Landmark identification accuracy in xeroradiographic cephalometry.

Identification accuracy of fourteen cephalometric landmarks was compared between xeroradiographic cephalograms and conventional cephalograms. Four landmarks--point A, upper incisor tip, infradentale, and menton--were more accurately determined on the xeroradiograph, while two landmarks--point B and condylion--were more accurately determined on the conventional cephalogram. Although not conclusively demonstrated in this study, the xeroradiograph does appear to offer more clarity and detail than the conventional cephalogram. Further investigation of this new diagnostic medium will be necessary before its true significance to dentistry can be evaluated.     

How to create a continuous learning system

The use of the problem-oriented record as a tool which accompanies the problem-oriented system makes it possible to assess what we are doing. It makes it possible, among many other things, to learn more from what we do. It is, I believe, the key to the solution of many problems that plague us and the key to an improved continuing educational system. The implementation will require the efforts of many organizations, including the American Heart Association, the American College of Cardiology, American College of Physicians, American College of Chest Physicians and others. This is what I believe it will take to really —I mean really—teach cardiology. This is true because cardiology must be taught within the framework of a learning system. It cannot be learned outside the context of a learning system.     

The emergency treatment of poisoning in children.

The various methods commonly used to reduce the amount of a poison that will be absorbed from the alimentary tract are evaluated according to safety, speed of action, effectiveness and patient acceptability. The conclusion is reached on the evidence available that syrup of ipecacuanha is the method of choice in the routine emergency treatment of childhood poisonings. The indications for other methods are defined.     

Automated estimation of sodium, potassium, and calcium using the Eppendorf flame photometer

An Eppendorf flame photometer may be used to estimate sodium, potassium, and calcium in plasma which has been automatically sampled and diluted. Readings may be automatically recorded by feeding the output from the photomultiplier into a sensitive recorder. This method estimates 60 samples an hour, using approximately 0.12 ml. plasma per estimation. The accuracy of the method is discussed.     

Effect of Secondary Metabolites on the Organisms Producing Them: Effect of Nisin on Streptococcus lactis and Enterotoxin B on Staphylococcus aureus

The effect of secondary metabolites added to cultures of the organisms producing them was investigated. Nisin was added to growing cultures of a nisin-producing strain of Streptococcus lactis (354/07) and enterotoxin B to strains of Staphylococcus aureus (S6 and 243) producing enterotoxin B. One quarter (12 mug/ml) of the amount of nisin formed by the culture of S. lactis inhibited lag-phase cells and lysed log-phase cells. The same amount of nisin added before inoculation or at a time when nisin synthesis had started (in late log phase), caused only transient delay in growth. Inhibition of growth of the two enterotoxin B-producing strains of S. aureus could not be demonstrated at any stage of their growth cycle with as much as 1 mg of enterotoxin B per ml of medium.