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M West

Publications and source records attributed to M West.

At least 91 records · Page 5Linked to original sources
PubMed1996

No loss of hippocampal hilar somatostatinergic neurons after repeated electroconvulsive shock: a combined stereological and in situ hybridization study.

Electrically induced seizures with anesthesia and muscle relaxation (ECT) is commonly used in the therapy of psychotic depression in humans. Unmodified electroshock (ECS) is used as a model for epilepsy in the rat. In several seizure models of epilepsy, in particular the dentate hilar somatostatin-containing (SSergic) neurons have been found to undergo degeneration. To assess the potential loss of SSergic hilar neurons after repeated ECS, 10 rats were given 110 ECS, one per day, 5 days a week. One day after the last ECS the rats were anesthesized, perfused, the brains cut on a vibratome and prepared for nonradioactive in situ hybridization for somatostatin along with five control rats. Like rats given 10-36 ECS in earlier studies, the ECS-treated rats displayed a markedly increased neuronal hybridization labeling when compared with control rats. The total number of dentate hilar SSergic neurons of each rat was estimated using the optical disector technique. The mean number of hilar SSergic neurons in the ECS-treated rats was 12,785, compared to 12,392 in the control rats. The total number of hilar SSergic neurons in ECS-treated versus control rats was not significantly different (Student's t test; t value = .35; p = .74). We conclude that repeated ECS treatment does not cause loss of hilar SSergic neurons.

Animals↗
PubMed1996

Photolyase of Myxococcus xanthus, a Gram-negative eubacterium, is more similar to photolyases found in Archaea and "higher" eukaryotes than to photolyases of other eubacteria.

We report the identification of the gene encoding a DNA photolyase (phrA) from the Gram-negative eubacterium Myxococcus xanthus. The deduced amino acid sequence of M. xanthus photolyase indicates that the protein contains 401 amino acids (Mr 45,071). By comparison of the amino acid and DNA sequences with those of other known photolyases, it has been found that it is more similar to the deduced amino acid sequences of the photolyases of "higher" eukaryotes than to the photolyases of other eubacteria. Recombinant plasmids carrying M. xanthus phrA rescue the photoreactivation activity of an irradiated strain of Escherichia coli with a deletion in phrA. This rescue is light-dependent.

Amino Acid Sequence↗
PubMed1996

Periodontoid synovial cyst causing cervico-medullary compression.

BACKGROUND: Periodontoid synovial cysts are rare lesions which may produce symptomatic cervico-medullary compression. METHOD: We report such a patient, whose progressive neurological deterioration required surgical treatment by transoral odontoidectomy and decompression. RESULTS: The diagnostic and theraputic interventions are described, including a lumbar puncture which precipitated a transient loss of consciousness and respiratory arrest. Surgery achieved clinical improvement, without complications or need for operative stablization. Detailed neuropathology is presented, as well as a literature review. CONCLUSION: Appropriate neuroradiological assessment is required in patients with suspected cervico-medullary compression, and symptomatic periodontoid synovial cysts may respond well to transoral surgical decompression.

Cervical Vertebrae↗
PubMed1996

Attachment organization and history of suicidal behavior in clinical adolescents.

One hundred thirty-three adolescents in psychiatric treatment participated in a case-comparison study investigating the association of attachment patterns with a history of suicidal behaviors. The comparison group comprised 64 adolescents who had never experienced suicidal ideation or behaviors; the case group included 69 adolescents with histories of suicidal behavior (n = 53) and severe suicidal ideation (n =16). Attachment patterns were assessed using the Adult Attachment Interview. In accordance with definitions provided in the scoring system, 86% of case and 78% of comparison adolescents in psychiatric treatment had experienced attachment-related trauma. Lapses in the monitoring of reasoning or discourse occurred during the attempted discussion of these events in 73% of adolescents in the case group but in only 44% of adolescents in the clinical comparison group (p = .002), suggesting that cognitive disorganization may be an important variable mediating between traumatic experience and suicidal behavior. Female adolescents and older adolescents were significantly more likely than other adolescents to be in the case group. Preoccupied attachment, in interaction with unresolved-disorganized attachment, was associated with the case group, whereas dismissing attachment was associated with the comparison group.

Adolescent↗
PubMed1996

Economic appraisal of maintenance parenteral iron administration in treatment of anaemia in chronic haemodialysis patients.

