Showing papers on "Incubation published in 1982"
TL;DR: Blood samples were collected from male and female free-living starlings in every month during the year and at all stages of the breeding cycle for prolactin, LH, and FSH to show a pronounced unimodal cycle in both sexes.
143 citations
TL;DR: The eggs of some birds take much longer to hatch than expected, and highly variable and long incubation periods are explained using fork-tailed storm petrels as an example.
Abstract: In general, incubation periods of bird eggs are positively correlated with egg weights. The eggs of some birds take much longer to hatch than expected. Highly variable and long incubation periods are explained using fork-tailed storm petrels as an example. Their eggs take two to three times as long to hatch as eggs of similar size. Egg neglect causes the extreme variability in incubation periods within a species. Low incubation temperatures prolong incubation, but long incubation periods may also be a result of selective forces that favor hatching well-developed young that can be attended infrequently. Past terminology has obscured the importance of the relationship between incubation periods and the maturity of chicks at hatching. Selection has produced a continuum between cheap eggs and expensive care for the relatively helpless (altricial) young or expensive eggs and inexpensive care for the relatively independent (precocial) young. The distant foraging habits of the Procellariiformes have favored inde...
95 citations
TL;DR: In this article, the effect of soil pH on the rate and products of denitrification, a silt loam soil (Typic Arguidoll) was used that had been collected from a field experiment maintained at various pH levels for 18 years.
Abstract: To examine the effect of soil pH on the rate and products of denitrification, a silt loam soil (Typic Arguidoll) was used that had been collected from a field experiment maintained at various pH levels for 18 years. The soil pH ranged from 4.6 to 6.9 and was nearly uniform in organic C (1.15 +/- 0.05%) and texture. Incubation was performed under He in all-glass systems that were sealed throughout the incubation period. The soils were amended with 100 ..mu..g/g of NO/sub 3//sup -/-N before incubation. Denitrification products (N/sub 2/O, NO, and N/sub 2/) and CO/sub 2/ were determined by gas chromatography using an ultrasonic detector. It appears that the rate of organic C mineralization rather than pH controls the rate of denitrification in C-limited systems. At 100 ..mu..g NO/sub 3//sup -/-N added per gram of soil, the overall rates of denitrification correlated with the rates of C mineralization (CO/sub 2/ evolution) but were not consistently related to pH or to total organic C. Soil pH did affect the products of denitrification. Nitrous oxide comprised 83% of the gaseous-N products for pH 4.6 and 5.4 when 90% of the NO/sub 3//sup -/ had been denitrified. The N/sub 2/O was thenmore » rapidly reduced to N/sub 2/. The highest amount of NO was observed at pH 4.6 and 5.4. At pH 6.0 the rate of production of N/sub 2/O exceeded the rate of reduction only for the first 2 d of incubation. However, N/sub 2/O was the dominant product until approx.83% of the NO/sub 3//sup -/ had been denitrified. At pH 6.9, N/sub 2/ was the dominant product after the 1st d of incubation. 21 references, 1 figure, 2 tables.« less
94 citations
TL;DR: Results show that mutagenic factors, generated during cooking of pork and bacon, are ingested and absorbed and are subject to urinary clearance in biologically detectable quantities.
87 citations
TL;DR: The results show that scrapie infectivity decreases with extended incubation of scrapie-exposed macrophages, and the data suggest that macrophage can inactivate the scrapie agent in vitro.
Abstract: Mouse peritoneal macrophages were exposed to scrapie (ME7 strain) brain homogenate in vitro for 2 h at 37c. The samples were assayed for infectivity by analysis of scrapie incubation periods and their values compared to those obtained after extended (1–28 days) in vitro incubation. The scrapie incubation periods for scrapie agent-macrophage mixtures which had undergone extended in vitro incubation were longer than for mixtures assayed after a 2-hour exposure to the scrapie agent. The difference in scrapie incubation periods was more drEmatic when residual scrapie was eliminated by washing the cells after the 2-hour exposure to brain homogenate. The scrapie incubation period also increased following in vitro incubation of ME7 in the absence of cells; however, the changes were less than those observed for scrapie agent-macrophage mixtures. In a culture in which cells had been destroyed by UV irradiation after exposure to the scrapie agent, there was more scrapie infectivity than in a comparable culture of untreated, scrapie-Exposed macrophages. These results show that scrapie infectivity decreases with extended incubation of scrapie-exposed macrophages, and the data suggest that macrophages can inactivate the scrapie agent in vitro.
