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Biomedical subjects

K L Jackson

Publications and source records attributed to K L Jackson.

At least 19 recordsLinked to original sources
PubMed2001

High-risk HPVs and risk of cervical neoplasia: a nested case-control study.

The purpose of this nested case-control study was to estimate the risk of SIL development among a cohort of women providing cervical samples as part of their family planning visit at baseline in 1991-1992. All women had normal cervical cytology (N = 2905) at baseline and provided a cervical sample for subsequent HPV typing. Among this cohort, 426 women developed SIL (22 HSIL and 404 LSIL), 619 developed atypia, and 1860 remained cytologically normal. Two controls per case were sampled from those who remained normal. PCR-based methods with L1 consensus primers were used to assess high-risk HPV positivity. Having an oncogenic HPV type at baseline was associated with an almost fourfold increased risk of HSIL development (relative risk (RR) = 3.8; 95% CI, 1.5--9.0) and a 70% increased risk of LSIL development (RR = 1.7; 95% CI, 1.2--2.3%). The association between HPV positivity and SIL development was strongest in the first year of follow-up (RR = 9.2 for HSIL and 2.5 for LSIL development). The decline in HPV-associated SIL risk may be a function of having only one measure of HPV positivity (at baseline).

Adult↗
PubMed2001

A longitudinal study of adolescent mental health service use.

This study examines longitudinal mental health service use patterns of a school-based sample of adolescents. Based on the Center for Epidemiologic Studies Depression Scale scores, a stratified sample of middle-school students was interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Aged Children: cycle one (n = 579; mean age 12.83) and cycle two (n = 490; mean age 18.65). Service use also was assessed by mailed questionnaire: cycle three (n = 330; mean age 20.60). Service use decreased over time. Whites and males received significantly more treatment in the first cycle. In the second cycle, service use by race and gender was equal; in the third cycle, females received more treatment. Those with a psychiatric diagnosis (first cycle, 54%; second cycle, 33%) received treatment in the prior year. Under-treatment of youth with psychiatric diagnoses is a significant problem, with differences in service use by race and gender over time.

Adolescent↗
PubMed2001

Prevalence of attention-deficit/hyperactivity disorder in a community sample of older adolescents.

OBJECTIVE: To study the prevalence and correlates of attention-deficit/hyperactivity disorder (ADHD) in a community sample of older adolescents. METHOD: From 1986 to 1988, 3,419 seventh, eighth, and ninth graders were screened with the Center for Epidemiologic Studies-Depression Scale. The top decile scorers and a random sample of the remainder were interviewed with the Schedule for Affective Disorders and Schizophrenia for School-Age Children. These data are from the second wave of interviews (N = 490, mean age = 18.65). RESULTS: The weighted prevalence of DSM-III-R ADHD was 1.51% (males: 2.62%, females: 0.54%). Significant associations (p < .05) were found for gender (male), comorbid affective disorders, baseline undesirable life events, and fewer than two biological parents at baseline. Family cohesion (p = .058) is inversely associated with ADHD. For subjects not meeting the age-at-onset criterion, 1.94% met the eight symptom criteria, and females (3.2%) were more prevalent than males (0.3%). CONCLUSIONS: ADHD remains a problem in this sample of older adolescents and is often comorbid with affective disorders. A significant number report eight ADHD symptoms but do not meet the age-at-onset criterion. This group deserves research attention.

Adolescent↗
PubMed2000

C-terminal epitope tagging facilitates comparative ligand mapping from MHC class I positive cells.

Purification of specific class I molecules prior to peptide ligand characterization is complicated by the presence of multiple class I proteins in most cell lines. Immortalized B, T, and tumor cell lines typically express endogenous HLA-A, -B, and -C; and most individuals from which the cell lines are derived are heterozygous at these loci. Antibodies specific for a particular HLA molecule may be used for purification, but allele-specific antibodies can be biased by ligands occupying the peptide-binding groove. Through the use of C-terminal tagging, we have developed a method of soluble HLA production such that downstream purification does not skew the peptide analysis of the examined molecule. Comparison of peptides eluted from HLA class I molecules with and without C-terminal tags demonstrates that addition of a tag does not abrogate the peptide binding specificity of the original molecule. Both pooled Edman sequencing and mass spectrometric sequencing identified no substantial differences in peptides bound by untailed, 6-HIS-tailed, and FLAG-tailed class I molecules, demonstrating that the peptide specificity of a given molecule is not distorted by either tag. This production methodology bypasses problems with isolation of specific molecules and permits ligand mapping and epitope discovery in a variety of pathogen-infected and tumor cell lines.

