The use of reclaimed wastewater for irrigation of horticultural crops is commonplace in many part... more The use of reclaimed wastewater for irrigation of horticultural crops is commonplace in many parts of the world and is likely to increase. Concerns about risks to human health arising from such practice, especially with respect to infection with microbial pathogens, are common. Several factors need to be considered when attempting to quantify the risk posed to a population, such as the concentration of pathogens in the source water, water treatment efficiency, the volume of water coming into contact with the crop, and the die-off rate of pathogens in the environment. Another factor, which has received relatively less attention, is the amount of food consumed. Plainly, higher consumption rates place one at greater risk of becoming infected. The amount of vegetables consumed is known to vary among ethic groups. We use Quantitative Microbial Risk Assessment Modelling (QMRA) to see if certain ethnic groups are exposed to higher risks by virtue of their consumption behaviour. The results suggest that despite the disparities in consumption rates by different ethnic groups they generally all faced comparable levels of risks. We conclude by suggesting that QMRA should be used to assess the relative levels of risk faced by groups based on divisions other than ethnicity, such as those with compromised immune systems.
... These data will be used to estimate the phytochemical and antioxidant intake of the ... of th... more ... These data will be used to estimate the phytochemical and antioxidant intake of the ... of the sample extract (drawn from the pooled extracts in the method extraction described above ... Trolox equivalentantioxidant capacity of sample was calculated based on the inhibition exerted by ...
Wseas Transactions on Environment and Development, 2006
Wastewater reuse is being widely promulgated to help address the global freshwater resource crisi... more Wastewater reuse is being widely promulgated to help address the global freshwater resource crisis. It can assist in reducing extraction of freshwater from the environment, and reuse of wastewater lessens the need for environmental discharge, which is clearly beneficial to receiving waters. But the practice itself also has the potential to be detrimental to natural and human environments: soil structure can become degraded, aquifers may be polluted, and human health may be threatened. The challenge facing natural resource managers is to identify the potential benefits and risks, and to achieve an appropriate balance. This paper describes environmental benefits and threats concomitant with the reuse of wastewater. We frequently draw upon examples from China and Australia-two countries that face particularly daunting water resource challenges-but the principles can be extended far beyond these geographical bounds and are applicable to many parts of the world.
Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds take... more Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds taken at weeks 4, 8, 20 and 30 were assayed for antibody titre by both an enzyme immunoassay (EIA) using a newly-described urease enzyme/substrate system and by bioassay in mice. There was a very good correlation between the two assay systems and, with the exception of the week 4 Bleeds, the relationship was the same at all stages of hyperimmunization regardless of titre, adjuvant, or whether toxin or toxoid was used as immunogen or for coating the plates. The results establish that the EIA can replace the bioassay for the determination of tetanus antitoxin in ovine sera.
The development of urease (E.C.3.5.1.5) as a label for enzyme immunoassay (EIA) procedures is des... more The development of urease (E.C.3.5.1.5) as a label for enzyme immunoassay (EIA) procedures is described and the use of such conjugates illustrated with examples. Urease catalyzes the hydrolysis of urea to carbon dioxide and ammonia. The production of ammonia may be detected readily by a pH shift which we have found best indicated by the vivid colour change (yellow to purple) of bromocresol purple incorporated in the substrate solution. This enzyme-substrate system offers a number of important advantages. The substrate in aqueous solution is stable, titration end points are sharp and readily visible and the enzyme is not inhibited by sodium azide. Thus, test reagents may be prepared with this preservative and stored ready to use. Urease of high specific activity is commercially available and because it does not occur in mammalian tissues, it is suitable for use in EIA tests to detect cell-associated antigens and their antibodies. Finally, the enzyme reaction may be stopped by the addition of organomercurial preservatives, thus allowing storage of developed tests for later examination.
Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica s... more Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica serovar Sofia persisted on cos lettuce in the greenhouse. Initial mean counts of the Salmonella on the injured and uninjured cos lettuce were on the order of 6 log CFU/g. After 3 days, the mean count decreased to 4.8 log CFU/g on the injured plants compared with the significantly (P < 0.05) smaller count of 3.4 log CFU/g on the uninjured plants. By the end of the 3-week experiment, the count from the injured plants was 2.9 log CFU/g compared with a count of below the level of detection from the uninjured plants. A similar pattern of bacterial persistence was observed on injured versus uninjured plants by using Listeria innocua on cos lettuce and S. enterica serovar Sofia on chive. The findings reaffirm earlier results with Escherichia coli and increase the impetus to avoid shoot injury during the production of cos lettuce and chive, if bacteria of food safety concern are present.
A tandemly repeated 1,046-base-pair (bp) ClaI DNA fragment from Bordetella pertussis was cloned i... more A tandemly repeated 1,046-base-pair (bp) ClaI DNA fragment from Bordetella pertussis was cloned into Escherichia coli by using the vector pUC19. This fragment, when isolated, hybridized strongly to DNA from all 100 clinical isolates of B. pertussis tested. It was shown to have homology to single-copy sequences in Bordetella bronchiseptica but not Bordetella parapertussis and did not hybridize to lysate blots of a wide range of other bacteria, including members of the closely related genera Pasteurella, Alcaligenes, and Haemophilus. The 1,046-bp fragment was sequenced, and complementary synthetic oligonucleotides flanking a 153-bp region within the repeated element were used as primers for specific amplification of this region using the polymerase chain reaction (PCR). This procedure was then applied to the rapid (5-h) detection of B. pertussis in nasopharyngeal secretions collected from 332 children with suspected pertussis. The test yielded positive results in a total of 98 samples, compared with 66 for culture and 33 for direct immunofluorescence (IF). All of the IF-positive samples were PCR positive, as were 63 of the samples from which B. pertussis was eventually cultured. Two hundred thirty-one specimens which were negative by IF and culture were also negative in the PCR assay. However, 33 culture-and IF-negative specimens were positive by PCR assay. Several of these specimens were collected from close contacts of culture-proven pertussis patients, were follow-up specimens from such patients, or were from patients with serological evidence of pertussis and therefore may be truerather than false-positives.
The isotype-specific antibody responses of sheep immunised with keyhole limpet hemocyanin by a pe... more The isotype-specific antibody responses of sheep immunised with keyhole limpet hemocyanin by a peripheral route (intramuscular (i.m.) injection) were compared to those induced by immunisation via different mucosal routes: (1) intra-nasal spray; (2) rectal deposition with cholera toxin; (3) injection into the mucosa of the small intestine or rectum. Antigen-specific IgG1 antibodies were induced in the i.m., intra-intestinal and intra-rectal injection groups and in a proportion of the cholera toxin immunised sheep, but not in the intra-nasal immunisation group. IgA was the only antibody isotype detected in serum collected from the intra-nasal immunisation group. No significant differences in serum IgA levels were detected in any of the mucosal immunisation groups as compared to the i.m. injection group. In contrast, analysis of the in vitro antibody profiles secreted by circulating antibody-secreting cells (ASC) revealed significantly higher IgA responses in the supernatants from all ...
Further reproduction without permission is prohibited M: Food Microbiology & Safety JFS M: Food M... more Further reproduction without permission is prohibited M: Food Microbiology & Safety JFS M: Food Microbiology and Safety P P < 0.05) damage to the qual-< 0.05) damage to the qual-< 0.05) damage to the qual-< 0.05) damage to the qual-< 0.05) damage to the quality of Cos lettuce tissues. ity of Cos lettuce tissues. ity of Cos lettuce tissues. ity of Cos lettuce tissues. ity of Cos lettuce tissues.
