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Biomedical subjects

J White

Publications and source records attributed to J White.

At least 37 records · Page 2Linked to original sources
PubMed2005

A cost-effectiveness analysis of heroin detoxification methods in the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD).

This economic evaluation was part of the Australian National Evaluation of Pharmacotherapies for Opioid Dependence (NEPOD) project. Data from four trials of heroin detoxification methods, involving 365 participants, were pooled to enable a comprehensive comparison of the cost-effectiveness of five inpatient and outpatient detoxification methods. This study took the perspective of the treatment provider in assessing resource use and costs. Two short-term outcome measures were used-achievement of an initial 7-day period of abstinence, and entry into ongoing post-detoxification treatment. The mean costs of the various detoxification methods ranged widely, from AUD 491 dollars(buprenorphine-based outpatient); to AUD 605 dollars for conventional outpatient; AUD 1404 dollars for conventional inpatient; AUD 1990 dollars for rapid detoxification under sedation; and to AUD 2689 dollars for anaesthesia per episode. An incremental cost-effectiveness analysis was carried out using conventional outpatient detoxification as the base comparator. The buprenorphine-based outpatient detoxification method was found to be the most cost-effective method overall, and rapid opioid detoxification under sedation was the most cost-effective inpatient method.

Adult↗
PubMed2005

Nutritional supplementation for stable chronic obstructive pulmonary disease.

BACKGROUND: Low body weight in patients with chronic obstructive pulmonary disease (COPD) is associated with an impaired pulmonary status, reduced diaphragmatic mass, lower exercise capacity and higher mortality rate when compared to adequately nourished individuals with this disease. Nutritional support may therefore be a useful part of their comprehensive care. OBJECTIVES: To conduct a systematic review of randomised controlled trials (RCTs) to clarify whether nutritional supplementation (caloric supplementation for at least 2 weeks) improved anthropometric measures, pulmonary function, respiratory muscle strength and functional exercise capacity in patients with stable COPD. SEARCH STRATEGY: Randomized controlled trials (RCTs) were identified from the Cochrane Airways Group register of RCTs, a hand-search of abstracts presented at international meetings and consultation with experts. Searches are current as of March 2004. SELECTION CRITERIA: Two reviewers independently selected trials for inclusion, assessed quality and extracted the data. DATA COLLECTION AND ANALYSIS: Within each trial and for each outcome, we calculated an effect size. The effect sizes were then pooled by a random-effects model. Homogeneity among the effect sizes was also tested. MAIN RESULTS: Eleven studies recruiting 352 participants met the inclusion criteria. Eight papers were considered as high quality. Two studies were double-blinded. For each of the outcomes studied, the effect of nutritional support was small: the 95% confidence intervals around the pooled effect sizes all included zero. The effect of nutritional support was homogeneous across studies. AUTHORS' CONCLUSIONS: Nutritional support had no significant effect on anthropometric measures, lung function or exercise capacity in patients with stable COPD.

Enteral Nutrition↗
PubMed2005

Nitrate respiration in the actinomycete Streptomyces coelicolor.

Streptomyces coelicolor is an obligate aerobic, filamentous soil-dwelling bacterium. Remarkably, the genome of S. coelicolor has three copies of the narGHJI operon that encodes respiratory nitrate reductase. This review summarizes our current views on the requirements for multiple nitrate reductases in S. coelicolor.

Bacterial Proteins↗
PubMed2005

Strength at the extracellular matrix-muscle interface.

Mechanical force is generated within skeletal muscle cells by contraction of specialized myofibrillar proteins. This paper explores how the contractile force generated at the sarcomeres within an individual muscle fiber is transferred through the connective tissue to move the bones. The initial key point for transfer of the contractile force is the muscle cell membrane (sarcolemma) where force is transferred laterally to the basement membrane (specialized extracellular matrix rich in laminins) to be integrated within the connective tissue (rich in collagens) before transmission to the tendons. Connections between (1) key molecules outside the myofiber in the basement membrane to (2) molecules within the sarcolemma of the myofiber and (3) the internal cytoplasmic structures of the cytoskeleton and sarcomeres are evaluated. Disturbances to many components of this complex interactive system adversely affect skeletal muscle strength and integrity, and can result in severe muscle diseases. The mechanical aspects of these crucial linkages are discussed, with particular reference to defects in laminin-alpha2 and integrin-alpha7. Novel interventions to potentially increase muscle strength and reduce myofiber damage are mentioned, and these are also highly relevant to muscle diseases and aging muscle.

