[Pain management in sickle cell disease]. / Schmerztherapie bei Sichelzellkrankheit.

Sickle cell disease is associated with numerous symptoms and complications. Acute painful crisis is the most characteristic manifestation of the disease. In addition, many patients report chronic pain. As both acute and chronic pain severely diminish quality of life, adequate pain management is crucial. Recommendations for the treatment of acute painful crises are based on the World Health Organization analgesic ladder, which has been developed for cancer-related pain. Chronic pain can be treated with basic long-acting opioids and on-demand short-acting opioids. If patients show signs of neuropathic pain, administration of anticonvulsants, antidepressants or possibly ketamine should be considered.

[Pain management in rare diseases]. / Schmerztherapie bei seltenen Erkrankungen.

In this article we address the relevance of rare diseases and their peculiarities with respect to pain therapy. Towards this end, four rare diseases (hemophilia, Morbus Fabry, dermatomyositis, and facioscapulohumeral dystrophy (FSHD)) will be presented and fundamental aspects of their pain therapies described. The diseases were chosen to showcase a pain therapy based on the WHO-step-by-step plan (hemophilia), a complex but established pain therapy (M. Fabry), and two less well established, individually adapted pain therapies (dermatomyositis, FSHD).

Pharmacological inhibition of porcupine induces regression of experimental skin fibrosis by targeting Wnt signalling.

OBJECTIVES: Wnt signalling has been implicated in activating a fibrogenic programme in fibroblasts in systemic sclerosis (SSc). Porcupine is an O-acyltransferase required for secretion of Wnt proteins in mammals. Here, we aimed to evaluate the antifibrotic effects of pharmacological inhibition of porcupine in preclinical models of SSc. METHODS: The porcupine inhibitor GNF6231 was evaluated in the mouse models of bleomycin-induced skin fibrosis, in tight-skin-1 mice, in murine sclerodermatous chronic-graft-versus-host disease (cGvHD) and in fibrosis induced by a constitutively active transforming growth factor-ß-receptor I. RESULTS: Treatment with pharmacologically relevant and well-tolerated doses of GNF6231 inhibited the activation of Wnt signalling in fibrotic murine skin. GNF6231 ameliorated skin fibrosis in all four models. Treatment with GNF6231 also reduced pulmonary fibrosis associated with murine cGvHD. Most importantly, GNF6231 prevented progression of fibrosis and showed evidence of reversal of established fibrosis. CONCLUSIONS: These data suggest that targeting the Wnt pathway through inhibition of porcupine provides a potential therapeutic approach to fibrosis in SSc. This is of particular interest, as a close analogue of GNF6231 has already demonstrated robust pathway inhibition in humans and could be available for clinical trials.

Targeting Wnt-driven cancer through the inhibition of Porcupine by LGK974.

Wnt signaling is one of the key oncogenic pathways in multiple cancers, and targeting this pathway is an attractive therapeutic approach. However, therapeutic success has been limited because of the lack of therapeutic agents for targets in the Wnt pathway and the lack of a defined patient population that would be sensitive to a Wnt inhibitor. We developed a screen for small molecules that block Wnt secretion. This effort led to the discovery of LGK974, a potent and specific small-molecule Porcupine (PORCN) inhibitor. PORCN is a membrane-bound O-acyltransferase that is required for and dedicated to palmitoylation of Wnt ligands, a necessary step in the processing of Wnt ligand secretion. We show that LGK974 potently inhibits Wnt signaling in vitro and in vivo, including reduction of the Wnt-dependent LRP6 phosphorylation and the expression of Wnt target genes, such as AXIN2. LGK974 is potent and efficacious in multiple tumor models at well-tolerated doses in vivo, including murine and rat mechanistic breast cancer models driven by MMTV-Wnt1 and a human head and neck squamous cell carcinoma model (HN30). We also show that head and neck cancer cell lines with loss-of-function mutations in the Notch signaling pathway have a high response rate to LGK974. Together, these findings provide both a strategy and tools for targeting Wnt-driven cancers through the inhibition of PORCN.

Dural ectasia in Loeys-Dietz syndrome: comprehensive study of 30 patients with a TGFBR1 or TGFBR2 mutation.

The purpose of this study was to assess the frequency, severity, and clinical associations of dural ectasia (DE) in Loeys-Dietz syndrome (LDS). Database analysis of three German metropolitan regions identified 30 patients with LDS and TGFBR1 mutation in 6 and a TGFBR2 mutation in 24 individuals (17 men; mean age: 31 ± 19 years), as well as 60 age and sex-matched control patients with Marfan syndrome carrying a FBN1 mutation. DE was present in 22 patients with LDS (73%), and it related to skeletal score points (p = 0.008), non-skeletal score points (p < 0.001), and to the presence of ≥7 systemic score points (p = 0.010). Similarly, the severity of DE was related to body height (p = 0.010) and non-skeletal score points (p = 0.004). Frequency (p = 0.131) and severity of DE (p = 0.567) was similar in LDS and Marfan syndrome. DE is a manifestation of LDS that occurs with similar frequency and severity as in Marfan syndrome. Severity of DE may serve as a marker of the overall connective tissue disease severity. LDS may be considered in patients with DE.

