Hemoglobin-based oxygen carriers (HBOCs) are of great interest for their potential as a safer alternative to blood transfusions. To overcome the vasoactivity associated with small HBOCs, our group is interested in connecting two hemoglobin tetramers together, forming “bis-tetramers”. Bis-tetramers have previously been synthesized by our group, but yield and purity of the resulting solutions have been low and hindered their usefulness for trials. A new cross-linker was designed in an attempt to improve yield. This thesis describes the synthesis of an acyl phosphate cross-linker N-[bis(sodium methyl phosphate)isophthalyl]-4-azidomethylbenzoate (5), its modification of hemoglobin and subsequent purification attempts of the resulting solution. Cross-linker 5 was found to be selective to β-β-crosslinking and produced singly modified subunits as byproducts. Attempts to purify the resulting reaction mixture by heating resulted in the decomposition of the azide group on the cross-linker, which was critical for the coupling step. Efforts to overcome this problem were unsuccessful.

Hemoglobin-based oxygen carriers (HBOCs) are of great interest for their potential as a safer alternative to blood transfusions. To overcome the vasoactivity associated with small HBOCs, our group is interested in connecting two hemoglobin tetramers together, forming “bis-tetramers”. Bis-tetramers have previously been synthesized by our group, but yield and purity of the resulting solutions have been low and hindered their usefulness for trials. A new cross-linker was designed in an attempt to improve yield. This thesis describes the synthesis of an acyl phosphate cross-linker N-[bis(sodium methyl phosphate)isophthalyl]-4-azidomethylbenzoate (5), its modification of hemoglobin and subsequent purification attempts of the resulting solution. Cross-linker 5 was found to be selective to β-β-crosslinking and produced singly modified subunits as byproducts. Attempts to purify the resulting reaction mixture by heating resulted in the decomposition of the azide group on the cross-linker, which was critical for the coupling step. Efforts to overcome this problem were unsuccessful.

The aim of the study was to test whether or not menstruating women’s levels of haemoglobin changed after three weeks consumption of Blutsaft. Previous studies on nutrition supplements including iron have shown increased haemoglobin levels. On Blutsaft, however, there are no studies carried out and published. The participants in this pilot study were menstruating women, with haemoglobin levels between 105 and 125 g/l at the initial part of the study. Haemoglobin concentrations were measured by capillary blood samples before and after three weeks recommended daily consumption of Blutsaft. Four participants completed the study and the result showed an increase in haemoglobin concentration of between 7 and 17 g/l., with a median value at 16,75 g/l. Despite the few participants who completed the study a significant increase in haemoglobin concentration, after the consumption of Blutsaft, can be determined.

No description available.

No description available.

No description available.

A comparative phylogenetically independent contrast (PIC) analysis was employed to investigate the adaptive role of traits involved in hypoxia tolerance in sculpins, a group of closely related fish species that live in the nearshore marine environment. I demonstrated that there was a tight correlation between critical oxygen (O₂) tension (P-crit) and the distribution of species across an environmental gradient. Species of sculpins with the lowest P-crit inhabit the 0₂ variable intertidal zone, while species with higher P-crit inhabit the O₂ stable subtidal zone. Low P-crit values in sculpins were associated with enhanced O₂ extraction capacity, with three principal traits accounting for 83% of the variation in P-crit: low routine O₂ consumption rate (MO2 ), high mass specific gill surface area and high whole cell hemoglobin-oxygen (Hb-0₂) binding affinity. Variation in whole cell Hb-O₂ binding affinity was strongly correlated with the intrinsic affinity of Hb for O₂ and not to differences in the concentration of the allosteric Hb modulators ATP and GTP. When environmental O₂ dropped below a species' P-crit, some species of sculpins behaviorally responded to the severe hypoxia by performing aquatic surface respiration (ASR) and aerial emergence. Although intertidal sculpins consistently performed these behaviors, the clustering of these species into a single phylogenetic Glade did not allow us to draw conclusions regarding the relationship between ASR, aerial emergence and P-crit using PIC analysis. Three species of sculpins, which were chosen because of their low, medium and high P-crit values, exhibited dramatically varied mortality rates when exposed to severe hypoxia equivalent to 40% of their respective P-crit. Although ATP turnover rates were similar between the three species in the initial two hours of hypoxia exposure, the differences in the ability of the three species to survive severe hypoxia appeared to be associated with the concentration of on-board liver glycogen and the degree of liver glycogen depletion. However, when liver glycogen was assessed in twelve species of sculpins at normoxia and compared with P-crit, there was nosignificant PIC correlation between P-crit and liver glycogen. Overall, I have shown that there is a clear relationship between P-crit and the distribution of sculpins along the nearshore environment and that this is primarily related to differences in O₂ extraction capacity. When O₂ tensions are well below their P-crit, there are dramatic differences in behavioral, physiological and biochemical responses among these species of sculpins.

