A required program in geriatrics for medical students.

Very few medical schools in the United States have compulsory training in geriatrics for medical students. A program has been developed in the Department of Family Practice at Southern Illinois UniversitySchool of Medicine. This has become a required component of the undergraduate family practice clerkship.

Development of improved media and culture conditions for clonal growth of normal diploid cells.

Multiplication of normal diploid cells in culture is controlled by a complex set of interacting extracellular variables. The amount of serum protein needed for colony formation by such cells is affected directly by many of the other variables, including the nature of the culture surface, the type of trypsinization procedure used, and the qualitative and quantitative composition of the culture medium. By a sequential process of adjusting all of these variables to optimum values for cellular multiplication with minimal amounts of serum protein, we have been able to obtain clonal growth of normal human and chicken cells with less than 500 microgram per ml dialyzed serum protein.

Clonal growth of chinese hamster cell lines in protein-free media.

A protein-free synthetic medium, MCDB 301, has been developed for clonal growth of Chinese hamster ovary cell lines. Medium F12 was developed originally for that purpose, but later failed to support good growth without small amounts of serum protein. Growth was restored by the addition of nonphysiological amounts of commercially prepared thyroxine or smaller amounts of the trace element selenium.

Improved medium for clonal growth of human diploid fibroblasts at low concentrations of serum protein.

A new medium (MCDB 104) has been developed which will support clonal growth of WI-38 cells at concentrations of serum protein as low as 25 micrograms per ml (equivalent to 0.05% serum). The principal factors responsible for reduction of the protein requirement are: (a) adjustment of all nutrient concentrations in medium F12 to experimentally determined optimum values for WI-38 cells; (b) supplementation with trace elements; (c) replacement of hypoxanthine and folic acid with adenine and folinic acid; and (d) coating of the culture surface with polylysine.

Critical adjustment of cysteine and glutamine concentrations for improved clonal growth of WI-38 cells.

Clonal growth of WI-38 cells with a plating efficiency of 45% has been achieved in a synthetic nutrient mixture (MCDB 102) supplemented with either whole or dialyzed fetal bovine serum precisely. Deviation by a factor of three in either direction from the optimum concentration (9.0 x 10(-5) M) eliminates essentially all clonal growth.

Methods for reducing the serum requirement for growth in vitro of nontransformed diploid fibroblasts.

The amount of serum protein required for clonal growth of normal diploid human and chicken fibroblasts has been reduced more than 90% by development of improved synthetic media and culture conditions. The following has contributed significantly to the reduction: (1) replacement of specific serum proteins with defined small molecular nutrients; (2) precise quantitative balance of all defined nutrients for optimal growth of single cells of each type under consideration; (3) modification of the culture substrate; (4) improvement of the cell harvesting technique. By combining these improvements, optimal growth of human fibroblasts (fetal lung, newborn foreskin, amniotic fluid) and chicken embryo fibroblasts occurs in synthetic media supplemented with 500 microgram/ml dialyzed fetal bovine serum protein [equivalent to 1% (v/v) whole serum].

Stimulation of clonal growth of normal fibroblasts with substrata coated with basic polymers.

Improved media have reduced the amount of serum protein required for clonal growth of normal human and chicken fibroblast-like cells. In the presence of limiting amounts of serum protein, attachment of colonies to tissue culture plastic surfaces is weak. Treatment of the culture surface with polylysine or other basic polymers causes the cells to adhere much more tightly.

Selenium is an essential trace nutrient for growth of WI-38 diploid human fibroblasts.

The trace element selenium is essential for clonal growth of diploid fibroblasts from human fetal lung (WI-38) in media containing small amounts of serum protein. Maximum growth stimulation is obtained when 30 nM neutralized selenious acid is added to a synthetic medium containing 1.5 mg/ml of dialyzed fetal bovine serum protein (equivalent to a 3% serum concentration).

Albumin replacement by fatty acids in clonal growth of mammalian cells.

Clonal growth of Chinese hamster strain CHD-3 cells in a synthetic nutrient mixture supplemented with 10 micrograms of purified fetuin per milliliter exhibits an apparent requirement for serum albumin. The albumin can be replaced by linoleic acid, which occurs as a tightly bound component of most albumin preparations. Linolenic acid and corn oil can also replace albumin, while oleic acid and esters of linoleic and linolenic acids cannot.