title: A whole cord model for the identification of mechanisms for the antivascular effects of DMXAA

authors: Moses, Kiriana Mihi

subjects: endothelial cells

abstract: Endothelial cells form the inner lining of a blood vessel and their structure and functional integrity are important in maintenance of the vessel wall and circulatory function.
These cells play key roles in immune and inflammatory reactions by regulating lymphocyte and leukocyte movement into tissues; they are also main targets for antivascular agents in cancer therapy.
Endothelial cell responses to different stimuli have been previously investigated using conventional approaches, 'HUVEC in vitro culture system'.
In this study an ex vivo perfusion model was constructed and utilized using whole human umbilical cords, in attempts to replicate a more accurate in vivo microenvironment.
Assessment of the proportion and duration of endothelial cell viability in the ex vivo model was undertaken using a  MTT 3, (4,5-dimethylthiazol-2-yl) 2, 5-diphenyl-tetrazolium bromide viability assay. A time baseline was successfully established for all experimental perfusions.
Endothelial cell immune response was assessed through intravenous perfusion of the endotoxin, Lipopolysaccharide (LPS). Gene expression profiles revealed a significant increase in expression levels of E-Selctin (E-Sel), Intracellular adhesion molecule (I-CAM) and Tissue Factor (TF) relative to the housekeeping gene Beta 2 Microglobulin. When LPS was administered in combination with Hypertonic Saline 
 

Solution (HSS), expression levels declined indicating HSS interferes with the activation pathway of LPS ultimately suppressing its effectiveness on endothelial cells.
HSS impact was also recognized from perfusion experiments on resting endothelial cells. All identified genes were suppressed by HSS apart from inducible nitric oxide synthase (iNOS).
As a potential target for antivascular agents, HUVEC were then stimulated with DMXAA and gene responses of Tumour Necrosis Factor-α (TNF-α) was analysed.
DMXAA demonstrates excellent antivascular acivity in experimental tumours, so tumour conditioned media (TCM) was administered intravenously through umbilical cord segments to replicate a tumour microenvironment prior to DMXAA addition.
When cells were stimulated with Tumour conditioned media then administered DMXAA, TNF-α expression was significantly upregulated; relative to the housekeeping gene Human Proteosome subunit Y, however, when the cells were exposed to tumour conditioned media in absence of DMXAA gene expression significantly decreased. Thus, the antitumour action of DMXAA is capable of inhibiting the gene response of TNF-α replicated in a tumour environment.

text: A whole cord model for the identification of mechanisms for the antivascular effects of DMXAA Endothelial cells form the inner lining of a blood vessel and their structure and functional integrity are important in maintenance of the vessel wall and circulatory function.
These cells play key roles in immune and inflammatory reactions by regulating lymphocyte and leukocyte movement into tissues; they are also main targets for antivascular agents in cancer therapy.
Endothelial cell responses to different stimuli have been previously investigated using conventional approaches, 'HUVEC in vitro culture system'.
In this study an ex vivo perfusion model was constructed and utilized using whole human umbilical cords, in attempts to replicate a more accurate in vivo microenvironment.
Assessment of the proportion and duration of endothelial cell viability in the ex vivo model was undertaken using a  MTT 3, (4,5-dimethylthiazol-2-yl) 2, 5-diphenyl-tetrazolium bromide viability assay. A time baseline was successfully established for all experimental perfusions.
Endothelial cell immune response was assessed through intravenous perfusion of the endotoxin, Lipopolysaccharide (LPS). Gene expression profiles revealed a significant increase in expression levels of E-Selctin (E-Sel), Intracellular adhesion molecule (I-CAM) and Tissue Factor (TF) relative to the housekeeping gene Beta 2 Microglobulin. When LPS was administered in combination with Hypertonic Saline 
 

