To determine the stomach bioreactor capability for food oxidation or antioxidation, rats were fed red turkey meat cutlets (meal A) or red turkey meat cutlets and red wine concentrate (meal B). The hydroperoxides (LOOH) and malondialdehyde (MDA) levels of the stomach contents were evaluated during and after digestion; the postprandial plasma MDA level was also evaluated. In independently fed rats, the stomach LOOH concentration fell substantially 90 min following the meal, and the addition of red wine polyphenols enhanced LOOH reduction 3-fold. A similar trend was obtained for MDA. After pyloric ligation, the stomach contents of rats fed red meat homogenate showed >2-fold increases in LOOH and MDA accumulation. The postprandial plasma MDA level increased significantly by 50% following meal A and was maintained or even fell by 34% below basal level following meal B. The findings show that consumption of partially oxidized food could increase lipid peroxidation in the stomach and the absorption of cytotoxic lipid peroxidation products into the body. The addition of antioxidants such as red wine polyphenols to the meal may alter these outcomes. These findings explain the potentially harmful effects of oxidized fats in foods and the important benefit of consuming dietary polyphenols during the meal.

Current evidence supports a contribution of polyphenols to the prevention of cardiovascular disease, but their mechanisms of action are not understood. We investigated the impact of red wine polyphenols on postprandial cytotoxic lipid peroxidation products (MDA) levels in humans. In a randomized, crossover study, the effect of red wine polyphenols on postprandial levels of plasma and urine MDA was investigated. Three meals of 250 g turkey cutlets supplemented by water (A); soaked in red wine after heating plus 200 ml of red wine (B); or soaked in red wine prior to heating plus 200 ml of red wine (C) were administered to 10 healthy volunteers. Subject baseline plasma levels of MDA were 50 +/- 20 nM. After a meal of turkey meat cutlets, plasma MDA levels increased by 160 nM (P<0.0001); after (B) there was a 75% reduction in the absorption of MDA (P<0.0001). However, after (C), the elevation of plasma MDA was completely prevented (P<0.0001). Similar results were obtained for MDA accumulation in urine. Our study suggests that red wine polyphenols exert a beneficial effect by the novel new function, absorption inhibition of the lipotoxin MDA. These findings explain the potentially harmful effects of oxidized fats found in foods and the important benefit of dietary polyphenols in the meal.-Gorelik, S., Ligumsky, M., Kohen, R., Kanner, J. A novel function of red wine polyphenols in humans: prevention of absorption of cytotoxic lipid peroxidation products.

The Western diet contains large quantities of oxidized lipids, because a large proportion of the food in the diet is consumed in a fried, heated, processed, or stored form. We investigated the reaction that could occur in the acidic pH of the stomach and accelerate the generation of lipid hydroperoxides and cooxidation of dietary vitamins. To estimate the oxygen content in the stomach after food consumption, oxygen released from masticated bread (20 g) into deoxygenated water (100 mL) was measured. Under these conditions, the oxygen concentration rose by 250 microM and reached a full oxygen saturation. The present study demonstrated that heated red meat homogenized in human gastric fluid, at pH 3.0, generated hydroperoxides and malondialdehyde. The cross-reaction between free radicals produced during this reaction cooxidized vitamin E, beta-carotene, and vitamin C. Both lipid peroxidation and cooxidation of vitamin E and beta-carotene were inhibited at pH 3.0 by red wine polyphenols. Ascorbic acid (44 mg) at a concentration that represented the amount that could be ingested during a meal inhibited lipid peroxidation only slightly. Red wine polyphenols failed to prevent ascorbic acid oxidation significantly but, in conjunction with ascorbic acid, did inhibit lipid peroxidation. In the presence of catechin, a well-known polyphenol found in red wine, ascorbic acid at pH 3.0 works in a synergistic manner preventing lipid peroxidation and beta-carotene cooxidation. The present data may explain the major benefits to our health and the crucial role of consuming food products rich in dietary antioxidants such as fruits, vegetables, red wines, or green tea during the meal.

