Search PubMed⌕ Search

Biomedical subjects

C Phillips

Publications and source records attributed to C Phillips.

At least 55 records · Page 3Linked to original sources
PubMed1999

Patients' perception of recovery after third molar surgery.

PURPOSE: This study evaluated patients' perceptions of recovery after third molar surgery. METHODS: Two hundred forty-nine patients (age 13 to 37 years) at 2 clinical centers were enrolled in a prospective study before the surgical removal of third molars. Each patient was given a 21-item Health-Related Quality of Life instrument (HRQOL) to be completed each postoperative day (POD) for 14 days. The instrument was designed to assess patients' perception of recovery: pain, oral function, general activity measures, and other symptoms. Pain dimensions were recorded with a 7-point Likert-type scale; all other conditions were measured on 5-point Likert-type scales. The impact of each predictor variable such as age, gender, and length of surgery on recovery was assessed with Cochran-Mantel-Haenszel statistics, controlling for clinical center. RESULTS: After the 14-day postoperative period, 201 of the original 249 patients returned the completed HRQOL instrument; the 48 patients who did not return their diary had third molar conditions and surgery similar to the 201 patients who responded. On POD 1, 63.5% of patients reported their worst pain as severe (score, 5 to 7/7) at some time during the day. By POD 7, only 15% of patients reported their worst pain as severe. Average pain levels were much less; 29% reported their average pain as severe (score, 5 to 7/7) on POD 1, decreasing to 5.5% by POD 7. Patients experienced substantial interference in oral function; chewing, 85%; mouth opening 78.5%, and speaking 37.5% on POD 1. By POD 6, oral function had improved; chewing, 19%, mouth opening, 15%; and speaking, 1.5%. General measures also were affected on POD 1; social activity, 61.5%; recreation, 70.5%; and daily routine, 60%. Patients assumed a more normal lifestyle by POD 5. Swelling seemed to be at its maximum on PODs 1 and 2 (day 1, 53%; day 2, 61%) and decreased markedly by POD 5 (10%). Food collection in the surgical sites posed the biggest problem for patients on POD 9 (20%). Age was not a predictor of prolonged recovery. However, surgery time 30 minutes or longer, or having all third molars below the occlusal plane, did prolong recovery. Females also reported a longer recovery period. CONCLUSIONS: This information is valuable to patients deciding on third molar surgery and to clinicians providing informed consent.

Adolescent↗
PubMed1999

Patient-centered outcomes in surgical and orthodontic treatment.

Patient-centered health care has two characteristics: it is closely congruent with and responsive to the patient's wants, needs, and preferences, and it considers the psychological, social, cultural, and economic dimensions of the patient in addition to physical findings. The ultimate benefit to the patient has always been a primary concern of clinicians providing coordinated orthodontic and orthognathic surgical treatment. However, in the past 10 years, a much greater emphasis has been placed in both medicine and dentistry on the patient as a coparticipant in decision making and the process of treatment. In addition, it has been realized the success of treatment must be defined not just in terms of the objective findings of clinicians, but also in the context of the patient's perceptions of what was achieved. This article discusses the impact of the new emphasis on patient-centered care on clinical practice and research in orthodontics and orthognathic surgery and provides two examples of how patient-centered outcomes can be assessed and used to improve the quality of care in these patients.

Humans↗
PubMed1999

Surgical versus orthodontic correction for Class II patients: age and severity in treatment planning and treatment outcome.

Treatment options for Class II malocclusion include orthognathic surgery. Treatment choices are particularly difficult for young patients because of the uncertainty regarding future growth. Surgical treatment has generally been considered necessary for older patients with more severe Class II problems. The treatment records of more than 500 patients with Class II malocclusion were reviewed. Patients were grouped according to their initial treatment plan (surgery or orthodontics) and treatment outcome (overjet [OJ] reduced to < 4 mm or not). Discriminant function analyses using data from the patient's pretreatment cephalogram were used to determine whether age, in combination with malocclusion severity, could predict the choice of treatment, and whether a simple set of pretreatment variables could predict the success or failure of OJ reduction. The derived equations were tested in a similar group of growing Class II children. Although the data showed clinicians use patient's age in determining treatment choice, age did not seem to be associated with treatment outcome. The majority of the variability that determined the success or failure of OJ reduction was not explained by patient's age or malocclusion severity. These findings suggest other factors, including psychosocial variables, need to be explored if we are to gain a better understanding of why treatments succeed or fail.

