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PubMed2002

Seedling Development and Field Performance of Prairiegrass, Grazing Bromegrass, and Orchardgrass.

Seedling establishment is a critical phase in pasture management. Knowledge of the seedling development of new forages is necessary to develop management practices and recommend species mixtures for pasture seedings. We compared seedling growth and development of prairiegrass (Bromus willdenowii Kunth = B. catharticus Vahl), grazing bromegrass (B. stamineus Desv.), and orchardgrass (Dactylis glomerata L.) in controlled environment and field studies. Seedlings were sampled weekly for 7 wk in the growth chamber and greenhouse beginning 8 to 10 d after planting (DAP). The number and mass of leaves and roots were recorded. In the field, leaf development was measured during spring and fall of 1997, and leaf and root development were measured during spring and fall of 1999. Forage dry matter (DM) yield was measured in clipped field plots during 1998 to 2000. Grazing bromegrass had more leaves, about twice the number of tillers per seedling, and a greater seedling mass than other grasses. Grazing bromegrass also had 50 to 100% more tillers m(-2) than other grasses in clipped field plots. The larger seedling size and greater tiller density, however, did not translate into greater yield in clipped plots. Grazing bromegrass yielded 10 to 15% less than orchardgrass or prairiegrass. Because of their large seedlings and rapid development, prairiegrass and grazing bromegrass probably should be used at a lower seeding rate or perhaps not used in seed mixtures with small-seeded grasses. Seedlings of these grasses should be fully established by 40 to 50 DAP under favorable moisture and temperatures in the spring and late summer.

Journal Article↗
PubMed2000

Identification and quantification of hydroxamic acids in maize seedling root tissue and impact on western corn rootworm (Coleoptera: Chrysomelidae) larval development.

Hydroxamic acid content was analyzed in the root tissue of four maize, Zea mays L., lines using high-performance liquid chromatography (HPLC) and related to western corn rootworm, Diabrotica virgifera virgifera LeConte, larval development and survivorship. Maize lines evaluated included Mp710 (PI 596627), MpSWCB-4, (PI 550498), Sc213 (PI 548792), and Dk580 (DeKalb commercial hybrid). Maize plants from each line were grown in test tubes containing a transparent agarose gel medium in a growth chamber. After 8 d of growth, root tissue of each line was harvested and hydroxamic acid content analyzed using HPLC. Three hydroxamic acids, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), 6-methoxybenzoxazolinone (MBOA), and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA), were identified in the maize roots tested. DIMBOA concentration was quantified and ranged from 246.37 +/- 70.53 micrograms to 91.84 +/- 49.82 micrograms DIMBOA per gram of root tissue. No significant difference was found among lines in D. v. virgifera larval development and survivorship.

Animals↗
PubMed2006

Development of a kinetic metabolic model: application to Catharanthus roseus hairy root.

A kinetic metabolic model describing Catharanthus roseus hairy root growth and nutrition was developed. The metabolic network includes glycolysis, pentose-phosphate pathway, TCA cycle and the catabolic reactions leading to cell building blocks such as amino acids, organic acids, organic phosphates, lipids and structural hexoses. The central primary metabolic network was taken at pseudo-steady state and metabolic flux analysis technique allowed reducing from 31 metabolic fluxes to 20 independent pathways. Hairy root specific growth rate was described as a function of intracellular concentration in cell building blocks. Intracellular transport and accumulation kinetics for major nutrients were included. The model uses intracellular nutrients as well as energy shuttles to describe metabolic regulation. Model calibration was performed using experimental data obtained from batch and medium exchange liquid cultures of C. roseus hairy root using a minimal medium in Petri dish. The model is efficient in estimating the growth rate.

Catharanthus↗
PubMed1986

Skin sensory innervation patterns in embryonic chick hindlimb following dorsal root ganglion reversals.

