[Inhibitory effect of downregulating G protein-coupled receptor class C group 5 member A expression on lipopolysaccharide-induced inflammatory response in human gingival fibroblasts]

Objective: To clarify the effect and the mechanism of G protein-coupled receptor class C group 5 member A (GPRC5A) on lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (GFs), thus to provide a foundation for delving into the role of G protein coupled receptor (GPCR) in periodontitis. Methods: Gingival tissue samples were collected from 3 individuals periodontally healthy (health group) and 3 patients with periodontitis (periodontitis group) in Shandong Stomatological Hospital from December 2022 to February 2023. The expressions of GPRC5A of the two groups were detected by immunohistochemistry staining. GFs used in this study were isolated from a portion of gingiva for the extraction of impacted teeth in School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University from December 2022 to February 2023. GFs were isolated with enzymic digestion and transfected with 30, 50 and 80 μmol/L small interfering RNA-GPRC5A (siGPRC5A) or small interfering RNA-negative control (siNC), regarded as the experimental group and the negative control one, respectively. The silencing efficiency of siGPRC5A was evaluated by real-time fluorescence quantitative PCR (RT-qPCR). Experiments were then conducted using these cells which were divided into four groups of negative control (NC), LPS, siGPRC5A+LPS and siGPRC5A. The mRNA and protein levels of GPRC5A in GFs under 1 mg/L LPS-induced GFs inflammatory state were evaluated by RT-qPCR and Western blotting analysis after GPRC5A knockdown. RT-qPCR was used to detect the gene expression levels of the inflammatory cytokines in GFs induced by LPS, namely, interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, prostaglandin endoperoxide synthase 2 (PTGS2) after GPRC5A knockdown. Western blotting analysis and immunofluorescence staining were used to further investigate the activation of nuclear factor-kappa B (NF-κB) signaling pathway. Results: Immunohistochemistry staining showed that the expression of GPRC5A in gingival tissues of periodontitis group (0.132±0.006) increased compared with that in periodontally healthy group (0.036±0.019) (t=8.24, P=0.001). Meanwhile, RT-qPCR results showed that the gene expression levels of GPRC5A at different time point (2, 6, 12, 24 h) in LPS-induced GFs (0.026±0.002, 0.042±0.005, 0.004±0.000, 0.016±0.000) were upregulated compared with those in the NC group (0.004±0.000, 0.004±0.000, 0.002±0.000, 0.007±0.000) (all P<0.001), respectively, and peaked at 6 h. The 50 μmol/L group displayed the most significant decrease in siGPRC5A expression (31.16±3.29) compared with that of the siNC group (100.00±4.88) (F=297.98, P<0.001). The results of RT-qPCR and Western blotting analysis showed that siGPRC5A (0.27±0.03, 0.71±0.00) suppressed the expressions of GPRC5A at both gene and protein levels, while LPS (1.30±0.10, 1.43±0.03) was able to promote the expressions of GPRC5A compared with those of the NC group (1.00±0.01, 1.00±0.00)(all P<0.001). The siGPRC5A+LPS group (0.39±0.03, 1.06±0.16) also inhibited the increase of GPRC5A at both gene and protein levels induced by LPS (1.30±0.10, 1.43±0.03) (F=208.38, P<0.001; F=42.04, P<0.001). RT-qPCR results showed that the expressions of IL-8, IL-1β, IL-6, TNF-α, and PTGS2 at the gene level in LPS group were highly increased compared with those in the NC group (all P<0.001). siGPRC5A significantly suppressed LPS-induced expressions of these inflammatory cytokines in GFs (all P<0.001). Western blotting analysis showed that the levels of p65 and IκBα protein phosphorylation in the LPS group were highly increased compared with those in the NC group, and siGPRC5A could effectively suppressed LPS-induced protein phosphorylation (all P<0.01). Furthermore, immunofluorescence staining showed that NF-κB p65 in the control group was mainly concentrated in the cytoplasm, and partially translocated to the nucleus under the stimulation of LPS. siGPRC5A was able to inhibit LPS-induced intranuclear translocation of p65 to a certain extent. Conclusions: GPRC5A expression was upregulated in periodontitis, and GPRC5A knockdown inhibited LPS-induced inflammation. Moreover, GPRC5A played a role in inflammation regulation by interacting with NF-κB signaling pathway.

A kV-MV approach to CBCT metal artifact reduction using multi-layer MV-CBCT

Objective. To demonstrate that complete cone beam CT (CBCT) scans from both MV-energy and kV-energy LINAC sources can reduce metal artifacts in radiotherapy guidance, while maintaining standard-of-care x-ray doses levels.Approach. MV-CBCT and kV-CBCT scans are acquired at half normal dose. The impact of lowered dose on MV-CBCT data quality is mitigated by the use of a 4-layer MV-imager prototype and reduced LINAC energy settings (2.5 MV) to improve photon capture. Additionally, the MV-CBCT is used to determine the 3D position and pose of metal implants, which in turn is used to guide model-based poly-energetic correction and interleaving of the kV-CBCT and MV-CBCT data. Certain edge-preserving regularization steps incorporated into the model-based correction algorithm further reduce MV data noise.Main results. The method was tested in digital phantoms and a real pelvis phantom with large 2.5″ spherical inserts, emulating hip replacements of different materials. The proposed method demonstrated an appealing compromise between the high contrast of kV-CBCT and low artifact content of MV-CBCT. Contrast-to-noise improved 3-fold compared to MV-CBCT with a clinical 1-layer architecture at matched dose (37 mGy) and edge blur levels. Visual delineation of the bladder and prostate improved noteably over kV- or MV-CBCT alone.Significance. The proposed method demonstrates that a full MV-CBCT scan can be combined with kV-CBCT to reduce metal artifacts without resorting to complicated beam collimation strategies to limit the MV-CBCT dose contribution. Additionally, significant improvements in CNR can be achieved as compared to metal artifact reduction through current clinical MV-CBCT practices.

[Different methods in predicting mortality of pediatric intensive care units sepsis in Southwest China]

Objective: To investigate the value of systemic inflammatory response syndrome (SIRS), pediatric sequential organ failure assessment (pSOFA) and pediatric critical illness score (PCIS) in predicting mortality of pediatric sepsis in pediatric intensive care units (PICU) from Southwest China. Methods: This was a prospective multicenter observational study. A total of 447 children with sepsis admitted to 12 PICU in Southwest China from April 2022 to March 2023 were enrolled. Based on the prognosis, the patients were divided into survival group and non-survival group. The physiological parameters of SIRS, pSOFA and PCIS were recorded and scored within 24 h after PICU admission. The general clinical data and some laboratory results were recorded. The area under the curve (AUC) of the receiver operating characteristic curve was used to compare the predictive value of SIRS, pSOFA and PCIS in mortality of pediatric sepsis. Results: Amongst 447 children with sepsis, 260 patients were male and 187 patients were female, aged 2.5 (0.8, 7.0) years, 405 patients were in the survival group and 42 patients were in the non-survival group. 418 patients (93.5%) met the criteria of SIRS, and 440 patients (98.4%) met the criteria of pSOFA≥2. There was no significant difference in the number of items meeting the SIRS criteria between the survival group and the non-survival group (3(2, 4) vs. 3(3, 4) points, Z=1.30, P=0.192). The pSOFA score of the non-survival group was significantly higher than that of the survival group (9(6, 12) vs. 4(3, 7) points, Z=6.56, P<0.001), and the PCIS score was significantly lower than that of the survival group (72(68, 81) vs. 82(76, 88) points, Z=5.90, P<0.001). The predictive value of pSOFA (AUC=0.82) and PCIS (AUC=0.78) for sepsis mortality was significantly higher than that of SIRS (AUC=0.56) (Z=6.59, 4.23, both P<0.001). There was no significant difference between pSOFA and PCIS (Z=1.35, P=0.176). Platelet count, procalcitonin, lactic acid, albumin, creatinine, total bilirubin, activated partial thromboplastin time, prothrombin time and international normalized ratio were all able to predict mortality of sepsis to a certain degree (AUC=0.64, 0.68, 0.80, 0.64, 0.68, 0.60, 0.77, 0.75, 0.76, all P<0.05). Conclusion: Compared with SIRS, both pSOFA and PCIS had better predictive value in the mortality of pediatric sepsis in PICU.

MV-based relative electron density estimation (iMREDe) for MR-LINAC dose calculation

BACKGROUND

MR-LINAC systems have been increasingly utilized for real-time imaging in adaptive treatments worldwide. Challenges in MR representation of air cavities and subsequent estimation of electron density maps impede planning efficiency and may lead to dose calculation uncertainties.

PURPOSE

To demonstrate the generation of accurate electron density maps using the primary MV beam with a flat-panel imager.

METHODS

The ViewRay MRIdian MR-LINAC system was modeled digitally for Monte Carlo simulations. Iron shimming, the magnetic field, and the proposed flat panel detector were included in the model. The effect of the magnetic field on the detector response was investigated. Acquisition of projections over 360 degrees was simulated for digital phantoms of the Catphan 505 phantom and a patient treated for Head and Neck cancer. Shim patterns on the projections were removed and detector noise linearity was assessed. Electron density maps were generated for the digital patient phantom using the flat-panel detector and compared with actual treatment planning CT generated electron density maps of the same patient.

RESULTS

The effect of the magnetic field on the detector point-spread function (PSF) was found to be substantial for field strengths above 50 mT. Shims correction in the projection images using air normalization and in-painting effectively removed reconstruction artifacts without affecting noise linearity. The relative difference between reconstructed electron density maps from the proposed method and electron density maps generated from the treatment planning CT was 11% on average along all slices included in the iMREDe reconstruction.

CONCLUSIONS

The proposed iMREDe technique demonstrated the feasibility of generating accurate electron densities for the ViewRay MRIdian MR-LINAC system with a flat-panel imager and the primary MV beam. This work is a step towards reducing the time and effort required for adaptive radiotherapy in the current ViewRay MR-LINAC systems.

[Epidemiological characteristics of public health emergency events of varicella in China, 2006-2021]

Objective: To understand the epidemiological characteristics of public health emergency events (PHEE) of varicella in China from 2006 to 2021 and related response performances. Methods: The data of varicella PHEE in 31 provinces of China from 2006 to 2021 were collected through the Public Health Emergency Management Information System, Microsoft Excel 2019 software and SPSS 26.0 statistical software were used to conduct descriptive epidemiological, statistical analysis on the time, area, location distribution, scale and epidemic management. Results: A total of 11 443 PHEE involving 341 048 related cases were reported from 2006 to 2021, with an annual attack rate of 1.78%-3.80% and a total attack rate of 2.33% (341 048/14 624 042). The number of PHEE and related cases of varicella decreased from 1 107 (35 349) in 2007 to 262 (6 884) in 2012 (Z=-2.40, P<0.001), then increased year by year to 1 318 (42 649) in 2019 (Z=2.58, P<0.001), with a significant decline since 2020. The varicella PHEE in China presents the seasonal characteristics,the peak is from April to June and from October to December, respectively. The sub-peak of varicella PHEE in eastern China generally appears 1-2 months earlier than in central and western China. Varicella PHEE reports are mainly distributed in eastern China, the attack rate is relatively high in western China, school-reported varicella PHEE was 88.26% of the total reports (10 099/11 443). The epidemic scale of varrcella PHEE typically range from 10 to 29 cases per year among the given outbreaks. The M (Q1, Q3) of average number of cases, average duration, and average reporting interval of PHEE were 23 (16,35), 20 (14, 26) days, and 9 (5,19) days, respectively, and the reporting interval was positively correlated with the duration (r=0.854, P<0.001). Conclusions: The varicella PHEE in China from 2006 to 2021 has not been effectively controlled. Schools are the key places to prevent and control varicella PHEE. Improving the sensitivity of varicella PHEE monitoring, strengthening the timely disposal of varicella epidemic, and promoting varicella vaccination are effective measures to prevent and control varicella PHEE.

