The ethics of attaching research conditions to access to new health technologies

Decisions on which new health technologies to provide are controversial because of the scarcity of healthcare resources, the competing demands of payers, providers and patients and the uncertainty of the evidence base. Given this, additional information about new health technologies is often considered valuable. One response is to make access to a new health technology conditional on further research. Access can be restricted to patients who participate in a research study, such as a randomised controlled trial; alternatively, a new treatment can be made generally available, but only on condition that further evidence is collected (eg, on long-term outcomes and adverse events, in patient registries). The National Institute for Health and Clinical Excellence (NICE), which provides guidance on which new health technologies to make available under the UK's NHS, for example, has made some research conditional recommendations, and the current interest in such options suggests that they are likely to become more prevalent in the future. This paper identifies and discusses the main ethical issues created by this distinctive range of recommendations. We argue that decisions to put research conditions on access to new technologies are compatible with widely accepted values, principles and practices relevant to resource allocation. However, there are important features of these distinctive judgements that must be taken into account by resource allocation decision-making bodies and research ethics committees, and that require new sorts of empirical data.

The virtue ethics approach to bioethics

This paper discusses the viability of a virtue-based approach to bioethics. Virtue ethics is clearly appropriate to addressing issues of professional character and conduct. But another major remit of bioethics is to evaluate the ethics of biomedical procedures in order to recommend regulatory policy. How appropriate is the virtue ethics approach to fulfilling this remit? The first part of this paper characterizes the methodology problem in bioethics in terms of diversity, and shows that virtue ethics does not simply restate this problem in its own terms. However, fatal objections to the way the virtue ethics approach is typically taken in bioethics literature are presented in the second section of the paper. In the third part, a virtue-based approach to bioethics that avoids the shortcomings of the typical one is introduced and shown to be prima facie plausible. The upshot is an inviting new direction for research into bioethics' methodology.

FMRI activation in language areas correlates with verb generation performance in children

Functional MRI mapping of language areas in children frequently employs a covert verb generation task. Because responses are not monitored, the relationship between fMRI activation and task performance is unknown. We compared fMRI activation during covert and overt verb generation to performance during the overt task. 15 children, ages 11-13 years, listened to concrete nouns and responded with related verbs covertly and overtly. A clustered fMRI acquisition allowed for recording of overt responses without motion artifacts. Region of interest analysis was also performed in areas that exhibited correlation between activation and performance during overt verb generation in left inferior frontal and left superior temporal gyri (along with their right hemisphere homologues). Regression analysis determined that during both covert and overt generation, left hemisphere regions showed positive correlations with average counts of verbs generated during the overt task. These results suggest that increased verb generation performance leads to increased activation. In addition, overt performance may be used as an estimator of covert performance.

Comparative disposition of [14C]ertapenem, a novel carbapenem antibiotic, in rat, monkey and man

1. The disposition and metabolism of ertapenem, a carbapenem antibiotic, was examined in rat, monkey and man. Sprague-Dawley rats and Rhesus monkeys were given, by intravenous administration, radiolabelled doses of ertapenem (60 and 30 mg kg(-1), respectively), and healthy normal volunteers received a single fixed dose of 1000 mg. Urine and faeces were collected for determination of total radioactivity. 2. In healthy volunteers, [14C]ertapenem was eliminated by a combination of hydrolytic metabolism to a beta-lactam ring-opened derivative and renal excretion of unchanged drug. Approximately equal amounts were excreted as a beta-lactam ring-opened metabolite and unchanged drug (36.7 and 37.5% of dose, respectively). A secondary amide hydrolysis product accounted for about 1% of the dose in man. About 10% of the administered radioactivity was recovered in faeces, which suggested that a minor fraction underwent biliary and/or intestinal excretion. 3. In animals, a greater fraction of the dose was eliminated via metabolism; excretion of unchanged drug accounted for 17 and 5% of dose in rats and monkeys, respectively. In monkeys, the beta-lactam ring-opened and amide hydrolysis metabolites accounted for 74.8 and 7.59% of the dose, respectively, whereas in rats, these metabolites accounted for 31.9 and 20% of dose, respectively. 4. In vitro studies with fresh rat tissue homogenates indicated that lung and kidney were the primary organs involved in mediating formation of the beta-lactam ring-opened metabolite. The specific inhibitor of dehydropeptidase-I, cilastatin, inhibited the in vivo and in vitro metabolism of ertapenem in rats, which suggested strongly that the hydrolysis of ertapenem in lung and kidney was mediated by this enzyme.

