The spontaneous growth response of maize coleoptile segments and the change in tissue 8

Decapitated segments from maize (Zea mays L.) coleoptiles orientedvertically in an upright position show a strong spontaneousgrowth response (SGR) 3 h after decapitation. The latent periodof the SGR is markedly reduced when these segments are orientedin an inverted position. Coleoptile segments with intact tipsexhibit a weak and transient SGR in the vertical upright orientation.However, in the inverted orientation, these segments show atypical SGR. The data are inconsistent with the current hypothesisthat the SGR is caused by a time-dependent increase in tissuesensitivity to auxin. The parallel increase in membrane potentialdifference and growth rate during the time-course of the SGRindicates a possible role for PM H⁺-ATPase in the establishmentof the SGR in maize coleoptile segments. Key words: Auxin, spontaneous growth response, membrane potential, plasma membrane H⁺-ATPase, Zea mays L.     

Stimulation of adventitious root formation in non-woody stem cuttings by uridine

Uridine strongly stimulated adventitious root formation in stem cuttings of sunflower (Helianthus annuus L.), mung bean (Vigna radiata L.) and common bean (Phaseolus vulgaris L.). A dose response curve of uridine induced rooting showed that the optimum concentration of uridine was 0.1 µM. At all concentrations employed, uridine had no significant effect on root elongation. The rooting response of stem cuttings to the optimal concentration of indole-3-butyric acid (10 µM) in combination with 0.1 µM uridine did not significantly differ from their response to either of these compounds when applied alone. However, the rooting response of the cuttings to sub-optimal IBA (0.01 µM) was significantly stimulated by uridine. These findings suggested that uridine may have stimulated rooting by increasing the sensitivity of the rooting tissue to auxin.     

The impact of N- and O-glycosylation on the functions of Glut-1 transporter in human thyroid anaplastic cells

It has been previously shown that glucose transporter Glut-1 expression was detectable by immunostaining in tissue sections from anaplastic carcinoma, but not in normal thyroid tissue. Using human thyroid anaplastic carcinoma cells, we studied the mechanism by which Glut-1 molecules are translocated from the endoplasmic reticulum to the cell surface. The contribution of N- and O-linked glycans for the translocation and activity of Glut-1 transporter is emphasized. The inhibition of N-glycosylation with tunicamycin (TM) led to a 50% decrease in glucose transport while glycosylated and unglycosylated forms of Glut-1 were found at the cell surface. However, the inhibition of N-linked oligosaccharide processing with deoxymannojirimycin (dMJ) and swainsonine (SW) influenced neither the intracellular trafficking nor the activity of the transporter. On the other hand, Glut-1 bound to the O-linked glycan-specific lectin jacalin and the O-glycosylation inhibitor benzyl-N-acetylgalactosamine dramatically inhibited glucose transport. These results show that O- and N-linked oligosaccharides arbored by Glut-1 are essential for glucose transport in anaplastic carcinoma cells. The quantitative and qualitative alterations of Glut-1 glycosylation and the increase in glucose transport are associated with the anaplastic phenotype of human thyroid cells.     

Preatherosclerosis and adiponectin subfractions in obese adolescents

We evaluated total adiponectin, high-molecular weight (HMW), medium-molecular weight (MMW), low-molecular weight (LMW) adiponectin subfractions, clinical parameters, routine lab parameters, lipids, metabolic, inflammatory biomarkers, and intima-media thickness (IMT) of common carotid arteries in 70 obese juveniles and adolescents with preatherosclerosis and 55 normal weight controls of similar age and gender distribution. Compared with the controls, the obese probands had a significantly increased IMT (P < 0.001) and elevated ultra-sensitive C-reactive protein (P < 0.001) indicating early vascular burden. Total and HMW adiponectin were significantly decreased in the obese cohort. The ratio between HMW and total adiponectin was significantly decreased in obese probands whereas the LMW/total adiponectin ratio was increased. Overall, total-, HMW, and MMW adiponectin were significantly negatively correlated with carotid IMT. The HMW/total adiponectin ratio correlated significantly negatively, and the LMW/total adiponectin ratio significantly positively with the IMT. Furthermore, HMW adiponectin was significantly positively correlated with high-density lipoprotein (HDL)-cholesterol and serum apolipoprotein A1, and negatively with BMI, triglycerides, homeostatic model assessment (HOMA)-index, leptin, liver transaminases, and uric acid. This remained stable after controlling for gender. Multiple regression analysis of body measures and all other lab parameters showed the strongest correlation between HMW adiponectin and carotid IMT (beta = -0.35, P < 0.001). Taken together, our study provides the first evidence that preatherosclerosis in obese juveniles and adolescents is associated with altered subfractions of adiponectin, whereas after multiple testing the HMW subfraction showed a better correlation to IMT compared with total adiponectin.     