Animals↗
PubMed2005

Delivery of nebulized budesonide is affected by nebulizer type and breathing pattern.

The aim of this study was to determine the output in-vitro of budesonide from two different nebulizers under simulated breathing conditions. The BimboNeb and Nebula nebulizers were used to nebulize 2 mL of budesonide (500 microg) suspension. Particle size was determined by inertial impaction after a 5-min nebulization. Total outputs of the drug from both nebulizers were measured using a sinus flow pump to create simulated breathing conditions. Paediatric and adult breathing patterns were used, with drug output measured after 5 and 10 min nebulization. The mass median aerodynamic diameter of budesonide using the BimboNeb (4.5 microm) was significantly greater than that from the Nebula (3.4 microm) (P<0.01). With the simulated adult breathing pattern, the total drug output after 5 min with the BimboNeb (61.5 microg) was twice that from the Nebula (30.7 microg). For the paediatric breathing pattern, total outputs were very similar for both nebulizers. In all cases, nebulizing for 10 min produced greater drug outputs compared with those after 5 min, particularly for the paediatric breathing pattern. The amount of aerosolized drug available for inhalation needs to be assessed for each nebuliser used and the effect of the patient's breathing pattern should also be taken into account.

Administration, Inhalation↗
PubMed2005

Spodoptera frugiperda pheromone lures to avoid nontarget captures of Leucania phragmatidicola.

We confirmed that commercial three- or four-component Spodoptera frugiperda (J.E. Smith) pheromone lures had a high nontarget capture rate for Leucania phragmatidicola Guenée, which compromised monitoring efforts in the northeastern United States. We compiled taxonomic features to distinguish L. phragmatidicola from S. frugiperda, and we compared five new lures. S. frugiperda catch specificity was improved by removing (Z)-11-hexadecen-1-ol acetate (Z11-16:Ac), which attracted L. phragmatidicola. Four lures tracked late-season S. frugiperda immigration, but two of these lures also tracked a bivoltine L. phragmatidicola flight with a second generation coincident with S. frugiperda immigration, and one lure attracted the first, but not the second, generation of L. phragmatidicola. In both low- and high-moth flight conditions, two-component lures had low L. phragmatidicola captures (0.5-1.4%), and although lures with more pheromonal components captured more S. frugiperda, they also had a high percentage of capture of L. phragmatidicola (38-48%). We conclude that although two-component lures captured fewer S. frugiperda, their similar temporal pattern, along with the lower level of L. phragmatidicola, makes them useful for development for monitoring programs in the northeastern United States.

Animals↗
PubMed2004

Alpha2 adrenergic agonists for the management of opioid withdrawal.