[Comparative analysis of seroepidemiological survey results of hepatitis B among people aged 1-69 years in Tibet Autonomous Region in 2014 and 2020]

Objective: To evaluate the effectiveness of hepatitis B prevention and control in Tibet Autonomous Region by comparative analysis of the results of seroepidemiological surveys of hepatitis B in 2014 and 2020. Methods: The required sample size was calculated based on the estimated HBsAg positivity rates of permanent residents aged 1-4, 5-14, 15-29, and 30-69 years. A total of 7 163 people and 4 802 people were required in 2014 and 2020, respectively. The subjects were selected by stratified multistage cluster random sampling method, using questionnaires to obtain basic information, and 5 ml of venous blood was collected from each subject to detect HBsAg, anti-HBs, and anti-HBc, and rechecked the HBsAg positive samples. SPSS 22.0 software was used to analyze the survey results, calculate the positive rate and 95% confidence interval. Results: A total of 7 069 people were investigated in 2014 and 4 913 people in 2020. In 2020, the positive rate of HBsAg, anti-HBs, and anti-HBc was 9.20% (452/4 913), 37.11% (1 823/4 913), and 32.75% (1 609/4 913), respectively, and decreased by 22.95%, 15.54%, and 1.92% as compared with the rate in 2014. The positive rate of HBsAg of people aged 1-, 5-, 15- and 30-69 years in 2020 was 2.23% (8/358), 2.85% (20/701), 6.86% (69/1 006) and 12.46%(355/2 848), respectively, decreased by 61.82%, 62.75%, 54.81% and 24.21% as compared with the rate in 2014. The positive rate of anti-HBs of people aged 1-4 years was 52.79% (189/358), 10.30% increased compared with 2014; for people aged 5-, 15-, and 30-69 years was 32.67% (229/701), 37.67% (379/1 006) and 36.03%(1 026/2 848), respectively, decreased by 20.84%, 14.13% and 16.52% as compared with the rate in 2014. The positive rate of anti-HBc of people aged 1-, 5-, 15-, 30-69 years was 4.19% (15/358), 6.42%(45/701), 21.07% (212/1 006), and 46.95% (1 337/2 848), respectively, decreased by 59.63%, 58.93%, 50.49%, and 12.10% as compared with the rate in 2014. Conclusions: The prevention and control of hepatitis B in Tibet have made partial achievements. The prevalence of HBsAg among people aged 1-69 years in 2020 had declined compared with 2014, but it is still at a high epidemic level. People have a high risk of HBV infection for a low level of anti-HBs. It is necessary to strengthen the vaccination of hepatitis B further and effectively implement the strategy of blocking mothers and children of the hepatitis B virus.

Monte Carlo model of a prototype flat-panel detector for multi-energy applications in radiotherapy

BACKGROUND

The incorporation of multi-energy capabilities into radiotherapy flat-panel detectors offers advantages including enhanced soft tissue visualization by reduction of signal from overlapping anatomy such as bone in 2D image projections; creation of virtual monoenergetic images for 3D contrast enhancement, metal artefact reduction and direct acquisition of relative electron density. A novel dual-layer on-board imager offering dual energy processing capabilities is being designed. As opposed to other dual-energy implementation techniques which require separate acquisition with two different x-ray spectra, the dual-layer detector design enables simultaneous acquisition of high and low energy images with a single exposure. A computational framework is required to optimize the design parameters and evaluate detector performance for specific clinical applications.

PURPOSE

In this study, we report on the development of a Monte Carlo (MC) model of the imager including model validation.

METHODS

The stack-up of the dual-layer imager (DLI) was implemented in GEANT4 Application for Tomographic Emission (GATE). The DLI model has an active area of 43×43 cm2 , with top and bottom Cesium Iodide (CsI) scintillators of 600 and 800 μm thickness, respectively. Measurement of spatial resolution and imaging of dedicated multi-material dual-energy (DE) phantoms were used to validate the model. The modulation transfer function (MTF) of the detector was calculated for a 120 kVp x-ray spectrum using a 0.5 mm thick tantalum edge rotated by 2.5o . For imaging validation, the DE phantom was imaged using a 140 kVp x-ray spectrum. For both validation simulations, corresponding measurements were done using an initial prototype of the imager. Agreement between simulations and measurement was assessed using normalized root mean square error (NRMSE) and 1D profile difference for the MTF and phantom images respectively. Further comparison between measurement and simulation was made using virtual monoenergetic images (VMIs) generated from basis material images derived using precomputed look-up tables.

RESULTS

The MTF of the bottom layer of the dual-layer model shows values decreasing more quickly with spatial frequency, compared to the top layer, due to the thicker bottom scintillator thickness and scatter from the top layer. A comparison with measurement shows NRMSE of 0.013 and 0.015 as well as identical MTF50 of 0.8 mm1 and 1.0 mm1 for the top and bottom layer respectively. For the DE imaging of the DE-phantom, although a maximum deviation of 3.3% is observed for the 10 mm aluminum and Teflon inserts at the top layer, the agreement for all other inserts is less than 2.2% of the measured value at both layers. Material decomposition of simulated scatter-free DE images gives an average accuracy in PMMA and aluminum composition of 4.9% and 10.3% for 11-30 mm PMMA and 1-10 mm aluminum objects respectively. A comparison of decomposed values using scatter containing measured and simulated DE images shows good agreement within statistical uncertainty.

CONCLUSION

Validation using both MTF and phantom imaging shows good agreement between simulation and measurements. With the present configuration of the digital prototype, the model can generate material decomposed images and virtual monoenergetic images.

[Analysis of big data characteristics of allergic rhinitis patients in Beijing City from 2016 to 2021]

To explore the characteristics of big data of patients with allergic rhinitis, including the time, population and spatial distribution of allergic rhinitis in Beijing from 2016 to 2021, so as to provide reference for the prevention and treatment of this disease. Descriptive epidemiological methods were used to analyze the distribution (including gender, age and location)and trend of allergic rhinitis patients in 30 pilot hospitals from January 2016 to December 2021, T test and Kruskal-Wallis rank sum test were used to test the statistical differences. The results showed that the number of patients with allergic rhinitis in 30 hospitals increased year by year from 2016 to 2019, with an increase of 97.9%. In 2020, the number of patients decreased. In 2021, the number of visits returned to the pre-epidemic level (461 332); The number of patients with allergic rhinitis was the highest in September, with a seasonal index of 177.6%, while the lowest number was in February, accounting for only 47.2%; a significant difference was observed in the number of patients in different age groups(H=45 319.48, P<0.05), and patients under 15 years old accounted for the highest proportion(819 284 visits); There were significant differences between patients of different genders in the 45-59 year old group (t=-4.26, P<0.05).There were relatively more patients with allergic rhinitis in Dongcheng District(31.1%) than in Huairou District and Miyun District (0.4%). In conclusion, since 2016, the number of patients increased significantly, with a varied trend in different seasons. Most patients were children. There were more patients in the central urban area than in the outer suburbs.

[Associations of cardiometabolic multimorbidity with grip strength and gait speed among older Chinese adults]

Objective: To investigate the associations of cardiometabolic multimorbidity (CMM) with grip strength and gait speed among older Chinese adults. Methods: This study included participants aged ≥60 years from the China Health and Retirement Longitudinal Survey during 2011-2015. Generalized estimating equation models were employed to estimate the associations of CMM with grip strength and gait speed. Results: A total of 6 357 participants were included to measure grip strength and 6 250 participants to measure gait speed. Compared with no cardiometabolic disease, participants with 1 (β=-0.018, 95%CI: -0.026--0.010), 2 (β=-0.029, 95%CI: -0.041- -0.018), and ≥3 (β=-0.050, 95%CI: -0.063- -0.037) cardiometabolic diseases were associated with a decreased grip strength. The associations between cardiometabolic disease counts (1: β=-0.052, 95%CI: -0.326-0.222; 2: β=-0.083, 95%CI: -0.506-0.340; ≥3: β=-0.186, 95%CI: -0.730-0.358) and gait speed were not statistically significant. The predictive value of gait speed of the participants with 0, 1, 2, and ≥3 cardiometabolic diseases were found to be 1.98 (95%CI: 1.38-2.58), 1.93 (95%CI: 1.34-2.51), 1.89 (95%CI: 1.18-2.61), and 1.79 (95%CI: 1.10-2.48) m/s respectively, which was clinically significant for the magnitude of the decrease. Cardiometabolic combinations with a higher risk of decreased grip strength and gait speed mainly seen in diabetes. Conclusions: Cardiometabolic disease counts and combinations were associated with grip strength and gait speed. Grip strength and gait speed can be used to measure CMM severity.

[Analysis of clinicopathological characteristics of IgG4-related sialadenitis]

Objective: To analyze the clinicopathological characteristics of IgG4-related sialadenitis (IgG4-RS). Methods: A total of 40 cases diagnosed with IgG4-RS were collected from the Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2019 to December 2022. Among them, there were 26 males and 14 females. The age range was 29-77 years old [(59.4±11.8) years old], with 23 patients being older than 60 years. The lesion site, imaging manifestations, histopathological features, serological test and treatment information of patients were collected. The expression of IgG4 and IgG proteins was detected by immunohistochemistry. Results: Submandibular region swelling was the most common initial symptom of IgG4-RS (38/40, 95.0%). All the patients having serum IgG4 levels> 1.35 g/L. Serum IgG4 levels were significantly increased in patients aged>60 years (Z=-2.45, P=0.014) and those involving multiple glands (Z=-2.04, P=0.042). Thirty six cases received major salivary gland biopsy, and all the cases showed dense lymphocyte and plasma cell infiltration. Lymphoid follicle, storiform fibrosis and obliterative phlebitis were seen in 88.9% (32/36), 63.9% (23/36), 30.6% (11/36) of the cases, respectively. Twenty one cases received labial salivary gland biopsy, 66.7% (14/21) showed lymphocyte and plasma cell infiltration, 19.0% (4/21) had lymphoid follicle structures, and 33.3% (7/21) showed no obvious histological abnormalities. No signs of fibrosis or obliterative phlebitis were observed in all labial salivary gland biopsies. And 95.0% (38/40) of cases had IgG4 positive plasma cell>10/HPF, 82.5% (33/40) of cases had IgG4/IgG positive plasma cell ratio>40%. All the patients had a decrease in serum IgG4 levels after glucocorticoid treatment, but only 21.4% (6/28) of cases had reduced to normal levels (≤1.35 g/L), and there were still significant fluctuations in serum IgG4 levels thereafter. Conclusions: IgG4-RS has a predilection for middle-aged and elderly male patients, and serum IgG4 levels are significantly related to the patient's age and whether multiple glands are involved. Labial salivary gland biopsy cannot replace submandibular gland for histopathological evaluation. It is a common phenomenon that serum IgG4 levels cannot restored to normal levels after glucocorticoid treatment. This study provides certain assistance for clinical and pathological diagnosis of IgG4-RS. This study is beneficial for further understanding IgG4-RS and improving the clinical and pathological diagnosis of the disease.

