[Preliminary practice of multidisciplinary cooperative vaccination management model for pediatric patients with hematological and oncological diseases]

Objective: To preliminarily establish the multidisciplinary cooperative vaccination management model for pediatric patients with hematological and oncological diseases, and to explore its feasibility. Methods: In this prospective study a total of 150 children with hematological and oncological diseases visited immunization clinic of Shanghai Children's Medical Center from March 2017 to August 2018 were enrolled in this study. After establishing the multidisciplinary team, designing vaccination plan, staff training, implementation and quality control, a multidisciplinary immunization clinic was set up and the vaccination plan were implemented. The implementation rate of vaccination immunization, the HBsAb level and serum hepatitis B surface antibody (HBsAb) level before and after treatment, the HBsAb level and serum immunoglobulin G antibody (IgG) levels of measles, mumps, rubella (MMR) before and 6 months after immunization, the vaccine-related adverse reactions were assessed prospectively. Chi-square test or Fisher exact test was used to compare the differences of antibody level. Results: A total of 124 cases had been vaccinated as planned, with a coverage rate of 82.7%. Among these cases, the difference of HBsAb positive rate before and after treatment was significant (62.9% (78/124) vs.13.7% (17/124), χ²= 63.489, P<0.01). In 64 cases that completed three doses of hepatitis B immunization, there was a significant difference in HBsAb positive rate before and 6 months after immunization (6.3% (4/64) vs. 98.4% (63/64), P<0.01). In 40 cases that completed MMR immunization, the IgG antibody positive rate for measles (22.5% (9/40) vs. 82.5% (33/40), χ²=31.746,P<0.01), mumps (22.5% (9/40) vs.82.5% (33/40), χ²=28.872,P<0.01), rubella (25.0% (10/40) vs.62.5% (25/40), χ²=11.429, P<0.01) before and 6 months after immunization were significantly different. Of the 421 doses of immunization, 25 (5.9%) doses reported controlled systemic or local adverse event. Conclusions: The immunization of pediatric patients with hematological and oncological diseases is of great importance. The newly-developed multidisciplinary cooperation immunization model for Chinese children with hematological and oncological diseases is feasible, and the immunization protocol is safe and has a certain effect.

Cytomegalovirus-Specific Immunity Recovers More Slowly after Cord Blood Transplantation Compared with Matched Sibling Donor Allogeneic Transplantation

BACKGROUND

Rapid quantitative recovery of NK cells but slower recovery of T-cell subsets along with frequent viral infections are reported after umbilical cord blood (UCB) compared with matched sibling donor (MSD) hematopoietic cell transplantation (HCT). However, it remains unclear whether increased propensity for viral infections is also a result of slower recovery of virus-specific immunity after UCB as compared to MSD HCT.

OBJECTIVES

We examined the differences in the function of virus-specific peripheral blood mononuclear cells (PBMC) after UCB (N=17) vs. MSD (N=9) using previously collected patient blood samples at various time points after HCT.

METHODS

Interferon-gamma (IFN-γ) enzyme-linked immune absorbent spot (ELISpot) assay was used to quantify the PBMC frequencies that secrete IFN-γ in response to 11 immunopeptides from 5 common viruses. We included the patients who received the same reduced intensity conditioning regimen without ATG, no systemic glucocorticoids and had no relapse or acute/chronic graft-versus-host disease within 1 year after HCT.

RESULTS

The CMV-reactive PBMC frequencies were higher in CMV seropositive vs. seronegative patients after HCT. Among CMV seropositive patients, the frequency of CMV-reactive PBMC was lower after UCB compared to MSD throughout one year of HCT. We observed no differences in virus-specific PBMC responses towards HHV6, EBV, BK, and adenovirus antigens between UCB and MSD.

CONCLUSION

Our data demonstrate that the reconstitution of CMV-specific immunity is slower in CMV seropositive recipients of UCB vs. MSD HCT in contrast to other viruses which had similar recoveries. These study findings support implementation of more potent prophylactic strategies for preventing CMV reactivation in CMV seropositive patients receiving UCB HCT.

Effects of Expanded Graphite, Aluminum Hydroxide, and Kaolin on Flame Retardancy and Smoke Suppression of Polyurethane Composites

Polyurethane is a widely used polymer that has good abrasion resistance and low-temperature resistance. However, polyurethane composite materials are highly inflammable and thus require the use of flame retardants. This study selected green and environment-friendly flame retardants such as expanded graphite, aluminum hydroxide, and kaolin to be used as individual or paired retardants to produce polyurethane composites. By analyzing the potential and mechanical properties of the polyurethane composites, it was found that the composite material with the flame retardant composed of graphite and modified kaolin had better flame retardancy, smoke suppression performance, and high thermal stability.

