Evaluation of antagonistic activities of Bacillus subtilis and Bacillus licheniformis against wood-staining fungi: In vitro and in vivo experiments

The antifungal activity of bacterial strains Bacillus subtilis EF 617317 and B. licheniformis EF 617325 was demonstrated against sapstaining fungal cultures Ophiostoma flexuosum, O. tetropii, O. polonicum, and O. ips in both in vitro and in vivo conditions. The crude active supernatant fractions of 7 days old B. subtilis and B. licheniformis cultures inhibited the growth of sapstaining fungi in laboratory experiments. Thermostability and pH stability of crude supernatants were determined by series of experiments. FT-IR analysis was performed to confirm the surface structural groups of lipoproteins present in the crude active supernatant. Partial purification of lipopeptides present in the crude supernatant was done by using Cellulose anion exchange chromatography and followed by Sephadex gel filtration chromatography. Partially purified compounds significantly inhibited the sapstaining fungal growth by in vitro analysis. The lipopeptides responsible for antifungal activity were identified by electrospray ionization mass spectrometry after partial purification by ion exchange and gel filtration chromatography. Four major ion peaks were identified as m/z 1023, 1038, 1060, and 1081 in B. licheniformis and 3 major ion peaks were identified as m/z 1036, 1058, and 1090 in B. subtilis. In conclusion, the partially purified lipopeptides may belong to surfactin and iturin family. In vivo analysis for antifungal activity of lipopeptides on wood was conducted in laboratory. In addition, the potential of extracts for fungal inhibition on surface and internal part of wood samples were analyzed by scanning electron microscopy.     

The use of Box-Behnken design of experiments to study in vitro salt tolerance by Pisolithus tinctorius

The ectomycorrhizal fungus Pisolithus tinctorius was grown in vitro with different concentrations and combinations of three different sodium salts viz., sodium chloride, sodium sulphate and trisodium citrate (NaCl, Na₂SO4 and Na₃C₆H₅O₇) for 30 days. At the end of the experiment the mycelial biomass and protein content of the fungus was evaluated. Based on the salts tested the combination of NaCl and Na₂SO₄ in optimum concentrations actually promoted the growth of P. tinctorius. Box-Behnken design with three variables like NaCl, Na₂SO₄ and Na₃C₆H₅O₇ was used to identify a significant correlation between the effect of these variables on mycelial biomass production. The experimental values are in good agreement with predicted values, the correlation coefficient being 0.9880.     

The Chernobyl fallout in Salzburg/Austria and its effect on blood chromosomes

The radioactive fallout of the Chernobyl accident caused an increase in radiation dose of 20 to 110 per cent over the normal environmental burden to the inhabitans of Salzburg City in Austria (in a distance of about 1300 km from the accident). The structural chromosome aberration in the lymphocytes of the peripheral blood of 15 test-persons have been investigated one year after the accident. From two of these we know also the aberration frequencies before the accident which were significantly lower. The results from all test persons were pooled according to their Cs137 and Cs134 content, measured by whole body counter. Their mean additional blood doses from the incorporated caesium plus the external fallout radiation were 0.23, 0.36 and 0.55 mGy/yr. The aberration frequencies increased with dose. The slope of the best straight-line through the points was 2.0 +/- 0.7 total chromosome type aberrations in 100 metaphases per mGy/yr. This result fits in well with former investigations of persons with individually calculated radiation burden from the environment. The sharp increase with dose at this low level is not compatible with values extrapolated from high doses. The usual dose assessment based on chromosome aberrations extrapolated from high to low doses is therefore not possible in the range considered in this investigation.     

A simple device to study the role of seed mycoflora in the root region of crop plants

Summary A simple device was used to study the role of seed mycoflora in the root region of some crop plants and it was found that the fungi present in the root region originated from the soil rather than from the seeds.Memoir No. 190 from the Centre for Advanced Studies in Botany, University of Madras, Madras-600 005, India.     

In vitro activity of diethylcarbamazine on the infective larvae, microfilariae and adult worms of Breinlia sergenti

In vitro activity of diethylcarbamazine on the infective larvae, microfilariae and adult worms of Breinlia sergenti. International Journal for Parasitology. 3: 803–807. The action of diethylcarbamazine, on the infective larvae, the microfilariae and the adult worms of Breinlia sergenti, occurring in slow loris (Nycticebus coucang) is described. The drug immobilized all the three stages of the parasite. In the case of the adult worms an initial increase in the tone of the musculature followed by flaccid paralysis was observed.     

