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Biomedical subjects

C C Johnson

Publications and source records attributed to C C Johnson.

At least 91 records · Page 5Linked to original sources
PubMed1995

Demographic differences in referral rates to neurologists of patients with suspected Parkinson's disease: implications for case-control study design.

Although patients with Parkinson's disease (PD) are often treated by neurologists, most are first diagnosed by a primary care physician. Epidemiologic studies which use PD cases from only neurology clinics may be subject to referral bias due to differential case selection in the referral process. To study this methodological issue, a historical cohort study of all outpatients with PD diagnosed by a non-neurologist from January 1, 1988 to June 1, 1992 at the Henry Ford Health System was conducted. This health system has specialty and primary care outpatient clinics located at the main facility in Detroit, Mich. and throughout the metropolitan area. The analysis included those who had at least one outpatient visit during the follow-up period from January 1, 1988 to June 30, 1993 (n = 588), of whom 183 (31.1%) were referred to a neurologist. The univariate analysis resulted in crude risk ratios for referral of 2.14 [95% confidence interval (CI) = 1.56-2.93] for age less than 70, 2.11 (95% CI = 1.57-2.84) for male sex, 1.64 (95% CI = 1.17-2.32) for nonwhite race, 2.48 (95% CI = 1.77-3.47) for private health insurance, 1.79 (95% CI = 1.32-2.43) for being married, 1.44 (95% CI = 1.08-1.92) for 10 or more health care visits per year and 2.27 (95% CI = 1.66-3.11) for having the initial visit for PD at the main Detroit clinic. In a Cox proportional hazards model which included all study variables, race and marital status were no longer statistically significant (p < 0.05), and no risk estimates were greater than 2.0. In summary, patients referred to neurologists in this study were more likely younger, male, to have private health insurance, frequent users of health care and to use hospital-based clinics for their primary health care. We suggest that future case-control studies of PD avoid potential referral bias by not using a study population comprised solely of patients referred to a neurology clinic or design studies which can estimate the potential effect of this bias.

Age Distribution↗
PubMed1995

Alcohol consumption among adolescents and young adults: the Bogalusa Heart Study, 1981 to 1991.

This report describes the alcohol consumption of adolescents and young adults who participated in the Bogalusa Heart Study, 1981 to 1991. Data were collected in three cross-sectional surveys of school-age children (11 to 19 years) and three surveys of young adults (18 to 32 years). White males had the highest proportion of drinkers and Black females had the lowest. By the end of the decade, adult White and Black male drinkers were about equal. Most individuals drank once or twice a week, but daily drinkers had the highest weekly alcohol intake. An association between alcohol and high-density lipoprotein cholesterol was found only in the latest survey and probably reflects the aging of the cohort.

Adolescent↗
PubMed1995

The CQI paradigm: a pathway to nurse empowerment in a community hospital.

Anderson Area Medical Center instituted continuous quality improvement (CQI) hospitalwide two years ago. Three teams were challenged with identifying and improving processes related to accounts receivable. X-ray report turn-around-time, and emergency department patient satisfaction. Nursing participation was sought for all three teams. An eight-step CQI process was used to identify, analyze, and improve these three processes. Substantial nursing participation in these pilot CQI teams led to further participation in many other CQI teams optimizing clinical processes. Nursing personnel gained opportunities to make significant contributions to the enhancement of clinical and administrative processes in a large hospital. Nurses learned to work with other members of the health care team outside of their traditional domains, and this, combined with formalized training in the team process, is empowering.

Accounts Payable and Receivable↗
PubMed1995

Newer penicillins and beta-lactamase inhibitors.

Penicillins continue to be essential antibiotics for the treatment and prophylaxis of many infectious diseases. Recent advances have resulted in compounds with favorable new antimicrobial and pharmacologic properties. This article reviews the spectrum of activity, toxicity, pharmacokinetics, and clinical uses of the extended spectrum penicillins and the beta-lactamase inhibitor combination agents.

Animals↗
PubMed1995

Lowering physician hospital resource consumption using low-cost low-technology computing.

