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At least 19 recordsLinked to original sources
PubMed2001

Final report on the safety assessment of Corylus Avellana (Hazel) Seed Oil, Corylus Americana (Hazel) Seed Oil, Corylus Avellana (Hazel) Seed Extract, Corylus Americana (Hazel) Seed Extract, Corylus Avellana (Hazel) Leaf Extract, Corylus Americana (Hazel) Leaf Extract, and Corylus Rostrata (Hazel) Leaf Extract.

These ingredients are all derived from hazelnut trees. The two seed oils are expressed from the nuts of the hazelnut tree of the particular species identified. Most current reported cosmetic uses are of the seed oils. The seed extracts are the extract of the nuts of the identified species tree. There is one current report of use of seed extract in cosmetics. The leaf extracts are the extract from the leaves of the particular species tree. There are no current reports of use of these extracts in cosmetics. Analysis of seed oil from one species identified Oleic Acid, Palmitoleic Acid, Linoleic Acid, Eicosaenoic Acid, Docosenoic Acid, Eicosanoic Acid, Palmitic Acid, Linolenic Acid, Stearic Acid, and Tetraeicosanoic Acid. Little information is available to characterize the extracts, however. The functions of most of these ingredients in cosmetics are not reported. In studies of hazelnuts from Spain and Egypt, aflatoxin was reported as a possible contaminant. Aflatoxins are considered carcinogenic in humans. Virtually no safety test data are available on these ingredients. Negative results in one comedogenicity study using a seed oil are reported. Cross-sensitivity to proteins in peanuts and those in hazelnuts are reported, but the presence or absence of protein in nut extract and plant extract from hazelnut trees is not known. Additional data were provided regarding concentration of use, method of extraction and contaminants, comedogenicity, and ultraviolet (UV) radiation absorption, but these data related to nut oil from only one species, and were not overall sufficient to resolve questions about irritation, sensitization, and photosensitization. Because of the absence of data, it is concluded that the available data are insufficient to support the safety of these ingredients in cosmetic products. Because of the limited information that characterizes any of these oils or extracts, data are needed on each (except that items 1, 2, and 3 below are not needed for Hazel [Corylus Avellana] Nut Oil). The additonal data needs include: (1) current concentration of use; (2) method of extraction/manufacture and quality control (i.e., chemical analyses); (3) contaminants and methods of extraction (especially pesticides and heavy metals); (4) dermal irritation and sensitization; (5) UV absorption; if there is significant absorption, then a photosensitization study will be needed; (6) 28-day dermal toxicity; (7) reproductive and developmental toxicity; and (8) two genotoxicity assays, one in a mammalian system; if positive, then a 2-year dermal carcinogenesis study using National Toxicology Program (NTP) methods may be needed.

Acne Vulgaris↗
PubMed1999

Comparisons of a proposed five-seed assay method with the single-seed and batch assay methods for I-125 seeds in ultrasound-guided prostate implants.

A simple five-seed assay method was proposed and investigated. A commercial well ion chamber system with an NIST-traceable single-seed calibration constant was used for the single-seed assays. A batch seed holder was used for batch assays. For the five-seed assays, a second single-seed holder was modified such that all five seeds were loaded in a central region of the well ion chamber. Compared with the same seed in the standard single-seed holder, the relative chamber responses for the five seed positions were 0.993, 0.993, 1.000, 1.001, and 0.977, respectively, indicating little or no position-dependent chamber response and no self-attenuation among seeds. Subsequent comparison of assays with the single-seed and five-seed methods indicated only 0.4% difference in charge collection. The five-seed calibration constant was therefore taken to be the same as the single-seed calibration constant. The reproducibility of the five-seed assay method was found to be better than 0.8%. When a dummy seed replaced an active seed, a nearly 20% reduction in charge was found, indicating that the proposed five-seed assay method can detect a dead seed. Clinical comparison of all three assay methods showed that they produced qualitatively the same assay results when the batch assay method was performed with extra care. Compared with the single-seed assay method, the five-seed method is equally simple, rigid, and reproducible, but it demands much less assay time. Compared with the batch assay method, the five-seed method is much more reproducible and reliable because of its rigid assay geometry; it only demands a moderate amount of assay time and can detect dead seeds. The American Association of Physicists in Medicine Task Group 40 (AAPM TG40) states that, for brachytherapy, ideally every (i.e., 100%) loose seed should be calibrated. For procedures involving large number of loose seeds, it then recommends that 10% of seeds be calibrated. The proposed five-seed assay is very simple to implement. It will facilitate the compliance of the "10%" recommendation from the AAPM TG40; it will make the "ideally 100%" statement from AAPM TG40 a more realistic and practical QA procedure in seed assaying.

