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Biomedical subjects

T Buckley

Publications and source records attributed to T Buckley.

35 records · Page 2Linked to original sources
PubMed1993

Verification of the Acute Physiology and Chronic Health Evaluation scoring system in a Hong Kong intensive care unit.

OBJECTIVES: To validate the Acute Physiology and Chronic Health Evaluation (APACHE II) severity of illness scoring system in Chinese patients in a multidisciplinary intensive care unit (ICU) in Hong Kong. To audit the service and utilization of an ICU with a low ICU to hospital bed ratio. DESIGN: Prospective data collection and review. SETTING: A 12-bed multidisciplinary ICU within a 1,430-bed tertiary care university hospital. PATIENTS: Data from 1,573 of 1,814 consecutive patients admitted to the ICU from May 1988 to November 1990 were studied. The patients were all Chinese. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The patients' clinical details and APACHE II scores were recorded on day 2 of admission and reviewed at hospital discharge or after death. The APACHE II scores, risk of death values, age, and length of ICU stay between survivors and nonsurvivors were compared by two-sample t-tests. Relationships between mortality and APACHE II score, risk of death, and results from previous studies were investigated using the Pearson product-moment coefficient and regression analysis. Predictive capacity of risk of death was assessed by receiver operating characteristic curve analysis. The hospital mortality rate for study patients was 36%. Survivors were younger, had shorter ICU stays, lower APACHE scores, and lower risk of death values than nonsurvivors (p < .001). There was close correlation (r2 = .81, .77, and .76 for all patients, operative group, nonoperative group, respectively) between APACHE II scores and predicted risk of death values. Risk of death was an accurate group predictor of death in all patients and in separate operative and nonoperative groups. Areas under the receiver operating characteristic curves were 0.89 (all patients), 0.85 (operative), and 0.88 (nonoperative). Neither the Apache II scores nor risk of death scores were sufficiently accurate to predict outcome of individual patients. There was close concordance between observed and predicted mortality of patient groups. Mortality ratio was 0.97 (all patients), 0.89 (operative group), and 1.02 (nonoperative group). Chronological age, per se, was not a good predictor of mortality. The audit of the ICU service showed a short length (4.2 days) of ICU stay and high bed occupancy (80%). Subgroups of low-risk, postoperative patients with good outcomes and poor-risk patients admitted after cardiopulmonary arrest with a high mortality rate were identified. CONCLUSIONS: The APACHE II scoring system was an accurate predictor of group outcome in a Chinese population, making it suitable for comparisons between countries. Application of the APACHE II scoring system in a clinical audit facilitates critical appraisal of an ICU service. Problems identified by the study were a shortage of ICU beds and delayed referrals of patients.

Adult↗
PubMed1991

Bronchoalveolar lavage findings in horses with exercise intolerance.

Significant differences were detected by bronchoalveolar lavage (BAL) between horses racing successfully and those showing exercise intolerance. Neutrophil percentage, haemosiderophage percentage and total bacterial numbers were significantly elevated in horses with exercise intolerance. BAL provided a more accurate indication of the incidence and extent of exercise induced pulmonary haemorrhage (EIPH) than visual inspection.

Animals↗
PubMed1990

Pharmacokinetics of propofol in women undergoing elective caesarean section.

We have compared the pharmacokinetics of a bolus induction dose of propofol 2 mg kg-1 in 10 Chinese women undergoing elective Caesarean section with those in six non-pregnant Chinese women having laparoscopic sterilization. Blood propofol concentrations were measured using high pressure liquid chromatography with fluorimetric detection. Pharmacokinetic data were analysed by a model independent method based on statistical moment theory. Data from the laparoscopy group also underwent compartmental analysis, which produced similar kinetic results. Non-compartmental analysis estimated that the women undergoing Caesarean section had a similar elimination half-life (mean 81.27 (SD 18.87) min) and apparent volume of distribution at steady state (2.66 (0.63) litre kg-1) as non-obstetric patients (99.45 (29.40) min and 3.36 (1.87) litre kg-1). Clearance was more rapid in the Caesarean section group (39.32 (8.07) ml min-1 kg-1 vs 29.40 (8.72) ml min-1 kg-1) (P less than 0.05). The increased total body clearance may result from blood loss and delivery of the fetus and placenta at operation, although an increase in extrahepatic clearance is also possible.

