• 제목/요약/키워드: Exposure doses

검색결과 554건 처리시간 0.027초

Association Between Polymorphisms of Dihydrofolate Reductase and Gamma Glutamyl Hydrolase Genes and Toxicity of High Dose Methotrexate in Children with Acute Lymphoblastic Leukemia

  • Koomdee, Napatrupron;Hongeng, Suradej;Apibal, Suntaree;Pakakasama, Samart
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권7호
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    • pp.3461-3464
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    • 2012
  • Methotrexate (MTX) is an important drug for the treatment of childhood acute lymphoblastic leukemia (ALL). However, related toxicity occurs in many organs which may cause interruption of treatment, morbidity, and mortality. Single nucleotide polymorphisms (SNPs) of dihydrofolate reductase (DHFR) and gamma glutamyl hydrolase (GGH) are known to alter their enzymatic activity and thus affect the metabolism of MTX and influence the effectiveness. Therefore, we hypothesized that genetic variations of DHFR and GGH genes may influence the risk of toxicity after high dose MTX. The study population comprised of 105 children with ALL who were treated according to the modified St Jude Total XV protocol. The patients received 2.5 or $5g/m^2$ of MTX for 5 doses during the consolidation phase. Genotyping of DHFR 829C>T and GGH-401C>T was performed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The GGH-401CT and TT genotypes were associated with increased risk of leukopenia and thrombocytopenia after high dose MTX (OR 2.97, 95%CI; 1.24-7.13 and OR 4.02, 95%CI; 1.58-10.26). DHFR 829C>T was not associated with toxicity. In conclusion, the GGH-401CT and TT genotypes were found to increase the risk of severe leukopenia and thrombocytopenia after exposure to high dose MTX for childhood ALL therapy.

Survival of Mesothelioma in a Palliative Medical Care Unit in Egypt

  • Ibrahim, Noha;Abou-Elela, Enas;Darwish, Dalia
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권2호
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    • pp.739-742
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    • 2013
  • Background: This study was to evaluate the survival of patients with pleural and intraperitoneal malignant mesothelioma and to investigate the efficacy of chemotherapy (CT) as well as radiotherapy (RTH) and surgery compared to best supportive care (BSC). Materials and Methods: Forty patients with malignant mesothelioma (38 with pleural and 2 with intraperitoneal) were enrolled. Twenty seven patients underwent (CT) chemotherapy of which 2 also received (RTH) and surgery was only for biopsy in 15/40. Combination chemotherapy included cisplatin-gemcitabine, cisplatin-navelbine and cisplatin (or carboplatin) with premetrexed. Thirteen patients received only best supportive care. Results: A total of 12 (30%) patients were male, and 28 (70%) female. Median age was 54.0 years and the male/female ratio was 1/2.33 (P=0.210). Residential exposure played a major role in two regions, Helwan and Shoubra, in 20% and 15%, respectively. Overall mean survival time was $13.9{\pm}2.29$ months. That for patients who had received best supportive care was $7.57{\pm}1.85$ months, for chemotherapy was $16.5{\pm}3.20$ months, and multimodality treatment regimen $27{\pm}21.0$ months (P=0.028). Kaplan-Meier survival did not significantly vary for sex, residence and the pathological types epithelial, mixed and sarcomatous. The median survival for performance status and treatment modalities was significant (P=0.001 and 0.028). Best supportive care using opioids with a mean dose of 147.1 mg (range 0-1680) of morphine sulphate produced good subjective response and reasonable quality of life but did not affect survival. Conclusions: We conclude that CT prolongs survival compared to BSC in patients with malignant mesothelioma. Moreover, using escalating doses of opioids provides good pain relief and subjective responses.

두경부 전산화 단층촬영시의 주요 장기선량, 유효선량 및 위험도 (ORGAN DOSE, EFFECTIVE DOSE AND RISK ASSESSMENT FROM COMPUTED TOMOGRAPHY TO HEAD AND NECK REGION)