Brachytherapy↗
PubMed2004

A comparison of the precision of seeds deposited as loose seeds versus suture embedded seeds: a randomized trial.

PURPOSE: Brachytherapy for prostate cancer with permanent low-dose-rate seeds has been shown to be an effective treatment for early stage prostate cancer. Due to the rapid falloff of dose, accurate seed placement is critical for optimal dosimetry. One approach to achieve optimal dosimetry is the use of seeds embedded in suture material. Seeds embedded in suture may not move after implantation as much as loose seeds. This would improve implant dosimetry. To evaluate this hypothesis a formal study was conducted in which half the gland was implanted with seeds embedded in suture and half with loose seeds. Final dosimetry is compared between both halves of the prostate. METHODS AND MATERIALS: Patients entered this Investigational Review Board approved prospective trial after completion of informed consent. At time of implant, the side of the gland to be implanted with loose as opposed to suture embedded seeds was randomly assigned. The patients then underwent intraoperative preplanned implantation. None of the preplans directed seed locations outside the prostate. Both the seeds embedded in suture and the loose seeds were implanted using needles with stylettes. At 4-6 weeks post implant, seed location was determined with CT. Both sides of the gland on CT were contoured and used for final dosimetric calculations. A cost function analysis was used to determine individual seed position deviation from intended to actual seed location. RESULTS: Eight patients were enrolled in the study. A total of 549 seeds were implanted; 240 seeds embedded in suture and 309 loose seeds. Prostate volumes ranged from 24.0-45.5 cc with a mean of 38.6 cc. The average radial deviation of the loose seeds from planned position was determined to be 3.1 mm compared with the average radial deviation of the suture embedded seeds of 3.7 mm. There was no improvement in the final dosimetry when suture embedded seeds where used. The D90 and V100 values for the half of the prostate implanted with suture embedded seeds were 71-140 (mean, 92.1) and 80.2-99.5 (mean, 89.6), respectively, for the half of the prostate implanted with loose seeds. (All D90, V100 values are % of prescription dose.) CONCLUSION: Seeds embedded in suture material do not lead to superior precision in seed deposition when compared with loose seeds, when implanted inside the prostate.

Brachytherapy↗
PubMed2005

Commercial Seed Lots Exhibit Reduced Seed Dormancy in Comparison to Wild Seed Lots of Echinacea purpurea.

Seed germination patterns were studied in E. purpurea (L.) Moench grouped by seed source, one group of seven lots from commercially cultivated populations and a second group of nine lots regenerated from ex situ conserved wild populations. Germination tests were conducted in a growth chamber in light (40 μmol·m(-2)·s(-1)) or darkness at 25 °C for 20 days after soaking the seeds in water for 10 minutes. Except for two seed lots from wild populations, better germination was observed for commercially cultivated populations in light (90% mean among seed lots, ranging from 82% to 95%) and in darkness (88% mean among seed lots, ranging from 82% to 97%) than for wild populations in light (56% mean among seed lots, ranging from 9% to 92%) or in darkness (37% mean among seed lots, ranging from 4% to 78%). No germination difference was measured between treatments in light and darkness in the commercially cultivated populations, but significant differences were noted for treatments among wild populations. These results suggest that repeated cycles of sowing seeds during cultivation without treatments for dormancy release resulted in reduced seed dormancy in E. purpurea.

