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Biomedical subjects

L Tyler

Publications and source records attributed to L Tyler.

At least 19 recordsLinked to original sources
PubMed2001

Weaning children from mechanical ventilation: a prospective randomized trial of protocol-directed versus physician-directed weaning.

OBJECTIVE: Compare outcomes between physician-directed and protocol-directed weaning from mechanical ventilation in pediatric patients. DESIGN: Prospective-randomized. SETTING: Pediatric and cardiac intensive care units in a 307-bed tertiary referral hospital for children. INTERVENTIONS: The control group (physician-directed) was weaned according to individual physician order for reduction in minute ventilation, positive end-expiratory pressure, and ordered oxygen saturation parameters for reduction in fraction of inspired oxygen (F(IO)(2)). The study group (protocol-directed) was weaned according to a predetermined algorithm developed for the purpose of this investigation. METHODS: The study enrolled 223 patients (116 physician-directed, 107 protocol-directed). All patients were monitored for hemodynamics, ventilator parameters, arterial blood gas values when available, oxygen saturation, weaning time, pre-weaning time, extubation time, and time on F(IO)(2) > or = 0.40. We also monitored the incidence of reintubation, subglottic stenosis, tracheitis, and pneumonia. The protocol-directed group had additional measurements of actual versus predicted minute volume, comparisons of respiratory rate (actual versus predicted for age), and presence of spontaneous breathing effort for 10 consecutive minutes. Data analysis was done according to intent to treat. RESULTS: There was no significant difference in 12-hour and 24-hour pediatric risk of mortality (PRISM III) scores between groups. The protocol-directed group overall had shorter total ventilation time, weaning time, pre-weaning time, time to extubation, and time on F(IO)(2) >0.40, although after stratification for respiratory diagnosis, only the difference in weaning time remained significant. There was no difference in the incidence of reintubation, new-onset tracheitis, subglottic stenosis, or pneumonia. CONCLUSIONS: Protocol-directed weaning resulted in a shorter weaning time than physician-directed weaning in these pediatric patients.

Algorithms↗
PubMed1997

Psychopathy and conduct problems in children: II. Implications for subtyping children with conduct problems.

OBJECTIVE: To test whether the presence of callous and unemotional (CU) traits designates a unique subgroup of children with conduct problems that corresponds more closely to adult conceptualizations of psychopathy. METHOD: A clinic-referred sample of 120 children between the ages of 6 and 13 years were assessed using parent and teacher ratings of CU traits, as well as parent and teacher report on a structured interview assessing oppositional defiant disorder (ODD) and conduct disorder (CD) symptoms. RESULTS: A cluster analysis of the ratings of CU traits and ODD/ CD symptoms revealed four clusters of children, two of which had high rates of ODD and CD symptoms. One of these conduct problem clusters also exhibited high levels of CU traits (n = 11). These children had a greater number and variety of conduct problems, a stronger history of police contacts, and a stronger parental history of antisocial personality disorder, despite being of higher intelligence than other children with significant conduct problems (n = 29). CONCLUSION: The presence of CU traits with significant conduct problems seems to designate a unique subgroup of antisocial children who show a very severe pattern of antisocial behavior and who correspond more closely to adult conceptualizations of psychopathy.

Adolescent↗
PubMed1996

Bringing reality to the job hunt process. Interview by Barbara J. Linney.

A substantial percentage of the positions that open in medical management are filled through the use of recruitment firms. This is especially true of more senior positions, but it applies across the full spectrum of openings. If the working arrangement between the recruitment firm and the potential candidate is to be effective, certain key ingredients are necessary. The author interviewed a selection of principals of recruitment firms that operate extensively or exclusively in the medical management sector of executive recruitment. What she discovered about their "wish lists" for candidates' characteristics and levels of job hunting sophistication are summarized in the following statements.

Career Choice↗
PubMed1991

Steps in the implementation of a micro-computer approach to the management of animal disease information.