80 citations
TL;DR: Observations support the view that in the hen, an increase in the secretion of prolactin plays a key role in the induction of incubation behaviour and a nocturnal increase in prolACTin secretion may be involved in the maintenance of brooding behaviour.
70 citations
TL;DR: Investigations of proteolysis during anaerobic cocoa seed incubation have been extended by disc and SDS-gel electrophoretic protein analysis and two protein bands were found to be vacuolar storage proteins, which accumulated during seed ripening and which were specifically utilised during germination.
Abstract: Investigations of proteolysis during anaerobic cocoa seed incubation have been extended by disc and SDS-gel electrophoretic protein analysis. Two protein bands (2.6 × 104 and 4.4 × 104 Dalton) were found to be vacuolar storage proteins, which accumulated during seed ripening (90 to 160 days after pollination) and which were specifically utilised during germination. Although the storage proteins are poorly soluble at pH 3.5–4.5, proteolysis during incubation of acetone dry powders is highest in this pH range. All proteins are digested at 50°C, pH 4.5. During seed incubation at 50°C, pH 4.5, however, the storage proteins are degraded preferentially although the cells are dead at 50°C. This degradation is increased by preincubation at 40°C instead of 50°C. The results are discussed in the light of structural peculiarities in the seed tissue and the possible role of specific endopeptidases and peptides in the formation of flavour precursors during fermentation.
58 citations
TL;DR: By calculating the carapace/ovary length ratio of a female approaching pre-spawning moult, the number of eggs to be incubated is predicted and imbibition of water and the consequent volumetric expansion of eggs, abrasion of eggs during the ventilatory movements of the pleopods, and erosion of individual territories are considered.
56 citations
TL;DR: The results show that prolactin secretion is high not only during incubation but also during the parental feeding phase in an altricial passerine bird.
Abstract: Concentrations of prolactin were measured in the plasma of male and female canaries serially sampled during repeated breeding cycles. Concentrations in female canaries were low during nest building and increased significantly (P less than 0.05) during the first few days of incubation. Levels increased further (P less than 0.01) in the middle of the incubation period to reach concentrations which were ten times higher than before breeding. Levels remained high for several days after the eggs hatched, as the young were fed in the nest. Prolactin concentrations declined gradually as the young were reared, reaching basal levels by the time the young were fledged, but always increased again in the females as they began incubating eggs in subsequent breeding cycles. Male canaries, which do not incubate but do assist in feeding the young, showed only slight increases in prolactin during the parental period. Male and female canaries which did not breed had low levels of prolactin throughout the experiment. The results show that prolactin secretion is high not only during incubation but also during the parental feeding phase in an altricial passerine bird. These findings are discussed in relation to the different patterns of prolactin secretion which occur during breeding in other birds.
56 citations
TL;DR: Proteolysis in cocoa seeds was studied by fermentation-like anaerobic incubation to determine whether post-mortem proteolysis depends only on temperature and acidity as mentioned in this paper, which is not dependent on microorganisms, on exudation or on interaction of proteins and polyhydroxyphenols.
Abstract: Proteolysis in cocoa seeds was studied by fermentation-like anaerobic incubation to determine whether post-mortem proteolysis depends only on temperature and acidity. In acetone dry powder incubation, autolytic release of α-amino nitrogen is optimal at pH 4.0-4.5 and is higher at 55°C than at 45°C. Proteolysis increases with acidification. However, in seed and seed fragment incubation, acetic acid is more effective than citric acid under similar conditions. Further, a first incubation at a low temperature (40°C) in contrast to a high temperature (50°C) favours post-mortem proteolysis during a subsequent incubation of cotyledon tissue at 50°C in an acetic solution, whereas it does not with cotyledon dry powder in the same solution. This effect of pre-incubation temperature in seeds is diminished in the presence of a high concentration of acetic acid. It does not depend on microorganisms, on exudation or on interaction of proteins and polyhydroxyphenols. Since increased proteolysis after incubation at 40°C correlates with structural changes in protein vacuoles and with water uptake by the intact seeds, a causal relationship is indicated.
