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Biomedical subjects

C Drake

Publications and source records attributed to C Drake.

At least 19 recordsLinked to original sources
PubMed2005

Clinical impact of timely reporting of IgM for West Nile Virus.

BACKGROUND: In 2002 diagnostic testing for West Nile Virus (WNV) infection was not ideal because commercial products were unavailable. Although testing was performed without charge by public health (PH), testing is not intended to be used for patient management and generally results are not available in a timely or reliable manner. OBJECTIVES: This study was conducted to determine the clinical impact of having WNV serology available by a diagnostic laboratory within a few days of sample collection. STUDY DESIGN: An IgM immunoassay (FT, from Focus Technologies) was performed August 13, 2003 to October 31, 2003 Monday, Wednesday and Friday in our hospital's virology laboratory with split sample testing at PH. All results (positive and negative) were called to physicians. RESULTS AND CONCLUSIONS: Turn-around time for the FT assay was within 0-3 days; for PH, it was approximately 8 days. Of 95 samples, 6 were positive and 89 negative. For the FT negative samples, all were concordant with PH, but four FT positive samples (three sera and one cerebrospinal fluid) were discrepant. After resolution of the discrepancies, the FT test had a sensitivity of 100% and a specificity of 99%. Physicians reacted positively to having results faster. Fifty-eight percent of the results had clinical impact, 22% had undetermined impact, 13% were patient requests, and 4% had no impact. Concluding, the FT assay is 100% sensitive and 99% specific and in 58% there was clinical impact for WNV reporting in a timely manner.

Antibodies, Viral↗
PubMed2004

Preferred perceptual tempo for sound sequences: comparison of adults, children, and infants.

Previous motor and perceptual tasks have found optimal processing for sound sequences of a rate of around 600 msec. IOI (Interonset Interval). This zone of optimal processing (the rate at which discrimination is optimal) slows with age and is also found with infants. The current work investigated whether listeners "prefer" sequences at the rate for which they demonstrate optimal processing. In the present study, three experiments were done. Exp. 1 measured tempo preferences in adults who listened to pairs of isochronous sound sequences varying in tempo (from 100- to 1500-msec. IOI) and were required to indicate which they preferred. As expected, highest preferences were expressed for the intermediate tempi, supporting the hypothesis of a zone of preferred tempi comparable to the zone of optimal processing. Moreover, this preference for intermediate tempi was not affected by the temporal context (absence of differences between a fast, a slow, and a wide set of tempi). In Exp. 2, the same procedure was applied to 6- and 10-yr.-olds. Children in both groups had systematic preferences for the fastest tempi within a set, and the older children generally preferred slower sequences. Exp. 3 used a preference paradigm for sound sequences with 4-mo.-old infants, comparing sequences of 100- vs 300-msec. IOI, 300- vs 900-msec. IOI, and 100- vs 900-msec. IOI. No systematic tempo preferences were observed. We conclude that tempo discrimination and tempo preference may have some commonality (perhaps related to a zone of optimal processing), especially in adults, but that they also involve quite distinct processes which undergo different developmental sequences. Whereas adults prefer what they process the best, children prefer what is fastest (and therefore more attention-getting), and we have not been able to detect preferences in infants.

Adult↗
PubMed2001

Some forms of cAMP-mediated long-lasting potentiation are associated with release of BDNF and nuclear translocation of phospho-MAP kinase.

Long-lasting forms of synaptic plasticity like the late phase of LTP (L-LTP) typically require an elevation of cAMP, the recruitment of the cAMP-dependent protein kinase (PKA), and ultimately the activation of transcription and translation; some forms also require brain-derived neurotrophic factor (BDNF). Both cAMP and BDNF can activate mitogen-activated protein kinase (MAPK/ERK), which also plays a role in LTP. However, little is known about the mechanisms whereby cAMP, BDNF, and MAPK interact. We find that increases in cAMP can rapidly activate the BDNF receptor TrkB and induce BDNF-dependent long-lasting potentiation at the Schaffer collateral-CA1 synapse in hippocampus. Surprisingly, in these BDNF-dependent forms of potentiation, which are also MAPK dependent, TrkB activation is not critical for the activation of MAPK but instead appears to modulate the subcellular distribution and nuclear translocation of the activated MAPK.

Active Transport, Cell Nucleus↗
PubMed2001

R-Mix cells are faster, at least as sensitive and marginally more costly than conventional cell lines for the detection of respiratory viruses.

OBJECTIVE: To evaluate shell vials of R-Mix, a combination of mink lung cells and human adenocarcinoma cells (strains Mv1Lu and A549, respectively, Diagnostic Hybrids, Athens, OH) to detect respiratory viruses from prospective clinical respiratory specimens and frozen stocks. STUDY DESIGN: We compared the performance of R-Mix to conventional culture (CC) using tubes of PMK, Hep-2, and MRC5 to detect respiratory viruses from fresh clinical specimens. For each respiratory specimen submitted to virology, two shell vials of R-Mix were inoculated and examined twice (generally after 24 and 48 h) by an indirect test with a pool of immunofluorescent antisera to influenza A and B, adenovirus, parainfluenza 1-3 and RSV (DAKO, Carpinteria, CA). If positive, testing with monoclonal antisera was done. CCs were incubated for 10 days, examined daily for cytopathological effect, hemadsorbed twice and stained if positive. Cost comparison was done. Lastly, respiratory viruses frozen from previous years were inoculated onto R-Mix. RESULTS: R-Mix was positive for all 29 frozen virus stocks. In the clinical trial, 396 prospective specimens were inoculated into R-Mix and CC. R-Mix identified 21 specimens as respiratory virus positive; CC identified 19. Turn-around time of R-Mix for positive specimens was 1.4 days; for CC it was 5.2 days. Turn-around time of R-Mix for all specimens (positive and negative) was 2.0 days; for CC it was 9.8 days. The overall cost of R-Mix was approximately 11% more than that of CC. CONCLUSION: R-Mix enabled rapid identification of all the frozen virus stocks representing the seven major respiratory viral groups. When compared to CC, R-Mix was slightly more sensitive than three cell lines (four tubes) used in CC but it was several days faster.