During embryonic development skin sensory neurons in lumbosacral dorsal root ganglia (DRGs) establish their dermatomes and axonal projections in a precise, orderly fashion in the chick. To investigate mechanisms responsible for this specific outgrowth, the rostrocaudal order of DRGs T7-LS3 was reversed by rotating the corresponding segments of neural crest, either alone or together with the underlying neural tube in St.15-16 embryos. The resulting skin sensory innervation patterns, mapped physiologically or anatomically at St.29-40, differed between the two experimental groups. Following neural tube rotations DRGs tended to establish innervation patterns that were consonant with their original position in the embryo. Axons from these rotated DRGs generally projected into the appropriate pathways and innervated the appropriate region of skin. Neural crest rotations left the ventral neural tube (including the motor neuron precursors) largely intact. In this case rotated DRGs tended to establish innervation patterns in accordance with their new position in the embryo, almost as if no rotation had been made. These results cannot be explained solely by the inherent specificity of sensory neurons. Instead, the results are largely consistent with the suggestion (Honig et al., 1986; Landmesser and Honig, 1986) that motor axons can direct the outgrowth of sensory axons and thereby influence the establishment of sensory innervation patterns. Other mechanisms that may also affect the development of sensory innervation patterns are discussed.

Animals↗
PubMed1987

The subpedicle connective tissue graft. A bilaminar reconstructive procedure for the coverage of denuded root surfaces.

A mucogingival grafting procedure has been developed to cover denuded root surfaces. This procedure, the subpedicle connective tissue graft, is a bilaminar graft that is composed of a free connective tissue graft and an overlying pedicle graft. By overlaying grafted free connective tissue with a pedicle, the otherwise compromised section of free graft which covers a denuded root surface is supplied by plasmatic circulation from capillaries in the vascular portion of the pedicle allowing it to survive. In this report 29 teeth were treated and monitored for as long as 42 months. In the group with advanced recession of 7 to 10 mm, there was an average of 88% coverage. The subpedicle graft created a healthy, functional, and esthetic result that appeared resistant to further breakdown. The subpedicle graft is indicated when a single surgical procedure is desired that will predictably cover denuded root surfaces when there is inadequate keratinized gingiva available for a pedicle graft and where the prognosis is poor for root coverage with a free gingival graft.

Adolescent↗
PubMed2002

[Cell surface peroxidase--generator of superoxide anion in wheat root cells under wound stress].

Development of wound stress in excised wheat roots is known to be accompanied with an increase in reactive oxygen species (ROS) production, fall of membrane potential, release of K+ from cells, alkalization of extracellular solution, changes in respiration and metabolism of structural lipids. Dynamics of superoxide release correlates with changes in other physiological parameters, indicating the cross-reaction of these processes. Activity of peroxidase in extracellular solution after a 1 h incubation and removal of roots was shown to be stimulated by the range of organic acids, detergents, metals, and to be inhibited by cyanide. Superoxide production was sensitive to the addition of Mn2+ and H2O2. Increase in superoxide production correlates with the enhancement of peroxidase activity at the application of organic acids and detergents. The results obtained indicate that cell surface peroxidase is one of the main generators of superoxide in wounded wheat root cells. Different ways of stimulation of the ROS producing activity in root cells is supposed. By controlling superoxide and hydrogen peroxide formation, the cell surface peroxidase can control the adaptation processes in stressed plant cells.

Cell Membrane↗
PubMed2005

Developmental anatomy of the root cortex of the basal monocotyledon, Acorus calamus (Acorales, Acoraceae).

BACKGROUND AND AIMS: The anatomical structure and development of adventitious roots were analysed in the basal monocotyledon, Acorus calamus, to determine to what extent those features are related to phylogenetic position. METHODS: Root specimens were harvested and sectioned, either with a hand microtome or freehand, at varying distances from the root tip and examined under the microscope using a variety of staining techniques. KEY RESULTS: Roots of Acorus calamus possess a unique set of developmental characteristics that produce some traits similar to those of another basal angiosperm group, Nymphaeales. The root apical meristem organization seems to be intermediate between that of a closed and an open monocotyledonous root apical meristem organization. The open-type root apical meristem consists of a curved zone of cortical initials and epidermal initials overlying the vascular cylinder initials; the epidermal part of the meristem varies in its association with the cortical initials and columellar initials of the promeristem. The cortex develops an endodermis with only Casparian bands, a dimorphic exodermis with Casparian bands and suberin lamellae, and a polygonal aerenchyma by differential expansion, as also observed in the Nymphaeales and some dicotyledonous species. The stele has characteristics like those of members of the Nymphaeaceae. CONCLUSIONS: Specific anatomical and developmental attributes of Acorus roots seem to be related to the phylogenetic position of this genus.

Acorus↗
PubMed2005

Involvement of tumor necrosis factor-alpha in the development of T cell-dependent aortitis in interleukin-1 receptor antagonist-deficient mice.