Our recent study demonstrated the potential of gastric fluid at pH 3.0 to accelerate lipid peroxidation and cooxidation of dietary constituents in the stomach medium. Metmyoglobin is known to catalyze the breakdown of lipid hydroperoxides to free radicals, a reaction that could enhance the propagation step and general lipid peroxidation. During this reaction, a part of the free radicals is autoreduced by metmyoglobin. At pH 3.0, metmyoglobin at low concentration was almost 7 x 10(4) times as effective as at pH 7.0 in enhancing the rate of lipid peroxidation. Our study demonstrated that metmyoglobin, at a low concentration (approximately 1:30), as compared with that of the hydroperoxides in the lipid system, worked prooxidatively increasing the amounts of linoleate hydroperoxides. However, at a high concentration (approximately 1:3), metmyoglobin acted antioxidatively and decomposed hydroperoxides, whose concentrations then remained at zero for a long time. Catechin, a known polyphenol, supports the inversion of metmyoglobin catalysis, from prooxidation to antioxidation. The antioxidative activity of the couple metmyoglobin-catechin was better at pH 3.0 than at pH 7.0, indicating that this reaction is more dependent on metmyoglobin than on catechin. During this reaction, catechin or quercetin not only donates reducing equivalents to prevent lipid peroxidation but also prevents the destruction and polymerization of metmyoglobin. The results of this research highlighted the important and possible reactions of heme proteins and polyphenols as couple antioxidants, working as hydroperoxidases or as pseudo-peroxidases. We hypothesize that the occurrence of these reactions in the stomach could have an important impact on our health and might help to better explain the health benefits of including foods rich in polyphenol antioxidants in the meal, especially when consuming red meat.

Grilled red turkey muscle (Doner Kabab) is a real "fast food" containing approximately 200 microM hydroperoxides, homogenized in simulated gastric fluid and oxidized more rapidly at pH 3.0 than at pH 5.0, after 180 min, producing 1200 and 600 microM hydroperoxides, respectively. The effects of "free" iron ions and metmyoglobin, two potential catalyzers of lipid peroxidation in muscle foods, were evaluated for linoleic acid peroxidation at pH 3.0 of simulated gastric fluid. The prooxidant effects of free iron ions on linoleic acid peroxidation in simulated gastric fluid was evaluated in the presence of ascorbic acid. At low concentrations of ascorbic acid, the effects were prooxidative, which was reversed at high concentrations. In the presence of metmyoglobin, ascorbic acid with or without free iron enhanced the antioxidative effect. Lipid peroxidation by an iron-ascorbic acid system was inhibited totally by 250-500 microM catechin at pH 3.0. The catechin antioxidant effect was determined also in the iron-ascorbic acid system containing metmyoglobin. In this system, catechin totally inhibited lipid peroxidation at a concentration 20-fold lower than without metmyoglobin. The ability of catechin to inhibit lipid peroxidation was also determined at a low pH with beta-carotene as a sensitive target molecule for oxidation. The results show that a significant protection was achieved only with almost 100-fold higher antioxidant concentration. Polyphenols from different groups were determined for the antioxidant activity at pH 3.0. The results show a high antioxidant activity of polyphenols with orthodihydroxylated groups at the B ring, unsaturation, and the presence of a 4-oxo group in the heterocyclic ring, as demonstrated by quercetin.

A number of natural phenolic compounds display antioxidant and cell protective effects in cell culture models, yet in some studies show prooxidant and cytotoxic effects. Pancreatic beta-cells have been reported to exhibit particular sensitivity to oxidative stress, a factor that may contribute to the impaired beta-cell function characteristic of diabetes. The aim of this study was to examine the potential of natural phenolics to protect cultured pancreatic beta-cells (betaTC1 and HIT) from H(2)O(2) oxidative stress. Exposure of cells to H(2)O(2) led to significant proliferation inhibition. Contrary to what one should expect, simultaneous exposure to H(2)O(2) and the phenolics, quercetin (10-100 microM), catechin (50-500 microM), or ascorbic acid (100-1000 microM), led to amplification of proliferation inhibition. At higher concentrations, these compounds inhibited proliferation, even in the absence of added H(2)O(2). This prooxidant effect is attributable to the generation of H(2)O(2) through interaction of the added phenolic compounds with as yet undefined componenets of the culture media. On the other hand, inclusion of metmyoglobin (30 microM) in the culture medium significantly reduced the prooxidant impact of the phenolics. Under these conditions, quercetin and catechin significantly protected the cells against oxidative stress when these components were present during the stress period. Furthermore, significant cell protection was observed upon preincubation of cells with chrysin, quercetin, catechin, or caffeic acid (50 microM, each) prior to application of oxidative stress. It is concluded that provided artifactual prooxidant effects are avoided, preincubation of beta-cells with relatively hydrophobic natural phenolics can confer protection against oxidative stress.

It has recently been suggested that the ability of apple extracts to inhibit proliferation of tumor cells in vitro may be due to phenolic/flavonoid antioxidants. Our study demonstrates that this inhibition is caused indirectly by H(2)O(2) generated through interaction of the phenolics with the cell culture media. The results indicate that many previously reported effects of flavonoids and phenolic compounds on cultured cells may result from similar artifactual generation of oxidative stress. We suggest that in order to prevent such artifacts, the use of catalase and/or metmyoglobin in the presence of reducing agents should be considered as a method to decompose H(2)O(2) and prevent generation of other reactive oxygen species, which could affect cell proliferation. The use of tumor cells and "nontumor cells" in a bioassay to measure antioxidant activity, in this context, is potentially misleading and should be applied with caution.

