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Biomedical subjects

J H Priest

Publications and source records attributed to J H Priest.

At least 73 records · Page 4Linked to original sources
PubMed1977

Differentiation in human amniotic fluid cell cultures: I: Collagen production.

The collagen produced by differentiated cells cultured from human amniotic fluid was characterized in two ways. By chain composition and by 4-hydroxyproline:3-hydroxyproline isomer ratio, the collagen synthesized by F-type (fibroblast) cells was indistinguishable from that made by cultured fetal dermal fibroblasts. The predominant cells in young amniotic fluid cultures, termed AF-type, produced collagen with a lower isomer ratio, resembling that of basement membrane collage. The chain composition, as determined by chromatography on carboxymethyl cellulose, varied for different cultures of the AF-type, but the major pattern was consistent with that of basement membrane collagen. On the basis of these characteristics, F cells are of fibroblast origin, whereas most AF cells are of a different origin either endothelial or epithelial. Other evidence (Megaw et al., 1977) suggests an epithelial origin for AF cells.

Amniotic Fluid↗
PubMed1977

Differentiation in human amniotic fluid cell cultures: II: Secretion of an epithelial basement membrane glycoprotein.

Cells obtained by amniocentesis for prenatal diagnosis were grown in vitro and examined for the presence of a glycoprotein component epithelial basement membrane. Isolated colonies or clones of amniotic fluid-type cells secrete the glycoprotein, which was identified in association with the cells using indirect immunofluorescent antibody techniques. In addition, the glycoprotein was isolated from tissue culture medium and identified as a component of epithelial basement membranes by passive haemagglutination (PHA) and immunodiffusion assays. Fibroblast-type cells do not secrete the glycoprotein. These results correlate well with the synthesis of type IV collagen by amniotic fluid cells reported in the accompanying paper (Priest et al., 1977) and indicate that amniotic fluid cells are epithelial in origin.

Amniotic Fluid↗
PubMed1976

Dermatoglyphics in mosaic Down's syndrome.

To determine whether quanitative dermal indices are useful in ascertaining the liability for or severity of mosaic Down's syndrome (DS), dermatoglyphics of 107 subjects with proven 46/47,+21 DS were scored by four quantitative dermal indices. The distribution of mosaics by weighted mean percentage of +21 cells ranged from 1 to 95 and was bimodal. Mean maternal age at birth of mosaics (32.9 +/- 7.5 years) was elevated when compared with control maternal ages in the literature. The distribution of quantitative dermal indices for the total mosaic population fell roughly midway between those in the literature for normal and full DS individuals: 73% of mosaics were classified as definitively DS, 21% were in the intermediate range, and 6% were normal. For mosaics who were minimally affected, 24% were DS, 53% intermediate, and 23% normal. One can conclude: (1) For any suspect mosaic, a dermal score in the DS range is highly suggestive of karyotypic pathology. (2) The high prevalence of intermediate scores in normal subjects severely restricts their diagnostic value in screening for mosaics in the general population. For a selected population, such as parents of +21 children, the screening value of quantitative dermal indices remains an open question. Weighted regression analyses demonstrate a highly significant correlation (P less than 0.001) of dermal index score with the weighted mean proportion of +21 cells transformed to the logit scale. One may exploit this correlation to predict the ratio of +21/normal cells in infants, in whom early karyotype evolution can preclude an estimate of the ultimate syndrome based on initial degree of mosaicism. Furthermore, this correlation provides additional indirect evidence that dermal microsymptoms in DS are a reflection of the presence of +21 cells.

Dermatoglyphics↗
PubMed1975

Differences in human X isochromosomes.

In this paper we describe two types of i(Xq), in three patients. A classification is proposed for at least seven different types of human i(Xq)s or X long-arm duplications described by banding in the literature. Type 1 reported here and also in the literature may be the most common. It consists of a single visible centromere, metacentric, length similar to number 3, G-banding interpreted as i(X)(qter leads to cen leads to qter), one C-band like a normal X. Type 2 reported here may not have a counterpart in the literature; it exhibits a single visible centromere, submetacentric, length similiar to number 3, extra G- and C-bands on region ql. The classification summarized in this paper implies that different breakpoints are involved in the production of human X long-arm isochromosomes or duplications. Some include duplications of short arm. Morphological differences in i(Xq)s will complicate their use for studying the effect of X chromosome structure on phenotype, unless differences are defined clearly. It seems important to resolve the question of whether these reported abnormal X chromosomes involve rearrangements between the same or two X chromosomes. We also report X chromosome defects in three generations of a family; both the mother and maternal grandmother of one 45,X,i(Xq)/45,X patient are themselves mosaics for 45,X/46,XX/46,X,r(X). This family suggests that familial predisposition to X chromosome abnormality included isochromosome formation, as well as ring formation and mosaicism.

Adolescent↗
PubMed1970

Distribution of labeled chromatin. I. M 1 and M 2 anaphases of diploid and tetraploid cultured mammalian cells.

The question of whether distribution of chromatids to daughter cells in mitosis is a random or nonrandom process was investigated by study of the distribution of labeled chromatin in anaphase pairs at M(1) and M(2) after a pulse of tritiated thymidine. Diploid and tetraploid rat and diploid human fibroblast-like cells in serial monlayer culture were synchronized by two different methods to "purify" M(1) and M(2) anaphases: metaphase shake, and FUdR block to DNA synthesis followed by exogenous thymidine. Exposed grains of NTB-2 emulsion were counted over M(1) and M(2) anaphase pairs. An analysis (by pair) of diploid M(2) anaphase grain counts showed two discrete populations of daughters with less and with more radioactivity. A similar analysis of diploid M(1) and tetrapolid M(2) anaphases showed a single grain-count distribution. These findings may support a nonrandom model of chromatid segregation for diploid mammalian cells but do not rule out random segregation until sound mathematical models are formulated for expected random grain distributions in M(2) anaphases of cells with differing numbers of chromosomes.

Analysis of Variance↗