Novel variant infectious bursal disease virus diminishes FAdV-4 vaccination and enhances pathogenicity of FAdV-4.

Infectious bursal disease virus (IBDV) caused an acute and highly contagious infectious disease characterized by severe immunosuppression, causing considerable economic losses to the poultry industry globally. Although this disease was well-controlled under the widely use of commercial vaccines in the past decades, the novel variant IBDV strains emerged recently because of the highly immunized-selection pressure in the field, posting new threats to poultry industry. Here, we reported novel variant IBDV is responsible for a disease outbreak, and assessed the epidemic and pathogenicity of IBDV in this study. Moreover, we constructed a challenge model using Fowl adenovirus serotype 4 (FAdV-4) to study on the immunosuppressive effect. Our findings underscore the importance of IBDV surveillance, and provide evidence for understanding the pathogenicity of IBDV.

The attenuated live vaccine strain W2512 provides protection against novel variant infectious bursal disease virus.

Infectious bursal disease virus (IBDV) causes an acute and highly contagious infectious disease characterized by severe immunosuppression, causing great economic losses to the poultry industry globally. Over the past 30 years, this disease has been well controlled through vaccination and strict biosafety measures. However, novel variant IBDV strains have emerged in recent years, posing a new threat to the poultry industry. Our previous epidemiological survey showed that few novel variant IBDV strains had been isolated from chickens immunized with the attenuated live vaccine W2512-, suggesting that this vaccine is efficacious against novel variant strains. Here, we report the protective effect of the W2512 vaccine against novel variant strains in SPF chickens and commercial yellow-feathered broilers. We found that W2512 causes severe atrophy of the bursa of Fabricius in SPF chickens and commercial yellow-feathered broilers, induces high levels of antibodies against IBDV, and protects chickens from infection with the novel variant strains via a placeholder effect. This study highlights the protective effect of commercial attenuated live vaccines against the novel IBDV variant and provides guidance for the prevention and control of this disease.

Pathogenicity and transmissibility studies on live attenuated duck enteritis virus vaccine in non-target species.

In the second half of 2021, a highly pathogenic case occurred in a mixed chicken and duck family farm in Guangdong, China. After the duck flocks were immunized with live attenuated duck enteritis virus vaccine (live attenuated DEV vaccine), the chickens of the same farm showed clinical symptoms similar to duck enteritis, such as pericardial effusion, hepatic hemorrhagic spots, kidney enlargement, and intestinal bleeding, with mass mortality. The infection model of target animal tested, as well as the non-target species, was established according to the risk of live attenuated DEV vaccine and transmission in chickens. Live attenuated DEV vaccine was initially replicated in host animals, released the virus, and effectively colonized in the common environment, according to birds challenged experiments. There was evidence to suggest the mode of transmission of duck enteritis virus, and horizontal transmission is the main route of DEV transmission. In addition, high levels of virus titer were detected in chicken embryos and different tissues of SPF chickens. Different degrees of pathological damage occurred in the tissue of chickens. After the SPF chickens were inoculated with live attenuated DEV vaccine, different degrees of virulence were exhibited, pointing to a potential risk to other domestic bird species.

Standard diffusion-weighted, diffusion kurtosis and intravoxel incoherent motion MR imaging of the whole placenta: a pilot study of volumetric analysis.

Background: Using magnetic resonance imaging (MRI) to explore the changes in microvascular perfusion fraction and the heterogeneity of the placenta during pregnancy. Methods: We retrospectively reviewed 24 patients with normal pregnancies who underwent standard diffusion-weighted, diffusion kurtosis, and intravoxel incoherent motion MRI. The mean, minimum and maximum parameters including the apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard diffusion-weighted imaging (DWI), the diffusion coefficient (MD) and diffusion kurtosis (MK) from diffusion kurtosis imaging (DKI), and the pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f) from intravoxel incoherent motion MR imaging (IVIM) were calculated from the whole placenta volumetric analysis and correlated with gestational age (GA) and volume of the placenta. Results: A significant positive correlation was found between eADC mean, eADC max, MK mean, MK max, the volume of the whole placenta, and GA, and a negative correlation was found between ADC mean, ADC min, MD min, D mean, D min, D* min and GA. The f mean and MK max values positively correlated with the volume of the whole placenta. Conclusions: eADC mean, eADC max, MK mean, MK max values increased with GA, while ADC mean, ADC min, MD min, D mean, D min, D* min decreased with GA. Secondly, the f mean and MK max also increased with placental volume. These results suggest the potential of diffusion and perfusion parameters to evaluate the placenta during its development using different DWI models.

