Taking the next step forward - Diagnosing inherited infantile cholestatic disorders with next generation sequencing.

Identifying rare genetic forms of infantile cholestasis is challenging due to their similar clinical presentation and their diverse etiology. After exclusion of common non-genetic causes a huge list of rare differential diagnosis remains to be solved. More than 90 genes are associated with monogenic forms of infantile cholestasis, thus preventing routine genetic workup by Sanger sequencing. Here we demonstrate a next generation sequencing approach to discover the underlying cause in clinically well characterized patients in whom common causes of infantile cholestasis have been excluded. After validation of the analytical sensitivity massive parallel sequencing was performed for 93 genes in six prospectively studied patients. Six novel mutations (PKHD1: p.Thr777Met, p.Tyr2260Cys; ABCB11: p.Val1112Phe, c.611+1G > A, p.Gly628Trpfs*3 and NPC1: p.Glu391Lys) and two known pathogenic mutations were detected proving our multi gene panel for infantile cholestasis to be a sensitive and specific method overcoming the complexity of the phenotype-based, candidate gene approach. Three exemplary clinical cases of infants with cholestasis are presented and discussed in the context of their genetic and histopathological findings (autosomal recessive polycystic kidney disease, atypical PFIC and Niemann-Pick syndrome type C1). These case reports highlight the critical impact of integrating clinical, histopathological and genetic data during the process of multi gene panel testing to ultimately pinpoint rare genetic diagnoses.

[Heart rate: clinical variable and risk marker]. / Herzfrequenz: klinische Variable und Risikomarker.

Heart rate is an easily accessible clinical variable with wide-ranging prognostic impact. Elevated resting heart rate predicts an elevated cardiovascular risk. Epidemiological studies demonstrate a relevant association between heart rate and survival in individuals without diagnosed cardiovascular disease and with cardiovascular disease like hypertension, coronary artery disease (CAD) and heart failure. Whereas a goal directed pharmacological heart rate reduction is not supported by clinical evidence for primary prevention it plays a prognostic role for patients with CAD  and chronic heart failure. Moreover heart rate can be characterized as an independent risk factor for patients with heart failure and potentially for those with CAD. As a result the common guidelines recommend heart rate reduction as a target of therapy.

The dual PPARα/γ agonist aleglitazar increases the number and function of endothelial progenitor cells: implications for vascular function and atherogenesis.

BACKGROUND AND PURPOSE: Aleglitazar is a dual PPARα/γ agonist but little is known about its effects on vascular function and atherogenesis. Hence, we characterized its effects on circulating angiogenic cells (CAC), neoangiogenesis, endothelial function, arteriogenesis and atherosclerosis in mice. EXPERIMENTAL APPROACH: C57Bl/6 wild-type (WT, normal chow), endothelial NOS (eNOS)(-/-) (normal chow) and ApoE(-/-) (Western-type diet) mice were treated with aleglitazar (10 mg·kg(-1) ·day(-1) , i.p.) or vehicle. KEY RESULTS: Aleglitazar enhanced expression of PPARα and PPARγ target genes, normalized glucose tolerance and potently reduced hepatic fat in ApoE(-/-) mice. In WT mice, but not in eNOS(-/-) , aleglitazar up-regulated Sca-1/VEGFR2-positive CAC in the blood and bone marrow and up-regulated diLDL/lectin-positive CAC. Aleglitazar augmented CAC migration and enhanced neoangiogenesis. In ApoE(-/-) mice, aleglitazar up-regulated CAC number and function, reduced markers of vascular inflammation and potently improved perfusion restoration after hindlimb ischaemia and aortic endothelium-dependent vasodilatation. This was associated with markedly reduced formation of atherosclerotic plaques. In human cultured CAC from healthy donors and patients with coronary artery disease with or without diabetes mellitus, aleglitazar increased migration and colony-forming units in a concentration-dependent manner. Furthermore, oxidative stress-induced CAC apoptosis and expression of p53 were reduced, while telomerase activity and expression of phospho-eNOS and phospho-Akt were elevated. Comparative agonist and inhibitor experiments revealed that aleglitazar's effects on CAC migration and colony-forming units were mediated by both PPARα and PPARγ signalling and required Akt. CONCLUSIONS AND IMPLICATIONS: Aleglitazar augments the number, function and survival of CAC, which correlates with improved vascular function, enhanced arteriogenesis and prevention of atherosclerosis in mice.

