Cost-effectiveness of adalimumab for rheumatoid arthritis in Germany.

BACKGROUND: In Germany, the clinical use of TNF-α inhibitors in the therapy of rheumatoid arthritis (RA) grew from 2 % of treated patients in 2000 to 20 % in 2008. In 2012, adalimumab was the bestselling drug in the statutory health insurance system with net expenditure of € 581 mio. OBJECTIVES: We aim to analyze the cost-effectiveness of adalimumab for the treatment of RA in Germany. METHODS: We set up an individual patient sampling lifetime model to simulate 10,000 hypothetical patients. The patients' functional status improves according to American College of Rheumatology response criteria. In each 6­month cycle, treatment might be discontinued due to loss of efficacy or adverse events. RESULTS: In the base case, patients gain 7.07 quality-adjusted life years (QALYs) with conventional synthetic therapy and 9.92 QALYs if adalimumab combination therapy is added to the treatment algorithm. The incremental cost-utility ratio (ICUR) is € 24,492 based on German list prices. After deducting mandatory rebates and taxes, the ICUR is € 17,277, comparing favorably to analyses in other countries. Adalimumab combination therapy lowers indirect costs from € 162,698 to € 134,363. The ICUR based on total costs is € 14,550 (€ 7,335 after deducting taxes and rebates). Sensitivity analysis shows that adalimumab combination therapy becomes a dominant treatment option for younger baseline populations, i. e. adalimumab is both more effective and less expensive for baseline age 30 due to savings in indirect costs. CONCLUSIONS: Our complex probabilistic model shows that estimation of cost-effectiveness for RA relies on the incorporation of indirect costs and a sufficiently long simulation horizon to capture the complete range of possible outcomes and the associated long-term benefits of biological treatment.

[Persistent skin reaction and Raynaud phenomenon after a sting by Echiichthys draco (great weever fish)]. / Persistierende Hautreaktion und Raynaud-Syndrom nach einem Stich durch den Fisch Echiichthys draco (Petermännchen).

A 54-year-old recreational angler was stung in his right forefinger by Echiichthys draco. Within a few seconds he developed severe swelling with extreme pain sensation at the sting site, accompanied by dizziness and chill. Even under morphine therapy the pain symptoms were only slightly reduced. During the subsequent weeks, an erythema with marginate medium-sized scaling developed at the sting site and the patient experienced a approximately 50% reduced bending capacity of the forefinger and permanent numbness in this region. After 4 months, Raynaud phenomenon developed limited to the right forefinger. Great weever fishes (Echiichthys spp.) are the most venomous fishes in European waters. In humans, life-threatening sting reactions occur only in exceptional cases. As a commercial antiserum is not available, the therapy is mainly empiric (General measures of first aid and emergency medicine, the wound should be thoroughly washed). Patients should be informed that reduced motion ability, swelling or Raynaud's phenomenon can persist for several months.

Lysophospholipids induce membrane hyperpolarization in microglia by activation of IKCa1 Ca(2+)-dependent K(+) channels.

Effects of the lysophospholipids sphingosine-1-phosphate and lysophosphatidic acid were studied in cultured murine microglia using the patch-clamp and video imaging techniques. Both lysophospholipids induced transient membrane hyperpolarization and K(+) current activation. The lysophospholipid-induced K(+) current was blocked by charybdotoxin or iberiotoxin, but was unaffected by apamin. In recordings with 1 microM intracellular free Ca(2+), Ca(2+)-dependent K(+) currents of microglia showed a similar pharmacological profile to lysophospholipid-induced currents. The Ca(2+)-dependent K(+) channels activated in microglia by lysophospholipids are most likely encoded by the IKCa1 channel gene. The presence of IKCa1 mRNA in microglia was demonstrated by reverse transcriptase-polymerase chain reaction studies. Ca(2+) imaging experiments revealed increases in the intracellular free Ca(2+) concentration of microglia to a mean value of about 400 nM after application of 1 microM sphingosine-1-phosphate or 1 microM lysophosphatidic acid. We suggest that the transient membrane hyperpolarization seen in microglia following exposure to sphingosine-1-phosphate or lysophosphatidic acid is caused by activation of IKCa1 Ca(2+)-dependent K(+) channels. Increases in the concentration of intracellular free Ca(2+) evoked by the lysophospholipids are sufficient to activate microglial Ca(2+)-dependent K(+) channels.

