Efficacy of immunoliposomes on cancer models in a cell-surface-antigen-density-dependent manner.

We have recently established a cancer-reactive human monoclonal antibody, GAH, with a positive ratio of over 90% against stomach cancer. GAH was formulated as polyethyleneglycol (PEG)-modified immunoliposomal doxorubicin (DXR) (ILD) and its efficacy was examined against gastrointestinal human cancers. In in vitro studies, a comparison of ILD with PEG-modified liposomal DXR (LD) demonstrated that ILD had dose-dependent cytotoxicity for GAH-reactive B37 cancer cells, but not LD. In concordance with this result, microscopic observations showed that ILD was bound to and GAH-dependently internalised by B37 cells. In in vivo studies, ILD exhibited significantly greater antitumour activity on cancer xenograft models than LD or free DXR. The relation between efficacy and antigen density was examined on 10 xenograft models bearing cancer cells with varying GAH reactivity. Immunoliposomal doxorubicin therapeutic activity correlated with the antigen density, with a minimum number being required. Also, ILD revealed strong antitumour activity on cancers with low sensitivity to DXR or LD, suggesting that ILD overcame the DXR resistance of antigen-positive cancer cells. Thus, these results show that GAH endows liposomes with targeting activity, resulting in strong efficacy against gastrointestinal cancers.

[Surgery using master-slave manipulators and telementoring].

Master-slave manipulators enhance surgeons' dexterity and improve the precision of surgical techniques by filtering out surgeons' tremors and scaling the movements of surgical instruments. Among clinically available master-slave manipulators, the epoch-making system called "da Vinci" developed by Intuitive Surgical Inc. (Mountain View, CA, USA), equipped with 2 articulated joints at the tip of the surgical instruments allowing 7 degrees of freedom, mimics the movements of surgeons' wrists and fingers in the abdominal or thoracic cavity. Today advanced telecommunications technology provides us excellent motion images using only 3-ISDN telephone lines. Experienced surgeons at primary surgical sites have been able to perform complex procedures successfully by consulting specialists at remote sites. Because telecommunications costs have become lower each year, telementoring will be come a routine surgical practice in the near future. The usefulness of surgical telementoring has been greatly enhanced by the development of a technique to illustrate on video images from two directions. Moreover, remote advisory surgeons will be able to provide the optimal operative field to operating surgeons using robotic camera holders with voice-recognition systems. In the near future, when master-slave manipulators will also be coupled with telementoring systems, remote experts could actually perform complex surgical procedures.

[A new video-assisted thoracoscopic surgical interruption of patent ductus arteriosus].

A new video-assisted thoracoscopic surgery was applied to patients with patent ductus arteriosus (PDA). After the ductus was carefully dissected and exposed, two or one titanium clips which were 11 mm in length were used to interrupt the ductus completely. Eight patients with PDA were successfully treated by the new technique between July 1992 and September 1993, which was the first successful series in Japan. Mean age was 4.3 years (range 1.7 approximately 6.7 years) and mean weight was 15.6 kg (range 10.0 approximately 24.0 kg). All patients had immediate complete PDA closure after the procedure which was proved to be successful by an esophageal stethoscope and color doppler echocardiogram. One patient had mild left recurrent laryngeal nerve dysfunction which was completely cured on 7th postoperative day. There were no other complications and the usual hospital stay was 4 or 5 days. No residual PDA shunt in all cases was revealed by color doppler echocardiogram during follow-up periods (range 3 approximately 12 months). The advantages of thoracoscopic surgery for PDA are: less postoperative pain and discomfort, early recovery and short hospital stay, and cosmetic preservation. Availability of smaller sized surgical instruments should allow this technique indicated for smaller children and premature infants.

An innovative thoracoscopic surgery for patent ductus arteriosus: a Japanese first case report.

A 5-year-old girl with patent ductus arteriosus (PDA) was successfully treated by thoracoscopic surgery, which was the first successful case in Japan. The operation was carried out under general anesthesia with the usual endotracheal intubation. Short trocars were inserted through the left intercostal spaces to introduce a flexible video thoracoscope and adequate surgical instruments. After the ductus was carefully dissected and exposed, two titanium clips, 11 mm in length, were applied to interrupt the ductus completely. The continuous heart murmur of PDA disappeared, as confirmed by an esophageal stethoscope. Postoperative course was uneventful and the patient was discharged on the 6 postoperative day. Eighteen months after surgery, no residual PDA shunt was revealed by doppler echocardiogram. The advantages of thoracoscopic surgery for PDA are less postoperative pain and discomfort, early recovery and short hospital stay, and cosmetic preservation. Availability of smaller sized surgical instruments should allow smaller children or newborns with PDA to be treated with this method.

