Detergent dissection of membrane proteins of Entamoeba histolytica and its effect on lymphokine release in in vitro.

Fifty-two amoebic liver abscess cases were assessed for the release of lymphokines (LMIF) using detergent dissected membrane proteins (DDMP) of axenic Entamoeba histolytica (NIH:200) obtained with sodium deoxycholate treatment. Lymphokines release by T lymphocytes in response to both DDMP and whole amoebic lysate (WAL) was tested by leukocyte migration inhibition test on blood samples from amoebic liver abscess cases. A significant increase was noted in the release of LMIF and 100% positivity was observed with DDMP compared to whole amoebic extract with a positivity of 73%. The difference between means of the above two with regards to release of LMIF was found to be highly significant (P less than 0.005). This shows the patients had high degree of leukocyte sensitization to surface antigens of E. histolytica compared to the whole amoebic lysate. These findings suggest that the antigens shed might have important role as a potent antigen in elicitation of CMI response in amoebic liver abscess cases.     

Survival of Helicoverpa armigera larvae on and Bt toxin expression in various parts of transgenic Bt cotton (Bollgard II) plants

There is no conclusive evidence that Helicoverpa spp. (Lepidoptera: Noctuidae) in Australia have evolved significant levels of resistance to Bollgard II^® cotton (which expresses two Bt toxin genes, cry1Ac and cry2Ab). However, there is evidence of surviving larvae on Bollgard II cotton in the field. The distribution and survival of early‐instar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae were examined on whole Bollgard II and non‐Bt cotton plants in greenhouse bioassays. The expression of Cry toxins in various parts of Bollgard II plants was compared to the survival of larvae in those locations. Only 1% of larvae survived after 6 days on greenhouse‐grown Bollgard II plants compared to 31% on non‐Bt cotton plants. Overall, and across all time intervals, more larvae survived on reproductive parts (squares, flowers, and bolls) than on vegetative parts (leaves, stems, and petioles) on Bollgard II plants. The concentration of Cry1Ac toxin did not differ between plant structures, whereas Cry2Ab toxin differed significantly, but there was no relationship between the level of expression and the location of larvae. This study provides no evidence that lower expression of Cry toxins in the reproductive parts of plants explains the survival of H. armigera larvae on Bollgard II cotton.     

Efficacy of a Cladosporium sp. fungus against Helicoverpa armigera (Lepidoptera: Noctuidae), other insect pests and beneficial insects of cotton

A strain of the fungus Cladosporium sp. (RM16) from an egg of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) was assessed as a potential biocontrol agent for this pest. Pathogenicity of the fungus was tested against H. armigera eggs and larvae, cotton aphids (Aphis gossypii Glover; Homoptera: Aphididae), and silverleaf whitefly type B (Bemisia tabaci Gennadius; Hemiptera: Aleyrodidae). The pathogenicity of the fungus to the predatory red and blue beetles (Dicranolaius bellulus Guérin-Méneville; Coleoptera: Melyridae), transverse ladybird beetles (Coccinella transversalis Fabricius; Coleoptera: Coccinellidae), green lacewings (Mallada signatus Schneider; Neuroptera: Chrysopidae) and damsel bugs (Nabis kinbergii Reuter; Hemiptera: Nabidae), was also assessed in the laboratory. Fungus treatment resulted in failure to hatch of up to 64% of H. armigera eggs (compared with 11% in the controls) and mortality of 54% of first instar H. armigera larvae (compared with 5% in the controls). In contrast, it was not pathogenic to later instar H. armigera larvae. Cladosporium RM16 was also efficacious against the sap-sucking insect pests of cotton that were tested. No significant harmful effect of the fungus was found on any of the four beneficial predatory insects assessed in this study. Cladosporium RM16 has the potential as biological control agent to support integrated pest management in cotton farming systems, although this needs intensive study.     

Effect of ultraviolet B (302 nm) irradiation on viability, metabolic and detoxification functions of goat hepatocytes – in vitro study

The object of the present study was to investigate the effect(s) of UV-B irradiation on the functional integrity, metabolic and detoxifying capacity of the isolated goat hepatocytes. Isolated goat hepatocytes were subjected to UV-B irradiation invitro for 0, 250, 500, 1250, 2500 and 7500 Joules/m² which correspond to the irradiation time of 0, 1, 2, 5, 10 and 30 min. Cells were then analysed for Viability (Trypan blue exclusion test [TBE], 3-[4,5-dimethylthiozol-2yl]-2,5-diphenyltetrazolium bromide [MTT] assay, Membrane integrity (Lactate dehydrogenase [LDH] leakage, Lipid peroxidation) Detoxification (Ureagenesis, Cytochrome P450 activity [CYP450, Diazepam metabolism] and Glutathione-S-Transferase [GST] activity. The results show that there was no difference in functional, metabolic as well as detoxifying parameters of the hepatocytes when irradiated from 0–1250 Joules/m², whereas a significant alteration was appreciable in the parameters such as LDH leakage, lipid peroxidation, and CYP450 activity when irradiated beyond 1250 Joules/m². Our present findings suggest that the biologically compatible and feasible dose of UV-B irradiation for xenotransplantation appears to be 1250 Joules/m².     

