Accuracy of artificial intelligence-assisted growth prediction in skeletal Class I preadolescent patients using serial lateral cephalograms for a 2-year growth interval

OBJECTIVE

To investigate the accuracy of artificial intelligence-assisted growth prediction using a convolutional neural network (CNN) algorithm and longitudinal lateral cephalograms (Lat-cephs).

MATERIALS AND METHODS

A total of 198 Japanese preadolescent children, who had skeletal Class I malocclusion and whose Lat-cephs were available at age 8 years (T0) and 10 years (T1), were allocated into the training, validation, and test phases (n = 161, n = 17, n = 20). Orthodontists and the CNN model identified 28 hard-tissue landmarks (HTL) and 19 soft-tissue landmarks (STL). The mean prediction error values were defined as 'excellent,' 'very good,' 'good,' 'acceptable,' and 'unsatisfactory' (criteria: 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively). The degree of accurate prediction percentage (APP) was defined as 'very high,' 'high,' 'medium,' and 'low' (criteria: 90%, 70%, and 50%, respectively) according to the percentage of subjects that showed the error range within 1.5 mm.

RESULTS

All HTLs showed acceptable-to-excellent mean PE values, while the STLs Pog', Gn', and Me' showed unsatisfactory values, and the rest showed good-to-acceptable values. Regarding the degree of APP, HTLs Ba, ramus posterior, Pm, Pog, B-point, Me, and mandibular first molar root apex exhibited low APPs. The STLs labrale superius, lower embrasure, lower lip, point of lower profile, B', Pog,' Gn' and Me' also exhibited low APPs. The remainder of HTLs and STLs showed medium-to-very high APPs.

CONCLUSION

Despite the possibility of using the CNN model to predict growth, further studies are needed to improve the prediction accuracy in HTLs and STLs of the chin area.

Severe asthma in children: Description of a large multidisciplinary clinical cohort

BACKGROUND

Children with severe asthma have substantial morbidity and healthcare utilization. Pediatric severe asthma is a heterogeneous disease, and a multidisciplinary approach can improve the diagnosis and management of these children.

METHODS

We reviewed the electronic health records for patients seen in the Severe Asthma Clinic (SAC) at UPMC Children's Hospital of Pittsburgh between August 2012 and October 2019.

RESULTS

Of the 110 patients in whom we extracted data, 46% were female, 48% were Black/African American, and 41% had ≥1 admission to the pediatric intensive care unit (PICU) for asthma. Compared to patients without a PICU admission, those with ≥1 PICU admission were more likely to be non-White (64.4% vs. 41.5%, p = 0.031) and more atopic (eosinophil count geometric mean = 673 vs. 319 cells/mm3 , p = 0.002; total IgE geometric mean = 754 vs. 303 KU/L, p = 0.003), and to have lower pre-bronchodilator FEV1 (58.6% [±18.1%] vs. 69.9% [±18.7%], p = 0.002) and elevated FeNO (60% vs. 22%, p = 0.02). In this cohort, 84% of patients were prescribed high-dose ICS/LABA and 36% were on biologics. Following enrollment in the SAC, severe exacerbations decreased from 3.2/year to 2.2/year (p < 0.0001); compared to the year before joining the SAC, in the following year the group had 106 fewer severe exacerbations.

CONCLUSIONS

This large cohort of children with severe asthma had a high level of morbidity and healthcare utilization. Patients with a history of PICU admissions for asthma were more likely to be nonwhite and highly atopic, and to have lower lung function. Our data support a positive impact of a multidisciplinary clinic on patients with severe childhood asthma.

Quantitative CT Characteristics of Cluster Phenotypes in the Severe Asthma Research Program Cohorts

Background Clustering key clinical characteristics of participants in the Severe Asthma Research Program (SARP), a large, multicenter prospective observational study of patients with asthma and healthy controls, has led to the identification of novel asthma phenotypes. Purpose To determine whether quantitative CT (qCT) could help distinguish between clinical asthma phenotypes. Materials and Methods A retrospective cross-sectional analysis was conducted with the use of qCT images (maximal bronchodilation at total lung capacity [TLC], or inspiration, and functional residual capacity [FRC], or expiration) from the cluster phenotypes of SARP participants (cluster 1: minimal disease; cluster 2: mild, reversible; cluster 3: obese asthma; cluster 4: severe, reversible; cluster 5: severe, irreversible) enrolled between September 2001 and December 2015. Airway morphometry was performed along standard paths (RB1, RB4, RB10, LB1, and LB10). Corresponding voxels from TLC and FRC images were mapped with use of deformable image registration to characterize disease probability maps (DPMs) of functional small airway disease (fSAD), voxel-level volume changes (Jacobian), and isotropy (anisotropic deformation index [ADI]). The association between cluster assignment and qCT measures was evaluated using linear mixed models. Results A total of 455 participants were evaluated with cluster assignments and CT (mean age ± SD, 42.1 years ± 14.7; 270 women). Airway morphometry had limited ability to help discern between clusters. DPM fSAD was highest in cluster 5 (cluster 1 in SARP III: 19.0% ± 20.6; cluster 2: 18.9% ± 13.3; cluster 3: 24.9% ± 13.1; cluster 4: 24.1% ± 8.4; cluster 5: 38.8% ± 14.4; P < .001). Lower whole-lung Jacobian and ADI values were associated with greater cluster severity. Compared to cluster 1, cluster 5 lung expansion was 31% smaller (Jacobian in SARP III cohort: 2.31 ± 0.6 vs 1.61 ± 0.3, respectively, P < .001) and 34% more isotropic (ADI in SARP III cohort: 0.40 ± 0.1 vs 0.61 ± 0.2, P < .001). Within-lung Jacobian and ADI SDs decreased as severity worsened (Jacobian SD in SARP III cohort: 0.90 ± 0.4 for cluster 1; 0.79 ± 0.3 for cluster 2; 0.62 ± 0.2 for cluster 3; 0.63 ± 0.2 for cluster 4; and 0.41 ± 0.2 for cluster 5; P < .001). Conclusion Quantitative CT assessments of the degree and intraindividual regional variability of lung expansion distinguished between well-established clinical phenotypes among participants with asthma from the Severe Asthma Research Program study. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Verschakelen in this issue.

