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Biomedical subjects

S R Bailey

Publications and source records attributed to S R Bailey.

69 records · Page 4Linked to original sources
PubMed1993

Subtle features of the hemodynamic response to amyl nitrite inhalation: new aspects of an old tool.

Although amyl nitrite inhalation (ANI) antedates all current short acting vasodilators as a clinically useful pharmacologic stressor, few clinicians are aware of the subtle hemodynamic actions of this agent. This study examined transients in left and right heart hemodynamics after ANI in seven men (ages 44 +/- 7 years) undergoing elective cardiac catheterization. High-fidelity central aortic (AoP), left ventricular (LVP), pulmonary artery (PAP), right ventricular (RVP), and right atrial (RAP) pressures were simultaneously recorded from left and right heart multisensor catheters. As expected, ANI caused an acute fall in Ao pressure (27%; p < 0.01) and reflex tachycardia (p < 0.001). Little change was noted in PAP, RVP, RAP, or LV end-diastolic pressures or the time constant of LV isovolumetric relaxation (tau). LV ejection time decreased 23 +/- 10 ms (p < 0.05) and RV ejection time did not change. Baroreflex sensitivity was similar during pressure fall and recovery (6.4 +/- 4.5 vs. 6.1 +/- 3.6 ms/mmHg), however hysteresis (p < 0.05) was noted. Aortic pressure waveforms also changed following ANI. Changes were determined to be in part a consequence of the attenuation and delay in arterial wave reflections. This study extends the understanding of the complex nature of the hemodynamic response associated with ANI.

Administration, Inhalation↗
PubMed1993

Clinical evaluation of a rapid immunoinhibition assay for creatine kinase-MB in suspected myocardial infarction.

We examined the clinical performance of a new immunoinhibition assay (INH) for the measurement of creatine kinase isoenzyme MB (CK-MB). In 196 consecutive patients admitted for exclusion of acute myocardial infarction, serial blood samples were evaluated by INH, immunoradiometric assay (IRMA), and electrophoresis (ELP). Using receiver operating characteristic curve analysis, the diagnostic performance of the INH assay was comparable to IRMA and ELP. As compared with these alternative methodologies, this newly available INH assay for CK-MB provides similar diagnostic accuracy and increased convenience at a greatly reduced cost.

Biomarkers↗
PubMed1991

A trial to assess the effectiveness of bowel preparation prior to intravenous urography.

A randomized prospective trial was undertaken to compare the relative effectiveness of two commonly used bowel preparations (senna tablets and sodium picosulphate powder) administered to patients before they underwent out-patient intravenous urography. Their 'control' films were compared with plain 'kidneys, ureters, and bladder' (KUB) radiographs of patients who had had no bowel preparation. The results show no significant difference in the degree of faecal shadowing between those receiving a bowel preparation and the unprepared patients. Nor is there any difference between the two laxatives. We conclude that the routine administration of a bowel preparation is unlikely to improve the diagnostic quality of out-patient intravenous urograms. In addition, 40% of the urogram patients found the effects of the laxatives to be unpleasant or very unpleasant.

Adolescent↗
PubMed1991

Cardiac dysfunction in patients seropositive for the human immunodeficiency virus.

To confirm the presence of cardiac dysfunction in a group of patients seropositive for the human immunodeficiency virus with either dyspnea on exertion or a reduced anaerobic threshold, 9 patients with no history of opportunistic infection underwent exercise right-sided heart catheterization. When compared with 13 control patients previously exercised in the same manner, the patients showed elevated exercise pulmonary capillary wedge pressure (14.6 +/- 3.3 mm of mercury versus 9.9 +/- 3.3 mm of mercury; P less than .005) and right atrial pressure (10.1 +/- 2.1 mm of mercury versus 4.7 +/- 3.2 mm of mercury; P less than .001) at a similar exercise oxygen consumption and cardiac index. Of the 9 patients, 8 had at least 1 catheterization value outside the 95% confidence limits for the control group and 4 patients had multiple abnormalities. Values for blood CD4 lymphocytes were 0.2 x 10(9) per liter or more for 7 of the 9. One patient underwent endomyocardial biopsy with findings consistent with a cardiomyopathy. We conclude that cardiac disease may occur at any immunologic stage of human immunodeficiency virus infection. These observations suggest an effect of this disease on the heart.

Adult↗
PubMed1991

Single lung transplantation. Alternative indications and technique.

