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801.
802.
Iwona Maszczynska Andrzej W. Lipkowski Daniel B. Carr Richard M. Kream 《Letters in Peptide Science》1998,5(5-6):395-398
Many years preclinical and clinical anatomic, pharmacologic, and physiologic studies suggest that SP- and opioid-expressing neurons produce opposite biological effects at the spinal level, i.e., nociception and antinociception, respectively. However, in certain circumstances intrathecally administered SP is capable of reinforcing of spinal morphine analgesia and may therefore function as an opioid adjuvant in vivo. The SP dose-response curve of spinally administered SP follows a bell-shaped or inverted-U configuration, permitting pharmacological dissociation of opioid-potentiating and analgesic properties of SP from traditional hyperalgesic effects seen at significantly higher concentrations. This analgesic effect is blocked by naloxone but unaffected by transection of the spinal cord, thus demonstrating the lack of supraspinal modulation. The present report briefly describes both reinforcing and opposing interactions between multiple opioid systems and substance P at the spinal level. We propose that a likely mechanism underlying SP-mediated enhancement of opioid analgesia is the ability of SP to release endogenous opioid peptides within the local spinal cord environment. 相似文献
803.
The paper deals with two main problems: it gives a unified approach to model building for observations obtained in a block design with nested rows and columns and it provides the analysis of variance for such data. Also, some statistical properties of the design are examined. 相似文献
804.
Maryla Szczepanik Iwona Dams & Czesaw Wawrzeczyk 《Entomologia Experimentalis et Applicata》2008,128(2):337-345
The application of antifeedants, often in combination with other methods within integrated pest management (IPM) strategies, has proven to be a good way to control insect pests. Little is known about compounds that have antifeedant activity against the lesser mealworm, Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae). The antifeedant properties of optically pure isomers of pulegone and isopulegol and some enantiomeric pairs of bicyclic terpenoid lactones with the p -menthane system, derived from these isomeric starting compounds, were studied in choice and no-choice tests with the lesser mealworm. The original monoterpenes and γ-spirolactones were weak feeding deterrents to larvae and adults of A. diaperinus . The δ-hydroxy-γ-spirolactones showed significant activity against adults, but substituting the hydroxy group with a ketone group considerably reduced the deterrent activity of the resulting δ-keto-γ-spirolactones. The bicyclic γ-hydroxy-δ-lactones with condensed rings and with the (1 S ,6 R ,8 R )-(+) and (1 R ,6 S ,8 S )-(–) configuration of the chiral centres, and δ-hydroxy-γ-lactone (1 S ,4 S ,6 S )-(+) were very strong antifeedants to both larvae and adults. The hydroxy groups and the configuration of the chiral centres of the molecules were very important features for determining the antifeedant activity of the lactones tested. Generally, the compounds studied were better antifeedants to adults than to larvae. 相似文献
805.
Izabela Gutowska Irena Baranowska-Bosiacka Marta Rybicka Iwona Noceń Wioletta Dudzińska Mariola Marchlewicz Barbara Wiszniewska Dariusz Chlubek 《Biological trace element research》2011,139(3):332-340
The mineral content of tooth hard tissue may influence the rate of decay change. Considering this fact, we aimed at examining
if type 1 diabetes might be a contributing factor to the appearance of tooth decay. The experiment was conducted on female
Wistar rats. To induce diabetes, rats were intravenously injected with 1 mL streptozocine 0.01 M citrate buffer. The control
group of rats was injected with 1 mL 0.01 M citrate buffer only. After 10 days, teeth and blood serum samples were obtained.
Fluoride concentration was determined by potentiometer method, and calcium and magnesium, by AAS. Serum concentrations of
glucose and estradiol in the diabetic rats were significantly higher compared to the control group. In the experimental group,
a statistically significant decrease of fluorine concentration in both teeth and serum were observed. Calcium and magnesium
concentrations in blood serum and dental magnesium concentration were significantly higher in rats with type 1 diabetes compared
with the control. A downward trend in the content of dental calcium in streptozotocin-induced diabetic rats was observed.
The results obtained indicate that caries initiation and progression could be promoted by metabolic changes associated with
diabetes affecting the mineral composition of tooth hard tissue. 相似文献
806.
Iwona Żur Ewa Dubas Elżbieta Golemiec Magdalena Szechyńska-Hebda Franciszek Janowiak Maria Wędzony 《Plant Cell, Tissue and Organ Culture》2008,94(3):319-328
The accumulation of abscisic acid (ABA) and the activities of antioxidative enzymes along with cell metabolic activity were
monitored during androgenesis induction in triticale (×Triticosecale Wittm.). Tested cultivars ‘Mieszko’ and ‘Wanad’ were selected due to their significantly different responses to androgenic
induction. Significant variation was observed in respect of superoxide dismutase activity and endogenous ABA content in anthers
isolated from freshly cut tillers. For both cultivars, tillers pretreatment with low temperature decreased peroxidase activity
by 36%, highly accelerated respiration rate and reduced heat production. At the same time, the level of ABA in ‘Mieszko’ was
increased to the level measured in ‘Wanad’. This effect was associated with higher microspore culture viability and increased
stress tolerance in ‘Mieszko’. Low temperature and metabolic starvation during 4-day anther preculture did not influence activities
of antioxidative enzymes, while it resulted in slight decrease in respiration rate and heat emission. The importance of these
changes for effective androgenesis induction is discussed. 相似文献
807.
Iwona B. Beech C.W. Sunny Cheung C.S. Patrick Chan Martin A. Hill Ricardo Franco Ana-Rosa Lino 《International biodeterioration & biodegradation》1994,34(3-4)
Two different species of sulphate-reducing bacteria, strain classified by NCIMB as Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (8313) isolated from the corroding heat exchanger, and SRB species recovered from a corroding ship hull anchored off the Indonesian coast (Indo isolate) were grown as laboratory batch cultures. Several factors such as the surface finish of substratum, metabolic activity of planktonic and sessile bacterial populations, initial attachment of cells to surfaces and subsequent formation of biofilms on the process of biodeterioration of mild steel in the presence of these two different species of SRB were investigated. The corrosion rates of mild steel were estimated by weight loss measurements and correlated with the density of sessile SRB population. The yield and composition of extracellular polymers released into the bulk phase of culture media were determined and the amount of dissolved hydrogen sulphide was monitored. The results revealed differences between SRB species in their aggressiveness towards mild steel under identical growth conditions, emphasising the importance of biochemistry and physiology of SRB for the biocorrosion process. Biochemical and genetic characterisation of SRB isolates chosen for this study are currently in progress. 相似文献