Production of hydroxyl radicals and alpha-dicarbonyl compounds associated with Amadori compound-Cu2+ complex degradation

The chemical properties of Amadori compounds in the presence of transition metal ions were studied, using the analogs 1-deoxy-1-n-butylamino-D-fructose (DBF) and N(alpha)-formyl-fructoselysine (fFL). The following characteristics were revealed: (a) DBF combined easily with Cu2+ (but no other transition metal ions) to form a DBF-Cu2+ complex in phosphate buffer, pH 7.4; (b) the complex was unstable, and degraded with the release of Cu+ during incubation at 37 degrees C; (c) degradation of the complex was associated with the production of hydroxyl radicals by the Fenton reaction and alpha-dicarbonyl compounds by non-autoxidative degradation; and (d) properties of DBF were similar to those of fFL. The above properties were additionally observed in glycated poly-Lys (GPL). Our findings indicate a novel mechanism for the generation of hydroxyl radicals and a-dicarbonyl compounds from Amadori adducts in the presence of Cu2+.     

Constant variation in structure and function of geometrical isomers of acitretin under natural light

Acitretin, a beneficial retinoid, was shown to undergo constant structural interconversions among its geometrical isomers (all-trans-acitretin, 9-cis-acitretin, 13-cis-acitretin, 9, 13-di-cis-acitretin, etc.) by photoisomerization under natural light. The photoisomerization was zero order reaction with an apparent velocity of 4x107 M/min under illumination by white fluorescent lamps (1, 200 lx). An equilibrium mixture of the geometrical isomers (all-trans-acitretin 20%, 9-cis-acitretin 15%, 13-cis-acitretin 30%, 9, 13-di-cis-acitretin 15%, and unidentified compounds 20%) was formed at around 30 min. Equilibrium mixtures with similar composition were obtained by photoisomerization reactions starting from other geometrical isomers. Geometrical isomers of acitretin thus formed, showed different effects to induce differentiation of human acute promyelocytic leukemia cells (HL-60 cells): activity of all-trans-acitretin (ED50, 3.2 x 10(-6) M), 9-cis-acitretin (ED50, 2.3 x 10(-5)M), 13-cis-acitretin (ED50, 1.1 x 10(-5)M), 9, 13-di-cis-acitretin (ED50, 2.6 x 10(-6)M). 9-cis-Acitretin acted synergistically with all-trans-acitretin, 13-cis-acitretin and 9, 13-di-cis-acitretin on HL-60 cells. On the other side, all-trans-acitretin, 13-cis-acitretin and 9, 13-di-cis-acitretin acted additively. Geometrical isomers of acitretin showed different effects on differentiation of human epidermal keratinocytes; expression of keratinocyte differentiation markers, keratin 1 and keratin 10, were suppressed more strongly by 9-cis-acitretin and 13-cis-acitretin as compared to all-trans-acitretin or 9, 13-di-cis-acitretin.     

4-hydroxynonenal induces glutamate cysteine ligase through JNK in HBE1 cells

Glutathione is the most abundant non-protein thiol in the cell, with roles in cell cycle regulation, detoxification of xenobiotics, and maintaining the redox tone of the cell. The glutathione content is controlled at several levels, the most important being the rate of de novo synthesis, which is mediated by two enzymes, glutamate cysteine ligase (GCL), and glutathione synthetase (GS), with GCL being rate-limiting generally. The GCL holoenzyme consists of a catalytic (GCLC) and a modulatory (GCLM) subunit, which are encoded by separate genes. In the present study, the signaling mechanisms leading to de novo synthesis of GSH in response to physiologically relevant concentrations of 4-hydroxy-2-nonenal (4HNE), an endproduct of lipid peroxidation, were investigated. We demonstrated that exposure to 4HNE resulted in increased content of both Gcl mRNAs, both GCL subunits, phosphorylated JNK1 and c-Jun proteins, as well as Gcl TRE sequence-specific AP-1 binding activity. These increases were attenuated by pretreating the cells with a novel membrane-permeable JNK pathway inhibitor, while chemical inhibitors of the p38 or ERK pathways were ineffective. These data reveal that de novo GSH biosynthesis in response to 4HNE signals through the JNK pathway and suggests a major role for AP-1 driven expression of both Gcl genes in HBE1 cells.     

