Impact of temperature variations on toxic effects of the polypeptides secreted by Phaeoacremonium aleophilum

Observations of the spatial structure of interstellar hydrogen

Symposium - International Astronomical Union ◽

10.1017/s007418090010066x ◽

1967 ◽

Vol 31 ◽

pp. 45-46

Author(s):

Carl Heiles

Keyword(s):

High Resolution ◽

Spatial Structure ◽

Velocity Dispersion ◽

Temperature Variations

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.

Download Full-text

Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100061847 ◽

1967 ◽

Vol 25 ◽

pp. 366-367

Author(s):

D. M. Davies ◽

R. Kemner ◽

E. F. Fullam

Keyword(s):

Thin Film ◽

Electron Microscope ◽

High Altitude ◽

Amyl Acetate ◽

Temperature Variations ◽

Film Forming ◽

Film Specimen ◽

Particulate Contaminants

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.

Download Full-text

Ultrastructure of the effect of T-514 obtained from Karwinskia humboldtiana on assembly and integrity of yeast's peroxisomes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084983 ◽

1991 ◽

Vol 49 ◽

pp. 136-137

Author(s):

J. Sepulveda-Saavedra ◽

I. Vander-Klei ◽

M. Venhuis ◽

Y. Piñeyro-Lopez

Keyword(s):

Culture Conditions ◽

Toxic Effects ◽

Candida Boidinii ◽

Central Mexico ◽

Poisonous Plant ◽

Biological Behaviour ◽

Enzyme Content ◽

Fat Deposits ◽

Yeast Model

Karwinskia humboldtiana is a poisonous plant that grows in semi desertic areas in north and central México. It produces several substances with different toxic effects. One of them designated T-514 damages severely the lung, kidney and liver, producing in the hepatoeyte large intracellular fat deposits and necrosis. Preliminary observations demonstrated that three is a decrease in the amount of peroxisomes in the hepatocytes of experimentally intoxicated rats and monkeys. To study the effect exerted by the T-514 on peroxisomes, a yeast model was selected, thus, three species: Saccha romices cerevisiae, Ilansenula polymorpha and Candida boidinii were used, because there is information concerning their peroxisome's morphology, enzyme content, biological behaviour under different culture conditions and biogenesis.

Download Full-text

Some Conditions Necessary for Pinocytosis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100457 ◽

1968 ◽

Vol 26 ◽

pp. 142-143

Author(s):

M. W. Brightman

Keyword(s):

Smooth Muscle ◽

Cell Membrane ◽

Toxic Effects ◽

Cytological Evidence ◽

Cell Processes

The cytological evidence for pinocytosis is the focal infolding of the cell membrane to form surface pits that eventually pinch off and move into the cytoplasm. This activity, which can be inhibited by oxidative and glycolytic poisons, is performed only by cell processes that are at least 300A wide. However, the interpretation of such toxic effects becomes equivocal if the membrane invaginations do not normally lead to the formation of migratory vesicles, as in some endothelia and in smooth muscle. The present study is an attempt to set forth some conditions under which pinocytosis, as distinct from the mere inclusion of material in surface invaginations, can take place.

Download Full-text