Severe asthma during childhood and adolescence: A longitudinal study

BACKGROUND

Morbidity and mortality associated with childhood asthma are driven disproportionately by children with severe asthma. However, it is not known from longitudinal studies whether children outgrow severe asthma.

OBJECTIVE

We sought to study prospectively whether well-characterized children with severe asthma outgrow their asthma during adolescence.

METHODS

Children with asthma were assessed at baseline with detailed questionnaires, allergy tests, and lung function tests and were reassessed annually for 3 years. The population was enriched for children with severe asthma, as assessed by the American Thoracic Society/European Respiratory Society guidelines, and subject classification was reassessed annually.

RESULTS

At baseline, 111 (59%) children had severe asthma. Year to year, there was a decrease in the proportion meeting the criteria for severe asthma. After 3 years, only 30% of subjects met the criteria for severe asthma (P < .001 compared with enrollment). Subjects experienced improvements in most indices of severity, including symptom scores, exacerbations, and controller medication requirements, but not lung function. Surprisingly, boys and girls were equally likely to has resolved asthma (33% vs 29%). The odds ratio in favor of resolution of severe asthma was 2.75 (95% CI, 1.02-7.43) for those with a peripheral eosinophil count of greater than 436 cells/μL.

CONCLUSIONS

In longitudinal analysis of this well-characterized cohort, half of the children with severe asthma no longer had severe asthma after 3 years; there was a stepwise decrease in the proportion meeting severe asthma criteria. Surprisingly, asthma severity decreased equally in male and female subjects. Peripheral eosinophilia predicted resolution. These data will be important for planning clinical trials in this population.

Racial disparities in asthma-related health care use in the National Heart, Lung, and Blood Institute's Severe Asthma Research Program

BACKGROUND

Despite advances in asthma care, disparities persist. Black patients are disproportionally affected by asthma and also have poorer outcomes compared with white patients.

OBJECTIVE

We sought to determine associations between black and white patients and asthma-related health care use, accounting for complex relationships.

METHODS

This study was completed as part of the National Heart, Lung, and Blood Institute's Severe Asthma Research Program, a prospective observational cohort. Between November 2012 and February 2015, it enrolled 579 participants 6 years and older with 1 year of observation time and complete data. Inverse probability of treatment weighting was used to balance racial groups with respect to community and family socioeconomic variables and environmental exposure variables. The primary outcome was emergency department (ED) use for asthma. Secondary outcomes included inhaled corticosteroid use, outpatient physician's office visits for asthma, and asthma-related hospitalization.

RESULTS

Black patients had greater odds of ED use over 1 year (odds ratio, 2.19; 95% CI, 1.43-3.35) but also differed in the majority (>50%) of baseline variables measured. After statistical balancing of the racial groups, the difference between black and white patients with respect to ED use no longer reached the level of significance. Instead, in secondary analyses black patients were less likely to see an outpatient physician for asthma management (adjusted odds ratio, 0.57; 95% CI, 0.38-0.85).

CONCLUSIONS

The disparity in ED use was eliminated after consideration of multiple variables. Social and environmental policies and interventions tailored to black populations with a high burden of asthma are critical to reduction (or elimination) of these disparities.

Hypersensitivity Pneumonitis and Acute Respiratory Distress Syndrome From E-Cigarette Use

Electronic cigarette (e-cigarette) use, or "vaping," is gaining widespread popularity as an alternative to conventional cigarettes among adolescents. Little is known of the health risks of e-cigarette use, especially in children and adolescents. We present a Case Report of a previously healthy 18-year-old woman who presented with dyspnea, cough, and pleuritic chest pain after e-cigarette use. She developed respiratory failure with hypoxia and was intubated, and ultimately met diagnostic criteria for acute respiratory distress syndrome. Chest tubes were placed to drain worsening pleural effusions. Computed tomography of the chest revealed dependent opacities in both lung bases, superimposed smooth interlobular septal thickening, and pleural effusions. Bronchoalveolar lavage revealed cellular debris and reactive mononuclear cells, and cell counts were remarkable for elevated mononuclear cells and eosinophilia. After the results of a workup for an infectious etiology came back negative, the patient was diagnosed with hypersensitivity pneumonitis and intravenous methylprednisolone therapy was initiated. After this the patient rapidly improved, was weaned off vasopressor support, and was extubated. This is the first reported case of hypersensitivity pneumonitis and acute respiratory distress syndrome as a risk of e-cigarette use in an adolescent, and it should prompt pediatricians to discuss the potential harms of vaping with their patients. Hypersensitivity pneumonitis, lipid pneumonia, and eosinophilic pneumonia should be included in the differential diagnosis of patients who exhibit respiratory symptoms after the use of an e-cigarette.

Engaging stakeholders in research to address water-energy-food (WEF) nexus challenges

The water-energy-food (WEF) nexus has become a popular, and potentially powerful, frame through which to analyse interactions and interdependencies between these three systems. Though the case for transdisciplinary research in this space has been made, the extent of stakeholder engagement in research remains limited with stakeholders most commonly incorporated in research as end-users. Yet, stakeholders interact with nexus issues in a variety of ways, consequently there is much that collaboration might offer to develop nexus research and enhance its application. This paper outlines four aspects of nexus research and considers the value and potential challenges for transdisciplinary research in each. We focus on assessing and visualising nexus systems; understanding governance and capacity building; the importance of scale; and the implications of future change. The paper then proceeds to describe a novel mixed-method study that deeply integrates stakeholder knowledge with insights from multiple disciplines. We argue that mixed-method research designs-in this case orientated around a number of cases studies-are best suited to understanding and addressing real-world nexus challenges, with their inevitable complex, non-linear system characteristics. Moreover, integrating multiple forms of knowledge in the manner described in this paper enables research to assess the potential for, and processes of, scaling-up innovations in the nexus space, to contribute insights to policy and decision making.

Towards Personal Exposures: How Technology Is Changing Air Pollution and Health Research

PURPOSE OF REVIEW

We present a review of emerging technologies and how these can transform personal air pollution exposure assessment and subsequent health research.

