The German Fast Track Toward Reimbursement of Digital Health Applications: Opportunities and Challenges for Manufacturers, Healthcare Providers, and People With Diabetes

BACKGROUND

Digital health applications (DiGA) supporting the management of diabetes are among the most commonly available digital health technologies. However, transparent quality assurance of DiGA and clinical proof of a positive healthcare effect is often missing, which creates skepticism of some stakeholders regarding the usage and reimbursement of these applications.

METHODS

This article reviews the recently established fast-track integration of DiGA in the German reimbursement market, with emphasis on the current impact for manufacturers, healthcare providers, and people with diabetes. The German DiGA fast track is contextualised with corresponding initiatives in Europe.

RESULTS

The option of a provisional prescription and reimbursement of DiGA while proving a positive healthcare effect in parallel may expedite the adoption of DiGA in Germany and beyond. However, hurdles for a permanent prescription and reimbursement of DiGA are high and only one of 12 that have achieved this status specifically addresses people with diabetes.

CONCLUSION

The DiGA fast track needs to be further enhanced to cope with remaining skepticism and contribute even more to a value-based diabetes care.

Photoinduced bidirectional switching in lipid membranes containing azobenzene glycolipids

Following the reaction of biological membranes to external stimuli reveals fundamental insights into cellular function. Here, self-assembled lipid monolayers act as model membranes containing photoswitchable azobenzene glycolipids for investigating structural response during isomerization by combining Langmuir isotherms with X-ray scattering. Controlled in-situ trans/cis photoswitching of the azobenzene N = N double bond alters the DPPC monolayer structure, causing reproducible changes in surface pressure and layer thickness, indicating monolayer reorientation. Interestingly, for monolayers containing azobenzene glycolipids, along with the expected DPPC phase transitions an additional discontinuity is observed. The associated reorintation represents a crossover point, with the surface pressure and layer thickness changing in opposite directions above and below. This is evidence that the azobenzene glycolipids themselves change orientation within the monolayer. Such behaviour suggests that azobenzene glycolipids can act as a bidirectional switch in DPPC monolayers providing a tool to investigate membrane structure-function relationships in depth.

Wearable based monitoring and self-supervised contrastive learning detect clinical complications during treatment of Hematologic malignancies

Serious clinical complications (SCC; CTCAE grade ≥ 3) occur frequently in patients treated for hematological malignancies. Early diagnosis and treatment of SCC are essential to improve outcomes. Here we report a deep learning model-derived SCC-Score to detect and predict SCC from time-series data recorded continuously by a medical wearable. In this single-arm, single-center, observational cohort study, vital signs and physical activity were recorded with a wearable for 31,234 h in 79 patients (54 Inpatient Cohort (IC)/25 Outpatient Cohort (OC)). Hours with normal physical functioning without evidence of SCC (regular hours) were presented to a deep neural network that was trained by a self-supervised contrastive learning objective to extract features from the time series that are typical in regular periods. The model was used to calculate a SCC-Score that measures the dissimilarity to regular features. Detection and prediction performance of the SCC-Score was compared to clinical documentation of SCC (AUROC ± SD). In total 124 clinically documented SCC occurred in the IC, 16 in the OC. Detection of SCC was achieved in the IC with a sensitivity of 79.7% and specificity of 87.9%, with AUROC of 0.91 ± 0.01 (OC sensitivity 77.4%, specificity 81.8%, AUROC 0.87 ± 0.02). Prediction of infectious SCC was possible up to 2 days before clinical diagnosis (AUROC 0.90 at -24 h and 0.88 at -48 h). We provide proof of principle for the detection and prediction of SCC in patients treated for hematological malignancies using wearable data and a deep learning model. As a consequence, remote patient monitoring may enable pre-emptive complication management.

Influenza vaccination in patients affected by diabetes

Type 2 diabetes, obesity-related metabolic syndrome, and insulin resistance are the most common metabolic disorders associated with increased cardiovascular risk. In addition, patients with Type 2 diabetes have an increased risk for a more severe course of influenza virus infection, a common pandemic. There is increasing evidence that influenza vaccination in patients with diabetes can safely and effectively reduce all-cause mortality and cardiovascular death. The effects of vaccination appear to be more effective when using higher-dose and quadrivalent vaccines, although subgroup-specific separate analyses in patients with diabetes are lacking. Clinical recommendations address influenza vaccination in all adults with diabetes. From our point of view, it should be an integral part of treatment strategies in patients with diabetes.

Glycaemic variability is associated with all-cause mortality in COVID-19 patients with ARDS, a retrospective subcohort study

There is high mortality among intensive care unit (ICU) patients with acute respiratory distress syndrome (ARDS) caused by coronavirus disease (COVID-19). Important factors for COVID-19 mortality are diabetes status and elevated fasting plasma glucose (FPG). However, the effect of glycaemic variability on survival has not been explored in patients with COVID-19 and ARDS. This single-centre cohort study compared several metrics of glycaemic variability for goodness-of-fit in patients requiring mechanical ventilation due to COVID-19 ARDS in the ICU at University Hospital Aachen, Germany. 106 patients had moderate to severe ARDS (P/F ratio median [IQR]: 112 [87–148] mmHg). Continuous HRs showed a proportional increase in mortality risk with daily glycaemic variability (DGV). Multivariable unadjusted and adjusted Cox-models showed a statistically significant difference in mortality for DGV (HR: 1.02, (P) < 0.001, LR(P) < 0.001; HR: 1.016, (P) = 0.001, LR(P) < 0.001, respectively). Kaplan–Meier estimators yielded a shorter median survival (25 vs. 87 days) and a higher likelihood of death (75% vs. 31%) in patients with DGV ≥ 25.5 mg/dl (P < 0.0001). High glycaemic variability during ICU admission is associated with significant increase in all-cause mortality for patients admitted with COVID-19 ARDS to the ICU. This effect persisted even after adjustment for clinically predetermined confounders, including diabetes, median procalcitonin and FPG.

