Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Recent experimental work has indicated that the thymus in late fetal and early neonatal life plays a major role in the development of mechanisms of immunity. To date, however, no study of the ultrastructure of the prenatal thymus has been reported in the literature, and histochemical and cytochemical studies of this early period are fragmentary. Therefore, in an effort to extend present knowledge of thymic differentiation and function during its early development, the thymus in the golden hamster (Mesocricetus auratus) was studied by selected histochemical methods and by electron microscopy from 9 1/2 days post coitum through 24 hours post partum. Histochemical techniques for the light microscopy included the periodic acid-Schiff technique with salivary digestion control for glycogen, the methyl green-pyronin technique as an indicator for protein synthesis, the sudan black B technique for determination of total unbound lipid, the Nile blue and oil r ed 0 techniques for deter mination of neutral lipid, and the Elftman t echnique for determination of phospholipid. Material was prepared for electron microscopy by fixation for one hour in l% osmium tetroxide (Millonig, 1963), dehydration in graded acetones followed by propylene oxide, and embedding in Maraglas epoxy resin (Freeman and Spurlock, 1962). Grids prepared from these specimens were stained either with 1% phosphotungstic acid in 95% alcohol, or with lead citrate (Reynolds, 1963). They were scanned with either an R.C.A. EMU 2-B electron microscope or a Siemens Elmiskop I. [TRUNCATED] / 2031-01-01

published_or_final_version / Anatomy / Master / Master of Philosophy

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

Thesis (Ph.D.)--Tufts University, 2004. / Adviser: Alice H. Lichtenstein. Submitted to the School of Nutrition Science and Policy. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (Ph. D.)--University of Hong Kong, 1992.

Thesis (M. Phil.)--University of Hong Kong, 1993.

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Quantitative relationships between blood flow velocity, vessel diameter, width of the peripheral plasma layer and induction of thrombus formation were studied in small blood vessels of the retrolingual membrane and intestinal mesentery of the frog, Rana Pipiens, and of the cheek pouch of the golden hamster, Mesocricetus auratus. Blood flow velocity was measured by a modification of the technique described by Hugues (Arch. Int. de Physiol. 61: 565, 1953). Internal vessel diameters and widths of the total peripheral plasma layer were measured with an ocular micrometer. Thrombus thresholds were determined by graded electrical stimulation. Determinations were made on 202 vessels in retrolingual membranes of frogs prepared by single pithing. In 95 arterioles (diameters from 10 to 40 microns), the mean flow velocity was 2.84 mm/sec. and the mean volume flow rate, 1.68xl0-3 cu mm/sec. The mean width of the total peripheral plasma layer was 3.6 microns and its ratio to mean vessel diameter was 1:6. In 107 venules (diameters from 10 to 50 microns), the mean flow rate was 1.20 mm/sec. The mean volume flow rate was 1.02x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 4.1 microns and its ratio to mean vessel diameter was 1:7.4. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.3 and 1:1.6 respectively. Measurements were made on 100 mesenteric vessels of frogs prepared by single pithing. In 50 arterioles (diameters from 15 to 45 microns), the mean velocity was 3.77 mm/sec. The mean volume flow was 3.05xlo-3 cu mm/sec. The mean width of the total peripheral plasma layer was 2. 7 microns and its ratio to mean vessel diameter was 1:11.5. In 50 venules (diameters from 20 to 50 microns), the mean velocity was 1.55 mm/sec. and the mean volume flow rate, 1.76x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 6.7 microns and its ratio to mean vessel diameter was 1:5.3. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.3 and 1:1.7 respectively. A total of 109 mesenteric vessels were studied in frogs anesthetized with urethane. In 55 arterioles (diameters from 15 to 45 microns), the mean velocity was 3.28 mm/sec. The mean volume flow was 2.87x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 3.2 microns and its ratio to mean vessel diameter was 1:9.3. In 54 venules (diameters from 20 to 50 microns), the mean flow rate was 1.61 mm/sec. and the mean volume flow, 1.83x10-3 cu mm/sec. The mean width of the total peripheral plasma layer was 5.6 microns and its ratio to mean vessel diameter was 1:5.9. The ratios of mean arterial to mean venous velocity and volume flow were 1:2.0 and 1:1.5 respectively. In these three series of studies in the frog, no relationship was clearly apparent between velocity and either vessel diameter or width of the peripheral plasma layer in arterioles. Suggestions of a direct relationship between velocity and peripheral plasma layer in veins, however, were evident. In all cases, and in both arterioles and venules, vessel diameter and peripheral plasma layer were clearly and directly related. The effects of flow velocity changes on width of the total peripheral plasma layer in individual vessels were studied in 26 arterioles of the hamster cheek pouch. Blood flow was varied by means of a cuff described by Copley (Biorheology 1: 3, 1962). A direct relationship between velocity and width of the peripheral plasma layer was clearly demonstrated. Thrombus thresholds were determined in mesenteric vessels of the frog. In 103 arterioles (diameters from 20 to 140 microns), the mean strength of stimulus necessary to produce a platelet thrombus was 24.8 volts with an amperage of 0.18 milliamperes. In 100 venules (diameters from 20 to 140 microns), the mean strength of stimulus necessary was 20.7 volts with an amperage of 0.12 milliamperes. Possible relationships of thrombus thresholds to flow velocity in mesenteric arterioles and venules are discussed. / 2031-01-01

