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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
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↗
PubMed1995

Frequency of phobic disorder in a community sample of young adolescents.

OBJECTIVE: To investigate the frequency and phenomenology of clinical, subsyndromal, and subthreshold phobias in young adolescents. METHODS: A two-stage epidemiological study originally designed to investigate adolescent depression was conducted between 1986 and 1988 in the southeastern United States. In the first stage, 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 and the Children's Global Assessment Scale were administered to 487 mother-child pairs. RESULTS: Prevalence rates of clinical, subsyndromal, and subthreshold phobia were 2.3%, 14.5%, and 22.2%, respectively. One-year incidence rates were 0.4%, 8.0%, and 16.9%, with 43.0% of phobic subjects categorized at the same or a more severe level after a year. Females, blacks, subjects not living with both biological parents, and older adolescents were more likely to meet the diagnostic criteria for clinical phobia. The majority (77%) of subjects with clinical phobia experienced multiple phobias. Subsyndromal (52%) and subthreshold (74%) phobics were more likely to experience simple phobias only. CONCLUSIONS: Phobic symptoms are relatively common at a moderate level and in the majority of adolescents are somewhat transitory in nature. Characteristic symptomatology and comorbidity may facilitate earlier identification of subjects at risk of persistent symptomatology and in need of treatment.

Adolescent↗
PubMed1994

Confidence intervals for weighted proportions.

We investigate methods for the construction of confidence intervals for a proportion in a stratified two-stage sampling design with few events occurring in a small number of large, unequal size strata. The critical aspect is the incorporation of the weighting scheme into the construction of a single overall confidence interval. With small numbers of events, the binomial based methods may be inadequate since the normal approximation is not valid. Computer simulations compare coverage probability and bias for five methods of obtaining confidence intervals for proportions by combining: (1) binomial variances; (2) confidence intervals based on the F-distribution approximation to the cumulative binomial; (3) the binomial variance method with exact confidence limits when a zero prevalence occurs in any stratum; (4) confidence intervals based on the F-distribution using a rescaling factor; and (5) the binomial variance method with exact confidence limits using a rescaling factor. The method that performs best in terms of coverage probability is the combination of stratum specific confidence intervals based on the F-distribution using a rescaling factor. The methods involving the binomial variance tend to be negatively biased and the methods based on the F-distribution tend to be positively biased. Application of these methods with data from a study of adolescent depression that employs a stratified two-stage sampling design is consistent with these results.

Adolescent↗
PubMed1993

Safety hazards in households with young children.

Interviewed 230 mothers of young children concerning in-home observations of safety hazards related to burns, poisoning, and falls, and self-reported measures of maternal supervision, locus of control, social support, and safety attitudes. These were supplemented by measures of mothers' risk perceptions, stress and coping, their child's previous injury experience, and indicators of the family's socioeconomic status (SES) collected by telephone survey. SES was an important predictor of observed home hazards. Child-related variables, risk perceptions, and domain-specific attitudes had little influence on home hazards. Maternal supervisory style, rated on dimensions of protectiveness, was an important correlate of all types of household hazards. Results suggest that residential injury prevention strategies for young children should stress active as well as passive countermeasures.

Accidents, Home↗
PubMed1993

Mother-adolescent agreement on the symptoms and diagnoses of adolescent depression and conduct disorders.

OBJECTIVE: To determine rates and correlates of mother-adolescent agreement on the symptoms and diagnoses of depression and conduct disorders. METHOD: The Schedule for Affective Disorders and Schizophrenia in School Age Children was administered to a community sample of 460 adolescents and their mothers. Race, gender, family adaptability and cohesion, and living arrangement were evaluated as predictors of agreement. RESULTS: Mother-adolescent agreement was low (kappa < 0.40) for all diagnoses and symptoms with these exceptions: feeling tired (kappa = 0.40), inattention (kappa = 0.50), vandalism (kappa = 0.50), and chronic violation of rules (kappa = 0.72). Cohesion and adaptability were associated with mother-adolescent agreement on the symptoms and diagnosis of depression. This association was not demonstrated as consistently for agreement on the symptoms and diagnosis of conduct disorders. CONCLUSION: Study findings underscore the necessity of collecting data from both a parent and the adolescent when assessing an adolescent's psychological status.