Feasibility of Wearable-Based Remote Monitoring in Patients During Intensive Treatment for Aggressive Hematologic Malignancies

PURPOSE

Intensive treatment protocols for aggressive hematologic malignancies harbor a high risk of serious clinical complications, such as infections. Current techniques of monitoring vital signs to detect such complications are cumbersome and often fail to diagnose them early. Continuous monitoring of vital signs and physical activity by means of an upper arm medical wearable allowing 24/7 streaming of such parameters may be a promising alternative.

METHODS

This single-arm, single-center observational trial evaluated symptom-related patient-reported outcomes and feasibility of a wearable-based remote patient monitoring. All wearable data were reviewed retrospectively and were not available to the patient or clinical staff. A total of 79 patients (54 inpatients and 25 outpatients) participated and received standard-of-care treatment for a hematologic malignancy. In addition, the wearable was continuously worn and self-managed by the patient to record multiple parameters such as heart rate, oxygen saturation, and physical activity.

RESULTS

Fifty-one patients (94.4%) in the inpatient cohort and 16 (64.0%) in the outpatient cohort reported gastrointestinal symptoms (diarrhea, nausea, and emesis), pain, dyspnea, or shivering in at least one visit. With the wearable, vital signs and physical activity were recorded for a total of 1,304.8 days. Recordings accounted for 78.0% (63.0-88.5; median [interquartile range]) of the potential recording time for the inpatient cohort and 84.6% (76.3-90.2) for the outpatient cohort. Adherence to the wearable was comparable in both cohorts, but decreased moderately over time during the trial.

CONCLUSION

A high adherence to the wearable was observed in patients on intensive treatment protocols for a hematologic malignancy who experience high symptom burden. Remote patient monitoring of vital signs and physical activity was demonstrated to be feasible and of primarily sufficient quality.

Imaging-based characterization of convective tissue properties

Convective transport is an important phenomenon for nanomedicine delivery. We present an imaging-based approach to recover tissue properties that are significant in the accumulation of nanoparticles delivered via systemic methods. The classical pharmacokinetic analysis develops governing equations for the particle transport from a first principle mass balance. Fundamentally, the governing equations for compartmental mass balance represent a spatially invariant mass transport between compartments and do not capture spatially variant convection phenomena. Further, the parameters recovered from this approach do not necessarily have direct meaning with respect to the governing equations for convective transport. In our approach, a framework is presented for directly measuring permeability in the sense of Darcy flow through porous tissue. Measurements from our approach are compared to an extended Tofts model as a control. We demonstrate that a pixel-wise iterative clustering algorithm may be applied to reduce the parameter space of the measurements. We show that measurements obtained from our approach are correlated with measurements obtained from the extended Tofts model control. These correlations demonstrate that the proposed approach contains similar information to an established compartmental model and may be useful in providing an alternative theoretical framework for parameterizing mathematical models for treatment planning and diagnostic studies involving nanomedicine where convection dominated effects are important.

Noninvasive Continuous Monitoring of Vital Signs With Wearables: Fit for Medical Use?

BACKGROUND

Wearables (= wearable computer) enable continuous and noninvasive monitoring of a range of vital signs. Mobile and cost-effective devices, combined with powerful data analysis tools, open new dimensions in assessing body functions ("digital biomarkers").

METHODS

To answer the question whether wearables are ready for use in the medical context, a PubMed literature search and analysis for their clinical-scientific use using publications from the years 2008 to 2018 was performed.

RESULTS

A total of 79 out of 314 search hits were publications on clinical trials with wearables, of which 16 were randomized controlled trials. Motion sensors were most frequently used to measure defined movements, movement disorders, or general physical activity. Approximately 20% of the studies used sensors to detect cardiovascular parameters. As for the sensor location, the wrist was chosen in most studies (22.8%).

CONCLUSION

Wearables can be used in a precisely defined medical context, when taking into account complex influencing factors.

Reliable detection of atrial fibrillation with a medical wearable under inpatient conditions (CoMMoD-A-fib)

Background

Atrial fibrillation (A-fib) is the most common arrhythmia; however, detection of A-fib is a challenge due to irregular occurrence.

Purpose

Evaluating feasibility and performance of a non-invasive medical wearable for detection of A-fib.

Methods

In the CoMMoD-A-fib trial admitted patients with a high risk for A-fib carried the wearable and an ECG Holter (control) in parallel over a period of 24 hours under not physically restricted conditions. The wearable with a tight-fit upper arm band employs a photoplethysmography (PPG) technology enabling a high sampling rate. Different algorithms (including a deep neural network) were applied to 5 min PPG datasets for detection of A-fib. Proportion of monitoring time automatically interpretable by algorithms (= interpretable time) was analyzed for influencing factors.

