Search PubMed⌕ Search

Biomedical subjects

K Jackson

Publications and source records attributed to K Jackson.

At least 109 records · Page 6Linked to original sources
PubMed1991

Effect of agitation of BACTEC 13A blood cultures on recovery of Mycobacterium avium complex.

The effect of agitation of BACTEC 13A bottles (Becton Dickinson) on the recovery of Mycobacterium avium complex (MAC) from blood was compared with that of static incubation. A total of 265 blood specimens was inoculated in duplicate into BACTEC 13A bottles. One specimen was statically incubated at 35 degrees C, and the other was incubated with agitation on a Gyrotory shaker at 35 degrees C for the first 2 weeks and thereafter without shaking for up to 12 weeks. Of the 265 specimens, 77 (29.1%) were positive in either one or both of the paired bottles. The average detection times for the shaken and nonshaken bottles were 12.7 and 15.9 days, respectively. A total of 10.4% of the specimens in the shaken bottles became positive 1 week before those in the nonshaken bottles, and 16.9% of the shaken cultures were positive more than 2 weeks before their counterparts. A further 46.8% of the agitated specimens became positive while the corresponding nonagitated cultures remained negative. When both specimens became positive at the same time, 88% of the shaken cultures had higher growth indices than their nonshaken counterparts. A further 11 paired blood cultures were taken from patients known to be infected with MAC to assess the effect of agitation of bottles on the utility of making twice-weekly readings during the first 2 weeks of incubation. Ten of the 11 sets of specimens in the shaken bottles were positive 1 or more weeks before those in the corresponding nonshaken bottles. In the remaining set, both specimens became positive on the same day; however, the growth index of the agitated culture was higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗
PubMed1991

Predictors of risk perceptions of childhood injury among parents of preschoolers.

This article assesses the relationship between parents' perceived risk of childhood injuries and familial, sociocultural, and situational variables. Data were obtained through a random digit dial telephone survey of 1,200 households with a preschool child in a southeastern metropolitan area. Perceived risks of childhood injury measures were based on social science theory and childhood injury epidemiology. Multiple item measures included dimensions of seriousness and likelihood for both injuries and hazards. When risk perceptions were viewed as individual items, parents underestimated the risk of some hazards and injuries and overestimated the risks of others, and parents whose children have sustained a recent injury had higher risk perception overall. When risk perceptions were viewed as summed scales, sociodemographic variables and parental safety behaviors were not significant predictors. Sociocultural factors of having a child previously injured, the parent reporting stress, having a household with self-reported risk factors, and the perception of the child as active and hard to manage are related to summed scales of risk perceptions, with some interactions by race of the parent. Findings illustrate the role of situational and sociocultural characteristics of respondents in risk perception research.

Attitude to Health↗
PubMed1991

Using the health belief model to predict safer sex intentions among adolescents.

The purpose of this study was to use Health Belief Model (HBM) concepts to predict adolescents intentions to adopt safer sex behaviors. A stratified, random sampling technique was used to generate a sample of seventh-, ninth-, and eleventh-grade students representative of a southeastern state. A predictive model was constructed of the HBM variables. The model accounted for 43% of the variance in safer sex intentions among the seventh grade, 27% of the variance for the ninth grade and 17% of the variance for the eleventh grade. For the eleventh grade sample gender was the only significant predictor. The results of this study suggest that educational programs to promote safer sex intentions should focus on health related motivations among younger students. With older adolescents it may be more effective to expand education efforts to address factors directly relevant to their motivational schema and social environment. This study underscores the importance of using theory-based models in conducting health education research.

Adolescent↗
PubMed1991

Tuberculosis in Australia: an analysis of cases identified in reference laboratories in 1986-88.