Solution (HSS), expression levels declined indicating HSS interferes with the activation pathway of LPS ultimately suppressing its effectiveness on endothelial cells.
HSS impact was also recognized from perfusion experiments on resting endothelial cells. All identified genes were suppressed by HSS apart from inducible nitric oxide synthase (iNOS).
As a potential target for antivascular agents, HUVEC were then stimulated with DMXAA and gene responses of Tumour Necrosis Factor-α (TNF-α) was analysed.
DMXAA demonstrates excellent antivascular acivity in experimental tumours, so tumour conditioned media (TCM) was administered intravenously through umbilical cord segments to replicate a tumour microenvironment prior to DMXAA addition.
When cells were stimulated with Tumour conditioned media then administered DMXAA, TNF-α expression was significantly upregulated; relative to the housekeeping gene Human Proteosome subunit Y, however, when the cells were exposed to tumour conditioned media in absence of DMXAA gene expression significantly decreased. Thus, the antitumour action of DMXAA is capable of inhibiting the gene response of TNF-α replicated in a tumour environment.

year: 2007

title: An evaluation of behavioural evolution and environmental DNA to inform the management and monitoring of biological invasions

authors: Pyper, Nicola

subjects: adaptation

abstract: Invasive species are a global phenomenon and the rate of biological invasion is only increasing as human trade and transport, together with climate change, cause the rapid reorganisation of species distributions. The impacts of invasive species can be both severe and wide ranging, adversely affecting native ecosystems, human health, agriculture, and economies. Therefore, understanding how species become invasive and subsequently inflict damage on host environments is imperative. Additionally, once an incursion has occurred, its rapid detection and ongoing monitoring are essential for management measures to be effective. My thesis aimed to further a greater understanding of behavioural evolution in invasive species and advance the application of genetic tools to inform and enhance the prediction, monitoring, and management of invasion events. 

In the first analysis (Chapter 2), I reviewed the scientific literature reporting behavioural changes in the traits of invasive species when compared to the mean traits of conspecifics in the native range. In this research, I demonstrated that, while behavioural changes are widely reported across invasive taxa, our understanding of the possible mechanisms enabling these changes – plasticity and adaptive evolution – are poorly understood. In addition, research on the fundamental molecular and genetic processes that underlie measured phenotypic changes is in its infancy. Moving forward, I recommend that opportunities to study new or recent biological invasions should be rapidly exploited such that temporal studies can be used to identify patterns of change that occur during invasion. 

In Chapter 3, I investigated the application of environmental DNA (eDNA: genetic material released by organisms into the environment) – an increasingly popular biomonitoring method that has yet to be optimised for lacustrine environments – to the detection and monitoring of the invasive brown bullhead catfish (Ameiurus nebulosus). I sampled lakes across two regions of the North Island of New Zealand and compared the results from different field (filter pore sizes, fyke nets) and laboratory (eDNA assays) protocols. I found that species-specific assays (quantitative PCR and catfish-specific metabarcoding) had the highest rates of catfish detection and further showed that multi-species metabarcoding assays were correlated with catfish capture from fyke nets. This indicates that species-specific assays may be the most effective where detection is the primary goal, while multi-species assays hold some promise for producing semi-quantitative results. Therefore, I recommend the development of standardised, flexible, eDNA protocols that will ensure their sound application and interpretation. 

As species continue to move beyond their natural ranges, the need for a better mechanistic understanding of invasion, and for more effective detection and monitoring methods, is increasing. With technological advances and increasing availability of genomic data, more rapidly identifying new incursions and studying invasions in real time will lead to better understanding, monitoring, and management of invasive species.

text: An evaluation of behavioural evolution and environmental DNA to inform the management and monitoring of biological invasions Invasive species are a global phenomenon and the rate of biological invasion is only increasing as human trade and transport, together with climate change, cause the rapid reorganisation of species distributions. The impacts of invasive species can be both severe and wide ranging, adversely affecting native ecosystems, human health, agriculture, and economies. Therefore, understanding how species become invasive and subsequently inflict damage on host environments is imperative. Additionally, once an incursion has occurred, its rapid detection and ongoing monitoring are essential for management measures to be effective. My thesis aimed to further a greater understanding of behavioural evolution in invasive species and advance the application of genetic tools to inform and enhance the prediction, monitoring, and management of invasion events. 

