Showing papers on "Incubation published in 1988"
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TL;DR: It is concluded that incubation periods are longer than previously reported; there is a distinct knee in the incubation period distribution at seven months which suggests two risk populations; and that there is an increase in incidence which is consistent with exponential growth.
Abstract: A recent seroprevalence study of newborns indicates that one in 62 children born in New York City has antibodies to the human immunodeficiency virus (HIV)1. The distribution of incubation periods for paediatric patients is needed to estimate future AIDS case loads from these seroprevalence data. Current estimates of incubation periods for paediatric patients are based on limited data2–5. We use parametric5,6 and non-parametric7,8 methods to analyse incubation periods for 215 paediatric patients with AIDS whose only known route of infection is maternal. We conclude that incubation periods are longer than previously reported9; that there is a distinct knee in the incubation period distribution at seven months which suggests two risk populations; and that there is an increase in incidence which is consistent with exponential growth.
192 citations
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TL;DR: The kinetics of change in the extent of hyperactivation and in acrosomal loss, although measured in different cell populations, are consistent with an association between these two events.
Abstract: The occurrence and time course of capacitation, acrosomal loss, and hyperactivated motility require quantitative definition in order to characterize fertile human sperm. In this study, video microscopy and digital image analysis were used to measure curvilinear (VCL) and straight line (VSL) velocity, average linearity of progression (UN [100 x VSL/VCUJ), maximum and mean amplitude of lateral head displacement (ALH), beat-cross-frequency (BCF), DANCE (VCL x meanALH) and DANCEMEAN (meanALH/(UIN/100)). These parameters were measured for sperm in semen and in the swim-up fraction of washed cells during incubation for up to 24 h under in vitro fertilization (IVF) conditions. Acrosomal loss was monitored in the same population of washed cells by an immunofluorescence end-point assay. The greatest increase in mean values of motility parameters was observed when seminal sperm were washed free of seminal plasma. Increases continued for up to 6 h of incubation. Two subpopulations of hyperactivated sperm were identified; one type, not found in semen, showed star-spin trajectories, and constituted 3.0, 3.8, 4.5, and 4.1% of the swim-up population after 0, 3, 6 and 24 h of incubation. The second type, termed transitional showed a more progressive trajectory and constituted less than 1% in semen. In total, hyperactivated cells constituted 0.8% of cells in semen, 14.5% of the swim-up population with no incubation, and 23.1, 22.7, and 19.4% after 3, 6, and 24 h of incubation, respectively. Acrosomal loss in the swim-up population was delayed during the first 3 h of incubation, then increased from near 5% at 3 h to 7 and 12% at 6 and 24 h, respectively. The kinetics of change in the extent of hyperactivation and in acrosomal loss, although measured in different cell populations, are consistent with an association between these two events.
159 citations
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TL;DR: Alevin survival to emergence was high for all species, except for coho and pink salmon at 14 °C, and coho salmon hatched and emerged sooner at all temperatures than the other species.
Abstract: Embryo and alevin survival, time to hatching and emergence, and alevin and fry size of five species of Pacific salmon (Oncorhynchus) were observed at five incubation temperatures (2, 5, 8, 11, and ...
138 citations
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TL;DR: In this article, the authors monitored the net S and n mineralization in forested and cultivated Typic Cryoboralfic soils over 37 wk in a laboratory incubation experiment with intermittent leaching.
Abstract: Net S and n mineralization in forested and cultivated Typic Cryoboralfic soils was monitored over 37 wk in a laboratory incubation experiment with intermittent leaching. Patterns of net S and N release depended on the management histories of the soils. Several kinetic models were evaluated for the ability to accomodate continuously decreasing rates, a large initial flush of mineralization, a mineralization lag within the first 13 wk of incubation, or a constant rate of release near the end of incubation. (...)
128 citations
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TL;DR: It is concluded that feeding of the female by the male is a nutritional contribution and that the shorter incubation period and increased hatching success enhance the fitness of both parents.
