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Biomedical subjects

J Cooper

Publications and source records attributed to J Cooper.

At least 91 records · Page 5Linked to original sources
PubMed2000

Reaction of mock jurors to testimony of a court appointed expert.

A study was conducted to assess the impact of court appointed experts on the judgments of mock jurors. A civil proceeding was adopted for the experiment. Mock jurors heard testimony about a plaintiff's injury in an automobile accident. In some conditions, medical testimony for the plaintiff and defendant was provided by experts hired by each side. In other conditions, a medical expert appointed by the court testified in addition to the two adversarial experts. In one of these conditions, the court expert sided with the plaintiff; in another, the expert sided with the defendant. The plaintiff in the case was always an individual. The defendant was sometimes a corporation and sometimes an individual. The results showed that mock jurors sided with the court appointed expert in every condition except when the expert favored a corporate defendant. The results were discussed in terms of heuristic processing of persuasive information.

Criminal Law↗
PubMed2000

Human alpha6 AChR subtypes: subunit composition, assembly, and pharmacological responses.

Many nicotinic acetylcholine receptor (AChR) subunits are known to be co-expressed with the alpha6 subunit in neurons. Because alpha6beta4 AChRs assemble inefficiently and alpha6beta2 AChRs not at all, more complex mixtures of human subunit cDNAs were tested for their abilities to form functional AChRs when expressed in Xenopus oocytes. alpha6beta4beta3 AChRs produced the largest and most consistent responses. alpha6alpha3beta2 AChRs exhibited reduced potency for ACh and increased potency and efficacy for nicotine compared to alpha3beta2 AChRs, but similar resistance to functional inactivation after prolonged exposure to nicotine. alpha6alpha4beta2 AChRs differed little in potency or efficacy for ACh or nicotine compared to alpha4beta2 AChRs, and had similarly high sensitivity to inactivation by prolonged exposure to nicotine. Co-expression of alpha6 and beta2 cRNAs resulted in large numbers of (3)H-epibatidine binding sites in the form of large aggregates but not in functional pentameric AChRs. Co-expression of alpha6, beta2, and alpha5 resulted in assembly of some functional pentameric AChRs. Chimeras with the large extracellular domain of alpha6 and the rest from either alpha3 or alpha4 efficiently formed functional AChRs. Thus, the extracellular domain of alpha6 efficiently assembles with beta2 to form ACh binding sites, but more C-terminal domains cause difficulties in forming pentameric AChRs. Chimeric alpha6/alpha3 and alpha6/alpha4 AChRs containing either beta2 or beta4 subunits were blocked by alpha-conotoxin MII which had previously been reported to be specific for alpha3beta2 AChRs.

Animals↗
PubMed2000

The "hired gun" effect: assessing the effect of pay, frequency of testifying, and credentials on the perception of expert testimony.

Three experiments addressed the proposition that jurors use short cuts in processing information when confronted with expert scientific testimony. The results of the first two studies demonstrated that experts who are highly paid for their testimony and who testify frequently are perceived as "hired guns." They are neither liked nor believed. The results of the third experiment replicated the hired gun effect and showed that it is most likely to occur when the testimony is complex and cannot be easily processed. The results were discussed in terms of the theoretical differences between central and peripheral processing of persuasive messages in a legal context.

Adolescent↗
PubMed2000

The Bayesian approach improves the electrocardiographic diagnosis of broad complex tachycardia.

