Abstract: A radioassay test for the rapid and sensitive determination of the concentration of monosialoglycosphingolipid G.sub.M1 ganglioside concentrations in small volumes of cerebrospinal fluid from individual patients is based on the high affinity interaction between cholera enterotoxin and G.sub.M1 ganglioside. The level of G.sub.M1 ganglioside present in the cerebrospinal fluid has been shown to be an indicator of active central nervous system pathology. In the present invention, the use of highly specific toxins eliminates cross reactivity with the other gangliosides, thereby eliminating the need to process the cerebrospinal sample prior to assay, except for centrifugation. Results of a specific application of the subject radioassay to newborn infants and older infants and children (some of the latter having active neurologic disease) indicated that the G.sub.M1 ganglioside concentration in the cerebrospinal fluid is probably a function of both central nervous system tissue ganglioside content and turnover.

Abstract: The digital switching module (DSM) is arranged as an LSI device providing digital (p.c.m.) switching for 256 channels in a space-time-space format. It is unidirectional in operation and is capable of switching data (digitally encoded speech) from any incoming channel to any outgoing channel. It is arranged to act as a building block in constructing larger digital switching networks. The DSM can be programmed to permit combinations of parallel or serial operation at input and output data interfaces, the mode being selected by the length of the pulse width of the frame start reference signal. The switching configuration of input channels to output channels is held within the DSM and can be amended by messages sent along a serial control interface. Interrogation of the switching state and of the data passing through the switch is provided by messages applied to an output control interface. The DSM can be arranged into square arrays to provide full availability switching for a greater number of channels.

Abstract: A method and composition for removing iodine and organic iodides from an iodine-containing off-gas stream is provided. The composition for the removal is a ceramic material impregnated with a mixture of a metallic salt with a water-soluble secondary amine. The method for removing the iodine and iodide is accomplished by passing the off-gas stream over the ceramic impregnated with the metallic salt-amine mixture.

Abstract: A system for administering a metered dose of nebulized antigen tests a patient's pulmonary response. The system includes a thermistor detector for sensing initiation of patient inhalation. A variable electronic timer meters the amount of nebulized antigen introduced to the patient. Safety switching means is provided for insuring against erroneous administration of more than a single dose at a time. Separate measuring equipment is used to measure pulmonary airflow resistance which will increase in response to bronchial spasm.