Efficacy of cryoballoon ablation for atrial fibrillation in a geriatric population

Background

Cryoballoon pulmonary vein isolation (cryoPVI) is well-established for paroxysmal atrial fibrillation (AF) but its value in persistent AF is less clear. In particular, its efficacy in cardiogeriatric patients (≥75 years) is unknown. Age represents an important modifier of AF progression and is a risk-factor for AF recurrence.

Methods

We conducted a prospective, single-center study to analyze efficacy and safety of cryoPVI in cardiogeriatric patients stratified according to AF entity. Maximum follow-up was 24 months. Efficacy endpoint was symptomatic AF relapse after 90-day blanking period.

Results

We included 668 patients. Of these 218 were ≥75 years old. Paroxysmal AF was present in 400 and persistent AF in 268 patients. By means of cox-regression analysis we found age as the only independent factor influencing AF recurrence in the overall cohort (P=0.034). This effect was carried by patients with persistent AF (P=0.006). At 24 months, the recurrence rate was highest in patients with persistent AF and age ≥75 years (57%; P=0.0004).

Conclusion

Cardiogeriatric patients with persistent AF undergoing cryoPVI had higher rates of AF recurrence compared to elderly patients with paroxysmal AF or younger patients. Against this background we assume, that pulmonary-vein dependent AF may be less frequently encountered among patients ≥75 years with persistent AF.

Funding Acknowledgement

Type of funding sources: None.

Chronic insulin resistance deteriorates cardiac mitochondrial quality control in a mouse model of SEC-NAFLD-IR

Background

Insulin resistance and nonalcoholic fatty liver disease (NAFLD) both relate to cardiovascular mortality. Using a mouse model of chronic lipid overload and secondary-NAFLD-induced insulin resistance (SEC-NAFLD-IR), we recently deciphered that SEC-NAFLD-IR already at young age provoked myocardial lipotoxicity with reduced mitochondrial efficiency and increased vulnerability to cardiac ischemia. However, long-term consequences of SEC-NAFLD-IR remain elusive.

Purpose

Here we aimed to elucidate the impact of long-term SEC-NAFLD-IR on multiple mitochondrial quality control (mQC) mechanisms in the heart and its consequences for cardiac function.

Methods

We studied 36 SEC-NAFLD-IR mice (72-week-old). For mechanistic experiments, we applied palmitate-induced insulin resistant murine HL-1 cells. Cardiac mitochondrial dynamics were measured via quantification of mitochondrial morphology and expression of mitochondrial fusion and fission factors (Opa1, Drp1, Fis1, Mfn 1 & 2). Mitophagy level was evaluated via immunofluorescence and protein expression of key mitophagy-related genes (Parkin, NIX, LC3). Mitochondrial biogenesis and mass were examined via quantitation of PGC-1α expression, mtDNA and citrate synthase activity.

Results

72-week-old SEC-NAFLD-IR mice exhibited 21% (p=0.001) and 32% (p<0.001) higher body weight and heart weight compared with controls. Along with elevated oxidative stress, hepatic lipid accumulation and inflammation, 6h-fasted SEC-NAFLD-IR mice were characterized by increased plasma glucose, insulin and cholesterol. SEC-NAFLD-IR mice displayed a cardiac phenotype with 21% higher left ventricular mass (normalized to body weight, p<0.001) and 6% lower ejection fraction compared to controls (73.5% SEM 0.90 vs 69.4% SEM 1.65, p=0.04). We found several advantageous mQC mechanisms suppressed in aged SEC-NAFLD-IR mice including long form OPA1-mediated mitochondrial fusion, Parkin- and NIX-mediated mitophagy. Likewise, mitochondrial biogenesis was suppressed in the aged insulin-resistant heart, which was connected to a 65% downregulation of PGC-1α1 expression (p=0.01). Interestingly, downregulation of cardiac PGC-1α1 in aged SEC-NAFLD-IR mice coincided with upregulation of PARIS, indicating the crucial participation of the Parkin/PARIS pathway in mQC of the insulin-resistant heart. In addition, induction of insulin resistance in murine HL-1 cardiomyocytes also led to increased mitochondrial fragmentation and decreased PGC-1α1 expression.