The distribution of antigen-specific memory T cells in different lymph nodes of sheep was determi... more The distribution of antigen-specific memory T cells in different lymph nodes of sheep was determined using an antigen-specific in vitro proliferation assay. Lymph nodes were collected from sheep immunized simultaneously with avidin or ovalbumin in a peripheral tissue site (hind leg muscle) and keyhole limpet haemocyanin (KLH) in an intestinal tissue site (gut wall or colonic mucosa). The results showed a consistently high proliferative response in typical peripheral lymph nodes (popliteal and prescapular) and a low or negative response in gastrointestinal lymph nodes (abomasal and jejunal) while the response in other nodes was variable. The low proliferative response in the gastrointestinal lymph nodes was not due to the presence of suppressor CD8- lymphocytes and the proliferative response could not be raised to peripheral lymph nodes levels with the addition to cultures of IL-2 or mitomycin-C treated peripheral lymph node cells. The high proliferative response in the peripheral lymph nodes was not suppressed by the addition of mitomycin-C-treated gastric lymph node cells but was dramatically reduced by the addition of mAb against the IL-2-receptor or by depletion of CD4- T cells. The results suggest that antigen-specific proliferative memory T cells, which may be Th1-like memory cells, preferentially migrate to peripheral lymph nodes independent of their site of induction.
Lymphocyte populations, adhesion molecule and cytokine expression were determined in lymph nodes ... more Lymphocyte populations, adhesion molecule and cytokine expression were determined in lymph nodes draining peripheral (popliteal and prescapular) or mucosal (abomasal and jejunal) tissue sites using flow cytometry analysis, immunostaining and cytokine-specific reverse-transcriptionpolymerase chain reaction (RT-PCR). Similar proportions of lymphocyte subpopulations were present in all lymph nodes except for immunoglobulin A' (IgA+) B cells which were only present in significant numbers in the gastrointestinal lymph nodes. Peripheral lymph nodes contained a significantly higher number of CD4+ cells expressing L-selectin and 0l-integrin than mucosal lymph nodes while the ac4-integrin chain was expressed at similar levels in all lymph nodes. The peripheral node adressin recognized by the MECA 79 monoclonal antibody (mAb) was mainly expressed on peripheral lymph node vessels. RT-PCR analysis showed that interleukin (IL)-10 and IL-4 were preferentially induced in the gastrointestinal lymph nodes while IL-2 and interferon-'y (IFN-y) were induced in all lymph nodes after polyclonal stimulation. These results indicate that there are substantial differences in the cell populations and microenvironments of lymph nodes draining mucosal and peripheral tissue sites in adult sheep.
European Journal of Lipid Science and Technology, 2010
Palm oil is a rich source of vitamin E. The tocotrienol-rich fraction (TRF) extracted from palm o... more Palm oil is a rich source of vitamin E. The tocotrienol-rich fraction (TRF) extracted from palm oil contain 70% tocotrienols and 30% tocopherols. The effect of TRF supplementation on the immune modulation was evaluated in 6-wk-old female BALB/c mice immunized with ovalbumin (OVA) adjuvanted with alum. Mice in control and experimental groups were immunized subcutaneously (s.c.) on days 14 and 28 with a single dose of 50 mg OVA. The mice in the experimental group were orally gavaged daily with 1 mg of TRF from palm oil while those in the control group received carrier oil. The results show that mice in the experimental group produced significantly ( p<0.05) higher levels of interferon-gamma (IFN-g) compared to the control group. There was no significant ( p>0.05) difference in the levels of interleukin-4 (IL-4) produced between the control and experimental animals. Lymphocyte proliferation in response to mitogen or OVA stimulation was significantly ( p<0.05) higher in splenocytes derived from the TRF supplemented mice compared to control mice. These findings show that daily supplementation of palm TRF can induce a strong cell-mediated immune response, i.e., T-helper-1 (Th1) response, which would be beneficial to fight viral infections and cancer.