  • 김애지;조봉혜;나경수
    • 치과방사선
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    • 제25권1호
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    • pp.27-38
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    • 1995
  • The organ or tissue doses were determined with head and neck phantom measurement for multiple axial scans (36 slices), multiple coronal scans (13 slices), 3 types of single axial scans(orbit, maxillary sinus and mandibular canal) and single coronal scan (maxillary sinus). For each scan sequence 30 TLDs were placed in selected sites(16 internal sites and 14 external sites) in a tissue-equivalent phantom. The exposure was made at 120kVp, 500mAs with 5 mm slice width. The results were as follows : 1. In multiple axial scans, the greatest effective dose recorded was that delivered to the thyroid glands(2.77 mSv) and the least was that received by the skin(0.05 mSv). From these data, stochastic effects were 202.2x10/sup -6/ and 3.7×10/sup -6/, respectively. 2. In multiple coronal scans, the greatest effective dose recorded was that delivered to the salivary glands(0.58 mSv) and the least was that received by the skin(0.01 mSv). From these data, stochastic effects were 42.2×10/sup -6/ and 0.7×10/sup -6/, repectively. 3. Among single axial scans, the greatest effective dose recorded was that delivered to the salivary gland(0.38 mSv) in maxillary sinus scan. From this data, stochastic effect was 27.7×10/sup -6/. 4. In single coronal scan, the greatest effective dose recorded was that delivered to the salivary gland(0.01 mSv). From this data, stochastic effect was 1.0×10/sup -6/. 5. The equivalent dose measured that delivered to the lens of the eyes was 69.64 mSv in multiple axial scan, 39.32 mSv in multiple coronal scan and 36.77 mSv in single axial scan(orbit).

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Effect of Chelation with Calcium Disodium EDTA on Haemato-biochemical and Trace Mineral Profile in Blood from Lead Exposed Calves

  • Patra, R.C.;Swarup, D.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권8호
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    • pp.1130-1134
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    • 2005
  • An experiment was performed using 20 calves of about one-month old to investigate the effect of chelation therapy with calcium disodium ethylenediaminetetraacetate ($CaNa_2$EDTA) alone or along with antioxidant $\alpha$-tocopherol in lead loaded calves on blood trace minerals, erythrocytic sulfahydryl groups and some haematobiochemical parameters. Fifteen calves were given lead orally at a daily dose of 7.5 mg of 99% pure lead acetate/kg body weight for 28 days. Then the lead was withdrawn on day 28 and the calves were randomly divided into three groups. Each group of five animals was either treated with $CaNa_2$EDTA alone at the dose rate of 110 mg/kg body weight in two divided doses for 4 days or along with $\alpha$-tocopherol at the dose rate of 100 mg/kg body weight orally daily for 7 days, keeping the remaining five calves as lead-exposed untreated controls. Blood samples were collected at the end of the lead exposure (day 0) and thereafter on day 2, 4, 7 and 10 from the start of the chelation treatment. The treatment with EDTA alone led to slow but non-significant improvement in blood copper level, but incorporation of antioxidant $\alpha$-tocopherol in chelation therapy resulted in its significant decline, as recorded on day 7-post treatment. Withdrawal of lead or treatment with $CaNa_2$EDTA alone or along with $\alpha$-tocopherol enhanced the erythrocytic thiol contents and the levels of T-SH and P-SH became statistically (p<0.05) comparable to those of lead-exposed controls by day 7 and 4, respectively. There was no significant (p>0.05) change in serum urea, creatinine, total protein and albumin levels between the treatment groups. It is concluded from the present investigation that treatment with $CaNa_2$EDTA at the present dose rate is safe to be used for chelation in lead loaded calves.

Comparison Between Sodium Acetate and Sodium Chloride in Parenteral Nutrition for Very Preterm Infants on the Acid-Base Status and Neonatal Outcomes

  • Ali, Adli;Ong, Ee-Yan;Singh, Birinder Kaur Sadu;Cheah, Fook-Choe
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제23권4호
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    • pp.377-387
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    • 2020
  • Purpose: To compare between sodium acetate (SA) and sodium chloride (SC) in parenteral nutrition (PN) with associated metabolic acidosis and neonatal morbidities in preterm infants. Methods: Preterm infants below 33 weeks gestational age, and with a birth weight under 1,301 g were enrolled and further stratified into two groups: i) <1,000 g, or ii) ≥1,000 g in birth weight. The subjects were randomized to receive PN containing SA or SC within the first day of life. The results of routine blood investigations for the first 6 days of PN were collated, and the neonatal outcomes were recorded upon discharge or demise. Results: Fifty-two infants entered the study, with 26 in each group: 29 infants had extremely low birth weight (ELBW). There were no significant differences in birth weight, gestation, sex, exposure to chorioamnionitis and antenatal steroids, surfactant doses and duration of mechanical ventilation between groups. The SA group had significantly higher mean pH and base excess (BE) from days 4 to 6 than the SC (mean pH, 7.36 vs. 7.34; mean BE -1.6 vs. -3.5 [p<0.01]), with a two-fold increase in the mean BE among ELBW infants. Significantly fewer on SA required additional bicarbonate (n=4 vs. 13, p=0.01). The rate of bronchopulmonary dysplasia (BPD) was approximately four-fold lower in SA than SC (n=3 vs. 11, p<0.01). No significant differences were observed in necrotizing enterocolitis, patent ductus arteriosus, retinopathy of prematurity, cholestatic jaundice, and mortality between groups. Conclusion: The use of SA in PN was associated with reduced metabolic acidosis and fewer BPD.

