Genetic predisposition for adult lactose intolerance and relation to diet, bone density, and bone fractures.

Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. INTRODUCTION: Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. MATERIALS AND METHODS: We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. RESULTS: Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. CONCLUSION: The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose malabsorption and osteoporosis.     

Conversational topics of 4-year-olds

Young children's ability to participate in conversation has been of particular interest in the study of pragmatic aspects of language. In this study, topics of conversation were investigated by videotaping 10 dyads of 4-year-old children during play. Ten-minute samples were analyzed according to a number of topic-dependent measures. Results revealed that all dyads evidenced some lengthy topics (13-91 utterances). Longer topics were characterized by three text-level functions. Enacting Scenarios, Describing, and Problem Solving. Nevertheless, three fourths of all dialogues were considered relatively short. Generally, partners contributed equally to dialogue, but in some dyads, 1 child dominated initiation. Findings of the study suggest that 4-year-olds are capable of extended participation in dialogue, at least part of the time. Naturalistic play settings may elicit samples of conversation that are representative of preschoolers' ability.     

Three-channel color generator for vision research

A simple, relatively inexpensive technique for adequate stimulation of the visual system is described. A combination of continuous interference filters and light fibers in one compact instrument allows individual stimulation of the color channels with narrow band light in mosaic or homogeneous compositions. Effectively all parameters of stimulation may be separately controlled and used for studies of Psycho- and Neurophysiology.     

Cardiovascular intervention for high-risk families: the Heart Smart Program

The Heart Smart Family Health Promotion Program is a multidisciplinary, school-based program for cardiovascular risk reduction among high-risk children and their families. As a program that includes young adults at high risk, it is adaptable to a clinical practice. Nineteen fourth and fifth graders were selected as probands for elevated risk factors after a general screening to identify families for an intervention program. Twenty-three parents participated in a 12-week program focused on eating, exercise, and smoking behavior changes enhanced by behavicral support strategies. Weekly sessions were held in the auditorium/cafeteria of the elementary school and consisted of orientation and presentations, cardiovascular (CV) screening with medical feedback, activities, self-monitoring, counseling, and contingency contracting. Information gathered before and after the program included medical history, CV health knowledge and relevant behavior, blood pressure, serum lipid and lipoprotein values, anthropometric measurements, and urine electrolyte excretion. Both children and parents showed positive changes in eating habits and physical activity and significant changes in knowledge and blood pressure levels, while the children halted their weight gain. We believe this multidisciplinary, behavior-oriented, school-based program can be an effective cardiovascular risk intervention adaptable for a clinical office practice.     

Association of polymorphonuclear leukocytes with sites of aortic catheter-induced injury in rabbits

The kinetics of the association of polymorphonuclear leukocytes (PMNs) with arterial balloon catheter-induced injury have been examined. An average of 6 X 10(7) PMNs were isolated from 20 ml of blood and labelled with 111In-oxine for reinfusion into the donor rabbit. The cells remained viable as demonstrated by both in vitro and in vivo tests of cell function. The abdominal aorta of rabbits was denuded of endothelium and immediately, 24 h, or 5 weeks later, exposed to autologous radiolabelled PMNs for 1 h. The presence of PMNs at sites of denudation was demonstrated by detection of the radioactive label and was confirmed by light and electron microscopy after 24 h, but not at 5 weeks. Immediately following denudation radioactivity was 2.44 +/- 0.33 times control (P = 0.006); 2.52 +/- 0.18 at 24 h (P = 0.005); and 1.88 +/- 0.32 times control at 5 weeks (P = 0.045). The presence of PMNs, or their products, 5 weeks after denudation suggests a more complex role of PMNs and possibly a direct involvement in the long term changes resulting from arterial balloon catheter injury.