BACKGROUND: Interleukin-1 receptor antagonist-deficient (IL-1Ra(-/-)) mice on the BALB/c background spontaneously develop inflammatory arthropathy that resembles rheumatoid arthritis in humans. These mice also frequently develop aortitis at the root of the aorta, but the mechanism underlying the development of this disease has not been completely elucidated. METHODS AND RESULTS: Using IL-1Ra(-/-) mice (backcrossed 8 generations to the BALB/c background) and wild-type mice, we studied the histopathology and examined the immunologic mechanisms involved in the development of aortic inflammation by cell transplantation experiments. Half of the IL-1Ra(-/-) mice developed aortitis at the root of the aorta, with massive infiltration of macrophages and monocytes and loss of elastic lamellae in the aortic media. Left ventricular hypertrophy and mild aortic stenosis were also shown by transthoracic echocardiography. Transplantation of T cells from IL-1Ra(-/-) mice induced aortitis in recipient nu/nu mice. Bone marrow cell transplants from IL-1Ra(-/-) mice also induced aortitis in irradiated wild-type recipient mice. Furthermore, tumor necrosis factor (TNF)-alpha deficiency completely suppressed the development of aortitis in IL-1Ra(-/-) mice, whereas IL-6 deficiency did not affect pathology. CONCLUSIONS: These observations suggest that IL-1Ra deficiency in T cells activates them excessively, resulting in the development of aortitis in IL-1Ra(-/-) mice in a TNF-alpha-dependent manner.

Animals↗
PubMed1999

Characterization of bone morphogenetic protein family members as neurotrophic factors for cultured sensory neurons.

The bone morphogenetic proteins have been implicated in several inductive processes throughout vertebrate development including nervous system patterning. Recently, these proteins have also emerged as candidates for regulating survival of mesencephalic dopaminergic and sympathetic neurons. Interestingly, we have found that several bone morphogenetic proteins can be detected in developing embryonic day 14 rat dorsal root ganglia by means of reverse transcription-polymerase chain reaction and immunocytochemistry. To further elucidate their potential role during the period of ontogenetic neuron death, serum-free cultures of dorsal root sensory neurons from developing chick and rat embryos were treated with distinct bone morphogenetic proteins with or without simultaneous addition of other "established" neurotrophic factors. Our results show that bone morphogenetic proteins exert survival promoting effects on their own, and that they can positively modulate the effects of neurotrophins on sensory neurons. In particular, growth/differentiation factor-5, bone morphogenetic protein-2, -4, -7 and -12 significantly increased the survival promoting effects of neurotrophin-3 and nerve growth factor on cultured dorsal root ganglion neurons. These results fit well into the current concept that neurotrophic factors may act synergistically in ensuring neuronal survival. Moreover, these data suggest potential instructive interactions of bone morphogentic proteins and neurotrophins during sensory neuron development. Finally, the documented neurotrophic capacity of bone morphogenetic protein family members may have potential relevance for the treatment of peripheral neuropathies.

Animals↗
PubMed2001

Development of a space radiation Monte Carlo computer simulation based on the FLUKA and ROOT codes.

This NASA funded project is proceeding to develop a Monte Carlo-based computer simulation of the radiation environment in space. With actual funding only initially in place at the end of May 2000, the study is still in the early stage of development. The general tasks have been identified and personnel have been selected. The code to be assembled will be based upon two major existing software packages. The radiation transport simulation will be accomplished by updating the FLUKA Monte Carlo program, and the user interface will employ the ROOT software being developed at CERN. The end-product will be a Monte Carlo-based code which will complement the existing analytic codes such as BRYNTRN/HZETRN presently used by NASA to evaluate the effects of radiation shielding in space. The planned code will possess the ability to evaluate the radiation environment for spacecraft and habitats in Earth orbit, in interplanetary space, on the lunar surface, or on a planetary surface such as Mars. Furthermore, it will be useful in the design and analysis of experiments such as ACCESS (Advanced Cosmic-ray Composition Experiment for Space Station), which is an Office of Space Science payload currently under evaluation for deployment on the International Space Station (ISS). FLUKA will be significantly improved and tailored for use in simulating space radiation in four ways. First, the additional physics not presently within the code that is necessary to simulate the problems of interest, namely the heavy ion inelastic processes, will be incorporated. Second, the internal geometry package will be replaced with one that will substantially increase the calculation speed as well as simplify the data input task. Third, default incident flux packages that include all of the different space radiation sources of interest will be included. Finally, the user interface and internal data structure will be melded together with ROOT, the object-oriented data analysis infrastructure system. Beyond the benefits of 'objectivity', ROOT's incorporation will also provide a graphical user interface with powerful tools for input prior to the calculation, as well as for data analysis and visualization of the results.

