Problem of implicit assumptions about left ventricular geometry in the calculation of myocardial mass by echocardiography – a validation study with cardiac magnetic resonance

Background/Introduction

Cardiac magnetic resonance imaging (CMR) is regarded as the reference method in assessing left ventricular (LV) myocardial mass. However, 2-dimensional echocardiography (Echo) is still used due to availability and practicability.

Purpose

We sought to assess measurements of LV myocardial mass from Echo exams and validate the results with CMR on a large cohort of patients.

Methods

We analyzed 357 patients who underwent clinically indicated CMR examinations and performed a standard Echo at the same day. In Echo, the commonly used Devereux formula (CUBE) was assessed for the calculation of LV mass: 0.8 × {1.04 × [([LV end-diastolic diameter + diastolic septum-thickness + posterior wall-thickness]3 − LV end-diastolic diameter3)]} + 0.6. Mass was indexed on body surface area (g/m2). Correlation (r), regression (R2) and Bland-Altman analysis were performed in order to assess bias between the two methods. Significance was defined as a 2-tailed P value <0.05.

Results

LV myocardial mass was measured in 345 patients with CMR and Echo. The median age was 61 years [19–79], 44% were female and CMR was performed due to coronary artery diseases (45%), suspected or florid myocarditis (31%) or further diagnosis of non-ischemic heart failure (24%). LV ejection fraction (EF) ranged between 13 and 71%. We found a significant relation of measurements for myocardial mass between Echo and CMR (R2=0.6, p<0.001) (Figure 1, left). However, there was a significant proportional bias (R2=0.47, p<0.001) depending in the amount of LV mass measured (Figure 1, right). As expected, the measurement bias correlated not only with the amount of mean wall-thickness (septum & posterior wall) from Echo, but also with LV end-diastolic diameter (r=−0.55 and −0.41, p<0.001 for all). Interestingly, the amount of LV EF correlated reversely with the proportional bias (r=0.34, p<0.001).

Conclusion

The results provided by our study, highlight the problem of implicit assumptions of LV geometry in the calculation of LV myocardial mass by Echo (CUBE) compared to CMR. Furthermore, the strongly biased differences between these two measurement methods are not negligible and warrant further investigation.

Funding Acknowledgement

Type of funding sources: None.

The automatic identification of left ventricular chambers and quantification of ejection fraction using a novel artificial intelligence-based system – a validation against cardiac magnetic resonance

Background/Introduction

Cardiac magnetic resonance imaging (CMR) is regarded as the reference method in assessing left ventricular (LV) ejection fraction (EF). However, 2-dimensional echocardiography (2D-Echo) is the most frequently used technique due to availability and practicability. The interpretation of 2D-Echo examinations depends on the user's expertise and may vary between different operators. A novel vendor-independent software based on artificial intelligence (AI) performs both, automated evaluation of 2D-Echo exams and calculations of LV EF in one workflow.

Purpose

We sought to assess the ability of the AI to automatically identify appropriate LV 4- and 2-chamber views (4CV) (2CV) from 2D-Echo exams and validate the resulting EF with CMR.

Methods

We consecutively enrolled 128 patients who underwent clinically indicated CMR examinations and performed a standard 2D-Echo at the same day. The server-based AI solution recognized the optimal LV 4CV and 2CV from 2D-Echo according to quality and depth criteria and automatically performed calculation of biplane EF by endocardial borderline detection. LV EF from CMR and AI were supervised by independent cardiologists blinded to the mutual results. Pearson's correlation (R) and Bland-Altman analysis with limits of agreement (LOA) were performed in order to assess bias between the two methods. Significance was defined as a 2-tailed P value <0.05.

Results

CMR was performed and LV EF was measured in all 128 patients. The median age was 60 years [20–86], 65% were males and CMR was performed due to coronary artery diseases (33%), suspected/florid myocarditis (20%) or further diagnosis of non-ischemic heart failure (47%). Eleven cases (9%) did not pass AI's criteria due to impaired acoustic window or poor 2D-Echo images. The AI system detected either 4CV or 2CV (ratio 1.2) in 13 patients (10%), and both 4CV and 2CV in 104 patients (81% overall feasibility) with a correct classification of 100%. For these 104 patients, excellent correlation was found for AI's biplane LV EF and LV EF from CMR with r=0.91 (p<0.001) (Figure 1, left). However, the absolute mean bias between AI and CMR was 3.5% (p<0.001) and LOAs were −10.6 and +17.5% (Figure 1, right).