The stages in the design, procurement and implementation of a micro-computer-based animal health information system are described. The scenario presented is that of a national Director of Veterinary Services taking his first steps in the computerisation of an epidemiology unit, but sub-national and international issues are also discussed. The administrative and management aspects are considered and the need to incorporate computers into a carefully designed and appropriate information system is emphasised. The principles of the specification of initial systems and their subsequent development are described; suggestions are made for the procurement and continuing support of both hardware and software.

Animal Diseases↗
PubMed1991

Panel sees high demand for diverse CFO skills.

A more sophisticated healthcare industry, challenged by competition and payer demands, also looks for sophistication when filling its senior financial positions. Individuals with experience in managed care contract negotiations, knowledge of hospital-physician ventures, and superior planning and treasury management skills are increasingly sought by hospitals. Some organizations also may single out chief financial officers able to assume broader administrative duties, including chief executive officer positions. These are among the observations of a panel convened by HFMA to discuss recent trends in healthcare executive recruiting. Highlights of the session, moderated by HFMA President Richard L. Clarke, FHFMA, follow.

Employment↗
PubMed1990

Watch out for "red flags" on a job interview.

Job candidates are often extremely naive when interviewing for a new position. They have been told to "sell themselves," and that's what they set out to do. Unfortunately, some jobs are not worth the effort. Ironically, when the job sours, candidates often look back and say, "The warning signs were there; I just ignored them." By watching out for "red flags" during the interview process, candidates may be able to avoid unpleasant surprises.

Administrative Personnel↗
PubMed1989

Interaction of amiodarone and desethylamiodarone with the cardiac muscarinic receptor in vitro.

We studied the interaction of amiodarone hydrochloride (Cordarone) and its major metabolite desethylamiodarone with the muscarinic receptor in purified canine cardiac sarcolemmal vesicles by measuring equilibrium binding of the muscarinic antagonist [3H]quinuclidinyl benzilate (QNB) and carbachol displacement of [3H]-QNB. At a [3H]-QNB concentration of 0.02 nM, equilibrium binding was inhibited by amiodarone and desethylamiodarone with an IC50 of 6.86 x 10(-6) M and 2.25 x 10(-6) M, respectively. The presence of increasing concentrations of [3H]-QNB in the incubation medium was able to reverse the inhibition seen with 1 x 10(-6) M amiodarone. Scatchard analysis of [3H]-QNB saturation isotherms (37 degrees C, pH 7.4) in the presence of 1 x 10(-6) M amiodarone showed an apparent increase in equilibrium dissociation constant (Kd) over control from 0.045 +/- 0.002 nM to 0.084 +/- 0.001 nM while maximal binding capacity (Bmax) was unaffected: 10.8 +/- 1.14 and 10.5 +/- 1.48 pmol/mg (means +/- S.E.M., n = 3), respectively. The inhibitory effect of amiodarone on equilibrium binding was highly dependent on the drug:membrane phospholipid mole ratio with effects beginning at a ratio of less than 0.1:1. Hill plot analysis was consistent with the interaction of [3H]-QNB at a single site in the presence or absence of amiodarone. Amiodarone (3 x 10(-6) M) decreased the pseudo-first order forward rate constant of [3H]-QNB (0.02 nM) with the muscarinic receptor (kobs = 4.05 +/- 0.61 x 10(-4)/s under control conditions and 2.36 +/- 0.15 x 10(-4)/s in the presence of amiodarone).(ABSTRACT TRUNCATED AT 250 WORDS)

Amiodarone↗
PubMed1989

Fc receptors on the surface of Toxoplasma gondii trophozoites: a confounding factor in testing for anti-Toxoplasma antibodies by indirect immunofluorescence.

