Case management and preventive services among infants from low-income families.

To determine the impact of an experimental approach to case management on use of child health clinic and immunization services, a nonequivalent control group with covariate measures design was employed in a sample of 98 infants from low-income families. The innovative pattern of care featured continuity of care; a single public health nurse (PHN) provided child health care to an infant by integrating case management and preventive services. In contrast, the customary pattern of child health care was characterized by fragmentation of services. Case management was segregated from preventive services, and multiple PHNs delivered care to an infant. As predicted, experimental-group infants (44%) were more likely to achieve adequate child health clinic services than control-group infants (8%) (p < 0.001). Moreover, the cost-effectiveness (C/E) ratio (dollar cost per effective intervention) for adequate child health clinic visits in continuous care ($523) was one-fifth of that in fragmented care ($2,900). The C/E ratio related to adequate immunization was 8% less in continuous care ($359) than in the fragmented approach ($386), although the difference in rates of adequate immunization was nonsignificant (experimental group, 64%; control group, 60%). These findings suggest that continuous PHN care with integrated case management is a more effective, cost-efficient approach to critical child preventive services than the customary, segregated case-management approach.

Enzymatic mass determination of high-specific-radioactivity 3H- and 14C-labeled polyunsaturated fatty acids.

The soybean lipoxygenase reaction has been applied to calculating the specific activities of 3H- and 14C-labeled polyunsaturated fatty acids of the omega 3 and omega 6 families. The extent of the soybean lipoxygenase reaction with polyunsaturated fatty acids was determined by measuring the increase in absorbance at 234 nm. A salient feature of this application of of the soybean lipoxygenase assay involves the use of a solution which contains highly purified [1-14C]arachidonic acid of known specific radioactivity as a convenient and versatile standard. Because the amount of arachidonic acid in this standard can be easily measured by liquid scintillation counting, the problems of accurately weighing liquid fatty acid standards are avoided.

Purification of the bifunctional enzyme, imidazoleglycerolphosphate dehydratase-histidinol phosphatase, of Salmonella typhimurium.

Mn2+ precipitation, antibody affinity chromatography, and selective proteolysis have been used to purify a bifunctional core of the hisB enzyme from Salmonella typhimurium. The core is homogeneous in subunit molecular weight; however, it is heterogeneous in its charge properties, probably as a result of multiple cleavage points produced by limited proteolytic digestion. The resistance of the enzyme to irreversible denaturation by urea allowed the use of urea to elute the hisB enzyme from a column of anti-hisB IgG immobilized on Sepharose. Heterogeneous oligomeric forms of the enzyme were demonstrated by electrophoretic analysis and exist as multiples of the 46,000 molecular weight monomer.