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Inhalant use among antisocial youth: prevalence and correlates.

The current (2.9%), annual (19.6%), and lifetime (34.3%) prevalence of inhalant use among 475 youth (M age = 15.5; SD = 1.5; 87.4% male) on probation in a western state of the United States was assessed. Inhalant users reported significantly less family support and cohesiveness and lower self-esteem, and significantly more lifetime thoughts of suicide and suicide attempts, neighborhood gang activity, peer and parental substance abuse, intentions to engage in illegal behavior, substance-related criminality, and substance abuse than did nonusers. Ethnicity, self-esteem, suicidality, number of substance-using peers, and extent of substance-related criminality significantly discriminated inhalant users from nonusers in a logistic regression analysis. Multiple linear regression analyses indicated that age, perceived school ability, age at initiation of alcohol use, self-esteem, and substance-related criminality significantly predicted age at onset of inhalant use (R2 = .30). Age at initiation of inhalant use, gang membership, truancy, and substance-related criminality significantly predicted lifetime frequency of inhalant use (R2 = .20). Study findings indicate that inhalant-using delinquents evidence significantly greater antisocial attitudes, personal and familial dysfunction, and substance abuse, than do their non-inhalant-using counterparts.

Administration, Inhalation↗

Physical and biological predictors of changes in whole-lung function following thoracic irradiation.

PURPOSE: To develop methods of predicting the pulmonary consequences of thoracic irradiation (RT) by prospectively studying changes in pulmonary function following RT. METHODS AND MATERIALS: 100 patients receiving incidental partial-lung irradiation during treatment of tumors in or adjacent to the thorax had whole-lung function assessed via symptoms and pulmonary function tests (PFTs: FEV1-forced expiratory volume 1 s; DLCO-diffusion capacity) before and repeatedly 6-48 months following RT. All had computed tomography-based three-dimensional (3D) dose calculations with lung density heterogeneity corrections for dose-volume histogram (DVH) and normal tissue complication probability (NTCP) calculations. Functional DVHs (DVfH) based on SPECT (single photon emission computed tomography) lung perfusion scans, and serial transforming growth factor-beta (TGF-beta1) levels were available in 50 and 48 patients, respectively. The incidence and severity of changes in whole-lung function were correlated with clinical, physical, and biological factors. Exploratory statistical analyses were performed using chi-square, Pearson correlations, logistic regression, and multiple linear regression. RESULTS: RT-induced symptoms developed in 21 patients. In the overall group, the single best predictor for the development of symptoms was the NTCP (p < 0.05). Pre-RT PFTs alone were less predictive (p = 0.1 for FEV1, p = 0.08 for DLCO). A multivariate model based on pre-RT DLCO and CT-based NTCP was strongly predictive for the development of symptoms (p < 0.001). NTCPs based on SPECT-derived DVf Hs and TGF-beta1 levels did not appear to provide additional predictive value. The presence or absence of pulmonary symptoms was correlated with the decline in PFT 6 months following RT (p < 0.05). In the overall group, the degree of decline in PFTs was not well correlated with any of the dose-volume variables considered. In patients with "good" pre-RT PFTs, there was a relationship between the percent reduction in PFT and dose-volume parameters such as the percent of lung volume receiving > 30 Gy (p < 0.05). CONCLUSION: The extent of alteration in whole-lung function (symptoms or PFT changes) appears to be related to both dose-volume and pre-RT PFT parameters. The data suggest that no one variable is likely to be an adequate predictor and that multivariate predictive models will be needed. Additional studies are underway to develop better predictive models that consider physical factors such as the DVH and regional perfusion, as well as biological/clinical factors such as pre-RT PFTs and TGF-beta1.

Adult↗

Cigarette smoking, environmental tobacco smoke exposure and insulin sensitivity: the Insulin Resistance Atherosclerosis Study.

