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Biomedical subjects

B Smith

Publications and source records attributed to B Smith.

At least 37 records · Page 2Linked to original sources
PubMed2001

Quality of life in asthma: a comparison of community and hospital asthma patients.

This study compares the quality of life of a community sample of people with asthma in South Australia, using population norms, people suffering from other chronic diseases, and a sample of asthma patients from two hospital clinics. A representative population survey was performed by trained interviewers in spring 1995 of 3001 respondents aged > or = 15 years. A physician's diagnosis of current asthma was reported by 299 (9.9%). The hospital clinic sample had a physician's diagnosis and lung function evidence of asthma (n = 293). All completed the SF-36 health survey. Standardized SF-36 scores, adjusted for age, sex, and social class, were significantly lower for respondents with asthma, compared with population norms, across all subscales of the SF-36 (p < 0.05). Physical component summary (PCS) and mental component summary (MCS) scores were not significantly different in people in the community sample with asthma from scores in people with diabetes and arthritis. PCS and MCS scores did not differ for those with similar symptom frequency in the community and hospital asthma samples, except that hospital patients with frequent symptoms had significantly lower MCS scores (p < 0.01). Asthma has a major impact on the health-related quality of life in the community, comparable to other chronic diseases. The SF-36 performs uniformly in asthma in different situations.

Adolescent↗
PubMed2001

Asthma care by nurse practitioners in the United States.

PURPOSE: To survey nurse practitioners (NPs) in the United States on their level of input to asthma care prior to enrolling in The National Asthma and Respiratory Training Centre (NARTC) specialist asthma education program in the UK. DATA SOURCES: Responses of 134 (66%) of the 202 NPs who self-selected for enrollment in the NARTC program on a preliminary questionnaire. CONCLUSIONS: Nearly all (133 or 99%) currently work with asthmatics and 122 (91%) prescribe asthma drugs. Only 92 (69%) measure peak flow(PF), 84 (63%) check inhaler technique, 76 (57%) teach use of a home PF meter and diary, and 63 (47%) provide written self-management plans on any regular basis. Many have not established follow-up procedures (56 or 42%), or evaluated their asthma management practices (55 or 41%). IMPLICATIONS FOR PRACTICE: Successful asthma management requires correct medication, systematic follow-up, patient education, and self-management. Specialist asthma training should encourage practitioners to combine effective drug usage with a long-term preventative approach.

Asthma↗
PubMed2001

The role of exon 5 in fibroblast collagenase (MMP-1) substrate specificity and inhibitor selectivity.

Interstitial collagen is degraded by members of the matrix metalloproteinase (MMP) family, including MMP-1. Previous work has shown that the region of MMP-1 coded for by exon 5 is implicated both in substrate specificity and inhibitor selectivity. We have constructed a chimeric enzyme, the exon 5 chimera, consisting primarily of MMP-1, with the region coded for by exon 5 replaced with the equivalent region of MMP-3, a noncollagenolytic MMP. Unlike MMP-3, the exon 5 chimera is capable of cleaving type I collagen, but the activity is only 2.2% of trypsin-activated MMP-1. 'Superactivation' of the chimera has no discernible effect, suggesting that the salt bridge formed in 'superactive' MMP-1 is not present. The kinetics for exon 5 chimera cleavage of two synthetic substrates display an MMP-3 phenotype, however, cleavage of gelatin is slightly impaired as compared to the parent enzymes. The K(iapp) values for the exon 5 chimera complexed with synthetic inhibitors and N-terminal TIMP-2 also show a more MMP-3-like behaviour. However, the k(on) values for N-terminal TIMP-1 and N-terminal TIMP-2 are more comparable to those for MMP-1. These data show that the region of MMP-1 coded for by exon 5 is involved in both substrate specificity and inhibitor selectivity and the structural basis for our findings is discussed.

