Improving children's cooperativeness during magnetic resonance imaging using interactive educational animated videos: a prospective, randomised, non-inferiority trial

INTRODUCTION

A previous prospective, randomised controlled trial showed that animated videos shown to children before magnetic resonance imaging (MRI) scan reduced the proportion of children needing repeated MRI sequences and improved confidence of the children staying still for at least 30 min. Children preferred the interactive video. We hypothesised that the interactive video is non-inferior to showing two videos (regular and interactive) in improving children's cooperativeness during MRI scans.

METHODS

In this Institutional Review Board-approved prospective, randomised, non-inferiority trial, 558 children aged 3-20 years scheduled for elective MRI scan from June 2017 to March 2019 were randomised into the interactive video only group and combined (regular and interactive) videos group. Children were shown the videos before their scan. Repeated MRI sequences, general anaesthesia (GA) requirement and improvement in confidence of staying still for at least 30 min were assessed.

RESULTS

In the interactive video group ( n = 277), 86 (31.0%) children needed repeated MRI sequences, two (0.7%) needed GA and the proportion of children who had confidence in staying still for more than 30 min increased by 22.1% after the video. In the combined videos group ( n = 281), 102 (36.3%) children needed repeated MRI sequences, six (2.1%) needed GA and the proportion of children who had confidence in staying still for more than 30 min increased by 23.2% after the videos; the results were not significantly different between the two groups.

CONCLUSION

The interactive video group demonstrated non-inferiority to the combined videos group.

A novel intronic variant in ROBO3 associated with horizontal gaze palsy with progressive scoliosis: case report and literature review

Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare, autosomal recessive inherited disorder caused by mutations in ROBO3 gene. The clinical features of HGPPS include horizontal gaze palsy, progressive scoliosis, other oculomotor abnormalities such as strabismus and nystagmus. Whole-exome sequencing (WES) is used to diagnose rare Mendelian disorders, when routine standard tests have failed to make a formal pathological diagnosis. However, WES may identify variants of uncertain significance (VUS) that may add further ambiguity to the diagnosis. We report the case of a 4-year-old boy with horizontal gaze palsy, progressive scoliosis, microcephaly, and mild developmental delay. WES identified an intronic VUS in ROBO3 gene. We performed minigene splicing functional analysis to confirm the pathogenicity of this VUS. This report illustrates that WES data analysis with supportive functional analysis provides an effective approach to improve the diagnostic yield for unsolved clinical cases. This case also highlights the phenotypic heterogeneity in patients with HGPPS.

Prediction of MYCN Gene Amplification in Pediatric Neuroblastomas: Development of a Deep Learning-Based Tool for Automatic Tumor Segmentation and Comparative Analysis of Computed Tomography-Based Radiomics Features Harmonization

OBJECTIVE

MYCN oncogene amplification is closely linked to high-grade neuroblastoma with poor prognosis. Accurate quantification is essential for risk assessment, which guides clinical decision making and disease management. This study proposes an end-to-end deep-learning framework for automatic tumor segmentation of pediatric neuroblastomas and radiomics features-based classification of MYCN gene amplification.

METHODS

Data from pretreatment contrast-enhanced computed tomography scans and MYCN status from 47 cases of pediatric neuroblastomas treated at a tertiary children's hospital from 2009 to 2020 were reviewed. Automated tumor segmentation and grading pipeline includes (1) a modified U-Net for tumor segmentation; (2) extraction of radiomic textural features; (3) feature-based ComBat harmonization for removal of variabilities across scanners; (4) feature selection using 2 approaches, namely, ( a ) an ensemble approach and ( b ) stepwise forward-and-backward selection method using logistic regression classifier; and (5) radiomics features-based classification of MYCN gene amplification using machine learning classifiers.

RESULTS

Median train/test Dice score for modified U-Net was 0.728/0.680. The top 3 features from the ensemble approach were neighborhood gray-tone difference matrix (NGTDM) busyness, NGTDM strength, and gray-level run-length matrix (GLRLM) low gray-level run emphasis, whereas those from the stepwise approach were GLRLM low gray-level run emphasis, GLRLM high gray-level run emphasis, and NGTDM coarseness. The top-performing tumor classification algorithm achieved a weighted F1 score of 97%, an area under the receiver operating characteristic curve of 96.9%, an accuracy of 96.97%, and a negative predictive value of 100%. Harmonization-based tumor classification improved the accuracy by 2% to 3% for all classifiers.

CONCLUSION

The proposed end-to-end framework achieved high accuracy for MYCN gene amplification status classification.

Corrigendum to "Should paediatric chest compression depth targets consider body habitus? - A chest computed tomography imaging study" [Resuscitation Plus 9 (2022) 100202]

[This corrects the article DOI: 10.1016/j.resplu.2022.100202.].

CT-based morphologic and radiomics features for the classification of MYCN gene amplification status in pediatric neuroblastoma

PURPOSE

MYCN onco-gene amplification in neuroblastoma confers patients to the high-risk disease category for which prognosis is poor and more aggressive multimodal treatment is indicated. This retrospective study leverages machine learning techniques to develop a computed tomography (CT)-based model incorporating semantic and non-semantic features for non-invasive prediction of MYCN amplification status in pediatric neuroblastoma.

METHODS

From 2009 to 2020, 54 pediatric patients treated for neuroblastoma at a specialized children's hospital with pre-treatment contrast-enhanced CT and MYCN status were identified (training cohort, n = 44; testing cohort, n = 10). Six morphologic features and 107 quantitative gray-level texture radiomics features extracted from manually drawn volume-of-interest were analyzed. Following feature selection and class balancing, the final predictive model was developed with eXtreme Gradient Boosting (XGBoost) algorithm. Accumulated local effects (ALE) plots were used to explore main effects of the predictive features. Tumor texture maps were also generated for visualization of radiomics features.

RESULTS

One morphologic and 2 radiomics features were selected for model building. The XGBoost model from the training cohort yielded an area under the receiver operating characteristics curve (AUC-ROC) of 0.930 (95% CI, 0.85-1.00), optimized F1-score of 0.878, and Matthews correlation coefficient (MCC) of 0.773. Evaluation on the testing cohort returned AUC-ROC of 0.880 (95% CI, 0.64-1.00), optimized F1-score of 0.933, and MCC of 0.764. ALE plots and texture maps showed higher "GreyLevelNonUniformity" values, lower "Strength" values, and higher number of image-defined risk factors contribute to higher predicted probability of MYCN amplification.

CONCLUSION

The machine learning model reliably classified MYCN amplification in pediatric neuroblastoma and shows potential as a surrogate imaging biomarker.

MEDB-10. Comparing pediatric medulloblastoma with and without spinal metastasis

AIM: To compare pediatric medulloblastoma with and without spinal metastasis

METHODOLOGY: Pediatric medulloblastoma cases from 1999 to 2021 were retrospectively reviewed in this Institutional Review Board approved study. Imaging reports, presence of spinal drop metastases at diagnosis, degree of tumor excision, treatment given and survival status were captured.