RECENT FINDINGS

Estimating personal air pollution exposures is currently split broadly into methods for modeling exposures for large populations versus measuring exposures for small populations. Air pollution sensors, smartphones, and air pollution models capitalizing on big/new data sources offer tremendous opportunity for unifying these approaches and improving long-term personal exposure prediction at scales needed for population-based research. A multi-disciplinary approach is needed to combine these technologies to not only estimate personal exposures for epidemiological research but also determine drivers of these exposures and new prevention opportunities. While available technologies can revolutionize air pollution exposure research, ethical, privacy, logistical, and data science challenges must be met before widespread implementations occur. Available technologies and related advances in data science can improve long-term personal air pollution exposure estimates at scales needed for population-based research. This will advance our ability to evaluate the impacts of air pollution on human health and develop effective prevention strategies.

Exercise in the community for people with minimal gait impairment due to MS: an assessor-blind randomized controlled trial

Background:

While there is an increasing body of evidence supporting the efficacy of exercise in people with multiple sclerosis (MS), additional information on the effectiveness of combining aerobic and resistance training, and yoga is required.

Objectives:

This study evaluated the effectiveness of community exercise interventions for people with MS having minimal gait impairment.

Methods:

A multi-centred, block-randomised, assessor-blinded, controlled trial was conducted. Participants were randomised in groups of eight to physiotherapist (PT)-led exercise ( n = 80), yoga ( n = 77), fitness instructor (FI)-led exercise ( n = 86) and they took part in weekly community-based group exercise sessions. Those in the control group were asked not to change of their exercise habits ( n = 71). The primary outcome was the Multiple Sclerosis Impact Scale (MSIS) 29v2 physical component, measured before and after the 10-week intervention. Secondary outcomes were the MSIS 29v2 psychological component, the Modified Fatigue Impact Scale (MFIS) and the 6-Minute Walk Test (6MWT).

Results:

The group x time interaction approached significance for the MSIS-29v2 physical component ( f = 2.48, p = 0.061) and MFIS total ( f = 2.50, p = 0.06), and it was significant for the MFIS physical subscale ( f = 4.23, p = 0.006). All three exercise interventions led to a statistically significant improvement on the MSIS-29 psychological component and both the MFIS total and physical subscales, which were greater than the control ( p < 0.05). Only the PT-led and FI-led interventions significantly improved the MSIS-29 physical and 6MWT to levels greater than the control ( p < 0.05).

Conclusions:

This study provides evidence for the positive effect of exercise on the physical impact of MS and fatigue. The group nature of the classes may have contributed to the positive effects seen on the psychological impact of MS.

Asthmatic granulomatosis: a novel disease with asthmatic and granulomatous features

RATIONALE

Severe asthma represents 5-10% of all asthma, yet remains problematic and poorly understood. Although it is increasingly recognized as consisting of numerous heterogenous phenotypes, their immunopathology, particularly in the distal airways and interstitium, remains poorly described.

OBJECTIVES

To identify the pathobiology of atypical difficult asthma.

METHODS

We report 10 from a total of 19 patients (17 women and 2 men) meeting asthma and severe asthma definitions, requiring daily systemic corticosteroid (CS) use, with inconsistent abnormalities on chest computed tomography scans, who underwent video-assisted thoracoscopic biopsies for further diagnosis and management.

MEASUREMENTS AND MAIN RESULTS

The pathology of 10 of the 19 cases revealed small airway changes consistent with asthma (eosinophilia, goblet cell hyperplasia), but with the unexpected finding of interstitial nonnecrotizing granulomas. These patients had no evidence for hypersensitivity pneumonitis, but 70% of cases had a personal or family history of autoimmune-like disease. The 10 cases were treated with azathioprine, mycophenolic acid, methotrexate, or infliximab. Nine of 10 showed decreased CS requirements and improved or maintained FEV(1) despite lower CS doses. Of the remaining nine patients, six manifested asthmatic small airway disease, alone or in combination with alveolar septal mononuclear cells, but no granulomas, whereas three manifested other pathologic findings (aspiration, pneumonia, or thromboemboli).

CONCLUSIONS

These data suggest that a subset of severe "asthma" manifests a granulomatous pathology, which we term "asthmatic granulomatosis." Although identification of this disease currently requires a thorascopic biopsy, alternative approaches to therapy lead to improvement in outcomes.

Systemic FasL neutralization increases eosinophilic inflammation in a mouse model of asthma

BACKGROUND

Eosinophils and lymphocytes are pathogenically important in allergic inflammation and sensitive to Fas-mediated apoptosis. Fas ligand (FasL) activity therefore should play a role in regulating the allergic immune response. We aimed to characterize the role of FasL expression in airway eosinophilia in Aspergillus fumigatus (Af)-induced sensitization and to determine whether FasL neutralization alters the inflammatory response.

METHODS

Sensitized Balb/c mice were killed before (day 0) and 1, 7 and 10 days after a single intranasal challenge with Af. Animals received either neutralizing antibody to FasL (clone MFL4) or irrelevant hamster IgG via intraperitoneal injection on days -1 and 5. FasL expression, BAL and tissue inflammatory cell and cytokine profile, and apoptosis were assessed.

RESULTS

Postchallenge FasL gene expression in BAL cells and TUNEL positivity in the airways coincided with the height of inflammatory cell influx on day 1, while soluble FasL protein was released on day 7, preceding resolution of the inflammatory changes. Although eosinophil numbers showed a negative correlation with soluble FasL levels in the airways, MBP(+) eosinophils remained TUNEL negative in the submucosal tissue, throughout the 10-day period after Af challenge. Systemic FasL neutralization significantly enhanced BAL and tissue eosinophil counts. This effect was associated with increased activation of T cells and release of IL-5, IL-9, and GM-CSF in the BAL fluid of mice, indicating an involvement of pro-eosinophilic survival pathways.

CONCLUSIONS

FasL activity may play an active role in resolving eosinophilic inflammation through regulating T cells and pro-eosinophilic cytokine release during the allergic airway response.

Development of training syllabi for radiation protection and quality assurance of dual-energy X-ray absorptiometry (DXA) systems

The use of dual-energy X-ray absorptiometry (DXA) scanners for measuring bone mineral density (BMD) is on the increase. A single DXA scan is a relatively low-dose diagnostic X-ray examination; however, radiation protection (RP) issues should not be trivialised. One objective of the EU 6th Framework SENTINEL co-ordination action was to develop training syllabi in RP and quality assurance (QA) for BMD, and this study presents the results. An EU-wide survey was carried out which confirmed that there was a need for an accredited DXA RP training course in many EU states. There is also limited published guidance on acceptance testing/QA for DXA. Two training syllabi were developed: one on RP and one on QA of DXA systems. A training course was delivered in Ireland in 2006 by the Medical Physics & Bioengineering Department of St James's Hospital, Dublin. Following the training course, a PC-based training CD was developed and will be made available. A harmonised approach to training will promote consistent approaches to radiation safety across the EU.

