The Effect of Morphactin on the Kinetics of Indol-3yl-acetic Acid-2-14C Transport in Zea mays L. Coleoptile Segments

This paper elucidates the effects of chloroflurenol (morphactin,IT 3456) treatment on the kinetics of ¹⁴C-IAA transport throughZea mays L. (cv. Orla-266) coleoptile segments. Maximum inhibitionof transport was achieved when chloroflurenol remained in contactwith the tissue segments for at least 20 min or more. The treatment,without materially affecting the ¹⁴C-IAA-transport polarity,or uptake, significantly reduced the velocity from 20.5 mm h^–1to 8.79 mm h^–1 and also the intensity from 919 (ct/min)h^–1 to 413 (ct/min) h^–1.     

Vascularization of normal human thyroid tissue transplanted to nude mice

The vascularization of normal human thyroid tissue transplanted to nude, athymic mice was examined by light, electron microscopy and autoradiography after continuous infusion of 3H-thymidine during 2, 4 and 6 days after transplantation. Labelled vascular sprouts were found in the surrounding host connective tissue after 2 days, in between peripheral follicles after 4 days and in central parts of the transplants after 6 days. The autoradiographic observations indicate that the sprouts originated from the surrounding host tissue. The amount of sprouts increased up to a maximum after 2 weeks of transplantation. At this time large interfollicular areas were occupied by sprouts. At later observations (3-5 weeks) sprouts occurred together with typical fenestrated capillaries. After 7 weeks all sprouts had differentiated into mature vessels. Our observations suggest that the transplanted thyroid tissue induces the formation of vascular sprouts in the surrounding host connective tissue. The sprouts then penetrate and vascularize the thyroid tissue.     

狐尾藻与黑藻断枝的不定根和新芽的形成

比较狐尾藻和黑藻2种沉水植物不同节位和不同长度断枝的不定根和新芽形成时间的结果表明,随着断枝节位的下降或断枝长度的增加,狐尾藻不定根的形成时间分别呈延长和缩短的趋势,其新芽均呈缩短趋势;而黑藻不定根的形成时间均呈缩短趋势,其新芽受节位与长度的影响不明显。     

Transcriptional profile of Salmonella enterica subsp. enterica serovar Weltevreden during alfalfa sprout colonization

Sprouted seeds represent a great risk for infection by human enteric pathogens because of favourable growth conditions for pathogens during their germination. The aim of this study was to identify mechanisms of interactions of Salmonella enterica subsp. enterica Weltevreden with alfalfa sprouts. RNA-seq analysis of S. Weltevreden grown with sprouts in comparison with M9-glucose medium showed that among a total of 4158 annotated coding sequences, 177 genes (4.3%) and 345 genes (8.3%) were transcribed at higher levels with sprouts and in minimal medium respectively. Genes that were higher transcribed with sprouts are coding for proteins involved in mechanisms known to be important for attachment, motility and biofilm formation. Besides gene expression required for phenotypic adaption, genes involved in sulphate acquisition were higher transcribed, suggesting that the surface on alfalfa sprouts may be poor in sulphate. Genes encoding structural and effector proteins of Salmonella pathogenicity island 2, involved in survival within macrophages during infection of animal tissue, were higher transcribed with sprouts possibly as a response to environmental conditions. This study provides insight on additional mechanisms that may be important for pathogen interactions with sprouts.     

Characteristics of low frequency magnetic field effect on swelling of wheat seeds at various stages]

Low-frequency magnetic field treatment (50 Hz, 30 mT, 15 min) of wheat seeds with a 50% germination efficiency during imbibition at the stage of root formation leads to a statistically significant increase in the number of seeds having sprouts, a still greater increase in the number of seeds having roots, and to an increase in the length of sprouts compared with the control and the seeds treated several hours later. In the last case, an increase in the germinating capacity with a considerably lesser effect on the number of seeds with roots was also observed. Prolonged treatment with the field during the second day of imbibition decreased reliably the length of sprouts with a weaker influence on the number of seeds with sprouts and roots. These data suggest the principal possibility of the effect of electromagnetic fields on the realization of the genetic program during the germination of wheat seeds.     