Clinical parameters associated with collateral development in patients with chronic total coronary occlusion.

OBJECTIVE: Well-developed collaterals provide survival benefit in patients with obstructive coronary artery disease (CAD). Therefore, in this study we sought to determine which clinical variables are associated with arteriogenesis. DESIGN: Clinical and laboratory variables were collected before percutaneous coronary intervention. Multivariate analysis was performed to determine which variables are associated with the collateral flow index (CFI). PATIENTS: Data from 295 chronic total occlusion (CTO) patients (Bern, Switzerland, Amsterdam, the Netherlands and Jena, Germany) were pooled. In earlier studies, patients had varying degrees of stenosis. Therefore, different stages of development of the collaterals were used. In our study, a unique group of patients with CTO was analysed. INTERVENTIONS: Instead of angiography used earlier, we used a more accurate method to determine CFI using intracoronary pressure measurements. CFI was calculated from the occlusive pressure distal of the coronary lesion, the aortic pressure and central venous pressure. RESULTS: The mean CFI was 0.39 ± 0.14. After multivariate analysis, ß blockers, hypertension and angina pectoris duration were positively associated with CFI (B: correlation coefficient ß=0.07, SE=0.03, p=0.02, B=0.040, SE=0.02, p=0.042 and B=0.001, SE=0.000, p=0.02). Furthermore also after multivariate analysis, high serum leucocytes, prior myocardial infarction and high diastolic blood pressure were negatively associated with CFI (B=-0.01, SE=0.005, p=0.03, B=-0.04, SE=0.02, p=0.03 and B=-0.002, SE=0.001, p=0.011). CONCLUSIONS: In this unique cohort, high serum leucocytes and high diastolic blood pressure are associated with poorly developed collaterals. Interestingly, the use of ß blockers is associated with well-developed collaterals, shedding new light on the potential action mode of this drug in patients with CAD.

Bone marrow transplantation improves the outcome of Atm-deficient mice through the migration of ATM-competent cells.

Ataxia telangiectasia (A-T) is a highly pleiotropic disorder. Patients suffer from progressive neurodegeneration, severe bronchial complications, immunodeficiency, hypersensitivity to radiotherapy and elevated risk of malignancies. Leukemia and lymphoma, along with lung failure, are the main causes of morbidity and mortality in A-T patients. At present, no effective therapy for A-T exists. One promising therapeutic approach is bone marrow transplantation (BMT) that is already used as a curative therapy for other genomic instability syndromes. We used an established clinically relevant non-myeloablative host-conditioning regimen and transplanted green fluorescent protein (GFP)-expressing ataxia telangiectasia mutated (ATM)-competent bone marrow-derived cells (BMDCs) into Atm-deficient mice. GFP expression allowed tracking of the potential migration of the cells into the tissues of recipient animals. Donor BMDCs migrated into the bone marrow, blood, thymus, spleen and lung tissue of Atm-deficient mice showing an ATM-competent phenotype. BMT inhibited thymic lymphomas, normalized T-lymphocyte populations, improved weight gain and rearing activity of Atm-deficient mice. In contrast, no GFP(+) cells were found in the cerebellum or cerebrum, and we detected decreased size index in MRI imaging of the cerebellum in 8-month-old transplanted Atm-deficient mice in comparison to wild-type mice. The repopulation with ATM-competent BMDCs is associated with a prolonged lifespan and significantly improved the phenotype of Atm-deficient mice.

Quantum system characterization with limited resources.

The construction and operation of large-scale quantum information devices presents a grand challenge. A major issue is the effective control of coherent evolution, which requires accurate knowledge of the system dynamics that may vary from device to device. We review strategies for obtaining such knowledge from minimal initial resources and in an efficient manner, and apply these to the problem of characterization of a qubit embedded into a larger state manifold, made tractable by exploiting prior structural knowledge. We also investigate adaptive sampling for estimation of multiple parameters.

