Strong acid + weak base > acidic salt + water various types of sugar derived from different sources treatment trichomoniasis buy generic careprost on line. Weak acid + strong base > alkaline salt + water sugars are called monosaccharides and include glucose (also known as dextrose) symptoms ketoacidosis purchase 3 ml careprost overnight delivery, fructose medicine 3 sixes buy careprost 3ml on-line, and galactose symptoms 9 days after embryo transfer buy careprost online from canada. The table or Examples: granulated sugar most customarily used as food is sucrose, 1. Chemically, different substances may also have a sweet taste, but are not classified as sugars. Some are used as lower-calorie Salts may have different solubilities; while some salts are food substitutes for sugar described as artificial sweeteners. In general, soluble salts are more ?damaging? to inorganic porous Studies in animals have suggested that chronic materials than the less soluble ones. Some experts have suggested the formula for sodium chloride, NaCl, indicates that equal that refined fructose is more damaging than refined glucose numbers of sodium and chlorine atoms combine to form the in terms of cardiovascular risk. Ionically, in the reaction of sodium with chlorine, each shown to be impaired by switching from a carbohydrate diet sodium atom loses an electron, becoming positively charged, including fiber to a high-carbohydrate diet . Switching from and each chlorine atom gains an electron, becoming negatively saturated fatty acids to carbohydrates with high glycemic charged; there are equal numbers of positively charged sodium index values shows a statistically-significant increase in the ions and negatively charged chloride ions in sodium chloride. Other studies have shown the ions in a solid salt are usually arranged in a definite that the risk of developing coronary heart disease is decreased crystalline structure, each positive ion being associated with a by adopting a diet high in polyunsaturated fatty acids but low fixed number of negative ions, and vice versa. Since a salt may react with a solvent to yield different ions associated with multiple measures known to increase than were present in the salt, a solution of a normal salt may be cardiovascular disease risk amongst adolescents as well as acidic or basic;. Studies are suggesting that the impact of refined and reacts with water to form a basic solution. The cardiac output is determined by the amount of blood in the heart at How to cite this article: Seriki A S. Arthur Guyton, a physiologist had postulated the theory of ?pressure natriuresis. It basically states that every patient But if the salt intake is not controlled over time, the with high blood pressure has a disorder of salt handling by the damage caused by the extra blood pressure may become so kidney. The appropriate response to increased blood pressure severe that the arteries burst or become completely clogged. A large body of If this happens, then the part of the heart that was receiving experimental data does indeed point to abnormally slow salt the blood no longer gets the oxygen and nutrients it needs and excretion by the kidney as an important component of human dies. And one of the best ways of doing this is keep the blood pressure down Cogent evidences indicate that salt intake is strongly related by eating less salt. The risk of cardiovascular disease On the brain: the raised blood pressure caused by increases throughout the range of blood pressure starting increased intake of salt may damage the arteries leading to the from a systolic blood pressure of 115mmHg [8,9] which 80% brain. At first, it may cause a slight reduction in the amount of of the adult population exceeds. However, lowering blood pressure may help to through the strokes and heart attacks it causes. This leads A high salt intake raises the amount of sodium in the to the death of part of the brain that was receiving the blood bloodstream and wrecks the delicate balance, reducing the as result of no longer getting oxygen and nutrients it needs ability of the kidneys to remove the water. The result is a stroke, where the body loses the retention which increases the pressure exerted by the blood ability to do the things that part of the brain used to control. Benefits: Common salt, also known as sodium chloride, Risks is a common ingredient used for seasoning purposes in our everyday foods. It is available in a range of diverse forms and On the arteries: the extra blood pressure caused by eating particle sizes, depending on the proposed use. To cope with the extra strain, the tiny muscles in the artery walls the salt/water ratio is critical for the metabolic rate of our become stronger and thicker. Salt facilitates sending signals in the nerves and muscles inside the arteries smaller and raises the blood pressure even and helps sustain the fluid content inside and outside the blood higher. Dietary salt exists in various forms: unrefined, refined (also known as table salt) and iodine-fortified salt. It offers a this cycle of increasing blood pressure (which occurs variety of health benefits. When