A versatile in vitro assay for investigating angiogenesis of the heart

Neovascularization in the heart is usually investigated with models of angiogenesis in vivo. Here we present a simple model that allows investigating heart angiogenesis in mice and rats in vitro. Small pieces of left ventricular myocardium were cultured in three-dimensional fibrin gels for 10 days. A single mouse heart allowed assessing 24 conditions, each tested in octuplicates. Rat recombinant VEGF164, human recombinant bFGF, and human recombinant PDGF-BB were used under normoxia (21% O2) and hypoxia (3% O2), and outgrowth of endothelial sprouts from heart pieces was quantified. In 4-week-old OF1 mice, endothelial sprouts formed spontaneously. In contrast, in 12-week-old adult mice, virtually no sprouts formed under normoxia. Under hypoxia, sprout formation increased substantially. Different growth factors induced formation of distinct patterns of sprouts and unorganized single cells. Sprouts were composed of endothelial cells with smooth muscle cells or pericytes interacting with them, as assessed by immunohistochemistry. Taken together, our model is suited for investigation of angiogenesis of the heart in vitro. It may allow performing extensive series of experiments in vitro including rapid screening of pharmacological compounds and assessment of mechanisms of heart angiogenesis in transgenic animals in an easy straightforward manner.     

Juvenile sprouting ability of the endangered maple, <Emphasis Type="Italic">Acer pycnanthum</Emphasis>

Japanese red maple, Acer pycnanthum, is an endangered species having a limited distribution of central Honshu, Japan. Sprouting is an important part of its natural history, and many remnant populations contain high number of multiple-stem clones. However, knowledge of sprout formation and growth is lacking, which has hampered understanding of the reestablishment process after major disturbance. My research objectives were to characterize the formation and growth of basal sprouts in the juvenile stage and determine the effects of light intensity and stump diameter on these characteristics. Twenty sprouting clones were investigated at a natural site in Nagano Prefecture during a four-year period after cutting. Japanese red maple exhibited abundant and vigorous sprouting from the root collar of cut trees. Many sprouts arose immediately after cutting. Average number of sprouts per stump was 12.2. Number of sprouts per stump was negatively correlated with relative light intensity. The two dominant sprouts (sprouts 1 and 2) of each clone were selected to analyze their growth. The average extension growth of sprout 1 (i.e., the tallest and most vigorous) was 173.3 cm at the end of first growing season. At the end of fourth growing season, average height and diameter at breast height (dbh) of sprout 1 were 377 and 2.1 cm, respectively. Relative light intensity and stump diameter significantly and positively affected D²H (diameter at breast height squared × height) of sprout 1. Because the growth rate of sprouts is much faster than that of seedlings, regeneration by sprouting is more significant than seedling regeneration to maintain populations after disturbances.     

Physical site characteristics of wetland ecosystems dominated by the endangered maple, <Emphasis Type="Italic">Acer pycnanthum</Emphasis>

Japanese red maple, Acer pycnanthum, is an endangered species having a limited distribution of central Honshu, Japan. Sprouting is an important part of its natural history, and many remnant populations contain high number of multiple-stem clones. However, knowledge of sprout formation and growth is lacking, which has hampered understanding of the reestablishment process after major disturbance. My research objectives were to characterize the formation and growth of basal sprouts in the juvenile stage and determine the effects of light intensity and stump diameter on these characteristics. Twenty sprouting clones were investigated at a natural site in Nagano Prefecture during a four-year period after cutting. Japanese red maple exhibited abundant and vigorous sprouting from the root collar of cut trees. Many sprouts arose immediately after cutting. Average number of sprouts per stump was 12.2. Number of sprouts per stump was negatively correlated with relative light intensity. The two dominant sprouts (sprouts 1 and 2) of each clone were selected to analyze their growth. The average extension growth of sprout 1 (i.e., the tallest and most vigorous) was 173.3 cm at the end of first growing season. At the end of fourth growing season, average height and diameter at breast height (dbh) of sprout 1 were 377 and 2.1 cm, respectively. Relative light intensity and stump diameter significantly and positively affected D²H (diameter at breast height squared × height) of sprout 1. Because the growth rate of sprouts is much faster than that of seedlings, regeneration by sprouting is more significant than seedling regeneration to maintain populations after disturbances.     

Heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli

Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 degrees C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 degrees C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.     

Inhibition of oxidative DNA damage in vitro by extracts of brussels sprouts

Cruciferous vegetables have cancer preventive effects which may be due to reduction of oxidative DNA damage. We investigated the effect of an aqueous extract of cooked Brussels sprouts on formation of 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) in calf thymus DNA in vitro. Damage was induced by a Fenton reaction, UVC (254 nm), UVA (365 nm), sunlamp light, and methylene blue with visible light.

