Showing papers on "Incubation published in 1979"
TL;DR: Escherichia coli cells are 4--6 times more transformable and 20--30 times more competent after 24 h incubation in cold calcium chloride than immediately after calcium chloride treatment.
1,354 citations
TL;DR: It is demonstrated that lipid synthesis from glucose is also enhanced over a narrow range of H2O2 concentrations (0.15 to 0.5 mM) added to the incubation medium, and these findings add to the growing list of insulin effects that are reproduced by H 2O2, and strengthen the hypothesis that assigns H2 O2 the role of "second messenger" of insulin.
194 citations
TL;DR: Eggs of Chelydra serpentina were shifted during incubation between the female producing temperatures of 20°C or 30°C and the male producing temperature of 26°C, and the stages during which incubation temperature determined sex were stage 14 through stage 16.
Abstract: Eggs of Chelydra serpentina were shifted during incubation between the female producing temperatures of 20°C or 30°C and the male producing temperature of 26°C. In the 20°C and 26°C combination, the stages during which incubation temperature determined sex were stage 14 through stage 16 (stages of normal series, Yntema, '68). In the 30°C and 26°C combination, the temperature sensitive stages for sex determination were stage 14 through stage 19. Incubation at 26°C throughout this period was needed to produce all males. Incubation at 30°C during either the first or second half of the period produced nearly all females; shorter periods of incubation at 30°C were more effective in producing females during the second half of the sensitive period. In the 20°C and 26°C combination, incubation at 20°C or 26°C for parts of the sensitive period produced both males and females. In three of the 57 clutches of eggs used in the experiments, incidence of females was atypically high.
155 citations
Journal Article•
TL;DR: The evidence indicates that C3e is a fragment of C3 with biologic activity distinct from that of other C3 fragments that arises from cleavage of the portion of the α-chain that is part of the C3c fragment.
Abstract: We have isolated a leukocytosis-inducing peptide of degraded human C3 that has the electrophoretic behavior of prealbumin and a m.w. of 10,000 to 12,000. The peptide has been designated C3e. It was generated by two methods: Incubation of isolated C3 with 2% (w/w) trypsin for 120 min at 37°C, or incubation of serum at 37°C for 5 days under sterile conditions. C3e preparations obtained by the two methods were virtually indistinguishable with respect to molecular size, amino acid composition, and immunochemical properties. The electrophoretic mobility of C3e at pH 8.6 is -7.5 × 10 -5 cm 2 V -1 sec -1 . Anti-C3e reacts with C3e, C3, C3b, and C3c, but not with C3a or C3d. Since the β-chain of C3 is not affected by the liberation of C3e, it is concluded that C3e arises from cleavage of the portion of the α-chain that is part of the C3c fragment. Purified C3e was found to mobilize leukocytes from bone marrow upon perfusion of isolated rat femur. Intravenous injection of C3e into rabbits caused a 2- to 3-fold increase in the number of circulating leukocytes after 60 min which lasted 2 hr. Leukocytosis was preceded by mild leukopenia. Leukocytosis-inducing activity was abrogated by treating C3e preparations with solid phase anti-C3. Incubation of heparinized rabbit blood with radioiodinated C3e resulted in preferential binding of C3e to polymorphonuclear leukocytes. Intradermal injection of C3e into rabbits evoked increased vascular permeability after 15 to 30 min. The evidence indicates that C3e is a fragment of C3 with biologic activity distinct from that of other C3 fragments.
101 citations
TL;DR: In this article, the authors described desorption in terms of two limiting values: the amount of phosphate (K) which would be desorbed as the concentration of phosphate approached zero, and the solution concentration of Co at which no re-adversarial occurred.
Abstract: Summary
After incubation with soil, phosphate was desorbed in dilute calcium chloride solutions. After short periods of incubation, the amount of phosphate desorbed increased rapidly at first but then net re-adsorption occurred. After long periods of incubation, desorption was slower and there was no net re-adsorption with prolonged desorption.
