Toxicity, antifeedant and physiological effects of trans-anethole against Hyphantria cunea Drury (Lep: Arctiidae)

Plant secondary metabolites are currently known to interfere with basic metabolic, behavioral and physiological processes of insects. In the current study, the biological and physiological effects of trans-anethole were investigated against Hyphantria cunea Drury. The bioassay data demonstrated the high toxicity of trans-anethole against the fourth-instar larvae with the LC₃₀, LC₅₀ and LC₉₀ values of 0.72, 1.41 and 7.20 μL/mL, respectively. Also the concentrations of LC₃₀ and LC₅₀ showed 53 and 87% feeding deterrency against the larvae. The biochemical experiments revealed that oral exposure of trans-anethole decreased the activities of digestive enzymes, acetylcholinesterase and the contents of energy reserves while, it induced the activities of detoxifying and antioxidant enzymes compared to control. In fact, trans-anethole induced the inhibition of digestion and AChE activities accompanied by imbalance in metabolic and oxidative processes so it may be recommended as a potent biopesticide in control of H. cunea populations.

Immunological interactions of Chilo suppressalis Walker (Lepidoptera: Crambidae) with the native entomopathogenic fungi

Entomopathogenic fungi can attack many insect hosts and have been applied as the eco-friendly alternatives to synthetic chemicals for the control of pests. Insects have developed different defense systems encountering entomopathogens including humoral and cellular immune responses. In the present study, injection of some native entomopathogenic fungi to the Chilo suppressalis Walker larvae resulted in an enhancement of the cellular and antimicrobial defenses. The numbers of total and differential hemocytes increased rapidly in the first 3 and 6 h but those gradually reduced 12 and 24 h post-injections. The nodule formation and phenoloxidase activity increased at the time intervals after fungal infection. A similar trend was found in the transcription of antimicrobial peptides including attacin1 and 2, cecropin1 and 2, gallerimycin, defensin, lysozyme, and prophenoloxidase-activating proteinase-3 during infection fungi. In all cases, the target gene transcription was upper in the larvae injected by the fungi than that of control larvae. These results may elucidate better knowledge on the interaction of the fungi present in agroecosystems with the target insect pest.

Biological control of rice sheath blight disease with formulation of indigenous Trichoderma strains under paddy field conditions

The effectiveness of indigenous Trichoderma strains in preventing sheath blight disease was evaluated during two growing seasons under paddy field conditions. Broom sorghum seeds were used for mass production of Trichoderma strains. Colonized seeds were ground to powder and mixed with talc and carboxymethyl cellulose. Suspensions were made from the bioformulations and sprayed onto rice plants. Effects of Trichoderma strains on disease incidence and severity as well as yield and other growth parameters were determined and compared with a chemical fungicide and a commercial biofungicide. A combined analysis of variance across two years was performed and a statistically significant effect of year, treatment and their interaction was reported. Results indicate that environmental factors and different biological fungicides had a strong effect on disease development under natural conditions. According to the results, propiconazole and T. harzianum AS12-2 resulted in the least disease severity and incidence. Overall, the efficacy of T. harzianum AS12-2 in reducing sheath blight development was significantly better than other Trichoderma treatments and was comparable to the conventional fungicide.

A Laboratory Study on the Modeling of Temperature-Dependent Development and Antioxidant System of Chilo suppressalis (Lepidoptera: Crambidae)