QA/acceptance testing of DEXA X-ray systems used in bone mineral densitometry

New developments in dual energy X-ray absorptiometry (DEXA) imaging technology [fan beam and cone beam (CB)] result in higher exposure levels, shorter scan times, increased patient throughput and increased shielding requirements. This study presents the results of a European survey detailing the number and location of DEXA systems in SENTINEL partner states and the QA (quality assurance) currently performed by physicists and operators in these centres. The results of a DEXA equipment survey based on an in-house developed QA protocol are presented. Measurements show that the total effective dose to the patient from a spine and dual femur DEXA examination on the latest generation DEXA systems is comparable with a few microSv at most. Scatter measurements showed that the use of a mobile lead screen for staff protection was necessary for fan and CB systems. Scattered dose from newer generation systems may also exceed the exposure limits for the general public so structural shielding may also be required. Considerable variation in the magnitude and annual repeatability of half value layer was noted between different models of DEXA scanners. A comparative study of BMD (bone mineral density) accuracy using the European Spine Phantom highlighted a deviation of up to 7% in BMD values between scanners of different manufacturers.

Acceptance testing and routine quality control in general radiography: mobile units and film/screen fixed systems

This study presents the findings from acceptance testing and routine quality control (QC) of general radiographic X-ray equipment in Ireland during 2006 and early 2007, including mobile X-ray units and film/screen fixed systems. Acceptance testing and routine QC of the diagnostic X-ray imaging equipment are requirements of European and Irish legislation. One hundred general radiographic X-ray systems were tested within Ireland, 73% of them failed to meet the required QC guidelines, whereby one or more faults were identified. The majority of these failures were minor ones, requiring attention by the suppliers at the next routine service. Significant faults were only identified in seven systems. The suppliers were requested to investigate these issues as soon as possible and take the necessary corrective action. A review of the QC results highlights the need to perform comprehensive acceptance and routine testing of the systems.

Quality assurance of computed and digital radiography systems

Computed radiography (CR) and digital radiography (DR) are replacing traditional film screen radiography as hospitals move towards digital imaging and picture archiving and communication systems (PACS). Both IPEM and KCARE have recently published quality assurance and acceptance testing guidelines for DR. In this paper, the performance of a range of CR and DR systems is compared. Six different manufacturers are included. Particular attention is paid to the performance of the systems under automatic exposure control (AEC). The patient is simulated using a range of thicknesses of tissue equivalent material. Image quality assessment was based on detector assessment protocols and includes pixel value measures as well as subjective assessment using Leeds Test Objects. The protocols for detector assessment cover a broad range of tests and in general detectors (whether DR or CR) performed satisfactorily. The chief limitation in performing these tests was that not all systems provided ready access to pixel values. Subjective tests include the use of the Leeds TO20. As part of this work, suggested reference values are provided to calculate the TO20 image quality factor. One consequence of moving from film screen to digital technologies is that the dynamic range of digital detectors is much wider, and increased exposures are no longer evident from changes in image quality. As such, AEC is a key parameter for CR and DR. Dose was measured using a standard phantom as a basic means of comparing systems. In order to assess the AEC performance, exit doses were also measured while varying phantom thickness. Signal-to-noise ratios (SNRs) were calculated on a number of systems where pixel values were available. SNR was affected by the selection of acquisition protocol. Comparisons between different technologies and collation of data will help refine acceptance thresholds and contribute to optimising dose and image quality.

Patient dose in interventional radiology: a European survey

Patient doses for a few common fluoroscopy-guided procedures in interventional radiology (IR) (excluding cardiology) were collected from a few radiological departments in 13 European countries. The major aim was to evaluate patient doses for the basis of the reference levels. In total, data for 20 procedures for about 1300 patients were collected. There were many-fold variations in the number of IR equipment and procedures per population, in the entrance dose rates, and in the patient dose data (total dose area product or DAP, fluoroscopy time and number of frames). There was no clear correlation between the total DAP and entrance dose rate, or between the total DAP and fluoroscopy time, indicating that a number of parameters affect the differences. Because of the limited number of patients, preliminary reference levels were proposed only for a few procedures. There is a need to improve the optimisation of IR procedures and their definitions and grouping, in order to account for their different complexities.

Acceptance testing and QA of interventional cardiology systems

Interventional cardiology (IC) is a rapidly growing field of medical specialisation. Such procedures are complex and may subject patients and operators to higher levels of risk than those encountered in general radiology. Acceptance testing and quality assurance (QA) of radiological equipment, including IC equipment, is a requirement of the EU Medical Exposures Directive (MED) (97/43/EURATOM). In addition, the MED identifies interventional radiology as an area of special concern. This study presents the results of a survey of 17 IC systems (including several flat panel detector systems) in Irish hospitals. The results of the survey indicate large differences in patient doses between manufacturers for equivalent levels of measured image quality. In addition, all systems were found to have failed one or more acceptance tests, with 60% of systems demonstrating significant problems at acceptance testing. The results of the survey demonstrate the importance of acceptance testing and QA in IC. The results also provide baseline data, which may be used in the development of future QA guidelines.

Acceptance testing of fluoroscopy systems used for interventional purposes

This study presents the results of acceptance testing on 18 interventional fluoroscopy systems in Ireland. Acceptance testing and routine quality assurance (QA) of X-ray systems are the requirements of the EU Medical Exposures Directive (MED) and these requirements were subsequently implemented into Irish legislation. The MED states that special consideration should be given to the QA and dose assessment of high dose procedures such as interventional fluoroscopy. Owing to the advances in fluoroscopy technology, it has been found that comprehensive testing of interventional systems proves challenging in a busy hospital environment. A number of recurrent problems have been identified and are presented.

MDR1/P-glycoprotein and MRP-1 drug efflux pumps in pancreatic carcinoma

BACKGROUND

Pancreatic cancer is one of the most challenging solid organ malignancies. This is due to its aggressiveness, frequent late presentation as advanced disease and chemoresistance. A better understanding of the molecular basis of its drug resistance is needed.

