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Digestion Time (digestion + time)
Selected AbstractsQuantification and ultrastructure of oosorption in Eretmocerus eremicus (Hymenoptera: Aphelinidae)JOURNAL OF MORPHOLOGY, Issue 9 2006Mark K. Asplen Abstract The potential for and ultrastructure of oosorption were examined in Eretmocerus eremicus, a short-lived whitefly parasitoid that obligately produces anhydropic oocytes. In the absence of hosts, median egg load decreased by ,12% per day between 2 days and 8 days following eclosion. Parasitoid mating status had no significant effect on either egg load alone or the relationship between egg load and age. Yolk degradation in E. eremicus is autolytic, with the enzymes required for yolk sphere digestion apparently being derived from within the ooplasm. The exochorion appear to be digested by the follicular epithelium concurrent with the uniform degradation of the entire ooplasm. The potential adaptive benefits of this novel oosorption mechanism to E. eremicus females include a reduction in the total digestion time per oocyte and resorption of chorion remnants. Finally, to our knowledge, the results of this study provide the first unequivocal ultrastructural evidence of a purely autolytic oosorption mechanism in Insecta. J. Morphol. © 2006 Wiley-Liss, Inc. [source] Kinetics of Urea Decomposition in the Presence of Transition Metal Ions: Ni2+JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2006Bora Mavis The literature on kinetics of the urea decomposition reaction was reviewed for the 333,373 K range of temperature. Possible reactions in the pH range of 5,9 were identified. Kinetic simulations indicated significant accumulation of the cyanate intermediate in the pH-time,temperature range that was studied. The effects of Ni2+ hydrolysis and complexation with the urea decomposition products were incorporated into the simulations. The kinetic simulation of the rate of Ni2+ removal from the solutions was compared against the experimental data. The experimental results indicated an agglomerative growth mechanism for the precipitation process. Chemical analyses showed that the composition of the precipitate varies with digestion time, in agreement with the predictions of the kinetic simulation. [source] DNA detection rates of host mtDNA in bloodmeals of human body lice (Pediculus humanus L., 1758)MEDICAL AND VETERINARY ENTOMOLOGY, Issue 3 2007J. S. DAVEY Abstract Using polymerase chain reaction, we investigated the extent to which digestion affects the potential to amplify 12S mitochondrial DNA sequences from bloodmeals of individual human body lice (Pediculus humanus L.) (Phthiraptera, Pediculidae) up to 72 h after feeding on a surrogate rabbit host (Oryctolagus cuniculus L.) (Lagomorpha, Leporidae). Two rabbit-specific primer pairs were developed to produce amplicons of 199 bp and 283 bp, the smaller of which was found to have a significantly slower decay rate. Median detection periods (T50) for the amplicons were 20 h and 12 h, with maximum detection periods of 24 h and 12 h, respectively, suggesting an inversely proportional linear relationship between amplicon size and digestion time. The data provide an indication of timeframes essential for the design of forensic sampling protocols and a basis for investigating the feeding frequency of human lice. [source] DigesTip: A new device for a rapid and efficient in-solution protein digestionPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 11 2008Roberto Marangoni Dr. Abstract DigesTip is a new device for in-solution protein digestion, based on a patent pending technology, able to immobilize enzymes (trypsin, in this case) on a solid surface, keeping their activity preserved. DigesTip is a standard pipette tip, usable both by human and by robots. Its main performances are: very short digestion time (1,min) and usability with low protein sample concentrations (5,,g/mL). DigesTip obtains a clear signal in MS measurements and its usage rules out several preparative steps. [source] Human Islet Isolation for Autologous Transplantation: Comparison of Yield and Function Using SERVA/Nordmark Versus Roche EnzymesAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2009T. Anazawa Islet autotransplantation (IAT) is used to preserve as much insulin-secretory capacity as possible in patients undergoing total pancreatectomy for painful chronic pancreatitis. The enzyme used to dissociate the pancreas is a critical determinant of islet yield, which is correlated with posttransplant function. Here, we present our experience with IAT procedures to compare islet product data using the new enzyme SERVA/Nordmark (SN group; n = 46) with the standard enzyme Liberase-HI (LH group; n = 40). Total islet yields (mean ± standard deviation; 216 417 ± 79 278 