Results

In 102 inpatients (age 71.0±11.9 years; 52% male) 2306 hours of parallel recording time could be obtained; 1781 hours (77.2%) of these were automatically interpretable by an algorithm analyzing PPG derived intervals. Detection of A-Fib was possible with a sensitivity of 92.7% and specificity of 92.4% (AUC 0.96). Also during physical activity, detection of A-fib was sufficiently possible (sensitivity 90.1% and specificity 91.2%). Usage of the deep neural network improved detection of A-fib further (sensitivity 95.4% and specificity 96.2%). A higher prevalence of heart failure with reduced ejection fraction was observed in patients with a low interpretable time (p=0.080).

Conclusion

Detection of A-fib by means of an upper arm non-invasive medical wearable with a high resolution is reliably possible under inpatient conditions.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Internal grant program (PhD and Dr. rer. nat. Program Biomedicine) of the Faculty of Health at Witten/Herdecke University, Germany. HELIOS Kliniken GmbH (Grant-ID 047476), Germany

Reliable Detection of Atrial Fibrillation with a Medical Wearable during Inpatient Conditions

Atrial fibrillation (AF) is the most common arrhythmia and has a major impact on morbidity and mortality; however, detection of asymptomatic AF is challenging. This study sims to evaluate the sensitivity and specificity of non-invasive AF detection by a medical wearable. In this observational trial, patients with AF admitted to a hospital carried the wearable and an ECG Holter (control) in parallel over a period of 24 h, while not in a physically restricted condition. The wearable with a tight-fit upper armband employs a photoplethysmography technology to determine pulse rates and inter-beat intervals. Different algorithms (including a deep neural network) were applied to five-minute periods photoplethysmography datasets for the detection of AF. A total of 2306 h of parallel recording time could be obtained in 102 patients; 1781 h (77.2%) were automatically interpretable by an algorithm. Sensitivity to detect AF was 95.2% and specificity 92.5% (area under the receiver operating characteristics curve (AUC) 0.97). Usage of deep neural network improved the sensitivity of AF detection by 0.8% (96.0%) and specificity by 6.5% (99.0%) (AUC 0.98). Detection of AF by means of a wearable is feasible in hospitalized but physically active patients. Employing a deep neural network enables reliable and continuous monitoring of AF.

1350Outcome after diagnosis with hypertrophic cardiomyopathy: a nationwide study

Background

Patients with hypertrophic cardiomyopathy (HCM) are generally considered to have an increased morbidity and mortality due to symptomatic heart failure, atrial fibrillation, stroke and sudden cardiac death. Data reporting the mortality compared with background populations are however conflicting and primarily based on small cohorts from tertiary centers.

Purpose

We aimed to investigate whether a nationwide cohort of patients with HCM had an increased risk of death compared with a matched cohort derived from the general Danish population.

Methods

Using nationwide registries, we identified all patients with a first-time HCM diagnosis in Denmark between 2007 and 2016. Patients were matched 1:5 on age, sex and HCM diagnosis date to controls using risk set sampling. The study population was followed until death, emigration, or end of study period Jan. 1, 2017–whichever came first. Mortality was compared using Kaplan Meier plots and multivariable adjusted Cox proportional hazard analysis.

Results

We identified 3010 patients diagnosed with HCM (53.8% male) per registry codes. Men were on average 8.5 years younger at diagnosis than women (62.6 years [p25-p75: 49.8–73.9] vs. 71.1 years [p25-p75: 59.7–80.6]). Patients with HCM had more comorbidities than matched controls. The median time of follow-up was 4.4 years (p25-p75: 2.3, 6.7). For HCM patients and matched controls, 1-year, 5-year and 10-year probabilities of death were 10% (95% CI 9–12%), 28% (95% CI 26–30%) and 47% (95% CI 42–51%) and 2% (95% CI 1–3%), 13% (95% CI 12–14%) and 24% (95% CI 23–25%) respectively (Figure 1). After adjusting for comorbidities and medications a diagnosis of HCM was associated to a 107% increased risk of death (hazard ratio 2.07 [95% confidence interval 1.60, 2.68], p<0.0001).

Figure 1

Conclusion

In a Danish nationwide cohort, HCM was associated with a significantly higher risk of death compared with the background population. This study emphasizes the importance of continued, life-long follow-up of patients with HCM with the aim to anticipate and treat preventable adverse events. Furthermore, the findings stress the need to develop effective disease-modifying treatment strategies.

Multiple cytokines for the detection of Mycobacterium tuberculosis infection in children with tuberculosis

SETTING

Interferon-gamma (IFN-γ) release assays (IGRAs) play an important role in the diagnosis of Mycobacterium tuberculosis infection. However, in children with tuberculosis (TB), some studies have shown increased frequencies of false-negative or indeterminate IGRA results.

OBJECTIVE

To analyse the spectrum of different cytokines to improve the diagnostic accuracy of IGRAs in latent tuberculous infection (LTBI) and active TB.

DESIGN

We performed multiplex cytokine expression analysis of QuantiFERON® Gold In-Tube supernatants in children with active TB (n = 21) and disease-free contacts with (n = 15) and without LTBI (n = 12), to determine the sensitivity and specificity of the modified tests.