125 citations
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121 citations
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TL;DR: Experiments suggest that active and guanidine-activated PAI-1 represent a single form of PAi-1, which is capable of reactivation and another that appears to be irreversibly inactivated.
Abstract: The plasminogen activator inhibitor 1 (PAI-1) synthesized and released by cultured bovine aortic endothelial cells is present in conditioned medium in a latent form that can be activated by guanidine hydrochloride [Hekman, C. M., & Loskutoff, D. J. (1985) J. Biol. Chem. 260, 11581-11587]. The purified, guanidine-activated PAI-1 was shown to inhibit both plasmin and trypsin in a dose- and time-dependent manner. Second-order rate constants for these interactions were calculated to be 6.6 X 10(5) and 7.0 X 10(6) M-1 s-1 for plasmin and trypsin, respectively. Experiments were conducted to compare the inherently active and the guanidine-activated forms of PAI-1. The two active forms had similar kinetic parameters for interaction with urokinase (Kd, 0.3 pM; kassoc, 1.5 X 10(8) M-1 s-1) and were both inactivated upon treatment with acid or base and by incubation at 37 degrees C. The latent form was relatively stable when incubated under similar conditions. The decrease in PAI-1 activity upon incubation at 37 degrees C was partially restored by a second treatment with guanidine hydrochloride. However, the degree of recovery decreased as a function of incubation time at 37 degrees C. These data suggest that active and guanidine-activated PAI-1 represent a single form of PAI-1. Incubation of this form at 37 degrees C yields two distinct populations of inactive PAI-1, one capable of reactivation and another that appears to be irreversibly inactivated.
93 citations
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TL;DR: IL-1 bioactivity, as measured in the thymocyte proliferation assay, was found to disappear upon incubation with endopeptidase 24.11, suggesting a possible role in the inactivation of immune system mediators.
Abstract: Endopeptidase 24.11 (enkephalinase) is a membrane bound protease involved in the degradation of neuropeptides and hormones. Its presence on cells of the thymus and lymph nodes suggests a possible role in the inactivation of immune system mediators. IL-1 (both purified IL-1 beta and an IL-1-rich supernatant) bioactivity, as measured in the thymocyte proliferation assay, was found to disappear upon incubation with endopeptidase 24.11. This inactivation was dependent on both incubation time and enzyme concentration. IL-1 beta was protected by the presence in the incubation medium of phosphoramidon, a specific inhibitor of endopeptidase 24.11. After incubation of IL-1-rich supernatant with the enzyme, the thymocyte proliferation activity could be restored by adding purified IL-1 beta to the samples, indicating that neither the enzyme nor the buffer had any toxic effect on thymocyte proliferation. In the same experimental conditions, IL-2 activity was not destroyed by endopeptidase 24.11.
93 citations
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TL;DR: It is proposed that the failure to soften normally at elevated temperature is due, in part, to the suppression of polygalacturonase mRNA and that the inhibition of other facets of ripening at 35°C is due to the inhibition or reduced expression of other, as yet unidentified, ripening-related genes.
Abstract: . Ripening tomato fruits incubated at 35°C fail to achieve normal pigmentation, soften little and show a marked decline in ethylene evolution. Labelling studies in vivo indicate that protein synthesis continues throughout incubation at 35°C although the spectrum of labelled proteins is different to that observed at 25°C. Translation of mRNAs in vitro shows traces of several ‘heat-shock’ mRNAs at 35°C and the loss of several others normally found in fruit ripened at 25°C. Using ripening-related cDNA clones as hybridization probes the expression of 12 ripening-related genes was followed during incubation at 25°C and 35°C. In general, there was a marked decline in the amounts of these mRNAs following incubation of ripening fruit at 35°C. In particular, mRNA homologous to pTOM 6, a cDNA clone coding for polygalacturonase, a major cell wall degrading enzyme, showed a rapid decline following incubation at 35°C and after 72-h at elevated temperature was undetectable. There was no recovery of expression during 120 h at 35°C and the application of exogenous ethylene did not overcome the inhibition of ripening or lead to the renewed accumulation of polygalacturonase mRNA. It is proposed that the failure to soften normally at elevated temperature is due, in part, to the suppression of polygalacturonase mRNA and that the inhibition of other facets of ripening at 35°C is due to the inhibition or reduced expression of other, as yet unidentified, ripening-related genes.
