Biomedical subjects

P Gallagher

Publications and source records attributed to P Gallagher.

At least 37 records · Page 2Linked to original sources

PubMed2001

Acute tryptophan depletion in schizophrenia.

BACKGROUND: Brain 5-hydroxytryptamine (5-HT) function is implicated in the pathophysiology of schizophrenia and the action of new generation antipsychotic drugs. By the method of acute tryptophan depletion (ATD) 5-HT can be selectively manipulated. The aim of this study was to examine the effects of ATD on symptoms, mood and cognition in schizophrenic patients. METHODS: Twenty-eight schizophrenic patients participated in a within subject, double-blind, placebo-controlled counterbalanced cross-over study. Patients with a concurrent DSM-IV axis I diagnosis were excluded. Symptoms, mood and cognitive function were evaluated following ATD or ingestion of a control drink. RESULTS: The depleting drink significantly reduced plasma total and free tryptophan. Tryptophan/LNAA ratios did not alter with the administration of the control drink, but differed significantly with ATD; however there was no significant change in tyrosine/LNAA ratio. ATD led to impairment in executive function that was dependent upon the order of administration. Tests of sustained attention, speed of processing, and everyday memory were not affected. No effects were observed on subjective mood ratings, movement disorders or PANSS scores. CONCLUSIONS: Acute tryptophan depletion selectively alters cognition in schizophrenia, but has no effect on symptoms, mood ratings or movement disorders.

Administration, Oral↗

PubMed2001

Preterm infants with paroxysmal supraventricular tachycardia: presentation, response to therapy, and outcome.

OBJECTIVES: We investigated the clinical course of preterm infants with paroxysmal supraventricular tachycardia in comparison to their term counterparts. BACKGROUND: Paroxysmal supraventricular tachycardia (PSVT) is the most common arrhythmia in childhood. It is known to cause significant morbidity and rarely mortality, most commonly in infants. Yet, there is minimal information in the literature on preterm infants with PSVT. METHODS: Retrospective review of 40 infants, 26 term and 14 preterm, less than three months of age who presented with PSVT from January 1990 to January 1999. We compared the severity of first clinical presentation, in-hospital response to long-term medications, and outcome after discharge. RESULTS: Symptomatic severity on presentation was not different between preterm and term infants. Preterm infants required fewer medication trials (p=0.01) and had no recurrences after discharge in contrast with 43 % recurrence in the term infants (p<0.0001). No preterm infants had Wolff-Parkinson-White syndrome (WPW) in contrast to 42 % of term infants (p=0.003). Term infants with WPW were more symptomatic (p=0.01), required more medications (p=0.004), but had a similar recurrence frequency as terms infants without WPW (p=0.95). Excluding infants with WPW, preterm infants were more severely symptomatic (p=0.02), yet no longer was there a difference in response to first medication trial (p=0.30). CONCLUSIONS: We found that preterm infants with PSVT are as severely symptomatic on presentation, require fewer medications for adequate in-hospital control, and have fewer recurrences than their term counterparts. Unexpectedly, preterm infants did not present with WPW. The presence of WPW only in the term infants may account for differences in the clinical course between preterm and term infants.

Anti-Arrhythmia Agents↗

PubMed2001

An evaluation of a standards based portfolio.

In undergraduate and postgraduate nursing studies, the essay type assignment is commonly used to assess student learning. The literature suggests that of the alternatives for the assessment of learning, the use of portfolios may be an effective tool. A portfolio is generally conceptualized as a collection of the students best work or a collection of work that evidences incremental development. For a particular unit of learning, 'Nursing Business', second year undergraduate students in the Bachelor of Nursing programme were required to complete a portfolio. The assessment directed the students to meet specific criteria which in turn reflected the learning outcomes. Therefore the portfolio in this study is more appropriately described as a standards based portfolio (SBP). A SBP is a series of student work that seeks to address pre-determined learning outcomes. This study is an evaluation of student perceptions of a SPB and of interest to the study was the relationship between theory and practice, the availability of resources to complete the assignment and the contribution the portfolio made to the process of learning.

Attitude↗

PubMed2001

An evaluation of a standards based portfolio.

Attitude↗

PubMed2001

Resistance training improves single muscle fiber contractile function in older women.

