Fungal exudates

1978 ◽  
Vol 24 (10) ◽  
pp. 1173-1181 ◽  
Author(s):  
Nicholas Colotelo
Keyword(s):  
Osmium Tetroxide ◽  
Sclerotium Rolfsii ◽  
Claviceps Purpurea ◽  
Liquid Droplets ◽  
Colloidal Solutions ◽  
Membranous Structure ◽  
Freeze Dried ◽  
Myrothecium Roridum ◽  
Biochemical Analyses ◽  
Membranous Material

The exudates or liquid droplets on various structures of a number of fungi were examined. The droplets were enveloped in membranous material and were associated with actively growing mycelia, including fruiting structures. Osmium tetroxide vapour-fixed droplets of Claviceps purpurea, Myrothecium roridum, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Thanathephorus cucumeris did not dry to a powder but remained intact as spheres when freeze-dried. Fractured spheres, examined with the scanning electron microscope, showed the presence of a membranous structure similar to that of rapidly frozen colloidal solutions with the ice crystals removed by sublimation. Locules or cavities within the freeze-dried droplets are thought to be due to the entrapment of air when droplets coalesce. Biochemical analyses of the exudates showed that acid phosphatase, β-glucosidase, acid and alkaline protease, RNase polygalacturonase and cellulase enzymes as well as oxalic acid and ammonia were present.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Ultrastructure of Liver in Lactosyl Ceramidosis

1971 ◽  
Vol 29 ◽  
pp. 312-313
Author(s):  
Z. Hruban ◽  
J. R. Esterly ◽  
G. Dawson ◽  
A. O. Stein
Keyword(s):  
Connective Tissue ◽  
Liver Biopsy ◽  
Osmium Tetroxide ◽  
Close Contact ◽  
Multivesicular Bodies ◽  
Bile Canaliculi ◽  
Dense Bodies ◽  
Marginal Plates ◽  
Membranous Material ◽  
Perichromatin Granules

Samples of a surgical liver biopsy from a patient with lactosyl ceramidosis were fixed in paraformaldehyde and postfixed in osmium tetroxide. Hepatocytes (Figs. 1, 2) contained 0.4 to 2.1 μ inclusions (LCI) limited by a single membrane containing lucid matrix and short segments of curved, lamellated and circular membranous material (Fig. 3). Numerous LCI in large connective tissue cells were up to 11 μ in diameter (Fig. 2). Heterogeneous dense bodies (“lysosomes”) were few and irregularly distributed. Rough cisternae were dilated and contained smooth vesicles and surface invaginations. Close contact with mitochondria was rare. Stacks were small and rare. Vesicular rough reticulum and glycogen rosettes were abundant. Smooth vesicular reticulum was moderately abundant. Mitochondria were round with few cristae and rare matrical granules. Golgi complex was seen rarely (Fig. 1). Microbodies with marginal plates were usual. Multivesicular bodies were very rare. Neutral lipid was rare. Nucleoli were small and perichromatin granules were large. Small bile canaliculi had few microvilli (Fig. 1).

scholarly journals Vapor fixation for immunocytochemistry and X-ray microanalysis on cryoultramicrotome sections.

1984 ◽  
Vol 32 (6) ◽  
pp. 636-642 ◽  
Author(s):  
P M Frederik ◽  
P H Bomans ◽  
W M Busing ◽  
R Odselius ◽  
W M Hax
Keyword(s):  
Exocrine Pancreas ◽  
Osmium Tetroxide ◽  
Protein A ◽  
Alpha Amylase ◽  
X Ray ◽  
Freeze Dried ◽  
Frozen Tissue ◽  
Formaldehyde Vapor ◽  
Fresh Frozen ◽  
Subcellular Level

