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.

[Comparison of flow conditions of adhesives and retention force of restorations among four cement-retained methods of implant-supported fixed prostheses]

Objective: To compare the effect on the flow conditions of adhesives and the retention force of restorations among different cement-retained methods of implant-supported fixed prostheses. Methods: Four common cement-retained methods were selected, including the occlusal hole for screw access (OH), the lingual hole for adhesives overflow (LH), the resin replica for titanium abutment (RR), and the traditional cement-retained method (the control group). The adhesive used in this study was resin-modified glass ionomer cement. The two-dimensional analysis models of computational fluid dynamics (CFD) were established. The flow conditions of adhesives in the adhesion process was analyzed by the CFD analysis. The internal filling ratio and the amount of neck overflow of adhesives below the edge of the prosthesis were calculated. Ten zirconia prostheses in each group were processed and cemented. The retention force was examined by mechanical tensile experiments in vitro. Results: The CFD analysis showed the internal filling ratio of adhesives from high to low was the LH group, the OH group, the RR group and the control group. The amount of neck overflow of adhesives below the edge of the prosthesis from less to more was the RR group, the OH group, the LH group and the control group. The retention force was (240.7±33.9) N in the control group, (278.2±59.1) N in the OH group, (292.9±47.9) N in the LH group, and (262.8±59.4) N in the RR group. There was a statistically significant difference in the retention force between the LH group and the control group (P=0.029). There was no significant difference among the other groups (P>0.05). Conclusions: The modified cement-retained methods can effectively reduce the amount of neck overflow of adhesives, and improve the filling condition of adhesive in the adhesive clearance to ensure the retention force of the prostheses. Clinically, the appropriate modified cement-retained method should be selected according to the three-dimensional position of the implant and the position of prosthetic margin.

Known-Component Model-Based Material Decomposition for Dual Energy Imaging of Bone Compositions in the Presence of Metal Implant

Dual energy computed tomography (DE CT) is a promising technology for the assessment of bone compositions. One of potential applications involves evaluations of fracture healing using longitudinal measurements of callus mineralization. However, imaging of fractures is often challenged by the presence of metal fixation hardware. In this work, we report on a new simultaneous DE reconstruction-decomposition algorithm that integrates the previously introduced Model-Based Material Decomposition (MBMD) with a Known-Component (KC) framework to mitigate metal artifacts. The algorithm was applied to the DE data obtained on a dedicated extremity cone-beam CT (CBCT) with capability for weight-bearing imaging. To acquire DE projections in a single gantry rotation, we exploited a unique multisource design of the system, where three X-ray sources were mounted parallel to the axis of rotation. The central source provided high energy (HE) data at 120 kVp, while the two remaining sources were operated at a low energy (LE) of 60 kVp. This novel acquisition trajectory further motivates the use of MBMD to accommodate this complex DE sampling pattern. The algorithm was validated in a simulation study using a digital extremity phantom. The phantom consisted of a water background with an insert containing varying concentrations of calcium (50 - 175 mg/mL). Two configurations of titanium implants were considered: a fixation plate and an intramedullary nail. The accuracy of calcium-water decompositions obtained with the proposed KC-MBMD algorithm was compared to MBMD without metal component model. Metal artifacts were almost completely removed by KC-MBMD. Relative absolute errors of calcium concentration in the vicinity of metal were 6% - 31% for KC-MBMD (depending on the calcium insert and implant configuration), compared favorably to 48% - 273% for MBMD. Moreover, accuracy of concentration estimates for KC-MBMD in the presence of metal implant approached that of MBMD in a configuration without implant (6%-23%). The proposed algorithm achieved accurate DE material decomposition in the presence of metal implants using a non-conventional, axial multisource DE acquisition pattern.

[A multicentric clinical study on clinical characteristics and drug sensitivity of children with pneumococcal meningitis in China]

