Stimulant and relaxant drugs combined with stimulant and relaxant information: a study of active placebo

Rationale The active placebo hypothesis states that placebo effects are potentiated when an active drug is administered.Objective This hypothesis was tested in an experiment where information about the effect of a drug was combined with administration of an active drug or placebo.Methods Information that a drug acted as a relaxant, a stimulant, or as a placebo was crossed with oral administration of a relaxant drug (700 mg carisoprodol), a stimulant drug (400 mg caffeine) or placebo (lactose) in healthy volunteers (n=94). Dependent variables were subjective and physiological measures of arousal, as well as serum carisoprodol and caffeine levels. Data were collected from 15 to 280 min after administration of drug or placebo.Results Caffeine increased alertness, systolic and diastolic blood pressure, startle blink reflexes, and skin conductance responses. Subjects were calmer after carisoprodol, and heart rate was increased. There was a positive correlation between increased arousal and carisoprodol levels when stimulant information had been provided. However, this was only seen when carisoprodol levels were very low. There was no evidence that caffeine modulated the placebo response.Conclusions Active placebo responses were seen only transiently when carisoprodol levels were low, and only in the subjective arousal data. Caffeine did not support active placebo responses. The overall findings did not favour the active placebo hypothesis.     

Rationalization of shape and related stress distribution in posterior teeth: a finite element study using nonlinear contact analysis

This study considered the loading configuration of intact teeth by using finite element analyses to rationalize the clinical and biologic advantage inherent to posterior tooth shape. The biomechanical behavior of opposing molars was investigated in consideration of different loadcases simulating working, nonworking, and vertical closing micromotions starting in a position close to maximum intercuspation. The resulting stress distribution was assessed in a numerical model, reproducing 2-D buccolingual cross sections of maxillary and mandibular molars. In each case (working/nonworking/closure), the stroke was applied to the mandibular tooth in a stepping procedure (nonlinear contact analysis) until a total external force of 200 N was attained on the contact nodes. The principal stress distribution and modified Von Mises stresses were extracted from the postprocessing files. Vertical loading of the teeth did not generate harmful concentrations of stress. More challenging situations were encountered during working and nonworking micromotions, both of which generated inverted stress patterns. Supporting cusps were generally well protected during both working and nonworking cases (mostly subjected to compressive stresses). Nonsupporting cusps tended to exhibit more tensile stresses. High stress levels were found in the central groove of the maxillary molar during nonworking micromotion and at the lingual surface of enamel of the mandibular tooth during single-contact working micromotion. The occlusal load configuration as well as geometry and hard tissue arrangement had a marked influence on the stress distribution within opposing molars. Additional computations demonstrated the essential role of enamel bridges and crests to protect the crown from harmful tensile stresses.     

Serum concentrations of theophylline in children following the administration of doses generally recommended: new dosage regimen required.

Serum concentrations of theophylline following intravenous and oral administration of aminophylline were studied in asthmatic children, 2--17 years of age. The biological half-life (t 1/2 beta) of theophylline varied between 165 and 495 min. The results revealed that an intravenous loading dose of 6 mg of aminophylline per kg body weight was necessary in order to obtain therapeutic concentrations in children who had not received the drug for the last 6 to 8 hours. The maintenance dose should be determined and controlled by use of serum concentration determinations. In a group of children receiving 5 mg of aminophylline per kg body weight 3 times a day orally, none had concentrations within the therapeutic range in the morning, and only 39% reached therapeutic levels 2 h after the morning dose. No correlation was found between the serum concentration of theophylline and the amount of drug given per kg body weight. The results show that theophylline concentration analysis is necessary to obtain adequate therapeutic levels in children without risking toxic effects.     

The effect of experimenter gender on autonomic and subjective responses to pain stimuli

Several studies have shown that male subjects report lower pain intensity to female compared to male experimenters. The present experiment examined whether experimenter gender also modulated autonomic pain responses. Sixty-four students (32 females) participated in a 2 Subject gender x 2 Experimenter gender x 15 Pain Tests mixed design. Six experimenters, three females and three males collected data. Heat pain was +48 degrees C induced to the right volar forearm. Subjective measurements consisted of pain intensity, pain unpleasantness, stress, arousal and mood. Autonomic responses were heart rate variability and skin conductance levels. The results revealed significant interactions between experimenter gender and subject gender on pain intensity and arousal, but there were no interactions in the physiological data. In conclusion, the lower pain report in male subjects to female experimenters is not mediated by changes in autonomic parameters, and the effect of experimenter gender is probably due to psychosocial factors.     

Molecular characterization and phylogenetic study of newcastle disease virus isolates from recent outbreaks in eastern Uganda

Newcastle disease virus isolates from chickens in eastern Uganda in 2001 were found to be velogenic by fusion protein cleavage site sequence analysis and biological characterization; the intracerebral pathogenicity index was 1.8. Analysis of their hemagglutinin-neuraminidase protein gene sequences revealed a novel genotype unrelated to those that caused previous outbreaks.     

