Professor Harrison Weisinger | The University of Western Australia (original) (raw)
Papers by Professor Harrison Weisinger
Investigative ophthalmology & visual science, 1999
To investigate the nature and reversibility of biochemical and functional changes in the retina e... more To investigate the nature and reversibility of biochemical and functional changes in the retina encountered over a single generation of dietary n-3 polyunsaturated fatty acid deficiency in guinea pigs. Dunkin-Hartley guinea pigs were fed for 16 weeks after weaning with diets supplemented with safflower seed oil (n-3 deficient) or canola oil (n-3 sufficient, control). A number of deficient animals were repleted at 6 weeks with canola oil for 5 or 10 weeks, or at 11 weeks for 5 weeks. Electroretinograms (0.8 and 4.3 log scot td x sec) were collected at 6, 11, and 16 weeks after weaning. Conventional waveforms (a- and b-waves), oscillatory potentials, and receptoral and postreceptoral subcomponents (PIII and PII, respectively) were evaluated. Cone pathway function was assessed with 30-Hz flicker at the brighter intensity. Retinal phospholipid fatty acids were measured by capillary gas-liquid chromatography. Electroretinographic amplitudes showed statistically significant losses in b- a...
Fatty Acids
The precursors of both n-6 and n-3 polyunsaturated fatty acids (PUFAs), linoleic acid and α-linol... more The precursors of both n-6 and n-3 polyunsaturated fatty acids (PUFAs), linoleic acid and α-linolenic acid, respectively, are essential for mammals as they are required for normal physiological function and cannot be synthesized de novo (Holman, 1968). They can only be accumulated by placental transfer or by dietary intake. Once accretion of these fatty acids has occurred, metabolic, conservation and recycling pathways sustain them (Bazan et al., 1994) Unlike mammals, plants can synthesize these precursor PUFAs (linoleic and α-linolenic acids) so they are found in abundance in the chloroplast membranes of plants, in certain vegetable oils, and in the tissues of plant-eating animals (Nettleton, 1991). The best sources of α-linolenic acid are vegetable oils, such as perilla (Yoshida et al., 1993) rapeseed (canola), linseed, walnut, and soybean (Nettleton, 1991). They are also abundant in shellfish, fish, and fish products and can be found in low amounts in green, leafy vegetables and baked beans (Nettleton, 1991; Sinclair, 1993).
Optometry and Vision Science, 1995
Annals of Nutrition and Metabolism, 1996
Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA)... more Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA), in the retina of all mammals, their role in vision remains unclear. However, the widely accepted notion that DHA is universally important in the retinal function was questioned in an earlier study (see text) involving guinea pigs, completely depleted of retinal DHA. The purpose of this study was to replicate this mammalian model of such deficiency and to determine any abnormalities in the electroretinogram. Guinea pigs were raised through three generations on 1 of 2 semipurified diets, containing different amounts of n-3 fatty acids, as determined by the supplementary oil which was the sole source of lipid in each diet. The added oils were safflower oil (n-6/n-3 = 72.0) or canola oil (n-6/n-3 = 2.5). Comprehensive electroretinographic assessment was conducted on guinea pigs, aged 6-9 weeks (safflower n = 13, canola n = 12), and retinae were extracted and the phospholipid fatty acid profile analyzed. Phospholipid fatty acid analysis revealed significant DHA deficiency (p < 0.001) in guinea pigs reared on the safflower oil diet (retinal DHA 2.5%) as compared with the canola oil group (retinal DHA 21.0%). Analysis of the electroretinogram showed significant reductions (p < 0.003) in both peak-to-peak and a-waves of safflower oil fed animals.
Appetite, Dec 1, 2010
v-3 fatty acid deficiency Fos Fluid intake Sodium balance
British Journal of Nutrition, 2012
Nature Medicine, Mar 1, 2001
Asia Pacific Journal of Clinical Nutrition, 2005
Proceedings of the 2013 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining - ASONAM '13, 2013
ABSTRACT Optometry is an essential health care profession that has existed for many centuries and... more ABSTRACT Optometry is an essential health care profession that has existed for many centuries and is still evolving. However, the training approaches for optometrists are not yet on par with the latest technological evolution. The traditional supervisor-student training mode could not provide good immersion and repeatability, while most existing vision-based computer-assisted simulations provide even worse immersion on screens. In this paper, we propose an effective system for optometry training simulation with two major components: augmented reality and haptics. These components are integrated with the actual slit lamp and are able to greatly enhance the immersion for typical optometry training tasks such as foreign body removal. Medical doctors are also involved in suggesting configurations and validating visual and haptic rendering results. Preliminary user studies show very positive feedbacks from optometry students.
