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1.
Zhijian Li Abdoulaye Traore Siela Maximova Mark J. Guiltinan 《In vitro cellular & developmental biology. Plant》1998,34(4):293-299
Summary A procedure for the regeneration of cacao (Theobroma cacao) plants from staminode explants via somatic embryogenesis was developed. Rapidly growing calli were induced by culturing
staminode explants on a DKW salts-based primary callus growth (PCG) medium supplemented with 20 g glucose per L, 9 μM 2,4-D, and thidiazuron (TDZ) at various concentrations. Calli were subcultured onto a WPM salts-based secondary callus growth
medium supplemented with 20 g glucose per L, 9 μM 2,4-D, and 1.4 nM kinetin. Somatic embryos were formed from embryogenic calli following transfer to a hormone-free DKW salts-based embryo development
medium containing sucrose. The concentration of TDZ used in PCG medium significantly affected the rate of callus growth, the
frequency of embryogenesis, and the number of somatic embryos produced from each responsive explant. A TDZ concentration of
22.7 nM was found to be the optimal concentration for effective induction of somatic embryos from various cacao genotypes. Using
this procedure, we recovered somatic embryos from all 19 tested cacao genotypes, representing three major genetic group types.
However, among these genotypes, a wide range of variation was observed in both the frequency of embryogenesis, which ranged
from 1 to 100%, and the average number of somatic embryos produced from each responsive explant, which ranged from 2 to 46.
Two types of somatic embryos were identified on the basis of their visual appearance and growth behavior. A large number of
cacao plants have been regenerated from somatic embryos and established in soil in a greenhouse. Plants showed morphological
and growth characteristics similar to those of seed-derived plants. The described procedure may allow for the practical use
of somatic embryogenesis for clonal propagation of elite cacao clones and other applications that require the production of
a large number of plants from limited source materials. 相似文献
2.
Taizo Hogetsu 《Planta》1991,185(2):190-200
Arrangements of microfibrils (MFs) and microtubules (MTs) were examined in tracheary elements (TEs) of Pisum sativum L. and Commelina communis L. by production of replicas of cryo-sections, and by immunofluorescence microscopy, respectively. The secondary wall thickenings of TEs of Pisum and Commelina roots have pitted and latticed patterns, respectively. Most MFs in the pitted thickening of Pisum TEs retain a parallel alignment as they pass around the periphery of pits. However, some groups of MFs grow into the pits but then terminate at the edge of the thickening, indicating that cellulose-synthase complexes are inactivated in the plasma membrane under the pit. Microtubules of TEs of both Pisum and Commelina are localized under the secondary thickening and few MTs are detected in the areas between wall thickenings. In the presence of the MT-disrupting agent, amiprophosmethyl, cellulose and hemicellulose, which is specific to secondary thickening, are deposited in deformed patterns in TEs of Pisum roots, Pisum epicotyls and Commelina roots. This indicates that the localized deposition of hemicellulose as well as cellulose involves MTs. The deformed, but heterogeneous pattern of secondary thickening is still visible, indicating that MTs are involved in determining and maintaining the regular patterns of the secondary thickening but not the spatial heterogeneous pattern of the wall deposition. A working hypothesis for the formation of the secondary thickening is proposed.Abbreviations APM
amiprophosmethyl
- DMSO
dimethyl sulfoxide
- F-WGA
fluorescein-conjugated wheat-germ agglutinin
- M F
microfibril
- MT
microtubule
- PEG
polyethyleneglycol
- TE
tracheary element
I thank Ms. Aiko Hirata (Institute of Applied Microbiology, University of Tokyo, Japan) for help in taking stereomicrographs. This work was supported in part by a Grant-in-Aid from the Ministry of Education, Science and Culture of Japan. 相似文献
3.
