Longitudinal reproducibility and accuracy of pseudo-continuous arterial spin-labeled perfusion MR imaging in typically developing children

PURPOSE

To evaluate the longitudinal repeatability and accuracy of cerebral blood flow (CBF) measurements by using pseudo-continuous arterial spin-labeled (pCASL) perfusion magnetic resonance (MR) imaging in typically developing children.

MATERIALS AND METHODS

Institutional review board approval with HIPAA compliance and informed consent were obtained. Twenty-two children aged 7-17 years underwent repeated pCASL examinations 2-4 weeks apart with a 3-T MR imager, along with in vivo blood T1 and arterial transit time measurements. Phase-contrast (PC) MR imaging was performed as the reference standard for global blood flow volume. Intraclass correlation coefficient (ICC) and within-subject coefficient of variation (wsCV) were used to evaluate accuracy and repeatability.

RESULTS

The accuracy of pCASL against the reference standard of PC MR imaging increased on incorporating subjectwise in vivo blood T1 measurement (ICC: 0.32 vs 0.58). The ICC further increased to 0.65 by using a population-based model of blood T1. Additionally, CBF measurements with use of pCASL demonstrated a moderate to good level of longitudinal repeatability in whole brain (ICC = 0.61, wsCV = 15%), in gray matter (ICC = 0.65, wsCV = 14%), and across 16 brain regions (mean ICC = 0.55, wsCV = 17%). The mean arterial transit time was 1538 msec ± 123 (standard deviation) in the pediatric cohort studied, which showed an increasing trend with age (P = .043).

CONCLUSION

Incorporating developmental changes in blood T1 is important for improving the accuracy of pCASL CBF measurements in children and adolescents; the noninvasive nature, accuracy, and longitudinal repeatability should facilitate the use of pCASL perfusion MR imaging in neurodevelopmental studies.

Meta-analysis of cause of death following total joint replacement using different thromboprophylaxis regimens

We performed a meta-analysis of modern total joint replacement (TJR) to determine the post-operative mortality and the cause of death using different thromboprophylactic regimens as follows: 1) no routine chemothromboprophylaxis (NRC); 2) Potent anticoagulation (PA) (unfractionated or low-molecular-weight heparin, ximelagatran, fondaparinux or rivaroxaban); 3) Potent anticoagulation combined (PAC) with regional anaesthesia and/or pneumatic compression devices (PCDs); 4) Warfarin (W); 5) Warfarin combined (WAC) with regional anaesthesia and/or PCD; and 6) Multimodal (MM) prophylaxis, including regional anaesthesia, PCDs and aspirin in low-risk patients. Cause of death was classified as autopsy proven, clinically certain or unknown. Deaths were grouped into cardiopulmonary excluding pulmonary embolism (PE), PE, bleeding-related, gastrointestinal, central nervous system, and others (miscellaneous). Meta-analysis based on fixed effects or random effects models was used for pooling incidence data. In all, 70 studies were included (99 441 patients; 373 deaths). The mortality was lowest in the MM (0.2%) and WC (0.2%) groups. The most frequent cause of death was cardiopulmonary (47.9%), followed by PE (25.4%) and bleeding (8.9%). The proportion of deaths due to PE was not significantly affected by the thromboprophylaxis regimen (PA, 35.5%; PAC, 28%; MM, 23.2%; and NRC, 16.3%). Fatal bleeding was higher in groups relying on the use of anticoagulation (W, 33.8%; PA, 9.4%; PAC, 10.8%) but the differences were not statistically significant. Our study demonstrated that the routine use of PA does not reduce the overall mortality or the proportion of deaths due to PE.