Adolescent↗
PubMed1993

Radiation hepatology of the rat: time-dependent recovery.

In situ recovery kinetics of gamma-irradiated rat livers was investigated. To measure short-term repair, surgically exposed livers were irradiated with a 12.5-Gy priming dose. At various times (0-24 h) the liver was re-exposed surgically to 10 Gy. To measure long-term recovery, rats were exposed to a 10-Gy priming dose to the upper abdomen to irradiate the whole liver. The liver was then re-exposed surgically and given graded test doses 0 to 56 days after the first exposure. Repair as a function of interfraction interval (1-12 h) between eight fractions of 3 Gy to the upper abdomen followed 2 weeks later by an 10-Gy top-up dose to the exposed liver was also investigated. Approximately 3 months after the last exposure plasma aspartate aminotransferase, retention of intravenously injected rose bengal, liver weight, and hydroxyproline content were measured to determine hepatic necrosis, function, mass, and fibrosis, respectively. A 15-Gy single-exposure threshold dose was needed to produce detectable hepatic injury. Exceeding this threshold dose resulted in a dose-dependent increase in liver injury as measured by all four end points. Split-dose irradiation with a 10-Gy priming dose and an interfraction interval of 1 day increased the isoeffect dose by 3.9 to 5.8 Gy. Increasing the interfraction interval from 1 to 56 days did not further increase the isoeffect dose. Exposing the liver to eight fractions of 3 Gy with an interfraction interval of 3 h or longer resulted in a dose recovery of approximately 80% (i.e., 19 Gy). A substantial portion of this recovery was evident with interfraction intervals of 1 h. A fluctuating repair pattern with increasing time (0 to 24 h) between 12.5 and 10.0 Gy liver irradiation was observed. This repair was characterized by a 1-h delay after irradiation, followed by near complete repair during the next 3 h, followed by sensitization during the next 2 h and a second wave of repair between 8 and 24 h. Repair was not completed until 21 h after irradiation. It is concluded that the liver's capacity to repair injury within 24 h is similar to that of other late-responding tissues. However, there is no additional repair after 24 h, indicating an absence of slow repair.

Animals↗
PubMed1993

Amelioration of radiation nephropathy in rats by dexamethasone treatment after irradiation.

The effect of 20 Gy intraoperative bilateral local kidney irradiation was compared in rats treated after irradiation with dexamethasone and untreated rats. Ninety days after irradiation, body weights, WBC, RBC, hematocrit, and renal function (plasma urea nitrogen concentration and retention of ethylenediaminetetraacetic acid) were measured. The animals were then sacrificed and the kidneys were analyzed for water and hydroxyproline content and examined histologically. Local kidney irradiation reduced animal growth, prevented renal growth, decreased renal mass and renal function, and increased the water and hydroxyproline content of the kidneys. Histopathological examination revealed glomerular damage (atrophy, decreased RBC and endothelial cells, increased mesangial matrix), tubular damage (epithelial denudation, congestion with hyalin casts), and increased concentration of interstitial cells. Dexamethasone treatment significantly ameliorated the effects of kidney irradiation on body weights, renal mass, renal function, and the development of anemia. Dexamethasone had no effect on radiation-induced edema or fibrosis as measured by the water and hydroxyproline content of the kidneys. Dexamethasone-treated irradiated kidneys had significantly less damage to the glomeruli and tubules. The results suggest that dexamethasone is cytoprotective and prevents the destruction of the nephron.

Animals↗
PubMed1993

Effect of adrenalectomy on the latency of radiation myelopathy in rats.

