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S Back

Publications and source records attributed to S Back.

15 recordsLinked to original sources
PubMed2001

Experience and covariates of depressive symptoms among a cohort of HIV infected women.

OBJECTIVES: The objectives of this study are to assess (a) the level of depressive symptoms among a cohort of HIV infected women and comparable controls and (b) the relationship with covariates including socioeconomic status, substance use, social relations, disease status. METHODS: Participants were enrolled in the Women's Interagency HIV Study (WIHS). Depressive symptoms were measured using the Center for Epidemiological Studies Depression Scale (CESD). Data from 1993 HIV seropositive and 551 seronegative women are presented. RESULTS: Of HIV positive women 57.7% of HIV positive women scored 16 or higher on the CESD (ns) as compared to 55.0% of HIV negative women; at a cutoff of 23, the percents were 40.4% and 35.9% respectively (p = .06). The mean score was high 19.8 but not significantly different between groups. Scores were higher among women who had less education, lower income, were of Hispanic ethnicity, used alcohol or drugs, experienced domestic abuse, had more than one partner, or had less supportive relationships. Among infected women, higher CESD scores were not significantly associated with CD4 cell count but were elevated for self-reported Class C AIDS defining clinical conditions. CONCLUSIONS: The scores on the CESD were elevated for both HIV positive and HIV negative women and the differences between the groups were small. Lower socioeconomic status and social support and higher substance use and domestic abuse were associated with depressive symptoms similarly for both groups.

Analysis of Variance↗
PubMed2001

Sample size and statistical power of randomised, controlled trials in orthopaedics.

We reviewed all 717 manuscripts published in the 1997 issues of the British and American volumes of the Journal of Bone and Joint Surgery and in Clinical Orthopaedics and Related Research, from which 33 randomised, controlled trials were identified. The results and sample sizes were used to calculate the statistical power of the study to distinguish small (0.2 of standard deviation), medium (0.5 of standard deviation), and large (0.8 of standard deviation) effect sizes. Of the 33 manuscripts analysed, only three studies (9%) described calculations of sample size. To perform post-hoc power assessments and estimations of deficiencies of sample size, the standard effect sizes of Cohen (small, medium and large) were calculated. Of the 25 studies which reported negative results, none had adequate power (beta < 0.2) to detect a small effect size and 12 (48%) lacked the power necessary to detect a large effect size. Of the 25 studies which did not have an adequate size of sample to detect small differences, the average used was only 10% of the required number Our findings suggest that randomised, controlled trials in clinical orthopaedic research utilise sample sizes which are too small to ensure statistical significance for what may be clinically important results.

Humans↗
PubMed2000

Potential nitrite scavengers as inhibitors of the formation of N-nitrosamines in solution and tobacco matrix systems.

The ability of 20 compounds, all but one tobacco constituents, to inhibit the formation of tobacco-specific N-nitrosamines (TSNA) was investigated in buffer and detergent solution and in tobacco midrib and lamina systems. In solution at pH 5.5, ascorbic acid and the phenolic acids caffeic and ferulic acid were the most potent inhibitors of the reaction between nornicotine and nitrite, with nearly complete inhibition at molar ratios test compound/nitrite > 1:1. Also, cysteine > dihydrocaffeic acid > protocatechuic acid approximately catechin acted as strong inhibitors with >90% inhibition at a ratio of 3:1. Lower inhibitions were observed with chlorogenic acid > p-coumaric acid > sclareol > serine. Rutin showed an inhibition of 34% at a ratio of 0.1:1. Sclareol, alanine, proline, and serine did not significantly affect the N-nitrosonornicotine (NNN) formation. alpha-Tocopherol and glutathione enhanced NNN formation at pH 5.5 but were inhibitors at pH 3. Cinnamic acid, vanillic acid, eugenol, and esculin enhanced NNN formation. Increased NNN formation was also observed for dihydrocaffeic acid, chlorogenic acid, protocatechuic acid, and catechin at a less-than-equimolar ratio of test compound to nitrite. The tobacco matrix experiments were performed with air-cured, ground tobacco midrib and lamina. Caffeic acid, ferulic acid, dihydrocaffeic acid and catechin were potent inhibitors of the formation of TSNA in the midrib as well as in the lamina. Also protocatechuic acid, glutathione, ascorbic acid, p-coumaric acid, chlorogenic acid and cysteine were inhibitors, while alpha-tocopherol and rutin inhibited the reaction in the midrib but not in the lamina. Cinnamic acid, vanillic acid, eugenol, alanine, proline and serine showed small effects only. The molar ratio of secondary alkaloid(s)/nitrite in the test systems were 0.1:1 (solution), approximately 0.25:1 (midrib), and approximately 1:1 (lamina) and is most likely the major contributor to the observed order of inhibition potency (solution > midrib > lamina) of the test compounds. The vicinal phenolic hydroxyl groups of polyphenols and the simultaneous presence of a phenol group and an olefinic bond in hydroxycinnamic acids were the most characteristic structural elements of the potent inhibitors.