Al-Hussain Bani Hani SM El-Dwairi QA Bataineh ZM Al-Haidari MS Al-Alami J 《Cellular and molecular neurobiology》2008,28(3):411-416
The morphological and quantitative features of neurons in the adult human ventral anterior thalamic nucleus were studied in
Golgi preparations. Two neuronal types were found and their quantitative features were studied. Golgi-type I neurons were
medium to large cells with dense dendritic trees and dendritic protrusions and short hair-like appendages. They have somatic
mean diameter of 30.8 μm (±9.4, n = 85). They have an average 100.3 dendritic branches, 48.97 dendritic branching points, and 58.85 dendritic tips. The mean
diameters of their primary, secondary, and tertiary dendrites were 3.1 μm (±1, n = 80), 1.85 μm (±0.8, n = 145), and 1.5 μm (±0.4, n = 160), respectively. Golgi-type II neurons were small to medium cells with few sparsely branching dendrites and dendritic
stalked appendages with or without terminal swellings. They have somatic mean diameters of 22.2 μm (±5.8, n = 120). They have an average 33.76 dendritic branches, 16.49 dendritic branching points, and 21.97 dendritic tips. The mean
diameters of their primary, secondary, and tertiary dendrites were 1.6 μm (±0.86, n = 70), 1.15 μm (±0.55, n = 118), and 1 μm (±0.70, n = 95), respectively. These quantitative data may form the basis for further quantitative studies involving aging or some
degenerative diseases that may affect cell bodies and/or dendritic trees of the Golgi-type I and/or Golgi-type II thalamic
neurons. 相似文献
4.
R. Whitkus M. de la Cruz L. Mota-Bravo A. Gómez-Pompa 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(5):621-627
Neotropical tree crops are affected by a combination of biological and human factors that complicate the study of genetic
diversity and crop evolution. Genetic diversity and relationships among southern Mexican populations and horticultural collections
of Theobroma cacao (chocolate, cocoa, cacao) are examined in light of the agricultural practices of the Maya. Collections of cacao were obtained
from the extremes of its geographic range including archeological sites in southern Mexico where cacao was first domesticated.
Genetic diversity was assayed by 57 informative random amplified polymorphic DNA (RAPD) marker loci. A unique sample of the
total diversity found in this study exists in the southern Mexican populations. These populations are significantly different
from all other cacao with regards to their profile of RAPD bands, including the ‘criollo’ variety, their morphological and
geographical group. A population of cacao found in a sinkhole (cenote) in northern Yucatan with genetic affinities to populations
in Chiapas suggests the Maya maintained plants far away from their native habitat. This finding concurs with known agroforestry
practices of the Maya. Modern efforts to increase germplasm of tropical tree crops such as cacao should carefully examine
archeological sites where genetic diversity, either deliberately or by chance, was collected and maintained by ancient cultures.
Received: 21 May 1997 / Accepted: 9 October 1997 相似文献
5.
Chow-Chin Tong Yew-Keong Choong Nor-Aini-B Umar Mohamed-Mustapha Noordin Suhaila Mohamed 《World journal of microbiology & biotechnology》2009,25(4):687-695
Ganoderma lucidum powder using hot water and methanol extraction methods indicated a twofold more active cytotoxic activity with IC50 of 44 ± 3.8 μg/ml in the latter method. The representative dose-response curves of the G. lucidum crude extracts on J558 cell-lines revealed that there were great similarities between the curves which reflected rapid killing
activities. The percentage viability of the J558 cell exposed to these crude extracts was dose dependent only up to 150 μg/ml.
After which, there was no significant reduction when the dose was increased to 200 or 400 μg/ml. The morphological alterations
induced by the crude extract were examined under the phase contrast, fluorescent and electron microscopy. When J558 cells
were treated with doses higher than 50 μg/ml of the crude extract, obvious morphological changes and apoptosis occurred after
72 h. At 400 μg/ml, most of the cells showed necrosis characterized as small fragments with uniformly stained red nuclei.
The apoptotic and necrotic cells increased by 16.5 and 29.1%, respectively whereas the viable cells decreased by as much as
45.6. The mode of cell death via apoptosis was 3.6% higher than necrosis. However, these morphological changes were not observed
in the case of 3T3 cells. Results obtained from scanning electron microscopy and transmission electron microscopy further
confirmed the occurrence of various apoptotic and necrotic features. 相似文献
6.