Adolescent↗
PubMed1999

Clinical and in vitro film quality comparison of manual and automatic exposure control in panoramic radiography.

OBJECTIVE: Automatic exposure control has been used successfully in medicine to improve image quality and reduce the number of retakes necessitated by inadequate operator selection of exposure factors. The purpose of this study was to assess the influence of automatic exposure control on panoramic image quality. STUDY DESIGN: A total of 352 patients were imaged with either the OP 100 or the Orthophos Plus panoramic machine. An expert consensus panel judged film quality using a 5-point scale. Differences in quality that would have resulted from the use of operator-determined exposures were calculated through use of an algorithm validated with test images of a human phantom. RESULTS: McNemar's test demonstrated significant improvements in quality with automatic exposure control (P = .001) in comparison with manual exposure control. No quality difference was found between the 2 machines (P = .9661). Manual exposure selection by oral and maxillofacial radiology residents was better than selection by technologists and assistants (P = .006). CONCLUSIONS: This study confirms the utility of automatic exposure control for panoramic radiography.

Adult↗
PubMed1999

Two- and three-dimensional imaging modalities for the detection of caries. A comparison between film, digital radiography and tuned aperture computed tomography (TACT).

OBJECTIVES: To compare the diagnostic performance provided by two- (film and digital radiography) and three-dimensional imaging modalities (TACT slices and TACT pseudoholograms) in the detection of primary caries. METHODS: Forty-two extracted human posterior teeth were mounted and imaged with conventional film and direct digital radiography. Free-hand positioning of a dental X-ray source was used for all exposures. From the digital images, iteratively restored TACT slices and TACT pseudoholograms were generated. Film images were viewed on a viewbox. Digital format images were viewed on a high-resolution monitor. Eight observers used a five-point scale to score the presence or absence of occlusal and proximal caries using the four image modalities. Observers' assessments were compared with the histological examination of tooth sections. Possible differences in ROC curve areas among image modalities, observers, and surfaces were assessed by ANOVA. Intra- and interobserver reliability as indicated by intraclass correlation was also calculated. RESULTS: There were no statistically significant differences between the diagnostic performances of film, digital radiography, TACT slices and TACT pseudoholograms in the detection of caries (P = 0.310). Intraclass correlation indicated the highest concordance both within and between observers when film was used for the evaluation. CONCLUSIONS: Under the experimental conditions of this study, three-dimensional TACT images did not improve caries detection over film or digital radiography. Further research should investigate the effects of imaging variables on TACT's diagnostic efficacy.

Analysis of Variance↗
PubMed1999

Cost-effectiveness of ondansetron for postoperative nausea and vomiting.

The decision as to whether prophylaxis against postoperative nausea and vomiting is better than treatment of established postoperative nausea and vomiting could be made on the basis of cost-effectiveness. The cost-effectiveness of ondansetron was calculated using data from published quantitative systematic reviews of randomised trials. Milligrams of ondansetron required to achieve a desired endpoint were chosen as a cost unit. Modelling was based on a cohort of 1000 patients, and examined control event rates (i.e. incidence of postoperative nausea and vomiting without prophylaxis) of between 10 and 90%. In a sensitivity analysis, cost-effectiveness of recommended intravenous doses (4 mg for treatment and prophylaxis) was compared with minimal effective doses as shown by meta-analysis (1 mg for treatment, 8 mg for prophylaxis). Fewer patients experience any postoperative nausea and vomiting symptoms with prophylaxis compared with treatment. But prophylaxis is only marginally more effective than treatment, and treatment of established postoperative nausea and vomiting with effective doses (i.e. 1 or 4 mg) is more cost-effective and safer than prophylaxis with effective doses (i.e. 4 or 8 mg). Reasons for this are the selective treatment of patients who actually need treatment, the high success rate with a lowest dose tested (1 mg) in established postoperative nausea and vomiting, and the disappointing antinausea effect of prophylactic ondansetron even at an eight-fold higher dose.

Antiemetics↗
PubMed1999

Job satisfaction amongst nurses in an interim secure forensic unit in Wales.

