No abstract

We have studied the mechanism of tumour uptake of 201Tl by in vivo and in vitro studies. In a series of patients with breast cancer (n = 26), lung cancer (n = 56) and lymphoma (n = 15), the time course of tumour uptake of 201Tl paralleled that in the myocardium with almost identical times of peak uptake being obtained in tumours and myocardium. In a patient with hepatic metastases from colonic cancer undergoing laparotomy, 99mTc labelled microspheres and 201Tl were injected into the hepatic artery and biopsies of metastatic and normal liver tissue obtained. The tumour to normal liver activity ratios for 201Tl were one tenth of those for 99mTc microspheres. In the final part of the study, cells from a lung cancer tissue culture line were incubated for 30 min with 201Tl with and without the addition of cardiac glycoside, which acts a sodium potassium pump blocker. The cells exposed to the cardiac glycoside showed markedly decreased uptake of 201Tl compared to the cells not so exposed (0.6% +/- 0.1% vs 11.8 +/- 0.7.2% of the administered dose). The mechanism of 201Tl uptake of tumours is similar to that in the myocardium. Sodium potassium pump activity appears to be more important than tumour blood flow. 201Tl uptake may provide a useful means of studying tumour viability.

Sunscreen formulations containing UVB filters, such as Zinc-oxide (ZnO) and titanium-dioxide (TiO2) nanoparticles (NPs) have been developed to limit the exposure of human skin to UV-radiations. Unfortunately, these UVB protective agents have failed in controlling the skin cancer incidence. We recently demonstrated that silver nanoparticles (Ag-NPs) could serve as novel protective agents against UVB-radiations. Here our goal was to perform comparative analysis of direct and indirect UVB-protection efficacy of ZnO-, TiO2- and Ag-NPs. Sun-protection-factor calculated based on their UVB-reflective/absorption abilities was the highest for TiO2-NPs followed by Ag- and ZnO-NPs. This was further confirmed by studying indirect protection of UVB radiation-induced death of HaCaT cells. However, only Ag-NPs were active in protecting HaCaT cells against direct UVB-induced DNA-damage by repairing bulky-DNA lesions through nucleotide-excision-repair mechanism. Moreover, Ag-NPs were also effective in protecting HaCaT cells from UVB-induced oxidative DNA damage by enhancing SOD/CAT/GPx activity. In contrast, ZnO- and TiO2-NPs not only failed in providing any direct protection from DNA-damage, but rather enhanced oxidative DNA-damage by increasing ROS production. Together, these findings raise concerns about safety of ZnO- and TiO2-NPs and establish superior protective efficacy of Ag-NPs.

Serum levels of CA 125 and markers reputed as specific for cancers in relevant locations (squamous cell carcinoma, SCC, carcinoembryonic antigen, CEA, CA 19.9, α-fetoprotein, AFP) were determined in 107 patients with gastrointestinal (GI) carcinomas. The aim of this study was to assess their individual and combined sensitivities, and the power of CA 125 in excluding primary ovarian epithelial cancer from GI primary. Serum CA 125 levels (in U/ml) ranged from nondetectable to 400 in patients with esophageal, to 570 in those with gastric, and to 300 in patients with colorectal carcinoma. The levels for liver secondaries, pancreatic, and hepatocellular carcinoma were 480, 2,720 and 1,100 U/ml, respectively. Serum SCC antigen was elevated in all patients with esophageal cancer, CEA or CA 19.9 in 52% of patients with gastric cancer and in 63% with liver secondaries, and CEA in 95% of patients with colorectal cancer; whereas serum CA 125 above 65 U/ml was found in 25% of this subgroup, but only in those with already an elevated concentration of specific marker(s). Serum CEA or CA 19.9 was elevated in 71%, CA 125 in 59% of patients with pancreatic cancer; the latter mostly in those with already elevated CEA or CA 19.9. Serum AFP was elevated in 84% and CA 125 in 40% of patients with hepatoma; the latter mostly in those with already an elevated AFP. CA 125 values exceeding 1,000 U/ml were found in 1 patient with pancreatic cancer (2,720 U/ml) and in 2 with hepatoma (1,050 and 1 100 U/ml). These findings illustrate the nonspecificity of the CA 125 antigen, its small if any advantage compared to the specific markers, and they diminish its role as a marker for primary ovarian cancer from GI primary unless it exceeds 2,800 U/ml.