MATERIALS AND METHODS

In this study, the first of its kind, the expression of both MDR1 P-gp and MRP-1 protein in pancreatic tumour specimens was examined by immunohistochemistry. Expression of these drug efflux pumps was examined using semi-quantitative immunohistochemistry according to the percentage of cells within the tumour, demonstrating another staining intencity.

RESULTS

Overall, 93.3% of pancreatic carcinomas expressed MDR1 P-gp, approximately 31% co-expressed MRP-1 with MDR1 P-gp, while 6.7% expressed neither of these proteins.

CONCLUSION

Our results show that drug efflux pumps, in particular that of MDR1 P-gp, are frequently expressed in pancreatic cancer. While a causative role for these efflux pumps in pancreatic cancer chemoresistance cannot necessarily be concluded, the information presented here should be considered when selecting chemotherapy/drug efflux pump inhibitors for future therapies.

MDR1/P-glycoprotein and MRP-1 mRNA and protein expression in non-small cell lung cancer

BACKGROUND

Multiple drug resistance (MDR), both inherent and acquired, is a serious problem in non-small cell lung carcinomas (NSCLC). The purpose of this study was to investigate the prevalence of expression of genes encoding drug efflux pumps, MDR1 and MRP-1, at both the mRNA and protein levels, in this type of cancer.

MATERIALS AND METHODS

Tumour specimens (38 cases) were analysed using immunohistochemistry and, where possible (30 cases), also using reverse-transcriptase polymerase chain reaction.

RESULTS

The results from this analysis indicated that either, or both, drug efflux pumps were frequently expressed in NSCLC. Expression of mrp1 was found to be predominant over mdr1 at the mRNA level, while MDR1 P-gp was more frequently detected than MRP-1 protein. In some cases, proteins encoding pumps were detected without corresponding mRNAs--possibly due to differing sensitivities of the analysis techniques.

CONCLUSION

Future studies of mdr1 and mrp1 using increased-sensitivity qPCR techniques, in parallel with protein analysis, in larger cohorts of cases may help to elucidate the role of drug efflux pumps in NSCLC multiple drug resistance.

A phase I clinical and pharmacokinetic study of the multi-drug resistance protein-1 (MRP-1) inhibitor sulindac, in combination with epirubicin in patients with advanced cancer

PURPOSE

Multi-drug resistance mediated by ATP-binding cassette trans-membrane protein pumps is an important cause of cancer treatment failure. Sulindac has been shown to be a competitive substrate for the clinically important resistance protein, multi-drug resistance protein-1 (MRP-1), and thus might enhance the anti-cancer activity of substrate chemotherapeutic agents, e.g. anthracyclines.

METHODS

We conducted a dose-escalating, single arm, prospective, open label, non-randomised phase I trial of epirubicin (75 mg/m(2)) in combination with escalating oral doses of sulindac (0-800 mg) in patients with advanced cancer to identify an appropriate dose of sulindac to use in future resistance studies. Anthracycline and sulindac pharmacokinetics were studied in cycles 1 and 3.

RESULTS

Seventeen patients (8 breast, 3 lung, 2 bowel, 1 melanoma, 1 renal, 1 ovarian and 1 of unknown primary origin, 16/17 having had prior chemotherapy) were enrolled. Eight patients received a full six cycles of treatment; 14 patients received three or more cycles. Dose-limiting toxicity was observed in two patients at 800 mg sulindac (1 renal impairment, 1 fatal haemoptysis in a patient with advanced lung cancer), and sulindac 600 mg was deemed to be the maximum tolerated dose. Sulindac had no effect on epirubicin pharmacokinetics. Among 15 patients with evaluable tumour, two partial responses were seen (malignant melanoma and breast cancer). Four others had prolonged stable disease.

CONCLUSION

Epirubicin 75 mg/m(2) and sulindac 600 mg are the recommended doses for phase II studies for these agents in combination.

Deterministic weak localization in periodic structures

In some perfect periodic structures classical motion exhibits deterministic diffusion. For such systems we present the weak localization theory. As a manifestation for the velocity autocorrelation function a universal power law decay is predicted to appear at four Ehrenfest times. This deterministic weak localization is robust against weak quenched disorders, which may be confirmed by coherent backscattering measurements of periodic photonic crystals.

Exposure variations under error conditions in automatic exposure controlled film-screen projection radiography

Improper automatic exposure control (AEC) termination may result in high overexposures on some radiographic systems. Under AEC, X-ray factors are adjusted automatically to compensate for differences in patient thickness and density. In radiography, AEC is implemented using ionization chambers placed in the film bucky. In this study we deliberately chose incorrect set-up conditions and assessed the response of the AEC system. Two types of incorrect set-up were studied: (1) incorrect selection of bucky radiation detector and (2) simulated misalignment between the X-ray field and light field. The systems tested varied in age from 1 year to in excess of 10 years. In the first test, overexposures of 90 mGy were recorded. Two systems did not meet EC guidelines for improper AEC termination. The second test, misalignment of the X-ray field, was observed to affect the exposure delivered by approximately +/-22%. The maximum dose increase observed, with a chest phantom in the beam, was 165 microGy. Misalignments also resulted in reduced exposures, which may impact on image quality.

Weak dynamical localization in periodically kicked cold atomic gases

Quantum kicked rotor was recently realized in experiments with cold atomic gases and standing optical waves. As predicted, it exhibits dynamical localization in the momentum space. Here we consider the weak-localization regime concentrating on the Ehrenfest time scale. The latter accounts for the spread time of a minimal wave packet and is proportional to the logarithm of the Planck constant. We show that the onset of the dynamical localization is essentially delayed by four Ehrenfest times, and give quantitative predictions suitable for an experimental verification.

Fibre mapping – a case study

Fibre mapping, more commonly known as one-to-one taping, was developed in Germany approximately twenty years ago. The technique facilitates the distribution of fibres on a surface to be recorded. The impact of this technique on the investigation of serious crime has been reported in the European Fibre Group on several occasions. This paper represents a case study of the application of the technique. It is believed to be the first time that this technique has been successfully applied in the United Kingdom.

