In neuroimmune communication, the cholinergic system plays a key role in transmitting information vis-& agrave;-vis the peripheral immune status to the central nervous system and vice versa. Exposure to ionizing radiations (photons and charged particles) either for medical purposes (radiotherapy and radiodiagnostic) or during radiation accidents can affect the cholinergic system. As such, the administration of cholinergic medications, before or after exposure, can minimize the side effects of ionizing radiation on the cholinergic system. In literature, photon interaction parameters of cholinergic medications have been calculated. However, proton and alpha particle interactions parameters of cholinergic medications have not been investigated. This study, therefore, investigated the mass-stopping power (S(E)/rho), effective atomic number (Zeff), and electron density (Neff) of 12 cholinergic medications, namely arecoline, carbachol, diisopropyl fluorophosphate, donepezil, malathion, parathion, physostigmine, pilocarpine, rivastigmine, sarin, soman, and tabun for proton and alpha particles interaction. To investigate the parameters of each of the cholinergic medications, a compact and comprehensible cross-platform computer software known as PAGEX was used to compute the S(E)/rho, Zeff, and Neff for the proton and alpha particle interactions at an energy of 1 keV-10 GeV and 1 keV-1 GeV, respectively. The maximum value of the S(E)/rho of the cholinergic medications occurred at lower energy regions of about 0.045 <= E <= 0.1 MeV and 0.5 <= E <= 0.75 MeV for proton and alpha particle interactions, respectively. Based on the S(E)/rho, rivastigmine and parathion show the best and least radioprotective ability against proton and alpha particle radiations, respectively. Generally, it was observed that the medications with a lower Zeff have a higher S(E)/rho than those with a higher Zeff. For both proton and alpha particle interactions, the variation of the Neff with the Zeff has been observed to be linear throughout the entire energy region. It is thought that the S(E)/rho, Zeff, and Neff of the cholinergic medications for proton and alpha particle interactions investigated in this study will be useful in radiation dosimetry and will also be a buildup on future work that will focus on experimental findings on the radioprotective ability of the investigated medications against charged particle radiations.

Introduction: Elemental imbalances in breast cancer patients have been linked with carcinogenic processes which are responsible for the development and growth of breast malignancy. In medical applications of radiation, this elemental characterization is important in determining the radiation parameters which are fundamental in understanding the interaction of radiation with concerned tissue. This study aims to carry out an elemental characterization of malignant and healthy breast tissue and to determine their respective radiation parameters. Methods: Particle-induced X-ray emission (PIXE) procedure was used for the elemental characterization of the samples. The resulting elemental concentrations were used in calculating the photon radiation parameters with the aid of the “EpiXS” software. Results: Among the elements determined, Mg, Al, P, S, Cl, K, Mn, Zn, and Pb in the malignant group were found to be significantly higher than that of the healthy group at a 0.05 significance level. Although not significant, the effective atomic number (Zeff) and the electron density (ρe) of the malignant group were slightly higher than that of the healthy group and this causes the difference in the mass attenuation coefficients for photoelectric effect and pair production interactions of the two subjects. The healthy tissue which has the lower value of Zeff and ρe dominated the maximum values of EABF while the minimum values were dominated by the malignant breast tissue which has the higher Zeff and ρe. The variation in the photon radiation parameters between the two groups suggests that the two groups will behave differently when photons interact with them. Conclusion: The results obtained in this study will be helpful in radiation biological physics and thus be proven worthwhile in radiodiagnostic, radiation dosimetry, and radiation therapy of breast cancer.

In this study, we applied particle-induced X-ray emission (PIXE) spectroscopy to investigate the levels of trace elements in breast tissues and whole blood (cancerous and non-cancerous) of selected African women in Ile-Ife, Southwest Nigeria. Freeze-dried and homogenized specimens obtained through mastectomy from clinically diagnosed patients were made into 11-mm-diameter pellets. The pellets were irradiated with 2.5 MeV proton beam energy from a 1.7 MV 5SDH Tandem accelerator. The PIXE analytical system was calibrated with certified reference matrices of Bovine Liver and Animal Blood: NIST 1577a and IAEA-A-13, respectively. A total of 23 elements: Na, K, Ca, Cl, S, Al, P, Si, Zn, Pb, Br, Rb, Zr, Se, Sr, Mn, V, Ti, Cu, Fe, Ni, Cr, and Mg were detected. The results indicated that the levels were within 0.9-5288 and 0.6-2320 ppm in breast tissues and 0.3-17228 and 2.0-2475 ppm in the whole blood of cancerous and non-cancerous subjects, respectively. At the .05 level of significance, significant differences exist between these levels in the cancerous and non-cancerous breast tissues (t = 0.008) as well as the whole blood (t = 0.041). The results gave the baseline concentration of the observed trace elements in the normal and malignant subjects and indicated PIXE as a powerful tool for such investigation.