Hb E (α₂β₂^{26 glu→lys}) is one of tne most common haemoglobin variants, found in an estimated 30 million people in South-East Asia. Homozygotes for Hb E are only mildly anaemic but compound heterozygotes with β thalassaemia have a severe clinical disorder which is the commonest form of symptomatic thalassaemia in S.E. Asia. The reasons for the high frequency of the S E gene and the severity of its interaction with β thalassaemia have never been adequately explained. We have studied eight Hb E homozygotes and nine heterozygotes all of S.E. Asian origin. In peripheral blood reticulocytes of homozygotes there was marked deficit of β^E chain synthesis relative to α chain synthesis (α/β^E ratio 2.0-3.3) and this was also observed to a lesser degree in the heterozygotes (1.23-2.19). There was no evidence that this was due to rapid destruction of the newly synthesised β^E chains, nor that Hb E was preferentially destroyed during the lifespan of the red cell. Measurement of the ratios of α/β globin mRNA in the reticulocytes of these subjects showed E a deficit of 3 mRNA consistent with the decreased β^E chain synthesis in these cells. Assessment of α/β mRNA ratios in bone marrow samples suggested normal transcription of β^E mRNA and transport out of the nucleus but that once in the cytoplasm the β^E mRNA was relatively unstable. The nature of the mRNA defect is unknown and could result either from the base substitution responsible for the amino acid change or from a second independent mutation in this gene. Thus the β^E gene acts as a mild β thalassaemia gene, the defect acting at a pretranslational level. This explains why on interaction with β thalassaemia there is marked deficit of β chain production leading to a disorder of clinical importance.

A comparative phylogenetically independent contrast (PIC) analysis was employed to investigate the adaptive role of traits involved in hypoxia tolerance in sculpins, a group of closely related fish species that live in the nearshore marine environment. I demonstrated that there was a tight correlation between critical oxygen (O₂) tension (P-crit) and the distribution of species across an environmental gradient. Species of sculpins with the lowest P-crit inhabit the 0₂ variable intertidal zone, while species with higher P-crit inhabit the O₂ stable subtidal zone. Low P-crit values in sculpins were associated with enhanced O₂ extraction capacity, with three principal traits accounting for 83% of the variation in P-crit: low routine O₂ consumption rate (MO2 ), high mass specific gill surface area and high whole cell hemoglobin-oxygen (Hb-0₂) binding affinity. Variation in whole cell Hb-O₂ binding affinity was strongly correlated with the intrinsic affinity of Hb for O₂ and not to differences in the concentration of the allosteric Hb modulators ATP and GTP. When environmental O₂ dropped below a species' P-crit, some species of sculpins behaviorally responded to the severe hypoxia by performing aquatic surface respiration (ASR) and aerial emergence. Although intertidal sculpins consistently performed these behaviors, the clustering of these species into a single phylogenetic Glade did not allow us to draw conclusions regarding the relationship between ASR, aerial emergence and P-crit using PIC analysis. Three species of sculpins, which were chosen because of their low, medium and high P-crit values, exhibited dramatically varied mortality rates when exposed to severe hypoxia equivalent to 40% of their respective P-crit. Although ATP turnover rates were similar between the three species in the initial two hours of hypoxia exposure, the differences in the ability of the three species to survive severe hypoxia appeared to be associated with the concentration of on-board liver glycogen and the degree of liver glycogen depletion. However, when liver glycogen was assessed in twelve species of sculpins at normoxia and compared with P-crit, there was nosignificant PIC correlation between P-crit and liver glycogen. Overall, I have shown that there is a clear relationship between P-crit and the distribution of sculpins along the nearshore environment and that this is primarily related to differences in O₂ extraction capacity. When O₂ tensions are well below their P-crit, there are dramatic differences in behavioral, physiological and biochemical responses among these species of sculpins.

Thesis ( Ph.D) -- McMaster University, 2001. / Includes bibliographical references. Also available via World Wide Web.