[Effect of the varicella vaccination on the clinical characteristics of herpes zoster cases aged 20 years and under]

To discuss the effect of varicella vaccination on the clinical characteristics of herpes zoster (shingles) cases aged 20 years and under, and analyze its clinical features. Based on the Yichang Health Big Data Platform, a descriptive study was conducted to collect the information of cases aged 20 years and under in three medical institutions of Yichang Central People's Hospital, Yichang First People's Hospital and Yichang Second People's Hospital from March 2019 to September 2020. According to the history of varicella vaccine, cases were divided into vaccination group and non-vaccination group, and their clinical features and outcomes were compared. The results showed that 46 shingles cases, aged from 7 to 20 years old, were included in this study. 26 males (56.5%), 20 females (43.5%), 15 cases in vaccination group (32.6%) and 31 cases in non-vaccination group (67.4%). 28 cases had thoracic involvement, followed by lumbar (n=8), cranial (n=7) involvements and extremities (n=7). The spread of herpes skin area: 2 cases involved too large area, 21 cases of 10 cm×10 cm, 14 cases of 5 cm×5 cm, 9 cases of 1 cm×1 cm. Herpes number: 26 cases had 10-49 herpes, followed by <10 herpes (n=9), uncountable herpes (n=7) and 50-99 herpes (n=4). The clinical course[M(Q₁,Q₃)] lasted 20.5 (13.5,24.8) d averagely, 5 cases had postherpetic neuralgia (PHN) and 1 case had respiratory complications. Shingles decrustation time was significantly shorter in vaccination group (Z=-2.01, P<0.05), and there was no significant difference in other characteristics by vaccination. In conclusion, the number and spread of shingles in most children and adolescents are less, and the complications such as PHN are less. Varicella vaccination can reduce the decrustation time and relieve shingles cases with some clinical symptoms.

Impact of a novel multilayer imager on metal artifacts in MV-CBCT

OBJECTIVE

Megavoltage cone-beam CT (MV-CBCT) imaging offers several advantages including reduced metal artifacts and accurate electron density mapping for adaptive or emergent situations. However, MV-CBCT imaging is limited by the poor efficiency of current detectors. Here we examine a new MV imager and compare CBCT reconstructions under clinically relevant scenarios. &#xD;Approach: A multilayer imager (MLI), consisting of four vertically stacked standard flat-panel imagers, was mounted to a clinical linear accelerator. A custom anthropomorphic pelvis phantom with replaceable femoral heads was imaged using MV-CBCT and kV-CBCT. Bone, aluminum, and titanium were used as femoral head inserts. 8MU 2.5MV scans were acquired for all four layers and (as reference) the top layer. Prostate and bladder were contoured on a reference CT and transferred to the other scans after rigid registration, from which the structural similarity index measure (SSIM) was calculated. Prostate and bladder were also contoured on CBCT scans without guidance, and Dice coefficients were compared to CT contours.&#xD;Main results: kV-CBCT demonstrated the highest SSIMs with bone inserts (prostate:0.86, bladder:0.94) and lowest with titanium inserts (0.32, 0.37). 4-layer MV-CBCT SSIMs were preserved with bone (0.75, 0.80) as compared to titanium (0.67, 0.74), outperforming kV-CBCT when metal is present. 1-layer MV-CBCT consistently underperformed 4-layer results across all phantom configurations. Unilateral titanium inserts and bilateral aluminum insert results fell between the bone and bilateral titanium results. Dice coefficients trended similarly, with 4-layer MV-CBCT reducing metal artifact impact relative to KV-CBCT to provide better soft-tissue identification. &#xD;Significance: MV-CBCT with a 4-layer MLI showed improvement over single-layer MV scans, approaching kV-CBCT quality for soft-tissue contrast. In the presence of artifact-producing metal implants, four-layer MV-CBCT scans outperformed kV-CBCT by eliminating artifacts and single-layer MV-CBCT by reducing noise. MV-CBCT with a novel multi-layer imager may be a valuable alternative to kV-CBCT, particularly in the presence of metal.

[Metformin use and risk of ischemic stroke in patients with type 2 diabetes: A cohort study]

OBJECTIVE

To explore the association between the use of metformin and the risk of ischemic stroke in patients with type 2 diabetes.

METHODS

A prospective cohort study was designed from the Fangshan family cohort in Beijing. According to metformin use at baseline, 2 625 patients with type 2 diabetes in Fangshan, Beijing were divided into metformin group or non-metformin group and the incidence of ischemic stroke between the different groups during follow-up was estimated and compared by Cox proportional hazard regression model. The participants with metformin were first compared with all the parti-cipants who did not use metformin, and then were further compared with those who did not use hypoglycemic agents and those who used other hypoglycemic agents.

RESULTS

The patients with type 2 diabetes were with an average age of (59.5±8.7) years, and 41.9% of them were male. The median follow-up time was 4.5 years. A total of 84 patients developed ischemic stroke during follow-up, with a crude incidence of 6.4 (95%CI: 5.0-7.7) per 1 000 person-years. Among all the participants, 1 149 (43.8%) took metformin, 1 476 (56.2%) were metformin non-users, including 593 (22.6%) used other hypoglycemic agents, and 883 (33.6%) did not use any hypoglycemic agents. Compared with metformin non-users, the Hazard ratio (HR) for ischemic stroke in metformin users was 0.58 (95%CI: 0.36-0.93; P = 0.024). Compared with other hypoglycemic agents, HR was 0.48 (95%CI: 0.28-0.84; P < 0.01); Compared with the group without hypoglycemic agents, HR was 0.65 (95%CI: 0.37-1.13; P=0.13). The association between metformin and ischemic stroke was statistically significant in the patients ≥ 60 years old compared with all the metformin non-users and those who used other hypoglycemic agents (HR: 0.48, 95%CI: 0.25-0.92; P < 0.05). Metformin use was associated with a lower incidence of ischemic stroke in the patients with good glycemic control (0.32, 95%CI: 0.13-0.77; P < 0.05). In the patients with poor glycemic control, and the association was not statistically significant (HR: 0.97, 95%CI: 0.53-1.79; P>0.05). There was an interaction between glycemic control and metformin use on incidence of ischemic stroke (P_interaction < 0.05). The results of the sensitivity analysis were consistent with the results in the main analysis.

CONCLUSION

Among patients with type 2 diabetic in rural areas of northern China, metformin use was associated with lower incidence of ischemic stroke, especially in patients older than 60 years. There was an interaction between glycemic control and metformin use in the incidence of ischemic stroke.

[Genotype-environment interaction on arterial stiffness: A pedigree-based study]

OBJECTIVE

To utilized the baseline data of the Beijing Fangshan Family Cohort Study, and to estimate whether the association between a healthy lifestyle and arterial stiffness might be modified by genetic effects.

METHODS

Probands and their relatives from 9 rural areas in Fangshan district, Beijing were included in this study. We developed a healthy lifestyle score based on five lifestyle behaviors: smoking, alcohol consumption, body mass index (BMI), dietary pattern, and physical activity. The measurements of arterial stiffness were brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI). A variance component model was used to determine the heritability of arterial stiffness. Genotype-environment interaction effects were performed by the maximum likelihood methods. Subsequently, 45 candidate single nucleotide polymorphisms (SNPs) located in the glycolipid metabolism pathway were selected, and generalized estimated equations were used to assess the gene-environment interaction effects between particular genetic loci and healthy lifestyles.

RESULTS

A total of 6 302 study subjects across 3 225 pedigrees were enrolled in this study, with a mean age of 56.9 years and 45.1% male. Heritability of baPWV and ABI was 0.360 (95%CI: 0.302-0.418) and 0.243 (95%CI: 0.175-0.311), respectively. Significant genotype-healthy diet interaction on baPWV and genotype-BMI interaction on ABI were observed. Following the findings of genotype-environment interaction analysis, we further identified two SNPs located in ADAMTS9-AS2 and CDH13 might modify the association between healthy dietary pattern and arterial stiffness, indicating that adherence to a healthy dietary pattern might attenuate the genetic risk on arterial stiffness. Three SNPs in CDKAL1, ATP8B2 and SLC30A8 were shown to interact with BMI, implying that maintaining BMI within a healthy range might decrease the genetic risk of arterial stiffness.

CONCLUSION

The current study discovered that genotype-healthy dietary pattern and genotype-BMI interactions might affect the risk of arterial stiffness. Furthermore, we identified five genetic loci that might modify the relationship between healthy dietary pattern and BMI with arterial stiffness. Our findings suggested that a healthy lifestyle may reduce the genetic risk of arterial stiffness. This study has laid the groundwork for future research exploring mechanisms of arterial stiffness.

[Genetic characterization of varicella-zoster virus in people aged 20 years and under in Yichang City of Hubei Province, 2019-2020]

Objective: To analyze the genetic characteristics of varicella-zoster virus (VZV) in people aged 20 years and under in Yichang City of Hubei Province from 2019 to 2020. Methods: Based on the Yichang Health Big Data Platform, we investigated cases 20 and under clinically diagnosed as herpes zoster in three hospitals from March 2019 to September 2020. Collecting vesicle fluid and throat swab samples of the cases and completing questionnaires to obtain basic information. Real-time fluorescent quantitative PCR was used for positive identification of the virus. PCR amplification of VZV's open reading frame (ORF) and sequencing of the products to determine the VZV genotype. Analyze mutations at some specific single nucleotide polymorphism (SNP) sites. Results: Among 46 cases of herpes zoster, the male to female ratio was 1.3∶1 (26∶20) and the age ranged from 7 to 20 years old. Fifteen cases had been vaccinated against varicella, including 13 and 2 cases of 1 and 2 doses, respectively. VZV strains were detected in 34 samples (73.91%), all belonging to Clade 2. Phylogenetic tree analysis of the nucleotide of ORF22 showed, compared with Clade 2 referenced strains, the sequence matching degree of nucleotide for all 34 samples was 99.0% to 100.0%. Conclusion: The main VZV strain causing herpes zoster in people aged 20 years and under in Yichang from 2019 to 2020 was Clade 2.