[Efficacy and safety of hepatitis B re-vaccination in children after completion of chemotherapy and(or) hematopoietic stem cell transplantation]

Objective: To assess the anti-hepatitis B surface antibody (HBsAb) titers in children after completion of chemotherapy and (or) hematopoietic stem cell transplantation (HSCT), evaluate the efficacy and safety of the current hepatitis B re-vaccination schedule. Methods: A total of 239 children who completed their chemotherapy and (or) HSCT and visited the vaccination clinic of Shanghai Children's Medical Center from March 2017 to July 2019 were enrolled in this study. According to the previous diseases, patients were divided into leukemia group (85 cases), lymphoma group (30 cases), solid tumor group (49 cases) and non-malignant hematological disease group (75 cases). According to the treatment of previous diseases, the patients were divided into chemotherapy group (126 cases), HSCT group (89 cases) and chemotherapy plus HSCT group (24 cases). HBsAb titers were assessed both at the time of diagnosis and after completion of treatment and some children who were HBsAb seronegative were re-vaccinated with 3 doses of hepatitis B vaccine, the vaccine-related adverse reactions were monitored. HBsAb titers were measured again one month after the completion of inoculation. HBsAb titers were defined as negative at levels <10 U/L and positive at ≥ 10 U/L. Chi-square test or Fisher exact test was used to compare the difference of negative conversion rate of hepatitis B antibody between groups, and Logistic regression was used to explore the risk factors of hepatitis B antibody negative conversion. Results: Among 239 patients, there were 143 males and 96 females. At the time of diagnosis, 179 patients (74.9%) were HBsAb seropositive and 60 patients (25.1%) were HBsAb seronegative. After completion of chemotherapy and (or) HSCT, 133 of 179 children with HBsAb seropositive (74.3%) at diagnosis became HBsAb seronegative. Univariate analysis showed significant differences at the negative conversion rates of HBsAb between different disease groups (χ²=10.211，P=0.015), different treatments groups (χ²=14.899，P<0.01) and different HBsAb titers groups before treatment (χ²=32.117，P<0.01). Logistic regression showed that HSCT (chemotherapy group as the reference, odds ratio (OR）=2.999, 95% confidence interval (CI) 1.276-7.050，P=0.012) and HBsAb titers<328.2 U/L before treatment (HBsAb titers≥328.2 U/L group as the reference, OR=6.397， 95% CI3.159-12.954，P<0.01) were risk factors for negative conversion of HBsAb. Among 48 patients whose HBsAb was seronegative after completion of chemotherapy and (or) HSCT and re-vaccinated with hepatitis B vaccine, 47 (97.9%) cases became HBsAb seropositivie. No serious adverse effects or complications were reported among these patients. Conclusions: After completion of chemotherapy and (or) HSCT, most children completely lose their protective humoral immunity against hepatitis B. Hepatitis B re-vaccination schedule can be efficiently and safely applied in those patients.

2D shear wave elastography combined with age and serum biomarkers prior to kasai surgery predicts native liver survival of biliary atresia infants

BACKGROUND

The prognosis of patients with biliary atresia (BA) after Kasai portoenterostomy (KPE) varies, and precisely predicting the outcomes of KPE before surgery is still challenging.

METHODS

A total of 158 patients who underwent KPE in our hospital were included in this study. The patients in the training cohort were recruited from January 2012 to October 2017 (n = 118), and then, those in the validation cohort were recruited from November 2017 to April 2019 (n = 40). Combined nomogram models were developed based on two-dimensional shear wave elastography (2D SWE) values and other biomarkers. The utility of the proposed models was evaluated by C-index.

RESULTS

2D SWE played a potentially important role in predicting native liver survival (NLS) of BA patients with a C-index of 0.69 (0.63 to 0.75) in the training cohort and 0.76 (0.67 to 0.85) in the validation cohort. The nomogram A based on 2D SWE values, age, gamma-glutamyl transferase (GGT) and aspartate aminotransferase-to-platelet ratio (APRI) had a better C-index in the training cohort [0.74 (0.68-0.80) vs. 0.66 (0.60-0.73), P = 0.017] and in the validation cohort [0.78 (0.70-0.86) vs. 0.60 (0.49-0.71), P = 0.002] than the nomogram B (without 2D SWE). Using risk score developed from nomogram A, we successfully predicted 88.0% (22/25) of patients in the training cohort and 75.0% (9/12) in the validation cohort to have survival time of less than 12 months after KPE.

