An electron microscopic study of the Golgi apparatus of amphibian oocytes

Conclusion An electron microscope study of the Golgi complex was carried out using amphibian oocytes both prior to and after vitellogenesis. In the former case it was noted that the Golgi complex consists of small vesicles and cisternae. After yolk formation, each Golgi mass was found to consist only of (a smaller number of) cisternae. The distribution, function, and multiplication of the Golgi material were also discussed.This work was supported by U.S.P.H.S. research grant RG 5803 (C 2) and was carried out during the course of a U.S.P.H.S. Special Research Fellowship (GF—5356—C 2).     

CONGESTIVE HEART FAILURE IN INFANTS AND CHILDREN

Congestive failure in infants and children is not uncommon and may be present in a varying number of conditions, particularly in certain types of congenital heart disease. Its recognition and proper treatment are usually followed by improvement, except in those instances where the failure is associated with a lesion incompatible with life. The essentials of treatment are: Treatment of the underlying cause, administration of a digitalis preparation, low salt diet, diuretics, rest and sedation, oxygen, adequate diet and, in rare instances, the use of steroids.     

An Inexpensive Inverted Microscope System

An inexpensive and easily constructable inverted microscope system is described in detail. Its multiple experimental usefulness in many branches of biology is mentioned.     

Effects of linoleic acid on capping,lectin mediated mitogenesis,surface antigen expression,and fluorescent polarization in lymphocytes and BHK cells

The incubation of linoleic acid with cells causes profound effects on membrane associated phenomenon. Using the fluorescent probe diphenyl hexatriene (DPH) to monitor lipid changes in the microenvironment of the cell surface, we find that linoleic acid reduces the polarization values (P) in mouse lymphocytes and BHK cells. Measurements on lipids extracted from the cells grown in linoleic acid produce similar results. We also find in the mouse lymphocyte that capping of Ig is inhibited and con A stimulated mitogenesis is unaffected. In contrast to the latter effect, LPS and PHA stimulated mitogenesis is inhibited and in the rat lymph node, con A stimulated mitogenesis, greatly enhanced. We also show that linoleic acid alters the binding of antibodies to the cell surface of EL-4 lymphoma cells. These observations suggest that linoleic acid alters cellular function by interfering with protein/lipid interactions within the surface membrane.     

Commentary Salicylate Trapping of -OH as a Tool for Studying Post-Ischemic Oxidative Injury in the Isolated Rat Heart

The use of salicylate as a chemical trap for -OH represents a simple and convenient alternative to the use of spin trapping techniques to study oxidative injury in isolated perfused organs. In these systems, salicylate is included in the perfusion buffer at concentrations ranging from 0.1 to 2mM depending on the detection apparatus employed. In our studies, we have used a coulometric detector, which has a theoretical efficiency of 100% as compared to 1-5% for the standard glassy carbon electrode. We have been able to generate reproducible results by inclusion of only 100 μM salicylate, a concentration demonstrated not to affect pre- or post-ischemic cardiac function. In initial studies, we observed an increase in perfusate 2,5-dihydroxybenzoic acid consistent with an early post-ischemic burst of -OH, not unlike that reported using spin trapping techniques. Since then we and others have used this technique to examine possible relationships between -OH formation and treatments that alter post-ischemic cardiac functional recovery. For example, preischemic loading of hearts with copper results in increases in postischemic dysfunction and LDH release that were associated with an increase in 2,5-dihydroxybenzoate and by inference, -OH formation. Alternatively, we have reported that the nitroxide spin label, TEMPO, reputed to be a superoxide dismutase mimetic, decreased post-ischemic arrhythmias and 2,5-dihydroxybenzoate formation. Most recently, we have observed that preischemic loading of hearts with zinc-bis-histidinate results in improved post-ischemic cardiac function and decreased LDH release; changes that were associated with decreased 2,5-dihydroxybenzoate formation. These studies indicate that under certain conditions, salicylate is a valuable alternative to spin trapping techniques to probe the role of -OH in cardiac oxidative injury, particularly when applied to the isolated perfused heart preparation.