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Biomedical subjects

G Donaldson

Publications and source records attributed to G Donaldson.

At least 19 recordsLinked to original sources
PubMed2006

Is there objective evidence that septal surgery improves nasal airflow?

OBJECTIVE: To identify any prospective, controlled trials providing objective evidence of a reduction in nasal airway resistance following nasal septal surgery, and to undertake a meta-analysis of available data. METHODS: A systematic review with meta-analysis of data was undertaken. A systematic review of the literature using a defined search strategy was conducted to identify papers that used objective methods of airway assessment to evaluate the benefit of septal surgery. Accepted techniques for objective airway assessment included acoustic rhinometry, active anterior rhinomanometry and peak nasal inspiratory airflow. Papers were included based on pre-defined criteria, which included standardization of techniques as outlined in the guidelines of the 1984 committee report on the standardization of rhinomanometry. RESULTS: We identified 942 articles, of which 13 were prospective studies evaluating the objective benefit of nasal septal surgery. Only three of these studies conformed to the inclusion criteria. A meta-analysis on these papers was performed using the Mantel-Haenszel method, and this demonstrated an overall reduction in nasal airway resistance following septal surgery for nasal obstruction (p=0.018). CONCLUSIONS: The majority of studies evaluating the objective benefit of septal surgery did not conform to the recommendations of the committee report on the standardization of rhinomanometry. Only three prospective controlled trials, with pooled data from 141 cases, were identified for meta-analysis. The conclusions that can be drawn concerning objective improvement in airway function following nasal septal surgery are therefore limited. More long-term studies, adhering to standardized techniques, are needed to provide more convincing data.

Airway Resistance↗
PubMed2005

Development, feasibility and compliance of a web-based system for very frequent QOL and symptom home self-assessment after hematopoietic stem cell transplantation.

We believe that many adverse events following hematopoietic stem cell transplantation (HSCT), particularly relapse and chronic graft-versus-host disease (CGVHD), are preceded by a subclinical period of development that is accessible by frequent psychometric assessment. Documenting these associations could improve future clinical care by extending the potential window for intervention. However, conventional methods of assessing quantity of lite (QOL) in patients in their homes, typically by mailed self-assessment questionnaires, are impractical for very frequent administration. We have developed and implemented a web-based system for measuring short-term (dynamic) changes in QOL by employing brief, online, daily QOL assessments and more extensive, monthly online assessments from patients' homes. Here we report the feasibility of collecting very frequent patient home self-assessments of QOL via the web for a 52 week participation period; we detail incidence of home web access, accrual, compliance, and satisfaction with the system in an HSCT patient sample. We also describe our integrated web-systems for administering patient recruitment, scheduling, monitoring, and analysis. Our results suggest that very frequent routine collection of QOL outcomes is entirely feasible using our web-based home assessment tool, with good patient compliance and high user satisfaction. We believe our methodology shows great promise for use with other cancer and health populations.

Adult↗
PubMed2005

Quality control of equipment in home mechanical ventilation: a European survey.

Quality control of the equipment used in home mechanical ventilation is necessary in order to ensure that patients safely and accurately receive the prescribed ventilatory support. The aim of this study was to carry out a survey on the quality-control procedures in different centres and countries. The survey was carried out in the context of a European Commission Concerted Action covering 16 European countries. The study was extensive and detailed, involving 326 centres, which provided home ventilation to >20,000 patients. The survey showed that: 1) ventilator servicing was mainly carried out by external companies (62% of centres), with a servicing frequency ranging 3-12 months; 2) interaction between servicing companies and prescribers was limited (only 61% of centres were always informed of major incidents); 3) participation of centres in equipment quality control was poor (only 56% of centres assessed that patients/caregivers correctly cleaned/maintained the ventilator); and 4) centres were insufficiently aware of vigilance systems (only 23% of centres). Moreover, the data showed considerable inter- and intra-country differences. The size of the centre was an important determinant of many of these quality-control aspects. This survey provides information that will enable the European Commission Concerted Action to formulate recommendations on procedures for home-ventilator quality control.