Negative sera often produce false-positive polar patterns of fluorescence in indirect immunofluorescence tests for serum anti-Toxoplasma gondii antibodies, representing a confounding factor in the diagnosis of toxoplasmosis. In this work, we studied whether T. gondii trophozoites, the antigenic material used in the immunofluorescence tests, expressed surface Fc receptors that could cause the binding of normal immunoglobulins, thus producing false-positive results. We report here that T. gondii trophozoites indeed have Fc receptors on their surface. This was shown by the direct binding of purified human Fc to the parasite, evidenced by the subsequent binding of fluorescein-labeled Fab specific for human Fc. In addition, pretreatment of the parasite with excess purified Fc to saturate the surface Fc-binding sites abrogated the formation of polar fluorescence. The trophozoites appeared to express Fc receptors with different degrees of affinity for the specific ligand, since a diffuse fluorescence pattern was observed following incubation with 1 mg of Fc per ml (10 micrograms per well), whereas with 0.2 mg (0.2 micrograms per well), a majority of parasites showed polar fluorescence. This observation suggests that the Fc receptors accumulated at the polar cap are those with higher affinity. The present findings raise intriguing questions regarding the possible biological role(s) of the Fc receptors on T. gondii but, more immediately, indicated that pretreatment of the antigenic material with Fc, a commercially available reagent, constitutes a practical, simple way to avoid false-positive immunofluorescence test results due to the binding of nonspecific immunoglobulin to the parasite.

Animals↗
PubMed1984

Effects of myocardial ischemia on cardiac contractility and ion transport in working and Langendorff rabbit heart.

In order to define the ischemic myocardial injury in terms of the possible alteration of cardiac membrane properties, Rb+ uptake and 3H-ouabain binding to cardiac tissue were compared in normal and ischemic rabbit hearts. In isolated Langendorff or working rabbit hearts, a global ischemia was produced by reducing the coronary flow of oxygenated Krebs-Henseleit solution for various time intervals. The normal or ischemic tissues were subjected to study the uptake of Rb+ and ouabain bindings. In Langendorff hearts there was little or no significant difference in active uptake of Rb+ in normal and ischemic heart. However, in the working heart, there was a significant decrease in Rb+ uptake in the ischemic hearts. As the case of Rb+ uptake ouabain binding was significantly reduced in ischemic working heart in comparison to working normal heart preparations at high concentrations of ouabain, the present study suggests the importance of cardiac contractility for the cellular energy metabolism and membrane transport activity.

Animals↗
PubMed1982

Recent trends in neonatal mortality: the Canadian experience.

In Canada between 1958 and 1977 the neonatal mortality dropped by more than 50%. the decline was most prominent from 1963 and was almost entirely due to an improvement in neonatal birthweight-specific mortality, which suggests an improvement in perinatal medical care. The timing and pattern of the decline are similar to those reported for the United States. There was a transient increase in the incidence of low and very low birthweight in both countries in the late 1960s. The cause of this increase remains unexplained.

Adult↗
PubMed1978

Enzootic bovine leucosis.

Enzootic bovine leucosis is associated with infection by bovine leucosis virus. The incubation period is measured in years and a minority of infected animals develop clinical signs. The disease is widespread in Europe and elsewhere and can cause significant economic loss. The epidemiology is incompletely understood and findings from one cattle production system may not be directly applicable to another. Major control programmes exist in Denmark and West Germany and control schemes are being developed elsewhere. Eradication of enzootic bovine leucosis has been established as a goal in the EEC and research is revealing the ways in which this goal may be attained. To be effective, control and epidemiological monitoring must be interactive. Recently introduced serological tests, of improved sensitivity, provide a valuable tool.

Animals↗
PubMed1975

Defective heparan sulfate metabolism in the Sanfilippo syndrome and assay of this defect in the assessment of the mucopolysaccharidoses patient.

The Sanifilippo syndrome is an inherited dementia caused by defective degradation of heparan sulfate. In the course of its catabolism the heparan sulfate polymer must be desulfated. Heparan sulfate sulfatase activity was demonstrated in homogenates of normal tissues and cultured skin fibroblasts, and in normal urine. This activity was found to be grossly depressed or absent in necropsy specimens of liver and spleen from two Sanfilippo patients. The heparan sulfate sulfatase activity was not demonstrable in urine from eleven, or cultured fibroblasts from four Sanfilippo patients. Activities of alpha-N-acetyl-glucosaminidase, the site of the metabolic defect in the Sanfilippo B variant were either normal or slightly elevated in the Sanfilippo tissues and cultured fibroblasts whereas the mean level in the urine of our Sanfilippo patients was about one-third of that encountered in control urines.

Acetylglucosaminidase↗