Several organic and inorganic vapor fixatives have been tested for their ability to stabilize the ultrastructure of freeze-dried thin cryosections. The vapors from osmium tetroxide and dry formaldehyde gave a good preservation of the ultrastructure. Fixation in formaldehyde vapor preserved the immunoreactivity of alpha-amylase in exocrine pancreas, as was demonstrated with an indirect labeling technique using anti-alpha-amylase and protein A-gold. A major advantage of the use of vapor fixation is that cryosections from a specimen of fresh-frozen tissue can be used for immunocytochemistry as well as for X-ray microanalysis, as was demonstrated for the exocrine pancreas. This opens the possibility of localizing atomic species (X-ray microanalysis) and molecular species (immunocytochemistry) at the subcellular level on thin cryosections from the same tissue block.

scholarly journals Applications of Focused Ion Beam (FIB) on Yeast Cell & SARS Virus

2007 ◽  
Vol 15 (5) ◽  
pp. 42-43
Author(s):  
H. L. Hing ◽  
C. Burkhardt ◽  
P. Gnauck ◽  
S. Sally ◽  
H. Gelderbloms ◽  
...  
Keyword(s):  
Osmium Tetroxide ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Energy ◽  
Alcohol Concentration ◽  
Yeast Cells ◽  
Virus Particles ◽  
Freeze Dried ◽  
Wide Range ◽  
Material Sciences

The focused ion beam (FIB) is a relatively novel technique to biomedical electron microscopy as it open up new means for the observations and examinations of a wide range of biomedical and biological materials. The focused ion beam, or FIB tool has been utilized mainly in the fields of material sciences and industry. The (FIB) uses high-energy gallium ions to precisely and accurately section or mill samples. Lately FIB method have been used to prepare biological samples such as yeast cells and virus particles. Yeast cells Schwanniomyces occidentalis S. occidentalis were prepared by vacuum sucking them into cellulose tubing, plunge freezing them in liquid nitrogen, followed by chemical fixation in glutaraldehye and postfixed with osmium tetroxide, dehydrated in a series of ascending alcohol concentration up to absolute alcohol, then freeze dried overnight. In the case of SARS virus, the tissue culture containing virus particles was chemically fixed with glutaraldehyde, dehydrated in ascending order of alcohol concentrations and then freeze dried.

An energy dispersive x-ray analysis study of elemental loss from globoid crystals in protein bodies as a result of osmium tetroxide fixation

1978 ◽  
Vol 56 (19) ◽  
pp. 2408-2414 ◽  
Author(s):  
J. N. A. Lott ◽  
J. S. Greenwood ◽  
C. M. Vollmer
Keyword(s):  
Osmium Tetroxide ◽  
Juglans Regia ◽  
Energy Dispersive ◽  
Protein Bodies ◽  
X Ray ◽  
Edx Analysis ◽  
Freeze Dried ◽  
Major Loss ◽  
Degree Of Extraction ◽  
Helichrysum Bracteatum

This study was undertaken to discover what elemental losses, if any, were occurring from globoid crystals in seed protein bodies during glutaraldehyde – osmium tetroxide fixation. Unfixed cotyledon and radicle tissue of Cucurbita maxima seed, or tissue after glutaral–dehyde–OsO4 treatment, was quick frozen in liquid N2, ground with a cold mortar and pestle, and low-temperature freeze-dried. Globoid crystals in the freeze-dried powder were subjected to energy dispersive x-ray (EDX) analysis. OsO4 fixation resulted in a major loss of P, Mg, and K from cotyledon globoid crystals and a major loss of P, Mg, K, and Ca from radicle globoid crystals. Despite the loss of elements, the OsO4-fixed globoid crystals were still electron dense. When globoid crystals from glutaraldehyde-fixed, dehydrated, and embedded cotyledon tissue were compared with globoid crystals from glutaraldehyde–OsO4-fixed, dehydrated, and embedded tissue, some extraction was found. The degree of extraction varied from complete loss of P, K, and Mg to loss of K only.Effects of glutaraldehyde–OsO4 fixation upon elemental composition of globoid crystals in several other species was also determined. Brazil nut (Bertholletia excelsa) radicle tissue or cotyledon tissue from walnut (Juglans regia), hazelnut (Corylus avellana), sunflower (Helianthus annuus), golden everlasting daisy (Helichrysum bracteatum), cashew (Anacardium occidentale), pistachio (Pistacia vera), and the Western Australian red-capped gum (Eucalyptus erythrocorys) were fixed either in glutaraldehyde or in glutaraldehyde–OsO4. In these species, EDX analysis of globoid crystal sections showed that OsO4 fixation results in major loss of Mg, K, and Ca. Generally, phosphorus levels were reduced from control values as well. When carrying out EDX analysis studies of globoid crystals, we recommend (1) avoiding any use of OsO4, (2) keeping all fixation, washing, and dehydration times as short as possible, and (3) checking all observations with freeze-dried powders.