Amino Acid Motifs↗
PubMed1999

Association between exercise and HIV disease progression in a cohort of homosexual men.

PURPOSE: To study the relationship between exercise and human immunodeficiency virus (HIV) disease progression. METHODS: 415 individuals (156 HIV positive, 259 HIV negative), from a cohort study of 851 homosexual men from New York City, 1985-1991. By 1991, 68 of the 156 persons developed Acquired Immune Deficiency Syndrome (AIDS) and 49 died with AIDS. Exercise was defined as self-report of exercising 3-4 times/week or daily at entry; less was considered nonexercise. CD4 lymphocyte decline was constructed for each subject by modeling log CD4 count against time in days. The association between exercise and progression to AIDS and death with AIDS, adjusting for baseline CD4 count, was determined using Cox model. Linear regression was used to model CD4 decline with exercise for HIV positive and HIV negative groups separately, adjusting for initial CD4 count. RESULTS: Having exercised was associated with slower progression to AIDS at 1 year (HR = 0.68, 90% confidence interval (CI): 0.4-1.17); hazard ratios (HR) at 2, 3, and 4 years were 0.96, 1.18, and 1.36, respectively. Having exercised was also associated with slower progression to death with AIDS at 1 year (HR = 0.37, 90% CI: 0.14-0.94) with hazard ratios at 2, 3, and 4 years of 0.68, 0.98, and 1.27, respectively, suggesting a protective effect close to the time exercise was assessed, but an increased risk after 2 years. Exercising 3-4 times/week had a more protective effect than daily exercise. Exercisers in the HIV positive group showed an increase in CD4 count during a year by a factor of 1.07. CONCLUSION: Moderate physical activity may slow HIV disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Association between employment and substance abuse behaviors among public high school adolescents.

PURPOSE: To examine the relationship between adolescents' after-school and weekend employment and substance abuse behaviors in a cross-sectional sample of public high school students in South Carolina. METHODS: The Centers for Disease Control and Prevention Youth Risk Behavior Survey (YRBS) was used to secure usable data from 4800 subjects. Logistic regression adjusting for age and using SUDAAN were performed. Odds ratios and 95% confidence intervals were calculated from the regression analyses. RESULTS: Thirty percent of white males, 29% of white females, and 20% of black males and females worked at a job for pay during the academic year. For white males employment, ranging from 11 to 15 h and 26 to > or =31 h was associated with cigarette smoking, working from 11 to > or =31 h was associated with alcohol use, working > or =31 h was associated with binge drinking, working from 26 to > or =31 h was associated with marijuana use, and working from 26 to 30 h was associated with cocaine use. For white females, working from 16 to 20 h was associated with alcohol use, working from 21 to 30 h was associated with binge drinking, and working from 26 to 30 h was associated with marijuana and cocaine use. CONCLUSION: Youth who work above 15 h/week at a job for pay during high school appear to have an increased risk for substance abuse and its consequences.

Adolescent↗
PubMed1998

Exaggerated blood pressure response to dynamic exercise and risk of future hypertension.

This study examined the association between an exaggerated blood pressure response to treadmill exercise and the risk of developing hypertension. Subjects were healthy normotensive men (n = 5386) who had a baseline graded maximal exercise test between 1971 and 1982, and completed a mailed follow-up questionnaire. At follow-up in 1986, cases (n = 151) reported physician diagnosed hypertension and controls (n = 201) reported normotension. Those who had developed hypertension at follow-up were more likely to have had an exaggerated blood pressure response to exercise (OR = 2.4, 1.4-4.3). In multiple logistic regression analysis an exaggerated response was significantly associated (OR = 3.0, 1.5-6.1) with future hypertension after controlling for sitting systolic and diastolic blood pressure, weight change from age 21 to follow-up, entry age, family history of hypertension, body mass index, treadmill time, alcohol consumption, and years of follow-up. These results suggest that an exaggerated blood pressure response to exercise is independently associated with increased risk of future hypertension, and therefore, may be an important factor in determining hypertension risk.

