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Biomedical subjects

R Anderson

Publications and source records attributed to R Anderson.

At least 73 records · Page 4Linked to original sources
PubMed2001

A prospective study comparing i.m. ketorolac with i.m. meperidine in the treatment of acute biliary colic.

Ketorolac is a nonsteroidal anti-inflammatory medication that is used widely for pain management. Its effects are mediated through the inhibition of prostaglandins, which makes it uniquely different from opioids in relieving pain. We conducted a randomized, prospective, double blind study of patients presenting to our Emergency Department (ED) with a diagnosis of acute biliary colic. Study patients were randomized into one of two treatment groups, meperidine 1.5 mg/kg with a maximum dose of 100 mg or ketorolac 60 mg given intramuscularly (i.m.). The patients rated their pain before and 30 min after medication on a scale of 1 to 10 using a Visual Analog Pain Scale. Overall pain relief was compared between the two groups using a two-sample t test. Thirty patients were enrolled in the study, 16 in the ketorolac group and 14 in the meperidine group. Patients ranged in age from 18 to 71 years and 6 (20%) were male. The average pain score at time 0 was 7.6 for the ketorolac group and 7.3 for the meperidine group. Pain relief at time 30 min was 3.8 in the ketorolac group and 3.9 in the meperidine group, which was not statistically different. The mean global pain score and need for an emergency cholecystectomy were similar in the two groups. Rescue medication for additional analgesia at 30 min was needed in 4 patients in the meperidine group and in 2 patients in the ketorolac group (28.6% versus 12.5%, respectively; NS). In this study of patients with acute biliary colic there was no significant difference in the pain relief achieved by using either ketorolac or meperidine.

Adolescent↗
PubMed2001

Accuracy in equianalgesic dosing. conversion dilemmas.

The clinical benefit and increased application of opioid rotation has focused attention on efficacy differences between opioids and their respective equianalgesic dose ratios. Understanding the differences between the opioids is critical to understanding their equianalgesic dose ratios and for adjusting therapy following rotation to a new analgesic. The purpose of this article is to describe controversies regarding the relative potencies of these agents as presented in current equianalgesic charts and to provide pharmacologic information to assist the clinician with opioid rotation.

Analgesics, Opioid↗
PubMed2001

Localization of the netrin guidance receptor, DCC, in the developing peripheral and enteric nervous systems.

Over recent years the secreted guidance cue, netrin-1, and its receptor, DCC, have been shown to be an essential guidance system driving axon pathfinding within the developing vertebrate central nervous system (CNS). Mice lacking DCC exhibit severe defects in commissural axon extension towards the floor plate demonstrating that the DCC-netrin guidance system is largely responsible for directing axonal projections toward the ventral midline in the developing spinal cord (Fazeli et al., Nature 386 (1997) 796). In addition, these mutants lack several major commissures within the forebrain, including the corpus callosum and the hippocampal commissure. In contrast to the CNS, the role of the DCC guidance receptor in the development of the mammalian peripheral and enteric nervous systems (PNS and ENS) has not been investigated. Here we demonstrate using immunohistochemical analysis that the DCC receptor is present in the developing mouse PNS where it is found on spinal, segmental, and sciatic nerves, and in developing sensory ganglia and their associated axonal projections. In addition, DCC is present in the ENS throughout the early developmental phase.

Animals↗
PubMed2001

Additional value of electrical impedance scanning: experience of 240 histologically-proven breast lesions.

