Bacillus thuringiensis: a successful insecticide with new environmental features and tidings

Bacillus thuringiensis (Bt) is known as the most successful microbial insecticide against different orders of insect pests in agriculture and medicine. Moreover, Bt toxin genes also have been efficiently used to enhance resistance to insect pests in genetically modified crops. In light of the scientific advantages of new molecular biology technologies, recently, some other new potentials of Bt have been explored. These new environmental features include the toxicity against nematodes, mites, and ticks, antagonistic effects against plant and animal pathogenic bacteria and fungi, plant growth-promoting activities (PGPR), bioremediation of different heavy metals and other pollutants, biosynthesis of metal nanoparticles, production of polyhydroxyalkanoate biopolymer, and anticancer activities (due to parasporins). This review comprehensively describes recent advances in the Bt whole-genome studies, the last updated known Bt toxins and their functions, and application of cry genes in plant genetic engineering. Moreover, the review thoroughly describes the new features of Bt which make it a suitable cell factory that might be used for production of different novel valuable bioproducts.

     

International study on Artemia LXIII. Field study of the Artemia urmiana (Günther, 1890) population in Lake Urmiah, Iran

Lake Urmiah is a large (total surface 4750–6100 km² in recent times) thalassohaline hypersaline lake (150–180 g l^–1 in the period 1994–1996), located in northwestern Iran. It is the habitat of the endemic Artemia urmiana. Over the period July 1994–January 1996 a sampling campaign was organized: 36 fixed sampling stations, distributed over the entire lake's area, were sampled weekly to determine water temperature, salinity and transparency. At each occasion a filter net was dragged over a distance of 400 m in the superficial water layer to assess the density and composition of the Artemia population. A more limited sampling campaign focused on the annual fluctuations in chlorophyll concentration and on the reproductive behaviour of the brine shrimp population. Several stages of brine shrimp survived during winter months (water temperature 3°C) at low densities. Compared to available data for the Great Salt Lake, USA, Lake Urmiah shows a low algal biomass and overall low Artemia density. The increasing grazing pressure of the developing brine shrimp population in spring seems to prevent the phytoplankton from reaching high blooming concentrations, and oviparity is the dominant reproductive mode throughout the reproductive season.     

Purification and characterization of human lysosomes from EB-virus transformed lymphoblasts

A method was developed for the isolation of unmodified lysosomes of human origin using cultured EB-virus transformed lymphoblasts. The cells were lysed carefully by repeated resuspension in buffered isotonic sucrose. A crude granular fraction derived from this lysate was further purified by isopyknic centrifugation in an isotonic colloidal silica gel gradient and by free-flow electrophoresis. The following relative specific activities (mean ± S.D.) of lysosomal marker enzymes were measured in a pooled lysosomal fraction obtained from the final electrophoresis step (representing less than 0.1% of the initial protein): β-N-acetylglucosaminidase 85.6 ± 15.5; β-galactosidase 87.6 ± 13.4; acid β-glycerophosphatase 41.7 ± 3.5; β-glucuronidase 36.6 ± 6.1. With respect to the final two enzymes the recovery within this pooled fraction was 5–6% of the initial lysate. The great differences in relative specific activities achievable may be due mainly to different extralysosomal portions of the lysosomal marker enzymes, as was found for acid β-glycerophosphatase which was largely distributed within non-lysosomal structures in lymphoblasts when studied by histochemical staining. The final fraction consisted almost exclusively of lysosomes when examined by electron microscopy. Most lysosomes appeared club-shaped immediately after cell lysis and throughout the preparation procedure. Examination by electron microscopy and measurement of the latency of lysosomal enzyme activity revealed an exceptional integrity of the lysosomal membrane. This method provides the opportunity to study highly purified lysosomes from patients with lysosomal disorders.     

Tyrosine phosphorylation of GluR2 is required for insulin-stimulated AMPA receptor endocytosis and LTD

The alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) subtype of glutamate receptors is subject to functionally distinct constitutive and regulated clathrin-dependent endocytosis, contributing to various forms of synaptic plasticity. In HEK293 cells transiently expressing GluR1 or GluR2 mutants containing domain deletions or point mutations in their intracellular carboxyl termini (CT), we found that deletion of the first 10 amino acids (834-843) selectively reduced the rate of constitutive AMPA receptor endocytosis, whereas truncation of the last 15 amino acids of the GluR2 CT, or point mutation of the tyrosine residues in this region, only eliminated the regulated (insulin-stimulated) endocytosis. Moreover, in hippocampal slices, both insulin treatment and low-frequency stimulation (LFS) specifically stimulated tyrosine phosphorylation of the GluR2 subunits of native AMPA receptors, and the enhanced phosphorylation appears necessary for both insulin- and LFS-induced long-term depression of AMPA receptor-mediated excitatory postsynaptic currents. Thus, our results demonstrate that constitutive and regulated AMPA receptor endocytosis requires different sequences within GluR CTs and tyrosine phosphorylation of GluR2 CT is required for the regulated AMPA receptor endocytosis and hence the expression of certain forms of synaptic plasticity.     