Anderson Area Medical Center physicians have been provided disease and procedure specific profiles of their practice experience for more than five years. For four years, physicians were provided reporting, in a variety of formats, detailing their clinical outcomes and consumption of hospital resources in treating patients with acute myocardial infarction (AMI), pneumonia, cholecystectomy, stroke, congestive heart failure (CHF), and total hip replacement. For the past eighteen months physicians have been provided a uniform format of monthly physician-specific reporting for stroke, AMI, pneumonia, diabetes, CHF, cholecystectomy, total hip replacement, newborn delivery, angina, and hernia repair. Using only a modest PC platform with database, word processing, and graphics programs operating in a DOS environment, an effective disease/procedure reporting program is provided to medical staff with 3 person-days of effort per month.

Computer Systems↗
PubMed1994

Cytochrome P450-catalyzed hydroxylation of hydrocarbons: kinetic deuterium isotope effects for the hydroxylation of an ultrafast radical clock.

The ultrafast radical clock probe trans-1-methyl-2-phenylcyclopropane (1CH3) and its mono-, di-, and trideuteriomethyl analogues were oxidized by phenobarbital-induced rat liver microsomal enzymes. This cytochrome P450-catalyzed hydroxylation of 1CH3 gave three products: the alcohol trans-(2-phenylcyclopropyl)methanol (2), the rearranged alcohol 1-phenylbut-3-en-1-ol (3), and the phenol trans-2-(p-hydroxyphenyl)-1-methylcyclopropane (4). The identification of both the unrearranged and rearranged products of oxidation, 2 and 3, is consistent with the formation of a radical intermediate via a hydrogen atom abstraction from the methyl group by the catalytically active iron-oxo center. Hydroxylation of three deuteriomethyl forms of 1CH3 produced the analogous deuterated products, although in different amounts of each. Perdeuteration of the methyl group (1CD3) disfavored oxidation at the methyl group and caused an increase in the oxidation of the phenyl ring (metabolic switching). By comparing the amounts of alcohols and phenol formed from the individual, noncompetitive oxidation of 1CH3 and 1CD3 the overall (i.e., combined primary and secondary) deuterium kinetic isotope effect (DKIE) was found to be 12.5. Intramolecular DKIEs for 1CHD2 and 1CH2D were 2.9 and 13.2, respectively. From these results, the primary and secondary DKIEs were calculated to be 7.87 and 1.26, respectively, values that indicate that there is extensive C--H bond stretching in the transition state for the rate-controlling step in P450-catalyzed hydroxylation of 1CH3.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Coping styles in women with premenstrual syndrome.

Sixty-five women with a prospectively confirmed diagnosis of premenstrual syndrome (PMS) were subdivided on the basis of their scores on the Beck Depression Inventory (BDI) into high-depression and low-depression groups and compared with 49 non-PMS control women on self-administered measures of coping and anxiety. The high-depression PMS group was found to utilize significantly more avoidant coping styles in dealing with stressors independent of the premenstrual phase. Implications for treatment are discussed.

Adaptation, Psychological↗
PubMed1994

Successful recruitment strategies for school-based health promotion: experiences from CATCH.

School-based research designs in the 1990s often require that a large number of schools be recruited to participate in studies. Therefore, effective recruitment and maintenance of schools becomes an important activity for ensuring the integrity of the study design. The Child and Adolescent Trial for Cardiovascular Health (CATCH) is the largest school-based health promotion research project yet undertaken; 96 schools (24 per field site) were successfully recruited and retained for this cardiovascular disease risk reduction project. This article describes general recruitment strategies used at the four CATCH sites, a description of how Social Learning Theory guided these activities, a discussion of logistical considerations, and recommended recruitment strategies for future school-based research.

Community Participation↗
PubMed1994

Design of process evaluation within the Child and Adolescent Trial for Cardiovascular Health (CATCH).

Process evaluation complements outcome evaluation by providing data to describe how a program was implemented, how well the activities delivered fit the original design, to whom services were delivered, the extent to which the target population was reached, and factors external to the program that may compete with the program effects. The process evaluation system used in the Child and Adolescent Trial for Cardiovascular Health (CATCH) is presented in this paper. The conceptual model underlying the CATCH process evaluation system is described, and process measures and data collection protocols are reviewed. Functions of process evaluation data in the trial include: (1) describing the implementation of the program, (2) quality control and monitoring, and (3) explaining program effects. The importance of incorporating process evaluation into final outcome analyses and assessments of program impact is emphasized.

