Azaspiracids are a group of lipophilic polyether toxins produced by the small dinoflagellate Azadinium spinosum. They may accumulate in shellfish and can result in illnesses when consumed by humans. Research into analytical methods, chemistry, metabolism, and toxicology of azaspiracids has been severely constrained by the scarcity of high-purity azaspiracids. Consequently, since their discovery in 1995, considerable efforts have been made to develop methods for the isolation of azaspiracids in sufficient amounts and purities for toxicological studies, in addition to the preparation of standard reference materials. A seven-step procedure was improved for the isolation of azaspiracids-1-3 (1, 2, and 3) increasing recoveries 2-fold as compared to previous methods and leading to isolation of sufficiently purified azaspiracid-6 (6) for structural determination by NMR spectroscopy. The procedure, which involved a series of partitioning and column chromatography steps, was performed on 500 g of Mytilus edulis hepatopancreas tissue containing ~14 mg of 1. Overall yields of 1 (52%), 2 (43%), 3 (43%), and 6 (38%) were good, and purities were confirmed by NMR spectroscopy. The structure of 6 was determined by one- and two-dimensional NMR spectroscopy and mass spectrometry. The stability of 6 relative to 1 was also assessed in three solvents in a short-term study that demonstrated the greatest stability in aqueous acetonitrile. 相似文献
The prevalence of Dirofilaria immitis infection was evaluated in stray dogs of Erzurum, Turkey. A total of 123 whole-blood and 93 sera samples were collected from stray dogs older than 6 months were lived in animal shelter. The PCR and direct microscopic examinations were used for the detection of microfilaria and indirect-ELISA was performed for the detection of anti-D. immitis antibodies. The prevalence of D. immitis in the canine population was 8.1% by PCR, 2.1% by ELISA. In addition, microfilaria burdens of Dirofilaria sp. was 4.8% by direct blood smear examination. There was a statistical difference (P=0.05) in the prevalence between males (10.5%) and females (2.3%) by direct blood smear examination. Similarly there was a statistical difference (P<0.05) in the prevalence between males (15.8%) and females (4.7%) by PCR. Dogs belonging to the 0.5-1 years old group showed the highest prevalence than 2-4 ages group with three tests. Among the 93 samples screened by the ELISA, two samples were positive for the D. immitis antibodies. Both positive dogs with ELISA were females. 相似文献
Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) is a cosmopolitan species that feeds on numerous cultivated plants and herbaceaus plants. Agrotis ipsilon causes significant economic losses in various agricultural products, especially in indisturial plants and vegetables in Turkey and worldwide. In this study, the effects on the biology and reproductive potential of lettuce (Lactuca sativa L., Asteraceae), maize (Zea mays L., Poaceae), sugarbeet (Beta vulgaris var. saccharifera Alef.,Amaranthaceae) and potato (Solanum tuberosum L., Solanaceae) which are essential host plants of A. ipsilon were investigated under climatized conditions of 28?±?1 °C, 60%?±?10 r.h., and 16 h daily artificial light. The data obtained were analyzed by using an age-stage two-sex life table. Agrotis ipsilon had five larval stages fed on lettuce, whereas seven larval stages were fed on other host plants. Agrotis ipsilon showed the best development and reproduction on lettuce, followed by sugar beet. When A. ipsilon is reared on lettuce the intrinsic rate of increase (r?=?0.1237 d?1), finite rate of increase (λ?=?1.1317 d?1) and net reproductive rate (R0?=?403.06 offspring/individual) were found higher and the mean generation times (T?=?48.51 d) is shorter than those in other host plants. According to these results, A. ipsilon can cause the most damage to lettuce among studied plants.
This study was conducted to determine the in vitro effects of four commonly used pesticides (Nuarimol™, Fenarimol™, Parathion-methyl™ and 2,4-D™) on erythrocyte carbonic anhydrase (CA) activity from Saanen goats (SG). The enzyme was 262.57-fold purified by affinity chromatography and the purity was confirmed by SDS-PAGE. Inhibitory effect of the pesticides on the purified enzyme was determined using the CO2-hydratase activity method. IC50 values of the pesticides that caused inhibition were determined by means of activity percentage diagrams. The concentrations of Nuarimol™, Fenarimol™, and 2,4-D™ that inhibited 50% of the enzymatic activity were 0.352, 0.924 and 2.04 mM, respectively. Conversely, the enzyme activity was increased by parathion-methyl. 相似文献
Impinging/overriding dorsal spinous processes (DSPs) of the thoracolumbar vertebrae are a common cause of poor performance in horses. In the last five decades, numerous surgical treatments have been reported on, from transverse transection of the affected DSPs, and endoscopic resection of the affected DSPs, to transection of the interspinous ligament. Until recently, cosmetic outcomes have been reported as good to excellent in studies. However, a previously unreported complication of neurogenic atrophy of the contralateral epaxial muscle following desmotomy of the interspinous ligament has been recently reported. The authors hypothesised that this was because of a more lateral approach than previously described, resulting in the scissors being too far across midline and transecting a nerve in the region. Considering this finding, we have reviewed the literature on the neuroanatomy of the thoracolumbar region in the horse. Literature on the neuroanatomy of the horse is lacking when compared with that of humans and companion animals, with most of the work extrapolated from companion animals. Based on the current literature, we hypothesise that transection of an intermediate branch of the dorsal spinal nerve supplying the m. longissimus is potentially the cause of the post-operative neurogenic atrophy. The lack of detailed knowledge of the neural anatomy of the equine back has resulted in the role of local anaesthesia in localising pain in the equine back being poorly understood. The wide variation in techniques used for localising back pain may explain why some horses suffering from poor performance or an abnormal gait because of back pain improve to local anaesthesia of the back while others do not. This review article highlights a lack of anatomical knowledge regarding the equine thoracolumbar region in the literature despite diagnostic local anaesthesia, medication, and surgery in this area being relatively common. 相似文献