"Big" growth hormone components from human plasma: decreased reactivity demonstrated by radioreceptor assay.

Plasma as well as pituitary immunoreactive human growth hormone (HGH) comprises at least two discrete components which have been designated as "big" HGH and "little" HGH. Using a newly developed radioreceptor assay, which depends on the ability of a substance to compete with labeled HGH for binding sites on cultured human lymphocytes, we find that the big HGH component from both normal and acromegalic subjects has much less activity in the radioreceptor assay than in the radioimmunoassay, whereas the little HGH component has simnilar activity in both assays.

Plasma clearance of intravenously administered pituitary human growth hormone: gel filtration studies of heterogeneous components.

Both pituitary and plasma human GH (hGH) comprise heterogeneous components, exhibiting similar patterns when gel filtered on Sephadex G-100. To determine at what rate the components are cleared from the circulation, blood was obtained at specific intervals following a bolus injection of pituitary hGH in hypopituitary patients. Each sample was gel filtered to determine its component profile of RIA values, which, when plotted vs. the time interval it represented, yielded a means of monitoring its disappearance from the plasma. Total hGH was cleared with a t 1/2 of 21.5 min, the little component was cleared at 19.0 min, the big component was cleared at 26.5 min, and the pre-big component was cleared at 45 min. These data indicate that the larger the hGH component, the longer it takes to be cleared from the plasma.

Evidence for higher proportion of "little" growth hormone with increased radioreceptor activity in acromegalic plasma.

Plasma growth hormone (GH) from both normal and acromegalic patients comprises multiple immunoreactive components that can be separated by G-100 Sephadex gel filtration and measured by radioimmunoassay (RIA) and radioreceptor assay (RRA). The higher molecular weight immunoreactive components, from both normal and acromegalic subjects, have a lower RRA/RIA than does the lower molecular weight "little" GH component. The "little" GH component comprises a higher proportion of the total immunoreactive GH in acromegalic plasma than in normal plasma whether the data are expressed only in terms of the "big" and "little" components (89 vs. 71%), or as a function of total immunoreactive GH (76 vs. 55%), or whether the plasma is obtained in the basal or stimulated state for the acromegalic patients. When the RRA/RIA x 100 is determined for the isolated "little" component, the acromegalic has a significantly greater ratio than the normal (110 vs. 75%). We conclude that acromegalic plasma contains a higher proportion of the more radioreceptor active "little" GH component than does the normal and, in addition, that the "little" component from the acromegalic is more radioreceptor-active than the normal.

Properties of human growth hormone polypeptides: purified from pituitary extracts and synthesized in monkey kidney cells and bacteria.

Several forms of human GH (hGH) have been elucidated by extraction of human pituitary and recombinant DNA techniques. In the present study we have characterized five of these hGH polypeptides by gel filtration, RIA, and radioreceptor assays. These include extractable pituitary hGH and its naturally occurring 20K variant. Two hGH polypeptides were produced from naturally occurring human genes in simian kidney cells (SV-hGH 1 and 2) and another preparation was produced from a partially synthesized gene in bacteria (E. coli-hGH). As predicted from their known DNA sequences, naturally occurring pituitary hGH, SV-hGH 1, and E. coli-hGH migrated as a single peak on Sephadex G-100 column and had the same immunological and receptor-binding properties. By contrast, SV-hGH 2 (14 dispersed amino acid substitutions) and the 20K variant (amino acid residues 32-46 deleted from hGH) contained more higher molecular weight components and had diminished immunological and receptor-binding potency. SV-hGH 2 differed from the 20K variant by having even lower immunological potency and containing more of the higher molecular weight component. These variant forms of hGH may provide an explanation for the heterogeneity of both pituitary and plasma hGH.

Failure of bromocriptine to alter the qualitative characteristics of human growth hormone in acromegaly.

The role of bromocriptine as a therapeutic agent for acromegaly is uncertain. In the present study we have attempted to determine whether bromocriptine therapy causes qualitative changes in plasma human growth hormone (hGH) in acromegaly. When eight paired samples obtained before and during bromocriptine therapy were filtered over Sephadex G-100 there was no difference in the elution profiles. When the "little" hGH peak from each of the eight paired samples was pooled, lyophilized, and assayed in both radioreceptor assay (RRA) and radioimmunoassay (RIA), the RRA/RIA before treatment was not different than during treatment. When bromocriptine in pharmacologically significant concentrations was incubated with cultured human lymphocytes in vitro, there was no alteration in hGH binding properties. These results demonstrate directly that bromocriptine does not change the form or receptor-reactive properties of plasma hGH and, further, that the drug does not alter at least one form of human growth-hormone receptor.