Assessing professionalism within dental education; the need for a definition

Professionalism is a broad competency needed by dentists to act effectively and efficiently and is seen as a central part of both undergraduate and postgraduate curricula. Assessment is vital in education to assess progress and direct future learning. It is also an essential part of good professional regulation, which depends upon high quality assessment to maintain credibility. Educators must produce clear expectations that students can strive for. Thus dental educators are required to understand precisely what is meant by "professionalism" in relation to dentistry in order to both teach and assess it. The aim of this paper is to explain the importance of professionalism, explore its features and its assessment as described in the literature. The paper concludes that without a validated definition of this construct, assessment of professionalism within dental education will be compromised.

Hard x-ray monochromator with milli-electron volt bandwidth for high-resolution diffraction studies of diamond crystals

We report on design and performance of a high-resolution x-ray monochromator with a spectral bandwidth of ΔE(X) ≃ 1.5 meV, which operates at x-ray energies in the vicinity of the backscattering (Bragg) energy E(H) = 13.903 keV of the (008) reflection in diamond. The monochromator is utilized for high-energy-resolution diffraction characterization of diamond crystals as elements of advanced x-ray crystal optics for synchrotrons and x-ray free-electron lasers. The monochromator and the related controls are made portable such that they can be installed and operated at any appropriate synchrotron beamline equipped with a pre-monochromator.

First clinical use of a novel neurovascular access and neuroprotection system demonstrates complete absence of emboli by transcranial Doppler during carotid artery stenting

This article focuses on the first use of the MICHI™ Neuroprotection System in a transcervical carotid artery stenting procedure. The patient presented with an asymptomatic, 80% stenosis of the right internal carotid artery extending into the common carotid artery. The lesion was successfully treated with transcervical carotid access and reverse flow embolic protection and the successful placement of a carotid stent followed by balloon post-dilatation. Transcranial Doppler monitoring was performed throughout the procedure and a total of two micro embolic signals were recorded over the 30 minute procedural period. There were no neurologic complications reported during the 30-day follow-up period.

Abstract C108: An expanded imaging cohort of pazopanib in children and adolescents with relapsed or refractory soft tissue sarcoma (ADVL0815): A Children's Oncology Group phase I consortium trial

Background: Pazopanib (NCT00929903) is an orally available small molecule inhibitor of VEGFR 1–3, PDGFR α/β, and c-kit, which has been shown to prolong progression free survival in adults with soft tissue sarcoma (STS). Following a standard phase I dose escalation trial to determine the pediatric maximum tolerated dose (MTD), an expanded cohort of children and adolescents with relapsed and refractory STS and at least one lesion amenable to dynamic contrast enhanced MRI (DCE-MRI) was studied to explore changes in tumor blood volume and vascular permeability following initiation of pazopanib, and to correlate these changes with clinical outcome.

Methods: Oral pazopanib was administered at 450mg/m2 once daily in 28 day cycles, for up to 24 cycles. DCE-MRI scans were obtained at baseline and within 15 × 2 days after initiation of pazopanib. DCE-MRI data sets were analyzed using a two compartment kinetic model yielding estimates of fractional blood volume and the permeability transfer constant (Ki).

Results: 10 subjects were enrolled [5 male; median age 17 yrs (range, 8–23)], of whom 8 had paired DCE-MRI scans of sufficient quality to be evaluable. Subjects received a median of 4 cycles (range 1–7; 3 remain on study receiving courses 6, 7 and 8). One subject had a dose limiting toxicity of Gr3 back and extremity pain with Gr3 sensory neuropathy. Other non-dose limiting toxicities occurring in >10% of subjects (n=10) during the first cycle included mild myelosuppression, sinus bradycardia, fatigue, diarrhea, nausea, vomiting, anorexia, dehydration, dizziness, headache, liver transaminase elevation and hyperglycemia. All subjects with evaluable DCE-MRI (n=8) experienced a decrease in tumor blood volume following initiation of pazopanib, with a mean pre-treatment level of 16% (range 1–29%) versus 7% (0–15%) post-treatment (p<0.01). Similarly all subjects had a decrease in Ki with mean pretreatment values of 7.74 (range 2.31–20.38) ml/100g/min, decreasing post-treatment to 4.28 (range 0.19–12.60) ml/100g/min (p<0.01). Although limited by the small sample size, there is a suggestion that patients with best response of stable disease appear to have lower tumor blood volume at baseline than those with progressive disease.