75 citations
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TL;DR: The spontaneous appearance of unusual colony forms was observed during prolonged growth of Bacteroides gingivalis W50 in a chemostat and the relatedness of W50/BR1 and W 50/BE1 to the parent strain was confirmed by comparisons of the whole-cell fatty-acid profiles, the patterns of pre-formed enzymes and by the metabolic end products after growth.
Abstract: The spontaneous appearance of unusual colony forms was observed during prolonged growth of Bacteroides gingivalis W50 in a chemostat. Two variants were selected for further study which could be distinguished from the parent strain by the rate and intensity of pigmentation of their colonies. For example, after anaerobic incubation for 14 days, variant W50/BR1 produced brown colonies whereas those of the parent strain were black; in contrast, variant W50/BE1 did not show signs of pigmentation until incubation had continued for 21 days. In subsequent studies in the chemostat, variant W50/BE1 bred true even after prolonged growth whereas other colony forms appeared after incubation of variant W50/BR1 for 14 days. The relatedness of W50/BR1 and W50/BE1 to the parent strain was confirmed by comparisons of the whole-cell fatty-acid profiles, the patterns of pre-formed enzymes and by the metabolic end products after growth. However, the variants did differ from the parent strain in their virulence in a mouse pathogenicity model. The parent strain killed all mice given infective doses > 5 × 108 cfu whereas W50/BR1 wasmuch lessvirulent (2 out of 10 mice killed and higher infective doses needed for higher mortality rates) and W50/BE1 was avirulent at all infective doses tested.
73 citations
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TL;DR: In this paper, the authors observed the changes occurring in the different phosphorus pools in sludge-amended soils during incubation using nuclear magnetic resonance spectroscopy (³¹P NMR) to qualitatively and quantitatively register P transformations.
Abstract: The purpose of the experiment was to observe the changes occurring in the different phosphorus (P) pools in sludge-amended soils during incubation using ³¹P nuclear magnetic resonance spectroscopy (³¹P NMR) to qualitatively and quantitatively register P transformations. An acid and an alkaline soil were each incubated with sludges that underwent different digestion processes. The ³¹P NMR spectra of those soils after 1, 28, 70, and 140 d of incubation showed that P diesters completely hydrolyzed after 28 d of incubation in both soils, irrespective of the type of sludge incorporated. After 140 d of incubation, P monoesters were still detected in the acid soil while they had completely hydrolyzed in the alkaline soil. Pyrophosphates were detected after 70 d of incubation in the alkaline soil and 140 d of incubation in the acid soil. The study suggested that acidity has an adverse effect on the microbial degradation of P monoesters and pyrophosphates in sludge-amended soils. Contribution from the Dep. of Soil and Environmental Sciences and the Dep. of Chemistry, Univ. of California, Riverside, CA 92521.
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TL;DR: The bimodal response of eggs to cold shocks was essentially different from the responses found by other authors who researched gynogenesis in carp using NaCl/urea solutions and temperatures below 24°C for incubation.
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TL;DR: It is concluded that the differences between incubation periods of the six scrapie models depend mainly on the rate of a continuous process of replication and spread of infection in the peripheral and central nervous system, which is predetermined by scrapie strain and host genotype.