this happens, the organs of the body that were proven that dietary salt determines the blood pressure of receiving the blood from the arteries become starved of the the body and has an impact on cardiovascular health, which oxygen and nutrients they need. On the heart: the raised blood pressure caused by eating too much salt may damage the arteries leading to the heart. So, Low Blood Pressure (hypotension) (reading below At first, it may cause a slight reduction in the amount of blood 90/60) can be treated by consuming more salt and hydrating reaching the heart. This will help boost the volume of blood in the arteries, chest when being active). Eventually, there may become as well as overheating in the surrounding environment, insulin and/or leptin resistant. The body fails to release heat properly the physiology behind it is that insulin stores magnesium, in order to attain its normal temperature. As a result, the but if its receptors are blunted and the cells grow resistant to body temperature becomes too high, which poses a threat to insulin, the body can?t store magnesium, so it passes out of the the major organs. Magnesium stored in the cells relaxes produces more sweat through the sweat glands, thereby losing muscles. Fructose also elevates uric acid, which Prevention of heat or sun stroke is always advisable by keeping drives up blood pressure by inhibiting the nitric oxide in the the body hydrated and consuming adequate amounts of salt in blood vessels (Uric acid is a byproduct of fructose metabolism; order to maintain the electrolyte balance. A person suffering in fact, fructose typically generates uric acid within minutes from heat stroke can be treated by offering water or fluids that of ingestion). Nitric oxide helps blood vessels maintain their elasticity, so Other health benefits of salts include: prevention of goiter nitric oxide suppression leads to increases in blood pressure. Eliminating excess sugar/fructose from diet electrolytes primarily entail magnesium, potassium, calcium, has incidentally been found to address all these three issues and sodium. Also, in diabetes, healthy levels of insulin are (insulin, leptin, and uric acid) in one fell swoop. When this optimum level increases the pressure exerted by the blood against blood of sodium falls, water enters into the cells to compensate. This results in an imbalance of water to salt ratio in the body, A large number of studies have been conducted which causing swelling in the cells because of excess water. The evidence is greater for the effect of salt on blood pressure than any other dietary Interaction, risk, and benefits: An emerging but and lifestyle factors including a low consumption of fruit and inconclusive body of evidence suggests that increased vegetables (i. Studies include animal studies in which rats were fed high doses of fructose, acute ingestion studies in which humans Two studies [17,18] both 4 weeks in duration, have were fed high doses of different sugars, and more recently, compared the effect of different salt intakes on blood pressure epidemiological studies, such as the Framingham Heart Study, [9,19] and 12g/day in one, [19,20] and 8g/day in the other). Nonetheless, results from studies in humans are inconsistent, Also, high intake of sugar raises insulin and leptin levels [14,15] and the chronic effects of a high intake of simple sugars in the blood, sometimes leading to insulin and/or leptin on blood pressure remain uncertain. Insulin stores magnesium, but if the cell receptors How sugar specifically interact with blood pressure are blunted and the cells grow resistant to insulin, the body (Hypertension): the fact is that an underlying cause of high can?t store magnesium, so it passes out of the body through blood pressure is often related to production of too much urination. If insulin and leptin in response to a high-carbohydrate and magnesium level is too low, the smooth muscle of the blood processed food diet. As insulin and leptin levels rise, it causes vessels will be unable to fully relax, and this constriction How to cite this article: Seriki A S. Am J Clin nitric oxide in the blood vessels Uric acid is a byproduct of Nutr 91(6): 1764-1768. Nutr Metab Experts have said that for every 4 gram of salt reduction Cardiovasc Dis 9(4 Suppl): 6-15. World Health Organisation (2002) Reducing risks, promoting healthy blood pressure by 7/4mmHg in individuals with high blood life. The relationships seen in these studies provide evidence pressure of adolescents with newly diagnosed essential hypertension: that the recommendation to reduce salt intake to 5-6g/day will a randomized trial. This can be achieved and the metabolic syndrome in middle-aged adults in the community. A good amount of that (about 75%) is already present in processed meals, breakfast cereals, and breads. Am J than one year should not consume more than 1 gram of salt, ClinNutr 37(5): 740-748. An insulin resistant patient with effects of sodium restriction in essential hypertension. This work is licensed under Creative Your next subm ission with Juniper Publishers Commons Attribution 4. A long held belief articulated here by Charles Darwin in the Expression of Emotion in Man and Animals (originally published in 1872) is that strong negative emotions directly in?