Activation of a Ca2+-dependent K+ current in mouse fibroblasts by sphingosine-1-phosphate involves the protein tyrosine kinase c-Src.

Sphingosine-1-phosphate (S1P) is a phospholipid that acts through G-protein-coupled plasma membrane receptors and induces a broad spectrum of cellular responses, including proliferation, migration, differentiation and apoptosis. Here we report that in NIH3T3 and C3H10T1/2 mouse fibroblasts S1P activates a Ca2+-dependent, voltage-independent K+ current (EC50-value 113 nM) that is blocked by the K+ channel blockers charybdotoxin, margatoxin, and iberiotoxin. The K+ current activation by S1P is transient and leads to a large membrane hyperpolarization. Recently, we showed that lysophosphatidic acid (LPA), a serum lipid with similar biological effects compared to those of S1P, can activate a Ca2+-dependent K+ current in NIH3T3 cells that has identical properties compared to the one that is activated by S1P. When applied consecutively, both S1P and LPA induced a K+ current response in NIH3T3 cells, which indicates that the K+ current activation is not subjected to cross-desensitization between S1P and LPA. In C3H10T1/2 mouse fibroblasts that overexpress the nonreceptor protein tyrosine kinase c-Src, the amplitude of the S1P-induced K+ current was almost doubled compared to the one that we found in control cells. Expression of a non-myristylated c-Src mutant led to a further increase in the K+ current response to S1P, whereas expression of a kinase-defective c-Src mutant reduced it to about 40% compared to the control value. Our data show that S1P activates Ca2+-dependent K+ channels in mouse fibroblasts via an intracellular signalling pathway that involves the non-receptor protein tyrosine kinase c-Src.

Bacillus intermedius ribonuclease as inhibitor of cell proliferation and membrane current.

The antiproliferative action of the guanine-specific ribonuclease secreted by Bacillus intermedius (binase) was studied in different chicken and mouse cell lines. The proliferation rate of chicken embryo fibroblasts, either normal or Rous sarcoma virus-transformed, was significantly reduced by binase treatment. Among mouse fibroblasts, v-ras-transformed NIH3T3 cells were sensitive to binase, whereas the growth of non-transformed, v-src-transformed or v-fms-transformed NIH3T3 cells was not affected. A 48 h treatment with binase inhibited the Ca2+-dependent K+ current of v-ras-transformed NIH3T3 cells but had no effect on this membrane current in non-transformed and in v-src- or v-fms-transformed NIH3T3 cells. Our results suggest that mammalian cells expressing the ras-oncogene are a potential target for the antiproliferative action of binase.

Activation of a Ca2+-dependent K+ current in mouse fibroblasts by lysophosphatidic acid requires a pertussis toxin-sensitive G protein and Ras.

