Insecticidal effect of plant extracts on common pistachio psylla,Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae)

The common pistachio psylla, Agonoscena pistaciae (Hemiptera: Aphalaridae) is one of the most detrimental pests to pistachio trees. Nowadays various pesticides are used to control the common pistachio psylla, but extensive pesticide spraying against this pest over a period of several years has overpowered its natural enemies. The plant’s byproducts come as an alternative ecologically more compatible in substitution to the synthetic insecticides. This work aims to evaluate the insecticidal potential of herbal extracts of fruit peels of Citrus sinensis and Citrus reticulata, seeds of C. sinensis and Rubia tinctorum, and leaves of Lawsonia inermis against common pistachio psylla. Five concentration 40, 47, 56, 67 and 80 µl/ml, of these plant extracts were sprayed on the fifth instar nymphs of common pistachio psylla by Potter Spray Tower under laboratory conditions (26?±?2?°C, 60–70% RH and a photoperiod of 16L: 8D h). Results showed significant differences among the treatments of the plant extracts and between the concentrations. The LC₅₀ values of C. sinensis peels, C. reticulata peels, C. sinensis seeds, R. tinctorum seeds and L. inermis leaves were 62.04, 38.84, 43.60, 59.01 and 33.99 µl/ml, respectively. Also, all extracts showed the greatest mortality effect in 80 µl/ml concentration. According to these results, these plant extracts may use as herbal pesticides chemical control programme of common pistachio psylla.     

Crystallization of membrane proteins from media composed of connected-bilayer gels

The use of hydrated-lipid gels in which the bilayer is an infinitely periodic (or at least continuous), three-dimensional structure offers a relatively new approach for the crystallization of membrane proteins. While excellent crystals of the Halobacterial rhodopsins have been obtained with such media, success remains poor in extending their use to other membrane proteins. Experience with crystallization of bacteriorhodopsin has led us to recognize a number of improvements that can be made in the use of such hydrated-gel media, which may now prove to be of general value for the crystallization of other membrane proteins.     

Membrane-protein stability in a phospholipid-based crystallization medium

Protein stability is a crucial factor to consider when attempting to crystallize integral membrane proteins. Cubic phase, or in meso, lipid-bilayer crystallization media are thought to provide native-like environments that should facilitate membrane protein crystallization by helping to stabilize the native protein conformation for the duration of the crystallization process. While excellent crystals of bacteriorhodopsin (bR) and other Halobacterial rhodopsins have been obtained in lipid-bilayer gels formed with monoglycerides, success remains elusive in the general application of such media to other membrane proteins. Additionally, we have noted that some mutants of bR are highly unstable in gels formed with monoolein. Phosphatidylethanolamines (PE) and derivatives of PE represent another class of lipids that can form connected-bilayer gels. When wildtype bR and a labile bR mutant were reconstituted into this phospholipid gel, spectroscopy showed that the protein is both more stable and has improved conformational homogeneity as compared to gels formed using monoolein. In addition, we demonstrate that well-diffracting crystals of bR can be grown from a PE-based crystallization medium. Since most proteins lack a stability-indicating chromophore and other structure-based analytical techniques are poorly compatible with the lipid gel, we developed a generally-applicable spectroscopic technique based on the intrinsic fluorescence of tryptophan residues. This fluorescence assay makes possible the rapid evaluation of lipid gels as media for the crystallization of membrane proteins.     

The Kv7.2/Kv7.3 heterotetramer assembles with a random subunit arrangement

Voltage-gated K(+) channels composed of Kv7.2 and Kv7.3 are the predominant contributors to the M-current, which plays a key role in controlling neuronal activity. Various lines of evidence have indicated that Kv7.2 and Kv7.3 form a heteromeric channel. However, the subunit stoichiometry and arrangement within this putative heteromer are so far unknown. Here, we have addressed this question using atomic force microscopy imaging of complexes between isolated Kv7.2/Kv7.3 channels and antibodies to epitope tags on the two subunits, Myc on Kv7.2 and HA on Kv7.3. Initially, tsA 201 cells were transiently transfected with equal amounts of cDNA for the two subunits. The heteromer was isolated through binding of either tag to immunoaffinity beads and then decorated with antibodies to the other tag. In both cases, the distribution of angles between pairs of bound antibodies had two peaks, at around 90° and around 180°, and in both cases the 90° peak was about double the size of the 180° peak. These results indicate that the Kv7.2/Kv7.3 heteromer generated by cells expressing approximately equal amounts of the two subunits assembles as a tetramer with a predominantly 2:2 subunit stoichiometry and with a random subunit arrangement. When the DNA ratio for the two subunits was varied, copurification experiments indicated that the subunit stoichiometry was variable and not fixed at 2:2. Hence, there are no constraints on either the subunit stoichiometry or the subunit arrangement.     