Desorption was described in terms of two limiting values: the amount of phosphate (K) which would be desorbed as the concentration of phosphate approached zero, and the solution concentration of phosphate (Co) at which no desorption occurred. Both values decreased as the period of incubation increased. The value of K increased during the desorption phase, but the value of Co decreased. The decrease in Co during desorption was most marked after short periods of incubation and was important in describing the trend for re-adsorption of phosphate.
99 citations
TL;DR: The observations indicate that there are several options for the localization of catalase depending on the fixation and incubation conditions, and these conditions should be selected according to the tissue and the purpose of the study.
Abstract: The influence of various parameters of fixation and incubation upon the oxidation of DAB by catalase have been analyzed. Crystalline beef liver catalase was fixed with different concentrations of glutaraldehyde and peroxidatic activity was determined spectrophotometrically using DAB as hydrogen donor. Although aldehyde fixation appeared to be important in elicitation of the peroxidatic activity of catalase, the final pigment production after 60 min incubation was optimal with the lowest concentration of glutaraldehyde (1%), after the shortest fixation period (30 min), and at the lowest temperature (5° C) tested. Similarly cytochemical studies with rat kidney sections incubated for 10 min confirmed that the staining of peroxisomes in proximal tubules was strongest after the “mildest” fixation conditions. The pH and the temperature of incubation were closely interrelated, so that at room temperature (25° C) the maximal pigment production was obtained at pH 10.5 but incubation at 45° C gave the strongest staining at pH 8.5. The production of pigment increased with higher DAB concentrations which required larger amounts of H2O2 in the incubation medium. Cytochemical studies on renal peroxisomes were in agreement with these biochemical findings. The observations indicate that there are several options for the localization of catalase depending on the fixation and incubation conditions. Hence, these conditions should be selected according to the tissue and the purpose of the study. Examples for such selective applications are presented.
75 citations
TL;DR: It was calculated that during 4-9 days of incubation a single trophozoite phagocytized and killed a daily average of 84 yeast cells; some of the surviving cells of C. neoformans developed into colonies containing pseudohyphae; these pseudolhyphal forms may be a biological 'escape hatch'.
Abstract: During 7 days of incubation in vitro the trophozoite stage of the free-living soil amoeba, Acanthamoeba polyphaga, phagocytized and killed 78–97% of the cells of three strains of Cryptococus neoformans. With one strain, incubation time was increased to nine days and 99% of the yeast cells were killed. It was calculated that during 4–9 days of incubation a single trophozoite phagocytized and killed a daily average of 84 yeast cells. The lethal effect of A. polyphaga on C. neoformans may represent a biological control mechanism in nature. Some of the surviving cells of C. neoformans developed into colonies containing pseudohyphae; these pseudolhyphal forms may be a biological ‘escape hatch’.
73 citations
TL;DR: The data indicate that the accessibility of hormone‐binding components at the plasma membrane may contribute to the capacity of a given liver cell to respond to E2β, as well as to other known hepatocarcinogens.