Lysophosphatidic acid (LPA) is a bioactive lipid that acts through G protein-coupled plasma membrane receptors and mediates a wide range of cellular responses. Here we report that LPA activates a K+ current in NIH3T3 mouse fibroblasts that leads to membrane hyperpolarization. The activation occurs with an EC50 value of 1.7 nM LPA. The K+ current is Ca2+-dependent, voltage-independent, and completely blocked by the K+ channel blockers charybdotoxin, margatoxin, and iberiotoxin with IC50 values of 1.7, 16, and 62 nM, respectively. The underlying K+ channels possess a single channel conductance of 33 pS in symmetrical K+ solution. Pretreatment of cells with pertussis toxin (PTX), Clostridium sordellii lethal toxin, or a farnesyl protein transferase inhibitor reduced the K+ current amplitude in response to LPA to about 25% of the control value. Incubation of cells with the protein tyrosine kinase inhibitor genistein or microinjection of the neutralizing anti-Ras monoclonal antibody Y13-259 reduced it by more than 50%. In contrast, the phospholipase C inhibitor U-73122 and the protein kinase A activator 8-bromo-cAMP had no effect. These results indicate that the K+ channel activation by LPA is mediated by a signal transduction pathway involving a PTX-sensitive G protein, a protein tyrosine kinase, and Ras. LPA is already known to activate Cl- channels in various cell types, thereby leading to membrane depolarization. In conjunction with our results that demonstrate LPA-induced membrane hyperpolarization by activation of K+ channels, LPA appears to be significantly involved in the regulation of the cellular membrane potential.

Infectious bursal disease virus changes the potassium current properties of chicken embryo fibroblasts.

Infectious bursal disease virus (IBDV) is the causative agent of an economically significant poultry disease. IBDV infection leads to apoptosis in chicken embryos and cell cultures. Since changes in cellular ion fluxes during apoptosis have been reported, we investigated the membrane ion currents of chicken embryo fibroblasts (CEFs) inoculated with the Cu-1 strain of IBDV using the patch-clamp recording technique. Incubation of CEFs with IBDV led to marked changes in their K+ outward current properties, with respect to both the kinetics of activation and inactivation and the Ca2+ dependence of the activation. The changes occurred in a time-dependent manner and were complete after 8 h. UV-treated noninfectious virions induced the same K+ current changes as live IBDV. When CEFs were inoculated with IBDV after pretreatment with a neutralizing antibody, about 30% of the cells showed a normal K+ current, whereas the rest exhibited K+ current properties identical to or closely resembling those of IBDV-infected cells. Incubation of CEFs with culture supernatant from IBDV-infected cells from which the virus particles were removed had no influence on the K+ current. Our data strongly suggest that the K+ current changes induced by IBDV are not due to virus replication, but are the result of attachment and/or membrane penetration. Possibly, the altered K+ current may delay the apoptotic process in CEFs after IBDV infection.

Activation of a Ca2+-dependent K+ current by the oncogenic receptor protein tyrosine kinase v-Fms in mouse fibroblasts.

We investigated the effects of the receptor-coupled protein tyrosine kinase (RTK) v-Fms on the membrane current properties of NIH3T3 mouse fibroblasts. We found that v-Fms, the oncogenic variant of the macrophage colony-stimulating factor receptor c-Fms, activates a K+ current that is absent in control cells. The activation of the K+ current was Ca2+-dependent, voltage-independent, and was completely blocked by the K+ channel blockers charybdotoxin, margatoxin and iberiotoxin with IC50 values of 3 nM, 18 nM and 76 nM, respectively. To identify signalling components that mediate the activation of this K+ current, NIH3T3 cells that express different mutants of the wild-type v-Fms receptor were examined. Mutation of the binding site for the Ras-GTPase-activating protein led to a complete abolishment of the K+ current. A reduction of 76% and 63%, respectively, was observed upon mutation of either of the two binding sites for the growth factor receptor binding protein 2. Mutation of the ATP binding lobe, which disrupts the protein tyrosine kinase activity of v-Fms, led to a 55% reduction of the K+ current. Treatment of wild-type v-Fms cells with Clostiridium sordellii lethal toxin or a farnesyl protein transferase inhibitor, both known to inhibit the biological function of Ras, reduced the K+ current amplitude to 17% and 6% of the control value, respectively. This is the first report showing that an oncogenic RTK can modulate K+ channel activity. Our results indicate that this effect is dependent on the binding of certain Ras-regulating proteins to the v-Fms receptor and is not abolished by disruption of its intrinsic protein tyrosine kinase activity. Furthermore, our data suggest that Ras plays a key role for K+ channel activation by the oncogenic RTK v-Fms.

