Deep learning-assisted radiomics facilitates multimodal prognostication for personalized treatment strategies in low-grade glioma

Determining the optimal course of treatment for low grade glioma (LGG) patients is challenging and frequently reliant on subjective judgment and limited scientific evidence. Our objective was to develop a comprehensive deep learning assisted radiomics model for assessing not only overall survival in LGG, but also the likelihood of future malignancy and glioma growth velocity. Thus, we retrospectively included 349 LGG patients to develop a prediction model using clinical, anatomical, and preoperative MRI data. Before performing radiomics analysis, a U2-model for glioma segmentation was utilized to prevent bias, yielding a mean whole tumor Dice score of 0.837. Overall survival and time to malignancy were estimated using Cox proportional hazard models. In a postoperative model, we derived a C-index of 0.82 (CI 0.79-0.86) for the training cohort over 10 years and 0.74 (Cl 0.64-0.84) for the test cohort. Preoperative models showed a C-index of 0.77 (Cl 0.73-0.82) for training and 0.67 (Cl 0.57-0.80) test sets. Our findings suggest that we can reliably predict the survival of a heterogeneous population of glioma patients in both preoperative and postoperative scenarios. Further, we demonstrate the utility of radiomics in predicting biological tumor activity, such as the time to malignancy and the LGG growth rate.

Changes in the implantation procedures of pacemakers during the COVID-19 pandemic in Germany

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIC

Background

During the beginning of the first pandemic wave beginning in spring 2020 a lot of elective EP procedures were set on hold. After a few months, the hospitals were allowed to proceed with their planned operations. The current investigation analyzed the changes in the number of cardiac pacemakers (PM) implantations in whole Germany.

Methods

We performed a data retrieval of the number of monthly first-time pacemaker implantations, i.e. single-, dual-chamber, or CRT-P, for the 2019 pre- and 2020 pandemic from the "Institut für das Entgeltsystem im Krankenhaus" (InEK) using OPS codes. This database provides data of all in-hospital procedures in Germany.

Results

The course of the implantation rates (January to September) is highlighted in the two figures, where figure 1 demonstrates the single- and dual-chamber PM, and figure 2 the CRT-P implantations in 2019 (blue line) compared to 2020 (red line). It can be clearly seen, that for the single- and dual-chamber PM, a gap occurs between March and Mai in 2020. On the contrary, for the sicker patients, who are in the need for CRT-P, the lines do no cross, significantly. Moreover, the number of CRT-P first-time implantations increased during May to September 2020.

Discussion

The present study highlights the course of first-time pacemaker implantations throughout the beginning of the COVID-19 pandemic in whole Germany. In contrast to single- and dual-chamber PM implantation rates, the number of CRT-P implantations remained stable during the first three months of the pandemic and then exceeded the rates from 2019. The progressive nature of heart failure resulting in the need for CRT may be one reason for not postponing the first-time implantation in the months March to May 2020.

The effect of spironolactone on diastolic function in haemodialysis patients

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent in patients on maintenance haemodialysis (HD) and lacks effective treatment. We investigated the effect of spironolactone on cardiac structure and function with a specific focus on diastolic function parameters. The MiREnDa trial examined the effect of 50 mg spironolactone once daily versus placebo on left ventricular mass index (LVMi) among 97 HD patients during 40 weeks of treatment. In this echocardiographic substudy, diastolic function was assessed using predefined structural and functional parameters including E/e’. Changes in the frequency of HFpEF were analysed using the comprehensive ‘HFA-PEFF score’. Complete echocardiographic assessment was available in 65 individuals (59.5 ± 13.0 years, 21.5% female) with preserved left ventricular ejection fraction (LVEF > 50%). At baseline, mean E/e’ was 15.2 ± 7.8 and 37 (56.9%) patients fulfilled the criteria of HFpEF according to the HFA-PEFF score. There was no significant difference in mean change of E/e’ between the spironolactone group and the placebo group (+ 0.93 ± 5.39 vs. + 1.52 ± 5.94, p = 0.68) or in mean change of left atrial volume index (LAVi) (1.9 ± 12.3 ml/m² vs. 1.7 ± 14.1 ml/m², p = 0.89). Furthermore, spironolactone had no significant effect on mean change in LVMi (+ 0.8 ± 14.2 g/m² vs. + 2.7 ± 15.9 g/m²; p = 0.72) or NT-proBNP (p = 0.96). Treatment with spironolactone did not alter HFA-PEFF score class compared with placebo (p = 0.63). Treatment with 50 mg of spironolactone for 40 weeks had no significant effect on diastolic function parameters in HD patients.