Adenovirus Infections, Human↗
PubMed2001

The quest for universals in temporal processing in music.

Music perception and performance rely heavily on temporal processing: for instance, each event must be situated in time in relation to surrounding events, and events must be grouped together in order to overcome memory constraints. The temporal structure of music varies considerably from one culture to another, and so it has often been supposed that the specific implementation of perceptual and cognitive temporal processes will differ as a function of an individual's cultural exposure and experience. In this paper we examine the alternative position that some temporal processes may be universal, in the sense that they function in a similar manner irrespective of an individual's cultural exposure and experience. We first review rhythm perception and production studies carried out with adult musicians, adult nonmusicians, children, and infants in order to identify temporal processes that appear to function in a similar fashion irrespective of age, acculturation, and musical training. This review leads to the identification of five temporal processes that we submit as candidates for the status of "temporal universals." For each process, we select the simplest and most representative experimental paradigm that has been used to date. This leads to a research proposal for future intercultural studies that could test the universal nature of these processes.

Humans↗
PubMed2001

Informed consent? A child's right to autonomy.

There is a need for legal clarification of the concept of informed consent in minors. Paediatric nurses need to take a more active role in advocating for the 'Gillick competent' minor. The concept of informed consent continues to provide challenges for practice in paediatric nursing. Informed willing consent in 'Gillick competent' minors requires working effectively in partnership with the child, family and multidisciplinary team.

Child↗
PubMed2000

The development of rhythmic attending in auditory sequences: attunement, referent period, focal attending.

This paper is divided into three sections. The first section is theoretical; it extends Dynamic Attending Theory (Jones, M. R. Psychological Review 83 (1976) 323; Jones, M. R. Perception and Psychophysics 41(6) (1987) 631; Jones, M. R. Psychomusicology 9(2) (1990) 193; Jones, M. R., & Boltz, M. Psychological Review 96(3) (1989) 459) to developmental questions concerning tempo and time hierarchies. Generally Dynamic Attending Theory proposes that, when listening to a complex auditory sequence, listeners spontaneously focus on events occurring at an intermediate rate (the referent level), and they then may shift attention to events occurring over longer or shorter time spans, that is at lower (faster) or higher (slower) hierarchical levels (focal attending). The second section of the paper is experimental. It examines maturational changes of three dynamic attending activities involving referent period and level, attunement, and focal attending. Tasks involve both motor tapping (including spontaneous motor tempo and synchronization with simple sequences and music) and tempo discrimination. We compare performances by 4-, 6-, 8-, and 10-year-old children and adults, with or without musical training. Results indicate three changes with increased age and musical training: (1) a slowing of the mean spontaneous tapping rate (a reflection of the referent period) and mean synchronization rate (a reflection of the referent level), (2) enhanced ability to synchronize tapping and discriminate tempo (improved attunement), and (3) an enlarged range of tapping rates towards slower rates and higher hierarchical levels (improved focal attending). A final section considers results in light of the theory proposed here. It is suggested that growth trends can be expressed in terms of listeners' engagement of slower attending oscillators with age and experience, accompanied by the passage from the initial use of a single oscillator towards the coupling of multiple oscillators.

Adult↗
PubMed2000

Skill acquisition in music performance: relations between planning and temporal control.

We investigated the acquisition of music performance skills in novice and expert pianists. Temporal disruptions in novice performances coincided with constraints in planning capacities. Child and adult pianists ranging in age (9-26 years), training (3-15 years) and sight-reading ability learned to perform a novel musical piece in eleven practice trials. Computer-detected pitch and timing errors revealed: (1) gradual improvements in performance tempo and pitch accuracy with skill level and practice, generally fitting a power function; (2) a relative-timing/pitch accuracy trade-off and high incidence of simultaneous pitch/time errors; (3) improvements in relative timing (temporal continuity, underlying beat, metrical structure) with skill and practice; and (4) increased anticipatory behavior and a greater range of planning with skill and practice. A strong positive relationship between the mastery of temporal constraints and planning abilities within performance suggests that these two cognitive indicators are closely related and may arise from segmentation processes during performance. Examination of sequence timing may explicate planning abilities that underlie many complex skills.

Adolescent↗
PubMed2000

Patients with recognized psychiatric disorders in trauma surgery: incidence, inpatient length of stay, and cost.

BACKGROUND: Although psychiatric disturbances are highly prevalent among traumatically injured inpatients, few investigations have assessed the impact of these disorders on surgical length of stay (LOS) and cost. METHODS: The authors identified all trauma-registry recorded psychiatric diagnoses among patients admitted to University of California Davis Medical Center between January 1993 and December 1996. Linear and logistic regressions were used to assess the unique effects of psychiatric diagnoses on inpatient LOS and cost. RESULTS: A total of 29% of patients had one or more registry-recorded psychiatric diagnosis. Patients with alcohol abuse diagnoses demonstrated 10% to 12% decreases in LOS and cost (p < 0.01), whereas patients with stress disorders, delirium, and psychoses demonstrated 46% to 103% increases in LOS and cost (p < 0.01). CONCLUSION: Patients with recognized psychiatric disorders uniquely impact inpatient trauma surgery LOS and cost. Additional investigations of the processes and outcomes of care could lead to cost-effective performance improvement efforts that target the amelioration of comorbid psychiatric disorders among physically injured trauma survivors.

Adolescent↗