Medicine and Health Sciences Commons^™

The Effect Of Growth Hormone Release On Plasma And Erythrocyte Selenium And Zinc Levels In Children, Maria Estela Legal De Reid

Chemistry & Biochemistry Theses & Dissertations

Research studies have suggested that selenium may be important in the release of growth hormone, GH. A selenium-containing amino-acid residue, selenocysteine, has been identified as part of the active site of the three isoenzymes (Type I, II and III iodothyronine 5' -deiodinase) responsible for the synthesis of active thyroid hormone, T_3, which is reported to stimulate GH secretion. The importance of zinc in growth is well- documented because of its involvement in transcription and expression of GH and its intermediary, insulin growth factor I or IGF- I. Thus, selenium and zinc levels in plasma may be altered in response …

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 tRNA^asn, tRN^asp, tRNA^his, and tRNA^tyr 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 …

Distribution Of Endosomal, Lysosomal And Mhc Markers In A Monocytic Cell Line Infected With Chlamydia Psittaci, David M. Ojcius, Raymond Hellio, Alice Dautry-Varsat

All Dugoni School of Dentistry Faculty Articles

The intracellular fate of Chlamydia psittaci during infection of a monocytic cell line, THP1, was characterized. Cytochalasin D inhibited phagocytosis of latex beads but had no effect on infection by C. psittaci, and vacuoles expressed the transferrin receptor, suggesting accessibility to the endocytic pathway. Early Chlamydia-containing vacuoles expressed major histocompatibility complex (MHC) class I molecules, and most vacuoles fused with host cell lysosomes, since they expressed LAMP-1 and had acidic pHs. In cells prestimulated with gamma interferon, vacuoles also expressed MHC class II molecules, suggesting that the monocytes might effectively process Chlamydia-derived antigens for presentation by MHC class I and …

A Heterodimer Of Thioredoxin And Ib2 Cooperates With Sec18p (Nsf) To Promote Yeast Vacuole Inheritance, Zuoyu Xu, Andreas Mayer, Eric Muller, William Wickner

Dartmouth Scholarship

Early in S phase, the vacuole (lysosome) of Saccharomyces cerevisiae projects a stream of vesicles and membranous tubules into the bud where they fuse and establish the daughter vacuole. This inheritance reaction can be studied in vitro with isolated vacuoles. Rapid and efficient homotypic fusion between saltwashed vacuoles requires the addition of only two purified soluble proteins, Sec18p (NSF) and LMA1, a novel heterodimer with a thioredoxin subunit. We now report the identity of the second subunit of LMA1 as IB2, a previously identified cytosolic inhibitor of vacuolar proteinase B. Both subunits are needed for efficient vacuole inheritance in vivo …

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. …