RESULTS

Of 21 initial cytokines analysed, IFN-γ and six other candidates (interleukin [IL] 2, inducible protein 10 [IP-10], IL-13, IL-1α, tumour necrosis factor alpha [TNF-α] and granulocyte-macrophage colony-stimulating factor [GM-CSF]) were significantly more elevated in children with TB and those with LTBI than in the non-infected controls. Sensitivity and specificity were similar for IFN-γ and IL-2, but lower for the remaining candidates. Notably, a subset of candidates, including IP-10, showed M. tuberculosis antigen-induced specific expression in non-infected children. None of the candidates showed differences in expression between children with TB and those with LTBI.

CONCLUSIONS

Our results did not suggest that alternative IGRA cytokines can distinguish between children with active TB and those with LTBI. IFN-γ and IL-2 showed comparable capacity in diagnosing M. tuberculosis infection in our study groups.

Deconfounding Microarray Analysis

Objectives: Microarray analysis requires standardized specimens and evaluation procedures to achieve acceptable results. A major limitation of this method is caused by heterogeneity in the cellular composition of tissue specimens, which frequently confounds data analysis. We introduce a linear model to deconfound gene expression data from tissue heterogeneity for genes exclusively expressed by a single cell type.

Methods: Gene expression data are deconfounded from tissue heterogeneity effects by analyzing them using an appropriate linear regression model. In our illustrating data set tissue heterogeneity is being measured using flow cytometry. Gene expression data are determined in parallel by real time quantitative polymerase chain reaction (qPCR) and microarray analyses. Verification of deconfounding is enabled using protein quantification for the respective marker genes.

Results: For our illustrating dataset, quantification of cell type proportions for peripheral blood mononuclear cells (PBMC) from tuberculosis patients and controls revealed differences in B cell and monocyte proportions between both study groups, and thus heterogeneity for the tissue under investigation. Gene expression analyses reflected these differences in celltype distribution. Fitting an appropriate linear model allowed us to deconfound measured transcriptome levels from tissue heterogeneity effects. In the case of monocytes, additional differential expression on the single cell level could be proposed. Protein quantification verified these deconfounded results.

Conclusions: Deconfounding of transcriptome analyses for cellular heterogeneity greatly improves interpretability, and hence the validity of transcriptome profiling results.

Sample Selection for Microarray Gene Expression Studies

Objectives: The choice of biomedical samples for microarray gene expression studies is decisive for both validity and interpretability of results. We present a consistent, comprehensive framework to deal with the typical selection problems in microarray studies.

Methods: Microarray studies are designed either as case-control studies or as comparisons of parallel groups from cohort studies, since high levels of random variation in the experimental approach thwart absolute measurements of gene expression levels. Validity and results of gene expression studies heavily rely on the appropriate choice of these study groups. Therefore, the so-called principles of comparability, which are well known from both clinical and epidemiological studies, need to be applied to microarray experiments.

Results: The principles of comparability are the study-base principle, the principle of deconfounding and the principle of comparable accuracy in measurements. We explain each of these principles, show how they apply to microarray experiments, and illustrate them with examples. The examples are chosen as to represent typical stumbling blocks of microarray experimental design, and to exemplify the benefits of implementing the principles of comparability in the setting of micro-array experiments.

Conclusions: Microarray studies are closely related to classical study designs and therefore have to obey the same principles of comparability as these. Their validity should not be compromised by selection, confounding or information bias. The so-called study-base principle, calling for comparability and thorough definition of the compared cell populations, is the key principle for the choice of biomedical samples and controls in microarray studies.

Erratum: "A microfluidic chip based model for the study of full thickness human intestinal tissue using dual flow" [Biomicrofluidics , 064101 (2016)]

[This corrects the article DOI: 10.1063/1.4964813.].

A microfluidic chip based model for the study of full thickness human intestinal tissue using dual flow

The study of inflammatory bowel disease, including Ulcerative Colitis and Crohn's Disease, has relied largely upon the use of animal or cell culture models; neither of which can represent all aspects of the human pathophysiology. Presented herein is a dual flow microfluidic device which holds full thickness human intestinal tissue in a known orientation. The luminal and serosal sides are independently perfused ex vivo with nutrients with simultaneous waste removal for up to 72 h. The microfluidic device maintains the viability and integrity of the tissue as demonstrated through Haematoxylin & Eosin staining, immunohistochemistry and release of lactate dehydrogenase. In addition, the inflammatory state remains in the tissue after perfusion on the device as determined by measuring calprotectin levels. It is anticipated that this human model will be extremely useful for studying the biology and testing novel interventions in diseased tissue.

CT, MR Imaging and Angiography in Pancreatic Apudomas

Findings at CT, MR imaging and angiography in 29 patients with pancreatic apudomas are presented. CT and angiography were performed in all the patients, MR imaging in 10. Twenty-five patients underwent laparotomy. The ability of the different imaging methods to localize the primary tumor and detect hepatic metastases was compared. CT and MR imaging depicted the primary tumor in 79% and 88% of the cases respectively, angiography in 72%. Enhancement patterns at CT and signal intensity variations at MR imaging were unspecific parameters regarding different types of tumors. CT and MR imaging were considerably more accurate than angiography in evaluating local tumor resectability. Angiography revealed more numerous small hepatic metastases (<0.5 cm) than CT or MR imaging, but missed metastases in the left lobe in 5 patients. MR imaging seems promising in localizing and characterizing pancreatic apudomas, but further evaluation is needed before any conclusion can be drawn. At present dynamic incremental CT seems mandatory in the evaluation of pancreatic apudomas. Angiography is of value for preoperative and preembolization vascular mapping, and in localizing small pancreatic apudomas not shown at CT or MR imaging. Faster dynamic thin slice CT scanning and fast-sequence MR imaging may increase the sensitivity of detecting small primary pancreatic apudomas.