RESULTS: Brain and spine imaging at diagnosis was available in 54 medulloblastoma patients with no drop metastasis and in 7 with drop metastasis. Largest tumor dimension at presentation is 4.54 ± 0.94 cm with those with drop metastasis, similar to the 4.43 ± 0.94 cm in those without drop metastasis (p = 0.79). For the 54 medulloblastomas with no drop metastasis, 44 (81%) were completely excised, 9 (17%) partially excised and there was no follow up for 1. For the 7 medulloblastomas with drop metastasis, 3 (43%) of the primary tumours were completely excised, 3 (43%) partially excised and there was no follow up for 1. Post operative chemo/radiotherapy was given to 48 of the 54 with no drop metastasis, not given for 1 with no information available for 5. Chemo/radiotherapy was given to 6 of the 7 with drop metastasis with no information available for 1. At 1 year follow up of the 54 with no spinal drop metastasis at diagnosis , 42 remain tumour free, 3 have tumour, 4 are deceased and 5 are lost to follow up. At 1 year follow up of the 7 with drop metastasis, 2 are free of tumour, 2 have tumour and 3 are lost to follow up. Higher percentage of medulloblastomas without drop metastasis are completely excised (p<0.01). No significant difference between postoperative chemotherapy/radiation rates between groups

CONCLUSION: Most medulloblastomas do not have spinal drop metastasis at diagnosis and complete excision is more frequently in those without drop metastasis.

OTHR-10. Pilocytic astrocytoma with respect to treatment

AIM: To describe the sizes of pilocytic astrocytoma with respect to treatment Methodology Pediatric pilocytic astrocytomas cases from 2001 to 2021 were retrospectively reviewed in this Institutional Review Board approved study. Imaging reports, location of tumour, maximum dimension of tumour at diagnosis, treatment given (operation/chemotherapy/ radiotherapy), degree of tumor excision were captured. RESULTS: Imaging was available in 33 with 23 centered in the posterior fossa (1 extending into thalamus), 4 in suprasellar region, 2 in cerebral hemisphere, 2 in thalamus, 1 in pineal thalamic region and 1 in cervicomedullary spine, Tumor dimension at presentation was 5.40 cm ± 2.34 cm. Tumor size at presentation did not show significant correlation with age. 30 patients underwent operation with tumours completely excised in 15 and partially excised in 14 and no postoperative information for 1. Three patients, where tumour involved the thalamus, did not have operation and were given radiotherapy, average size of tumour being 3.47 + 1.15 cm. compared to the 5.59 + 2.34 size of tumours that underwent operation (p=0.06). Completely excised tumours measured 6.29 ± 2.04 cm at presentation while incompletely excised ones measured 4.76 ± 2.53 cm, not significantly different (p=0.09). Unoperated tumours are statistically smaller than those completely excised (p=0.02). One of the completetly excised tumours was located in the parietal cerebral hemisphere with the rest of the 15 in the posterior fossa. Seven of the incompletely excised tumours were located in the posterior fossa with 4 in suprasellar region, 1 in thalamus, 1 in spine and 1 in cerebral hemisphere. 3 patients with uncompletely excised tumours (1 cerebral, 1 post fossa, 1 spine) had post-operative radiation while 2 suprasellar tumours were given post-operative chemotherapy. CONCLUSION: Completely excised tumours are mainly located in posterior fossa. Tumours not operated on are located in thalamus and significantly smaller than tumours which are completely excised.

IMG-06. Comparing between MR spectroscopy done at 1.5T and 3T

INTRODUCTION: In hospitals with heavily utilised MRI scanners, it may not be possible to schedule the patient on 1 particular scanner for all scans and thus this project was carried out to determine if there is any significant difference in the spectroscopy profile between 1.5 T and 3T MRI scanners late year 2021. AIM: To describe the MR spectroscopy profile of normal brain tissue performed on 1.5T and 3T MRI scanners in KK Women’s and Children’s Hospital. METHODS: Three healthy adult volunteers with normal body mass index underwent MRI brain scans after informed consent in this Institute Review Board approved study. MRI brain scans were performed on 1.5T General Electric MRI scanner and 3T Siemens Skyra MRI scanner 1 week apart. NAA/Cr, Cho/Cr and Cho/ NAA values were obtained from the right and left cerebral hemispheres.

RESULTS: Average NAA/Cr in the right cerebral hemisphere is 2.06+/-0.10 at 1.5T. Average NAA/Cr in the left cerebral hemisphere is 2.01+/-0.23 at 1.5T. Average NAA/Cr in the right cerebral hemisphere is 1.56+/-0.09 at 3T. Average NAA/Cr in the left cerebral hemisphere is 1.81+/-0.29 at 3T. Average Cho/Cr in the right cerebral hemisphere 1.06+/-0.14 at 1.5T. Average Cho/Cr in the left cerebral hemisphere is 1.11+/-0.22 at 1.5T. Average Cho/Cr in the right cerebral hemisphere is 0.90+/-0.05 at 3T. Average Cho/Cr in the left cerebral hemisphere is 0.95+/-0.27 at 3T. Average Cho/NAA in the right cerebral hemisphere is 0.51+/-0.06 at 1.5T. Average Cho/NAA in the left cerebral hemisphere is 0.58+/-0.00 at 1.5T. Average Cho/NAA in the right cerebral hemisphere is 0.55+/-0.05 at 3T. Average Cho/NAA in the left cerebral hemisphere is 0.52+/-0.07 at 3T. CONCLUSION: MR spectroscopy values obtained from 1.5T and 3T MRI scanners show no significant difference(P>0.05).

Should paediatric chest compression depth targets consider body habitus? - A chest computed tomography imaging study

AIM

This study explored how body habitus in the paediatric population might potentially affect the use of one-third external anterior-posterior (APD) diameter when compared to age-appropriate absolute chest compression depth targets. It also explored how body habitus could potentially affect the relationship between one-third external and internal APD (compressible space) and if body habitus indices were independent predictors of internal APD at the lower half of the sternum.

METHODS

This was a secondary analysis of a retrospective study of chest computed tomography (CT) scans of infants and children (>24-hours-of-life to less-than-18-years-old) from 2005 to 2017. Patients' scan images were reviewed for internal and external APDs at the mid-point of the lower half of the sternum. Body habitus and epidemiological data were extracted from the electronic medical records.

RESULTS

Chest CT scans of 193 infants and 398 children were evaluated. There was poor concordance between one-third external APD measurements and age-specific absolute chest compression depth targets, especially in infants and overweight/obese adolescents. There was a co-dependent relationship between one-third external APD and internal APD measurements. Overweight/obese children's and adolescents' internal and external APDs were significant different from the normal/underweight groups. Body-mass-index (BMI) of children and adolescents (p = 0.009), but not weight-for-length (WFL) of infants (p = 0.511), was an independent predictor of internal APD at the compression landmark.

CONCLUSION

This study demonstrated correlations between external and internal APDs which were affected by BMI but not WFL (infants). Clinical studies are needed to validate current chest compression guidelines especially for infants and overweight/obese adolescents.(250 words).

Association of anesthetic and surgical risk factors with outcomes of initial diagnostic biopsies in a current cohort of children with anterior mediastinal masses

Background

Diagnostic biopsies of pediatric anterior mediastinal masses (AMMs) are high-risk procedures in which general anesthesia (GA) is traditionally avoided. However, awareness of historically recognized risk factors and corresponding perioperative management have improved over time and may now no longer strictly preclude the use of GA. Therefore, in this study, we examined the association of anesthetic and surgical risk factors and modalities with resulting procedural and survival outcomes in a current patient cohort.