Amino Acid Sequence↗
PubMed2000

Estrogen priming modulates autoreceptor-mediated potentiation of dopamine uptake.

The ability of a physiological dose of estrogen (estradiol benzoate, estrogen: 10 microgram 48 and 24 h prior) to modulate autoreceptor-mediated changes in dopamine transport properties was investigated in a synaptosomal preparation prepared from the nucleus accumbens of ovariectomized rats. Quinpirole (1-100 microM)-mediated potentiation of [3H]dopamine uptake was attenuated in synaptosomes from estrogen-primed animals. Haloperidol (10 microM) inhibited basal uptake and effectively prevented quinpirole potentiation of uptake in both ovariectomized and estrogen-primed samples. The ability of selective protein phosphatase inhibitors to modulate autoreceptor-mediated potentiation of dopamine uptake was also examined. Pretreatment with protein phosphatase 2B (deltamethrin, cypermethrin) or protein phosphatase 1 (tautomycin) inhibitors attenuated basal and quinpirole-potentiated dopamine uptake in ovariectomized but not estrogen-primed tissue. These data suggest that autoreceptor-mediated activation of dopamine transport can be regulated by physiological doses of estrogen and implicate a role for protein phosphorylation in autoreceptor-mediated potentiation of dopamine uptake.

Animals↗
PubMed2000

Biochemical characterization of the catalytic domain of human matrix metalloproteinase 19. Evidence for a role as a potent basement membrane degrading enzyme.

We have recently cloned MMP-19, a novel matrix metalloproteinase, which, due to unique structural features, was proposed to represent the first member of a new MMP subfamily (Pendás, A. M., Knäuper, V. , Puente, X. S., Llano, E., Mattei, M. G., Apte, S., Murphy, G., and López-Otin, C. (1997) J. Biol. Chem. 272, 4281-4286). A recombinant COOH-terminal deletion mutant of MMP-19 (proDelta(260-508)MMP-19), comprising the propeptide and the catalytic domain, was expressed in Escherichia coli, refolded, and purified. Interestingly, we found that proDelta(260-508)MMP-19 has the tendency to autoactivate, whereby the Lys(97)-Tyr(98) peptide bond is hydrolyzed, resulting in free catalytic domain. Mutation of two residues (Glu(88) --> Pro and Pro(90) --> Val) within the propeptide latency motif did not prevent autoactivation but the autolysis rate was somewhat reduced. Analysis of the substrate specificity revealed that the catalytic domain of MMP-19 was able to hydrolyze the general MMP substrate Mca-Pro-Leu-Gly-Dpa-Ala-Arg-NH(2) and, with higher efficiency, the stromelysin substrate Mca-Pro-Leu-Ala-Nva-Dpa-Ala-Arg-NH(2). Kinetic analysis of the interactions of the catalytic domain of MMP-19 with the natural MMP inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), showed strong inhibition using TIMP-2, TIMP-3, and TIMP-4, while TIMP-1 was less efficient. We also demonstrated that synthetic hydroxamic acid-based compounds efficiently inhibited the enzyme. The catalytic domain of MMP-19 was able to hydrolyze the basement membrane components type IV collagen, laminin, and nidogen, as well as the large tenascin-C isoform, fibronectin, and type I gelatin in vitro, suggesting that MMP-19 is a potent proteinase capable of hydrolyzing a broad range of extracellular matrix components. Neither the catalytic domain nor the full-length MMP-19 was able to degrade triple-helical collagen. Finally, and in contrast to studies with other MMPs, MMP-19 catalytic domain was not able to activate any of the latent MMPs tested in vitro.

Amino Acid Sequence↗
PubMed2000

An adult formulation of a five-component acellular pertussis vaccine combined with diphtheria and tetanus toxoids is safe and immunogenic in adolescents and adults.