Conclusion

The results provided by the AI-based software showed good capabilities and a perfect classification rate to identify 4CV and 2CV. In addition, the LV EF results were excellent compared to CMR, especially since our study did not include “echocardiographically” pre-selected patients. However, differences between AI and CMR measurements are not negligible and warrant further investigation.

Funding Acknowledgement

Type of funding sources: None.

A Benchmark Environment for Neuromorphic Stereo Vision

Without neuromorphic hardware, artificial stereo vision suffers from high resource demands and processing times impeding real-time capability. This is mainly caused by high frame rates, a quality feature for conventional cameras, generating large amounts of redundant data. Neuromorphic visual sensors generate less redundant and more relevant data solving the issue of over- and undersampling at the same time. However, they require a rethinking of processing as established techniques in conventional stereo vision do not exploit the potential of their event-based operation principle. Many alternatives have been recently proposed which have yet to be evaluated on a common data basis. We propose a benchmark environment offering the methods and tools to compare different algorithms for depth reconstruction from two event-based sensors. To this end, an experimental setup consisting of two event-based and one depth sensor as well as a framework enabling synchronized, calibrated data recording is presented. Furthermore, we define metrics enabling a meaningful comparison of the examined algorithms, covering aspects such as performance, precision and applicability. To evaluate the benchmark, a stereo matching algorithm was implemented as a testing candidate and multiple experiments with different settings and camera parameters have been carried out. This work is a foundation for a robust and flexible evaluation of the multitude of new techniques for event-based stereo vision, allowing a meaningful comparison.

Early results for iCMR in atrial flutter

Funding Acknowledgements

Type of funding sources: None.

Background

 As a standard of care, ablation of typical atrial flutter involves performing cardiac catheterization under x-ray fluoroscopy. The unique ability of magnetic resonance (MR) to provide real-time functional imaging in multiple views without ionizing radiation exposure has the potential to be a powerful tool for diagnostic and interventional procedures. Real-time MR imaging-guided radiofrequency (RF) ablation has been used as a part of clinical trials.

Objective

 To implement the MR imaging-guided RF ablation of typical atrial flutter in the clinical routine.

Methods

 From January to July 2020, 15 consecutive patients with typical atrial flutter have been referred for ablation. Patient preparation, conscious sedation and groin puncture took place inside the 1.5 Tesla MR scanner as a part of an MR-only workflow. The catheter advancement as well as the RF ablation procedure have been performed under direct visualisation of catheters with integrated micro-coils using an interactive sequence with active tip tracking and automatic slice positioning in the plane where the catheter tip has been detected. During catheter advancement a single frontal plane has been used to visualize the passage of the catheter through femoral veins and inferior vena cava. With both diagnostic and ablation catheters in the right atrium, an axial stack of balanced steady-state free precession acquisitions has been acquired and used to reconstruct planes in the short- and long cardiac axis. These have been used to provide a "left- and right anterior oblique" view familiar to an interventional electrophysiologist. The subsequent catheter placement and ablation have been performed under direct visualisation in these two planes (see figure).

Results

 The ablation was successful in 14 patients, one patient had to undergo a conventional procedure on the following day. The mean time to reach right atrium and coronary sinus was 4 [3,5] and 7 [6,10] minutes, respectively. The mean total ablation duration and procedure time was 18 [12,26] and 43 [33,58] minutes, respectively. There were no adverse events.

Conclusion

 The implementation of the MR imaging-guided RF ablation of typical atrial flutter in the clinical routine is feasible and leads to similar success rates and procedure times as the conventional fluoroscopy-based ablation.

Abstract Figure.

Administration of all-trans retinoic acid after experimental traumatic brain injury is brain protective

BACKGROUND AND PURPOSE

All-trans retinoic acid (ATRA) is a vitamin A metabolite, important in the developing and mature brain. Pre-injury ATRA administration ameliorates ischaemic brain insults in rodents. This study examined the effects of post-traumatic ATRA treatment in experimental traumatic brain injury (TBI).

EXPERIMENTAL APPROACH

Male adult mice were subjected to the controlled cortical impact model of TBI or sham procedure and killed at 7 or 30 days post-injury (dpi). ATRA (10 mg kg-1, i.p.) was given immediately after the injury and 1, 2 and 3 dpi. Neurological function and sensorimotor coordination were evaluated. Brains were processed for (immuno-) histological, mRNA and protein analyses (qPCR and western blot).