Sarcoidosis is a granulomatous disorder of uncertain aetiology that can affect almost any organ. ... more Sarcoidosis is a granulomatous disorder of uncertain aetiology that can affect almost any organ. Anterior uveitis is a feature of the condition in about 30 per cent of those affected. We describe a patient with sarcoidosis presenting with anterior uveitis and describe a diagnostic approach. Sarcoidosis is a condition that must be considered in patients presenting with symp- tomatic uveitis,
Network Modeling Analysis in Health Informatics and Bioinformatics, 2014
ABSTRACT Optometry is an essential health care profession that has existed for many centuries and... more ABSTRACT Optometry is an essential health care profession that has existed for many centuries and is still evolving. However, the training approaches for optometrists are not yet on par with the latest technological evolution. The traditional supervisor–student training mode could not provide good immersion and repeatability, while most existing vision-based computer-assisted simulations provide even worse immersion on screens. In this paper, we propose an effective system for optometry training simulation with two setups: augmented reality based and absolution measurement transducer based. Both setups are seamlessly integrated with haptic devices as well as with the actual slit lamp. They are able to greatly enhance the immersion for typical optometry training tasks such as foreign body removal. Medical doctors and optometry students are also actively involved in suggesting configurations and validating visual and haptic rendering results on these setups. Preliminary user studies show very positive feedbacks from the optometry students.
2012 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2012
ABSTRACT Training of optometrists is traditionally achieved under close supervision of peers and ... more ABSTRACT Training of optometrists is traditionally achieved under close supervision of peers and superiors. With the rapid advancement in technology, medical procedures are performed more efficiently and effectively, resulting in faster recovery times and less trauma to the patient. However, application of this technology has made it difficult to effectively demonstrate and teach these manual skills as the education is now a combination of not only the medical procedure but also the use of the technology. In this paper we propose to increase the training capabilities of optometry students through haptically-enabled single-point and multi-point training tools as well as augmented reality techniques. Haptics technology allows a human to touch and feel virtual computer models as though they are real. Through physical connection to the operator, haptic devices are considered to be personal robots that are capable of improving the human-computer interaction with a virtual environment. These devices have played an increasing role in developing expertise, reducing instances of medical error and reducing training costs. A haptically-enabled virtual training environment, integrated with an optometry slit lamp instrument can be used to teach cognitive and manual skills while the system tracks the performance of each individual. These interactions would ideally replicate every aspect of the real procedure, consequently preparing the trainee for every possible scenario, without risking the health of a real patient.
International journal of obesity (2005), 2008
There is emerging evidence that angiotensin stimulates adipocyte differentiation and lipogenesis.... more There is emerging evidence that angiotensin stimulates adipocyte differentiation and lipogenesis. This study tested the hypothesis that inhibition of angiotensin II by treatment with an angiotensin-converting enzyme inhibitor, perindopril, would reduce fat mass in rats. After a 12-day baseline, rats were divided into two groups: one was untreated and the other received perindopril (1.2 mg kg(-1) per day) in drinking water for 26 days. In total, 16 male Sprague-Dawley rats aged 10 weeks at the start of the study. Plasma leptin was measured in samples collected at baseline, half-way through and at the end of treatment. Body weight, food and water intake were measured daily throughout the experiment. Body fat mass, bone and lean mass were determined by dual energy X-ray absorptiometry (DEXA) at the end of the treatment period. Daily food intake was the same in both groups throughout the study. By the end of treatment, animals receiving perindopril showed a modest reduction in weight ga...
Handbook of Essential Fatty Acid Biology, 1997
Lipids in Infant Nutrition, 1998
![Research paper thumbnail of Orally administered [14C]DPA and [14C]DHA are metabolised differently to [14C]EPA in rats](https://attachments.academia-assets.com/53621888/thumbnails/1.jpg)
](British Journal of Nutrition, 2013
European Journal of Nutrition, 2013
Purpose Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic ac... more Purpose Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids and red blood cells (RBC) in humans, very little is known about docosapentaenoic acid (DPA, 22:5 n-3). The aim of this study was to investigate the uptake and incorporation of pure DPA and EPA into human plasma and RBC lipids.