Discovery of structurally novel, potent and orally efficacious GPR119 agonists.

Screening hit 5 was identified in a biochemical screen for GPR119 agonists. Compound 5 was structurally novel, displayed modest biochemical activity and no oral exposure, but was structurally distinct from typical GPR119 agonist scaffolds. Systematic optimization led to compound 36 with significantly improved in vitro activity and oral exposure, to elevate GLP1 acutely in an in vivo mouse model at a dose of 10mg/kg.

Novel tricyclic pyrazolopyrimidines as potent and selective GPR119 agonists.

Systematic SAR optimization of the GPR119 agonist lead 1, derived from an internal HTS campaign, led to compound 29. Compound 29 displays significantly improved in vitro activity and oral exposure, leading to GLP1 elevation in acutely dosed mice and reduced glucose excursion in an OGTT study in rats at doses ⩾10 mg/kg.

The effect of respiratory diseases on serum lactate dehydrogenase and its isoenzyme patterns in calves.

In this study we examined the serum activity of lactate dehydrogenase (LDH) and its isoenzyme patterns in 28 calves of a lowland black spotted breed and its crossbreeds at the age of 2-6 months suffering from clinically noticeable manifested respiratory diseases--bronchopneumonia (BRD Group). As a control group we used 35 clinically healthy calves of the same age, breed and nutrition (Healthy Group). The sick calves did not show clinical signs or pathological lesions on other organ systems. The results found in sick calves showed a significantly higher total activity of LDH than in clinically healthy animals (P < 0.01). The mean activity of LDH was 2012 U/I in healthy calves and in calves with respiratory diseases 2529 U/1. The differences in all LDH isoenzyme patterns between both groups of animals were significant (P < 0.001) and in calves with respiratory diseases are characterized by a marked increase of the LDH 1 fraction and a decrease in the proportion of the other four LDH isoenzymes. Our results differ from those observed and presented in respiratory diseases in human medicine or in sheep. The explanation for the obtained results in calves and the determination of their diagnostic significance needs further studies and investigations using more animals with various severity of clinical signs and pathological changes, including analysis and determination of lactate dehydrogenase isoenzyme patterns in healthy and affected cattle lung tissue.

Evidence for mast cell activation in patients with therapy-resistant irritable bowel syndrome.

Previous findings suggested an involvement of mast cells in the pathogenesis of irritable bowel syndrome (IBS). The pathophysiological significance of mast cells is defined both by their number in tissue and by their activity. In the present pilot study activity of mast cells in patients with therapy-resistant IBS was investigated for the first time systematically. Twenty patients with therapy-resistant IBS were investigated for the presence of a pathologically increased mast cell mediator release by means of a validated structured interview suitable to identify mast cell mediator-related symptoms and by determing selected surrogate parameters for mast cell activity. Nineteen of the 20 patients presented mast cell mediator-related symptoms. Pathologically increased mast cell activity-related coagulation and fibrinolysis parameters were detected in 11 of 12 patients investigated in that regard. One patient had an elevated level of methylhistamine in urine. The present data provide evidence that in patients with therapy-resistant IBS a pathologically increased systemic mast cell activity may occur with high prevalence. This finding fits to the idea of an assumed contribution of activated mast cells in the pathophysiology of IBS.

The impact and management of acquired platelet dysfunction.

Platelet function can be abnormally increased, as in association with acute vascular events, or defective, as in a variety of clinical settings. Acquired platelet dysfunction may occur at any age and range in severity from mild to life-threatening haemorrhages. Diagnostic work-up of platelet disorders requires meticulous evaluation of medical history, specifically of any drugs interfering with platelet function, careful clinical examination and a staged laboratory protocol to assess the underlying platelet defect(s). To identify hyperactive platelets ex vivo, costly procedures may be required using flow cytometry and distict epitope-specific monoclonal antibodies. Currently, this approach can be recommended for research purposes only. Drugs represent the most common cause of platelet dysfunction in our overmedicated society. While aspirin, clopigogrel (more recently also prasugrel) and integrin αIIbß3 (GPIIb-IIIa) receptor antagonists (abciximab, eptifibatide and tirofiban) are well-known prototypes of antiplatelet drugs, other widely used agents (e.g. nonsteroidal anti-inflammatory drugs, antibiotics, serotonin reuptake inhibitors and volume expanders) can also impair platelet function and thus cause or aggravate hemorrhages. Identification of individual patients with pre-existing hemostatic defects remains crucial (i) to prevent bleeding complications, (ii) to manage symptoms adequately, (iii) to minimize the risk from invasive procedures, and (iv) to avoid unnecassary exposure to blood products. Screening for platelet dysfunction can be performed by point-of-care testing followed by platelet aggregometry in response to various agonists. While mild bleeding episodes due to antiplatelet therapy can be managed by withdrawal of the drug(s), severe hemorrhages may require immediate platelet transfusions. Apart from that, the prohemostatic armamentarium is limited to desmopressin, antifibrinolytic agents, and recombinant factor VIIa.