Objective: To understand clinical characteristics of children with pneumococcal meningitis (PM) in China and to analyze the drug sensitivity of Streptococcus pneumoniae isolates and associated impacts on death and sequelae. Methods: The clinical data, follow-up results and antimicrobial sensitivity of isolated strains of 155 children (including 98 males and 57 females, age ranged from 2 months to 15 years) with PM in 10 tertiary-grade A class hospitals of Infectious Diseases Surveillance of Pediatrics (ISPED) from 2013 to 2017 were collected and analyzed retrospectively. Patients were divided into different groups according to the following standards: ≤1 year old group,>1-3 years old group and >3 years old group according to age; death group and non-death group according to the death within 30 days after PM diagnosis; complication group and non-complication group according to the abnormal cranial imaging diagnosis; sequelae group and no-sequelae group according to the follow-up results. Bonfereoni chi-square segmentation and Kruskal-Wallis H test were used for statistical analysis. Results: There were 64 cases (41.3%) in the ≤1 year old group, 39 cases in the >1-3 years old group (25.2%), and 52 cases (33.5%) in the >3 years old group. The most common clinical manifestation was fever (151 cases, 97.4%). The mortality was 16.8% (26/155) during hospitalization. The neurological complication rate was 49.7% (77/155) during hospitalization, including the most common complication, subdural effusion and (or) empyema in 50 cases (32.3%) and hearing impairment in 6 cases. During follow-up after discharge, no death was found and focal neurological deficits were found in 47 cases (30.3%), including the frequent neurological sequelae: cognitive and mental retardation of different degree in 22 cases and hearing impairment in 14 cases (9.0%). The rate of cure and improvement on discharge was 74.8% (116/155) and the lost to follow-up rate was 8.4% (13/155). The proportions of died cases, neurological complications during hospitalization and proportions of peripheral white blood cell count <12 × 10(9)/L before admission in ≤1 year old group were significantly higher than those in >3 years old group (25.0% (16/64) vs. 5.8% (3/52), 75.0% (48/64) vs. 25.0% (13/52), 48.4% (31/64) vs. 15.4% (8/52), χ(2)=7.747, 28.767, 14.044; P=0.005, 0.000, 0.000). The proportions of headache, vomiting, neck resistance and high risk factors of purulent meningitis in >3 years old group were significantly higher than those in ≤ 1 year old group (67.3%(35/52) vs. 1.6%(1/64), 80.8% (42/52) vs. 48.4% (31/64), 69.2% (36/52) vs. 37.5% (24/64), 55.8% (29/52) vs. 14.1%(9/64), χ(2)=57.940, 12.856, 11.568, 22.656; P=0.000, 0.000, 0.001, 0.000). Streptococcus pneumoniae isolates were completely sensitive to vancomycin (100.0%, 152/152), linezolid (100.0%, 126/126), moxifloxacin (100.0%, 93/93) and ofloxacin (100.0%,41/41); highly sensitive to levofloxacin (99.3%, 142/143) and ertapenem (84.6%, 66/78); moderately sensitive to ceftriaxone (48.4%, 45/93), cefotaxime (40.0%, 44/110) and meropenem (38.0%, 38/100); less sensitive to penicillin (19.6%, 27/138) and erythromycin (4.2%, 5/120). The proportions of non-sensitive strains of penicillin (21/21) and meropenem (17/18) in the death group were significantly higher than those (90/117, 45/82) in the survived group(χ(2)=4.648 and 9.808, P=0.031 and 0.002). Conclusions: The children's PM is mainly found in infants under 3 years old in China. Death and neurological complications are more common in PM children under 1 year old. The clinical manifestations and peripheral blood inflammatory markers of PM patients under 1 year old are not typical. Fever is the most common clinical manifestation and subdural effusion and (or) empyema is the most common complication. Long-term hearing impairment is common in PM and the follow-up time must be prolonged. The dead PM cases had high in sensitive rates to penicillin and meropenem.

Identification of susceptibility SNPs in CTLA-4 and PTPN22 for scleritis in Han Chinese

The aim of this study was to determine the association between 13 single nucleotide polymorphisms (SNPs) in the cytotoxic T lymphocyte-associated antigen-4 (CTLA4) and protein tyrosine phosphatase non-receptor type 22 (PTPN22) genes with scleritis in a Chinese Han population. We recruited 432 scleritis patients and 710 healthy controls. Four tag SNPs of CTLA4 and nine tag SNPs of PTPN22 were selected using Haploview. Genotyping was performed with the Sequenom MassArray® iPLEX GOLD Assay. Genotype and allele frequency differences were analyzed by χ² test and Bonferroni correction. Haplotype analysis was performed to further evaluate the association of these two genes with scleritis. In this study, CTLA4/rs3087243 G allele frequency and GG genotype frequency were significantly increased in scleritis patients compared to healthy controls [corrected P-value (Pc) = 0·02, odds ratio (OR) = 1·475, 95% confidence interval (CI) = 1·175-1·851; Pc = 0·04, OR = 1·546, 95% CI = 1·190-2·008, respectively]. None of the tested SNPs in the PTPN22 gene showed an association with scleritis. Haplotype analysis revealed a lower frequency of a CTLA4 TCAA haplotype (order of SNPs: rs733618, rs5742909, rs231775, rs3087243) (Pc = 4·26 × 10^-3 , OR = 0·618, 95% CI = 0·540-0·858) and a higher frequency of a PTPN22 TTATACGCG haplotype (order of SNPs: rs3789604, rs150426536, rs1746853, rs1217403, rs1217406, rs3789609, rs1217414, rs3789612, rs2488457) (Pc = 2·83 × 10^-4 , OR = 1·457, 95% CI = 1·210-1·754) in scleritis patients when compared to healthy controls. In conclusion, our findings indicate that CTLA4 and PTPN22 might confer genetic susceptibility to scleritis in a Chinese Han population.

Quantitative Cone-Beam CT of Bone Mineral Density Using Model-Based Reconstruction

PURPOSE

We develop and validate a model-based framework for artifact correction and image reconstruction to enable application of Cone-Beam CT (CBCT) in quantitative assessment of bone mineral density (BMD). Compared to conventional quantitative CT, this approach does not require a BMD calibration phantom in the field-of-view during an object scan.

METHODS

The quantitative CBCT (qCBCT) imaging framework combined fast Monte Carlo (MC) scatter estimation, accurate models of detector response, and polyenergetic Poisson likelihood (PolyPL, Elbakri et al 2003). The underlying object model assumed that the tissues were ideal mixtures of water and calcium carbonate (CaCO₃). Accuracy and reproducibility of qCBCT was evaluated in benchtop test-retest studies emulating a compact extremity CBCT system (axis-detector distance=56 cm, 90 kVp x-ray beam, ~16 mGy central dose). Various arrangements of Ca inserts (50-500 mg/mL) were placed in water cylinders of ~11 cm to ~15 cm diameter and scanned at multiple positions inside the field-of-view for a total of 20 configurations. In addition, a cadaveric ankle was imaged in five configurations (with and without Ca inserts and water bath). Coefficient of variation (CV) of BMD values across different experimental configurations was used to assess reproducibility under varying imaging conditions. The performance of the model-based qCBCT framework (MC + PolyPL) was compared to FDK with water beam hardening correction and MC scatter correction.

