scholarly journals Cerium chloride heptahydrate (CeCl3·7H2O) induces muscle paralysis in the generalist herbivore, Melanoplus sanguinipes (Fabricius) (Orthoptera: Acrididae), fed contaminated plant tissues

Chemosphere ◽  
2015 ◽  
Vol 120 ◽  
pp. 674-679 ◽  
Author(s):  
Jane E. Allison ◽  
Céline Boutin ◽  
David Carpenter ◽  
Deanna M. Ellis ◽  
Jessica L. Parsons
Author(s):  
John S. Gardner ◽  
W. M. Hess

Powdery mildews are characterized by the appearance of spots or patches of a white to grayish, powdery, mildewy growth on plant tissues, entire leaves or other organs. Ervsiphe cichoracearum, the powdery mildew of cucurbits is among the most serious parasites, and the most common. The conidia are formed similar to the process described for Ervsiphe graminis by Cole and Samson. Theconidial chains mature basipetally from a short, conidiophore mother-cell at the base of the fertile hypha which arises holoblastically from the conidiophore. During early development it probably elongates by polar-tip growth like a vegetative hypha. A septum forms just above the conidiophore apex. Additional septa develop in acropetal succession. However, the conidia of E. cichoracearum are more doliform than condia from E. graminis. The purpose of these investigations was to use scanning electron microscopy (SEM) to demonstrate the nature of hyphal growth and conidial formation of E. cichoracearum on field-grown squash leaves.


Author(s):  
Y. R. Chen ◽  
Y. F. Huang ◽  
W. S. Chen

Acid phosphatases are widely distributed in different tisssues of various plants. Studies on subcellular localization of acid phosphatases show they might be present in cell wall, plasma lemma, mitochondria, plastid, vacuole and nucleus. However, their localization in rice cell varies with developmental stages of cells and plant tissues. In present study, acid phosphatases occurring in root cap are examined.Sliced root tips of ten-day-old rice(Oryza sativa) seedlings were fixed in 0.1M cacodylate buffer containing 2.5% glutaraldehyde for 2h, washed overnight in same buffer solution, incubated in Gomori's solution at 37° C for 90min, post-fixed in OsO4, dehydrated in ethanol series and finally embeded in Spurr's resin. Sections were doubly stained with uranyl acetate and lead citrate, and observed under Hitachi H-600 at 75 KV.


Author(s):  
R.E. Crang ◽  
M. Mueller ◽  
K. Zierold

Obtaining frozen-hydrated sections of plant tissues for electron microscopy and microanalysis has been considered difficult, if not impossible, due primarily to the considerable depth of effective freezing in the tissues which would be required. The greatest depth of vitreous freezing is generally considered to be only 15-20 μm in animal specimens. Plant cells are often much larger in diameter and, if several cells are required to be intact, ice crystal damage can be expected to be so severe as to prevent successful cryoultramicrotomy. The very nature of cell walls, intercellular air spaces, irregular topography, and large vacuoles often make it impractical to use immersion, metal-mirror, or jet freezing techniques for botanical material.However, it has been proposed that high-pressure freezing (HPF) may offer an alternative to the more conventional freezing techniques, inasmuch as non-cryoprotected specimens may be frozen in a vitreous, or near-vitreous state, to a radial depth of at least 0.5 mm.


Author(s):  
P. F. Flicker ◽  
V.S. Kulkarni ◽  
J. P. Robinson ◽  
G. Stubbs ◽  
B. R. DasGupta

Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum. The toxin inhibits release of neurotransmitter, causing muscle paralysis. There are several serotypes, A to G, all of molecular weight about 150,000. The protein exists as a single chain or or as two chains, with two disulfide linkages. In a recent investigation on intracellular action of neurotoxins it was reported that type B neurotoxin can inhibit the release of Ca++-activated [3H] norepinephrine only if the disulfide bonds are reduced. In order to investigate possible structural changes in the toxin upon reduction of the disulfide bonds, we have prepared two-dimensional crystals of reduced type B neurotoxin. These two-dimensional crystals will be compared with those of the native (unreduced) type B toxin.


Author(s):  
Janet H. Woodward ◽  
D. E. Akin

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.


Author(s):  
Caroline A. Miller ◽  
David H. Nichols ◽  
Richard F. Murphy

Gastrin is a small peptide capable of both stimulating gastric acid secretion and acting as an enteric growth factor. Known functions of eosinophils in the rat stomach are related to immunological defense. Here we demonstrate the binding of biotinylated gastrin to rat stomach eosinophils in the electron microscope. Small pieces of stomach were fixed by immersion in 4% paraformaldehyde/0.1% glutaraldehyde in 0.1 M phosphate buffer, pH 7.4 for 1 hour. The tissue was then cryoprotected in 30% sucrose/0.1 M phosphate buffer, transferred to Tissue Tek OCT compound and frozen in isopentane cooled with liquid nitrogen. Transverse cryostat sections were cut at 25 μm, thawed in PBS and free floating sections exposed to 10−5 M biotinylated 1-17 gastrin (human sequence; Peninsula Labs) for 1 hour. Controls omitted the biotinylated gastrin from this step. Sections were then rinsed 3X in PBS and exposed to either:1).a 1:50 dilution of 10 nm Extravidin colloidal gold (Sigma) for 2 hours, or2).an avidin-biotin-alkaline phosphatase complex (ABC-AP;Vector) for 1 hour. A substrate solution containing cerium chloride was used to generate an electron dense reaction product.Sections from both procedures were postfixed in 1% OsO4 in 0.1 M phosphate buffer, rinsed and dehydrated. These were then flat embedded in EMbed 812 between two microscope slides coated with Liquid Release (both from Electron Microscopy Sciences).Polymerized sections were adhered to resin blocks using super glue, cut at 70-90 nm, stained with uranyl acetate/lead citrate and observed in a Philips CM-10 electron microscope.


The first case of tick-borne encephalitis (TBE) in Lithuania, diagnosed by clinical and epidemiologic criteria only, was reported in 1953. A forest worker became ill with the disease in April after a tick bite, had a typical clinical presentation with shoulder girdle muscle paralysis and bulbar syndrome, and died after 12 days from the start of clinical symptoms. Autopsy data were compatible with viral encephalitis.1 Serological diagnosis of TBE in Lithuania was started in 1970.2


2018 ◽  
Vol 44 (2) ◽  
pp. 159-168
Author(s):  
H. Yang ◽  
H.Y. Zhu ◽  
Y.G. Gao ◽  
Y.H. Xu ◽  
L.X. Zhang ◽  
...  
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