Abstract: The pathogenesis of intraperitoneally injected ME7 scrapie has been studied in two Sinc genotypes of mice which gave predictable but widely different incubation periods. Comparisons were made with three other mouse scrapie models and one model in hamsters (involving different strains of agent and an untyped isolate from sheep). Average incubation periods ranged from 114 days in the fastest model (263K/hamsters) to 482 days in the slowest (ME7/Sincp7 mice). There were only small differences between models in the times of onset of replication in spleen and cervical lymph nodes. We suggest that the lymphoreticular stage of pathogenesis initiates neuroinvasion in the peripheral nervous system within a few days to a few weeks of infection. Thereafter, pathogenesis appears to be dominated by neural events and replication in brain becomes detectable after approximately 54% of the remaining incubation period has elapsed, irrespective of its length. It is concluded that the differences between incubation periods of the six scrapie models depend mainly on the rate of a continuous process of replication and spread of infection in the peripheral and central nervous system, which is predetermined by scrapie strain and host genotype. The unpredictability of some other scrapie models (and the natural disease) could be explained by additional factors which restrict neuroinvasion from the lymphoreticular system.
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TL;DR: In this article, the carbon and nitrogen mineralization rates were determined for an arable soil during 12 weeks at 37°C using an aerobic incubation-leaching technique, and the results showed that the amounts of mineralized C and N were compared to changes in the contents of C and nitrogen in microbial biomass (as determined by the chloroform fumigation incubation method; CFIM) during the incubation and to amounts of organic c and N in the leachates.
Abstract: Net carbon and nitrogen mineralization rates were determined for an arable soil during 12 weeks at 37†C using an aerobic incubation-leaching technique. The amounts of mineralized C and N were compared to changes in the contents of C and N in microbial biomass (as determined by the chloroform fumigation incubation method; CFIM) during the incubation and to amounts of organic C and N in the leachates. Microorganisms were also followed by direct counting of bacteria, measurements of total hyphal lengths and fluorescein diacetate (FDA)-active hyphae, and by most probable number determinations of protozoa (naked amoebae and flagellates). Numbers of naked amoebae increased nearly 10-fold initially and then decreased between weeks 6 and 12. Bacterial numbers and FDA-active hyphae decreased during the incubation, and the relative composition changed slightly in favour of bacteria. Total hyphal lengths remained almost constant. A total of 105 μg N g' − soil dry wt and 1179 μg C g − soil dry wt was mineralized during the incubation, while the microbial N pool decreased by 42 γm − soil dry wt and the microbial C pool decreased by 225μ g − soil dry wt. Soluble organic matter in the leachates amounted to 16 and 31% of mineralized C and N, respectively. The possibility of measuring C mineralization with less frequent teachings and determinations of N mineralization offers an easy method for assessing changes in labile soil organic matter over time or for comparisons between soils. Through the use of appropriate C-to-N ratios, the N-content in the labile pool can be calculated.
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TL;DR: Hydration of tissues in hatchlings was higher when incubated was in cool, moist conditions than when incubation was in warm, dry settings, thereby indicating that some of the effects of moisture and temperature on mobilization of nutrients by embryos may be mediated by differences in intracellular water.
Abstract: Flexible-shelled eggs of common snapping turtles (Chelydra serpentina) were incubated on each of two substrates (vermiculite, sand) at each of three temperatures (26.0°C, 28.5°C, 31.0°C) and three moisture regimes (wet, intermediate, dry). Embryos developing in cool, wet environments mobilized the largest amounts of protein from their yolk and attained the largest size before hatching, whereas turtles developing in warm, dry environments mobilized the smallest quantities of protein and were the smallest in body size at hatching. Embryos on wet substrates mobilized more lipid from their yolk than did embryos on dry media, but ambient temperature had no demonstrable influence on patterns of lipid mobilization. The total reserve of neutral lipid available in residual yolk plus carcass to sustain neonates in the interval prior to the beginning of feeding was largest in hatchlings from dry environments and smallest in animals from wet environments, but was unaffected by temperature during incubation. Hydration of tissues in hatchlings was higher when incubation was in cool, moist conditions than when incubation was in warm, dry settings, thereby indicating that some of the effects of moisture and temperature on mobilization of nutrients by embryos may be mediated by differences in intracellular water. Patterns of response to temperature and moisture recorded for turtles emerging from eggs on sand were similar to those recorded for hatchlings on vermiculite, so no important conclusion would have been affected by incubating eggs on one medium instead of the other.