Conclusion

This study demonstrated that regulation of mitochondrial network and turnover is hampered by SEC-NAFLD-IR in the hearts of aged mice, which may contribute to hypertrophy and cardiac dysfunction in insulin resistance.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Collaborative Research Centre 1116 (German Research Foundation)

Cryoballoon ablation in obese patients: it is worth it, let us work it

Background

Obesity is a major risk factor for atrial fibrillation (AF) development and of increasing prevalence in western countries. Safe and effective treatment methods for obese patients with AF are therefore important. Cryoballoon pulmonary vein isolation (CryoPVI) is a well-established therapy for symptomatic AF but data regarding obese patients are lacking.

Objective

To prospectively compare efficacy, safety and periprocedural parameters of CPVI in normal-weight and obese (Body-Mass-Index (BMI) ≥30kg/m2) patients.

Methods

We analyzed consecutive patients who underwent CryoPVI in a single-center cohort between 2018 and 2020. CryoPVI was performed in a standardized fashion. Follow-up was performed at 3, 6, 12, 18 and 24 months after CryoPVI. Endpoints were: symptomatic AF relapse for efficacy and bleeding, phrenic nerve injury, stroke or death for safety. Periprocedureal parameters were observed.

Results

We included 464 patients into the analysis, of these 331 patients had normal BMI (mean BMI 25.5±2.8 kg/m2, age 70±10 years, CHA2DS2-VASc 2.7±1.5, 56% male) while 133 patients (28.7%) suffered from obesity (mean BMI 33.2 kg/m2, age 67±9 years, CHA2DS2-VASc 2.7±1.4, 55% male). After 24 months freedom from AF relapse was similar for normal-weight and obese patients (58.8% vs. 61%, P=0.78, Figure 1A). Primary safety end point occurred in form of pericardial effusion or phrenic nerve injury in five patients with normal BMI (1.5%) and none obesity group. No deaths or strokes were observed in either group. Compared with control left-atrial dwell time (39.7±14.6 min vs. 44.8±18.7 min, P=0.002, fluoroscopy time (7.3±3.6 min vs. 8.3±4.1 min, P=0.013), contrast dye use (64.6±34.3 ml vs. 74.5±39.5 ml, P=0.009), and radiation dose (224.8±164.2 cGy·cm2 vs. 533.3±655.6 cGy·cm2, P<0.001) were significantly higher in obese patients (Figure 1B–E).

Conclusion

CryoPVI is safe and effective in obese patients but achievement of PVI is associated with longer procedure times, higher radiation exposure and contrast dye use.

Funding Acknowledgement

Type of funding sources: None.

Regional analysis of inflammation and contractile function in reperfused acute myocardial infarction by in vivo 19F cardiovascular magnetic resonance in pigs

Inflammatory cell infiltration is central to healing after acute myocardial infarction (AMI). The relation of regional inflammation to edema, infarct size (IS), microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and regional and global LV function is not clear. Here we noninvasively characterized regional inflammation and contractile function in reperfused AMI in pigs using fluorine (¹⁹F) cardiovascular magnetic resonance (CMR). Adult anesthetized pigs underwent left anterior descending coronary artery instrumentation with either 90 min occlusion (n = 17) or without occlusion (sham, n = 5). After 3 days, in surviving animals a perfluorooctyl bromide nanoemulsion was infused intravenously to label monocytes/macrophages. At day 6, in vivo ¹H-CMR was performed with cine, T2 and T2* weighted imaging, T2 and T1 mapping, perfusion and late gadolinium enhancement followed by ¹⁹F-CMR. Pigs were sacrificed for subsequent ex vivo scans and histology. Edema extent was 35 ± 8% and IS was 22 ± 6% of LV mass. Six of ten surviving AMI animals displayed both MVO and IMH (3.3 ± 1.6% and 1.9 ± 0.8% of LV mass). The ¹⁹F signal, reflecting the presence and density of monocytes/macrophages, was consistently smaller than edema volume or IS and not apparent in remote areas. The ¹⁹F signal-to-noise ratio (SNR) > 8 in the infarct border zone was associated with impaired remote systolic wall thickening. A whole heart value of ¹⁹F integral (¹⁹F SNR × milliliter) > 200 was related to initial LV remodeling independently of edema, IS, MVO, and IMH. Thus, ¹⁹F-CMR quantitatively characterizes regional inflammation after AMI and its relation to edema, IS, MVO, IMH and regional and global LV function and remodeling.