KEY RESULTS

ATRA treatment reduced brain lesion size, reactive astrogliosis and axonal injury at 7 dpi, and hippocampal granule cell layer (GCL) integrity was protected at 7 and 30 dpi, independent of cell proliferation in neurogenic niches and blood-brain barrier damage. Neurological and motor deficits over time and the brain tissue loss at 30 dpi were not affected by ATRA treatment. ATRA decreased gene expression of markers for damage-associated molecular pattern (HMGB1), apoptosis (caspase-3 and Bax), activated microglia (TSPO), and reactive astrogliosis (GFAP, SerpinA3N) at 7 dpi and a subset of markers at 30 dpi (TSPO, GFAP).

CONCLUSION AND IMPLICATIONS

In experimental TBI, post-traumatic ATRA administration exerted brain protective effects, including long-term protection of GCL integrity, but did not affect neurological and motor deficits. Further investigations are required to optimize treatment regimens to enhance ATRA's brain protective effects and improve outcomes.

P457Incidence of LA fibrosis and substrate-based AF ablation success rates in HF patients

Funding Acknowledgements

The author(s) received no specific funding for this work.

Background

In heart failure (HF) patients, sinus rhythm maintenance after catheter ablation for atrial fibrillation (AF) is mandatory to achieve better long-term outcome. Presence of left atrial (LA) fibrosis significantly attenuates ablation success rates. Incidence of LA fibrosis and the effect of an individualized substrate-based ablation concept on rhythm outcome in HF patients with AF is unclear.

Methods

This study investigated 103 patients (64 years, 69% men) with persistent AF (79%) and left ventricular (LV) dysfunction (EF 33% IQR [25; 38]) undergoing first time AF ablation. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. All patients received pulmonary vein isolation (PVI). LA fibrosis ablation was individualized by (i) homogenization of small areas, (ii) linear lesions connecting fibrosis and anatomical obstacles and (iii) linear lesions isolating large fibrotic areas. Rhythm outcome was measured by continuous device monitoring (AF detection ≥ 6 min) or Holter-ECG. A total post-procedural AF burden < 0.1% was defined as successful rhythm control.

Results

LA fibrosis in the overall cohort, in paroxysmal and persistent AF patients was detected in 39/103 (38%), 6/22 (27%) and 33/81 (41%), respectively. After 11 ± 5 months and 1.2 procedures/patient, freedom from AF recurrence was similar between patients with and without LA fibrosis (33/39 (84%) vs. 54/64 (84%); p = 0.485). With continuous monitoring, 73/87 (84%) patients recorded a total AF burden < 0.1%. There was no significant difference in AF burden outcome between patients with and without LA fibrosis (3.1% SD ±17.4 vs. 2.2% SD ±8.1; p = 0.4). No correlation between presence or extent of LA fibrosis and AF burden was found; p = 0.299.

Conclusion

A substantial number of HF patients with AF have no evidence of LA fibrosis. Among HF patients with LA fibrosis, individualized substrate-based AF ablation beyond PVI was able to achieve similar ablation success.