PURPOSE: To investigate whether active smoking and/or exposure to environmental tobacco smoke (ETS) is associated with insulin sensitivity. METHODS: Insulin sensitivity and tobacco use history were measured in 1481 participants in the Insulin Resistance Atherosclerosis Study (IRAS). IRAS is a large mulitcenter epidemiologic study designed to explore the cross-sectional relationships among insulin resistance, cardiovascular disease risk factors and behaviors, and disease in African-American, Hispanic, and non-Hispanic white men and women, aged 40-69 years, selected to represent a broad range of glucose tolerance. Multiple linear regression models and linear contrasts were employed to describe the association between smoking history, as assessed via structured interview, and insulin sensitivity, as assessed by an insulin modified frequently sampled intravenous glucose tolerance test (FSIGT) with minimal model analysis. RESULTS: Active smoking was not associated with insulin sensitivity. Exposure to ETS was associated with lower insulin sensitivity. Specifically, for all participants combined, levels of SI were lower, indicating reduced insulin sensitivity, for those exposed to ETS when compared to those who were not exposed (p = 0.019). This association persisted for female participants (p = 0.013) and exhibited the same trend for males but failed to achieve statistical significance (p = 0.264). CONCLUSIONS: Our study did not reveal an association between active smoking and insulin sensitivity, as has been shown previously. The association between ETS exposure and insulin sensitivity is a puzzling finding which deserves further investigation in the longitudinal data from IRAS as well as in other populations.

Adult↗

Sex reassignment: outcomes and predictors of treatment for adolescent and adult transsexuals.

BACKGROUND: We prospectively studied outcomes of sex reassignment, potential differences between subgroups of transsexuals, and predictors of treatment course and outcome. METHOD: Altogether 325 consecutive adolescent and adult applicants for sex reassignment participated: 222 started hormone treatment, 103 did not; 188 completed and 34 dropped out of treatment. Only data of the 162 adults were used to evaluate treatment. Results between subgroups were compared to determine post-operative differences. Adults and adolescents were included to study predictors of treatment course and outcome. Results were statistically analysed with logistic regression and multiple linear regression analyses. RESULTS: After treatment the group was no longer gender dysphoric. The vast majority functioned quite well psychologically, socially and sexually. Two non-homosexual male-to-female transsexuals expressed regrets. Post-operatively, female-to-male and homosexual transsexuals functioned better in many respects than male-to-female and non-homosexual transsexuals. Eligibility for treatment was largely based upon gender dysphoria, psychological stability, and physical appearance. Male-to-female transsexuals with more psychopathology and cross-gender symptoms in childhood, yet less gender dysphoria at application, were more likely to drop out prematurely. Non-homosexual applicants with much psychopathology and body dissatisfaction reported the worst post-operative outcomes. CONCLUSIONS: The results substantiate previous conclusions that sex reassignment is effective. Still, clinicians need to be alert for non-homosexual male-to-females with unfavourable psychological functioning and physical appearance and inconsistent gender dysphoria reports, as these are risk factors for dropping out and poor post-operative results. If they are considered eligible, they may require additional therapeutic guidance during or even after treatment.

Adolescent↗

A new approach to near-infrared spectral data analysis using independent component analysis.

This paper presents a new approach to near-infrared spectral (NIR) data analysis that is based on independent component analysis (ICA). The main advantage of the new method is that it is able to separate the spectra of the constituent components from the spectra of their mixtures. The separation is a blind operation, since the constituent components of mixtures can be unknown. The ICA based method is therefore particularly useful in identifying the unknown components in a mixture as well as in estimating their concentrations. The approach is introduced by reference to case studies and compared to other techniques for NIR analysis including principal component regression (PCR), multiple linear regression (MLR), and partial least squares (PLS) as well as Fourier and wavelet transforms.

Adipose Tissue↗

ADME evaluation in drug discovery. 4. Prediction of aqueous solubility based on atom contribution approach.