Conclusions: DCE-MRI changes in tumor blood volume and Ki in pediatric and adolescent patients with soft tissue sarcoma are supportive of physiological activity and the antiangiogenic mechanism of pazopanib.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C108.

Hysterectomy, endometrial ablation and Mirena® for heavy menstrual bleeding: a systematic review of clinical effectiveness and cost-effectiveness analysis

OBJECTIVE

The aim of this project was to determine the clinical effectiveness and cost-effectiveness of hysterectomy, first- and second-generation endometrial ablation (EA), and Mirena® (Bayer Healthcare Pharmaceuticals, Pittsburgh, PA, USA) for the treatment of heavy menstrual bleeding.

DESIGN

Individual patient data (IPD) meta-analysis of existing randomised controlled trials to determine the short- to medium-term effects of hysterectomy, EA and Mirena. A population-based retrospective cohort study based on record linkage to investigate the long-term effects of ablative techniques and hysterectomy in terms of failure rates and complications. Cost-effectiveness analysis of hysterectomy versus first- and second-generation ablative techniques and Mirena.

SETTING

Data from women treated for heavy menstrual bleeding were obtained from national and international trials. Scottish national data were obtained from the Scottish Information Services Division.

PARTICIPANTS

Women who were undergoing treatment for heavy menstrual bleeding were included.

INTERVENTIONS

Hysterectomy, first- and second-generation EA, and Mirena.

MAIN OUTCOME MEASURES

Satisfaction, recurrence of symptoms, further surgery and costs.

RESULTS

Data from randomised trials indicated that at 12 months more women were dissatisfied with first-generation EA than hysterectomy [odds ratio (OR): 2.46, 95% confidence interval (CI) 1.54 to 3.93; p = 0.0002), but hospital stay [WMD (weighted mean difference) 3.0 days, 95% CI 2.9 to 3.1 days; p < 0.00001] and time to resumption of normal activities (WMD 5.2 days, 95% CI 4.7 to 5.7 days; p < 0.00001) were longer for hysterectomy. Unsatisfactory outcomes associated with first- and second-generation techniques were comparable [12.2% (123/1006) vs 10.6% (110/1034); OR 1.20, 95% CI 0.88 to 1.62; p = 0.2). Rates of dissatisfaction with Mirena and second-generation EA were similar [18.1% (17/94) vs 22.5% (23/102); OR 0.76, 95% CI 0.38 to 1.53; p = 0.4]. Indirect estimates suggested that hysterectomy was also preferable to second-generation EA (OR 2.32, 95% CI 1.27 to 4.24; p = 0.006) in terms of patient dissatisfaction. The evidence to suggest that hysterectomy is preferable to Mirena was weaker (OR 2.22, 95% CI 0.94 to 5.29; p = 0.07). In women treated by EA or hysterectomy and followed up for a median [interquartile range (IQR)] duration of 6.2 (2.7-10.8) and 11.6 (7.9-14.8) years, respectively, 962/11,299 (8.5%) women originally treated by EA underwent further gynaecological surgery. While the risk of adnexal surgery was similar in both groups [adjusted hazards ratio 0.80 (95% CI 0.56 to 1.15)], women who had undergone ablation were less likely to need pelvic floor repair [adjusted hazards ratio 0.62 (95% CI 0.50 to 0.77)] and tension-free vaginal tape surgery for stress urinary incontinence [adjusted hazards ratio 0.55 (95% CI 0.41 to 0.74)]. Abdominal hysterectomy led to a lower chance of pelvic floor repair surgery [hazards ratio 0.54 (95% CI 0.45 to 0.64)] than vaginal hysterectomy. The incidence of endometrial cancer following EA was 0.02%. Hysterectomy was the most cost-effective treatment. It dominated first-generation EA and, although more expensive, produced more quality-adjusted life-years (QALYs) than second-generation EA and Mirena. The incremental cost-effectiveness ratios for hysterectomy compared with Mirena and hysterectomy compared with second-generation ablation were £1440 per additional QALY and £970 per additional QALY, respectively.

