Effect of well chamber altitude pressure corrections for cesium Blu Cs and CivaDot Pd brachytherapy sources.

Purpose: Previous publications have described how the standard temperature and pressure correction will overcorrect measurements with a low-energy photon low-dose rate brachytherapy source at low ambient air pressures. To account for this effect, an additional correction factor is applied after the standard temperature and pressure correction. This additional correction is dependent on the source being measured and the chamber it is measured in.

Synchroton-produced ultrasoft X rays: equivalent cell survival at the isoattenuating energies 273 eV and 860 eV.

In this paper we report on survival of Chinese hamster V79 and mouse C3H 10T1/2 cells after irradiation with synchrotron-produced 273 eV and 860 eV ultrasoft X rays. These two energies, which are available by multilayer monochromatization of the synchrotron output spectrum, exhibit equal attenuation within living cells. Such an isoattenuating energy pair allows the direct examination of how biological effectiveness varies with the energy of the ultrasoft X rays.

Human growth hormone (hGH) secretion in milk of goats after direct transfer of the hGH gene into the mammary gland by using replication-defective retrovirus vectors.

Mammary-specific promoters have been used in transgenic animals to limit transgene expression to the mammary gland. Gene therapy techniques to target just one organ for introduction of a foreign gene have also been demonstrated. We have directly infused replication-defective retroviruses encoding hGH into the mammary gland of goats via the teat canal during a period of hormone-induced mammogenesis.

Limonene chemoprevention of mammary carcinoma induction following direct in situ transfer of v-Ha-ras.

Monoterpenes, including limonene and its in vivo rat plasma metabolites, have been shown to be inhibitors of protein isoprenylation of small G proteins, including p21 ras. In addition, dietary limonene has been shown to be capable of preventing the development and causing the regression of chemically induced mammary carcinomas, many of which contain activated ras oncogenes. On the basis of these observations, it was hypothesized that a possible mechanism by which limonene exerts its effects on the chemoprevention and regression of mammary tumors involves the inhibition of protein isoprenylation of the small G protein p21.

Genetic identification of Mcs-1, a rat mammary carcinoma suppressor gene.

Women have inherited differences in their susceptibility to breast cancer, but the genes underlying this variation are difficult to identify. We have approached the problem of identifying breast cancer susceptibility genes by using a rat model. Inbred rat strains display differential susceptibilities to mammary carcinogenesis; the Copenhagen (COP) rat is resistant, while the Wistar-Furth (WF) rat is susceptible to induction of mammary tumors by 7,12-dimethylbenz[a]anthracene.