Electrical cardioversion during cryoballoon pulmonary vein isolation predicts long-term ablation success in persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Cryoballoon pulmonary vein isolation (cryoPVI) is an established option for treatment of atrial fibrillation (AF) but many periprocedural events influencing long-term outcome and procedural safety of ablation remain unclear. In radiofrequency ablation studies, failure to convert to sinus rhythm and electrical cardioversion (ECV) have been associated with increased recurrence rates. In this context, the influence of ECV during cryoPVI on long-term ablation efficacy is unclear.

Objective

A prospective comparison of AF recurrence after cryoballoon ablation in patients who were in AF or atrial tachycardia at the beginning of cryoPVI requiring ECV during procedure with patients who underwent ablation therapy without ECV.

Methods

We analyzed consecutive patients who underwent cryoPVI in a single-center cohort between 2018 and 2020. Follow-up was performed at 3, 6, 12, 18 and 24 months after ablation. Primary endpoints were: symptomatic AF recurrence for efficacy and bleeding, phrenic nerve injury, stroke or death for safety.

Results

472 consecutive patients who underwent ablation in a single-center cohort were analysed. Mean follow-up time was 15 months. In 195 patients (74 paroxysmal AF vs. 121 persistent AF, age 69 ± 10 years, 57% male, CHA2DS2-VASc 2.6 ± 1.4) at least one ECV was performed following ablation, while no cardioversion was necessary in 277 patients (214 paroxysmal AF vs. 63 persistent AF, age 69 ± 10 years, 55% male, CHA2DS2-VASc 2.7 ± 1.5). After 24 months, primary efficacy endpoint occurrence was significantly higher in persistent AF requiring cardioversion during procedure than for persistent AF without cardioversion and paroxysmal AF with/ without cardioversion (56.1 % vs. 31.2%, 33.6%, 32.9%, log-rank p = 0.009, figure). Primary safety endpoint occurred in form of pericardial effusion or transient phrenic nerve injury in two patients in cardioversion group (1.0%) and three patients without cardioversion (1.1%). No deaths or strokes were observed in either group. Total procedure duration (55.6 ± 17min vs. 57.7 ± 15.9min, P = 0.17) and left-atrial dwell time (39.7 ± 14.9min vs. 42 ± 15.6min, P = 0.11) were similar.

Conclusion

In patients with persistent AF, the need for ECV during cryoPVI predicts a poorer long-term outcome during 2-year follow-up. Future studies should focus on this specific patient population. Abstract Figure.

Cryoballoon pulmonary-vein isolation for atrial fibrillation with heart failure: results from a single-center cohort

Background

Atrial fibrillation (AF) and heart failure (HF) are of growing prevalence and increasing mortality. Radiofrequency ablation is safe and effective for patients with AF and HF. Prognosis might be improved in patients treated. However, there is no prospective trial investigating efficacy and safety of cryoballon ablation in patients with AF and HF.

Objective

To prospectively compare cryoballoon ablation in patients with and without HF (defined as LVEF ≤40%) in terms of safety and efficacy.

Methods

Ongoing POLAR-HF trial is a prospective, investigator-initiated, single-center, non-inferiority, open-label study. We analyzed 244 consecutive patients who underwent cryoballoon ablation. Of these 217 had normal LVEF (age 68.1±9.6 years, CHA2DS2-VASc Score 2.5±1.3, 55.3% male) while 27 patients (11%) suffered from HF (age 70.4±8.6 years, CHA2DS2-VASc Score 3±1.2, 70.4% male). Follow-up was performed at 3, 6 and 12 months after ablation. Kaplan-Meier method was used to calculate 12-month event-rate estimates. Log-Rank Test to estimate hazard ratios in the primary analysis. Endpoints were: symptomatic AF relapse for efficacy and bleeding, stroke or death for safety.