Effect of polymer molecular weight on the production of drug nanoparticles

Stable, polymer-coated nanoparticles of two hydrophobic drugs, namely nabumetone and halofantrine, have been prepared by a wet-bead milling process performed in the presence of a stabilizing homopolymer, either hydroxypropylmethylcellulose (HPMC) or polyvinylpyrrolidone (PVP), of differing molecular weights and concentrations. Although nabumetone nanoparticles could only be produced when HPMC was used as stabilizing polymer, halofantrine nanoparticles could be prepared using either HPMC or PVP. Stable nanoparticles of nabumetone could be produced using a HPMC solution of viscosity average molecular weight, M(v), of 5 kg/mol over an approximate four fold polymer concentration range (0.63-2.5% w/w) when a drug loading of 20% w/w was used. Increasing the molecular weight of HPMC up to a limiting M(v) of 89 kg/mol did not result in the formation of nanoparticles at any of the polymer concentrations examined. The amount of polymer absorbed onto the nanoparticles was determined by measuring the depletion of polymer from solution based on either an ultra-violet (PVP) or optical rotatory dispersion (ORD) (HPMC) assay. The slightly lower concentration of HMPC found to be present on the surface of the halofantrine nanoparticles compared with the nabumetone nanoparticles suggested a differing affinity of the polymer for the surface of the two drugs.

Measurements of atmospheric brightness temperature fluctuations and their implications on passive remote sensing

Passive remote sensing of airborne chemicals at infrared wavelengths may be limited by temporal fluctuations in atmospheric brightness temperatures deltaT(t). Brightness temperatures in two infrared spectral bands were simultaneously measured on clear and cloudy days along three lines of sights. For time windows t < 3-5 s, deltaT(t) remained constant at the sensor noise level and rapidly increased as t increased. The fluctuation time scale for the cloudy day was longer than for the clear day. The long correlation time for T(t) limits the utility of signal averaging in improving detection signal-to-noise ratio (SNR). The simultaneous outputs of the two spectral channels during the clear day exhibited no spectral coherence at t < 3 s and limited coherence at t > 30 s. Measurements during the cloudy day were largely coherent. Consequently, band-by-band subtraction may have limited benefits.

Peer networks, parental attributes, and drug use among Asian-Indian adolescents born in the United States

This study examined the interrelationships among peer networks, parental attributes, and drug use among Asian-Indian adolescents born in the United States whose parents emigrated from India. The sample consisted of 200 Asian-Indian adolescents, 116 males and 84 females, aged 13 to 18, who were born in the United States and resided in the greater New York metropolitan area. The subjects were interviewed using a semistructured instrument adapted from relevant validated scales and items from other researchers. Adolescent-reported data were analyzed using descriptive and univariable techniques. Of the 200 subjects, 32.5% had tried some form of tobacco, alcohol, or other drug, and 67.5% did not report drug use of any kind. The adolescents stated whether they had ever (at least one time) smoked cigarettes (16.5%), drank beer (18%), drank wine (20.5%), or smoked marijuana (2.5%). The parents' communication of the harmful consequences of drug use and approval of the adolescents' peer networks correlated (p < .05) independently with less drug use by the adolescents. The parents' concern for education was positively correlated (p < .05) with the adolescents' academic performance. The prevalence of drug use among Asian-Indian adolescents is low. Parents' awareness of their children's school performance, peer networks, and concerns related to the consequences of drug use can be used as an effective mechanism to communicate the prevention of drug use among adolescents.

Resonances in ferromagnetic gratings detected by microwave photoconductivity

We investigate the impact of microwave excited spin excitations on the dc charge transport in a ferromagnetic (FM) grating. We observe both resonant and nonresonant microwave photoresistance, which are caused, respectively, by spin and charge dissipations of the microwave power into the FM. A macroscopic model based on Maxwell and Landau-Lifschitz equations reveals the mixing of spin and charge dissipations, which shows that the ferromagnetic anti-resonance is shifted when the conductivity is anisotropic. We find that the microwave photoconductivity provides a powerful new tool to study the interplay between photonic, spintronic, and charge effects in FM microstructures.

