International Journal of Peptide Research and Therapeutics - Query fever is an important disease caused by Coxiella burnetii, therefore vaccination against this disease is so crucial. Com1 is one... 相似文献
(S)-(-)-Tropic acid is the acidic moiety of the tropane ester alkaloids, hyoscyamine and scopolamine (hyoscine). When tropic acid is fed to transformed root cultures of Datura stramonium L. or a Brugmansia (Datura) Candida x B. aurea hybrid, the formation of these alkaloids is inhibited. Phenyllactic acid, from which the tropoyl moiety is derived, is considerably less inhibitory. Label from (RS)-phenyl[1,3-13C2]lactic acid is incorporated at high levels into apoatropine, littorine, aposcopolamine, hyoscyamine, 7-hydroxyapoatropine, scopolamine and 7-hydroxyhyoscyamine when fed to these cultures. The presence of an excess concentration of unlabelled tropic acid has little influence on the specific incorporation into these products. It is concluded that free tropic acid is not an intermediate in hyoscyamine biosynthesis but rather that the rearrangement of phenyllactic acid occurs subsequent to its esterification.Abbreviations FM
fresh mass
- NMR
nuclear magnetic resonance spectroscopy
We are grateful to Drs. N.J. Walton, A.J. Parr, M.J.C. Rhodes (Institue of Food Research, Norwich) and B. Dräger (Münster, Germany) for helpful and critical discussions. We also wish to thank Dr. P. Bachmann (Braunschweig, Germany) for suggesting the use of the DB-17 column to separate littorine from hyoscyamine and for the modified Excel programme used to calculate the specific incorporations, Yannick Ford (AFRC Co-operative Award Studentship, University of Oxford) and Abigael Peerless for their able assistance, Dr. I. Colquhoun for assistance with some of the NMR spectroscopy and Drs. K. Shimomura (Tsukuba, Japan) and T. Hashimoto (Kyoto, Japan) for pure samples of 7-hydroxyhyoscyamine. J.G.W, gratefully acknowledges support from the Nuffield Foundation under the Small Grants Scheme to promote collaborative experimentation and M.A. is grateful to the Ministry of Education, Iran for a research scholarship. 相似文献
Failed oocyte activation has been observed in unexplained infertile (UI) and asthenoteratozoospermic (AT) men. The deficiency of phospholipase C‐zeta (PLCζ) could be a possible reason for such failures and has not been studied yet. We investigated the expression and localization of PLCζ protein in the sperms of patients with UI and AT conditions. The relationships between PLCζ‐related parameters with male age, sperm characteristics, DNA integrity, and cellular maturity were assessed. Semen samples were collected from fertile (n = 40), UI (n = 40), and AT (n = 40) men. Subsequently, semen analysis, DNA fragmentation, hyaluronic acid‐binding ability, and PLCζ level along with its distribution were evaluated using computer‐assisted sperm analyzer, sperm chromatin structure assay (SCSA), hyaluronic acid‐binding assay (HBA), western blot analysis and immunofluorescence microscopy, respectively. Unlike SCSA, the values of HBA, and PLCζ expression were significantly reduced in UI and AT patients compared to fertile men, whereas no significant differences were observed among the experimental groups in terms of PLCζ localization patterns. The regression analysis also showed that HBA is the only variable associated with PLCζ levels. Furthermore, the correlation of male age with PLCζ localization in postacrosomal, equatorial, and acrosomal+postacrosomal+equatorial (A+PA+E) patterns, as well as the relation of normal morphology, with the (A+PA+E) pattern, remained in the regression model. Our findings indicated that reduced PLCζ level along with the increased DNA fragmentation and impaired maturation may be possible etiologies of decreased fertilization in the studied subjects. 相似文献