It has been found that although there is some parallelism between the quantity of tubercle bacilli demonstrable histologically and the number of colonies that can be isolated from a given tissue, the culture method is far the more efficient in indicating quantitative relations. Tubercle bacilli were not perceived in the organs of rabbits 1 day after infection with the modified BCG although as many as 1,500 colonies were isolated from one of them. This may be solely because it is difficult to see widely dispersed single minute acid-fast rods in the diffuse infiltrations of mononuclears with their hyperchromatic nuclei and sparse cytoplasm. Later, with the formation of tubercle, the parallelism is much closer. The culture method gives evidence concerning the number of living tubercle bacilli in the tissue. The significance of the accumulation of acid-fast particles in the tissues has been discussed. It has been seen that from the beginning this accumulation is greater in the Kupffer cells of the liver, in the macrophages of the spleen and in the reticular cells of the bone marrow than within the mononuclears of the lung, the organ where the bacilli grow with the greatest rapidity and are destroyed with the greatest difficulty. Acid-fast particles are more prominent with the bovine than with the human bacillus or the BCG, the microorganism that is destroyed with the greatest difficulty thus leaving more incompletely digested bacillary debris at a given time within the cells. Thus it seems permissible to conclude from the presence of acid-fast material that some tubercle bacilli are undergoing destruction even 24 hours after infection. The initial accumulation of polynuclear leucocytes corresponds with the subsequent severity of the infection. Despite the greater primary localization of bacilli in the liver, this initial inflammatory reaction with all three infections is much greater in the lung than in the liver. In each organ it is more intense with the bovine than with the less virulent strains. The multiplication of the bacillus and its accumulation within large mononuclear and young epithelioid cells is accompanied by an intense formation of new mononuclears by mitosis. The more rapid the growth of the bacillus, the more conspicuous the regeneration of these cells. Thus with all strains mitosis is more intense in the more susceptible organ, as in the lung compared with the liver; with the most virulent strain the most extensive and diffuse accumulation of these new cells corresponds with the greater rise in the numbers of bovine bacilli after the lag of the 1st week. With the maturation of the epithelioid cells and the formation of tubercles the bacilli have already been greatly reduced numerically and the speed of this process diminishes with the virulence of the three strains used. The faster the development of tubercle the faster the destruction of the bacillus and the earlier the resorption of the tubercle. Tubercle bacilli never accumulate in such large numbers in the mononuclears of the liver as they do in the lung. Though at first the tubercles in the liver may be more numerous than those in the lung they never attain the same size. The formation of new mononuclears by mitosis is restricted and Langhans' giant cells appear very early (1st and 2nd weeks). In the lung, giant cells are not found until much later with the BCG and the human bacillus (4th week); they were not noted in the interstitial tubercles with the bovine type, but the extension of these tubercles was accompanied by an unabated mitosis of mononuclears until the death of the animal. The liver tubercles are resorbed early even with the bovine infection. Associated with these histological differences are the slow initial growth and the early and complete destruction of the tubercle bacilli even of bovine type in the liver, and the more rapid initial growth in the lung, with the later destruction of the BCG and the human bacillus and the unabated growth of the bovine bacillus. Similar differences were observed between the splenic pulp and corpuscle. In the former the accumulation of acid-fast particles was much greater and the tubercles developed earlier. Mitosis of mononuclears was less frequent and giant cells appeared earlier. Tubercle bacilli, always intracellular, disappeared from the tubercles in the pulp sooner than from those in the corpuscle, and the tubercles themselves first disappeared from the pulp. Consequently with the persistence of bacilli mitosis continued in the tubercles of the corpuscle and these attained a much larger size. Moreover individual resistance is linked with the ability to form mature tubercles early. In two animals simultaneously infected with the same strain and killed at the same time, the destruction or retardation of the bacillus is greater in that rabbit in which maturation of the tubercle and of epithelioid cells has proceeded further (Figs. 15 and 16). These observations indicate that the mononuclears of different organs or even of the same organ, as in the different parts of the spleen, have a different capacity to destroy the tubercle bacillus, and that the transformation of the mononuclear into the mature epithelioid cell follows its destruction of the tubercle bacilli. In the lung the more virulent types of bacillus are destroyed within the epithelioid cells of interstitial tubercles but persist in foci of tuberculous pneumonia. In this organ in rabbits infected with the human strain and to a lesser degree in rabbits infected with the bovine strain, the parasite largely disappears from the epithelioid cells of interstitial tubercles. But with both strains tubercle bacilli in large numbers may accumulate within epithelioid cells lying free in the alveoli. With the human type they are numerous within the cells and free in caseous material in the localized foci of caseous pneumonia. With the bovine infection, this caseous pneumonia is more often widespread and in the areas of caseous pneumonia the greater part of the vast accumulation of bovine bacilli in the lungs is found; as many as 200,000 colonies have been isolated from 10 mg. of tissue (Fig. 11). Flooding of the respiratory passages by the caseation of tuberculous lesions into the bronchi plays an important rôle in dissemination of tubercle bacilli through the lung. The process on the contrary is predominantly interstitial when the bovine bacillus is held in check (Fig. 12). Thus there is apparently some factor acting in the alveoli that favors the growth of the parasite. The accumulation of tubercle bacilli is seen especially in the peripheral epithelioid cells in immediate contact with the alveolar space. In the same lung the bacilli are much fewer in the interstitial tubercles. The accumulation in human tuberculosis of large numbers of tubercle bacilli in the tissues lining cavities is well known. Novy and Soule (20) have shown that within certain limits the growth of the bacillus in vitro is proportional to the oxygen tension of its environment. Corper, Lurie and Uyei (21) have confirmed these observations and have noted further that a difference in the gaseous environment of the bacilli equal to the difference between the conditions existing in the alveolar air and the venous blood is sufficient to cause a considerable increase in the growth of the microorganism in vitro. Loebel, Shorr and Richardson (22) by the use of Warburg's manometer have found that the oxygen consumption of tuberculous tissue is such that a tubercle 0.5 mm. thick would completely exhaust the oxygen of the air before it reached the center. These observations suggest that a factor responsible for the greater multiplication of the bacillus in the cells of the alveoli may be the greater oxygen tension of the alveolar air. In the