The trial has been registered at clinicaltrials.gov (NCT01691053; first posted Sep. 24, 2012).

Who is shocked and who survives? A multi-state analysis of the NORDIC ICD trial

Background/Purpose

The interaction between the risk of arrhythmic death and a competing non-arrhythmic risk of death in patients suitable for implantable cardioverter defibrillator (ICD) implantation is not well understood. Commonly, identification of subpopulations with the largest benefit of ICD implantation has been performed by separate risk models for the outcomes death and appropriate shock therapy. The interrelation between the outcomes was not sufficiently studied.

Methods

Data were derived from the safety population of the multinational, prospectively randomized NORDIC ICD trial (N=1067) with real-word patients implanted with a single, dual or triple chamber ICD for primary or secondary prevention. Since all outcome adjudication was performed by an independent Clinical Event Committee supported by full telemonitoring data transmission, a high validity of ICD interventions could be achieved. To investigate the impact of baseline characteristics on time to first appropriate shock, death without prior appropriate shock therapy and death after appropriate shock therapy, a multi-state Cox model was computed. Missing data have been multiply imputed before analysis.

Results

At 36 months follow-up, 86.4% of the patients were alive (7.8% after appropriate shock). 11.0% and 2.6% patients died without or after a foregoing appropriate shock, respectively. The primary randomization allocation showed no significant effect on the 3 outcome types. Higher age (per 5 years) and NYHA functional class (≥III vs. ≤II) were associated with an increased risk of death without appropriate shock (HR 1.31, 95% CI 1.14–1.50, p<0.001, and HR 2.17, 95% CI 1.26–3.74, p=0.005, fig.1, accordingly). The presence of diabetes mellitus at baseline was associated with the reduced risk of the occurrence of an appropriate shock (HR 0.57, 95% CI 0.35–0.92, p=0.022). Patients with secondary prevention indication for an ICD had very high risk for an appropriate shock after ICD implantation (HR 3.21, 95% CI 2.02–5.11, p<0.001), but not for death without or with previous appropriate shock (HR 1.42, 95% CI 0.72–2.79, p=0.306, or HR 0.73, 95% CI 0.23–2.34, p=0.594 after ICD shock). Renal insufficiency and ischemic vs. nonischemic disease showed a significantly increased global effect on all three transitions (HR 1.63, 95% CI 1.18–2.24, p=0.003 and HR 1.53, 95% CI 1.06–2.20, p=0.025, respectively).

Conclusion

The new multi-state model shows the interrelation between appropriate shocks and death, as well a remarkable variation of risk factors for the transitions. Specifically, the presence of higher age and NYHA functional class ≥III at baseline were strong prognostic factors for all-cause mortality without a foregoing shock therapy, but were not predictive for an appropriate shock therapy. In this all-comer study, a significant discriminator predictive for appropriate shock therapy, but not for death was an indication for secondary prevention of sudden cardiac death.

Multi-state graph for NYHA class

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): This work was supported by Biotronik SE & Co. KG (Berlin, Germany)

EULAR/ERA-EDTA recommendations for the management of ANCA-associated vasculitis

In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

The Swiss National Registry for Primary Immunodeficiencies: report on the first 6 years' activity from 2008 to 2014

The Swiss National Registry for Primary Immunodeficiency Disorders (PID) was established in 2008, constituting a nationwide network of paediatric and adult departments involved in the care of patients with PID at university medical centres, affiliated teaching hospitals and medical institutions. The registry collects anonymized clinical and genetic information on PID patients and is set up within the framework of the European database for PID, run by the European Society of Immunodeficiency Diseases. To date, a total of 348 patients are registered in Switzerland, indicating an estimated minimal prevalence of 4·2 patients per 100 000 inhabitants. Distribution of different PID categories, age and gender are similar to the European cohort of currently 19 091 registered patients: 'predominantly antibody disorders' are the most common diseases observed (n = 217/348, 62%), followed by 'phagocytic disorders' (n = 31/348, 9%). As expected, 'predominantly antibody disorders' are more prevalent in adults than in children (78 versus 31%). Within this category, 'common variable immunodeficiency disorder' (CVID) is the most prevalent PID (n = 98/217, 45%), followed by 'other hypogammaglobulinaemias' (i.e. a group of non-classified hypogammaglobulinaemias) (n = 54/217, 25%). Among 'phagocytic disorders', 'chronic granulomatous disease' is the most prevalent PID (n = 27/31, 87%). The diagnostic delay between onset of symptoms and diagnosis is high, with a median of 6 years for CVID and more than 3 years for 'other hypogammaglobulinaemias'.