Abstract: Hepatocytes were isolated by established procedures from freshly-excised livers of ovariectomized rats. Integrity of the cells was verified by DNA, protein, and calcium contents, and by dye exclusion. The cells also showed progressive increments in oxidation to 14CO2 of [26-14C]cholesterol during one to five hours' incubation. Analysis was undertaken of cellular reactivities toward estrogen and the hepatocarcinogen dibutylnitrosamine (DBN). Binding and retention of [3H]estradiol-17β (E2β) by isolated liver cells was specific for E2β, saturable, temperature-dependent, and maximal after 30-minute incubation. The apparent dissociation constant for the binding process at 22°C is 2 × 10−9 M, and the total number of binding-sites at saturation corresponds to approximately 3,400 E2β molecules per liver cell. To probe for steroid binding-sites at their external surfaces, cells were incubated 30 minutes with mounted 17β-estradiol-17-hemisuccinyl:albumin:nylon fibers. The covalentlyimmobilized estrogen (1 ng/mg albumin) was accessible for interaction with antiserum directed against 17β-estradiol-17-hemisuccinyl:albumin. Significant numbers of isolated liver cells were retained by estrogen-derivatized fibers at 22°C after extensive washes. Binding was markedly reduced by incubation at 4°C and by prior exposure to free E2β (× 10−8 M), but not to the relatively inert estradiol-17α (E2α). Fiber-bound cells could be dislodged by brief incubation in 150 mOsM saline with 2 × 10−7 M E2β or diethylstilbestrol, but not E2α, cortisol, progesterone, or testosterone, and recovered intact. Cells that had been retained by the fibers and those that were not adherent were collected and washed under identical conditions, then plated in serum-free, chemically-defined medium at 37°C. After 72 hours, specific binding of E2β by the fiber-binding cells during 30 minutes' incubation was 2.5-fold that of cells which had not bound the immobilized steroid. Similarly, stimulation of the oxidation to 14CO2 of [26-14C]cholesterol by E2β was greater in fiber-binding than in non-binding liver cells after three hours' incubation. In the absence of added mitogen, thymidine incorporation into macromolecular form (20 hours), and cell proliferation (48 hours) were significantly greater in fiber-binding cells as compared to non-binding hepatocytes. Moreover, in parallel experiments, when cells were exposed to 1 × 10−9 M estrogens or to 1 × 10−4 M nitrosamines to assess the capacities of these substances to increase basal thymidine incorporation, total DNA, and cell numbers, only those cells with estrogen-binding sites at their surfaces showed significant E2β- and DBN-induced increments in these parameters as compared with paired controls that had been treated with E2α or the noncarcinogen diphenylnitrosamine. These data indicate that the accessibility of hormone-binding components at the plasma membrane may contribute to the capacity of a given liver cell to respond to E2β, as well as to other known hepatocarcinogens.
71 citations
TL;DR: The plasma concentration of prolactin was measured following experimental photostimulation, during oviposition and during incubation in plasma from ruffed grouse by heterologous double-antibody radioimmunoassay to identify hens that failed to incubate.
Abstract: The plasma concentration of prolactin was measured following experimental photostimulation, during oviposition and during incubation in plasma from ruffed grouse by heterologous double-antibody radioimmunoassay. A slight increase in plasma prolactin was noted after photo-stimulation and a much larger increase was observed as subsequent eggs were laid. When the last egg was laid, plasma prolactin was maximal. This high concentration was maintained throughout incubation and declined to basal values when incubation was terminated by removal of the eggs. In hens that failed to incubate, plasma prolactin declined after the last oviposition.Brood patch development began before the first egg was laid but was not completed until incubation was initiated. Therefore, the patch began to develop when plasma concentrations of prolactin were slightly elevated but it was not fully formed until high concentrations of prolactin were maintained for several days.
68 citations
TL;DR: Resistance might be correlated with increased excretion of fungal metabolites, which in turn may be related with reduced fitness of fenarimol-resistant mutants.
55 citations
TL;DR: It is suggested that GH secretion in teleosts may be influenced by a somatostatin-like peptide which acts to suppress the release of GH from the pituitary.
TL;DR: The potassium level in mouse mastocytoma P815 cells undergoes a 40% reduction within 30 minutes of incubation at 43°C, but the net loss of cations from the cells undergoing hyperthermia does not induce a simultaneous reduction of intracellular water volume.
TL;DR: The viral-induced changes in the granulocyte response to isoproterenol may reflect similar alteration in other tissues, such as variable control of the airways and provide one explanation for the occurrence of airway dysfunction during respiratory infections.
Abstract: The release of the lysosomal enzyme beta-glucuronidase from granulocytes follows incubation in vitro with complement-activated zymosan particles. Release of beta-glucuronidase is inhibited by isopr...
