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31.
Attacking pain at its source: new perspectives on opioids 总被引:20,自引:0,他引:20
The treatment of severe pain with opioids has thus far been limited by their unwanted central side effects. Recent research promises new approaches, including opioid analgesics acting outside the central nervous system, targeting of opioid peptide-containing immune cells to peripheral damaged tissue, and gene transfer to enhance opioid production at sites of injury. 相似文献
32.
Halina Szatyłowicz Tadeusz Marek Krygowski Aneta Jezierska-Mazzarello 《Journal of molecular modeling》2011,17(1):125-131
Due to gradual and controlled changes of interatomic distances between heavy atoms in OH…F− of C6H5OH…F− systems it was possible to study the electronic structure evolution. Computation at B3LYP/6-311+G(d,p) level of theory was
performed for this purpose. Changes in charges at atoms and characteristics at bond critical points (BCPs) of the H-bond region
and also in distant parts of the systems were investigated by means of natural bond orbitals (NBO) and atoms in molecules
(AIM) analyses. It is shown that at the border line between partially covalent and non-covalent H-bonding (Espinosa et al.
in J Chem Phys 117:5529, 2002; Grabowski et al. in J Phys Chem B 110:6444, 2006) with the H…F interatomic distance ∼1.8 Ǻ the hydrogen atom has the most positive charge. In addition, the change in the
atomic charge values in the interacting region affects the phenyl ring properties. The decrease of the sum of atomic charges
as well as of the aromaticity was noticed when the OH….F distance is shortened. 相似文献
33.
34.
Phenol hydroxylase was inactivated by the arginine reagents 2,3-butanedione, 1,2-cyclohexanedione, and phenylglyoxal. The cosubstrate NADPH, as well as NADP+ and several analogues thereof, protected the enzyme against inactivation. Phenol did not protect the activity against any of the reagents used, nor did modification by 2,3-butanedione affect the binding of phenol. We propose the presence of arginyl residues in the binding sites for the adenosine phosphate part of NADPH. 相似文献
35.
Eva Pagacova Halina Cernohorska Svatava Kubickova Jiri Vahala Jiri Rubes 《Conservation Genetics》2011,12(1):71-77
Chromosomes of 228 captive specimens of the family Bovidae have been investigated. The examined animals were classified into
the subfamilies Aepycerotinae, Reduncinae, Antilopinae, Alcelaphinae, Hippotraginae and Bovinae. Polymorphism for one fusion
was identified in the species: Aepyceros melampus, 2n = 59–60; Redunca fulvorufula, 2n = 56–57; Kobus e. ellipsiprymnus, 2n = 50–52; Kobus e. defassa, 2n = 52–54 and Syncerus c. nanus, 2n = 54–55. This is the first study to reveal fusion 7;29 in Kobus e. defassa and simultaneously the respective polymorphism. Variation in the diploid number of chromosomes is also known in species:
Oryx g. dammah and Oryx g. leucoryx but in this study only fusion 1;25 was identified in both karyotyped species. Our study showed that 13% of investigated individuals
were polymorphic for the centric fusion and demonstrated the important role of cytogenetic screening in captive animals at
zoological gardens. 相似文献
36.
The binding of soybean agglutinin to human and rabbit erythrocytes, before and after treatment with trypsin, was reinvestigated with special emphasis on measurements at very low lectin concentrations. This communication presents two features of the binding that are observed only at the low concentrations used. (1) The trypsinized erythrocytes bind more lectin molecules than untreated cells at low concentrations (0.1–1.0 μg/ml), even though the total number of binding sites appears to be the same for both treated and untreated cells. It is suggested that this difference could explain, at least in part, the much higher susceptibility of the trypsin-treated cells to agglutination by soybean agglutinin. (2) At low site occupancy the binding of soybean agglutinin exhibits positive cooperativity, indicating a conformational change in the membrane. Trypsin-treated cells exhibit this effect at much lower lectin concentrations than untreated cells. 相似文献
37.
In plants, an electrical potential and circumnutation disturbances are a part of a response to environmental and internal stimuli. Precise relations between electrical potential changes and circumnutation mechanisms are unclear. We have found recently that glutamate (Glu) injection into Helianthus annuus stem induced a series of action potentials (APs) and a transient decrease in circumnutation activity. A theoretical explanation for this finding is discussed here taking into considerations data about the ion mechanism of AP and circumnutation as well as about the metabolic and signaling pathways of glutamate and their possible interactions.Key words: action potential, circumnutation, elongation, glutamate, Helianthus annuus, plant movement 相似文献
38.
