Cotton (Gossypium hirsutum) seed trichomes expand via diffuse growing mechanism

Suresh C. Tiwari; Thea A. Wilkins

doi:10.1139/b95-081

Cotton (Gossypium hirsutum) seed trichomes expand via diffuse growing mechanism

Canadian Journal of Botany ◽

10.1139/b95-081 ◽

1995 ◽

Vol 73 (5) ◽

pp. 746-757 ◽

Cited By ~ 87

Author(s):

Suresh C. Tiwari ◽

Thea A. Wilkins

Keyword(s):

Gossypium Hirsutum ◽

Cotton Seed ◽

Morphological Changes ◽

Plant Cells ◽

Freeze Substitution ◽

Diffuse Growth ◽

Cytological Features ◽

Freeze Fixation ◽

Insight Into

The ultrastructure of cotton (Gossypium hirsutum) seed trichomes was investigated to obtain insight into their growth behavior during the phase of rapid cell elongation. A mold and cast method of scanning electron microscopy was used to record the morphological changes in the ovular surface during the initiation and elongation of trichomes. A rapid freeze-fixation and freeze-substitution protocol was used to study the cytological features of trichomes at 2 days after anthesis. At the cytological level, attention was primarily focused on determining whether the seed trichomes display features that are characteristic of other tip-growing plant cells, including organelle zonation, polarized deposition of cell wall, axial orientation of microtubules, and microfilament meshwork at the cell apex. Our results show that cotton seed trichomes do not share any ultrastructural characteristic with other tip-growing plant cells. Rather, they show all the characteristics of cells that undergo diffuse growth. The roles of actin microfilaments and microtubules were also investigated through an in vitro administration of cytochalasin D and colchicine. Although the disruption of actin filaments did not stop trichome growth, disruption of microtubules did prevent polarized cell expansion. Based on these results, cotton seed trichomes are not tip-growing cells but expand via diffuse growth. Key words: cytoskeleton, freeze-fixation, freeze-substitution, Gossypium hirsutum, lint fibers, tip growth, trichomes.

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Probing secondary metabolism in plant cell cultures

Canadian Journal of Botany ◽

10.1139/b84-390 ◽

1984 ◽

Vol 62 (12) ◽

pp. 2912-2917 ◽

Cited By ~ 12

Author(s):

B. E. Ellis

Keyword(s):

Secondary Metabolism ◽

Cell Cultures ◽

Genome Organization ◽

Plant Cells ◽

Cell Manipulation ◽

Experimental Systems ◽

Metabolic Integration ◽

Cell To Cell Variability ◽

Insight Into

In vitro cultured plant cells which still express parts of their secondary metabolism phenotype are versatile experimental systems for studies of biosynthesis and metabolic integration, enzymology, and genome organization. Single cell manipulation can also provide insight into the question of cell-to-cell variability and metabolic competence.

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X-Ray Microanalysis of Human Erythrocytes Artificially Jetted Through Tubes At Different Pressures by “in vitro Cryotechnique”

Microscopy and Microanalysis ◽

10.1017/s1431927600029731 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 732-733

Author(s):

Y. Fujii ◽

N. Terada ◽

T. Baba ◽

H. Ueda ◽

S. Ohno

Keyword(s):

Human Erythrocyte ◽

Morphological Changes ◽

Freeze Substitution ◽

Substitution Method ◽

In Vivo Cryotechnique ◽

Blood Capillaries ◽

X Ray ◽

Freeze Dried

It is well known that flowing erythrocytes in blood capillaries were morphologically changing in vivo, as observed by light microscopy. Recently, dynamic morphological changes of flowing mouse erythrocytes in large blood vessels and hepatic sinusoids were demonstrated by scanning (SEM) or transmission (TEM) electron microscopy with our “in vivo cryotechnique”. Moreover, human erythrocyte deformability was already studied under artificially jetting conditions at different pressures by using “in vivo cryotechnique”, followed by freeze-substitution method for SEM. in this study, we have analyzed elemental changes of each human erythrocyte at different jetting pressures by “in vivo cryotechnique” combined with SEM for X-ray microanalysis.Human blood was collected with heparin-coated syringes, divided into two groups and kept at 4°C and 36°C. They were directly jetted into isopentane-propane cryogen (-193°C) through tubes (21 gauge) at different pressures (0-220mmHg) (Fig.la). The frozen blood samples were freeze-dried (4-6×10-7torr,-95°C,24h) in Eiko FD-3AS apparatus (Eiko Engineering, Japan) (Fig. lb).