54 citations
TL;DR: Under the incubation conditions of the opioid receptor binding assay, dynorphin-(1–13) is metabolized by membrane-bound exopeptidases which cleave the NH2-terminal tyrosine and the COOH- terminate of the peptide.
TL;DR: It was concluded that gaseous conductance of some turkey eggshells is insufficient to meet embryonic demands late in incubation.
TL;DR: It is suggested that small endogenous nutrient reserves and the low density of invertebrate foods, typical of Black Duck breeding habitat, were critical factors affecting the evolution of Black Ducks incubation behavior.
Abstract: --Incubation rhythms and brood attentiveness of radio-marked Black Ducks (Anas rubripes) were studied in southcentral Maine during 1977-1980. Recess duration and frequency differed between three females nesting near wetlands (x = 82 min, 2.3 recesses/day) and two nesting at upland sites (x = 183 min, 1.1 recesses/day), but incubation constancy was similar for all birds (x = 86.7%). A fourth wetland-nesting female apparently responded to the absence of down and concealing cover at the nest site by taking shorter and fewer recesses (x = 34 min, 1.0 recesses/day) than did other wetland-nesters with typical nests. Wetland-nesters took longer recesses with increasing air temperature and following long incubation sessions. After their ducklings were two weeks old, two broodrearing females began leaving their broods to forage on nearby wetlands. Duration of rearing recess (x = 56 min) and total recess time (x = 94 min/day) were less during this mid-rearing stage than during the latter part of rearing (x = 265 min, 488 min/day). The two hen-brood bonds terminated at 43 and 48 days. We suggest that small endogenous nutrient reserves and the low density of invertebrate foods, typical of Black Duck breeding habitat, were critical factors affecting the evolution of Black Duck incubation behavior. Bouts of inattention during brood rearing may have also evolved in relation to food requirements; by foraging on wetlands away from their broods, females avoid competing with offspring for common food resources. The behavior of female anatids during incubation and brood-rearing reflects the energetic demands of the reproductive season. High incubation constancy is typical of geese (Ryder 1970, MacInnes et al. 1974, Ankney and MacInnes 1978) and Common Eiders (Somateria mollissima; Korschgen 1977), which depend on stored nutrient reserves during this period. The females of smaller anatids are unable to store large endogenous reserves and, therefore, depend on environmental food resources to meet most of their metabolic requirements during incubation (Afton 1979). Because food is obtained during incubation recesses, recess duration and frequency may be related to metabolic reserves (Afton 1978), feeding efficiency (McKinney 1970), and density and availability of food resources. Incubation rhythms and brood attentiveness of female Black Ducks (Anas rubripes) have not been quantified. Mendall (1958:96) stated that "Black Ducks normally have only two rest periods per day, one in the early morning and another in late afternoon." He estimated the duration of incubation recesses at 60 min. Coulter and Miller (1968:20) concluded that "there was no period of the day when the majority of hens were off their nests." After hatching, female dabbling ducks usually remain with their broods until the ducklings are seven to eight weeks old (Munro 1949, Evans et al. 1952), although the duration of the hen-brood bond differs among species (Beard 1964, Ball et al. 1975). Before this time, hens leave their ducklings for periods ranging from 15-75 min (Beard 1964) to several hours or all day (Mendall 1958:126, Ball et al. 1975). We describe here the schedule of nest and brood attentiveness of radio-marked Black Ducks and relate the timing and duration of incubation recesses to weather and nest loca-
TL;DR: Data support the hypothesis that embryonic metabolism among Procellariiformes is related to the extent to which the incubation period deviates from the expected value based on initial egg mass.
