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Biomedical subjects

C D Jenkins

Publications and source records attributed to C D Jenkins.

At least 19 recordsLinked to original sources
PubMed1996

Predicting completeness of symptom relief after major heart surgery.

The authors hypothesized that the same biopsychosocial factors that raise the risk of illness incidence would influence the speed and completeness of relief from physical symptoms during recovery following cardiac surgery. This multicenter prospective study involved 463 patients aged 35 to 69 years who underwent coronary artery bypass graft or cardiac valve surgery. Predictor data were gathered 1 to 3 days before surgery, and outcome measures were collected 6 months postoperatively. The following predictors were associated with postoperative freedom from cardiac symptoms: fewer preoperative cardiac hospitalizations; low levels of angina, dyspnea, fatigue, and sleep problems; low levels of anxiety, depression, hostility, and life-change events; and high levels of psychosocial well-being, hopefulness, overall satisfaction, and social support. The predictors of not requiring daytime bed rest because of cardiac symptoms during the 6th postoperative month were male gender, higher education, less cardiac disability preoperatively, low levels of angina, dyspnea, sleep problems, depression and fatigue, and absence of Type A behavior and of intraoperative hypotension. By using separate multiple logistic regression equations, the authors identified the variables printed in bold face as independent significant contributors to prediction. Many of the predictors are strong enough and simple enough to be used in clinical practice. Many of them may also predict recovery after acute illnesses and injuries involving other organ systems.

Activities of Daily Living↗
PubMed1996

Comparative intraocular penetration of topical and injected cefuroxime.

AIMS: The choice of a prophylactic antibiotic for cataract surgery is dependent on its antibacterial activity and tissue penetration. The influence of the route and timing of administration of cefuroxime on its intraocular concentrations was examined. METHODS: 120 patients were recruited before cataract surgery into a prospective trial to compare the anterior chamber concentration of cefuroxime at a fixed time after administration by three routes. In a further 110 patients, the interval before sampling was varied in order to permit an examination of the kinetics of penetration. In another 10 patients, cefuroxime was given topically at the completion of surgery to assess the effect of a corneal wound on aqueous penetration. Cefuroxime concentrations were measured by high performance liquid chromatography on 0.2 ml samples of aqueous aspirated from the anterior chamber. Mean aqueous concentrations of cefuroxime for each group were compared using Student's t test. RESULTS: After 25 mg cefuroxime, mean aqueous concentrations increased in the order forniceal (< 0.1 microgram/ml) < topical (0.18 microgram/ml) < subconjunctival (2.31 microgram/ml) when sampled 12-24 minutes after administration. Aqueous concentrations of cefuroxime reached a peak between 80 and 110 minutes after both forniceal and peribulbar injection but were still rising at this time after subconjunctival injection. Topical application of 12.5 mg cefuroxime to eyes with a 10 mm corneal wound resulted in a mean aqueous concentration of 9.34 micrograms/ml. CONCLUSION: In the intact eye, only sub-conjunctival injection resulted in clinically significant aqueous concentrations of cefuroxime (> 1 microgram/ml) between 12 and 24 minutes after administration. For all routes, maximal aqueous concentrations were delayed by at least 80 minutes from administration. In the presence of a corneal wound, high aqueous levels of cefuroxime were rapidly attained after topical application.

Administration, Topical↗
PubMed1995

Endotoxin-mediated dendritic cell release from the intestine. Characterization of released dendritic cells and TNF dependence.

Dendritic cells (DC) acquire Ag in peripheral tissues and transport it to lymph nodes where they efficiently activate resting T cells. We have shown that i.v. endotoxin causes increased release of intestinal DC into lymph. In this paper we further characterize the release of DC and the properties of the released cells. A total of 50 micrograms of endotoxin injected i.v. causes an increase in DC output within 6 h that peaks between 12 and 24 h, with a maximum output of 8 to 15 times normal. At the same time lymphocyte output is markedly decreased. The increased output of DC is followed by a decrease to subnormal levels. The stimulated release of DC is almost totally blocked by a monoclonal anti-TNF-alpha Ab. A second injection of TNF-alpha does not result in further DC release. DC are not released from lymph nodes into efferent lymph by endotoxin. DC collected from lymph after endotoxin treatment show increased expression of the p55 IL-2 receptor and the OX48 Ag but otherwise resemble normal lymph DC. In functional assays they show no significant differences from normal in their ability to stimulate a MLR or to present Ags to sensitized T cells. Immunocytochemistry with the use of MRC OX62 suggests that the DC are released into lymph from the lamina propria of the small intestine. The stimulated release of DC mediated by TNF-alpha may be important in regulating Ag presentation in lymph nodes draining inflammatory sites.

Animals↗
PubMed1995

An integrated behavioral medicine approach to improving care of patients with diabetes mellitus.