Chronic Disease↗
PubMed2005

Neuroendoscopy in Jamaica.

This retrospective, descriptive study reviewed the patient profile, disease spectrum, indications for and results of treatment and complications of all 27 patients who had neuroendoscopy at the University Hospital of the West Indies (UHWI) over the three-year period between November 2000, when the service was first introduced, and November 2003. Nineteen (67.9%) were males and eight were females. Their mean age was 27.5 +/- 21.4 years with a range of four months to 70 years. Of the entire group, 20 had hydrocephalus with raised intracranial pressure, of which 15 had endoscopic third ventriculostomy (ETV) for the treatment of obstructive hydrocephalus, using two different techniques for ventricular floor fenestration. There was no demonstrable difference in outcome between the water jet and blunt forceps techniques. Three procedures failed to relieve the hydrocephalus, requiring subsequent ventriculo-peritoneal shunts. Three patients had successful cyst fenestrations. Six patients had endoscope assisted trans-sphenoidal resection for pituitary tumours. There were five complications and no deaths. Mean hospital stay was 18.4 +/- 16.7 days and mean follow-up was 29 weeks. There were no late failures. Neuroendoscopy is the treatment of choice for obstructive hydrocephalus due to aqueduct stenosis or posterior fossa tumours and has the advantage of avoiding shunt related complications. It is safe and effective for the majority of patients and has a significant role in the management of neurosurgical patients in the Caribbean.

Adult↗
PubMed2004

Infections in neurosurgical patients admitted to the intensive care unit at the University Hospital of the West Indies.

Patients admitted to the Intensive Care Unit (ICU) are at risk of developing life-threatening nosocomial infections, especially with organisms resistant to commonly used antibiotics. Neurosurgical patients are particularly vulnerable because of the serious nature of their illness, the frequency of associated trauma and the presence of invasive devices. Of 120 neurosurgical patients admitted to the ICU of the University Hospital of the West Indies (UHWI) between September 1995 and December 1999, the records of 73 patients were available for analysis. All had prophylactic antibiotics. Twenty-one of these 73 patients (28.8%) developed 22 infections after a mean of five days in the ICU: nine with chest infection, seven with urinary tract infection, four with central nervous system (CNS) infection and one each with wound and skin infection. This is an incidence of 11.6/1000 patient-days. The responsible organisms included Pseudomonas (7/21), Acinetobacter (3/21), E. coli 2/21, Enterobacter (2/21), and Klebsiella (2/21), and one each with Staphylococcus aureus, methicillin resistant Staphylococcus aureus, coagulase negative Staphylococcus, group D Streptococcus and bacteroides (1/21). Infection was significantly related to length of hospital stay, length of ICU stay, duration of intubation, duration of ventilation and the presence of diabetes mellitus. All patients who had surgery after ICU admission developed infection, seven with chest infection, two with urinary tract infection, two with CNS and one with skin infection. The three patients who were admitted with intracranial infections all developed other infections. Infected patients had a significantly longer hospital stay. Five patients died, none directly attributable to infection, while 55 (75.5%) made a good recovery. The problem of ICU infection may be expected to escalate with the increased use of intensive care, increasingly more complex surgical procedures and the growing problem of antibiotic resistance. Since infection is related to the length of ICU stay, earlier discharge of neurosurgical patients to an appropriately staffed high dependency unit is likely to result in reduction of the infection rate. Reinforcement of infection control strategies within the ICU may be expected to further minimize the infection rate.

Adolescent↗
PubMed2003

Comparative analysis on the genetic relatedness of Sorghum bicolor accessions from Southern Africa by RAPDs, AFLPs and SSRs.

