The expression levels of mRNAs for MDR1 (P-glycoprotein), multidrug resistance-associated proteins (MRP1, MRP2), and cytochrome P450 3A (CYP3A) in Caco-2 cells were quantitatively compared with those ...in human duodenal enterocytes, normal colorectal tissues, and colorectal adenocarcinomas. Caco-2 cells (passages 36-88) were kindly supplied by several laboratories in Japan. Human duodenal enterocytes were obtained from five healthy male volunteers. Normal colorectal tissues and colorectal adenocarcinomas were simultaneously obtained from seven patients with primary colorectal adenocarcinoma. MDR1, MRP1, MRP2, and CYP3A mRNA levels were determined by real-time quantitative polymerase chain reactions (PCR). Relative concentrations of mRNAs for target proteins (MDR1, MRP1, MRP2, and CYP3A) and glyceraldehyde-3-phosphate dehydrogenase in Caco-2 cells were 1.00 +/- 0.15, 1.02 +/- 0.06, 0.94 +/- 0.10, and 0.68 +/-0.60, respectively, and those in human enterocytes were about 12-, 3-, 7-, and 8000-fold higher than in the Caco-2 cells, respectively. In contrast, MDR1, MRP1, and CYP3A mRNA levels in Caco-2 cells were comparable to those in normal colorectal tissue and colorectal adenocarcinoma.
Corrosion wear fracture of new β type biomedical titanium alloys Niinomi, Mitsuo; Kuroda, Daisuke; Fukunaga, Kei-ichi ...
Materials science & engineering. A, Structural materials : properties, microstructure and processing,
05/1999, Letnik:
263, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
Metallic materials such as stainless steel, Co–Cr alloy, pure titanium and titanium alloys have been used for surgical implant materials. The α+β type titanium alloy such as Ti-6Al-4V ELI has been ...most widely used as an implant material for artificial hip joint and dental implant because of its high strength and excellent corrosion resistance. Toxicity of alloying elements in conventional biomedical titanium alloys like Al and V, and the high modulus of elasticity of these alloy as compared to that of bone have been, however, pointed out
1,2. New β type titanium alloys composed of non-toxic elements like Nb, Ta, Zr, Mo and Sn with lower moduli of elasticity, greater strength and greater corrosion resistance were, therefore, designed in this study. The friction wear properties of titanium alloys are, however, low as compared to those of other conventional metallic implant materials such as stainless steels and Co–Cr alloy. Tensile tests and friction wear tests in Ringer’s solution were conducted in order to investigate the mechanical properties of designed alloys. The friction wear characteristics of designed alloys and typical conventional biomedical titanium alloys were evaluated using a pin-on-disk type friction wear testing system and measuring the weight loss and width of groove of the specimen.
The phase boundary between spinel (gamma phase) and MgSiO3 perovskite + MgO periclase in Mg2SiO4 was determined by in situ x-ray measurements by a combination of the synchrotron radiation source ...(SPring-8) and a large multianvil high-pressure apparatus. The boundary was determined at temperatures between 1400 degrees to 1800 degreesC, demonstrating that the postspinel phase boundary has a negative Clapeyron slope as estimated by quench experiments and thermodynamic analyses. The boundary was located at 21.1 (+/-0.2) gigapascals, at 1600 degreesC, which is approximately 2 gigapascals lower than earlier estimates based on other high-pressure studies.
A train of low-frequency afferent stimuli (LFS, 1 Hz, 1000 pulses), given 60 min prior to a tetanus (100 Hz, 100 pulses), suppresses the induction of long-term potentiation (LTP) in which a ...short-term potentiation decreases gradually back to the pre-tetanic level within 40–50 min (LTP suppression). We investigated the effects of adenosine A1 or A2 receptor antagonists (8-cyclopentyltheophylline (8-CPT) and CP-66713, respectively) on LTP suppression in CA1 neurons of guinea pig hippocampal slices. When the LFS was delivered in the presence of 8-CPT (1 μM), LTP suppression was not significantly affected. However, when LFS was delivered in the presence of CP-66713 (10 μM), LTP suppression was inhibited, leading to successful LTP induction. These results indicate that endogenous adenosine, acting via A2 receptors, is involved in the mechanism of LTP suppression.
This paper describes a pyrolysis-trimethylsilylation procedure that is a new pyrolysis-derivatization thermochemolysis procedure of lignin.
N,
O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) was used ...as a trimethylsilylating reagent. A bulk dehydrogenative polymer of coniferyl alcohol (G-DHP) and a Japanese cedar (
Cryptomeria japonica D. Don) wood were pyrolyzed in the presence of BSTFA at 500°C for 4 s. The resultant volatile products were analyzed by gas chromatography/mass spectrometry (GC/MS). The G-DHP and the wood produced large abundances of trimethylsilyl (TMS) derivatized coniferyl alcohol (CA-(TMS)
2), in which both the phenolic and alcoholic hydroxyl groups are derivatized with TMS. CA-(TMS)
2 accounted for about 68% of the TMS derivatized products in the G-DHP pyrolysis, and about 24% of those in the wood pyrolysis. The results indicated that pyrolysis in the presence of trimethylsilylating reagents such as BSTFA is a potentially useful technique for drawing information on the pyrolytic precursors of cinnamyl alcohols (such as cinnamyl alcohol-end groups) from lignin. Pyrolysis-trimethylsilylation occurs in a one-step process and provides the TMS derivatives that are immediately available for the subsequent GC(/MS) analysis. This method is applicable to all lignocellulosic materials.
