Detection of microsatellite instability in cancers by arbitrarily primed-PCR fingerprinting using a fluorescently labeled primer (FAP-PCR)

The microsatellite mutator phenotype (MMP), detected as a change in the number of repeating units in hundreds of thousands of microsatellite sequences in the tumor cell genome, underlies the carcinogenesis of a variety of tumors including sporadic and hereditary nonpolyposis colon cancers. This enhanced microsatellite instability was discovered using arbitrarily primed polymerase chain reaction (AP-PCR) fingerprinting of DNA from colon cancers. In this study, we found an arbitrary primer that can amplify multiple DNA fragments containing repeated sequences, including the poly A tracts found in the Alu repeats of the human genome. The combined use of primer labeling with fluorescence and an automated DNA sequencing analysis of AP-PCR products (FAP-PCR) detected alterations in fingerprint bands in all DNA samples previously determined to belong to the MMP. Fluorescent AP-PCR fingerprinting using this single arbitrary primer provides a convenient and efficient method for detecting tumor specific fingerprint alterations that are usually undetectable by conventional fingerprinting.     

Transient thermal stresses in an orthotropic finite rectangular plate due to arbitrary surface heat-generations

The transient thermal stresses in an orthotropic finite rectangular plate due to arbitrary surface heat-generations on two edges are studied by means of the Airy stress function.The purposes of this paper are to present a method of determining the transient thermal stresses in an orthotropic rectangular plate with four edges of distinct thermal boundary condition of the third kind which exactly satisfy the traction-free conditions of shear stress over all boundaries including four corners of the plate, and to consider the effects of the anisotropies of material properties and the convective heat transfer on the upper and lower surfaces on the thermal stress distribution.     

Characteristics of fats in Japanese diets and current recommendations

Although there is no firm evidence to support the “ideal” or even “appropriate” healthy level of dietary fat, the habitual fat consumption pattern in Japan seems to be a criterion for the recommended allowance both in the quantitative and qualitative points of view as judged from the life expectancy and the incidence of degenerative diseases. The new recommended dietary allowance of Japan, fifth revision effective for five years starting in 1995, adopted dietary fat levels of 20–25 energy percent, the ratio of saturated, monounsaturated, and polyunsaturated fatty acids at 1∶1.5∶1 and the ratio of n-6/n-3 at 4. The recommended fat level is similar to that previously consumed in Japan, and is even lower than that in diets used to treat hyperlipidemia in Western countries, current recommendations in those countries being 30 energy percent fat. Convincing data for the beneficial effects of n-3 polyunsaturated fatty acids on human health, in particular for healthy people, have been presented in only a few reports. However, the recommended n-6/n-3 ratio of 4 seems reasonable compared with the ratio of around 10 in other developed countries. In this context, it is more important to fully understand the nutritional and physiological roles of fat in healthy people rather than in those with chronic disease. At present, the low-fat dietary pattern in Japan appears to be a healthy way of eating.     

Cloning, expression analysis, and chromosomal localization of BH-protocadherin (PCDH7), a novel member of the cadherin superfamily

A method is described that allows simultaneous measurement of two spectrally distinguishable green fluorescent protein (GFP) mutants with a confocal microscope. In contrast to previously described methods, neither UV excitation nor repetition of scans is required. Therefore the method is well-suited to the long-time observation of living cells in three-dimensional microscopy and time series recording, as demonstrated with GFP-expressing Dictyostelium discoideum cells.     

Characterization of Distribution of Trap States in Silicon-on-Insulator Layers by Front-Gate Characteristics in n-Channel SOI MOSFETs

We characterized the distribution of trap states in silicon-on-insulator (SOI) layers in epitaxial layer transfer (ELTRAN) wafers and in low-dose separation by implanted oxygen (SIMOX) wafers. We measured the front- and back-gate characteristics of MOSFETs with SOI layers of different thicknesses. We used the current-Terman method to estimate the trap states at the gate oxide (GOX)/SOI interface and at the SOI/buried oxide (BOX) interface separately. As a result, we concluded that the high-density trap states in the SOI layers in SIMOX wafers cause a gate-voltage shift, which is attributed to the charged trap states only in the inversion layer. We also found that the trap states are distributed within about 30 nm from the SOI/BOX interface in the SOI layer in SIMOX wafers, which indicates that the distribution of trap states originates from the oxygen implantation that is peculiar to the SIMOX process.     

