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Biomedical subjects

T Morris

Publications and source records attributed to T Morris.

At least 19 recordsLinked to original sources

Solution structures of apo and holo biotinyl domains from acetyl coenzyme A carboxylase of Escherichia coli determined by triple-resonance nuclear magnetic resonance spectroscopy.

A subgene encoding the 87 C-terminal amino acids of the biotinyl carboxy carrier protein (BCCP) from the acetyl CoA carboxylase of Escherichia coli was overexpressed and the apoprotein biotinylated in vitro. The structures of both the apo and holo forms of the biotinyl domain were determined by means of multidimensional NMR spectroscopy. That of the holo domain was well-defined, except for the 10 N-terminal residues, which form part of the flexible linker between the biotinyl and subunit-binding domains of BCCP. In agreement with X-ray crystallographic studies [Athappilly, F. K., and Hendrickson, W. A. (1995) Structure 3, 1407-1419], the structure comprises a flattened beta-barrel composed of two four-stranded beta-sheets with a 2-fold axis of quasi-symmetry and the biotinyl-lysine residue displayed in an exposed beta-turn on the side of the protein opposite from the N- and C-terminal residues. The biotin group is immobilized on the protein surface, with the ureido ring held down by interactions with a protruding polypeptide "thumb" formed by residues 94-101. However, at the site of carboxylation, no evidence could be found in solution for the predicted hydrogen bond between the main chain O of Thr94 and the ureido HN1'. The structure of the apo domain is essentially identical, although the packing of side chains is more favorable in the holo domain, and this may be reflected in differences in the dynamics of the two forms. The thumb region appears to be lacking in almost all other biotinyl domain sequences, and it may be that the immobilization of the biotinyl-lysine residue in the biotinyl domain of BCCP is an unusual requirement, needed for the catalytic reaction of acetyl CoA carboxylase.

Acetyl-CoA Carboxylase↗

Ballistic shock wave lithotripsy in an 18-year-old thoroughbred gelding.

Prolonged postoperative recuperation time and restricted exercise were circumvented by using ballistic shock wave lithotripsy to break up an 8-cm diameter vesical calculus and by flushing out the sand-like residue under epidural anesthesia with the horse standing. Recovery was uneventful.

Anesthesia, Epidural↗

The evolution of a teledentistry system within the Department of Defense.

Total Dental Access (TDA) is the teledentistry project within the Department of Defense. This project enables referring dentists from the US Armed Forces to consult with specialists on the status of a patient. TDA focuses on three areas of dentistry: patient care, continuing education and dentist-laboratory communications. One of the goals of this project is to increase patient access to quality dental care. The other goal is to establish a cost effective telemedicine system. This paper describes the evolution of a teledentistry system, the main features of POTS-based, ISDN-based and Web-based systems used, advantages, disadvantages and cost-effectiveness of these systems. Data has been collected on the frequency of use, technical problems occurred, avoided patient or specialist travel and the total number of consults. A cost-effectiveness analysis has been conducted on the data collected. The results of this analysis will be presented.

Dentistry↗

Effectiveness of case management with severely and persistently mentally ill people.

This meta-analytic review synthesizes the findings of 24 published studies dealing with the effectiveness of case management with the severely and persistently mentally ill. Summative findings were: (1) Overall, case management interventions are effective--75% of the clients who participate in them do better than the average client who does not; (2) The estimated preventive fraction (e.g., prevention of re-hospitalization) among clients who experience relatively intense case management service (case loads of 15 or less, 89%) is nearly 30% greater than that estimated among similar clients receiving less intensive service; and (3) Various case management practice models did not differ significantly on estimated effectiveness. Important questions concerning the differential effectiveness of case management by specific program, worker, client, and client-worker relationship characteristics remain to be answered.

Case Management↗

A model for enhancing worldwide personal health and wellness.

Individuals must increasingly take control of managing their own health affairs. This requires access to quality information that is not easily obtained from traditional social institutions. NetWellness is an electronic consumer health information service that provides a model for reaching the goal of enhancing personal health and quality of life. [1] We present a vision of consumer health information delivery in the 21st century, and a model for reaching that vision. Our experience to date, progressing through a five-phase model, is aimed at providing the best health information possible to the widest population possible.

Community Participation↗

Mental health. Back from the brink.

Mental healthcare in Wolverhampton had sunk to such depths that two years ago the purchasing authority was openly discussing commissioning its services from another town. Today the situation is transformed. David Jolley and colleagues explain how such marked progress was achieved.

Community Mental Health Services↗

Direct and indirect corticospinal control of arm and hand motoneurons in the squirrel monkey (Saimiri sciureus).