Reliability of the calculated maximal lactate steady state in amateur cyclists

Complex performance diagnostics in sports medicine should contain maximal aerobic and maximal anaerobic performance. The requirements on appropriate stress protocols are high. To validate a test protocol quality criteria like objectivity and reliability are necessary. Therefore, the present study was performed in intention to analyze the reliability of maximal lactate production rate (V.L_amax) by using a sprint test, maximum oxygen consumption (V.O_2max) by using a ramp test and, based on these data, resulting power in calculated maximum lactate-steady-state (PMLSS) especially for amateur cyclists. All subjects (n = 23, age 26 ± 4 years) were leisure cyclists. At three different days they completed first a sprint test to approximate V.La_max. After 60 min of recreation time a ramp test to assess V.O_2max was performed. The results of V.La_max-test and V.O_2max-test and the body weight were used to calculate PMLSS for all subjects. The intra class correlation (ICC) for V.La_max and V.O_2max was 0.904 and 0.987, respectively, coefficient of variation (CV) was 6.3% and 2.1%, respectively. Between the measurements the reliable change index of 0.11 mmol·l ^-1s ^-1 for V.La_max and 3.3 mlkg ^-1min ^-1 for V.O_2max achieved significance. The mean of the calculated PMLSS was 237 ± 72 W with an RCI of 9 W and reached with ICC = 0.985 a very high reliability. Both metabolic performance tests and the calculated PMLSS are reliable for leisure cyclists.

Comparison of selected lactate threshold parameters with maximal lactate steady state in cycling

The aim of the present investigation was to compare power at "onset of blood lactate accumulation" (OBLA), "individual anaerobic threshold" (IAT) and "+1.5 mmol ∙ l(-1) lactate model" with power in maximal lactate steady state (MLSS) in cycling. However, there is a lack of studies concerning the absolute individual differences between different lactate parameters and MLSS.A total of 57 male participants performed several 30-min constant-load tests to determine MLSS by measuring blood lactate concentration (BLC). Depending on BLC, power was increased or decreased by 10 W in the following 30-min test. For detecting power at different threshold parameters, an incremental test was performed that began at 40 W and increased by 40 W every 4 min.Highly significant correlations were found between OBLA and MLSS: r=0.89 (mean difference -7.4 W); IAT and MLSS: r=0.83 (mean difference 12.4W), "+1.5 mmol ∙ l(-1) lactate model" and MLSS: r=0.88 (mean difference -37.4W). On average, the parameters of OBLA and IAT approximate MLSS with no significant differences. The "+1.5 mmol ∙ l(-1) lactate model" underestimates MLSS significantly.Based on Bland-and-Altman, the comparison of power of all threshold parameters with power in MLSS shows great individual differences despite the high regression coefficients and low mean differences between these methods.

Reliability of maximal lactate-steady-state

The aim of this study was the analysis of reliability and day-to-day-variability of power (PMLSS), blood lactate concentration (BLCMLSS) and heart rate (HRMLSS) in maximal lactate- steady-state during cycle ergometry. 32 male subjects (25±3 years, 180±7 cm, 76±8 kg) have undergone several constant-load-tests lasting 30 min to determine 4 PMLSS. During the test, blood-samples were taken from the earlobe after 4, 8,10, 14, 18, 22, 26 und 30 min for detecting the BLCMLSS. PMLSS was defined as the highest workload that can be maintained without accumulation of BLC by more than 0.05 mmol/l/min during the last 20 min. Mean PMLSS was 244±45 W, according to 75% of VO2max. Mean of BLCMLSS was 5.3±1.5 mmol/l/min, mean of HRMLSS was 166±10 1/min. The coefficient of variability (CV) was calculated for PMLSS, BLCMLSS and HRMLSS with 3%, 16.6% and 6.3%, respectively. The Intra-Class-Coefficient for PMLSS, BLCMLSS and for HRMLSS was determined with 0.98 (p≤0.001), 0.71 (p≤0.001), 0.92 (p≤0.001) respectively. PMLSS and HRMLSS are characterized by a low day-to-day variability that is comparable with results of different lactate threshold concepts. In comparison to PMLSS, BLCMLSS shows a greater day-to-day-variability.

Coiling after treatment with the woven EndoBridge cerebral aneurysm embolization device. A case report

Retreatment options after the use of the newly launched Woven EndoBridge cerebral aneurysm embolization device (WEB II) are mostly unknown. Nine months after WEB II implantation, a 55-year-old female patient presented with regrowth of an MCA aneurysm. For the first time, standard balloon-assisted coiling was used to close the regrown aneurysm proximal to the WEB II implant. We report on the feasibility and safety of balloon-assisted coiling after implantation of the WEB II device.