Methods

We retrospectively reviewed charts of 35 children with AMMs who underwent initial diagnostic biopsies between January 2001 and August 2019, and determined tracheal compression and deviation from archival CT scans and procedural and disease outcomes.

Results

Twenty-three (65%) patients underwent GA while 12 (35%) received sedation. Among patients with available CT measurements, 13 of 25 (52%) had >50% anteroposterior tracheal diameter reduction. Patients with >50% anteroposterior tracheal compression received sedation more frequently (p=0.047) and were positioned upright (p=0.015) compared with patients with ≤50% compression, although 4 of 13 and 9 of 12, respectively, still received GA. Intraoperative adverse events (AEs) occurred in four (11.4%) patients: three received GA, and all were positioned supine or lateral. AEs were not associated with radiographic airway risk factors but were significantly associated with morphine and sevoflurane use (p<0.001) and with thoracoscopic biopsies (p=0.035). There were no on-table mortalities, but four delayed deaths occurred (three related to disease and one from late procedural complications).

Conclusions

In a current cohort of pediatric AMM biopsies, patients with >50% anteroposterior tracheal compression were more frequently managed with a conservative perioperative management strategy, though not completely excluding GA. The corresponding reduction in frequency of procedural AEs in this traditionally high-risk group suggests that increased awareness of procedural risk factors and appropriate risk-guided perioperative management choices may obviate the procedural mortality historically associated with pediatric AMM biopsies.

What is the potential for over-compression using current paediatric chest compression guidelines? - A chest computed tomography study

Aim

We explored the potential for over-compression from current paediatric chest compression depth guidelines using chest computed tomography(CT) images of a large, heterogenous, Asian population.

Methods

A retrospective review of consecutive children, less than 18-years old, with chest CT images performed between from 2005 to 2017 was done. Demographic data were extracted from the electronic medical records. Measurements for internal and external anterior-posterior diameters (APD) were taken at lower half of the sternum. Simulated chest compressions were performed to evaluate the proportion of the population with residual internal cavity dimensions less than 0 mm (RICD < 0 mm, representing definite over-compression; with chest compression depth exceeding internal APD), and RICD less than 10 mm (RICD < 10 mm, representing potential over-compression).

Results

592 paediatric chest CT studies were included for the study. Simulated chest compressions of one-third external APD had the least potential for over-compression; no infants and 0.3% children had potential over-compression (RICD < 10 mm). 4 cm simulated chest compressions led to 18% (95% CI 13%-24%) of infants with potential over-compression, and this increased to 34% (95% CI 27%-41%) at 4.4 cm (upper limit of "approximately" 4 cm; 4 cm + 10%). 5 cm simulated compressions resulted in 8% (95% CI 4%-12%) of children 1 to 8-years-old with potential over-compression, and this increased to 22% (95% CI 16%-28%) at 5.5 cm (upper limit of "approximately" 5 cm, 5 cm + 10%).

Conclusion

In settings whereby chest compression depths can be accurately measured, compressions at the current recommended chest compression of approximately 4 cm (in infants) and 5 cm (in young children) could result in potential for over-compression.

IMG-01. DWI RATIO OF HISTOLOGICAL MOLECULAR SUBTYPES OF PAEDIATRIC MEDULLOBLASTOMAS

AIM

To evaluate if diffusion weighted imaging (DWI) ratio on MRI is able to distinguish between the histological molecular subtypes of paediatric medulloblastomas.

MATERIALS AND METHODS

From 2002 to 2017, 38 cases of medulloblastoma with preoperative MRI available had histological subtyping performed with NanoString nCounter technology. The medulloblastomas were classified into 4 subtypes. There were 3 Sonic Hedgehog (SHH), 9 Wingless (WNT), 12 Group 3 and 14 Group 4 subtypes. Single operator manually outlined solid non-haemorrhagic component of the tumour on DWI images with largest axial tumour cross sectional diameter, correlating with the other MRI images (T1 pre and post contrast, SWI/GRE, FLAIR) to identify areas of haemorrhage. The same operator also drew region of interest to identify normal cerebellar tissue on the same axial images on which the tumour was outlined. All MRI images were obtained from the department’s Radiological Information System Picture Archiving and Communicating System (RIS PACS). DWI ratio for each case was obtained by dividing the values obtained from tumour by normal cerebellar tissue seen on the same axial image.

RESULTS

DWI ratio of all medullloblastomas is 1.34 +/- 0.18. DWI ratio of SHH subtype is 1.43 +/- 0.07. DWI ratio of WNT subtype is 1.40 +/- 0.07. DWI ratio of Group 3 subtype is 1.31 +/- 0.25. DWI ratio of Group 4 subtype is 1.30 +/- 0.17. There is no significant statistical differences in the DWI ratio between the various subtypes.

CONCLUSION

DWI ratio of medulloblastoma is unable to distinguish between the 4 medulloblastoma subtypes.

Role of a modified ultrafast MRI brain protocol in clinical paediatric neuroimaging

AIM

To establish a role for modified ultrafast magnetic resonance imaging (MRI) of the brain in clinical paediatric patients based on clinically acceptable image quality and diagnostic accuracy.

MATERIALS AND METHODS

A prospective study was conducted with institutional review board approval on an ultrafast MRI brain protocol consisting of sagittal T1-weighted, axial T2-weighted, axial fluid-attenuated inversion recovery (FLAIR), axial diffusion-weighted imaging (DWI), and axial T2∗-weighted sequences. Preliminary investigations revealed that the default ultrafast T2-weighted sequence was prone to pulsation artefacts. A modified ultrafast T2-weighted sequence was therefore developed to replace the default ultrafast T2-weighted sequence. Thirty-five patients with clinical indication for neuroimaging underwent ultrafast MRI, modified ultrafast T2-weighted sequence and standard MRI at 3 T. Image quality of ultrafast MRI sequences were graded as clinically "diagnostic" or "non-diagnostic" and compared against the corresponding standard MRI sequences as the reference standard. The modified ultrafast T2-weighted sequence surpassed the default ultrafast T2-weighted sequence in image quality. The ultrafast MRI protocol was therefore replaced with the modified ultrafast T2-weighted sequence creating a modified ultrafast MRI protocol. The clinical reports of modified ultrafast MRI were compared against standard MRI for diagnostic concordance, categorised further as "normal", "clinically significant", or "clinically minor" abnormalities.

RESULTS

Ultrafast T1-weighted, FLAIR, and DWI sequences had comparable image quality to standard MRI sequences. The ultrafast T2∗-weighted sequence had significantly higher non-diagnostic images (42.9%) compared to the standard MRI sequence (2.9%). The default ultrafast T2-weighted sequence had significantly higher non-diagnostic images compared to the modified ultrafast T2-weighted sequence and standard T2-weighted sequence (82.9%, 5.7%, 8.6%, respectively). There was 100% concordance for normal and clinically significant abnormalities and 23% discordance for clinically minor abnormalities. Modified ultrafast MRI takes 5 minutes 41 seconds compared to standard MRI time of 14 minutes 57 seconds.

CONCLUSION

The modified ultrafast MRI protocol for brain imaging demonstrates clinically acceptable image quality in four out of five sequences and has high accuracy in diagnosing normal and clinically significant abnormalities when compared against the standard MRI protocol for brain imaging. It could potentially benefit a select group of paediatric patients who require neuroimaging.

