The process of polar auxin transport, central to a plant's auxin relations, can be inhibited by a group of synthetic compounds that apparently act by binding to a plasma membrane protein known as the naphthylphthalamic acid (NPA) receptor. No endogenous ligand to the NPA receptor, capable of affecting polar auxin transport in plants, has yet been found. It is now shown that a group of flavonoids-including quercetin, apigenin, and kaempferol-can specifically compete with [(3)H]NPA for binding to its receptor and can perturb auxin transport in a variety of plant tissues and transport systems in a manner closely paralleling the action of synthetic transport inhibitors. Because the active flavonoids are widely distributed in the plant kingdom and exert their effects at micromolar concentrations approximating likely endogenous levels, they may act as natural auxin transport regulators in plants.

BackgroundSynthesis of patient-reported outcome (PRO) data is hindered by the range of available PRO measures (PROMs) composed of multiple scales and single items with differing terminology and content. The use of core outcome sets, an agreed minimum set of outcomes to be measured and reported in all trials of a specific condition, may improve this issue but methods to select core PRO domains from the many available PROMs are lacking. This study examines existing PROMs and describes methods to identify health domains to inform the development of a core outcome set, illustrated with an example.MethodsSystematic literature searches identified validated PROMs from studies evaluating radical treatment for oesophageal cancer. PROM scale/single item names were recorded verbatim and the frequency of similar names/scales documented. PROM contents (scale components/single items) were examined for conceptual meaning by an expert clinician and methodologist and categorised into health domains. A patient advocate independently checked this categorisation.ResultsSearches identified 21 generic and disease-specific PROMs containing 116 scales and 32 single items with 94 different verbatim names. Identical names for scales were repeatedly used (for example, ‘physical function’ in six different measures) and others were similar (overlapping face validity) although component items were not always comparable. Based on methodological, clinical and patient expertise, 606 individual items were categorised into 32 health domains.ConclusionThis study outlines a methodology for identifying candidate PRO domains from existing PROMs to inform a core outcome set to use in clinical trials.

Background The main objectives of this study were to identify the number of randomized controlled trials (RCTs) that have included a patient-reported outcome (PRO) endpoint across a wide range of cancer specialties and to evaluate completeness of PRO reporting according to the CONSORT PRO extension. Methods RCTs with a PRO endpoint, conducted across several cancer specialties and published between 2004 and 2013 were considered. Studies were evaluated based on previously defined criteria, including the CONSORT PRO extension and the Cochrane Collaboration's tool for assessing RCT Risk of Bias. Analyses were also conducted by type of PRO endpoint (primary versus secondary) and by cancer disease site. Results A total of 56,696 potentially eligible records were scrutinized and 557 RCTs with a PRO evaluation, enrolling overall 254,677 patients, were identified. PROs were most frequently used in RCTs of breast (N=123), lung (N=85) and colorectal (N=66) cancer. Overall, PROs were secondary endpoint in 421 (76%) RCTs. Four out of six CONSORT PRO items evaluated were documented in less than 50% of the RCTs. Level of reporting was higher in RCTs with PRO as a primary endpoint. Presence of a supplementary report was the only statistically significant factor associated with greater completeness of reporting for both RCTs with PRO as primary (β=0.19; P=0.001) or secondary endpoint (β=0.30; P<0.001). Conclusion Implementation of the CONSORT PRO extension is equally important across all cancer specialties. Its use can also contribute in revealing the robust PRO design of some studies, which might be obscured by poor outcome reporting.

By means of an indirect immunofluorescence technique with the use of monoclonal antibodies, the location of the presumptive auxin transport carrier of pea stem tissue was identified in the plasma membranes at the basal ends of parenchyma cells sheathing the vascular bundles. The results represent what is believed to be the first direct evidence for the hypothesized basal efflux carrier conferring polarity to auxin transport in plant stems.

This study has established a core information set for surgery for oesophageal cancer.

The findings demonstrate what information physicians should have available and informs interventions to support patients in meeting their information needs.

A pH microelectrode has been used to investigate the auxin effect on free space pH and its correbtion with auxin-stimulated elongation in segments of pea (Pisum sativum) stem According to the currently popular acid secretion hypothesis of auxin action (2, 7), auxins stimulate growth by causing acidification of the cell walls, which at low pH undergo an increase in extensibility that leads to rapid cell enlargement. Several lines of evidence are consistent with this hypothesis (7,9,19,24), but published measurements of auxin-induced release of acid from tissue into an external bathing medium (3,10,11,18) have not shown that auxin stimulates H+ secretion quickly enough to account for the rapid response (17) of elongation to auxin. If the acid secretion theory is correct it must be demonstrable that following exposure to an auxin the pH in the cell wall space falls to an elongation-stimulating value by the time that observable elongation in response to auxin actually commences, i.e. within the latent period for auxin action on elongation. A pH microelectrode that permits this type of measurement (13) Arbor, Mich.) of exposed tip length of 5 Aim and tip diameter of 2 ,um. The reference electrode was a segment of glass tubing (80 x 1 mm) the end of which was drawn into a capillary with a tip diameter of a few ,um. This tube was filled with 3 M KCI, in which was immersed an AgCI-coated silver wire that connected to the reference terminal of the pH meter. The electrode was read using the mv mode of operation of the meter and was calibrated against phosphate-citrate buffers (50 mm in K-phosphate and Na-citrate) of pH 4 and 6 before and after each experiment.The relation between pH of a buffer solution and mv reading by the pH microelectrodes was checked for several microelectrodes with a series of solutions varying in pH from 4 to 7. Because this relation was always found to be linear over the pH range, mv readings from experiments were converted to pH values by linear interpolation using the mv values measured for the calibration buffers of pH 4 and 6.The sensitivity of a pH microelectrode varied, for different experiments, from 50 to 58 mv/pH unit, but it was always constant through a given experiment. Between the beginning and the end of a typical experiment, however, the absolute mv values recorded by the microelectrode for the two calibration buffers would often change by a few mv. This drift in value was always of the same magnitude and in the same direction for both calibration buffers. Thus, the sensitivity of the microelectrode did not drift. Although calibration of the microelectrode against buffers of known pH before and after each experiment allowed us to monitor microelectrode drift, we used only the results of the postexperiment calibration for conversion of microelectrode mv readings to pH values.

Patients will experience a clinically relevant and long-lasting deterioration in HRQL after esophageal cancer surgery. However, for many HRQL outcomes, more and better quality evidence is needed.