Using picture identification for research with preschool children.

Assessing preschool childrens' health knowledge and skill levels, and their recognition of health behavior, prove essential in developing and maintaining effective health education programs. However, the intent of the assessment process, and the methodology, must be carefully considered. Picture identification can be appropriately used to determine the status of a young child's health knowledge or skills and thus decide how the child might benefit from further learning experiences. Knowledge or skill assessment for young children primarily involves observing children while they demonstrate knowledge through an activity or behavior, although this assessment may be supplemented with a checklist or instrument, such as a picture identification instrument. This article 1) reviews the reliability of picture identification tools in previous studies; 2) provides recommendations for assessing health knowledge of preschool children; and 3) suggests ways health knowledge data can be used appropriately in early childhood education programs. The result of quality knowledge and skill assessment provides direction for program planners in developing appropriate health education programs for preschoolers.

Health education needs in child care programs.

This article contains results from an assessment of health education needs in child care programs serving preschool children. The assessment included identification of the scope of health education activities provided in child care programs, and the program director's perception of benefits of and barriers to health education in child care settings. A mail survey assessed the health education needs in a random sample of licensed child care programs in Alabama. Survey results identified factors affecting adoption and delivery of early childhood health education programs.

Parents' self-reported behaviors related to health and safety of very young children.

This survey documented self-reported health and safety behaviors of parents of children enrolled in Head Start programs. The sample consisted of eight preschool programs (n = 1143) from different geographical areas of the country. This survey obtained baseline data on parent self-reported behavior as it relates to priority issues in child health and safety. A 25-item questionnaire assessed parents' behavior related to injury prevention, fire and electrical safety, firearm storage, poison prevention, automobile safety, and child supervision. More than 90% of parents reported they use car seats, teach handwashing and pedestrian safety, and keep medicine and alcohol out of children's reach. Fewer than 60%, however, reported they keep guns and bullets stored separately and locked, possess a working fire extinguisher, or have the poison control telephone number available. Findings provide direction for emphasis for those developing or implementing a comprehensive family health education program.

The impact of a preschool health curriculum on children's health knowledge.

This evaluation assessed the effect of Hale and Hardy's Helpful Health Hints preschool health education curriculum on the health knowledge of children ages three-six. The sample consisted of nine experimental preschool programs (n = 194) and three comparison preschool programs (n = 73). A picture identification test assessed children's pretest and posttest health knowledge of the five senses, safety, nutrition, dental health, personal responsibility, emotions, hygiene, and drugs/medicines. Posttest knowledge scores increased by 22% among experimental group preschool programs and 12% among comparison group preschool programs. Significant differences (p less than .01) were found between experimental and comparison group students. Findings provide direction in research efforts to define conditions in which preschool health education is optimally effective.

Application of the role delineation project "Framework" to a professional preparation program.

Using the Framework for the Development of Competency-based Curricula for Entry Level Health Educators, the health education faculty at the University of Alabama at Birmingham reviewed and modified their undergraduate health education professional preparation program. Efforts focused on the five steps of preparation and study, review and organization of Framework subcompetencies, organization of Framework subcompetencies into potential courses, placement of objectives for courses, and revision of schedule and sequence for professional preparation courses. The process produced seven core courses to be required of all health education majors. A master list of subcompetencies and objectives also was developed. Faculty perceived several benefits from participating in the project.

Reliability of health knowledge measurement in very young children.

This study documented reliability of a picture identification instrument and determined its utility with young children in selected preschool programs. Three hundred eleven children, ages three-five, were selected from formal early childhood education programs in three states. A comprehensive health knowledge instrument, consisting of 30 items, was administered to all children, and a retest was administered two weeks later to a 20% randomly selected subsample. Data analysis included reliability assessments and systematic modification of the instrument. Pearson's Product Moment Correlation and Kuder Richardson 21 analyses indicated the instrument is reliable when administered individually to children ages three-five. The authors recommended this instrument, or a similar picture identification instrument, be used to assess comprehensive health knowledge.