scholarly journals In Vitro Effects of Pesticides on European Foulbrood in Honeybee Larvae

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 252
Author(s):  
Sarah C. Wood ◽  
Jocelyne C. Chalifour ◽  
Ivanna V. Kozii ◽  
Igor Medici de Mattos ◽  
Colby D. Klein ◽  
...  

Neonicotinoid and fungicide exposure has been linked to immunosuppression and increased susceptibility to disease in honeybees (Apis mellifera). European foulbrood, caused by the bacterium Melissococcus plutonius, is a disease of honeybee larvae which causes economic hardship for commercial beekeepers, in particular those whose colonies pollinate blueberries. We report for the first time in Canada, an atypical variant of M. plutonius isolated from a blueberry-pollinating colony. With this isolate, we used an in vitro larval infection system to study the effects of pesticide exposure on the development of European foulbrood disease. Pesticide doses tested were excessive (thiamethoxam and pyrimethanil) or maximal field-relevant (propiconazole and boscalid). We found that chronic exposure to the combination of thiamethoxam and propiconazole significantly decreased the survival of larvae infected with M. plutonius, while larvae chronically exposed to thiamethoxam and/or boscalid or pyrimethanil did not experience significant increases in mortality from M. plutonius infection in vitro. Based on these results, individual, calculated field-realistic residues of thiamethoxam and/or boscalid or pyrimethanil are unlikely to increase mortality from European foulbrood disease in honeybee worker brood, while the effects of field-relevant exposure to thiamethoxam and propiconazole on larval mortality from European foulbrood warrant further study.

2020 ◽  
Vol 27 (9) ◽  
pp. 888-894
Author(s):  
Havva Aybek ◽  
Yusuf Temel ◽  
Barzan Mirza Ahmed ◽  
Can Ali Ağca ◽  
Mehmet Çiftci

Background: Cancer is the disease that causes the most death after cardiovascular diseases all over the world these days. Breast cancer is the most common type of cancer among women and ranks the second among cancer-related deaths after lung cancer. Chemotherapeutics act by killing cancer cells, preventing their spread and slowing their growth. Recent studies focus on the effects of chemotherapeutics on cancer cells and new chemotherapy approaches that targeting enzymes that catalyze important metabolic reactions in the cell. Objective: The aim of this study was to investigate the effects of chemotherapeutic agents, Tamoxifen and 5-FU, on MCF-7 cell line and human erythrocyte GST, an important enzyme of intracellular antioxidant metabolism. Methods: In this study, it was investigated that the effect of chemotherapeutic agents, Tamoxifen and 5-FU, on MCF-7 breast cancer cell line and performed ROS analyzes. In addition, it was purified glutathione S-transferase (GST), one of the important enzymes of intracellular antioxidant mechanism, from human erythrocytes by using ammonium sulfate precipitation and glutathione agarose affinity chromatography, and investigated in vitro effects of chemotherapeutic agents, 5 - FU and Tamoxifen, on the activity of this enzyme for the first time. Results: it was determined that Tamoxifen and 5-FU inhibited cellular viability and 5-FU increased intracellular levels of ROS, whereas Tamoxifen reduced intracellular levels of ROS. In addition, human erythrocyte GST enzyme with 16.2 EU/mg specific activity was purified 265.97-fold with a yield of 35% using ammonium sulfate precipitation and glutathione agarose affinity chromatography. The purity of the enzyme was checked by the SDS-PAGE method. In vitro effects of chemotherapeutics, 5-FU and Tamoxifen, on GST activity purified from human erythrocytes were investigated. The results showed that 5-FU increased the activity of GST in the concentration range of 77 to 1155 μM and that Tamoxifen increased the activity of GST in the concentration range of 0.54 to 2.70 μM. Conclusion: In this study, the effects of tamoxifen and 5-FU chemotherapeutic agents on both MCF-7 cell line and human GST enzyme were examined together for the first time. Our study showed that chemotherapeutic agents (5-FU and Tamoxifen) inhibited cellular viability and Tamoxifen reduced intracellular levels of ROS whereas 5-FU increased intracellular levels of ROS. In addition, 5-FU and Tamoxifen were found to increase the activity of GST enzyme purified from the human erythrocyte.


Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Andrea Wade ◽  
Chia-Hua Lin ◽  
Colin Kurkul ◽  
Erzsébet Ravasz Regan ◽  
Reed M. Johnson

Beekeepers providing pollination services for California almond orchards have reported observing dead or malformed brood during and immediately after almond bloom—effects that they attribute to pesticide exposure. The objective of this study was to test commonly used insecticides and fungicides during almond bloom on honey bee larval development in a laboratory bioassay. In vitro rearing of worker honey bee larvae was performed to test the effect of three insecticides (chlorantraniliprole, diflubenzuron, and methoxyfenozide) and three fungicides (propiconazole, iprodione, and a mixture of boscalid-pyraclostrobin), applied alone or in insecticide-fungicide combinations, on larval development. Young worker larvae were fed diets contaminated with active ingredients at concentration ratios simulating a tank-mix at the maximum label rate. Overall, larvae receiving insecticide and insecticide-fungicide combinations were less likely to survive to adulthood when compared to the control or fungicide-only treatments. The insecticide chlorantraniliprole increased larval mortality when combined with the fungicides propiconazole or iprodione, but not alone; the chlorantraniliprole-propiconazole combination was also found to be highly toxic to adult workers treated topically. Diflubenzuron generally increased larval mortality, but no synergistic effect was observed when combined with fungicides. Neither methoxyfenozide nor any methoxyfenozide-fungicide combination increased mortality. Exposure to insecticides applied during almond bloom has the potential to harm honey bees and this effect may, in certain instances, be more damaging when insecticides are applied in combination with fungicides.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  