Abstract: The constraints placed on diffusive gas exchange by the eggshell and the adaptive features of embryonic respiration and metabolism in large Laysan and black-footed albatross eggs (300 g) during prolonged incubation (65 days) were examined in naturally incubated eggs on Sand Island, Midway, in the Northwestern Hawaiian Islands. A low eggshell gas conductance and slow growth rate were associated with a relatively low oxygen consumption (MO2) throughout incubation. Just prior to internal pipping (IP) of the inner shell membrane and penetration of the air space, the MO2 (pre-IP MO2) was approximately 1,250 ml O2 (STPD).day-1 for both species, resulting in air cell O2 and CO2 tensions of 106 and 40 Torr, respectively. During the 4- to 5-day pipping-to-hatching interval, O2 uptake increases rapidly as pulmonary respiration is initiated. Hatchling O2 consumption averaged 3,700 ml O2 (STPD).day-1 or about three times the pre-IP MO2. Data support the hypothesis that embryonic metabolism among Procellariiformes is related to the extent to which the incubation period deviates from the expected value based on initial egg mass.
TL;DR: The viability of heat-stressed cells of Escherichia coli was influenced by the temperature of incubation prior and subsequent to heat treatment, and these phenomena were observed with other Gram negative and positive bacteria, and yeasts.
Abstract: The viability of heat-stressed cells of Escherichia coli was influenced by the temperature of incubation prior and subsequent to heat treatment. The effect of pre-incubation temperature on the viability of heated cells was almost constant regardless of heating temperature in the range 48–54°C. The involvement of the change in fluidity of the membrane was suggested as a cause of the effects of pre-incubation and post-incubation. These phenomena were observed with other Gram negative and positive bacteria, and yeasts.
TL;DR: Skin fibroblasts from normal human subjects were exposed in vitro to long-wave ultraviolet radiation (UVA, 320-400 nm) alone, or in combination with 8-methoxypsoralen (8-MOP), and results suggest UVA irradiation in itself is capable of inducing DNA breaks, which are rapidly sealed during post-treatment incubation.
Abstract: Skin fibroblasts from normal human subjects were exposed in vitro to long-wave ultraviolet radiation (UVA, 320–400 nm) alone, or in combination with 8-methoxypsoralen (8-MOP). DNA damage was analysed with the alkaline elution technique before and after post-treatment incubation of the cells at 37°C for various times. Cells treated with UVA at 1.1 J/cm2 showed an increased DNA elution rate, which returned to the normal level within 30 min of post-treatment incubation. In cells treated with PUVA (8-MOP at 20 μg/ml plus UVA at 0.04 J/cm2), the alkaline elution rate was not different from untreated control cells, either before or after post-treatment incubation for times up to 7 days. When the PUVA treatment was followed first by a washing, to remove any unbound 8-MOP, and then by UVA (PUVA + UVA) at 1.1 J/cm2, the alkaline elution rate decreased below the control level. During the post-treatment incubation of the PUVA + UVA-treated cells there was a gradual increase of the alkaline elution rate to a level significantly above that in control cells. This increase was observed after 30 min. It reached a miaximum after 24 h and remained after 7 days of post-treatment incubation. Cells from a patient with xeroderma pigmentosum of complementation group A, which were given the same PUVA + UVA treatment, did not show any change in the alkaline elution rate during the post-treatment incubation. If, as seems likely, an increased alkaline elution rate indicates an increase of DNA breaks, and a decreased alkaline elution rate indicates the sealing of breaks and/or the formation of cross-links, the results would suggest the following: (1) UVA irradiation in itself is capable of inducing DNA breaks, which are rapidly sealed during post-treatment incubation; (2) PUVA treatment induces mono-adducts, some of which appear to remain in the DNA for at least 7 days of post-treatment incubation and can be activated to form DNA cross-links by a second dose of UVA; (3) DNA cross-links induced by PUVA + UVA can be recognized by a repair process that involves the formation of DNA breaks. This process is not observed in xeroderma pigmentosum cells of group A.
