Search PubMed⌕ Search

Biomedical subjects

R M Wright

Publications and source records attributed to R M Wright.

77 records · Page 5Linked to original sources
PubMedDate not supplied

Reversible pseudohyphal growth in haploid Saccharomyces cerevisiae is an aerobic process.

Pseudohyphal growth in Saccharomyces cerevisiae has been postulated to be an adaptation to foraging for nitrogen during nitrogen starvation. This process was described as a strictly diploid phenomenon which did not occur in haploid yeast cells and was under the genetic control of both the mating-type locus and a group of five genes, the BUD genes, regulating bud formation. We have also observed a dimorphic growth pattern in yeast growing on various nitrogen-limiting synthetic media. However, and in contrast to a previous report, we find that pseudohyphal growth is not precluded in haploid cells. We demonstrate that haploid pseudohyphal growth is strictly oxygen-dependent and is rapidly reversible, defining pseudohyphal growth as a reversible developmental pathway in yeast.

Haploidy↗
PubMedDate not supplied

A multi-plane scout sequence using flash imaging.

A new pulse sequence is presented for multi-plane imaging which simultaneously acquires images in the axial, coronal, and sagittal planes. Combined with FLASH imaging or other similar techniques, T1- and T2-weighted images in all three planes can be acquired in approximately 12 and 30 seconds, respectively. The sequence is easily implemented by modifying a multi-slice sequence to provide a rotation of gradient assignments between slice excitations. This sequence has been used extensively as a rapid "scout" scan. Several clinical examples are included.

Arachnoid↗
PubMedDate not supplied

MR imaging of a false carotid aneurysm.

Two months after a gunshot wound to the head of a 12-year-old boy, MR imaging outlined an asymptomatic false aneurysm of the carotid artery. The scan's ability to image in multiple planes with noninvasive visualization of pulsatile vessel flow suggests its use for follow-up examinations of traumatic injuries to the head or neck.

Carotid Artery Diseases↗
PubMedDate not supplied

Assignment of the gene for human intra-acrosomal protein SP-10 to the p12----q13 region of chromosome 11.

The human sperm antigen SP-10 is a testis-specific, intra-acrosomal protein associated with the membranes of the acrosomal vesicle. The molecule has been designated a "primary vaccine candidate" by a World Health Organization (WHO) Taskforce on Contraceptive Vaccines. cDNA cloning and sequencing have indicated that SP-10 is encoded by a 795-base-pair (bp) reading frame that predicts a 265-amino acid protein of 28.3 kd. In this study, we used a 634-bp fragment (bp 68 through 700, amino acids 3 through 222) of the SP-10 sequence to probe, by Southern blotting, EcoRI-digested DNA from 33 mouse/human somatic cell hybrids involving 16 unrelated human cell lines and 4 mouse cell lines. The hybrids were characterized by karyotypic analysis and by mapped enzyme markers. The presence or absence of positive human bands was scored on the blots and the percent of concordance and discordance with a specific human chromosome was determined. The DNA probe for SP-10 showed a concordance of 31 and a discordancy of 0 for human chromosome 11, mapping SP-10 unequivocally to this chromosome. The hybrid XER-7 with the 11/X translocation: 11p12 or 11p11----11qter:: Xq11----Xqter and the hybrid EXR-5CSAZ with the X/11 translocation: Xpter----Xq22::11q13----11qter localized the SP-10 gene to the p12----q13 region. The SP-10 locus has been assigned the gene symbol ACRV1 (acrosomal vesicle protein-1).

Acrosome↗