The extract inhibited 8-oxodG formation in all systems except visible light with methylene blue. The IC₅₀ values were 6-20 μg/ml corresponding to the extract of 5-20 g of Brussels sprouts distributed in a volume of 50 L. The protective effect in the Fenton reaction was unaffected by addition of EDTA. After HPLC separation fractions were identified with similar DNA protective effects. Sinigrin, a glucosinolate abundant in Brussels sprouts, co-eluted with the most effective fraction and had DNA protective effects. In comparison with other antioxidants the patterns of effect of the extract in the five damage systems were more similar to that of sodium azide than to those of dimethylsulfoxide and vitamin C.

Constituents of Brussels sprouts can protect DNA by direct scavenging, e.g. hydroxyl radical and other oxidants, without prooxidant effects at concentrations potentially achievable by modest intake of the vegetable.     

Polysaccharides cellulose, poly-beta-1,6-n-acetyl-D-glucosamine, and colanic acid are required for optimal binding of Escherichia coli O157:H7 strains to alfalfa sprouts and K-12 strains to plastic but not for binding to epithelial cells

When Escherichia coli O157:H7 bacteria are added to alfalfa sprouts growing in water, the bacteria bind tightly to the sprouts. In contrast, laboratory K-12 strains of E. coli do not bind to sprouts under similar conditions. The roles of E. coli O157:H7 lipopolysaccharide (LPS), capsular polysaccharide, and exopolysaccharides in binding to sprouts were examined. An LPS mutant had no effect on the binding of the pathogenic strain. Cellulose synthase mutants showed a significant reduction in binding; colanic acid mutants were more severely reduced, and binding by poly-beta-1,6-N-acetylglucosamine (PGA) mutants was barely detectable. The addition of a plasmid carrying a cellulose synthase gene to K-12 strains allowed them to bind to sprouts. A plasmid carrying the Bps biosynthesis genes had only a marginal effect on the binding of K-12 bacteria. However, the introduction of the same plasmid allowed Sinorhizobium meliloti and a nonbinding mutant of Agrobacterium tumefaciens to bind to tomato root segments. These results suggest that although multiple redundant protein adhesins are involved in the binding of E. coli O157:H7 to sprouts, the polysaccharides required for binding are not redundant and each polysaccharide may play a distinct role. PGA, colanic acid, and cellulose were also required for biofilm formation by a K-12 strain on plastic, but not for the binding of E. coli O157:H7 to mammalian cells.     

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Cruciferous vegetables have cancer preventive effects which may be due to reduction of oxidative DNA damage. We investigated the effect of an aqueous extract of cooked Brussels sprouts on formation of 7-hydro-8-oxo-2′-deoxyguanosine (8-oxodG) in calf thymus DNA in vitro. Damage was induced by a Fenton reaction, UVC (254 nm), UVA (365 nm), sunlamp light, and methylene blue with visible light.

The extract inhibited 8-oxodG formation in all systems except visible light with methylene blue. The IC₅₀ values were 6–20 μg/ml corresponding to the extract of 5–20 g of Brussels sprouts distributed in a volume of 50 L. The protective effect in the Fenton reaction was unaffected by addition of EDTA. After HPLC separation fractions were identified with similar DNA protective effects. Sinigrin, a glucosinolate abundant in Brussels sprouts, co-eluted with the most effective fraction and had DNA protective effects. In comparison with other antioxidants the patterns of effect of the extract in the five damage systems were more similar to that of sodium azide than to those of dimethylsulfoxide and vitamin C.

Constituents of Brussels sprouts can protect DNA by direct scavenging, e.g. hydroxyl radical and other oxidants, without prooxidant effects at concentrations potentially achievable by modest intake of the vegetable.     

A mathematical model of tumour-induced capillary growth

The corneal limbal vessels of an animal host respond to the presence of a source of Tumour Angiogenesis Factor (TAF) implanted in the cornea by the formation of new capillaries which grow towards the source. This neovasculature can be easily seen and studied and this paper describes a mathematical model of some of the important features of the growth. The model includes the diffusion of TAF, the formation of sprouts from pre-existing vessels and models the movement of these sprouts to form new capillaries as a chemotactic response to the presence of TAF. Numerical results are produced for various values of the parameters which characterize the model and it is suggested that the model might form the framework for further theoretical work on related phenomena such as wound healing or to develop strategies for the investigation of anti-angiogenesis.     

