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Biomedical subjects

C Phillips

Publications and source records attributed to C Phillips.

At least 109 records · Page 6Linked to original sources

PDZ domains: targeting signalling molecules to sub-membranous sites.

PDZ (also called DHR or GLGF) domains are found in diverse membrane-associated proteins including members of the MAGUK family of guanylate kinase homologues, several protein phosphatases and kinases, neuronal nitric oxide synthase, and several dystrophin-associated proteins, collectively known as syntrophins. Many PDZ domain-containing proteins appear to be localised to highly specialised submembranous sites, suggesting their participation in cellular junction formation, receptor or channel clustering, and intracellular signalling events. PDZ domains of several MAGUKs interact with the C-terminal polypeptides of a subset of NMDA receptor subunits and/or with Shaker-type K+ channels. Other PDZ domains have been shown to bind similar ligands of other transmembrane receptors. Recently, the crystal structures of PDZ domains, with and without ligand, have been determined. These demonstrate the mode of ligand-binding and the structural bases for sequence conservation among diverse PDZ domains.

Amino Acid Sequence↗

A biomechanical study of the flexor digitorum superficialis: effects of digital pulley excision and loss of the flexor digitorum profundus.

Many reports have been devoted to characterizing the significance of the pulleys for the flexor digitorum profundus (FDP). However, no comparable work has been published on the flexor digitorum superficialis (FDS). This study characterized the FDS in a human cadaver model. Eleven fresh-frozen cadaver hands were used. By using a tensiometer, data were gathered for tendon excursion, tendon load, and work of flexion. Changes in efficiency were caused by excision of annular pulleys A1, A2, A3, and the palmar aponeurotic pulley. We also measured the effect of FDP excision on FDS efficiency. Sectioning of the A2 and A3 pulleys together caused statistically significant losses of efficiency in all three parameters (work, load, and excursion). When the FDP was removed from a finger with an intact pulley system, losses in both work and excursion efficiencies were significant. Removing the FDP while cutting different pulleys caused significant decrease in FDS excursion efficiency. We conclude that A2 and A3 are the most important pulleys for maintaining normal FDS function, and that the presence of the FDP in the digital sheath is essential for optimal FDS excursion efficiency.

Biomechanical Phenomena↗

Influences on the outcome of early treatment for Class II malocclusion.

In the first phase of a randomized clinical trial of early versus late Class II treatment, statistically significant differences were observed between the treatment and observation groups. However, there were wide variations in response. The change in jaw relationship (categorized as the annualized reduction in ANB angle) was favorable or highly favorable in 76% of the headgear, 83% of the functional appliance, and 31% of control (observation only) groups. The patient's initial skeletal severity, age/maturity at the outset of treatment, growth pattern, and cooperation with treatment were examined as possible influences on early growth modification treatment. Correlations between the annualized change in the ANB angle and any of the possible influences were close to zero and not statistically significant. We conclude that there is little to be gained from precisely timing early treatment to specific age/maturity markers and that a favorable reduction in Class II skeletal problems can occur for patients in a broad range of skeletal severity and growth patterns. Cooperation, measured as the number of hours of reported wear, or the clinical assessment of compliance, explained little of the variation in treatment response. The wide variation in growth seen in the untreated patients highlights the importance of well-controlled studies if clinicians are to improve their ability to select children with the greatest chances of a favorable treatment response.

Activator Appliances↗

The effect of early intervention on skeletal pattern in Class II malocclusion: a randomized clinical trial.

Early treatment for Class II malocclusion is frequently undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. Because the majority of previous studies of growth modification for Class II malocclusion have been based on retrospective record reviews, the efficacy of such an approach has not been well established. In this controlled clinical trial, patients in the mixed dentition with overjet > or = 7 mm were randomly assigned to either early treatment with headgear, or modified bionator, or to observation. All patients were observed for 15 months with no other appliances used during this phase of the trial. The three groups, who were equivalent initially, experienced statistically significant differences (p < 0.01) in skeletal change. There was considerable variation in the pattern of change within all three groups, with about 80% of the treated children responding favorably. Although patients in both early treatment groups had approximately the same reduction in Class II severity, as reflected by change in the ANB angle, the mechanism of this change was different. The headgear group showed restricted forward movement of the maxilla, and the functional appliance group showed a greater increase in mandibular length. The permanence of these skeletal changes and their impact on the subsequent treatment remains to be evaluated.

