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PubMed1995

Promoter analysis of the auxin-regulated tobacco glutathione S-transferase genes Nt103-1 and Nt103-35.

We have analysed the promoter regions of two closely related auxin-regulated glutathione S-transferase genes. All active deletion constructs tested showed expression of the reporter gene beta-glucuronidase (gusA) in root tips of young seedlings and newly developing lateral roots. Auxin treatment greatly enhanced the level of expression. The Nt103-1 promoter region -370/-276 was found to be necessary, at least as a quantitative element to confer auxin-responsiveness to a reporter gene, and sequences responsible for the auxin-responsiveness must be located downstream of -370. The region -651/-370 contains sequence information necessary for uninduced expression. The Nt103-35 promoter manifested its auxin-responsiveness within the -504/-310 region. Electrophoretic mobility shift analysis, using nuclear extracts from tobacco leaves and suspension cells, identified a factor binding to a sequence (ap103, TGAGTCT) at position -560 of the Nt103-1 promoter, which shows homology to the mammalian AP-1 site. A second factor was found to bind a sequence (as103, ATAGCTAAGTGCTTACG) with homology to the CaMV 35S promoter as-1 element. The as103 element is present in both promoters and positioned around -360, so within the region determined to be indispensable for the response to auxin. A third factor was found binding to the -276/-190 region of both promoters. Combined, these data point to the relevance of a 90 bp region for auxin-induced activity of both tobacco genes. The ASF-1 like factor binding to the as103 element within this region might be involved in mediating the auxin response.

Base Sequence↗
PubMed2001

Efficient production of saikosaponins in Bupleurum falcatum root fragments combined with signal transducers.

An efficient system to produce saikosaponins (saikosaponin-a and -d) in Bupleurum falcatum adventitious root fragments combined with signal transducers was developed. The roots are heterogeneous in terms of size and shape and sometimes form aggregates during cultivation. When the roots were cut to lengths of about 5 mm using a scalpel and cultivated, the root fragments did not form the aggregates, and root growth and saikosaponin production were not inhibited. After screening various signal transducers, it was clear that methyl jasmonate (MeJA) markedly promoted saikosaponin production. By comparing the effect of MeJA and related substances on saikosaponin production, we conclude that both the pentenyl and carboxylmethyl group of MeJA play an important role in the promotion of saikosaponin production. Addition of both 100 microM MeJA and 20 mM CaCl2 to the medium stimulated the content of saikosaponin in the root, with levels reaching 31.7 mg/g-dry root for 15 days of cultivation. A large amount of root fragments were prepared using a blender and cultivated (23 g-dry root/l) with 400 microM MeJA and 20 mM CaCl2, resulting in a high concentration of saikosaponins (747.3 mg/l).

Acetates↗
PubMed2001

Annuloaortic repair in the treatment of aortic regurgitation and aortic root pathology.

We developed a new technique of aortic root repair which may be able to eliminate the potential problem of leaflet damage, resulting from the direct contact of the aortic leaflets with synthetic vascular grafts during systole. This report describes our technique of annuloaortic repair and the operative results. Between February 1995 and October 1998, 13 patients underwent annuloaortic repair. The patients included 8 males and 5 females (mean age 50 years). Four patients had grade IV/IV aortic regurgitation (AR), 5 had III/IV AR, 2 had II/IV AR, and 1 had no AR preoperatively. Regarding the preoperative functional status, 1 patient was classified as New York Heart Association class IV, 5 were class III, 6 class II, and 1 class I. Concomitant cardiovascular procedures were performed in 12 cases. Aortic valvuloplasty or annuloplasty was performed in 7 patients. Both operative and short-term postoperative results with pre- and postoperative echocardiographic findings were studied retrospectively. The mean total cardiopulmonary bypass time was 212 min. The mean aortic cross-clamp time was 130 min. Circulatory arrest was induced in 5 patients. Postoperatively, 7 patients had no AR. Three patients had grade I/IV AR and 3 had grade II/IV AR. Perioperative changes in aortic annulus, mid-sinus portion, and sinotubular junction diameters were determined echocardiographically in 5 patients. The preoperative diameters were 2.7 +/- 0.4, 5.4 +/- 0.5, and 4.7 +/- 1.0 cm, respectively. The postoperative diameters were 2.3 +/- 0.5, 4.2 +/- 0.5, and 3.5 +/- 0.5cm, respectively. Ten patients were class I and 2 were class II. This technique of annuloaortic repair with or without aortic valvuloplasty is applicable to a certain subset of patients with aortic root disease and AR. Both the indications for this procedure and the long-term results should be confirmed.