The purpose of this study was to 1) examine single cell contractile mechanics of skeletal muscle before and after 12 wk of progressive resistance training (PRT) in older women (n = 7; 74 +/- 2 yr) and 2) to compare these results to our previously completed single cell PRT work with older men (n = 7; 74 +/- 2 yr) (Trappe S, Williamson D, Godard M, Porter D, Rowden G, and Costill D. J Applied Physiol 89:143--152, 2000). Knee extensor PRT was performed 3 days/wk at 80% of one-repetition maximum. Muscle biopsies were obtained from the vastus lateralis before and after the PRT. Chemically skinned single muscle fibers (n = 313) were studied at 15 degrees C for peak tension (P(o)), unloaded shortening velocity (V(o)), and power. Due to the low number of hybrid fibers identified post-PRT, direct comparisons were limited to MHC I and IIa fibers. Muscle fiber diameter increased 24% (90 +/- 2 to 112 +/- 6 microm; P < 0.05) in MHC I fibers with no change in MHC IIa fibers. P(o) increased (P < 0.05) 33% in MHC I (0.76 +/- 0.04 to 1.01 +/- 0.09 mN) and 14% in MHC IIa (0.73 +/- 0.04 to 0.83 +/- 0.05 mN) fibers. Muscle fiber V(o) was unaltered in both fiber types with PRT. MHC I and IIa fiber power increased (P < 0.05) 50% [11 +/- 2 to 17 +/- 2 microN. fiber length (FL). s(-1)] and 25% (40 +/- 8 to 51 +/- 6 microN. FL. s(-1)), respectively. However, when peak power was normalized to cell size, no pre- to postimprovements were observed. These data indicate that PRT in elderly women increases muscle cell size, strength, and peak power in both slow and fast muscle fibers, which was similar to the older men. However, in contrast to the older men, no change in fiber V(o) or normalized power was observed in the older women. These data suggest that older men and women respond differently at the muscle cell level to the same resistance-training stimulus.

Aged↗

PubMed2000

Phosphorylation of myosin light chain kinase by p21-activated kinase PAK2.

Phosphorylation of myosin II regulatory light chains (RLC) by Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK) is a critical step in the initiation of smooth muscle and non-muscle cell contraction. Post-translational modifications to MLCK down-regulate enzyme activity, suppressing RLC phosphorylation, myosin II activation, and tension development. Here we report that PAK2, a member of the Rho family of GTPase-dependent kinases, regulates isometric tension development and myosin II RLC phosphorylation in saponin permeabilized endothelial monolayers. PAK2 blunts tension development by 75% while inhibiting diphosphorylation of myosin II RLC. Cdc42-activated placenta and recombinant, constitutively active PAK2 phosphorylate MLCK in vitro with a stoichiometry of 1.71 +/- 0. 21 mol of PO(4)/mol of MLCK. This phosphorylation inhibits MLCK phosphorylation of myosin II RLC. PAK2 catalyzes MLCK phosphorylation on serine residues 439 and 991. Binding calmodulin to MLCK blocks phosphorylation of Ser-991 by PAK2. These results demonstrate that PAK2 can directly phosphorylate MLCK, inhibiting its activity and limiting the development of isometric tension.

Calcium↗

PubMed2000

Reduction in pain associated with open carpal tunnel decompression.

Patients treated by open carpal tunnel decompression under local anaesthetic experience significant pain with the introduction of local anaesthetic before operation. A prospective double-blind randomized placebo controlled trial was carried out to assess whether this pain could be reduced with the pre-application of a topical lignocaine-prilocaine anaesthetic cream. Nineteen patients undergoing simultaneous bilateral operations were studied. Pain, measured with a visual analogue scale, was significantly reduced on the sides treated with anaesthetic cream. On a four point verbal scale the rating on the placebo side was "moderate" or "severe", compared to "mild" on the anaesthetic cream side. The reduction in pain was greater in women, possibly due to a relatively thinner dermis. There were no adverse effects.

Anesthetics, Local↗

PubMed2000

The treatment of scaphoid nonunion. A review of a novel technique using precision bone grafting compared with Herbert screw fixation and bone graft.