RESULTS

The PolyPL framework achieved accuracy of 20 mg/mL or better across all insert densities and experimental configurations. By comparison, the accuracy of the FDK-based BMD estimates deteriorated with higher mineralization, resulting in ~120 mg/mL error for a 500 mg/mL Ca insert. Additionally, the model-based approach mitigated residual streaks that were present in FDK reconstructions. The CV of both methods was ~15% at 50 mg/mL Ca and less than ~8% for higher density inserts, where the PolyPL framework achieved 20-25% lower CV than the FDK-based approach.

CONCLUSION

Accurate and reproducible BMD measurements can be achieved in extremity CBCT, supporting clinical applications in quantitative monitoring of fracture risk, osteoporosis treatment, and early osteoarthritis.

Cost-Effectiveness of Scaling Up Modern Family Planning Interventions in Low- and Middle-Income Countries: An Economic Modeling Analysis in Indonesia and Uganda

OBJECTIVES

The aim was to estimate the long-term cost-effectiveness of improved family planning interventions to reduce the unmet need in low- and middle-income countries, with Indonesia and Uganda as reference cases.

METHODS

The analysis was performed using a Markov decision analytic model, where current situation and several scenarios to reduce the unmet need were incorporated as the comparative strategies. Country-specific evidence was synthesized from the demographic and health survey and published studies. The model simulated the sexual and reproductive health experience of women in the reproductive age range over a time horizon of women's reproductive years, from the healthcare payer perspective. Modeled outcomes included clinical events, costs and incremental cost-effectiveness ratios (ICERs) expressed as cost per disability-adjusted life year (DALY) averted. Deterministic and probabilistic sensitivity analyses were conducted to assess the impact of parameter uncertainty on modeled outcomes.

RESULTS

In the hypothetical cohort of 100,000 women, scenarios to reduce the unmet need for family planning would result in savings within a range of US$230,600-US$895,100 and US$564,400-US$1,865,900 in Indonesia and Uganda, respectively. The interventions would avert an estimated 1859-3780 and 3705-12,230 DALYs in Indonesia and Uganda, respectively. The results of our analysis indicate that scaling up family planning dominates the current situation in all scenarios in both countries, with lower costs and fewer DALYs. These results were robust in sensitivity analyses.

CONCLUSION

Scaling up family planning interventions could improve women's health outcomes substantially and be cost-effective or even cost saving across a range of scenarios compared to the current situation.

MiR-410 regulates malignant biological behavior of pediatric acute lymphoblastic leukemia through targeting FKBP5 and Akt signaling pathway

OBJECTIVE

The aim of this study was to investigate the role of miR-410 in regulating the proliferation and apoptosis of pediatric acute lymphoblastic leukemia (ALL) cells and to explore the possible underlying mechanism.

PATIENTS AND METHODS

The expression level of miR-410 in ALL cases and cells was detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR). Luciferase reporter gene assay was performed to evaluate the interaction between miR-410 and FKBP5. MTT and colony formation assay were used to determine the effect of miR-410 on the proliferation and colony formation ability of ALL cells. The effect of miR-410 on cell apoptosis was measured by Annexin V-fluorescein isothiocyanate 1 (FITC) and propidium iodide (PI). Western blot was used to analyze the effect of miR-410 on the protein expression levels of phosphorylated Akt (p-Akt) and cleaved caspase-3.

RESULTS

In our investigation, miR-410 was significantly up-regulated in ALL cases and cells. We searched three public databases to predict the potential target of miR-410, and found that FKBP5 was a direct target of miR-410. Meanwhile, Luciferase reporter gene assay confirmed our hypothesis. The overexpression of miR-410 accelerated the proliferation and colony formation ability of ALL cells, whereas remarkably decreased cell apoptosis rate. Western blotting showed that miR-410 inhibited the activation of Akt signaling pathway. However, FKBP5 could reverse the effects of miR-410.

CONCLUSIONS

MiR-410 regulated the proliferation, colony formation and apoptosis of ALL cells through targeting FKBP5 and Akt signal pathway, indicating that miR-410 might be a potential therapeutic target for the treatment of ALL.

[Clinical characteristics and antimicrobial resistance of pneumococcal infections from 9 children's hospitals in 2016]

Objective: To describe the clinical characteristics of pneumococcal infections and drug resistance of Streptococcus pneumoniae isolates from children's hospitals, which would provide reference for preventing and treating pneumococcal diseases. Methods: This was a prevalence survey. In this study, the age, specimen type, monthly distribution characteristics, and antimicrobial resistance of Streptococcus pneumoniae isolates from 9 children's hospitals in China were investigated between January 1, 2016 and December 31, 2016. The WHONET 5.6 software was used to analyze the antibiotic susceptibility of Streptococcus pneumoniae. The comparison of rates was performed by Chi-square test. Results: A total of 6 200 isolates of streptococcus pneumoniae were obtained, namely, 95.1% (5 876/6 177) from the respiratory tract specimens, 2.2% (136/6 177) from blood specimens and 0.4% (24/6 177) from cerebrospinal fluid specimens. The isolates were mainly from children older than 1 and younger than 5 years (54.7%, 3 381/6 185) . Most of strains (33.2%, 1 184/3 563) were isolated in November, December and January. Streptococcus pneumoniae isolates were completely sensitive to vancomycin (100.0%, 6 189/6 189) , linezolid (100.0%, 6 030/6 030) , moxifloxacin (100.0%, 3 064/3 064) , highly sensitive to levofloxacin (99.8%, 5 528/5 540), ertapenem (98.8%, 3 024/3 061) and lowly sensitive to erythromycin (1.7%, 102/6 016), clindamycin (3.7%, 116/3 136), and tetracycline (5%, 244/4 877), respectively. According to the parenteral susceptibility breakpoints for non-meningitis isolates, the sensitivity of Streptocococus pneumoniae to penicillin from children's hospital of Chongqing Medical University (49.3%, 892/1 809) was significantly lower than those of other hospitals (χ(2)=1 268.161, P<0.05) . Conclusions:Streptococcus pneumoniae is mainly isolated from respiratory tract, from children older than 1 and younger than 5 years and during November to January in tertiary children's hospital of China. The Streptococcus pneumoniae from children is highly sensitive to vancomycin, linezolid, moxifloxacin, levofloxacin. There are also significant differences in the sensitivity of penicillin for Streptococcus pneumoniae from different hospitals.

