• Title/Summary/Keyword: dose conversion

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Efficacy evaluation of novel organic iron complexes in laying hens: effects on laying performance, egg quality, egg iron content, and blood biochemical parameters

  • Jiuai Cao;Jiaming Zhu;Qin Zhou;Luyuan Zhao;Chenhao Zou;Yanshan Guo;Brian Curtin;Fei Ji;Bing Liu;Dongyou Yu
    • Animal Bioscience
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    • v.36 no.3
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    • pp.498-505
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    • 2023
  • Objective: This study was conducted to determine the optimal dose of novel iron amino acid complexes (Fe-Lys-Glu) by measuring laying performance, egg quality, egg iron (Fe) concentrations, and blood biochemical parameters in laying hens. Methods: A total of 1,260 18-week-old healthy Beijing White laying hens were randomly divided into 7 groups with 12 replicates of 15 birds each. After a 2-wk acclimation to the basal diet, hens were fed diets supplemented with 0 (negative control, the analyzed innate iron content was 75.06 mg/kg), 15, 30, 45, 60, and 75 mg Fe/kg as Fe-Lys-Glu or 45 mg Fe/kg from FeSO4 (positive control) for 24 wk. Results: Results showed that compared with the negative and positive control groups, dietary supplementation with 30 to 75 mg Fe/kg from Fe-Lys-Glu significantly (linear and quadratic, p<0.05) increased the laying rate (LR) and average daily egg weight (ADEW); hens administered 45 to 75 mg Fe/kg as Fe-Lys-Glu showed a remarkable (linear, p<0.05) decrease in feed conversion ratio. There were no significant differences among all groups in egg quality. The iron concentrations in egg yolk and serum were elevated by increasing Fe-Lys-Glu levels, and the highest iron content was found in 75 mg Fe/kg group. In addition, hens fed 45 mg Fe/kg from Fe-Lys-Glu had (linear and quadratic, p<0.05) higher yolk Fe contents than that with the same dosage of FeSO4 supplementation. The red blood cell (RBC) count and hemoglobin content (linear and quadratic, p<0.05) increased obviously in the groups fed with 30 to 75 mg Fe/kg as Fe-Lys-Glu in comparison with the control group. Fe-Lys-Glu supplementation also (linear and quadratic, p<0.05) enhanced the activity of copper/zinc-superoxide dismutase (Cu/Zn-SOD) in serum, as a result, the serum malonaldehyde content (linear and quadratic, p<0.05) decreased in hens received 60 to 75 mg Fe/kg as Fe-Lys-Glu. Conclusion: Supplementation Fe-Lys-Glu in laying hens could substitute for FeSO4 and the optimal additive levels of Fe-Lys-Glu are 45 mg Fe/kg in layers diets based on the quadratic regression analysis of LR, ADEW, RBC, and Cu/Zn-SOD.

The Adjuvant Effect of Subcutaneous Interferon-gamma in the Treatment of Refractory Multidrug-resistant Pulmonary Tuberculosis (난치성 다제내성 폐결핵에서 피하주사 Interferon-gamma 치료의 효과: 예비연구)

  • Kim, Eun Kyung;Shim, Tae Sun;Lee, Jung Yeon;Oh, Yeon-Mok;Lim, Chae-Man;Lee, Sang Do;Koh, Younsuck;Kim, Dong Soon;Kim, Won Dong;Kim, Woo Sung
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.3
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    • pp.226-233
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    • 2004
  • Background : Interferon-gamma (IFN-${\gamma}$) is a critical cytokine in the defense against a Mycobacterium tuberculosis infection. Even though IFN-${\gamma}$ has occasionally been used in the treatment of refractory multidrug-resistant tuberculosis (MDR-TB) with some promising results, there is still some controversy regarding the therapeutic efficacy of IFN-${\gamma}$. This study was performed to examine the effect of subcutaneous IFN-${\gamma}$ in the treatment of MDR-TB patients. Methods : Six patients with refractory MDR-TB were enrolled in this study. Two million IU of IFN-${\gamma}$ was administered subcutaneously three times a week with the concomitant administration of antituberculous drugs for at least for 28 weeks. During the IFN-${\gamma}$ therapy, the sputum smear and culture, radiological and clinical evaluations were performed every 4 weeks throughout the study period. Results : The mean age of the 6 patients was 37 years (ranges, 15-61 years). The drug susceptibility test to standard antituberculous drugs revealed resistance to an average of 6.8 (${\pm}1.2$) agents including isoniazid and rifampicin. An average of 10.8 (${\pm}1.3$) antituberculous drugs were prescribed before IFN-${\gamma}$ therapy. The culture became negative in 2 patients (33%) after initiating IFN-${\gamma}$ therapy; one at 8 weeks, and the other at 24 weeks. Finally, after stopping the IFN-${\gamma}$ therapy after 28 weeks, the culture became positive again in the two patients who were culture-negative. The other 4 patients who failed in the culture conversion are still on antituberculous treatment except for one who died of tuberculosis. Conclusion : Even though 28 weeks of subcutaneous IFN-${\gamma}$ therapy in combination with antituberculous drugs was successful in inducing the culture-negative conversion in some patients with refractory MDR-TB, the culture became positive again after stopping the IFN-${\gamma}$ therapy. This suggests that subcutaneous IFN-${\gamma}$ therapy may have suppressive effect on tuberculosis only during the IFN-${\gamma}$ therapy period in some patients. Further studies will be needed to determine the optimum dose, the administration route, the duration of therapy, and the predicting factors of the response to adjuvant IFN-${\gamma}$ therapy.

Study on the calibration phantom and metal artifacts using virtual monochromatic images from dual energy CT (듀얼 에너지 CT의 가상 단색 영상을 이용한 영상 교정 팬텀과 금속 인공음영에 관한 연구)

  • Lee, Jun seong;Lee, Seung hoon;Park, Ju gyung;Lee, Sun young;Kim, Jin ki
    • The Journal of Korean Society for Radiation Therapy
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    • v.29 no.1
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    • pp.77-84
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    • 2017
  • Purpose: To evaluate the image quality improvement and dosimetric effects on virtual monochromatic images of a Dual Source-Dual Energy CT(DS-DECT) for radiotherapy planning. Materials and Methods: Dual energy(80/Sn 140 kVp) and single energy(120 kVp) scans were obtained with dual source CT scanner. Virtual monochromatic images were reconstructed at 40-140 keV for the catphan phantom study. The solid water-equivalent phantom for dosimetry performs an analytical calculation, which is implemented in TPS, of a 10 MV, $10{\times}10cm^2$ photon beam incident into the solid phantom with the existence of stainless steel. The dose profiles along the central axis at depths were discussed. The dosimetric consequences in computed treatment plans were evaluated based on polychromatic images at 120 kVp. Results: The magnitude of differences was large at lower monochromatic energy levels. The measurements at over 70 keV shows stable HU for polystyrene, acrylic. For CT to ED conversion curve, the shape of the curve at 120 kVp was close to that at 80 keV. 105 keV virtual monochromatic images were more successful than other energies at reducing streak artifacts, which some residual artifacts remained in the corrected image. The dose-calculation variations in radiotherapy treatment planning do not exceed ${\pm}0.7%$. Conclusion: Radiation doses with dual energy CT imaging can be lower than those with single energy CT imaging. The virtual monochromatic images were useful for the revision of CT number, which can be improved for target coverage and electron densities distribution.

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