Cerebrospinal fluid cytokines in metastatic group 3 and 4 medulloblastoma

Background

Metastatic medulloblastoma (MB) portends a poor prognosis. Amongst the 4 molecular subtypes, Group 3 and Group 4 patients have a higher incidence of metastatic disease, especially involving the neuroaxis. At present, mechanisms underlying MB metastasis remain elusive. Separately, inflammation has been implicated as a key player in tumour development and metastasis. Cytokines and their inflammation-related partners have been demonstrated to act on autocrine and, or paracrine pathways within the tumour microenvironment for various cancers. In this study, the authors explore the involvement of cerebrospinal fluid (CSF) cytokines in Group 3 and 4 MB patients with disseminated disease.

Methods

This is an ethics approved, retrospective study of prospectively collected data based at a single institution. Patient clinicpathological data and corresponding bio-materials are collected after informed consent. All CSF samples are interrogated using a proteomic array. Resultant expression data of selected cytokines are correlated with each individual’s clinical information. Statistical analysis is employed to determine the significance of the expression of CSF cytokines in Group 3 and 4 patients with metastatic MB versus non-metastatic MB.

Results

A total of 10 patients are recruited for this study. Median age of the cohort is 6.6 years old. Based on Nanostring gene expression analysis, 5 patients have Group 3 as their molecular subtype and the remaining 5 are Group 4. There are 2 non-metastatic versus 3 metastatic patients within each molecular subtype. Proteomic CSF analysis of all patients for both subtypes show higher expression of CCL2 in the metastatic group versus the non-metastatic group. Within the Group 3 subtype, the MYC-amplified Group 3 MB patients with existing and delayed metastases express higher levels of CXCL1, IL6 and IL8 in their CSF specimens at initial presentation. Furthermore, a longitudinal study of metastatic Group 3 MB observes that selected cytokines are differentially expressed in MYC-amplified metastatic Group 3 MB, in comparison to the non-MYC amplified metastatic Group 3 MB patient.

Conclusion

This study demonstrates higher expression of selected CSF cytokines, in particular CCL2, in metastatic Group 3 and 4 MB patients. Although our results are preliminary, they establish a proof-of-concept basis for continued work in a larger cohort of patients affected by this devastating disease.

The most useful cranial ultrasound predictor of neurodevelopmental outcome at 2 years for preterm infants

AIM

To determine the most important cranial ultrasound predictors of abnormality associated with neurodevelopmental outcome at 2 years of age in preterm infants.

MATERIALS AND METHODS

A total of 343 preterm infants born between 2005 and 2010 and cared for in KK Women's and Children's Hospital, a tertiary paediatric hospital, with birth weight ≤1,250 g were assessed in this retrospective study. Serial cranial ultrasound examinations were examined for intraventricular haemorrhage and cystic periventricular leukomalacia. Ventricular-brain ratio on term equivalent cranial ultrasound was measured. Neurodevelopmental outcome was assessed by the performance on Bayley Scales of Infant and Toddler Development, 3^rd edition (Bayley-III) at 2 years corrected age. Mental delay was defined as having a combined Bayley-III score (the average of cognitive and language scores) <80.

RESULTS

The mean cognitive, language, and motor scores on Bayley-III in this cohort were 93±15, 83±18, and 92±15, respectively. Twenty-six percent of the preterm infants had mental delay and 4% had cerebral palsy. Ventricular-brain ratio >0.35 was the most significant factor associated with mental delay (odds ratio 5.28, 95% CI: 1.49-18.71, p=0.01). Other significant risk factors for mental delay were male gender, postnatal steroids, and necrotising enterocolitis, whereas maternal tertiary education was a protective factor against adverse outcome.

CONCLUSION

Ventricular-brain ratio >0.35 on term-equivalent cranial ultrasound in preterm infants is the strongest predictor for mental delay on Bayley score at 2 years of age.

Retroperitoneal tumors and congenital variations in vascular anatomy of retroperitoneal great vessels

BACKGROUND/OBJECTIVES

Variations in vascular anatomy (VIVAs) of the retroperitoneal great vessels are uncommon but can potentially complicate surgical procedures and negatively affect treatment outcomes, yet their incidence and clinical impact are poorly studied. We sought to assess the incidence and clinical impact of VIVAs of retroperitoneal great vessels in patients with retroperitoneal tumors.

METHODS

We retrospectively analyzed imaging, surgical, treatment and survival data of all pediatric patients with retroperitoneal tumors who underwent resection between January 2007 and October 2016, comparing preoperative scans with corresponding intraoperative observations, and subsequent surgical outcomes.

RESULTS

Among 66 children with renal, adrenal and paravertebral tumors, 6 (9%) had retroperitoneal VIVAs. Retroperitoneal VIVAs were present only with right-sided tumors and significantly associated with more frequent intraoperative complications (P = 0.013). While the presence of retroperitoneal VIVAs was not directly associated with survival outcomes, relapse was more frequent in patients with VIVAs (33%) than those without (18.3%, P = 0.378), and relapse was also associated with lower overall and event-free survival (P < 0.001).

CONCLUSIONS

VIVAs of retroperitoneal great vessels occurred in 9% of our patients with retroperitoneal tumors. Retroperitoneal VIVAs were associated with higher rates of intraoperative complications and disease relapse but was not directly related to survival outcomes.

TYPE OF STUDY

Retrospective review study.

LEVEL OF EVIDENCE

Level III Retrospective comparative study.

Using a checklist to assess if a child undergoing MRI needs general anaesthesia

AIM

To assess if a child-assessment checklist covering tasks children are expected to perform during magnetic resonance imaging (MRI) can determine whether the child requires general anaesthesia (GA) during MRI.

MATERIALS AND METHODS

In this institute review board approved study, children who underwent MRI from September 2016 to June 2017 at KK Women's and Children's Hospital were assessed using a checklist by a research assistant before their examination. During this project, the checklist had no influence on whether the MRI was performed under GA or not. The checklist consisted of five items rated on a binary scale assessing the child's behaviour. Binary logistic regression was performed separately on the overall sample and for a subset of younger children to identify variables associated with the requirement for GA.

RESULTS

The mean age of the overall sample (798 children) and the subset of children <8 years (124 children) were 11.7±3.7 and 5.5±1.3 years, respectively. In both groups, children who required GA were significantly younger than those who did not (p<0.001). No gender differences were observed. Children who required GA scored higher on the checklist compared to those who did not in both groups (p<0.001). The diagnostic accuracy of the checklist was found to be good (area under the curve [AUC]=0.97 for both groups), with a suggested cut-off score of 4. Intraclass correlation coefficient of the ratings by two independent individuals was 0.78.

CONCLUSION

The child assessment checklist was useful in identifying GA requirement in children undergoing MRI and can be administered by non-medical staff with good inter-rater reliability.

