The Listening Skills Test--a new instrument to assess children's pragmatic ability

Research has established that the development of autonomous (as opposed to collaborative) communication skills, using referential communication speaker and listener tasks, develops only slowly during the primary school years. Such a finding has implications for the classroom which puts a premium on independent language processing. Although the importance of oral language is recognised in the National Curriculum, there has been little attempt to assess the ability formally. The Listening Skills Test is a standardised pragmatic instrument focusing on the 3 1/2-7 years age group. The test is in four parts and assesses the ability to make judgements about the efficacy of verbal messages or instructions. Tasks include relating messages to arrays of pictorial items, making judgements about statements that refer to one complex picture, marking routes on a street plan in response to an extended set of instructions, and the ability to evaluate purely verbal utterances. The overall aim of the test is to assess children's ability to make sense on their own of verbal information in a decontextualised situation thought to represent the nature of much transactional communication in the classroom. Suggestions for remediation that have arisen from research conducted by the authors are also discussed.

Empowerment and the performance of health services

Addresses the issue of empowerment and its possible role in promoting the effectiveness of health services. Empowerment represents the ability of people within organisations to use their own initiative to further organisational interests. However, despite its apparent simplicity, the concept turns out to be quite complex and to have unanticipated implications. We explore some of these implications in health service organisations, and their consequences for health policy. Our conclusion is that many health policies may well act to degrade the empowerment of health service workers, and hence the performance of health service organisations.

Comparison of in vitro and in vivo efficiencies of a novel unit-dose liquid aerosol generator and a pressurized metered dose inhaler

Gamma scintigraphic imaging was employed in 10 healthy volunteers to compare the total and regional lung deposition of aerosols generated by two delivery platforms that permitted microprocessor-controlled actuation at an optimal point during inhalation. An aqueous solution containing 99mTc-DTPA was used to assess the deposition of aerosols delivered by inhalation from two successive unit-dosage forms (44 microl volume) using a prototype of a novel liquid aerosol system (AERx Pulmonary Delivery System). This was compared with aerosol deposition after inhalation of two 50 microl puffs of a 99mTc-HMPAO-labeled solution formulation from a pressurized metered dose inhaler (MDI). The in vitro size characteristics of the radiolabeled aerosols were determined by cascade impaction. For the AERx system, the predicted lung delivery efficiency based on the product of emitted dose (60.8%, coefficient of variation (CV)=12%) and fine particle fraction (% by mass of aerosol particles <5.7 microm in diameter) was 53.3% (CV=13%). For the solution MDI, the emitted dose was 62.9% (CV=13%) and the predicted lung dose was 44. 9% (CV=15%). The AERx system demonstrated efficient and reproducible dosing characteristics in vivo. Of the dose loaded into the device, the mean percent reaching the lungs was 53.3% (CV=10%), with only 6. 9% located in the oropharynx/stomach. In contrast, the lung deposition from the solution MDI was significantly less (21.7%) and more variable (CV=31%), with 42.0% of the radiolabel detected in the oropharynx/stomach. Analysis of the regional deposition of the radioaerosol indicated a homogeneous pattern of deposition after delivery from the AERx system. A predominantly central pattern of distribution occurred after MDI delivery, where the pattern of deposition was biased towards a central zone depicting the conducting airways. The AERx system, in contrast to MDIs, seems highly suited to the delivery of systemically active agents via pulmonary administration.

Lamivudine/zidovudine as a combined formulation tablet: bioequivalence compared with lamivudine and zidovudine administered concurrently and the effect of food on absorption