1990 ◽  
Vol 64 (03) ◽  
pp. 402-406 ◽  
Author(s):  
M D Oethinger ◽  
E Seifried

SummaryThe present in vitro study investigated dose-, time- and temperature-dependent effects of two-chain urokinase plasminogen activato(u-PA, urokinase) on normal citrated plasma. When 10 μg/ml u-PA wereadded to pooled normal plasma and incubated for 30 min at an ambient temperature (25° C), α2-antiplas-min decreased to 8% of the control value. Incubation on ice yielded a decrease to 45% of control,whereas α2-antiplasmin was fully consumed at 37° C. Fibrinogen and plasminogen fell to 46% and 39%, respectively, after a 30 min incubation at 25° C. Thrombin time prolonged to 190% of control.Various inhibitors were studied with respect to their suitability and efficacy to prevent these in vitro effects. Aprotinin exhibited a good protective effect on fibrinogen at concentrations exceeding 500 KlU/ml plasma. Its use, however, was limited due to interferences with some haemostatic assays. We could demonstrate that L-Glutamyl-L-Glycyl-L-Arginyl chloromethyl ketone (GGACK) and a specific polyclonal anti-u-PA-antibody (anti-u-PA-IgG) effectively inhibited urokinase-induced plasmin generation without interfering with haemostatic assays. The anti-u-PA-antibody afforded full protection ofα2-antiplasmin at therapeutic levels of u-PA.It is concluded that u-PA in plasma samples from patients during thrombolytic therapy may induce in vitro effects which should be prevented by the use of a suitable inhibitor such as GGACK or specific anti-u-PA-antibody.


1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.


1987 ◽  
Vol 58 (03) ◽  
pp. 921-926 ◽  
Author(s):  
E Seifried ◽  
P Tanswell

SummaryIn vitro, concentration-dependent effects of rt-PA on a range of coagulation and fibrinolytic assays in thawed plasma samples were investigated. In absence of a fibrinolytic inhibitor, 2 μg rt-PA/ml blood (3.4 μg/ml plasma) caused prolongation of clotting time assays and decreases of plasminogen (to 44% of the control value), fibrinogen (to 27%), α2-antiplasmin (to 5%), FV (to 67%), FVIII (to 41%) and FXIII (to 16%).Of three inhibitors tested, a specific polyclonal anti-rt-PA antibody prevented interferences in all fibrinolytic and most clotting assays. D-Phe-Pro-Arg-CH2Cl (PPACK) enabled correct assays of fibrinogen and fibrinolytic parameters but interfered with coagulometric assays dependent on endogenous thrombin generation. Aprotinin was suitable only for a restricted range of both assay types.Most in vitro effects were observed only with rt-PA plasma concentrations in excess of therapeutic values. Nevertheless it is concluded that for clinical application, collection of blood samples on either specific antibody or PPACK is essential for a correct assessment of in vivo effects of rt-PA on the haemostatic system in patients undergoing fibrinolytic therapy.


1963 ◽  
Vol 09 (01) ◽  
pp. 164-174 ◽  
Author(s):  
Albert R Pappenhagen ◽  
J. L Koppel ◽  
John H Olwin

SummaryData have been presented on the in vitro effects of human chylomicra, low-density human plasma lipoproteins, and partially purified preparations of various phospholipids on human plasma euglobulin lysis. Euglobulin lysis was found to be accelerated by preparations of mixed soybean phospholipids (aso-lectin), cephalin, phosphatidyl inositol, phophatidyl serine and phosphatidyl ethanolamine. In contrast, it was found to be inhibited by preparations of human chylomicra, low-density human plasma liproproteins and lecithin. Inhibition of euglobulin lysis produced by any of these three agents could be diminished or completely overcome by the simultaneous presence of suitable levels of any one of the accelerating agents. In all cases studied, both inhibitory and accelerating effects were observed to be concentration-dependent. Evidence has been obtained to suggest that in the case of the accelerating agents the observed increased rate of euglobulin lysis is not a direct effect on lysis itself, but rather is due to more complete precipitation of plasminogen in the presence of these substances. On the other hand, it appears that the inhibitory effects observed are not related to the extent of plasminogen precipitation, but are actually true inhibitions of euglobulin lysis. The possible clinical significance of some of these observations has been briefly discussed.


2007 ◽  
Vol 55 (S 1) ◽  
Author(s):  
SA Mohamed ◽  
M Misfeld ◽  
T Hanke ◽  
W Kuehnel ◽  
HH Sievers

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)


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