Analysis of Variance↗

Changes in hospitalization associated with introducing the Resident Assessment Instrument.

OBJECTIVE: To compare the rates of hospitalization among cohorts of nursing home residents assembled before and after the implementation of the federally mandated Resident Assessment Instrument (RAI). SAMPLE: Subjects were nursing home residents chosen from 268 facilities in major Metropolitan Statistics Areas in 10 states and representing more than 1500 facilities and 60,000 residents. Two resident cohorts (1990 and 1993) were sampled (8 to 16 residents per facility, depending upon facility size) as part of an evaluation of the impact of implementing the RAI. METHODS: Research nurses reviewed records, interviewed staff, observed patients, and completed an RAI at baseline and 6 months later. All transitions during this interval (hospital admissions, nursing home transfers, returns home, death, etc.) were tracked. Using polytomous logistic regression, we tested the effect of cohort on the probability of being hospitalized in light of the competing risks of dying or remaining in the home, controlling for demographic and casemix variables, and having a DNR order in the chart. RESULTS: A total of 4196 residents were studied, 2118 in 1990 (age 81.3, female 77.7%, LOS 6+ months 49.8%) and 2078 in 1993 (age 81.7, females 75.5%, LOS 6+ months 50.2%). The unadjusted probability of hospitalization dropped from .205 to .151. Multivariate analyses revealed a significant adjusted odds of hospitalization of .74 (95% CI .60-.91) and no cohort effect on home discharge or death. Among severely cognitively impaired residents, the adjusted odds of hospitalization in 1993 compared with the 1990 cohort was 0.74 (.53-1.03). Finally, among survivors in both cohorts who had a follow-up MDS performed, and whose ADL remained stable, 15.9% were hospitalized in 1990, whereas only 10.9% were hospitalized in 1993. On the other hand, ADL decliners were more likely to have been hospitalized in 1993 than in 1990 (40.6% vs 25.2%). CONCLUSIONS: Although other changes in the industry, clinical practice, and health care policy may have influenced hospitalization of nursing home residents, the substantial reductions observed among the cognitively impaired and those with stable ADL suggest superior and uniform assessment information in the form of the RAI contributed significantly to this decline.

Activities of Daily Living↗

A commitment to change: revision of HCFA's RAI.

OBJECTIVE: To describe the reliability of new assessment items and their clinical utility as judged by experienced nurse assessors, based on the results from the field test of Version 2.0 of the Resident Assessment Instrument (RAI). DESIGN: Independent dual assessment of residents of nursing facilities by staff nurses using a draft of Version 2.0 of the minimum data set (MDS). SETTING AND PARTICIPANTS: A total of 187 randomly selected residents from 21 nursing homes in seven states volunteered to test Version 2.0 of the MDS. MEASUREMENT: The full array of MDS assessment items included measures in the following areas: Background information, cognitive patterns, communication/hearing, vision, mood and behavior, psychosocial well-being, physical functioning and structural problems, continence, disease diagnoses, health condition, oral/nutritional status, dental status, skin condition, activity pursuit patterns, medications, special treatments and procedures, and discharge potential and overall status. RESULTS: Evaluative data address issues of MDS item utility and reliability. For new items, almost all achieved a reasonably high-weighted Kappa interrater reliability; revised items also surpassed earlier items, and with the updated training materials, even the non-changed items had higher average reliability levels. Based on the success of the field test and the positive response of the industry, Version 2.0 of the RAI has been adopted, and HCFA has initiated a more long-range process to update further the RAI when necessary. CONCLUSION: Findings support the reliability and clinical utility of the new and revised assessment items incorporated by HCFA in Version 2.0 of the MDS.

Activities of Daily Living↗

Measuring beliefs about orthodontic treatment: a questionnaire approach.

