Scale-up of Adhesive Transdermal Drug Delivery Systems

Pharmaceutical Research -     

The contribution of executive processes to deceptive responding

We measured behavioral responses (RT) and recorded event-related brain potentials (ERPs) when participants made truthful and deceptive responses about perceived and remembered stimuli. Participants performed an old/new recognition test under three instructional conditions: Consistent Truthful, Consistent Deceptive and Random Deceptive. Compared to Consistent Truthful responses, Consistent Deceptive responses to both perceived and remembered stimuli produced the same pattern of less accurate, slower and more variable responses and larger medial frontal negativities (MFN). The MFN is thought to reflect activity in anterior cingulate cortex, a brain area involved in monitoring actions and resolving conflicting response tendencies. The Random Deceptive condition required participants to strategically monitor their long-term response patterns to accommodate a deceptive strategy. Even compared to the Consistent Deceptive condition, RTs in the Random Deceptive condition were significantly slower and more variable and MFN activity increased significantly. MFN scalp distribution results revealed the presence of three different patterns of brain activity; one each for truthful responses, deceptive responses and strategic monitoring. Thus, the data indicate that anterior cingulate cortex plays a key role in making deceptive responses.     

A fatal poisoning from Nicotiana glauca

A young adult male was found dead in a field. No cause of death was apparent at autopsy, and the only positive toxicological finding was the presence of a nicotine-like alkaloid isolated from the liver. Anabasine, the major, highly toxic alkaloid of the shrub, Nicotiana glauca (tree tobacco) was subsequently identified in all body specimens examined using gas chromatography/mass spectrometry. Concentrations of anabasine in blood, urine and other body organs are reported.     

Perceptual load affects spatial and nonspatial visual selection processes: an event-related brain potential study

One major question toward understanding selective attention regards the efficiency of selection. One theory contends that this efficiency in vision is determined primarily by the perceptual load (PL) imposed by the relevant stimuli; if this load is high enough to fill attentional capacity, irrelevant stimuli will be excluded before they interfere with task performance, but if this load is lower the spare capacity will be directed automatically to the irrelevant information, which will then interfere with task performance. The current study attempts to test and extend this theory in order to understand better the role of PL by examining its effects on event-related brain potentials (ERPs), voltage fluctuations recorded at the scalp that reflect underlying cognitive operations. Stimuli were presented one at a time, and subjects were instructed to respond to rare deviant stimuli that appeared within a relevant stimulus channel and to ignore stimuli in an irrelevant channel, where channel was defined by either spatial (left, right) or nonspatial (red, blue) attributes in separate tasks. PL was manipulated by varying the similarity between the target/deviant and standard stimulus, and increases in PL were found to increase the magnitude of the relevant-irrelevant difference waveforms in both tasks at predicted temporal windows. These findings suggest that PL affects attentional selection that is tonically maintained across many experimental trials, and does so not only when selection is spatially based but also when it is based upon nonspatial cues.     

Relative Mortality Analysis Of The “Golden Hour”: A Comprehensive Acuity Stratification Approach To Address Disagreement In Current Literature

Objective: This study sought to address the disagreement in literature regarding the “golden hour” in trauma by using the Relative Mortality Analysis to overcome previous studies’ limitations in accounting for acuity when evaluating the impact of prehospital time on mortality.

Methods: The previous studies that failed to support the “golden hour” suffered from limitations in their efforts to account for the confounding effects of patient acuity on the relationship between prehospital time and mortality in their trauma populations. The Relative Mortality Analysis was designed to directly address these limitations using a novel acuity stratification approach, based on patients’ probability of survival (PoS), a comprehensive triage metric calculated using Trauma and Injury Severity Score methodology. For this analysis, the population selection and analysis methods of these previous studies were compared to the Relative Mortality Analysis on how they capture the relationship between prehospital time and mortality in the University of Virginia (UVA) Trauma Center population.

Results: The methods of the previous studies that failed to support the “golden hour” also failed to do so when applied to the UVA Trauma Center population. However, when applied to the same population, the Relative Mortality Analysis identified a subgroup, 9.9% (with a PoS 23%–91%), of the 5,063 patient population with significantly lower mortality when transported to the hospital within 1?hour, supporting the “golden hour.”

Conclusion: These results suggest that previous studies failed to support the “golden hour” not due to a lack of patients significantly impacted by prehospital time within their trauma populations, but instead due to limitations in their efforts to account for patient acuity. As a result, these studies inappropriately rejected the “golden hour,” leading to the current disagreement in literature regarding the relationship between prehospital time and trauma patient mortality. The Relative Mortality Analysis was shown to overcome the limitations of these studies and demonstrated that the “golden hour” was significant for patients who were not low acuity (PoS >91%) or severely high acuity (PoS <23%).     

Fast rhythms in phrenic motoneuron and nerve discharges.

1. Fast rhythms in discharges of individual phrenic (PHR) motoneurons were studied by spectral and interval analyses; and they were compared, using coherence analysis, with similar rhythms in whole-PHR nerve discharge. The purpose of this study was to ascertain the origin of the two rhythms, manifested as distinct spectral peaks, in PHR motoneuron and nerve discharge: medium-frequency oscillations (MFO, usual range 20-50 Hz); and high-frequency oscillations (HFO, usual range 50-100 Hz). 2. In paralyzed artificially ventilated cats, unit recordings were taken from 1) 26 isolated single PHR fibers (in 8 sodium pentobarbital-anesthetized cats) and 2) 27 identified PHR motoneuron somata in the spinal cord (in 5 decerebrate cats). Simultaneous whole-PHR activity was monophasically recorded from the contralateral PHR nerve for 1 and from both PHR nerves for 2. 3. The signals were subjected to time- and frequency-domain analyses. The latter included a novel application of coherence analysis to the study of population synchrony. 4. The autospectra of all PHR units showed prominent MFO peaks in the frequency range of the nerve MFO spectral peaks, as well as harmonic peaks, indicating the presence of this type of fast rhythm in the units' discharges. Spectral analysis of the augmenting PHR activities in different segments of the inspiratory (I) phase showed that the frequency of unit MFO and of nerve MFO rose during the course of I. Further, cycle-triggered histogram and interval analysis indicated that the frequencies of unit MFO autospectral peaks were very close to the peak firing rates of the units during the portion of I analyzed. Thus unit MFO spectral peaks reflected the rhythmic and augmenting discharges of the motoneurons, and similar nerve MFO peaks reflected the superposition of individual motoneuron discharges. 5. The coherences of motoneurons' MFOs to nerve MFOs were low or zero, indicating that only partial and weak MFO correlations occurred within the PHR motoneuron population. 6. In those cats (n = 11) that had clear PHR nerve HFO spectral peaks, about one-half of the recorded PHR motoneurons had HFO, as indicated by HFO peaks in the unit autospectra and/or the unit-nerve coherences. 7. For motoneurons having HFO, the coherence between unit and nerve HFOs was substantial, particularly when the latter were strong, indicating HFO correlations among a number of PHR motoneurons. 8. In the light of theoretical considerations on the generation of aggregate rhythms from superposition of unitary rhythms, these observations indicate the following.(ABSTRACT TRUNCATED AT 400 WORDS)