Experimental investigation on the distribution of spray water in a spent fuel-assembly simulator

The spent fuel pool cooling system in a nuclear power plant, which is comprised mainly by the cooling pumps and heat exchangers, ensures the safety of the spent fuel assemblies and the integrity of the fuel rods during the period of storage. With the development of the passive cooling technique, a spray cooling system for the spent fuels based on the gravity was designed to further enhance the safety of the spent fuel pool in case of accident conditions. This paper presents an experimental investigation of the validity of the spray-cooling system using two types of tight rod bundles, namely a 5 × 5 heated rod bundle and a 17 × 17 isothermal rod bundle. Results shows that the rod bundle heated with a lower power can be effectively cooled only by air without any spray water. With the increase of the heated power, the rod surface temperature increases gradually and the spray cooling has to be implemented to maintain the wall temperature at a certain level. The effect of flow rate on wall temperature was investigated. For the isothermal rod bundle, main interests were focused on the distribution of the spray water after it flowed along the rods.

Research on thermal-hydraulic behavior in the spent fuel pool using a full-height experimental facility

During accident scenarios the effective cooling of spent fuel directly affects the safety of nuclear power plants. Two experiments were performed in a full-height facility to study the thermal-hydraulic behavior in spent fuel pool. In spent fuel pool boiling experiment, the heat transfer characteristics are related to the flow patterns. However, the flow pattern in narrow and long channel is different from the traditional flow pattern. In the semi-dry of heated rod, wall temperature oscillation occurs for a long time. In the spent fuel pray experiment, the liquid film thickness varies randomly with time and space. As the spray flow density increase, the maximum wall temperature decrease gradually with a certain linear characteristic.

A new locus regulating MICALL2 expression was identified for association with executive inhibition in children with attention deficit hyperactivity disorder

Impaired executive inhibition is a core deficit of attention deficit hyperactivity disorder (ADHD), which is a common childhood-onset psychiatric disorder with high heritability. In this study, we performed a two-stage genome-wide association study of executive inhibition in ADHD in Han Chinese. We used the Stroop color-word interference test to evaluate executive inhibition. After quality control, 780 samples with phenotype and covariate data were included in the discovery stage, whereas 922 samples were included in the replication stage. We identified one new significant locus at 7p22.3 for the Stroop word interference time (rs11514810, P=3.42E-09 for discovery, P=0.01176 for replication and combined P=5.249E-09). Regulatory feature analysis and expression quantitative trait loci (eQTL) data showed that this locus contributes to MICALL2 expression in the human brain. Most genes in the network interacting with MICALL2 were associated with psychiatric disorders. Furthermore, hyperactive-impulsive-like behavior was induced by reducing the expression of the zebrafish gene that is homologous to MICALL2, which could be rescued by tomoxetine (atomoxetine), a clinical medication for ADHD. Our results suggested that MICALL2 is a new susceptibility gene for executive inhibition deficiency related to hyperactive-impulsive behavior in ADHD, further emphasizing the possible role of neurodevelopmental genes in the pathogenic mechanism of ADHD.

ERAP1/ERAP2 and RUNX3 polymorphisms are not associated with ankylosing spondylitis susceptibility in Chinese Han

Previous studies show that endoplasmic reticulum‐associated aminopeptidase (ERAP1/ERAP2) and runt‐related transcription factor 3 (RUNX3) gene polymorphisms are associated with AS (ankylosing spondylitis) in European Caucasians. However, contradictory results were reported in different Asian populations. The purpose of this study was to determine whether eleven candidate single nucleotide polymorphisms (SNPs) in ERAP1/ERAP2 and six in RUNX3 genes confer susceptibility to AS with or without acute anterior uveitis (AAU) [AS⁺AAU⁺ or AS⁺AAU^–] in Chinese Han. Therefore, a case–control association study was performed in 882 AS⁺AAU^–, 884 AS⁺AAU⁺ and 1727 healthy controls. Genotyping was performed using the iPLEXGold genotyping assay. A meta‐analysis was performed to assess the association of polymorphisms of ERAP1 with AS susceptibility in Asian populations. No association was found between SNPs of ERAP1/ERAP2/RUNX3 and susceptibility of AS with or without AAU. A case–control study between patients with human leucocyte antigen HLA‐B27‐positive and healthy controls also failed to demonstrate an association of the tested SNP with AS with or without AAU. Moreover, a meta‐analysis showed that there was no association of rs30187, rs27037, rs27980, rs27434 and rs27582 in ERAP1 with AS in Chinese Han. Taken together, 17 SNPs in ERAP1/ERAP2 and RUNX3 genes did not confer disease susceptibility to AS in Chinese Han.

High-Resolution Extremity Cone-Beam CT with a CMOS Detector: Evaluation of a Clinical Prototype in Quantitative Assessment of Bone Microarchitecture

PURPOSE

A prototype high-resolution extremity cone-beam CT (CBCT) system based on a CMOS detector was developed to support quantitative in vivo assessment of bone microarchitecture. We compare the performance of CMOS CBCT to an amorphous silicon (a-Si:H) FPD extremity CBCT in imaging of trabecular bone.