01 Dec 1979-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: Cirolana borealis is adapted to maintain a high ATP output per unit time, which suits the high energy demand under natural anaerobic conditions, and shows a marked Pasteur effect.
Abstract: 1.
Cirolana borealis utilises glycogen during anaerobiosis and shows a marked Pasteur effect. In 18h, 20–30 mg/g dry weight were converted, about half of the initial total glycogen content (Table 1).
2.
Lactate is the major end product, while succinate and alanine are minor end products. 27–52% of the lactate produced was excreted into the incubation water (Tables 2 and 3). A good stoichiometric relationship was obtained between the glycogen consumed and the accumulation of these end products.
3.
Small amounts of glutamate and aspartate contribute to the carbon flow, which could be of significance for obtaining redox balance (Table 3).
4.
ATP production during anoxia was 75% of that during the standard aerobic state.
5.
It is concluded that anaerobic fermentative metabolism ofC. borealis is adapted to maintain a high ATP output per unit time, which suits the high energy demand under natural anaerobic conditions.
6.
WhenC. borealis are subjected to experimental anoxia they expel their gut contents and the incubation water becomes enriched with acetate, propionate, and amino acids. Most of these compounds probably stem directly from the gut content, while some, like acetate, may be produced by microbial activity. Starvation and anaerobic preincubation resulted in a marked lowering of the amounts of these compounds in the incubation water.
01 Jan 1979
TL;DR: The temperature recorded during the period of steady incubation was 36.4?C and the duration of attentiveness was adjusted to changes in the air temperature, but the male's visits to the nest interfered with and partly masked this pattern.
Abstract: temperature recorded during the period of steady incubation was 36.4?C. The duration of attentiveness was adjusted to changes in the air temperature. With increasing air temperature the periods-on tended to decrease and the periods-off to increase in duration, but the male's visits to the nest interfered with and partly masked this pattern. There is some evidence that incubation is basically controlled by a circadian rhythm.
TL;DR: Investigation of rumen volatile fatty acids, lactate concentrations and pH over periods which included regular feeding and 48 h starvation resulted in a marked decrease in salmonella numbers, while lower VFA concentrations had little or no inhibitory effect on growth.
TL;DR: The age of eggs is one factor which must be considered when conductance of eggs of conspecific populations is compared between habitats or over altitudinal gradients.
Abstract: In contrast to previously published observations of constant daily water loss during incubation in some large, precocial eggs, daily rates of water loss increase approximately 42% between days 1–4 in redwinged blackbird eggs and conductance to water vapor increases 47 and 48% during the early stages of incubation in red-winged blackbird and robin eggs, respectively. Therefore, the age of eggs is one factor which must be considered when conductance of eggs of conspecific populations is compared between habitats or over altitudinal gradients.
TL;DR: The presence of high levels of T3 in serum, in chick embryos after perforation of the air space membrane, and the sharp increase in ratio before the event of “pipping”, appear to suggest that T3 has an important role in the processes of ”pipping" and hatching.
TL;DR: The data show clearly that the percentage of lipid in the combined yolk and albumen does not alter significantly during incubation, so the results should not be biased by the degree of incubation when the results are expressed on a lipid-weight basis.