Rapid adaptation to global change can counter vulnerability of species to population declines and extinction. Theoretically, under such circumstances both genetic variation and phenotypic plasticity can maintain population fitness, but empirical support for this is currently limited. Here, we aim to characterize the role of environmental and genetic diversity, and their prior evolutionary history (via haplogroup profiles) in shaping patterns of life history traits during biological invasion. Data were derived from both genetic and life history traits including a morphological analysis of 29 native and invasive populations of topmouth gudgeon Pseudorasbora parva coupled with climatic variables from each location. General additive models were constructed to explain distribution of somatic growth rate (SGR) data across native and invasive ranges, with model selection performed using Akaike's information criteria. Genetic and environmental drivers that structured the life history of populations in their native range were less influential in their invasive populations. For some vertebrates at least, fitness‐related trait shifts do not seem to be dependent on the level of genetic diversity or haplogroup makeup of the initial introduced propagule, nor of the availability of local environmental conditions being similar to those experienced in their native range. As long as local conditions are not beyond the species physiological threshold, its local establishment and invasive potential are likely to be determined by local drivers, such as density‐dependent effects linked to resource availability or to local biotic resistance. 相似文献
Dromedary camels (Camelus dromedarius) play a major economic role in many countries in Africa and Asia. Although they are resistant to harsh environmental conditions, they are susceptible to a wide range of zoonotic agents. This study aimed to provide an overview on the prevalence of selected zoonotic pathogens in blood and tissues of camels in central Iran. Blood, liver, portal lymph node, and brain were collected from 100 apparently healthy camels at a slaughterhouse in Qom city to assess the presence of DNA of Brucella spp., Trypanosoma spp., Coxiellaburnetii, and Bartonella spp. PCR products were sequenced bidirectionally and phylogenetic analyses were performed. Eleven percent of camels tested positive for Brucellaabortus (3%) and Trypanosomaevansi (8%). Coxiellaburnetii and Bartonella spp. DNA was not detected. Our data demonstrate that camels from Iran contribute to the epidemiology of some zoonotic pathogens. Performing proper control strategies, such as vaccination of camels and humans in contact with them, test-and-slaughter policy, and education of the general population is necessary for minimizing the risk of zoonotic infection. 相似文献
Sensitization to psychostimulant drugs, as well as morphine, subjected to cross-sensitization with stress. The development of morphine sensitization is associated with enhancements in dopamine overflow in the Nucleus accumbens (NAc). This study aimed to examine the role of accumbal D1/D2-like dopamine receptors in restraint stress (RS) induced sensitization to morphine antinociceptive effects. Adult male Wistar rats weighing 220–250 g underwent stereotaxic surgery. Two stainless steel guide cannulae were bilaterally implanted, 1 mm above the NAc injection site. Different solutions of SCH-23390, as a D1-like receptor antagonist or sulpiride, as a D2-like receptor antagonist, were microinjected into the NAc five min before exposure to RS. Restraint stress lasted for 3 h, 10 min after RS termination; animals received a subcutaneous injection of morphine (1 mg/kg) for 3 consecutive days. The procedure was followed by a 5-day drug and/or stress-free period. After that, on the 9th day, the nociceptive response was evaluated by the tail-flick test. The results revealed that intra-NAc administration of D1/D2-like dopamine receptor antagonists, SCH-23390 or sulpiride, respectively, blocked morphine sensitization-induced by RS and morphine co-administration in rats for three consecutive days. This work provides new insight into the determinant role of accumbal dopamine receptors in morphine sensitization produced by RS-morphine co-administration.
Biodiversity and Conservation - Palaeoecology is increasingly contributing to conservation biology and restoration ecology by extending the recent annual to decennial records of ecological... 相似文献
Biochemical Genetics - Several studies have noted that vitamin D receptor (VDR) gene polymorphisms are involved in the susceptibility to Coronary artery disease (CAD). Nonetheless, the results have... 相似文献
International Journal of Peptide Research and Therapeutics - Appetite is controlled by a complex system of central and peripheral signals interacting to modulate the ingestion response. Several... 相似文献