Factors improving the vibration transfer of the floating mass transducer at the round window

With the placement of a floating mass transducer (FMT) at the round window, a new approach of coupling an implantable hearing system to the cochlea has been introduced. The aim of the present experimental study is to examine the influence of different ways of FMT placement at the round window on the vibration energy transfer to the cochlea.

Long-term safety of intramuscular gene transfer of non-viral FGF1 for peripheral artery disease

Peripheral artery disease is a progressive disease. Primary ischemic leg symptoms are muscle fatigue, discomfort or pain during ambulation, known as intermittent claudication. The most severe manifestation of peripheral artery disease is critical limb ischemia (CLI). The long-term safety of gene therapy in peripheral artery disease remains unclear. This four center peripheral artery disease registry was designed to evaluate the long-term safety of the intramuscular non-viral fibroblast growth factor-1 (NV1FGF), a plasmid-based angiogenic gene for local expression of fibroblast growth factor-1 versus placebo in patients with peripheral artery disease who had been included in five different phase I and II trials. Here we report a 3-year follow-up in patients suffering from CLI or intermittent claudication. There were 93 evaluable patients, 72 of them in Fontaine stage IV (47 NV1FGF versus 25 placebo) and 21 patients in Fontaine stage IIb peripheral artery disease (15 NV1FGF versus 6 placebo). Safety parameters included rates of non-fatal myocardial infarction (MI), stroke, death, cancer, retinopathy and renal dysfunction. At 3 years, in 93 patients included this registry, there was no increase in retinopathy or renal dysfunction associated with delivery of this angiogenic factor. There was also no difference in the number of strokes, MI or deaths, respectively, for NV1FGF versus placebo. In the CLI group, new cancer occurred in two patients in the NV1FGF group. Conclusions that can be drawn from this relatively small patient group are limited because of the number of patients followed and can only be restricted to safety. Yet, data presented may be valuable concerning rates in cancer, retinopathy, MI or strokes following angiogenesis gene therapy in the absence of any long-term data in angiogenesis gene therapy. It may take several years until data from larger patient populations will become available.

Gene transfer of hepatocyte growth factor by electroporation reduces bleomycin-induced lung fibrosis

Abnormal alveolar wound repair contributes to the development of pulmonary fibrosis after lung injury. Hepatocyte growth factor (HGF) is a potent mitogenic factor for alveolar epithelial cells and may therefore improve alveolar epithelial repair in vitro and in vivo. We hypothesized that HGF could increase alveolar epithelial repair in vitro and improve pulmonary fibrosis in vivo. Alveolar wound repair in vitro was determined using an epithelial wound repair model with HGF-transfected A549 alveolar epithelial cells. Electroporation-mediated, nonviral gene transfer of HGF in vivo was performed 7 days after bleomycin-induced lung injury in the rat. Alveolar epithelial repair in vitro was increased after transfection of wounded epithelial monolayers with a plasmid encoding human HGF, pCikhHGF [human HGF (hHGF) gene expressed from the cytomegalovirus (CMV) immediate-early promoter and enhancer] compared with medium control. Electroporation-mediated in vivo HGF gene transfer using pCikhHGF 7 days after intratracheal bleomycin reduced pulmonary fibrosis as assessed by histology and hydroxyproline determination 14 days after bleomycin compared with controls treated with the same vector not containing the HGF sequence (pCik). Lung epithelial cell proliferation was increased and apoptosis reduced in hHGF-treated lungs compared with controls, suggesting increased alveolar epithelial repair in vivo. In addition, profibrotic transforming growth factor-beta1 (TGF-beta1) was decreased in hHGF-treated lungs, indicating an involvement of TGF-beta1 in hHGF-induced reduction of lung fibrosis. In conclusion, electroporation-mediated gene transfer of hHGF decreases bleomycin-induced pulmonary fibrosis, possibly by increasing alveolar epithelial cell proliferation and reducing apoptosis, resulting in improved alveolar wound repair.