Twenty-two patients have undergone 23 single lung transplants between March 1980 and April 1990 at the University of Texas Health Science Center at San Antonio. The actuarial survival rate is 77.27% at 12 months and 72.73% at 24 months. There have been no instances of bronchial dehiscence or stenosis, even though 13 of the patients were on a program of preoperative prednisone, every patient had high-dose perioperative methylprednisolone, and omental wraps were not used on any bronchial anastomosis. Of particular interest is the fact that three patients had primary pulmonary hypertension, three had secondary pulmonary hypertension, and 10 patients had chronic obstructive pulmonary disease, due in five cases to an alpha 1-antitrypsin deficiency. Each of these entities was previously thought to contraindicate single lung transplantation. Donor selection was based on an oxygen tension/inspired oxygen concentration ratio greater than 300, donor/recipient chest circumference within 3 inches, clear chest x-ray film, negative sputum Gram stain, and less than 6-hour estimated ischemic time. Harvest technique included donor prostaglandin E1 500 micrograms, topical slush, and pulmonoplegia with cold Euro-Collins solution. The heart and lung were separated in situ rather than the heart lung block being removed. A telescoping bronchial anastomosis was performed with 4-0 Prolene (not absorbable) sutures. We conclude that single lung transplantation has evolved into a simple operation, necessitating meticulous preoperative and postoperative care, which can be performed on a wide spectrum of critically ill patients with an acceptable mortality rate.

Adult↗
PubMed1991

Spontaneous thrombosis of iatrogenic femoral artery pseudoaneurysms: documentation with color Doppler and two-dimensional ultrasonography.

Two-dimensional ultrasonography and color Doppler were used over an 18-month period for the diagnosis and management of femoral artery pseudoaneurysms in six patients with pulsatile groin masses found after catheterization. A diagnosis of pseudoaneurysm was made when color Doppler demonstrated pulsatile systolic flow into echolucent masses. One patient underwent surgical repair of a symptomatic pseudoaneurysm after the initial Doppler study. Serial color Doppler studies were performed in five subjects, all of whom showed resolution of flow after a mean of 18 days (range 7 to 42). Despite an absence of flow, one patient underwent surgical drainage of persistent hematoma. After a mean interval of 233 days (range 84 to 552) all patients have remained free of other complications or symptoms related to the pseudoaneurysm. This experience suggests that urgent surgical repair is not required in all cases of small iatrogenic pseudoaneurysms, and that asymptomatic patients can be safely followed with serial color Doppler examinations.

Adult↗
PubMed1990

Single lung transplantation for primary pulmonary hypertension.

Single lung transplantation has become a therapeutic option for end-stage interstitial lung disease and obstructive lung disease. Our group recently extended this treatment to three patients with primary pulmonary hypertension. All patients had marked decreases in pulmonary artery pressures and pulmonary vascular resistance and increases in cardiac output following single lung transplantation. Spirometry, lung volumes, and diffusion capacity were not different in comparison to preoperative studies. Quantitative ventilation-perfusion scans revealed the majority of perfusion distributed to the transplanted lung, with ventilation approximately equally divided between the native and the transplanted lung. Despite ventilation-perfusion imbalance, there was no resting hypoxemia and there was no arterial oxygen desaturation with exercise. One patient expired on the 30th postoperative day due to cytomegalovirus infection of the lungs. In the remaining two patients, maximum exercise capacity following transplantation was near normal in one recipient and reduced in the second recipient. Of note, there was no evidence of ventilatory limitation or impaired oxygenation during exercise in these two recipients. Although an exaggerated exercise ventilatory response was present, this did not limit exercise performance. This report supports the use of single lung transplantation for the treatment of primary pulmonary hypertension.

Adult↗
PubMed1989

Phaeohyphomycotic cutaneous disease caused by Pleurophoma in a cardiac transplant patient.

A 56-y-old female cardiac transplant patient treated with cyclosporine and prednisone noted the onset of three nontender red nodules on the legs and arms after gardening. Biopsy of all lesions revealed inflammatory cells and hyphal elements in the dermis. The dematiaceous fungus cultured from biopsy tissue was a pycnidial-forming organism of the genus Pleurophoma. The lesions responded to the topical application of miconazole.

Female↗
PubMed1987

Hypertrophic cardiomyopathy: a case of refractory recurrent pulmonary edema.

An unusual case of acute pulmonary edema without associated arrhythmias in a 33-year-old woman is reported. The patient suffered recurrent pulmonary edema refractory to medication and eventual cardiac arrest. Successful emergency myectomy following cardiac arrest allowed the patient to resume an active lifestyle despite significant diastolic abnormality. During an 18-month follow-up the patient suffered one brief episode of pulmonary edema.

Adult↗
PubMed1984

Streptokinase-induced subcapsular hematoma of the liver.