[MR spectroscopy in dementia]

With an increasingly aging population we are faced with the problem of an increasing number of dementia patients. In addition to clinical, neuropsychological and laboratory procedures, MRI plays an important role in the early diagnosis of dementia. In addition to various morphological changes functional changes can also help in the diagnosis and differential diagnosis of dementia. Overall the diagnosis of dementia can be improved by using parameters from MR spectroscopy. This article focuses on MR spectroscopic changes in the physiological aging process as well as on changes in mild cognitive impairment a precursor of Alzheimer's dementia, in Alzheimer's dementia, frontotemporal dementia, vascular dementia and Lewy body dementia.

[The safety of long-term administration of losartan in current clinical practice: a non-intervention NCT-CZ 14/04/LOZ study]

INTRODUCTION

Losartan is the longest used angiotensin II receptor blocker in clinical practice. It is one of the first-line drugs for the treatment of hypertensive disease and there is enough data available today about its use in the treatment of the disease, including some specific situations (left ventricular hypertrophy, cerebrovascular accidents) and cases when the hypertension disease combines with another disease (e.g. diabetic nephropathy). The primary objective of the non-intervention multicentre prospective observational open clinical assessment NCT-CZ 14/04/LOZ was to verify on a large sample of patients the safety of Lozap and Lozap H in current clinical practice.

MATERIAL AND METHOD

The six-month clinical study enrolled patients with recently diagnosed hypertension and/or poorly controlled hypertension [blood pressure > or = 140/90 mm Hg: 4432 patients (96%); blood pressure: < or = 139/89 mm Hg 84 patients (2%); value unspecified: 83 patients (2%)]. A standard form was used for data acquisition. A total of 4,599 patients was enrolled (of which 2,386 women, i.e. 51.9%) with mean age 61 +/- 12 years (18-95 years; median 60 years) with additional risk factors (cardiovascular diseases in 48%, diabetes mellitus in 33%, lipid metabolism disorder in 42%, obesity in 45% and smoking in 26% of cases, respectively). 2,631 patients (57%) had previously diagnosed hypertension. The average blood pressure (BP) at enrolment in the study was 159/95mm Hg (median 160/95 mm Hg), and the average heart rate was 76 strokes/min (median 76).

RESULTS

The most frequently used dose was 50 mg of losartan (Lozap or Lozap H)--in 4,006 patients (87%) at enrolment in the study and in 3,982 patients (87%) at the end of the study. Adverse effects related to the treatment during the study were reported in a total of 9 patients (0.2%). The therapy was assessed as well tolerated in 96% of patients (4,409), as fairly tolerated in 3% of patients (131) and as poorly tolerated in 0.1% of patients (4). Systolic and diastolic blood pressure decreased by 23mm Hg and 14mm Hg respectively to a mean value of 136/81 mm Hg (median 135/80mm Hg) (P < 0.001 for both systolic and diastolic BP). Improvement in patient status was recorded in 93% of cases (4,254 patients) and no change was recorded in 6% of cases (294 patients).

CONCLUSION

Losartan in the form of Lozap or Lozap is a safe and effective treatment of patients with hypertensive disease. It is effective and safe beginning with the dose of 50 mg and its combination with a diuretic represents a good and safe therapy in patients with insufficient BP response to a 50 mg dose of losartan alone. In case of poor blood pressure response the dose has to be titrated to 100 mg.

EULAR recommendations for the management of primary small and medium vessel vasculitis

OBJECTIVES

To develop European League Against Rheumatism (EULAR) recommendations for the management of small and medium vessel vasculitis.

METHODS

An expert group (consisting of 10 rheumatologists, 3 nephrologists, 2 immunologists, 2 internists representing 8 European countries and the USA, a clinical epidemiologist and a representative from a drug regulatory agency) identified 10 topics for a systematic literature search using a modified Delphi technique. In accordance with standardised EULAR operating procedures, recommendations were derived for the management of small and medium vessel vasculitis. In the absence of evidence, recommendations were formulated on the basis of a consensus opinion.

RESULTS

In all, 15 recommendations were made for the management of small and medium vessel vasculitis. The strength of recommendations was restricted by low quality of evidence and by EULAR standardised operating procedures.

CONCLUSIONS

On the basis of evidence and expert consensus, recommendations have been made for the evaluation, investigation, treatment and monitoring of patients with small and medium vessel vasculitis for use in everyday clinical practice.

EULAR recommendations for the management of large vessel vasculitis

OBJECTIVES

To develop European League Against Rheumatism (EULAR) recommendations for the management of large vessel vasculitis.