Free Radical Scavengers↗
PubMed2000

Cocaine dependence with and without post-traumatic stress disorder: a comparison of substance use, trauma history and psychiatric comorbidity.

This study examined the relationship between substance use, trauma history, post-traumatic stress disorder (PTSD), and psychiatric comorbidity in a treatment seeking sample of cocaine dependent individuals (N = 91). Structured clinical interviews revealed that 42.9% of the sample met DSM-III-R criteria for lifetime PTSD. Comparisons between individuals with and without lifetime PTSD revealed that individuals with PTSD had significantly higher rates of exposure to traumatic events, earlier age of first assault, more severe symptomatology, and higher rates of Axis I and Axis II diagnoses. The results illustrate a high incidence of PTSD among cocaine dependent individuals. Routine assessment of trauma history and PTSD may assist in the identification of a subgroup of cocaine users in need of special prevention and treatment efforts.

Adult↗
PubMed1998

Child sexual abuse: victim age, victim gender, and observer gender as factors contributing to attributions of responsibility.

OBJECTIVE: The purpose of this study was to investigate the effects of victim gender, and observer gender on the tendency to attribute responsibility for extrafamilial child sexual abuse to the victim and the nonoffending parents. METHOD: A 2 (Victim Age) x 2 (Victim Gender) x 2 (Observer Gender) between-subjects design was employed. Undergraduate students (N = 145) read a vignette describing a sexually abusive interaction between an adult male neighbor and a child. In this vignette, the child's gender and age (6 years old, 13 years old) varied. After reading the vignette, participants used a 5-point scale to indicate the degree to which they believed the victim and the parents (a) were responsible for, (b) were to blame for, (c) caused, and (d) could have prevented the abuse. RESULTS: Greater responsibility was assigned to older than younger victims. Both parents were ascribed similar levels of responsibility, and were ascribed greater responsibility when the child victim was younger than older. Male observers attributed greater responsibility and causality to the victim and the parents than did female observers. CONCLUSIONS: The results indicate that responsibility attributions directed toward the victim and the nonoffending parents may be a function of the victim's age. In addition, the findings support previous research suggesting that male observers may tend to hold victims more responsible for their abuse than female observers. Implications for treatment and research are discussed.

Adolescent↗
PubMed1994

Antibodies to pneumococcal capsular polysaccharides in children with human immunodeficiency virus infection given polyvalent pneumococcal vaccine.

Antibody to 7 common pneumococcal capsular polysaccharides was measured in 11 children with human immunodeficiency virus (HIV) infection who had been previously vaccinated with 23-valent polysaccharide pneumococcal vaccine, 11 unvaccinated children with HIV infection, and 11 healthy subjects. No differences in capsule-specific IgG levels against serotypes 4, 6B, 8, 12F, 14, 19A, and 19F were observed among the vaccinees with HIV infection compared with unvaccinated children with HIV infection and age-matched control children.

Antibodies, Bacterial↗
PubMedDate not supplied

[Familial seroepidemiology of toxocariasis].

With the objective of defining the intrafamiliar distribution pattern of the infection and illness caused by Toxocara sp., 78 infected families (356 people) were studied for 30 months. At the same time 28 families free of infection were studied, as a control group (97 people). The socioeconomic level was analyzed according to a modified Graffar index. Contac with canine and feline pets, and antecedents of geophagia and onichophagia were found to be risk factors which would facilitate the infection. The average of persons infected, diagnosed by ELISA Toxocara test, was 2.8 per family. The importance of familiar distribution of the infection and its primary prevention is strongly stressed.

Adolescent↗