Demonstration of topographically organized projections from the hypothalamus to the pontine nuclei: an experimental anatomical study in the cat

In 22 cats implantations and injections of horseradish peroxidase-wheat germ agglutinin (HRP-WGA) or Fluoro-Gold were placed in the pontine nuclei or the hypothalamus. The occurrence and distribution of labeled cells in the hypothalamus and of labeled terminal fibers in the pontine nuclei were mapped. Following implantations of HRP-WGA ventromedially in rostral parts of the pontine nuclei, 22-44% of all labeled cells in the brainstem and diencephalon are found in the medial mamillary nucleus ipsilateral to the implantation. Some labeled cells are also found in the supramamillary, premamillary, anterior mamillary, and tuberomamillary nuclei. Thus, labeled cells in the hypothalamus make up 33-54% of all labeled cells in the brainstem and diencephalon in such cases. In contrast, implantations and injections in mediocaudal parts of the pontine nuclei result in labeling of cells mainly in the posterior, dorsal, and lateral hypothalamic areas (terminology of Bleier: The Hypothalamus of the Cat. Baltimore: Johns Hopkins Press, '61). In these cases the labeled cells in the hypothalamus make up 16-25% of all labeled cells in the brainstem and diencephalon. Implantations in more lateral parts of the pontine nuclei label only a few cells in the hypothalamus. Following implantations of HRP-WGA in restricted parts of the hypothalamus, fibers from the medial mamillary nucleus were found to terminate ventromedially at all rostrocaudal levels of the pontine nuclei, ipsilateral to the implantation. In the rostralmost part of the pontine nuclei, the terminal labeling forms a dense, transversely oriented, c-shaped band. Fibers from the posterior and dorsal hypothalamic areas terminate medially and dorsomedially in the caudal third of the pontine nuclei. Sparse terminal labeling is also seen in lateral parts of the pontine nuclei and medially at more rostral levels. In two cases with small implantations of HRP-WGA ventromedially in rostral parts of the pontine nuclei, labeled cells are found both in the medial mamillary nucleus and the cingulate gyrus. Thus, it seems possible that fibers from the medial mamillary nucleus and the cingulate gyrus converge upon a restricted area ventromedially in rostral parts of the pontine nuclei.     

Sensitivity of regression calibration to non‐perfect validation data with application to the Norwegian Women and Cancer Study

Measurement error occurs when we observe error‐prone surrogates, rather than true values. It is common in observational studies and especially so in epidemiology, in nutritional epidemiology in particular. Correcting for measurement error has become common, and regression calibration is the most popular way to account for measurement error in continuous covariates. We consider its use in the context where there are validation data, which are used to calibrate the true values given the observed covariates. We allow for the case that the true value itself may not be observed in the validation data, but instead, a so‐called reference measure is observed. The regression calibration method relies on certain assumptions.This paper examines possible biases in regression calibration estimators when some of these assumptions are violated. More specifically, we allow for the fact that (i) the reference measure may not necessarily be an ‘alloyed gold standard’ (i.e., unbiased) for the true value; (ii) there may be correlated random subject effects contributing to the surrogate and reference measures in the validation data; and (iii) the calibration model itself may not be the same in the validation study as in the main study; that is, it is not transportable. We expand on previous work to provide a general result, which characterizes potential bias in the regression calibration estimators as a result of any combination of the violations aforementioned. We then illustrate some of the general results with data from the Norwegian Women and Cancer Study. Copyright © 2015 John Wiley & Sons, Ltd.     

Occupational therapists' perception of their practice: A phenomenological study

Background:  International literature seems consistent in reporting that occupational therapists value their methods. However, little empirical evidence has been generated supporting the basic system of belief for occupational therapy. Few studies have explored the nature of the occupational therapists' experiences and thoughts about their use of occupation as means and ends, and which strategies they use to implement their tools in their current practice. Accordingly, the aim of this study was to explore how occupational therapists understood and presented their practice and interventions.
Methods:  A sample of six occupational therapists graduated in different decades, from diverse client populations and health-care settings was selected to participate in a semistructured interview.
Results:  Three main themes were developed: 'To make the client's potentials visible', 'reaching a position one values' and 'looking with other eyes'. Whatever their specialities, the participants were unanimous in the way they described their role. Their common focus was 'activities of daily living'. However, they had problems describing their therapeutic tools, and were not able to clearly articulate the 'common sense aspects' of their own methods. The participants were engaged in constructing their professional identities, and stressed the need to construct professional boundaries relevant to their particular work.
Conclusion:  The occupational therapists perceived their practice and interventions as distinctly different from other team members, thus, they provided a 'counterpoint'. The participants used various ways of marketing their perspectives. While the novices tended to go along with the team, the experienced therapists tended to assert their own special contribution.