Anatomic evidence suggests that direct corticomotoneuronal (CM) projections to hand motoneurons in the New World squirrel monkey (Saimiri sciureus) are weak or absent, but electrophysiological evidence is lacking. The nature of the corticospinal linkage to these motoneurons was therefore investigated first with the use of transcranial magnetic stimulation (TMS) of the motor cortex under ketamine sedation in five monkeys. TMS produced early responses in hand muscle electromyogram, but thresholds were high (compared with macaque monkey) and the onset latency was variable. Second, stimulation of the pyramidal tract (PT) was carried out with the use of chronically implanted electrodes in ketamine-sedated monkeys; this produced more robust responses that were markedly facilitated by repetitive stimulation, with little decrease in latency on the third compared with the first shock. Finally, postsynaptic potentials were recorded intracellularly from 93 arm and hand motoneurons in five monkeys under general chloralose anesthesia. After a single PT stimulus, the most common response was a small, slowly rising excitatory postsynaptic potential (EPSP), either alone (35 of 93 motoneurons) or followed by an inhibitory postsynaptic potential (39 of 93). The segmental delay of the early EPSPs was within the monosynaptic range (mean 0.85 ms); however, the rise time of these EPSPs was slow (mean 1.3 ms) and their amplitude was small (mean 0.74 mV). These values are significantly slower and smaller than EPSPs in a comparable sample of Old World macaque monkey motoneurons. The results show that CM connections do exist in the squirrel monkey but that they are weak and possibly located on the remote dendrites of the motoneurons. The findings are consistent with earlier anatomic studies. Repetitive PT stimulation produced large, late EPSPs in some motoneurons, suggesting that, in this species, there are relatively strong nonmonosynaptic pathways linking the corticospinal tract to hand motoneurons.

Animals↗

Perceived uncertainty of outcome as a contributing factor in competitive state anxiety.

The Martens, Vealey, and Burton (1990) model of competitive anxiety contains perceived uncertainty, perceived importance, and competitive trait anxiety (A-trait) as key determinants affecting a person's perception of threat and competitive state anxiety (A-state). This experiment tested perceived uncertainty of outcome and A-trait influences on A-state. Club level golfers (N = 72) were assigned to either a low uncertainty condition (LU) or a high uncertainty (HU) condition. In this experiment participants were matched and competed for 12 golf balls in a modified chipping competition. Participants also completed the Competitive State Anxiety Inventory -2 and the Match Orientation Questionnaire (a measure of perceived uncertainty) prior to, and during breaks in the competition. Players alternated in taking four rounds of eight shots from a zone marked approximately 30 metres from the hole. A series of tests did not support the manipulation of uncertainty. This was probably due to likely losers and likely winners not experiencing similar levels of A-state, as Martens et al. assume. Recoding the uncertainty data to reflect levels of confidence, and entering confidence and A-trait into multiple regression equations resulted in these two variables accounting for between 15% and 23% of the A-state variance at different stages of the competition. Recommendations for future research, and possible revisions of the model in light of the present findings are discussed.

Adolescent↗

Psychophysiological stress in elite golfers during practice and competition.

This study examined self-reported state anxiety (cognitive anxiety, somatic anxiety and self-confidence) measured by the Competitive State Anxiety Inventory-2 (CSAI-2; Martens, Vealey, Bump, & Smith, 1990) and physiological responses (salivary cortisol concentration and heart rate) in elite golfers prior to, during and on completion of a tournament and practice round. The relationships between psychophysiological variables were investigated by comparing physiological and psychological responses during competition and practice to each other, and to performance. Performance was determined for each player as the difference between 18 hole score and handicap. Fifteen male Professional Golfing Association (PGA) trainees (aged 21-25 years) competed in a PGA sanctioned tournament and a practice round on the same, or similar golf course. Players completed the CSAI-2 and collected saliva for cortisol analysis on four occasions: prior to tee off, and after completing holes 6, 12 and 18. Cortisol concentration was corrected for circadian variations in cortisol secretion, using baseline cortisol measures. Within-subject analysis revealed elite golfers experienced elevated cortisol, heart rate, cognitive and somatic anxiety, and lower self-confidence during competition compared to practice. For both game conditions, the highest cortisol response was measured prior to the commencement of play, whilst state anxiety measures did not change significantly during the golf rounds. Univariate and multivariate analyses failed to reveal significant correlations between the psychophysiological variables and golf performance. In conclusion, competition and practice were clearly discriminated by the psychophysiological variables, but none of these predicted performance.

Adult↗

Molecular cloning and disease association of hepatitis G virus: a transfusion-transmissible agent.

An RNA virus, designated hepatitis G virus (HGV), was identified from the plasma of a patient with chronic hepatitis. Extension from an immunoreactive complementary DNA clone yielded the entire genome (9392 nucleotides) encoding a polyprotein of 2873 amino acids. The virus is closely related to GB virus C (GBV-C) and distantly related to hepatitis C virus, GBV-A, and GBV-B. HGV was associated with acute and chronic hepatitis. Persistent viremia was detected for up to 9 years in patients with hepatitis. The virus is transfusion-transmissible. It has a global distribution and is present within the volunteer blood donor population in the United States.

Acute Disease↗

Rapid reverse transcription-PCR detection of hepatitis C virus RNA in serum by using the TaqMan fluorogenic detection system.