Endocrinology, 2004
The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in... more The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in the stress response, have acute effects on arterial pressure. New evidence indicates that urocortin (UCN), the putative agonist for the CRF type 2 receptor, has selective cardiovascular actions. The responses to long-term infusions of these hormones, both peripherally and centrally, in conscious animals have not been studied. Knowledge of the long-term effects is important because they may differ considerably from their acute actions, and stress is frequently a chronic stimulus. The present experiments investigated the cardiovascular effects of CRF, UCN, and ACTH in conscious sheep. Infusions were made either into the lateral cerebral ventricles (i.c.v.) or i.v. over 4 d at 5 microg/h. UCN infused i.c.v. or i.v. caused a prolonged increase in heart rate (HR) (P < 0.01) and a small increase in mean arterial pressure (MAP) (P < 0.05). CRF infused i.c.v. or i.v. progressively increased MAP (P < 0.05) but had no effect on HR. Central administration of ACTH had no effect, whereas systemic infusion increased MAP and HR (P < 0.001). In conclusion, long-term administration of these three peptides associated with the stress response had prolonged, selective cardiovascular actions. The striking finding was the large and sustained increase in HR with i.c.v. and i.v. infusions of UCN. These responses are probably mediated by CRF type 2 receptors because they were not reproduced by infusions of CRF.
Appetite, 2010
v-3 fatty acid deficiency Fos Fluid intake Sodium balance
Annals of Nutrition and Metabolism, 1996
Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA)... more Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA), in the retina of all mammals, their role in vision remains unclear. However, the widely accepted notion that DHA is universally important in the retinal function was questioned in an earlier study (see text) involving guinea pigs, completely depleted of retinal DHA. The purpose of this study was to replicate this mammalian model of such deficiency and to determine any abnormalities in the electroretinogram. Guinea pigs were raised through three generations on 1 of 2 semipurified diets, containing different amounts of n-3 fatty acids, as determined by the supplementary oil which was the sole source of lipid in each diet. The added oils were safflower oil (n-6/n-3 = 72.0) or canola oil (n-6/n-3 = 2.5). Comprehensive electroretinographic assessment was conducted on guinea pigs, aged 6-9 weeks (safflower n = 13, canola n = 12), and retinae were extracted and the phospholipid fatty acid profile analyzed. Phospholipid fatty acid analysis revealed significant DHA deficiency (p < 0.001) in guinea pigs reared on the safflower oil diet (retinal DHA 2.5%) as compared with the canola oil group (retinal DHA 21.0%). Analysis of the electroretinogram showed significant reductions (p < 0.003) in both peak-to-peak and a-waves of safflower oil fed animals.
Investigative ophthalmology & visual science, 1999
To investigate the nature and reversibility of biochemical and functional changes in the retina e... more To investigate the nature and reversibility of biochemical and functional changes in the retina encountered over a single generation of dietary n-3 polyunsaturated fatty acid deficiency in guinea pigs. Dunkin-Hartley guinea pigs were fed for 16 weeks after weaning with diets supplemented with safflower seed oil (n-3 deficient) or canola oil (n-3 sufficient, control). A number of deficient animals were repleted at 6 weeks with canola oil for 5 or 10 weeks, or at 11 weeks for 5 weeks. Electroretinograms (0.8 and 4.3 log scot td x sec) were collected at 6, 11, and 16 weeks after weaning. Conventional waveforms (a- and b-waves), oscillatory potentials, and receptoral and postreceptoral subcomponents (PIII and PII, respectively) were evaluated. Cone pathway function was assessed with 30-Hz flicker at the brighter intensity. Retinal phospholipid fatty acids were measured by capillary gas-liquid chromatography. Electroretinographic amplitudes showed statistically significant losses in b- a...
Fatty Acids
The precursors of both n-6 and n-3 polyunsaturated fatty acids (PUFAs), linoleic acid and α-linol... more The precursors of both n-6 and n-3 polyunsaturated fatty acids (PUFAs), linoleic acid and α-linolenic acid, respectively, are essential for mammals as they are required for normal physiological function and cannot be synthesized de novo (Holman, 1968). They can only be accumulated by placental transfer or by dietary intake. Once accretion of these fatty acids has occurred, metabolic, conservation and recycling pathways sustain them (Bazan et al., 1994) Unlike mammals, plants can synthesize these precursor PUFAs (linoleic and α-linolenic acids) so they are found in abundance in the chloroplast membranes of plants, in certain vegetable oils, and in the tissues of plant-eating animals (Nettleton, 1991). The best sources of α-linolenic acid are vegetable oils, such as perilla (Yoshida et al., 1993) rapeseed (canola), linseed, walnut, and soybean (Nettleton, 1991). They are also abundant in shellfish, fish, and fish products and can be found in low amounts in green, leafy vegetables and baked beans (Nettleton, 1991; Sinclair, 1993).