Despite numerous attempts at devising algorithms for diagnosing broad complex tachycardia (BCT) on the basis of the electrocardiogram (ECG), misdiagnosis is still common. The reason for this may lie with difficulty in implementing existent algorithms in practice, due to imperfect ascertainment of ECG features within them. An attempt was made to approach the problem afresh with the Bayesian inference by the construction of a diagnostic algorithm centered around the likelihood ratio (LR). Previously studied ECG features most effective in discriminating ventricular tachycardia (VT) from supraventricular tachycardia with aberrant conduction (SVTAC), according to their LR values, were selected for inclusion into a Bayesian diagnostic algorithm. A test set of 244 BCT ECGs was assembled and shown to three independent observers who were blinded to the diagnoses made at electrophysiological study. Their diagnostic accuracy by the Bayesian algorithm was compared against that by clinical judgement with the diagnoses from EPS as the criterial standard. Clinical judgement correctly diagnosed 35% of SVTAC, 85% of VT, and 47% of fascicular tachycardia. In comparison, by the Bayesian algorithm devised, 52% of SVTAC, 95% of VT, and 97% of fascicular tachycardia were correctly diagnosed. The Bayesian algorithm devised has proved to be superior to the clinical judgement of the observers who participated in this study, and theoretically will obviate the problem of imperfect ascertainment of ECG features. Hence, it holds the promise for being an effective tool for routine use in clinical practice.

Algorithms↗
PubMed2000

Accommodative and vergence findings in ocular myasthenia: a case analysis.

Myasthenia gravis (MG) is a neuromuscular disorder that affects skeletal muscles, in particular, the extraocular muscles. Response variability is a hallmark sign. Detailed findings are described in a patient with MG in which the presenting sign was accommodative insufficiency. Objective accommodative findings were recorded 3 years before the onset of myasthenia, soon after the initial diagnosis was made, and then after the treatment commenced with pyridostigmine. In addition, clinical measurements were obtained periodically at different times of the day for various binocular motor functions, including near point of convergence, phoria, fusional and accommodative amplitudes, and relative accommodation. The disease adversely affected all accommodative and vergence findings, with fatigue being the primary disturbance. The therapeutic administration of pyridostigmine improved static measurements of accommodation and vergence and reduced asthenopia. The objective dynamic measurements of accommodation, vergence, and versions were less affected. These findings provide a clear demonstration that both intrinsic and extrinsic ocular muscles may be affected in the prepresbyopic myasthenic patient.

Accommodation, Ocular↗
PubMed2000

Out-of-area travel from rural and urban counties: a study of ambulatory care sensitive hospitalizations for New York State residents.

Rural patients who are admitted to hospitals outside their residence county or who travel great distances for hospitalization deprive local rural hospitals of revenue. To provide more information about such rural residents, we studied their characteristics compared to those admitted in the same county. Characteristics studied included illness severity, demographics and county resources. To validate the findings and to provide a different analytic approach, characteristics of residents who travel long distances for admission were also studied. We studied admissions for ambulatory care sensitive conditions, as they might be most responsive to policy changes such as increasing recruitment of local primary-care physicians. Hospital discharges during 1994 for 248,656 New York State residents were studied. We constructed multivariate models using logistic regression and ordinary least squares methods. The models were applied to residents in three types of geographic location along an urban-rural continuum. Outside admissions were associated with younger age, higher illness severity and fewer county hospital resources. Same county admissions were associated with nonwhite race, and lack of insurance. Surprisingly, in rural counties, outside admissions were directly associated with increased primary-care providers. Results from the distance model generally supported findings from the outside admission model.

Ambulatory Care↗
PubMed2000

The effect of age and duration of disease on airway structure in fatal asthma.