Compatibility of Verticillium lecani (Zimm.) with several pesticides

The entomopathogenic fungus, Verticillium lecanii (Zimm.) Viégas is a widespread hyphomycete consisting of a heterogeneous species aggregate. Conidia survival may be effected by environmental factors or by bio-pesticides and chemical products used to protect crop plants. In this research compatibility of mentioned fungi with imidachlopride, flufenoxuron, teflubenzuron+phozalone, endosulfan, amitraz, and effect of these pesticides on vegetative growth of the fungus were studied. The formulations of pesticides were tested in three concentration (mean concentration-MC, half MC and twice the MC) and using Duncan multiple range test, treatment were grouped. Effects of the pesticides on V. lecanii vegetative growth in concerned results have shown that almost all formulations studies significantly inhibition fungal development. The results indicated that flufenoxuron (at three concentrations), teflubenzuron+phozalone (at MC and twice the MC), induced levels of vegetative growth inhibition higher than 68%. Only data on amitraz and imidachlopride (at half MC) were not significantly different from the control, which is indicated the compatible formulations with V. lecanii. These formulations could be used simultaneously with this entomopathogenic in integrated pest management.     

Development and reproduction of Adalia bipunctata on factitious and artificial foods

The native coccinellid Adalia bipunctata (L.) (Coleoptera: Coccinellidae) may be an alternative to exotic species like Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) for the biological control of aphid pests in Europe. The availability of adequate factitious or artificial foods may help optimize its mass production. This study examines the nutritional value of Ephestia kuehniella Zeller (Lepidoptera: Phycitidae) eggs plus bee pollen, pea aphids Acyrthosiphum pisum (Harris) (Hemiptera: Aphididae) and mixtures of bee pollen and cysts of Artemia franciscana Kellogg (Branchiopoda: Artemiidae) and/or a lyophilized artificial diet based on bovine meat and liver. Reproducing adults of A. bipunctata were obtained on all diets tested, but immature survival, adult weights, development times and reproductive rates differed among diets. Over 84% of first instars fed on E. kuehniella eggs plus pollen or aphids survived to adulthood. Feeding predator larvae on pollen combined only with A. franciscana cysts or artificial diet yielded 40–55% immature survival, but survival increased to 74% when all of these components were mixed. Adult weights of A. bipunctata on the mixtures of pollen, A. franciscana cysts and/or artificial diet were 55–75% of those on aphids or on E. kuehniella eggs plus pollen. Lifetime fecundity was superior on E. kuehniella eggs plus pollen (1,864 eggs) to that on the other diets (264–889 eggs). The use of mixtures of plant and animal foods for A. bipunctata and other predators may contribute to increasing the cost-effectiveness of commercial mass production by reducing inputs of natural prey like aphids, or of nutritious but expensive factitious foods like lepidopteran eggs.     

Immunization with an apoptotic cell-binding protein recapitulates the nephritis and sequential autoantibody emergence of systemic lupus erythematosus

The initial events predisposing to loss of tolerance in patients with systemic lupus erythematosus (SLE) are largely unknown, as are the events that precipitate the transition from preclinical to overt disease. We hypothesized that induction of murine SLE would require tipping the balance between tolerance and immunity in two ways: 1) an immunogen that could take advantage of apoptotic cells as a scaffold for epitope spread, and 2) an immune activator that would generate a strong and persistent T cell response to the inciting immunogen. We show that immunization of C57BL/6 and BALB/c mice with human beta(2)-glycoprotein I, an apoptotic cell-binding protein, in the presence of LPS induces a long-lived, potent response to beta(2)-glycoprotein I that results in epitope spread to multiple SLE autoantigens. SLE-specific autoantibodies emerged in a sequential manner that recapitulated the order seen in human SLE. Moreover, immunized mice developed overt glomerulonephritis closely resembling human lupus nephritis.     

Mechanisms of resistance to decitabine in the myelodysplastic syndrome

Purpose

The DNA methylation inhibitor 5-aza-2′-deoxycytidine (DAC) is approved for the treatment of myelodysplastic syndromes (MDS), but resistance to DAC develops during treatment and mechanisms of resistance remain unknown. Therefore, we investigated mechanisms of primary and secondary resistance to DAC in MDS.

Patients and Methods

We performed Quantitative Real-Time PCR to examine expression of genes related to DAC metabolism prior to therapy in 32 responders and non-responders with MDS as well as 14 patients who achieved a complete remission and subsequently relapsed while on therapy (secondary resistance). We then performed quantitative methylation analyses by bisulfite pyrosequencing of 10 genes as well as Methylated CpG Island Amplification Microarray (MCAM) analysis of global methylation in secondary resistance.

Results

Most genes showed no differences by response, but the CDA/DCK ratio was 3 fold higher in non-responders than responders (P<.05), suggesting that this could be a mechanism of primary resistance. There were no significant differences at relapse in DAC metabolism genes, and no DCK mutations were detected. Global methylation measured by the LINE1 assay was lower at relapse than at diagnosis (P<.05). On average, the methylation of 10 genes was lower at relapse (16.1%) compared to diagnosis (18.1%) (P<.05).MCAM analysis showed decreased methylation of an average of 4.5% (range 0.6%–9.7%) of the genes at relapse. By contrast, new cytogenetic changes were found in 20% of patients.

Conclusion

Pharmacological mechanisms are involved in primary resistance to DAC, whereas hypomethylation does not prevent a relapse for patients with DAC treatment.