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Biomedical subjects

R Shipley

Publications and source records attributed to R Shipley.

8 recordsLinked to original sources
PubMed1998

An automated injection system (with patient selection) for SPECT imaging in seizure localization.

PURPOSE: Ictal single-photon-emission computed tomography (SPECT) provides lateralization but has technical limitations: (a) a "truly ictal" injection must be shortly after seizure onset; (b) therefore, a seizure of brief duration may be missed; (c) more than one patient may need testing at any given time; (d) a trained health professional must stay next to each patient to inject; and (e) because the radionuclide is placed in the syringe in advance of the injection, decay of the radioactive element could result in less than optimal uptake, if the same volume of material were to be used regardless of the time after ligand preparation. METHODS: We developed an automated method of ligand injection that shortens time and increases efficiency of ictal SPECT ligand injection. By using an experimental setup, we compared manual injection times with times using an automated injection system. We determined relative costs and efficiency in work hours for the manual and automated methods. RESULTS: Injection times were 8-14 s with automated versus 19-26 s with manual injection. Readjusting volume for "ligand" decay was simple and accurate with the automated system. Injection times for clinical SPECT studies in three patients were 13, 13, and 12 s, respectively. The price of one pump equals 120 work hours of a nurse or 24 ictal injection attempts. Much of the nurse's time is "wasted" because no seizure occurs. CONCLUSIONS: The method can be more efficient of staff, shorten injection time, and facilitate obtaining "truly ictal" injections. It allows more cost-effective use of personnel.

Algorithms↗
PubMed1996

Refractory ceramic fiber exposure and pleural plaques.

Refractory ceramic fibers (RCF) are manmade vitreous fibers (MMVF) manufactured for high-temperature applications. Between 1987 and 1992, a retrospective cohort and nested case-control study evaluated chest radiographs from 652 workers involved in the manufacture of these fibers for plausibility of a causal relationship between exposure to RCF and chest-radiographic changes. The exposure-response relationship was modeled with three variables: years since first fiber production job, years in fiber production, and cumulative fiber exposure to date of study X-ray. The case-control study used a comprehensive characterization of possible asbestos exposure to investigate asbestos as the potential causative agent of chest-radiographic changes. Chest radiographs of 20 workers (3.1%) demonstrated 19 pleural plaques and one diffuse pleural thickening. Nine of 72 workers (12.5%) with more than 20 yr since their first fiber-production job had plaques (odds ratio [OR] = 9.5; 95% confidence interval [CI] = 1.9 to 48.2). Five of 19 workers with more than 20 yr in fiber-production work (26.3%) had plaques (OR = 22.3; 95% CI = 3.6 to 137.0). Similarly, adjusted ORs demonstrated a progressive relationship between cumulative fiber-months per milliliter (fiber-mo/ml) exposure and plaques. The case-control study confirmed that asbestos exposure did not account for the observed association between fiber exposure and plaques. A validity review of historical films demonstrated biologic plausibility for the association, since sufficient latency existed from the time of first RCF exposure to the development of plaques. There was no significant increase in parenchymal changes consistent with interstitial fibrosis.

Asbestosis↗
PubMed1993

Clinical trials using ascorbic acid aerosol to aid smoking cessation.

Sensory aspects of cigarette smoke are important for providing smoking satisfaction. In previous studies, we have found that substitution of the sensory cues of smoking with a citric acid aerosol significantly reduces craving for cigarettes and enhances smoking reduction and cessation with people trying to quit smoking cigarettes. In the current study, we conducted two clinical smoking cessation trials using an ascorbic acid aerosol as a sensory substitute. The cigarette substitute consisted of a cigarette-sized tube which delivered a fine aerosol of ascorbic acid (approx. 1 mg/puff, up to a maximum of 300 mg/day). Study 1 examined the overall effectiveness of the ascorbic acid smoking substitute device. One group of subjects which used the device and received clinical counseling was compared with another group which received only clinical counseling. The group using the device showed significantly greater abstinence rates at 3 weeks post-cessation. After the subjects stopped using the device, no difference in abstinence was detected. Study 2 was conducted to focus specifically on the role of tracheobronchial sensations in relieving craving for cigarettes. Two closely matched ascorbic acid delivery systems were compared. One device delivered fine particles of ascorbic acid that were targeted to reach the trachea, while the other delivered coarser particles of ascorbic acid that were not expected to reach the trachea or lower airways. An initial enhancement in smoking reduction was found for subjects using the fine particle device relative to those using the coarse particle device. However, by the end of treatment (5 weeks) both groups showed similar degrees of smoking reduction. For those who were abstinent from smoking at the end of treatment, craving for cigarettes and negative mood were both significantly lower for those using the fine particle device. Also, hunger for food was significantly lower in the fine particle device group. These results suggest that ascorbic acid delivered from a cigarette substitute may be effective in reducing smoking and promoting smoking abstinence.

