Effect of matrigel on the tumorigenicity of human breast and ovarian carcinoma cell lines

The effect of Matrigel, a solubilised tissue basement membrane extract, has been investigated on the tumorigenicity of 3 breast (MCF-7, T47D and MDA.MB.231) and 5 ovarian [PEO1, PEO1 cDDPr, PEO4, PEO14 and OV(hyg)CAR3] carcinoma cell lines. In the absence of Matrigel, the PEO14 and MDA.MB.231 cell lines produced take rates of 30% and 50%, respectively, while the other cell lines either did not develop or only occasionally developed as tumours. With Matrigel, 100% take rates were achieved for 7 of the 8 cell lines (MCF-7, T47D, MDA.MB.231, PEO1, PEO1 cDDPr, PEO4 and PEO14); in the remaining cell line [OV(hyg)CAR3] 2/6 (33%) tumours grew. Xenografts established with Matrigel could be transferred into recipient animals and grown in the absence of Matrigel, suggesting that Matrigel is necessary only for initial establishment of tumours. Furthermore, cells which had been re-established from a T47D xenograft and then inoculated into mice without Matrigel showed a take rate greater than that of the original cell line but less than that of the xenograft. In conclusion, Matrigel has proven to be extremely useful in establishing a variety of cell lines as xenografts. © 1996 Wiley-Liss, Inc.     

D2 dopamine receptor gene and obesity

The prevalence of Taql A D₂ dopamine receptor (DRD2) alleles was determined in 73 obese women and men. In this sample with a mean body mass index of 35.1, the A1 (minor) allele of the DRD2 gene was present in 45.2% of these nonalcohol, nondrug abusing subjects. The DRD2 A1 allele was not associated with a number of cardiovascular risk factors examined, including blood lipids (cholesterol, high-density lipoprotein [HDL]- and low-density lipoprotein [LDL]-cholesterol, and triglycerides). However, phenotypic factors characterized by the presence of parental history and postpuberty onset of obesity as well as carbohydrate preference were associated with obese subjects carrying the A1 allele. The cumulative number of these three factors was positively and significantly (p < .0002) related to A1 allelic prevalence. The data showing an association of the minor allele of the DRD2 gene with phenotypic characteristics suggest that this gene, located on q22–q23 region of chromosome 11, confers susceptibility to a subtype of this disorder. © 1994 by John Wiley & Sons, Inc.     

Smooth muscle cell differentiation in vitro: models and underlying molecular mechanisms

Development of in vitro models by which to study smooth muscle cell (SMC) differentiation has been hindered by some peculiarities intrinsic to these cells, namely their different embryological origins and their ability to undergo phenotypic modulation in cell culture. Although many in vitro models are available for studying SMC differentiation, careful consideration should be taken so that the model chosen fits the questions being posed. In this review, we summarize several well-established in vitro models available to study SMC differentiation from stem cells and outline novel mechanisms recently identified as underlying SMC differentiation programs.     

Isolation and characterization of toxic fractions from Brucella abortus.

Two types of toxic fractions, protein-rich and carbohydrate-rich, were isolated from attenuated (strain 19) and virulent (strain 2308) Brucella abortus organisms. Polyacrylamide gel electrophoresis of the protein-rich fraction, in the presence and absence of sodium dodecyl sulfate, revealed qualitative and quantitative differences in the protein bands derived from the attenuated and virulent strains. Sodium dodecyl sulfate-gel electrophoresis indicated that the major differences between these protein fractions were in the molecular weight range from 14,000 to 40,000. Immunoelectrophoresis of these fractions from the attenuated and virulent strains revealed differences in the antigenic spectrum. Polypeptides in the carbohydrate-rich fraction could be visualized on polyacrylamide gels only when reacted with fluorescamine before electrophoresis. Immune sera did not precipitate the components of the carbohydrate-rich fraction. Intradermal injecttion of the protein and carbohydrate-rich fractions resulted in different types of skin lesions in guinea pigs, i.e., edematous/erythematous and necrotic lesions, respectively. Fractions derived from attenuated and virulent strains of B. abortus were equally toxic in the guinea pig skin test. The toxic activity of both types of fractions was susceptible to pronase and heat treatment.