[An innovative thoracoscopic surgery for patient ductus arteriosus--a Japanese first case report].

A five-year-old girl with patent ductus arteriosus (PDA) was successfully treated by thoracoscopic surgery, which was the first successful case in Japan. The operation was carried out under general anesthesia with usual endotracheal intubation. Short trocars were inserted through the left intercostal spaces to introduce a flexible video thoracoscope and adequate surgical instruments. After the ductus was carefully dissected and exposed, two titanium clips which were 11 mm in length were applied to interrupt the ductus completely. The continuous heart murmur of PDA was confirmed to disappear by an esophageal stethoscope. Postoperative course was uneventful and the patient was discharged on 6 postoperative day. No residual PDA shunt was revealed by doppler echocardiogram 8 months after surgery. The advantages of thoracoscopic surgery for PDA are: less postoperative pain and discomfort, early recovery and short hospital stay, and cosmetic preservation. Availability of smaller sized surgical instruments should allow this method indicated for smaller children or newborns with PDA.

Comparative analysis of p53 and c-myc expression and cell proliferation in human hepatocellular carcinomas--an enhanced immunohistochemical approach.

Expression of p53 and c-myc was investigated and compared with cell proliferative activity in a series of 40 hepatocellular carcinomas (HCC), by means of enhanced immunohistochemistry. p53 expression was demonstrated in 5 out of 40 HCC (12.5%) with the incidence increasing in 5 out of 40 HCC (12.5%) with the incidence increasing in proportion to the histological grading of malignancy: thus, 0% of well-differentiated, 6.9% of moderately differentiated and 33.3% of poorly differentiated lesions were positive. The proliferating-cell nuclear antigen (PCNA) labeling index also showed a statistically significant increase with this grading. Distribution patterns of PCNA-positive cell were divided into four types: scatter, marginal, mosaic and diffuse. Four HCC cases, predominantly of the poorly differentiated type, exhibited the diffuse pattern. Generally, p53 overexpression corresponded well with PCNA positivity. In contrast, there was no correlation between c-myc overexpression, found in 19 out of 40 HCC (47.5%), and histological grading of HCC or PCNA labeling index. The distribution pattern of c-myc-positive HCC cells was also different from that of PCNA and p53. Our results suggest that p53 overexpression closely relates to proliferation of HCC cells. Furthermore, there may be a consistent difference in regulatory mechanisms between p53 and c-myc expression in multistep hepatocarcinogenesis.

[Cancer chemotherapy for recurrence of breast cancer employing implantable system via right internal mammary vein].

Chemotherapy using anti-cancer drugs for patients with recurrent breast cancer generally requires a comparatively long duration. The long-term securing of a vein for distal administration, however, is difficult because of stenosis resulting from chemical thrombophlebitis. In an effort to develop new administration routes for anti-cancer drugs, central venous access from different sites has been tried, but problems such as thrombus, stenosis and infection have resulted owing to catheter problems. In the hopes of shortening the distance of an indwelling in a central vein, we recently tried implanting of an indwelling reservoir for intravenous infusion via the right internal mammary vein according to the anatomical characteristics for administering anti-cancer drugs at a high dose. During administration of anti-cancer drugs, we have observed no trouble. For the improved quality of life of cancer patients, the route employed here can be ideal for the administration of anti-cancer drugs.

[Clinical reevaluation of continuous intravenous infusion of 5-fluorouracil--plasma concentrations and clinical dose by continuous intravenous and 60-min infusions].