Computer Simulation↗
PubMed1998

RPE, a plant gene involved in early developmental steps of nematode feeding cells.

Sedentary plant-parasitic nematodes are able to induce the redifferentiation of root cells into multinucleate nematode feeding sites (NFSs). We have isolated by promoter trapping an Arabidopsis thaliana gene that is essential for the early steps of NFS formation induced by the root-knot nematode Meloidogyne incognita. Its pattern of expression is similar to that of key regulators of the cell cycle, but it is not observed with the cyst nematode. Later in NFS development, this gene is induced by both root-knot and cyst nematodes. It encodes a protein similar to the D-ribulose-5-phosphate 3-epimerase (RPE) (EC 5.1.3.1), a key enzyme in the reductive Calvin cycle and the oxidative pentose phosphate pathway (OPPP). Quantitative RT-PCR showed the accumulation of RPE transcripts in potato, as in Arabidopsis NFS. Homozygous rpe plants have a germination mutant phenotype that can be rescued in dwarf plants on sucrose-supplemented medium. During root development, this gene is expressed in the meristems and initiation sites of lateral roots. These results suggest that the genetic control of NFSs and the first stages of meristem formation share common steps and confirms the previous cytological observations which indicate that root cells undergo metabolic reprogramming when they turn into NFSs.

Amino Acid Sequence↗
PubMed2003

A simple method for obtaining cell-specific cDNA from small numbers of growing root-hair cells in Arabidopsis thaliana.

A simple and rapid method for cloning specific cDNAs from mRNA populations derived solely from small numbers of root-hair cells is described here. To identify genes expressed during the earliest visible stage of root-hair cell development, cell contents were aspirated from small numbers of Arabidopsis root-hair cells at or just before this stage. This material was used to make reusable solid-phase oligo-dT-primed cDNA libraries. To demonstrate that the libraries contained high quality longer cDNAs, a fragment located 2.7 kb from the 3' end of the cDNA of the single copy root-hair expressed gene RHD3 was cloned using a nested PCR strategy. This technique was also used to obtain novel gene expression information by cloning the full-length 0.85 kb cDNA of the Rop2 GTPase from this library. This approach offers a means of cloning larger cDNAs directly from small numbers of growing root-hair cells and, potentially, other epidermal cell types.

Arabidopsis↗
PubMed1998

Pancreatic surgery in Japan: historical review.

The advent of surgical techniques for the management of pancreatic cancer has had a long and varied history in the Western culture. The development of current surgical techniques and treatment modalities is based on (rooted in) techniques developed over time. Although the first written anecdotes of pancreatic resection--primarily from the 1600s through the late 1800s--did not alter the mortality of pancreatic cancer, they did pave the way for advances in surgical techniques that subsequently attained lower morbidity and mortality rates. Although there were some meager attempts at pancreatic resection in Japanese institutions before and during World War II, it was not until after the war, and particularly after the mid-1950s, that pancreatic surgery developed tremendously. The development of more radical approaches to pancreatic surgery developed tremendously. The development of more radical approaches to pancreatic resection as well as other surgical developments resulted in lower morbidity and mortality rates.

General Surgery↗
PubMed1973

Cholinesterases from Plant Tissues: II. Inhibition of Bean Cholinesterase by 2-Isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine Carboxylate Methyl Chloride (AMO-1618).

2-Isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride (AMO-1618) inhibits the activity of a cholinesterase isolated from mung bean (Phaseolus aureus) roots at concentrations comparable to those which retard growth and inhibit development of secondary roots of bean seedlings. Fifty per cent inhibition of the cholinesterase activity occurred at 0.21 mm. Inhibition of the cholinesterase is non-competitive and irreversible. The growth retardant seems to be a specific cholinesterase inhibitor since it has no effect on non-choline esterases.

Journal Article↗
PubMed2005

Effects of housing conditions on the development of wet skin lesions in the NOA mouse.