The Special Interest Group in Mycobacteria within the Australian Society for Microbiology has carried out a collaborative study of cases of tuberculosis diagnosed in Australian reference laboratories in the years 1986, 1987 and 1988. Annual totals of 574, 584 and 613 respectively, suggest that the incidence of bacteriologically-positive tuberculosis is continuing at 3-4 cases per 100,000 population. The highest rates were detected in males over 50 and females over 65 years of age. Three-quarters of the total cases relate to pulmonary disease. Resistance to at least 1 anti-tuberculosis drug was detected in 78 (12.7%) of isolates tested in 1988. The negligible decline in incidence of tuberculosis in Australia, the high prevalence in S.E. Asian countries, and the fact that HIV-infection is an important risk factor, make it imperative that Australia's diagnostic and management programmes be maintained.

Adolescent↗
PubMed1990

Amiodarone-induced changes in lipid metabolism.

Hypothyroidism is a major cause of secondary hypercholesterolemia. Amiodarone treatment alters both the levels of serum lipids and thyroid hormones. We investigated whether the amiodarone-induced changes in lipid metabolism are related to the changes in thyroid hormone levels. Eighteen patients received amiodarone (31 +/- 3 g cumulative dose) for six weeks. Serum triglyceride, total-cholesterol, high density lipoprotein-cholesterol and its subfractions, apolipoproteins B and AI, and plasma post-heparin lipoprotein lipase and hepatic triglyceride lipase activities were determined. Amiodarone treatment caused significant increases in serum total-cholesterol (baseline 4.4 +/- 0.21 (SE), 6 weeks 5.12 +/- 0.26 mmol/l, P less than 0.01), in low density lipoprotein cholesterol (baseline 2.61 +/- 0.26, 6 weeks 3.36 +/- 0.21 mmol/l, P less than 0.05) and in apolipoprotein B (baseline 1.95 +/- 0.15, 6 weeks 2.26 +/- 0.13 mmol/l, P less than 0.01) concentrations. Serum high density lipoprotein and its subfractions, or apolipoprotein AI levels did not change. Plasma post-heparin lipoprotein lipase activity increased (baseline 137 +/- 21, 6 weeks 168 +/- 21 U/ml, P less than 0.01) while hepatic triglyceride lipase did not change. Amiodarone also caused an increase in serum thyroxine (baseline 110 +/- 8, 6 weeks 136 +/- 6 mmol/l, P less than 0.05), although values remained in euthyroid range. In summary, amiodarone therapy increased the concentrations of atherogenic lipoproteins in the serum similar to that seen in hypothyroidism. On the other hand the effect of amiodarone on lipoprotein lipase was opposite to that seen in hypothyroidism. Therefore, amiodarone-induced changes in lipid metabolism cannot be explained solely on the basis of the changes in circulating thyroid hormone levels.

Aged↗
PubMed1990

Comparative incidence rates of end-stage renal disease treatment by state.

End-stage renal disease (ESRD) treatment rates vary significantly between states in the United States. Much of this variation relates to the much higher rate of ESRD in blacks and the differences in race, age, and sex composition of various states. Even after adjusting for race, age, and sex differences utilizing data from new patients reported to Medicare with ESRD between 1980 and 1983, marked variation in treatment incidence rates per million population were still present. Overall rates varied from 45 in North Dakota to 99 in New Jersey. Regional rate patterns were demonstrated with very high rates in southwestern states (Texas, New Mexico, Arizona, and California: 87-91/million). In contrast, several south-central states had lower rates (Arkansas, Louisiana, Mississippi, Alabama, and Tennessee: 66-75/million). By state the rates for blacks were consistently higher than for whites. After adjustment for sex and age differences, the rates for blacks varied from 125 in Arkansas to 242 in New Jersey. Several north-eastern states (Massachusetts, Connecticut, Rhode Island, New Jersey) had higher rates of ESRD in blacks (197-242 million) as compared with several south-central states (Arkansas, Louisiana, Mississippi, Tennessee, Alabama) where rates varied from 125 to 180 million. ESRD rates by primary etiologies by state showed marked variation of the major primary etiologies of ESRD: diabetic nephropathy rates were most predictive of overall ESRD rates, with much higher rates in the southwestern states (28.1-33.2) as compared with the south-central states (12.8-16.3).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Reemployment following implantation of the automatic cardioverter defibrillator.

