Estimation of anisotropy coefficient of swine pancreas,liver and muscle at 1064 nm based on goniometric technique

Optical properties of tissues are required for theoretical modeling of Laser Ablation in tumor therapy. The light scattering characteristic of tissues is described by the anisotropy coefficient, g. The relationship between the angular distribution of scattered light and g is given by the Henyey‐Greenstein (HG) phase function. This work describes the estimation of anisotropy coefficients of ex vivo swine pancreas, liver and muscle at 1064 nm. The intensities of scattered light at fixed angles were measured under repeatability conditions. Experimental data were fitted with a two‐term HG, estimating the anisotropy coefficients for the forward (e.g., 0.956 for pancreas, 0.964 for liver and 0.968 for muscle) and the backward (e.g., –0.481 for pancreas, –0.414 for liver and –0.372 for muscle) scattering.

Experimental set up employed to estimate the anisotropy coefficient of biological tissues. The image on the left depicts the holder used to house tissue, laser fiber and photodetector; on the left an example of scattered light beam is shown, as well as the effect due to Snell's law.     

Identification of a novel boronic acid as a potent,selective, and orally active hormone sensitive lipase inhibitor

Hormone sensitive lipase (HSL) is an attractive therapeutic target of dyslipidemia. We designed and synthesized several compounds as reversible HSL inhibitors with a focus on hydrophobic interactions, which was thought to be effective upon the HSL inhibitory activity. In these efforts, we identified boronated compound 12 showing a potent HSL inhibitory activity with an IC₅₀ value of 7 nM and a high selectivity against cholinesterases. Furthermore, compound 12 is the first boron containing HSL inhibitor that has shown an antilipolytic effect in rats after oral administration at 3 mg/kg.     

猪-C反应蛋白的分离纯化及其性质的研究

以猪血清为材料,通过磷酸乙醇胺—琼脂糖亲和层析,Sepharose 4B柱层析和Sephacryl—S300凝胶过滤,获得了猪C—反应蛋白的结晶。猪C—反应蛋白可与肺炎球菌壁C多糖发生特异的沉淀反应,这种结合是依赖钙离子的。EDTA和一些磷脂代谢产物如磷酸胆碱,磷酸乙醇胺等,能抑制猪C—反应蛋白与C多糖的结合。在SDS—聚丙烯酰胺凝胶电泳及梯度聚丙烯酰胺凝胶电泳中,猪C—反应蛋白表现出与人C—反应蛋白相同的行为,亚基是一条分子量为23.5kD的肽链,全分子的表观分子量为150kD。猪C—反应蛋白与兔抗人C—反应的蛋白的抗血清能发生免疫交叉反应。     

A New Screening Method of Viral-neuraminidase Inhibitors

A new and practical method for the screening of neuraminidase inhibitors (NI) by means of the viral hemagglutination (HA)-dehemagglutination(deHA) reactions was suggested. The best conditions for the HA and deHA reactions were investigated. Existence of strong inhibition activity on the viral deHA has been recognized in the culture filtrates of some strains of actinomycetes. All of these deHA inhibitors showed NI activity that is not specified to the strain of the test viruses. About 0.25 mg/ml of the preparation obtained from the culture filtrate of the strongest actinomycetes, No. 289, inhibited the liberation of neuraminic acid from bovine submaxillary mucin by 80 HA units/ml of influenza A Fukuoka/1/70 (H₃N₂) virus up to 80%.     

Effects of sorbitol addition on the action of free and immobilized hydrolytic enzymes in organic media

