Distribution of transferrin, ferritin, and lactoferrin in human tissues.

An immunoperoxidase staining technique was used for detecting three major iron-binding proteins (transferrin, ferritin, and lactoferrin) in routine histological paraffin sections of human tissue. Transferrin was found mainly in hepatocytes, a variety of epithelial and myoepithelial cells, renal tubular cells, and histiocytes. Ferritin was most readily found in histiocytes and liver cells, with weaker reactions seen in epithelial cells. Lactoferrin was found in lactating breast tissue, bronchial glands, polymorphs, and gastric and duodenal epithelial cells. The technique is potentially valuable for investigating abnormal iron states.     

Immunohistochemical distribution of ferritin, lactoferrin, and transferrin in granulomas of bovine paratuberculosis.

Granulomatous lesions of bovine paratuberculosis contained ferritin, lactoferrin, and a small amount of transferrin, as demonstrated by the immunohistochemical method. Macrophages in the normal bovine ileum did not contain lactoferrin and transferrin; however, ferritin was found in individual macrophages of Peyer's patches. These results may help elucidate the relationship between intracellular growth of Mycobacterium paratuberculosis and the presence of iron-binding proteins in the granulomas.     

Immunohistochemical identification of ferritin, lactoferrin and transferrin in leprosy lesions of human skin biopsies.

Granulomatous lesions of human leprosy contained ferritin and lactoferrin but little or no transferrin, as demonstrated by the avidin-biotin complex immunoperoxidase method. Lactoferrin was found in the neutrophils. These results suggested that the cells of the host mononuclear phagocyte system in leprosy granulomas provide an adequate nutritional environment for iron acquisition by M. leprae. A possible role of iron binding proteins in the granulomas is discussed in relation to previous data on bovine paratuberculous granulomas.     

The distribution of ferritin, lactoferrin and transferrin in granulomatous lymphadenitis of bovine paratuberculosis

Immunohistochemical examination of iron-binding proteins was carried out in the formalin-fixed mesenteric lymph nodes of normal cattle and of cattle with paratuberculosis. Ferritin (FT) and lactoferrin (LF) were found in the granulomas in ileal lymph nodes from six infected cattle. A weak reaction for transferrin (TF) was found in granulomas of a lymph node from one of the infected cattle. FT was found in the macrophages in the medullary sinuses of normal and infected nodes; however, the reaction in infected nodes was generally stronger than that in normal ones. LF in the macrophages was found in only two infected nodes. Neutrophils in both normal and infected cattle always reacted strongly for LF. The TF was always found in the blood vessels and intracellular space. These results suggest that: (1) FT and LF may be important in vivo sources of iron for Mycobacterium paratuberculosis, since their own iron-binding compounds are considered to acquire iron from FT and LF in vitro; (2) the increase in FT and LF in the granulomas may be related to inflammatory hyposideraemia associated with paratuberculosis and (3) epithelioid and giant cells may have a different iron metabolism, from normal macrophages.     

Immunohistochemical localization of transferrin in human breast cancer tissue

The present study was planned to detect the iron binding protein, transferrin (TR) in paraffin sections of the human breast tumors. The distribution of transferrin has been studied in 153 cases (63 benign lesions and 90 malignant tumors). The extent of staining reaction was determined by semiquantitative grading (weak, moderate and consistent). Positivity rate for transferrin was higher (92.2%) in malignant tumors as compared to benign breast lesions (28.5%) with significant p value (p = 0.0001) for both the groups. The intensity was variable in both the groups, being more intense in the malignant tumors. Tumors with higher grade of malignancy presented consistent positive staining along with the lymph nodes involved. The extent of immunoreactivity revealed a significant positive correlation with axillary lymph node status. However, no significant correlation was found with the age of the patients. Thus the study of transferrin in breast tumors besides being of prognostic significance helps in the further management of malignant lesions of the breast.     

Immunohistochemical localization of transferrin in human breast cancer tissue

The present study was planned to detect the iron binding protein, transferrin (TR) in paraffin sections of the human breast tumors. The distribution of transferrin has been studied in 153 cases (63 benign lesions and 90 malignant tumors). The extent of staining reaction was determined by semiquantitative grading (weak, moderate and consistent). Positivity rate for transferrin was higher (92.2%) in malignant tumors as compared to benign breast lesions (28.5%) with significant p value (P = .0001) for both the groups. The intensity was variable in both the groups, being more intense in the malignant tumors. Tumors with higher grade of malignancy presented consistent positive staining along with the lymph nodes involved. The extent of immunoreactivity revealed a significant positive correlation with axillary lymph node status. However, no significant correlation was found with the age of the patients. Thus the study of transferrin in breast tumors besides being of prognostic significance helps in the further management of malignant lesions of the breast.     

