23 research outputs found

    Comparative transcriptomics and proteomics of p-hydroxybenzoate producing Pseudomonas putida S12: novel responses and implications for strain improvement

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    A transcriptomics and proteomics approach was employed to study the expression changes associated with p-hydroxybenzoate production by the engineered Pseudomonas putida strain S12palB1. To establish p-hydroxybenzoate production, phenylalanine-tyrosine ammonia lyase (pal/tal) was introduced to connect the tyrosine biosynthetic and p-coumarate degradation pathways. In agreement with the efficient p-hydroxybenzoate production, the tyrosine biosynthetic and p-coumarate catabolic pathways were upregulated. Also many transporters were differentially expressed, one of which—a previously uncharacterized multidrug efflux transporter with locus tags PP1271-PP1273—was found to be associated with p-hydroxybenzoate export. In addition to tyrosine biosynthesis, also tyrosine degradative pathways were upregulated. Eliminating the most prominent of these resulted in a 22% p-hydroxybenzoate yield improvement. Remarkably, the upregulation of genes contributing to p-hydroxybenzoate formation was much higher in glucose than in glycerol-cultured cells

    Pathological and Biological Differences Between Screen-Detected and Interval Ductal Carcinoma in situ of the Breast

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    Background: The incidence of ductal carcinoma in situ (DCIS) has risen dramatically with the introduction of screening mammography. The aim was to evaluate differences in pathological and biological characteristics between patients with screen-detected and interval DCIS. Methods: From January 1992 to December 2001, 128 consecutive patients had been treated for pure DCIS at our institute. From these, 102 had been attending the Dutch breast cancer screening program. Sufficient paraffin-embedded tissue was available in 74 out of the 102 cases to evaluate biological marker expression (Her2/neu, ER, PR, p53 and cyclin D1) on tissue microarrays (TMA group). Differences in clinicopathological characteristics and marker expression between screen-detected and interval patients were evaluated. Screen-detected DCIS was classified as DCIS detected by screening mammography, when the two-year earlier examination failed to reveal an abnormality. Interval patients were classified as patients with DCIS detected within the two-year interval between two subsequent screening rounds. Results: Screen-detected DCIS was related with linear branching and coarse granular microcalcifications on mammography (p < .001) and with high-grade DCIS according to the Van Nuys classification (p = .025). In univariate analysis, screen-detected DCIS was related with Her2/neu overexpression (odds ratio [OR] = 6.5; 95%CI 1.3-31.0; p = .020), and interval DCIS was associated with low-grade (Van Nuys, OR = 7.3; 95% CI 1.6-33.3; p = .010) and PR positivity (OR = 0.3; 95%CI 0.1-1.0; p = .042). The multivariate analysis displayed an independent relation of Her2/neu overexpression with screen-detected DCIS (OR = 12.8; 95%CI 1.6-104.0; p = .018). Conclusions: These findings suggest that screen-detected DCIS is biologically more aggressive than interval DCIS and should not be regarded as overdiagnosis

    Stress modulation as a means to improve yeasts for lignocellulose bioconversion

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    The second-generation (2G) fermentation environment for lignocellulose conversion presents unique challenges to the fermentative organism that do not necessarily exist in other industrial fermentations. While extreme osmotic, heat, and nutrient starvation stresses are observed in sugar- and starch-based fermentation environments, additional pre-treatment-derived inhibitor stress, potentially exacerbated by stresses such as pH and product tolerance, exist in the 2G environment. Furthermore, in a consolidated bioprocessing (CBP) context, the organism is also challenged to secrete enzymes that may themselves lead to unfolded protein response and other stresses. This review will discuss responses of the yeast Saccharomyces cerevisiae to 2G-specific stresses and stress modulation strategies that can be followed to improve yeasts for this application. We also explore published –omics data and discuss relevant rational engineering, reverse engineering, and adaptation strategies, with the view of identifying genes or alleles that will make positive contributions to the overall robustness of 2G industrial strains

    A new pathological system for grading DCIS with improved prediction of local recurrence: results from the UKCCCR/ANZ DCIS Trial

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    Background: There is no consensus agreement regarding optimal management of locally excised ductal carcinoma in situ (DCIS) or features of greatest assistance in predicting disease behaviour. Cases in the UKCCCR/ANZ DCIS trial have been histologically reviewed to determine the features of prognostic importance. Method: A total of 72% of 1694 cases entered into the UKCCCR/ANZ DCIS trial had full pathological review. A large number of histological features were assessed, blinded to outcome and compared regarding ability to predict ipsilateral recurrence, as either DCIS or progression to invasive carcinoma. Results: Pathological features associated with ipsilateral recurrence in univariate analysis included high cytonuclear grade, larger lesion size, growth pattern, presence of necrosis or chronic inflammation, incompleteness (or uncertainty of completeness) of excision and smaller margin width. Receipt of post-operative radiotherapy was also a strong prognostic factor. We report a novel sub-division of the large group of high-grade lesions, which enables identification of a very poor prognosis subgroup; namely, DCIS that is of high cytonuclear grade, predominantly (>50%) solid architecture, bearing extensive comedo-type necrosis (>50% of ducts). In addition, we found little difference in ipsilateral recurrence rates between low- and intermediate-grade groups. Hazard ratios for low, intermediate, high and the new, very high, grade were 0.42, 0.33, 0.62 and 1.00, respectively, for ipsilateral in situ or invasive recurrence. Conclusion: We present a novel pathological classification for DCIS with substantially better prognostic discrimination for ipsilateral recurrence than the classical categorisation based on cytonuclear grade alone
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