Adolescent↗
PubMed1990

Toward a durable and safe aortic root reconstruction.

The development of acceptable and durable aortic root operations has been interesting. With trial and error there has been a progressive intrusion on the aortic valve and coronary arteries. Many surgeons have contributed to this progression, with the final step being taken by Dr Bentall in 1968. Since that time has come a gradual application of this more complete operation and a better understanding of its advantages.

Aorta↗
PubMed2005

Russulaceae and Thelephoraceae form ectomycorrhizas with members of the Nyctaginaceae (Caryophyllales) in the tropical mountain rain forest of southern Ecuador.

* Three members of the Nyctaginaceae, two Neea species and one Guapira species, occurred scattered within a very species-rich neotropical mountain rain forest. The three species were found to form ectomycorrhizas of very distinctive characters, while all other tree species examined formed arbuscular mycorrhizas. * The ectomycorrhizas were structurally typified according to light and transmission electron microscope investigations. The internal transcribed spacer (ITS) rDNA and part of the nuclear large subunit (LSU, 28S) rDNA of the mycorrhiza forming fungi were amplified and sequenced. Phylogenetic analyses were carried out. * Neea species 1 was found to form typical ectomycorrhizas with five different fungal species, Russula puiggarii, Lactarius sp., two Tomentella or Thelephora species, and one ascomycete. Neea species 2 and the Guapira species were associated with only one fungus each, a Tomentella/Thelephora species clustering closely together in an ITS-neighbour-joining tree. The long and fine rootlets of the Guapira species showed proximally a hyphal mantle and a Hartig net, but distally intracellular fungal colonization of the epidermis and root hair development. The ectomycorrhizal segments of the long roots of Neea species 2 displayed a hyphal mantle and a Hartig net around alive root-hair-like outgrowths of the epidermal cells. * The distribution and the evolution of ectomycorrhizas in the predominantly neotropic Nyctaginaceae are discussed.

Ascomycota↗
PubMed1982

The treatment of trigeminal neuralgia by posterior fossa microsurgery.

Between 1972 and 1981 57 patients underwent posterior fossa exploration in Oxford by a single surgeon for the treatment of trigeminal neuralgia. Fifty-four of these had either partial or total section of the trigeminal sensory root, 2 had microvascular decompression operations and one had both a partial sensory root section and microvascular decompression. There was no mortality and no significant morbidity. Fifty-four patients were followed up for a mean period of 4 . 5 years. Fifty-two patients (96%) had either no further pain or only minor twinges requiring no further treatment. Two other patients who had partial sections suffered no further trigeminal neuralgia after subsequent total sections. One patient who had a partial root section developed anaesthesia dolorosa and one who had a microvascular decompression developed painful dysaesthesia. All patients having partial root sections retained previously intact corneal responses--the sensory impairment in the face corresponded to the appropriate part of the portio major cut. Only 11% of patients were found to have a vascular abnormality.

Adult↗
PubMed1997

Structural requirements of Rhizobium chitolipooligosaccharides for uptake and bioactivity in legume roots as revealed by synthetic analogs and fluorescent probes.