METHODS

The prototype CMOS-based CBCT involves a DALSA Xineos3030 detector (99 μm pixels) with 400 μm-thick CsI scintillator and a compact 0.3 FS rotating anode x-ray source. We compare the performance of CMOS CBCT to an a-Si:H FPD scanner built on a similar gantry, but using a Varian PaxScan2530 detector with 0.137 mm pixels and a 0.5 FS stationary anode x-ray source. Experimental studies include measurements of Modulation Transfer Function (MTF) for the detectors and in 3D image reconstructions. Image quality in clinical scenarios is evaluated in scans of a cadaver ankle. Metrics of trabecular microarchitecture (BV/TV, Bone Volume/Total Volume, TbSp, Trabecular Spacing, and TbTh, trabecular thickness) are obtained in a human ulna using CMOS CBCT and a-Si:H FPD CBCT and compared to gold standard μCT.

RESULTS

The CMOS detector achieves ~40% increase in the f20 value (frequency at which MTF reduces to 0.20) compared to the a-Si:H FPD. In the reconstruction domain, the FWHM of a 127 μm tungsten wire is also improved by ~40%. Reconstructions of a cadaveric ankle reveal enhanced modulation of trabecular structures with the CMOS detector and soft-tissue visibility that is similar to that of the a-Si:H FPD system. Correlations of the metrics of bone microarchitecture with gold-standard μCT are improved with CMOS CBCT: from 0.93 to 0.98 for BV/TV, from 0.49 to 0.74 for TbTh, and from 0.9 to 0.96 for TbSp.

CONCLUSION

Adoption of a CMOS detector in extremity CBCT improved spatial resolution and enhanced performance in metrics of bone microarchitecture compared to a conventional a-Si:H FPD. The results support development of clinical applications of CMOS CBCT in quantitative imaging of bone health.

Robust Quantitative Assessment of Trabecular Microarchitecture in Extremity Cone-Beam CT Using Optimized Segmentation Algorithms

Purpose

In-vivo evaluation of bone microarchitecture remains challenging because of limited resolution of conventional orthopaedic imaging modalities. We investigate the performance of flat-panel detector extremity Cone-Beam CT (CBCT) in quantitative analysis of trabecular bone. To enable accurate morphometry of fine trabecular bone architecture, advanced CBCT pre-processing and segmentation algorithms are developed.

Methods

The study involved 35 transilliac bone biopsy samples imaged on extremity CBCT (voxel size 75 μm, imaging dose ~13 mGy) and gold standard μCT (voxel size 7.67 μm). CBCT image segmentation was performed using (i) global Otsu's thresholding, (ii) Bernsen's local thresholding, (iii) Bernsen's local thresholding with additional histogram-based global pre-thresholding, and (iv) the same as (iii) but combined with contrast enhancement using a Laplacian Pyramid. Correlations between extremity CBCT with the different segmentation algorithms and gold standard μCT were investigated for measurements of Bone Volume over Total Volume (BV/TV), Trabecular Thickness (Tb.Th), Trabecular Spacing (Tb.Sp), and Trabecular Number (Tb.N).

Results

The combination of local thresholding with global pre-thresholding and Laplacian contrast enhancement outperformed other CBCT segmentation methods. Using this optimal segmentation scheme, strong correlation between extremity CBCT and μCT was achieved, with Pearson coefficients of 0.93 for BV/TV, 0.89 for Tb.Th, 0.91 for Tb.Sp, and 0.88 for Tb.N (all results statistically significant). Compared to a simple global CBCT segmentation using Otsu's algorithm, the advanced segmentation method achieved ~20% improvement in the correlation coefficient for Tb.Th and ~50% improvement for Tb.Sp.

Conclusions

Extremity CBCT combined with advanced image pre-processing and segmentation achieves high correlation with gold standard μCT in measurements of trabecular microstructure. This motivates ongoing development of clinical applications of extremity CBCT in in-vivo evaluation of bone health e.g. in early osteoarthritis and osteoporosis.

Predictors for total hospital and cardiology cost claims among patients with atrial fibrillation initiating dabigatran or acenocoumarol in The Netherlands

AIMS

The prevalence of atrial fibrillation (AF) has increased over the past years due to aging of the population, and healthcare costs associated with AF reflect a significant financial burden. The aim of this study was to explore predictors for the real-world AF-related in-hospital costs in patients that recently initiated anticoagulation with acenocoumarol or dabigatran.

METHODS

Predictors for claimed total hospital care costs and cardiology costs in AF patients were explored by using hospital financial claims data from propensity score matched patient groups in a large Dutch community hospital. This study analyzed the total dataset (n = 766) and carried out a secondary analysis for all matched pairs of anticoagulation naïve AF patients (n = 590) by ordinal regression.

RESULTS

Dabigatran was a predictor for significantly lower cardiology and total hospital care costs (Odds Ratio [OR] = 0.43, 95% confidence interval (CI) = 0.33-0.57; and OR = 0.60, 95% CI = 0.46-0.79, respectively). Female gender was a predictor for lower total hospital care costs. Predictors for an increase in total hospital care costs were the occurrence of stroke or systemic embolism, major bleeding, and minor bleeding. The costs predictors were comparable when limiting the analysis to patients that were anticoagulation naïve. Age and CHA₂DS₂-VASc were not predictors for either cardiology or total hospital care costs in both analyses.