The effects of housing on the onset time and prevalence of wet skin lesions were investigated in NOA mice, which spontaneously develop these lesions at a high rate. Wet skin lesions developed earliest in mice that were housed individually. For mice that were housed in groups, the lesions developed earlier in mice with non-littermate group housing than in mice with littermate group housing. The prevalence of lesions was in the following order: individual housing > non-littermate group housing > littermate group housing. These results suggest that socio-psychological factors are involved in the etiology of wet skin lesions in the NOA mouse. Under individual housing conditions, two other novel characters of the NOA mouse were also observed, specifically, development of dry skin and wet skin lesions at the tail root. These characteristics developed early and with high prevalence and were easily observed on external examination. Therefore, these novel characteristics observed in NOA mice are potential markers of the psychological state of the animals.

Animals↗
PubMed1970

Effect of adenine nucleotides on levels of glycolytic intermediates during the development of induced respiration in carrot root slices.

Incubation of freshly cut carrot tissue in Na(3)ADP and Na(3)ATP promotes a marked intracellular increase in both ADP and ATP. The rapid increase in ATP during an ADP incubation and in ADP during an ATP incubation results from the activity of cytoplasmic enzyme systems upon the nucleotide absorbed into the cell from the incubation medium. There is a crossover at the pyruvate kinase reaction, but not at phosphofructokinase, when either ADP or ATP is added to freshly cut tissue. In tissue slices washed in distilled water, pyruvate kinase exhibits a negative crossover in the first 2 hours and a positive crossover between 2 and 10 hours after cutting. Cutting induces large changes in levels of nucleotides and glycolytic intermediates. There is an immediate depletion of these compounds upon cutting, so that nucleotides are added to a system where respiration rate is limited by endogenous nucleotide level. Variation in respiratory values for fresh cut tissue can be explained in terms of a range of endogenous ADP levels in different tissue batches. Nucleotide incubation experiments are discussed in relation to the provision of ADP to rate-limiting pyruvate kinase during the first phase in development of the induced respiration.

Adenine Nucleotides↗
PubMed2004

Slow degeneration of zebrafish Rohon-Beard neurons during programmed cell death.

Rohon-Beard cells are large, mechanosensory neurons located in the dorsal spinal cord of anamniote vertebrates. In most species studied to date, these cells die during development. We followed labeled Rohon-Beard cells in living zebrafish embryos and found that they degenerate slowly, over many days. During degeneration, the soma shrinks and finally disappears, and the processes become beady in appearance and finally break apart, but they do not retract. Zebrafish Rohon-Beard cells apparently fragment their DNA, as revealed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) labeling, before undergoing degenerative morphologic changes. We also followed the development of labeled dorsal root ganglion neurons, as they are developing at the same stages that Rohon-Beard cells are degenerating. We found that, although axons of both cell types extend into similar regions, Rohon-Beard cells degenerate normally in mutants lacking dorsal root ganglia, providing evidence that interactions between the two cell types are not responsible for Rohon-Beard cell degeneration. Developmental Dynamics 229:30-41,2004.

Animals↗
PubMed2000

Mechanosensitive chloride channels on the growth cones of cultured rat dorsal root ganglion neurons.

We developed an experimental system to investigate mechanosensitivity of a single neuron, using cultured rat dorsal root ganglion cells. Highly precise mechanical stimulation was applied to various sites of the cells, using a piezo-driven glass microcapillary whose movement was computer-controlled, while whole-cell patch-clamp recordings were made from the cell bodies. When the growth cones and lamillipodia from the cell soma were mechanically stimulated, inward currents were recorded at the holding potential of -60mV. Filopodia were most sensitive to mechanical stimulation. However, when neurites or soma of dorsal root ganglion cells were stimulated in the same way, electrical responses were hardly recorded. Two types of currents varying in time-course were observed: fast type of 100-200ms and slow type of several seconds in duration. When the membrane potential was held at around 0mV, both types of currents were almost abolished or even reversed, and the reversal potential was estimated to be about -2. 2mV. Replacement of extracellular sodium by tetraethylammonium did not significantly change the reversal potential. In the low-chloride solution ([Cl(-)](o)=11.7mM), the reversal potential was about +60mV, as expected from the Nernst equation for chloride. These inward currents were almost completely inhibited by extracellular application of chloride channel blocker, 5-nitro-2-(3-phenylpropylamino) benzoic acid (100microM). These results indicate that the inward currents are due to activation of mechanosensitive chloride channels, preferentially located on the growth cones of cultured dorsal root ganglion neurons.

Animals↗