It provides a significant advantage in terms of hygiene compared to symptoms 5 weeks into pregnancy discount 3 ml careprost mastercard collection in the housing area chi royal treatment cheap 3 ml careprost fast delivery. Ejaculate bacterial contamination can be greatly reduced if this process is done correct treatment 7 discount 3 ml careprost otc. Boars entering the warm-up pen will be stimulated by smelling medicine logo careprost 3 ml mastercard, hearing, and watching another boar being collected;. Keep penis with tip above boars belly level (higher) to avoid preputial fluid from running down into the collection cup;. Do not collect the first, clear fraction of the ejaculate but dump this on the floor. Continue semen collection until the boar finishes ejaculation and pulls back his penis. Cull boars with a very low index or those slated for replacement display poor semen quality;. Inspect the animal for signs that could help explain poor semen quality like: 0 Lameness/pain 0 Poor body condition 0 Abnormal testis/epididymis (large asymmetry, inflammation, lesions, atrophic, etc. Schedule the collection of flagged boars on low production days so there is sufficient time to review the ejaculate; 4. If necessary, send a sample of the ejaculate to a 3rd party laboratory for microbiological testing; 6. If two consecutive ejaculates with good semen quality are obtained, place the boar back into the normal collection schedule; 7. Monitor to see if semen quality returns to normal after approximately 6-8 weeks after the cause for quality drop is solved. Although it is hard to collect sterile ejaculates under commercial conditions, it is a priority during collection to reduce the bacterial contamination of raw ejaculates as much as possible. Try 2 consecutive days of schedule training followed by 1 day rest and another 2 days of training. Do not treat boars in the collection pen and avoid slick floors/dummy or priming other stressors. In a lot of cases this could be due to multiple, overlapping reasons, so no single cause can be identified. Especially during summer, overall semen quality can decrease due to seasonal and temperature effects. Note that the intensity of response to such stressors can differ between genetic lines and individuals. They can be trained/collected, however it is advised not to use their semen until boar Boar age is approximately 220 days old;. If damage is lesions, strong asymmetry, persistent with no recovery of semen quality, cull the boar. The most common reasons along with intervention strategies are outlined in Table 1. The goal of the laboratory process is the efficient evaluation of ejaculates to determine whether they meet the established quality standards as described in Table 2. Lab design details often have to be decided on a case by case basis depending on the unique situation encountered at each stud (space, staffing, etc. Allows for faster processing No crossing of working ways from ?dirty? (ejaculate arrival, evaluation) to ?clean? In-line-workflow (extension, filling) areas to avoid cross contamination. Lab furniture movable (wheels)/open space to floor Allows to clean area beneath Avoid storage cabinets in the production lab. Cabinets need to be cleaned as well and this is Work with mobile carts containing daily supplies. All surfaces (ceiling, walls, floor, countertops, furniture) composed of the appropriate materials Facilitates proper cleaning and disinfection and constructed for ease of cleaning and compatibility with disinfection. Facilitates easy access to clean No 90? angles between floor and wall Facilitates cleaning Facilitates easy cleaning and no gathering of dirt Floor coating without seams and drains and bacteria Facilitates cleaning with no wires on the floor or Power sockets above equipment area against the wall or on the horizontal surfaces Separate rooms for storage of filled semen doses Facilitates cleaning and lab supplies. The goal is to discard unsuitable ejaculates, especially contaminated ones prior to entering the analysis and processing flow. The requirements for an accurate measurement of sperm concentration with different devices are listed in Table 2. The multiplication of the cell concentration with the ejaculate volume (measured with a scale; 000. Measurements are typically done on the raw or possibly the pre-extended ejaculate (depending on the laboratory protocol and device). Use of an automatic pipetting system as alternative Depending on the system, a dilution of the ejaculate sample prior to measurement is needed. Accuracy and precision of this step has a large influence on the measurement results Mix sample in cuvette by gently inverting it 5X Filling of the standard counting chamber (use cap or parafilm to cover cuvette instead of (according to manufacture instructions). Photometers usually have a sigmoid light A minimum of 400-600 cells to be counted absorption curve. Measurement is only reliable on (depending on