The aim of this study was to quantify the clinical value of using electrical impedance scanning (EIS) as an adjunct to other diagnostic techniques in order to identify cancerous tissue based upon its inherent altered local dielectric properties. 210 consecutive women with 240 sonographically and/or mammographically suspicious findings were examined using EIS. All lesions were histologically-proven. 86/103 malignant and 91/137 benign lesions were correctly identified using EIS (87.8% sensitivity, 66.4% specificity). NPV and PPV of 84.3% and 65.2% were observed, respectively. Excluding cases as defined by a priori criteria, i.e. lesions located deeper than 35 mm, lesions larger than 35 mm, and retroareolar lesions, a sensitivity of 85.5% was observed, and for invasive cancers, 91.7%. The detection rate for ductal carcinoma in situ (DCIS) was poor (57.1%, n=14). By adding EIS to mammography and ultrasound, the sensitivity rose from 86.4 to 95.1%, whereas the accuracy decreased from 82.3 to 75.7%. EIS appears to be of interest as an adjunct to breast diagnostic techniques, performing with a reasonable sensitivity. Further investigations on histomorphological characteristics and the reasons for false-negative findings are essential to gain further knowledge about the bioelectricity of breast lesions, and prove the value of this new technology.

Breast Neoplasms↗
PubMed2001

The effects of lowering fresh gas flow during sevoflurane anaesthesia: a clinical study in patients having elective knee arthroscopy.

The potential for minimising anaesthetic gas consumption with a circle absorber system is related to fresh gas flow. This study measured the actual sevoflurane consumption during elective arthroscopy of the knee in 75 ASA I-II patients randomised to three fresh gas flow rates (6, 3, and 1.5 l/min) using sevoflurane and O(2):N(2)O (1:2) after intravenous induction with fentanyl and propofol. A circle absorber system was used with a laryngeal mask airway. Anaesthetic duration, discharge time and postoperative pain did not differ between groups. Sevoflurane consumption was more than doubled with each doubling of fresh gas flow (0.07+/-0.03; 0.16+/-0.05; 0.41+/-0.12 ml sevoflurane/min; for gas flow 1.5, 3, 6 l/min; P<0.01). The hourly sevoflurane related cost decreased from 15.5 to 2.8 US$ when reducing the fresh gas flow from 6 to 1.5 l/min. Decreasing the fresh gas flow from 6 to 1.5 l/min provides good anaesthetic depth with effective reduction in anaesthetic consumption, cost and environmental burden.

Journal Article↗
PubMed2001

Psychosocial factors and adherence to treatment advice in childhood atopic dermatitis.

Poor adherence to maintenance treatment for atopic dermatitis and anxiety about using topical steroids are common features seen among children with atopic dermatitis and their mothers. No systematic study exploring factors associated with adherence to treatment advice on atopic dermatitis has been carried out to date. This study seeks to generate hypotheses regarding the relationship between a range of psychosocial factors and adherence to treatment advice on atopic dermatitis. An anonymous self-completed questionnaire containing adherence items, psychosocial items, some demographic items, and attitudes to steroid use was given to 258 mothers of atopic dermatitis follow-up patients who attended the National Children's Hospital, Tokyo. Responses from 205 families (80%) with complete data were then analyzed to explore the correlation between each factor and to build a structure equation model. The strongest predictor of adherence to skin-care treatment was a good doctor-patient (mother) relationship, followed by the severity of the disease as perceived by the mother. Surprisingly, the mother's anxiety about using topical steroids had no significant influence on reported use of topical steroids nor on adherence to skin-care treatment. This may have been overcome by the well-established doctor-patient (mother) relationship. Maternal personality, husband's cooperation, and social support were indirectly correlated with adherence via the doctor-patient relationship. Maternal self-efficacy of treatment was strengthened by good doctor-patient (mother) relationship.

Adolescent↗
PubMed2001

Accelerated calcium influx and hyperactivation of neutrophils in chronic granulomatous disease.