Abstract: Literature citations of organochlorine residue levels of environmental samples are expressed on a wet-weight, dry-weight or lipid-weight basis; however, there appears to be an increasing trend to express the results on a lipid-weight basis. The eggs of birds have been used widely to assess levels of organochlorine pollutants accumulated in the wild and through experimental exposure. In this note the limitations of expressing the results of analysis of eggs on a lipid-weight basis are discussed. PREVOST and MORIN (1846) first noted the presence of lipid in the avian egg and its importance as a source of energy for the embryo was discussed by PARKE (1877). Later, ROMANOFF (1932), determined the extent of utilization of lipid by chicken embryos during incubation. The importance of the changes in lipid content during incubation from the point-of-view of residue analysis was raised by STICKEL et al. (1973) but they did not discuss this point in detail and their caution seems largely to have been ignored. In the course of our work on the effects of pollutants on the reproduction of the Herring Gull (Larus argentatus) we made measurements of the organochlorine levels in the combined yolk and albumen and in the developing embryo at various states of natural incubation (GILMAN et al. 1978). Since both the lipid and the water content were measured it was possible to use these data to illustrate the lipid and water levels in these two components of the egg at various stages of incubation (Table I). Additional data from eggs collected before incubation had commenced and at the stage when the first cracking of the shell occurred prior to the hatching (GILMAN 1978) are also shown in Table i. The data show clearly that the percentage of lipid in the combined yolk and albumen does not alter significantly during incubation. Thus if traces of yolk and albumen are extracted from shell fragments of broken eggs (cf Brown Pelican, Pelecanus occidentalis, eggs from Anacapa, RISEBROUGH 1972) or extracts from blown eggs are used (cf Peregrines, Falco peregrinus, PEAKALL 1974), the results should not be biased by the degree of incubation when the results are expressed on a lipid weight
Journal Article•
TL;DR: Although DES was as effective as E2, U11,100A and estrone were inefficient competitors and it appeared that the levels of these two estrogen analogues required to maximally displace [3H]E2 on receptor also eluted labeled E2 from the dextran-coated charcoal.
TL;DR: The Superb Lyrebird (Menura superba) inhabits mainly wet sclerophyll and temperate rainforest in southeastern Australia and both incubation and broodcare are uniparental.
Abstract: The optimal temperature range for avian embryos and nestlings is usually narrow. Slight deviations from this range can retard growth, and, if prolonged, induce abnormal development and mortality (Lundy 1969). Incubation and brooding rhythms generally restrict significant temperature deviations even during periods of inattention (Huggins 1941), and parents can also adjust levels of heat transfer during contact with eggs and nestlings (Drent 1973). Most species breeding at low temperatures maintain fairly constant egg and early nestling temperatures through a high level of nest attentiveness, even when incubation and brooding are uniparental (White and Kinney 1974). The Superb Lyrebird (Menura superba) inhabits mainly wet sclerophyll and temperate rainforest in southeastern Australia. Its domed nest is built at varying heights from ground level to 18 m. The single-egg clutch is laid in mid-winter and hatches in late winter or early spring. Daytime ambient temperatures are around 10'C or lower during the incubation and early nestling periods, and both incubation and broodcare are uniparental (Lill, unpubl. data). Tregallas (1921), Ward (1940) and Reilly (1970) have suggested that lyrebird incubation does not begin immediately after egg-laying despite the prevailing low temperatures. Ward (1939), Reilly (1970) and Robinson (1977 and unpubl. data) also indicate that the egg may be deserted for a long period daily once incubation has commenced. Since the six to seven week incu-
TL;DR: Isolated rat hepatocytes were aerobically incubated in absence or in presence of 2 mM bromotrichloromethane (CBrCl3) and an increase in malondialdehyde (MDA) formation of the cells was observable in both the C BrCl3-containing and the CBrCl 3-free incubation mixtures.
Abstract: Isolated rat hepatocytes were aerobically incubated in absence or in presence of 2 mM bromotrichloromethane (CBrCl3). Viability criteria, such as trypan blue uptake and lactate dehydrogenase release of the cells increased with incubation time in both systems. An increase in malondialdehyde (MDA) formation of the cells was observable in both the CBrCl3-containing and the CBrCl3-free incubation mixtures.
Journal Article•
TL;DR: The effect of GLT on target cells (L.P3 cells) labeled with radioactive fatty acids was examined and the survival ratio was decreased with a concomitant increase of the radioactivity of triglyceride of the target cells and enhancement of calcium uptake into thetarget cells.
Abstract: The effect of GLT on target cells (L·P3 cells) labeled with radioactive fatty acids was examined. After incubation for 1 or 2 hr, no change in the survival ratio was observed, but radioactive fatty acid was released from phospholipids of the cells. When incubation was continued for 4 or 5 hr, the survival ratio was decreased with a concomitant increase of the radioactivity of triglyceride of the target cells and enhancement of calcium uptake into the target cells. These results could be explained by activation of membrane-bound phospholipase A after the binding of GLT to cell surface receptors.