Adult↗
PubMed1988

Shallow versus deep endotracheal suctioning in young rabbits: pathologic effects on the tracheobronchial wall.

The traditional technique for endotracheal suctioning of intubated neonates consists of inserting a catheter until resistance is met, withdrawing slightly, and applying suction. The extent of tissue damage caused by the traditional (deep) technique v that caused by an alternative shallow technique was studied with an animal model. Six 3-week-old rabbits were anesthetized, intubated, and suctioned every 15 minutes for six hours by neonatal intensive care unit nurses who were unaware of the study purpose. Three rabbits were suctioned by means of the deep technique, whereas the other three received shallow suctioning achieved by inserting the catheter no further than a premeasured distance. Light microscopy showed significantly increased necrosis and inflammation following deep suctioning. Electron microscopy revealed greater loss of cilia and increased mucus with the deep technique. To confirm our initial assumption that the deep technique is still used extensively by neonatal intensive care units throughout the country, a mail survey was conducted. Of the 405 (43%) neonatal intensive care unit physicians who responded, 82% reported frequent or exclusive use of the deep technique for routine suctioning. In this study, the fact that deep suctioning results in significantly more tracheobronchial pathology than does a shallow, premeasured technique is shown. It is recommended that nurseries change their current practice and adopt the shallow technique for routine suctioning of intubated neonates.

Animals↗
PubMed1986

Lethal potency and tissue distribution of 125I-labelled toxic peptides from the blue-green alga Microcystis aeruginosa.

Toxic heptapeptides from a water bloom of the cyanobacterium Microcystis aeruginosa were purified by HPLC. The unoxidised fraction was iodinated with 125I plus 127I by the lactoperoxidase/H2O2 method, further purified by HPLC, and the non-iodinated and three iodinated fractions administered i.p. to male mice. All iodinated fractions were toxic, with symptoms and pathological lesions of the liver identical with those caused by non-iodinated peptide. Radioactivity was concentrated in the liver of mice at death.

Animals↗
PubMed1986

Biological half-life, organ distribution and excretion of 125-I-labelled toxic peptide from the blue-green alga Microcystis aeruginosa.

M. aeruginosa is a bloom-forming cyanobacterium which is common in fresh-water lakes. It contains a potent hepatotoxin which when purified has been shown to be a heptapeptide of molecular weight 1019. The toxin was iodinated with 125I using the lactoperoxidase method, the labelled toxin administered intravenously to adult female rats and the half-life and organ distribution measured. The blood half-life after redistribution into extracellular pools was 42 min. The liver and kidneys showed accumulation of 21.7 +/- 1.1 and 5.6 +/- 0.2% of the dose respectively after 30 min. Little accumulation was observed in other organs and tissues. Small-intestinal contents and urine contained 9.4 +/- 6.1 and 2.9 +/- 1.2% of the dose respectively after 120 min. It was concluded that the liver is the main target organ for both accumulation and excretion of the toxin.

Animals↗
PubMed1978

A method for the study of internal spaces in hard tissue matrices by SEM, with special reference to dentine.

Infiltration of a porous hard tissue with methyl methacrylate, followed by dissolution of the tissue provides a three-dimensional methacrylate cast of spaces within the tissue. Examination of such a cast by scanning electron microscopy provides information on the nature and extent of the pore system to a degree that cannot readily be visualized by the direct examination of fractured surfaces. The findings described concern human dentine but the technique may have a wider application in studies on the internal structure of other hard tissues.

Dental Enamel Permeability↗
PubMedDate not supplied

The relationship of self-injurious behavior and aggression to social skills in persons with severe and profound learning disability.