The relationship between activation of NADPH-oxidase, alterations in membrane potential and triggering of Ca2+ fluxes in human phagocytes has been investigated using neutrophils from four subjects with chronic granulomatous disease (CGD). Cytosolic Ca2+ and membrane potential were measured by spectrofluorimetry, and net efflux and influx of Ca2+ by radiometric procedures. Exposure of normal neutrophils to the chemotactic tripeptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP; 1 microM) was accompanied by an abrupt increase in cytosolic Ca2+ coincident with membrane depolarization and efflux of the cation. These events terminated at around 30 s after the addition of FMLP and were followed by membrane repolarization and store-operated influx of Ca2+, both of which were superimposable and complete after about 5 min. Activation of CGD neutrophils was also accompanied by an increase in cytosolic Ca2+, which, in spite of an efficient efflux response, was prolonged in relation to that observed in normal cells. This prolonged increase in cytosolic Ca2+ in activated CGD neutrophils occurred in the setting of trivial membrane depolarization and accelerated influx of Ca2+, and was associated with hyperactivity of the cells according to excessive release of elastase and increased activity of phospholipase A2. Treatment of CGD neutrophils with the type 4 phosphodiesterase inhibitor, rolipram (1 microM) restored Ca2+ homeostasis and attenuated the increase in elastase release. These findings support the involvement of NADPH-oxidase in regulating membrane potential and Ca2+ influx in activated neutrophils, and may explain the disordered inflammatory responses and granuloma formation which are characteristic of CGD.

Adolescent↗
PubMed2001

Adenoviral gene transfer restores lysyl hydroxylase activity in type VI Ehlers-Danlos syndrome.

Type VI Ehlers-Danlos syndrome is a disease characterized by disturbed lysine hydroxylation of collagen. The disease is caused by mutations in lysyl hydroxylase 1 gene and it affects several organs including the cardiovascular system, the joint and musculoskeletal system, and the skin. The skin of type VI Ehlers-Danlos syndrome patients is hyperelastic, scars easily, and heals slowly and poorly. We hypothesized that providing functional lysyl hydroxylase 1 gene to the fibroblasts in and around wounds in these patients would improve healing. In this study we tested the feasibility of transfer of the lysyl hydroxylase 1 gene into fibroblasts derived from rats and a type VI Ehlers-Danlos syndrome patient (in vitro) and into rat skin (in vivo). We first cloned human lysyl hydroxylase 1 cDNA into a recombinant adenoviral vector (Ad5RSV-LH). Transfection of human type VI Ehlers-Danlos syndrome fibroblasts (about 20% of normal lysyl hydroxylase 1 activity) with the vector increased lysyl hydroxylase 1 activity in these cells to near or greater levels than that of wild type, unaffected fibroblasts. The adenoviral vector successfully transfected rat fibroblasts producing both beta-galactosidase and lysyl hydroxylase 1 gene activity. We next expanded our studies to a rodent model. Intradermal injections of the vector to the abdominal skin of rats produced lysyl hydroxylase 1 mRNA and elevated lysyl hydroxylase 1 activity, in vivo. These data suggest the feasibility of gene replacement therapy to modify skin wound healing in type VI Ehlers-Danlos syndrome patients.

Adenoviridae↗
PubMed2001

An implantable neuroprosthesis for restoring bladder and bowel control to patients with spinal cord injuries: a multicenter trial.

OBJECTIVE: To evaluate the safety and efficacy of an implanted neuroprosthesis for management of the neurogenic bladder and bowel in individuals with spinal cord injury (SCI). DESIGN: Prospective study comparing bladder and bowel control before and at 3, 6, and 12 months after implantation of the neuroprosthesis. SETTING: Six US hospitals specializing in treatment of SCI. PATIENTS: Twenty-three neurologically stable patients with complete suprasacral SCIs. INTERVENTION: Implantation of an externally controlled neuroprosthesis for stimulating the sacral nerves and posterior sacral rhizotomy. MAIN OUTCOME MEASURES: Ability to urinate more than 200mL on demand and a resulting postvoid residual volume of less than 50mL. RESULTS: At 1-year follow-up, 18 of 21 patients could urinate more than 200mL with the neuroprosthesis, and 15 of 21 had postvoid volumes less than 50mL (median, 15mL). Urinary tract infection, catheter use, reflex incontinence, anticholinergic drug use, and autonomic dysreflexia were substantially reduced. At 1-year follow-up, 15 of 17 patients reduced the time spent with bowel management. CONCLUSIONS: Neural stimulation and posterior rhizotomy is a safe and effective method of bladder and bowel management after suprasacral SCI.