202 Proteomic, metabolomic and fatty acid composition in lactating and non-lactating mares’ uterine fluids

In the equine industry, horse breeders aim to produce one foal per mare per year. Thus, mares are bred while nursing. In high-yielding dairy cattle, concurrent lactation and conception may affect embryo quality, but effects on uterine fluid (UF) quality are unknown. No data are available in horses. The aim of our study was to analyse the effect of nursing on protein, metabolite and fatty acid (FA) compositions of UF at ~7.5 days post-ovulation. Anglo-Arab mares (multiparous (2.7±0.9 foals), 10.8±2.5 years old) that were either nursing (N; 105±12 days of lactation) or barren (B) were inseminated with the semen of the same stallion at induction of ovulation with human chorionic gonadotrophin. Ovulation was confirmed by ultrasound within 48h. At 7.4±0.7 days post-ovulation, UF was collected with a human tampon that was left for 10min in the uterus before embryo collection. Only mares for which no embryo was collected were selected (n=5 in both groups). Trypsin digestion followed by liquid chromatography-tandem mass spectrometry analysis was used for proteomic analysis, with subsequent characterisation with the PANTHER platform using an overrepresentation test (Fisher's exact type with false discovery rate correction) with the PANTHER pathway database. An untargeted approach based on liquid chromatography-tandem mass spectrometry was performed for metabolomics (normalisation to 50µg of protein), and data were analysed with the MS Peaks to Pathways tool of the MetaboAnalyst platform, using both the GSEA and mummichog algorithms (cut-off=0.05). Fatty acid composition (% of total FA) was analysed using gas chromatography. Differences between groups were analysed using a linear model with permutation using R software with the pgirmess package (P=0.05 for significance). Altogether, 2706 proteins with at least two peptides were identified in mares’ UF, with 164 being differentially expressed. Ubiquitin proteasome, involved in embryo-endometrium interactions, was the most enriched pathway in N mares (fold enrichment=15.12; P<0.0001). For metabolomics, ubiquinone biosynthesis [MetaFishNet, P=0.02; NES (Enrichment Score for the variable)/(mean of all Enrichment Score in all permutations in the dataset)=1.84] was enriched in N mares. N-Glycans, mainly guanosine diphosphate mannose (Kyoto Encyclopedia of Genes and Genomes, P=0.04; NES=−1.33) and leukotriene biosynthesis (Biocyc; P=0.006; NES=−1.31), were enriched in B mares with differentially expressed leukotrienes C4/D4. The proportion of saturated FA was higher in N vs. B mares (38.4±3.6% vs. 33.2±3.6%; P=0.03), probably due to increased palmitic (P=0.08) and stearic (P=0.08) acid proportions. In conclusion, pathways involved in uterine receptivity and inflammation seem to be enriched in B mares. Fatty acids that are readily available in the diet were more present in N mares, possibly because more elaborate FA are exported to the mammary gland for milk production. Nursing could thus modify the inflammatory response in the uterine environment at ~7.5 days post-ovulation and could affect reproductive efficiency in horses.

P613Cardiac magnetic resonance imaging derived left ventricular mechanical function in patients with atrial fibrillation and left atrial low voltage zones

Background

The relation of left atrial low voltage zones (LVZ) to left ventricular function in patients undergoing pulmonary vein isolation (PVI) is not known.

Objective

To explore the relationship of left atrial low voltage zones (LVZ) on left ventricular function in patients with atrial fibrillation.

Methods

From June to Nov. 2018, 107 (mean age 67y, 70 men, 73 persistent AF) consecutive patients with symptomatic AF underwent a PVI with LVZ mapping. Before PVI the left ventricular ejection fraction (EF) and stroke volume (SV) were measured by cardiac magnetic resonance imaging (CMR). From feature-tracking of CMR-cine images left ventricular global, systolic and diastolic longitudinal strains (GLS), circumferential strains (GCS) and radial strains (GRS) were calculated.

Results

Of 59 patients CMR scanning in sinus rhythm was performed, LVZ were present in 24 patients.

LVEF was significantly lower in patients with left atrial LVZ (62±9% vs. 55±15%) (p=0,03). Left ventricular stroke volume was significantly decreased by the extent of LVZ (94±23 vs. 72±21ml), (p=0,03).

The left ventricular diastolic strains during ventricular filling (caused by atrial contraction) of GLS (r=−0,52), GCS (r=−0,65) and GRS (r=−0,65) were highly signifcantly correlated to the occurence and extent of LVZ (each p<0,001 respectively).

The only systolic ventricular strain was GLS, which decreased (r=−0,3, p=0,03) by the occurance of atrial low voltage.

Conclusion

The active, atrial part of diastolic left ventricular filling properties is impaired by the occurrence and extent of left atrial LVZ. In patients with left atrial LVZ the left ventricular stroke volume and ejection fraction is decreased already in sinus rhythm. It seems possible that atrial mechanical dysfunction and presence of atrial low voltage maybe predicted by LV diastolic strain analysis.

P605Correlation of left atrial phasic transport function and arrhythmogenic substrate in patients with atrial fibrillation: cardiac magnetic resonance feature tracking and bipolar voltage mapping

Background

Bipolar voltage mapping is a widely accepted approach to identify areas of arrhythmogenic substrate in patients presenting for atrial fibrillation (AF) ablation.

However, until now little is known about the correlation of left atrial (LA) bipolar voltage distribution and LA transport function.

Purpose

To study the impact of LA low voltage zones (LVZ) on LA transport function.

Methods

107 consecutive patients presenting for ablation of symptomatic AF (34 paroxysmal AF, 73 persistent AF) were prospectively enrolled. Each patient underwent cardiac magnetic resonance imaging (CMR) within 24 hours prior to the ablation procedure. 59 patients were in sinus rhythm (SR) and 48 in AF. LA phasic indexed volumes (LAVi) and ejection fractions were calculated using biplane area length formula. In addition LA phasic strains and strain rates were analyzed using dedicated software (Figure 1A & B).