Journal Article↗
PubMed2001

Seed-specific over-expression of an Arabidopsis cDNA encoding a diacylglycerol acyltransferase enhances seed oil content and seed weight.

We recently reported the cloning and characterization of an Arabidopsis (ecotype Columbia) diacylglycerol acyltransferase cDNA (Zou et al., 1999) and found that in Arabidopsis mutant line AS11, an ethyl methanesulfonate-induced mutation at a locus on chromosome II designated as Tag1 consists of a 147-bp insertion in the DNA, which results in a repeat of the 81-bp exon 2 in the Tag1 cDNA. This insertion mutation is correlated with an altered seed fatty acid composition, reduced diacylglycerol acyltransferase (DGAT; EC 2.3.1.20) activity, reduced seed triacylglycerol content, and delayed seed development in the AS11 mutant. The effect of the insertion mutation on microsomal acyl-coenzyme A-dependent DGAT is examined with respect to DGAT activity and its substrate specificity in the AS11 mutant relative to wild type. We demonstrate that transformation of mutant AS11 with a single copy of the wild-type Tag1 DGAT cDNA can complement the fatty acid and reduced oil phenotype of mutant AS11. More importantly, we show for the first time that seed-specific over-expression of the DGAT cDNA in wild-type Arabidopsis enhances oil deposition and average seed weight, which are correlated with DGAT transcript levels. The DGAT activity in developing seed of transgenic lines was enhanced by 10% to 70%. Thus, the current study confirms the important role of DGAT in regulating the quantity of seed triacylglycerols and the sink size in developing seeds.

Acyl Coenzyme A↗
PubMed2003

The relationship between beta-mannosidase and endo-beta-mannanase activities in tomato seeds during and following germination: a comparison of seed populations and individual seeds.

beta-Mannosidase and endo-beta-mannanase are involved in the mobilization of the mannan-containing cell walls of the tomato seed endosperm. The activities of both enzymes increase in a similar temporal manner in the micropylar and lateral endosperm during and following germination. This increase in enzyme activities in the micropylar endosperm is not markedly reduced in seeds imbibed in abscisic acid although, in the lateral endosperm, endo-beta-mannanase activity is more suppressed by this inhibitor than is the activity of beta-mannosidase. Gibberellin-deficient (gib-1) mutants of tomato do not germinate unless imbibed in gibberellin; low beta-mannosidase activity, and no endo-beta-mannanase activity is present in seeds imbibed in water, but both enzymes increase strongly in activity in the seeds imbibed in the growth regulator. For production of full activity of both beta-mannosidase and endo-beta-mannanase in the endosperm, this tissue must be in contact with the embryo for at least the first 6 h of imbibition, which is indicative of a stimulus diffusing from the embryo to the endosperm during this time. These results suggest some correlation between the activities of beta-mannosidase and endo-beta-mannanase, particularly in the micropylar endosperm, in populations of tomato seeds imbibed in water, abscisic acid and gibberellin. However, when individual micropylar endosperm parts are used to examine the effect of the growth regulators and of imbibition in water on the production of the two enzymes, it is apparent that within these individual seed parts there may be large differences in the amount of enzyme activity present. Micropylar endosperms with high endo-beta-mannanase activity do not necessarily have high beta-mannosidase activity, and vice versa, which is indicative of a lack of co-ordination of the activities of these two enzymes within individuals of a population.

Germination↗
PubMed1998

Seed dispersal by neotropical seed predators.