BACKGROUND: Iron deficiency is common in haemodialysis patients and adequate supplementation by the oral or parenteral route has been limited by drug side-effects, absorption, and cost. Intermittent doses of intravenous iron dextran complex are recommended in patients with inadequate iron stores despite maximal tolerated oral dose. We conducted a prospective study with economic analysis of a regular maintenance intravenous iron regimen in this group of patients. METHODS: Fifty patients comprising one-half of our haemodialysis population required intravenous iron treatment, i.e. they failed to achieve an arbitrary goal serum ferritin 100 microg/l despite maximal tolerated oral iron dose. After a loading dose of intravenous iron dextran complex (IV-FeD) based on Van Wyck's nomogram (400+/-300 mg) they received a maintenance dose of 100mg IV-FeD once every 2 weeks. Initial goal serum ferritin was set at 100-200 microg/l. If no increase in haemoglobin was achieved at this level, transferrin saturation was measured to assess bioavailable iron, and when less than 20%, goal serum ferritin was increased to 200-300 microg/l. Recombinant human erythropoietin (rHuEpo) was used where needed to maintain haemoglobin in the 9.5-10.5 g/l range only if ferritin requirements were met. Results. Mean haemoglobin rose from 87.7+/-12.1 to 100.3+/-13.1 g/l (P<0.001, Cl 7.7-17.9) at mean follow-up of 6 months (range 3-15 months). In patients on rHuEpo, dose per patient was reduced from 96+/-59 u/kg per week to 63+/-41 u/kg per week, representing a 35% dose reduction (P<0.05, Cl 1-65). An annual cost reduction of $3166 CDN was projected; however, in the first year this is offset by the cost of the loading dose of IV-FeD required at the beginning of treatment. No adverse reactions were encountered. CONCLUSION: Iron deficiency is very common in our haemodialysis population, especially in those patients receiving rHuEpo. A carefully monitored regimen of maintenance parenteral iron is a safe, effective, and economically favourable means of iron supplementation in patients with insufficient iron stores on maximum tolerated oral supplements.

Adult↗
PubMed1996

Transport and epithelial secretion of the cardiac glycoside, digoxin, by human intestinal epithelial (Caco-2) cells.

1. Human intestinal epithelial Caco-2 cells have been used to investigate the transepithelial permeation of the cardiac glycoside, digoxin. 2. Transepithelial basal to apical [3H]-digoxin flux exceeds apical to basal flux, a net secretion of [3H]-digoxin being observed. At 200 microM digoxin, net secretory flux (Jnet) was 10.8 +/- 0.6 nmol cm-2 h-1. Maximal secretory flux (Jmax) of vinblastine was 1.3 +/- 0.1 nmol cm-2 h-1. Cellular uptake of digoxin was different across apical and basal cell boundaries. It was greatest across the basal surface at 1 microM, whereas at 200 microM, apical uptake exceeded basal uptake. 3. Net secretion of [3H]-digoxin was subject to inhibition by digitoxin and bufalin but was not inhibited by ouabain, convallatoxin, and strophanthidin (all 100 microM). Inhibition was due to both a decrease in Jb-a and an increase in Ja-b. Uptake of [3H]-digoxin at the apical surface was increased by digitoxin and bufalin. All cardiac glycosides decreased [3H]-digoxin uptake at the basal cell surface (except for 100 microM digitoxin). 4. The competitive P-glycoprotein inhibitors, verapamil (100 microM), nifedipine (50 microM) and vinblastine (50 microM) all abolished net secretion of [3H]-digoxin due to both a decrease in Jb-a and an increase in Ja-b. Cellular accumulation of [3H]-digoxin was also increased across both the apical and basal cell surfaces. I-Chloro-2,4,-dinitrobenzene (10 microM), a substrate for glutathione-S-transferase and subsequent ATP-dependent glutathione-S-conjugate secretion, failed to inhibit net secretion of [3H]-digoxin. The increase in absorptive permeability Pa-b (= Ja-b/Ca) and cellular [3H]-digoxin uptake upon P-glycoprotein inhibition, showed that the intestinal epithelium was rendered effectively impermeable by ATP-dependent extrusion at the apical surface. 5. A model for [3H]-digoxin secretion by the intestinal epithelium is likely to involve both diffusional uptake and Na(+)-K+ pump-mediated endocytosis, followed by active extrusion at the apical membrane.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Chronic regulation of transepithelial Na+ transport by the rate of apical Na+ entry.