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TL;DR: Wilson's phalarope (Phalopus tricolor) is characterized by intense female intrasexual competition and exclusive male parental care and females occasionally are polyandrous and no territories are defended.
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TL;DR: The ability of Listeria monocytogenes to grow or survive was determined using tryptose broth at pH 5.6 or 5.0 and in the presence of all concentrations of benzoate except 0.25 or 0.3%, which prohibited growth throughout a 264-h incubation period.
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TL;DR: IL-1 causes a reversible decrease in the insulin content of islet cells and an irreversible decrease in glucagon content, and these actions of IL-1 do not appear to account for the beta-cell-specific destruction of islets characteristic of type 1 diabetes.
Abstract: Recent observations suggest a role for interleukin-1 (IL-1), a polypeptide product of macrophage/monocytic cells, in the immune-mediated destruction of pancreatic islet beta-cells observed in type 1 diabetes. In this study, we investigated the effects of IL-1 on both alpha- and beta-cell secretory functions in rat islet cell monolayer cultures. Insulin release was 97% inhibited after 6 h of incubation in RPMI-1640 medium (11 mM glucose) containing 1 U/ml IL-1 and 96% inhibited after 24 h of incubation in medium containing 0.1 U/ml IL-1. The cell content of insulin in the monolayers was decreased by 66% (P less than 0.01) after 4 days of incubation in 10 U/ml IL-1; however, after a further 8-day incubation in IL-1-free medium, cell insulin content recovered fully. In contrast, cell glucagon content was decreased by 77% (P less than 0.001) after 4 days of incubation in 10 U/ml IL-1 and did not recover after a further 8-day incubation in IL-1-free medium. After an 18-h preincubation in medium with 0.1 and 1 U/ml IL-1, insulin release responses to 16.7 mM glucose were abolished in 4-h incubations, whereas responses to 0.1 mM 3-isobutyl-1-methylxanthine were normal, and after a further 2 and 5 days of incubation in IL-1-free medium, insulin responses to 16.7 mM glucose recovered fully. Similarly, the inhibitory effect of 16.7 mM glucose on glucagon release was lost after an 18-h preincubation in 0.1 and 1 U/ml IL-1, and did not recover fully after 2 and 5 days in IL-1-free medium, whereas the stimulatory effect of 3-isobutyl-1-methylxanthine on glucagon release was not affected by IL-1. We conclude that 1) IL-1 inhibits glucose-dependent and not cAMP-dependent mechanisms of insulin and glucagon release; 2) inhibition of glucose-stimulated insulin release by IL-1 is reversible, whereas the effect on glucose-modulated glucagon release is not; and 3) IL-1 causes a reversible decrease in the insulin content of islet cells and an irreversible decrease in glucagon content. These actions of IL-1 do not appear to account for the beta-cell-specific destruction of islets characteristic of type 1 diabetes.
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17 Mar 1988
TL;DR: In this paper, a polymerase chain reaction (PCR) is performed in an incubator with at least two reservoirs (14) of which each contains a liquid (16) which can be set to a defined temperature.
Abstract: The invention relates to an incubator (10) which is provided, in particular, for the polymerase chain reaction (PCR). The incubator (10) is provided with at least two reservoirs (14) of which each contains a liquid (16) which can be set to a defined temperature. In addition, an incubation chamber (12) is provided for receiving a holding device (50) for incubation cuvettes (52). The incubation cuvettes (52) situated in the incubation chamber (12) can be sequentially brought into contact as desired with the liquids (16) of the individual reservoirs (14). For this purpose, each reservoir (14) is connected to the incubation chamber (12) by a pipe (18, 24, 28; 20, 30, 34). Each pipe has a valve device (22). In addition, a device (26, 32, 38) for the selected transport of the liquid (16) of a reservoir (14) between the incubation chamber (12) and the corresponding reservoir (14) is provided between the incubation chamber (12) and the individual reservoirs (14). In order to accelerate the molecular motion of the reagents situated in the incubation cuvettes (52), the incubation chamber (12) can be provided with an ultrasonic generator (56) and/or with a microwave generator (58).
