Malic and citric acids accumulate in cherry tomato (Lycopersicon esculentum Mill.) fruit during the period of rapid growth, from the end of cell division to the onset of ripening. The involvement of phospho enolpyruvate carboxylase (PEPCase, EC 4.1.1.31) in organic acid accumulation and tomato fruit development was investigated. Two PEPCases, named LYCes;Ppc1 and LYCes;Ppc2 and mapped to chromosomes 12 and 7, respectively, were shown to be differentially expressed during tomato fruit development. LYCes;Ppc1 mRNA was present in all fruit tissues and in all other plant organs examined. In contrast, LYCes;Ppc2 was strongly and specifically expressed in fruit from the end of cell division to ripening. No LYCes;Ppc2 expression was detected by northern blot in other plant tissues. In fruit, the increase in LYCes;Ppc2 mRNA was closely followed by an increase in fruit PEPCase protein and activity, and was coincident with the increased accumulation of malate and citrate during the initial period of rapid growth rate, from 8 to 20 days post anthesis. Localization of LYCes;Ppc2 mRNA in young tomato fruit by in situ hybridization revealed that LYCes;Ppc2 is preferentially expressed in large cells of the pericarp and in enlarging cells of the gel surrounding the seeds. Examination of the kinetic and regulatory properties of the PEPCases of growing and ripening fruit further showed that PEPCase in growing fruit is less sensitive to low pH and malate inhibition, indicating a high phosphorylation state and/or the presence of a PEPCase isoform with these characteristics. Taken together, these results indicate that in developing tomato fruit PEPCase is probably important in permitting the synthesis of organic acids to provide the turgor pressure necessary for cell expansion.
The impact of patient-physician communication and levels of understanding of treatment on patient knowledge and compliance has been studied in patients undergoing their first cycle of infertility treatment. This observational, real-life, longitudinal study involved 488 patients from 28 infertility centres in France. Data on communication quality, understanding of treatment instructions, patient knowledge and compliance to treatment protocol were collected through questionnaires administered before treatment initiation (V1) and at oocyte retrieval (V2). At V1, patients were very satisfied with their levels of understanding of the injection and monitoring schedules, the information given by the medical team, and the way of receiving instructions, with average ratings on a scale of 0-100% of N 75%. They rated their understanding of possible treatment side-effects as satisfactory (average score 71.1%). Gaps in patient knowledge about their treatment, revealed by discrepancies between physician and patient reports, were observed in 20.5% of patients (n = 79/386), and most commonly resulted from confusion about the units and dose of gonadotropin. Anxiety about performing self-injections and a lack of confidence in their ability to self-inject correctly were each observed in approximately one-third of patients. Patient self-assessment of compliance at V2 revealed that 27% of patients (n = 83/305) did not comply with or had doubts about the injection schedule or dose injected. Meanwhile physicians reported high levels of patient
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