Effect of ascorbic acid 2-0-alpha-glucoside on hydrocortisone-induced cataract formation in developing chick embryos: I. Comparison of the preventive effect of ascorbic acid derivatives

The effect of ascorbic acid 2-O-alpha-glucoside (AA-2G) on hydrocortisone (HC)-induced lens opacity in developing chick embryo was examined and compared with those of ascorbic acid (AsA) and ascorbic acid 2-phosphate (AA-2P). The opacity was dose-dependently inhibited by a single administration of 10 or 20 mumol/egg of AA-2G and by three repeated administrations of 1, 3 or 10 mumol/egg of AA-2G. AA-2G was the most effective among the three compounds. Glucose did not enhance the preventive effect of AsA against HC-induced opacity, and neither dehydro ascorbic acid nor glucose also prevented HC-induced cataract. In the histological study, we observed many small vacuoles in the nuclear region of the opaque lens treated with HC. AA-2G inhibited the formation of such vacuoles, an effect closely correlated with the prevention of cataract formation.     

Preparation and characterization of membranes with positively charged main chain from polyethylenimine

A membrane, which has positively charged groups in the polymer main chain, was prepared from polyethylenimine by crosslinking and successive alkylation. Dibromoalkane was used as a crosslinking agent. The crosslinked membrane was alkylated using methyl iodide under several conditions. Elemental and ICP emission analyses were introduced to measure the rates of alkylation and quaternization. From the membrane potential measurement, the effective charge density was estimated. The highest value was about 1.0 M, which was obtained by a prolonged alkylation time. This value was larger than that of some commercial ion exchange membranes. The effective charge density, which was obtained by the last alkylation procedure, was 10 times larger than that of the former one, though the rate of quaternizing increased by less than a factor of two. This implies that the activity constant in the membrane increased when the charge density is increased. © 1993 John Wiley & Sons, Inc.     

HighT c of liquid-quenched Bi1.6Pb0.4Sr2Ga2Cu3Ox

AlthoughT _c cannot be found for a liquid-quenched Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_x glassy sample, a highT _c is found after annealing for 24 h at 1100 K. The maximum offset temperature of the superconducting transition is 113.3 K at 2.2 × 10^–2mAmm^–2. The maximumT _{c off} is larger than that (the maximumT _{c off} is 103.4 K at 2.0 × 10^–2 mAmm^–2) of sintered specimens before liquid quenching.     

Cytokeratin expression in squamous cell carcinoma of the lung and oral cavity: an immunohistochemical study with possible clinical relevance

An extramural vessel wall hematoma occurred immediately after implanting a coronary stent in an in-stent-restenosis of the intermedius branch. Angiography showed a significant luminal reduction distal to the intervention site. Intravascular ultrasound revealed an extramural echolucent zone compressing the vessel lumen. Stent implantation compressed the hematoma and allowed adequate myocardial perfusion. This demonstrates the value of intravascular ultrasound (IVUS) in cases of unusual angiographic results which can help to manage complications after coronary intervention.     

Acyl specificity in glyceride synthesis by lactating rat mammary gland

We have investigated the possibility that the nonrandom association of fatty acids in rat milk triglycerides results from specificity of the acyl transferases in the glycerolphosphate pathway. Subcellular fractionation of lactating rat mammary gland revealed that the microsomal fraction was the most active in acylation of 3-sn-[U-¹⁴C] glycerolphosphate with various acyl-CoA's. The major products were diacylglycerolphosphate and diglyceride; no monoacylglycerolphosphate was detected. Maximum rate of acylation occurred at or below the critical micelle concentration for each acyl-CoA, indicating that only the monomeric substrate molecules were acceptable by the enzyme system. The observed acyl specificity, 16∶0>18∶0≏14∶0>12∶0>10∶0>8∶0 is consistent with the concept that, in general, milk triglycerides are synthesized by insertion of a short or medium chain fatty acid into a long chain diglyceride.     

