l-citrulline prevents asymmetric dimethylarginine-mediated reductions in nitric oxide and nitrosative stress in primary human airway epithelial cells.

BACKGROUND: Asthma is associated with reduced systemic levels of l-arginine and increased asymmetric dimethylarginine (ADMA). This imbalance leads to nitric oxide synthase (NOS) uncoupling with reduced nitric oxide (NO) formation and greater oxidative and nitrosative stress. Whether this imbalance also occurs in bronchial epitheliumof asthmatics is unknown. OBJECTIVES: We used primary human bronchial epithelial cells (HBECs) from asthmatics and healthy controls to evaluate: (i) ADMA-mediated NOS uncoupling reduces epithelial production of NO and increases oxygen and nitrogen reactive species, and (ii) l-citrulline can reverse this mechanism by recoupling NOS, restoring NO production and reducing oxidative and nitrosative stress. RESULTS: In HBECsIL-13 and INFγ stimulated NOS2 and increased NOx levels. The addition of ADMA reduced NOx and increased H2 O2 levels (p<0.001). Treatment with l-citrulline (800, 1600 µm) rescued NOx when the l-arginine media concentration was 25 µm but failed to do so with higher concentrations (100 µm). Under reduced l-arginine media conditions, HBECs treated with l-citrulline increased the levels of argininosuccinate, an enzyme that metabolizes l-citrulline to l-arginine. l-citrulline prevented the ADMA-mediated increase in nitrotyrosine in HBECs in cells from asthmatics and controls. CONCLUSIONS AND CLINICAL RELEVANCE: Increasing ADMA reduces NO formation and increases oxidative and nitrosative stress in airway epithelial cells. l-citrulline supplementation restores NO formation, while preventing nitrosative stress. These results, suggest that l-citrulline supplementation may indeed be a powerful approach to restore airway NO production and may have a therapeutic potential in diseases in which there is a defective production of NO.

Determination of rare earth elements in tomato plants by inductively coupled plasma mass spectrometry techniques.

In recent years identification of the geographical origin of food has grown more important as consumers have become interested in knowing the provenance of the food that they purchase and eat. Certification schemes and labels have thus been developed to protect consumers and genuine producers from the improper use of popular brand names or renowned geographical origins. As the tomato is one of the major components of what is considered to be the healthy Mediterranean diet, it is important to be able to determine the geographical origin of tomatoes and tomato-based products such as tomato sauce. The aim of this work is to develop an analytical method to determine rare earth elements (RRE) for the control of the geographic origin of tomatoes. The content of REE in tomato plant samples collected from an agricultural area in Piacenza, Italy, was determined, using four different digestion procedures with and without HF. Microwave dissolution with HNO3 + H2O2 proved to be the most suitable digestion procedure. Inductively coupled plasma quadrupole mass spectrometry (ICPQMS) and inductively coupled plasma sector field plasma mass spectrometry (ICPSFMS) instruments, both coupled with a desolvation system, were used to determine the REE in tomato plants in two different laboratories. A matched calibration curve method was used for the quantification of the analytes. The detection limits (MDLs) of the method ranged from 0.03 ng g(-1) for Ho, Tm, and Lu to 2 ng g(-1) for La and Ce. The precision, in terms of relative standard deviation on six replicates, was good, with values ranging, on average, from 6.0% for LREE (light rare earth elements) to 16.5% for HREE (heavy rare earth elements). These detection limits allowed the determination of the very low concentrations of REE present in tomato berries. For the concentrations of REE in tomato plants, the following trend was observed: roots > leaves > stems > berries.

Comparison of different analytical procedures in the determination of trace elements in lichens.

A BCR standard reference material of lichen (CRM 482) was used to validate an analytical procedure consisting of a microwave oven digestion associated with ICP-OES, ICP-MS and GFAAS techniques for the analysis of trace elements (Al, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn) in biomonitor samples. Two different acid mixtures were used: (a) 7 ml of HNO3, 1 ml of H2O2; (b) 7 ml of HNO3, 1 ml of H2O2 and 200 microl of HF; all digestions were carried out using 100-250 mg samples brought to a final volume of 50 ml. The validation of the procedure was carried out by two laboratories in terms of accuracy and precision; the former was estimated as percentage recovery by comparing experimental data with certificate values; the latter evaluated according to ISO standard 5725. Real lichen samples were analysed too with the procedures above described. In certified CRM 482 and real lichen samples the procedure with HF showed higher recovery values for Al, Ti, V, Ba and Fe than the procedure without HF. For all the other elements the two procedures gave comparable results both in terms of accuracy and precision. The recovery obtained with HF procedure for all the elements was generally better than 90-103%.