Pertussis is increasingly being recognized as an important cause of cough illness in adolescents and adults. To evaluate the safety and immunogenicity of an adult formulation of a five-component (pertussis toxoid, filamentous hemagglutinin, pertactin, fimbriae 2 and 3) acellular pertussis vaccine combined with diphtheria and tetanus toxoids, we randomly allocated 749 healthy adolescents and adults from 12-54 years of age recruited from five Canadian communities to receive either tetanus-diphtheria vaccine (Td), acellular pertussis vaccine (aP) or combined diphtheria-tetanus-acellular pertussis vaccine (TdaP). Subjects and personnel were unaware of the vaccine allocation. Antibody levels were measured before and one month postimmunization; adverse events were collected at 24 and 72 h and 8 to 10 days. Adverse events were reported in similar frequency amongst the three vaccine groups. Moderate pain at the injection site was reported less frequently in the aP group than the TdaP group (10.7% compared to 19.4%; relative risk 0.6, 95% confidence interval 0.3-0.9). Chills were reported less frequently after Td (5.3%) than after TdaP (12.5%; relative risk 0.4, 95% confidence interval 0.2-0.9). There were no statistically significant differences between recipients of Td and TdaP in tetanus and diphtheria antitoxin levels achieved. Antibody response against Bordetella pertussis antigens was vigorous in all groups although recipients of aP alone had higher levels of antibody levels against pertussis toxoid, fimbriae, and agglutinins and lower antibody levels against pertactin than did TdaP recipients. We conclude that this adult formulation 5-component acellular pertussis vaccine is safe and immunogenic in adolescents and adults and is a candidate vaccine for adolescent and adult immunization programs.

Adolescent↗
PubMed2000

Raman spectroscopic method for identification of clinically relevant microorganisms growing on solid culture medium.

Routine clinical microbiological identification of pathogenic microorganisms is largely based on nutritional and biochemical tests. In the case of severely ill patients, the unavoidable time delay associated with such identification procedures can be fatal. We present a novel identification method based on confocal Raman microspectroscopy. With this approach it is possible to obtain Raman spectra directly from microbial microcolonies on the solid culture medium, which have developed after only 6 h of culturing for the most commonly encountered organisms. Due to the limited thickness of microcolonies, some of the underlying culture medium is sampled together with the bacteria. Spectra measured at different depths in a microcolony contain different amounts of the medium signal. A mathematical routine, involving vector algebra, is described for the nonsubjective correction of spectra for variable signal contributions of the medium. To illustrate the possibilities of our approach for the identification of microorganisms, Raman spectra were collected from 6-h microcolonies of five bacterial strains on solid culture medium. The classification results show that confocal Raman microspectroscopy has great potential as a powerful new tool in clinical diagnostic microbiology.

Bacteriological Techniques↗
PubMed2000

Rational treatment of empyema in children.

HYPOTHESIS: Efficacious and cost-effective treatment of pediatric empyema can be accomplished following a protocol based on its radiographic appearance. Therapeutic modalities include thoracostomy tube drainage (TTD) with or without fibrinolytic therapy (FT) and video-assisted thoracoscopic debridement (VATD). DESIGN: Retrospective case series. SETTING: Tertiary referral center. RESULTS: From 1995 through 1999, 31 children were treated ranging in age from 11 months to 18 years (mean age, 5.1 years). Twenty-seven (87.1%) underwent TTD; of these, 22 (81.5%) received FT with urokinase. The TTD failed in 4 children (14.8%) who required salvage VATD. Primary VATD was performed in another 4 children (12.9%). The mean length of stay was 14.6 days (TTD, 14.1 days; salvage VATD, 20. 0 days; primary VATD, 11.5 days), ranging from 8.0 to 30.0 days. Complications included readmission for fever (2 patients [6.5%]) and gastrointestinal bleeding (1 patient [3.2%]). There were no anaphylactic reactions or bleeding episodes due to urokinase. Two patients (7.4%) treated with TTD and FT developed an air leak that resolved spontaneously. The mean hospital charges were $78,832 (TTD with or without FT, $75,450; salvage VATD, $107,476; primary VATD, $69,634). The procedural charges were highest for salvage VATD. CONCLUSIONS: Most cases of pediatric empyema can be treated by TTD with or without FT. This therapy is safe and effective for children with nascent disease. Primary VATD is preferred in children with advanced disease. Cost-effectiveness could be further improved through better prediction of those patients likely to fail TTD and require salvage VATD. An algorithmic approach based on findings from computed tomography or (better) ultrasonography of the chest may be the best way to make this distinction and rationalize care.