Results

Analysis showed no difference in AF-free survival rate between patients with and without HF (81% vs. 76.3%, Log-Rank-Test P=0.81, Figure). Primary safety end point occurred in 5 patients with normal LVEF (2.3%) and none in the HF-group. No deaths were observed.

Conclusion

Results of POLAR-HF indicate that cryoballoon ablation is an effective ablation method for patients suffering from AF and HF.

Event-Free Survival (Efficacy Endpoint)

Funding Acknowledgement

Type of funding source: None

Muscarinic receptors promote pacemaker fate at the expense of secondary conduction system tissue in zebrafish

Deterioration or inborn malformations of the cardiac conduction system (CCS) interfere with proper impulse propagation in the heart and may lead to sudden cardiac death or heart failure. Patients afflicted with arrhythmia depend on antiarrhythmic medication or invasive therapy, such as pacemaker implantation. An ideal way to treat these patients would be CCS tissue restoration. This, however, requires precise knowledge regarding the molecular mechanisms underlying CCS development. Here, we aimed to identify regulators of CCS development. We performed a compound screen in zebrafish embryos and identified tolterodine, a muscarinic receptor antagonist, as a modifier of CCS development. Tolterodine provoked a lower heart rate, pericardiac edema, and arrhythmia. Blockade of muscarinic M3, but not M2, receptors induced transcriptional changes leading to amplification of sinoatrial cells and loss of atrioventricular identity. Transcriptome data from an engineered human heart muscle model provided additional evidence for the contribution of muscarinic M3 receptors during cardiac progenitor specification and differentiation. Taken together, we found that muscarinic M3 receptors control the CCS already before the heart becomes innervated. Our data indicate that muscarinic receptors maintain a delicate balance between the developing sinoatrial node and the atrioventricular canal, which is probably required to prevent the development of arrhythmia.

Evaluation of choroidal substructure perfusion in patients affected by systemic sclerosis: an optical coherence tomography angiography study

Objective: Vasculopathy in systemic sclerosis (SSc) is characterized by the obliteration of arterioles and a reduced capillary density in various tissues. In SSc, atrophic alterations of the choroid have been suggested based on morphological data acquired by optical coherence tomography (OCT). In this study, we aimed to assess the choroid in eyes of patients with SSc from a microcirculatory, dynamic point of view by adding optical coherence tomography angiography (OCTA) to the diagnostic spectrum.Method: SSc patients were enrolled, and age- and gender-matched healthy subjects were used as controls. In addition to basic ophthalmological and rheumatological examinations, individuals underwent enhanced-depth imaging OCT and OCTA. Subfoveal thicknesses of the choroid as well as all three choroidal vascular sublayers were measured and submacular perfusion values were evaluated.Results: In total, 12 patients with SSc and 12 matched controls were included. The median age of participants was 64 years. Submacular perfusion was significantly lower in the choriocapillaris (Δ = 0.72%; p = 0.045), Sattler's layer (Δ = 2.87%; p = 0.001), and Haller's layer (Δ = 2.69%; p = 0.018) of SSc patients compared to controls. Subfoveal thicknesses of Sattler's layer (Δ = 15 µm; p = 0.026) and Haller's layer (Δ = 41 µm; p = 0.045) were also significantly smaller in the SSc group.Conclusion: Choroidal microcirculation is impaired in SSc, even in patients without ophthalmological symptoms. Choroidal OCT and OCTA may offer additional biomarkers for SSc activity.

The Wnt inhibitor Dkk1 is required for maintaining the normal cardiac differentiation program in Xenopus laevis

Wnt proteins can activate different intracellular signaling pathways. These pathways need to be tightly regulated for proper cardiogenesis. The canonical Wnt/β-catenin inhibitor Dkk1 has been shown to be sufficient to trigger cardiogenesis in gain-of-function experiments performed in multiple model systems. Loss-of-function studies however did not reveal any fundamental function for Dkk1 during cardiogenesis. Using Xenopus laevis as a model we here show for the first time that Dkk1 is required for proper differentiation of cardiomyocytes, whereas specification of cardiomyocytes remains unaffected in absence of Dkk1. This effect is at least in part mediated through regulation of non-canonical Wnt signaling via Wnt11. In line with these observations we also found that Isl1, a critical regulator for specification of the common cardiac progenitor cell (CPC) population, acts upstream of Dkk1.