Morphological and Genetic Characterization of <Emphasis Type="Italic">Saimiri boliviensis</Emphasis>
Eliana Ruth Steinberg Mariela Nieves Marina Sofía Ascunce Ana María Palermo Marta Dolores Mudry 《International journal of primatology》2009,30(1):29-41
The taxonomy of Saimiri is controversial because morphological characteristics, traditionally used for identification, are insufficient to distinguish
species and subspecies. Genetic studies of specimens become relevant for captive management, especially considering their
frequently unknown geographical origin. We analyzed phenotypic and genetic parameters in Saimiri spp. in Argentinean zoological gardens and biological stations to provide a more accurate taxonomic identification. We studied
27 males and 19 females of Saimiri spp. The cytogenetic analysis in mitotic metaphases corroborated a modal number of 2N = 44, XX/XY, and FN = 75 for males
and FN = 76 for females. G- and C-bands, fluorescence in situ hybridization (FISH) and the pelage coloration pattern of all the specimens corresponded to Saimiri boliviensis boliviensis. We characterized for the first time the sperm cell morphology and morphometry (mean ± SE): total length: 71.39 ± 5.40 μm;
head length: 5.71 ± 0.81 μm; head width: 3.76 ± 0.70 μm; acrosome length: 3.70 ± 0.82 μm; midpiece length: 12.20 ± 2.22 μm.
Researchers can use the characterization of the sperm morphology as another parameter for taxonomic identification that, together
with cytogenetic and molecular ones, would allow a more precise identification of individual Saimiri boliviensis boliviensis. 相似文献
7.
We examined morphological and ultrastructural differences in chloroplasts of cotton leaves and the fruiting organs, bract,
and capsule wall to advance our understanding of their commonly observed differences in photosynthetic efficiency. Chloroplasts
from leaves were large (7.1 μm long in cross section), lens shaped with a well developed membrane system differentiated into
grana and stroma lamellae that occupied the large cross-sectional area (12.3 μm2) of the organelle. A few small plastoglobuli and starch grains were scattered in the stroma region. The bract chloroplasts
were correlative of leaf chloroplasts in size (6.8 μm in length) and shape with the exception that the bract chloroplasts
exhibited greater thylakoid number per granum (15.8) than the leaf chloroplasts (10.5). In contrast to leaf and bract, the
capsule wall chloroplasts were smaller in size (4.3 μm) and cross sectional area (6.8 μm2) than either the leaf or bract. The most intriguing feature of the capsule wall chloroplasts was its domination by large
starch granules (5.3 μm2) in the stroma which filled the whole chloroplast coercing the membrane system to move towards the periphery of the organelle.
Grana number and thylakoids per granum were lowest in the capsule wall chloroplasts.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Genotypic variation in photosynthesis in cacao is correlated with stomatal conductance and leaf nitrogen 总被引:1,自引:0,他引:1
Variation in photosynthetic parameters was observed between eight contrasting cacao (Theobroma cacao) genotypes. Net photosynthetic rate (PN) ranged from 3.4 to 5.7 μmol(CO2) m−2 s−1 for the genotypes IMC 47 and SCA 6, respectively. Furthermore, genotypic differences were detected in quantum efficiency
ranging from 0.020 to 0.043 μmol(CO2) μmol−1(photon) for UF 676 and AMAZ 15/15, respectively. Differences in PN were correlated with both stomatal conductance (gs) and leaf nitrogen per unit area. Some variation in water use efficiency was observed between genotypes, both intrinsic (PN/gs) and instantaneous (PN/transpiration rate). Both measures of water use efficiency were a negative function of specific leaf area. Evidence was found
for a trade-off mechanism between cacao genotypes in photosynthesis and leaf structure. High photosynthetic rate, expressed
on a mass basis was associated with smaller leaves. Furthermore, thinner leaves were compensated for by a higher nitrogen
content per unit mass. 相似文献
9.
Ampullary organs of Euristhmus lepturus occur in high densities along the head and in four parallel pathways along the trunk of the body. Large ampullary pores (125–130 μm)
are easily distinguishable from other sensory epithelial pores due to the differences in size and the presence of a collar-like
structure. Simple, singular ampullary organs of the head region consist of an ampullary pore connected to a long canal with
a diameter of 115–175 μm before terminating as a simple ampulla with an external diameter of 390–480 μm. The ampullary canal
is composed of 1–2 layers of flattened squamous epithelial cells, the basement membrane and an interlocking collagen sheath.
