Honeybees Produce Millimolar Concentrations of Non-Neuronal Acetylcholine for Breeding: Possible Adverse Effects of Neonicotinoids.

The worldwide use of neonicotinoid pesticides has caused concern on account of their involvement in the decline of bee populations, which are key pollinators in most ecosystems. Here we describe a role of non-neuronal acetylcholine (ACh) for breeding of Apis mellifera carnica and a so far unknown effect of neonicotinoids on non-target insects. Royal jelly or larval food are produced by the hypopharyngeal gland of nursing bees and contain unusually high ACh concentrations (4-8 mM). ACh is extremely well conserved in royal jelly or brood food because of the acidic pH of 4.0. This condition protects ACh from degradation thus ensuring delivery of intact ACh to larvae. Raising the pH to ≥5.5 and applying cholinesterase reduced the content of ACh substantially (by 75-90%) in larval food. When this manipulated brood was tested in artificial larval breeding experiments, the survival rate was higher with food supplemented by 100% with ACh (6 mM) than with food not supplemented with ACh. ACh release from the hypopharyngeal gland and its content in brood food declined by 80%, when honeybee colonies were exposed for 4 weeks to high concentrations of the neonicotinoids clothianidin (100 parts per billion [ppb]) or thiacloprid (8,800 ppb). Under these conditions the secretory cells of the gland were markedly damaged and brood development was severely compromised. Even field-relevant low concentrations of thiacloprid (200 ppb) or clothianidin (1 and 10 ppb) reduced ACh level in the brood food and showed initial adverse effects on brood development. Our findings indicate a hitherto unknown target of neonicotinoids to induce adverse effects on non-neuronal ACh which should be considered when re-assessing the environmental risks of these compounds. To our knowledge this is a new biological mechanism, and we suggest that, in addition to their well documented neurotoxic effects, neonicotinoids may contribute to honeybee colony losses consecutive to a reduction of the ACh content in the brood food.

Insecticide residues in pollen and nectar of a cucurbit crop and their potential exposure to pollinators.

Neonicotinoids are systemic insecticides widely used on many pollinated agricultural crops, and increasing evidence indicates that they move to some extent into pollen and nectar. This study measured levels of neonicotinoid residues in pollen and nectar from a pumpkin crop treated with formulated products containing imidacloprid, dinotefuran, and thiamethoxam using different timings and application methods. Environmental conditions have a significant effect on overall residue levels; nectar residues were 73.5-88.8% less than pollen residues, and metabolites accounted for 15.5-27.2% of the total residue amounts. Foliar-applied treatments and chemigated insecticides applied through drip irrigation during flowering resulted in the highest residues of parent insecticide and metabolites, which may reach average levels up to 122 ng/g in pollen and 17.6 ng/g in nectar. The lowest levels of residues were detected in treatment regimens involving applications of insecticides at planting, as either seed dressing, bedding tray drench, or transplant water treatment.

[An experimental study on chemically induced animal model of goat cleft palate in uterus].

