1.Quality assurance of TomoDirect treatment plans using I’mRT MatriXX
Kong CW ; Yu SK ; Cheung KY ; Geng H ; Ho YW ; Lam WW ; Wong WK
Biomedical Imaging and Intervention Journal 2012;8(2):1-7
Purpose: To evaluate the performance of 2D-array I’mRT MatriXX for dose verification of TomoDirect treatment
plans.
Methods: In this study, a 2D-array ion chamber device – the I’mRT MatriXX and Multicube Phantom from IBA –
was used for dose verification of different TomoDirect plans. Pre-treatment megavoltage computed tomography (MVCT)
was performed on the phantom setup for position correction. After the irradiation of treatment plans on the I’mRT MatriXX and Multicube Phantom, the measured doses of coronal planes were compared with those from the planning calculations for verification. The results were evaluated by comparing the absolute dose difference in the high dose region as well as the gamma analysis of the 2D-dose distributions on the coronal plane. The comparison was then repeated with the measured dose corrected for angular dependence of the MatriXX.
Results: When angular dependence is taken into account, the passing rate of gamma analysis is over 90% for all
measurements using the MatriXX. If there is no angular dependence correction, the passing rate of gamma analysis
worsens for treatment plans with dose contribution from the rear. The passing rate can be as low as 53.55% in extreme cases, i.e. where all doses in the treatment plan are delivered from the rear.
Conclusion: It is important to correct the measured dose for angular dependence when verifying TomoDirect
treatment plans using the MatriXX. If left uncorrected, a large dose discrepancy may be introduced to the verification results.
2.Cell death of intestinal epithelial cells in intestinal diseases.
Saravanan SUBRAMANIAN ; Hua GENG ; Xiao-Di TAN
Acta Physiologica Sinica 2020;72(3):308-324
Gut injury continues to be the devastating and unpredictable critical illness associated with increased cell death of intestinal epithelial cells (IECs). The IECs, immune system and microbiome are the interrelated entities to maintain normal intestinal homeostasis and barrier integrity. In response to microbial invasion, IEC cell death occurs to maintain intestinal epithelium function and retain the continuous renewal and tissue homeostasis. But the imbalance of IEC cell death results in increased intestinal permeability and barrier dysfunction that leads to several acute and chronic intestinal diseases, such as intestinal ischemia/reperfusion (I/R), sepsis, inflammatory bowel diseases (IBD), necrotizing enterocolitis (NEC), etc. During the pathophysiological state, the excessive IEC apoptotic cell death leads to a chronic inflammatory condition, later switches to necroptotic cell death mechanism that induces more pathological features than apoptosis and may also induce other lytic cell death mechanisms like pyroptosis and ferroptosis to increase the pathogenesis of the intestinal diseases. But still, there remains gaps in the fundamental knowledge about the IEC cell death mechanisms in chronic intestinal diseases. Together, a deep understanding of the specific cell death mechanisms underlying chronic intestinal diseases, including sepsis, IBD, NEC, and intestinal I/R, is desperately needed to develop emerging novel promising therapeutic strategies. This review aims to show how the acute and critical illness in the gut are driven by IEC cell death mechanism, such as apoptosis, necrosis, necroptosis, pyroptosis, and ferroptosis.
Apoptosis
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Cell Death
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Epithelial Cells
;
Humans
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Infant, Newborn
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Intestinal Mucosa
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Necrosis
3.Exploration of approaches to adjusting brand-name drug prices in Mainland of China: based on comparison and analysis of some brand-name drug prices of Mainland and Taiwan, China.
Geng WENG ; Sheng HAN ; Run PU ; Wynn H T PAN ; Luwen SHI ;
Chinese Medical Journal 2014;127(12):2222-2228
BACKGROUNDUnder the circumstance of the New Medical Reform in Mainland of China, lowering drug prices has become an approach to relieving increase of medical expenses, and lowering brand-name medication price is a key strategy. This study, by comparing and analyzing brand-name medication prices between Mainland of China and Taiwan, explores how to adjust brand-name medication prices in Mainland of China in the consideration of the drug administrative strategies in Taiwan.
METHODSBy selecting brand-name drug with generic name and dose types matched in Mainland and Taiwan, calculate the average unit price and standard deviation and test it with the paired t-test. In the mean time, drug administrative strategies between Mainland and Taiwan are also compared systematically.
RESULTSAmong the 70 brand-name medications with generic names and matched dose types, 54 are at higher prices in Mainland of China than Taiwan, which is statistically significant in t-test. Also, among the 47 medications with all of matched generic names, dose types, and manufacturing enterprises, 38 are at higher prices in Mainland than Taiwan, and the gap is also statistically significant in t-test. In Mainland of China, brand-name medication took cost-plus pricing and price-based price adjustment, while in Taiwan, brand-name medication took internal and external reference pricing and market-based price adjustment.
CONCLUSIONSBrand-name drug prices were higher in Mainland of China than in Taiwan. The adjustment strategies of drug prices are scientific in Taiwan and are worth reference by Mainland of China.