Rhizobium chitolipooligosaccharides (CLOSs) are heterogeneous fatty acylated N-acetyl glucosamine oligomers with variations in both the polar (hydrophilic) oligosaccharide head group and the non-polar (hydrophobic) fatty acyl chain. They trigger root hair deformation and cortical cell divisions in legume roots during development of the nitrogen-fixing root-nodule symbiosis. It has been proposed that only certain unique molecular species of CLOSs made by a particular rhizobia can elicit these responses on the corresponding legume host, suggesting that receptor-mediated perception of CLOSs serves as a basis of symbiotic specificity. We evaluated the relative symbiotic importance of the hydrophilic and hydrophobic structural domains of CLOSs by comparing the biological activities of CLOSs from wild type R. leguminosarum bv. trifolii ANU843 with that of various synthetic analogs. These tests were performed in axenic bioassays on the compatible symbiotic host, white clover (Trifolium repens) and the incompatible non-host legume, alfalfa (Medicago sativa). Fluorochrome-tagged derivatives of the native CLOSs and the analogs were also prepared in order to evaluate the uptake and localization patterns of these molecules within host root cells. The results indicate a direct link between uptake and biological activities of Rhizobium CLOSs on legume roots. The smallest CLOS analog taken up and biologically active on white clover and alfalfa was a N-fatty acylglucosamine, without an essential requirement of oligomerization, fatty N-acyl unsaturation, or acetate/sulfate functionalization. This suggests that N-fattyacylglucosamine is the common minimum structure required and sufficient for uptake and biological activity of CLOS glycolipids in these legumes, and that the various specific modifications of its polar head group and hydrophobic tail modulate its inherent ability to further express these activities, thus influencing which legumes are capable of responding to CLOSs rather than dictating their biological activities per se.

4-Chloro-7-nitrobenzofurazan↗
PubMed2000

Ozone impacts on allometry and root hydraulic conductance are not mediated by source limitation nor developmental age.

O(3)could reduce growth and carbohydrate allocation to roots by direct inhibition of photosynthesis and source strength. Alternatively, O(3) could reduce growth indirectly by inhibition of root hydraulic development through a primary lesion in carbohydrate translocation. Another alternative is that O(3) could slow the rate of plant development, only apparently altering carbohydrate allocation at a given plant age. Pima cotton (Gossypium barbadense L.) is used to address these possibilities, and four hypotheses were tested/ (1) O(3) exposure reduces leaf pools of soluble sugars; (2) pruning leaf area and reducing source strength to match that of O(3)-treated plants reproduces O(3)-effects; (3) pruning lower leaf area more closely reproduces O(3) effects than pruning upper leaf area; and (4) manipulating plant age and thereby plant size to match O(3)-treated plants reproduces O(3)-effects. All were falsified. Soluble sugars did not decline. Pruning upper and lower leaves and manipulating plant age all reduced biomass and leaf area similarly to O(3)-exposure, but neither reproduced O(3) effects on biomass allocation nor root function. It is concluded that O(3) induces an allometric shift in carbohydrate allocation that is not mediated by photosynthetic inhibition nor by alteration of developmental age. Effects of O(3) could be mediated by direct effects on phloem loading, with consequent inhibition of translocation to roots and root system development.

Biomass↗
PubMed1990

Electronic determination of root canal length by newly developed measuring device. Influences of the diameter of apical foramen, the size of K-file and the root canal irrigants.

A new electronic root canal measuring device called "ENDEX" which is able to determine the root canal length under moistened conditions using a relative value of different alternative electric currents is discussed in this study. This study is designed to investigate the efficiencies of the new device, in vitro, with respect to change in the root canal environment; namely the influence of the size of K-file, the diameter of the apical foramen and the various root canal irrigants. According to the present study, it was confirmed that the location of the apical foramen was clearly detected under moistened root canal with saline solution using any size of K-file. The locations of the tip of K-files were 0.5 mm inside the apical foramen when the relative value displayed 0.3 Volt, so that the apical constriction could not disturb during root canal measurement. One of the big problem with prior electrical measurement devices was not being able to determine the canal length under moistened conditions. However with this improved device, intracanal irrigants, such as saline, 5% NaOC1, 14% EDTA and 3% H2O2 did not interfere in detecting apical foramen irregardless of the size of K-file and the size of the apical foramen.

