Abstract: A method for determining the concentration of an unknown bacterial solution using only a single bacterial growth plate for the determination. The method comprises depositing a varying amount of bacterial solution on the surface of a solidified agar plate by continuously varying the amount of solution deposited in the shape of a spiral on the agar which is in a rotating Petri dish. Thus, a higher concentration of bacteria per unit length occurs at the center of the spiral and a decreasing concentration per unit length at the edge of the plate. The plate is then incubated and the colonies in a predetermined area of the plate are counted in order to determine the concentration of the unknown solution. The bacterial colonies in a predetermined area may be counted by interrupting a light or laser beam incident to a photodiode, the light being interrupted by the presence of a bacterial colony.

Abstract: The use of catalytic hydrogenolysis to selectively deblock protected moieties in sulfur containing compounds has not been a practical process due to poisoning of the catalyst by the sulfur compound. It has now been found that catalytic hydrogenolysis of sulfur compounds can be successfully carried out by conducting the reaction in liquid ammonia as solvent.

Abstract: An automatic filtering apparatus which provides an aliquot of filtrate of a particular quantity desired is provided. A solid-liquid mixture is introduced to a filter means under positive air pressure to provide the liquid filtrate. The filtrate flows into a receiving means defining the volume of the particular quantity desired. Excess filtrate flows into an overflow reservoir and out a waste line connected thereto. The filtrate in the receiving means can be transferred into a delivery means. Advantageously, a three-way stop-cock is disposed between the filter receiving means and delivery means and the flow paths are determined by the position of the stop-cock.

Abstract: A nuclease-resistant hydrophilic complex of polyriboinosinic-polyribocytidylic acid, poly-1-lysine and carboxymethylcellulose, and injectable preparations thereof in a pharmaceutically acceptable aqueous carrier such as saline solution. When administered to a non-human primate host, the complex is effective in inducing the synthesis in such host of antiviral levels of interferon.

Abstract: An electrode assembly for amperometric analysis of amperometrically inactive material including an enzyme for converting the inactive material to one which is amperometrically active. The enzyme is in chemically bound form to provide improved stability and is held in contact with the electrode by means of a permeable membrane.

Abstract: A method and apparatus for continuous mixing of blood plasma with additives, such as alcohol, comprises an elongated cylindrical chamber with inner and outer coolant chambers disposed adjacent thereto with an intermediate product chamber containing an impeller. Plasma and at least one additive are introduced into the product chamber in the vicinity of the impeller which mixes the blood plasma and additives. The blood plasma and additives then flow through the product chamber where they are cooled by a refrigerant flowing in the inner and outer cooling chambers. The mixed and cooled blood plasma and additives then flow from an outlet in the product chamber. A method is disclosed of continuously supplying a flow of blood plasma and desired additives in predetermined proportions and mixing and cooling the continuous flow of the combined blood plasma and additives.

Abstract: An esophageal transducer measures pressure due to esophageal contractions. The transducer is inserted into the esophagus at the end of a catheter. The transducer is fully contained within a housing at the end of the catheter and is capable of measuring pressure variations at all points about its entire circumference. The housing has a flexible portion extending around its entire circumference which encloses a fluid-filled section. The fluid of the fluid-filled section contacts a pressure-sensitive piezoelectric material which produces an electrical output indicative of pressure changes in the fluid-filled section.

Abstract: Extracts obtained from boiling displaced tree sap to dryness have significant anti-P388 mouse leukemia activity in mice.