Expression and prognostic relevance of Mcl-1 in breast cancer

BACKGROUND

Bcl-2, an anti-apoptotic protein, is frequently associated with favourable prognosis in breast cancer. The potential role of mcl-1, another bcl-2 family member, in breast cancer has not yet been defined.

PATIENTS AND METHODS

This study examined the expression of mcl-1 and bcl-2 in 170 cases of invasive primary breast carcinoma, using reverse-transcriptase polymerase chain reaction and immunohistochemical analyses.

RESULTS

Expression of bcl-2 mRNA and protein were found to be favourably associated with outcome for patients, supporting a prognostic role for bcl-2 in breast cancer, whereas mcl-1 expression, at the mRNA or protein level, did not correlate with tumour size, grade, lymph node or ER status, age of patient at diagnosis, or disease outcome.

CONCLUSION

As these analyses of mcl-1 expression may have co-detected mcl-1(S/deltaTM) (a more recently identified, shorter variant, that may be pro-apoptotic) with the anti-apoptotic wild-type of mcl-1, it is possible that future studies may indicate some significant clinical correlations if the isoforms can be independently investigated.

Lymphoproliferative disease in antibody deficiency: a multi-centre study

We have undertaken a retrospective study of antibody deficient patients, with and without lymphoma, and assessed the ability of specific polymerase chain reaction (PCR) primers to determine if the detection of clonal lymphocyte populations correlates with clinical and immunohistochemical diagnosis of lymphoma. We identified 158 cases with antibody deficiency presenting during the past 20 years. Paraffin-embedded biopsy specimens or slides were available for analysis in a cohort of 34 patients. Of these patients, 29 had common variable immunodeficiency, one X-linked agammaglobulinaemia, one X-linked immunoglobulin deficiency of uncertain cause and three isolated IgG subclass deficiency. We have confirmed that lymphoma in antibody deficiency is predominantly B cell in origin. Clonal lymphocyte populations were demonstrated in biopsies irrespective of histology (16/19 with lymphoma and 11/15 without). Isolated evidence of clonality in biopsy material is therefore an insufficient diagnostic criterion to determine malignancy. Furthermore, our data suggest that clonal expansions are rarely the result of Epstein-Barr virus-driven disease.

A new monoclonal antibody, P2A8(6), that specifically recognizes a novel epitope on the multidrug resistance-associated protein 1 (MRP1), but not on MRP2 nor MRP3

Multidrug resistance (MDR) is a major problem in the chemotherapeutic treatment of cancer. Overexpression of the multidrug resistance-associated protein 1 (MRP1), is associated with MDR in certain tumors. A number of MRP1-specific MAbs, which facilitate both clinical and experimental investigations of this protein, are available. To add to this panel of existing antibodies, we have now generated an additional MRP1-specific monoclonal antibody (MAb), P2A8(6), which detects a unique heat stable epitope on the MRP1 molecule. Female Wistar rats were immunized via footpad injections with a combination of two short synthetic peptides corresponding to amino acids 235-246 (peptide A) and 246-260 (peptide B) of the MRP1 protein. Immune reactive B cells were then isolated from the popliteal lymph nodes for fusion with SP2/O-Ag14 myeloma cells. Resultant hybridoma supernatants were screened for MRP1-specific antibody production. Antibody P2A8(6) was characterized by Western blotting and immunocytochemistry on paired multidrug resistant (MRP1 overexpressing) and sensitive parental cell lines. The antibody detects a protein of 190 kDa in MRP1-expressing cell lines but not in MRP2- or MRP3-transfected cell lines. P2A8(6) stains drug-selected and MRP1-transfected cell lines homogeneously by immunocytochemistry and recognizes MRP1 by immunohistochemistry on formalin-fixed paraffin wax-embedded tissue sections. Peptide inhibition studies confirm that P2A8(6) reacts with peptide B (amino acids 246-260), therefore recognizing a different epitope from that of all currently available MRP1 MAbs. This new MAb, chosen for its specificity to the MRP1 protein, may be a useful addition to the currently available range of MRP1-specific MAbs.

Shot noise in chaotic systems: "classical" to quantum crossover

This paper is devoted to study of the classical-to-quantum crossover of the shot noise in chaotic systems. This crossover is determined by the ratio of the particle dwell time in the system, tau(d), to the characteristic time for diffraction t(E) approximately lambda(-1)|lnh, where lambda is the Lyapunov exponent. The shot noise vanishes when t(E)>>tau(d), while it reaches a universal value in the opposite limit. Thus, the Lyapunov exponent of chaotic mesoscopic systems may be found by shot noise measurements.

p38 MAPK and NF-kappa B collaborate to induce interleukin-6 gene expression and release. Evidence for a cytoprotective autocrine signaling pathway in a cardiac myocyte model system

In cardiac myocytes, the stimulation of p38 MAPK by the MAPKK, MKK6, activates the transcription factor, NF-kappaB, and protects cells from apoptosis. In the present study in primary neonatal rat cardiac myocytes, constitutively active MKK6, MKK6(Glu), bound to IkappaB kinase (IKK)-beta and stimulated its abilities to phosphorylate IkappaB and to activate NF-kappaB. MKK6(Glu) induced NF-kappaB-dependent interleukin (IL)-6 transcription and IL-6 release in a p38-dependent manner. IL-6 protected myocardial cells against apoptosis. Like IL-6, TNF-alpha, which activates both NF-kappaB and p38, also induced p38-dependent IL-6 expression and release and protected myocytes from apoptotis. While TNF-alpha was relatively ineffective, IL-6 activated myocardial cell STAT3 by about 8-fold, indicating a probable role for this transcription factor in IL-6-mediated protection from apoptosis. TNF-alpha-mediated IL-6 induction was inhibited by a kinase-inactive form of the MAPKKK, TGF-beta activated protein kinase (Tak1), which is known to activate p38 and NF-kappaB in other cell types. Thus, by stimulating both p38 and NF-kappaB, Tak1-activating cytokines, like TNF-alpha, can induce IL-6 expression and release. Moreover, the myocyte-derived IL-6 may then function in an autocrine and/or paracrine fashion to augment myocardial cell survival during stresses that activate p38.

Appropriateness of a Resuscitation Council (UK) advanced life support course for primary care dentists

OBJECTIVES

To investigate whether a standard Resuscitation Council (UK) ALS course is appropriate for primary care dentists or whether a course should be specifically designed for dentists.