A novel method for the estimation of aqueous solubility was solely based on simple atom contribution. Each atom in a molecule has its own contribution to aqueous solubility and was developed. Altogether 76 atom types were used to classify atoms with different chemical environments. Moreover, two correction factors, including hydrophobic carbon and square of molecular weight, were used to account for the inter-/intramolecular hydrophobic interactions and bulkiness effect. The contribution coefficients of different atom types and correction factors were generated based on a multiple linear regression using a learning set consisting of 1290 organic compounds. The obtained linear regression model possesses good statistical significance with an overall correlation coefficient (r) of 0.96, a standard deviation (s) of 0.61, and an unsigned mean error (UME) of 0.48. The actual prediction potential of the model was validated through an external test set with 21 pharmaceutically and environmentally interesting compounds. For the test set, a predictive r=0.94, s=0.84, and UME=0.52 were achieved. Comparisons among eight procedures of solubility calculation for those 21 molecules demonstrate that our model bears very good accuracy and is comparable to or even better than most reported techniques based on molecular descriptors. Moreover, we compared the performance of our model to a test set of 120 molecules with a popular group contribution method developed by Klopman et al. For this test set, our model gives a very effective prediction (r=0.96, s=0.79, UME=0.57), which is obviously superior to the predicted results (r=0.96, s=0.84, UME=0.70) given by the Klopman's group contribution approach. Because of the adoption of atoms as the basic units, our addition model does not contain a "missing fragment" problem and thus may be more simple and universal than the group contribution models and can give predictions for any organic molecules. A program, drug-LOGS, had been developed to identify the occurrence of atom types and estimate the aqueous solubility of a molecule.

Drug Design↗

Modeling the sensory impact of defined combinations of volatile lipid oxidation products on fishy and metallic off-flavors.

The volatiles (E,Z)-2,6-nonadienal, 1-penten-3-one, (Z)-4-heptenal, and (E,E)-2,4-heptadienal were added to milk containing 1.5% fat according to a central composite design, to evaluate the individual and combinatory effects of these volatiles on sensory properties. The milk samples with added volatiles were subjected to sensory descriptive analysis for fishy and metallic off-flavors. The data were analyzed using partial least-squares regression and multiple linear regression to develop mathematical models. The models revealed significant main effects of (E,Z)-2,6-nonadienal and 1-penten-3-one and highlighted the importance of two-factor interactions for contribution toward off-flavors. The results suggest that (E,Z)-2,6-nonadienal and 1-penten-3-one could be useful markers for fishy and metallic off-flavors in fish oil and fish oil enriched foods. Within the addition levels of the volatiles there was a curvature effect of (E,Z)-2,6-nonadienal, a compensatory effect of (Z)-4-heptenal and (E,E)-2,4-heptadienal, and a synergistic effect of (E,Z)-2,6-nonadienal and (Z)-4-heptenal in the development of fishy off-flavors.

Aldehydes↗

Assessing potential for recovery of biotic richness and indicator species due to changes in acidic deposition and lake pH in five areas of southeastern Canada.

Biological damage to sensitive aquatic ecosystems is among the most recognisable, deleterious effects of acidic deposition. We compiled a large spatial database of over 2000 waterbodies across southeastern Canada from various federal, provincial and academic sources. Data for zooplankton, fish, macroinvertebrate (benthos) and loon species richness and occurrence were used to construct statistical models for lakes with varying pH, dissolved organic carbon content and lake size. pH changes, as described and predicted using the Integrated Assessment Model (Lam et al., 1998; Jeffries et al., 2000), were based on the range of emission reductions set forth in the Canada/US Air Quality Agreement (AQA). The scenarios tested include 1983, 1990, 1994 and 2010 sulphate deposition levels. Biotic models were developed for five regions in southeastern Canada (Algoma, Muskoka, and Sudbury, Ontario, southcentral Quebec, and Kejimkujik, Nova Scotia) using regression tree, multiple linear regression and logistic regression analyses to make predictions about recovery after emission reductions. The analyses produced different indicator species in different regions, although some species showed consistent trends across regions. Generally, the greatest predicted recovery occurred during the final phase of emission reductions between 1994 and 2010 across all taxonomic groups and regions. The Ontario regions, on average, were predicted to recover to a greater extent than either southcentral Quebec or the Kejimkujik area of Nova Scotia. Our results reconfirm that pH 5.5-6.0 is an important threshold below which damage to aquatic biota will remain a major local and regional environmental problem. This damage to biodiversity across trophic levels will persist well into the future if no further reductions in sulphate deposition are implemented.

Acid Rain↗

Predictors of baseline peritoneal transport status in Australian and New Zealand peritoneal dialysis patients.

