8 years' experience with robotic thymectomy for thymomas.

BACKGROUND: The accuracy of a three-dimensional robotic-assisted videothoracoscopic approach may favor a radical resection of thymomas. The aim of this study was to demonstrate the feasibility of the robotic approach by reporting 8 years experience in a single referral center of surgical treatment of thymomas. METHODS: We retrospectively analyzed all consecutive patients who underwent a thymectomy from April 2004 to April 2012. We analyzed the procedure time, morbidity, mortality, conversions, hospitalization, freedom from recurrence, time to progression, and overall survival. RESULTS: From 2004 until 2012, a total of 138 robotic procedures for mediastinal tumors were performed in our center, of which 37 patients with a mean age of 57.3 years underwent a thymectomy for a thymoma. Histological analysis revealed four type A thymomas (10.8 %), seven type AB thymomas (18.9 %), seven type B1 thymomas (18.9 %), fourteen type B2 thymomas (37.8 %), four type B3 thymomas (10.8 %), and one thymus carcinoma (2.7 %). The Masaoka­Koga stages were as follows: stage I in twenty patients (54 %), stage IIA in five patients (13.5 %), stage IIB in eight patients (21.6 %), stage III in three patients (8.1 %), and stage IVa in one patient (2.7 %). The mean overall procedure time was 149 min (range 88­353). No surgical mortality was reported, and there were no peri-operative complications. No conversions were needed for surgical complications. In three cases, a conversion to sternotomy was preferred by the surgeon because tumor invasion in greater vessels was suspected. Two patients (5.4 %) suffered from a myasthenic crisis postoperatively and required prolonged mechanical ventilation. One patient (2.7 %) underwent a procedure for a thoracic herniation 6 months following thymectomy. The median hospitalization was 3 days. The follow-up analysis showed an overall survival of 100 % and tumor recurrence in one patient (2.7 %). CONCLUSIONS: Robotic thymectomies are safe in patients with early-stage thymomas. Robotic surgery may also be feasible for some selected advanced thymomas.

Generation of polyclonal antibodies directed against G protein-coupled receptors using electroporation-aided DNA immunization.

INTRODUCTION: The generation of antibodies against G protein-coupled receptors (GPCRs) can be technically challenging. A modified DNA immunization protocol was employed in order to generate polyclonal antibodies against two herpes virus-encoded GPCRs, i.e. Epstein-Barr virus (EBV) pBILF1 and rat cytomegalovirus (RCMV) pR78. METHODS: pBILF1 and pR78 expression plasmids were first injected into the tibialis anterior muscle of rats and rabbits, respectively. Subsequently, the uptake of plasmids by the muscle cells was facilitated through in vivo electroporation. RESULTS: Potent antisera against both vGPCRs were obtained, as determined by immunoblot analysis and immunofluorescence. By using the antisera, we were able to show that the EBV BILF1 protein is expressed as a 45-kD, glycosylated protein, and that it is localized in the cytoplasmic membrane of EBV-infected cells. Interestingly, we found the R78-encoded vGPCRs to have unusual perinuclear localization in both R78-transfected and RCMV-infected cells. DISCUSSION: The in vivo DNA electroporation method is a useful technique for generating antibodies against GPCRs.

Antibodies to voltage-gated potassium and calcium channels in epilepsy.

OBJECTIVE: To determine the prevalence of antibodies to ion channels in patients with long standing epilepsy. BACKGROUND: Although the CNS is thought to be protected from circulating antibodies by the blood brain barrier, glutamate receptor antibodies have been reported in Rasmussen's encephalitis, glutamic acid decarboxylase (GAD) antibodies have been found in a few patients with epilepsy, and antibodies to voltage-gated potassium channels (VGKC) have been found in a non-paraneoplastic form of limbic encephalitis (with amnesia and seizures) that responds to immunosuppressive therapy. METHODS: We retrospectively screened sera from female epilepsy patients (n=106) for autoantibodies to VGKC (Kv 1.1, 1.2 or 1.6), voltage-gated calcium channels (VGCC) (P/Q-type), and GAD. All positive results, based on the values of control data [McKnight, K., Jiang, Y., et al. (2005). Serum antibodies in epilepsy and seizure-associated disorders. Neurology 65, 1730-1735], were retested at lower serum concentrations, and results compared with previously published control data. Demographics, medical history, and epilepsy related information was gathered. RESULTS: The studied group consisted predominantly of patients with long standing drug resistant epilepsy. VGKC antibodies were raised (>100 pM) in six patients. VGCC antibodies (>45 pM) were slightly raised in only one patient. GAD antibodies were <3 U/ml in all patients. The clinical features of the patients with VGKC antibodies differed from previously described patients with limbic encephalitis-like syndrome, and were not different with respect to seizure type, age at first seizure, duration of epilepsy, or use of anti-epileptic drugs from the VGKC antibody negative patients. CONCLUSION: The results demonstrate that antibodies to VGKC are present in 6% of patients with typical long-standing epilepsy, but whether these antibodies are pathogenic or secondary to the primary disease process needs to be determined.