CONCLUSION

The combined nomogram model based on 2D SWE values, age, GGT and APRI prior to KPE can effectively predict NLS in BA infants.

Efficacy of a novel intradermal Lawsonia intracellularis vaccine in pigs against experimental infection and under field conditions

Background

The efficacy of a novel inactivated intradermal Lawsonia intracellularis vaccine, Porcilis® Lawsonia ID, was evaluated in two experimental vaccination-challenge studies and under field conditions on a farm with a history of recurrent acute ileitis. In addition, the efficacy of the vaccine was compared to that of a commercially available live attenuated vaccine. The novel inactivated vaccine consists of a freeze-dried antigen fraction that is dissolved just prior to use in either the adjuvant or in Porcilis® PCV ID; an existing intradermal vaccine against porcine Circovirus type 2. In the two experimental vaccination-challenge studies, groups of 25 piglets were vaccinated once at 3 weeks of age or left unvaccinated as challenge control. Vaccines tested were Porcilis® Lawsonia ID as standalone (study 1) or in associated mixed use with Porcilis® PCV ID (study 2) and an orally administered commercially available live vaccine (study 1). The pigs were challenged with virulent L. intracellularis at 4 weeks (study 1) or 21 weeks (study 2) after vaccination. Post-challenge, the pigs were evaluated for clinical signs, average daily weight gain, shedding and macroscopic as well as microscopic immuno-histological ileum lesion scores. In the field study, the mortality and key performance parameters were evaluated over a period of 8 months.

Results

The results of the two experimental vaccination-challenge studies showed that Porcilis® Lawsonia ID as single vaccine or in associated mixed use with Porcilis® PCV ID, induced statistically significant protection against experimental L. intracellularis infection, 4 weeks or 21 weeks after vaccination. This was demonstrated by lower clinical scores, improved weight gain, reduction of L. intracellularis shedding and reduction of macroscopic as well as microscopic ileum lesion scores when compared to the controls. The protection induced was superior to that of the commercially available live vaccine. In the field study Porcilis® Lawsonia ID was highly efficacious in reducing L. intracellularis associated mortality and improving key production parameters.

Conclusion

The results support that this new intradermal vaccine is efficacious against L. intracellularis and may be used in associated mixed use with Porcilis® PCV ID.

[A multicentric study on clinical characteristics and antibiotic sensitivity in children with methicillin-resistant Staphylococcus aureus infection]