In order to get an overview on the genetic relatedness of sorghum (Sorghum bicolor) landraces and cultivars grown in low-input conditions of small-scale farming systems, 46 sorghum accessions derived from Southern Africa were evaluated on the basis of amplified fragment length polymorphism (AFLPs), random amplified polymorphic DNAs (RAPDs) and simple sequence repeats (SSRs). By this approach all sorghum accessions were uniquely fingerprinted by all marker systems. Mean genetic similarity was estimated at 0.88 based on RAPDs, 0.85 using AFLPs and 0.31 based on SSRs. In addition to this, genetic distance based on SSR data was estimated at 57 according to a stepwise mutation model (Deltamu-SSR). All UPGMA-clusters showed a good fit to the similarity estimates (AFLPs: r = 0.92; RAPDs: r = 0.88; SSRs: r = 0.87; Deltamu-SSRs: r = 0.85). By UPGMA-clustering two main clusters were built on all marker systems comprising landraces on the one hand and newly developed varieties on the other hand. Further sub-groupings were not unequivocal. Genetic diversity (H, DI) was estimated on a similar level within landraces and breeding varieties. Comparing the three approaches to each other, RAPD and AFLP similarity indices were highly correlated (r = 0.81), while the Spearman's rank correlation coefficient between SSRs and AFLPs was r = 0.57 and r = 0.51 between RAPDs and SSRs. Applying a stepwise mutation model on the SSR data resulted in an intermediate correlation coefficient between Deltamu-SSRs and AFLPs (r = 0.66) and RAPDs ( r = 0.67), respectively, while SSRs and Deltamu-SSRs showed a lower correlation coefficient (r = 0.52). The highest bootstrap probabilities were found using AFLPs (56% on average) while SSR, Deltamu-SSR and RAPD-based similarity estimates had low mean bootstrap probabilities (24%, 27%, 30%, respectively). The coefficient of variation (CV) of the estimated genetic similarity decreased with an increasing number of bands and was lowest using AFLPs.

Africa, Southern↗
PubMed2001

Experiences of donors enrolled in a randomized study of allogeneic bone marrow or peripheral blood stem cell transplantation.

The experiences of 69 (38 marrow and 31 peripheral blood stem cell [PBSC]) donors participating in a randomized trial comparing allogeneic bone marrow with PBSC transplantation were studied. Marrow was collected by means of standard harvest techniques and general or regional anesthesia. PBSC donors were treated with 5 to 7 days of filgrastim at a dose of 16 microg/kg/d and underwent 1 to 3 days of apheresis to obtain 5 x 10(6) CD34(+) cells per kilogram recipient weight. Donors completed questionnaires describing their health experiences before, during, and then weekly after donation until return to baseline status. Both marrow and PBSC donors reported minimal fluctuation in symptoms measuring emotional status. In contrast, both groups of donors reported deterioration in physical status starting with administration of filgrastim (PBSC donors) or after the marrow collection procedure. The symptom burden reported was similar, with pain a prominent symptom for both groups. Equivalent mean levels of maximal pain, average pain, and pain duration through the day were reported, although toxicity peaks occurred at different time points during the harvest procedures. All PBSC donors but only 79% of marrow donors reported good physical status by 14 days after the harvest procedures. These data demonstrate similar levels of physical discomfort for hematopoietic stem cell donors regardless of the collection procedure used, but a quicker resolution of symptoms for PBSC donors.

Adolescent↗
PubMed2001

Genetic approaches to harvesting lichen products.

Lichens are symbiotic associations between fungi, green algae and/or cyanobacteria. They have a varied chemistry and produce many polyketide-derived compounds, including some, such as depsides and depsidones, that are rarely reported elsewhere. Although lichens have been appreciated in traditional medicines, their value has largely been ignored by the modern pharmaceutical industry because difficulties in establishing axenic cultures and conditions for rapid growth preclude their routine use in most conventional screening processes. Recently, molecular genetic techniques using PCR, genomic library construction and heterologous expression have provided an alternative approach to begin exploring the diversity of polyketide biosynthetic pathways in lichens. The techniques can be expanded to cover other pathway types and be integrated with conventional culture collection-based screening to provide a comprehensive search for novel chemical entities in these organisms.

Amino Acid Sequence↗
PubMed2000

Morphine-fluoxetine interactions in healthy volunteers: analgesia and side effects.