In several settings in vivo, prolonged inhibition of apical Na+ entry reduces and prolonged stimulation of apical entry enhances the ability of renal epithelial cells to reabsorb Na+, an important feature of the load-dependent regulation of renal tubular Na+ transport. To model this load dependency, apical Na+ entry was inhibited or stimulated for 18 h in A6 cells and vectorial transport was measured as short-circuit current (Isc) across monolayers on filter-bottom structures. Basal amiloride-sensitive Isc represents the activity of apical Na+ channels, whereas Isc after permeabilization of the apical membrane to cations with nystatin represents maximal activity of the basolateral Na(+)-K(+)-ATPase. Chronic inhibition of apical Na+ entry by 18-h apical exposure to amiloride or replacement of apical Na+ with tetramethylammonium (TMA+), followed by washing and restoration of normal apical medium, revealed a persistent decrease in Isc that remained despite exposure to nystatin. Both basal and nystatin-stimulated Isc recovered progressively after restoration of normal apical medium. In contrast, chronic stimulation of apical Na+ entry by short circuiting the epithelium increased Isc in the absence and presence of nystatin, indicating upregulation of both apical Na+ channels and basolateral Na(+)-K(+)-ATPase. Basolateral equilibrium [3H]ouabain binding was reduced to 67 +/- 5% in TMA+ vs. control cells, whereas values in 18-h short-circuited cells increased by 42 +/- 19%. The results demonstrate that load dependency of tubular Na+ transport can be modeled in vitro and indicate that the regulation of Na(+)-K(+)-ATPase observed in these studies occurs in part by changes in the density of functional transporter proteins within the basolateral membrane.

Amiloride↗
PubMed1996

Stress, coping and burnout in mental health nurses: findings from three research studies.

In this paper we present data from three research studies on stress, coping and burnout in mental health nurses. All three studies used a range of self report questionnaires. Measures included a demographic checklist, the General Health Questionnaire (GHQ-28), the Maslach Burnout Inventory, the DCL Stress Scale and the Cooper Coping Skills Scale. In all, 648 ward based mental health nurses were surveyed. There were no significant differences between levels of psychological distress on GHQ Total Score, but there were differences in caseness rates. In Study 3, some 38% of nurses were found to score at or above the criterion for caseness. The main stressors for ward staff were to do with staff shortages, health service changes, poor morale and not being notified of changes before they occurred. Differences in coping skills were found across studies. The study group with the highest stress scores also had the lowest coping skills scores. This was also associated with significantly higher alcohol consumption and greater self reported sickness absence. Scores on the Maslach Burnout Inventory showed higher levels of burnout amongst nurses in Study 3. These three studies have confirmed that stress is a problem for ward based mental health nurses. Two main implications arise from this work. Firstly we need models of the stress process that are empirically based, and which help us identify the moderating variables that reduce the impact of stressors on nurses. Secondly, we need to utilise this knowledge to deliver stress management interventions for staff. We end by outlining a model which may help us both understand the process of stress causation, and move towards our goal of stress reduction.

Adaptation, Psychological↗
PubMed1996

Practical Bayesian inference using mixtures of mixtures.

Discrete mixtures of normal distributions are widely used in modeling amplitude fluctuations of electrical potentials at synapses of human and other animal nervous systems. The usual framework has independent data values yj arising as yj = mu j + xn0 + j, where the means mu j come from some discrete prior G(mu) and the unknown xno + j's and observed xj, j = 1,...,n0, are Gaussian noise terms. A practically important development of the associated statistical methods is the issue of nonnormality of the noise terms, often the norm rather than the exception in the neurological context. We have recently developed models, based on convolutions of Dirichlet process mixtures, for such problems. Explicitly, we model the noise data values xj as arising from a Dirichlet process mixture of normals, in addition to modeling the location prior G(mu) as a Dirichlet process itself. This induces a Dirichlet mixture of mixtures of normals, whose analysis may be developed using Gibbs sampling techniques. We discuss these models and their analysis, and illustrate them in the context of neurological response analysis.

Animals↗
PubMed1995

Haemodynamic instability and myocardial ischaemia during carotid endarterectomy: a comparison of propofol and isoflurane.