CONCLUSIONS

Despite longer hospital stay and time to resumption of normal activities, more women were satisfied after hysterectomy than after EA. The few data available suggest that Mirena is potentially cheaper and more effective than first-generation ablation techniques, with rates of satisfaction that are similar to second-generation techniques. Owing to a paucity of trials, there is limited evidence to suggest that hysterectomy is preferable to Mirena. The risk of pelvic floor surgery is higher in women treated by hysterectomy than by ablation. Although the most cost-effective strategy, hysterectomy may not be considered an initial option owing to its invasive nature and higher risk of complications. Future research should focus on evaluation of the clinical effectivesness and cost-effectiveness of the best second-generation EA technique under local anaesthetic versus Mirena and types of hysterectomy such as laparoscopic supracervical hysterectomy versus conventional hysterectomy and second-generation EA.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Human gene expression profiles of susceptibility and resistance in tuberculosis

Tuberculosis (TB) still poses a profound burden on global health, owing to significant morbidity and mortality worldwide. Although a fully functional immune system is essential for the control of Mycobacterium tuberculosis infection, the underlying mechanisms and reasons for failure in part of the infected population remain enigmatic. Here, whole-blood microarray gene expression analyses were performed in TB patients and in latently as well as uninfected healthy controls to define biomarkers predictive of susceptibility and resistance. Fc gamma receptor 1B (FCGRIB)was identified as the most differentially expressed gene, and, in combination with four other markers, produced a high degree of accuracy in discriminating TB patients and latently infected donors. We determined differentially expressed genes unique for active disease and identified profiles that correlated with susceptibility and resistance to TB. Elevated expression of innate immune-related genes in active TB and higher expression of particular gene clusters involved in apoptosis and natural killer cell activity in latently infected donors are likely to be the major distinctive factors determining failure or success in controlling M. tuberculosis infection. The gene expression profiles defined in this study provide valuable clues for better understanding of progression from latent infection to active disease and pave the way for defining predictive correlates of protection in TB.

Evidence of a tumour suppressor function for DLEC1 in human breast cancer

DLEC1 (deleted in lung and oesophageal cancer), located on 3p22.3, is a candidate tumour suppressor gene in lung, esophageal, and renal cancer. The aim of this study was determine whether the mRNA expression levels of DLEC1 were consistent with a tumour suppressive function.

MATERIALS AND METHODS

A total of 153 samples were analysed. The levels of transcription of DLEC1 were determined using quantitative PCR and normalised against (CK19). Transcript levels within breast cancer specimens were compared to normal background tissues.

RESULTS

Levels of transcription were lower [corrected] in tumour samples compared to adjacent non cancerous tissue (ANCT) samples but this was not statistically significant (median 0.167 vs. 0.03; p=0.138). DLEC1 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died of breast cancer when compared to those who were disease free for >10 years (p=0.041).

DISCUSSION

These findings are consistent with a possible tumour suppressor function of DLEC1 in breast cancer.

Rapid testing for group B streptococcus during labour: a test accuracy study with evaluation of acceptability and cost-effectiveness

OBJECTIVE

To determine the accuracy, acceptability and cost-effectiveness of polymerase chain reaction (PCR) and optical immunoassay (OIA) rapid tests for maternal group B streptococcal (GBS) colonisation at labour.

DESIGN

A test accuracy study was used to determine the accuracy of rapid tests for GBS colonisation of women in labour. Acceptability of testing to participants was evaluated through a questionnaire administered after delivery, and acceptability to staff through focus groups. A decision-analytic model was constructed to assess the cost-effectiveness of various screening strategies.

