Zymobacter palmae Pyruvate Decarboxylase is Less Effective Than That of Zymomonas mobilis for Ethanol Production in Metabolically Engineered Synechocystis sp. PCC6803.

To produce bioethanol from model cyanobacteria such as Synechocystis, a two gene cassette consisting of genes encoding pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) are required to transform pyruvate first to acetaldehyde and then to ethanol. However the partition of pyruvate to ethanol comes at a cost, a reduction in biomass and pyruvate availability for other metabolic processes. Hence strategies to divert flux to ethanol as a biofuel in Synechocystis are of interest. PDC from Zymobacter palmae (ZpPDC) has been reported to have a lower Km then the Zymomonas mobilis PDC (ZmPDC), which has traditionally been used in metabolic engineering constructs. The Zppdc gene was combined with the native slr1192 alcohol dehydrogenase gene (adhA) in an attempt to increase ethanol production in the photoautotrophic cyanobacterium Synechocystis sp. PCC 6803 over constructs created with the traditional Zmpdc. Native (Zppdc) and codon optimized (ZpOpdc) versions of the ZpPDC were cloned into a construct where pdc expression was controlled via the psbA2 light inducible promoter from Synechocystis sp. PCC 6803. These constructs were transformed into wildtype Synechocystis sp. PCC 6803 for expression and ethanol production. Ethanol levels were then compared with identical constructs containing the Zmpdc. While strains with the Zppdc (UL071) and ZpOpdc (UL072) constructs did produce ethanol, levels were lower compared to a control strain (UL070) expressing the pdc from Zymomonas mobilis. All constructs demonstrated lower biomass productivity illustrating that the flux from pyruvate to ethanol has a major effect on biomass and ultimately overall biofuel productivity. Thus the utilization of a PDC with a lower Km from Zymobacter palmae unusually did not result in enhanced ethanol production in Synechocystis sp. PCC 6803.

Is satisfaction with surgeon a determining factor in patient reported outcomes in breast reconstruction?

BACKGROUND: Patient reported outcomes are increasingly being taken into account in planning health service provision. Few studies have examined how the process of care influences patients' perception of outcome. The aim of the current study was to quantify patient satisfaction with breast reconstruction and to examine the demographic, disease and process-of-care variables that contributed to satisfaction with breasts and overall outcome. METHODS: A cross-sectional study was designed and the BREAST-Q outcomes assessment instrument was used to evaluate patient-reported psychosocial, physical and sexual well-being, as well as satisfaction with breasts, overall outcome and process of care. To identify factors predictive of satisfaction with breasts and overall outcome, the relation between covariates and each of these scales was assessed using linear regression models. RESULTS: Sixty one patients, with a mean age of 50 years, completed the survey. Mean satisfaction with breasts was 59.6% and satisfaction with overall outcome was 73.2%. Satisfaction across health-related quality of life scales ranged from 44.6% for sexual well-being to 74.6% for physical well-being. The mean rating for psychosocial well-being was 67.9%. Satisfaction ratings for surgeon, medical staff and office staff were all over 90%. Satisfaction with plastic surgeon was predictive of satisfaction with outcome and satisfaction with breasts (P = 0.001 and 0.021 respectively). DISCUSSION: The surgeon-patient relationship significantly influences patient reported outcomes in breast reconstruction. Further service development must recognize the need for additional time and personnel to deliver high standard, patient-centered care.