Diltiazem increases blood concentrations of cyclized cyclosporine metabolites resulting in different cyclosporine metabolite patterns in stable male and female renal allograft recipients.

1. Six male and six female stable renal allograft recipients under cyclosporine immunosuppression and without concomitant therapy with drugs known either to induce or inhibit CYP3A enzymes were included in the study and received 180 mg day-1 diltiazem for 1 week in a two-period cross-over fashion. Cyclosporine (352 +/- 56 mg day-1) was given in two daily oral doses. The daily doses were not changed during the study. Blood samples were collected for 12 h after receiving cyclosporine alone and after receiving diltiazem in addition for 1 week. Cyclosporine and nine of its metabolites were quantified using h.p.l.c. 2. Co-administration of diltiazem caused a 1.6 fold increase of the AUC (0, 12 h) of cyclosporine and a 1.7 fold increase of the AUC(0, 12 h) of its metabolites. Analysis of the metabolite patterns showed an over-proportional increase of the AUC(0, 12 h) of the cyclized metabolites AM1c (2.6 fold) and AM1c9 (2.2 fold). The AUC(0, 12 h) values of cyclosporine and the hydroxylated metabolites increased less than two fold. 3. Differences of the AUC(0, 12 h) values of cyclosporine with and without diltiazem were significantly higher in female than in male patients (P < 0.02). The differences in the AUC(0, 12 h) values of the metabolites, especially AM1c, tended to be higher in female patients as well. 4. It is concluded that coadministration of diltiazem not only increases the blood concentration of cyclosporine but also those of its metabolites, leads to a shift of the metabolite pattern towards cyclized metabolites, and that the pharmacokinetic changes under diltiazem administration are more prominent in female than in male patients.

Src-transformation of mouse fibroblasts induces a Ca(2+)-activated K+, current without changing the T-type Ca2+ current.

Membrane currents of src-transformed NIH3T3 mouse fibroblasts were analyzed in comparison with their non-transformed counterparts using the patch-clamp technique. Normal NIH3T3 cells exhibit two types of Ca2+ currents and a membrane current of ohmic behaviour (current amplitude 135 pA at +30 mV) that can partially be blocked by Cd2+. Src-transformed NIH3T3 cells show an additional membrane current that becomes activated after the establishment of the whole-cell configuration with a maximum amplitude of 1040 pA at +30 mV within 30-60 s. This current then inactivates irreversibly within 5-10 min. The additional current is highly K(+)-selective and Ca(2+)-dependent but voltage-independent. It can be blocked by charybdotoxin (IC50 = 20 nM) and by internal tetraethylammonium (TEA; IC50 = 2.9 mM), but it is not sensitive to external TEA (up to 30 mM). Single-channel analysis revealed only one K+ channel type with a conductance of 37 pS at negative potentials and 18 pS at positive potentials (in symmetrical 145 mM K+ solutions), a voltage-independent open-state probability of 0.6 and the same pharmacological properties as the macroscopic KCa current. The properties of the KCa current and the underlying channels of src-transformed NIH3T3 cells are identical to those observed in ras-transformed NIH3T3 cells. In contrast, src- or ras-transformation affects differently the voltage-dependent, transient (T-type) Ca2+ current. While ras-transformation of NIH3T3 cells suppresses their T-type Ca2+ current, this current remains unchanged in src-transformed NIH3T3 cells.

Initial feasibility studies using single-shot EPI for the detection of focal liver lesions.

