[Spatial distribution pattern of local tumor progression analysis after microwave ablation of hepatocellular carcinoma based on three-dimensional magnetic resonance imaging].

Objective: To investigate the spatial distribution pattern of local tumor progression (LTP) for hepatocellular carcinoma (HCC) ≤5 cm after microwave ablation. Methods: A retrospective analysis was performed on 169 HCCs with matched MRI before and after ablation from December 2009 to December 2019. A tumor MRI was reconstructed using three-dimensional visualization technology. LTP was classified as contact or non-contact, early or late stage, according to whether LTP was in contact with the edge of the ablation zone and the occurrence time (24 months). The tumor-surrounded area was divided into eight quadrants by using the eight-quadrant map method. An analysis was conducted on the spatial correlation between the quadrant where the ablative margin (AM) safety boundary was located and the quadrant where different types of LTP occurred. The t-test, or rank-sum test, was used for the measurement data. 2-test for count data was used to compare the difference between the two groups. Results: The AM quadrant had a distribution of 54.4% LTP, 64.2% early LTP stage, and 69.1% contact LTP, suggesting this quadrant was much more concentrated than the other quadrants (P < 0.001). Additionally, the AM quadrant had only 15.2% of non-contact type LTP and 17.1% of late LTP, which was not significantly different from the average distribution probability of 12.5% (100/8%) among the eight quadrants (P = 0.667, 0.743). 46.6% of early contact type LTP was located at the ablation needle tip, 25.2% at the body, and 28.1% at the caudal, while the location distribution probabilities of non-early contact LTP were 34.8%, 31.8%, and 33.3%, respectively. Conclusion: LTP mostly occurs in areas where the ablation safety boundary is the shortest. However, non-contact LTP and late LTP stages exhibit the feature of uniform distribution. Thus, this type of LPT may result from an inadequate non-ablation safety boundary.

Dose estimation by chromosome aberration analysis and micronucleus assays in victims accidentally exposed to (60)Co radiation.

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.

[The observation on the disinfecting efficiency of the disinfectant 93].

Disinfectant 93 is a colorless and transparent liquid. It contains surfactant and hand-protective. Its major component is Di(octyl amino-ethyl) glycine hydrochloride. 99.8% natural bacteria could be removed from the medical staff's hands by using the disinfectant 93 to scrub for 1 min twice. According to the standard of the Ministry of Public Health, it is allowed that the amount of bacteria on the hands is less than equal to 10cfu/cm2 under the condition of class III, and less than equal to 5cfu/cm2 under the condition of class I [symbol: see text] II, in which the qualification rate reached to 100% and 98%, respectively. The average elimination rate of natural bacteria reached to 99.5% and 99.3%, when the hands of surgical operators were disinfected with the disinfectant 93 after scrubbing and brushing with soap. The results showed that disinfecting efficiency of the disinfectant 93 was stronger, its continued effects were also visible, and it wasn't irritative for skin.

Hepatitis C antibodies in patients on peritoneal dialysis: prevalence and risk factors.

Our objective was to determine the prevalence of the antibody to hepatitis C (anti-HCV) in a population of end-stage renal failure patients on continuous peritoneal dialysis (CPD) and study the possible risk factors associated with anti-HCV seropositivity and seroconversion. A cross-sectional study included 155 adult patients enrolled in the CPD program in a single renal unit of a teaching hospital who were screened for anti-HCV by second-generation enzyme immunoassay, which was confirmed by recombinant immunoblot assay. Serum was also assayed for hepatitis B surface antigen (HBsAg). History of renal transplantation, blood transfusions, and exposure to hemodialysis was obtained from medical records. Ten of 155 patients (6.5%) in this study population were anti-HCV positive [anti-HCV(+)] and 11/155 (7.1%) were HBsAg positive; no patient was positive for both. All the anti-HCV(+) patients were on continuous ambulatory peritoneal dialysis (CAPD); no continuous cycling peritoneal dialysis (CCPD) patient was anti-HCV(+). Exposure to hemodialysis was a risk factor for anti-HCV seropositivity, with 7 out of 10 (70%) anti-HCV(+) patients having been on hemodialysis compared to 55/134 (41%) anti-HCV(-) (p < 0.05, Fisher's exact test). No difference was noted between anti-HCV(+) and anti-HCV(-) groups in relation to age, gender, duration on CPD, renal transplantation, or exposure to blood transfusions. Seroconversion occurred in only one patient after a mean observation period of 20 +/- 0.6 months. The prevalence of anti-HCV seropositivity in this population of CPD patients is 6.5%, and HBsAG 7.1%. Exposure to hemodialysis is a significant risk factor for development of anti-HCV seropositivity. Seroconversion rate appears to be low.