Clinical Utility of Insulin-Like Growth Factor 1 and 2; Determination by High Resolution Mass Spectrometry

Measurement of insulin-like growth factor-1 (IGF-I) has utility for the diagnosis and management of growth disorders, but inter-assay comparison of results has been complicated by a multitude of reference standards, antibodies, detection methods, and pre-analytical preparation strategies. We developed a quantitative LC-MS method for intact IGF-I, which has advantages in throughput and complexity when compared to mass spectrometric approaches that rely on stable isotope dilution analysis of tryptic peptides. Since the method makes use of full-scan data, the assay was easily extended to provide quantitative measurement of IGF-II using the same assay protocol. The validated LC-MS assay for IGF-I and IGF-II provides accurate results across the pediatric and adult reference range and is suitable for clinical use.     

Use of thermometers in general practice.

OBJECTIVE--To identify the attitudes of general practitioners towards the use of thermometers in general practice. DESIGN--Postal questionnaire survey. SETTING--All general practitioners in the catchment area of Frimley Park Hospital, Surrey. SUBJECTS--145 general practitioners. MAIN OUTCOME MEASURES--Answers to questions covering a variety of aspects concerning the use of thermometers in general practice. RESULTS--116 (80%) doctors replied. Seven doctors did not have any method of taking a patient''s temperature; up to 12 more doctors did not use their thermometers and 56 doctors used them infrequently, less than once a fortnight. Mercury glass thermometers were most commonly used (80 doctors; 69%), but only 8% of doctors used them correctly. Six doctors failed to clean their thermometers between patients. The study failed to identify the roles of axillary and rectal temperature readings. CONCLUSION--There is a wide variation in attitudes towards the use of thermometers in general practice.     

Disentangling the link between leaf photosynthesis and turgor in fruit growth

Despite the importance of understanding plant growth, the mechanisms underlying how plant and fruit growth declines during drought remain poorly understood. Specifically, it remains unresolved whether carbon or water factors are responsible for limiting growth as drought progresses. We examine questions regarding the relative importance of water and carbon to fruit growth depending on the water deficit level and the fruit growth stage by measuring fruit diameter, leaf photosynthesis, and a proxy of cell turgor in olive (Olea europaea). Flow cytometry was also applied to determine the fruit cell division stage. We found that photosynthesis and turgor were related to fruit growth; specifically, the relative importance of photosynthesis was higher during periods of more intense cell division, while turgor had higher relative importance in periods where cell division comes close to ceasing and fruit growth is dependent mainly on cell expansion. This pattern was found regardless of the water deficit level, although turgor and growth ceased at more similar values of leaf water potential than photosynthesis. Cell division occurred even when fruit growth seemed to stop under water deficit conditions, which likely helped fruits to grow disproportionately when trees were hydrated again, compensating for periods with low turgor. As a result, the final fruit size was not severely penalized. We conclude that carbon and water processes are able to explain fruit growth, with importance placed on the combination of cell division and expansion. However, the major limitation to growth is turgor, which adds evidence to the sink limitation hypothesis.