Tumor volume, increase

In the work of Cabrales and coworkers73 (Cuba), sixty male BALBC mice were used and Ehrlich tumors were implanted in them. When the tumor volumes reached 850 mm,3 four platinum electrodes were inserted into each tumor ECT was carried out at 4 mA for 21 minutes, total charge thus passed through each tumor was around 5 coulombs. Tumor volume decrease and necrosis percentage increase were significant in mice treated with ECT, in comparison with the control group without ECT. 

Initial antitumor activity, as judged by 11-20% decrease in tumor volume, and a 2-3 day increase in tumor doubling time. But at midtreatment, tumors regained control rate of volume increase Insufficient to kill 50%... 

Fig. 5 Effect of treatment type on the increase in tumor volume in mice inoculated with BLSC-KU cells. The animals in treatment groups received i.v. doses of doxorubicin via tumor-specific or non-specific liposomes on day 0, 3, and 7 after the initiation of treatment. The tumor-specific and non-specific liposomes were conjugated with MoAbs against leukemia cells and normal mouse IgG, respectively. (Adapted in part from Ref. l)...

As shown in Table (16) , Fr. 1 and Fr. 2at a dose of 100 mg/kg, twice daily significantly inhibited tumor volume and tumor weight on day 15. Furthermore, the above two fractions inhibited metastasis to the lung and the increase of lung weight that occurred in tumor-removed mice Table (16) . 

Only some of the antibody in ECF can be available to bind to tumor antigen at any instant since the tumor is localized to one site in the body. If antibody in an ECF volume equal to the tumor volume is presumed to be available, this would give tumor-binding sites the same accessibility as normal tissue sites. The increased permeability can be allowed for in a model by effectively multiplying the available antibody at the tumor site by a permeability factor of 5. 

Interstitial fluid pressures in normal tissues are approximately atmospheric or slightly sub-atmospheric, but pressures in tumors can exceed atmospheric by 10 to 30mmHg, increasing as the tumor grows. For 1-cm radius tumors, elevated interstitial pressures create an outward fluid flow of 0.1 fim/s [11]. Tumors experience high interstitial pressures because (i) they lack functional lymphatics, so that normal mechanisms for removal of interstitial fluid are not available, (ii) tumor vessels have increased permeability, and (iii) tumor cell proliferation within a confined volume leads to vascular collapse [12]. In both tissue-isolated and subcutaneous tumors, the interstitial pressure is nearly uniform in the center of the tumor and drops sharply at the tumor periphery [13]. Experimental data agree with mathematical models of pressure distribution within tumors, and indicate that two parameters are important determinants for interstitial pressure the effective vascular pressure, (defined in Section 6.2.1), and the hydraulic conductivity ratio, (also defined in Section 6.2.1) [14]. The pressure at the center of the tumor also increases with increasing tumor mass. 

Zhang et al., (2007) 11 AII-frans-RA, 1 mg/kg 4-6 X X X 1-131 4 patients showed increased uptake Tg decreased in 4 patients and increased in 4 patients. Tumor volume showed partial response in 5 patients 2 patients had stable disease... 

The process of drug deposition depends on the distribution volume. When a drug is associated with a carrier, the rate of drug clearance is decreased (the half-life increases), and the volume of distribution is decreased. Consequently, it promotes tumor uptake [85]. The size of the carrier (normally 5 200 mn) minimizes penetration of the drugs into the organs and renal clearance. The volume distribution of the carrier is similar to the plasma volume when the blood circulation of the drug carrier is increased and the drug release rate from the carriers is slow [2]. Therefore, this limited distribution volume increases the maximum tolerated dose (MTD), as in the case of HPMA copolymer-linked doxorubicin [86]. 

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