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Dkk1 is required for cardiac development in Xenopus laevis.

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The Wnt inhibitor Dkk1 acts downstream of Isl1 during cardiac development in vivo.

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Loss of Dkk1 has no impact on cardiac specification in Xenopus.

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Normal cardiac differentiation is impaired upon Dkk1 inhibition in Xenopus.

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Dkk1 regulates canonical Wnt/β-catenin signaling during Xenopus cardiogenesis.

The CapZ interacting protein Rcsd1 is required for cardiogenesis downstream of Wnt11a in Xenopus laevis

Wnt proteins are critical for embryonic cardiogenesis and cardiomyogenesis by regulating different intracellular signalling pathways. Whereas canonical Wnt/β-catenin signalling is required for mesoderm induction and proliferation of cardiac progenitor cells, β-catenin independent, non-canonical Wnt signalling regulates cardiac specification and terminal differentiation. Although the diverse cardiac malformations associated with the loss of non-canonical Wnt11 in mice such as outflow tract (OFT) defects, reduced ventricular trabeculation, myofibrillar disorganization and reduced cardiac marker gene expression are well described, the underlying molecular mechanisms are still not completely understood. Here we aimed to further characterize Wnt11 mediated signal transduction during vertebrate cardiogenesis. Using Xenopus as a model system, we show by loss of function and corresponding rescue experiments that the non-canonical Wnt signalling mediator Rcsd1 is required downstream of Wnt11 for ventricular trabeculation, terminal differentiation of cardiomyocytes and cardiac morphogenesis. We here place Rcsd1 downstream of Wnt11 during cardiac development thereby providing a novel mechanism for how non-canonical Wnt signalling regulates vertebrate cardiogenesis.

In situ luminescence analysis: a new light on monitoring calcium phosphate phase transitions

In situ luminescence measurements allow monitoring the phase transitions of biologically relevant calcium phosphates with high sensitivity, independent of synchrotron radiation.

Transient binding accounts for apparent violation of the generalized Stokes-Einstein relation in crowded protein solutions

The effect of high concentration, also referred to as crowding conditions, on Brownian motion is of central relevance for the understanding of the physical, chemical and biological properties of proteins in their native environment. Specifically, the simple inverse relationship between the translational diffusion coefficient and the macroscopic solution viscosity as predicted by the generalized Stokes-Einstein (GSE) relation has been the subject of many studies, yet a consensus on its applicability has not been reached. Here, we use isotope-filtered pulsed-field gradient NMR to separately assess the μm-scale diffusivity of two proteins, BSA and an SH3 domain, in mixtures as well as single-protein solutions, and demonstrate that transient binding can account for an apparent violation of the GSE relation. Whereas GSE behavior applies for the single-protein solutions, it does not hold for the protein mixtures. Transient binding behavior in the concentrated mixtures is evidenced by calorimetric experiments and by a significantly increased apparent activation energy of diffusion. In contrast, the temperature dependence of the viscosity, as well as of the diffusivity in single-component solutions, is always dominated by the flow activation energy of pure water. As a practically relevant second result, we further show that, for high protein concentrations, the diffusion of small molecules such as dioxane or water is not generally a suitable probe for the viscosity experienced by the diffusing proteins.