Adult↗
PubMed1993

Increased Pneumocystis carinii recovery from the upper lobes in Pneumocystis pneumonia. The effect of aerosol pentamidine prophylaxis.

STUDY OBJECTIVE: To determine the relative distribution of Pneumocystis carinii in the lungs of patients with P carinii pneumonia and to see the effect of aerosol pentamidine prophylaxis on this distribution. DESIGN: A prospective study of all human immunodeficiency virus-infected patients with pulmonary symptoms over a nine-month period. Patients were followed up for at least six weeks after bronchoscopy. SETTING: Inpatient and outpatient service at one referral center. PATIENTS: Human immunodeficiency virus-infected patients with pulmonary symptoms were referred for evaluation. Those patients subsequently found to have P carinii pneumonia were studied. INTERVENTION: Bronchoalveolar lavage was performed in the middle lobe (or lingula) and the apical segment of the same lung. MEASUREMENTS AND RESULTS: The aspirated fluids were kept separate and modified Wright-Giemsa-stained cytocentrifuge-prepared slides were made from each area, and the number of P carinii clusters per 500 nucleated cells was counted. Fifty patients were studied: 27 receiving pentamidine prophylaxis and 23 receiving no aerosol therapy. There was no significant difference in the amount of fluid retrieved by lavage from the middle or upper lobe for either group. Both groups had significantly lower numbers of P carinii clusters per 500 cells in the middle lobe (receiving pentamidine: 10 +/- 15.8 [SD]; not receiving pentamidine: 15 +/- 12.3) than in the upper lobe (receiving pentamidine: 22 +/- 19.8; not receiving pentamidine: 24 +/- 21.5; p < 0.02). In six patients, there were no P carinii organisms seen in the middle lobe lavage specimen. CONCLUSION: Pneumocystis carinii has a preference for the upper lobes which may be apparent even in patients not receiving aerosol pentamidine. In addition, yield for P carinii may be increased by performing lavage in the apical segment.

AIDS-Related Opportunistic Infections↗
PubMed1987

Predictive value of gallium scan, angiotensin-converting enzyme level, and bronchoalveolar lavage in two-year follow-up of pulmonary sarcoidosis.

Evaluation of patients with pulmonary sarcoidosis with serum angiotensin-converting enzyme (ACE), gallium scan, and bronchoalveolar lavage (BAL) has proved useful in demonstrating active disease, especially in the lungs. Long-term prognosis based on the results of pretreatment ACE, gallium scan, and BAL has not been previously clarified. We studied 44 patients with initially symptomatic pulmonary sarcoidosis who were begun on steroid therapy after initial evaluation. At 2 years, 21 of 44 (48%) patients still had worsening disease. Of 31 patients who had positive gallium scan pretreatment, 21 (68%) still had worsening disease at 2 years. None of the 13 patients with a negative gallium scan had worsening disease at 2 years (Chi square = 14.2, P less than 0.01). Similar analysis of the pretreatment serum ACE level, percentage of lymphocytes in the BAL fluid, and ratio of T-helper/inducer to T-suppressor/cytotoxic (T4/T8) in the BAL fluid also had some predictive value for worsening disease at 2 years; however, these tests were less sensitive than the gallium scan. In patients with pulmonary sarcoidosis, the finding of a negative gallium scan suggests a small likelihood that disease activity will worsen after 2 years.

Adult↗