chamber and the linear part of the curve. Only ejaculates with a minimum motility of 70% or more are recommended for further evaluation and processing. Motility evaluation is performed on a microscope with phase contrast and a heated (38?C/100?F) stage. Evaluation of a minimum of 5 different Proper software settings (species, sample dilution rate, fields at 200-400x magnification and type of measurement chamber, etc. Evaluation of a new sample if motility Measurement chambers free of dust, debris, moisture. If measurement fields are selected manually, the chosen Evaluation on 0-100% scale fields of view should be in the middle of the chamber. In general the more cells can be counted, the closer the result is to the actual value. This relationship becomes crucial as ejaculate evaluation results move closer to the minimum thresholds (see framed area in table). The thin monolayer that is formed means that the sperm will be in the same focal plane and moving less than in a thicker layer. When oil immersion is used, some pressure is transferred through the oil to the cover slip when focusing. If the sperm suspension layer is thick, sperm will be pushed away from the field of view. Put 1 droplet of raw semen and 2 droplets of stain (most common Eosin-Nigrosin) on a microscope slide. By using the edge or corner of the slide, transfer a small volume of fixed and stained semen to a clean microscope slide and place it near one end of the slide, leaving space for labeling. Using another new microscope slide (spreader) put the short edge on the slide ?downstream? from the drop. Keep the whole edge in contact with the slide and draw back the slide until it touches the drop of stained semen. Wait for the semen to spread to the full width of the slide and then push the spreader in an angle of 45? along the slide to create the smear. The smear should not be very thin (this is not a blood smear) or too thick (this may make appreciation of the differential stain difficult). If there are too many or too few sperm or not enough or too much contrast, prepare a new slide. Low power fields with zero or just one or two sperm mean a slide on which it will be very difficult to find sperm under oil immersion. At the other extreme, the sperm density should not be so high that sperm overlay each other. When changing to a 1,000x from the lower magnification, only a small adjustment is needed to get the cells in focus. A minimum of 100 cells (preferable 2 x 100 cells though) should be counted and evaluated to estimate the percentage of abnormal cells in the ejaculate. Find a spot in the smear where cells are not overlaying each other as the starting point. Start at the top left of a field, follow an imaginary line to the right and assess every cell on that line. Then go 1 line lower and follow this from the right to the left going zigzag through the field.
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Miller Molecular Medicine Branch symptoms ibs careprost 3ml with mastercard, National Institute of Diabetes and Digestive and Kidney Diseases shakira medicine buy careprost with paypal, National Institutes of Health medications used for depression discount 3 ml careprost visa, Bethesda symptoms 7 weeks pregnancy generic careprost 3ml line, Maryland 20892 Correspondence: jm7f@nih. In contrast, it is a health problem that affects major portions of the population in underdevel oped countries. Here, clinical and laboratory features of the disease are discussed, and then focus is placed on relevant economic, environmental, infectious, and genetic factors that converge among global populations. More than one-half of total-body iron is Istates make iron useful for evolving biological contained within hemoglobin. Growing lists of biomolecules that cation of hemoglobin in erythrocytes, anemia bind or incorporate iron are being catalogued is a characteristic trait of iron de? Hemoglobin is the adulthood in the absence of hemorrhage, dis most abundant iron-containing protein in hu ease, or altered physical activity. Owing to a shorter half-life of circulat In general, iron stores are reduced or lost before ing erythrocytes in iron de? Therefore, dietary is recovered sooner in those patients, but the and erythrocyte-recycled iron must meet the amount of iron in each microcytic erythrocyte demands for erythrocyte production. In the event losses continue, the newly produced erythro of hemorrhage, additional iron must be ab cytes will have decreased hemoglobin, causing sorbed from the diet to meet the steady-state the amount of iron provided by the same num demands of the host. Erythrocytes and their precursors require Unlike thalassemia trait, increased numbers of large amounts of iron for the production of erythrocytes are not produced in the iron-de? Iron is central cient state to compensate for the reduction in to hemoglobin structure and function (Perutz intracellular hemoglobin content. The most immediate source of iron for son, reticulocytosis is usually not present. In the erythroblasts is mono or diferric transferrin, absence of major hemorrhage, iron de? Each day, 20 mg of iron is recycled