Effect of osmium vapor on calcium loss during sectioning of freeze-dried, embedded tissue

1986 ◽  
Vol 44 ◽  
pp. 258-259
Author(s):  
L. J. McGuffee ◽  
S. A. Little
Keyword(s):  
Smooth Muscle ◽  
Freeze Drying ◽  
Osmium Tetroxide ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Freeze Dried ◽  
Quick Freezing ◽  
Calcium Loss ◽  
Cellular Organelles

Our laboratory has been using electron microscopic autoradiography to localize 45Ca in smooth muscle. We prepare the tissue for these studies by quick freezing against a copper mirror, freeze-drying at low temperature, exposing the dry tissue to osmium tetroxide vapors in vacuo, and infiltrating and embedding in Spurr resin.Two requirements must be met before one can examine the distribution of a soluble ion, such as calcium, using this, or any morphological technique. First, morphological perservation of the tissue must be sufficient to identify cellular organelles and membranes. This requirement can be met in smooth muscle by using freeze-dried Spurr embedded tissue. Second, the distribution of calcium must be representative of the in vivo distribution.

Fruit Quality Changes of Salak “Pondoh” Fruits (Salacca zalacca (Gaertn.) Voss) during Maturation and Ripening

2013 ◽  
Vol 2 (1) ◽  
pp. 204 ◽  
Author(s):  
Reni Lestari ◽  
Georg Ebert ◽  
Susanne Huyskens-Keil
Keyword(s):  
Fruit Size ◽  
Middle Lamella ◽  
Texture Measurement ◽  
Ripening Process ◽  
Physiological Processes ◽  
Acid Ratio ◽  
Freeze Dried ◽  
Stage 4 ◽  
Biochemical Analyses

Salak is a very important fruit product in Indonesia that has been cultivated throughout Indonesia and has been exported to several countries. The study to determine biochemical and physical as well as physiological changes during fruit maturation and ripening was applied to two superior salak cultivars, “pondoh hitam” and “pondoh super” originally from Sleman, Yogyakarta of Indonesia. Fresh salak fruits of the cultivars “pondoh hitam” and “pondoh super” at three different ripening stages were used, i.e. stage 4, stage 5 and stage 5.5 (4, 5 and 5.5 months after pollination, respectively) for “pondoh hitam” and stage 4, stage 5 and stage 6 (4, 5 and 6 months after pollination, respectively) for “pondoh super”.<strong> </strong>Immediately after air transport from Indonesia to Germany, determination of fruit colour and texture as well as biochemical analyses were carried out in Berlin. Freeze-dried sample material was used for the determination of minerals, mono- and disaccharides, pectic substances and dietary fibre. Results of the study showed that increase in fruit size and weight as well as changes in peel and pulp colour occurred during maturation and ripening of salak fruits. Different patterns of peel and pulp colour changes were found in “pondoh super” and “pondoh hitam” during ripening. Physiological processes in “pondoh super” occurred to at a later stage but then accelerated faster than “pondoh hitam” in term of changes of mono- and disaccharides, resulting in a poorer marketability and shorter shelf life. In respect to the changes of sugar/acid ratio, there was a faster ripening process in “pondoh super” than in “pondoh hitam”. “Pondoh super” possessed higher content of polysaccharides and lignin, however, the ripening process accelerated earlier in comparison to “pondoh hitam”. Alterations in cell wall and middle lamella structure did not correlated with the physical non destructive texture measurement during ripening of salak.

