大蒜素延迟预处理对兔血流动力学的影响

目的：探讨大蒜素对兔心肌梗死模型血流动力学指标的延迟保护作用。方法：采用血流动力学作为心肌梗死损伤指标,观察大蒜素（1、0.5mg/kg）预处理对24h后实验性兔心肌梗死损伤的保护作用。结果：大蒜素（0.5、1mg/kg体重）预处理使复灌末LVEDP较缺血再灌损伤组分别降低32.34%及56.56%（P〈0.01或P〈0.05）;LVPSP分别提高61.58%及94.33%（P〈0.05）;＋dp/dt分别增加19.94%及49.84%（P〈0.05）,-dp/dt分别增加24.17%及51.33%（P〈0.05或P〈0.01）。但对动物HR、CF无明显改变。结论：大蒜素在实验性兔心肌梗死模型能够模拟缺血预处理延迟保护作用,具有药物预处理的潜在价值。     

Determinants of respiratory system input impedance and bronchodilator response in healthy Finnish preschool children

In order to study the determinants of respiratory system impedance and bronchodilator response in preschool children, a sample (n = 109) of healthy children (age 2.1-7.0 years) attending kindergarten was measured by using the impulse oscillometry. Their selection was based on a standardized questionnaire, negative skin prick test results and clinical examination, and sufficient cooperation. Triple measurements of respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, 15 and 20 Hz, total respiratory impedance (Zrs), the resonance frequency (Fr) and the frequency dependence of resistance (dRrs/df) were performed, to determine individual mean values. Measurements were repeated after inhalation of 300 microg salbutamol (n = 89) or placebo (n = 19). At the baseline, Zrs and Rrs5-20 showed negative, and Xrs5-20, Fr and dRrs/df positive correlations with age, height and weight. However, logarithmic transformed height was the best independent variable for the regression equations of all the oscillometric variables. After inhalation of placebo, none of the oscillometric variables changed significantly. In the salbutamol group, the mean (SD) change in Rrs5 was -0.187 (0.124) kPa l(-1) s(-1) and -19.2 (10.2)%, corresponding to a lower reference limit of -36.9%. Both the within-test and between-test repeatabilities for the measurement of respiratory resistance were acceptable, for Rrs5 the coefficients of variation being 6.2 and 6.1%, respectively. As the overall success rate in our sample was high (89%), the forced oscillation technique seems to be a useful method in assessing respiratory function and bronchial lability in preschool children.     

Adapting to psychiatric disability and needs for home- and community-based care

The objective of the study was to describe adaptation strategies and use of formal and informal support by individuals with psychiatric disabilities, to delineate remaining needs, and to determine how home- and community-based services might address those needs. Using in-depth interviews and structured questionnaires, we examined functional status, adaptation, and needs for home- and community-based care among 33 severely mentally ill members of a large health maintenance organization. Despite success in community living, participants had significant functional deficits (physical and emotional), relied heavily on only one or two key informal caregivers, and often needed significant support from mental health professionals. Limited numbers of caregivers and social isolation placed participants at risk of negative outcomes if informal support resources were to be lost. Home- and community-based care interventions that attempt to increase informal support networks and provide instrumental help (cooking, cleaning, transport) on short notice during flare-ups could augment existing (but limited) informal caregiving, help severely mentally ill individuals remain independent, and reduce the likelihood that loss of an informal caregiver would result in unwanted outcomes.     

Distribution of lymphocyte surface antigens in healthy neonates

Using flow cytometric analysis we investigated the distribution of major lymphocyte surface antigens in newborn infants. A total of 221 newborns entered the study, of whom 53 fullfilled our criteria of healthy mature neonates. Percentages of immunofluorescent-positive cells were as follows (median and range from 25th to 75th percentiles given): for CD1 3.8%; 2.3%–5.8%. CD2 60.9%; 52.4%–66.8%. CD3 57.5%; 50.5%–63.3%. TcRaß 57.7%; 48.1%–60.0%. CD4 36.3%; 28.0%–42.6%. CD8 23.0%; 20.0%–27.4%. CD11a 56.3%; 46.3%–68.5%. CD19 12.1%; 8.6%–14.8%. CD20 10.9%; 8.4%–12.9%. CD25 2.6%; 2.1%–4.5%. CDw52 61.0%; 51.2%–76.1%. CD71 5.2%; 3.1%–9.3%. While the ranges for the percentage of immunofluorescent-positive cells were rather small, there was a wide variation in the absolute numbers of marker immunofluorescent-positive cells.     