CONCLUSION

Dabigatran treatment was as a predictor for lower cardiology costs and lower total hospital care costs in AF patients that initiated oral anticoagulation.

[Coenzyme Q(10) treatment for one child with COQ6 gene mutation induced nephrotic syndrome and literature review]

Objective: To summarize the clinical manifestation and molecular characteristics of COQ6 mutation induced nephrotic syndrome, and to evaluate efficacy of CoQ(10) therapy. Method: Clinical data of the case with infantile nephrotic syndrome was summarized, including clinical manifestations, laboratory findings and family investigation. The patient received CoQ(10) 30 mg/(kg·d) therapy. Urine protein/creatinine ratio, serum albumin and creatinine were detected to assess the efficacy of the therapy. Result: (1) The 10 months old boy was presented with nephrotic level proteinuria and hypoalbuminemia. Extra-renal manifestations included cardiovascular abnormality, motor and mental retardation and unilateral ptosis. The patient had no consanguinity. A novel homozygous p. R360W mutation in COQ6 gene was identified and confirmed by next-generation sequencing and Sanger sequencing, respectively. Family analysis showed that homozygous p. R360W mutation in COQ6 gene was inherited from his parents. Missense p. R360W mutation was damaging by prediction online PolyPhen and SIFT software. After 2 months of CoQ(10) complementary therapy, the patient's urine protein/creatinine ratio declined from 7.2 to 1.3, and decreased further to 0.01 mg/mg with normal albumin level and renal function within 3 months. Nephropathy remission was maintained and growth retardation improved significantly during the last follow-up. Nevertheless, the patient manifested with sensorineural deafness at the age of 2 years. (2) There were 6 different mutations in coenzyme Q(10) biosynthesis monooxygenase 6 (COQ6) in 13 individuals from 7 families by homozygosity mapping in the whole world. Each mutation was linked to early-onset SRNS with sensorineural deafness. Renal biopsy revealed FSGS in 7 cases and DMS in 1 case. Other manifestations included ataxia, seizures, facial dysmorphism, nephrolithiasis and growth retardation. Four patients received CoQ(10) supplementation and responded to the treatment. Conclusion: Renal disease caused by recessive COQ6 gene mutation was nephrotic syndrome. The patient benefited from early CoQ(10) complement and reached nephropathy remission.

Upper GI GVHD: similar outcomes to other grade II graft-versus-host disease

The significance of upper gastrointestinal tract (UGI) acute GVHD (aGVHD) compared with other grade II aGVHD is not clearly defined. We compared the outcomes of patients with grade II aGVHD with or without biopsy-proven UGI involvement in three groups: grade II aGVHD without UGI (n=178), grade II aGVHD with UGI and other sites (n=102) and isolated UGI aGVHD (n=32). The overall response (ORR) to steroids at day 28 differed among the three groups (76, 67 and 91%, respectively, P=0.01), but was only marginally different in direct comparison with those without or with UGI aGVHD (P=0.07) or with isolated UGI aGVHD (P=0.06). In multivariate analysis, as compared with grade II aGVHD patients without UGI involvement, those with UGI involvement and those with isolated UGI aGVHD had similar risks of chronic GVHD, relapse and non-relapse mortality and similar disease-free survival and overall survival. Our data suggest that patients with UGI aGVHD have similar outcomes as those without UGI involvement, supporting the view that UGI aGVHD should still be included as a grade II-defining event.

Influence of moisturizer and relative humidity on human emissions of fluorescent biological aerosol particles

Utilizing the ultraviolet light-induced fluorescence (UV-LIF) measurement technique as embodied in the Waveband Integrated Bioaerosol Sensor (WIBS-4A), we evaluated the fluorescent particle emissions associated with human shedding while walking in a chamber. The mean emission rates of supermicron (1-10 μm) fluorescent particles were in the range 6.8-7.5 million particles per person-h (~0.3 mg per person-h) across three participants, for conditions when the relative humidity was 60%-70% and no moisturizer was applied after showering. The fluorescent particles displayed a lognormal distribution with the geometric mean diameter in the range 2.5-4 μm and exhibited asymmetry factors that increased with particle size. Use of moisturizer was associated with changes in number and mass emission rates, size distribution, and particle shape. Emission rates were lower when the relative humidity was reduced, but these differences were not statistically significant.

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2-interacting mediator knock-out mice

Regulatory T cells (Tregs ) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of Tregs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of Tregs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of Tregs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2-interacting mediator (Bim) knock-out mice by transient depleting Tregs . Bim is a pro-apoptotic member of the B cell lymphoma 2 (Bcl-2) family. Bim knock-out (Bim-/- ) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that Treg depletion in Bim-/- mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild-type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17α, interferon (IFN)-γ and tumour necrosis factor (TNF)-α were increased significantly after Treg depletion in Bim-/- mice. This study demonstrates that transient depletion of Tregs leads to enhanced self-reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim-deficient mice.

Generation of Mesenchymal-Like Stem Cells From Urine in Pediatric Patients

OBJECTIVES

Mesenchymal stem cells (MSCs) have been widely used for regenerative medicine. Traditionally, the procedures of MSC isolation are usually invasive and time-consuming. Urine is merely a body waste, and recent studies have suggested that urine represents an alternative source of stem cells. We, therefore, determined whether the possibility of isolating mesenchymal-like stem cells was practical from human urine.

METHODS

A total of 16 urine samples were collected from pediatric patients. Urine-derived cells were isolated, expanded, and identified for specific cell surface markers using flow cytometry. Cell morphology was observed by microscopy. Osteogenic and adipogenic differentiation potential were determinded by culturing cells in specific induction medium, and assessed by alkaline phosphatase and oil red O stainings, respectively.