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Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116620 ◽

1975 ◽

Vol 33 ◽

pp. 600-601

Author(s):

John C. Garancis ◽

Robert O. Hussa ◽

Michael T. Story ◽

Donald Yorde ◽

Roland A. Pattillo

Keyword(s):

Electron Microscopy ◽

Cellular Proliferation ◽

Morphological Changes ◽

Culture Fluid ◽

Cellular Functions ◽

Human Trophoblast ◽

Transmission Electron ◽

Marked Activity ◽

Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

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Immunocytochemistry after fast freeze fixation-freeze substitution: Advantages and limits

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157759 ◽

1990 ◽

Vol 48 (3) ◽

pp. 42-43

Author(s):

Marie-Thérèse Nicolas

Keyword(s):

Osmium Tetroxide ◽

Freeze Substitution ◽

Acrylic Resin ◽

Expected Improvement ◽

List Type ◽

Chemical Fixation ◽

Freeze Fixation ◽

Liquid Chemical ◽

Luciferase Enzyme ◽

Lower Background

An alternative to aqueous chemical fixation consists in immobilizing physically the specimen by freezing it as fast as possible without using any cryoprotectant. This Fast Freeze Fixation (FFF) followed by Freeze Substitution (FS) avoids osmotic artefacts due to the slow penetration of liquid chemical fixative. Associated with Immuno-Gold labeling (IGS), FFF-FS allows a more precise localization of antigens.Using the bioluminescent bacteria Vibrio harveyi, a comparison of IGS with an antibody directed against its luciferase (enzyme of the luminescent reaction) has been done after liquid chemical fixation versus FFFFS. This later technique, beside an expected improvement of the ultrastructure always shows a better preservation of antigenicity and a lower background. In the case of FFF-FS technique (Figure 3):–labeling in acrylic resin (LRWhite) is 2 to 4 fold more intense than in epoxy resin (Epon),–but the ultrastructure is always better in Epon.–but the ultrastructure is always better in Epon.–The addition of fixatives in the substitution medium, results in a decrease of labeling which is more important in the case of a mixture of fixatives than with osmium tetroxide alone; with one exception: the substitution with glutaraldehyde which produces a dramatic increase in the density of the labeling but also, at the same time, a swelling of the cells of about 30%.

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Effect of Temperature, Velocity Gradient and I.V. Heparin on in Vitro Blood Coagulation and Platelet Aggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654086 ◽

1967 ◽

Vol 17 (01/02) ◽

pp. 112-119 ◽

Cited By ~ 3

Author(s):

L Dintenfass ◽

M. C Rozenberg

Keyword(s):

Blood Coagulation ◽

Velocity Gradient ◽

Elevated Temperatures ◽

Morphological Changes ◽

Effect Of Temperature ◽

Clotting Time ◽

Progressive Change ◽

Aggregation Of Platelets ◽

Microscopic Techniques

SummaryA study of blood coagulation was carried out by observing changes in the blood viscosity of blood coagulating in the cone-in-cone viscometer. The clots were investigated by microscopic techniques.Immediately after blood is obtained by venepuncture, viscosity of blood remains constant for a certain “latent” period. The duration of this period depends not only on the intrinsic properties of the blood sample, but also on temperature and rate of shear used during blood storage. An increase of temperature decreases the clotting time ; also, an increase in the rate of shear decreases the clotting time.It is confirmed that morphological changes take place in blood coagula as a function of the velocity gradient at which such coagulation takes place. There is a progressive change from the red clot to white thrombus as the rates of shear increase. Aggregation of platelets increases as the rate of shear increases.This pattern is maintained with changes of temperature, although aggregation of platelets appears to be increased at elevated temperatures.Intravenously added heparin affects the clotting time and the aggregation of platelets in in vitro coagulation.