The purpose of this study was to compare two anaesthetic protocols for haemodynamic instability (heart rate (HR) or mean arterial pressure (MAP) < 80 or > 120% of ward baseline values) measured at one-minute intervals during carotid endarterectomy (CEA). One group received propofol/alfentanil (Group Prop; n = 14) and the other isoflurane/alfentanil (Group Iso; n = 13). Periods of haemodynamic instability were correlated to episodes of myocardial ischaemia as assessed by Holter monitoring (begun the evening before surgery and ceasing the morning of the first postoperative day). In Group Prop, anaesthesia was induced with alfentanil 30 micrograms.kg-1 i.v., propofol up to 1.5 mg.kg-1 and vecuronium 0.15 mg.kg-1, and maintained with infusions of propofol at 3-12 mg.kg-1.hr-1 and alfentanil at 30 micrograms.kg-1.hr-1. In Group Iso, anaesthesia was induced with alfentanil and vecuronium as above, thiopentone up to 4 mg.kg-1 and maintained with isoflurane and alfentanil infusion. Phenylephrine was infused to support MAP at 110 +/- 10% of ward values during cross-clamp of the internal carotid artery (ICA) in both groups. Emergence hypertension and/or tachycardia was treated with labetalol, diazoxide or propranolol. Myocardial ischaemia was defined as ST-segment depression of > or = 1 mm (60 msec past the J-point) persisting for > or = one minute. For the entire anaesthetic course (induction to post-emergence), there was no difference between groups for either duration or magnitude outside the < 80 or > 120% range for HR or MAP. However, when the period of emergence from anaesthesia (reversal of neuromuscular blockade to post-extubation) was assessed, more patients were hypertensive (P = 0.004) and required vasodilator therapy in Group Iso (10/13 vs 5/14; P = 0.038 Fisher's Exact Test). The mean dose of labetalol was greater in Group Iso (P = 0.035). No patient demonstrated myocardial ischaemia during ICA cross-clamp. On emergence, 6/13 patients in Group Iso demonstrated myocardial ischaemia compared with 1/14 in Group Prop (P = 0.029). Therefore, supporting the blood pressure with phenylephrine, during the period of ICA cross-clamping, appears to be safe as we did not observe any myocardial ischaemia at this time. During emergence from anaesthesia, haemodynamic instability was associated with myocardial ischaemia. Under these specific experimental conditions, with emergence, hypertension and myocardial ischaemia were more prevalent with more frequent pharmacological interventions in patients receiving isoflurane.

Aged↗
PubMed1995

Helping to solve problems associated with spina bifida: 1. Presentation of the TRS Project: organizing services for low frequency diagnostic groups and 2. Cognitive deficits often seen in young adults with spina bifida: effects in the school and work place.

1. A Presentation of the TRS Project: Counselling and (Re)habilitation Center. A Model Project in Organizing Services for Low Frequency Diagnostic Groups. Persons with low frequency disabilities often require services from a number of professions. The patient organizations claim that the patients themselves often have to coordinate their own treatment. The TRS project has been established as one of the initiatives under the Norwegian Government's Plan of Action for the Disabled. The project is one of three national projects designed to develop models for the coordination of services for persons with low frequency congenital disabilities. The TRS project deals with the following five diagnoses: Marfan syndrome, arthrogryphosis multiplex congenita, myelomeningocele/spina bifida, osteogenesis imperfecta and congenital limb deficiency. The project is based on patient (user) participation. The five patient organizations are represented on the board where they are in the majority. Patients along with professionals give lectures during group stays. The project offers its services to persons with the diagnosis from all parts of Norway (4.3 mill. inhabitants). Persons with spina bifida over 16 years are included in the project, as well as persons with the other diagnoses at all ages. We present the organization of the project and the repertoire of services that are on offer. 2. Cognitive Deficits Often Seen in Young Adults with Spina Bifida: Effects in the School and Work Place. As survival rates continue to increase with the use of shunting procedures for persons with spina bifida (SB), the need for improved educational and vocational planning also increases. Orbeck and Schanke reported that the cognitive deficits of young adults with SB have not received enough attention in educational and vocational planning. A thorough description of these deficits will aid in developing more effective individualized planning. With improved planning, insight into alternative methods for improving support may also then be investigated. The purpose of this study is to better define and describe the cognitive deficits often encountered while planning support in the school and work place for this group. Neuropsychological examinations are the basis for this description of observed cognitive deficits. The study included 46 young adults with SB aged 15 to 38 living in Norway. All persons were given a neuropsychological test battery which included tests for attention, memory, speed of information processing, visual perception and visual constructive function, arithmetic, fine motor coordination, and verbal functioning. The results indicated deficits in fine motor coordination, speed of information processing, and a slow learning curve. The consequences of these deficits in educational and vocational planning are discussed and guidelines for further studies are suggested.