RESULTS

Clones were established and passaged successfully from primary cultures of urine cells. Cultured urine-derived cells at passage 3 were fusiform and arranged with certain directionality. Urine-derived cells at passage 5 displayed expressions of cell surface markers (CD29, CD105, CD166, CD90, and CD13). There was no expression of the general hematopoietic cell markers (CD45, CD34, and HLA-DR). Under in vitro induction conditions, urine-derived cells at passage 5 were able to differentiate into osteoblasts, but not adipocytes.

CONCLUSIONS

Urine may be a noninvasive source for mesenchymal-like stem cells. These cells could potentially provide a new source of autologous stem cells for regenerative medicine and cell therapy.

High-resolution extremity cone-beam CT with a CMOS detector: Task-based optimization of scintillator thickness

PURPOSE

CMOS x-ray detectors offer small pixel sizes and low electronic noise that may support the development of novel high-resolution imaging applications of cone-beam CT (CBCT). We investigate the effects of CsI scintillator thickness on the performance of CMOS detectors in high resolution imaging tasks, in particular in quantitative imaging of bone microstructure in extremity CBCT.

METHODS

A scintillator thickness-dependent cascaded systems model of CMOS x-ray detectors was developed. Detectability in low-, high- and ultra-high resolution imaging tasks (Gaussian with FWHM of ~250 μm, ~80 μm and ~40 μm, respectively) was studied as a function of scintillator thickness using the theoretical model. Experimental studies were performed on a CBCT test bench equipped with DALSA Xineos3030 CMOS detectors (99 μm pixels) with CsI scintillator thicknesses of 400 μm and 700 μm, and a 0.3 FS compact rotating anode x-ray source. The evaluation involved a radiographic resolution gauge (0.6-5.0 lp/mm), a 127 μm tungsten wire for assessment of 3D resolution, a contrast phantom with tissue-mimicking inserts, and an excised fragment of human tibia for visual assessment of fine trabecular detail.

RESULTS

Experimental studies show ~35% improvement in the frequency of 50% MTF modulation when using the 400 μm scintillator compared to the standard nominal CsI thickness of 700 μm. Even though the high-frequency DQE of the two detectors is comparable, theoretical studies show a 14% to 28% increase in detectability index (d'²) of high- and ultrahigh resolution tasks, respectively, for the detector with 400 μm CsI compared to 700 μm CsI. Experiments confirm the theoretical findings, showing improvements with the adoption of 400 μm panel in the visibility of the radiographic pattern (2× improvement in peak-to-through distance at 4.6 lp/mm) and a 12.5% decrease in the FWHM of the tungsten wire. Reconstructions of the tibial plateau reveal enhanced visibility of trabecular structures with the CMOS detector with 400 μm scinitllator.

CONCLUSION

Applications on CMOS detectors in high resolution CBCT imaging of trabecular bone will benefit from using a thinner scintillator than the current standard in general radiography. The results support the translation of the CMOS sensor with 400 μm CsI onto the clinical prototype of CMOS-based extremity CBCT.

Polymorphisms in Toll-like receptor 3 are associated with asthma-related phenotypes in the Chinese Han patients

Toll-like receptor (TLR) 3 mediates antivirus immunity and is involved in asthma exacerbation and development. However, the genetic association between TLR3 and asthma remains unclear. This study aimed to evaluate the effects of polymorphisms within TLR3 on asthma risk and asthma-related phenotypes in the Chinese Han population. A total number of 462 unrelated adult patients with asthma and 398 healthy volunteers were enrolled in this study. The genotypes of tagging single nucleotide polymorphisms (SNPs) in TLR3 gene were determined using multiplex SNaPshot SNP genotyping assays. Case-control and case-only studies were used to assess any links with asthma and asthma-related phenotypes. The results showed that the genetic variants in TLR3 were associated with asthma-related phenotypes, including eosinophil counts, serum immunoglobulin E levels and lung function. However, there was no obvious association between the TLR3 SNPs and asthma susceptibility or asthma severity. TLR3 polymorphisms may play a considerable role in the pathogenesis of asthma. It will help in better understanding the pathogenesis of asthma and development of more effective strategies for the prevention, prediction and treatment of asthma.

A spray cooling technique for spent fuel assembly stored in pool

For the safety of spent nuclear fuel assemblies stored in storage pool in the extreme condition where the water is lost completely, a passive spray cooling technique was designed, and its effectiveness has been validated by a functional experiment. The spray cooling characteristics of the spent fuel assembly have also been investigated by the experiment.

Image-Based Motion Compensation for High-Resolution Extremities Cone-Beam CT

PURPOSE

Cone-beam CT (CBCT) of the extremities provides high spatial resolution, but its quantitative accuracy may be challenged by involuntary sub-mm patient motion that cannot be eliminated with simple means of external immobilization. We investigate a two-step iterative motion compensation based on a multi-component metric of image sharpness.

METHODS

Motion is considered with respect to locally rigid motion within a particular region of interest, and the method supports application to multiple locally rigid regions. Motion is estimated by maximizing a cost function with three components: a gradient metric encouraging image sharpness, an entropy term that favors high contrast and penalizes streaks, and a penalty term encouraging smooth motion. Motion compensation involved initial coarse estimation of gross motion followed by estimation of fine-scale displacements using high resolution reconstructions. The method was evaluated in simulations with synthetic motion (1-4 mm) applied to a wrist volume obtained on a CMOS-based CBCT testbench. Structural similarity index (SSIM) quantified the agreement between motion-compensated and static data. The algorithm was also tested on a motion contaminated patient scan from dedicated extremities CBCT.