All grades of nursing staff in a recently established interim secure forensic unit completed the Index of Work Satisfaction (IWS; n = 40). High levels of job satisfaction were achieved on four of the IWS subscales: (i) professional status; (ii) interaction; (iii) doctor-nurse relationship; and (iv) autonomy. Moderate levels of satisfaction were found on two of the subscales, task requirements and administration, while the salary subscale was the major area of dissatisfaction across the group. The high level of overall satisfaction in this area of psychiatric nursing may be regarded as a significant achievement in the development of new clinical services in what is regarded as a stressful area of nursing. Measures of job satisfaction may be useful benchmarks for evaluating future changes and developments in the service and for monitoring and improving the clinical work environment.

Attitude of Health Personnel↗
PubMed1999

The effects of age and alcohol intoxication on simulated driving performance, awareness and self-restraint.

AIMS: To investigate whether, compared with middle-aged men (aged 30-50), older men (age > or =60) (i) perform more poorly on a driving simulator and (ii) are more sensitive to the effects of ethanol in terms of blood alcohol concentration (BAC) and driving performance, but more aware of their driving difficulties, and therefore exercise better driving judgement. METHODS: 14 Healthy middle-aged men (mean age 36 years) were compared with 14 healthy older men (mean age 69 years) on an interactive driving simulator, while sober and while legally intoxicated (BAC >80 mg/dl). RESULTS: Older age was associated with poorer driving performance on the simulator. While sober, older men exhibited more improper braking, slower driving, greater speed variability, fewer appropriate full stops and more crashes, and spent more time executing left turns (across oncoming traffic); all values < or =0.02. BACs > or =80 mg/dl were associated with impaired driving, with more inappropriate braking, fewer appropriate full stops and more time executing left turns (all values > or =0.02) and trends towards more speed variability, more low speed collisions and more wrong turns (values <0.1). However, similar ethanol consumption did not produce higher peak BAC or more driving impairments in older drivers. While there were no differences between age groups in terms of awareness of intoxication or driving difficulties, older men were unwilling to drive while legally intoxicated because of fear of physical injury, whereas middle-aged men were more likely to avoid driving when intoxicated due to fear of legal ramifications. CONCLUSION: While both age and legal intoxication affected driving performance, older men were no more sensitive to ethanol in terms of peak BACs, driving performance or awareness/judgement than middle-aged men.

Adult↗
PubMed1999

Boston University's biosciences education program for Boston-area students.

The authors describe the CityLab program, which has the goal of providing equal educational opportunities in biotechnology and medical sciences for all students in the greater Boston area in grades seven through 12, particularly students from groups traditionally underrepresented in science. Since 1992, more than 16,000 students and 1,200 teachers have participated in the program's activities, which focus on giving students meaningful laboratory experiences in the biosciences (either at Boston University of by means of a traveling laboratory in a bus). Students develop confidence in their ability to apply molecular biology and biotechnology concepts and skills to scientific problems and learn that they can pursue careers in the biosciences. The authors describe the CityLab program, its inquiry-based teaching methods, its effects, and its potential to increase students' interest in biomedical studies and careers.

Boston↗
PubMed1999

Skin pH changes associated with iontophoresis.

STUDY DESIGN: Randomized controlled trial. The researcher measuring skin pH was blinded to group assignment. OBJECTIVES: To compare the skin surface pH changes associated with iontophoresis. The investigation was designed to address the question of whether significant skin pH changes occur under the cathode on the skin surface when performing iontophoresis and assessed the influence of different electrode-buffering systems intended to stabilize skin pH (surface). BACKGROUND: Whether buffers are needed to stabilize skin pH during iontophoresis has not been thoroughly addressed in the literature. The effectiveness of immobile resins versus simple phosphate buffers is also unclear. METHODS AND MEASURES: Sixty volunteer subjects were administered iontophoresis of normal saline using buffered or nonbuffered electrode systems. Each subject participated in 1 of the 12 doses by electrode conditions (i.e., 5 subjects per group). Surface skin pH was measured before and after iontophoresis with a flat-surface pH electrode in concert with an analog pH meter. The independent variables were electrode type (4 levels) and dosage (3 levels). The dependent variable was the change in skin surface pH. RESULTS: A significant change in skin pH was found only when the treatment dose was 80 mA/minute with a nonbuffered electrode (x = 3.14 +/- 1.09). CONCLUSIONS: The skin pH changes that occur during a properly delivered iontophoresis treatment at dosages of 20 and 40 mA/min were small and not significantly different with or without the addition of buffers. Those pH changes associated with 80 mA/min doses were significantly greater when no buffer was employed but were stabilized by each of the buffers used in the study (preloaded immobile resins or simple phosphates added at point of treatment).