Adolescent↗
PubMed2000

Home care by outreach nursing for chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by progressive airflow obstruction, worsening exercise performance and deterioration in health. It is associated with significant morbidity, mortality and costs to health care systems. Care strategies, such as outreach nursing in the community, may reduce this burden. OBJECTIVES: To evaluate the effectiveness of outreach respiratory health care worker programmes for patients with COPD in terms of improving lung function, exercise tolerance and health related quality of life (HRQL) of patient and carer, and reducing mortality and hospital service utilisation. SEARCH STRATEGY: A search was carried out using the Cochrane Airways Group database. Bibliographies of identified RCTs were searched for additional relevant RCTs. Authors of identified RCTS were contacted for other published and unpublished studies. SELECTION CRITERIA: Only randomised control trials of patients with COPD were included. The intervention was an outreach nurse visiting patients in their homes, providing support, education, monitoring patient status and providing liaison with physicians. Interventions that used nurse practitioners who provided therapeutic intervention were also included. Studies in which the therapeutic intervention under test was physical training were not included. DATA COLLECTION AND ANALYSIS: Data extraction and study quality assessment were performed independently by two reviewers. Where further or missing data was required, authors of studies were contacted. MAIN RESULTS: Four studies were found. Three assessed mortality following twelve months of care (n=96, 152 and 301), and one after seven months(n=75). Meta-analysis demonstrated that mortality was not significantly reduced by the intervention, Peto Odds Ratio 0.72; 95 % confidence interval 0.43, 1.21. Post hoc subgroup analysis suggested that mortality was reduced by the outreach nursing programme in patients with less severe disease. Significant improvements in health related quality of life were reported in one study in moderate COPD, but not in a study in patients with severe disease. No changes in lung function or exercise performance were found in the studies where data were available. Hospital admissions were reported in only one study in patients with severe disease and no benefit was observed. REVIEWER'S CONCLUSIONS: Patients with moderate COPD may have mortality and health related quality of life gains from a nursing outreach programme, but there are no data about reductions in hospital utilisation. Patients with severe COPD do not appear to have benefit from such programmes and one large study found no reduction in hospital admissions in such patients.

