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Full-Text Articles in Medicine and Health Sciences
The Cellular And Molecular Dynamics Of The Queuosine Modification In Transfer Rna: Definition, Modulation, Deficiencies And Effect Of The Queuosine Modification System, Rana C. Morris
Theses and Dissertations in Biomedical Sciences
The presence of the queuosine modification in the wobble position of tRNAasn, tRNasp, tRNAhis, and tRNAtyr is associated with a decrease in cellular growth rate, an increase in the ability to withstand environmental stress, and differentiation of pleuripotent cells into mature phenotypes. The loss of this normal modification is strongly correlated with neoplastic transformation and tumor progression of a wide variety of cancers.
The "normal" system for formation of the queuosine modification in tRNA was studied in human fibroblast cell cultures and in mouse, rat and human liver tissues. The queuosine modification system …
Choline Acetyltransferase And Carnitine Acetyltransferase Activity In Human Spermatozoa During Capacitation, Lisa A. Eccles
Choline Acetyltransferase And Carnitine Acetyltransferase Activity In Human Spermatozoa During Capacitation, Lisa A. Eccles
Theses and Dissertations in Biomedical Sciences
The regional distribution of ChAT activity in human spermatozoa is altered during in vitro capacitation and it correlates with the fertilizing potential of sperm.
Regional immunoreactivity in human spermatozoa as assessed by fluorescent immunocytochemistry was compared with ChAT and CaAT activity determined by enzymatic methodologies. Increasing proportions of sperm exhibited ChAT immunoreactivity along the equatorial region with a concomitant decrease in ChAT reactivity in the midpiece. Also, competitive studies with unlabeled ChAT blocked the equatorial region labeling; the unlabeled CaAT blocked staining along the midpiece region of the tail, suggesting some cross-reactivity of the ChAT antiserum with the CaAT enzyme. …