A gated electronic switch for stimulation and recording with a single electrode
A circuit design is described for an electronic device which is gate controlled to rapidly switch electrode connections between a stimulator and an amplifier. An integrated switch in the circuit is operated by transistor-transistor logic pulses and will conduct analog signals of up to 15 V amplitude. Electrographic records made using the switch show multi-unit spike discharge after repetitive stimulation of the amygdala in the kindled rat.
Cyclic nucleotides in the amygdala of the kindled rat
The basolateral amygdala of rats was stimulated once daily until three successive fully kindled seizures were elicited. Twenty-four hours after the last seizure the rats were sacrificed by focused microwave irradiation to the head. Tissues from homolateral and contralateral amygdala and cerebral cortex were assayed for cAMP and cGMP content. No significant changes in cyclic nucleotides were measured in the kindled animals. These studies indicate that long term changes in the steady-state level of total tissue cyclic nucleotides do not occur concomitant with the persistently altered excitability associated with kindling of the amygdala.
Amphotericin B microspheres: A therapeutic approach to minimize toxicity while maintaining antifungal efficacy
Amphotericin B microsphere formulations with and without addition of polyethylene glycol 2000 in cross-linked bovine serum albumin were prepared. Amphotericin B microspheres were characterized for particle size (<5 µm), zeta potential (∼30 mV) and drug interaction by DSC and FTIR and were found to be stable formulations. Drug release profiles for these microspheres revealed that the release was primarily by diffusion. In vitro toxicity as assessed by release of haemoglobin and potassium demonstrated no toxic effect as compared with conventional solution formulation. Antifungal activity in vitro was comparable to solution formulation when tested by broth dilution method.