METHODS

An expert group (10 rheumatologists, 3 nephrologists, 2 immunolgists, 2 internists representing 8 European countries and the USA, a clinical epidemiologist and a representative from a drug regulatory agency) identified 10 topics for a systematic literature search through a modified Delphi technique. In accordance with standardised EULAR operating procedures, recommendations were derived for the management of large vessel vasculitis. In the absence of evidence, recommendations were formulated on the basis of a consensus opinion.

RESULTS

Seven recommendations were made relating to the assessment, investigation and treatment of patients with large vessel vasculitis. The strength of recommendations was restricted by the low level of evidence and EULAR standardised operating procedures.

CONCLUSIONS

On the basis of evidence and expert consensus, management recommendations for large vessel vasculitis have been formulated and are commended for use in everyday clinical practice.

The leucotriene receptor antagonist montelukast and the risk of Churg-Strauss syndrome: a case-crossover study

BACKGROUND

There has been some concern that leucotriene receptor antagonists might precipitate the onset of Churg-Strauss syndrome (CSS). A study was undertaken to investigate the relationship between the leucotriene receptor antagonist montelukast and the onset of CSS.

METHODS

Medication histories of 78 patients with CSS from France and Germany were retraced by questioning the patients, treating physicians and dispensing pharmacists, and from medical records. Using a case-crossover research design, exposures to montelukast and other asthma medications during the 3-month "index" period immediately preceding the onset of CSS were compared with those of four previous 3-month "control" periods. Odds ratios (ORs) were computed by conditional logistic regression.

RESULTS

The ORs for CSS onset were 4.5 (95% CI 1.5 to 13.9) for montelukast, 3.0 (95% CI 0.8 to 10.5) for inhaled long-acting beta(2) agonists, 1.7 (95% CI 0.5 to 5.4) for inhaled corticosteroids and 4.0 (95% CI 1.3 to 12.5) for oral corticosteroids. Montelukast exposure during control periods increased temporally over three consecutive calendar periods of CSS onset from 1999 to 2003 (p(trend) <0.0001).

CONCLUSION

Montelukast use was associated with a 4.5-fold higher risk of CSS onset within 3 months. However, the positive estimates obtained for other long-term asthma control medications suggest that this link might be confounded by a general escalation of asthma therapy before CSS onset. The association between montelukast and CSS observed in this study is probably also explained by the increasing use of this medication over time.

[Risk of infection during treatment with tumor necrosis factor-alpha inhibitors]

Tumor necrosis factor-alpha (TNF) is essential for immune defense. TNF plays a major role in the recruitment of inflammatory cells to the site of infection and in the formation and maintenance of granulomas. In addition, it plays a primary and detrimental role in chronic autoimmune diseases. Drugs that inhibit TNF are effective in the treatment of inflammatory rheumatic and autoimmune diseases. However, the three currently available TNF antagonists (etanercept, infliximab and adalimumab) decrease host resistance to granulomatous diseases such as tuberculosis. The incidence of tuberculosis in patients treated with TNF antagonists is higher than in the general population. There are a number of case reports describing the association of TNF-antagonists and the presentation of other infectious diseases such as histoplasmosis, listeriosis, coccidioidomycosis, candidiasis and aspergillosis. These case reports, however, are anecdotal. Nonetheless, patients treated with TNF antagonists are immunocompromised and infectious diseases are most likely more frequent and may present differently than expected. In this review, we describe the role of TNF in constraining infectious diseases, the difference between the three available TNF antagonists, and we discuss the relevant clinical data published in the literature as related to the risk of anti-TNF therapy for infectious diseases.

[SAPHO or Sappho? 43-year-old patient, housewife]

Wir beschreiben anhand eines Falles mit den typischen Symptomen eines SAPHO-Syndromes ein bislang ursächlich und pathogenetisch nicht erklärtes und damit nicht gut eingeordnetes Krankheitsbild, welches seit einigen Jahren in der rheumatologischen Gemeinde populär ist. Unsere Patientin wies die typischen Symptome und Befunde auf, welche bislang beschrieben worden sind. Da die Patientin auf NSAR gut ansprach, wurde auf eine invasive, nicht validierte Diagnostik (Knochenbiopsie) verzichtet. Eine kurze Übersicht wird abgehandelt.