We hypothesized that if airway remodeling is related to duration of asthma, that when matched for severity, the airways of older adults should show greater alterations than the airways of younger adults. Using standard morphometric techniques, we compared airways with basement membrane perimeters (Pbm) between 2 and 10 mm from young individuals who died of asthma (n = 14, range 17-23 yr), and older individuals with fatal asthma (n = 13, range 40-49 yr). Comparisons were also made with normal airways from age-matched adults. Wall area was increased in old individuals with fatal asthma compared with young individuals with fatal asthma, primarily due to greater adventitial area, whereas wall area in young individuals with fatal asthma was not different from control subjects. Within muscle bundles the connective tissue matrix was increased around individual cells in individuals with asthma, unrelated to age. After adjustment for this change, smooth muscle area in both asthma groups was still greater than in age-matched control subjects, in old individuals with fatal asthma 4-fold greater (p = 0.04), and in young individuals with fatal asthma 2-fold greater (p = 0.03). Airway narrowing was increased in old versus young individuals with fatal asthma, with both groups more narrowed than control subjects. Intralumenal obstruction and subepithelial collagen in the two asthma groups were significantly greater than in control subjects, but there was no age effect. These data provide support for the hypothesis that there is an increase in airway wall area, including smooth muscle, and airway narrowing with increasing duration of severe asthma or with older age. The observation that total wall thickness was not greater in young individuals with young fatal asthma than in control subjects suggests that factors other than airway wall geometry contribute to the pathogenesis of fatal attacks in this age group.

Adolescent↗
PubMed2000

Curative radiotherapy for anterior commissure laryngeal carcinoma.

There is continuing controversy surrounding the most effective treatment of glottic carcinoma involving the anterior commissure (AC). Surgery has been the preferred method of treatment, since studies previously indicated early tumor invasion of the thyroid cartilage at the AC, thereby assuming less curability by radiotherapy (RT). Subsequent laryngeal anatomic studies and refinement of RT techniques have brought into question the ineffectiveness of curative irradiation. A retrospective review of 174 patients with early-stage glottic carcinoma treated with standard fractionation curative RT revealed 34 patients with T1 and T2 lesions involving the AC. Allowing for a follow-up of at least 3 years, we observed only a 12% (4 of 34 patients) local recurrence rate after RT alone, with excellent voice quality and no major complications related to the irradiation. The 4 local recurrences were controlled by total laryngectomy, although 2 patients developed distant metastatic disease. Radiotherapy represents an effective method of treating T1 squamous cell carcinoma of the glottis with AC involvement. The small number of T2 glottic carcinomas in this study prevents a meaningful conclusion concerning treatment of these lesions.

Aged↗
PubMed2000

Selenium and immunocompetence in patients with head and neck cancer.

This randomized double-blind placebo-controlled study aimed to determine whether oral intake of 200 microg/d of sodium selenite, a dose within the safe and adequate daily intake (50-200 microg/d) recommended by the U.S. Food and Nutrition Board, will abrogate depressed or enhance normal-level immune functions of patients receiving therapy for squamous cell carcinoma of the head and neck. Subjects were given one selenium/placebo tablet/d for 8 wk, beginning on the day of their first treatment for the disease (e.g., surgery, radiation, or surgery and radiation) and their immune functions were monitored. Supplementation with selenium (Se) during therapy resulted in a significantly enhanced cell-mediated immunue responsiveness, as reflected in the ability of the patient's lymphocytes to respond to stimulation with mitogen, to generate cytotoxic lymphocytes, and to destroy tumor cells. The enhanced responsiveness was evident during therapy and following conclusion of therapy. In contrast, patients in the placebo arm of the study showed a decline in immune responsiveness during therapy, which was followed, in some patients, by an enhancement, but the responses of the group remained significantly lower than baseline values. The data also show that at baseline, patients entered in the study had significantly lower plasma Se levels than healthy individuals, and patients in stage I or II of disease had significantly higher plasma selenium levels than patients in stage III or IV of disease.

Adult↗
PubMed2000

A modified pure tone audiometry technique for medico-legal assessment.

A modified method of pure tone audiometry (PTA) in which the auditory threshold is approached from silence in ascending steps, with tone presentations of 1-4 seconds and interval durations of 1.5-5 seconds was assessed against the British Society of Audiology (BSA) method of PTA in terms of its ability to establish valid thresholds in cases of non-organic hearing loss, prevalent in medico-legal testing. The results reveal that the modified technique of PTA is a valid threshold measurement for honest subjects, and yields less non-organic overlay than the standard method of PTA in cases of non-organic hearing loss.

