Eleni Vasara

Biological Control of Bactocera oleae (Diptera: Tephritidae) Using a Greek Bacillus thuringiensis Isolate

Abstract Bacillus thuringiensis, isolate 114A, was used intoxicity experiments against the wild population of the olive pestBactrocera oleae (Gmelin). In laboratory experiments, sporesand crystals of the B.t. were delivered to the insects withthe food. Longevity, oviposition period, number of eggs produced, andpercent hatch were recorded. Olive fruits from the oviposition testwere dipped into a suspension containing spores and crystals ofB. thuringiensis 114A after the eggs were deposited. Infield experiments, four to six sprayings per year of B.t.114A isolate were applied for three successive years. It was foundthat, in addition to the longevity of B. oleae, theoviposition period, number of eggs and percent egg hatch decreased.Also, the percentage of pupation and emergence was reduced when olivefruits with eggs in their mesocarp were dipped in the solution ofspores and crystals. Field applications with the toxins of 114A isolateof B. thuringiensis have resulted in significant protectionof the olive production.

Myocardial adenosine does not correlate with the protection mediated by ischaemic or pharmacological preconditioning in rat heart

1. We tested the hypothesis that ischaemic preconditioning of the rat heart activates cardiovascular adenosine formation to provide enhanced cardioprotection.

Activation of α1-adrenoceptors is not essential for the mediation of ischaemic preconditioning in rat heart

1. The aim of the present study was to clarify the role of α1‐adrenoceptors in the mechanism of ischaemic preconditioning (IP).

Correlation of the Insecticidal Activity of the Bacillus thuringiensis A4 Strain Against Bactrocera oleae (Diptera) with the 140-kDa Crystal Polypeptide

The crystals of the soil-isolated Bacillus thuringiensis (Bt) strain A4 consist of two polypeptides with molecular mass of 140 kDa and 32 kDa that exhibit insecticidal activity against adult flies of Bactrocera oleae (Diptera). Plasmid curing applied to this strain resulted in the isolation of several subclones exhibiting alterations in their crystal polypeptides as well as two acrystalliferous subclones. The crystals of subclone 1.1 lacked the 32-kDa polypeptide and consisted uniquely of a 140-kDa polypeptide antigenically related to the parental 140-kDa crystal polypeptide. Additionally, the crystals of this subclone exhibited insecticidal activity against B. oleae equivalent to that of the parental strain. Therefore, the 32-kDa crystal polypeptide is dispensable for insecticidal activity, which appears to be dependent on the presence of the 140-kDa crystal polypeptide.

Effect of municipal waste water effluent upon the expression of Glutathione S-transferase isoenzymes of brine shrimp Artemia

Multiple isoenzymes of the detoxification enzyme family Glutathione S-transferase are expressed in the brine shrimp Artemia. The number of the major ones detected in crude extract by means of chromatofocusing varied between three and four, depending on the age. Two isoenzymes, one alkaline and one neutral (with corresponding isoelectric points of 8.5 and 7.2) appear to be dominant in all three developmental stages studied, (24, 48, and 72 h after hatching). Culturing Artemia for 48 h after hatching, in artificial sea water prepared by municipal wastewater effluent resulted to significant alterations of the isoenzyme profile. In comparison to organisms cultured for the same period of time in artificial sea water prepared by filtered tap water, the expression of the alkaline isoenzyme decreased by 62% while that of the neutral isoenzyme increased by 58%. Furthermore, the enzyme activity of the major isoenzyme of the acidic area increased by more than two folds. It is worth mentioning that although the specific activity of the total enzyme in the whole body homogenate was elevated, no statistically significant alteration of the Km value was observed. These findings suggest that study of the isoenzyme profile of Glutathione S-transferase may offer high sensitivity in detecting environmental pollution and needs to be further investigated.

Sodium and potassium intake in healthy adults in Thessaloniki Greater Metropolitan Area—the salt intake in Northern Greece (SING) Study.

A reduction in population sodium (as salt) consumption is a global health priority, as well as one of the most cost-effective strategies to reduce the burden of cardiovascular disease. High potassium intake is also recommended to reduce cardiovascular disease. To establish effective policies for setting targets and monitoring effectiveness within each country, the current level of consumption should be known. Greece lacks data on actual sodium and potassium intake. The aim of the present study was therefore to assess dietary salt (using sodium as biomarker) and potassium intakes in a sample of healthy adults in northern Greece, and to determine whether adherence to a Mediterranean diet is related to different sodium intakes or sodium-to-potassium ratio. A cross-sectional survey was carried out in the Thessaloniki greater metropolitan area (northern Greece) (n = 252, aged 18–75 years, 45.2% males). Participants’ dietary sodium and potassium intakes were determined by 24-hour urinary sodium and potassium excretions. In addition, we estimated their adherence to Mediterranean diet by the use of an 11-item MedDietScore (range 0–55). The mean sodium excretion was 175 (SD 72) mmol/day, equivalent to 4220 (1745) mg of sodium or 10.7 (4.4) g of salt per day, and the potassium excretion was 65 (25) mmol/day, equivalent to 3303 (1247) mg per day. Men had higher sodium and potassium excretions compared to women. Only 5.6% of the sample had salt intake <5 g/day, which is the target intake recommended by the World Health Organization. Mean sodium-to-potassium excretion ratio was 2.82 (1.07). There was no significant difference in salt or potassium intake or their ratio across MedDietScore quartiles. No significant relationships were found between salt intake and adherence to a Mediterranean diet, suggesting that the perception of the health benefits of the Mediterranean diet does not hold when referring to salt consumption. These results suggest the need for a larger, nation-wide survey on salt intake in Greece and underline the importance of continuation of salt reduction initiatives in Greece.

Seasonal variations of cellular stress response in the heart and gastrocnemius muscle of the water frog (Pelophylax ridibundus)

The present study aimed to investigate the seasonal cellular stress response in the heart and the gastrocnemius muscle of the amphibian Pelophylax ridibundus (former name Rana ridibunda) during an 8 month acclimatization period in the field. Processes studied included heat shock protein expression and protein kinase activation. The cellular stress response was addressed through the expression of Hsp70 and Hsp90 and the phosphorylation of stress-activated protein kinases and particularly p38 mitogen-activated protein kinase (p38 MAPK), the extracellular signal-regulated kinases (ERK-1/2) and c-Jun N-terminal kinases (JNK1/2/3). Due to a general metabolic depression during winter hibernation, the induction of Hsp70 and Hsp90 and the phosphorylation of p38 MAPK, JNKs and ERKs are retained at low levels of expression in the examined tissues of P. ridibundus. Recovery from hibernation induces increased levels of the specific proteins, probably providing stamina to the animals during their arousal.