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TL;DR: In this paper, the authors examined the effects of a break (incubation) on solutions to a geometric insight problem and found that subjects receiving an analogical hint during incubation obtained more solutions than continuously working controls.
Abstract: This research examined the effects of a break (incubation) on solutions to a geometric insight problem. Experiment 1 showed that subjects receiving an analogical hint during incubation obtained more solutions than continuously working controls. Experiment 2 tested the hypothesis that incubation effects are due to the total time (including intermittant problem solving during incubation) spent on a problem. Subjects given relaxation instructions and no task during a problem-solving break were more successful than those who worked continuously for 20 min or were given demanding mental work as an intervening task. Self-report data supported the explanation that incubation effects are a result of covert effort and that the effectiveness of an analogical hint depends on the solver's ability to relate it to the problem.
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TL;DR: In this article, a laboratory incubation experiment was conducted to study the effect of organic amendment and moisture regimes on the immobilization-remineralization of NO3-N and total N balance in soil fertilized with KNO3.
Abstract: A laboratory incubation experiment was conducted to study the effect of organic amendment and moisture regimes on the immobilization-remineralization of NO3-N and total N balance in soil fertilized with KNO3. Immobilization of NO3-N was very rapid in soil amended with glucose and sucrose followed by a remineralization of organic N and accumulation of mineral N. Cellulose caused a slow but continued immobilization and did not show net accumulation of mineral N during 8 weeks of incubation. At the end of incubation, a significant increase in total N and organic N content of the soil was observed which is perhaps attributable to the activity of free living N2 fixers. Although N losses seemed to have occurred at 100% WHC through denitrification in soil amended with glucose and sucrose, main cause of NO3 elimination was microbial immobilization.
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TL;DR: It is indicated that GH rapidly alters glucose uptake in 3T3-F442A adipocytes, which most likely play a major role in the GH-induced changes in the conversion of glucose to lipid and CO2 observed previously.
Abstract: In differentiated adipocytes of the 3T3-F442A cell line, 4-h incubation with human GH transiently stimulates glucose oxidation and lipid accumulation. When the incubation is extended to 48 h, hGH suppresses these indicators of glucose metabolism. The stimulation of glucose oxidation or lipid accumulation required a period of serum deprivation before incubation with GH, while the later inhibitory effect of GH occurred equally well whether or not cells were serum-deprived. Since the 3T3-F442A adipocytes differentiate in culture from preadipocyte fibroblasts, we examined the importance of the state of differentiation on metabolic responses to GH. GH had no reproducible effect on glucose oxidation after 4 or 48 h in the preadipocyte fibroblasts. To determine whether the effects of GH on glucose metabolism involved changes in glucose transport, the uptake of a low concentration (558 nM) of [14C]glucose was measured in the adipocytes. Glucose uptake increased 2- to 4-fold after 5–15 min of incubation with GH. T...
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TL;DR: The temporal changes between nutrient intake and plasma levels ofPRL at the start and end of incubation behavior suggested that changes in nutrient intake may not cause changes in the concentration of PRL, whereas the association between increased levels of PRl and decreased levels of estradiol suggested that they may be causally associated.
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TL;DR: The production of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha by CL from rhesus monkeys and the incubation conditions that permit assessment of their synthesis were examined, and various exogenous factors were examined for their potential to modify PG production.