Adult↗
PubMed1998

Prevalence of PTSD in a community sample of older adolescents.

OBJECTIVE: To examine prevalence and correlates of trauma and posttraumatic stress disorder (PTSD) symptoms and diagnosis in older adolescents aged 16 through 22 years. METHOD: The second cycle of a longitudinal epidemiological study in the Southeast included a semistructured interview assessing PTSD symptomatology administered to 490 adolescents. RESULTS: Approximately 3% of female subjects and 1% of male subjects satisfied the DSM-IV criteria for PTSD. Females reported more traumatic events than males, and black subjects reported more events than white subjects. Being female (odds ratio = 12.32), experiencing rape or child sexual abuse (odds ratio = 49.37), and witnessing an accident or medical emergency (odds ratio = 85.02) were associated with increased risk of PTSD. CONCLUSIONS: While relatively few adolescents satisfy the criteria for PTSD, most subjects who experienced a traumatic event reported some PTSD symptoms. Specific types of traumatic events were associated with occurrence of PTSD.

Adolescent↗
PubMed1998

Incidence and predictors of suicidal behaviors in a longitudinal sample of young adolescents.

OBJECTIVE: This analysis examines 1-year transition probabilities and baseline predictors for suicidal behaviors in young adolescents. METHOD: Adolescents from a two-stage, community-based longitudinal study were classified into suicidal behavior categories (attempt, plan, ideation, and none) for baseline and follow-up years. Transition probabilities for movement among categories were calculated, and polytomous logistic regression analysis was used to examine predictors of suicidal behaviors. RESULTS: Among those with no suicidal behaviors at baseline, 1-year incidence rates were 1.3% for attempts and 1.7% each for plans and ideation. Increasing family cohesion was protective for suicide attempts (odds ratio [OR] = 0.9). Female subjects were more likely than males to report plans (OR = 8.9) and ideation (OR = 4.1). Increasing impulsivity (OR = 2.3), prior suicidal behavior (OR = 10.6), and undesirable life events (OR = 1.1) were significant predictors of plans. CONCLUSIONS: While there are a number of predictors of suicidal behaviors, the false-positive rate is high. Focusing on proximal risk factors, particularly stressors in adolescent development, may overlook the fundamental role of underlying mental disorder and familial factors--both biological and environmental. Suicide and suicidal behaviors are the result of a constellation of adverse factors requiring a range of interventions for prevention.

Adolescent↗
PubMed1998

Risk factors for congenital syphilis in infants of women with syphilis in South Carolina.

OBJECTIVES: This study examined risk factors for congenital syphilis in South Carolina. METHODS: Case infants with presumptive and confirmed congenital syphilis were compared with control infants born to women with reactive serologies during pregnancy, allowing investigation of risk factors for congenital rather than acquired transmission of syphilis. Data were collected from congenital syphilis report forms and birth certificates for 186 case infants and 487 controls born from 1991 to 1993. Odds ratios were calculated for maternal risk factors. RESULTS: Significant statistical trends were found for timing of first prenatal visit and number of visits. Other significant factors included rural residence (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.4, 2.9) and previous pregnancy loss (OR = 0.3, 95% CI = 0.2, 0.6). CONCLUSIONS: Prevention of congenital syphilis may be less effective among pregnant women with syphilis in South Carolina who have fewer prenatal care visits. Health care providers need further education on maternal/child syphilis management and techniques for motivating and educating patients.

Abortion, Spontaneous↗
PubMed1997

Black-white differences in body size perceptions and weight management practices among adolescent females.