A phospho-dependent mechanism involving NCoR and KMT2D controls a permissive chromatin state at Notch target genes

The transcriptional shift from repression to activation of target genes is crucial for the fidelity of Notch responses through incompletely understood mechanisms that likely involve chromatin-based control. To activate silenced genes, repressive chromatin marks are removed and active marks must be acquired. Histone H3 lysine-4 (H3K4) demethylases are key chromatin modifiers that establish the repressive chromatin state at Notch target genes. However, the counteracting histone methyltransferase required for the active chromatin state remained elusive. Here, we show that the RBP-J interacting factor SHARP is not only able to interact with the NCoR corepressor complex, but also with the H3K4 methyltransferase KMT2D coactivator complex. KMT2D and NCoR compete for the C-terminal SPOC-domain of SHARP. We reveal that the SPOC-domain exclusively binds to phosphorylated NCoR. The balance between NCoR and KMT2D binding is shifted upon mutating the phosphorylation sites of NCoR or upon inhibition of the NCoR kinase CK2β. Furthermore, we show that the homologs of SHARP and KMT2D in Drosophila also physically interact and control Notch-mediated functions in vivo. Together, our findings reveal how signaling can fine-tune a committed chromatin state by phosphorylation of a pivotal chromatin-modifier.

An Epha4/Sipa1l3/Wnt pathway regulates eye development and lens maturation

The signal-induced proliferation associated family of proteins comprises four members, SIPA1 and SIPA1L1-1L3. Mutations of the human SIPA1L3 gene result in congenital cataracts. In Xenopus, loss of Sipa1l3 function led to a severe eye phenotype that was distinguished by smaller eyes and lenses including lens fiber cell maturation defects. We found a direct interaction between Sipa1l3 and Epha4, building a functional platform for proper ocular development. Epha4 deficiency phenocopied loss of Sipa1l3 and rescue experiments demonstrated that Epha4 acts up-stream of Sipa1l3 during eye development. Both, Sipa1l3 and Epha4 are required for early eye specification. The ocular phenotype, upon loss of either Epha4 or Sipa1l3, was partially mediated by rax. We demonstrated that canonical Wnt signaling is inhibited downstream of Epha4/Sipa1l3 during normal eye development. Depletion of either Sipa1l3 or Epha4 resulted in an up-regulation of axin2 expression, a direct Wnt/β-catenin target gene. In line with this, Sipa1l3 or Epha4 depletion could be rescued by blocking Wnt/β-catenin or activating non-canonical Wnt signaling. We therefore conclude that this pathomechanism prevents proper eye development and maturation of lens fiber cells resulting in congenital cataracts.

Lentivirus-induced 'Smart' dendritic cells: Pharmacodynamics and GMP-compliant production for immunotherapy against TRP2-positive melanoma

Monocyte-derived conventional dendritic cells (ConvDCs) loaded with melanoma antigens showed modest responses in clinical trials. Efficacy studies were hampered by difficulties in ConvDC manufacturing and low potency. Overcoming these issues, we demonstrated higher potency of lentiviral vector (LV)-programmed DCs. Monocytes were directly induced to self-differentiate into DCs (SmartDC-TRP2) upon transduction with a tricistronic LV encoding for cytokines (granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4)) and a melanoma antigen (tyrosinase-related protein 2 (TRP2)). Here, SmartDC-TRP2 generated with monocytes from five advanced melanoma patients were tested in autologous DC:T cell stimulation assays, validating the activation of functional TRP2-specific cytotoxic T lymphocytes (CTLs) for all patients. We described methods compliant to good manufacturing practices (GMP) to produce LV and SmartDC-TRP2. Feasibility of monocyte transduction in a bag system and cryopreservation following a 24-h standard operating procedure were achieved. After thawing, 50% of the initial monocyte input was recovered and SmartDC-TRP2 self-differentiated in vitro, showing uniform expression of DC markers, detectable LV copies and a polyclonal LV integration pattern not biased to oncogenic loci. GMP-grade SmartDC-TRP2 expanded TRP2-specific autologous CTLs in vitro. These results demonstrated a simpler GMP-compliant method of manufacturing an effective individualized DC vaccine. Such DC vaccine, when in combination with checkpoint inhibition therapies, might provide higher specificity against melanoma.