Dental Pulp Cavity↗
PubMed1990

Somatotopic organization in the sensory innervation of the rat hindlimb during development, using half dorsal root ganglia as subsegmental units.

The aim of the present study was to determine the somatotopy of the sensory innervation of the rat hindlimb at the level of the dorsal root ganglia (DRGs) during the fetal and postnatal period. Injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) were made into the hindlimb of fetal and postnatal rats. These injections result in completely and partially labeled DRGs. Partial labeling always concerns the rostral or caudal half of a DRG. Using half DRGs as subsegmental units, a description is given of a somatotopic organization of the sensory innervation of the rat hindlimb during development.

Animals↗
PubMed2005

Role of Thy-1 in in vivo and in vitro neural development and regeneration of dorsal root ganglionic neurons.

We have examined the expression of Thy-1, an abundant glycosylphosphatidylinositol (GPI)-anchored glycoprotein, in dorsal root ganglia (DRG) and associated nerve fascicles, during postnatal development and following a nerve crush. The expression levels of Thy-1 in DRG neurons, dorsal roots, and central processes in spinal cord were rather low at postnatal day 2, and gradually increased as DRG neurons matured. During early development, the expression of Thy-1 within DRG neurons was low and equally distributed between plasma membrane and cytosol. With maturation, the staining intensities of Thy-1 in both the plasma membrane and the cytosol of DRG neurons became increased. We also studied Thy-1 expression in the regeneration of mature DRG neurons following the crush injury of sciatic nerve. Two days after the crush injury, Thy-1 expression dramatically decreased in the DRG neurons on the lesion side. Between 4 and 7 days after the injury, the expression of Thy-1 gradually increased and returned to a normal level 1 week after the sciatic nerve crush. The time course of the up-regulation of Thy-1 expression during regeneration matched that of the recovery of sensory functions, such as pain withdraw reflex, placing reflex, and the score of Basso-Beattie-Bresnahan Locomotor Rating Scale. Taken together, our results suggest that Thy-1 expression is developmentally regulated and is closely associated with the functional maturation of DRG neurons during both postnatal development and nerve regeneration. Furthermore, perturbation of Thy-1 function with anti-Thy-1 antibodies promoted neurite outgrowth from primary cultured DRG neurons, again confirming the inhibitory role of Thy-1 on neurite outgrowth.

Animals↗
PubMed1995

Structural organization and differential expression of carrot beta-fructofuranosidase genes: identification of a gene coding for a flower bud-specific isozyme.

Three genomic clones (Inv*Dc1, Inv*Dc2 and Inv*Dc3) were isolated by using the cDNA for carrot cell wall beta-fructofuranosidase as a probe. The expression patterns of the three genes differed markedly. High levels of Inv*Dc1 transcripts were found in leaves and roots of young carrot, whereas in plants with developing tap roots no transcripts were detected. A high level of mRNA of Inv*Dc1 was also present in suspension-cultured cells. In developing reproductive organs, only low levels of transcripts of Inv*Dc1 were found in flower buds and flowers and none at later stages of development. In contrast, Inv*Dc2 and Inv*Dc3 were not expressed in vegetative plant organs. Invb1*Dc1 was exclusively and strongly expressed in flower buds, and Inv*Dc3 at a very low level in suspension-cultured cells.

Amino Acid Sequence↗
PubMed2001

Early development of rat ventral root transitional zone: an immunohistochemical and morphometric study.

