Biomedical subjects

Paul Baker

Publications and source records attributed to Paul Baker.

10 recordsLinked to original sources

PubMed2007

Portable 24-analyte surface plasmon resonance instruments for rapid, versatile biodetection.

Field use of surface plasmon resonance (SPR) biosensors for environmental and defense applications such as detection and identification of biological warfare agents has been hampered by lack of rugged, portable, high-performance instrumentation. To meet this need, we have developed compact multi-analyte SPR instruments based on Texas Instruments' Spreeta sensing chips. The instruments weigh 3 kg and are built into clamshell enclosures measuring 28 cm x 22 cm x 13 cm. Functions are divided between an electronics unit in the base of the box and a fluidics assembly in the lid. Automated valves and pumps implement an injection loop flow system that allows sensors to be exposed to sample, rinsed, and treated with additional reagents (such as secondary antibodies) under computer control. Injected samples flow over the surfaces of eight sensor chips fastened into a temperature-controlled silicone flowcell. Each chip has 3 sensing regions, for a total detection of 24 areas that can be simultaneously monitored by SPR. Coating these areas with appropriate antibodies or other receptors allows a sample to be screened for up to 24 different substances simultaneously. The instruments report refractive index (RI) values every second, with a typical noise level of 1-3 x 10(-6) RI units. The design of the device is described, and performance is illustrated with detection of six distinct analytes ranging from small molecules to whole microbes during the course of a single experiment.

Biological Warfare↗

PubMed2006

Immediate and early replacement implants and restorations.

UNLABELLED: There have been rapid developments in dental implant treatment protocols to reduce the time between implant placement and restoration. Implants may be placed immediately following tooth extraction or following a period of healing to allow resolution of residual infection or sufficient bone and soft tissue healing. Early restoration and loading of implants has to be carefully controlled to avoid increased failure and complications. Advantages and disadvantages of the various techniques are described. CLINICAL RELEVANCE: The clinician should adopt a treatment protocol that ensures a high success rate and a long-term functional and aesthetic implant restoration. Rapid treatment protocols can be considered when they do not compromise these goals, and the clinician is sufficiently experienced in their application.

Dental Implantation, Endosseous↗

PubMed2006

A framework for providing telecommuting as a reasonable accommodation: some considerations on a comparative case study.

Telecommuting, whether full time, part time, or over short periods when the need arises, can be an important accommodation for employees with disabilities. Indeed, telecommuting may be the only form of accommodation that offers employees whose disabilities fluctuate a means to stay consistently and gainfully employed. This article describes one employer's experience in considering a request for telecommuting as a reasonable accommodation for a particular employee. Drawing on real-life examples, both positive and negative, this article provides a win/win framework for decision-making that can help employers evaluate the use of telecommuting as a possible accommodation and facilitates open and ongoing communication between employer and employee.

Persons with Disabilities↗

PubMed2005

Self-assembling porphyrin-modified peptides.

[structure: see text] We report the synthesis and characterization of a novel supramolecular assembly that features long-range electronic coupling between porphyrins covalently attached to a designed peptide scaffold. The resulting construct self-assembles to form extended organized aggregates in which the porphyrins engage in exciton coupling.

Hydrogen-Ion Concentration↗

PubMed2005

Identification and validation of risk factors for vesicourethral leaks following radical retropubic prostatectomy.

AIMS: To identify risk factors for anastomotic leaks at cystography following radical retropubic prostatectomy (RRP). METHODS: In phase 1 the records of a 107 RRP patients were reviewed. Data collected included comorbidity, pathological factors and intra- and postoperative complications. From these, risk factors were identified that were associated with a leak at cystography. In phase 2 (n = 46) we prospectively tested if the risk factors identified could predict an anastomotic leak. RESULTS: In phase 1 the only identifiable risk factors were that of a difficult anastamosis, an unsatisfactory intraoperative test flush and the presence of a urinary tract infection. One or more of these events were found in 17/25 (68%) of the patients who leaked (P < 0.0001). Of the eight leaks missed, five were classed as minimal and did not require repeat cystography. Within the prospective phase 2 cohort one or more risk factors were present in 7/10 (70%) of the patients who leaked. In contrast, the identified risk factors were present in only 5/36 (13.8%) of the patients who did not leak (P < 0.001). The specificity of the test was 86.1% with a sensitivity of 70%. This gave a positive predictive value of 58.3% and a negative predictive value of 91.1%. Three leaks (two minimal and one moderate) would have been missed but 31 (67.3%) patients would have avoided an unnecessary radiological study. CONCLUSION: Using a retrospective and prospective cohort of patients we have shown that a cystogram following RRP can be safely avoided in the absence of the identified risk factors.

Anastomosis, Surgical↗

PubMed2004

Usefulness of core roll preparations in immediate assessment of neoplastic lung lesions: comparison to conventional CT scan-guided lung fine-needle aspiration cytology.