One hundred one patients who received an implantable automatic cardioverter defibrillator (ACD) were evaluated to determine the reemployment rate and factors associated with return to work. Forty-seven were employed before ACD implantation. Their mean (+/- standard deviation) age was 53 +/- 11 years, 83% were men, 75% had coronary artery disease, 76% presented with cardiac arrest and 28% had concomitant cardiac surgery. The mean ejection fraction of these patients was 0.41 +/- 0.15. At follow-up, 29 patients (62%) had resumed work at 11 +/- 9 weeks after implantation. Those who returned to work were better educated (15 vs 11 years, p less than 0.001) and less likely to have a history of prior myocardial infarction (p less than 0.05). There were no significant differences between patients who returned to work and those who did not in terms of age, sex, race, functional class, ejection fraction, extent of coronary artery disease, reason for ACD, or concomitant surgery. Multivariate analysis revealed that level of education was the single best predictor of reemployment status. The only other factors found to add significant predictive power in a stepwise analysis were extent of coronary artery disease and marital status. The model using these 3 variables had a sensitivity of 83% and a specificity of 72%. It was concluded that (1) most patients employed before ACD implantation are able to return to work after the procedure, and (2) nonmedical factors play an important role in the resumption of work-related activities. These findings have important quality-of-life and cost-effectiveness implications for ACD implantees.

Aged↗
PubMed1988

Atrial sensing to augment ventricular tachycardia detection by the automatic implantable cardioverter defibrillator: a utility study.

The triggering of automatic implantable cardioverter defibrillator (AICD) discharges by supraventricular tachycardias, despite the presence of a probability density function algorithm, remains a limitation of an otherwise highly effective device. We systematically investigated the diagnostic utility which theroretically could derive form the addition of atrial sensing capability to the AICD in 25 patients with 30 inducible sustained monomorphic ventricular tachycardias (VTs) at clinically relevant rates (greater than or equal to 150 beats/min). Patients were included only if they were not taking medication capable of depressing ventriculoatrial (VA) conduction for at least 5 half-lives prior to electrophysiological testing. We tested the simple criterion for VT that ventricular cycle length (CL) be shorter than the atrial CL (not met in sinus or most other supraventricular tachycardias). Mean VT CL was 283 +/- 47 ms (range 210 to 370). In 25 (83%) VTs, the VT criterion was consistently satisfied. Of the five cases in which the criterion was not met, 1:1 VA conduction during VT was present in four, three of which initially manifested 2:1 VA conduction lasting from 14 to 28 s and therefore would have transiently fulfilled the VT criterion. The remaining patient who failed to satisfy the VT criterion had ongoing atrial flutter during a relatively slower sustained VT, but this circumstance could be recognized because of the varying AV interval. The absence of 1:1 VA conduction at CLS less than or equal to 400 ms during ventricular pacing accurately predicted the absence of 1:1 VA conduction during VT in 95% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Evaluating health promotion: a longitudinal quasi-experimental design.

A quasi-experimental research design is used to evaluate Carolina Healthstyle, a health promotion project for South Carolina state employees. A 10% stratified random sample of employees was surveyed in the Spring of 1983 and again in 1984. Eighteen agencies were intervention agencies and the rest comparison that year. This article reports changes with simple before-after comparisons in the intervention agencies and matched pair analysis and randomized block designs to compare intervention and comparison agencies. Results are reported for smoking, exercise safety, nutrition, stress, and alcohol. Significant increases in exercise were found in both intervention and comparison agencies. The number of smokers decreased in intervention from 30%-26% with no change in comparison agencies. Safety practices changed at similar rates in both intervention and comparison groups. Consumption of chicken increased significantly only in the intervention agencies. Few other diet or stress changes were found. There were changes in alcohol consumption in intervention agencies only. The presence of the comparison group helps to separate the program effects from secular trends.

Adolescent↗