Echo planar MR imaging (EPI) has been developed to completely eliminate motion artifacts and is currently being prepared for implementation into clinical MR systems. Thus, the purpose of this study was to evaluate the clinical utility of EPI in the detection of focal liver lesions and to compare EPI with in the detection of focal liver lesions and to compare EPI with contrast-enhanced CT. EPI studies were performed on an experimental 1.0 Tesla whole body system using fat-suppressed single-shot spin echo (SE) and inversion recovery (IR) pulse sequences. A total of 26 liver tumors in 12 patients scheduled for liver resection were prospectively examined and correlated with intraoperative ultrasound, surgery, and pathology as the gold standard. Quantitative analysis of EPI was performed by means of liver signal-to-noise and tumor-liver contrast-to-noise calculations. Diagnostic performance compared with contrast-enhanced CT was assessed by means of ROC analysis. Lesion-liver contrast was highest with EPI SE at a TE-time of 70 ms and this technique showed best lesion detectability as measured by area under curve (AUC) values. Among EPI techniques, the IR sequence with an inversion time of 300 ms to null the liver signal showed high lesion-liver contrast but all four reviewers reported problems assessing liver anatomy. Improved EPI techniques may prove useful for screening of focal liver lesions.

Potassium single-channel properties in normal and Rous sarcoma virus-transformed chicken embryo fibroblasts.

Ion channels in normal and Rous sarcoma virus (RSV)-transformed chicken embryo fibroblasts (CEFs) were examined by using the patch-clamp technique. Three different types of ion channels were observed with single-channel conductances in symmetrical 140 mM KCl (with frequencies of occurrence in parentheses) of 186 pS (70%), 110 pS (10%), and 65 pS (20%), which are identical in normal and RSV-transformed CEFs. The total channel density in both cell types is about 0.13 per micron2. All three types of channels are highly selective for K+ ions, they are Ca(2+)- and voltage-dependent, and they can be completely blocked by external tetraethylammonium (10 mM) in both normal and RSV-transformed cells. Some channel properties, however, are different in normal and RSV-transformed CEFs. The K186 channel of normal CEFs is almost completely activated in the presence of about 1 nM free internal Ca2+ and is insensitive to charybdotoxin (100 nM). In contrast, the K186 channel of RSV-transformed CEFs has an EC50 value for activation by internal Ca2+ of about 100 nM and is highly sensitive to charybdotoxin (IC50 = 9 nM). In normal CEFs, the K186 channel activity starts at membrane potentials more positive than -50 mV and reaches a high open state probability of 0.94 at +50 mV. In RSV-transformed CEFs, the threshold of K186 channel activity is also -50 mV but the maximal open state probability is only 0.70 at +50 mV membrane potential. Averages of current traces of K186 channels show the typical features of the macroscopic K+ currents described previously for normal and RSV-transformed CEFs.(ABSTRACT TRUNCATED AT 250 WORDS)

[Symptomatic compression of the vena cava caused by a small liver hemangioma]. / Symptomatische Kompression der Vena cava durch ein kleines Leberhämangiom.

Occasioned by a recurrent urinary infection, ultrasonography was performed on a 41-year-old otherwise healthy woman. There were no abnormal renal findings, but a 4.5 x 4.5 cm space-occupying lesion with the echo-typical pattern of an haemangioma was found in the right lobe of the liver. Magnetic resonance imaging and dynamic computed tomography demonstrated compression of the vena cava by the tumour which was localized to the caudate lobe. The T2-weighed pictures suggested a cavernous haemangioma which extended from the vena cava at the diaphragm to the portal vein bifurcation. Obstruction to flow became evident 10 months later as oedema of the lower legs, giving the indication for surgical removal of the haemangioma. The benign tumour was enucleated under total vascular occlusion without significant blood loss pre- and post-operatively. The patient was discharged symptom-free on the 13th postoperative day.

Diagnostic value of color Doppler sonography in primary liver tumors--a trend study.

