Teaching adolescents about changing bodies: Randomized controlled trial of an Internet puberty education and body dissatisfaction prevention program.

This study tested the efficacy of an Internet-based prevention program, Trouble on the Tightrope: In Search of Skateboard Sam, on pubertal knowledge, body esteem, and self-esteem. One hundred and ninety participants (mean age 11.6 years) were randomized to either an intervention or attention placebo control condition and were assessed at baseline, after three Internet-based sessions, and at 3-month follow-up. Although the primary hypotheses were not supported, exploratory moderator analyses indicated that the intervention was beneficial for select students. Specifically, pubertal status moderated the effects on weight-related body esteem and several domains of self-esteem, resulting in positive effects for participants in the intervention group who had begun puberty. Gender differences were found on self-esteem subscales, indicating more robust effects for girls than boys. Tailored Internet programs based on personal characteristics such as gender and pubertal status may be a fruitful area for future research with adolescents.

Nonmedical use of prescription opioids and stimulants among student pharmacists.

OBJECTIVES: To examine the prevalence and patterns of nonmedical use of prescription opioid analgesics and stimulants among student pharmacists. DESIGN: Descriptive, nonexperimental, cross-sectional study. SETTING: Private urban college of pharmacy in the United States in fall 2006. PARTICIPANTS: 1,538 PharmD students. INTERVENTION: Online survey. MAIN OUTCOME MEASURES: Lifetime and past-year nonmedical prescription opioid and stimulant use. RESULTS: Response rate for the survey was 62%. Lifetime prevalence of opioid misuse was 8%, and 5% of students had misused in the past year. Lifetime prevalence of stimulant misuse was 7%, and 5% had misused in the past year. Whites and fraternity or sorority members were more likely than their peers to have ever misused opioids. Past-year opioid misuse was more likely among whites, men, and low academic achievers compared with their peers. Lifetime stimulant misuse was more likely among students who were white, older, and fraternity or sorority members, while past-year misuse was more likely among whites and low academic achievers. Common motives for opioid misuse were to have fun, to relax, and to deal with chronic pain. Stimulants were used to improve concentration and academic performance. Friends were the most common source of prescription opioids and stimulants. Nonmedical prescription use was associated with greater likelihood of alcohol and other illicit substance use. CONCLUSION: The prevalence of prescription medication misuse among student pharmacists was lower than (opioids) or comparable with (stimulants) reported rates in college populations. Subgroups of students demonstrated higher rates of nonmedical use, including whites, students involved with fraternities or sororities, and low academic achievers. That friends were the primary source of misused medications indicates that diversion of prescription-only controlled substances likely occurs among student pharmacists. Nonmedical prescription medication use should be considered in the context of other substance use.

Reducing extracellular pH sensitizes the acinar cell to secretagogue-induced pancreatitis responses in rats.

BACKGROUND & AIMS: Protease activation within the pancreatic acinar cell is a key early event in acute pancreatitis and may require low pH intracellular compartments. Clinical studies suggest that acidosis may affect the risk for developing pancreatitis. We hypothesized that exposure to an acid load might sensitize the acinar cell to secretagogue-induced pancreatitis. METHODS: Secretagogues (cerulein, carbachol, and bombesin) can induce protease activation in acinar cells at high (100 nmol/L, 1 mmol/L, and 10 micromol/L, respectively) but not at physiologically relevant concentrations. The effects of decreasing extracellular pH (pHe) in early secretagogue-induced pancreatitis (zymogen activation and injury) were examined in rats (1) in vitro with isolated acini and (2) in vivo with an acid challenge. RESULTS: In acini, lowering pHe from 7.6 to 6.8 enhanced secretagogue-induced zymogen activation and injury, but did not affect secretion. For cerulein, this sensitization was seen over a range of concentrations (0.01-100.00 nmol/L). However, reduced pHe alone had no effect on zymogen activation, amylase secretion, or cell injury. We have reported that zymogen activation is mediated by the vacuolar ATPase (vATPase), a proton transporter. vATPase inhibition, using concanamycin (100 nmol/L), blocked the low pHe effects on zymogen activation. An acute acid load given in vivo enhanced cerulein-induced (50 microg/kg) trypsinogen activation and pancreatic edema. CONCLUSION: These studies suggest that acid challenge sensitizes the pancreatic acinar cell to secretagogue-induced zymogen activation and injury and may increase the risk for the development and severity of acute pancreatitis.