OBJECTIVES: Few studies have examined what parents and orthodontists expect from and value about orthodontic treatment. In this study, we designed and tested a questionnaire to outline what drives consumer demand for children's orthodontic care. Further, we present data from the questionnaire to illustrate how expectations and values pertaining to orthodontic treatment relate to sociodemographic variables. METHODS: Subjects were 220 Pennsylvania orthodontists and 220 parents at a university orthodontic clinic who were administered a questionnaire designed to assess what parents and orthodontists value about and expect from orthodontic treatment. Items for the questionnaire were developed via a qualitative, telephone interview process. Data were analyzed using factor analysis and reliability analysis for scale development, and analysis of variance for preliminary validity assessment. RESULTS: Through factor analysis, the questionnaire was reduced from 84 to 52 items, and eight scales were examined: expected treatment benefits, expected treatment risks (short- and long-term), expected treatment inconveniences, value of treatment benefits, value of risks (short- and long-term), and value of treatment inconveniences. For parents, the reliability for all scales was in the acceptable range. For orthodontists, only the "short-term risks" scale failed to attain an acceptable reliability. Preliminary validity was assessed through examining relationships between demographic variables and subscale scores. For parents, income, father's education level, and sex of respondent were related to treatment expectations and values. For orthodontists, age, sex, and patient volume were related to treatment values. CONCLUSIONS: The questionnaire developed in the present study was found to be practical and reliable for use with providers and consumers of orthodontic care and can be used to explore factors affecting the demand for orthodontic care. Implications of possible unrealistic treatment expectations on the part of orthodontists and parents also are discussed.

Adolescent↗

A comparison of the use of sedatives in a hospital support team and in a hospice.

This study examines how frequently and for what indications sedatives are prescribed in a hospital support team and in a hospice. We also looked at the survival of sedated patients from the date of admission and from the start of sedation. Overall 26% of patients were prescribed sedatives in order to sedate them (31% at the hospice and 21% at the hospital) and 43% of patients were given sedatives for symptom control (67% at the hospice and 21% at the hospital). Sedated patients survived for a mean of 1.3 days after the start of sedation, and there was no detectable difference in survival from the date of admission between sedated and nonsedated patients.

Adult↗

Treatment of chronic rotator-cuff impingement by arthroscopic subacromial decompression.

We report a prospective study of 49 patients who had arthroscopic subacromial decompression for chronic rotator-cuff impingement. All patients were assessed preoperatively and at 3, 6 and 12 months using the modified UCLA shoulder score. The dominant arm was affected in 35 patients, but only 13 recognised overuse as a cause of their shoulder pain. Before operation, the UCLA shoulder score was poor or fair in all patients. After three months only 28% of patients had satisfactory relief of symptoms but at one year 85% of patients examined had a good or excellent result. Patients with calcific tendonitis recovered more quickly: 93% reported a good result at six months. We conclude that arthroscopic subacromial decompression is an effective form of treatment, but that patients should be warned that recovery from surgery may be prolonged.

Adult↗

Interviews with men with prostate cancer about their self-help group experience.

This study reports on the results of semi-structured interviews with 12 men involved in prostate cancer self-help groups in three Canadian cities. Overall, participants reported their group involvement to be helpful, especially in terms of accessing information. Additional benefits included finding commonality with others, being able to talk about difficult issues, being productive and accomplishing tasks, advocating to make a difference, and engaging with family members around health issues. We conclude that the recent growth of self-help groups speaks to the challenge inherent for men in dealing with prostate cancer and counteracts tendencies to minimize the suffering which they experience.

Adaptation, Psychological↗

The relevance of using tragal cartilage in tympanoplasty.

Chronic endotympanic depression is a pathological situation which leads to tympanic atelectasis, retraction pockets and cholesteatoma. It is also at the origin of tympanoplasty failure. Tragal composite perichondrium-cartilage graft is a procedure which gives good results in these difficult surgical cases.

Humans↗

A new staining method for identification of Helicobacter pylori and simultaneous visualization of gastric morphologic features.