[Early Selection of At-risk Patients for Type 2 Diabetes in the GP Surgery by Medical Assistants - A Feasibility Study]

Objective: We investigated whether patients who belong to the high risk group to develop type-2 diabetes can be identified by medical assistants (MFA) in the everyday routine of the general practice by means of a few characteristics. The effectiveness of a diabetes-risk screening could be improved by a selective approach to patients who are at risk. Method: As part of the feasibility study 'SeRiFIN', patients who were between 20 and 50 years old and/or had a positive family history were approached by trained MFA in 6 general practices. To determine the risk of diabetes, the selected patients should complete the FINDRISK questionnaire. In the 5 control practices, patients of the same age group without known type 2 diabetes, were also asked to perform a risk analysis with the help of the FINDRISK questionnaire. Results: 916 FINDRISK questionnaires were evaluated. In the selection group, 62% of surveyed patients indicated that there were cases of diabetes in the family. In 86% of patients the waist circumference was increased. A 30% risk or higher to develop type 2 diabetes in the next ten years was found in 22% of the addressed patients. In the unselected group only 7% of patients had a risk that had to be investigated. In addition there was a significant difference in the eating behaviour and the level of daily exercise between the selection an the control group. The training of MFA as well as the implementation of the intervention were well received and considered feasible to conduct in addition to the routine work of MFA. Furthermore MFA expressed their astonishment at the effectiveness of this pre-selection. Conclusion: After training MFA recognise patients at risk for type 2 diabetes reliably in their everyday practice routine. The targeted approach to patients at risk can be delegated to the MFA. Thus, the time resources of general practitioners can be more effectively used for prevention treatment. Especially cardiovascular risk patients should benefit from the earliest possible identification and intervention.

Evolution of the gut microbiota and the influence of diet

Diet is a major force that shapes the composition and activity of the gut microbiota. This is evident from alterations in gut microbiota composition after weaning or drastic dietary changes. Owing to the complexity of the microbiota, interactions of intestinal bacteria with the host are difficult to study. Gnotobiotic animal models offer the opportunity to reduce the complexity and the interindividual variability of the intestinal microbiota. Germ-free animals were associated with a simplified microbial community consisting of eight bacterial species, that are found in the human gut. These microbes were selected because their genome sequences are available, and they mimic to some extent the metabolic activity of the human gut microbiota. The microbiota responded to dietary modifications by changes in the relative proportions of the community members. This model offers the chance to better define the role of intestinal bacteria in obesity development, but little is known on how diet affects intestinal bacteria at the cellular level. Mice monoassociated with Escherichia coli were used as a simplified model to investigate the influence of dietary factors on bacterial protein expression in the intestine. The mice were fed three different diets: a carbohydrate (lactose)-rich diet, a protein-rich diet and a diet rich in starch. The lactose-rich diet led to an induction of proteins involved in E. coli's oxidative stress response (Fur, AhpF, Dps). The corresponding genes are under control of the OxyR transcriptional regulator which is activated by oxidative stress. Further experiments demonstrated that osmotic stress exerted by various carbohydrates leads to an upregulation of proteins belonging to the oxyR regulon. The data suggest that the upregulated proteins enable intestinal E. coli to better cope with diet-induced osmotic stress. These examples demonstrate that gnotobiotic animal models are a valuable tool for studying diet-induced changes at the community and the cell level.

Practical experiences in application of hair fatty acid ethyl esters and ethyl glucuronide for detection of chronic alcohol abuse in forensic cases

This article presents results from 1872 hair samples, which were analyzed for fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG). The results were evaluated in the context of self-reported drinking behavior, the use of hair cosmetics, the gender of the sample donors and hair sample length. For comparison, CDT and GGT in serum were available in 477 and 454 cases, respectively. A number of alcohol abstainers or low moderate drinkers and excessive drinkers were selected for assessment of cut-offs for FAEEs in the proximal 6cm hair segments and for EtG in the proximal 3cm hair segments. Cut-off values were assessed by ROC analysis. It was found that the cut-offs of 1.0ng/mg FAEE and 30pg/mg EtG presently used for excessive drinking lead to a low portion of false positives (4% and 3% respectively) but to a higher portion of false negatives (23% and 25% respectively). Comparison of the mean and medium concentrations in samples without any reported hair cosmetics (N=1079) and in samples with reported use of hair spray (N=79) showed an increase by the factor of about two for FAEE but no significant difference for EtG. Mean values of EtG were decreased by 80% in bleached samples (N=164) and by 63% in dyed samples (N=96). There was no significant effect of bleaching and dyeing on FAEE. Hair gel and hair wax, oil or grease showed no significant effect on both FAEE and EtG. With respect to gender and investigated hair length ambiguous results were obtained because of major differences in the compared subpopulations of male with higher alcohol consumption and mainly shorter hair, and less drinking female with longer hair. For excessive drinkers FAEEs in the 0-6cm hair segment and EtG in the 0-3cm segment decreased with increasing time of reported abstinence before sample collection. These drinkers attain the level of teetotalers only after more than 10 months of abstinence. In comparison to scalp hair, FAEEs recovered from armpit hair and leg hair were lower and from chest hair were higher. EtG in armpit hair was lower and in leg hair higher than in scalp hair. It is concluded that the combined use of FAEE and EtG essentially increases the accuracy of interpretation since both markers complement each other by a different sensitivity to sources of error.