liver, spleen and bone marrow even with the bovine infection many instances were found of the effective destruction of the parasite synchronously with the maturation of epithelioid cells and the formation of tubercle. On the other hand, in the spleen and bone marrow of some rabbits, living bacilli persisted within the epithelioid cells of isolated tubercles even 2 months after infection, a condition never found with the human type or BCG infection. Thus the epithelioid cell is the means of defense for the rabbit against the bovine type bacillus, and as such it is usually adequate in the liver, spleen and bone marrow though ineffective in the lung and kidney. In the latter, descending infection, and the occasional colony-like multiplication of bacilli in unorganized material, tubular casts, determine the long persistence of large numbers of bacilli in this organ. In differentiating the mononuclear phagocyte of the connective tissues into the monocyte and clasmatocyte Sabin and her coworkers (23) have maintained that the clasmatocyte can efficiently destroy the tubercle bacillus but that the monocyte and its derivatives, the epithelioid and Langhans' giant cells, cannot. With the progress of the disease they have noted that the monocytes accumulate in great numbers in the foci of infection and overflow into general circulation (4). White (24) and Sabin and her coworkers have concluded that tuberculosis is specifically a disease of the monocyte, and that this cell and its derivatives act as incubators for the tubercle bacillus. Doan and Sabin (25) have therefore sought, with indecisive results, to protect the body against tuberculosis by an antimonocytic serum. However it has been shown here that although an intense multiplication of mononuclears is associated with the growth of the tubercle bacillus, their transformation into mature epithelioid cells is constantly associated with its destruction, and the rapidity of the destruction varies with the rapidity of the maturation of tubercle. Even in the bovine infection the epithelioid cells destroy the bacilli in the liver, spleen and bone marrow as a rule, and even in the lung, keep them in check in the interstitial tubercles. The appearance of giant cells is associated with cessation or diminution of mononuclear regeneration by mitosis, and is coincident with cessation of multiplication or marked reduction in the number of living bacilli. They therefore appear earlier and in larger numbers in these organs or parts of organs that first destroy the bacillus (Figs. 16 and 17). They were not observed even 2 months after the bovine infection in the interstitial tubercles in the lung. Their absence and the continued mitosis of mononuclears, which accounts for the massive pneumonic and interstitial consolidation of the lung with this infection, were associated with the failure of the lung to destroy effectively the bovine parasite. The formation of giant cells in the pneumonic foci in the bovine infection would seem to be an exception to this rule. The Langhans giant cells have often been considered an indication of the chronicity of the pathological process. It would appear that they are formed from existing epithelioid cells when the multiplication of the bacillus has ceased and the stimulus for the formation of new cells has decreased or stopped. Giant cells were most conspicuous in the liver and splenic pulp where, with the BCG infection, no caseation ever developed, and in the liver before caseation was seen anywhere in the body. In the human and bovine infections, giant cells formed in the liver before caseation appeared. Hence caseation is not a necessary requirement for giant cell formation, as maintained by Medlar (26), though these cells frequently form about caseous material. Lymphocytes and granulation tissue do not cause the destruction of tubercle bacilli, these being destroyed in their absence. They usually appear about tubercles due to all strains and in all organs, after the greater part of the microorganisms have been destroyed (Fig. 18). The bacilli are not destroyed in the lung with bovine infection where the tubercles are usually little permeated by lymphocytes and granulation tissue. There is however, no constant relation between granulation tissue and destruction of tubercle bacilli, for in the lung after the human infection and even in other organs after the bovine infection isolated tubercles may be surrounded and penetrated by lymphocytes and granulation tissue at a time when considerable numbers of living bacilli are still histologically demonstrable within the epithelioid cells. Caseation is usually not caused by the local accumulation of tubercle bacilli. At first, when the BCG (after 1 week) and the human microorganism (after 2 weeks) are present in the cells in very large numbers as demonstrated both histologically and by culture (Figs. 4 and 13) there is no necrosis of these cells. An exception to this rule found in the lung with the bovine infection is considered below. Later, after the bacilli have been destroyed to a great extent and even though the number of bacilli is small, caseation appears (Fig. 14). After this preliminary destruction the extent of caseation apparently varies with the number of residual bacilli. With the least virulent microorganism, the BCG, few bacilli remained in the liver in the 4th week and no caseation was seen. In the tubercles of the splenic corpuscle at the same time bacilli were somewhat more numerous and there was scant caseation. On the other hand with the human bacillus after 4 weeks more bacilli survived and caseation was more extensive in both organs; with the bovine microorganism tubercle bacilli were much more numerous and caseation was far advanced. In the lung, however, caseation appeared with the first considerable accumulation of the bovine bacilli present 2 weeks after inoculation. That the bovine bacillus is primarily more injurious to the lung of rabbits than the BCG or the human bacillus is suggested by the greater intensity of the initial inflammation and by the more conspicuous accumulation of cells in the alveoli evident from the very beginning of infection. Maximow (27) showed that bovine bacilli even in small numbers cause the death of cells in tissue cultures of rabbit lymph nodes whereas the BCG or the human bacillus may accumulate within the cells in tremendous numbers without injuring them. Nevertheless in the liver, spleen and bone marrow of the living animal, caseation does not appear at the time when bovine bacilli are most abundant, but after they have been greatly reduced in numbers. Large numbers of the less virulent types of tubercle bacilli accumulated in different organs a short time after infection do not cause caseation, and with the bovine infection caseation under the same conditions occurs only in the lung. Later when the animal is sensitized caseation occurs in various organs in the presence of the small numbers of tubercle bacilli that remain in the tissues after most of them have been destroyed, and the extent of this caseation varies with the numbers of residual bacilli. These observations suggest that a large number of bacilli fail to cause necrosis soon after infection whereas a few bacilli produce caseation in the animal that is sensitized. Many investigators have held that caseation is due to sensitization. Krause (28), Huebschman (29) and Pagel (30) think that caseation is caused by the action of tuberculin-like substances on the sensitized tissues of the allergic animal. Rich and McCordock (31) view the process in essentially the same light. Recently Schleussing (32) has suggested that caseation is a coagulation necrosis in Weigert's sense of an allergically inflamed tissue, and is similar to the necrosis of the Arthus phenomenon.