Second order gradient ascent pulse engineering.

We report some improvements to the gradient ascent pulse engineering (GRAPE) algorithm for optimal control of spin ensembles and other quantum systems. These include more accurate gradients, convergence acceleration using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton algorithm as well as faster control derivative calculation algorithms. In all test systems, the wall clock time and the convergence rates show a considerable improvement over the approximate gradient ascent.

[Update on anti-platelet therapy]. / Aktuelles zur Thrombozytenaggregationshemmung.

Use of the ADP (P2Y(12))-receptor antagonist clopidogrel is a cornerstone of dual platelet inhibition in acute coronary syndromes and following stent implantation. Because of the metabolization into its active form and the irreversible inhibition of the ADP receptor there are disadvantages to clopidogrel which could limit its efficacy in reducing clinical events. This is particularly problematic in so-called poor responders with reduced metabolizing activity and hence reduced platelet inhibition. Two novel drugs for platelet inhibition in acute coronary syndrome could become relevant in clinical practice. The irreversible ADP-receptor antagonist prasugrel led to stronger platelet inhibition, fewer ischemic events but more bleeding complications compared to clopidogrel in the TRITON-TIMI-38 trial. The reversibly binding, direct-acting ADP-receptor antagonist ticagrelor, which is effective without metabolization, is also superior over clopidogrel in reducing platelet aggregation and decreased the number of ischemic events in the PLATO-trial. However, it did not increase the rate of overall major bleeding and was shown to reduce total mortality. This review article summarizes current data on novel platelet inhibitors and delineates their potential influence on clinical practice.

[Preventing lower limb amputations in patients suffering from diabetic foot syndrome and peripheral vascular disease - opportunities and limitations]. / Grenzen und Möglichkeiten der Vermeidung von Majoramputationen der unteren Extremität bei Diabetischem Fußsyndrom und arterieller Verschlusskrankheit durch freien Gewebetransfer.

BACKGROUND: The number of patients suffering from a diabetic foot syndrome is increasing. In many cases large plantar or heel defects can only be reconstructed by using a free flap. The free parascapular flap is an alternative to free muscle flaps in the reconstruction of plantar or heel defects. Donor site morbidity is low. Autologous bypass reconstruction or an angioplasty can increase extremity perfusion. PATIENTS AND OPERATIONS: 52 patients with a diabetic foot syndrome have been reconstructed since 2007. 23 of them required a free tissue transfer. On average these patients were 68.7 years of age. A parascapular flap was used in 15 cases, a latissimus dorsi flap with a skin graft in 4 cases, a gracilis muscle flap with a skin graft in 3 cases. In one case a free instep flap of the contralateral foot, which had to be amputated, was used. In 13 cases the flap was anastomosed to the autologous bypass, in one case an AV loop was used. RESULTS: 22 flaps healed primarily. Only 1 patient was not able to walk at discharge. There was one flap loss. 4 patients required an amputation later on due to bypass failure or infection. 2 patients died due to cardiac arrest at the rehabilitation clinic. CONCLUSION: If the correct indication is met, free flaps can prevent diabetes-derived amputations of the lower limb. The parascapular flap can be used for plantar and heel defects. Flap harvesting is quick due to the constant vascular anatomy. The donor site morbidity is low. Reconstruction requires revascularisation in an interdisciplinary setting including vascular surgeons and radiologists. Limb salvage reduces mortality and improves quality of life. Revascularisation and reconstruction should best be done in a single surgical procedure.

The cholinergic system in rat testis is of non-neuronal origin.

