Changes in N-acetyl-beta-D-glucosaminidase activity in the urine and urinary albumin excretion in magnesium deficient rats

To discover the details of the effects of magnesium (Mg) deficiency on kidney function, the course of changes in N-acetyl-beta-D-glucosaminidase (NAG) activity in the urine and in urinary albumin excretion were examined in rats fed a Mg-deficient diet. NAG activity in the urine and urinary albumin excretion in rats fed the Mg-deficient diet significantly increased from 7 d until the end of the feeding period. We suggest that Mg-deficient diet rapidly induces kidney function insufficiency.     

Possible roles of ENaC and Cl(-) channel in wound closure in Xenopus laevis embryos

Our previous report showed that rapid wound closure in Xenopus laevis embryos was associated with a decrease in the extracellular concentration of either Na(+) or Cl(-) ions. In this study, we examined the wound closure in Xenopus embryos when epithelial Na(+) channel (ENaC), Na(+)/K(+) ATPase (Na(+) pump) or CICs (members of Cl(-) channel) were blocked by each specific inhibitor. Blockage of ENaC and CIC restricted the rate of wound closure during the first 30 min PW and during the subsequent period, respectively. In contrast, inhibition of Na(+) pump had no effect on the rate of wound closure. Furthermore, simultaneous administration of both ENaC and CIC inhibitors resulted in the cumulative reduction of wound closure. Thus, it is plausible that these ion channels play active roles in wound closure in Xenopus embryos. NPPB is known to inhibit both CIC-2 and CIC-3. Immunohistochemical experiments showed that CIC-3, but not CIC-2, was expressed in Xenopus embryos, suggesting that the reduced wound closure by NPPB was due to blockage of CIC-3. A local enhancement of CIC-3 expression at the leading edge of the wounded epidermis was found to be specific to closing wounds that were kept in 10% NAM. An in vitro wounding assay also showed a pattern of CIC-3 expression at the margin of the scratch wound comparable to the results in vivo. These findings suggest that intracellular translocation of CIC-3 is involved in wound closure. We propose that the ion channels, including CIC-3, play a crucial role in wound closure in Xenopus embryos.     

The relationship between photosystem II efficiency and quantum yield for CO(2) assimilation is not affected by nitrogen content in apple leaves

Bench-grafted Fuji/M.26 apple (Malus domestica Borkh.) trees were fertigated with different concentrations of nitrogen by using a modified Hoagland's solution for 45 d. CO(2) assimilation and photosystem II (PSII) quantum efficiency in response to incident photon flux density (PFD) were measured simultaneously in recent fully expanded leaves under low O(2) (2%) and saturated CO(2) (1300 micromol mol(-1)) conditions. A single curvilinear relationship was found between true quantum yield for CO(2) assimilation and PSII quantum efficiency for leaves with a wide range of leaf N content. The relationship was linear up to a quantum yield of approximately 0.05 mol CO(2) mol(-1) quanta. It then became curvilinear with a further rise in quantum yield in response to decreasing PFD. This relationship was subsequently used as a calibration curve to assess the rate of non-cyclic electron transport associated with Rubisco and the partitioning of electron flow between CO(2) assimilation and photorespiration in different N leaves in response to intercellular CO(2) concentration (C(i)) under normal O(2) conditions. Both the rate of non-cyclic electron flow and the rate of electron flow to CO(2) or O(2) increased with increasing leaf N at any given C(i). The percentage of non-cyclic electron flow to CO(2) assimilation, however, remained the same regardless of leaf N content. As C(i) increased, the percentage of non-cyclic electron flow to CO(2) assimilation increased. In conclusion, the relationship between PSII quantum efficiency and quantum yield for CO(2) assimilation and the partitioning of electron flow between CO(2) assimilation and photorespiration are not affected by N content in apple leaves.     

Quantitative and antioxidative behavior of Trolox in rats’ blood and brain by HPLC‐UV and SMFIA‐CL methods

Trolox, a water‐soluble vitamin E analogue has been used as a positive control in Trolox equivalent antioxidant capacity and oxygen radical antioxidant capacity assays due to its high antioxidative effect. In this study, the ex vivo antioxidative effects of Trolox and its concentration in blood and brain microdialysates from rat after administration were evaluated by newly established semi‐microflow injection analysis, chemiluminescence detection and HPLC‐UV. In the administration test, the antioxidative effect of Trolox in blood and brain microdialysates after a single administration of 200 mg/kg of Trolox to rats could be monitored. The antioxidative effects in blood (12.0 ± 2.1) and brain (8.4 ± 2.1, × 10³ antioxidative effect % × min) also increased. Additionally, the areas under the curve (AUC)s_0–360 (n = 3) for blood and brain calculated with quantitative data were 10.5 ± 1.2 and 9.7 ± 2.5 mg/mL × min, respectively. This result indicates that Trolox transferability through the blood–brain barrier is high. The increase in the antioxidative effects caused by Trolox in the blood and brain could be confirmed because good correlations between concentration and antioxidative effects (r ≥ 0.702) were obtained. The fact that Trolox can produce an antioxidative effect in rat brain was clarified. Copyright © 2015 John Wiley & Sons, Ltd.     