We have retrospectively reviewed the results of 40 consecutive patients with nonunion of the scaphoid treated by the senior author (PG) between 1993 and 1996. These comprised two groups of patients. Group 1 comprised 20 patients treated between 1993 and 1994, with a Herbert screw and autograft, and Group 2, which also comprised 20 patients treated with the precision bone grafting technique which we describe. The precision bone grafting technique employs simple instrumentation to harvest bone percutaneously from the iliac crest and then insert it at the scaphoid nonunion site. The evaluation consisted of a clinical and radiological assessment of union and wrist function. Our review demonstrates a higher rate of union with the precision bone grafting technique than by the Herbert screw fixation with bone grafting.

Adult↗

PubMed2000

Metabolic response during sport rock climbing and the effects of active versus passive recovery.

The objectives of this study were to 1) continuously assess oxygen uptake during and after difficult sport rock climbing and 2) to evaluate the effects of active versus passive recovery on post-climbing blood lactate and hand grip strength. Fifteen expert rock climbers attempted to climb (i.e., red point lead) a 20 m difficult route (5.12 b, YDS scale) set on an indoor climbing wall. Subjects were assigned to either active recovery (AR; n = 8), consisting of recumbent cycling at 25 Watts, or passive recovery (PR; n = 7). Expired air was analyzed during climbing and through a 10-minute recovery period by a lightweight battery-powered open circuit system. Oxygen uptake (VO2) and heart rate (HR) were measured continuously and averaged over 20-second intervals. These data were expressed as averages over the entire climb (VO2avg and HRavg) and as peak values. An estimated resting VO2 of 250 ml x min(-1) was subtracted from the interval VO2 values to provide net VO2 data which were subsequently converted to absolute VO2 values in liters for climbing (C - VO2net) and recovery (R - VO2net). Total net VO2 was calculated as the sum of C - VO2net plus R - VO2net. Blood samples were obtained via fingerprick at pre-climb and at 1-, 10-, 20-, and 30-minutes post-climb and analyzed for whole blood lactate. Handgrip strength was measured via dynamometry at pre-climb and at 1-, 10-, 20-, and 30-minutes post-climb. Mean climbing time was 2.57 +/- 0.41 min. During climbing, VO2avg and HRavg means were 1660 +/- 340 ml x min(-1) and 148 +/- 16 b x min(-1) respectively with mean peaks of 2147 +/- 413 ml x min(-1) and 162 +/- 17 b x min(-1). Relative VO2avg was 24.7 +/- 4.3 ml x kg(-1) x min(-1) with a mean peak value of 31.9 +/- 5.3 ml x kg(-1) x min(-1). Mean values for C - VO2net and R - VO2net were 4.009 +/- 0.929 L and 2.809 +/- 0.518 L respectively for the PR group with mean total net VO2 at 6.818 +/- 1.291 L. For the AR group mean values for C - VO2net and R - VO2net were 4.216 +/- 1.174 L and 7.691 +/- 3.154 L respectively with a mean total net VO2 of 11.906 +/- 4.172 L. There was no difference between the groups for C - VO2net, however R - VO2net and total net VO2 were significantly different (p < 0.05) between PR and AR. Blood lactate increased significantly with climbing in both AR and PR groups. Lactate remained elevated in the PR group until 30 minutes post-climb, but had returned to pre-climb level by 20 minutes in the AR group. Handgrip strength was significantly decreased at 1-minute post-climb for the AR group, but was not significantly changed for the PR group. Although climbers may be able to attain a plateau in VO2, the observed accumulation of lactate in the blood combined with the elevated recovery VO2 indicate a higher overall energy demand than indicated via the recorded VO2 during climbing. Low intensity active recovery appears to significantly reduce accumulated blood lactate within 20 minutes following difficult climbing, however further research is required to establish whether this strategy is advantageous for subsequent climbing performance.

Adult↗

PubMed2000

Positive meaning in amputation and thoughts about the amputated limb.

The majority of research conducted on the aftermath of amputation understandably concerns itself with its most distressing aspects. This research aimed to explore whether and how people think about their amputated limb, and whether and if they considered anything good had emerged from their amputation. One hundred and four (104) people completed the Trinity Amputation and Prosthesis Experience Scales (TAPES) and two open-ended questions. The majority of participants were young and had traumatic amputations. Fifty-six percent (56%) of people thought about their amputated limb. People with bilateral or a trans-femoral amputation were more likely to think about their amputated limb than people with a trans-tibial amputation. Forty-eight percent (48%) considered that something good had happened as a result of the amputation. Furthermore, finding positive meaning was significantly associated with more favourable physical capabilities and health ratings, lower levels of Athletic Activity Restriction and higher levels of Adjustment to Limitation. Future research and clinical implications are discussed.