TL;DR: Homogenates of a human brain from a case of Creutzfeldt-Jakob disease and a homogenate of mouse brains from mouse passage 1 of the disease in mice contained no detectable conventional viruses.
Abstract: Homogenates of a human brain from a case of Creutzfeldt-Jakob disease and a homogenate of mouse brains from mouse passage 1 of the disease in mice contained no detectable conventional viruses. Both human material and mouse-passaged material were inoculated into nude mice, and the mouse-passaged material was also inoculated into eight different tissue culture lines. The tissue cultures showed no cytopathic changes or hemadsorption and failed to produce an increased amount of reverse transcriptase. The nude mice inoculated with human brain suspensions developed a disease identical to that in immunocompetent mice, with a nearly identical incubation period of 9 to 13 months. The incubation period of the disease in mice was under host genetic control and was, additionally, directly related to the inoculum size. The agent was resistant to 10% Formalin, 5% deoxycholate, 1% Triton X-100, and 5% glutaraldehyde; however, glutaraldehyde treatment resulted in a significant loss of infectivity. Approximately 1 log of infectivity was lost by heating brain suspensions to 80 degrees C for 15 min, with no additional loss upon further incubation up to 45 min. Heating at 100 degrees C for 15 min led to a 3-log loss of infectivity.
TL;DR: Concentrations of LH and FSH were generally higher during the early part of the breeding season than during late incubation and leading, whereas FSH concentrations in female swans did not change during this period.
TL;DR: Virus loss in activated sludge appeared to be caused by microorganisms, supported by the finding that poliovirus infectivity decreased during incubation in mixed-liquor suspended solids, primarily because of a sedimentable, heat-sensitive component.
Abstract: Virus loss in activated sludge appeared to be caused by microorganisms. This conclusion is supported by the finding that poliovirus infectivity decreased during incubation in mixed-liquor suspended solids, primarily because of a sedimentable, heat-sensitive component. Furthermore, broth spiked with mixed-liquor suspended solids acquired antiviral activity during incubation.
TL;DR: The presence of P-group plasmids in Rhizobium strains strongly inhibited the loss of nodulation ability during incubation at 35 degrees C, and it is possible that a product(s) of the genes of R-plasmids acts as a stabilizing agent on the replication process of the indigenous RhZobium plasmid.
Abstract: Of 18 Rhizobium trifolii strains tested, 12 showed a high frequency of loss of nodulation ability after incubation in cultures at elevated temperatures. A correlation between loss of nodulation ability and loss of a large plasmid was demonstrated for R. trifolii. In some nonnodulating (Nod-) mutants, deletions occurred instead of total elimination of the plasmid molecule. The maximum curing effect was observed in bacteria incubated at 35 degrees C. After 4 or more days of incubation at this temperature, the viability of bacteria decreased markedly, and the number of nonnodulating mutants increased significantly. At the elevated temperature DNA synthesis was stopped completely after 2 h, whereas protein synthesis proceeded for a few days. Microscopic observations showed that during the first 3 days of incubation at the elevated temperature, the bacterial cells increased markedly in size. These large irregular cells then divided and produced Nod- clones. Nonnodulating clones did not result from the selection of temperature-resistant mutants. The presence of P-group plasmids in Rhizobium strains strongly inhibited the loss of nodulation ability during incubation at 35 degrees C. The observed phenomenon did not result from integrative suppression. It is possible that a product(s) of the genes of R-plasmids acts as a stabilizing agent on the replication process of the indigenous Rhizobium plasmids. Images
01 Jan 1982
TL;DR: The need for both aerobic and anaerobic incubation of blood cultures is dependent upon the medium used and the microorganisms likely to be encountered, particularly when Bacteroidaceae are suspected as the cause of sepsis.
TL;DR: It is proposed that regulating the permeability of the egg shell may be important in preventing excessive drying of the inner shell membrane during early development along with limiting the total amount of water lost from the embryo during incubation.