Elimination of Mange Mites <Emphasis Type="Italic">Sarcoptes scabiei</Emphasis> var. <Emphasis Type="Italic">suis</Emphasis>from Two Naturally Infested Danish Sow Herds Using a Single Injection Regime with Doramectin

Attempts to eliminate Sarcoptes scabiei var. suis were made in 2 naturally infested sow herds, by intramuscular (IM) injection of doramectin (Dectomax^®, Pfizer, New York, USA). A single injection strategy was used. In one of the herds, the environment was treated with an acaricide following dry cleaning of floors, walls and equipment. In the second herd, no environmental treatment was performed. Results were measured by skin lesion scoring, ear scrapings to show Sarcoptes scabiei var. suis, and calculating rubbing index throughout the observation period of 20 months following treatment. Skin lesion scores decreased and stayed low following treatment for the entire observation period. Live Sarcoptes scabiei var. suis mites were isolated prior to treatment from both herds, but not following treatment. Rubbing index decreased following treatment, but was occasionally at or above 0.4. The results of these studies indicate that elimination of Sarcoptes scabiei var. suis from 2 naturally infested herds was successful, using doramectin in a single injection strategy. Precautions must be taken to ensure adequate dosing of every pig, and to avoid reinfestation due to poor biosecurity.     

Synthesis and characterization of radioiodinated 3-phenethyl-2-indolinone derivatives for SPECT imaging of survivin in tumors

Survivin, overexpressed in most cancers, is associated with poor prognosis and resistance to radiation therapy and chemotherapy. Herein, we report the synthesis of three 3-phenethyl-2-indolinone derivatives and their application as in vivo imaging agents for survivin. Of these, 3-(2-(benzo[d][1,3]dioxol-5-yl)-2-oxoethyl)-3-hydroxy-5- iodoindolin-2-one (IPI-1) showed the highest binding affinity (K_d?=?68.3?nM) to recombinant human survivin, as determined by quartz crystal microbalance (QCM). In vitro studies demonstrated that the [¹²⁵I]IPI-1 binding in survivin-positive MDA-MB-231 cells was significantly higher than that in survivin-negative MCF-10A cells. In addition, uptake of [¹²⁵I]IPI-1 by MDA-MB-231 cells decreased in a dose-dependent manner in the presence of the high-affinity survivin ligand S12; this is indicative of specific binding of [¹²⁵I]IPI-1 to cellular survivin protein in vitro. Biodistribution studies in MDA-MB-231 tumor-bearing mice demonstrated the moderate uptake of [¹²⁵I]IPI-1 in the tumor tissue (1.37%?ID/g) at 30?min that decreased to 0.32%?ID/g at 180?min. Co-injection of S12 (2.5?mg/kg) slightly reduced tumor uptake and the tumor/muscle ratio of [¹²⁵I]IPI-1. Although further structural modifications are necessary to improve pharmacokinetic properties, our results indicate that PI derivatives may be useful as tumor-imaging probes targeting survivin.     

Regulation of TRH release by the cultured neonate rat pancreas

The TRH secretory responsiveness of the pancreatic islet cell clusters from newborn rat in organ culture was studied. Basal TRH secretion was stable over a 9-day period. The response to various secretagogues was tested on day 4. TRH secretion was stimulated by high potassium-induced depolarization and also through both cAMP and protein kinase-C dependent pathways. Like insulin, TRH release was stimulated by glucose and arginine and inhibited by somatostatin. These data suggest the existence of a common mechanism for TRH and insulin secretion by the pancreatic β-cells.     

Detection of oxidative stress-induced mitochondrial DNA damage using fluorescence correlation spectroscopy

Using fluorescence correlation spectroscopy (FCS), we tested the feasibility of rapid detection of oxidative damage of mitochondrial DNA (mtDNA) in a small volume. The complete mtDNA genome was amplified by long polymerase chain reaction (LPCR), and the product was fluorescently labeled with an intercalating dye, YOYO-1. The fluorescence autocorrelation function was analyzed using a simple two-component model with the diffusion time of 0.21 ms for the LPCR primer and 18 ms for the mtDNA LPCR product. When human embryonic kidney 293 (HEK-293) cells were exposed to 0.4 mM H2O2, the fraction of the mtDNA LPCR product decreased significantly. In contrast, the fraction of the nuclear-encoded beta-globin LPCR product remained unchanged. The analysis time of FCS measurement was very short (5 min) compared with that of gel electrophoresis (3 h). Thus, FCS allowed the rapid detection of the vulnerability of mtDNA to oxidative stress within a small volume element at the subfemtoliter level in solution. These results suggest that the LPCR-FCS method can be used for epidemiological studies of diseases caused by mtDNA damage.