From a plant's perspective, the difference between a seed predator and a seed disperser should be straightforward: attract animals that will disperse seeds and defend seeds from potential predators. Unlike pulp-eating frugivores, seed predators regularly encounter diverse plant protective mechanisms. The purpose of this paper is to examine feeding constraints, morphological adaptations, and the mechanical process of seed predation. While there is evidence that some seed predators cause severe losses to seed crops, there is also evidence that seed predators enhance seed dispersal and germination. We also examine four methods by which neotropical seed predators may contribute to dispersal. 1) Seed predators examined here ingested fruit when seeds were full-sized, but not yet mature (i.e., seeds of mature fruit may be avoided by seed predators and available for dispersal by other frugivores). 2) Sympatric seed predators may ingest seeds from different plants thus reducing overall predator load on any individual plant. 3) Seed predators that manipulate seeds (e.g., remove pericarp and seed coat) may enhance germination if the prepared seeds are dropped, discarded, or buried and not ingested. 4) Small seeds may miss mastication and swallowed intact with a food bolus. The last mechanism is the most likely to contribute to seed dispersal by the widest array of vertebrate seed predators, but primate seed predators may facilitate seed dispersal using all four mechanisms. Therefore, the traditional dichotomy of seed predator vs. seed disperser oversimplifies the interactions between seed predators and plants.

Animals↗
PubMed2004

Effects of dung and seed size on secondary dispersal, seed predation, and seedling establishment of rain forest trees.

Seeds dispersed by tropical, arboreal mammals are usually deposited singly and without dung or in clumps of fecal material. After dispersal through defecation by mammals, most seeds are secondarily dispersed by dung beetles or consumed by rodents. These post-dispersal, plant-animal interactions are likely to interact themselves, as seeds buried by dung beetles are less likely to be found by rodents than unburied seeds. In a series of three experiments with seeds of 15 species in central Amazonia (Brazil), we determined (1) how presence and amount of dung associated with seeds influences long-term seed fate and seedling establishment, (2) how deeply dung beetles bury seeds and how burial depth affects seedling establishment, and (3) how seed size affects the interaction between seeds, dung beetles, and rodents. Our overall goal was to understand how post-dispersal plant-animal interactions determine the link between primary seed dispersal and seedling establishment. On average, 43% of seeds surrounded by dung were buried by dung beetles, compared to 0% of seeds not surrounded by dung ( n=2,156). Seeds in dung, however, tended to be more prone than bare seeds to predation by rodents. Of seeds in dung, probability of burial was negatively related to seed size and positively related to amount of dung. Burial of seeds decreased the probability of seed predation by rodents three-fold, and increased the probability of seedling establishment two-fold. Mean burial depth was 4 cm (0.5-20 cm) and was not related to seed size, contrary to previous studies. Probability of seedling establishment was negatively correlated with burial depth and not related to seed size at 5 or 10 cm depths. These results illustrate a complex web of interactions among dung beetles, rodents, and dispersed seeds. These interactions affect the probability of seedling establishment and are themselves strongly tied to how seeds are deposited by primary dispersers. More generally, our results emphasize the importance of looking beyond a single type of plant-animal interaction (e.g., seed dispersal or seed predation) to incorporate potential effects of interacting interactions.

Animals↗
PubMed1998

Seed handling by three prosimian primates in southeastern Madagascar: implications for seed dispersal.

In this paper, we studied three species of prosimian primate (Propithecus diadema edwardsi, Eulemur fulvus rufus, and Eulemur rubriventer) from June-July 1995 at the Ranomafana National Park to answer three questions: 1) how they handle and process seeds, 2) how the physical properties of seeds influence seed handling and seed fate, and 3) whether handling and processing patterns influence seed dispersal. Seeds from five plant species were collected from feces and examined for external damage (punctures and scrapes), weighed, measured, and checked daily for germination. P. d. edwardsi masticated seeds into two or more pieces while feeding. Seed fragments were either dropped under the parent tree or chewed and swallowed; seeds never emerged as recognizable units in feces. In contrast, both Eulemur species either dropped or swallowed seeds whole while feeding. E. rubriventer passed seeds that were longer, wider, and heavier than seeds passed by E.f. rufus. Although seeds emerged as separate units when passed by both Eulemur species, 65 Protorhus sp. seeds were scraped and/or punctured prior to being swallowed. Based on physical property tests, Protorhus seeds were more susceptible to mastication than undamaged seeds from Eugenia sp., Cissus sp., and Chrysophyllum madagascariensis. H. madagascariensis seeds also were undamaged but had physical properties comparable to Protorhus and may avoid being masticated due to their small size (2-3 mm). All damaged seeds were moldy or rotten within 6 days, and only 15% of the undamaged seeds passed by E. rubriventer germinated. None of the seeds passed by E.f. rufus germinated. Eulemur species also rested in the same tree after feeding and defecated prior to a new feeding bout or before moving, so seeds were most likely to be dispersed under the parent tree. Consequently, we concluded that these primate species do not appear to serve as effective seed dispersers for these plant species at this time of year.