The effect of adrenalectomy on the development of radiation myelopathy was studied. A 1-cm section of cervical cord of adrenalectomized and intact animals was exposed to graded doses (18 to 30 Gy) of gamma rays. The radiation tolerance, the latent period from exposure to paralysis, plasma corticosterone levels at the time of paralysis, and histopathology of the cord were evaluated. Adrenalectomy essentially eliminated endogenous production of corticosterone and significantly shortened the mean latent period between irradiation (24 to 30 Gy) and paralysis by more than 10 weeks. This reduced latent period was not reversed by the administration of the exogenous glucocorticoid, dexamethasone, and corticosterone, although prolonged administration of dexamethasone resulted in the development of Cushingoid features, indicating hypercorticoidism. Histopathological examinations indicated that adrenalectomized paretic animals had multiple hemorrhages in both the gray and the white matter, but less white matter necrosis than normally observed in intact paretic animals irradiated similarly. Possible mechanisms for the shortened latent period in adrenalectomized animals are discussed.

Adrenalectomy↗
PubMed1992

Major depressive disorder and dysthymia in young adolescents.

A two-stage epidemiologic study conducted between 1986 and 1988 in the southeastern United States investigated the frequency of major depressive disorder and dysthymia in 12-14 year olds. In stage one, the Center for Epidemiologic Studies Depression Scale, a life event schedule, and a family cohesion scale were administered to a community sample of 3,283 adolescents. In stage two, 488 mother-child pairs were interviewed utilizing the Schedule for Schizophrenia and Affective Disorders in School Age Children. Although mean Center for Epidemiologic Studies Depression Scale scores were significantly higher in females (25.60) than in males (19.50), prevalence estimates based on a summary of mother and child symptom reports for Diagnostic and Statistical Manual of Mental Disorders, Third Edition, major depressive disorder were similar: 9.04% in males and 8.90% in females. The prevalences of dysthymia were 7.98% in males and 5.00% in females. Previous investigations have reported lower rates and a female preponderance of major depression. Disagreement between mothers and children regarding the presence of symptoms may explain this contradiction. Significant odds ratios were found between major depression and not living with both natural parents (odds ratio (OR) = 3.89), undesirable life events (OR = 1.09), and perceived family cohesion (OR = 0.96). Not living with both natural parents (OR = 14.67) and socioeconomic status (OR = 0.44) were significant correlates of dysthymia.

Adolescent↗
PubMed1992

Effects of dexamethasone on the development of radiation nephropathy in the rat.

Low-dose, chronic administration of the synthetic glucocorticoid, dexamethasone, to male CD-I rats in the drinking water or by osmotic minipumps implanted subcutaneously after supralethal irradiation of the kidneys (20 Gy) was studied. The effectiveness of treatment with dexamethasone in the drinking water at concentrations of 23 micrograms/l to 188 micrograms/l and treatment times varying from 33 to 166 days was evaluated. At monthly intervals kidney function was assayed by measuring the clearance of 51Cr-ethylenediaminetetraacetic acid. All dexamethasone treatment regimens increased survival times significantly and delayed the development of kidney dysfunction. The most effective combination of concentration of dexamethasone in drinking water and treatment interval after irradiation with respect to survival was 94 micrograms/l and 88 days. However, a slightly longer survival and a better functional result was obtained if an equivalent amount of dexamethasone was administered by minipumps. Shielding the adrenal glands during kidney irradiation did not prolong survival. This shows that the beneficial effect of dexamethasone is not due to compensation for reduced adrenal glucocorticoid production resulting from concomitant exposures of these glands during kidney irradiation.

Adrenal Glands↗
PubMed1992

Effects of dexamethasone on late radiation injury following partial-body and local organ exposures.