Discovery of novel antitubercular 1,5-dimethyl-2-phenyl-4-([5-(arylamino)-1,3,4-oxadiazol-2-yl]methylamino)-1,2-dihydro-3H-pyrazol-3-one analogues

In search of potential therapeutics for tuberculosis, we describe herewith the synthesis, characterization and antimycobacterial activity of 1,5-dimethyl-2-phenyl-4-([5-(arylamino)-1,3,4-oxadiazol-2-yl]methylamino)-1,2-dihydro-3H-pyrazol-3-one analogues. Among the synthesized compounds, 4-[(5-[(4-fluorophenylamino]-1,3,4-oxadiazol-2-yl)methylamino]-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (4a) was found to be the most promising compound active against Mycobacterium tuberculosis H(37)Rv and isoniazid resistant M. tuberculosis with minimum inhibitory concentrations, 0.78 and 3.12μg/mL, respectively, free from any cytotoxicity (>62.5μg/mL).     

POMA analyses as new efficient bioinformatics’ platform to predict and optimise bioactivity of synthesized 3a,4-dihydro-3H-indeno[1,2-c]pyrazole-2-carboxamide/carbothioamide analogues

A series of 43, 3a,4-dihydro-3H-indeno[1,2-c]pyrazole-2-carboxamide/carbothioamide analogues (D01–D43) were analysed using Petra, Osiris, Molinspiration and ALOGPS (POMA) to identify pharmacophore, toxicity prediction, lipophilicity and bioactivity. All the compounds were evaluated for anti-HIV activity. 3-(4-Chlorophenyl)-N-(4-fluorophenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]pyrazole-2-carboxamide (D07) was found to be the most active with IC₅₀ > 4.83 μM and CC₅₀ 4.83 μM. 3-(4-Fluorophenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]pyrazole-2-carbothioamide (D41) was found to be the most active compound against bacterial strains with MIC of 4 μg/ml, comparable to the standard drug ciprofloxacin while 3-(4-methoxyphenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]pyrazole-2-carboxamide (D38) was found to be the most active compound against fungal strains with MIC 2–4 μg/ml, however less active than standard fluconazole. Toxicities prediction by Osiris were well supported and experimentally verified with exception of some compounds. In anticonvulsant screening, 3-(4-fluorophenyl)-N-(4-chlorophenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]pyrazole-2-carboxamide (D09) showed maximum activity showing 100% (4/4, 0.25–0.5 h) and 75% (3/4, 1.0 h) protection against minimal clonic seizure test without any toxicity.     

Patterns of Allelic Diversity in Spring Wheat Populations by SSR-Markers

Precise assessment of diversity in available breeding germplasm helps to preempt epidemics and abrupt environmental changes. Spring wheat germplasm consisting of 84 accessions including cultivars, breeding lines and landraces from various origins was scanned with 44 SSRs. For allele frequencies, allelic patterns, heterozygosity and polymorphism the selected population was divided in three subpopulations: (i) pre-green revolution (pre-1965), (ii) post-green revolution (post-1965), (iii) post-veery (post-2000). Alleles produced in pre-1965, post-1965 and post-2000 subpopulations were 115, 144 and 131, respectively. Mean PIC values for pre-1965, post-1965 and post-2000 subpopulations were 0.48, 0.52 and 051, respectively. Allelic patterns showed no locally common alleles in any of the subpopulation. The pre-1965 subpopulation had also no private allele, however, average number of private alleles decreased from post-1965 to post-2000 subpopulation. In case of effective alleles and Shannon’s information index trend was increasing from pre-1965 to post-1965 and then decreasing from post-1965 to post-2000. The decreasing trend alarms the reduced genetic diversity in wheat varieties developed after 2000. PCA and cluster analysis didn’t clearly differentiated subpopulations, though pre-1965 genotypes showed higher genetic distance from post-1965 and post-2000 subpopulations. The decreasing measures of genetic diversity in post-2000 wheat genotypes should be a concern for wheat breeders, therefore, all sources of broadening genetic diversity should be exploited.     

Thermal Tolerance Limits of Diamondback Moth in Ramping and Plunging Assays

Thermal sensitivity is a crucial determinant of insect abundance and distribution. The way it is measured can have a critical influence on the conclusions made. Diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is an important insect pest of cruciferous crops around the world and the thermal responses of polyphagous species are critical to understand the influences of a rapidly changing climate on their distribution and abundance. Experiments were carried out to the lethal temperature limits (ULT₀ and LLT₀: temperatures where there is no survival) as well as Upper and Lower Lethal Temperature (ULT₂₅ and LLT₂₅) (temperature where 25% DBM survived) of lab-reared adult DBM population to extreme temperatures attained by either two-way ramping (ramping temperatures from baseline to LT₂₅ and ramping back again) or sudden plunging method. In this study the ULT₀ for DBM was recorded as 42.6°C and LLT₀ was recorded as −16.5°C. DBM had an ULT₂₅ of 41.8°C and LLT₂₅ of −15.2°C. The duration of exposure to extreme temperatures had significant impacts on survival of DBM, with extreme temperatures and/or longer durations contributing to higher lethality. Comparing the two-way ramping temperature treatment to that of direct plunging temperature treatment, our study clearly demonstrated that DBM was more tolerant to temperature in the two-way ramping assay than that of the plunging assay for cold temperatures, but at warmer temperatures survival exhibited no differences between ramping and plunging. These results suggest that DBM will not be put under physiological stress from a rapidly changing climate, rather access to host plants in marginal habitats has enabled them to expand their distribution. Two-way temperature ramping enhances survival of DBM at cold temperatures, and this needs to be examined across a range of taxa and life stages to determine if enhanced survival is widespread incorporating a ramping recovery method.