The cholinergic system consists of acetylcholine (ACh), its synthesising enzyme, choline acetyltransferase (CHAT), transporters such as the high-affinity choline transporter (SLC5A7; also known as ChT1), vesicular ACh transporter (SLC18A3; also known as VAChT), organic cation transporters (SLC22s; also known as OCTs), the nicotinic ACh receptors (CHRN; also known as nAChR) and muscarinic ACh receptors. The cholinergic system is not restricted to neurons but plays an important role in the structure and function of non-neuronal tissues such as epithelia and the immune system. Using molecular and immunohistochemical techniques, we show in this study that non-neuronal cells in the parenchyma of rat testis express mRNAs for Chat, Slc18a3, Slc5a7 and Slc22a2 as well as for the CHRN subunits in locations completely lacking any form of innervation, as demonstrated by the absence of protein gene product 9.5 labelling. We found differentially expressed mRNAs for eight α and three ß subunits of CHRN in testis. Expression of the α7-subunit of CHRN was widespread in spermatogonia, spermatocytes within seminiferous tubules as well as within Sertoli cells. Spermatogonia and spermatocytes also expressed the α4-subunit of CHRN. The presence of ACh in testicular parenchyma (TP), capsule and isolated germ cells could be demonstrated by HPLC. Taken together, our results reveal the presence of a non-neuronal cholinergic system in rat TP suggesting a potentially important role for non-neuronal ACh and its receptors in germ cell differentiation.

[Significance of abdominal wall CT-angiography in planning DIEA perforator flaps, TRAM flaps and SIEA flaps]. / Stellenwert der CT-Angiografie der Bauchwand für die Planung und Operation von DIEP-, TRAM- und SIEA-Lappenplastiken.

Muscle sparing TRAM flaps and DIEA perforator flaps are standard procedures for breast reconstruction. Recently CT-angiography has been established to evaluate perforator vessels pre-operatively. CT-angiography was introduced to our department in July 2009. In a retrospective analysis data of the last 20 patients (altogether 22 flaps) before CT-angiography introduction and the following 20 (also 22 flaps) patients after introduction of CT-angiography were analysed with regard to the ratio of TRAM to DIEP flaps, and the time required to raise the flaps. The same surgeon raised all flaps. As different surgeons performed dissection of the recipient site, anastomoses, and insertion of flaps, and patients received primary (with sentinel or complete lymphadenctomy) or secondary reconstructions, only the time required harvesting the flap was compared. Thus other influences on raising the flap were eliminated. DIEP flaps were harvested with one single perforator. If perfusion or was considered not to be safe via one single perforator a muscle sparing TRAM flap (ms2) was raised. Angiography was performed using a 64-slice multi-detector CT scanner. CT-angiography did not lead to an increased rate of DIEP flaps in relation to ms2-TRAM flaps. Harvesting time of all flap types with CT-angiography on average was 121 min, without CT-angiography 135 min. This was not significantly different. However, separate analysis of DIEP flaps and ms2-TRAM flaps revealed a significant advantage of CT-angiography based harvesting of DIEP flaps of 26 min: with CT-angiography 101 min vs. 127 min without CT-angiography (p<0.028). There were no significant differences for ms2-TRAM flaps. All scans showed course and branching, diameter and size of the inferior epigastric artery. If evident the superficial inferior epigastric artery (SIEA) was marked. Dosage was 292 mGy-606 mGy×cm dependent on body weight. CTDI was 6.8-14.7 mGy. CT-angiography is a reproducible and observer independent procedure that reliably demonstrates the inferior epigastric artery and its perforating branches. Sensitivity is considered to be 99,6%. Additionally the superficial inferior epigastric artery can be evaluated. In our patients the ratio of ms2-TRAM flaps to DIEP flaps was not affected by introducing CT-angiography. However, DIEP flap harvesting was significantly accelerated. Harvesting of ms2-TRAM flaps was not affected. It remains to be seen whether the observed time advantage is really essential for this operation. Preoperative imaging of the perforators allows establishing a detailed, observable and comprehensible operation strategy, which particularly facilitates surgical training and learning of perforator dissection.

[Novel anticoagulants for stroke prevention in atrial fibrillation]. / Neue Antikoagulanzien für die Thromboembolieprophylaxe bei Vorhofflimmern.

