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Biomedical subjects

R Nemoto

Publications and source records attributed to R Nemoto.

At least 127 records · Page 7Linked to original sources
PubMed1981

A model of malignant urinary bladder tumor in rabbits.

We attempted to produce a malignant urinary bladder tumor in rabbits by transplanting tumor cells. Each of 51 male mixed-bred rabbits received 0.3 ml V2 carcinoma cell suspension. The transplantation was done after laparotomy via injection into the bladder wall. Within 2 weeks malignant tumors were observed in the bladder. Without any manipulation to the mucosa, all of the tumors were led to exulceration into the bladder lumen. The incidence of malignant tumor reached 96 per cent. Metastases in these animals were seen in the lungs and para-aortic lymph nodes. This malignant tumor model seems especially suitable for the study of new methods of transurethral treatment of bladder cancer.

Animals↗
PubMed1981

Urinary cytology as a test in mass screening.

A rapid and simple cytologic screening system for urinary tract cancer stained with toluidine blue was described. Utilizing this system, a hospital population was screened for urinary tract cancer from specimens sent for routine urinalysis. In this study of 16,062 fresh urine sediments selected at random from non-urologic patients, three cases histologically proven bladder cancer were detected, leading to the detection rate of one bladder cancer in 5,000 individuals. The results emphasizes the usefulness of this simple screening technique in combination with clinical urinalysis and cytology for early detection of urinary tract malignancy.

Cytodiagnosis↗
PubMed1980

Sustained-release properties of microencapsulated mitomycin C with ethylcellulose infused into the renal artery of the dog.

Mitomycin C (MMC) was microencapsulated with ethylcellulose. The microcapsules contained, on average, 80% of biologically active MMC and had a sustained-release property. The mean particle size was 224 micrometers so that the microcapsules were readily infused into a canine kidney through arterial catheterization. Ex vivo infusion demonstrated that the microcapsules lodged in the small arteries, mainly at the cortico-medullary junction, and released concentrated MMC into the surrounding tissue. In vivo experiments revealed that the canine kidneys infused with the microcapsules retained active MMC for more than 6 hours and showed extensive necrosis five days after the infusion. The kidneyks infused with nonencapsulated MMC rapidly excreted MMC and showed mild histologic changes. The blood level of MMC released from the intrarenal microcapsules was markedly reduced as compared with control levels. The results suggest that the potential therapeutic effect of intraarterial infusion of MMC microcapsules is a function of embolization and prolonged drug action, and that selective infusion of MMC microcapsules into tumor-supplying arteries could facilitate intensive topical chemotherapy with minimum systemic side-effects.

Animals↗
PubMed1980

Rapid assay system for cytotoxicity tests using 14C-leucine incorporation into tumor cells.

Cell viability under various conditions of cytotoxicity test was assessed by terminal labeling of tumor cells, T24 cell line derived from urinary bladder carcinoma, with 14C-leucine. Changes of 14C-leucine incorporation into the cells were fairly proportional to those of viable cell number measured by the trypan blue exclusion method, but a definite correlation between the two measurements was not always found following cytotoxic manipulations. When the cells were labeled immediately after drug treatments, 14C-leucine incorporation usually led to fluctuated and insensitive results presumably due to disturbed metabolic activities unrelated to cell viability and failed to indicate the degree of cell damage. It was shown, however, that the cytotoxicity test was satisfactorily determined by labeling tumor cells with 14C-leucine after recovery in fresh medium for 24 hr. Cytotoxic effects of anticancer drugs with concentration- and time-dependency, hyperthermia and phytohemagglutinin-stimulated lymphocytes were demonstrated by the radioactivity incorporated into the target cells on day 2 after removal of the cytotoxic factors. The results indicate that the terminal labeling of tumor cells with 14C-leucine can be used as a rapid and reliable measure sensitive to cell viability for an in vitro assay system.

Antineoplastic Agents↗
PubMed1980

Microencapsulated mitomycin C in transcatheter embolization of dog kidney.

Microencapsulated mitomycin C (MMC) was utilized for arterial embolization of dog kidneys. Renal damage was evaluated by angiographic and pathologic examinations. The most extensive embolic necrosis was associated with the use of microencapsulated MMC compared to blank microcapsules, nonencapsulated MMC, and a combination of both. Arterial infusion of microencapsulated MMC kept the concentration of MMC low in the circulating blood and sustained the biological potential of MMC in the kidney for prolonged periods of time as compared with nonencapsulated MMC. Transcatheter infusion of microencapsulated MMC could be clinically applied to the therapeutic arterial embolization of the tumor-supplying vessels together with regional anticancer chemotherapy.

Animals↗