BACKGROUND: Factors that predict peritoneal transport status in peritoneal dialysis (PD) patients are poorly understood. The aim of the present study is to determine these factors in Australian and New Zealand incident PD patients. METHODS: The study included all patients on the Australian and New Zealand Dialysis and Transplant Registry who started PD therapy between April 1, 1991, and March 31, 2002, and underwent a peritoneal equilibration test (PET) within the first 6 months. Predictors of peritoneal transport category and dialysate-plasma creatinine ratio at 4 hours (D-P Cr 4h) were assessed by multivariate ordinal logistic regression and multiple linear regression, respectively. RESULTS: A total of 3,188 patients were studied. Mean D-P Cr 4h was 0.69 +/- 0.13. High transport status was associated with older age (adjusted odds ratio [OR], 1.08 for each 10 years; 95% confidence interval [CI], 1.03 to 1.13), Maori and Pacific Islander racial origin (OR, 1.48; 95% CI, 1.13 to 1.94), and normal body mass index (BMI; < 18.5 kg/m2: OR, 0.90; 95% CI, 0.65 to 1.24; BMI of 18.5 to 25 kg/m2: OR, 1 [reference]; BMI of 25 to 30 kg/m2: OR, 0.81; 95% CI, 0.70 to 0.95; BMI > 30 kg/m2: OR, 0.71; 95% CI, 0.58 to 0.86), but was not independently predicted by sex, diabetes, other comorbid diseases, smoking, previous hemodialysis therapy or transplantation, or residual renal function. Similar results were found when peritoneal permeability was modeled as a continuous variable (D-P Cr 4h). CONCLUSION: In Australian and New Zealand PD patients, higher peritoneal transport status is independently associated with racial origin, older age, and lower BMI. The diversity of peritoneal transport characteristics in different ethnic populations suggests that additional validation of PET measurements in various racial groups and study of their relationship to patient outcomes are warranted.

Adult↗

Determination of preload-recruitable stroke work and elastance by the relationship of arterial blood flow velocity to left ventricular area.

OBJECTIVE: The authors investigated the feasibility of an online sampling and display of LV flow-area loops for the determination of LV elastance and preload-recruitable stroke work (PRSW). Automated LV area measurements by echocardiography may be combined with flow velocity measurements in the internal carotid artery to construct LV flow-area loops as estimates of the systolic pressure-volume relationship. SETTING: University hospital. DESIGN: Open chest model. PARTICIPANTS: Eight anesthetized minipigs. INTERVENTIONS: Inferior vena cava occlusion was performed to simultaneously obtain parameters of the LV flow-area relationship and the LV pressure-area relationship. MEASUREMENTS AND MAIN RESULTS: Parameters were obtained at baseline and during sequential administration of dobutamine (5 microg/kg/min) and halothane (0.8 vol%). Linear regression analysis and analysis of variance were performed to investigate an underlying linear relationship between the corresponding variables. Highly linear elastance and PRSW curves were derived from the flow-area and pressure-area loops (n = 24, R >/= 0.85). Changes of the curve slopes indicated inotropic changes as well as model independent dP/dt(max). Elastance from the pressure-area relationship was expressed by elastance from the flow-area relationship by the term y = 0.52 + 0.04. x (R(2) = 0.84; p < 0.0001). Linear regression of PRSW as derived from the flow-area relationship with PRSW as derived from the pressure-area relationship was expressed by y = 0.43 + 0.02. x (R(2) = 0.77; p < 0.0001). CONCLUSION: Indices of the LV pressure-area relationship can be derived from real-time loops constructed from arterial flow velocity and LV area.

Anesthetics, Inhalation↗

Predictors of anxiety and depression following pregnancy termination: a longitudinal five-year follow-up study.