Community-Institutional Relations↗
PubMed2000

Long-acting beta2-agonists for chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by airflow limitation which is only partially reversible. Long acting beta2-agonists, effective in the management of asthma,are also recommended for COPD management so it is important to establish whether these drugs are effective in reducing COPD symptoms in view of the potential side effect and cost burden. OBJECTIVES: To determine the effectiveness of long acting beta2-adrenoceptor agonists in improving lung function and quality of life and reducing dyspnoea in patients with COPD. SEARCH STRATEGY: A search was carried out using the Cochrane Airways Group register. Bibliographies of identified RCTs were searched for additional relevant RCTs. Authors of identified RCTs were contacted for other published and unpublished studies. In addition, unpublished studies were also obtained from the pharmaceutical companies that manufacture long acting beta2- adrenoceptor agonists. SELECTION CRITERIA: All randomised controlled trials over four weeks in duration comparing treatment with long-acting beta2-adrenoceptor agonists (salmeterol and formoterol) with placebo in patients with stable non-reversible COPD. Outcome measures included forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), symptom scores, six minute walk distance, quality of life scores, Borg scores for dyspnoea and rescue bronchodilator use. DATA COLLECTION AND ANALYSIS: Data extraction and study quality assessment was performed independently by two reviewers. Where further or missing data were required, authors of studies were contacted. MAIN RESULTS: Thirty three abstracts were identified as potentially relevant. Of these, four randomised controlled trials (RCTs) were included in this review. Two were parallel group studies of 16 week duration and two were cross-over studies with four week treatment arms. All four RCTs assessed the efficacy of salmeterol in COPD. In a 16 week study of salmeterol 50 mcg and 100 mcg twice daily treatment, a significant increase in FEV1 was seen in both treatment groups. The weighted mean difference (WMD) for the increase in FEV1 for the 50 mcg group was 0.10 litre (95% CI: 0.05;0. 15) and in the 100 mcg group the WMD was 0.12 litre (95% CI: 0.06; 0. 17 ). In the two cross-over studies of four weeks treatment, salmeterol 50 mcg twice daily treatment did not show significant increases in FEV1 (WMD = 0.04 litre, 95% CI: -0.06; 0.15). Similarly, morning and night time PEFR was not significantly improved with salmeterol treatment. In a 16 week study, disease-specific quality of life, measured using the St. George's Respiratory Questionnaire (SGRQ), showed a significant improvement after 50 mcg twice daily, but not after 100 mcg twice daily. This improvement exceeded the threshold for a clinically significant change with this questionnaire. General health status, as measured by the Medical Outcomes Short Form 36, did not improve in any of the eight components with either salmeterol dose. No significant difference was demonstrated in the mean change from baseline in the six minute walk distance (WMD = 1.9 metres, 95% CI: -15.4;19.3). Breathlessness was reduced in one study in patients receiving salmeterol 50 mcg twice daily group. Significantly more patients in this group had Borg scores for breathlessness less than three (a score of three indicating moderate dyspnoea) compared to the placebo treated group (Peto Odds Ratio = 0.60, 95% CI: 0.40; 0.88). Neither dose of salmeterol influenced the incidence of COPD exacerbations, (50 mcg: Peto Odds Ratio = 0.74, 95% CI: 0.47, 1.15) and (100 mcg: Peto Odds Ratio = 0.98, 95% CI: 0.64, 1.52). REVIEWER'S CONCLUSIONS: Treatment of patients with COPD with long acting beta2-agonists produces only small increases in FEV1. In one study, a dose of salmeterol 50 mcg twice daily produced a reduction in breathlessness and a clinically significant improvement in quality of life. (ABSTRACT TRUNCATED)

Adrenergic beta-Agonists↗
PubMed2000

Quantitative description of the workload associated with airway management procedures.

STUDY OBJECTIVES: To measure the workload associated with specific airway management tasks. SETTING AND INTERVENTION: Written survey instrument. PATIENTS: 166 Stanford University and 75 University of California, San Diego, anesthesia providers. MEASUREMENTS AND MAIN RESULTS: Subjects were asked to use a seven-point Likert-type scale to rate the level of perceived workload associated with different airway management tasks with respect to the physical effort, mental effort, and psychological stress they require to perform in the typical clinical setting. The 126 subjects completing questionnaires (overall 52% response rate) consisted of 43% faculty, 26% residents, 23% community practitioners, and 8% certified registered nurse-anesthetists (CRNAs). Faculty physicians generally scored lower workload measures than residents, whereas community practitioners had the highest workload scores. Overall, workload ratings were lowest for laryngeal mask airway (LMA) insertion and highest for awake fiberoptic intubation. Airway procedures performed on sleeping patients received lower workload ratings than comparable procedures performed on awake patients. Direct visualization procedures received lower workload ratings than fiberoptically guided procedures. CONCLUSIONS: These kinds of data may permit more objective consideration of the nonmonetary costs of technical anesthesia procedures. The potential clinical benefits of the use of more complex airway management techniques may be partially offset by the impact of increased workload on other clinical demands.