IT WILL BE SEEN FROM THE ABOVE THAT WE HAVE STUDIED THE CONDITIONS ASSOCIATED WITH THE DEPOSIT OF CALCAREOUS SALTS:(I) in connection with normal and pathological ossification, and (2) in pathological calcification as exhibited in (a) atheroma of the vessels;(b) calcification of caseating tubercular lesions;(c) calcification of inflammatory new growth, and (d) degenerating tumors; and we have induced experimentally deposits of calcareous salts in the lower animals:(a) within celloidin capsules containing fats and soaps;(b) in the kidney, and (c) in connection with fat necrosis. I. We have found that bone formation and pathological calcareous infiltration are wholly distinct processes. In the former there is no evidence of associated fatty change, and the cells associated with the process of deposition of calcium are functionally active. In the latter there is an antecedent fatty change in the affected areas, and the cells involved present constant evidences of degeneration. The view that would seem to account best for the changes observed in the latter case is that with lowered vitality the cells are unable to utilize the products brought to them by the blood, or which they continue to absorb, so that the normal series of decompositions associated with their metabolism fails to take place and hence they interact among themselves in the cytoplasm with the result that insoluble compounds replace soluble ones. II. Besides the fact that calcification is always preceded by fatty change within the cells, another fact should be emphasized. namely: that combination of the fats present with calcium salts to form calcium soaps tends to occur. The stages immediately preceding these are difficult to follow with anything approaching certainty, perhaps because the earlier stages vary under different conditions. In fat necrosis, for instance, the cells affected are normally storehouses for neutral fats, and as long as they remain healthy neutral fats alone are present in them. When they are subjected to the action of the pancreatic juice with its fat-splitting ferment the cells are killed and coincidently the neutral fats are decomposed, fatty acids being deposited. The fatty acids now slowly combine with the calcium salts. In degenerating lipomata the process would seem to be similar. But in other cases the cells are not obviously fat-containing in the normal state; nevertheless prior to calcification they undergo so-called fatty degeneration, which is really a form of cell degeneration accompanied by fat infiltration. As regards the source of the cell fats in general we may safely accept: 1. That fats are transported in the blood as diffusible soaps. 2. That taken up by the cells these soaps may either-(a) Be reconverted into neutral fats and become stored in the cytoplasm as such, or (b) undergo assimilation proper, becoming part and parcel of the cell substance, in which case they are not recognizable by the ordinary microchemical tests. 3. If these two possibilities be accepted it follows that the appearance of fats and soaps in the degenerating cell may be due to either-(a) Absorption or infiltration of soaps from the surrounding medium, the degenerating cell retaining the power of splitting off the fat but being unable to utilize this in metabolism.(b) Cytoplasmic disintegration with dissociation of the soap-albumen combination or, more broadly, liberation of the fats from their combination with the cytoplasm. The appearances seen in the cells of atheromatous areas indicate that the first of these does occur. III. In areas undergoing calcareous infiltration we have demonstrated. the presence of soaps, and this often in such quantities that they can be isolated and estimated by gross chemical methods. By microchemical methods also we have been able to show that after removing all the neutral fats and fatty acids by petroleum ether there remains behind a substance giving with Sudan III the reaction we associate with the presence of soap. And experimentally we have produced these soaps within the organism, more particularly by placing capsules containing fats and fatty acids within the tissues and after several days finding that the capsules contain calcium soaps and possess a calcium content far in excess of that of the normal blood and lymph. IV. While these are the facts, certain of the details of this reaction demand elucidation. The existence of sodium and it may be potassium soaps in the degenerated cells is comprehensible if we accept that these are present in the circulating lymph and simply undergoing absorption. But even then, as these are diffusible substances how is it to be explained that they become stored up in these particular areas? We have found that, as a matter of fact, in regions which give the reaction for soaps, but which give no reaction for calcium (which therefore presumably contain at most amounts of the insoluble calcium soap too small to need consideration, the ordinary solvents for potassium and sodium soaps do not forthwith remove the stainable material; they are relatively insoluble. The reason for this insolubility is suggested by the observations made in the test tube, that soap solutions mixed with solutions of white of egg or blood serum form a precipitate of combined soap and albumen, which likewise is insoluble in water and alcohol. The indications are therefore that in cells undergoing degeneration, with degeneration of the cytoplasm, certain albuminous molecules unite with the soaps present to form relatively insoluble soap-albuminate. V. With regard to calcium soaps, these are also present and in certain stages appear to be the dominating form in the affected tissues. Two questions suggest themselves, viz.: what is the source of calcium, and what is the process by which they become formed? As to the source, the amount present in well-marked calcification is far in excess of the normal calcium contents of the affected tissue. If in the kidneys of experimental calcification three hundred times as much calcium may be present as in the normal kidney (von Kossa), the calcium must be conveyed to the part by the blood and lymph, and that this is so is demonstrated, as we have pointed out, by the distribution of the infiltration in solid organs, that like ovarian fibroids have undergone necrosis, in which the earliest deposits are superficial. As to the process, there are three possibilities: 1. That sodium and potassium soaps and soap albuminates are first formed and that interaction occurs between them and the diffused calcium salts from the lymph, the less soluble-calcium replacing the sodium and potassium. 2. That under certain conditions the calcium salts act directly on the neutral fats present in the degenerating cells. 3. That the neutral fats are first broken down into fatty acids and that these react with the calcium salts to form the soaps. We are assured that the first process occurs and that because in the boundary zone of areas of calcification we can detect soapy particles devoid of calcium, identical in position and arrangement with the particles more deeply placed which give the calcium reactions. But this is not the only reaction. In case of fat necrosis we see clearly that the third process is in evidence. And we are far from being convinced that the second does not also obtain. We have been impressed by the large accumulation of neutral fats in the cells in cases of early atheroma and the absence at any stage of the process of recognizable fatty acid. While soaps, it is true, are compounds of fatty acids with alkalies, it is recognized in ordinary domestic life that they can be formed by the direct action of strong lye upon ordinary fats, and this even in the cold. It is quite possible therefore that there occurs a similar direct process in the organism. The point is worth noting, however, that this does not occur in healthy cells the seat of fatty infiltration. We therefore leave this an open question, only laying down that, as indicated by the hyalin albuminous matrix left when calcium salts are dissolved out of an area of calcification, there must exist a calcium soap- or fat-albuminate similar to the potassium and sodium soap-albuminates already mentioned-such an albuminate as we can form with calcium soaps in the test tube. VI. In old areas of calcification soaps are largely if not entirely wanting, although these are to be detected at the periphery, when the process is still advancing. The reactions given by these older areas are almost entirely those of calcium phosphate, though some calcium carbonate is at times to be made out. This seems surely to indicate that the final stage in calcification is an interaction between the calcium soap-albuminates and substances containing phosphoric and carbonic acids. Such substances, it is needless to say, are present in considerable amounts in the lymph and blood. We must conclude that the acid sodium phosphates of the lymph act on the calcium soap, the highly insoluble calcium phosphates being formed (plus the albuminous moiety of the original compound) and diffusible sodium soap being liberated, while similarly alkaline carbonates form calcium carbonate and liberate sodium and potassium soaps. Calcium phosphate and calcium carbonate thus become the insoluble earthy salts of old crystalline areas of calcification. VII. As already stated very little soap is to be found in these old areas. It is possibly worth suggestion that the soaps liberated in this last reaction, as they diffuse out, again react with diffusible calcium salts and form calcium soaps which once more react with the alkaline salts to produce the phosphates and carbonates; that, in short, they have a katalytic action. Certain it is that old calcareous areas are extraordinarily dense, and have a coarse crystalline structure, wholly at variance with the finely granular appearance of the more recent areas, and these large crystalline masses, it would seem, can only be formed by successive deposition of new material and eventual fusion, as the interspaces become filled in between the original masses.