Endoscopic fluorescence detection of low and high grade dysplasia in Barrett's oesophagus using systemic or local 5-aminolaevulinic acid sensitisation

BACKGROUND AND AIMS

Barrett's oesophagus is associated with an increased risk of cancer. As dysplasia is not visible during routine endoscopy, random biopsies in the four quadrants every 1-2 cm are recommended. Endoscopic fluorescence detection (EFD) after sensitisation with 5-aminolaevulinic acid (5-ALA) with different modes and concentrations was assessed to optimise the technique for detection of dysplasia or early cancers. 5-ALA is converted intracellularly to protoporphyrin IX which accumulates in malignant tissue and can be detected by typical red fluorescence after illumination with blue light.

METHODS

In 47 patients with Barrett's oesophagus, 10 with known dysplasia, 58 fluorescence endoscopies were performed after sensitisation with different concentrations of 5-ALA given orally (5, 10, 20, 30 mg/kg) or locally (500-1000 mg) by spraying the mucosa via a catheter. EFD was performed 4-6 hours after systemic and 1-2 hours after local sensitisation using a special light source delivering white or blue light. A total of 243 biopsies of red fluorescent (n=113) and non-fluorescent areas (n=130) were taken.

RESULTS

In three patients, two early cancers and dysplasia, not visible during routine endoscopy, were detected by EFD. Thirty three biopsies revealed either low or high grade dysplasia. Sensitivity for detection of dysplastic lesions ranged from 60% after local sensitisation with 500 mg to 80%, 100%, and 100% after systemic application of 5-ALA 10, 20, and 30 mg/kg, respectively. However, specificity was best for local sensitisation (70%) while systemic administration revealed values between 27% and 56%. Using 5 mg/kg, no red fluorescence in dysplastic lesions was found. No severe side effects were noted.

CONCLUSION

EFD is a promising tool to detect non-visible dysplastic lesions in Barrett's oesophagus using 5-ALA sensitisation. A randomised controlled study is now indicated to compare the efficacy of EFD with the standard technique of four quadrant random biopsies.

[Photodynamic diagnosis of gastrointestinal precancerous lesions after sensitization with 5-aminolevulinic acid. A pilot study]

BASIC PROBLEM AND OBJECTIVE

Endoscopic diagnosis of gastrointestinal precancerous and cancerous lesions is difficult, often even impossible. This study was undertaken to find out whether premalignant or suspected malignant tumors can be diagnosed by preceding sensitization with 5-aminolaevulinic acid (ALA), which in tumors is transformed in increased amounts into photosensitizing protoporphyrin IX, the latter being recognized by its characteristic red fluorescence on exposure to blue light.

PATIENTS AND METHODS

20 patients with known mild or moderately severe dysplasias (Barrett's esophagus, n = 8; colorectal adenoma, n = 3; ulcerative colitis n = 2, and gastric polyps or mucosal changes suspicious of malignancy, n = 5. Two patients with squamous-cell carcinoma, who after radio- and chemotherapy were endoscopically free of tumor, were sensitized with different concentrations of ALA (orally: 5-30 mg/kg; or locally: 3 g in 100 ml 0.9% NaCl). Photodynamic diagnosis (PDD) took place 4-8 h after oral and ca. 1-2 h after local sensitization with blue light (D-light, Storz, Tuttlingen, Germany).

RESULTS

Definite red fluorescence with demonstration of dysplasia was found in three of four patients with Barrett's esophagus. Biopies from nonfluorescent areas were free of dysplasia. Two gastric adenomas (10 mg/kg ALA with high-grade dysplasia were definitively endoscopically by their red fluorescence. In one patient mild dysplasia was found in a non-fluorescent area after radio- and chemotherapy of an esophageal carcinoma. Dysplasias were also seen in the rectal biopsy after local applications.

CONCLUSIONS

PDD makes it possible for the first time to visualize precancerous lesions of the gastrointestinal tract after preceding ALA sensitization. PDD is a highly promising method for monitoring patients with gastrointestinal disease and an increased risk of cancer, and for clarifying the diagnosis of mucosal changes suspicious of malignancy.

Preferential exclusion of hybrids in mixed pollinations between oilseed rape (Brassica napus) and weedy B. campestris (Brassicaceae)

