Phytosiderophore pathway response in barley exposed to iron, zinc or copper starvation.

Efficient micronutrient acquisition is a critical factor in selecting micronutrient dense crops for human consumption. Enhanced exudation and re-uptake of metal chelators, so-called phytosiderophores, by roots of graminaceous plants has been implicated in efficient micronutrient acquisition. We compared PS biosynthesis and exudation as a response mechanism to either Fe, Zn or Cu starvation. Two barley (Hordeum vulgare L.) lines with contrasting micronutrient grain yields were grown hydroponically and PS exudation (LC-MS) and root gene expression (RNAseq) were determined after either Fe, Zn, or Cu starvation. The response strength of the PS pathway was micronutrient dependent and decreased in the order Fe > Zn > Cu deficiency. We observed a stronger expression of PS pathway genes and greater PS exudation in the barley line with large micronutrient grain yield suggesting that a highly expressed PS pathway might be an important trait involved in high micronutrient accumulation. In addition to several metal specific transporters, we also found that the expression of IRO2 and bHLH156 transcription factors was not only induced under Fe but also under Zn and Cu deficiency. Our study delivers important insights into the role of the PS pathway in the acquisition of different micronutrients.

Stability assessment of serum tumour markers: Calcitonin, chromogranin A, thyroglobulin and anti-thyroglobulin antibodies.

BACKGROUND: There is limited published data on the stability of calcitonin, chromogranin A, thyroglobulin and anti-thyroglobulin antibodies in serum. The aim of this study was to determine stability at three temperature conditions over 7 days, reflecting current laboratory practices. METHODS: Surplus serum was stored at room temperature, refrigerated and in the freezer; for 1, 3, 5 and 7 days. Samples were analysed in batch and analyte concentrations compared to that of a baseline sample. Measurement Uncertainty of the assay was used to determine the Maximal Permissible Difference and thus the stability of the analyte. RESULTS: Calcitonin was found to be stable for at least 7 days in the freezer but only 24 h refrigerated. Chromogranin A was stable for 3 days when refrigerated and only 24 h at room temperature. Thyroglobulin and anti-thyroglobulin antibodies were stable under all conditions for 7 days. CONCLUSION: This study has enabled the laboratory to increase the add-on time limit of Chromogranin A to 3 days, and up to 60 min for calcitonin and inform optimal storage and transportation conditions for referring specimens.

Spuriously raised serum creatinine associated with an excipient present in an intravenous dexamethasone formulation.

Although the active pharmaceutical ingredient remains constant, the excipients used will vary according to the manufacturer. This case report is of spuriously raised serum creatinine due to an excipient in one particular intravenous dexamethasone formulation. A patient had three serum creatinine measurements of 102, 369 and 91 µmol/L over a four-hour period. The second result was believed to be spurious and appropriate investigations were instigated. The patient had received dexamethasone intravenously between the first and second blood samples. This was administered as a bolus via a cannula in the dorsum of the hand, and the blood sample was taken by venepuncture of the antecubital fossa of the same arm approximately five minutes later. The dexamethasone used (Hospira UK Ltd) contained creatinine at a concentration of 70,720 µmol/L, with a total of 170 µmol of creatinine given to the patient. Assuming a volume of distribution of 40 L in a 70-kg man, an increase in serum creatinine of 4-5 µmol/L would be expected once equilibrated. It is thought that the serum creatinine result observed was a consequence of the creatinine excipient in the dexamethasone not having completely distributed throughout the body and still being at relatively high concentrations within the limb into which it had been administered. Intravenous dexamethasone can lead to spurious creatinine results, not due to analytical interference but rather the analytically correct measurement of creatinine added as an excipient. This case clearly demonstrates the impact preanalytical factors can have on the accuracy of results.

An unusual case of floor of mouth swelling: case report, differential diagnosis and a review of the literature.

UNLABELLED: The oral cavity is an uncommon site for a true lipoma. A distinct histological variant is the spindle cell lipoma. This is a rare oral lesion. A case of an intra-oral spindle cell lipoma in a 55-year-old female is reported, a differential diagnosis is presented and the histopathology is discussed. CLINICAL RELEVANCE: An oral swelling is a common presenting complaint and requires further investigation.

Isolation of high molecular weight DNA suitable for BAC library construction from woody perennial soft-fruit species.

We have developed a novel nuclei extraction method that allows for the extraction of high molecular weight DNA from leaves of woody perennial soft-fruit species that contain high levels of carbohydrates and polyphenolics. The method utilizes a modified buffer system including 4% (w/v) polyvinylpyrrolidone (PVP)-10 and a combination of nylon filters and Percoll gradients to purify nuclei extracts prior to embedding in agarose plugs. The effectiveness of the method was demonstrated on leaves of red raspberry (Rubus idaeus) and blackcurrant (Ribes nigrum), two soft-fruit species that have shown to be recalcitrant to standard genomic DNA extraction methods. Extracted DNA was readily digested by restriction enzymes and, as shown for raspberry, suitable for bacterial artificial chromosome (BAC) library construction.