A single-center, open-label, three-way crossover study was conducted in 24 healthy subjects to assess (1) the bioequivalence of a combined lamivudine 150 mg/zidovudine 300 mg tablet relative to the separate brand-name components administered concurrently and (2) the effect of food on the bioavailability of the drugs from the combination tablet. The subjects were randomly assigned to receive each of the following three treatments, separated by a 5- to 7-day washout period: one lamivudine/zidovudine combination tablet after an overnight fast, one lamivudine 150 mg tablet and one zidovudine 300 mg tablet simultaneously after an overnight fast, or one lamivudine/zidovudine combination tablet 5 minutes after completing a standardized high-fat breakfast (67 g fat, 58 g carbohydrate, and 33 g protein). Serial blood samples were collected up to 24 hours postdose for the determination of lamivudine and zidovudine plasma concentrations. Standard pharmacokinetic parameters were estimated. Treatments were considered bioequivalent if 90% confidence intervals for the ratio of least squares (LS) means for the lamivudine and zidovudine area under the plasma concentration-time curve (AUC infinity) and maximum observed plasma concentration (Cmax) fell entirely within 0.80 to 1.25 for log-transformed parameters. The combined lamivudine/zidovudine tablet was bioequivalent in the extent (AUC infinity) and rate of absorption (Cmax and time of Cmax [tmax]) to the individual brand-name drug components administered concurrently under fasted conditions. Geometric LS mean ratios and 90% confidence intervals for AUC infinity and Cmax were 0.97 (0.92, 1.03) and 0.94 (0.84, 1.06), respectively, for lamivudine and 0.99 (0.91, 1.07) and 0.97 (0.82, 1.15), respectively, for zidovudine. The extent of absorption of lamivudine and zidovudine from the combination tablet was not altered by administration with meals, indicating that this formulation may be administered with or without food. However, food slowed the rate of absorption, delayed the tmax, and reduced the Cmax of lamivudine and zidovudine. These changes were not considered clinically important. All formulations were well tolerated under fasted and fed conditions.

Macaques infected with cloned simian immunodeficiency virus show recurring nef gene alterations

We compared nef gene sequences isolated by polymerase chain reaction from peripheral blood lymphocyte DNA of macaques that had been inoculated with either biologically (E11S) or molecularly (clone 8) cloned SIV/Mne. Two samples from each animal obtained either early (weeks 2-8) or late (weeks 21-137) after infection were analyzed. Three substitutions in the predicted Nef amino acid sequence were seen in all animals at the late time point, and two other substitutions were seen in all except one. Two of the common exchanges are located approximately 40 residues apart in the Nef core sequence but are juxtaposed on the tertiary structure as judged by computer modeling using the structure of the HIV Nef core protein as a guide. Most recurrent in vivo changes replaced a residue found in the cloned Nef sequence with one present in a consensus derived by aligning the Nef sequences of the SIV/Sm clade. Recombinant virus containing a macaque-adapted (MA nef) nef on the clone 8 backbone was 3-fold more infectious on SMAGI cells than the original virus. A lymphocyte line infected with SIV-clone 8-MAnef contained a large proportion of cells carrying provirus with defective nef genes. These findings suggest that the nef gene of the cloned SIV/Mne had undergone attenuating mutations during propagation in tissue culture that were "corrected" in vivo.

Communications. Off message

More than half of NHS organisations now have a communications post. Almost half of all communications managers are working single-handed. Most earn 30,000 Pounds or less. The typical NHS organisation spends less than 75,000 Pounds a year on communications, notably less than many local authorities. The present level of investment in communications is woefully inadequate to deliver the new NHS envisaged by the government.

The effect of age on the pharmacokinetics of valsartan

Twelve young (mean age 23 years, range 18-28) and 12 elderly (mean age 76 years, range 65-89) volunteers were given a single oral dose of 80 mg valsartan after an overnight fast. Each group consisted of six male and six female subjects. Mean systemic exposure to valsartan was higher in the elderly when compared with the young (AUC(0-24 h), 52% increase and AUC(0-infinity), 70% increase). Variability, as shown by the coefficient of variation (CV), was larger for the elderly subjects and ANOVA of the log transformed AUC showed a significant difference between the two groups. This difference was largely brought about by five elderly subjects (one male, four females), whose AUC was about 2-fold higher than the rest of the group. For the remaining elderly subjects, plasma valsartan AUC was similar to that observed for the young volunteers. This higher systemic exposure in five of the elderly subjects is not thought to be of clinical relevance when data from the patient population are considered. Other covariates--such as body weight, comedication, creatinine clearance, valsartan kinetics (absorption rate, distribution, and elimination)--did not explain the higher AUC in this subset of the elderly group. Data from the present study were compared with population kinetic data obtained from larger clinical trials including hypertensive patients in all age groups. Using this population approach, there was no difference in the pharmacokinetics of valsartan between male and female patients. Also, a relationship between plasma clearance of valsartan and age was established. The median age of patients in the hypertensive pool was 55 years. For an average 70-year-old patient, plasma clearance of valsartan is predicted to fall by 22% compared with an average 55-year-old. For the population this difference is not sufficient to warrant initial dose adjustment based on age per se. The covariate age, does not completely explain the variability in the pharmacokinetics of valsartan within the general population. The treatment was well tolerated.

