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Biomedical subjects

Michael Smith

Publications and source records attributed to Michael Smith.

At least 19 recordsLinked to original sources
PubMed2006

Isothermal calorimetry: impact of measurements error on heat of reaction and kinetic calculations.

Heat flow and power compensation calorimetry measures the power generation of a reaction via an energy balance over an appropriately designed isothermal reactor. However, the measurement of the power generated by a reaction is a relative measurement, and calibrations are used to eliminate the contribution of a number of unknown factors. In this work the effect of the error in the measurement of temperature of electric power used in the calibrations and the heat transfer coefficient and baseline is assessed. It has been shown that the error in all aforementioned quantities reflects on the baseline and it can have a very serious impact on the accuracy of the measurement. The influence of the fluctuation of ambient temperature has been evaluated and a means of a correction that reduces its impact has been implemented. The temperature of dosed material is affected by the heat loses if reaction is performed at high temperature and low dosing rate. An experimental methodology is presented that can provide means of assessment of the actual temperature of the dosed material. Depending on the reacting system, the heat of evaporation could be included in the baseline, especially if non-condensable gases are produced during the course of the reaction.

Algorithms↗
PubMed2006

Isolation and characterization of a cold-active xylanase enzyme from Flavobacterium sp.

Xylan is the major component of hemicellulose, and xylan should be fully utilized to improve the efficiencies of a biobased economy. There are a variety of industrial reaction conditions in which an active xylanase enzyme would be desired. As a result, xylanase enzymes with different activity profiles are of great interest. We isolated a xylanase gene (xyn10) from a Flavobacterium sp. whose sequence suggests that it is a glycosyl hydrolase family 10 member. The enzyme has a temperature optimum of 30 degrees C, is active at cold temperatures, and is thermolabile. The enzyme has an apparent Km of 1.8 mg/ml and kcat of 100 sec-1 for beechwood xylan, attacks highly branched native xylan substrates, and does not have activity against glucans.

Amino Acid Sequence↗
PubMed2006

Nonmammographic evaluation of the extent of breast carcinoma.

The role of the breast imager has evolved beyond detecting breast cancer. With emphasis on management with breast conservation therapy, it has become imperative to image the patient preoperatively to adequately determine tumor size and to establish the presence or absence of multifocal, multicentric, or contralateral malignancy. The focus of this article was to provide a review of the current literature examining nonmammographic modalities available to the radiologist to thoroughly evaluate the newly diagnosed breast cancer patient. Our emphasis will be on breast ultrasound and magnetic resonance imaging (MRI). Specific topics discussed include the role, efficacy, and availability of these modalities in the assessment of ductal carcinoma in situ (DCIS) and invasive carcinoma. Mammography remains the standard for the evaluation of the extent of DCIS. However, ultrasound and MRI have been shown to be invaluable adjuncts in the evaluation of the patient with invasive carcinoma, especially those who are considering breast conservation therapy.

Breast Neoplasms↗
PubMed2006

Association of medication adherence with workplace productivity and health-related quality of life in patients with asthma.

OBJECTIVE: Examine the association of medication adherence with workplace productivity and health-related quality of life (HRQL) in asthma patients. METHODS: Adult patients with asthma in a state health insurance program identified from medical claims (July 2001-June 2003) were mailed a three-part survey to measure HRQL (St. George's Respiratory Questionnaire), workplace productivity (Workplace Productivity Short Inventory), and self-reported medication adherence (Morisky Scale). RESULTS: The symptoms domain had the worst HRQL scores, followed by the activity and impacts domains; 39% of the participants reported themselves as "high" adherent, whereas 19% were "medium," and 42% were "low" adherent. Asthma resulted in productivity losses of 597 +/- 1,024 US dollars (absenteeism) and 658 +/- 1,808 US dollars (presenteeism) per enrollee per year. CONCLUSIONS: Asthma was associated with HRQL detriments and workplace productivity losses.

Absenteeism↗
PubMed2006

Using the Internet to enhance the treatment of depression.

OBJECTIVE: Deficiencies in Australia's mental health systems persist despite over a decade of mental health reform. Recent developments in e-health provide the opportunity to facilitate health reform and improve services. This paper presents preliminary findings from the implementation of a comprehensive e-health system, called RecoveryRoad, which was designed to augment the routine clinical treatment of depression. METHODS: Depressed patients (n = 144) were referred to RecoveryRoad from a public hospital and public and private clinics in Perth, Western Australia. Online features included secure e-consultations, progress monitoring questionnaires, psychoeducation and evidence-based therapy. Treating clinicians had online access to patients' progress monitoring outcomes and e-consultations. There were two types of adherence reminders: automated email reminders and personalized case management delivered by email and telephone. RESULTS: Adherence to the system was high (from 53% to 84%, depending on the modality of reminder), and self-reported medication adherence was over 90%. Average depression severity declined from severe to mild by the eighth session, a large effect (d = 1.0). Both clinicians and patients were generally satisfied with the programme and reported that it improved clinician-patient relationships. Clinicians also reported that it helped patients to better manage depression. CONCLUSIONS: Preliminary findings support the feasibility of comprehensive e-health systems in enhancing the delivery of mental health care.