Optometry and Vision Science, 1995
Annals of Nutrition and Metabolism, 1996
Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA)... more Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA), in the retina of all mammals, their role in vision remains unclear. However, the widely accepted notion that DHA is universally important in the retinal function was questioned in an earlier study (see text) involving guinea pigs, completely depleted of retinal DHA. The purpose of this study was to replicate this mammalian model of such deficiency and to determine any abnormalities in the electroretinogram. Guinea pigs were raised through three generations on 1 of 2 semipurified diets, containing different amounts of n-3 fatty acids, as determined by the supplementary oil which was the sole source of lipid in each diet. The added oils were safflower oil (n-6/n-3 = 72.0) or canola oil (n-6/n-3 = 2.5). Comprehensive electroretinographic assessment was conducted on guinea pigs, aged 6-9 weeks (safflower n = 13, canola n = 12), and retinae were extracted and the phospholipid fatty acid profile analyzed. Phospholipid fatty acid analysis revealed significant DHA deficiency (p < 0.001) in guinea pigs reared on the safflower oil diet (retinal DHA 2.5%) as compared with the canola oil group (retinal DHA 21.0%). Analysis of the electroretinogram showed significant reductions (p < 0.003) in both peak-to-peak and a-waves of safflower oil fed animals.
Appetite, Dec 1, 2010
v-3 fatty acid deficiency Fos Fluid intake Sodium balance
British Journal of Nutrition, 2012
Nature Medicine, Mar 1, 2001
Asia Pacific Journal of Clinical Nutrition, 2005
Proceedings of the 2013 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining - ASONAM '13, 2013
ABSTRACT Optometry is an essential health care profession that has existed for many centuries and... more ABSTRACT Optometry is an essential health care profession that has existed for many centuries and is still evolving. However, the training approaches for optometrists are not yet on par with the latest technological evolution. The traditional supervisor-student training mode could not provide good immersion and repeatability, while most existing vision-based computer-assisted simulations provide even worse immersion on screens. In this paper, we propose an effective system for optometry training simulation with two major components: augmented reality and haptics. These components are integrated with the actual slit lamp and are able to greatly enhance the immersion for typical optometry training tasks such as foreign body removal. Medical doctors are also involved in suggesting configurations and validating visual and haptic rendering results. Preliminary user studies show very positive feedbacks from optometry students.
Sarcoidosis is a granulomatous disorder of uncertain aetiology that can affect almost any organ. ... more Sarcoidosis is a granulomatous disorder of uncertain aetiology that can affect almost any organ. Anterior uveitis is a feature of the condition in about 30 per cent of those affected. We describe a patient with sarcoidosis presenting with anterior uveitis and describe a diagnostic approach. Sarcoidosis is a condition that must be considered in patients presenting with symp- tomatic uveitis,
Network Modeling Analysis in Health Informatics and Bioinformatics, 2014
ABSTRACT Optometry is an essential health care profession that has existed for many centuries and... more ABSTRACT Optometry is an essential health care profession that has existed for many centuries and is still evolving. However, the training approaches for optometrists are not yet on par with the latest technological evolution. The traditional supervisor–student training mode could not provide good immersion and repeatability, while most existing vision-based computer-assisted simulations provide even worse immersion on screens. In this paper, we propose an effective system for optometry training simulation with two setups: augmented reality based and absolution measurement transducer based. Both setups are seamlessly integrated with haptic devices as well as with the actual slit lamp. They are able to greatly enhance the immersion for typical optometry training tasks such as foreign body removal. Medical doctors and optometry students are also actively involved in suggesting configurations and validating visual and haptic rendering results on these setups. Preliminary user studies show very positive feedbacks from the optometry students.
2012 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2012
ABSTRACT Training of optometrists is traditionally achieved under close supervision of peers and ... more ABSTRACT Training of optometrists is traditionally achieved under close supervision of peers and superiors. With the rapid advancement in technology, medical procedures are performed more efficiently and effectively, resulting in faster recovery times and less trauma to the patient. However, application of this technology has made it difficult to effectively demonstrate and teach these manual skills as the education is now a combination of not only the medical procedure but also the use of the technology. In this paper we propose to increase the training capabilities of optometry students through haptically-enabled single-point and multi-point training tools as well as augmented reality techniques. Haptics technology allows a human to touch and feel virtual computer models as though they are real. Through physical connection to the operator, haptic devices are considered to be personal robots that are capable of improving the human-computer interaction with a virtual environment. These devices have played an increasing role in developing expertise, reducing instances of medical error and reducing training costs. A haptically-enabled virtual training environment, integrated with an optometry slit lamp instrument can be used to teach cognitive and manual skills while the system tracks the performance of each individual. These interactions would ideally replicate every aspect of the real procedure, consequently preparing the trainee for every possible scenario, without risking the health of a real patient.
