1.Evaluation of imaging performance of major image guidance systems
Chan MF* ; Yang J ; Song Y ; Burman C ; Chan P ; Li S
Biomedical Imaging and Intervention Journal 2011;7(2):1-7
Purpose: The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in
image-guided radiation therapy (IGRT) were evaluated.
Materials and methods: The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and
Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image
quality including image noise, uniformity, density accuracy, spatial resolution, contrast linearity, and contrast resolution.
The measurement results were analysed using in-house image analysis software. Reproducibility, position correction,
and geometric accuracy were also evaluated with markers in a smaller alignment phantom. The performance evaluation
compared volumetric image properties from these four systems with those from a conventional diagnostic CT (CCT).
Results: It was shown that the linearity of the two kV CBCT was fairly consistent with CCT. The Elekta CBCT
with half-circle 27-cm FOV had higher CT numbers than the other three systems. The image noises of the Elekta kV
CBCT, Siemens MV CBCT, and Tomotherapy fan-beam CT (FBCT) are about 2-4 times higher than that of the Varian
CBCT. The spatial resolutions of two kV CBCTs and two MV CBCTs were 8-11 lp/cm and 3-5 lp/cm, respectively.
Conclusion: Elekta CBCT provided a faster image reconstruction and low dose per scan for half-circle scanning.
Varian CBCT had relatively lower image noise. Tomotherapy FBCT had the best uniformity.
2.Application of denaturing high performance liquid chromatography to mutation detection of the c-kit gene in mastocytosis.
Ling-Yan ZHANG ; Gong-Li XU ; Nicholas C P CROSS
Journal of Experimental Hematology 2006;14(5):981-984
The aim of study was to detect mutation of tyrosine domain of c-kit gene in mastocytosis using denaturing high performance liquid chromatography technique, and to investigate the significance of this gene mutation in diagnosis and therapy of mastocytosis. Genomic DNA was obtained from bone marrow or peripheral blood leukocytes using the phenol/chloroform method from 7 mastocytosis patients. PCR was performed with AmpliTaq Gold DNA polymerase and 100 ng genomic DNA to amplify the entire coding sequence and exon-intron boundaries of c-kit exon 17 approximately exon 19. Denaturing high-performance liquid chromatography (DHPLC) analysis was performed on a WAVE DNA Fragment Analysis System. Each PCR product was mixed with an equal quantity of amplified human placental DNA (served as normal control) and was denatured at 95 degrees C for 5 minutes, followed by slowly cooling down to room temperature by 1.5 degrees C per minute to allow heteroduplexes formation. All the conditions for the DHPLC analysis, including melting temperature and buffer gradients were determined using the Transgenomic software Navigator. Samples with extra peaks or with different peak form on DHPLC were directly sequenced using the BigDye Terminator Cycle Sequencing Reaction kit and ABI 3100 Genetics Analyser. The results showed that DHPLC revealed an aberrant peak in one patient in exon 17 and the D816V mutation was identified by direct sequencing. The other two patients had an extra peak for exon 18/19 and direct sequencing revealed a conservative sequence change (L862L) within exon 18. It is concluded that denaturing high performance liquid chromatography is a high efficiency and reliable technique for mutation detection of c-kit gene and the detection results would be helpful for the selection of therapy in mastocytosis.
Adult
;
Aged
;
Base Sequence
;
Chromatography, High Pressure Liquid
;
methods
;
Chromosomes, Human, Pair 4
;
genetics
;
Humans
;
Mastocytosis
;
genetics
;
Middle Aged
;
Molecular Sequence Data
;
Mutation
;
genetics
;
Proto-Oncogene Proteins c-kit
;
genetics
3.Demographics, Usage Patterns, and Safety of Male Users of Clomiphene in the United States
David P GUO ; Dimitar V ZLATEV ; Shufeng LI ; Laurence C BAKER ; Michael L EISENBERG
The World Journal of Men's Health 2020;38(2):220-225
PURPOSE: The aim of this study was to characterize the demographics, usage patterns and complication rates of clomiphene use in male patients.MATERIALS AND METHODS: We retrospectively analyzed male patients from ages 20 to 55 years old who were prescribed clomiphene citrate from 2001 to 2014 using the Truven Health MarketScan, a US claims database. We collected data regarding associated medical diagnoses, diagnostic testing, duration of use, and reported side effects including thrombotic events, vision problems, gynecomastia, mental disorders, liver disease, nausea, or skin problems.RESULTS: In total, 12,318 men took clomiphene and represented the primary study cohort, with a mean age of 37.8 years. The percentage of men prescribed clomiphene increased over the study period, as did the average age of clomiphene users. Associated diagnoses included male infertility (52.0%), testicular hypofunction (13.5%), erectile dysfunction (2.4%), and low libido (0.4%). Associated testing included semen analysis (43.7%), testosterone (23.5%), luteinizing hormone (19.3%), and follicle-stimulating hormone (21.1%) levels. The median time of clomiphene use was 3.6 months, with 63% of men stopping within 6 months. No increased risk of reported clomiphene side effects were apparent in men taking the medication.CONCLUSIONS: There is a rising prevalence of clomiphene usage without associated adverse side effects in the US. The variability in associated diagnoses, diagnostic testing, and duration of use suggest a need for greater awareness of the proper evaluation and treatment of the men who are prescribed clomiphene.