Monoexponential, biexponential and diffusion kurtosis MR imaging models: quantitative biomarkers in the diagnosis of placenta accreta spectrum disorders.

BACKGROUND: To investigate the diagnostic value of monoexponential, biexponential, and diffusion kurtosis MR imaging (MRI) in differentiating placenta accreta spectrum (PAS) disorders. METHODS: A total of 65 patients with PAS disorders and 27 patients with normal placentas undergoing conventional DWI, IVIM, and DKI were retrospectively reviewed. The mean, minimum, and maximum parameters including the apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard DWI, diffusion kurtosis (MK), and mean diffusion coefficient (MD) from DKI and pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) from IVIM were measured from the volumetric analysis and compared between patients with PAS disorders and patients with normal placentas. Univariate and multivariated logistic regression analyses were used to evaluate the value of the above parameters for differentiating PAS disorders. Receiver operating characteristics (ROC) curve analyses were used to evaluate the diagnostic efficiency of different diffusion parameters for predicting PAS disorders. RESULTS: Multivariate analysis demonstrated that only D mean and D max differed significantly among all the studied parameters for differentiating PAS disorders when comparisons between accreta lesions in patients with PAS (AP) and whole placentas in patients with normal placentas (WP-normal) were performed (all p < 0.05). For discriminating PAS disorders, a combined use of these two parameters yielded an AUC of 0.93 with sensitivity, specificity, and accuracy of 83.08, 88.89, and 83.70%, respectively. CONCLUSION: The diagnostic performance of the parameters from accreta lesions was better than that of the whole placenta. D mean and D max were associated with PAS disorders.

Dose Prediction Models Based on Geometric and Plan Optimization Parameter for Adjuvant Radiotherapy Planning Design in Cervical Cancer Radiotherapy.

The prediction of an additional space for the dose sparing of organs at risk (OAR) in radiotherapy is still difficult. In this pursuit, the present study was envisaged to find out the factors affecting the bladder and rectum dosimetry of cervical cancer. Additionally, the relationship between the dose-volume histogram (DVH) parameters and the geometry and plan dose-volume optimization parameters of the bladder/rectum was established to develop the dose prediction models and guide the planning design for lower OARs dose coverage directly. Thirty volume modulated radiation therapy (VMAT) plans from cervical cancer patients were randomly chosen to build the dose prediction models. The target dose coverage was evaluated. Dose prediction models were established by univariate and multiple linear regression among the dosimetric parameters of the bladder/rectum, the geometry parameters (planning target volume (PTV), volume of bladder/rectum, overlap volume of bladder/rectum (OV), and overlapped volume as a percentage of bladder/rectum volume (OP)), and corresponding plan dose-volume optimization parameters of the nonoverlapping structures (the structure of bladder/rectum outside the PTV (NOS)). Finally, the accuracy of the prediction models was evaluated by tracking d = (predicted dose-actual dose)/actual in additional ten VMAT plans. V 30, V 35, and V 40 of the bladder and rectum were found to be multiple linearly correlated with the relevant OP and corresponding dose-volume optimization parameters of NOS (regression R 2 > 0.99, P < 0.001). The variations of these models were less than 0.5% for bladder and rectum. Percentage of bladder and rectum within the PTV and the dose-volume optimization parameters of NOS could be used to predict the dose quantitatively. The parameters of NOS as a limited condition could be used in the plan optimization instead of limiting the dose and volume of the entire OAR traditionally, which made the plan optimization more unified and convenient and strengthened the plan quality and consistency.

Meta-Analysis for Social Support Degree of Kidney Transplant Recipients: Evidence from China.