Spontaneous Pathology and Routine Clinical Pathology Parameters in Aging Beagle Dogs

AstraZeneca ran a bespoke study to generate age-matched clinical pathology and histopathology data from a cohort of Beagle dogs aged between 25 and 37 months to support the use of these older animals in routine preclinical toxicology studies. As the upper age range of Beagle dogs routinely used in toxicology studies does not normally exceed 24 months, there is an absence of appropriate age-matched historical control data. The generation of such data was crucial to understand whether age-related differences in spontaneous findings might confound the interpretation of toxicology study data. While the majority of the histopathology findings in all the older dogs occurred at a similar prevalence as those expected in young adult dogs (<24 months), a number of differences were observed in the thymus (involution), bone marrow (increased adiposity), testes (degenerative changes), and lung (fibrosis, pigment and alveolar hyperplasia) that could be misinterpreted as a test article effect. Minor differences in some clinical pathology values (hemoglobin, alkaline phosphatase, absolute reticulocytes) were of a small magnitude and considered unlikely to affect the interpretation of study data.

Infektionen

Die Meldung und Erfassung von Infektionskrankheiten ist in Deutschland durch das Infektionsschutzgesetz (IfSG) geregelt. In §6 sind meldepflichtige Krankheiten nach gewissen Vorgaben geregelt.

Interferon-alpha-2b alone and combined with octreotide in primary carcinoid cell-cultures

Interferon and octreotide are two main therapeutic options in metastatic carcinoid disease. In primary cell cultures prepared from 26 previously untreated carcinoid patients interferon-alpha 2b (alpha-INF), alone and combined with octreotide, significantly reduced medium serotonin (5-HT). The amines were measured with reversed phase HPLC and electrochemical detection, total DNA with a photometric method. Interferon lowered the medium concentration of serotonin to 53% (range 42-79%), octreotide alone to 44% (range 23-48%). Neither interferon, octreotide nor the combined treatment decreased DNA content. Octreotide had no effect on intracellular 5-HT. Both interferon alone and combined with octreotide lowered intracellular 5-HT concentrations significantly. This may represent a direct biochemical effect of interferon on tryptophan metabolism.

Is the operative delivery rate in low-risk women dependent on the level of birth care? A randomised controlled trial

Objective

To investigate possible differences in operative delivery rate among low-risk women, randomised to an alongside midwifery-led unit or to standard obstetric units within the same hospital.

Design

Randomised controlled trial.

Setting

Department of Obstetrics and Gynaecology, Østfold Hospital Trust, Tromsø, Norway.

Population

A total of 1111 women assessed to be at low risk at onset of spontaneous labour.

Methods

Randomisation into one of three birth units: the special unit; the normal unit; or the midwife-led unit.

Main outcome measures

Total operative delivery rate, augmentation, pain relief, postpartum haemorrhage, sphincter injuries and intrapartum transfer, Apgar score <7 at 5 minutes, metabolic acidosis and transfer to neonatal intensive care unit.

Results

There were no significant differences in total operative deliveries between the three units: 16.3% in the midwife-led unit; 18.0% in the normal unit; and 18.8% in the special unit. There were no significant differences in postpartum haemorrhage, sphincter injuries or in neonatal outcomes. There were statistically significant differences in augmentation (midwife-led unit versus normal unit RR 0.73, 95% CI 0.59–0.89; midwife-led unit versus special unit RR 0.69, 95% CI 0.56–0.86), in epidural analgesia (midwife-led unit versus normal unit RR 0.68, 95% CI 0.52–0.90; midwife-led unit versus special unit RR 0.64, 95% CI 0.47–0.86) and in acupuncture (midwife-led unit versus normal unit RR 1.45, 95% CI 1.25–1.69; midwife-led unit versus special unit RR 1.45, 95% CI 1.22–1.73).

Conclusions

The level of birth care does not significantly affect the rate of operative deliveries in low-risk women without any expressed preference for level of birth care.

Histopathologic Features, Immunophenotyping, Clonality, and Eubacterial Fluorescence In Situ Hybridization in Cats With Lymphocytic Cholangitis/Cholangiohepatitis

Feline lymphocytic cholangitis is a poorly characterized disease complex with respect to histologic lesions, immunophenotype, and etiopathogenesis. Seventy-eight cases of feline lymphocytic cholangitis ( n = 51) and feline hepatic lymphoma ( n = 27) were reviewed using standardized histopathology, immunophenotyping (B cell and T cell), polymerase chain reaction for T-cell receptor (TCR) gene rearrangement, and fluorescence in situ hybridization (FISH) for eubacteria. Five histopathologic features in cases of lymphocytic cholangitis assisted in its differentiation from hepatic lymphoma: bile duct targeting ( n = 32, 62.7%), ductopenia ( n = 9, 17.6%), peribiliary fibrosis ( n = 37, 72.5%), portal B-cell aggregates ( n = 36, 70.6%), and portal lipogranulomas ( n = 38, 74.5%). The majority of lymphocytic cholangitis cases ( n = 35, 68.6%) were T cell predominant; 15 (29.4%) had an equal mix of B cells and T cells, and 1 (1.9%) had a B cell–predominant infiltrate; 66.6% of hepatic lymphoma cases were T-cell lymphomas. TCR clonality results were unexpected, with 17.1% of cases of lymphocytic cholangitis having clonal or oligoclonal populations and with T-cell lymphomas having variable TCR clonality (63.6% clonal or oligoclonal, 36.3% polyclonal). The majority of lymphocytic cholangitis ( n = 32 of 36, 88.8%) and all hepatic lymphoma cases had no detectable eubacteria using FISH. As demonstrated here, bile duct targeting, ductopenia, peribiliary fibrosis, portal B-cell aggregates, and portal lipogranulomas are lymphocytic cholangitis features that, along with polyclonal TCR (83%), help differentiate it from hepatic lymphoma. No strong evidence was found implicating in situ bacterial colonization as an etiopathogenesis of lymphocytic cholangitis.