In this study, we investigated differences in social skills among four groups of individuals with severe and profound learning disabilities. The comparison groups were composed of individuals engaging in self-injurious behavior, aggression, both behaviors, or neither of the behaviors. We measured social skills using the Matson Evaluation of Social Skills for Individuals with Severe Retardation, a standardized assessment of social skills in persons with severe or profound learning disability. The results indicated that individuals displaying maladaptive behaviors exhibited a restricted range of social behaviors compared to controls. Also, group membership based on self-injury and aggression was predicted based on profiles of scores on the Matson Evaluation of Social Skills for Individuals with Severe Retardation. These findings are consistent with reports in other studies that note social skills deficits in aggressive and self-injurious persons with learning disabilities. However, in this case a standardized assessment of these deficits was possible and specific skills problems were identified. Implications of the findings for identification and treatment of self-injury and aggression are discussed.

Adolescent↗
PubMedDate not supplied

Perioperative care in left ventricular volume reduction.

BACKGROUND: While the operative technique of left ventricular volume reduction (LVVR) is rapidly becoming standardized, the optimal perioperative management strategy is yet to be determined. We present our experience with the care of patients undergoing LVVR. METHODS: LVVR was performed in 21 patients (mean age = 65.5 years) with congestive heart failure. Our management strategy was initially based on afterload reduction with sodium nitroprusside, but was later modified to include routine preoperative intra-aortic balloon support, normothermic cardiopulmonary bypass, antegrade intermittent warm blood cardioplegia, and postoperative support with phosphodiesterase-III inhibitors. Hemodynamic manipulations are aimed to attain systemic vascular resistance between 600 and 800 dyne/sec per cm(-5) and the lowest mean blood pressure that is able to maintain satisfactory systemic perfusion. Postoperatively, aggressive antifailure medical therapy with a high dose of angiotensin converting enzyme inhibitors, nitrates, and diuretics was initiated early and maintained indefinitely. RESULTS: Using this approach, postoperative progress was characterized by hemodynamic stability. IABP support was used for 59.6+/-9 hours following surgery, and inotropic support for 103+/-12 hours. In our series there were four (19%) in-hospital deaths, two of which were related to heart failure. CONCLUSION: The described approach is associated with an acceptable early outcome. However, further advances in myocardial protection methods and pharmacological and mechanical support techniques are necessary for a wider adoption of this procedure.

Aged↗
PubMedDate not supplied

Population-based exposure measurements in Arizona: a phase I field study in support of the National Human Exposure Assessment Survey.

The objective of this proposed Phase I field study is to determine the distributions of total human exposures to multimedia pollutants in the classes of metals, pesticides, and volatile organic compounds (VOCs). This will be achieved by studying a proportion-based sample of the total population in Arizona with a nested design for the different stages of sampling. Specific objectives are: (1) to document the occurrence, distribution, and determinants of total exposures in the general population; (2) to characterize the 90th percentiles of total exposures to each pollutant; (3) to monitor geographic and temporal trends of the multimedia exposures; (4) to evaluate the different media, personal, time-activity, and geographical factors that contribute to current total exposure; (5) to evaluate biomarkers in blood and urine for the target pollutants; (6) to perform evaluations of relationships between exposure reports, environmental measurements, and biomarkers of the target pollutants; (7) to predict total exposures; and (8) to assess total exposures in minority and disadvantaged subsets of the population. The latter is particularly feasible in Arizona due to the large proportions of such population subgroups. The proportionate-based population sampling of households within blocks will occur in Stage 1; the target is 1,200 such households. They will be interviewed utilizing National Human Exposure Assessment Survey (NHEXAS) questionnaires. In Stage 2, additional questionnaires will be completed; environmental sampling will take place in 450-900 households representatively selected from the respondents. Environmental sampling will include: metals in dust, soil, outside air, and some tap water; pesticides in dust, soil, and some tap water; total VOCs in air. In Stage 3, a subset of representative households will be reevaluated for metals, pesticides, and VOCs using methods with greater resolution and reliability; subjects in these households will be asked to complete questionnaires and provide biological samples. Follow-up temporal evaluations will be performed in a randomly selected subset of homes evaluated during this stage.

Arizona↗