Daily and intermittent continuous intravenous infusions [by gravity drip, (IVG) or infusion pump, (IVP)] and intermittent short-time intravenous drip infusion of 5-FU were carried out on advanced cancer patients. The MTD and dose-limiting toxicity were investigated in relation to the plasma concentrations of 5-FU determined by HPLC. Responses in eleven patients receiving IVG administration daily at 8-21 mg/kg/day were NC, but those given 5-FU alone showed no adverse reactions. Plasma concentrations were too low to be determined. In 9 patients receiving IVG or IVP administration weekly at 60 mg/kg for 24 hr, 1 of the 5 evaluable patients showed reduced hepatic metastatic lesions. One of 4 patients receiving IVP administration weekly at 120 mg/kg for 48 hr showed a disappearance of metastatic lesions in the skeletal muscle, but bone marrow suppression was observed as dose-limiting toxicity. Pharmacokinetics were more stable in IVP than in IVG with less individual difference in the plasma concentrations. Among the outpatients receiving short-time iv, IVG administration once or twice a week, 2 patients given weekly administrations at 20 mg/kg for 60 min showed slight adverse reactions. In 6 patients given high-dose administrations, bone marrow suppression was observed. When pharmacokinetics in the patients given 5-FU for 60 min were compared between the IVG and IVP groups, there were individual differences in plasma concentrations, but the differences were not significant. It was concluded from above results that the following practical dose schedules would be recommendable: 60 mg/kg for 24hr/week by IVP for inpatients and 20 mg/kg for 60 min/week by IVG for outpatients.

Detection of a nucleolar 7-2 ribonucleoprotein and a cytoplasmic 8-2 ribonucleoprotein with autoantibodies from patients with scleroderma.

In studies on antinucleolar antibodies in sera from 24 patients with scleroderma, an autoimmune disease, one serum, designated "anti-To", contained antibodies against a nucleolar 7-2 ribonucleoprotein and a novel cytoplasmic 8-2 ribonucleoprotein. The 7-2 and 8-2 RNAs are distinct RNAs with a pppG terminus. They are partially conserved between rat and human species and are present in distinct ribonucleoprotein particles. Eight sera contained antibodies that precipitated particles containing nucleolar U3 RNA; these antibodies appear to be directed against preribosomal particles containing U3 ribonucleoprotein, rather than the U3 ribonucleoprotein particles alone. All these ribonucleoproteins required proteins for antigenicity. These antibodies will be of use in studies on the structure and function of these novel small ribonucleoproteins.

Ultrastructural and purification studies on human tumor nucleolar antigens and nucleolar particles.

The presence of common nucleolar antigens in a broad array of human malignant tumors has led to several lines of investigations. In addition to studies on an increasing number of benign and malignant neoplasms with a variety of antibodies designed to statistically evaluate the presence of nucleolar antigens, purification procedures and chemical analyses are being used to characterize the specific antigens. The localization of the nucleolar antigens in HeLa cells was studied by the postembedding immunoelectron microscopic procedure employing rabbit antibodies to nucleoli or nuclear Tris extracts of these cells. The products of the peroxidase-antiperoxidase complexes visualized by the reaction with diaminobenzidine in nucleoli were mainly found in the nucleolonemas which contain the dense nucleolar RNP components. When these nucleoli became compact after treatment of HeLa cells with adriamycin, the distribution of the immunoreactive products was altered along with distribution of the dense nucleolar components. The human nucleolar antigens were mainly localized to nucleolar regions containing the nucleolar RNP components. Improved purification of the antigens made it possible to provide a satisfactory amino acid analysis of one pI 6.3 antigen. Interestingly, some of the nucleolar antigen was found in miniparticle undescribed until now.

Comparison of RNase T1 fingerprints of U1, U2, and U3 small nuclear RNA's of HeLa cells, human normal fibroblasts, and Novikoff hepatoma cells.

To determine whether there are differences between the U1, U2, and U3 small nuclear RNA's of human cancer cells (HeLa cells) and human normal fibroblasts (IMR-90 cells), and between these uridine-rich small nuclear RNA's of human and Novikoff hepatoma cells, the cells were first incubated in Eagle's medium with [32P]Pi to label these RNA's uniformly. No differences were found between the RNase T1 fingerprints of the purified U1, U2, and U3 RNA's of HeLa cells and IMR-90 cells. The RNase T1 fingerprints of U1 RNA's from human tissues were very similar to that of the U1 RNA of Novikoff hepatoma cells. The RNase T1 fingerprints of U2 and U3 RNA's from human tissues had many similarities to those of Novikoff hepatoma cells, but a few differences were found, such as a point mutation of the U-U-Gp in the rat U2 RNA to A-U-Gp (U leads to A) in human U2 RNA. Unlike the three U3 RNA's of Novikoff hepatoma cells, U3 RNA from human tissues appears to be only one species. These results indicate that U1, U2, and U3 RNA's of human cancer cells are essentially the same as those of human normal cells. In addition, the uridine-rich small nuclear RNA's appear to be conserved through evolution.