Can conjunctival provocation test facilitate the diagnosis of food allergy in children?

BACKGROUND

Food allergy is common in children, occurring in 5-7.5%. The diagnosis may, however, be difficult. Elevated IgE or positive skin prick test to a food allergen is often considered proof of allergy, but may represent sensitisation without clinical manifestations. For a precise diagnosis oral challenge is necessary, but this is often not performed because of risk of serious allergic reactions. The aim of this study was to evaluate whether conjunctival provocation test would facilitate the diagnosis of IgE-mediated food allergy.

METHODS

One hundred and forty-nine children with 174 possible diagnoses of food allergy were included. General examination, skin prick test and specific IgE were performed, as well as conjunctival provocation test of the suspected food allergen. Open food challenges and double-blind placebo controlled tests were performed in order to diagnose possible food allergy.

RESULTS

Forty-six children with strongly positive conjunctival reactions (rubor, itching, oedema) to fifty food allergens were all proven to have allergy to the food in question. The children with negative conjunctival provocation tests showed no allergic reactions when challenged.

CONCLUSIONS

We find that a strongly positive conjunctival reaction to a food allergen correlates well with true allergy. An oral challenge should be carefully performed. With a negative conjunctival test an oral challenge may safely be performed.

Suppressor of cytokine signaling-3 is affected in T-cells from tuberculosisTB patients

T-cells and T-cell-derived cytokines are crucial mediators of protection against Mycobacterium tuberculosis infection, but these factors are insufficient as biomarkers for disease susceptibility. In order to define T-cell molecules involved in tuberculosis (TB), we compared gene expression profiles of T-cells from patients with active TB, healthy donors with latent M. tuberculosis infection (LTBIs) and non-infected healthy donors (NIDs) by microarray analysis. Pathway-focused analyses identified a prevalent subset of candidate genes involved in the Janus kinase (JAK)-signal transducer and activator of transcription signalling pathway, including those encoding suppressor of cytokine signalling (SOCS) molecules, in the subset of protection-associated genes. Differential expression was verified by quantitative PCR analysis for the cytokine-inducible SH2-containing protein (CISH), SOCS3, JAK3, interleukin-2 receptor α-chain (IL2RA), and the proto-oncogene serine/threonine protein kinase (PIM1). Classification analyses revealed that this set of molecules was able to discriminate efficiently between T-cells from TB patients and those from LTBIs, and, notably, to achieve optimal discrimination between LTBIs and NIDs. Further characterization by quantitative PCR revealed highly variable candidate gene expression in CD4(+) and CD8(+) T-cells from TB patients and only minor differences between CD4(+) and CD8(+) T-cell subpopulations. These results point to a role of cytokine receptor signalling regulation in T-cells in susceptibility to TB.

Atopic dermatitis in premature and term children

OBJECTIVE

To investigate the prevalence of atopic dermatitis (AD) in premature compared with term children, the frequency of food allergy in children with AD, and the possible differences in prevalence of AD in children delivered by caesarean section compared with vaginally delivered children.

DESIGN

Prospective follow-up study over 2 years.

METHOD

609 children (193 premature and 416 term) were included. At 2 years, 512 children (161 premature and 351 term) participated. Children with symptoms consistent with AD/possible food allergy were examined, and the dermatitis was evaluated according to the SCORAD index. Skin prick test, specific IgE, elimination/challenge and DBPC challenge were performed.

RESULTS

18.6% (95/512) of the children (19.9% (32/161) premature and 17.9% (63/351) term) had a diagnosis of AD. The prevalence of adverse reactions to food in all the children with AD was 15.8% (15/95) (similar in preterm and term children). AD was found in 17.5% (30/171) of children delivered by caesarean section, and 19.1% (65/341) delivered vaginally

CONCLUSIONS

The prevalence of AD in the first 2 years of life was 18.6%, with no significant difference between preterm and term children. Adverse reactions to food were found in 15.8% (a similar prevalence in premature and term children). Mode of delivery did not affect prevalence of AD.