by Ng Yuen Keng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 141-148). / Table of contents --- p.1 / List of figures --- p.5 / List of tables --- p.12 / List of abbreviations --- p.13 / Abbreviation table for amino acids --- p.16 / Chapter Chapter 1 --- Literature Review --- p.17 / Chapter 1.1 --- Introduction --- p.17 / Chapter 1.2 --- The Hematopoietin/cytokine receptor superfamily --- p.20 / Chapter 1.3 --- The PRLR protein --- p.22 / Chapter 1.3.1 --- The receptor size --- p.22 / Chapter 1.3.2 --- Primary structure --- p.22 / Chapter 1.3.3 --- Structure of the extracellular domain --- p.26 / Chapter 1.3.4 --- Structure of the cytoplasmic domain --- p.30 / Chapter 1.3.5 --- Characteristics of specific PRL binding to PRLR --- p.32 / Chapter 1.5 --- The PRLR gene --- p.33 / Chapter 1.6 --- Heterogeneity of PRLR --- p.33 / Chapter 1.7 --- Signal transduction of PRLR --- p.35 / Chapter 1.7.1 --- JAK: a novel family of cytoplasmic protein tyrosine kinases --- p.35 / Chapter 1.7.2. --- Interaction between JAK2 and PRLR --- p.37 / Chapter 1.7.3 --- STAT proteins: mediators of PRL-dependent gene transcription --- p.37 / Chapter 1.7.4 --- Other signaling pathways of PRLR --- p.38 / Chapter 1.7.5 --- Future prospects on PRLR signaling --- p.38 / Chapter 1.8 --- Regulation of PRLR gene expression --- p.39 / Chapter 1.9 --- Objective of cloning the PRLR cDNA in male Syrian golden hamster --- p.42 / Chapter Chapter 2 --- PCR cloning of hamster PRLR cDNA fragment from adult male hamster liver --- p.44 / Chapter 2.1. --- Introduction --- p.44 / Chapter 2.2. --- Materials and Methods --- p.45 / Chapter 2.2.1 --- Primer design and PCR strategy --- p.45 / Chapter 2.2.2 --- Collection of liver --- p.46 / Chapter 2.2.3 --- Reverse transcription of polyadenylated RNA --- p.46 / Chapter 2.2.4 --- Nested PCR --- p.47 / Chapter 2.2.5 --- Southern analysis of the PCR products --- p.48 / Chapter 2.2.6 --- Subcloning of PCR product --- p.49 / Chapter 2.2.7 --- Sequence determination of the positive recombinant clone --- p.49 / Chapter 2.2.8 --- Sequence alignment and homology comparison --- p.50 / Chapter 2.3 --- Results --- p.55 / Chapter 2.3.1 --- Nucleotide sequence alignment and primer design --- p.55 / Chapter 2.3.2 --- Nested PCR --- p.55 / Chapter 2.3.3 --- Subcloning of the PCR product --- p.56 / Chapter 2.3.4 --- Analysis of nucleotide and predicted amino acid sequences --- p.56 / Chapter 2.4 --- Discussion --- p.66 / Chapter Chapter 3 --- Nucleotide sequence determination of the 5' and the 3' ends of hamster PRLR cDNA --- p.69 / Chapter 3.1 --- Introduction --- p.69 / Chapter 3.2 --- Materials and Methods --- p.71 / Chapter 3.2.1 --- Collection of liver --- p.71 / Chapter 3.2.2 --- Total RNA preparation and poly (A) + RNA isolation --- p.72 / Chapter 3.2.3 --- Double stranded cDNA synthesis --- p.73 / Chapter 3.2.4 --- Adaptor ligation --- p.74 / Chapter 3.2.5 --- 5´ة and 3' RACE PCR --- p.74 / Chapter 3.2.6 --- Cloning of the RACE PCR products --- p.76 / Chapter 3.2.7. --- Sequence determination of the RA CE PCR products --- p.77 / Chapter 3.2.8. --- Sequence analysis of the RACE PCR products --- p.78 / Chapter 3 .2.9 --- Northern blot analysis of hamster PRLR mRNA in male hamster tissues --- p.79 / Chapter 3.3 --- Results --- p.79 / Chapter 3.1.1 --- RNA preparation and double stranded cDNA synthesis --- p.79 / Chapter 3.3.2 --- RACE PCRfor the 5' and the 3' ends of hamster PRLR cDNA --- p.84 / Chapter 3.3.3 --- Cloning of the 5' and 3'RACE PCR products --- p.92 / Chapter 3.3.4 --- Sequence determination of the RACE PCR products --- p.92 / Chapter 3.3.5 --- Nucleotide sequence analysis of hamster PRLR full length cDNA --- p.101 / Chapter 3.3.6 --- Northern blot analysis of hamster PRLR --- p.101 / Chapter 3.4 --- Discussion --- p.106 / Chapter Chapter 4 --- Attempts to study the PRLR gene expression in male hamster tissues --- p.113 / Chapter 4.1 --- Introduction --- p.113 / Chapter 4.2 --- Materials and Methods --- p.115 / Chapter 4.2.1 --- Collection of tissues --- p.115 / Chapter 4.2.2 --- Total RNA preparation and poly (A)+ RNA isolation --- p.116 / Chapter 4.2.3 --- Reverse Transcription --- p.116 / Chapter 4.2.4 --- Polymerase chain reaction for detecting the presence of hamster PRLR cDNA in various tissues --- p.117 / Chapter 4.2.5 --- Nested PCR for detecting heterogeneity in PRLR cDNA sizes in various tissues --- p.117 / Chapter 4.2.6 --- Analysis and quantitation of PCR products --- p.118 / Chapter 4.3 --- Results --- p.119 / Chapter 4.4 --- Discussion --- p.134 / Chapter Chapter 5 --- General Discussion --- p.137 / References --- p.141 / Appendices --- p.149 / Chapter I. --- "Stock solution preparation (Sambrook et al., 1989)" --- p.149 / Chapter II. --- List of primers --- p.152 / Primers for sequence determination --- p.152 / "Primer for first strand cDNA synthesis and 3' RACE PCR (Frohman et al., 1988 and Loh et al.,1989)" --- p.152 / "Primers for amplifying the actin cDNA fragment (Chan et al.,1995)" --- p.152 / Primers used for PCR-cloning and semi-quantitative analysis of hamster PRLR cDNA --- p.153 / Chapter III. --- "First strand cDNA synthesis primer, cDNA adaptor and adaptor primers used in the 5' and3' end sequence determinations of hamster PRLR cDNA" --- p.154 / Chapter IV. --- "Multiple cloning sites of the pCRII (Invitorgen), pUC 18 (Pharmacia) and pBluescript SK+ vectors (Clontech)" --- p.155 / Chapter VI. --- Nucleic acid molecular weight size markers --- p.158