We describe the application of a new fluorogenic probe-based PCR assay (TaqMan; Perkin Elmer Corp./Applied Biosystems, Foster City, Calif.) for the detection of hepatitis C virus RNA in serum and plasma. This assay allows for the direct direction of specific PCR products within minutes of completion of the PCR by monitoring the increase in fluorescence of a dye-labeled oligonucleotide probe. We evaluated this assay by comparing the results obtained by nested PCR with those obtained by TaqMan PCR. Test samples included two separate dilutions series of plasma samples from experimentally infected chimpanzees and a panel of 48 serum specimens from patients with community-acquired hepatitis C virus. The quantity of HCV RNA in each chimpanzee plasma sample was determined by using branched DNA (bDNA) signal amplification assay (Quantiplex HCV RNA assay; Chiron Corp., Emeryville, Calif.). Both PCR assays demonstrated similar levels of detection and could reliably detect 13 bDNA genome equivalents per sample. We found an overall concordance of 88% between results of two PCR assays with the community-acquired panel, which resolved to 100% when discrepant samples were retested by nested PCR. TaqMan compared favorably with nested PCR with key advantages of speed, increased throughput, and decreased opportunity for false-positive results because of elimination of second-round amplification.

Animals↗

An electronic consumer health library: NetWellness.

NetWellness is a community-based, consumer-defined grant program supporting the delivery of electronic health information to rural residents of southern Ohio and urban and suburban communities in the Greater Cincinnati tri-state region. NetWellness is a collaboratively developed and publicly and privately funded demonstration project. Information is delivered via ISDN, standard dial, dedicated network connections, and the Internet. TriState Online (Greater Cincinnati's Free-Net) and other southern Ohio Free-Nets are key access points in the larger project communities. The other access points are more than forty workstations distributed at public sites throughout the project's primary geographical area. Design strengths and limitations, training initiatives, technical issues, and the project's impact on medical librarianship are examined in this paper. Also discussed are ways of determining community needs and interest, building political alliances, finding and developing funding sources, and overcoming technical obstacles. NetWellness's Internet address is: http:@www.netwellness.org.

Community Participation↗

A pseudoepidemic due to laboratory contamination deciphered by molecular analysis.

OBJECTIVE: A clinical, microbiological, and molecular analysis to identify the source of a cluster of pseudoinfections. DESIGNS: Retrospective analysis of the cases, prospective epidemiologic survey, and laboratory investigation. Molecular analysis of the isolates was performed using pulsed-field gel electrophoresis (PFGE). SETTING: A tertiary Veterans Affairs medical center. PATIENTS: Three patients admitted over a 2-week period with musculoskeletal complaints had one or more joint fluid specimens submitted for culture. In each case, anaerobic chopped meat-glucose broth (CMGB) tubes yielded one or more organisms not typically associated with septic arthritis (Enterobacter cloacae, Enterococcus faecium, Enterococcus casseliflavus, Enterococcus faecalis, Escherichia hermannii, and Pseudomonas diminuti). The first three organisms were isolated from specimens from multiple patients. Two patients had multiple positive cultures; for two patients, separate cultures yielded additional organisms on solid media. RESULTS: Laboratory investigation yielded an isolate of E faecium from 1 of 30 sham-inoculated CMGB tubes. PFGE analysis demonstrated that a single strain of E cloacae was isolated from four CMGB tubes representing all three patients, and a single strain of E faecium was isolated from CMGB tubes representing two patients and the sham-inoculated tube. CONCLUSIONS: The application of molecular typing clearly demonstrated clonality among the isolates and indicated that a common source of contamination, most likely the CMGB tubes, was responsible for these cases.

Adult↗

The effect of prosthetic alignment on relative limb loading in persons with trans-tibial amputation: a preliminary report.

The prosthetic sockets of 14 independent persons with unilateral trans-tibial (BK) amputation were mounted on an adjustable alignment pylon. Vertical ground reaction forces were recorded in neutral prosthetic alignment and in 10 degrees of prosthetic socket varus, valgus, flexion, and extension. Stance phase time, peak vertical ground reaction force, and impulse were all found to be increased on the sound limb when compared to the amputated residual limb. Significant differences were found in stance phase time and peak vertical ground reaction force when comparing malaligned with neutrally aligned prosthetic limbs. Significant differences were also seen in impulse between neutrally aligned and malaligned prosthetic limbs. The results suggest that prosthetic malalignment in persons with trans-tibial amputation leads to increased loading of the contralateral limb.

Adult↗

Incisal overjet as an outcome measure in unilateral cleft lip and palate management.

The Goslon Yardstick is a clinical tool used to rank dental study casts of persons with cleft lip and palate in the late mixed or early permanent dentition into one of five categories. It has been successfully used to investigate the outcomes of the surgical treatment of these anomalies as well as the effects of these deformities on untreated individuals. In this study, 40 study casts ranked by the Goslon Yardstick were digitized using a reflex metrograph. The overjet, overbite, and incisal angulation, and the crossbites of the canines and molars were calculated for each of the sets of casts. Multiple regression analysis was used to determine the predictive value of these variables upon the Goslon scores. The overjet was found to explain 87% of the variance of the Goslon score (p < .0001). No other component had a significant predictive value. The range of overjet associated with the different Goslon scores was calculated from the regression equation. In conclusion, the advantages of using overjet as an indicator of outcome as an alternative to the Goslon Yardstick were discussed.

Child↗