Decision-making needs of patients with depression: a descriptive study

The study's purpose was to explore the decision-making needs of patients considering treatment options for their depression. Semi-structured interviews were guided by the Ottawa Decision Support Framework. Of 94 participants, 67 were uncertain about their decision. Common decisions identified were whether or not to take medications, attend support groups, undergo electroconvulsive therapy, and location of care. Those feeling certain were more likely to have made a decision (RR 1.37; 95% CI: 1.05, 1.78). However, 40 patients who had 'made a decision' in the recent past were uncertain about their decision. Compared with those who were certain, the uncertain group felt less informed (2.65 vs. 1.64; P < 0.001), less supported (2.63 vs. 1.88; P < 0.001) and less clear about how they valued the benefits and risks of options (2.57 vs. 1.69; P < 0.001). Other influential factors included concerns about confidentiality, distress from depression, embarrassment, panic attacks and lack of energy. Few patients wanted to defer decision making to their physician (n = 8) or family (n = 1). To support decision making, participants identified the need for: discussions with their psychiatrist, nurse or family doctor; access to printed information; and information provided by health professionals and health societies.

Chromosome aberrations in Norwegian reindeer calves exposed to fallout from the Chernobyl accident

Chromosome aberrations were analysed in 1222 peripheral blood lymphocytes from 24 reindeer, Rangifer tarandus L., calves from central Norway, where considerable fallout from Chernobyl accident had occurred, and in 1532 lymphocytes from 26 calves from three different districts in Northern Norway which were not affected by fallout from the accident. Three dicentrics, two rings, and three translocations were detected in calves from the exposed area, while no dicentrics, nor rings and only one translocation were detected in the control calves. The frequency of chromatid-type aberrations and chromosome deletions did not significantly differ between the two groups. Although the present study is based on a limited number of observations, the radioactive burden in the exposed reindeer, and the differing character of the chromosome aberrations in the two groups, might indicate that certain genetic effects have occurred as a result of the Chernobyl accident in Norwegian reindeer in the most contaminated areas.

Deconfounding microarray analysis - independent measurements of cell type proportions used in a regression model to resolve tissue heterogeneity bias

OBJECTIVES

Microarray analysis requires standardized specimens and evaluation procedures to achieve acceptable results. A major limitation of this method is caused by heterogeneity in the cellular composition of tissue specimens, which frequently confounds data analysis. We introduce a linear model to deconfound gene expression data from tissue heterogeneity for genes exclusively expressed by a single cell type.

METHODS

Gene expression data are deconfounded from tissue heterogeneity effects by analyzing them using an appropriate linear regression model. In our illustrating data set tissue heterogeneity is being measured using flow cytometry. Gene expression data are determined in parallel by real time quantitative polymerase chain reaction (qPCR) and microarray analyses. Verification of deconfounding is enabled using protein quantification for the respective marker genes.

RESULTS

For our illustrating dataset, quantification of cell type proportions for peripheral blood mononuclear cells (PBMC) from tuberculosis patients and controls revealed differences in B cell and monocyte proportions between both study groups, and thus heterogeneity for the tissue under investigation. Gene expression analyses reflected these differences in celltype distribution. Fitting an appropriate linear model allowed us to deconfound measured transcriptome levels from tissue heterogeneity effects. In the case of monocytes, additional differential expression on the single cell level could be proposed. Protein quantification verified these deconfounded results.

CONCLUSIONS

Deconfounding of transcriptome analyses for cellular heterogeneity greatly improves interpretability, and hence the validity of transcriptome profiling results.

Outcome of four weeks' intervention with probiotics on symptoms and endoscopic appearance after surgical reconstruction with a J-configurated ileal-pouch-anal-anastomosis in ulcerative colitis

OBJECTIVE

Pouchitis is a common and troublesome condition in patients operated on with ileal-pouch-anal-anastomosis (IPAA). A disturbed microecology in the pouch has been suggested as one possible explanation. In a previous double-blind, randomized, controlled study we demonstrated clinical improvement of symptoms in patients with ulcerative colitis (UC) operated on with IPAA, during intervention with live probiotic microbes Lactobacilli and Bifidobacteriae. The aim of the present study was to confirm our previous results in a much larger material, including clinical symptoms, faecal flora and endoscopic evaluation, and to compare the results in UC/IPAA patients with those of patients with familial adenomatous polyposis (FAP) with IPAA and UC patients with ileorectal anastomosis (IRA).

MATERIAL AND METHODS

Five hundred millilitres of a fermented milk product (Cultura) containing live lactobacilli (La-5) and bifidobacteriae (Bb-12) was given daily for 4 weeks to 51 UC patients and 10 patients with FAP, operated on with IPAA, and six UC patients operated on for IRA. Stool samples were cultured for examination of lactobacilli, bifidobacteriae, fungi and pH before, during and after intervention. Before, during and after intervention, endoscopic evaluation was performed. Categorized symptomatology was examined prospectively using diary cards in addition to an interview, before and on the last day of intervention.

RESULTS

The number of lactobacilli and bifidobacteriae increased significantly during intervention in the UC patients operated on with IPAA and remained significantly increased one week after intervention. Involuntary defecation, leakage, abdominal cramps and the need for napkins (category I), faecal number and consistency (category II) and mucus and urge to evacuate stools (category III) were significantly decreased during intervention in the UC/IPAA group. In the FAP group there was a significant decrease in faecal leakage, abdominal cramps and use of napkins (category I) during intervention. The median endoscopic score of inflammation was significantly decreased during intervention in the UC/IPAA patients. Blood tests, faecal fungi and faecal pH did not change significantly during intervention.

CONCLUSIONS

Results of this extended study, showing an effect of probiotics on symptoms and endoscopic inflammation in UC patients operated on with IPAA confirm our previously reported effect of probiotics on clinical symptoms and endoscopic score in a smaller, double-blind, randomized, controlled study. The significantly higher response to probiotics in families with increased risk of IBD will have to be repeated in future studies.

