Biomedical subjects

U Stenram

Publications and source records attributed to U Stenram.

147 records · Page 9Linked to original sources

PubMedDate not supplied

Adverse effects at adjuvant treatment of liver metastases in rat with RSU-1069 + microspheres, or liposomal MTP-PE.

UNLABELLED: Rats were inoculated via the portal vein with a suspension of tumor cells from a transplantable dimethylhydrazine-induced adenocarcinoma of rat colon. In one set of experiments, the bioreductive drug RSU-1069 was injected once via the portal vein with or without degradable starch microspheres (DSM) 10 mins after tumour cell inoculation. In another set the immunostimulator liposomal-encapsulated muramyl tripeptide phosphatidyl-ethanolamine (MTP-PE) was injected via the portal vein or penile vein 1 day before tumour-cell inoculation and then twice a week. The experiments were finished after 2 to 3 weeks. Tumour take, numbers and volumes were measured. RESULTS: RSU-1069 enhanced tumour growth when combined with DSM. Liposomal MTP-PE also increased tumour growth. CONCLUSION: A bioreductive drug combined with microspheres, known to suppress the growth of an established tumour, may enhance its growth in the adjuvant setting. An accepted immunostimulator may enhance tumour take. Drugs used for the treatment of tumours must be carefully employed, if applied in an adjuvant setting. The effect on the normal immune system should be further studied.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMedDate not supplied

Angiogenesis inhibitor TNP-470 augments the effect of repeated arterial ischemia on growth but does not affect take in a rat liver tumor model.

Transient hepatic arterial occlusion causes necrosis in solid hepatic tumors in the rat, but regrowth of tumor cells and capillaries takes place from the tumor periphery. It was therefore considered of interest to combine this treatment with the angiogenesis inhibitor TNP-470 (therapeutic model). Wistar rats with a dimethylhydrazine-induced adenocarcinoma implanted into the liver received one of the following treatments: TNP-470 + transient hepatic ischemia, transient hepatic ischemia alone, TNP-470 alone or sham solution alone. Rats were sacrificed one week after the start of treatment. In addition, we investigated if TNP-470 decreases the risk of tumor take in the liver after intraportal injection of viable tumor cells (adjuvant study). Transient hepatic ischemia combined with TNP-470 gave a smaller increase in tumor volume than transient hepatic ischemia (p < 0.01), TNP-470 (p < 0.001) alone or no treatment (p < 0.001). Transient hepatic ischemia or TNP-470 caused a significant suppression of tumor growth when compared to controls (p < 0.01 in both cases). In the adjuvant study, TNP-470 caused retardation of tumor growth (p < 0.01 as compared to controls) but did not affect tumor number. It is concluded that TNP-470 suppressed tumor growth, both alone and in combination with transient hepatic ischemia, but did not affect take of tumor.

Animals↗

PubMedDate not supplied

Interstitial laser thermotherapy in pig liver: effect of inflow occlusion on extent of necrosis and ultrasound image.

BACKGROUND/AIMS: The aim was to investigate the effect of blood inflow occlusion on lesion size and ultrasonographic findings during interstitial laser thermotherapy of normal liver. METHODOLOGY: Pigs were treated with or without hepatic inflow occlusion at a laser power of 3W or without inflow occlusion at 5 W (target temperature 43 degrees C). The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit. Ultrasonography was performed immediately after treatment. Lesion size was determined using light microscopy including immunohistochemistry with bromodeoxyuridine. RESULTS: Hyperechoic ultrasonographic changes were observed after treatment with inflow occlusion or when there was carbonization. If carbonization did not occur, unoccluded blood flow was associated with hypoechoic lesions. Following inflow occlusion, maximum lesion width 2 and 6 days after thermotherapy averaged 21.9 +/- 1.3 and 20.2 +/- 0.8 (means +/- SEM) mm, respectively. This was larger than the corresponding values of 10.8 +/- 0.8 and 11.1 +/- 2.0 observed after treatment without inflow occlusion at 3W (p < 0.01). Increase in laser power from 3 to 5W in experiments without inflow occlusion produced early carbonization and a slight increase in lesion size that did not match that produced by inflow occlusion. Ultrasound gave a correct prediction of necrosis size after treatment with inflow occlusion but overestimated the necrosis when inflow occlusion was not used. Ultrasound was furthermore unable to predict size of necrosis in individual experiments. CONCLUSION: Blood flow has a major influence on lesion size in interstitial laser thermotherapy of the liver and affects ultrasonographic images. Also, it appears that intraoperative ultrasonography cannot monitor lesion size with an accuracy that is sufficient for clinical use.

Animals↗