Earle's Balanced Salt Research Articles

Autoradiographic localization of newly synthesized inositol phospholipids in the superior cervical ganglion

Muscarine stimulates the hydrolysis of inositol-containing phospholipids and increases the activity of tyrosine hydroxylase in the ganglion. Vasopressin also stimulates the hydrolysis of inositol-containing phospholipids in the ganglion but does not increase the activity of tyrosine hydroxylase (tyrosine 3-monooxygenase) in this tissue. Most of the tyrosine hydroxylase in the ganglion is localized in the cell bodies of the principal ganglionic neurons. Establishing a role for phospholipid turnover in the mechanism by which muscarine increases tyrosine hydroxylase activity requires a demonstration that muscarine increases phospholipid metabolism in these cell bodies and that vasopressin increases phospholipid metabolism in some other compartment within the ganglion. The chapter explains the isolation and incubation of ganglia. To study the effects of agonists on inositol phospholipid synthesis, the ganglia are incubated in Earle's Balanced Salt Solution (EBSS)-containing [ 3 H]inositol, in the presence or absence of the desired agonist. When ganglia are incubated with [ 3 H]inositol in the presence of low concentrations of carrier inositol, most of the radioactivity is taken up into cells near the surface of the ganglion. The chapter describes autoradiography. It is a procedure that requires a darkroom, histological processing equipment, and a separate refrigerator to store the autoradiograms during exposure.

Schistosoma mansoni: Morphologic Changes Induced by Maintenance In vitro

Adults of Schistosoma mansoni were incubated in several culture media at various time intervals ranging from 2 to 96 hr. The morphologic changes induced by the incubation were documented using both scanning and transmission electron microscopy. These included changes in the tegument, esophageal cells, and cecum. Variability was noted among worms within experimental groups and the surface changes on single worms were frequently observed to have patchy distribution. Based on morphologic changes observed, culture media were ranked as adequate, mediocre, or inadequate. RPMI-1640 + 50% fetal calf serum, Eagle's MEM with Earle's salts (no serum), and McCoy's 5A Medium + serum were judged adequate. Basal Eagle's Medium, Triple Eagle Medium, NCTC-135, and Earle's Balanced Salt Solution (all with or without serum) were judged mediocre. Hanks' Basal Salt Solution (with or without serum) was judged as severely inadequate. All media tested gave better results in the presence of serum. These factors point to the necessity for the use of carefully selected culture media, as well as adequate controls and sampling techniques in the interpretation of in vitro experiments with S. mansoni.

Chemically defined serum-free media for the cultivation of primary cells and their susceptibility to viruses.

Chemically defined media SFRE-199-1 for the growth and SFRE-199-2 for the maintenance of primary baboon kidney (Bak) cell cultures were formulated by supplementing medium M199 with insulin, sodium pyruvate, zinc sulfate, and increasing arginine-HCl, cysteine, cystine, L-glutamine, L-glutamatic acid, glycine, histidine, tyrosine, and glucose to maximally active nontoxic concentrations. For prolonged maintenance of the cells, physiological pH control, and blocking of excessive lactic acid accumulation in the spent medium of the cell cultures, it is necessary to supplement the medium containing Earle's balanced salts with D-(+)galactose. The cells grew and were maintained equally well on glass or polystyrene surfaces. Selenium, when added to growth medium or substituted for insulin and zinc sulfate, did not stimulate cell growth. Electron microscopy showed that numerous dense particles, approximately 250 to 400 A in diameter, with the appearance of glycogen, were found throughout the cytoplasm in the cells grown in SFRE-199-1 and maintained in SFRE-199-2. Echovirus types 1 to 3, poliovirus types 1 to 3, coxsackievirus types B2, B4, B5, Herpes-virus hominis type 1, simian herpesvirus H. simiae and SA8, and simian adenovirus SV34 when titrated in primary Bak cells and grown and maintained in SFRE-199-1 and 2, respectively, developed titers comparable to those obtained in conventionally grown and maintained cells.