Objective: To investigate the clinical characteristics of pediatric methicillin-resistant Staphylococcus aureus (MRSA) infection and the antibiotic sensitivity of the isolates. Methods: The clinical data of children with MRSA infection and antibiotic sensitivity of the isolates from 11 children's hospitals in Infectious Diseases Surveillance of Paediatrics (ISPED) group of China between January 1, 2018 and December 31, 2018 were collected retrospectively. The children's general condition, high-risk factors, antimicrobial therapy and prognosis, differences in clinical disease and laboratory test results between different age groups, and differences of antibiotic sensitivity between community-acquired (CA)-MRSA and hospital-acquired (HA)-MRSA were analyzed. The t test and Wilcoxon rank sum test were used for statistical analysis of the quantitative data and Chi-square test were used for comparison of rates. Results: Among the 452 patients, 264 were males and 188 were females, aged from 2 days to 17 years. There were 233 cases (51.5%) in the ≤1 year old group, 79 cases (17.5%) in the>1-3 years old group, 29 cases (6.4%) in the >3-5 years old group, 65 cases (14.4%) in the >5-10 years old group, and 46 cases (10.2%) in the>10 years old group. The main distributions of onset seasons were 55 cases (12.2%) in December, 47 cases (10.4%) in February, 46 cases (10.2%) in November, 45 cases (10.0%) in January, 40 cases (8.8%) in March. There were 335 cases (74.1%) CA-MRSA and 117 (25.9%) cases HA-MRSA. Among all cases, 174 cases (38.5%) had basic diseases or long-term use of hormone and immunosuppressive drugs. During the period of hospitalization, 209 cases (46.2%) received medical interventions. There were 182 patients (40.3%) had used antibiotics (β-lactams, glycopeptides, macrolides, carbapenems, oxazolones, sulfonamides etc) 3 months before admission. The most common clinical disease was pneumonia (203 cases), followed by skin soft-tissue infection (133 cases), sepsis (92 cases), deep tissue abscess (42 cases), osteomyelitis (40 cases), and septic arthritis (26 cases), suppurative meningitis (10 cases). The proportion of pneumonia in the ≤1 year old group was higher than the >1-3 years old group,>3-5 years old group,>5-10 years old group,>10 years old group (57.5% (134/233) vs. 30.4% (24/79), 31.0% (9/29), 38.5% (25/65), 23.9% (11/46), χ(2)=17.374, 7.293, 7.410, 17.373, all P<0.01) The proportion of skin and soft tissue infections caused by CA-MRSA infection was higher than HA-MRSA (33.4% (112/335) vs. 17.9% (21/117), χ(2)=10.010, P=0.002), and the proportion of pneumonia caused by HA-MRSA infection was higher than CA-MRSA (53.0% (62/117) vs. 42.1% (141/335), χ(2)=4.166, P=0.041). The first white blood cell count of the ≤1 year old group was higher than that children > 1 year old ((15±8)×10(9)/L vs. (13±7)×10(9)/L, t=2.697, P=0.007), while the C-reactive protein of the ≤1 year old group was lower than the 1-3 years old group,>5-10 years old group,>10 years old group (8.00 (0.04-194.00) vs.17.00 (0.50-316.00), 15.20 (0.23-312.00), 21.79(0.13-219.00) mg/L, Z=3.207, 2.044, 2.513, all P<0.05), there were no significant differences in procalcitonin (PCT) between different age groups (all P>0.05). After the treatment, 131 cases were cured, 278 cases were improved, 21 cases were not cured, 12 cases died, and 10 cases were abandoned. The 452 MRSA isolates were all sensitive to vancomycin (100.0%), linezolid (100.0%), 100.0% resistant to penicillin, highly resistant to erythromycin (85.0%, 375/441), clindamycin (67.7%, 294/434), less resistant to sulfonamides (5.9%, 23/391), levofloxacin (4.5%, 19/423), gentamicin (3.2%, 14/438), rifampicin (1.8%, 8/440), minocycline (1.1%, 1/91). The antimicrobial resistance rates were not significantly different between the CA-MRSA and HA-MRSA groups (all P>0.05). Conclusions: The infection of MRSA is mainly found in infants under 3 years old. The prevalent seasons are winter and spring, and MRSA is mainly acquired in the community. The main clinical diseases are pneumonia, skin soft-tissue infection and sepsis. No MRSA isolate is resistant to vancomycin, linezolid. MRSA isolates are generally sensitive to sulfonamides, levofloxacin, gentamicin, rifampicin, minocycline, and were highly resistant to erythromycin and clindamycin. To achieve better prognosis. clinicians should initiate anti-infective treatment for children with MRSA infection according to the clinical characteristics of patients and drug sensitivity of the isolates timely and effectively.

Attenuating the abnormally high expression of AEBP1 suppresses the pathogenesis of childhood acute lymphoblastic leukemia via p53-dependent signaling pathway

OBJECTIVE

This study aimed to explore the candidate genes and their potential mechanism in childhood acute lymphoblastic leukemia (cALL).

MATERIALS AND METHODS

Differentially expressed genes (DEGs) were screened from GSE67684 (treatment), GSE28460 (relapse), and GSE60926 (relapse). The expression of AEBP1 at different stages of cALL was analyzed followed by functional enrichment analysis of its co-expressed genes. Expression of AEBP1 was determined in different leukemia cell lines and knocked down in Jurkat cells. Cell behaviors as well as the expression of p53, Bax, and Bcl-2 were also evaluated after silencing AEBP1 in Jurkat cells.

RESULTS

Two clusters: Profile 1 (downward) and Profile 26 (upward) were identified in GSE67684, and 53 Profile 1-specific DEGs were identified compared with DEGs in GSE28460 and GSE60926. AEBP1 was one of these genes and was significantly downregulated after treatment but upregulated in relapse samples. Functional enrichment analysis revealed that AEBP1 co-expressed genes were significantly enriched in GO terms including immune response, blood coagulation etc. and in the hematopoietic cell lineage and PI3K/Akt signaling pathways. AEBP1 was significantly increased in leukemia cell lines, especially in Jurkat cells, compared with the Pbmc cells. Silencing AEBP1 markedly reduced proliferation and induced cell cycle arrest in Jurkat cells, but also promoted apoptosis of Jurkat cells. Silencing AEBP1 also inhibited the expression of p53 and Bcl-2 but promoted Bax in Jurkat cells.