The authors evaluated the ability of fluoxetine, a selective serotonin reuptake inhibitor (SSRI), to enhance the analgesic potency of morphine. Fifteen volunteers participated in this double-blind crossover study. All received combinations of morphine or saline with either fluoxetine 30 mg or placebo. The authors used individual morphine pharmacokinetics to program an infusion pump to achieve plasma morphine levels of 15, 30, and 60 ng/ml. Analgesia during morphine infusion was assessed using a model of electrical tooth stimulation. Subjective side effects, measurements of end-tidal CO2, O2 saturation, pupil size, and testing of psychomotor performance were obtained. Plasma morphine concentrations were not affected by fluoxetine. In comparison to placebo, oral fluoxetine resulted in less sedation during morphine infusion and less nausea during morphine washout. Morphine-induced pruritus, psychomotor function, and respiratory depression were unaffected by fluoxetine. Acute administration of 30 mg oral fluoxetine augmented analgesia by approximately 3% to 8% and reduced morphine-associated nausea, mood reduction, and drowsiness.

Adult↗
PubMed2000

Brain abscess at the University Hospital of the West Indies.

Surgical infections of the central nervous system are still attended by high rates of morbidity and mortality, although substantial progress has been made since the advent of computed tomography (CT) scanning technology. In this retrospective review of 25 surgically treated patients with either brain abscess or subdural empyema at the University Hospital of the West Indies, the majority of patients were male and between the ages of 10 and 30 years with a mean age of 16.9 years. Almost half the patients had a hemiparesis on presentation while 60% had fever. Subdural empyema was more common than a localized intracerebral abscess which was most frequently located in the frontal lobe. The most common predisposing factors were sinusitis and congenital heart disease. Streptococci spp and Staphylococci spp were the most frequently isolated organisms. All patients underwent CT scanning and surgical intervention. The mortality rate was 20%, and 21% of the survivors had late seizures. There must be a high index of clinical suspicion and early referral to specialist centres where neuroradiological investigation and prompt neurosurgical intervention can be carried out to minimize morbidity and mortality.

Adolescent↗
PubMed2000

Spinal injuries at the University Hospital of the West Indies.

Acute spinal damage forms a small percentage of total trauma injury but it has tremendous significance because of the resultant disability, poor prognosis, economic and social cost and the burden on victims, family, taxpayers and health workers. Of fifty-five patients admitted to the University Hospital of the West Indies (UHWI), Mona, Jamaica, over a seven-year period, forty form the basis of this report. Young males accounted for most victims and 85% of the injuries were non-intentional. The cervical spine, most commonly C6, was the region most frequently injured, followed by the lumbar and the thoracic regions. On admission, the mean Glasgow Coma Score was 14.6 and the mean Modified Injury Severity Score 12.7. Five patients were admitted in Frankel Grade A, complete paraplegia. Of eighteen patients treated with steroids, only eleven had methylprednisolone and only six of these appropriately. Nine patients had surgery after a mean time of 10.1 days. The average length of hospital stay was 18.2 days. Of 35 patients whose outcomes were known, eleven improved; two patients died in hospital. With the modernization of the management of this condition, we recommend that attention be focused on prevention, pre-hospital immobilization and transport, prompt resuscitation, the standardization of written protocols and early operative intervention. Also essential is the continuing medical education of all levels of personnel and the formalization of a well-coordinated and rehearsed Spine team.

Adolescent↗
PubMed1998

CARE-PARTNER: a computerized knowledge-support system for stem-cell post-transplant long-term follow-up on the World-Wide-Web.

Evidence-based practice in medicine promotes the performance of medicine based upon proven and validated practice. The CARE-PARTNER system presented here is a computerized knowledge-support system for stem-cell post-transplant long-term follow-up (LTFU) care on the WWW, which means that it monitors the quality of the knowledge both of its own knowledge-base and of its users. Its aim is to support the evidence-based practice of the LTFU clinicians and of the home-town physicians who actually care for the transplanted patients. Currently, three fundamental characteristics of CARE-PARTNER are accountable for its knowledge-support function: the quality of its knowledge-base, its availability on the WWW, and its learning from experience capability. As a matter of fact, the integration of a case-based reasoner in the reasoning framework enables the system to introspectively study its results, and to learn from its successes and failures, thus confronting the quality of the guidelines and pathways it reuses to the reality and complexity of the clinical cases.