Inhalation delivery systems with compliance and disease management capabilities

Non-compliance with prescribed medication is a major reason for poor therapeutic outcomes, leading to unnecessary contributions to healthcare costs. Poor technique in self-administration of inhalation therapy is a special type of non-compliance associated with this route of administration. However, pulmonary drug delivery has fundamental advantages for therapy of diseases of the respiratory tract because it is site-directed. The lung is also a promising portal for drug delivery into the systemic circulation. Incorporation of microprocessors into pulmonary drug delivery systems facilitates sophisticated compliance management of chronic diseases such as asthma and diabetes. Microprocessor-assisted systems afford control of patients' administration technique during the therapeutic inhalation event, thus leading to efficient and reproducible regional deposition of the inhaled drug or diagnostic agent. SmartMist is a hand-held asthma disease management device that aids patients to use optimally metered dose inhalers. It also measures pulmonary lung function and provides a long term downloadable electronic record of the therapeutic and diagnostic events. The AERx pulmonary delivery system utilizes similar microprocessor capabilities; however, it employs a novel means of generating aqueous aerosols from unit dose packages, thus providing a broad inhalation technology base for delivery of a wide variety of therapeutic and diagnostic agents into the respiratory tract, and via the lung into the systemic circulation.

The secondary radiation grid; its effect on fluoroscopic dose-area product during barium enema examinations

The secondary radiation grid is placed between the patient and the image intensifying screen, during fluoroscopy, to attenuate the incident forward scattered radiation. This reduction in scatter improves the radiographic contrast and hence image quality. However, this improved quality is achieved at the expense of greater radiation exposure to the patient, as this higher exposure is required to produce satisfactory image density. Patients scheduled to have a barium enema were randomly allocated into two groups. One group had the procedure performed with the grid in situ throughout the procedure. The second group was examined with the grid removed for fluoroscopy but returned for image acquisition. The fluoroscopic dose-area product (DAP) was recorded for both groups using a dose-area product meter. The DAP was not recorded for spot film acquisition. The results suggest that there is approximately a 50% reduction in DAP to the second group. We can be 95% certain that, on average, the ratio of doses in patients without the grid in situ to those screened with the grid is between 0.40 and 0.58, with the best estimate being 0.48. Multiple regression methods to take account of the effects of weight, sex and time, revised this estimate as 0.57, with 95% confidence interval from 0.52 to 0.63. Sex, weight and exposure time accounted for 61% of variation in dose-area products, with time alone accounting for 41%. Grid status accounted for another 22% of variation, which represents over a half of the remaining variation once sex, weight and exposure time have been allowed for. We therefore recommend that the routine use of an antiscatter grid during fluoroscopy should be abandoned. The use of a grid should be restricted to those patients (usually obese) when poor visualization is obtained in its absence.

Morphine pharmacokinetics after pulmonary administration from a novel aerosol delivery system

BACKGROUND

Successful pharmacotherapy of pain often depends on the mode of drug delivery. A novel, unit dose, aqueous aerosol delivery system (AERx Pulmonary Drug Delivery System) was used to examine the feasibility of the pulmonary route for the noninvasive systemic administration of morphine.

METHODS

The study had two parts: (1) a dose-ranging study in four subjects with three consecutive aerosolized doses of 2.2, 4.4, and 8.8 mg (nominal) morphine sulfate pentahydrate at 40-minute intervals, and (2) a crossover study, on separate days, in six subjects with 4.4 mg (nominal) aerosolized morphine sulfate administered over 2.1 minutes on three occasions and intravenous infusions of 2 and 4 mg over 3 minutes. Subjects were healthy volunteers from 19 to 34 years old. Arterial blood was sampled for a total of 6 hours and plasma morphine concentrations were measured by gas chromatography-mass spectrometry.

RESULTS

In part 1, plasma morphine concentrations were proportional to dose. In part 2, the mean +/- SD peak plasma concentration (Cmax) occurred at 2.7 +/- 0.8 minutes after the aerosol dose, with mean values for Cmax of 109 +/- 85, 165 +/- 22, and 273 +/- 114 ng/ml for the aerosol and 2 and 4 mg intravenous doses, respectively. The bioavailability [AUC(0-360 min)] of aerosol-delivered morphine was approximately 100% relative to intravenous infusion, with similar intersubject variability in AUC for both routes (coefficient of variation < 30%).

