Risk Factors for Course of Posttraumatic Stress Disorder Among Vietnam Veterans: A 14-Year Follow-Up of American Legionnaires.

Risk factors affecting the course of posttraumatic stress disorder (PTSD) are poorly understood. As part of a larger study on characterizing exposure to herbicides in Vietnam, the authors investigated this issue in a random sample of 1,377 American Legionnaires who had served in Southeast Asia during the Vietnam War and were followed over a 14-year period. High combat exposure, perceived negative community attitudes at homecoming, minority race, depression symptoms at Time 1, and more anger at Time 1 predicted a more chronic course. Community involvement at Time 1 was protective and associated with decreased risk at Time 2. Discomfort in disclosing Vietnam experiences was associated with an increased risk for developing PTSD but did not predict its course. Combat exposure predicted PTSD course more strongly than any other risk factor. Findings suggest recovery from PTSD is significantly influenced by perceived social support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endoscopic visualization of induced colonic tumors in rats

The visualization of induced colonic tumors in rats was investigated using either a rigid or flexible endoscope. There was 89% agreement between presence or absence of at least one tumor as visualized at endoscopy and necropsy. The agreement was 83% (p < 0.01) when the exact number of tumors was compared. Neither carcinogens (1,2-dimethylhydrazine or N-methylnitrosourea) nor dietary supplements affected the results.     

Gender differences relative to smoking behavior and emissions of toxins from mainstream cigarette smoke.

This study examined whether gender differences exist in the exposure to select mainstream cigarette smoke toxins as a result of differences in smoking behavior or type of cigarettes smoked among 129 female and 128 male smokers. Smoking topography data indicated that, compared with men, women took smaller puffs (37.6 ml/puff vs. 45.8 ml/puff; p = .0001) of shorter duration (1.33 s/puff vs. 1.48 s/puff; p = .002) but drew more puffs per cigarette (13.5 vs. 12.0; p = .001) and left longer butts (36.3 mm or 40.2% of cigarette length vs. 34.3 mm or 39.2% of cigarette length; p = .01). These trends were similar in both African Americans and European Americans. The emissions of select toxins per cigarette, as determined by mimicking human smoking behaviors were greater among the male smokers than the female smokers and correlated significantly with delivered smoke volume per cigarette. The geometric means of emissions of nicotine from cigarettes were 1.92 mg/cigarette (95% CI = 1.80-2.05) for women versus 2.20 (95% CI = 2.04-2.37) for men (p = .005). Cigarettes smoked by women yielded 139.5 ng/cigarette of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK; 95% CI = 128.8-151.0), compared with 170.3 ng/cigarette (95% CI = 156.3-185.6) for men (p = .0007); benzo(a)pyrene (BaP) emissions were 18.0 ng/cigarette (95% CI = 17.0-19.0) for women and 20.5 ng/cigarette (95% CI = 18.8-22.3) for men (p = .01). The gender differences with regard to cigarette smoke yields of toxins were more profound in European Americans than in African Americans. On average, African American men's smoking habits produced the highest emissions of select toxins from cigarettes, and European American female smokers had the lowest exposure to carcinogens and toxins. Several studies have suggested that women may be more susceptible than men to the ill effects of carcinogens in tobacco and tobacco smoke, whereas other studies have not found differences in lung cancer risk between men and women. The present study suggests that gender differences in exposure to tobacco smoke cannot account for a higher rate of lung cancer in female smokers compared with male smokers.     

Tobacco smoking, cancer and social class

Consumption of tobacco products, both by smoking and by other means, has long been causally connected with cancers of the lung, larynx, mouth and pharynx, oesophagus, bladder, and many other sites. Tobacco is the main specific contributor to total mortality in many developed countries and has become a major contributor in the developing countries as well. In most industrialized countries, prevalence of cigarette smoking is currently higher in low than in high social classes, although in some industrialized countries smoking was more frequent in high social classes during the first half of this century. The latter pattern of tobacco consumption is more likely to apply to developing countries. To formulate and carry out effective tobacco control activities it is essential to assess the relative incidence of tobacco-related cancers in different social strata and the prevalence of tobacco use across strata. Despite many years of data gathering the information base is far from complete, especially in developing countries where tobacco use is increasing rapidly, and where aggressive marketing by the transnational tobacco industry is occurring. A critical question is the extent to which tobacco usage can 'explain' the observed social class differences in cancer risk. Class differences in lung cancer are likely to be mostly related to the unequal distribution of tobacco smoking between social classes, and in some fairly simple situations this has been satisfactorily demonstrated. Nevertheless, there are many unresolved issues, especially with regard to the role of collateral exposures, such as hazardous occupations, poor diet, and limited access to health care. The question of whether tobacco use 'explains' socioeconomic differences in one or more of the cancers that it causes has rarely been directly addressed in epidemiological studies.     