RESULTS

Excellent correction was achieved for the investigated range of displacements, indicated by good visual agreement with the static data. 10-15% improvement in SSIM was attained for 2-4 mm motions. The compensation was robust against increasing motion (4% decrease in SSIM across the investigated range, compared to 14% with no compensation). Consistent performance was achieved across a range of noise levels. Significant mitigation of artifacts was shown in patient data.

CONCLUSION

The results indicate feasibility of image-based motion correction in extremities CBCT without the need for a priori motion models, external trackers, or fiducials.

SL4, a chalcone-based compound, induces apoptosis in human cancer cells by activation of the ROS/MAPK signalling pathway

OBJECTIVES

SL4, a chalcone-based compound, exhibits clearly inhibitory effects on HIF-1 and has been shown to effectively suppress tumour invasion and angiogenesis in vitro and in vivo. Here, studies were conducted to determine SL4's anti-apoptotic effects and its underlying mechanisms, in human cancer cells.

MATERIALS AND METHODS

Cytotoxicity, apoptotic induction and its involved mechanisms of SL4 were investigated using normal cells, cancer cells and mouse xenograft models. The role of reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) signalling in SL4-induced apoptosis was explored by manipulating specific scavenger or signalling inhibitors, in cultured cells.

RESULTS

SL4 significantly inhibited cell population growth of human cancer cell lines but exhibited lower cytotoxicity against normal cells. In addition, SL4 effectively induced apoptosis of Hep3B and MDA-MB-435 cells by activating procaspase-8, -9 and -3, and down-regulating expression levels of XIAP, but did not affect HIF-1 apoptosis-related targets, Survivin and Bcl-XL. Further study showed that SL4 also reduced mitochondrial membrane potential and promoted generation of ROS. ROS generation and apoptotic induction by SL4 were blocked by NAC, a scavenger of ROS, suggesting SL4-induced apoptosis via ROS accumulation. We also found that MAPKs, JNK and p38, but not ERK1/2, to be critical mediators in SL4-induced apoptosis. SP600125 and SB203580, specific inhibitors of JNK kinase and p38 kinase, significantly retarded apoptosis induced by SL4. Moreover, anti-oxidant NAC blocked activation of JNK and p38 induced by SL4, indicating that ROS may act as upstream signalling of JNK and p38 activation. It is noteworthy that animal studies revealed dramatic reduction (49%) in tumour volume after 11 days SL4 treatment.

CONCLUSIONS

These data demonstrate that SL4 induced apoptosis in human cancer cells through activation of the ROS/MAPK signalling pathway, suggesting that it may be a novel lead compound, as a cancer drug candidate, with polypharmacological characteristics.

Hemorrhagic cystitis after allogeneic hematopoietic cell transplantation: risk factors, graft source and survival

Although hemorrhagic cystitis (HC) is a common complication of allogeneic hematopoietic cell transplantation (alloHCT), its risk factors and effects on survival are not well known. We evaluated HC in a large cohort (n=1321, 2003-2012) receiving alloHCT from all graft sources, including umbilical cord blood (UCB). We compared HC patients with non-HC (control) patients and examined clinical variables at HC onset and resolution. Of these 1321 patients, 219 (16.6%) developed HC at a median of 22 days after alloHCT. BK viruria was detected in 90% of 109 tested HC patients. Median duration of HC was 27 days. At the time of HC diagnosis, acute GVHD, fever, severe thrombocytopenia and steroid use were more frequent than at the time of HC resolution. In univariate analysis, male sex, age <20 years, myeloablative conditioning with cyclophosphamide and acute GVHD were associated with HC. In multivariate analysis, HC was significantly more common in males and HLA-mismatched UCB graft recipients. Severe grade HC (grade III-IV) was associated with increased treatment-related mortality but not with overall survival at 1 year. HC remains hazardous and therefore better prophylaxis, and early interventions to limit its severity are still needed.

Combustion smoke-induced inflammation in the cerebellum and hippocampus of adult rats

AIMS

The effect of combustion smoke inhalation on the respiratory system is widely reported but its effects on the central nervous system remain unclear. Here, we aimed to determine the effects of smoke inhalation on the cerebellum and hippocampus which are areas vulnerable to hypoxia injury.

METHODS

Adult male Sprague-Dawley rats were subjected to combustion smoke inhalation and sacrificed at 0.5, 3, 24 and 72 h after exposure. The cerebellum and hippocampus were subjected to Western analysis for VEGF, iNOS, eNOS, nNOS and AQP4 expression; ELISA analysis for cytokine and chemokine levels; and immunohistochemistry for GFAP/AQP4, RECA-1/RITC and TUNEL. Aminoguanidine (AG) was administered to determine the effects of iNOS after smoke inhalation.

RESULTS

Both the cerebellum and hippocampus showed a significant increase in VEGF, iNOS, eNOS, nNOS and AQP4 expression with corresponding increases in inflammatory cytokines and chemokines and increased AQP4 expression and RITC permeability after smoke exposure. AG was able to decrease the expression of iNOS, followed by VEGF, eNOS, nNOS, RITC and AQP4 after smoke exposure. There was also a significant increase in TUNEL+ cells in the cerebellum and hippocampus which were not significantly reduced by AG. Beam walk test revealed immediate deficits after smoke inhalation which was attenuated with AG.

CONCLUSION

The findings suggest that iNOS plays a major role in the central nervous system inflammatory pathophysiology after smoke inhalation exposure with concomitant increase in proinflammatory molecules, vascular permeability and oedema, for which the cerebellum appears to be more vulnerable to smoke exposure than the hippocampus.