Iron uptake from lactoferrin and transferrin by Neisseria gonorrhoeae.

The major iron (Fe) sources available to Neisseria gonorrhoeae in the human host are probably transferrin (TF) and lactoferrin (LF). Although a number of studies have examined Fe uptake by Neisseria meningitidis, no comparable studies have been done on Fe uptake by the gonococcus from TF and LF. We found that, like meningococci, gonococci removed Fe from TF and LF in an energy-dependent manner; uptake was repressed by Fe and did not proceed by a siderophore-mediated uptake system. Unlike published studies examining meningococcal Fe uptake from TF, our study showed that gonococcal Fe uptake from both TF and LF was highly efficient; uptake saturated at 1 microM protein, and growth with 5% saturated TF and LF occurred at maximal rates when the protein was present in appreciable concentrations. We conclude that the availability of protein-bound Fe probably does not limit growth of N. gonorrhoeae in the human body.     

CSF iron, ferritin and transferrin levels in restless legs syndrome

The aim of this study is evaluating iron, ferritin, and transferrin in both serum and CSF in patients of restless legs syndrome (RLS), based on the hypothesis that iron deficiency in the central nervous system (CNS) causes the symptoms as a result of the dysfunction of dopaminergic systems. These parameters, polysomnographic sleep measures, and subjective evaluation of the sleep quality were compared in 10 patients of idiopathic RLS (RLS group) and 10 age-matched patients of psychophysiological insomnia without RLS symptoms (non-RLS group). With sleep patterns, sleep latency was longer and sleep efficiency was lower in the RLS group than those in the non-RLS group. Periodic leg movement index in the RLS group was higher than that of the non-RLS group. With serum examination, there were no significant differences for the iron, ferritin, and transferrin values between the both groups. With CSF examination, the iron and ferritin values were lower and the transferrin values were higher in the RLS group than those in the non-RLS group. There was positive correlation between the serum and CSF ferritin levels in the both groups, but the slope of the regression lines for the RLS group was lower than that for the non-RLS group. These results indicate low brain iron concentration caused by the dysfunction of iron transportation from serum to CNS in patients with idiopathic RLS.     

Acquisition of iron from transferrin and lactoferrin by the protozoan Leishmania chagasi.

Leishmania chagasi, the cause of South American visceral leishmaniasis, requires iron for its growth. However, the extent to which different iron sources can be utilized by the parasite is not known. To address this question, we studied acquisition of iron from lactoferrin and transferrin by the extracellular promastigote form of L. chagasi during growth in vitro. A promastigote growth medium based on minimal essential medium supplemented with iron-depleted serum supported promastigote growth only after the addition of exogenous iron. The addition of 8 microM iron chelated to lactoferrin or hemin resulted in normal promastigote growth. Ferritransferrin also supported promastigote growth, but only after a considerable lag. Promastigotes grown in all three iron sources generated similar amounts of hydroxyl radical upon exposure to hydrogen peroxide, indicating that none of these protected parasites against generation of this toxic radical. Promastigotes were able to take up 59Fe chelated to either transferrin or lactoferrin, although uptake from 59Fe-lactoferrin occurred more rapidly. 59Fe uptake from either 59Fe-transferrin or 59Fe-lactoferrin was inhibited by a 10-fold excess of unlabeled ferrilactoferrin, ferritransferrin, apolactoferrin, apotransferrin, or iron nitrilotriacetate but not ferritin or bovine serum albumin. There was no evidence for a role for parasite-derived siderophores or proteolytic cleavage of ferritransferrin or ferrilactoferrin in the acquisition of iron by promastigotes. Thus, L. chagasi promastigotes can acquire iron from hemin, ferrilactoferrin, or ferritransferrin. This capacity to utilize several iron sources may contribute to the organism's ability to survive in the diverse environments it encounters in the insect and mammalian hosts.     

Damage of the outer membrane of enteric gram-negative bacteria by lactoferrin and transferrin.