Bundles of ventral motoneuron axons cross the white matter of the spinal cord, emerge through the cord surface at the CNS-PNS transitional zone (TZ) and continue in the PNS as ventral rootlets. This study identifies immunohistochemical and morphometric changes which characterise the key events in early TZ formation in the rat. E18 is a landmark stage, since it is then that the major events of TZ differentiation are initiated. In the glial processes associated with the TZ, vimentin expression decreases, while that of GFAP increases. In the proximal rootlets the transient expression of CNS markers such as GFAP and of neural adhesion molecules such as HNK-1/N-CAM begin to decrease. Their resulting differential expression clearly defines the CNS-PNS interface. These changes coincide with the arrival of glial nuclei at the TZ. Cell clusters which appear on proximal ventral rootlet surfaces shortly after their emergence from the cord, have by E18 formed an extensive matrix of processes which segregates the axon bundle. This comprises the earliest of two well-defined barriers across the axon bundle. An important function may be to prevent Schwann cell invasion of the cord. Cluster cells display some immunohistochemical features in common with Schwann cells. The second barrier becomes fully established only at P2 and forms the definitive CNS-PNS interface. It consists of processes arising from astrocytes surrounding the TZ. Changes in the nuclear density of the cell types correspond closely to their segregating activity. The immunohistochemical and ultrastructural changes complement one another to deepen and enhance understanding of TZ development.

Animals↗
PubMed1999

ZmOCL1, an HDGL2 family homeobox gene, is expressed in the outer cell layer throughout maize development.

The formation of a morphologically distinct outer cell layer or protoderm is one of the first and probably one of the most important steps in patterning of the plant embryo. Here we report the isolation of ZmOCL1 (OCL for outer cell layer), a member of the HDGL2 (also known as HD-ZIP IV) subclass of plant-specific HD-ZIP homeodomain proteins from maize. ZmOCL1 transcripts are detected very early in embryo development, before a morphologically distinct protoderm is visible, and expression then becomes localised to the protoderm of the embryo as it develops. Subsequently, expression is observed in the L1 cell layer of both the developing primary root and shoot meristems, and is maintained in developing leaves and floral organs. We propose that ZMOCL1 may play a role in the specification of protoderm identity within the embryo, the organisation of the primary root primordium or in the maintenance of the L1 cell layer in the shoot apical meristem. We also show that the expression of ZmOCL1 is different from that of another epidermal marker gene, LTP2 (lipid transfer protein) and, in meristems, is complementary to that of Kn1 (Knotted) which is transcribed only in underlying cell layers.

Amino Acid Sequence↗
PubMed1978

Proliferative and degenerative events in the early development of chick dorsal root ganglia. II. Responses to altered peripheral fields.

Responses of chick embryo dorsal root ganglia to early wing bud amputation were examined histologically using tritiated thymidine (3H-TdR) and autoradiography to analyze proliferation and the Feulgen procedure to visualize degenerating cells. Right wing buds were amputated at stage 15 or 16. At 4.5 to 9.5 days of incubation embryos were given a 1-hour exposure to 3H-TdR and fixed. Feulgen-stained autoradiographs were examined for percentage of cells labelled (labelling index) or degenerating (degeneration index) in lateroventral (LV) and mediodorsal (MD) regions of brachial (G14-16) and nonbrachial (G12, 13, 17) ganglia. The earliest response to amputation was a highly significant increase in degeneration indices of LV and MD regions of ipsilateral brachial ganglia at 5.5 days. Significant brachial LV responses were observed throughout the remainder of the experimental period. Two peaks occur in this response: at 5.5 days, corresponding to the peak seen in normal nonbrachial ganglia, and at 8.5 days, having no counterpart in normal development. In brachial MD regions significant degenerative responses occur at most times examined. Significant responses also occur at 7.5 and 8.5 days in MD regions of nonbrachial ganglia. The presence of MD responses in our material indicates that maturation of at least some MD neurons occurs earlier than previously thought. Significant labelling responses occur in brachial LV regions from 7.5 days on. Because other studies (Carr and Simpson, '78a) show that this time is after the end of large-scale neuronal production, this labelling response must be nonneuronal in nature. We conclude that this response is a secondary response to amputation, consequent to the greatly increased cellular degeneration. Results of experiments involving addition of limb buds at the brachial level are also presented.