Adult↗
PubMed1999

Down syndrome and the phonological loop: the evidence for, and importance of, a specific verbal short-term memory deficit.

Individuals with Down syndrome are thought to perform poorly on tests of verbal short-term memory, such as measures of word span or digit span. This review critically examines the evidence for a specific deficit in verbal short-term memory in Down syndrome, and outlines a range of possible explanations for such a deficit. The potential implications of a verbal short-term memory impairment for broader aspects of development are outlined, in particular with respect to vocabulary development. Possible intervention strategies, which might improve verbal short-term memory performance in Down syndrome are also considered. However, we argue that further research is needed to fully clarify the nature of a verbal short-term memory deficit in Down syndrome, before the merits of these various intervention approaches can be properly evaluated.

Articulation Disorders↗
PubMed1999

A two-year study of microscopic urinalysis competency using the urinalysis-review computer program.

BACKGROUND: The microscopic examination of urine sediment is one of the most commonly performed microscope-based laboratory tests, but despite its widespread use, there has been no detailed study of the competency of medical technologists in performing this test. One reason for this is the lack of an effective competency assessment tool that can be applied uniformly across an institution. METHODS: This study describes the development and implementation of a computer program, Urinalysis-ReviewTM, which periodically tests competency in microscopic urinalysis and then summarizes individual and group test results. In this study, eight Urinalysis-Review exams were administered over 2 years to medical technologists (mean, 58 technologists per exam; range, 44-77) at our academic medical center. The eight exams contained 80 test questions, consisting of 72 structure identification questions and 8 quantification questions. The 72 structure questions required the identification of 134 urine sediment structures consisting of 63 examples of cells, 25 of casts, 18 of normal crystals, 8 of abnormal crystals, and 20 of organisms or artifacts. RESULTS: Overall, the medical technologists correctly identified 84% of cells, 72% of casts, 79% of normal crystals, 65% of abnormal crystals, and 81% of organisms and artifacts, and correctly answered 89% of the quantification questions. The results are probably a slight underestimate of competency because the images were analyzed without the knowledge of urine chemistry results. CONCLUSIONS: The study shows the feasibility of using a computer program for competency assessment in the clinical laboratory. In addition, the study establishes baseline measurements of competency that other laboratories can use for comparison, and which we will use in future studies that measure the effect of continuing education efforts in microscopic urinalysis.

Educational Measurement↗
PubMed1998

Report of the European DNA Profiling Group (EDNAP)--an investigation of the hypervariable STR loci ACTBP2, APOAI1 and D11S554 and the compound loci D12S391 and D1S1656.

This paper describes the results of three collaborative exercises which continues the EDNAP theme to explore whether uniformity of DNA profiling results could be achieved between European laboratories using STRs. In an earlier exercise, complex hypervariable AAAG-repeat STR loci were investigated, but reproducibility was found to be poor because of the variation of techniques used by participating laboratories. In the exercise reported here, an internal allelic ladder composed of ACTBP2 and D11S554 fragments was distributed. This ladder was used to size ACTBP2 analysed by a "singleplex" PCR amplification and D11S554 combined with APOAI1 in a separate "duplex" reaction. Laboratories were asked to test 7 blood stains, one of which was a known control, and to report the results to the co-ordinating laboratory. The exercise demonstrated that ACTBP2 showed good reproducibility between laboratories, whereas further testing would be needed to validate APOAI1 and D11S554 for interlaboratory comparisons. In separate exercises, the simple loci D12S391 and D1S1656 were tested; both of these showed excellent reproducibility between laboratories.

Alleles↗
PubMed1998

A 2.8 A resolution structure of 6-phosphogluconate dehydrogenase from the protozoan parasite Trypanosoma brucei: comparison with the sheep enzyme accounts for differences in activity with coenzyme and substrate analogues.