Animals↗
PubMed2001

Wrinkled alfalfa seeds harbor more aerobic bacteria and are more difficult to sanitize than smooth seeds.

At least 14 separate outbreaks of food poisoning attributed to either Salmonella enterica or Escherichia coli O157:H7 have been traced to sprouts in the past decade. Seeds contaminated with human pathogens caused most of these outbreaks, thus many sprout growers are now treating alfalfa seeds with the sanitizing agent, calcium hypochlorite (Ca[OCl]2), prior to sprouting. The efficacy of alfalfa seed sanitation varies between seed lots and between seeds within each lot. Alfalfa seeds from different seed lots were sorted by type in an effort to determine if certain seed types carry more aerobic bacteria than other seed types. Seeds with a wrinkled type, characteristic of lygus bug damage, had significantly higher levels of culturable aerobic bacteria and were more difficult to sanitize than smooth, healthy seeds. After sanitation, wrinkled alfalfa seeds that had been inoculated with S. enterica ser. Newport carried significantly higher levels of Salmonella Newport than smooth seeds. If S. enterica is present on wrinkled seeds in naturally contaminated seed lots, it may be difficult to chemically sanitize the seed lot. Removal of the wrinkled alfalfa seeds from the seed lots, perhaps by adapting color sorting equipment similar to that used to sort rice grains and other seeds, should reduce the level of aerobic bacteria in seed lots and may result in lower levels of human pathogens on contaminated alfalfa seeds.

Bacteria, Aerobic↗
PubMed2004

The robustness of dose distributions to displacement and migration of 125I permanent seed implants over a wide range of seed number, activity, and designs.

PURPOSE: To investigate the robustness of permanent prostate implant dosimetry for various (125)I seed activities and various seed models. The dosimetric impact of seed misplacement and seed migration (seed loss) is also taken into account using various standard dose indices. METHODS AND MATERIALS: A dose-based inverse planning algorithm is used for automated dosimetric plan creation (45-60 s per plan) and provides an unbiased way to compare the robustness of various optimal dosimetric plans. Seed misplacement and seed migration are simulated by way of Monte Carlo, based on the measured displacement distributions from clinical postimplant cases. Plans were generated for seed activities between 0.2 and 1.4 mCi (0.25 to 1.78 U) and for 11 different seed models. RESULTS: The numbers of seeds and needles are shown to decrease rapidly for a seed activity between 0.3 mCi and 0.6 mCi (0.38 and 0.76 U). The loss in V100, from 100%, because of seed misplacement is below 10% for an apparent activity ranging from 0.2 to 0.9 mCi (0.25 to 1.14 U). A minimum degradation in V100 is observed around 0.6-0.7 mCi (0.76-0.89 U). D90 increases from 150 to 170 Gy between 0.3 and 0.7 mCi (0.38 and 0.89 U) and decreases afterward to fall below 140 Gy at higher activity. V200 and D10 to the target volume both show an increase in hot spots up to 0.7 mCi, and then decrease linearly at higher activities for all seed models. V200 and D10 to the urethra remain about constant for all seed activities up to 0.8 mCi (1.02 U), at which point they start to decrease. All seed models follow this general trend. CONCLUSIONS: Plans were shown to be robust to misplacement and migration of seeds over a wide range of seed activity and for various seed models. With a properly tuned inverse planning algorithm able to ensure the dose coverage and protection for the organs at risk in the presence of placement errors (displacement and migration), the choice of a preferred seed activity, in a range up to about 0.7 mCi (0.89 U), is open. The upper part of this range offers the opportunity to significantly reduce the number of seeds and needles, thus reducing surgical trauma to the patient, saving time in an operating room planning setting, and reducing the cost of a permanent prostate implant procedure.