Artificial Intelligence↗
PubMed1997

Comparative efficacy of patient-controlled administration of morphine, hydromorphone, or sufentanil for the treatment of oral mucositis pain following bone marrow transplantation.

A total of 119 bone marrow transplant patients suffering from oral mucositis pain were enrolled in a randomized, double-blind, parallel-group trial comparing the efficacy of patient-controlled analgesia with morphine, hydromorphone and sufentanil. Patient ratings of pain and side-effects on visual analog scales were gathered daily from the start of patient-controlled analgesia (PCA) therapy until the discontinuation of opioid treatment either because of resolution of oral mucositis pain, intolerable side-effects, inadequate pain control, or complications related to transplantation. Of the 119 enrolled subjects, 100 met the evaluable criteria of developing oral mucositis and remaining on the study for at least 2 days. Multivariate analysis of the outcome measures indicated that the analgesia achieved in all three opioid groups was nearly equivalent, while measures of side-effects, especially for the combination of sedation, sleep and mood disturbances, were statistically lower in the morphine group than in hydromorphone or sufentanil groups. Patients in the hydromorphone group exhibited the most variability in pain control. Event analysis also indicated significant differences in time to treatment failure between the three groups, with the morphine arm exhibiting clear superiority. The proportion of patients discontinued because of inadequate pain relief was much higher in the sufentanil group (7/36) as compared to the hydromorphone (0/34) or the morphine group (1/30). The daily opioid consumption pattern showed a continual dose escalation during the first week of therapy for all groups, coincident with worsening mucositis. Morphine consumption reached a plateau by day 5, whereas hydromorphone and sufentanil consumption continued to rise until days 7 and 9, respectively. Sufentanil dose requirement increased by approximately 10-fold compared to morphine and hydromorphone, whose requirements increased only 5-fold, suggesting the possibility of development of acute pharmacological tolerance in some patients with this phenylpiperidine opioid. This study provides support for the recommendation that morphine is the opioid of first choice when patient-controlled analgesia is employed for the treatment of severe oropharyngeal pain in bone marrow transplantation (BMT) patients.

Adolescent↗
PubMed1997

Hydromorphone analgesia after intravenous bolus administration.

This study investigated the analgesic effects of three intravenous bolus doses of hydromorphone (10, 20, 40 micrograms/kg) on experimental pain measures in normal humans. Ten healthy male volunteers participated in four study sessions, one for each of the hydromorphone doses as well as a placebo (saline). They received the four treatments in counterbalanced order under double-blind conditions and with study days at least 1 week apart. During each session subjects underwent repeated electrical tooth pulp stimulation at intensities sufficient to elicit a rating of 'strong pain' before drug administration. Subjective pain reports (PRs) and dental evoked potential amplitude measures (EPs) served as analgesic effect indicators. We observed dose-dependent analgesia as measured by both PR (P = 0.009) and EP (P = 0.017). Area under the PR versus time curve as well as the EP versus time curve decreased in a log dose-dependent fashion. Although the peak effect was poorly defined, the onset of analgesia was rapid, within 5 min, and maximum analgesic effect was seen between 10 and 20 min after maximum plasma hydromorphone concentration. However, within sessions we found a poor correspondence between hydromorphone plasma concentration and effect. Compared to pain report data from other human studies done in our laboratory, hydromorphone has a shorter time to peak effect compared to morphine, and overall, hydromorphone hydrochloride is approximately five times as potent as morphine sulfate on a milligram basis.

Adult↗
PubMed1996

Between practice and theory: Melanie Klein, Anna Freud and the development of child analysis.

An examination of the early history of child analysis in the writings of Melanie Klein and Anna Freud reveals how two different and opposing approaches to child analysis arose at the same time. The two methods of child analysis are rooted in a differential emphasis on psychoanalytic theory and practice. The Kleinian method derives from the application of technique while the Anna Freudian method is driven by theory. Furthermore, by holding to the Freudian theory of child development Anna Freud was forced to limit the scope of child analysis, while Klein's application of Freudian practice has led to new discoveries about the development of the infant psyche.