In most experimental hybridizations between oilseed rape (Brassica napus) and weedy B. campestris, either intra- or interspecific pollen has been applied to individual flowers. Under field conditions, however, stigmas will often receive a mixture of the two types of pollen, thereby allowing for competition between male gametophytes and/or seeds within pods. To test whether competition influences the success of hybridization, pollen from the two species was mixed in different proportions and applied to stigmas of both species. The resulting seeds were scored for paternity by isozyme and randomly amplified polymorphic DNA analysis. Using data on the proportion of fully developed seeds and the proportion of these seeds that were hybrids, a statistical model was constructed to estimate the fitness of conspecific and heterospecific pollen and the survival of conspecific and heterospecific zygotes to seeds. B. campestris pollen in B. napus styles had a significantly lower fitness than the conspecific pollen, whereas no difference between pollen types was found in B. campestris styles. Hybrid zygotes survived to significantly lower proportions than conspecific zygotes in both species, with the lowest survival of hybrid zygotes in B. napus pods. This is in contrast to the higher survival of hybrid seeds in B. napus than in B. campestris pods when pollinations are made with pure pollen. Altogether, the likelihood of a foreign pollen grain producing a seed was much lower on B. napus than on B. campestris. In addition, pods on B. napus developed to a lower extent the more heterospecific pollen was in the mix, whereas this had no effect on B. campestris.

SLAM and its role in T cell activation and Th cell responses

Following the initial events of T cell activation, triggered by binding of specific peptide-MHC complex to the TCR for antigen and engagement of costimulatory molecules, a number of activation molecules are expressed on the cell surface. Many of these molecules regulate T cell function, T-T cell interactions and the interaction of T cells with other cells. One such molecule is SLAM, a multifunctional 70 kDa glycoprotein member of the Ig superfamily with multiple isoforms. SLAM is rapidly induced on naive T cells and B cells following activation. Engagement of SLAM by a specific antibody (mAb A12) results in IL-2-independent T cell expansion and induction/up-regulation of IFN-gamma by activated T cells, including Th2 cells. SLAM was found to be a high-affinity self-ligand mediating molecular and cellular homophilic interactions. In this review we discuss SLAM as a receptor involved in T cell expansion and in directing immune responses to a Th0-Th1 pathway.

Generation and characterization of a human monoclonal autoantibody that acts as a high affinity interleukin-1 alpha specific inhibitor

Interleukin-1 (IL-1) defines two polypeptides, IL-1 alpha and IL-1 beta, that possess a wide spectrum of biological effects. Two natural antagonists of IL-1 action have been characterized: the IL-1 receptor antagonist (IL-1Ra) and a soluble form of the type II IL-1 receptor. Neutralizing autoantibodies to IL-1 alpha have also been detected in sera of healthy individuals and patients with autoimmune or inflammatory diseases. To characterize such antibodies molecularly, we attempted to generate B cell clones producing anti-IL-1 alpha human monoclonal antibody (HuMAb) by combining Epstein-Barr virus-immortalization and CD40-activation of B lymphocytes from individuals with circulating anti-IL-1 alpha. We describe herein the generation and properties of a natural IgG4/kappa anti-IL-1 alpha monoclonal autoantibody, HuMAb X3, that bound specifically to human IL-1 alpha, but not to IL-1 beta and IL-1Ra, with a high affinity (Kd = 1.2 x 10(-10)M). HuMAb X3 inhibited IL-1 alpha binding to IL-1 receptors and neutralized biological activities of both recombinant and natural forms of IL-1 alpha. A recombinant form of HuMAb X3 was found to display identical specific IL-1 alpha antagonism. The presence of somatic mutations within X3 variable regions suggests an antigen-driven affinity maturation. This study extends the demonstration of the presence of high affinity neutralizing anti-IL-1 alpha autoantibodies that can function as a third type of IL-1 antagonist.

Application of physicians' predictions of meal and exercise effects on blood glucose control to a computer simulation

Our aim was to develop a computer simulator program that allows patients to practise insulin dose and dietary adjustment on a day of planned exercise, and shows the resulting blood glucose response in an average diabetic patient. The degree of blood glucose change predicted by the program was determined from changes predicted by five local specialists in seven hypothetical scenarios involving exercise +/- dietary or insulin dose adjustments. The program was then tested against 18 outside specialists' responses in 7 different scenarios. The program simulates the 24 h glycaemic response after 45 min mild or moderate exercise starting 2 h after meals, as well as changes to this response induced by alterations in dietary carbohydrate and/or insulin dose. Coefficients of variation of specialists' blood glucose predictions were greater for exercise (35% local, 31% outside specialists) than dietary change (7% local, 10% outside specialists; p = 0.002-0.04). The program's predicted change in blood glucose levels in the seven scenarios correlated well with the outside specialists' corresponding mean predictions (r = 0.97; p = 0.0001). We conclude that specialists are less consistent in predicting glycaemic change with exercise than with dietary alteration. Nevertheless it is possible to represent their predictions in a computerized simulator for diabetic patient education.

Will computers replace or complement the diabetes educator?