China ; Humans ; Nonprescription Drugs ; economics ; Pharmaceutical Preparations ; economics ; Taiwan
4.Survey on a norovirus-borne outbreak caused by GⅡ.4 Sydney 2012 variant in a university of Guangzhou, 2017.
M M MA ; H WANG ; J Y LU ; D H WANG ; Q ZENG ; J M GENG ; T G LI ; Z B ZHANG ; Z C YANG
Chinese Journal of Epidemiology 2018;39(12):1570-1575
Objective: To understand the epidemiological and molecular characteristics of a norovirus- borne outbreak caused by GⅡ.4 Sydney 2012 in a university of Guangzhou to provide evidence for the prevention and control strategy on norovirus-caused epidemics. Methods: A self-designed questionnaire was used to collect clinical information from the patients as well as other data related to the epidemic. Pathogen detections were performed through anal swab specimens from the patients, kitchen workers and samples from the environment. Positive samples were further sequenced for phylogenetic analysis. A case-control study was employed to identify the risk factors related to this outbreak. Results: A total of 226 cases of norovirus-borne infection were identified between September 17 and 21, 2017, including 223 students, with an attack rate of 0.73% (223/30 711), and 3 kitchen workers. Students staying in the A dormitory area had the highest attack rate (1.73%, 164/9 459). No clustering was found in different colleges or classes. Results from the case-control study revealed that people who ate at the canteen in A dormitory area during September 18 to 20 was at risk for the onset of illness (OR=10.75, 95%CI: 5.56-20.79). The highest risk was related to the dinner on September 18. Another significant risk factor (OR=3.65, 95%CI: 1.92-6.94) was close personal contact in the same room of the dorm. The 3 norovirus infected kitchen workers were all from the canteen in A dormitory area where the positive rate of norovirus identified in kitchen workers was 26.67% (12/45). Positive samples were sequenced and sub-typed with results showing that the GⅡ.4 Sydney 2012 variant and the nucleotide sequences of cases and kitchen workers were 100% identical. Conclusions: The outbreak was caused by norovirus GⅡ.4 Sydney 2012 variant at campus. Similar outbreaks had been seen since 2013, with the routes of transmission most likely due to food-borne or personal contact.
Adolescent
;
Adult
;
Caliciviridae Infections/epidemiology*
;
Case-Control Studies
;
China/epidemiology*
;
Disease Outbreaks
;
Female
;
Foodborne Diseases/virology*
;
Gastroenteritis/virology*
;
Humans
;
Male
;
Norovirus/isolation & purification*
;
Phylogeny
;
Surveys and Questionnaires
5.Surveillance data on notifiable infectious diseases among students aged 6-22 years in China, 2011-2016.
J SUN ; W W YANG ; L J ZENG ; M J GENG ; Y H DONG ; Y XING ; J MA ; Z J LI ; L P WANG
Chinese Journal of Epidemiology 2018;39(12):1589-1595
Objective: To analyze the epidemiological characteristics of notifiable infectious diseases among Chinese students from 2011 to 2016 and to provide reference for the effective prevention and control programs on infectious disease among students. Methods: Both morbidity and mortality of notifiable infectious diseases among Chinese students aged 6-22 years from 2011 to 2016 were analyzed, with main characteristics of the disease described. Results: During 2011 to 2016, morbidities of Categories A, B and C infectious diseases among the Chinese students aged 6-22 years showed a decreasing trend, from 248.24/100 000 in 2012 to 158.57/100 000 in 2016. Mortality rates of Category A, B and C infectious diseases had also decreased from 0.12/100 000 in 2011 to 0.07/100 000 in 2016. The average morbidity of the top four diseases from Category A and B infectious diseases appeared as: tuberculosis (16.24/100 000), scarlet fever (9.39/100 000), hepatitis B (7.69/100 000) and bacillary and amebic dysentery (7.15/100 000). The average rates of mortality on the top four diseases appeared as: rabies (0.044 8/100 000), HIV/AIDS (0.027 7/100 000), tuberculosis (0.008 0/100 000) and Japanese encephalitis (0.005 9/100 000). The average rates of morbidity on the top four diseases appeared as: mumps (75.81/100 000), hand-foot-mouth disease (28.55/100 000), other infectious diarrhea (22.41/100 000) and influenza (15.67/100 000) in the Category C. Reported death cases were from hand-foot-mouth disease (11 cases), influenza (9 cases), mumps (1 case) and rubella (1 case). The prevalence rates varied among different student populations, with higher HIV/AIDS, hepatitis B and tuberculosis rates among college and senior high school students, while higher mumps, influenza and hand-foot-mouth disease rates among primary school and junior high school students. Conclusions: Both morbidity and mortality of notifiable infectious diseases among Chinese students aged 6-22 years had decreased significantly in 2011-2016. However, the major infectious diseases had become new challenges among students. HIV/AIDS had become a key infectious disease among college students and the relatively high prevalence of tuberculosis was seen in college and high school students.
Adolescent
;
Child
;
China/epidemiology*
;
Communicable Diseases/epidemiology*
;
Disease Notification/statistics & numerical data*
;
Humans
;
Population Surveillance/methods*
;
Prevalence
;
Students/statistics & numerical data*
;
Young Adult