The innermost cells lining the canal wall are adjoined via tight junctions and numerous desmosomes, as are those of the receptor
and supportive cells. Canal wall tissue gives rise to a sensory epithelium containing between 242 and 285 total receptor cells,
with an average diameter of 11.7 ± 5.3 μm, intermixed with medially nucleated supportive cells. Each receptor cell (21.38 ± 4.41 μm,
height) has an apically positioned nucleus and a luminal surface covered with numerous microvilli. Neural terminals abut the
basal region of receptor cells opposite multiple presynaptic bodies and dense mitochondria. Supportive cells extend from the
ampullary lumen to the basement membrane, which is adjacent to the complex system of collagen fibres. 相似文献
10.
Somatic embryos were induced on roots excised from in vitro plants of Prunus avium× pseudocerasus `Colt'. On medium containing 6-benzylamino purine (BAP, 1.5 μM) and 2,4-dichlorophenoxyacetic acid (2,4-D, 15 μM), a mean
of 25 (s.e. ± 2.0) somatic embryos were produced on intact root systems and 15 (s.e. ± 1.7) on roots systems cut into 10 mm
pieces. Most somatic embryos were formed directly on intact roots and indirectly (from callus) on sectioned roots. A mean
of 2.5 (s.e. ± 0.25) secondary embryos per primary embryo were formed directly on primary embryos after they were transferred
to medium containing BAP (1.5 μM), indole-3-butyric acid (10 μM) and 2,4-D (5 μM). After transfer to a medium containing BAP
(2 μM) and gibberellic acid (GA3, 3 μM), shoots developed in 75% (s.e. ± 7.3) of the embryos. Somatic embryos were not induced on explants of in vitro roots or shoots of P. avium, and were induced infrequently on zygotic embryos, although a wide range of media were tested. Possible reasons for the contrasting
embryogenic ability of `Colt' and P. avium are discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
11.
Total synaptonemal complex (SC) lengths were estimated from Oreochromis aureus Steindachner (which has a WZ/ZZ sex determination system), O. mossambicus Peters and O. niloticus L. (both of which have XX/XY sex determination systems). The total SC length in oocytes was greater than that in spermatocytes
in all three species (194 ± 30 μm and 134 ± 13 μm, 187 ± 22 μm and 127 ± 17 μm, 193 ± 37 μm and 144 ± 19 μm, respectively).
These sex-specific differences did not appear to be influenced by the type of sex determination system (the female/male total
SC length ratio was 1.45 in O. aureus, 1.47 in O. mossambicus and 1.34 in O. niloticus) and do not correlate with the lack of any overall sex-specific length differences in the current Oreochromis linkage map. Although based on data from relatively few species, there appears to be no consistent relationship between sex-specific
SC lengths and linkage map lengths in fish. Neomale (hormonally masculinized genetic female) O. aureus and O. mossambicus had total SC lengths of 138 ± 13 μm and 146 ± 13 μm respectively, more similar to normal males than to normal females. These
findings agree with data from other vertebrate species that suggest that phenotypic sex, rather than genotype, determines
traits such as total SC length, chiasmata position and recombination pattern, at least for the autosomes. 相似文献
12.
Ruixiang Zhao Junliang Sun Peter Torley Dahong Wang Shengyang Niu 《World journal of microbiology & biotechnology》2008,24(8):1349-1354
Lactobacillus acidophilus, as a probiotic, is widely used in many functional food products. Microencapsulation not only increases the survival rate
of L. acidophilus during storage and extends the shelf-life of its products, but also optimal size microcapsule makes L. acidophilus have an excellent dispersability in final products. In this paper, L. acidophilus was microencapsulated using spray drying (inlet air temperature of 170°C; outlet air temperature of 85–90°C). The wall materials
used in this study were β-cyclodextrin and acacia gum in the proportion of 9:1 (w/w), and microcapsules were prepared at four
levels of wall materials (15, 20, 25 and 30% [w/v]) with a core material concentration of 6% (v/v). The microcapsule diameters
were measured by Malvern’s Mastersizer-2000 particle size analyzer. The results showed that the particle diameters of microcapsule
were mostly within 6.607 μm and 60.256 μm and varied with 2.884–120.226 μm (the standard smaller microcapsule designated as
<350 μm). Through comparison of microcapsule size and uniformity with different concentration of wall materials, we concluded
that the optimal concentration of wall material was 20% (w/v), which gave microcapsule with a relatively uniform size (averaging
22.153 μm), and the number of surviving encapsulated L. acidophilus was 1.50 × 109 c.f.u./ml. After 8 weeks storage at 4°C, the live bacterial number was above 107 c.f.u./ml, compared with unencapsulated L. acidophilus, 104–105 c.f.u./ml. Through the observation of scanning electron microscopy, we found that the shapes of microcapsule were round and
oval, and L. acidophilus cells located in the centre of microcapsule. 相似文献
13.