Adolescent↗
PubMed1994

CATCH: family process evaluation in a multicenter trial.

The Child and Adolescent Trial for Cardiovascular Health (CATCH) is an elementary school cardiovascular health education field trial in progress in San Diego, California, New Orleans, Louisiana, Minneapolis, Minnesota, and Austin, Texas. Because a significant part of a child's health behaviors are shaped within the home, CATCH is evaluating whether the effects of the school-based program are enhanced by the inclusion of a home-based program. A 7 x 7 x 10 randomized design with 7 school-only and 7 school-plus-family intervention schools, along with 10 control schools is implemented at each site. The CATCH family intervention is implemented during Grades 3 through 5 and consists of home-based curricula and Family Fun Nights focusing on healthier eating and increased physical activity during Grades 3 and 4, along with a smoking prevention curriculum in Grade 5. CATCH is examining the effectiveness of family (household) involvement through changes in students' dietary intake of fat and sodium. This paper describes the process evaluation methods used to document the extent of participation in the family program. Data reported for the third-grade Family Fun Nights held in the 28 family schools across all sites reflected an average student participation rate of 67%. The average family member to student ratio was approximately 2:1. Participation by all third-grade teachers and the majority of physical education specialists was observed.

Adolescent↗
PubMed1994

CATCH: challenges of conducting process evaluation in a multicenter trial.

This paper discusses the challenges faced when collecting process evaluation information in a school-based, multicenter field trial. Experiences from the Child and Adolescent Trial for Cardiovascular Health (CATCH) are shared as a means of illustrating the challenges that are presented and ways of meeting the challenges. The scope and magnitude of the trial (96 schools across four sites) and the diverse population participating in the trial (including children and adults representing a cultural and socioeconomic mix) present challenges that are compounded by conducting research in a highly structured school setting. In such a trial, thoughtful consideration must be paid to what data should be collected, how data should be collected, how to collect data on tailored interventions, gaining and maintaining schools' cooperation, collecting data in year-round schools, and assuring data quality.

Adolescent↗
PubMed1994

Parkinson's disease and its comorbid disorders: an analysis of Michigan mortality data, 1970 to 1990.

Using data from death certificates, we compared underlying causes of death for two populations of Michigan decedents: (1) persons 40 years of age and older for whom Parkinson's disease (PD) was listed as a contributing cause of death and who died in the years 1970 through 1989, and (2) all persons in Michigan over 40 years of age who died in 1970, 1980, or 1990. PD decedents were approximately 1.5 times more likely to die from cerebrovascular disease and three to four times more likely to die from pneumonia/influenza, but they had just 29% of the expected number of deaths due to cancer. These associations were maintained irrespective of gender or race. PD decedents had diabetes mellitus and heart diseases as frequently as decedents in the general population, but liver diseases were less frequent among PD decedents. These trends held throughout the 21-year study period. When we stratified cancers by whether they are known to be (1) highly related, (2) moderately related, or (3) weakly related or unrelated to smoking, there were still 2.5 times fewer cancers unrelated or weakly related to smoking among PD decedents than among decedents in the general population. We believe that the greater frequency of cerebrovascular disease in PD decedents may be due to a detection bias, since PD patients are more likely to be seen by neurologists, who are more apt to diagnose and document diseases of the nervous system. Pneumonia/influenza is more common among PD patients because of their relative immobility near the end of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Posterior cruciate ligament strain biomechanics in total knee arthroplasty.

To evaluate the role of the posterior cruciate ligament in total knee arthroplasty, 8 normal whole-leg cadaveric legs were studied. Strain patterns of the posterior cruciate ligament were measured during active and passive knee flexion extension. Total knee arthroplasty was performed, and posterior cruciate ligament strain was measured again. The standard tibial insert was removed, and 3 additional tibial trays were used: flat, 10 degrees sloped, and 15 degrees sloped. The posterior cruciate ligament strain was recorded for each tibial insert. Total knee arthroplasty with a standard insert produced a large range of posterior cruciate ligament strain values (+/- 6%). Of the 8 specimens, 3 produced excessively taut posterior cruciate ligament strain, 3 were slack, and 2 returned strain to the baseline strain value. Changing the surface contour and slope of the tibial inserts did not produce any consistent change in the posterior cruciate ligament strain pattern. The ability of total knee arthroplasty to reproduce normal posterior cruciate ligament strain behavior has not been demonstrated.