A detailed approach to integrating behavioral techniques into patient education, case management, and treatment evaluation of persons with diabetes mellitus is offered. The author asks a series of "what if" questions to stimulate new thinking about ways to improve patient-physician relations in overcoming problems in managing the condition, citing recent research findings in the field. Adherence to regimens, self-management, goals of an integrated diabetes program and steps along the way to achieving it, psychophysiologic mechanisms in glucose metabolism, and the function of social support are among the topics covered.

Behavior Therapy↗
PubMed1994

Effects of antihypertensive medications on quality of life in elderly hypertensive women.

The impact of antihypertensive medications on the quality of life of elderly hypertensive women has rarely been systematically evaluated in large clinical trials using drugs from the new generations of pharmaceutic preparations. We carried out a multicenter, randomized double-blind clinical trial with 309 hypertensive women aged 60 to 80 years to assess effects of atenolol, enalapril, and isradipine on measures of quality of life over a 22-week period. The patients had mild to moderate hypertension. Hydrochlorothiazide was added to treatment if monotherapy was inadequate in lowering blood pressure. At the conclusion of the trial the three drug groups did not differ in degree of reduction of diastolic blood pressure or in supplementation with hydrochlorothiazide. Over the 22-week trial, linear trend analysis showed no differences between the treatment groups in change from baseline on quality of life measures of well-being, physical status, emotional status, cognitive functioning, and social role participation. Regarding each of 33 physical side effects over the 22 weeks, we found no general difference between atenolol, enalapril, and isradipine groups on measures of change in distress over symptoms except for enalapril patients who worsened in distress over cough (P = .001) and atenolol patients who worsened in distress over dry mouth (P = .014). Centering on three medications that are relatively new additions to the armamentarium for blood pressure control, the findings underline the increasing opportunities for the physician to select drugs that can control blood pressure while maintaining the quality of life of elderly hypertensive women.

Aged↗
PubMed1993

Selection and the evolution of genetic life cycles.

The evolution of haploid and diploid phases of the life cycle is investigated theoretically, using a model where the relative length of haploid and diploid phases is under genetic control. The model assumes that selection occurs in both phases and that fitness in each phase is a function of the time spent in that phase. The equilibrium and stability conditions that allow for all-haploid, all-diploid, or polyphasic life cycles are considered for general survivorship functions. Types of stable life cycles possible depend on the form of the viability selection. If mortality rates are constant, either haploidy or diploidy is the only stable life cycle possible. Departures from constant mortality can give qualitatively different results. For example, when survivorship in each phase is a linear, decreasing function of the time spent in the phase, stable haploid, diploid or polyphasic life cycles are possible. The addition of genetic variation at a coevolving viability locus does not qualitatively affect the outcome with respect to the maintenance of polyphasic cycles but can lead to situations where more than one life cycle is concurrently stable. These results show that trade-offs between the advantages of being diploid and of being haploid may help explain the patterns of life cycles found in nature and that the type of selection may be critical to determining the results.

Biological Evolution↗
PubMed1992

Relation of hostility to medication adherence, symptom complaints, and blood pressure reduction in a clinical field trial of antihypertensive medication.

The impact of hostility was examined in relation to the conduct and results of a clinical field trial. Data were derived from a multi-center randomized double-blind study of the comparative effects of antihypertensive therapy (captopril, methyldopa and propranolol) on the quality of life of 620 hypertensive men. Hostility levels were higher in subjects reporting skipping medication dosages compared to those reporting they always complied with the medication schedule. Reporting of symptoms often associated with antihypertensive drug regimens was positively related to hostility scores throughout the study, even during the blinded placebo period. Persons with high hostility scores showed the greatest decline in blood pressure independent of type of antihypertensive medication. However, there was some limited evidence that hostility levels were significantly reduced by one antihypertensive medication. Overall, the present findings suggest that double-blind pharmacologic clinical trials may benefit from using reliable measures of hostility as covariates in the evaluation of symptom reports and amount of blood pressure reduction.

Adult↗
PubMed1992

Assessment of outcomes of health intervention.

This paper proposes that the most comprehensive current approach to the assessment of health interventions is exemplified in the expanding field of research into health-related quality of life. The paper initiates discussion of 11 conceptual and methodological issues which should be dealt with explicitly rather than by default in any such research study. Decisions about these 11 issues will shape the future directions of the field of health outcomes research. Health policy decisions will increasingly be based on outcome studies of health-related quality of life.

Coronary Disease↗
PubMed1992

A two-dimensional intervention plan to reduce risk factors for ischaemic heart disease.

Although most cardiologists and public health officials are convinced of the great value of reducing risk factors for cardiovascular diseases, efforts to reduce these factors have seldom reached effectively beyond those persons in direct touch with physicians. This paper describes nine channels which health officials can utilise to inform, motivate, and change health behaviours in the general public. The channels are: individuals, family and friends, health professionals and institutions, schools and teachers, business and labour, mass media, local organizations, community leaders, regional and national government. Using all these channels in an integrated programme to reduce multiple risk factors in the community results in a two-dimensional intervention plan in which the various components reinforce one another. Specific programmatic suggestions are made for each of the following cardiovascular risk factors: cigarette smoking, high blood pressure, lack of exercise, high serum cholesterol, and stress.