Mentholated cigarettes and smoking habits in whites and blacks

OBJECTIVE: To determine if cigarette mentholation is associated with the frequency of smoking and with quitting, and whether mentholation explains racial differences in these two smoking behaviours. DESIGN: Cross sectional analysis of case-control data on smoking and lung cancer. SUBJECTS: Limited to 19 545 current and former cigarette smokers. MAIN OUTCOME MEASURES: Smoking > 20 cigarettes per day (cpd) versus < or = 20 cpd, and continued smoking versus quit smoking. RESULTS: Among blacks, the prevalence odds ratio (POR) of heavy smoking (> or = 21 cpd) associated with mentholated cigarettes versus non-mentholated cigarettes was 0.7 (95% confidence interval (CI) 0.5 to 0.9) in current smokers and 0.6 (95% CI 0.4 to 0.9) in former smokers. Among whites, the corresponding POR were 0.9 (95% CI 0.8 to 1.0) and 0.9 (95% CI 0.8 to 1.0). Blacks were less likely to have been heavy smokers than whites, but the difference was unrelated to cigarette mentholation. The POR of continued smoking versus quitting, associated with mentholated cigarettes was 1.1 (95% CI 1.0 to 1.2) for both blacks and whites. CONCLUSION: Smoking > 20 cpd was independently associated with white race. Among blacks, smoking < or = 20 cpd was independently associated with mentholated cigarettes. The risk of quitting was not associated with cigarette menthol flavour.     

Parakeets, canaries, finches, parrots and lung cancer: no association

OBJECTIVES: Shortening hospital stay yet not compromising quality of care can result in significant cost savings for children undergoing surgical correction of vesicoureteral reflux. METHODS: We reviewed the medical records of pediatric patients who underwent ureteroneocystostomy between July 1995 and July 1997. A total of 43 patients, aged 0.2 to 18 years (mean 5.2) who all received identical postoperative care, except for their pain management and the time of bladder catheter removal, were included in the study. Twenty-three were treated with intravenous ketorolac tromethamine (Toradol); the remaining 20 received narcotics in the immediate postoperative period. The bladder catheter was removed in less than 24 hours in 22 children, and greater than 24 hours in 21. RESULTS: Patients who received ketorolac tromethamine for postoperative analgesia had on average shorter hospital length of stays than those treated with narcotics (1.4 versus 2.5 days, respectively; P < 0.001). The average stay for children whose bladder catheter was removed within 24 hours postoperatively was significantly shorter than those whose catheter was removed after a 24-hour period (1.4 versus 2.4 days, respectively; P < 0.001). There were no reimplantation failures. One child presented 2 days postoperatively with anemia, which did not require transfusion. CONCLUSIONS: Our review demonstrates that ketorolac tromethamine can be used safely and effectively in children for immediate postoperative analgesia, and that its proper use combined with early catheter removal can reduce the length of hospital stay for pediatric patients undergoing ureteroneocystostomy.     

Dynamics of Nanostructured Origami

The nanostructured origami approach to 3-D nano manufacturing is a novel way to gain functionality from the third dimension in nanotechnology applications. After first patterning devices onto a structural membrane using traditional 2-D tools, the segments can be folded along predefined creases in order to realize a final shape in 3-D. In order to manufacture increasingly complex devices, knowledge of the origami's dynamics is imperative. This paper describes a method to model the dynamics of two types of origamis using methods that were originally developed for use in robotic manipulation tasks. The stability of the devices in the folded state is also discussed.     

Application of three-dimensional interactive graphics in X-ray crystallographic analysis

A program called XpY was written for the PDP-10/LDS-1 at the Princeton University Computer Graphics Laboratory, for generating and displaying models of dinucleoside phosphates. The molecule GpC, a member of this class and a fragment of the nucleic acid RNA, was subjected to X-ray diffraction analysis.The paper describes the importance of model building in X-ray analysis, and shows step by step how XpY was used to deduce the atomic coordinates of GpC from the experimental data. The program documentation is also included as an Appendix.A subjective critique of graphics is made in the Conclusions section.     

Airborne emissions from 1961 to 2004 of benzo[a]pyrene from U.S. vehicles per km of travel based on tunnel studies

We identified 13 historical measurements of polycyclic aromatic hydrocarbons (PAHs) in U.S. vehicular traffic tunnels that were either directly presented as tailpipe emission factors in microg per vehicle-kilometer or convertible to such a form. Tunnel measurements capture fleet cruise emissions. Emission factors for benzo[a]pyrene (BaP) for a tunnel fleet operating under cruise conditions were highest prior to the 1980s and fell from more than 30-microg per vehicle-km to approximately 2-microg/km in the 1990s, an approximately 15-fold decline. Total annual U.S. (cruise) emissions of BaP dropped by a lesser factor, because total annual km driven increased by a factor of 2.7 during the period. Other PAH compounds measured in tunnels over the 40-year period (e.g., benzo[ghi]perylene, coronene) showed comparable reduction factors in emissions. PAH declines were comparable to those measured in tunnels for carbon monoxide, volatile organic compounds, and particulate organic carbon. The historical PAH "source terms" determined from the data are relevant to quantifying the benefits of emissions control technology and can be used in epidemiological studies evaluating the health effects of exposure, such as those undertaken with breast cancer in New York State.