Major Depressive Disorder↗
PubMed2006

The educational impact of a computer-based training tutorial on dementia in long term care for licensed practice nursing students.

The purpose of this study was to examine whether training with a multimedia tutorial would have an impact on LPN students' knowledge of dementia care, attitudes toward dementia care, and self-efficacy ratings. A total of 38 nursing students participated. Pre-post comparisons of outcome measures revealed significant improvements in knowledge, attitudes, and self-efficacy ratings. Results of post-training satisfaction and usability questionnaires indicate that participants found the tutorials easy to understand and easy to use. These data support the effectiveness of the dementia tutorial and the use of computer-based training in educating our long-term care workforce.

Adult↗
PubMed2006

A randomized controlled trial of outreach placement's effect on dental students' clinical confidence.

This randomized controlled trial compared the effects of outreach placement with traditional, exclusively dental school-based clinical experience on students' confidence in providing treatment for patients presenting with common dental problems. Senior dental students (n=49) were allocated at random to existing dental school-based clinics or placement in primary care clinics to work supervised by local dentists. At baseline, students self-rated their global confidence on a five-point scale. These measures were repeated at follow-up, augmented by a transition judgment and a then-test of confidence (asking students to look back and re-rate their pre-placement confidence). Groups were comparable at baseline. Follow-up scores for global confidence were similar between groups. The outreach group scored higher in the transition judgment (mean 3.7, SD 0.9) than the control group (mean 3.1, SD 1.1, P=0.05). In the then-test, on reflection, the outreach group considered their baseline ratings of confidence were overoptimistic (mean then-test scores 3.2, SD 0.9 and baseline 3.7, SD 0.5) while the control group thought theirs were accurate (mean then-test scores 3.8, SD 0.7 and baseline 3.6, SD 0.8, P=0.01). The findings suggest dental outreach training in primary care settings is more effective than dental school training alone in improving students' confidence in tackling clinical situations. The measurement of change in confidence is complicated by shifts in students' internal scales arising from insights gained on outreach.

Attitude of Health Personnel↗
PubMed2005

Web GIS in practice II: interactive SVG maps of diagnoses of sexually transmitted diseases by Primary Care Trust in London, 1997 - 2003.

BACKGROUND: The rates of Sexually transmitted diseases (STDs) in England have been rising steadily since the mid 1990s, making them a major public health concern. In 2003, 672,718 people were diagnosed with an STD in England, and around one third of those cases were diagnosed in London. RESULTS: Using GeoReveal v1.1 for Windows, we produced Web-based interactive choropleth maps of diagnoses of STDs by Primary Care Trust (PCT) in London for the years from 1997 to 2003 http://healthcybermap.org/PCT/STDs/. These maps are in Scalable Vector Graphics (SVG) format and require a freely available Adobe SVG browser plug-in to be displayed. They are based on data obtained from the House of Commons Hansard Written Answers for 15 October 2004. They show steadily rising rates of STDs in London over the covered seven-year period. Also, one can clearly see on the maps that PCTs located in central London had the highest numbers of STD diagnoses throughout the mapped seven years. A companion bar chart allows users to instantly compare the STD figure of a given PCT for a given year against the average figure for all 25 mapped PCTs for the same year, and also compare those figures across all seven years. The maps offer users a rich set of useful features and functions, including the ability to change the classification method in use, the number of ranges in the map, and the colour theme, among others. CONCLUSIONS: Wizard-driven tools like GeoReveal have made it very easy to transform complex raw data into valuable decision support information products (interactive Web maps) in very little time and without requiring much expertise. The resultant interactive maps have the potential of further supporting health planners and decision makers in their planning and management tasks by allowing them to graphically interrogate data, instantly spot trends, and make quick and effective visual comparisons of geographically differentiated phenomena between different geographical areas and over time.SVG makes an ideal format for such maps. SVG is a World Wide Web Consortium non-proprietary, XML-based vector graphics format, and is an extremely powerful alternative to Macromedia(R) Flash and bitmap graphics.

Journal Article↗
PubMed2005

Sorghum genome sequencing by methylation filtration.

Sorghum bicolor is a close relative of maize and is a staple crop in Africa and much of the developing world because of its superior tolerance of arid growth conditions. We have generated sequence from the hypomethylated portion of the sorghum genome by applying methylation filtration (MF) technology. The evidence suggests that 96% of the genes have been sequence tagged, with an average coverage of 65% across their length. Remarkably, this level of gene discovery was accomplished after generating a raw coverage of less than 300 megabases of the 735-megabase genome. MF preferentially captures exons and introns, promoters, microRNAs, and simple sequence repeats, and minimizes interspersed repeats, thus providing a robust view of the functional parts of the genome. The sorghum MF sequence set is beneficial to research on sorghum and is also a powerful resource for comparative genomics among the grasses and across the entire plant kingdom. Thousands of hypothetical gene predictions in rice and Arabidopsis are supported by the sorghum dataset, and genomic similarities highlight evolutionarily conserved regions that will lead to a better understanding of rice and Arabidopsis.