Sensitive and highly specific quantitative real-time PCR and ELISA for recording a potential transfer of novel DNA and Cry1Ab protein from feed into bovine milk

To address food safety concerns of the public regarding the potential transfer of recombinant DNA (cry1Ab) and protein (Cry1Ab) into the milk of cows fed genetically modified maize (MON810), a highly specific and sensitive quantitative real-time PCR (qPCR) and an ELISA were developed for monitoring suspicious presence of novel DNA and Cry1Ab protein in bovine milk. The developed assays were validated according to the assay validation criteria specified in the European Commission Decision 2002/657/EC. The detection limit and detection capability of the qPCR and ELISA were 100 copies of cry1Ab microL(-1) milk and 0.4 ng mL(-1) Cry1Ab, respectively. Recovery rates of 84.9% (DNA) and 97% (protein) and low (<15%) imprecision revealed the reliable and accurate estimations. A specific qPCR amplification and use of a specific antibody in ELISA ascertained the high specificity of the assays. Using these assays for 90 milk samples collected from cows fed either transgenic (n = 8) or non-transgenic (n = 7) rations for 6 months, neither cry1Ab nor Cry1Ab protein were detected in any analyzed sample at the assay detection limits.

Maternal transfer of IgE and subsequent development of IgE responses in the horse (Equus callabus)

Immunoglobulin E (IgE) mediates the immune response to parasites, but can also cause allergies. In humans maternal IgE is not transferred to cord blood and high levels of cord blood IgE are associated with subsequent allergy. In horses, both maternal IgG and IgE are transferred via colostrum; the IgE levels in the mare's serum, the colostrum and the foal's serum are correlated but the consequences of IgE transfer to foals are not known. By about 6 weeks of age the levels of IgE in foal serum have dropped to a nadir, at 6 months of age the level of IgE has risen only very slightly and is no longer correlated with the levels seen at birth, IgE(+) B-cells could be detected in lymphoid follicles of some foals at this age. Surprisingly, the levels of total IgE detected in a foals serum at 6 months of age are significantly correlated with the level in its serum at 1, 2 and even 3 years of age suggesting that by 6 months of age the foals are synthesizing IgE and that a pattern of relatively higher or lower total serum IgE has been established. The neonatal intestinal mucosa contained connective tissue mast cells which stained for bound IgE in foals up to 9 weeks of age but not mucosal mast cells, thereafter, the intestinal mast cells were IgE negative until 6 months of age. IgE antibodies to Culicoides nubeculosus salivary antigens were detected in Swiss born foals from imported Icelandic mares allergic to Culicoides spp. yet the foals showed no signs of skin sensitization and such second generation foals are known not to have an increased risk of developing allergy to Culicoides. Overall this evidence suggests there is a minimal effector role of maternal IgE also that maternal IgE has waned prior to the onset of IgE synthesis in foals and does not support maternal priming of IgE responses in foals. Furthermore the total levels of IgE in any given foal are seen to be relatively high or low from soon after the onset of IgE synthesis, and most likely they are determined by genetic factors.

Targeted gene transfer of hepatocyte growth factor to alveolar type II epithelial cells reduces lung fibrosis in rats

Inefficient alveolar wound repair contributes to the development of pulmonary fibrosis. Hepatocyte growth factor (HGF) is a potent growth factor for alveolar type II epithelial cells (AECII) and may improve repair and reduce fibrosis. We studied whether targeted gene transfer of HGF specifically to AECII improves lung fibrosis in bleomycin-induced lung fibrosis. A plasmid encoding human HGF expressed from the human surfactant protein C promoter (pSpC-hHGF) was designed, and extracorporeal electroporation-mediated gene transfer of HGF specifically to AECII was performed 7 days after bleomycin-induced lung injury in the rat. Animals were killed 7 days after hHGF gene transfer. Electroporation-mediated HGF gene transfer resulted in HGF expression specifically in AECII at biologically relevant levels. HGF gene transfer reduced pulmonary fibrosis as assessed by histology, hydroxyproline determination, and design-based stereology compared with controls. Our results indicate that the antifibrotic effect of HGF is due in part to a reduction of transforming growth factor-β(1), modulation of the epithelial-mesenchymal transition, and reduction of extravascular fibrin deposition. We conclude that targeted HGF gene transfer specifically to AECII decreases bleomycin-induced lung fibrosis and may therefore represent a novel cell-specific gene transfer technology to treat pulmonary fibrosis.