Iron saturated

Since the reactions (15), (16), and (17) require successively higher temperatures, the blast furnace temperature is kept highest near the bottom of the furnace. Near the bottom, the temperature, is sufficiently high that the impure iron—saturated with carbon—collects there as a molten liquid. The slag, which is mainly calcium silicate, CaSi03, removes any sand in the ore through reaction with limestone, CaC03. 

Immunohistochemical studies carried out in our laboratories have demonstrated the presence of xanthine oxidase in synovial endothelial cells (Stevens etal., 1991). As expected, the activity of this enzyme per unit weight of tissue is generally higher in synovia taken from RA patients due to their increased vascularity (Allen et al., 1987). In addition, it has also been shown that rheumatoid synoviocytes contain increased levels of iron-saturated ferritin (Morris et d., 1986). Xanthine oxidase (but not dehydrogenase) is able to mobilize iron from ferritin, supplying the necessary transition metal catalyst for the Haber-Weiss reaction and promoting OH formation (Biemond eta/., 1986). 

Certain organic compounds, especially polyphenols, stimulate mobilization of clay by neutralizing positive charges at the edges of clay minerals. As iron-saturated organic complexes are insoluble, this process might be of little importance in Fe-rich Luvisols (particularly common in the subtropics). 

The peculiar thing in hereditary haemochromatosis (HH) is that the intestinal mucosal cell behaves essentially like an iron deficient cell. Iron absorption is always high if related to the body s iron needs. In HH subjects with normal plasma ferritin values, both mucosal uptake and mucosal transfer of iron often exceed values found in patients with uncomplicated iron deficiency (Marx, 1979b). In fact the situation with respect to iron absorption in mature intestinal mucosal cells, as depicted in Figure 9.4(b), is identical to that in iron deficiency, except for the difference in plasma iron saturation. It was already known that mucosal cells in HH contain no ferritin, explaining the high mucosal transfer of iron (Francanzani... 

The aim of treatment of iron overload is to remove all potentially toxic iron from the body. In hereditary haemochromatosis this can be achieved by weekly phlebotomies of 500 ml until the desired serum ferritin concentration (mostly <50 gg/1) or a normal transferrin iron saturation is reached (Brissot et ah, 2000). 

In 1991, Brieland and Fantone [163] demonstrated that PMA-stimulated neutrophils stimulate ferrous ion mobilization from holosaturated transferrin but not from transferrin at physiological levels of iron saturation (about 32%) at pH 7.4. Decreasing pH drastically... 

The demonsfrafion fhaf fhe bacteriostatic activity of lactoferrin can be independenf of fhe level of iron saturation (Arnold et ah, 1980) suggests that lactoferrin has ofher antimicrobial mechanisms. Lactoferrin has been... 

Investigations of the kinetics of the reaction of these new siderophores with iron-saturated transferrin showed a rapid formation of a ternary complex with transferrin, followed by a slow step in which the ferric siderophore was released from the apoprotein. Weitl et al.257 have evaluated the ferric-chelating properties of several of these siderophores and found the following order of effectiveness for removing iron from transferrin enterobactin > MECAMS > MECAM > LICAMS > DFOA > TRIM-CAMS. 

A neurological examination is normal in patients with the primary form of RLS, but patients with late-onset RLS symptoms and secondary forms may show evidence of a peripheral neuropathy or radiculopathy [38], Apart from the established causes of secondary RLS, there are no known physical abnormalities associated with RLS. A low to normal serum ferritin level (45-50 mg/L) has been related to increased severity of RLS, and may be associated with an increased risk of the occurrence of RLS even in patients with normal hemoglobin levels [37,39], Therefore, evaluations of serum ferritin levels and percentage of iron saturation are highly recommended as part of the medical evaluation for RLS. 

Recent studies further suggest that LF may have a role in the development and progression of tumors (Tsuda et al., 2002). Orally administered bovine LF has been found to inhibit the development of tumors in the colon, oesophagus and lung carcinogenesis in a rat or mouse model, but the mode of action remains to be resolved (Sekine et al., 1997 Ushida et al., 1999 Kuhara et al., 2000). The anti-tumor activity may be mediated by the enhanced cytokine production or the activating effect on natural killer cells and be independent of the iron-saturation level. 

Table I. Correlations between Levels of Iron-saturated Tr and Degrees of Bacillary Growth in Mammalian Sera (20)...

Figure 2. Two-week growth of tubercle bacilli in tuberculostatic bovine serum containing 5 mg Tr and different concentrations of mycobactin in ml of solution. ( ) iron-saturated Tr (M) iron-free Tr (O) no Tr (22).

Low iron levels in human blood were observed by clinicians to be associated with infectious diseases. A decrease in plasma iron levels was induced by bacterial infections (33, 34) or by treatment with bacterial endotoxins (35). The treatment of animals with endotoxin-released mediator of hypoferremia protected them from lethal salmonellosis (36). Although the levels of hypoferremia or degrees of iron saturation of Tr were not examined in these studies, various experiments indicated that the fall in serum iron increased resistance to bacterial infections. 

A saturation effect is indicated in that iron enhances identically the cadmium inhibitory effect upon manganese absorption irrespective of the cadmium dose. In addition, the iron dose does not alter only the already strong effect of high cadmium dose. Furthermore, within a span of 5.0-15.0 mg Fe/100 ml iron has an equal effect upon cadmium action, while below 2.5 mg Fe/100 ml it does not alter the effect of cadmium at all. This is yet another indication of iron saturation at a level above 5.0 mg Fe/ml milk, as observed earlier (83). 

---