LA bipolar voltage mapping was performed prior to beginning of ablation in sinus rhythm using a 3-dimensional mapping system and LVZ were defined as areas of bipolar voltage <0.5mV.

Results

LVZ were present in 47 patients (23 in SR). The area of LVZ was 14.6cm2 (5.3–34.0). For patients in AF at the time of CMR only elevated minimal and maximal LAVi (p=0.001 and p=0.002 respectively) but no LA functional parameter was predictive for the occurrence of LVZ. In contrast for patients in SR all LA phasic volumes (endsystolic, pre atrial contraction and enddiastolic LAVi) and LA function parameters (passive, active and total ejection fraction (EF), reservoir, conduit and booster pump strains and strain rates) were predictive for the occurrence of LVZ. After clustered and pooled multivariate logistic regression only impaired booster pump strain rate was still predictive for occurrence of LVZ (OR 0.974, 95% CI 0.950–0.998, p=0.036).

In addition Pearson correlation analysis revealed a strong link between LA booster pump functional parameters and cm2 expansion of LVZ areas: LA active EF, LA booster pump strain and SR (r=−0.42, p=0.044; r=−0.47, p=0.024; r=−0.65, p=0.001 [Figure 1C] respectively).

Conclusion

For patients in SR LA transport function is closely linked to the occurrence of LA LVZ and outperforms LA volumetric measurements for the prediction of LA LVZ.

Furthermore LA booster pump function parameters show robust correlation to the extension of LA LVZ.

Early Infection Dynamics of Dichelobacter nodosus During an Ovine Experimental Footrot In Contact Infection

INTRODUCTION

Ovine footrot caused by Dichelobacter nodosus is a highly contagious and painful disease representing an economic as well as an animal welfare problem. In order to get more information on the infection dynamics, 26 lambs and 4 ewes enrolled in an in-contact infection trial were monitored over two weeks for the presence of D. nodosus-specific DNA. Two D. nodosus-positive ewes were housed together with 13 confirmed negative lambs. The control group consisted of another 13 lamb siblings and two confirmed D. nodosus-negative ewes. Every foot of all sheep was sampled seven times over the two weeks experiment period and subsequently analyzed for the presence of D. nodosus by quantitative real-time PCR. The control group was negative at the beginning and the end of the experiment and showed no clinical symptoms of footrot. The two positive ewes showed a high, but hundred fold differing level of virulent D. nodosus that remained constant over time with one of the ewes being also weakly positive for benign D. nodosus. All lambs of the infection group were positive for virulent D. nodosus at 14 days post infection (dpi). The first positive animals were observed on 3 dpi. The D. nodosus load remained at a low level and only increased in a few lambs at the end of the trial. Five of the contact lambs showed suspicious clincal signs (score 1-2) at 14 dpi corroborating the PCR results and indicating that the disease starts as early as two weeks after contact with positive sheep.

In vitro cultured bovine endometrial cells recognize embryonic sex

Endometrial cell co-culture (ECC) with single embryo may reflect endometrium responses in vivo. Bovine Day-6 in vitro-produced morulae were cultured until Day-8 in modified synthetic oviductal fluid (mSOF), or on the epithelial side of ECC. Expression of epithelial- and stromal-cell transcripts was analyzed by RT-PCR in ECC with one male (ME) or female embryo (FE). Concentrations of ARTEMIN (ARTN) and total protein were determined in epithelial cell-conditioned medium. ECCs yielded embryos with more cells in the inner cell mass than embryos cultured in mSOF. Embryos altered transcript expression only in epithelial cells, not in stromal ones. Thus, ME induced larger reductions than FE and controls (i.e., no embryos cultured) in hexose transporter solute carrier family 2 member 1 (SLC2A1) and member 5 (SLC2A5), connective tissue growth factor (CTGF), artemin (ARTN), and interferon alpha and beta receptors subunit IFNAR1 and IFNAR2. FE reduced SLC2A1 and SLC2A5, and increased ARTN expression with respect to controls. ME tended to reduce total protein concentration (P < 0.082) in ECC-conditioned medium, while ARTN protein and gene expressions strongly correlated (R > 0.90; P < 0.05) in the group of ME or FE, but not in controls (without embryo). Isolated male and female embryos may differentially release signaling factors that induce sexually dimorphic responses in endometrial cells.