[Revision rate of periprosthetic joint infection post total hip or knee arthroplasty of 34 hospitals in China between 2015 and 2017: a multi-center survey]

Objective: To investigate the rate of periprosthetic joint infection (PJI) revision surgeries and clinical information of hip-/knee- PJI cases nationwide from 2015 to 2017 in China. Methods: An epidemiological investigation. A self-designed questionnaire and convenience sampling were used to survey 41 regional joint replacement centers nationwide from November 2018 to December 2019 in China. The PJI was diagnosed according to the Musculoskeletal Infection Association criteria. Data of PJI patients were obtained by searching the inpatient database of each hospital. Questionnaire entries were extracted from the clinical records by specialist. Then the differences in rate of PJI revision surgery between hip- and knee- PJI revision cases were calculated and compared. Results: Total of 36 hospitals (87.8%) nationwide reported data on 99 791 hip and knee arthroplasties performed from 2015 to 2017, with 946 revisions due to PJI (0.96%). The overall hip-PJI revision rate was 0.99% (481/48 574), and it was 0.97% (135/13 963), 0.97% (153/15 730) and 1.07% (193/17 881) in of 2015, 2016, 2017, respectively. The overall knee-PJI revision rate was 0.91% (465/51 271), and it was 0.90% (131/14 650), 0.88% (155/17 693) and 0.94% (179/18 982) in 2015, 2016, 2017, respectively. Heilongjiang (2.2%, 40/1 805), Fujian (2.2%, 45/2 017), Jiangsu (2.1%, 85/3 899), Gansu (2.1%, 29/1 377), Chongqing (1.8%, 64/3 523) reported relatively high revision rates. Conclusions: The overall PJI revision rate in 34 hospitals nationwide from 2015 to 2017 is 0.96%. The hip-PJI revision rate is slightly higher than that in the knee-PJI. There are differences in revision rates among hospitals in different regions.

Comparison of MR-soft tissue based versus biliary stent based alignment for image guidance in pancreatic SBRT

PURPOSE

The role of biliary stents in image-guided localization for pancreatic cancer has been inconclusive. To date, stent accuracy has been largely evaluated against implanted fiducials on cone beam computed tomography. We aim to use magnetic resonance (MR) soft tissue as a direct reference to examine the geometric and dosimetric impacts of stent-based localization on the newly available MR linear accelerator.

METHODS

Thirty pancreatic cancer patients (132 fractions) treated on our MR linear accelerator were identified to have a biliary stent. In our standard adaptive workflow, patients were set up to the target using soft tissue for image registration and structures were re-contoured on daily MR images. The original plan was then projected on treatment anatomy and dose predicted, followed by plan re-optimization and treatment delivery. These online predicted plans were soft tissue-based and served as reference plans. Retrospective image registration to the stent was performed offline to simulate stent-based localization and the magnitude of shifts was taken as the geometric accuracy of stent localization. New predicted plans were generated based on stent-alignment for dosimetric comparison.

RESULTS

Shifts were within 3 mm for 90% of the cases (mean = 1.5 mm); however, larger shifts up to 7.2 mm were observed. Average PTV coverage dropped by 1.1% with a maximum drop of 26.8%. The mean increase in V35Gy was 0.15, 0.05, 0.02, and 0.02 cc for duodenum, stomach, small bowel and large bowel, respectively. Stent alignment was significantly worse for all metrics except for small bowel (p = 0.07).

CONCLUSIONS

Overall discrepancy between stent- and soft tissue-alignment was modest; however, large discrepancies were observed for select cases. While PTV coverage loss may be compensated for by using a larger margin, the increase in dose to gastrointestinal organs at risk may limit the role of biliary stents in image-guided localization.

[Application of discrete event simulation model in analysis on cost-effectiveness of epidemiology screening]

Discrete event simulation (DES) model is based on individual data, by which discrete events over time are simulated to reflect disease progression. The effects of individual characteristics on disease progression could be considered in the DES model. Moreover, unlike state-transition models, DES model without setting of fixed cycle can contribute to more accurate estimation of event time, especially in the evaluation of the long-term effectiveness of screening strategies for complex diseases in which time dimension needs to be considered. This article introduces the general principles, construction steps, analytic methods and other relevant issues of the DES model. Based on a research case of estimating the cost-effectiveness of screening for abdominal aortic aneurysms in women aged 65 years and above in the United Kingdom, key points in applications of the DES model in analysis on effectiveness of complex disease screening are discussed in detail, including model construction and analysis and interpretation of the results. DES model can predict occurring time of discrete events accurately by establishing the distribution function of their occurring time and is increasingly used to evaluate the screening strategies for complex diseases in which time dimension needs to be considered. In the construction of DES model, it is necessary to pay close attention to the clear presentation of model structure and simulation process and follow the relevant reporting specification to conduct cost-effectiveness analysis to ensure the transparency and repeatability of the research.

[Progress in research of risk prediction of non-syndromic oral clefts using genetic information]

Non-syndromic oral cleft (NSOC), a common birth defect, remains to be a critical public health problem in China. In the context of adjustment of childbearing policy for two times in China and the increase of pregnancy at older childbearing age, NSOC risk prediction will provide evidence for high-risk population identification and prenatal counseling. Genome-wide association study and second generation sequencing have identified multiple loci associated with NSOC, facilitating the development of genetic risk prediction of NSOC. Despite the marked progress, risk prediction models of NSOC still faces multiple challenges. This paper summarizes the recent progress in research of NSOC risk prediction models based on the results of extensive literature retrieval to provide some insights for the model development regarding research design, variable selection, model-build strategy and evaluation methods.

[Residents' sense of acquisition and influencing factors in China's Sanitary City Initiative]

Objective: To analyze the residents' sense of acquisition (recognition, perceptibility and satisfaction) and influencing factors in China's Sanitary City Initiative. Methods: A cross-sectional survey was conducted from December 2020 to February 2021. The data about the residents' sense of acquisition were collected by using questionnaire from 2 465 residents who were aged ≥18 years and had lived in local communities for at least one year in 31, 14 and 16 cities with national sanitary city title in eastern, central and western China the influencing factors of residents' sense of acquisition in China's Sanitary City Initiative were analyzed by using multivariate multilevel model. Results: The total score of residents' sense of acquisition in China's Sanitary City Initiative was 231.15±32.45. After converting the scores according to the 100-score standardized method, the results showed that the recognition score, perception score and the satisfaction score were 85.02, 59.08 and 61.42, respectively. The results of influencing factors analysis showed that education level, gender, marital status, age, prevalence of physical exercise and self-assessment of health status were correlated with the scores of residents' recognition (β:1.24-2.54,all P<0.05); the concentration of inhalable fine particles , the green coverage of built-up area, the level of GDP per capita and the type of residential community, prevalence of physical exercise and self-assessment of health status were correlated with the score of residents' perception (β:1.76-8.86,all P<0.05); the concentration of inhalable fine particles , the green coverage of built-up area, the level of GDP per capita and the type of residential community, education level, prevalence of physical exercise and self-assessment of health status were correlated with the score of residents' satisfaction (β:1.34-6.26,all P<0.05). Conclusions: The total score of residents' sense of acquisition in China's Sanitary City Initiative was relatively high, indicating that the policy has been widely recognized. The detailed management of policy implementation should be strengthened in the future, and more attention needs to be paid to actual needs of the residents to further improve the residents' sense of acquisition in China's Sanitary City Initiative.

[Effect of laparoscopic ovarian cystectomy on ovarian reserve and the outcomes of in vitro fertilization patients with benign ovarian cysts]

Objective: To investigate the effect of laparoscopic ovarian cystectomy on anti-Mullerian hormone (AMH) level, ovarian response to gonadotropin stimulation and pregnancy rate for in vitro fertilization (IVF) patients with benign ovarian cysts. Methods: Patients with benign ovarian cysts who were admitted for cystectomy and had undergone IVF treatment were enrolled in the study. There were 373 participants with ovarian cysts underwent laparoscopic ovarian cystectomy in the experimental group. According to duration of post-surgery, there were four sub-groups: 1 year post-surgery (1Y POST), 2 years post-surgery (2Y POST), 4 years post-surgery (4Y POST) and ≥5 years post-surgery (≥5Y POST) in the experimental group. According to histopathologic types of ovarian cysts, there were two sub-groups: ovarian endometriotic cysts and ovarian non-endometriotic cysts. Two hundreds and three patients with no history of ovarian cysts and ovarian surgery were in the control group. The level of AMH and basic concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P), estradiol (E₂) were measured. Antral follicle counts (AFC) were calculated. There were other study variables: total dose of gonadotropins, duration of ovarian stimulation, the number of oocyte retrieved, the number of embryo obtained, blastocyst transfer rate and pregnancy rate. Results: The control group was matched as closely as possible to the experimental group, including age, body mass index and menstrual cycle (all P>0.05). Compared to the women in control group, the women in ovarian endometriotic cystectomy sub-group had significantly higher levels of basal FSH and basal P, lower level of AMH (all P<0.05); the women in ovarian endometriotic cysts sub-group had significantly higher dose of gonadotropins (all P<0.05); the women in ovarian endometriotic cysts ≥5Y POST sub-group had significantly lower number of oocyte retrieved, lower number of embryo obtained, lower blastocyst transfer rate, and lower pregnancy rate (all P<0.05). Compared to the women in control group, the women in ovarian non-endometriotic cysts sub-group had a significantly higher level of basal FSH and basal P (all P<0.05). The women in ovarian non-endometriotic cysts sub-group had lower level of AMH, higher dose of gonadotropins, lower number of oocyte retrieved, lower number of embryo obtained, lower rate of blastocyst transfer and lower rate of pregnancy than the control group but there were no statistically significant differences among them (all P>0.05). The women with unilateral ovarian endometriotic cysts had significantly lower number of oocyte retrieved on the side of surgery than another side (P<0.05). Conclusions: In short term laparoscopic ovarian cystectomy has no significant effect on ovarian reserve. But with long-term follow-up ovarian reserve, ovarian response to gonadotropin stimulation and pregnancy rate are decreased. The effect of laparoscopic ovarian cystectomy in benign cysts on ovarian is associated with whether or not it is the surgical side.