CONCLUSION

The time courses of plasma morphine concentrations after pulmonary delivery by the AERx system and by intravenous infusions were similar. This shows the utility of the pulmonary route in providing a noninvasive method for the rapid and reproducible systemic administration of morphine if an appropriate aerosol drug delivery system is used.

Does drawing attention to the referent constrain the way in which children construct verbal messages?

Tasks which assess children's speaker skills in the referential communication paradigm frequently mark the target item in some way to indicate which picture should be described. It was hypothesized that this procedure would interfere with effective scanning of the visual array (comparison processing) assumed to be necessary for the production of accurate messages. It was also predicted that, when one item was highlighted, more redundant features would be included in messages. An experiment which compared a marked with an unmarked target condition across three age ranges (6, 8, 10 years) found that message accuracy was not affected by highlighting. But significantly more redundant features were reported in the marked condition, indicating that, where redundancy is the focus of interest, a highlighting procedure should be avoided. Two age effects were also found: Message accuracy improved with age, while redundancy reduced with age.

Pharmacokinetics of valsartan in patients with liver disease

OBJECTIVES

Valsartan (CGP 48933), an orally active angiotensin II antagonist, is eliminated mainly by hepatic clearance. To characterize the compound(s) excreted in the bile, biliary excretion of valsartan was investigated by collection of bile after an intravenous dose of valsartan. In addition, to determine the exposure to valsartan when liver function is impaired, a pharmacokinetic study (open, single dose) was performed in patients with mild and moderate impairment of liver function.

PATIENTS

Biliary excretion of valsartan (after intravenous administration of 20 mg valsartan) was assessed in a patient who underwent a hepaticojejunostomy with subsequent bile drainage. Exposure to valsartan in patients with mild (n = 6) or moderate (n = 6) impaired liver function (Child's-Pugh classification) and matching (sex, age, and weight) healthy volunteers (n = 12) was studied after oral administration of a single dose of 160 mg valsartan.

RESULTS

After intravenous administration, valsartan was eliminated mainly as unchanged drug in the bile. Mean exposure (measured as area under the plasma valsartan concentration-time curve) to valsartan was increased about twofold in both the mild and the moderate groups compared with matched (age, sex, and weight) healthy volunteers.

CONCLUSION

These data are consistent with the pharmacokinetics of valsartan in that biliary excretion is the main route of elimination.

The AERX aerosol delivery system

PURPOSE

We describe the AERX aerosol delivery system, a new, bolus inhalation device that is actuated at preprogrammed values of inspiratory flow rate and inhaled volume. We report on its in vitro characterization using a particular set of conditions used in pharmacokinetic and scintigraphic studies.

METHODS

Multiple doses of aerosol were delivered from single use collapsible plastic containers containing liquid formulation. The aerosol was generated by forcing the formulation under pressure through an array of 2.5 micron holes. Air was drawn through the device at 70 LPM, and the aerosol was collected onto a filter or Andersen cascade impactor. The emitted dose was quantified from the filter collection data, and the particle size distribution was obtained from the best fit log-normal distribution to the impactor data.

RESULTS

57.0 +/- 5.9% of the dose of drug placed as an aqueous solution in the 45 microL collapsible container was delivered as an aerosol (n = 40). The best fit size distribution had an MMAD = (2.95 +/- 0.06) microns and a geometric standard deviation sigma g = 1.24 +/- 0.01 (n = 6).

CONCLUSIONS

The AERX aerosol delivery system generates a nearly monodisperse aerosol with the properties required for efficient and repeatable drug delivery to the lung.

The effect of valsartan on the angiotensin II pressor response in healthy normotensive male subjects

OBJECTIVE

Valsartan is an oral antagonist of angiotensin II that competes with angiotensin II for the AT1-receptor and is being developed as an antihypertensive agent. This study assessed the ability of 80 mg valsartan to inhibit the pressor effect of exogenous angiotensin II in healthy normotensive men, first after a single dose and then after multiple doses once daily for 7 days.

METHODS

This was a single-center, double-blind, placebo-controlled, randomized crossover study. Six healthy men underwent angiotensin II challenges to determine a suitable dose required to increase their systolic blood pressure by approximately 30 mm Hg. Each subject then received an 80 mg dose of valsartan or matching placebo. The inhibition of the angiotensin II pressor effect was determined by the systolic blood pressure response to repeated angiotensin II challenges at multiple time points.