Combined Modality Therapy↗
PubMed1990

The measurement of health-related quality of life: major dimensions identified by factor analysis.

The measurement of quality of life is becoming more important in the evaluation of medical technologies and pharmaceuticals. Particularly when the several available therapies have similar effects on survival, quality of life measures may help decide which should be the therapy of choice. The Recovery Study utilized a multidisciplinary array of indicators of health-related quality of life and recovery. This paper reports factor analyses of 58 outcome measures on a study group of 469 persons who had undergone coronary artery bypass or cardiac valve surgery 6-months previously. The factor analyses revealed 5 orthogonal dimensions. We have named them: low morale, symptoms of illness, neuropsychological function, interpersonal relationships, and economic-employment. The data argue that health-related quality of life is a multidimensional construct, and that these dimensions can be measured quantitatively with relatively simple interview and questionnaire approaches. The next research step is to determine whether the five dimensions of post-operative quality of life have different pre-operative predictors, and whether intervention on these predictors can improve the recovery and rehabilitation process.

Adult↗
PubMed1990

Randomised single blind trial to compare the toxicity of subconjunctival gentamicin and cefuroxime in cataract surgery.

Comparatively little attention has been paid to the conjunctival toxicity of antibiotics administered at the time of cataract surgery. We have observed the effect of subconjunctival gentamicin and cefuroxime injection, using colour photography in a randomised single blind trial of 121 patients undergoing routine cataract surgery. Our results suggest that a hyperaemic eye is likely to occur about twice as often in patients injected with gentamicin (p less than 0.001). Gentamicin is associated with more pain postoperatively (p less than 0.05). Significant manifestations of gentamicin toxicity are conjunctival oedema and capillary closure. Cefuroxime has some theoretical advantages over gentamicin in its antibacterial spectrum.

Cataract Extraction↗
PubMed1989

Genetic segregation and the maintenance of sexual reproduction.

Sexual reproduction confronts evolutionary biology with a paradox: other things being equal, an asexual (all-female) population will have twice the reproductive potential of a competing sexual population and therefore should rapidly drive the sexual population to extinction. Thus, the persistence of sexual reproduction in most life forms implies a compensatory advantage to sexual reproduction. Work on this problem has emphasized the evolutionary advantages produced by the genetic recombination that accompanies sexual reproduction. Here we show that genetic segregation produces an advantage to sexual reproduction even in the absence of an advantage from recombination. Segregation in a diploid sexual population allows selection to carry a single advantageous mutation to a homozygous state, whereas two separate mutations are required in a parthenogenetic population. The complete fixation of advantageous mutations is thus delayed in a heterozygous state in asexual populations. Calculation of the selective load incurred suggests that it may offset the intrinsic twofold reproductive advantage of asexual reproduction and maintain sexual reproduction in diploid populations.

Animals↗
PubMed1989

Type A, amicability and injury: a prospective study of air traffic controllers.

Recent research has suggested that only a subset of Type A's may be at higher risk for negative health outcomes. The present prospective study of 416 air traffic controllers attempted to determine if a sub-group of Type A's who were disliked by their co-workers had significantly higher risk of injury than liked A's and all Type B's over a 27-month period. Liked B's were not different in terms of injury incidence from their not liked B counterparts (mean annualised rates of injury = 1.9 and 2.1 respectively); not liked Type A's had the highest rates of injuries of any group (8.5) including liked Type A's (3.8). Some psychological instruments were useful in discriminating the Type A not liked group from their liked counterparts and from the Type B's. These discriminating variables were used as covariates to determine if the relationship between being classified a not liked Type A and elevated injury incidence remained. Multiple regression analysis showed that distress from life events and being a not liked Type A remained significantly correlated with later injury (standardised coefficients 0.16 and 0.25 respectively).

Adult↗
PubMed1988

A scale for the estimation of sleep problems in clinical research.

Problems in sleeping are widely prevalent in modern society and are often one of the presenting complaints of patients consulting physicians. In addition, there is scattered epidemiologic evidence and considerable clinical support that disturbed or inadequate sleep may be a risk factor for clinical emergence of cardiovascular disease and for total mortality. The role of sleep problems both as a precursor and as a sequela of disease states could be better delineated in large groups by the availability of a brief, reliable and standardized scale for sleep disturbance. Such a scale could also be used to evaluate the impact of different therapies upon sleep problems. This paper presents data from two study populations responding to three and four item self-report scales. From 9 to 12% of air traffic controllers reported various sleep problems to have occurred on half or more of the days during the prior month, whereas 12-22% of patients 6 months after cardiac surgery reported such frequent sleep problems. Utilizing data from the 6 and 12 month follow-ups, test-retest reliability of the three-item scale in cardiac surgery patients was found to be 0.59. Internal consistency coefficients for the three and four-item scales were 0.63 and 0.79 respectively.

Adult↗