[Clinicopathological observation of 10 cases of salivary secretory carcinoma]

Objective: To investigate the clinical and pathological features of salivary secretory carcinoma (SSC). Methods: Ten cases of SSC confirmed in the Department of Pathology,Capital Medical University School of Stomatology from January 2014 to December 2021 were retrospectively included, including 5 males and 5 females, with a median age of 46.5 years. The microscopic morphology, immunophenotype, special staining and clinical follow-up of 10 cases of salivary secretory carcinoma were observed. Ten patients were tested with S-100, vimentin, mammaglobin, Dog-1, p63 and Ki-67, 9 cases with cytokeratin (CK) 8/18, 8 with CK7, 6 with calponin, 5 with smooth muscle actin (SMA) and GCDFP15, 4 with CK5/6 and 1 with SOX10. The ETV6-NTRK3 fusion gene was detected by fluorescence in situ hybridization. Results: Seven of the 10 SSC were located in the parotid gland and 3 were located in the cheeks. Histomorphology showed solid, papillary-cystic, follicular, microcystic, and macrocystic types. In 7 cases, tumor cells were dominated by single arrangement type, while certain mixed arrangements existed in some areas. The cytoplasm of the tumor cells was rich in eosinophilic, fine granular or vacuolar shapes, and clear cytoplasm was seen in 2 cases. The nuclei were mostly oval-shaped vesicular nuclei, with nucleoli in the center. Immunohistochemistry showed CK7 (8/8) positive, CK8/18 (9/9) positive, S-100 (10/10) positive, vimentin (5/10) positive, (4/10) partially positive and (1/10) less partially positive, mammaglobin (7/10) positive, (1/10) partially positive and (2/10) some individual cells positive, Dog-1 (10/10) negative, CK5/6 (4/4) negative, p63 (7/10) negative and (3/10) partially positive, SMA (5/5) negative, calponin (6/6) negative, and Ki-67 index was 5%-20%. Secretions of 5 cases showed periodic acid-Schiff (PAS) and PAS with diastase (PAS-D) staining positive. All 10 cases showed ETV6-NTRK3 fusion positive. Six cases were successfully followed up for 32-91 months, of which 2 cases recurred after 28 and 74 months and underwent surgical resection again. All cases followed up are alive and disease-free. Conclusions: The salivary secretory carcinoma is a rare low-grade malignant tumor. In certain cases, morphology is atypical and mammaglobin is immunohistochemically positive in only individual tumor cells. Therefore, the diagnosis should be supported with morphology, immunohistochemical staining, and molecular feature preferably.

[Comparison of programmed death-ligand 1 protein expression between primary tumors and lymph node metastatic lesions in oral squamous cell carcinoma]

Objective: To investigate the difference of programmed death-ligand 1 (PD-L1) expression between primary lesions and lymph node metastatic lesions in oral squamous cell carcinoma. Methods: Eighty-two patients diagnosed with oral squamous cell carcinoma from December 2020 to July 2021 in Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine & College of Stomatology, Shanghai Jiao Tong University, were enrolled in this study. All the patients underwent neck dissection concurrently and had lymph node metastasis. Among them, there were 28 females and 54 males. The age range was 24-79 years old [(58.6±11.7) years old]. The expression of PD-L1 protein in primary tumors and lymph node metastatic lesions was detected by immunohistochemistry. Combined positive score (CPS) was used to evaluate the PD-L1 expression. And the difference of PD-L1 expression between primary tumors and metastatic lesions was analyzed. Results: Among 82 primary tumors, 9 cases (11%) had PD-L1 CPS<1, 31 cases (38%)≥ 1 and <20, and 42 cases (51%)≥20. Cases with perineural invasion had lower CPS (χ²=6.35, P=0.042). Among 82 matched lymph node metastatic lesions, 9 cases (11%) had CPS<1, 38 cases (46%)≥1 and<20, and 35 cases (43%)≥20. The CPS of 27 pairs (33%) of primary and metastatic lesions were discordant. The statistical results showed that the Kappa value of consistency evaluation was 0.446, indicating that the consistency of PD-L1 CPS in primary and metastatic lesions of OSCC was medium. Conclusions: There are differences in PD-L1 expression between the primary lesion of OSCC and cervical lymph node metastatic lesions, and the consistency is medium. In the routine practice, lymph node metastatic lesions should be carefully used to replace the primary lesion for PD-L1 CPS evaluating.

[Establishment of patient-derived salivary gland basal cell adenoma organoids]

Objective: To establish an in vitro organoid model of human salivary gland basal cell adenoma (BCA). Methods: Fresh tumor sample from a 66-year-old female patient diagnosed with salivary gland BCA was collected from the Dpartment of Oral pathology, Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine in October 2021. And the organoid culture was performed in vitro in a culture medium based on solid droplets of matrix gel, and the growth of the organoid was observed by inverted microscopy. After 14 days, the organoid was fixed in 10% neutral formalin and made into paraffin blocks by agar pre-embedding paraffin embedding method, sectioned. HE staining, morphological observation and immunohistochemical staining of p63, Ki-67, cytokeratin14 (CK14), β-catenin, S-100 and calponin were used for organoids identification. Results: The established BCA organoids were lobulated nodular locally under light microscopy, with deposition of eosinophilic glass-like material around the nests of organoid cells, similar to the morphological architectures of the parental BCA. Immunohistochemistry showed that organoids expressed CK14, p63, and β-catenin in various degree, which was consistent with the immunophenotypic characteristics of the parental BCA tumor cells. Conclusions: An in vitro culture system of BCA organoids was preliminarily established which provides a new model for the study of the pathogenesis of salivary gland tumors.

Synthetic CT generation for MRI-guided adaptive radiotherapy in prostate cancer

Current MRI-guided adaptive radiotherapy (MRgART) workflows require fraction-specific electron and/or mass density maps, which are created by deformable image registration (DIR) between the simulation CT images and daily MR images. Manual density overrides may also be needed where DIR-produced results are inaccurate. This approach slows the adaptive radiotherapy workflow and introduces additional dosimetric uncertainties, especially in the presence of the magnetic field. This study investigated a method based on a conditional generative adversarial network (cGAN) with a multi-planar method to generate synthetic CT images from low-field MR images to improve efficiency in MRgART workflows for prostate cancer. Fifty-seven male patients, who received MRI-guided radiation therapy to the pelvis using the ViewRay MRIdian Linac, were selected. Forty-five cases were randomly assigned to the training cohort with the remaining twelve cases assigned to the validation/testing cohort. All patient datasets had a semi-paired DIR-deformed CT-sim image and 0.35T MR image acquired using a true fast imaging with steady-state precession (TrueFISP) sequence. Synthetic CT images were compared with deformed CT images to evaluate image quality and dosimetric accuracy. To evaluate the dosimetric accuracy of this method, clinical plans were recalculated on synthetic CT images in the MRIdian treatment planning system. Dose volume histograms for planning target volumes (PTVs) and organs-at-risk (OARs) and dose distributions using gamma analyses were evaluated. The mean-absolute-errors (MAEs) in CT numbers were 30.1 ± 4.2 HU, 19.6 ± 2.3 HU and 158.5 ± 26.0 HU for the whole pelvis, soft tissue, and bone, respectively. The peak signal-to-noise ratio was 35.2 ± 1.7 and the structural index similarity measure was 0.9758 ± 0.0035. The dosimetric difference was on average less than 1% for all PTV and OAR metrics. Plans showed good agreement with gamma pass rates of 99% and 99.9% for 1%/1 mm and 2%/2 mm, respectively. Our study demonstrates the potential of using synthetic CT images created with a multi-planar cGAN method from 0.35T MRI TrueFISP images for the MRgART treatment of prostate radiotherapy. Future work will validate the method in a large cohort of patients and investigate the limitations of the method in the adaptive workflow.

Analysis of the Rate of Re-planning in Spot-Scanning Proton Therapy

Purpose

Finite proton range affords improved dose conformality of radiation therapy when patient regions-of-interest geometries are well characterized. Substantial changes in patient anatomy necessitate re-planning (RP) to maintain effective, safe treatment. Regularly planned verification scanning (VS) is performed to ensure consistent treatment quality. Substantial resources, however, are required to conduct an effective proton plan verification program, which includes but is not limited to, additional computed tomography (CT) scanner time and dedicated personnel: radiation therapists, medical physicists, physicians, and medical dosimetrists.

Materials and Methods

Verification scans (VSs) and re-plans (RPs) of 711 patients treated with proton therapy between June 2015 and June 2018 were studied. All treatment RP was performed with the intent to maintain original plan integrity and coverage. The treatments were classified by anatomic site: brain, craniospinal, bone, spine, head and neck (H&N), lung or chest, breast, prostate, rectum, anus, pelvis, esophagus, liver, abdomen, and extremity. Within each group, the dates of initial simulation scan, number of VSs, number of fractions completed at the time of VS, and the frequency of RP were collected. Data were analyzed in terms of rate of RP and individual likelihood of RP.

Results

A total of 2196 VSs and 201 RPs were performed across all treatment sites. H&N and lung or chest disease sites represented the largest proportion of plan modifications in terms of rate of re-plan (RoR: 54% and 58%, respectively) and individual likelihood of RP on a per patient basis (likelihood of RP [RP%]: 46% and 39%, respectively). These sites required RP beyond 4 weeks of treatment, suggesting continued benefit for frequent, periodic VS. Disease sites in the lower pelvis demonstrated a low yield for RP per VS (0.01-0.02), suggesting that decreasing VS frequency, particularly late in treatment, may be reasonable.

Conclusions

A large degree of variation in RoR and individual RP% was observed between anatomic treatment sites. The present retrospective analysis provides data to help develop anatomic site–based VS protocols.

[The relationship between triglyceride glucose index and risk of cardiovascular disease among Kazakh and Uygur population in Xinjiang: a retrospective cohort analysis]

Objective: To analyze whether triglyceride-glucose (TyG) index is associated with increased risk of cardiovascular diseases (CVD) and the value of TyG index in predicting CVD risk among Kazakh and Uighur population of Xinjiang. Methods: In this study, 5 375 Kazakh and Uygur people of Xinyuan county and Jiashi county were selected as the research objects. Subjects were divided into four groups based on the quartile of the TyG index level. Cox regression model was used to analyze the association between TyG index with the risk of CVD. The dose-response relationship between TyG index and CVD risk was described by restricted cubic splines. The area under the receiver operating characteristic curve, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to estimate the value of TyG index for predicting CVD. Mediating effect analysis was conducted to analyze the mediating effect of TyG index in the association between body mass index and CVD. Results: The age of subjects was 41.06（30.11，53.00）years old, with 46.30%（2 489/5 375）was male. After multivariate adjustment, there was an increasing trend between the risk of CVD and the higher TyG index P_trend<0.001, compared with subjects of TyG index in Q₁, the HR (95%CI) of Q₂, Q₃, and Q₄ groups was 1.53, 1.23 and 1.73, respectively. Restricted cubic splines showed that TyG index was the linearly associated with the risk of CVD. TyG index could improve the prediction ability of Framingham model for the risk of CVD (NRI=0.106,P=0.010; IDI=0.003,P=0.030). The mediating effect analysis showed that in the relationship between body mass index and CVD, the TyG index had a mediating effect (P<0.001), and the ratio of mediating effect was 12.69%. Conclusion: TyG index is an independent predictor of CVD risk among kazakh and Uygur population in Xinjiang and has a good predictive value for the risk of CVD.

Physical characterization of therapeutic proton delivery through common dental materials

PURPOSE

Dental fixtures are commonplace in an aging, radiation treatment population. The current, local standard of practice in particle therapy is to employ treatment geometries to avoid delivery through implanted dental fixtures. The present study aims to observe the physical effect of delivering therapeutic proton beams through common dental fixture materials as prelude to an eventual goal of assessing the feasibility of using treatment geometries not specified for avoidance of oral implants. A sampling of common dental materials was selected based on prosthodontic consult and was evaluated in terms of relative stopping power and three-dimensional (3D) dose perturbation.