Langzeitergebnisse nach Handgelenkdenervation bei fortgeschrittenem karpalem Kollaps (SLAC-/SNAC-Wrist Stadium II und III)

INTRODUCTION

Mid-carpal arthrodesis, proximal row carpectomy and wrist arthrodesis are commonly cited in the literature as successful methods for pain reduction in patients with advanced carpal collapse (SLAC-/SNAC-wrist stages II and III). However, studies of isolated wrist denervation in patients who still possess good wrist mobility appear to be an underrepresented topic, especially in the German literature.

PURPOSE

Based on follow-up results, it was possible to establish to what extent patients benefit long-term from isolated wrist denervation, whilst retaining wrist mobility.

PATIENTS AND METHOD

46 patients (6 female, 40 male) with a diagnosis of SLAC-wrist (n = 10) or SNAC-wrist (n = 36) stages II and III underwent wrist denervation of points 1 - 4, 6, 9 and 10 according to Wilhelm, between 1990 and 2001, following a positive denervation test. No previous reconstructive wrist surgery had been performed on any of the patients, whose average age at the time of denervation was 47 years. In 29 cases the dominant hand was affected, and in 22 cases the symptoms could be classified as post-traumatic. Post-operative follow-up was possible in 32 out of 46 cases (70 %), and occurred on average 6.3 years post-denervation (range 2.3 to 14 years).

RESULTS

Twelve out of 32 patients (32 %) reported to be pain-free at follow-up, with a post-operative period ranging from 2.3 to 11.4 years (average 6.2 years). Six patients (18.75 %) continued to experience pain when load-bearing, which remained unchanged over a period of several years. Three patients (9 %) reported pain after stress, five patients (15.6 %) the recurrence of severe pain, which developed on average 3.8 years post-operatively. Two patients (6.25 %) experienced no analgesic benefits following wrist denervation, and four patients underwent wrist arthrodesis on average 13.5 months post-denervation, due to remaining or additional symptoms. Nineteen out of 32 patients subjectively reported a significant improvement following wrist denervation. Reassessment of range of movement post-denervation showed a reduction of 8.1 % in wrist extension/flexion, and 20 % in radio/ulna-abduction. Compared to the unaffected side, this represented an average loss of 28 % wrist extension/flexion, and 33.5 % radio/ulna-abduction. An average 51 % increase in hand strength could be shown at follow-up, leaving an average 30 % deficit compared to the unaffected hand. Evaluation of these results using the Krimmer score showed a good - very good outcome in 20 of the 32 patients (62.5 %); six patients were found to have a satisfactory outcome, and six patients a poor outcome. Subjective measures of pain (obtained using visual analogue scales) showed a reduction from 68.13 pre-operatively to 25.63 post-operatively. The DASH assessment (parts A and B) attained an average post-operative value of 17.1.

CONCLUSION

Denervation of the wrist in patients with SLAC-/SNAC-wrist stages II and III can achieve a long-term elimination or reduction of pain, whilst improving hand strength, and having only a minimal impact on wrist range of movement. Wrist denervation should therefore be given preference over wrist arthrodesis, midcarpal arthrodesis or proximal row carpectomy in patients with good wrist mobility.