Many studies have shown that lactoferrin and transferrin have antimicrobial activity against gram-negative bacteria, but a mechanism of action has not been defined. We hypothesized that the iron-binding proteins could affect the gram-negative outer membrane in a manner similar to that of the chelator EDTA. The ability of lactoferrin and transferrin to release radiolabeled lipopolysaccharide (LPS) from a UDP-galactose epimerase-deficient Escherichia coli mutant and from wild-type Salmonella typhimurium strains was tested. Initial studies in barbital-acetate buffer showed that EDTA and lactoferrin cause significant release of LPS from all three strains. Further studies found that LPS release was blocked by iron saturation of lactoferrin, occurred between pH 6 and 7.5, was comparable for bacterial concentrations from 10(4) to 10(7) CFU/ml, and increased with increasing lactoferrin concentrations. Studies using Hanks balanced salt solution lacking calcium and magnesium showed that transferrin also could cause LPS release. Additionally, both lactoferrin and transferrin increased the antibacterial effect of a subinhibitory concentration of rifampin, a drug excluded by the bacterial outer membrane. This work demonstrates that these iron-binding proteins damage the gram-negative outer membrane and alter bacterial outer membrane permeability.     

Diurnal variation of serum iron,iron-binding capacity,transferrin saturation,and ferritin levels

Serum iron levels vary throughout the day. Morning levels are generally assumed to be higher than afternoon or evening levels. We studied whether our practice of restricting serum iron collections to the morning was necessary. Serum iron, iron-binding capacity, transferrin saturation, and ferritin levels were determined on blood specimens obtained from 20 healthy adult volunteers at 8 AM, noon, and 4 PM (day 1) and 8 AM (day 2). Although statistically significant differences among mean values for the collection times were observed for iron, iron-binding capacity, and (log) ferritin, no consistent diurnal variation was seen. Morning iron levels were higher than afternoon levels for only half of the subjects. Between-day variation for all 4 analytes was similar to within-day variation. We conclude that the practice of restricting iron specimen collections to a specific time of day does not improve the reliability of the test result.     

Monoclonal IgM interference with immunoturbidimetric determination of ferritin and transferrin

When they are present in important blood concentration, the monoclonal immunoglobulins are known to interfere with many immuno-analyze assays. We report the case of a patient presenting a Waldenstrom macroglobulinemia, for which the determination of some parameters of the martial assessment was impossible because of the presence of IgM kappa. The analysis of analytical alarms of the automat as well as the installation of simple and fast pre-treatment protocol of the interference enabled us to quickly make a result useful for the management of this patient.     

Impact of proteases on iron uptake of Pseudomonas aeruginosa pyoverdin from transferrin and lactoferrin.

The Pseudomonas aeruginosa siderophore pyoverdin was unable to acquire iron from human transferrin or lactoferrin at physiological pH. However, in the presence of P. aeruginosa elastase, rapid iron release and pyoverdin iron uptake from transferrin but not from lactoferrin were detected. Neither P. aeruginosa alkaline protease nor elastase from polymorphonuclear leukocytes revealed this effect.     

Distribution of dense core granules in normal, benign and malignant breast tissue

In this study breast tissue from 114 patients has been examined ultrastructurally for dense core granules (DCG). The tissue included examples of normal 'resting', pregnant and lactating breast plus various benign and malignant lesions. DCG were observed in low numbers in the apical cytoplasm in a proportion of the examples of 'resting' and pregnant breast tissue but were absent in the lactating patients. The incidence appeared to relate to hormonal changes. They were present in 50 per cent of the benign lesions examined. DCG were also observed in a high proportion of the ductal, lobular and tubular carcinomas examined and were associated with luminal differentiation. In the mucoid carcinomas over half the tumours possessed some DCG with large numbers of DCG present within certain of the malignant cells in two cases. It is possible that the granules could be related to mucin secretion. Therefore, in normal, benign and malignant (with the exception of mucoid carcinoma) breast tissue the presence of DCG would appear to be related to hormonal changes and represent prelactational differentiation rather than providing evidence of neuroendocrine differentiation. We emphasize the need for a comprehensive knowledge of the normal morphological variations within a tissue before attempting to interpret its tumours.     

Neoangiogenesis and density of microvessels in breast carcinoma tissue

The morphology of neoangiogenesis in breast carcinoma tissue is considered as a relationship between the density of the tumor vascular bed and different indices (age, histological type of a tumor, stage of the disease, tumor anaplastic proliferative activity, fibrosis degree, stromal cellularity, and parenchymal destructive changes).     