Quantized dispersion of two-dimensional magnetoplasmons detected by photoconductivity spectroscopy

We find that the long-wavelength magnetoplasmon, resistively detected by photoconductivity spectroscopy in high-mobility two-dimensional electron systems, deviates from its well-known semiclassical nature as uncovered in conventional absorption experiments. A clear filling-factor dependent plateau-type dispersion is observed that reveals a so far unknown relation between the magnetoplasmon and the quantum Hall effect.

Bluetongue surveillance methods in the United States of America

Historical surveillance for bluetongue virus (BTV) exposure in the United States of America (USA) has relied on periodical serological surveillance using samples collected from cattle at slaughter. Most of this surveillance has been focused on the north-eastern portion of the USA due to the lack of competent vectors of BTV in this region. For most of the states tested in this region, the prevalence of seropositive animals has been less than 2%. Recently, a study was conducted in north-central USA using sentinel cattle herds. Results of serological testing showed an increasing gradient of exposure from north to south. In addition, detection of Culicoides sonorensis showed a similar gradient with detection in the northern areas being relatively rare. The results of these studies indicate that cattle herds in the northern and north-eastern areas of the USA are likely to be free of BTV.

Pharmacokinetics of total and unbound ertapenem in healthy elderly subjects

Ertapenem is a new once-a-day parenteral carbapenem antimicrobial agent. The pharmacokinetics of unbound and total concentrations of ertapenem in plasma were investigated in elderly subjects and compared with historical data from young adults. In a single- and multiple-dose study, healthy elderly males and females (n = 14) 65 years old or older were given a 1-g intravenous (i.v.) dose once daily for 7 days. Plasma and urine samples collected for 24 h on days 1 and 7 following administration of the 1-g doses were analyzed by reversed-phase high-performance liquid chromatography. Areas under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) for elderly females and males were similar following administration of 1-g single i.v. doses, and thus, the genders were pooled in subsequent analyses. Concentrations in plasma and the half-life of ertapenem were generally higher and longer, respectively, in elderly subjects than in young adults. The mean AUC(0- infinity ) of total ertapenem in the elderly was 39% higher than that in young subjects following administration of a 1-g dose. The differences were slightly greater for the mean AUC(0- infinity ) of unbound ertapenem (71%). The unbound fraction of ertapenem in elderly subjects ( approximately 5 to 11%) was generally greater than that in young adults ( approximately 5 to 8%). As in young adults, ertapenem did not accumulate upon multiple dosing in the elderly. The pharmacokinetics of ertapenem in elderly subjects, while slightly different from those in young adults, do not require a dosage adjustment for elderly patients.

Pharmacokinetics of ertapenem in healthy young volunteers

Ertapenem (INVANZ) is a new once-a-day parenteral beta-lactam antimicrobial shown to be effective as a single agent for treatment of various community-acquired and mixed infections. The single- and multiple-dose pharmacokinetics of ertapenem at doses up to 3 g were examined in healthy young men and women volunteers. Plasma and urine samples collected were analyzed using reversed-phase high-performance liquid chromatography with UV detection. Ertapenem is highly bound to plasma protein. The protein binding changes from approximately 95% bound at concentrations of <50 micro g/ml to approximately 92% bound at concentrations of 150 micro g/ml (concentration at the end of a 30-min infusion following the 1-g dose). The nonlinear protein binding of ertapenem resulted in a slightly less than dose proportional increase in the area under the curve from 0 h to infinity (AUC(0- infinity )) of total ertapenem. The single-dose AUC(0- infinity ) of unbound ertapenem was nearly dose proportional over the dose range of 0.5 to 2 g. The mean concentration of ertapenem in plasma ranged from approximately 145 to 175 micro g/ml at the end of a 30-min infusion, from approximately 30 to 34 micro g/ml at 6 h, and from approximately 9 to 11 micro g/ml at 12 h. The mean plasma t(1/2) ranged from 3.8 to 4.4 h. About 45% of the plasma clearance (CL(P)) was via renal clearance. The remainder of the CL(P) was primarily via the formation of the beta-lactam ring-opened metabolite that was excreted in urine. There were no clinically significant differences between the pharmacokinetics of ertapenem in men and women. Ertapenem does not accumulate after multiple once-daily dosing.