A Cell-Based Model of Extracellular-Matrix-Guided Endothelial Cell Migration During Angiogenesis

Angiogenesis, the formation of new blood vessels sprouting from existing ones, occurs in several situations like wound healing, tissue remodeling, and near growing tumors. Under hypoxic conditions, tumor cells secrete growth factors, including VEGF. VEGF activates endothelial cells (ECs) in nearby vessels, leading to the migration of ECs out of the vessel and the formation of growing sprouts. A key process in angiogenesis is cellular self-organization, and previous modeling studies have identified mechanisms for producing networks and sprouts. Most theoretical studies of cellular self-organization during angiogenesis have ignored the interactions of ECs with the extra-cellular matrix (ECM), the jelly or hard materials that cells live in. Apart from providing structural support to cells, the ECM may play a key role in the coordination of cellular motility during angiogenesis. For example, by modifying the ECM, ECs can affect the motility of other ECs, long after they have left. Here, we present an explorative study of the cellular self-organization resulting from such ECM-coordinated cell migration. We show that a set of biologically-motivated, cell behavioral rules, including chemotaxis, haptotaxis, haptokinesis, and ECM-guided proliferation suffice for forming sprouts and branching vascular trees.     

Distinct signalling pathways regulate sprouting angiogenesis from the dorsal aorta and the axial vein

Angiogenesis, the formation of new blood vessels from pre-existing vessels, is critical to most physiological processes and many pathological conditions. During zebrafish development, angiogenesis expands the axial vessels into a complex vascular network that is necessary for efficient oxygen delivery. Although the dorsal aorta and the axial vein are spatially juxtaposed, the initial angiogenic sprouts from these vessels extend in opposite directions, indicating that distinct cues may regulate angiogenesis of the axial vessels. We found that angiogenic sprouts from the dorsal aorta are dependent on vascular endothelial growth factor A (Vegf-A) signalling, and do not respond to bone morphogenetic protein (Bmp) signals. In contrast, sprouts from the axial vein are regulated by Bmp signalling independently of Vegf-A signals, indicating that Bmp is a vein-specific angiogenic cue during early vascular development. Our results support a paradigm whereby different signals regulate distinct programmes of sprouting angiogenesis from the axial vein and dorsal aorta, and indicate that signalling heterogeneity contributes to the complexity of vascular networks.     

Cell lineages and early patterns of embryonic CNS vascularization

First steps of blood vessel formation and patterning in the central nervous system (CNS) of higher vertebrates are presented. Corresponding to the regional diversity of the embryonic CNS (unsegmented spinal cord vs segmented brain anlagen) and its surroundings (segmented trunk vs unsegmented head mesoderm, neural crest-derived mesenchyme), cells of different origins contribute to the endothelial and mural cell populations. The autonomous migratory potential of endothelial cells is guided by attractive and repulsive clues. Nevertheless, a common pattern in both spinal cord and forebrain vascularization appears, with primary ventral vascular sprouts supplying the periventricular vascular plexus of the neural tube, whereas dorsolateral sprouts appear later.Key words: angiogenesis, blood vessel, brain, CNS, embryo, endothelial cell, neural crest, neural tube, pattern formation, pericyte, spinal cord     

Morphogenesis of the antenna of the male silkmoth. Antheraea polyphemus, III. Development of olfactory sensilla and the properties of hair-forming cells

During adult development of the male silkmoth Antheraea polyphemus, the anlagen of olfactory sensilla arise within the first 2 days post-apolysis in the antennal epidermis (stage 1-3). Approximately on the second day, the primary dendrites as well as the axons grow out from the sensory neurons (stage 4). The trichogen cells start to grow apical processes approximately on the third day, and these hair-forming 'sprouts' reach their definite length around the ninth day (stages 5-6). Then the secretion of cuticle begins, the cuticulin layer having formed on day 10 (stage 7a). The primary dendrites are shed, the inner dendritic segments as well as the thecogen cells retract from the prospective hair bases, and the inner tormogen cells degenerate around days 10/11 (stage 7b). The hair shafts of the basiconic sensilla are completed around days 12/13 (stage 7c), and those of the trichoid sensilla around days 14/15 (stage 7d). The trichogen sprouts retract from the hairs after having finished cuticle formation, and the outer dendritic segments grow out into the hairs: in the basiconic sensilla directly through, and in the trichoid sensilla alongside, the sprouts. The trichogen sprouts contain numerous parallel-running microtubules. Besides their cytoskeletal function, these are most probably involved in the transport of membrane vesicles. During the phase of cuticle deposition, large numbers of vesicles are transported anterogradely from the cell bodies into the sprouts, where they fuse with the apical cell membrane and release their electron-dense contents (most probably cuticle precursors) to the outside. As the cuticle grows in thickness, the surface area of the sprouts is reduced by endocytosis of coated vesicles. When finally the sprouts retract from the completed hairs, the number of endocytotic vesicles is further increased and numerous membrane cisterns seem to be transported retrogradely along the microtubules to the cell bodies. Here the membrane material will most probably be used again in the formation of the sensillum lymph cavities. Thus, the trichogen cells are characterized by an intensive membrane recycling. The sensillum lymph cavities develop between days 16-20 (stage 8), mainly via apical invaginations of the trichogen cells. The imago emerges on day 21.     