4.Advances in the management of diabetic kidney disease: beyond sodium-glucose co-transporter 2 inhibitors
Anthony T. P. CHAN ; Sydney C. W. TANG
Kidney Research and Clinical Practice 2022;41(6):682-698
Progress in the treatment of diabetic kidney disease (DKD) has been modest since the early trials on renin-angiotensin-aldosterone system inhibitors (RAASis). Although sodium-glucose co-transporter 2 inhibitors (SGLT2is) have revolutionized the management of DKD by lowering proteinuria and protecting organs, other novel treatment approaches with good evidence and efficacy that can be used in conjunction with a RAASi or SGLT2i in managing DKD have emerged in the past few years. This review discusses the evidence for glucagon-like peptide-1 receptor agonist, selective mineralocorticoid receptor antagonist, and selective endothelin A receptor antagonist, emerging treatment options for DKD beyond SGLT2 inhibition.
5.Validation of the Paediatric Hearing Impairment Caregiver Experience (PHICE) Questionnaire.
Lynne H Y LIM ; Ling XIANG ; Naomi L Y WONG ; Kevin C P YUEN ; Ruijie LI
Annals of the Academy of Medicine, Singapore 2014;43(7):362-370
<p>INTRODUCTIONThe paediatric hearing impairment caregiver experience (PHICE) questionnaire is a 68-item instrument that assesses the stress experienced by caregivers of children with hearing impairment (HI). While the questionnaire has been validated in the United States, it may need to be modified for use in the Singapore context due to the differing healthcare system, costing and culture related to caregiving for children with HI. This study aims to modify and validate the PHICE questionnaire to increase its relevance and ease of use in Singapore.p><p>MATERIALS AND METHODSThe original PHICE questionnaire was filled out by 127 caregivers of HI children managed at the otolaryngology clinic of the National University Hospital (NUH). An expert panel was convened to assess the questionnaire for its suitability for use in Singapore. Exploratory factor analysis was conducted to evaluate the underlying factor structure of the original PHICE questionnaire. Items with high cross-loadings were removed and a new factor structure was adopted which was further analysed using confirmatory factor analysis (CFA). Cronbach's alpha (α) was computed to determine the internal consistency of the new subscales.p><p>RESULTSItems that are less relevant in Singapore and those with high cross-loadings were removed. A 5-factor structure with only 42 items remaining and corresponding to the factors: " Policy", "Healthcare", "Education", "Support" and "Adaptation" was adopted. CFA suggests a good model fit for the modified questionnaire, improved from the 8-factor structure of the original PHICE. Cronbach's α were high (>0.7) for each new subscale.p><p>CONCLUSIONThe original PHICE questionnaire has been shortened and reorganised in terms of the subscales composition. The resulting instrument is structurally valid and internally consistent. It is a simple and useful tool for identifying factors related to caregiving that can negatively impact rehabilitation outcomes for children with HI in Singapore. Removal of some sign language items makes this modified version less useful for caregivers, places or countries where sign language is the main focus of rehabilitation for children with HI.p>
Adolescent
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Caregivers
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Child
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Child, Preschool
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Female
;
Hearing Loss
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therapy
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Humans
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Infant
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Infant, Newborn
;
Male
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Singapore
;
Surveys and Questionnaires
6.Progress in assessment of vaccine on herd protection.