Altered Sensory Insular Connectivity in Chronic Postsurgical Pain Patients

Chronic postsurgical pain (CPSP) occurs in up to 50% of individuals after surgeries and 32% after hysterectomy, leading to major adverse effects on quality of life and socioeconomic burden. Little is known about whether and how large-scale neural networks being affected in CPSP, particularly with regard to the functional connectivity (FC) of insula which is known to be the hub of the intrinsic neural network playing a critical role in pain processing. Here, we sought to examine the dynamics of insular FC in the context of noxious stimuli in CPSP patients. To this aim, resting state fMRI data were acquired, before and after acute heat pain stimulation, from 11 individuals with chronic post-hysterectomy pain (CPHP) and 22 age-matched healthy controls (HCs) who had a hysterectomy but without chronic post-surgical pain. We examined whole-brain FC were mapped by seeding at the sensorimotor and chemosensory subfields of the insula and found significant group × stimulation interaction effects. Specifically, the HC group had increased FC between the left sensorimotor insula and right angular and middle occipital gyrus (MOG) and increased FC between the left chemosensory insula and bilateral angular and MOG following pain stimulation. In contrast, such pain stimulation related FC changes were absent in the CPHP group. Furthermore, higher insular FC at baseline and smaller increased insular FC after pain stimulation correlated with clinical pain scores in CPHP patients. Our findings suggest that CPSP is associated with altered dynamics of large-scale functional networks anchored in the insula.

General anesthesia / sedation requirement influences the way MRI brain scans are ordered in a tertiary pediatric hospital

BACKGROUND

MRI guidelines have been created to help clinicians order scans appropriately. Some scans in children are carried out under general anesthesia (GA) / sedation.

PURPOSE

To evaluate if the requirement for GA/sedation influences the way MRI brain scans are ordered.

STUDY TYPE

Retrospective.

POPULATION

Children with MRI brain scans in 2015 to 2017.

FIELD STRENGTH

3T, 1.5T.

ASSESSMENT

Institutional Review Board approval for waiver of consent was obtained. Clinical MRI brain reports for children were classified into whether they conformed to the American College of Radiology (ACR) 2013 guidelines by research assistants under supervision of a pediatric radiologist. Scans were sorted into those with normal brains or abnormality.

STATISTICAL TEST

The statistical difference between groups was assessed using t-test for continuous variables and chi-square test for categorical variables with IBM SPSS 19.

RESULTS

Of the total 1893 MRI scans, 431 were performed under GA and six under sedation. Of the 431 cases performed under GA/sedation, 383 (87.6%) were ordered according to guidelines. Of the 1456 cases that did not require GA/sedation, 710 (48.8%) conformed to guidelines. The percentage of scans ordered according to guidelines was 38.8% higher in those who had scans performed under GA/sedation (P < 0.001). MRI scans were normal in 635 (58.0%) out of the 1093 cases ordered according to guidelines and normal in 638 (79.8%) out of the 800 cases that did not follow guidelines. Scans not ordered according to guidelines had higher proportion of normal scans (21.8%) compared with those ordered according to guidelines (P < 0.001).

DATA CONCLUSION

Higher adherence to imaging guidelines is seen in younger patients who were exposed to the risks of GA/sedation for the MRI. Scans not adhering to guidelines had a higher percentage of having no brain abnormality detected.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 6 J. Magn. Reson. Imaging 2019;49:e250-e255.

Clinical Relevance of the Nonvisualized Appendix on Ultrasonography of the Abdomen in Children

OBJECTIVES

To evaluate the clinical relevance of the nonvisualized appendix on ultrasound imaging in children with right lower quadrant pain.

STUDY DESIGN

We reviewed 1359 children admitted for abdominal pain between January and December 2013 who had abdominal ultrasound imaging for right lower quadrant pain. Patients who had scans for genitourinary symptoms or intussusception were excluded from the study. When the appendix was not visualized, secondary signs indicating right lower quadrant inflammatory pathology were noted.

RESULTS

Of all admissions for abdominal pain, 810 had ultrasound scans. Thirty-eight did not evaluate the appendix and 131 were excluded for suspected intussusception, leaving 641 reports for children with a median age of 10.8 years (range, 1.3-21.3); 297 were boys (46.3%). There were 17 of 160 patients with a nonvisualized appendix (10.6%) who underwent appendectomy. Of these, 14 had secondary signs on ultrasound imaging and 3 (1.9%) had normal ultrasound reports. The 3 patients with normal ultrasound imaging had computed tomography imaging confirming appendicitis. There were 51 patients with a partially visualized appendix. The segment of appendix that could be seen was normal in 34 patients, none of whom had appendectomy. The remaining 17 had appendectomy, in whom the appendix seemed to be inflamed in 13 and equivocal in 4, all with histologically confirmed appendicitis. Overall, 232 children underwent appendectomy; 58 had no ultrasound imaging done, and 5 had a histologically normal appendix (overall negative appendectomy rate, 2.2%). Only 35 of 1359 patients (0.03%) had computed tomography scans.

CONCLUSION

In patients with a nonvisualized appendix on ultrasound imaging and no evidence of secondary inflammatory changes, the likelihood of appendicitis is less than 2%. Generous use of ultrasonography as an adjunct to clinical examination can achieve low negative appendectomy rates without underdiagnosis of acute appendicitis.

Review of congenital inner ear abnormalities on CT temporal bone

The aetiology of profound hearing loss in children is complex and multifactorial. Congenital inner ear abnormality is a major cause of hearing loss in children. CT temporal bone imaging is the modality of choice in the investigation of hearing loss. Recognising the congenital abnormalities of the inner ear guides the clinician's management of the condition. This pictorial essay illustrates the congenital abnormalities of the inner ear on high resolution CT temporal bone images and correlation with developmental arrest during embryology.

Clinics in diagnostic imaging (133). Retained placenta from an intra-abdominal pregnancy

A 29-year-old Indonesian woman presented with abdominal pain seven months after an intra-abdominal pregnancy. Ultrasonography revealed a cystic mass in the pelvis and magnetic resonance imaging showed an umbilical stump within it, indicating a retained placenta. This was removed surgically, and on histology, an infarcted placenta was confirmed.

Primitive neuroectodermal tumour metastases mimicking neurofibromatosis type 2

Bilateral vestibular schwannomas are the diagnostic features of neurofibromatosis type 2 (NF-2), and are the most common findings associated with the disorder. We report a three-year-old boy who presented with left facial nerve palsy and weight loss with bilateral large cerebellopontine (CP) angle masses that extended into the internal auditory canal on magnetic resonance imaging. The patient also had synchronous tumours in the lateral ventricle and intradural extramedullary spinal canal. The above findings were misinterpreted as NF-2 with bilateral vestibular schwannomas, ventricular meningioma and spinal schwannomas/meningiomas. However, histological examination of the spinal masses revealed a primitive neuroectodermal tumour. Although bilateral CP angle masses are characteristic of NF-2, the possibility of diffuse craniospinal malignancy should be considered in a very young child who presents with weight loss and extensive tumours.

Hypoxic Ischaemic Injury in an Immature Brain on MRI

The appearance of the child's brain on magnetic resonance imaging (MRI) differs with age. The manifestations of hypoxic ischaemic injury in the neonate on MRI also depend on the whether the child is premature or term and the duration/severity of injury. This case illustrates the typical MRI brain findings of a neonate who had experienced severe hypoxic ischaemic injury.