Chi-Square Distribution↗
PubMed2001

Differentiation of mammographically suspicious lesions: evaluation of breast ultrasound, MRI mammography and electrical impedance scanning as adjunctive technologies in breast cancer detection.

AIM: Various modalities are used as an adjunct to mammography for differentiation of potentially suspicious breast lesions. Electrical impedance scanning (EIS) is a new technique based upon the principle that cancer cells exhibit altered local dielectric properties and thus show measurably higher conductivity values. The accuracy of differentiation of benign and malignant breast lesions was evaluated to determine whether EIS duplicates or supplements the results obtainable from ultrasound (US) or magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred mammographically suspicious lesions were examined using US, MRI and EIS. Definitive histology was acquired through either lesion biopsy or surgical excision. RESULTS: Fifty of 62 malignant lesions were correctly identified using EIS (81% overall sensitivity), 24/38 benign lesions were correctly identified as benign (63% specificity). Negative predictive value and positive predictive value of 67 and 78% were observed, respectively. kappa-factor evaluation revealed a value of 0.82 between MRI and EIS and 0.62 between US and EIS. CONCLUSIONS: EIS may be a valuable adjunct for differentiation of suspicious mammographic lesions. Based upon the calculated kappa-factor, EIS results supplement US examinations. Artifacts (superficial skin lesions, poor contact, air bubbles) currently result in the high false-positive rate of EIS.

Breast Neoplasms↗
PubMed2001

Attenuation of increase in circulating cortisol and enhancement of the acute phase protein response in vitamin C-supplemented ultramarathoners.

Supplementary vitamin C (2 x 500 mg tablets daily) or a matched placebo was administered to 10 and 6 ultramarathon athletes respectively for 7 days prior to participation in a 90 kilometer running event, as well as on the day of the race and for 2 days after its completion. Circulating concentrations of vitamins A, C and E, as well as those of leukocytes and platelets, myeloperoxidase, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF), cortisol, and creatine kinase were measured 16 hours before the race and at 30 min, 24 hours, and 48 hours after completion. Pre-race vitamin C concentrations in the supplemented group were unchanged after the race (118.2 +/- 15.9 and 115.9 +/- 11.9 micromol/l) while an increase was observed in the placebo group immediately post-race (85.8 +/- 11.9 to 107.4 +/- 18.8 micromol), with a return to pre-race values after 24 hours. Immediately on completion of the race transient elevations occurred in the concentrations of circulating neutrophils, monocytes and platelets, IL-6, cortisol, CRP, and creatine kinase in both groups. In the supplemented group the concentrations of CRP were significantly higher (p < 0.01) at each of the post-race time-points while those of cortisol were 30% lower immediately post-race. These observations provide evidence that supplementation with vitamin C may blunt the adaptive mobilization of this vitamin from the adrenals during exercise-induced oxidative stress and may be associated with an enhancement of the acute phase protein response and attenuation of the exercise-induced increase in serum cortisol.

Acute-Phase Proteins↗
PubMed2001

Vitamin C supplementation attenuates the increases in circulating cortisol, adrenaline and anti-inflammatory polypeptides following ultramarathon running.

