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Colin Thomas

Publications and source records attributed to Colin Thomas.

3 recordsLinked to original sources
PubMed2006

Comparison of plant cell turgor pressure measurement by pressure probe and micromanipulation.

The conventional method of measuring plant cell turgor pressure is the pressure probe but applying this method to single cells in suspension culture is technically difficult and requires puncture of the cell wall. Conversely, compression testing by micromanipulation is particularly suited to studies on single cells, and can be used to characterise cell wall mechanical properties, but has not been used to measure turgor pressure. In order to demonstrate that the micromanipulation method can do this, pressure measurements by both methods were compared on single suspension-cultured tomato (Lycopersicon esculentum vf36) cells and generally were in good agreement. This validates further the micromanipulation method and demonstrates its capability to measure turgor pressure during water loss. It also suggests that it might eventually be used to estimate plant cell hydraulic conductivity.

Cells, Cultured↗
PubMed2006

Brief report: a red streak in the lateral recess of the oropharynx predicts acute sinusitis.

OBJECTIVE: To evaluate the oropharyngeal red streak sign for diagnosing acute sinusitis. DESIGN: Exploratory cohort study. SETTING: A Veterans Affairs medical center urgent care center. PARTICIPANTS: Sixty consecutive subjects presenting with nasal symptoms lasting 4 weeks or less. MEASUREMENTS AND MAIN RESULTS: Each subject underwent a structured history and physical examination, followed by a sinus computed tomography (CT) scan. Acute sinusitis was defined by an air-fluid level or opacification of 1 or more sinuses on CT imaging. Twenty-seven subjects were diagnosed with sinusitis. A localized red streak in the lateral recess of the oropharynx was associated with sinusitis, with a positive likelihood ratio (LR+) and 95% confidence interval (CI) of 2.11 (1.23, 3.63) and a negative likelihood ratio (LR-) and 95% CI of 0.44 (0.24, 0.83). Opacity on maxillary or frontal sinus transillumination was also associated with sinusitis (LR+ of 1.89; CI 1.03, 3.32 and LR- of 0.56; CI 0.32, 0.96). Symptom duration > 10 days was associated with acute sinusitis with an LR+ of 1.89 (1.06, 3.59). A history of facial pain (LR+ of 0.59; CI 0.39, 0.90 and LR- of 2.85; CI 1.27, 6.41) and the finding of sinus percussion tenderness (LR+ of 0.22; CI 0.05, 0.90 and LR- of 1.88; CI 1.17, 3.03) were inversely associated with sinusitis. CONCLUSIONS: The oropharyngeal red streak may be an accurate physical sign for diagnosing acute sinusitis. This sign should be included in future studies of clinical diagnostic criteria for acute sinusitis.

Adult↗