Foods derived from plants, such as fruits and vegetables, have been the backbone of human nutriti... more Foods derived from plants, such as fruits and vegetables, have been the backbone of human nutrition since the beginning of time. Hunting and fishing supplemented diets with protein-rich foods but nutrition was predominantly based on the availability of plant foods. The importance of various plant foods in the development of some civilizations and economies has been well documented: maize in the Americas, potatoes in parts of Europe after their introduction from the Americas, and wheat in Australia. Plant industries are still the backbone of cultures and economies in almost every corner of the world and production figures support the fact that plant industries are still regarded as the most important source of nutrition. Nutrition parameters found in plant foods vary between crops but there is a consensus that plant foods can supply most, if not all, of the essential components for human nutrition. These components were discovered slowly by trial and error during human history, a classic example was the prevention of scurvy in seafarers. When fresh fruit and vegetables were missing from their diet, they learned that products such as pickled cabbages and citrus, rich in vitamin C, could prevent the manifestation of this dehabilitating dietary disease. As early as the turn of the century scientists learned that diet not only affected nutrition but also had an effect on health and well-being. But it was not until 1933 that a direct relationship between consumption of fruit and vegetables and diseases such as cancer was shown. Fruit and vegetables not only have become the backbone of local agricultural markets but also play a major role in international trade. Competition for local and international markets is driving extensive research and development to produce new cultivars. Until recent times research has concentrated on producing new varieties that store longer, yield better, look better, taste better, suit local climates, display disease and pest resistance and suit processing technologies. A new wave of research is addressing the newly developing interest in heath-based foods. Molecular biologists, biochemists, botanists and medical researchers are linking in with plant breeding programmes to develop new varieties of fruit and vegetables that are tailor-made to produce higher levels of health-related phytochemicals. New phytochemical-enhanced products such as broccoli, tomato, oranges and berries are currently being evaluated for commercial exploitation. The present paper will discuss some of the products that are being produced, the driving forces behind their production, the phytochemicals targeted and the problems that must be addressed if this new approach in human nutrition and health is to be of benefit to consumers.
Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds take... more Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds taken at weeks 4, 8, 20 and 30 were assayed for antibody titre by both an enzyme immunoassay (EIA) using a newly-described urease enzyme/substrate system and by bioassay in mice. There was a very good correlation between the two assay systems and, with the exception of the week 4 Bleeds, the relationship was the same at all stages of hyperimmunization regardless of titre, adjuvant, or whether toxin or toxoid was used as immunogen or for coating the plates. The results establish that the EIA can replace the bioassay for the determination of tetanus antitoxin in ovine sera.
The use of reclaimed wastewater for irrigation of horticultural crops is commonplace in many part... more The use of reclaimed wastewater for irrigation of horticultural crops is commonplace in many parts of the world and is likely to increase. Concerns about risks to human health arising from such practice, especially with respect to infection with microbial pathogens, are common. Several factors need to be considered when attempting to quantify the risk posed to a population, such as the concentration of pathogens in the source water, water treatment efficiency, the volume of water coming into contact with the crop, and the die-off rate of pathogens in the environment. Another factor, which has received relatively less attention, is the amount of food consumed. Plainly, higher consumption rates place one at greater risk of becoming infected. The amount of vegetables consumed is known to vary among ethic groups. We use Quantitative Microbial Risk Assessment Modelling (QMRA) to see if certain ethnic groups are exposed to higher risks by virtue of their consumption behaviour. The results suggest that despite the disparities in consumption rates by different ethnic groups they generally all faced comparable levels of risks. We conclude by suggesting that QMRA should be used to assess the relative levels of risk faced by groups based on divisions other than ethnicity, such as those with compromised immune systems.
... These data will be used to estimate the phytochemical and antioxidant intake of the ... of th... more ... These data will be used to estimate the phytochemical and antioxidant intake of the ... of the sample extract (drawn from the pooled extracts in the method extraction described above ... Trolox equivalentantioxidant capacity of sample was calculated based on the inhibition exerted by ...
Wseas Transactions on Environment and Development, 2006
Wastewater reuse is being widely promulgated to help address the global freshwater resource crisi... more Wastewater reuse is being widely promulgated to help address the global freshwater resource crisis. It can assist in reducing extraction of freshwater from the environment, and reuse of wastewater lessens the need for environmental discharge, which is clearly beneficial to receiving waters. But the practice itself also has the potential to be detrimental to natural and human environments: soil structure can become degraded, aquifers may be polluted, and human health may be threatened. The challenge facing natural resource managers is to identify the potential benefits and risks, and to achieve an appropriate balance. This paper describes environmental benefits and threats concomitant with the reuse of wastewater. We frequently draw upon examples from China and Australia-two countries that face particularly daunting water resource challenges-but the principles can be extended far beyond these geographical bounds and are applicable to many parts of the world.
Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds take... more Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds taken at weeks 4, 8, 20 and 30 were assayed for antibody titre by both an enzyme immunoassay (EIA) using a newly-described urease enzyme/substrate system and by bioassay in mice. There was a very good correlation between the two assay systems and, with the exception of the week 4 Bleeds, the relationship was the same at all stages of hyperimmunization regardless of titre, adjuvant, or whether toxin or toxoid was used as immunogen or for coating the plates. The results establish that the EIA can replace the bioassay for the determination of tetanus antitoxin in ovine sera.
The development of urease (E.C.3.5.1.5) as a label for enzyme immunoassay (EIA) procedures is des... more The development of urease (E.C.3.5.1.5) as a label for enzyme immunoassay (EIA) procedures is described and the use of such conjugates illustrated with examples. Urease catalyzes the hydrolysis of urea to carbon dioxide and ammonia. The production of ammonia may be detected readily by a pH shift which we have found best indicated by the vivid colour change (yellow to purple) of bromocresol purple incorporated in the substrate solution. This enzyme-substrate system offers a number of important advantages. The substrate in aqueous solution is stable, titration end points are sharp and readily visible and the enzyme is not inhibited by sodium azide. Thus, test reagents may be prepared with this preservative and stored ready to use. Urease of high specific activity is commercially available and because it does not occur in mammalian tissues, it is suitable for use in EIA tests to detect cell-associated antigens and their antibodies. Finally, the enzyme reaction may be stopped by the addition of organomercurial preservatives, thus allowing storage of developed tests for later examination.
Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica s... more Minor shoot injury significantly (P < 0.05) increased the level at which Salmonella enterica serovar Sofia persisted on cos lettuce in the greenhouse. Initial mean counts of the Salmonella on the injured and uninjured cos lettuce were on the order of 6 log CFU/g. After 3 days, the mean count decreased to 4.8 log CFU/g on the injured plants compared with the significantly (P < 0.05) smaller count of 3.4 log CFU/g on the uninjured plants. By the end of the 3-week experiment, the count from the injured plants was 2.9 log CFU/g compared with a count of below the level of detection from the uninjured plants. A similar pattern of bacterial persistence was observed on injured versus uninjured plants by using Listeria innocua on cos lettuce and S. enterica serovar Sofia on chive. The findings reaffirm earlier results with Escherichia coli and increase the impetus to avoid shoot injury during the production of cos lettuce and chive, if bacteria of food safety concern are present.
A tandemly repeated 1,046-base-pair (bp) ClaI DNA fragment from Bordetella pertussis was cloned i... more A tandemly repeated 1,046-base-pair (bp) ClaI DNA fragment from Bordetella pertussis was cloned into Escherichia coli by using the vector pUC19. This fragment, when isolated, hybridized strongly to DNA from all 100 clinical isolates of B. pertussis tested. It was shown to have homology to single-copy sequences in Bordetella bronchiseptica but not Bordetella parapertussis and did not hybridize to lysate blots of a wide range of other bacteria, including members of the closely related genera Pasteurella, Alcaligenes, and Haemophilus. The 1,046-bp fragment was sequenced, and complementary synthetic oligonucleotides flanking a 153-bp region within the repeated element were used as primers for specific amplification of this region using the polymerase chain reaction (PCR). This procedure was then applied to the rapid (5-h) detection of B. pertussis in nasopharyngeal secretions collected from 332 children with suspected pertussis. The test yielded positive results in a total of 98 samples, compared with 66 for culture and 33 for direct immunofluorescence (IF). All of the IF-positive samples were PCR positive, as were 63 of the samples from which B. pertussis was eventually cultured. Two hundred thirty-one specimens which were negative by IF and culture were also negative in the PCR assay. However, 33 culture-and IF-negative specimens were positive by PCR assay. Several of these specimens were collected from close contacts of culture-proven pertussis patients, were follow-up specimens from such patients, or were from patients with serological evidence of pertussis and therefore may be truerather than false-positives.