OBJECTIVE: To study the method to prepare the animal model of goat cleft palate by injection of anabasine and the effect of the malformation on the development of the facial mid-part. METHODS: A total of 40 female boer hybrid goats were selected, aging 8-12 months and weighing 35-55 kg. The mating day was 0 day, and at 30 days the goats assured pregnant by B type ultrasonic test were divided into 4 groups (n=10) according to intramuscular injection of 10 (experimental group 1), 15 (experimental group 2), 20 (experimental group 3) mg/d, and no injection (control group), respectively, from the 31st to 42nd day. At pregnant 120 days and 1 month after birth, 5 fetal goats of each group were used for three dimensional reconstruction of skull with CT scan. The maxillary bone width named as PPMM and the maxillary bone length named as APMM were measured, then the hard palate general observation was performed and dry skull of goats was harvested to observe the development of maxillary. RESULTS: After injection, all pregnant lambs aborted in experimental group 3; 2 pregnant lambs aborted and 8 lambs maintained pregnancy in experimental group 2. At 120 days of pregnant, no cleft palate was observed in 5 fetal lambs of experimental group 1 and control group, respectively; cleft palate and maxillary dysplasia occurred in 3 fetal lambs of experimental group 2. Among 11 newborn lambs of experimental group 1 and 8 newborn lambs of control group, no cleft palate was observed; among 7 newborn lambs of experimental group 2, cleft palate occurred in 5 with obvious maxillary dysplasia and eating difficulty. General observation of hard palate and dry skull showed obvious hypoplasia of maxillary in experimental group 2. There were significant differences in PPMM and APMM between the experimental group 2 and the control group at pregnant 120 days and 1 month after birth (P < 0.05). Five lambs with cleft palates of experimental group 2 survived for 1-2 months. CONCLUSION: The animal models of goat cleft palate can established by intramuscular injection of anabasine at a dose of 15 mg/d from the 31st to 42nd day of pregnant. The facial character of the induced cleft palate goat is similar to that of human cleft palate.

Nuevas perspectivas en el diagnóstico y evolución del consumo de tabaco: marcadores de exposición / New perspectives in the diagnosis and tobacco consumption course: exposition markers

El tabaquismo representa un grave problema de salud pública. Se ha impulsado la búsqueda de marcadores de exposición ambiental o individual al humo del tabaco que permitan evaluar tanto medidas preventivas y políticas de salud pública, como poder verificar la exposición o constatar que el tratamiento se cumple. Como no existe el marcador ideal, se ha propuesto esta revisión para describir los principales marcadores biológicos y ambientales descritos hasta la actualidad y basándose en la evidencia disponible establecer sus principales indicaciones y su posible aplicabilidad (AU)

Smoking is a serious public health problem. It has led to the search for environmental or individual exposition markers of tobacco smoke that make it possible to evaluate preventive and political public health measures. This could be being able to verify the exposition or stating which treatment is complied with. As there is no ideal marker, this review was proposed to describe the principal biological and environmental markers described up to now and, based on the available evidence, establish their principal indications and possible applicability (AU)

Immunotoxic effects of smokeless tobacco on the accessory cell function of rat oral epithelium.

Smokeless tobacco (ST) is known to adversely effect the oral mucosa, but knowledge about the influence on immune defence is limited. Few studies have investigated the effect of ST on the local immune response. In the present study, we have assessed the effect of a crude Swedish moist snuff (SS) extract, alkaloids, and nitrosamines on T-cell mitogenic response to Con A using epithelial cells, including Langerhans cells, of the rat oral mucosa as accessory cells. SS extract at a concentration of 4% reduced the T-cell proliferation by 50% (IC50 = 4%). Pretreatment of either oral epithelial cells or T-cells with SS extract also gave a significant inhibition of T-cell proliferation. This effect was not obtained following preincubation with SS components as alkaloids and different tobacco-specific nitrosamines (TSNA). None of the tested compounds were found to possess any mitogenic properties. This in vitro study showed that SS extract can evoke an immunosuppressive effect on mitogen-driven T-cell proliferation using cells from oral epithelium as accessory cells. This effect was more pronounced when SS extract was employed compared to when the single SS components were used alone.

[Effect of anabasine hydrochloride on embryogenesis in white rats and rabbits]. / Vliianie anabazina gidrokhlorida na émbriogenez belykh krys i krolikov.

The author reports the results of testing the embryotropic activity of anabasineee hydrochloride in doses of 15, 5, and 3 mg/kg. It was found that oral administration of the drug to pregnant rats in doses exceeding 10-fold (5 mg/kg) and 20-fold (10 mg/kg) the therapeutic ones produced no adverse effect on the fetus. In a dose of 15 mg/kg the drug exerted a moderate embryotoxic action. Multiple oral administration of anabasin hydrochloride to rats in a dose of 3 mg/kg produced no embryotoxic effect. It is concluded that anabasin hydrochloride has no teratogenic properties.