Amputation, Surgical↗
PubMed2003

Analysis of the feed-forward effects of sink activity on the photosynthetic source-sink balance in single-rooted sweet potato leaves. I. Activation of RuBPcase through the development of sinks.

Single-rooted sweet potato leaves having a petiole with a fragment of stem allocated exceptionally large amounts of photosynthates to tuberous roots, the only major storage organ, throughout an experimental period of 50 d. The increase in photosynthetic activity for CO(2) fixation depended exclusively on the development of sink activity due to the growth of tuberous roots. Thus this model expressed a remarkable feed-forward effect on the photosynthetic source-sink balance. The level of ribulose-1,5-bisphosphate carboxylase (RuBPcase) protein in the leaves increased continuously during the period. The lowered initial as well as total activity of RuBPcase observed at the start of the experiment was raised with the cancellation of the sink-limited state due to the development of tuberous roots. The maximum activity determined after removing some inhibitor(s) from the enzyme by treating the leaf extract with SO(4)(2-) was much greater than the total activity and remained approximately constant throughout the experimental period. The clear decrease in the difference between maximum and total activities with the development of tuberous roots might reflect the reactivation of RuBPcase due to the removal of some inhibitor(s) from the enzyme through the cancellation of the sink-limited state.

Carbohydrate Metabolism↗
PubMed1983

Dorsal root afferents contact migrating motoneurons in the developing frog spinal cord.

Dorsal and ventral roots of Rana catesbeiana tadpole lumbar spinal cord were labeled with horseradish peroxidase during development of the hindlimb. Labeled motoneurons in the process of migrating were found in the region of the developing terminal arbors of dorsal root axons. Electron microscopy showed that some of these dorsal root terminals contacted the migrating motoneurons.

Afferent Pathways↗
PubMed1985

The possible modulation of the development of rat dorsal root ganglion cells by the presence of 5-HT-containing neurones of the brainstem in dissociated cell culture.

Reliable methods for coculturing dissociated rat brainstem cells together with dorsal root ganglion (DRG) cells have been established. The cells were characterized using autoradiographic, morphological, immunocytochemical and electrophysiological techniques. Light-level microscopy showed the cocultures to be extensively invaded by serotonin (5-HT)-containing neuronal processes and intense clustering of 5-HT-containing varicosities to occur in the vicinity of large round phase-bright neurones thought to be DRGs. Rather extensive fine ramification of the neuronal processes throughout the culture dish were visualized using scanning electron microscopy. Intracellular recording showed the brainstem neurones to be spontaneously active, electrically excitable and sensitive to a variety of transmitter candidates including serotonin (5-HT) and gamma-aminobutyric acid. Several different responses to 5-HT have been observed. These include a depolarization accompanied by an increase in membrane resistance, a depolarization accompanied by a decrease in membrane resistance and a hyperpolarization accompanied by an increase in membrane resistance. As established by others, DRG cells grown in isolation were always quiescent. The application of 5-HT produced no effect on membrane potential, resistance or excitability. In the brainstem-DRG cocultures 52% of DRG cells exhibited synaptic activity and occasional spontaneous spiking, both of which were abolished in the presence of tetrodotoxin or low-Ca2+/high-Mg2+ solution. Transmission electron microscopy confirmed the presence of synapses on the DRG cells. The spontaneously active DRG cells were also found to be sensitive to the application of 5-HT. Thus it appears that a source of 5-HT nerve terminals may regulate the development and pharmacological sensitivity of primary afferent neurones in culture.

Acetylcholine↗