인삼(人蔘)의 항(抗)스트레스작용(作用)에 관(關)한 연구(硏究) (Studies of Ginseng on the Antistress Effects)

  • 김낙두;한병훈;이은방;공재양;김명혜;진창배
    • 생약학회지
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    • 제10권2호
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    • pp.61-67
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    • 1979
  • Two pure saponin components, Panax saponin C (protopanaxatriol derivative, ginsenoside Re) and Panax saponin E (protopanaxadiol derivative, ginsenoside $Rb_l$) were isolated from Panax ginseng root and their acute toxicities in mice and antistress effects in rats were investigated. Average lethal doses $(LD_{50})$ of ginsenoside Re were 130mg/kg (i.v.), more than 1,000mg/kg (i.p.) and more than 1,500mg/kg (s.c.), respectively. Average lethal dose of ginsenoside $Rb_{1}$ was 243mg/kg intravenously. Adrenal ascorbic acid and cholesterol contents were significantly decreased when normal rats were exposed to heat $(40^{\circ}C)$ for 30 min. The reduction of the adrenal ascorbic acid and cholesterol contents in rats was partially prevented when the rats received the ginseng saponins prior to exposure to heat stress and most pronounced effects were observed in rats received ginsenoside Re. However, it was found that administration of ginseng alone, without stress, did not significantly change the ascorbic acid and cholesterol contents in adrenal glands. Eosinophil counts in the blood of the rats were elevated when the rats were exposed to the heat stress, and the elevation of the eosinophil counts were prevented with the ginseng saponins under the stress, but the changes were all insignificant statistically.

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MDCT 관상동맥 조영 검사에서 전향적 동조화 및 후향적 동조화 기법의 화질과 선량 관계 (An Estimate of Image Quality and Radiation Doses of Coronary Artery in MDCT Using Prospective and Retrospective ECG Gating Scan Mode)

  • 오종갑
    • 대한방사선기술학회지:방사선기술과학
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    • 제34권4호
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    • pp.315-321
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    • 2011
  • 본 연구는 검사 기법에 따른 영상의 질과 방사선 피폭의 정도를 제시하여 검사자가 받는 방사선 피폭을 저감시키는 데 목적이 있다. 관상동맥 전산화 단층 혈관조영(Coronary CTA, coronary computed tomography angiography) 검사자를 대상으로 SnapShot Pulse의 전향적 동조화 기법과 SnapShot Segment의 후향적 동조화 기법으로 coronary CTA 검사에서 검사자가 받는 단면 피폭선량(CTDIvol, volume computed tomography dose index), 총 피폭선량(dose-length product; DLP)을 각각 측정하였다. 또한, Coronary CTA 촬영조건을 동일하게 팬텀을 이용하여 CT감약계수, 노이즈 및 균일도, 공간분해능을 측정하였다. 연구 결과 두기법에서 CT감약계수, 노이즈 및 균일도, 공간분해능의 질적 수준이 비슷하게 나타났으며, CTDIvol, DLP는 SnapShot Segment의 후향적 동조화 기법에 비해 피폭선량이 약 37.5%, 40.3% 감소되었다. 임상에서 coronary CTA 검사 시 SnapShot Pulse의 전향적 동조화 기법을 적극 채택하여 검사자가 받는 방사선 피폭을 감소시키기 위한 노력이 절실히 요구된다.