between circulating transferrin (Fe Tf ) and erythrocytes. This recycling pathway is supported by (A) intestinal iron absorption, (B) erythropha gocytosis, (C) hepatic iron stores, and (D) iron incorporation into hemoglobin. In lic domain illustration from Wikipedia and can be the United States, the prevalence of anemia as a found at commons. This seemingly inexplicable paradox of high prevalence despite effective treatment rep ing to age, sex, race, and whether the blood was sampled from the capillary (? Multiple obstacles involving economics, cultural barriers, and infectious diseases con ble et al. In the absence of automated testing, portable devices or visual matching of verge and make eradication of this disease hemoglobin color have been proven to be 95% more dif? The additional challenges that are encountered by certain human subpopula accurate for identifying the hemoglobin level within 1?2 g/dL of reference values (Ingram tions in select geographies need to be overcome and Lewis 2000; Lewis and Emmanuel 2001). Patients may complain of poor mental perfor mance or cold intolerance (Rosenzweig and Volpe 1999). Recogni tion of these features may trigger appropriate laboratory tests and therapy. Some subjects possess the compulsion to move their lower extremities while at rest. The restless leg syndrome is now recognized as a reversible symptom of reduced brain iron levels that is particularly prevalent during pregnancy (Viva relli et al. The mo lecular basis for this unusual behavior is un bone marrow iron (Baker 2000). Long-lasting cognitive challenges oc Therefore, ratios of soluble transferrin receptor cur despite therapy later in life (Lozoff et al. In Laboratory evaluation reveals characteristic patients with chronic renal disease, ferritin lev changes in blood parameters for iron regulation els of. Research studies suggest that low or ab the iron saturation on transferrin is reduced to sent hepcidin levels may be diagnostic of simple values of,15%. The ferritin protein com nent for erythropoiesis owing to the relative lev plex structure acts as a cage to contain up to els and saturation kinetics of transferrin recep 4500 iron molecules (Fig. A serum ferritin level of 15 mg/Lor In addition to iron parameters, a lackof iron less is diagnostic of iron de? However, from menstruation or hookworm infection thalassemia mutations may confound the inter (see below) has the greatest impact worldwide. Detec for increased production of zinc protoporphy tion of occult blood losses of up to 60 mL/d rin in association with decreased heme pro may be dif? After sis is usually somewhat delayed relative to the chronic physical exertion, signi? A full history should from thesenescentcellscontinuesto supportthe be queried in all new cases of iron de? During preg versed, the hemoglobin and hematocrit levels nancy, it is estimated that 1200 mg of iron are decrease to suf? Iron intake and stores in the mother must satisfy fetal development, and blood loss at delivery. Postpar and 20 mg of iron from senescent erythrocytes tum, iron is lost as lactoferrin in breast milk. Once Those losses are balanced by the absence of iron stores are depleted, dietary and recycled menstruation in the lactating female. Hemorrhage itself is addition to the direct effects of anemia, re by far the most common mechanism for acute ducedfetalbrainmaturation,pediatriccognitive iron loss and anemia. Hemorrhage decreasesthe defects, and maternal depression are associated Advanced Online Article. Malaria also causes an im the reversibility of cognitive defects caused at mune response that suppresses erythropoietin an early age by iron de? If left un host may also increase hepcidin expression for treated during infancy, childhood, and adoles protection from liver-stage malaria (Portugal cence, anemia and iron-associated cognitive et al. Of course, increased hepcidin re defects may conceivably be passed between stricts iron and might delay erythroid recovery. The human growth rate is almost loga cent report of potential harm caused by iron rithmic during this period (Anderson and Hol supplementation among preschool children in ford 2008). In requirements must be met before the accumu that study, iron and folic acid supplements were lation of storage iron. Although serum ferritin stopped owing to an increased risk for hospital levels are elevated in the fetus compared with the ization or death from malaria in Zanzibar, Tan mother, the fetal iron stores correlate well with zania. Increased caution for iron supplementa the iron stores of the mother (Milman et al. However, the fetal ferritin levels remain 10 times higher a recent Cochrane paper recommended, ?iron than the maternal ferritin at the time of delivery supplementation should not be withheld from (Erdem et al. At birth, the fetal red cell children living in malaria-endemic countries? mass is 50 mL/kg (Phillips et al. Around 80% of that iron is used for ex this critical, but complex issue are awaited. In children and young adults, iron fection affects several hundred million humans de? Amaz utors to the overall disease burden in those pop ingly, a