Monitoring of antiplatelet therapy. Current limitations, challenges, and perspectives.

Screening of platelet function can be performed by point-of-care testing followed by platelet aggregometry in response to agonists such as collagen, adenosine diphosphate, epinephrine, and arachidonic acid. Despite in use for decades, this technique is not well standardized. Monitoring of antiplatelet therapy is increasingly applied in patients at high risk for re-thrombosis or bleeding. To assess pharmacological inhibition of platelet function, agonist-induced platelet aggregation, thromboxane B2 (TxB2) and vasodilator-stimulated protein phosphorylation (VASP) are being measured. While serum TxB2 levels of < 2 ng/ml reflect aspirin-induced inhibition of cyclo-oxygenase-1 activity with high sensitivity, VASP exhibits a wide variability upon treatment with clopidogrel or prasugrel. Multiple studies reveal an association between high residual platelet reactivity and adverse cardiovascular events in patients on antiplatelet therapy. However, despite the plethora of platelet function assays currently under investigation, their use in daily practice cannot be recommended. This is due to several reasons: (i) there is no consensus on the method and a respective cut-off value associated with clinical adverse outcome, and (ii) data demonstrating any benefit of tailored antiplatelet therapy and its monitoring (based on assessment of platelet functions) are still limited. Thus, appropriate identification of 'resistant' or 'poor responders' to antiplatelet agents remains challenging in clinical practice.

Nidufexor (LMB763), a Novel FXR Modulator for the Treatment of Nonalcoholic Steatohepatitis.

Farnesoid X receptor (FXR) agonists are emerging as important potential therapeutics for the treatment of nonalcoholic steatohepatitis (NASH) patients, as they exert positive effects on multiple aspects of the disease. FXR agonists reduce lipid accumulation in the liver, hepatocellular inflammation, hepatic injury, and fibrosis. While there are currently no approved therapies for NASH, the bile acid-derived FXR agonist obeticholic acid (OCA; 6-ethyl chenodeoxycholic acid) has shown promise in clinical studies. Previously, we described the discovery of tropifexor (LJN452), the most potent non-bile acid FXR agonist currently in clinical investigation. Here, we report the discovery of a novel chemical series of non-bile acid FXR agonists based on a tricyclic dihydrochromenopyrazole core from which emerged nidufexor (LMB763), a compound with partial FXR agonistic activity in vitro and FXR-dependent gene modulation in vivo. Nidufexor has advanced to Phase 2 human clinical trials in patients with NASH and diabetic nephropathy.

Discovery of pyrimidine benzimidazoles as Src-family selective Lck inhibitors. Part II.

A series of 4-amino-6-benzimidazole-pyrimidines was designed to target lymphocyte-specific tyrosine kinase (Lck), a member of the Src-family kinases (SFKs). These type II inhibitors were optimized using a cellular Lck-dependent proliferation assay and are capable of inhibiting Lck at single-digit nanomolar concentrations. This scaffold is likely to serve a valuable template for developing potent inhibitors of a number of SFKs.

Mutation and phenotypic spectrum in patients with cardio-facio-cutaneous and Costello syndrome.

Cardio-facio-cutaneous (CFC) and Costello syndrome (CS) are congenital disorders with a significant clinical overlap. The recent discovery of heterozygous mutations in genes encoding components of the RAS-RAF-MAPK pathway in both CFC and CS suggested a similar underlying pathogenesis of these two disorders. While CFC is heterogeneous with mutations in BRAF, MAP2K1, MAP2K2 and KRAS, HRAS alterations are almost exclusively associated with CS. We carried out a comprehensive mutation analysis in 51 CFC-affected patients and 31 individuals with CS. Twelve different BRAF alterations were found in twenty-four patients with CFC (47.0%), two MAP2K1 mutations in five (9.8%) and two MAP2K2 sequence variations in three CFC-affected individuals (5.9%), whereas three patients had a KRAS alteration (5.9%). We identified four different missense mutations of HRAS in twenty-eight cases with CS (90.3%), while KRAS mutations were detected in two infants with a phenotype meeting criteria for CS (6.5%). In 14 informative families, we traced the parental origin of HRAS alterations and demonstrated inheritance of the mutated allele exclusively from the father, further confirming a paternal bias in the parental origin of HRAS mutations in CS. Careful clinical evaluation of patients with BRAF and MAP2K1/2 alterations revealed the presence of slight phenotypic differences regarding craniofacial features in MAP2K1- and MAP2K2-mutation positive individuals, suggesting possible genotype-phenotype correlations.