Austria↗
PubMed1996

Effects of combining propofol and alfentanil on ventilation, analgesia, sedation, and emesis in human volunteers.

BACKGROUND: Propofol and alfentanil frequently are administered together for intravenous sedation. This study investigated pharmacokinetic and pharmacodynamic interactions between propofol and alfentanil, at sedative concentrations, with specific regard to effects on ventilation, analgesia, sedation, and nausea. METHODS: Ten male volunteers underwent steady-state infusions on 3 separate days consisting of propofol alone, alfentanil alone, or a combination of the two. Target plasma concentrations for propofol were 150, 300, and 600 ng/ml for 1 h at each concentration; for alfentanil it was 40 ng/ml for 3 h. Assessment included serial measurements of (1) ventilatory function (minute ventilation, carbon dioxide production, end-tidal carbon dioxide, ventilatory response to rebreathing 7% CO2); (2) analgesia (subjective pain report in response to graded finger shock and evoked potential amplitude); (3) sedation (subjective rating, observer scores, and digit symbol substitution test); (4) nausea (visual analog scale, 0-100 mm). RESULTS: During combination treatment, propofol plasma concentration was 22% greater than during propofol alone using replicate infusion schemes (P < 0.009). End-tidal carbon dioxide was unchanged by propofol, and increased equally by alfentanil and alfentanil/propofol combined (delta end-tidal carbon dioxide 7.5 and 6.2 mmHg, respectively). Analgesia with propofol/alfentanil combined was greater than with alfentanil alone. (Pain report decreased 50% by PA vs. 28% for alfentanil, P < 0.05). Sedation was greater with propofol/alfentanil combined than with alfentanil or propofol alone (digit symbol substitution test 30 for propofol/alfentanil combined vs. 57 for alfentanil, and 46 for propofol, P < 0.05). Nausea occurred in 50% of subjects during alfentanil, but in none during propofol/alfentanil combination treatment. CONCLUSIONS: The combination of propofol and alfentanil produced greater sedation and analgesia than that with either drug alone. Propofol offset the emetic effects of alfentanil. Equivalent depression of the carbon dioxide response curve, and elevation of end-tidal carbon dioxide occurred with propofol/alfentanil combined and alfentanil.

Adult↗
PubMed1995

Quality of life of 125 adults surviving 6-18 years after bone marrow transplantation.

BACKGROUND: Recent studies examining the medical and psychosocial sequelae of bone marrow transplantation have reported most survivors do relatively well while a smaller group continues to experience less than optimal quality of life (QOL). Many of these studies are limited by small sample sizes, limited scope, and focus on a narrow (1-4 year) window of survival. METHODS: The descriptive survey examined the QOL, late medical complications, psychological distress, demands of long-term recovery, and health perceptions of 125 adults surviving 6-18 (mean 10) years after marrow transplantation. Seven wide-ranging tests covering 271 items were completed on average in 90 min. Two tests were developed by the authors specifically for assessing QOL in this population. RESULTS: 74% of long-term survivors of bone marrow transplantation reported their current QOL was the same or better than before transplantation, 80% rated their current health status and QOL as good to excellent, and 88% said the benefits of transplantation outweighed the side effects. Ten years or more post-transplantation, long-term survivors continued to experience a moderate incidence of lingering complications and demands, including emotional and sexual dysfunction, fatigue, eye problems, sleep disturbance, general pain and cognitive dysfunction. However, the severity or degree of distress attributed to those complications was, for most survivors, consistently low. Nearly all were back to work or school. Only 5% rated both their QOL and health status as poor. Long-term survivors demonstrated good mood and low psychological distress compared to cancer and population norms, and had the same perceptions as the general population of their current health and expectation of future health. Demands attributed to long-term survival appeared to impose little hardship. The most frequently cited demand of recovery was the perceived lack of social support as time went on. CONCLUSIONS: Almost all long-term survivors were leading full and meaningful lives. Persistent complications were, on the whole, dismissed as relatively trivial and the overwhelming majority viewed themselves as cured and well.

Adult↗