CONCLUSIONS

AEBP1 was highly-expressed in the diagnosis and relapse cALL, and silencing AEBP1 significantly reduced proliferation but promoted apoptosis in Jurkat cells via a p53-dependent pathway.

Integrated omics analysis of sweat reveals an aberrant amino acid metabolism pathway in Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada (VKH) disease is an autoimmune disease leading to visual impairment. Its pathogenic mechanisms remain poorly understood. Our purpose was to investigate the distinctive protein and metabolic profiles of sweat in patients with VKH disease. In the present study, proteomics and metabolomics analysis was performed on 60 sweat samples (30 VKH patients and 30 normal controls) using liquid chromatography tandem mass spectrometry. Parallel reaction monitoring (PRM) analysis was used to validate the results of our omics analysis. In total, we were able to detect 716 proteins and 175 metabolites. Among them, 116 proteins (99 decreased and 17 increased) were observed to be significantly different in VKH patients when compared to controls. Twenty-one differentially expressed metabolites were identified in VKH patients, of which 18 included choline, L-tryptophan, betaine and L-serine were reduced, while the rest were increased. Our multi-omics strategy reveals an important role for the amino acid metabolic pathway in the pathogenesis of VKH disease. Significant differences in proteins and metabolites were identified in the sweat of VKH patients and, to some extent, an aberrant amino acid metabolism pathway may be a pathogenic factor in the pathogenesis of VKH disease.

[Surgical treatment of the complex bicondylar tibial plateau fracture using a midline longitudinal incision]

Objective: To explore the outcomes after treatment of the complex bicondylar tibial plateau fracture through a midline longitudinal approach. Methods: A review of fifteen patients with an average age of (51.3±12.3) years old (range17-65yers;7 males, 8 females) surgically treated from October 2013 to Febuary 2018 were included. Sahatker Ⅴ in 10, Sahatker Ⅵ in 5; fractures of medial and lateral columns in 9, fractures of three columns in 6. All the patients were adopt a midline longitudinal approach combined with the posterior approach and bone grafting were conducted. Results: All cases were followed-up for (14.4±3.8) month, with an average of 12-24 month. All patients gained bone union during 12-16 weeks after operation, with an average of (15.2±1.3) weeks. There were significant differeces in both tibial plateau angle and posterior slope angle on radiography between preoperation and postoperation (P<0.05), there were no significant differeces in either tibial plateau angle or posterior slope angle on radiography between immediate postoperation and 12 months postoperation (P>0.05). At final follow-up,both the Lachman test and the Pivot-shift test were negative. All patients had complete knee extension, knee flexion angle 100°-135°, with an average of 117.7°±11.3°. The HSS (the Hospital for Special Surgery) score were 66-98, with an average of 85.1±9.3, six cases were excellent and seven cases were good, two cases was fair, the excellent and good rate was 86.7%. The Rasmussen radiological evaluationre were 9-18, with an average of 15.1±2.5, three cases were excellent and eleven cases were good, one cases was fair, the excellent and good rate was 93.3%. 1 patient had fat liquefactionof in antero incision, and got good outcomes after debridement dressing. Conclusion: The treatment of the complex bicondylar tibial plateau fracture through a midline longitudinal approach combined with the posterior approach can result in good exposure and satisfying knee function in short-term.

Quantitative Assessment of Weight-Bearing Fracture Biomechanics Using Extremity Cone-Beam CT

PURPOSE

We investigate an application of multisource extremity Cone-Beam CT (CBCT) with capability of weight-bearing tomographic imaging to obtain quantitative measurements of load-induced deformation of metal internal fixation hardware (e.g. tibial plate). Such measurements are desirable to improve the detection of delayed fusion or non-union of fractures, potentially facilitating earlier return to weight-bearing activities.

METHODS

To measure the deformation, we perform a deformable 3D-2D registration of a prior model of the implant to its CBCT projections under load-bearing. This Known-Component Registration (KC-Reg) framework avoids potential errors that emerge when the deformation is estimated directly from 3D reconstructions with metal artifacts. The 3D-2D registration involves a free-form deformable (FFD) point cloud model of the implant and a 3D cubic B-spline representation of the deformation. Gradient correlation is used as the optimization metric for the registration. The proposed approach was tested in experimental studies on the extremity CBCT system. A custom jig was designed to apply controlled axial loads to a fracture model, emulating weight-bearing imaging scenarios. Performance evaluation involved a Sawbone tibia phantom with an ~4 mm fracture gap. The model was fixed with a locking plate and imaged under five loading conditions. To investigate performance in the presence of confounding background gradients, additional experiments were performed with a pre-deformed femoral plate placed in a water bath with Ca bone mineral density inserts. Errors were measured using eight reference BBs for the tibial plate, and surface point distances for the femoral plate, where a prior model of deformed implant was available for comparison.