The effects of vitamin C supplementation on the alterations in the circulating concentrations of cortisol, adrenaline, interleukin-10 (IL-10) and interleukin-1 receptor antagonist (IL-1Ra) which accompany ultramarathon running were measured using immuno-chemiluminescence, radioimmunoassay and ELISA procedures. Forty-five participants in the 1999 Comrades 90 km marathon were divided into equal groups (n = 15) receiving 500 mg/day Vit C (VC-500), 1500 mg/day Vit C (VC-1500) or placebo (P) for 7 days before the race, on the day of the race, and for 2 days following completion. Runners recorded dietary intake before, during and after the race and provided 35 ml blood samples 15 - 18 hrs before the race, immediately post-race, 24 hrs post race and 48 hrs post-race. Twenty-nine runners (VC-1500, n = 12; VC-500, n = 10; P, n = 7) complied with all study requirements. All post-race concentrations were adjusted for plasma volume changes. Analyses of dietary intakes and blood glucose and anti-oxidant status on the day preceding the race and the day of the race did not reveal that carbohydrate intake or plasma vitamins E and A were significant confounders in the study. Mean pre-race concentrations of serum vitamin C in VC-500 and VC-1500 groups (128 +/- 31 and 153 +/- 34 micromol/l) were significantly higher than in the P group (83 +/- 39 micromol/l). Immediate post-race serum cortisol was significantly lower in the VC-1500 group (p < 0.05) than in P and VC-500 groups. When the data from VC-500 and P groups was combined (n = 17), immediate post-race plasma adrenaline, IL-10 and IL-1Ra concentrations were also significantly lower (p < 0.05) in the VC-1500 group. The study demonstrates an attenuation, albeit transient, of both the adrenal stress hormone and anti-inflammatory polypeptide response to prolonged exercise in runners who supplemented with 1500 mg vitamin C per day when compared to < or = 500 mg per day.

Administration, Oral↗
PubMed2001

[Performance and simulation of intermittent decanted extended aeration treatment plants in a tropical climate].

The paper discusses the design and performance of package sewage treatment plants using the Intermittently Decanted Extended Aeration Process (IDEA-Process) in a tropical climate. This hybrid SBR process has been developed overcome traditional drawbacks associated with the SBR process, such as high Sludge Volume Index, high weir loading rate for decanting, and the need to achieve a better effluent quality, especially in terms of nutrient removal. Three domestic sewage plants in Thailand has been selected for field-testing and results of analyses are presented. The average measured biological removal efficiencies in terms of BOD removal and COD removal are about 95.5% and 90% respectively, and the average total nitrogen removal efficiency is about 90%. A computer model is used to study the performance of IDEA-processes compared to results from laboratory tests. The model experience gained through this research are discussed regarding the limitations of computer models such as ASM 1 (Activated Sludge Model n degrees 1) applied to the IDEA-Process in order to develop a new computer model suitable for design and operation of package treatment plant using IDEA-Process Technology in the future.

Bioreactors↗
PubMed2001

Data logging technology in ambulatory medical instrumentation.

This paper reviews the advancements made in ambulatory data logging used in the study of human subjects since the inception of the analogue tape based data logger in the 1960s. Research into the area of ambulatory monitoring has been rejuvenated due to the development of novel storage technologies during the 1990s. Data logging systems that were previously impractical due to lack of processing power, practical size and cost are now available to the practitioner. An overview of the requirements of present day ambulatory data logging is presented and analogue tape, solid-state memory and disk drive storage recording systems that have been described in the literature are investigated in detail. It is proposed that digital based technology offers the best solution to the problems encountered during human based data logging. The appearance of novel digital storage media will continue the trend of increased recording durations, signal resolution and number of parameters thus allowing the momentum gained throughout the last several decades to continue.

Humans↗
PubMed2001

Antimycobacterial action of B4128, a novel tetramethylpiperidyl-substituted phenazine.

The effects of the novel tetramethylpiperidyl (TMP)-substituted phenazine, B4128 (0.6-2.5 mg/L), on growth, phospholipase A2(PLA2) activity, cation (K+, Ca2+) fluxes and energy metabolism (ATP) of Mycobacterium aurum A(+) and Mycobacterium tuberculosis (H37Ra) have been investigated in vitro. Growth, PLA2 and cation fluxes were measured radiometrically, while microbial ATP was assayed by means of a luciferin/luciferase chemiluminescence method. Exposure of the mycobacteria to B4128 resulted in immediate, dose-related enhancement of microbial PLA2 activity and inhibition of K+ influx, which preceded effects on microbial ATP, influx of Ca2+ and growth. These results demonstrate that B4128 possesses membrane-directed antimycobacterial properties that are similar to those of clofazimine.

Adenosine Triphosphate↗