Abnormalities, Multiple↗
PubMed1995

Clean intermittent catheterization: safe, cost-effective bladder management for male residents of VA nursing homes.

OBJECTIVES: To compare the safety and cost of clean versus sterile intermittent bladder catheterization in male nursing home residents. To provide evidence to support the hypothesis that intermittent catheterization is a valid, alternative method of bladder management in male residents of long-term care in whom urinary retention is a documented problem. DESIGN: Randomized clinical trial. SETTING: Three long-term care sites having predominantly male populations. PARTICIPANTS: Eighty male veterans, residents of three long-term care facilities, ranging in age from 36 to 96 years with a mean age of 72. INTERVENTIONS: Standardized procedures for clean and sterile intermittent catheterization (IC) were implemented by staff nurses at each site. Patients were randomized into clean and sterile IC groups. Nursing time and catheterization equipment usage were recorded using bar code readers. Clinical data were collected from the medical chart. Treatment of urinary tract infection was prescribed by the medical personnel responsible for each individual resident. MEASUREMENTS: We compared the number of treatment episodes for symptomatic bacteriuria between groups randomized to receive either clean or sterile intermittent catheterization. Laboratory analysis of blood and urine was done on predetermined days. Control variables were research site and patient history of urinary tract infection within the last 6 months. A cost comparison of nursing time and equipment usage for the two catheterization techniques was also performed. RESULTS: No significant differences were found between clean and sterile groups with regard to number of treatment episodes, time to first infection, type of organism cultured, or cost of antibiotic treatment. The cost of sterile technique was considerably higher both in terms of nursing time and supplies. CONCLUSIONS: Findings from this study demonstrate that clean technique intermittent catheterization is a safe and cost-effective bladder management technique with male, nursing home residents, despite the frailty of this high risk population. An annual savings of approximately $1460 per patient in nursing time and catheterization supplies could be anticipated if a patient were catheterized an average of four times per day substituting clean IC technique for sterile IC technique.

Adult↗
PubMed1995

One hundred and ten sports related facial fractures.

In a 1 year period (1993) 332 facial fractures were treated in Cork Regional Hospital. Of these 110 (33%) were sports related. Males accounted for 94.5% of patients and 77% of patients were aged below 30 years. Nasal fractures were the most common fractures seen (56%). Almost half (49%) of sports related facial fractures occurred while playing Gaelic games. The incidence of hurling fractures has been more than halved over the last 20 years. Seventy eight percent of patients required operative treatment.

Adolescent↗
PubMed1995

Interpersonal disorder in schizoid and avoidant personality disorders: an attachment perspective.

OBJECTIVE: To investigate the characteristics related to avoidant attachment of 13 schizoid/avoidant psychiatric outpatients and 20 nonschizoid/avoidant psychiatric outpatients. METHOD: Three scales ("maintains distance in relationships", "high priority on self-sufficiency" and "attachment relationship is a threat to security") differentiated schizoid and avoidant personality disordered patients from other personality disordered patients. RESULTS: The results are discussed in terms of the attachment and DSM diagnostic models of avoidant styles in relationships. CONCLUSION: The 2 groups of schizoid and avoidant personality disordered patients were not significantly different on the desire for close affectional bonds scale.

Adult↗
PubMed1995

Tat mediates transcriptional activation of HIV-1 gene in vitro.

Gene expression of human immunodeficiency virus (HIV-1) is greatly enhanced by a viral transactivator, the Tat protein, which interacts with R region sequences of the HIV-1 long terminal repeat (LTR). There is no direct evidence to indicate transcriptional activation of HIV-1 by Tat. Using an in vitro transcription system, we demonstrate that an established mouse cell line, which constitutively expresses Tat protein, selectively stimulates the steady state levels of the transcripts directed from the long terminal repeat (LTR) sequences of HIV-1. The gel binding retardation assays further demonstrate a stable activated complex, formed due to direct binding of Tat to DNA elements of the HIV-1 LTR. These data implicate transcription as the site of Tat action in trans-activation and could play an essential role in human immunodeficiency virus replication, similar to the nuclear trans-activators of other viruses.

Animals↗