Changes in unit structures and infanticide observed in Arsi geladas

In 1989 a new gelada baboon (Theropithecus gelada) population was found in Arsi, on the opposite side of the Rift Valley to that of the known gelada populations of Semien and Showa. Previous comparisons of units of the band at Gado Goro, Arsi, in the same season in consecutive years, indicated that unit structure is less stable among Arsi geladas as compared to the Semien population. Gelada units of the band at Gado-Goro were studied for 7 months in order to investigate the processes of social changes. Changes in unit structure were observed. Provisioning was carried out for 1.5 months at the beginning of the 7-month study period, in order to capture and obtain blood samples from the geladas. Following this, changes in male leadership of some units were observed, presumably as a consequence of the capture. However, natural changes also occurred. One change in unit structure occurred after a female gave birth, and changes in another unit occurred after the disappearance of the leader male. These changes involved female desertion of a unit, her subsequent transfer to a male unit, and culminated in the formation of a unit consisting of one female and one male. One successful and one attempted case of unification of units, and one case of change of a unit leader male are reported. These changes occurred among eight resident units in a period of 7 months (196 female months). Though the types of social changes were not much different from previous observations in Semien National Park, their frequencies seemed to be much higher. The characteristics of Arsi gelada social changes are proposed to be related to the small size of the units. We also describe a new confirmed case and one suspected case of infanticide, as well as one case of abortion at the time of male leader change.     

Measurement of molt-inhibiting hormone titer in hemolymph of the American crayfish,Procambarus clarkii,by time-resolved fluoroimmunoassay

In order to determine the titer of molt-inhibiting hormone (Prc-MIH) in the hemolymph of the American crayfish Procambarus clarkii, a time-resolved fluoroimmunoassay (TR-FIA) was established using specific antibodies against N-terminal and C-terminal segments of Prc-MIH. The lowest limit of detection of Prc-MIH in TR-FIA was 10 amol/assay. The Prc-MIH titers in the hemolymph were 6.53 fmol/ml at the intermolt stage and 1.25 fmol/ml at the early premolt stage. This result is consistent with the long-known hypothesis that the Y-organ is inhibited by MIH during the intermolt stage, whereas the Y-organ is activated by being freed from the inhibitory regulation of MIH.     

Physiological effects of shift work on hospital nurses

OBJECTIVE: The purpose of this study was to assess the physiological effects of shift work on the urinary excretion rates of norepinephrine, 6-sulfatoxymelatonin and estriol in hospital nurses. METHOD: Twenty-four hour urine specimens were examined on a daytime/nighttime basis for each work shift of pregnant and non-pregnant subjects. The urinary norepinephrine and 6-sulfatoxymelatonin were measured by enzyme-linked immunosorbent assay and estriol by radio-immunoassay. RESULTS: Urinary norepinephrine level during the night work was higher than the night levels of the days off and the day shift. Urinary 6-sulfatoxymelatonin level during the night work was lower than the night levels of the days off and the day shift. Urinary estriol level of pregnant subjects showed no differences among work shift and also between daytime and nighttime. CONCLUSIONS: Urinary excretion rates of norepinephrine and 6-sulfatoxymelatonin were affected by shift work both for non-pregnant and pregnant subjects. It was unlikely that urinary estriol levels in the pregnant subjects were significantly affected by shift work.     

Cloning of the fish cell line SSN-1 for piscine nodaviruses

Six cell clones were derived from the SSN-1 cell line, which is composed of a mixed cell population and persistently infected with a C-type retrovirus (SnRV). These clones were susceptible to 4 piscine nodavirus strains belonging to different genotypes (SJNNV, RGNNV, TPNNV and *BFNNV [striped jack, redspotted grouper, tiger puffer and barfin flounder nervous necrosis viruses]). Three clones, designated A-6, E-9, and E-11, were highly permissive to nodavirus infection and production. The virus-induced cytopathic effects appeared as cytoplasmic vacuoles and intensive disintegration at 3 to 5 d post-incubation. These observations were highly reproducible and formed the basis for a successful virus titration system. Quantitative analysis using the cloned E-11 cell line clearly revealed differences in the optimal growth temperatures among the 4 genotypic variants: 25 to 30 degrees C for strain SGWak97 (RGNNV), 20 to 25 degrees C for strain SJNag93 (SJNNV), 20 degrees C for strain TPKag93 (TPNNV), and 15 to 20 degrees C for strain JFIwa98 (BFNNV). Electron microscopy demonstrated SnRV retrovirus particles only in A-6 and E-9 cells, but PCR amplification for the pol gene and LTR region of the proviral DNA indicated the presence of the retrovirus in the other clones, including E-11. The cell clones obtained in the present study will be more useful for qualitative and quantitative analyses of piscine nodaviruses than the SSN-1 cell line.     