Arabidopsis↗
PubMed2005

ATM sequence variants are predictive of adverse radiotherapy response among patients treated for prostate cancer.

PURPOSE: To examine whether the presence of sequence variants in the ATM (mutated in ataxia-telangiectasia) gene is predictive for the development of radiation-induced adverse responses resulting from (125)I prostate brachytherapy for early-stage prostate cancer. MATERIALS AND METHODS: Thirty-seven patients with a minimum of 1-year follow-up who underwent (125)I prostate brachytherapy of early-stage prostate cancer were screened for DNA sequence variations in all 62 coding exons of the ATM gene using denaturing high-performance liquid chromatography. The clinical course and postimplant dosimetry for each genetically characterized patient were obtained from a database of 2,020 patients implanted at Mount Sinai Hospital after 1990. RESULTS: Twenty-one ATM sequence alterations located within exons, or in short intronic regions flanking each exon, were found in 16 of the 37 patients screened. For this group, 10 of 16 (63%) exhibited at least one form of adverse response. In contrast, of the 21 patients who did not harbor an ATM sequence variation, only 3 of 21 (14%) manifested radiation-induced adverse responses (p = 0.005). Nine of the patients with sequence alterations specifically possessed missense mutations, which encode for amino acid substitutions and are therefore more likely to possess functional importance. For this group, 7 of 9 (78%) exhibited at least one form of adverse response. In contrast, of the 28 patients who did not have a missense alteration, only 6 of 28 (21%) manifested any form of adverse response to the radiotherapy (p = 0.004). Of the patients with missense variants, 5 of 9 (56%) exhibited late rectal bleeding vs. 1 of 28 (4%) without such alterations (p = 0.002). Of those patients who were at risk for developing erectile dysfunction, 5 of 8 (63%) patients with missense mutations developed prospectively evaluated erectile dysfunction as opposed to 2 of 20 (10%) without these sequence alterations (p = 0.009). CONCLUSIONS: Possession of sequence variants in the ATM gene, particularly those that encode for an amino acid substitution, is predictive for the development of adverse radiotherapy responses among patients treated with (125)I prostate brachytherapy.

Aged↗
PubMed2005

Urea cycle disorders: clinical presentation outside the newborn period.

Although most commonly associated with infancy, the majority of individuals with urea cycle disorders (UCDs) present outside the neonatal period, frequently in childhood. Signs and symptoms are often vague, but recurrent; fulminant presentations associated with acute illness are also common. A disorder of urea cycle metabolism should be considered in children who have recurrent symptoms, especially neurologic abnormalities associated with periods of decompensation. Routine laboratory tests, including measurement of plasma ammonia concentrations, can indicate a potential UCD; however, specific metabolic testing and ultimately enzymatic or molecular confirmation are necessary to establish a diagnosis. Treatment with dietary protein restriction and medications may be challenging in children.

Age of Onset↗
PubMed2005

Detection and measurement of alternative splicing using splicing-sensitive microarrays.

Splicing and alternative splicing are major processes in the interpretation and expression of genetic information for metazoan organisms. The study of splicing is moving from focused attention on the regulatory mechanisms of a selected set of paradigmatic alternative splicing events to questions of global integration of splicing regulation with genome and cell function. For this reason, parallel methods for detecting and measuring alternative splicing are necessary. We have adapted the splicing-sensitive oligonucleotide microarrays used to estimate splicing efficiency in yeast to the study of alternative splicing in vertebrate cells and tissues. We use gene models incorporating knowledge about splicing to design oligonucleotides specific for discriminating alternatively spliced mRNAs from each other. Here we present the main strategies for design, application, and analysis of spotted oligonucleotide arrays for detection and measurement of alternative splicing. We demonstrate these strategies using a two-intron yeast gene that has been altered to produce different amounts of alternatively spliced RNAs, as well as by profiling alternative splicing in NCI 60 cancer cell lines.

Alternative Splicing↗
PubMed2005

Fusarium sporodochia on cutaneous wounds.

A histopathological review of 24 cases of Fusarium-spp. culture-positive human specimens reveal sporodochia in eight cases, all of which were cutaneous injuries. These included three patients with burn wounds, three patients with ischemic necrosis, one patient who suffered trauma with extensive contamination of the injury with vegetation, and one patient with an ischemic skin graft placed for treatment of a non-healing traumatic leg injury sustained in a motor vehicle-pedestrian accident. Sporodochia consisted of swollen cells giving rise to parallel-oriented hyphae that extended upward above the surface, giving rise to a carpet of conidia on its uppermost aspect. Sporodochia have not been previously reported in humans. The presence of Fusarium sporodochia has implications with respect to infection control, as clinical care practices must be tailored to minimize potential aerolization of conidia, chlamydospores and rare budding cells, with resultant spread of the fungus during surgical manipulation, bandage change or cleaning of cutaneous wounds.

Dermatomycoses↗