Bayesian statistics in medical research: an intuitive alternative to conventional data analysis

Statistical analysis of both experimental and observational data is central to medical research. Unfortunately, the process of conventional statistical analysis is poorly understood by many medical scientists. This is due, in part, to the counter-intuitive nature of the basic tools of traditional (frequency-based) statistical inference. For example, the proper definition of a conventional 95% confidence interval is quite confusing. It is based upon the imaginary results of a series of hypothetical repetitions of the data generation process and subsequent analysis. Not surprisingly, this formal definition is often ignored and a 95% confidence interval is widely taken to represent a range of values that is associated with a 95% probability of containing the true value of the parameter being estimated. Working within the traditional framework of frequency-based statistics, this interpretation is fundamentally incorrect. It is perfectly valid, however, if one works within the framework of Bayesian statistics and assumes a 'prior distribution' that is uniform on the scale of the main outcome variable. This reflects a limited equivalence between conventional and Bayesian statistics that can be used to facilitate a simple Bayesian interpretation based on the results of a standard analysis. Such inferences provide direct and understandable answers to many important types of question in medical research. For example, they can be used to assist decision making based upon studies with unavoidably low statistical power, where non-significant results are all too often, and wrongly, interpreted as implying 'no effect'. They can also be used to overcome the confusion that can result when statistically significant effects are too small to be clinically relevant. This paper describes the theoretical basis of the Bayesian-based approach and illustrates its application with a practical example that investigates the prevalence of major cardiac defects in a cohort of children born using the assisted reproduction technique known as ICSI (intracytoplasmic sperm injection).     

The first object oriented monitor for intravenous anesthesia

Objective.To describe the design and implementation ofINFUSION TOOLBOX, a software tool to control and monitormultiple intravenous drug infusions simultaneously using pharmacokinetic andpharmacodynamic principles. Methods.INFUSION TOOLBOX has been designedto present a graphical interface. Object Oriented design was used and thesoftware was implemented using Smalltalk, to run on a PC. Basic tools areavailable to manage patient, drugs, pumps and reports. These tools are thePatientPanel, the DrugPanel, the PumpPaneland theHistoryPanel. The screen is built dynamically. The panels may becollapsed or closed to avoid a crowded display. We also built control panelssuch as the Target ControlPanelwhich calculates the best infusionsequence to bring the drug concentration in the plasma compartment to a presetvalue. Before drug delivery, the user enters the patients data, selectsa drug, enters its dilution factor and chooses a pharmacokinetic model. Thecalculated plasma concentration is continually displayed and updated. Theanesthetist may ask for the history of the delivery to obtain a graphic reportor to add events to the logbook. A panel targeting the effect is used when apharmacodynamic model is known. Data files for drugs, pumps and surgery areupgradable. Discussion.By creating a resizeable ControlPanelwe enable the anesthetist to display the information he wishes, when hewishes it. The available panels are diverse enough to meet the anesthetistneeds; they may be adapted to the drug used, pumps used and surgery. It is theanesthetist who builds dynamically its different control screens.Conclusion.By adopting an evolutionary solution model we have achievedconsiderable success in building our drug delivery monitor. In addition wehave gained valuable insight into the anesthesia information domain that willallow us to further enhance and expand the system.     

A TLC screening program for 170 commonly used pesticides using the corrected Rf value (R f c value)

Summary This article reports TLC data (corrected R_f values; R _f ^c values) of 170 commonly used pesticides which are regularly encountered in toxicological analysis. Silica gel was used as the stationary phase and three binary systems were chosen as solvents.     

Reference ranges of echocardiographic measurements in the Dutch population

Reference ranges for echocardiographic measurements were determinedin 609 healthy Dutch subjects, using height, weight, age, sex,RR-interval and blood pressure (in adults only) as determinants.Endsystolic as well as end-diastolic measurements of the aorticroot as well as left ventricular inner diameter, posterior andseptal thickness were taken, as was the left atrial end-systolicdiameter. Multiple linear regression was performed of the form: =A.(age)^B.(height)^C.(weight)^D.(RR-interval)^E.(sex)^F. The residuals were calculated in order to determine the percentilelimits by means of linear interpolation. Sex and weight weresignificant determinants in all the echocardiographic parametersstudied. The results were presented twofold, with a simple versionfor males and females separately, using only weight as a determinantand allowing graphical presentation, and secondly a complexversion taking into account all determinants, which can onlybe solved with help of a calculator.     

Performance characteristics of 10 home mechanical ventilators in pressure-support mode: a comparative bench study

OBJECTIVE: Inspiratory pressure (Pi) support delivered by a bilevel device has become the technique of choice for noninvasive home ventilation. Considerable progress has been made in the performance and functionality of these devices. The present bench study was designed to compare the various characteristics of 10 recently developed bilevel Pi devices under different conditions of respiratory mechanics. DESIGN: Bench model study. SETTING: Research laboratory, university hospital. MEASUREMENTS: Ventilators were connected to a lung model, the mechanics of which were set to normal, restrictive, and obstructive, that was driven by an ICU ventilator to mimic patient effort. Pressure support levels of 10 and 15 cm H(2)O, and maximum were tested, with "patient" inspiratory efforts of 5, 10, 15, 20, and 25 cm H(2)O. Tests were conducted in the absence and presence of leaks in the system. Trigger delay, trigger-associated inspiratory workload, pressurization capabilities, and cycling were analyzed. RESULTS: All devices had very short trigger delays and triggering workload. Pressurization capability varied widely among the machines, with some bilevel devices lagging behind when faced with a high inspiratory demand. Cycling was usually not synchronous with patient inspiratory time when the default settings were used, but was considerably improved by modifying cycling settings, when that option was available. CONCLUSIONS: A better knowledge of the technical performance of bilevel devices (ie, pressurization capabilities and cycling profile) may prove to be useful in choosing the machine that is best suited for a patient's respiratory mechanics and inspiratory demand. Clinical algorithms to help set cycling criteria for improving patient-ventilator synchrony and patient comfort should now be developed.