Cytosolic,Autocrine Alpha-1 Proteinase Inhibitor (A1PI) Inhibits Caspase-1 and Blocks IL-1β Dependent Cytokine Release in Monocytes

Rationale

Activation state-dependent secretion of alpha-1 proteinase inhibitor (A1PI) by monocytes and macrophages was first reported in 1985. Since then, monocytes and tissue macrophages have emerged as key sentinels of infection and tissue damage via activation of self-assembling pattern recognition receptors (inflammasomes), which trigger inflammation and cell death in a caspase-1 dependent process. These studies examine the relationship between A1PI expression in primary monocytes and monocytic cell lines, and inflammatory cytokine expression in response to inflammasome directed stimuli.

Methods

IL-1 β expression was examined in lung macrophages expressing wild type A1PI (A1PI-M) or disease-associated Z isoform A1PI (A1PI-Z). Inflammatory cytokine release was evaluated in THP-1 monocytic cells or THP-1 cells lacking the inflammasome adaptor ASC, transfected with expression vectors encoding A1PI-M or A1PI-Z. A1PI-M was localized within monocytes by immunoprecipitation in hypotonic cell fractions. Cell-free titration of A1PI-M was performed against recombinant active caspase-1 in vitro.

Results

IL-1 β expression was elevated in lung macrophages expressing A1PI-Z. Overexpression of A1PI-M in THP-1 monocytes reduced secretion of IL-1β and TNF-α. In contrast, overexpression of A1PI-Z enhanced IL-1β and TNF- α secretion in an ASC dependent manner. A1PI-Z-enhanced cytokine release was inhibited by a small molecule caspase-1 inhibitor but not by high levels of exogenous wtA1PI. Cytosolic localization of A1PI-M in monocytes was not diminished with microtubule-inhibiting agents. A1PI-M co-localized with caspase-1 in gel-filtered cytoplasmic THP-1 preparations, and was co-immunoprecipitated with caspase 1 from nigericin-stimulated THP-1 cell lysate. Plasma-derived A1PI inhibited recombinant caspase-1 mediated conversion of a peptide substrate in a dose dependent manner.

Conclusions

Our results suggest that monocyte/macrophage-expressed A1PI-M antagonizes IL-1β secretion possibly via caspase-1 inhibition, a function which disease-associated A1PI-Z may lack. Therapeutic approaches which limit inflammasome responses in patients with A1PI deficiency, in combination with A1PI augmentation, may provide additional respiratory tissue-sparing benefits.     

Computational design,structure refinement and molecular dynamics simulation of novel engineered serratiopeptidase analogs

Communicated by Ramaswamy H. Sarma     

An overview of Iranian mangrove ecosystems, northern part of the Persian Gulf and Oman Sea

Iranian mangrove forests occur between longitude 25°19′ and 27°84′, in the north part of the Persian Gulf and Oman Sea. In 2002, it was estimated that 93.37 km² of Iranian shorelines were covered with mangrove forests, with the largest area (67.5 km²) occurring between the Khamir Port and the northwest side of Qeshm Island, and the smallest area (0.01 km²) in the Bardestan estuary. Only two species of mangrove are found in the Persian Gulf: Avicennia marina from Avicenniaceae and Rhizophora macrunata from Rhizophoraceae. A. marina is the dominant specie in these forests whereas Rh. macrunata is found only in the Sirik region. Overexploitation of mangrove leaves and oil pollution are the main causes of mangrove destruction in this region.     

Isolation and detection of Leishmania species among naturally infected Rhombomis opimus, a reservoir host of zoonotic cutaneous leishmaniasis in Turkemen Sahara, North East of Iran

In Iran, three species of Leishmania have been incriminated as the causative agents of human leishmaniasis, Leishmania (L.) major, Leishmania tropica, and Leishmania infantum.Rhombomis opimus have been incriminated as a principal reservoirs of the parasitic protozoan Leishmania major, the causative agent of rural zoonotic cutaneous leishmaniasis (ZCL) in Iran. Rodents captured and examined to find Leishmania species using conventional methods including direct impression smear and microscopic observation inoculation samples to Balb/c and culture in NNN medium. Also molecular method was employed to detect Leishmania in rodents by amplifying a region of the ribosomal RNA amplicon of Leishmania (ITS1-5.8S rRNA–ITS2) using Nested PCR. Leshmania species were specified by DNA sequences. 36 (38.3%) of R. opimus were Leishmania positive using at least one conventional methods. Many more ITS-rDNA fragments were amplified from R. opimus but only 65 out of 74 PCR products contained enough DNA for direct sequencing or readable sequences. The PCR assays detected in Iranian R. opimus not only Leishmania major in 59 (79.7%) rodents but also Leishmania turanica in 6 (8.1%) rodents, another parasite of the great gerbil. These parasites were found in Turkemen Sahara, North East of Iran, in a focus of rural (ZCL). L. major and L. turanica in R. opimus firmly identified from Turkemen Sahara. Nine rodents with Leishmania infections unidentified which some were unreadable sequences, these could be mixed infections of L. major, L. turanica, Leishmania gerbillisensu lato and Leishmania close to L. gerbilli or a related species reported in sandflies previously from this location. The haplotypes of L. major and L. turanica were found to be identical to that of isolates of L. major and L. turanica from Iran and in GenBank elsewhere. R. opimus is probably the key reservoir in this ZCL focus because of its abundance and its infection rates with both L. major and L. turanica.