Chinese Journal of Epidemiology 2018;39(6):862-866
The importance of vaccine on public health is related to the herd protection related to the levels of vaccine coverage, which directly influences the vaccinated individuals as well as the unvaccinated community. Reaching the level of herd protection by increasing vaccine coverage is the basic strategy to eradicate related infectious diseases. Again, herd protection has played an important role in public health practices. With the increasing interests in estimating the vaccine herd protection, we however, have seen only few relevant papers including observational population-based and cluster-randomized clinical trials reported in China. We hope to discuss the study designs for evaluating the vaccine herd protection in order to generate evidence-based related research in this field.
China/epidemiology*
;
Communicable Disease Control
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Communicable Diseases/immunology*
;
Humans
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Immunity, Herd/immunology*
;
Research Design
;
Vaccination/trends*
;
Vaccines/immunology*
7.Disease burden of animal injury in China, 1990-2016.
P P YE ; Y JIN ; C R JI ; Y L ER ; L L DUAN ; Z X LI
Chinese Journal of Epidemiology 2019;40(1):52-58
Objective: To analyze the disease burden of animal injury in China between 1990 and 2016. Methods: Data obtained from the Global Burden of Disease 2016 were used to analyze the age and gender specific disease burden of animal injury in China, using the incidence and disability adjusted of life years (DALYs) rate. Relative and annual changes were evaluated. Results: In 2016, the age-standardized incidence and DALYs rate of animal injury in China showed as 245.05 per 100 000 people and 12.73 per 100 000. The age-standardized incidence of non-venomous animal injury was significantly higher than that of venomous animal injury, but the differences in age-standardized incidence and DALYs rate between venomous animal injury and non-venomous animal injury were not significant. Between 1990 and 2016, there was a significantly decreasing trend in the age-standardized incidence and DALYs rate of animal injury, and obvious decline could be seen in the incidence of non-venomous animal injury, compared with venomous animal injury. The incidence and DALYs rate of animal injury declined in both males and females and in different age groups. The obvious decline of incidence and DALYs rate could be found in children aged 5-14 years and aged <5 years. Conclusions: Between 1990 and 2016, there was a significant alleviation of the disease burden of animal injury in China. Young children were most prone to animal injury, resulting in serious disability and death, indicating more attention should be paid to this population at high risk and in animal injury prevention and control programs.
Adolescent
;
Child
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Child, Preschool
;
China/epidemiology*
;
Cost of Illness
;
Disabled Persons/statistics & numerical data*
;
Female
;
Global Burden of Disease
;
Humans
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Incidence
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Male
;
Quality-Adjusted Life Years
;
Wounds and Injuries/epidemiology*
8.Experimental study on high-frequency subharmonic scattering characteristics of ultrasound contrast agent microbubbles under low ambient pressure.
Huimin LU ; Yun WANG ; Laixin HUANG ; Gang XU ; Juan ZHOU ; Wenkui YU ; Fei LI
Journal of Biomedical Engineering 2023;40(6):1209-1216
Correlation between nonlinear subharmonic scattering of ultrasound contrast agent microbubbles and ambient pressure is expected to be used for local brain tissue pressure monitoring. Although high-frequency ultrasound has achieved high-resolution imaging of intracranial microvessels, the research on high-frequency subharmonic scattering characteristics of microbubbles is insufficient at present, which restricts the research progress of estimating local brain tissue pressure based on high-frequency subharmonic scattering of microbubbles. Therefore, under the excitation of 10 MHz high-frequency ultrasound, the effects of different acoustic pressures and ambient pressures on the high-frequency subharmonic scattering characteristics of three different ultrasound contrast agents including SonoVue, Sonazoid and Huashengxian were investigated in this in vitro study. Results showed that the subharmonic scattering amplitudes of the three microbubbles increased with the increase of ambient pressure at the peak negative acoustic pressures of 696, 766 and 817 kPa, and there was a favorable linear correlation between subharmonic amplitude and ambient pressure. Under the above three acoustic pressures, the highest correlation coefficient of SonoVue was 0.948 ( P = 0.03), the highest sensitivity of pressure measurement was 0.248 dB/mm Hg and the minimum root mean square error (RMSE) was 2.64 mm Hg. Sonazoid's highest correlation coefficient was 0.982 ( P < 0.01), the highest sensitivity of pressure measurement was 0.052 dB/mm Hg and the minimum RMSE was 1.51 mm Hg. The highest correlation coefficient of Huashengxian was 0.969 ( P = 0.02), the highest sensitivity of pressure measurement was 0.098 dB/mm Hg and the minimum RMSE was 2.00 mm Hg. The above in vitro experimental results indicate that by selecting ultrasound contrast agent microbubbles and optimizing acoustic pressure, the correlation between high-frequency subharmonic scattering of microbubbles and ambient pressure can be improved, the sensitivity of pressure measurement can be upgraded, and the measurement error can be reduced to meet the clinical demand for local brain tissue pressure measurement, which provided an important experimental basis for subsequent research in vivo.