Adaptation, Psychological↗

PubMed1999

Double gloving and a glove perforation indication system during the dental treatment of HIV-positive patients: are they necessary?

AIM: The aim of this study was to compare the incidence of glove perforation when double gloved or single gloved during the routine treatment of HIV-positive patients. In addition, a glove perforation indication system based on a double gloving technique was assessed. DESIGN: Prospective, randomised and open study of glove perforation. METHODS: 138 consecutive HIV-positive patients underwent routine dental treatment by senior dental staff and dental hygienists in a teaching hospital. Staff wore either single gloves (Regent Biogel D or standard surgical gloves) or double gloves (Regent 'Reveal' perforation indication system or standard surgical gloves). A subjective assessment of glove comfort, sensitivity and ease of donning was made using a visual analogue scale. RESULTS: The incidence of glove perforation/procedure was low, 2.9%. There were no skin penetrating injuries, visible exposure to body fluids or unnoticed perforations. Double gloving was subjectively less comfortable and sensitive than single gloving (P < 0.0001). The glove perforation indication system did not increase the detection of intra-operative perforations. CONCLUSIONS: There is unlikely to be any significant benefit from the use of a double gloving technique or perforation indication system during the routine dental treatment of HIV-positive patients.

Dental Care for Chronically Ill↗

PubMed1999

Elevated blood lead levels in children are associated with lower erythropoietin concentrations.

Eighty-six children (mean age, 34 months) were studied to determine whether elevated blood lead levels in children are associated with lower erythropoietin concentrations. The median erythropoietin concentration was 5.9 mIU/mL (range, 2.3 to 11.5 mIU/mL), and the median blood lead level was 0.87 micromol/L (18 microg/dL; range, 2 to 84 microg/dL). Blood lead concentration was inversely and independently related to erythropoietin concentration.

Analysis of Variance↗

PubMed1999

Psychological adjustment and coping in adults with prosthetic limbs.

The potential mediating effects of different coping strategies on the adjustment to living with a prosthetic limb were investigated in 44 adult amputees. Participants completed a questionnaire inquiring about coping, pain, emotional well-being, demographics, and disability-related variables. The coping strategy adopted and the extent of the adjustment to the prosthetic limb varied with age, site of limb loss, and cause of amputation. Furthermore, coping style mediated the adjustment to wearing a prosthetic limb. The results are discussed in terms of future applications and research.

Adaptation, Psychological↗

PubMed1999

Small-angle x-ray scattering study of kinetics of spinodal decomposition in N-isopropylacrylamide gels.

We present synchrotron-based time-resolved small-angle x-ray scattering (SAXS) measurements of spinodal decomposition in a covalently cross-linked N-isopropylacrylamide gel. The range of wave numbers examined is well beyond the position of the maximum in the structure factor S(q,t). The equilibrium structure factor is described by the sum of a Lorentzian and a Gaussian. Following a temperature jump into the two phase region, the scattered intensity increases with time and eventually saturates. For early times the linear Cahn-Hilliard-Cook (CHC) theory can be used to describe the time evolution of the scattered intensity. From this analysis we found that the growth rate R(q) is linearly dependent on q(2), in agreement with mean-field theoretical predictions. However the Onsager transport coefficient Lambda(q) approximately q(-4), which is stronger than the q dependence predicted by the mean-field theory. We found that the growth rate R(q)>0, even though the wave numbers q probed by SAXS are greater than sqrt[2]q(m) where q(m) is the position of the peak of S(q,t), also in agreement with the mean-field predictions for a deep quench. We have also examined the range of validity of the linear CHC theory, and found that its breakdown occurs earlier at higher wave numbers. At later times, a pinning of the structure was observed. The relaxation to a final, microphase-separated morphology is faster and occurs earlier at the highest wave numbers, which probe length scales comparable to the average distance between crosslinks.

Journal Article↗

PubMed1999

Validity of the MMPI-2 and Beck Depression Inventory for making decisions of organ allocation in renal transplantation.

Psychosocial factors are presented which affect clinical decision-making regarding the allocation of renal organs. Patients were rated as being either High Risk or Low Risk transplant candidates. High Risk candidates were scored as being significantly different from the Low Risk candidates on many psychosocial variables. Interestingly, significant differences were not found between these two groups on either the MMPI-2 or the Beck Depression Inventory. The validity of using information from these inventories to allocate organs is discussed.