Three experiments were carried out with rats (experiments 1 and 2) and guinea pigs (experiment 3) to study the effect of oxidized fats, in interaction with dietary concentrations of vitamins E and C, on the antioxidant status of erythrocytes and the rate of haemolysis. In experiment 1, diets with fresh or thermoxidized fats, containing either 25 or 250 mg alpha-tocopherol equivalents/kg were used; experiment 2 included diets with fresh or thermoxidized fats, containing 25 mg alpha-tocopherol equivalents/kg; in experiment 3, besides a control diet with a fresh fat, diets containing thermoxidized fats with various concentrations of Vitamin E (35 vs. 175 mg alpha-tocopherol equivalent/kg) and Vitamin C (300 vs. 1000 mg/kg) were used. Rats and guinea pigs fed diets with oxidized fats had reduced concentrations of glutathione in erythrocytes as compared with animals fed the fresh fat diets. In rats fed oxidized fats, the activity of catalase and in guinea pigs fed oxidized fats, the activity of glutathione peroxidase plus the concentration of alpha-tocopherol was reduced in erythrocytes as compared with animals fed the equivalent fresh fat diets. The concentrations of alpha-tocopherol in erythrocytes were increased by both, Vitamin E and Vitamin C while the concentrations of glutathione were independent of the concentrations of those vitamins in the diets. Erythrocytes of guinea pigs fed oxidized fats also showed an increased susceptibility to haemolysis during incubation in hypotonic salt solutions; this effect could be improved by increasing the concentrations of both, Vitamin E and Vitamin C. Parameters of in vivo haemolysis (activities of lactate dehydrogenase and acidic phosphatase and concentrations of potassium and free haemoglobin in plasma) were not adversely affected in rats and guinea pigs fed the oxidized fats as compared with animals fed the fresh fats. The study shows that dietary oxidized fats reduce the antioxidant status of erythrocytes and increase their susceptibility against haemolysis but do not increase the rate of haemolysis in vivo.