International journal of obesity (2005), 2008
There is emerging evidence that angiotensin stimulates adipocyte differentiation and lipogenesis.... more There is emerging evidence that angiotensin stimulates adipocyte differentiation and lipogenesis. This study tested the hypothesis that inhibition of angiotensin II by treatment with an angiotensin-converting enzyme inhibitor, perindopril, would reduce fat mass in rats. After a 12-day baseline, rats were divided into two groups: one was untreated and the other received perindopril (1.2 mg kg(-1) per day) in drinking water for 26 days. In total, 16 male Sprague-Dawley rats aged 10 weeks at the start of the study. Plasma leptin was measured in samples collected at baseline, half-way through and at the end of treatment. Body weight, food and water intake were measured daily throughout the experiment. Body fat mass, bone and lean mass were determined by dual energy X-ray absorptiometry (DEXA) at the end of the treatment period. Daily food intake was the same in both groups throughout the study. By the end of treatment, animals receiving perindopril showed a modest reduction in weight ga...
Handbook of Essential Fatty Acid Biology, 1997
Lipids in Infant Nutrition, 1998
British Journal of Nutrition, 2013
European Journal of Nutrition, 2013
Purpose Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic ac... more Purpose Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids and red blood cells (RBC) in humans, very little is known about docosapentaenoic acid (DPA, 22:5 n-3). The aim of this study was to investigate the uptake and incorporation of pure DPA and EPA into human plasma and RBC lipids.
Endocrinology, 2004
The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in... more The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in the stress response, have acute effects on arterial pressure. New evidence indicates that urocortin (UCN), the putative agonist for the CRF type 2 receptor, has selective cardiovascular actions. The responses to long-term infusions of these hormones, both peripherally and centrally, in conscious animals have not been studied. Knowledge of the long-term effects is important because they may differ considerably from their acute actions, and stress is frequently a chronic stimulus. The present experiments investigated the cardiovascular effects of CRF, UCN, and ACTH in conscious sheep. Infusions were made either into the lateral cerebral ventricles (i.c.v.) or i.v. over 4 d at 5 microg/h. UCN infused i.c.v. or i.v. caused a prolonged increase in heart rate (HR) (P < 0.01) and a small increase in mean arterial pressure (MAP) (P < 0.05). CRF infused i.c.v. or i.v. progressively increased MAP (P < 0.05) but had no effect on HR. Central administration of ACTH had no effect, whereas systemic infusion increased MAP and HR (P < 0.001). In conclusion, long-term administration of these three peptides associated with the stress response had prolonged, selective cardiovascular actions. The striking finding was the large and sustained increase in HR with i.c.v. and i.v. infusions of UCN. These responses are probably mediated by CRF type 2 receptors because they were not reproduced by infusions of CRF.
Appetite, 2010
v-3 fatty acid deficiency Fos Fluid intake Sodium balance
Annals of Nutrition and Metabolism, 1996
Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA)... more Despite the abundance of n-3 polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA), in the retina of all mammals, their role in vision remains unclear. However, the widely accepted notion that DHA is universally important in the retinal function was questioned in an earlier study (see text) involving guinea pigs, completely depleted of retinal DHA. The purpose of this study was to replicate this mammalian model of such deficiency and to determine any abnormalities in the electroretinogram. Guinea pigs were raised through three generations on 1 of 2 semipurified diets, containing different amounts of n-3 fatty acids, as determined by the supplementary oil which was the sole source of lipid in each diet. The added oils were safflower oil (n-6/n-3 = 72.0) or canola oil (n-6/n-3 = 2.5). Comprehensive electroretinographic assessment was conducted on guinea pigs, aged 6-9 weeks (safflower n = 13, canola n = 12), and retinae were extracted and the phospholipid fatty acid profile analyzed. Phospholipid fatty acid analysis revealed significant DHA deficiency (p < 0.001) in guinea pigs reared on the safflower oil diet (retinal DHA 2.5%) as compared with the canola oil group (retinal DHA 21.0%). Analysis of the electroretinogram showed significant reductions (p < 0.003) in both peak-to-peak and a-waves of safflower oil fed animals.
This is a brief post on the non-pharmacological management of anxiety in general practice. It is... more This is a brief post on the non-pharmacological management of anxiety in general practice. It is not intended to represent itself as research, nor is it evidence-based. In time, it will be used as a brief teaching document for students on placement and patients.
Most importantly, it is a draft!