Zbigniew Szybiński Stanisław Walas Paweł Zagrodzki Grzegorz Sokołowski Filip Gołkowski Halina Mrowiec 《Biological trace element research》2010,138(1-3):28-41
The purpose of this work was to determine trace element levels in urine and evaluate possible associations between urinary iodine concentration (UIC), other trace elements (Cr, Cu, Fe, Mn, Na, Se, Zn), toxic elements (Cd, Pb), anthropometrical measures (body weight and height), glycemic indices (serum insulin and glucose), and several parameters related to thyroid function (thyroid stimulating hormone, free thyroxine, antithyroid peroxidase antibodies, thyroid volume, and thyroid echogenicity) in pregnant women. One hundred sixty-nine participants were recruited. The whole study group, originating from Krakow region, comprised three subgroups belonging to three trimesters: I trimester (n?=?28), II trimester (n?=?83), and III trimester (n?=?58). Trace elements were determined using inductively coupled plasma mass/(atomic emission) spectrometry. Partial least square model was used to reveal correlation structure between parameters investigated, as well as a possible causal relationship between dependent parameters and potentially explanatory parameters. Results obtained for trace and toxic elements in urine were comparable with results of other authors, although the study group was not homogenous. We confirmed (1) low iodine excretion in pregnant women, (2) the existence of statistically significant correlation between UIC and urinary selenium, and (3) lack of correlation between latter parameter and typical indices of thyroid function. Urinary selenium correlated with other urinary trace elements, but physiological significance of this finding remains uncertain. The fact that a large number of pregnant women fail to meet dietary recommendations for iodine is the major reason for concern. 相似文献
39.
Maria Stolarz Elżbieta Król Halina Dziubińska Andrzej Kurenda 《Physiologia plantarum》2010,138(3):329-338
Reports concerning the function of glutamate (Glu) in the electrical and movement phenomena in plants are scarce. Using the method of extracellular measurement, we recorded electrical potential changes in the stem of 3‐week‐old Helianthus annuus L. plants after injection of Glu solution. Simultaneously, circumnutation movements of the stem were measured with the use of time‐lapse images. Injection of Glu solution at millimolar (200, 50, 5 mM) concentrations in the basal part of the stem evoked a series of action potentials (APs). The APs appeared in the site of injection and in different parts of the stem and were propagated acropetally and/or basipetally along the stem. Glu injection also resulted in a transient, approximately 5‐h‐long decrease in the stem circumnutation rate. The APs initiated and propagating in the sunflower stem after Glu injection testify the existence of a Glu perception system in vascular plants and suggest its involvement in electrical, long‐distance signaling. Our experiments also demonstrated that Glu is a factor affecting circumnutation movements. 相似文献
40.
Aleksandra Eckstein Patrycja Zi?ba Halina Gabry? 《Journal of Plant Growth Regulation》2012,31(1):90-101
Light and sugars are fundamental elements of plant metabolism and play signaling roles in many processes. They are also critical
factors determining the condition of plants cultured in vitro. The aim of this work was to investigate the simultaneous influence
of irradiance and sugar content in the medium on the growth and photosynthetic apparatus condition of Arabidopsis thaliana in vitro. Plants were grown on media containing 1 or 3% of sucrose or glucose at three irradiances: 25, 100, and 250 μmol m−2 s−1 (weak, medium, and strong light). Media without sugar were used for control plants. Plant growth parameters were measured
and the following physiological processes were investigated: photosynthesis, blue light-induced chloroplast relocations, and
xanthophyll cycle activity. The expression of genes related to these processes was analyzed. The presence of sugar in the
medium was found to be essential for the growth of Arabidopsis in vitro. Weak light significantly limited growth and the capacity to acclimate to changing light conditions. Strong light
was a source of stress in some cases. Contrary to earlier reports, exogenous sugars showed a positive effect on photosynthesis.
At higher concentration they acted as photoprotectants, overcoming the negative influence of strong light on photosynthesis
and the xanthophyll cycle. The expression of all investigated genes was influenced by irradiance and sugar presence. In many
cases differential effects of sugar type and concentration could be observed. The specific effects of some irradiance/sugar
concentration combinations point to possible interactions between sugar- and light-induced signaling pathways. 相似文献