OBJECTIVE: This study compares body size perceptions and weight management practices of black and white adolescent females. DESIGN: Subjects were selected through a statewide, three-stage sampling procedure designed to provide a sample statistically representative of high school students in South Carolina. SUBJECTS: Participants included black (n = 1824) and white (n = 2256) females, 14-18 years of age, enrolled in South Carolina public high schools. METHODS: Respondents were asked to assess their perceived body size as overweight, underweight, or about right. Self-reported weight management practices included dieting (reducing caloric intake), exercise, and other methods (including diet pills and vomiting). Chisquare analysis was used to assess the differences in body size perception and weight management behaviors. Polychotomous logistic regression was performed to examine association while controlling for socioeconomic status. RESULTS: Forty-one percent of the white adolescents and 29% of the black adolescents perceive themselves as overweight (p < 0.005). In the week prior to the survey, 28% of the white adolescents and 13% of the black adolescents reported dieting 34% of the while versus 23% of the black adolescents reported exercising to lose weight; and 45% of the white and 16% of the black students reported both dieting and exercising. Polychotomous logistic regression analysis showed that white adolescent girls were almost twice as likely to perceive themselves as overweight as black adolescent girls. The white students had 6.04 [95% confidence interval (CI), 1.77, 20.67] times the odds of using pills and vomiting and 3.76 (95% CI, 2.99, 4.72) times the odds of engaging in dieting and exercising as methods of weight management compared to the black students. CONCLUSIONS: These findings suggest that white adolescents are more likely to perceive themselves as overweight than black adolescents and are more likely to engage in unhealthy weight management practices than black adolescents.

Adolescent↗
PubMed1997

Effect of body mass index on activity limitation and mortality among older women: the National Health Interview Survey, 1986-1990.

We assessed the impact of body mass on the association between activity limitations due to chronic conditions and mortality among 24,612 noninstitutionalized white or African American women aged > or = 65 years who participated in a National Health Interview Survey between 1986 and 1990. We found that more African American women had activity limitations than white women (59% vs 46%, respectively). The difference by race was greatest (19% vs 10%) for the most severe limitation (unable to perform the major activity). For women aged 65-69, the major activity was working or keeping house; for those aged > or = 70, it was the ability to live independently. For white women in all three categories of body mass index (BMI) and for African American women with BMI 15%-85%, the risk of dying was significantly higher for those unable to perform the major activity than for those with no limitations, controlling for the effects of education, marital status, and perceived health. The findings confirm the established link between low BMI and mortality and between activity limitations and mortality. Additionally, the findings further suggest that activity limitations linked to chronic conditions increase the risk of death within each stratum of BMI after adjusting for potential confounders.

Activities of Daily Living↗
PubMed1997

Effects of a one-year physical activity intervention for older adults at congregate nutrition sites.

The effects of a physical activity intervention on strength, balance, motor coordination, and mobility were tested in a quasi-experiment at rural congregate nutrition sites. Twice-weekly sessions of low intensity movements were conducted for one year. Logistic regression results showed significant differences between intervention (n = 61) and comparison (n = 49) groups on several performance-based measures. Intervention subjects perceived significantly greater improvements in physical functioning over the previous year than did comparison subjects. A qualitative evaluation revealed perceived program benefits of pain reduction, increased flexibility, muscle strengthening, increased walking speed, and improved mental outlook.

Aged↗
PubMed1997

Incidence of major depressive disorder and dysthymia in young adolescents.

OBJECTIVE: An epidemiological study conducted between 1987 and 1989 in a single school district in the southeastern United States investigated the incidence, transition probabilities, and risk factors for major depressive disorder (MDD) and dysthymia in adolescents aged 11 to 16 years. METHOD: Diagnoses were based on the Schedule for Affective Disorders and Schizophrenia for School-Age Children, which was administered to 247 mother-adolescent pairs at 12-month intervals. RESULTS: One-year MDD and dysthymia incidences were 3.3% (n = 11) and 3.4% (n = 9), respectively. Transition probabilities demonstrated movement from disorder to no disorder over time. Family cohesion (odds ratio = 0.95) was the only significant predictor of incident MDD. No factors were significant for dysthymia. While baseline MDD was a significant risk factor for depression at follow-up, 80% of subjects with baseline MDD did not meet the criteria for diagnosis at follow-up. CONCLUSION: Findings suggest perceived family support or cohesion may be more important to adolescent mental health than family structure.