The most frequent cardiac arrhythmia and main cause for cardio-embolic stroke is atrial fibrillation. Prophylaxis for thrombembolic events is performed regarding individual risk of patients with either ASS or vitamin-K-antagonists. Efficacy and safety of oral anticoagulation is limited by a narrow therapeutical range as well as by inter- and intraindividual variability of INR-values due to genetic disposition, differences in alimentation, dosage errors, rare control of INR-levels and drug-interactions. New oral anticoagulants with different mechanisms of action may be a promising therapeutic option in future. This review addresses the new anticoagulants Apixaban, Rivaroxban and Dabigatranetexilat with the design and as available the results of the corresponding phase-III-trials in atrial fibrillation (ARISTOTLE, ROCKET-AF, RE-LY).

[Purple glove syndrome - a case report]. / Purple Glove Syndrom nach peripherer venöser Phenytoin Gabe - Ein Fallbericht.

The purple glove syndrome (PGS) is a soft tissue injury after peripheral intravenous phenytoin administration or oral overdosage. The incidence of PGS is described with 0-6%. Typical symptoms are purple discoloration, oedema, pain, and a decrease of range of motion. In severe cases PGS may lead to abscess, skin loss and compartment syndrome. The established treatment of PGS is immediate interruption of phenytoin injections, splinting, elevation, and close observation. In cases of severe complications (e. g., compartment syndrome), surgical intervention is necessary. The case of a 40-year-old female patient is reported who was transferred to our department 4 days after intravenous phenytoin administration and who underwent successful surgical revision.

Hotlines and clinical trial updates presented at the European Society of Cardiology Meeting 2009: data from RE-LY, PLATO, MADIT-CRT, PROTECT, SYNTAX, TRITON and more.

This summary article provides an update on novel clinical trials in the field of cardiovascular (CV) medicine which were presented at the annual meeting of the European Cardiac Society, held in Barcelona, Spain, in August-September 2009. The data were presented by leading experts in the field with relevant positions in the trials and registries. Unpublished reports should be considered as preliminary data as the analysis may change in the final publications. This article provides the reader with comprehensive summaries of the most recent diagnostic and therapeutic developments in CV medicine as previously reported (Kindermann et al. in Clin Res Cardiol 96:767-786, 2007; Müller et al. in Clin Res Cardiol 97:851-864, 2008).

Hotline update of clinical trials and registries presented at the German Cardiac Society Meeting 2009.

This review article gives an overview on a number of novel clinical trials and registries in the field of cardiovascular medicine. Key presentations made at the 75th annual meeting of the German Cardiac Society, held in Mannheim, Germany, in April 2009 are reported. The data were presented by leading experts in the field with relevant positions in the trials and registries. These comprehensive summaries should provide the readers with the most recent data on diagnostic and therapeutic developments in cardiovascular medicine similar as previously reported (Rosenkranz et al. in Clin Res Cardiol 96:457-468, 9; Maier et al. in Clin Res Cardiol 97:356-363, 3).

[Mechanisms and potential of the therapeutic stimulation of arteriogenesis]. / Mechanismen und Möglichkeiten einer therapeutischen Stimulation der Arteriogenese.

The stimulation of collateral artery growth (arteriogenesis) is a promising alternative approach to non-invasively treat arterial obstructive disease, such as coronary, peripheral or cerebral artery disease. Patients unable to undergo conventional revascularization strategies may benefit from adaptive arteriogenesis. Underlying mechanisms are experimentally validated and include an increase in shear stress after obstruction or occlusion of a major artery; monocyte adhesion, transmigration and perivascular accumulation, secretion of growth factors; and smooth muscle and endothelial cell proliferation and growth of pre-existent collateral arteries. Therapeutic stimulation of arteriogenesis with cytokines has been successfully performed in experimental models. Translation into clinical practice, however, has hitherto been problematic. Reasons for this include differences between the healthy laboratory animal and an often severely diseased patient, possible harmful effects of pro-arteriogenic therapies and unsuitable clinical endpoints for the detection of collateral artery growth. Recent investigations of human arteriogenesis demonstrate significant inter-individual differences and point towards the importance of anti-arteriogenic mechanisms in patients with impaired adaptive arteriogenesis and high cardiovascular risk factors.

