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Summary: Adipocyte size is a major modulator of endocrine functioning of tissue and methods allowing accurate determination of adipocyte size are important to study energy metabolism. The aim of this study was to relative shrinkage of adipocytes before and after weight loss by adipose tissue from the same subjects embedded in paraffin and plastic. healthy subjects (5 males and 13 females) aged 20-50 y with a BMI of 28- kg/m(2) followed a very low energy diet for 8 weeks. Adipose tissue taken prior to and after weight loss and were processed for paraffin and sections. Parameters of adipocyte size were determined with computer analysis. Mean adipocyte size was smaller in paraffin compared to embedded tissue both before (66 +/- 4 vs. 103 +/- 5 mum, P < 0.001) as weight loss (62 +/- 4 vs. 91 +/- 5 mum, P < 0.001). Relative shrinkage adipocytes in paraffin embedded tissue in proportion to plastic embedded was not significantly different before and after weight loss (73 and respectively). Shrinkage due to the type of embedding of the adipose be ignored when comparing before and after weight loss. Plastic adipose tissue provides more accurate and sensitive results.

Summary: Adipocyte size is a major modulator of endocrine functioning of tissue and methods allowing accurate determination of adipocyte size are important to study energy metabolism. The aim of this study was to relative shrinkage of adipocytes before and after weight loss by adipose tissue from the same subjects embedded in paraffin and plastic. healthy subjects (5 males and 13 females) aged 20-50 y with a BMI of 28- kg/m(2) followed a very low energy diet for 8 weeks. Adipose tissue taken prior to and after weight loss and were processed for paraffin and sections. Parameters of adipocyte size were determined with computer analysis. Mean adipocyte size was smaller in paraffin compared to embedded tissue both before (66 +/- 4 vs. 103 +/- 5 mum, P < 0.001) as weight loss (62 +/- 4 vs. 91 +/- 5 mum, P < 0.001). Relative shrinkage adipocytes in paraffin embedded tissue in proportion to plastic embedded was not significantly different before and after weight loss (73 and respectively). Shrinkage due to the type of embedding of the adipose be ignored when comparing before and after weight loss. Plastic adipose tissue provides more accurate and sensitive results.

Pseudomonas putida strain S12palB1 was constructed that produces p-hydroxybenzoate from renewable carbon sources via the central metabolite l-tyrosine. P. putida S12palB1 was based on the platform strain P. putida S12TPL3, which has an optimised carbon flux towards l-tyrosine. Phenylalanine ammonia lyase (Pal) was introduced for the conversion of l-tyrosine into p-coumarate, which is further converted into p-hydroxybenzoate by endogenous enzymes. p-Hydroxybenzoate hydroxylase (PobA) was inactivated to prevent the degradation of p-hydroxybenzoate. These modifications resulted in stable accumulation of p-hydroxybenzoate at a yield of 11% (C-mol C-mol-1) on glucose or on glycerol in shake flask cultures. In a glycerol-limited fed-batch fermentation, a final p-hydroxybenzoate concentration of 12.9 mM (1.8 g l-1) was obtained, at a yield of 8.5% (C-mol C-mol-1). A 2-fold increase of the specific p-hydroxybenzoate production rate (qp) was observed when l-tyrosine was supplied to a steady-state C-limited chemostat culture of P. putida S12palB1. This implied that l-tyrosine availability was the bottleneck for p-hydroxybenzoate production under these conditions. When p-coumarate was added instead, qp increased by a factor 4.7, indicating that Pal activity is the limiting factor when sufficient l-tyrosine is available. Thus, two major leads for further improvement of the p-hydroxybenzoate production by P. putida S12palB1 were identified. © 2007 Elsevier B.V. All rights reserved.