RESULTS

Both in the loaded tibial plate case and for the femoral plate with confounding background gradients, the proposed KC-Reg framework estimated implant deformations with errors of <0.2 mm for the majority of the investigated deformation magnitudes (error range 0.14 - 0.25 mm). The accuracy was comparable between 3D-2D registrations performed from 12 x-ray views and registrations obtained from as few as 3 views. This was likely enabled by the unique three-source x-ray unit on the extremity CBCT scanner, which implements two off-central-plane focal spots that provided oblique views of the field-of-view to aid implant pose estimation.

CONCLUSION

Accurate measurements of fracture hardware deformations under physiological weight-bearing are feasible using an extremity CBCT scanner and FFD 3D-2D registration. The resulting deformed implant models can be incorporated into tomographic reconstructions to reduce metal artifacts and improve quantification of the mineral content of fracture callus in CBCT volumes.

Application of a Novel Ultra-High Resolution Multi-Detector CT in Quantitative Imaging of Trabecular Microstructure

PURPOSE

To evaluate the performance of a novel ultra-high resolution multi-detector CT scanner (Canon Aquilion Precision UHR CT), capable of visualizing ~150 μm details, in quantitative assessment of bone microarchitecture. Compared to conventional CT, the spatial resolution of UHR CT begins to approach the size of the trabeculae. This might enable measurements of microstructural correlates of osteoporosis, osteoarthritis, and other bone disease.

METHODS

The UHR CT system features a 160-row x-ray detector with 250×250 μm pixels (measured at isocenter) and a custom-designed x-ray source with a 0.4×0.5 mm focal spot. Visualization of high contrast details down to ~150 μm has been achieved on this device, which is now commercially available for clinical use. To evaluate the performance of UHR CT in quantification of bone microstructure, we imaged a variety of human bone samples (including ulna, radius, and vertebrae) embedded in a ~16 cm diameter plastic cylinder and in an anthropomorphic thorax phantom (QRM-Thorax, QRM Gmbh). Helical UHR CT acquisitions (120 kVp tube voltage) were acquired at scan exposures of 375 mAs - 5 mAs. For comparison, the samples were also imaged using a Normal Resolution (NR) mode available on the scanner, involving 500 μm slice thickness, exposure of 50 mAs, and a focal spot of 0.6×1.3 mm. We obtained micro-CT (μCT) of the bone samples at ~28 μm voxel size as a gold-standard reference. Geometric measurements of bone microstructure were performed in 17 regions-of-interests (ROIs) distributed throughout the bones of the phantoms; image registration was used to place the ROIs at corresponding locations in the UHR CT and NR CT. Trabecular thickness Tb.Th, spacing Tb.Sp, and Bone Volume fraction BvTv were obtained. The UHR and NR imaging protocols were compared terms of correlations to μCT and error of trabecular measurements. The effect of dose on trabecular morphometry was also studied for the UHR CT. Furthermore, we evaluated the sensitivity of texture features of trabecular bone (recently proposed as an alternative to geometric indices of microstructure) to imaging protocol. Image texture evaluation was performed using ~150 regions of interest (ROIs) across all bone samples. Three-dimensional Gray Level Co-occurrence Matrix (GLCM) and Gray Level Run Length Matrix (GLRM) features were extracted for each ROI. We analyzed correlation and concordance correlation coefficient (CCC) of the mean ROI values of texture features obtained using the UHR and NR modes.

RESULTS

UHR CT reconstructions of bone samples clearly demonstrated improved visualization of the trabeculae compared to NR CT. UHR CT achieved substantially better correlations for all three metrics of bone microstructure, in particular for BvTv (correlation coefficient of 0.91 for UHR CT compared to 0.84 for NR CT) and TbSp (correlation of 0.74 for UHR CT and 0.047 for NR CT). The error obtained with UHR CT was generally smaller than that of NR CT. For TbSp, the mean deviation from μCT (averaged across all bone samples) was only ~0.07 for UHR CT, compared to 0.25 for NR CT. Analysis of reproducibility of texture features of trabecular bone between UHR CT and NR CT revealed fair correlations (>0.7) for the majority of GLCM features, but relatively poor CCC (e.g. 0.02 for Energy and 0.04 for Entropy). The magnitude of texture metrics is particularly affected by the enhanced spatial resolution of UHR CT.