A controlled randomized response technique.

The randomized response survey technique appears to be suitable for studies of sensitive sexual behaviors, particularly in AIDS-related research. However, existing methods provide only estimates of group statistics, not of individual information. Additionally, the popular "unrelated question" approach requires the knowledge of the parameters of the unrelated question. In this article, a variation of the unrelated-question method is suggested for use. Specifically, it is suggested that the unrelated question be one to which the response is known to be "yes." Through this "controlled" approach, the raw data become a direct linear transformation of the response to the sensitive question, and thus can be used directly in regression and other analyses at the individual score level. The estimation of the parameters for the unrelated question is not necessary and the hesitation to provide a "yes" response found in the "forced choice" method is minimized.

Factors influencing selected heterosexual male college students' condom use.

This study assessed selected heterosexual male college students' use of condoms, their reasons for using condoms, and their attitudes toward sexuality and condoms. Three hundred five male subjects completed a questionnaire that assessed class standing, marital status, reasons for using condoms, number of recent sexual partners, intention to use condoms, and attitudes toward sexuality and condoms. Although no relationship between attitudes toward sexuality and attitudes toward condoms was noted, a negative correlation (-.42) was found between attitude toward condoms and intention to use condoms within the next month if the subject were to have intercourse during that time. Recommendations for increasing condom use are presented.

PIP: The prevalence of condom use, the reasons condoms are selected, and attitudes toward condoms and sexuality were investigated in a sample of 305 heterosexual male students at Virginia Polytechnic Institute. 72% of respondents reported that they had used a condom at least once. Of the 219 students reporting a history of condom use, 27 (12%) did so primarily to prevent the spread of sexually transmitted diseases and 164 (75%) were mainly concerned with preventing pregnancy. The subjects' mean score on a attitudes toward condoms scale was 67.89 (the scale ranged from 21-105), suggesting that the overall attitude toward condoms was neither positive nor negative. The lowest score on the scale was for the statement, "condoms are pleasant to use," while the highest score was for the item, "I would have no objection if my partner suggested that we use a condom." On the other hand, the statement, "I would avoid using condoms if at all possible," received widespread acceptance. The only significant correlation between attitudinal items and condom use was that males who intended to use condoms within the next month were more likely to have a positive attitude toward condom use. 2 of the findings of this study have implications for contraceptive education programs among young men. 1st, there is a need for greater emphasis on the prophylactic function of condom use. 2nd, given the finding that most students were willing to use condoms if pressured by their female sexual partners, programs should be designed to encourage women students to suggest or even provide condoms to their male partners.

Using LISREL analysis for drug research.

LISREL Analysis is suggested as a method of modeling relationships among variables to determine causality. LISREL is a computer program that uses a maximum-likelihood procedure to analyze structural equations. The variables in the tested hypotheses can be both directly observed variables and latent variables. LISREL was applied to the findings of a study in drug education research in order to provide a model. The constructed LISREL model was contrasted with the ANOVA-based model. The LISREL had greater explanatory value for dealing with antecedent variables present in complex human health behaviors.

Precise determination of strontium isotope ratios by TIMS to authenticate tomato geographical origin.

Thermal Ionisation Mass Spectrometry (TIMS) was applied to discriminate a total of 118 tomato samples (berries, "passata", tinned tomatoes, sauce, double and triple concentrate) coming from two different countries. The TIMS technique gave significantly different results for the (87)Sr/(86)Sr ratios and δ‰ values between Chinese and Italian tomato samples, irrespective of the treatment type. This technique proved to be a "robust" method, suitable for a precise discrimination of the two geographical origins. TIMS was able, within the Italian samples, to discriminate different geographical production areas, by virtue of different (87)Sr/(86)Sr ratios and δ‰ values. This technique could be employed in the field of food safety and quality, as a profitable tool for authenticating tomato geographical origin.

Demographic and practice characteristics of chiropractors.

The purpose of this study was to determine the demographic and practice characteristics of chiropractors. A four-part survey questionnaire was developed and mailed to a national stratified (by state) random sample of chiropractors. The analysis of data revealed that most chiropractors hold an undergraduate degree, practice in an urban area, are licensed to practice in only one state, belong to their state's chiropractic association, and are active in continuing education. Other data analyzed related to income, sources of new patients and average fees charged.