Adult↗
PubMed2000

Critical care bug team: a multidisciplinary team approach to reducing ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia rates in the medical-surgical intensive care unit first exceeded the 90th percentile in September 1997 and were significantly (P <.05) higher than National Nosocomial Infections Surveillance System pooled mean data. In January 1998, a multidisciplinary "Critical Care Bug Team" was developed by the Infection Control Committee to review 1997 National Nosocomial Infections Surveillance System data for four adult intensive care units in a 583-bed tertiary care hospital. METHODS: Membership included clinical nurse specialists, a dietitian, a pharmacist, a respiratory therapist, an infection control professional, a research specialist, and a physician adviser. Having the team report directly to the hospital's Infection Control and Adult Critical Care Committees maximized support for recommendations and provided a direct link from patient care to hospital administration. By identifying issues, evaluating patient care processes, performing literature searches, and monitoring compliance, the team implemented numerous interventions, including policy and procedure changes, purchasing of equipment, and implementation of various education tools. RESULTS: Each member of the Critical Care Bug Team contributed to a synergized effort that may have produced the desired outcome of decreasing ventilator-associated pneumonia rates. Except for August 1998, ventilator-associated pneumonia rates have been below the 75th percentile since May 1998. CONCLUSION: This study illustrates the effectiveness of a multidisciplinary team approach devised to reduce and stabilize ventilator-associated pneumonia rates in a medical-surgical intensive care unit.

Adult↗
PubMed2000

Intermittent exotropia: stimulus characteristics affect tests for retinal correspondence and suppression.

BACKGROUND AND PURPOSE: Prior studies have reported various sensory responses in subjects with intermittent exotropia [X(T)]. These varying responses have been proposed due to differences in stimulus targets, backgrounds, or even a lack of control of binocular alignment. This study investigated the effects of varying target and background stimuli while controlling binocular alignment. METHODS: Eight X(T)s of the divergence excess or basic type were presented dichoptic computer generated visual stimuli while an infra red eye movement monitoring system determined horizontal eye position of each eye. Target and background were varied to assess their effect on sensory responses during latent and manifest exotropia. RESULTS: Most of our X(T)s demonstrated, while tropic, a consistent, i.e., dominant, type of retinal correspondence, i.e. a response that occurred on most tests, independent of the stimulus or background used for testing. Four subjects demonstrated harmonious anomalous retinal correspondence (HARC) while three subjects demonstrated normal retinal correspondence (NRC) with three out of four of the tests. In two out of four stimuli used for testing, one subject demonstrated NRC and another HARC. CONCLUSIONS: Complex backgrounds resulted in the largest number of suppressions, whereas blank backgrounds decreased the number of reported suppressions.

Adaptation, Ocular↗
PubMed2000

The law and ethics of the use of experimental medication in patients incapable of expressing consent: between a rock and a hard place.

In Australia, human research ethics committees approve clinical trials of drugs in accordance with federal regulations. Federal guidelines allow for the possible conduct of clinical trials in all populations. Within the State of New South Wales, persons unable to consent because of disability are subject to State legislation which, until 1998, regarded drug trials as Special Medical Treatment requiring consent of the Guardianship Tribunal. That consent could only be given if an anticipated individual benefit could be proved. As no such guarantee could be given prior to conduct of a clinical trial, it being unethical to trial an active substance against a placebo if potential individual benefit is already proven for the active substance, a conundrum resulted whereby the Tribunal could not give the required approval. Many argued that the New South Wales law resulted in some experimental medications, such as those being available to minimise tissue damage following stroke, or those being specifically developed for those with late stage dementia, not being made available to their target populations. Amendments were made to remove reference to clinical drug trials as Special Medical Treatment, and a new system established whereby such trials could proceed, including the use of a placebo, with the approval of an ethics committee and the Tribunal.

Clinical Trials as Topic↗