Algorithms↗
PubMed2000

The influence of aerated hydration seed treatment on seed longevity as assessed by the viability equations.

Aerated hydration (AH) treatments of cauliflower seeds for 12 h (12AH) and 28 h (28AH) at 20 degrees C resulted in improved or reduced storage potential of low or high vigour seeds, respectively. Seeds were stored at their initial seed moisture content (mean 5.5% mc) or at 12% mc at 10 degrees C for 12 months and at 20 degrees C for 4 months. The improved longevity of low vigour seeds was associated with increased K(i) (initial seed viability) and a reduced rate of deterioration (1/sigma) whereas the K(i) of high vigour seeds fell after 28AH and the rate of deterioration increased such that the time to lose one probit of viability decreased from 28.7 to 5.3 months at 10 degrees C and from 10.4 to 1.2 months at 20 degrees C. The improved K(i) of low vigour seeds could be explained by the reduction in the extent of deterioration after AH, as indicated by the increase in germination after cotrolled deterioration (CD), and the possible activation of metabolic repair during treatment. In contrast the reduced germination after CD of AH-treated high vigour seeds was indicative of deterioration as a result of treatment. Both high and low vigour seeds contained constitutive levels of ss-tubulin which increased during AH treatment, the increase being greater in high vigour seeds. High vigour seeds also showed an increase in the proportion of nuclear DNA present as 4C DNA, from 3% (untreated seeds) to 26% (28AH), indicative of germination advancement from the G(1) to G(2) phase of the cell cycle during treatment. This higher proportion of 4C DNA is correlated with the increased sensitivity of seeds to drying and/or storage after AH, leading to their reduced K(i) and storage potential. In contrast, there was little change in %4C in low vigour seeds. Priming in polyethylene glycol (PEG, -1.0 MPa) for 5 d or 13 d also improved the longevity of low vigour seeds stored at their initial and 12% mc at 10 degrees C for 8 months, as reflected in their laboratory and CD germination. In this case, however, the improved longevity of the low vigour seeds following 13 d priming was associated with an increase in 4C DNA from 4% (dry control) to 56% after treatment. The germination of both untreated and primed high vigour seeds remained high throughout the storage period. Increases in the rate of germination (decreased mean germination time) observed after all AH and PEG treatments were not consistently associated with an increase in the proportion of nuclei containing 4C DNA.

Brassica↗
PubMed2002

Factors predictive of recurrence of retinal tumors, vitreous seeds, and subretinal seeds following chemoreduction for retinoblastoma.