BACKGROUND: Withdrawal (detoxification) is necessary prior to drug-free treatment. It may also represent the end point of long-term treatment such as methadone maintenance. The availability of managed withdrawal is essential to an effective treatment system. OBJECTIVES: To assess the effectiveness of interventions involving the use of alpha2 adrenergic agonists (clonidine, lofexidine, guanfacine) to manage opioid withdrawal in terms of withdrawal signs and symptoms, completion of withdrawal and adverse effects. SEARCH STRATEGY: Multiple electronic databases (including MEDLINE, EMBASE, PsycINFO, Australian Medical Index, Cochrane Clinical Trials Register) were systematically searched. Reference lists of retrieved studies, reviews and conference abstracts were handsearched and relevant pharmaceutical companies contacted. SELECTION CRITERIA: Controlled trials comparing alpha2 adrenergic agonists with reducing doses of methadone, symptomatic medications or placebo, or comparing different alpha2 adrenergic agonists to modify the signs and symptoms of withdrawal in participants who were primarily opioid dependent. DATA COLLECTION AND ANALYSIS: One reviewer assessed studies for inclusion and undertook data extraction. Inclusion decisions and the overall process were confirmed by consultation between all four reviewers. MAIN RESULTS: Twenty-two studies, involving 1709 participants, were included. Eighteen were randomised controlled trials; for the remaining studies allocation was by participant choice in two, one used alternate allocation and in one the method of allocation was unclear. Twelve studies compared a treatment regime based on an alpha2 adrenergic agonist with one based on reducing doses of methadone. Diversity in study design, assessment and reporting of outcomes limited the extent of quantitative analysis. For the comparison of alpha2 adrenergic agonist regimes with reducing doses of methadone, there were insufficient data for statistical analysis, but withdrawal intensity appears similar to, or marginally greater with alpha2 adrenergic agonists, while signs and symptoms of withdrawal occur and resolve earlier in treatment. Participants stay in treatment longer with methadone. No significant difference was detected in rates of completion of withdrawal with adrenergic agonists compared to reducing doses of methadone, or clonidine compared to lofexidine. Clonidine is associated with more adverse effects (low blood pressure, dizziness, dry mouth, lack of energy) than reducing doses of methadone. Lofexidine does not reduce blood pressure to the same extent as clonidine, but is otherwise similar to clonidine. REVIEWERS' CONCLUSIONS: No significant difference in efficacy was detected for treatment regimes based on the alpha2 adrenergic agonists clonidine and lofexidine, and those based on reducing doses of methadone over a period of around 10 days, for the management of withdrawal from heroin or methadone. Participants stay in treatment longer with methadone regimes and experience less adverse effects. The lower incidence of hypotension makes lofexidine more suited to use in outpatient settings than clonidine. There are insufficient data available to support a conclusion on the efficacy of other alpha2 adrenergic agonists.

Acute Disease↗
PubMed2004

Buprenorphine for the management of opioid withdrawal.

BACKGROUND: Managed withdrawal (detoxification) is a necessary step prior to drug-free treatment. It may also represent the end point of long-term opioid replacement treatment such as methadone maintenance. The availability of managed withdrawal is essential to an effective treatment system. OBJECTIVES: To assess the effectiveness of interventions involving the use of buprenorphine to manage opioid withdrawal, in terms of withdrawal signs and symptoms, completion of withdrawal and adverse effects. SEARCH STRATEGY: Multiple electronic databases (including Medline, Embase, PsycINFO, Australian Medical Index, Cochrane Clinical Trials Register) were systematically searched to October 2003. Reference lists of retrieved studies, reviews and conference abstracts were handsearched. SELECTION CRITERIA: Controlled trials comparing buprenorphine with reducing doses of methadone, alpha2 adrenergic agonists, symptomatic medications or placebo, or comparing different buprenorphine-based regimes, to modify the signs and symptoms of withdrawal in participants who were primarily opioid dependent. DATA COLLECTION AND ANALYSIS: One reviewer assessed studies for inclusion and undertook data extraction. Inclusion decisions and the overall process were confirmed by consultation between all three reviewers. Included studies were assessed for methodological quality. Meta-analysis was undertaken where possible, with sensitivity analyses used to assess the impact of methodological quality. MAIN RESULTS: Thirteen studies (10 RCTs), involving 744 participants, met the criteria for inclusion in the review. Seven studies compared buprenorphine with clonidine; 3 compared buprenorphine with methadone; 1 compared buprenorphine with oxazepam; 2 compared rapid and slow rates of tapering buprenorphine dose; 1 compared 3 different starting doses of buprenorphine. For groups treated with buprenorphine, withdrawal severity was less than that in groups treated with clonidine; peak severity was similar to those treated with methadone, but withdrawal symptoms may resolve more quickly with buprenorphine. Withdrawal is probably more severe when doses are tapered rapidly following a period of maintenance treatment. Buprenorphine is associated with fewer adverse effects than clonidine, and completion of withdrawal is significantly more likely with buprenorphine (Relative Risk 1.35, 95% confidence interval 1.13, 1.62). In the two available studies, there was no statistically significant difference in rates of completion of withdrawal for buprenorphine compared to methadone in reducing doses. Completion of withdrawal following buprenorphine maintenance treatment may be more likely when doses are reduced gradually. REVIEWERS' CONCLUSIONS: Buprenorphine is more effective than clonidine for the management of opioid withdrawal. There appears to be no significant difference between buprenorphine and methadone in terms of completion of withdrawal, but withdrawal symptoms may resolve more quickly with buprenorphine. Many aspects of treatment protocol and relative effectiveness need to be investigated further in order to determine the most effective way of using buprenorphine to manage opioid withdrawal.