Magnetic Resonance Imaging of the Fetal Central Nervous System in Singapore

The dual energy CT (DECT) technology has been recently employed in the form of two X-ray sources of different energies to enhance the contrast between adjacent structures. Its use in the cardiac arena has been widely highlighted due to the higher temporal resolution. However, it may also be used in the craniocervical and peripheral vasculature for better differentiation between contrast-enhanced vascular lumina and calcified plaques, in the characterisation of ureteric stones, and in the evaluation of hepatic lesions. The objective of this paper is to revisit DECT physics, review the literature and discuss its use in CT neuroangiography with case illustrations from our institution, and impact on dose savings. Key words: Craniocervical CT angiography, Intracranial aneurysms, Radiation dosage, Vascular stenosis

Imaging Findings of Chronic Subluxation of the Os Odontoideum and Cervical Myelopathy in a Child with Beare-Stevenson Cutis Gyrata Syndrome after Surgery to the Head and Neck

Introduction: Although uncommon, fractures of the os odontoideum are known to occur in children under 7 years old, following acute trauma. Clinical Picture: We report a case of chronic subluxation of the os odontoideum resulting in cervical myelopathy in a child with Beare-Stevenson cutis gyrata syndrome after surgery to the head and neck. Treatment and Outcome: The patient was initially put in a Halo vest, following which occipital cervical fusion was performed. Conclusion: Subluxations and fractures at the odontoid synchondrosis are rare but should be anticipated in young children with risk factors for instability of the cervical spine. Key words: Myelopathy, Os odontoideum, Subluxation, Synchondrosis

Imaging findings of chronic subluxation of the os odontoideum and cervical myelopathy in a child with Beare-Stevenson cutis gyrata syndrome after surgery to the head and neck

INTRODUCTION

Although uncommon, fractures of the os odontoideum are known to occur in children under 7 years old, following acute trauma.

CLINICAL PICTURE

We report a case of chronic subluxation of the os odontoideum resulting in cervical myelopathy in a child with Beare-Stevenson cutis gyrata syndrome after surgery to the head and neck.

TREATMENT AND OUTCOME

The patient was initially put in a Halo vest, following which occipital cervical fusion was performed.

CONCLUSION

Subluxations and fractures at the odontoid synchondrosis are rare but should be anticipated in young children with risk factors for instability of the cervical spine.

Magnetic resonance imaging of the fetal central nervous system in Singapore

INTRODUCTION

Fetal imaging has improved with the development of faster magnetic resonance imaging (MRI) sequences, obviating the requirement for sedation. It is useful in characterising abnormality of the central nervous system in fetuses with abnormal or equivocal antenatal ultrasound findings. We reviewed all cases of fetal brain and spine MRI performed in our institution.

MATERIALS AND METHODS

All cases of fetal central nervous system MRI imaging from May 2006 to December 2008 were retrospectively reviewed, including fetal MRI, postnatal MRI and autopsy findings.

RESULTS

Thirty-one fetuses were imaged with MRI for evaluation of the central nervous system of which 3 were specifically for spinal evaluation. On fetal MRI, there were 11 normal fetuses (2 with minor ventricular asymmetry), 4 fetuses with minor ventriculomegaly and 16 fetuses with significant abnormalities. Twenty-three fetuses were delivered and 8 were terminated. Fifteen of 23 babies underwent postnatal imaging, 21 had clinical follow-up and 2 were lost to clinical follow-up. Of the 11 fetuses reported as normal on fetal MRI, 3 had additional postnatal findings. A fetus with a megacisterna magna on fetal MRI was diagnosed with a posterior fossa arachnoid cyst on postnatal MRI. One, who had fetal MRI to assess suspected absent inferior cerebellar vermis, had intracranial calcifications from rubella infection. One was diagnosed with cerebro-occular-facio-skeletal (COFS) syndrome postnatally, 1 was lost to follow-up and the rest were discharged well. Seven out of 16 fetuses with significantly abnormal fetal MRI findings had confirmation of the findings on postnatal imaging. Postnatal MRI detected 2 cases of polymicrogyria which were not seen on fetal MRI. Autopsy was available in 1 abortus confirming intrauterine diagnosis of Dandy Walker malformation. A myelomeningocele was clinically obvious in 1 abortus.

CONCLUSION

Fetal MRI is a good method of assessing brain and spine abnormalities in utero. However, disorders of neuronal migration remain a challenging diagnostic problem in fetal imaging.

Imaging of accidental paediatric head trauma

Head trauma is the most common form of injury sustained in serious childhood trauma and remains one of the top three causes of death despite improved road planning and safety laws. CT remains the first-line investigation for paediatric head trauma, although MRI may be more sensitive at picking up the full extent of injuries and may be useful for prognosis. Follow-up imaging should be tailored to answer the specific clinical question and to look for possible complications.

Primary neuroblastoma of the mandible

Primary neuroblastoma of the mandible is rare with only seven cases reported to date. The diagnosis is made after any possible primary tumour has been adequately investigated for and excluded. We report a one-year nine-month-old girl with a primary neuroblastoma of the mandible and discuss its possible aetiology.

Agenesis of the corpus callosum: an MR imaging analysis of associated abnormalities in the fetus

BACKGROUND AND PURPOSE

Anomalies associated with callosal agenesis (ACC) found postnatally have been well documented. However, to our knowledge, no detailed MR imaging analysis of associated anomalies has been reported in a large cohort of fetuses with ACC. This study will assess those anomalies and compare them with postnatal cohorts of ACC, to identify associated fetal brain abnormalities that may give insight into etiology and outcome.

MATERIALS AND METHODS

All cases of ACC diagnosed on fetal MR imaging during an 11-year period were retrospectively reviewed, including fetal MR imaging, postnatal MR imaging, and autopsy findings. Neurodevelopmental outcome was classified as poor in children with seizures and/or severe neurodevelopmental impairment or in cases of neonatal death.

RESULTS

Twenty-nine cases of ACC were identified. Median gestational age was 26.14 weeks (range, 19.71-36.43 weeks). Twenty-three fetuses had delayed sulcation and/or too-numerous cortical infoldings (abnormal morphology). Fifteen fetuses had cerebellar and/or brain stem abnormalities. Fetal MR imaging findings suggested a genetic syndrome in 5 fetuses and an acquired etiology or genetic/metabolic disorder in 2 fetuses. Findings were confirmed in 8 cases with postnatal MR imaging, except for delayed sulcation and small vermis, and in 4 cases with autopsy, except for periventricular nodular heterotopia and abnormalities in areas not examined by autopsy. Neurodevelopmental outcome was good in 7 and poor in 9 children. Abnormal sulcal morphology and/or infratentorial abnormalities were present in those with poor outcome and absent in those with good outcome.

CONCLUSIONS

ACC is infrequently isolated in fetuses. Abnormal sulcation is common and suggests more diffuse white matter dysgenesis in these fetuses.