Complications with thrombolytic therapy have been shown to occur no more frequently than with conventional anticoagulant therapy. Hemorrhagic complications and allergic skin reactions are the most frequently encountered adverse effects. The vast majority of the associated bleeding complications have been related to invasive procedure and monitoring techniques. The administration of systemic streptokinase was complicated in one case by development of progressive abdominal pain and hypotension necessitating an emergency exploratory laparotomy. A ruptured subcapsular hematoma of the left lobe of the liver was found and successfully repaired. This case of visceral hemorrhage complicating streptokinase therapy was not related to previous abdominal trauma or invasive procedure.

Aged↗
PubMed1975

Neonatal risk following late gestational genital herpesvirus hominis infection.

Five women developed genital herpesvirus hominis (herpes simplex virus) infection beyond 32 week's gestation. Two of the women had fresh vesicular lesions at parturition. The five infants were delivered per vaginum at term and escaped subsequent overt herpesvirus hominis infection, although a scalp lesion in one infant was dismissed as inconsequential and disappeared without virologic study. Examination of the infants two months to four years after birth failed to detect sequelae of possible subclinical infection.

Child, Preschool↗
PubMedDate not supplied

Local drug delivery: current applications.

Catheter-based treatment of coronary artery disease has historically been based on expansion or ablating vessels. Only in the last 3 years have we had devices that allow us to choose the location to apply agents directly onto or into the arterial wall. Previous trials of pharmaceutical agents in humans have failed despite animal trials showing efficacy. These agents were given in high systemic doses of drugs that may have toxic side effects with minimal effect at the site of arterial injury. Percutaneous interventions are still limited by our need to treat thrombus, alter or passivate the arterial wall, and deliver new treatments into or through the arterial wall. This review discusses the current designs of delivery catheters, ongoing trials of locally delivered agents and gene therapy. The limits of our current understanding of delivery location and efficiency as well as future investigations are also discussed.

Animals↗
PubMedDate not supplied

Biologically based validation of PC electrophysiology data collection systems utilizing the Good Automated Laboratory Practices.

Since there was a scientific need to conduct electrophysiology measurements to detect possible ocular (electroretinography, ERG), central neurotoxic (quantitative electroencephalography, qEEG), and cardiac (electrocardiography, ECG) effects in animals used in certain regulatory studies, the acquisition of suitable automated PC software systems were required. This article describes the process by which these systems were validated to ensure that they met the scientific requirements, while also addressing the principles of Good Automated Laboratory Practices (GALP). After a thorough search of existing commercial packages, a plan was developed specific for each PC-based collection system selected for evaluation. The common elements of each plan included consideration of both scientific and GALP elements, such as necessary biological response variables, raw data acquisition and identification, acceptance criteria, security, protection, storage media, data integrity, audit requirements and standard operating procedures. The authors' approach to validation for each electrophysiology system was to determine scientific needs for accuracy, precision, and detection limit of biological effects concurrent with GALP requirements. The selected software systems were employed in separate scientific GLP studies conducted in dogs, rats, and mini-pigs to demonstrate the ability to detect cholinesterase effects due to multiple infusions of physostigmine, based on parallel measurement of cholinesterase biomarkers. Since the systems were designed for human usage, certain adaptations were necessary. A critical assumption to be tested was the ability of the system's algorithms to adequately capture and assimilate the data in an accurate fashion. Concomitantly, the related GALP needs, such as data integrity, security, CD-ROM archive, and personnel training requirements were evaluated, implemented, and defined to accommodate the application and process needs. The biological approach to validation of these PC-based electrophysiology systems met the necessary scientific acceptance criteria as well as compliance requirements in order to be used in regulatory studies.

Algorithms↗
PubMedDate not supplied

An exploration of critical care nurses' and doctors' attitudes towards psychiatric patients.

The aim of this study was to uncover factors that influenced the attitudes of doctors' and nurses' towards psychiatric patients in the intensive care setting. In-depth interviews were undertaken with experienced intensive care nurses and doctors, which were subsequently analysed via an analytic induction method. The consistent themes that emerged were perceptions about the perceived paradox of treating patients who wish to die, the lack of positive reinforcement gained from caring for psychiatric patients, lack of institutional support, and a belief that present educational preparation is inadequate. The results suggest that perceptions about the purpose of intensive care units, and about the appropriateness of caring for psychiatric patients in this setting may be based on unquestioned assumptions and prejudices that are related to a deficit in knowledge and prevailing social stigma. Recommendations arising from this study are that communication channels between psychiatric units and intensive care units should be developed as a matter of priority. Furthermore, educational programs for intensive care doctors and nurses are required in order to enhance psychiatric patient care.

Attitude of Health Personnel↗