SETTING

Two large obstetric units in the UK.

PARTICIPANTS

Women booked for delivery at the participating units other than those electing for a Caesarean delivery.

INTERVENTIONS

Vaginal and rectal swabs were obtained at the onset of labour and the results of vaginal and rectal PCR and OIA (index) tests were compared with the reference standard of enriched culture of combined vaginal and rectal swabs.

MAIN OUTCOME MEASURES

The accuracy of the index tests, the relative accuracies of tests on vaginal and rectal swabs and whether test accuracy varied according to the presence or absence of maternal risk factors.

RESULTS

PCR was significantly more accurate than OIA for the detection of maternal GBS colonisation. Combined vaginal or rectal swab index tests were more sensitive than either test considered individually [combined swab sensitivity for PCR 84% (95% CI 79-88%); vaginal swab 58% (52-64%); rectal swab 71% (66-76%)]. The highest sensitivity for PCR came at the cost of lower specificity [combined specificity 87% (95% CI 85-89%); vaginal swab 92% (90-94%); rectal swab 92% (90-93%)]. The sensitivity and specificity of rapid tests varied according to the presence or absence of maternal risk factors, but not consistently. PCR results were determinants of neonatal GBS colonisation, but maternal risk factors were not. Overall levels of acceptability for rapid testing amongst participants were high. Vaginal swabs were more acceptable than rectal swabs. South Asian women were least likely to have participated in the study and were less happy with the sampling procedure and with the prospect of rapid testing as part of routine care. Midwives were generally positive towards rapid testing but had concerns that it might lead to overtreatment and unnecessary interference in births. Modelling analysis revealed that the most cost-effective strategy was to provide routine intravenous antibiotic prophylaxis (IAP) to all women without screening. Removing this strategy, which is unlikely to be acceptable to most women and midwives, resulted in screening, based on a culture test at 35-37 weeks' gestation, with the provision of antibiotics to all women who screened positive being most cost-effective, assuming that all women in premature labour would receive IAP. The results were sensitive to very small increases in costs and changes in other assumptions. Screening using a rapid test was not cost-effective based on its current sensitivity, specificity and cost.

CONCLUSIONS

Neither rapid test was sufficiently accurate to recommend it for routine use in clinical practice. IAP directed by screening with enriched culture at 35-37 weeks' gestation is likely to be the most acceptable cost-effective strategy, although it is premature to suggest the implementation of this strategy at present.

Gene Transcripts in the Tumor Suppressor Region of Chromosome 3 (3p21)

Background:There is increasing evidence that the short arm of chromosome 3 has a tumour suppressor region that has been associated with permanent growth arrest of tumour cells. We have identified 9 closely related genes in this region (CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, SCAP, SETD2, and TESSP2) located which could be possible candidates for tumour suppressor genes (TSG).Our objective was to determine, using quantitative PCR, whether the mRNA expression levels of these genes were consistent with a tumour suppressive function in human breast cancer.Methods:A total of 153 samples were analysed. The levels of transcription of all 9 genes were determined using quantitative PCR and normalized against (CK19).Transcript levels within breast cancer specimens were compared with non-cancerous breast tissue and analyzed against conventional pathological parameters and clinical outcome over a 10 year follow-up period.Results:Quantification of CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, and SCAP mRNA expression after CK19 normalisation showed no statistically significant difference between malignant and normal breast tissue (p=0.23, 0.46, 0.3, 0.141, 0.8, 0.696, and 0.11 respectively). The mRNA expression of TESSP2 was higher in normal samples compared with malignant lesions (347 vs. 35, p=0.0061) but showed no significant associations with clinical outcome.The levels of SETD2 mRNA were significantly lower in malignant samples (406 vs. 17, p=0.0345) and decreased with increasing tumour stage. SETD2 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died from breast cancer when compared to those who were disease free for &gt; 10 years (p=0.041).Conclusion:These findings are consistent with a possible tumour suppressor function of SETD2 in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6139.