Superior Sagittal Sinus Thrombosis: Subtle Signs on Neuroimaging

Introduction: The aim of this study was to review the clinical, computed tomography (CT) and magnetic resonance imaging (MRI) diagnosis and the frequency of positive neuroimaging findings in patients with cerebral venous thrombosis (CVT) involving the superior sagittal sinus. Materials and Methods: A clinical and radiological database of patients with final diagnosis of CVT was compiled from the inpatient hospital information service of a tertiary neurological hospital over 5 years. CT and MRI studies in 22 patients were retrospectively examined for direct signs of venous sinus thrombosis and for complications of CVT. The diagnosis of CVT before and after CT and MRI was reviewed. Results: Clinical diagnosis of possible CVT was suspected in only 1 patient. When the diagnosis was not suspected, CT diagnosis was difficult and there was a high false negative rate of 52.6%. MRI fared better, but the false negative rate was still 11%. Directs signs of venous sinus thrombosis such as the triangle sign, empty delta sign on CT and loss of the normal flow voids on MRI, could be retrospectively detected in 57.9%, 100% and 100% of patients respectively. Although 4 patients presented with subarachnoid haemorrhage, these direct signs were present in 3 patients. Conclusion: Clinical diagnosis of CVT is rarely suspected before CT and MRI, and although subtle positive signs are often present, these may not be appreciated unless there is a high index of suspicion or image review at multidisciplinary team meetings. Key words: Cerebrovascular disorders, Cerebral venous thrombosis, Magnetic resonance imaging, Venous infarction

Superior sagittal sinus thrombosis: subtle signs on neuroimaging

INTRODUCTION

The aim of this study was to review the clinical, computed tomography (CT) and magnetic resonance imaging (MRI) diagnosis and the frequency of positive neuroimaging findings in patients with cerebral venous thrombosis (CVT) involving the superior sagittal sinus.

MATERIALS AND METHODS

A clinical and radiological database of patients with final diagnosis of CVT was compiled from the inpatient hospital information service of a tertiary neurological hospital over 5 years. CT and MRI studies in 22 patients were retrospectively examined for direct signs of venous sinus thrombosis and for complications of CVT. The diagnosis of CVT before and after CT and MRI was reviewed.

RESULTS

Clinical diagnosis of possible CVT was suspected in only 1 patient. When the diagnosis was not suspected, CT diagnosis was difficult and there was a high false negative rate of 52.6%. MRI fared better, but the false negative rate was still 11%. Directs signs of venous sinus thrombosis such as the triangle sign, empty delta sign on CT and loss of the normal flow voids on MRI, could be retrospectively detected in 57.9%, 100% and 100% of patients respectively. Although 4 patients presented with subarachnoid haemorrhage, these direct signs were present in 3 patients.

CONCLUSION

Clinical diagnosis of CVT is rarely suspected before CT and MRI, and although subtle positive signs are often present, these may not be appreciated unless there is a high index of suspicion or image review at multidisciplinary team meetings.

Indiscernible benefit of high-resolution HLA typing in improving long-term clinical outcome of unrelated umbilical cord blood transplant

The success of allogeneic hematopoietic stem cell transplantation depends in part on the accuracy of human leukocyte antigen (HLA) matching between the donor-recipient pair. The higher the number of matching HLA alleles, the smaller the chance that the transplant recipient will develop complications. Umbilical cord blood (UCB) transplantation was noted to result in a remarkably low frequency and severity of graft-versus-host disease (GvHD) and graft rejection compared to that in unrelated bone marrow transplant recipients. At present most banks match UCB donors for respective recipients by HLA-A, -B low-resolution typing and -DRB1 high-resolution typing. We retrospectively conducted high-resolution sequence-based HLA typing on DNA samples available from 65 Chinese UCB-recipient pairs typed previously by using low-resolution sequence-specific oligonucleotide probes and sequence-specific primers, and evaluated the clinical outcome. High-resolution typing revealed imperceptible HLA alleles that were hardly identified in low-resolution typing. Univariate analyses demonstrated no significant correlation between the extents of high-resolution HLA disparity with engraftment, graft failure, acute GvHD, transplant-related mortality and long-term 6-year overall survival. Data from the study suggest that high-resolution typing for HLA-A, -B and -DRB1 contributed no substantial improvement to UCB transplant outcome. Low-resolution typing appears to be amenable to matching UCB-recipient pairs without compromising the quality of transplant.

Hysterosalpingography: current applications

With the recent advances in reproductive medicine, hysterosalpingography has become a relatively quick and noninvasive examination to evaluate fallopian tubes and uterine cavity. It remains the best modality to image fallopian tubes. Congenital uterine malformations, technical artefacts and pathological findings are depicted. Pathological findings that can be detected on hysterosalpingography include salpingitis isthmica nodosa, tubal blockage, peritubal adhesion, submucosal leiomyoma, endometrial polyp, endometrial carcinoma, synechiae and adenomyosis.

Banking and transplantation of umbilical cord blood in Guangzhou, China

BACKGROUND

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSC) for transplantation of patients with hematologic malignancies or hereditary diseases.

METHODS

We developed a provincial UCB bank in Guangzhou, China, using good manufacturing practices and standard operating procedures to address donor eligibility, collection, characterization, processing, storage and release from quarantine. The banking activities were analyzed.

RESULTS

From June 1998 to May 2005, 8623 UCB units of Han ethnic origin were collected; 4147 (48.1%) were stored, while 4476 (51.9%) were discarded as a result of pre-determined exclusion criteria. A median volume of 95.5 mL (range 60-227.7) and 1.2 x 10(9) (0.8-9.3) nucleated cells were collected. The cell viability was 97.8% (90-100%). The CD34+ cell count of 3691 (89.0%) UCB units was 5.2 x 10(6) (0.3-131.6) and clonogenic assays of 4036 (97.3%) UCB units demonstrated 9.8 x 10(5) (0.04-135.8) CFU-GM, 0.3 x 10(5) (0.0-18.6) CFU-GEMM and 8.8 x 10(5) (0.0-74.2) BFU-E. A total of 0.4% (15/3863) UCB derived from babies known to have health problems at age 6 months was discarded. Up to May 2005, 151 units were issued for transplantation to 127 patients [90 (70.9%) children and 37 (29.1%) adults]. The infused nucleated cells in unrelated single-unit recipients were 3.4 x 10(7)/kg (1.7-14.9) for adults (n=19) and 5.7 x 10(7)/kg (2.0-20.5) for children (n=71), respectively. The numbers of days for the engraftment of neutrophils among 65 children and 22 adults were 17 (7-41) and 20 (10-42), respectively.

DISCUSSION

Data of this study show that stringent procedures and comprehensive policies are requisite for pursuing the banking and release of quality UCB for successful transplantation.

Biological features of mesenchymal stem cells from human bone marrow

OBJECTIVE

To study the biological characteristics of mesenchymal stem cells (MSCs) from human bone marrow.

METHODS

A culture of mesenchymal stem cells was initiated from bone marrow low-density mononuclear cells separated by Percoll Centrifugation and maintained in low-glucose Dulbecco's modified Eagle's medium (DMEM) with 10% selected fetal calf serum. Cell growth pattern and its responses to cytokines were evaluated by trypan blue exclusion and MTT test, respectively. Cell cycle and surface antigenic features were analyzed by flow cytometry technique. Cytochemistry characteristics of MSCs were determined.

RESULTS

Easy-handling methods to isolate and culture expand MSCs were developed in this study. MSCs were unique in their phenotypes. They were positive for CD29, CD44, CD166, and negative for CD34, CD45, HLA-DR and Ulex europaeus. Cytochemistry evaluation showed that MSCs were homogeneously positive for acid alpha-naphthl acetate esterase (ANAE), glycogen (periodic acid Schiff reaction, PAS), and negative for acid phosphatase (ACP) and the Sudan black reaction (SB). Around 5% of them were positive for alkaline phosphatase (ALP). The cells had a population doubling time of 30 hours and cell cycle analysis showed that approximately 10% of them were in S phase. MSCs grew at significantly different rates when incubated in the presence of various recombinant human cytokines, of which interferon gamma, tumor necrosis factor alpha, stem cell factor and insulin-like growth factor promoted the proliferation of MSCs dramatically, while others tested had no effects on cell growth.

