Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Entire DC Network
A Genetic Analysis Of Folate Transport In Chinese Hamster Ovary Cells, T Michael Underhill
A Genetic Analysis Of Folate Transport In Chinese Hamster Ovary Cells, T Michael Underhill
Digitized Theses
Chinese Hamster Ovary cells that are about 50x more resistant to the cytotoxic action of methotrexate than wild-type cells were deficient in the ability to take up methotrexate. In the absence of any exogeneous folates these cells require 100-250x the level of folinic acid as do wild-type cells to support growth at a similar level. Two classes of mutants were distinguishable by their revertability for growth on folinic acid and ability to take-up folic acid. Revertants derived from one class were similar to wild-type cells in their ability to grow in medium containing low levels of folinic acid and in …
Determinants Of Critical Power And Anaerobic Work Capacity In Young And Elderly Men, Thomas James Overend
Determinants Of Critical Power And Anaerobic Work Capacity In Young And Elderly Men, Thomas James Overend
Digitized Theses
Determinants of critical power (CP, the theoretical maximal rate of non-fatiguing work) and anaerobic work capacity (AWC, a finite energetic reserve from intra-muscular sources) were determined in young (n = 13, 24.5 y) and elderly men (n = 12, 70.7 y). The purposes of the four studies were to: (1a) determine and compare CP and AWC in young and elderly men; (1b) determine if CP does represent a true maximal rate of non-fatiguing work; (2) determine thigh component cross-sectional areas (CSA) and volumes; (3) determine the strength and strength/CSA ratios of the knee extensors and knee flexors; and (4) identify …
Effects Of Reactive Oxygen Species On The Functional And Electrophysiological Responses Of Cardiac Tissues, Robert Gene Tsushima
Effects Of Reactive Oxygen Species On The Functional And Electrophysiological Responses Of Cardiac Tissues, Robert Gene Tsushima
Digitized Theses
Reactive oxygen species have been implicated in the development of a variety pathological conditions, including myocardial ischemia and reperfusion injury. The present study examined the effects of reactive oxygen species on the functional and electrophysiological responses of cardiac tissues.;Purine/xanthine oxidase and hydrogen peroxide (H{dollar}\sb2{dollar}O{dollar}\sb2{dollar}) caused a concentration-dependent decline in contractile force with a concomitant rise in resting tension in isolated guinea pig hearts. These observations indicate that exogenous reactive oxygen species can cause direct myocardial dysfunction in a concentration-dependent manner.;In addition, purine/xanthine oxidase significantly depressed recovery of contractile function, enhanced resting tension and prolonged the duration of reperfusion arrhythmias. In …
The Generation Of Cytotoxic Tumour Infiltrating Lymphocyte Clones Against Head And Neck Squamous Cell Carcinoma, Henry J. Lapointe
The Generation Of Cytotoxic Tumour Infiltrating Lymphocyte Clones Against Head And Neck Squamous Cell Carcinoma, Henry J. Lapointe
Digitized Theses
73 samples of H&NSCCa were processed for these studies. An enzymatic disaggregation protocol for the flow cytometric analysis of DNA content of tumour whole cell preparations was developed. Analysis of the tumour cell component without the need for incorporation of reference controls provided a more accurate assessment of DNA content of tumour cell populations. Six lines of H&NSCCa were established in vitro from fresh tumour samples. Tumour cell effects on PHA- or IL-2 stimulated proliferation of PBMNCs ranged from 61% and 45% suppression to 4% and 121% enhancement of the proliferative responses respectively. Flow cytometric analysis revealed a down regulation …
Role Of Metallothionein In Chemical Toxicity Mediated By Reactive Intermediates Generated From Xenobiotic And Oxygen Metabolism, Zacharias Emmanuel Suntres
Role Of Metallothionein In Chemical Toxicity Mediated By Reactive Intermediates Generated From Xenobiotic And Oxygen Metabolism, Zacharias Emmanuel Suntres
Digitized Theses
This research was concerned with the role of metallothionein (MT) in chemical toxicity mediated by reactive intermediates generated from xenobiotic and oxygen metabolism. Metallothionein(s) are ubiquitous, low molecular weight, cysteine-rich (30% of total amino acids), metal binding proteins. These proteins have been shown to be important in the regulation of essential metal metabolism and in the detoxication of toxic metals. In the present research it was hypothesized that (i) because of its high cysteinyl thiolate concentration, MT is reactive towards intermediates generated from xenobiotic metabolism; and (ii) the metal (Zn, Cu) released from MT concomitant with the inactivation of metal …
Natural Lta Tumor Cell Resistance To Malignant Conversion By Oncogenesras Andmyc, Alan Bradley Tuck
Natural Lta Tumor Cell Resistance To Malignant Conversion By Oncogenesras Andmyc, Alan Bradley Tuck
Digitized Theses
A tumorigenic, non-metastatic murine fibroblast cell line (LTA) was here used to study aspects of natural cellular resistance to induction of progression to malignancy. The nature of LTA cell growth was established by testing both in vitro and in vivo. In vitro growth showed some but not all characteristic features of transformation (eg. cells showed little contact inhibition of cell growth and were able to multilayer, but were not serum independent). In vivo tumor growth was that of a benign (non-metastatic) fibrosarcoma. Attempts were made to induce LTA cell progression to malignancy by both epigenetic and genetic means. Treatment of …