Primary culture of human esophageal epithelial cells

Primary cultures and serial passages of nontumorous adult human esophageal epithelial cells derived from surgically resected esophagi of patients with esophageal cancer have been developed. Disaggregated cells obtained by means of tryptic digestion lasting for 90 min grew to confluency in medium RITC 80-7 supplemented with 10% fetal bovine serum (FBS). Such primary cultures were established from more than 20 donors, and could be passaged 3 to 5 times. Fibroblastic contamination was almost eliminated by careful sampling, and it was possible to perform the growth response or serial passages without fibroblastic overgrowth. Serum-free medium RITC 80-7 supplemented with fibronectin (FN) and bovine serum albumin (BSA) also supported the growth of esophageal epithelial cells, but was not sufficient for serial passages. Among growth promoting factors in medium RITC 80-7, the epidermal growth factor (EGF) was highly stimulatory to growth. Insulin, transferrin, FN and BSA also enhanced cell growth and/or attachment. The epithelial nature of the cultured cells was confirmed by transmission electron microscopy and indirect immunofluorescent staining with antikeratin antibody. The majority of the cultured cells were diploid.

Adrenoleukodystrophy: detection of increased very long chain fatty acids by high-performance liquid chromatography

Using high-performance liquid chromatography, adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN) were diagnosed by the analysis of fatty acids in sphingomyelin. The analytical method was simple, sensitive and accurate. In ALD and AMN patients, very long chain fatty acids (C26:0, C25:0 and C24:0 on the base of C22:0) were elevated not only in plasma and erythrocyte membranes but also in whole blood samples. An increase of long chain fatty acids was also shown in sphingomyelin of cultured skin fibroblasts. One heterozygote for ALD showed intermediate values between homozygotes and controls. Thus, high-performance liquid chromatography is a valuable method to detect increased long chain fatty acids for the diagnosis of ALD or AMN.

Partial purification and properties of proteases from defatted soybean flour

Four chromatographically different proteases were partially purified from defatted soybean flour, and their pH optima were around 5.0 to 5.6 using casein as the substrate. These soybean proteases were designated S1, S2, S3 and S4 according to their order of elution from a DEAE-cellulose column. Each gave a single peak of caseinolytic activity on a Sephadex G-200 column chromatogram, and corresponded to the molecular weights of about 50,000(S1), 35,000(S2), 60,000(S3) and 200,000(S4). The proteases could hydrolyze casein and poly-Glu. alpha-Casein was more rapidly hydrolyzed than beta-casein, but the esters or dipeptide could not be hydrolyzed. Aliquots of 10(-3) M Hg2+, Cu2+ and Zn2+ inhibited the caseinolytic activities by 70% to 90%, while other cations, Mn2+, Mg2+, Ca2+ and Ni2+, at the same concentration did not. SPI (10(-5) M) inhibited 80--90% of their activities, and EPNP (10(-5) M) inhibited their activities 30--60%, but DFP (10(-3) M), SSI (10(-3) M), PCMB (10(-4) M), NEM (10(-3) M) and EDTA (10(-3) M) were not inhibitory. The above results indicate that proteases S1, S2, S3 and S4 from defatted soybean flour can be classified as acid proteases.

Alpha-linoleate and photosynthetic activity in Chlorella protothecoides

Green cells of Chlorella protothecoides grown in nitrogen-rich low glucose media may be reversibly transformed to entirely chlorophyll-less cells in low nitrogen high glucose media. Photosynthetic rates and fatty ester compositions were determined during light and dark bleaching and during greening. Linolenic acid content remained unchanged during greening or bleaching. During light greening chlorophyll content and photosynthetic activity increased while oleic acid content decreased dramatically. As a result, the percent composition of linolenate appeared to parallel photosynthetic capability. Implication of alpha-linolenate in oxygen production, therefore, can not be based upon fatty acid percentage composition data alone.