Adriana Mara Gallego Ra Luisa Fernanda Rojas Aura Ines Urrea Trujillo Oriana Parra Zuleta Cristian David Correa Alvarez Luca Atehorta Garcs 《Bioprocess and biosystems engineering》2017,40(10):1479-1492
Cocoa butter (CB) is produced in the seeds of Theobroma cacao representing 50% of its dry weight. The lipid composition plays an important role in the physicochemical, rheological, and sensory properties of the CB, making this fat a valuable resource for the production of chocolates, cosmetics, and pharmaceuticals. In this paper, are described experimental strategies used for a rational improvement of biomass production and fatty acids in cacao cell suspension cultures. First, the lipid profile in four cacao varieties is characterized, and then, one variety is selected to induce cell suspensions using a direct method without previous establishment of a callus phase. To improve growth and total fat production in cell suspension cultures, modified DKW media and newly designed media culture, based on the mineral concentrations of cacao seeds (cacao biomass production, “CBP”), are analyzed and compared. In addition, the effect of acetate in the lipid profile of cell suspensions is evaluated. Ultrastructural histological analysis of lipid vesicles in cacao seeds and cell suspensions is also performed. The results will show that it is feasible to establish cacao suspensions without the calli step and increase the biomass production by selecting a suitable cacao variety and tissue and also applying a new culture media formulation. In addition, it is possible to synthesize fatty acids in cell cultures and modify the lipid profile adding a precursor of the novo biosynthesis of fatty acids such as the acetate. Transmission electronic microscopy examinations and differential interference contrast microscopy analysis will demonstrate that lipid vesicles are the main reserve substance in both cacao seeds and cell suspensions. 相似文献
14.
A cytoskeletal basis for wood formation in angiosperm trees: the involvement of cortical microtubules 总被引:3,自引:0,他引:3
Rearrangements of cortical microtubules (CMTs) during the differentiation of axial secondary xylem elements within taproots
and shoots of Aesculus hippocastanum L. (horse-chestnut) are described. A correlative approach was employed using indirect immunofluorescence microscopy of α-tubulin
in 6- to 10-μm sections and transmission electron microscopy of ultrathin sections. All cell types – fibres, vessel elements
and axial parenchyma – derive from fusiform cambial cells which contain randomly oriented CMTs. At the early stages of development,
fibres and axial parenchyma cells possess helically arranged CMTs, which increase in number as secondary wall thickening proceeds
and simple pits develop. In contrast, incipient vessel elements are distinguished by the marking out of sites of bordered
pits; these sites first appear as microtubule-free regions within the reticulum of randomly oriented CMTs that characterises
their precursor fusiform cambial cells. Subsequently, the ring of CMTs which develops at the periphery of the microtubule-free
region decreases in diameter as the over-arching pit border is formed. Like bordered pits, large-diameter, non-bordered pits
(contact pits) which develop between vessel elements and adjacent contact ray cells originate as microtubule-free regions
and are also associated with development of a ring of CMTs at the periphery. In the case of contact pits, however, there is
no reduction in the diameter of the CMT ring during pit development. Tertiary cell wall thickenings are also a feature of
vessel elements and appear to form at sites where bands of laterally associated, transversely oriented CMTs, separated from
each other by microtubule-free zones, are found. Later, these bands of CMTs become narrower, and separate into pairs of microtubule
bundles located on each side of the developing wall thickening. Development of perforations between vessel elements is also
associated with the presence of a ring of CMTs at their periphery.