The three-dimensional structure of 6-phosphogluconate dehydrogenase (6PGDH) from the parasitic protozoan Trypanosoma brucei has been solved at 2.8 A resolution. This pentose phosphate pathway enzyme is NADP-dependent; NADPH generated in the reaction protects against oxidative stress. The enzyme crystallises in the space-group P3121 with a dimer in the asymmetric unit and cell dimensions a=b=135.13 A, c=116.74 A, alpha=beta=90 degrees, gamma=120 degrees. The structure has refined to R=18.6% (Rfree=27.3%) with good geometry. The amino acid sequence of T. brucei 6PGDH is only 35% identical to that of the sheep liver enzyme and significant activity differences have been observed. The active dimer assembles with the C-terminal tail of one subunit threaded through the other, forming part of the substrate binding site. The tail of T. brucei 6PGDH is shorter than that of the sheep enzyme and its terminal residues associate tightly with the second monomer. The three-dimensional structure shows this generates additional interactions between the subunits close to the active site; the coenzyme binding domain is thereby associated more tightly with the helical domain. Three residues, conserved in all other known sequences, are important in creating a salt bridge between monomers close to the substrate binding site. The differences could explain the 200-fold enhanced affinity observed for the substrate analogue 6-phospho-2-deoxy-D-gluconate and suggest targets for anti-parasite drug design. The coenzyme binding domain of 6PGDH has a beta-alpha-beta fold; while in most species the "fingerprint" sequence is GxAxxG, in the T. brucei enzyme it is GxGxxG. Additional interactions between the enzyme and the coenzyme bis-phosphate are likely in the parasite 6PGDH, accounting for greater inhibition (40-fold) of 2'5'-ADP. While the core of the T. brucei dimer was restrained during refinement, several conformational differences have been found between the monomers; those at the coenzyme binding site suggest the molecule could be asymmetric during the enzyme reaction.

Amino Acid Sequence↗
PubMed1998

Normal and anomalous electrophoretic behavior of polymerase chain reaction-based DNA polymorphisms in polyacrylamide gels.

The electrophoretic mobility of five single tandem repeats (STRs) and four amplified fragment length polymorphisms (AFLPs) in polyacrylamide gels was tested under denaturing and nondenaturing conditions. Relative anomalous mobility in nondenaturing conditions was found in one AT-rich AFLP (3'ApoB) and in two AT-rich STRs (HUMACTBP2 and HUMF13A1). In these cases, highly anomalous electrophoretic behavior was found even when changes were made in the %T value alone. In such cases typing results were affected by the gel composition. The mobility of these systems was nevertheless normal under denaturing conditions. As a consequence of this study, we recommended that the typing of these systems should only be performed under denaturing conditions and we also recommend the further study of the electrophoretic behavior of repetitive DNA polymorphisms, especially AT-rich systems, before they are used in forensic or genetic applications.

Acrylic Resins↗
PubMed1998

Bacterial reduction with nickel-titanium rotary instrumentation.

The purpose of this study was to compare intracanal bacterial reduction on teeth instrumented with 0.04 tapered nickel-titanium (NiTi) rotary instrumentation to bacterial reduction when using a stainless-steel K-file step-back technique using sterile saline irrigation. Forty-eight patients with apical periodontitis were randomly assigned treatment type. The canals were sampled before, during, and after instrumentation. The samples were incubated anaerobically for 7 days at 37 degrees C, colony-forming unit numbers calculated, and a log transformation performed to normalize the counts. Teeth exhibiting apical periodontitis were uniformly infected, whereas vital control teeth were not. A similar and uniform reduction occurred with progressive filing, regardless of technique (p < 0.0001). There was no detectable difference in colony-forming unit count after NiTi rotary or stainless-steel hand instrumentation (p = 0.42). Neither technique could predictably render canals free of bacteria. The results of this study indicate NiTi rotary and stainless-steel hand K-file step-back instrumentation techniques were not significantly different in their ability to reduce intracanal bacteria.

Analysis of Variance↗
PubMed1998

Effect of ion implantation of TMA archwires on the rate of orthodontic sliding space closure.

A split-mouth randomized clinical trial was used to determine whether ion implantation of beta-titanium archwire would facilitate sliding space closure. After bilateral maxillary first premolar extractions, 0.19 x 0.025-inch beta-titanium arch wires, ion-implanted on one half only, were placed in 30 subjects aged 10 to 42 years wearing unimplanted 0.022 inch slot appliances. Nickel-titanium springs (150 g) were placed bilaterally to close the extraction spaces. Space closure was measured intraorally at monthly intervals until either the space on one side closed or 6 months had elapsed. The median rates of space closure were not significantly different between the ion-implanted and the unimplanted sides. The average rate of space closure on these beta-titanium wires, with or without ion implantation, was similar to the rate reported on stainless steel arch wires.

Adolescent↗