OBJECTIVE: To identify the clinical features of eyes with retinoblastomas that predict the recurrence of retinal tumors, vitreous seeds, and subretinal seeds following treatment with chemoreduction. DESIGN: Prospective nonrandomized single-center clinical trial. SETTING: Ocular oncology service at Wills Eye Hospital of Thomas Jefferson University (Philadelphia, Pa) in conjunction with the division of oncology at Children's Hospital of Philadelphia. PARTICIPANTS: There were 158 eyes with 364 tumors in 103 consecutive patients with retinoblastoma managed with chemoreduction between June 1994 and August 1999. INTERVENTION: All patients received treatment for retinoblastoma with 6 cycles of chemoreduction using vincristine, etoposide, and carboplatin combined with focal treatment (cryotherapy, thermotherapy, or plaque radiotherapy) for each retinal tumor. MAIN OUTCOME MEASURES: The 3 main outcome measures included recurrence of retinal tumors, recurrence of vitreous seeds, and recurrence of subretinal seeds. The clinical features at the initial examination were analyzed for their association with the main outcome measures using a series of Cox proportional hazards regressions. RESULTS: All retinal tumors, vitreous seeds, and subretinal seeds showed an initial favorable response of regression during this treatment regimen. Using Kaplan-Meier estimates, at least 1 retinal tumor recurrence per eye was found in 37% of eyes at 1 year, 51% at 3 years, and no further increase at 5 years. By multivariate analysis, the only factor predictive of retinal tumor recurrence was the presence of tumor-associated subretinal seeds at the initial examination. Of the 54 eyes that had vitreous seeds at the initial examination, vitreous seed recurrence was found in 26% of eyes at 1 year, 46% at 3 years, and 50% at 5 years. By univariate analysis, the only factor predictive of vitreous seed recurrence was the presence of tumor-associated subretinal seeds at the initial examination. Of the 71 eyes that had subretinal seeds at the initial examination, subretinal seed recurrence was detected in 53% of eyes at 1 year, 62% at 3 years, and no further increase at 5 years. By multivariate analysis, factors predictive of subretinal seed recurrence included a tumor base greater than 15 mm and a patient age of 12 months or younger at diagnosis. There were no patients who developed retinoblastoma metastasis, pinealoblastoma, or second malignant neoplasms. CONCLUSIONS: Chemoreduction combined with focal therapy is effective for selected eyes with retinoblastomas. Eyes with subretinal seeds at initial examination are at particular risk for recurrence of retinal tumor and vitreous seeds. Younger patients with large tumors are at risk for recurrence of subretinal seeds. Retinal tumor and subretinal seed recurrence seems to manifest within 3 years of follow-up. Close follow-up of all patients treated with chemoreduction is warranted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Changes in oligosaccharide content and antioxidant enzyme activities in developing bean seeds as related to acquisition of drying tolerance and seed quality.

Seeds of bean (Phaseolus vulgaris cv. Vernel) were collected throughout their development on the plant and dried at 15 degrees C and 75% relative humidity to a final moisture content of about 16% (fresh weight basis) to determine whether the onset of tolerance to this drying condition was related to changes in soluble sugars or the activities of the main antioxidant enzymes, namely superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR). Measurements of soluble sugars and enzyme activities were made after drying the seeds, and drying tolerance was evaluated by the ability of dried seeds to germinate and to produce normal seedlings. Seeds became tolerant to drying at 45 d after anthesis, a time marking physiological maturity. At physiological maturity, the moisture content of seeds was about 50-55% (fresh weight basis) and seed dry matter reached about 190 mg per seed. Seed vigour, evaluated by controlled deterioration and conductivity measurements, continued to increase after seed mass maturity, but decreased when seeds remained thereafter for more than 7 d on the plant. Acquisition of drying tolerance was coincident with an accumulation of raffinose and stachyose. Dried-tolerant seeds were also characterized by a high amount of sucrose, the most abundant sugar, and by a low content of monosaccharides. The (raffinose+stachyose)/sucrose ratio increased during seed filling, reaching a value close to 1 when all the seeds became tolerant to drying, and maintaining this proportion during the final stages of maturation. Acquisition of drying tolerance was also related to a reorientation of the enzymatic antioxidant defence system. Drying-tolerant dried seeds displayed high CAT and GR activities and low SOD and APX activities, while the opposite condition was observed in immature dried seeds. The shift in antioxidant enzymes corresponded to the beginning of the maturation-drying phase. These results suggest that oligosaccharide metabolism and enzymatic antioxidant defences may be involved in acquisition of drying tolerance during bean seed development, but are not related to seed vigour.

Adaptation, Physiological↗
PubMed2002

Redundant proteolytic mechanisms process seed storage proteins in the absence of seed-type members of the vacuolar processing enzyme family of cysteine proteases.