PVDF/PMMA composite nanofiber fabricated by electrospray deposition: Crystallization of PVDF induced by solvent extraction of PMMA component

The crystallization of poly(vinylidene fluoride) (PVDF) was observed after the poly(methyl methacrylate) (PMMA) component was extracted from the PVDF/PMMA (50/50) composite nanofiber fabricated by electrospray deposition, even though the original composite showed a completely amorphous pattern in the wide‐angle X‐ray diffraction. The content of the β‐crystal form in the crystalline region depended on the PVDF/PMMA composite ratios and the type of solvents used for the extraction of the PMMA component, e.g., chloroform and toluene. Thus, the content of the β‐crystal form can be controlled by selecting the original PVDF/PMMA composition and the solvent used to extract the PMMA component. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Study on current–voltage curves of composite bipolar membrane for water and methanol solutions

The current–voltage curves of a composite bipolar membrane (CBM) were experimentally measured by inserting the thin poly(acrylonitrile) (PAN) membrane between cation‐ and anion‐exchange membranes for water and methanol solutions. In each solution system, 0.05 mol/L LiCl was used as the electrolyte. The measured results show that the thin PAN membranes enhanced the water‐ and methanol‐splitting effect. This phenomenon can be explained by the protonation–deprotonation reactions occurring between the functional group of PAN ( CN, cyano) and the water or methanol molecules in the intermediate region of the CBM. The effect of niobium alloy (Nb₃Ga), fullerene (C₆₀) and titanium oxide (TiO₂) existing in the intermediate region of the CBM was also experimentally examined in this study. It was found that the effect of these compounds on water or methanol‐splitting was not obvious. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1597–1604, 2000     

Protective effect of preservation of canine pancreas by the two-layer (University of Wisconsin solution/perfluorochemical) method against rewarming ischemic injury during implantation

Rewarming ischemia during implantation severely compromises posttransplant pancreas graft survival because the graft has already been subjected to warm and cold ischemia before implantation. The purpose of this study was to examine whether preservation of the pancreas graft by the two-layer method ameliorates rewarming ischemic injury of the graft during implantation using a canine model. After flushing with cold University of Wisconsin solution (UW), the pancreas grafts were preserved by the two-layer (UW/perfluorochemical [PFC]) method (group 1) or simple cold storage in UW (group 2) for 24 hr and then autotransplanted. In control, the pancreas grafts were flushed out with cold UW and immediately autotransplanted without preservation (group 3). After completion of vascular anastomosis, vascular clamp was not released until 90, 120, or 150 min of rewarming ischemia, including anastomosis time, had elapsed. After 90 min of rewarming ischemia, graft survival rates were 5/5, 100%, 5/5, 100%, and 5/5, 100%, in groups 1, 2, and 3, respectively. After 120 min, all the grafts in groups 2 and 3 failed (0/5, 0%, and 0/5, 0%, respectively); however, all the grafts in group 1 survived (5/5, 100%). Even after 150 min, 1 of 3 grafts in group 1 survived (1/3, 33%). After 24 hr preservation, tissue ATP levels of the grafts in group 1 were about 2-fold the reference values before harvesting (8.23 +/- 0.72 vs. 4.44 +/- 0.49 mumol/g dry weight, P < 0.05) and significantly higher compared with group 2 (8.23 +/- 0.72 vs. 1.76 +/- 0.52 mumol/g dry weight, P < 0.01). After 120 min of rewarming ischemia, tissue ATP levels in group 1 were 84% of the reference values and significantly higher compared with group 2 (3.75 +/- 0.25 vs. 1.57 +/- 0.48 mumol/g dry weight, P < 0.05). Two hours after reperfusion, ATP levels in group 1 were 42% of reference values but significantly higher compared with group 2 (1.86 +/- 0.36 vs. 1.03 +/- 0.18 mumol/g dry weight, P < 0.05). We conclude that the two-layer (UW/PFC) method ameliorates rewarming ischemic injury of the pancreas graft during implantation by increasing tissue ATP contents during preservation and consequently maintaining tissue ATP levels during implantation.