Reducing the risk of eating disorders in athletics

Athletes comprise a unique population with special needs for the management and treatment of eating disorders. Prevention of these disorders also requires special approaches and strategies. Common attitudes, beliefs, and practices in athletics believed to be related to pressures to diet or to engage in pathogenic weight loss methods are discussed. Strategies for educating athletes and sport management personnel regarding issues related to eating disorders are proposed. Additionally, changes in the athletic environment designed to reduce the risk of eating disorders developing are recommended.     

The social image of smokeless tobacco use in three different types of teenagers

The current study used an unobtrusive methodology to describe the social image associated with smokeless tobacco use and with cigarette smoking in three "types" of teenage models--an athlete, a cowboy, and an average teenager. As in previous research, the social image associated with smokeless tobacco use was more positive than that associated with cigarette smoking, suggesting that adopting smokeless tobacco use may have perceived social image benefits for adolescent males. The image conveyed by smokeless tobacco use was similar across the three different types of adolescent. Relations between social image factors and tobacco use behavior were examined, and implications for tobacco use prevention are discussed.     

A human myeloma immunoglobulin G binding four moles of calcium associated with asymptomatic hypercalcemia

A calcium-binding immunoglobulin G (IgG_I^RUP) was identified in the serum of a patient with multiple myeloma, asymptomatic hypercalcemia, and a normal ionized serum calcium. Calcium binding by IgG^RUP was confirmed by two-dimensional electrophoresis with calcium-45 and equilibrium dialysis. Amino acid analyses indicated an unusually high number of glutamic (or glutamine) residues in the L chain and Fab fragment but no detectable -carboxyglutamic acid. As determined by equilibrium dialysis with⁴⁵Ca, the intact IgG^RUP and its Fab fragments bound calcium at an optimum pH of 7.4. There was minimal binding of calcium to H chains and no binding by L chains or the Fc fragment. Recombination of H and L chains partially restored the binding activity. By Scatchard analysis, the binding affinity (K _d) of IgG^RUP was 1.7×10^–3 M and the binding capacity was 4 mol of calcium/mol of IgG. The binding of 4 mol of calcium/mol of IgG is twice that reported previously for two other calcium-binding myeloma proteins and suggests unique properties of IgG^RUP.     

Inhibition of attachment of Escherichia coli RDEC-1 to intestinal microvillus membranes by rabbit ileal mucus and mucin in vitro.

Intestinal mucus is postulated to play a role in preventing colonization of the gastrointestinal tract by microbial pathogens. To evaluate the ability of both crude mucus and purified mucin, a glycoprotein of goblet cell origin, to inhibit mucosal adherence of enteric pathogens, we examined whether mucus and mucin derived from rabbit ileum interact with the rabbit enteropathogen Escherichia coli RDEC-1. We examined the manner in which mucus and mucin inhibited adherence of bacteria to rabbit ileal microvillus membranes (MVMs) in vitro. The purity of the mucin preparation was demonstrated by polyacrylamide gel electrophoresis before and after reduction and by showing that an antiserum raised to the mucin localized to goblet cells in rabbit intestine. Using radioactive labeling of bacteria, we quantitated attachment of RDEC-1 to MVMs, mucus, and mucin that had been immobilized on polystyrene microtiter wells. Binding of RDEC-1 to MVMs was also determined after preincubation of organisms with crude ileal mucus and purified mucin. RDEC-1 bound to both crude mucus and purified mucin when they expressed lectinlike adhesions, previously designated attachment factor rabbit 1 pili. Adherence of piliated RDEC-1 to MVMs, mucus, and mucin was significantly greater than when the bacteria were nonpiliated. Binding of piliated RDEC-1 to MVMs was decreased by preincubation of bacteria with both crude mucus (45.6 +/- 4.2% of control) and purified mucin (50.2 +/- 5.8%). These data indicate that the E. coli enteropathogen RDEC-1 can bind to purified glycoproteins of goblet cell origin and that adherence of these bacteria to mucin is mediated by expression of pili. The findings also support a role for intestinal mucus and its principal organic constituent, mucin, in preventing adherence of a known E. coli enteric pathogen to apical MVMs of enterocytes.     

Comparison of the hybrid capture tube test and PCR for detection of human papillomavirus DNA in cervical specimens.

The strong association of human papillomavirus (HPV) and cervical cancer makes it important to study HPV detection methods that may play a role in cervical cancer screening. We compared two DNA methods that are commonly used for HPV research in the United States: the MY09/MY11 L1 consensus primer PCR-based test and the first-generation Hybrid Capture tube method (HCT). Laboratory assays by each method were performed with 596 cervicovaginal specimens collected from participants in a large cohort study conducted in Portland, Oreg. Included were 499 specimens from women whose cytology was normal and 97 specimens from women with squamous intraepithelial lesions (SILs). The overall HPV DNA positivity for known types was 22.5% by PCR compared to 13.6% by HCT. When the analysis was restricted to the 14 HPV types detectable by both methods, the sensitivity of HCT, with PCR used as the standard for HPV status, was higher for specimens from women with concurrent SILs (81.0%) than for specimens from women with normal cytology (46.7%). Among specimens testing positive by both methods, 97.2% of the time the two methods agreed on whether specimens were positive for cancer-associated HPV types. Both of these HPV test methods provide information that supplements the information provided by the Pap smear. The PCR method has higher analytic sensitivity than HCT in detecting HPV, but HCT may be helpful in identifying women with concurrent SILs.     

Influence of testosterone on pup killing in the rat is modified by prior experience.

The usual response of the adult male rat which is placed together with newborn rat pups for the first time is to kill and eat the pups. In past experiments castration of the male blocked this behavior, and replacement therapy with testosterone propionate (TP) maintained the behavior. In the present experiments this relationship between testosterone and pup-killing behavior was modified by giving the animals prior killing or nonkilling experience. In general, experienced killers continued to kill on a retest after 30 days of testosterone deprivation, and experienced nonkillers tended not to kill on the retest even though they were given daily treatment with testosterone for thirty days prior to retesting.