Helicobacter pylori (HP) is prevalent in the general population and is associated with chronic active gastritis, peptic ulcers, gastric carcinoma, and lymphoma. Different methods to diagnose HP colonization include the urea breath test, serologic analysis, and gastric biopsy. Many different staining methods, including silver and Giemsa-based stains, have been used to demonstrate these organisms in gastric biopsy specimens. The tissue morphologic features, however, are often obscured, thus mandating evaluation of both hematoxylin and eosin (H&E) and special stains. This study evaluates the ability of a new staining method that allows simultaneous identification of HP and visualization of tissue morphologic features. We examined formalin-fixed, paraffin-embedded archival tissues from 184 consecutive gastric biopsy specimens using our new staining method, and we compared our results with those previously obtained from H&E and Warthin-Starry (WS) stains. Our new stain uses periodic acid-Schiff, Coleman's Feulgen solution, Mayer's hematoxylin, and methylene blue. Our method is technically simpler than the WS stain and can be completed in approximately 9 minutes. We found HP organisms in 76 (41%) of 184 biopsy specimens by H&E and/or WS staining. Our new staining method identified HP in 83 specimens (45%). The organisms stained bright blue and were easily visualized (compared with the H&E-stained specimens) because of the contrasting magenta mucin. Tissue morphologic features consisted of well-defined cells with dark blue nuclei and pale cytoplasm. Intestinal metaplasia was highlighted magenta Our new staining method revealed chronic active gastritis in 71 cases (39%), intestinal metaplasia in 18 cases (10%), and lymphoid aggregates in 35 cases (19%). These findings were similar to the results obtained with H&E-stained sections. We conclude that our new staining method is inexpensive, quick, and easy to perform and interpret. It has a sensitivity comparable to that of conventional staining methods and simultaneously demonstrates both tissue morphologic features and the presence of HP.

Biopsy↗

Dentofacial disharmony: motivations for seeking treatment.

Patients whose skeletal disharmony was severe enough to warrant a surgical treatment option completed a 24-item Motives for Treatment questionnaire. Each item was rated from (1) not at all a reason to (4) very much a reason. Items were grouped to form six dimensions. An average score of 3.0 or greater on a given dimension was considered a strong motivation. Of the 135 patients who completed the questionnaire, 16% of the patients had primarily a self-image motivation, 4% primarily an oral function motivation, and 6% strong dual self-image/oral function motivations. Males and females differed significantly on the social well-being and temporomandibular joint (TMJ) dimensions. A strong social motivation occurred 4.5 times more frequently among males than among females, while a higher proportion of females than males reported TMJ concerns. Patients older than 25 scored higher on oral function, future health, and TMJ dimensions. Patients who elected surgery had higher scores on oral function, nasal function, and TMJ dimensions. Approximately 1.5 times as many patients who elected surgery scored on average of 3.0 or higher on the self-image and oral function dimensions.

Adolescent↗

Risk factors for developing tooth sensitivity and gingival irritation associated with nightguard vital bleaching.

The purpose of this study was to determine risk factors in the development of tooth sensitivity and gingival irritation associated with the nightguard vital bleaching technique. The potential risk factors evaluated (sex, age, reported allergy, whitening solution, number of times the solution was changed daily [its usage pattern], and dental arch) were collected from the daily log form turned in by each of the 64 participants after completion of the 6-week lightening process. Also evaluated for each participant, from color slides, were tooth characteristics such as gingival recession, defective restorations, abfraction lesions, enamel-cementum abrasion, etc, and reported side effects. The generalized Mantel-Haenszel statistic was used to assess the association between the potential risk factors and the development of tooth sensitivity and/or gingival irritation. No statistical relationship existed between age, sex, allergy, tooth characteristics, or the dental arch lightened and the development of side effects. Initially, a statistically significant association existed between side effects and the whitening solution used. However, when the analysis was controlled for usage pattern, this relationship disappeared. Patients who changed the whitening solution more than once a day reported statistically significantly more side effects than did those who did not change the whitening solution during their usage time.

Acrylic Resins↗