Kinematic Bézier Maps

The kinematics of a robot with many degrees of freedom is a very complex function. Learning this function for a large workspace with a good precision requires a huge number of training samples, i.e., robot movements. In this paper, we introduce the Kinematic Bézier Map (KB-Map), a parameterizable model without the generality of other systems but whose structure readily incorporates some of the geometric constraints of a kinematic function. In this way, the number of training samples required is drastically reduced. Moreover, the simplicity of the model reduces learning to solving a linear least squares problem. Systematic experiments have been carried out showing the excellent interpolation and extrapolation capabilities of KB-Maps and their relatively low sensitivity to noise.

119 ENDOMETRIAL CO-CULTURE MODELS FOR THE IN VITRO INVESTIGATION OF EARLY EMBRYO - MATERNAL CROSSTALK IN CATTLE

Cellular and molecular changes in the endometrium during the preimplantation period are orchestrated by a complex network of molecules. The endometrium consists mainly of epithelial (EC) and stromal cells (SC) which produce a variety of active factors, such as prostaglandins (PG), in response to hormones and embryonic signals. However, it is unknown whether and how EC and SC influence each other in their reaction to these endo- and paracrine stimuli. To address this question, we measured the PG secretion of separately cultured EC and SC, and of EC+SC co-cultures in an insert system (0.2 µm membrane pore size) allowing exchange of secreted factors, but no direct contact between EC and SC. Bovine endometrial cells were isolated from cow uterus by a combination of mechanical and enzymatic procedures on Day 8 of the estrous cycle (ovarian morphology). Isolated EC and SC (90% purity) were cultured in DMEM/F12 containing 10% fetal bovine serum at 37�C in an atmosphere of 5% CO2 in air. PGE2 and PGF2α concentrations in media from separately cultured EC and SC or co-cultured EC+SC were measured by specific ELISAs after 24 h of stimulation with (i) 100 nm oxytocin (OXT); (ii) 100 ng mL–1 interferon tau (IFNT); or (iii) the respective solvent as non-stimulated control. EC responded to OXT stimulation with a decreased PGE2/PGF2α ratio, although the difference was not significant (PGE2/PGF2α ratio non-stimulated: 2.4 � 0.9; PGE2/PGF2α ratio stimulated: 1.5 � 0.8; P > 0.05 v. non-stimulated control, evaluated by t-test). No differences in the ratios of PGE2/PGF2α release into the medium were observed when comparing OXT-treated SC with non-treated SC. Incubating co-cultures of EC and SC with OXT resulted in a statistically significant, 2.5-fold decrease in the PGE2/PGF2α ratio as compared to non-stimulated cells (0.8 � 0.2 v. 2.0 � 0.7; P < 0.05; t-test). In contrast, IFNT stimulation of EC and SC co-cultures shifted PG secretion toward the pregnancy protective PGE2 (PGE2/PGF2α ratio non-stimulated: 0.99 � 0.44; PGE2/PGF2α ratio stimulated: 2.36 � 0.96; P < 0.05 v. non-stimulated control, by t-test). Conclusions: Our findings indicate that interactions between EC and SC regulate the responsiveness of the co-culture system to OXT and the pregnancy recognition molecule IFNT. We propose that co-culture of both cell types should be used for studying mechanisms of early embryo–maternal communication.

ProSAT2--Protein Structure Annotation Server

ProSAT2 is a server to facilitate interactive visualization of sequence-based, residue-specific annotations mapped onto 3D protein structures. As the successor of ProSAT (Protein Structure Annotation Tool), it includes its features for visualizing SwissProt and PROSITE functional annotations. Currently, the ProSAT2 server can perform automated mapping of information on variants and mutations from the UniProt KnowledgeBase and the BRENDA enzyme information system onto protein structures. It also accepts and maps user-prepared annotations. By means of an annotation selector, the user can interactively select and group residue-based information according to criteria such as whether a mutation affects enzyme activity. The visualization of the protein structures is based on the WebMol Java molecular viewer and permits simultaneous highlighting of annotated residues and viewing of the corresponding descriptive texts. ProSAT2 is available at http://projects.villa-bosch.de/mcm/database/prosat2/.