Dexamethasone was evaluated as a treatment for radiation-induced lung, kidney, liver, and spinal cord injuries in rats. One experimental group was partial-body-irradiated (22.5 Gy) with the head, femur, and exteriorized intestine shielded to prevent acute mortality. Other animals received local irradiation to the kidney (20 Gy), liver (25 Gy), or a 1-cm segment of cervical spinal cord (18 to 40 Gy). Following irradiation half of the animals in each radiation group were given drinking water containing 188 micrograms/liter of dexamethasone. Tests were done to assess kidney function (hematocrit, plasma urea nitrogen, ethylenediaminetetraacetic acid clearance), liver function (rose bengal clearance, plasma glutamic oxaloacetic acid transaminase), or spinal cord injury (paralysis). The effectiveness of dexamethasone in preventing radiation injury was tissue specific. Dexamethasone eliminated lethal pleural fluid accumulation after partial-body irradiation and delayed development of kidney dysfunction after local kidney irradiation. As a result, dexamethasone increased the median survival time from 63 to 150 days after partial-body irradiation and from 126 to 175 days after local kidney irradiation. After whole-liver irradiation, development of hepatic functional injury was retarded by dexamethasone treatment but without significantly changing survival time. Dexamethasone had no effect on spinal cord tolerance but significantly shortened the latent period between radiation and paralysis.

Animals↗
PubMed1992

Radiation hepatology of the rat: microvascular fibrosis and enhancement of liver dysfunction by diet and drugs.

Prior to whole-liver irradiation (0, 15, 25 Gy) rats were not treated, placed on a protein-deficient diet for 2 weeks, administered cyclophosphamide, and/or depleted of intracellular glutathione by injection with buthionine sulfoximide and diethyl maleate. At various times (0 to 84 days) after 0- and 25-Gy liver irradiation, liver function, liver mass, and hydroxyproline content were measured in nontreated animals. Liver function was measured in all other preirradiation regimens 2 to 3 months postirradiation. Histology and/or India ink perfusion of the liver were done on ascitic and jaundiced animals from all treatment groups. Approximately 20% of the 25-Gy whole-liver-irradiated animals in each preirradiation treatment group developed clinical signs of acute hepatitis (ascites, jaundice, and elevated liver enzymes in the plasma) 70 to 100 days after irradiation. Twenty-five-gray whole-liver irradiation also resulted in significant liver fibrosis that preceded the onset of liver dysfunction. Fibrotic changes were most dramatic in and around hepatic veins, sometimes resulting in complete or partial occlusion that disrupted intrahepatic blood flow and diminished liver function. In addition, a substantial accumulation of fluid in the liver of 25-Gy-irradiated livers occurred, resulting in a lower dry/wet liver weight ratio. Functional hepatic injury was enhanced by preirradiation treatment with a protein-deficient diet, cyclophosphamide, and/or depletion of intracellular glutathione. This enhancement of functional injury was pronounced after 15-Gy whole-liver irradiation when injury from radiation alone was minimal.

Animals↗
PubMed1991

Suicidal behaviors in young adolescents.

A two-stage epidemiologic study investigated the frequency of suicidal behavior in children 12-14 years of age. In the first stage, the Center for Epidemiologic Studies Depression Scale, a three-item suicide scale, a life-event schedule, and a family environment scale were administered during 1986 to a southeastern US community sample of 1,542 seventh and eighth grade students. In the second stage, 226 mother-child pairs were interviewed utilizing the Schedule for Schizophrenia and Affective Disorders in School Age Children (K-SADS). Subjects interviewed included students with high depression scores and a random sample of the remaining students. Prevalence estimates for moderate to severe suicidal ideation (K-SADS score greater than or equal to 4) were 4.0% (95% confidence interval (CI) 0.6-16.4%) in males and 8.7% (95% CI 2.4-23.3%) in females. The prevalences of suicide attempts were 1.9% (95% CI 0.0-13.2%) in males and 1.5% (95% CI 0.6-12.7%) in females. Significant relations were found between major depression and both suicide ideation (odds ratio = 6.19, 95% CI 1.53-24.94) and suicide attempts (odds ratio = 9.80, 95% CI 1.89-50.86). The undesirable life-events score was also a significant predictor of suicide ideation and suicide attempts.

Adolescent↗