Received: 13 July 1998 / Accepted: 30 November 1998 相似文献
15.
The effect of thidiazuron (TDZ) was studied on in vitro axillary shoot proliferation from nodal explant of Psoralea corylifolia - an endangered medicinal plant. Proliferation of shoots was achieved on Murashige and Skoog (MS) medium supplemented with
0.5, 1, 2, 3, 4 and 5 μM TDZ. The maximum number (13.6 ± 1.4) of shoots per explant were obtained from nodal segment cultured
on 2 μM TDZ for 4 weeks and this increased to 29.7 ± 2.1 on hormone free MS medium after 8 weeks. The in vitro proliferated and elongated shoots were transferred individually on a root induction medium containing 0.5 μM indole-3-butyric
acid (IBA) and within 4 weeks 4.5 ± 0.5 roots per shoot were produced. The regenerated plantlets were transferred to 1:1 soil
and vermiculite mixture and acclimatized with 80 % survival rate. Fully acclimatized plants were grown in garden soil in greenhouse
and their morphological and physiological parameters were comparable with seedlings. 相似文献
16.
Summary Changes in the spatial relationship between actin filaments and microtubules during the differentiation of tracheary elements (TEs) was investigated by a double staining technique in isolatedZinnia mesophyll cells. Before thickening of the secondary wall began to occur, the actin filaments and microtubules were oriented parallel to the long axis of the cell. Reticulate bundles of microtubules and aggregates of actin filaments emerged beneath the plasma membrane almost simultaneously, immediately before the start of the deposition of the secondary wall. The aggregates of actin filaments were observed exclusively between the microtubule bundles. Subsequently, the aggregates of actin filaments extended preferentially in the direction transverse to the long axis of the cell, and the arrays of bundles of microtubules which were still present between the aggregates of actin filaments became transversely aligned. The deposition of the secondary walls then took place along the transversely aligned bundles of microtubules.Disruption of actin filaments by cytochalasin B produced TEs with longitudinal bands of secondary wall, along which bundles of microtubules were seen, while TEs produced in the absence of cytochalasin B had transverse bands of secondary wall. These results indicate that actin filaments play an important role in the change in the orientation of arrays of microtubules from longitudinal to transverse. Disruption of microtubules by colchicine resulted in dispersal of the regularly arranged aggregates of actin filaments, but did not inhibit the formation of the aggregates itself, suggesting that microtubules are involved in maintaining the arrangement of actin filaments but are not involved in inducing the formation of the regularly arranged aggregates of actin filaments.These findings demonstrate that actin filaments cooperate with microtubules in controlling the site of deposition of the secondary wall in developing TEs.Abbreviations DMSO
dimethylsulfoxide
- EGTA
ethyleneglycolbis(-aminoethyl ether)-N,N,N,N-tetraacetic acid
- FITC
fluorescein isothiocyanate
- MSB
microtubule-stabilizing buffer
- PBS
phosphate buffered saline
- PIPES
piperazine-N,N-bis(2-ethanesulfonic acid)
- TE
tracheary element 相似文献
17.
Giovanni Iapichino Marcello Airò 《In vitro cellular & developmental biology. Plant》2008,44(4):330-337
Multiple shoots were induced on stem segments of an 8-y-old plant of Metrosideros excelsa Sol ex Gaertn. “Parnel”. Axillary shoots produced on uncontaminated explants were excised, segmented, and recultured in the
same medium to increase the stock of shoot cultures. The Murashige and Skoog (MS) medium, augmented with different concentrations
of 2- isopenthenyladenine (2iP) and indole-3-acetic acid (IAA), either singly or in combinations, as potential medium for
shoot multiplication by nodal segments was tested. In the following experiment, equal molar concentrations of four cytokinins
[2iP, kinetin, zeatin, and N
6-benzyladenine (BA)] in combination with equal molar concentrations of three auxins [IAA, α-naphthaleneacetic acid (NAA),
and indole-3-butyric acid (IBA)] were tested for ability to induce axillary shoot development from single-node stem segments.