Abstract: In this report we show that the amount of water lost during incubation is an important determinant of hatchability in embryos of the domestic chicken. However, when the loss of water is restricted to the first half versus the second half of the total incubation period, it is the loss of water during the first half that affects hatching success. We propose that regulating the permeability of the egg shell may be important in preventing excessive drying of the inner shell membrane during early development along with limiting the total amount of water lost from the embryo during incubation.
TL;DR: The results suggest that the activity of plasma membrane Na+K+-ATPase may be affected by HN2, and this enzyme may play a pivotal role in controlling cell growth and division.
TL;DR: Results indicate that the action of retinoic acid in the target organ may be mediated by its interaction with the nuclei, as shown in the case of N-methyl-N-nitrosourea-induced mammary cancers.
Abstract: Cellular retinoic acid-binding protein (CRABP) was detected in the nuclear fraction of N-methyl-N-nitrosourea-induced mammary cancers after the incubation of cytosol containing [3H]retinoic acid (RA)-bound CRABP with isolated nuclei. CRABP extracted from the nuclei in buffer containing 0.4 M-KCl sedimented as a 2 S component when subjected to sucrose-density-gradient analysis. [3H]RA-CRABP was found to be a prerequisite for the detection of nuclear binding, since the incubation of isolated nuclei or 0.4 M-KCl extract of the nuclei with [3H]RA did not result in any significant binding. Incubation of [3H]RA-CRABP at 25 or 30 degrees C before incubation with the nuclei neither altered the sedimentation coefficient nor enhanced the nuclear binding compared with 0 degrees C incubation. The tumour nuclei contained a saturable number of binding sites with a dissociation constant of 1.6 x 10(-9) M. These results indicate that the action of retinoic acid in the target organ may be mediated by its interaction with the nuclei.
TL;DR: Malformations and malpositions of the embryo were not affected by maternal energy or protein allowance and the low hatchability of eggs from birds on the 1.88 MJ AME allowance from 37 to 64 weeks could be related to the incidence of deaths in the first 5 d of the incubation period.
Abstract: 1. Broiler parent stock were fed daily allowances of 1.88, 1.73 or 1.52 MJ apparent metabolisable energy (AME) per bird at two different daily protein intakes (27.0 and 21.3 g crude protein (CP) per bird from 21 to 64 weeks of age. 2. The decrease in hatchability that occurred on the high protein (27.0 g CP), low energy (1.52 MJ AME) allowance from 26 to 36 weeks of age was due to an increase in the percentage of dead embryos in the second week of incubation and an increase in the number of "pipped" eggs at the end of incubation. 3. The low hatchability of eggs from birds on the 1.88 MJ AME allowance from 37 to 64 weeks could be related to the incidence of deaths in the first 5 d of the incubation period. 4. Malformations and malpositions of the embryo were not affected by maternal energy or protein allowance.
TL;DR: A concentration of 0.005% formaldehyde in phosphate-buffered saline (PBS) achieved complete immobilization of ram spermatozoa while also yielding good recovery of sperm motility after removal by washing, and recovery rate declined with increasing dilution rate.
Abstract: A concentration of 0.005% formaldehyde in phosphate-buffered saline (PBS) achieved complete immobilization of ram spermatozoa while also yielding good recovery of sperm motility after removal by washing. At a higher formaldehyde concentration (0.01%) recovery rate declined with increasing dilution rate. Incubation of spermatozoa in PBS containing 0.005% formaldehyde beyond 6 h at 5, 15 or 25 degrees C resulted in poor recovery rates. Of the incubation temperatures, eosin uptake was lowest at 25 degrees C. During 4 h post-wash incubation at 30 degrees C sperm motility was significantly (P less than 0.001) affected by pre-wash formaldehyde concentration which had no effect on the proportion of eosinophilic spermatozoa.
TL;DR: While experiments indicated that significant amounts of cholesterol moved rapidly from LDL to cultured cells with a dependence on time and LDL concentration, no increase in total cell cholesterol was detected in either cell line, suggesting that there may be important mechanisms in addition to the LDL pathway for the movement of lipids into cells.