Adult↗
PubMed2000

Transient hemifacial sensory loss with xerophthalmia following temporal lobectomy.

OBJECTIVE AND IMPORTANCE: The occurrence of a unilateral sensory loss in the second trigeminal distribution and the inability to tear following an ipsilateral temporal lobectomy has not been noted despite a number of reports of cranial nerve compromise under similar situations. CLINICAL PRESENTATION: A 48-year-old woman experienced complex partial seizures over three years attributable to the presence of cavernous malformations of the right temporal lobe. INTERVENTION: An anterior temporal extrahippocampal resection was performed. The surgery was marked by the need for electrocoagulation of the dural base of the temporal lobe where numerous bleeding points were encountered. Postoperatively, the patient experienced an ipsilateral maxillary division sensory loss, absence of tearing, and diminished nasal congestion for an eight-month period until resolution. CONCLUSION: Injury of the fibers of the maxillary division of the trigeminal nerve and the adjacent greater superficial petrosal nerve appears to be the cause. No prior account of such an occurrence has been published.

Electrocoagulation↗
PubMed2000

Caspase-dependent and independent cell death in rat hepatoma 5123tc cells.

The objective of this study was to establish whether apoptosis in 5123tc rat hepatoma cells required the caspase-3 dependent pathway. Apoptosis was induced by either growth factor deprivation or treatment with a topoisomerase II inhibitor, VM26, in the absence or presence of caspase inhibitors (DEVD-fmk, z-VAD-fmk and BAF). The results indicated that, although these inhibitors at 10 microM concentration completely blocked caspase-3 activity, they had no effect on either the rate of cell death or on any other apoptotic features, e.g., chromatin condensation, DNA fragmentation, protein cleavage, suggesting that caspase-3 was not required to mediate nuclear destruction in these hepatoma cells. At higher concentrations, up to 100 microM, z-VAD-fmk and BAF, but not DEVD-fmk, did block apoptosis, however, they also caused cell swelling and membrane permeabilization, which are the hallmarks of necrotic cell death. Clearly, high concentrations of these inhibitors must have interfered non-specifically with other metabolic pathways, e.g., z-VAD-fmk at a high concentration blocked protein phosphorylation, and caused cell death by a different mechanism.

Amino Acid Chloromethyl Ketones↗
PubMed2000

Multiple respiratory symptoms predict quality of life in chronic lung disease: a population-based study of Australian adults.

STUDY OBJECTIVES: Previous studies have shown that it is possible to improve the health-related quality of life (HRQoL) of chronic lung disease (CLD) patients without a concurrent change in morbidity. A valid CLD index that discriminates between different levels of CLD severity and is associated with HRQoL status is an important tool for primary care settings. In this study a symptom-based CLD index was assessed for its validity and relationship with HRQoL in a representative Australian population sample. The study also measured the prevalence of self-reported CLD. DESIGN: Representative population survey of adults aged 18 years and over using a multistage, systematic, clustered area sample. SETTING: Metropolitan Adelaide and country centres in South Australia with a population of over 1000 persons. PARTICIPANTS: Three hundred twenty-nine adults with CLD identified through a representative population survey of 3010 South Australians. MEASUREMENTS AND RESULTS: The CLD index and the SF-36 were administered to participants to assess the association between each subscale of the CLD index with each HRQoL scale. The CLD index was also used to assess the prevalence of CLD and the distribution of severity in self-reported CLD in the South Australian population. Each symptom sub-scale of the CLD index was significantly correlated with all scales of the SF-36. The prevalence of CLD as measured by the CLD index was 7.7% (mild), 2.2% (moderate) and 1.0% (severe). CONCLUSIONS: In the Australian context the CLD index is a reliable patient interview instrument that can be used to assess the effects of CLD on general HRQoL, improve assessment, and lead to interventions for physicians and their patients.

Adolescent↗