CONCLUSION

The recently introduced UHR CT achieves improved correlation and reduced error in measurements of trabecular bone microstructure compared to conventional resolution CT. Future development of diagnostic strategies based on textural biomarkers derived from UHR CT will need to account for potential sensitivity of texture features to image resolution.

Potential role and mechanism for high mobility group box1 in childhood chronic immune thrombocytopenia

OBJECTIVE

High mobility group box1(HMGB1) can be used as PAMP or alarmins to stimulate the innate immune system; however, previous research on immune thrombocytopenic purpura (ITP) mainly focused on its adaptive immunity. The study aimed to determine whether HMGB1 is associated with chronic ITP (cITP) during childhood and investigate its role in innate immunity in childhood cITP.

PATIENTS AND METHODS

We recruited 80 patients to measure the expression of HMGB1, IL-17, and IL-10; 55 patients were recruited to measure the expression of TLR2 and TLR4 in monocyte and CD1c+dendritic cells, and 30 volunteers were included as controls. We focused on the expression of the NLRP3 inflammasome during childhood cITP. Furthermore, the impact of HMGB1 on the NLRP3 inflammasome was explored.

RESULTS

The expressions of HMGB1 and IL-17 increased in children with cITP, while that of IL-10 decreased; HMGB1 was correlated with the expression of IL-17 and IL-10. The expression of TLR2 in CD14++CD16+, CD14+CD16++ monocytes increased significantly in comparison with the controls; the contrary was observed regarding TLR4. The expression of NLRP3, IL-1β, and IL-18 was significantly higher in CD14 and CD1c, respectively. As the concentration of HMGB1 increased, the expression of NLRP3, IL-1β, and IL-18 increased in different degrees.

CONCLUSIONS

HMGB1 could be used as an early warning alarm for childhood cITP and is involved in developing cITP. HMGB1 could affect the incidence and development of chronic childhood ITP via the NLRP3, TLR2/TLR4 pathways.

Quantitative Evaluation of Bone Microstructure using High-Resolution Extremity Cone-Beam CT with a CMOS Detector

Purpose

A high-resolution cone-beam CT (CBCT) system for extremity imaging has been developed using a custom complementary metal-oxide-semiconductor (CMOS) x-ray detector. The system has spatial resolution capability beyond that of recently introduced clinical orthopedic CBCT. We evaluate performance of this new scanner in quantifying trabecular microstructure in subchondral bone of the knee.

Methods

The high-resolution scanner uses the same mechanical platform as the commercially available Carestream OnSight 3D extremity CBCT, but replaces the conventional amorphous silicon flat-panel detector (a-Si:H FPD with 0.137 mm pixels and a ~0.7 mm thick scintillator) with a Dalsa Xineos3030 CMOS detector (0.1 mm pixels and a custom 0.4 mm scintillator). The CMOS system demonstrates ~40% improved spatial resolution (FWHM of a ~0.1 mm tungsten wire) and ~4× faster scan time than FPD-based extremity CBCT (FPD-CBCT). To investigate potential benefits of this enhanced spatial resolution in quantitative assessment of bone microstructure, 26 trabecular core samples were obtained from four cadaveric tibias and imaged using FPD-CBCT (75 μm voxels), CMOS-CBCT (75 μm voxels), and reference micro-CT (μCT, 15 μm voxels). CBCT bone segmentations were obtained using local Bernsen's thresholding combined with global histogram-based pre-thresholding; μCT segmentation involved Otsu's method. Measurements of trabecular thickness (Tb.Th), spacing (Tb.Sp), number (Tb.N) and bone volume (BV/TV) were performed in registered regions of interest in the segmented CBCT and μCT reconstructions.

Results

CMOS-CBCT achieved noticeably improved delineation of trabecular detail compared to FPD-CBCT. Correlations with reference μCT for metrics of bone microstructure were better for CMOS-CBCT than FPD-CBCT, in particular for Tb.Th (increase in Pearson correlation from 0.84 with FPD-CBCT to 0.96 with CMOS-CBCT) and Tb.Sp (increase from 0.80 to 0.85). This improved quantitative performance of CMOS-CBCT is accompanied by a reduction in scan time, from ~60 sec for a clinical high resolution protocol on FPD-CBCT to ~17 sec for CMOS-CBCT.

Conclusion

The CMOS-based extremity CBCT prototype achieves improved performance in quantification of bone microstructure, while retaining other diagnostic capabilities of its FPD-based precursor, including weight-bearing imaging. The new system offers a promising platform for quantitative imaging of skeletal health in osteoporosis and osteoarthritis.

