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Biomedical subjects

C Farris

Publications and source records attributed to C Farris.

5 recordsLinked to original sources
PubMed1997

Observational evaluation of compliance with traffic regulations among helmeted and nonhelmeted bicyclists.

STUDY OBJECTIVE: To evaluate whether helmeted bicyclists are more compliant with traffic regulations than nonhelmeted bicyclists. METHODS: This prospective observational study, using a convenience sample, was conducted during daylight hours at three separate intersections, marked with legal stop signs, near the campus of a major university. Data collected included helmet use, legal hand signal use to indicate a turn or stop, and whether the bicyclist came to a complete stop before proceeding through the intersection. RESULTS: A total of 1,793 bicyclists were evaluated. Only 8.8% of the bicycle riders were wearing helmets. Helmeted bicyclists were 2.6 times more likely than nonhelmeted bicyclists to make legal stops (P < .000001; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.1 to 4.6). They were also 7.1 times more likely to use hand signals (P < .000001; OR, 7.2; 95% CI, 2.8 to 18.2). CONCLUSION: Helmeted bicycle riders showed a significantly greater compliance with two traffic laws than nonhelmeted bicyclists. They were 2.6 times more likely to stop at stop signs and 7.1 times more likely to use legal hand signals. This very strong association of helmet use with safer riding habits has implications for injury-control efforts aimed at preventing bicycle-related injuries.

Bicycling↗
PubMed1995

In vivo cancer diagnosis of the esophagus using differential normalized fluorescence (DNF) indices.

BACKGROUND AND OBJECTIVE: We report the use of new diagnostic parameters based on the differential normalized fluorescence (DNF) signals for malignant tumor diagnosis. STUDY DESIGN/MATERIALS AND METHODS: Over 200 measurements of endogenous fluorescence from normal and malignant esophageal tissues were performed during routine endoscopy in 48 patients. A pulsed nitrogen-pumped dye laser was used to provide in situ excitation at 410 nm. Direct collection of the fluorescence signal emitted by the tissue was achieved using an intensified photodiode array detector equipped with a fiberoptic probe. RESULTS: The fluorescence signals were normalized with respect to the total fluorescence signal area. The cancer diagnosis indices were defined by the difference between the normalized fluorescence signal of a tumor and the mean value of a reference set of normal tissues. The results of the DNF approach were compared with endoscopic examinations and histopathology interpretations of the biopsy samples. Excellent correlation in the classification of normal and malignant tumors for the samples was found. CONCLUSION: The data indicated that the DNF approach has a significant potential to provide a direct, real-time, and in-situ technique for cancer diagnosis of the esophagus without requiring biopsy of the tumors and time-consuming histopathology tests.

Adenocarcinoma↗
PubMed1995

Spectroscopic diagnosis of esophageal cancer: new classification model, improved measurement system.

Laser-induced fluorescence spectroscopy was used to measure fluorescence emission of normal and malignant tissue during endoscopy in patients with esophageal cancer and volunteers with normal esophagus. The spectroscopy system consisted of a nitrogen-pumped dye-laser tuned at 410 nm for excitation source, an optical multichannel analyzer for spectrum analysis, and a fiberoptic probe designed for both the delivery of excitation light and the collection of fluorescence emission from tissue. The fluorescence lineshape of each spectrum was determined and sampled at 15-nm intervals from 430 to 716 nm. A calibration set of spectra from normal and malignant spectra was selected. Using stepwise discriminate analysis, significant wavelengths that separated normal from malignant spectra were selected. The intensities at these wavelengths were used to formulate a classification model using linear discriminate analysis. The model was then used to classify additional tissue spectra from 26 malignant and 108 normal sites into either normal or malignant spectra. A sensitivity of 100% and specificity of 98% were obtained.

Algorithms↗
PubMed1981

Irreducible fracture-dislocations of the ankle associated with interposition of the tibialis posterior tendon: case report and review of the literature of a specific ankle fracture syndrome.

A severe closed pronation-eversion fracture-dislocation of the ankle that was irreducible by closed means was encountered. Exploration to accomplish open reduction revealed displacement of the tibialis posterior tendon through the diastasis between the distal tibia and fibula. The tibialis posterior tendon was found to pass posteriorly to an anteriorly between the distal tibia and fibula and laterally to medially across the anterior surfaces of the distal tibia and neck of the talus. Reduction was blocked by the tibialis posterior tendon in its abnormal course. After replacement of the tibialis posterior tendon in its anatomic position, reduction was accomplished. Internal fixation was then performed uneventfully. Two previous similar cases of irreducible ankle fractures due to displacement of the tibialis posterior tendon through the diastasis between the distal tibia and fibula have been reported in the literature. This uncommon syndrome is reported as a possible etiology to be considered when failure of reduction of an ankle fracture is encountered.

Adult↗