Serum ferritin levels and transferrin saturation in men with prostate cancer

Elevated body iron stores (serum ferritin >300 microg/L, transferrin saturation TS >50%) are associated with increased risk of liver and lung cancers. To determine whether such association also exists for prostate cancer (PC), we measured serum ferritin, serum iron, total iron-binding capacity (TIBC), and TS in serum samples from 34 men with newly diagnosed, untreated PC and 84 healthy men, ranging in age from 49-78 years. In contrast with other malignancies, men with PC had significantly lower mean concentrations of serum ferritin (156 microg/L) and TS (24.35%) than those without PC (ferritin, 245 microg/L; TS, 31.98%) (p<0.05). The 95% confidence intervals for ferritin were 109-203 microg/L and 205-286 microg/L, and those for TS were 20.29-28.4% and 28.35-35.61% for men with and without PC, respectively. Significant differences were observed between both groups in the distribution of serum ferritin (<100, 101-300, >300 microg/L) and TS (<16, 16-50, >50%) (p<0.05). A lower percentage of cases than of controls had serum ferritin (17.6% versus 29.8%) and TS (5.9% versus 14.7%) above normal. These differences persisted when the analysis was limited to African-American men (31 cases and 52 controls). Data suggest that elevated body iron stores are less common in men with PC compared to those without PC.     

Validation of tissue microarray technology in breast carcinoma

The recent development of tissue microarray technology has potentiated large-scale retrospective cohort studies using archival formalin-fixed, paraffin-embedded tissues. A major obstacle to broad acceptance of microarrays is that they reduce the amount of tissue analyzed from a whole tissue section to a disk, 0.6 mm in diameter, that may not be representative of the protein expression patterns of the entire tumor. In this study, we examine the number to disks required to adequately represent the expression of three common antigens in invasive breast carcinoma--estrogen receptor, progesterone receptor, and the Her2/neu oncogene--in 38 cases of invasive breast carcinoma. We compared the staining of 2 to 10 microarray disks and the whole tissue sections from which they were derived and determined that analysis of two disks is comparable to analysis of a whole tissue section in more than 95% of cases. To evaluate the potential for using archival tissue in such arrays, we created a breast cancer microarray of 8 to 11 cases from each decade beginning in 1932 to the present day and evaluated the antigenicity of these markers and others. This array demonstrates that many proteins retain their antigenicity for more than 60 years, thus validating their study on archival tissues. We conclude that the tissue microarray technique, with 2-fold redundancy, is a valuable and accurate method for analysis of protein expression in large archival cohorts.     

Radiation and other pathological changes in breast tissue after conservation treatment for carcinoma.

Histological changes in breast tissue after radiotherapy were evaluated. Changes in tissue from 17 patients previously treated for breast cancer by surgery and radiotherapy were compared with those seen in a control group treated with surgery alone. Vascular and epithelial changes were seen only in tissue from patients who had received radiotherapy and, therefore, seemed to be relatively specific; stromal changes were seen in both groups and seemed, therefore, to be non-specific. Epithelial atypia is of particular importance as it may be severe and be confused with recurrent malignancy. The presence of other changes associated with radiotherapy, particularly those in vessels, should help to avoid such misdiagnosis.     

Distribution of breakpoints on chromosome 18 in breast, colorectal, and pancreatic carcinoma cell lines

Chromosome 18 is frequently rearranged in carcinomas. We explored the distribution of breakpoints affecting chromosome 18 by mapping 56 breakpoints in 26 carcinoma cell lines by fluorescence in situ hybridization (FISH) using bacterial artificial chromosomes (BACs) and band paints. The distribution of breaks among 18 intervals of chromosome 18 was significantly nonrandom. The interval spanning the centromere contained the greatest number of breaks and had the highest average copy number of any interval. There was a high density of breaks close to the centromere as well as actually within the centromere. A cluster of breaks encompassing SMAD4 was associated with the minimum average copy number, consistent with SMAD4 being a tumor suppressor gene. There may be another cluster of breaks around 18q12. We offer two interpretations of the concentration of breaks near the centromere. It may reflect selection for an oncogene near the centromere, or there may be an underlying bias of breakage toward the centromere. We show that the latter is predicted by a simple model that invokes random breakage following anchorage of some random point on the chromosome, or selection of breaks proximal to one of several tumor suppressor genes.