The isotype-specific antibody responses of sheep immunised with keyhole limpet hemocyanin by a pe... more The isotype-specific antibody responses of sheep immunised with keyhole limpet hemocyanin by a peripheral route (intramuscular (i.m.) injection) were compared to those induced by immunisation via different mucosal routes: (1) intra-nasal spray; (2) rectal deposition with cholera toxin; (3) injection into the mucosa of the small intestine or rectum. Antigen-specific IgG1 antibodies were induced in the i.m., intra-intestinal and intra-rectal injection groups and in a proportion of the cholera toxin immunised sheep, but not in the intra-nasal immunisation group. IgA was the only antibody isotype detected in serum collected from the intra-nasal immunisation group. No significant differences in serum IgA levels were detected in any of the mucosal immunisation groups as compared to the i.m. injection group. In contrast, analysis of the in vitro antibody profiles secreted by circulating antibody-secreting cells (ASC) revealed significantly higher IgA responses in the supernatants from all ...
Further reproduction without permission is prohibited M: Food Microbiology & Safety JFS M: Food M... more Further reproduction without permission is prohibited M: Food Microbiology & Safety JFS M: Food Microbiology and Safety P P < 0.05) damage to the qual-< 0.05) damage to the qual-< 0.05) damage to the qual-< 0.05) damage to the qual-< 0.05) damage to the quality of Cos lettuce tissues. ity of Cos lettuce tissues. ity of Cos lettuce tissues. ity of Cos lettuce tissues. ity of Cos lettuce tissues.
The distribution of antigen-specific memory T cells in different lymph nodes of sheep was determi... more The distribution of antigen-specific memory T cells in different lymph nodes of sheep was determined using an antigen-specific in vitro proliferation assay. Lymph nodes were collected from sheep immunized simultaneously with avidin or ovalbumin in a peripheral tissue site (hind leg muscle) and keyhole limpet haemocyanin (KLH) in an intestinal tissue site (gut wall or colonic mucosa). The results showed a consistently high proliferative response in typical peripheral lymph nodes (popliteal and prescapular) and a low or negative response in gastrointestinal lymph nodes (abomasal and jejunal) while the response in other nodes was variable. The low proliferative response in the gastrointestinal lymph nodes was not due to the presence of suppressor CD8- lymphocytes and the proliferative response could not be raised to peripheral lymph nodes levels with the addition to cultures of IL-2 or mitomycin-C treated peripheral lymph node cells. The high proliferative response in the peripheral lymph nodes was not suppressed by the addition of mitomycin-C-treated gastric lymph node cells but was dramatically reduced by the addition of mAb against the IL-2-receptor or by depletion of CD4- T cells. The results suggest that antigen-specific proliferative memory T cells, which may be Th1-like memory cells, preferentially migrate to peripheral lymph nodes independent of their site of induction.
Lymphocyte populations, adhesion molecule and cytokine expression were determined in lymph nodes ... more Lymphocyte populations, adhesion molecule and cytokine expression were determined in lymph nodes draining peripheral (popliteal and prescapular) or mucosal (abomasal and jejunal) tissue sites using flow cytometry analysis, immunostaining and cytokine-specific reverse-transcriptionpolymerase chain reaction (RT-PCR). Similar proportions of lymphocyte subpopulations were present in all lymph nodes except for immunoglobulin A' (IgA+) B cells which were only present in significant numbers in the gastrointestinal lymph nodes. Peripheral lymph nodes contained a significantly higher number of CD4+ cells expressing L-selectin and 0l-integrin than mucosal lymph nodes while the ac4-integrin chain was expressed at similar levels in all lymph nodes. The peripheral node adressin recognized by the MECA 79 monoclonal antibody (mAb) was mainly expressed on peripheral lymph node vessels. RT-PCR analysis showed that interleukin (IL)-10 and IL-4 were preferentially induced in the gastrointestinal lymph nodes while IL-2 and interferon-'y (IFN-y) were induced in all lymph nodes after polyclonal stimulation. These results indicate that there are substantial differences in the cell populations and microenvironments of lymph nodes draining mucosal and peripheral tissue sites in adult sheep.