islet equivalent [IEQ] in the LH group; 227 958 ± 58 544 IEQ in the SN group; p = 0.67) were similar. However, the percentage of embedded islets is higher in the SN group compared to the LH group. Significant differences were found in pancreas digestion time, dilution time, and digested pancreas weight between the two groups. Multivariate linear regression analysis showed the two groups differed in portal venous pressure changes. The incidence of graft function and insulin independence was not different between the two groups. The SN and LH enzymes are associated with similar outcomes for IAT. Further optimization of the collagenase/neutral protease ratio is necessary to reduce the number of embedded islets obtained when using the SN enzyme. [source] Combined effect of incubation and ambient temperature on the feeding performance of a small ectothermAUSTRAL ECOLOGY, Issue 8 2006JOKE BILCKE Abstract Many ectothermic animals are subject to fluctuating environmental temperatures during incubation as well as post-birth. Numerous studies examined the effects of incubation temperature or ambient temperature on various aspects of offspring phenotype. We investigated whether incubation temperature and ambient temperature have an interactive effect on offspring performance. Our study animal, the ectothermic vertebrate Lampropholis delicata (common garden skink; De Vis 1888), experiences fluctuating environmental temperatures caused by differential invasion of an exotic plant Vinca major (blue periwinkle). In the laboratory, eggs from wild-caught females were assigned to different incubation temperatures that mimicked variation in natural nests. The feeding performance and digestion time of each hatchling was tested at ambient temperatures that represented environments invaded to different degrees by periwinkle. Incubation and ambient temperature interacted to affect a lizard's mobility, the time that it took to capture, subdue and handle a prey, and the number of handling ,errors' that it made while foraging. For a number of these characteristics, incubation-induced changes to a lizard's mass significantly affected this relationship. Irrespective of size, no interaction effect was found for digestion time: lizards digested food faster at warmer temperatures, regardless of incubation temperature. Thus, temperatures experienced during incubation may alter an animal's phenotype so that the surrounding thermal environment differentially affects aspects of feeding performance. Our results also demonstrate that incubation environment can induce changes to morphology and behaviour that carry over into a lizard's early life, and that in some cases these differences in phenotype interact to affect performance. We suggest that the immediate removal of exotic plants as part of a weed control strategy could have important implications for the foraging performance, and presumably fitness, of ectothermic animals. [source] The Effect of Helicobacter pylori Infection on Levels of DNA Damage in Gastric Epithelial CellsHELICOBACTER, Issue 5 2002S. M. Everett Abstract Background.Helicobacter pylori infection leads to an increased risk of developing gastric cancer. The mechanism through which this occurs is not known. We aimed to determine the effect of H. pylori and gastritis on levels of DNA damage in gastric epithelial cells. Methods. Epithelial cells were isolated from antral biopsies from 111 patients. DNA damage was determined using single cell gel electrophoresis and the proportion of cells with damage calculated before and 6 weeks after eradication of H. pylori. Cell suspensions generated by sequential digestions of the same biopsies were assayed to determine the effect of cell position within the gastric pit on DNA damage. Results. DNA damage was significantly higher in normal gastric mucosa than in H. pylori gastritis [median (interquartile range) 65% (58.5,75.8), n = 18 and 21% (11.9,29.8), n = 65, respectively, p < .001]. Intermediate levels were found in reactive gastritis [55.5% (41.3,71.7), n = 13] and H. pylori negative chronic gastritis [50.5% (36.3,60.0), n = 15]. DNA damage rose 6 weeks after successful eradication of H. pylori[to 39.5% (26.3,51.0), p = .007] but was still lower than in normal mucosa. Chronic inflammation was the most important histological factor that determined DNA damage. DNA damage fell with increasing digestion times (r = ,.92 and ,.88 for normal mucosa and H. pylori gastritis, respectively). Conclusions. Lower levels of DNA damage in cells isolated from H. pylori infected gastric biopsies may be a reflection of increased cell turnover in H. pylori gastritis. The investigation of mature gastric epithelial cells for DNA damage is unlikely to elucidate the mechanisms underlying gastric carcinogenesis. [source] | |||||||||||||