Social support refers to the subjective and (or) objective influence of various social relationships on individuals, which has a certain influence on the negative emotions of the kidney transplant patients. But there are still significant differences among various studies, so we performed a meta-analysis to analyze the social support degree of kidney transplant recipients. This article searched and selected the relevant cross-sectional surveys from PubMed, Embase, VIP, CNKI, Wanfang, and CBM databases according to the inclusion and exclusion criteria and used the STROBE list combined with the observational research quality evaluation tools of Sanderson to conduct the quality appraisal. The "meta" and "metaphor" packages of the R software version 3.5.1 were used for the meta-analysis. A total of 17 studies with 2697 patients were included. The total scores of the social support and objective support of the renal transplant patients were abundant after the operation, indicating that the economic, physical, and emotional supports from the family, society, and the official organization are accepted. But the subjective support and support utilization degree were general. The support utilization was different among different genders, and female patients were lower than the males. In particular, the female patients relatively presented autism and the social support utilization degree was low. Medical staffs are needed to join the family, hospital, and society to create favorable conditions and improve the social support system and the utilization degree of the social support, thereby promoting the physical and mental health development of the patients.

A preferred patient decubitus positioning for magnetic resonance image guided online adaptive radiation therapy of pancreatic cancer.

BACKGROUND AND PURPOSE: In radiotherapy (RT) for pancreatic cancer, the dose to adjacent organs-at-risk (OAR) often limits the delivery of curative dose. This work aimed to find a body decubitus position that would lead to increased separation between the duodenum and pancreatic head. MATERIALS AND METHODS: Abdominal magnetic resonance images (MRI) of 11 healthy volunteers were acquired using a 1.5T MR-Linac for supine, left decubitus and right decubitus body positions. The geometry changes between different body positions were measured using Hausdorff Distance (HD) and overlap volume. RT plans were created on the MRIs. Commonly used dose-volume parameters (DVP), e.g., V40Gy - volume received at least 40 Gy, for OARs were compared for the three body positions. RESULTS: The average of maximum HD between the duodenum and pancreatic head for all the cases was 4.0 ± 3.1 mm for supine, 7.3 ± 4.4 mm for left and 3.3 ± 1.4 mm for right positions (P < 0.01). The DVPs of the duodenum (e.g., V20Gy, V45Gy) for the left position were lower than those for the supine and right positions (P < 0.01). The right decubitus led to the highest duodenum DVPs. On average, the highest dose escalation was increased from 69 ± 4 Gy to 74 ± 5 Gy (P = 0.002) if body position was changed from supine to left decubitus. CONCLUSION: The left decubitus increased the separation between duodenum and pancreas head, improving OAR sparing in RT for pancreatic cancer and allowing safer dose escalations to the tumor. The left decubitus positioning with proper immobilization could be adopted for MRI-guided adaptive RT.

Dosimetric comparisons of IMRT planning using MCO and DMPO techniques.

The goal of this study was to evaluate the use of multi-criteria optimization (MCO) in the planning and optimization of intensity-modulated radiotherapy (IMRT). Twenty (20) IMRT patients (ten (10) with prostate cancer and ten (10) with lung cancer) were randomly selected. The treatment plans for these patients were designed using direct machine parameter optimization (DMPO). Based on these plans, new plans were designed using multi-criteria optimization (MCO), keeping the optimization objectives and constraints unchanged. Comparisons were made between the new plans, which were based on MCO and DMPO, including the dose distribution, dose volume histogram (DVH), the optimization time and the number of monitor units (MUs). The plan designed using both optimization approaches satisfied all clinical requirements. For similar or better target coverage, the rectum, bladder and small bowel were better protected using MCO than when using DMPO. Additionally, MCO reduced the time for optimization by 58% on average, whereas the MUs increased the time for optimization by 32% on average for prostate cancer. For lung cancer cases, the entire lung, heart and spinal cord were better protected using MCO compared to DMPO. Similarly, MCO reduced the time for optimization by 59% on average, whereas the MUs increased the time for optimization by 11% on average. Compared to DMPO, MCO reduces the dose of the organs at risk (OAR) and shortens the time required for optimization.