Discovery of pyrimidine benzimidazoles as Lck inhibitors: part I.

A series of 4-amino-6-benzimidazole-pyrimidines was designed to target lymphocyte-specific tyrosine kinase (Lck), a member of the Src kinase family. Highly efficient parallel syntheses were devised to prepare analogues for SAR studies. A number of these 4-amino-6-benzimidazole-pyrimidines exhibited single-digit nanomolar IC(50)s against Lck in biochemical and cellular assays. These 4-amino-6-benzimidazole-pyrimidines represent a new class of tyrosine kinase inhibitors.

Optimization of small molecule agonists of the thrombopoietin (Tpo) receptor derived from a benzo[a]carbazole hit scaffold.

The lead optimization of a novel series of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor is reported. The chemical instability of the dihydro-benzo[a]carbazole lead 2 was successfully addressed in the design and evaluation of compounds which also demonstrated improved potency compared to 2. Members of the scaffold have been identified which are full agonists that demonstrate cellular functional potency <50 nM. Analog 21 demonstrates equivalent efficacy in the human megakaryocyte differentiation (CFU-mega) assay compared to Eltrombopag.

Discovery and biological evaluation of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor.

A novel series of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor is reported. Starting from a 3.4 microM high throughput screen hit, members of this series have been identified which are full agonists with functional potency <50 nM and oral bioavailability in mice.

Compound heterozygosity for three common MEFV mutations in a highly consanguineous family with familial Mediterranean fever.

Consanguinity is not the only factor influencing the occurrence of autosomal recessive disorders such as familial Mediterranean fever (FMF). The extended, multiple consanguineous Turkish pedigree presented here demonstrates that the population frequency of certain mutations (so-called "ancient" mutations) can be at least equally important. In high-risk populations different combinations of mutations can occur within the same family, increasing not only the intrafamilial clinical variability, but also causing considerable recurrence risks even in marriages with unrelated spouses.

Sulphur transformation and deposition in the rhizosphere of Juncus effusus in a laboratory-scale constructed wetland.

Sulphur cycling and its correlation to removal processes under dynamic redox conditions in the rhizosphere of helophytes in treatment wetlands are poorly understood. Therefore, long-term experiments were performed in laboratory-scale constructed wetlands treating artificial domestic wastewater in order to investigate the dynamics of sulphur compounds, the responses of plants and nitrifying microorganisms under carbon surplus conditions, and the generation of methane. For carbon surplus conditions (carbon:sulphate of 2.8:1) sulphate reduction happened but was repressed, in contrast to unplanted filters mentioned in literature. Doubling the carbon load caused stable and efficient sulphate reduction, rising of pH, increasing enrichment of S(2-) and S(0) in pore water, and finally plant death and inhibition of nitrification by sulphide toxicity. The data show a clear correlation of the occurrence of reduced S-species with decreasing C and N removal performance and plant viability in the experimental constructed wetlands.

[New insight in therapeutic anticoagulation by Coumarin derivatives]. / Neue Einsichten in die orale Antikoagulations-therapie mit Cumarinen.

The recent identification of vitamin K epoxid-reductase complex (VKORC1) contributed significantly to our mechanistic understanding of the vitamin K cycle. VKORC1 protein is targeted by Coumarins. Its enzymatic activity represents the rate-limiting step in the vitamin K cycle and gamma-carboxylation of vitamin K dependent proteins. Possibly, VKORC1 is the only component of VKOR activity. Mutations as well as polymorphisms in coding and non-coding regions of the VKORC1 gene have been shown to cause both partial to total coumarin resistance and coumarin sensitivity. Availability of molecular diagnostics (VKORC1, CYP2C9) and laboratory analysis by HPLC (determination of coumarin, vitamin K and vitamin K epoxide levels) is helpful in detection of hereditary and acquired factors influencing coumarin therapy. In the future, these tools might lead to an individualized and safer oral anticoagulation therapy. Furthermore, daily low-dose vitamin K supplementation may improve stability of coumarin-based anticoagulation. In the perspective of the coming new oral anticoagulants, the efficacy and safety profile of the "old" anticoagulants is of major importance. The well established and oeconomic coumarin drugs will benefit from a pharmacogenetic and nutritive adjusted optimization of therapy.