The negative immunoregulatory effects of fluoxetine in relation to the cAMP-dependent PKA pathway.

Recently, we have shown that various types of antidepressants, including selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, have negative immunoregulatory effects. These antidepressants suppress the interferon-gamma (IFN-gamma)/interleukin-10 (IL-10) production ratio, which is of critical importance for the determination of the capacity of immunocytes to inhibit or activate monocytic/lymphocytic functions. Since cyclic adenosine monophosphate (cAMP) production is stimulated by some antidepressants, and since cAMP inhibits IFN-gamma and stimulates IL-10 production, we postulate that the negative immunoregulatory effects of antidepressants result from their effects on the cAMP-dependent protein kinase A (PKA) pathway. The aim of the present study was to determine whether the negative immunoregulatory effects of fluoxetine may be blocked by antagonists of the cAMP-dependent PKA pathway, such as, e.g., SQ 22536, an adenylate cyclase inhibitor, and Rp-8-Br-cAMPs (Rp-isomer of 8-bromo-adenosine-3',5'-monophosphorothioate), a PKA antagonist. To this end, diluted whole blood collected from 17 normal volunteers was incubated with fluoxetine (10(-6) and 10(-5) M), with or without SQ 22536 (10(-6) and 10(-4) M) and Rp-8-Br-cAMPs (10(-6) and 10(-4) M), afterwards, IFN-gamma, IL-10 and the tumor necrosis factor alpha (TNF-alpha) were determined. Fluoxetine, 10(-6) and 10(-5) M, significantly reduced the production of IFN-gamma and TNF-alpha, and significantly decreased the IFN-gamma/IL-10 production ratio. SQ 22536 and Rp-8-Br-cAMPs were unable to block the suppressant effects of fluoxetine on the IFN-gamma/IL-10 ratio. Rp-8-Br-cAMPs, 10(-4), but not 10(-6) M, normalized the fluoxetine-induced suppression of TNF-alpha production. It is concluded that the suppressant effect of fluoxetine on the IFN-gamma/IL-10 production ratio is probably not related to the induction of the cAMP-dependent PKA pathway, whereas the suppressant effect on TNF-alpha may be related to the induction of PKA. The obtained results suggest that increased activation of the PKA-dependent pathway may constitute an important molecular basis for some (suppression of TNF-alpha production), but not all (suppression of IFN-gamma production), negative immunoregulatory effects of fluoxetine.

Pharmacokinetic-pharmacodynamic modeling of rocuronium in case of a decreased number of acetylcholine receptors: a study in myasthenic pigs.

BACKGROUND: In myasthenic patients, the sensitivity for nondepolarizing relaxants is increased and the time course of effect is prolonged due to a reduced number of functional acetylcholine receptors at the neuromuscular junction. The authors investigated both the performance of the link model proposed by Sheiner and a pharmacodynamic-pharmacokinetic model taking into account the number of unbound acetylcholine receptors in myasthenic pigs. METHODS: After obtaining the approval of the Animal Experiments Committee of their institution, the authors studied eight myasthenic pigs and eight control pigs. Myasthenia gravis was induced by injecting Torpedo acetylcholine receptors in weeks 1 and 4. On the day of the experiments, the pigs were anesthetized and intubated, and the appropriate muscles and nerves were prepared for the measurements. Rocuronium was administered by infusion to reach 90% twitch height block. Arterial blood was sampled during onset and offset of effect, and the plasma concentration of rocuronium was measured with high-performance liquid chromatography. Plasma concentration-time effect data were analyzed using two different pharmacokinetic-pharmacodynamic models, the link model according to Sheiner and a pharmacokinetic-pharmacodynamic model taking into account the unbound receptor concentration. Muscles were removed after the experiment for laboratory analysis of the acetylcholine receptor concentration. RESULTS: All eight pigs of the myasthenic group developed clinical signs of myasthenia gravis (muscle weakness) and showed increased sensitivity toward rocuronium. Pharmacokinetic modeling revealed no significant differences between myasthenic and control pigs. In pharmacokinetic-pharmacodynamic analysis, visual inspection as well as the Akaike Information Criterion (3,605 3,769) and the residual SD (3.2 3.6%) revealed a better fit for the unbound receptor model in myasthenic animals compared to the Sheiner model. Pharmacokinetic-pharmacodynamic analysis with the unbound receptor model demonstrated a decreased EC50 of 0.27 micro m (ranging from 0.17 to 0.59 micro m) compared to 2.71 micro m (ranging from 2.42 to 4.43 micro m) in control animals. The results of the Sheiner pharmacokinetic-pharmacodynamic analysis were in the same range. Both the laboratory analysis and pharmacokinetic-pharmacodynamic modeling showed a decrease in receptor concentration of more than 75%. CONCLUSION: Both the Sheiner model and the unbound receptor model may be used to fit plasma concentration-effect data of rocuronium in pigs. The unbound receptor concentration model, however, can explain the observed differences in the time course of effect, based on receptor concentration.