The highest rate of axillary shoot proliferation was induced on MS agar medium supplemented with 1.96μM 2iP and 1.14μM IAA
after 6 wk in culture. Different auxins (IAA, IBA, and NAA) were tested to determine the optimum conditions for in vitro rooting of microshoots. The best results were accomplished with IAA at 5.71μM (89% rooting) and with IBA at 2.85 or 5.71μM
(86% and 86% rooting, respectively). Seventy and 90 percent of the microshoots were rooted ex vitro in bottom-heated bench (22 ± 2°C) after 2 and 4 wk, respectively. In vitro and ex vitro rooted plantlets were successfully established in soil. 相似文献
18.
In order to develop a novel transdermal drug delivery system that facilitates the skin permeation of finasteride encapsulated
in novel lipid-based vesicular carriers (ethosomes)finasteride ethosomes were constructed and the morphological characteristics
were studied by transmission electron microscopy. The particle size, zeta potential and the entrapment capacity of ethosome
were also determined. In contrast to liposomes ethosomes were of more condensed vesicular structure and they were found to
be oppositely charged. Ethosomes were found to be more efficient delivery carriers with high encapsulation capacities. In vitro percutaneous permeation experiments demonstrated that the permeation of finasteride through human cadaver skin was significantly
increased when ethosomes were used. The finasteride transdermal fluxes from ethosomes containing formulation (1.34 ± 0.11 μg/cm2/h) were 7.4, 3.2 and 2.6 times higher than that of finasteride from aqueous solution, conventional liposomes and hydroethanolic
solution respectively (P < 0.01).Furthermore, ethosomes produced a significant (P < 0.01) finasteride accumulation in the skin, especially in deeper layers, for instance in dermis it reached to 18.2 ± 1.8 μg/cm2. In contrast, the accumulation of finasteride in the dermis was only 2.8 ± 1.3 μg/cm2 with liposome formulation. The study demonstrated that ethosomes are promising vesicular carriers for enhancing percutaneous
absorption of finasteride. 相似文献
19.
Investigation of the life history of corals is hampered by an inability to identify early recruits. In this study, the pattern
of formation and morphology of the juvenile skeletons of three laboratory-reared pocilloporids, Seriatopora hystrix, Stylophora pistillata and Pocillopora damicornis, were compared to determine whether they could be reliably distinguished. The pattern of skeleton formation, including the
origin and structure of the septa, columella and corallite wall was similar in all species. Following the completion of the
primary corallite wall after 4–5 days, these species could be identified by differences in the diameter of the primary corallite.
The mean diameter (±SE) of each species differed markedly: S. hystrix 400 ± 2.7 μm, range 325–450 μm; S. pistillata 505 ± 3.5 μm, range 400–550 μm; P. damicornis 697 ± 7.5 μm, range 492–885 μm. Values for the primary corallite diameter overlapped in only 3% of samples, demonstrating
the potential utility of this feature as a tool for classifying recruits obtained from the field.
Accepted: 4 January 2000 相似文献
20.
T. Hogetsu 《Protoplasma》1990,156(1-2):67-73
Summary Binding of fluorescein-conjugated wheat-germ agglutinin (F-WGA) and some other lectins to tissues from various plants were examined by epifluorescence microscopy. F-WGA bound specifically to the walls of tracheary elements (TEs) and phloem cells of pea roots. The binding sites in TEs were localized only in the secondary thickening and became evident at very early stages of differentiation. Fluorescein-conjugated derivatives ofSolanum tuberosum lectin,Lycopersicon esculentum lectin, andDatura stramonium lectin, which bind N-acetylglucosamine residues as WGA, also bound to the secondary thickening of TEs of pea roots. The binding sites for F-WGA were not removed by extraction with hot EDTA and proteinase K, but removed by extraction with an alkali solution. The alkali-extracted binding sites from the roots were precipitated together with hemicelluloses by 80% ethanol. These results indicate that the binding sites are not present on pectins, proteins, or cellulose, but hemicelluloses. Localized distribution of the binding sites for F-WGA in TEs was found also in a variety of angiosperm plants.Abbreviations BSL-II
Bandeiraea simplicifolia lectin II
- DSL
Datura stramonium lectin
- F
fluorescein-conjugated
- LEL
Lycopersicon esculentum lectin
- MT
microtubule
- STL
Solanum tuberosum lectin
- TE
tracheary element
- WGA
wheat-germ agglutinin 相似文献