recent study reported that there is a ulations (Gore et al. This clinical accesses the duodenum of a new human host featurewas described in 1898 as blackwater fever directly by mouth, or indirectly via the skin. Ow ing to their location in the small bowel, capsule endoscopy is helpful for diagnosis if eggs are not present in the stool (Li et al. Heavily infected pa tients are simply unable to maintain adequate iron stores and become anemic (Smith and Brooker 2010). Even without additional iron supplements, antihelminthic drugs can cause reversal of iron de? It is currently unknown whether hook worm infection causes increased production of hepcidin in the host. Diet and Malabsorption of Iron Local economics generally dictate the level of nutrition worldwide. The diet becomes far more relevant when the iron stores are lost, or anemia has already developed, and the host requires additional iron absorption from the gut for recovery. This occurs in the multiple settings described earlier in this work: blood loss, rapid growth during infancy,malaria,and hookworm. In these settings, the diet and iron supplements becomecriticalformaintaining ironavailability.
However medications vitamins order careprost amex, BaP and coal tar mixes have also been reported to medications made from animals cheap careprost 3 ml visa produce tumours of the liver medications ok for pregnancy buy careprost 3ml cheap, lung medications starting with p discount careprost 3 ml otc, mammary gland, kidney and auditory canal. In a small case-control study, consumption of wine from bottles impregnated with tar increased the risk of stomach cancer, which was statistically signifcant only for men consuming more than 2L of wine per week (Lopez-Abente et al, 2001). Another case-control study reported an increased risk of colorectal adenomas associated with benzo[a]pyrene intake from meat but more strongly with total intake from the diet (Sinha et al, 1998; Sinha et al, 2001; Sinha et al, 2005). In the controls, median BaP intake was 5 ng/day from meat and 73 ng/day from all food sources compared to 17 ng/day from meat and 76 ng/day from all food sources in the cases. Some genetic polymorphisms have been associated with an increased risk of cancer, but the role of these has not been completely elucidated because compensatory or alternative pathways may exist. A margin of exposure of less than 10,000 is considered to indicate a potential concern for human health. Exposure to heterocyclic aromatic amines from the consumption of cooked red meat and its effect on human cancer risk: A review. Investigation of interactions between N-acetyltransferase 2 and heterocyclic amines as potential risk factors for colorectal cancer. Quantifcation of heterocyclic amines from thermally processed meats selected from a small-scale population-based study. Food-derived heterocyclic amine mutagens: variable metabolism and signifcance to humans. Food heating and the formation of heterocyclic aromatic amine and polycyclic aromatic hydrocarbon mutagens/carcinogens. A pharmacogenetic study to investigate the role of dietary carcinogens in the etiology of colorectal cancer. Processed meat and colorectal cancer: A review of epidemiologic and experimental evidence. Opinion of the Scientifc Committee on Food on the risk to human health of polycyclic aromatic hydrocarbons in Food. Heterocyclic amine content of pork products cooked by different methods and to varying degrees of doneness. Dietary Intake of heterocyclic amines, meat-derived mutagenic activity, and risk of colorectal adenoma. Carcinogenic heterocyclic amines in model systems and cooked foods: a review on formation, occurrence and intake. Individual exposure to endogenous nitrosamines is highly dependent on dietary modifers as well as disease status. In a cohort study in Finland (Knekt et al, 1999), 189 gastrointestinal cancers were identifed during the 24 year follow-up period. No signifcant associations were observed with other cancers of the gastrointestinal tract or with nitrate and nitrite intake. Studies have suggested that the conditions found at the gastro-oesophageal junction of the stomach (the cardia region) are optimal for the formation of nitrosamine compounds as the ascorbic acid to nitrite ratio is lowest at this point of the gastroin testinal tract, and the acidity and level of thiocyanate (a known catalyst for nitrosation of secondary amines by acidifed nitrite) are suffcient to potentially promote this reaction (Suzuki et al, 2003). Studies have also identifed a link between consumption of cured and smoked meat and fsh by pregnant mothers and young children with the development of childhood leukaemia and a protective effect of vegetables and bean-curd foods (Liu et al, 2009). Although nitros amine compounds may be more likely to be present in preserved meats (including smoked, cured and salted meats), evidence to link these foods with colorectal cancer is weak. Dietary cured meat and the risk of adult glioma: a meta-analysis of nine observational studies. They have classifed processed meats as meats preserved by smoking, curing or salting, or addition