The developmental rates of Chilo suppressalis (Walker; Lepidoptera: Crambidae) were investigated at different constant temperatures of 11, 18, 22, 24, 26, 30, 32, 34, and 36°C to find out temperature thresholds, thermal requirements and larval antioxidant responses. The time to complete immature stages separately reduced by raising the rearing temperature except for eggs which showed no significant differences at 30-34°C. Data analysis by traditional and Ikemoto-Takai linear models determined Tmin of 10.0 and 9.92°C as well as thermal constants of 840.34 and 848.0 DD for the overall immature stages. The models including Analytis, Briere-2, Lactin-2, and Sharpe-Schoolfield-Ikemoto (SSI) calculated Tmin values of 9.15, 9.57, 10.0, and 11.37°C for overall immature stages while Tfast was found to be 33.8, 33.3, 33.7, and 33.0°C, respectively. Tmax was calculated as 35.12, 34.66, 34.56, 36.84, 34.11, and 35.15°C for Analytis, Briere-2, Lactin-2, SSI, Logan-6, and Logan-10. Topt using SSI was calculated as 24.42°C for total developmental time. The larvae exposure to 34°C in the short-term period demonstrated the highest activities of catalase, peroxidase, and superoxide dismutase compared to control (24°C). Activities of ascorbate peroxidase and glucose-6-phosphate hydrogenase also increased at 34°C in the short-term period for all preparations. The larvae exposed to 34°C in short-term period showed the highest amounts of Malondialdehyde and oxidized and reduced thiols (RSSR/RSH) ratio compared to control. These results may be useful to explain potentially ecological performance of C. suppressalis as the major pest of rice in Iran.

The incidence of hepatitis C virus infection among opiate drug users in Mamoura hospital patient in Alexandria, Egypt

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Introduction

Egypt is one of the most famous endemic areas for hepatitis C virus. Drug use in Egypt is rising exponentially. Drug use is always considered one of the main risk factors for HCV.

Objectives

To assess the effect the route of drug use on the incidence of HCV in the Egyptian population.

Aim

To study the effects of opiates (tramadol and heroin) use and the route of intake on the incidence of HCV infection among addicts treated in Mamoura mental state hospital, Alexandria, Egypt.

Methods

This is a cross-sectional study on drug dependence patients visiting the out patient clinic for addiction in Elmamora Hospital.

Subjects were divided into two groups.

Group I: Control group.

Twenty non-addict volunteers.

Group II: Cases groups (comprising 60 subjects)

This group will be divided into three sub-groups each contains 20 cases.

Group IIa: consuming tramadol.

Group IIb: consuming tramadol and heroin by injection.

Group IIc: consuming tramadol and heroin by inhalation.

All studied groups were subjected to:.

1. detailed history taking, urine screening tests for drugs of abuse, liver functions tests and HCV screening.

Results

The study showed deterioration in liver function tests in the heroin and tramadol use groups compared to the tramadol only use.

There was a statistical significant difference in the incidence of HCV infection in the heroin injection group (85%) compared to 35% in the heroin non injector users and only 5% in tramadol users had HCV positive.

Conclusion

Heroin injection showed the highest risk for both liver function deterioration and HCV infection.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Immune and metabolic responses of Chilo suppressalis Walker (Lepidoptera: Crambidae) larvae to an insect growth regulator, hexaflumuron

Efficient control of Chilo suppressalis Walker is always controversial due to highly economic damage, resistance to insecticides and environmental pollutions. So, combination of safe pest controls e.g. biocontrol agents and insect growth regulators seems to be promising via integrated pest management program. Bioassay of hexaflumuron on 4th larval instars revealed concentrations of 44.34, 179.74 and 474.94µg/ml as LC10-50 values. Numbers of total hemocytes, plasmatocytes and granulocytes as well as phenoloxidase activity increased in the different time intervals following treatment by hexaflumuron. Combined effects of hexaflumuron and Beauveria bassiana Vuillemin also increased hemocyte numbers and phenoloxidase activity at different time intervals using all concentrations. Activities of general esterases assayed by α- and β-naphtyl acetate and glutathione S-transferase using CDNB and DCNB increased 1-12h post-treatment. Activities of aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase and aldolase increased in the larvae treated by hexaflumuron. However enhanced activity of lactate dehydrogenase was only obtained by treating 180 and 470µg/ml concentrations of hexaflumuron. Activities of ACP and ALP were found to be higher than control for all time intervals even 1-12h post-treatment. The amounts of HDL and LDL increased in the highest concentrations of hexaflumuron after 12-24h of post-treatment. Amount of triglyceride was higher than that of control after 1 and 3h but it was lower in other time intervals. Amounts of glycogen and protein were lower than those of control for all time intervals except for 6 and 12h of post-treatment in case of protein. Results of the current study revealed negative effects of hexaflumuron on intermediary metabolism of Chilo suppressalis but it increased the number of hemocytes and activity of phenoloxidase which are responsible for spore removal from hemolymph. It can be concluded that hexaflumuron is able to decrease survival and biological performance of C. suppressalis via intervening in intermediary metabolism but the given results showed incompatibility of the IGR with possible microbial control.

