Blending chitosan with polycaprolactone: porous scaffolds and toxicity.

The preparation and characterization of porous scaffolds from chitosan-PCL blends by freeze extraction, freeze gelation and freeze drying is reported. Using freeze extraction, stable structures were obtained only from PCL, but these were not porous. No stable scaffolds were obtained using the freeze gelation process. Stable scaffolds of chitosan/PCL mixtures could not be obtained using 77% acetic acid by any of these techniques. With 25% aqueous acetic acid, stable scaffolds of chitosan/PCL mixtures were obtained by the freeze drying technique. The stability and pore morphology of freeze dried scaffolds were dependent on the relative mass ratio of chitosan and PCL. A chorioallantoic membrane assay showed that formed 3D chitosan/PCL mixtures were not toxic to vasculature.

[Alterations of gait parameters under external cueing in schizophrenic patients: a switch study]. / Veränderungen von Gangparametern unter externer Triggerung bei schizophrenen Patienten: eine Umstellungsuntersuchung.

Schizophrenic disorders as well as neuroleptic treatment can affect locomotion. The study assessed the influence of neuroleptic treatment on externally triggered gait on a treadmill at three different velocities via ultrasonic topometric gait analysis. Spatial and temporal gait parameters were assessed in two groups of schizophrenic patients either under treatment with conventional neuroleptics (n = 12) or without neuroleptic treatment (n = 10) and re-assessed after treatment change to the atypical neuroleptic olanzapine in a repeated measures design. After switch from conventional neuroleptics to olanzapine patients showed an increase of step length and decrease of cadence at the low (p

[3-D ultrasound-assisted gait analysis of schizophrenic patients. Comparison between conventional neuroleptics and olanzapine]. / Dreidimensionale ultraschallgestützte Ganganalyse bei schizophrenen Patienten. Vergleich zwischen konventionellen Neuroleptika und Olanzapin.

Schizophrenic disorders as well as neuroleptic treatment can affect locomotion. The study assessed the influence of neuroleptic treatment on human gait via ultrasonic topometric gait analysis. In a control sample the test system proved high test-retest-reliability. Spatial and temporal gait parameters were assessed in schizophrenic patients without neuroleptic treatment (n = 12) and under treatment with conventional neuroleptics (n = 14) and re-assessed after treatment change to the atypical neuroleptic olanzapine in a repeated measures design. After switch from conventional neuroleptics to olanzapine patients showed an increase of gait velocity (p < or = 0.01) and step length (p < or = 0.01) whereas the cadence remained stable. Significant differences between the untreated state and treatment with olanzapine were not detectable. We conclude that bipedal gait is affected by conventional neuroleptic treatment. The degree of impairment can be objectively measured by testing spatio-temporal and kinematic gait parameters via three-dimensional ultrasonic gait analysis.

[Three-Dimensional Ultrasonic Gait Analysis in Schizophrenic Patients] / Dreidimensionale ultraschallgestützte Ganganalyse bei schizophrenen Patienten - Vergleich zwischen konventionellen Neuroleptika und Olanzapin -

Schizophrenic disorders as well as neuroleptic treatment can affect locomotion. The study assessed the influence of neuroleptic treatment on human gait via ultrasonic topometric gait analysis. In a control sample the test system proved high test-retest-reliability. Spatial and temporal gait parameters were assessed in schizophrenic patients without neuroleptic treatment (n = 12) and under treatment with conventional neuroleptics (n = 14) and re-assessed after treatment change to the atypical neuroleptic olanzapine in a repeated measures design. After switch from conventional neuroleptics to olanzapine patients showed an increase of gait velocity (p

Arsenic stimulates angiogenesis and tumorigenesis in vivo.

Trivalent inorganic arsenic (arsenite, arsenic trioxide, As[III]) is currently being used to treat hematologic tumors and is being investigated for treating solid tumors. However, low concentrations of As(III) stimulate vascular cell proliferation in cell culture, although this has not been confirmed in vivo. Therefore, the hypothesis that As(III) enhances blood vessel growth (angiogenesis) and tumorigenesis was tested in two in vivo models of angiogenesis and a model of tumor growth. In the first, arsenite caused a dose-dependent increase in vessel density in a chicken chorioallantoic-membrane (CAM) assay. The threshold As(III) concentration for this response was 0.033 microM and inhibition of vessel growth was observed at concentrations greater than 1 microM. Mouse Matrigel implants were used to test the angiogenic effects of As(III) in an adult mammalian system. Mice were injected with 0.8-80 microg/kg As(III)/day over a three-week period. During the last two weeks, Matrigel plugs were placed on the abdominal wall. Low and high doses of As(III) were synergistic with fibroblast growth factor-2 (FGF-2) in increasing vessel density in the Matrigel assay, while a middle dose had no effect. To test the effects of As(III) on tumor growth, GFP-labeled B16-F10 mouse melanoma cells were implanted in nude mice, which subsequently received biweekly injections of 0.5-5.0 mg/kg As(III). Significant tumor growth and lung metastasis was seen in all animals, with the largest tumors occurring in animals treated with lower doses of As(III). These studies support the hypothesis and indicate that induction of angiogenesis, enhanced tumor growth, and metastasis are potential dose-dependent toxic side effects of arsenic therapies.