A survey of surface glycoproteins of four human squamous cell carcinoma lines

The major cell surface glycoprotein components of four new cell lines derived from human squamous cell carcinomas of the head and neck (TR126, TR131, TR138, TR146, Rupniak, H. T. et al., JNCI 75, 621-635, 1985) were identified by three complementary labelling methods. The profile of labelled glycoprotein components was very similar in the four cell lines, although quite large quantitative differences in individual bands were seen. Two galactoproteins, designated GPC-130 and GPC-80 (apparent molecular weight X 10(-3)) were labelled by galactose oxidase/NaB [3H]4 but in all four lines only GPC-130 was prominent. The cell surface galactose and N-Acetylgalactosaminyl residues of glycoproteins were quite highly sialylated, as the galactose oxidase/NaB [3H]4 reaction was increased by between 3- and 6-fold after neuraminidase treatment. The neuraminidase-galactose oxidase/NaB [3H]4 and NaIO4/NaB [3H]4 methods identified a complex profile of glycoprotein components, with very high molecular weight sialogalactoconjugates being prominent. The major sialoglycoproteins were GPC-205, GPC-175, GPC-155, GPC-90 and GPC-70 and in addition, GPC-130 and GPC-80 showed enhanced labelling. Lactoperoxidase catalyzed the iodination of a similar profile of high molecular weight glycoprotein components, with GPC-205 and GPC-175 being prominent in TR126, TR131 and TR146 but less evident in TR138. Overall, the profile of labelled glycoprotein components was similar to the pattern seen in the well differentiated transitional carcinoma lines RT112 and RT4 (Steele, J. G. et al., Biochim. Biophys. Acta. 732, 219-228, 1983).     

Comparing models and observations of shelf plankton

In a previous paper (Solow and Steele, J. Plankton Res., 17,1995), the differences between variability in zooplankton biomassand in copepod stage structure were demonstrated using datafrom the northern North Sea. Here, a model is used to describethe underlying demographic processes and the effects of interannualphysical variability. Comparison of output with observationscan test the theory and so help to reconcile the apparent contradictionbetween great variability and persistence in these populations.     

Anucleolate frog embryos contain ribosomal DNA sequences and a nucleolar antigen

Previous studies of Xenopus laevis embryos homozygous for the nucleolar deletion mutation have concluded that these embryos contain few, if any, copies of the genes for the 18 S and 28 S ribosomal RNAs. Using hybridization to restriction endonuclease digests of DNA it is found, in fact, that a small amount of ribosomal DNA is still present in such embryos. The ribosomal DNA in these embryos appears to include a few normal repeats together with a variety of unusual fragments containing either spacer or gene sequences. An antibody found in the serum of a scleroderma patient reacts with an antigen localized in the nucleoli of wild-type embryos. In anucleolate embryos this antigen is found in the so-called pseudonucleoli and in many small bodies in the nuclei.     

Comparison of serum oestrogen concentrations in post-menopausal women taking oestrone sulphate and oestradiol.

Mean serum concentrations of oestradiol-17beta, oestrone, and oestrone sulphate in postmenopausal women were the same when measured up to six hours after treatment with either piperazine oestrone sulphate 1.5 mg or oestradiol valerate 2 mg. Maximum concentrations of oestradiol were less than those of oestrone, but oestrone sulphate reached concentrations about 30 times higher than those of oestrone. The rapid conversion of oestradiol valerate to oestrone and oestrone sulphate does not support the suggestion that in menopausal women oestradiol is less likely to be associated with a risk of endometrial carcinoma than oestrone sulphate, since the two preparations appear to become identical after ingestion.     

Peopling of the Americas: paleobiological evidence.

A subjective and bivariate analysis of 8500-10,000-year-old human fossil remains from North America substantiates that the fossils' closest affinities are with Asian populations. Within North American prehistoric Indian populations, increasing brachycephalization and the possible development of a larger, broader face are two structural trends that can be identified. In those respects where Paleo-Indian specimens differ from modern northern Asians and North American Indians, they tend to resemble southern Asian and European populations. These assessments generally support the inference that populations entered the New World relatively recently but before the modern northern Asian and North American features were fully developed. Based on the data examined, no date can be specified for time of entrance of the first populations, nor can the number of founding populations be discerned.