RESULTS

Systolic blood pressure responses to angiotensin II challenges after single and multiple doses of valsartan were significantly lower than placebo, indicating that valsartan blocked the blood pressure response to angiotensin II. The maximum blocking effect was observed within 2 to 3 hours. Mean data suggested that differences in effect between valsartan and placebo were similar after both single and multiple doses and persisted up to 24 hours after administration. The angiotensin II blocking effect was maintained up to this time, despite low plasma valsartan levels and minimal accumulation after multiple doses.

CONCLUSION

Valsartan, 80 mg, is a potent angiotensin II antagonist with a rapid onset of action and persistent angiotensin II inhibition up to 24 hours. There is no attenuation of this effect after multiple doses.

Effect of a 15-minute infusion of DDAVP on the pharmacokinetics and pharmacodynamics of REVASC during a four-hour intravenous infusion in healthy male volunteers

Plasma pharmacokinetics, effect on coagulation parameters, and safety and tolerability of an intravenous infusion of REVASC before, during and after a DDAVP infusion were investigated. Twelve healthy volunteers were given an intravenous bolus dose followed by a constant rate four-hour infusion of REVASC. Fifteen-minute infusions of 0.9% saline and DDAVP were started two and three hours respectively after the start of the REVASC infusion. Plasma REVASC concentrations were not affected by either the saline or DDAVP infusion. REVASC infusion produced an increase in APTT which plateaued between 0.5 and 3 hours. After the DDAVP infusion there was a tendency towards a new lower plateau whilst the REVASC infusion continued. There were no serious adverse events or bleeding episodes throughout the study. In conclusion, the co-administration of intravenous DDAVP has no effect on the plasma pharmacokinetics of REVASC and partially reverses the REVASC-induced increase in APTT. This may represent a role for DDAVP in the partial reversal of anticoagulation induced by REVASC.

Absolute bioavailability and pharmacokinetics of valsartan, an angiotensin II receptor antagonist, in man

OBJECTIVE

The pharmacokinetics of orally and intravenously administered valsartan were determined in two studies. In a first pilot study, three i.v. doses of valsartan were given in an ascending manner (5, 10 and 20 mg) to evaluate tolerability and basic pharmacokinetics of the i.v. formulation. In a second study, the absolute bioavailability of 80 mg valsartan from a capsule and a buffered solution was compared with a 20 mg i.v. dose.

METHODS

The concentrations of valsartan in plasma and urine were measured using HPLC. The disposition of valsartan after an i.v. dose was characterized by biphasic decay kinetics, with a distribution phase (half-life 1.0 h), followed by a longer elimination phase (half-life 9.5 h). The volume of distribution at steady state was 16.9 l, and the total body clearance 2.2 l.h-1. 29% of the i.v. dose was recovered unchanged in the urine.

RESULTS

Plasma levels peaked 2 h after oral administration of the 80 mg capsule. Thereafter, plasma levels declined biexponentially with a terminal t1/2 of 7.0 h. Cmax was reached 1 h after administration of the solution, and t1/2 was 7.5 h. On average 7.3% (capsule) and 12.6% (solution) of the dose was excreted in the urine as the unchanged drug. The fraction of dose absorbed and systemically available after oral administration was 0.23 for the capsule and 0.39 for the solution, based on AUC. Absorption appeared to follow two first-order processes. The first phase was rapid, with a half-life of 0.5 h and 0.9 h for solution and capsule, respectively. The slower absorption phase was characterized by a half-life of 6.5 h for the solution and 3.5 h for the capsule. Most of the drug was absorbed during the period 0.4 h to 3 h post-dosing, and 90% of the fraction absorbed from the capsule was absorbed within 5 h.

Validation of the MMPI-2 Low Self-Esteem Content Scale

We explored the concurrent validity of the MMPI-2 Low Self-Esteem (LSE) Content scale by asking 216 undergraduate students to complete the Minnesota Multiphasic Personality Inventory-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1991), Harter Adult Self-Perception Profile (Harter, 1986a) and Rosenberg Self-Esteem Scale (Rosenberg, 1965). Results suggest the LSE renders a good assessment of global self-esteem as well as being a measure of three distinct components of self-esteem. These specific subscales, identified by factor analysis, were labeled Ineptitude, Negative Self-Value, and Negative Comparison with Others. The LSE and its subscales produced good internal consistency (alpha and Gutman Split Half) coefficients.