The effect of the addition of sorbitol on the activity and stability of enzymes was examined by monitoring transesterification reactions performed in organic media at various water activities (a(w) = 0.08 to 0.97). Lipases from Chromobacterium viscosum and Candida rugosa immobilized on celite, and chymotrypsin, free or immobilized on celite, were used. When the sorbitol-containing enzymes were employed, higher reaction rates and less hydrolysis were observed. Immobilization of chymotrypsin resulted in high activity and operational stability, while the nonimmobilized enzyme was stable only in the presence of sorbitol. The activity of all preparations diminished after washing them with pyridine to remove sorbitol. Furthermore, severe stability problems occurred in the preparations lacking sorbitol. Sorbitol treatment, even after removal of the sorbitol itself, improved the activity of nonimmobilized chymotrypsin relative to the washed control. On the other hand, washing to remove sorbitol had a negative effect on the activity of both coimmobilized lipase and coimmobilized chymotrypsin. Addition of a substrate analogue, N-acetyl-L-phenylalanine, to chymotrypsin yielded a preparation that exhibited higher activity than both the control and its sorbitol-containing counterpart. Differential scanning calorimetry measurements revealed that the chymotrypsin-sorbitol complex was stable against thermal denaturation, undergoing transition at a high temperature (89 degrees C). The transition temperatures of the substrate-containing chymotrypsin and of the control were identical (72 degrees C). (c) 1995 John Wiley & Sons, Inc.     

Optimization for producing cell-bound lipase from <Emphasis Type="Italic">Geotrichum</Emphasis> sp. and synthesis of methyl oleate in microaqueous solvent

An integrated optimization strategy involving a combination of different designs was employed to optimize producing conditions of cell-bound lipase (CBL) from Geotrichum sp. Firstly, it was obtained by a single factorial design that the most suitable carbon source was a mixture of olive oil and citric acid and the most suitable nitrogen source was a mixture of corn steep liquor and NH₄NO₃. Then, the Plackett–Burman design was used to evaluate the effects of 13 variables related to CBL production, and three statistically significant variables namely, temperature, olive oil concentration, and NH₄NO₃ concentration, were selected. Subsequently, the levels of the three variables for maximum CBL production were determined by response surface analysis as follows: 1.64% (v/v) olive oil, 1.49% (w/v) NH₄NO₃, and temperature 33.00°C. Such optimization resulted in a high yield of CBL at 23.15 U/ml, an enhanced 4.45-fold increase relative to the initial result (5.2 U/ml) in shake flasks. The dried CBL was used to synthesize methyl oleate in microaqueous hexane, resulting in 94% conversion after 24 h, and showed reusability with 70% residual activity and 69% conversion after eight cycles of batch operation, which indicating that CBL, as a novel and natural form of immobilized enzyme, can be effectively applied in repeated synthesis of methyl oleate in a microaqueous solvent.     

Isolation and characterization of Acinetobacter sp. ES-1 excreting a lipase with high enantioselectivity for (S)-ketoprofen ethyl ester

A new Acinetobacter sp. ES-1, grown on triolein, tryptone and Triton X-100, excreted a lipase that hydrolyzed 10m M (R,S)-ketoprofen ethyl ester into (S)-ketoprofen. The crude lipase had an activity of 10Uml^-1 and, at 30°C and pH7 over 48h, gave a conversion yield of 35% with an enantiomeric excess for the product 96%.     

Role of calpains in diabetes mellitus: A mini review

Type 2 diabetes mellitus (T2DM) is characterized by defects in haepatic glucose production, insulin action and insulin secretion, which can also lead to a variety of secondary disorders. The disease can lead to death without treatment and it has been predicted that T2DM will affect 215 million people world-wide by 2010. T2DM is a multifactorial condition whose precise genetic causes and biochemical defects have not been fully elucidated but at both levels, calpains appear to play a role. Positional cloning studies mapped T2DM susceptibility to CAPN10, the gene encoding the intracellular cysteine protease, calpain 10. Further studies have shown a number of non-coding polymorphisms in CAPN10 to be functionally associated with T2DM whilst the identification of coding polymorphisms, suggested that mutant calpain 10 proteins may also contribute to the disease. The presence of both calpain 10 and its mRNA have been demonstrated in tissues from several mammalian species whilst calpain 10 appears to be associated with pathways involved in glucose metabolism, insulin secretion and insulin action. It appears that other calpains may also participate in these pathways and here we present an overview of recent studies on calpains and their putative role in T2DM. (Mol Cell Biochem 261: 161–167, 2004)