マウスリンパ組織のレプチンレセプター発現細胞の検出

Leptin, the product of the ob gene expressed in adipocytes, is shown to influence energy intake and expenditure, proliferation of CD^ T cells, neovascularization and intracellular triglycerides homeostasis in non-adipocytes. Leptin acts on target cells through receptor (OB-R). There are at least five different types of OB-R in mouse due to alternative splicing from db gene transcripts.OB-Ra〜OB-Rd share identical extracellular and transmembrane domains and JAK binding consensus sequence at cytoplasmic domain. Only OB-Rb has an additional STAT binding motif and is essential for most of leptin' s physiological functions through JAK-STAT pathway. OB-Ra is also reported to transduct weakly leptin's signal through JAK-phospholyration pathway. On this paper we examined which kinds of cell express OB-Ra or OB-Rb in lymphoid and fat tissues of the mouse. Both types of OB-R were detected in thymus, spleen and gastrolienal fat tissue by RTPCR method, then the constitutive cells were separated from dissected tissues and cultured in GIT medium with 10% heat-inactivated FBS. Primary cultured lymphocytes isolated from thymus or spleen expressed both OB-Ra and OB-Rb. On the other hand, in adhesive cells dispersed with enzymatic digestion and primary cultured OB-Rb was not detected, though OB-Ra detectable.Similarly, primary cultured adhesive cells of gastrolienal fat tissue expressed only OB-Ra. It is therefore most parsimonious to conclude that only lymphocytes express OB-Rb and response effectively to leptin in thymus

Effect of Ozone and Calcium Lactate Treaments on Browning and Textured Properties of Fresh-Cut Lettuce

The effects of three treatments, 1 mg L−1 ozone at 18–20 °C, 15 g L−1 calcium lactate (CLac) at 50 °C and a combination thereof, were compared on fresh-cut lettuce over 10 days of refrigerated storage. Respiration rate, browning and texture were examined as main quality indicators. The use of ozone produced a significantly (P \u3c 0.05) higher oxygen decline than the use of CLac (from day 3 to day 10). At the end of storage, CLac (alone or combined with ozone) samples had higher oxygen content (∼9%) than ozone samples (∼6%). Enzymatic activity decreased significantly (P \u3c 0.05) in ozone samples. Polyphenol oxidase activity in fresh-cut lettuce treated with ozone (alone or combined with CLac) showed lower values on day 1 (−1) and at the end of storage (g−1) than CLac samples (4000–4800 units g−1). Ozone also reduced peroxidase activity to ∼300 units g−1 after treatment. Finally, pectin methylesterase activity was also reduced with ozone, showing a negative effect on textural properties. Data suggested that CLac maintained quality markers better than treatments with ozone and ozone/CLac combination over 10 days of storag

Splicing factor and exon profiling across human tissues

It has been shown that alternative splicing is especially prevalent in brain and testis when compared to other tissues. To test whether there is a specific propensity of these tissues to generate splicing variants, we used a single source of high-density microarray data to perform both splicing factor and exon expression profiling across 11 normal human tissues. Paired comparisons between tissues and an original exon-based statistical group analysis demonstrated after extensive RT-PCR validation that the cerebellum, testis, and spleen had the largest proportion of differentially expressed alternative exons. Variations at the exon level correlated with a larger number of splicing factors being expressed at a high level in the cerebellum, testis and spleen than in other tissues. However, this splicing factor expression profile was similar to a more global gene expression pattern as a larger number of genes had a high expression level in the cerebellum, testis and spleen. In addition to providing a unique resource on expression profiling of alternative splicing variants and splicing factors across human tissues, this study demonstrates that the higher prevalence of alternative splicing in a subset of tissues originates from the larger number of genes, including splicing factors, being expressed than in other tissues

Oxidative discolouration in whole-head and cut lettuce: biochemical and environmental influences on a complex phenotype and potential breeding strategies to improve shelf-life

Lettuce discolouration is a key post-harvest trait. The major enzyme controlling oxidative discolouration has long been considered to be polyphenol oxidase (PPO) however, levels of PPO and subsequent development of discolouration symptoms have not always correlated. The predominance of a latent state of the enzyme in plant tissues combined with substrate activation and contemporaneous suicide inactivation mechanisms are considered as potential explanations for this phenomenon. Leaf tissue physical properties have been associated with subsequent discolouration and these may be influenced by variation in nutrient availability, especially excess nitrogen and head maturity at harvest. Mild calcium and irrigation stress has also been associated with a reduction in subsequent discolouration, although excess irrigation has been linked to increased discolouration potentially through leaf physical properties. These environmental factors, including high temperature and UV light intensities, often have impacts on levels of phenolic compounds linking the environmental responses to the biochemistry of the PPO pathway. Breeding strategies targeting the PALand PPOpathway biochemistry and environmental response genes are discussed as a more cost-effective method of mitigating oxidative discolouration then either modified atmosphere packaging or post-harvest treatments, although current understanding of the biochemistry means that such programs are likely to be limited in nature and it is likely that they will need to be deployed alongside other methods for the foreseeable future

Singing voice synthesis combining excitation plus resonance and sinusoidal plus residual models

This paper presents an approach to the modeling of the singing voice with a particular emphasis on the naturalness of the resulting synthetic voice. The underlying analysis/synthesis technique is based on the Spectral Modeling Synthesis (SMS) and a newly developed Excitation plus Resonance (EpR) model. With this approach a complete singing voice synthesizer is developed that generates a vocal melody out of the score and the phonetic transcription of a song

Singing voice synthesis combining excitation plus resonance and sinusoidal plus residual models

This paper presents an approach to the modeling of the singing voice with a particular emphasis on the naturalness of the resulting synthetic voice. The underlying analysis/synthesis technique is based on the Spectral Modeling Synthesis (SMS) and a newly developed Excitation plus Resonance (EpR) model. With this approach a complete singing voice synthesizer is developed that generates a vocal melody out of the score and the phonetic transcription of a song