Abstract: Prostaglandins (PGs) are produced by the corpus luteum (CL) of many domestic and laboratory species and may play a role in CL regulation. The production of PGs by luteal tissue of the rhesus monkey has yet to be clearly elucidated. The production of PGE2, PGF�, and 6-keto-PGF1� by CL from rhesus monkeys and the incubation conditions (time and cell number) that permit assessment of their synthesis were examined. CL (n 3 per characterization) were surgically removed from nonpregnant monkeys during the mid-luteal phase of the menstrual cycle (‘--P8-10 days after ovulation). Luteal tissue was dissociated and the cells were incubated at varying concentrations for increasing periods of time at 37#{176}C. Subsequent to defining incubation conditions, various exogenous factors were examined for their potential to modify PG production. Indomethacin, calcium ionophore, human chorionic gonadotropin (hCG), estradiol-1 7f3 (E2), progesterone (P), testosterone (T), dihydrotestosterone (DHT), and 1-4-6 androstatriene-3, 1 7-dione (ATD) were incubated with luteal cells in increasing doses. PG and P concentrations in the medium were determined by radioimmunoassay. PGs in the medium after 6 h incubation were detectable at all cell concentrations tested (50,000, 100,000, 200,000 cells! tube). Concentrations of PGs and P increased with cell number (p<0.05). Luteal cells (50,000 cells/tube) were incubated for times of 0-24 h. Concentrations of P, PGE2, and PGF,� in the medium were relatively low prior to incubation (0 h), increased (p<0.05) linearly within the first 6-12 h, and plateaued through the remaining 24 h. A similar pattern was observed for concentrations of 6-keto-PGF1�. Incubation times of 6-12 h were deemed appropriate for subsequent studies as they provided PG concentrations detectable and above baseline (0 h). Indomethacin, a PG-synthesis inhibitor, decreased concentrations of PGs in the medium in a dose-dependent manner (p<0.05). The highest dose of indomethacin prevented any increase in concentrations of PGs above the levels prior to incubation. There was no effect on P concentrations. Conversely, hCG had no effect on PG production but stimulated Pproduction in a dose-dependent manner (p< 0.05). Calcium ionophore, a stimulator of PG synthesis, increased PGF�, PGE2 (p<0.01), and 6-keto-PGF1a (p<0.05) in a dose-dependent manner. Other hormones (T, P, E2, DHT, A TD) did not influence P and PG production, and thus had no acute effect on luteal function in vitro. The observations made in this study substantiate that the CL of the rhesus monkey synthesizes PGs. Further studies are necessary to identify and define the roles that luteal PGs may play in the regulation of the primate CL.
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TL;DR: Survival of eggs of chum salmon Oncorhynchus keta was determined at Carnation Creek, British Columbia, with two devices that were designed to help assess factors influencing incubation and to cause minimum disturbance of natural stream gravels.
Abstract: Survival of eggs of chum salmon Oncorhynchus keta was determined at Carnation Creek, British Columbia, with two devices that were designed to help assess factors influencing incubation and to cause minimum disturbance of natural stream gravels. Three variations of the incubation technique were assessed with perforated plastic cylinders (incubation capsules). Survival rates of 0–47% were obtained when (1) water exchange through the capsules was adequate, (2) egg density was limited to 30 eggs/capsule, (3) eggs were distributed throughout the capsules, and (4) eggs were planted within 1 h of fertilization. Variation in survival was partially attributed to differences among stations in salinity, substrate composition, and dissolved oxygen concentrations. The technique was simple and inexpensive, so many replicates could be used. A capped and inverted plastic pipe (intragravel fry releaser) was developed to introduce alevins into the streambed. From 0 to 69% of them emerged. No differences in timing ...
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TL;DR: The results indicate that Kupffer cells clear bacterial endotoxin in vitro and post‐uptake degradation occurs within 20 hr of incubation, inconsistent with a receptor‐mediated process as previously suggested.
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TL;DR: A model is presented indicating where developing eggs and larvae are likely to be found in the natural water column, a model that also could lead to the provision of oxygen requirements during the planktonic drift stages of egg and early larval development.
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TL;DR: A combined effect of water activity and temperature on the zearalenone accumulation was observed and it was found that at short incubation times, toxin accumulation was greater at water activity 0.97 than at waterActivity 0.95 (25 degrees C).
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TL;DR: A Metaseiulus occidentalis bioassay procedure that approaches incubation conditions for maximum host susceptibility to Serratia marcescens is presented and shows that although some of the stress factors significantly affected fecundity, measured by egg production rate, inoculation with S. marcascens at doses up to 10 8 colony-forming units/ml did not.