BACKGROUND: The aims of the study were to assess anxiety and depression in women who had experienced either a miscarriage or an induced abortion, to compare the women's level of distress with that of a general population sample, and to find predictors of anxiety and depression six months and five years after the event. METHODS: A prospective, longitudinal follow-up study. Women who experienced miscarriage (n = 40) and induced abortion (n = 80) were interviewed ten days (T1), six months (T2), two years (T3), and five years (T4) after the event. On each occasion, they completed the Hospital Anxiety and Depression Scale and the Life Events Scale. Paired-sample t-test, logistic regression, and multiple linear regression statistical tests were used. RESULTS: Women with miscarriage had significantly more anxiety and depression at T1 than the general population, while women with induced abortion had significantly more anxiety at all time points and more depression at T1 and T2. In both groups, important predictors of anxiety and depression at T2 and T4 were recent life events and poor former psychiatric health. Childbirth events between T1 and T4 had no significant influence on the scores. For women with induced abortion, doubt about the decision to abort was related to depression at T2 (p <0.05), while a negative attitude towards induced abortion was associated with anxiety at T2 (p <0.05) and T4 (p <0.05). CONCLUSION: Correlates of anxiety and depression may be used to better identify women who are at risk of negative psychological responses following pregnancy termination.

Abortion, Induced↗

Tonsillectomy, high dose immunoglobulins, and cyclophosphamide in progressive IgA-nephropathy.

In progressive IgA-nephropathy (IgAN) no established therapy exists. We have analyzed the clinical course of 40 patients with progressive IgAN with tonsillectomy combined with cyclophosphamide (TE/CTX), high dose immunoglobulins (IVIG), or cyclophosphamide pulses (CyP), and 8 untreated patients as historical controls. Serum creatinine >250 micromol/l at beginning, proteinuria >2.5 g/l, and age >51 years were significant predictors for end stage renal failure in Cox regression analysis. In linear regression analysis, the decline of renal function significantly decreased only in patients after CyP from 29.7% per year to 2.8% per year. Proteinuria significantly decreased only in patients after CyP from 1.3 g/l to 1.1 g/l. IVIG had no maintained long term effect on renal function, and TE/CTX had no significant influence on renal function. In Kaplan Meier analysis, patients with CyP had a significantly higher cumulative probability of renal survival compared to the other patients. In conclusion, TE/CTX is not recommended in patients with advanced, progressive IgAN, if not surgically indicated. IVIG had no long-term effect on progression of IgAN. CyP therapy is able to stop the loss of renal function and decreases proteinuria in patients with progressive IgAN.

Cyclophosphamide↗

Comparison of different methods to define regions of interest for evaluation of regional lung ventilation by EIT.

The measurement of regional lung ventilation by electrical impedance tomography (EIT) has been evaluated in many experimental studies. However, EIT is not routinely used in a clinical setting, which is attributable to the fact that a convenient concept for how to quantify the EIT data is missing. The definition of region of interest (ROI) is an essential point in the data analysis. To date, there are only limited data available on the different approaches to ROI definition to evaluate regional lung ventilation by EIT. For this survey we examined ten patients (mean age +/- SD: 60 +/- 10 years) under controlled ventilation. Regional tidal volumes were quantified as pixel values of inspiratory-to-expiratory impedance differences and four types of ROIs were subsequently applied. The definition of ROI contours was based on the calculation of the pixel values of (1) standard deviation from each pixel set of impedance data and (2) the regression coefficient from linear regression equations between the individual local (pixel) and average (whole scan) impedance signals. Additionally, arbitrary ROIs (four quadrants and four anteroposterior segments of equal height) were used. Our results indicate that both approaches to ROI definition using statistical parameters are suitable when impedance signals with high sensitivity to ventilation-related phenomena are to be analyzed. The definition of the ROI contour as 20-35% of the maximum standard deviation or regression coefficient is recommended. Simple segmental ROIs are less convenient because of the low ventilation-related signal component in the dorsal region.

Algorithms↗

Fighting for each segment: estimating the clinical value of cervical and thoracic segments in SCI.

Patients suffering from complete spinal cord injury (SCI) are the most likely candidates for the application of new interventions for neural repair and regeneration. It is assumed that some of these treatments will have their strongest impact at the segmental level. Therefore, it is important to evaluate the clinical relevance of potential changes at the segmental levels concerning both improvement and deterioration. Data of 98 motor complete SCI patients were derived from the European Multicenter Study of Human Spinal Cord Injury database. Six months after injury, the ASIA motor score and Spinal Cord Independence Measure (SCIM) were assessed as dependent variables (linear regression analysis) to disclose the difference between each segment. Separate analyses using linear regression for tetraplegic patients (n = 39) and paraplegic patients with thoracic lesions (n = 54) were performed to calculate the difference between each spinal segment. In tetraplegic patients, both the ASIA motor score and the SCIM revealed relevant differences per spinal segment (9 and 4 points, respectively) while in paraplegic patients there was no difference for the SCIM and the ASIA motor score between T2 and T8. We suggest that in complete tetraplegic patients, changes of even one spinal segment will either improve or degrade both motor function and independence. Segmental changes at the thoracic level are not assessable by the ASIA motor score and SCIM tests. Therefore, the assessment of efficacy and safety in thoracic patients by these two tests has limited value when applied to cervical SCI. These findings may be considered in clinical trials for the evaluation of beneficial effects and risk management when treating patients with spinal cord injury.