Response of Japanese beech (Fagus japonica Maxim.) sprouts to canopy gaps

The response of Japanese beech (Fagus japonica Maxim.) sprouts to canopy gaps in natural beech forest in central Japan was studied using two contrasted gaps in which tree-ring chronologies of regenerating stems were analyzed. The gaps were created by uprooting of a single Quercus mongolica var. grosseserrata stem (diameter: 50 cm; gap size: 40 m²; 23 years old) and by concurrent uprootings of four F. japonica stools (gap size: 180 m²; 30 years old). Japanese beech sprouts emerged before and after the gap formation and dominated stem populations in both gaps. In gaps, growth of F. japonica sprouts was equal or lower than growth of stems of seed origin, but most sprouts (F. japonica, Acer mono var. marmoratum) appeared a few years before emergence of seedlings. The small gap created by single stem fall was dominated by some beech sprouts from stools adjacent to the gap. The multiple gap was not closed by beech sprouts from stools surrounding the gap, but some dominant beech stems were resprouts from the uprooted beech stools. The existence of a sprout bank under the canopy may play an important role in the closing process of gaps in natural Japanese beech forest.     

Cell lineages and early patterns of embryonic CNS vascularization

First steps of blood vessel formation and patterning in the central nervous system (CNS) of higher vertebrates are presented. Corresponding to the regional diversity of the embryonic CNS (unsegmented spinal cord vs. segmented brain anlagen) and its surroundings (segmented trunk vs. unsegmented head mesoderm, neural crest-derived mesenchyme), cells of different origins contribute to the endothelial and mural cell populations. The autonomous migratory potential of endothelial cells is guided by attractive and repulsive clues. Nevertheless, a common pattern in both spinal cord and forebrain vascularization appears, with primary ventral vascular sprouts supplying the periventricular vascular plexus of the neural tube, whereas dorsolateral sprouts appear later.     

Evaluation of Nutritional Availability and Anti-Tumor Activity of Selenium Contained in Selenium-Enriched Kaiware Radish Sprouts

We estimated the nutritional availability of selenium (Se) in Se-enriched Kaiware radish sprouts (SeRS) by the tissue Se deposition and glutathione peroxidase (GPX) activity of rats administered the sprouts, and examined the effect of SeRS on the formation of aberrant crypt foci (ACF) in the colon of mice administered 1,2-dimethylhydrazine (DMH) to evaluate anti-tumor activity. Male weanling Wistar rats were divided into seven groups and fed a Se-deficient basal diet or the basal diet supplemented with 0.05, 0.10, or 0.15 μg/g of Se as sodium selenite or SeRS for 28 d. Supplementation with Se dose-dependently increased serum and liver Se concentrations and GPX activities, and the selenite-supplemented groups showed a higher increase than the SeRS-supplemented groups. The nutritional availability of Se in SeRS was estimated to be 33 or 64% by slope ratio analysis. Male 4-week-old A/J mice were divided into seven groups and fed a low Se basal diet or the basal diet supplemented with selenite, SeRS, or selenite + non-Se-enriched radish sprouts (NonSeRS) at a level of 0.1 or 2.0 μg Se/g for 9 weeks. After 1 week of feeding, all mice were given six subcutaneous injections of DMH (20 mg/kg) at 1-week intervals. The average number of ACF formed in the colon of mice fed the basal diet was 4.3. At a supplementation level of 0.1 μg Se/g, only SeRS significantly inhibited ACF formation. At a supplementation level of 2.0 μg Se/g, both selenite and SeRS significantly inhibited ACF formation. The addition of NonSeRS to the selenite-supplemented diets tended to inhibit ACF formation, but this was not statistically significant. These results indicate that SeRS shows lower nutritional availability but higher anti-tumor activity than selenite.