The novel protein kinase C isoforms -delta and -epsilon modulate caerulein-induced zymogen activation in pancreatic acinar cells.

Isoforms of protein kinase C (PKC) have been shown to modulate some cellular responses such as pathological secretion and generation of inflammatory mediators during acute pancreatitis (AP). We propose that PKC also participates in premature zymogen activation within the pancreatic acinar cell, a key event in the initiation of AP. This hypothesis was examined in in vivo and cellular models of caerulein-induced AP using PKC activators and inhibitors. Phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA, 200 nM), a known activator of PKC, enhanced zymogen activation at both 0.1 nM and 100 nM caerulein, concentrations which mimic physiological and supraphysiological effects of the hormone cholecystokinin, respectively, in preparations of pancreatic acinar cells. Isoform-specific PKC inhibitors for PKC-delta and PKC-epsilon reduced supraphysiological caerulein-induced zymogen activation. Using a cell-free reconstitution system, we showed that inhibition of PKC-delta and -epsilon, reduced zymogen activation in both zymogen granule-enriched and microsomal fractions. In dispersed acinar cells, 100 nM caerulein stimulation caused PKC-delta and -epsilon isoform translocation to microsomal membranes using cell fractionation and immunoblot analysis. PKC translocation was confirmed with in vivo studies and immunofluorescence microscopy in pancreatic tissues from rats treated with or without 100 nM caerulein. PKC-epsilon redistributed from an apical to a supranuclear region following caerulein administration. The signal for PKC-epsilon overlapped with granule membrane protein, GRAMP-92, an endosomal/lysosomal marker, in a supranuclear region where zymogen activation takes place. These results indicate that PKC-delta and -epsilon isoforms translocate to specific acinar cell compartments and modulate zymogen activation.

Cyclic AMP-dependent protein kinase and Epac mediate cyclic AMP responses in pancreatic acini.

The pancreatic acinar cell has several phenotypic responses to cAMP agonists. At physiological concentrations of the muscarinic agonist carbachol (1 microM) or the CCK analog caerulein (100 pM), ligands that increase cytosolic Ca(2+), cAMP acts synergistically to enhance secretion. Supraphysiological concentrations of carbachol (1 mM) or caerulein (100 nM) suppress secretion and cause intracellular zymogen activation; cAMP enhances both zymogen activation and reverses the suppression of secretion. In addition to stimulating cAMP-dependent protein kinase (PKA), recent studies using cAMP analogs that lack a PKA response have shown that cAMP can also act through the cAMP-binding protein, Epac (exchange protein directly activated by cyclic AMP). The roles of PKA and Epac in cAMP responses were examined in isolated pancreatic acini. The activation of both cAMP-dependent pathways or the selective activation of Epac was found to enhance amylase secretion induced by physiological and supraphysiological concentrations of the muscarinic agonist carbachol. Similarly, activation of both PKA or the specific activation of Epac enhanced carbachol-induced activation of trypsinogen and chymotrypsinogen. Disorganization of the apical actin cytoskeleton has been linked to the decreased secretion observed with supraphysiological concentrations of carbachol and caerulein. Although stimulation of PKA and Epac or Epac alone could largely overcome the decreased secretion observed with either supraphysiological carbachol or caerulein, stimulation of cAMP pathways did not reduce the disorganization of the apical cytoskeleton. These studies demonstrate that PKA and Epac pathways are coupled to both secretion and zymogen activation in the pancreatic acinar cell.