2 IDENTIFICATION OF GENES INDUCED BY THE CONCEPTUS IN THE BOVINE ENDOMETRIUM DURING THE PRE-IMPLANTATION PERIOD

Early embryonic development, implantation, and maintenance of a pregnancy are critically dependent on an intact embryo-maternal communication. So far, only few signals involved in this dialogue have been identified. In ruminants, interferon tau (IFN�) plays a key role in the process of maternal recognition of pregnancy by exhibiting antiluteolytic activity. Even though many experimental findings indicate a pivotal role of IFN� in the context of embryo-maternal communication in ruminants, a number of other systems may be involved. To identify genes induced in the bovine endometrium by the signaling of the embryo, a combination of subtracted cDNA libraries and cDNA array hybridization was applied. Monozygotic twin pairs (n = 5) were used as the biological model. Pregnancy was created in one twin by transferring two in vitro-produced embryos on Day 7 of the estrous cycle; the other twin received a sham embryo transfer. Pregnant and nonpregnant twins were slaughtered at Day 18; endometrial tissue samples were recovered and processed for transcriptome analysis as described (Bauersachs et al. 2005 J. Mol. Endocrinol. 34, 889-908). Screening of 4608 clones of two subtracted libraries revealed 90 different up-regulated genes and mRNAs, of which almost 50% are known to be stimulated by type I interferons. Among these interferon-stimulated genes, the ISG15 system is assumed to be of particular interest, and several components were studied in more detail using in situ hybridization. The pattern of mRNA expression suggests that modification of endometrial proteins through ISG15ylation plays a fundamental role during the pre-implantation period. A classification of the identified genes based on Gene Ontologies revealed the prevalence of genes involved in regulation of gene expression, cell communication, cell growth, cell differentiation, cell proliferation, and cell adhesion, and also the prevalence of genes with immune-related functions. These results underline the intense response of the endometrium to the presence of a conceptus, culminating in the preparation of the maternal environment for embryonic implantation. Further, for eleven selected genes the expression in the endometrium was quantified by the use of real-time RT-PCR. Overall, the results of quantitative RT-PCR and array hybridization correlated very well. To our knowledge this study provides the first holistic gene expression analysis of the bovine endometrium during the pre-implantation period. The results underline the importance of IFN� as an embryo-derived pregnancy recognition signal and depict the molecular mechanisms at the mRNA level underlying the intense embryo-maternal dialog taking place at Day 18 of gestation.

Acute pneumatosis cystoides intestinalis following allogeneic transplantation -- the surgeon's dilemma

Pneumatosis cystoides intestinalis (PCI) is still a poorly understood phenomenon, currently considered to result from primary mucosal insult from varying causes. We report a case of severe PCI in a patient with chronic GVHD after bone marrow transplantation (BMT) performed to treat secondary AML. Post BMT, the patient suffered acute intestinal and cutaneous GVHD, eventually developing intestinal and biopsy-proven cutaneous chronic GVHD, which necessitated continuous steroid therapy. Chronic pancreatitis associated with GVHD was diagnosed by explorative surgery in February 2000 on the basis of increasing epigastric discomfort, tumour marker (CA 125) increase and the CT finding of a suspicious mass in the pancreas. Readmission occurred in April 2000 for rapid onset of inferior abdominal pain with distinct peritoneal signs. Relaparotomy, deemed necessary on the grounds of both clinical and radiological findings, revealed marked PCI of the ascending and transverse colon and attached mesentery in an otherwise intact gastrointestinal tract. Post-operative reconvalescence was uneventful, with no clinical or radiological recurrence of PCI in the following 10 months. In the context of a review of the relevant literature, this case report illustrates the complex underlying pathophysiology, and difficulty in making a differential diagnosis and treating PCI.

Quality of diabetes care, diabetes knowledge and risk of severe hypoglycaemia one and four years after participation in a 5-day structured treatment and teaching programme for intensified insulin therapy