DESIGN

Opinions canvassed by pre-course expectation and post-course evaluation questionnaires.

SUBJECTS

23 West Pennine primary care dentists providing a general anaesthetic or conscious sedation service who attended an ALS course.

RESULTS

Knowledge and skills were rated on a 5-point scale from 1 (not important at all) to 5 (extremely important). Basic airway management (mean = 5) and anaphylaxis (mean = 4.9) scored the highest on the 'expectation' questionnaire. Rhythm recognition (P < 0.001), defibrillation (P = 0.007) and arrest algorithms (P = 0.047) were rated as significantly more important after the course than before. Knowledge about rhythm disorder management, cardiac pacing, post-resuscitation care, blood gas interpretation and bereavement were not considered to be so important either before or after the course.

CONCLUSIONS

Despite rating some aspects as unimportant, all dentists stated that this course had been appropriate. They did not want a specially designed ALS course for dentistry. Taking exactly the same recognised course and assessments as other healthcare professionals and gaining the same certification was felt to be important to this group of dentists.

Low-dose twice-daily fractionated X-irradiation of ovarian tumor cells in vitro generates drug-resistant cells overexpressing two multidrug resistance-associated proteins, P-glycoprotein and MRP1

Failure of chemotherapy is frequently observed in patients previously treated with radiotherapy. To establish a cellular model for examining this resistance phenotype a series of mammalian tumor cell lines were exposed in vitro to fractionated X-irradiation and were then shown to express resistance to multiple antitumor drugs, including vincristine, etoposide and cisplatin. In these experiments the radiation was delivered as 10 fractions of 5 Gy (dose resulting in 1 log cell kill) given intermittently over several months. We now report that a comparable multidrug-resistance profile is expressed by human SK-OV-3 human ovarian tumor cells exposed in vitro to low dose (2 Gy) twice-daily fractions of X-rays given for 5 days on two consecutive weeks, essentially mimicking clinical practice, involving an overexpression of two MDR-associated proteins, P-glycoprotein and the multidrug resistance protein 1 (MRP1), with the latter being readily detectable by immunocytochemistry.

An improved method for STR analysis of bloodstained denim

Indigo dye is used to dye denim and other fabrics. It is now accepted that if this is co-extracted with the DNA, it may inhibit PCR amplification. A simple, improved method is described for the extraction of DNA from bloodstained denim for PCR amplification and short tandem repeat (STR) analysis. The DNA was extracted by constructing a blotting system using capillary action to draw a saline solution through the denim. The transferred material was collected onto nylon membranes and these were processed by chelex extraction. A variety of coloured denim substrates and other heavily dyed fabrics, including case work samples were used. In all cases the DNA was extracted, amplified and typed correctly.

Preliminary immunocytochemical studies of MDR-1 and MDR-3 Pgp expression in B-cell leukaemias

P-glycoproteins (Pgps) belong to the family of ATP binding cassette (ABC) transporter proteins. In humans two Pgp genes have been identified; mdr-1 and mdr-3. Classical Multiple Drug Resistance (MDR) is associated with over expression of the mdr-1 gene product, P-170. No role for mdr-3 in MDR has yet been proven. However there is evidence that mdr-3 overexpression may be associated with drug resistance in certain B-cell lymphocytic leukaemias. In an immunocytochemical study we have looked at a selection of B-cell leukaemias for mdr-1 and mdr-3 encoded Pgp expression using monoclonal antibodies specific for the mdr-1 and mdr-3 encoded gene products. In B-CLL patients a differential pattern of MDR-3 positive staining was observed; suggesting that MDR-3 positivity may be associated with a more malignant phenotype in B-CLL. This pattern was not observed with MDR-1 positivity. We also observed MDR-3 positivity in an AML stage M5a patient which is the first report of MDR-3 Pgp expression being detected in AML; suggesting that MDR-3 Pgp expression may be limited to particular subtypes of this disease. Results from B-NHL cases were inconclusive with varying expression of MDR-1 and MDR-3 Pgps observed. Work is currently underway to further explain the significance of these findings.

A new monoclonal antibody that specifically recognises the MDR-3-encoded gene product

The MDR-3-encoded P-glycoprotein (Pgp) is highly expressed in liver and is thought to function as a hepatic transporter of phospholipids into bile. However its role, if any, in other tissues remains undefined. Although transfection experiments have indicated that it may be unable to confer drug resistance, there is evidence that it may be involved in drug resistance in certain B-cell leukaemias. To date, most work on clinical samples has been performed at the mRNA level; limited work has been performed using polyclonal antibodies raised to MDR-3 and mdr-2 (the murine equivalent of MDR-3). We have generated a new monoclonal antibody, termed 6/1G, which specifically recognises the human MDR-3 gene-encoded product. Antibody 6/1G was produced by in vitro immunisation of spleen cells from BALB/c mice with a synthetic 12-amino acid peptide. Cells from MDR-3 transgenic mice showed consistent membranous staining with antibody 6/1G. Immunoblotting with 6/1G identified a band at 170 kDa on lysates of MDR-3 transgenic cells. Preliminary results with a range of B-cell leukaemias suggest that MDR-3 Pgp positivity may be a marker for a more malignant phenotype in B-CLL. Antibody 6/1G may be useful in defining a role for MDR-3 in malignancy and drug resistance, as well as in certain liver diseases such as progressive familial intracholeostasis.

Rat ultrasound model for measuring pain resulting from intramuscularly injected antimicrobials

Rats emit ultrasonic vocalizations in situations involving anxiety or stress, defense, and submission. This study demonstrates the use of ultrasonic vocalizations as a quantitative measure of pain associated with intramuscular (i.m.) injections. Intramuscularly administered cephalosporins used in a comparative evaluation of pain in humans were chosen to validate this rat model. Three groups of four rats each received an intramuscular injection of either drug first, and then placebo, or placebo and then drug. The three drugs used in this study were cefonicid, cefoxitin, and cefamandole; saline was used as the placebo. Ultrasonic vocalizations were measured from 20 kHz to 100 kHz. The number of vocalizations ranged from 50 milliseconds to 500 milliseconds and most of the vocalizations occurred between 60 kHz and 80 kHz. Rats injected with cefoxitin, cefamandole, cefonicid, and saline vocalized an average of 36 +/- 11, 33 +/- 9, 28 +/- 7, and 11 +/- 6 times respectively. The response to all three antimicrobials differed significantly when compared with placebo (p < 0.01), however, there was no significant difference between the number of vocalizations for each antimicrobial injection. Further research may allow the correlation of the total duration of each vocalization, with the individual frequencies such as the 22 kHz and the 55 kHz components and with the amount of pain associated with the injection. This correlation could then be used to further identify differences in the amount of pain associated with each antimicrobial injection without increasing the sample size.