TL;DR: It is concluded that rat granulosa cells have the capability to synthesize PGI2 and that this synthesis is stimulated by LH and a potent LHRH agonist, which is a potential mediator of hormone actions in the preovulatory follicle.
Abstract: The production of 6-keto-prostaglandin (PG)-F1 alpha by rat granulosa cells in vitro was measured in order to determine if the precursor of this compound, prostacyclin (PGI2), is a potential mediator of preovulatory changes in follicular function. Granulosa cells were collected from immature rats (27-29 days old) 48 h after an injection of PMSG (20 IU). The cells were incubated in medium 199 containing 1% BSA with or without arachidonic acid and various treatments for up to 5 h. PGI2 synthesis was determined by extracting the combined cells and medium, purifying the extract by thin layer chromatography, and measuring 6-keto-PGF1 alpha using a sensitive RIA. PGE synthesis was also determined by RIA in order to compare and contrast effects of treatments on PGE synthesis with those on 6-keto-PGF1 alpha synthesis. Both exogenous arachidonic acid and LH stimulated 6-keto-PGF1 alpha synthesis approximately 4-fold in comparison to controls during 5-h incubations. Maximum stimulation was achieved by the combination of arachidonic acid and LH. The effect of arachidonic acid was evident as early as 1 h of incubation, but LH had no effect until 3 h of incubation. PGE synthesis was also stimulated by arachidonic acid within 1 h of incubation and by LH within 3 h of incubation. A potent LHRH agonist also significantly stimulated 6-keto-PGF1 alpha and PGE production during a 5-h incubation, whereas three vasoactive agents (histamine, bradykinin, and angiotensin II) had no stimulatory effect on the synthesis of either compound. Based on the measurement of 6-keto-PGF1 alpha, it is concluded that rat granulosa cells have the capability to synthesize PGI2 and that this synthesis is stimulated by LH and a potent LHRH agonist. Therefore, PGI2 is a potential mediator of hormone actions in the preovulatory follicle.
TL;DR: The CDNB treated lenses were more susceptible to protein precipitation (cataract formation) when challenged with oxidants such as hydrogen peroxide and superoxide anions.
Abstract: A new method has been developed for the conjugation of rat lens glutathione by 1-chloro-2,4-dinitrobenzene (CDNB). This reaction is catalysed by glutathione S-transferase present in the lens. One milliliter of 1 mM CDNB per two rat lenses conjugates more than 95% of the lens GSH in 30 min at 37d`. Lenses incubated with 1 mM CDNB for 30 min, followed by incubation in the culture medium without CDNB remained apparently clear for up to 24 hrs. The CDNB treated lenses were more susceptible to protein precipitation (cataract formation) when challenged with oxidants such as hydrogen peroxide and superoxide anions.
01 Jan 1982
TL;DR: Individual cysts of the soybean nematode Heterodera glycines contained an average of 323 eggs, and hatching increased linearly as the incubation temperature was raised during a 2-wk test, with a pronounced increase of egg hatching.
Abstract: Individual cysts of the soybean nematode Heterodera glycines contained an average of 323 eggs. Hatching increased linearly as the incubation temperature was raised during a 2-wk test. Insignificant differences in egg hatching were found over 25°C or after pre-exposure to —4°C tem- peratures for 3 wk prior to 25°C incubation. Optimal hatching rates were obtained with 25% soil moisture and pH 6.0. Increases or decreases in these values depressed egg hatching of//, glycines. Soybean root leachate at 4.86 root-g-hr/ml significantly elevated hatching when compared to the control, whereas Hoagland's solution, a plant nutrient, showed a tendency to reduce hatching. In- cubation in ionic solutions revealed various effects. Sodium, calcium, potassium, and chloride re- vealed no effect and, indirectly, osmotic influences may be negligible. Incubation in nitrate and ferric concentrations showed insignificant increases in hatching. In contrast, exposure of//, glycines eggs to zinc chloride gave a pronounced increase of egg hatching.