Intensification of insulin therapy in the Diabetes Control and Complications Trial led to an improvement in the quality of diabetes care, which was accompanied, however, by a threefold increase in the risk of severe hypoglycaemia. The present trial, a long-term evaluation of a structured 5-day treatment and teaching programme (DTTP) for intensified insulin therapy, was performed to clarify factors determining HbA1c, the incidence of severe hypoglycaemia, diabetes knowledge and quality of life. Ninety-four Type 1 diabetic patients were examined at baseline and 4 years after participation in a DTTP. Comparison of baseline data with measurements at the 4-year follow-up examination showed that relative HbA1c (= HbA1c/mean normal) improved (1.9 +/- 0.51 vs 1.55 +/- 0.3*, p < 0.001, *excluding 4 patients with diabetes manifestation at baseline) and that frequencies of daily insulin injections (3.73 +/- 1.23 vs 4.9 +/- 0.69*, p < 0.001) and weekly blood glucose self-tests (6.6 +/- 10.1 vs 25.5 +/- 8.7*, p < 0.001) increased, whereas the incidence of severe hypoglycaemia (intravenous glucose, glucagon injection) remained stable (0.19 vs 0.24, p = 0.48). Patients with less diabetes knowledge had higher HbA1c levels and a higher incidence of severe hypoglycaemia. In the group of patients with severe hypoglycaemia, certain crucial gaps in diabetes knowledge were identified concerning the effects of physical activity, nutrition and long-term complications of diabetes. In multivariate analysis. The most important factor associated with HbA1c was diabetes knowledge which, however, was not influenced by educational level or other factors. Interventions, such as the identification of psychosocial factors which may interact with diabetes knowledge, quality of life and successful self-management of diabetes by patients, are needed to improve the efficacy of DTTPs and to prevent severe side effects such as hypoglycaemia.

Long-term efficacy of a 5-day structured teaching and treatment programme for intensified conventional insulin therapy and risk for severe hypoglycemia

In the DCCT, intensification of insulin therapy led to a threefold increase in the risk of severe hypoglycemia (defined as the need for third party assistance). The reasons for this strong exponential relationship appears to be unclear to date. The present trial, a long-term evaluation of a 5-day structured teaching and treatment programme (5-DTTP) for intensified conventional insulin therapy (ICT), was performed to elucidate factors determining HbA1c and the incidence of severe hypoglycemia. A total of 71 patients were examined at baseline and 45.5 +/- 4.2 months following participation in a 5-DTTP. Comparing the data at follow-up examination with baseline measurements. HbA1c improved (8.52 +/- 2.29% vs. 8.0 +/- 1.43%, P = 0.04), the frequency of daily insulin injections (3.1 +/- 1.6 vs. 4.8 +/- 0.8, P < 0.001) and weekly blood-glucose self-tests (5.2 +/- 8.9 vs. 25.5 +/- 9.6, P < 0.001) increased, and the incidence of severe hypoglycemia (glucose i.v., glucagon injection) remained stable (0.18 vs. 0.17, P = 0.99). But, comparing the 21 patients who suffered from severe hypoglycemia during the follow-up period with the 50 patients without hypoglycemia, no differences between the two groups were found with respect to metabolic control (7.70 +/- 1.48% vs. 8.21 +/- 1.43%, P = 0.17), quality of life or treatment satisfaction. However differences arose with respect to diabetes knowledge. In the group of 21 patients with severe hypoglycemia we identified certain crucial gaps in diabetes knowledge: insulin self-adjustment; dietary aspects; hypo- and hyperglycemia. Performing multiple regression analysis, strong correlations were found between HbA1c and diabetes knowledge (r = -0.58. P = 0.002 for 50 patients without hypoglycemia and r = -0.63, P = 0.05 for 21 patients with hypoglycemia). In the total group, the most important factors determining HbA1c, were diabetes knowledge (r = -0.055, P = 0.007) and daily insulin dosage/kg body weight (r = 2.13, P = 0.0008, R2 = 0.26). Intervention like education of patients on a continuous basis and modifications of the DTTP's with more information and training in the recognition and treatment of hypoglycemic episodes seems to be essential to prevent hypoglycemia and to improve the efficacy of DTTP's over longer periods of time.

Serum interleukin 2-receptor levels in uveitis

This study reports on serum interleukin 2-receptor (IL-2R) levels in uveitis patients. IL-2R is the mediator protein of interleukin 2 (IL-2), a mitogenetic cytokine of primarily immune cell interaction. Stimulated T-cells readily express IL-2R on their cell surface and release a soluble form into serum. The measurement of IL-2R serum levels was performed using a monoclonal antibody based ELISA with age and sex matched healthy blood donors serving as the control group. The increase of IL-2R serum levels in patients affected by heterochromic cyclitis Fuchs (HCF) and a small group of children with chronic anterior uveitis affected by juvenile rheumatoid arthritis (JRA) was statistically highly significant, when compared to the control group (n = 84, alpha = 0.01). Serum levels of patients with intermediate uveitis (IU), patients with HLA-B27 positive acute anterior uveitis (AAU) and patients with HLA-B27 negative AAU did not differ significantly from the controls.