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The objective of this study was to assess the radiation exposure levels in victims of a 60Co radiation accident using chromosome aberration analysis and the micronucleus assay. Peripheral blood samples were collected from three victims exposed to 60Co 10 days after the accident and were used for the chromosome aberration and micronucleus assays. After in vitro culture of the lymphocytes, the frequencies of dicentric chromosomes and rings (dic+r) and the numbers of cytokinesis blocking micronuclei (CBMN) in the first mitotic division were determined and used to estimate radiation dosimetry. The Poisson distribution of the frequency of dic+r in lymphocytes was used to assess the uniformity of the exposure to 60Co radiation. Based on the frequency of dic+r in lymphocytes, estimates of radiation exposure of the three victims were 5.61 Gy (A), 2.48 Gy (B) and 2.68 Gy (C). The values were estimated based on the frequencies of CBMN, which were 5.45 Gy (A), 2.78 Gy (B) and 2.84 Gy (C). The estimated radiation dosimetry demonstrated a critical role in estimating the radiation dose and facilitating an accurate clinical diagnosis. Furthermore, the frequencies of dir+r in victims A and B deviated significantly froma normal Poisson distribution. Chromosome aberration analysis offers a reliable means for estimating biological exposure to radiation. In the present study, the micronucleus assay demonstrated a high correlation with the chromosome aberration analysis in determining the radiation dosimetry 10 days after radiation exposure. [ABSTRACT FROM AUTHOR]

Objective: To evaluate factors relevant to primary non-response in patients with Crohn's disease undergoing infliximab (IFX) treatment at week 14. Methods: Patients with Crohn's disease in the Third Hospital of Peking University who were subject to IFX treatment more than 3 times and followed-up for more than 14 weeks from October 2015 to October 2018 were reviewed. The response was defined by a decrease of ≥100 points from baseline in the Crohn's Disease Activity Index. The clinical data and laboratory examinations of the two groups were compared, and the treatment outcomes of non-responders were also followed up. Results: A total of 41 patients were enrolled, among which 27(65.9%) were male. The median age at treatment was 25 years, and 8 patients lost primary response (19.5%). There was no significant difference in the sex, age at diagnosis or treatment, Montreal disease type and laboratory examinations [C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), hemoglobin, albumin] in the response group and non-response group at baseline phase ( P> 0.05). Baseline CRP decreased from 17.7 (26.2) mg/L to 2.2 (3.6) mg/L in the response group, but increased from 11.7 (9.5) mg/L to 31.6 (28.4) mg/L in the non-response group at week 14 ( P= 0.024). The trend of ESR change in the response group [from 23.0 (28.5) mm/h to 7.0 (8.5) mm/h] and the non-response group [from 24.5 (22.5) mm/h to 35.0 (26.5) mm/h] was similar with that of CRP ( P= 0.036). Hemoglobin and albumin were significantly elevated in the response group, but not in the non-response group at week 14 ( P= 0.593, P= 0.255). Among the non-response patients, 5 were converted to responsive after the treatment protocols had been adjusted. The combined immunosuppressant treatment all obtained clinical response. Conclusions: The elevated CRP and/or ESR may serve as indicators of primary non-response (at week 14) to IFX treatment among Crohn's disease patients, and the combination of immunosuppressive agents may be one of the effective treatments after excluding infection and other causes.

The objective of this study was to assess the radiation exposure levels in victims of a (60)Co radiation accident using chromosome aberration analysis and the micronucleus assay. Peripheral blood samples were collected from three victims exposed to (60)Co 10 days after the accident and were used for the chromosome aberration and micronucleus assays. After in vitro culture of the lymphocytes, the frequencies of dicentric chromosomes and rings (dic+r) and the numbers of cytokinesis blocking micronuclei (CBMN) in the first mitotic division were determined and used to estimate radiation dosimetry. The Poisson distribution of the frequency of dic+r in lymphocytes was used to assess the uniformity of the exposure to (60)Co radiation. Based on the frequency of dic+r in lymphocytes, estimates of radiation exposure of the three victims were 5.61 Gy (A), 2.48 Gy (B) and 2.68 Gy (C). The values were estimated based on the frequencies of CBMN, which were 5.45 Gy (A), 2.78 Gy (B) and 2.84 Gy (C). The estimated radiation dosimetry demonstrated a critical role in estimating the radiation dose and facilitating an accurate clinical diagnosis. Furthermore, the frequencies of dir+r in victims A and B deviated significantly from a normal Poisson distribution. Chromosome aberration analysis offers a reliable means for estimating biological exposure to radiation. In the present study, the micronucleus assay demonstrated a high correlation with the chromosome aberration analysis in determining the radiation dosimetry 10 days after radiation exposure.

By means of single photon absorptiometry, bone material content (BMC) on centerbrachium was detected in 34 patients with chronic renal failure (CRF) and 34 sex-age-matched normal controls, and their serum parathyroid hormone (PTH), calcitonin (CT) were also measured by radioimmunoassay. It was found that (1) the mean BMC was obviously lower in patients with CRF than that in the normal controls; (2) PTH and CT obviously rose in patients with CRF; (3) the decrease of BMC was strongly correlated with that of creatinine clearance (Ccr). Furthermore, the more Ccr decreases, the more PTH in blood increases; no relations have been found between BMC and the serum levels of CT. The authors suggest that the development of osteoporosis with CRF is due to the secondary increase of PTH in blood but the effect of increased serum CT levels was not so obvious. Therefore, lowering blood PTH concentrations by parathyroidectomy or renal transplantation may be beneficial to curing osteoporosis of patients with CRF.