Biomechanical Phenomena↗
PubMed1993

Parkinson's disease mortality and the industrial use of heavy metals in Michigan.

Parkinson's disease (PD) mortality rates in Michigan counties for 1986-1988 were calculated with respect to potential heavy metal exposure (iron, zinc, copper, mercury, magnesium, and manganese) from industry based on recent census data. Individuals were counted as a PD death if the diagnosis was listed as an "underlying" or "related" cause of death on the death certificate. Counties with an industry in the paper, chemical, iron, or copper related-industrial categories (ICs) had statistically significantly (p < 0.05) higher PD death rates than counties without these industries. Significant correlations of chemical (rs = 0.22; p = 0.05), paper (rs = 0.22; p = 0.05) and iron (rs = 0.29; p = 0.008) industry densities with PD death rates were also present. Counties were divided into high (> 15/100,000 individuals 45 years old and over) and low (< = 15/100,000) PD death rate counties by cluster analysis. Geographically, counties with high PD mortality were located mainly in the southern half of the lower peninsula and eastern half of the upper peninsula; low PD death rate counties formed two distinct clusters in the western edge of the upper peninsula and the north-central portion of the lower peninsula. Other possible risk factors that may explain the varied distribution of PD death rates in Michigan were examined. Those significantly correlated with PD mortality included population density (rs = 0.31; p = 0.005), farming density (rs = 0.25; p = 0.02), and well water use (rs = -0.24; p = 0.03). These ecologic findings suggest a geographic association between PD mortality and the industrial use of heavy metals.

Aged↗
PubMed1993

Susceptibility of anaerobic bacteria to beta-lactam antibiotics in the United States.

beta-Lactam antibiotics are critical agents in the treatment of anaerobic infections. Susceptibility to these agents, however, varies widely, depending on the specific drug and organism; has not been constant over time; and differs in various geographic locations within the United States for many species. For the organisms in the Bacteroides fragilis group, the beta-lactam antibiotics with the most consistent activity are imipenem and combinations of a beta-lactam drug plus a beta-lactamase inhibitor, such as ticarcillin/clavulanate and ampicillin/sulbactam. Antibiotics with less activity include cefoxitin, piperacillin, cefotetan, and ceftizoxime. In other species of anaerobic gram-negative bacilli, beta-lactamase production is seen with increasing frequency. In vitro susceptibility of these strains is now similar to that of the B. fragilis group, with imipenem, ticarcillin/clavulanate, ampicillin/sulbactam, and cefoxitin being the most active drugs. The anaerobic gram-positive cocci and bacilli remain, for the most part, highly susceptible to penicillins and imipenem.

Anti-Bacterial Agents↗
PubMed1993

The bactericidal activity of magainins against Pseudomonas aeruginosa and Enterococcus faecium.

The antimicrobial activities of two synthetic magainins, MSI 94 and MSI 93, were investigated in vitro against 20 clinical isolates each of Pseudomonas aeruginosa and Enterococcus faecium. The ranges of the MICs of both agents were 6.25-50 mg/L for P. aeruginosa and 3.13-12.5 mg/L for E. faecium. In time-kill studies, the magainins demonstrated rapid, concentration-dependent bactericidal activity against selected isolates of both species. This bactericidal effect was inoculum-dependent for P. aeruginosa in both the logarithmic and stationary phases of growth. Bacterial regrowth was regularly observed after 24 h of incubation in the time-kill studies; this was due to loss of antimicrobial activity during overnight incubation rather than to the development of resistance. More rapid and sustained bactericidal activity was noted when the magainins were combined with either silver nitrate (AgNO3) or gentamicin against P. aeruginosa and with gentamicin against E. faecium. Neither agent produced a post-antibiotic effect on P. aeruginosa.

Animals↗