몇 가지 PBTs (Persistent, Bioaccumulative, Toxic Chemicals)가 생태계 곤충에 미치는 영향

  • 이선영;김용균
    • 한국환경생물학회:학술대회논문집
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    • 한국환경생물학회 2002년도 학술대회
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    • pp.123-126
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    • 2002
  • Pollutants that are persistent, bioaccurnulative, and toxic have been linked to numerous adverse effects in human and animals, PBTs include heavy metals, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic compounds (PACs) in addition to pesticides. This study focuses on toxic effects of the PBTs except pesticides on insects. Eight PBTs were selected from subgroups: three heavy metals (Pb, Hg, and Cd), two PCB mixtures (Aroclor mixtures 1 and 2), 2,3,7,8-tetrachlorodibenzo-p-dioxin, two monophenols (4-octylphenol and 4-nonylphenol), and tetrabutyltin, Beet armyworm, Spodoptera exigua, was used as test target insect species. Three physiological markers (metamorphosis, immune reaction, and follicle patency) were assessed in each exposure to different doses of the PCBs. Heat-shock proteins as molecular markers were also analyzed in response to the PCBs. All tested PBTs were toxic to metamorphosis from larvae to pupae when they were applied with diet. Two PCB mixtures were the most toxic compounds in this assay by giving significant toxicity at 0.005 ppm, while others had from 10 to 1000 ppm. Dioxin (0.1 ppb), tetrabutyltin (0.1 ppb), Pb (10 ppb), and Hg (0,01 ppb) were potent to inhibit immune reactions analyzed by inducing phenoloxidase activity and blocked phospholipase $A_2$ enzyme, Tetrabutyltin and dioxin significantly induced follicle cell patency, but their effects were lower than that of endogenous juvenile hormone, Dioxin, Pb, Hg, and Cd could induce the expression of heat shock proteins that were detected by immunoblotting against human HSP70 monoclonal antibody. HSP78 and HSP80 were upregulated in response to the PBTs. This expression was detected from the fat body and epidermis at as fast as 4h after injection. All these results clearly suggest that PBTs give significant ecotoxicity to insects that are valuable organisms in our environment.

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A MODEL FOR PROTECTIVE BEHAVIOR AGAINST THE HARMFUL EFFECTS OF RADIATION FOR RADIOLOGICAL TECHNOLOGISTS IN MEDICAL CENTERS

  • Han, Eun-Ok;Moon, In-Ok
    • Journal of Radiation Protection and Research
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    • 제34권3호
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    • pp.95-101
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    • 2009
  • Protective behavior of radiological technologists against radiation exposure is important to achieve reduction of the patient doses without compromising medical achievements. This study attempts to provide a basic model for the sophisticated intervention strategy that increases the level of the protective behavior of the technologists. The model was applied to real situations in Korea to demonstrate its utility. The results of this study are summarized as follows: First, the protective environment showed the highest relationship in the factors considered, r=0.637 (p<0.01). Secondly, the important factors were protective environment in environment characteristics, expectation for the protective behavior 0.228 (p<0.001), self-efficacy 0.142 (p<0.001), and attitude for the protective behavior 0.178 (p<0.001) in personal characteristics, and daily patient -0.112 (p<0.001) and number of the participation in the education session for the protective behavior 0.074 (p<0.05). Thirdly, the final protective behavior model by a path analysis method had direct influence on the attitude 0.171 (p<0.01) and environment 0.405 (p<0.01) for the protective behavior, self efficacy 0.122 (p<0.01), expectation for the protective behavior 0.16 (p<0.01), and self-efficacy in the specialty of projects 0.154 (p<0.01). The acceptance of the model determined by the absolute fit index (GFI), 0.969, and by the incremental fit index (CFI), 0.943, showed very significant levels. Value of $x^2$/df that is a factor applied to verify the acceptance of the model was 37, which implies that the result can be accepted in the desirable range. In addition, the parsimonious fit index configured by AGFI (0.890) and TLI (0.852) was also considered as a scale that accepts the model in practical applications. In case of the establishment of some specific intervention strategies based on the protective behavior model against harmful radiation effects proposed in this study, the strategy will provide an effective way to prevent medical harmful radiation effects that could cause severe injuries to people.

치과방사선검사에서 방사선방어용구 사용 전, 후의 유효선량에 대한 평가 (Evaluation of effective dose in panorama, cone beam CT and the usefulness of x-ray protective)

  • 김재인;최원근;이소라;이정화;이관섭
    • 대한디지털의료영상학회논문지
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    • 제14권2호
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    • pp.15-22
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    • 2012
  • The purpose of this study was to measure the absorbed dose and calculate the effective dose for cone beam computed tomography (CBCT) and panorama units and to estimate usefulness of x-ray protective. Rando phantom and glass dosimeters were used for dosimetry. The absorbed doses were measured at 15 organs and 14 remainder from correspond to ICRP 2007 recommendations. The absorbed dose was highest in salivary glands as measured CBCT 2.420mGy, panorama 0.307mGy. Absorbed dose in another organs were high in order of thyroid, brain, skin, esophagus. The effective dose was CBCT 0.100mSv, panorama 0.011mSv and effective dose of panorama was higher than that of CBCT by 10 times. In case of wearing x-ray protective, reducing effective dose of CBCT by 0.066mSv (66%) and panorama by 0.008mSv (72%). Effective dose were reduced by radiological shielding but it needs further optimization studies, where dosimetric data are analyzed in combination with image quality with keep the patients' exposure as low as possible.

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