In order to investigate the diagnostic value in differential diagnosis of primary liver tumors, color Doppler sonography was used preoperatively in 30 patients. Without difference, tumor hypervascularization was found in patients with hepatocellular carcinoma (2 of 4), cholangiocellular carcinoma (4 of 4), hemangioma (3 of 8), focal nodular hyperplasia (8 of 8), adenoma (3 of 4), and neuroendocrine tumor (n = 1). No vascular signal could be detected in 1 case of adenomatous hyperplasia and 2 cases of hepatocellular carcinoma, one after previous chemoembolization. Hemangioma appeared hypo- or even avascular in 5 of 8 patients. Therefore, according to our experience, the yield of color Doppler sonography is rather low for differential diagnosis and prediction of the tumor dignity. With regard to the surgical procedure, valuable information about tumor extension can be obtained particularly in central lesions close to hilar structures or liver vein confluence. Further indications result from follow-up of tumor vascularization after chemoembolization and chemotherapy.

Profound differences in potassium current properties of normal and Rous sarcoma virus-transformed chicken embryo fibroblasts.

The membrane currents of chicken embryo fibroblasts (CEFs) transformed by Rous sarcoma virus (RSV) were compared with the currents of their nontransformed counterparts by using the whole-cell patch-clamp technique. In nontransformed CEFs, the main membrane current is a delayed outward K+ current that is sensitive to tetraethylammonium ion but insensitive to 4-aminopyridine. This K+ current is almost independent of the intracellular Ca2+ concentration and becomes completely inactivated at positive membrane potentials with a time constant of about 10 s at +30 mV. In contrast, transformed CEFs exhibit a noninactivating K+ current that strongly depends on the intracellular Ca2+ concentration. This Ca(2+)-dependent K+ current is blocked by the scorpion toxin charybdotoxin with an IC50 value of 19 nM, whereas the K+ current of normal CEFs is insensitive to charybdotoxin (up to 300 nM). The K+ current properties of transformed CEFs were also found after microinjection of purified, enzymatically active pp60v-src into normal CEFs but not after infection of CEFs with the Rous-associated virus RAV5, which lacks the v-src oncogene. Our results suggest that the oncogene product pp60v-src modulates existing K+ channel proteins, leading to profound electrophysiological and pharmacological alterations of the K+ current properties in RSV-transformed CEFs. Furthermore, our experiments identify for the first time K+ channels as possible substrates of pp60v-src.

Effect of K+ channel blockers on the alpha 2-adrenoceptor-coupled regulation of electrically evoked noradrenaline release in hippocampus.

The question whether presynaptic alpha 2-adrenoceptors regulating noradrenaline release in hippocampus directly couple to tetraethylammonium chloride (TEA) or alpha-dendrotoxin (alpha-DTX)-sensitive K+ channels was investigated. Hippocampal slices, prelabelled with [3H] noradrenaline, were superfused in the presence of (+)-oxaprotiline and electrically stimulated with 4 pulses delivered at 100 Hz, in order to avoid autoinhibition due to released noradrenaline. TEA enhanced the evoked [3H]noradrenaline release in rabbit hippocampus in a concentration-dependent manner, yielding an approximately 4-fold increase at 30 mmol/l, whereas the spontaneous outflow of tritium was only slightly affected at this concentration. The alpha 2-adrenoceptor agonist clonidine, at 10-100 nmol/l inhibited the evoked [3H]noradrenaline release between 77% and 96%. The inhibitory effect of the alpha 2-agonist was distinctly diminished in the presence of 30 mmol/l TEA but was restored in low Ca2+/high Mg2+ buffer. Therefore, the diminution of the alpha 2-agonist effect by TEA observed in experiments with normal Ca2+ can be explained by an increase of the Ca2+ availability for the release process due to the prolongation of action potentials. In rabbit hippocampus alpha-DTX (10-200 nmol/l) did neither affect the evoked release of [3H]noradrenaline nor its alpha 2-agonist-induced modulation. However, in rat hippocampus alpha-DTX significantly increased the evoked transmitter release and diminished the effect of clonidine. Taken together, the present data for the rabbit hippocampus exclude the possibility that activation of presynaptic alpha 2-adrenoceptors inhibits depolarization-evoked [3H]noradrenaline release by inducing an outward K+ current through TEA- or alpha-DTX-sensitive K+ channels.(ABSTRACT TRUNCATED AT 250 WORDS)