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Cytotoxic Effect of the Combination of Gemcitabine and Atorvastatin Loaded in Microemulsion on the HCT116 Colon Cancer Cells

International Journal of Pharmaceutical and Clinical Research ◽

10.25258/ijpcr.v9i2.8298 ◽

2017 ◽

Vol 9 (2) ◽

Cited By ~ 1

Author(s):

Mayson H. Alkhatib ◽

Dalal Al-Saedi ◽

Wadiah S. Backer

Keyword(s):

Colon Cancer ◽

Cancer Cells ◽

Anticancer Drugs ◽

Therapeutic Potential ◽

Morphological Changes ◽

In Vitro Study ◽

Colon Cancer Cells ◽

Apoptosis Detection ◽

Hct116 Cells

The combination of anticancer drugs in nanoparticles has great potential as a promising strategy to maximize efficacies by eradicating resistant, reduce the dosage of the drug and minimize toxicities on the normal cells. Gemcitabine (GEM), a nucleoside analogue, and atorvastatin (ATV), a cholesterol lowering agent, have shown anticancer effect with some limitations. The objective of this in vitro study was to evaluate the antitumor activity of the combination therapy of GEM and ATVencapsulated in a microemulsion (ME) formulation in the HCT116 colon cancer cells. The cytotoxicity and efficacy of the formulation were assessed by the 3- (4,5dimethylthiazole-2-yl)-2,5-diphyneltetrazolium bromide (MTT) assay. The mechanism of cell death was examined by observing the morphological changes of treated cells under light microscope, identifying apoptosis by using the ApopNexin apoptosis detection kit, and viewing the morphological changes in the chromatin structure stained with 4′,6-diamidino-2-phenylindole (DAPI) under the inverted fluorescence microscope. It has been found that reducing the concentration of GEM loaded on ME (GEM-ME) from 5μM to 1.67μM by combining it with 3.33μM of ATV in a ME formulation (GEM/2ATV-ME) has preserved the strong cytotoxicity of GEM-ME against HCT116 cells. The current study proved that formulating GEM with ATV in ME has improved the therapeutic potential of GEM and ATV as anticancer drugs.

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Morphological Changes and Iron Uptake in Human Normoblasts in Vitro: I. Proliferation and Destruction of Nucelated Red Cells During Incubation of Normal Bone Marrow

Scandinavian Journal of Clinical and Laboratory Investigation ◽

10.3109/00365516409060509 ◽

1964 ◽

Vol 16 (2) ◽

pp. 222-232 ◽

Cited By ~ 3

Author(s):

Erik Myhre

Keyword(s):

Bone Marrow ◽

Iron Uptake ◽

Morphological Changes ◽

Red Cells ◽

Normal Bone Marrow ◽

Normal Bone

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The Anti-tumor Activity and Mechanisms of rLj-RGD3 on Human Laryngeal Squamous Carcinoma Hep2 Cells

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520619666191022160024 ◽

2020 ◽

Vol 19 (17) ◽

pp. 2108-2119

Author(s):

Yang Jin ◽

Li Lv ◽

Shu-Xiang Ning ◽

Ji-Hong Wang ◽

Rong Xiao

Keyword(s):

Wound Healing ◽

Western Blot ◽

Morphological Changes ◽

In Vivo Studies ◽

Migration And Invasion ◽

Tunel Staining ◽

Dna Ladder ◽

Western Blot Assay

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: hese results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.

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Ability of PknA, a mycobacterial eukaryotic-type serine/threonine kinase, to transphosphorylate MurD, a ligase involved in the process of peptidoglycan biosynthesis

Biochemical Journal ◽

10.1042/bj20080234 ◽

2008 ◽

Vol 415 (1) ◽

pp. 27-33 ◽

Cited By ~ 45

Author(s):

Meghna Thakur ◽

Pradip K. Chakraborti

Keyword(s):

Protein Kinases ◽

Solid Phase ◽

Morphological Changes ◽

Binding Assays ◽

Serine Threonine Kinase ◽

Threonine Kinase ◽

Peptidoglycan Biosynthesis ◽

Vitro Binding ◽

Solid Phase Binding

Eukaryotic-type serine/threonine protein kinases in bacteria have been implicated in controlling a host of cellular activities. PknA is one of eleven such protein kinases from Mycobacterium tuberculosis which regulates morphological changes associated with cell division. In the present study we provide the evidence for the ability of PknA to transphosphorylate mMurD (mycobacterial UDP-N-acetylmuramoyl-L-alanine:D-glutamate-ligase), the enzyme involved in peptidoglycan biosynthesis. Its co-expression in Escherichia coli along with PknA resulted in phosphorylation of mMurD. Consistent with these observations, results of the solid-phase binding assays revealed a high-affinity in vitro binding between the two proteins. Furthermore, overexpression of m-murD in Mycobacterium smegmatis yielded a phosphorylated protein. The results of the present study therefore point towards the possibility of mMurD being a substrate of PknA.

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