BACKGROUND: Chronic diseases as well as complications to acute and chronic disease are repeatedly associated with accumulation in the body of glycated and lipoxidated proteins and peptides. These molecules are strongly associated with activation of a specific receptor called RAGE and a long-lasting exaggerated level of inflammation in the body. METHODS: PubMed reports in excess of 5000 papers plus about 14000 articles about the related HbA 1c , most of them published in the last five years. Most of available abstracts have been read and circa 800 full papers studied in detail. RESULTS: RAGE, a member of the immunoglobulin superfamily of cell surface molecules and receptor for advanced glycation endproducts, functions as a master switch, induces sustained activation of NF-kappaB, suppresses a series of endogenous autoregulatory functions and converts long-lasting pro-inflammatory signals into sustained cellular dysfunction and disease. Its activation is associated with high levels of dysfunctioning proteins in body fluids and tissues, and strongly associated with a series of diseases from allergy and Alzheimer to rheumatoid arthritis and urogenital disorders. Heat-treatment, irradiation and ionisation of foods increase the content in foods of AGE/ALE. CONCLUSIONS: Some processed foods are much like tobacco smoking great contributors to accumulation of glycated and lipoxidated molecules in the tissues. Change of life style: avoidance of foods rich in deranged proteins and peptides and increased consumption of antioxidants, especially polyphenols counteracts such a development.

