Erythrocyte membrane ATP binding cassette (ABC) proteins: MRP1 and CFTR as well as CD39 (ecto-apyrase) involved in RBC ATP transport and elevated blood plasma ATP of cystic fibrosis.

In addition to the better-known roles of the erythrocyte in the transport of oxygen and carbon dioxide, the concept that the red blood cell is involved in the transport and release of ATP has been evolving (J. Luthje, Blut 59, 367, 1989; G. R. Bergfeld and T. Forrester, Cardiovasc. Res. 26, 40, 1992; M. L. Ellsworth et al., Am. J. Physiol. 269, H2155, 1995; R. S. Sprague et al., Am. J. Physiol. 275, H1726, 1998). Membrane proteins involved in the release of ATP from erythrocytes now appear to include members of the ATP binding cassette (ABC) family (C. F. Higgins, Annu. Rev. Cell Biol. 8, 67, 1992; C. F. Higgins, Cell 82, 693, 1995). In addition to defining physiologically the presence of ABC proteins in RBCs, accumulating gel electrophoretic evidence suggests that the cystic fibrosis transmembrane conductance regulator (CFTR) and the multidrug resistance-associated protein (MRP1), respectively, constitute significant proteins in the red blood cell membrane. As such, this finding makes the mature erythrocyte compartment a major mammalian repository of these important ABC proteins. Because of its relative structural simplicity and ready accessibility, the erythrocyte offers an ideal system to explore details of the physiological functions of ABC proteins. Moreover, the presence of different ABC proteins in a single membrane implies that interaction among these proteins and with other membrane proteins may be the norm and not the exception in terms of modulation of their functions.

Overall function in rural childhood cancer survivors. The role of social competence and emotional health.

This study compared the functioning of 20 rural cancer survivors, aged 6 to 16 years, with that of 40 age- and gender-matched school peers. Social competence and emotional health were evaluated, along with academic performance and physical limitations. Eight measures were used: the teacher and parent Child Behavior Check Lists, the Health Resources Inventory, the Vineland Revised Scale of Social Maturity, the Piers-Harris Child's Self-Concept Scale, the Parcel and Meyers' Health Locus of Control, the Moos' Family Environment Scale, and the Functional Status II(r). Cancer survivors and controls had similar attitudes about self-esteem, family conflicts, physical functioning, social skills, independence, and sense of control over health. Both parents and teachers noted poorer social competence among the cancer survivors than among controls, but parents of survivors reported more behavior problems, whereas teachers stressed poorer school performance. Routine screening for emotional health, social competence, and academic performance should be part of the follow-up care of pediatric cancer survivors.

Self-reported safety practices in child care facilities.

To determine the prevalence of safety hazards and current injury prevention practices in child care settings, we administered a structured telephone interview to a geographically stratified, randomly selected sample of licensed child care facilities. Representatives of 130 child care facilities responded to questions about current injury prevention practices. Specific hazards assessed were related to burns, falls, poisoning, playgrounds, and emergency telephone numbers. Results indicated that 26.8% of providers who knew the temperature of their tap water stated that it was over 130 degrees F.; 14.1% had space heaters accessible to children; 30.3% of those with stairs accessible to children lacked safety gates; 61.4% of those with playgrounds did not have an impact-absorbing surface under playground equipment; 16.9% of respondents had an unexpired bottle of syrup of ipecac; 55.8% demonstrated that a poison control center telephone number was available to them; and 80% of providers could demonstrate the availability of the telephone number of the local ambulance. We conclude that potential and remedial injury hazards exist in some licensed child care centers and that providers of child care within licensed facilities are a promising target for childhood injury prevention interventions.

Digital deformity: an effect of frostbite in children.

Two young children, aged 2 1/2 and 3 1/2, were briefly exposed to temperatures of -20 degrees F (-29 degrees C) without adequate hand protection. Hand contact with snow and metal doorknobs also occurred. Second and third degree frostbite of the cold injured digits ensured. Within six months, and progressing thereafter, the fingers developed a stubby appearance and demonstrated distal angulation and weak extension. Roentgenograms revealed undermineralization of the phalanges and coarsening of the trabecular pattern. The epiphyses of the middle and distal epiphyses were absent or atrophic. The metaphyses were irregularly convoluted. The pathogenesis of this deformity appears to be the direct effect of freezing and of ischemia on the most metabolically active site in the digit--the growth plate.

Comparison of large and small child-resistant containers.

Two studies, a 13-month prospective survey and a clinical trial, were conducted to evaluate how children less than 5 years of age opened children's aspirin (small container) and chewable multi-vitamin (large container) bottles. In study one, teeth were used to open a closed children's aspirin container in greater than 50% of reported exposures compared to 5% for reported multivitamin exposures. A clinical trial (study two) revealed an interaction between the child's age and the characteristics of the container (F = 2.83, df = 6,28; P less than 0.05). Larger containers were harder to open in the hands of a 23-28 month old child while smaller containers were harder to open in the 32-38 month age group. Neither container were more easily opened by children between 29 and 31 months of age. These results suggest that container characteristics and a child's age are both variables which may influence future poison prevention activities.