examined, but with compression of the thigh they were visualized in 4 out of 7 legs subjected to compression. In patients with deep vein thrombosis, obstruction of the femoral veins and development of the collateral veins were clearly visualized. It is concluded that MRA may be a valuable technic for the evaluation of the veins patency in the lower extremities.

[MR angiography of the forearm--visualization of the internal dialysis shunt].

Phase contrast MR angiography (MRA) of the forearm was performed in 10 healthy volunteers and 3 patients with chronic renal failure. In all volunteers, MRA demonstrated two arteries (radial artery and ulnar artery) and several cutaneous veins. In patients with chronic renal failure, internal dialysis shunts were clearly visualized and the stenoses of the shunts which were confirmed by later DSA were also well defined. It is concluded that MRA may be a valuable technic in the evaluation of internal dialysis shunts.

[Studies on biodegradable microcapsules of anticancer drugs].

We made biodegradable microcapsules for the controlled release of an anticancer drug. The spherical capsules were designed to be infused repeatedly through an implanted angiographic catheter. The microcapsules were made by the Wurster method, and consisted of a core consisting of lactose and a shell consisting of lecithin, cholesterol, stearic acid, and polyvinylpyrrolidone. The capsules with diameters of 50 to 200 microns could be infused through a catheter. In blood plasma, the capsules absorbed water and disintegrated in 20-30 min. The amount of drug released from the microcapsules in a test of dissolution in a column could be controlled by changes in the thickness of the shell. These capsules will now be tested in rabbits with experimental tumors.

Characterization of the subunit particles of feline calicivirus.

In the culture fluid from cells infected with feline calicivirus (FCV) F4 strain, the infectious and smaller non-infectious subunit particles were detected by complement fixation (CF) test after sucrose gradient centrifugation. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analyses confirmed the existence of the subunit particles of FCV, and showed that the infectious and subunit particles were mainly composed of 65K capsid protein. The subunit particles were further purified by ion-exchange chromatography and sucrose gradient centrifugation. The purified subunit and infectious particles had the same neutralizing epitope on 65K protein detected by immunoblot analysis with a neutralizing monoclonal antibody. Antigenic comparison between the infectious and subunit particles by the CF tests using an antiserum against heterologous strain of FCV F14 indicated that the subunit particles might have more highly conserved antigens of FCV than the infectious particles.

[Multifocal fatty infiltration of the liver: report of six cases].

Images of computed tomography (CT), ultrasonography (US), angiography and radionuclide imaging were analyzed in six cases of multifocal fatty infiltration of the liver. Histologic confirmation of fatty infiltration was obtained in one patient by percutaneous biopsy. In the remaining patients, presumptive confirmation of the diagnosis was based on the CT number in one patient and partial or complete resolution of the lesions on repeat CT scans or US in 4 patients. CT and US were performed in all six patients. CT scans demonstrated multiple round areas of low attenuation within both lobes of the liver in all cases. US studies showed hyperechoic foci in three cases and diffuse inhomogeneous hyperechogenicity in three cases. Hepatic arteriograms in five cases and liver scintigrams in four cases showed no evidence of space-occupying lesions. In all cases, the lesions completely or partially resolved in follow-up CT and US, and in four cases the lesions disappeared within two months, so follow-up examinations within about 2 months are necessary to differentiate these from liver neoplasms.

Preparation and characterization of neutralizing monoclonal antibodies to feline calicivirus.

Fourteen neutralizing monoclonal antibodies (N-MoAbs) were prepared against the F4 strain of feline calicivirus (FCV), the prototype strain of FCV in Japan, and examined for their ability to neutralize FCV isolates. Neutralization-resistant variants of the F4 strain were selected under the presence of 4 individual N-MoAbs in cell culture systems and used in cross-neutralization tests and enzyme-linked immunosorbent assay with all of the 14 N-MoAbs. The results revealed the identification of at least two antigenic determinants on FCV F4: one being more broadly conserved among FCV isolates than the other. Usefulness of antigenic variants resistant to N-MoAbs for analysis of neutralization determinants on FCV was also demonstrated.

[Selective segmental sclerotherapy of the liver by transportal ethanol injection--a complete remission case of hepatocellular carcinoma].

Selective segmental sclerotherapy of the liver by transportal ethanol injection (SSS) was devised and evaluated in a case of hepatocellular carcinoma. The patient was a 72-year-old man suffering from unresectable hepatoma. Injected ethanol with an amount of 20 ml into the portal branch under occluding the portal flow by balloon catheter produced complete necrosis of the liver proportional to the injected liver segment including the tumor on CT. Because of ethanol perfusion into sinusoid level by wedge injection, its cytotoxicity maybe affected liver cells directly. In this case, there has been no evidence of inadvertent liver damage and a significant rise in the blood ethanol level. The present technique of SSS in this clinical case and our past animal experience seemed to yield the same condition as resection without surgical disadvantages and be apparently a safe method, which is suggested for clinical use for several hepatic tumors.

[Experimental and clinical studies on degradable starch microspheres (DSM) in the treatment of hepatic neoplasms].

To evaluate the effect of hepatic arterial chemotherapy combined with DSM, experimental and clinical studies were performed. Experimental study: Hemodynamic and histological changes induced by intra-arterial administration of DSM were investigated in the kidneys of rabbits. The degree of blockade of arterial blood flow was correlated with the dosage of DSM, and estimated by the angiographic change. Histological changes also depended on the dosage of DSM. Although administration of less than 6 mg DSM induced little or no histological changes, more than 15 mg of DSM induced extensive necrosis of renal tubules. Clinical study: The hepatic arterial chemotherapy combined with DSM was performed in 63 patients (hepatomas in 45 and metastatic tumors in 18). Fourteen patients (30%) showed partial or complete response. Patients with a higher degree of blockade of arterial blood flow tended to have a better response. Analysis of CT images suggested that DSM not only enhance the chemotherapeutic agents but also the ischemic effect. In conclusion, degree of blockade of arterial blood flow is controlled by the change in DSM dosage, and DSM administration combined with chemotherapeutic agents may have the potential to improve the therapeutic effect.