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Biomedical subjects

J Mattsson

Publications and source records attributed to J Mattsson.

85 records · Page 5Linked to original sources
PubMed1991

Aggregation of microspheres in blood flow measurements.

The aggregation of NEN-TRAC radionuclide-labeled 15 microns resin microspheres was studied in vitro and in vivo. In vitro, the control group not agitated at all was compared with groups subjected to agitation with a Vortex Shaker or agitation with first a Vortex shaker and then a sonification bath. Loading the microspheres in a catheter made agitation unnecessary (5.6 +/- 1.7 aggregates/100 spheres and 2.3 +/- 0.5 microspheres/aggregate). Sonification increased aggregation when the solution was drawn into 1 cc syringes (13.7 +/- 2.6 aggregates/100 spheres and 2.8 +/- 1.2 microspheres/aggregate). In vivo less aggregates were observed. Loading the microspheres into PK 50 catheters and then injecting them into the left ventricle of the heart after agitation in a Vortex shaker for 1 min minimized aggregation (1.6 +/- 1.0 aggregates/100 spheres and 2.2 +/- 0.4 spheres/aggregate). Sonification increased both the number of aggregates and the number of spheres in each aggregate significantly (10.0 +/- 3.1 aggreates/100 spheres and 2.8 +/- 1.3 spheres/aggregate). Aggregates of 10 to 40 microspheres were occasionally observed. When the microspheres were injected into the aorta at the level of the diaphragm, one large aggregate (approximately 50 spheres) was seen. The handling of the microsphere solution is important to prevent aggregation and the treatment recommended by the manufacturer does not seem to be the optimal. Large aggregates, which are rare, might embolize the precapillary arteries. Small aggregates are more common and they might result in disproportionately fewer microspheres in vessels than their actual blood flow. This would make the microsphere method less reliable in blood flow measurements.

Animals↗
PubMed1984

Intratumor distribution of capillary permeability surface area product (PS) correlated to tumor vascular space and blood flow.

The intratumor distribution of the capillary permeability surface area product (PS) correlated to the intratumor distribution of vascular space and of blood flow was studied by labeled albumin in a transplantable rat fibrosarcoma. A wide heterogeneity in intratumor distribution of PS was found. The tumor PS values were not significantly correlated to tumor vascular space or to blood flow values. This might suggest that intravascularly administered drugs could reach a comparative high intratissue concentration also in less vascularized tumor areas.

Albumins↗
PubMed1983

Influence of vasoactive drugs on the intratumor distribution of blood flow and vascular volume in a transplantable rat fibrosarcoma.

The intratumor distribution of plasma volume and of blood flow was studied simultaneously by radioisotope techniques in a transplantable rat fibrosarcoma. Intravenous administration of norepinephrine changed the distribution of both plasma volume and blood flow to produce low values in tumor and in normal muscle. Intravenous administration of papaverine was surprisingly followed by similar effects, probably due to a direct influence of papaverine on cardiac function. Intraaortal administration of papaverine into the studied tissue area did not influence tumor blood flow or plasma volume but increased normal muscle plasma volume. The results might support a previously suggested possibility that one can directly influence the tumor vascular bed with vasoconstricting drugs, while tumor vessels are more resistant to pharmacologic dilatation probably because of their normal state of close to maximal dilatation.

Animals↗
PubMed1982

Influence of vasoactive drugs on local tumor blood flow.

The influence of vasoactive drugs, including noradrenaline, isoprenaline and papaverine, on the local blood flow of a transplantable rat sarcoma and of normal subcutaneous tissue of the rat was studied by local [133 xenon] clearance technique. The microvascular bed of the tumour was studied by transmission electron microscopy (TEM). Vessels with one layer of contractile cells were found in the tumour vascular bed by TEM. A significant reduction of both tumour and normal subcutaneous tissue blood flow was found after administration of noradrenaline added to the injected xenon solution. In a dose-response experiment the tumour and subcutaneous vascular beds seemed to be equally sensitive to noradrenaline. Isoprenaline did not influence the blood flow in either subcutaneous tissue or tumour, while papaverine increased subcutaneous tissue blood flow significantly but did not influence tumour blood flow. The results of the present blood flow studies might suggest that the tumour vascular bed is normally in a state close to maximal dilatation.

Animals↗
PubMed1978

Solitary calcaneal metastasis as the first sign of gastric cancer. A case report.

A case of gastric adenocarcinoma is reported where the first symptom was a solitary calcaneal metastasis. The metastastic symptoms occurred in previously fractured bone, one year before the onset of gastric symptoms. This history is rare and the eight cases found in the literature where gastric cancer has started with solitary bone metastasis are reviewed.

Adenocarcinoma↗
PubMedDate not supplied

Intratumoral distribution of microspheres.

Fifteen mu carbonized microspheres injected in two transplantable rat tumors, a hepatoma transplanted to the dorsum of one hindpaw and an adenocarcinoma transplanted into the liver, were found to be unevenly distributed and often in aggregates that seemed to fill intratumoral vessels. This finding can partly explain the increased vascular resistance in tumors after microsphere injection and makes the technique with repeated injections of microspheres disputable.

Animals↗