[Relationship between liver controlled attenuation parameters and body fat mass and its distribution]

Objective: To explore the relationship between liver controlled attenuation parameters (CAP) and body fat mass and its distribution. Methods: From May to December 2018, 978 adult patients visited at the fatty liver center of the Third People's Hospital of Changzhou were treated. The patient's liver controlled attenuation parameters were measured by transient elastography and the body fat mass and its distribution were measured by bioelectrical impedance technology. Pearson's correlation coefficient was adopted to describe the correlation between liver CAP value and body mass index (BMI), body fat mass index (BFMI), trunk fat mass index (TFMI), limbs fat mass index (LFMI) and visceral fat area (VFA). Receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to evaluate BMI, BFMI, TFMI, LFMI and VFA to differentiate the cut-off points and efficacy of CAP for diagnosing grading of fatty liver changes in S0-1 and S2-3. Results: In 653 cases of male, S0 ~ S3 accounted for 4.90%, 3.37%, 22.36% and 69.37%, respectively, and in 325 cases of females, S0 ~ S3 accounted for 7.38%, 6.46%, 13.23% and 72.92%, respectively. Female patients had more visceral, trunk and limbs fat than male (P < 0.01). Body mass, body fat mass, body fat percentage, BMI, BFMI, TFMI, LFMI, and VFA were increased in male and female patients with increasing liver fat grade (P < 0.01). CAP values ​​of male and female patients were positively correlated with BMI, BFMI, TFMI, LFMI and VFA. Percentage of body fat mass increased with increasing liver fat grade (male: F = 13.42, P < 0.001; female: F = 3.22, P = 0.023); while limb fat mass percentage did not increase with liver fat grade (Male: F = 1.13, P = 0.34; female: F = 1.05, P = 0.37). Hepatic steatosis grading (S0 ~ 1 or S2 ~ 3) diagnosed with CAP were distinguished through BMI, BFMI, TFMI, LFMI and VFA. AUC was 0.80 ~ 0.82 in males (P < 0.01), and 0.75 ~ 0.78 in females (P < 0.01). Conclusion: The liver CAP value is positively correlated with the body's limbs, trunk and visceral fat, and has a strong correlation with trunk and visceral fat. BMI, BFMI, TFMI, LFMI and VFA up to some extent can identify the CAP diagnosis of grading of fatty liver changes in S0-1 and S2-3.

MicroRNA 34b inhibits cell proliferation in pediatric acute myeloid leukemia via regulating LDHA

OBJECTIVE

To elucidate the regulatory effect of microRNA-34b on the occurrence of pediatric acute myeloid leukemia and the underlying mechanism.

PATIENTS AND METHODS

The expression of microRNA-34b in the bone marrow of 72 children with newly diagnosed acute myeloid leukemia (AML) was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between microRNA-34b expression and pathological characteristics was analyzed. Kaplan-Meier curve was introduced for evaluating the prognostic value of microRNA-34b in pediatric AML. The regulatory effects of microRNA-34b on proliferation, cell cycle, and apoptosis of leukemia cells were accessed by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Bioinformatics prediction and dual-luciferase reporter gene assay were conducted to evaluate the binding between microRNA-34b and lactate dehydrogenase A (LDHA). LDHA expression after overexpression of microRNA-34b was determined by qRT-PCR and Western blot. Rescue experiments were conducted to verify whether microRNA-34b could regulate proliferative and apoptotic behaviors of leukemia cells by suppressing LDHA expression.

RESULTS

MicroRNA-34b was markedly downregulated in AML children. Low expression of microRNA-34b was correlated to FAB typing, cytogenetic abnormality, and day 7 response to the treatment of pediatric AML. By collecting the follow-up data, it was found that low expression of microRNA-34b was correlated to the poor prognosis of AML. Overexpression of microRNA-34b inhibited proliferative ability and cell cycle progression, but accelerated apoptosis of AML cells. Dual-luciferase reporter gene assay verified that microRNA-34b could bind to LDHA, thereafter inhibiting LDHA expression. Overexpression of LDHA reversed the regulatory effects of microRNA-34b on proliferation, cell cycle, and apoptosis of AML cells.

CONCLUSIONS

We found that microRNA-34b is lowly expressed in pediatric AML patients, and low expression of microRNA-34b may serve as an indicator of malignant progression and poor prognosis of pediatric AML. MicroRNA-34b may affect the proliferation and apoptosis of leukemia cells by regulating the expression of LDHA.