Monoclonal antibodies raised to paraffin wax embedded archival tissue; feasibility study of their potential to detect novel antigenic markers

A study to determine the feasibility of using archival paraffin wax embedded tissue to generate monoclonal antibodies is described. Specifically, monoclonal antibodies were raised to paraffin wax embedded normal human kidney tissue to test the possibility of producing antibodies to such tissue samples prior to attempting generation of antibodies to valuable archival tissue. Multiple sections (10 x 5 microm) were pooled and dewaxed as for immunohistochemical procedures and combined with Freund's adjuvant for immunization of BALB/c mice in vivo. Immunized spleen cells were fused with SP2 myeloma cells and subsequent clones screened on paraffin wax embedded normal human kidney sections, a range of cell lines and normal mouse tissue. Supernatants from 11 wells (from a total of 90 wells screened) showed different staining patterns on sections of paraffin wax embedded kidney. One clone, 1/11C, (isotype IgG1) which exhibited strong staining on all kidney tubules by immunohistochemical studies (glomeruli interstitium and vessels were unstained) and identified a band at 52 kDa on immunoblots of dewaxed kidney tissue (as used for immunogen) was chosen for further characterization. Immunoblotting of five mammalian cell lines showed differential expression of this 52 kDa band (distinct expression on 3/5, weak expression on 2/5 cell lines) whereas, all cell lines displayed a band at 44 kDa and a third band at 70 kDa was observed on 2/5 cell lines. In mouse tissue extracts, the 52 kDa band was identified in kidney tissue only (not in the lung, liver or spleen) with the 44 kDa and 70 kDa bands weakly expressed in all tissues. This preliminary investigation of a novel approach to identifying possible new antigenic markers or producing monoclonal antibodies which react better to known antigens on sections of paraffin wax embedded tissue showed that this method is feasible. The need to have a comprehensive screening system in place and the ability to identify potentially useful clones after the initial screening is paramount due to the relative scarcity of screening material (archival tissue sections) and the tedious nature of the screening method.

The utility of patch tests using larger screening series of allergens

BACKGROUND

The number of patch test allergens available within the United States for routine commercial purchase is limited. Allergens chosen for inclusion in routine screening series or patch test trays vary, and the degree of information obtained from any series may or may not serve a patient's needs.

OBJECTIVE

Knowledge of how well the allergens chosen for inclusion in the two commercially available sources perform compared with a more expansive panel of tests can help physicians select the more appropriate tests.

METHODS

From 1994 to mid-1997, 554 patients were tested with allergens recommended by the North American Contact Dermatitis Group (NACDG). This included all allergens currently available from both current domestic sources, although not in the identical form used by the Thin-layer Rapid Use Epicutaneous Test (TRUE) test (Glaxo Dermatology, Research Triangle Park, NC). Another 185 patients were tested with supplemental series of allergens.

RESULTS

The larger the series of allergens used, the more positive tests were found and the more relevant tests as well. Hermal patch test allergens identified about 55% of the information found by the NACDG series; the TRUE test allergens (but not in the TRUE test system) identified 65%. Of the 103 reactions to supplemental allergens not found by the NACDG series, 59 were relevant.

CONCLUSION

Larger series of allergens can enhance accurate diagnosis of allergic contact dermatitis. No single arbitrary series of allergens can adequately survey the contemporary environment of individual patients. Selection of allergens for testing requires consideration of the patient's history and access to appropriate environmental contactants.

A new mdr-1 encoded P-170 specific monoclonal antibody: (6/1C) on paraffin wax embedded tissue without pretreatment of sections

AIMS

The generation and characterisation of a monoclonal antibody that specifically recognises the mdr-1 encoded protein, P-glycoprotein (P-170), on routinely processed formalin fixed, paraffin wax embedded tissue sections.

METHODS

The monoclonal antibody, designated 6/1C, was produced following a combination of in vivo and in vitro immunisation regimens in Balb/c mice with a synthetic 12 amino acid peptide that corresponds to amino acids 21-32 (believed to be intracellularly located) of P-170 and has insignificant homology with the mdr-3 encoded P-170. Antibody 6/1C was characterised by western blotting and immunocytochemistry on cytospins of paired multidrug resistant or sensitive cell lines, including mdr-1 and mdr-3 transfected cells, and by immunohistochemistry on normal and malignant formalin fixed paraffin wax embedded tissue sections.

RESULTS

Antibody 6/1C showed a single band at 170 kDa on western blots of multidrug resistant cell lysates and mdr-1 transfected cell lysates that was absent on similar preparations of drug sensitive cells and mdr-3 transfected cells. Immunocytochemical studies on cytospins of multidrug resistant cells and mdr-1 transfected cells revealed strong inner plasma membrane/cytoplasmic staining. Staining was negligible on drug sensitive cells and cells transfected with the mdr-3 gene. Immunohistochemical studies on formalin fixed, paraffin wax embedded normal adult kidney, liver, and breast tissue and a range of fetal tissues exhibited staining patterns of a variety of secretory surfaces consistent with documented mdr-1 specific staining. Specific staining of malignant cells in similarly treated sections of breast tumours was seen also with antibody 6/1C. Staining on paraffin wax embedded tissue with this antibody did not require any pretreatment of tissue sections.

CONCLUSIONS

This new monoclonal antibody, chosen for its specificity with the mdr-1 encoded P-170 and its reactivity on routinely fixed paraffin wax embedded tissue samples without pretreatment, appears to be useful for the investigation of P-170 in archival material. It is especially useful for retrospective studies on pretreatment and post-treatment tissue sections, and could help establish when and how rapidly mdr-1 associated drug resistance develops during chemotherapeutic regimens. Immunohistochemical assessment of P-170 expression in many cancers has potential for diagnostic purposes and may influence the choice of chemotherapeutic drugs used in the treatment of refractory tumours.