METHODS

Amalgams, porcelain-fused-to-metal (PFM) crowns consisting of zirconia and non-noble base metals, and lithium disilicate implants were chosen for analysis. Theoretical stopping power (S) and mass stopping power (S/ρ) were calculated using the Stopping and Range of Ions in Matter (SRIM) application, basing stoichiometric compositions of each fixture on published materials data. S and S/ρ were calculated for a range of historically available compositions of amalgams from 1900 until the current era. The perturbance of S and S/ρ as a function of clinically relevant ranges of amalgam compositions for the modern era was analyzed. Water equivalent thickness (WET) and relative stopping power (S_rel ) of each material was measured for a clinical spot-scanning proton beam with monoenergies of 159.9 and 228.8 MeV with a multi-layer ionization chamber (MLIC). Subsequently, 3D dose perturbation was assessed by delivering proton beams through a custom phantom designed to simulate both en-face and on-edge treatment geometries through the selected materials. A treatment plan mimicking the experimental delivery was constructed in the institutional treatment planning system and calculated using TOPAS based Monte Carlo Simulation (MCS). Experimental results were used to validate the MCS. Finally, TPS outputs were compared to MCS to determine the accuracy of the dose calculation model.

RESULTS

Historical compositions of amalgams ranged in S from 44.8 to 42.9 MeV/cm, with the greatest deviation being observed for the 1900-1959 era. Deviation as a function of amalgam composition from the modern era was most sensitive to proportion of Hg, accounting for deviations up to -4.2% at the greatest clinically relevant concentration. S/ρ was not found to vary greatly between each porcelain and metal alloy material for porcelain-fused-to-metal (PFM) type crowns. Relative stopping powers ranged between 1.3 and 5.4 for all studied materials, suggesting substantial changes in proton range with respect to water. Film measurements of pristine spots confirm dose perturbance and shortening of proton range, with an upstream shift of each Bragg peak being observed directly behind the installed fixture. At high energies, cold spots were found in all cases directly behind each material feature with a medial fill-in of dose occurring distally. Qualitative agreement of spot perturbance was confirmed between film measurements and MCS. Finally, when comparing integrated depth doses (IDD) by summing over all axial directions, good agreement is observed between TPS and MCS.

CONCLUSIONS

All dental materials studied substantially perturbed the dosimetry of pristine proton spots both in terms of WET/S_rel as well as the spatial distribution of dose. Proton range was quantifiably shortened, and each dental material affected a cold spot directly behind the object with medial dose back-filling was observed distally. Monte Carlo simulations and Eclipse dose calculations exhibited good agreement with measurements, suggesting that treatment planning without employing avoidance strategies may be possible with further investigation. This article is protected by copyright. All rights reserved.

[Relationship between obesity and death by multi-morbidity status in older adults in China]

Objective: To explore the relationship between obesity status and death stratified by different multi-morbidity status in older adults in China. Methods: Data for older Chinese adults aged ≥65 years were from Chinese Longitudinal Healthy Longevity Survey (CLHLS). Multi-morbidity patterns based on 13 chronic conditions were explored using exploratory factor analysis. Cox models were used to examine relationships between obesity status and death stratified by disease count and multi-morbidity patterns at baseline, respectively. Besides, obesity status was defined by baseline body mass index and waist circumference. Results: A total of 6 272 participants were included in the analyses. Multi-morbidity including cardio-metabolic, sensory perception and other patterns were identified. For those without any chronic condition, compared with those without central obesity, central obesity was associated with a higher risk for death (HR=1.66, 95%CI:1.04-2.66). For those only with one chronic condition, compared with normal weight, underweight was associated with a higher risk for death (HR=1.41, 95%CI: 1.10-1.80). For those with multi-morbidity, compared with normal weight, underweight increased the risk for death (HR=1.19, 95%CI:1.05-1.34). Compared with those without central obesity, central obesity decreased the risk for death (HR=0.88, 95%CI:0.78-0.99). Conclusions: Relationships between obesity status and death varied by multi-morbidity status in older adults in China. Underweight and non-central obesity were associated with increased risks for death in older adults with only one chronic disease or multi-morbidity. Therefore, it is necessary to pay attention to multi-morbidity status in the management of obesity in older adults and provide effective targeted body weight management plan.

[Programmed death ligand 1 expression and CD8+T lymphocyte infiltration in salivary gland lymphoepithelial carcinoma]

Objective: To study the expression of programmed death ligand-1 (PD-L1) in tumor cells and CD8⁺T lymphocytes in tumor infiltrating lymphocytes, and to analyze the correlation of PD-L1 expression with infiltration of CD8⁺T lymphocytes and clinicopathologic features in salivary gland lymphoepithelial carcinoma (LEC). Methods: Forty-two cases of primary salivary LECs and 21 cases of secondary salivary LECs were enrolled at the Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University between 2015 and 2017. The expression of Epstein-Barr (EB) virus, PD-L1 and CD8 was examined using chromogenic in situ hybridization (CISH) and immunohistochemistry (IHC) staining. The data were analyzed using SPSS 23.0 software package. Results: EB virus was detected in 61 cases (61/63, 96.8%), including 42 (42/42, 100%) primary LECs and 19 (19/21, 90.5%) secondary LECs. The PD-L1 positive rate (score ≥1) was 97.6% (41/42), and its high-expression rate (score ≥20) was 78.6% (33/42) in primary LECs. The PD-L1 positive rate (score ≥1) was 71.4% (15/21), and its high-expression rate (≥20) was 38.1% (8/21) in secondary LECs. However, the PD-L1 positive rate (score ≥1, P=0.004) and high-expression rate (score ≥20, P=0.001) in primary LECs were higher than those in secondary LECs. There was no difference in the infiltration degree of CD8⁺T lymphocytes between primary and secondary LECs. There was a significant correlation between the expression of PD-L1 and CD8 in primary LECs (P=0.001) and in secondary LECs (P=0.048), respectively. Conclusions: There is PD-L1 expression in primary and secondary salivary LECs, while the expression rate is higher in primary LECs than secondary LECs. The combination of PD-L1 expression and CD8⁺T lymphocytes' presence suggest that most LEC patients might be responsive to immunotherapy, and primary LECs might be more significantly responsive than secondary LECs.

[Study on the incidence of adult herpes zoster in Yichang city and its association with early-life famine exposure]

Based on Yichang health big data platform, 850 608 patients from September 2018 to September 2019 were included in this study. According to the date of birth, the participants were divided into early childhood famine exposure group, fetal famine exposure group and non-famine exposure group. The incidence of adult herpes zoster (HZ) in Yichang city was analyzed, and the correlation between early life famine exposure and adult HZ was analyzed. In 2019, the crude incidence rate of adult HZ in Yichang was 6.83‰. The crude incidence rate of adult HZ in females (7.26‰) was higher than that in males (6.40‰). Compared with the non-famine exposure group, fetal famine exposure was associated with the incidence of adult HZ (OR=1.21; 95%CI: 1.01-1.45, P=0.041). After stratification by sex, fetal famine exposure was only found to be associated with the onset of adult HZ in females (OR=1.28, 95%CI:1.02-1.61, P=0.034).

[A Meta-analysis on varicella-zoster virus antibody levels in healthy population in China]

Objective: To systematically analyze and evaluate the IgG antibody levels of varicella-zoster virus (VZV) in healthy population in China. Methods: CNKI, Wanfang, CBM and PubMed databases were used for the retrieval of literatures about VZV IgG antibody levels in healthy people in China from January 1, 2000 to November 3, 2020. The quality of the included papers was evaluated by the critical appraisal tools for cross sectional study from Joanna Briggs Institute (JBL). The stratified analysis on the IgG antibody levels in populations in different age groups, provinces, regions, gender groups, and years was performed by using software Stata 14.0. Results: A total of 59 papers were included that met the inclusion criteria, including 51 papers in Chinese and 8 papers in English. There were 22 papers with quality score of 8, 16 papers with quality score of 7, 15 papers with quality score of 6, and 6 papers with quality score of 5. Meta-analysis showed that the positive rate of VZV IgG antibody in healthy population in China was 64% (95%CI:60%-67%, I² =98.7%), and the IgG antibody levels were reported in the papers for 22 provinces of China. The positive rate of VZV IgG antibody was highest in Yunnan (79%, 95%CI: 64%-93%, I² =94.7%) and lowest in Inner Mongolia (50%, 95%CI: 46%-54%); the positive rate of VZV IgG antibody was highest in Northeastern China (71%, 95%CI: 69%-73%) and lowest in Eastern China (62%, 95%CI: 57%-67%); the positive rate of VZV IgG antibody in urban population was higher than that in rural population (RR=1.08, 95%CI: 1.04-1.11). The positive rate of VZV IgG antibody in women was higher than that in men (RR=1.10, 95%CI: 1.08-1.11); the positive rate of VZV IgG antibody in the population increased with age; and the positive rate of VZV IgG antibody increased with the change of sampling time. Conclusion: The positive rate of VZV IgG antibody in healthy population in China was relatively low; the coverage of varicella vaccine should be improved for the outbreak control and incidence reduction of varicella in China.

[Association analysis of famine exposure during early life and risk of hypertension in adulthood]

Objective: To explore the relationship between exposure to famine in early life and the risk of hypertension in adulthood. Methods: The medical data of Yichang Health Management Big Data Center from 2018 to 2019 were analyzed. A retrospective cohort study design was adopted, with hypertension as the study outcome, and different life periods exposed to the Great Famine in China were divided into groups. Multivariate logistic regression model was used to analyze the relationship between famine exposure in early life and hypertension in adulthood. At the same time, the interaction between gender and famine exposure was analyzed. Results: The age of 142 016 subjects was (60. 56±4.43). Among them, men accounted for 46.36% (65 845/142 016) and women accounted for 53.64% (76 171/142 016). There are 42 575(29.98%), 19 644(13.83%), 28 405(20.00%), 28 305(19.93%), 23 087 (19.93%) in non-famine exposure group, fetal famine exposure group, early childhood famine exposure group and late childhood famine exposure group, respectively. The prevalence of hypertension was 17.57% (24 947 cases). Multivariate logistic regression model analysis showed that after adjusting for related confounding factors, compared with non-famine exposure group, the risk of hypertension in fetal, early childhood, middle childhood and late childhood famine exposure group was higher and the OR (95%CI) values were 1.16 (1.11-1.22), 1.27 (1.21-1.33), 1.54 (1.47-1.60) and 1.84 (1.76-1.92), respectively. There was an interaction between sex and famine exposure group (P<0.001). The above association is stronger among women than among men. Conclusion: Famine exposure in early life may increase the risk of hypertension in adulthood, and the risk of women is greater than that of men.