Activities of Daily Living↗

Association of dietary protein intake and coffee consumption with serum homocysteine concentrations in an older population.

BACKGROUND: Elevated blood concentrations of total homocysteine (tHcy) have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. Previous studies identified suboptimal nutritional status and dietary intake of folate, vitamin B-6, and vitamin B-12 as determinants of elevated tHcy. OBJECTIVE: We identified other nutritional factors associated with tHcy in 260 retired schoolteachers in the Baltimore metropolitan area. DESIGN: We performed observational analyses of baseline and 2-4-mo follow-up data collected in a study designed to test the feasibility of conducting a large-scale clinical trial of vitamin supplements by mail. The study population consisted of 151 women and 109 men with a median age of 64 y. At baseline, each participant completed a food-frequency questionnaire. At follow-up, fasting serum tHcy was measured. RESULTS: In multivariable linear regression and generalized linear models, there was an independent, inverse dose-response relation between dietary protein and In tHcy (P = 0.002) and a positive, significant dose-response relation between coffee consumption and In tHcy (P for trend = 0.01). Other significant predictors of In tHcy were creatinine (positive; P = 0.0001) and prestudy use of supplemental B vitamins (inverse; P = 0.03). In stratified analyses restricted to persons receiving standard multivitamin therapy, the association of 1n tHcy with dietary protein and coffee persisted. CONCLUSIONS: These results support the hypothesis that increased protein intake and decreased coffee consumption may reduce tHcy and potentially prevent atherosclerotic cardiovascular disease and other disease outcomes.

Aged↗

Multiple roles and well-being among midlife women: testing role strain and role enhancement theories.

OBJECTIVE: Research on women's multiple roles frequently adopts one of two perspectives: role strain, which argues that assuming multiple roles is detrimental to mental well-being, or role enhancement, which argues that engaging in multiple roles enhances mental well-being. We argue that the relationship between role occupancy and well-being is manifested through multiple dimensions of role experiences. We investigate the association between depressive symptomatology and various dimensions of the roles of wife, mother, paid worker, and informal caregiver to aging parents. METHODS: Data are from the 1992 wave of the Health and Retirement Study. Depressive symptomatology, measured by a subset of the CES-D scale, is the dependent variable. To assess the robustness of findings relative to different functional forms of the dependent variable, we estimate multiple regression, log-linear regression, and multinomial logit models. Independent variables include demographic characteristics, measures of role occupancy, role demands, and role satisfaction. RESULTS: Although the number of roles women assume affects their reports of depressive symptoms, once the demand and satisfaction associated with these roles is controlled, number has no effect; that is, the effect of the number of roles is indirect. DISCUSSION: Our results highlight the importance of women's perceptions of the quality of their roles in relation to their overall well-being. Future investigations of women's multiple roles should examine how roles may provide rewards, impose constraints, or generate conflict, as well as the extent to which the willingness to assume multiple roles and the reported levels of role satisfaction and mental well-being may be jointly endogenous.

Caregivers↗

Mathematical modeling of rewarming after cold therapy.

Statistical methods are presented for fitting mathematical models to skin temperature data. Three types of regression curves, namely, linear regression (Y = A + BX), second-degree regression (Y = A + BX + CX2), and asymptotic regression (Y = alpha + betapx), are discussed as possible models for the rewarming process following cold therapy. The data for fitting the curves consists of back surface temperature (degrees C) corresponding to various times after cold pack treatment (19 degrees C, administered for 20 minutes) was terminated.

Cryotherapy↗