INTRODUCTION: CT scan-guided fine-needle aspiration (FNA) of lung nodules is a well-established diagnostic technique. In our institution, both FNA and tissue core biopsy (using a 20-gauge needle) under CT scan guidance are routinely performed during the same procedure, and a preliminary diagnosis (an immediate assessment) is rendered. We compared core roll preparations (CRPs) with aspirate smears in the immediate assessment of pulmonary lesions and also assessed whether CRP resulted in the alteration of the histopathology of the core biopsy. STUDY DESIGN: Twenty-five cases of neoplastic pulmonary lesions diagnosed in CT scan-guided lung FNA specimens, with core biopsies performed sequentially at the same visit for each patient, were evaluated. CRPs were made by lightly rolling the tissue core on a glass slide, followed by air-drying. Only stained slides (Diff-Quik; Mercedes Medical; Sarasota, FL) were reviewed, and were scored for cellularity and morphology. RESULTS: CRPs in seven cases (28%) scored more diagnostic points than FNA smears, and were found to be better for cellularity and morphology compared to the corresponding FNA smears. The FNA smears scored more than CRPs in 10 cases (40%), while in 8 cases (32%) both CRPs and FNA smears scored equal diagnostic points. Using both CRP and FNA smears in the immediate assessment of lung biopsy specimens, we could assign a specific malignant histologic cell type in 23 of 25 cases (92%). In comparison, if the FNA smears were evaluated alone, we could assign a specific malignant histologic cell type in only 16 of 25 cases (64%). The CRP did not alter the histopathology of the core biopsy specimens in any of the above cases. CONCLUSION: The CRP complements the CT scan-guided lung FNA procedure in the immediate assessment of neoplastic lung lesions without altering the histopathology of core biopsy specimens.

Adult↗

PubMed2003

The development and validation of a neuropathy- and foot ulcer-specific quality of life instrument.

OBJECTIVE: The purpose of this study was to develop a questionnaire that measures patients' perceptions of the impact of diabetic peripheral neuropathy and foot ulcers on their quality of life and to assess the psychometric properties of this instrument in a sample of patients with varying severity and symptomatology of diabetic peripheral neuropathy. RESEARCH DESIGN AND METHODS: The neuropathy- and foot ulcer-specific quality of life instrument (NeuroQoL), generated from interviews with patients with (n = 47) and without (n = 15) diabetic peripheral neuropathy, was administered to 418 consecutive patients with diabetic peripheral neuropathy (35% with foot ulcer history) attending either U.K. (n = 290) or U.S. (n = 128) diabetes centers. Psychometric tests of NeuroQoL included factor analyses and internal consistency of scales; a series of multivariate analyses were performed to establish its criterion, construct, and incremental validity. Results were compared with those obtained using the Short Form (SF)-12 measure of health-related functioning. RESULTS: Factor analyses of NeuroQoL revealed three physical symptom measures and two psychosocial functioning measures with good reliability (alpha = 0.86-0.95). NeuroQoL was more strongly associated with measures of neuropathic severity than SF-12, more fully mediated the relationship of diabetic peripheral neuropathy with overall quality of life, and significantly increased explained variance in overall quality of life over SF-12. CONCLUSIONS: NeuroQoL reliably captures the key dimensions of the patients' experience of diabetic peripheral neuropathy and is a valid tool for studying the impact of neuropathy and foot ulceration on quality of life.

Aged↗

PubMed2002

The aetiology of gingival recession.

Gingival recession affects a large proportion of the adult population. This paper discusses the aetiology and mechanisms behind the formation of gingival recession, and considers the relevance of gingival recession to both orthodontics and restorative dentistry. It is followed by a second paper on the management of gingival recession.

Adult↗

PubMed2002

The management of gingival recession.

This, the second paper in a short series on gingival recession, discusses the various modalities of treatment for gingival recession and the indications for treatment. Special consideration is given to the surgical treatment techniques. Factors affecting the outcome of treatment and success rates of the treatment options are also discussed.

Connective Tissue↗

PubMed2002

Sports injury, occupational physical activity, joint laxity, and meniscal damage.

OBJECTIVE: To investigate the risk factors for meniscal damage, an important determinant of knee osteoarthritis. METHODS: We studied 243 men and women aged 20-59 years in whom the diagnosis of a meniscal tear was confirmed for the first time at arthroscopy, over a 25 month period, in 2 British hospitals. Each case was compared with one or 2 community controls, matched by age and sex, who were registered with the same general practitioner. Information on exposure to risk factors was obtained by a structured questionnaire and physical examination. RESULTS: Meniscal tear was strongly associated with participation in sports during the 12 months preceding the onset of symptoms; the risk was particularly high for soccer (OR 3.7; 95% CI 2.1-6.6). Higher body mass index and occupational kneeling (OR 3.8; 95% CI 1.3-11.0) and squatting (OR 2.9; 95% CI 1.0-8.0) were associated with an increased risk of degenerative meniscal lesions, after adjustment for social class, joint laxity, and sports participation. Joint laxity was associated with degenerative meniscal lesions independently of occupational physical activity, sports, and obesity. CONCLUSION: Our results confirm the importance of sporting activities entailing knee torsion in acute meniscal tear. They also point to a role for occupational activity, adiposity, and joint laxity in the pathogenesis of degenerative meniscal lesions. Modifying these mechanical risk factors may serve to reduce the risk of meniscal injury and may also help to prevent later knee osteoarthritis.

Adult↗