of chemical preservatives. Risk of colorectal and other gastro-intestinal cancers after exposure to nitrate, nitrite and N-nitroso compounds: a follow-up study. Cured meat, vegetables, and bean-curd foods in relation to childhood acute leukemia risk: A population based case-control study. The effect of haem in red and processed meat on the endogenous formation of N-nitroso compounds in the upper intestinal tract. Conditions for acid catalysed luminal nitrosation are maximal at the gastric cardia. The defnition of foods containing iron includes vegetables containing non-haem iron such as spinach. The haem content of preserved and unpreserved meats from the same species appear to be comparable and therefore the haem content alone would not account for the different relative risks associated with non-preserved and preserved red meats. The majority of preserved meat products are of porcine origin and contain lower levels of haem iron than beef-based products. Some of the available studies are outlined below, grouped by proposed mechanism; these are prefaced by some general studies in which the most likely proposed mechanism was not specifed by the authors. There were signifcant increases in proliferation of the colonic epithelium in rats on the haemin diet compared to control animals. Faecal water from the haemin-consuming groups was signifcantly more cytotoxic to erythrocytes compared to controls. Iron supplementation did not have an effect (Cross et al, 2002; Cross et al, 2003). The authors proposed that haem and not iron appears to enhance endogenous N-nitrosation to form mainly nitrosothiols under the acid conditions in the stomach which can then go on to form nitrosyl haem and other nitroso compounds in the alkaline and reductive conditions of the small and large intestines (Kuhnle et al, 2007; Kuhnle and Bingham, 2007). A human study and a rat study showed a signifcant increase in urinary markers of lipid peroxidation (4-hydroxynonenal metabolites or 8-iso-prostaglandin-F(2)? In vitro studies using colon cancer cell lines incubated with haemoglobin and haemin showed that iron from both compounds was released and rapidly absorbed by the cells and resulted in increased proliferation and production of reactive oxygen species (Lee et al, 2006; Glei et al, 2006). In raw cured meat, myoglobin is nitrosylated and further cooking releases nitrosyl haem from the myoglobin. Nitrosylated haem has been shown to be weakly mutagenic in the Ames test, but has not been tested in vivo (Santarelli et al, 2008). A clear mechanism demon strating either an effect of haem or non-haem iron or any differences in risks between preserved or unpreserved red meats has not been demonstrated by the studies above. It is possible that a combination of the above mechanisms is occurring or that different mechanisms may produce N-nitroso compounds which are more potent in their carcinogenic activity than those produced endogenously from sources such as vegetables. These data do not provide a clear basis for separating preserved and unpreserved red meat for modelling purposes. Free radical generating mechanisms in the colon: Their role in the induction and promotion of colorectal cancer? Red meat and colorectal cancer risk: the effect of dietary iron and haem on endogenous N-nitrosation. Haem, not protein or inorganic iron, is responsible for endogenous intestinal N-nitrosation arising from red meat. Meat consumption and risk of colorectal cancer: a metaanalysis of prospective studies. Hemoglobin induces colon cancer cell proliferation by release of reactive oxygen species. Meat, fsh, and colorectal cancer risk: the European Prospective Investigation into cancer and nutrition. Meat consumption and colorectal cancer risk: dose response meta-analysis of epidemiological studies. New marker of colon cancer risk associated with heme intake: 1,4-dihydrox ynonane mercapturic acid. Beef meat and blood sausage promote the formation of axoxymethane-induced mucin-depleted foci and aberrant crypt foci in rat colons. Meat and Cancer: haemoglobin and haemin in a low-calcium diet promote colorectal carcinogenesis at the aberrant crypt stage in rats. Processed meat and colorectal cancer: a review of epidemiologic and experimental evidence. Lipid peroxyl radicals from oxidised oils and heme-iron: implication of a high-fat diet in colon carcinogenesis. Red meat and colon cancer: the cytotoxic and hyperproliferative effects of dietary heme. Food, nutrition, physical activity and the prevention of cancer: a global perspective. Additives can only be used in processed meats (including pre-packed fresh minced meat) and processed meat products. In order for an additive to be approved for use, the applicant must submit suffcient safety data to demonstrate than no adverse effects would be expected under the conditions of use. The data may include acute and chronic studies and reproductive toxicity studies in animals as well as in vitro studies to identify genotoxic activity. If a substance is found to cause cancer in laboratory animals by a genotoxic mechanism, it would not be permitted for use as an additive in foods.