Adolescent↗
PubMed1997

Survival after AIDS diagnosis in South Carolina, 1982-1992.

The results of this study demonstrate that age, ethnicity, and AIDS-defining diagnosis are important predictors of survival time after AIDS diagnosis, and should be considered when planning treatment and services for people with AIDS. Future studies in states with large rural populations will be helpful in further understanding the natural history of the disease in areas outside the nation's major population centers. These could improve on the results of the present study by actively following up all cases to determine mortality status, collecting detailed clinical information on AIDS-defining diagnoses (with dates), collecting information on treatment of HIV infection and associated opportunistic infections, and evaluating service utilization. Monitoring survival trends over time remains an effective tool in evaluating the success of current efforts to provide treatment and services to people with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Incidence of obsessive-compulsive disorder in a community sample of young adolescents.

OBJECTIVE: To investigate the incidence, transition probabilities, and risk factors for obsessive-compulsive disorder (OCD) and subclinical OCD in adolescents. METHOD: A two-stage epidemiological study originally designed to investigate depression was conducted between 1987 and 1989 in the southeastern United States. For the screening, a self-report depressive symptom questionnaire was administered to a community sample of 3,283 adolescents. In the diagnostic stage, the Schedule for Affective Disorders and Schizophrenia for School-Age Children was administered to 488 mother-child pairs. Baseline screening and diagnostic data from the first year the subject completed an interview and follow-up diagnostic data from subsequent years were used. RESULTS: The 1-year incidence rates of OCD and subclinical OCD were found to be 0.7% and 8.4%, respectively. Transition probabilities demonstrated a pattern of moving from more severe to less severe categories. Of those with baseline OCD, 17% had the diagnosis of OCD at follow-up; 62% moved to the referent group. Of those with baseline subclinical OCD, 1.5% had OCD at follow-up and 75% moved to the referent group. Black race (odds ratio [OR] = 23.38), age (OR = 4.02), desirable life events (OR = 0.78), undesirable life events (OR = 1.21), and socioeconomic status (OR not estimable) were significant predictors of incident OCD. Age (OR = 2.30), desirable life events (OR = 0.92), and undesirable life events (OR = 1.13) were significantly associated with incident subclinical OCD. CONCLUSION: An initial diagnosis of subclinical OCD was not significantly predictive of a diagnosis of OCD at 1-year follow-up. The overall morbidity remained higher at follow-up in the baseline OCD group than in the baseline subclinical OCD group. The baseline subclinical OCD group was more dysfunctional at follow-up than was the baseline referent group. Further research concerning differences in symptomatology and impairment between OCD and subclinical OCD is warranted.

Adolescent↗
PubMed1996

Does lactose maldigestion really play a role in the irritable bowel?

Patients who met International Congress of Gastroenterology criteria for irritable bowel syndrome (IBS) and had breath hydrogen lactose testing were interviewed to determine whether detection of lactose maldigestion (LM) had an impact on their symptoms. Of 199 patients initially evaluated, 161 (81%) were contacted and asked to rate their symptoms. At baseline, 47 (29%) of the IBS group had LM. Before testing, 23 (49%) were aware that ingestion of lactose-containing food was associated with their gastrointestinal symptoms. Lactose-maldigesting IBS subjects (IBSLM, n = 47) and those who had IBS and no LM (n = 114) were similar in terms of age, sex, and ethnic background. Interviews performed 41 +/- 1.1 (SEM) months after baseline evaluation revealed no significant differences in abdominal pain, altered bowel habits, bloating/distension, mucus, and relief with defecation among those with IBS or LMIBS. Overall symptoms resolved, improved, did not change, or worsened in a manner not statistically different between IBS and IBSLM groups. IBSLM subjects (a) felt that identifying LM helped them gain awareness of food-symptom relationships (78.7%), (b) experienced some improvement in symptoms (83%), (c) were avoiding lactose foods (87.2%), or (d) used lactase enzyme supplements (38.3%). Identifying LM did not significantly affect rated variables.

Breath Tests↗