scholarly journals Encapsulation of Lactobacillus casei (ATCC 393) by Pickering-Stabilized Antibubbles as a New Method to Protect Bacteria against Low pH

2020 ◽  
Vol 4 (3) ◽  
pp. 40
Author(s):  
Vida Mardani Ghahfarokhi ◽  
Paolo P. Pescarmona ◽  
Gert-Jan W. Euverink ◽  
Albert T. Poortinga
Keyword(s):  
Aqueous Phase ◽  
Lactobacillus Casei ◽  
Silica Particles ◽  
Low Ph ◽  
New Method ◽  
Liquid Droplets ◽  
Freeze Dried ◽  
Oil In Water

Pickering-stabilized antibubbles were used as a new method to encapsulate Lactobacillus casei. Antibubbles consist of one or more liquid droplets within a shell of gas. The antibubbles were prepared from a water-in-oil-in-water (W/O/W) emulsion stabilized by silica particles, which was then freeze-dried to remove the water and oil phases, before being subsequently reconstituted in water. Different oil phases and aqueous phase compositions were tested for their effect on the survival of the bacteria. The survival of L. casei after encapsulation using decane was 29.8 ± 2.1% in antibubbles containing 10% (w/v) maltodextrin plus 8% (w/v) sucrose, which is comparable to the survival when bacteria were freeze-dried without being encapsulated. Encapsulation within antibubbles led to a 10 to 30 times higher survival of L. casei at pH 2 in comparison with unencapsulated bacteria. This study shows that probiotics can be encapsulated within a shell of gas through the use of antibubbles and that this protects probiotics against a low pH.

Electron spectroscopic imaging of chemical versus cryo-fixed myocardial cells

1991 ◽  
Vol 49 ◽  
pp. 288-289
Author(s):  
Robyn Rufner ◽  
Rebecca C. Stearns ◽  
Cindy L. Hastings ◽  
James D. Marsh ◽  
John J. Godleski
Keyword(s):  
Freeze Drying ◽  
Osmium Tetroxide ◽  
Spectroscopic Imaging ◽  
Chemical Fixation ◽  
Myocardial Cells ◽  
Electron Spectroscopic Imaging ◽  
Freeze Dried ◽  
Processing Regimes ◽  
Electron Energy Loss ◽  
Intracellular Ions

Since chemical fixation and dehydration of cells results in loss and/or redistribution of endogenous ions, cryofixation with a process that preserves ultrastructure and the localization of intracellular ions is critical. Myocytes and macrophages prepared by the LifeCell® process of slam-freezing and freeze drying with subsequent osmium tetroxide/paraformaldehyde fixation have exhibited excellent structural and compositional integrity when examined by Electron Spectroscopic Imaging (ESI) and by Electron Energy Loss Spectroscopy (EELS). However, it has not been established if the apparent enhanced structure, particularly of cristae and membranes within mitochrondria, is solely a result of lipid preservation or if fixation with osmium tetroxide vapors can explain the pronounced “thickness” of membranes. In this study the effects of freezeslammed, freeze-dried myocytes with two different processing regimes for postfixation were compared to myocytes prepared by conventional chemical fixation.

Cellular Contacts Within the Interhemal Membrane of the Rat Placenta at Term

1974 ◽  
Vol 32 ◽  
pp. 146-147
Author(s):  
William P. Jollie
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Capillary Endothelium ◽  
En Bloc ◽  
Aldehyde Fixation ◽  
Chorioallantoic Placenta

By routine EM preparative techniques, the tissues which, collectively, separate maternal and fetal bloods in the fully formed chorioallantoic placenta of the rat have been shown to consist of three chorionic layers, or trophoblast, and a layer of allantoic capillary endothelium [Fig. 1]. Relationships between these layers are best demonstrated by special techniques, viz., cacodylate-buffered aldehyde fixation, collidine-buffered osmium tetroxide postfixation, and en bloc staining with uranyl acetate. By using this method on placentas at term, the cells of the outermost chorionic layer (Trophoblast 1) appear to be attached to each other by means of maculae adherentes which sometimes occur in clusters [Fig. 2].

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