Contrast Media
;
Microbubbles
;
Ultrasonography/methods*
9.Sixty-four cases of percutaneous coronary angioplasty on saphenous vein bypass grafts.
Zhi-zhong LI ; L SIDNEY ; C P JUERGENS ; Xiao-ling ZHU ; Ying TAO ; Tong LIU ; Su WANG ; Yong LI
Chinese Journal of Cardiology 2005;33(3):221-223
<p>OBJECTIVETo evaluate the early clinical result of percutaneous transluminal coronary intervention (PCI) and stenting on saphenous vein grafts.p><p>METHODSPercutaneous intervention was performed in 91 saphenous vein grafts in 64 patients. The data of clinical results during operation and hospitalization and that of other interventional assisting device were recorded in database and were analyzed.p><p>RESULTSThe success rate of operation was 95.3%, non-Q wave myocardial infarction occurred in 1 patient (1.6%) and temporary no-reflow phenomenon occurred in 4 patients (6.3%) during operation. Reduced antegrade flow and ventricular fibrillation happened in 1 patient after stenting and normal antegrade flow obtained after cardiac compression and tracheal intubation and insertion of IABP. The distal protection devices were used in 7 patients (10.9%), X-sizer extraction system in 4 patients. Platelet glycoprotein IIb/IIIa receptor blockers were administered in 25 patients (35.9%). Non-Q wave myocardial infarction occurred in two cases, the incidence of major adverse clinical event was 3.1% during the period of hospitalization.p><p>CONCLUSIONSThe instant success rate of PTCA and stenting of saphenous vein bypass grafts is high and recent clinical result is promising, but the middle and long term results remain to be further followed. The use of distal embolic protection device and GPIIb/IIIa receptor blockers may improve its prognosis.p>
Aged
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Angioplasty, Balloon, Coronary
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Coronary Artery Bypass
;
Graft Occlusion, Vascular
;
surgery
;
Humans
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Male
;
Middle Aged
;
Platelet Glycoprotein GPIIb-IIIa Complex
;
antagonists & inhibitors
;
Saphenous Vein
;
surgery
;
Treatment Outcome
10.Primary experimental results of methylseleninic acid on the proliferation inhibition and apoptotic induction in human high-metastatic large cell lung cancer cell line L9981.
Jiewei LIU ; Xiaorong ZHONG ; Qinghua ZHOU ; Allen C GAO ; Yanping WANG ; Wen ZHU ; Li MA ; Zhixuan ZHANG
Chinese Journal of Lung Cancer 2006;9(2):103-108
<p>BACKGROUNDIt has been proved that selenium has remarkable effects in the prevention of cancer and proliferation inhibition for breast cancer and prostate cancer. Up to now, little is known, however, if methylseleninic acid (MSA) has the anticancer effect on lung cancer or not. The objective of this study is to detect the effect of MSA on proliferation inhibition and apoptotic induction for human high-metastatic large cell lung cancer cell line L9981, and to explore the molecular mechanisms.p><p>METHODSThe changes of proliferation, clone formation, apoptotic level and cell cycles were detected in L9981 by trypan blue staining, clone formation suppression test, and flow cytometry before and after treating with different concentration of MSA. The expression level of proliferative-related and apoptotic-related genes was also determined in L9981 by flow cytometry.p><p>RESULTS(1)The proliferation ability of L9981 was remarkably inhibited at the concentration of 0.5μmol/L of MSA (P < 0.05), and the cells were arrested at G0/G1 phase after treating with the same concentration. (2)Apoptosis of L9981 was remarkably induced by MSA at the concentration of 2.5μmol/L (P < 0.05). (3)The clone formation ability of L9981 was significantly suppressed by MSA at the concentration of 5.0μmol/L (P < 0.05). (4)The expression levels of P53, P21, Fas, FasL and Bax were remarkably up-regulated after treatment with MSA.p><p>CONCLUSIONS(1)MSA can significantly suppress the proliferation and clone formation ability of human high-metastatic large cell lung cancer cell line L9981, and also induce apoptosis of L9981. (2)The anticancer effects of MSA might be related to regulate the expression of cell cycle-related genes and apoptotic-related genes in the human high-metastatic large cell lung cancer line L9981.p>