TL;DR: The results from one male and one female support the idea that incubation can be accomplished at the level of adult resting metabolism, and that in the last 5 days of the incubation period a clutch of five eggs contributes 19–25% of the total heat required for incubation.
TL;DR: Incubation of dopamine-4-O-sulfate with purified bovine dopamine-beta-hydroxylase led to the formation of free norepinephrine and production of fusaric acid was completely inhibited in the presence of 5.6 mM.
Abstract: Incubation of dopamine-4-O-sulfate with purified bovine dopamine-β-hydroxylase led to the formation of free norepinephrine. The production of free norepinephrine was completely inhibited in the presence of 5.6 mM of fusaric acid, an inhibitor of dopamine-β-hydroxylase. No sulfatase activity was detected in the incubation medium. The reaction of dopamine-4-O- suifate with dopamines-β-hydroxylase followed Michaelis–Menten kinetics, showing an apparent Km of 2.6 mM.
TL;DR: It is proposed that lutropin affects the stability of a precursor of a regulator protein by converting it from a stable (inactive) to an unstable (active) form with a short half-life.
Abstract: The dependence on lutropin of the synthesis of a proposed short-half-life protein regulator involved in Leydig-cell steroidogenesis was investigated This was carried out by determining the effect of the protein-synthesis inhibitor cycloheximide, added before and during incubations with lutropin (and/or dibutyryl cyclic AMP), on the rate of testosterone production in suspensions of purified Leydig cells from adult rat testes The Leydig cells were preincubated in Eagle's medium for 25h followed by 30min incubation with and without cycloheximide The inhibitor was removed by washing the cells and then lutropin was added and testosterone concentrations were determined after incubation of the cells at 32 degrees C No significant effect of cycloheximide pretreatment on lutropin-stimulated steroidogenesis was found during 60min incubation This was in contrast with the complete inhibiting effect of cycloheximide when it was added with the lutropin The pretreatment experiments with cycloheximide were repeated in the presence of dibutyryl cyclic AMP and elipten phosphate (to inhibit cholesterol side-chain cleavage) followed by incubation with lutropin After 5, 10, 20 and 60min of incubation, testosterone concentrations were 61+/-3, 46+/-3, 27+/-4 and 18+/-4% lower than in the cells pretreated without cycloheximide respectively (means+/-sem, n=4-6) In the cells not pretreated with cycloheximide and in the absence of lutropin, testosterone production increased from 136+/-05 to 365+/-10ng/10(6) cells during 20min of incubation, after which no further increase occurred Pretreatment of the cells with cycloheximide decreased these testosterone concentrations by 65, 46, 42 and 36% in the 5, 10, 20 and 60min incubations respectively (mean values, n=2-4) It is apparent from these results that inhibition of steroidogenesis only occurs if protein synthesis is inhibited in the presence of lutropin or cyclic AMP A new hypothesis is put forward to explain these findings: it is proposed that lutropin affects the stability of a precursor of a regulator protein by converting it from a stable (inactive) to an unstable (active) form with a short half-life
TL;DR: Respiration (O), ammonium (NH,), phosphate (PO,), total nitrogen (NT) and phosphorus (P,) excretions were measured on mixed zooplankton during 3, 6, 9, 12, 21, and 24-h incubation periods at 20-23°C.
TL;DR: The decline in cholesterol 7 alpha-hydroxylase activity was observed whether cholestyramine was included in the diet or excluded from the diet of the animals used as sources of the liver cells, and this suggests that some protein synthesis associated with cholesterol 7alpha-hydrogenase activity occurs during the incubation and inhibition of such protein synthesis accelerated the decrease in this enzyme activity.