Alteration of apoptotic signaling molecules as a function of time after radiation in human neuroblastoma cells

Ascertaining the time-dependent regulation of induced apoptosis and radioresistance is important to understand the relationship between the level of spontaneous apoptosis in cells and their radiosensitivity. Accordingly, we investigated the time-dependent expression of apoptosis related genes and radioresistance in neuroblastoma cells. Serum-starved human SK-N-MC cells were exposed to low linear energy transfer (LET) radiation (2 Gy) and incubated for 15, 30, 45 min, and 48 h. Radioresistance was investigated by examining the NFκB DNA-binding activity, cellular toxicity, DNA fragmentation, and expression of apoptotic signal transduction molecules. NFκB DNA binding activity was analyzed using electrophoretic mobility shift assay (EMSA). Cellular toxicity was measured using MTT assay. DNA fragmentation was quantified by labeling with fluorescein-conjugated deoxynucleotides. Microarray analysis was performed using cDNA microarray and relative gene expression was measured as % GAPDH and, subsequently validated using Q-PCR. Induction of NFκB analyzed using EMSA showed an increased DNA-binding activity at all time points investigated. Induced DNA fragmentation was observed after 15, 30, and 45 min post-radiation. Relatively, induced fragmentation was reduced after 48 h. Compared to the untreated controls cellular toxicity was induced with low LET radiation after 15, 30, and 45 min. Conversely, cytotoxicity was relatively less at 48 h after low LET radiation. Microarray analysis after low LET radiation revealed time-dependent modulation of apoptosis-related genes that are involved in radio-adaptation, spontaneous apoptosis-related early-responsive genes and late response genes. These results suggest that the time-dependent regulation of apoptotic response may determine the relationship between the level of spontaneous apoptosis in cells and their radiosensitivity.     

Lysophosphatidic acid induces interleukin-13 (IL-13) receptor alpha2 expression and inhibits IL-13 signaling in primary human bronchial epithelial cells

Interleukin-13 (IL-13), a Th2 cytokine, plays a pivotal role in pathogenesis of bronchial asthma via IL-13 receptor alpha1 (IL-13Ralpha1) and IL-4 receptor alpha (IL-4Ralpha). Recent studies show that a decoy receptor for IL-13, namely IL-13Ralpha2, mitigates IL-13 signaling and function. This study provides evidence for regulation of IL-13Ralpha2 production and release and IL-13-dependent signaling by lysophosphatidic acid (LPA) in primary cultures of human bronchial epithelial cells (HBEpCs). LPA treatment of HBEpCs in at imedependent fashion increased IL-13Ralpha2 gene expression without altering the mRNA levels of IL-13Ralpha1 and IL-4Ralpha. Pretreatment with pertussis toxin (100 ng/ml, 4 h) or transfection of c-Jun small interference RNA or an inhibitor of JNK attenuated LPA-induced IL-13Ralpha2 gene expression and secretion of soluble IL-13Ralpha2. Overexpression of catalytically inactive mutants of phospholipase D (PLD) 1 or 2 attenuated LPA-induced IL-13Ralpha2 gene expression and protein secretion as well as phosphorylation of JNK. Pretreatment of HBEpCs with 1 microM LPA for 6 h attenuated IL-13-but not IL-4-induced phosphorylation of STAT6. Transfection of HBEpCs with IL-13Ralpha2 small interference RNA blocked the effect of LPA on IL-13-induced phosphorylation of STAT6. Furthermore, pretreatment with LPA (1 microM, 6 h) attenuated IL-13-induced eotaxin-1 and SOCS-1 gene expression. These results demonstrate that LPA induces IL-13Ralpha2 expression and release via PLD and JNK/AP-1 signal transduction and that pretreatment with LPA down-regulates IL-13 signaling in HBEpCs. Our data suggest a novel mechanism of regulation of IL-13Ralpha2 and IL-13 signaling that may be of physiological relevance to airway inflammation and remodeling.     

Inhibition of histone deacetylase causes emphysema

In patients with chronic obstructive pulmonary disease (COPD), histone deacetylase (HDAC) expression and activity are reduced in the lung tissue. However, whether HDAC activity controls the maintenance of the lung alveolar septal structures has not been investigated. To explore the consequences of HDAC inhibition and address the question of whether HDAC inhibition causes lung cell apoptosis and emphysema, male Sprague-Dawley rats and human pulmonary microvascular endothelial cells (HPMVEC) were treated with trichostatin A (TSA), a specific inhibitor of HDACs. Chronic TSA treatment increased the alveolar air space area, mean linear intercept, and the number of caspase-3-positive cells in rat lungs. TSA suppressed hypoxia-inducible factor-1α (HIF-1α), VEGF, and lysyl oxidase (LOX) and increased microtubule-associated protein-1 light chain 3 (LC3), p53, and miR34a microRNA expression in both rat lungs and cultured HPMVEC. Gene silencing of HDAC2 using small interfering RNA (siRNA) in cultured HPMVEC resulted in the suppression of HIF-1α, VEGF, and LOX and an increase of p53 expression. These data indicate that HDAC inhibition causes emphysema and that HDAC-dependent mechanisms contribute to the maintenance of the adult lung structure. Our results also suggest that the increase in apoptosis, as a consequence of HDAC inhibition, is associated with decreased VEGF and HIF-1α expression.