Acute Disease↗
PubMed2004

Complement regulation at the molecular level: the structure of decay-accelerating factor.

The human complement regulator CD55 is a key molecule protecting self-cells from complement-mediated lysis. X-ray diffraction and analytical ultracentrifugation data reveal a rod-like arrangement of four short consensus repeat (SCR) domains in both the crystal and solution. The stalk linking the four SCR domains to the glycosylphosphatidylinositol anchor is extended by the addition of 11 highly charged O-glycans and positions the domains an estimated 177 A above the membrane. Mutation mapping and hydrophobic potential analysis suggest that the interaction with the convertase, and thus complement regulation, depends on the burial of a hydrophobic patch centered on the linker between SCR domains 2 and 3.

CD55 Antigens↗
PubMed2004

Lymphoma presenting as a parotid tumour: a population-based study of diagnosis, treatment and outcome on behalf of the Scotland and Newcastle Lymphoma Group.

AIMS: Lymphoma presenting as a parotid tumour is rare. Previous published studies have been small and have not characterised fully the nature of lymphoma presenting this way. We studied the clinical features, diagnosis, prognosis and treatment in a patient group identified from the Scotland and Newcastle Lymphoma Registry, which is a prospectively collected population-based register of consecutive cases of lymphoma since 1979. MATERIALS AND METHODS: The study includes all patients with a biopsy-proven lymphoma in the parotid gland as the first presentation of their disease. RESULTS: Of 136 cases identified, 128 had non-Hodgkin's lymphoma (representing 1.5% of the 8499 non-Hodgkin's lymphomas in the registry) and eight had Hodgkin's disease (0.3% of the 2716 cases registered). Female to male ratio was 1.3:1, and median age was 69 years (range 19-94 years). Fifty-six per cent of patients had stage I, 16% had stage II, 11 % had stage III and 17% had stage IV disease. Diagnostic method was recorded in 81 cases; 47 of these were by parotidectomy. Overall median survival was 90 months, with a 5-year survival of 54%, but there was substantial variation according to age, grade, stage and International Prognostic Index (IPI). Diagnosis was often made by unnecessary major facial surgery, which could be avoided in many cases. CONCLUSION: Treatment should be directed by standard practice for lymphoma according to stage and histological classification.

Adult↗
PubMed2004

Concurrent ovarian-type primary peritoneal adenocarcinoma and peritoneal choriocarcinoma. A case report and review of the literature.

BACKGROUND: Nongestational choriocarcinomas are aggressive tumours occurring either as a global event or as a focal change in solid tumours. The latter is responsible for coexistence of trophoblastic histology with other malignancies. CASE: A 65-year old female with stage IV primary peritoneal carcinoma, ovarian type, underwent surgical cytoreduction followed by two courses of paclitaxel/carboplatin chemotherapy. A choriocarcinomatous component was later identified in the resection specimens, as chemotherapy resulted in a differential response of the two malignant variants. Commencement of EMA/CO chemotherapy (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine) resulted in symptom palliation and tumour regression, further consolidated with platinum-based EP/EMA (etoposide, cisplatin, methotrexate, actinomycin D). Two months later, relentless choriocarcinomatous disease progression followed, leading to the patient's death while the peritoneal adenocarcinomatous variant remained biochemically quiescent. CONCLUSION: Choriocarcinomas may coexist with typical ovarian-type peritoneal cancer, creating diagnostic and therapeutic dilemmas. Aggressive weekly chorio-type chemotherapy appears to be warranted despite the low likelihood of cure, as it provides significant symptom palliation.

Adenocarcinoma↗
PubMed2004

Remifentanil by bolus injection: a safety, pharmacokinetic, pharmacodynamic, and age effect investigation in human volunteers.