Stimulation of collateral artery growth: travelling further down the road to clinical application.

Collateral artery growth is a potent natural defence mechanism to prevent death and myocardial infarction in occlusive artery disease. Given the high prevalence of arterial obstructive disease, a therapeutic compound stimulating collateral vessel growth could have a major impact on morbidity and mortality world wide. Although experimental studies on the stimulation of arteriogenesis have been promising, not a single drug has been proved to be applicable in clinical practice, either because of lack of efficacy or because of undesired side effects. This review summarises current knowledge on the mechanisms of collateral artery growth and examines problems that arise from the clinical implementation of pro-arteriogenic treatments to date. Future directions in the translation from bench to bedside and potential new approaches to the stimulation of vascular growth are discussed.

[Alternative autologous breast reconstruction using the free microvascular gracilis muscle flap with horizontal skin island]. / Die alternative autologe Brustrekonstruktion mit dem queren Grazilislappen.

BACKGROUND: While free TRAM or DIEP flaps are still the most common techniques for autologous breast reconstruction, there are also other flaps which are suitable for patients who are not candidates for a TRAM/DIEP flap. In addition to the S-GAP or I-GAP, the transverse myocutaneous gracilis (TMG) flap is an excellent alternative. The tissue utilised is taken from the medial thigh and inferior gluteal area. PATIENTS AND OPERATIONS: We have performed 37 TMG flap operations on 23 patients since 2007. The indications were breast cancer, asymmetry of the breasts and capsular fibrosis. The average age of our patients was 47 years. Incisions are similar to those of a transverse thigh lift. The flap is nourished by perforators from the gracilis and its proximal dominant pedicle. The landmark ventrally is the greater saphenous vein and midpoint of the inferior gluteal fold on the dorsal side. Its size can go up to 30 x 10 cm. Recipient vessels are the internal thoracic vessels. The donor site is closed primarily. All of our patients are immobilised for 2 days and were instructed to avoid sitting for 2 weeks. RESULTS: 12 patients were reconstructed after breast cancer, 8 patients had a capsular fibrosis and 3 patients had an asymmetry. The follow-up period was 8 months. Mean operating time for unilateral reconstruction is 220 minutes, for bilateral reconstruction 325 minutes. The weight of the flaps varied from 220 to 440 grams. It takes approximately 30 minutes to harvest the flap. There was no flap loss. Some of the patients described a tight feeling on the thighs for 3 weeks. They described a hypaesthesia on the dorsal thighs. There was one delayed wound healing caused by haematoma. CONCLUSION: In our department, the TMG has become the most preferred flap for breast reconstruction besides the TRAM/DIEP. Especially slim patients with small breasts or a history of surgery on the abdominal wall are ideal candidates. The tissue from the medial thigh is very similar to the breast tissue. The constant vascular anatomy makes it easy to harvest the flap. The resulting scar is well hidden in the patients' underwear.

[Patients' satisfaction and social reintegration after breast reconstruction with the DIEP/TRAM flap]. / Brustrekonstruktion mit dem freien Bauchfettlappen (DIEP/TRAM): Patientenzufriedenheit und soziale Reintegration.

The aim of the study was to evaluate social reintegration and patients' perception after breast reconstruction with the free TRAM/DIEP flap. Between 2004 and 2006, 100 patients with an average age of 48 years with breast cancer, capsular contracture and lymphangioma underwent single or second stage autologous tissue transfer. In 7 patients reconstruction was performed on both sides (altogether 107 flaps). The patients were seen for postoperative evaluation and were asked for their personal acceptance after reconstruction. Postoperatively, no instability of the abdominal wall was seen. 3 patients had a total flap loss, in 2 patients a partial loss was evident, 1 had a hematoma, 2 showed successfully treated thrombosis of the flap vein, and 2 patients suffered from wound healing problems at the flap and 4 patients at the abdomen. Aesthetic results concerning natural feeling and breast symmetry were graded as excellent and patients' satisfaction was high.