title: Metformin induced expression of Hsp60 in human THP-1 monocyte cells

authors: Tsuei, An-Chi

subjects: Metformin

abstract: Metformin is in widespread clinical use for the treatment of diabetes mellitus in patients. It has been shown to inhibit mitochondrial bioenergetic functions by inhibiting complex I of the electron transport chain. The expression of mitochondrial-specific molecular stress protein Hsp60 is a key consequence of mitochondrial impairment. Since this protein has important immune-modulatory properties, we have investigated the expression of Hsp60 in human THP-1 monocyte cells exposed to metformin. In this study, we demonstrate significant up-regulation of Hsp60 at both mRNA and protein levels when these cells were exposed to metformin at therapeutic dosage levels. Interestingly, there was also an increase in expression of CD14 mRNA in these cells. This suggested a possible modulation of the differentiation rates of the THP-1 cells during exposure to metformin. As monocyte differentiation marks a critical step in atherosclerosis, these observations suggest that long-term exposure to metformin could have important implications for the diabetic patient.

text: Metformin induced expression of Hsp60 in human THP-1 monocyte cells Metformin is in widespread clinical use for the treatment of diabetes mellitus in patients. It has been shown to inhibit mitochondrial bioenergetic functions by inhibiting complex I of the electron transport chain. The expression of mitochondrial-specific molecular stress protein Hsp60 is a key consequence of mitochondrial impairment. Since this protein has important immune-modulatory properties, we have investigated the expression of Hsp60 in human THP-1 monocyte cells exposed to metformin. In this study, we demonstrate significant up-regulation of Hsp60 at both mRNA and protein levels when these cells were exposed to metformin at therapeutic dosage levels. Interestingly, there was also an increase in expression of CD14 mRNA in these cells. This suggested a possible modulation of the differentiation rates of the THP-1 cells during exposure to metformin. As monocyte differentiation marks a critical step in atherosclerosis, these observations suggest that long-term exposure to metformin could have important implications for the diabetic patient.

year: 2011

title: In situ mixing of organic matter decreases hydraulic conductivity of denitrification walls in sand aquifers

authors: Barkle, Gregory F.

abstract: In a previous study, a denitrification wall was constructed in a sand aquifer using sawdust as the carbon substrate. Ground water bypassed around this sawdust wall due to reduced hydraulic conductivity. We investigated potential reasons for this by testing two new walls and conducting laboratory studies. The first wall was constructed by mixing aquifer material in situ without substrate addition to investigate the effects of the construction technique (mixed wall). A second, biochip wall, was constructed using coarse wood chips to determine the effect of size of the particles in the amendment on hydraulic conductivity. The aquifer hydraulic conductivity was 35.4 m/d, while in the mixed wall it was 2.8 m/d and in the biochip wall 3.4 m/d. This indicated that the mixing of the aquifer sands below the water table allowed the particles to re-sort themselves into a matrix with a significantly lower hydraulic conductivity than the process that originally formed the aquifer. The addition of a coarser substrate in the biochip wall significantly increased total porosity and decreased bulk density, but hydraulic conductivity remained low compared to the aquifer. Laboratory cores of aquifer sand mixed under dry and wet conditions mimicked the reduction in hydraulic conductivity observed in the field within the mixed wall. The addition of sawdust to the laboratory cores resulted in a significantly higher hydraulic conductivity when mixed dry compared to cores mixed wet. This reduction in the hydraulic conductivity of the sand/sawdust cores mixed under saturated conditions repeated what occurred in the field in the original sawdust wall. This indicated that laboratory investigations can be a useful tool to highlight potential reductions in field hydraulic conductivities that may occur when differing materials are mixed under field conditions.

text: In situ mixing of organic matter decreases hydraulic conductivity of denitrification walls in sand aquifers In a previous study, a denitrification wall was constructed in a sand aquifer using sawdust as the carbon substrate. Ground water bypassed around this sawdust wall due to reduced hydraulic conductivity. We investigated potential reasons for this by testing two new walls and conducting laboratory studies. The first wall was constructed by mixing aquifer material in situ without substrate addition to investigate the effects of the construction technique (mixed wall). A second, biochip wall, was constructed using coarse wood chips to determine the effect of size of the particles in the amendment on hydraulic conductivity. The aquifer hydraulic conductivity was 35.4 m/d, while in the mixed wall it was 2.8 m/d and in the biochip wall 3.4 m/d. This indicated that the mixing of the aquifer sands below the water table allowed the particles to re-sort themselves into a matrix with a significantly lower hydraulic conductivity than the process that originally formed the aquifer. The addition of a coarser substrate in the biochip wall significantly increased total porosity and decreased bulk density, but hydraulic conductivity remained low compared to the aquifer. Laboratory cores of aquifer sand mixed under dry and wet conditions mimicked the reduction in hydraulic conductivity observed in the field within the mixed wall. The addition of sawdust to the laboratory cores resulted in a significantly higher hydraulic conductivity when mixed dry compared to cores mixed wet. This reduction in the hydraulic conductivity of the sand/sawdust cores mixed under saturated conditions repeated what occurred in the field in the original sawdust wall. This indicated that laboratory investigations can be a useful tool to highlight potential reductions in field hydraulic conductivities that may occur when differing materials are mixed under field conditions.

year: 2008

title: Hauora and physical education in New Zealand: perspectives of Māori and Pasifika

authors: Fitzpatrick, Katie

subjects: physical education

abstract: Discussion surrounding the concept of Hauora (Durie, 1994) in the document Health and Physical Education in the New Zealand Curriculum (Ministry of Education, 1999) has been controversial. Some writers have praised or justified its inclusion (Culpan, 1996/1997; Tasker, 1996/1997; Tinning, MacDonald, Wright & Hickey, 2001), while others accuse the writers of tokenism and misappropriation of indigenous knowledge (Hokowhitu, 2004; Salter, 2000). While existing at a political level, these debates have generally ignored student responses to and interactions with Hauora. Thus, this article intervenes in the existing debate and makes the case for the inclusion of student perspectives. My claims are made on the basis of a study into the perspectives of Māori and Pasifika students of physical education in New Zealand. The experiences of these students are related to the theory of hybridity (Besley, 2002; Bhabha, 1994), which suggests that young people actively negotiate and make critical decisions about what they think is relevant to them. I argue that the debate surrounding the concept of Hauora needs to include students' perspectives and consideration of the agency of young people in interactions with curriculum concepts.

text: Hauora and physical education in New Zealand: perspectives of Māori and Pasifika Discussion surrounding the concept of Hauora (Durie, 1994) in the document Health and Physical Education in the New Zealand Curriculum (Ministry of Education, 1999) has been controversial. Some writers have praised or justified its inclusion (Culpan, 1996/1997; Tasker, 1996/1997; Tinning, MacDonald, Wright & Hickey, 2001), while others accuse the writers of tokenism and misappropriation of indigenous knowledge (Hokowhitu, 2004; Salter, 2000). While existing at a political level, these debates have generally ignored student responses to and interactions with Hauora. Thus, this article intervenes in the existing debate and makes the case for the inclusion of student perspectives. My claims are made on the basis of a study into the perspectives of Māori and Pasifika students of physical education in New Zealand. The experiences of these students are related to the theory of hybridity (Besley, 2002; Bhabha, 1994), which suggests that young people actively negotiate and make critical decisions about what they think is relevant to them. I argue that the debate surrounding the concept of Hauora needs to include students' perspectives and consideration of the agency of young people in interactions with curriculum concepts.

year: 2005