BACKGROUND: Although remifentanil's short-acting pharmacokinetic profile makes it well suited for procedures during which a brief period of intense analgesia is required, setting up an infusion pump for brief procedures is inconvenient. The clinical pharmacology of remifentanil administered by bolus injection, a more convenient alternative, has not been explored in detail. The primary aim of this study was to examine the safety of single bolus doses of remifentanil in conscious, healthy, adult volunteers breathing room air. Secondary aims included the evaluation of remifentanil pharmacokinetics and analgesic effects after bolus injection and a comparison of these issues in younger vs older adults. METHODS: Using a randomized, double-blind, placebo-controlled, dose-escalation, crossover study design, 64 subjects (16 over 60 years old) received remifentanil or placebo by bolus injection in a fixed unit dose separated by a 1 h washout period. Respiratory effects were assessed using a respiratory intervention scale. Analgesic effects were assessed using pressure algometry. A population pharmacokinetic model was constructed using non-linear, mixed-effects modelling techniques based on arterial blood samples. Computer simulations were performed to illustrate the clinical application of the pharmacokinetic model. RESULTS: Dose-related increases in both respiratory and analgesic effects were observed. In general, the respiratory depression observed was mild and easily treated with requests to breathe or the administration of oxygen, although the older cohort (and some younger subjects) experienced more substantial respiratory depression at lower doses. The pharmacokinetics of bolus-dose remifentanil were adequately described by a two-compartment model. The pharmacokinetic simulations illustrated the potential utility of bolus-dose remifentanil. CONCLUSIONS: Bolus injection could potentially be a safe and effective means of administering remifentanil in clinical situations requiring a brief period of intense analgesia. Because some subjects, both old and young, experienced significant respiratory depression even at low doses, careful monitoring of respiratory function is essential.

Adult↗
PubMed2004

Extranodal follicular lymphoma: a clinicopathological and genetic analysis of 15 cases arising at non-cutaneous extranodal sites.

AIMS: Recent studies of primary cutaneous follicular lymphoma suggest that it represents a clinicopathological entity distinct from nodal follicular lymphoma (FL). The purpose of this study was to determine if FL arising at other extranodal sites is more closely related to FL occurring in the skin or in lymph nodes. METHODS AND RESULTS: Fifteen cases of non-cutaneous extranodal follicular lymphoma (ENFL) were identified from the Scotland and Newcastle Lymphoma Group (SNLG) database. All were stage 1E at presentation and involved the tonsil (n = 3), palate (n = 3), skeletal muscle (n = 2), ileum (n = 2), duodenum (n = 1), stomach (n = 1), thyroid gland (n = 1), submandibular gland (n = 1) and fallopian tube (n = 1). Polymerase chain reaction for t(14;18) using primers to the major breakpoint cluster region was performed on 14 cases of ENFL and the incidence of the translocation compared with that found in 16 cases of stage 1 nodal FL. Clinical and follow-up data were obtained from the SNLG database for the 15 cases of ENFL and 87 cases of stage 1 nodal FL, and a comparison of outcomes made. Only 2/14 cases of ENFL had detectable t(14;18) compared with 9/16 stage 1 nodal FL (P < 0.01). Freedom from progression and disease-specific survival was similar for the 15 cases of ENFL and 87 cases of stage 1 nodal FL. However, 13/15 patients with ENFL were disease free at the end of follow-up compared with 49/87 stage 1 nodal FL (P < 0.02). CONCLUSIONS: The low incidence of t(14;18) and favourable outcome encountered in ENFL in this study is similar to that previously found for primary cutaneous FL. These results support the concept of a subtype of FL lacking t(14;18) involving the major breakpoint cluster region, and with a propensity to arise at extranodal sites. Despite a high relapse rate, patients with ENFL are more likely to achieve complete remission and may ultimately have a more favourable long-term prognosis than those with equivalent nodal disease.

Adult↗
PubMed2004

Parents measuring pulses; an observational study.

Parent reported pulse rates could provide important information on a child's clinical condition. The agreement between the parent's measurement of their child's pulse and a pulse oximeter was assessed following a brief educational intervention. Parents can be taught to measure the pulse of school age children, but have difficulty with preschool children.

Age Factors↗