Sample selection for microarray gene expression studies

OBJECTIVES

The choice of biomedical samples for microarray gene expression studies is decisive for both validity and interpretability of results. We present a consistent, comprehensive framework to deal with the typical selection problems in microarray studies.

METHODS

Microarray studies are designed either as case-control studies or as comparisons of parallel groups from cohort studies, since high levels of random variation in the experimental approach thwart absolute measurements of gene expression levels. Validity and results of gene expression studies heavily rely on the appropriate choice of these study groups. Therefore, the so-called principles of comparability, which are well known from both clinical and epidemiological studies, need to be applied to microarray experiments.

RESULTS

The principles of comparability are the study-base principle, the principle of deconfounding and the principle of comparable accuracy in measurements. We explain each of these principles, show how they apply to microarray experiments, and illustrate them with examples. The examples are chosen as to represent typical stumbling blocks of microarray experimental design, and to exemplify the benefits of implementing the principles of comparability in the setting of microarray experiments.

CONCLUSIONS

Microarray studies are closely related to classical study designs and therefore have to obey the same principles of comparability as these. Their validity should not be compromised by selection, confounding or information bias. The so-called study-base principle, calling for comparability and thorough definition of the compared cell populations, is the key principle for the choice of biomedical samples and controls in microarray studies.

Testosterone modulates K(+)ATP channels in Sertoli cell membrane via the PLC-PIP2 pathway

Testosterone at physiological intratesticular concentrations induces a dose-dependent depolarisation and an increase in input resistance together with an increment of 45Ca2+ uptake in the Sertoli cells from seminiferous tubules of immature rat. Previous studies have implicated K(+)ATP channels in these testosterone actions. This study demonstrates that testosterone and sulphonylureas (glibenclamide and tolbutamide) depolarise the membrane potential, augment resistance and 45Ca2+ uptake in the Sertoli cells of seminiferous tubules from 10-15 day-old rats. These actions were nullified by the presence of the K(+)ATP channel opener diazoxide. The depolarisation was also observed with the impermeant bovine serum albumin-bound testosterone. Testosterone actions were blocked by both pertussis toxin and the phospholipase C (PLC) inhibitor U73122 implying the involvement of PLC - phosphatidylinositol 4-5 bisphosphate (PIP2) hydrolysis via G protein in testosterone actions. Polycations, including spermine and LaCl3, depolarised the membrane potential and increased the resistance. Hyperpolarisation caused by EGTA was reversed by LaCl3 and by the presence of testosterone. This last effect was nullified by the presence of U73122. All of the above results indicate that the action of testosterone on the Sertoli cell membrane is exercised on the K(+)ATP channels through PLC-PIP2 hydrolysis that closes the channel, depolarises the membrane, and stimulates 45Ca2+ uptake.

[Further development of the International Pneumoconiosis Classification--from ILO 1980 to ILO 2000 and to ILO 2000/German Federal Republic version]

The ILO (1980) Classification has been revised during recent years. The new version is now available as the International Classification of Radiographs of Pneumoconioses (Revised edition 2000). The Guidelines booklet is currently available only in English. Those involved felt it was important to maintain continuity with the ILO (1980) edition, in particular to retain the standard radiographs, despite their restricted quality, so as to ensure comparability with earlier national and international data sets. The standard films illustrating pleural abnormalities, and 'u'-shadows, have been modified and reconstituted. The most important changes relate to assessment of film quality, pleural abnormalities, and additional symbols. In Germany, film quality is characterised as "+", "+-", "+--" and "u" according to whether the ability to assess pneumoconiosis is judged to be unimpeachable ("+") to unusable ("u"). If a film is not classified as "+", then written comments regarding defects are required. For "diffuse" pleural thickening, the ILO (2000) edition now requires the presence also of obliteration of the costophrenic angle. This was not required in the earlier (1980) edition and, as previously, is also not stipulated in the German version. A minimum width of 3 mm (previously 0-5 mm), coded "a", is required both for plaques as well as for the margin to the lateral chest wall. Congruence is thus achieved for criteria, which, in German practice, lead to an indication of suspect occupational disease. Plaques on the diaphragm are not considered for measurement of extent; they are only coded as present or absent. If calcification is identified, then this must also be classified and measured as a localised plaque. Extent of calcification on its own, previously coded "0" to "3", is no longer specified. The following new symbols, illustrated by new diagrams, have been introduced: aa = atherosclerotic aorta; at = apical thickening; cg = calcified granuloma (or other non-pneumocononiotic nodules); me = mesothelioma (already previously differentiated from "ca" on the German record sheet); pa = plate atelectasis; pb= parenchymal bands; ra = rounded atelectasis; od = other disease. (Examples of the latter are illustrated diagrammatically by lobar pneumonia, aspergilloma, goiter and hiatal hernia.) Earlier national differences (ILO 1980/German Federal Republic) on particular issues have also been agreed among German "double-readers" ["Zweitbeurteiler"]. However, conformity between the original (ILO 2000) text and the national (German) modified text has been retained in large measure. The detailed descriptions of the standard films differ in certain respects from the German (1980) definitions. Some revision of individual descriptions of the films are proposed. Except for a few differences, agreement was reached here too. The definitive date for the change in Germany is expected to be in early 2004. The standard films are already available now through ILO offices in Geneva or Bonn (addresses in appendix.)