Stable repeated-batch production of recombinant dye-decolorizing peroxidase (rDyP) from Aspergillus oryzae

Recombinant Aspergillus oryzae expressing a dye-decolorizing peroxidase gene (dyp) was cultivated for repeated-batch production of recombinant dye-decolorizing peroxidase (rDyP) using maltose as a carbon source. High-level rDyP activity in limitation of carbon and nitrogen sources was maintained stably for 26 cycles of repeated 1-d batches of A. oryzae pellets without any additional pH control. Cultures maintained at 4 degrees C for 20 d resumed rDyP production following a single day of incubation. One liter filtrated crude rDyP containing 4600 U rDyP decolorized 5.07 g RBBR at the apparent decolorization rate of 17.7 mg l(-1) min(-1).     

SiO2 nanoparticles surface modified with polyethyleneimine-oleic acid complex as stabilizers of Ni fine particles in dense nonaqueous suspensions

SiO₂ nanoparticles (NPs) surface modified with polyethyleneimine-oleic acid complex (PEI-OA) has successfully prepared in a simple manner as a stabilizer of metal (Ni) fine particles (FPs) as well as a component of Ni/SiO₂ composite particles. Starting from SiO₂ NPs which were collected through centrifugation of commercial SiO₂ colloids, it was found that PEI-OA can effectively adsorbed on collected SiO₂ NPs surface during their redispersion process in toluene with the assistance of ultrasonication. The aggregated particle size (Z-average size) in toluene could be successfully reduced to c.a. 100 nm under saturated adsorption of PEI-OA. It was also found that PEI-OA-modified SiO₂ NPs can effectively attach to the Ni FPs by a simple mixing process in toluene. The FE-SEM observation confirmed the adsorption of the PEI-OA-modified SiO₂ NPs on the Ni FPs without forming severe NP aggregates. Owing to the attachment of the PEI-OA-modified SiO₂ NPs with surfaces that are compatible to toluene and α-terpineol, the suspension stability of the Ni/SiO₂ composite particles in these solvents drastically improved. The result was confirmed by the effective reduction of the sedimentation velocity of diluted suspensions as well as by the reduction of the viscosity of dense suspensions.     

Dietary conjugated linolenic acid in relation to CLA differently modifies body fat mass and serum and liver lipid levels in rats

The present study compared the effect of dietary conjugated linolenic acid (CLNA) on body fat and serum and liver lipid levels with that of CLA in rats. FFA rich in linoleic acid, α-linolenic acid, CLA, or CLNA were used as experimental fats. Male Sprague-Dawley rats (4 wk old) were fed purified diets containing 1% of one of these experimental fats. After 4 wk of feeding, adipose tissue weights, serum and liver lipid concentrations, serum tumor necrosis factor (TNF)-α and leptin levels, and hepatic β-oxidation activities were measured. Compared with linoleic acid, CLA and, more potently, CLNA were found to reduce perirenal adipose tissue weight. The same trend was observed in the weight of epididymal adipose tissue. CLNA, but not CLA, was found to significantly increase serum and liver IG concentrations. Serum FFA concentration was also increased in the CLNA group more than in the other groups. The activity of β-oxidation in liver mitochondria and peroxisomes was significantly higher in the CLNA group than in the other groups. Thus, the amount of liver TG exceeded the ability of hepatic β-oxidation. Significant positive correlation was found between the adipose tissue weights and serum leptin levels in all animals (vs. perirenal: r=0.557, P<0.001; vs. epididymal: r=0.405, P<0.05). A less significant correlation was found between adipose tissue weights and serum TNF-α level (vs. perirenal: r=0.069, P<0.1; vs. epididymal: r=0.382, P<0.05). Although the mechanism for the specific effect of CLNA is not clear at present, these findings indicate that in rats CLNA modulated the body fat and TG metabolism differently from CLA.     

Lymphatic absorption of oxidized cholesterol in rats

The absorption of cholesterol and of cholesterol oxidation products (oxidized cholesterols) was compared in lymph-cannulated rats. We found that the lymphatic absorption of an intragastrically administered, emulsified lipid meal containing 25 mg of cholesterol or 25 mg of oxidized cholesterols, within 24 h, was approximately 67 and 30%, respectively. The absorption rate of individual oxidized cholesterols differed considerably and was approximately 30% for 7α-hydroxycholesterol, 42% for 7β-hydroxycholesterol, 32% for 5β-epoxycholesterol, 28% for 5α-epoxycholesterol, 15% for cholestanetriol and 12% for 7-ketocholesterol. Moreover, cholesterol oxidation products delayed the absorption of oleic acid as triolein. Approximately 35 and 48% of cholesterol was recovered in chylomicrons (CM) and very low density lipoprotein (VLDL), respectively. In contrast, 54 and 40% of the oxidized cholesterols was recovered in CM and VLDL, respectively, although there was a significant difference in the distribution of individual oxidized cholesterols. The results of the present study indicate that oxidized cholesterols are absorbed to a lesser extent than is cholesterol, that they disturb fat absorption and that they distribute differently between lymphatic lipoproteins.