Abbreviated on-treatment CBCT using roughness penalized mono-energization of kV-MV data and a multi-layer MV imager

Simultaneous acquisition of cone beam CT (CBCT) projections using both the kV and MV imagers of an image guided radiotherapy system reduces set-up scan times-a benefit to lung cancer radiation oncology patients-but increases noise in the 3D reconstruction. In this article, we present a kV-MV scan time reduction technique that uses two noise-reducing measures to achieve superior performance. The first is a high-DQE multi-layer MV imager prototype. The second is a beam hardening correction algorithm which combines poly-energetic modeling with edge-preserving, regularized smoothing of the projections. Performance was tested in real acquisitions of the Catphan 604 and a thorax phantom. Percent noise was quantified from voxel values in a soft tissue volume of interest (VOI) while edge blur was quantified from a VOI straddling a boundary between air and soft material. Comparisons in noise/resolution performance trade-off were made between our proposed approach, a dose-equivalent kV-only scan, and a kV-MV reconstruction technique previously published by Yinet al(2005Med. Phys.329). The proposed technique demonstrated lower noise as a function of spatial resolution than the baseline kV-MV method, notably a 50% noise reduction at typical edge blur levels. Our proposed method also exhibited fainter non-uniformity artifacts and in some cases superior contrast. Overall, we find that the combination of a multi-layer MV imager, acquiring at a LINAC source energy of 2.5 MV, and a denoised beam hardening correction algorithm enables noise, resolution, and dose performance comparable to standard kV-imager only set-up CBCT, but with nearly half the gantry rotation time.

[Applications of Markov model for cost-effectiveness analysis of screening in epidemiology]

Cost-effectiveness analysis of screening in epidemiology is essential for public health decision-making. This paper describes the general principles, basic steps involved in implementation, analytic methods and other related issues of Markov model. Based on a practical research case of evaluating the cost-effectiveness of primary open-angle glaucoma screening in a Chinese population, key points in applications of Markov model for cost-effectiveness analysis of screening were discussed in detail, including model development, parameters definition, available software, base case analysis, sensitivity analysis and the interpretation of the results. For better supporting evidence-informed decision making in public health, future studies should be aware of the accuracy of parameters in Markov models and the transparency of the models and results, as well as complying with the relevant reporting standards.

Vitamin A with L-ascorbic acid sodium salt improves the growth performance, immune function and antioxidant capacity of weaned pigs

Vitamin A is easily degraded by environmental factors. Therefore, it is very important to add antioxidants during Vitamin A production. In the past, ethoxyquin (EQ) was widely used, but recent studies have found that it has potential toxicity. Therefore, in this study, we evaluated the antioxidant activities of 4 antioxidants in vitro: EQ, butylated hydroxytoluene, α-tocopherol and L-ascorbic acid sodium salt (Vitamin C sodium). In vitro experiments showed that Vitamin C sodium had better antioxidant capacity. Then, we explored the effects of different antioxidant types of Vitamin A on the growth performance, immune function and antioxidant capacity of weaned pigs. In total, 288 weaned piglets with an initial mean BW of 8.34 ± 0.02 kg at 30 days old were randomly divided into three groups with four replicates and 24 piglets per replicate for 35 days of feeding. The experimental diets were as follows: i) basal diet without external Vitamin A (NC); ii) basal diet supplemented with 12000 IU/kg EQ Vitamin A and iii) basal diet supplemented with 12000 IU/kg Vitamin C sodium Vitamin A. On day 36, two pigs from each replicate were selected to collect serum samples. The in vivo results showed that pigs in the EQ Vitamin A and Vitamin C sodium Vitamin A groups had significantly higher final weight and average daily gain (P < 0.05). During the trial, the levels of IgG and glutathione peroxidase in the EQ Vitamin A and Vitamin C sodium Vitamin A groups were significantly higher than those in the NC group (P < 0.05), and the malondialdehyde content was significantly lower (P < 0.05). On the 36th day, the levels of IgA and total antioxidant capacity in the Vitamin C sodium Vitamin A group were significantly higher than those in the EQ Vitamin A and NC (P < 0.05) groups. Thus, Vitamin C sodium Vitamin A can significantly improve the growth performance, antioxidant capacity and immune function of weaned pigs. Meanwhile, Vitamin C sodium may replace EQ as an antioxidant additive for Vitamin A.

Construction of SNP-STR Multiplex Amplification System with Genetic Markers and Its Forensic Application

Abstract

Objective To select and develop a SNP-STR multiplex amplification system with genetic markers compatible with current STR databases. To understand its genetic polymorphisms in Sichuan Han population and its application value in DNA mixture analysis. Methods Based on the STR genetic markers in commercial kits, SNPs adjacent to these STR markers were selected to be SNP-STR genetic markers. A SNP-STR multiplex amplification system with genetic markers based on allele-specific amplification was constructed using allele-specific amplification primers. The genetic polymorphism of the system in the Sichuan Han population was investigated and the efficiency of systems with different numbers of loci to detect the two individual DNA mixture samples was evaluated. Results An allele-specific multiplex amplification system constituted of 13 SNP-STR genetic markers was selected and constructed. In Sichuan Han population, the heterozygosity of each locus ranged from 0.76 to 0.88, and the combined discrimination power reached 0.999 999 999 999 999 968. In the analysis of the two individual DNA mixture samples： for single-locus amplification, the genotype of the minor components can still be detected when the mixture ratio reaches 1 000∶1; for multiple loci multiplex amplification, the maximum mixture ratio can reach 500∶1. As the number of loci in the system increased, the detection efficiency of the minor components in the DNA mixture decreased. Conclusion SNP-STR genetic markers have a higher polymorphism than STR. The multiplex amplification system made of SNP-STR genetic markers has a better analysis efficiency for mixed samples than traditional STR multiplex amplification system.

[Epidemiological characteristics of human brucellosis in Tongliao city of Inner Mongolia Autonomous Region, 2004-2018]

Objective: To analyze the epidemiological characteristics of human brucellosis (HB), evolution and origin feature of Brucella strains in Tongliao city, Inner Mongolia Autonomous Region during 2004-2018, and to provide evidence for strategy development against the disease. Methods: Data from the reports on HB in Tongliao during 2004-2018 were extracted from the China Information System for Disease Control and Prevention before being analyzed with software Excel 2016. Epidemiologic feature was described, using the number of cases, constituent ratio and related rates. Conventional biotypes methods were used for identification of species/biovars strains while species of six Brucella strains were further verified by AMOS-PCR. Cluster analyze on six Brucella strains were performed with Bio-Numerics 5.0 software and for examining and revealing the genetic characteristics of the related strains. Results: During 2004-2018, a total of 16 704 HB cases were reported, with the incidence rate as 35.41/100 000. The incidence rates appeared as 110.51/100 000 in Jarud Banner and 67.84/100 000 in Kulun flag, which were both higher than the other areas. Most of the cases were reported in the 40-54 year olds, which accounted for 48.75% (8 143/16 704). The number of HB in farmers appeared as 14 873, which counted for 89.04% (14 873/16 704) of all the cases. Male to female ratio of incidence was 2.40∶1. Most of the reported cases appeared between March to May, which accounted for 56.30% (9 405/16 704). Peak of the disease was seen in April. Using the conventional identification method, results showed that the available six strains all belonged to B. melitensis, including three of them as B. melitensis bv.1 and others three strains as B. melitensis bv. 3. Results from the amplified AMOS-PCR showed that all the strains were B. melitensis. The six strains clustered in two MLVA-11 genotypes (111 and 116) and all belonged to the Eastern Mediterranean lineage. Based on the MLVA-16 cluster analysis, results suggested that strains from this study were having close genetic relationship with B. melitensis strains that were from Jilin and Heilongjiang provinces. Conclusions: Human brucellosis identified in Tongliao area was with greater risk in spreading the disease to the vicinity. Our findings indicated that the programs on detection and control of the disease should be strengthened.

Low-Dose Hypofractionated Total Skin Electron Beam Therapy for Adult Cutaneous T-Cell Lymphoma

Purpose

Historically, the standard of care for total skin electron beam therapy (TSEBT) delivered 30 to 36 Gy over 5 to 10 weeks. Given the high risk of relapse, a majority of patients require additional treatments. Therefore, attempts to use a shortened course of TSEBT have been investigated.

Methods and Materials

We conducted a single-institution retrospective review to evaluate disease response, control, and toxicity using a low-dose, hypofractionated course of TSEBT (HTSEBT) in patients with mycosis fungoides.

Results

Forty patients received 57 courses of HTSEBT. Median dose (Gy)/fractionation was 12/3, spanning a median time of 2.4 weeks. Overall response rate of patients assessed (n = 54) was 100%. Thirty-one courses (57.4%) resulted in a complete response and 23 courses (42.6%) resulted in a partial response. Cumulative incidence of progressive skin disease at 3 months was 37.2%, at 6 months, 56.9%, and at 1 year, 81.5%. Of the 40 patients treated with a first course of HTSEBT, 31 received subsequent courses of radiotherapy. Cumulative incidence of subsequent treatment was 28.0% at 3 months, 46.8% at 6 months, and 70.0% at 1 year. Patients who underwent repeat courses of HTSEBT continued to have similar treatment responses to repeat courses without increased toxicities. Toxicities from all courses were acceptable with the exception of 1 patient, who experienced grade 4 skin toxicity (moist desquamation requiring hospitalization).

Conclusions

Low-dose HTSEBT provides good palliation in patients with cutaneous T-cell lymphoma with a satisfactory response and toxicity profile. HTSEBT allows therapy to be completed in far fewer treatments. Low-dose HTSEBT is an appropriate treatment option for patients unable to come for daily treatment. HTSEBT provides a way to decrease exposure to other patients and staff during public health emergencies such as the coronavirus disease 2019 (COVID-19) pandemic.

[Application of the China-PAR stroke risk equations in a rural northern Chinese population]

OBJECTIVE

To validate five-year risk prediction models for stroke in a contemporary rural Northern Chinese population.

METHODS

Totally 6 483 rural adults aged 40 to 79 years without cardiovascular diseases were enrolled at baseline between June and August 2010, and followed up through January 2017. Expected prediction risk using the China-PAR (prediction for atherosclerotic cardiovascular disease risk in China) stroke risk equations were compared with the new Framingham stroke risk profile (FSRP). The recalibrated models were applied by adjusting the five-year baseline survival rate and the mean score to our rural northern Chinese population, while keeping other coefficient parameters the same as the original models. Kaplan-Meier analysis was used to obtain the observed event (nonfatal or fatal stroke) rate for the five years, and the expected-observed ratios were calculated to evaluate overestimation or underestimation in the cohort. The models were assessed by discrimination C statistic, calibration χ², and calibration charts and plots for illustration as well.

RESULTS

Over an average of (5.83 ± 1.14) years of the follow-up in this validation cohort with 6 483 rural Chinese participants, 438 subjects deve-loped a first stroke event. Recalibrated China-PAR stroke risk equations and FSRP well-performed for predicting five-year stroke risk in men, and had C statistics of 0.709 (95%CI, 0.675 - 0.743) and 0.721 (95%CI, 0.688 - 0.754), with calibration χ² values being 5.7 (P = 0.770) and 13.6 (P = 0.137), respectively. However, both China-PAR and FSRP overestimated stroke events by 11.6% and 30.0% in women, and had C statistics of 0.713 (95%CI, 0.684-0.743) and 0.710 (95%CI, 0.679-0.740), respectively. Calibration χ² values in women were 12.5 (P = 0.188) for China-PAR and 24.0 (P = 0.004) for FSRP. In addition, the calibration charts and plots illustrated good agreement between the observations and the predictions only in the China-PAR stroke risk equations, especially for men.