European Journal of Lipid Science and Technology, 2010
Palm oil is a rich source of vitamin E. The tocotrienol-rich fraction (TRF) extracted from palm o... more Palm oil is a rich source of vitamin E. The tocotrienol-rich fraction (TRF) extracted from palm oil contain 70% tocotrienols and 30% tocopherols. The effect of TRF supplementation on the immune modulation was evaluated in 6-wk-old female BALB/c mice immunized with ovalbumin (OVA) adjuvanted with alum. Mice in control and experimental groups were immunized subcutaneously (s.c.) on days 14 and 28 with a single dose of 50 mg OVA. The mice in the experimental group were orally gavaged daily with 1 mg of TRF from palm oil while those in the control group received carrier oil. The results show that mice in the experimental group produced significantly ( p<0.05) higher levels of interferon-gamma (IFN-g) compared to the control group. There was no significant ( p>0.05) difference in the levels of interleukin-4 (IL-4) produced between the control and experimental animals. Lymphocyte proliferation in response to mitogen or OVA stimulation was significantly ( p<0.05) higher in splenocytes derived from the TRF supplemented mice compared to control mice. These findings show that daily supplementation of palm TRF can induce a strong cell-mediated immune response, i.e., T-helper-1 (Th1) response, which would be beneficial to fight viral infections and cancer.
Foods derived from plants, such as fruits and vegetables, have been the backbone of human nutriti... more Foods derived from plants, such as fruits and vegetables, have been the backbone of human nutrition since the beginning of time. Hunting and fishing supplemented diets with protein-rich foods but nutrition was predominantly based on the availability of plant foods. The importance of various plant foods in the development of some civilizations and economies has been well documented: maize in the Americas, potatoes in parts of Europe after their introduction from the Americas, and wheat in Australia. Plant industries are still the backbone of cultures and economies in almost every corner of the world and production figures support the fact that plant industries are still regarded as the most important source of nutrition. Nutrition parameters found in plant foods vary between crops but there is a consensus that plant foods can supply most, if not all, of the essential components for human nutrition. These components were discovered slowly by trial and error during human history, a classic example was the prevention of scurvy in seafarers. When fresh fruit and vegetables were missing from their diet, they learned that products such as pickled cabbages and citrus, rich in vitamin C, could prevent the manifestation of this dehabilitating dietary disease. As early as the turn of the century scientists learned that diet not only affected nutrition but also had an effect on health and well-being. But it was not until 1933 that a direct relationship between consumption of fruit and vegetables and diseases such as cancer was shown. Fruit and vegetables not only have become the backbone of local agricultural markets but also play a major role in international trade. Competition for local and international markets is driving extensive research and development to produce new cultivars. Until recent times research has concentrated on producing new varieties that store longer, yield better, look better, taste better, suit local climates, display disease and pest resistance and suit processing technologies. A new wave of research is addressing the newly developing interest in heath-based foods. Molecular biologists, biochemists, botanists and medical researchers are linking in with plant breeding programmes to develop new varieties of fruit and vegetables that are tailor-made to produce higher levels of health-related phytochemicals. New phytochemical-enhanced products such as broccoli, tomato, oranges and berries are currently being evaluated for commercial exploitation. The present paper will discuss some of the products that are being produced, the driving forces behind their production, the phytochemicals targeted and the problems that must be addressed if this new approach in human nutrition and health is to be of benefit to consumers.
Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds take... more Antibodies to tetanus toxin were induced in sheep by hyperimmunization over 24 weeks. Bleeds taken at weeks 4, 8, 20 and 30 were assayed for antibody titre by both an enzyme immunoassay (EIA) using a newly-described urease enzyme/substrate system and by bioassay in mice. There was a very good correlation between the two assay systems and, with the exception of the week 4 Bleeds, the relationship was the same at all stages of hyperimmunization regardless of titre, adjuvant, or whether toxin or toxoid was used as immunogen or for coating the plates. The results establish that the EIA can replace the bioassay for the determination of tetanus antitoxin in ovine sera.
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Papers by Robert Premier