Computer programs are playing an increasingly important role in the management of diabetes and fall into various categories. Instructional programs are used to teach patients about diabetes. They cover the principles of blood glucose monitoring, diet, exercise, foot care and so on. Statistical and graphical analysis programs are used in diabetes clinics to help the physician, diabetes educator and patient detect patterns and trends in the patient's home blood glucose readings. Hand-held insulin dosage computers have been used by patients to advise them on insulin dosage adjustment on a day-to-day basis. The diabetes simulator we have recently developed allows patients to practise, and gain experience with insulin dosage adjustment; the patient decides on alterations to insulin dose, diet or the amount of exercise and the computer program demonstrates the resulting effect on blood glucose levels. Overall, computers complement and enhance, rather than replace the functions of the diabetes educator.

Assessment of experts' approach to insulin therapy and development of a simulator for diabetes insulin adjustment

OBJECTIVE

To develop a computer program (Macintosh) to predict changes in blood glucose after changes in insulin dose, timing, and regimen.

RESEARCH DESIGN AND METHODS

We established program parameters (apparent insulin action profiles; different for insulin-dependent and non-insulin-dependent diabetes mellitus) to match predictions by five diabetes specialists at our hospital of blood glucose changes after insulin-dose adjustment in 22 hypothetical patient cases. We compared the action profiles, which represent the blood glucose changes predicted by the experts with glucose-clamp studies of insulin action. We tested the program's performance in 22 different hypothetical cases against the responses of 15 specialists from outside our hospital.

RESULTS

The specialists, when predicting effects of insulin dose adjustment, integrate numerous processes (insulin action, diet, sequential blood glucose interactions). They could not specify algorithms for determining these individual factors, but they could easily predict the overall effect in the context of patient cases. The computer program's insulin-action profiles simulate this "composite" approach. The developed program incorporates multiple insulin regimens, which may be changed during the stimulation, and adjusts predicted responses according to the patient's estimated sensitivity to insulin. Its predicted change in 172 blood glucose levels (22 cases) correlated well with the corresponding means of the outside specialists (r = 0.83, P = 0.0001). Comparing this correlation with that of individual specialists ranked the program third.

CONCLUSIONS

A computer program can simulate specialists' "composite" approach (not based purely on conscious application of physiological data) to insulin adjustment.

Absence of effects of thymopentin on murine host resistance to Listeria monocytogenes

The effects of various doses of Thymopentin, the synthetic 5 aminoacid fragment of thymopoietin injected on d -4 and d -1 on murine host resistance to Listeria monocytogenes were tested. The experiments did not reveal any regular dose-effect relationship; i.e. no or only marginal (more often small negative rather than positive) effects were observed on clearance and on resistance neither during the T cell independent first hour or the first 2 days of infection in euthymic or thymus deficient nude mice, nor during the T cell dependent phase after 2 days of infection in euthymic mice. Also survival of mice was not increased in a regular dose-effect relationship with dose ranges of Thymopentin from 0.3 ng-30 mg per 30 g mouse; furthermore, injections of 3 micrograms per 30 g mouse for varying time intervals from -3 days before up to 6 days after infection had no protective effect. Thus Thymopentin apparently does not induce measurable macrophage activation directly or cannot increase macrophage activation mediated by T cells in euthymic mice nor does it induce adequate T cell responses in nude mice to promote improved resistance to Listeria.

Role of tumor necrosis factor in Listeria resistance of nude mice

The effects of sheep anti-murine recombinant tumor necrosis factor-alpha (TNF-alpha) on resistance to Listeria monocytogenes infection were studied in T cell-deficient nu/nu mice. The sheep anti-TNF-alpha antibody preparation was specific for TNF since it neutralized 300 U of recombinant murine TNF-alpha in vitro at a dilution of up to 1/1,000 but did not neutralize 32 U of interferon (IFN)-alpha, -beta or 32 U of IFN-gamma in vitro at a 1/20 dilution. When tested in vivo in sublethally Listeria-infected nu/nu or T cell-competent C57BL/6 or ICR mice, a single treatment of 0.2 ml anti-TNF-alpha given intraperitoneally on either day -1,0 or +1 resulted in the death of mice by day 5-7 due to the uncontrolled growth of Listeria; bacterial counts in spleen and liver were increased on days 3-5 by a factor of 10-1,000 in these organs. When examined histologically, organs from mice with the anti-TNF-alpha treatment contained more, and considerably bigger, lesions that exhibited central necrosis. The enhancing effect of anti-TNF-alpha on Listeria infection seemed greater early during Listeria infection on days 1-6 when compared to later phases of the infection around days 6-10. From the data presented we conclude that in addition to other lymphokines, such as IFN-gamma, TNF-alpha is of importance during the entire course of a Listeria infection in nu/nu mice.