Determination of atorvastatin in human serum by reversed-phase high-performance liquid chromatography with UV detection

A rapid and sensitive high-performance liquid chromatographic method was validated and described for determination of atorvastatin in human serum. Following liquid-liquid extraction of the drug and an internal standard (sodium diclofenac), chromatographic separation was accomplished using C18 analytical column with a mobile phase consisting of sodium phosphate buffer (0.05 M, pH 4.0) and methanol (33:67, v/v). Atorvastatin and the internal standard were detected by ultraviolet absorbance at 247 nm. The average recoveries of the drug and internal standard were 95 and 80%, respectively. The lower limits of detection and quantification were 1 and 4 ng/ml, respectively, and the calibration curves were linear over a concentration range of 4-256 ng/ml of atorvastatin in human serum. The analysis performance was studied and the method was applied in a randomized cross-over bioequivalence study of two different atorvastatin preparations in 12 healthy volunteers.     

Association of Klotho gene polymorphism with hypertension and coronary artery disease in an Iranian population

Background

Klotho, possibly an age-regulating protein, is considered an important factor contributing to the lifespan and pathophysiology of hypertension and coronary artery disease (CAD). The present study was carried out aiming to investigate the association of Klotho-rs564481 (C1818T) gene polymorphism with hypertension and CAD.

Methods

A total of 286 CAD-suspicious subjects were entered into this case-control study. The polymorphism was investigated in hypertensive patients with no CAD (H-Tens, n?=?60); hypertensive patients with CAD (CAD?+?H-Tens, n?=?95); CAD patients with no hypertension (CAD, n?=?61); and non-hypertensive non-CAD subjects, which were regarded as the control group (Ctrl, n?=?70). Genotype and allele frequencies were assessed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

A significant difference was found in allele frequency of Klotho C1818T among the four research groups (P?=?0.03). It was also found that wild-type homozygote subjects were negatively associated with hypertension as compared to heterozygote ones (OR?=?0.07 [95% CI: 0.008–0.69] P?=?0.02). Moreover, in the subgroups older than 57?years old, dominant genetic model demonstrated a negative association with CAD combined with hypertension (OR?=?0.31 [95% CI: 0.10–0.95] P?=?0.04).

Conclusions

In conclusion, Klotho C1818T variant may be associated with a decreased risk of hypertension. Moreover, aging enhanced positive effects of the Klotho polymorphism on CAD combined with hypertension, indicating the possibility that the KLOTHO gene might play a part in the age-related occurrence of CAD combined with hypertension.

     

Nectary morphology in South West Asian Fritillaria (Liliaceae)

Nectaries of 3 1 taxa belonging to 4 subgenera of the genus Fritillaria are investigated by scanning electron and light microscopy. In most of the material investigated nectary cells were smaller and narrower, and less irregular in shape than those of the neighbouring tissue of the tepals. Species belonging to subgenus Rhinopetalum clearly differ from all other species. Their nectaries are deeply impressed, and the slit-like nectary orifice is bordered by two lobes, at least in the lower part densely hairy. In F. gibbosa, E karelinii and F. ariana, the flowers are ± zygomorphic as the nectary on the upper tepal is more deeply depressed than the others, and the nectary lobes are rather broad and fringed. In E stenanthera and E bucharica, nectaries are equally impressed in all tepals and the nectary orifice is bordered by narrow, unfringed ridges. The unique structure of nectaries in all species of this subgenus supports its separation from Fritillaria into a separate genus (Rhinopetalum Fisch. ex Alexand.). In the other subgenera, the nectaries are less impressed, often ± flattish, and usually linear to lanceolate or ovate, except in subgenus Petzlium where they are ± circular. One complex in subgenus Fritillaria is markedly distinguished from the rest of the subgenus: in the F. crassifolia group, the nectaries consist of a long and linear raised ridge with a median furrow. F. crassifolia ssp. poluninii is raised to specific level, E poluninii (fix) Bakhshi Khaniki & K. Persson, stat. nov. It is concluded that data on nectary morphology support the latest classification of the genus Fritillaria into subgenera and informal groups.