Cloning and characterization of erythroid-specific DNase I-hypersensitive site in human rhesus-associated glycoprotein gene

Rhesus-associated glycoprotein is a critical co-factor in the expression of rhesus blood group antigens. We identified and cloned an erythroid-specific major DNase I-hypersensitive site located about 10 kilobases upstream from the translation start site of the RHAG gene. A short core enhancer sequence of 195 base pairs that corresponded with the major hypersensitive site and possessed position- and orientation-independent enhancer activity in K562 cells. In vitro DNase I footprint analysis revealed four protected regions in the core enhancer; two GATA motifs, an Ets-like motif and an unknown motif. The GATA motifs bound GATA-1 and mutagenesis analysis revealed that the proximal one is critical for the enhancing activity. Homology plot analysis using the 5' sequence of the mouse RHAG gene revealed four homologous stretches and multiple insertions of repetitive sequences among them; four LINE/L1 and four Alu in the human and as well as one LINE/L1 and one LTR/MaLR in the mouse gene. The highly conservative enhancer region was flanked by SINE and LINE/L1 in both species. These results suggest that the 5'-flanking sequence of RHAG gene is a preferable target sequence for retroviral transposition and that the enhancer was inserted in the same manner, resulting in the acquisition of erythroid dominant expression.     

TCR-independent activation of extrathymically developed, self antigen-specific T cells by IL-2/IL-15

Naive intrathymically developed T cells, which express foreign Ag-specific TCR, do not express IL-2R. After antigenic stimulation, they express high affinity IL-2R, which enables IL-2 to be used as an autocrine growth factor. On the contrary, extrathymically developed T cells, which express self Ag-specific TCR but are unresponsive to antigenic stimulation, spontaneously express low affinity IL-2R. In this study, we compared the responses of these two subsets of T cells to IL-2R stimulation and examined the influences of TCR-mediated signaling on the responses. IL-2 or IL-15 augmented the proliferative response of Ag-stimulated, intrathymically developed T cells. On the other hand, extrathymically developed T cells proliferated in response to IL-2 or IL-15, independently of Ag stimulation. Furthermore, both IL-2 and IL-15 induced IFN-gamma production of these T cells, which is strikingly augmented by the presence of IL-12. These results revealed functional differences between intrathymically developed, foreign Ag-specific T cells and extrathymically developed, self Ag-specific T cells. The latter can be activated by some inflammatory cytokines, in an Ag-independent manner, similar to NK cells.     

Involvement of angiotensin II and endothelin-1 in the development of submandibular gland hypertrophy in response to isoproterenol in rats

We investigated whether angiotensin II (Ang II) and endothelin-1(ET-1) are involved in submandibular hypertrophy in response to repeated treatment with isoproterenol (ISO) in rats. The immunoreactive Ang II (IRAng II) and immunoreactive ET-1 (IRET-1) contents of ISO-induced hypertrophy were significantly higher than those of control glands. Treatment of isolated gland tissues with ISO (1 microM) or dobutamine (1 microM) caused significant increases in the IRAng II and IRET- 1 contents of the glands compared with controls. These increases were suppressed by pretreatment with enalapril (3 microM) or captopril (3 microM). Treatment with Ang II (10 microM) also caused an increase in IRET-1 content. Our findings suggest that Ang II and ET-1 are involved in the submandibular gland hypertrophy that develops in rats repeatedly treated with ISO, and that these biologically active peptides may act as growth factors. They also imply that the tissue renin-angiotensin system and Ang II specific receptors are present in the submandibular glands.