As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all ...

background: melatonin is a free radical scavenger. it has also antioxidant effects through its stimulatory actions on antioxidant system. objective: we conducted this study to examine the effect of different oral doses of melatonin on liver tissue. methods: we used 42 rats—6 rats in each group. group i served as the control group; group ii rats were pretreated with only melatonin; group iii was...

Absorption of energy from ionizing radiation by the genetic material in the cell leads to damage to DNA, which in turn leads to cell death, chromosome aberrations and gene mutations. While early or deterministic effects result from organ and tissue damage caused by cell killing, latter two are considered to be involved in the initial events that lead to the development of cancer. Epidemiologica...

The 8-pin 555 time rs were exposed to 1,2,3,4, up to 5 Mrads gamma doses, using Co 60 as a gamma radiation source, with a total absorbed doses 5Mrads , the output of the chip, as a square wave indicate that , the electromagnetic wave (gamma radiation) affect in the operation of the timer, as : the parameter changed during radiation noise in the generated square wave, frequency (f) and duty-cycl...

annually, many people are irradiated for diagnostic and therapeutic purposes. assessment of radiation dose and its related risks to patients are important issues in radiation protection dosimetry. the complex mathematical calculations of the absorbed and effective doses are now done with computers. the calculations are performed with the help of anthropomorphic computational models of human bod...

Cell number. protein. and phorbol myristate acetate (PMA)-induced H202 production were measured in cultured human peripheral blood monocytes for six days after exposure to varying doses of ‘y-radiation. Both the number of adherent cells and the protein per dish decreased with increasing radiation doses. The dose of radiation decreasing the number of adherent cells by 37% on days 4 and 6 postirr...

A major concern of exposure to low doses of radiation is the risk of cancer induction. Epidemiologic data are rarely powerful enough to accurately discriminate this risk at doses <10 cGy. In order to gain insight into events at these low doses, laboratory-based studies of relevant endpoints are required. One such endpoint is radiation-induced neoplastic transformation in vitro. Such studies can...

For patients with locally advanced primary or recurrent gynecologic cancers, prognosis is poor. Doses of external beam radiation therapy required to treat either gross or microscopic disease in patients previously irradiated or treated surgically exceed doses that are tolerated by normal anatomic structures. Intraoperative radiation therapy allows maximal tumor control achievable with radiation...

PURPOSE To estimate the doses of radiation to organs of interest during treatment of childhood cancer for use in an epidemiologic study of possible heritable diseases, including birth defects, chromosomal abnormalities, cancer, stillbirth, and neonatal and premature death. METHODS AND MATERIALS The study population was composed of more than 25,000 patients with cancer in Denmark and the Unite...

UNLABELLED In response to U.S. Pharmacopeia general chapter <797> standards, a clean room was constructed for our in-house radiopharmacy. Previously, most patient doses were prepared as needed just before injection. Currently, to minimize repeated entries into the clean room, most patient doses are prepared in batches; that is, early morning and noontime preparation of doses to be injected at v...