Attitude to Health↗

PubMed1999

Metabolic and cardiovascular responses during work on a high ropes course.

BACKGROUND: High ropes course facilities are employed in adventure programs to promote self-esteem, stress management, and problem-solving skill development. Although the combination of fear, anxiety, and potentially high levels of physical exertion during such activity could yield situations of cardiac risk for certain individuals, no previous research has described the physiological nature of high ropes course work. The purpose of this study was to observe the metabolic and cardiovascular responses to a typical high ropes course experience. METHODS: Seventeen subjects gave informed consent to complete a 5-element sequence on an indoor high ropes course. The elements included step-swings (SS), swinging tires (ST), a 4-inch balance beam (B1), a vertical cargo net (CN), and a second beam (B2). These elements were positioned in series at a height of 20 feet above the floor. Expired air was analyzed continuously using a portable open circuit metabolic analyzer and heart rate (HR) was recorded at 5-second intervals via telemetry. Pre- and postcourse blood samples were obtained via finger-prick and analyzed for lactate (BL). Systolic (SBP) and diastolic (DBP) blood pressures were taken at an orientation session prior to each subject's test date and at pre-, mid-, and post course points during each test session. RESULTS: The mean ropes course work time was 11.2 +/- 2.9 min. Mean averaged/peak oxygen uptake (VO2), ventilation (VE), HR, and energy expenditure (EE) were 13.9 +/- 2.3/21.6 +/- 3.7 ml.kg-1.min-1, 36.4 +/- 8.1/49.6 +/- 10.3 l.min-1, 142 +/- 16/167 +/- 15 b.min-1, and 5.1 +/- 0.9/7.7 +/- 1.0 kcal.min-1 respectively. In descending order, mean EE was 6.2 +/- 1.1, 6.2 +/- 0.8, 5.4 +/- 1.0, 4.5 +/- 0.5, and 4.2 +/- 0.5 kcal +/- min-1 for the B2, ST, CN, B1, and SS elements respectively. Blood lactate increased (p < 0.05) from a pre course value of 1.9 +/- 0.6 mmol.l-1 to 5.0 +/- 1.1 mmol.l-1 post course. SBP values at pre- (136.7 +/- 16.0), mid-(169.8 +/- 19.7), and postcourse (154.1 +/- 19.2) were higher (p < 0.05) than the orientation SBP of 126.2 +/- 14.7 mmHg. Mid- and post course SBP means were significantly higher than the precourse mean. A significant difference was found for DBP between the midcourse (86.3 +/- 8.9) vs the orientation mean (79.1 +/- 6.8) only. CONCLUSIONS: Based upon the results of this study, average high ropes course work can be classified as aerobically moderate to heavy, at just over 4 METs with peak periods over 7 METs. Transient elevation in DBP may occur during elements with a high level of upper body work. High ropes course work does not present an unusually high physiological stress for healthy, physically fit individuals.

Adult↗

PubMed1998

Chronic active destructive herpes simplex encephalitis with recovery of viral DNA 12 years after disease onset.

Acute herpes simplex encephalitis (HSE) carries significant morbidity and mortality even after early treatment with antiviral agents (7). As well as causing acute neurological disease, Herpes viruses are associated with relapsing--remitting (Varicella--Zoster, Epstein-Barr) and chronic (Rasmussen encephalitis) disease processes (1). A two-year-old girl developed acute HSE which was followed by a 10-year neurologic illness characterised by asymmetric spastic tetraparesis, pseudobulbar palsy, the opercular syndrome of Foix-Chavany-Marie (4) and seizures. The neurological signs remained static until the child died suddenly 12 years after disease onset. Neuropathologic examination demonstrated active chronic encephalitis. Herpes simplex virus (HSV) DNA was recovered from formalin-fixed paraffin-embedded brain tissue. This case provides additional evidence for the development of chronic neurological disease attributable to persistence of herpes simplex virus type 1.

Brain↗

PubMed1998

Proving the competence of nurses.

Registration in itself is no guarantee that a nurse is competent to practise. A system of competence-based pracitising certificates linked with registration would raise the professionalism of nursing and assure the public it was receiving competent, safe nursing care.

Certification↗