CONCLUSIONS

MSCs are a homogenous population of cells that have unique growth, phenotypical and cytochemical characteristics. Furthermore, the diverse responses of MSCs to different cytokines provide a clue for the selection of optimal expansion and maintenance of MSCs.

Protective effect of human CD40-Ig fusion protein in a murine model of acute graft-versus-host disease

OBJECTIVE

To investigate the protective effects of blocking CD40/CD40L interactions with human CD40-Ig fusion protein in a murine graft-versus-host disease model.

METHODS

Human CD40 gene extracellular region was inserted into plasmid pIG1, which contains genomic human IgG1 Fc gene. A transient vector containing CD40-Fc fusion gene was transfected into COS-7 cells. The CD40-Ig fusion protein was detected through enzyme-linked immunosorbent assay (ELISA). A constitutive vector was also generated by ligating the CD40-Fc fusion gene into pcDNA3.1 and transfecting it into CHO cells. CD40-Ig was purified by protein A affinity chromatography. SDS-PAGE, Western blot and ligand binding assay were used to identify the qualities of CD40-Ig. Murine acute graft-versus-host disease (GVHD) was induced by intravenous injection of C57BL/6J (H-2b) spleen cells into sub-lethally irradiated BALB/c (H-2d) mice. Protective effects against murine graft-versus-host disease by in vivo administration of CD40-Ig were evaluated.

RESULTS

Mammalian expression vectors pIG/40Ig and p3.1/40Ig were constructed as described above. Chimeric proteins were expressed in COS-7 and CHO cell culture supernatant and confirmed by ELISA and Western blot. SDS-PAGE showed that fusion proteins had a disulfide-bonded dimeric structure and existed as homodimer. Purified CD40-Ig could bind to CD40L. In vivo administration of CD40-Ig could prevent the development of GVHD and significantly prolong the mean survival time of mice with graft-versus-host disease.

CONCLUSIONS

These results demonstrate that CD40/CD40L interactions play an important role in the pathogenesis of graft-versus-host disease and suggest clinical potential for CD40-Ig in the prevention and treatment of human graft-versus-host disease.

[The transfection and expression of retro viral-mediated human FL cDNA in bone marrow stromal cell line]

AIM

The expression of retroviral-mediated FL gene transfer into bone marrow stromal cell line HFCL was studied.

METHODS

FLT3 ligand (FL) cDNA was recombined with retroviral vector pLXSN by gene recombination technology. The recombinant plasmid was transferred into retrovirus packaging cell line PA3 17 by lipofectamine, and the resistant clones were selected by G418 selective medium. The mRNA expression in HFCL cells and integration of genome DNA were assayed by RT-PCR and genomic DNA PCR. The biological activity of FL in the culture was investigated by mouse bone marrow CFU-GM assay.

RESULTS

The recombinant plasmid pLFSN was successfully constructed. The expression of FL mRNA was detected in HFCL cells. In the genome of these infected target cells, neo gene and FL cDNA were successfully expressed. The biological activity of FL in the culture demonstrated that HFCL cells transfected with FL could significantly augment FL in vitro.

CONCLUSION

These results suggest that bone marrow stromal cell lines might become target cells of gene therapy.

HPLC analysis of reduced and oxidized coenzyme Q(10) in human plasma

BACKGROUND

The percentage of reduced coenzyme Q(10) (CoQ(10)H(2)) in total coenzyme Q(10) (TQ(10)) is decreased in plasma of patients with prematurity, hyperlipidemia, and liver disease. CoQ(10)H(2) is, however, easily oxidized and difficult to measure, and therefore reliable quantification of plasma CoQ(10)H(2) is of clinical importance.

METHODS

Venous blood was collected into evacuated tubes containing heparin, which were immediately placed on ice and promptly centrifuged at 4 degrees C. The plasma was harvested and stored in screw-top polypropylene tubes at -80 degrees C until analysis. After extraction with 1-propanol and centrifugation, the supernatant was injected directly into an HPLC system with coulometric detection.

RESULTS

The in-line reduction procedure permitted transformation of CoQ(10) into CoQ(10)H(2) and avoided artifactual oxidation of CoQ(10)H(2). The electrochemical reduction yielded 99% CoQ(10)H(2). Only 100 microL of plasma was required to simultaneously measure CoQ(10)H(2) and CoQ(10) over an analytical range of 10 microg/L to 4 mg/L. Intra- and interassay CVs for CoQ(10) in human plasma were 1.2-4.9% across this range. Analytical recoveries were 95.8-101.0%. The percentage of CoQ(10)H(2) in TQ(10) was approximately 96% in apparently healthy individuals. The method allowed analysis of up to 40 samples within an 8-h period.

CONCLUSIONS

This optimized method for CoQ(10)H(2) analysis provides rapid and precise results with the potential for high throughput. This method is specific and sufficiently sensitive for use in both clinical and research laboratories.

A community study of male androgenetic alopecia in Bishan, Singapore

BACKGROUND

Androgenetic alopecia is the most common form of hair loss. It affects a large number of the local male population, with 1,812 men seeking treatment for hair loss at the sole dermatological tertiary referral centre in Singapore in 1994. The aim of this study was to assess the prevalence of male androgenetic alopecia in the community.

METHODS

A questionnaire-based cross-sectional survey with a one-stage sampling method was conducted. Each male was diagnosed clinically and the severity graded according to the Norwood Criteria. The survey area was in Bishan East, a housing estate with 8,004 households. A total of 335 households were selected for the survey.

RESULTS

The household response rate was 84%. Within these households, 254 out of 378 men participated in the study (67% response rate). The prevalence of androgenetic alopecia was found to be 63%. The prevalence of the condition increased with age, from 32% among young adults aged 17 to 26 years to 100% among those in their 80s. Proportionately more Indians (87%) were affected compared to Chinese (61%). 81% of the respondents with androgenetic alopecia did not seek help as they did not view it as a problem. Of those seeking treatment, 74% used non-medical methods of unproven effectiveness.

CONCLUSION

There is a high prevalence of androgenetic alopecia in the community in Singapore. Age specific prevalence and racial differences correlate well with both Western and local studies respectively.

An improved gas chromatography assay for topiramate monitoring in pediatric patients

An improved micromethod involving capillary gas chromatographic assay with liquid-liquid extraction and nitrogen phosphorus detection (GC/NPD) was developed and validated for the determination of topiramate (TPM) in human body fluids. The galactopyranose analog of TPM was used as the internal standard. Capillary gas chromatographic conditions yielded typical retention times of 6.8 min for TPM and 7.2 min for the internal standard. Calibrations were linear between 1.0 and 32 microg/mL. Between-day precision (n = 17) for three serum controls (3.0, 10, and 24.5 microg/mL) resulted in coefficients of variation of 6.9%, 7.3%, and 4.9%, respectively. The limit of detection was 0.42 microg/mL. There was an excellent linear correlation between the fluorescence-polarization immunoassay (FPIA) and GC/NPD determinations of 56 patient specimens (r2 = 0.981). Chromatograms showed no interfering peaks with the respective blank human samples or from many commonly prescribed drugs. Because of improved specificity and decreased sample volume requirements, this micromethod should be particularly useful for monitoring TPM therapy in pediatric patients, for patients with impaired renal function, and for research studies.