Seed-type vacuolar processing enzyme (VPE) activity is predicted to be essential for post-translational proteolysis of seed storage proteins in the protein storage vacuole of developing seeds. To test this hypothesis, we examined the protein profiles of developing and germinating seeds from Arabidopsis plants containing transposon-insertional knockout mutations in the genes that encode the two seed-type VPEs in Arabidopsis, betaVPE, which was identified previously, and deltaVPE, which is described here. The effects of these mutations were studied individually in single mutants and together in a double mutant. Surprisingly, we found that most of the seed protein still was processed proteolytically in seed-type VPE mutants. The minor differences observed in polypeptide accumulation between wild-type and betaVPE mutant seeds were characterized using a two-dimensional gel/mass spectrometric analysis approach. The results showed increased amounts of propolypeptide forms of legumin-type globulins accumulating in mutant seeds. However, the majority of protein (>80%) still was processed to mature alpha- and beta-chains, as observed in wild-type seeds. Furthermore, we identified several legumin-type globulin polypeptides, not corresponding to pro or mature forms, that increased in accumulation in betaVPE mutant seeds compared with wild-type seeds. Together, these results indicate the existence of both redundant and alternative processing activities in seeds. The latter was substantiated by N-terminal sequencing of a napin-type albumin protein, indicating cleavage consistent with previous in vitro studies using purified aspartic protease. Analysis of genome-wide transcript profiling data sets identified six protease genes (including an aspartic protease gene and betaVPE) that shared spatial and temporal expression patterns with seed storage proteins. From these results, we conclude that seed-type VPEs constitute merely one pathway for processing seed storage protein and that other proteolytic enzymes also can process storage proteins into chains capable of stable accumulation in mature seeds.

Amino Acid Sequence↗
PubMed2005

[Effects of seeding methods on seeding efficiency and initial cell distribution in 3-D scaffolds].

Cell seeding of three-dimensional scaffolds is the first step of the cultivation of engineered tissues. The cell seeding density and spatial distribution in a 3-D scaffold are critical to the morphogenetic development of an engineered tissue. In the present work, human fibroblasts were seeded to collagen-chitosan sponges by static seeding, stirred seeding and perfusion seeding. The effects of seeding conditions on the resulting seeding density, the seeding efficiency and the initial cell distribution were studied. The seeding efficiency was relatively high (88.9%) at low inoculation cell density, and decreased rapidly wjth the increasing of inoculation cell density in static seeding. Stirred seeding yielded the lowest seeding efficiency. Nonuniform initial cell distribution was observed in both static and stirred seeding. The perfusion seeding, which has a characteristic of high seeding efficiency (>77%) , high initial cell density and uniform initial cell distribution in 3-D scaffolds, is the optimum method for cell seeding to 3-D scaffold.

Cell Aggregation↗
PubMed1999

Seed handling in chimpanzees (Pan troglodytes) and redtail monkeys (Cercopithecus ascanius): implications for understanding hominoid and cercopithecine fruit-processing strategies and seed dispersal.

Primates are confronted with an array of constraints in feeding on fruit, including the removal of adhesive, energy-rich pulp from seeds. In this paper, I discuss how primates meet this challenge and present data on the fruit-processing and seed-handling behavior of chimpanzees and redtail monkeys in Kibale National Park, Uganda. These data are then related to these species' services as seed dispersers. Particular attention was paid to the methods by which primates removed pulp from seeds, the density of seed clumps that they deposited (by spitting, dropping, or defecating) to the forest floor, and the distance seeds were moved from parent trees. Distance and density differences in chimpanzee and redtail seed dispersal resulted from distinct fruit-processing and seed-handling methods. It was observed, in general, that redtail monkeys engaged in fine oral processing and were seed spitters: most seeds were dispersed in close proximity to parent trees (84% of spat seeds < 10 m of parent tree), and deposited singly (100% seeds spat singly). In contrast, chimpanzees were coarse fruit processors and seed swallowers: seeds were defecated in denser clumps (e.g., a mean of 149 large seeds/dung sample and hundreds of small seeds/dung sample), far from parent trees. I evaluate the factors that shape patterns of fruit processing in hominoids and cercopithecines, and argue that the observed seed handling differences can be attributed to differences in digestive retention times, oral anatomy, and alternative mechanisms by which to avoid the cost of seed ballast.

Animals↗