No description available.

Whey protein isolates (WPI) have been indicated to have potent cholesterol lowering and antioxidative properties. Such effects, however, are not consistently observed, which could be the result of major differences in the processing, isolation and composition of WPI. Moreover, the mechanisms of action or the bioactive component(s) in WPI are poorly understood although the relatively high cysteine content in WPI has been suggested to play an important role. Although high dietary cysteine has been shown to lower plasma homocysteine concentrations, the impact of WPI in this regard has not been investigated. The overall objective of this thesis was to examine the antioxidative and plasma cholesterol and homocysteine lowering properties of two WPI that were produced via different industrial processing and isolation techniques with the milk protein, casein, used as the control protein. We also examined for the mechanism(s) of action of WPI in terms of possible antioxidative, and plasma cholesterol and homocysteine lowering effects. In this regard, the intake of bovine serum albumin (BSA), a major cysteine-rich whey protein was also studied since this protein has been implicated as a key bioactive component for the antioxidant effects of WPI. Four studies were performed. The first involved the characterization of a variety of commercially prepared WPI by high performance capillary electrophoresis for identification of two WPI products that showed major differences in protein composition for subsequent feeding trials. Most of the WPI had similar characteristic electrophoretic profiles, however, significant differences in protein and macronutrient (Ca, Mg, P) composition were noted in two commercial WPI that were chosen as the test proteins in subsequent feeding trials. In the first two feeding studies, hamsters were fed different commercial WPI or milk protein (BSA or casein) containing diets that were either matched or unmatched in terms of macro