Preface.

In this issue of Health Psychology is a summary of discussions and presentations conducted at the National Working Conference on Research in Health and Behavior, Harpers Ferry, West Virginia, May 1988. Conceived by Richard Evans in 1985, the idea for this conference reflected both the substantial growth in this scientific endeavor and the recognition that the ways in which the field evolves are shaped in part by those active in it. The reports and summaries that appear in this issue do not reflect an exhaustive report of these deliberations. Rather, selected articles are presented along with task force (i.e., working group) reports in order to provide a hint of the context in which the task forces addressed their topics. Each of the keynote speakers (Richard Evans and Karen Matthews) was asked to provide a summary of remarks, and each panel agreed to provide one or more articles summarizing individual or group conclusions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduction of charge injection into PECVD SiNxHy by control of deposition chemistry

The high rate of charge trapping in thin-film silicon nitride causes its electrical properties to change with stressing level and time. The rate of shift of the high-frequency CV curves of Al/SiN_xH_y/cSi capacitors was used here to measure nitride charging rate and to compare PECVD nitrides deposited under various conditions of plasma power and gas mixture in the same parallel-plate reactor. By operating the plasma under high power to activate the NH₃ or N₂ and under low SiH₄ flow to ensure that all of the SiH4 reacts with N, it is possible to deposit N-rich nitride that has no detectable Si—H bonding, which bonding others have correlated with charge trapping. Nitride deposited under these conditions using NH₃ and 13 MHz rf power had charging rates for both gate polarities that were 20 times lower than those of nitride that had a “stoichiometric” N/Si ratio of 4/3 and that had its H distributed among Si—H and N—H bonds. MIS capacitors made with the latter nitride also had a high negative initial flat-bond voltage, indicating the presence of grown-in positive charge. This charge was large enough to invert the surface ofp-Si substrates. N-rich nitride free of Si—H that was deposited either using N₂ or using low-frequency rf power (≤400 kHz) had higher charging rates than did that deposited from NH₃ at 13 MHz. Also, the low-frequency material contained grown-in positive charge that is attributed to H⁺ implanted by the high ion bombardment energy of the low-frequency plasma.     

Management of Heparin‐Induced Thrombocytopenia During Renal Replacement Therapy

Awareness is increasing concerning the development of antibodies to heparin–platelet factor 4 complex in both regular hemodialysis patients and those treated with continuous forms of renal replacement therapy. Although the development of antibodies does not result in thrombocytopenia or thrombosis in some patients, most patients present with thrombocytopenia, premature platelet activation, and clotting of the extracorporeal circuit. When systemic anticoagulation is also required to treat venous thrombosis, then synthetic heparinoids or recombinant hirudin will be the agents of choice. However, neither the synthetic heparinoids nor hirudin are without problems. A few patients may have cross‐reacting antibodies against the currently available heparinoids. Similarly, antibodies may develop against recombinant hirudin, leading to a potentiation of anticoagulant activity and increased risk of hemorrhage. In the future, thrombin inhibitors such as recombinant hirudin and the arginine derivative argatroban will probably be the agents most widely used to prevent thromboembolic complications. However, anti‐platelet agents used alone or in combination with hirudin or synthetic heparinoids may provide adequate treatment by inhibiting both platelet and clotting cascade activation.     

Serious conduct problems in the children of adolescent mothers: Disentangling confounded correlations.

Early motherhood (r?=?.33) with the number of Diagnostic and Statistical Manual of Mental Disorders (DSM-III) symptoms of conduct disorder in a sample of 253 boys (aged 6–13 yrs) who had been referred to outpatient clinics. The following models were compared using path analysis: (1) Teenage motherhood, parental antisocial personality, and socioeconomic status (SES) each contribute uniquely to the prediction of childhood conduct problems; (2) teenage motherhood mediates the association of SES and parental antisocial personality with child conduct problems; and (3) teenage motherhood is spuriously related with child conduct problems because of common associations with SES and parental antisocial personality. Model (3) best fit the data. Similar results were obtained whether maternal age at the birth of the firstborn child or the proband child was used to define maternal age and when teenage motherhood was defined as giving birth at     

Pharmacokinetics of nicotine carbomer enemas: a new treatment modality for ulcerative colitis

BACKGROUND: Ulcerative colitis is largely a disease of nonsmokers, and transdermal nicotine is of therapeutic value in the active disease. Because side effects are common, we developed a topical enema formulation of nicotine. OBJECTIVE: To study the pharmacokinetics of nicotine complexed with a polyacrylic carbomer and administered by enema to eight healthy volunteers and to eight patients with active ulcerative colitis, verified sigmoidoscopically. PATIENTS AND METHODS: All 16 subjects were nonsmokers. The mean age for normal subjects was 33 years; the mean for patients with ulcerative colitis was 60 years. Median stool frequency for patients with ulcerative colitis was four daily. Patients were taking 5-amino salicylic acid compounds and five were taking oral prednisolone (median dose, 12 mg daily). Nicotine, 6 mg, complexed with carbomer 974P, 400 mg, was administered in a 100 ml enema after an overnight fast, with serial blood measurements taken over 8 hours. Serum nicotine and cotinine were measured by gas liquid chromatography. Area under the concentration-time curves were calculated by the trapezoidal method, and the terminal elimination half-life was derived by extrapolation of the log-linear terminal phase. RESULTS: With the exception of nicotine time to reach peak concentration, which was longer in patients (median of 60 minutes compared with 45 minutes; p < 0.005), other comparisons between normal subjects and patients showed no statistically significant difference, although there was considerable inter-subject variation. Maximum concentration of nicotine, 8.1 +/- 3.5 ng/ml, in the 16 subjects occurred after a median of 60 minutes (range, 30 to 180 minutes); maximum cotinine concentrations of 60.4 +/- 11.5 ng/ml occurred after 4 hours. Side effects in five subjects were mild (four subjects) or moderate (one subject) and included lightheadedness, nausea, and headache; these five subjects were female lifelong nonsmokers of low body weight. CONCLUSION: Because most of the active ingredient of nicotine is converted to continine on the first pass through the liver, substantial concentrations can be achieved at the site of disease with only modest rises in serum nicotine, which are responsible for side effects; cotinine has low pharmacologic activity. Topical administration of nicotine may be useful treatment for distal ulcerative colitis.