Study on the 24Na specific activity induced by external neutron irradiation based on ICRP 110 computational phantoms.

The dose caused by external exposure to neutrons can be evaluated by measuring the induced 24Na activity due to interaction of 23Na in human body with neutrons. To investigate the difference between male and female in the 24Na activity, the MCNP code is used to simulate the ICRP 110 adult male and female reference computational phantoms irradiated by 252Cf neutrons. The results show that the average absorbed dose of whole body caused by per unit neutron fluence for the female phantom is (5.22 ± 0.06)% - (6.84 ± 0.05)% higher than that for the male phantom. The 24Na specific activity of male tissues/organs is higher than that of female, except muscle tissues, bone, colon, kidney, red marrow, spleen, gallbladder, rectum and gonads. The highest intensity of 24Na characteristic gamma rays on the body surface occurred at Z = 125 cm on the back for the male phantom, while the highest gamma ray fluence for the female phantom is at Z = 116 cm, both of which are aligned with liver. When 1 Gy of 252Cf neutrons irradiate the ICRP110 phantoms, (1.51-2.44) × 105 and (3.70-5.97) × 104 24Na characteristic gamma rays can be recorded in 10 min by 3-inch NaI(Tl) detector and Φ 5 × 3 cm3 HPGe detector, respectively.

[Copper ion electrochemistry in treatment of bleeding and prolapse due to hemorrhoid, experimental and clinical studies].

OBJECTIVE: To observe the effect of copper ion electrochemistry (CIE) in treatment of bleeding and prolapse due to hemorrhoid. METHODS: Bleeding was caused at several points on the sacrospinal muscles of 26 rabbits. Routine hemostasis was used at one side (control side) and CIE was used on the opposite side (experimental side). The stanch times at the different sides were recorded. Then the rabbits were killed. Pathological examination was made to the lung, liver, and kidney to observe the amount of small thrombus and inflammation. CIE was performed at the right side of anus of 6 dogs and the right side was used as control side. Tissue specimens of rabbit muscle and dog anus mucosa were collected to examine the copper ion concentration. A copper needle was inserted into each pile to the depth of 10 - 15 mm for 4'40" (with the mean number of treated points of 9.8) upon 202 patients suffering from bleeding due to hemorrhoid, 79 with inner hemorrhoids and 123 patients with mixed hemorrhoids (experimental group). Another 171 patients suffering from bleeding due to hemorrhoid, 64 with inner hemorrhoids and 107 with mixed hemorrhoids were treated with suppository as controls. CEI was performed on 128 patients suffering from prolapse of hemorrhoid, 41 with inner hemorrhoids and 87 with mixed hemorrhoids (experimental group). Another 115 patients suffering from prolapse of hemorrhoid, 40 with inner hemorrhoids and 75 with mixed hemorrhoids were treated with suppository as controls. Biopsy specimens of anus mucosa were taken from 18 patients with mixed hemorrhoid who underwent CIE. The copper ion concentration was measured in 30 patients undergoing CIE. RESULTS: The stanch time in the experimental side of rabbit was (1.16 +/- 0.18) min, significantly shorter than that in the control side [(2.13 +/- 0.46) min, P = 0.0037]. Extensive small thrombi and edema of vascular wall were seen in the rabbit liver, lung, kidney, and muscle tissues in comparison with the tissues of the control side (P < 0.01). Copper ion complex was seen in the experimental rabbit tissues. The copper ion concentration was significantly higher in the experimental area of dog anus mucosa than in the control area. Clinical study showed that after CIE the curative rate for bleeding was 95.5%, significantly higher than that of the control group (8.8%, U = 44.6, P < 0.001). The curative rate for prolapse in the experimental group was 60.8%, significantly higher than that of the control group (20.9%, U = 313.2, P < 0.01). No patient felt pain while treated and later. After the CIE treatment, the patients only needed to take a rest for 4 hours. Pathology showed there were much more small thrombi in the treated tissues. The blood copper ion concentration in the trial group did not increase significantly after CIE in comparison with that before treatment. CONCLUSION: CIE is safe, effective and easy to perform in treatment of bleeding and prolapse due to hemorrhoid.