In the first analysis (Chapter 2), I reviewed the scientific literature reporting behavioural changes in the traits of invasive species when compared to the mean traits of conspecifics in the native range. In this research, I demonstrated that, while behavioural changes are widely reported across invasive taxa, our understanding of the possible mechanisms enabling these changes – plasticity and adaptive evolution – are poorly understood. In addition, research on the fundamental molecular and genetic processes that underlie measured phenotypic changes is in its infancy. Moving forward, I recommend that opportunities to study new or recent biological invasions should be rapidly exploited such that temporal studies can be used to identify patterns of change that occur during invasion. 

In Chapter 3, I investigated the application of environmental DNA (eDNA: genetic material released by organisms into the environment) – an increasingly popular biomonitoring method that has yet to be optimised for lacustrine environments – to the detection and monitoring of the invasive brown bullhead catfish (Ameiurus nebulosus). I sampled lakes across two regions of the North Island of New Zealand and compared the results from different field (filter pore sizes, fyke nets) and laboratory (eDNA assays) protocols. I found that species-specific assays (quantitative PCR and catfish-specific metabarcoding) had the highest rates of catfish detection and further showed that multi-species metabarcoding assays were correlated with catfish capture from fyke nets. This indicates that species-specific assays may be the most effective where detection is the primary goal, while multi-species assays hold some promise for producing semi-quantitative results. Therefore, I recommend the development of standardised, flexible, eDNA protocols that will ensure their sound application and interpretation. 

As species continue to move beyond their natural ranges, the need for a better mechanistic understanding of invasion, and for more effective detection and monitoring methods, is increasing. With technological advances and increasing availability of genomic data, more rapidly identifying new incursions and studying invasions in real time will lead to better understanding, monitoring, and management of invasive species.

year: 2024

title: Rewi Mokena: youngest son of Mokena Hou

authors: Hart, Philip

abstract: The youngest child of Mokena Hou, Rewi Mokena moved from place to place when young, finally settling permanently at Te Aroha. Having received some education, he was fluent in English. Like the typical rangatira of the time, he acquired interests in several blocks of land, obtained income from these in the short term, but because of financial difficulties was brought before the court several times. 
His involvement in gold mining started in a small way in 1875. Five years later, he would assist Hone Werahiko to prospect Te Aroha – and to fend off inquisitive Pakeha. He invested in claims in all of the three areas where gold was found.
By the twentieth century, Rewi was the most important rangatira at Te Aroha, and had wider influence, assisting the King Movement to seek redress for lost land. From a young age he participated in Pakeha society, notably as a rugby player, and became a prominent Mormon. His complicated private life, including bigamy and a wife’s attempted suicide because of his adultery, did not lower his high standing in Maori society nor damage his popularity with Pakeha.

text: Rewi Mokena: youngest son of Mokena Hou The youngest child of Mokena Hou, Rewi Mokena moved from place to place when young, finally settling permanently at Te Aroha. Having received some education, he was fluent in English. Like the typical rangatira of the time, he acquired interests in several blocks of land, obtained income from these in the short term, but because of financial difficulties was brought before the court several times. 
His involvement in gold mining started in a small way in 1875. Five years later, he would assist Hone Werahiko to prospect Te Aroha – and to fend off inquisitive Pakeha. He invested in claims in all of the three areas where gold was found.
By the twentieth century, Rewi was the most important rangatira at Te Aroha, and had wider influence, assisting the King Movement to seek redress for lost land. From a young age he participated in Pakeha society, notably as a rugby player, and became a prominent Mormon. His complicated private life, including bigamy and a wife’s attempted suicide because of his adultery, did not lower his high standing in Maori society nor damage his popularity with Pakeha.

year: 2016