We are interested in the regulation of intracellular calcium and the various diseases associated with an altered regulation of this second messenger. More recently, we also became interested in pathologies involving the Ca2+-binding S100 proteins and AGEs and their association with the multifunctional Receptor for Advanced Glycation Endproducts (RAGE).Introduction: http://dx.doi.org/10.1002/mnfr.200700017Pro arguments: http://dx.doi.org/10.1002/mnfr.200700008.

Advanced glycation endproducts (AGEs) are an heterogenous class of compounds formed by diverse stimuli, including hyperglycemia, oxidative stress, inflammation, renal failure, and innate aging. Recent evidence suggests that dietary sources of AGE may contribute to pathology. AGEs impart diverse effects in cells; evidence strongly suggests that crosslinking of proteins by AGEs may irrevocably alter basement membrane integrity and function. In addition, the ability of AGEs to bind to cells and activate signal transduction, thereby affecting broad properties in the cellular milieu, indicates that AGEs are not innocent bystanders in the diseases of AGEing. Here, we present evidence that receptor for AGE (RAGE) is a receptor for AGEs.Introduction: http://dx.doi.org/10.1002/mnfr.200700017Contra arguments: http://dx.doi.org/10.1002/mnfr.200600284.

The receptor for advanced glycation endproducts (RAGE) has a well-substantiated role in cell dysfunction and mechanisms of inflammatory disease. The physiological agonists of RAGE are less certain: S100/calgranulin proteins, high mobility group-1 protein HMGB1 and other proteins are candidate agonists. It increasingly appears unlikely proteins modified by advanced glycation endproducts are effective agonists in vivo. In the following debate, Professors Ann Marie Schmidt and Claus Heizmann gave arguments and evidences for and against the motion. Recent evidence suggesting the activation of RAGE impairs the enzymatic defence against glycation provided by glyoxalase 1 (Glo 1) suggests that studies of RAGE will continue to be of importance to our understanding of the physiological significance of protein glycation.Pro arguments: http://dx.doi.org/10.1002/mnfr.200700008Contra arguments: http://dx.doi.org/10.1002/mnfr.200600284.

Advanced lipoxidation end-products (ALEs) are formed by reaction of protein with lipid-derived reactive peroxyl and carbonyl compounds produced during food processing and cooking. There is concern that ALEs may induce damage in the gastrointestinal tract, affecting gut health, or enter the body and promote vascular inflammation and tissue damage. However, there is no direct evidence that ALE-proteins are a source of damage in the intestines or that they are transported into the circulation and cause pathology. Modification of proteins by ALEs impedes their digestion, and reactive ALEs released by gastrointestinal proteases would react with proteins or peptides in the gut, limiting their absorption. There are also potent enzymatic mechanisms for detoxifying ALEs or their precursors prior to their entry into the circulation. If ALEs gain access to the circulation, a battery of protective enzymes in tissue provides a second level of defense. These enzymes may be induced in intestinal epithelia and liver by low doses of ALEs, and adaptive responses would provide enhanced protection against future exposure to ALEs. Overall, except in persons with compromised organ function, e. g., vascular, hepatic, or renal diseases, there is little evidence that food ALEs will have any significant pathological effects.Introduction: http://dx.doi.org/10.1002/mnfr.2007000030Pro arguments: http://dx.doi.org/10.1002/mnfr.200600303.

Lipid oxidation in foods is one of the major degradative processes responsible for losses in food quality. The oxidation of unsaturated fatty acids results in significant generation of dietary advanced lipid oxidation endproducts (ALEs) which are in part cytotoxic and genotoxic compounds. The gastrointestinal tract is constantly exposed to dietary oxidized food compounds, after digestion a part of them are absorbed into the lymph or directly into the blood stream. After ingestion of oxidized fats animals and human have been shown to excrete in urine increase amounts of malondialdehyde but also lipophilic carbonyl compounds. Oxidized cholesterol in the diet was found to be a source of oxidized lipoproteins in human serum. Some of the dietary ALEs, which are absorbed from the gut to the circulatory system, seems to act as injurious chemicals that activate an inflammatory response which affects not only circulatory system but also organs such as liver, kidney, lung, and the gut itself. We believe that repeated consumption of oxidized fat in the diet poses a chronic threat to human health. High concentration of dietary antioxidants could prevent lipid oxidation and ALEs generation not only in foods but also in stomach condition and thereby potentially decrease absorption of ALEs from the gut. This could explains the health benefit of diets containing large amounts of dietary antioxidants such those present in fruits and vegetables, or products such as red-wine or tea consuming during the meal.Introduction: http://dx.doi.org/10.1002/mnfr.2007000030Contra arguments: http://dx.doi.org/10.1002/mnfr.200600287.

No Abstract.Pro arguments: http://dx.doi.org/10.1002/mnfr.200600303Contra arguments: http://dx.doi.org/10.1002/mnfr.200600287.