Interleukin-6 (IL-6) is a multifunctional cytokine secreted by various cells, and is involved in the acute phase response and the immune response through T and B cell activation. To further define ...the role of IL-6 in intestinal inflammation, we studied the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of the IL-6 gene. Acute colitis was induced in female IL-6-/- and IL-6+/+ mice by giving 4.5% DSS orally in drinking water for 8 days. The colonic mucosal injury and inflammation was evaluated based on survival rate, body-weight changes, total colon length and histological findings. Colonic mRNA expression for tumor necrosis factor (TNF)-alpha, IL-6, IL-10 and inducible nitric oxide synthase (iNOS) was measured by RT-PCR. Colonic IL-6 mRNA levels of wild-type mice continued to increase throughout the study period. At each assessment, colonic injury was significantly attenuated in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. Histological study also showed a reduced infiltration of inflammatory cells, especially neutrophils, and mucosal cell disruption in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. In the colons of DSS-treated IL-6-/- mice, the expression of both TNF-alpha mRNA and iNOS mRNA was reduced on day 5. In contrast, IL-10 mRNA expression was enhanced compared with DSS-treated IL-6+/+ mice. In conclusion, DSS-induced inflammation appears to be significantly inhibited in IL-6-/- mice compared to wild-type mice. These data suggest that persistent and marked blockade of IL-6 bioactivity provides some beneficial effects on intestinal inflammation.
In the rabbit mesenteric arterial smooth muscle skinned by saponin, Ca2+ induced contraction in a concentration-dependent manner. Guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), a non-hydrolyzable ...GTP analogue, lowered the Ca2+ concentrations required for this contraction and increased the Ca2+ sensitivity of the skinned smooth muscle contraction. GTP gamma S alone did not induce the contraction in the absence of Ca2+. This GTP gamma S-enhanced Ca2+ sensitivity was completely abolished by an exoenzyme of Staphylococcus aureus, named EDIN, and an exoenzyme of Clostridium botulinum, named C3, both of which are known to ADP-ribosylate the rho p21 family that belongs to the ras p21-like small GTP-binding protein superfamily. The GTP gamma S-bound form of rhoA p21 overcame the inhibitory action of EDIN. smg p21B, another small GTP-binding protein, was inactive. EDIN ADP-ribosylated a protein, which was most likely to be rho p21, in the skinned smooth muscle. The GTP gamma S-bound form of rhoA p21, but not the GDP-bound form, substituted for GTP gamma S and enhanced the Ca2+ sensitivity of the skinned smooth muscle contraction. smg p21B was inactive. These results indicate that rhoA p21 is involved in the GTP gamma S-enhanced Ca2+ sensitivity of the smooth muscle contraction.
Tetramethylammonium hydroxide (TMAH) thermochemolysis of softwood lignin provides
Z/
E-1-(3,4-dimethoxyphenyl)-2-methoxyethene (
5) and
erythro/
threo-1-(3,4-dimethoxyphenyl)-1,2,3-trimethoxypropane ...(
9), as products derived from β-aryl ether subunits. To increase the contribution of
9, Japanese cedar (
Cryptomeria japonica) wood meals were derivatized by: (1) diazomethane-methylation, (2) acetylation and (3) a combination of the methylation and acetylation. The non-derivatized (control) and derivatized wood meals were moistened with a 25% TMAH aqueous solution, dried at 80
°C for 15
min and followed by TMAH thermochemolysis at 315
°C for 4
s. Although all samples produced
5 and
9, their yields and the
9/
5 ratios differed. The diazomethane-methylated cedar provided the largest values for the
5
+
9 yield, the
9 yield and the
9/
5 ratio. The
5
+
9 yield from the diazomethane-methylated cedar was 1.17 that from the control and the
9 yield of the methylated cedar was 1.82 that of the control. The
9/
5 ratios were 1.80 and 0.71 for the diazomethane-methylated cedar and the control, respectively. Acetylated cedars provided a lower
5
+
9 yield and a lower
9/
5 ratio than the control.
Poissonian-type new radiation imager Kuroda, Kei-Ichi; Manuilov, Igor
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
1999, Letnik:
430, Številka:
2
Journal Article
Recenzirano
A new radiation imager is proposed, which is based on the recent detector technique in high-energy physics experiments; the wavelength shifter coupled to the position-sensitive photomultiplier. The ...concept model using a CsI(Na) crystal was successfully tested, and a remarkable space resolution, 1.0
mm in FWHM, with detection efficiency of ∼70% has been confirmed for 122
keV gamma rays of
57
Co
. Improvement in time resolution and possible application of the device to high-flux X-ray imaging are discussed.
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