Abstract: 1. The activity of cholesterol 7 alpha-hydroxylase found in the 10000 x g supernatant prepared from isolated rat liver cells was comparable to that found with microsomal fractions from whole liver. 2. The activity of cholesterol 7 alpha-hydroxylase from cells prepared from livers of rats fed the bile salt sequestering agent cholestyramine was 2--3 fold higher than the activity of this enzyme found in cells isolated from animals on a control diet. 3. On incubation of hepatocytes in a suitable medium at 37 degrees C, cholesterol 7 alpha-hydroxylase activity declined to about 50% of its original value after three hours despite the fact that the cells retained a high level of viability over 5--6 h as measured by various sensitive criteria. 4. The decrease in cholesterol 7 alpha-hydroxylase activity was observed whether cholestyramine was included in the diet or excluded from the diet of the animals used as sources of the liver cells. 5. The change in cholesterol 7 alpha-hydroxylase activity seen on incubation of the cells was not affected by including in the incubation medium additional nutrients such as amino acids, the glucocorticoid cortisol, phospholipid dispersions, or sodium taurocholate. 6. Changing the incubation medium in which the cells were suspended at regular intervals during the three-hour experiments failed to prevent this decline in the cholesterol 7 alpha-hydroxylase activity during the incubation of these cells. 7. Although isolated liver cells have been shown to lose glutathione on incubation, addition of physiological levels of this compound did not prevent the decline in cholesterol 7 alpha-hydroxylase activity. 8. Cycloheximide addition to the incubation medium accelerated the decrease in cholesterol 7 alpha-hydroxylase activity. This suggests that some protein synthesis associated with cholesterol 7 alpha-hydroxylase activity occurs during the incubation and inhibition of such protein synthesis accelerated the decrease in this enzyme activity. 9. The cytochrome P-450 content of the 10000 x g supernatant prepared from hepatocytes declined slowly to about 65% of its original value after four hours of incubation at 37 degrees C. This decline in the 10000 x g supernatant cytochrome P-450 content may partly explain the observed loss of cholesterol 7 alpha-hydroxylase activity during incubations in vitro. 10. Isolated hepatocytes rapidly take up radioactively labelled sodium cholate. Subsequent excretion of the radioactivity was also very rapid even in the presence of large amounts of this bile salt in the medium.
TL;DR: In this article, the stability of topsoil samples of six British soils (Hanslope, Ragdale, Evesham, Denchworth, Flint and Salop) were incubated with added nutrients and changes in their stability to wet sieving determined.
Abstract: Summary
Natural aggregates of topsoil samples of six British soils (Hanslope, Ragdale, Evesham, Denchworth, Flint and Salop) were incubated with added nutrients and changes in their stability to wet sieving determined. Under anaerobic incubation the type of nutrient added had little effect on stability. Aerobic incubation with glucose gave a larger proportion of stable aggregates than with water. With peptone stability usually decreased, and occasionally increased, which may indicate differences in the binding mechanisms of the soil particles. Both sterile and unsterile aggregates incubated with water became more stable than controls; the rapidity of this change suggested a physical, rather than microbiological cause. Very stable grassland aggregates changed little on aerobic incubation with water, but became more stable with solutions of glucose or peptone. Artificial aggregates made from the same soil developed considerable stability to water on aerobic incubation, but remained almost totally unstable when incubated anaerobically.
TL;DR: It was concluded that incubation with cations and processing at room temperature were prerequisites of optimal preservation of synaptosomal microtubules.
Abstract: A time-dependent rise in the percentage of microtubule-containing synaptosomes was observed reaching a 41–47% peak after 30 min incubation at room temperature (22–25 ° C) in a saline medium. Fixation at low temperature or incubation with vinblastine decreased markedly the number of synaptosomes containing microtubules. It was concluded that incubation with cations and processing at room temperature were prerequisites of optimal preservation of synaptosomal microtubules. Their spatial orientation relative to the synaptic cleft was deduced from statistical examination of profiles in different orientations.