Biomedical subjects

D L Fox

Publications and source records attributed to D L Fox.

At least 19 recordsLinked to original sources

PubMed1999

Air pollution.

Explore the source record for details and available documents.

Aerosols↗

PubMed1999

Reconstructing phylogeny with and without temporal data.

Conventional cladistic methods of inferring evolutionary relationships exclude temporal data from the initial search for optimal hypotheses, but stratocladistics includes such data. A comparison of the ability of these methods to recover known, simulated evolutionary histories given the same, evolved character data shows that stratocladistics recovers the true phylogeny in over twice as many cases as cladistics (42 versus 18 percent). The comparison involved 550 unique taxon-by-character matrices, representing 15 evolutionary models and fossil records ranging from 100 to 10 percent complete.

Biological Evolution↗

PubMed1999

Variability in the learning experiences of family practice residents during an obstetrics rotation.

BACKGROUND AND OBJECTIVES: Residency rotations do not necessarily provide the same clinical experience to each resident. This study quantified and explained the variability in participation in deliveries by family practice residents during an obstetrics rotation at a community hospital. METHODS: We collected prospectively completed resident experience logs from 17 residents and information from the hospital Summary of Delivery forms for 1,166 deliveries. The data were analyzed using methods to account for within-supervisor correlation. RESULTS: Participation and delivery rates varied markedly. In stepwise conditional regression analysis, resident participation in deliveries was positively associated with prior resident involvement during the labor and negatively associated with occurrence of the delivery on the night shift and with male gender of the resident. Resident performance of delivery was positively associated with non-instrumented vaginal delivery, prior resident involvement during the labor, and patient multiparity and negatively associated with male resident gender. CONCLUSIONS: We found substantial variability in resident experience and identified several factors associated with increased resident experience. Variability of experience among residents in clinical rotations should be assessed to ensure that all residents receive adequate training.

Adult↗

PubMed1998

Pilot study of a semi-flexible intra-oral appliance for the control of snoring.

OBJECTIVE: To determine the effectiveness and acceptability of an intra-oral appliance in the reduction of snoring, with construction and fitting as a 1-visit process. DESIGN AND SETTING: This was a prospective study. Patients were attending a hospital sleep breathing disorders clinic and appliances were made at a dental hospital. This work was carried out in the UK during 1996 and 1997. SUBJECTS AND METHODS: Patients were selected from those referred to a sleep breathing disorders clinic with socially disruptive snoring. MAIN OUTCOME MEASURES: Patients were assessed by means of limited sleep studies and by questionnaires before and after fitting of the appliances. The sleep studies consisted of monitoring respiratory variables (principally oronasal airflow and nocturnal oxygen saturation). A respiratory disturbance index was assigned. Questionnaires were completed by both patients and sleep partners, with many of the responses being marked on visual analogue scales. RESULTS: 16 male patients, mean age 49 years, were included in the trial. 14 were able to wear the appliance and their level of snoring, as assessed by their sleep partners, reduced from a mean of 8.8 out of 10 to 4.2 out of 10 (P = 0.0003, paired t-test). CONCLUSION: It is concluded that the semi-flexible intra-oral appliance is effective in the control of snoring.

Adult↗

PubMed1998

Analysis of change in arch form with premolar expansion.

The arch forms of 38 cases (53 nonextraction and 23 extraction arches) in which expansion, while maintaining arch form, was the objective of the practitioner, were analyzed before treatment, after treatment, and an average of 6 to 8 years after retention. The cubic spline was used to fit a curve representing arch form. By superimposing the spline curves, changes in arch form were analyzed with the variables rebound change (RC), rebound index (RI), rebound number (RN), and stability number (SN). Traditional linear intraarch dimensions were also analyzed. Analysis of variance was used to determine differences between the maxillary and mandibular arches and between the extraction and nonextraction cases. Pearson correlation coefficients between spline variables and arch width variables were also computed. There was significantly more expansion in the maxillary arch than the mandibular arch during treatment, irrespective of extraction or nonextraction strategies. In the nonextraction cases, a greater amount of net expansion was achieved for all dimensions for the maxillary arch as compared with the mandibular arch. Overall, a relatively high stability in arch form was found. The findings suggest that stability may not be related to the amount of change produced during treatment. Significant expansion can be gained throughout the premolar regions and may be expected to be stable. The order of greatest net arch width gained was for the second premolars followed by first premolars, molars, and then the canines. The intercanine widths for both arches decreased toward pretreatment values, but were more stable in the maxillary arch in nonextraction cases. The cubic spline permits measurement of change in arch form both during treatment and retention periods.

Analysis of Variance↗

PubMed1993

Case report: arthroscopic repair of a type IV SLAP lesion--the red-on-white lesion as a component of anterior instability.

This case report presents a rationale and technique for repair of a vascularized red-on-white bucket-handle tear of the glenoid labrum and intraarticular biceps tendon [type IV superior labrum anterior-to-posterior (SLAP) lesion]. This lesion may occur as a component of anterior instability, and as such it demands repair at the same time as anterior surgical stabilization for instability.

Acromioclavicular Joint↗

PubMed1993

Long-term evaluation of hip arthroplasty in patients with an ipsilateral knee arthrodesis.

Hip arthroplasty with an ipsilateral knee arthrodesis occurs infrequently but does raise concern regarding surgical technical difficulties, dislocation, sepsis, and long-term loosening. Sixteen patients were evaluated 7.5 years (average period) after surgery. Technical difficulties were not prohibitive. No dislocation or revision was necessary in any of the cases. Two patients died as a result of unrelated sepsis from an infected knee. Loosening and protrusio of the acetabulum occurred in two patients. Hip arthroplasty in patients with a fused knee does not incur undue risk of loosening or instability and can provide long-term good function and pain relief. Patients with multiple joint arthroplasties, in whom concurrent sepsis occurs, can have devastating results.

Arthrodesis↗

PubMed1992

SLAP lesions in association with complete tears of the long head of the biceps tendon: a report of two cases.

Two patients were found to have superior labrum anterior and posterior (SLAP) lesions in association with complete tears of the long head of the biceps. Additional intraarticular pathology (retained biceps stump, loose body, and glenoid chondromalacia) was discovered in one patient. We recommend arthroscopy of the shoulder in two situations associated with rupture of the long head of the biceps: (a) in patients with acute ruptures in which the decision has been made to do a biceps tenodesis; and (b) in patients with persistent longstanding shoulder symptoms following nonoperative management.

Adult↗

PubMed1987