Purification and characterization of midgut α-amylase in a predatory bug, Andralus spinidens

α-Amylases are widespread enzymes that catalyze endohydrolysis of long α-1,4-glucan chains such as starch and glycogen. The highest amylolytic activity was found in 5th instar nymphs and midgut of the predatory bug, Andrallus spinidens F. (Hemiptera: Pentatomidae). The α-amylase was purified following a three-step procedure. The purified α-amylase had a specific activity of 13.46 U/mg protein, recovery of 4.21, purification fold of 13.87, and molecular weight of 21.3 kDa. The enzyme had optimal pH and temperature of 7 and 45°C, respectively. Na+, Mn+, Mg2+, and Zn2+ significantly decreased activity of the purified α-amylase, but some concentrations of K+, Ca2+, and Cu2+ had the opposite effect. EDTA, EGTA, and DTC significantly decreased enzymatic activity, showing the presence of metal ions in the catalytic site of the enzyme. Kinetic parameters of the purified α-amylase showed a Km of 3.71% in starch and 4.96% for glycogen, suggesting that the enzyme had a higher affinity for starch.

Role of proteases in extra-oral digestion of a predatory bug, Andrallus spinidens

Roles of salivary proteases in the extra-oral digestion of the predatory bug, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae) were studied by using 2% azocasein as a general substrate and specific protease substrates, as well as synthetic and endogenous inhibitors. It was found that salivary glands of A. spinidens have two anterior, two lateral, and two posterior lobes. Azocasein was used to measure the activity of general proteases in the salivary glands using different buffer solutions. The enzyme had the highest activity at pH 8. General protease activity was highest at 40 °C and was stable for 6-16 hours. The use of specific substrates showed that trypsin-like, chymotrypsin-like, aminopeptidase, and carboxypeptidase are the active proteases present in salivary glands, by the maximum activity of trypsin-like protease in addition to their optimal pH between 8-9. Ca(2+) and Mg(2+) increased proteolytic activity about 216%, while other ions decreased it. Specific inhibitors including SBTI, PMSF, TLCK, and TPCK significantly decreased enzyme activity, as well as the specific inhibitors of methalloproteases including phenanthroline, EGTA, and TTHA. Extracted endogenous trypsin inhibitors extracted from potential prey, Chilo suppressalis, Naranga aenescens, Pieris brassicae, Hyphantria cunea, and Ephestia kuhniella, had different effects on trypsin-like protease activity of A. spinidens salivary glands. With the exception of C. suppressalis, the endogenous inhibitors significantly decreased enzyme activity in A. spinidens.

Dissociable components of rule-guided behavior depend on distinct medial and prefrontal regions

Much of our behavior is guided by rules. Although human prefrontal cortex (PFC) and anterior cingulate cortex (ACC) are implicated in implementing rule-guided behavior, the crucial contributions made by different regions within these areas are not yet specified. In an attempt to bridge human neuropsychology and nonhuman primate neurophysiology, we report the effects of circumscribed lesions to macaque orbitofrontal cortex (OFC), principal sulcus (PS), superior dorsolateral PFC, ventrolateral PFC, or ACC sulcus, on separable cognitive components of a Wisconsin Card Sorting Test (WCST) analog. Only the PS lesions impaired maintenance of abstract rules in working memory; only the OFC lesions impaired rapid reward-based updating of representations of rule value; the ACC sulcus lesions impaired active reference to the value of recent choice-outcomes during rule-based decision-making.