CONCLUSION

In this validation cohort of rural northern Chinese adults, the China-PAR models had better performance of five-year stroke risk prediction than the FSRP, indicating that recalibrated China-PAR stroke risk equations might be appropriate tools for risk assessment and primary prevention of stroke in China.

[Multiple linear regression models with natural logarithmic transformations of variables]

In general, the application conditions of linear regression models could be met after the natural logarithmic transformation of data. From the practical perspective, this paper introduced the linear regression models with natural logarithmic transformation of independent variable, dependent variable, and both independent and dependent variables in detail. The paper illustrated why the equation and coefficients could not be directly explained after the natural logarithmic transformation of data. The percentage changes of X and/or Y were applied to elaborate the principle and method for the explanation of the equation and coefficients. Three examples were used to fit simple linear models with natural logarithmic transformation of independent, dependent, and both independent and dependent variables and the results of theses models were explained in detail.

[Effects and mechanism of rat epidermal stem cells treated with exogenous vascular endothelial growth factor on healing of deep partial-thickness burn wounds in rats]

Objective: To explore the effects and mechanism of rat epidermal stem cells (ESCs) that were treated with exogenous vascular endothelial growth factor (VEGF) on the healing of deep partial-thickness burn wounds in rats. Methods: ESCs were isolated and cultured from the trunk skin of a 3-month-old female Sprague-Dawley (SD) rat. The third passage of cultured cells in the logarithmic growth phase was used in experiments (1)-(3). (1) The cells were routinely cultured in keratinocytes-specified serum-free medium (K-SFM) (the same routine culture condition below). The morphology of cells cultured for 3 and 5 days was observed under the inverted optical microscope. (2) After 24 hours in routine culture, the expression of cell surface markers CD44, CD45, CD11b, and CD11c was detected by flow cytometer, with triplicate samples. (3) Four batches of cells were collected, and each batch was divided into VEGF group or blank control group according to the random number table. The cells in blank control group were routinely cultured, while the cells in VEGF group were cultured in K-SFM containing VEGF in the final mass concentration of 10 ng/mL. The protein expressions of cytokeratin 19 (CK19) and CK10 in cells cultured for 10 days were detected by Western blotting. The Nanog mRNA expression in cells cultured for 0 (immediately), 2, 4, 6, 8, and 10 day (s) was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The absorbance value was detected with cell counting kit-8 in cells cultured for 2, 4, 6, 8, and 10 days. The clone number of more than 50 cells was observed and counted under the optical microscope in cells cultured for 10 days, and the cell colony formation rate was calculated. Three samples at each time point was analysed. (4) Thirty-six 3-month-old SD rats (either male or female) were used for the study, and two deep partial-thickness burn wounds (10 mm in diameter) were created in each rat by pressing a 100 ℃ electric iron plate on symmetric dorsal side. According to the random number table, the injured rats were divided into VEGF+ ESCs group, ESCs alone group, and blank control group, with 12 rats and 24 wounds in each group. From 0 (immediately) to 2 day (s) after injury, 20 μL phosphate buffer solution (PBS) was injected into each wound in the three groups in one time, once a day, with the solution in VEGF+ ESCs group containing 0.8×10(6) cells/mL of ESCs treated by 10 ng/mL VEGF for 10 days, the solution in ESCs alone group containing 0.8×10(6) cells/mL of ESCs without any treatment, and the solution in blank control group being PBS only. On post first injection day (PFID) 0 (immediately), 3, 7, and 14, three rats from each group were taken respectively according to the random number table for wound healing assessment, and the wound healing rates on PFID 3, 7, and 14 were calculated. The mice at each time point were sacrificed with wound tissue harvested for histology, and the skin structure was observed by hematoxylin-eosin staining. Data were statistically analyzed with independent sample t test, analysis of variance for factorial design, least significant difference test, and Bonferroni correction. Results: (1) By day 3 in culture, cells distributed in slowly-growing clusters. By day 5, the clusters were large and round, in which the cells mainly with large and round nuclei and little cytoplasm were observed. The above results were consistent with the morphological characteristics of ESCs. (2) The positive expression rate of CD44 was (94.3±1.2) %, and the expressions of CD45, CD11b, and CD11c were negative. The cells were confirmed as ESCs. (3) Compared with those of blank control group, the protein expression of CK19 in the cells of VEGF group was significantly increased after 10 days in culture (t=3.756, P<0.05), while the protein expression of CK10 was significantly decreased (t=3.149, P<0.05). Compared with those of blank control group, the Nanog mRNA expression in the cells cultured for 0 and 2 day (s) and absorbance values of the cells cultured for 2 and 4 day (s) were not significantly changed in VEGF group (t=0.58, 0.77, 0.53, 3.02, P>0.05), while the Nanog mRNA expression in the cells cultured for 4, 6, 8, and 10 days and absorbance values of the cells cultured for 6, 8, and 10 days were significantly increased in VEGF group (t=6.34, 5.00, 5.58, 4.61, 5.65, 10.78, 15.51, P<0.01). After 10 days in culture, the cell colony-forming rate in VEGF group was (56.4±1.3) %, significantly higher than (31.5±1.3) % of blank control group (t=13.96, P<0.01). (4) The burn wounds of rats in the three groups were confined to the superficial dermis of the skin on PFID 0. On PFID 3, normal skin tissue at wound margins slightly contracted in the rats of VEGF+ ESCs group, which was earlier than that in the other two groups. On PFID 7, the newly generated epidermis covered most parts of the rat wounds in VEGF+ ESCs group, and some of the epithelium crawled around the rat wounds in ESCs alone group, but no obvious epithelialization was observed in the rat wounds in blank control group. On PFID 14, the rat wounds in VEGF+ ESCs group were basically healed, while some parts of the rat wounds were unhealed in ESCs alone group, and most parts of the rat wounds were unhealed in blank control group. On PFID 3, the wound healing rates of rats in the three groups were similar (P>0.05). On PFID 7 and 14, the wound healing rates of rats in ESCs alone group, respectively (26.0±2.0) % and (64.4±4.7) %, were obviously higher than (12.4±1.1) % and (29.1±3.3) % of blank control group (P<0.01), all of which were obviously lower than (41.0±2.4) % and (91.3±3.5) % of VEGF+ ESCs group (P<0.01). On PFID 3, infiltration of a large number of inflammatory cells were observed in the rat wounds in VEGF+ ESCs group, which was earlier than those in the other two groups. On PFID 7, a large number of endothelial cells were observed in the rat wounds in VEGF+ ESCs group, while proliferation of a few endothelial cells were observed in the rat wounds in ESCs alone group, and a large number of inflammatory cells infiltrated the rat wounds in blank control group. On PFID 14, the newly generated epidermal cells covered nearly all the rat wounds in VEGF+ ESCs group and most parts of the rat wounds in ESCs alone group, while a large number of endothelial cells were observed and the newly generated epidermal cells covered some parts of the rat wounds in blank control group. Conclusions: ESCs of rats treated with exogenous VEGF can promote the healing of deep partial-thickness burn wounds in rats, which may be related to VEGF's roles in promoting the proliferation of ESCs and reducing its differentiation level, so as to maintain the potency of stem cells.

[Years of potential life lost due to premature death of cardiovascular diseases among residents in Suzhou from 1987 to 2017]

From 1987 to 2017, cardiovascular disease (CVD) had been ranking the first cause of death in Suzhou, and the mortality rate showed an upward trend annual percentage changes (APC=0.62%, P=0.001), while the standardized mortality rate showed a downward trend (APC=-2.65%, P<0.001). The probability of premature death of CVD declined consistently from 7.06% in 1987 to 2.00% in 2017 (APC=-4.45%, P<0.001). When the life expectancy was set at 70, the potential years of life lost rate (PYLLR) decreased from 6.35‰ in 1987 to 3.30‰ in 2017, and the standardized PYLLR decreased from 7.30‰ to 2.68‰. When the life expectancy was set at 75, the PYLLR decreased from 10.12‰ to 5.19‰, and the standardized PYLLR decreased from 11.44‰ to 3.88‰. With the increase of years, all PYLLR and standardized PYLLR showed a significantly downward trend (APC=-2.51%--3.89%, P<0.001).

Distinct effects of antihypertensives on depression in the real-world setting: A retrospective cohort study

BACKGROUND

Evidence is increasing that pathways of antihypertensives may have a role in the pathogenesis of depression. However, how the class of antihypertensives affects depression risk remains unclear.

METHODS

The effects of different classes of antihypertensives on depression were explored using an insurance database in Beijing, China. Antihypertensives in our study included calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), and diuretics (DIUs). Those initially treated with only one class of antihypertensives were included. Stratified analysis was conducted for demographic characteristics, comorbidities, and statin prescriptions.

RESULTS

In total, 181,709 newly detected hypertension patients were included. The median follow-up period was 4.33 years and 19,030 participants were with depression by the end. After adjusting for covariates, the incidence density (95% confidence interval, CI) of depression in the BB, ACEI, DIU, CCB, and ARB groups was 3.16 (2.98-3.33), 3.10 (2.91-3.29), 2.70 (2.45-2.94), 2.67 (2.53-2.81), and 2.30 (2.16-2.43) per 100 person-years, respectively. Compared with ARB group, the hazard ratio (95% CI) of depression for BB, ACEI, DIU, and CCB group was 1.37 (1.32-1.43), 1.35 (1.28-1.42), 1.17 (1.08-1.27), and 1.16 (1.12-1.21), respectively. Stratified analysis suggested the highest depression ID remained within the BB or ACEI group.

LIMITATIONS

Detailed clinical information was unavailable, which may introduce bias. Patients on monotherapy as initial treatment were included and caution is needed for extrapolation.

CONCLUSIONS

Compared with ARBs, there may be a class effect of other antihypertensives on the risk of depression.

[Overview of logistic regression model analysis and application]

Logistic regression is a kind of multiple regression method to analyze the relationship between a binary outcome or categorical outcome and multiple influencing factors, including multiple logistic regression, conditional logistic regression, polytomous logistic regression, ordinal logistic regression and adjacent categorical logistic regression. This paper illustrates the basic principle, independent variable selection and assignment, applied condition, model evaluation and diagnosis for multiple logistic regression model. Moreover, the principle and application for polytomous logistic regression and ordinal logistic regression models were also introduced. By providing SAS codes and detailed explanations of the result for an example of obesity, readers could be able to better understand logistic regression model, and apply this method correctly to their research and daily work, so as to improve their capacity of the data analysis.

[Study on the current status of postgraduates training in public health and preventive medicine in China in 2016]

To investigate the current status of postgraduates training in public health and preventive medicine in China. In this study, a questionnaire survey was conducted among directors of enrollment and teaching in 22 universities with postgraduate admission qualifications in corresponding disciplines nationwide. In 2016, full-time postgraduates were mainly academic masters. In addition to the graduate entrance examination, the common enrollment mode in colleges was to enroll a high qualified student with recommendations from relevant experts or institutions and an exemption from entrance examination (20/22). The emphasis on training contents between academic and public health master was different. Currently, the scale of public health postgraduate enrollment in public health and preventive medicine in China is stable, and the training program is reasonable, but there is an issue of monotonous model and uneven distribution of enrollment.